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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 739 records · Page 41Linked to original sources
PubMed1984

Neuronal sensitivity to opiate and opioid peptides in the bed nucleus of the stria terminalis. Effects of chronic treatment with morphine.

To characterize the phenomenon of morphine tolerance in central nervous system, the neuronal sensitivity to opiate and opioid peptides in the bed nucleus of the stria terminalis (BST) and the effects of chronic treatment with morphine were examined with thin slices of the brain of guinea pigs. Both morphine and enkephalins (D-Ala2-Met5-enkephalinamide and D-Ala2-D-Leu5-enkephalin) suppressed neuronal activity in the stria terminalis. Three days after implantation of morphine pellets the guinea pigs became tolerant to morphine and EC50 (the morphine concentration required for causing 50% of the maximal effect) was 79 microM, nearly six times the value in the control animals (EC50 = 13 microM). Cross-tolerance between morphine and enkephalins was not observed. Results of radioreceptor assay, using [3H]dihydromorphine as a ligand, showed that the binding capacity of the morphine-tolerant animals was not statistically different from that of the controls. These results suggested that tolerance to morphine cannot be explained by changes in number and/or affinity of opiate receptors, and that tolerance probably results from modification of the intracellular mechanisms mediating between the binding of morphine with the receptors and neuronal inhibition.

Amygdala↗
PubMed1984

Endoscopic bipolar electrocoagulation in upper gastrointestinal bleeding.

A new endoscopically deliverable bipolar electrocoagulator has been developed, and employed clinically to treat upper gastrointestinal bleeding in 53 patients on 61 occasions. By direct application of the electrode to the bleeding vessels immediate hemostasis was achieved in 52 out of 53 bleeding vessels. Non-bleeding visible vessels were safely coagulated. Arrest of bleeding was permanent in 44 patients (83%), of whom 20 were candidates for emergency operation because of massive, continued or recurrent bleeding. Rebleeding after hemostasis by bipolar electrocoagulation was noted in 8 patients (15%); however, the majority of rebleeds were those with acute mucosal lesions who had serious underlying medical problems. Emergency operation was performed in 5 patients, and was averted in most patients after successful hemostasis by bipolar electrocoagulation. There were no complications related to the procedure. Bipolar electrocoagulation with our coagulator is a safe and easily applicable technique that is a promising addition to currently available endoscopic hemostatic methods.

Adolescent↗
PubMed1984

Kinetic studies on the substrate specificity and active site of rabbit muscle acid alpha-glucosidase.

Mammalian muscle acid alpha-glucosidase was highly purified for the first time from rabbit muscle by fractionation with ammonium sulfate, and chromatographies on Sephadex G-100, CM-TOYOPEARL and TOYOPEARL HW-55. The resulting preparation showed a single band on polyacrylamide disc gel electrophoresis. The molecular weight was estimated to be 1.02 X 10(5) by SDS-electrophoresis. The optimum pH was found to be 4.5. The alpha-glucosidase showed relatively high activity not only toward maltose but also toward alpha-glucans, such as soluble starch, beta-limit dextrin, amylopectin, shellfish glycogen, and amylose. The Km values for maltose and glycogen were 6.3 mM and 12 mM (the concentration of non-reducing glucose units), respectively, and the ratio of the maximum velocities of hydrolyses of the two substrates was 100:66.7, in that order. Rabbit muscle acid alpha-glucosidase showed a wide specificity for various substrates. The Km values for maltose, maltotriose, -tetraose, -pentaose, -hexaose, -heptaose, and -octaose, and maltodextrins of average polymerization degrees of 13 and 17 were 6.3 mM, 2.6 mM, 5.9 mM, 3.0 mM, 5.9 mM, 5.9 mM, 5.9 mM, 7.7 mM, and 5.6 mM, respectively. The relative maximum velocities for maltooligosaccharides consisting of three or more glucose units were 43.5-89.3% of that for maltose. For disaccharides, the rate of hydrolysis decreased in the following order: maltose divided by nigerose greater than kojibiose greater than isomaltose. The purified enzyme was a typical acid alpha-glucosidase of mammalian origin, which hydrolyzed various substrates to produce alpha-glucose. The nature of the active site catalyzing the hydrolyses of maltose and glycogen was investigated by some kinetic methods. In experiments with mixed substrates, maltose and shellfish glycogen, the kinetic features agreed very closely with those theoretically predicted for a single site mechanism. The essential ionizable groups, 1 (on the acidic side) and 2 (on the alkaline side), were identified as -COO- and -COOH for the hydrolysis of both substrates. Cations, Na+, K+, and Mg2+, were about equally effective for stimulation of the enzyme actions on maltose and shellfish glycogen. Tris, turanose and erythritol inhibited not only maltase activity but also glucoamylase activity of the enzyme. From these results, it was concluded that rabbit muscle acid alpha-glucosidase attacks maltose and glycogen by a single active site mechanism.

