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Biomedical subjects

R Teshima

Publications and source records attributed to R Teshima.

At least 109 records · Page 6Linked to original sources
PubMed1990

The incidence of fractures of the proximal femur and the distal radius in Tottori prefecture, Japan.

We report the incidence of proximal femur and distal radius fractures in Tottori prefecture, Japan. In 1986 and 1987, 573 proximal femoral fractures and 1576 distal radial fractures were registered in this district. The age- and sex-specific incidence rates of these two fractures are lower among Japanese than among European or North American whites, according to previous reports. Thus, it was concluded that the incidence rates of these two fractures are lower in Japanese than in Caucasians.

Adolescent↗
PubMed1990

Characterization of a new type of variant of rat basophilic leukemia 2H3 cells presenting a different pattern of calcium signal.

We selected a new type of variant (designated 3C7) derived spontaneously from parental RBL-2H3 cells. 3C7 cells showed lower contact inhibition, anchorage dependency, and serotonin release activity than those of RBL-2H3 cells. We conclude that 3C7 cells are a transformant of RBL-2H3 cell with greater malignancy. The production of inositol bisphosphate and the release of Ca2+ from intracellular stores induced by IgE-antigen stimulation were enhanced in 3C7. Oscillation of [Ca2+]i in individual 3C7 cells was observed by a digital imaging microscopic technique. We propose that 3C7 cells are a useful model system for studies on the mechanisms of stimulus-secretion coupling and the relationships between malignant alterations and disorders of signal transduction.

Animals↗
PubMed1990

Radioimmunoassay of nivalenol in barley.

Antibodies against nivalenol (NIV) tetraacetate (Tetra-Ac-NIV) were prepared by immunizing rabbits with a hemisuccinate derivative of 8-hydroxy-3,4,7,15-tetraacetyl-12, 13-epoxytrichothece-9-en conjugated to bovine serum albumin. A radioimmunoassay system with one of these sera was developed to measure NIV contamination in barley. The detection limit for Tetra-Ac-NIV was about 0.5 ng/ml. The relative cross-reactivities of the antiserum with Tetra-Ac-NIV, acetyl T-2 toxin, and scirpenol triacetate, which were determined by the competitive radioimmunoassay, were 1, 0.78, and 0.56, respectively. Other derivatives showed no cross-reactivity. For the determination of NIV in a barley sample, NIV was extracted from the sample with acetonitrile-water (7:3), defatted with hexane, and then acetylated with acetic anhydride to form Tetra-Ac-NIV. The reaction mixture was loaded onto a C18 cartridge to remove excess reagents and impurities. Tetra-Ac-NIV was eluted from the cartridge with 50% methanol in water, and the eluate was subjected to radioimmunoassay. Analysis of six naturally contaminated barley samples for NIV revealed that radioimmunoassay results agreed well with gas chromatographic analyses.

Chromatography, Gas↗
PubMed1990

Production and characterization of monoclonal antibodies to nivalenol tetraacetate and their application to enzyme-linked immunoassay of nivalenol.

Three monoclonal antibodies were obtained by the fusion of mouse myeloma cells with splenocytes isolated from BALB/c mice that had been immunized with 8-hydroxy-3,4,7,15-tetraacetyl-nivalenol hemiglutarate covalently bound to bovine serum albumin. These anti-nivalenol tetraacetate monoclonal antibodies were of the IgG type and highly specific to nivalenol tetraacetate, with an apparent association constant of about 10(8)M-1. The relative cross-reactivities of one monoclonal antibody with nivalenol tetraacetate, acetyl T-2 toxin, and scirpenol triacetate were found to be 1.0, 0.02 and 0.03, respectively. Other derivatives showed no cross-reactivity at all. An indirect enzyme-linked immunosorbent assay (ELISA) based on the competitive binding principle was developed using the antibody from clone D18.102.59. The sensitivity of the system was about 0.1 ng of nivalenol tetraacetate per assay. Comparison of nivalenol levels detected in naturally contaminated barley samples by competitive indirect ELISA and gas chromatography (GC) showed good agreement, indicating that the antibody is useful for the measurement of nivalenol in naturally contaminated cereals and grains.

Animals↗
PubMed1990

[Evaluation of immunotoxicity testings using azathioprine-treated rats: the International Collaborative Immunotoxicity Study (Azathioprine)].

