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M Torii

Publications and source records attributed to M Torii.

15 recordsLinked to original sources
PubMed1992

Lipid peroxidation and myocardial vulnerability in hypertrophied SHR myocardium.

In a comparison using age-matched Wistar-Kyoto rats (WKY), 16-week-old male spontaneously hypertensive rat (SHR) hearts were examined histologically and biochemically on the first and fourth day after administration of 20 mg/kg doxorubicin in order to examine whether membrane abnormalities in hypertrophied SHR myocardium are caused by lipid peroxidation. Morphological examination of the SHR revealed focal myocytolysis on the first day and severe cardiomyopathy involving diffuse myocytolysis and vacuolar degeneration in the left ventricle on the fourth day. The activity of a membrane-related enzyme, Na+/K(+)-ATPase, was already lower in control SHR than that of control WKY and was lower in both SHR and WKY than in the respective saline groups on the first day after administration, whereas the enzyme activity in the doxorubicin-treated SHR was not significantly different from that of the treated WKY. A thiobarbituric acid-reactant substance, a lipid peroxidation marker, was significantly higher in treated SHR than it was in the treated WKY on the first day. Furthermore, in comparison with WKY, alpha-tocopherol in the left ventricle in SHR was significantly lower on the fourth day after administration. These results show that a proneness to lipid peroxidation in the membrane system is closely associated with severity of doxorubicin-induced cardiomyopathy in SHR and suggests that membrane lipid peroxidation may cause a higher degree of vulnerability in hypertrophied SHR myocardium.

5'-Nucleotidase↗
PubMed1992

A comparative study on defense systems for lipid peroxidation by free radicals in spontaneously hypertensive and normotensive rat myocardium.

1. Antiperoxidation ability and lipid peroxidation in myocardium were examined in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) at 6 and 16 weeks of age. 2. Glutathione peroxidase activity was higher in SHR at 6 weeks of age, but lower at 16 weeks compared to that in WKY. alpha-Tocopherol content was lower in SHR at both 6 and 16 weeks of age than in WKY. 3. In vitro formation of free malondialdehyde was more pronounced in SHR myocardium than in WKY. 4. Coincidence of lower antiperoxidation ability and higher peroxidation of membrane phospholipid indicate myocardial cell vulnerability in SHR hypertrophied myocardium.

Aging↗
PubMed1992

Fall in skin temperature of exercising man.

Fall in skin temperature during initial muscular work was investigated in ten healthy men. Bicycle exercise was performed at workloads of 50-150 W in a climatic chamber at ambient temperatures of 10-40 degrees C (relative humidity 45-55%). Skin temperatures at seven or eight points over the body surface were measured using thermography and thermocouple recording systems. Sweat rates were significantly higher at 40 degrees C than at 30 degrees C, whereas the fall in skin temperature was almost equal. The reduction of skin temperature during exercise was the same throughout the year, although sweat rate was significantly higher in summer than in winter. In coloured thermographics of the skin temperature distribution during exercise of both 50 and 150 W at 10 or 20 degrees C, the skin temperature began to decline immediately at the onset of the exercise. Increased work intensities reduced skin temperature. The results suggest that fall in skin temperature during initial exercise was not due to increased evaporative cooling but to vasoconstriction, probably caused by non-thermal factors.

Bicycling↗
PubMed1991

Comparison of immunochemical specificities of Vibrio parahaemolyticus O10 and O12 antigens using monoclonal antibodies.

The monoclonal antibodies against Vibrio parahaemolyticus O10 and O12 antigens (lipopolysaccharide, LPS) were prepared and specificities of the antibodies were examined. Five of six anti-O10 antibodies reacted with O10 antigen, but none of them reacted with O12 antigen. On the contrary all of the five anti-O12 antibodies reacted with O10 antigen as well as homologous O12 antigen. O10 and O12 antigens were subjected to alkali treatment or periodate oxidation, and reactivities of these chemically modified preparations with the monoclonal antibodies were examined. Reactivities of O10 with anti-O10 and anti-O12 antibodies were reduced by the above two chemical treatments, but that of O12 with anti-O12 was not. O-Deacetylation of O10 LPS by the alkaline treatment was confirmed by NMR spectroscopy. These results suggest contributions to O10-specificity of O-acetyl group and periodate sensitive sugar residue. Inhibition experiments of O10 and O12 homologous precipitations were also carried out with various sugars. From the results we concluded that O10 and O12 antigenic determinants were distinct entities, although O10 and O12 antigens have been reported to be similar and cross-reactive.

Antibodies, Monoclonal↗
PubMed1979

Preparative use of the analytical column of a sugar autoanalyzer for resolution of gluco-oligosaccharides of the same molecular weight.

