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Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 685 records · Page 38Linked to original sources
PubMed1981

Induction of IgM memory with RNA from the spleens of immunized mice.

Ribonucleic acid (immune RNA, iRNA), extracted from the spleens of mice immunized with sheep red blood cells (SRBC), induced specific immunological memory. The humoral immune responses of iRNA-treated animals were compared with in vivo and in vitro primary and secondary responses, using the haemolytic plaque-forming cell (PFC) assay. IgM antibody formation was markedly higher in iRNA-treated than in any other mice. The effect of iRNA was antigen-specific and similar materials from non-immunized mice had no activity.

Animals↗
PubMed1981

Induction of changes in the pepsinogen content and the pepsinogen isoenzyme pattern of the pyloric mucosa of the rat stomach by short-term administration of stomach carcinogens.

Changes in pepsinogen isoenzyme patterns were examined in the pyloric mucosae of the stomachs of noninbred male Wistar rats after short-term administration of gastric carcinogens. N-Methyl-N-nitro-N-nitrosoquanidine, N-ethyl-N1-nitro-N-nitrosoguanidine, and N-propyl-N-nitro-N-nitrosoguanidine, which induce stomach cancer in rats, decreased the content of pepsinogen isoenzyme 1 )Pg 1), which was separated by poly-acrylamide gel electrophoresis. They also decreased the pepsingoen content of the pyloric mucosa. 4-Nitroguinoline 1-oxide, which induces a low incidence of stomach cancer in rats, rarely decreased the Pg 1 content or the pepsinogen content of the pyloric mucosa, and the incidence of such decreases was not statistically significant. However, diethylnitrosamine and dimethylnitrosamine, which do not induce stomach cancer in rats, did not cause any decrease in pepsinogen content. Ethyl methanesulfonate, a direct-acting carcinogen used as a control, also did not decrease the pepsinogen content.

4-Nitroquinoline-1-oxide↗
PubMed1980

A new antitumor enzyme, L-lysine alpha-oxidase from Trichoderma viride. Purification and enzymological properties.

L-Lysine alpha-oxidase from Trichoderma viride Y244-2 has been purified to homogeneity. The enzyme shows absorption maxima at 277, 388, and 466 nm and a shoulder around 490 nm and contains 2 mol of FAD/mol of enzyme. The enzyme has a molecular weight of approximately 116,000 and consists of two subunits identical in molecular weight (about 56,000). In addition to L-lysine, L-ornithine, L-phenylalanine, L-tyrosine, L-arginine, and L-histidine are oxidized by the enzyme to a lesser extent. Several lysine analogs such as delta-hydroxylysine are oxidized efficiently. Balance studies showed that 1 mol of L-lysine is converted to an equimolar amount of alpha-keto-epsilon-aminocaproate, ammonia, and hydrogen peroxide with the consumption of 1 mol of oxygen. alpha-Keto-epsilon-aminocaproate spontaneously is dehydrated intramolecularly into delta 1-piperideine-2-carboxylate in the presence of catalase, and is oxidatively decarboxylated into delta-aminovalerate in the absence of catalase. The Michaelis constants are as follows: 0.04 mM for L-lysine, 0.44 mM for L-ornithine, 14 mM for L-phenylalanine, and 1.6 mM for oxygen with L-lysine.

Amino Acid Oxidoreductases↗
PubMed1980

A new sesquiterpene antibiotic, heptelidic acid producing organisms, fermentation, isolation and characterization.

A new sesquiterpene antibiotic, heptelidic acid, was found in the culture filtrate of three different strains of fungi isolated from soil samples. These strains were identified as Gliocladium virens, Chaetomium globosum and Trichoderma viride. Heptelidic acid was produced by conventional submerged culture and purified by successive column chromatography on silica gel and Sephadex LH-20 and finally by preparative TLC on silica gel. The molecular formula of heptelidic acid was determined as C15H20O5 on the basis of elementary analysis and high resolution mass spectrometry of its monomethyl ester. The antimicrobial spectrum of the antibiotic revealed its specific activity against anaerobic bacteria, especially against Bacteroides fragilis.

Animals↗