The immunotoxicological effects of azathioprine (AZP) were examined by enhanced histopathological and function tests in the rat which is routinely used in toxicological tests. Male F344 rats were orally administered AZP in doses of 0, 2.5, 12.5 and 25.0 mg/kg/day for 28 days. Reductions in the organ weights of the thymus, spleen, liver, kidney, and testis in a dose-dependent manner were confirmed. Hematological examination revealed a marked decrease in the number of WBCs, which was associated with a decrease in the number of lymphocytes. In the femoral bone marrow, a significant reduction in the total cell number attributed to the decrease in the number of lymphocytes and granulocytes was observed. Histopathologically, atrophy and obfuscation of the corticomedullary junction in the thymus, the decrease of lymphocytes in the thymus and spleen, and the disappearance of germinal centers in the lymph nodes were observed. As for the functional testings, azathioprine treatment did not affect remarkably the PFC number and the NK cell activity per unit spleen cell number. However, the total spleen cell number per spleen was decreased in a dose-dependent manner. Therefore, the total functional activities (PFC and NK) per spleen were decreased. Thus, in the AZP-treated F344 rats, it was shown that the enhanced histopathological tests were useful to evaluate potential risks to the immune system.

Animals↗
PubMed1989

Morphine enhances the phosphorylation of a 58 kDa protein in mouse brain membranes.

Morphine and [D-Ala2,D-Leu5]enkephalinamide enhance the phosphorylation of a 58 kDa protein in mouse brain synaptosomal membranes. The enhancement of phosphorylation was inhibited by naloxone, an antagonist of morphine. The phosphorylated 58 kDa protein was retained on wheat-germ-agglutinin-agarose and morphinone-Affi-Gel 401 columns and biospecifically eluted out from the columns with N-acetyl-D-glucosamine and naloxone respectively. These results suggest a strong possibility that the opiate-binding protein undergoes phosphorylation by endogenous protein kinase. Since the molecular mass of a mu-type opioid receptor in mouse brain is suggested to be 58 kDa, coincident with those of rat brain and neuroblastoma x glioma hybrid cells, it is conceivable that the phosphorylated 58 kDa protein is a mu-type receptor.

Animals↗
PubMed1989

Enhancement of the phosphorylation of membrane bound myosin light chain by antigen stimulation in rat basophilic leukemia cells.

We have found that phosphorylation of the 18,000 mol. wt protein in rat basophilic leukemia cells (RBL-2H3 cells) is enhanced by stimulation by an antigen. This phenomenon was also observed when cells were treated with phorbol myristate (TPA) and a calcium ionophor, A23187. The phosphorylated 18,000 mol. wt protein was mainly located in the membrane fraction. It was identified as one of the myosin light chains as follows: (1) the mol. wt of one of the major myosin light chains of RBL-2H3 cells was 18,000; (2) more than half of the phosphorylated 18,000 mol. wt protein was recovered in an actomyosin fraction; (3) this phosphorylated 18,000 mol. wt protein was immunoprecipitated with anti-myosin antibody. Since the presence of Ca2+ in the cell culture medium was essential for the phosphorylation of the 18,000 mol. wt protein and, since trifluoperazine (a potent inhibitor of calmodulin as well as of the degranulation process of RBL-2H3 cells) inhibited the reaction, the phosphorylation may be catalyzed by a Ca2+-calmodulin-dependent process, most likely by myosin light chain kinase. These results, together with our previous observation [Teshima et al. Molec Immun. 23, 279-284 (1986)], suggest that simultaneous phosphorylation of the 18,000 mol. wt myosin light chain and a 36,000 mol. wt membranous protein is a prerequisite for the degranulation of RBL-2H3 cells.

Animals↗
PubMed1988

[Osteoporotic changes in rheumatoid arthritis--longitudinal bone mass study and effect of 1 alpha-hydroxyvitamin D3].

Serial measurements of bone mass were carried out by single photon absorptiometry and/or X-ray microdensitometry of the second metacarpus in 29 rheumatoid arthritis patients not treated by corticosteroids. The effect of 1 alpha-hydroxyvitamin D3 on rheumatoid arthritis was also investigated by longitudinal bone mass study. In premenopausal females and also males, the rate of radial diaphyseal bone loss was less than 1%/year and bone loss was seen only in the periarticular region of affected joints. On the other hand, bone loss was much more rapid in both the periarticular and diaphyseal regions in postmenopausal patients. 1 alpha-hydroxyvitamin D3 administration for more than 1 year produced no significant change of blood biochemical examination and Lansbury's index, but resulted in a significant attenuation of bone loss rate.

Absorptiometry, Photon↗
PubMed1987

Calcium influx in a single rat basophilic leukemia cell as revealed with a digital imaging fluorescence microscope.

Using a digital imaging fluorescence microscope, we have detected a rapid transient increase in the free cytosolic calcium concentration in a single rat basophilic leukemia cell (RBL-2H3) after antigen stimulation. Calcium ions were transported very rapidly (within 1 s) after a lag time (about 10 s at 37 degrees C) from the external environment into the cytoplasm. On the basis of the present experimental results we conclude that the gradual changes in the overall fluorescence intensity observed for a cell suspension are due to the distribution of different lag times shown by different cells as to the calcium influx through membrane calcium channels.

Animals↗
PubMed1987

[Osteoporotic changes in rheumatoid arthritis].

