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Effect of motion artefact on pulse oximeters: evaluation of four instruments and finger probes.
The ability of the Ohmeda 3700, Nellcor N200, Datex Satlite Plus and Simed S100 pulse oximeters to detect induced hypoxaemia in the presence of motion artefact was assessed, under conditions of controlled vibration using an industrial vibration facility.
Vibration at 4 Hz and 8 Hz induced increases in detection time for hypoxaemia and spurious decreases in the displayed SaO2 in some of the oximeters tested.
Finger-dependent differences in oximeter performance and pulse rate registration were noted especially in those oximeters without ECG linkage (Ohmeda 3700 and Simed S100).
Subsequently, eight different pulse oximeter finger probes were assessed for those characteristics that may predispose to motion artefact.
There were marked differences in the mass of the probes, the forces exerted on the test finger and in the force required to displace the probes from the subject's finger.
Differences in both the microprocessor programmes and the physical characteristics of the finger probes may explain the observed differences in function.
Similar studies should form part of the standard evaluation of new pulse oximeters.
| 22Pathological Conditions, Signs and Symptoms
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Diclofenac for day-care arthroscopy surgery: comparison with a standard opioid therapy.
Sixty unpremedicated patients presenting for day-care arthroscopy surgery were allocated randomly to receive diclofenac 1 mg kg-1 i.m., fentanyl 1 microgram kg-1 i.v.
or no analgesic during the course of anaesthesia.
Patients receiving fentanyl had slightly, although not significantly prolonged recovery times.
Patients receiving diclofenac had significantly improved postoperative visual analogue pain scores compared with patients receiving placebo medication (P less than 0.05).
With fentanyl, pain scores were reduced also, but the effect was not statistically significant.
Both fentanyl and diclofenac produced significant reduction in postoperative analgesic requirements (P less than 0.05).
We conclude that diclofenac 1 mg kg-1 i.m.
was an effective analgesic for arthroscopic procedures on the knee and is a useful alternative to opioids for day-care patients.
| 22Pathological Conditions, Signs and Symptoms
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Effect of indomethacin on pain relief after thoracotomy.
The effect of indomethacin on postoperative pain was studied in 60 adult patients undergoing thoracotomy in a prospective, randomized, double-blind manner.
Patients receiving indomethacin required significantly less opioid after operation and had significantly lower pain scores compared with the control group.
Pain on movement and on coughing were reduced also.
No major adverse effects were encountered.
| 22Pathological Conditions, Signs and Symptoms
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Late postoperative episodic and constant hypoxaemia and associated ECG abnormalities.
Twenty-two patients without cardiopulmonary disease and undergoing elective major abdominal surgery were monitored continuously with a Holter tape recorder and a pulse oximeter on one night before operation and the first two nights after operation (23:00 to 07:00), without oxygen therapy.
Mean heart rate increased 16 beat min-1 (P less than 0.001) and mean oxygen saturation (SaO2) decreased 2.6% (P less than 0.001) after operation.
Episodic oxygen desaturation to less than 80% occurred in four patients before operation, but in 13 patients after operation (P less than 0.05).
ECG abnormalities were observed in 10 patients before operation and in 16 patients after operation (ns).
Individual maximum ST depression was more pronounced after than before operation (P less than 0.05).
Episodic desaturation was related closely to tachycardia in six patients before operation and one patient after operation; before operation to atrioventricular block in one patient, and after operation to ST depression in two patients.
Mean SaO2 on the second night after operation correlated with total dose of opioid for pain relief (rs = -0.48; P less than 0.05), and postoperative decrease in SaO2 correlated with postoperative increase in heart rate (rs = -0.43; P less than 0.05).
No patient had postoperative cardiac complications indicating treatment.
| 22Pathological Conditions, Signs and Symptoms
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Nitrous oxide antagonizes CNS stimulation by laudanosine in mice.
We have investigated whether nitrous oxide antagonizes or augments the CNS stimulant action of laudanosine in mice by comparing the mean convulsive doses (CD50 (SE] of a control group and those following pretreatment with 65% nitrous oxide in oxygen for 20 and 180 min.
Nitrous oxide significantly increased CD50 from 46.8 (1.4) mg kg-1 of control to 57.3 (1.3) mg kg-1 at 20 min and 53.5 (1.7) mg kg-1 at 180 min.
The attenuation of the effect of nitrous oxide at 180 min, suggestive of possible partial drug tolerance, was not statistically significant.
These findings indicate that nitrous oxide antagonizes the CNS stimulating action of laudanosine.
| 22Pathological Conditions, Signs and Symptoms
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Profound digital collagen atrophy: a new cutaneous presentation of adrenal-dependent Cushing's syndrome.
A 59-year-old Caucasian housewife presented with a 2-year history of marked loss of tissue substance from the finger and toe pulps and the heel pads.
There was no clinical evidence or history of urticaria or other inflammatory change.
Investigations demonstrated a raised plasma cortisol secondary to a left adrenal adenoma.
Skin biopsies showed abnormalities of dermal collagen, but no evidence of elastin destruction.
This case presents an unusual variant of the cutaneous atrophy associated with Cushing's syndrome.
| 22Pathological Conditions, Signs and Symptoms
|
Home treatment for acute psychiatric illness
OBJECTIVE--To determine the factors influencing the successful outcome of community treatment for severe acute psychiatric illnesses that are traditionally treated in hospital.
DESIGN--All patients from a single electoral ward who were either admitted to hospital or treated at home over a two year period (1 October 1987 to 30 September 1989) were included in the study and their case notes audited.
The second year of the study is reported.
SETTING--Electoral ward of Sparkbrook, Birmingham.
SUBJECTS--99 Patients aged 16-65 with severe acute psychiatric illness.
RESULTS--65 Patients were managed by home treatment alone; 34 required admission to hospital.
The location of treatment was significantly (all p less than 0.05) influenced by social characteristics of the patients (marital state, age (in men), ethnicity, and living alone) and by characteristics of the referral (occurring out of hours; assessment taking place at hospital or police station).
DSM-III-R diagnosis was more weakly associated with outcome.
Violence during the episode was significantly related to admission, although deliberate self harm was not.
CONCLUSIONS--Home treatment is feasible for most patients with acute psychiatric illness.
A 24 hour on call assessment service increases the likelihood of success because admission is determined more strongly by social characteristics of the patient and the referral than by illness factors.
Admission will still be required for some patients.
A locally based mental health resource centre, a 24 hour on call service, an open referral system, and an active follow up policy increase the effectiveness of a home treatment service.
| 22Pathological Conditions, Signs and Symptoms
|
The importance of congenital hypertrophy of the retinal pigment epithelium in familial adenomatous polyposis.
We describe a family with familial adenomatous polyposis (FAP) and congenital hypertrophy of the retinal pigment epithelium (RPE).
Three of five members with FAP showed flat, well-demarcated, round to oval pigmented patches of congenital hypertrophy of the RPE.
We stress the importance of congenital hypertrophy of the RPE as a clinical marker in identifying patients with FAP since they are at risk for cancer.
| 22Pathological Conditions, Signs and Symptoms
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Systolic wall stress and ventricular arrhythmia: the role of acute change in blood pressure in the isolated working rat heart.
1.
The effect of a sudden acute change in blood pressure upon arrhythmia provocation has been studied in an isolated working heart model from the Wistar-Kyoto strain of rat.
Twenty-four hearts were studied.
2.
They were perfused with two different, modified, Krebs-Henseleit solutions at a fixed left atrial pressure.
3.
Acute changes in pressure, both increases and decreases, were arrhythmogenic.
Whilst ectopic activity was more predictably produced by pressure reductions, this consisted of simple ventricular ectopics only.
Pressure increases, in contrast, were capable of provoking more complex and sustained arrhythmias.
4.
The effect of pressure changes were highly dependent upon electrolyte concentrations in the perfusate.
Low potassium and magnesium concentrations increased the amount of arrhythmia provoked by pressure increases but tended to reduce that provoked by pressure reductions.
