Rifamycins: modulation of specific anti-poxviral activity by small substitutions on the piperazinyliminomethyl side chain

Rifamycin derivatives differing in the substitutent at the 4 position of the piperazinyliminomethyl side chain were tested for anti-poxviral activity. The effects of each derivative on wild-type vaccinia virus and on a mutant selected for resistance to rifampin were determined. Antiviral activity was measured in tissue culture by plaque inhibition, reduction in virus yield, and specific interruption of virus morphogenesis. Rifamycin derivatives containing H, ethyl, or propyl groups at the 4 position of the piperazinyliminomethyl side chain were much less active than rifampin, which has a methyl group at this position. Thus, minimal shortening or lengthening of the methyl piperazinyliminomethyl side chain of rifampin led to loss of specific antiviral activity. In contrast, the derivative containing an amino group at the 4 position of the piperazinyliminomethyl side chain had enhanced anti-poxviral activity.

Immunogenicity of rabies virus inactivated by -propiolactone, acetylethyleneimine, and ionizing irradiation

Ionizing radiation, beta-propiolactone, and acetylethyleneimine were compared for their ability as virus-inactivating agents for the preparation of rabies vaccine. Each agent reduced viral infectivity exponentially; ionizing radiation also destroyed viral hemagglutinin. The vaccine prepared by ionizing radiation was equal or superior to that prepared by beta-propiolactone in its ability to protect mice from rabies infection. The acetylethyleneimine-treated vaccine was a less potent immunogen.

Effects of a new oral hypoglycemic agent on glucose and insulin after oral glucose loading. A controlled study

l-(2-pyrimidinyl)-4-imino-l, 4-dihydropyridine hydrochloride is a new compound which after oral administration of a single dose of 400 mg. causes significant reductions of hyperglycemia and insulin response in human subjects after an oral glucose load. These results were obtained when compared to a single dose of 200 mg. of phenformin hydrochloride or placebo in a double-blind completely randomized crossover study with placebo and phenformin. Both drugs also produced a significant fall in the fasting serum glucose value before the oral glucose load without any significant effect on serum insulin values. Both drugs produced similar adverse symptoms in the six healthy subjects who participated in the study.