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T Ooshima

Publications and source records attributed to T Ooshima.

At least 109 records · Page 6Linked to original sources
PubMed1984

Virulence factors of Streptococcus mutans and dental caries prevention.

Streptococcus mutans possesses the abilities to adhere to pellicle-coated tooth surfaces and to form acids - two characteristics associated with the cariogenicity of this micro-organism. De novo synthesis of insoluble glucan by S. mutans glucosyltransferase from sucrose is essential in the adherence process. Therefore, agents which interfere with the adherence ability of S. mutans would be useful for controlling dental caries. In the present report, we have summarized our recent findings concerning virulence factors of S. mutans and means for prevention of S. mutans-induced dental caries.

Adhesiveness↗
PubMed1983

Non-cariogenicity of the disaccharide palatinose in experimental dental caries of rats.

The caries-inducing activity of palatinose (isomaltulose, alpha-D-glucopyranosyl-1,6-fructose) was examined in in vitro and in vivo experiments, comparing it with other carbohydrates. When Streptococcus mutans was successively subcultured in a broth medium containing 1% palatinose, the strains belonging to serotype a, d, or g did not ferment palatinose, whereas the strains belonging to serotype b, c, e, or f did ferment palatinose. Furthermore, palatinose significantly inhibited the synthesis of insoluble glucan from sucrose by S. mutans. Specific-pathogen-free rats which had been infected with S. mutans 6715 and fed a diet containing 56% palatinose did not develop significant dental caries. However, rats infected similarly, but fed a diet containing sucrose, glucose, fructose, or a glucose-fructose mixture manifested significant caries when compared with the noninfected, sucrose-fed control rats. Furthermore, it was found that replacement of half of the sucrose content with palatinose resulted in decreased caries development compared with caries development in rats fed the sucrose diet.

Animals↗
PubMed1983

Cariostatic effect of palatinose on experimental dental caries in rats.

Specific pathogen-free Sprague-Dawley rats infected with Streptococcus mutans MT8148R (serotype c) developed a severe dental caries when fed a diet containing 56% sucrose (diet #2000). Complete replacement of the dietary sucrose with palatinose, a structural isomer of sucrose, however, resulted in negligible caries induction and plaque accumulation. Replacement of half of the sucrose content of diet #2000 with palatinose induced dental caries; however, the caries score was significantly lower than that induced by diet #2000. No significant reduction in caries development was observed when a quarter of the dietary sucrose was replaced with palatinose.

Animals↗
PubMed1982

Minimum nutritional requirements for cellular growth and extracellular slime polysaccharide production by the human dental plaque bacterial mutant Actinomyces viscosus T14Av.

The requirements were examined in chemically-defined media. Magnesium sulphate, potassium phosphate and adenine were essential for cellular growth and sodium bicarbonate and inositol further stimulated growth. The addition of sodium phosphate to this medium stimulated both cellular growth and slime production. In contrast, ammonium sulphate inhibited slime production. Biotin and thiamine stimulated cellular growth and nicotinic acid was essential for slime production. Glutamine, alanine and cystine were essential for cellular growth. A minimal medium which supported both good cellular growth and slime production for strain T14Av contained adenine, sodium bicarbonate, MgSO4, inositol, glucose, KH2PO4, Na2HPO4, biotin, thiamine, nicotinic acid, arginine, glutamine, alanine and cystine.

Actinomyces↗
PubMed1981

Regulation of extracellular slime production by Actinomyces viscosus.

Extracellular slime polysaccharides produced two Actinomyces viscosus strains, T14V and T14AV, were compared. In various media containing glucose, T14Av produced abundant extracellular viscous slime polysaccharide, whereas T14V produced lower levels. Furthermore, fractionation of these polysaccharides showed that the two extracellular polysaccharides differed in molecular size and net charge. Since there was a significant difference in the relative abilities of chemically defined medium and chemically defined tissue culture medium to support slime production by T14Av, the nutritional factors influencing the production of extracellular slime were examined. Sodium bicarbonate was demonstrated to stimulate both cellular growth and the production of extracellular slime. In chemically defined medium with and without sodium bicarbonate, strain T14Av produced large quantities of viscous slime in glucose and sucrose media. In contrast, relatively low levels of slime were produced in fructose, lactose, raffinose, and inositol media, even though sodium bicarbonate stimulated the growth of T14Av in these latter media.

Actinomyces↗
PubMed1981

Susceptibility of rats, hamsters, and mice to carious infection by Streptococcus mutans serotype c and d organisms.

Susceptibility of rats, hamsters, and mice to carious infection by S. mutans serotypes c and d was compared. S. mutans serotype c induced a similar level of carious lesions at experimental periods of 68, 82, and 98 d in rats, hamsters, and mice, respectively. On the other hand, S. mutans serotype d developed a high level of caries at those experimental periods in rats and hamsters, whereas in mice it showed weak caries activity.

Animals↗