Campylobacter enteritis in Johannesburg

In order to establish a reasonable protocol for a diagnostic laboratory we conducted a survey during which we confined the routine culture of stool samples for Campylobacter fetus to two groups--all infants under 2 years of age, and older children and adults with obviously diarrhoeic stools. Camp. fetus was isolated from 100 of 2323 stool specimens (4,3%). This is within the 3 - 8% isolation rates previously reported from surveys in which all specimens were cultured. Camp. fetus isolates represented 16,9% of all bacterial pathogens isolated, and Black infants showed a significantly greater isolation rate than White infants. We feel that culture for Camp. fetus is an essential part of any routine bacteriological investigation of diarrhoea. A partially selective culture policy for Camp. fetus will result in a recovery rate at least equal to that of Salmonella and enteropathogenic Escherichia coli.     

Nitrosation of dialkylamines in the presence of bile acid conjugates

The rate of nitrosation of dihexylamine is enhanced when the reaction is carried ut in the presence of micelles containing bile acid conjugates or bile acid conjugates and lecithin. The nitrosation of smaller dialkylamines is not affected. The nitrosation of dihexylamine under these conditions is inhibited by alpha-tocopherol at pH 3 or pH 5. At pH 3 the reaction is inhibited by ascorbic acid, while at pH 5 it is inhibited by equimolar concentrations of ascorbic acid, but accelerated by higher concentration of ascorbic acid. The effect of ascorbic acid at pH 5 depends on the presence of oxygen and sulfamate.     

Hepatitis among plasma fractionation workers. An industry-wide study

An industry-wide survey of plasm fractionation facilities in the United States was conducted during 1973-74. Hepatitis was reported among the workers with varying degrees of plasma contact at all plant sites. For each of fourteen facilities in this investigation, field inspections disclosed: (1) numerous overt instances of employee-product contact: (2) inconsistent methodologic approaches at virtually all stages of the plasma fractionation process; (3) at low level of management and employee awareness regarding the potential bio-hazard identified; and (4) disparate examples of hepatitis surveillance and prophylaxis. Our data suggests that there is a high risk of hepatitis among plasma fractionation workers and, as such, much more attention needs to be focused on the reduction of health hazards within this industry.     

Minimizing corneal endothelial damage due to intraocular lens contact

Previous studies have shown that momentary contact between a methylmethacrylate intraocular lens and the corneal endothelial cells results in extensive cell damage. This contact damage is reduced by coating the pseudophake with various solutions prior to contact with the endothelium.     

Human brain metabolic response to caffeine and the effects of tolerance

OBJECTIVE: Since there is limited information concerning caffeine's metabolic effects on the human brain, the authors applied a rapid proton echo-planar spectroscopic imaging technique to dynamically measure regional brain metabolic responses to caffeine ingestion. They specifically measured changes in brain lactate due to the combined effects of caffeine's stimulation of glycolysis and reduction of cerebral blood flow. METHOD: Nine heavy caffeine users and nine caffeine-intolerant individuals, who had previously discontinued or substantially curtailed use of caffeinated products because of associated anxiety and discomforting physiological arousal, were studied at baseline and then during 1 hour following ingestion of caffeine citrate (10 mg/kg). To assess state-trait contributions and the effects of caffeine tolerance, five of the caffeine users were restudied after a 1- to 2-month caffeine holiday. RESULTS: The caffeine-intolerant individuals, but not the regular caffeine users, experienced substantial psychological and physiological distress in response to caffeine ingestion. Significant increases in global and regionally specific brain lactate were observed only among the caffeine-intolerant subjects. Reexposure of the regular caffeine users to caffeine after a caffeine holiday resulted in little or no adverse clinical reaction but significant rises in brain lactate which were of a magnitude similar to that observed for the caffeine-intolerant group. CONCLUSIONS: These results provide direct evidence for the loss of caffeine tolerance in the human brain subsequent to caffeine discontinuation and suggest mechanisms for the phenomenon of caffeine intolerance other than its metabolic effects on elevating brain lactate.     

Idiopathic thrombocytopenic purpura in a liver transplant recipient with previous primary biliary cirrhosis

The loss of immunotolerance has been implicated in the pathogenesis of both primary biliary cirrhosis (PBC) and idiopathic, immune-mediated thrombocytopenic purpura (ITP). An association between these two autoimmune diseases has been well described. We describe a 41-year-old woman in whom ITP developed 457 days after liver transplantation for PBC while receiving immunosuppressive medications sufficient to maintain allograft function. Our case report, the first to describe post-transplant ITP in association with PBC, demonstrates the persistence of the underlying immune dysregulation of PBC after transplantation. The practice of decreasing the dosage of immunosuppressive medication to maintenance levels after transplantation may unmask the effects of this defect in immunotolerance.