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Biomedical subjects

N Kumano

Publications and source records attributed to N Kumano.

At least 37 records · Page 2Linked to original sources
PubMed1983

Chemical analyses and antitumor activity of hydrosoluble substances from Mycobacterium bovis, strain BCG.

Hydrosoluble substances from BCG were prepared by cold water extraction and by hot phenol-water extraction. Chemical analyses revealed that both of them were derived from cytoplasm. The cold water extract (CWE) was effective in the treatment of C3H/He mice which had received an intraperitoneal inoculation of a syngeneic ascites hepatoma, MH134. The growth of a graft in footpad of mastocytoma P815 in CDF1 mice was retarded by intraperitoneal injections of CWE. A peptidoglycan from cell wall prepared by digestion with lysozyme exerted no antitumor activity in the same experimental condition as for the evaluation of antitumor effect of CWE. These results indicate that the antitumor activity of CWE was not due to the presence of a cell wall component.

Animals↗
PubMed1982

Ultrastructure of the Lewis lung carcinoma.

ELectron microscopic observations were made on the Lewis lung carcinoma, which has frequently been used in various experiments. Although the tumor cells had desmosomes, interdigitation, microvilli and basement membranes which were of epithelial nature, they did not show either squamous or adenomatous differentiation. On the basis of microscopic and ultrastructural findings, this tumor falls into the category of large cell carcinomas. At the periphery of the tumor, sinusoidal clefts between the strands of tumor cells contained many red blood cells without fibrin. While perfect blood vessels were observed towards the center of the tumor, large necrotic areas were observed. Dilated large vessels possessed some endothelial fenestrations. Light endothelial cells were also observed, which were penetrated by red blood cells. Interstitial components were very scant and collagen fibres were frequently observed to be dissolved.

Animals↗
PubMed1982

Mitogenic effect of the mannans from Saccharomyces cerevisiae on mouse spleen lymphocytes.

The DNA synthetic activities of mannans isolated from two Saccharomyces cerevisiae strains were examined in vitro using spleen cells obtained from normal or nude BALB/c strain mice. A highly branched mannan isolated from the S. cerevisiae wild type strain induced a greater increase in mitogenic activity than those displayed by the mannan of the S. cerevisiae X2180-1A-5 mutant strain which possessed fewer branching moieties. Acid-hydrolyzed wild type strain mannan with two-thirds of the molecular weight of the parent intact mannan showed weak mitogenicity. Increases in the DNA synthetic activities of nude and normal spleen cells were almost the same as that of wild type strain mannan, while nylon wool column-passed spleen cells obtained from both normal and nude mice did not show mitogenicity with this mannan. The results indicated that the mitogenic activity was responsible for the highly branched structure of the wild type strain mannan, and that this mannan is a B-cell mitogen.

Animals↗
PubMed1982

Evidence for host-mediated antitumor activity in the treatment of experimental tumor with a hot water extract from BCG.

Studies were undertaken for the evaluation of the mechanism responsible for antitumor effects of hot water extract (HWE) of BCG on murine ascites tumor cells. a) The viability of tumor cells has remained unchanged after incubation of tumor cells in the medium containing HWE. b) There was no difference in survival time between mice which had received tumor cells treated as in (a) and the control mice. c) Silica, carragheenan and cortisone acetate reduced the antitumor effect of HWE in ddY mice and C3H/He mice which had been inoculated with Sarcoma 180 cells or MH134 cells. d) The growth of tumor cells was retarded when they were inoculated subcutaneously together with peritoneal cells from HWE-injected mice. These results indicate the participation of host-mediated antitumor activity when neoplasms were treated with HWE.

Animals↗
PubMed1981

Chemical and biological properties of subfractions of hot-water extract from delipidated BCG.

a hog-water extract from delipidated Mycobacterium bovis strains BCG was fractionated by precipitation with ethanol. The chemical and biological properties of the subfractions thus obtained were investigated. A subfraction precipitated at 20% ethanol contained less neutral sugar and more ninhydrin-positive substance than other subfractions. Only the guinea pigs that were treated with 20% ethanol-precipitate showed no humoral antibody response to egg white albumin, despite positive skin reaction. The subfractions precipitated at low concentrations of ethanol exhibited a significant antitumor activity in ddY and C3H He mice inoculated intraperitoneally with tumor cells. These results suggest that the hot-water extract from delipidated BCG consists of subfractions with different chemical and biological properties.

