text:
Bleomycin lung toxicity detected by technetium-99m diethylene triamine penta-acetic acid aerosol scintigraphy
ųmer Ugur; Biray Caner; M. Derya Balbay; Haluk A. ųzen; Dogan Remzi; Nergis Ulutuncel; Coskun Bekdik
In this study we investigated bleomycin-induced pulmonary toxicity in patients with germ-cell tumour by means of technetium-99m diethylene triamine penta-acetic acid aerosol scintigraphy. Twenty untreated patients who had no clinical or radiological evidence of pulmonary disease received four courses of etoposide, cisplatin and bleomycin chemotherapy. Aerosol lung scintigraphy and pulmonary function tests were performed in all patients before bleomycin treatment
Evaluation of technetium-99m DTPA for localization of site of acute upper gastrointestinal bleeding
H. M. Abdel-Dayem; K. K. Mahajan; S. Ericsson; K. Nawaz; A. Owunwanne; K. Kouris; E. Higazy; M. Awdeh
Intravenous Tc-99m DTPA was evaluated in 34 patients with active upper gastrointestinal bleeding. Active bleeding was detected in 25 patients: nine in the stomach, 12 in the duodenum, and four from esophageal varices. No active bleeding was seen in nine patients (two gastric ulcers and seven duodenal ulcers). Results were correlated with endoscopic and\\/or surgical findings. All completely correlated except:
Technetium 99mTc-DTPA clearance in the evaluation of pulmonary involvement in patients with diabetes mellitus
K. MOUSA; B. O. ONADEKO; H. T. MUSTAFA; M. MOHAMED; A. NABILLA; A. OMAR; A. Al-BUNNI; A. ELGAZZAR
Systemic thickening of capillary endothelial basement membrane underlies the chronic complications of human diabetic microangiopathy. Since99mTc-DTPA aerosol scintigraphy is a sensitive, non-invasive test of membrane permeability, we decided to study the effect of diabetes on the permeability of lung epithelium in diabetic patients using this test.Fifty (NIDDM) patients, aged 40¢70 years, with or without complications, and who were non-smokers, were
Chromium-51-EDTA and technetium-99m-DTPA excretion for assessment of small bowel Crohn's disease
O'Morain, C.; Chervu, L.; Milstein, D.M.; Das, K.M.
In the present study, 4 patients with radiologically documented Crohn's disease were given 100 ..mu..Ci of Cr-51-EDTA and 5 mCi of Tc-99m-DTPA together orally in 10ml of water, and urine was collected during the following 24 hr period. Sequential imaging of the stomach and the GI tract was done with a LFOV gamma camera at 10 min intervals until the activity cleared the small bowel. The images failed to show any localization of the activity in any disease process and no extraintestinal accumulation site was observed scintigraphically. Mean 24 hr urinary excretion for Tc-99m-DTPA was 4.8 +- 2.6% comparable to that of Cr-51-EDTA in these patients. This study suggests that a comparable oral dose of Tc-99m-DTPA could be substituted for Cr-51-EDTA as a far more readily available agent for documenting small bowel Crohn's disease by quantitative assessment of its urinary excretion.
The Effect of Vincristine on the Biodistribution of Technetium99m DTPA, GHA, and DMSA in Balb\\/c Female Mice
Deise Mara; M. Mattos; Maria Luisa Gomes; Rosimeire S. Freitas; Edson M. Boasquevisque; Valbert N. Cardoso; Emilio F. Paula; Mario Bernardo-Filho
Objective: Vincristine has been widely used in various chemotherapeutic protocols in oncology. The purpose of this study was to evaluate the effect of vincristine on the biodistri- bution of 99mTc-DMSA, 99mTc-GHA, and 99mTc-DTPA in Balb\\/c female mice. Methods: Vincristine (0.03 mg, 0.3 mL) was injected into female isogenic Balb\\/c mice (n 5 15), in 3 doses over an interval of
Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m
Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.
Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m
Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.
Technetium-99m-labeled monoclonal antibody with preserved immunoreactivity and high in vivo stability
Arano, Y.; Yokoyama, A.; Furukawa, T.; Horiuchi, K.; Yahata, T.; Saji, H.; Sakahara, H.; Nakashima, T.; Koizumi, M.; Endo, K.
Recent availability of monoclonal antibodies (MoAb) and their radiolabeling through the use of the bifunctional chelating agents (BCA) have become an alternative procedure for in vivo radioimmunodetection. Using a newly synthesized BCA, a p-carboxyethylphenylglyoxal-di(N-methylthiosemicarbazone) (CE-DTS), the coupling and technetium-99m (/sup 99m/Tc) labeling of monoclonal IgG against hCG were carried out. In the system presented, factors affecting stability and immunoreactivity were examined. Immunoreactivity of the original IgG (56C) was preserved by conjugating one CE-DTS molecule per molecule of IgG (56C) using the phosphorylazide method, however, /sup 99m/Tc labeling pH affected the immunoreactivity and limited the /sup 99m/Tc labeling reaction between pH 4.5 and 6.2. A screening of labeling conditions, such as pH, reaction time, and reducing agent system were then carried out. Technetium-99m-labeled IgG (56C), (/sup 99m/Tc)CE-DTS-IgG (56C), showed good stability upon incubation with mice sera and comparable mice biodistribution to that of indium-111 (/sup 111/In) DTPA-IgG (56C). Thus, these results indicate the excellent potential of CE-DTS as a BCA for labeling MoAb with /sup 99m/Tc.
Electron Accelerator's Production of Technetium-99m for Nuclear Medicine
NASA Astrophysics Data System (ADS)
Uvarov, V. L.; Dikiy, N. P.; Dovbnya, A. N.; Medvedyeva, Ye. P.; Pugachov, G. D.; Tur, Yu. D.; Abramova, L. P.; Staren'ky, V. P.
Technetium-99m provides up to 90nuclear medicine at present. His generator Mo-99 is mainly produced in nuclear reactors. Most of reactors used for this production are approaching the end of their exploitation. One suggests to use photonuclear reactions in Mo-100 under influence of bremsstrahlung of powerful electron accelerator as an alternative method of Tc-99m production. Report contents both an analysis of some technical, economical and ecological aspects of Method and the results of experimental production of Tc-99m with KIPT electron linac as well as results of medical tests of produced radiopharmaceuticals.
Technetium-99m NGA functional hepatic imaging: preliminary clinical experience
Stadalnik, R.C.; Vera, D.R.; Woodle, E.S.; Trudeau, W.L.; Porter, B.A.; Ward, R.E.; Krohn, K.A.; O'Grady, L.F.
Technetium-99m galactosyl-neoglycoalbumin ( (Tc)NGA) is a radiolabeled ligand to hepatic binding protein, a receptor which resides at the plasma membrane of hepatocytes. This receptor-binding radiopharmaceutical and its kinetic model provide a noninvasive method for the assessment of liver function. Eighteen patients were studied: seven with hepatoma, eight with liver metastases, four with cirrhosis, and one patient with acute fulminant non-A, non-B hepatitis. Technetium-99m NGA liver imaging provided anatomic information of diagnostic quality comparable to that obtained with other routine imaging modalities, including computed tomography, angiography, ultrasound, and (Tc)sulfur colloid scintigraphy. Kinetic modeling of dynamic (Tc)NGA data produced estimates of standardized hepatic blood flow, Q (hepatic blood flow divided by total blood volume), and hepatic binding protein concentration, (HBP). Significant rank correlation was obtained between (HBP) estimates and CTC scores. This correlation supports the hypothesis that (HBP) is a measure of functional hepatocyte mass. The combination of decreased Q and markedly reduced (HBP) may have prognostic significance; all three patients with this combination died of hepatic failure within 6 wk of imaging.
Technetium-99m antimony colloid for bone-marrow imaging
Martindale, A.A.; Papadimitriou, J.M.; Turner, J.H.
Technetium-99m antimony colloid was prepared in our laboratory for bone-marrow imaging. Optimal production of colloid particles of size range 1 to 13 nm was achieved by the use of polyvinylpyrrolidone of mol. wt. 44,000. Electron microscopy was used to size the particles. Studies in rabbits showed exclusive concentration in the subendothelial dendritic phagocytes of the bone marrow. Pseudopods from these cells were found to traverse interendothelial junctions and concentrate colloid from the sinusoids. Imaging studies of bone marrow in rabbits showed the superiority of the Tc-99m antimony colloid over the much larger colloidal particle of Tc-99m sulfur colloid. Tissue distribution studies in the rat confirmed that bone-marrow uptake of Tc-99m antimony colloid was greater than that of Tc-99m sulfur colloid, although blood clearance was much slower.
Myocardial infarct imaging in patients with technetium-99m 2,3-dimercaptosuccinic acid. Superiority of technetium-99m pyrophosphate
Lyons, K.P.; Milne, N.; Karlsberg, R.P.; Olson, H.G.; Kuperus, J.
Technetium-99m 2,3-dimercaptosuccinic acid (Tc-99m DMSA) has been used successfully for imaging acute myocardial infarction in a canine model. The application in humans, however, has not been previously reported. In order to determine the feasibility of using this agent in clinical studies and to compare the agent to technetium-99m pyrophosphate (Tc-99m PPi), ten patients with proven myocardial infarction were studied. While imaging of transmural infarctions in humans was achieved using Tc-99m DMSA, scores for the Tc-99m DMSA images (1.8 +/- 0.96) were not as high as for Tc-99m PPi (2.5 +/- 0.45) (P less than 0.05). Discordance among four independent interpreters was greater for images obtained with Tc-99m DMSA. The superiority of Tc-99m PPi was evident whether images were obtained early (within 24 hours) or late (within five days). Although DMSA images were not obscured by rib uptake, they were less sensitive (63%) than Tc-99m PPi (97%). A potential advantage of Tc-99m DMSA in imaging acute myocardial infarction is that radiotracer concentration in the infarct occurs primarily in the early postinfarction period. The longer postinfarction that Tc-99m DMSA imaging was attempted, the lower the concentration of radiotracer. Thus, Tc-99m DMSA would not be expected to have the same persistence pattern as Tc-99m PPi into the remote postinfarction period. The persistent positivity of Tc-99m PPi has made it difficult to diagnose reinfarction.
Technetium-99m production issues in the United Kingdom
Green, Christopher H.
Nuclear Medicine developed when it was realised that a radioisotopic substitution of Iodine-131 for the stable Iodine-127 would follow the same metabolic pathway in the body enabling the thyroid to be imaged and the thyroid uptake measured. The Iodine could be complexed with pharmaceutical substrates to enable other organs to be imaged, but its use was limited and high gamma energy and beta emission restricted the activity of each radiopharmaceutical used, leading to long acquisition times and degraded images. As a pure gamma emitter of 140 keV and with a 6-h half-life, Technetium-99m is a better radionuclide and images a wider range of bodily organs. However, its short half-life also requires it to be eluted from its mother radionuclide, Mo-99, in a generator, delivered weekly from radiopharmaceutical companies who obtain the Mo-99 in liquid form from high-flux research reactors. All went well till around 2007, when the NRU Reactor in Canada was closed and all other reactors went down for various periods for unrelated problems, leading to widespread Mo-99 shortages. Although the reactors have since recovered, they are 48 to 57 years old, and it seems that few governments have made any future provision such as building replacement reactors. PMID:22557795
Technetium99m-Labeled N-(2-Hydroxypropyl) Methacrylamide Copolymers: Synthesis, Characterization, and in Vivo Biodistribution
Amitava Mitra; Anjan Nan; Hamidreza Ghandehari; Edwina McNeil; Justin Mulholland; Bruce R. Line
Purpose. To synthesize novel technetium-99m (99mTc)-labeled N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers and characterize the effect of charge and molecular weight on their biodistribution in SCID mice.
Joint scintigraphy using technetium-99m pyrophosphate in experimental hemarthrosis
Salimi, Z.; Vas, W.; Restrepo, G.
To determine the validity of a method for induction of experimental hemarthrosis in dogs and for the nuclear imaging of hemarthrosis, serial technetium-99m pyrophosphate ((/sup 99m/Tc)PYP) flow and blood-pool scans were performed monthly in eight dogs who received bi-weekly injections of autologous blood into their femoro-tibial joints (also called stifle joint). In four control dogs, one joint was injected with saline while the other joint received only a sham injection. In addition, two dogs received intra-articular injections of autologous blood into their right stifle joint and saline into their left stifle joint. These dogs were studied with /sup 99m/TcO/sub 4/ joint scintigraphy at monthly intervals. The dogs were periodically taken out of the study and explored surgically. Pathologic examination of synovial tissue was performed. Serial radiographs were also obtained and correlated with the scan and surgical findings. There was a striking abnormal increase in blood-pool activity of (/sup 99m/Tc)PYP in the treated stifle joints, commencing at the first examination after 1 mo of blood injections and continuing for the length of the study. All radiographs showed only minimal joint space widening and some soft-tissue swelling. On pathologic examination, both grossly and microscopically, there was profuse pannus formation, with intense inflammatory infiltrate replacing much of the subsynovial fat. The scintigraphic findings correlated well with these pathologic findings. This study not only validates this method for simulating hemophilic hemarthrosis but also suggests that (/sup 99m/Tc)PYP joint scintigraphy is a simple, and noninvasive method for monitoring the early changes in hemophilic arthropathy and is superior to pertechnetate imaging for this disease process.
Detection of alveolar epithelial injury by Tc99m DTPA radioaerosol inhalation lung scan in rheumatoid arthritis patients
Berna Okudan; Mehmet ?ah?n; Feride Meltem ųzbek; Ali ▄mit Kesk?n; Erkan C³re
Rheumatoid arthritis (RA) is a systemic autoimmune disorder primarily involving the joints. Lung alterations in RA may be\\u000a primary or secondary to pharmacological treatments and may involve the alveoli, interstitium, airways and\\/or pleura. Technetium-99m\\u000a diethylenetriaminepentaacetic acid (Tc-99m DTPA) aerosol inhalation scintigraphy is a sensitive and noninvasive test commonly\\u000a employed to assess pulmonary epithelial membrane permeability. The purpose of the this
Technetium99m labelling of the anti-tumour antibody PR1A3 by photoactivation
Maria A. Stalteri; Stephen J. Mather
Irradiation of antibody with ultraviolet light leads to reduction of disulphide bonds. Thus irradiation can be used to generate free thiols prior to direct labelling of antibody with technetium-99m, and has a potential advantage over methods using chemical reducing agents such as mercaptoethanol or tin, in that no purification step is needed to remove excess reducing agent. We have used
Scintimammography with technetium-99m tetrofosmin in the diagnosis of breast cancer and lymph node metastases
Luigi Mansi; Pier Francesco Rambaldil; Eugenio Procaccini; Fernando Di Gregorio; Adelina Laprovitera; Biagio Pecori; Walter Del Vecchio
The aim of the study was to evaluate the possible role of scintimammography (SMM) with technetium-99m tetrofosmin in breast cancer. Thirty-three patients with breast disease and ten normal controls were included in the study. Planar scintigraphic images in supine anterior, prone lateral and lateral views, with the patient lying in lateral recumbency, were acquired. A qualitative analysis evaluating both breasts
Extraction and retention of technetium-99m Q12, technetium-99m sestamibi, and thallium-201 in isolated rat heart during coronary acidemia
Anthony J. McGoron; Myron C. Gerson; Danuta S. Biniakiewicz; Nancy J. Roszell; Lee C. Washburn; Ronald W. Millard
.ĀĀ Technetium-99m Q12 and 99mTc-sestamibi are cationic lipophilic myocardial perfusion imaging tracers. Because myocardium in areas of ischemia becomes\\u000a acidotic, experiments were designed to differentiate the effects of myocardial perfusate pH on radiotracer extraction and\\u000a retention independent of substrate availability. We hypothesized that 99mTc-Q12 and 99mTc-sestamibi single-pass uptake and retention would be unaffected by a modest reduction in coronary perfusate
Extracranial metastatic glioblastoma: Appearance on thallium-201-chloride/technetium-99m-HMPAO SPECT images
Carvalho, P.A.; Schwartz, R.B.; Alexander, E. III; Loeffler, J.S.; Zimmerman, R.E.; Nagel, J.S.; Holman, B.L. (Brigham and Women's Hospital, Boston, MA (USA))
Sequential thallium-201-chloride and technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) images were obtained in a patient with extracranial metastatic glioblastoma multiforme. Thallium-201 uptake was high (three times the scalp background) in all pathologically confirmed extracranial metastases and moderate (1.6 times scalp background) intracranially, where most biopsy specimens showed gliosis with scattered atypical astrocytes. Technetium-99m-HMPAO uptake was decreased intracranially in the right frontal and parietal lobes which had been irradiated. It was also decreased in one well-encapsulated scalp lesion and high in another scalp mass with less defined borders. Possible mechanisms of tumor uptake of these agents are reviewed.
The value of technetium99m pyrophosphate scanning in the diagnosis of myocardial contusion
Rodriguez, A.; Shatney, C.
Twelve patients who sustained significant blunt chest trauma and had abnormal electrocardiographic changes unrelated to hypotension, hypoxia, or pre-existing myocardial disease were studied prospectively during a one-year period. The patients were divided into two groups on the basis of serum creatine phosphokinase (CPK)/MB isoenzyme concentrations: Group A (six patients) had normal CPK/MB isoenzymes (less than 8 IU), and Group B (six patients) had elevated CPK/MB isoenzymes (greater than 8 IU). All patients underwent cardiac scanning with technetium99m pyrophosphate. All studies were interpreted as normal. These data suggest that technetium99m pyrophosphate scanning is not a reliable adjunctive test to confirm myocardial contusion in patients with significant blunt trauma of the chest. However, the diagnosis of myocardial contusion in such patients can be established by the presence of abnormal electrocardiographic changes associated with an elevation of the serum CPK/MB isoenzyme concentration.
Radioimmunoscintigraphy of ovarian tumours with technetium-99m labelled monoclonal antibody-170: first clinical experiences
Christof Alexander; Carlos E. Villena-Heinsen; Ludwin Trampert; Sabine Lung-Kurt; Erich Oberhausen; Carl-Martin Kirsch; Werner Schmidt
The recently developed technetium-99m-labelled monoclonal antibody-170 (MAb-170) was designed for diagnostic use in patients suffering from gynaecological adenocarcinoma. Following in vitro studies which showed immunoreactivity of this antibody to more than 90% of human adenocarcinomas, the present investigation was initiated to verify its usefulness for radioimmunoscintigraphy of ovarian tumours. Most of the 30 patients participating in this study underwent immunoscintigraphy
Cardiac and pleuropulmonary AL amyloid imaging with technetium-99m labelled aprotinin
Carlo Aprile; Gabriella Marinone; Raffaella Saponaro; Chiara Bonino; Giampaolo Merlini
Antiproteases are known to be present in amyloid deposits. We evaluated the possibility of using an anti-serine protease (aprotinin) labelled with technetium-99m (TcA), usually employed as a cortical renal tracer, for the imaging of amyloid deposits. Because of the known high uptake of TcA by the kidneys, we limited our analysis to extra-abdominal amyloid localizations. We report the scintigraphic findings
The use of Technetium-99m stannous pyrophosphate imaging as an index of myocardial infarctionĀ
Sanford, Jeffrey Clayton
for the degree of MASTER OF SCIENCE August 1981 Major Subject: Veterinary Physiology THE USE OF TECHNETIUM-99m STANNOUS PYROPHOSPHATE IMAGING AS AN INDEX OF MYOCARDIAL INFARCTION A Thesis by JEFFREY CLAYTON SANFORD Approved as to style and content by... infarction include electrocardiographic studies, analysis of circulating enzyme levels, gross necropsy grading sys- tems, a. nd histopathologic assessment. After simulating myo- cardial infarction with a treatment regime of isopro- terenol...
Is technetium-99 m-pyrophosphate scintigraphy valuable in the diagnosis of cardiac amyloidosis?
A. Hartmann; J. Frenkel; R. Hopf; R. P. Baum; G. S. Hoer; M. Schneider; M. Kaltenbach
Amyloidosis is a systemic disease frequently involving the myocardium and leading to functional disturbances of the heart. Amyloidosis can mimic other cardiac diseases. A conclusive clinical diagnosis of cardiac involvement can only be made by a combination of different diagnostic methods. In 7 patients with myocardial amyloidosis we used a combined first-pass and static scintigraphy with technetium-99 m-pyrophosphate. There was
Localization of technetium-99m-glucarate in zones of acute cerebral injury
H. Yaoita; T. Uehara; A. L. Brownell; C. A. Rabito; M. Ahmad; B. A. Khaw; A. J. Fischman; H. W. Strauss
The potential structural similarity of technetium-99m-labeled glucaric acid (99mTc-glucarate) to that of fructose suggests that this agent may enter cells by a sugar transport system. Studies with LLC-PK1 cells demonstrated inhibition of 99mTc-glucarate uptake by fructose, confirming this potential relationship. Since anaerobic metabolism can use either glucose or fructose, we hypothesized that 99mTc-glucarate may concentrate in areas of acute ischemic
A miniaturized rapid paper chromatographic procedure for quality control of technetium-99m sestamibi
Mohan Patel; Samy Sadek; Shawkat Jahan; Azu Owunwanne
A miniaturized rapid paper chromatographic technique (MRPC) for quality control of a technetium-99m sestamibi preparation was developed and compared with the manufacturer's and Hung et al. techniques. The MRPC system involves the use of 6.0ū0.5 cm Whatman 3MM paper strip developed in ethyl acetate. The procedure was completed within 3 min while that of the manufacturer and Hung techniques took
Brain PET and technetium-99mECD SPECT imaging in Lhermitte-Duclos disease
K. Ogasawara; S. Yasuda; T. Beppu; M. Kobayashi; M. Doi; K. Kuroda; A. Ogawa
Two patients with Lhermitte-Duclos disease were evaluated by brain positron emission tomography (PET) and technetium-99m-ethyl cysteinate dimer (99mTc-ECD) single-photon emission computed tomography (SPECT). In the lesions in both patients, hyperperfusion was detected on cerebral blood flow images obtained by PET, and hyperactivity by standard 99mTc-ECD SPECT. Dynamic 99mTc-ECD SPECT images demonstrated a plateau of activity in each lesion. These findings
MyocardialInfarctionin Dogs with Technetium.99m-Glucaric Acid
Cesare Orlandi; Paul D. Crane; D. Scott Edwards; Steven H. Platts; Lori Bernard; Joel Lazewatsky; Martin J. Thoolen
Recentdatahavegenerated someinterestin technetium 99m- (@ŌĆśTc) glucanc acid as an in vivo viability marker. Westudied@ŌĆ£Tc-glucaric acidretention incanine models of myocardialischemia(20-mmocclusion of the LAD\\/40- mm reperfusion),acute mycardialinfarction(Ml)(90-mm LAD occlusion\\/3-hr reperfusion),and chronic Ml (90-mm occlusionandeither48-hror 10-dayreperfusion).Regional myocardialblood flow was measuredby radiolabeledmi crospheres. No preferential uptakeof glucaricacid was observed in ischemic but viable myocardium.The corn poundshowedhighaffinityfor necroticmyocardial tissue for severaldays followinginjury.The preferentialuptake in infarcted
Technetium-99m-HIDA visualization of an obstructed gallbladder via an accessory hepatic duct
Reimer, D.E.; Donald, J.W.
Technetium-99m-labeled iminodiacetic acid (HIDA) and paraisopropyliminodiacetic acid (PIPIDA) scintigraphy after sonographic evaluation of the gallbladder have been advocated recently for the diagnosis of acute obstructive cholecystitis and cholelithiasis. Several authors have stated or inferred that gallbladder visualization with /sup 99m/Tc-HIDA excludes acute cholecystitis and cystic duct obstruction. We describe a patient with surgically proven cystic duct obstruction whose gallbladder visualized on a /sup 99m/Tc-HIDA scan via an accessory hepatic duct which directly entered the gallbladder.
Routes for supply of technetium-99m for diagnostic nuclear medicine
Goeij, J.J.M. de [Interfaculty Reactor Institute, Delft (Netherlands)
Technetium-99m is the most frequently used radio nuclide in diagnostic nuclear medicine. Although competing noninvasive diagnostic techniques are emerging, the prospects for the next decades are that {sup 99m}Tc will continue to play an indispensable role in diagnostic medicine. However, this applies only when the requirements of a reliable, cheap, frequent, and worldwide supply of {sup 99m}Tc to hospitals are met. This latter issue has been frequently addressed in recent years in publications and presentations at scientific meetings. This paper presents an overview of current and future methods to supply {sup 99m}Tc.
Radio-UHPLC: a tool for rapidly determining the radiochemical purity of technetium-99m radiopharmaceuticals?
Kryza, David; Janier, Marc
Determining the radiochemical purity (RCP) of technetium-99m ((99m)Tc) radiopharmaceuticals using the method described in the package insert is a time-consuming process, requiring particular attention in order to achieve accurate RCP results. The purpose of this study was to evaluate whether radio-ultra high performance liquid chromatography (radio-UHPLC) may be an alternative method for RCP testing of (99m)Tc-tetrofosmin, (99m)Tc-MAG3 and (99m)Tc-sestamibi. Results obtained using radio-UHPLC were in excellent agreement with the standard method, with total analysis time being reduced to less than 3 min. PMID:23681064
Technetium-99m pyrophosphate imaging in acute renal failure associated with nontraumatic rhabdomyolysis
Patel, R.; Mishkin, F.S.
Technetium-99m pyrophosphate (Tc-PYP) imaging was performed in five patients with acute renal failure associated with nontraumatic rhabdomyolysis. Four patients had phencyclidine intoxication and one had viral pneumonia. During the acute phase, marked uptake of pyrophosphate was seen in all patients in several muscle groups, but always in the thigh adductors. The results show that phencyclidine intoxication can result in diffuse muscle uptake of Tc-PYP without overt evidence of muscle injury. Tc-PYP imaging may provide a clue to the cause of acute renal failure in patients with suspected rhabdomyolysis in whom elevations of serum creatine phosphokinase concentrations are equivocal.
Technetium-99m-labeled nanofibrillar cellulose hydrogel for in vivo drug release.
Laurķn, Patrick; Lou, Yan-Ru; Raki, Mari; Urtti, Arto; Bergstr÷m, Kim; Yliperttula, Marjo
Nanoscale celluloses have recently gained an increasing interest in modern medicine. In this study, we investigated the properties of plant derived nanofibrillar cellulose (NFC) as an injectable drug releasing hydrogel in vivo. We demonstrated a reliable and efficient method of technetium-99m-NFC labeling, which enables us to trace the in vivo localization of the hydrogel. The release and distribution of study compounds from the NFC hydrogel after subcutaneous injection in the pelvic region of BALB/c mice were examined with a multimodality imaging device SPECT/CT. The drug release profiles were simulated by 1-compartmental models of Phoenix« WinNonlin«. The NFC hydrogel remained intact at the injection site during the study. The study compounds are more concentrated at the injection site when administered with the NFC hydrogel compared with saline solutions. In addition, the NFC hydrogel reduced the elimination rate of a large compound, technetium-99m-labeled human serum albumin by 2 folds, but did not alter the release rate of a small compound (123)I-?-CIT (a cocaine analogue). In conclusion, the NFC hydrogels is easily prepared and readily injected, and it has potential use as a matrix for controlled release or local delivery of large compounds. The interactions between NFC and specific therapeutic compounds are possible and should be investigated further. PMID:25245005
The Use of Radioactive Aerosols in the Ventilation Study of Persons Exposed to Air Pollution from the Oil Well Fires in Kuwait
A. Owunwanne; K. Al-ZaÆabi; S. Mahussain; M. W. Dawoud; M. Tuli; K. Nawaz; A. Ghali; S. Baig; S. Jahan
The permeability of alveolar-capillary membrane of persons exposed to smoke from oil well fires in Kuwait is studied using a nuclear medicine imaging technique. This involves inhalation of radioactive aerosols generated from technetium-99m diethylenetriamine pentacetate (99mTc DTPA). A total of 100 subjects were divided into four groups. The groups were classified into oil field workers, subjects who were in Kuwait
Evaluation of hypertensive patients by means of captopril enhanced renal scintigraphy with technetium-99m DTPA
Dondi, M.; Franchi, R.; Levorato, M.; Zuccala, A.; Gaggi, R.; Mirelli, M.; Stella, A.; Marchetta, F.; Losinno, F.; Monetti, N.
One-hundred five hypertensive patients underwent conventional renal scintigraphy followed 2 or 3 days later by Captopril-enhanced renal scintigraphy, performed 1 hr after premedication with 50 mg of Captopril per os. All patients were then submitted to renal arteriography, performed within 15-30 days. Fifty-five patients had no renal artery stenosis, 29 had unilateral disease, and 21 bilateral. Overall, 34/37 patients were diagnosed by the provocative test as having at least one renal artery affected by a stenosis greater than 50%. Of those with no stenosis (n = 55) or stenosis less than 50% (n = 13) only two cases were falsely positive. Thus sensitivity was 92% and specificity 97%. For single kidney identification with stenosis greater than 50%, sensitivity of renal scintigraphy after Captopril administration was 94% and specificity 98%. Captopril enhanced renal scintigraphy is thus suggested as the first test to be performed in hypertensive patients referred for renal scintigraphic studies. Only those cases with equivocal results require a baseline study for better assessment.
Incidental Detection of Situs Inversus Totalis in a Young Female by Technetium99m Mebrofenin (HIDA) Nuclear Imaging
Shoukat H. Khan; Mushood Nabi; Musadiq A. Khan
Situs inversus totalis, a not so uncommon congenital positional anomaly can be a diagnostic problem at times. We present a case of situs inversus totalis that was picked up during Technetium-99m Mebrofenin (HIDA) hepatobiliary nuclear scan of a young female patient with pain abdomen.
Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model.
Tang, Cheng; Wang, Feng; Hou, Yanjie; Lu, Shanshan; Tian, Wei; Xu, Yan; Jin, Chengzhe; Wang, Liming
Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n?=?12). Rabbits in the control group were injected with sterile saline (n?=?12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4?hours after injection of technetium-99m-labeled annexin V (150?MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ▒ 0.29 in the early phase and 2.19 ▒ 0.34 in the delay phase, both of which were significantly higher than those of the control group (P?=?0.03 and P?=?0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model. PMID:26060446
Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model
Tang, Cheng; Wang, Feng; Hou, Yanjie; Lu, Shanshan; Tian, Wei; Xu, Yan; Jin, Chengzhe; Wang, Liming
Abstract Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n?=?12). Rabbits in the control group were injected with sterile saline (n?=?12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4?hours after injection of technetium-99m-labeled annexin V (150?MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ▒ 0.29 in the early phase and 2.19 ▒ 0.34 in the delay phase, both of which were significantly higher than those of the control group (P?=?0.03 and P?=?0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model.
Technetium-99m glucoheptonate imaging in lung cancer and benign lung diseases: concise communication
Passamonte, P.M.; Seger, R.M.; Holmes, R.A.; Hurst, D.J.
Technetium-99m glucoheptonate (Tc-GHA) uptake was prospectively studied in 58 patients with newly diagnosed lung cancer and in 20 patients with pulmonary inflammatory disease or metastatic carcinoma. Fifty-three (91%) primary tumors accumulated Tc-GHA: squamous cell 20/22, adenocarcinoma 7/7, large cell 10/11, and small cell 16/18. Intensity of tumor uptake was greatest in small-cell cancer. Supraclavicular metastases were detected in two patients. Fourteen patients with mediastinal evaluation by Tc-GHA imaging and trispiral tomography underwent mediastinoscopy or thoracotomy. Five of ten patients with negative mediastinum by tomography and Tc-GHA imaging showed metastases by biopsy (false- negative Tc-GHA). Less intense accumulation of Tc-GHA was observed in 18/20 cases of pulmonary inflammatory disease or pulmonary metastases. Although Tc-GHA accumulates by an unknown mechanism in primary lung cancer, we cannot recommend its use in detecting mediastinal spread of lung cancer due to its unacceptably high false-negative rate.
Technetium-99m HM-PAO-labeled leukocytes in detection of inflammatory lesions: Comparison with gallium-67 citrate
Vorne, M.; Soini, I.; Lantto, T.; Paakkinen, S. (Paeijaet-Haeme Central Hospital, Lahti (Finland))
Forty-three patients with suspected benign, inflammatory, or infectious diseases were imaged with ({sup 99m}Tc)HM-PAO-labeled leukocytes and ({sup 67}Ga)citrate. Technetium-99m leukocytes showed 22 true-positive, no false-positive, 19 true-negative, and two false-negative findings and ({sup 67}Ga)citrate 23, 7, 12 and 1, respectively. The sensitivity, specificity, and accuracy values with {sup 99m}Tc leukocytes were 92%, 100%, and 95%, and with ({sup 67}Ga)citrate 96%, 63%, and 81%. Technetium-99m leukocyte scintigraphy has a promising future in comparison with ({sup 67}Ga)citrate because of the ready availability of ({sup 99m}Tc)HM-PAO, the good image quality, more rapid results (within few hours), and the lower radiation exposure to the patient with {sup 99m}Tc leukocytes. The usefulness of {sup 99m}Tc leukocytes in chronic osteomyelitis needs further evaluation.
Is the addition of ECG gating to technetium-99m sestamibi SPET of value in the assessment of myocardial viability?
Patricio Gonzfilez; Teresa Massardo; Alejandra Mu±oz; Josefina Jofrķ; Alfredo Rivera; Jorge Yovanovich; Emilio Maiers; Francisco Ayala; Pamela Humeres; Alfredo RamĒrez; Marco Arriagada; Aquiles Zavala
The main goal of this study was to evaluate whether the addition of ECG gating to technetium-99m sestamibi single-photon emission tomography (SPET) perfusion imaging assists the prediction of recovery of regional wall motion abnormalities after revascularization. Thirty-six patients with coronary artery disease were included in the study. All had wall motion abnormalities, and 31 (86%) had a clinical history of
Brain single-photon emission tomography with technetium-99m hexamethylpropylene amine oxime in adolescents with initial-stage schizophrenia
Juan F. Batista; MarĒa C. Galiano; Leonel A. Torres; MarĒa C. Hernßndez; Felix Sosa; Alejandro Perera; Marilyn Pķrez
The objective of this study was to search for regional cerebral blood flow (rCBF) abnormalities in adolescents with initial-stage schizophrenia by means of brain single-photon emission tomography (SPET) using technetium-99m hexamethylpropylene amine oxime (HMPAO). SPET studies were performed on a homogeneous sample of 15 carefully selected adolescents with a recent diagnosis of schizophrenia, and without previous electroconvulsive or antipsychotic drug
Brain single-photon emission tomography using technetium-99m bicisate (ECD) in a case of complex partial seizure
Christian Menzel; Frank GrOnwaldl; Laszlo Pavics; Andreas Hufnagel; Brigitte Stawovy; Karl Reichmann; Christian E. Elger; Hans J. Biersack
The clinical application of technetium-99m bicisate (ethyl cysteinate dimer, ECD) for ictal and interictal studies of regional cerebral blood flow (rCBF) in a patient suffering from medically intractable simple and complex partial seizures is reported. The interictal study was performed 60 min p.i. and the ictal studies were performed at 60 min p.i. using an annular crystal single-photon emission tomography
Technetium99m sestamibi brain single-photon emission tomography for detection of recurrent gliomas after radiation therapy
C. Soler; P. Beauchesne; K. Maatougui; T. Schmitt; F. G. Barral; D. Michel; F. Dubois; J. Brunon
.ĀĀ Technetium-99m sestamibi (MIBI), an alternative radiopharmaceutical for myocardial perfusion imaging, has also been proposed\\u000a for use as an imaging agent for various tumours, including breast cancer, lung cancer, lymphomas, melanomas and brain tumours.\\u000a After routine radiation therapy, deteriorating clinical status or treatment failure may be due to either radiation-induced\\u000a changes or recurrent tumour. Computed tomography and magnetic resonance imaging
Primary breast cancer imaging with technetium-99m sestamibi and its relation with P-glycoprotein overexpression
Jean-Luc Moretti; Hervķ Azaloux; Dominique Boisseron; Jean-Claude Kouyoumdjian; Jacques Vilcog
The aim of this preliminary study was to evaluate retrospectively sestamibi scintigraphy in relation to the presence of the 170-kDa P-glycoprotein (Pgp), which represents an expression of multidrug resistance in patients with primary breast cancer. Fifteen women (age range 37¢76 years) were referred for technetium-99m sestamibi scintigraphy because of suspicious breast lesions detected by mammography and ultrasonography, and subsequently assessed
The effect of drugs on the labeling of blood elements with technetium-99m.
Braga, A C; Oliveira, M B; Feliciano, G D; Reiniger, I W; Oliveira, J F; Silva, C R; Bernardo-Filho, M
The influence of drugs on the labeling of red blood cells and plasma proteins with 99mTc has been reported. Any drug, which alters the labeling of the tracer, could be expected to modify the disposition of the radiopharmaceuticals. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. We have evaluated the effect of Thuya occidentalis, Peumus boldus and Nicotiana tabacum (tobacco) extracts on the labeling of RBC and plasma and cellular proteins with 99mTc. Blood was incubated with the drugs. Stannous chloride (SnCl2) solutions and 99mTc were added. Plasma (P) and blood cells (BC) were separated. The percentage of radioactivity (%ATI) bound to P and BC was determined. The %ATI on the plasma and cellular proteins was also evaluated by precipitation of P and BC samples with trichloroacetic acid (TCA) and isolation of soluble (SF) and insoluble (IF) fractions. The analysis of the results shows that there is a decrease in %ATI (from 97.64 to 75.89 percent) in BC with Thuya occidentalis extract. The labeling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due either a direct or indirect effect (reactive oxygen species) of tobacco. The analysis of radioactivity in samples of P and BC isolated from samples of whole blood treated with Peumus boldus showed a rapid uptake of the radioactivity by blood cells in the presence of the Peumus boldus, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique. PMID:10903389
Development of animal models for evaluation of technetium-99m renal tubular function agents
Eshima, D.
Diamide dimercaptide (N/sub 2/,S/sub 2/) and triamide mercaptide (N/sub 3/S) complexes of technetium-99m were shown to have potential use as a new class of renal tubular function agents. The biological evaluation of a number of these new Tc-99m chelating agents was performed in order to develop an optimal animal strategy for the screening of these agents as well as other potential complexes. Various animal models were studied to determine the potential correlation of the rate of renal clearance and specificity for the renal transport system between the various animal species and humans. There was no single animal species which could routinely predict the performance of the complexes in humans. Therefore, the use of a select number of performance parameters, which were obtained from studies in the mouse, rat or dog were utilized to develop a set of criteria to predict the performance in humans. The use of these animal models minimized extrapolation errors, if limitations were placed on the amount of information which would be utilized from each of them. There were a number of complexes which appeared promising when evaluated in view of these species limitations. The evaluation of Tc-99m-mercaptoacetylglycylglycylglycine (Tc-99m-MAG/sub 3/) was found to perform well in all of the various animal models. Tc-99m-MAG/sub 3/ was therefore utilized to develop an understanding for its pathway of elimination. The results from these studies show that Tc-99m-MAG/sub 3/ is cleared from the body by the kidney primarily by renal tubular secretion processes.
Localization of technetium-99m-glucarate in zones of acute cerebral injury
Yaoita, H.; Uehara, T.; Brownell, A.L.; Rabito, C.A.; Ahmad, M.; Khaw, B.A.; Fischman, A.J.; Strauss, H.W. (Massachusetts General Hospital, Boston (USA))
The potential structural similarity of technetium-99m-labeled glucaric acid (99mTc-glucarate) to that of fructose suggests that this agent may enter cells by a sugar transport system. Studies with LLC-PK1 cells demonstrated inhibition of 99mTc-glucarate uptake by fructose, confirming this potential relationship. Since anaerobic metabolism can use either glucose or fructose, we hypothesized that 99mTc-glucarate may concentrate in areas of acute ischemic injury. To test this hypothesis, 63 adult rats with middle cerebral artery (MCA) occlusion followed by reperfusion were injected with 99mTc-glucarate and in vivo and ex vivo images were acquired. Seven animals were also studied with 18FDG and high resolution PET imaging. The radionuclide images were compared to the results of triphenyl tetrazolium chloride (TTC) staining and conventional histopathology. Thirty-five rats had significant accumulation of 99mTc-glucarate and no TTC staining (indicating infarction) in the involved hemisphere. Of the remaining 28 rats with TTC staining (suggesting viability) of the involved hemisphere, 16 (57%) had 99mTc-glucarate accumulation. In the seven rats that were studied with both 99mTc-glucarate and 18FDG, 99mTc-glucarate accumulated at the center of the occluded MCA territory while 18FDG activity was decreased in this region. These results suggest that 99mTc-glucarate is a sensitive marker of acute severe cerebral injury, but its mechanism of localization is probably different from that of 18FDG.
Assessment of inflammatory bowel disease activity by technetium 99m phagocyte scanning
Pullman, W.E.; Sullivan, P.J.; Barratt, P.J.; Lising, J.; Booth, J.A.; Doe, W.F.
Autologous technetium 99m-labeled phagocyte scanning has been used to assess disease activity in inflammatory bowel disease in 51 consecutive patients. Strong correlations were found between the 24-h fecal excretion of isotope and the histologic score of mucosal biopsy specimens (rS = 0.84, p less than 0.001, where rS is Spearman's rank correlation coefficient), and between the 24-h fecal excretion of isotope and a clinical inflammatory bowel disease activity index based on the Crohn's disease activity index (rS = 0.87, p less than 0.001). To develop a clinically useful and objective measure of inflammatory bowel disease activity that did not require a 24-h stool collection, the intensity of bowel uptake on scanning was graded visually from 0 to 4, a ratio of count rates for the region of interest to the iliac crest reference region was calculated, and the rapidity of labeled phagocyte uptake into inflamed bowel was measured as the peak uptake time. Visual grading of disease activity on the scans was validated by comparing it with the ratio of count rates from inflamed bowel regions of interest and those from the iliac crest reference region. The ratio of count rates showed a significant correlation with the clinical disease activity index (r = 0.75, p less than 0.001). The visual scan grade also correlated well with the clinical activity index (r = 0.87, p less than 0.001). Count rates from hourly scans were also used to calculate the time of peak uptake of counts for a given region of interest. There was a strong negative correlation between this peak uptake time and the fecal excretion of isotope (rS = -0.81, p less than 0.001), a clinical activity index (r = -0.60, p less than 0.001), and the histologic score of the mucosal biopsy specimens (r = -0.84, p less than 0.001).
Development of nonreducible technetium-99m(III) cations as myocardial perfusion imaging agents: initial experience in humans
Deutsch, E.; Vanderheyden, J.L.; Gerundini, P.; Libson, K.; Hirth, W.; Colombo, F.; Savi, A.; Fazio, F.
A series of 15 nonreducible technetium-99m (III) complexes of formula tr-(/sup 99m/TcL(Y)2)+ has been prepared by a general synthetic route based on reductive addition of Y to the technetium-99m (/sup 99m/Tc) intermediate (/sup 99m/TcL(O))+. In these complexes, selected for potential use as myocardial imaging agents, L represents one of the two tetradentate Schiff base ligands N,N'-ethylenebis(acetylacetone iminato), (en), or N,N'-propylene-1,2-bis(acetylacetone iminato), (pn), while Y represents a monodentate phosphine, phosphite or isonitrile ligand as exemplified by P(CH3)3, P(OCH3)3 and CN-C(CH3)3. Of these 15 complexes, several with octanol/saline partition coefficients in the range 0.04-20 exhibit significant myocardial uptake in rats and dogs. Of these, none exhibit detectable myocardial washout, providing strong support for the hypothesis that myocardial washout occurs only for those /sup 99m/Tc(III) cations that undergo in vivo reduction to the neutral /sup 99m/Tc(II) form. Evaluation of the prototypical complex tr-(/sup 99m/Tc(en)(P(CH3)3)2)+ in seven normal volunteers and patients establishes that it is only a mediocre myocardial imaging agent in man.
Radionuclide imaging for breast cancer diagnosis and management: is technetium-99m tetrofosmin uptake related to the grade of malignancy?
Silov, G³ler; Ta?demir, Arzu; Ozdal, Ay?eg³l; Erdo?an, Zeynep; Ba?bu?, Esma Mehtap; Arslan, Ay?e Esra; Turhal, Ozg³l
There are different scoring systems available for determining the grade of breast cancer malignancy. Breast cancer tumors have been described for grades 1-3 using the modified Nottingham-Bloom-Richardson grading system. Determining the grade is very important for the clinicians to choose the best treatment options. Technetium-99m methoxy isobutyl isonitrile ((99m)Tc-MIBI) and pentavalent (99m)Tc-dimercaptosuccinic acid ((99m)Tc(V)-DMSA) scintigraphy have been used and are under evaluation for being prognostic factors for breast carcinoma. Radionuclide breast imaging not only visualizes the lesion site but also reflects specific biological and functional lesion features, including perfusion, proliferative potential, metabolic activity and receptor status. PMID:24997077
Early estimation of acute myocardial infarct size soon after coronary reperfusion using emission computed tomography with technetium-99m pyrophosphate
Hashimoto, T.; Kambara, H.; Fudo, T.; Tamaki, S.; Nohara, R.; Takatsu, Y.; Hattori, R.; Tokunaga, S.; Kawai, C.
Early appearance of positive findings on a technetium-99m pyrophosphate scan has been shown to be associated with the presence of a reperfused acute myocardial infarction (AMI). Early technetium-99m pyrophosphate imaging was performed by emission computed tomography to evaluate reperfusion and to test the feasibility of estimating infarct size soon after coronary reperfusion based on acute positive tomographic findings. Twenty-seven patients with transmural AMI who were treated with intracoronary urokinase infusion followed by percutaneous transluminal coronary angioplasty underwent pyrophosphate imaging 8.7 +/- 2.1 hours after the onset of AMI. None of the 8 patients in whom reperfusion was unsuccessful had acute positive findings. Of 19 patients in whom reperfusion was successful, 17 had acute positive findings (p less than 0.001). In these 17, tomographic infarct volumes were determined from reconstructed transaxial images. The threshold for areas of increased pyrophosphate uptake within the infarct was set at 60% of peak activity by the computerized edge-detection algorithm. The total number of pixels in all transaxial sections showing increased tracer uptake were added and multiplied by a size factor and 1.05 g/cm3 muscle to determine infarct volume. The correlations of tomographic infarct volumes with peak serum creatine kinase (CK) levels (r = 0.82) and with cumulative release of CK-MB isoenzyme (r = 0.89) were good. Moreover, the time to positive imaging was significantly shorter than that to peak CK level (8.5 +/- 2.3 vs 10.4 +/- 2.2 hours, p less than 0.005).
Is furosemide administration effective in improving the accuracy of determination of differential renal function by means of technetium-99m DMSA in patients with hydronephrosis
Levent Kabasakal; Cuneyt Turkmen; Ozlem Ozmen; Nalan Alan; Cetin Onsel; Ilhami Uslu
It has been suggested that determination of differential renal function (DRF)using technetium-99m dimercaptosuccinic acid (DMSA) may lead to overestimation of the function of an obstructed kidney in patients with excretion abnormalities owing to pelvic retention of DMSA. Recently published guidelines have recommended use of furosemide injection when calculating DRF in these particular patients. The aim of this study was to
Monoclonal antibody BW431\\/26 labelled with technetium 99m and indium 111: an investigation of the biodistribution and the dosimetry in patients
P. Benz; E. Oberhausen; R. Berberich
As a competitive diagnostic tool for the detection of malignant tumours and other pathological conditions, monoclonal antibodies have long been established. Herein we give the biokinetic data of the antibody BW 431\\/26 and the consequent radiation dose to patients. These parameters were recorded in 39 patients, using the antibody labelled either with technetium 99m or indium 111. Remarkable differences were
Assessment of tumour necrosis and detection of mediastinal lymph node metastasis in bronchial carcinoma with technetium-99m sestamibi imaging: comparison with CT scan
Cumali Aktolun; Hikmet Bayhan; Yuksel Pabuccu; Hayati Bilgic; Huseyin Acar; Ramazan Koylu
Thirty-eight patients with four major types of bronchial carcinoma were studied to evaluate technetium-99m sestamibi imaging in the assessment of tumour necrosis and the detection of hilar and mediastinal lymph node metastasis. Quantitative analysis was also performed to ascertain whether tumour uptake values correlate with histological types of bronchial carcinoma. Of the patients, 34 showed tumour uptake on planar imaging
Usefulness of Technetium99m Hexamethylpropylene Amine Oxime-Labeled Leukocyte Scintigraphy to Detect Pancreatic Necrosis in Patients with Acute Pancreatitis
Antonio L¾pez; Leticia de la Cueva; MarĒa Jes·s MartĒnez; Fernando G¾mez; Tomßs Ripollķs; Ram¾n Sopena; Eduardo Moreno-Osset
Background: In acute pancreatitis (AP), pancreatic necrosis (PN) is an important local complication that can be identified by means of contrast-enhanced computed tomography (CECT). Pancreatic leukocyte infiltration is a significant pathogenic event in the development of PN that can be detected by labeled leukocyte scintigraphy (LLS). The aim of this study was to evaluate the utility of LLS with technetium-99m
Technetium-99m-labeled monoclonal antibodies for immunoscintigraphy. Simplified preparation and evaluation.
Thakur, M L; DeFulvio, J D
Ascorbic acid incubated with monoclonal antibodies (22 degrees C, 60 min, pH 6.5) at a molar ratio of 3500:1, reduced 2.7 +/- 0.2% of the available disulfides to sulfhydryl groups that strongly bind 99mTc, and provided greater than 95% labeling efficiency for several IgM, IgG and F(ab')2 antibodies. The colloid formation was consistently less than 3% and the stability of the tracer when challenged with DTPA and cysteine was excellent. The immunospecificity of labeled antibodies as determined by immobilized specific antigen assay was 84 +/- 1% for IgM and 82.6 +/- 1.1% for IgG antibodies. For in vivo evaluation in mice bearing experimental abscesses and tumors, corresponding 125I-labeled antibodies served as controls. The liver uptake was similar (P = 0.76 and P = 0.12) for 99mTc or 125I labeled antinuclear antibody TNT-1 in mice bearing abscesses as well as for 99mTc-TNT-1-F(ab')2 and 125I-TNT-1-F(ab')2 in mice bearing tumors. Higher but statistically insignificant (P = 0.08, 0.18, and 0.73) urinary excretion was noted for 99mTc-antibodies. For corresponding 99mTc- and 125I-labeled antibodies, the abscess to muscle ratios (3.3 +/- 0.5 vs. 3.4 +/- 0.8) and tumor to muscle ratios (10.04 +/- 4.4 vs. 10.54 +/- 3.0) were similar. The high 99mTc-TNT-1-F(ab')2 uptake permitted excellent scintigraphic visualization of tumors whereas the nonspecific 99mTc-HSA did not (tumor/muscle ratio: 2.4 +/- 0.3). This method is simple, reliable, and adaptable to an instant labeling technique. PMID:2013698
Comparative biodistribution studies of technetium-99?m radiolabeled amphiphilic nanoparticles using three different reducing agents during the labeling procedure.
Geskovski, Nikola; Kuzmanovska, Sonja; Simonoska Crcarevska, Maja; Calis, Sema; Dimchevska, Simona; Petrusevska, Marija; Zdravkovski, Pance; Goracinova, Katerina
Considering the confusing biodistribution data through the literature and few reported alerts as well as our preliminary biodistribution results, we decided to evaluate the interaction and interference of the commonly present (99m) Tc (technetium-99m)-stannic oxide colloid during the direct stannous chloride (99m) Tc-labeling procedure and to assess its influence on the biodistribution pattern of amphiphilic poly(lactic-co-glycolic acid) nanoparticles. In order to confirm our thesis, beside stannous chloride, we employed two different reducing agents that don't form colloidal particles. The use of sodium borohydride was previously reported in the literature, whereas sodium dithionite was adapted for the first time in the (99m) Tc direct labeling procedure for nanoparticles. The results in our paper clearly differentiate among samples with and without colloidal impurities originating from the labeling procedure with a logical follow up of the radiochemical, physicochemical evaluation, and biodistribution studies clarifying previously reported data on stannic oxide colloidal interference. (99m) Tc-nanoparticle complex labeled with sodium dithionite as reducing agent illustrated appropriate labeling efficacy, stability, and potential for further use in biodistribution studies thus providing solution for the problem of low-complex stability when sodium borohydride is used and colloidal stannic oxide interference for stannous chloride procedure. PMID:24339006
Technetium-99m bis (aminoethanethiol) complexes with amine sidechains--potential brain perfusion imaging agents for SPECT
Efange, S.M.; Kung, H.F.; Billings, J.; Guo, Y.Z.; Blau, M.
In an effort to develop new clinically useful technetium-99m bis(aminoethanethiol) ((/sup 99m/Tc)BAT) complexes for the evaluation of regional cerebral perfusion, two new BAT ligands containing amines in the sidechain were synthesized and subsequently complexed with /sup 99m/Tc to yield the target complexes: (/sup 99m/Tc)DEA and (/sup 99m/Tc)TMPDA. Each complex was obtained as mixtures of two isomers, syn and anti, which were separated chromatographically. In biodistribution studies, both isomers of (/sup 99m/Tc)TMPDA showed little uptake in the brain. In contrast, the brain uptake values at 2 and 15 min for (/sup 99m/Tc)DEA-anti were 0.99 and 0.26, whereas, the corresponding values for DEA-syn were 2.27, 0.64% dose/organ, respectively. Autoradiographic studies (in rats) using both isomers of (/sup 99m/Tc)DEA show a fixed regional distribution and a higher concentration of radioactivity in the gray matter relative to the white matter. Planar imaging using (/sup 99m/Tc)DEA-syn clearly demonstrates localization of the complex in the brain with a T 1/2 of 41 min, suggesting some potential for use with single photon emission computed tomography.
Modulation of the multidrug resistance P-glycoprotein: Detection with technetium-99m-sestamibi in vivo
Luker, G.D.; Fracasso, P.M.; Dobkin, J.; Piwnica-Worms, D. [Washington Univ. School of Medicine, St. Louis, MO (United States)
Overexpression of the multidrug resistance (MDR1) P-glycoprotein (Pgp) has been documented in nearly all forms of human cancers and increased levels of Pgp in some tumors correlate with poor response to treatment. Technetium-99m-sestamibi has recently been validated as a Pgp transport substrate. Pgp is also normally expressed along the biliary canalicular surface of hepatocytes and the luminal side of proximal tubule cells in the kidney, while not expressed in heart. Focused on these organs with known Pgp status, we present the findings on {sup 99m}Tc-sestamibi showed normal, prompt clearance of the radiotracer from the liver and kidneys relative to the heart. After administration of the Pgp modulator, {sup 99m}Tc-sestamibi was selectively retained in the liver and kidneys. Hepatobiliary and renal clearance of {sup 99m}Tc-sestamibi are Pgp-mediated, and inhibition of Pgp transport in these organs can be successfully imaged using {sup 99m}Tc-sestamibi in patients. Similar results might be expected with this and related radiopharmaceuticals for functional imaging of Pgp transport and modulation in tumors. 34 refs., 2 figs.
High-risk angina patient: identification by clinical features, hospital course, electrocardiography, and technetium-99m stannous pyrophosphate scintigraphy
Olson, H.G. (Univ. of California, Irvine); Lyons, K.P.; Aronow, W.S.; Stinson, P.J.; Kuperus, J.; Waters, H.J.
We evaluated 193 consecutive unstable angina patients by clinical features, hospital course and electrocardiography. All patients were managed medically. Of the 193 patients, 150 (78%) had a technetium-99m pyrophosphate (Tc-PYP) myocardial scintigram after hospitalization. Of these, 49 (33%) had positive scintigrams. At a follow-up of 24.9 +- 10.8 months after hospitalization, 16 of 49 patients (33%) with positive scintigrams died from cardiac causes, compared with six of 101 patients (6%) with negative scintigrams (p < 0.001). Of 49 patients with positive scintigrams, 11 (22%) had had nonfatal myocardial infarction at follow-up, compared with seven of 101 patients (7%) with negative scintigrams (p < 0.01). Age, duration of clinical coronary artery disease, continuing angina during hospitalization, ischemic ECG, cardiomegaly and a history of heart failure also correlated with cardiac death at follow-up. Ischemic ECG and a history of angina with a crescendo pattern also correlated with nonfatal infarction at follow-up. Patients with continuing angina, an ischemic ECG and a positive scintigram constituted a high-risk unstable angina subgroup, with a survival rate of 58% at 6 months, 47% at 12 months and 42% at 24 and 36 months. We conclude that the assessment of clinical features, hospital course, ECG and Tc-PYP scintigraphy may be useful in identifying high-risk unstable angina patients.
High-risk angina patient. Identification by clinical features, hospital course, electrocardiography and technetium-99m stannous pyrophosphate scintigraphy
Olson, H.G.; Lyons, K.P.; Aronow, W.S.; Stinson, P.J.; Kuperus, J.; Waters, H.J.
We evaluated 193 consecutive unstable angina patients by clinical features, hospital course and electrocardiography. All patients were managed medically. Of the 193 patients, 150 (78%) had a technetium-99m pyrophosphate (Tc-PYP) myocardial scintigram after hospitalization. Of these, 49 (33%) had positive scintigrams. At a follow-up of 24.9 +/- 10.8 months after hospitalization, 16 of 49 patients (33%) with positive scintigrams died from cardiac causes, compared with six of 101 patients (6%) with negative scintigrams (p less than 0.001). Of 49 patients with positive scintigrams, 11 (22%) had had nonfatal myocardial infarction at follow-up, compared with seven of 101 patients (7%) with negative scintigrams (p less than 0.01). Age, duration of clinical coronary artery disease, continuing angina during hospitalization, ischemic ECG, cardiomegaly and a history of heart failure also correlated with cardiac death at follow-up. Ischemic ECG and a history of angina with a crescendo pattern also correlated with nonfatal infarction at follow-up. Patients with continuing angina, an ischemic ECG and a positive scintigram constituted a high-risk unstable angina subgroup with a survival rate of 58% at 6 months, 47% at 12 months and 42% at 24 and 36 months. We conclude that the assessment of clinical features, hospital course, ECG and Tc-PYP scintigraphy may be useful in identifying high-risk unstable angina patients.
Effect of exercise on erythrocyte count and blood activity concentration after technetium-99m in vivo red blood cell labeling
Konstom, M.A. (New England Medical Center, Boston, MA); Tu'meh, S.; Wynne, J.; Beck, J.R.; Kozlowski, J.; Holman, B.L.
The effects of exercise on blood radiotracer concentration after technetium-99m in vivo red blood cell labeling was studied. After red blood cell labeling, 13 subjects underwent maximal supine bicycle exercise. Radioactivity, analyzed with a well counter, was measured in heparinized venous blood samples drawn at rest and during peak exercise. Changes in activity were compared with changes in erythrocyte count. Activity and erythrocyte counts increased in erythrocyte count (r=0.78), but did not correlate with either duration of exercise or maximal heart rate. Twenty minutes after termination of exercise, activity and erythrocyte count had decreased from peak exercise values but remained higher than preexercise values. In nine nonexercised control subjects, samples drawn 20 minutes apart showed no change in activity or in erythrocyte count. It was concluded that exercise increases blood activity, primarily because of an increase in erythrocyte count. During radionuclide ventriculography, blood activity must be measured before and after any intervention, particularly exercise, before a change in left ventricular activity can be attributed to a change in left ventricular volume.
Sequential functional imaging with technetium-99m hexakis-2-meth oxyisobutylisonitrile and indium-111 octreotide: can we predict the response to chemotherapy in small cell lung cancer?
