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Biomedical subjects

Y Higuchi

Publications and source records attributed to Y Higuchi.

At least 325 records · Page 18Linked to original sources
PubMed1980

Solubilized bone morphogenetic protein (BMP) from mouse osteosarcoma and rat demineralized bone matrix.

A selection of proteins including bone morphogenetic protein (BMP) was extracted in a disaggregated form from Dunn osteosarcoma or rat demineralized bone matrix by 4M guanidine hydrochloride (GuHCl) solution without losing its biological activity. The GuHCl extracts of Dunn osteosarcoma were divied into 4 different fractions by cesium chloride (CsCl) density gradients. Under a dissociative condition, the highest new bone yield was obtained in the low dense top one-third fraction, and BMP acitivity declined with increase in the density of each fraction. No BMP potential was observed in the surface-gel fraction under dissociative conditions. Under an associative condition (low GuHCl concentrations), BMP activity appears in the surface-gel fraction, while under a dissociative condition (high concentrations of GuHCl) BMP appears in the fraction below the surface gel. These facts suggest that under associative conditions, BMP aggregates with other low dense proteins in the surface-gel fraction and that this may be the state of aggregation of BMP in cells and matrix in nature. Present observations support the assumption that BMP is a relatively low density protein and excludes the idea of BMP activity in the collagen molecule, per se. A specific protein, with an apparent molecular weight of 63,000 daltons, is present in all fractions that exhibit BMP activity, and absent in fractions that do not exhibit this activity. BMP is not species-specific; rat BMP induces bone formation in mice. CsCl density-gradient centrifugation is an efficient tool for further purification and isolation of BMP.

Animals↗
PubMed1980

Cytotoxic and cytolytic action of the subcellular fraction (60-F) of live hemolytic streptococci against Ehrlich ascites carcinoma cells.

The cytotoxic effect of 60-F, a subcellular fraction obtained from 0.5 approximately 0.6 saturation of cell-free extract of live hemolytic streptococci (Su-strain) with ammonium sulfate on Ehrlich ascites carcinoma cells was studied by the assay of incorporation of nucleosides and amino acid, and by the in vitro-in vivo cytocidal experiment. Additionally, the cytolytic effect of 60-F was examined by the assay of RNA and DNA released from the tumor cells. It was found that the tumor cells treated with 60-F did not take up thymidine, uridine, or leucine, that 60-F eradicated the transplantability of tumor cells in mice, and that 60-F released RNA but not DNA from the tumor cells.

Animals↗
PubMed1980

[The mechanism of anti-vascular permeability of 2-(2-fluoro-4-biphenylyl) propionic acid(Flurbiprofen) (author's transl)].

Effect of 2-(2-fluoro-4-biphenylyl) propionic acid(Flurbiprofen, FP-70) on increased vascular permeability was studied using the potentiation of bradykinin-induced vascular permeability by prostaglandin in the guinea pig skin, as the test system. Prostaglandin E1 or E2 (1 microgram/site) alone did not show increased vascular permeability but did enhance the effect of various concentrations of bradykinin when concomitantly applied, whereas prostaglandin F2 alpha did not potentiate the effect of bradykinin on vascular permeability. Arachidonic acid (100 microgram/site) had no effect on vascular permeability when injected alone or in combination with bradykinin. However, arachidonic acid enhanced the effect of bradykinin when given 30 min before bradykinin. FP-70 had no inhibitory effect on prostaglandin E1 potentiation of bradykinin-induced vascular permeability. On the other hand, FP-70 completely abolished the enhancement of the effect of bradykinin by arachidonic acid. These results strongly suggest that anti-vascular permeability action of FP-70 may be due to inhibition of prostaglandin synthetase. Indomethacin and acetylsalicylic acid also exhibit similar effects. However, the inhibitory effect of FP-70 was 12.5 and 166.7 times as potent as indomethacin and acetylsalicylic acid, respectively.

Animals↗
PubMed1980

Comparative experiments with hemolytic streptococcus and its anticancer preparations (OK-431 and OK-432) for their cytolytic activity.

The comparative in vitro cytolytic effects of living hemolytic streptococcus, a low virulent su-strain, and its streptococcal preparations (OK-431 and OK-432) on Ehrlich ascites carcinoma cells were investigated. It was shown that living cocci and OK-431 released 51Cr from 51Cr-labeled tumor cells by contact in vitro, but OK-432 did not release 51Cr at all. Moreover, the effects of living cocci, OK-431 and OK-432 were also examined by assay of the release of RNA and DNA from the tumor cells. It was confirmed that living cocci released RNA and DNA, but OK-431 released slightly RNA, not DNA from the tumor cells, whereas OK-432 did not cause these release at all. Consequently, it appeared that living cocci of Su-strain have more cytolytic activity than OK-431, and that OK-432 have no cytolytic activity in tumor cells.

Animals↗