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Biomedical subjects

K Shima

Publications and source records attributed to K Shima.

At least 559 records · Page 31Linked to original sources
PubMed1972

Macrophage accumulation, division, maturation, and digestive and microbicidal capacities in tuberculous lesions. I. Studies involving their incorporation of tritiated thymidine and their content of lysosomal enzymes and bacilli.

Dermal and pulmonary tuberculous lesions were produced in rabbits with BCG, biopsied, incubated in vitro with tritiated thymidine ((3)HT) under hyperbaric oxygen, quickly frozen, sectioned in a cryostat, stained for the lysosomal enzyme beta-galactosidase, autoradiographed, stained for acid-fast bacilli and counterstained with hematoxylin. As macrophages developed into epithelioid cells, they could still divide-ie, incorporate (3)HT. However, once they became fully mature epithelioid cells that were 4-plus in beta-galactosidase, they could not do so. Tuberclebacilli did not stimulate macrophage division. On the contrary, macrophages containing bacilli did not divide, except when the lesions began. During the development of tuberculous lesions, macrophages (including those rich in enzymes and those containing bacilli) died, forming caseous centers. Therefore, local cell division did not seem to be the main mechanism by which macrophages reduced their bacillary load. Such division seemed mainly to occur in young macrophages that had recently immigrated into the lesions from the bloodstream and had not yet ingested bacilli.

Animals↗
PubMed1971

Radiation, Infection, and Macrophage Function IV. Effect of Radiation on the Proliferative Abilities of Mononuclear Phagocytes in Tuberculous Lesions of Rabbits.

Rabbits were irradiated with 400 to 600 rads 2 to 3 days before they were infected with BCG or with virulent tubercle bacilli. Biopsies were periodically removed from the resulting lesions and incubated for 1 hr with (3)H-thymidine in vitro under hyperbaric oxygen. Twelve to 16 days after radiation there was a reduction in the percentage of mononuclear cells (macrophages and some lymphocytes) that had incorporated (3)H-thymidine in the lesions. At this time, the lesions of the irradiated group were smaller than those of controls. These results can be explained by the reduction in the number of new mononuclear cells that entered the lesions of the irradiated group and support the tenet that local mononuclear cell division occurs mainly in cells that have recently emigrated from the blood stream. An alternate, but less likely, explanation of these results would be that radiation caused the bone marrow to release a higher percentage of "defective" mononuclear cells that were unable to divide, i.e., incorporate (3)H-thymidine, in the lesions. The reduction produced by radiation in both local cell infiltration and local cell division would decrease the number of macrophages available to control the tuberculous infection in the host.

Journal Article↗
PubMed1971

[Glucagon].

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Adenylyl Cyclases↗
PubMed1971

[Glucagonoma].

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Adult↗