J. L. Moretti; M. Caglar; C. Boaziz; N. Caillat-Vigneron; J. F. Morere
A case of small cell lung carcinoma (SCLC) demonstrating uptake on functional indium-111 octreotide scintigraphy is presented. Technetium-99m hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy clearly delineated an absence of radionuclide uptake at the tumour site. This suggested the presence of multidrug resistance-mediated P glycoprotein (Pgp) on tumour cells, which recognizes certain chemotherapeutic agents as well as MIBI as a substrate and avoids radionuclide
Automatic Quantitation of Regional Myocardial Wall Motion and Thickening From Gated Technetium99m Sestamibi Myocardial Perfusion Single-Photon Emission Computed Tomography
Guido Germano; Jacob Erel; Howard Lewin; Paul B. Kavanagh; Daniel S. Berman
Objectives. We developed an automatic quantitative algorithm for the measurement of regional myocardial wall motion and wall thickening from three-dimensional gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomographic images.Background. The algorithm measures the motion of the three-dimensional endocardial surface using a modification of the centerline method, as well as wall thickening using both geometry (gaussian fit) and partial volume
Evaluation of Outcome of Delayed Neurologic Sequelae after Carbon Monoxide Poisoning by Technetium99m Hexamethyl-propylene Amine Oxime Brain Single Photon Emission Computed Tomography
Il Saing Choi; Soon Kwan Kim; Sung Soo Lee; Young Chul Choi
Using brain computed tomography (CT) and single photon emission computed tomography (SPECT) with technetium-99m hexamethylpropylene amine oxime (99mTc HM-PAO) in 13 patients with delayed neurologic sequelae after carbon monoxide poisoning, we tried to evaluate the clinical outcome of delayed CO sequelae. Among the 13 initial brain CTs, seven showed low density in the cerebral white matter and one revealed hypodensity
A technetium-99m hexamethylpropylene amine oxime brain single-photon emission tomography study in adolescent patients with major depressive disorder
Ahmet Tutus; Mustafa Kibar; Seher Sofuoglu; Mustafa Basturk; Ali S. G÷n³l
.ĀĀ We have not encountered any brain single-photon emission tomography (SPET) study performed in adolescent depressed patients\\u000a in the literature. Therefore, we used technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) brain SPET in adolescent patients with major depressive disorder (MDD) to examine the possible changes in cerebral\\u000a perfusion and the possible association between perfusion indices and clinical variables. Fourteen adolescent out-patients\\u000a (nine
Early Hypoperfusion of Technetium99m Hexamethylprophylene Amine Oxime Brain Single Photon Emission Computed Tomography in a Patient with Carbon Monoxide Poisoning
Il Saing Choi; Myung Sik Lee
Single photon emission computed tomography (SPECT) with technetium-99m (99mTc) hexamethylprophylene amine oxime (HM-PAO) were repeatedly performed in a 55-year-old woman with carbon monoxide (CO) poisoning. The initial brain SPECT 10 days after anoxic insult showed focal hypoperfusion which appeared 20 days prior to the onset of delayed neurologic sequelae, and the findings of follow-up SPECTs correlated with the clinical course
Simultaneous acquisition of iodine-123 emission and technetium-99m transmission data for quantitative brain single-photon emission tomographic imaging
Katsuhiko Ogasawara; Jun Hashimoto; Koichi Ogawa; Atsushi Kubo; Nobutoku Motomura; Hyoji Hasegawa; Takashi Ichihara
.ĀĀ The aim of this study was to obtain quantitative iodine-123 brain single-photon emission tomographic (SPET) images with scatter\\u000a and attenuation correction. We used a triple-headed SPET gamma camera system equipped with fan-beam collimators with a technetium-99m\\u000a line transmission source placed at one of the focal lines of the fan-beam collimators. Four energy windows were employed for\\u000a data acquisition: (a)
Clinical Value of Acute Rest Technetium99m Tetrofosmin Tomographic Myocardial Perfusion Imaging in Patients With Acute Chest Pain and Nondiagnostic Electrocardiograms
Gary V Heller; Stephen A Stowers; Robert C Hendel; Steven D Herman; Edouard Daher; Alan W Ahlberg; Jack M Baron; Carlos F Mendes de Leon; John A Rizzo; Frans J. Th Wackers
Objectives. We sought to evaluate the clinical use and cost-analysis of acute rest technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomographic (SPECT) myocardial perfusion imaging in patients with chest pain and a normal electrocardiogram (ECG).Background. Current approaches used in emergency departments (EDs) for treating patients presenting with chest pain and a nondiagnostic ECG result in poor resource utilization.Methods. Three hundred fifty-seven
Synthesis and evaluation of technetium-99m-labeled bioreductive pharmacophores conjugated with amino acids and peptides for tumor imaging.
Baishya, Rinku; Nayak, Dipak K; Karmakar, Sanmoy; Chattopadhyay, Sankha; Sachdeva, Satbir S; Sarkar, Bharat R; Ganguly, Shantanu; Debnath, Mita C
Development of molecular imaging agents to target tumor has become a major trend in nuclear medicine. With the aim to develop new potential 99mTc-radiopharmaceuticals for targeting tumor, we have synthesized 5-nitroimidazolyl amino acids and RGD-coupled 2-nitroimidazoles. Technetium-99m radiolabeling with high radiochemical purity (>90%) was achieved for all the compounds. The radiolabeled complexes exhibited substantial in vitro stability in saline, serum, and histidine solution (10(-2) m). Cell binding studies in EAC and B16F10 cell lines also revealed rapid and comparatively high cellular internalization. Among all the compounds studied, the binding of 99mTc(CO)3-5 to B16F10 cells was moderately inhibited by the competitive peptide c[RGDfV], suggesting specificity of the radioligand toward ?v?3 receptor. However, no significant displacement of bound radioligand was observed when the binding of the 99mTc-labeled complexes to above cells was challenged with excess competitive peptide. Fluorescent microscopy study provided direct evidence of intracellular localization of 5(6)-carboxyfluorescein-labeled 2-nitroimidazolyl-RGD-peptide in ?v?3-positive B16F10 mouse melanoma cell line. The ligands caused only 8-13% of hemolysis toward rat erythrocytes at concentrations as high as 100 ?m. Imaging and biodistribution studies were performed in Swiss albino mice bearing induced tumor. 99mTc-1 and 99mTc(CO)3-5 demonstrated a very favorable in vivo profile. Selective uptake and retention in tumor with encouraging tumor/muscle and tumor/blood ratio and significant cellular uptake of fluorescence-labeled-2-nitroimidazolyl RGD indicate the great potentiality of the pharmacophore for further evaluation as potential molecular imaging agent in cancer diagnosis. PMID:25243793
Hydrated clearance of gadolinium-DTPA as a measurement of glomerular filtration rate
Peter L Choyke; Howard A Austin; Joseph A Frank; Mary E Girton; Richard L Diggs; Andrew J Dwyer; LaGrieta Miller; Robert Nussenblatt; Henry McFarland; Theodore Simon
Hydrated clearance of gadolinium-DTPA as a measurement of glomerular filtration rate. Technetium (99mTc)-diethylene triamine pentaacetic acid (DTPA) hydrated clearance studies are accurate for determining GFR but require special facilities for handling and measuring samples. We investigated the potential of a non-radioactive paramagnetic analog, Gadolinium (Gd)-diethylene triamine pentaacetic acid (DTPA), an approved NMR contrast agent, as a glomerular filtration marker. Instead
Personalized predictive lung dosimetry by technetium-99m macroaggregated albumin SPECT/CT for yttrium-90 radioembolization
Background For yttrium-90 (90Y) radioembolization, the common practice of assuming a standard 1,000-g lung mass for predictive dosimetry is fundamentally incongruent with the modern philosophy of personalized medicine. We recently developed a technique of personalized predictive lung dosimetry using technetium-99m (99mTc) macroaggregated albumin (MAA) single photon emission computed tomography with integrated CT (SPECT/CT) of the lung as part of our routine dosimetric protocol for 90Y radioembolization. Its rationales are the technical superiority of SPECT/CT over planar scintigraphy, ease and convenience of lung auto-segmentation CT densitovolumetry, and dosimetric advantage of patient-specific lung parenchyma masses. Methods This is a retrospective study of our pulmonary clinical outcomes and comparison of lung dosimetric accuracy and precision by 99mTc MAA SPECT/CT versus conventional planar methodology. 90Y resin microspheres (SIR-Spheres) were used for radioembolization. Diagnostic CT densitovolumetry was used as a reference for lung parenchyma mass. Pulmonary outcomes were based on follow-up diagnostic CT chest or X-ray. Results Thirty patients were analyzed. The mean lung parenchyma mass of our Southeast Asian cohort was 822?▒?103Āg standard deviation (95% confidence interval 785 to 859Āg). Patient-specific lung parenchyma mass estimation by CT densitovolumetry on 99mTc MAA SPECT/CT is accurate (bias ?21.7Āg) and moderately precise (95% limits of agreement ?194.6 to +151.2Āg). Lung mean radiation absorbed doses calculated by 99mTc MAA SPECT/CT and planar methodology are both accurate (bias <0.5ĀGy), but 99mTc MAA SPECT/CT offers better precision over planar methodology (95% limits of agreement ?1.76 to +2.40ĀGy versus ?3.48 to +3.31ĀGy, respectively). None developed radiomicrosphere pneumonitis when treated up to a lung mean radiation absorbed dose of 18ĀGy at a median follow-up of 4.4Āmonths. Conclusions Personalized predictive lung dosimetry by 99mTc MAA SPECT/CT is clinically feasible, safe, and more precise than conventional planar methodology for 90Y radioembolization radiation planning. PMID:25024931
Scintigraphic assessment of bowel involvement and disease activity in Crohn's disease using technetium 99m-hexamethyl propylene amine oxine as leukocyte label
Schoelmerich, J.S.; Schmidt, E.; Schuemichen, C.B.; Billmann, P.; Schmidt, H.; Gerok, W.
Using a novel labeling technique with technetium 99m-hexamethyl propylene amine oxine, we studied 29 patients with known or suspected Crohn's disease. Technetium 99m-hexamethyl propylene amine oxine leukocyte scanning (99mTc scan) was prospectively compared with the results of independently performed radiologic, endoscopic, and histologic examinations, and with findings at surgery, to assess the clinical usefulness of this technique to localize inflammatory lesions. In addition, uptake of technetium 99m-hexamethyl propylene amine oxine in the bowel was graded by comparing it with the uptake in liver and bone marrow and correlating this with established parameters of disease activity. The viability of homologous labeled leukocytes was greater than 95%. Less than 5% of lymphocytes were found in the final preparation. It was found that 45% +/- 12% of the label was bound to granulocytes, and 98% of the unbound label was washed off before reinjection. The results of 99mTc scan revealed a good correlation with those of barium enema (r = 0.880, p less than 0.001), of endoscopy/surgery (r = 0.983, p less than 0.001), and of all combined reference methods (r = 0.981, p less than 0.001). Activity as determined by 99mTc scan was weakly correlated with the results of Crohn's disease activity index (r = 0.559, p less than 0.01), van Hees index (r = 0.606, p less than 0.01), and erythrocyte sedimentation rate (r = 0.456, p less than 0.05) in 24 patients with proven Crohn's disease. The correlation was improved when the 99mTc scan was compared with a combination of these activity parameters and C-reactive protein (r = 0.781, p less than 0.001). Extraintestinal manifestations (joints) and complications (cholecystitis) were also identified correctly by the 99mTc scan.
Post-traumatic avascular necrosis of the femoral head predicted by preoperative technetium-99m antimony-colloid scan: an experimental and clinical study. [Rabbits; patients
Turner, J.H.
Technetium-99m antimony colloid was used to visualize the bone marrow of the head of the femur within twenty-four hours after interruption of the blood supply by subcapital osteotomy and section of the ligamentum teres in thirteen rabbits and within twenty-four hours after a subcapital fracture in thirty patients. Of the rabbits, all showed loss of marrow radioactivity over the affected femoral head. Bone-imaging with technetium-99m methylene diphosphonate, in contrast, failed to demonstrate any abnormality in the avascular head of the femur for as long as forty-eight hours after osteotomy. This difference between the marrow scan and the bone scan was attributed to earlier loss of function in the marrow cells than in the osteocytes. The thirty patients who had a preoperative scan within twenty-four hours after sustaining a subcapital fracture were treated by internal fixation with a Richards screw and plate and were followed for as long as two years, or until the patient died or radiographs showed evidence of avascular necrosis. The preoperative technetium-99m antimony-colloid activity in the head of the fractured femur was normal in sixteen patients and absent in fourteen; two of the fourteen had no activity in either hip, which precluded assessment of the fractured hip in these patients. In fifteen of the sixteen hips, preservation of the uptake in the marrow of the head of the fractured femur preoperatively predicted normal healing. Late segmental collapse developed in the remaining hip. In eleven of the twelve patients who had loss of marrow activity in the femoral head preoperatively, avascular necrosis developed within two years.
Synthesis and characterization of rhenium and technetium-99m tricarbonyl complexes bearing the 4-[3-bromophenyl]quinazoline moiety as a biomarker for EGFR-TK imaging
Athanasia Bourkoula; Maria Paravatou-Petsotas; Apostolos Papadopoulos; Isabel Santos; Hans-Jurgen Pietzsch; Evangelia Livaniou; Maria Pelecanou; Minas Papadopoulos; Ioannis Pirmettis
Aiming at the development of technetium-99m (99mTc) complexes for early detection and staging of EGFR positive tumors, the tyrosine kinase inhibitor 6-amino-4-[(3-bromophenyl)amino]quinazoline was derivatized with pyridine-2-carboxaldehyde to generate the imine 6-(pyridine-2-methylimine)-4-[(3-bromophenyl)amino]quinazoline suitable for reacting with the fac-[99mTc(CO)3]+ core as an N,N bidentate ligand.The labelling was performed in high yield (>90%) by ligand exchange reaction using fac-[99mTc(OH2)3(CO)3]+ as precursor. The 99mTc
[Scintigraphic imaging of knee synovitis in osteoarthritis after intra-articular injection of technetium-99m pertechnetate in the unilateral knee].
Chatzopoulos, Dimitrios; Markou, Pavlos; Iakovou, Ioannis
A case of left knee synovitis scintigraphic imaging is presented in a 66-year-old patient with bilateral knee osteoarthritis and a right knee Baker's cyst, who had undergone a 74 MBq (99m)Tc-pertechnetate intra-articular injection in the right knee. The findings in this case were compared with the intravenously injected methylene disphosphonate technetium-99m ((99m)Tc-MDP) scintigraphic findings and could be interpreted as the result of (99m)Tc-pertechenate through blood communication from the right to the left knee. This case implies that (99m)Tc-pertechnetate may be useful in imaging the synovitis in multiple arthroses even up to 60 min after its administration, instead of the 5 min imaging after the injection of (99m)Tc-MDP. PMID:16617402
[A comparison on radiochemical behavior and biological property of antisense oligonucleotide labeled with technetium-99m by two methods: NHS-MAG3 versus SHNHP].
Li, Yunchun; Tan, Tianzhi; Zheng, Jianguo; Zhang, Chun
This study was undertaken to explore and compare the radiochemical behavior and biological property of antisense oligonucleotide (ASON) labeled with Technetium-99m using two methods: N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycline (NHS-MAG3) versus hydrazino nicotinamide derivative (SHNH). After SHNH and NHS-MAG3 were synthesized, ASON was labeled with Technetium-99m using SHNH and NHS-MAG3 as a bifunctional chelator, separately. The stability in vivo and in vitro, the combination with plasma albumen of rabbit, the biodistribution in BALB/ C mice and the HT29 cellular uptake were compared between labeled compound 99mTc-SHNH-ASON, using SHNH as a bifunctional complex reagent, and 99mTc-MAG3-ASON, using NHS-MAG3 as a bifunctional chelator. The results revealed that the labeling rate and the stability of 99mTc-MAG3-ASON were evidently higher than that of 99mTc-SHNH-ASON (P < 0.05), the combination rate of 99mTc-MAG3-ASON with plasma albumen was markedly lower than that of 99mTc-SHNH-ASON (P < 0.05); the biodistribution of 99mTc-MAG3-ASON was markedly lower than that of 99mTc-SHNH-ASON in blood, heart, stomach and intestines (P < 0.05), slightly lower than that of 99mTc-SHNH-ASON in liver and spleen (P > 0.05), and markedly higher than that of 99mTc-SHNH-ASON in kidney (P < 0.05); the HT29 cellular uptake rates of 99mTc-MAG3-ASON was markedly higher than that of 99mTc-SHNH-ASON (P < 0.05). Therefore, the radiochemical behavior and biological property of 99mTc-MAG3-ASON labeled using NHS-MAG3 is better than that of 99mTc-SHNH-ASON labeled using SHNH. PMID:18788302
Technetium-99m-human polyclonal IgG radiolabeled via the hydrazino nicotinamide derivative for imaging focal sites of infection in rats
Abrams, M.J.; Juweid, M.; tenKate, C.I.; Schwartz, D.A.; Hauser, M.M.; Gaul, F.E.; Fuccello, A.J.; Rubin, R.H.; Strauss, H.W.; Fischman, A.J. (Massachusetts General Hospital, Boston (USA))
The biologic behavior of human polyclonal immunoglobulin (IgG) radiolabeled with technetium-99m ({sup 99m}Tc) by a novel method, via a nicotinyl hydrazine derivative, was evaluated in rats. Technetium-99m- and indium-111-IgG were co-administered to normal rats and biodistribution was determined at 2, 6, and 16 hr. The inflammation imaging properties of the two reagents were compared in rats with deep-thigh infection due to Escherichia coli. Blood clearance of both antibody preparations was well described by a bi-exponential function: ({sup 99m}Tc-IgG: t1/2 = 3.82 +/- 0.89 and 57.52 +/- 1.70 hr. {sup 111}In-IgG: 3.93 +/- 0.117 and 40.71 +/- 1.26 hr). Biodistributions in the solid organs were similar, however, small but statistically significant differences were detected: {sup 99m}Tc-IgG greater than {sup 111}In-IgG in lung, liver, and spleen; {sup 99m}Tc-IgG less than {sup 111}In-IgG in kidney and skeletal muscle (p less than 0.01). At all three imaging times, target-to-background ratio and percent residual activity for the two compounds were remarkably similar. These studies establish that human polyclonal IgG labeled with {sup 99m}Tc via a nicotinyl hydrazine modified intermediate is equivalent to {sup 111}In-IgG for imaging focal sites of infection in experimental animals.
Relationship of end-expiratory pressure, lung volume, and /sup 99m/Tc-DTPA clearance
Cooper, J.A.; van der Zee, H.; Line, B.R.; Malik, A.B.
We investigated the dose-response effect of positive end-expiratory pressure (PEEP) and increased lung volume on the pulmonary clearance rate of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Clearance of lung radioactivity was expressed as percent decrease per minute. Base-line clearance was measured while anesthetized sheep (n = 20) were ventilated with 0 cmH/sub 2/O end-expiratory pressure. Clearance was remeasured during ventilation at 2.5, 5, 10, 15, or 20 cmH/sub 2/O PEEP. Further studies showed stepwise increases in functional residual capacity (FRC) (P less than 0.05) measured at 0, 2.5, 5, 10, 15, and 20 cmH/sub 2/O PEEP. At 2.5 cmH/sub 2/O PEEP, the clearance rate was not different from that at base line (P less than 0.05), although FRC was increased from base line. Clearance rate increased progressively with increasing PEEP at 5, 10, and 15 cmH/sub 2/O (P less than 0.05). Between 15 and 20 cmH/sub 2/O PEEP, clearance rate was again unchanged, despite an increase in FRC. The pulmonary clearance of aerosolized /sup 99m/Tc-DTPA shows a sigmoidal response to increasing FRC and PEEP, having both threshold and maximal effects. This relationship is most consistent with the hypothesis that alveolar epithelial permeability is increased by lung inflation.
Comparison of four technetium-99m radiopharmaceuticals for detection and localization of gastrointestinal bleeding in a sheep model
Owunwanne, A.; Al-Wafai, I.; Vallgren, S.; Sadek, S.; Abdel-Dayem, H.M.; Yacoub, T.
Four Tc-99 radiopharmaceuticals, Tc-99m sulphur colloid, Tc-99m red blood cells (RBCs), Tc-99m mercaptoacetyltriglycine (MAG3), and Tc-99m DTPA, were studied in an experimental animal model for detection and localization of gastrointestinal (GI) bleeding site in both the upper and lower abdomen. With Tc-99m sulphur colloid and Tc-99m RBCs, it was possible to detect and localize the GI bleeding site in the lower abdomen. With Tc-99m MAG3, it was possible to visualize the bleeding site in both the upper and lower abdomen. However, Tc-99m MAG3 is partially excreted by the liver into the bile, hence it will be difficult to use Tc-99m MAG3 to localize the GI bleeding site in the lower abdomen. With Tc-99m DTPA, it was possible to detect and localize the GI bleeding site simultaneously in both upper and lower abdomen. The overall background radioactivity was reduced considerably by diuresis with frusemide and catheterization of the urinary bladder.
Aerosol characteristics of 99mTc-pentetic acid (DTPA) and synthetic surfactant (Exosurf).
Coleman, R E; MacIntyre, N; Snyder, G; Pattishall, E; Zaccardelli, D
This study evaluated the feasibility of using 99mTc-pentetic acid (DTPA) as a radioactive tracer for aerosolized synthetic surfactant (DPPC, cetyl alcohol, tyloxapol). The 99mTc-DTPA was admixed with surfactant and aerosolized using a nebulizer system interfaced to a ventilator with a cascade impactor attached to the endotracheal tube. Particle size distribution for DPPC, cetyl alcohol, and 99mTc-DTPA were almost identical during the 0- to 15-, 15- to 30-, and 0- to 30-min collection periods. Tyloxapol exhibited a unique distribution pattern with increased deposition in large (> 10 microns) and small (0.65 to 1.1 microns) particles. The mass median aerodynamic diameter for all aerosolized components was in the respirable range of 2.1 to 2.5 microns. A mixture of 99mTc-DTPA with synthetic surfactant appears to be a reasonable method to evaluate surfactant deposition. PMID:8205874
p-Tertbutylcalix[4]arene nanoemulsion: preparation, characterization and comparative evaluation of its decontamination efficacy against Technetium-99m, Iodine-131 and Thallium-201.
Rana, Sudha; Sharma, Navneet; Ojha, Himanshu; Shivkumar, Hosakote Gurumalappa; Sultana, Sarwat; Sharma, Rakesh Kumar
This study aimed to develop p-tertbutylcalix[4]arene o/w nanoemulsion for decontamination of radioisotopes from skin. Formulation was characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), multi-photon confocal microscopy techniques and in vitro dissolution studies. In vivo evaluation of nano-emulsion was done using nuclear medicine technique. Stability studies and dermal toxicity studies were also carried out. Comparative decontamination efficacy (DE) studies were performed on synthetic human tissue equivalent material and Sprague Dawley rat against three commonly used medical radioisotopes, i.e., Technetium-99m ((99m)Tc), Iodine-131 ((131)I) and Thallium-201 ((201)Tl). Decontamination was performed using cotton swabs soaked in nanoemulsion at different time intervals of contaminants exposure. Whole body imaging and static counts were recorded using gamma camera before and after each decontamination attempt data was analyzed using one way analysis of variance (ANOVA) and found to be statistically significant (p<0.05). DE of the nanoemulsion loaded with p-tertbutylcalix[4]arene was observed to be 88▒5%, 90▒3% and 89▒3% for (99m)Tc, (131)I and (201)Tl respectively. Dermal toxicity studies revealed no significant differences between treated and control animals. Skin histopathology slides with and without API (Active pharmaceutical ingredients) also found to be comparable. p-Tertbutylcalix[4]arene loaded nanoemulsion shows great promise for skin decontamination against broad ranges of radiological contaminants besides being stable and safe. PMID:24632037
Differences in the intracellular processing of the radiolabel following the uptake of iodine-125- and technetium-99m-neogalactosyl albumin by the isolated perfused rat liver
Gore, S.; Morris, A.I.; Gilmore, I.T.; Maltby, P.J.; Thornback, J.R.; Billington, D. (Royal Liverpool Hospital (England))
Neogalactosyl albumin (NGA) is a synthetic ligand to the asialoglycoprotein receptor (hepatic binding protein), which has been proposed as a useful receptor binding radiopharmaceutical for the noninvasive assessment of liver function. We have compared the uptake and intracellular processing of iodine-125- (125I) and technetium-99m- ({sup 99m}Tc) NGA following its administration as a 1-min pulse (147 pmol) to the isolated perfused rat liver. Approximately 40% of a pulse of either {sup 125}I- or {sup 99m}Tc-NGA were taken up first pass by the liver. Of the {sup 125}I taken up by the liver, 82% was released after 15-20 min at the sinusoidal pole of the hepatocyte, predominantly as small molecular weight metabolites. A further 8% of the {sup 125}I-associated radioactivity was secreted as intact NGA into bile by the non-lysosomal (direct) pathway while 6% remained in the liver 1 hr after the pulse. In contrast, of the {sup 99m}Tc taken up by the liver, only 4% reappeared in the perfusate while 40% was secreted into bile by the lysosomal (indirect) pathway and 55% remained in the liver 1 hr after the pulse. Since labeled metabolites of {sup 99m}Tc-NGA do not appear in plasma, this permits kinetic modeling with {sup 99m}Tc-NGA without correction for labeled metabolites. Thus, {sup 99m}Tc-NGA is an excellent candidate as a receptor-binding radiopharmaceutical.
Assessment of acute myocardial necrosis after cardiopulmonary resuscitation and cardioversion by means of combined thallium-201/technetium-99m pyrophosphate tomography.
Krause, T; Hohnloser, S H; Kasper, W; Sch³michen, C; Reinhardt, M; Moser, E
Diagnosis of acute myocardial necrosis by means of conventional electrocardiographic criteria or the release of cardiac enzymes is often difficult or even impossible in patients with out-of-hospital cardiac arrest due to ventricular fibrillation with subsequent cardiopulmonary resuscitation including several DC countershocks. Simultaneous thallium-201/technetium-99m pyrophosphate (PYP) tomography was prospectively applied to 57 patients without typical clinical or electrocardiographic signs of acute myocardial infarction within 48 h after successful resuscitation from out-of-hospital cardiac arrest. Scintigraphic evidence of acute necrosis was present in 23/57 patients (40%). Increased 99mTc-PYP uptake in the pericardial tissue was found in 24 patients (42%). Maximal creatine kinase (CK) concentration was increased in 50/57 patients (88%). CK-MB activity averaged 68+/-52 U/l in patients with positive and 17+/-13 U/l in patients with negative tomograms (P<0.0005), demonstrating the validity of 201Tl/99mTc-PYP tomography. It may be concluded that simultaneous 201Tl/99mTc-PYP tomography is a valuable tool for evaluation of myocardial necrosis after cardiopulmonary resuscitation including DC countershock. Acute myocardial necrosis, as indicated by scintigraphy, represents a potential trigger for the occurrence of ventricular fibrillation. Therefore, 201Tl/99mTc-PYP tomography can be recommended in order to guide further diagnostic and therapeutic interventions in patients after cardiopulmonary resuscitation in whom the underlying cause of the occurrence of ventricular fibrillation is obscure. PMID:8575479
Clinical significance of reverse redistribution on technetium-99m tetrofosmin single-photon emission computed tomography: an 18-month follow-up study
Swinkels, B.M.; Hooghoudt, T.E.H.; Schoenmakers, E.A.J.M.; Zinder, C.G.; de Boo, T.M.; Verheugt, F.W.A.
Background The clinical and prognostic significance of reverse redistribution on technetium-99m (99mTc) single-photon emission computed tomography (SPECT) is unclear. Objectives To determine outcomes of chest pain patients showing reverse redistribution after 99mTc tetrofosmin SPECT versus SPECT showing no reverse redistribution. Methods Patient outcomes (death, nonfatal myocardial infarction, coronary artery bypass grafting and percutaneous transluminal coronary angioplasty) within 18 months after 99mTc tetrofosmin SPECT were determined in two populations of ambulatory patients, most of whom had been evaluated because of chest pain: a population of 57 patients whose SPECT images showed reverse redistribution without reversible or fixed defects, versus a control population of 98 patients whose SPECT images were normal (no reverse redistribution, no reversible defects, no fixed defects). Results Stepwise logistic regression analysis showed that the population of patients with reverse redistribution did not have a worse 18-month outcome in comparison with the control population of patients without reverse redistribution (3.5% versus 9.2%, respectively; p=0.15 corrected for age and gender). Conclusion Reverse redistribution on 99mTc tetrofosmin SPECT does not appear to be an unfavourable prognostic factor in ambulatory chest pain patients. PMID:25696192
Indium-111-leukocyte/technetium-99m-MDP bone and magnetic resonance imaging: Difficulty of diagnosing osteomyelitis in patients with neuropathic osteoarthropathy
Seabold, J.E.; Flickinger, F.W.; Kao, S.C.; Gleason, T.J.; Kahn, D.; Nepola, J.V.; Marsh, J.L. (Univ. of Iowa College of Medicine, Iowa City (USA))
Fourteen patients (16 sites) with clinical and/or radiographic evidence of neuropathic osteoarthropathy (Charcot joints) were evaluated with combined indium-111-leukocyte ({sup 111}In-WBC) and technetium-99m-methylene diphosphonate ({sup 99m}Tc-MDP) bone imaging for suspected osteomyelitis. Magnetic resonance (MR) images were obtained in seven patients. Using a positive bone culture as the criterion for the presence of osteomyelitis, there were four true-positive studies, six true-negative sites, and one false-negative {sup 111}In-WBC study. Five of 16 sites (31%) had false-positive {sup 111}In-WBC uptake at noninfected sites. There were four true-positive and three false-positive MR studies. All false-positives showed at least moderately abnormal findings by both techniques at sites of rapidly progressing osteoarthropathy of recent onset. In this preliminary study, both techniques appear to be sensitive for detection of osteomyelitis, and a negative study makes osteomyelitis unlikely. However, the findings of {sup 111}In-WBC/{sup 99m}Tc-MDP and MR images at sites of rapidly progressing, noninfected neuropathic osteoarthropathy may be indistinguishable from those of osteomyelitis.
Anacardium occidentale bark lectin: purification, immobilization as an affinity model and influence in the uptake of technetium-99M by rat adipocytes.
Maciel, Maria InĻs Sucupira; de Mendonńa Cavalcanti, Maria do Socorro; NapoleŃo, Thiago Henrique; Paiva, PatrĒcia Maria Guedes; de Almeida Catanho, Maria Teresa Jansem; Coelho, Luana Cassandra Breitenbach Barroso
Lectins, proteins that recognize carbohydrates, have been immobilized on inert supports and used in the screening or purification of glycoproteins. Anacardium occidentale bark infusion has been used as a hypoglycemic agent in Brazil. The toxicity of natural products may be evaluated determining their capability to alter the biodistribution of technetium-99M ((99m)Tc). This work reports the isolation and characterization of a lectin from A. occidentale bark (AnocBL), its evaluation as an affinity support for glycoprotein isolation and lectin effect on the uptake of (99m)Tc by rat adipocytes. AnocBL was isolated from 80 % ammonium sulphate supernatant by affinity chromatography on fetuin-agarose. SDS-PAGE showed a single protein band of 47 kDa. The monossacharide L-arabinose and the glycoproteins fetuin, asialofetuin, ovomucoid, casein, thyroglobulin, peroxidase, fetal bovine serum and IgG inhibited the activity. The lectin activity was stable until 70 ░C and at a pH range of 3.0-7.5. AnocBL-Sepharose column bound fetuin indicating that the lectin matrix may be used to obtain glycoconjugates of biotechnological interest. In vitro assay revealed that glucose and insulin increase (99m)Tc uptake by rat adipocytes. AnocBL decreases (99m)Tc uptake, and this effect was not detected in the presence of glucose. Fetuin inhibited AnocBL effect in all insulin concentrations. PMID:22798188
Comparative study of rest technetium-99m sestamibi SPET and low-dose dobutamine stress echocardiography for the early assessment of myocardial viability after acute myocardial infarction: importance of the severity of the infarct-related stenosis
Marc J. Claeys; Frank E. Rademakers; Chris J. Vrints; Bruno Krug; Johan M. Bosmans; Viviane Conraads; Leo L. Bossaert; Jo P. Snoeck; Pierre P. Blockx
Rest technetium-99m sestamibi single-photon emission tomography (SPET) has been shown to under-estimate viability in some patients with chronic ischaemic myocardial dysfunction. The present study was designed to appraise the value of99mTc-sestamibi as a viability tracer in patients with a recent myocardial infarction and to determine factors that might influence its accuracy in assessing infarct size. Therefore, rest99mTc-sestamibi SPET, low-dose dobutamines
Combined assessment of myocardial perfusion and left ventricular function with exercise technetium-99m sestamibi gated single-photon emission computed tomography can differentiate between ischemic and nonischemic dilated cardiomyopathy.
Danias, P G; Ahlberg, A W; Clark, B A; Messineo, F; Levine, M G; McGill, C C; Mann, A; Clive, J; Dougherty, J E; Waters, D D; Heller, G V
The purpose of this study was to determine whether exercise technetium-99m sestamibi gated single-photon emission computed tomography (SPECT) accurately distinguishes between patients with ischemic cardiomyopathy and patients with nonischemic left ventricular systolic dysfunction. Noninvasive tests have previously failed to accurately separate patients with ischemic cardiomyopathy from those with nonischemic cardiomyopathy. Technetium-99m gated SPECT imaging offers advantages that have the potential to overcome the limitations of previous studies. Thirty-seven adults with a left ventricular ejection fraction < or = 35%, including 24 patients with nonischemic cardiomyopathy and 13 patients with ischemic cardiomyopathy, were prospectively evaluated using symptom-limited metabolic exercise treadmill testing with technetium-99m sestamibi gated SPECT imaging. Interpretation of myocardial perfusion and regional wall motion was performed, using a 17-segment model. Summed stress, rest, and reversibility perfusion defect scores were determined, and the variance of segmental wall motion scores was computed. Summed stress, rest, and reversibility perfusion defect scores were significantly lower in nonischemic cardiomyopathy patients, compared with those with ischemic cardiomyopathy (summed stress defect score: 6.9 +/- 3.8 vs 32.9 +/- 7.7, respectively, p <0.001). Variability in segmental wall motion was also significantly lower in patients with nonischemic cardiomyopathy compared with those with ischemic cardiomyopathy (variance: 0.3 +/- 0.3 vs 1.2 +/- 0.8, respectively, p <0.001). Thus, assessment of myocardial perfusion and regional ventricular function with exercise technetium-99m sestamibi gated SPECT imaging can reliably distinguish between patients with ischemic cardiomyopathy and patients with nonischemic dilated cardiomyopathy. PMID:9832104
Abnormal Regional Cerebral Blood Flow found by Technetium99m Ethyl Cysteinate Dimer Brain Single Photon Emission Computed Tomography in Systemic Lupus Erythematosus Patients with Normal Brain MRI Findings
J. J.-H. Chen; R.-F. Yen; A. Kao; C.-C. Lin; C.-C. Lee
:ĀĀ In this study, technetium-99m ethyl cysteinate dimer (99mTc ECD) brain single photon emission computed tomography (SPECT) was used to detect regional cerebral blood flow (rCBF) of\\u000a the brain in SLE patients with normal brain magnetic resonance imaging (MRI) findings. Twenty female SLE patients were enrolled\\u000a in this study, divided into two groups. Group 1 consisted of 10 patients with
Change in Renal Function as Measured by Technetium99m MAG-3 Scintigraphy and Biochemical Endpoints Following Abdominal Chemoradiation for Gastrointestinal Malignancies
May, Kilian Salerno; Chandrasekhar, Rameela; Malhotra, Harish K.; Russo, Richard C.; Flaherty, Leayn; Wilding, Gregory E.; Khushalani, Nikhil I.; Yang, Gary Y.
Background: Information on differential renal function following abdominal chemoradiation (CRT) as measured by renal scintigraphy (RS) is limited. This study was conducted to evaluate the association between renal function, as measured by biochemical endpoints and scintigraphy, and dose volume parameters in patients following abdominal CRT in the treatment of gastrointestinal malignancies. Methods: Patients who received abdominal RT with concurrent chemotherapy between 2002 and 2009 were identified to study the association of renal functional imaging with change in renal function following abdominal CRT. Technetium99m MAG-3 scintigraphy and laboratory data were obtained prior to CRT and after CRT in 6-month intervals. Factors assessed included age, gender, hypertension, diabetes, and dose volume parameters. Renal function was assessed by serum creatinine, creatinine clearance (CrCl) calculated by the Cockcroft-Gault formula, and renal perfusion measured using scintigraphy. Endpoints analyzed include relative renal function, biochemical endpoints, and dose volume parameters. Normal tissue complication probability (NTCP) for the primarily irradiated kidney (PK) was calculated using a tolerance dose for 5% probability of complications at 5 years (TD 5/5) of 23 Gy and ?/? ratio = 2.5. The PK was defined as the kidney that received the greater mean kidney dose. Results: Of 136 patients evaluated, median age was 64 years. The majority of primary disease sites were pancreas and periampullary tumors (75.7%). Median follow up was 9.61 months. Median radiation dose was 50.4 Gy. All patients received concurrent chemotherapy, most with 5-fluorouracil-, capecitabine-, or gemcitabine-containing regimens, and had a baseline RS performed prior to CRT. Significant reductions in relative renal function of the PK and global renal function were seen following CRT. Changes in split renal function, creatinine, and CrCl are shown in the table below. Pre-CRT (n=136) 6¢12 months post CRT (n=25) >12 months post CRT (n=8) P value Mean RS of PK (%) 49.75 (5.30) 47.74 (6.48) 41.28 (7.38) 0.0184 RS Ratio (PK/non PK) 1.01 (0.22) 0.94 (0.25) 0.73 (0.23) 0.0606 Creatinine (mg/dl) 0.87 (0.26) 0.94 (0.23) 1.05 (0.09) *<0.0001 CrCl (ml/min) 90.67 (33.43) 82.23 (30.97) 74.54 (23.00) *<0.0001 * P values obtained using log-transformed values. Univariate analysis did not show age, gender, hypertension, diabetes, or pre CRT CrCl, to be associated with decrease in split perfusion of the PK following CRT. Percent volumes of the PK receiving ? 25 Gy (V25) and 40 Gy (V40) were significantly associated with ?5% decrease in relative renal function of the PK in patients who had at least one post CRT renogram (P = .0387 and P = .0438 respectively). The difference in NTCP for the PK was significantly different between patients with <5% change in split renal function on RS versus those with ? 5% decrease (11.4 % vs. 24.2%, P = .0097). Conclusions: Decline in split renal function using Technetium99m MAG-3 scintigraphy correlates with decrease in CrCl and radiation dose-volume parameters following abdominal radiation with concurrent chemotherapy. Change in split perfusion can be detected as early as 6 months post CRT. Scintigraphy may provide early determination and quantification of subclinical renal injury prior to clinical evidence of nephropathy.
Detection of dose response in chronic doxorubicin-mediated cell death with cardiac technetium 99m annexin V single-photon emission computed tomography.
Gabrielson, Kathleen L; Mok, Greta S P; Nimmagadda, Srihdar; Bedja, Djahida; Pin, Scott; Tsao, Allison; Wang, Yuchuan; Sooryakumar, Dhrtti; Yu, S Jianhua; Pomper, Martin G; Tsui, Benjamin M W
The aim of this study was to evaluate whether technetium 99m hydrazinonicotinamide (99mTc-HYNIC)-annexin V single-photon emission computed tomography (SPECT) would detect dose-dependent doxorubicin (DOX)-mediated cell death in the heart compared with functional echocardiography. Adult female Sprague-Dawley rats were treated with DOX (cumulative dose of 15 or 7.5 mg/kg) or saline (n = 7) and monitored by echocardiography. Rats were injected with 7 to 8 mCi 99mTc-HYNIC-annexin V and imaged 1 hour postinjection using a small animal dual-head SPECT/computed tomography (CT) system with multipinhole technology. Two regions of interest were drawn in the myocardium and soft tissue regions to calculate the cardiac uptake ratio (CUR) of reconstructed images. Myocardium and blood were harvested for radioactivity measurements or TUNEL assay. Biodistribution of 99mTc-HYNIC-annexin V uptake, CUR from SPECT/CT fused cardiac images, and TUNEL of myocardium demonstrated a dose-dependent toxicity response, with the cumulative 15 mg/kg DOX treatment showing the greatest degree of cell death. In contrast, echocardiography detected functional deficits only at the highest DOX dose. In vivo molecular imaging of DOX-induced cardiac toxicity with 99mTc-HYNIC-annexin V detects dose-dependent cell death before ventricular deficits are observed with echocardiography. 99mTc-HYNIC-annexin V SPECT-based molecular imaging may provide an attractive new technique for assessing early changes in myocardial function in patients undergoing DOX therapy. PMID:19123983
Myocardial infarction determined by technetium-99m pyrophosphate single-photon tomography complicating elective coronary artery bypass grafting for angina pectoris
Burns, R.J.; Gladstone, P.J.; Tremblay, P.C.; Feindel, C.M.; Salter, D.R.; Lipton, I.H.; Ogilvie, R.R.; David, T.E.
The incidence of acute myocardial infarction (AMI) complicating coronary artery bypass grafting (CABG) has previously been based on concordance of electrocardiographic, enzymatic and scintigraphic criteria. Technetium-99m pyrophosphate (Tc-PPi) single-photon emission computed tomography now enables detection of AMI with high sensitivity and specificity. Using this technique, perioperative AMI was detected in 12 of 58 patients (21%) undergoing successful elective CABG for stable angina pectoris. Stepwise multivariate logistic regression analysis was performed to compare the predictive value of preoperative (New York Heart Association class, left ventricular ejection fraction and use of beta blockers) and intraoperative (number of grafts constructed, use of internal mammary anastomoses, use of sequential saphenous vein grafts, smallest grafted distal vessel lumen caliber and aortic cross-clamp time) variables. Preoperative New York Association class (p = 0.04) and smallest grafted distal vessel lumen caliber (p = 0.03) were significant multivariate predictors of perioperative AMI. Only 1 perioperative patient with AMI (and 1 pyrophosphate-negative patient) developed new Q waves. Serum creatine kinase-MB was higher in patients with AMI by repeated measures analysis of variance (p = 0.0003). Five AMIs occurred in myocardial segments revascularized using sequential saphenous vein grafts, and 7 in segments perfused by significantly stenosed epicardial vessels with distal lumen diameter and perfusion territory considered too small to warrant CABG. At 6-month follow-up, the mean left ventricular ejection fraction increased from 0.61 to 0.65 in Tc-PPI-negative patients (p = 0.01), but not in perioperative patients with AMI.
Comparison of exercise electrocardiography, technetium-99m sestamibi single photon emission computed tomography, and dobutamine and dipyridamole echocardiography for detection of coronary artery disease in hypertensive women.
Lu, Chunzeng; Lu, Fei; Fragasso, Gabriele; Dabrowski, Pawel; Di Bello, Vitantonio; Chierchia, Sergio L; Gianolli, Luigi; Marzilli, Mario; Balbarini, Alberto
To assess the performance of currently used stress tests for the detection of coronary artery disease (CAD) in a series of female hypertensive patients. We performed exercise electrocardiography (ECG), technetium-99m sestamibi (MIBI) single photon emission computed tomography, dobutamine and dipyridamole echocardiography, and coronary angiography in 76 hypertensive women. Of the 76 study patients, 31 (41%) had significant CAD. The sensitivity of exercise ECG (81%), MIBI scanning (90%), and dobutamine echocardiography (87%) was greater than that of dipyridamole echocardiography (61%). This finding resulted from the lower sensitivity of dipyridamole echocardiography in the detection of single-vessel CAD (47% vs 76%, 88%, and 82% for the other 3 methods). In contrast, the sensitivity of the 4 tests was similar in the detection of multivessel CAD. The specificity of exercise ECG (56%) and MIBI scanning (53%) was less than that of dobutamine (82%, both p <0.01) and dipyridamole (91%, both p <0.001) echocardiography. This finding related to the lower specificity of exercise ECG in patients with either left ventricular hypertrophy or ST-T abnormalities at rest compared to the specificity in patients without these disorders (33% vs 89%, p <0.01). A lower MIBI scan specificity was found only in patients with left ventricular hypertrophy (31% vs 66%, p <0.05). The overall accuracy of dobutamine echocardiography reached 84% compared to exercise ECG (66%, p <0.01), MIBI scan (68%, p <0.05), and dipyridamole echocardiography (79%, p <0.05). In conclusion, dobutamine echocardiography yielded satisfactory diagnostic accuracy for identifying CAD in hypertensive women. Although dipyridamole echocardiography had the greatest specificity, it might be limited in detecting mild CAD. Both exercise ECG and MIBI scanning had fare sensitivity; however, our findings limit the usefulness of these 2 tests in unselected patients. PMID:20403475
Similar effect of revascularization on technetium-99m( )sestamibi and 15-(p-iodophenyl)pentadecanoic acid uptake in myocardial infarction patients.
Bendel, S; Kettunen, R; Hartikainen, J; Remes, J; Vanninen, E; Yang, J; Kuikka, J; Huikuri, H
To study its usefulness as a tracer for assessment of the perfusion and viability of myocardium, 15-(p-iodophenyl)pentadecanoic acid (IPPA) was compared with technetium-99m sestamibi (MIBI). Dual-tracer single-photon emission tomography rest imaging was performed no more than 2 months before and 3 months after coronary artery bypass grafting in 28 patients with previous anterior (n=13) or inferior (n=15) infarction. The size of MIBI and IPPA defects decreased from 14%+/-12% and 13%+/-9% to 10%+/-11% and 9%+/-7%, respectively (P<0.001 for both). The MIBI uptake increased in the infarct zones from 35%+/-11% to 43%+/-8% (P<0.001), and in the peri-infarct zones from 50%+/-11% to 55%+/-10% (P<0.05). The IPPA uptake increased in the infarct zones from 37%+/-11% to 44%+/-13% (P<0.001), and in the peri-infarct zones from 51%+/-11% to 57%+/-12% (P<0.05). In nine patients with improved regional echocardiographic wall motion score after bypass surgery, the pre-operative uptake values of both MIBI and IPPA in the infarct and peri-infarct zones were on average slightly but not significantly higher than in 19 patients with no observed improvement in regional wall motion score. In patients with improved regional wall motion, the MIBI scans and the IPPA scans showed (non-significant) decreases in defect size and increases in infarct and peri-infarct zone uptake after bypass surgery. Similar (in some cases significant) changes were observed in the patients without improvement in wall motion. Thus IPPA and MIBI provided similar information about perfusion and viability in pre- and postoperative evaluation of patients with clinically evident myocardial infarction and with normal global ejection fraction. Regardless of the tracer used, the resolution capability of the dual-tracer method with a rest imaging protocol was not sufficient to differentiate viable from non-viable infarction defects in unselected individual patients with a normal ejection fraction. PMID:10541829
Diagnostic accuracy of contrast echocardiography during adenosine stress for detection of abnormal myocardial perfusion: a prospective comparison with technetium-99 m sestamibi single-photon emission computed tomography.
Abdelmoneim, Sahar S; Bernier, Mathieu; Dhoble, Abhijeet; Moir, Stuart; Hagen, Mary E; Ness, Sue Ann C; Pellikka, Patricia A; Abdel-Kader, Samir S; Mulvagh, Sharon L
Myocardial contrast echocardiography (MCE) utilizes compressible microbubbles behaving similarly to red blood cells. Destruction of microbubbles and observation of the gradual refill into the myocardium are key to evaluating perfusion using real-time MCE. We aimed to assess the feasibility and diagnostic accuracy of qualitative MCE utilizing a 17-segment model for localization of myocardial perfusion abnormalities compared with simultaneous technetium-99 m sestamibi single-photon emission computed tomography (SPECT). From July 2005 through August 2007, 97 patients with known or suspected coronary artery disease underwent simultaneous SPECT and realtime MCE during adenosine stress. Qualitative MCE and tracer uptake were analyzed visually using a 17-segment model in a blinded manner. Diagnostic accuracy and 95% confidence interval (CI) were determined. Myocardial contrast echocardiography was completed in 91 patients (age, mean [SD], 69.3 [10.9] years; body mass index, 30.0 [6.3]; 59 males [65%]). Myocardial contrast echocardiography analysis was feasible in 88 (97%) patients (261 of 264 [99%] territories; 1299 of 1497 [87%] segments). At patient level, MCE sensitivity was 88% (95% CI, 79%-94%); specificity was 85% (77%-90%). For disease detection in individual coronary territories, sensitivity and specificity were 84% (71%-92%) and 79% (72%-84%) for the left anterior descending artery; 62% (38%-80%) and 88% (83%-91%) for the left circumflex artery; and 73% (57%-82%) and 94% (89%-97%) for the right coronary artery. For MCE combined with wall-motion analysis, concordance with SPECT improved from 80% to 86%. Myocardial contrast echocardiography interobserver concordance was 81% (kappa [SE], 0.611 [0.78]). Myocardial contrast echocardiography accuracy was comparable in patients classified in accordance with presence of diabetes mellitus, myocardial infarction, hypertension, or percutaneous coronary intervention. Improved MCE specificity in detecting perfusion defects was seen in patients with no history of coronary bypass graft surgery (P = 0.005). Real-time MCE with a 17-segment model for analysis has good feasibility and accuracy in evaluation of myocardial perfusion during adenosine stress. PMID:20339973
Rhenium(I) and technetium-99m(I) fac-tricarbonyl complexes with 4-(imidazolin-2-yl)-3-thiabutanoic acid derivatives as tridentate ligands: Synthesis and structural characterization
P. Kyprianidou; C. Tsoukalas; G. Patsis; D. Papagiannopoulou; N. Nikoli?; D. Jankovi?; D. Djoki?; C. P. Raptopoulou; M. Pelecanou; M. Papadopoulos; I. Pirmettis
Two rhenium(I) tricarbonyl complexes, with the monoanionic tridentate NSO type ligand, 4-(imidazolin-2-yl)-3-thiabutanoic acid and 4-(N-ethylimidazolin-2-yl)-3-thiabutanoic acid were synthesized and isolated in pure form. Both complexes were characterized by spectroscopic methods and elemental analysis. The solid-state structure of 4-(imidazolin-2-yl)-3-thiabutanoic acid and of both complexes was established by X-ray crystallography. The geometry about the rhenium is octahedral. The analogous technetium-99m complexes were
Effect of inspiratory resistance and PEEP on /sup 99m/Tc-DTPA clearance
O'Brodovich, H.; Coates, G.; Marrin, M.
Experiments were performed to determine the effect of markedly negative pleural pressure (Ppl) or positive end-expiratory pressure (PEEP) on the pulmonary clearance (k) of technetium-99m-labeled diethylenetriaminepentaacetic acid (/sup 99m/Tc-DTPA). A submicronic aerosol containing /sup 99m/Tc-DTPA was insufflated into the lungs of anesthetized intubated sheep. In six experiments k was 0.44 +/- 0.46% (SD)/min during the initial 30 min and was unchanged during the subsequent 30-min interval (k = 0.21 +/- 12%/min) when there was markedly increased inspiratory resistance. A 3-mm-diam orifice in the inspiratory tubing created the resistance. It resulted on average in a 13-cmH2O decrease in inspiratory Ppl. In eight additional experiments sheep were exposed to 2, 10, and 15 cmH2O PEEP (20 min at each level). During 2 cmH2O PEEP k = 0.47 +/- 0.15%/min, and clearance increased slightly at 10 cmH2O PEEP (0.76 +/- 0.28%/min, P less than 0.01). When PEEP was increased to 15 cmH2O a marked increase in clearance occurred (k = 1.95 +/- 1.08%/min, P less than 0.001). The experiments demonstrate that markedly negative inspiratory pressures do not accelerate the clearance of /sup 99m/Tc-DTPA from normal lungs. The effect of PEEP on k is nonlinear, with large effects being seen only with very large increases in PEEP.
Measurement of pulmonary epithelial permeability with /sup 99m/Tc-DTPA aerosol
Coates, G.; O'Brodovich, H.
The rate at which inhaled aerosol of /sup 99m/Tc-diethylenetriamine pentaacetate (DTPA) leaves the lung by diffusion into the vascular space can be measured with a gamma camera or simple probe. In normal humans, /sup 99m/Tc-DTPA clears from the lung with a half time of about 80 minutes. Many acute and chronic conditions that alter the integrity of the pulmonary epithelium cause an increased clearance rate. Thus cigarette smoking, alveolitis from a variety of causes, adult respiratory distress syndrome (ARDS), and hyaline membrane disease (HMD) in the infant have all been shown to be associated with rapid pulmonary clearance of /sup 99m/Tc-DTPA. Rapid clearance is also promoted by increased lung volume and decreased surfactant activity. Although the mechanism of increased clearance in pathological states is not known, the /sup 99m/Tc-DTPA lung-clearance technique has great potential clinically, particularly in patients at risk from ARDS and HMD and in the diagnosis and follow-up of alveolitis. 58 references.
[Noninvasive diagnosis of cardiac involvement by technetium-99m-pyrophosphate (Tc-99m PYP) myocardial scintigraphy in 2 cases of familial amyloid polyneuropathy and 1 case of secondary amyloidosis].
Takezaki, M; Ishida, Y; Morozumi, T; Tani, A; Sato, H; Hori, M; Kitabatake, A; Kamada, T; Kimura, K; Kozuka, T
To validate the significance of technetium-99m-pyrophosphate (Tc-99m PYP) myocardial scintigraphy in diagnosing cardiac amyloidosis, 2 patients with familial amyloid polyneuropathy (FAP) and 1 patient with amyloidosis secondary to chronic rheumatic arthritis were studied. All three patients had echocardiographic abnormalities, which were increased wall thickness of the interventricular septum and the left ventricular posterior wall, and granular sparkling appearance in the septum. In 2 patients with FAP, abnormal myocardial uptake of Tc-99m PYP was diffusely detected in Tc-99m PYP SPECT. In the remaining 1 patient with secondary amyloidosis, however, Tc-99m PYP SPECT showed no abnormality, although we had confirmed the presence of myocardial amyloid deposits (type AA amyloid protein) with high amount in the histological examination. Thus, these results indicate that Tc-99m PYP scintigraphy may have a limitation in detecting cardiac involvement in secondary amyloidosis although it is useful in FAP. PMID:2560088
Use of technetium-99m isonitrile (RP-30A) in assessing left ventricular perfusion and function at rest and during exercise in coronary artery disease, and comparison with coronary arteriography and exercise thallium-201 SPECT imaging
Iskandrian, A.S.; Heo, J.; Kong, B.; Lyons, E.; Marsch, S. (Philadelphia Heart Institute, PA (USA))
This study compared the results of stress and rest single-photon emission computed tomography imaging of myocardial perfusion using technetium-99m isonitrile (RP-30A) with the results of stress and redistribution tomographic thallium imaging and the results of coronary arteriography in 39 patients, 11 without and 28 with coronary artery disease (CAD). Each patient underwent 2 exercise studies at identical workload, heart rate and double product. In a subset of 13 patients, concomitant evaluation of left ventricular (LV) function using first-pass radionuclide angiography with a multi-crystal camera also was performed with bolus injections of isonitrile. Isonitrile had similar sensitivity (82 vs 82%, difference not significant), a slightly--but not significantly--higher specificity (100 vs 82%) and similar predictive accuracy (87 vs 82%) to thallium-201. The tracer uptake was assessed in 20 segments/study. There was concordance between the isonitrile and thallium-201 images in 723 of the 780 segments (93%) (kappa = 0.83 +/- 0.02). In general, the isonitrile images were considered of better quality than the thallium-201 images. All 10 patients with CAD who underwent concomitant first-pass radionuclide angiography had either perfusion abnormalities or an abnormal ejection fraction response to exercise. Thus, technetium-99m isonitrile provides a reliable method of assessment of CAD with a sensitivity, specificity and predictive accuracy comparable to that of exercise thallium-201 imaging. Additional advantages include better image quality and the ability to obtain concomitant assessment of LV function with the use of first-pass radionuclide angiography.
Clearance of Tc-99m DTPA aerosol from coal miners' lungs
Susskind, H.; Brill, A.B.; Harold, W.H.
Alterations in regional epithelial permeability were assessed in 22 retired West Virginia coal miners' lungs by measuring the clearance of inhaled 0.5-..mu..m Tc-99m DTPA aerosol. Activity was measured in both lungs and in regions of interest placed over the lung periphery in the apical, middle, and basal portions of each lung. Clearance rates (T/sub 1/2/) for 5 nonsmokers, 8 ex-smokers, and 9 smokers were significantly faster than for comparable subjects measured elsewhere, who were not coal miners. Regional apex-to-base distributions of DTPA were measured as a function of clearance time and compared with regional ventilation and perfusion. Regional, as well as overall lung clearance curves of 8 smokers and 4 ex-smokers had two components, with overall T/sub 1/2/ of <7 min for the faster one. No correlations were found between T/sub 1/2/ and DLCO or with P(A-a)O/sub 2/. The results of our study suggest that measurement of DTPA clearance is a potentially useful noninvasive technique to assess lung injury in miners exposed to coal dust. 14 refs., 6 figs., 2 tabs.
Comparison of early myocardial technetium-99m pyrophosphate uptake to early peaking of creatine kinase and creatine kinase-MB as indicators of early reperfusion in acute myocardial infarction
Kondo, M.; Yuzuki, Y.; Arai, H.; Shimizu, K.; Morikawa, M.; Shimono, Y.
The value of technetium-99m pyrophosphate (Tc-99m-PYP) scintigraphy as an indicator of reperfusion 2.8 to 8 hours after the onset of symptoms of acute myocardial infarction was compared with the value of early peak creatine kinase (CK) and CK-MB release within 16 hours after the onset of symptoms. In 29 patients who received thrombolytic therapy, recanalization was seen (group 1) and in 7 it was not (group 2). In 23 patients (79%) in group 1 scintigraphic findings were positive and in all 7 in group 2 they were negative. In 15 patients (52%) in group 1 and 1 patient (14%) in group 2, CK reached its peak level within 16 hours. In 20 patients (69%) in group 1 and 3 (43%) in group 2 the CK-MB level reached a peak within 16 hours. The sensitivity, specificity and predictive accuracy of positive results of early Tc-99m-PYP scintigraphy in predicting the reperfusion were 79%, 100% and 83%. These values are significantly higher than or similar to those of early peaking of CK and CK-MB release. In contrast to measurements of enzyme release, reperfusion data for Tc-99m-PYP scintigraphy are available immediately after thrombolytic therapy. Therefore, early Tc-99m-PYP scintigraphy (3 to 8 hours after onset of symptoms) is valuable as a noninvasive technique for early diagnosis of reperfusion.
Comparative study of rest technetium-99m sestamibi SPET and low-dose dobutamine stress echocardiography for the early assessment of myocardial viability after acute myocardial infarction: importance of the severity of the infarct-related stenosis.
Claeys, M J; Rademakers, F E; Vrints, C J; Krug, B; Bosmans, J M; Conraads, V; Bossaert, L L; Snoeck, J P; Blockx, P P
Rest technetium-99m sestamibi single-photon emission tomography (SPET) has been shown to underestimate viability in some patients with chronic ischaemic myocardial dysfunction. The present study was designed to appraise the value of 99mTc-sestamibi as a viability tracer in patients with a recent myocardial infarction and to determine factors that might influence its accuracy in assessing infarct size. Therefore, rest 99mTc-sestamibi SPET, low-dose dobutamines stress echocardiography and quantitative coronary angiography were performed in 51 patients with a recent myocardial infarction. Perfusion activity and regional wall motion were scored semi-quantitatively using the same segmental division of the left ventricle. Assessment of 99mTc-sestamibi uptake as a marker of viability was performed by comparing a binary uptake score (viable=>50% vs necrotic ==50% of the maximal tracer activity) with a binary wall motion classification during low-dose dobutamine infusion (viable=normal/hypokinetic vs necrotic=akinetic/dyskinetic). Infarct size, expressed as the number of segments with evidence of necrotic tissue, was significantly greater in the scintigraphic study than in the echocardiographic study (2.8+/-1.5 vs 2.2+/-1.3, P=0.006). This overestimation of infarct size by 99mTc-sestamibi was present only in patients with a severe infarct-related stenosis (% diameter stenosis >/=65%-100%) and particularly those with "late" reperfusion therapy (time delay >/=180 min). In patients without a severe infarct-related stenosis, 99mTc-sestamibi was able to accurately distinguish viable from necrotic segments. Thus, rest 99mTc-sestamibi scintigraphy early after acute myocardial infarction may underestimate residual viability within the infarct region, particularly in patients with low flow state coronary anatomy, as a result of a severe infarct-related stenosis and/or late reperfusion therapy. PMID:8662112
Validation of technetium-99m stannous pyrophosphate myocardial scintigraphy for diagnosing acute myocardial infarction more than 48 hours old when serum creatine kinase-MB has returned to normal
Olson, H.G.; Lyons, K.P.; Butman, S.; Piters, K.M.
Determination of lactic dehydrogenase (LDH) isoenzymes is the current method of choice for diagnosing acute myocardial infarction (AMI) greater than 48 hours old. However, other causes of enzyme elevation make the availability of an alternate method of diagnosis worthwhile. Accordingly, serial technetium-99m pyrophosphate scintigrams were obtained in 61 patients with transmural AMI and in 46 patients with subendocardial AMI. Imaging was performed in all 107 patients at the time creatine kinase isoenzyme (CK-MB) was present 37 +/- 18 hours (range 12 to 72) after the onset of AMI, and at the time CK-MB was absent 106 +/- 34 hours (range 48 to 168) after the onset of AMI. At the time CK-MB was absent, the sensitivity using either a regional or a diffuse positive scintigram was 95% (58 of 61 patients) for transmural AMI and 65% (30 of 46 patients) for subendocardial AMI. The sensitivity using a regional positive scintigram was 82% (50 of 61 patients) for transmural AMI and 37% (17 of 46 patients) for subendocardial AMI. The sensitivity using a high-grade regional positive scintigram was 36% (22 of 61 patients) for transmural AMI and 11% (5 of 46 patients) for subendocardial AMI. The specificity was 70% (143 of 204 patients) for either a regional or a diffuse abnormality, 92% (187 of 204 patients) for a regional abnormality, and 100% (204 of 204 patients) for a high-grade regional abnormality. Thus, pyrophosphate scintigraphy is useful in confirming the diagnosis of AMI, particularly transmural, greater than 48 hours old and when CK-MB has returned to normal. A positive scintigram with a high-grade regional abnormality is specific for a recent AMI and may be contributory in establishing the diagnoses when LDH isoenzymes are inconclusive.
{sup 99m}Tc DTPA aerosol clearances in the assessment of radiation injury top the lung
Halkar, R.K.; Raghab, A.; Higazi, E. [Kuwait Univ. (Kuwait)] [and others
In a prospective study, 36 patients with inoperable lung Ca. (sq. cells-24, adeno-5, largecell-2, unknown-5) underwent pre and post radiation {sup 99m}Tc DTPA aerosol clearance studies. The aim was to evaluate the value of aerosol clearance in the prediction of radiation injury to the regions other than the radiation field. Aerosol study was done using a commercially available nebulizer, dynamic images were obtained (30 sec/frame) in the posterior projection for a duration of 45 min. ROIs were drawn on upper, mid and lower zones on either lung, and time activity curves were generated. Using a linear fit, clearance half time (t{sub 1/2}) was calculated, for all six curves. The difference between pre and post radiation (t{sub 1/2}) was compared to the clinical follow up of each patient and a difference of more than 15 minutes was considered positive. Of the 36 patients 12 had a t{sub 1/2} difference of more than 15 minutes. Of these 5 patients had radiation pulmonlitis and the remaining 7 had respiratory failure due to infection and uremia. 24 patients had a t{sub 1/2} difference of less than 15 minutes and their clinical follow-up did not reveal any evidence of pulmonary radiation injury during this period. The results indicate that the clearance of Tc-99m DTPA aerosols is effective for excluding radiation pulmonlitis.
