text
stringlengths 219
2.92k
| label
class label 23
classes |
|---|---|
Surgical staples in cesarean section: a randomized controlled trial.
This randomized controlled trial compares the use of the Auto Suture Poly CS 57 disposable surgical stapler (n = 98) with standard hysterectomy (n = 102) in low transverse cesarean sections.
Subjective assessment of blood loss by the surgeon resulted in lower mean (+/- SEM) total blood loss estimates in the stapled group (492 +/- 24 ml) than in the nonstapled group (579 +/- 38 ml) (p = 0.05).
However, surgeon's estimation of blood loss as a result of the hysterotomy and blood loss estimated by the hemoglobin deficit measured on the second postoperative day did not significantly differ between the two groups.
The use of the stapling device tended to lengthen the total operating time, which averaged 42.5 minutes in the group with the staples and 39.2 minutes in the group with the standard hysterotomy (p = 0.05).
The risk of febrile morbidity, the frequency of endometritis, and the length of hospitalization were similar in the two groups.
Our results do not support the routine use of the Auto Suture Poly CS 57 disposable surgical stapler in low transverse cesarean sections.
| 22Pathological Conditions, Signs and Symptoms
|
Neuroendocrine features of reactive bile ductules in cholestatic liver disease.
Various cholestatic liver diseases are accompanied by a striking increase in the number of bile ductules.
This so-called ductular reaction is thought to arise both from ductular metaplasia of hepatocytes and from proliferation of pre-existing bile ductules.
Previous studies have shown that these reactive bile ductules differ from their normal counterpart in enzyme and immunohistochemical make-up.
Using monoclonal antibodies directed to neuroendocrine markers and immunohistochemistry, we found that reactive bile ductules in cholestatic liver disease display neuroendocrine features.
In all cases of primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), extrahepatic obstruction, and acute hepatitis A, reactive bile ductules expressed the neural cell adhesion molecule (N-CAM) and reacted with monoclonal antibody A2B5.
Both N-CAM and the ganglioside, recognized by A2B5, are restricted to neuroendocrine cells and tissues.
In all but four of these cases, the same bile ductules expressed chromogranin-A, present in the matrix of neuroendocrine granules.
Furthermore, in three cases of longstanding cholestasis, scattered periportal hepatocytes expressed chromogranin-A but not N-CAM.
Other neuroendocrine markers such as neuron-specific enolase, synaptophysin, or myelin-associated glycoprotein were lacking from both bile ductules and hepatocytes.
The neuroendocrine phenotype of bile ductules and hepatocytes was confirmed on electronmicroscopy, demonstrating various numbers of dense-cored, neuroendocrine granules near the peripheral cell membrane in bile ductules as well as in cells intermediate between hepatocytes and bile ductular cells.
In 10 cases of normal liver tissue without ductular reaction, bile ductules lacked neuroendocrine markers except in two cases in which very weak reactivity for chromogranin-A was observed.
These findings illustrate the presence of a new, neuroendocrine cell type that emerges in the liver during cholestasis.
Elucidation of the significance of the neuroendocrine substance(s) produced in the dense cored granules of reactive bile ductules awaits their isolation and characterization.
We can speculate that this molecule plays an autocrine or paracrine regulatory role in the process of ductular metaplasia of hepatocytes or growth of bile ductules.
| 22Pathological Conditions, Signs and Symptoms
|
Mechanisms of edema formation in experimental autoimmune encephalomyelitis. The contribution of inflammatory cells.
Most of the central nervous system (CNS) endothelium regulates the passage of solutes and functions as a blood-brain barrier (BBB).
During experimental autoimmune encephalomyelitis (EAE), an inflammatory demyelinating disease of the CNS, loss of BBB function occurs.
The authors have previously shown an increase in endothelial transcytotic activity associated with decreased mitochondrial content as evidence of BBB dysfunction in EAE.
These changes occurred in the capillary bed and correlated with CNS edema and clinical signs.
In the present report, a fixation procedure before infusion of the intravascular tracer horseradish peroxidase (HRP) in rats at the height of clinical EAE has been used.
In these animals, tracer leakage was only noted in inflamed venules with diameters of 12 to 19 mu.
The authors detected several mechanisms of passive leakage: 1) increased junctional permeability; 2) increased interendothelial space; 3) leakage alongside migrating inflammatory cells.
Some small capillaries showed necrotic changes with minimal tracer leakage.
This report demonstrates that BBB disruption also occurs via nonendocytic mechanisms that may be induced by inflammatory cells.
| 22Pathological Conditions, Signs and Symptoms
|
Metaplastic change in mesenchymal stem cells induced by activated ras oncogene.
3T3 T murine mesenchymal stem cells have the potential to differentiate into a variety of different cell types even though they show a predilection to undergo adipocyte differentiation in vitro.
The possibility that the activated c-Ha-ras (EJras) oncogene might influence the pathway of differentiation of these stem cells is investigated in the current study.
Activated ras oncogene was transfected and stably expressed in 3T3 T cells; assays then were performed to determine its effect on differentiation.
The results show that all EJras-transfected cell lines lose their ability to differentiate to adipocytes and instead differentiate into cells that express many characteristics of macrophages.
Such cells contain numerous cytoplasmic granules, extensive nonspecific esterase activity, and anchorage-independent growth.
The modulation of differentiation pathway from an adipocyte lineage to a macrophagelike cell lineage does not result from the transforming effect of EJras, because a nontransformed cell clone that expresses p21EJras protein also exhibits this modified differentiation pathway.
These data suggest that the EJras oncogene specifically modulates the differentiation pathway of 3T3 T mesenchymal stem cells.
This experimental system should therefore provide an excellent model to evaluate the mechanistic role of EJras in the process of metaplasia.
| 22Pathological Conditions, Signs and Symptoms
|
Effects of spermatic vascular division for correction of the high undescended testis on testicular function.
Orchiopexy with division of the spermatic artery and veins is a commonly used technique for correcting the high undescended testis, although the longterm results have not been clearly defined.
The left spermatic artery and veins of 22 adult Wistar albino rats were divided while preserving the vessels associated with the vas and cremaster muscle (DT).
A sham operation was performed on the left testicle of six additional rats (ST).
At 3 weeks postoperatively, both testes from all rats were removed.
All testes were viable and bled when incised, although bleeding was considerably reduced in testes with DT.
Mean testicular weights after DT were 1,061 +/- 423 mg compared with 1,634 +/- 125 mg for ST rats (p less than 0.02) and 1,508 +/- 119 mg for contralateral testes.
The mean tubular diameter after DT was 220 +/- 37 mu compared with 303.1 +/- 10.7 mu for ST testes (p less than 0.02).
The testicular biopsy score based upon the morphology of the spermatic tubules was 4.46 +/- 3.32 for DT testes and 8.65 +/- 0.23 for ST testes (p less than 0.02) compared with 8.38 +/- 0.18 for contralateral testes and an absolute normal value of 10.
No morphologic abnormalities were observed in the contralateral unoperated testes from any of the rats.
The contralateral testes in 12 additional rats were removed before DT.
The mean testosterone values in these rats with one testicle was 1.43 +/- 0.75 ng/mL.
Three weeks after DT, testosterone values were 0.19 +/- 0.31 ng/mL (p less than 0.01).
It is concluded that division of the main spermatic artery and vein in rats produces testicular atrophy with spermatogenic arrest and interstitial cell dysfunction.
Although collateral blood flow to the testis may be demonstrated, tissue perfusion is inadequate for normal spermatogenesis and endocrine function.
| 22Pathological Conditions, Signs and Symptoms
|
Intravenous fluid load and recovery. A double-blind comparison in gynaecological patients who had day-case laparoscopy.
The effect of intra-operative fluid and dextrose administration upon recovery was tested in a randomised, double-blind trial.
Three groups of 25 patients, each undergoing laparoscopic examination as day cases, were studied.
The two groups who received fluid (20 ml/kg compound sodium lactate solution) showed significant improvement (p less than 0.05) in the variables that reflected hydration.
The fluid group who also received dextrose (1 g/kg) exhibited further significant improvement.
Intra-operative fluid and dextrose administration appears to confer some benefit upon recovery in patients who have minor surgery.
| 22Pathological Conditions, Signs and Symptoms
|
Minitracheotomy: complications and follow-up with fibreoptic tracheoscopy.
Complications and changes in tracheal mucosa after minitracheotomy were evaluated in 28 patients.
Tracheal mucosa was inspected fibreoptically after the insertion of a minitracheotomy cannula, and then at 3-day intervals until the cannula was removed.
Thereafter, assessments were made every third day until the mucosa was considered normal.
Three significant complications occurred: mediastinal puncture, paratracheal entrance of the cannula and subcutaneous emphysema.
Difficulties at insertion of the minitracheotomy cannula were encountered in 15 of 28 patients (54%).
Air flow detected through the cannula in one patient, and lack of air flow in another patient, were misleading signs of the position of the cannula.
Passing a suction catheter in three patients and a normal end-tidal carbon dioxide tracing in one patient, were also found to be misleading.
The correct position and possible complications could be verified only by fibreoptic tracheoscopy.
Changes in the tracheal mucosa were independent of the duration of minitracheotomy therapy.
| 22Pathological Conditions, Signs and Symptoms
|
Intravenous diclofenac sodium. Does its administration before operation suppress postoperative pain?
Intravenous diclofenac sodium was evaluated in a double-blind randomised trial relative to intramuscular diclofenac, intravenous fentanyl, and intramuscular placebo in 160 patients undergoing extraction of impacted lower third molar teeth.
The test drug was administered before operation in an attempt to alleviate postoperative pain.
A 10-cm visual analogue scale was used to assess pain at 30 minutes and one day after surgery, if the patients stayed overnight.
Patients who received intravenous diclofenac had significantly less pain than the other groups 30 minutes after operation.
They also had significantly less pain one day after surgery than the placebo or opioid groups, but not less than the intramuscular diclofenac group.
Capillary bleeding time, in comparison with placebo, was significantly prolonged after the use of intramuscular diclofenac, and a similar but nonsignificant trend was observed in the intravenous diclofenac group.
No problems were encountered with excessive bleeding in any group.
| 22Pathological Conditions, Signs and Symptoms
|
Effect on outcome of prolonged exposure of patients to nitrous oxide.
Prolonged (several days or repeated) exposure to nitrous oxide (N2O) can cause injury or death.
To assess whether relatively prolonged anesthesia with N2O in normal patients might similarly cause untoward effects, we investigated whether the addition of N2O to isoflurane anesthesia caused injury to patients having surgical resection of acoustic neuroma lasting approximately 10 h.
Twenty-six patients undergoing surgical resection of acoustic neuroma were randomly assigned to a regimen that included or excluded N2O (50%-60%) during isoflurane anesthesia plus intravenous adjuvants.
On average, slightly less isoflurane (0.24%) was used during anesthesia with N2O.
We measured standard clinical variables (blood pressure, heart rate), oxygen saturation, neurologic status, pain, and the incidence and type of morbid outcomes.
Exposure to N2O did not increase the incidence of morbid outcomes (including hepatic injury, infection, or hypoxemia), prolong hospitalization, or increase common postoperative complaints such as nausea, vomiting, coughing, or headache.
Patients anesthetized with either regimen were equally satisfied with their anesthetic.
| 22Pathological Conditions, Signs and Symptoms
|
Postoperative hypoxemia after nonabdominal surgery: a frequent event not caused by nitrous oxide.
We tested whether anesthesia that includes nitrous oxide (N2O) results in the development of intraoperative and postoperative pulmonary complications, including hypoxemia.
We also tested whether aging contributes to the development of such complications, particularly when anesthesia includes N2O.
We randomly allocated patients having total hip replacements, carotid endarterectomies, or transsphenoidal hypophysectomies (total n = 270) to an anesthetic regimen with and without N2O (stratified within surgical group).
A heat-and-moisture exchanger was included in the anesthetic circuit of all patients.
Patients were monitored perioperatively and for 1 wk after surgery using intermittent and continuous pulse oximetry to determine oxyhemoglobin saturation.
Intraoperatively, mean oxygen (O2) saturations were lower in patients given N2O, particularly older patients.
Hypoxemia (O2 saturation less than 86%) developed in five patients receiving N2O and in one receiving O2.
This difference was not significant.
Administration of N2O did not decrease postoperative O2 saturation, nor did it alter the incidence of postoperative hypoxemia, cough, or sputum production.
| 22Pathological Conditions, Signs and Symptoms
|
Nitrous oxide and epinephrine-induced arrhythmias.
We asked whether the sympathomimetic effect of nitrous oxide (N2O) predisposed patients receiving N2O to arrhythmias in response to epinephrine administration.
We also asked whether aging contributed to the development of arrhythmias, with or without N2O.
One hundred patients having transsphenoidal hypophysectomy were randomly assigned to receive anesthesia including (n = 49) or excluding (n = 51) N2O.
All patients were given an injection of epinephrine 1:200,000, with 0.5% lidocaine to produce hemostasis.
Using intermittent 12-lead and continuous lead II electrocardiography, we determined the incidence of premature ventricular contraction, isorhythmic atrioventricular (AV) dissociation, and changes in T-wave morphology.
Patients given N2O had a significantly higher incidence of isorhythmic AV dissociation (61.2% vs 41.2%).
A trend toward a higher incidence of multiple premature ventricular contractions (16.3% vs 7.8%) was not statistically significant.
Both anesthetic groups had a high incidence of postoperative changes in T-wave morphology (46.9% in the N2O group vs 50.9% in the group not given N2O).
Aging alone did not affect the incidence of ventricular ectopic beats, isorhythmic AV dissociation, or changes in electrocardiographic morphology, but correlated with the development of ventricular ectopy during N2O anesthesia.
We conclude that the use of N2O correlated with a higher incidence of isorhythmic AV dissociation in response to injection of epinephrine with lidocaine.
| 22Pathological Conditions, Signs and Symptoms
|
Lidocaine local anesthesia for arthroscopic knee surgery.
Forty-five patients were evaluated during knee arthroscopy performed using local anesthesia produced by lidocaine with epinephrine to determine the dose-response relationship for operative analgesia.
Serum lidocaine concentrations were also measured.
