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Biomedical subjects

H Nagata

Publications and source records attributed to H Nagata.

At least 361 records · Page 20Linked to original sources
PubMed1982

[Exercise two-dimensional echocardiography: correlation between exercise induced asynergy and coronary artery lesions].

Exercise two-dimensional (2-D) echocardiography was performed in patients with suspected coronary artery disease, and exercise induced left ventricular asynergy was evaluated qualitatively and was compared with the coronary artery stenosis and electrocardiographic ST changes. Subjects were 12 patients with angina of effort, 8 patients with spontaneous angina, 8 patients with chest pain syndrome with the normal coronary artery, and 7 patients with hypertrophic cardiomyopathy (HCM). Cases with myocardial infarction were excluded from this study. 1) Left ventricular asynergy during exercise was observed in 10 and ST depression in 11 of 12 patients with angina of effort. In patients with spontaneous angina, left ventricular asynergy and ST depression during exercise were observed in 2 of 8 patients without anginal pain, and both patients had coronary artery stenosis of 90% or more. 2) Exercise induced asynergy was also observed in 4 of 7 patients with HCM without coronary artery stenosis. It seemed likely that the markedly hypertrophied myocardium and impairment of left ventricular compliance and relaxation may induce relative myocardial ischemia.

Adult↗
PubMed1982

[Cross-sectional echocardiographic visualization of the infarcted site in myocardial infarction: correlation with electrocardiographic and coronary angiographic findings].

Three dimensional assessment of the site of myocardial infarct was performed using cross-sectional echocardiography in 68 patients with old myocardial infarction. Patients with a history or electrocardiographic findings suggestive of double or multiple infarctions were excluded from the study. In patients with abnormal Q waves in V1 to V3, a regional wall motion abnormality (asynergy) was observed in the anterior portion of the interventricular septum (IVS) and the anterior free wall of the left ventricle (LV) which was extended from the base to apex. Most of them had a significant stenosis in the left anterior descending artery (LAD) distal to the first diagonal branch. Patients with Q waves in V1 to V5 or V6 showed extensive asynergy in the anterior IVS, anterior and lateral free walls of the LV extended from the base to apex. LAD stenosis proximal to the first diagonal branch seemed to be the corresponding coronary lesion. In patients with Q waves in V3 to V5 or V6, asynergy was limited to the apical half of the anterior wall of the LV. In patients with Q waves in II, III and a VF, asynergy was observed in the basal half of the posterior wall and the posterior portion of the IVS.

Coronary Angiography↗
PubMed1981

Changes in endocrine activities relative to obesity in patients with essential hypertension.

The possible role of obesity in the development of hypertension was investigated in two study groups. In a population study of 961 subjects, 739 were found to be normotensive and 222 hypertensive. The prevalence of hypertension was 18.7 percent in the nonobese, and 33.2 percent in the obese subjects. Systolic and diastolic blood pressures increased progressively with the increase of relative body weight in both normotensive and hypertensive subjects. In addition, an endocrinologic study was made of 97 patients with essential hypertension; in 82, plasma renin activity (PRA) was inversely correlated with the increase of relative body weight but not with urinary Na excretion. Despite this decrease of PRA, the level of serum aldosterone was not influenced by relative body weight. Thus, the aldosterone/PRA ratio ratio increased progressively with the increase of relative body weight. Thiazide therapy normalized this inappropriately high ratio, and reduced body weight and blood pressure. Restriction of dietary calories and salt intake had a similar effect. With a high-salt intake in an obese subject, the aldosterone/PRA ratio is unduly increased. Apparently aldosterone contributes to the additional retention of sodium and water and thereby promotes hypertension in the presence of an expanded fluid volume.

Adult↗
PubMed1981

A screening test to identify aldosterone-producing adenoma by measuring plasma renin activity. Results in hypertensive patients.

