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Biomedical subjects

M Ogata

Publications and source records attributed to M Ogata.

At least 595 records · Page 33Linked to original sources
PubMed1979

Sampling and analysis of organic solvent vapours--with special reference to sampling tubes for a short time and for the working period.

The present paper concerns the sampling and analysis of organic solvent vapours for a short period of time and for the working period. Porous polymer beads, Porapak Q, was applied to the adsorbent of the sampling tube for mixed vapours of aromatic compounds (benzene, toluene and xylenes). The adsorbent was packed in stainless steel column of a suitable size, and the adsorbed vapours were released by heating in the flasher then analysed by gas chromatography. The concentrations of the mixed vapours could be measured simultaneously with sufficient recoveries at the ordinary concentrations in the working yeard. The sampling conditions by pumps and the practical recoveries were tested. Being sucked with the vacuum pump using a Gastek detection tube (100 ml), the recoveries proved to be almost 100%. Being sucked with portable diaphragmatic pumps at a slow flow rate (22 ml/min), the recoveries were constant with only small variations. At a relatively fast flow rate (220-230 ml/min), the recoveries were not so high as those at the slow flow rate. These findings indicate that the sampling tube with Porapak Q is useful for aromatic compounds not only as a room air sampler for a short period of time but also as a personal air sampler.

Air Pollutants↗
PubMed1979

Effect of chinoform on the function of biological membranes.

To investigate the mechanism by which the toxic effect of chinoform (5-chloro-7-iodo-8-quinolinol) develops, its action on the function of biological membranes was examined. Findings were: 1. Chinoform induced K+ release from red cells. This effect was increased by prior addition of Mg2+ and decreased by albumin, ruthenium red, or lanthanum chloride. 2. Chinoform induced K+ release from isolated rat liver mitochondria more effectively in the presence of Mg2+ or other bivalent cations, and a chinoform-Mg chelate was more effective than chinoform alone. The K+ release from mitochondria was protected by albumin and to a certain extent by lanthanum chloride. 3. The change in the ion permeability of mitochondrial membrane induced by chinoform in the presence of Mg2+ was accompanied by uncoupling of the oxidative phosphorylation. These results suggest that chinoform interacts with membranes more effectively as a metal chelate, producing conformational and functional changes in those membranes.

Animals↗
PubMed1979

Differences in urinary trichloroethylene metabolites of animals.

Differences in urinary excretion of trichloroethylene were studied in rabbits, rats and mice. Trichloretylene (1 m mole/kg) was injected intra-peritoneally, then urinary trichloroacetic acid and trichloroethanol glucuronide were measured. The results were: 1. The ratio of total excretion of trichloroethylene metabolites to the administered trichloroethylene decreased in the order of mice, rats and rabbits. 2. The ratio of total trichloroethanol to trichloroacetic acid in urine decreased in the order of rabbits (69.2), mice (12.8) and rats (2.3). The high ratio in rabbits was due to the extremely small amount of trichloroacetic acid in the urine. 3. Differences in these two urinary metabolites in the three kinds of animals and in human subjects were discussed.

Animals↗
PubMed1979

Quantitative determination of urinary trichloroacetic acid as an index of trichloroethylene exposure by high performance liquid chromatography.

A high performance lipuid chromatographic method for the determination of urinary trichloroacetic acid, a metabolite of trichloroethylene, is described. A stainless steel column packed with Hitachi gel 2618 (H form) was used and the mobile phase was one per cent aqueous phosphoric acid. Urine can be analyzed directly without any solvent extraction or pretreatment. The minimal detection limit was 0.5 micrograms per analysis. The present method is simple and specific, and can be performed within 10 min.

Chromatography, High Pressure Liquid↗
PubMed1979

Properties of erythrocyte catalase from heterozygotes for Japanese type acatalasemia.

The level of blood catalase activity in heterozygotes for Japanese type acatalasemia was demonstrated to be about half of normal levels by means of titration and spectrophotometric methods. A distribution plot of catalase activities in heterozygous blood was completely separate from that of normal blood. Comparative analysis of the partially purified erythrocyte catalase preparations obtained from normal and heterozygous individuals revealed no distinct differences between them regarding stability to heat, sodium dodecyl sulfate and some enzyme inhibitors or pH dependency. The erythrocyte catalase in heterozygotes for Japanese type acatalasemia contains about half the normal specific activity and as stable as that in normal individuals.

Acatalasia↗
PubMed1978

Enzymic hydrolysis of diol lipids by pancreatic lipase.

Chain length and positional specificities of pancreatic lipase for diol lipids have been examined by use of the synthetic substrates such as the diol esters and related esters that contain C6--C20 even-numbered saturated acids and oleic acid as fatty acids, and ethylene glycol, 1,2- and 1,3-propanediols, 1,3-, 1,4-, and 2,3-butanediols, monohydric alcohols, and glycerol as alcohols. No remarkable difference in the degree of hydrolysis was observed in the case of diol esters having C14--C20 fatty acids at least during 30-min digestion, though hydrolysis reached a maximum in diol diotanoates after the same period. Pancreatic lipase specifically released only the fatty acids esterified with the primary hydroxyl groups of diols.

Animals↗