Patients were randomized prospectively to receive 20 mL of 0.5%, 1.0%, or 1.5% lidocaine with epinephrine intraarticularly.
Intraoperative discomfort was measured by verbal response on an 11-point linear pain scale.
Pain scores were significantly higher in patients receiving 0.5% lidocaine during the first 45 min of surgery (P = 0.03).
After 45 min, pain scores continued to be higher in the 0.5% lidocaine group than in the 1.0% or 1.5% groups, but the differences were not statistically significant.
Ninety-four percent of patients in the 1.5% lidocaine group were willing to repeat this anesthetic technique for surgery compared with 83% of those in the 1.0% lidocaine group and 75% of those in the 0.5% lidocaine group (P greater than 0.05).
The duration of postoperative analgesia was similar in all groups.
Serum lidocaine concentrations before and 15, 30, 60, and 120 min after instillation of lidocaine were highest in the 1.5% lidocaine group with a peak concentration of 278 ng/mL.
No patient had symptoms of lidocaine toxicity.
We recommend that lidocaine concentrations of 1.0% or 1.5% be used when 20 mL is instilled intraarticularly for knee arthroscopy based on patient comfort and absence of lidocaine toxicity.
| 22Pathological Conditions, Signs and Symptoms
|
Chloroprocaine antagonism of epidural opioid analgesia: a receptor-specific phenomenon?
Sixty healthy patients scheduled for elective cesarean delivery under epidural anesthesia were randomized to receive either lidocaine or 2-chloroprocaine as the primary local anesthetic agent.
When patients first complained of postoperative pain in the recovery room, they were given either fentanyl 50 micrograms or butorphanol 2 mg, epidurally, in a randomized, blinded fashion.
Postoperative analgesia, quantitated on a visual analogue scale, as well as time elapsed until first request for supplemental opioid, did not differ for patients receiving butorphanol after either 2-chloroprocaine or lidocaine anesthesia.
In contrast, epidural fentanyl produced a shorter and lesser degree of sensory analgesia after 2-chloroprocaine use, whereas epidural fentanyl after lidocaine anesthesia provided pain relief similar to that seen in the butorphanol groups.
Side effects were limited to somnolence with butorphanol and pruritus with fentanyl.
No evidence of respiratory depression was seen in any patient.
We conclude that 2 mg of butorphanol epidurally provides approximately 2 to 3 h of effective analgesia after cesarean delivery with either lidocaine or 2-chloroprocaine anesthesia.
Epidural fentanyl seems to be antagonized when 2-chloroprocaine, but not lidocaine, is used as the primary local anesthetic agent.
We suggest a possible mu-receptor-specific etiology for this effect.
| 22Pathological Conditions, Signs and Symptoms
|
Exogenous opioids in human breast milk and acute neonatal neurobehavior: a preliminary study.
Opioid analgesia requirements, distribution into breast milk, and influence on neonatal neurobehavior were evaluated in ten parturient-neonate pairs nursing after elective cesarean section during epidural anesthesia.
Five patients received first a loading dose of intravenous meperidine after umbilical cord clamping, then patient-controlled analgesia (PCA) with intravenous meperidine, and finally meperidine tablets as needed.
Five patients received morphine in the same manner.
Treatment groups showed no differences with respect to neonatal Apgar scores or visual analog scale (VAS) pain or satisfaction scores at 24 and 48 h postpartum.
Breast milk specimens, obtained at 12, 24, 36, 48, 72, and 96 h postpartum and analyzed for opioids and metabolites, showed persistently elevated normeperidine concentrations in the meperidine group.
A blinded psychologist evaluated each infant once on the 3rd day of life with the Brazelton Neonatal Behavioral Assessment Scale (NBAS).
A priori, the "alertness" and three "human orientation" outcomes of the NBAS were chosen for analysis as best measures of opioid-induced effects.
On all four outcomes, neonates in the morphine group scored significantly higher (P less than 0.05) than neonates in the meperidine group.
We conclude that post-cesarean delivery PCA with morphine provides equivalent maternal analgesia and overall satisfaction as that provided by PCA with meperidine, but with significantly less neurobehavioral depression among breast-fed neonates on the 3rd day of life.
| 22Pathological Conditions, Signs and Symptoms
|
Hypoxemia in the postanesthesia care unit: an observer study
To determine the incidence and duration of hypoxemia in the postanesthesia care unit (PACU), 200 patients were investigated in a single-blind observer study.
The number of unrecognized hypoxemic episodes, as well as risk factors and possible association between hypoxemia and postoperative morbidity, were studied.
Oxygenation was monitored continuously with a pulse oximeter.
One or more hypoxemic episodes (SpO2 less than or equal to 90%) were noted in 55% of the patients.
SpO2 values less than or equal to 80% were noted in 13% of the patients.
Supplementary oxygen was given during 55% of the 447 hypoxemic episodes registered.
The hypoxemic episodes were unrecognized by the staff in 95% of the cases.
With stepwise multiple logistic regression analyses, risk factors associated with a higher incidence of hypoxemia were: duration of anesthesia (P less than 0.0001), age (P less than 0.002) and a history of smoking (P less than 0.01).
Patients who had undergone regional anesthesia had a lower risk of hypoxemia (P less than 0.0002).
The occurrence of hypoxemia in the PACU could not be correlated to postoperative morbidity.
We conclude that hypoxemic episodes in our PACU are common and that the routine use of supplemental oxygen combined with normal clinical surveillance did not prevent hypoxemic episodes.
| 22Pathological Conditions, Signs and Symptoms
|
Prehospital prophylactic lidocaine does not favorably affect outcome in patients with chest pain.
STUDY OBJECTIVES: The purpose of our study was to determine the morbidity and mortality in initially stable patients presenting to paramedics with chest pain; to examine possible beneficial effects of its use, including reduction of sudden death syndrome in the prehospital and emergency department setting; and to determine if prophylactic lidocaine is associated with adverse effects in this patient population.
DESIGN AND SETTING: This was a randomized, prospective study using prophylactic lidocaine in patients complaining of chest pain who presented to our paramedic system between January 1984 and January 1988.
TYPE OF PARTICIPANTS: All patients aged 18 years or older with chest pain of suspected cardiac origin who presented to paramedics during the study period were included.
Excluded were patients presenting with warning arrhythmias, second- or third-degree heart block, bradycardias of less than 50, hypotension of less than 90 mm Hg systolic, or known allergy to lidocaine.
INTERVENTIONS: Patients were randomized into two groups, the lidocaine-treated group and the control group.
An initial bolus of 1 mg/kg IV lidocaine was administered to the lidocaine-treated group.
A simultaneous 2 mg/min IV drip was established.
Ten minutes after the first dose of lidocaine, a second bolus of 0.5 mg/kg was administered.
MEASUREMENTS AND MAIN RESULTS: During the study period, 1,427 patients were entered; 704 received lidocaine, and 723 did not.
Discharge diagnoses included acute myocardial infarction (31%), unstable angina (33%), other cardiac problems (7%), and noncardiac problems (29%); overall mortality rate was 7.4%.
There was an equal distribution of deaths between the lidocaine-treated group (57) and the control group (48).
Six patients had a cardiac arrest in the prehospital setting, and 15 had a cardiac arrest in the ED.
Malignant ventricular arrhythmias as the precipitating arrest rhythm in patients with acute myocardial infarctions were similar for the lidocaine-treated and control groups.
The incidence of adverse effects, including hypotension, bradycardias, second- or third-degree heart blocks, tinnitus, and altered mental status, was similar in both groups.
CONCLUSION: There are no benefits from the administration of prehospital prophylactic lidocaine in stable patients with chest pain; therefore, routine use in this setting appears unwarranted.
| 22Pathological Conditions, Signs and Symptoms
|
The diagnostic impact of prehospital 12-lead electrocardiography.
STUDY HYPOTHESIS: It is feasible to apply prehospital 12-lead electrocardiography to most stable prehospital chest pain patients.
Prehospital diagnostic accuracy is improved compared with single-lead telemetry.
POPULATION: One-hundred sixty-six stable adult patients who sought paramedic evaluation for a chief complaint of nontraumatic chest pain.
METHODS: One-hundred fifty-one prehospital 12-lead ECGs of diagnostic quality were obtained by paramedics on 166 adult patients presenting with nontraumatic chest pain.
Paramedics and base station physicians were blinded to the information on acquired prehospital 12-lead ECGs and treated patients according to current standard of care-clinical diagnosis and single-lead telemetry.
Final hospital diagnoses were classified into three groups: acute myocardial infarction (24); suspected angina or ischemia (61); and nonischemic chest pain (66).
Paramedics and base station physicians' clinical diagnoses and prehospital and emergency department ECGs were similarly classified and compared.
Prehospital and ED 12-lead ECGs were read retrospectively by two cardiologists.
RESULTS: Paramedics achieved a high success rate (98.7%) in obtaining diagnostic quality prehospital 12-lead ECGs in 94.6% of eligible prehospital patients.
For patients with acute myocardial infarction, prehospital ECG alone had significantly higher specificity than did the paramedic clinical diagnosis (99.2% vs 70.9%; P less than .001), and significantly higher positive predictive value (92.9% vs 32.7%; P less than .001).
For patients with angina, combining the paramedic clinical diagnosis and the prehospital ECG significantly improved sensitivity (90.2% vs 62.3%; P less than .001) and increased negative predictive value (88.9% vs 71.3%; P less than .02) compared with paramedic clinical diagnosis alone.
There was a high concordance between prehospital and ED ECG diagnosis (99.3% for acute myocardial infarction and 92.8% for angina).
Furthermore, ten patients whose prehospital ECGs demonstrated ischemia and who had final hospital diagnoses of angina or acute myocardial infarction were mistriaged by paramedics and/or received no base station physician-directed therapy.
CONCLUSION: It is feasible to apply prehospital 12-lead electrocardiography to most stable prehospital chest pain patients.
Prehospital 12-lead ECGs have the potential to significantly increase the diagnostic accuracy in chest pain patients, approach congruity with ED 12-lead ECG diagnoses, and may allow for consideration of altering and improving prehospital and hospital-based management in this patient population.
| 22Pathological Conditions, Signs and Symptoms
|
Effects of inflammatory mediators on the responsiveness of isolated human airways to methacholine.
Several studies have suggested that in asthmatics the quantities of inflammatory mediators such as histamine, thromboxane A2 (TxA2), prostaglandin D2 (PGD2), prostaglandin F2 alpha (PGF2 alpha), and leukotriene C4 (LTC4) that are present in the airway lumen are related to the degree of bronchial responsiveness to inhaled methacholine (MCh).
Therefore, we studied the effect of these mediators on the cholinergic responsiveness of isolated human airway segments.
Lung tissue collected at thoracotomy from 30 patients was studied.
Dose-response curves to MCh were obtained from bronchial segments before, during, and after incubation with either a subthreshold or a threshold concentration of histamine (10(-10) or 10(-8) M), the stable TxA2 analogue U46619 (10(-11) or 10(-9) M), PGD2 (5 x 10(-9) or 5 x 10(-7) M), PGF2 alpha (10(-9) or 10(-7) M), or LTC4 (10(-11) or 10(-9) M).
With the exception of LTC4, the presence of any of these mediators at either concentration increased the sensitivity to MCh by a factor of 1.1 to 2 (p less than 0.05, ANOVA).
This increase did not depend on the dose of the mediator (p greater than 0.05, ANOVA).
These data indicate that mediator-induced muscle hypersensitivity can explain a small part of the leftward shift of the dose-response curve to inhaled MCh as observed in asthma.
| 22Pathological Conditions, Signs and Symptoms
|
An objective appraisal of the role of computed tomographic (CT) guided drainage of intra-abdominal abscesses.
Computed tomographic (CT) guided drainage is an important tool in the treatment of intra-abdominal abscess.
Its most important role is in the treatment of small, unilocular, well-placed abscesses.
Success rates in our experience diminish considerably in abscesses involving necrotic tumors or those infected with yeast.
As is frequently characteristic of new technologic procedures, the initial evaluation of the success rate of the procedure is overly optimistic.
The procedure carries a considerable complication rate (13%) and mortality rate (15%).
Most importantly, success is usually evident early; within the first 24 to 48 hours.
After this length of time, careful evaluation to consider further treatment should be contemplated.
| 22Pathological Conditions, Signs and Symptoms
|
Femoral arteriovenous fistula as a complication of percutaneous transluminal coronary angioplasty. A report of five cases.
Arteriovenous fistula (AVF) associated with invasive and diagnostic angiographic procedures is rare.
The incidence is increased with procedures such as percutaneous transluminal coronary angioplasty (PTCA) but is still quite low.
We report five cases of AVF within a 17-month period, representing 0.15 per cent of all cardiac catheterizations and 0.87 per cent of PTCAs.
All five patients presented with groin bruits.
There were two associated pseudoaneurysms and one patient with deep vein thrombosis.
All patients underwent uneventful division of the fistula.
A thorough understanding of the anatomy of the femoral triangle is necessary in order to avoid this complication.
That all fistulas were in the superficial or profunda femoris arteries emphasizes the importance of avoiding a low groin puncture.
Early angiography and surgical intervention are recommended for optimal results.
| 22Pathological Conditions, Signs and Symptoms
|
Management of premature removal of the percutaneous gastrostomy.
Percutaneous endoscopic gastrostomy (PEG) has become the preferred method of enteral access for nutritional support.
With increased use of this modality, complications are encountered more frequently.
Premature withdrawal, inadvertent removal of the gastrostomy tube within the first seven days after insertion, before adherence of the gastric serosa to the parietal peritoneum, has been an indication for laparotomy.
This report describes the treatment of premature withdrawal by immediate endoscopic replacement.
Over an 18-month period, 271 patients underwent insertion of a PEG.
Five patients (1.8%) who inadvertently removed their gastrostomy tube within seven days of insertion were treated with immediate replacement using the retrograde string technique, avoiding laparotomy.
All five PEGs were successfully replaced through the same gastrostomy site.
Despite the presence of pneumoperitoneum, no patient developed peritonitis or other septic complications.
Premature gastrostomy tube withdrawal is safely managed by endoscopic replacement and observation.
Laparotomy is unnecessary and potentially meddlesome.
| 22Pathological Conditions, Signs and Symptoms
|
Tracheotomy in the first year of life.
