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Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 1,423 records · Page 79Linked to original sources
PubMed1985

Sex-dependent induction of hepatic enzymes for mutagenic activation of a tryptophan pyrolysate component, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]-indole, by feeding in mice.

Male and female BALB/c X DBA/2 F1 mice were treated with a diet containing 0.02% 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]-indole (Trp P-1), a hepatocarcinogenic tryptophan pyrolysate component, and the capacities of subcellular fractions of the liver to catalyze the mutagenic activation of Trp P-1 and its analogue Trp P-2 (4-demethylated Trp P-1) were examined by the in vitro Salmonella test with strain TA 98. In mice on control diet, both 9000 X g supernatant (S-9) and microsomal fractions from female mice livers displayed only 1.1- to 1.3-fold higher capacities for the mutagenic activation of either Trp P-1 or Trp P-2 than did those from male mice livers. When mice were treated with the Trp P-1 diet for 1 week, the S-9 activity in male mice for the Trp P-1 mutagenesis did not change, but that in females was increased to 2.5-fold of the female control. Treatment of mice with the dietary Trp P-1 for 2 weeks increased the S-9 activities to 2.8-fold in males and 4.9-fold in females of the same sex controls and the increased S-9 activities were not significantly changed by additional Trp P-1 feeding for 2 weeks. Similar changes in the S-9 activity were observed for the Trp P-2 mutagenesis. The overall changes in the S-9 activities induced by feeding Trp P-1 were reflected in the isolated microsomes. However, microsomes derived from the same volume of S-9 used exhibited only about one-half (Trp P-1) or one-third (Trp P-2) of the activity of the respective complete S-9 mixtures. Addition of liver cytosolic fractions (105,000 X g supernatants) from untreated or Trp P-1-treated mice to microsomes resulted in enhanced activities. Cytosols alone did not activate the compounds to mutagens. The microsome-mediated mutagenicity of either Trp P-1 or Trp P-2 was diminished by removal of NADPH from the assay system. It was also inhibited by addition of 7,8-benzoflavone and to a lesser extent by SKF 525A. Enzyme(s) for the mutagenic activation of Trp P-1 was induced by an i.p. injection of 3-methylcholanthrene to mice and to a lesser extent by an injection of phenobarbital, but no sex differences were observed in these enzyme inductions as opposed to the Trp P-1 feeding.(ABSTRACT TRUNCATED AT 400 WORDS)

Aminopyrine N-Demethylase↗
PubMed1985

[Studies of an assay system for dialyzable leukocyte extracts (DLE)--influence of DLE on leukocyte migration inhibition test by HBsAg].

In order to examine the suitability of leukocyte migration inhibition test (LMIT) in the capacity of in vitro assay system for dialyzable leukocyte extracts (DLE), the effect of DLE on hepatitis B and its antigen-specificity, the migration inhibitory activities to purified hepatitis B surface antigen (HBsAg) was measured using the leukocyte MIF test with DLEs obtained from HBsAb-positive or HBsAb-negative blood. The direct LMIT using agarose plate was modified according to the technique of Clausen et al. In spite of our assay system was dose-dependent for PPD, a significant response for purified HBsAg was not observed. However, some meaningful migration inhibition appeared when HBsAg and DLE were added simultaneously to the migration cells. From these results, it is concluded that DLE has antigen-specific and/or antigen non specific influences to the cell-mediated immunity for HBsAg Though some problems remain, we think our results are interesting, since the assay system for DLE has not been established and our study is closely related to the effect of DLE concerning hepatitis B.

Cell Migration Inhibition↗
PubMed1985

Stimulated rat T cell-derived inhibitory factor for cellular DNA synthesis (STIF). I. Isolation and characterization.

A lymphokine inhibitory for cellular DNA synthesis (termed STIF) was isolated from the culture supernatants of concanavalin A (Con A)-stimulated SD rat spleen cells. STIF inhibited the DNA synthesis of mouse bone marrow cells as well as mouse leukemia cells. STIF has an apparent m.w. of 45,000 to 50,000 and is separable from IL 2, m.w. 20,000 to 25,000, by Sephacryl S-200 gel filtration, but not from immune interferon (IFN) having the same m.w. as STIF. Con A-Sepharose chromatography of the fraction containing STIF and IFN could separate these lymphokines into Con A-unbound and Con A-bound fractions, respectively. Further fractionation of the STIF fraction by DEAE-Sephadex A-50 or Mono Q-FPLC anion exchange chromatography indicated that the STIF fraction contained two components of STIF activity, both showing the same pI value (5.1 to 5.6) on flat-bed isoelectric focusing. STIF was characterized as a sugar-free lymphokine of trypsin-sensitive protein nature.

Absorption↗
PubMed1985

Cytotoxic lymphocytes in rat tumor in situ: effect of intraperitoneal injections of Propionibacterium avidum.

