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Biomedical subjects

Y Ohashi

Publications and source records attributed to Y Ohashi.

At least 703 records · Page 39Linked to original sources
PubMed1982

Effect of experimental herpes simplex virus vaccine on established ganglionic latency.

Mice were inoculated with herpes simplex virus type 1 by the corneal route beforehand. Ten weeks after the inoculation, one group of mice was repeatedly treated with infectious virus-free, detergent-soluble extract of virus-infected cells (DSE) by the intraperitoneal route and the other group served as the controls. The virus recovery rate from the trigeminal ganglia of DES-treated mice was markedly reduced as compared with that of untreated mice, when a small amount of inocula was used. However, no significant decrease in the virus recovery rate was obtained when a large amount of inocula was used, suggesting that treatment with DSE had a limited effect on established ganglionic latency. The level of neutralizing antibody titers in the serum did not seem to be correlated with the efficacy of DSE in mice infected with a small amount of inocula.

Animals↗
PubMed1982

Fibronectin in corneal wound healing: appearance in cultured rabbit cornea.

Fibronectin (FN) has been detected at the site of corneal wounds. To investigate whether FN is supplied by the cornea itself or by extracorneal sources, we cultured small blocks of rabbit cornea in vitro with and without autologous serum (5%). The sliding rate of epithelial cells was determined and localization of FN in the corneal block examined by indirect immunofluorescent microscopy. Epithelial cells slid more rapidly in the presence of serum and covered most of the stromal surface in about 24 hours. FN was detected at the surface edge of the cut stroma shortly after culturing began. During epithelial cell sliding, FN-specific fluorescence was noted beneath the migrating cells. The location of FN was essentially the same in cultures with and without autologous serum. These results suggest that FN might be supplied by the cornea itself and that it may play a role in epithelial cell sliding.

Animals↗
PubMed1981

[Studies on industrial styrene poisoning (part XII). Electron-microscopic observations on the mucosal membrane of respiratory tracts of rats exposed to styrene. (author's transl)].

The influences which are known to be caused by styrene on the human body are stimulation of the mucosal membrane and atrophy of the central nervous system. There are several clinical reports and animal experiments concerning the stimulation of the mucosal membrane, and styrene is presumed to stimulate the mucosal membrane of the nose. To the best of our knowledge, however, there have been no reports describing histological pathology of the mucosal membrane of the nose induced by exposure to styrene. Accordingly we made animal experiments using rats in order to see influences of styrene on the mucosal membrane of the upper and lower respiratory tracts including the mucosal membrane of the nose, and could confirm the following changes electron-microscopically: 1. Increases in the amount of mucous adhering to cilia, 2. Occasional formation of compound cilia, 3. Appearance of substances having a higher electron-microscopic density within the cytoplasm of various epithelial cells, 4. Degeneration of secretory granules of goblet cells--changes in electron-microscopic density, appearance of cores with a higher electron-microscopic density, 5. Nuclear pyknosis, 6. Vacuolization of various epithelial cells, and 7. Separation and falling-off of the epithelial cell layer.

Animals↗
PubMed1981

Prevention of syngeneic tumor growth in vaccinia virus-primed mice by immunization with vaccinia virus-modulated tumor cells.

Immunization with vaccinia virus-infected and then X-ray-irradiated murine hepatoma MH134 cells provided C3H/He mice with strong resistance to challenge with viable MH134 cells. Male C3H/He mice of 5 to 6 weeks old were primed intraperitoneally (IP) with 1 x 10(7) PFU of live vaccinia virus (Ikeda strain) after irradiation with 250 R of X-ray. Three weeks after priming, the mice were immunized IP 3 times at weekly intervals with 1 x 10(7) X-ray-irradiated MH134 cells that had been infected with vaccinia virus 8 h before irradiation. Over 60% of these cells showed vaccinia virus-induced antigen on their surface (membrane antigen). Challenge with viable MH134 cells was done by inoculating 1 x 10(5) cells IP one week after immunization. During a 4-week observation period, all the untreated control mice died with ascites. On the contrary, all the mice that were X-ray-irradiated, primed and immunized survived challenge with the tumor cells for at least 4 weeks. The mortalities of mice in other groups that were not irradiated, or not primed, or immunized with only X-ray-irradiated tumor cells, were at lowest 50%.

Animals↗
PubMed1980

Mutagenicity of nifurtimox in Escherichia coli.

The effects of nifurtimox, a nitrofuran derivative, on killing and mutation induction in 3 Escherichia coli strains having different DNA-repair systems for UV lesion were studied and compared with the effects of furylfuramide. Nifurtimox induces mutations at a high frequency in both Hs3OR (uvrA-) and H/r30R (radiation-resistant), although no significant killing effect is detected with Hs30R. No significantly induced mutation frequency could be detected with NG30 (recA-), which is very sensitive to killing by nifurtimox. The characteristics of lesions of DNA induced by nifurtimox and the mechanism of mutation induction in Hs30R are discussed.

DNA Repair↗
PubMed1980

In vitro and in vivo antibacterial activity of KW1070, a new aminoglycoside antibiotic.

KW1070, a new aminoglycoside antibiotic with the novel aminocyclitol, fortamine, has a broad spectrum of activity in vitro and in vivo against gram-positive and gram-negative bacteria. The minimum inhibitory concentrations of KW1070 are similar to those of kanamycin against aminoglycoside-susceptible strains, slightly less than those of gentamicin or 3',4'-dideoxykanamycin B. Minimal bactericidal concentrations were found to be near minimal inhibitory concentrations. KW1070 was active in vitro against many aminoglycoside-resistant bacterial strains that possess aminoglycoside-inactivating enzymes, particularly AAC(6'), AAC(2'), AAD(2''), and APH(3'). The activities of KW1070 in mice infected with Staphylococcus aureus, Escherichia coli, Proteus sp., and Serratia marcescens compared favorably with the activities of amikacin and kanamycin; KW1070 was also singificantly active in mice infected with resistant strains bearing the aminoglycoside-inactivating enzymes listed above.

Acetylation↗
PubMed1980

A detergent-soluble extract of virus-infected cells free from infectious virus protects mice from lethal herpes simplex virus infection.

Lethal infection with herpes simplex virus types 1 (HSV-1) and 2 was effectively prevented by previous immunization with a detergent-soluble extract (DSE) of virus-infected cells free from infectious virus without any adjuvant. This protective immunity seemed to last for at least one month. Neutralizing antibodies were elicited in mice immunized with DSE, but at a lower level than in animals immunized with live or killed virus. DSE did not protect athymic nude mice from death by HSV-1 infection, suggesting that a T cell-mediated immune response plays a major role in the protection.

Animals↗
PubMed1979

Disassembly of tobacco mosaic virus by membrane lipid isolated from tobacco leaves and polyornithine.

In vitro disassembly of tobacco mosaic virus (TMV) virions occurred in the presence of both polyornithine and a lipid fraction isolated from tobacco leaf membrane. The latter could be replaced by lecithine. Disassembly of 10 microgram of TMV virions was attained in the presence of a 500-mg leaf equivalent of membrane lipid and 20 microgram of polyornithine in 1 ml of 0.01 M Tris-HCl buffer, pH 7.4 at 30 C. Similarity and dissimilarity between the in vitro disassembly and the in vivo uncoating mechanisms are discussed.

Membrane Lipids↗