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Biomedical subjects

H Morishima

Publications and source records attributed to H Morishima.

At least 73 records · Page 4Linked to original sources
PubMed1989

Mannostatins A and B: new inhibitors of alpha-D-mannosidase, produced by Streptoverticillium verticillus var. quintum ME3-AG3: taxonomy, production, isolation, physico-chemical properties and biological activities.

Mannostatins have been isolated as part of a program designed to find microorganism-produced inhibitors of alpha-D-mannosidase from Streptoverticillium verticillus var. quintum. They were purified by sequential use of active carbon and Dowex resins and then isolated as colorless powders. Mannostatins A and B have the molecular formula, C6H13NO3S and C6H13NO4S, respectively. They were competitive with the substrate, and the inhibition constants (Ki) of mannostatins A and B were 4.8 x 10(-8) M.

Cyclopentanes↗
PubMed1987

Europium-152 depth profile of a stone bridge pillar exposed to the Hiroshima atomic bomb: 152Eu activities for analysis of the neutron spectrum.

The 152Eu activity depth profile of a granite pillar of the Motoyasu bridge located 132 m from the Hiroshima atomic bomb hypocenter was assessed. The pillars each measured 82 cm in depth, 82 cm in width and 193 cm in height. One of the pillars was bored and 6.8-cm-diameter core samples were removed and cut into 2-cm-thick disks. Two gamma rays of 152Eu, 122 keV and 344 keV, in each disk were measured using a low background, gamma-ray spectrometer, and the activity distribution was determined as a function of depth in the granite. A concentration of stable Eu in the granite was determined by activation analysis. The specific radioactivity of 152Eu and 154Eu at the pillar surface was determined to have been 117 and 24 Bq per mg Eu, respectively, at the time of detonation. The value of 152Eu agrees within 20% of that calculated by Loewe. The depth profile of 152Eu in granite demonstrates a distinct difference from the estimates made only by thermal neutrons. Present data provide valuable information for the analysis of the neutron spectrum of the Hiroshima atomic bomb and its intensity.

Europium↗
PubMed1985

Vanoxonin, a new inhibitor of thymidylate synthetase. II. Structure determination and total synthesis.

Acid hydrolysis of vanoxonin yielded one mol each of 2,3-dihydroxybenzoic acid, L-threonine, L-N omega-hydroxyornithine. Presence of acetyl group in vanoxonin was suggested by the 1H NMR. Periodate oxidation of vanoxonin liberated one mol of acetic acid suggesting that the acetyl group bound to the omega-nitrogen of N omega-hydroxyornithine. The sequence of three components was determined to be L-N-(2,3-dihydroxybenzoyl)threonyl-L-(N omega-acetyl-N omega-hydroxy)ornithine by mass spectrometric analysis. This structure was confirmed by the total synthesis of vanoxonin.

Dipeptides↗
PubMed1985

Vanoxonin, a new inhibitor of thymidylate synthetase. III. Inhibition of thymidylate synthetase by vanoxonin-vanadium complex.

Quinquevalent vanadium complex with two mol of vanoxonin ligated by the two catechols was shown to be the active structure for inhibition of thymidylate synthetase. The catechol group of vanoxonin as the essential moiety for the inhibition of enzyme was further confirmed by studies of structure-activity relationships using the enzyme obtained from Ehrlich ascites carcinoma cells of mice. Vanoxonin-vanadium complex showed competitive inhibition with respect to deoxyuridylic acid but uncompetitive to 5,10-methylenetetrahydrofolate.

Dipeptides↗
PubMed1984

Effect of Eimeria tenella infection in chickens fed the feed artificially contaminated with Salmonella typhimurium.

Effect of Eimeria tenella infection on Salmonella typhimurium infection of chickens was tested using feed experimentally contaminated with S. typhimurium. Four experiments were conducted. In Experiments 1 and 2, chickens received feed contaminated with 10(3) or 10(2) cfu of S. typhimurium per g for 5 days after E. tenella infection. In Experiments 3 and 4, chickens were fed feed contaminated with 10(2) or 10 cfu of S. typhimurium per g for 3 days before E. tenella infection. In all experiments, chickens were necropsied 3 to 14 days after E. tenella infection. The number of S. typhimurium in the cecal contents was counted and the presence of the organism in the liver and bile was examined. In Experiments 1 and 2, there was no significant difference in S. typhimurium infection between the group infected with S. typhimurium alone and the group infected with both E. tenella and S. typhimurium. In Experiments 3 and 4, S. typhimurium counts in the cecal contents of chickens in the concurrently infected group were significantly greater than those of chickens in the S. typhimurium alone-infected group.

Animals↗