Much has been written concerning complications of pediatric tracheotomies, but few studies have reviewed the complication rates of tracheotomies performed in the first 12 months of life.
We reviewed the records of 60 patients who underwent tracheotomy in the first year of life between 1976 and 1988.
This study includes 30 full-term infants and 30 premature infants, 16 of whom were very low birth weight preterm infants (less than or equal to 32 weeks' gestation and less than 1,500 g birth weight).
Overall complication rates were 3% intraoperative, 13% early postoperative, and 38% late postoperative.
The early postoperative complication rate in preterm infants was nearly double that of full-term infants.
The late postoperative complication rate of patients undergoing tracheotomy for airway obstruction was more than double that of patients requiring tracheotomy for pulmonary indications.
Duration of tracheotomy, however, was felt to be the most important factor in the development of a late postoperative complication.
| 22Pathological Conditions, Signs and Symptoms
|
Hiccups and breathing in human fetuses.
Serial recording in 45 low risk fetuses throughout the second and third trimesters showed that hiccups were the predominant diaphragmatic movement before 26 weeks' gestational age and that there was a significant negative correlation with gestational age.
There was a pronounced reduction between 24 and 26 weeks, which was the result of a decrease in the number of episodes of hiccups rather than a change in the duration of episodes.
In contrast, fetal breathing was positively correlated with gestational age, the greatest increase in breathing occurring between 26 and 32 weeks' gestation.
This was the result of both an increase in the number and duration of episodes.
From the time that rest-activity cycles of behaviour could be determined in recordings, both breathing and hiccups were dependent on behavioural state or cycle, occurring predominantly during active episodes.
This association between quiet and active behaviour and breathing did not alter with increasing gestational age, and the variables in fetal behavioural state became increasingly closely linked.
The importance of prolonged and repeated recording, and also the need to take account of other variables in fetal behaviour, before any sinister conclusions can be drawn about the absence of fetal breathing is emphasised.
| 22Pathological Conditions, Signs and Symptoms
|
Blood conservation in cardiac surgery.
We reviewed current blood conservation techniques and their use in cardiac surgery.
Avoidance of aspirin preoperatively is an important blood conservation measure.
Patients scheduled for an elective operation should participate in autologous predonation programs.
With careful monitoring, patients with major coronary artery disease can safely donate blood preoperatively.
Intraoperative processing of blood withdrawn before cardiopulmonary bypass provides autologous platelet-rich plasma for infusion after reversal of heparin sodium.
Blood collected from the field during operation and blood remaining in the oxygenator after bypass can also be processed to yield washed and concentrated red blood cells for reinfusion.
Randomized, prospective studies document that postoperative autotransfusion is both safe and effective in reducing homologous blood use.
Aprotinin reduces plasma protein activation and platelet damage during bypass.
The integration of available blood conservation techniques into a comprehensive program combined with careful consideration of the indications for transfusion may allow more patients to avoid transfusion entirely.
| 22Pathological Conditions, Signs and Symptoms
|
Continuous epidural hydromorphone for postthoracotomy pain relief
Forty-four patients were treated with a continuous infusion of lumbar epidural hydromorphone (0.05%) after thoracic operations.
Postoperatively, visual analog pain scores were obtained.
On postoperative day 1 and 2, more than 90% of the patients experienced either no pain (visual analog pain scale = 0) or mild pain (visual analog pain score = 1 to 3) at rest.
The incidence of side effects (hypoventilation, pruritis, and nausea) was less than reported with other epidurally administered opioids.
Continuous infusion of lumbar epidural hydromorphone produced safe, predictable analgesia after thoracotomy.
| 22Pathological Conditions, Signs and Symptoms
|
Neuropsychological assessment of monozygotic twins discordant for schizophrenia.
A comparison of monozygotic twins discordant for schizophrenia controls for genetic variance and reduces variance due to environmental circumstances, thus serving to highlight differences due to phenotypic-related variables.
In this study, we assessed 16 such twin pairs on a wide range of neuropsychological tests.
The affected twins tended to perform worse than their unaffected counterparts on most of the tests.
Deficits were especially severe on tests of vigilance, memory, and concept formation, suggesting that dysfunction is greatest in the frontotemporal cortex.
While manifest symptoms were not highly associated with neuropsychological scores, global level of functioning was.
To address the issue of genetic liability, we also compared the sample of discordant unaffected twins with a sample of seven pairs of normal monozygotic twins.
No significant differences between the groups were found for any neuropsychological test.
In fact, the results suggest that neuropsychological dysfunction is a consistent feature of schizophrenia and that it is related primarily to the clinical disease process and not to genetic or nonspecific environmental factors.
| 22Pathological Conditions, Signs and Symptoms
|
Bilateral phrenic nerve palsy associated with open-heart surgery.
The incidence of phrenic nerve palsy after open-heart surgery has been estimated at 10%, but it is usually unilateral and does not cause symptoms.
Bilateral phrenic nerve injury after coronary artery bypass surgery is a rare complication.
This case report describes a patient who developed bilateral phrenic nerve palsies and required prolonged ventilatory support.
Denervation of both hemidiaphragms was documented by needle electromyography four weeks after bypass surgery.
The patient required total ventilatory support for three months and partial ventilatory support for an additional three months.
This case demonstrates the usefulness of electromyographic screening for documentation and prognostication after phrenic nerve injury.
The cause of the lesion was unclear, but hypothermia and stretch were leading hypotheses.
This patient developed the phrenic nerve palsies despite using a cardiac insulation pad.
| 22Pathological Conditions, Signs and Symptoms
|
Myotonic dystrophy: quantification of muscle weakness and myotonia and the effect of amitriptyline and exercise.
The purpose of this study was to quantify the degree of muscle weakness and myotonia in 12 patients with myotonic dystrophy (MD), and to quantitatively determine the effects of a four- to six-month therapeutic trial of amitriptyline.
Patients had exercised with weights for one or more years.
Some had shown initial improvement in muscle strength, but had reached a plateau; others had not improved when the study began.
Muscle weakness was quantified by comparing the five-second maximum voluntary contraction (MVC) in newtons (N) per kg (body weight) of 12 patients and 20 healthy subjects.
Knee extensor, elbow flexor, and first dorsal interosseous (FDI) muscles were compared.
Myotonia was quantified by measuring relaxation times (RTs) at the end of the five-second MVC produced by FDI, as the time taken for the MVC to decrease by 50% and 75% (referred to as 1/2 and 3/4RT).
The results were as follows: (1) the mean muscle strength of each of the three muscles of the patients was significantly (p less than .001) reduced compared with healthy subjects; and (2) 1/2 and 3/4RT means of the patients (vs healthy subjects) were significantly prolonged (p less than .01).
Eight of the patients participated in a therapeutic trial of amitriptyline.
Therapeutic effects were quantified by measuring muscle strength, 1/2 and 3/4RT, and percent change in evoked muscle action potential (MAP) from the FDI muscle after a ten-second MVC, to determine change in excitability.
Mean muscle strength of FDI improved from .27 to .33N/kg, (p less than .05).
| 22Pathological Conditions, Signs and Symptoms
|
Aortic occlusion and vascular isolation allowing avascular hepatic resection.
Occlusion of the supraceliac abdominal aorta and hepatic vascular isolation were employed in a series of 15 patients as a definitive method to allow avascular hepatic resection.
The series was compared with an earlier group of patients treated conventionally.
In the avascular hepatic resection group there was no mortality; hypotension did not occur at the time of hepatic vascular isolation; rapid, accurate excision of the hepatic lesions could be achieved in a bloodless field; resection of midline lesions and those involving the great veins was possible; and "segmentectomies," or resections crossing segmental boundaries, could be performed where previously formal hepatic lobectomies were required.
Concomitantly, the greatest amount of uninvolved hepatic parenchyma remained in situ.
There was increased ease of operative management, reduced blood loss, and reduced operating time (mean, 2.8 hours).
| 22Pathological Conditions, Signs and Symptoms
|
Circadian variation in onset of acute ischemic stroke.
A circadian pattern for the onset of myocardial and cerebral infarction has been identified.
To evaluate this phenomenon further, we analyzed prospectively collected data from 151 patients with acute ischemic stroke.
The number of strokes per 6-hour period were the following: midnight to 6 AM, 20 (13%); 6 AM to noon, 86 (57%); noon to 6 PM, 21 (14%); and 6 PM to midnight, 24 (16%).
This pattern was not affected by previous use of aspirin.
The most frequent time of onset was 6 AM to noon for all subgroups of ischemic stroke: small artery, 71%; cardioembolic, 62%; large artery atherothrombotic, 57%; large artery atheroembolic, 46%; and "other" or unknown cause, 40%.
We also investigated the time between awakening and stroke onset in 145 patients and found that 24% of ischemic strokes occurred within the first hour after awakening.
Our data demonstrate that an early morning peak exists for all subtypes of stroke.
Our data also suggest that the most critical period is the first hour after awakening.
| 22Pathological Conditions, Signs and Symptoms
|
Nontraumatic coma. Glasgow coma score and coma etiology as predictors of 2-week outcome.
In 1987 and 1988, we carried out a prospective study of patients older than 10 years with nontraumatic coma in the intensive care units of Columbia-Presbyterian Medical Center, New York, NY.
Of 188 patients with Glasgow Coma Scale (GCS) determinations within 72 hours, 61% were dead or in persistent coma by 2 weeks from onset.
Age, sex, and ethnicity did not influence outcome.
The 2-week outcome for patients with initial GCS of 3 to 5 was 14.8% awake; 85.2% were dead or in persistent coma.
For the GCS 6 to 8 group, 53.1% were awake and 46.9% were dead or in persistent coma.
Hypoxic or ischemic coma had the worst 2-week outcome (79% dead or comatose); coma caused by metabolic disease or sepsis (68%), focal cerebral lesions (66%), and general cerebral diseases (55%) were intermediate, while drug-induced coma had a favorable outcome (27% dead or comatose).
The independent predictors of 2-week outcome were the first GCS and drug-induced coma.
The predicted probability of waking at 2 weeks was eight times better for drug-induced coma than other causes when GCS was held constant.
Patients with an initial GCS score of 6 to 8 were seven times more likely to waken than those with a score of 3 to 5.
The motor subscore alone was a significant independent predictor of 2-week outcome.
Modification of coma score to include etiology may give more accurate predictions of 2-week outcome after nontraumatic coma.
| 22Pathological Conditions, Signs and Symptoms
|
Long-term effect of dopaminergic drugs in restless legs. A 2-year follow-up.
Thirty patients with restless legs syndrome, who initially had all responded well to treatment with levodopa and benserazide, were studied as to the long-term effect of the drugs (at least 2 years).
During the 2-year period, two patients were switched from levodopa to bromocriptine.
Two patients no longer needed levodopa; one of them had developed paraplegia and in the other the symptoms of restless legs syndrome had disappeared completely.
The remaining 26 patients continued to use levodopa.
Eight patients maintained the original dose, nine had to use an increased dose, and nine found a decreased dose to be sufficient.
The only side effect was transient nausea reported by two of the 30 patients.
The study showed that the relief of symptoms of restless legs syndrome by dopaminergic drugs does not wear off with the passage of time, that side effects are minimal even with long-term use, and that the dose needed to obtain relief may increase as well as decrease.
| 22Pathological Conditions, Signs and Symptoms
|
Hemifacial spasm in Rochester and Olmsted County, Minnesota, 1960 to 1984.
The incidence of hemifacial spasm in residents of Olmsted County, Minnesota, was studied by reviewing the medical records of patients residing in the community between 1960 and 1984.
The average annual incidence rate was 0.74 per 100,000 in men and 0.81 per 100,000 in women, age-adjusted to the 1970 US white population.
The average prevalence rate was 7.4 per 100,000 population in men and 14.5 per 100,000 in women.
The incidence and prevalence rates were highest in those from 40 to 79 years of age.
| 22Pathological Conditions, Signs and Symptoms
|
The Marinesco-Sjogren syndrome examined by computed tomography, magnetic resonance, and 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography.
The Marinesco-Sjogren syndrome is an autosomal recessive degenerative disorder characterized by congenital cataracts, cerebellar ataxia, spasticity, mental deficiency, and skeletal abnormalities.
We studied two adult siblings with Marinesco-Sjogren syndrome using anatomic and metabolic brain imaging techniques to characterize the pattern and nature of abnormalities in the brain.
Computed tomographic and magnetic resonance imaging showed diffuse brain atrophy of mild to moderate degree, involving primarily the white matter of the cerebrum, cerebellum, brain stem, and cervical spinal cord.
The pattern of atrophy resembled that seen in diffuse leukoencephalopathies.
Measurements of local cerebral glucose metabolic rates with positron emission tomography revealed no statistically significant differences from normal control subjects in most regions, but metabolic rate was decreased in the thalamus in one patient.
The findings support a diffuse white matter disorder in Marinesco-Sjogren syndrome.
| 22Pathological Conditions, Signs and Symptoms
|
Background review and current concepts of reperfusion injury.
We define the concept of reperfusion injury, and we present a background chronology of experimental work supporting and questioning this concept.
We identify several new influences, such as current clinical interest in thrombolytic therapy for acute ischemia of heart and brain and the growing recognition of endothelium as a regulator of homeostasis.
We propose that these influences will encourage a reexamination of reperfusion injury as a factor in the ultimate outcome of tissue exposed to reversible ischemia.
We briefly discuss the major mechanisms presently implicated in reperfusion injury--loss of calcium homeostasis, free radical generation, leukocyte-mediated injury, and acute hypercholesterolemia.
| 22Pathological Conditions, Signs and Symptoms
|
Aplasia cutis congenita and arteriovenous fistula. Case report and review.
We describe a child with congenital aplasia cutis congenita of the scalp and an occult giant posterior fossa arteriovenous fistula.
Previous case reports of central nervous system malformations associated with aplasia cutis congenita are reviewed.
The exact incidence of such malformations is unknown.
All patients with aplasia cutis congenita should undergo a neurologic evaluation, and their families should be examined for similar lesions.
Early central nervous system imaging and other workup may be required, especially if plastic surgery in the head region is being planned.
| 22Pathological Conditions, Signs and Symptoms
|
Audiometric and subjective assessment of hearing handicap.
