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Biomedical subjects

Y Tamura

Publications and source records attributed to Y Tamura.

At least 685 records · Page 38Linked to original sources
PubMed1981

[Comparative studies of urinary electrolyte excretion, the renin-angiotensin-aldosterone system and plasma dopamine-beta-hydroxylase activity in patients with idiopathic edema and normal subjects during the menstrual cycle (author's transl)].

The changes of circumferential size of legs, urine output, the amount of urinary Na and K excretion, tubular rejection fraction of Na (TRF Na), urinary Na/K ratio, plasma renin activity (PRA), plasma aldosterone concentration (PAC), the amount of urinary aldosterone excretion (UAE) and plasma dopamine-beta-hydroxylase activity (DBH) were studied in 7 patients with idiopathic edema and 5 normal subjects from the recumbent to upright positions by a water loading test (oral ingestion of 1 L of water) in the follicular and luteal phase of the menstrual cycle. The increase in circumferential size of legs in the patients with idiopathic edema was greater than in normal subjects. The percent reduction in urine output, urinary Na excretion, TRF Na and urinary Na/K ratio (upright versus supine) in patients with idiopathic edema tended to be greater than that in normal subjects. However, these indices showed no significant differences between the follicular and luteal phase both in patients with idiopathic edema and normal subjects. PRA and PAC, on the subjects' being tilted to the upright position after water loading, were not significantly different between patients with idiopathic edema and normal subjects during the menstrual cycle, while increases in PAC and UAE were noted in patients with idiopathic edema in the upright position, especially in the follicular phase. Interestingly, plasma DBH activity in patients with idiopathic edema was significantly lower than that in normal subjects in both the follicular and luteal phases. These results indicate that posturally induced anti-diuresis and anti-natriuresis seems not to be related to the phase of the menstrual cycle, and abnormal mechanisms of the dopaminergic autonomic nervous system might exist in this disorder.

Adult↗
PubMed1981

Substance P-like immunoreactivity in plasma of psychotic patients and effects of neuroleptics and electroconvulsive therapy.

Radioimmunoassay of substance P (SP)-like reactivity, using N alpha-tyrosyl-SP, was performed in plasma of psychotic patients. Schizophrenic patients under neuroleptic medication over 1 year, and those patients with organic brain disease showed a significant increase in immunoreactivity. The immunoreactivity in unmedicated schizophrenic patients just before treatment and in depressed patients, both bipolar and major, did not differ significantly from that of controls. The immunoreactivity in unmedicated schizophrenics was followed after medication for a maximum of 5 months. The reactivity decreased in five cases, and increased in three cases. No definite pattern could be discerned between changes in the immunoreactivity, the type of medication administered, and the resultant response to the therapy. Chlorpromazine injection caused no definite acute effect on the plasma level of SP-like immunoreactivity for 120 minutes. Electroconvulsive therapy increased the plasma level of SP-like immunoreactivity for 90 minutes in a male schizophrenic patient.

Adolescent↗
PubMed1981

Influence of ACTH therapy on overnight sleep polygrams in infantile spasms.

Overnight sleep polygrams were recorded before and during therapy in nine patients with infantile spasms. Results showed that ACTH therapy increased the waking time and decreased rapid eye movement sleep. Thus it caused sleep disturbance in patients with infantile spasms. During ACTH therapy the number of rapid eye movements/min and the pulse rate decreased significantly. Body movements/min also decreased, but not significantly. These results suggest that ACTH therapy may inhibit functions of the central nervous system. The respiratory rate increased during ACTH and clonazepam therapy, probably in association with the decrease or the absence of seizures. These findings indicate the necessity for further studies on whether ACTH therapy is really of value in patients with infantile spasms, and show that if ACTH is given, the period of therapy should be as short as possible.

Adrenocorticotropic Hormone↗
PubMed1981

Nonsteroidal antiinflammatory agents. 2. Synthesis of 4',5-disubstituted 3-biphenylylacetic acids and their derivatives with antiinflammatory and analgesic activities.

A series of 5',5-disubstituted 3-biphenylylacetic acids (5a-n) and several alpha-methyl derivatives (5o-v) were prepared as analogues of a newly developed nonsteroidal antiinflammatory agent, 5'-chloro-5-methoxy-3-biphenylylacetic acid [1 (DKA-9), R = 4-C1Ph; R' = Me], and evaluated for antiinflammatory and analgesic activities using both carrageenan rat paw edema and AcOH writhing assays. Among them, 5-fluoro-3-biphenylylacetic acid (5m) showed the highest antiinflammatory activity, while 2-(3-biphenylyl)propionic acid (5o) showed the highest analgesic activity. However, they were less potent than 1 (R = 4-C1Ph; R' = Me) in these assays.

