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Biomedical subjects

I Oishi

Publications and source records attributed to I Oishi.

68 records · Page 4Linked to original sources

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. When Formalin-treated red blood cells were sensitized with this antitoxin, the antibodies coupled to the cells were, for practical results, only anti-Abeta. When the suspension is reacted with dilutions of type A toxic solutions, the limiting dilutions are determined by Abeta and not by the neurotoxin, which should be the determinant if the assay is to measure toxicity. These observations may be pertinent to the development of serological assays for other botulinal toxin types.

Animals↗

Purification of Clostridium botuliunum type F progenitor toxin.

Clostridium botulinum type F progenitor toxin was purified to a homogeneous state as judged by gel filtration on Sephadex G-200, ultracentrifugation, and disc electrophoresis. The sedimentation constant, corrected to water at 20 C, of type F progenitor toxin was determined to be 10.3 and the molecular weight to be 235,000 by ultracentrifugation at pH 6.0. The purified toxin contained a toxicity of 1.2 x 10(8) 50% lethal doses/mg of N. In agar gel double diffusion, it formed two precipitin lines at pH 6.0. The progenitor toxin of type F differs from that of type A in that it contains no hemagglutinin and from that of type E in that it is not activable.

Ammonium Sulfate↗

Anti-HIV-1 activity of myo-inositol hexaphosphoric acid (IP6) and myo-inositol hexasulfate(IS6).

It is known that polysulfates have some anti-HIV-1 activity. We investigated the anti-HIV-1 activity of myo-inositol hexaphosphoric acid (IP6) and myo-inositol hexasulfate(IS6), low molecular weight carbohydrates. IP6 and IS6 inhibited the replication of HIV-1 in a T cell line as well as that of a freshly isolated strain in peripheral blood mononuclear cells. Neither substance inhibited HIV-1-induced giant cell formation, but addition of IS6 when infecting cells with HIV-1 inhibited the replication of HIV-1. Neither substance inhibited HIV-1 reverse transcriptase activity in vitro and no influence on late stage replication was noted. Although the mechanisms of IP6 and IS6 action remain unclear, it can be speculated that they act on HIV-1 early replicative stage. Although it is not possible to develop IP6 and IS6 themselves as anti-AIDS drugs, studies of these anti-HIV agents might be expected to provide seed for eventual production of superior drugs for AIDS treatment.

Anti-HIV Agents↗