Is the addition of ECG gating to technetium-99m sestamibi SPET of value in the assessment of myocardial viability? An evaluation based on two-dimensional echocardiography following revascularization.
Gonzßlez, P; Massardo, T; Mu±oz, A; Jofrķ, J; Rivera, A; Yovanovich, J; Maiers, E; Ayala, F; Humeres, P; RamĒrez, A; Arriagada, M; Zavala, A
The main goal of this study was to evaluate whether the addition of ECG gating to technetium-99m sestamibi single-photon emission tomographic (SPET) perfusion imaging assists the prediction of recovery of regional wall motion abnormalities after revascularization. Thirty-six patients with coronary artery disease were included in the study. All had wall motion abnormalities, and 31 (86%) had a clinical history of myocardial infarction. Coronary artery bypass surgery was performed in 18 patients and angioplasty in the remainder. All underwent ECG-gated and non-gated SPET at rest and after intravenous dipyridamole. Two-dimensional echocardiography was performed at a mean of 27 days before revascularization and at a mean of 69 days following revascularization to assess segmental wall motion changes. Perfusion prior to revascularization was analysed qualitatively and quantitatively on gated and non-gated SPET, and the results compared with those of echocardiography. Bullseye parameters were obtained from a normal database, generated from data in 40 normal volunteers, using dipyridamole ECG-gated and non-gated sestamibi SPET. There was good concordance between gated and non-gated qualitative analysis (79% with kappa=0.65) for normal, viable or necrotic segments. Gated SPET predicted functional recovery in 27 of 35 (77%) segments showing echocardiographic improvement while non-gated SPET did so in 30 of 39 (77%) such segments. Gated SPET predicted no functional recovery in 20 of 45 (44%) segments that did not show improved wall motion after revascularization, while with non-gated SPET the figure was 18 of 51 (35%). The positive predictive values of gated and non-gated SPET with regard to the recovery of wall motion following revascularization were 52% and 48%, while the negative predictive values were 71% and 67%, respectively. 99mTc-sestamibi had a low predictive value for recovery of function if visual assessment was used in the analysis of SPET data. Quantitative bullseye sestamibi parameters (defect extension and severity, reversibility and percentage change in extension), from gated or non-gated studies, appear best to distinguish which segments will display improved motility on the echocardiogram after revascularization. The addition of ECG gating does not significantly increase the predictive value of SPET imaging with regard to recovery of function. PMID:8781135
Hydrated clearance of gadolinium-DTPA as a measurement of glomerular filtration rate.
Choyke, P L; Austin, H A; Frank, J A; Girton, M E; Diggs, R L; Dwyer, A J; Miller, L; Nussenblatt, R; McFarland, H; Simon, T
Technetium (99mTc)-diethylene triamine pentaacetic acid (DTPA) hydrated clearance studies are accurate for determining GFR but require special facilities for handling and measuring samples. We investigated the potential of a non-radioactive paramagnetic analog, Gadolinium (Gd)-diethylene triamine pentaacetic acid (DTPA), an approved NMR contrast agent, as a glomerular filtration marker. Instead of relying on the radioactivity of technetium, this test is based on the fact that gadolinium induces alterations in the NMR T1 relaxation times in blood and urine samples. Ninety patients underwent simultaneous determinations of GFR using 1 mCi of Tc-DTPA and 0.05 mmol/kg Gd-DTPA (Berlex Labs) IV. The patients were hydrated with oral and intravenous fluid. Following a one hour equilibrium period, three or four consecutive urine collections were obtained; plasma samples were acquired at the beginning and end of each approximately 20-minute interval. 99mTc-DTPA radioactivity was determined with a scintillation counter. T1 relaxation times were measured on a 10 MHz NMR spectrometer. These were converted to Gd-DTPA concentration by comparison with standard solutions. The Gd-DTPA derived GFR closely approximated the 99mTc-DTPA derived GFR which ranged from 15 to 147 ml/min. The equation and correlation coefficient of the regression line is y = 1.04 x -2.2, r = 0.94. Thus, Gd-DTPA is a safe, non-radioactive indicator of GFR that may provide an alternative renal clearance method for clinical studies of progressive renal disease and nephrotoxicity. PMID:1501414
Effect of raised thoracic pressure and volume on 99mTc-DTPA clearance in humans
Nolop, K.B.; Maxwell, D.L.; Royston, D.; Hughes, J.M.
Although positive airway pressure is often used to treat acute pulmonary edema, the effects on epithelial solute flux are not well known. We measured independently the effect of 1) positive pressure and 2) voluntary hyperinflation on the clearance of inhaled technetium-99m-labeled diethylenetriaminepentaacetic acid (/sup 99m/Tc-DTPA) in six nonsmokers and six smokers. Lung volumes were monitored by inductance plethysmography. Each subject was studied in four situations: 1) low end-expiratory volume (LO-), 2) low volume plus 9 cmH2O continuous positive airway pressure (LO+), 3) high end-expiratory volume (HI-), and 4) high volume plus continuous positive airway pressure (HI+). The clearance half time of 99mTc-DTPA for the nonsmokers decreased from 64.8 +/- 7.0 min (mean +/- SE) at LO- to 23.2 +/- 5.3 min at HI- (P less than 0.05). Positive pressure had no synergistic effect. The mean clearance half time for the smokers was faster than nonsmokers at base line but unaffected by similar changes in thoracic volume and pressure. We conclude that, in nonsmokers, positive airway pressure increases /sup 99m/Tc-DTPA clearance primarily through an increase in lung volume and that smokers are immune to these effects.
Septal infarction demonstrated on technetium-99m PYP SPECT.
Intenzo, C M; Koh, Y B; Madsen, M T; Park, C H
The case of a 62-year-old man with an acute myocardial infarction detected by planar Tc-99m PYP imaging is presented. The use of SPECT imaging provided more information with regard to infarct localization by demonstrating uptake by the septum, a finding not apparent on the conventional planar images. PMID:3021373
Suprarenal abscess in the neonate. Technetium-99m glucoheptonate imaging
Wells, R.G.; Sty, J.R.; Hodgson, N.B.
Although suprarenal abscess in a newborn is rare, a prompt diagnosis is essential for proper patient management. The findings obtained with Tc-99m glucoheptonate renal imaging in a newborn with a right adrenal abscess are reported. A radionuclide renal imaging sequence over a 15-hour period demonstrated a rim sign which can be used to suggest the diagnosis. Radionuclide and ultrasound imaging of neonatal adrenal masses is discussed.
Multifocal pyomyositis. Diagnosis on technetium-99m MDP bone scan
Howman-Giles, R.; McCauley, D.; Brown, J.
Pyomyositis is a bacterial infection of skeletal muscle occurring in the absence of trauma or a primary site of infection. The condition is rare in temperate climates. The diagnosis is often difficult to make and frequently delayed since the suppurative process is confined by the tense overlying muscle and fascia. The bone scan is very useful in differentiating underlying osteomyelitis and septic arthritis. An 11-year-old boy is described who presented with multifocal pyomyositis in the elbow region and thigh. Lateral blood pool images suggested infection with liquefaction within the muscles without evidence of osteomyelitis.
Technetium 99m glucarate: What will be its clinical role?
Myron C. Gerson; Anthony J. McGoron
SummaryĀĀWith publication of the studies by Khaw et al.1 and Beanlands et al.2 in this issue of the Journal, there is mounting evidence that99mTc glucarate is taken up by infarcted but not by ischemic myocardium. The early myocardial distribution and rapid blood-pool\\u000a clearance of99mTc glucarate suggest important diagnostic potential in the very early detection of acute myocardial infarction and for
Splenic uptake of both technetium-99m diphosphonate and technetium-99m sulfur colloid in sickle cell beta degrees thalassemia
Heck, L.L.; Brittin, G.M. (Methodist Hospital of Indiana, IN (USA))
A 19-year-old black woman with sickle cell beta degrees thalassemia had experienced more than 100 hospital admissions for sickle cell crisis and aseptic necrosis of both femoral heads. Her spleen was enlarged threefold and accumulated both radiocolloid and bone-seeking agent on two occasions, demonstrating an exception to the rule in sickle cell anemia that spleens that take up bone-seeking agents demonstrate functional asplenia. In the context of fever, left upper quadrant pain, and splenomegaly, the pattern of calcification in the patient's spleen as revealed in ultrasound and CT studies suggested possible abscess and led to unnecessary splenectomy. The nuclear medicine studies did not support this diagnosis. Nuclear medicine physicians should not be misled by splenic findings of sickle cell thalassemia (and possibly of other heterozygous sickle cell disorders) that differ from those of the more familiar homozygous sickle cell anemia.
Potential Role of Tc-99m DTPA Diuretic Renal Scan in the Diagnosis of Calyceal Diverticulum in Children.
Lin, Chun-Chen; Shih, Bing-Fu; Shih, Shin-Lin; Tsai, Jeng-Daw
The aim of the study was to assess the usefulness of Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) diuretic scan to diagnose calyceal diverticulum (CD).From January 2000 to June 2014, children with evidence of renal cystic lesions of undetermined diagnosis on ultrasound were enrolled. Computed tomography urography (CTU) and Tc-99m DTPA diuretic scan were performed to characterize the precise anatomy. The diagnosis of CD depended on visualization of a renal cystic lesion with filling of contrast material or radiotracer from the collecting system on CTU or diuretic renal scan. Children who had positive findings of CD on 1 or both imaging studies were selected and analyzed.Both CTU and Tc-99m DTPA diuretic renal scan were performed in 39 children. A total of 9 (23.1 %) children with CD were diagnosed. All 9 children had positive diagnosis of CD on diuretic renal scan. Only 6 (66.7%) children could be diagnosed by CTU, and CD was missed by CTU in 3 subjects. The differential renal functions in patients with CD were 46% to 55%. The time of radiotracer appearance in the CD ranged from the 8th to the 24th minute. Seven patients had persistent accumulation of radiotracer in their CD at the end of the study.Tc-99m DTPA diuretic renal scan seems to be more sensitive than CTU in diagnosing CD. The possible reasons of higher sensitivity are discussed. Additional advantages that Tc-99m DTPA diuretic renal scan provides include the following: continuous monitoring, less radiation doses, and information on renal function, making it an attractive alternative to CTU for diagnosis of CD. PMID:26091475
Asbestosis: assessment by bronchoalveolar lavage and measurement of pulmonary epithelial permeability
A R Gellert; J A Langford; R J Winter; S Uthayakumar; G Sinha; R M Rudd
Thirty two patients with asbestosis were assessed by means of bronchoalveolar lavage (27 patients) and the half time clearance from lungs to blood (T1\\/2LB) of an inhaled aerosol of diethylenetriamine pentacetate (DTPA) labelled with technetium 99m (32 patients). T1\\/2LB was also measured in 20 non-smoking normal individuals and 17 smokers without a history of exposure to asbestos. Thirteen patients (46%)
Lung clearance of /sup 99m/Tc-DTPA in patients with acute lung injury and pulmonary edema
Coates, G.; O'Brodovich, H.; Dolovich, M.
Several acute and chronic conditions that alter the integrity of the pulmonary epithelium increased the rate of absorption or clearance into the circulation of small solutes deposited in the alveoli. Technetium 99m diethylenetriamine pentaacetic acid can be deposited in the lungs as a submicronic aerosol and its rate of clearance measured with a gamma camera or simple probe. This clearance technique is currently being used to evaluate patients who have developed pulmonary edema and also to detect those patients from a high risk group who are likely to develop adult respiratory distress syndrome (ARDS). Its role in the evaluation of patients with pulmonary edema is still under active investigation. It is clear that a single measurement in patients who smoke is not useful, but repeated measurements may provide important information. The lung clearance measurement is very sensitive to changes in epithelial integrity but is not specific for ARDS. It may be most useful in combination with other predictive tests or when the clearance rate is normal. 54 references.
Abnormal captopril renogram with a technetium-99m-labeled hippuran analog
Thorstad, B.L.; Russell, C.D.; Dubovsky, E.V.; Keller, F.S.; Luke, R.G.
A case of renovascular hypertension is presented in which the (/sup 131/I)hippuran renogram was initially normal, but became strikingly abnormal upon administration of the angiotensin converting enzyme (ACE) inhibitor captopril. The patient presented with fibromuscular dysplasia of the renal arteries, which was shown by hippuran renography to be functionally significant on the right side. She became normotensive after angioplasty of the right renal artery. Hypertension recurred a year later, at which time the renogram was normal without captopril, but showed functionally significant left renal artery stenosis with captopril challenge. Both the conventional agent, (/sup 131/I)hippuran, and an experimental new /sup 99m/Tc-labeled hippuran analog, (/sup 99m/Tc)MAG3, were used. Angiography confirmed progression of disease on the left side, which was successfully treated by angioplasty. Functionally significant unilateral renal artery stenosis was thus demonstrated first on the right side and then, 1 yr later, on the left side, using hippuran and (/sup 99m/Tc)MAG3. Anatomic progression of disease was documented by angiography.
Adrenal imaging with technetium-99m-labelled low density lipoproteins
Isaacsohn, J.L.; Lees, A.M.; Lees, R.S.; Kovach, M.B.; Strauss, H.W.
Plasma low density lipoproteins (LDL) are a major source of cholesterol for adrenal cortical steroid hormones synthesis. To test whether LDL labelled with Tc-99m could be used to assess adrenal cortical function, the authors prepared Tc-99m-LDL by dithionite reduction of Tc0/sub 4//sup -/ in the presence of LDL. About 80% of the Tc-LDL bonds were covalent. Purified Tc-99m-LDL was injected intravenously into 16 rabbits (4 t 8mCi/rabbit). External imaging was carried out 16 to 18 hrs later, at which time the adrenals were visualized clearly; the animals were sacrificed, the organs dissected out, weighed, and counted. The biodistribution demonstrated that 0.8l +- 0.19% of the injected radioactivity was taken up per gm of whole adrenal gland. This compared with an uptake of 0.19 +- 0.02% per gm by liver, 0.22 +- 0.04% per gm by spleen, and 0.11 +- 0.02% per gm by kidney. To verify that they were indeed imaging the adrenals, additional rabbits were tested with dexamethasone. First they were injected with Tc-99m-LDL; 28 hrs later the adrenals were again well visualized. Then the rabbits were given dexamethasone for 5 days to suppress adrenal cortical function. The adequacy of suppression was monitored by serum cortisol measurements. When Tc-99m-LDL was injected again, the adrenals could not be seen 18 hrs later. Counts of the adrenals from the suppressed rabbits were at background levels. These data indicate that Tc-99m-LDL is a useful radiopharmaceutical for evaluating adrenal cortical function.
Adrenal imaging with technetium-99m-labelled low density lipoproteins
Isaacsohn, J.L.; Lees, A.M.; Lees, R.S.; Strauss, H.W.; Barlai-Kovach, M.; Moore, T.J.
Evaluation of adrenal cortical function by external imaging is currently accomplished by injection of radiolabelled analogs of cholesterol. Although the adrenals do utilized exogenous cholesterol for steroid hormone synthesis, the cholesterol is delivered to the glands not as free cholesterol but through the uptake of low density lipoproteins (LDL), which are subsequently degraded within the adrenal cortical cells to provide cholesterol. Thus, we sought to assess the use of /sup 99m/Tc-labelled LDL injected into rabbits to obtain external images of the adrenal glands. Adrenal images of all nine rabbits tested were obtained within 18 to 21 hours after injection of /sup 99m/Tc-LDL. Seven of the rabbits were subjected to adrenal cortical suppression with dexamethasone and then all nine rabbits were imaged a second time. In the untreated animals, visualization of the adrenal glands was accompanied by normal serum cortisol concentrations and accumulation of radiolabel in the adrenals, whereas in the dexamethasone-treated animals, lack of visualization of the adrenal glands was correlated with low serum cortisols, and greatly decreased accumulation of the radionuclide in the adrenals. These findings demonstrate for the first time that LDL, when labelled with /sup 99m/Tc, can be used to evaluate adrenal cortical function by external imaging.
Technetium-99m-methylene Diphosphonate Uptake in Hepatic Necrosis Secondary to Respiratory Failure.
Mahajan, Madhuri Shimpi; Digamber, Negi S; Sharma, Rajkumar
Tc-99m methylene diphosphonate (MDP) bone scintigraphy has long been used for the evaluation of benign as well as malignant skeletal conditions. However, non-osseous tracer uptake on a bone scan is an unusual finding. On one hand, there is a need for awareness of the pathophysiologic basis underlying such uptake, as it may be of critical clinical relevance in the evaluation of the patient. On the other hand, some alterations in biodistribution may be of little clinical significance, but have deleterious consequences on the quality of the bone study. Recognition of these abnormalities will reduce errors and provide important clinical information. We described a case of 57-year-old male patient with history of carcinoma base of tongue, where a 99mTc-MDP bone Scintigraphy was performed for metastasis survey. It revealed avascular necrosis of head of right femur. In addition incidentally demonstrated diffuse increased pathologic uptake of Tc-99m-MDP in the liver and multiple foci in bilateral lungs. This article reviews several possible reasons for such diffuse hepatic uptake. In the present case diffuse hepatic necrosis secondary to respiratory failure due to bilateral miliary pulmonary metastasis is considered to be the cause of the diffuse liver uptake of 99mTc-MDP. PMID:25165422
Technetium-99m-d,1-hexamethylpropyleneamine oxime (HMPAO) uptake and glutathione content in brain tumors.
Suess, E; Malessa, S; Ungersb÷ck, K; Kitz, P; Podreka, I; Heimberger, K; Hornykiewicz, O; Deecke, L
Technetium-d, HMPAO SPECT was performed in 70 patients suffering from intracerebral tumors of various histologic types (glioma n = 30, meningioma n = 19, metastases n = 10, angioma n = 3, neuroma n = 2, lymphoma n = 2, neurocytoma n = 1, epidermoid n = 1, gliosis n = 1, cholesteatoma n = 1). Tumor classification was histologically verified in all subjects except in two cases with inoperable angiomas. SPECT was performed under resting state conditions with a dual-head rotating camera (SIEMENS ZLC 37) following intravenous injection of 18-25 mCi 99mTc-d, 1-HMPAO. Regional tracer deposit was expressed in terms of a cerebellar index (CBI). Significantly higher regional HMPAO uptake was found in meningiomas when compared with gliomas of different malignancy (ANOVA p less than 0.05). Within gliomas, regional uptake increased with malignancy (n.s.). In 23 patients, a total of 32 tumor specimens were obtained for histochemical analysis of glutathione (GSH) content using high-pressure liquid chromatography. A significant correlation (least square method, p less than 0.001) between CBIs and GSH values was found, supporting the hypothesis that GSH is the predominant factor for the conversion of the lipophilic complex to hydrophilic derivates. PMID:1880567
Technetium99m-d,1-Hexamethyipropyleneamine Oxime (HMPAO) Uptake and Glutathione Content in Brain Tumors
E. Suess; S. Malessa; K. Ungersbock; P. Kitz; I. Podreka; K. Heimberger; L. Deecke
Technetium-d,HMPAO SPECTwas performedin 70 patients sufferingfrom intracerebraltumors of varioushistologictypes (glioma n = 30, meningeoman = 19, metastases n = 10, angioma n= 3, neuroma n= 2, lymphoma n= 2, neurocytoma n = 1, epidermoidn = 1, gliosis n = 1, cholesteatoman = 1). Tumorclassification was histologically verifiedin allsubjects except in two cases with inoperableangiomas.SPECTwas performed under resting state conditions with
New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems
Rogers, R.D.; Bond, A.H.; Zhang, Jianhua [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Chemistry; Horwitz, P. [Argonne National Lab., IL (United States)
Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.
Abdominal varices mimicking an acute gastrointestinal hemorrhage during technetium-99m red blood cell scintigraphy
Moreno, A.J.; Byrd, B.F.; Berger, D.E.; Turnbull, G.L.
Abdominal varices consisting of a caput medusae and dilated mesenteric veins resulted in pooling of Tc-99m tagged red blood cells (RBC) within these dilated vessels in a 57-year-old man with severe Laennec's cirrhosis. The atypical radiotracer localization within the abdomen mimicked an acute gastrointestinal hemorrhage. Clinical suspicion and careful evaluation of scintigraphic gastrointestinal bleeding studies will avoid false-positive interpretations.
Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Application in liver transplantation
Woodle, E.S.; Ward, R.E.; Vera, D.R.; Stadalnik, R.C.
Tc-NGA is a new liver imaging agent which binds to hepatic binding protein (HBP), a hepatocyte-specific membrane receptor. The purpose of the present study was to evaluate the potential role of Tc-NGA imaging in liver transplantation. The molar Tc-NGA dose was standardized according to patient weight (0.7 nmole/kg). After a 30 minute dynamic imaging study (5 mCi, IV), kinetic analysis of time activity data (heart, liver), provided values for receptor concentration, (HBP), and hepatic blood flow, Q. Eleven Tc-NGA imaging studies were performed in transplant candidates and 22 studies were performed in seven transplant recipients. Preservation damage was manifested by diffuse patchiness in tracer distribution which resolved during the following two weeks. Histologically proven, localized hepatic infarcts were demonstrated in three recipients. Lobar infarction was demonstrated in one recipient. Hepatic regeneration was later demonstrated in this patient after hepatic lobectomy. Hepatic blood flow was markedly decreased in the early postoperative period, but improved with time. Increased (HBP) was demonstrated with regeneration. Markedly decreased (HBP) and Q were obtained in several candidates who died awaiting transplantation. These studies indicate that TC-NGA liver imaging provides a valuable new means for: (1) evaluation of preservation damage, (2) early demonstration of hepatic infarction, (3) evaluation of hepatic rejection, and (4) selection of patients for hepatic transplantation.
Kinetic sensitivity of a receptor-binding radiopharmaceutical: Technetium-99m galactosyl-neoglycoalbumin
Vera, D.R.; Woodle, E.S.; Stadalnik, R.C. (Univ. of California, Davis (USA))
Kinetic sensitivity is the ability of a physiochemical parameter to alter the time-activity curve of a radiotracer. The kinetic sensitivity of liver and blood time-activity data resulting from a single bolus injection of ({sup 99m}Tc)galactosyl-neoglycoalbumin (( Tc)NGA) into healthy pigs was examined. Three parameters, hepatic plasma flow scaled as flow per plasma volume, ligand-receptor affinity, and total receptor concentration, were tested using (Tc)NGA injections of various molar doses and affinities. Simultaneous measurements of plasma volume (iodine-125 human serum albumin dilution), and hepatic plasma flow (indocyanine green extraction) were performed during 12 (Tc)NGA studies. Paired data sets demonstrated differences (P(chi v2) less than 0.01) in liver and blood time-activity curves in response to changes in each of the tested parameters. We conclude that the (Tc)NGA radiopharmacokinetic system is therefore sensitive to hepatic plasma flow, ligand-receptor affinity, and receptor concentration. In vivo demonstration of kinetic sensitivity permits delineation of the physiologic parameters that determine the biodistribution of a radiopharmaceutical. This delineation is a prerequisite to a valid analytic assessment of receptor biochemistry via kinetic modeling.
Evaluation in dogs and humans of three potential technetium-99m myocardial perfusion agents
Gerundini, P.; Savi, A.; Gilardi, M.C.; Margonato, A.; Vicedomini, G.; Zecca, L.; Hirth, W.; Libson, K.; Bhatia, J.C.; Fazio, F.
The biodistribution of the three cationic /sup 99m/Tc complexes (/sup 99m/Tc(TMP)6)+, (/sup 99m/Tc(POM-POM)3)+, and (/sup 99m/Tc(TBIN)6)+--where TMP represents trimethylphosphite, POM-POM represents 1,2-bis(dimethyoxyphosphino)ethane, and TBIN represents t-butylisonitrile--have been evaluated in humans and dogs. Each agent was studied in three normal volunteers at rest, while (/sup 99m/Tc(POM-POM)3)+ and (/sup 99m/Tc(TBIN)6)+ were each studied in one normal volunteer at exercise. Even though all three agents yield good myocardial images in dogs, none appear suitable for clinical use as myocardial perfusion imaging radiopharmaceuticals. In humans, (/sup 99m/Tc(TMP)6)+ and (/sup 99m/Tc(POM-POM)3)+ clear very slowly from the blood and provide myocardial images only several hours after injection. (/sup 99m/Tc(TBIN)6)+ clears rapidly from the blood, but accumulation in the lung obscures the myocardial image for the first hour after injection; at later times, activity in the liver and spleen masks the apical wall. These results correlate with the blood-binding properties of the three complexes. (/sup 99m/Tc(TMP)6)+ and (/sup 99m/Tc(POM-POM)3)+ bind tightly to the plasma of human blood, but not to the plasma of dog blood; (/sup 99m/Tc(TBIN)6)+ does not bind tightly to the plasma of either dog or human blood. Among the Tc(I) complexes studied to date in humans, (/sup 99m/Tc(TBIN)6)+ appears to be unique in biodistribution pattern, blood-binding properties, and the fact that exercise improves the ultimate myocardial image. All the Tc(I) complexes appear to undergo myocardial accumulation by a mechanism different from that utilized by Tc(III) complexes. Animal studies alone are not adequate to evaluate the potential utility of /sup 99m/Tc cationic complexes for myocardial perfusion studies.
Protein binding studies of technetium-99m-labeled phosphine and isocyanide cationic complexes
Zanelli, G.D.; Cook, N.; Lahiri, A.; Ellison, D.; Webbon, P.; Woolley, G.
Most /sup 99m/Tc/phosphine/isocyanide complexes synthesized to date show preferential uptake by the myocardium of many animal species but not in man. A new complex has been synthesized, (/sup 99m/Tc(DEPE)2(CNR)2), +(DEPIC), where R = t - butyl isocyanide, which in three animal species images the myocardium very well, but in humans it remains primarily in the blood pool. One reason for the difference in the behavior of these complexes in different species could be the characteristics of their binding to plasma proteins. The protein binding characteristics of DEPIC and two other well-known complexes have therefore been studied. Whereas the other complexes bind nonspecifically to many proteins both in animal and human plasma, DEPIC binds almost exclusively to prealbumin in humans but nonspecifically to other proteins in the rabbit. The binding sites in human plasma appear to be those normally occupied by thyroxine on the prealbumin tetramer and these can be blocked by sodium salicylate.
Synthesis and biological evaluation of a technetium-99m(I)-tricarbonyl-labelled phenyltropane derivative
Davy M. Kieffer; Bernard J. Cleynhens; Hubert P. Vanbilloen; Dirk Rattat; Christelle Y. Terwinghe; Luc Mortelmans; Guy M. Bormans; Alfons M. Verbruggen
A new tropane derivative was synthesized by combining a tridentate ligand, N-(2-picolylamine)-N-acetic acid (2-PAA), and a phenyltropane derivative. It was labelled with a [99mTc(CO)3]+ moiety, resulting in the formation of two stable and neutral lipophilic isomers. Their identity was confirmed using radio-LC¢MS. In normal mice, no brain uptake was observed for any of the isomers and in vitro autoradiography using
Evaluation of alternative rapid thin layer chromatography systems for quality control of technetium-99m radiopharmaceuticals.
Mang'era, Kennedy; Wong, Derek; Douglas, David; Franz, Kellie; Biru, Taddese
Whatman 3MMÖ and Tec-ControlÖ systems were evaluated as ITLC-SG alternatives for 99mTc-radiopharmaceuticals. They compare well in accuracy and reproducibility, and are faster and more convenient than ITLC-SG. Tec-ControlÖ radiochemical purity values for 99mTc-sestamibi were more conservative than ITLC-SG. Full solvent migration was not reproduced for 99mTc-tetrofosmin in Tec-ControlÖ, and for this Whatman 3MMÖ is preferred. Developing times were 10-15 min, 7-9 min and ~1min for ITLC-SG, Whatman 3MMÖ and Tec-ControlÖ, respectively. Overall, Tec-ControlÖ strips are preferred due to speed and ease of use. PMID:24491376
Technetium 99m-methylene diphosphonate bone scans in children with reflex neurovascular dystrophy
Laxer, R.M.; Allen, R.C.; Malleson, P.N.; Morrison, R.T.; Petty, R.E.
Eleven children with reflex neurovascular dystrophy were investigated by technetium-labeled methylene diphosphonate bone scanning. Eight of 12 scans demonstrated abnormal findings, four showing diffusely decreased uptake and four diffusely increased uptake of the radionuclide in the affected site. Three scans showed normal findings initially, as did one previously abnormal scan when repeated in the asymptomatic patient 6 months later. Diffusely abnormal findings can be helpful in the diagnosis of childhood reflex neurovascular dystrophy, but a normal scan does not exclude the diagnosis.
Technetium-99m-methylene Diphosphonate Uptake in Hepatic Necrosis Secondary to Respiratory Failure
Mahajan, Madhuri Shimpi; Digamber, Negi S.; Sharma, Rajkumar
Tc-99m methylene diphosphonate (MDP) bone scintigraphy has long been used for the evaluation of benign as well as malignant skeletal conditions. However, non-osseous tracer uptake on a bone scan is an unusual finding. On one hand, there is a need for awareness of the pathophysiologic basis underlying such uptake, as it may be of critical clinical relevance in the evaluation of the patient. On the other hand, some alterations in biodistribution may be of little clinical significance, but have deleterious consequences on the quality of the bone study. Recognition of these abnormalities will reduce errors and provide important clinical information. We described a case of 57-year-old male patient with history of carcinoma base of tongue, where a 99mTc-MDP bone Scintigraphy was performed for metastasis survey. It revealed avascular necrosis of head of right femur. In addition incidentally demonstrated diffuse increased pathologic uptake of Tc-99m-MDP in the liver and multiple foci in bilateral lungs. This article reviews several possible reasons for such diffuse hepatic uptake. In the present case diffuse hepatic necrosis secondary to respiratory failure due to bilateral miliary pulmonary metastasis is considered to be the cause of the diffuse liver uptake of 99mTc-MDP. PMID:25165422
Uptake and clearance analysis of Technetium(99m) labelled iron oxide nanoparticles in a rabbit brain.
Nadeem, Muhammad; Ahmad, Munir; Saeed, M A; Shaari, Amiruddin; Riaz, Saira; Naseem, Shahzad; Rashid, Khalid
Nanoparticles as solid colloidal particles are extensively studied and used as anticancer drug delivery agents because of their physical properties. This current research aims to prepare water base suspension of uncoated iron oxide nanoparticles and their biodistribution study to different organs, especially the brain, by using a single photon emission computed tomography gamma camera. The water-based suspension of iron oxide nanoparticles was synthesised by a reformed version of the co-precipitation method and labelled with Tc(99m) for intravenous injection. The nanoparticles were injected without surface modification. X-ray diffraction (XRD), energy dispersive spectrometry (EDS) and transmission electron microscope (TEM) techniques were used for characterisation. Peaks of XRD and EDS indicate that the particles are magnetite and exist in aqueous suspension. The average diameter of iron oxide nanoparticles without any surface coating determined by TEM is 10 nm. These particles are capable of evading the reticuloendothelial system and can cross the blood-brain barrier in the rabbit. The labelling efficiency of iron oxide nanoparticles labelled with Tc(99m) is 85%, which is good for the biodistribution study. The sufficient amount of iron oxide nanoparticles concentration in the brain as compared with the surrounding soft tissues and their long blood retention time indicates that the water-based suspension of iron oxide nanoparticles may be an option for drug delivery into the brain. PMID:26023157
Sequential technetium-99m/gallium-67 scintigraphic evaluation of subclinical osteomyelitis complicating fracture nonunion
Esterhai, J.; Alavi, A.; Mandell, G.A.; Brown, J.
Twenty-four patients with a history of post-traumatic fracture nonunion underwent sequential /sup 99m/Tc and /sup 67/Ga citrate scintigraphy in an attempt to differentiate between posttraumatic fracture nonunion and nonunion complicated by subclinical osteomyelitis. Neither technetium nor gallium studies alone nor in combination, with or without clinical correlation, could help delineate between fracture nonunion and nonunion complicated by subclinical osteomyelitis because of the increased technetium and gallium radioisotope uptake associated with the nonunion site.
Calf muscle arteriovenous malformations detected by technetium-99m erythrocyte venography
O'Donnell, C.; Andrews, J.
Two cases of calf muscle arteriovenous malformation in young women, presenting clinically as deep venous thrombosis, were initially detected by Tc-99m erythrocyte venography and later confirmed by arteriography. The role of this technique in the investigation of venous thrombosis is discussed, emphasizing the importance of the lateral calf view.
Avidity of technetium 99m glucarate for the necrotic myocardium: In vivo and in vitro assessment
Ban-An Khaw; Atsuko Nakazawa; Sean M. O'Donnell; Koon-Yan Pak; Jagat Narula
BackgroundĀĀSimilar to other99mTc-based infarct-avid agents,99mTc-glucarate localizes in myocardial infarcts. Whether severely ischemic viable myocytes sequester99mTc-glucarate is uncertain. To assess the infarct specificity, in vitro and in vivo studies were performed.\\u000a \\u000a \\u000a \\u000a Methods and ResultsĀĀH9C2 embryonic rat cardiocytes cultured under normoxia (N) or hypoxia (H) for 24 hours in 7.5 ?Ci99mTc-glucarate were compared with necrotic cardiocytes. Mean H\\/N ratio (3.0▒0.004, mean▒SD) was
Technetium99m glucarate uptake in a swine model of limited flow plus increased demand
Lynne L. Johnson; Lorraine Schofield; Patricia Mastrofrancesco; Tammy Donahay; Andrew Farb; Ban An Khaw
BackgroundĀĀGlucarate is a 6-carbon dicarboxylic acid shown to be taken up by necrotic myocytes, binding to nuclear histones in animal\\u000a models of coronary occlusion, resulting in infarction. This study investigated glucarate uptake in a model of severe ischemia.\\u000a \\u000a \\u000a \\u000a Methods and ResultsĀĀThirty-five experiments were performed, in which a catheter-mounted stenosis (reducing lumen dimensions by 80%) was placed\\u000a in the left anterior
Differentiation of myocardial ischemia and necrosis by technetium 99m glucaric acid kinetics
Rob S. B. Beanlands; Terrence D. Ruddy; Lewanda Bielawski; Helen Johansen
BackgroundĀĀCurrent clinical approaches may not always be helpful in the early differentiation of necrotic tissue from ischemic viable\\u000a myocardium in patients with acute myocardial infarction. Tc-99m-glucaric acid is a carbohydrate ligand that may permit differentiation\\u000a of necrosis from ischemia. However, the myocardial kinetics of Tc-99m-glucaric acid have not been well defined early after\\u000a myocardial injury. The aim of this study
In vivo hybridization of technetium-99m-labeled peptide nucleic acid (PNA)
G. Mardirossian; K. Lei; M. Rusckowski
Hybridization of a radiolabeled single-stranded DNA oligonucleotide with its single-stranded complement in vivo has not yet been convincingly demonstrated. A contributing factor may be unfavorable in vivo properties of the phosphodiester and phosphorothioate DNAs. Peptide nucleic acid (PNA) oligomers have been reported to possess in vivo properties more suitable for radiopharmaceutical applications. We have radiolabeled an amine-derivatized 15-base PNA oligomer
Environmental Fate of EDTA and DTPA
Mika SillanpiHi
\\u000a EDTA can be extremely persistent in WWTP and also in natural waters; DTPA seems more biodegradable. However, the biodegradability\\u000a of DTPA might be of negligible significance as EDTA is reported to be one of its decomposition products. EDTA, and in some\\u000a cases also DTPA, are generally found in the receiving waters of many industrial areas, thus being classified as one
Compartmental analysis of technetium-99m-teboroxime kinetics employing fast dynamic SPECT at rest and stress
Chiao, P.C.; Ficaro, E.P.; Dayaniki, F. [Univ. of Michigan Medica Center, Ann Arbor, MI (United States)] [and others
The authors have examined the feasibility of compartmental analysis of {sup 99m}Tc-teboroxime kinetics in measuring physiological changes in response to adenosine-induced coronary vasodilation. To evaluate the effect of tracer recirculation on {sup 99m}Tc-teboroxime kinetics in the myocardium, they also compared compartmental analysis with washout analysis (monoexponertial fitting), which does not account for this effect. Eight healthy male volunteers were imaged using fast dynamic SPECT protocols (5 sec per tomographic image) at rest and during adenosine infusion. A two-compartment model was used and compartmental parameters K1 and k2 (characterizing the diffusion of {sup 99m}Tc-teboroxime from the blood to the myocardium and from the myocardium to the blood, respectively) were fitted from myocardial time-activity curves and left ventricular input functions. Both K1 and washout estimates for the whole left ventricular myocardium changed significantly in response to coronary vasodilation. Mean stress-to-rest (S/R) ratios were almost two times higher for K1 (S/R = 2.7 {plus_minus} 1.1) than for washout estimates (S/R = 1.5 {plus_minus} 0.3). Estimation of K1 for all local regions, except the septal wall, is feasible because variations in K1 estimates for all local regions, except the septum during stress, are comparable with those for the global region. The authors conclude that quantitative compartmental analysis of {sup 99m}Tc-teboroxime kinetics provides a sensitive indicator for changes in response to adenosine-induced coronary vasodilation. 39 refs., 7 figs., 1 tab.
[Pulmonary perfusion scintigraphy. Feasibility of quantitative thoracic tomography using the detection of gamma ray dispersion from technetium-99m].
Cuar¾n, A
Attenuation of gama radiation (140 KeV) from a punctual source of 99mTc was investigated in materials with a similar density to that of human chest tissues: air, saw dust (lungs), and water (chest wall and mediastinic organs). Half-value thickness (A 1/2) and linear attenuation coefficients (u) were measured for each material. With these experimental data, attenuation of the primary radiation beam and intensity of Compton effect at an angle of 90 degrees were calculated at different depths of a theoretical model of a human chest, assuming a primary radiation beam with a direction from right-to-left, and the inverse. The results demonstrated the theoretical possibility of obtaining quantitative tomographic bidimensional images of the tissular densitometry of the hemi-t¾rax near the radiation source, by means of the detection of the gama photons scattered al 90 degrees as a result of Compton effect. Attenuation of the primary beam prevents the obtaintion of information from the far sided hemitorax. Theoretical considerations for the correction of this defect of the low energy gama photons from 99mTc are discussed. It was decided to design and built a system for the experimental evaluation of this new principle for clinical exploration, which can be used as a low cost and simple adjuvant to increase the specificity of perfusion lung scintigraphy. PMID:6087749
Technetium-99m-labeled long chain fatty acid analogues metabolized by beta-oxidation in the heart.
Uehara, Tomoya; Uemura, Tomoe; Hirabayashi, Seiji; Adachi, Sayaka; Odaka, Kenichi; Akizawa, Hiromichi; Magata, Yasuhiro; Irie, Toshiaki; Arano, Yasushi
The development of 99mTc-labeled fatty acid analogues metabolized by beta-oxidation in the myocardium constitutes an unsolved challenge. On the basis of our recent findings that [188Re]tricarbonyl(cyclopentadienylcarbonate)rhenium ([188Re]CpTR-COOH) was recognized as an aromatic compound and was metabolized as such in the body, [99mTc]cyclopentadienyltricarbonyltechnetium ([99mTc]CpTT) was conjugated at the omega-position of pentadecanoic acid to prepare [99mTc]CpTT-PA. When injected into rats, [99mTc]CpTT-PA exhibited the maximum myocardial accumulation and heart-to-blood ratio of 3.85 %ID/g at 1 min and 4.60 at 10 min postinjection, respectively. The metabolic study using isolated Langendorff perfused rat hearts demonstrated that approximately 67% of perfused [99mTc]CpTT-PA was incorporated and [99mTc]CpTT-propionic acid, the metabolite after six cycles of beta-oxidation of [99mTc]CpTT-PA, was detected as the major radiometabolite in the perfusate and myocardium. These findings indicate that [99mTc]CpTT-PA was recognized, transported, and metabolized as a long chain fatty acid analogue for energy production in the myocardium. PMID:17266206
Technetium-99m DISIDA hepatobiliary agent in diagnosis of hepatocellular carcinoma: relationship between detectability and tumor differentiation
Calvet, X.; Pons, F.; Bruix, J.; Bru, C.; Lomena, F.; Herranz, R.; Brugera, M.; Faus, R.; Rodes, J.
The present investigation was aimed to assess the usefulness of biliary agents scintigraphy in the diagnosis of hepatocellular carcinoma (HCC) and to ascertain the relationship between the uptake of these agents and the degree of HCC differentiation. Forty-four patients with this hepatic cancer were included in the study. Liver scans were performed 20 min and 3 hr after the administration of 99mTc diisopropyliminodiacetic acid (DISIDA). DISIDA scintigraphy could not be assessed in six cases. In 16 (42%) out of the remaining 38 patients, the tumor exhibited equal or greater radioactivity uptake than the surrounding liver. In six out of these 16 patients, tumor uptake was apparent in the early and delayed hepatic scans, while in the other ten subjects radioactivity uptake by the HCC could only be detected in the 3-hr delayed scans. In the remaining 22 patients, HCC appeared as a cold area. Tumor location by this technique did not differ from that observed by 99mTc-sulfur colloid scan or ultrasound. DISIDA uptake was significantly related to tumor differentiation: 70% of those well differentiated tumors exhibited DISIDA uptake, whereas it was found in only 30% of those moderately differentiated and in none of those poorly differentiated (p less than 0.05). These results show that DISIDA scintigraphy can be useful in the diagnosis of HCC. Since its sensitivity is related to the degree of tumor differentiation, it may be indicated when aspiration cytology is unable to distinguish between well differentiated HCC and reactive changes due to hepatic cirrhosis.
Diagnosis of sclerosing cholangitis with technetium 99m-labeled iminodiacetic acid planar and single photon emission computed tomographic scintigraphy
Rodman, C.A.; Keeffe, E.B.; Lieberman, D.A.; Krishnamurthy, S.; Krishnamurthy, G.T.; Gilbert, S.; Eklem, M.J.
The purpose of this study was to determine whether /sup 99m/Tc-iminodiacetic acid planar biliary scintigraphy combined with single photon emission computed tomography could detect sclerosing cholangitis and provide additional information regarding the extent and severity of disease. Thirteen patients with sclerosing cholangitis and 13 normal control subjects were studied. Scintigraphic results were also compared with previously reported studies of patients with isolated common bile duct obstruction and with primary biliary cirrhosis. The planar scintigraphy in patients with sclerosing cholangitis showed beading or bandlike constrictions of the biliary tract corresponding to lesions seen on cholangiography, and the image pattern was distinctly different from images obtained from patients with isolated common bile duct obstruction or primary biliary cirrhosis. The single photon emission computed tomography images of the liver in patients with sclerosing cholangitis demonstrated multiple focal areas of /sup 99m/Tc-iminodiacetic acid retention, representing bile stasis in intrahepatic bile ducts. Compared to controls, the mean hepatic clearance half-time of /sup 99m/Tc-iminodiacetic acid was markedly delayed in patients with sclerosing cholangitis (6-10 times normal). Individual patients with sclerosing cholangitis had wider variation in isotope clearance half-time from three regions of the liver than patients with isolated common bile duct obstruction, consistent with regional difference in disease severity and variable impairment of bile flow. In 4 patients with sclerosing cholangitis with incomplete filling of the right and left hepatic ducts at cholangiography, planar and single photon emission computed tomographic scintigraphy provided evidence of significant intrahepatic sclerosing cholangitis.
Effect of Peumus boldus on the labeling of red blood cells and plasma proteins with technetium-99m.
Reiniger, I W; de Oliveira, J F; Caldeira-de-Ara·jo, A; Bernardo-Filho, M
Peumus boldus is used in popular medicine in Brazil. The influence of Peumus boldus on the labeling of red blood cells and plasma proteins with 99mTc was studied. Stannous chloride and 99mTc pertechnetate were incubated with blood and a tincture of Peumus boldus. Aliquots of plasma and blood cells were isolated from the mixture and treated with trichloroacetic acid (TCA). After separation, analysis of the soluble and insoluble fractions showed a rapid uptake of the radioactivity by blood cells in the presence of the drug, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. PMID:10376326
Assessment of left ventricular systolic and diastolic function using ECG-gated technetium-99m tetrofosmin myocardial perfusion SPECT.
Mizunobu, Mayumi; Sakai, Jun; Sasao, Hisataka; Murai, Hiroshi; Fujiwara, Hidetoshi
Because left ventricular (LV) diastolic dysfunction is frequently the earliest indicator of LV dysfunction in patients with heart failure, the estimation of LV diastolic function is very important. On the other hand, electrocardiography (ECG)-gated technetium (Tc) -99m tetrofosmin single-photon emission computed tomography (SPECT) has been reported to be a useful method for evaluation of LV function. The objective of this study was to examine the usefulness of ECG-gated Tc-99m tetrofosmin SPECT in terms of estimation of cardiac diastolic function. Consecutive 145 patients underwent an ECG-gated Tc-99m tetrofosmin SPECT to estimate systolic and diastolic LV function, and were compared with those evaluated by ultrasound echocardiography (UCG). LV end-diastolic volume, LV end-systolic volume, and LV ejection fraction values obtained by quantitative gated SPECT (QGS) showed significant positive linear correlations with those obtained by UCG. All 145 patients were classified into 3 groups according to diastolic function estimated by UCG. The first-third mean filling rate (1/3 MFR) and peak filling rate (PFR) that revealed the LV diastolic function of the group B (normal systolic function and mild diastolic dysfunction) patients (1.01 ▒ 0.35, 1.85 ▒ 0.57) were both significantly lower than those of the group A (normal systolic and diastolic function) patients (1.43 ▒ 0.37, 2.43 ▒ 0.56). The 1/3 MFR and PFR of the group C (moderate ~ severe systolic and diastolic dysfunction) patients (0.47 ▒ 0.34, 0.92 ▒ 0.62) were also significantly lower than those of the group A and B patients. QGS may be a useful method for the evaluation of cardiac systolic and diastolic function, especially in patients with normal systolic function and diastolic dysfunction. PMID:23924933
Global Xenon-133 Emission Inventory Caused by Medical Isotope Production and Derived from the Worldwide Technetium-99m Demand
NASA Astrophysics Data System (ADS)
Kalinowski, Martin B.; Grosch, Martina; Hebel, Simon
Emissions from medical isotope production are the most important source of background for atmospheric radioxenon measurements, which are an essential part of nuclear explosion monitoring. This article presents a new approach for estimating the global annual radioxenon emission inventory caused by medical isotope production using the amount of Tc-99m applications in hospitals as the basis. Tc-99m is the most commonly used isotope in radiology and dominates the medical isotope production. This paper presents the first estimate of the global production of Tc-99m. Depending on the production and transport scenario, global xenon emissions of 11-45 PBq/year can be derived from the global isotope demand. The lower end of this estimate is in good agreement with other estimations which are making use of reported releases and realistic process simulations. This proves the validity of the complementary assessment method proposed in this paper. It may be of relevance for future emission scenarios and for estimating the contribution to the global source term from countries and operators that do not make sufficient radioxenon release information available. It depends on sound data on medical treatments with radio-pharmaceuticals and on technical information on the production process of the supplier. This might help in understanding the apparent underestimation of the global emission inventory that has been found by atmospheric transport modelling.
Clinical application of autologous technetium-99m-labelled eosinophils to detect focal eosinophilic inflammation in the lung
Loutsios, Chrystalla; Farahi, Neda; Simmonds, Rosalind; Cullum, Ian; Gillett, Daniel; Solanki, Chandra; Solanki, Kishor; Buscombe, John; Condliffe, Alison; Peters, Michael A.; Chilvers, Edwin
with a background of asthma, presented with a 14-month history of increasing wheeze and cough, followed by an acute deterioration with breathlessness, weight loss and anorexia. On admission, he was haemodynamically unstable and severely hypoxaemic...
The use of technetium-99m pertechnetate in postoperative thyroid carcinoma. A comparative study with iodine-131.
Khammash, N F; Halkar, R K; Abdel-Dayem, H M
Over 3 years, a prospective comparison was made between Tc-99m pertechnetate and I-131 for the detection of residual and metastatic tissue in the follow-up of patients with cancer of the thyroid. All patients stopped thyroid medication for a minimum of 4 weeks. All patients had imaging done first with Tc-99m pertechnetate followed within a maximum of 2 weeks by I-131. The study included 66 patients in whom 81 studies were done with both Tc-99m and I-131. The results showed that 27 studies were positive with both Tc-99m and I-131 (true positive): 19 in the thyroid bed, four lymph nodes, two bony metastases, and two pulmonary metastases. Five patients had negative results with Tc-99m and positive results with I-131 (false negative): three in the thyroid bed, one lymph node metastasis, and one pulmonary metastasis. Only one case was positive with Tc-99m in the neck but negative with I-131 (false positive). The remaining 48 studies were negative both with Tc-99m and I-131 (true negative). Considering I-131 imaging as the standard procedure, Tc-99m had a sensitivity of 87%, specificity of 97%, and accuracy of 92.5% for the detection of residual or metastatic functioning thyroid tissue. PMID:2832116
Filling out phenomenon with technetium-99m HM-PAO brain SPECT at the site of mild cerebral ischemia
Hayashida, K.; Nishimura, T.; Imakita, S.; Uehara, T.
Although the distribution of (/sup 99m/Tc)hexamethylpropyleneamine oxime (HM-PAO) in the brain is said to be in a flow-related manner without temporal change, we present cases with leakage of (/sup 99m/Tc)HM-PAO (filling out phenomenon) in the delayed image of brain single photon emission computed tomography (SPECT) and clarify its clinical significance. The filling out phenomenon was observed in seven out of 21 cases of cerebrovascular disease and four cases of arteriovenous malformation. The leakage of (/sup 99m/Tc)HM-PAO was also confirmed by visual and semiquantitative analysis. In the pharmacokinetics of (/sup 99m/Tc)HM-PAO in the blood, the percent dose of plasma fraction at 4 hr was reduced to 54% of activity at 30 min. The percent dose of brain blood could be predicted as 3.36%/1 at 30 min and 2.35%/1 at 4 hr after correction with the hematocrit of the brain. The filling out phenomenon of (/sup 99m/Tc)HM-PAO was attributed to a significant reduction of blood activity of (/sup 99m/Tc)HM-PAO in the plasma. Since the initial image might mask reduced rCBF with an increase of rCBV, the late image would have an advantage in accurately evaluating rCBF from the clearance of (/sup 99m/Tc) HM-PAO bound to the plasma. Therefore, the filling out phenomenon of (/sup 99m/Tc)HM-PAO in late images of brain SPECT could show the area of mild cerebral ischemia accompanying cerebral vascular reserve.
Sestamibi technetium-99m brain single-photon emission computed tomography to identify recurrent glioma in adults: 201 studies
Franńois Dubois; Serge Blond; Marc Steinling
Summary\\u000a ObjectĀĀIn the follow-up of treated gliomas, CT and MRI can often not differentiate radionecrosis from recurrent tumor. The aim of\\u000a this study was to assess the interest of functional imaging with 99mTc-MIBI SPECT in a large series of 201 examinations.\\u000a \\u000a \\u000a \\u000a MethodĀĀMIBI SPECT were performed in 81 patients treated for brain gliomas. A MIBI uptake index was computed as the
Thallium-201/technetium-99m-RP-30A disparity in the course of myocardial infarction after attempted reperfusion
Tatum, J.L.; Rehr, R.B.; DiSciascio, G.; Romhilt, D.W.; Fratkin, M.J.
Recent reports have established that /sup 201/Tl may be taken up in areas of recent myocardial infarction after myocardial blood flow is re-established. In addition, there is accelerated /sup 201/Tl washout from these regions producing a pattern of reverse redistribution. We present a case in which these phenomena may have contributed to a disparity of findings between a /sup 201/Tl stress imaging study and a repeat stress imaging study performed with a (/sup 99m/Tc) isonitrile (/sup 99m/Tc-RP-30A).
Uptake Mechanism of Technetium99m-d, 1- HMPAO in Cell Cultures of the Dissociated Postnatal Rat Cerebellum
Erhard Suess; Sigismund Huck; Hans Reither; Peter Angelberger
The accumulation and retention mechanisms of ~mTc-d,1- hexamethylpropyleneamine oxime (9~Tc-d,I-HMPAO) were investigated in cultures of the dissociated rat cerebellum. Our experiments indicate a linear dependency of the uptake on incubation time and on the concentration of the radioligand. Upon chloroform extraction and distribution between the li- pophilic and the hydrophilic phases, we located 69.1% of the retained radioactivity in the
Radionuclide imaging of the spleen with heat denatured technetium-99m RBC when the splenic reticuloendothelial system seems impaired
Owunwanne, A.; Halkar, R.; Al-Rasheed, A.; Abubacker, K.C.; Abdel-Dayem, H.
Imaging of the spleen of 10 patients who had been hematologically diagnosed with sickle-cell anemia (SCA) was studied with (/sup 99m/Tc)tin colloid and heat denatured (/sup 99m/Tc)RBCs. In all ten patients, there was faint or nonvisualization of the spleen with (/sup 99m/Tc)tin colloid. However, with heat denatured (/sup 99m/Tc)RBCs, nine spleens were well visualized, and the uptake was homogenous. One spleen had two patchy areas of uptake. The results indicate that when splenic phagocytic function is impaired as reflected by nonvisualization of the spleen with (/sup 99m/Tc)tin colloid, it is still possible to image such a spleen with heat denatured (/sup 99m/Tc)RBCs
Synthesis and Evaluation of Technetium-99m- and Rhenium-Labeled Inhibitors of the Prostate-Specific Membrane Antigen (PSMA)
Banerjee, Sangeeta R.; Foss, Catherine A.; Castanares, Mark; Mease, Ronnie C.; Byun, Youngjoo; Fox, James J.; Hilton, John; Lupold, Shawn E.; Kozikowski, Alan P.; Pomper, Martin G.
The prostate-specific membrane antigen (PSMA) is increasingly recognized as a viable target for imaging and therapy of cancer. We prepared seven 99mTc/Re-labeled compounds by attaching known Tc/Re chelating agents to an amino-functionalized PSMA inhibitor (lys-NHCONH-glu) with or without a variable length linker moiety. Ki values ranged from 0.17 to 199 nM. Ex vivo biodistribution and in vivo imaging demonstrated the degree of specific binding to engineered PSMA+ PC3 PIP tumors. PC3-PIP cells are derived from PC3 that have been transduced with the gene for PSMA. Despite demonstrating nearly the lowest PSMA inhibitory potency of this series, [99mTc(CO)3(L1)]+ (L1 = (2-pyridylmethyl)2N(CH2)4CH(CO2H)-NHCO-(CH2)6CO-NH-lys-NHCONH-glu) showed the highest, most selective PIP tumor uptake, at 7.9 ▒ 4.0% injected dose per gram of tissue at 30 min postinjection. Radioactivity cleared from nontarget tissues to produce a PIP to flu (PSMA-PC3) ratio of 44:1 at 120 min postinjection. PSMA can accommodate the steric requirements of 99mTc/Re complexes within PSMA inhibitors, the best results achieved with a linker moiety between the ? amine of the urea lysine and the chelator. PMID:18637669
Technetium-99m white blood cell imaging: False-negative result in salmonella osteomyelitis associated with sickle cell disease
Guze, B.H.; Hawkins, R.A.; Marcus, C.S.
The authors report a case of sickle cell anemia associated osteomyelitis where the Tc-99m white blood cell imaging was negative, and bone imaging showed increased uptake in the region in question. The reasons for the possible false-negative image are discussed.
Evaluation of extremity pain in children using technetium-99m MDP bone scan: A general hospital experience
Park, H.M.; Rothschild, P.A.; Kernek, C.B.
This study was undertaken to evaluate the efficacy of three-phase bone scan in detection of significant pathology i.e., osteomyelitis (OM), septic joint, cellulitis, etc., in children with symptoms of extremity pain. A total of 100 consecutive patients (age 9 days - 16 yrs, 63 boys and 37 girls) were studied. The authors reviewed their scans, x-rays and hospital records. The final diagnoses were based on the findings of needle aspiration, surgical drainage, biopsy, culture, and on the therapeutic response. In 87%, sufficiently long clinical follow-up was available to confirm the final diagnoses. In the remaining 13%, the symptoms resolved quickly and follow-up was not felt necessary. The scan was essential in pinpointing the lesions in pts with referred or nonlocalizing extremity pain. The +ve and -ve predictive values of the scan and OM were 89% and 96% respectively. One spiral fracture was misinterpreted as diffuse OM. One ''Subacute epiphyseal OM'' was not detected. In two cases, cellulitis and septic joint obscured underlying OM. Prior antibotic therapy resulted in one equivocal scan. Although less sensitive (29%) in early OM, radiographs play an important complimentary role. Bone scans detected underlying pathology for extremity pain in 61% of all pts studied.
Assessment of skin ulcer healing capability by technetium-99m phosphate angiogram and blood-pool images
Alazraki, N.; Dries, D.; Lawrence, P.; Morton, K.; Datz, F.; Taylor, A.
The accuracy of radionuclide angiography and blood-pool imaging using (/sup 99m/Tc)-phosphate to assess skin ulcer perfusion as an indicator of healing capacity was determined in 50 studies performed on 45 patients with nonhealing ulcers of the lower extremities. Two nuclear medicine physicians without clinical bias, graded the perfusion of the ulcer on the images as normal, increased or reduced with respect to the opposite limb. Patients were followed closely with aggressive local wound care for at least 14 days. Of the 31 ulcers which healed, the radionuclide study correctly predicted 30; of the 19 ulcers which did not heal, 14 were correctly predicted. Eight patients had osteomyelitis; four of those healed and four did not. The radionuclide study predicted healing in seven. This technique is a simple, reliable way to predict the microcirculatory adequacy for ulcer healing. Specificity is diminished in the presence of osteomyelitis.
In vivo kinetics of canine leukocytes labeled with technetium-99m HM-PAO and indium-111 tropolonate
Mock, B.H.; Schauwecker, D.S.; English, D.; Young, K.A.; Wellman, H.N.
Two weeks after the introduction of osteomyelitis in three dogs, autologous leukocytes were dual-labeled with both (/sup 99m/Tc)HM-PAO and (/sup 111/In)tropolonate, and reinjected. Blood sampling and imaging were then performed. Two weeks later, the same dogs received simultaneous injections of singly-labeled (/sup 99m/Tc)WBC and (/sup 111/In)WBC for comparison. For both studies, blood samples were drawn over 6 hr to determine the respective blood clearance half-time (TB) and % recovery (%R0) of cell-bound radioactivity. There were no significant differences in the average TB results of the /sup 99m/Tc and /sup 111/In groups, either within or between the dual- and singly-labeled studies. The %R0 of singly-labeled (/sup 99m/Tc)WBC was about half that of the other groups (p less than 0.01); however, this difference was attributed to the dissimilar radiochemical purity of the (/sup 99m/Tc)HM-PAO reagents. Region of interest analysis of the 6 and 24 hr images revealed no significant differences between either cell label in the relative or absolute in vivo uptake at known sites of osteomyelitis, noninfected surgery, and normal bone marrow.
Molybdenum-99 production from reactor irradiation of molybdenum targets: a viable strategy for enhanced availability of technetium-99m.
Pillai, M R A; Knapp, F F Russ
Fission-produced 99Mo (F 99Mo) is traditionally used for fabrication of 99Mo/99mTc alumina-based column generators. In this paper, several emerging strategies are discussed which are being pursued or have been suggested to overcome the continuing shortages of F 99Mo. In addition to the hopeful eventual success of these proposed new 99Mo and 99mTc production technologies, an additional attractive strategy is the alternative production and use of low specific activity (LSA) 99Mo. This strategy avoids fission and is accomplished by direct activation of molybdenum targets in nuclear reactors, which would preclude sole continued reliance on F 99Mo. The principal focus of this paper is a detailed discussion on the advantages and strategies for enhanced production of LSA 99Mo using an international network of research reactors. Several effective strategies are discussed to obtain 99mTc from LSA 99Mo as well as more efficient use of the alumina-based generator system. The delayed time period between 99Mo production and traditional 99Mo/99mTc alumina column generator manufacture and distribution to user sites results in the loss of more than 50% of 99Mo activity. Another strategy is a paradigm shift in the use of 99Mo by recovering clinical-grade 99mTc from 99Mo solution as an alternative to use of 99Mo/99mTc column generators, thereby avoiding substantial decreased availability of 99Mo from radioactive decay. Implementation of the suggested strategies would be expected to increase availability of 99mTc to the clinical user community by several fold. Additional important advantages for the use of LSA 99Mo include eliminating the need for fission product waste management and precluding proliferation concerns by phasing out the need for high (HEU)- and low (LEU)-enriched uranium targets required for F 99Mo production. PMID:23013668
Directly and indirectly technetium-99m-labeled antibodies--a comparison of in vitro and animal in vivo properties.
Hnatowich, D J; Mardirossian, G; Rusckowski, M; Fogarasi, M; Virzi, F; Winnard, P
To investigate the in vivo and in vitro properties of 99mTc when labeled to antibodies via one direct and one indirect method, the B72.3 and C110 IgG antibodies were radiolabeled directly via stannous ion reduction and indirectly via the hydrazino nicotinamide chelator and compared in vitro and in vivo. Antibody avidity (but not immunoreactive fraction) appeared to be independent of labeling methods for both antibodies. Following stannous ion reduction, antibodies were fragmented by denaturing SDS PAGE although only slight evidence of fragmentation was found in vivo. The direct label was instable to transchelation to cysteine and glutathione in vitro and in vivo. Following intravenous administration, urinary excretion of activity was threefold greater for the direct label and was almost exclusively labeled cysteine and glutathione. Significant differences in the biodistribution of 99mTc were also observed: liver levels were lower, kidney levels were higher and clearance of label from blood and tissues was faster for the direct label. At Day 1, tumor accumulation was threefold lower for the direct label although most normal tissues were also lower. In conclusion, when labeled to two antibodies by one direct method, 99mTc is unstable towards transchelation relative to one indirect method. These relative instabilities greatly influenced the biodistributions in mice and may influence the quality of images obtained in patients. PMID:8418250
Technetium-99m antibodies labeled with MAG3 and SHNH: an in vitro and animal in vivo comparison.
