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Biomedical subjects

M Sumiya

Publications and source records attributed to M Sumiya.

At least 73 records · Page 4Linked to original sources
PubMed1987

Iodine-131 and other radionuclides in environmental samples collected from Ibaraki/Japan after the Chernobyl accident.

Measurements were made of 131I, 137Cs, 134Cs and 103Ru in environmental samples collected from Ibaraki-Prefecture, Japan, after the Chernobyl accident. The highest values of 131I obtained in May 1986 were 98 Bq l-1 (2.7 nCi l-1) for rain water (collected at the beginning of the rainfall), 400 Bq kg-1 (11 nCi kg-1) for pine needles (wet), 160 Bq kg-1 (4.3 nCi kg-1) for vegetables (wet) and 52 Bq kg-1 (1.4 nCi kg-1) for seaweed (wet). Most of the radioiodine in rain water was present as IO3- and I-. The proportion of IO3- in fresh rain water was higher than that of I-, but the IO3- was converted to I- during storage. About 10% of 131I was removed from leaf vegetables by washing, and about 70% by boiling.

Accidents↗
PubMed1983

Protein-losing enteropathy in systemic lupus erythematosus.

Although protein-losing enteropathy can be associated with a variety of disorders, only three cases have been described in association with systemic lupus erythematosus. In the case described herein, protein-losing enteropathy was the only clinical manifestation of systemic lupus erythematosus. Small intestinal biopsy revealed edema and mild mononuclear cell infiltration in lamina propria mucosae and no evidence of lymphangiectasia. X-ray studies of the gastrointestinal tract were normal. Protein-losing enteropathy responded to high-dose corticosteroid therapy. Protein-losing enteropathy should be suspected as a possible cause of unexplained hypoalbuminemia in systemic lupus erythematosus.

Adult↗
PubMed1982

Natural killer cell activity in untreated systemic lupus erythematosus.

With strictly selected controls natural killer cell activity was evaluated in 10 untreated patients with systemic lupus erythematosus. Natural killer levels of the patients were significantly lower than those of the age- and sex-matched normal controls. Natural killer levels, however, did not correlate with disease activity.

Adolescent↗
PubMed1982

Induction of cytotoxic lymphocytes by protein A derived from Staphylococcus aureus. I. Protein-A-induced, protein-A-dependent cytotoxicity of T lymphocytes against human lymphoblastoid cell lines.

Protein A (pA) from Staphylococcus aureus is known to be a good mitogen for human T lymphocytes. In this study, the cytotoxic activity of pA-activated lymphocytes was assessed using human lymphoblastoid cell lines (LCL) as target cells. pA induced higher cytotoxic activity against LCL on the 3rd day of incubation than phytohemagglutinin or concanavalin A. However, it was necessary for pA to be present in the assay for these pA-activated lymphocytes to manifest their cytotoxicity. Cytotoxic activity was not detected in a control culture in which pA was added at the assay, nor was it detected in the supernate of pA-activated culture. These data suggest that the cytotoxicity of these lymphocytes was pA-activated, pA-dependent cell-mediated cytotoxicity, pA-activated, pA-dependent cytotoxicity was mediated by T lymphocytes and was induced from Fc-receptor-negative [Fc(-)] T lymphocytes. The effector cells were mainly Fc(-) T lymphocytes. The relationship between pA-activated, pA-dependent cytotoxicity, lectin-dependent cellular cytotoxicity and alloantigen-induced cytotoxic T lymphocytes is also discussed.

Cell Line↗
PubMed1982

Medullasin enhances human natural killer cell activity.

Medullasin, a new serine protease found in bone marrow cells, increased markedly human natural killer cell activity. Whereas the natural killer cell activity measured immediately after the treatment with medullasin remained almost on the same level as the control, an incubation at 37 degrees C for several hours increased markedly the natural killer cell activity of the lymphocytes treated with medullasin. Enhancement of the natural cytotoxicity was caused by the treatment with physiologic concentrations of the protease (5-20 micrograms/ml). Inhibitors of medullasin such as phenylmethylsulfonyl fluoride and elastatinal prevented the activation of natural cytotoxicity. Depletion of lymphocytes bearing Fc receptors for IgG abolished the enhancement of natural killer cell activity by medullasin. Interferon activity was not detected in the supernatant of lymphocyte cultures stimulated with medullasin. The medullasin enhanced further the natural killer cell activity of lymphocytes stimulated with interferon. Medullasin activity was detected neither in unstimulated nor stimulated (by concanavalin A or phytohemagglutinin) human lymphocytes. The protease was released easily from human mature granulocytes into culture medium. It is considered from these results that the level of human natural killer cell activity is regulated by medullasin released by mature granulocytes.

Cytotoxicity, Immunologic↗
PubMed1981

Cytotoxicity of cultured mouse spleen cells against natural killer-sensitive target cells. Characterization of the effector cells.