Animals↗
PubMed1984

Pharmacokinetics of cefpiramide (SM-1652) in humans.

The pharmacokinetics of cefpiramide (SM-1652) were studied after the intravenous administration of single or multiple doses to 21 healthy volunteers. The cefpiramide concentration in plasma at time zero after a bolus intravenous injection of 500 or 1,000 mg was 152 or 303 micrograms/ml, respectively. The maximum cefpiramide level in plasma at the end of a 1-h infusion of 1,000 or 2,000 mg was 166 or 317 micrograms/ml, respectively. The mean plasma half-life of cefpiramide in 15 subjects who received a single dose of 500 or 1,000 mg was 4.44 h. There was no evidence of drug accumulation in plasma when 500 or 1,000 mg of cefpiramide was administered 11 times at 12-h intervals. Urinary excretion of cefpiramide over a 24-h period was ca. 22.5%, regardless of the intravenous administration technique and the dosage. Fecal recoveries of cefpiramide varied from 0 to 36.9% in different subjects.

Adult↗
PubMed1984

Comparative pharmacokinetics of YM-13115, ceftriaxone, and ceftazidime in rats, dogs, and rhesus monkeys.

The pharmacokinetics of YM-13115, ceftriaxone, and ceftazidime were studied in rats, dogs, and rhesus monkeys (only YM-13115 and ceftriaxone were studied in rhesus monkeys). The plasma half-lives in rats were 48 min for YM-13115, 34 min for ceftriaxone, and 14 min for ceftazidime. In dogs, they were 21.9 min for YM-13115, 50.7 min for ceftriaxone, and 49.0 min for ceftazidime. In monkeys, they were 5.30 h for YM-13115 and 3.40 h for ceftriaxone. The 24-h urinary recoveries in rats were 26.7% of the dose for YM-13115, 32.0% for ceftriaxone, and 97.1% for ceftazidime. In dogs, they were 13.3% for YM-13115, 62.5% for ceftriaxone, and 86.3% for ceftazidime. In monkeys, they were 22.5% for YM-13115 and 29.3% for ceftriaxone. The 24-h biliary recoveries in rats were 72.2% for YM-13115, 61.8% for ceftriaxone, and 0.63% for ceftazidime.

Animals↗
PubMed1984

Adrenal medullary secretion in response to diencephalic stimulation in the rat.

The effect of diencephalic stimulation on adrenal medullary secretion was investigated in pentobarbital-anesthetized rats. Adrenal secretions of epinephrine and norepinephrine were evaluated by collection and fluorometric analyses of adrenal venous blood samples. A significant increase in epinephrine secretion was produced by stimulation of the dorsomedial, ventromedial and lateral hypothalamic areas and the posterior regions of the thalamus. Most of the positive responsive areas in the diencephalon were localized near the dorsomedial hypothalamic nucleus. In contrast, a significant decrease in epinephrine secretion with or without a significant decrease in norepinephrine secretion was observed following stimulation of the preoptic area and lateral hypothalamic region and a significant decrease in norepinephrine secretion following stimulation of the anterior region of the thalamus. These findings may be interpreted as indicative of existences in the diencephalon of excitatory and inhibitory central nervous system mechanisms for the control of the adrenal medullary secretion.

Adrenal Medulla↗
PubMed1984

Cell-cycle-dependent changes of the negative surface charges in L929 cells.

The negative charges of cell surface were studied by the adsorption method of methylene blue in the synchronized cultures of L929 cells and its spontaneously transformed cell strain. The negative surface charges of the transformed cells were twice those of the original cells through all cell cycle phases. The surface charges cell-cycle-dependently changed in both cell systems and there were two maximum peaks at early G1 and S phase.

Animals↗
PubMed1984

[Effect of triphenyltin chloride on superoxide (O2-.) production in human neutrophils].

