Biliary excretion of glycolipid in induced or inherited glucosylceramide lipidosis

Metabolically inert L-[1-14C]glucosylceramide is stored predominantly in the liver after intravenous administration to mice. The half-time of this glycolipid analogue in the liver is 3.5 days and its clearance occurs predominantly via the bile. Within the limited number of Gaucher specimens available for examination very high levels of glucosylceramide were found in the bile of one patient and in the liver of two patients with biliary obstruction. The question of a possible relationship between biliary excretion of glycolipid and the pathogenesis of Gaucher's disease will require further studies.

Disopyramide and neuromuscular transmission

The effect of disopyramide on neuromuscular transmission has been studied using the rat isolated phrenic nerve-diaphragm preparation. The response of the muscle to indirect nerve stimulation was decreased in the presence of disopyramide 5.6 x 10(-6) mol litre-1 (P less than 0.05), total blockade occurring at 5.6 x 10(-4) mol litre-1. Marked augmentation of the response to direct muscle stimulation was recorded in the presence of disopyramide 1.8 x 10(-4)-5.6 x 10(-4) mol litre-1. Disopyramide 5.6 x 10(-6) mol litre-1 caused a leftward shift of the log concentration response for tubocurarine and decreased the antagonist effect of neostigmine.

Sterilization of bacteria by means of microwave heating

Despite the simplicity and convenience of microwave heating, descriptions in the current literature of attempts to provide a thorough sterilization process have not been encouraging nor has any manufacturer of sterilization equipment introduced such a device to the market. Trials conducted at Providence Hospital using a commercial microwave oven operating at 2450 MHz resulted in a satisfactory sterilization process, that is, the destruction of heat-resisting spore forms (B. stearothermophilus), provided that the materials undergoing sterilization were placed in sealed containers with sufficient water present to provide steam during the heating process. Suggestions are made for further investigation involving the microwave spectrum of the molecule of dipicolinic acid as well as the possibilities of practical applications which could result in reducing hospital costs.

Low-dose heparin prophylaxis against fatal pulmonary embolism

A prospective randomised controlled trial in 500 patients over the age of 50 who were undergoing major surgery showed that low-dose subcutaneous heparin was an effective prophylactic measure against fatal pulmonary embolism. None of the 252 patients who received perioperative heparin cover died of fatal pulmonary embolism while eight of the 236 who did not receive heparin prophylaxis died of fatal pulmonary embolism. These results were statiscally significant (P less than 0.01).

Comparative convulsant activity of various penicillins after intracerebral injection in mice

The convulsant effects of penicillin derivatives (penicillin G, Phenoxymethylpenicillin, penicillin O, ampicillin, methicillin) and cephaloridine have been evaluated after being given intracerebrally to mice. Penicillin G was most neurotoxic; ampicillin and Phenoxymethylpenicillin were one-fifth as toxic. Incubation with penicillinase markedly reduced or eliminated the convulsant effects of penicillin G, Phenoxymethylpenicillin and ampicillin; this enzyme incubation did not alter the severity of seizures elicited by methicillin and cephaloridine. Diphenylhydantoin and phenobarbitone did not reduce penicillin G-induced seizures. A non-convulsant dose of leptazol potentiated the convulsions produced by the penicillins and cephaloridine. Injection volume, pH and the concentration of sodium and potassium did not produce behavioural changes within the ranges studied.