5.
We conclude that the direct effect of an acute change in pressure upon the myocardium is arrhythmogenic.
However, the myocardial response to a pressure change is interdependent upon prevailing electrolyte concentrations.
| 22Pathological Conditions, Signs and Symptoms
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Hypothalamic glucocorticoid implants prevent fetal ovine adrenocorticotropin secretion in response to stress.
We evaluated the role of the hypothalamic paraventricular nucleus (PVN) in control of ACTH secretion in fetal sheep.
Dexamethasone (DEX, 700 micrograms) (n = 6) or cholesterol (CHOL, 700 micrograms) (n = 5) implants were placed bilaterally 2 mm lateral to PVN of fetal sheep at 108 to 111 days of gestation (dga).
After 5 days recovery, fetuses were challenged with: 1) hypotension (50% drop of blood pressure), 2) hypoxemia (fall of greater than 5 mm Hg in fetal PaO2), and 3) corticotropin-releasing hormone (CRH) (10 micrograms iv, single injection to fetus).
Hypotension and hypoxemia were repeated after 125 dga.
Compared with CHOL, DEX fetuses had lower average concentrations of ACTH in plasma after hypotension [23 +/- 0.5 vs.
149 +/- 83.8 and 31 +/- 13.1 vs.
101 +/- 31.3 pg ml-1 at less than 125 and more than 125 dga, respectively (mean +/- SEM, P less than 0.05)] and during hypoxemia [11 +/- 1.6 vs.
292 +/- 152.8 and 33 +/- 9.4 vs.
304 +/- 91.3 pg ml-1 at less than 125 and more than 125 dga, respectively (P less than 0.05)].
DEX and CHOL responses to CRH at 122 to 127 dga (10 micrograms iv) were not different (38 +/- 23.9 vs.
92 +/- 26.7 pg ml-1, respectively).
Immunocytochemistry demonstrated that CRH was decreased in PVN and eliminated from median eminence in DEX, but not in CHOL fetuses.
Arginine vasopressin (AVP) immunostaining of PVN of DEX and CHOL fetuses was similar; however, unlike CHOL, DEX fetuses showed no AVP immunostaining of the external zone of median eminence.
These results show that, in fetal sheep, high concentrations of glucocorticoid near the fetal PVN prevent increases in plasma ACTH secretion seen in controls in response to hypotension and hypoxemia, and exert at least part of their effect at the level of the CRH- and AVP-producing neurons located in the PVN.
| 22Pathological Conditions, Signs and Symptoms
|
Loss of photosynthetic and chlororespiratory genes from the plastid genome of a parasitic flowering plant.
Photosynthesis is the hallmark of plant life and is the only plastid metabolic process known to be controlled by plastid genes.
The complete loss of photosynthetic ability, however, has occurred on several independent occasions in parasitic flowering plants.
Some of these plants are known to lack chlorophyll and certain photosynthetic enzymes, but it is not known to what extent changes have occurred in the genes encoding the photosynthetic apparatus or whether the plants even maintain a plastid genome.
Here we report that the nonphotosynthetic root parasite Epifagus virginiana has a plastid chromosome only 71 kilobases in size, far smaller than any previously characterized land plant plastid genome.
The Epifagus plastid genome has lost most, if not all, of the 30 or more chloroplast genes for photosynthesis and most of a large family of plastid genes, the ndh genes, whose products may be involved in a plastid respiratory chain.
The extensive changes in Epifagus plastid gene content must have occurred in a relatively short time (5-50 x 10(6) yr), because Striga asiatica, a related photosynthetic parasite, has a typical complement of chloroplast genes for photosynthesis and chlororespiration.
The plastid genome of Epifagus has retained transcribed ribosomal RNA and ribosomal protein genes, suggesting that it expresses one or more gene products for plastid functions not related to photosynthesis.
| 22Pathological Conditions, Signs and Symptoms
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Induction of RNA-stabilized DNA conformers by transcription of an immunoglobulin switch region
A deletion DNA rearrangement is associated with immunoglobulin class switching from IgM to IgG, IgA or IgE This recombination occurs in immunoglobulin switch regions, which are complex, highly repetitive regions of DNA.
As switch regions become transcriptionally active just before switch recombination, analysis of the behaviour of these sequences during transcription could elucidate the mechanism of switch recombination.
Here, we report that transcription of a supercoiled plasmid containing the murine IgA switch region (S alpha) leads to a loss of superhelical turns.
The resulting series of less supercoiled plasmids is stabilized by RNA-DNA hybrids formed by the nascent RNA transcripts, which remain base-paired with their DNA templates.
| 22Pathological Conditions, Signs and Symptoms
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Point mutation in the exoplasmic domain of the erythropoietin receptor resulting in hormone-independent activation and tumorigenicity.
The receptors for erythropoietin and other cytokines constitute a new superfamily.
They have no tyrosine-kinase or other enzyme motif and their signal-transducing mechanism is unclear.
Here we describe two classes of activating mutations in the erythropoietin receptor (EPOR).
A single point mutation in the exoplasmic domain enables it to induce hormone-independent cell growth and tumorigenesis after expression in nontumorigenic, interleukin-3-dependent haematopoietic cells.
A C-terminal truncation in the cytoplasmic domain of the EPOR renders the receptor hyperresponsive to erythropoietin, but is insufficient to induce hormone-independent growth or tumorigenicity.
The activating point mutation retards intracellular transport and turnover of the receptor.
These alterations in metabolism and tumorigenicity caused by the EPOR with activating point mutations are similar to those observed in erythropoietin-independent activation of the wild type EPOR by association with gp55, the Friend spleen focus-forming virus glycoprotein.
| 22Pathological Conditions, Signs and Symptoms
|
Current trends in suture fixation of posterior chamber intraocular lenses.
Corneal surgeons were surveyed with regard to their technique of suture fixation of posterior chamber intraocular lenses in the absence of posterior capsular support.
Fifty-nine percent of the 260 respondents stated they perform the procedure almost exclusively during penetrating keratoplasty.
Scleral fixation was marginally favored over iris fixation by these surgeons.
Most intraoperative problems reported were related to the relative technical difficulty of the procedure, although transient hemorrhage from the ciliary body was also mentioned.
Postoperative complications cited included mechanical problems involving the lens and iris, cystoid macular edema, glaucoma, and endophthalmitis.
| 22Pathological Conditions, Signs and Symptoms
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Differential regulation of human immunodeficiency viruses (HIVs): a specific regulatory element in HIV-2 responds to stimulation of the T-cell antigen receptor.
The human immunodeficiency viruses (HIVs) types 1 and 2 have similar genetic organization but differ significantly in nucleic acid sequence.
Although infection by either agent leads to symptoms of immunodeficiency, recent studies suggest potential differences in the time course and severity of these diseases.
In this report, the transcriptional regulation and induction of these retroviruses were analyzed.
We report that the regulation of HIV-2 differs from that of HIV-1: a distinct T-cell activation pathway, triggering of the CD3 component of the T-cell receptor complex, stimulates HIV-2 but not HIV-1 gene expression.
The response to T-cell receptor stimulation in HIV-2 is mediated partly by an upstream regulatory element, termed CD3R, which is recognized by a sequence-specific DNA binding protein, NF-CD3R.
Jurkat T leukemia cell lines containing HIV-2 provirus also showed increased viral replication after stimulation of the T-cell receptor complex, in contrast to HIV-1.
These findings suggest that transcriptional regulation and induction of HIV-2 differ from HIV-1 and raise the possibility that different cofactors contribute to the activation of HIV-1- and HIV-2-associated AIDS.
| 22Pathological Conditions, Signs and Symptoms
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A retroviral promoter is sufficient to convert proto-src to a transforming gene that is distinct from the src gene of Rous sarcoma virus.
The src genes of four natural isolates of avian sarcoma viruses differ from cellular proto-src in two genetic substitutions: the promoter of the cellular gene is replaced by a retroviral counterpart, and at least six codons from the 3' terminus are replaced by retroviral or heterologous cell-derived elements.
