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Biomedical subjects

T Mikami

Publications and source records attributed to T Mikami.

At least 577 records · Page 32Linked to original sources

Suppression of NK activity of spleen cells by chicken fetal antigen present on Marek's disease lymphoblastoid cell line cells.

Chicken fetal antigen (CFA) expressed on the cell surface of Marek's disease (MD) lymphoblastoid cell line (MDCC-MSBI) cells was purified by affinity chromatography using a monoclonal antibody (2H3). A 4-hr 51Cr release assay was performed using spleen cells as effector cells to investigate the role of the CFA in the immune response of chickens, especially in relation to natural killer (NK) activity. Spleen cells of specific-pathogen-free (SPF) chickens showed reduced NK activity in the presence of CFA in vitro, as did those cells treated with MSBI soluble antigen. NK activity of spleen cells from chickens treated with CFA was also suppressed when compared to the cells from untreated or ovalbumin-treated chickens. In addition, MSBI clo. 18 transplantable tumors grew progressively in some of the 14-day-old chickens treated with CFA, whereas the tumors regressed in age-matched chickens with or without treatment by ovalbumin.

Animals↗

Pathogenicity and immunogenicity in chickens of Newcastle disease viruses isolated from wild ducks. Brief report.

Three Newcastle disease viruses (NDV) isolated from wild ducks in Japan were evaluated for their biological activities, pathogenicity and immunogenicity against one-day-old chickens. One isolate was of the mesogenic type and the other two were of the lentogenic type for chicken. The lentogenic isolates could induce enough immunity in chickens to protect them from challenge with a virulent strain of NDV.

Animals↗

Cellular and humoral immune responses in experimental aspergillosis in mice.

Invasive aspergillosis was established in a naive murine model. Both humoral and cellular aspects of the immunological mechanism responded to invasion. Circulating immune complexes containing IgG in the infected group of animals were detected by both the C1q and conglutinin solid phase assays. Attempts to identify these complexes as Aspergillus antigen-specific complexes were unsuccessful. Cellular responses, as measured by blastogenic activity and inhibition of migration of sensitized cells were significantly elevated in the infected group.

Animals↗

Antigenic variation of Newcastle disease viruses isolated from wild ducks in Japan.

Nineteen strains of Newcastle disease virus (NDV) isolated from wild ducks in Japan were placed into 4 distinct antigenic groups on the basis of their reactivities to 8 monoclonal antibodies against the HN molecule of NDV in hemagglutination inhibition tests. The NDV strains of duck origin were antigenically distinct from NDV-B1 and NDV-Miyadera originated from chickens, and varied in their virulence to chicken embryos. No apparent correlation was found between the antigenicity of the HN molecule and virulence.

Animals↗

Quantitative measurement of endotoxin in rainbow trout (Salmo gairdneri) serum by the chromogenic substrate method.

The amount of endotoxin in serum collected from normal rainbow trout (Salmo gairdneri) and trout inoculated with viable Vibrio anguillarum or lipopolysaccharide (LPS) extracted from bacteria was determined by the chromogenic substrate method. The mean values of endotoxin in four different groups of normal rainbow trout sera ranged from 31.9 to 65.3 pg/ml. When fish were inoculated with viable bacteria (1 x 10(8], they became septicaemic and a large amount of endotoxin ng/ml) was detected in the sera. In fish inoculated with a smaller number of bacteria the amount of endotoxin was several times higher than that of normal fish in spite of failure of bacterial isolation. Although the endotoxin level in serum increased rapidly (greater than 100 ng/ml) after intraperitoneal inoculation with purified V. anguillarum LPS (540 micrograms), no fish died during the experiment. The high level of endotoxin in normal rainbow trout and the resistance of trout to endotoxin are in striking contrast to those of mammalian and avian species.

Animals↗

Effect of left ventricular assist device (LVAD) on myocardial pH change after regional coronary occlusion.

To evaluate the effect of an assist pump on the metabolic viability of the ischemic myocardium, myocardial pH was continuously monitored using an ion-sensitive field-effect transistor (ISFET) pH sensor in 14 dogs after coronary occlusion. In seven dogs (control group), coronary occlusion (10-20 min) and successive reperfusion (30-60 min) were performed several times. In seven dogs [left ventricular assist device (LVAD) group], the LVAD was implanted between the left atrium and the aorta. Occlusion and reperfusion were performed first with the pump on and then with the pump off. In both groups, myocardial pH fell after occlusion, and increased after reperfusion. In the control group, the fall rate of pH in the later coronary occlusion decreased to 66 +/- 7% (mean +/- SEM) of that in the previous occlusion. Contrarily, in the LVAD group, the fall rate under LVAD-off increased to 174 +/- 32% of that under the preceding LVAD-on. This indicates that progressive cellular damage occurred in the control group, while the myocardium was preserved by the assist pump in the LVAD group. LVAD is effective for preserving the metabolic viability of the ischemic myocardium.

Animals↗

Participation of peptide moieties in adhesive behavior of antigenic mannans of Candida albicans to the plastic microtiter plate in enzyme-linked immunosorbent assay.

We report our studies of the mechanism of the adhesion of mannans of Candida albicans NIH A-207 and C. albicans NIH B-792 strains to the surface of a polystyrene microtiter plate being utilized for enzyme-linked immunosorbent assay (EIA) of antigens of this pathogenic yeast species. This binding was manifested predominantly by the peptide moieties of the mannans forming hydrophobic bonds with the plastic molecule. Eliminating the peptide of each mannan by treating it with a hot aqueous alkaline solution of NaBH4 also eliminated color development in the EIA.

Adhesiveness↗

Effect of the intermittent prophylactic treatment of the central nervous system in adults with acute leukemia.

Nineteen patients with acute leukemia, who achieved complete remission between January, 1980 and March, 1983, were given 10 mg of methotrexate (MTX) and 20 mg of prednisolone (PSL) intrathecally at 1st, 3rd, 6th, 10th and 15th month after the termination of consolidation therapy followed by the same dose twice a year, when the intensification therapy was being performed. During the observation period of 29 to 68 months, none developed central nervous system (CNS) leukemia. On the other hand, the incidence of CNS leukemia in patients given the prophylactic intrathecal treatment once or twice just after the complete remission was 35% (7/20) compared with 24% (8/33) in patients without treatment. No statistical difference was observed in these groups. The intrathecal administration of MTX and PSL is easy to perform and no adverse reaction was observed in our series. It is concluded that the intermittent prophylaxis with MTX and PSL is of benefit in preventing CNS leukemia in adults patients with acute leukemia.

Acute Disease↗