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Biomedical subjects

M Murayama

Publications and source records attributed to M Murayama.

At least 271 records · Page 15Linked to original sources
PubMed1981

Postural changes of vectorcardiogram in defect of the left pericardium.

Effects of postural changes upon the vectorcardiograms (VCGs) of four cases with a defect of the left pericardium (three complete and one partial) were compared to those of 115 control cases. Changes in the direction of a given instantaneous vector brought about by postural changes were significantly larger in cases with a pericardial defect than in controls. By turning to the left lateral position, the magnitude of the maximum leftward force decreased in all cases with complete defect, and increased in the case with partial defect and in 96% of controls. These findings were considered to reflect the increased mobility of the heart in cases with pericardial defect due to the lack of the restraining function of the pericardium.

Adolescent↗
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

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

Characteristics of body surface mapping in the aged.

1) Body surface mapping was performed in 15 patients with ischemic heart disease and 5 control subjects before and after isoproterenol infusion. In ischemic heart disease, ST map developed negative areas in the left anterior chest wall extending from mid line to left axillar line after isoproterenol. This distribution on ST depression was different from that of left ventricular hypertrophy or complete left bundle branch block which spared mid anterior chest. The point of maximal ST depression corresponded to one of the conventional chest lead in 6 of 15 cases. In other 9 cases, the point of maximal ST depression was mostly located superiorly to V3-V5. epsilon ST depression correlated well with the maximal ST depression (r = 0.90) but not very well with ST depression at V5 (r = 0.70). On 201 T1 stress scan, a reversible large perfusion defect was detected in 2 out of 5 patients with marked ST depression. These findings suggested that isoproterenol induced ST map changes are useful in diagnosis of myocardial ischemia. 2) Body surface map was obtained in 16 cases with chronic pulmonary disease. The location of the maximum R and initial R was relatively inferior to that of normal controls. Relatively deep S waves were frequently observed. Pulmonary function tests correlated with the maximum R voltage but not with the deepest S. Cases with relatively high pulmonary conus voltage were proved to have right ventricular hypertrophy on 201 T1 myocardial scintigraphy or on echocardiography.

Aged↗
PubMed1981

An experimental model of giant negative T wave associated with QT prolongation produced by combined effect of calcium and isoproterenol.

Changes of the surface ECG and monophasic action potential induced by isoproterenol injection were investigated under normo- and hypercalcemic conditions in dogs. (1) Biphasic time course of T wave changes, initially inverted and subsequently uprightly tall, was observed after intravenous injection of isoproterenol in doses of more than 2 microgram. (2) Initial prolongation and subsequent shortening of the phase 2 of action potential were observed on the ventricular surface in accordance with the biphasic time course of the T wave changes on the surface ECG after isoproterenol injection. (3) Giant T wave inversion associated with QT prolongation was obtained by isoproterenol injection under hypercalcemia. (4) Marked prolongation of total duration as well as phase 2 of action potential was observed in accordance with the giant negative T wave on the surface ECG. Although the mechanism of this experimental model of giant negative T wave is not clear, this model could have important suggestions on the unknown mechanism of giant negative T wave observed in various clinical status.

Action Potentials↗
PubMed1980

Nocturnal angina pectoris. Comparison between angina with ST segment elevation and depression documented by continuous orthogonal ECG recording.

In 30 patients with nocturnal angina, the night-time ECGs were continuously recorded, and the time and duration of attack, cyclic character of attacks, the relation of chest pain to ischemic ECG changes and arrhythmias during attack were compared between 18 cases with ST elevation and 12 cases with ST depression during attack. In cases with ST elevation, 1) attacks occurred between 2:00 and 8:00 a.m., being most frequent between 4:00 and 5:00 a.m. 2) the duration of attack measured from the duration of ischemic ECG changes was less than 5 min in 88% of the attacks, 3) the attack often recurred with intervals less than 30 min and ECG changes were often unaccompanied bt chest pain, 4) the attack was complicated with various kinds of arrhythmias. These features were in marked contrast to the cases with ST depression, in which attacks were evenly distributed over the night-time, of longer duration, sporadic in occurrence and far less complicated with arrhythmias. These data suggest that the difference of mechanisms causing attacks between both groups.

Adult↗
PubMed1979

Release of active and inactive renin by the human kidney.

1. Active and inactive renin were assayed in plasma of the renal veins and the inferior vena cava below the kidney in eight patients with hypertension and unilateral renal abnormalities, 20 min after the patients had resumed the upright position. 2. The concentration of active renin on the affected side was significantly higher than that on the non-affected side. The concentration of inactive renin on the affected side was significantly lower than that on the non-affected side and in the inferior vena cava. 3. These findings suggest either that the affected kidney mainly secretes active renin, which is then converted into inactive renin in the extrarenal circulation, or that the affected kidney activates inactive renin.

Enzyme Activation↗
PubMed1979

Enzyme immunoassay of angiotensin I.

A very sensitive and specific enzyme immunoassay has been developed for angiotensin I. Angiotensin I was coupled to beta-D-galactosidase by a novel cross-linking reagent, N-(meta-maleimidobenzoyloxy)succinimide. No decrease in the enzyme activity was observed during the coupling procedure. In the angiotensin I-beta-D-galactosidase conjugate, 0.39 mol immunoreactive angiotensin I/mol enzyme were present. A competitive assay with the enzyme-labeled angiotensin I was performed. Antibody-bound and free labeled antigen were separated from each other by the second antibody method, and the enzyme activity of the former was estimated. Using this assay, angiotensin I could be detected in the range of 1.2--50 pg. The sensitivity was 4.5-fold higher than that of the usual RIA. This assay distinguished clearly angiotensin I from angiotensin II, angiotensin III, and (Sar1, Ile8)-angiotensin II. The present method was applied to measure PRA in dogs; the results correlated fairly well with those obtained by the RIA (r = 0.94).

Angiotensin I↗