Adjuvants, Immunologic↗
PubMed1981

Prophylaxis of 3-methylcholanthrene-induced tumorigenesis in mice with the yeast polysaccharide preparation.

Prophylaxis of 3-methylcholanthrene-induced epithelial tumor formation in ddI mice with our Candida utilis glucomannan preparation (YPS) was confirmed further in the present system of fibrosarcoma production. A single subcutaneous dose of MCA (0.5 mg per mouse) was either preceded by or followed by 10 or 30 daily intraperitoneal (i.p.) injections of YPS at the dosage of 100 mg/kg per dose according to various time schedules. Protective effect of YPS was demonstrable by a significantly lengthened latent period before the tumor appearance and a slower rate of the subsequent tumor production until around day 100. All the schedules of pre- or post-treatment were found to be effective, although the one delayed until two weeks post MCA was so only marginally. It was also disclosed by prolonging the observation period that this protection was of a transient nature, 100 per cent tumor incidence being found by around 150 days post MCA in all the experimental groups. A longer latency due to the treatment with YPS was generally found in association with a faster growth of the tumor and a shorter life span of the host animal. Temporary protection of MCA-induced tumorigenesis in ddI mice was not reproducible in C3H/He mice, and was thus suggested the possible strain-dependent nature of YPS effect.

Adjuvants, Immunologic↗
PubMed1979

A biological study on hot-water extract from delipidated Mycobacterium bovis strain BCG.

The biological activity of a hot-water extract from delipidated BCG, designated as HSA (Hot-water Soluble Adjuvant), was investigated. The HSA did not induce hyperreactivity to bacterial endotoxin. The hot-water extract from which nucleic acids had been removed by streptomycin (SM-HSA) was found to enhance the delayed-type hypersensitivity as evidenced by the results of footpad reaction of mice. The HSA and SM-HSA could be injected to mice by an intraperitoneal route for 20 consecutive days without undesirable side effects. A comparative study was made on the effects of HSA in relation to the duration and doses of treatment with HSA using the ddI mice inoculated with Sarcoma-180. The most remarkable effect was observed when 0.25 mg of HSA had been injected for 20 consecutive days. Also SM-HSA was found to exert antitumor activity when applied in the same manner as above. These results suggest that the presence of nucleic acids is not related to the biological and antitumor activities of the hot-water extract.

Adjuvants, Immunologic↗
PubMed1978

Antitumor activity of hot-water extract from delipidated BCG.

The antitumor activity of hot-water extract of delipidated BCG was investigated in mice inoculated with Sarcoma-180 cells and Ehrlich carcinoma cells, respectively. The hot-water extract was found to be effective when administered after and ineffective when administered before the inoculation of tumor cells. When this extract was given with anticancer drugs, such as Mitomycin C and cyclophosphamide, a combined effect was obtained in the treatment of Sarcoma-180 and of Ehrlich carcinoma.

Adjuvants, Immunologic↗
PubMed1978

[A new method for elimination of artifacts produced by collimator septum effect in gamma-camera images (author's transl)].

Collimator artifacts may be present within the images produced by collimators whose septal width approaches the inherent resolution of the gamma-camera system. As the inherent resolution of the gamma-camera is improved, collimator artifacts become more prominent. The purpose of this study is to eliminate collimator artifacts from gamma-camera images. To eliminate the septum effect produced by high-energy parallel-hole collimators with thick septa, the following method was used: X and Y signals from the detector are made to ride on the triangular waves changing periodically, and resultant position signals obtained by this processing are applied to the corresponding deflection circuits in the CRT display. The oscillation amplitude of processed position signals can be regulated by the frequency and amplitude of the triangular waves. Regulation of the oscillation amplitude of position signals, which would produce maximum reduction of collimator artifacts, was to approach the spatial frequency responses of the overall processed line spread functions obtained experimentally to those of the Gaussian functions with FWHM equal to the geometric resolution calculated from the equation given by Gerber and Miller. In images of a pancreas phantom containing 131I, collimator artifacts were clearly seen in the unprocessed case, but were eliminated in the processed case.

Models, Theoretical↗