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Biomedical subjects

Y Fujino

Publications and source records attributed to Y Fujino.

At least 253 records · Page 14Linked to original sources

HLA antigens in Behçet's disease with refractory ocular attacks.

HLA class I, II, and III antigens were studied in Japanese patients with Behçet's disease with refractory ocular attacks. In addition to the increased frequency of B51, DQw3, especially TA10-negative DQw3, was increased and DQw1 was decreased significantly in this subgroup of Behçet's disease. As for complement markers, C4A Q0 was increased. A rare variant of BF S07 was first observed in Japanese. Although the mechanism for the DQw3 association is obscure, a possible hypothesis is that an immune-response or immune-suppression gene linked to the DQ antigens modulates the disease severity and the efficacy of treatments.

Behcet Syndrome↗

Distributions of H+,K+-ATPase and Cl-,HCO3(-)-ATPase in micromere-derived cells of sea urchin embryos.

In cultured cells derived from isolated micromeres of sea urchin eggs, H+,K+-ATPase activity, which became detectable simultaneously with the initiation of spicule formation, was localized in the plasma membrane and the microsome fractions. Activities of marker enzymes for plasma membrane, 5'-nucleotidase, Na+,K+-ATPase, and adenylate cyclase, were found to be high in the plasma membrane fraction. Considerable activity of rotenone-insensitive NADPH-cytochrome c reductase, a marker enzyme for microsome, was detectable in the microsome fraction. These fractions exhibited barely any appreciable activity of markers for the other organellae. H+,K+-ATPase in plasma membrane probably mediates H+ release from the cells, in which H+ is produced in overall reaction to form CaCO3, the main component of spicules, from Ca2+, CO2 and H2O. Cl-,HCO3(-)-ATPase activity was also found in these two fractions before and after the initiation of spicule formation. After initiation, the skeletal vacuole fraction was obtained from subcellular structures containing spicules. Considerable activity of Cl-,HCO3(-)-ATPase was observed in this fraction, which exhibited a weak activity of UDP-galactose: N-acetylglucosamine galactosyltransferase, a marker enzyme for Golgi body. Cl-,HCO3(-)-ATPase in the skeletal vacuole membrane probably mediates HCO3- transport into the vacuoles to supply HCO3- for spicule formation.

5'-Nucleotidase↗

Free fatty acids in gallstones in mice fed a diet containing cholic acid.

In mice, combined addition of 1% cholesterol and 0.5% cholic acid to a diet induced cholesterol gallstones within 40 days as a result of the supersaturation of cholesterol in the bile, as has been reported. The major component of the gallstone was cholesterol, which was measured by HPLC. In this study, however, single addition of 1% cholic acid to a diet, which did not decrease cholesterol solubilizing capacity in bile, contributed to gallstone formation in mice within 50 days. The gallstones thus formed contained a large amount of palmitic acid. In the hepatic bile of this animal, palmitic acid was also detected; however, no solid material was observed by light and polarized-light microscopes. Free fatty acids such as palmitic acid seem to be dissolved in a complex micelle composed of bile acids and lecithin. This probably causes gallstone formation by reducing cholesterol solubilizing capacity in bile.

Animals↗

In vitro effects of prostaglandins on human retinoblastoma cell line, Y-79 cells.

Prostaglandins (PGs) and their derivatives have been reported to modulate or inhibit a variety of tumor cells in vitro and in vivo. In the present study, an established retinoblastoma cell line, Y-79, was investigated for 1) its capacity to synthesize PGs and 2) its susceptibility to PGs and their derivative, 64E, exogenously given. The capacity of Y-79 cells to produce PGs was estimated by thin layer chromatography using [1-14C] arachidonic acid as a substrate, and it was found that no detectable amounts of PGD2, PGE2, PGF2 alpha, thromboxane B2, or 6-keto PGF1 alpha were produced by Y-79 cells. Furthermore, the effects of exogenously given PGs (PGA1, A2, D2, E1, E2, F2 alpha, and J2) and 64E on the cell proliferation of Y-79 cells in culture were examined. PGE1, E2, and F2 alpha showed no significant effects on the cell growth of Y-79 cells at all tested doses (1-20 micrograms/ml). On the other hand, PGA1, A2, D2, and J2, and 64E remarkably inhibited the cell growth of Y-79 cells. A dose-response study indicated that 64E was the most effective among these drugs, followed by PGJ2. PGD2, A1, and A2 were less effective than PGJ2. The present data demonstrate that Y-79 cells do not produce endogenous PGs, and that these cells are highly susceptible to exogenous PGs (PGJ2, D2, A1, and A2) as well as 64E.

Cell Division↗

Actin in wound-healing of rabbit corneal endothelium. I. Study by immunoperoxidase method.

The distribution of actin in the rabbit cornea was examined by the indirect immunoperoxidase method using mouse monoclonal anti-actin IgM and goat anti-mouse IgM serum conjugated with peroxidase, which was stained with 4-chloronaphthol. Flat preparation of the cornea was made and the actin distribution was examined in the normal endothelium and also during wound-healing of the endothelium that took place after transcorneal freezing. In the normal cornea, the epithelial, stromal and endothelial cells contained actin in the cytoplasm. Diffuse actin staining in the endothelial cytoplasm was observed in the flat preparation of the normal endothelium. After endothelial damage, the cells adjacent to the damaged area showed a fiber-like staining of actin around the nucleus; this occurred 12 to 24 hours after the freezing. Punctate staining was seen on the 2nd day, and the intensity of the staining was maximum on the 3rd day when the wound was completely covered. On the 3rd day, fibroblast-like cells were encountered and a long fiber-like staining of actin was seen in the cytoplasm, but the staining disappeared on the 4th day. The long fiber-like and punctate staining reappeared on the 14th day. Normal staining pattern was recovered on the 28th day. These findings suggest that actin production was accelerated in the endothelial cells during the wound-healing, and that this productive activity returned to normal levels as healing was completed.

