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Biomedical subjects

T Ohashi

Publications and source records attributed to T Ohashi.

At least 415 records · Page 23Linked to original sources

Bilateral carcinoma of the ears. Report of a case.

We report a rare case of bilateral carcinoma of the ears in a 41-year-old man. The second tumor developed from the left mastoidectomized middle ear cavity eight years after the complete healing of the first tumor, which probably originated in the glands of the right external auditory canal.

Adult↗

Mechanism of inactivation of bacteriophage deltaA containing single-stranded DNA by ascorbic acid.

The mechanism of inactivation of a single-stranded DNA phage, deltaA of Escherichia coli, by AsA was investigated as a part of the study on the mechanism of inactivation of viruses by AsA. Bubbling air or oxygen gas through the reaction mixture, and the addition of oxidizing agents or transition metals into the reaction mixture enhanced the inactivation of the phage by AsA. In contrast, nitrogen gas bubling, and the addition of reducing agents, chelating agents or radical scavengers prevented inactivation. The rate of inactivation was faster in the AsA solution preincubated for several minutes than in the freshly prepared AsA solution. DAsA, an oxidized form of AsA, demonstrated little effect on the activity of the phage. Concentrations of hydrogen peroxide which were theoretically produced by the autoxidation of AsA had no effect on the phage. The results indicated that the free radical intermediates produced during the course of the autoxidation of AsA participated in the inactivation. The radicals attacked the DNA of the phage to introduce strand scissions in the DNA, which might be mainly responsible for the inactivation.

Ascorbic Acid↗

The effect of butaclamol and of other neuroleptic agents on the apomorphine-elicited inhibition of synaptosomal tyrosine hydroxylase activity.

The effects of the two enantiomers of butaclamol and of several neuroleptics on the apomorphine-elicited inhibition of synaptosomal tyrosine hydroxylase activity was investigated. The (+) but not the (-) enantiomer of butaclamol reverses the apomorphine-elicited enzyme inhibition. (+) Butaclamol is more potent than the other tested neuroleptics. All the tested neuroleptics reverse the apomorphine-elicited enzyme inhibition but their relative potency differs. Using two criteria, namely the concentrations of neuroleptics required to reverse enzyme inhibition maximally or by 25%, the order of decreasing potency is as follows: (+) butaclamol, fluphenazine, haloperidol, pimozide, chlorpromazine. The results suggest that the reversal of apomorphine-elicited inhibition of synaptosomal tyrosine hydroxylase activity is a valid test model for screening antipsychotic drugs.

Animals↗