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Biomedical subjects

M Mitani

Publications and source records attributed to M Mitani.

At least 91 records · Page 5Linked to original sources
PubMed1985

The role of cytostasis in antitumor immunity: comparison between syngeneic and allogeneic systems.

Different aspects of the immune response differ with respect to sensitivity of neonatal thymectomy (NTx). The effect of thymectomy on Days 1 and 7 after birth (NTx-1, NTx-7) on antitumor immune responses to both a syngeneic and an allogeneic tumor graft was examined. The tumor used was the same, Meth A fibrosarcoma of BALB/c origin, but the mice inoculated differed. The results show that the immune response to a syngeneic tumor graft is primarily cytostatic rather than cytolytic and is relatively insensitive to neonatal thymectomy, while the response to a large dose of allogeneic tumor cells includes a cytolytic mechanism of high thymus dependence.

Animals↗
PubMed1985

Metabolism of idebenone (CV-2619), a new cerebral metabolism improving agent: isolation and identification of metabolites in the rat and dog.

Metabolic studies of idebenone (CV-2619), a new cerebral metabolism improving agent, in the rat and dog by thin-layer chromatography, gas-liquid chromatography-mass spectrometry and fast atom bombardment-mass spectrometry led to characterization of the following metabolites: the parent compound, 6-(9-carboxynonyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (QS-10), 6-(7-carboxyheptyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (QS-8), 6-(5-carboxypentyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (QS-6), 6-(3-carboxypropyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (QS-4), 1- or 4-phenyl sulfate of the hydroquinone derivatives of CV-2619 and QS-4, and 1- and 4-phenyl glucuronides of the hydroquinone derivative of QS-10. These results indicated that CV-2619 was metabolized by oxidation of the side chain followed by beta-oxidation to form successively QS-10, QS-8, QS-6 and QS-4, and reduction of the quinone ring and subsequent conjugation yielding the sulfates and glucuronides of the hydroquinone derivatives of CV-2619, QS-10, QS-8, QS-6 and QS-4.

Animals↗
PubMed1985

Rejection of syngeneic tumor cells by the interaction of Lyt-1+ T lymphocytes and macrophages.

A high degree of cytostatic activity was detected in peritoneal exudate cells (PEC) from BALB/c mice immunized with mitomycin C-treated Meth A cells (MMC-MA) given intraperitoneally (i.p.) While this cytostatic activity was not detected in a nonadherent fraction of immune PEC, the addition of starch-induced PEC to the nonadherent immune cells led to a cytostatic activity. Treatment of these nonadherent cells with anti-Thy-1 X 2 or anti-Lyt-1 X 2 antibody plus complement abolished the restored cytostatic activity. Normal PEC were also rendered cytostatic after addition of the culture supernate of a nonadherent fraction of immune PEC mixed with MMC-MA. These findings suggest that macrophages are rendered cytostatic by immunization with tumor antigen and that these cytostatic macrophages evolve after activation of sensitized Lyt-1 positive T lymphocytes.

Animals↗
PubMed1984

[Antitumor activity of schizophyllan (SPG) against syngeneic ACI/N rat tumor, AMC-60 fibrosarcoma and BC-47 bladder cancer].

The antitumor activity of schizophyllan (SPG) against syngeneic ACI/N rat tumor, AMC-60 fibrosarcoma and BC-47 bladder cancer was investigated. Intramuscular injection of SPG caused a marked suppression of AMC-60 tumor growth. Results obtained with cytotoxicity tests in vitro and lymphoblastogeneic response in vitro suggest the association of enhanced macrophage cytostasis and high reactivity of lymphoid cells with the resistance of the host to AMC-60 tumor. Moreover, SPG showed pronounced antitumor activity against BC-47 bladder cancer. The highest therapeutic effectiveness was obtained when SPG injection was started at an advanced stage of the tumor, 4 out of 15 rats treated being completely cured of cancer. Cytotoxicity tests in vitro and neutralization tests in vivo indicated the important role of cytotoxic lymphocytes as well as activated macrophages in the host defence mechanism against BC-47 cancer. This, taken together with the fact that the rats cured completely by SPG therapy acquired transplantation resistance to BC-47 cancer, shows that SPG may promote tumor immunity in the host.

Animals↗
PubMed1984

[Three operated cases of synchronous double cancers in the lung and stomach. A review of the Japanese literature].

We encountered three patients with synchronous double cancers in the lung and stomach. Although the gastric cancers were resected curatively in all three patients, the lung cancers were resected palliatively because they were too advanced for curative resection. In the Japanese literature we found 25 operated cases of synchronous double cancers and 24 operated cases of metachronous double cancers in the lung and stomach. Early diagnosis and curative resection of both cancers improve the survival rate of these primary double cancers.

Adenocarcinoma↗
PubMed1983

[Human yolk sac tumor of the thymus heterotransplanted into nude mice].

