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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 757 records · Page 42Linked to original sources
PubMed1983

Comparison of efficacy of timiperone, a new butyrophenone derivative, and clocapramine in schizophrenia: a multiclinic double-blind study.

The clinical efficacy and safety of timiperone, a new butyrophenone derivative, on chronic schizophrenia was compared with clocapramine by the double-blind method using a total of eighty-eight patients, consisting of forty-four patients in each group. In the final global improvement rating, the global improvement rating in each week and the general usefulness rating, there were no statistically significant differences between the two groups. However, in the global improvement rating in each symptom, timiperone was significantly superior to clocapramine in delusion and showed a superior tendency to clocapramine in contact. Timiperone showed a higher improvement rate than clocapramine in hallucination and disturbance of self-consciousness. In the over-all safety rating, there were no significant differences between the two groups, but in accompanying symptoms and side-effects, timiperone showed significantly less tendency than clocapramine in dyskinesia, insomnia, constipation and nausea. From these results, including the analysis by stratification, it was considered that timiperone was a superior or equivalent neuroleptic in comparison with clocapramine against the negative symptoms as well as the positive ones of chronic schizophrenia, and was equally safe or safer than clocapramine.

Adolescent↗
PubMed1983

[Effects of tricyclohexyltin hydroxide on carbohydrate and lipid metabolisms].

Male Japan white rabbits were given orally with two doses of tricyclohexyltin hydroxide (TCHT, 250 mg/kg body weight) at 48 hr intervals and their carbohydrate and lipid metabolisms were investigated 48 hr after the last administration. Elevated fasting blood glucose levels and a significant inhibition of insulin (IRI, immunoreactive insulin) release in response to the intravenous glucose infusion were observed. Microscopic examination of pancreatic islets did not reveal any histological alteration. Plasma triglyceride levels were elevated in the TCHT-treated rabbits. Ultracentrifugation of plasma lipoproteins revealed a marked increase in chylomicron + VLDL (very low density lipoprotein) fraction. Rates of triglyceride secretion into plasma were not different between the TCHT-treated and the control animals. These data suggest that TCHT induces hyperglycemia and hyperlipidemia in rabbits, and the disturbance of metabolism seems to be related to the inhibition of insulin release from the pancreatic islets by TCHT.

Animals↗
PubMed1983

[The effect of triphenyltin fluoride on aggregation, ATP secretion and malondialdehyde formation of rabbit platelets in vitro].

Recent studies have demonstrated that triphenyltin fluoride (TPTF), widely used as an agricultural chemical and a marine antifoulant, inhibits collagen-induced platelet aggregation and ATP secretion in rabbits ex vivo. The aim of the present investigation was to elucidate the mechanism of the inhibitory action of TPTF by investigating platelet malondialdehyde (MDA) formation, aggregation and ATP secretion following the stimulation by various stimuli of rabbit platelets treated in vitro with TPTF, other triphenyl metals and aspirin. Although no inhibitory effect of TPTF was found on sodium arachidonate-induced platelet aggregation and ATP secretion, TPTF inhibited dose-dependently both platelet aggregation and ATP secretion induced by collagen. The antiaggregating (IC50) concentration of TPTF was 6.0 X 10(-6) M against collagen. In addition, TPTF prevented the collagen-, and thrombin-induced formation of MDA, but had little inhibitory effect on the conversion of exogenous arachidonic acid to MDA in platelets. In contrast, aspirin (10(-3) M) inhibited platelet aggregation, ATP secretion and MDA formation induced by all the stimuli tested. Other triphenyl metals did not any inhibitory effect on collagen-, and sodium arachidonate-induced platelet aggregation and ATP secretion even at a final concentration at 10(-3) M. These results suggest that TPTF has a specific inhibitory effect on platelet aggregation and ATP secretion by acting at some step(s) of platelet membrane between the binding site of collagen and thrombin and the release of arachidonic acid.

Adenosine Triphosphate↗
PubMed1983

Modulation of optical density by sulfhydryl reagents in microbiuret method: a modified method for protein determination in the presence of sulfhydryl reagents.

2-Mercaptoethanol increases the optical density of assay solutions at wavelengths between 280 to 400 nm, and therefore interferes with the measurement of protein concentration by the microbiuret method. Protein concentration can be determined in the presence of 2-mercaptoethanol up to 6 mM by modification of the method as follows: after the precipitation of protein by trichloroacetic acid in the presence of deoxycholate, the precipitate is resolubilized with NaOH solution. Dithiothreitol interfered with the protein determinations could by made in the presence of 4 mM of dithiothreitol with the modified microbiuret method. This modified method is time-saving and more reliable than other methods for protein determination, such as Lowry's method, in the presence of sulfhydryl reagents.