A sugar autoanalyzer was used on a preparative scale to resolve a gluco-oligosaccharide mixture. In this way the components of the following mixtures were resolved: O-alpha-D-glucopyranosyl-(1-3)-O-[alpha-D-glucopyranosyl-(1-6)]-D-glucose (1), O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-3)-D-glucose (2) and O-alpha-D-glucopyranosyl-(1-3)-O-alpha-D-glucopyranosyl-(1-6)-D-glucose (3), O-alpha-D-glucopyranosyl-(1-3)-O-alpha-D-glucopyranosyl-(1-4)-D-glucose (4) and O-alpha-D-glucopyranosyl-(1-4)-O-alpha-D-glucopyranosyl-(1-3)-D-glucose (5), and O-alpha-D-glucopyranosyl-(1-2)-O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-6)-D-glucose (6) and O-alpha-D-glucopyranosyl-(1-3)--O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-6)-D-glucose (7).

Autoanalysis↗
PubMed1978

Dental caries induction in experimental animals by clinical strains of Streptococcus mutans isolated from Japanese children.

Oral implantation and the cariogenic activity of clinical strains of Streptococcus mutans which had been isolated from Japanese children and labeled with streptomycin-resistance were examined in specific pathogen-free Sprague-Dawley rats. All the seven strains tested were easily implanted and persisted during the experimental period. Extensive carious lesions were produced in rats inoculated with clinical strains of S. mutans belonging to serotypes c, d, e, and f, and maintained on caries-inducing diet no. 2000. Noninfected rats did not develop dental caries when fed diet no. 2000. Type d S. mutans preferentially induced smooth surface caries in the rats. Strains of other serotypes primarily developed caries of pit and fissure origin. Caries also developed in rats inoculated with reference S. mutans strains BHTR and FAIR (type b) that had been maintained in the laboratories for many years. However, the cariogenicity of the laboratory strains was found to have decreased markedly. All three S. sanguis strains could be implanted, but only one strain induced definite fissure caries. Two S. salivarius strains could not be implanted well in the rats and therefore they were not cariogenic. Four different species of lactobacilli also failed to induce dental caries in rats subjected to similar caries test regimen on diet no. 200. S. mutans strain MT6R (type c) also induce caries in golden hamsters and ICR mice, but of variable degrees.

Animals↗
PubMed1978

Effect of sucrose in culture media on the location of glucosyltransferase of Streptococcus mutans and cell adherence to glass surfaces.

Streptococcus mutans strain B13 (serotype D) almost exclusively produced free glucosyltransferase (GTase) in the culture supernatant when grown in sucrose-free TTY broth medium, which was composed of Trypticase (Baltimore Biological Laboratory [BBL] Cockeysville, Md.), tryptose (Difco Laboratories, Detroit, Mich.), yeast extract (BBL), salts, and 1% glucose. Organisms grown in sucrose-free TTY broth retained very weak cell-associated GTase activity and did not adhere significantly to glass surfaces in the presence of exogenous sucrose. If sucrose was added to TTY broth, however, GTase was found on the cell surface where cell-bound, water-insoluble glucans were synthesized. Most commercially available products of Todd-Hewitt broth were found to contain trace amounts of sucrose, as did Trypticase soy broth (BBL), whereas brain heart infusion broth (Difco and BBL) was found to be essentially free of sucrose. Almost all detectable GTase activity was cell associated when S. mutans B13 was grown in Todd-Hewitt or trypticase soy broth. Heat-treated B13 cells grown in Todd-Hewitt broth and cell-free, water-insoluble glucans bound free GTase and produced marked adherence in the presence of sucrose. Experiments strongly suggest that the binding sites for free GTase are the surface glucans, and cell-associated and extracellular GTases are most likely alternate states of the same enzyme protein.

Culture Media↗
PubMedDate not supplied

Penetration of the mosquito (Aedes aegypti) midgut wall by the ookinetes of Plasmodium gallinaceum.

We observed Plasmodium gallinaceum ookinetes in both intracellular and intercellular positions in the midgut epithelium of the mosquito Aedes aegypti. After epithelial cell invasion intracellular ookinetes lacked a parasitophorous vacuolar membrane and were surrounded solely by their own pellicle. Thus, the ookinete in the midgut epithelium of the mosquito differs from erythrocytic and hepatic stages in that the parasite in the vertebrate host is surrounded by a vacuole. The midgut epithelial cytoplasm around the apical end of invading ookinetes was replaced by fine granular material deprived of normal organelles. Membranous structure was observed within the fine granular area. Most ookinetes were seen intracellularly on the luminal side and intercellularly on the haemocoel side of the midgut epithelial cells. These observations suggest that the ookinete first enters into the midgut epithelial cell, then exists to the space between the epithelial cells and moves to the basal lamina where the ookinete develops to the oocyst.

Aedes↗