In vitro cytotoxicity against tumor cells of lymphocytes in sc implanted BC47 bladder tumor of ACI/N rats with or without Propionibacterium avidum (P. avidum) treatment was studied. Tumor-associated lymphoid cells (TAL) were obtained from tumor tissues by mechanical treatment (NDi fraction) and by enzymatic treatment with Dispase I, a proteolytic enzyme (Di fraction), followed by passage through glass wool columns to deplete tumor cells. NDi fraction of TAL from P. avidum-treated animals showed a significant cytolytic activity against BC47 cells, but not against other ACI/N bladder tumor cell lines, BC12 and BC50. These TAL lost the cytolytic activity on treatment with anti-rat thymocyte serum or anti-rat T cell monoclonal antibodies, R1-3B3 and R1-10B5, and complement. Natural killer activity determined with YAC-1 cells was low in the cells of NDi fraction and scarcely detectable in the cells of Di fraction from both P. avidum-treated and untreated rats. These results indicate that the antigen-specific cytotoxic T cells in the tumor in situ are induced by in vivo P. avidum treatment. On the other hand, P. avidum treatment augmented nonspecific cytolytic activity of peripheral lymphoid cells such as plastic-nonadherent peritoneal cells, spleen cells and blood lymphocytes in normal and BC47-bearing rats. However, the antigen-specific cytolytic T cells were predominantly induced and recovered in the plastic nonadherent peritoneal cells of BC47-bearing rats by the treatment with P. avidum.

Adjuvants, Immunologic↗
PubMed1985

Human bladder cancer cell-surface antigens recognized by murine monoclonal antibodies raised against T24 bladder cancer cells.

Seven hybridoma clones producing monoclonal antibodies (HBJ8, HBJ27, HBJ67, HBJ71, HBJ98, HBJ104 and HBJ127) were selected from hybridomas prepared by fusion between P3 X Ag8.653 mouse myeloma cells and spleen cells of a BALB/c mouse immunized with T24 human urinary bladder cancer cells, and the binding specificity of, and the molecular characters of the antigens defined by, these monoclonal antibodies were examined. The cell-surface antigens detected with these monoclonal antibodies from T24 bladder cancer cells were as follows: 1) HBJ27-defined gp85 antigen common in all human cells or tissues tested, 2) HBJ98- or HBJ127-defined gp125 antigen distributed in all epithelial and non-epithelial human tumor cell lines tested and in basal layers of the skin or esophagus, proximal tubules of the kidney, and crypts of the gastric and intestinal mucosa, 3) HBJ8-defined gp(40/90) and HBJ67-defined gp83 antigens distributed in a characteristic portion of epithelial tumor cell lines, 4) HBJ71-defined antigen of protein nature and HBJ104-defined antigen of unknown character, both being detected from immunizing T24 cells and a few epithelial tumor cell lines. All these monoclonal antibodies could bind with certain portions of fresh bladder cancer tissues from patients.

Animals↗
PubMed1985

Derivation of a brain tumor-selective monoclonal antibody from hybridoma between mouse myeloma and rat spleen cells immune to syngeneic glioma.

Fischer 344 (F344) rats hyperimmunized with syngeneic 9L/R3 glioma cells produced antibody selective to glioma cells. Hybridomas prepared from the spleen cells of the immunized rat were cloned, and we obtained a hybridoma clone which produced monoclonal IgM antibody, termed FR77, that showed selectivity to glioma cells. Immunoperoxidase staining of cultured cells revealed that FR77 was reactive with 3 lines of rat glioma cells but not with normal F344 rat fibroblasts. Immunohistochemical staining of F344 rat tissue sections with biotinylated FR77 demonstrated that FR77 could bind with glioma tissue developed by intracerebral injection of 9L/R3 glioma cells but not to normal parts of the brain tissues and other normal tissues tested. The FR77-defined antigen was observed to be mainly localized in cytoplasm of glioma cells but a small portion of the antigen was also detected on the glioma cell surface.

Animals↗
PubMed1985

A new morphologically characterized cell wall preparation (whole peptidoglycan) from Bifidobacterium infantis with a higher efficacy on the regression of an established tumor in mice.

Three kinds of morphologically distinct cell wall preparations were isolated from heat-killed Bifidobacterium infantis and examined for the relative antitumor efficacy with syngeneic Meth A fibrosarcoma in BALB/c mice. Ultrastructural examinations revealed that cell wall skeleton (CWS) did not retain morphologically recognizable cell wall structure but showed fibrous structure. By contrast, a new cell wall preparation, whole peptidoglycan (WPG), which was isolated from whole cells without being subjected to physically destructive methods, completely retained the intact cell wall structure. When WPG was disrupted by sonic treatment, it retained some degree of physical integrity of cell wall structure, as compared with CWS. The results of chemical analysis indicated that the three cell wall preparations had similar chemical properties. A single s.c. injection of either CWS, WPG, or sonicated WPG in a mixture with tumor cells resulted in a significant suppression of the tumor growth. They were of equally high activity. However, when WPG, sonicated WPG, or CWS was injected intralesionally five times into mice bearing 5-day-old tumors, the incidence of complete tumor regression was demonstrated to decrease in the order of 70, 40, and 20%, respectively. The in vitro cytotoxicity test excluded the possibility that the tumor cell destruction was the result of direct cytotoxicity of the cell wall preparations. From these findings, it was concluded that WPG was an active stimulator of host-mediated response at the tumor-growing sites.

