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Biomedical subjects

I Azuma

Publications and source records attributed to I Azuma.

At least 325 records · Page 18Linked to original sources

Suppression by Nocardia rubra cell wall skeleton mammary DNA synthesis, plasma prolactin level, and spontaneous mammary tumorigenesis in mice.

The effects of the cell wall skeleton of Nocardia rubra on mammary gland DNA synthesis, plasma prolactin levels, and spontaneous mammary tumorigenesis in mice were studied. Female SHN mice received s.c. injections of 100 microgram N. rubra cell wall every 7 days between 2 and 12 months of age. The treatment resulted in the marked inhibition of mammary tumorigenesis; incidence was significantly lower in the experimental mice than in the controls except at 9 and 12 months of age. The age of onset of mammary tumors was significantly higher in the former than in the latter. In association with these findings, the treatment also reduced normal mammary gland DNA synthesis and prolactin levels in the circulation, both of which are primary factors for mammary tumorigenesis.

Age Factors↗

Effect of BCG cell-wall skeleton immunotherapy on the peripheral blood lymphocytes in patients with lung cancer after radiotherapy.

The effect of radiotherapy on peripheral blood lymphocytes (PBL) of lung cancer and the effect of BCG cell-wall skeleton (BCG-CWS) on recovery of impaired PBL were examined. A remarkable depression of the absolute number of E- or EAC-rosette cells and of the response of PBL to mitogens were observed immediately after radiotherapy, and these continued for several months. With BCG-CWS immunotherapy, the response of PBL to phytohemagglutinin recovered rapidly, compared with non-vaccinated patients. The response of PBL to pokeweed mitogen seemed to give similar results. These results suggested that BCG-CWS injection to the patient receiving radiotherapy was effective for recovery of T-cell response.

Adenocarcinoma↗

Structural and immunochemical studies on D-arabino-D-mannans and D-mannans of Mycobacterium tuberculosis and other Mycobacterium species.

Serologically active D-arabino-D-mannas ([alpha]D, +82 degrees approximately 89 degrees; ratio of D-arabinose to D-mannose, 1-2:1) were isolated from the soluble fraction of disintegrated cells of M. tuberculosis, M. smegmatis, and several other Mycobacterium species. These arabinomannans had similar structures, consisting of alpha-(1 leads to 5)-linked D-arabinose residues and alpha-(1 leads to 6)-, and (1 leads to 2)-linked D-mannose residues. Methylation and enzymic degradation studies using Arthrobacter sp. alpha-D-mannosidase and M-2 enzyme (D-arabinan hydrolase) indicated that the arabinomannan of M. tuberculosis Aoyama B possesses short side chains built up from alpha-(1 leads to 2)-D-mannosidic linkages which are attached to an alpha-(1 leads to 6)-linked mannan back-bone chain. The alpha-(1 leads to 5)-linked D-arabinose residues located in the side chains were shown, by comparison of the immunochemical activities of the native and enzyme-degraded polysaccharides, to be the main immunodeterminants, as in the cell-wall arabinogalactan. There appeared to be variations in the ratio of arabinose and mannose residues, and also in the proportion of (1 leads to 2)-linked D-mannose units, depending on the individual strain; no (1 leads to 2)-mannosidic linkage was found in M. smegmatis arabinomannan. In addition to arabinomannan, a serologically inactive alpha-D-mannan ([alpha)D, +65 degrees approximately 68 degrees), whose structure may resemble that of the core mannan of the arabinomannan, was isolated as a copper hydroxide complex from the soluble fraction of disintegrated mycobacterial cells.

Arabinose↗

Macrophage dependency of T-lymphocyte mitogenesis by Nocardia rubra cell-wall skeleton.

The mitogenic activity of the cell-wall skeleton (CWS) of Nocardia rubra on purified splenic T-cells (thymus-derived lymphocytes) was investigated. N. rubra CWS showed remarkable mitogenic activity on normal spleen cells of C57BL/6J mice at concentrations ranging from 10 to 100 microgram per milliliter of culture medium, while, on purified splenic T-cells, N. rubra CWS did not act as an mitogen at any concentration. However, mitogenic activity of N. rubra CWS on T-cells was restored if purified splenic T-cells was reconstituted with X-irradiated peritoneal exudate cells (macrophages). The above results suggest the necessity of macrophages for T-lymphocyte activation by N. rubra CWS as well as PHA-P or Con A.

Animals↗

Mitogenic activity of the cell walls of mycobacteria, nocardia, corynebacteria and anaerobic coryneforms.

The mitogenic activity of the cell walls prepared from Mycobacterium bovis BCG, Nocardia rubra, Corynebacterium diphtheriae PW8, and four species of Propionibacterium, Corynebacterium parvum ATCC 11829, Propionibacterium acnes C7, Propionibacterium granulosum ATCC 25564 and Propionibacterium avidum ATCC 25577, were investigated. These cell walls were active as mitogens on normal spleen cells, anti-O sera-treated spleen cells, macrophage-depleted spleen cells of C57BL/6J mice and cortisone-treated thymocytes of C57BL/6J mice. It was also shown that these cell walls were mitogenic on spleen cells and macrophage-depleted spleen cells of congenitally athymic (nude) mice. The above results suggest that the cell walls investigated in this study act as mitogens on both thymus-derived lymphocytes (T-cells) and bone marrow-derived lymphocytes (B-cells).

Animals↗

Immunotherapy of cancer with cell wall skeleton of Myocabacterium bovis-Bacillus Calmette-Guérin: experimental and clinical results.

Adjuvant and antitumor activities of CWS prepared from cells of mycobacteria, nocardia, and corynebacteria were examined. Oil-attached CWS of M. bovis BCG (BCG-CWS) stimulated the generation of cell-mediated cytotoxic effector cells in mice. Tumor growth was suppressed in mice inoculated intradermally with a mixture of oil-attached CWS and living tumor cells. Systemic and specific tumor immunity was demonstrated in mice in which tumor growth was suppressed. Tumor growth was also suppressed by oil-attached CWS of BCG or N. rubra in autochthonous autografts of spontaneous mammary adenocarcinoma and methylcholanthrene-induced fibrosarcoma in mice. The intravenous injection of oil-attached BCG-CWS prevents the appearance of lung cancer in rabbits by the instillation of chemical carcinogens. It was also shown that treatment with oil-attached BCG-CWS was able to elevate the immunologically depressed state of tumor-bearing mice to a normal level, as determined by a cell-mediated cytotoxicity assay that empolyed chromium release as the standard. Preliminary results suggest that oil-attached BCG-CWS is useful as an immunotherapeutic agent for both lung cancer and for malignant melanoma, leukemia, Hodgkin's disease, and other neoplastic diseases and that this agent operates without any significant complications.

Animals↗

Adjuvant effect of cord factor, a mycobacterial lipid.

Cord factor was a good adjuvant in mice and rats but exerted little if any adjuvant effect in guinea pigs. In rats, cord factor not only enhanced antibody production but also induced delayed hypersensitivity. Wax D was a weak adjuvant in mice. Cord factor caused a marked inflammatory swelling at the sites of injection in mice, but it caused no such swelling in rats and guinea pigs.

Adjuvants, Immunologic↗