Proteins↗
PubMed1983

Thigh and calf blood flows after isometric contraction in untrained and trained subjects.

The present study was undertaken to examine whether or not there were any differences between untrained and trained subjects in the changes of blood flow in the ipsilateral and contralateral lower limbs after isometric exercise. Blood flow of the thigh and calf in both right and left legs were measured simultaneously before and after isometric contraction with mercury-in-silastic strain gauge venous occlusion plethysmography. In the present study, the main pattern of blood flow responses in the active and non-active limbs was strikingly similar in all subjects: a significant fall in blood flow immediately after isometric contraction at a force of about 50% of maximal muscle strength for 15 sec was observed in the non-active lower limbs. Peak blood flow of the exercised thigh in the trained group was significantly higher than that in the untrained ones. From these results, it was suggested that higher blood flow after isometric exercise in the trained subjects may be due to the improvement of degree of vasodilation in the lower limb as a result of physical training.

Adult↗
PubMed1983

Natural killer (NK) cells as a responder to interleukin 2 (IL 2). II. IL 2-induced interferon gamma production.

In the accompanying paper, we showed that natural killer (NK) cells were a major population in the naive spleens of normal mice that responded directly to a T cell growth factor, interleukin 2 (IL 2), and clonally replicated without other stimulating agents. The cloned cells growing in IL 2 showed a potent NK activity against several NK targets without addition of an NK-activating agent, interferon (IFN). In the present study, therefore, we examined whether these cloned NK cells on their own produced IFN. It was found that all NK clones growing in IL 2 produced IFN in the culture fluids. The titers of IFN produced in the IL 2-containing media correlated well with the number of growing cells. With the culture in the absence of IL 2, neither cell growth nor IFN production could be detected. Addition of Con A into the culture in the IL 2-free media showed no IFN production. The antiserum neutralizing IFN alpha and IFN beta failed to significantly neutralize IFN produced by NK clones. Treatment with either a pH of 2.0 or antiserum neutralizing mouse IFN gamma resulted in a marked reduction of IL 2-induced NK IFN, indicating that a major part of IFN produced was IFN gamma. These results indicate that IL 2 stimulates NK clones to proliferate, accompanied by IFN gamma production. The results also show that an NK clone, when stimulated with Sendai virus, produced a type 1 IFN (IFN alpha and/or IFN beta), suggesting that murine NK cells can produce both type 1 (alpha and/or beta) and type 2 (gamma) IFN, depending on inducers.

Animals↗
PubMed1982

Black widow spider venom: excitatory action on hippocampal neurons.

Electrical activities of thin hippocampal sections of the guinea pig were studied in vitro during and after administration of black widow spider venom (BSV). In CA3 neurons, BSV induced spontaneous discharges which were suppressed by Co2+ or Mn2+. During BSV administration, trains of potential changes resembling excitatory postsynaptic potentials (EPSPs) were recorded intracellularly. The EPSP-like potentials were blocked by TTX. BSV seems to induce impulses in presynaptic fibers or terminals and thereby facilitates release of neurotransmitters.

Animals↗
PubMed1982

Endoscopic bipolar electrocoagulation: development of a new bipolar coagulator for stopping gastrointestinal bleeding.

We have developed an endoscopically deliverable bipolar coagulator with a pair of active bipolar electrodes and tested its efficacy and safety in canine gastric bleeding models. Hemostasis was achieved with a few applications in all "ulcer maker", gastric serosal vessel, mesenteric vessel and endoscopic "hot biopsy" models. Histologically the mean muscular injury was 10.1% in ulcer maker models and 17.1% in hot biopsy models, significantly less than monopolar electrodes. No full thickness injury resulted. Initial clinical trials in 32 patients with upper gastrointestinal bleeding revealed 100% immediate hemostasis; it could stop spurting arterial bleeding. Our bipolar coagulator is a promising addition to the endoscopic hemostatic methods.

Adolescent↗
PubMed1982

Effect of acute administration of cadmium on distribution of zinc in the hamster.