Lei, K; Rusckowski, M; Chang, F; Qu, T; Mardirossian, G; Hnatowich, D J
The in vitro stability and animal pharmacokinetics of 99mTc bound to Sandoz and C110 IgG antibodies via a modified MAG3 has been compared with the hydrazino nicotinamide (SHNH) moiety as standard. For both antibodies, the stabilities of the label to challenge at up to 50:1 cysteine: IgG molar ratio were comparable, but at higher molar ratios, MAG3 showed greater instabilities. For the Sandoz antibody, size-exclusion HPLC analysis of 37 degrees C serum incubates and plasma samples from injected mice showed no clearly distinguishable differences. In the C110 case, some increased high molecular weight radioactivity was apparent with MAG3. Biodistributions in normal mice showed significant differences only in liver (Sandoz) and liver, spleen, intestines, stomach, and blood (C110), with SHNH usually providing higher levels. Thus, for two different antibodies and under the conditions of this study, the MAG3 chelator provided a 99mTc label with properties similar to that of SHNH moiety. PMID:8971860
Orally administered DTPA penta-ethyl ester for the decorporation of inhaled 241Am
Sueda, Katsuhiko; Sadgrove, Matthew P.; Huckle, James E.; Leed, Marina G. D.; Weber, Waylon M.; Doyle-Eisele, Melanie; Guilmette, Raymond A.; Jay, Michael
Diethylenetriaminepentaacetic acid (DTPA) is an effective decorporation agent to facilitate the elimination of radionuclides from the body, but its permeability-limited oral bioavailability limits its utility in mass-casualty emergencies. To overcome this limitation, a prodrug strategy using the penta-ethyl ester form of DTPA is under investigation. Pharmacokinetic and biodistribution studies were conducted in rats by orally administering [14C]DTPA penta-ethyl ester, and this prodrug and its hydrolysis products were analyzed as a single entity. Compared to a previous reporting of intravenously administered DTPA, the oral administration of this prodrug resulted in a sustained plasma concentration profile with higher plasma exposure and lower clearance. An assessment of the urine composition revealed that the bioactivation was extensive but incomplete, with no detectable levels of the penta- or tetra-ester forms. Tissue distribution at 12 h was limited, with approximately 73% of the administered dose being associated with the gastrointestinal tract. In the efficacy study, rats were exposed to aerosols of 241Am nitrate before receiving a single oral treatment of the prodrug. The urinary excretion of 241Am was found to be 19% higher than with the control. Consistent with prior reports of DTPA, the prodrug was most effective when the treatment delays were minimized. PMID:24619514
Orally administered DTPA penta-ethyl ester for the decorporation of inhaled (241)Am.
Sueda, Katsuhiko; Sadgrove, Matthew P; Huckle, James E; Leed, Marina G D; Weber, Waylon M; Doyle-Eisele, Melanie; Guilmette, Raymond A; Jay, Michael
Diethylenetriaminepentaacetic acid (DTPA) is an effective decorporation agent to facilitate the elimination of radionuclides from the body, but its permeability-limited oral bioavailability limits its utility in mass-casualty emergencies. To overcome this limitation, a prodrug strategy using the penta-ethyl ester form of DTPA is under investigation. Pharmacokinetic and biodistribution studies were conducted in rats by orally administering [(14) C]DTPA penta-ethyl ester, and this prodrug and its hydrolysis products were analyzed as a single entity. Compared with a previous reporting of intravenously administered DTPA, the oral administration of this prodrug resulted in a sustained plasma concentration profile with higher plasma exposure and lower clearance. An assessment of the urine composition revealed that the bioactivation was extensive but incomplete, with no detectable levels of the penta- or tetra-ester forms. Tissue distribution at 12 h was limited, with approximately 73% of the administered dose being associated with the gastrointestinal tract. In the efficacy study, rats were exposed to aerosols of (241) Am nitrate before receiving a single oral treatment of the prodrug. The urinary excretion of (241) Am was found to be 19% higher than with the control. Consistent with prior reports of DTPA, the prodrug was most effective when the treatment delays were minimized. PMID:24619514
Influence of chest background on pulmonary [sup 99m][Tc]-DTPA clearance in interstitial lung disease
Ishizaka, Akitoshi; Kanazawa, Minoru; Suzuki, Yukio; Hasegawa, Naoki; Kubo, Atsushi; Kawashiro, Takeo (Keio Univ., Tokyo (Japan))
The authors examined the effect of chest extracellular [sup 99m][Tc]-diethylenetriamine pentaacetate (DTPA) as a background in the measurement of pulmonary [sup 99m][Tc]-DTPA clearance in patients with interstitial lung disease (ILD). Eight healthy nonsmokers (HN) and eight patients with ILD were studied. They monitored changes in gamma counts after the inhalation of [sup 99m][Tc]-DTPA aerosol by using a gamma camera placed over the anterior chest. The rate constant of pulmonary [sup 99m][Tc]-DTPA clearance (k; %/min) was assessed by calculating the slope of the decrease in the gamma counts. The chest background, estimated by [sup 99m][Tc]-DTPA intravenous injection, was subtracted from the original data to obtain the corrected DTPA clearance (k[sub c]; %/min). In patients with ILD, k was significantly greater [2.19 [+-] 1.03 (SD) %/min; n = 8] compared with HN (0.86 [+-] 0.17%/min; n = 8; P < 0.01). In patients with ILD, k[sub c] was also greater (2.80 [+-] 1.15%/min; n = 8; P < 0.01) compared with HN (1.20 [+-] 0.12%/min; n = 8). There was no difference in percent underestimation of k between the two groups (29.1 [+-] 8.8% for HN, 22.5 [+-] 7.9% for patients with ILD). There was a significant correlation between k and k[sub c] among all subjects (r = 0.987, P < 0.01). They conclude that background causes significant underestimation of pulmonary [sup 99m][Tc]-DTPA clearance. 16 refs., 2 figs., 2 tabs.
The CONRAD approach to biokinetic modeling of DTPA decorporation therapy.
Breustedt, Bastian; Blanchardon, Eric; Bķrard, Philippe; Fritsch, Paul; Giussani, Augusto; Lopez, Maria Antonia; Luciani, Andrea; Nosske, Dietmar; Piechowski, Jean; Schimmelpfeng, Jutta; Sķrandour, Anne-Laure
Diethylene Triamine Pentaacetic Acid (DTPA) is used for decorporation of plutonium because it is known to be able to enhance its urinary excretion for several days after treatment by forming stable Pu-DTPA complexes. The decorporation prevents accumulation in organs and results in a dosimetric benefit, which is difficult to quantify from bioassay data using existing models. The development of a biokinetic model describing the mechanisms of actinide decorporation by administration of DTPA was initiated as a task in the European COordinated Network on RAdiation Dosimetry (CONRAD). The systemic biokinetic model from Leggett et al. and the biokinetic model for DTPA compounds of International Commission on Radiological Protection Publication 53 were the starting points. A new model for biokinetics of administered DTPA based on physiological interpretation of 14C-labeled DTPA studies from literature was proposed by the group. Plutonium and DTPA biokinetics were modeled separately. The systems were connected by means of a second order kinetics process describing the chelation process of plutonium atoms and DTPA molecules to Pu-DTPA complexes. It was assumed that chelation only occurs in the blood and in systemic compartment ST0 (representing rapid turnover soft tissues), and that Pu-DTPA complexes and administered forms of DTPA share the same biokinetic behavior. First applications of the CONRAD approach showed that the enhancement of plutonium urinary excretion after administration of DTPA was strongly influenced by the chelation rate constant. Setting it to a high value resulted in a good fit to the observed data. However, the model was not yet satisfactory since the effects of repeated DTPA administration in a short time period cannot be predicted in a realistic way. In order to introduce more physiological knowledge into the model several questions still have to be answered. Further detailed studies of human contamination cases and experimental data will be needed in order to address these issues. The work is now continued within the European Radiation Dosimetry Group, EURADOS. PMID:20838097
Characterization of DTPA complexes and conjugated antibodies of astatine
S. Milesz; Yu. V. Norseev; Z. Sz³cs; L. Vasßros
The complex formation of astatine\\/I\\/ cation with diethylene triamine pentaacetic acid \\/DTPA\\/ and characterization of the complexes were investigated by electromigration in free electrolytes and by gel-chromatography on Sephadex G 25. We describe the conjugation procedure for the production of At-DTPA conjugated polyclonal antibodies.
Technetium99m-HMPAOSPECT, CT and MRI in the Evaluation of Patients with Chronic TraumaticBrain Injury:A Correlationwith Neuropsychological Performance
Masanon Ichise; Dae-Gyun Chung; Paul Wang; George Wortzman; Bruce G. Gray; William Franks
The purposes of thisstudywere:(1) to compare @ŌĆ£Tc-hexa methylpropyleneamineodrne (HMPAO) SPECTwith CT and MRIinchronic traumatic braininjury(TBI)patients and(2)to correlatebothfunctionaland structuralnsurolmagingmeasure ments of brain damage with neuropsychologlcal (NP) perfor mance.Methods: Twenty-ninepatients(minorTBI, n = 15 and major TBI, n = 14) and 17 normal controls (NC) underwent HMPAO SPECT, CT,MRIandNPtesting. Imaging datawere analyzedbothvisuallyand quantitatively. Results:Nineteen (66%)patientsshowed42 abnormalities on SPECTimages, whereas 13 (45%)and 10 (34%)patientsshowed29
Nearly total absence of pulmonary perfusion with corresponding technetium-99m MDP and gallium-67 uptake in a patient with mediastinal neuroblastoma
Garty, I.; Koren, A.; Moguilner, G.; Dharan, M.; Siplovitch, L.
A case of unilateral nearly total hypoperfusion of the left lung in a 13-month-old girl is presented. The combination of the lung hypoperfusion and accumulation of the Tc-99m MDP and Ga-67 citrate in the same area suggested the preoperative diagnosis of mediastinal neuroblastoma. Explorative thoracotomy revealed the presence of a neuroblastoma compressing the left lung pedicle. The described scintigraphic appearance in the pediatric age group is suggested as typical of mediastinal neuroblastoma. This pathology should be included in the following gamuts in nuclear medicine: unilateral decrease or absent lung perfusion, unilateral diffuse chest uptake of Ga-67 citrate, and unilateral pulmonary uptake in bone scintigraphy.
Hybrid Single-Photon Emission Computed Tomography/Computed Tomography Imaging Features of Tumoral Calcinosis in Technetium-99m Methylene Diphosphonate Bone Scintigraphy.
Kamaleshwaran, Koramadai Karuppusamy; Asokumar, Premkumar; Malaikkal, Anjali; Mohanan, Vyshakh; Shinto, Ajit Sugunan
Tumoral calcinosis (TC) is an uncommon ectopic calcification syndrome. TC is a benign condition characterized by the presence of large calcific soft tissue deposits occurring predominantly in a periarticular location. It generally occurs as a complication of renal dialysis or trauma, and is rarely seen in familial and sporadic cases. Bone scintigraphy is a sensitive method for diagnosing TC. We report a case of year old female with. She underwent bone scintigraphy to see the sites of involvement, which showed intense foci of tracer activity in soft tissue in bilateral thigh and gluteal region. Hybrid single-photon emission computed tomography/computed tomography of the pelvis and thigh localized tracer uptake to the calcification in the gluteal and thigh region. PMID:26097427
Abnormal lung and liver uptake of gallium-67 and technetium-99m MDP in hypercalcemia of lymphoma with metastatic pulmonary calcification
Sullivan, W.T.; Orzel, J.A.; Reed, K.D.; Bower, J.H.
Abnormal pulmonary uptake of Ga-67 citrate and Tc-99m MDP and reversible liver uptake of Tc-99m MDP was seen in a patient with hypercalcemia of lymphoma and biopsy-proven metastatic pulmonary calcification. Abnormal lung uptake of Tc-99m MDP may confirm the diagnosis of pulmonary calcification, lessening the need for invasive procedures to evaluate pathologic lung uptake of Ga-67 citrate.
Radioimmunoscintigraphy using Technetium99m-labeled parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen in athymic nude mice bearing tumor
Yoshiharu Karube; Kentaro Katsuno; Jiro Takata; Kazuhisa Matsunaga; Masatora Haruno; Masahide Kuroki; Fumiko Arakawa; Yuji Matsuoka; Hidetoshi Kanda
Biodistribution and imaging characteristics of Tc-99m-labeled parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen (CEA), designated F11-39 and ChF11-39, respectively, were evaluated in athymic nude mice bearing the human CEA-producing gastric carcinoma (MKN-45) xenografts. Group F monoclonal antibodies such as F11-39 and ChF11-39 have been found to recognize the protein epitopes present on the domain B3 of the CEA
Perfusion impairments in infantile autism on technetium-99m ethyl cysteinate dimer brain single-photon emission tomography: comparison with findings on magnetic resonance imaging
Young Hoon Ryu; Jong Doo Lee; Pyeong Ho Yoon; Dong Ik Kim; Ho Bun Lee; Yee Jin Shin
.ĀĀ The neuro-anatomical substrate of autism has been the subject of detailed investigation. Because previous studies have not\\u000a demonstrated consistent and specific neuro-imaging findings in autism and most such studies have been performed in adults\\u000a and school-aged children, we performed a retrospective review in young children in search of common functional and anatomical\\u000a abnormalities with brain single-photon emission tomography (SPET)
Fetal dose estimates and the ICRP abdominal dose limit for occupational exposure of pregnant staff to technetium-99m and iodine-131 patients
P. J. Mountford; H. R. Steele
The International Commission on Radiological Protection has recently recommended a supplementary dose limit of 2 mSv to the abdominal surface of a pregnant member of staff in order to provide protection to her fetus comparable to that in members of the public, whose annual limit is recommended to be 1 mSv. In order to determine whether this apparent attenuation factor
Uptake of technetium-99m methylene diphosphonate by fractured and osteoporotic bone after a pulse dose of Vitamin D/sub 3/. [Rats
Carr, E.A. Jr.; Carroll, M.; Montes, M.; Zielezny, M.
The effect of a pulse dose of Vitamin D/sub 3/ on uptake of (/sup 99m/Tc)MDP by fractured and osteoporotic bone, respectively, was compared with D/sub 3/'s effect on uptake by normal bone in rats. At 4, 7, and 14 days, respectively, after femoral fracture, basal uptake was significantly increased at the fracture site by 336.8, 276.1, and 183.5%, respectively, over the contralateral control site. D/sub 3/-treated rats had lower uptakes than untreated controls at all three fracture sites and at 12 of 15 normal bone sites but analysis of variance showed the uptake differences were not significant. Cortisone-induced osteoporosis caused a significant decrease in basal uptake. The decrease occurred in all nine bone areas studied. D/sub 3/ caused a significant increase in uptake by these osteoporotic bones, but a significant decrease in uptake by the same bones in normal controls. Thus, D/sub 3/ had an effect on uptake by the bone lesion, osteoporosis, that differed from D/sub 3/'s effect on uptake by fracture or normal bone.
Development of the Plutonium-DTPA Biokinetic Model.
Konzen, Kevin; Brey, Richard
Estimating radionuclide intakes from bioassays following chelation treatment presents a challenge to the dosimetrist due to the observed excretion enhancement of the particular radionuclide of concern where no standard biokinetic model exists. This document provides a Pu-DTPA biokinetic model that may be used for making such determination for plutonium intakes. The Pu-DTPA biokinetic model is intended to supplement the standard recommended biokinetic models. The model was used to evaluate several chelation strategies that resulted in providing recommendations for effective treatment. These recommendations supported early treatment for soluble particle inhalations and an initial 3-day series of DTPA treatments for wounds. Several late chelation strategies were also compared where reduced treatment frequencies proved to be as effective as multiple treatments. The Pu-DTPA biokinetic model can be used to assist in estimating initial intakes of transuranic radionuclides and for studying the effects of different treatment strategies. PMID:25905517
Clinical comparison of a new Tc-99m DTPA delivery system with Kr-81m
Finn, J.P.; Myers, M.J.; Nair, K.M.; Lavender, J.P.
Satisfactory agents for ventilation imaging are not widely available. Access to Kr-81m is limited and image quality with Xe-133 is poor, so attention is being focused on radioaerosols as possible alternatives. The authors assessed the diagnostic value of a new Tc-99m DTPA aerosol delivery system. Forty patients were studied, most with suspected pulmonary embolism. The protocol involved FEV/sub 1/ measurement, six minutes aerosol inhalation immediately followed by steady-state Kr-81m imaging and, 60 minutes later, by Tc-99m MAA perfusion imaging. The efficiency of the system was 2%. Twenty-one patients had no central airways deposition of aerosol, 14 had 'spotty' images which were correctly interpretable and five had airways deposition sufficient to be misleading. The overall sensitivity of the test relative to Kr-81m was 75% and the specificity 84% (100% and 94% respectively among non-smokers). Airways deposition was significantly more frequent in smokers than in non-smokers and in patients whose FEV/sub 1/ was less than 50% predicted. The authors conclude that the system provides accurate clinical information in non-smokers but is of less value in smokers. It should prove a practical alternative to Xe-133.
Pseudolayering of Gd-DTPA in the urinary bladder.
Elster, A D; Sobol, W T; Hinson, W H
When excreted gadolinium diethylenetriaminepentaacetic acid (DTPA) collects in the bladder of a supine patient during magnetic resonance (MR) imaging, a puzzling pattern of signal intensities is noted. A gradual change in urine signal intensity with progressive addition of Gd-DTPA does not occur; instead, three sharply defined "layers" are seen both on T1- and T2-weighted images within the urine-Gd-DTPA mixture. The physical basis for this triple-layering phenomenon was investigated. A bladder phantom was constructed to reproduce the phenomenon. T1 and T2 relaxivities of urine doped with varying concentrations of Gd-DTPA were measured in vitro; measured signal intensities corresponded closely to predicted intensities. Early urine concentrations of excreted Gd-DTPA may be relatively high (10-40 mmol/L), resulting in extremely short T1 and T2 values (less than 30 msec). These extremely short relaxation times cause an artifactual pseudolayering of signal within the urine-Gd-DTPA mixture. PMID:2296649
Elimination of gadolinium-DTPA by peritoneal dialysis.
D÷rsam, J; Knopp, M V; Schad, L; Piesche, S; Carl, S; Oesingmann, N
Magnetic resonance urography (MRU) after i.v. injection of gadolinium-DTPA (0.1 mmol/kg bodyweight) was performed in a patient with transplant dysfunction after renal allograft transplantation. Renal replacement therapy was accomplished by means of peritoneal dialysis. Gadolinium-DTPA concentrations in urine and dialysate were measured repeatedly during a 48-h period with inductively coupled plasma atomic emission spectrometry. The total 24-h creatinine clearance was 10.8 ml/min on day 1 and 13.7 ml/min on day 2. The corresponding total gadolinium clearance was 12.8 ml/min and 15.8 ml/min respectively. Gadolinium-DTPA was removed from the body through peritoneal dialysis at a mean clearance rate of 5.13 ml/min. Plasma half-life of gadolinium-DTPA was prolonged to 9 h. No side-effects due to gadolinium-DTPA were noted. MRU provided a better visualization of the morphology of the urinary tract than scintigraphic studies. By measuring the changes of signal intensity, the gadolinium excretion could be calculated. PMID:7478129
James, Anthony C.; Sasser , Lyle B.; Stuit, Dorothy B.; Glover, Samuel E.; Carbaugh, Eugene H.
This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol æmist.Æ Chelation treatment with i.v. Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2Į years with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation), and continuing for 37 years. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 years after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive dataset has been applied to derive æchelation-enhancedÆ transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys, and 50% for the skeleton. Essentially all of the substantial reduction in skeletal burden occurred in trabecular bone. This modeling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as effective as promptly administered Ca-EDTA.
Ustur whole body case 0269: demonstrating effectiveness of i.v. CA-DTPA for Pu.
James, A C; Sasser, L B; Stuit, D B; Glover, S E; Carbaugh, E H
This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol 'mist'. Chelation treatment with intravenously (i.v.) Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2.5 y with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation) and continuing for 37 y. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 y after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive data set has been applied to derive 'chelation-enhanced' transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys and 50% for the skeleton. Essentially, all of the substantial reduction in skeletal burden occurred in trabecular bone. This modelling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as effective as promptly administered Ca-EDTA. PMID:18227077
Asymptomatic renal abscess: Evaluation with gadolinium DTPA-enhanced MRI
K. M. Cyran; P. J. Kenney
Incidental detection of renal mass in a transplant patient is a diagnostic challenge. These patients are at risk for the development of neoplasms and, more commonly, infection with atypical organisms. Symptomatology may be lacking in either, and both conditions may present with similar symptoms. Magnetic resonance imaging (MRI) evaluation with gadolinium DTPA is helpful in the evaluation of asymptomatic renal
Gemcitabine aerosol: in vitro antitumor activity and deposition imaging for preclinical safety assessment in baboons
Frķdķric Gagnadoux; Valķrie Leblond; Laurent Vecellio; Josķ Hureaux; Alain Le Pape; MichĶle Boisdron-Celle; Jķrome Montharu; Caroline Majoral; Joseph Fournier; Thierry Urban; Patrice Diot; Jean-Louis Racineux; Etienne Lemariķ
Aim: To characterize gemcitabine aerosol, its in vitro activity against lung cancer cells, its deposition, and tolerance in a non-human primate model. Methods: In vitro cytotoxicity of nebulized gemcitabine against NCI-H460 and A549 lung cancer cells was tested using a growth inhibition assay and compared with non-nebulized gemcitabine. The 99mTc-DTPA-radiolabeled gemcitabine aerosol was characterized by cascade impaction and the gemcitabine
Determination of the MRI contrast agent Gd-DTPA by SEC-ICP-MS.
Loreti, Valeria; Bettmer, J÷rg
The simultaneous determination of Gd(3+) and Gd-DTPA (DTPA: diethylenetriamino-pentaacetic acid), often used as contrast agent, is described. The proposed approach combines size-exclusion chromatography (SEC) and inductively coupled plasma-mass spectrometry (ICP-MS) for element-selective detection in order to determine also high-molecular Gd-complexes if present. This method was applied to the analysis of urine samples of a patient to whom Gd-DTPA was intravenously administered. The results showed that no conversion or adsorption of Gd-DTPA could be observed in any sample, even free Gd(3+) could not be detected. Urine excretion behaviour was monitored and it was proved that Gd-DTPA was almost completely (>99%) excreted by urination within one day. Traces of Gd-DTPA could be measured in hair samples, but extraction with tetramethylammonium hydroxide (TMAH) resulted in degradation of Gd-DTPA. PMID:15235758
Synthesis, DTPA coupling and radio labeling of cationic aminodextran
Subramanian, G.; McAfee, J.G.; Schneider, R.F.; Zapf-Longo, C.; Palladino, E.; Lyons, B.J.; Roskopf, M.
In glomerular diseases, the normal anionic charge of the basement membrane is lost at an early stage. Glomerular damage in rats has been detected more readily with cationic dextrans than with inulin. Hence, the authors attempted to demonstrate this phenomenon in vivo in rats with labeled cationic dextran. Aminated Dextran (AMDEX) was prepared by treating Dextran(mol. wt approx. = 15k) with sodium methoxide followed by a bromethylamine HBr in DMSO resulting in 10-25 aminogroups per mole. DTPA cyclic dianhydride was coupled to AMDEX using a weight ratio of 1:10 in 0.2 - 1.0 ml 0.42 M Hepes buffer at pH 7.4. Free DTPA was removed by gel filtration (Sephadex P6DG) or by using Centricon-10 (AMICON) centrifugal microconcentrators. AMDEX coupled with DTPA was labeled with Indium-111 in 0.25 M acetate buffer. Labeling yields were >90% by gel chromatography and electrophoresis (pH8.2 Barbitol buffer). AMEXDTPA was labeled also by ligand exchange with Tc-99m-Sn-citrate at neutral pH with a labeling yield of 30%. On electrophoresis, all the labeled samples retained their cationic character. The distribution of purified In-111 AMDEX, was compared with simultaneously IV injected Tc-99m DTPA in rats. The 2 hour urinary excretion, and renal clearance (calculated from the biexponential plasma clearance) were slower (70 to 80%) than those of DTPA, due to the larger molecular size of AMDEX. By 1 hr., 5% of the administered activity was retained in each kidney, probably due to adherence to anionic binding sites.
Captopril renography in the diagnosis of renal artery stenosis: Accuracy and limitations
Samuel J. Mann; Thomas G. Pickering; Thomas A. Sos; Robert G. Uzzo; Salil Sarkar; Katherine Friend; Marlene E. Rackson; John H. Laragh
The purpose of this study was to determine the sensitivity, specificity, and clinical usefulness of renography performed in combination with captopril administration (captopril renography) in diagnosing renal artery stenosis. Fifty-five patients with suspected renal artery stenosis underwent renography prior to performance of renal angiography. Renography was performed on two consecutive days using technetium-99m-diethylenetiamine pentaacetic acid (DTPA) as an index of
Species-dependent effective concentration of DTPA in plasma for chelation of 241Am
Sueda, Katsuhiko; Sadgrove, Matthew P.; Jay, Michael; Di Pasqua, Anthony J.
Diethylenetriaminepentaacetic acid (DTPA) is a chelating agent that is used to facilitate the elimination of radionuclides, such as americium, from contaminated individuals. Its primary site of action is in the blood, where it competes with various biological ligands, including transferrin and albumin, for the binding of radioactive metals. To evaluate the chelation potential of DTPA under these conditions, the competitive binding of 241Am between DTPA and plasma proteins was studied in rat, beagle and human plasma in vitro. Following incubation of DTPA and 241Am in plasma, the 241Am-bound ligands were fractionated by ultrafiltration and ion-exchange chromatography, and each fraction was assayed for 241Am content by gamma scintillation counting. Dose-response curves of DTPA for 241Am binding were established, and these models were used to calculate the 90% maximal effective concentration, or EC90, of DTPA in each plasma system. The EC90 were determined to be 31.4, 15.9 and 10.0 ?M in rat, beagle and human plasma, respectively. These values correspond to plasma concentrations of DTPA that maximize 241Am chelation while minimizing excess DTPA. Based on the pharmacokinetic profile of DTPA in humans, after a standard 30 ?mol kg?1 intravenous bolus injection, the plasma concentration of DTPA remains above EC90 for approximately 5.6 h. Likewise, the effective duration of DTPA in rat and beagle were determined to be 0.67 and 1.7 h, respectively. These results suggest that species differences must be considered when translating DTPA efficacy data from animals to humans and offer further insights into improving the current DTPA treatment regimen. PMID:23799506
Gd-DTPA-enhanced MR in thoracic disc herniations
P. M. Parizel; G. Rodesch; D. Balķriaux; D. Zegers de Beyl; J. D'Haens; J. Noterman; C. Segebarth
The Gd-DTPA-enhanced magnetic resonance findings in two patients with herniated thoracic intervertebral discs are reported. The first patient was a 56-year-old woman with a small subligamentous T6-7 disc herniation, slightly lateralized to the right. The second patient was a 51-year-old man with a central and right posterolateral disc herniation, including a large calcified fragment, at the T8-9 level. The nonenhanced
Label stability in serum of four radionuclides on DTPA-coupled antibodies--an evaluation.
Hnatowich, D J
Although DTPA forms strong chelates with many metals, the harsh chemical environment of the serum may nevertheless dissociate metallic radionuclides from DTPA attached to proteins. We have investigated the stability in 37 degrees C serum of 111In, 99mTc, 90Y and 153Gd chelated to DTPA-coupled antibodies. Stability was evaluated primarily by affinity chromatography and HPLC analysis of serum incubates; however, the stability of 111In was determined in vivo in patient studies. Analysis of patient urine showed no evidence for dissociation of DTPA from antibody whereas analysis of serum demonstrated exchange rates of 111In to transferrin of about 9%/day. When labeled by the described method, 99mTc on DTPA coupled antibodies shows instability in serum but superior stability than 99mTc on antibodies without the attached DTPA. Both 90Y and 153Gd dissociate in serum at rates which are comparable to that of 111In. PMID:3793489
Preparation and premilinary evaluation of astatine-211 labeled IgG via DTPA anhydride
Liu Ning; Jin Jiannan; Mo Shangwu; Chen Hengliu; Yu Yanping
A method for211At labeling of human IgG via DTPA anhydride is described. DTPA-IgD was prepared and211At was conjugated to human IgG by adding Na211At to the DTPA-IgG and reaction for 30 minutes at room temperature. The astatinated IgG was isolated by a Sephadex G50 column and identified by size exclusion HPLC. The labeling procedure was executed in 1.5 hours and
Dynamic MR imaging of kidneys perfused with EOB-Gd-DTPA.
Hyodoh, Kazusa; Hyodoh, Hideki; Kasahara, Michiko; Washio, Yoshikazu; Asai, Mayumi; Hareyama, Masato
Gandolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) is a hepatobiliary contrast agent for MRI. It was reported that Gd-EOB-DTPA is useful to detect liver tumors and differentially diagnose benign and malignant pathologies in the liver. Since Gd-EOB-DTPA partially accumulates in the hepatocytes and bile via various transporters after intravenous injection, signal intensity in the liver increases on T1-weighted images. The signal intensity of the liver after Gd-EOB-DTPA injection depends on the Gd-EOB-DTPA uptake by hepatocytes and bile excretion. It is known tha the Gd-EOB-DTPA accumulating in the kidney is excreted to the urine through glomerular filtration. Because Gd-DTPA is concentrated in the renal tubules after being filtered at the Bowman's capsule, and since it is neither secreted nor reabsorbed the concentrating and diluting function of the renal tubules can be studied by imaging techniques. since renal function can be evaluated with Gd-EOB-DTPA can also be used to evaluate renal function. Eith the development of MRI equipment and rapid imaging techniques, temporal resolution had improved greatly. However, no previous study has been carried out on renal function using Gd-EOB-DTPA dynamic MR study that was correlated with estimated glomerular filtration rate (eGFR) and stage of chronic kidney disease (CKD) in the Japan Association of chronic kidney disease initiative. PMID:21630549
Influence of posture and positive end-tidal expiratory pressure (PEEP) on clearance of Tc99m-DTPA from the lungs
Mason, G.R.; Maublant, J.; Sietsema, K.; Effros, R.M.; Mena, I.
The clearance of Tc99m-DTPA aerosols from the lung has been used to detect and quantitate alterations in the permeability of the pulmonary epithelium. Clearance of the radionuclide is accelerated by both chronic and acute injuries to the lung and by smoking. Several laboratories have reported that Tc99m-DTPA clearance from upper lobes exceeded that from lower lobes in upright subjects. To investigate this phenomenon further the authors studied subjects with simultaneous anterior and posterior cameras in upright and supine positions. In the upright position, clearance from both the anterior and posterior upper regions of interest (ROI's) exceeded the lower regions (-1.64 +- .42 S.D. vs. -0.75 +- .41, anterior, p < .05, n=6), -1.04 +- .23 vs. -0.50 +- .36, posterior. All units = %/min. This difference was not observed in the supine subjects. Clearance from the anterior chest exceeded that from the posterior chest in the supine subjects (-1.28 +- .45 vs. -0.05 +- 1.08) and a small increase in radio-activity was observed in at least one ROI of 5 of 6 subjects from the posterior camera. An increase in activity is likely to be secondary to labeling of blood pool, which would have greatest affect where pulmonary blood volume is largest. Computer processing of the entire lung without observer bias in ROI placement showed similar effects of posture over non-peripheral ROI's. Five subjects breathed on PEEP to cause airspace distention, causing clearance to double. Both dependency and airspace distention appear to influence clearance of aerosolized DTPA, the latter may occur by stretching of epithelial pores.
Pulmonary deposition and clearance measurements of aerosolized radiopharmaceuticals in the sedated dogĀ
Merton, Dawn Ann
tion of TcMAA in dog 2. Images produced by aerosolization of Tc04 in 23 99m dog 3. Images produced by aerosolization of Tc-DTPA. . . . . . . 25 in dog 2. Images produced by aerosolization of Tc-DIVA. . . . . . . . 27 ln dog 3. Time-activity curve... albumin ( Tc-MAA, 1-3 mCi) intravenously. The lungs were immediately imaged with a scintillation camera with the camera oriented at a 90 angle to the table. Eight. views were recorded on film. A ventral view was taken first; the animal was placed...
Pulmonary clearance of radiotracers after positive end-expiratory pressure or acute lung injury
Barrowcliffe, M.P.; Zanelli, G.D.; Jones, J.G.
In anesthetized rabbits we measured clearance from lung to blood of eight aerosolized technetium-99m-labeled compounds: diethylenetriaminepentaacetate (99mTc-DTPA); cytochrome c; myoglobin; a myoglobin polymer; albumin; and anionic, cationic, and neutral dextrans of equivalent molecular size. We investigated the effect of applying positive end-expiratory pressure (PEEP) and, on a subsequent occasion, of injecting oleic acid intravenously to produce acute lung injury on the pulmonary clearance rate. Base-line clearance rates were monoexponential and varied with the molecular weights of the radiotracers. For each tracer the rate of clearance was increased a similar degree by either PEEP or oleic acid. However, with PEEP, clearance remained monoexponential, whereas after oleic acid, smaller molecular-weight radiotracers had multiexponential clearance curves. This suggests that after oleic acid the alveolar epithelium breaks down in a nonuniform fashion. We conclude that differentiation of the effect of PEEP from that of severe lung injury caused by oleic acid is not readily accomplished by either increasing the size of the tracer molecule or by varying the molecular charge.
Pharmacokinetic analysis of blood distribution of intravenously administered 153Gd-labeled Gd(DTPA)2- and 99mTc(DTPA) in rats.
Wedeking, P; Eaton, S; Covell, D G; Nair, S; Tweedle, M F; Eckelman, W C
Rat plasma distribution data obtained following IV administration of 99mTc(DTPA) alone or after co-administration of 99mTc(DTPA) and 153Gd-labeled Gd(DTPA)2- at 0.001, 0.1, and 1.0 mmol Gd/kg were evaluated using compartmental modeling techniques. A three-compartment open model was found to fit the data significantly better (P less than 0.01) than a two- or four-compartment open model. This model incorporates and links the plasma and urine data and includes a delay to account for the transit time through the kidneys/ureters. The two nonplasma compartments of the model were assumed to be related to rapidly and slowly equilibrating tissues. Tc(DTPA) and Gd(DTPA)2- had nearly identical pharmacokinetic profiles in plasma and the rate constants were essentially the same. No significant dose dependent pharmacokinetic differences were found for the range of Gd(DTPA)2- doses tested. Simulations of the proposed three-compartment model were used to generate concentration-time curves for each of the three compartments. PMID:2082126
Somatostatin receptor scintigraphy using [111In-DTPA0]RC-160 in humans: a comparison with [111In-DTPA0]octreotide.
Breeman, W A; van Hagen, P M; Kwekkeboom, D J; Visser, T J; Krenning, E P
Somatostatin receptor-positive lesions can be visualized by scintigraphy using [111In-DTPA0]octreotide. Recently, there have been reports of differences in receptor binding between somatostatin receptor subtypes and between somatostatin analogues, such as RC-160 and octreotide, as well as of differences in internalization between the somatostatin receptor subtypes. The possibility that certain somatostatin receptor-positive tissues and tumours which do not bind octreotide may bind and internalize RC-160 would open new scintigraphic or radiotherapeutic applications of radiolabelled RC-160. We investigated the metabolism and tissue distribution of [111In-DTPA0]RC-160 in comparison with [111In-DTPA0]octreotide in four patients after injection of 250 MBq (10 microgram) of these radiopharmaceuticals. Patient 1 had a metastatic follicular thyroid carcinoma, patient 2 a metastatic medullary thyroid carcinoma, patient 3 tuberculosis and patient 4 an insulinoma. The plasma clearance of the [111In-DTPA0]RC-160 was slower than that of [111In-DTPA0]octreotide, with 5% and 2%, respectively, of the initial plasma radioactivity remaining at 10 h p.i. The urinary excretion of [111In-DTPA0]RC-160 was initially also slower than that of [111In-DTPA0]octreotide, but the cumulative excretion of radioactivity was not significantly different at 48 h p.i. Approximately 80% of injected radioactivity was cleared in the urine, while in one patient 20% of the injected dose was recovered in the faeces. The slower clearance of [111In-DTPA0]RC-160 resulted in a higher background in all organs studied i.e. liver, spleen, kidneys and lungs, at 24 h p.i. Although the target to background ratio with [111In-DTPA0]octreotide was higher, no differences were found between the two analogues with regard to their sensitivity in detecting lesions in these four patients. We conclude that although only four subjects were studied, [111In-DTPA0]RC-160 does not appear to have additional value for scintigraphy and is associated with higher background activity. PMID:9473268
A case of Budd-Chiari syndrome: Gd-EOB-DTPA-enhanced MR findings.
Kitajima, Kazuhiro; Yoshikawa, Takeshi; Seo, Yasushi; Ohno, Yoshiharu; Yano, Yoshihiko; Miki, Akira; Kanda, Tomonori; Kanata, Naoki; Azuma, Takeshi; Sugimura, Kazuro
Budd-Chiari syndrome (BCS) is a rare disorder caused by the obstruction of hepatic venous outflow, leading to sinusoidal congestion, ischemic injury to liver cells and portal hypertension. Long-term survival largely depends on whether hepatocellular carcinoma occurs. A recently available liver-specific contrast medium, gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA), reportedly has high diagnostic capability for detection of malignant liver tumors. However, there has been no report of the sue of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for BCS. We present a case of chronic BCS who underwent both gadopentetate dimeglumine (Gd-DTPA) and Gd-EOB-DTPA-enhanced MRI. Hepatic congestion and edema were seen as slightly hypointense areas on Gd-EOB-DTPA-enhanced hepatobiliary-phase images, although these areas were observed as slightly hyperintense on previously obtained Gd-DTPA-enhanced delayed-phase image. Reduced uptake of Gd-EOB-DTPA by hepatocytes in the region of congestion or edema may account for this difference, which should be recognized in image interpretations. PMID:21216550
NASA Astrophysics Data System (ADS)
Buseck, P. R.; Schwartz, S. E.
It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 ?m, PM2.5=0.3 ?g m-3; particulate matter of aerodynamic diameter less than 10 ?m, PM10=1.1 ?g m-3; estimated coefficient of light scattering by particulate matter, ?ep, at 570 nm=12 Mm-1). (b) High aerosol concentration (PM2.5=43.9 ?g m-3; PM10=83.4 ?g m-3; estimated ?ep at 570 nm=245 Mm-1) (reproduced by permission of National Park Service, 2002). Although comprising only a small fraction of the mass of Earth's atmosphere, aerosol particles are highly important constituents of the atmosphere. Special interest has focused on aerosols in the troposphere, the lowest part of the atmosphere, extending from the land or ocean surface typically to ś8 km at high latitudes, ś12 km in mid-latitudes, and ś16 km at low latitudes. That interest arises in large part because of the importance of aerosol particles in geophysical processes, human health impairment through inhalation, environmental effects through deposition, visibility degradation, and influences on atmospheric radiation and climate.Anthropogenic aerosols are thought to exert a substantial influence on Earth's climate, and the need to quantify this influence has sparked much of the current interest in and research on tropospheric aerosols. The principal mechanisms by which aerosols influence the Earth radiation budget are scattering and absorbing solar radiation (the so-called "direct effects") and modifying clouds and precipitation, thereby affecting both radiation and hydrology (the so-called "indirect effects"). Light scattering by aerosols increases the brightness of the planet, producing a cooling influence. Light-absorbing aerosols such as black carbon exert a warming influence. Aerosols increase the reflectivity of clouds, another cooling influence. These radiative influences are quantified as forcings, where a forcing is a perturbation to the energy balance of the atmosphere-Earth system, expressed in units of watts per square meter, W m-2. A warming influence is denoted a positive forcing, and a cooling influence, negative. The radiative direct and indirect forcings by anthropogenic aerosols are thought to be of comparable magnitude to the posi
[Evaluation of SPECT with N-isopropyl [I-123]-p-iodoamphetamine (IMP) or technetium-99m [99mTc]-d,l-hexamethylpropyleneamine oxime (d, 1-HM-PAO) in cerebral concussion].
Torigoe, R; Hayashi, T; Anegawa, S; Harada, K; Matsuo, H; Yoshikawa, I
123I-IMP and Tc-PAO SPECT were performed in 20 cases of cerebral concussion ranging in age from 4 to 20 years old, including six cases of the juvenile head trauma syndrome (JHTS). The SPECT findings were divided into two main types: six cases in the normal group with no blood flow abnormalities, and 14 cases in abnormal group showing reduced blood flow, mainly in cerebellum and occipital lobe except in one case. In 10 cases with reduced blood flow which could be analyzed, calculation of the blood flow ratio in the temporal and occipital lobes and the cerebellum with the frontal lobe taken as 100 showed values of 93.5% for the temporal lobe, 82.7% for the occipital lobe and 76.8% for the cerebellum. A statistically significant reduction in blood flow occurred in the occipital lobe and cerebellum. In blood examination, abnormally high values of white blood cell counts were observed transiently in 94% of cerebral concussion cases. Abnormalities in brain stem and hypothalamus appeared to cause these abnormal WBC values. From these findings, it was suggested that the blood flow regions of the basilar and posterior cerebral arteries, i.e., the brain stem and hypothalamus are closely connected with the lesions responsible for cerebral concussion. It also appeared that the JHTS occurs in cerebral concussion cases where recovery of the abnormal blood flow in these regions in poor. PMID:1910937
Gadolinium-DTPA: a new contrast agent for magnetic resonance imaging.
Niendorf, H P; Felix, R; Laniado, M; Sch÷rner, W; Claussen, C; Weinmann, H J
Gd-DTPA-dimeglumine is a new contrast agent for magnetic resonance imaging. Its safety and efficacy in man were evaluated in 20 volunteers and 60 patients. For determination of tolerance of Gd-DTPA, blood and urine samples were taken and blood pressure, pulse rate, and ECG were recorded before and after injection. The results of these analyses showed no clinically relevant changes. In MR imaging of intracranial lesions Gd-DTPA serves as an indicator of function or disfunction of the blood-brain-barrier, because its pharmacokinetic behavior is very similar to that of urographic iodinated contrast media used now for X-ray CT. And so by using Gd-DTPA it is possible to differentiate between neoplastic tissue and perifocal edema, to determine the extension of tumor infiltration, and to detect tumor recurrence. PMID:4070676
Functional dynamic MRI, pharmacokinetics and safety of Gd-DTPA in patients with impaired renal function
G. P. Krestin; G. Schuhmann-Giampieri; J. Haustein; G. Friedman; K. R. R. Neufang; W. Clau▀; B. St÷ckl
Renal elimination of the paramagnetic contrast agent Gadolinium-DTPA (Gd-DTPA) was analyzed in 24 patients with impaired renal function and 3 normal controls. Dynamic magnetic resonance studies were performed using fast gradient-echo sequences with single images during suspended respiration and a temporal resolution of 10s per image. The time between appearance of the contrast agent in the renal cortex and signal
Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex
R. C. Brasch; H. J. Weinmann; G. E. Wesbey
Gadolinium (Gd)-DTPA complex was assessed as a nuclear magnetic resonance (NMR) contrast-enhancing agent by experimentally imaging normal and diseased animals. After intravenous injection, Gd-DTPA, a strongly paramagnetic complex by virtue of unpaired electrons, was rapidly excreted into the urine of rats, producing an easily observable contrast enhancement on NMR images in kidney parenchyma and urine. Sterile soft-tissue abscesses demonstrated an
Evaluating the toxicity of novel Zn-DTPA tablet formulation in dogs and rats.
Shankar, Gita N; Potharaju, Suresh; Green, Carol E
The purpose of this research work is to evaluate toxicity of diethylenetriamine pentaacetic acid zinc trisodium salt (Zn-DTPA) tablets, a novel oral solid dosage form containing permeation enhancers in beagle dogs and Sprague Dawley rats. (Zn-DTPA) in tablet dosage form was administered once daily for 7 days to beagle dogs at low (840?mg/dog/day), mid (2520?mg/dog/day), or high (7560?mg/dog/day). On day 8, all treated and control groups were necropsied. The novel Zn-DTPA tablet formulation showed rapid absorption with the T(max) at 1?h. Plasma concentrations as high as 270??g/mL were observed after 7 days of administration. Exposure to DTPA, based on area under the curve (AUC(last)) and maximum concentration (C(max)), was dose dependent but not dose proportional. No biologically relevant changes in hematology or clinical chemistry that were related to DTPA exposure were observed, and there were no changes in body weight in treated dogs compared with controls. Zn-DTPA was well tolerated, with minor toxicological effects of emesis and diarrhea, following oral tablet administration for 7 consecutive days. Based on the endpoints evaluated in this study, the maximum tolerated dose is considered to be greater than 7560?mg/dog/day (2535??mol/kg/day, 1325?mg/kg/day), and the no-observed-adverse-effect level (NOAEL) is considered to be approximately 1325?mg/kg/day per oral when given to male and female beagle dogs. For rats, the NOAEL was estimated to be greater than 1000?mg/kg/day when administered by oral gavage of the crushed Zn-DTPA tablets as suspension once daily (qd) to male and female Sprague Dawley rats. PMID:24648048
Gd-EOB-DTPA-enhanced magnetic resonance imaging for bile duct intraductal papillary mucinous neoplasms
Ying, Shi-Hong; Teng, Xiao-Dong; Wang, Zhao-Ming; Wang, Qi-Dong; Zhao, Yi-Lei; Chen, Feng; Xiao, Wen-Bo
AIM: To investigate gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) of intraductal papillary mucinous neoplasms of the bile duct (IPMN-B). METHODS: The imaging findings of five cases of IPMN-B which were pathologically confirmed at our hospital between March 2012 and May 2013 were retrospectively analyzed. Three of these cases were diagnosed by duodenal endoscopy and biopsy pathology, and two cases were diagnosed by surgical pathology. All five patients underwent enhanced and non-enhanced computed tomography (CT), magnetic resonance cholangiopancreatography, and Gd-EOB-DTPA-enhanced MRI; one case underwent both Gd-EOB-DTPA-enhanced MRI and positron emission tomography-CT. The clinical data and imaging results for these cases were compared and are presented. RESULTS: Conventional imaging showed diffuse dilatation of bile ducts and multiple intraductal polypoid and papillary neoplasms or serrated changes along the bile ducts. In two cases, Gd-EOB-DTPA-enhanced MRI revealed dilated biliary ducts and intraductal tumors, as well as filling defects caused by mucin in the dilated bile ducts in the hepatobiliary phase. Gd-EOB-DTPA-enhanced MRI in one case clearly showed a low-signal tumor in the hepatobiliary phase, similar to what was seen by positron emission tomography-CT. In two patients, routine inspection was unable to discern whether the lesions were inflammation or tumors. However, Gd-EOB-DTPA-enhanced MRI revealed a pattern of gradual enhancement during the hepatobiliary phase, and the signal intensity of the lesions was lower than the surrounding liver parenchyma, suggesting tissue inflammation in both cases, which were confirmed by surgical pathology. CONCLUSION: Gd-EOB-DTPA-enhanced MRI reveals the intraductal mucin component of IPMN-B in some cases and the extent of tumor infiltration beyond the bile ducts in invasive cases.
Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex.
Brasch, R C; Weinmann, H J; Wesbey, G E
Gadolinium (Gd)-DTPA complex was assessed as a nuclear magnetic resonance (NMR) contrast-enhancing agent by experimentally imaging normal and diseased animals. After intravenous injection, Gd-DTPA, a strongly paramagnetic complex by virtue of unpaired electrons, was rapidly excreted into the urine of rats, producing an easily observable contrast enhancement on NMR images in kidney parenchyma and urine. Spin-echo intensity of urine within the renal pelvis increased from 2263 to 4414 units; intensity of renal parenchyma increased from 2901 to 3893 after administration of 0.1 mmol/kg Gd-DTPA. Sterile soft-tissue abscesses demonstrated an obvious rim pattern of enhancement. A focus of radiation-induced brain damage in a canine model was only faintly detectable on spin-echo NMR images before contrast administration; after 0.5 mmol/kg Gd-DTPA administration, the lesion intensity increased from 3867 to 5590. In comparison, the normal brain with an intact blood-brain barrier remained unchanged in NMR characterization. Gd-DTPA is a promising new NMR contrast enhancer for the clinical assessment of renal function, of inflammatory lesions, and of focal disruption of the blood-brain barrier. PMID:6607656
Biodistribution and magnetic resonance imaging of cross-linked DTPA polysaccharides.
Gibby, W A; Billings, J; Hall, J; Ovitt, T W
Large polysaccharide complexes, cross-linked with DTPA and chelated with gadolinium have been tested for various potential uses for magnetic resonance imaging (MRI) in rats. Biodistribution and pharmacokinetic data for several of the soluble polymers are presented and compared with Gd-DTPA and GdCl3. By varying the initial polysaccharide length and ratio of DTPA to glucose units, polymers of molecular weights (mol wt) from 17,000 to several million were formed, giving soluble material, gels, or particles. The larger polymers (mol wt greater than 100,000) demonstrate prolonged enhancement of the intravascular space, striking renal enhancement, and moderate hepatic uptake. Small particulate material (less than 10 microns) was also successfully used for intravascular enhancement. The material is metabolized and excreted in urine. PMID:1690184
[Brain and spinal tumors: magnetic resonance imaging using gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA)].
Fang, Y X
Magnetic resonance imaging (MRI) was performed in 17 patients (with 24 tumors) before and after intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Contrast enhancement was seen in 16 patients. The image pattern of enhancement is the same as that of CT. With 0.1 mmol/kg intravenous bolus injection, the best enhancement can keep for one hour. In brain, the degree of enhancement was greater than that seen with CT in 7 tumours, equal to it in 12 tumors, and less in zero. MRI distinguished between tumour and peritumoral edema to the same extent as did CT. No side-effects were encountered and there was no significant change in regular urine and blood tests after administration of Gd-DTPA. T1-weighted images of spin echo pulse sequence are the best pulse sequence to observe the enhancement. Gd-DTPA is of considerable value in MRI of the brain and spine. PMID:2804747
SELECTIVE BETA IRRADIATION OF THE LYMPHATIC SYSTEM USING INTERNALLY ADMINISTERED YŌü╣┬░ DTPA: KINETICS, DOSIMETRY, AND BIOLOGICAL EVALUATION (thesis)
In order to provide for the relatively selective irradiation of the ; tissue responsible for the homograft rejection response while minimizing the ; exposure of other tissues, a technique using internally administered YŌü╣┬░ ; chelated with DTPA (diethylene-triamine-pentaacetic acid) was developed. By use ; of continuous intravenous recycling of the urine containing the excreted YŌüĖ┬░; -DTPA a method was developed
In vivo and in vitro evaluation of Gd-DTPA-polylysine as a macromolecular contrast agent for magnetic resonance imaging.
Schuhmann-Giampieri, G; Schmitt-Willich, H; Frenzel, T; Press, W R; Weinmann, H J
Polylysine covalently linked to moieties of gadopentetate (Gd-DTPA), for use as a macromolecular blood pool marker for contrast material-enhanced magnetic resonance imaging (MRI), was characterized by means of physicochemical measurements and pharmacokinetics in rats and rabbits and compared with Gd-DTPA. Gd-DTPA-polylysine was composed of a series of polymers of different molecular sizes that on average were labeled with 60 to 70 Gd-DTPA moieties (average molecular weight, 48,700 daltons [D]). For the macromolecular compound Gd-DTPA-polylysine, relaxivity was three times higher than that of Gd-DTPA. The LD50 value of 17 mmol/kg reflects a fairly high acute intravenous tolerance of the macromolecular compound in mice. Even though the volume of distribution of Gd-DTPA-polylysine in rabbits approached the extracellular fluid space (indicating that the macromolecular compound was also leaking slowly into the interstitial space), the half-life of distribution of the macromolecular compound in the extracellular fluid space was significantly prolonged, thus making the compound suitable as a blood pool marker for MRI. In rats the elimination of Gd-DTPA-polylysine occurred predominantly via the renal route. High-pressure liquid chromatography-size-exclusion chromatography of the fractionated urine samples revealed that the renal clearance must be the integral sum of the separate clearances of each molecular weight species. No biodegradation of the polypeptide was observed, and biodistribution studies revealed only minimal retention of Gd in the body of the rat. PMID:1743920
Evaluation of Gd-DTPA-monophytanyl and phytantriol nanoassemblies as potential MRI contrast agents.
Gupta, Abhishek; de Campo, Liliana; Rehmanjan, Beenish; Willis, Scott A; Waddington, Lynne J; Stait-Gardner, Tim; Kirby, Nigel; Price, William S; Moghaddam, Minoo J
Supramolecular self-assembling amphiphiles have been widely used in drug delivery and diagnostic imaging. In this report, we present the self-assembly of Gd (III) chelated DTPA-monophytanyl (Gd-DTPA-MP) amphiphiles incorporated within phytantriol (PT), an inverse bicontinuous cubic phase forming matrix at various compositions. The dispersed colloidal nanoassemblies were evaluated as potential MRI contrast agents at various magnetic field strengths. The homogeneous incorporation of Gd-DTPA-MP in PT was confirmed by polarized optical microscopy (POM) and synchrotron small-angle X-ray scattering (SAXS) of the bulk phases of the mixtures. The liquid crystalline nanostructures, morphology, and the size distribution of the nanoassemblies were studied by SAXS, cryogenic transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS). The dispersions with up to 2 mol % of Gd-DTPA-MP in PT retained inverse cubosomal nanoassemblies, whereas the rest of the dispersions transformed to liposomal nanoassemblies. In vitro relaxivity studies were performed on all the dispersions at 0.54, 9.40, and 11.74 T and compared to Magnevist, a commercially available contrast agent. All the dispersions showed much higher relaxivities compared to Magnevist at both low and high magnetic field strengths. Image contrast of the nanoassemblies was also found to be much better than Magnevist at the same Gd concentration at 11.74 T. Moreover, the Gd-DTPA-MP/PT dispersions showed improved relaxivities over the pure Gd-DTPA-MP dispersion at high magnetic fields. These stable colloidal nanoassemblies have high potential to be used as combined delivery matrices for diagnostics and therapeutics. PMID:25580808
The iron(III)-catalyzed oxidation of DTPA in an aqueous solution / longy Steven Harry ChristiansenĀ
Christiansen, Steven Harry
THE IRON(III) -CATALYZED OXIDATION OF DTPA IN AN AQUEOUS SOLUTION A Thesis by STEVEN HARRY CHRISTIANSEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1988 Major Subject: Chemistry THE IRON(III) -CATALYZED OXIDATION OF DTPA IN AN AQUEOUS SOLUTION A Thesis by STEVEN HARRY CHRISTIANSEN Approved as to style and content by: A. E. Martell (Chair of Committee) M. B. Hall (Member) R. H...
Decorporation of systemically distributed americium by a novel orally administered diethylenetriaminepentaacetic acid (DTPA) formulation in beagle dogs.
Wilson, James P; Cobb, Ronald R; Dungan, Nathanael W; Matthews, Laura L; Eppler, Bõrbel; Aiello, Kenneth V; Curtis, Shiro; Boger, Teannetta; Guilmette, Raymond A; Weber, Waylon; Doyle-Eisele, Melanie; Talton, James D
Novel decorporation agents are being developed to protect against radiological accidents and terrorists attacks. Radioactive americium is a significant component of nuclear fallout. Removal of large radioactive materials, such as 241Am, from exposed persons is a subject of significant interest due to the hazards they pose. The objective of this study was to evaluate the dose-related efficacy of daily doses of NanoDTPAÖ Capsules for decorporating Am administered intravenously as a soluble citrate complex to male and female beagle dogs. In addition, the efficacy of the NanoDTPAÖ Capsules for decorporating 241Am was directly compared to intravenously administered saline and DTPA. Animals received a single IV administration of 241Am(III)-citrate on Day 0. One day after radionuclide administration, one of four different doses of NanoDTPAÖ Capsules [1, 2, or 6 capsules d(-1) (30 mg, 60 mg, or 180 mg DTPA) or 2 capsules BID], IV Zn-DTPA (5 mg kg(-1) pentetate zinc trisodium) as a positive control, or IV saline as a placebo were administered. NanoDTPAÖ Capsules, IV Zn-DTPA, or IV saline was administered on study days 1-14. Animals were euthanized on day 21. A full necropsy was conducted, and liver, spleen, kidneys, lungs and trachea, tracheobronchial lymph nodes (TBLN), muscle samples (right and left quadriceps), gastrointestinal (GI) tract (stomach plus esophagus, upper and lower intestine), gonads, two femurs, lumbar vertebrae (L1-L4), and all other soft tissue remains were collected. Urinary and fecal excretion profiles were increased approximately 10-fold compared to those for untreated animals. Tissue contents were decreased compared to untreated controls. In particular, liver content was decreased by approximately eightfold compared to untreated animals. The results from this study further demonstrate that oral NanoDTPAÖ Capsules are equally efficient compared to IV Zn-DTPA in decorporation of actinides. PMID:25627942
Lung Deposition and Pharmacokinetics of Nebulized Cyclosporine in Lung Transplant Patients
Niven, R.; Verret, W.; Dilly, S.; Johnson, B.A.
Abstract Background: Inhaled cyclosporine (CsA) is being investigated as a prophylaxis for lung transplant rejection. Lung deposition and systemic exposure of nebulized CsA in lung transplant patients was evaluated as part of the Phase 3 cyclosporine inhalation solution (CIS) trial (CYCLIST). Methods: Ten patients received 300?mg of CIS (62.5?mg/mL CsA in propylene glycol) admixed with 148?MBq of Tc-DTPA (technetium-99m bound to diethylenetriaminepentaacetic acid) administered using a Sidestream« disposable jet nebulizer. Deposition was assessed using a dual-headed gamma camera. Blood samples were collected over a 24-hr time period after aerosol dosing and analyzed for CsA levels. A pharmacokinetic analysis of the resulting blood concentration versus time profiles was performed. Results: The average total deposited dose was 53.7▒12.7?mg. Average pulmonary dose was 31.8▒16.3?mg, and stomach dose averaged 15.5▒11.1?mg. Device performance was consistent, with breathing maneuvers influencing dose variation. Predose coaching with five of 10 patients reduced stomach deposition (22.6▒11.2 vs. 8.3▒5.2?mg; p=0.03). Blood concentrations declined quickly from a maximum of 372▒140?ng/mL to 15.3▒9.7?ng/mL at 24?hr post dose. Levels of AUC(0¢24) [area under the concentration vs. time curve from 0 to 24?hr] averaged 1,493▒746?ng hr/mL. On a three times per week dose regimen, this represents <5% of the weekly systemic exposure of twice per day oral administration. Conclusions: Substantial doses of CsA can be delivered to the lungs of lung transplant patients by inhaled aerosol. Systemic levels are small relative to typical oral CsA administration. PMID:23668548
Kidney scintigraphy after ACE inhibition in the diagnosis of renovascular hypertension
Ghione, S.; Fommei, E.; Palombo, C.; Giaconi, S.; Mantovanelli, A.; Ragazzini, A.; Palla, L.
Suppression of the renin-angiotensin system (RAS) by angiotensin converting enzyme (ACE) inhibition may induce renal failure in patients with bilateral renal artery stenosis. Recent scintigraphic studies with the glomerular tracer technetium-99m-diethylenetriaminepenta-acetate (99m-Tc DTPA) indicate that in patients with unilateral renal artery stenosis, glomerular filtration rate (GFR) may be markedly reduced in the affected kidney after inhibition of ACE. This finding reflects the important role of the RAS in maintaining GFR (by increasing postglomerular resistance) in states of low renal perfusion pressure. Preliminary observations suggest that this scintigraphic test might be useful in the detection of renovascular hypertension.
Discrimination of aerosol types and absorbing aerosols
NASA Astrophysics Data System (ADS)
Cachorro, Victoria E.; Prats, Natalia; Mogo, Sandra I.; Toledano, Carlos; Berjon, Alberto J.; Montilla, Elena; Torres, Benjamin; Rodrigo, Ruben; Fuertes, David; Gonzalez, Ramiro; Bennouna, Yasmine S.; de Frutos, Angel
Aerosol particles are one of the most variable components in the Earth's atmosphere, affecting the radiative balance and influencing the climate system by direct and indirect effects. To evaluate these two effects the optical-radiative properties of aerosols are the key elements and hence the necessity of their retrieval. Many detailed campaigns of measurements have been carried out in the past and will continue in the future at different sites in the world to assess all these aerosol properties which are relevant to evaluate the aerosol climate forcing ARF. Otherwise worldwide aerosol networks, as AERONET, are also a potential tool for the aerosol characterization and evaluation of ARF. The most relevant aerosol parameters involved are the aerosol optical depth AOD, the Angstrom exponent AE, and the single scattering albedo SSA or the absorption aerosol optical depth AAOD. Working with remote sensing aerosol data, like those provided by sun-photometer or spectroradiometers, requires inverse radiative transfer algorithms to retrieve the earlier men-tioned optical properties. For instance, AERONET provide sufficient parameters for the aerosol type discrimination, allowing differentiate continental, marine, desert, smoke, etc. aerosol types. Traditionally, AOD-AE plots allow a good discrimination which is enriched with air masses in-formation. Although aerosol types determined in this way gives some insights about aerosol composition this is not sufficient. SSA or AAOD gives the required additional information which is also improved if the absorption Angstrom exponent (AAE) is added. Thus, taking spectral information of all of these parameters can help us to identify some features or signa-tures about aerosol composition. In this framework and in the near future we will work in the link or connexion between columnar AERONET aerosol properties and those given by "in situ" aerosol information data.
