Testing patients for HIV before surgery: The views of doctors performing surgery

The aim of this study was to investigate the attitudes of doctors performing surgery to the HIV antibody testing of surgical patients. Fifty of eighty (62.5%) doctors performing surgery who are working in two London teaching hospitals returned completed anonymous postal questionnaires. Sixty-six per cent of the sample would like some form of compulsory testing of pre-operative patients, although most of them feel that this is only necessary for patients considered to be in 'high-risk groups'. Eighty-four per cent believe that this would ensure their safety from infection during surgery. Forty-eight per cent agreed with testing patients without their consent. Results suggest that most of the doctors performing surgery in this study agree with compulsory HIV antibody testing of pre-operative patients in the belief that this would protect them from infection during surgery. The problems associated with compulsory testing and relying on such testing in order to protect doctors from infection during surgery are discussed.     

Relationships between computerized measurements of motion of frozen-thawed bull spermatozoa and fertility

A computerized system (CellSoft, CRYO Resources, Ltd.) was validated using video tapes of frozen-thawed bull spermatozoa diluted in filtered (0.2 micron) egg yolk-citrate extender (8 X 10(6) spermatozoa/ml) and analyzed at 30 frames/sec for the percentage of motile spermatozoa (greater than or equal to 20 microns/sec) and linear velocity of motile spermatozoa. Virtually all motile spermatozoa were detected and debris rarely were classified as immotile spermatozoa if the extender had been filtered. Variation about the mean for percent motile cells was similar when only 12 rather than 20 or 30 frames/field were analyzed. Use of 20 frames/field was adequate to determine the percentage of motile bull spermatozoa. Five mixtures of live and killed spermatozoa were analyzed (four bulls) to evaluate accuracy. Percent motile spermatozoa was correlated (r = 0.97) with the ratio of live:killed spermatozoa. Mean linear velocity of motile spermatozoa was similar for each mixture (P greater than 0.05). To further evaluate accuracy, percent motile spermatozoa was determined by computer and by "track motility" (20 samples; 0 to 63% motile spermatozoa); values were correlated (r = 0.95). The system was precise (CV of 6% based on triplicate analyses of the same samples) and reasonably accurate for evaluating bull sperm motility if the extender had been filtered and 20 to 25 fields (greater than or equal to 200 spermatozoa) were evaluated. Correlations between measurements of sperm motion and fertility were studied using cryopreserved semen from two fertility trials. For the first, 75-day nonreturn rate data for 20 samples of bull semen (10 bulls) were not significantly correlated with evaluations made by CellSoft. For the second fertility trial, the competitive fertility index (a measure of relative fertility) for nine bulls was correlated (r greater than or equal to 0.68; P less than 0.05) with percent motile spermatozoa, linear velocity and straight-line velocity. Multiple correlations based on six characteristics evaluated by CellSoft, at 0 or 1.5 hours, and the competitive fertility index were greater than or equal to 0.94. Based on the latter data, the system may facilitate prediction of the relative fertility of bull spermatozoa.     

Staff members' acceptance of the introduction of workplace smoking bans in the Australian public service

The acceptability to employees of workplace smoking bans is an important factor in their introduction and in subsequent compliance. This study describes the acceptance by affected staff members before the ban on smoking in Australian public-service premises. Four thousand, two hundred and fifteen (79% of those who were approached) public servants were surveyed from areas of six departments across three states. Twenty-five per cent of the sample were current smokers. Support for the bans was strong, with 76% of the sample approving over all. Approval among smokers was less, with 40% of smokers approving, compared with 82% of ex-smokers and 90% of "never" smokers. Thus, the results show a generally favourable attitudinal milieu among employees who were facing an impending ban on smoking, and far-from-unanimous opposition from smokers. Among smokers, acceptance of the bans was predictable from the attitudes towards smoking acceptance of the bans was predictable from the attitudes towards smoking in general, and from the perceived impact of the bans on smokers. The existence of restrictions on smoking at the time of the survey was associated with slightly higher levels of approval of the impending total ban, especially when the restrictions were not seen as being imposed on the respondents by others.     

A Comparison of the Cholinergic Activity of Selected H2-Antagonists and Sulfoxide Metabolites

Famotidine and selected H₂-antagonists were evaluated with respect to toxicity and selected pharmacological activities. When administered intraperitoneally to mice at a dose equivalent to 10 times their respective H₂-antagonist ED₅₀ values, no deaths were observed. Similarly, no alteration in brain ACh concentrations or overt pharmacological effects were noted. However, at 400 mg/kg, ranitidine produced 89% lethality, followed by cimetidine (11%) and famotidine. Only cimetidine and famotidine at this dose significantly elevated brain acetylcholine levels. These results do not correlate with the in vitro data, where ORF-17578 and ranitidine were the most potent entities with respect to acetylcholinesterase inhibition (1–2 × 10^–6 M), followed by nizatidine > cimetidine > famotidine. The sulfoxide metabolites of ranitidine and cimetidine were approximately one-tenth as potent as their parent compounds with respect to inhibition of acetylcholinesterase. Direct muscarinic stimulation or potentiation of acetylcholine-induced contraction in ileal tissue was not observed for any of the H₂-antagonists.     

