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Biomedical subjects

T Nagumo

Publications and source records attributed to T Nagumo.

49 records · Page 3Linked to original sources

Myo-inositol transport in Saccharomyces cerevisiae.

myo-Inositol uptake in Saccharomyces cerevisiae was dependent on temperature, time, and substrate concentration. The transport obeyed saturation kinetics with an apparent Km for myo-inositol of 0.1 mM, myo-Inositol analogs, such as scyllo-inositol, 2-inosose, mannitol, and 1,2-cyclohexanediol, had no effect on myo-inositol uptake, myo-Inositol uptake required metabolic energy. Removal of D-glucose resulted in a loss of activity, and azide and cyanide ions were inhibitory. In the presence of D-glucose, myo-inositol was accumulated in the cells against a concentration gradient. A myo-inositol transport mutant was isolated from UV-mutagenized S. cerevisiae cells using the replica-printing technique. The defect in myo-inositol uptake was due to a single nuclear gene mutation. The activities of L-serine and D-glucose transport were not affected by the mutation. Thus it was shown that S. cerevisiae grown under the present culture conditions possessed a single and specific myo-inositol transport system. myo-Inositol transport activity was reduced by the addition of myo-inositol to the culture medium. The activity was reversibly restored by the removal of myo-inositol from the medium. This restoration of activity was completely abolished by cycloheximide.

Biological Transport, Active↗

Antitumor effect of seaweeds. II. Fractionation and partial characterization of the polysaccharide with antitumor activity from Sargassum fulvellum.

An almost purified antitumor polysaccharide fraction (SFPP) was obtained by fractional precipitation with ethanol from hot-water extract of Sargassum fulvellum. The fraction showed remarkable tumor-inhibiting effect against sarcoma-180 implanted subcutaneously in mice. The results of chemical and physical analyses suggested that the active substance may be either a sulphated peptidoglycuronoglycan or a sulphated glycuronoglycan.

Animals↗

[Successful treatment with vincristine for an elderly patient with idiopathic thrombocytopenic purpura].

A 77-year-old female was referred to our hospital in March 1991 because of a severe bleeding tendency. Her blood count on admission was as follows: Hb 7.5 g/dl, WBC 4.6 x 10(9)/l with normal differentiation and platelet 2 x 10(9)/l. One month prior to admission, her blood count was normal. Initially, acute idiopathic thrombocytopenic purpura (ITP) was suspected, because of the acute onset of the bleeding tendency and thrombocytopenia. High dose intravenous immunoglobulin (400 mg/kg/day for 5 days) and bolus methylprednisolone (1 g/day for 3 days then tapered) were administered, starting March 13. Her platelet count had increased immediately on March 20 to 40 x 10(9)/l. However, platelet count decreased to 4 x 10(9)/l in the following two weeks. Her clinical course differed from that of typical acute ITP. Because the treatment with prednisolone was not effective, it was changed to intravenous infusion of vincristine (VCR) at a weekly dose of 1 mg for 6 weeks. The treatment was extremely effective, and her platelet count reached over 200 x 10(9)/l. The treatment was discontinued. Three weeks later, her platelet count decreased to 15 x 10(9)/l, the administration of VCR was resumed, and her platelet count recovered again. Throughout her clinical course, no side effect of VCR was noticed except for mild hypesthesia of the fingertips. VCR therapy was considered to be an useful treatment in elderly patients with ITP.

Aged↗