Acute administration of sc doses of Cd (1mg/kg . d, 3 or 6 d) to male golden hamsters resulted in a remarkable dose-dependent increase of Zn in the liver and kidney. In contrast, Zn contents in the heart and testes showed a significant dose-dependent decrease. No change was found in Zn contents of the bone. The correlation coefficients between contents of Cd and Zn in the liver and kidney were much higher in metallothionein fractions than in the corresponding whole organs. These results suggest that Cd induces the synthesis of metallothionein in the liver and kidney, leading to simultaneous accumulation of Cd and Zn in the organs; this in turn decreases the Zn contents in other organs, where weak or no induction of metallothionein synthesis takes place. Therefore Cd might induce Zn deficiency in humans or animals whose pool size and intake of Zn are marginal.

Animals↗
PubMed1982

Interaction of sodium and potassium ions with Na+,K+-ATPase. II. General properties of ouabain-sensitive K+ binding.

General properties of ouabain-sensitive K+ binding to purified Na+,K+-ATPase [EC 3.6.1.3] were studied by a centrifugation method with 42K+. 1) The affinity for K+ was constant at pH values higher than 6.4, and decreased at pH values lower than 6.4. 2) Mg2+ competitively inhibited the K+ binding. The dissociation constant (Kd) for Mg2+ of the enzyme was estimated to be about 1 mM, and the ratio of Kd for Mg2+ to Kd for K+ was 120 : 1. The order of inhibitory efficiency of divalent cations toward the K+ binding was Ba2+ congruent to Ca2+ greater than Zn2+ congruent to Mn2+ greater than Sr2+ greater than Co2+ greater than Ni2+ greater than Mg2+. 3) The order of displacement efficiency of monovalent cations toward the K+ binding in the presence or absence of Mg2+ was Tl+ greater than Rb+ greater than or equal to (K+) greater than NH4+ greater than or equal to Cs+ greater than Na+ greater than Li+. The inhibition patterns of Na+ and Li+ were different from those of other monovalent cations, which competitively inhibited the K+ binding. 4) The K+ binding was not influenced by different anions, such as Cl-, SO4(2-), NO3-, acetate, and glycylglycine, which were used for preparing imidazole buffers. 5) Gramicidin D and valinomycin did not affect the K+ binding, though the former (10 micrograms/ml) inhibited the Na+,K+-ATPase activity by about half. Among various inhibitors of the ATPase, 0.1 mM p-chloromercuribenzoate and 0.1 mM tri-n-butyltin chloride completely inhibited the K+ binding. Oligomycin (10 micrograms/ml) and 10 mM N-ethylmaleimide had no effect on the K+ binding. In the presence of Na+, however, oligomycin decreased the K+ binding by increasing the inhibitory effect of Na+, whether Mg2+ was present or not. 6) ATP, adenylylimido diphosphate and ADP each at 0.2 mM decreased the K+ binding to about one-fourth of the original level at 10 microM K+ without MgCl2 and at 60 microM K+ with 5 mM MgCl2. On the other hand, AMP, Pi, and p-nitrophenylphosphate each at 0.2 mM had little effect on the K+ binding.

Animals↗
PubMed1982

Characteristics and Activity Changes of Proteolytic Enzymes in Apple Leaves during Autumnal Senescence.

At least four different proteinases are present in senescing apple leaves (Malus domestica Borkh. cv. Golden Delicious) as determined by their pH optima, substrate specificity, and their reactivity to proteinase inhibitors. An enzyme active at pH 4.5 to 5.0 appears to be a sulfhydryl-dependent (iodoacetamide and phenylmercuric acetate-sensitive) endoproteinase, and degradation of the large subunit of ribulose bisphosphate carboxylase was observed only with this enzyme. It is tentatively concluded that this endoproteinase is responsible for the breakdown of ribulose bisphosphate carboxylase in vivo. However, the presence of more than one endoproteinase in apple leaves is suggested by the broad range of pH optima of the SH-dependent enzyme. Another enzyme active at pH 6.0 appears to be a carboxypeptidase, and was sensitive to phenylmethylsulfonylfluoride. This enzyme showed a strong hydrolytic activity against carbobenzoxyphenylalanylalanine. A sulfhydryl-dependent aminopeptidase and a second hydroxyl-dependent carboxypeptidase were active at pH 7.5Total autolytic activity (the sulfhydryl-dependent endoproteinase) as measured by the disappearance of proteins decreased during the period of protein decline. Evidence is presented that the measured proteinase activity can be dependent on assay methods and substrates. While the disappearance of protein measures most of endo-type activity, the ninhydrin assay appears to measure exo-type activity preferentially.

Journal Article↗