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Biomedical subjects

O Yamada

Publications and source records attributed to O Yamada.

At least 253 records · Page 14Linked to original sources

[Clinical study of membranous ventricular septal defect in infancy and childhood by two-dimensional echocardiography].

A two-dimensional echocardiographic study was performed in patients (pts) with isolated ventricular septal defect (VSD). Group I included 48 pts with membranous VSD (aged from 3 months to 11 years) diagnosed by cardiac catheterization and angiocardiography. In 25 of 27 pts demonstrated a defect only by two-dimensional echocardiography (2DE), mean pulmonary artery pressure (MPAP) was higher than 25 mmHg and 26 of these 27 pts showed a large left to right shunt of more than 30 per cent, and the remaining one pt had Eisenmenger complex. In 15 of 16 pts demonstrated VSD with the pouch formation of the septal leaflet (PSL) by 2DE, MPAP was lower than 25 mmHg. These 16 pts showed various left to right shunt ratios (small to large). In all 4 pts demonstrated VSD with membranous septal aneurysm (MSA) and 1 pt demonstrated no findings by 2DE, MPAP was low (under 25 mmHg) and a left to right shunt was small. Group II included 400 pts with membranous VSD (aged 11 days to 15 years) diagnosed clinically. All 221 pts demonstrated VSD had PSL or MSA. PSL was demonstrated in 261 pts, MSA in 27 pts, both PSL and MSA in 33 pts and no findings in 79 pts by 2DE. Group III included 41 pts with spontaneous closed VSD (aged 3 months to 8 years) diagnosed clinically. PSL was demonstrated in 15 pts, MSA in 11 pts and no findings in 15 pts by 2DE. On the basis of these observation, PSL and MSA may play an important role in spontaneous diminution or closure of membranous VSD, and in most of VSD pts without PSL and MSA pulmonary hypertension is shown and spontaneous diminution of VSD size can not be anticipated. Visualization of PSL and MSA by 2DE may predict the prognosis and is clinically very useful in the management of pts with isolated membranous VSD.

Blood Pressure↗

An organic and functional staging classification. A measurement of disability in otolaryngology.

The quantitative measurement of organic and functional problems is assessed by a staging classification that is a measurement of the severity of a patient's condition. The method separates a medical problem or disease into three stages. Stage 1 indicates disease with no complications or a problem of minimal severity. Stage 2 is disease with local complications or a problem of moderate severity. Stage 3 denotes disease with systemic complications or a problem of a serious nature. Eight examples in otorhinolaryngology are given to demonstrate the feasibility of developing scales that quantify organic and functional disability. The scale will be useful in evaluating diagnostic efficiency of physicians as well as to measure prognosis, therapeutic effectiveness, and medical care costs.

Acute Disease↗

Deleterious effects of endotoxin on cultured endothelial cells: an in vitro model of vascular injury.

The effects of endotoxin-triggered granulocytes on the viability of endothelial cells in vitro was investigated. Endotoxin or its lipid A component caused granulocytes to adhere to and significantly damage cultured endothelial cells. Fresh serum is not necessary but does amplify both adherence and endothelial injury. Much of the endothelial injury was inhibited by free-radical scavengers or by blocking granulocyte adhesion to endothelial cells and appears to result from free radical production by the stimulated granulocyte. Studies in this model suggest a pathogenic role for the endotoxin-triggered granulocyte in the Shwartzman reaction and perhaps related clinical disorders.

Bacterial Toxins↗

Cholesterol and atheroma lipids activate complement and stimulate granulocytes. A possible mechanism for amplification of ischemic injury in atherosclerotic states.

