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Biomedical subjects

M Kimoto

Publications and source records attributed to M Kimoto.

At least 181 records · Page 10Linked to original sources
PubMed1986

Immunopharmacological study of CCA (Lobenzarit disodium), an anti-arthritis agent--I. Abrogation of IL 1 secretion by LPS-stimulated human monocytes and induction of gamma-interferon production with CCA.

In vitro effects of CCA, an anti-arthritis agent, were studied upon autologous mixed lymphocyte reaction (AMLR), lymphocyte mitogenesis, IL 1 and IL 2 production, immunoglobulin production and gamma-interferon (IFN) production. CCA at 50 micrograms/ml, which was not toxic to cells, blocked AMLR, IL 1 production and immunoglobulin production (IgM and IgG) significantly, while CCA at the same dose did not affect IL 2 production and lymphocyte mitogenic responses to Staphylococcus aureus Cowan I(SAC) and pokeweed mitogen(PWM). CCA at both 20 ng/ml and 20 micrograms/ml induced human gamma/IFN. Addition of IL 1 and/or IL 2 reversed inhibitory effect of CCA on AMLR. These data suggest that CCA exerts its actions by mainly affecting T cells and monocytes and can be used as an immunomodulator.

Humans↗
PubMed1986

One I region restriction determinant can associate with multiple antigenic epitopes.

Studies presented in this paper show that T cell clones recognizing different epitopes of multideterminant antigens can be restricted by the same I-A molecule. These data further support the concept that a single I-A restriction site can present more than one antigenic epitope. This concept was supported by data on the proliferation of T cell clones reactive with either poly(L-Glu60, L-Ala30, L-Tyr10)n(GAT) or poly(Tyr, Glu)-poly D,L-Ala--poly Lys [(T,G)-A--L] which recognized different epitopes on these multideterminant antigens. Two clones recognizing different epitopes on the same multideterminant antigen can be blocked by the same monoclonal anti-I-A antibody. Additionally, the mutation in the Abm12 chain utilized in [B6.C-H-2bm12(bm12) X B10.A(4R)]F1 mice can affect the restriction determinant of clones recognizing different antigenic epitopes. These results suggest that in the strictest sense, the determinant selection theory is not tenable and would support the concept that T cell specificity is controlled by the T cell repertoire.

Animals↗
PubMed1986

Bacteriocinlike killing action of a temperate bacteriophage phiBA1 of Bacillus aneurinolyticus.

A new temperate phage, phiBA1, was isolated from Bacillus aneurinolyticus, phiBA1 had an icosahedral head with a diameter of about 70 nm and a tail about 20 nm long and contained a circularly permuted, linear duplex DNA of about 38 x 106 daltons. This phage showed two activities: bacteriocin-like killing activity against five strains of B. aneurinolyticus and normal temperate phage activity against three other strains. phiBA1 killed sensitive cells by a single-hit process. After adsorption of phiBA1 to cells sensitive to killing, the content of intracellular ATP increased for the first 5 min and then gradually decreased. Phage DNA injected into the cell immediately after infection was degraded rapidly. Killing was also caused by heavily UV-irradiated phiBA1. Killing-resistant mutants showed normal adsorption of phiBA1 and normal injection of the DNA with its instantaneous restriction. Our results indicate that the killing action of phiBA1 is different from the phenomenon of abortive infection and suggest that the killing might be caused by a proteinaceous component of phiBA1.

Bacillus↗
PubMed1985

Membrane-bound lipoxygenase of rat cerebral microvessels.

The microvessels isolated from rat cerebral cortex has arachidonate lipoxygenase activity, which was not due to possible contamination of the platelets. The major product was identified to be 12-hydroxyeicosatetraenoic acid. After homogenization and sonication of the microvessel preparations, the lipoxygenase activity was recovered both in the membrane- and the cytosol-fractions, whereas that in the platelets was recovered in the cytosol fraction. Membrane-bound lipoxygenase of the microvessels has apparent Km value of 3.8 microM for arachidonic acid, which was corresponded to 1/5 of that in the platelet enzyme. Microvessel lipoxygenase was inhibited by nordihydroguaiaretic acid but not by indomethacin.

