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Biomedical subjects

M Yagi

Publications and source records attributed to M Yagi.

At least 253 records · Page 14Linked to original sources
PubMed1979

Oxidation of tryptophan-P-1 and P-2 by beef liver catalase-H2O2 intermediate: comparison with horseradish peroxidase.

Tryptophan-p-1 (trp-p-1) and p-2, which have high mutagenic and carcinogenic potential, are oxidized by catalase- and horseradish peroxidase (HRP)-H2O2 intermediates with optimum pH 5.9 (0.2 M-acetate) in catalase and pH 5.0 (0.2 M-acetate), 8.0 (0.01 M-phosphate) in HRP. The rate constants (k4) of the oxidation in the catalase at pH 5.9 (0.2 M-acetate) were 2965 M-1 x sec-1 for trp-p-1 and 576 M-1 x sec-1 for trp-p-2. In the case of HRP, 1894 M-1 x sec-1, (pH 5.0, 0.2 M-acetate) for trp-p-1 and 705 M-1 x sec-1 (pH 8.0, 0.001 M-phosphate) for trp-p-2 under each optimum condition. The oxidation products of trp-p-1 and p-2 by catalase or HRP lost completely their mutagenic potential in the mutation assay.

Animals↗
PubMed1975

Bulk flow in the cerebrospinal fluid system of the dog.

Ventriculo-cisternal, intracranial subarachnoid-to-subarachnoid space and spinal subarachnoid space perfusions were carried out on dogs. The perfusate contained inulin as a tracer and the design of these experiments was based upon the concept that inulin leaves cerebrospinal fluid (CSF) compartments only by means of bulk absorption, and that actual diffusion and active transport of inulin is negligibly small. Inulin was removed from different CSF spaces by bulk absorption at rates which varied linearly with hydrostatic pressure. The rate of formation of CSF is equal to inulin clearance plus the difference between outflow and inflow rates. The total CSF formation in dogs weighing 12 to 17 kg was measured as 0.065 ml/min, and 58.5 per cent of this amount was found to come from extraventricular CSF space. The rates are independent of hydrostatic pressure in the range studied.

Animals↗