Posttraumatic lumbar cerebrospinal fluid leak: detection by retrograde In111DTPA myeloscintography
A case of lumbar cerebrospinal fluid (CSF) extravasation with an unsuspected traumatic meningocele after a gunshot wound was detected by means of retrograde myeloscintography using isobaric In-111-DTPA. Our experience and a review of the literature have provided evidence retrograde myeloscintography may be useful for detecting and delineating significant traumatic thoracic and lumbar CSF leaks.
Factors affecting DTPA?extractable Zn, Fe, Mn, and Cu from soils
P. N. Soltanpour; A. Khan; W. L. Lindsay
Tests were made to determine the effects of grinding, type of extraction vessel, type of shaker, speed of shaking, time of shaking, time of filtering, soil to solution ratio and other variables on DTPA?extractable Zn, Fe, Mn, and Cu from soils.Time of grinding, force of grinding, and the quantity of soil being ground greatly affected the amount of extractable Fe.
Renal tolerance of gadolinium-DTPA/dimeglumine in patients with chronic renal failure.
Haustein, J; Niendorf, H P; Krestin, G; Louton, T; Schuhmann-Giampieri, G; Clauss, W; Junge, W
Safety data for renal tolerance of gadolinium-DTPA(Gd-DTPA)/dimeglumine were evaluated in 21 patients (age: mean +/- standard deviation [SD], 58 +/- 12 years) with impaired renal function. The mean +/- SD serum creatinine level at baseline was 213 +/- 101 mumol/L (range, 89.2-551 mumol/L). Creatinine clearance at baseline averaged 34.5 +/- 19.2 mL/minute (range, 7.2-70 mL/minute). Gd-DTPA was injected at a dose of 0.1 mmol/kg body weight. Serum parameters (creatinine, sodium, and potassium) were determined before and 6, 24, 48, and 120 hours after administration of Gd-DTPA. Urinary parameters (N-acetyl-beta-D-glucosaminidase [beta-NAG], protein, and albumin) were determined before (spot urine sample) and after treatment for collection periods 0 to 3, 3 to 6, 6 to 12, 12 to 24, and 24 to 48 hours. A final spot urine sample was taken at 120 hours. There was no significant statistical change of serum creatinine level within the observation period, and there was no single patient matching the criteria of acute renal failure (increase of serum creatinine level of 88.4 mumol/L [1 mg/dL] or more within 48 hours after injection). Serum values of sodium and potassium levels remained unchanged. Beta-NAG was slightly increased 0 to 3 hours after injection, but returned to baseline values during the collection periods up to 120 hours. There was no increase of protein or albumin excretion. These preliminary results suggest Gd-DTPA has good renal tolerance in patients with pre-existing chronic renal failure. PMID:1601607
Pretargeted tumour imaging with streptavidin immunoconjugates of monoclonal antibody CC49 and 111In-DTPA-biocytin
Teresa M. Alvarez-Diez; Jeannie Polihronis; Raymond M. Reilly
Pretargeted tumour imaging was performed in nude mice bearing subcutaneous LS174T human colon cancer xenografts with streptavidin-CC49 monoclonal antibody and 111In-DTPA-biocytin. Mice were administered 250 ?g of streptavidin-CC49, followed 6 or 9 days later by 40 ng (250 ?Ci) of 111In-DTPA-biocytin. Tumors were visualized at 24 h postinjection of 111In-DTPA-biocytin. Tumour uptake was 0.9¢2.5% injected dose\\/g with tumour\\/nontarget ratios from
Global Atmospheric Aerosol Modeling
NASA Technical Reports Server (NTRS)
Hendricks, Johannes; Aquila, Valentina; Righi, Mattia
Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.
Enhancement characteristics of liver metastases, hepatocellular carcinomas, and hemangiomas with Gd-EOB-DTPA: preliminary results with dynamic MR imaging
P. Reimer; E. J. Rummeny; H. E. Daldrup; T. Hesse; T. Balzer; B. Tombach; P. E. Peters
.ĀĀ Our objective was to study Gd-EOB-DTPA for the characterization of focal liver lesions by means of dynamic MR imaging. A\\u000a double-blind and randomized dose-ranging phase-2 clinical trial was performed in 31 patients (liver metastases n = 23, hepatocellular carcinoma n = 4, and hemangioma n = 4) at a field strength of 1.0 Tesla. Gd-EOB-DTPA (Schering AG, Berlin, Germany)
Magnetic resonance imaging with Gadolinium-DTPA for assessment of bladder carcinoma and its response to treatment.
Hawnaur, J M; Johnson, R J; Read, G; Isherwood, I
Magnetic Resonance Imaging (MRI) with intravenous Gadolinium-DTPA (Gd-DTPA, Magnevist, Schering-AG) was performed in 44 patients, 32 with primary bladder carcinoma and 12 with suspected recurrence after treatment. Gd-DTPA often increased diagnostic confidence in the identification and staging of tumours confined to the bladder wall and was necessary to assess depth of bladder wall invasion when T2-weighted images were suboptimal. Enhancement after Gd-DTPA enabled distinction between necrotic and viable tumour and blood clot. There was little advantage in its use for tumours infiltrating perivesical fat or with metastases to lymph nodes or bone, in the absence of a fat suppression sequence. Gd-DTPA may therefore be useful in selected patients with tumours of Stage T3a or less in whom information about depth of bladder wall invasion is inadequately shown on pre-contrast sequences. Artefacts due to variable and inhomogeneous urine signal intensity, however, often degraded post-Gd-DTPA images of the bladder. Changes in the bladder due to radiotherapy were observed on MRI 3-4 months after treatment in patients referred for routine follow-up and in some patients with suspected recurrence. Mucosal hyperintensity, thickening and abnormal signal intensity of the muscular layers of the bladder wall, with enhancement after Gd-DTPA were demonstrated. Such changes obscured small volume or superficial recurrence of tumour after radiotherapy. Abnormal enhancement was also observed in pelvic organs and soft tissues irradiated several years earlier. Enhancement after Gd-DTPA does not therefore reliably distinguish between recurrent tumour and radiotherapy change. PMID:8508591
NASA Technical Reports Server (NTRS)
Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)
An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the aerosol should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.
The iron(III)-catalyzed oxidation of DTPA in an aqueous solution / longy Steven Harry Christiansen
Christiansen, Steven Harry
is utilized to complex iron ions in the system. 21 In aqueous solutions, Fe(III)-DTPA can exist in three pH dependent forms. In the acid range, FeHL and FeL are the predominate species with the later being favored as the pH approaches 7. At higher p.... 87 Iron (III) Fe3 + L4 ~~ FeL1 Fe3 + H+ FeHL Fe3 + OH ~ FeLOH logKlo logK2 logK3o 25. 1 6. 45 23 TABLE 2b: Stability constants for the free acid, iron- (II) and iron(III) chelates of DTPA (11). Reaction Log K value Deprotonation H5L...
Gadolinium-DTPA as a contrast agent in MRI: initial clinical experience in 20 patients
Carr, D.H.; Brown, J.; Bydder, G.M.; Steiner, R.E.; Weinmann, H.J.; Speck, U.; Hall, A.S.; Young, I.R.
Magnetic resonance imaging (MRI) was performed in 20 patients before and after intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Twelve of the patients had clinical and histologic diagnoses of cerebral tumor, six had hepatic tumors, one had hepatic cysts, and one had transitional cell carcinoma of the bladder. Contrast enhancement was seen with all tumors, but not with the hepatic cysts. The degree of enhancement was greater than that seen with computed tomography (CT) in 13 cases, equal to it in six, and less in one. No short-term side effects were encountered and no significant change was seen in urea, creatinine, electrolytes, liver function tests, blood coagulation, or urine testing after injection of Gd-DTPA. Although much more work will be required to evaluate this contrast agent, these initial experiences are very promising.
Detection of hepatocellular carcinoma: comparison of Gd-DTPA- and ferumoxides-enhanced MR imaging
G. Simon; T. M. Link; K. W÷rtler; F. Doebereiner; E. Schulte-Frohlinde; H. Daldrup-Link; M. Settles; E. J. Rummeny
The aim was to compare the diagnostic performance of dynamic Gd-DTPA- and ferumoxides-enhanced MRI for hepatocellular carcinoma (HCC). Twenty-five patients with chronic hepatitis or liver cirrhosis underwent both dynamic gadopentetate- and ferumoxides-enhanced MRI studies of the liver for HCC detection on the same day. MR data of both studies were retrospectively and independently analyzed. Two observers determined in consensus the
Rhenium188-labeled DTPA: a new radiopharmaceutical for intravascular radiation therapy
Bor-Tsung Hsieh; Jih-Fang Hsieh; Shih-Chuan Tsai; Wan-Yu Lin; Hen-Ton Huang; Gann Ting; Shyh-Jen Wang
Balloon angioplasty is a standard treatment for artherosclerotic coronary artery disease. However, its clinical value is reduced by a high restenosis rate. A new concept in preventing restenosis is the use of a liquid-filled balloon containing a beta-emitting radioisotope. In this study, we performed biodistribution studies of Re-188 perrhenate and Re-188 diethylenetriaminopentaacetate (DTPA) to assess the resulting organ dose values
Mn-54 DTPA distribution in dogs: Evaluation as a potential NMR contrast agent
Boudreau, R.J.; Frick, M.P.; Levy, R.M.; Sirr, S.A.; Lund, G.; Loken, M.K.
Several paramagnetic ions are currently being evaluated as potential contrast agents for NMR imaging. To date the most successful of these appears to be Gd-DTPA. The authors recently undertook an investigation into the kinetics of biodistribution of Mn-DTPA to determine if this agent showed any tissue specific uptake, and if so, to optimize the time for imaging. In order to obviate the need for repetitive quantitative NMR imaging they have substituted tracer amounts of Mn-54 for the stable ion. Following intravenous injection into three mongrel dogs, samples of blood, bowel, liver, and pancreas were obtained at 3, 15, 30 and 60 minutes and 2, 4 and 6 hours post-injection. Radioactivity, and thus tissue concentration, was then determined in a gamma counter. Urine was also collected throughout the study. At six hours 58.4 +- 7.1% of the injected dose had been excreted in the urine. Peak liver accumulation occurred within 30 minutes (0.503 +- 0.144% injected dose/gm x kg body weight). The pancreas also showed a relatively high accumulation of tracer (0.247 +- 0.039%/gram x kg body weight) by four hours. The pancreas to liver ratios were highest at six hours (.73). The blood concentration fell very rapidly with little tracer remaining in the blood at one hour. The results of these experiments indicate that a significant portion of the injected material was concentrated by liver and pancreas. Unlike MnCl/sub 2/, most of the Mn-DTPA is excreted in the urine. This excretion is expected to reduce the toxicity of the injected material. These results are being used to establish the optimal protocols for NMR imaging with Mn-DTPA.
Comparative analysis of different scintigraphic approaches to assess pulmonary ventilation.
Magnant, J; Vecellio, L; de Monte, M; Grimbert, D; Valat, C; Boissinot, E; Guilloteau, D; Lemariķ, E; Diot, P
A study was carried out to investigate the predictive value of 81-metastable-krypton (81mKr) distribution, high-size 99-metastable-technetium (99mTc) aerosol deposition and low-size 99mTc aerosol (Technegas) deposition on the pulmonary ventilation evaluated by 133-xenon (133Xe) lung scintigraphy, and to assess the correlation between the 81mKr distribution, the 99mTc aerosols deposition, and the respiratory parameters of patients with chronic obstructive pulmonary disease (COPD). Twenty COPD patients were included. The 81mKr, 133Xe, and 99mTc aerosol lung scintigraphies were successively carried out. The 81mKr distribution and 99mTc deposition were compared to the 133Xe distribution at equilibrium and to the 133Xe clearance. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 81mKr and Technegas lung scintigraphies to detect alterations in ventilation revealed by 133Xe were defined. The 81mKr distribution and 99mTc deposition according to respiratory parameters were described using a principal component analysis. Compared to 133Xe distribution, a significantly higher distribution of 81mKr in the upper parts of the lungs in the more severe patients (p = 0.05), a significantly higher deposition of Technegas in the lower parts of the lungs (p = 0.0008), and a significantly higher deposition in the central parts of the high-size 99mTc aerosol were observed (p = 0.0001). The PPV and the NPV were, respectively, 0.54 and 0.58 for 81mKr and 0.54 and 0.55 for Technegas. There was a significant negative correlation between 81mKr distribution and 133Xe clearance (p = 0.0001) between Technegas deposition and 133Xe clearance (p = 0.0007), and between 99mTc diethylene-triamino-penta-acetate (DTPA) deposition and 133Xe clearance (p = 0.001). Both the 81mKr peripheral distribution and Technegas peripheral deposition correlated negatively with increased obstruction, as measured by forced expiratory volume in 1 sec (FEV1). Peripheral deposition of the high-size 99mTc aerosol deposition correlated with the inspiration/expiration time ratio. In conclusion, 81mKr and 99mTc aerosols' lung scintigraphies do not reflect exactly the pulmonary ventilation as measured by 133Xe scintigraphy. PMID:16796539
Gadolinium-DTPA as a contrast agent in MRI: initial clinical experience in 20 patients.
Carr, D H; Brown, J; Bydder, G M; Steiner, R E; Weinmann, H J; Speck, U; Hall, A S; Young, I R
Magnetic resonance imaging (MRI) was performed in 20 patients before and after intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) in a dose of 0.1 mmol/kg. Twelve of the patients had clinical and histologic diagnoses of cerebral tumor, six had hepatic tumors, one had hepatic cysts, and one had transitional cell carcinoma of the bladder. Contrast enhancement was seen with all tumors, but not with the hepatic cysts. The degree of enhancement was greater than that seen with computed tomography (CT) in 13 cases, equal to it in six, and less in one. Contrast enhancement was detectable as long as 18 hr after injection of Gd-DTPA in one case of cerebral tumor. The margin between cerebral tumor and peritumoral edema could be delineated with contrast-enhanced MRI to the degree possible with contrast-enhanced CT. In the liver isointense enhancement was seen with saturation-recovery (SR), inversion-recovery (IR), and spin-echo (SE) sequences although not with all three sequences simultaneously. In general IR sequences were most sensitive for display of the contrast agent, but the enhancement often decreased the difference between abnormal and normal tissue. No short-term side effects were encountered and no significant change was seen in urea, creatinine, electrolytes, liver function tests, blood coagulation, or urine testing after injection of Gd-DTPA. Although much more work will be required to evaluate this contrast agent, these initial experiences are very promising. PMID:6611046
Pharmacokinetics of Gd-DTPA in patients with chronic renal failure.
Schuhmann-Giampieri, G; Krestin, G
We investigated the pharmacokinetics of dimeglumine gadopentetate (Gd-DTPA), a contrast agent for magnetic resonance imaging (MRI), in 24 patients with chronic renal failure whose creatinine clearance ranged from 7.2 to 70.0 mL/minute (median 25.4 mL/minute). After single intravenous administration of 0.1 mmol/kg, the serum levels of Gd-DTPA were monitored up to five days and urine and feces were collected quantitatively up to two days. The pharmacokinetic parameters were calculated from the concentration-time profile in the serum and urine using an open two-compartment model. No changes in the volume of distribution (Vc and Varea) or in the half-life of distribution were found for patients with chronic renal failure as compared to patients with normal renal function. However, in correlation with the reduced glomerular filtration rate in patients with chronic renal failure, the half-life of elimination was prolonged and serum and renal clearance were decreased. The recovery of Gd-DTPA in urine was 92.1% +/- 12.1% of the dose administered, and extrarenal elimination was less than 0.4%, indicating that glomerular filtration remains the predominant route of elimination. Only for patients with highly impaired renal function (creatinine clearance less than 20 mL/minute) was the recovery in the urine less than complete. PMID:1743921
Evaluation of liver function using gadoxetate disodium (Gd-EOB-DTPA) enhanced MR imaging
NASA Astrophysics Data System (ADS)
Yamada, Akira; Hara, Takeshi; Li, Feng; Doi, Kunio
Indocyanine green (ICG) is widely used for its clearance test in the evaluation of liver function. Gadoxetate disodium (Gd-EOB-DTPA) is a targeted MR contrast agent partially taken up by hepatocytes. The objective of this study was to evaluate the feasibility of an estimation of the liver function corresponding to plasma disappearance rate of indocyanine green (ICG-PDR) by use of the signal intensity of the liver alone in Gd-EOB-DTPA enhanced MR imaging (EOB-MRI). We evaluated fourteen patients who had EOB-MRI and ICG clearance test within 1 month. 2D-GRE T1 weighted images were obtained at pre contrast, 3 min (equilibrium phase) and 20 min (hepatobiliary phase) after the intravenous administration of Gd-EOB-DTPA, and the mean signal intensity of the liver was measured. The correlation between ICG-PDR and many parameters derived from the signal intensity of the liver in EOB-MRI was evaluated. The correlation coefficient between ICG-PDR and many parameters derived from the signal intensity of the liver in EOBMRI was low and not significant. The estimation of the liver function corresponding to ICG-PDR by use of the signal intensity of the liver alone in EOB-MRI would not be reliable.
Aerosol penetration ratio: a new index of ventilation
Sirr, S.A.; Elliott, G.R.; Regelmann, W.E.; Juenemann, P.J.; Morin, R.L.; Boudreau, R.J.; Warwick, W.J.; Loken, M.K.
Superimposition of nuclear medicine scintigrams and standard radiographs provides a unique opportunity for merging functional information intrinsic to nuclear medicine images with the high resolution anatomic detail of radiographs. A newly developed image processing system allows the merging of two separate films of greatly varying sizes to form a single composite image. Subsequent quantitative analysis of the composite image may be performed. Using the superimposition technique, (/sup 99m/Tc)DTPA aerosol ventilation scans (4.5 X 4.5 cm) were superimposed upon chest radiographs (35.6 X 43.2 cm) in 17 cystic fibrosis (CF) patients. Subsequent quantification of the area of nuclear scan ventilation and the radiographic lung area was then performed. A new quantitative radiologic index of ventilation, the aerosol penetration ratio (APR), was defined. Linear correlation of aerosol penetration ratio with residual volume (RV) as percent of total lung capacity (TLC) measured by body plethysmography was good. We conclude that the APR has validity as a physiologic parameter which localized regional excessive residual volume and correlates well with RV/TLC, the gold standard pulmonary function index of obstructive airway disease.
Accurate numerical schemes have been developed for simulation of the condensation/evaporation processes with vapor conservation for a single component aerosol. These have been incorporated in modules which allow simulation of aerosol dynamics in models for dispersion and transpor...
This report summarizes progress in measuring the optical properties of aerosols and in relating aerosol characteristics to visibility reduction made in the author's laboratory during the period 1965-1971. An instrument, the integrating nephelometer, which measures the scattering ...
Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...
Peptide transporter DtpA has two alternate conformations, one of which is promoted by inhibitor binding
Bippes, Christian A.; Ge, Lin; Meury, Marcel; Harder, Daniel; Ucurum, Z÷hre; Daniel, Hannelore; Fotiadis, Dimitrios; M³ller, Daniel J.
Peptide transporters (PTRs) of the large PTR family facilitate the uptake of di- and tripeptides to provide cells with amino acids for protein synthesis and for metabolic intermediates. Although several PTRs have been structurally and functionally characterized, how drugs modulate peptide transport remains unclear. To obtain insight into this mechanism, we characterize inhibitor binding to the Escherichia coli PTR dipeptide and tripeptide permease A (DtpA), which shows substrate specificities similar to its human homolog hPEPT1. After demonstrating that Lys[Z-NO2]-Val, the strongest inhibitor of hPEPT1, also acts as a high-affinity inhibitor for DtpA, we used single-molecule force spectroscopy to localize the structural segments stabilizing the peptide transporter and investigated which of these structural segments change stability upon inhibitor binding. This characterization was done with DtpA embedded in the lipid membrane and exposed to physiologically relevant conditions. In the unbound state, DtpA adopts two main alternate conformations in which transmembrane ?-helix (TMH) 2 is either stabilized (in ?43% of DtpA molecules) or not (in ?57% of DtpA molecules). The two conformations are understood to represent the inward- and outward-facing conformational states of the transporter. With increasing inhibitor concentration, the conformation characterized by a stabilized TMH 2 becomes increasingly prevalent, reaching ?92% at saturation. Our measurements further suggest that Lys[Z-NO2]-Val interacts with discrete residues in TMH 2 that are important for ligand binding and substrate affinity. These interactions in turn stabilize TMH 2, thereby promoting the inhibited conformation of DtpA. PMID:24082128
Prescott, Donald S. (Shelley, ID); Schober, Robert K. (Midwest City, OK); Beller, John (Idaho Falls, ID)
An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.
Improved solid aerosol generator
Prescott, D.S.; Schober, R.K.; Beller, J.
An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.
Prescott, D.S.; Schober, R.K.; Beller, J.
An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.
The Modal Aerosol Dynamics (MAD) model is a computationally efficient model for solving the General Dynamics Equation of Aerosols (GDE) (Friedlander, 1977). The simplifying assumption in the model is that aerosol size distributions can be approximated by overlapping modes, each r...
Discrimination of aerosol types and absorbing aerosols
Victoria E. Cachorro; Natalia Prats; Sandra I. Mogo; Carlos Toledano; Alberto J. Berjon; Elena Montilla; Benjamin Torres; Ruben Rodrigo; David Fuertes; Ramiro Gonzalez; Yasmine S. Bennouna; Angel de Frutos
Aerosol particles are one of the most variable components in the Earth's atmosphere, affecting the radiative balance and influencing the climate system by direct and indirect effects. To evaluate these two effects the optical-radiative properties of aerosols are the key elements and hence the necessity of their retrieval. Many detailed campaigns of measurements have been carried out in the past
Effects of the Magnetic Resonance Imaging Contrast Agent Gd-DTPA on Plant Growth and Root Imaging in Rice
Liu, Binmei; Wang, Qi; Ni, Xiaoyu; Dong, Yaling; Zhong, Kai; Wu, Yuejin
Although paramagnetic contrast agents have a wide range of applications in medical studies involving magnetic resonance imaging (MRI), these agents are seldom used to enhance MRI images of plant root systems. To extend the application of MRI contrast agents to plant research and to develop related techniques to study root systems, we examined the applicability of the MRI contrast agent Gd-DTPA to the imaging of rice roots. Specifically, we examined the biological effects of various concentrations of Gd-DTPA on rice growth and MRI images. Analysis of electrical conductivity and plant height demonstrated that 5 mmol Gd-DTPA had little impact on rice in the short-term. The results of signal intensity and spin-lattice relaxation time (T1) analysis suggested that 5 mmol Gd-DTPA was the appropriate concentration for enhancing MRI signals. In addition, examination of the long-term effects of Gd-DTPA on plant height showed that levels of this compound up to 5 mmol had little impact on rice growth and (to some extent) increased the biomass of rice. PMID:24945975
Hepatic kinetics and magnetic resonance imaging of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dogs.
Benness, G; Khangure, M; Morris, I; Warwick, A; Burrows, P
This complex study was designed to measure the transport and excretion characteristics of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dog's livers following bolus and infusion. Simultaneous T1 magnetic resonance imaging was performed to measure maximum signal enhancement. Anaesthetized dogs had cannulation of the common bile duct and urinary bladder for collections and cannulation of the femoral artery and vein for monitoring, blood sampling and infusion. Gd-EOB-DTPA was administered by bolus (range 12.5-200 mumol/kg) and infusion (range 0.4-6.4 mumol/min per kg). An hepatic transport maximum 0.09-0.15 mumol/min/kg was achieved with a blood concentration of 0.03-0.06 mumol/mL. Marked hepatic affinity for Gd-EOB-DTPA was demonstrated with measurements of liver concentration. Maximum T1 signal enhancement was achieved with blood Gd-EOB-DTPA concentration of 0.02-0.03 mumol/mL and a liver concentration of 1-2 mumol/g. The transport maximum for Gd-EOB-DTPA in the dog was similar to that for ipodate and iodipamide and effective imaging was achieved with sub-maximal doses. The maximum signal enhancement at blood concentrations less than required for maximum transport suggest a wide latitude for effective clinical imaging. PMID:8373327
Climate forcing by stratospheric aerosols
NASA Technical Reports Server (NTRS)
Lacis, Andrew; Hansen, James; Sato, Makiko
It is illustrated how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosols size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, r(eff). If r(eff) is greater than about 2 microns, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a surface heating. The aerosol climate forcing is less sensitive to other characteristics of the size distribution, the aerosol composition, and the altitude of the aerosols. Thus stratospheric aerosol forcing can be defined accurately from measurements of aerosol extinction over a broad wavelength range.
Aerosol collection characteristics of ambient aerosol samplersĀ
Ortiz, Carlos A
particle size but also wind speed and direction (2), and to a limited extent upon air sampling rate. In field applications, characterizat1on of aerosol concentrat1on 1s difficult when the upper size 11mit of the sampler is variable. Also, since the Hi... multistage 1mpin- ger, and an Andersen cascade impactor. Watson (9) developed a semi-empir1cal theory of the errors due to anisokinetic sampling of aerosols. 0uantitative sampling of an aerosol in a moving stream was assumed to be obtained for isokinetic...
Functional Fecal Retention Visualized by 111In-DTPA Colon Transit Scintigraphy.
Infante, Jose Rafael; Rayo, Juan I; Serrano, Justo; Dominguez, Maria L; Garcia, Lucia; Moreno, Manuel
Constipation is an extremely common problem in children, varying from mild and short-lived to severe and chronic. Chronic constipation is a serious childhood condition and requires further investigation, including blood test, colonoscopy, radio-opaque marker study, and/or scintigraphy. We present small bowel and colon transit scintigraphy of a 14-year-old girl with history of chronic constipation, abdominal pain, weight loss, and poor response to medical treatment. After oral administration of In-DTPA in water, planar and SPECT/CT images showed normal small bowel transit time and functional fecal retention in colon transit study. PMID:25706788
Enhancement characteristics of liver metastases, hepatocellular carcinomas, and hemangiomas with Gd-EOB-DTPA: preliminary results with dynamic MR imaging.
Reimer, P; Rummeny, E J; Daldrup, H E; Hesse, T; Balzer, T; Tombach, B; Peters, P E
Our objective was to study Gd-EOB-DTPA for the characterization of focal liver lesions by means of dynamic MR imaging. A double-blind and randomized dose-ranging phase-2 clinical trial was performed in 31 patients (liver metastases n = 23, hepatocellular carcinoma n = 4, and hemangioma n = 4) at a field strength of 1.0 Tesla. Gd-EOB-DTPA (Schering AG, Berlin, Germany) was administered as an IV bolus (12.5, 25, or 50 micromol/kg body weight) with dynamic T1-weighted MRI during the distribution and cellular uptake of the contrast agent at multiple time points up to 45 min post contrast. Dynamic changes in tumor signal intensity, tumor-liver contrast, enhancement patterns, side effects, and adverse events were evaluated. Monitoring of vital signs revealed no significant changes during bolus injection of Gd-EOB-DTPA. Liver metastases demonstrated an inhomogeneous uptake of Gd-EOB-DTPA during the distribution phase with a washout effect on delayed images > 3 min and highest tumor-liver contrast 20 and 45 min post contrast. Hepatocellular carcinomas showed prolonged enhancement as compared with metastases and hemangiomas. Hemangiomas exhibited an early peripheral-nodular enhancement with subsequent partial or complete filling, persisting enhancement < 10 min following injection of Gd-EOB-DTPA, and delayed washout as compared with liver metastases. Initial clinical experience suggests that Gd-EOB-DTPA as a bolus injectable hepatobiliary MR contrast agent may offer useful features for the characterization of focal liver lesions. PMID:9038130
Gd-DTPA l Cystine Bisamide Copolymers as Novel Biodegradable Macromolecular Contrast Agents for MR Blood Pool Imaging
Todd L. Kaneshiro; Tianyi Ke; Eun-Kee Jeong; Dennis L. Parker; Zheng-Rong Lu
\\u000a PurposeĀĀThe purpose of this study was to synthesize biodegradable Gd-DTPA l-cystine bisamide copolymers (GCAC) as safe and effective, macromolecular contrast agents for magnetic resonance imaging (MRI)\\u000a and to evaluate their biodegradability and efficacy in MR blood pool imaging in an animal model.\\u000a \\u000a \\u000a \\u000a MethodsĀĀThree new biodegradable GCAC with different substituents at the cystine bisamide [R = H (GCAC), CH2CH2CH3 (Gd-DTPA l-cystine
Atmospheric Science Data Center
... UAE 2 ĀAerosol Versioning MISR-retrieved aerosol optical depths are "Stage-2 Validated," whereas the MISR ... . Kahn , R., B. Gaitley, J. Martonchik, D. Diner, K. Crean, and B. Holben, 2005a, MISR global aerosol optical depth validation ...
Review of 8 years of experience with Infanrix hexa (DTPa-HBV-IPV/Hib hexavalent vaccine).
Zepp, Fred; Schmitt, Heinz-Josef; Cleerbout, Jan; Verstraeten, Thomas; Schuerman, Lode; Jacquet, Jeanne-Marie
Combination vaccines that include multiple antigens within one formulation are now widely accepted as an effective means of eliciting protection against several diseases at the same time. Owing to improvements in quality and convenient modes of administration, they have become part of routine pediatric practice. Hexavalent vaccines, including diphtheria, tetanus, pertussis, hepatitis B, polio and Haemophilus influenzae type b antigens represent the latest advance in the development of combination vaccines. Over 8 years since its first licensure, this review looks at the immunogenicity, efficacy and safety profile of the only hexavalent pediatric vaccine currently in use--Infanrix hexa (diphtheria, tetanus, acellular pertusis-hepatitis B virus-inactivated poliovirus vaccine/Haemophilus influenzae type b vaccine [DTPa-HBV-IPV/Hib]; GlaxoSmithKline Biologicals, Rixensart, Belgium)--through published clinical trials and postmarketing surveillance data. These data show DTPa-HBV-IPV/Hib to be highly immunogenic and well tolerated across a range of different primary and booster vaccination schedules, as well as when administered concomitantly with other licensed vaccines (e.g., pneumococcal conjugate vaccine). Additional issues surrounding the use of hexavalent vaccines are also reviewed. PMID:19485747
Topical Drug Delivery in Chronic Rhinosinusitis Patients before and after Sinus Surgery Using Pulsating Aerosols
M÷ller, Winfried; Schuschnig, Uwe; Celik, G³lnaz; M³nzing, Wolfgang; Bartenstein, Peter; Hõussinger, Karl; Kreyling, Wolfgang G.; Knoch, Martin
Objectives Chronic rhinosinusitis (CRS) is a common chronic disease of the upper airways and has considerable impact on quality of life. Topical delivery of drugs to the paranasal sinuses is challenging, therefore the rate of surgery is high. This study investigates the delivery efficiency of a pulsating aerosol in comparison to a nasal pump spray to the sinuses and the nose in healthy volunteers and in CRS patients before and after sinus surgery. Methods 99mTc-DTPA pulsating aerosols were applied in eleven CRSsNP patients without nasal polyps before and after sinus surgery. In addition, pulsating aerosols were studied in comparison to nasal pump sprays in eleven healthy volunteers. Total nasal and frontal, maxillary and sphenoidal sinus aerosol deposition and lung penetration were assessed by anterior and lateral planar gamma camera imaging. Results In healthy volunteers nasal pump sprays resulted in 100% nasal, non-significant sinus and lung deposition, while pulsating aerosols resulted 61.3+/-8.6% nasal deposition and 38.7% exit the other nostril. 9.7+/-2.0 % of the nasal dose penetrated into maxillary and sphenoidal sinuses. In CRS patients, total nasal deposition was 56.7+/-13.3% and 46.7+/-12.7% before and after sinus surgery, respectively (p<0.01). Accordingly, maxillary and sphenoidal sinus deposition was 4.8+/-2.2% and 8.2+/-3.8% of the nasal dose (p<0.01). Neither in healthy volunteers nor in CRS patients there was significant dose in the frontal sinuses. Conclusion In contrast to nasal pump sprays, pulsating aerosols can deliver significant doses into posterior nasal spaces and paranasal sinuses, providing alternative therapy options before and after sinus surgery. Patients with chronic lung diseases based on clearance dysfunction may also benefit from pulsating aerosols, since these diseases also manifest in the upper airways. PMID:24040372
Conversion of arterial input functions for dual pharmacokinetic modeling using Gd-DTPA/MRI and 18F-FDG/PET.
Poulin, Eric; Lebel, Rķjean; Croteau, Etienne; Blanchette, Marie; Tremblay, Luc; Lecomte, Roger; Bentourkia, M'hamed; Lepage, Martin
Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) in MRI, into a (18)F-fluorodeoxyglucose ((18)F-FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98-Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (K(trans)), the extravascular-extracellular volume fraction (?(e)), and the blood volume fraction (?(p)) calculated with the Gd-DTPA AIF and the Gd-DTPA AIF converted from (18)F-FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with (18) F-FDG AIF and with (18) F-FDG AIF obtained from Gd-DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI-PET pharmacokinetic modeling in small animal models. PMID:22570280
Synthesis of novel tetravalent galactosylated DTPA-DSPE and study on hepatocyte-targeting efficiency in vitro and in vivo
Xiao, Yan; Zhang, Huafang; Zhang, Zhaoguo; Yan, Mina; Lei, Ming; Zeng, Ke; Zhao, Chunshun
For the purposes of obtaining a hepatocyte-selective drug delivery system, a novel tetravalent galactosylated diethylenetriaminepentaacetic acid-distearoyl phosphatidylethanolamine (4Gal-DTPA-DSPE) was synthesized. The chemical structure of 4Gal-DTPA-DSPE was confirmed by proton nuclear magnetic resonance and mass spectrometry. The four galactose-modified liposomes (4Gal-liposomes) were prepared by thin-film hydration method, then doxorubicin (DOX) was encapsulated into liposomes using an ammonium sulfate gradient loading method. The liposomal formulations with 4Gal-DTPA-DSPE were characterized by laser confocal scanning microscopy and flow cytometry analysis, and the results demonstrated that the 4Gal-liposomes facilitated the intracellular uptake of DOX into HepG2 cells via asialoglycoprotein receptor-mediated endocytosis. Cytotoxicity assay showed that the cell proliferation inhibition effect of 4Gal-liposomes was higher than that of the conventional liposomes without the galactose. Additionally, pharmacokinetic experiments in rats revealed that the 4Gal-liposomes displayed slower clearance from the systemic circulation compared with conventional liposomes. The organ distributions in mice and the study on frozen sections of liver implied that the 4Gal-liposomes enhanced the intracellular uptake of DOX into hepatocytes and prolonged the circulation. Taken together, these results indicate that liposomes containing 4Gal-DTPA-DSPE have great potential as drug delivery carriers for hepatocyte-selective targeting. PMID:23976853
Magnetic Resonance Imaging of Acute Reperfused Myocardial Infarction: Intraindividual Comparison of ECIII-60 and Gd-DTPA in a Swine Model
Jin Jiyang; Teng Gaojun [Zhongda Hospital of Southeast University, Department of Radiology (China); Feng Yi; Wu Yanping [Zhongda Hospital of Southeast University, Department of Cardiology (China); Jin Qindi [Zhongda Hospital of Southeast University, Department of Radiology (China); Wang Yu [Zhongda Hospital of Southeast University, Department of Cardiology (China); Wang Zhen [Zhongda Hospital of Southeast University, Department of Anaesthesiology (China); Lu Qin [Zhongda Hospital of Southeast University, Department of Radiology (China); Jiang Yibo [Zhongda Hospital of Southeast University, Department of Cardiology (China); Wang Shengqi; Chen Feng [Zhongda Hospital of Southeast University, Department of Radiology (China); Marchal, Guy; Ni Yicheng [University Hospitals, University of Leuven, Department of Radiology (Belgium)], E-mail: email@example.com
Purpose. To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI). Methods. Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining. Results. A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80x smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining. Conclusion. Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.
NSDL National Science Digital Library
Rex Roettger
Students will use real satellite data to determine 1) where the greatest concentrations of aerosols are located during the course of a year in the tropical Atlantic region and 2) their source of origin. This is an inquiry-style lesson where students pull real aerosol data and attempt to identify trends among data sets.
Direct Aerosol Forcing Uncertainty
Mccomiskey, Allison
Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.
Portable Aerosol Contaminant Extractor
Duane C. Carlson; John J. DeGange; Paula Cable-Dunlap
A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.
Portable Aerosol Contaminant Extractor
Carlson, Duane C. (N. Augusta, SC); DeGange, John J. (Aiken, SC); Cable-Dunlap, Paula (Waynesville, NC)
A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.
The purpose of this project was to design, construct, calibrate, and field test a mobile ambient particulate matter sampler (Wide Range Aerosol Classifier) to collect size-classified samples of large aerosol particles. The sampler design was based on a similar stationary sampling...
Direct Aerosol Forcing Uncertainty
Mccomiskey, Allison
Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.
Atmospheric Science Data Center
... across the deserts of Mali, Niger and Chad, while in southern Africa, this is the least hazy time of year. During June through ... and November thick aerosol cover is limited to portions of southern Africa and the Congo, but moderately high aerosol optical thickness ...
An intensive field study of ambient aerosols was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for aerosol and gaseous pollutants, (2) a network of high volume samplers ...
Ganges valley aerosol experiment.
Kotamarthi, V.R.; Satheesh, S.K. (Environmental Science Division); (Indian Institute of Science, Bangalore, India)
In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.
Spaceborne Observations of Aerosols
Y. J. Kaufman; D. Tanre; J. A. Coakley; R. S. Fraser
As early as 1963, photographs of the twilight horizon from the Vostok-6 spaceship were used by G. V. Rozenberg and V. V. Nikolaeva-Tereshkova to derive profiles of stratospheric aerosols. The launch of the ATS III satellite in 1967 sparked interest in using satellites to observe aerosol emission, transport, and their effects on climate, precipitation and health. The first use of
Relaxivity of Gd-EOB-DTPA in the normal and biliary obstructed guinea pig.
Shuter, B; Wang, S C; Roche, J; Briggs, G; Pope, J M
After injection of Gd-EOB-DTPA, T1 and T2 were determined on a clinical MR scanner (1.5 T) in the liver and kidneys of sacrificed but intact guinea pigs with normal and obstructed biliary systems and in bile, urine, and blood collected postmortem. Tissue [Gd] was determined by radioassay of 153Gd and relaxivities (R1 and R2; units of s(-1) x mmol(-1) x kg) of Gd-EOB-DTPA calculated. Compared with R1 in 2% agarose gel (4.49 +/- 0.03), in normal animals R1 was increased in liver (9.3 +/- 0.5), similar in kidney cortex (4.1 +/- 0.5), but reduced in kidney medulla (2.5 +/- 0.4) and papilla (2.7 +/- 0.4). Chronic biliary obstruction did not change R1 in liver (9.7 +/- 4.3) but reduced R1 further in kidney tissues (1.0-0.4). In normal animals, R2 values of all tissues (9.5-18.4) were greater than R2 in gel (5.72 +/- 0.12). Biliary obstruction possibly elevated R2 in liver (40.1 +/- 63.5), severely depressed R2 in kidney cortex (-4.2 +/- 6.2) and medulla (-2.3 +/- 5.4), and reduced R2 in papilla (5.4 +/- 4.6). Obstruction had little effect on R1 and R2 in bile and urine. Water content, macromolecular binding, microviscosity, compartmentalization, and susceptibility effects can readily account for the R1 and R2 observed in liver and kidney. Negative R2 could be a result of several factors, including reduced endogenous magnetic field gradients due to "susceptibility matching" as [Gd] increased, changes in tissue T2 with period of ligation, or a physiological effect of EOB-DTPA. These results show that disease can alter both R1 and R2 from their values in normal tissues. PMID:9702887
Added value of Gd-EOB-DTPA-enhanced Hepatobiliary phase MR imaging in evaluation of focal solid hepatic lesions
Background Correct characterization of focal solid hepatic lesions has always been a challenge and is of great diagnostic and therapeutic relevance. The purpose of this study was to determine the added value of hepatobiliary phase images in Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for differentiating focal solid hepatic lesions. Methods In this retrospective trial 84 consecutive patients underwent Gd-EOB-DTPA-enhanced MR examinations. MRI was conducted for 64 patients with malignant focal hepatic lesions (34 hepatocellular carcinoma (HCC), 30 metastases) and for 20 patients with benign hepatic lesions (14 focal nodular hyperplasia (FNH), 3 adenoma, 3 hemangioma). Five radiologists independently reviewed three sets of MR images by means of a 5-point confidence scale from score 1 (definitely benign) to score 5 (definitely malignant): set 1: unenhanced images; set 2: unenhanced and Gd-EOB-DTPA-enhanced dynamic images; set 3: hepatobiliary phase images in addition to set 2. Accuracy was assessed by the alternative free-response receiver operating characteristic curve (Az) and the index of diagnostic performance was calculated. Results Diagnostic accuracy was significantly improved by the addition of Gd-EOB-DTPA-enhanced dynamic images: Az in set 1 was 0.708 and 0.833 in set 2 (P?=?0.0002). The addition of hepatobiliary phase images increased the Az value to 0.941 in set 3 (set 3 vs set 2, P?0.0001; set 3 vs set 1, P?0.0001). The index of diagnostic performance was lowest in set 1 (45%), improved in set 2 (71%), and highest in set 3 (94%). Conclusions Hepatobiliary phase images obtained after Gd-EOB-DTPA-enhanced dynamic MRI improve the differentiation of focal solid hepatic lesions. PMID:24289722
Assessment of Clinical Signs of Liver Cirrhosis Using T1 Mapping on Gd-EOB-DTPA-Enhanced 3T MRI
Haimerl, Michael; Verloh, Niklas; Zeman, Florian; Fellner, Claudia; M³ller-Wille, Renķ; Schreyer, Andreas G.; Stroszczynski, Christian; Wiggermann, Philipp
Objectives To assess the differences between normal and cirrhotic livers by means of T1 mapping of liver parenchyma on gadoxetic acid (Gd-EOB-DTPA)-enhanced 3 Tesla (3T) MR imaging (MRI). Methods 162 patients with normal (n = 96) and cirrhotic livers (n = 66; Child-Pugh class A, n = 30; B, n = 28; C, n = 8) underwent Gd-EOB-DTPA-enhanced 3T MRI. To obtain T1 maps, two TurboFLASH sequences (TI = 400 ms and 1000 ms) before and 20 min after Gd-EOB-DTPA administration were acquired. T1 relaxation times of the liver and the reduction rate between pre- and post-contrast enhancement images were measured. Results The T1 relaxation times for Gd-EOB-DTPA-enhanced MRI showed significant differences between patients with normal liver function and patients with Child-Pugh class A, B, and C (p < 0.001). The T1 relaxation times showed a constant significant increase from Child-Pugh class A up to class C (Child-Pugh class A, 335 ms ▒ 80 ms; B, 431 ms ▒ 75 ms; C, 557 ms ▒ 99 ms; Child-Pugh A to B, p < 0.001; Child-Pugh A to C, p < 0.001; Child-Pugh B to C, p < 0.001) and a constant decrease of the reduction rate of T1 relaxation times (Child-Pugh class A, 57.1% ▒ 8.8%; B, 44.3% ▒ 10.2%, C, 29.9% ▒ 6.9%; Child-Pugh A to B, p < 0.001; Child-Pugh A to C,p < 0.001; Child-Pugh B to C, p < 0.001). Conclusion Gd-EOB-DTPA-enhanced T1 mapping of the liver parenchyma may present a useful method for determining severity of liver cirrhosis. PMID:24392025
In vivo stability and excretion of gadodiamide (GdDTPA-BMA), a hydrophilic gadolinium complex used as a contrast enhancing agent for magnetic resonance imaging
P. T. Normann; P. A. Hals
SummaryĀĀThe stability and excretion of [14C]-gadodiamide (GdDTPA-BMA) was studied in male rats after i.v. injection of 0.3 mmol\\/kg [14C]-GdDTPA-BMA (Gd-diethylenetriaminepentaacetic-acid-bis-methylamide) formulated as gadodiamide injection (OMNISCAN«, Nycomed Imaging AS. Oslo, Norway). Samples of blood and urine\\u000a obtained within 60 min and 6 h postdosing, respectively, were analyzed for radiolabeled compounds. Analysis of GdDTPA-BMA\\u000a in high and low molecular weight fractions of
7, 55535593, 2007 Nitrate aerosols
Paris-Sud XI, Universitķ de
ACPD 7, 5553Ł5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Discussions Nitrate aerosols today and in 2030: importance relative to other aerosol species and tropospheric, 5553Ł5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Introduction
Climate forcing by stratospheric aerosols
Andrew Lacis; James Hansen; Makiko Sato
We illustrate how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosol size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, reff.If reff is greater than about 2 ?m, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a
Absorption Properties of Arctic Aerosol
R. Gao; J. P. Schwarz; D. A. Lack; R. Bahreini; K. D. Froyd; S. Lance; J. R. Spackman; W. Laurel A; D. W. Fahey; A. M. Middlebrook; P. R. Veres; C. A. Brock
The Arctic region is highly sensitive to global climate change. Aerosols, especially their absorption properties, have a significant potential to affect climate forcing. Accurate knowledge of aerosol absorption is critical to derive a complete set of aerosol optical properties from remote radiance measurements. We present airborne observations obtained during the NOAA-sponsored Aerosol Radiation and Cloud Processes affecting Arctic Climate (ARCPAC)
Climatic Effects of Atmospheric Aerosols
James E. Hansen; Andrew A. Lacis; Pauthon Lee; Wei-Chyung Wang
It is shown quantitatively how radiative climatic forcing by aerosols depends on the physical properties of the aerosols. The special case of atmospheric aerosols produced by volcanic explosions is considered, and evidence is presented which indicates that even the simple climate models available today may be able to capture some of the basic effects of aerosols on global climate. Possible
Paramagnetic agents as tracers in magnetic resonance imaging. Extrapolations from Gd-DTPA to everything.
Koenig, S H
The range of compounds, both paramagnetic and ferromagnetic, with potential utility as tracers for enhancing contrast in magnetic resonance imaging is very large. Fortunately, the changes in 1/T1 and 1/T2 of water protons in solution--and ultimately in tissue--induced by these agents arise from variations of only a few physical parameters. In the present work, we first consider the properties of Gd-DTPA2- in solution in some detail, including its effects on both inner and outer sphere relaxation of solvent protons. Then, by varying one or another physical parameter, we derive behavior that characterizes several classes of contrast agents with markedly different properties. These include small macrocycles, such as Gd-DOTA-; larger complexes, including oligomers and conjugates of small paramagnetic complexes with protein; magnetized particles, such as magnetite, as a function of their size; and highly anisotropic porphyrin compounds. Predictions are compared with data from the literature. PMID:1966965
Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas. Aerosol particles
Beaucage, Gregory
1 Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas being clouds with water droplet sizes on the order of 5 to 50 micron suspended in air. Nanomaterials can of nanomaterials since most aerosol synthetic approaches are amenable to continuous production and since aerosols
{[GdAg 2(dtpa)(H 2O)] Ę 3H 2O} n : the first 2D Gd¢Ag coordination polymer with Ag¢Ag interaction
Bin Zhao; Xiao-Yan Chen; Wen-Zhen Wang; Peng Cheng; Bin Ding; Dai-Zheng Liao; Shi-Ping Yan; Zong-Hui Jiang
A novel 4d¢4f coordination polymer {[GdAg2(dtpa)(H2O)]Ę3H2O}n (1) (dtpa=diethylenetriamine pentaacetate) was synthesized and characterized by magnetic and EPR studies. Its one-dimensional Gd¢Ag ladder-like chains built upon tetranuclear rings are further connected by Ag¢O bonds and Ag¢Ag interactions to form a lamellar 2D packing.
Tracking World Aerosol Hazards
NSDL National Science Digital Library
Worldwide patterns and sources of aerosols are analyzed and evaluated for potential hazards to aircraft safety. Using aerosol index maps created from data gathered by the TOMS instrument, student groups will analyze and compare aerosol data from either eight consecutive or eight random days. Each group will graph the data, rank the hazard level of their study area and analyze the patterns and probable causes of those aerosols. Directions and materials are included for classes with computer access and for those without computer access. The URL opens to the investigation directory, with links to teacher and student materials, lesson extensions, resources, teaching tips, and assessment strategies. Note that this is the last of three investigations found in the Grades 5-8 Module 1 of Mission Geography. The Mission Geography curriculum integrates data and images from NASA missions with the National Geography Standards. Each of the three investigations in Module 1, while related, can be done independently.
NASA Technical Reports Server (NTRS)
Kahn, Ralph A.
AeroCom is an open international initiative of scientists interested in the advancement of the understanding of global aerosol properties and aerosol impacts on climate. A central goal is to more strongly tie and constrain modeling efforts to observational data. A major element for exchanges between data and modeling groups are annual meetings. The meeting was held September 20 through October 2, 1014 and the organizers would like to post the presentations.
Monodisperse aerosol generator
Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)
An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.
Efficacy of orally administered amphipathic polyaminocarboxylic acid chelators for the removal of plutonium and americium: comparison with injected Zn-DTPA in the rat.
Miller, Scott C; Liu, Gang; Bruenger, Fred W; Lloyd, Ray D
Chelators are used to promote excretion of actinides and some other metals, but few are orally effective. The relative efficacies of orally administered triethylenetetraminepentaacetic acids (TT) with varying lipophilic properties on the removal of 241Am and 239Pu and comparison with parenteral Zn-DTPA was determined. The actinides were administered to adult rats 2 weeks prior to initiation of 30 d of chelation treatment. The TT compounds were given orally while Zn-DTPA was given twice weekly by injection. Total body content of 241Am was measured before and during the treatment period and organ contents of 241Am and 239Pu were measured at the end of the study. Significant reductions in 241Am occurred within the first week, with Zn-DTPA being the most effective. By 3 weeks, the most lipophilic chelator, C22TT was as effective as Zn-DTPA. After 30 d, reductions in organ content of 239Pu and 241Am directly correlated with increasing lipophilicity of the TT chelators. Oral C22TT was as effective as injected Zn-DTPA in liver and bone, the major organs of actinide deposition. The removal of 239Pu from the liver and reduction of redeposition of 239Pu in newly formed bone by C22TT was confirmed by neutron-induced autoradiographs. The amphipathic TT chelators may be useful as orally administered alternatives to current parenteral DTPA for the removal of actinide elements from the body, particularly for longer-term therapeutic applications. PMID:16332916
RACORO aerosol data processing
Elisabeth Andrews
The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.
[Dynamic scintigraphy of the kidney using 99m-Tc-DTPA before and after extracorporeal shock wave lithotripsy].
Markovi?, S; Butorajac, J; Ajdinovi?, B; Pucar, D; Zogovi?, J
The results of dynamic scintigraphy of the kidneys using 99mTc-DTPA that is glomerular radiopharmaceutic in patients before and after ESWL (extracorporeal shock wave lithotripsy) are presented. Investigation was performed in 22 patients--in 8 patients immediately before ESWL, 7 days and 3 months later, and in 14 patients before and 7 days after ESWL. The time alteration of the achievement of the maximal values of radiorenographic curve obtained by dynamic scintigraphy (Tmax), as the alteration of separate clearance (SCI) counted as an integral below the other phase of renographic curve. No significant differences were observed in the values of separate clearance before and after ESWL, while Tmax was significantly reduced 3 months after ESWL (p < 0.05). Our results indicated the improvement of glomerular filtration of the kidneys 3 months after ESWL (faster passing of DTPA through the treated kidney). PMID:11548551
Validation of an alternative radiochemical purity method for [99mTc]pentetate ([99mTc]DTPA).
Borrķ, MarĒa Candela; Tesßn, Fiorella C; Leonardi, Natalia M; Zubillaga, Marcela B; Salgueiro, M Jimena
[(99m)Tc]pentetate ([(99m)Tc]DTPA) is the most commonly used radiopharmaceutical renography agent. The aim of this work was to validate an alternative method for assessing [(99m)Tc]DTPA radiochemical purity (RCP), according to the ICH Q2(R1) guidance: "Validation of Analytical Procedures". The proposed method is composed of two chromatographic systems. System A is a miniaturized system of thin layer chromatography (TLC) silica gel impregnated aluminum strips as stationary phase (SP) and distilled water as mobile phase (MP). System B consists of Whatman 1 paper strips as SP and methyl ethyl ketone as MP. Results indicate that the proposed RCP method has been validated, as it is specific, precise, accurate, linear and robust. Therefore, it can be used as an alternative method for RCP quality control purposes and as stability indicator as well. PMID:24140984
Atypical Findings of Focal Nodular Hyperplasia with Gadoxetic Acid (Gd-EOB-DTPA)-Enhanced Magnetic Resonance Imaging
Yoon, Jung-Hee; Kim, Ji-Yeon
We report two cases of focal nodular hyperplasia in patients following gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging confirmed with histopathology. These cases showed an atypical pattern during the delayed-hepatobiliary phase after the injection of gadoxetic acid. One case showed a total defect, and the other showed a peripheral ring-like enhancement without a visible central scar, mimicking hepatocellular carcinoma. The pathologic examination demonstrated that the two lesions were focal nodular hyperplasia. PMID:24693305
Quantitative Evaluation of Enhancement Patterns in Focal Solid Liver Lesions with Gd-EOB-DTPA-Enhanced MRI
Haimerl, Michael; Wõchtler, Max; Zeman, Florian; Verloh, Niklas; Platzek, Ivan; Schreyer, Andreas Georg; Stroszczynski, Christian; Wiggermann, Philipp
Purpose The objective was to investigate the dynamic enhancement patterns in focal solid liver lesions after the administration of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) by means of dynamic magnetic resonance imaging (MRI) including hepatobiliary phase (HP) images 20 min after Gd-EOB-DTPA administration. Materials and Methods Non-enhanced T1/T2-weighted as well as dynamic magnetic resonance (MR) images during the arterial phase (AP), the portal venous phase (PVP), the late phase (LP), and the HP (20 min) were obtained from 83 patients (54 male, 29 female, mean age 62.01 years) with focal solid liver lesions. MRI was conducted by means of a 1.5-T system for 63 patients with malignant liver lesions (HCCs: n?=?34, metastases: n?=?29) and for 20 patients with benign liver lesions (FNH lesions: n?=?14, hemangiomas: n?=?3, adenomas: n?=?3). For quantitative analysis, signal-to-noise ratios (SNR), contrast enhancement ratios (CER), lesion-to-liver contrast ratios (LLC), and signal intensity (SI) ratios were measured. Results The SNR of liver parenchyma significantly increased in each dynamic phase after Gd-EOB-DTPA administration compared to the SNR of non-enhanced images (p<0.001). The CER of HCCs and metastases significantly decreased between LP and HP images (p?=?0.0011, p<0.0001). However, FNH lesions did not show any significant difference, whereas an increased CER was found in hemangiomas. The mean LLCs of FNH lesions were significantly higher than those of HCCs and metastases. The LLC values of hemangiomas remained negative during the entire time course, whereas the LLC of adenomas indicated hyperintensity from the AP to the LP. Furthermore, adenomas showed hypointensity in HP images. Conclusion Gd-EOB-DTPA-enhanced MRI may help diagnose focal solid liver lesions by evaluating their enhancement patterns. PMID:24950259
Evaluation of a maleimido derivative of CHX-A'' DTPA for site-specific labeling of affibody molecules.
Tolmachev, Vladimir; Xu, Heng; WÕllberg, Helena; Ahlgren, Sara; Hjertman, Magnus; Sj÷berg, Anna; Sandstr÷m, Mattias; Abrahmsķn, Lars; Brechbiel, Martin W; Orlova, Anna
Affibody molecules are a new class of small targeting proteins based on a common three-helix bundle structure. Affibody molecules binding a desired target may be selected using phage-display technology. An Affibody molecule Z HER2:342 binding with subnanomolar affinity to the tumor antigen HER2 has recently been developed for radionuclide imaging in vivo. Introduction of a single cysteine into the cysteine-free Affibody scaffold provides a unique thiol group for site-specific labeling of recombinant Affibody molecules. The recently developed maleimido-CHX-A'' DTPA was site-specifically conjugated at the C-terminal cysteine of Z HER2:2395-C, a variant of Z HER2:342, providing a homogeneous conjugate with a dissociation constant of 56 pM. The yield of labeling with (111)In was >99% after 10 min at room temperature. In vitro cell tests demonstrated specific binding of (111)In-CHX-A'' DTPA-Z 2395-C to HER2-expressing cell-line SKOV-3 and good cellular retention of radioactivity. In normal mice, the conjugate demonstrated rapid clearance from all nonspecific organs except kidney. In mice bearing SKOV-3 xenografts, the tumor uptake of (111)In-CHX-A'' DTPA-Z 2395-C was 17.3 +/- 4.8% IA/g and the tumor-to-blood ratio 86 +/- 46 (4 h postinjection). HER2-expressing xenografts were clearly visualized 1 h postinjection. In conclusion, coupling of maleimido-CHX-A'' DTPA to cysteine-containing Affibody molecules provides a well-defined uniform conjugate, which can be rapidly labeled at room temperature and provides high-contrast imaging of molecular targets in vivo. PMID:18620447
A novel contrast agent with rare earth-doped up-conversion luminescence and Gd-DTPA magnetic resonance properties
Lu Qing [Department of Radiology, Shanghai Renji Hospital, Shanghai Jiao Tong University School of Medicine, 1630 Dong Fang Rd, Shanghai 200127 (China); Wei Daixu [National Engineering Research Center for Nanotechnology, 28 East Jiang Chuan Rd, Shanghai 200241 (China); Cheng Jiejun [Department of Radiology, Shanghai Renji Hospital, Shanghai Jiao Tong University School of Medicine, 1630 Dong Fang Rd, Shanghai 200127 (China); Xu Jianrong, E-mail: email@example.com [Department of Radiology, Shanghai Renji Hospital, Shanghai Jiao Tong University School of Medicine, 1630 Dong Fang Rd, Shanghai 200127 (China); Zhu Jun, E-mail: email@example.com [National Engineering Research Center for Nanotechnology, 28 East Jiang Chuan Rd, Shanghai 200241 (China)
The magnetic-luminescent multifunctional nanoparticles based on Gd-DTPA and NaYF{sub 4}:Yb, Er were successfully synthesized by the conjugation of activated DTPA and silica-coated/surface-aminolated NaYF{sub 4}:Yb, Er nanoparticles through EDC/NHS coupling chemistry. The as-prepared products were characterized by powder X-ray diffraction, transmission electron microscopy, dynamic light scattering, energy dispersive X-ray analysis, and fourier transform infrared spectrometry. The room-temperature upconversion luminescent spectra and T{sub 1}-weighted maps of the obtained nanoparticles were carried out by 980 nm NIR light excitation and a 3T MR imaging scanner, respectively. The results indicated that the as-synthesized multifunctional nanoparticles with small size, highly solubility in water, and both high MR relaxivities and upconversion luminescence may have potential usage for MR imaging in future. - Graphical abstract: We have synthesized magnetic-luminescent multifunctional nanoparticles based on Gd-DTPA and NaYF4:Yb, Er by the conjugation of activated DTPA and silica-coated/surface-aminolated NaYF4:Yb, Er nanoparticles through EDC/NHS coupling chemistry. Highlights: Black-Right-Pointing-Pointer A novel magnetic-luminescent multifunctional nanoparticles are synthesized. Black-Right-Pointing-Pointer The nanoparticles are highly efficient for luminescence and T{sub 1}-weighted MR imaging. Black-Right-Pointing-Pointer The nanoparticles are small in size and highly solubility in water. Black-Right-Pointing-Pointer The nanoparticles hold great potential usage for future biomedical engineering.
The use of 99m Tc-DTPA for detection and localization of site of acute gastrointestinal bleeding
Hussein Abdel-Dayem; Krishan Mahajan; Azu Owuwanne; Sten Ericsson; Khalid Nawaz; Kypros Kouris; Ezzat Higazy; Maha Awdeh
Intravenously injected 99mTc-DTPA was evaluated in 64 patients for its efficiency in detecting and localizing sites of acute upper and lower gastrointestinal (G.I.) bleeding. These studies were correlated with endoscopic and surgical findings. There were 34 bleeders and 30 non bleeders giving a sensitivity of 90%, specificity of 82% and accuracy of 86%. Of these, 49 were upper G.I. studies
A general mathematical model describing the motion of particles in aerosol centrifuges has been developed. t has been validated by comparisons of theoretically predicted calibration sites with experimental data from tests sizing aerosols in instruments of three different spiral d...
The determination of relative renal function in a pediatric population using Tc-99m DTPA and Tc-99m DMSA
Rosen, P.R.; Kuruc, A.; Treves, S.T.
Three methods for evaluating relative renal function in a pediatric population were compared. The clinical and nuclear medicine data of 73 patients were reviewed. Pertinent data included patient age, serum creatinine and the referral diagnosis (reflux, hypertension, obstructive uropathy). Time activity curves for renal regions of interest (ROI) were obtained by renography with Tc-99m DTPA, and deconvolved by an externally detected blood pool curve Furosemide was then administered to evaluate the renal collecting system (if indicated). This was followed by DMSA administration. Relative function was determined in 3 ways: 1) Accumulated renal DTPA activity 60-120 sec. following injection. 2) Amplitude of the tubular phase of the deconvolved renal curve and, 3) Accumulated Tc-99m DMSA activity in renal ROI 4 or 24 hrs. post-injection. Regression analysis revealed: 1) The basic relationship of relative functional data obtained by all three methods was not affected by creatinine, age or other factors. 2) The relationship between the three methods is linear and highly correlated. 3) The DMSA values may be predicted from either method of analyzing the DTPA study using appropriate predictor equations. The authors conclude that Tc-99m DMSA, due to its higher cost and more radiation exposure should not be used for the routine evaluation of relative renal function.
