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Biomedical subjects

S Oikawa

Publications and source records attributed to S Oikawa.

At least 253 records · Page 14Linked to original sources

Effect of a polysaccharide fraction from Grifola frondosa on immune response in mice.

The biological and immunomodulating activities of polysaccharide fraction (GF-1), an antitumor poysaccharide fraction from cultured fruiting bodies of Grifola frondosa, was examined in mice. GF-1 showed no cytocidal effect on culturing tumor cells. However, GF-1 induced resistance against Sarcoma 180 in ICR mice which had completely regressed from the tumor by the effect of GF-1. The administration of GF-1 into mice increased the weights or cell numbers of spleen, and peritoneal cavity. GF-1 enhanced the antigen specific antibody response and carbon clearance activity, whereas GF-1 did not show polyclonal B cell activation and mitogenic activities, and the effect on delayed type hypersensitivity.

Animals↗

ApoE-2/E-3 ratio of very low density lipoprotein in diabetes mellitus.

Apolipoprotein E (apoE) of very low density lipoprotein (VLDL) in 22 diabetic patients was analysed by the method of one-dimensional isoelectrofocussing (IEF). We modified the IEF-method of Kashyap et al. by which apoE isoproteins were easily and accurately determined. The measurement of apoE-2/E-3 ratio was useful for determining apoE phenotypes. In 17 of 22 diabetics apoE phenotype was E3/3, while three patients showed E2/3 and two showed E3/4. ApoE-2/E-3 ratio was reduced from 0.91 +/- 0.07 to 0.73 +/- 0.04 (p less than 0.05) by the one month-period treatment in 10 insulin required diabetics. The ratio was also reduced from 1.06 +/- 0.14 to 0.89 +/- 0.09 (p less than 0.2) in 10 non-insulin required diabetics. The reduction in apoE-2/E-3 ratio was caused by an increase in apoE-3 band and a decrease in apoE-2 band which might be attributed to the changes in the sialic acid-content of isoproteins on the one-dimensional IEF method. Therefore, apoE phenotypes in diabetic patients should be determined when their diabetic state is improved.

Adult↗

Evidence for direct effect of growth hormone on capillary basement membrane thickness.

In order to investigate the direct effect of growth hormone on the capillary basement membrane thickness (CBMT), we performed, in normal and diabetic rats, ultrastructural morphometric studies on the capillaries of the skin loci where the intracutaneous injections of physiologic saline and human growth hormone (HGH) in various concentrations had been repeated daily for 28 days. In the normal group, the injection (0.1 ml daily) of HGH solutions in concentrations of 0.5 micrograms/ml and 2 micrograms/ml did not significantly alter the CBMT, and only at the concentration of 10 micrograms/ml, HGH significantly (p less than 0.001) increased the CBMT. In the diabetic group, however, the injection of any of the HGH solutions significantly (p less than 0.001 approximately 0.05) increased the CBMT. In another diabetic rat series, HGH, human albumin, human menopausal gonadotropin and human globulin (each in a concentration of 10 micrograms/ml) were repeatedly injected into four separate skin portions for 28 days, and it was found that the net increase in CBMT was most striking in the HGH-treated portion. These data demonstrated the direct and specific effect of HGH on CBMT.

Animals↗

Antitumor activity of a polysaccharide fraction extracted from cultured fruiting bodies of Grifola frondosa.

Antitumor activity of a polysaccharide fraction (GF-1) extracted from cultured fruiting bodies of a fungus, Grifola frondosa, was examined on allogeneic and syngeneic tumors in mice. GF-1 had a marked inhibitory activity against the growth of subcutaneously (s.c.) inoculated Sarcoma 180 by the intraperitoneally (i.p.) injection at 0.5-5.0 mg/mouse for 10 successive days. A significant antitumor activity was also observed when GF-1 at 4.0 mg/mouse was i.p. injected successively on days +1-+5, +7-+11, +14-+18 or +21-+25 if the tumor cells were inoculated s.c. on day 0. Similar results were obtained by a single i.p. injection of GF-1 at 2.0 mg/mouse on day +1, +7, +14 or +21. When GF-1 was injected i.p., intravenously (i.v.) or intratumorally (i.t.), all of them showed an equivalent level of higher inhibitory activity (inhibition ratio; over 90%). However, the oral (p.o.) administration was not effective. The pretreatment of mice with GF-1 at 2.0 or 4.0 mg/mouse for 5 times before tumor inoculation did not show a significant antitumor activity. In addition, GF-1 administered i.p. at varying times before and/or after the tumor inoculation showed no antitumor activity against ascites form of Sarcoma 180. In the syngeneic systems, GF-1 exhibited an antitumor activity against solid form of Meth A fibrosarcoma in BALB/c mice and MM46 carcinoma in C3H/He mice.

Animals↗

Expression in Escherichia coli of chemically synthesized gene for a novel opiate peptide alpha-neo-endorphin.

Chemically synthesized alpha-neo-endorphin gene was fused to the Escherichia coli beta-galactosidase gene on the plasmid pKO13. The resulting recombinant DNA was used to transform E. coli cells. Radioimmunoassay for alpha-neo-endorphin in CNBr-treated bacterial cells showed that alpha-neo-endorphin was synthesized at approximately 5 x 10(5) molecules per single E. coli cell. One of the transformants, WA802/p alpha NE2, was used for alpha-neo-endorphin purification. From 10.9 g of wet cells, we isolated 4 mg of chemically pure and biologically active alpha-neo-endorphin.

Amino Acid Sequence↗

Inhibitory effect of pancreatic elastase on thickening of the renal glomerular basement membrane in the spontaneously diabetic rat.

Effect of pork pancreatic elastase on thickening of the renal glomerular basement membrane was studied in three litter mates of the spontaneously diabetic rats by electron microscopic morphometry. Intramuscular injection of physiologic saline solution or elastase solution (5 mg/kg body weight/day) was repeated daily for 30 days. Renal cortex specimens were obtained before and after the injection in two litter mates. Renal glomerular basement membrane thickness (RGBMT) of the rats injected with saline increased markedly, whereas RGBMT of the rats treated with elastase remained close to the initial value. In each of the three litter mates, RGBMT after the treatment was significantly thinner in the elastase injected rats than in the saline injected rats.

Animals↗

Effect of insulin on the lysosomal function of rat aortic smooth muscle cells and subcutaneous fibroblasts in tissue culture.

Extracellular and intracellular activities of N-acetyl-beta-glucosaminidase (NAG), a representative lysosomal enzyme, in rat aortic smooth muscle cells and subcutaneous fibroblasts cultured for 6 days with an insulin-enriched (200 microU/ml of insulin) or an insulin-deprived medium were measured. The culture medium was changed every 2 days. The net release of NAG into the medium between the 4th and the 6th day was significantly inhibited in the insulin-enriched culture of both smooth muscle cells and fibroblasts. The inhibition was more marked in the fibroblasts series than in the smooth muscle cell series. On the other hand, the intracellular NAG activity of both cell series was almost similar in the insulin-enriched culture and in the insulin-deprived culture. The results indicate that insulin has an inhibitory effect on the net extracellular release of NAG and, therefore, regulates the lysosomal function in these mesenchymal cells.

Acetylglucosaminidase↗