This study compares self-perceived assessment of hearing handicap with audiometrically derived measures of hearing handicap in a sample of elderly persons.
Subjects were evaluated by traditional audiometric tests, the Speech Perception in Noise test, and the Hearing Handicap Inventory for the Elderly, a self-assessment questionnaire.
Hearing handicap was also calculated by the audiometrically derived American Academy of Otolaryngology (1979) method.
Our results are consistent with other studies that indicate a low correspondence between audiometric measures of hearing handicap and self-assessment of hearing handicap.
Furthermore, if the Hearing Handicap Inventory for the Elderly is considered the true measure of hearing handicap, our data indicate that the American Academy of Otolaryngology method tends to overestimate handicap among persons with no self-perceived hearing handicap and underestimates handicap among persons with significant self-perceived hearing handicap.
| 22Pathological Conditions, Signs and Symptoms
|
Vitamin B6 in the treatment of the premenstrual syndrome--a review [published erratum appears in Br J Obstet Gynaecol 1991 Mar;98(3):329-30]
A search of the literature yielded 12 controlled trials on vitamin B6 in the treatment of the premenstrual syndrome.
These are discussed with emphasis on methodological aspects.
A major drawback of the trials is the limited number of patients included.
The existing evidence of positive effects of vitamin B6 is weak, and some well-designed trials with positive results would be needed to change this view.
| 22Pathological Conditions, Signs and Symptoms
|
Effect of nontransmural necrosis on epicardial potential fields. Correlation with fiber direction.
The effect of nontransmural necrosis on epicardial potential distributions was studied in 13 dogs.
In previous studies, left ventricular epicardial pacing generated epicardial potential maps at QRS onset with a negative central area and two positive areas that faced the portions of the wavefront propagating along fibers.
Subsequently, the positive areas expanded in a counterclockwise direction by 90 degrees to 120 degrees.
In those studies, the rotatory expansion of the positive areas was tentatively attributed to the spread of excitation through deep myocardial layers, where fiber direction rotated counterclockwise from epicardium to endocardium.
To test this hypothesis, we tried to interrupt the counterclockwise expansion of the positive area by creating localized, nontransmural necrosis at various depths in the left ventricular wall by injection of formalin or application of laser energy.
Epicardial potential maps were obtained from a grid of 12 x 15 electrodes on a 44 x 56-mm area.
Epicardial pacing from selected sites generated epicardial maps in which some positive areas were missing compared with controls.
The direction of the straight line joining the pacing site to the site of missing positivity correlated well with the average fiber direction in the necrotic mass (r = 0.82, p less than 0.01).
Angle between epicardial fiber direction and the straight line described above correlated well with the average depth of the necrosis, expressed as percent of the wall thickness (r = 0.95, p less than 0.01).
These data support the hypothesis that the counterclockwise expansion of the epicardial positivity occurring after epicardial pacing results from excitation spreading along deep fibers.
| 22Pathological Conditions, Signs and Symptoms
|
Bleeding time prolongation with streptokinase and its reduction with 1-desamino-8-D-arginine vasopressin.
The mechanism by which treatment with thrombolytic agents causes bleeding is not known.
Recently, frequency of bleeding events has been shown to correlate with bleeding time, particularly in individuals treated with aspirin.
We examined the effects of streptokinase (20,000-60,000 IU/kg) on bleeding time in 40 rabbits pretreated with aspirin, a model for fibrinolytic therapy.
We then tested the effects of 1-desamino-8-D-arginine vasopressin (DDAVP) (0.3 microgram/kg), an agent known to reduce bleeding time in a variety of bleeding disorders, in 20 rabbits and compared the results with those of a control group of rabbits receiving normal saline placebo.
Aspirin increased the bleeding time from a baseline mean +/- SEM value of 119 +/- 15 to 191 +/- 34 seconds in the control group and from 114 +/- 6 to 188 +/- 18 seconds in the experimental group.
The addition of streptokinase increased the bleeding time to 592 +/- 119 seconds in the control group and 810 +/- 114 seconds in the experimental group (p = NS).
Subsequent infusion of DDAVP decreased the bleeding time in the experimental group to 302 +/- 29 seconds (p less than 0.01 versus streptokinase) compared with 572 +/- 79 seconds (p = NS versus streptokinase) in the control animals given saline placebo.
In a subset of rabbits receiving aspirin and streptokinase (40,000-60,000 IU/kg), samples were obtained for platelet aggregation (n = 16), von Willebrand factor antigen concentration (n = 17), and von Willebrand factor multimer distribution (n = 14).
Maximal rates of ADP-induced platelet aggregation were not affected by DDAVP infusion, nor was the plasma concentration of von Willebrand factor antigen, quantified by an immunoradiometric assay, significantly affected by DDAVP infusion.
Furthermore, the von Willebrand factor multimer ratio decreased with DDAVP administration.
These findings indicate that aspirin and streptokinase combined result in a marked increase in bleeding time that can be reduced by DDAVP.
This effect of DDAVP is not accompanied by an increase in platelet aggregation response, plasma von Willebrand factor antigen concentration, or von Willebrand factor multimer ratio.
| 22Pathological Conditions, Signs and Symptoms
|
Channel specificity in antiarrhythmic drug action. Mechanism of potassium channel block and its role in suppressing and aggravating cardiac arrhythmias.
Although work on class III antiarrhythmics remains at an early stage, these agents still appear to possess greater efficacy and less proarrhythmia than conventional class I agents in those experimental arrhythmia models considered to be most representative of the clinical situation.
Although prolongation of repolarization carries with its own tendency for pause-dependent arrhythmogenesis (i.e., torsade de pointes), available data suggest that this may be a function of nonspecificity in potassium channel block rather than a general characteristic of class III activity.
The availability of new and more selective blockers of specific cardiac potassium channels under development as class III agents have already helped to clarify basic questions about the ionic mechanism of repolarization in the heart, and one hopes that a growing clinical data base will eventually determine the relative safety and efficacy of these agents in preventing symptomatic and life-threatening arrhythmias.
| 22Pathological Conditions, Signs and Symptoms
|
Chronic illness and depressive symptoms in the elderly: a population-based study.
A cross-sectional study of the distribution of depressive symptoms and association between depressed mood and chronic illness was conducted in a geographically defined population in southern California of 1617 men and women aged 65 years and older.
The prevalence of depressed mood for the total population was 5.2%.
Women exhibited a significantly higher mean depressive symptom score and a prevalence rate almost twice that of men.
Depressive symptoms were associated with several risk factors in both sexes, including age, self-perception of current health status, number of reported chronic diseases and medications and amount of exercise.
However, the relationship between physical illness and depressive symptoms appeared to differ by sex with respect to the nature of the disease or disability and the type of medication currently used.
These findings indicate that the risk of depression does not diminish with age among the elderly as other studies have suggested.
| 22Pathological Conditions, Signs and Symptoms
|
L-tyrosine potentiates the anorexia induced by mixed-acting sympathomimetic drugs in hyperphagic rats.
The effects of L-tyrosine (L-TYR) on the anorectic activity of several mixed-acting sympathomimetics were determined during the dark cycle in rats made hyperphagic by food deprivation.
L-TYR (200 mg/kg) significantly potentiated the anorectic activity of phenylpropanolamine, (-)-ephedrine and (+)-amphetamine by 48, 50 and 37%, respectively.
When the dose of L-TYR was varied (25-400 mg/kg), a significant dose-dependent relationship was noted.
The observed potentiation was positively correlated with increases in brain TYR concentrations; blockade of L-TYR uptake into the brain by the coadministration of L-valine prevented this potentiation.
Various other L-amino acids, as well as D-TYR, failed to mimic the potentiating action of L-TYR.
As determined by alpha-methyl-p-TYR pretreatment, the L-TYR-induced potentiation was dependent upon increased catecholamine synthesis.
Although various other mixed-acting sympathomimetic anorexiants were similarly potentiated by L-TYR, the direct-acting beta-2 adrenoceptor anorexiants, salbutamol and methoxyphenamine, were not.
These results indicate that L-TYR specifically potentiates the anorectic activity of the studied mixed-acting sympathomimetics and are consistent with the requirement of the central conversion of L-TYR to catecholamines via TYR hydroxylase for this response.
The possibility that the effect of mixed-acting sympathomimetics is normally limited by the availability of L-TYR is suggested.
| 22Pathological Conditions, Signs and Symptoms
|
Peripheral opioid receptors mediating antinociception in inflammation. Evidence for activation by enkephalin-like opioid peptides after cold water swim stress.
This study utilized inhibitors of the enzymatic degradation of enkephalins to investigate the possibility that this class of opioid peptides contributes to the stress-induced antinociception seen in inflamed peripheral tissues of rats with Freund's complete adjuvant-initiated unilateral hind paw inflammation.
Following a 1-min cold water swim stress, rats previously injected in both hind paws with vehicle showed a transient elevation of paw pressure threshold, which was much greater in inflamed than in noninflamed paws and returned to control levels within 15 min.
This preferential antinociception was significantly pronounced and prolonged in rats previously injected bilaterally with a cocktail of the enkephalinase inhibitors thiorphan (0.2 mg intraplantar) and bestatin (0.2 mg intraplantar).
The enhancement of stress-induced antinociception by thiorphan/bestatin was dose-dependently antagonized by tertiary naloxone (0.125-2 mg kg-1 s.c.).
Evidence for a peripheral site of action of enkephalin-like peptides in this model was provided by the antagonism of the actions of thiorphan/bestatin by quaternary naltrexone (10-20 mg kg-1 s.c.).
Systemic administration of the orally active enkephalinase inhibitor SCH 34826 (5-40 mg kg-1 i.p.) was also able to dose-dependently potentiate the preferential stress-induced antinociception in a naloxone (1 mg kg-1 s.c.) reversible manner.
| 22Pathological Conditions, Signs and Symptoms
|
Gadolinium-enhanced magnetic resonance imaging in Bell's palsy.
Inflammation of the facial nerve in Bell's palsy can be demonstrated on gadolinium-enhanced magnetic resonance imaging.
We have studied a series of 17 Bell's palsy patients with gadolinium-enhanced magnetic resonance imaging, and the purpose of this paper is to report our findings and discuss their significance.
Most acute Bell's palsy cases demonstrate facial nerve enhancement, usually in the distal internal auditory canal and labyrinthine/geniculate segments.
Other segments demonstrate enhancement less often.
Gadolinium enhancement occurs regardless of the severity of the paralysis and can persist after clinical improvement of the paralysis.
The findings of this study corroborate other evidence that the segments of the facial nerve most often involved in Bell's palsy are the only segments that are most often enhanced with gadolinium-enhanced magnetic resonance imaging.
The role of gadolinium-enhanced magnetic resonance imaging in the management of Bell's palsy patients is discussed.
| 22Pathological Conditions, Signs and Symptoms
|
The use of gadolinium-enhanced magnetic resonance imaging to determine lesion site in traumatic facial paralysis.
Gadolinium-enhanced magnetic resonance imaging has been used to evaluate 20 patients with surgically confirmed facial nerve lesions.
When the nerve could be seen, gadolinium-enhanced magnetic resonance imaging accurately revealed the lesion site as well as the known extent, which in some cases was not predicted by topognostic testing.
This technique appears to provide accurate lesion-site testing and may have importance in surgical planning.
Currently used topognostic tests of facial nerve function are frequently inaccurate and can only determine the most proximal lesion site when there are multiple or extensive lesions.
The focal nerve enhancement seen in nerve injury, globally increased signal intensity within the temporal bone after trauma, and increased signal intensity within the dura after surgery can occasionally mask nerve lesions and may be confused with tumors.
| 22Pathological Conditions, Signs and Symptoms
|
A computerized laboratory alerting system.
A computerized laboratory alerting system (CLAS) has been developed as part of an ongoing effort to improve the quality of care at LDS Hospital.
The system identifies potentially life-threatening conditions on the basis of laboratory findings and then generates appropriate warnings and transmits them to clinicians.
Use of the system has led to a significant increase in the proportion of patients in life-threatening situations who have received appropriate care (50.8% before implementation vs.
62.5% afterward, P less than 0.05).
Among patients with hypokalemia, falling potassium levels, hyperkalemia, hypokalemia during treatment with digoxin, hyponatremia, falling sodium levels, hypernatremia, hypoglycemia, or hyperglycemia, the average length of time spent in the life-threatening situation has decreased from 30.4 to 15.7 hours (P less than 0.05) and the average length of stay has decreased from 14.6 to 8.8 days (P less than 0.05).
There has been little change in the proportion of patients with findings indicating metabolic acidosis who have received appropriate care (32.3 vs.
34.6%).
We conclude that CLAS has an important role in patient care at our hospital.
| 22Pathological Conditions, Signs and Symptoms
|
Evaluating hematuria in children. Where to start and how to proceed.
Bleeding from somewhere along the urinary tract is not unusual in children.
Of the many causes, systemic infection and trauma are among the most common.
History taking and physical examination should be careful and complete, because the results obtained help direct the laboratory evaluation.
Diagnostic testing always begins with urinalysis but may progress to intravenous urography, voiding cystourethrography, endoscopic procedures in the upper and lower urinary tract, sonography, arteriography, or renal biopsy.
Some cases remain unexplained and require follow-up to assess renal function.
| 22Pathological Conditions, Signs and Symptoms
|
Hypothermia. Safe and efficient methods of rewarming the patient.
Hypothermia, a relatively common problem in the winter months, can cause significant morbidity.
It presents in a variety of situations and affects a wide age range.
Diagnosis requires a high index of suspicion, because the symptoms, which are primarily related to the central nervous system, are not distinctive.
Appropriate management requires accurate measurement of core body temperature.
Treatment is centered on rewarming the patient safely and efficiently while providing other supportive measures.
Care should be taken to avoid arrhythmias.
Simple precautions greatly reduce the risk of hypothermia.
| 22Pathological Conditions, Signs and Symptoms
|
The efficacy of methylprednisolone in reducing flap edema.
It has been suggested that systemic steroids reduce postoperative flap edema.
This has been poorly documented by several reports based on subjective clinical observations.
In an effort to provide quantitative data on methylprednisolone and edema, a flap edema model in the rat was developed based on the inferior epigastric vessels.