Since virus constructs with a complete proto-src coding region failed to transform avian cells but acquired transforming function by point mutations of various codons, it has been proposed that point mutation is sufficient to convert proto-src to a transforming gene.
However, promoter substitution is sufficient to convert two other proto-onc genes, proto-ras and proto-myc, to retroviral transforming genes.
In view of this, we have reexamined whether promoter substitution, point mutation, or both are necessary to convert proto-src into a retroviral transforming gene.
It was found that a recombinant virus (RpSV), in which the src gene of Rous sarcoma virus (RSV) was replaced by the complete coding region of proto-src, transformed quail and chicken embryo cells.
The oncogene of RpSV differs from the src gene of RSV in three genetic properties: (i) it is weaker--e.g., transformed cells are flatter; (ii) it is slower--e.g., focus formation takes 9 to 12 days compared to 4 days for RSV; and (iii) its host range is narrower than that of RSV--e.g., only subsets of heterogeneous embryo cells are transformed by RpSV even after weeks or months.
Replacement of the proto-src 3' terminus of RpSV by that of src from RSV generates a recombinant virus (RpvSV) that equals RSV in transforming function.
It is concluded that a retroviral promoter, naturally substituted via illegitimate recombination with retroviruses, is sufficient to convert at least three proto-onc genes, src, myc, and ras, to retroviral transforming genes.
| 22Pathological Conditions, Signs and Symptoms
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Molecular characterization of inherited medium-chain acyl-CoA dehydrogenase deficiency.
Deficiency of medium-chain acyl-CoA dehydrogenase (MCAD) is a common inherited defect in energy metabolism.
Characterization of the mRNA encoding MCAD in a Dutch MCAD-deficient patient revealed an A----G change at nucleotide position 985 of the MCAD mRNA coding region.
This point mutation results in the substitution of a glutamic acid for a lysine at amino acid position 304 of the mature protein.
The single base change was not found in any wild-type MCAD mRNAs.
A mutant allele-specific oligonucleotide probe was used in a hybridization analysis of amplified genomic DNA of MCAD-deficient family members, a carrier, and normal individuals.
The hybridization analysis specifically identified individuals who were heterozygotes or homozygotes.
In addition to the point mutation, a significant proportion of the index patient's MCAD mRNA contained a variety of deletions and insertions as a result of exon skipping and intron retention.
The missplicing occurred in multiple regions throughout the MCAD mRNA.
Analysis of the patient's MCAD gene in the regions where the missplicing occurred most frequently did not reveal a mutation in the splicing acceptor or donor sites.
Therefore, the molecular characterization of this family revealed a crucial point mutation in the MCAD gene and an unusual abnormality in MCAD pre-mRNA splicing.
| 22Pathological Conditions, Signs and Symptoms
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Transformed and nontransformed cells differ in stability and cell cycle regulation of a binding activity to the murine thymidine kinase promoter.
A DNA binding activity to an upstream region of the murine thymidine kinase gene is regulated differently in a transformed and nontransformed cell line pair.
Differences in regulation were observed (i) after serum levels were reduced, (ii) when serum levels were returned to initial high levels, and (iii) while protein synthesis was inhibited.
After reduction of serum levels, the binding activity was unstable in nontransformed BALB/c 3T3 clone A31 cells but was significantly more stable in benzo[a]pyrene-transformed BALB/c 3T3 cells.
After serum concentration was returned to high levels, the kinetic pattern of the binding activity differed between nontransformed and transformed cells.
While protein synthesis was inhibited, the binding activity was unstable in nontransformed cells and stable in transformed cells.
Partial inhibition of protein synthesis--a more stringent condition to test instability--prevented the induction of the binding activity in nontransformed cells.
Previously, the labile protein hypothesis set forth the criterion that a protein regulating the onset of DNA synthesis should be unstable in nontransformed cells and stable in transformed cells.
The DNA binding activity described here satisfies this criterion.
| 22Pathological Conditions, Signs and Symptoms
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Inactivation of human alpha-globin gene expression by a de novo deletion located upstream of the alpha-globin gene cluster.
Synthesis of normal human hemoglobin A, alpha 2 beta 2, is based upon balanced expression of genes in the alpha-globin gene cluster on chromosome 16 and the beta-globin gene cluster on chromosome 11.
Full levels of erythroid-specific activation of the beta-globin cluster depend on sequences located at a considerable distance 5' to the beta-globin gene, referred to as the locus-activating or dominant control region.
The existence of an analogous element(s) upstream of the alpha-globin cluster has been suggested from observations on naturally occurring deletions and experimental studies.
We have identified an individual with alpha-thalassemia in whom structurally normal alpha-globin genes have been inactivated in cis by a discrete de novo 35-kilobase deletion located approximately 30 kilobases 5' from the alpha-globin gene cluster.
We conclude that this deletion inactivates expression of the alpha-globin genes by removing one or more of the previously identified upstream regulatory sequences that are critical to expression of the alpha-globin genes.
| 22Pathological Conditions, Signs and Symptoms
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Prevalence and prognostic significance of exercise-induced ventricular arrhythmias after coronary artery bypass grafting.
Exercise-induced ventricular arrhythmias occur often after coronary artery bypass grafting (CABG), but their prognostic significance is unknown.
Two hundred patients examined by exercise electrocardiography and cardiac catheterization (including left ventriculography, bypass graft and native coronary artery angiography) before and 3 months after CABG were prospectively followed up.
Exercise-induced ventricular arrhythmias occurred more often after (49 of 200 patients, 24.5%) than before (32 of 200 patients, 16.0%) CABG (p less than 0.05).
There were no differences between the patients with and without ventricular arrhythmias in the prevalence of graft patency (79 vs 80%) or the postoperative ejection fraction (57 +/- 9 vs 57 +/- 12%).
Ten cardiac deaths occurred during the mean follow-up time of 61 +/- 19 months, 8 of which were witnessed sudden cardiac deaths.
All cardiac deaths occurred in patients who did not have exercise-induced ventricular arrhythmias after CABG.
The postoperative ejection fraction was lower in the cardiac death patients (42 +/- 16%) than in the survivors (58 +/- 10%) (p less than 0.01).
No other clinical or angiographic variable predicted the occurrence of cardiac death.
Thus, the prevalence of exercise-induced ventricular arrhythmias increases after CABG, but the occurrence of ventricular arrhythmias does not indicate an increased risk of cardiac death.
| 22Pathological Conditions, Signs and Symptoms
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Low-dose aspirin versus anticoagulants for prevention of coronary graft occlusion.
The prevention of graft occlusion by aspirin (100 mg/day) or heparin followed by phenprocoumon was investigated in a randomized trial in 235 patients after aortocoronary bypass operation.
Aspirin treatment started 24 hours before, and heparin 6 hours and phenprocoumon 2 days after surgery.
The results of the vein graft angiography and the clinical outcome 3 months postoperatively did not differ: 22% of 218 vein graft distal anastomoses in the aspirin group and 20% of 272 in the anticoagulant group were occluded.
At least 1 occluded distal anastomosis was present in 38% of 74 patients in the aspirin-treated group and in 39% of 86 in the anticoagulant group.
Worst-case analysis of all randomized patients showed graft occlusions, cardiovascular complications or lost to follow-up in 42% of 122 aspirin-treated patients compared with 41% of 113 patients treated with anticoagulants.
For grafts with endarterectomy the occlusion rate was lower in the aspirin (12% of 49) than in the anticoagulant (22% of 41) group (p less than or equal to 0.05).
Increased perioperative blood loss in the aspirin group (1,211 +/- 814 ml in the first 48 hours vs 874 +/- 818 ml in the anticoagulant group [p less than or equal to 0.001]) without a higher reoperation rate indicates effective platelet inhibition with low-dose aspirin.
Because occlusion rates were equal but high in these patients with advanced stage of coronary artery disease, a combination of low-dose aspirin and anticoagulation should be investigated to reduce graft occlusion rates further.
| 22Pathological Conditions, Signs and Symptoms
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Effect of electrocautery on wound healing in midline laparotomy incisions.