Previous studies in experimental myocardial infarction have suggested that PMNs and plasma C might interact to intensify ischemic injury. From the finding of large amounts of activated C (specifically C5a) in the plasma of a patient with severe, ulcerating atherosclerosis and the cholesterol embolization syndrome, we postulated that crystalline cholesterol might activate C and thereby amplify infarctive tissue damage. On simple incubation, crystalline cholesterol--as well as lipids from atheromata--activated plasma C; such plasma then potently aggregated normal PMNs and provoked them to damage cultured endothelial cells in vitro. The active principle in cholesterol-incubated plasma was of molecular weight and antigenicity consistent with C5a (or C5a[desarginine]). Optimal activation required the presence of Ig and an intact classical C pathway. Exposure of plasma to crystalline cholesterol by ulceration of, or hemorrhage into, atherosclerotic plaques might therefore activate C in vivo, promoting further ischemic damage by causing leukostatic-leukoembolic compromise of small vessels downstream from the site of activation.

Arteriosclerosis↗

[Two-dimensional echocardiography of coronary artery in Kawasaki disease (MCLS): detection, changes in acute phase, and follow-up observation of the aneurysm (author's transl)].

Two-dimensional echocardiography (2-D echo) was performed before coronary angiography in 213 patients (pts), 4 months to 12 years old, with a history of Kawasaki disease (MCLS). In 10 pts, 2-D echo was performed almost everyday during acute phase. In 23 pts, coronary artery aneurysms were followed up for more than 6 months by 2-D echo. In 32 of 213 pts, the presence of coronary artery aneurysms (9 pts with left, 4 pts with right and 19 pts with both coronary arteries) were proved by coronary angiography. The correct diagnosis was achieved prospectively by 2-D echo in 26 of 32 pts with coronary artery aneurysm (in 24 of 28 pts with left and 15 of 23 pts with right coronary artery aneurysm). In all 10 pts with acute phase of MCLS, an increased echocardiographic density around the coronary artery and of the coronary artery itself continued from the 4th or 6th day to the 10th day or near the second month of the illness. The findings were considered due to acute perivasculitis and vasculitis in the coronary artery. In 5 of 10 pts, the dilatation of coronary artery was demonstrated on about 6th day of the illness and in 3 pts was transient, but in other 2 pts the dilated coronary arteries grew up aneurysms on the 9th and 13th day of the illness. In 23 pts with coronary artery aneurysm followed up by 2-D echo for more than 6 months, 18 pts were started to observe within 6 months and 5 pts beyond 1 year after the onset of illness. In the former, the size of aneurysm was markedly reduced in 7, slightly reduced in 6, and did not change in 5 pts. On the other hand, it did not change in all the 5 pts of the latter. This study suggests that 2-D echo is very useful to diagnose noninvasively coronary artery aneurysm in pts with the history of MCLS and to detect and follow-up it in acute phase.

Aneurysm↗

[Two-dimensional echocardiographic diagnosis of congenital malformations of the aorta in infants and children (author's transl)].

Two-dimensional echocardiographic studies were performed in 23 patients with coarctation of the aorta, 5 with interruption of the aortic arch, 6 with supravalvular aortic stenosis, 3 with truncus arteriosus, 2 with anomalous origin of the right pulmonary artery from the ascending aorta and 2 with aorto-pulmonary septal defect. The diagnosis was confirmed in each patient by surgery and/or cardiac catheterization and angiography. Visualization of the junction of isthmus and the descending aorta was possible in 18 of 23 patients with coarctation by two-dimensional echocardiography. In 13 patients correct diagnosis was obtained prospectively and in 2 patients coarctation was detected retrospectively. In only one of the 5 patients with interruption correct diagnosis was obtained and in 3 patients it was difficult to differentiate interruption from coarctation. In 5 of the 6 patients with supravalvular aortic stenosis, visualization of the area of obstruction was possible to two-dimensional echocardiography. In 2 of the 3 patients with truncus arteriosus, in whom none of the 2 had anomalous origin the right pulmonary artery from the ascending aorta and one of the 2 had aorto-pulmonary septal defect, correct diagnosis was obtained prospectively by two-dimensional echocardiography. Two-dimensional echocardiography may offer a useful noninvasive method for the direct visualization of aortic obstructive lesions and aortic malformations.

Angiography↗