Significant edema developed after 48 hours.
Differing intraoperative doses of methylprednisolone were studied, producing a dose-response curve.
A single low dose of intraoperative steroid is effective in reducing flap edema; previously recommended doses are probably excessive.
| 22Pathological Conditions, Signs and Symptoms
|
Treatment of chronic facial palsy by transplantation of the neurovascularized free rectus abdominis muscle.
We performed neurovascularized free rectus abdominis muscle transplantations in two patients with chronic facial palsy.
In one patient, the postoperative course was uneventful, but the patient died from rupture of esophageal varices.
In the other patient, both morphologic and functional results were satisfactory.
Therefore, the rectus abdominis muscle is considered to be a suitable donor for muscle transplantation for the treatment of chronic facial palsy.
The rectus abdominis muscle is advantageous in that (1) simultaneous operations by two teams are possible with the patient in the supine position, (2) it is supplied by long nerves and long and large vessels, (3) it is flat and consists of segments with appropriate lengths, (4) the force and distance of contraction are appropriate, and (5) the tendinous intersections are suitable for anchoring sutures.
| 22Pathological Conditions, Signs and Symptoms
|
Simplified technique for isolating vascularized rib periosteal grafts.
A modified technique for obtaining a vascularized rib periosteal segment utilizing the posterolateral approach is presented.
The technique avoids the inclusion of a large muscle cuff or the pleura around the isolated rib segment and therefore minimizes donor-site morbidity and chest complications previously associated with this approach.
| 22Pathological Conditions, Signs and Symptoms
|
Obstructive jaundice: use of expandable metal endoprosthesis for biliary drainage. Work in progress.
Expandable metal endoprostheses were implanted transhepatically in 61 patients with obstructive jaundice.
Fifty-three patients had malignant and eight had benign obstructions.
Because of the small diameter of the compressed stent (7 F), primary implantation of the stent without a previous catheter drainage was preferred.
Postprocedural complications occurred in three patients (5%) (biliary pleuritis, peritonitis, hepatic artery aneurysm).
The 30-day mortality rate was 8.2%.
Reocclusions were observed in six of the patients with malignant obstructions (11%) (observation period, 1-10 months; mean, 4.5 months) and in two of the patients with benign stenoses (25%) (observation period, 3-21 months; mean, 9 months).
The higher reocclusion rate of benign obstructions must be interpreted with care because of the small number of patients.
From their preliminary experience, the authors conclude that expandable metal endoprostheses offer patency rates equal to those of plastic stents.
The implantation trauma is reduced due to the small 7-F introducing catheter system.
| 22Pathological Conditions, Signs and Symptoms
|
Simplified technique for control of femoral arterial bleeding after coronary angioplasty.
A method of achieving arterial control by inserting an embolectomy catheter through the femoral introducer sheath in the patient with femoral arterial bleeding after PTCA is described herein.
This approach allows quick control with less dissection and negligible blood loss.
| 22Pathological Conditions, Signs and Symptoms
|
Effects of 1.32-micron Nd-YAG laser on brain thermal and histological experimental data.
Considering that the 1.32-microns Nd-YAG laser should have physicothermal properties close to those of the CO2 laser, a series of experiments were conducted on rat cortex (N = 51).
Three laser wavelengths were compared: CO2 laser (10.6 microns), 1.06-microns Nd-YAG, and 1.32-microns Nd-YAG lasers.
For each shot, temperature measurements were recorded with an infrared thermographic videocamera.
The digitized signals were figured as thermal profiles and temperature developments.
Ninety-five shots were correctly studied and analyzed: CO2, N = 29; 1.06-microns Nd-YAG, N = 20; 1.32-microns Nd-YAG, N = 46.
The histological lesions produced by these three lasers were compared on animals killed 24 hours (N = 20), 8 days (N = 20), and 30 days (N = 5) after the laser impacts.
For equivalent densities of energy, the depth of cortical necrosis was comparable for the CO2 laser (200-250 microns) and the 1.32-microns Nd-YAG laser (210-260 microns) whatever the date of death; the 1.06-microns Nd-YAG laser shots were responsible for much more important damage (400-550 microns).
Because of its important absorption in water and nervous tissue, the authors consider the 1.32-microns Nd-YAG laser most suitable for neurosurgery, particularly because it is conducted through optic fibers, and therefore is easy to handle during neurosurgical procedures.
| 22Pathological Conditions, Signs and Symptoms
|
Cytomegalovirus infections in pediatric liver transplantation.
From 1986 to 1989, 26 consecutive pediatric liver transplant recipients were followed up at The Hospital for Sick Children, Toronto, Canada.
The patients were reviewed to assess the incidence of infection with cytomegalovirus, the severity of disease, and the relationship of recipient and donor serostatus to cytomegalovirus disease.
Overall, the incidence of infection was 54% (14/26).
Over 90% of patients who were seropositive or whose donors were seropositive developed evidence of cytomegalovirus infection after transplantation.
Forty-three percent (6/14) of those with cytomegalovirus infections developed severe, fatal cytomegalovirus disease, despite treatment with immunoglobulins and ganciclovir (Syntex Laboratories Inc, Palo Alto, Calif) or foscarnet sodium (Astra, Pharmaceutical Products Inc, Westborough, Mass).
Of all posttransplant deaths, two thirds were associated with severe cytomegalovirus infection.
Cytomegalovirus-related deaths occurred in three of four seronegative patients with seropositive donors and three of six seropositive patients with seropositive donors.
Therefore, a seropositive donor appeared to be a major risk factor for severe cytomegalovirus disease.
| 22Pathological Conditions, Signs and Symptoms
|
Effects of pill-giving on maintenance of placebo response in patients with chronic mild depression
Fifty outpatients with mild, chronic, mood-reactive depression whose mood improved markedly after a 10-day single-blind placebo trial were randomly assigned in a double-blind design either to have their placebo medication discontinued or to have it maintained for an additional 6 weeks.
Half of the patients in each condition relapsed within 6 weeks, indicating that pill-taking itself does not influence maintenance of placebo response.
Placebo response was more likely to be maintained in patients who were currently married.
At the end of 3 months, the overall relapse rate was 58%.
The authors raise questions about the utility of the initial 10-day placebo washout in antidepressant clinical trials, and they discuss limits on the generalizability of their findings.
| 22Pathological Conditions, Signs and Symptoms
|
Outcome of patients with chronic affective disorder: a five-year follow-up.
Patients with major depression, mania, or schizo-affective disorder that had been present without remission for 2 years or more at intake (N = 129) were followed prospectively for 5 years, as were 580 patients who had been ill for shorter periods at intake.
Despite very substantial durations of episode, three-quarters of the chronic patients recovered, although recovery occurred much later in the follow-up period than it did among the nonchronic patients.
Factors associated with recovery were less severe illness at intake, lack of psychotic features, good friendship patterns in adolescence, and, most important, a relatively high maximum level of functioning in the 5 years preceding intake.
| 22Pathological Conditions, Signs and Symptoms
|
Late luteal phase dysphoric disorder in young women.
The authors determined the prevalence of late luteal phase dysphoric disorder in 217 university women aged 17-29 years.
Unaware of the focus on premenstrual syndrome (PMS), the participants rated DSM-III-R symptoms of late luteal phase dysphoric disorder over 90 days.
Using a 30% or greater premenstrual change as an index of luteal variation, the authors found that 10 women (4.6%) met the symptom criteria during two menstrual cycles.
Compared to 25 young women seeking treatment for PMS who met the same diagnostic criteria, the 10 women from the university sample reported significantly less fatigue and impaired concentration and somewhat less severe depression and overall symptoms.
| 22Pathological Conditions, Signs and Symptoms
|
Conduction system injury after aortic valve dilation in the dog single- versus double-balloon catheters.
The range of morbidity induced by valvuloplasty is not fully known, but transient conduction disturbances are common.
The authors performed aortic valve balloon dilatation on 10 closed-chest dogs with normal aortic valves, using a femoral cutdown approach and fluoroscopic guidance.
Four were done with a single 15 mm balloon catheter, and in the other 6 two 12 mm balloon catheters were used.
Balloons were inflated to 5 to 12 atms pressure with contrast solution.
After several inflations the dogs were sacrificed, the hearts removed and examined.
Gross examinations revealed subendocardial hemorrhage in the outflow tract in 5 of the 6 in which double balloons had been used.
Microscopically, all aortic valve areas showed hemorrhage, mostly in loose connective tissues of the valve leaflets.
The severity of injury appeared greater when two balloons had been used.
Histologic examination showed definite injury to the myocytes of the left bundle branch in all 6 of the double-ballooned dogs, but in none of those subjected to the single-balloon procedure.
During aortic valve dilation the only manifestation of conduction system injury was prolongation of the QRS complex in 3 of the 6 dogs in which a double-balloon catheter had been used.
The results suggest that electrocardiographic conduction disturbances observed in patients undergoing aortic valvuloplasty may be the result of direct injury of conduction tissue and may be more likely to occur when larger balloons are used.
| 22Pathological Conditions, Signs and Symptoms
|
Three-year outcomes for maintenance therapies in recurrent depression.
We conducted a randomized 3-year maintenance trial in 128 patients with recurrent depression who had responded to combined short-term and continuation treatment with imipramine hydrochloride and interpersonal psychotherapy.
A five-cell design was used to determine whether a maintenance form of interpersonal psychotherapy alone or in combination with medication could play a significant role in the prevention of recurrence.
A second question was whether maintaining antidepressant medication at the dosage used to treat the acute episode rather than decreasing to a "maintenance" dosage would provide prophylaxis superior to that observed in earlier trials in which a maintenance dosage strategy was employed.
Survival analysis demonstrated a highly significant prophylactic effect for active imipramine hydrochloride maintained at an average dose of 200 mg and a modest prophylactic effect for monthly interpersonal psychotherapy.
We conclude that active imipramine hydrochloride maintained at an average dose of 200 mg is an effective means of preventing recurrence and that monthly interpersonal psychotherapy serves to lengthen the time between episodes in patients not receiving active medication.
| 22Pathological Conditions, Signs and Symptoms
|
Delta sleep ratio. A biological correlate of early recurrence in unipolar affective disorder.
Slow wave sleep abnormalities have long been described in depression but were considered to be nonspecific indicators of psychopathology.
Computerized techniques, including amplitude frequency measures and spectral analyses, are permitting new approaches to the examination of delta sleep.
Early studies suggested that many depressed patients demonstrate lower delta wave intensity during the first non-rapid eye movement period than the second one.
This finding, prominent in middle-aged depressed patients, has led to an examination of the ratio between the first and second non-rapid eye movement periods.
This delta sleep measure seems to be a more robust predictor of recurrence than rapid eye movement latency.
Analysis of data on 74 patients in a long-term maintenance treatment study for a minimum of 24 months demonstrates that the delta sleep ratio can predict survival time following discontinuation of drug treatment.
Individuals with a high delta sleep ratio remain clinically remitted five times longer than those with a low delta sleep ratio.
| 22Pathological Conditions, Signs and Symptoms
|
Longitudinal study of diagnoses in children of women with unipolar and bipolar affective disorder.
School-age children of unipolar depressed, bipolar, chronically medically ill, or normal women were diagnosed every 6 months for up to 3 years.
Offspring of unipolar women had the highest rates of disorder at all evaluations, but children of bipolar and medically ill mothers also experienced significant rates of disorder.
Observing diagnoses from both past lifetime and prospective follow-up assessments, it appeared that most children who had diagnoses had onsets in preadolescence and continued a chronic or intermittent course of disorder.
Thus, risk to offspring of ill mothers is not transitory and indicates a pernicious course that commonly includes effective disorders alone or in combination with behavior and anxiety disorders.
| 22Pathological Conditions, Signs and Symptoms
|
Effect of chemodenervation on the cerebral vascular and microvascular response to hypoxia.
This study evaluated the effect of bilateral carotid chemodenervation on the cerebrovascular response to hypoxia in conscious rats.
Cerebral blood flow was measured using 4-iodo[N-methyl-14C]antipyrine, and the total and perfused microvasculature was studied by injection of fluorescein isothiocyanate dextran and alkaline phosphatase staining.
To maintain constant PCO2, hypoxia was achieved in chemoreceptor-intact rats by the use of 4% CO2-8% O2-88% N2 and in chemodenervated rats by the administration of 8% O2-92% N2.
Blood gas and hemodynamic parameters were similar in the two groups of rats.
Chemodenervation had no significant effect on either resting blood flow or the perfused microvasculature during normoxia.
A significant increase in cerebral blood flow (from 71 +/- 3 to 138 +/- 9 ml/min/100 g in control and from 91 +/- 5 to 127 +/- 7 ml/min/100 g in chemodenervated rats) and in the percent of cerebral arterioles and capillaries perfused occurred in both hypoxic control and chemodenervated rats.
In chemoreceptor-intact rats, the greatest increase in blood flow and in perfused microvasculature occurred in caudal structures (medulla and pons) in comparison with rostral structures (cortex, thalamus, and hypothalamus).
In chemodenervated rats, a similar increase in blood flow and perfused microvasculature occurred in all brain regions, with no regional differences.
Thus, chemodenervation did not affect the overall cerebral blood flow or the microvascular response to hypoxia; however, rostral-to-caudal regional differences in the hypoxic response were lost after chemodenervation.
| 22Pathological Conditions, Signs and Symptoms
|
Intrathoracic current flow during transthoracic defibrillation in dogs. Transcardiac current fraction.
To achieve transcardiac threshold current during transthoracic defibrillation, a considerably larger current must be delivered to the thorax to compensate for the shunting effect of the lungs, the thoracic cage, and other elements of the torso.
This shunting effect is thus an important determinant of transthoracic defibrillation threshold and can be quantified by the transcardiac current fraction (FC, the ratio of transcardiac to transthoracic threshold currents).
Previous estimates of FC have ranged from as low as 3% to as high as 45%.
The purpose of of this study was to quantify both FC and the major intrathoracic current pathways.
Transthoracic and intrathoracic voltages and currents were simultaneously measured during high-voltage transthoracic shocks in 20 dogs.