Brief treatment (3 min at 37 degrees C) of human neutrophils with triphenyltin chloride (TPTC1) resulted in a dose-dependent inhibition of superoxide (O2-.) production stimulated by concanavalin A+ cytochalasin D. It was considered from the following findings that the inhibition may be caused by some functional disorders of neutrophils: 1) O2-. generated by xanthine oxidase-acetaldehyde system was not inhibited by TPTC1. 2) There was no change in cell viability after treatment with TPTC1. When the other phenyltin compounds were examined, the relative potencies of inhibitory effect were shown to be in the order of TPTC1 greater than diphenyltin dichloride greater than phenyltin trichloride greater than tetraphenyltin on a molar basis. Lysosomal enzyme release caused by neutrophils stimulated by N-formyl-methionyl-leucyl-phenylalanine (FMLP) was also inhibited by TPTC1. These results suggest that TPTC1 inhibits the common pathway(s) of the two stimulus responses.

Glucuronidase↗
PubMed1984

Interaction of neuroleptics and antidepressants with rat brain alpha 2-receptors: a possible relationship between alpha 2-receptor antagonism and antidepressant action.

The relative potencies of a variety of neuroleptic drugs and antidepressant agents in competing for the binding of 3H-clonidine and 3H-yohimbine to alpha 2-adrenergic receptors of the rat cerebral cortex were quantified. The rank order of potencies of neuroleptics tested in competing for both ligand bindings is: clocapramine, carpipramine much greater than perphenazine, fluphenazine, alpha,beta-flupentixol greater than propericiazine, levomepromazine greater than chlorpromazine, pimozide greater than moperone much greater than haloperidol, sulpiride. Among the antidepressants, mianserin is the most potent antidepressant. Amitriptyline has a substantial affinity, while desipramine, imipramine, and clomipramine are the least potent. It is concluded that a number of neuroleptics and antidepressant agents display a potent or moderate affinity to alpha 2-receptor sites. These findings support the suggestion that some neuroleptics enhance the release of norepinephrine (NE) mainly by acting on presynaptic alpha 2-receptors, and that the alpha 2-receptor blocking property may have an important role in the mechanism of the antidepressant effect of some neuroleptic compounds.

Animals↗
PubMed1983

Triphenyltin chloride inhibits superoxide production by human neutrophils stimulated with a surface active agent.

Treatment of human neutrophils with triphenyltin chloride (TPTCl)-inhibited superoxide (O-2) production stimulated with phorbol myristate acetate (PMA). TPTCl was more potent as inhibitor of O-2 production than other phenyltin compounds. The O-2 production by the xanthine oxidase-acetaldehyde system was not inhibited by TPTCl. This finding indicates that TPTCl does not itself react with O-2. Furthermore, TPTCl did not influence the isolated NADPH oxidase at all, though O-2 production of neutrophils stimulated with PMA in the presence of TPTCl was inhibited. These results indicate that TPTCl inhibits the activation process of the O-2 generating system.

Adult↗
PubMed1983

Molecular weights of alpha beta-protomeric and oligomeric units of soluble (Na+, K+)-ATPase determined by low-angle laser light scattering after high-performance gel chromatography.

The (Na+, K+)-ATPase of canine renal outer medulla was solubilized with a nonionic surfactant, octaethylene glycol n-dodecyl ether (C12E8), in the presence of 0.2 M sodium ion. The solubilized ATPase retained 74% of the enzymatic activity expressed before solubilization. Molecular species of the solubilized ATPase were analyzed by high-performance chromatography through a TSK-GEL G3000SW column in the presence of 1 mg/ml C12E8 at 23 degrees C. The eluate was monitored by one or two monitors chosen from the following: an ultraviolet absorption monitor, a precision differential refractometer and a low-angle laser light scattering photometer. The three kinds of elution pattern thus obtained can best be interpreted by assuming the presence of at least four kinds of protein component with molecular weights 1 740 000 +/- 230 000, 836 000 +/- 82 000, 286 000 +/- 30 000 and 123 000 +/- 8 000, respectively. Among them, those with the last two molecular weight were the major components. The amounts of the first three components were found to increase with time during the incubation before application to the column at the expense of that of the last one. The amounts of the last two were 18 and 73%, respectively, when measured immediately after the solubilization. A stoichiometric composition of 1:1 molar ratio for the alpha and beta polypeptide chains was obtained for the two major components as well as for the intact ATPase by high-performance gel chromatography in the presence of sodium dodecyl sulfate using the same column as above. The (Na+, K+)-ATPase was, thus, indicated to be solubilized with C12E8 to give the alpha beta-protomer and its dimer as the main components.