One form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. To study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter clo...
PET imaging of tumor angiogenesis in mice with VEGF-A-targeted (86)Y-CHX-A?-DTPA-bevacizumab.
Nayak, Tapan K; Garmestani, Kayhan; Baidoo, Kwamena E; Milenic, Diane E; Brechbiel, Martin W
Bevacizumab is a humanized monoclonal antibody that binds to tumor-secreted vascular endothelial growth factor (VEGF)-A and inhibits tumor angiogenesis. In 2004, the antibody was approved by the US Food and Drug Administration (FDA) for the treatment of metastatic colorectal carcinoma in combination with chemotherapy. This report describes the preclinical evaluation of a radioimmunoconjugate, (86)Y-CHX-A?-DTPA-bevacizumab, for potential use in Positron Emission Tomography (PET) imaging of VEGF-A tumor angiogenesis and as a surrogate marker for (90)Y-based radioimmunotherapy. Bevacizumab was conjugated to CHX-A?-DTPA and radiolabeled with (86)Y. In vivo biodistribution and PET imaging studies were performed on mice bearing VEGF-A-secreting human colorectal (LS-174T), human ovarian (SKOV-3) and VEGF-A-negative human mesothelioma (MSTO-211H) xenografts. Biodistribution and PET imaging studies demonstrated highly specific tumor uptake of the radioimmunoconjugate. In mice bearing VEGF-A-secreting LS-174T, SKOV-3 and VEGF-A-negative MSTO-211H tumors, the tumor uptake at 3 days postinjection was 13.6 ▒ 1.5, 17.4 ▒ 1.7 and 6.8 ▒ 0.7 % ID/g, respectively. The corresponding tumor uptake in mice coinjected with 0.05 mg cold bevacizumab were 5.8 ▒ 1.3, 8.9 ▒ 1.9 and 7.4 ▒ 1.0 % ID/g, respectively at the same time point, demonstrating specific blockage of the target in VEGF-A-secreting tumors. The LS-174T and SKOV3 tumors were clearly visualized by PET imaging after injecting 1.8-2.0 MBq (86)Y-CHX-A?-DTPA-bevacizumab. Organ uptake quantified by PET closely correlated (r(2) = 0.87, p = 0.64, n = 18) to values determined by biodistribution studies. This preclinical study demonstrates the potential of the radioimmunoconjugate, (86)Y-CHX-A?-DTPA-bevacizumab, for noninvasive assessment of the VEGF-A tumor angiogenesis status and as a surrogate marker for (90)Y-CHX-A?-DTPA-bevacizumab radioimmunotherapy. PMID:20473899
PET imaging of tumor angiogenesis in mice with VEGF-A targeted 86Y-CHX-A?-DTPA-bevacizumab
Nayak, Tapan K.; Garmestani, Kayhan; Baidoo, Kwamena E.; Milenic, Diane E.; Brechbiel, Martin W.
Bevacizumab is a humanized monoclonal antibody that binds to tumor-secreted VEGF-A and inhibits tumor angiogenesis. In 2004, the antibody was approved by the United States FDA for the treatment of metastatic colorectal carcinoma in combination with chemotherapy. This report describes the preclinical evaluation of a radioimmunoconjugate, 86Y-CHX-A?-DTPA-bevacizumab, for potential use in PET imaging of VEGF-A tumor angiogenesis and as a surrogate marker for 90Y based radioimmunotherapy. Bevacizumab was conjugated to CHX-A?-DTPA and radiolabeled with 86Y. In vivo biodistribution and PET imaging studies were performed on mice bearing VEGF-A secreting human colorectal (LS-174T), human ovarian (SKOV-3) and VEGF-A negative human mesothelioma (MSTO-211H) xenografts. Biodistribution and PET imaging studies demonstrated high specific tumor uptake of the radioimmunoconjugate. In mice bearing VEGF-A secreting LS-174T, SKOV-3 and VEGF-A negative MSTO-211H tumors, the tumor uptake at 3 d post-injection (p.i) was 13.6 ▒ 1.5, 17.4 ▒ 1.7 and 6.8 ▒ 0.7 % ID/g, respectively. The corresponding tumor uptake in mice co-injected with 0.05 mg cold bevacizumab were 5.8 ▒ 1.3, 8.9 ▒ 1.9 and 7.4 ▒ 1.0 % ID/g, respectively at the same time point, demonstrating specific blockage of the target in VEGF-A secreting tumors. The LS-174T and SKOV3 tumors were clearly visualized by PET imaging after injecting 1.8¢2.0 MBq 86Y-CHX-A?-DTPA-bevacizumab. Organ uptake quantified by PET closely correlated (r2=0.87, p=0.64, n=18) to values determined by biodistribution studies. This preclinical study demonstrates the potential of the radioimmunoconjugate, 86Y-CHX-A?-DTPA-bevacizumab, for non-invasive assessment of the VEGF-A tumor angiogenesis status and as a surrogate marker for 90Y-CHX-A?-DTPA-bevacizumab radioimmunotherapy. PMID:20473899
NASA Technical Reports Server (NTRS)
2003-01-01Strong synoptic winds usually help to disperse pollutants over the skies of Greece and the Aegean Sea during winter months, and in late summer relatively strong northerly winds typically prevent significant aerosol influx from the south. During the summer of 2002, the northerly Etesian winds were exceptionally weak, allowing Sahara dust from the south to reach the Aegean region. This resulted in elevated aerosol levels, particularly in the month of July. The abundance of aerosol over Greece and the Aegean Sea on four dates during the summer of 2002 are illustrated by these images from the Multi-angle Imaging SpectroRadiometer (MISR).In the natural-color images (the left-hand panel of each pair), it is apparent that aerosol particles are more abundant over the region on the two dates in July than in either June or August. These natural-color views were acquired by MISR's 70-degree forward-viewing camera. The top and bottom views depict overlapping parts of mainland Greece and the Aegean, with the bottom panels covering a region to the west of the top panels. Data from each of the four dates have been processed identically, and relative brightness variations between the views are preserved.MISR retrieves information on aerosol amount and particle properties by using the changes in scene brightness and contrast at nine widely-spaced view angles and four spectral bands. The right-hand panel of each image pair is a map of retrieved aerosol amount, parameterized by a quantity called aerosol optical depth. A color scale is used to represent this quantity. Higher amounts of aerosol within the total column of the atmosphere are indicated by green, yellow or orange pixels, and clearer skies are indicated by purple and blue pixels. Dark gray pixels indicate places where clouds or other factors precluded an aerosol retrieval.The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during Terra orbits 13325, 13558, 13660 and 14126. The panels utilize data from blocks 59 to 62 within World Reference System-2 paths 182 and 183.MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.
NASA Technical Reports Server (NTRS)
Clarke, Antony D.; Rothermel, Jeffry; Jarzembski, Maurice A.
This task addresses the measurement and understanding of the physical and chemical properties of aerosol in remote regions that are responsible for aerosol backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent aerosol properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these aerosols in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the aerosol microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE).
simplified aerosol representations in global modeling
NASA Astrophysics Data System (ADS)
Kinne, Stefan; Peters, Karsten; Stevens, Bjorn; Rast, Sebastian; Schutgens, Nick; Stier, Philip
The detailed treatment of aerosol in global modeling is complex and time-consuming. Thus simplified approaches are investigated, which prescribe 4D (space and time) distributions of aerosol optical properties and of aerosol microphysical properties. Aerosol optical properties are required to assess aerosol direct radiative effects and aerosol microphysical properties (in terms of their ability as aerosol nuclei to modify cloud droplet concentrations) are needed to address the indirect aerosol impact on cloud properties. Following the simplifying concept of the monthly gridded (1x1 lat/lon) aerosol climatology (MAC), new approaches are presented and evaluated against more detailed methods, including comparisons to detailed simulations with complex aerosol component modules.
Comparison of MRI properties between derivatized DTPA and DOTA gadolinium-dendrimer conjugates
Nwe, K.; Bernardo, M; Regino, C. A. S.; Williams, M; Brechbiel, M. W.
In this report we directly compare the in vivo and in vitro MRI properties of gadolinium-dendrimer conjugates of derivatized acyclic diethylenetriamine-N,NÆ,NÆ,NÆÆ, NÆÆ-pentaacetic acid (1B4M-DTPA) and macrocyclic 1,4,7,10-tetraazacyclododecane-N,NÆ,NÆÆ,NÆÆÆ-tetraacetic acid (C-DOTA). The metal-ligand chelates were pre-formed in alcohol prior to conjugation to the generation 4 PAMAM dendrimer (G4D), and the dendrimer-based agents were purified by Sephadex« G-25 column. The analysis and SE-HPLC data indicated chelate to dendrimer ratios of 30:1 and 28:1 respectively. Molar relaxivity measured at pH 7.4, 22░C, and 3T are comparable (29.5 vs. 26.9 mM?1s?1), and both conjugates are equally viable as MRI contrast agents based on the images obtained. The macrocyclic agent however exhibits a faster rate of clearance in vivo (t1/2 = 16 vs. 29 min.). Our conclusion is that the macrocyclic-based agent is the more suitable agent for in vivo use for these reasons combined with kinetic inertness associated with the Gd(III) DOTA complex stability properties. PMID:20663676
Tumor-targeted HPMA copolymer-(RGDfK)-(CHX-A''-DTPA) conjugates show increased kidney accumulation.
Borgman, Mark P; Coleman, Tomika; Kolhatkar, Rohit B; Geyser-Stoops, Sandra; Line, Bruce R; Ghandehari, Hamidreza
N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-RGDfK conjugates targeting the alpha(v)beta(3) integrin have shown increased accumulation in solid tumors and promise for selective delivery of radiotherapeutics to sites of angiogenesis- or tumor-expressed alpha(v)beta(3) integrin. An unresolved issue in targeting radiotherapeutics to solid tumors is toxicity to non-target organs. To reduce toxicity of radiolabeled conjugates, we have synthesized HPMA copolymer-RGDfK conjugates with varying molecular weight and charge content to help identify a polymeric structure that maximizes tumor accumulation while rapidly clearing from non-targeted organs. Endothelial cell binding studies showed that copolymer conjugates of approximately 43, 20 and 10 kD actively bind to the alpha(v)beta(3) integrin. Scintigraphic images showed rapid clearance of indium-111 ((111)In) radiolabeled conjugates from the blood pool and high kidney accumulation within 1 h in tumor bearing mice. Biodistribution data confirms images with high accumulation in kidney (max 210% ID/g for 43 kD conjugate) and lower tumor accumulation (max 1.8% ID/g for 43 kD conjugate). While actively binding to the alpha(v)beta(3) integrin in vitro, HPMA copolymer-RGDfK conjugates with increased negative charge through increased CHX-A''-DTPA chelator content in the side chains causes increased kidney accumulation with a loss of tumor accumulation in vivo. PMID:18687371
Case Study: Three Acute 241Am Inhalation Exposures with DTPA Therapy
Carbaugh, Eugene H.; Lynch, Timothy P.; Cannon, Curt; Lewis, Loren L.
Three workers incurred inhalation exposures to 241Am oxide as a result of waste sorting and compaction activities. The magnitudes of the exposures were not fully recognized until the following day when an in vivo chest count identified a significant lung deposition of 241Am in a male worker, and DTPA chelation therapy was initiated. Two additional workers (one female and one male) were then identified as sufficiently exposed to also warrant therapy. In vivo bioassay measurements were performed over the ensuing 6 months to quantify the 241Am activity in the lungs, liver, and skeleton. Urine and fecal samples were collected and showed readily detectable 241Am. Clinical lab tests and medical evaluations all showed normal results. There were no significant adverse clinical health effects from the therapy. The estimated 241Am inhalation intakes for the three workers were 1800 Bq, 630 Bq, and 150 Bq. Lung retention showed somewhat longer pulmonary clearance half-times than standard inhalation class W or absorption Type M assumptions. The three underwent slightly different therapy regimes, with therapy effectiveness factors (defined as the ratio of the reference doses without therapy relative to the final assessed doses) of 4.65, 1.93, and 1.67, respectively.
Aerosol reactor for silicon processing
NASA Technical Reports Server (NTRS)
Flagan, R. C.; Alam, M. K.; Johnson, B. E.; Wu, J. J.
Silane pyrolysis, homogeneous nucleation; and an aerosol reactor for the growth of large silicon particles by silane pyrolysis are discussed. Graphs show data on temperature profile and reaction kinetics in the aerosol reactor, as well as particle growth, total clearance volume fraction, mass distribution of silicon aerosol in high temperatures, and silicon losses as a function of input silane concentration.
Ionisers and electrical aerosol removal
R. G. Harrison
Ionisers are widely supposed to bring health benefits, although the evidence is principally only anecdotal. One physical process, however, which can be directly investigated, is the enhanced aerosol removal associated with using ionisers. The large excess of negative ions produced by ionisers must lead to unipolar negative aerosol charging, which can influence the aerosol removal rates. (It may of course
Lidar measurements during Aerosols99
Kenneth J. Voss; Ellsworth J. Welton; Patricia K. Quinn; James Johnson; Anne M. Thompson; Howard R. Gordon
The Aerosols99 cruise (January 14 to February 8, 1999) went between Norfolk, Virginia, and Cape Town, South Africa. A Micropulse lidar system was used almost continually during this cruise to profile the aerosol vertical structure. Inversions of this data illustrated a varying vertical structure depending on the dominant air mass. In clean maritime aerosols in the Northern and Southern Hemispheres
Carbon aerosols and atmospheric photochemistry
D. J. Lary; A. M. Lee; R. Toumi; M. J. Newchurch; M. Pirre; J. B. Renard
Carbon aerosols are produced by all combustion processes. This paper investigates some possible effects of heterogeneous reduction of atmospheric constituents on carbon aerosols. Reduction of HNO3, NO2, and 03 on carbon aerosols may be an important effect of increased air traffic that has not been considered to date. It is shown that if HNO3, NO2 and 03 are heterogeneously reduced
Aerosol Quality Monitor (AQUAM)
NASA Astrophysics Data System (ADS)
Liang, X.; Ignatov, A.
The Advanced Clear-Sky Processor for Oceans (ACSPO) developed at NESDIS generates three products from AVHRR, operationally: clear sky radiances in all bands, and sea surface temperature (SST) derived from clear-sky brightness temperatures (BT) in Ch3B (centered at 3.7 ?m), Ch4 (11 ?m) and Ch5 (12 ?m), and aerosol optical depths (AOD) derived from clear-sky reflectances in Ch1 (0.63), Ch2 (0.83) and Ch3A (1.61 ?m). An integral part of ACSPO is the fast Community Radiative Transfer Model (CRTM), which calculates first-guess clear-sky BTs using global NCEP forecast atmospheric and Reynolds SST fields. Simulated BTs are employed in ACSPO for improved cloud screening, physical (RTM-based) SST inversions, and to monitor and validate satellite BTs. The model minus observation biases are monitored online in near-real time using the Monitoring IR Clear-sky radiances over Oceans for SST (MICROS; http://www.star.nesdis.noaa.gov/sod/sst/micros/). A persistent positive M-O bias is observed in MICROS, partly attributed to missing aerosol in CRTM input, causing "M" to be warmer than "O". It is thus necessary to include aerosols in CRTM and quantify their effects on AVHRR BTs and SSTs. However, sensitivity of thermal bands to aerosol is only minimal, and use of solar reflectance bands is preferable to evaluate the accuracy of CRTM modeling, with global aerosol fields as input (from e.g. Goddard Chemistry Aerosol Radiation and Transport, GOCART, or Navy Aerosol Analysis and Prediction System, NAAPS). Once available, the corresponding M-O biases in solar reflectance bands will be added to MICROS. Also, adding CRTM simulated reflectances in ACSPO would greatly improve cloud detection, help validate CRTM in the solar reflectance bands, and assist aerosol retrievals. Running CRTM with global aerosol as input is very challenging, computationally. While CRTM is being optimized to handle such global scattering computations, a near-real time web-based Aerosol Quality Monitor (AQUAM; http://www.star.nesdis.noaa.gov/sod/sst/aquam/) was set up, to check AVHRR (and later, VIIRS) AOD retrievals for self-consistency, and check them for cross-consistency with MOD04_L2 and MYD04_L2 from well-calibrated MODIS sensor. Also, adding in-situ AOD data from the Aerosol Robotic Network (AERONET) is currently under way. Finally, GOCART and NAAPS data will be added to AQUAM, and satellite, AERONET, and model AODs will all be checked for cross-consistency. Next step will be comparison of CRTM simulations (with GOCART or NAAPS input) with top-of-atmosphere sensor reflectances. Once consistency in solar reflectance bands is achieved, we will check the effect of aerosols on the thermal bands and correct its effect on SST.
Highly stable aerosol generator
DeFord, H.S.; Clark, M.L.
An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.
Highly stable aerosol generator
DeFord, Henry S. (Kennewick, WA); Clark, Mark L. (Kennewick, WA)
An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.
Utilization of synergetic aerosol retrieval
NASA Astrophysics Data System (ADS)
Holzer-Popp, Thomas
A synergetic aerosol retrieval method SYNAER which exploits a combination of a radiome-ter and a spectrometer onboard ENVISAT and METOP has been developed. This method enables retrieval of aerosol optical depth and an estimation of the aerosol composition. Due to the sampling characteristics and available information content of the combined sensor data the utilization of the results has to be done with appropriate care. On the other hand the specifically new information on aerosol composition enables new applications in the fields of aerosol monitoring (differntiating components), air quality (fine particulate matter assessment and data assimilation), and climate research (aerosol-cloud interaction analysis for different aerosol components). The paper will show examples of applications in the various fields. The paper will be based on ongoing reprocessing of SYNAER for ENVISAT 2003-2009 within ESA GSE PROMOTE and on experimental selected results for METOP. Implications of the different sampling of the two sensor combinations for the differnt applications will be assessed.
Comparative effects of the chelators sodium 4,5-dihydroxybenzene-1,3-disulfonate (Tiron) and diethylenetriaminepentaacetic acid (DTPA) on acute uranium nephrotoxicity in rats.
Domingo, J L; de la Torre, A; Bellķs, M; Mayayo, E; Llobet, J M; Corbella, J
Sodium 4,5-dihydroxybenzene-1,3-disulfonate (Tiron) and diethylenetriaminepentaacetic acid (DTPA) are two chelating agents that have been demonstrated to be effective in the treatment of experimental poisoning by a number of heavy metals. In this study, the effects of Tiron and DTPA on uranium-induced nephrotoxicity were evaluated in a rat model. A series of four Tiron or DTPA injections was administered intraperitoneally to adult male Sprague-Dawley rats immediately after a single subcutaneous injection of uranyl acetate dihydrate (5 mg/kg) and at 24, 48 and 72 h thereafter. Positive and negative control groups received 0.9% saline with or without uranyl acetate, respectively. Tiron effectiveness was assessed at 400, 800 and 1600 mg/kg, whereas DTPA was administered at 250, 500 and 1000 mg/kg. Although the urinary excretion of uranium was significantly enhanced by Tiron administration, significant amounts of uranium still remained in the kidney at the end of the treatment. However, the partial reduction of the renal uranium concentrations was in accordance with the amelioration noted in some urinary and serum indicators of uranium nephrotoxicity. Moreover, Tiron administration also reduced the severity of the uranium-induced histological alterations in the kidney. According to these results, Tiron offers only a modest encouragement with regard to its possible therapeutic potential to treat acute uranium-induced nephrotoxic effects. In turn, DTPA was less effective than Tiron in protecting against the nephrotoxicity of uranium in rats. PMID:9074653
Aerosol contributions to speleothem geochemistry
NASA Astrophysics Data System (ADS)
Dredge, J. A.; Fairchild, I. J.; Harrison, R.; Woodhead, J. D.; Hellstrom, J.
The term "aerosols" encompasses the suspension of both fine solid or liquid particles within a gaseous medium. Aerosols become suspended into the earth's atmosphere through a multitude of processes both natural and anthropogenic. Atmospheric aerosols enter cave networks as a result of cave ventilation processes and are either deposited, or cycled and removed from the system. Speleothem offer a multiproxy palaeoclimate resource; many of the available proxies have been extensively investigated and utilised for palaeoclimatic reconstructions in a range of studies. The potential contribution of aerosols to speleothem chemistry and their applicability for palaeoenvironmental reconstructions remains untested and the extent of their value as an addition to palaeoclimate sciences unknown. Aerosols through incorporation into speleothem may provide a novel palaeoenvironmental resource. The aerosol component of interest is that which is transported into the cave atmosphere and deposited and are available for incorporation into precipitated calcite. Aerosol deposition and therefore distribution in the cave has shown to be a complex function of ventilation and changing environmental factors. Through detailed monitoring aerosols have been detected, identified, characterised and quantified to determine their prominence in the cave system. Investigations are on a case study basis, searching for suitable aerosol proxies of environmentally significant emission processes. Case studies include: Palaeofires at Yarrangobilly Caves, Australia; anthropogenic emissions at St Michaels Cave, Gibraltar and Cheddar gorge, UK; and drip water aerosol production and geochemical addition in Obir cave, Austria. Monitoring has allowed for the temporal and spatial determination of aerosols in karst networks. Speleothem samples will be analysed in combination with in-situ monitoring to determine incorporation factors and record preservation. By understanding how aerosols are transmitted within the cave and ultimately incorporated into speleothems, a record of aerosol emission event frequency, intensity and timing can be produced and directly correlated with changing palaeoclimate. Speleothem through aerosol incorporation have the potential to preserve a record of a multitude of processes not yet constrained by previously investigated proxies, providing an additional dimension to speleological palaeoenvironmental investigations.
Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...
Exploring Further Relationships: Aerosols
NSDL National Science Digital Library
Student teams explore atmospheric aerosols, dust, and fires and their impact on the Earth's albedo using NASA Earth Observations (NEO) website. This is an extension activity in the student learning activity guide accompanying the GLOBE Earth System Poster, Exploring Connections in Year 2007. A series of six learning activities and associated assessment activities are included.
This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...
The objective was to develop a better understanding of smog aerosol formation with particular reference to haze in the Southern California area. This study combined laboratory work with ambient air studies. Counting of particles by light scattering was the principle physical tech...
Thermophoresis of Aerosol Spheroids
Huan J. Keh; Chang L. Ou
An analytical study is presented for the thermophoretic motion of a freely suspended aerosol spheroid in a uniform prescribed temperature gradient that is oriented arbitrarily with respect to its axis of revolution. The Knudsen number is assumed to be small so that the fluid flow is described by a continuum model with a thermal slip at the particle surface. In
Advanced Aerosol Lidar Ratio Determination Algorithms Using Aerosol Covariance Models
NASA Astrophysics Data System (ADS)
Hostetler, C. A.; Omar, A. H.; Burton, S. P.; Vaughan, M.; Rogers, R.; Ferrare, R. A.; Reagan, J. A.; McPherson, C.
We present an algorithm to determine the extinction to backscatter (lidar) ratio (Sa), an important parameter used in the determination of the aerosol extinction and subsequently the optical depth from lidar backscatter measurements. This scheme applies to Sa determination at 532 nm and 1064 nm for a space-based two-wavelength lidar such as CALIOP on the Cloud and Aerosol Lidar and Infrared Pathfinder Spaceborne Observations (CALIPSO) satellite. The algorithm applies the Mahalanobis distance to CALIOP measurements of backscatter and depolarization and initial estimates of Sa at both wavelengths to identify the most likely aerosol model from a family of a priori probability distributions of lidar ratio, backscatter and depolarization determined from previously generated classification of High Spectral Resolution Lidar (HSRL) aerosol measurements. The HSRL record includes aerosol type specific distributions of Sa at 532 nm. We use auxiliary measurements of pairs of 532 nm and 1064 nm Sa for Urban, Smoke, Marine, and Dust aerosols from AERONET and field measurements, the NASA African Monsoon Multidisciplinary Analyses (NAMMA) and Shoreline Environmental Aerosol Study (SEAS), to develop piecewise covariance matrices using the HSRL distributions of these four aerosol types. Covariance matrices including lidar ratio at both wavelengths can also be obtained through the Enhanced Constrained Ratio Aerosol Method (E-CRAM) applied to HSRL data. We explore the application of the aerosol model matching method to CALIOP data and compare the results with HSRL 532 nm Sa distributions for coincident flights.
American Association for Aerosol Research (AAAR) `95
The Fourteenth annual meeting of the American Association for Aerosol Research was held October 9-13, 1995 at Westin William Penn Hotel in Pittsburgh, PA. This volume contains the abstracts of the papers and poster sessions presented at this meeting, grouped by the session in which they were presented as follows: Radiation Effects; Aerosol Deposition; Collision Simulations and Microphysical Behavior; Filtration Theory and Measurements; Materials Synthesis; Radioactive and Nuclear Aerosols; Aerosol Formation, Thermodynamic Properties, and Behavior; Particle Contamination Issues in the Computer Industry; Pharmaceutical Aerosol Technology; Modeling Global/Regional Aerosols; Visibility; Respiratory Deposition; Biomass and Biogenic Aerosols; Aerosol Dynamics; Atmospheric Aerosols.
Fully automatic region of interest selection in glomerular filtration rate estimation from 99mTc-DTPA renogram.
Lin, Kun-Ju; Huang, Jia-Yann; Chen, Yung-Sheng
Glomerular filtration rate (GFR) is a common accepted standard estimation of renal function. Gamma camera-based methods for estimating renal uptake of (99m)Tc-diethylenetriaminepentaacetic acid (DTPA) without blood or urine sampling have been widely used. Of these, the method introduced by Gates has been the most common method. Currently, most of gamma cameras are equipped with a commercial program for GFR determination, a semi-quantitative analysis by manually drawing region of interest (ROI) over each kidney. Then, the GFR value can be computed from the scintigraphic determination of (99m)Tc-DTPA uptake within the kidney automatically. Delineating the kidney area is difficult when applying a fixed threshold value. Moreover, hand-drawn ROIs are tedious, time consuming, and dependent highly on operator skill. Thus, we developed a fully automatic renal ROI estimation system based on the temporal changes in intensity counts, intensity-pair distribution image contrast enhancement method, adaptive thresholding, and morphological operations that can locate the kidney area and obtain the GFR value from a (99m)Tc-DTPA renogram. To evaluate the performance of the proposed approach, 30 clinical dynamic renograms were introduced. The fully automatic approach failed in one patient with very poor renal function. Four patients had a unilateral kidney, and the others had bilateral kidneys. The automatic contours from the remaining 54 kidneys were compared with the contours of manual drawing. The 54 kidneys were included for area error and boundary error analyses. There was high correlation between two physicians' manual contours and the contours obtained by our approach. For area error analysis, the mean true positive area overlap is 91%, the mean false negative is 13.4%, and the mean false positive is 9.3%. The boundary error is 1.6 pixels. The GFR calculated using this automatic computer-aided approach is reproducible and may be applied to help nuclear medicine physicians in clinical practice. PMID:21274591
Comparison of oral iodine-131-cellulose and indium-111-DTPA as tracers for colon transit scintigraphy: Analysis by colon activity profiles
Smart, R.C.; McLean, R.G.; Gaston-Parry, D.; Barbagallo, S.; Bruck, C.E.; King, D.W.; Lubowski, D.Z.; Talley, N.A. (Department of Nuclear Medicine, St. George Hospital, Sydney, NSW (Australia))
In 11 normal subjects and 11 patients with a clinical diagnosis of constipation, oral 131I-cellulose and 111In-DTPA were compared simultaneously as tracers for radionuclide colon transit scintigraphy. Visual assessment of the images revealed no differences between tracers. Quantitation was performed using total and segmental percent retention and the derived value of clearance half-time. In addition, profiles of the activity distribution along the length of the colon were generated and the mean position of the activity in the colon calculated. For all indices, the results were similar in both normal subjects and constipated patients when comparing tracers, although marked differences were present between normal subjects and constipated patients for each tracer. Indium-111-DTPA was easy to administer and dosimetry was more acceptable than for 131I-cellulose, especially in constipated patients. It is concluded that 111In-DTPA is the preferred tracer for oral colon transit scintigraphy.
Volcanic aerosols and lunar eclipses.
Keen, R A
The moon is visible during total lunar eclipses due to sunlight refracted into the earth's shadow by the atmosphere. Stratospheric aerosols can profoundly affect the brightness of the eclipsed moon. Observed brightnesses of 21 lunar eclipses during 1960-1982 are compared with theoretical calculations based on refraction by an aerosol-free atmosphere to yield globally averaged aerosol optical depths. Results indicate the global aerosol loading from the 1982 eruption of El Chich¾n is similar in magnitude to that from the 1963 Agung eruption. PMID:17776243
LIDAR Measurements During Aerosols99
NASA Technical Reports Server (NTRS)
Voss, Kenneth J.; Welton, Ellsworth J.; Quinn, Patricia K.; Johnson, James; Thompson, Anne; Einaudi, Franco (Technical Monitor)
The Aerosols99 cruise took place during the period from January 14, to February 8 1999 on the R/V Ron Brown. The cruise track was almost a straight line from Norfolk, Va. to Cape Town, South Africa and afforded the opportunity to sample several different aerosol regimes over the North and South Atlantic. A Micro Pulse LIDAR system was used continually during this cruise to profile the aerosol vertical structure. Inversions of this data illustrated a varying vertical structure depending on the dominant air mass. In clean maritime aerosols in the Northern and Southern Hemispheres the aerosols were capped at 1 km. When a Dust event from Africa was encountered the aerosol extinction increased its maximum height to above 2 km. During a period in which the air mass was dominated by biomass burning from Southern Africa, the aerosol layer extended to 4 km. Comparisons of the aerosol optical depth derived from LIDAR inversion and surface sunphotometers showed an agreement within +/- 0.05 RMS Similar comparisons between the extinction measured with a nephelometer and particle soot absorption photometer (at 19 m altitude) and the lowest LIDAR measurement (75 m) showed good agreement (+/- 0.014/km . The LIDAR underestimated surface extinction during periods when an elevated aerosol layer was present over a relatively clean surface layer, but otherwise gave accurate results.
NASA Astrophysics Data System (ADS)
DeSha, Michael S.
In recent history, manmade and natural events have shown us the every-present need for systems to monitor the troposphere for contaminates. These contaminants may take either a chemical or biological form, which determines the methods we use to monitor them. Monitoring the troposphere for biological contaminants is of particular interest to my organization. Whether manmade or natural, contaminants of a biological origin share similar constituents; typically the aromatic amino acids tryptophan, phenylalanine, and tyrosine. All of these proteinaceous compounds autofluorescence when exposed to UV radiation and this established the basis of the laser-induced fluorescence technique we use to detect biological contaminants. This technique can be employed in either point or remote detection schemes and is a valuable tool for discriminating proteinaceous form non-proteinaceous aerosols. For this particular presentation I am going to describe a breadboard point sensor we designed and fabricated to detect proteinaceous aerosols. Previous point sensor designs relied on convoluted flow paths to concentrate the aerosols into a solution. Other systems required precise beam alignment to evenly distribute the energy irradiating the detector elements. Our objective was to build a simple system where beam alignment is not critical, and the flow is straight and laminar. The breadboard system was developed over a nine- month period and its performance assessed at a recent test at Dugway Proving Grounds in Utah. In addition, we have performed chamber experiments in an attempt to establish a baseline for the systems. The results of these efforts are presented here.
Photothermal spectroscopy of aerosols
Campillo, A.J.; Lin, H.B.
In situ aerosol absorption spectroscopy was performed using two novel photothermal detection schemes. The first, based on a photorefractive effect and coherent detection, called phase fluctuation optical heterodyne (PFLOH) spectroscopy, could, depending on the geometry employed, yield particle specific or particle and gas absorption data. Single particles of graphite as small as 1 ..mu..m were detected in the particle specific mode. In another geometrical configuration, the total absorption (both gas and particle) of submicron sized aerosols of ammonium sulfate particles in equilibrium with gaseous ammonia and water vapor were measured at varying CO/sub 2/ laser frequencies. The specific absorption coefficient for the sulfate ion was measured to be 0.5 m/sup 2//g at 1087 cm/sup -1/. The absorption coefficient sensitivity of this scheme was less than or equal to 10/sup -8/ cm/sup -1/. The second scheme is a hybrid visible Mie scattering scheme incorporating photothermal modulation. Particle specific data on ammonium sulfate droplets were obtained. For chemically identical species, the relative absorption spectrum versus laser frequency can be obtained for polydisperse aerosol distributions directly from the data without the need for complex inverse scattering calculations.
Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer
Jose L. Jimenez; John T. Jayne; Quan Shi; Charles E. Kolb; Douglas R. Worsnop; Ivan Yourshaw; John H. Seinfeld; Richard C. Flagan; Xuefeng Zhang; Kenneth A. Smith; James W. Morris; Paul Davidovits
The Aerodyne Aerosol Mass Spectrometer (AMS) has been designed to measure size-resolved mass distributions and total mass loadings of volatile and semivolatile chemical species in\\/on submicron particles. This paper describes the application of this instrument to ambient aerosol sampling. The AMS uses an aerodynamic lens to focus the particles into a narrow beam, a roughened cartridge heater to vaporize them
Studies of organic aerosol and aerosol-cloud interactions
NASA Astrophysics Data System (ADS)
Duong, Hanh To
Atmospheric aerosols can influence society and the environment in many ways including altering the planet's energy budget, the hydrologic cycle, and public health. However, the Fourth Assessment Report of the Intergovernmental Panel on Climate Change indicates that the anthropogenic radiative forcing associated with aerosol effects on clouds has the highest uncertainty in the future climate predictions. This thesis focuses on the nature of the organic fraction of ambient particles and how particles interact with clouds using a combination of tools including aircraft and ground measurements, models, and satellite data. Fine aerosol particles typically contain between 20 - 90% organic matter by mass and a major component of this fraction includes water soluble organic carbon (WSOC). Consequently, water-soluble organic species can strongly influence aerosol water-uptake and optical properties. However, the chemical composition of this fraction is not well-understood. PILS-TOC was used to characterize WSOC in ambient aerosol in Los Angeles, California. The spatial distribution of WSOC was found to be influenced by (i) a wide range of aerosol sources within this urban metropolitan area, (ii) transport of pollutants by the characteristic daytime sea breeze trajectory, (iii) topography, and (iv) secondary production during transport. Meteorology is linked with the strength of many of these various processes. Many methods and instruments have been used to study aerosol-cloud interactions. Each observational platform is characterized by different temporal/spatial resolutions and operational principles, and thus there are disagreements between different studies for the magnitude of mathematical constructs used to represent the strength of aerosol-cloud interactions. This work points to the sensitivity of the magnitude of aerosol-cloud interactions to cloud lifetime and spatial resolution of measurements and model simulations. Failure to account for above-cloud aerosol layers and wet scavenging are also shown to cause biases in the magnitude of aerosol-cloud interaction metrics. Air mass source origin and meteorology are also shown to be important factors that influence aerosol-cloud interactions. The results from this work contribute towards a better understanding of atmospheric aerosols and are meant to improve parameterizations that can be embedded in models that treat aerosol affects on clouds, precipitation, air quality, and public health.
Effect of grinding variables on the NH4HCO3 ¢dtpa soil test values for Fe, Zn, Mn, Cu, P, and K
P. N. Soltanpour; A. Khan; A. P. Schwab
The effect of grinding force, time, and weight of soil on the NH4HCO3 ?DTPA extractable levels of Fe, Zn, Mn, Cu, P and K from 10 Colorado soils were studied. It was found that the amount of extractable iron and zinc increased, with an increase in force or time of grinding. The significant interaction between time and force of grinding
In vivo stability and excretion of gadodiamide (GdDTPA-BMA), a hydrophilic gadolinium complex used as a contrast enhancing agent for magnetic resonance imaging.
Normann, P T; Hals, P A
The stability and excretion of [14C]-gadodiamide (GdDTPA-BMA) was studied in male rats after i.v. injection of 0.3 mmol/kg [14C]-GdDTPA-BMA (Gd-diethylenetriaminepentaacetic-acid-bis-methylamide) formulated as gadodiamide injection (OMNISCAN, Nycomed Imaging AS, Oslo, Norway). Samples of blood and urine obtained within 60 min and 6 h postdosing, respectively, were analyzed for radiolabeled compounds. Analysis of GdDTPA-BMA in high and low molecular weight fractions of serum indicated no protein binding. HPLC analyses of urine samples obtained 0-2 h, 2-4 h and 4-6 h after injection revealed no detectable amounts of biotransformation products of GdDTPA-BMA. Serum samples obtained 30 min and 60 min after injection contained 9-13 microM of an unidentified compound which had a retention time different from all conceivable metabolites of gadodiamide. A similar concentration of this unknown compound was found in spiked predose serum samples. The total amount of the unknown compound in serum was less than 1% of the injected dose of [14C]-gadodiamide injection. It is concluded that gadodiamide, when administered i.v. as gadodiamide injection at a dosage of 0.3 mmol/kg, is stable in vivo and that the very major part of the dose (> 99%) is excreted in urine as an unchanged complex. PMID:8983938
Pulsed optoacoustic effect in aerosols
V P Zharov; A E Negin; Ya O Simanovski?
An experimental investigation was made of the optoacoustic effect in water aerosols interacting with CO2 laser pulses. Saturation of the optoacoustic signal was observed when the energy density exceeded 5 J\\/cm2. This was attributed to a change in the particle size distribution of the aerosol during a laser pulse.
Aerosol in the Pacific troposphere
NASA Technical Reports Server (NTRS)
Clarke, Antony D.
The use of near real-time optical techniques is emphasized for the measurement of mid-tropospheric aerosol over the Central Pacific. The primary focus is on measurement of the aerosol size distribution over the range of particle diameters from 0.15 to 5.0 microns that are essential for modeling CO2 backscatter values in support of the laser atmospheric wind sounder (LAWS) program. The measurement system employs a LAS-X (Laser Aerosol Spectrometer-PMS, Boulder, CO) with a custom 256 channel pulse height analyzer and software for detailed measurement and analysis of aerosol size distributions. A thermal preheater system (Thermo Optic Aerosol Descriminator (TOAD) conditions the aerosol in a manner that allows the discrimination of the size distribution of individual aerosol components such as sulfuric acid, sulfates and refractory species. This allows assessment of the relative contribution of each component to the BCO2 signal. This is necessary since the different components have different sources, exhibit independent variability and provide different BCO2 signals for a given mass and particle size. Field activities involve experiments designed to examine both temporal and spatial variability of these aerosol components from ground based and aircraft platforms.
Mount St. Helens aerosol evolution
NASA Technical Reports Server (NTRS)
Oberbeck, V. R.; Farlow, N. H.; Fong, W.; Snetsinger, K. G.; Ferry, G. V.; Hayes, D. M.
Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.
Mount St. Helens aerosol evolution
Oberbeck, V.R.; Farlow, N.H.
Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.
Mount St. Helens aerosol evolution
Oberbeck, V.R.; Farlow, N.H.; Fong, W.; Snetsinger, K.G.; Ferry, G.V.; Hayes, D.M.
Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples show that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.
7, 469497, 2007 Segregated aerosol
Paris-Sud XI, Universitķ de
of aerosols over Eastern Mediterranean: seasonal variability and comparison with AERONET columnar size are normally fine (e.g. combustion processes, biomass burning and fossil25 fuel combustion). 470 #12;ACPD 7 affected by aerosols. Indeed PM10 measurements performed at various places both in the west and the eastern
Aerosol Variability Observed with Rpas
NASA Astrophysics Data System (ADS)
Altstõdter, B.; Lampert, A.; Scholtz, A.; Bange, J.; Platis, A.; Hermann, M.; Wehner, B.
To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS) Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of T³bingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by T³bingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter). Further the aerosol size distribution in the range from about 0.300 to ~5 ?m is given by an optical particle counter.
Carbonaceous aerosol emissions from India
NASA Astrophysics Data System (ADS)
Parashar, D. C.; Gadi, Ranu; Mandal, T. K.; Mitra, A. P.
Budget estimate for carbonaceous aerosols including black carbon (BC) and organic carbon, emitted from the combustion of various fuels, is very important for regional climate studies. Emission factors for carbonaceous aerosols from bio-fuels and soft coke were determined in a controlled combustion study. The emission factors thus obtained along with those available for other fossil fuels consumed in different sectors have been applied to assess the budget for carbonaceous aerosols from India. Preliminary calculations give a range of 1.6-1.8 Tg of carbonaceous aerosols that include 0.4-1.4 Tg of BC. A major (ś80%) portion of carbonaceous aerosols emitted from India is found to originate from the use of biomass for energy as 70-80% of energy requirement in rural India is met by combustion of traditional bio-fuels.
Gastrointestinal transit measurements in mice with 99mTc-DTPA-labeled activated charcoal using NanoSPECT-CT
Background Gastrointestinal (GI) disorders are commonly associated with chronic conditions such as diabetes, obesity, and hypertension. Direct consequences are obstipation or diarrhea as opposite aspects of the irritable bowel syndrome, and more indirectly, alteration of appetite, feeling of fullness, flatulence, bloatedness, and eventually leading to altered absorption of nutrients. Moreover, GI retention and passage times have been recognized as important factors in determining the release site and hence the bioavailability of orally administered drugs. To facilitate the understanding of physiological and pathological processes involved, it is necessary to monitor the gut motility in animal models. Here, we describe a method for studying the GI transit time using technetium-labeled activated charcoal diethylenetriaminepentaacetic acid (99mTc-Ch-DTPA) detected by single-photon emission computed tomography (SPECT). Methods Tc-DTPA was adsorbed onto activated charcoal and administered orally to trypan blue-tainted (n = 4) 129SvEv mice (50 to 80 MBq/animal, n = 11). The exact distribution and movement of radioactivity in the gastrointestinal tract was measured at intervals of 1, 3, 6, 12, and 22 h by SPECT-CT. In addition, in order to validate the imaging of GI transient time, loperamide (0.25 mg/animal, n = 3) was used to delay the GI transit. Results The transit time measured as the peak radioactivity occurring in the rectum was 6 to 7 h after gavaging of 99mTc-Ch-DTPA. After 1 h, the bolus had passed into the small intestine and entered the cecum and the colon. At 6 and 8 h, the cecum, the ascending, transverse, and descending colon, and the rectum showed significant labeling. Several pellets were stored in the rectum for defecation. After 22 h, little activity remained in the stomach and none was detected in the transverse colon or other GI locations. In contrast, 6 h after administration of loperamide, only the cecum and part of the transverse colon were labeled. After 22 h, both structures retained significant amount of label. This delay has been verified by non-radiolabeled dye trypan blue GI measurements (n = 4). Conclusion Here, we present the first non-invasive study of mouse GI transit time, allowing clear differentiation between vehicle- and loperamide-treated animals. This technique is useful for the investigation of GI motility in mice. PMID:23915679
Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy.
Haar, Peter J; Broaddus, William C; Chen, Zhi-jian; Fatouros, Panos P; Gillies, George T; Corwin, Frank D
A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)(-1) in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized. PMID:20508321
Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy
NASA Astrophysics Data System (ADS)
Haar, Peter J.; Broaddus, William C.; Chen, Zhi-jian; Fatouros, Panos P.; Gillies, George T.; Corwin, Frank D.
A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)-1 in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.
SAGE II aerosol data validation based on retrieved aerosol model size distribution from SAGE II aerosol measurements
NASA Technical Reports Server (NTRS)
Wang, Pi-Huan; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.; Swissler, T. J.; Osborn, M. T.; Russell, P. B.; Oberbeck, V. R.; Livingston, J.; Rosen, J. M.
Consideration is given to aerosol correlative measurements experiments for the Stratospheric Aerosol and Gas Experiment (SAGE) II, conducted between November 1984 and July 1986. The correlative measurements were taken with an impactor/laser probe, a dustsonde, and an airborne 36-cm lidar system. The primary aerosol quantities measured by the ground-based instruments are compared with those calculated from the aerosol size distributions from SAGE II aerosol extinction measurements. Good agreement is found between the two sets of measurements.
International Cooperative for Aerosol Prediction Workshop on Aerosol Forecast Verification
NASA Technical Reports Server (NTRS)
Benedetti, Angela; Reid, Jeffrey S.; Colarco, Peter R.
The purpose of this workshop was to reinforce the working partnership between centers who are actively involved in global aerosol forecasting, and to discuss issues related to forecast verification. Participants included representatives from operational centers with global aerosol forecasting requirements, a panel of experts on Numerical Weather Prediction and Air Quality forecast verification, data providers, and several observers from the research community. The presentations centered on a review of current NWP and AQ practices with subsequent discussion focused on the challenges in defining appropriate verification measures for the next generation of aerosol forecast systems.
Gd-EOB-DTPA-Enhanced MRI for Detection of Liver Metastases from Colorectal Cancer: A Surgeon's Perspective!
Lafaro, Kelly J.; Roumanis, Panayota; Demirjian, Aram N.; Lall, Chandana; Imagawa, David K.
Colorectal cancer affects over one million people worldwide annually, with the liver being the most common site of metastatic spread. Adequate resection of hepatic metastases is the only chance for a cure in a subset of patients, and five-year survival increases to 35% with complete resection. Traditionally, computed tomographic imaging (CT) was utilized for staging and to evaluate metastases in the liver. Recently, the introduction of hepatobiliary contrast-enhanced magnetic resonance imaging (MRI) agents including gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Eovist in the United States, Primovist in Europe, or Gd-EOB-DTPA) has proved to be a sensitive method for detection of hepatic metastases. Accurate detection of liver metastases is critical for staging of colorectal cancer as well as preoperative planning. PMID:23653860
Characterization of Incidental Liver Lesions: Comparison of Multidetector CT versus Gd-EOB-DTPA-Enhanced MR Imaging
Chung, Yong Eun; Kim, Myeong-Jin; Kim, Yeo-Eun; Park, Mi-Suk; Choi, Jin Young; Kim, Ki Whang
As a result of recent developments in imaging modalities and wide spread routine medical checkups and screening, more incidental liver lesions are found frequently on US these days. When incidental liver lesions are found on US, physicians have to make a decision whether to just follow up or to undergo additional imaging studies for lesion characterization. In order to choose the next appropriate imaging modality, the diagnostic accuracy of each imaging study needs to be considered. Therefore, we tried to compare the accuracy of contrast-enhanced multidetector CT (MDCT) and Gd-EOB-DTPA-enhanced MRI for characterization of incidental liver masses. We included 127 incidentally found focal liver lesions (94 benign and 33 malignant) from 80 patients (M?F?=?45?35) without primary extrahepatic malignancy or chronic liver disease. Two radiologists independently reviewed Gd-EOB-DTPA-enhanced MRI and MDCT. The proportion of confident interpretations for differentiation of benign and malignant lesions and for the specific diagnosis of diseases were compared. The proportion of confident interpretations for the differentiation of benign and malignant lesions was significantly higher with EOB-MRI(94.5%¢97.6%) than with MDCT (74.0%¢92.9%). In terms of specific diagnosis, sensitivity and accuracy were significantly higher with EOB-MRI than with MDCT for the diagnosis of focal nodular hyperplasia (FNH) and focal eosinophilic infiltration. The diagnoses of the remaining diseases were comparable between EOB-MRI and MDCT. Hence, our results suggested that Gd-EOB-MRI may provide a higher proportion of confident interpretations than MDCT, especially for the diagnosis of incidentally found FNH and focal eosinophilic infiltration. PMID:23776623
Absorption Properties of Arctic Aerosol
NASA Astrophysics Data System (ADS)
Gao, R.; Schwarz, J. P.; Lack, D. A.; Bahreini, R.; Froyd, K. D.; Lance, S.; Spackman, J. R.; Laurel A, W.; Fahey, D. W.; Middlebrook, A. M.; Veres, P. R.; Brock, C. A.
The Arctic region is highly sensitive to global climate change. Aerosols, especially their absorption properties, have a significant potential to affect climate forcing. Accurate knowledge of aerosol absorption is critical to derive a complete set of aerosol optical properties from remote radiance measurements. We present airborne observations obtained during the NOAA-sponsored Aerosol Radiation and Cloud Processes affecting Arctic Climate (ARCPAC) campaign conducted in April 2008. The observations were made with a Particle Soot Absorption Photometer (PSAP) and a Single-Particle Soot Photometer (SP2) on the NOAA WP-3D research aircraft in flights from Fairbanks, Alaska. PSAP measures ensemble aerosol absorption and the SP2 selectively measures the refractory black carbon (rBC) content of individual particles. The correlation of PSAP and derived SP2 absorption at 530 nm is highly linear over a range of values from background to higher levels associated with biomass burning plumes. PSAP absorption on average is 23% larger than SP2 values, thereby providing strong evidence that in the Arctic 2008 springtime the dominant aerosol absorber is refractory black carbon at 530 nm and longer wavelengths. In addition, the SP2 observations show that the majority of BC mass resides in only a small subset of particles in the total aerosol population. This suggests that the retrieval algorithms for the remote sensing of atmospheric absorption such as those used by AERONET may need significant revision.
AERONET: The Aerosol Robotic Network
AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html
Aerosol growth in Titan's ionosphere.
Lavvas, Panayotis; Yelle, Roger V; Koskinen, Tommi; Bazin, Axel; Vuitton, Vķronique; Vigren, Erik; Galand, Marina; Wellbrock, Anne; Coates, Andrew J; Wahlund, Jan-Erik; Crary, Frank J; Snowden, Darci
Photochemically produced aerosols are common among the atmospheres of our solar system and beyond. Observations and models have shown that photochemical aerosols have direct consequences on atmospheric properties as well as important astrobiological ramifications, but the mechanisms involved in their formation remain unclear. Here we show that the formation of aerosols in Titan's upper atmosphere is directly related to ion processes, and we provide a complete interpretation of observed mass spectra by the Cassini instruments from small to large masses. Because all planetary atmospheres possess ionospheres, we anticipate that the mechanisms identified here will be efficient in other environments as well, modulated by the chemical complexity of each atmosphere. PMID:23382231
Aerosole und das Klimasystem: Atmosphõrenforschung
NASA Astrophysics Data System (ADS)
Feichter, Johann
Aerosolpartikel beeinflussen Wetter und Klima. Sie streuen das Sonnenlicht zur³ck in den Weltraum oder absorbieren es und bewirken damit eine Abk³hlung der Erdoberflõche. Man vermutet daher, dass die anthropogen produzierten Aerosole den anthropogen verursachten Treibhauseffekt mildern. Aerosole fungieren auch als Kondensationskerne f³r Wassertr÷pfchen und Eiskristalle, womit sie die physikalischen und optischen Eigenschaften von Wolken sowie die Verteilung der Niederschlõge beeinflussen. Um die Verteilung des Aerosols realistisch simulieren und mit dem Klimasystem zu koppeln, m³ssen die Massenverteilung, die chemische Zusammensetzung und die Gr÷▀enverteilung der Teilchen bekannt sein.
Aerosol characterization with centrifugal aerosol spectrometers: Theory and experiment
Johnson, D.L.; Martonen, T.B.
A general mathematical model describing the motion of particles in aerosol centrifuges has been developed. It has been validated by comparisons of theoretically predicted calibration sites with experimental data from tests sizing aerosols in instruments of three different spiral duct configurations. By accurately simulating factors which influence centrifuge performance, the model enhances the versatility of existing instruments and promotes CAD (computer aided design) and CAM (computer aided manufacture) of new units. The model will permit more accurate aerodynamic classifications of airborne particles. Therefore, more precise determinations of deposition sites of inhaled aerosols within the lung will be possible, since such locations are primarily functions on the dynamic characteristics of motion. U.S. EPA risk assessment protocols of pollutant aerosols will thereby be improved.
Aerosol measurement program strategy for global aerosol backscatter model development
NASA Technical Reports Server (NTRS)
Bowdle, David A.
The purpose was to propose a balanced program of aerosol backscatter research leading to the development of a global model of aerosol backscatter. Such a model is needed for feasibility studies and systems simulation studies for NASA's prospective satellite-based Doppler lidar wind measurement system. Systems of this kind measure the Doppler shift in the backscatter return from small atmospheric aerosol wind tracers (of order 1 micrometer diameter). The accuracy of the derived local wind estimates and the degree of global wind coverage for such a system are limited by the local availability and by the global scale distribution of natural aerosol particles. The discussions here refer primarily to backscatter model requirements at CO2 wavelengths, which have been selected for most of the Doppler lidar systems studies to date. Model requirements for other potential wavelengths would be similar.
Remote Sensing of Aerosol and Non-Aerosol Absorption
NASA Technical Reports Server (NTRS)
Kaufman, Y. J.; Dubovik, O.; Holben, B. N.; Remer, L. A.; Tanre, D.; Lau, William K. M. (Technical Monitor)
Remote sensing of aerosol from the new satellite instruments (e.g. MODIS from Terra) and ground based radiometers (e.g. the AERONET) provides the opportunity to measure the absorption characteristics of the ambient undisturbed aerosol in the entire atmospheric column. For example Landsat and AERONET data are used to measure spectral absorption of sunlight by dust from West Africa. Both Application of the Landsat and AERONET data demonstrate that Saharan dust absorption of solar radiation is several times smaller than the current international standards. This is due to difficulties of measuring dust absorption in situ, and due to the often contamination of dust properties by the presence of air pollution or smoke. We use the remotely sensed aerosol absorption properties described by the spectral sin le scattering albedo, together with statistics of the monthly optical thickness for the fine and coarse aerosol derived from the MODIS data. The result is an estimate of the flux of solar radiation absorbed by the aerosol layer in different regions around the globe where aerosol is prevalent. If this aerosol forcing through absorption is not included in global circulation models, it may be interpreted as anomalous absorption in these regions. In a preliminary exercise we also use the absorption measurements by AERONET, to derive the non-aerosol absorption of the atmosphere in cloud free conditions. The results are obtained for the atmospheric windows: 0.44 microns, 0.66 microns, 0.86 microns and 1.05 microns. In all the locations over the land and ocean that were tested no anomalous absorption in these wavelengths, was found within absorption optical thickness of +/- 0.005.
Comparing dry aerosol size measurements
NASA Technical Reports Server (NTRS)
Rogers, D. C.
Two instruments were used to size dry aerosols for the CCN experiments: the Naval Research Laboratory (NRL) instrument which uses an electrical mobility analyzer to separate the aerosol size fractions and a diffusion chamber to grow and count the particles and the University of Wyoming (WYO) aerosol monitoring system. Measurements from these two systems were usually found to be in agreement during the CCN Workshop. Two examples are presented to compare aerosol size distribution measurements of the two instruments: experiment 8 (monodisperse NaCl) and experiment 27 (polydisperse AgI). Differential (dN/dR) and cumulative plots are shown for both instruments for experiment 8 and experiment 27; also shown are Aitken particle measurements for comparison.
The Health Effects Research Laboratory of the U.S. Environmental Protection Agency arranged for several studies, by universities or research institutions, to gather information on health effects associated with wastewater aerosols. Five studies were conducted at wastewater treatm...
Method for producing monodisperse aerosols
Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)
An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.
Preclinical studies of [ 99mTc]DTPA-mannosyl-dextran? ? ? Supported in part by National Cancer Institute Grant CA72751 and University of California Breast Cancer Research Program Grants 2RB0018 and 4IB0051
Carl K Hoh; Anne M Wallace; David R Vera
We report the preclinical testing of a synthetic receptor-binding macromolecule, [99mTc]DTPA-mannosyl-dextran (36 kDa, 8 DTPA and 55 mannosyl units per dextran, KD = 0.12 nM), for sentinel node detection. Nonclinical safety studies included cardiac pharmacology safety studies, acute toxicology and pathology studies at 50 and 500 times the scaled human dose in both rats and rabbits after foot pad administration,
Coated bedpans: their cleaning and disinfection.
Mostafa, A. B.; Chackett, K. F.; Deverill, C. E.
This paper reports on tests of cleaning and disinfection of stainless steel bedpans which have been coated with either a silicone grease or polytetrafluoroethylene (PTFE). The coatings were applied manually using an aerosol spray (silicone grease and PTFE), and by an industrial process (PTFE). Soils used comprised (i) British Standard Soil (B.S., 1966), (ii) human serum albumin labelled with technetium-99m (HSA-Tc), and (iii) a suspension of Streptococcus faecalis in broth. Tests of cleaning and disinfection were carried out in automatic washing and steam disinfector machines. Results show that aerosol spraying impairs the cleaning process but that bedpans coated by the industrial process with PTFE are superior to uncoated bedpans. Images Plate 3 Plate 2 Plate 1 PMID:1068198
Climate forcing by anthropogenic aerosols.
Charlson, R J; Schwartz, S E; Hales, J M; Cess, R D; Coakley, J A; Hansen, J E; Hofmann, D J
Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of shortwavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes. PMID:17842894
How important is organic aerosol hygroscopicity to aerosol indirect forcing?
NASA Astrophysics Data System (ADS)
Liu, Xiaohong; Wang, Jian
Organics are among the most abundant aerosol components in the atmosphere. However, there are still large uncertainties with emissions of primary organic aerosol (POA) and volatile organic compounds (VOCs) (precursor gases of secondary organic aerosol, SOA), formation of SOA, and chemical and physical properties (e.g., hygroscopicity) of POA and SOA. All these may have significant impacts on aerosol direct and indirect forcing estimated from global models. In this study a modal aerosol module (MAM) in the NCAR community atmospheric model (CAM) is used to examine sensitivities of aerosol indirect forcing to hygroscopicity (represented by a single parameter '?' ) of POA and SOA. Our model simulation indicates that in the present-day (PD) condition changing the '?' value of POA from 0 to 0.1 increases the number concentration of cloud condensational nuclei (CCN) at supersaturation S = 0.1% by 40-80% over the POA source regions, while changing the '?' value of SOA by ▒ 50% (from 0.14 to 0.07 and 0.21) changes the CCN concentration within 40%. There are disproportionally larger changes in CCN concentration in the pre-industrial (PI) condition. Due to the stronger impact of organics hygroscopicity on CCN and cloud droplet number concentration at PI condition, global annual mean anthropogenic aerosol indirect forcing (AIF) between PD and PI conditions reduces with the increase of the hygroscopicity of organics. Global annual mean AIF varies by 0.4 W m - 2 in the sensitivity runs with the control run of - 1.3 W m - 2, highlighting the need for improved understanding of organics hygroscopicity and its representation in global models.
The tissue proton T1 and T2 response to gadolinium DTPA injection in rabbits. A potential renal contrast agent for NMR imaging.
Wolf, G L; Fobben, E S
Three different doses of gadolinium (Gd) DTPA were administered intravenously to rabbits. Cardiovascular responses and changes in blood T1 and T2 were serially followed for 15 minutes when the animals were sacrificed for in vitro measures of tissue T1 and T2. Gd-DTPA was distributed and excreted like water soluble iodinated contrast agents with large changes in blood, urine, and kidney proton relaxation. An imaging experiment confirmed the efficacy as an NMR contrast agent for renal excretion. At effective doses, no adverse effects were observed and the agent appeared to be much safer than x-ray contrast agents, but with a similar potential for clinical utility. PMID:6090336
Are anthropogenic aerosols affecting rainfall?
NASA Astrophysics Data System (ADS)
Junkermann, Wolfgang; Hacker, Jorg
Modification of cloud microphysics by anthropogenic aerosols is well known since several decades. Whether the underlying processes leads to changes in precipitation is by far less confirmed. Several different factors affect the production of rain in a way that a causality between increasing aerosol load in the atmosphere and a change of annual rainfall is very difficult to confirm. What would be expected as an effect of additional cloud condensation nuclei is a shift in the spatial and temporal rainfall distribution towards a lower number of days with low rain intensity and more frequent or more vigorous single events. In fact such a shift has been observed in several locations worldwide and has been suggested to be caused by increasing aerosol load, however, without further specification of the nature and number of the aerosols involved. Measurements of aerosols which might be important for cloud properties are extremely sparse and no long term monitoring data sets are available up to now. The problem of missing long term aerosol data that could be compared to available long term meteorological data sets can possibly be resolved in certain areas where well characterized large anthropogenic aerosol sources were installed in otherwise pristine areas without significant changes in land use over several decades. We investigated aerosol sources and current aerosol number, size and spatial distributions with airborne measurements in the planetary boundary layer over two regions in Australia that are reported to suffer from extensive drought despite the fact that local to regional scale water vapor in the atmosphere is slowly and constantly increasing. Such an increase of the total water in the planetary boundary layer would imply also an increase in annual precipitation as observed in many other locations elsewhere. The observed decline of rainfall in these areas thus requires a local to regional scale physical process modifying cloud properties in a way that rain production is delayed. We observed enhanced numbers of anthropogenic ultrafine particles and cloud condensation nuclei and are able to reconstruct also their historical development. The derived aerosol trends are well in agreement with the observed negative trends in precipitation based on the assumption that additional CCN in a first step delay the production of raindrops allowing more efficient horizontal transport to redistribute rainfall, in these cases leading to a regional loss of total rainfall.