Acetazolamide and renal ammoniagenesis.

The effect of acetazolamide on ammonia-producing enzyme systems was determined in vitro at concentrations comparable to those which have been shown to abolish ammonium excretion in vivo. No change in the activity of glutaminase or gamma-glutamyl transpeptidase could be observed at concentrations up to 0.2 mM acetazolamide, and concentrations up to 1 mM were without effect on D-glutamyltransferase activity. Therefore, the effect of acetazolamide to abolish ammonium excretion cannot be explained by an action of the drug to inhibit ammoniagenesis.     

Longitudinal histopathologic assessment of rejection after bladder-drained canine pancreas allograft transplantation

In preparation for assessment of percutaneous biopsies in our clinical pancreas transplant program, a working knowledge of the histopathologic changes after transplantation was obtained in a longitudinal open biopsy study of 16 dogs receiving bladder-drained whole pancreas allografts. Edema, extravasation of polymorphs, and lymphocytes associated with focal parenchymal injury were early, invariable, and probably nonspecific findings. The initial feature of unmodified rejection was the appearance of capillary and small vein endothelial changes with mainly perivascular inflammatory cell infiltration. Acinar cell loss occurred early and was progressive, whereas islets and ducts were relatively preserved, indicating that acinar tissue may be more vulnerable to lytic necrosis when damaged. Functional rejection, determined by fasting urinary amylase levels, was at a stage of extensive and irreversible necrosis. Functioning grafts in immunosuppressed dogs had minor and transient endothelial changes with absence of class II antigen staining of parenchymal cells.     

The effect of drinking tea at high altitude on hydration status and mood

The effect of drinking tea on hydration status and mood was studied in nine male and four female members of expeditions based at Mt. Everest base camp at an altitude of 5,345 m. Whilst exposed to altitude-cold diuresis, participants were subjected to a crossover experimental design comprising two 24-h dietary interventions. In the tea condition, hot brewed tea formed a major part of fluid intake, whereas in the no-tea condition tea was excluded from the diet. Subjects were prohibited in both cases from consuming other caffeinated beverages, caffeinated foods, and alcoholic drinks. Mean fluids ingested [mean (SE); tea=3,193 (259) ml versus no tea=3,108 (269) ml] and urine volume (tea=2,686 (276) ml versus no tea=2,625 (342) ml] were similar under both conditions. Statistical analysis found no difference in urine stimulated as a result of the tea intervention (P=0.81). Several markers of hydration status were also taken immediately pre and post each condition, including measures of urine specific gravity, urine electrolyte balance (K⁺, Na⁺), and urine colour. None of these measures indicated a difference in hydration status as a result of the dietary intervention in either the control or tea condition. A difference was, however, found in mood, with subjects reporting reduced fatigue when tea was included in the diet (P=0.005). The study shows therefore that even when drunk at high altitude where fluid balance is stressed, there is no evidence that tea acts as a diuretic when consumed through natural routes of ingestion by regular tea drinkers, but that it does have a positive effect on mood.     

The effect of experimental iron-overload on splenic T cell function: analysis using cloning techniques.

The effect of iron-overload on cell-mediated immunity was examined in C57 mice. Two methods of iron-loading were used: (i) dietary carbonyl iron which produced iron-loading primarily of parenchymal cells or (ii) intraperitoneal administration of iron-dextran which produced iron-loading predominantly of Kupffer cells. Both methods of iron-loading resulted in a diminished capacity of spleen cells to generate an allo-specific cytotoxic response in the absence of exogenous interleukin 2 (IL-2). Exogenous IL-2, however, restored the ability of spleen cells from iron-loaded mice to generate allo-specific cytotoxicity in bulk culture. Clonal assays for the precursor cells of cytotoxic T lymphocytes (CTL-P), performed in the presence of added IL-2, demonstrated that iron-loaded mice contained normal numbers of CTL-P. However, cultures of spleen cells from carbonyl iron-loaded mice generated less IL-2 following Concanavalin A stimulation, apparently as a result of a reduction in the number of IL-2-secreting cells amongst the spleen cell population. This work presents further evidence that iron-overload is associated with defective immunoregulatory control.