With correction factors determined from another set of 12 dogs, these raw data were corrected to compensate for field distortion caused by the presence of the intrathoracic electrodes, and the adjusted data were fit to a resistive network model.
The results showed that 82% of the transthoracic current was shunted by the thoracic cage, while 14% was shunted by the lungs.
The remaining 4% (FC) is the portion that passed through the heart.
There was good agreement between the two independent methods used to calculate FC.
Analysis based on the model indicated that FC was 3.7%, whereas FC determined by direct measurement with calibrated electrodes was 4.2%.
Therefore, the results of this study, in contrast to earlier estimates of FC, show that defibrillation in dogs is achieved by only 4% of the total transthoracic current.
| 22Pathological Conditions, Signs and Symptoms
|
Relation between transcardiac and transthoracic current during defibrillation in humans.
Conceptually, transthoracic defibrillation threshold current can be considered a function of at least two quantities.
It is directly proportional to the transcardiac threshold current and inversely proportional to the transcardiac current fraction (FC) or the ratio of transcardiac and transthoracic current.
Although experimental and theoretical estimates of FC have been as high as 45%, previous measurements in humans have not been made.
This study was designed to quantify FC in humans.
During intraoperative testing of the automatic implantable cardioverter defibrillator, transthoracic rescue shocks of 200-400 J were delivered when the device failed to defibrillate.
Simultaneous transthoracic voltage (VT) and transcardiac voltage (VC) between two implanted epicardial patch electrodes were measured.
The ratio, VC/VT, was 0.04 +/- 0.03 (mean +/- SD) in 10 patients.
In 16 dogs, a comparison was made between direct measurement of FC and VC/VT.
FC was determined with a specially designed electrode system, which was calibrated to account for field distortion introduced by the electrodes.
There was no significant difference between FC and VC/VT, which were both approximately 0.05, suggesting that VC/VT was statistically equivalent to FC.
The results of this study, therefore, indicate that during transthoracic defibrillation in humans, approximately 4% of transthoracic current traverses the heart.
This relatively small percentage of current results from the existence of parallel pathways, such as the thoracic cage and lungs, which shunt current around the heart.
| 22Pathological Conditions, Signs and Symptoms
|
The case for porous-coated hip implants. The femoral side.
A series of 1163 total hip arthroplasties (THAs) using porous-coated femoral components were roentgenographically assessed for implant fixation.
For 959 primary THAs followed from two to 12 years, the femoral revision rate was 1% and the ten-year survivorship rate was 96.4%; 150 young patients had a fixation failure incidence of only 1.3% at a mean follow-up period of 6.4 years; in 204 revision THAs, the femoral re-revision rate was 4% at a mean follow-up period of 53.4 months.
Failures were largely related to inadequate femoral canal filling.
Because of refinements in implant design and surgical techniques, a press fit of the implant is currently achieved in 94% of cases compared to 36% during the first five years.
Porous-coated femoral components have yielded results equivalent to those with cement in primary THAs.
Excellent results were observed in relatively young patients and patients with revisions.
| 22Pathological Conditions, Signs and Symptoms
|
Cardiac arrhythmias in critically ill patients: epidemiologic study
The general prevalence of cardiac arrhythmias in 2,820 consecutive patients was 78%, ranging from 44% in multiple trauma patients to 90% in primary cardiovascular patients.
Patients without recorded arrhythmias (22%, n = 621) were used as control subjects.
No clinical group was free from cardiac arrhythmias.
Atrial tachyarrhythmias had the highest prevalence in the population as a whole (28%) and in all clinical groups except multiple trauma.
Atrial fibrillation was the most common atrial arrhythmia (52%); ventricular arrhythmias followed.
Patients with atrial tachyarrhythmias, nodal rhythm ventricular bradyarrhythmias, and ventricular rapid rhythms had significantly (p less than .01) increased mortality rates (40%, 44%, 77%, and 51%, respectively) when compared with patients without arrhythmias (35%).
The relative risk of dying (RRD) of these clinical groups was increased by 1.16, 1.27, 2.20, and 1.47, respectively.
Patients with cardiorespiratory precipitating disease and any arrhythmia except atrial bradyarrhythmia had a mortality rate between 32% and 74%, significantly (p less than .05) different from that of patients within the same clinical groups without arrhythmias.
The RRD was increased by 1.67 to 3.40.
Septic patients with atrial tachyarrhythmia or nodal rhythm and neurologic patients with nodal or ventricular arrhythmias also had significantly (p less than .01 and .05, respectively) increased mortality and were at higher RRD (1.53 to 2.81).
Our data suggest that severe illness may be present in some clinical groups of critically ill patients with cardiac arrhythmias.
| 22Pathological Conditions, Signs and Symptoms
|
Reduction in bleeding after heart-lung transplantation. The importance of posterior mediastinal hemostasis.
To reduce perioperative hemorrhage following heart-lung transplantation, several technical modifications were introduced in June 1988 to secure better posterior mediastinal hemostasis.
The intraoperative and postoperative use of blood and blood products, as well as the chest tube drainage in the first 24 hours postoperatively, were compared in the seven patients operated on since June 1988 with the nine patients operated on before that date.
Significant (p less than 0.05) reductions were demonstrated in the intraoperative and postoperative transfusion of packed cells, in the postoperative administration of fresh frozen plasma, and in the chest tube drainage within the first 24 hours postoperatively.
The one-month and total hospital mortality rates were 6 percent and 12.5 percent, respectively.
It is concluded that newer techniques to obtain optimal posterior mediastinal hemostasis have significantly reduced blood loss following heart-lung transplantation in our experience and have contributed to our excellent early postoperative results.
| 22Pathological Conditions, Signs and Symptoms
|
Measurements of right ventricular volumes during fluid challenge.
The effects of fluid loading on RV function were studied in 41 acutely ill patients monitored with a modified pulmonary artery catheter equipped for measuring RVef.
Hemodynamic evaluation was performed before and after infusion of 300 ml of 4.5 percent albumin solution in 30 min.
Changes in SI did not correlate with Pra or Ppao but did with RVEDVI.
For the entire group, RVef was unchanged (27 +/- 9 vs 27 +/- 9 percent).
In the eight patients with an initial RVEDVI greater than 140 ml/m2, the fluid challenge increased Pra and Ppao and reduced LVSWI without any other significant effect.
There was no significant correlation between RVEDVI and Pra and only a weak correlation between RVESVI and Ppa.
However, there was a highly linear correlation between both RVEDVI and RVESVI and changes in RVEDVI and in RVESVI, suggesting that in the absence of severe pulmonary hypertension RV output is primarily dependent on RV preload.
| 22Pathological Conditions, Signs and Symptoms
|
Premenstrual syndromes defined by symptom-sets.
An analysis is made of the pattern of presenting premenstrual symptoms in randomly selected general practice patients from the Wellington region, New Zealand.
Participants, 1826 healthy women 16-54 years old whose characteristics were reasonably representative of the adult female population, were asked about their general, obstetrical and gynaecological health.
For the 1456 women who had menstruated within the last month or so, detailed questions were asked about the last menstrual cycle.
Each woman was assigned to one of seven premenstrual symptom sets.
Three groups had 'pure' symptoms, ie a predominant single symptom (breast tenderness, bloating or irritability).
Three groups had 'mixed' symptom-sets.
The largest of the 'mixed' groups was formed by the women who reported breast tenderness, bloating and irritability together with tension and depression.
Women in this group were most likely to rate their symptomatology as severe.
The last group contains a large number of women with miscellaneous symptoms.
Characteristics of these groups are outlined.
The study highlights the importance of distinguishing among premenstrual syndromes as this can foster more effective clinical management.
| 22Pathological Conditions, Signs and Symptoms
|
Liver transplantation: the shadow side.
For a relatively large number of patients with liver disease, a liver transplant does not always provide a successful solution.
What does confrontation with this modern technology mean for those involved? We interviewed 30 relatives of patients who had died after they had been turned down for a transplant, or during or shortly after a liver transplant operation performed in the Groningen Liver Transplant Programme.
Quantitative data were obtained by means of a questionnaire.
One-third of the respondents were of the opinion that the patient would have been better off if he/she had not entered the programme.
Over half found the loss more difficult to accept because the patient had been involved in the programme.
Nevertheless, many had the feeling of satisfaction that everything possible had been done.
However fruitful transplantation technology may be for a specific group of patients, it also involves undesirable side-effects which should be included in the careful judgement of this technology.
| 22Pathological Conditions, Signs and Symptoms
|
Muscle blood flow and muscle metabolism during exercise and heat stress.
The effect of heat stress on blood flow and metabolism in an exercising leg was studied in seven subjects walking uphill (12-17%) at 5 km/h on a treadmill for 90 min or until exhaustion.
The first 30 min of exercise were performed in a cool environment (18-21 degrees C); then subjects moved to an adjacent room at 40 degrees C and continued to exercise at the same speed and inclination for a further 60 min or to exhaustion, whichever occurred first.
The rate of O2 consumption, 2.6 l/min (1.8-3.3) (average from cool and hot conditions), corresponded to 55-77% of their individual maximums.
In the cool environment a steady state was reached at 30 min.
When the subjects were shifted to the hot room, the core temperature and heart rate started to rise and reached values greater than 39 degrees C and near-maximal values, respectively, at the termination of the exercise.
The leg blood flow (thermodilution method), femoral arteriovenous O2 difference, and consequently leg O2 consumption were unchanged in the hot compared with the cool condition.
There was no increase in release of lactate and no reduction in glucose and free net fatty acid uptake in the exercising leg in the heat.
Furthermore, the rate of glycogen utilization in the gastrocnemius muscle was not elevated in the hot environment.
There was a tendency for cardiac output to increase in the heat (mean 15.2 to 18.4 l/min), which may have contributed to the increase in skin circulation, together with a possible further reduction in flow to other vascular beds, because muscle blood flow was not reduced.
| 22Pathological Conditions, Signs and Symptoms
|
Stress adaptation and low-frequency impedance of rat lungs.
At transpulmonary pressures (Ptp) of 7-12 cmH2O, pressure-volume hysteresis of isolated cat lungs has been found to be 20-50% larger than predicted from their amount of stress adaptation (J.
Hildebrandt, J.
Appl.
Physiol.
28: 365-372, 1970).
This behavior is inconsistent with linear viscoelasticity and has been interpreted in terms of plastoelasticity.
We have reinvestigated this phenomenon in isolated lungs from 12 Wistar rats by measuring 1) the changes in Ptp after 0.5-ml step volume changes (initial Ptp of 5 cmH2O) and 2) their response to sinusoidal pressure forcing from 0.01 to 0.67 Hz (2 cmH2O peak to peak, mean Ptp of 6 cmH2O).
Stress adaptation curves were found to fit approximately Hildebrandt's logarithmic model [delta Ptp/delta V = A - B.log(t)] from 0.2 to 100 s, where delta V is the step volume change, A and B are coefficients, and t is time.
A and B averaged 1.06 +/- 0.11 and 0.173 +/- 0.019 cmH2O/ml, respectively, with minor differences between stress relaxation and stress recovery curves.
The response to sinusoidal forcing was characterized by the effective resistance (Re) and elastance (EL).
Re decreased from 2.48 +/- 0.41 cmH2O.ml-1.s at 0.01 Hz to 0.18 +/- 0.03 cmH2O.ml-1.s at 0.5 Hz, and EL increased from 0.99 +/- 0.10 to 1.26 +/- 0.20 cmH2O/ml on the same frequency range.
These data were analyzed with the frequency-domain version of the same model, complemented by a Newtonian resistance (R) to account for airway resistance: Re = R + B/ (9.2f) and EL = A + 0.25B + B .
log 2 pi f, where f is the frequency.
| 22Pathological Conditions, Signs and Symptoms
|
Control of total peripheral resistance during hyperthermia in rats.
To elucidate the effect of blood volume on the circulatory adjustment to heat stress, we studied alpha-chloralose-anesthetized rats at three levels of blood volume: normovolemia (NBV), hypervolemia (HBV; +32% plasma volume by isotonic albumin solution infusion), and hypovolemia (LBV; -16% plasma volume by furosemide administration).
Body surface heating was performed with an infrared lamp to raise arterial blood temperature (Tb) at the rate of approximately 0.1 degree C/min.
Before heating, central venous pressure (CVP) was significantly higher in HBV (0.41 +/- 0.25 mmHg) and lower in LBV (-1.44 +/- 0.22 mmHg) than in NBV (-0.41 +/- 0.10 mmHg).
The Tb at which CVP started to decrease was approximately 40 degrees C in HBV, approximately 41 degrees C in NBV, and approximately 42 degrees C in LBV, and it decreased by 1.53 +/- 0.14, 1.92 +/- 0.24, and 0.62 +/- 0.14 mmHg from 37 to 43 degrees C of Tb in HBV, NBV, and LBV, respectively.
Stroke volume was closely correlated with CVP, and this relationship was not affected by Tb.
Heart rate responses to the raised Tb were similar among the three groups.
Mean arterial pressure (MAP) was not affected by blood volume modification or CVP and was maintained at preheating (Tb 37 degrees C) level until Tb rose to 40 degrees C.
Above this Tb, MAP increased until Tb reached 43 degrees C (+30-40 mmHg) for all three groups.
Total peripheral resistance (TPR) was inversely correlated with CVP, and the slope of the linear relationship between TPR and CVP in LBV was three- to fourfold steeper than in NBV or HBV.
| 22Pathological Conditions, Signs and Symptoms
|
Modeling human performance in running.
This paper focuses on the characteristics of a model interpreting the effect of training on athletic performance.
The model theory is presented both mathematically and graphically.
In the model, a systematically quantified impulse of training produces dual responses: fitness and fatigue.
In the absence of training, both decay exponentially with time.
With repetitive training, these responses satisfy individual recurrence equations.
Fitness and fatigue are combined in a simple linear difference equation to predict performance levels appropriate to the intensity of training being undertaken.
Significant observed correlation of model-predicted performance with a measure of actual performance during both training and tapering provides validation of the model for athletes and nonathletes alike.
This enables specific model parameters to be estimated and can be used to optimize future training regimens for any individual.
| 22Pathological Conditions, Signs and Symptoms
|
Muscle maximal O2 uptake at constant O2 delivery with and without CO in the blood.