Analgesics↗
PubMed1981

erythro-5-[1-Hydroxy-2-(isopropylamino)butyl]-7-hydroxycarbostyril, a terbutaline-type derivative of the bronchodilator procaterol.

erythro-5-[1-Hydroxy-2-(isopropylamino)butyl]-7-hydroxycarbostyril (4), which is a terbutaline-type derivative of the bronchodilator procaterol, was synthesized by transfer of the 8-hydroxyl group of procaterol to the 7 position. Compound 4 showed less potent beta-adrenoceptor stimulant activities than procaterol or terbutaline in an in vitro test using guinea pig tracheal muscle and right atrium. In an in vivo assay on anesthetized dogs, compound 4 showed 42 times less bronchodilator activity and 87 times less effect on the heart rate than l-isoproterenol.

Animals↗
PubMed1981

Nonsteroidal antiinflammatory agents. 3. Synthesis of the positional isomers of 4'-chloro-5-methoxy-3-biphenylylacetic acid and their antiinflammatory and analgesic activities.

The positional isomers 3a-i of 4'-chloro-5-methoxy-3-biphenylylacetic acid [1 (DKA-9), R = 4-ClPh; R' = MeO] which is a newly developed nonsteroidal antiinflammatory agent, have been prepared and evaluated for antiinflammatory and analgesic activities using both the carrageenan-induced rat paw edema and AcOH writhing assays. The 3- and 4-biphenylylacetic acids 3a,d, which closely resemble 1 (R = 4-ClPh, R' = MeO) structurally, showed, by far, excellent activities compared with the other isomers in these assays. However, none of the compounds tested was more active than 1 (R = 4-ClPh; R' = MeO). In this series of compounds, structural requirements for good antiinflammatory activity seemed to be parallel to those for analgesic activity.

Animals↗
PubMed1981

Studies on cholesterol esterase in the rat adrenal.

We have investigated the characteristics and properties of cholesterol esterase (CEase) in the rat adrenal to clarify the mechanism of synthesis of free cholesterol from esterified cholesterol. CEase activity was estimated using substrate vesicles which were sonicated mixtures of cholesteryl oleate and phosphatidylcholine (PC). CEase showed two optima at around pH 4.5 and pH 8.25. The acid CEase was found mainly in the lysosomal fraction, and the alkaline CEase was found mainly in the microsomal fraction. Both acid and alkaline CEase activities were markedly enhanced by increasing the concentration of PC, but not by phospholipids. The activities were not increased by the addition of cAMP, ATP, and MgCl2, when the molar ratio of cholesteryl oleate to PC was 1:0.2, but were increased when the molar ratio was 1:2. Thus, it is suggested that free cholesterol for steroidogenesis may be supplied by two different organelles (lysosome and microsome), and that the composition of the substrate complex, such as the ratio of esterified cholesterol to phospholipids, may play a crucial role in the regulation of adrenal CEase. Increases in both acid and alkaline CEase activities were observed in adrenal homogenates prepared from hypophysectomized rats treated with an iv injection of ACTH when the molar ratio of cholesteryl oleate to PC used as a substrate vesicle was 1:0.2, but not when the ratio was 1:2. Therefore, the present observation indicate that activation of CEase by ACTH is dependent on the substrate state, especially that of the cholesterol ester droplet in vivo.

Adrenal Glands↗
PubMed1981

[Pharmacological study of mequitazine (LM-209) (II). Anti-allergic action (author's transl)].

The anti-allergic effect of Mequitazine (LM-209) which was found to have an anti-histaminic activity was investigated in guinea-pigs. The inhibitory activities of LM-209 on the Schultz-Dale reaction and ileum contraction by some mediators released from the sensitized guinea-pig lung were the same as those of clemastine fumarate (CL) but with 5 times the potency. LM-209 and CL, but these activities were less potent than in the case of disodium cromoglycate. The various anaphylactic reactions mediated by IgG in guinea-pigs were inhibited by LM-209, CL and chlorpheniramine maleate (CPM). The homologous PCA mediated IgE in rats was also inhibited by LM-209, CL and CPM, but the duration of the action with LM-209 was markedly longer. In experimentally-induced asthma, the decrease of respiratory rate and volume was significantly inhibited by LM-209, but was not affected by CL. Thus, LM-209 seems to inhibit the allergic reaction mainly by an antagonistic action on allergic mediators.

Anaphylaxis↗
PubMed1981

Fibrinolytic and plasmin inhibitor activities in patients with acute myocardial infarction.

Fibrinolytic activity and plasmin inhibitor activity were determined by Blue Dextran-fibrin method in patients with acute myocardial infarction. The normal values of fibrinolytic activity and plasmin inhibitor activity were 3.34 +/- 0.74 units and 10.10 +/- 2.39 units (mean +/- SD), respectively. The fibrinolytic activity in normal women (3.63 +/- 0.99 units) was slightly higher than that in normal men (3.17 +/- 0.79 units), but the plasmin inhibitor was not significantly different in the two sexes statistically. Neither activity varied significantly with age. The blood fibrinolytic activity was depressed in the first week after acute myocardial infarction, the decrease being maximal 3 to 4 days after the event (1.73 +/- 0.31 units). The mean plasmin inhibitor activity remained normal after acute myocardial infarction, but it was increased in 3, and decreased in 4 of 7 patients in whom it was measured 3 to 4 days after the event.