The effect of electrocautery on midline fascial wound healing was studied in 108 Sprague-Dawley rats.
Midline wound tensile strength was significantly reduced in fascia incised with the coagulation current compared with the cutting current or scalpel.
In addition, tissue necrosis and inflammation as well as adhesion formation between the incision and abdominal viscera were more extensive in animals with incisions made using coagulation current.
The results of the study indicate that the use of electrocautery coagulation current is associated with increased tissue damage and a significant reduction in the tensile strength of healing wounds.
The contribution of electrocautery to wound complications in patients needs further evaluation.
| 22Pathological Conditions, Signs and Symptoms
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Hypoxic events in the surgical intensive care unit.
An oxygen-monitoring protocol was established in the surgical intensive care unit (SICU) at the Denver General Hospital in July 1988.
A 3-month surveillance audit ending March 1989 prospectively documented 100 consecutive hypoxic events in 51 of 241 (21%) SICU patients.
These episodes occurred during mechanical ventilation in 46 patients, during spontaneous ventilation in 15 patients with artificial airways, and the remaining 39 occurred in nonintubated patients.
Hypoxemia was recognized by pulse oximetry in 59, arterial blood gas analysis in 24, mixed venous oximetry in 15, and transcutaneous oxygen monitoring in 2.
These events were due to problems with the ventilator or airway in 42, recent interventions in 21, new pulmonary process in 19, progression of underlying disease in 11, and unknown causes in 7.
Two thirds resulted from mechanical problems amenable to simple intervention; there were two adverse outcomes.
In conclusion, acute hypoxia is a frequent potentially morbid SICU event.
Advances in continuous oxygen monitoring permit early identification and thereby may limit adverse outcomes, but should not prompt an expensive diagnostic work-up.
| 22Pathological Conditions, Signs and Symptoms
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Flumazenil in ketamine and midazolam anaesthesia.
A double-blind, parallel group study using flumazenil and placebo was carried out to determine whether patients who received flumazenil would awake more quickly and whether this drug would reverse the protection conferred by midazolam on the psychic sequelae of ketamine.
Fifty female patients were studied.
The results showed that there was a significant reduction in awakening time (p = 0.02) and a very significant increase (p = 0.001) in the incidence of dreams in the flumazenil group.
| 22Pathological Conditions, Signs and Symptoms
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An evaluation of the Level 1 blood warmer series
The Level 1 blood warmer series comprises three infusion sets and two blood warmers of different power outputs.
All systems were found to be extremely efficient, with the larger 500 series capable of warming the equivalent of 80 units of blood an hour almost to body temperature.
| 22Pathological Conditions, Signs and Symptoms
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Was CEPOD right?
This retrospective study found that the long-term (greater than 6 months) postoperative survival in ASA 4E and 5E patients was 41% and 21% respectively, in 1986.
This supports the Confidential Enquiry into Peri-operative Deaths' recommendation that life-saving surgery should not be withheld from patients who present in so serious a condition that they are unlikely to survive surgery.
| 22Pathological Conditions, Signs and Symptoms
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The distribution of enkephalins in human carotid bodies showing cellular proliferation and chronic glomitis.
Human carotid bodies obtained at necropsy that showed prominence of either the sustentacular cell or the dark variant of chief cell or chronic carotid glomitis were studied by an immunogold labeling technique.
The peptides methionine and leucine enkephalin had a similar distribution to that found in the normal human carotid body.
They were localized prominently and predominantly in the dark and progenitor variants of chief (type I) cells.
The sustentacular (type II) cells showed no immunoreactivity for the enkephalins.
Cell counts on immunolabeled chief cells in cases of sustentacular cell hyperplasia and chronic carotid glomitis were found to be at the lower end of the normal range, whereas those in dark cell prominence occurred nearer the upper limit.
| 22Pathological Conditions, Signs and Symptoms
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In vivo nonthrombogenicity of heparin immobilized polymer surfaces.
The authors developed two different methods to immobilize heparin on polymer surfaces.
One method involves in situ heparin immobilization on a segmented polyurethane urea (Biomer) surface via hydrophilic poly(ethylene oxide) (PEO, Mn = 4,000) spacers.
The other method uses PEO/poly(dimethylsiloxane) (PDMS) block co-polymer and heparin covalently linked in a block co-polymer system (PEO-PDMS-Hep).
These surfaces have demonstrated high heparin bioactivity in vitro and excellent blood compatibility in in vitro-ex vivo experiments.
This report evaluates the long-term in vivo blood compatibility of these heparin immobilized surfaces.
Vascular grafts (6 mm ID, 7 cm in length) were fabricated with Biomer, and heparin was immobilized in situ with PEO spacers (B-PEO4K) and coated on their luminal surfaces with PEO-PDMS-Hep.
Biomer and PEO (Mn = 4,000) grafted Biomer (B-PEO4K) were used as controls.
The grafts were implanted in the abdominal aorta of dogs and retrieved at 3 months or when graft occlusion was suspected.
Retrieved grafts were evaluated with scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
TEM measured the thickness of the adsorbed protein layer on the surface and the protein distribution (albumin, fibrinogen, and IgG) visualized by an immunogold method.
All heparin immobilized grafts were patent at 3 months, whereas Biomer and B-PEO4K grafts occluded within 1 month.
SEM pictures of heparin immobilized surfaces after 3 months demonstrated minimal platelet adhesion and activation without detectable fibrin formation.
Heparin immobilized surfaces showed a thin protein layer (300-600 A) even after 3 months, with high concentrations of albumin and IgG and less fibrinogen.
| 22Pathological Conditions, Signs and Symptoms
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Monitoring platelet interactions with prosthetic graft implants in a canine model.
This study shows that prosthetic arterial grafts stimulate platelets for as long as 1 year after implantation in a canine model.
Carotid-to-distal aorta Dacron (DuPont, Wilmington, DE) grafts (0.8 x 50.0 cm) were tunneled subcutaneously over the right dorsal side, allowing for percutaneous arterial sampling.
Thromboxane B2 (TxB2) levels were evaluated at the proximal anastomosis (w), 5.0 (x), 25.0 (y), and 50.0 (z) cm distal from w, and platelet counts and mean platelet volumes were monitored at sites w and z.
TxB2 levels increased after blood entered the graft and progressively increased until the blood exited at the distal anastomosis.
Platelet counts did not significantly change across the graft.
Over time, systemic platelet counts decreased to approximately 50% of each dog's pregraft baseline levels and remained depressed over a 1 year period.
Mean platelet volumes peaked 1-3 weeks after implant and remained greater than pregraft levels.
Examination of the graft luminal surface showed a developed pseudointima characteristically similar to that which develops in mature human vascular grafts.
These results suggest that healed vascular grafts in canines continue to stimulate platelet release of TxB2, reduce systemic platelet counts, and increase mean platelet volumes over 1 year.
These data further suggest that platelets are stimulated by the graft and consumed.
| 22Pathological Conditions, Signs and Symptoms
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Another way of pumping blood with a rotary but noncentrifugal pump for an artificial heart.
This article describes an alternative mode of pumping blood inside the body.
The device is a non centrifugal, valveless, low speed rotary pump, electrically powered, based on Wankel engine principle.
The authors developed an implantable electrical actuator resulting in a compact, sealed motor-pump unit with electrical and magnetic components insulated from fluids.
The results in the flow curve and in the pumping action show some common points but also some basic differences compared to classical pulsatile pumps or centrifugal pumps.
The blood coming from the atrium follows a continuous movement without any stop flow but with variations creating pulsatility.
Ejection and filling of the pump are simultaneous.
It is always an active filling.
Hydraulic efficiency depends on clearance in the pumping chamber and outlet port pressure.
A 60 cc device allows flows up to 8-9 liters.
The implantable motor is cyclindrical in shape, has a moderate weight (490 grams) and presents a good efficiency (32% for a rotary speed of 90 rpm against a mean aortic pressure of 150 mm of Hg).
