Effect of spermidine on bacteriophage P22 infection.

The effect of spermidine on phage P22 infection of Salmonella typhimurium has been found to depend on the time of addition of spermidine with respect to the time of addition of the phage and also on the composition of the growth medium. If spermidine was added prior to or within a short time after infection, the cells survived. Under this condition the invading DNA appeared to remain trapped in the cell membrane, and there was no expression of the phage genome.

Psychopharmacological studies on (--)-nuciferine and its Hofmann degradation product atherosperminine.

(--)-Nuciferine and its Hofmann degradation product atherosperminine showed divergent psychopharmacological effects. Because nuciferine has been reported to be a neuroleptic and atherosperminine has some chemical resemblance to dopamine, they were investigated for their dopamine-receptor activities. Nuciferine had a pharmacologic profile of action associated with dopamine-receptor blockade; i.

Inhibition of Clostridium botulinum types A and B hemagglutinins by sugars.

Chromatographically isolated hemagglutinins of Clostridium botulinum types A and B are serologically related but not identical. Of the sugars (5, 6, 12, 18 carbons, some derivatives, L and D forms) tested, only D-galactose and some of tis derivatives were inhibitors of these hemagglutinins. O-Nitrophenyl-beta-D-galactopyranoside and isopropyl-beta-D-thiogalactoside were the most potent inhibitors.

Molecular forms of neurotoxins in proteolytic Clostridium botulinum type B cultures.

A modified purification method was used to isolate the neurotoxin of proteolytic Clostridium botulinum type B strain Lamanna. The preparation was found to be a mixture of two protein forms. They were of molecular weight 152,000 and could not be separated by ion-exchange chromatography or electrophoresis in polyacrylamide gel.

Detection of Clostridium botulinum toxin by local paralysis elicited with intramuscular challenge.

Clostridium botulinum toxin can be identified by a characteristic, acute local paralysis that follows its injection into the gastrocnemius ("calf" muscle) of mice. The local botulism can be elicited with slightly less than one-tenth the toxin amount that is needed to kill mice by the intraperitoneal (i.p.

Evaluation of type A botulinal toxin assays that use antitoxin to crystalline toxin.

The type A botulinal toxin assay by the reverse passive hemagglutination procedure which uses antitoxin to crystalline toxin was examined for specificity. The analysis was based on the fact that crystalline type A toxin is a complex of neurotoxic protein (Aalpha) and a nontoxic protein (Abeta). By using these components, obtained in essentially pure forms, it was shown that the antitoxin to crystalline toxin has a significantly higher titer to Abeta than to Aalpha.

Activation of Clostridium botulinum type B toxin by an endogenous enzyme.

It was previously postulated, based on indirect evidence, that Clostridium botulinum type B produces neurotoxin which is initially of low toxicity but which then becomes activated to highly toxic form by the action of an endogenous enzyme(s). The first direct in vitro experimental evidence in support of this hypothesis is presented here. The mildly active toxin (progenitor toxin) produced by C.

Amino Acid Analysis of the Isolated and Purified Components from Crystalline Toxin of Clostridium botulinum Type A.

The toxic and hemagglutinating components of the crystalline toxin of Clostridium botulinum were analyzed for their amino acid content and were proven to be completely different proteins.