In an attempt to devise a screening test for aldosterone-producing adenoma (APA) among hypertensive patients, the serum sodium and potassium levels, plasma renin activity (PRA), plasma aldosterone concentration, and aldosterone-PRA ratio were measured in 348 patients with hypertension. Nine patients with a substantially elevated aldosterone-PRA ratio were selected and hospitalized for further investigations. All nine patients were then recognized by scintigraphy with labeled cholesterol, venography, and surgical excision as having APA. The serum concentration of potassium was subnormal in three of nine patients with APA. In patients with APA, administration of diuretics and salt restriction significantly elevated PRA. However, even under notable diurnal and day-to-day variations of plasma aldosterone concentrations, the aldosterone-PRA ratio was always elevated inappropriately (more than 400) in patients with APA. In contrast, after administration of diuretics, both the PRA and aldosterone levels increased significantly in patients with essential hypertension, but the aldosterone-PRA ratio was less than 200. Since the renin-angiotensin system seems to be a major factor controlling aldosterone secretion in normal subjects, it is suggested that an elevation of aldosterone-PRA ratio more than 400 is a useful screening tool for the prediction of APA among hypertensive patients.

Adenoma↗
PubMed1981

[Vesico-ureteral reflux (VUR) and renal size in children (author's transl)].

UNLABELLED: We analyzed the radiographic renal size of 180 children with vesico-ureteral reflux as compared with that of 159 normal children. We measured on urogram the vertebral length, renal length and thickness of the renal cortex. Further, the ratio of the renal length to the vertebral length and the cortical thickness to the renal length were computed. The latter was named the cortical ratio. IN CONCLUSION: 1. The cortical ratio is the most useful parameter in analysis of the renal size. 2. Cortical damage due to VUR is noted already in newborns. This result suggests that vesico-ureteral reflux must be detected and treated in early childhood.

Adolescent↗
PubMed1981

[Detection of exercise induced left ventricular asynergy by two-dimensional echocardiography (author's transl)].

In order to detect an exercise induced asynergy, cross-sectional echocardiography was performed during multistage maximal bicycle ergometer stress test in the supine position. 1) Left ventricular (LV) asynergy occurred earlier than or simultaneously with the appreciable ST segment change. 2) In patients with angina, LV asynergy appeared in the area of dominant coronary stenosis, while ST depression was seen in V3-6 as well as II, III and aVF, despite of the localized area of asynergy. 3) In patients with myocardial infarction, LV asynergy increased or extended over or around the infarcted area except one case, ST segment elevated in the leads over the infarction with abnormal Q waves and depressed in the reciprocal leads. These observations revealed that ST depression does not necessarily mean an occurrence of new ischemia over the corresponding area in myocardial infarction. Thus exercise cross-sectional echocardiography was demonstrated to be a good method to detect an exercise induced ischemia and would be particularly valuable in view of the coronary artery bypass.

Adult↗
PubMed1980

Pathological and pathophysiological study on intestinal lymphatic system in fat absorption.

Pathological and pathophysiological study on the intestinal lymphatics was carried out clinically and experimentally. Jejunal biopsy study revealed marked dilatation of intestinal lymphatics in liver cirrhosis with ascites and Behçet's disease as well as protein-losing enteropathy. Lymphangiographic study showed also abnormal findings in above-mentioned diseases. In cases of McKee dogs in which mechanism of blockade of lymphatic flow was already clarified, McKee dogs showed marked malabsorptive of fat. When lymphatic flow was blocked mechanically at the thoracic duct, fat accumulation was seen in the absorptive cells as well as in dilated intestinal lymphatics. In administration of colchicine to rats, fat accumulation was seen in the matrix of absorptive cells as well as in the endoplasmic reticulums and Golgi apparatus. However, amorphous substances instead of chylomicrons were seen in dilated intestinal lymphatics. These studies suggested that a tract of fat transportation from intestinal cells to the thoracic duct should be considered as a functional unit in fat absorption.

Animals↗