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Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 667 records · Page 37Linked to original sources
PubMed1982

Demonstration of in vivo DNA repair synthesis in mouse skin exposed to various chemical carcinogens.

Chemical carcinogen-induced unscheduled DNA synthesis in mouse skin in vivo was demonstrated with the aid of a mechanical device. An isotonic aqueous solution containing a carcinogen and [methyl-3H]thymidine was injected s.c. into an isolated portion of the skin clamped off with ring-shaped forceps. Dose-dependent unscheduled DNA synthesis was clearly demonstrated as silver grains on the nuclei of both epithelial and dermal fibroblastic cells in this portion of skin in response to treatment with methyl methanesulfonate, 1-methyl-1-nitrosourea, 4-nitroquinoline 1-oxide, and 4-hydroxyaminoquinoline 1-oxide. The range of variability was small among animals and within a single area of skin. These findings suggest that this system should be useful for quantitative measurement of unscheduled DNA synthesis in individual cells of the skin in vivo. Unscheduled DNA synthesis in response to various carcinogens was 3- to 5-fold more active in epithelial cells than in dermal fibroblastic cells. A time course study showed that active unscheduled DNA synthesis could be detected after 10 min, implying that adduct removal with resulting synthesis had occurred by this time.

Animals↗
PubMed1982

[Protective effect of CoQ 10 administration on cardial toxicity in FAC therapy].

An unique combination treatment for cancer patients has been attempted in our department. The treatment consists of 500 rad irradiation of cobalt 60 on the first day and drip infusion of mixture of 50mg adriamycin, 500mg cyclophosphamide and 500mg 5-fluorouracil on the next day. This combination therapy was repeated every 3 weeks. The myocardial intoxication may be a great problem in this therapy. Investigation was performed in 40 cancer patients in order to clarify of Coenzyme Q10 (CoQ10) could show any protecting effect upon the possible myocardial intoxication. All patients were divided into 2 groups; one with CoQ10 of 20 patients, who received CoQ10 of 90mg/day orally and the other without CoQ10 of 20 patients. In the group without CoQ10, cardiothoracic ratio (CTR) and pulse rate increased significantly in all patients and on ECG low voltage of QRS complex was seen in 2 cases, changes of ST-segment, T-wave and appearance of arrhythmia were more than frequent in the group without CoQ10 than that with CoQ10. It is concluded that CoQ10 is effective for protecting the myocardium in this cancer therapy.

Adult↗
PubMed1981

Immunopotentiating activity of whole cells and mini-cells of Salmonella typhimurium.

Salmonella typhimurium strain 9 produces mini-cells during cell proliferation. Mini-cells are viable but cannot proliferate since they do not contain chromosomal DNA. Effects of whole cells and mini-cells of S. typhimurium on the immune responses were investigated, with the following results. Phagocytosis of peritoneal macrophages was enhanced by in vivo stimulation of both whole cells and mini-cells. Cellular immunity against L1210 cells (mouse leukemia cells) and Sarcoma 180 cells was also enhanced by both whole cells and mini-cells. Mini-cells slightly stimulated in vitro blast cell transformation of normal mouse lymphocytes. Whole cells of S. typhimurium induced antibody-forming cells to produce IgG of higher affinity but mini-cells did not. Mini-cells were not directly cytotoxic for normal lymphocytes or L1210 cells.

Adjuvants, Immunologic↗
PubMed1981

Spontaneously induced suppressor cells in vitro: nonspecific suppression of in vitro antibody formation.

Nonspecific suppressor cells were induced during in vitro culture of normal mouse spleen cells (SPC) using the Marbrook culture system. The suppressor cells inhibited both the primary and secondary antibody-formation responses antigen nonspecifically in vitro, and both IgM- and IgG-responses were inhibited. The supernatants from suppressive precultured cells were not suppressive. The suppressor cells also inhibited the response of allogeneic SPC beyond H-2 compatibility. The induction of the suppressor cells did not require the presence of antigen but required fetal calf serum (FCS) or both FCS and 2-mercaptoethanol (2-ME). The suppressor cells were generated from the nylon-wool adherent, radiation-sensitive T cell population. On the other hand, the suppressor cells were nylon-wool nonadherent, relatively radiation-sensitive T cells. Actively antibody-producing cells were not affected by the suppressor cells. The suppressor cells inhibited the mitogenic responses of normal SPC to phytohemagglutinin-P (PHA), bacterial lipopolysaccharide (LPS) and concanavalin A (Con A). The suppressor cells themselves inhibited the growth of EL4 cells (T-cell leukemia of C57BL/6 mouse origin) and MOPCll cells (B cells, plasmacytoma of BALB/c mouse origin) even at a low effector-to target cell ratio (E:T ratio = 1:1), but did not kill these tumor cells. These results indicate that the target cells of the suppressor cells are both T and B cells, and that the mechanism of action of the suppression is either inhibition of proliferation or inhibition of early events in the course of the immune response.

Animals↗