Actins↗

Actin in wound-healing of rabbit corneal endothelium. II. Study by nitrobenzoxadiazole-phallacidin method.

The distribution of F-actin in the rabbit corneal endothelial cells was studied in vivo and in culture using nitrobenzoxadiazole-conjugated phallacidin. In the normal cornea, the fluorescence showing the presence of F-actin was observed along the membrane of the endothelial cells, but little fluorescence was seen in the cytoplasm. During wound-healing processes after transcorneal freezing, the endothelial cells migrating to the wound area showed abundant fiber-like fluorescence in the cytoplasm. In about 28 days after the injury, the endothelial cells recovered normal shape and the pattern of actin localization became normal, ie, fiber-like fluorescence localization along the cell membrane. The endothelial cells were cultured for about one week and the explants were removed. After further culture for about two weeks the cultured cells became confluent forming a monolayer. At the center of this monolayer, a small wound was made, and changes in the cell shape and actin distribution were studied. The actin distribution in the undisturbed monolayer cells was similar to that seen in vivo, ie, fiber-like fluorescence along the cell membrane. After the wound production, many cells were seen to migrate toward the wound center, and abundant fluorescent fiber-like structures were observed throughout the cytoplasm. Addition of cytochalasin B to the culture medium suppressed cell migration in a dose-dependent manner. At a high cytochalasin B concentration the fiber-like fluorescence was not formed and scattered fluorescent speckles were observed. Further culture in cytochalasin B-free medium after exposure to this agent permitted a recovery of cell migration and formation of the fiber-like actin fluorescence. It was suggested that polymerization of actin filaments is activated in the migrating cells during wound-healing, and that cytochalasin B reversibly blocks this polymerization, thereby suppressing cell migration. Actin filament polymerization would constitute a significant part of the mechanism underlying cell migration and wound-healing.

Actins↗

In vivo effects of prostaglandins on human retinoblastoma cells in nude mice.

Prostaglandin D2 (PGD2) and 64E, a derivative of PGs, were tested for their capacity to suppress the growth of retinoblastoma in the nude mouse. Ten million cells of an established cell line of human retinoblastoma, Y-79 cells, were transferred subcutaneously into the nude mouse, and after the transferred cells became a tumor with a diameter larger than 7.5 mm, either PGD2 (1, 2, or 4 mg/kg/day) or 64E (4 mg/kg/day) dissolved in Hanks' solution was daily injected subcutaneously near the tumor for 14 days. The estimated tumor weight as defined by the formula of (length) X (width)2/2 was evaluated at various time intervals after the treatment. Although a low dose of PGD2, 1 mg/kg/day, had no effect, higher doses of PGD2 had a clear effect in suppressing the growth of retinoblastoma in the nude mouse. Tumors in 64E-treated animals were also markedly suppressed in their growth. Histological examination revealed that tumors treated with these drugs had a much larger area of necrosis with fewer tumor cells than the tumors in control animals.

Animals↗

Stimulatory effect of certain plant sphingolipids on fruiting of Schizophyllum commune.

We reported previously that certain cerebrosides and ceramides from fungi were active upon fruiting of Schizophyllum commune (Kawai, G., and Ikeda, Y. (1982) Biochim. Biophys. Acta 719, 612-618; Kawai, G., and Ikeda, Y. (1983) (Biochim. Biophys. Acta 754, 243-248). This work was undertaken to extend our study to sphingolipids in wheat grain. The cerebrosides from wheat grain were fractionated by high-performance liquid chromatography into at least 40 components with and without the fruiting-inducing activity. Four major active fractions were characterized by thin-layer chromatography, infrared spectroscopy, gas-liquid chromatography, gas-liquid chromatography-mass spectroscopy, and 1H and 13C nuclear magnetic resonance spectroscopy. The active cerebrosides consist of glucose, 2-hydroxyhexadecanoic acid or 2-hydroxyoctadecanoic acid acid, and (4E,8Z)-sphingadienine or (8Z)-sphingenine. The cerebroside with (8Z)-sphingenine became inactive when the double bond was hydrogenated. Diglycosylceramides were as active as the monoglycosylceramides, but triglycosylceramides were only about 10% as active. The relationship between the structure and the activity is discussed.

Basidiomycota↗

Radiographic microstructures of early esophageal carcinoma: correlation of specimen radiography with pathologic findings and clinical radiography.

To clarify the exact radiologic features of mucosal carcinoma of the esophagus with a favorable prognosis, contact radiography was performed on 8 surgical specimens diagnosed preoperatively as showing early or superficial carcinoma. Mucosal carcinoma appeared as a well-defined smooth or nodular protrusion or as a feathered flat mucosa with tiny nodulations and barium poolings. Submucosal carcinoma showed a mound-like defect. The size of tumor was not a good index for estimating the depth of invasion. Protruded lesions were easily demonstrated on clinical radiographs and their profile was useful in determining the depth of invasion. Flat lesions were not easy to recognize; attention must therefore be paid not only to mucosal patterns but also to the contour of the esophageal wall.

Aged↗