The authors conclude that their device could be proposed after further experimental studies, as an LVAD for shortterm assistance with a good promise for permanent application.
| 22Pathological Conditions, Signs and Symptoms
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Improved biocompatibility by postfixation treatment of aldehyde fixed bovine pericardium.
Long-standing release of locally cytotoxic aldehyde concentrations is responsible for lack of spontaneous endothelialization and increased calcification of glutaraldehyde fixed bovine pericardium.
Postfixation treatment with amino acids made in vitro endothelialization of bioprosthetic heart valves possible.
Such treated pericardium calcified significantly less (13 +/- 4 micrograms/mg dry weight) than did conventionally processed pericardium (114 +/- 25 micrograms/mg) after 63 days of subcutaneous implantation in rats.
To test the ability for spontaneous in vivo endothelialization, 5 sheep had 6 mm grafts made from postfixation treated pericardium (PTP) implanted into the carotid artery, compared to PTFE grafts on the contralateral side, which spontaneously endothelialize in animal models.
In a pregnant animal, both grafts occluded.
All remaining pericardial grafts remained patent, but one additional PTFE graft occluded and another one was stenosed.
The area covered with red thrombus was significantly smaller in the PTP grafts (3.05 +/- 3.9%) than in the PTFE grafts 42 +/- 14% (p = 0.0036); TEM and SEM showed endothelial cells growing directly on the PTP, but only on myofibroblasts in PTFE grafts.
Postfixation treatment of glutaraldehyde fixed pericardium aids spontaneous endothelialization and decreases tissue calcification.
| 22Pathological Conditions, Signs and Symptoms
|
Acellular matrix allograft small caliber vascular prostheses.
We have developed an acellular matrix vascular prosthesis (AMVP) made by detergent and enzymatic extraction of natural arteries, yielding a tissue framework of collagen and elastin from the original vessel, with preservation of the natural basement membrane at the blood flow surface.
These biografts have excellent handling characteristics and suturability, as well as low thromboreactivity.
Whole vessel static testing of circumferential compliance (8.9 +/- 1 [SEM] X 10(-2)% mmHg at 100 mmHg) revealed behavior virtually identical to the paired natural vessel from which each AMVP was derived in nine canine carotid arteries.
We implanted 16 canine-origin AMVPs into nine dogs (12 femoral and three carotid arteries, and one infrarenal aorta) with no antithrombotic drugs.
Angiographic patency was maintained in 15 of 16 (one occlusion within 3 days) for follow-up from 3 days to 6 years, with no aneurysm formation in three AMVP at over 4 1/2 years.
Explant analysis revealed preservation of AMVP elastica and collagen with no inflammation or dystropic calcification of the AMVP, and almost total thrombus free flow surfaces.
These results suggest that allograft AMVPs could achieve long-term patency equivalent to saphenous veins.
| 22Pathological Conditions, Signs and Symptoms
|
Development of a soft, pliable, slow heparin release venous graft.
To prevent their collapse, a certain amount of stiffness is generally required for prosthetic venous grafts, so EPTFE grafts have been used.
However, the native vein is pliable without any stiffness.
We developed a soft and pliable graft that can maintain patency of the lumen because of its compliance.
Fresh porcine ureter was incubated in a ficin solution to remove cell components and noncollagenous proteins.
One percent protamine sulfate solution was injected into the ureter lumen to impregnate the inner surface.
The ureter was then crosslinked with a 1% glutaraldehyde solution, dipped into a 1% heparin solution for 5 hours, and rinsed with distilled water.
This procedure made the ureter very soft and pliable, and also conferred antithrombogenicity to the graft by heparinization.
The grafts were implanted into the posterior vena cavae of 20 dogs and were removed from 1 to 878 days after implantation.
Eighteen grafts were patent, but two grafts were occluded at the anastomotic site at 218 and 107 days, respectively.
As a control experiment, nonheparinized grafts were implanted into 15 dogs; all were occluded with fresh thrombi.
All the patent grafts kept their original elasticity, which allowed them to heave in unison with the heartbeat, and were similar in appearance to the native vena cava.
Heparinization was effective in preventing thrombus formation.
These results indicate that this type of graft is an ideal prosthesis as a venous graft, having physiologic properties such as compliance and antithrombogenicity.
| 22Pathological Conditions, Signs and Symptoms
|
Endothelialization of vascular prostheses by transplantation of venous tissue fragments.
A method to accelerate the endothelialization of vascular prostheses by seeding venous tissue fragments was developed.
A piece of peripheral vein was obtained, chopped into small fragments, and stirred into 20 ml of saline, making a tissue suspension.
This suspension was sieved through the wall of a highly porous vascular prosthesis (water porosity: 3,600-4,000).
The prostheses, (7 mm ID and 5.7 cm in length) seeded with tissue fragments, were implanted into the thoracic descending aortae of 20 dogs, and were removed from 1 to 371 days after implantation.
Ten prostheses, preclotted with fresh blood, were used as controls.
In the seeded grafts, an infinite number of endothelial cells migrated and proliferated from the fragments.
These had produced numerous capillaries by 5 days after implantation that had reached and opened onto the luminal surface of the prosthesis.
From these openings, numerous endothelial cells spread out and formed colonies.
With the increase in the size of the colonies, the inner surface was completely endothelialized within 5 weeks.
This quick neointimal formation by seeding venous tissue fragments might be applicable to several artificial organs.
| 22Pathological Conditions, Signs and Symptoms
|
Functional heart replacement with the spindle pump: first results.
The spindle pump is a nonpulsatile blood pump with a double function, i.e., it works centrifugally and represses simultaneously.
The first experiences with this type of pump used as a biventricular assist device in four short-term animal experiments (up to 13 hours) are described.
It can be demonstrated that in cases of a normally beating heart, this BVAD decompresses both ventricles by 60-70%, while the aortic pressure is slightly increased; on the other hand, in case of ventricular fibrillation, the BVAD with two spindle pumps maintained the entire circulation, at an arterial pressure between 80 and 90 mmHg with a flow volume between 3.5 and 4 L/min.
| 22Pathological Conditions, Signs and Symptoms
|
Maintenance of circulation during ventricular fibrillation with the simultaneous use of two "counterpulsation" devices.
Two valveless, single orifice counterpulsation devices, with pumping stroke volumes of 65 ml each, were implanted on the ascending aorta and pulmonary artery of seven open chest anesthetized dogs.
After completion of the preparation, ventricular fibrillation was induced.
The devices were synchronized to pump simultaneously at a rate of 85-100 bpm.
The combined use of the counterpulsation devices provided maximal aortic pressure of 111.4 +/- 25.1 mmHg during ventricular fibrillation for a period of 15-60 min.
The mean left ventricular pressure was 17.7 +/- 4.4 mmHg, and the cardiac index 64.5 +/- 23.6 ml/kg/min.
Cardioversion of ventricular fibrillation to sinus rhythm restored normal hemodynamics.
The counterpulsation device implanted on the ascending aorta was not able to maintain circulation for more than 5 min after the induction of ventricular fibrillation, if used alone.
In conclusion, the use of two counterpulsation devices implanted on the ascending aorta and pulmonary artery was able to maintain circulation in experimental animals during ventricular fibrillation.
| 22Pathological Conditions, Signs and Symptoms
|
Long-term echocardiographic follow-up of patients with a tricuspid bioprosthesis.
To clarify the long-term results of bioprosthetic valve function in the tricuspid position, 29 consecutive patients who underwent tricuspid valve replacement (TVR) were evaluated.
There were 20 girls/women and 9 boys/men, with ages ranging from 6 to 61 years (mean 41.4 years).
The bioprosthetic valves included Hancock in 2, and Carpentier-Edwards in 27.
The follow-up period ranged from 32 to 145 months (mean 89 months).
Regurgitant flow of the tricuspid bioprosthesis was studied by color Doppler echocardiography.
Peak velocity (Vp) and pressure half time (PHT) were measured by continuous wave Doppler echocardiography.
