ELectrophysiologic properties of bretylium tosylate on atrial myocardium.

The antifibrillatory property of bretylium tosylate was first observed in experimental atrial fibrillation, yet the cellular basis for this phenomenon has not been explored. The purpose of this study was to determine the electrophysiologic properties of bretylium tosylate on guinea pig atrial myocardium in the presence and absence of cholinergic influence. Bretylium (10(-6) M - 10(-4) M) produced a concentration-dependent prolongation of atrial action potential duration with a threshold concentration of 10(-5) M.

Human diabetic endoneurial sorbitol, fructose, and myo-inositol related to sural nerve morphometry.

Fascicles of the sural nerve from each of 20 diabetic patients, mostly with maturity-onset diabetes, were studied by biochemical and pathological techniques, and results were compared to values found in nerve specimens from 15 healthy persons. The sorbitol and fructose content was much more variable in diabetic than in healthy nerves. More than one-third of the diabetic nerves had sorbitol and fructose values above the highest levels for controls.

Nitrous oxide neurotoxicity studies in man and rat.

To assess the effects of chronic exposure to low levels of nitrous oxide on neural function of man, the authors evaluated the neurologic condition, motor and sensory nerve conduction, and computerized tests of sensation of approximately half of the dentists in Rochester, Minnesota. Results of scored tests of neural function were not significantly different for dentists who used nitrous oxide extensively in their practices and dentists who did not. To assess the effects of chronic exposure to high levels of nitrous oxide on neural function and structure of experimental animals, groups of rats were exposed to 70 per cent N2O in 30 per cent oxygen for four hours, five days a week, for six months.