Nanomaterials in Medicine Special Feature Sackler Colloquium: Preparation and initial characterization of biodegradable particles containing gadolinium-DTPA contrast agent for enhanced MRI
Amber L. Doiron; Kevin Chu; Adeel Ali; Lisa Brannon-Peppas
Accurate imaging of atherosclerosis is a growing necessity for timely treatment of the disease. Magnetic resonance imaging (MRI) is a promising technique for plaque imaging. The goal of this study was to create polymeric particles of a small size with high loading of diethylenetriaminepentaacetic acid gadolinium (III) (Gd-DTPA) and demonstrate their usefulness for MRI. A water-in-oil-in-oil double emulsion solvent evaporation
Dynamic Contrast-Enhanced Magnetic Resonance Imaging with Gd-EOB-DTPA for the Evaluation of Liver Fibrosis Induced by Carbon Tetrachloride in Rats
Zhang, Wei; Kong, Xiang; Wang, Zhen J.; Luo, Song; Huang, Wei; Zhang, Long Jiang
Purpose To investigate the utility of dynamic contrast-enhanced MRI (DCE-MRI) with Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) for detecting liver fibrosis induced by carbon tetrachloride (CCl4) in rats. Methods This study was approved by the institutional animal care and use committee. Liver fibrosis in rats was induced by intraperitoneal injection of 1 mL/kg 50% CCl4 twice a week for 4-13 weeks. Control rats were injected with saline. Liver fibrosis was graded using the Metaviar score: no fibrosis (F0), mild fibrosis (F1-F2) and advanced fibrosis (F3-F4). DCE-MRI with Gd-EOB-DTPA was performed for all rats. Ktrans, Kep, Ve and iAUC of the liver parenchyma were measured. Relative enhancement (RE) value of the liver was calculated on T1-weighted images at 15, 20 and 25 min after Gd-EOB-DTPA administration. Results Thirty-five rats were included: no fibrosis (n=13), mild fibrosis (n=11) and advanced fibrosis (n=11). Ktrans and iAUC values were highest in advanced fibrosis group and lowest in no fibrosis group (P?0.05). The area under the receiver operating characteristic curve (AUROC) for fibrosis (stages F1 and greater) were 0.773 and 0.882 for Ktrans and iAUC, respectively. AUROC for advanced fibrosis were 0.835 and 0.867 for Ktrans and iAUC, respectively. Kep and RE values were not able to differentiate fibrosis stages (all P?0.05). Conclusion Ktrans and iAUC obtained from DCE-MRI with Gd-EOB-DTPA are useful for the detection and staging of rat liver fibrosis induced by CCl4. PMID:26076199
Removal of Co(II) and Ni(II) ions from contaminated water using silica gel functionalized with EDTA and/or DTPA as chelating agents.
Repo, Eveliina; Kurniawan, Tonni Agustiono; Warchol, Jolanta K; Sillanpõõ, Mika E T
In this study, the removal of Co(II) and Ni(II) ions from contaminated water was investigated using silica gel materials functionalized with both ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA). The modified adsorbents were characterized using elemental analysis, surface area and pore size analysis, and zeta potential analysis. The adsorption and regeneration studies were conducted in batch mode. The optimum conditions for the removal of both metals at an initial concentration of 10mg/L were 2g/L of dose, pH 3, 50 rpm of agitation speed and 4h of contact time. The removal of Co(II) and Ni(II) by EDTA- and/or DTPA-modified silica gels was substantially higher than that by their unmodified form. The maximum Co(II) and Ni(II) uptakes by the EDTA-modified silica gel were 20.0 and 21.6 mg/g, comparable to their adsorption capacities by DTPA-modified silica gel (Co(II): 16.1mg/g; Ni(II): 16.7 mg/g). At the same concentration of 10mg/L, the removal of both metals by the modified adsorbents ranged from 96% to 99%. The two-site Langmuir model was representative to simulate adsorption isotherms. The kinetics of Co(II) and Ni(II) adsorption by modified silica gels followed pseudo-second-order. PMID:19632777
Aerosol optical properties during the Lindenberg Aerosol Characterization Experiment (LACE 98)
U. Bundke; G. Hõnel; H. Horvath; W. Kaller; S. Seidl; H. Wex; A. Wiedensohler; M. Wiegner; V. Freudenthaler
The optical properties of atmospheric aerosol particles were measured close to ground level using different methods at Lindenberg\\/Falkenberg (Germany) during the Lindenberg Aerosol Characterization Experiment (LACE 98), 13 July 1998 to 14 August 1998 [Ansmann et al., 2002]. The experimental setup consisted of (a) an aerosol photometer, which measured a complete set of aerosol optical properties, such as extinction, scattering,
Early diagnosis and regional evaluation of radiation mucositis by newly developed TC-99M DTPA labelled agent
Tamamura, H.; Ohguchi, M.; Higashi, K. [Kanazawa Medical Univ., Ishikawa (Japan)] [and others
We have developed a new drug for treating acute radiation mucositis which consists of a steroid with potent localized anti-inflammatory effect, and sodium alginate with strong adherence to mucosal surface, and since then we have treated many patients with success. In the present study, we labelled this agent with Tc-99m DTPA, and administered to 10 healthy volunteers and 35 patients with acute radiation mucositis, and determined the values of mean transit time (MTT) and T1/2 from the dynamic phase and the time taken for the mixture to reach to cardia according to Talliefer`s method. Abnormal radionuclide (RN) accumulation in the esophagus was evaluated at 10 minutes after the administration and, the ratio of abnormal RN accumulation count were calculated. In the healthy volunteers, the MTT was 2.67 seconds, T1/2 14.0 seconds, and the time for the drug to reach the stomach 5.25 seconds. Even in the patients with acute radiation mucositis, these values were not significantly different from the healthy controls. However, the images taken at 10 minutes after the administration revealed abnormal RN accumulation corresponding to the irradiated region in all patients. The ratio of this abnormal RN accumulation to the total RN count in the esophagus was 52.48%, the pre-administration RN ratio was 6.45%. None of the healthy volunteers produced abnormal RN accumulation. The ratio of total RN count in the esophagus to pre-administration RN count was only 1.87% in the healthy volunteers, whereas 11.39% in the radiation mucositis group. When Tc-99m DTPA-labelled water was used similarly, the region of radiation esophagitis was not identified on scintigraphy. It was thus suggested that diagnosis of radiation mucositis could be made only with this new agent of high viscosity and very strong mucous adhesive property. Owing to its repeatability and simplicity, this new agent seemed to be useful to make the early diagnosis and regional evaluation of radiation mucositis possible.
The Effect of Aerosol Hygroscopicity and Volatility on Aerosol Optical Properties During Southern Oxidant and Aerosol Study
NASA Astrophysics Data System (ADS)
Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.
Secondary organic aerosol (SOA) from biogenic sources can influence optical properties of ambient aerosol by altering its hygroscopicity and contributing to light absorption directly via formation of brown carbon and indirectly by enhancing light absorption by black carbon ("lensing effect"). The magnitude of these effects remains highly uncertain. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of relative humidity and temperature on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). The sample-conditioning system provided measurements at ambient RH, 10%RH ("dry"), 85%RH ("wet"), and 200 C ("TD"). In parallel to these measurements, a long residence time temperature-stepping thermodenuder (TD) and a variable residence time constant temperature TD in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. We will present results of the on-going analysis of the collected data set. We will show that both temperature and relative humidity have a strong effect on aerosol optical properties. SOA appears to increase aerosol light absorption by about 10%. TD measurements suggest that aerosol equilibrated fairly quickly, within 2 s. Evaporation varied substantially with ambient aerosol loading and composition and meteorology.
The Mpi-M Aerosol Climatology (MAC)
NASA Astrophysics Data System (ADS)
Kinne, S.
Monthly gridded global data-sets for aerosol optical properties (AOD, SSA and g) and for aerosol microphysical properties (CCN and IN) offer a (less complex) alternate path to include aerosol radiative effects and aerosol impacts on cloud-microphysics in global simulations. Based on merging AERONET sun-/sky-photometer data onto background maps provided by AeroCom phase 1 modeling output and AERONET sun-/the MPI-M Aerosol Climatology (MAC) version 1 was developed and applied in IPCC simulations with ECHAM and as ancillary data-set in satellite-based global data-sets. An updated version 2 of this climatology will be presented now applying central values from the more recent AeroCom phase 2 modeling and utilizing the better global coverage of trusted sun-photometer data - including statistics from the Marine Aerosol network (MAN). Applications include spatial distributions of estimates for aerosol direct and aerosol indirect radiative effects.
Schwartz, Stephen E.
, November 11-13, 2008 #12;OVERVIEW Aerosol radiative forcings: magnitudes and uncertainties CCSP - SAP 2.3 Ł Path forward: Traditional approach CCSP - SAP 2.3 Ł Definition of aerosol radiative forcing Dimensions
Stratospheric Aerosol and Gas Experiment (SAGE II)
NASA Technical Reports Server (NTRS)
Mcmaster, L. R.
Design features and the performance envelope of the SAGE II stratospheric aerosol monitoring instrument on the Earth Radiation Budget Satellite are described. SAGE II was designed to obtain vertical profiles of stratospheric aerosols, monitor global seasonal changes in aerosols, provide data on stratospheric circulation and the behavior of transient events such as volcanic particulate injections, and to investigate atmospheric chemistry. The mmeasurements are centered on extinctions due to aerosols, NO2, O3 and water vapor.
Climate forcing by carbonaceous and sulfate aerosols
J. E. Penner; C. C. Chuang; K. Grant
An atmospheric general circulation model is coupled to an atmospheric chemistry model to calculate the radiative forcing\\u000a by anthropogenic sulfate and carbonaceous aerosols. The latter aerosols result from biomass burning as well as fossil fuel\\u000a burning. The black carbon associated with carbonaceous aerosols is absorbant and can decrease the amount of reflected radiation\\u000a at the top-of-the-atmosphere. In contrast, sulfate aerosols
Systematic aerosol characterization by combining UV Aerosol Indices with trace gas concentrations
NASA Astrophysics Data System (ADS)
Penning de Vries, Marloes; Beirle, Steffen; H÷rmann, Christoph; Kaiser, Johannes W.; Tilstra, Gijsbert; Tuinder, Olaf; Stammes, Piet; Wagner, Thomas
Measurements of aerosol optical thickness (AOT) from ground-based, airborne, and satellite-borne instruments show us that aerosols are ubiquitous and highly variable throughout the globe. But for the calculation of aerosol radiative effects, for the development and monitoring of mitigation strategies, and for the construction of climatologies of aerosol optical properties (needed for, e.g., AOT retrievals) knowledge of aerosol type (and/or source) is also of importance. Detecting the optical properties of aerosols from passive satellite-borne measurements alone is a difficult task due to the rather smooth effect that aerosols have on measured spectra and the influences of surface and cloud reflection. We therefore chose another approach to determine aerosol type: by studying the relationship of AOT with trace gas abundance, aerosol absorption, and mean aerosol size. Our Global Aerosol Classification Algorithm, GACA, examines monthly mean maps of aerosol properties (MODIS AOT and extinction Angstrom exponent, GOME-2 UV Aerosol Indices) and trace gas column densities (NO2, HCHO, SO2 from GOME-2, and CO from MOPITT) for temporal correlations. First, aerosol types are assigned based on size (Angstrom exponent) and absorption (UV Aerosol Indices), then the main sources are inferred by performing threshold tests (for mean trace gas columns) and correlation tests (between AOT and trace gas columns) on the data set. We present global aerosol climatologies of aerosol type (ranging from small, non-absorbing to large, absorbing aerosols) for different seasons, as well as maps of aerosol sources (e.g., biomass burning, urban, or biogenic). The results from GACA are compared to aerosol types modeled using MACC-II.
3, 59195976, 2003 The nitrate aerosol
Paris-Sud XI, Universitķ de
ACPD 3, 5919Ł5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page Abstract/5919/ ® European Geosciences Union 2003 Atmospheric Chemistry and Physics Discussions The nitrate aerosol firstname.lastname@example.com) 5919 #12;ACPD 3, 5919Ł5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page
Stratospheric Aerosol Measurement (SAM 2) experiment
NASA Technical Reports Server (NTRS)
Mccormick, M. P.; Mauldin, L. E., III; Mcmasters, L. R.; Chu, W. P.; Swissler, T.
The Stratospheric Aerosol Measurement 2 (SAM 2) is used to map the concentration and optical properties of stratospheric aerosols as a function of altitude, latitude, and longitude. The vertical distribution of the stratospheric aerosols in the polar regions of both hemispheres is provided.
Secondary Organic Aerosol Formation: New Insights
R. M. Kamens; M. Jang; S. Lee; N. Czoschke; S. Leungsakul; D. Hu
A discussion of some of the important issues related to secondary organic aerosol (SOA) formation is presented, and SOA formation is placed in a context of global fine aerosol sources. Outdoor smog chamber experiments are described for the purposes of exploring the effects of different types of background aerosols on SOA formation from the reaction of alpha -pinene with NOx
6, 30993133, 2006 Aerosol extinction-to-
Paris-Sud XI, Universitķ de
ACPD 6, 3099Ł3133, 2006 Aerosol extinction-to- backscatter ratio by lidar and MODIS Q. S. He et al Chemistry and Physics Discussions A study on aerosol extinction-to-backscatter ratio with combination;ACPD 6, 3099Ł3133, 2006 Aerosol extinction-to- backscatter ratio by lidar and MODIS Q. S. He et al
Estimating aerosol hazards from an anthrax letter
J. Ho; S. Duncan
Events following the anthrax letter incidences in 2001 changed many previously held assumptions regarding biological aerosol hazards. As there were significant fatalities resulting from the sorting of a single anthrax letter, it suggests there is a need to reevaluate how best to measure biological aerosols and to use the information to make accurate predictions. This paper describes the biological aerosol
Experimental study of diffusion charging of aerosols
Pui; D. Y. H
The electrical charging of aerosol particles by unipolar gaseous ions was studied theoretically and experimentally. The primary objective of the study was to make precise determinations of the aerosol particle charge under various conditions of charging and to compare the experimental results with those predicted by theory. Experiments were performed using monodisperse oleic acid aerosols generated by a vibrating orifice
6, 55855628, 2006 Change in aerosol
Paris-Sud XI, Universitķ de
Chemistry and Physics Discussions Change in global aerosol composition since preindustrial times K that focuses on aerosol chemical composition change since preindustrial times con-5 sidering the secondary differently when their chem- ical composition changes. According to this study, the aerosol composition
ATI TDA 5A aerosol generator evaluation
Gilles, D.A.
Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.
Chemical Properties of Combustion Aerosols: An Overview
A wide variety of pyrogenic and anthropogenic sources emit fine aerosols to the atmosphere. The physical and chemical properties of these aerosols are of interest due to their influence on climate, human health, and visibility. Aerosol chemical composition is remarkably complex. ...
The steam-jet aerosol collector
A. Khlystov; G. P. Wyers; J. Slanina
A new principle of sampling aerosol particles by means of steam injection with the consequent collection of grown droplets has been established. An air stream free of water-soluble gases is rapidly mixed with steam. The resulting supersaturation causes aerosol particles to grow into droplets. The droplets containing dissolved aerosol species are then collected by two cyclones in series. The solution
Secondary Organic Aerosol Formation by Heterogeneous
Goddard III, William A.
partitioning from gas to particle phase and, hence, increase the organic particulate material (OPM). Aerosol as to the likely aerosol-phase chemical reactions involving ab- sorbed gas-phase organic compounds. ThSecondary Organic Aerosol Formation by Heterogeneous Reactions of Aldehydes and Ketones: A Quantum
Angstrom exponent and bimodal aerosol size distributions
Gregory L. Schuster; Oleg Dubovik; Brent N. Holben
Power laws have long been used to describe the spectral dependence of aerosol extinction, and the wavelength exponent of the aerosol extinction law is commonly referred to as the Angstrom exponent. The Angstrom exponent is often used as a qualitative indicator of aerosol particle size, with values greater than 2 indicating small particles associated with combustion byproducts, and values less
Registration of parametric dynamic F-18-FDG PET/CT breast images with parametric dynamic Gd-DTPA breast images
NASA Astrophysics Data System (ADS)
Magri, Alphonso; Krol, Andrzej; Lipson, Edward; Mandel, James; McGraw, Wendy; Lee, Wei; Tillapaugh-Fay, Gwen; Feiglin, David
This study was undertaken to register 3D parametric breast images derived from Gd-DTPA MR and F-18-FDG PET/CT dynamic image series. Nonlinear curve fitting (Levenburg-Marquardt algorithm) based on realistic two-compartment models was performed voxel-by-voxel separately for MR (Brix) and PET (Patlak). PET dynamic series consists of 50 frames of 1-minute duration. Each consecutive PET image was nonrigidly registered to the first frame using a finite element method and fiducial skin markers. The 12 post-contrast MR images were nonrigidly registered to the precontrast frame using a free-form deformation (FFD) method. Parametric MR images were registered to parametric PET images via CT using FFD because the first PET time frame was acquired immediately after the CT image on a PET/CT scanner and is considered registered to the CT image. We conclude that nonrigid registration of PET and MR parametric images using CT data acquired during PET/CT scan and the FFD method resulted in their improved spatial coregistration. The success of this procedure was limited due to relatively large target registration error, TRE = 15.1+/-7.7 mm, as compared to spatial resolution of PET (6-7 mm), and swirling image artifacts created in MR parametric images by the FFD. Further refinement of nonrigid registration of PET and MR parametric images is necessary to enhance visualization and integration of complex diagnostic information provided by both modalities that will lead to improved diagnostic performance.
Strategy to use the Terra Aerosol Information to Derive the Global Aerosol Radiative Forcing of Climate
NASA Technical Reports Server (NTRS)
Kaufman, Yoram J.; Tanre, Didier; Einaudi, Franco (Technical Monitor)
Terra will derive the aerosol optical thickness and properties. The aerosol properties can be used to distinguish between natural and human-made aerosol. In the polar orbit Terra will measure aerosol only once a day, around 10:30 am. How will we use this information to study the global radiative impacts of aerosol on climate? We shall present a strategy to address this problem. It includes the following steps: - From the Terra aerosol optical thickness and size distribution model we derive the effect of aerosol on reflection of solar radiation at the top of the atmosphere. In a sensitivity study we show that the effect of aerosol on solar fluxes can be derived 10 times more accurately from the MODIS data than derivation of the optical thickness itself. Applications to data over several regions will be given. - Using 1/2 million AERONET global data of aerosol spectral optical thickness we show that the aerosol optical thickness and properties during the Terra 10:30 pass are equivalent to the daily average. Due to the aerosol lifetime of several days measurements at this time of the day are enough to assess the daily impact of aerosol on radiation. - Aerosol impact on the top of the atmosphere is only part of the climate question. The INDOEX experiment showed that addressing the impact of aerosol on climate, requires also measurements of the aerosol forcing at the surface. This can be done by a combination of measurements of MODIS and AERONET data.
Spatial variability of soil total and DTPA-extractable cadmium caused by long-term application of phosphate fertilizers, crop rotation, and soil characteristics.
Jafarnejadi, A R; Sayyad, Gh; Homaee, M; Davamei, A H
Increasing cadmium (Cd) accumulation in agricultural soils is undesirable due to its hazardous influences on human health. Thus, having more information on spatial variability of Cd and factors effective to increase its content on the cultivated soils is very important. Phosphate fertilizers are main contamination source of cadmium (Cd) in cultivated soils. Also, crop rotation is a critical management practice which can alter soil Cd content. This study was conducted to evaluate the effects of long-term consumption of the phosphate fertilizers, crop rotations, and soil characteristics on spatial variability of two soil Cd species (i.e., total and diethylene triamine pentaacetic acid (DTPA) extractable) in agricultural soils. The study was conducted in wheat farms of Khuzestan Province, Iran. Long-term (27-year period (1980 to 2006)) data including the rate and the type of phosphate fertilizers application, the respective area, and the rotation type of different regions were used. Afterwards, soil Cd content (total or DTPA extractable) and its spatial variability in study area (400,000 ha) were determined by sampling from soils of 255 fields. The results showed that the consumption rate of di-ammonium phosphate fertilizer have been varied enormously in the period study. The application rate of phosphorus fertilizers was very high in some subregions with have extensive agricultural activities (more than 95 kg/ha). The average and maximum contents of total Cd in the study region were obtained as 1.47 and 2.19 mg/kg and DTPA-extractable Cd as 0.084 and 0.35 mg/kg, respectively. The spatial variability of Cd indicated that total and DTPA-extractable Cd contents were over 0.8 and 0.1 mg/kg in 95 and 25 % of samples, respectively. The spherical model enjoys the best fitting and lowest error rate to appraise the Cd content. Comparing the phosphate fertilizer consumption rate with spatial variability of the soil cadmium (both total and DTPA extractable) revealed the high correlation between the consumption rate of P fertilizers and soil Cd content. Rotation type was likely the main effective factor on variations of the soil DTPA-extractable Cd contents in some parts (eastern part of study region) and could explain some Cd variation. Total Cd concentrations had significant correlation with the total neutralizing value (p < 0.01), available P (p < 0.01), cation exchange capacity (p < 0.05), and organic carbon (p < 0.05) variables. The DTPA-extractable Cd had significant correlation with OC (p < 0.01), pH, and clay content (p < 0.05). Therefore, consumption rate of the phosphate fertilizers and crop rotation are important factors on solubility and hence spatial variability of Cd content in agricultural soils. PMID:22948289
Risk assessment for acid aerosols
Albert, R.E. (Univ. of Cincinnati Medical Center, OH (USA))
The author provides some insights from carcinogen risk assessment that apply to acid aerosols. The greatest need is to understand mechanisms of action as the basis for characterizing dose response relationships at low levels of exposure. Risk assessment is an orderly assembly of the evidence with some agreed upon guidelines as to how to make judgments about the nature (qualitative assessment) and magnitude (quantitative assessment) of health hazards. Risk assessment provides guidance for regulation, but the impetus for regulation comes from public pressure to remedy perceived health problems. There are some sharp contrasts between carcinogens and acid aerosols in terms of risk assessment and management. The regulatory objective for carcinogens is to diminish the tremendous load of cancer mortality as the second leading cause of death. In the case of acid aerosols, the regulatory objective is less pressing: to eliminate mortality among the moribund from heart and pulmonary disease and the prevention of acute impairments of pulmonary function and acute respiratory infections.
Real time infrared aerosol analyzer
Johnson, Stanley A. (Countryside, IL); Reedy, Gerald T. (Bourbonnais, IL); Kumar, Romesh (Naperville, IL)
Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.
Numerical Modelling of Gelating Aerosols
Babovsky, Hans [Institute of Mathematics, Ilmenau University of Technology, Weimarer Str. 25, D-98693 Ilmenau (Germany)
The numerical simulation of the gel phase transition of an aerosol system is an interesting and demanding task. Here, we follow an approach first discussed in [6, 8] which turns out as a useful numerical tool. We investigate several improvements and generalizations. In the center of interest are coagulation diffusion systems, where the aerosol dynamics is supplemented with diffusive spreading in physical space. This leads to a variety of scenarios (depending on the coagulation kernel and the diffusion model) for the spatial evolution of the gelation area.
Metrological support for aerosol radiometers: Special aerosol sources
S. K. Belkina; Yu. E. Zalmanzon; Yu. V. Kuznetsov; D. E. Fertman
the calibration and testing of instruments in their mass-production stages are performed, as a rule, by means of standard solid sources with allowance for the so-called conversion factor from the external radiation of the standard solid source to the volume activity of the aerosols. This practice has largely justified itself at a definite stage in the development of the instrument
Aerosol generation by raindrop impact on soil
NASA Astrophysics Data System (ADS)
Joung, Young Soo; Buie, Cullen R.
Aerosols are investigated because of their significant impact on the environment and human health. To date, windblown dust and sea salt from sea spray through bursting bubbles have been considered the chief mechanisms of environmental aerosol dispersion. Here we investigate aerosol generation from droplets hitting wettable porous surfaces including various classifications of soil. We demonstrate that droplets can release aerosols when they influence porous surfaces, and these aerosols can deliver elements of the porous medium to the environment. Experiments on various porous media including soil and engineering materials reveal that knowledge of the surface properties and impact conditions can be used to predict when frenzied aerosol generation will occur. This study highlights new phenomena associated with droplets on porous media that could have implications for the investigation of aerosol generation in the environment.
Treatment of Peritoneal Carcinomatosis by Targeted Delivery of the Radio-Labeled Tumor Homing Peptide 213Bi-DTPA-[F3]2 into the Nucleus of Tumor Cells
Miederer, Matthias; Blechert, Birgit; Vallon, Mario; M³ller, Jan M.; Alke, Andrea; Seidl, Christof; Bruchertseifer, Frank; Morgenstern, Alfred; Senekowitsch-Schmidtke, Reingard; Essler, Markus
Background ?-particle emitting isotopes are effective novel tools in cancer therapy, but targeted delivery into tumors is a prerequisite of their application to avoid toxic side effects. Peritoneal carcinomatosis is a widespread dissemination of tumors throughout the peritoneal cavity. As peritoneal carcinomatosis is fatal in most cases, novel therapies are needed. F3 is a tumor homing peptide which is internalized into the nucleus of tumor cells upon binding to nucleolin on the cell surface. Therefore, F3 may be an appropriate carrier for ?-particle emitting isotopes facilitating selective tumor therapies. Principal Findings A dimer of the vascular tumor homing peptide F3 was chemically coupled to the ?-emitter 213Bi (213Bi-DTPA-[F3]2). We found 213Bi-DTPA-[F3]2 to accumulate in the nucleus of tumor cells in vitro and in intraperitoneally growing tumors in vivo. To study the anti-tumor activity of 213Bi-DTPA-[F3]2 we treated mice bearing intraperitoneally growing xenograft tumors with 213Bi-DTPA-[F3]2. In a tumor prevention study between the days 4¢14 after inoculation of tumor cells 6ū1.85 MBq (50 ĄCi) of 213Bi-DTPA-[F3]2 were injected. In a tumor reduction study between the days 16¢26 after inoculation of tumor cells 6ū1.85 MBq of 213Bi-DTPA-[F3]2 were injected. The survival time of the animals was increased from 51 to 93.5 days in the prevention study and from 57 days to 78 days in the tumor reduction study. No toxicity of the treatment was observed. In bio-distribution studies we found 213Bi-DTPA-[F3]2 to accumulate in tumors but only low activities were found in control organs except for the kidneys, where 213Bi-DTPA-[F3]2 is found due to renal excretion. Conclusions/Significance In conclusion we report that 213Bi-DTPA-[F3]2 is a novel tool for the targeted delivery of ?-emitters into the nucleus of tumor cells that effectively controls peritoneal carcinomatosis in preclinical models and may also be useful in oncology. PMID:19479088
The MODIS Aerosol Algorithm, Products and Validation
NASA Technical Reports Server (NTRS)
Remer, L. A.; Kaufman, Y. J.; Tanre, D.; Mattoo, S.; Chu, D. A.; Martins, J. V.; Li, R.-R.; Ichoku, C.; Levy, R. C.; Kleidman, R. G.
The MODerate resolution Imaging Spectroradiometer (MODIS) aboard both NASA's Terra and Aqua satellites is making near global daily observations of the earth in a wide spectral range. These measurements are used to derive spectral aerosol optical thickness and aerosol size parameters over both land and ocean. The aerosol products available over land include aerosol optical thickness at three visible wavelengths, a measure of the fraction of aerosol optical thickness attributed to the fine mode and several derived parameters including reflected spectral solar flux at top of atmosphere. Over ocean, the aerosol optical thickness is provided in seven wavelengths from 0.47 microns to 2.13 microns. In addition, quantitative aerosol size information includes effective radius of the aerosol and quantitative fraction of optical thickness attributed to the fine mode. Spectral aerosol flux, mass concentration and number of cloud condensation nuclei round out the list of available aerosol products over the ocean. The spectral optical thickness and effective radius of the aerosol over the ocean are validated by comparison with two years of AERONET data gleaned from 133 AERONET stations. 8000 MODIS aerosol retrievals colocated with AERONET measurements confirm that one-standard deviation of MODIS optical thickness retrievals fall within the predicted uncertainty of delta tauapproximately equal to plus or minus 0.03 plus or minus 0.05 tau over ocean and delta tay equal to plus or minus 0.05 plus or minus 0.15 tau over land. 271 MODIS aerosol retrievals co-located with AERONET inversions at island and coastal sites suggest that one-standard deviation of MODIS effective radius retrievals falls within delta r_eff approximately equal to 0.11 microns. The accuracy of the MODIS retrievals suggests that the product can be used to help narrow the uncertainties associated with aerosol radiative forcing of global climate.
The efficacies of pure LICAM(C) and DTPA on the retention of plutonium-238 and americium-241 in rats after their inhalation as nitrate and intravenous injection as citrate.
Stradling, G N; Stather, J W; Gray, S A; Moody, J C; Ellender, M; Hodgson, A; Volf, V; Taylor, D M; Wirth, P; Gaskin, P W
The pure carboxylated catechoyl amide LICAM(C) and the calcium and zinc salts of diethylenetriaminepenta-acetic acid (DTPA), were tested for efficacy for removing 238Pu and 241Am from rats after inhalation of the nitrate or intravenous injection of the citrate. The results were compared with the efficacy of methylated LICAM(C) used in previous experiments. It was shown that: (1) after inhalation of 238Pu nitrate, DTPA was far superior to pure LICAM(C); (2) after intravenous injection of 238Pu citrate, the infusion of DTPA plus LICAM(C) was only marginally more effective than DTPA alone; and (3) after inhalation or intravenous injection of 238Pu plus 241Am, the efficacy of pure LICAM(C) was only marginally more effective than the methylated form and neither form was effective for the decorporation of 241Am. It was concluded that DTPA, at present, remains the chelating agent of choice for treating persons accidentally contaminated with transportable forms of Pu and Am. PMID:2571662
MAESTRO Measurements of Atmospheric Aerosol
NASA Astrophysics Data System (ADS)
McElroy, Tom; Drummond, James; Zou, Jason
MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) is now in its 11th year on orbit as part of the Atmospheric Chemistry Experiment on the Canadian Space Agency's SCISAT satellite. MAESTRO data analysis has been dogged by a deficiency in accurate timing between the measurements made by the partner instrument, the ACE-FTS (Atmospheric Chemistry Experiment, Fourier Transform Spectrometer), that provides the atmospheric pressure-temperature profile and observation tangent altitudes used in the MAESTRO data analysis. Attempts have been made to use apparent air column density and oxygen A-band absorption as a mechanism to line up the tangent heights, but to no avail. A new product is now being produced, based on matching the modeled ozone slant columns from the ACE-FTS retrievals with the MAESTRO slant column measurements. The approach is very promising and indicates that a valuable product from the MAESTRO wavelength-dependent aerosol extinction likely result. The usefulness of the profile matching technique will be demonstrated and some aerosol absorption profiles will be presented in comparison with measurements made by the ACE Imager aerosol profile results. While the process optimizes the comparison between ACE-FTS ozone profile data and that from MAESTRO, it does not detract from the higher vertical resolution information provided by MAESTRO.
Fixed beds of sorbent media are used for the evaluation of polynuclear aromatic hydrocarbons (PAH) present in air. wo-stage sampling and separate extraction and analyses of PAH associated with aerosol particles and those present in the vapor state are usually performed. he abilit...
Detection of chemical agent aerosols
Jay A. Fox; Jeffrey L. Ahl; Francis M. D'Amico; Richard G. Vanderbeek; Raphael Moon; Cynthia R. Swim
One of the major threats presented by a chemical agent attack is that of a munition exploding overhead and 'raining' aerosols which can contaminate surfaces when they impact. Since contact with these surfaces can be fatal, it is imperative to know when such an attack has taken place and the likely threat density and location. We present the results of
Crystallography of metallic aerosol precipitates
E. R. Buckle; K. C. Pointon; P. Tsakiropoulos
In a previous paper it was concluded from microscopical evidence that the radius of a basal raft nucleated on a freezing droplet of Zn or Cd expands to a fixed fraction of the droplet radius before thickening into a grain. Further studies on polycrystalline spheres from condensation aerosols, together with observations by other investigators working with much larger, sessile drops,
Description of Aerosol Dynamicsby the
of just the lower-order . radial moments of the size distribution. These lower-order moments are often suf with the moments obtained from simulations using the MOM. The kth radial moment of an aerosol size distribution is defined as where f(r) is the distribution function for the number density of particles having radii
Characterization of aerosols containing microcystin.
Cheng, Yung Sung; Zhou, Yue; Irvin, C Mitch; Kirkpatrick, Barbara; Backer, Lorraine C
Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 mum. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ. PMID:18463733
Solid particulate aerosol fire suppressants
Charles J. Kibert; Douglas Dierdorf
A variety of private and public sector programs are developing a new class of fire suppressants, known generically as solid particulate aerosols. These have superior volumetric efficiency, low initial and life-cycle costs, low toxicity, no known global atmospheric environmental impacts (ODP\\/GWP), and the potential for a wide variety of applications. Researchers are developing solid compound formulations that, when pyrotechnically initiated,
6, 1286512893, 2006 Aerosol size
Paris-Sud XI, Universitķ de
, FS-Polarstern, during a transect from Bremerhaven in northern Germany, to Cape Town in South Africa to air mass history, wind speed and latitude. Under clean marine conditions, the averaged size to the10 mechanical generation of marine aerosol over the range of wind speeds observed. A new technique
NASA Technical Reports Server (NTRS)
Torres, Omar
2012-13 Report of research on aerosol and cloud remote sensing using UV observations. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center, May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocentr website, after the meeting.
This report documents the discussions and results of the U.S. Environmental Protection Agency's (EPA's) Acid Aerosol Measurement Method intercomparison Workshop, held April 10-11, 1991 in Research Triangle Park, NC. he workshop was designed to achieve two objectives: (1) to repor...
6, 1191311956, 2006 Aerosols distribution
Paris-Sud XI, Universitķ de
Simon Laplace/Service d'A┤eronomie, UPMC/UVSQ/CNRS, Paris, France 3 Institut National de l'Environnement Industriel et des Risques, INERIS, Verneuil en Halatte, France 4 National Center for Atmospheric Research and on precipitation. The spatial distribution of aerosols was documented by means of the airborne lidar LEANDRE-2
Immunization by a bacterial aerosol.
Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; Derousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R; Miller, Rich; Fourie, P Bernard; Hickey, Anthony; Edwards, David
By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried "nanomicroparticle" vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette-Guķrin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG. PMID:18344320
Immunization by a bacterial aerosol
Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; DeRousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R.; Miller, Rich; Fourie, P. Bernard; Hickey, Anthony; Edwards, David
By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried ōnanomicroparticleö vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette¢Guķrin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG. PMID:18344320
5, 179215, 2005 Global aerosol
Paris-Sud XI, Universit├® de
A GLObal Model of Aerosol Processes (GLOMAP) has been developed as an exten- sion to the TOMCAT 3-D Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Print Version Interactive References Tables Figures Back Close Full Screen / Esc Print Version Interactive Discussion EGU Abstract
Characterization of Aerosols Containing Microcystin
Cheng, Yung Sung; Zhou, Yue; Irvin, C. Mitch; Kirkpatrick, Barbara; Backer, Lorraine C.
Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 ?m. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ. PMID:18463733
5, 10671114, 2005 Physical aerosol
Paris-Sud XI, Universitķ de
associated with separate groups of chemical compounds (ions, organic matter, dust, BC). For what concerns the-soluble organic matter is not known. The data suggest that WSOM is slightly-to-moderately hygroscopic The presented physical measurements finally allow us to provide a partitioning of the sub-Ąm aerosol in four non
[Aerosol disinfection of bacterial spores].
Theilen, U; Wilsberg, F J; B÷hm, R; Strauch, D
The present investigations are divided into two parts. First it is tested which commercial disinfectants are efficient in aerosol disinfection of bacterial spores. This part is carried out in an aerosol chamber with airborne spores (laboratory experiments). The best results are obtained with peracetic acid, hydrogen peroxide and formaldehyde are effective with some restrictions. With these disinfectants it is tested in the second part if the aerosol disinfecting-method is capable for disinfecting rooms with electronic equipment. This part is carried out in a vessel under open air conditions (field experiments). Bacterial spores dried on germ carriers of limewood, aluminium and rusty iron are exposed to disinfectant aerosols under those temperature and relative humidity conditions which are representative for the four seasons in Germany. In these investigations there are also included germ carriers with spores, that have been lyophilized without any protective substances respectively with Bentonite, Mixtura desiccans and Silicagel + Serum as protective substances. To check the corrosive effect of disinfectant aerosols electronic pocket calculators and pocket transistor receivers have been exposed to the aerosols. The best results are obtained with formaldehyde at temperatures above 10 degrees C and relative humidities within 65% to 95%. At temperatures and relative humidity conditions outside of this optimal range the effectiveness of formaldehyde tends to zero. Hydrogen peroxide is capable for disinfecting spores on germ carriers of limewood and aluminium at all temperature and relative humidity conditions; on germ carriers of rusty iron the effectiveness is reduced strongly. Same results could be obtained with peracetic acid respectively a mixture of peracetic acid and hydrogen peroxide. With these disinfectants a decontamination of rusty iron surfaces is impossible too except the germ concentration on the surface is below 10(4) CFU/cm2. As to the protective substances used in the lyophilization process Bentonite and Mixtura desiccans cause hardly any change in the disinfectant resistance of bacterial spores. Silicagel + Serum in comparison to that protects the imbedded spores that far, that no disinfection of these germ carriers was achieved with the oxidizing agents. As about 15 disinfection runs with each disinfectant did not cause permanent damages to the pocket calculators and transistor receivers it can be emphasized as result of these investigations that aerosol disinfection is an effective method in disinfecting rooms with electronic equipment under middle European climate conditions.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3116785
Calculation of electrical conductivity from ion-aerosol balance equations
Savita Dhanorkar; A. K. Kamra
The ion-aerosol balance equations are solved to study the effect of aerosol concentration on electrical conductivity for different ionization rates taking bimodal lognormal size distribution for the grand average continental aerosol particles and using size dependent attachment and coagulation coefficients for the aerosol particles. The results show that the inverse relationship between the polar conductivity and aerosol concentration exists only
Metabolism of plutonium introduced as Tri-N-Butylphosphate complex in the rat and removal attempts by DTPA.
Metivier, H; Masse, R; Lafuma, J
The metabolism of plutonium introduced as the Pu-Tri-N-Butylphosphate complex (Pu-TBP) was studied in rats after inhalation, injection and ingestion. Early translocation and distribution of 239Pu in organs for 30-400 days after inhalation exposure are presented. The tracheobronchial clearance was impaired at early times, followed from about one week by clearance from the deep lung as characterized by a half time of 100 days. Skeleton was the main organ for deposition of the transferable fraction. The bone burden reached a plateau value of 10% of Initial Lung Burden (ILB) at 50 days after inhalation, while retention in liver reached 2% of ILB at 50 days and decreased to 0.3% by 1 yr after inhalation. Thirty days after intramuscular injection, translocated plutonium (15% of injected activity) resulted in a skeletal deposit that was 17.5 times higher than the deposit in the liver. By both routes, inhalation and intramuscular injection, 239Pu was transported in the blood as a Pu-transferrin complex. However, therapy with 30 mumol . kg-1 DTPA was ineffective. This result, together with the magnitude of the skeletal deposit observed, indicate that Pu-TBP follows a specific metabolic pathway that results in a Pu-transferrin complex that is more stable than the complexes described after Pu nitrate or citrate contamination. Lastly, absorption of Pu-TBP from the gut was poor, reaching 0.015% of the Pu given by gavage, a value not significantly different from the values assumed by ICRP 30 for class W compounds. PMID:6853185
[Magnetic resonance imaging of bladder tumors: superiority of serial "Fast SE" assisted by Gd-DTPA in tumor staging].
Tanimoto, A; Yuasa, Y; Endo, M; Ohkawa, S; Shiraga, N; Fujisawa, H; Ido, K; Ogawa, K; Momoshima, S; Shiga, H
Eighteen cases with bladder tumors were examined by means of superconducting MRI. Sequences used were spin echo (TR/TE (msec) = 500/20 as T1WI (weighted image) and 1500/80 as T2WI) and serial "fast spin echo (fast SE)" pre/post Gd-DTPA administration. "Fast SE" was a new technique offering a distinct T1WI (TR/TE = 100/14, utilizing a 14 second breath hold). Slice thickness of "fast SE" was 10 mm and slice plane was selected perpendicular to the tumor base to detect the extent of invasion. Serial scan of "fast SE" was performed before and immediately after 0.1 mmol/kg Gd administration. Scanning was completed before the bladder was opacified by Gd. Tumor and normal mucosa were both markedly enhanced whereas the surrounding muscle layer remained hypointense. On delayed scan, the elevated character of the tumor was outlined by opacified urine but the distinction between the mucosa and the muscle layer became unclear. Total cystectomy (TC) was performed in 6 of 18 cases and pathological tumor extension was correlated with MR findings. Transurethral resection (TUR) was performed in the remaining 12 patients, and the tumor extension was assessed by follow-up biopsy after TUR. Intact liner hypointensity indicated superficial lesions (= less than pT2), while disruption of the linear hypointensity corresponded pathologically to deep muscle invasion (= greater than pT3a). Accuracy of serial "fast SE" in tumor staging was 94% (17/18). Serial "fast SE" allowed the distinction of superficial from invasive tumors more accurately than conventional studies, and therefore assisted in choosing the correct operative method. PMID:2633133
Semi-automatic detection of Gd-DTPA-saline filled capsules for colonic transit time assessment in MRI
NASA Astrophysics Data System (ADS)
Harrer, Christian; Kirchhoff, Sonja; Keil, Andreas; Kirchhoff, Chlodwig; Mussack, Thomas; Lienemann, Andreas; Reiser, Maximilian; Navab, Nassir
Functional gastrointestinal disorders result in a significant number of consultations in primary care facilities. Chronic constipation and diarrhea are regarded as two of the most common diseases affecting between 2% and 27% of the population in western countries 1-3. Defecatory disorders are most commonly due to dysfunction of the pelvic floor or the anal sphincter. Although an exact differentiation of these pathologies is essential for adequate therapy, diagnosis is still only based on a clinical evaluation1. Regarding quantification of constipation only the ingestion of radio-opaque markers or radioactive isotopes and the consecutive assessment of colonic transit time using X-ray or scintigraphy, respectively, has been feasible in clinical settings 4-8. However, these approaches have several drawbacks such as involving rather inconvenient, time consuming examinations and exposing the patient to ionizing radiation. Therefore, conventional assessment of colonic transit time has not been widely used. Most recently a new technique for the assessment of colonic transit time using MRI and MR-contrast media filled capsules has been introduced 9. However, due to numerous examination dates per patient and corresponding datasets with many images, the evaluation of the image data is relatively time-consuming. The aim of our study was to develop a computer tool to facilitate the detection of the capsules in MRI datasets and thus to shorten the evaluation time. We present a semi-automatic tool which provides an intensity, size 10, and shape-based 11,12 detection of ingested Gd-DTPA-saline filled capsules. After an automatic pre-classification, radiologists may easily correct the results using the application-specific user interface, therefore decreasing the evaluation time significantly.
Double labelling of human umbilical cord mesenchymal stem cells with Gd-DTPA and PKH26 and the influence on biological characteristics of hUCMSCs.
Shuai, Hanlin; Shi, Changzheng; Lan, Jifa; Chen, Danliang; Luo, Xin
The aim of this study was to determine whether double labelling of human umbilical cord mesenchymal stem cells (hUCMSCs) with gadolinium-diethylene triamine penta-acetic acid (Gd-DTPA) and PKH26 influences their biological characteristics. A tissue adherence technique was used to separate and purify the hUCMSCs and flow cytometry was performed to detect the surface markers expressed on them. Gd-DTPA and PKH26 were used to label the stem cells and MRI and fluorescence microscopy were used to detect the double-labelled hUCMSCs. A MTT assay was used to delineate the growth curve. Transmission electron microscopy (TEM) and atomic force microscopy were used to demonstrate the ultrastructural features of the hUCMSCs. Flow cytometry showed that hUCMSCs highly expressed CD29, CD90, CD44 and CD105. No expression of CD31, CD34 and CD45 was detected. Very low expression of HLA-DR and CD40 was detected. Atomic force microscopy showed these cells were long, spindle shaped, and the cytoplasm and nucleus had clear boundaries. After double labelling, TEM showed Gd particles aggregated in the cytoplasm in a cluster pattern. The proliferation activity, cell cycle, apoptosis and differentiation of the stem cells were not influenced by double labelling. Thus a tissue adherence technique is helpful to separate and purify hUCMSCs effectively; and Gd-DTPA and PKH26 are promising tracers in the investigation of migration and distribution of hUCMSCs in vivo. PMID:25649907
Immune memory to hepatitis B virus in 4-9-year old children vaccinated in infancy with four doses of hexavalent DTPa-HBV-IPV/Hib vaccine.
Zinke, Michael; Kappes, Rudolf; Kindler, Klaus; Paulus-Koschik, Anke; Goering, Uwe; Disselhoff, Johann; Soemantri, Peter; Grunert, Detlef; Laakmann, Karl Heinz; Gunasekaran, Ramakrishnan; Gartner, Britta; Jacquet, Jeanne-Marie
The combined hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio Haemophilus influenzae type b (DTPa-HBV-IPV/Hib) vaccine produces similar hepatitis B responses as the HBV monovalent vaccine. Booster vaccination of immunocompetent individuals primed against hepatitis B in infancy is currently not recommended. We investigated persisting immunity to hepatitis B in 4-6 (Study A; 106745) and 7-9 (Study B; 106744) year-old children primed in infancy and boosted in the second year of life with DTPa-HBV-IPV/Hib. Immunity was assessed by measuring persisting anti-HBs antibodies and evaluating the response to a challenge dose of HBV vaccine. At 4-6 years of age 86.0% of 186 subjects had persisting anti-HBs > or =10 mIU/ml increasing to 98.4% after the challenge. At 7-9 years of age, 78.0% of 186 subjects continued to have anti-HBs antibody concentrations > or =10 mIU/ml, increasing to 98.9% after the challenge. In both studies anti-HBs antibody GMC rose >80-fold. An anamnestic response to the HBV challenge was observed in 95.7% and 98.9% of subjects in Studies A and B, respectively. In both studies, 87% of 38 subjects with initially undetectable circulating anti-HBs antibodies (>3.3 IU/ml) achieved the 10 mIU/ml threshold after challenge; > or =97.0% of subjects with detectable antibodies before the challenge at least quadrupled their concentration. Post-vaccination anti-HBs concentrations were directly related to persisting antibody concentrations and the concentrations achieved after the booster dose in the second year of life. The HBV vaccine challenge dose was well tolerated. These studies show that primary and booster vaccination with combined DTPa-HBV-IPV/Hib (Infanrix hexa) induces sustained immune memory against hepatitis B up to age 9 years. PMID:19535920
Aerosol optical absorption measurements with photoacoustic spectroscopy
NASA Astrophysics Data System (ADS)
Liu, Kun; Wang, Lei; Liu, Qiang; Wang, Guishi; Tan, Tu; Zhang, Weijun; Chen, Weidong; Gao, Xiaoming
Many parameters related to radiative forcing in climate research are known only with large uncertainties. And one of the largest uncertainties in global radiative forcing is the contribution from aerosols. Aerosols can scatter or absorb the electromagnetic radiation, thus may have negative or positive effects on the radiative forcing of the atmosphere, respectively [1]. And the magnitude of the effect is directly related to the quantity of light absorbed by aerosols [2,3]. Thus, sensitivity and precision measurement of aerosol optical absorption is crucial for climate research. Photoacoustic spectroscopy (PAS) is commonly recognized as one of the best candidates to measure the light absorption of aerosols [4]. A PAS based sensor for aerosol optical absorption measurement was developed. A 532 nm semiconductor laser with an effective power of 160 mW was used as a light source of the PAS sensor. The PAS sensor was calibrated by using known concentration NO2. The minimum detectable optical absorption coefficient (OAC) of aerosol was determined to be 1 Mm-1. 24 hours continues measurement of OAC of aerosol in the ambient air was carried out. And a novel three wavelength PAS aerosol OAC sensor is in development for analysis of aerosol wavelength-dependent absorption Angstrom coefficient. Reference [1] U. Lohmann and J. Feichter, Global indirect aerosol effects: a review, Atmos. Chem. Phys. 5, 715-737 (2005) [2] M. Z. Jacobson, Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols, Nature 409, 695-697 (2001) [3] V. Ramanathan and G. Carmichae, Global and regional climate changes due to black carbon, nature geoscience 1, 221-227 (2008) [4] W.P Arnott, H. Moosmuller, C. F. Rogers, T. Jin, and R. Bruch, Photoacoustic spectrometer for measuring light absorption by aerosol: instrument description. Atmos. Environ. 33, 2845-2852 (1999).
Physicochemical Characterization of Capstone Depleted Uranium Aerosols I: Uranium Concentration in Aerosols as a Function of Time and Particle Size
MaryAnn Parkhurst; Yung-Sung Cheng; Judson L. Kenoyer; Richard J. Traub
During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing depleted uranium were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol
In vivo transport of Gd-DTPA2- into human meniscus and cartilage assessed with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC)
Background Impaired stability is a risk factor in knee osteoarthritis (OA), where the whole joint and not only the joint cartilage is affected. The meniscus provides joint stability and is involved in the early pathological progress of OA. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been used to identify pre-radiographic changes in the cartilage in OA, but has been used less commonly to examine the meniscus, and then using only a double dose of the contrast agent. The purpose of this study was to enable improved early OA diagnosis by investigate the temporal contrast agent distribution in the meniscus and femoral cartilage simultaneously, in healthy volunteers, using 3D dGEMRIC at two different doses of the contrast agent Gd-DTPA2-. Methods The right knee in 12 asymptomatic volunteers was examined using a 3D Look-Locker sequence on two occasions after an intravenous injection of a double or triple dose of Gd-DTPA2- (0.2 or 0.3Āmmol/kg body weight). The relaxation time (T1) and relaxation rate (R1?=?1/T1) were measured in the meniscus and femoral cartilage before, and 60, 90, 120 and 180Āminutes after injection, and the change in relaxation rate (?R1) was calculated. Paired t-test and Analysis of Variance (ANOVA) were used for statistical evaluation. Results The triple dose yielded higher concentrations of Gd-DTPA2- in the meniscus and cartilage than the double dose, but provided no additional information. The observed patterns of ?R1 were similar for double and triple doses of the contrast agent. ?R1 was higher in the meniscus than in femoral cartilage in the corresponding compartments at all time points after injection. ?R1 increased until 90-180 minutes in both the cartilage and the meniscus (p?0.05), and was lower in the medial than in the lateral meniscus at all time points (p?0.05). A faster increase in ?R1 was observed in the vascularized peripheral region of the posterior medial meniscus, than in the avascular central part of the posterior medial meniscus during the first 60Āminutes (p?0.05). Conclusion It is feasible to examine undamaged meniscus and cartilage simultaneously using dGEMRIC, preferably 90Āminutes after the injection of a double dose of Gd-DTPA2- (0.2Āmmol/kg body weight). PMID:25005036
Multiple hepatocellular adenomas in a patient with glycogen storage disease type I: various enhancement patterns in MRI with Gd-EOB-DTPA
Ayami Sakamoto; Hideyuki Hayashi; Ichiro Sakamoto; Ichiro Isomoto; Susumu Eguchi; Mitsuhisa Takatsuki; Tatsuki Ichikawa; Kuniko Abe; Tomayoshi Hayashi; Masataka Uetani
The patient is a 20-year-old man with glycogen storage disease type I (GSD-type I). In his teens, multiple focal hepatic masses\\u000a were detected on abdominal ultrasonography (US), which were diagnosed as multiple hepatocellular adenomas from the imaging.\\u000a During follow-up, these masses had shown intermittent growth in size. In the evaluation of Gd-EOB-DTPA (gadolinium-ethoxybenzyl-diethylenetriamine\\u000a penta-acetic acid) MR imaging, these masses showed
Cellular Zn depletion by metal ion chelators (TPEN, DTPA and chelex resin) and its application to osteoblastic MC3T3-E1 cells
Cho, Young-Eun; Lomeda, Ria-Ann R.; Ryu, Sang-Hoon; Lee, Jong-Hwa; Beattie, John H.
Trace mineral studies involving metal ion chelators have been conducted in investigating the response of gene and protein expressions of certain cell lines but a few had really focused on how these metal ion chelators could affect the availability of important trace minerals such as Zn, Mn, Fe and Cu. The aim of the present study was to investigate the availability of Zn for the treatment of MC3T3-E1 osteoblast-like cells and the availability of some trace minerals in the cell culture media components after using chelexing resin in the FBS and the addition of N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN, membrane-permeable chelator) and diethylenetriaminepentaacetic acid (DTPA, membrane-impermeable chelator) in the treatment medium. Components for the preparation of cell culture medium and Zn-treated medium have been tested for Zn, Mn, Fe and Cu contents by atomic absorption spectrophotometer or inductively coupled plasma spectrophotometer. Also, the expression of bone-related genes (ALP, Runx2, PTH-R, ProCOL I, OPN and OC) was measured on the cellular Zn depletion such as chelexing or TPEN treatment. Results have shown that using the chelexing resin in FBS would significantly decrease the available Zn (p<0.05) (39.4 ▒ 1.5 ĄM vs 0.61 ▒ 10.15 ĄM) and Mn (p<0.05) (0.74 ▒ 0.01 ĄM vs 0.12 ▒ 0.04 ĄM). However, levels of Fe and Cu in FBS were not changed by chelexing FBS. The use of TPEN and DTPA as Zn-chelators did not show significant difference on the final concentration of Zn in the treatment medium (0, 3, 6, 9, 12 ĄM) except for in the addition of higher 15 ĄM ZnCl2 which showed a significant increase of Zn level in DTPA-chelated treatment medium. Results have shown that both chelators gave the same pattern for the expression of the five bone-related genes between Zn- and Zn+, and TPEN-treated experiments, compared to chelex-treated experiment, showed lower bone-related gene expression, which may imply that TPEN would be a stronger chelator than chelex resin. This study showed that TPEN would be a stronger chelator compared to DTPA or chelex resin and TPEN and chelex resin exerted cellular zinc depletion to be enough for cell study for Zn depletion. PMID:20535382
Improved understanding of aerosol processes using satellite observations of aerosol optical propertiesĀ
Bulgin, Claire Elizabeth
Atmospheric aerosols are the largest remaining uncertainty in the EarthÆs radiative budget and it is important that we improve our knowledge of aerosol processes if we are to understand current radiative forcing and ...
Ozonolysis of maleic acid aerosols: effect upon aerosol hygroscopicity, phase and mass.
Pope, F D; Gallimore, P J; Fuller, S J; Cox, R A; Kalberer, M
The hygroscopicity and mass loss of aerosols initially composed of maleic acid have been investigated before and after reaction with ozone. The phase of the aerosol, solid or aqueous, during the reaction with ozone strongly affects the composition of the processed aerosol. Furthermore the loss of aerosol mass, via the production of volatile ozonolysis products, does not occur until the processed aerosol has existed as an aqueous phase aerosol. The loss rate of the aerosol mass appears to follow unimolecular first order kinetics which is consistent with the rate determining step being the cleavage of a weak hydroperoxide, or peroxide, bond (approximately 104 kJ mol(-1)). This speculative rate determining step, which is not based on chemical analysis, is possibly a universal feature in the ozonolysis of organic aerosol containing the alkene functionality. PMID:20701273
CCN activity of aliphatic amine secondary aerosol
NASA Astrophysics Data System (ADS)
Tang, X.; Price, D.; Praske, E.; Vu, D.; Purvis-Roberts, K.; Silva, P. J.; Cocker, D. R., III; Asa-Awuku, A.
Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, ? ? 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N2O5 (source of nitrate radical, NO3), contains less volatile compounds than the primary aliphatic amine (BA) aerosol. TMA + N2O5 form semi-volatile organics in low RH conditions that have ? ~ 0.20, indicative of slightly soluble organic material. As RH increases, several inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. Higher CCN activity (? > 0.3) was also observed for humid BA+N2O5 aerosols compared with dry aerosol (? ~ 0.2), as a result of the formation of inorganic salts such as NH4NO3 and butylamine nitrate (C4H11N Ę HNO3). Compared with TMA, BA+N2O5 reactions produce more volatile aerosols. The BA+N2O5 aerosol products under humid experiments were found to be very sensitive to the temperature within the stream-wise continuous flow thermal gradient CCN counter. The CCN counter, when set above a 21 ░C temperature difference, evaporates BA+N2O5 aerosol formed at RH ? 30%; ? ranges from 0.4 to 0.7 and is dependent on the instrument supersaturation (ss) settings. The aerosol behaves non-ideally, hence simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems ? ranges from 0.2 < ? < 0.7. This work indicates that aerosols formed via nighttime reactions with amines are likely to produce hygroscopic and volatile aerosol whereas photochemical reactions with OH produce secondary organic aerosol of lower CCN activity. Thermal gradient CCN counters measurement will impact the observed CCN activity of volatile aerosol formed via a nitric acid pathway. The contributions of semi-volatile secondary organic and inorganic material from aliphatic amines must be considered for accurate hygroscopicity and CCN predictions from aliphatic amine systems.
CCN closure and composition analysis of droplet-forming aerosol
Friedman, Beth
Cloud condensation nuclei, aerosol chemical composition, and aerosol size measurements were determined at a field site subject to a variety of aerosol sources. A pumped counterflow virtual impactor was utilized to directly ...
Part I of this report discusses the U.S. aerosol industry's experience in converting from chlorofluorocarbon (CFC) propellants to alternative aerosol formulations. Detailed examples of non-CFC formulations are provided for 28 categories of aerosol products. ydrocarbon propellants...
How thermodynamic environments control stratocumulus microphysics and interactions with aerosols
NASA Astrophysics Data System (ADS)
Andersen, Hendrik; Cermak, Jan
Aerosol¢cloud interactions are central to climate system changes and depend on meteorological conditions. This study identifies distinct thermodynamic regimes and proposes a conceptual framework for interpreting aerosol effects. In the analysis, ten years (2003¢2012) of daily satellite-derived aerosol and cloud products are combined with reanalysis data to identify factors controlling Southeast Atlantic stratocumulus microphysics. Considering the seasonal influence of aerosol input from biomass burning, thermodynamic environments that feature contrasting microphysical cloud properties and aerosol¢cloud relations are classified. While aerosol impact is stronger in unstable environments, it is mostly confined to situations with low aerosol loading (aerosol index AI ? 0.15), implying a saturation of aerosol effects. Situations with high aerosol loading are associated with weaker, seasonally contrasting aerosol-droplet size relationships, likely caused by thermodynamically induced processes and aerosol swelling.
Coupled IMPACT aerosol and NCAR CAM3 model: Evaluation of predicted aerosol number and size distribution
Minghuai Wang; Joyce E. Penner; Xiaohong Liu
Simulated aerosol fields from a coupled aerosol\\/atmospheric circulation model that includes prediction of both sulfate aerosol size and number are evaluated. Sensitivity tests are used to evaluate uncertainties due to the inclusion of primary emitted particulate sulfate as a means of representing nucleation of particles in subgrid-scale plumes, the use of two boundary layer aerosol nucleation mechanisms, and a three-mode
Aerosol Modeling for the Global Model Initiative
NASA Technical Reports Server (NTRS)
Weisenstein, Debra K.; Ko, Malcolm K. W.
The goal of this project is to develop an aerosol module to be used within the framework of the Global Modeling Initiative (GMI). The model development work will be preformed jointly by the University of Michigan and AER, using existing aerosol models at the two institutions as starting points. The GMI aerosol model will be tested, evaluated against observations, and then applied to assessment of the effects of aircraft sulfur emissions as needed by the NASA Subsonic Assessment in 2001. The work includes the following tasks: 1. Implementation of the sulfur cycle within GMI, including sources, sinks, and aqueous conversion of sulfur. Aerosol modules will be added as they are developed and the GMI schedule permits. 2. Addition of aerosol types other than sulfate particles, including dust, soot, organic carbon, and black carbon. 3. Development of new and more efficient parameterizations for treating sulfate aerosol nucleation, condensation, and coagulation among different particle sizes and types.
Aerosol volatility in a boreal forest environment
NASA Astrophysics Data System (ADS)
Hõkkinen, S. A. K.; ?ijõlõ, M.; Lehtipalo, K.; Junninen, H.; Virkkula, A.; Worsnop, D. R.; Kulmala, M.; Petõjõ, T.; Riipinen, I.
Climate and health effects of atmospheric aerosols are determined by their properties such as their chemical composition. Aerosol chemical composition can be studied indirectly by measuring volatility of aerosol particles. The volatility of submicron aerosol particles (20-500 nm) was studied in a boreal forest site at SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations II) station (Vesala et al., 1998) in Hyytiõlõ, Finland, during 01/2008-05/2010. The instrument used for the measurements was VDMPS (Volatility Differential Mobility Particle Sizer), which consists of two separate instruments: DMPS (Differential Mobility Particle Sizer, Aalto et al., 2001) and TD (Thermodenuder, Wehner et al., 2002). Aerosol evaporation was examined by heating the aerosol and comparing the total aerosol mass before and after heating. In the VDMPS system ambient aerosol sample was heated up to temperatures ranging from 80 ░C to 280 ░C. The higher the heating temperature was the more aerosol material was evaporated. There was a non-volatile residual present in aerosol particles when heated up to 280 ░C. This residual explained (20▒8)% of the total aerosol mass. Aerosol non-volatile mass fraction was highest during winter and smallest during summer months. The role of black carbon in the observed non-volatile residual was determined. Black carbon explained 40 to 90% of the non-volatile mass. Especially during colder seasons noticeable amount of non-volatile material, something else than black carbon, was observed. According to Kalberer et al. (2004) some atmospheric organic species can form polymers that have high evaporation temperatures. Also low-volatile organic salts may contribute to the non-volatile aerosol (Smith et al., 2010). Aerosol mass composition measured directly with AMS (Aerosol Mass Spectrometer, Jayne et al., 2000) was analyzed in order to examine the properties of the non-volatile material (other than black carbon). The AMS measurements were performed during spring and autumn 2008. Results from the aerosol mass spectrometry indicate that the non-volatile residual consists of nitrate and organic compounds, especially during autumn. These compounds may be low-volatile organic nitrates or salts. During winter and spring the non-volatile core (black carbon removed) correlated markedly with carbon monoxide, which is a tracer of anthropogenic emissions. Due to this, the non-volatile residual may also contain other pollutants in addition to black carbon. Thus, it seems that the amount of different compounds in submicron aerosol particles varies with season and as a result the chemical composition of the non-volatile residual changes within a year. This work was supported by University of Helsinki three-year research grant No 490082 and Maj and Tor Nessling Foundation grant No 2010143. Aalto et al., (2001). Physical characterization of aerosol particles during nucleation events. Tellus B, 53, 344-358. Jayne, et al., (2000). Development of an aerosol mass spectrometer for size and composition analysis of submicron particles. Aerosol Sci. Technol., 33(1-2), 49-70. Kalberer et al., (2004). Identification of Polymers as Major Components of Atmospheric Organic Aerosols. Science, 303, 1659-1662. Smith et al., (2010). Observations of aminium salts in atmospheric nanoparticles and possible climatic implications. P. Natl. Acad. Sci., 107(15). Vesala et al., (1998). Long-term field measurements of atmosphere-surface interactions in boreal forest combining forest ecology, micrometeorology, aerosol physics and atmospheric chemistry. Trends Heat, Mass Mom. Trans., 4, 17-35. Wehner et al., (2002). Design and calibration of a thermodenuder with an improved heating unit to measure the size-dependent volatile fraction of aerosol particles. J. Aerosol Sci., 33, 1087-1093.