Operative mortality was 13.7% (4/29), with the actuarial survival rate, including operative deaths, 75% at 10 years.
Valve thrombosis developed in one patient 4 years after TVR.
Color Doppler showed regurgitation in 7 of the 20 patients who were completely followed up, but they were all asymptomatic and required no special intervention.
Cusp tear or calcification requiring reoperation was not observed in this study, including 8 patients younger than 35 years of age.
The Vp was significantly slower, and PHT was significantly prolonged, in the tricuspid rather than the mitral position.
These data demonstrate that bioprosthetic valves in the tricuspid position can be used safely.
Doppler examination should be performed taking these different flow dynamics into account.
| 22Pathological Conditions, Signs and Symptoms
|
Effects of prostaglandin I2, superoxide dismutase, and catalase on ischemia-reperfusion injury in liver transplantation.
This study evaluated the effects of a prostaglandin I2 analogue (aPGI2), superoxide dismutase (SOD), and catalase (CAT) on hepatic injury after warm ischemia and reperfusion in terms of survival, mitochondrial function, serum enzymes, and histology.
Hepatic ischemia was created in rats by clamping the hepatoduodenal ligament for 90 min with splenofemoral bypass.
Reperfusion was induced by unclamping the vessels and disconnecting the splenofemoral bypass.
Then aPGI2 (350 ng/kg/min) was infused for 60 min just before hepatic ischemia, and SOD and CAT (5,000 units/kg each) were administered immediately before the start of reperfusion.
Serum enzyme and mitochondrial function assessments of livers were made just after ischemia, and after 2 hr of reperfusion.
Survival rate was also assessed in a separate group of rats.
Liver enzymes such as SGOT, SGPT, and LDH showed no correlation to liver viability.
The administration of aPGI2 alone showed no effect on ischemically injured mitochondria; however, the free radical scavengers (SOD, CAT), in combination with aPGI2, showed significant improvement of mitochondrial function together with extension of survival.
The ultrastructure of hepatocytes was better preserved in the treated groups.
These agents improved the viability of ischemic-reperfused injured livers.
| 22Pathological Conditions, Signs and Symptoms
|
Comparison of Delphin and BioMedicus pumps.
There is an increasing use of centrifugal pump systems for cardiopulmonary bypass (CPB) and circulatory assistance.
The BioMedicus and Delphin centrifugal pump systems were tested in two side-by-side, identical in vitro flow loops for blood trauma and flow probe accuracy.
Blood parameters tested were hemoglobin, hematocrit, lactate dehydrogenase, free plasma hemoglobin, and platelet counts.
The Delphin pump demonstrated significant increases in plasma hemoglobin levels at the three flow rates tested: 2 L/min (p less than 0.05), 4 L/min (p less than 0.005), and 6 L/min (p less than 0.05).
After 4 hr of pumping, the drop in platelet counts was significantly greater in the BioMedicus loop as compared with the Delphin loop (p less than 0.05) at the 2 L/min and 4 L/min flow rates; however, platelet levels remained within normal ranges in both systems.
At 6 L/min, no statistical difference in platelet counts was noted.
The flow probe readings were found to deviate by as much as 58% of stopwatch timed flow rate comparisons at low flow rates, but improved to within 10% or better at 6 L/min.
| 22Pathological Conditions, Signs and Symptoms
|
Development of a small caliber biologic vascular graft: evaluation of its antithrombogenicity and the early healing process.
The authors previously showed that a small caliber xenograft using our crosslinking technique was applicable to aortocoronary bypass grafting.
In this study of the graft, the antithrombogenicity and healing process was evaluated at an early stage after implantation.
Fresh sheep carotid artery (3mm ID) was obtained and cross-linked with polyepoxy compounds, and then used as a small caliber vascular graft.
The graft was white and soft.
Six cm segments of the graft were implanted into the carotid arteries bilaterally in nine dogs.
Sodium heparin was given during the surgery, but no anticoagulant was used postoperatively.
Fifteen grafts from eight dogs were removed from 1 hr to 30 days after implantation, and 13 of 15 grafts were found to be patent.
Two grafts, one at 3 days, and the other at 14 days, were occluded.
The anastomotic area of the occluded grafts felt hard when touched from the outside.
In one dog, the grafts were shown angiographically to be patent at 14 days after implantation, and this dog was kept for long-term observation.
Macroscopically, no thrombus was observed on any of the patent grafts.
Microscopically, the inner surface near the anastomotic lines was covered with endothelial cells, and infiltration of fibroblasts was observed from the outside 7 days after implantation.
No foreign body reactions were seen around the graft.
After 30 days of implantation, a thin layer of plasma protein at the middle of the graft was observed by scanning electron microscopy (SEM).
From these observations, it was concluded that the grafts exhibited satisfactory early antithrombogenicity and healing after implantation.
| 22Pathological Conditions, Signs and Symptoms
|
Proliferation and substrate effects on endothelial cell thrombogenicity.
The effects of the cellular differentiation status and the adhesive-substrate on endothelial cell function in cell culture were measured with an enzyme based assay of surface thrombogenicity.
A solid plastic, microporous polymeric, and fibronectin (FN) treated microporous polymeric were used as substrates for growth of endothelial cells.
The microporous and FN treated synthetic substrates have been shown to aid in the induction of cellular differentiation mechanisms.
Cells were studied under proliferative and nonproliferative growth conditions.
The thrombogenicity of the surface created by the endothelial cell monolayers under various experimental conditions was determined using an enzyme based assay of fibrin deposition.
Actively proliferating cells on the solid plastic substrate produced the most thrombogenic surface, while confluent endothelial cell monolayers grown on FN treated microporous substrate were the least thrombogenic surfaces.
These data suggest that endothelial cell surface thrombogenicity is under substrate control, and also related to the cellular differentiation status.
These findings are being used to design a novel approach to the small diameter synthetic vascular graft problem.
| 22Pathological Conditions, Signs and Symptoms
|
Effect of complement and arachidonic acid pathway inhibition on white blood cell count and deposition on vascular grafts.
To determine the role of complement and arachidonic acid metabolites in the decrease in peripheral white blood cell count (pWBC) observed with graft implantation, Dacron aortic grafts were implanted in control rabbits (Group I, n = 13), or rabbits pretreated with cobra venom factor (80 U/kg) to deplete complement (Group II, n = 13), indomethacin (2.5 mg/kg) to inhibit cyclooxygenase (Group III, n = 7), or diethylcarbamazine (DEC, 90 mg/kg) to inhibit leukotriene synthesis (Group IV, n = 7).
pWBC was measured 15 min and 1 hr after graft implantation.
After graft removal, the WBC count on grafts (gWBC) was determined by light microscopy (LM) and scanning electron microscopy (SEM).
One hr after graft implantation, pWBC decreased significantly in Groups I-IV to 46%, 52%, 40%, and 45% of preoperative pWBC, respectively.
There was no significant difference among the groups.
LM revealed gWBC per 63x field of 8.0, 12.3, 5.8, and 6.8 in Groups I-IV, respectively.
Similarly, SEM showed gWBC per 2000x field of 2.5, 5.6, 0.7, and 1.5 in Groups I-IV, respectively.
SEM gWBC was significantly greater in Group II than I (p less than 0.01), and significantly less in Group III than I (p less than 0.05).
Results suggested that complement and arachidonic acid pathways alone do not affect the fall in pWBC, but may influence gWBC.
| 22Pathological Conditions, Signs and Symptoms
|
Total perinatal wastage. A clarification of priorities.
The pregnancy outcome of 16,971 women carrying 17,352 living fetuses after 16 weeks gestation was studied.
As well as recording perinatal deaths, all losses before 28 weeks and up to one year after delivery were recorded to give a total perinatal wastage rate of 21.6 per 1000 fetuses alive at 16 weeks compared with a perinatal mortality rate (stillbirths plus early neonatal deaths) of 7.8 per 1000 births.
All deaths were then classified according to pathological sub-groups.