In the present study we investigated the effects of carboxyhemoglobinemia (HbCO) on muscle maximal O2 uptake (VO2max) during hypoxia.
O2 uptake (VO2) was measured in isolated in situ canine gastrocnemius (n = 12) working maximally (isometric twitch contractions at 5 Hz for 3 min).
The muscles were pump perfused at identical blood flow, arterial PO2 (PaO2) and total hemoglobin concentration [( Hb]) with blood containing either 1% (control) or 30% HbCO.
In both conditions PaO2 was set at 30 Torr, which produced the same arterial O2 contents, and muscle blood flow was set at 120 ml.100 g-1.min-1, so that O2 delivery in both conditions was the same.
To minimize CO diffusion into the tissues, perfusion with HbCO-containing blood was limited to the time of the contraction period.
VO2max was 8.8 +/- 0.6 (SE) ml.min-1.100 g-1 (n = 12) with hypoxemia alone and was reduced by 26% to 6.5 +/- 0.4 ml.min-1.100 g-1 when HbCO was present (n = 12; P less than 0.01).
In both cases, mean muscle effluent venous PO2 (PVO2) was the same (16 +/- 1 Torr).
Because PaO2 and PVO2 were the same for both conditions, the mean capillary PO2 (estimate of mean O2 driving pressure) was probably not much different for the two conditions, even though the O2 dissociation curve was shifted to the left by HbCO.
Consequently the blood-to-mitochondria O2 diffusive conductance was likely reduced by HbCO.
| 22Pathological Conditions, Signs and Symptoms
|
Mechanical deficit persists during long-term muscle hypertrophy.
Hypotheses were tested that the deficit in maximum isometric force normalized to muscle cross-sectional area (i.e., specific Po, N/cm2) of hypertrophied muscle would return to control value with time and that the rate and magnitude of adaptation of specific force would not differ between soleus and plantaris muscles.
Ablation operations of the gastrocnemius and plantaris muscles or the gastrocnemius and soleus muscles were done to induce hypertrophy of synergistic muscle left intact in female Wistar rats (n = 47) at 5 wk of age.
The hypertrophied soleus and plantaris muscles and control muscles from other age-matched rats (n = 22) were studied from days 30 to 240 thereafter.
Po was measured in vitro at 25 degrees C in oxygenated Krebs-Ringer bicarbonate.
Compared with control values, soleus muscle cross-sectional area increased 41-15% from days 30 to 240 after ablation, whereas Po increased 11 and 15% only at days 60 and 90.
Compared with control values, plantaris muscle cross-sectional area increased 52% at day 30, 40% from days 60 through 120, and 15% at day 240.
Plantaris muscle Po increased 25% from days 30 to 120 but at day 240 was not different from control value.
Changes in muscle architecture were negligible after ablation in both muscles.
Specific Po was depressed from 11 to 28% for both muscles at all times.
At no time after the ablation of synergistic muscle did the increased muscle cross-sectional area contribute fully to isometric force production.
| 22Pathological Conditions, Signs and Symptoms
|
Aggressive granulomatous lesions in cementless total hip arthroplasty.
We describe six patients with aggressive granulomatous lesions around cementless total hip prostheses.
Two patients previously had a cemented prosthesis in the same hip.
The Lord prosthesis was used in five patients, the PCA in one.
Both prostheses were made of chrome-cobalt alloy.
Pain on weight-bearing occurred on average 3.2 years after the cementless arthroplasty, and at that time radiography revealed aggressive granulomatosis around the proximal femoral stem and the acetabular component in five of the patients; one had a large solitary granuloma in the proximal femur.
Revision was performed on average 4.8 years after the cementless arthroplasty.
At that time all granulomas had grown large in size; while waiting for revision operation, two femoral stem components fractured.
All the granulomas showed a uniform histopathology, which included histiocytosis; the cause for these lesions was thought to be plastic debris from the acetabular socket.
| 22Pathological Conditions, Signs and Symptoms
|
Cup containment and orientation in cemented total hip arthroplasties.
We reviewed the radiographs of 864 Charnley and STH (Zimmer) cemented total hip arthroplasties with a mean follow-up of seven years (maximum 16 years).
Survivorship analysis was used to assess the correlation between radiographic performance and the bony containment or the coronal orientation of the acetabular cup.
The cup orientation and containment were interrelated; all vertically oriented cups were completely contained, whereas 25% of more horizontal cups were only partially contained.
Completely contained cups had significantly lower incidences of complete cement-bone radiolucency (p = 0.02) and of wear (p = 0.09).
Vertically oriented cups had a lower incidence of continuous radiolucency than neutrally oriented cups, but this was not statistically significant (p = 0.25).
Our results confirm the importance of complete bony containment, and also indicate that it is better to accept vertical orientation and obtain full bony coverage than to have a more horizontal orientation with partial containment.
| 22Pathological Conditions, Signs and Symptoms
|
Endoscopic control of upper gastrointestinal bleeding.
It has been estimated that gastrointestinal (GI) bleeding occurs in more than 100,000 patients with peptic ulcer disease each year.
In 75-80% of the cases, bleeding will be self-limited.
A major predictor of persistent or recurrent bleeding is the magnitude of blood loss before the initial evaluation.
Endoscopy has an important role in the evaluation of the patient with suspected or presumed upper GI bleeding.
Active bleeding at the time of the endoscopy correlates with the more likely probability of persistent bleeding, which carries a higher morbidity and mortality.
In addition, there has been continued interest in the finding of a visible vessel.
Although there is some controversy as to what a visible vessel actually is and how closely observations will agree about its recognition, there is general agreement that it is an important endoscopic finding and that it carries a high likelihood of rebleeding.
In addition to the finding of a visible vessel, many endoscopists feel that ulcers found in the posterior-inferior wall of the duodenal bulb and high on the lesser curve of the stomach should be considered in a separate category.
Owing to their proximity to large vessels, some feel that endoscopic management carries a greater risk because of the possibility of inducing bleeding.
A wide variety of endoscopic approaches are available for the therapy of upper GI bleeding.
It is convenient to divide these therapies into four categories: (a) topical, (b) injection, (c) mechanical, and (d) thermal.
Endoscopic therapy for bleeding ulcers has generally been performed with a high degree of safety.
| 22Pathological Conditions, Signs and Symptoms
|
Hemorrhage in mice produces alterations in pulmonary B cell repertoires.
Nosocomial pneumonia occurs frequently after hemorrhage and trauma and contributes to the increased incidence of morbidity and mortality after severe injury.
The production of secretory antibodies by mucosally associated B cells is an important component of pulmonary host defense mechanisms.
To determine the effects of hemorrhage on pulmonary B cell function, we examined hemorrhage induced alterations in pulmonary B cell repertoires.
There were no changes in the relative distribution of T or B cells among intraparenchymal pulmonary lymphocytes after blood loss.
Hemorrhage induced decreases of between 5- and 10-fold in the frequencies and numbers of pulmonary B cell clonal precursors specific for the bacterial Ag levan and Pseudomonas aeruginosa polysaccharide.
These decreases in numbers and frequencies of bacterial Ag-specific pulmonary B cell clonal precursors were present between 3 and 10 days after blood loss.
Similar decreases in numbers and frequencies were found among pulmonary clonal precursors specific for the autoantigen mouse transferrin, but not for the autoantigen dsDNA or the external antigens OVA and keyhole limpet hemocyanin.
These results demonstrate that hemorrhage produces marked alterations in pulmonary B cell repertoires, which may contribute to postinjury abnormalities in host defenses.
| 22Pathological Conditions, Signs and Symptoms
|
Adult height in boys and girls with untreated short stature and constitutional delay of growth and puberty: accuracy of five different methods of height prediction.
To determine how accurately several methods of height prediction estimate adult height, we compared height predictions calculated by the Bayley-Pinneau, Roche-Wainer-Thissen (RWT), target height, and Tanner-Whitehouse Mark I (TW-MI), and Mark II (TW-MII) methods with final adult height in 37 boys and 32 girls with short stature and constitutional delay of growth and puberty.
They were first seen at a chronologic age (mean +/- SD) of 14.80 +/- 1.70 years (boys) and 12.87 +/- 2.56 years (girls).
Adult height at 23.14 +/- 1.95 years and 21.05 +/- 2.02 years was 170.4 +/- 5.4 cm (boys) and 157.8 +/- 4.2 cm (girls), respectively, and thus within the lower range of normal.
Height predictions were calculated for the total group and for patients with parents of normal (group 1) as well as short stature (group 2).
For boys, the RWT method gave very accurate results, underestimating adult height by -0.6 cm for the total group.
The prediction errors for the other methods were -7.3 cm (TW-MI), -4.2 cm (TW-MII), and +3.1 cm (Bayley-Pinneau method) or +1.7 cm (target height).
For girls, no method was superior in estimating adult height.
The mean prediction error was -0.8 cm, -2.1 cm, and -1.8 cm with the Bayley-Pinneau, TW-MI, and TW-MII methods, respectively.
In contrast, adult height was overpredicted by +2.3 cm and +1.2 cm with the RWT and target height methods.
We conclude that patients with short stature and constitutional delay of growth and puberty reach an adult height in the lower range of normal.
Height prediction methods differ with respect to their accuracy and their tendency to overestimate or underestimate adult height.
| 22Pathological Conditions, Signs and Symptoms
|
Defective dystrophin in Duchenne and Becker dystrophy myotubes in cell culture.
We examined normal and dystrophic human myotubes in cell culture for expression of dystrophin, the protein product of the Duchenne muscular dystrophy locus.
Dystrophin levels in developing myotubes detected by Western blotting increased after 24 hours and reached maximum levels after 10 days in fusion medium.
We did not detect dystrophin in myotubes cultured from Duchenne myoblasts (7 cases).
Myotubes from a Becker muscular dystrophy patient's biopsy produced a lower molecular weight (approximately 408 kd) dystrophin, which was the same size in a whole muscle preparation from the same biopsy.
This 408-kd dystrophin was the expected size for this Becker patient whose DNA was deleted for exons 45-48 of the Duchenne gene.
This cell culture system will allow a detailed analysis of the effects of potential pharmacologic agents on steady-state dystrophin levels.
| 22Pathological Conditions, Signs and Symptoms
|
Psychosocial correlates of temporomandibular joint pain and dysfunction.
This study examines psychological differences between temporomandibular joint pain and dysfunction (TMJPD) patients, pain controls, and healthy controls.
Two hundred and two patients were classified, according to the diagnostic criteria of Eversole and Machado, as either myogenic facial pain (n = 42), internal derangement type I (n = 69), internal derangement type II (n = 85), or internal derangement type III (n = 6).
Patients completed the Basic Personality Inventory, the Illness Behavior Questionnaire, the Multidimensional Health Locus of Control, the Perceived Stress Scale, and the Ways of Coping Checklist.
Subjects also answered question pertaining to TMJPD symptomatology, including chronicity and severity.
After conservative treatment with simple jaw exercise and ultrasound, patients were contacted again at 5 months to complete follow-up questionnaires similar to those previously completed.
Comparison groups were comprised of 79 patients attending outpatient physiotherapy clinics for pain-related injuries not involving the temporomandibular joint and 71 pain-free, healthy students.
Data were analyzed using multivariate statistics.
The results indicate a significant relationship between pain intensity (and to some extent chronicity) and diverse measures of personality among the pain controls but not among the TMJPD patients.
This calls into question the validity of assuming individual pain disorders are subsets of a larger, homogenous pain disorder population.
TMJPD patients and pain controls score higher on hypochondriasis and anxiety than the pain-free controls but these elevations are not clinically significant.
The elevations decrease to normal levels in response to a positive treatment outcome.
There were no differences between the TMJPD patients and the pain controls on any of the measures.
These results suggests that TMJPD patients do not appear to be significantly different from other pain patients or healthy controls in personality type, response to illness, attitudes towards health care, or ways of coping with stress.
| 22Pathological Conditions, Signs and Symptoms
|
Transsynaptic degeneration in the superficial dorsal horn after sciatic nerve injury: effects of a chronic constriction injury, transection, and strychnine.
The lumbar and cervical spinal dorsal horns of adult rats with a chronic (8 days) constriction injury of the sciatic nerve on one side (and a sham operation on the other) were examined for signs of transsynaptic degeneration.
The incidence of neurons with signs of degeneration (pyknosis and hyperchromatosis; 'dark neurons') was significantly increased in the lumbar dorsal horn on both sides.
The ipsilateral lumbar increase was significantly greater than the contralateral increase.
There was no increase in the incidence of dark neurons in the cervical dorsal horns of the same rats.
The distribution of lumbar dark neurons was similar bilaterally.
The majority of the dark neurons were found in the sciatic nerve's territory in laminae I-II.
A second group of rats received the same surgery but in addition received a series of 7 daily subconvulsive doses of strychnine.
Dark neurons were again found bilaterally (with ipsilateral predominance) in the sciatic nerve's territory in lumbar laminae I-II, but the incidence was significantly greater than that found in the group that did not receive strychnine.
The same result was obtained in a third group of strychnine-treated rats when the sham operation was omitted.
Thus the appearance of contralateral dark neurons is not dependent on unintentional nerve damage created by the sham procedure.
An additional group of rats was sacrificed 8 days after receiving a unilateral sciatic nerve transection, a contralateral sham operation, and the 7 daily strychnine injections.
There was no increase in the incidence of dark neurons in any of these rats.
| 22Pathological Conditions, Signs and Symptoms
|
Filler DNA is associated with spontaneous deletions in maize.
We have determined the structure of five spontaneous deletions within the maize waxy (Wx) gene.
Of these, four were found in spontaneous wx mutants (wx-B, wx-B1, wx-B6, wx-C4) and include exon sequences; the fifth is restricted to an intron and represents a restriction fragment length polymorphism of a nonmutant allele (Wx-W23).
The deletions, which range in size from 60 to 980 base pairs (bp), cluster in a G+C-rich region of approximately 1000 bp that is capable of forming stable secondary structures.
Most striking is our finding that all of the alleles have DNA insertions (filler DNA) of 1-131 bp between the deletion endpoints.
For three of the five deletions, the filler DNA and sequences at the deletion termini appear to be derived from sequences near one deletion endpoint.