Aerosol Lidar and MODIS Satellite Comparisons for Future Aerosol Loading Forecast
NASA Technical Reports Server (NTRS)
DeYoung, Russell; Szykman, James; Severance, Kurt; Chu, D. Allen; Rosen, Rebecca; Al-Saadi, Jassim
Knowledge of the concentration and distribution of atmospheric aerosols using both airborne lidar and satellite instruments is a field of active research. An aircraft based aerosol lidar has been used to study the distribution of atmospheric aerosols in the California Central Valley and eastern US coast. Concurrently, satellite aerosol retrievals, from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 aerosol data product provides retrieved ambient aerosol optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 sq km resolution) and the aerosol scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the aerosols to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar aerosol and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of aerosols near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the aerosols are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer aerosol pollution events.
Estimation of aerosol water and chemical composition from POLDER/PARASOL satellite retrievals of aerosol properties.
NASA Astrophysics Data System (ADS)
van Beelen, Arjan; Roelofs, Geert-Jan; Hasekamp, Otto; R÷ckmann, Thomas
Remote sensing of aerosols provides important information on the atmospheric aerosol abundance. Due to the hygroscopic nature of aerosol particles, their optical properties reflect not only the dry aerosol properties but are also influenced by atmospheric humidity. Remotely sensed aerosol optical properties are used to validate aerosol-climate models, but a more consistent validation requires knowledge of the actual aerosol dry chemical composition. We present results from a model that estimates the dry aerosol chemical composition and aerosol water, using remotely sensed aerosol properties from POLDER/PARASOL (e.g. optical thickness, single scattering albedo, refractive index and size distribution) and ECMWF relative humidity as input. The model applies a minimization technique to derive column-integrated quantities of sulfate, ammonium nitrate, sea salt, organic matter, black carbon and dust, for the aerosol fine and coarse modes. First, we compare POLDER data with data from AERONET to assess the accuracy and consistency of the input data, and discuss the influence of uncertainties in optical parameters (especially the refractive index) on the model results. Then, the model is applied to POLDER measurements at several near-oceanic sites. The results are used to investigate the monthly and seasonal variability of aerosol abundance and composition at these sites.
Sensitivity of TOMS aerosol index to boundary layer height: Implications for detection of mineral aerosol sources
Mahowald, Natalie
Sensitivity of TOMS aerosol index to boundary layer height: Implications for detection of mineral) is proposed as a powerful tool in determining the sources of mineral aerosols. The sensitivity of the AI to the height of the aerosol layer has been noted previously, but the implications of this sensitivity
Quantification of aerosol type, and sources of aerosols over the Indo-Gangetic Plain
NASA Astrophysics Data System (ADS)
Kedia, Sumita; Ramachandran, S.; Holben, B. N.; Tripathi, S. N.
Differences and similarities in aerosol characteristics, for the first time, over two environmentally distinct locations in Indo-Gangetic plain (IGP) - Kanpur (KPR) (urban location) and Gandhi College (GC) (rural site) are examined. Aerosol optical depths (AODs) exhibit pronounced seasonal variability with higher values during winter and premonsoon. Aerosol fine mode fraction (FMF) and ┼ngstr÷m exponent (?) are higher over GC than KPR indicating relatively higher fine mode aerosol concentration over GC. Higher FMF over GC is attributed to local biomass burning activities. Analysis of AOD spectra revealed that aerosol size distribution is dominated by wide range of fine mode fractions or mixture of modes during winter and postmonsoon, while during premonsoon and monsoon coarse mode aerosols are more abundant. Single scattering albedo (SSA) is lower over GC than KPR. SSA spectra reveals the abundance of fine mode (coarse mode) absorbing (scattering) aerosols during winter and postmonsoon (premonsoon and monsoon). Spectral SSA features reveal that OC contribution to enhanced absorption is negligible. Analysis shows that absorbing aerosols can be classified as Mostly Black Carbon (BC), and Mixed BC and Dust over IGP. Mixed BC and dust is always higher over KPR, while Mostly BC is higher over GC throughout the year. The amount of long range transported dust exhibits a gradient between KPR (higher) and GC (lower). Results on seasonally varying aerosol types, and absorbing aerosol types and their gradients over an aerosol hotspot are important to tune models and to reduce the uncertainty in radiative and climate impact of aerosols.
An emerging ground-based aerosol climatology: Aerosol optical depth from AERONET
B. N. Holben; D. Tanrķ; A. Smirnov; T. F. Eck; I. Slutsker; N. Abuhassan; W. W. Newcomb; J. S. Schafer; B. Chatenet; F. Lavenu; Y. J. Kaufman; J. Vande Castle; A. Setzer; B. Markham; D. Clark; R. Frouin; R. Halthore; A. Karneli; N. T. O'Neill; C. Pietras; R. T. Pinker; K. Voss; G. Zibordi
Long-term measurements by the AERONET program of spectral aerosol optical depth, precipitable water, and derived Angstrom exponent were analyzed and compiled into an aerosol optical properties climatology. Quality assured monthly means are presented and described for 9 primary sites and 21 additional multiyear sites with distinct aerosol regimes representing tropical biomass burning, boreal forests, midlatitude humid climates, midlatitude dry climates,
Aerosol light scattering properties at Cape Grim, Tasmania, during the First Aerosol Characterization Experiment (ACE 1)
Christian M. Carrico; Mark J. Rood; John A. Ogren
Large uncertainties remain in understanding the effects of ambient aerosols on climate. As part of the First Aerosol Characterization Experiment (ACE 1, November 15 to December 15, 1995), the total light scattering and backscattering coefficients by particles (cysp and CYbsp) were measured at Cape Grim, Tasmania. Such measurements were made to characterize aerosol radiative forcing relevant to climate change at
Aerosol lidar intercomparison in the framework of the EARLINET project. 2. Aerosol backscatter algorithms
Christine B÷ckmann; Ulla Wandinger; Albert Ansmann; Jens B÷senberg; Vassilis Amiridis; Antonella Boselli; Arnaud Delaval; Ferdinando de Tomasi; Max Frioud; Ivan Videnov Grigorov; Matej Horvat; Marco Iarlori; Leonce Komguem; Stephan Kreipl; Volker Matthias; Alexandros Papayannis; Gelsomina Pappalardo; Francesc Rocadenbosch; Jose Ant¾nio Rodrigues; Johannes Schneider; Valery Shcherbakov; Matthias Wiegner
An intercomparison of aerosol backscatter lidar algorithms was performed in 2001 within the framework of the European Aerosol Research Lidar Network to Establish an Aerosol Climatology (EARLINET). The objective of this research was to test the correctness of the algorithms and the influence of the lidar ratio used by the various lidar teams involved in the EARLINET for calculation of
Stratospheric aerosol optical depths, 1850-1990
Sato, M.; Hansen, J.E.; Mccormick, M.P.; Pollack, J.B. [NASA, Goddard Institute of Space Studies, New York, NY (United States)]|[NASA, Langley Research Center, Hampton, VA (United States)]|[NASA, Ames Research Center, Moffett Field, CA (United States)
A global stratospheric aerosol database employed for climate simulations is described. For the period 1883-1990, aerosol optical depths are estimated from optical extinction data, whose quality increases with time over that period. For the period 1850-1882, aerosol optical depths are more crudely estimated from volcanological evidence for the volume of ejecta from major known volcanoes. The data set is available over Internet.
Stratospheric aerosol optical depths, 1850-1990
NASA Technical Reports Server (NTRS)
Sato, Makiko; Hansen, James E.; Mccormick, M. Patrick; Pollack, James B.
A global stratospheric aerosol database employed for climate simulations is described. For the period 1883-1990, aerosol optical depths are estimated from optical extinction data, whose quality increases with time over that period. For the period 1850-1882, aerosol optical depths are more crudely estimated from volcanological evidence for the volume of ejecta from major known volcanoes. The data set is available over Internet.
Design criteria for centripeter aerosol samplersĀ
King, Connie Hazel
Aerosol Samplers. (August, 1977) Connie Hazel King, B. S. , Texas Tech University Chairman of Advisory Committee: Dr. Andrew R. McFarland Aerosol of uniformly sized particles produced by a monodisperse vibrating orifice aerosol generator was sampled...- lection efficiency. The Stokes number corresponding to the particle size for which collection efficiency of the sampler is 50K, (Stk0 5), ranged from 0. 388 to 0, 398 for the three nozzle shapes tested. An increase in acceleration nozzle to collection...
Characteristics of aerosol acidity in Hong Kong
Ravi Kant Pathak; Peter K. K. Louie; Chak K. Chan
The ammonium-to-sulfate ratio ([NH4+]\\/[SO42?]) and the strong acidity have been generally used as parameters to describe the acidic nature of atmospheric aerosols. However, both parameters do not provide the in situ acidic characteristics of atmospheric aerosols, which are more relevant to the reactivity and the environmental impacts of the aerosols. In this study, the in situ free acid concentrations and
Engineering of aerosol nanoparticle architectures
Xingmao Jiang
Aerosol-assisted evaporation-induced self-assembly has been applied to fabricate a wide range of nanoparticle architectures. Ordered core-shell Ce\\/silica particles are effective for corrosion inhibition of aluminum alloy AA2024-T3. Higher hydrophobicity derived by increasing methyltrimethoxysilane\\/tetramethoxysilane ratio in the precursor delays the release in water and improves the hydrothermal stability significantly. Long-term corrosion inhibition can be realized using microporous encapsulating materials. A mathematical
Aerosols Over Yellow Sea Sediments
NASA Technical Reports Server (NTRS)
This SeaWiFS image shows complex phytoplankton distribution patterns in the Bohai and Yellow seas. A wide band of brownish water along the coast north and south of the mouth of the Yangtze River indicates a heavy load of suspended sediment. The air over eastern central China and the Yellow Sea is thick with aerosols. Farther north over the Manchurian Plain and Greater Khingan Range, the air is much clearer.
Atmospheric evolution of organic aerosol
M. J. Molina; A. V. Ivanov; S. Trakhtenberg; L. T. Molina
We report here results of an experimental study of the OH-initiated oxidation of solid organics in the presence of O2, NOx and H2O, using two kinds of self-assembled organic monolayers (alkane and aromatic), paraffin and pyrene films as proxies for organic aerosol. We show that the OH-initiated oxidation of the alkane surfaces leads to rapid volatilization. The gas-phase products detected
Aerosol Optical Properties Observed during CHAPS
NASA Astrophysics Data System (ADS)
Berg, L. K.; Berkowitz, C. M.; Ogren, J. A.; Andrews, E.; Hubbe, J. M.; Lee, Y.; Yu, X.
During the CHAPS, the DOE Gulfstream-1 aircraft was used to make in-situ measurements of aerosol optical properties. The flight pattern was designed to allow for measurements below cloud, within the cloud layer, and above the clouds in the vicinity of Oklahoma City. Two different inlets were used on the G-1: an isokinetic inlet for sampling dry aerosols smaller than approximately 2 ?m in diameter, and a Counterflow Virtual Impactor (CVI) that excluded unactivated aerosols, but which allows cloud droplets to enter. A suite of paired instruments, including a nephelometer, Particle Soot Absorption Photometer (PSAP), and Aerosol Mass Spectrometer (AMS), was used to measure the aerosol optical properties from both sampling streams. Below the clouds, the single-scattering albedo measured inside the Oklahoma City plume was generally smaller than that observed outside of the plume. Within the cloud layer, but far from the clouds, there is little difference in the aerosol scattering measured inside and outside of the plume. These observations indicate that the vertical transport by the shallow clouds is very localized. Both aerosol extensive and intensive properties are discussed. For example, the total aerosol scattering and the mass-scattering efficiency measured inside the clouds was slightly larger for clouds that have roots within the Oklahoma City plume. Using data from the AMS in conjunction with the CVI inlet reveals that these in-cloud aerosols also have a relatively large amount of nitrate. Possible explanations for this increase nitrate will be discussed.
The boiling point of stratospheric aerosols.
NASA Technical Reports Server (NTRS)
Rosen, J. M.
A photoelectric particle counter was used for the measurement of aerosol boiling points. The operational principle involves raising the temperature of the aerosol by vigorously heating a portion of the intake tube. At or above the boiling point, the particles disintegrate rather quickly, and a noticeable effect on the size distribution and concentration is observed. Stratospheric aerosols appear to have the same volatility as a solution of 75% sulfuric acid. Chemical analysis of the aerosols indicates that there are other substances present, but that the sulfate radical is apparently the major constituent.
Multi-Sensor Aerosol Products Sampling System
NASA Technical Reports Server (NTRS)
Petrenko, M.; Ichoku, C.; Leptoukh, G.
Global and local properties of atmospheric aerosols have been extensively observed and measured using both spaceborne and ground-based instruments, especially during the last decade. Unique properties retrieved by the different instruments contribute to an unprecedented availability of the most complete set of complimentary aerosol measurements ever acquired. However, some of these measurements remain underutilized, largely due to the complexities involved in analyzing them synergistically. To characterize the inconsistencies and bridge the gap that exists between the sensors, we have established a Multi-sensor Aerosol Products Sampling System (MAPSS), which consistently samples and generates the spatial statistics (mean, standard deviation, direction and rate of spatial variation, and spatial correlation coefficient) of aerosol products from multiple spacebome sensors, including MODIS (on Terra and Aqua), MISR, OMI, POLDER, CALIOP, and SeaWiFS. Samples of satellite aerosol products are extracted over Aerosol Robotic Network (AERONET) locations as well as over other locations of interest such as those with available ground-based aerosol observations. In this way, MAPSS enables a direct cross-characterization and data integration between Level-2 aerosol observations from multiple sensors. In addition, the available well-characterized co-located ground-based data provides the basis for the integrated validation of these products. This paper explains the sampling methodology and concepts used in MAPSS, and demonstrates specific examples of using MAPSS for an integrated analysis of multiple aerosol products.
Separating Cloud Forming Nuclei from Interstitial Aerosol
Kulkarni, Gourihar R.
It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice clouds. The data is urgently needed to better represent the aerosol-cloud interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as cloud condensation nuclei (CCN) and ice nuclei (IN), termed as cloud nuclei (CN) henceforth, have become imperative in studying aerosol effects on clouds and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.
Aerosol climate time series from ESA Aerosol_cci (Invited)
NASA Astrophysics Data System (ADS)
Holzer-Popp, T.
Within the ESA Climate Change Initiative (CCI) the Aerosol_cci project (mid 2010 - mid 2013, phase 2 proposed 2014-2016) has conducted intensive work to improve algorithms for the retrieval of aerosol information from European sensors AATSR (3 algorithms), PARASOL, MERIS (3 algorithms), synergetic AATSR/SCIAMACHY, OMI and GOMOS. Whereas OMI and GOMOS were used to derive absorbing aerosol index and stratospheric extinction profiles, respectively, Aerosol Optical Depth (AOD) and Angstrom coefficient were retrieved from the other sensors. Global datasets for 2008 were produced and validated versus independent ground-based data and other satellite data sets (MODIS, MISR). An additional 17-year dataset is currently generated using ATSR-2/AATSR data. During the three years of the project, intensive collaborative efforts were made to improve the retrieval algorithms focusing on the most critical modules. The team agreed on the use of a common definition for the aerosol optical properties. Cloud masking was evaluated, but a rigorous analysis with a pre-scribed cloud mask did not lead to improvement for all algorithms. Better results were obtained using a post-processing step in which sudden transitions, indicative of possible occurrence of cloud contamination, were removed. Surface parameterization, which is most critical for the nadir only algorithms (MERIS and synergetic AATSR / SCIAMACHY) was studied to a limited extent. The retrieval results for AOD, ┼ngstr÷m exponent (AE) and uncertainties were evaluated by comparison with data from AERONET (and a limited amount of MAN) sun photometer and with satellite data available from MODIS and MISR. Both level2 and level3 (gridded daily) datasets were validated. Several validation metrics were used (standard statistical quantities such as bias, rmse, Pearson correlation, linear regression, as well as scoring approaches to quantitatively evaluate the spatial and temporal correlations against AERONET), and in some cases developed further, to evaluate the datasets and their regional and seasonal merits. The validation showed that most datasets have improved significantly and in particular PARASOL (ocean only) provides excellent results. The metrics for AATSR (land and ocean) datasets are similar to those of MODIS and MISR, with AATSR better in some land regions and less good in some others (ocean). However, AATSR coverage is smaller than that of MODIS due to swath width. The MERIS dataset provides better coverage than AATSR but has lower quality (especially over land) than the other datasets. Also the synergetic AATSR/SCIAMACHY dataset has lower quality. The evaluation of the pixel uncertainties shows first good results but also reveals that more work needs to be done to provide comprehensive information for data assimilation. Users (MACC/ECMWF, AEROCOM) confirmed the relevance of this additional information and encouraged Aerosol_cci to release the current uncertainties. The paper will summarize and discuss the results of three year work in Aerosol_cci, extract the lessons learned and conclude with an outlook to the work proposed for the next three years. In this second phase a cyclic effort of algorithm evolution, dataset generation, validation and assessment will be applied to produce and further improve complete time series from all sensors under investigation, new sensors will be added (e.g. IASI), and preparation for the Sentinel missions will be made.
SAGE II aerosol data validation based on retrieved aerosol model size distribution from SAGE II aerosol measurements.
Wang, P H; McCormick, M P; McMaster, L R; Chu, W P; Swissler, T J; Osborn, M T; Russell, P B; Oberbeck, V R; Livingston, J; Rosen, J M; Hofmann, D J; Grams, G W; Fuller, W H; Yue, G K
This paper describes an investigation of the comprehensive aerosol correlative measurement experiments conducted between November 1984 and July 1986 for satellite measurement program of the Stratospheric Aerosol and Gas Experiment (SAGE II). The correlative sensors involved in the experiments consist of the NASA Ames Research Center impactor/laser probe, the University of Wyoming dustsonde, and the NASA Langley Research Center airborne 14-inch (36 cm) lidar system. The approach of the analysis is to compare the primary aerosol quantities measured by the ground-based instruments with the calculated ones based on the aerosol size distributions retrieved from the SAGE II aerosol extinction measurements. The analysis shows that the aerosol size distributions derived from the SAGE II observations agree qualitatively with the in situ measurements made by the impactor/laser probe. The SAGE II-derived vertical distributions of the ratio N0.15/N0.25 (where Nr is the cumulative aerosol concentration for particle radii greater than r, in micrometers) and the aerosol backscatter profiles at 0.532- and 0.6943-micrometer lidar wavelengths are shown to agree with the dustsonde and the 14-inch (36-cm) lidar observations, with the differences being within the respective uncertainties of the SAGE II and the other instruments. PMID:11539801
Aerosol Blanket Likely Thinned During 1990s
NASA Technical Reports Server (NTRS)
Each day, a blanket of tiny particles drifting through the Earth's atmosphere filters out some of the sunlight headed for the planet's surface. These aerosols, including dust, smoke, and human-produced pollution, can reflect incoming light or absorb it, directly affecting the Earth's energy balance and climate. Aerosols also influence the climate indirectly, by affecting the brightness and amount of clouds. Research by NASA scientists on global aerosol patterns since the 1990s indicate the global aerosol blanket has likely thinned, allowing more sunlight to reach the Earth's surface over the past decade. The thinning of the blanket is shown by this trio of images based on satellite observations of aerosol optical thickness, a measurement that scientists use to describe how much the aerosols filter the incoming sunlight. Higher optical thickness (orange and red) means more sunlight blocking. The globes show average aerosol optical thickness for 1988-1991 (top), 2002-2005 (middle), and the change between the two time periods (bottom). Overall, the 1988-1991 image appears redder, a sign that aerosols were blocking more incoming sunlight; the 2002-2005 image has more light yellow areas. In the bottom image, small pockets of red (increased aerosol optical thickness), mostly near land masses in the Northern Hemisphere, are far outnumbered by blue areas (decreased aerosol optical thickness). Because they block incoming sunlight from reaching Earth's surface, aerosols may counterbalance greenhouse gas warming. The decline in the dimming power of aerosols over the past decade may have made the greenhouse warming trend more evident in the past decade than in previous decades. The scientists describe their results as a 'likely' trend because the National Oceanic and Atmospheric Administration satellite sensors they used in their analysis were not specifically designed to observe aerosols, and may contain some errors. However, specific, major aerosol events, such as large volcanic eruptions, show up in the right place at the right time in the observations, and the data also agree with available ground-based observations. Ongoing NASA missions such as the Terra, Aqua, Aura, and Cloudsat/CALIPSO, as well as upcoming missions such as Glory, will provide the data scientists need to monitor aerosol trends over time. NASA image created by Jesse Allen, using data provided courtesy of Michael Mischenko and Igor Geogdzhayev, NASA Goddard Institute of Space Studies.
Global aerosol effects on convective clouds
NASA Astrophysics Data System (ADS)
Wagner, Till; Stier, Philip
Atmospheric aerosols affect cloud properties, and thereby the radiation balance of the planet and the water cycle. The influence of aerosols on clouds is dominated by increase of cloud droplet and ice crystal numbers (CDNC/ICNC) due to enhanced aerosols acting as cloud condensation and ice nuclei. In deep convective clouds this increase in CDNC/ICNC is hypothesised to increase precipitation because of cloud invigoration through enhanced freezing and associated increased latent heat release caused by delayed warm rain formation. Satellite studies robustly show an increase of cloud top height (CTH) and precipitation with increasing aerosol optical depth (AOD, as proxy for aerosol amount). To represent aerosol effects and study their influence on convective clouds in the global climate aerosol model ECHAM-HAM, we substitute the standard convection parameterisation, which uses one mean convective cloud for each grid column, with the convective cloud field model (CCFM), which simulates a spectrum of convective clouds, each with distinct values of radius, mixing ratios, vertical velocity, height and en/detrainment. Aerosol activation and droplet nucleation in convective updrafts at cloud base is the primary driver for microphysical aerosol effects. To produce realistic estimates for vertical velocity at cloud base we use an entraining dry parcel sub cloud model which is triggered by perturbations of sensible and latent heat at the surface. Aerosol activation at cloud base is modelled with a mechanistic, K÷hler theory based, scheme, which couples the aerosols to the convective microphysics. Comparison of relationships between CTH and AOD, and precipitation and AOD produced by this novel model and satellite based estimates show general agreement. Through model experiments and analysis of the model cloud processes we are able to investigate the main drivers for the relationship between CTH / precipitation and AOD.
Characterization of aerosols produced by surgical procedures
Yeh, H.C.; Muggenburg, B.A.; Lundgren, D.L.; Guilmette, R.A.; Snipes, M.B.; Jones, R.K. [Inhalation Toxicology Research Institute, Albuquerque, NM (United States); Turner, R.S. [Lovelace Health Systems, Albuquerque, NM (United States)
In many surgeries, especially orthopedic procedures, power tools such as saws and drills are used. These tools may produce aerosolized blood and other biological material from bone and soft tissues. Surgical lasers and electrocautery tools can also produce aerosols when tissues are vaporized and condensed. Studies have been reported in the literature concerning production of aerosols during surgery, and some of these aerosols may contain infectious material. Garden et al. (1988) reported the presence of papilloma virus DNA in the fumes produced from laser surgery, but the infectivity of the aerosol was not assessed. Moon and Nininger (1989) measured the size distribution and production rate of emissions from laser surgery and found that particles were generally less than 0.5 {mu}m diameter. More recently there has been concern expressed over the production of aerosolized blood during surgical procedures that require power tools. In an in vitro study, the production of an aerosol containing the human immunodeficiency virus (HIV) was reported when power tools were used to cut tissues with blood infected with HIV. Another study measured the size distribution of blood aerosols produced by surgical power tools and found blood-containing particles in a number of size ranges. Health care workers are anxious and concerned about whether surgically produced aerosols are inspirable and can contain viable pathogens such as HIV. Other pathogens such as hepatitis B virus (HBV) are also of concern. The Occupational Safety and Health funded a project at the National Institute for Inhalation Toxicology Research Institute to assess the extent of aerosolization of blood and other tissues during surgical procedures. This document reports details of the experimental and sampling approach, methods, analyses, and results on potential production of blood-associated aerosols from surgical procedures in the laboratory and in the hospital surgical suite.
Determining the Mixing State of Organic Aerosol Components using High-Resolution Aerosol Mass Spectrometry
NASA Astrophysics Data System (ADS)
Hildebrandt, L.; Henry, K.; Kroll, J. H.; Worsnop, D. R.; Pandis, S. N.; Donahue, N. M.
According to the pseudo-ideal mixing assumption employed in practically all chemical transport models, organic aerosol components from different sources interact with each other in a single solution, independent of the organic aerosol composition. This is a critical assumption which greatly affects modeled organic aerosol concentrations in the troposphere, but it has not been confirmed experimentally. A main experimental challenge is that organic aerosols from different sources look very similar when analyzed with an aerosol mass spectrometer, especially if the aerosols have undergone reactions after their initial formation. We developed a new experimental method to overcome this challenge, using isotopically labeled compounds (13C or D) and a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS) from Aerodyne, Inc. We generated isotopically labeled secondary organic aerosol (SOA) from toluene in the presence of unlabeled SOA from ?-pinene, and vice versa. Using the HR-AMS data, we identified isotopically labeled and unlabeled organic fragments based on their exact mass and subsequently separated anthropogenic (labeled) and biogenic (unlabeled) SOA using a chemical mass balance. We evaluated the mixing of the different organic-aerosol types by comparing their aerosol mass yields when formed in these mixtures to their yields when formed in isolation. Our results are consistent with pseudo-ideal mixing of anthropogenic and biogenic SOA components. This powerful new experimental method can also be used to evaluate the pseudo-ideal mixing assumption of primary and secondary organic aerosol components.
Fluorescent lifetime imaging of atmospheric aerosols: a direct probe of aerosol viscosity.
Hosny, Neveen A; Fitzgerald, Clare; Tong, Changlun; Kalberer, Markus; Kuimova, Marina K; Pope, Francis D
The viscosity of atmospheric aerosol particles affects a number of key physical and chemical particle properties, such as composition and reactivity. However, determination of the microscopic viscosity of aerosol particles is a non-trivial task. We report a new method of imaging viscosity in a variety of model aerosol systems, based on a fluorescence lifetime determination of viscosity-sensitive fluorophores termed molecular rotors. We report the viscosity changes associated with the relative humidity dependent hygroscopicity of NaCI and sucrose aerosols, as well as reaction dependent changes in viscosity during ozonolysis of oleic acid aerosols. The Fluorescence Lifetime Imaging Microscopy (FLIM) of molecular rotors shows great promise in understanding important fundamental aerosol properties, which can be both time-dependent and spatially variable through the aerosol particle. PMID:24601010
Thermal Infrared Radiative Forcing By Atmospheric Aerosol
NASA Astrophysics Data System (ADS)
Adhikari, Narayan
The work mainly focuses on the study of thermal infrared (IR) properties of atmospheric greenhouse gases and aerosols, and the estimation of the aerosol-induced direct longwave (LW) radiative forcing in the spectral region 5-20 mum at the Earth's surface (BOA; bottom of the atmosphere) and the top of the atmosphere (TOA) in cloud-free atmospheric conditions. These objectives were accomplished by conducting case studies on clear sky, smoky, and dusty conditions that took place in the Great Basin of the USA in 2013. Both the solar and thermal IR measurements and a state-of-the-science radiative transfer model, the LBLDIS, a combination of the Line-By-Line Radiative Transfer Model and the Discrete Ordinate Radiative Transfer (DISORT) solver were employed for the study. The LW aerosol forcing is often not included in climate models because the aerosol effect on the LW is often assumed to be negligible. We lack knowledge of aerosol characteristics in the LW region, and aerosol properties exhibit high variability. We have found that the LW TOA radiative forcing due to fine mode aerosols, mainly associated with small biomass burning smoke particles, is + 0.4 W/m2 which seems to be small, but it is similar to the LW radiative forcing due to increase in CO2 concentration in the Earth's atmosphere since the preindustrial era of 1750 (+ 1.6 W/m 2). The LW radiative forcing due to coarse mode aerosols, associated with large airborne mineral dust particles, was found to be as much as + 5.02 W/m2 at the surface and + 1.71 W/m2 at the TOA. All of these significant positive values of the aerosol radiative forcing both at the BOA and TOA indicate that the aerosols have a heating effect in the LW range, which contributes to counterbalancing the cooling effect associated with the aerosol radiative forcing in the shortwave (SW) spectral region. In the meantime, we have found that LW radiative forcing by aerosols is highly sensitive to particle size and complex refractive indices of the aerosol constituents. We have also demonstrated that LW aerosol radiative forcing is somewhat sensitive to the water vapor content in the atmosphere, and increases with the dryness of the atmosphere. This evidence supports our argument that the Great Basin area of the USA, which usually has extremely dry atmospheric conditions, can be an appropriate place to study the dry-desert aerosol climate forcing in a regional scale. An analysis of aerosol IR backscattering shows that the effect significantly contributes to both the BOA and TOA IR forcings, even if the aerosols do not exhibit absorption at all in the thermal IR. The general LW radiative forcing is, therefore, associated with both the absorption and scattering effects of the aerosols. Neglecting LW scattering will result in an underestimation of LW radiative forcing by aerosols. Finally, the discrepancy between the FTIR-observed and modeled radiance with aerosols indicates a significant uncertainty, which demands further research on the LW optical properties of fine and coarse mode aerosol.
Global Aerosol Optical Models and Lookup Tables for the New MODIS Aerosol Retrieval over Land
NASA Technical Reports Server (NTRS)
Levy, Robert C.; Remer, Loraine A.; Dubovik, Oleg
Since 2000, MODIS has been deriving aerosol properties over land from MODIS observed spectral reflectance, by matching the observed reflectance with that simulated for selected aerosol optical models, aerosol loadings, wavelengths and geometrical conditions (that are contained in a lookup table or 'LUT'). Validation exercises have showed that MODIS tends to under-predict aerosol optical depth (tau) in cases of large tau (tau greater than 1.0), signaling errors in the assumed aerosol optical properties. Using the climatology of almucantur retrievals from the hundreds of global AERONET sunphotometer sites, we found that three spherical-derived models (describing fine-sized dominated aerosol), and one spheroid-derived model (describing coarse-sized dominated aerosol, presumably dust) generally described the range of observed global aerosol properties. The fine dominated models were separated mainly by their single scattering albedo (omega(sub 0)), ranging from non-absorbing aerosol (omega(sub 0) approx. 0.95) in developed urban/industrial regions, to neutrally absorbing aerosol (omega(sub 0) approx.90) in forest fire burning and developing industrial regions, to absorbing aerosol (omega(sub 0) approx. 0.85) in regions of savanna/grassland burning. We determined the dominant model type in each region and season, to create a 1 deg. x 1 deg. grid of assumed aerosol type. We used vector radiative transfer code to create a new LUT, simulating the four aerosol models, in four MODIS channels. Independent AERONET observations of spectral tau agree with the new models, indicating that the new models are suitable for use by the MODIS aerosol retrieval.
Modulation of aerosol clouds produced by pressurised inhalation aerosols.
Brambilla, G; Ganderton, D; Garzia, R; Lewis, D; Meakin, B; Ventura, P
The inclusion of non-volatile components such as glycerol or polyethylene glycol in hydrofluoralkane (HFA) solution formulations for pressurised metered dose inhalers (pMDIs), greatly increases the particle size of the aerosol. Cloud characteristics can be further modulated by permuting this factor with the choice of propellant and the dimensions of the actuator, to give a chosen fine particle dose and particle diameter. This principle has been used to design solutions which closely match the performance of chlorofluorocarbon based suspension formulations containing beclomethasone dipropionate, budesonide and ipratropium bromide as assessed for pharmaceutical equivalence using the Andersen Cascade impactor. PMID:10469923
Waterspout - an Atmospheric Aerosol Dusty Plasma
Rantsev-Kartinov, V.A. [INF RRC 'Kurchatov Institute', Moscow, 123182 (Russian Federation)
An aerosol -- capillary electrostatic model of a waterspout is submitted. The waterspout is treated as a long-living filament of aerosol plasma, which is formed at electric breakdown of interval between a charged cloud and a vertically floating cylinder, which is individual block of ocean's skeletal structures of revealed recently by author.
The pulsed optoacoustic effect in aerosols
V. P. Zharov; A. E. Negin; Ia. O. Simanovskii
The optoacoustic effect in water aerosols upon exposure to pulsed CO2 laser radiation is studied. Saturation of the optoacoustic signal was observed at a laser radiation energy density greater than 5 J\\/sq cm. This effect is due to variation in the dispersed composition of the aerosol during the duration of the laser pulse.
NONLINEAR OPTICS: Pulsed optoacoustic effect in aerosols
V. P. Zharov; A. E. Negin; Ya O. Simanovskii
An experimental investigation was made of the optoacoustic effect in water aerosols interacting with CO2 laser pulses. Saturation of the optoacoustic signal was observed when the energy density exceeded 5 J\\/cm2. This was attributed to a change in the particle size distribution of the aerosol during a laser pulse. Bibtex entry for this abstract Preferred format for this abstract (see
Recent work has shown that particle-phase reactions contribute to the formation of secondary organic aerosol (SOA), with enhancements of SOA yields in the presence of acidic seed aerosol. In this study, the chemical composition of SOA from the photooxidations of a-pinene and isop...
6, 1135711389, 2006 SAGE III aerosol
Paris-Sud XI, Universitķ de
ACPD 6, 11357Ł11389, 2006 SAGE III aerosol extinction validation L. W. Thomason et al. Title Page Chemistry and Physics Discussions SAGE III aerosol extinction validation in the Arctic winter: comparisons with SAGE II and POAM III L. W. Thomason 1 , L. R. Poole 1 , and C. E. Randall 3 1 NASA Langley Research
Agglomeration characteristics of fast reactor HCDA aerosols
G. W. Parker; G. E. Creek; A. L. Jr. Sutton
The behavior of vaporized mixed oxide fuel aerosols postulated to result from fast reactor core disruptive accidents is a subject which is intensely evaluated in fast reactor safety analysis, containment design, and site selection licensing procedure. In this program, surrogate uranium oxide aerosols produced by vapor condensation of super-heated liquid UOŌ have been produced in a variety of ways and
The report reviews techniques of metal aerosol generation for the purpose of establishing the state-of-the-art of the technology and guiding future researchers. Exposure to metal or metallic compound submicron aerosols is widespread in both industrial and general environments. Re...
Quantifying Ice Nucleation by Silver Iodide Aerosols
Paul Judson Demott
Laboratory studies of artificial ice nucleating aerosols used for weather modification by cloud seeding have generally been inadequate for describing their complex action in the varied temperature, pressure humidity, and cloud conditions that can be encountered in the atmosphere. This study provides a quantitative framework for predicting ice formation by aerosol particles based on experiments which specifically target currently accepted
A carbonaceous aerosol generator designed for inhalation experiments with animals is described. The aerosol produced from a modified diffusion flame has a concentration of 3-10 mg/cu. m. at a flow rate of 30 L/min. The addition of a small amount of O2 to the acetylene fuel greatl...
Aerosol Chemistry of Furfural and Sugars
T. Srithawirat; P. Brimblecombe
Furfural and sugars (as levoglucosan equivalent) are derived from biomass burning and contribute to aerosol composition. This study examined the potential of furfural and levoglucosan to be tracers of biomass burning. Furfural is likely to be oxidized quickly so comparison with levoglucosan may give a sense of the age of the aerosols in forest fire smoke. However, few furfural emissions
AO13 Aerosol sampling April 29, 2008
Oxford, University of
direct sampling of aerosol particles at altitude, and published studies have involved aircraft mounted concentrations to be inferred. 1 Introduction Aerosol research is a very active field, with particular bearing], and Pusechel at al [3], employed NASA ER-2 and DC-8 research aircraft mounted sampling devices. These aircraft
ENCAPSULATION EFFECTS ON CARBONACEOUS AEROSOL LIGHT ABSORPTION Arthur Sedlacek, Brookhaven National of aerosol absorption on direct radiative forcing is still an active area of research, in part, because. This poster presents data on black carbon (BC) light absorption measured by Photothermal Interferometry
An atmospheric sampling program was carried out in the greater Phoenix, Arizona metropolitan area in November, 1975. Objectives of the study were to measure aerosol mass flux through Phoenix and to characterize the aerosol according to particle type and size. The ultimate goal of...
Charge distributions and coagulation of radioactive aerosols
C. F. Clement; R. A. Clement; R. G. Harrison
The self-charging of radioactive aerosols will be reduced by background ions, such as those produced by radioactive gases. The sources of these background ions and their production rates are specified for a reactor containment atmosphere during a possible nuclear accident. Previous theory is extended to calculate the charging of a polydisperse radioactive aerosol. Gaussian approximations to charge distributions on an
Aerosol feed direct methanol fuel cell
NASA Technical Reports Server (NTRS)
Kindler, Andrew (Inventor); Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)
Improvements to fuel cells include introduction of the fuel as an aerosol of liquid fuel droplets suspended in a gas. The particle size of the liquid fuel droplets may be controlled for optimal fuel cell performance by selection of different aerosol generators or by separating droplets based upon size using a particle size conditioner.
Beijing aerosol: Atmospheric interactions and new trends
Benjamin Guinot; HķlĶne Cachier; Jean Sciare; Yu Tong; Wang Xin; Yu Jianhua
Beijing aerosols are scrutinized as a case study for atmospheric interactions in a complex multisource situation. For the first time, fine (2 ?m) aerosols were continuously collected during a time period (20 months) long enough to capture seasonal trends of sources and interactions. Weekly samples were obtained from January 2003 to August 2004 downtown and during 9 months at two
Spectral absorption properties of atmospheric aerosols
R. W. Bergstrom; P. Pilewskie; P. B. Russell; J. Redemann; T. C. Bond; P. K. Quinn; B. Sierau
We have determined the solar spectral absorption optical depth of atmospheric aerosols for specific case studies during several field programs (three cases have been reported previously; two are new results). We combined airborne measurements of the solar net radiant flux density and the aerosol optical depth with a detailed radiative transfer model for all but one of the cases. The
A continuous flow system for exposing plants to submicron aerosols of sulfuric acid has been developed and an operational model has been constructed. Exposure chambers have been designed to allow simultaneous exposures of the same plant to aerosol and control environments. All su...
Reduction of 85Sr, 137Cs, 131I and 141Ce retention in rats by simultaneous oral administration of calcium alginate, ferrihexacyanoferrate(II), KI and Zn-DTPA
Kargacin, B.; Kostial, K.
The effect of simultaneous oral administration of a mixture of calcium alginate, ferrihexacyanoferrate(II) and KI and of the chelating agent zinc diethylenetriaminepentaacetate (Zn-DTPA) on the retention of radioactive Sr, Cs, I and Ce was investigated in 7-week-old female rats. The respective antidotes were administered in food during the first three days of the experiment and the radionuclides were administered on the second day of the experiment. The radionuclide retention was determined in the whole body, carcass, gut, liver, kidneys and respective critical organs six days after oral administration of 85Sr, 137Cs, 131I and intraperitoneal administration of 141Ce and one day after oral administration of 141Ce. Simultaneous oral administration of the four therapeutic agents reduced the retention of radioactive Sr, Cs and I administered orally and Ce applied intraperitoneally. Zn-DTPA did not diminish efficacy of antidotes from the mixture nor did the mixture significantly alter the effect of Zn-DTPA. Simultaneous oral administration of calcium alginate, ferrihexacyanoferrate(II), KI and Zn-DTPA might present a convenient method for delayed therapy especially in cases of prolonged increased environmental exposure to several radionuclides.
DTPA (Diethylenetriamine pentaacetate)
... Radiation Emergencies More Information Information for Professionals Public Health Preparedness Capabilities Toolkits Resource Library Population Monitoring Patient Management Countermeasures Communications Mass Fatalities Mass Care Laboratory Law ...
Global Analysis of Aerosol Properties Above Clouds
NASA Technical Reports Server (NTRS)
Waquet, F.; Peers, F.; Ducos, F.; Goloub, P.; Platnick, S. E.; Riedi, J.; Tanre, D.; Thieuleux, F.
The seasonal and spatial varability of Aerosol Above Cloud (AAC) properties are derived from passive satellite data for the year 2008. A significant amount of aerosols are transported above liquid water clouds on the global scale. For particles in the fine mode (i.e., radius smaller than 0.3 m), including both clear sky and AAC retrievals increases the global mean aerosol optical thickness by 25(+/- 6%). The two main regions with man-made AAC are the tropical Southeast Atlantic, for biomass burning aerosols, and the North Pacific, mainly for pollutants. Man-made AAC are also detected over the Arctic during the spring. Mineral dust particles are detected above clouds within the so-called dust belt region (5-40 N). AAC may cause a warming effect and bias the retrieval of the cloud properties. This study will then help to better quantify the impacts of aerosols on clouds and climate.
Beijing Olympics as an aerosol field experiment
NASA Astrophysics Data System (ADS)
Cermak, J.; Knutti, R.
During the 2008 Olympic Summer Games, emission reductions were enforced in Beijing to improve air quality. Here we explore their effect on the regional aerosol load. We compare satellite-retrieved aerosol optical thickness (AOT) of that period with previous years, both in absolute terms and in a neural network approach taking into account the meteorological conditions. A statistically significant reduction of aerosol load is found in Beijing that decreases in magnitude and significance with increasing region size. Locally, the aerosol load (log(AOT)) was about 0.4 to 0.75 standard deviations below the levels expected for the prevailing meteorological situation. The small size of this effect relative to meteorological variability highlights the importance of regional aerosol transport.
Radiative forcing under mixed aerosol conditions
NASA Astrophysics Data System (ADS)
GarcĒA, O. E.; Exp¾sito, F. J.; DĒAz, J. P.; DĒAz, A. M.
The mixture of mineral dust with biomass burning or urban-industrial aerosols presents significant differences in optical properties when compared to those of the individual constituents, leading to different impacts on solar radiation levels. This effect is assessed by estimating the direct radiative forcing (?F) of these aerosols from solar flux models using the radiative parameters derived from the Aerosol Robotic Network (AERONET). These data reveal that, in oceanic and vegetative covers (surface albedo (SA) < 0.30), the aerosol effect at the top of atmosphere (TOA) is always cooling the Earth-atmosphere system, regardless of the aerosol type. The obtained average values of ?F range between -27 ▒ 15 Wm-2 (aerosol optical depth (AOD) at 0.55 ?m, 0.3 ▒ 0.3) for mineral dust mixed with urban-industrial aerosols, registered in the East Asia region, and -34 ▒ 18 Wm-2 (AOD = 0.8 ▒ 0.4) for the mixture of the mineral dust and biomass burning particles, observed in the Central Africa region. In the intermediate SA range (0.30-0.50) the TOA radiative effect depends on the aerosol absorption properties. Thus, aerosols with single scattering albedo at 0.55 ?m lower than ś0.88 lead to a warming of the system, with ?F of 10 ▒ 11 Wm-2 for the mixture of mineral dust and biomass burning. Cases with SA > 0.30 are not present in East Asia region. At the bottom of atmosphere (BOA) the maximum ?F values are associated with the highest AOD levels obtained for the mixture of mineral dust and biomass burning aerosols (-130 ▒ 44 Wm-2 with AOD = 0.8 ▒ 0.4 for SA < 0.30).
Optical Properties of Atmospheric Aerosol in Maritime Environments
Alexander Smirnov; Brent N. Holben; Yoram J. Kaufman; Oleg Dubovik; Thomas F. Eck; Ilya Slutsker; Christophe Pietras; Rangasayi N. Halthore
Systematic characterization of aerosol over the oceans is needed to understand the aerosol effect on climate and on transport of pollutants between continents. Reported are the results of a comprehensive optical and physical characterization of ambient aerosol in five key island locations of the Aerosol Robotic Network (AERONET) of sun and sky radiometers, spanning over 2-5 yr. The results are
Characteristics of aerosol types from AERONET sunphotometer measurements
J. Lee; J. Kim; C. H. Song; S. B. Kim; Y. Chun; B. J. Sohn; B. N. Holben
By using observations from the Aerosol Robotic Network (AERONET), aerosol types are classified according to dominant size mode and radiation absorptivity as determined by fine-mode fraction (FMF) and single-scattering albedo (SSA), respectively. The aerosol type from anthropogenic sources is significantly different with regard to location and season, while dust aerosol is observed persistently over North Africa and the Arabian Peninsula.
Direct Measurement of Aerosol Absorption Using Photothermal Interferometry
A. J. Sedlacek; J. A. Lee
Efforts to bound the contribution of light absorption in aerosol radiative forcing is still very much an active area of research in large part because aerosol extinction is dominated by light scattering. In response to this and other technical issues, the aerosol community has actively pursued the development of new instruments to measure aerosol absorption (e.g., photoacoustic spectroscopy (PAS) and
Marine aerosols. (Latest citations from Oceanic abstracts). Published Search
Not Available
The bibliography contains citations concerning the optical, chemical and physical properties of marine aerosols. The citations examine seasonal variations in aerosol composition, analysis of chemical pollutants contained in the aerosols, and identification of the sources of these pollutants. Attention is also given to mathematical modeling and computerized simulation of marine aerosols. (Contains 250 citations and includes a subject term index and title list.)
Calculating Capstone Depleted Uranium Aerosol Concentrations from Beta Activity Measurements
Frances Szrom; Gerald A. Falo; MaryAnn Parkhurst; Jeffrey J. Whicker; David P. Alberth
Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the depleted uranium (DU) source term for the subsequent human health risk assessment (HHRA) of Capstone aerosols.
Aerosol characterization and measurement techniques towards SFR safety studies
R. Baskaran; V. Subramanian; J. Misra; R. Indira; P. Chellapandi; Baldev Raj
An Aerosol Test Facility (ATF) has been designed, fabricated and commissioned at Radiological Safety Division, Safety Group, Indira Gandhi Centre for Atomic Research, INDIA, to carry out safety studies related to aerosols in Sodium cooled Fast Reactor (SFR). The sources of aerosol generation during normal operation of SFR and accidental scenario have been discussed. Aerosol sampling issues to get the
Global observations of desert dust and biomass burning aerosols
Graaf, Martin de
Global observations of desert dust and biomass burning aerosols Martin de Graaf KNMI #12; Outline Ę Absorbing Aerosol Index - Theory Ę Absorbing Aerosol Index - Reality Ę Biomass burning.6 Biomass burning over Angola, 09 Sep. 2004 Absorbing Aerosol Index PMD image #12;biomass burning ocean
The Model 3070A Electrical Aerosol Detector (EAD) measures a unique aerosol parameter called total aerosol length. Reported as mm/cm3, aerosol length can be thought of as a number concentration times average diameter, or simply as d1 weighting. This measurement falls between nu...
Analyses of multiple global and regional aerosol products: Investigation of aerosol effects and artifacts
NASA Astrophysics Data System (ADS)
Jeong, Myeong Jae
Multiple aerosol products derived from satellite, ground-based, and air-borne instruments were analyzed with a focus on satellite-based aerosol products. Aerosol measurements based on different techniques were utilized to investigate the effects and the artifacts of aerosols and clouds by taking advantages of respective techniques. The global aerosol products derived from Advanced Very High Resolution Radiometer (AVHRR) and Total Ozone Mapping Spectrometer (TOMS), were analyzed for extracting synergic information. Global distributions of dominant aerosol type(s) were derived and the two products were combined to acquire an extended spatial coverage of aerosol optical thickness (AOT) at a common wavelength (0.55mum). It was shown that the derived AOT agreed reasonably with AOT from the state-of-the-art Moderate Resolution Imaging Spectroradiometer (MODIS). In-depth comparison of aerosol products derived from the MODIS and the AVHRR was performed. New insights and understanding were gained for the discrepancies between the two prominent aerosol products, allowing for bridging the current and past products. Several factors causing the discrepancies were investigated. Cloud-screening techniques and aerosol models employed by the retrieval algorithms were found to be the most important factors explaining the observed discrepancies. The column aerosol humidification effect (AHE) was investigated. The column AHE was shown to be sensitive to changes in relative humidity (RH). Six methods to infer the column AHE were introduced. The knowledge of the AHE helps investigate aerosol properties and retrievals near clouds, enabling separation of aerosol real effects from artifacts associated with clouds. Finally, apparent correlations between AOT and cloud amount from ground- and satellite-based measurements were investigated. Several factors including air convergence, cloud contamination and uncertainty in cloud cover estimation, the AHE, cloud-processed/new particle genesis were studied to explain the correlations. We showed that the correlation found in ground-based measurements is mostly due to real effects while satellite-based measurements are significantly influenced by artifacts caused by clouds.
Simultaneous aerosol measurements of unusual aerosol enhancement in the troposphere over Syowa Station, Antarctica
NASA Astrophysics Data System (ADS)
Hara, K.; Hayashi, M.; Yabuki, M.; Shiobara, M.; Nishita-Hara, C.
Unusual aerosol enhancement is often observed at Syowa Station, Antarctica, during winter and spring. Simultaneous aerosol measurements near the surface and in the upper atmosphere were conducted twice using a ground-based optical particle counter, a balloon-borne optical particle counter, and micropulse lidar (MPL) in August and September 2012. During 13-15 August, aerosol enhancement occurred immediately after a storm condition. A high backscatter ratio and high aerosol concentrations were observed from the surface to ca. 2.5 km over Syowa Station. Clouds appeared occasionally at the top of the aerosol-enhanced layer during the episode. Aerosol enhancement was terminated on 15 August by strong winds from a cyclone's approach. In the second case, on 5-7 September, aerosol number concentrations in Dp > 0.3 ?m near the surface reached > 104 L-1 at about 15:00 UT (Universal Time) on 5 September despite calm wind conditions, whereas MPL measurement exhibited aerosols were enhanced at about 04:00 UT at 1000-1500 m above Syowa Station. The aerosol enhancement occurred near the surface to ca. 4 km. In both cases, air masses with high aerosol enhancement below 2.5-3 km were transported mostly from the boundary layer over the sea-ice area. In addition, air masses at 3-4 km in the second case came from the boundary layer over the open-sea area. This air mass history strongly suggests that dispersion of sea-salt particles from the sea-ice surface contributes considerably to aerosol enhancement in the lower free troposphere (about 3 km) and that the release of sea-salt particles from the ocean surface engenders high aerosol concentrations in the free troposphere (3-4 km). Continuous MPL measurements indicate that high aerosol enhancement occurred mostly in surface-lower free troposphere (3 km) during the period July-September.
Chemical Characterization of Water Soluble Organic Aerosol during SOAS Using High Resolution Aerosol Mass Spectrometer
NASA Astrophysics Data System (ADS)
Xu, L.; Guo, H.; King, L.; Cerully, K. M.; Bougiatioti, A.; Nenes, A.; Weber, R.; Ng, N.
Secondary organic aerosols (SOA) have important impacts on climate, visibility, and human health. Atmospheric aqueous-phase chemistry is a substantial source of SOA, but this process is poorly understood. During Southern Oxidant and Aerosol Study (SOAS), various properties of water-soluble organic aerosols were investigated by a novel system. In this system, a Particle-Into-Liquid-Sampler (PILS), High-Resolution Time-of-Flight Mass Spectrometer (HR-ToF-AMS), Cloud Condensation Nuclei Spectrometer (CCN), and Thermal Denuder were coupled to continuously measure the chemical composition, CCN properties, and volatilities of water-soluble organic aerosols. This presentation will focus on chemical composition of water-soluble organic aerosol measured by the HR-ToF-AMS. During the six week campaign, HR-ToF-AMS was set up to automatically switch sample flow between ambient or PILS-nebulizer sample line every 30min. Our measurements show that the majority of organic aerosols were water soluble. The mass spectra of water-soluble organic aerosol had a more prominent peak at m/z 29 (CHO+), which is a characteristic peak associated with glyoxal SOA formed in chamber experiments. Positive Matrix Factorization (PMF) was performed on water-soluble organic aerosol data and in addition to the oxygenated organic aerosols (OOA), it also resolved a factor with a distinctive peak at m/z 29, which may be a factor indicative of aqueous-phase glyoxal SOA. Further, elemental analyses are being carried out to determine the oxygen/ carbon (O/C) and hydrogen/carbon (H/C) ratios of water-soluble organic aerosols, which are indications of the degree of oxidation of aerosols. Detailed comparisons between total organic aerosol and water-soluble organic aerosol will be discussed to reveal the interactions between anthropogenic and biogenic emissions on SOA formation.
Optimal Aerosol Parameterization for Remote Sensing Retrievals
NASA Technical Reports Server (NTRS)
Newchurch, Michael J.
We have developed a new algorithm for the retrieval of aerosol and gases from SAGE It1 solar transmission measurements. This algorithm improves upon the NASA operational algorithm in several key aspects, including solving the problem non-linearly and incorporating a new methodology for separating the contribution of aerosols and gases. In order to extract aerosol information we have built a huge database of aerosol models for both stratospheric and tropospheric aerosols, and polar stratospheric cloud particles. This set of models allows us to calculate a vast range of possible extinction spectra for aerosols. and from these, derive a set of eigenvectors which then provide the basis set used in our inversion algorithm. Our aerosol algorithm and retrievals are described in several articles (listed in References Section) published under this grant. In particular they allow us to analyze the spectral properties of aerosols and PSCs and ultimately derive their microphysical properties. We have found some considerable differences between our spectra and the ones derived from the SAGE III operational algorithm. These are interesting as they provide an independent check on the validity of published aerosol data and, in particular, on their associated uncertainties. In order to understand these differences, we are assembling independent aerosol data from other sources with which to make comparisons. We have carried out extensive comparisons of our ozone retrievals with both SAGE III and independent lidar, ozonesonde, and satellite measurements (Polyakov et al., 2004). These show very good agreement throughout the stratosphere and help to quantify differences which can be attributed to natural variation in ozone versus that produced by algorithmic differences. In the mid - upper stratosphere, agreement with independent data was generally within 5 - 20%. but in the lower stratosphere the differences were considerably larger. We believe that a large proportion of this discrepancy in the lower stratosphere is attributable to natural variation, and is also seen in comparisons between lidar and ozonesonde measurements. NO2 profiles obtained with our algorithm were compared to those obtained through the SAGE III operational algorithm and exhibited differences of 20 - 40%. Our retrieved profiles agree with the HALOE NO2 measurements significantly better than those of the operational retrieval. In other work (described below), we are extending our aerosol retrievals into the infrared regime and plan to perform retrievals from combined uv-visible-infrared spectra. This work will allow us to use the spectra to derive the size and composition of aerosols, and we plan to employ our algorithms in the analysis of PSC spectra. We are presently also developing a limb-scattering algorithm to retrieve aerosol data from limb measurements of solar scattered radiation.
A pathway analysis of global aerosol processes
NASA Astrophysics Data System (ADS)
Schutgens, Nick; Stier, Philip
Although budgets for aerosol emission and deposition (macrophysical fluxes) have been studied before, much less is known about the budgets of processes e.g. nucleation, coagulation and condensation. A better understanding of their relative importance would improve our understanding of the aerosol system and help model development and evaluation. Aerosols are not only emitted from and deposited to the Earth's surface but are modified during their transport. The processes for these modifications include nucleation of H2SO4 gas into new aerosol, coagulation with other aerosol and condensation of H2SO4 unto existing aerosol. As a result of these processes, aerosol grow in size and change their chemical composition, often becoming hydrophilic where they were hydrophobic before. This affects their characteristics for various deposition processes (sedimentation, dry or wet deposition) as well as their radiative properties and hence climate forcing by aerosol. We present a complete budget of all aerosol processes in the aerosol-climate model ECHAM-HAM including the M7 microphysics. This model treats aerosol as 7 distinct but interacting two-moment modes of mixed species (soot, organic carbons, sulfate, sea salt and dust). We will show both global budgets as well as regional variations in dominant processes. Some of our conclusions are: condensation of H2SO4 gas onto pre-existing particles is an important process, dominating the growth of small particles in the nucleation mode to the Aitken mode and the ageing of hydrophobic matter. Together with in-cloud production of H2SO4, it significantly contributes to (and often dominates) the mass burden (and hence composition) of the hydrophilic Aitken and accumulation mode particles. Particle growth itself is the leading source of number densities in the hydrophilic Aitken and accumulation modes, with their hydrophobic counterparts contributing (even locally) relatively little. However, the coarse mode is mostly decoupled from the smaller modes. Our analysis also suggests that coagulation serves mainly as a loss process for number densities and that it is a relatively unimportant contributor to composition changes of aerosol. Our results provide an objective way of complexity analysis in a global aerosol model and will be used in future work where we will reduce this complexity in ECHAM-HAM.
Impact of clouds and precipitation on atmospheric aerosol
NASA Astrophysics Data System (ADS)
Andronache, Constantin
Aerosols have a significant impact on the dynamics and microphysics of continental mixed-phase convective clouds. High aerosol concentrations provide enhanced cloud condensation nuclei that can lead to the invigoration of convection and increase of surface rainfall. Such effects are dependent on environmental conditions and aerosol properties. Clouds are not only affected by aerosol, they also alter aerosol properties by various processes. Cloud processing of aerosol includes: convective redistribution, modification in the number and size of aerosol particles, chemical processing, new particle formation around clouds, and aerosol removal by rainfall to the surface. Among these processes, the wet removal during intense rain events, in polluted continental regions, can lead to spikes in acidic deposition into environment. In this study, we address the effects of clouds and precipitation on the aerosol distribution in cases of convective precipitation events in eastern US. We examine the effects of clouds and precipitation on various aerosol species, as well as their temporal and spatial variability.
Correlation between ground-based aerosol optical depth and TOMS aerosol index: a comparison between measurements and MODTRAN simulations
Giulia Pavese; Francesco Esposito; Carmine Serio
A comparison between simulated data and measurements performed by means of a spectroradiometer has been done. We searched a correlation between Aerosol Optical Depth, measured the over a wide spectral range, and TOMS Aerosol Index, which is satellite retrieved. This comparison has been done for both desertic aerosol (measurements taken in Namibia, 1998) and rural aerosol (measurements realized in Southern
Boundary layer aerosol chemistry during TexAQS\\/GoMACCS 2006: Insights into aerosol sources and transformation processes
T. S. Bates; P. K. Quinn; D. Coffman; K. Schulz; J. E. Johnson; E. J. Williams; B. M. Lerner; W. M. Angevine; S. C. Tucker; W. A. Brewer; A. Stohl
The air quality and climate forcing impacts of atmospheric aerosols in a metropolitan region depend on the amount, composition, and size of the aerosol transported into the region; the input and removal of aerosols and aerosol precursors within the region; and the subsequent chemical processing in the atmosphere. These factors were studied in the Houston-Galveston-Gulf of Mexico region, aboard the
Development of mixed-phase clouds from multiple aerosol size distributions and the effect of the clouds on aerosol removal
NASA Astrophysics Data System (ADS)
Jacobson, Mark Z.
This paper provides numerics for cloud and precipitation development from multiple aerosol size distributions and examines the effect of clouds and precipitation on aerosol removal. Numerical techniques are given for (1) simultaneous liquid and ice growth onto multiple aerosol size distributions, (2) diffusiophoretic, thermophoretic, gravitational, etc., coagulation among liquid, ice, and graupel, and their aerosol components, (3) contact freezing (CF) of drops by size-resolved interstitial aerosols, (4) heterogeneous plus homogeneous freezing, (5) liquid drop breakup, (6) coagulation of cloud hydrometeors and incorporated aerosols with interstitial aerosols, (7) coagulation of precipitation hydrometeors with interstitial and below-cloud aerosols (washout), (8) removal of precipitation and incorporated aerosols (rainout), (9) below-cloud evaporation/sublimation to smaller hydrometeors and aerosol cores, (10) gas washout, and (11) aqueous chemistry. Major conclusions are (1) hydrometeor-hydrometeor coagulation appears to play a substantial role in controlling aerosol-particle number globally, (2) washout (aerosol-hydrometeor coagulation) may be a more important in-plus below-cloud removal mechanism of aerosol number than rainout (the opposite is true for aerosol mass), (3) close-in diameter dual peaks in observed cloud distributions may be in part due to different activation characteristics of different aerosol distributions, (4) evaporative cooling at liquid drop surfaces in subsaturated air may be a mechanism of drop freezing (termed "evaporative freezing" here), and (5) heterogeneous-homogeneous freezing may freeze more upper-tropospheric drops than CF, but neither appears to affect warm-cloud hydrometeor distributions or aerosol scavenging substantially.