Adult↗
PubMed1981

Partial purification of pulmonary cytochrome P-448 from 3-methylcholanthrene-treated rats.

Pulmonary cytochrome P-448 from 3-methylcholanthrene-pretreated rats was partially purified approximately 20-fold. The purified preparations containing 1.74 nmol per mg protein were essentially free of NADH-cytochrome b5 reductase and NADPH-cytochrome c reductase, and included a small amount of cytochrome b5 spectrophotometrically. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the partially purified cytochrome P-448 gave one major band and several minor bands when stained with Coomassie blue. The major band on which the presence of peroxidase activity could be determined had the apparent molecular weight of 57,000. In the presence of NADPH-cytochrome c reductase, lipid and NADPH, the pulmonary cytochrome P-448 was active in hydroxylation of benzo-[a]pyrene, but catalyzed N-demethylation of benzphetamine in a slow rate.

Animals↗
PubMed1981

Inter-relationship of sympathetic nervous system and renin-angiotensin-aldosterone system in three renin subgroups of borderline and persistent essential hypertension.

Plasma renin activity (PRA), dopamine beta-hydroxylase (DBH) activity, and plasma aldosterone concentration were determined in 51 patients categorized as borderline or persistent hypertensives and as high, normal, or low renin. Basal DBH activity correlated with diastolic blood pressure in borderline but not in persistent hypertensives. In borderline patients with normal or high renin activity standing plus furosemide caused a marked rise in diastolic blood pressure but little change in systolic and increased PRA and DBA. In contrast this stimulation procedure depressed both systolic and diastolic blood pressure and resulted in blunted PRA and DBH responses in the low renin borderline and the three groups of persistent hypertensives. After dietary sodium restriction, the decrease in systolic blood pressure correlated with the decrease in urinary sodium excretion in persistent, but not in the borderline patients. The data suggest that both borderline an persistent hypertensive patients respond to volume depletion with an increase in sympathetic and renin activity, and the increase of these two vasoconstrictive systems is greater in borderline hypertensives.

Adult↗
PubMed1981

[Pharmacological study of mequitazine (LM-209) (III). Action on the central nervous system (author's transl)].

The action of an anti-histaminic agent, Mequitazine (LM-209) on the central nervous system was investigated. We found that LM-209 did not affect the spontaneous and co-operative movement in mice, did not induce muscle relaxation, analgesic effects or anti-convulsant effect in micr or hypothermic effects in rats. The anti-oxotremorine effect of LM-209 in mice was about 10 times more potent than clemastine fumarate (CL) and the same as promethazine. The activity and duration of the action were also superior to diethazine and orphenadrine used as an anti-Parkinson drug. LM-209 prolonged by 50% the hypnotic time induced by hexobarbital at 50 mg/kg (p.o.) in mice, while CL prolonged 50 and 100% it at 25 and 50 mg/kg (p.o.) respectively. In the EEG of rabbits, LM-209 produced a resting pattern, inhibited the arousal responses and recruiting responses and the effect was the same as CL and less potent than promethazine. From these results, the activity of LM-209 on the central nervous system (except for the anti-oxotremorine effect) seems to be the same as or somewhat less potent than CL. Therefore LM-209 should be an effective and anti-histaminic agent for clinical application.

Analgesics↗
PubMed1981

[Pharmacological study of mequitazine (LM-209) (I). Antagonistic actions of chemical mediators (author's transl)].

Antagonistic activities of Mequitazine (LM-209) on chemical mediators and in particular histamine were investigated in guinea-pigs, mice and rats. The antagonistic activity of LM-209 for histamine in the isolated ileum and trachea of guinea-pigs was less potent than that for clemastine fumarate (CL) and chlorpheniramine maleate (CPM) while that for acetylcholine was more potent than CL and CPM. Moreover, the antagonistic activities of these three compounds on serotonin and bradykinin were almost equipotent in the excised ileum. Using a modified Konzett-Rössler method, the bronchodilating effect of LM-209 (p.o.) for histamine was same as CL, but that for acetylcholine was more potent than CL and CPM. The protective activity of LM-209 (p.o.) on acute death induced by histamine and metacholine in mice was the same as CL, but the duration of the anti-histaminic action was markedly longer than CL. LM-209 given orally inhibited markedly the increased vascular permeability by histamine in rats and the diarrhea by 5-HTP in mice, but did not affect on the histamine-induced ulcer in guinea-pigs. From these results, LM-209 appears to have potent and long acting antagonistic activity on various chemical mediators.

Acetylcholine↗