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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 811 records · Page 45Linked to original sources
PubMed1977

[Studies on arsenic metabolism (XX). Arsenic accumulation in the organs and excretion into the feces and urine of rats chronically poisoned with arsenic (author's transl)].

Male and female rats (60 approximately 80 g) of Wistar strain were randomly divided into two groups and were given milk and cereal diets, respectively. Each group was further divided into two groups; one was given the diet containing 100ppm of arsenic trioxide and the other a diet containing "arsenic compound" (100ppm as arsenic trioxide). Each group included five rats of both sexes. A 6-month feeding of the test diet was followed by provision of a normal diet. The accumulated arsenic was excreted almost 100% from the brain and 20 approximately 30% from organs such as kidney, liver, spleen and lung. The arsenic level persisted in tissues in animals on the cereal diet, as compared with those fed the milk diet. There was no significant difference in the accumulation and excretion of arsenic between the groups given arsenic trioxide or "arsenic compound".

Animals↗
PubMed1976

Mating reaction in Saccharomyces cerevisiae. IX. Regulation of sexual cell agglutinability of a type cells by a sex factor produced by alpha type cells.

A diffusible sex-specific substance called alpha substance-I (alphaS-I) was isolated from culture filtrate of alpha type strains of the yeast Saccharomyces cerevisiae. The isolated alphaS-I, an oligopeptide, induced sexual cell agglutinability in inducible alpha type strains and enhanced the agglutinability in constitutive a type strains. The induction of sexual agglutinability was detected in 30 min and reached maximum in 90 min, when 0.2 mug/ml of alphaS-I was added to inducible a type cells. The a type-specific factor responsible for sexual cell agglutination, called a type agglutination factor (aAF), was shown to be produced during the induction or the enhancement of agglutinability of a type cells by alphaS-I. The aAF produced in response to alphaS-I was not different in the susceptibility to proteolytic enzymes and disulfide-cleaving agents from those produced constitutively in the absence of alphaS-I.

Agglutination↗
PubMed1976

Properties of purified hydrogenase from the particulate fraction of Desulfovibrio vulgaris, Miyazaki.

The properties of purified hydrogenase [EC 1.12.2.1] solubilized from particulate fraction of sonicated Desulfovibrio vulgaris cells are described. The enzyme was a brownish iron-sulfur protein of molecular weight 89,000, composed of two different subunits (mol. wt.: 28,000 and 59,000), and it contained 7-9 iron atoms and 7-8 labile sulfide ions. Molybdenum was not detected in the preparation. The absorption spectrum of the enzyme was characteristic of iron-sulfur proteins. The millimolar absorbance coefficients of the enzyme were about 164 at 280nm, and 47 at 400nm. The absorption spectrum of the enzyme in the visible region changed upon incubating the enzyme under H2 in the presence of cytochrome c3, but not in its absence. This spectral change was due to the reduction of the enzyme. The absorbance ratio at 400nm of the reduced and the oxidized forms of the enzyme was 0.66. The activity of the enzyme was hardly affected by metal-complexing agents such as cyanide, azide, 1,10-phenanthroline, etc., except for CO, which was a strong inhibitor of the enzyme. The activity was inhibited by SH-reagents such as p-chloromercuribenzenesulfonate. The enzyme was significantly resistant to urea, but susceptible to sodium dodecyl sulfate. These properties were very similar to those of clostridial hydrogenase [EC 1.12.7.1], in spite of differences in the acceptor specificity and subunit structure.

Amino Acids↗