Animals↗
PubMed1983

Triphenyltin fluoride in vitro inhibition of rabbit platelet collagen-induced aggregation and ATP secretion and blockade of arachidonic acid mobilization from membrane phospholipids.

Recent studies have demonstrated that triphenyltin fluoride (TPTF) inhibits collagen-induced aggregation and ATP secretion of rabbit platelets in vivo [S. Manabe and O. Wada, J. Toxic. Sci. 6, 236 (1981)]. The aim of the present investigation was to test the effects in vitro of TPTF on platelet aggregation and to elucidate the mechanism of the inhibitory action by studying the release and metabolism of arachidonic acid and the cyclic AMP contents of rabbit platelets treated in vitro with TPTF. Although no inhibitory effect of TPTF was found on sodium arachidonate-induced platelet aggregation and ATP secretion, TPTF inhibited both reactions induced by collagen. Triphenylarsine and triphenylantimony did not inhibit, even at a concentration of 10(-3) M. The anti-aggregating concentration (IC50) of TPTF was 6.0 x 10(-6) M against collagen. TPTF had no inhibitory effect on the conversion of exogenous arachidonic acid to malondialdehyde (MDA) by platelets, while the collagen-induced production of arachidonate metabolites [MDA, 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and thromboxane B2] was remarkably inhibited by TPTF. Furthermore, TPTF apparently inhibited the collagen-induced release of arachidonic acid from platelets, although the formation of phosphatidic acid was not inhibited. Total cyclic AMP content after TPTF exposure was not changed significantly. These results indicate that TPTF inhibited the collagen-induced arachidonic acid release from platelet phospholipids, presumably by acting on phospholipase A2. Furthermore, it seems unlikely that the inhibition of arachidonic acid release by TPTF can be explained by the level of cyclic AMP in platelets.

Adenosine Triphosphate↗
PubMed1983

Inhibition of oxidative metabolism in rabbit polymorphonuclear leukocytes by triphenyltin chloride.

Treatment of rabbit polymorphonuclear leukocytes (PMN) with triphenyltin chloride (TPTCl) inhibited chemiluminescence generation stimulated by particulate stimulus, zymosan, or soluble stimuli, concanavalin A + cytochalasin D. Superoxide anion (O-2) production was also inhibited, indicating that the inhibition involved inhibition of early oxidative metabolic process(es). The direct inhibition of the activation process of the oxidative burst was established by the experiments showing that a) chemiluminescence generated by xanthine oxidase-acetaldehyde system was not inhibited by TPTCl, b) washing the PMN after the treatment with TPTCl did not affect the results of chemiluminescence, and c) there was no change in cell viability after the treatment with TPTCl.

Animals↗
PubMed1983

Structure of the human interleukin 2 gene.

We have cloned two species of EcoRI-cleaved DNA segments that together cover the entire sequence for the human interleukin 2 gene and have determined the nucleotide sequence of the gene and its flanking regions. The gene contains three introns and the exon sequences can be aligned with the previously reported cDNA sequence almost perfectly except for a few nucleotides in the 3' nontranslated region. The promoter region contains a prototype "TATA" sequence as well as a notable palindromic sequence. Particularly interesting is the presence of sequences in this region that are homologous to the promoter region of the human interferon-gamma gene. In addition, a sequence that closely resembles the core sequence for the viral enhancer elements has been found in the second intron. Such sequences may play a role in the expression of the interleukin 2 gene in lectin- or antigen-stimulated T lymphocytes.

Amino Acid Sequence↗
PubMed1983

Metabolic fate of [14C]SM-1652, a new antipseudomonal cephalosporin, after parenteral administration to rats.

A study of the metabolic fate of [14C]SM-1652 after intravenous or intramuscular injection into rats showed that: (i) the elimination of the labeled compound from the blood was the same after intravenous and intramuscular injections; (ii) the radiolabeled drug was distributed rapidly and widely after intravenous administration with the highest concentration in the kidney and the lowest in the brain; (iii) placental transmission was slight, as it was passed into the milk, where the concentration was about 14% that of plasma; (iv) 33 and 67% of the administered radioactivity was excreted in urine and feces, respectively; (v) radioactivity in both urine and bile was ascribable to unaltered SM-1652; and (vi) upon repeated intramuscular injections twice daily, levels of labeled SM-1652 in tissue increased gradually, reaching a plateau at the 11th injection.

Animals↗