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Biomedical subjects

H Kohda

Publications and source records attributed to H Kohda.

At least 91 records · Page 5Linked to original sources
PubMed1988

Potentiation of lethality and increase in body temperature by combined use of d-methamphetamine and morphine in mice.

Lethality and change in body temperature in mice were examined after subcutaneous injection of d-methamphetamine and morphine alone or in combination. The LD50 values for methamphetamine and morphine were calculated to be 95 and 670 mg/kg body wt., respectively. When a non-lethal dose of morphine (300 mg/kg) was administered with various doses of methamphetamine, the LD50 for methamphetamine was reduced to 5 mg/kg, indicating a marked potentiation of toxicity by combined use of both drugs. Injection of 5 mg/kg of methamphetamine produced slight hyperthermia, while 300 mg/kg of morphine decreased the body temperature of mice. However, when both drugs were used concomitantly, a marked increase in body temperature was observed. Hyperthermia was also observed when the dose of morphine was reduced to 50 mg/kg. It is postulated that hyperthermia is probably one of the contributory factors in the potentiated toxicity by combined use of morphine and methamphetamine.

Animals↗
PubMed1988

The inhibitory effect of methanol on forskolin-activated adenylate cyclase in rat erythrocyte membranes dependent on the state of the guanine nucleotide-binding stimulatory and regulatory protein.

Forskolin-activated adenylate cyclase activity in rat erythrocyte membranes was markedly inhibited by methanol in a concentration dependent manner. On the contrary, no change was observed in the basal cyclase activity in the presence of methanol. The methanol inhibition forskolin-activated cyclase activity was protected by the stimulation of Gs in the presence of NaF in a concentration dependent manner. These data indicate that low- and high-affinity binding sites of forskolin in rat erythrocyte membranes have different sensitivities to methanol.

Adenylyl Cyclase Inhibitors↗
PubMed1986

Construction of rat-mouse T cell hybridomas that express regulatable rat interleukin 2 receptor.

Spleen cells obtained from Lewis rats were cultured with 4 micrograms/ml Con A for 96 hr, and activated cells were fused with BW5147 mouse T lymphoma cells. Seven clones obtained by fusion expressed rat IL 2R. The expression of rat IL 2R on those hybrid cells could be up-regulated by IL 2 itself, ATL-derived factor, and TPA and CA++ ionophore. Those IL 2R could be down-regulated by murine MoAb ART-18 that detects rat IL 2R. All hybrid clones produced IL 2 constitutively. IL 2 produced by hybrid cells bound to its receptor and promoted the proliferation of hybrid cells in some clones. Incubation of cells with exogenous IL 2 resulted in the proliferation of hybrid cells, whereas the proliferation of some clones was inhibited by exogenous IL 2, indicating that IL 2 had bifunctional properties on cell growth. Rat IL 2R from 6H2-F9 hybrid cells was studied by both one- and two-dimensional SDS-PAGE with ART-18. The IL 2R derived from 6H2-F9 cells had 72,000 to 77,000 and 40,000 to 48,000 m.w. major components under nonreducing conditions, and had 50,000 to 56,000 m.w. major and 35,000 to 38,000 m.w. minor components under reducing conditions. The 110,000 m.w. component, the third component of IL 2R, was constantly observed in 6H2-F9 hybrid cells.

Animals↗
PubMed1986

5C6-F4, a novel 100,000-dalton rat lymphocyte activation antigen defined by monoclonal antibody.

Con A-activated rat thymocytes were used to immunize mice, and immune spleen cells were fused with NS/1 myeloma cells. One clone, designated 5C6-F4, reacted strongly with Con A-activated rat thymocytes and some LPS-activated rat spleen cells but not with normal thymocytes, spleen cells, or bone marrow cells of rat origin. The 5C6-F4 did not react with Con A-activated thymocytes of mouse origin. Immunoprecipitation of 5C6-F4 antigen from surface-iodinated Con A-activated rat thymocytes or LPS-activated rat spleen cells revealed its m.w. to be approximately 100,000. The kinetic studies of the expression of 5C6-F4 antigen revealed that 5C6-F4 antigen was detectable at 6 hr after Con A stimulation of rat spleen cells, whereas IL 2 receptor (IL 2R) was detectable at 12 hr. The appearance of 5C6-F4 antigen and IL 2R precede the onset of DNA synthesis of Con A-activated spleen cells. Thus, 5C6-F4 antigen is classified as early activation antigen. The 5C6-F4 inhibits the lymphocyte proliferation induced by mitogen and the IL 2-driven rat T cell proliferation. Sequential immunoprecipitation study as well as binding inhibition study indicated that the 5C6-F4 antigen is distinct from IL 2R molecule. The 5C6-F4 antigen appears to be a novel rat lymphocyte activation antigen that exhibits immunoregulatory function and also may serve as a useful marker of T cell activation.

Animals↗
PubMed1986

Decrease in d-methamphetamine sensitivity in mice due to ethanol: apparent inhibitory and stimulatory effects of ethanol on d-methamphetamine-induced locomotor activity.

The locomotor activity of mice was recorded after administration of d-methamphetamine-HCl (1.5, 2.5, 5.0 and 7.5 mg/kg body weight) and/or ethanol (0.8 and 1.6 g/kg body weight). Mice injected with lower doses of d-methamphetamine (1.5 or 2.5 mg/kg) showed a marked increase in locomotor activity, while in those with higher doses of d-methamphetamine (5.0 or 7.5 mg/kg), locomotor activity was not further enhanced, but slightly decreased. Administration of ethanol inhibited the stimulated locomotor activity caused by low doses of d-methamphetamine (1.5 or 2.5 mg/kg), while the stimulation of motility after higher doses of d-methamphetamine (5.0 or 7.5 mg/kg) was potentiated by administering ethanol. Although apparent inhibition and stimulation of d-methamphetamine-induced locomotor activity of mice due to ethanol was observed, it is suggested that mice administered ethanol showed the decreased sensitivity to d-methamphetamine by plotting total locomotor activity of mice against doses of d-methamphetamine administered. The half maximum effective dose of d-methamphetamine for locomotor activity was increased from 1.5 mg/kg to 3.0 mg/kg by concomitant administration of 1.6 g/kg ethanol.

Animals↗
PubMed1986

Steatocystoma multiplex. A facial papular variant.

A 32-year-old man had multiple asymptomatic, yellowish to normal skin-colored, moderately firm papules that were disseminated on the forehead, temple, and periauricular region. The histologic, enzyme histochemical, and ultrastructural findings were those of steatocystoma multiplex.

Adult↗