Biomedical subjects

M Itoh-Andoh

Publications and source records attributed to M Itoh-Andoh.

4 recordsLinked to original sources

PubMed1992

Mechanism of water-insoluble glucan synthesis in Streptococcus sobrinus.

Synthesis of water-insoluble glucan (IG) by 1,3-alpha-D-glucan synthase from Streptococcus sobrinus was examined using methylation analysis. The purified enzyme was incubated with sucrose and dextran T2000 (DT2000) for a given time and only IG was harvested by centrifugation. The remaining supernatant was incubated again, and IG was obtained. By repeating the above method using the residual supernatant, we obtained 5 varieties of IG precipitated in different periods. These IGs were methylated and examined using gas chromatograph mass spectrometry. The DT2000 water-insolubilized in the early reaction stage tended to have a highly ramified structure, with 1,3-alpha-D-glucan on a 1,6-alpha-D-glucan chain as the main chain. On the contrary, the DT2000 water-insolubilized in the late stage tended to have sparse side chains of 1,3-alpha-D-glucan which elongated with incubation. Specifically, the greater the number of side chains, the sooner the DT2000 was insolubilized. These results suggest that water-insolubilization of the water-soluble glucan not only depends on the increase of the ratio of 1,3-alpha-glucoside linkages to 1,6-alpha-glucoside linkages but also on the degree of branching of the 1,3,6-alpha-branched glucoside linkages.

Glucans↗

PubMed1990

Learning efficiency of a toothbrush for mastering scrubbing method.

Toothbrushing with long horizontal strokes often causes traumatization of sound enamel and gingival tissues. Also, dental plaque on cervical and adjacent surfaces of teeth can hardly be removed because toothbrush tips cannot reach these regions adequately. A toothbrushing device which indicates overstroke was tested to determine the efficacy with which it makes subjects master brushing with short horizontal strokes following an initial period of instruction. The degree of learning measured in the testing group was superior to that of the control group immediately after the first instruction. Moreover after one week and 12 weeks, its efficacy persisted. The plaque elimination ratio, however, showed no significant difference between the testing group and the control.

Adult↗

PubMed1989

Evidence for the presence of two distinct sites of sucrose hydrolysis and glucosyl transfer activities on 1,3-alpha-D-glucan synthase of Streptococcus mutans.

1,3-alpha-D-Glucan synthase of Streptococcus mutans catalyzes both the hydrolysis of sucrose to glucose and fructose, and the glucosyl transfer to glucosyl polymers to yield water-insoluble glucan. The enzyme catalyzes only sucrose hydrolysis, however, in the absence of 1,6-alpha-D-glucan as an acceptor. In the present study, we found that glucosyl transfer activity was completely inhibited by the antiserum against isolated 1,3-alpha-D-glucan synthase but that the sucrose hydrolysis activity was not. The antiserum did not impair the binding of the enzyme to the acceptor. These findings indicate that sucrose hydrolysis and glucosyl transfer occur at two distinct sites on the enzyme.

Binding Sites↗

PubMed1988

Prevalence and treatment needs of periodontal disease in employees of supermarkets in Japan.

In 1987, a survey was carried out to determine the prevalence and treatment needs of periodontal diseases in 2,684 (997 males and 1,687 females) employees of 57 supermarkets in Japan. The aim of this survey was to obtain fundamental data for planning preventive programs for periodontal diseases in the Japanese population. Most of the subjects showed some signs of periodontal disease. The percentages of persons having pathologic pockets 4 mm or deeper increased with age, and reached about 50% in the 45- to 64-year-olds. The percentage of persons affected was similar between the males and females, but the percentage of persons having pathologic pockets tended to be higher in the males than in the females. These findings indicate that the prevalence of periodontal diseases is extremely high among the Japanese population, and that primary prevention of periodontal disease during school days is required in order to maintain the adults' periodontal health.

Adolescent↗