Animals↗
PubMed1985

Modulation of reticuloendothelial activity with liposomes.

The effect of multilamellar vesicles (MLV) on reticuloendothelial (RE) activity, as measured by the carbon clearance method, was investigated in mice. MLV were prepared with a mixture of dipalmitoyl phosphatidylcholine, cholesterol and a charged agent (7:2:1 molar ratio). RE activity was moderately depressed shortly (1-4 hr) after i.v. injection of all MLV tested; negatively charged MLV with dicetyl phosphate, positively charged MLV with stearylamine and neutral MLV without a charged agent. In the later time, either MLV with dicetyl phosphate or MLV with stearylamine caused a marked stimulation of reticulo-endothelial system (RES), but neutral MLV did not. A peak of RE activity resulted from the treatment of MLV with dicetyl phosphate appeared 48 hr after injection and then gradually returned to the normal level within 7 days. The depression and the enhancement of RE activity induced by the treatment of MLV with dicetyl phosphate were observed to be dose-related and significant at a dose of 1 mg/mouse and 0.3 mg/mouse, respectively. These results should be taken into consideration upon the use of liposomes as a drug carrier, or for blocking RES.

Animals↗
PubMed1984

Inhibition of indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase by beta-carboline and indole derivatives.

beta-Carboline derivatives inhibited both indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase activities from various sources. Among them, norharman is most potent for both enzymes from mammalian sources. Kinetic studies revealed that norharman is uncompetitive (Ki = 0.12 mM) with L-tryptophan for rabbit intestinal indoleamine 2,3-dioxygenase, and linearly competitive (Ki = 0.29 mM) with L-tryptophan for mouse liver tryptophan 2,3-dioxygenase. In addition, some beta-carbolines selectively inhibited one enzyme or the other. Pseudomonad tryptophan 2,3-dioxygenase was inhibited by a different spectrum of beta-carbolines. Such a selective inhibition by the structure of substrate analogs is more evident by the use of indole derivatives. Indole-3-acetamide, indole-3-acetonitrile and indole-3-acrylic acid exhibited a potent inhibition for mammalian tryptophan 2,3-dioxygenase, while they moderately inhibited the pseudomonad enzyme. However, they showed no inhibition for indoleamine 2,3-dioxygenase. These results suggest the difference of the structures of the active sites among these enzymes from various sources.

Animals↗
PubMed1984

Effects of the ratio of exogenous eicosapentaenoic acid to arachidonic acid on platelet aggregation and serotonin release.

We added arachidonic acid (AA) and eicosapentaenoic acid (EPA) to washed platelet suspensions in the absence of albumin, holding the total amount of the fatty acids constant at 2 microM, and changing the ratio of EPA to AA. Platelet aggregation, serotonin release and the amount of thromboxane (TX) B2, a cyclooxygenase product synthesized from exogenous AA, decreased as the ratio was increased. The decreases were greater than the expected ones from the diminution of the amount of exogenous AA. On the other hand, 12-hydroxyeicosatetraenoic acid (HETE), a lipoxygenase product synthesized from exogenous AA, increased in the presence of EPA. Although EPA was reported to be a poor substrate for platelet cyclooxygenase, the amount of TXB3 synthesized from exogenous EPA increased markedly by the simultaneous addition of AA. These results suggest that the EPA/AA ratio-dependent decrease in platelet aggregation and serotonin release is caused at least by both the decrease in the absolute amount of AA and the inhibitory effect of EPA on AA-metabolism via the cyclooxygenase pathway. Further studies on effects of EPA-metabolites via the cyclooxygenase pathway on platelet responses will be needed.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1984

In vitro translation of infectious flacherie virus RNA in a wheat germ and a rabbit reticulocyte system.

Infectious flacherie virus is an insect picornavirus isolated from the silkworm, Bombyx mori. Its RNA was found to act as an efficient mRNA in a wheat germ extract and a rabbit reticulocyte lysate translation system. In either system the sum of molecular weights of translation products far exceeded the coding capacity of the virus genome, which suggests the occurrence of proteolytic cleavage of large primary products to smaller polypeptides as reported for other picornaviruses and/or premature termination of translation. The highest molecular weight product of 200 000 (polyprotein-like product) could be translated in both systems. One of the antigenic products common to both systems had a molecular weight of 130 000, which corresponds to the sum of molecular weights of the four major viral proteins. Another product, which comigrated with viral protein 0, the largest viral structural protein in SDS-polyacrylamide gel electrophoresis, also showed antigenicity. Peptide mapping of these polypeptides showed that the two in vitro systems translated the same cistron in the viral RNA and that the smaller polypeptide was a part of the 130 000 Da product.

Animals↗