The concept of auditing perinatal care using perinatal mortality was then compared with that using total perinatal wastage.
| 22Pathological Conditions, Signs and Symptoms
|
Magnetic resonance imaging in idiopathic retroperitoneal fibrosis: measurement of T1 relaxation time.
Magnetic resonance imaging at 0.08 Tesla was performed in nine patients with proven idiopathic retroperitoneal fibrosis.
A total of 11 scans was performed.
Three patients were scanned before diagnosis; one of these also had two follow-up scans.
A further six patients were scanned a variable time after diagnosis and treatment.
On each scan, a periaortic soft-tissue mass was readily identified, the distribution corresponding to that seen on computed tomography.
There was no difference in the mean T1 relaxation time of the mass between patients scanned before diagnosis and those scanned after treatment.
However, the patient followed with serial scans showed a progressive reduction in the T1 value of the mass with time.
Comparison with results obtained in patients with lymphoma suggests that the T1 values in retroperitoneal fibrosis are lower than in lymphoma, particularly non-Hodgkin's lymphoma.
| 22Pathological Conditions, Signs and Symptoms
|
Development and reversibility of T lymphocyte dysfunction in experimental obstructive jaundice
This study evaluates the effect of experimental biliary obstruction by bile duct ligation (BDL) and biliary drainage on cell-mediated immunity in Wistar rats.
Immune status has been assessed by a mitogen stimulation test of T lymphocytes with phytohaemagglutinin.
Animals were followed for up to 35 days after BDL.
Regression analysis showed a significant negative correlation between lymphocyte function and the period of jaundice (correlation coefficient -0.57, P less than 0.001).
Following BDL for 21 days, groups of animals had internal biliary drainage for 7, 14 and 28 days, and external drainage for 14 days.
Compared with obstructed animals, 14 days internal drainage was required to improve lymphocyte function (P less than 0.05).
Animals which had 14 days of external drainage had significantly lower lymphocyte stimulation than internal drainage animals (P less than 0.05).
The results demonstrate that obstructive jaundice produces a progressive reduction of T lymphocyte function.
This can be reversed by biliary drainage, internal drainage being more effective than external drainage.
| 22Pathological Conditions, Signs and Symptoms
|
Assessment of the biliary tract after liver transplantation: T tube cholangiography or IODIDA scanning.
Biliary tract obstruction or anastomotic leakage are common problems following liver transplantation.
In a sequential study, 31 patients with a liver transplant were investigated by 99mTc-IODIDA (IODIDA) scanning and T tube cholangiography (TTC) and the results were compared with clinical outcome.
Seven patients had an extrahepatic biliary obstruction and one patient had a biliary leak.
In the detection of biliary complications TTC and IODIDA scanning were similar in terms of sensitivity (63 per cent for both) but TTC had a better specificity (79 per cent versus 60 per cent) and accuracy (74 per cent versus 60 per cent) than IODIDA scanning.
When liver function was taken into account, the diagnostic efficacy of both tests in patients with bilirubin levels of less than 200 mumol/l was similar.
With levels greater than 200 mumol/l there was a greater number of false positive results with IODIDA scanning (12 per cent versus 54 per cent).
The only significant biliary leak was clearly detected by TTC but not IODIDA scanning.
TTC remains the more effective way of evaluating the biliary tract after transplantation.
IODIDA scanning has limited value when bilirubin levels are elevated, but may provide additional information about blood supply, hepatocyte function and intrahepatic cholestasis.
| 22Pathological Conditions, Signs and Symptoms
|
Patterns of dyspepsia in patients with no clinical evidence of organic diseases.
We studied 2000 dyspeptic patients with no obvious signs of organic disease at their first examination, in order to (1) verify how many diagnoses of idiopathic dyspepsia had really been made after exhaustive diagnostic procedures and (2) evaluate the diagnostic power of the symptoms in distinguishing organic from idiopathic dyspepsia.
This latter was considered only when no structural abnormalities were found.
In all the other cases, a distinction was made between "related" and "associated" organic dyspepsia according to whether or not there was a certain relationship between the abnormalities and the dyspeptic symptoms.
The patients were referred to us as follows: (1) spontaneously, (2) sent by physicians collaborating with us, (3) referred to our open access endoscopic service.
The results show the frequency of idiopathic dyspepsia was 26%, whereas associated structural abnormalities were present in 45.4%.
Obvious organic causes of dyspepsia were seen in 28.6% (24% benign and 4.6% malignant diseases).
When considered separately, no symptom alone allows a correct diagnosis.
The simultaneous evaluation of the symptoms with linear discriminant analysis distinguishes between idiopathic and organic dyspeptic patients in about 70% of the cases.
A higher discrimination percentage in about 70% of the cases.
A higher discrimination percentage could probably be obtained using a wider range of clinical parameters and/or a more complex statistical analysis of the interrelationships which exist between the clinical symptoms and the final diagnosis.
| 22Pathological Conditions, Signs and Symptoms
|
Evaluation of 13C-urea breath test in the detection of Helicobacter pylori and in monitoring the effect of tripotassium dicitratobismuthate in non-ulcer dyspepsia
Sixty nine patients with non-ulcer dyspepsia have been studied with endoscopy, biopsy, quick urease (CLO) test, Helicobacter pylori culture, and the 13C-urea breath test before and after treatment with tripotassium dicitratobismuthane (DeNol) two tablets twice daily for four weeks.
Symptoms of non-ulcer dyspepsia were recorded using a standard questionnaire.
Using H pylori culture as the gold standard, the sensitivity of the 13C-urea breath test was 90%, the specificity 98.6%, and the accuracy 94.8% with a positive predictive value of 98.2% and a negative predictive value of 92.5%.
Conversion rate from H pylori positive to negative status after treatment with tripotassium dicitratobismuthate was 17.9%.
Symptoms of non-ulcer dyspepsia improved appreciably after treatment irrespective of H pylori status.
The 13C-urea breath test is an accurate research tool suitable for serial testing and population surveys.
| 22Pathological Conditions, Signs and Symptoms
|
Demonstration of an area of slow conduction in human atrial flutter.
Ten patients with chronic atrial flutter were studied prospectively using electrophysiologic mapping and pacing techniques to assess the mechanism of atrial flutter and the presence of an area of slow conduction in the atria.
Electrograms recorded from greater than or equal to 30 right atrial sites for each patient during atrial flutter demonstrated that right atrial free wall activation was craniocaudal and that the interatrial septum activation was caudocranial, consistent with a reentrant circuit involving the right atrium.
In six patients, slow conduction occurred during atrial flutter in the inferior right atrium and was spatially associated with fractionated electrographic recordings.
In the other four patients, a "missing" interval of electrical activity occurred in the inferior right atrium for an average of 40% of the atrial flutter cycle.
Transient entrainment criteria were demonstrated in each patient during rapid high right atrial pacing.
The mean activation time from the high right atrial pacing site to the coronary sinus (inferior left atrial) recording site was long (228 ms) and consistent with activation through an area of slow conduction.
During rapid pacing of atrial flutter from the coronary sinus site, no transient entrainment criteria could be demonstrated.
The mean activation time from the coronary sinus pacing site to the high right atrial recording site was relatively short (134 ms) and consistent with orthodromic activation of the high right atrium not through an area of slow conduction.
High right atrial pacing during sinus rhythm at rates similar to atrial flutter demonstrated a short activation time to the coronary sinus and low right atrial sites (mean 169 and 88 ms, respectively), indicating activation that did not traverse an area of slow conduction.
Coronary sinus pacing during sinus rhythm demonstrated the same phenomena.
Low right atrial electrograms recorded during sinus rhythm and during rapid pacing of sinus rhythm were not fractionated, although they were during atrial flutter.
Thus, atrial mapping and pacing data were complementary, indicating that human atrial flutter in the patients studied was generated by a reentrant circuit in the right atrium, with an area of slow conduction in the low right atrium present only during atrial flutter.
| 22Pathological Conditions, Signs and Symptoms
|
Analysis of base station morphine orders: assessment of supervising physician consistency.
