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Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 235 records · Page 13Linked to original sources

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↗

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↗

Trace element content in two species of whale tapeworms, Diphyllobothrium macroovatum and Diplogonoporus balaenopterae.

Trace elements in two species of whale tapeworms, Diphyllobothrium macroovatum and Diplogonoporus balaenopterae, were analysed by atomic absorption spectroscopy. Six elements (Fe, Cu, Zn, Mn, Cd, Ca) were assayed from different regions of two tapeworms: scolex, neck, immature, mature and gravid proglottids. Whole strobilae at different stages of maturity were also examined. The relationship between the trace element content and the physiological significance is discussed.

Animals↗

Mechanism of protection by zinc against mercuric chloride toxicity in rats: effects of zinc and mercury on glutathionine metabolism.

To investigate the mechanism by which zinc suppresses mercury toxicity, the effects of zinc and mercury on glutathione (GSH) metabolism in the rat kidney were studied. When the time course of GSH level in the rat kidney was examined at 2, 6, and 12 h after treatment of rats with both metals, an increase of GSH was found and was apparently related to the activation of some GSH-associated enzymes. In the kidney of rats treated with both metals, the response of the protective function involving GSH and GSH-associated enzymes depended on the magnitude of mercury toxicity but appeared to be independent of the zinc dosage. The administration of diethyl maleate (DEM), which depletes GSH, increased lipid peroxidation and mercury toxicity concomitantly with a decrease of GSH level in the kidney of rats treated with zinc and mercury. In conclusion, the data suggest that an increased GSH level in the kidney resulting from the activation of GSH-associated enzymes plays a role in the protective effect of zinc against mercury toxicity.

Animals↗

Enhanced vasopressin release upon activation of the central neural mechanism in spontaneously hypertensive rats.

Monopolar electrical stimulation of the intermediate portion of the solitary nucleus in spontaneously hypertensive rats (SHRs) with cervical cordotomy and vagotomy resulted in a 1.68 times greater increase in plasma vasopressin concentration than in Wistar rats. The result implies that such an enhanced function of the central neural mechanism to release vasopressin in SHR backs up the functionally aberrant cardiovascular receptors.

Animals↗

Demonstration of intratumoral infiltration of tumor-specific Lyt-1+2- T cells mediating delayed-type hypersensitivity response and in vivo protective immunity.

The present study demonstrates the intratumoral infiltration of lymphocytes mediating anti-tumor delayed-type-hypersensitivity (DTH) responses as well as in vivo protective immunity. The surface phenotype and tumor specificity of these effector lymphocytes were determined. X5563 tumor-infiltrating lymphoid cells were obtained from the tumor mass of syngeneic C3H/HeN mice 2 weeks after the intradermal inoculation of 10(6) viable X5563 tumor cells. These lymphoid cells consisted of Thy-1-positive (29-35%), surface immunoglobulin-positive (16-29%), large granule-positive (15-25%) and esterase-staining-positive (10-20%) cells. They were tested for anti-X5563 DTH responses by utilizing a local adoptive transfer system and for tumor-neutralizing activity in a Winn assay. The results indicate that X5563 tumor-infiltrating lymphoid cells exhibited appreciable anti-X5563 DTH responses and conveyed complete protection against the tumor. Treatment of these lymphoid cells with anti-Thy-1.2 or anti-Lyt antibodies plus complement revealed that the in vivo anti-tumor immune responses were mediated predominantly by a Lyt-1+2- T cell subset. Such Lyt-1+2- T cell-mediated immunity was tumor-specific, since X5563-infiltrating and syngeneic MH134 hepatoma-infiltrating cells exhibited DTH response and tumor-neutralizing activity selectively against the respective tumor cell types. Thus, these results indicate that tumor-specific in vivo-protective Lyt-1+2- T cells infiltrate into the tumor mass. The results are discussed in the context of 1) the interrelation of DTH responses and the tumor protection mediated by the Lyt-1+2- T cell subset and 2) possible cellular interactions between Lyt-1+2- T cells and co-existing nonspecific tumoricidal effector cells such as macrophages.

Animals↗