Bone mineral density (BMD) in the distal 1/6 and 1/3 sites of the radius was measured by single photon absorptiometry in 58 female patients with rheumatoid arthritis, not treated with corticosteroids. Half of the patients showed lower values of BMD than those (mean--1SD) of age-matched controls. BMD decreased more significantly with advancement of destructive changes of radiocarpal joint in postmenopausal patients. There was a significant inverse correlation between BMD and duration of the disease. Decreasing rate of BMD was much higher in postmenopausal patients than in premenopausal patients. These results indicated rheumatoid arthritis was not universally associated with osteoporosis. Osteoporosis occurred much more frequently in postmenopausal patients with a long duration of the disease showing marked joint destruction. In premenopausal patients, bone loss was most common in the region of affected joints. But, bone loss in postmenopausal patients occurred not only in the periarticular bone but in the diaphyseal bone.

Adolescent↗
PubMed1986

An immunological study of a Pb-thionein like protein in rat liver.

Administration of a sublethal dose of lead acetate to rats induced the simultaneous synthesis of a Pb-thionein like protein (Pb-BP) and Zn-thionein in the liver. To determine of the Pb-BP is a species of metallothionein, immunological properties of this protein were investigated. The results indicate that the Pb-BP is cross-reactive with the antibody against rat Zn-thionein II, strongly suggesting that the Pb-BP is a metallothionein.

Animals↗
PubMed1986

Simultaneous induction of Pb-metallothionein-like protein and Zn-thionein in the liver of rats given lead acetate.

Administration of a sublethal dose of lead acetate to rats induced the simultaneous synthesis of a Pb-metallothionein (Pb-MT)-like protein (Pb-BP) and Zn-thionein (Zn-BP) in the liver. The Pb-BP had an apparent molecule mass of 6900 Da and seemed to bind preferentially to lead in the liver cytosol. The Zn-BP was identified by comparison of the Mr, elution profiles from Sephadex G-75 and DEAE-Sephadex A-25 columns, and polyacrylamide-gel-electrophoretic mobility, with those of rat liver Zn-MT-II. The Pb-BP accumulated in the liver to a maximum 6 h after the intraperitoneal injection of lead acetate and accounted for about 60% of the lead in the liver cytosol at this stage. However, after that, it gradually decreased in the liver, until it was close to the basal amount 24 h after the induction. In contrast, the amount of Zn-MT increased gradually, reached a maximum 12 h after the administration of lead acetate and maintained a constant value until at least 24 h after the induction. Amino acid analysis of the Pb-BP indicated that it contained about 28% half-cysteine. These results strongly suggest that lead acetate induces the synthesis of Pb-MT as well as Zn-MT in rat liver.

Amino Acids↗
PubMed1986

Possible involvement of phosphorylation of a 36,000-dalton protein of rat basophilic leukemia (RBL-2H3) cell membranes in serotonin release.

Phosphorylation of a 36,000-dalton (36k-Da) protein of rat basophilic leukemia (RBL-2H3) cell membranes was investigated. This phosphoprotein has been suggested to be the beta-subunit protein of the immunogloblin E (IgE) receptor of RBL-2H3 cells [Teshima et al., Biochem. biophys. Res. Commun. 125, 867-874 (1984)]. Phospholipids such as phosphatidyl serine, phosphatidyl inositol and phosphatidyl ethanolamine, which are known to be activators of protein kinase C, enhanced the phosphorylation of the 36K-Da protein. In contrast, 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (H-7) which has been identified as a potent inhibitor of protein kinase C in vitro decreased incorporation of radioactive phosphate from [gamma-32P]ATP into this protein. These results indicate that the phosphorylation of the 36K-Da protein of RBL-2H3 cell membranes is catalyzed by protein kinase C. H-7 also inhibited the release of serotonin from RBL-2H3 cells stimulated with an antigen or calcium ionophore A23187 and 12-O-tetradecanoyl phorbol 13-acetate (TPA). Treatment of the antigen-stimulated cells with TPA caused a synergistic effect on the serotonin release. A similar effect was obtained by treatment of A23187-stimulated cells with TPA or 1-oleoyl-2-acetyl glycerol.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1985

Effects of various cytochalasins on the IgE-mediated serotonin release from rat basophilic leukemia cells.

The effects of cytochalasins on the antigen-induced serotonin release from rat basophilic leukemia cells were investigated. These drugs could be divided into four groups based on their effect on the release: (1) drugs which enhance the release, (2) drugs which enhance the release at a low dose (10(-7) and 10(-6) M) and inhibit it at a high dose (10(-5) and 10(-4) M), (3) drugs which show only inhibition, and (4) drugs which are inert or slightly stimulate the reaction. Cytochalasins B and D were included in group 1 and chaetoglobosins A, D and J were placed in group 2. Group 3 contained aspochalasins B, D and cytochalasin A, and group 4 included chaetoglobosins E and F. The structure and activity relationships of these drugs are also discussed.

Animals↗