Animals↗
PubMed1985

IgM induction in murine B hybridomas with Ia-restricted T cell clones: a monoclonal model for T and B cell interactions in antibody response.

The mechanism of MHC-restricted T and B cell interactions in antibody response was studied with IgM-inducible B hybridomas and antigen-specific helper T cell clones. B hybridomas were prepared by fusion between splenic B cells from (CBA/N (H-2k) X BALB/c (H-2d)) F1 (NBF1) male mice and a B lymphoma cell line, M12.4.5. A B hybridoma clone, 1M70, which expressed I-Ad but not I-Ak determinants was chosen in the present study. IgM secretion was induced in 1M70 when it was cocultured with a "resting" KLH-specific and H-2d restricted helper T cell clone in the presence of KLH. A "resting" KLH-specific and H-2k restricted T cell clone did not induce IgM secretion in 1M70 even in the presence of KLH. However, when these KLH-specific T cell clones were activated by KLH and appropriate antigen presenting cells, both H-2d and H-2k restricted T cell clones induced IgM secretion in 1M70 even in the absence of KLH. A monoclonal anti-I-Ad antibody inhibited IgM secretion induced by a "resting" H-2d restricted T cell clone, but not by an "activated" T cell clone. These results indicated that T cell clones recognized antigens in the context of Ia molecules on B hybridomas in a MHC-restricted manner and were activated to produce B cell stimulatory factors which in turn acted on B hybridomas in a non-MHC-restricted manner and induced differentiation of B hybridomas into IgM secreting cells.

Animals↗
PubMed1984

Distribution of protein-bound zinc in serum of analbuminemic rat.

The distribution of protein-bound zinc in serum of rat with analbuminemia was analyzed with gel filtration and affinity chromatography. From the profiles of chromatography, the zinc present in analbuminemic rat serum is composed of two principal species in similar to that of Sprague-Dawley rat: one fraction is firmly bound to alpha 2-macroglobulin, and a second fraction is more loosely bound to various proteins.

Animals↗
PubMed1984

Polyclonal activation of xid B cells by auto-Ia-reactive T cell clones.

The mechanism of T cell-dependent activation of xid B cells into Ig-producing cells was studied by employing H-2-restricted, antigen-specific T cell clones. Helper factors (B cell stimulatory factors, BSF) released from KLH-specific T cell lines could induce polyclonal Ig production in B cells from (CBA/N X BALB/c)F1 (NBF1) female mice but not from CBA/N or NBF1 male mice. Direct addition of helper T cell lines induced Ig production in xid B cells from CBA/N or NBF1 male mice. A T cell clone, MK6, which was derived from NBF1 male mice and specific against Iad determinant, could activate NBF1 male but not CBA/N B cells. Another clone, CK4, derived from CBA/N mice and having specificity against KLH plus I-Ak determinant could activate both CBA/N and NBF1 male B cells into IgM- and IgG-producing cells in the absence of KLH, and monoclonal anti-I-Ak antibody specifically blocked such activation. These results suggest that xid B cells are able to be activated by the signal provided by the recognition of Ia molecules on B cells by auto-Ia-reactive T cells. Xid B cells from CBA/N mice that had been co-cultured with a T cell line specific against I-Ak determinant for 24 hr became reactive to BSF and capable of differentiating into Ig-producing cells in the presence of BSF. The results showed that even xid B cells could be responsive to BSF if they were in a certain activation stage.

Animals↗
PubMed1983

[Effect of BCG (Bacillus Calmette Guérin) sensitization on the generation of tumor specific killer T cells].

Effector cells of augmented resistance against a syngeneic MC-1 tumor in C57BL/6 mice sensitized with BCG were determined by Winn test, and the following results were obtained: Sensitization of mice with BCG (1.0 mg/mouse) augmented resistance against primary and secondary inoculation of MC-1 tumor. Peritoneal exudate cells of tumor-bearing mice showed a growth-inhibitory activity against MC-1 tumor in Winn test. Sensitization with BCG augmented such an activity of PEC. Augmented resistance was ascribed to a plastic dish-nonadherent, nylon wool column-nonadherent and Thy 1.2-positive cells.

Animals↗