A previously reported spontaneous deletion of the maize bronze gene (bz-R) also contains filler DNA.
The association of filler DNA with maize deletion endpoints contrasts dramatically with the rarity of similar events in animal germ-line and bacterial mutations.
| 22Pathological Conditions, Signs and Symptoms
|
Site and strand specificity of UVB mutagenesis in the SUP4-o gene of yeast [published erratum appears in Proc Natl Acad Sci U S A 1991 Mar 1;88(5):2035]
DNA sequencing was used to characterize 208 mutations induced in the SUP4-o tRNA gene of the yeast Saccharomyces cerevisiae by UVB (285-320 nm) radiation.
The results were compared to those for an analysis of 211 SUP4-o mutations induced by 254-nm UVC light.
In each case, greater than 90% of the mutations were single base-pair changes but G.C----A.T transitions predominated and accounted for more of the mutations induced by UVB than UVC.
Double substitutions, single base-pair deletions, and more complex events were also recovered.
However, UVB induced 3-fold more tandem substitutions than UVC and nontandem double events were detected only after irradiation with UVC.
Virtually all induced substitutions occurred at sites where the pyrimidine of the base pair was part of a dipyrimidine sequence.
Although the site specificities were consistent with roles for cyclobutane dimers and pyrimidine-pyrimidone(6-4) lesions in mutation induction, preliminary photoreactivation data implicated cyclobutane dimers as the major form of premutational DNA damage for both agents.
Intriguingly, there was a preference for both UVB- and UVC-induced mutations to occur at sites where the dipyrimidine was on the transcribed strand.
| 22Pathological Conditions, Signs and Symptoms
|
Postoperative bile duct strictures.
Bile duct strictures are an uncommon but serious complication of primary operations on the gallbladder or biliary tree.
Most strictures occur as a result of injury to the bile duct during cholecystectomy.
In addition, strictures can occur at the site of previous biliary anastomoses for reconstruction of the biliary tree.
Most patients with benign bile duct strictures present soon after their initial operation; however, in some cases, presentation is delayed for years.
Cholangiography is essential for defining the anatomy of the biliary tree prior to management.
In many cases, nonoperative biliary drainage is useful to treat sepsis and biliary fistulas.
A number of alternatives exist for elective repair of bile duct strictures.
Experience would suggest, however, that a choledochojejunostomy or hepaticojejunostomy performed through a Roux-en-Y limb of jejunum is the preferable management in most cases.
Postoperative biliary stenting may be valuable in optimizing the results.
Nonoperative management by percutaneous transhepatic or endoscopic balloon dilatation has been reported to be successful in a number of small series.
Long-term results are limited, however.
Comparative data suggest that surgical repair for benign postoperative strictures is associated with fewer long-term problems and with similar overall morbidity and costs.
| 22Pathological Conditions, Signs and Symptoms
|
Fascinating rhythm: a primer on chaos theory and its application to cardiology.
Nonlinear dynamics is an exciting new way of looking at peculiarities that in the past have been ignored or explained away.
We have attempted to give a general introduction to the basics of the mathematics, applications to cardiology, and a brief review of the new tools needed to use the concepts of nonlinear mathematics.
The careful mathematical approach to problems in cardiac electrical dynamics and blood flow is opening a window on behaviors and mechanisms previously inaccessible.
| 22Pathological Conditions, Signs and Symptoms
|
Addition of clonidine enhances postoperative analgesia from epidural morphine: a double-blind study.
This study was undertaken to evaluate the analgesic effect of the combination of epidural morphine and clonidine versus epidural morphine alone in patients with postoperative pain.
A randomized double-blind design was used, and 91 patients scheduled for post-operative pain relief by epidural morphine were studied.
Patients received either a continuous epidural infusion of morphine and clonidine (group 1; n = 45) or morphine alone (group 2; n = 46) over the 72 h after major abdominal surgery.
In the first 24 h, the dose of morphine was 6 mg per 24 h; during the second 24 h, it was decreased to 4 mg per 24 h; and in the final 24 h, it was decreased to 2 mg per 24 h in both groups.
Group 1 patients received clonidine (450 micrograms) during each 24-h period.
Additional epidural bolus injections of 2 mg morphine and intravenous meperidine were given on demand.
The pain score, blood pressure, heart rate, respiratory rate, and relative forced vital capacity were measured at fixed times during the first 72 h after operation.
Total consumption of analgesics and side effects were recorded.
Although the total consumption of analgesics was significantly higher in group 2 (P less than 0.05), pain scores were lower in group 1 than group 2 during the entire observation period (P less than 0.05).
Epidural clonidine produced a significant decrease (P less than 0.05) in heart rate and blood pressure, whereas the respiratory rate was not affected.
Due to the better pain relief in group 1, the forced vital capacity was increased (P less than 0.05).
| 22Pathological Conditions, Signs and Symptoms
|
Influence of high-dose aprotinin treatment on blood loss and coagulation patterns in patients undergoing myocardial revascularization.
Intraoperative administration of the proteinase inhibitor aprotinin causes reduction in blood loss and homologous blood requirement in patients undergoing cardiac surgery.
To ascertain the blood-saving effect of aprotinin and to obtain further information about the mode of action, 40 patients undergoing primary myocardial revascularization were randomly assigned to receive either aprotinin or placebo treatment.
Aprotinin was given as a bolus of 2 x 10(6) kallikrein inactivator units (KIU) before surgery followed by a continuous infusion of 5 x 10(5) KIU/h during surgery.
Additionally, 2 x 10(6) KIU were added to the pump prime.
Strict criteria were used to obtain a homogeneous patient selection.
Total blood loss was reduced from 1,431 +/- 760 ml in the control group to 738 +/- 411 ml in the aprotinin group (P less than 0.05) and the homologous blood requirement from 838 +/- 963 ml to 163 +/- 308 ml (P less than 0.05).
In the control group, 2.3 +/- 2.2 U of homologous blood or blood products were given, and in the aprotinin group, 0.63 +/- 0.96 U were given (P less than 0.05).
Twenty-five percent of patients in the control group and 63% in the aprotinin group did not receive banked blood or homologous blood products.
The activated clotting time as an indicator of inhibition of the contact phase of coagulation was significantly increased before heparinization in the aprotinin group (141 +/- 13 s vs.
122 +/- 25 s) and remained significantly increased until heparin was neutralized after cardiopulmonary bypass (CPB).
| 22Pathological Conditions, Signs and Symptoms
|
Alterations in brain electrical activity may indicate the onset of malignant hyperthermia in swine.
The time course of changes in brain electrical activity during halothane anesthesia was examined in 12 malignant hyperthermia-susceptible (MHS) and 14 normal (nMHS) swine.
Power densities in selected frequency bands were calculated from the electroen-cephalogram (EEG).
EEG and systemic variables were determined over a period of 60 min after starting halothane (1% inspired).
Malignant hyperthermia (MH) was triggered in all susceptible pigs.
Initial changes in the EEG during development of MH consisted of a decrease in total power and a shift to lower frequencies (delta-theta activity) in all animals.
These EEG alterations were noted when there was an increase in heart rate, but other systemic variables were still normal.
EEG changes in all MHS animals started at an arterial oxygen tension (PaO2) greater than 90 mmHg and an arterial carbon dioxide tension (PaCO2) less than 50 mmHg.
In 5 MHS animals EEG became isoelectric at a PaO2 of 61-82 mmHg and a PaCO2 of 53-68 mmHg.
Mean arterial blood pressure at this time was 54-66 mmHg.
To determine the effects of hypoxia on the EEG in 7 nMHS animals, oxygen was decreased over a period of 45-60 min to 7% inspired.
In 7 other nMHS animals, hypercarbia was produced by admixture of carbon dioxide to the fresh gas supply to achieve incremental increases of PaCO2 to 110-120 mmHg.
Significant EEG changes during hypoxia comparable to those seen at the onset of MH were noted at a PaO2 below 40 mmHg and during hypercarbia at a PaCO2 greater than 68 mmHg.
| 22Pathological Conditions, Signs and Symptoms
|
Pilot study of nicardipine for acute ischemic stroke.
The author performed a pilot study of nicardipine (NC), a Ca(+)+ channel blocker, to study its dosing, toxicity, and possible efficacy for hemispheric cerebral infarction within 12 hours (mean 6.9 hr) of onset to determine the advisability of proceeding with a multi-centered controlled trial.
NC was administered IV (3 to 7 mg/hr) X 72 hours by titrating dose to mean arterial blood pressure (MABP not less than 10% of baseline), then orally X 30 days.
Forty-three patients have been entered; mean age 63 (range 34-89), 25 male and 18 female.
Only 3 had CT evidence of infarct on entry.
Results have shown improvement in a 100-point (pt) graded exam (40 pts at entry, 68 pts at 3 months).
Of 20 patients completing 3 months' evaluation, 17 improved and none worsened.
Sixteen out of 20 were at home and 8 had minimal or no impairment.
Mean Barthel's index was 72.
Mean maximal serum NC level was 75 ng/mL.
MABP decreased from 103 (entry) to 83 (72 hours).
A larger controlled study is warranted to determine the efficacy of NC for acute cerebral infarct.
| 22Pathological Conditions, Signs and Symptoms
|
Recognising failure to thrive in early childhood.
The maximum weight centile achieved by a child between 4 and 8 weeks of age was found to be a better predictor of the centile at 12 months than the birth weight centile.
Children whose weight deviated two or more major centiles below this maximum weight centile for a month or more showed significant anthropometric differences during the second year of life from those who showed no such deviation.
It is suggested that this leads to a logical and practical definition of failure to thrive.
| 22Pathological Conditions, Signs and Symptoms
|
Simultaneous 'dual system' rehabilitation in the treatment of facial paralysis.
Simultaneous dual system rehabilitation of facial paralysis involves using two independent reanimation techniques to optimize facial movement in both a quantitative and qualitative manner.
These techniques involve the use of nerve grafting or crossover procedures combined with a dynamic muscle transfer.
A group of 37 patients who underwent five different combinations of reanimation was analyzed.
The techniques were evaluated using a standard rating scheme for judging success of reanimation procedures.
The combination of a masseter muscle transfer to the lower region of the face and a cable graft of the upper facial nerve division appeared to offer excellent results in terms of independent motion of the upper and lower regions of the face and good eye closure, while allowing spontaneous mimetic function in 50% of cases.
The advantages and disadvantages of the other techniques are described.
The clinical situations in which these techniques have advantage over single reanimation techniques are outlined.
| 22Pathological Conditions, Signs and Symptoms
|
Comparison of i.m. ketorolac trometamol and morphine sulphate for pain relief after cholecystectomy.
I.m.
ketorolac trometamol 30 mg was compared with morphine sulphate 10 mg after cholecystectomy in a double-blind, multiple dose, randomized study of 100 patients.
Assessments of pain were made immediately after operation (day 1), and the next morning (day 2).
Pain intensity (verbal response score and visual analogue scale) was recorded before injection and then over a 6-h period.
Pain relief was assessed also.
The effect of ketorolac on operative blood loss and platelet function was examined.
Time to commencing oral intake and the duration of administration of i.v.
fluids were recorded.
Adverse events were noted.
Ketorolac produced significantly less analgesia than morphine on day 1, but on day 2 the two drugs produced a similar effect.
Blood loss was not increased by ketorolac, although platelet function was impaired.
Repeated i.m.
administration of ketorolac did not produce any serious adverse effects.
| 22Pathological Conditions, Signs and Symptoms
|
Preoperative piroxicam for postoperative analgesia in dental surgery.
Fifty patients were allocated randomly to receive placebo or piroxicam 40 mg, 2.5 h before surgical removal of lower third molars under general anaesthesia.
A significantly greater number of patients in the piroxicam group did not require opioid analgesia after operation (P less than 0.05).
The piroxicam group also required fewer doses of paracetamol in the first 24 h after recovery from anaesthesia (P less than 0.05), and the time from recovery to first postoperative analgesia was longer in those patients who had received piroxicam (P less than 0.05).
Piroxicam did not significantly prolong the duration of recovery from anaesthesia.
| 22Pathological Conditions, Signs and Symptoms
|
Effects of nimodipine on cerebral blood flow and neuropsychological outcome after cardiac surgery.
Thirty-five patients undergoing cardiac surgery requiring cardiopulmonary bypass (CPB) were allocated randomly in a prospective double-blind study to receive either nimodipine 0.5 micrograms kg-1 min-1 or placebo.
Cerebral blood flow (CBF) was measured during and immediately after CPB.
Neuropsychological tests were performed 6 months after surgery to determine any relationship between ischaemic damage and CBF and administration of nimodipine.
There were no differences in CBF between the nimodipine (n = 18) and placebo groups (n = 17).
Significant changes in neuropsychological tests were found in six patients tested 6 months after surgery but there were no conclusive signs of ischaemic damage.
The nimodipine-treated group performed better in tests of verbal fluency and visual retention, suggesting that some memory functions were preserved better in this group.
| 22Pathological Conditions, Signs and Symptoms
|
Functional and metabolic effects of bupivacaine and lignocaine in the rat heart-lung preparation.
We have examined the effects of bupivacaine and lignocaine on myocardial metabolism in the rat isolated heart-lung preparation.
Bupivacaine 1, 5 or 25 micrograms ml-1 or lignocaine 4, 20 or 100 micrograms ml-1 was administered 5 min after the start of perfusion.
Both bupivacaine 25 micrograms ml-1 and lignocaine 100 micrograms ml-1 reduced heart rate significantly.
Bupivacaine 25 micrograms ml-1 was associated with a higher incidence of arrhythmias than the other groups.
Three hearts in the bupivacaine 25 micrograms ml-1 group (n = 8) and two hearts in the lignocaine 100 micrograms ml-1 group (n = 8) failed (zero cardiac output) at the end of the experiment.
Although there were no significant differences in myocardial lactate and glycogen concentrations between groups, ATP content in the bupivacaine 25 micrograms ml-1 and lignocaine 100 micrograms ml-1 groups was significantly less than that in the control group.
The results suggest that myocardial depression and subsequent metabolic deterioration occurred with both the high doses of local anaesthetics; these findings do not account for the apparent increased cardiotoxicity of bupivacaine.
| 22Pathological Conditions, Signs and Symptoms
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.