Paramedic contact with a base station should gemerate consistent recommendations reflecting a consensus of base station physician care.
In our urban EMS system, paramedics must contact a single base station to provide morphine sulfate (MS) for a patient with chest pain.
We performed a retrospective cohort analysis of all prehospital MS requests for chest pain to determine the consistency of the circumstances for which the paramedic team was refused MS.
These MS requests represented 123 of the 1,715 (7%) on-line physician consultations during the 6-month study.
Only 15 of the 123 (12%) MS requests were refused.
Neither the mean patient age, sex distribution, or presenting vital signs correlated with MS refusal.
A maximum estimate of transport time to the hospital of less than or equal to 5 minutes was noted for 7 of 15 (47%) medication refusals compared to only 11 of 96 (11%) approvals with documented estimated transport times (P less than or equal to 0.005).
A simultaneous request for nitroglycerin (NTG) was noted for 6 of the 15 (40%) medication refusals and 15 of the 108 (14%) approvals (P less than 0.05).
We found refusal of MS administration to be uncommon.
Supervising physicians tended to refuse MS when the transport time was short and when NTG was requested for concomitant administration.
We also noted physician inconsistencies in refusal scenarios.
These findings can guide physician consensus development to avoid sending mixed messages to paramedics.
| 22Pathological Conditions, Signs and Symptoms
|
Predictors of quitting smoking: the NHANES I followup experience.
There are no published prospective studies on the predictors of spontaneously quitting cigarette smoking in a nationally-representative U.S.
population.
This paper describes such a study, using a cohort taken from the First National Health and Nutrition Examination Survey (NHANES I, 1971-1975) and traced by the NHANES I Epidemiologic Followup Survey (1982-1984).
"Successful" quitting (for at least 1 year at time of followup) was ascertained among 4779 adults (age 25-74 years) who were smokers at the time of NHANES I and not disabled at followup.
Independent predictors of quitting (by proportional hazards multiple regression) were: (1) older age; (2) White race; (3) fewer cigarettes smoked/day; (4) higher household income; and (5) hospitalization in the followup period.
Predictors of relapse (ex-smokers at NHANES I who were smoking again at time of followup) were: (1) younger age; (2) urban residence; and (3) female gender.
These findings have implications for intervention strategies, public health projections and further research.
| 22Pathological Conditions, Signs and Symptoms
|
Role of membrane proteins in monosodium urate crystal-membrane interactions. II. Effect of pretreatments of erythrocyte membranes with membrane permeable and impermeable protein crosslinking agents.
Intact, human erythrocytes were pretreated with membrane permeable, dimethyl adipimidate (DMA) and dimethyl suberimidate (DMS) and membrane impermeable 3,3' dithiobis (sulfosuccinimidylpropionate) (DTSSP) protein crosslinking agents and incubated with monosodium urate monohydrate (MSUM) crystals.
The percent inhibition of lysis values for pretreated cells relative to untreated cells were determined.
All 3 agents caused a concentration dependent inhibition of MSUM induced hemolysis that was not due to a decrease in MSUM binding to the pretreated membranes.
It was proposed that the inhibition of lysis was due to crosslinking of integral and cytoskeletal membrane proteins, resulting in a reduced mobility of the proteins, inhibition of lateralization of integral proteins into aggregates and decreased "pore" formation in the membrane.
| 22Pathological Conditions, Signs and Symptoms
|
Biliary and gut function following shock.
The aim of this study was to characterize the alterations in gallbladder and intestinal function after hemorrhagic shock and blood reperfusion in opossums.
Animals were subjected to a shock of 30 mm Hg of arterial blood pressure for 60 minutes and resuscitated with blood reinfusion.
Gallbladder epithelial ion transport, gallbladder motility in vitro and in vivo, gastrointestinal motility, and flora of the stomach and small bowel were studied 2 and 24 hours after shock.
Changes at 2 hours included decreased gallbladder contractility in vitro and decreased emptying in vivo, loss of coordination with intestinal motor activity, decrease in frequency of intestinal electrical slow waves, and reduced duration of the intestinal migrating motor complex cycle.
By 24 hours, gallbladder epithelial permeability was increased and in vitro contractility remained reduced but the in vivo functions showed partial recovery.
Gastrointestinal flora was not affected by these changes.
These data demonstrate that hemorrhagic shock and reperfusion affect digestive motility.
The early timing of the alterations observed and the partial recovery 24 hours post shock suggest an ischemia-hypoxia mechanism of injury.
| 22Pathological Conditions, Signs and Symptoms
|
Short-term and long-term changes in renal function after donor nephrectomy.
We retrospectively examined the effect of nephrectomy on renal function in 55 living related donors.
Renal function was measured with 131iodine-orthoiodohippurate scans.
All patients were studied preoperatively, and 1 week and 1 year postoperatively.
In 20 patients 10-year followup was available.
Compensatory hypertrophy was complete 1 week postoperatively: effective renal plasma flow of the remaining kidney was 32.5% higher than preoperatively.
The increase remained stable for at least a year.
The degree of compensatory hypertrophy was significantly greater in male patients (46.9% after 1 week) than in female patients (26.7%).
Compensatory hypertrophy occurred in all age groups studied and it was most pronounced in patients less than 30 years old.
In the patients followed for 10 years effective renal plasma flow decreased from 387.7 ml.
per minute 1 week after nephrectomy to 367.4 ml.
per minute at 10 years.
This result is similar to the decrease seen in the normal population.
According to our results, renal donation by living related persons does not lead to long-term decrease in renal function.
| 22Pathological Conditions, Signs and Symptoms
|
Treatment of idiopathic retroperitoneal fibrosis by immunosuppression.
Idiopathic retroperitoneal fibrosis is exceedingly uncommon in childhood and its etiology is uncertain.
Support for an immunological basis for the disease is given by a report of a 14-year-old girl with severe retroperitoneal fibrosis causing progressive azotemia in whom azathioprine and prednisolone were used successfully.
This case supports the efficacy of immunotherapy in the treatment of idiopathic retroperitoneal fibrosis.
| 22Pathological Conditions, Signs and Symptoms
|
En bloc transplantation of kidneys from donors weighing less than 15 kg. into adult recipients.
En bloc transplantation of kidneys from donors who weighed less than 15 kg.
into 20 adult patients is described.
Intraperitonealization of the medial kidney allowed adequate renal positioning and growth.
Graft venous thrombosis occurred in 1 patient and irreversible graft rejection occurred in 4 patients.
Graft survival was 65% with excellent function at a mean followup of 8.8 months.
En bloc transplantation of pediatric cadaver kidney grafts in adults is an acceptable procedure.
| 22Pathological Conditions, Signs and Symptoms
|
Afferent nipple valve malfunction caused by anchoring collar: an unexpected late complication of the Kock continent ileal reservoir.
In the construction of a Kock continent ileal reservoir for urinary diversion, significantly high rates of late postoperative complications regarding nipple valves, the efferent limb in particular, have been reported.
There are only a few reports on afferent nipple valve malfunction.
A total of 42 patients who underwent a Kock pouch operation and were observed for more than 12 months (mean 38 months) was evaluated in terms of afferent nipple valve malfunction.
Late afferent nipple valve complications were observed in 10 of the 42 patients (24%).
These complications included erosion of the polyester fiber fabric used as a collar (5 patients), stenosis of the afferent limb (2) and obstruction of the afferent nipple by a mucous plug or fungus ball (3).
The latter 2 complications were due to mechanical or dynamic obstruction of urine flow caused by a nonabsorbable collar.
None of the 10 patients had problems with efferent nipple valve function.
Our results suggest that the peristaltic direction of the intestine and the use of nonabsorbable material as a collar are primarily responsible for the late afferent nipple valve complications.
Further modifications are needed to produce a stable nipple valve.
Otherwise, simpler and more reliable alternative techniques of antireflux anastomosis should be considered.
| 22Pathological Conditions, Signs and Symptoms
|
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