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Biomedical subjects

M Ashida

Publications and source records attributed to M Ashida.

10 recordsLinked to original sources

Immunocytochemical localization of beta-1,3-glucan recognition protein in the silkworm, Bombyx mori.

A monospecific antibody against beta-1,3-glucan recognition protein (a 62 kDa protein) of the larval silkworm prophenoloxidase activating system was used to study the localization of the protein. Among tissues from 5th instar larvae, only hemocytes and plasma were shown to contain a 62 kDa polypeptide immunoreactive with the antibody. Ultra-thin sections of the hemocytes were stained by an indirect immunogold staining method. Labelling occurred in the granules and cytoplasm of granulocytes and in the spherules and cytoplasm of spherulocytes. It was most conspicuous in granules of granulocytes and uniformly labelled spherules of spherulocyte, whereas no labelling was evident in prohemocytes, plasmatocytes and oenocytoids. The results are discussed in relation to the mode of recognition of fungi as non-self in insect hemocoel.

Animals

Use of nitrocellulose membrane to activate and measure insect prophenol oxidase.

A method for the activation and measurement of insect prophenol oxidase using nitrocellulose membrane is presented. Using this method we were able to conveniently activate both crude and purified prophenol oxidase from insects belonging to three different orders. This rapid method allows for prophenol oxidase activation, in the absence of a prophenol oxidase-activating system, and in the presence of high ionic strength, protease inhibitors, or chelator.

Aedes

Studies on prophenoloxidase activation in the mosquito Aedes aegypti L.

This study, the first of its kind in a mosquito vector species, demonstrates the feasibility of studying prophenoloxidase activation in an insect containing not more than a few microliters of hemolymph. Mosquito phenoloxidase was found to be in an inactive proenzyme form, prophenoloxidase. Mosquito prophenoloxidase required bivalent cation for its activation; Ca2+ was found to be the most efficient for activation. Concomitant amidase activity was also observed prior to phenoloxidase activity. Through Western blotting, using a cross-reactive silkworm antiprophenoloxidase antibody, our results strongly suggest that mosquito prophenoloxidase activation resulted from limited proteolysis. Protease inhibitor studies reinforced this contention showing the involvement of (a) serine protease(s) with trypsin-like activity in the activation of mosquito prophenoloxidase.

Aedes

Propagation of hepatitis A virus in hybrid cell lines derived from marmoset liver and Vero cells.

To establish monkey liver cell lines with a high susceptibility to hepatitis A virus (HAV), marmoset (Saguinus labiatus) liver cells were fused with Vero cells deficient in hypoxanthine-guanine phosphoribosyltransferase and the resulting hybrid cells were selected in HAT medium. Of four hybrid cell lines obtained (S. 1a/Ve-1 to -4), three (S. 1a/Ve-1, -3 and -4) were equally susceptible to HAV infection. When inoculated with a virus isolated from marmoset liver tissue (10% liver tissue extract) or a faecal virus (10% stool extract) from a human hepatitis A patient, all susceptible cell lines showed a significant elevation of viral antigen activity as seen in radioimmunoassay and/or immunofluorescent antibody assays, at 4 to 6 weeks post-infection (p.i.) with the liver-derived inoculum and at 6 to 8 weeks p.i. with the stool-derived inoculum. In S. 1a/Ve-1 cells, a representative of the susceptible hybrid cell lines, full adaptation of HAV (liver tissue virus concentrate) to cell culture was attained after four serial passages. Thereafter, the virus grew to a plateau titre of 10(8.5) TCID50/ml at 7 days p.i. in a growth experiment. The infected cells showed no cytopathic effects but eventually a persistent infection was established when a saturated level of virus growth was reached.

Animals

[A case of acute retinal necrosis syndrome caused by herpes simplex virus type 1].

A case of bilateral acute retinal necrosis syndrome accompanied by viral meningitis in a 46 year-old male is reported. The characteristic scattered yellowish-white retinal exudates and retinal detachment appeared in both eyes within 2 weeks, and after treatment with intravenous acyclovir and gamma-globulin, and encircling, scleral buckling, pars plana vitrectomy, 100% SF6 tamponade procedures, the retinal detachment was repaired and the yellowish-white retinal exudates disappeared. On virological examination, the complement fixation titer for herpes simplex virus (HSV) in serum increased more than eightfold in pair serum, and the quotient of antibody for HSV type 1 (HSV-1) IgG was high. HSV-1 was isolated and cultured from the subretinal fluid. From these results, it is concluded that HSV-1 infection was the cause of the meningitis and acute retinal necrosis in this case.

Acute Disease

Temperature dependent ionic structure of phospholipid monolayers.

Radiotracer studies of calcium adsorption to dipalmitoylphosphatidyl-alkanolamine monolayers measured at various temperatures showed that the binding constant of calcium increased with temperature up to around 30 degrees C but the decreased on exceeding this critical temperature. The temperature dependent ionic structure of ampholytic phospholipid monolayers are discussed.

Calcium