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Biomedical subjects

Y Okawa

Publications and source records attributed to Y Okawa.

At least 91 records · Page 5Linked to original sources
PubMed1984

Growth-inhibition of leukemia L-1210 ascites tumor by combination of carrageenan and mitomycin C in vivo.

A purified i-carrageenan prepared by means of pronase digestion and fractional precipitation with KCl was investigated for its growth-inhibitory effect on mouse leukemia L-1210 transplanted in (C57BL/6 x DBA/2)F1 (BDF1) mice. This carrageenan specimen was not growth-inhibitory on this tumor when it was administered alone in a dose of 0.1 to 10 mg/kg/d, 4 times. However, in combination, with a small amount of mitomycin C, 0.25 mg/kg/d, a remarkable tumor growth-inhibition has manifested affording a complete regression of this tumor. Acid phosphatase alpha-galactosidase and active oxygen generation activities of the peritoneal exudate cells in the carrageenan-administered mice were remarkably higher than those of the control mice. Therefore, the booster effect of this carrageenan preparation on antitumor activity of mitomycin C is assumed to be associated with the inflammatory activity of this sulfated polysaccharide.

Acid Phosphatase↗
PubMed1984

In vitro cytolysis of MM46 tumor cells by mouse phagocytes activated by acidic mannan fraction of bakers' yeast.

An acidic mannan from bakers' yeast designated as WAM025 was investigated for its augmentative effect on cytolytic activity of phagocytes obtained from the peritoneal cavity of C3H/He strain mice, which had been administered i.p. with this acidic polysaccharide, 150 mg/kg/d, 5 and 10 times. The result of assay for the cytolytic effect of WAM025-activated phagocytes by measuring the amounts of 3H-uridine of the MM46 tumor cells indicated that a marked lysis of the target cells took place by a 24-h incubation with the activated phagocytes and that a decrease of this effect was observed by the additions of either phagocytic inhibitors or active oxygen scavengers. Because generation of active oxygens from the WAM025-activated phagocytes was also diminished by the additions of the same inhibitors and scavengers, it indicated that active oxygens participated in an important role in the cytolytic effect displayed by the WAM025-activated phagocytes.

Animals↗
PubMed1983

Antitumor activity of acidic mannan fraction from bakers' yeast.

The acidic fraction of bakers' yeast mannan containing mannose (93.6%), nitrogen (1.0%), and phosphorus (0.6%), designated as WAM025, showed a marked antitumor activity against the ascites forms of Ehrlich, sarcoma 180 and Meth A tumors in vivo. Namely, a 100% survival of mice transplanted with Ehrlich or sarcoma 180 ascites tumor, 1 X 10(5) cells/ddY strain mouse, was obtained by the intraperitoneal administration of WAM025, 150 mg/kg/d for 10 d. This effect evoked by WAM025 seems to be attributed to the activation of peritoneal adherent cells in mice, because a significant elevation of lysosomal enzyme level and active oxygen generation was observed on the peritoneal adherent cells obtained from the mannan-administered mice.

Animals↗
PubMed1982

Acute functional changes of platelets in left ventricular assist in a dog model.

Left ventricular assist bypass was performed in nine dogs using pneumatically actuated blood pumps fabricated of segmented polyurethane and heparinized hydrophilic polyurethane (H-USD) newly developed so as to render excellent antithrombogenicity. The survival of the dogs ranged from 1 to 82 days. In all cases, significant reductions in platelet count and in platelet aggregability were observed. Simultaneously, severe hemorrhage from the anastomosed descending aorta occurred four to six hours after the pump implantation. This hemorrhage, leading to death, was not related to systemic heparinization, but was closely related to the mechanical impairment of platelets by the pumping operation. Five days after the pump implantation, complete recovery of the platelet aggregability was observed and no further hemorrhage occurred in the dog that survived for 82 days.

Animals↗
PubMed1979

on the extracellular sheath of dermal melanocytes in nevus fusco-ceruleus acromiodeltoideus (Ito) and Mongolian spot. An ultrastructural study.

The dermal melanocytes in the lesions of nevus of Ito and Mongolian spot were shown to possess the extracellular sheath composed of both fine filaments and granules (2-5 nm in diameter). In the case of nevus of Ito, the granular component appeared to predominate in the shealth, which measured up to 3 micrometers in width and was estimated to cover about 97% of the total surface of dermal melanocytes. No ultrastructural changes were appreciable on the melanocyte shealth in nevus of Ito according to the difference in the age of patients (39 and 64 years), or in the lasting period of the dermal melanocytosis. By contrast, the melanocyte sheath in the case of Mongolian spot was much less developed than in nevus of Ito, predominantly filamentous in texture, and showed a marked decline with advance of the age of infants (from 2 mo to 6 yr). Many of the dermal melanocytes in Mongolian spot showed a partial disruption of their cytolemma, resulting in discharges of melanosomes free into the connective tissue matrix. Significance of these findings was discussed in relation to the differtial fate of melanocytes within the human dermis.

Adult↗
PubMed1977

Studies on sterol-ester hydrolase from Fusarium oxysporum. I. Partial purification and properties.

1. A search for a long chain fatty acyl sterol-ester hydrolase in microorganisms led to the isolation from soil of five strains belonging to Fusarium sp. which produced strong activity in the culture medium. 2. The cholesterol esterase from Fusarium oxysporum IGH-2 was purified about 270-fold by means of CaCl2 precipitation and Sephadex G-75 column chromatography. 3. The cholesterol esterase was activated by adekatol and Triton X-100. It was inhibited by lecithin and lysolecithin, and completely inactivated by heat treatment (60 degrees C for 30 min, at pH 7.0). 4. The optimum pH of the enzyme was found to be around 7.0. 5. Among various cholesterol esters tested, cholesterol linoleate was the most suitable substrate. 6. Cholesterol esters in serum were also hydrolyzed by this enzyme.

Carbohydrates↗