A human yolk sac tumor of the thymus (YSK-1) was transplanted into athymic nude mice. Histological and ultrastructural investigations revealed that the YSK-1 tumor, even after serial transplantation in nude mice, characteristically displayed Schiller-Duval bodies, endodermal sinus structures and ultrastructural profiles, numerous microvilli, desmosome-like cell attachments, annulate lamellar structures, many lipid droplets and interspersed glycogen particles. Serological study by radioimmunoassay demonstrated AFP, CEA, HCG, alpha 1-AT and transferrin in the sera and cyst fluid of the tumor-bearing nude mice. Immunohistochemical investigation using the PAP method showed that the YSK-1 cells produced CEA, HCG, alpha 1-AT, transferrin as well as AFP. The increase in the level of AFP paralleled the increase in tumor size.

Adult↗
PubMed1982

[Experimental study on immunochemotherapy using schizophyllan].

Immunochemotherapy with schizophyllan (SPG) combined with chemotherapeutic agents was evaluated in two syngeneic tumor-C3H/He mouse systems. The administration of SPG alone caused a significant growth inhibition of MM 46 mammary carcinoma, the highest therapeutic effect being obtained by SPG given at the advanced stage of tumors. When combined with neocarzinostatin given 7-times every other day the simultaneous administration of SPG produced an optimal response to that therapy. In X-5563 plasmacytoma, SPG alone was ineffective. However, when combined with mitomycin C given with 1 to 5-days interval, the concurrent administration of SPG prolonged significantly the life-span of the tumor-bearing mice. These results indicated that the simultaneous administration of SPG and antitumor drugs may be a useful application method for immunochemotherapy of experimental tumors.

Adjuvants, Immunologic↗
PubMed1981

Functional recovery and orthopedic management of brachial plexus palsies.

Functional recovery in 133 patients with brachial palsy is documented over a five-year period. Clinical examination is more reliable than electromyogram or myelogram for obtaining prognostic information. Erb's C V, VI palsies have improved function with cuff transfers and elbow flexor plasties. Posterior cord palsies often require extension plasties of the hand and glenohumeral fusions. C V, VI, VII palsies may require all of these procedures. Klumpke C VIII-T I palsies develop arm-trunk holding power. Adults with total palsies often complain of continued pain, which may be relieved by orthoses.

Adolescent↗
PubMed1978

Studies on the ionophorous antibiotics. XV The monovalent cation selective ionophorous activities of carriomycin, lonomycin and etheromycin.

The cations selectivity profiles of the carboxylic ionophores, carriomycin, lonomycin and etheromycin, have been investigated by measuring the complexation affinities for metal cations and the cation transport activity through an organic barrier. In a two-phase partition study, carriomycin and lonomycin formed complexes more readily with K+ than with NH4+, Rb+ or Na+, but not with Li+ or Cs+. On the other hand, etheromycin exhibited a great preference for K+ or NH4+ over Na+, Li+ or Rb+, but displayed no binding affinity for Cs+. The alklaine degradation product of lonomycin exhibited a preference for K+ or Na+, but its complexation affinities were much lower than those of the parent compound. Carriomycin, lonomycin and etheromycin efficiently transported K+, Rb+ and Na+ through a CCl4 barrier. But did not carry Ca2+. These antibiotics caused a massive release of K+, Rb+ or Na+, but not of Li+ and Cs+, from mitochondria previously loaded with these cations by valinomycin or monazomycin. Thus, it is concluded that carriomycin, lonomycin and etheromycin are monovalent cation selective ionophores.

Animals↗
PubMed1978

Studies on the ionophorous antibiotics. XVI. The ionophore-mediated calcium transport and concomitant osmotic swelling of mitochondria.

The effects of various carboxylic ionophores on divalent metal cation translocation in mitochondria have been investigated. High levels of divalent cation ionophores lysocellin and lasalocid A (10 approximately 50 micrometer) produced mitochondrial osmotic swelling in Ca2+ or Mg2+ medium, which was associated with an increase of cation influx. The extent of swelling was a function of both the ionophore and cation concentrations in the medium. This effect was larger in mitochondria de-energized by treatment with antimycin A and oligomycin than in respiring mitochondria. On the other hand, the monovalent cation ionophores carriomycin and etheromycin at concentrations of 50 approximately 100 micrometer also induced mitochondrial swelling in Ca2+ medium but were ineffective in Mg2+ medium. Addition of ruthenium red reversed divalent cation ionophore-induced swelling and released Ca2+ from preloaded mitochondria. In contrast, ruthenium red increased monovalent cation ionophore-induced swelling. In a divalent cation-free medium, lysocellin and lasalocid A caused depletion of membrane-bound Ca2+ and released endogenous Ca2+ and Mg2+ from mitochondria, while carriomycin and etheromycin exerted only a limited effect. These results indicate that the divalent cation ionophores affect divalent cation distribution in mitochondria by increasing both influx and efflux of the cations through the inner membrane.

Animals↗