Search PubMed⌕ Search

Biomedical subjects

S Toyama

Publications and source records attributed to S Toyama.

At least 145 records · Page 8Linked to original sources
PubMed1975

Scanning electron microscopic studies on the formation of cardiac intercellular connection in culture.

The fine surface structural appearance of the cardiac intercellular connection was studied scanning electron microscopically in culture. When individual heart cells contract each other, they start to beat synchronically. On the base of scanning electron microscopic observation, the early pattern of the formation of it could be suggested as follows: five ramified processes extend from the edge of the cells, and the ends of these processes bridge each other to form the intercellular connection.

Animals↗
PubMed1975

Energy metabolism in the infarcted cardiac muscle: the interaction of contractile protein and mitochondria.

In order to investigate the behavior of the energy-converting system in the myocardium, an experimental in vitro model was developed which consisted of contractile protein (myosin B) and mitochondria (Mit) prepared from canine cardiac muscle. In this system, ATP produced in Mit from added ADP caused the superprecipitation of the myosin B (My-B). One hour after the onset of experimental myocaridal infarction in the dog, the superprecipitation was very low in the system if Mit prepared from the infarcted myocardium were used, regardless of the origin of the myosin B. The respiratory control index of Mit prepared from infarcted was lower than that from noninfarcted myocardium, but the ADP:O ratio in Mit from infarcted myocardium, was little deteriorated. The findings indicate that a transferring process of an energy source from Mit to myosin B was markedly impaired in the infarcted myocardium. They also throw light on the mechanism by which the myocardium ceases its contraction at an early stage of infarction.

Animals↗
PubMed1972

Occurrence of taurine: -ketoglutarate aminotransferase in bacterial extracts.

High activity of taurine:alpha-ketoglutarate aminotransferase was found exclusively in cell-free extracts of Achromobacter superficialis and A. polymorph. The former was chosen for characterization of the enzymatic reaction. The enzyme activity was enhanced by addition of beta-alanine to the growth medium. The product from alpha-ketoglutarate was identified as l-glutamate. Another product has been isolated, purified, and identified as sulfoacetaldehyde (2-oxoethanesulfonate), a deamination product from taurine, by comparison between the 2,4-dinitrophenylhydrazones of the synthetic and enzymatic products on the basis of studies by paper chromatography, by visible, infrared, and nuclear magnetic resonance spectrophotometries, and by elemental analysis. This enzymatic transamination was found to proceed stoichiometrically and reversibly as follows: NH(2).CH(2).CH(2).SO(3)H + HOOC.CH(2).CH(2).CO.COOH right harpoon over left harpoon OHC.CH(2).SO(3)H + HOOC.CH(2).CH(2).CH(NH(2)).COOH.

Alanine↗