Killer cells with natural killer (NK) cell-like target selectivity were generated when C3H or C57BL/6 mouse spleen cells were cultured in vitro. Compared with NK cells, the in vitro-generated killer cells with NK-like reactivity were slightly adherent to nylon wool fibers, a little more sensitive to anti-Thyl.2 antibody plus complement and almost entirely resistant to cytotoxic treatment with anti-asialo GM1 antiserum which is selectively cytotoxic to NK cells. The culture of NK-depleted spleen cells yielded a lower degree of NK-like cytotoxicity, thus it seems likely that NK cells changed to NK-like killer cells in vitro. Competitive inhibition studies suggested that the in vitro-generated NK-like cells were different from alloantigen-reactive killer T cells. The above results, therefore, might suggest that in vitro-induced NK-like cells do not belong to any known subset of killer cells.

Animals↗
PubMed1980

Stimulation of human lymphocyte subpopulations by protein A from Staphylococcus aureus.

Protein A from Staphylococcus aureus is known to stimulate human lymphocytes. Using 3H-thymidine incorporation, virus plaque assay and induction of cytotoxic T lymphocytes (CTL), this study showed that soluble or insoluble protein A stimulated different lymphocyte subpopulations. Soluble protein A is highly mitogenic to T lymphocytes. In both 3H-thymidine incorporation and virus plaque assay, its maximum stimulation was as high as the stimulation by the nonspecific mitogens phytohemagglutinin and concanavalin A, and a higher CTL response than that induced by phytohemagglutinin or concanavalin A was induced. Mitogenic activity to B lymphocytes was negligible. S. aureus (Cowan I strain) is itself considered to be an insoluble form of protein A and is 3--4 times more mitogenic to B lymphocytes than pokeweed mitogen without any increase in virus plaque-forming cells. No mitogenicity was noted to T lymphocytes. Sepharose CL-4B-protein A, also known as insoluble protein A, stimulated both T and B lymphocytes effectively, but its mitogenicity to T lymphocytes was considered to be due to the soluble protein A released from the Sepharose CL-4B beads.

B-Lymphocytes↗
PubMed1980

Activation of secondary cytotoxic lymphocytes by cell-free factors from I-region-primed and D-region-primed lymphocytes.

Cell co-operation in the generation of secondary cytotoxic responses was studied by selectively sensitizing lymphocytes in mixed lymphocyte culture (MLC) across I or D region difference and by combining the primed lymphocytes in the secondary MLC. Secondary cytotoxic responses were induced in D-region-primed lymphocytes by restimulation with the original priming D-region antigens, by co-culturing with the I-region-primed lymphocytes in the presence of the priming I-region antigens, or by cell-free supernatants obtained 24 h after the restimulation of D-region-primed lymphocytes and I-region-primed lymphocytes, The active MLC supernatants produced by both I-region-primed and D-region-primed cells also induced accelerated proliferative responses in D-region-primed lymphocytes. Heat-treatment or ultraviolet irradiation of the stimulator cells eliminated the capacity of the cells to induce the production of CTL-helper factor in I-region-primed and D-region-primed lymphocytes. It was concluded that both I-region-primed and D-region-primed lymphocytes produce a cell-free factor which induces proliferation and secondary cytotoxicity in D-region-primed lymphocytes. The possible participation of D-region reactive helper T cells and D-region reactive cytotoxic T cells in the cytotoxic responses to D-region antigens in the absence of I-region difference is discussed.

Animals↗
PubMed1980

Generation of autoreactive cytotoxic lymphocytes by spontaneously established autologous lymphoblastoid cell line.

Using spontaneously established autologous and allogeneic LCL as stimulator and target cells, we studied the generation of autoreactive cytotoxic T lymphocytes (CTL) in primary and secondary autologous MLC. In the primary autologous MLC, cytotoxic activity was detected on the 6th day and was found to be specific to autologous LCL. In the secondary autologous MLC, cytotoxic activity was detected earlier on the 3rd day, and was at a higher level than in the case of the primary autologous MLC. This cytotoxic activity was induced in both the primary and the secondary autologous MLC when T lymphocytes were used as responder cells. When autologous LCL-primed lymphocytes were used as responder cells in the secondary MLC, autologous LCL-specific CTL were not only generated by autologous LCL but also by allogeneic LCL, and the autologous LCL-specific CTL induced by allogeneic LCL was thought to be due to the nonspecific helper effect of allogeneic LCL-stimulation.

Animals↗
PubMed1980

Effects of corticosteroids on natural killer cell activity in systemic lupus erythematosus.

The effects of corticosteroids on the natural killer (NK) cell activity of human peripheral blood lymphocytes were evaluated. When six untreated female patients with systemic lupus erythematosus were compared with fifteen age-matched, corticosteroid-treated female patients, NK activity in the latter was significantly suppressed. Although the administration of high doses seemed to suppress cytotoxicity to a greater extent, there was no close correlation between the daily doses of steroids and NK activity. When cytotoxicity levels were followed before and during corticosteroid therapy in the same patient, NK activity decreased markedly during treatment, particularly in patients on high-dose corticosteroids.

Adult↗