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Biomedical subjects

Y Orita

Publications and source records attributed to Y Orita.

At least 181 records · Page 10Linked to original sources
PubMed1981

Tissue and blood cell concentration of methylguanidine in rats and patients with chronic renal failure.

Methylguanidine concentration in blood cell of nondialysed patients with chronic renal failure was quantitatively determined by the method of the present authors. We also determined tissue methylguanidine concentrations in the liver, blood cell, kidney, colon, muscle and brain of uremic rat experimentally produced by Platt's method. Methylguanidine concentrations in blood cell and tissues except the brain of the uremic rats and in blood cell of the uremic patients were 5--7 times higher than those in their serums. An increased methylguanidine concentration in the liver of the uremic rat receiving 40% protein diet was observed. These results imply that methylguanidine acts as one of the important uremic toxins in the intracellular space except for the brain, and suggest that the liver specifically affects the formation of methylguanidine.

Animals↗
PubMed1981

Coronary arterial spasm in single coronary artery.

A 48-year-old man developed severe chest pain and became unconscious. Coronary cineangiography revealed single coronary artery of the type L2b by Sharbaugh and White. Ergonovine, 0.2 mg i.v., produced coronary arterial spasm in the right coronary artery. This case suggests that coronary arterial spasm might be a cause of sudden death in patients with single coronary artery. However, an association of single coronary artery and coronary arterial spasm might be coincidental.

Coronary Angiography↗
PubMed1981

Liquid-chromatographic determination of guanidino compounds in plasma and erythrocyte of normal persons and uremic patients.

We describe a method for determination of guanidino compounds in plasma and erythrocytes. The compounds are separated by liquid chromatography, the concentrations in the effluent being estimated fluorometrically (Trans. Am. Soc. Artif. Intern. Organs 24: 61, 1978). Guanidinoacetic acid, guanidinosuccinic acid, guanidinobutyric acid, guanidine, methylguanidine, taurocyamine, and arginine can be detected and quantitated in both plasma and erythrocytes from healthy individuals. The method was also applied to patients in chronic renal failure. Guanidinosuccinic acid, creatinine, guanidine, and methylguanidine are substantially increased in the plasma and erythrocytes of the uremic patient. Guanidino compounds can be effectively extracted from plasma with 0.5 volume of 300 g/L trichloroacetic acid, from erythrocytes with five volumes of 120 g/L trichloroacetic acid.

Chromatography, High Pressure Liquid↗
PubMed1980

Left atrial ball thrombus diagnosed by two-dimensional echocardiography.

The diagnosis of the ball thrombus in the left atrium has been very difficult by conventional clinical techniques. In the present case, two-dimensional echocardiography successfully demonstrated a spherical tumor moving in unpredictable directions in the left atrium. M-mode echocardiography did not clearly identify the tumor because of the limited visual width and spatial orientation of the technique; however, simultaneous recordings of the M-mode echocardiogram with phonocardiogram, carotid pulse wave, and electrocardiogram provided some diagnostic clues to the occlusive left atrial tumor. In the absence mitral valve occlusion by the tumor, a logarithmic correlation between the ejection time and the preceding R-R interval, and a negative lines correlation between Q to the first sound interval and the preceding R-R interval were found. In the beat following the appearance of the tumor in the mitral orifice, the sudden shortening of the ejection time and the prolongation of Q to the first sound interval were noted. Both of these findings are indirect evidence of decreased left ventricular filling associated with an elevated left atrial pressure resulting from the sudden mitral orifice obstruction by the tumor. Detailed analysis of the data obtained by the conventional noninvasive techniques could provide critical clues for the diagnosis of the occlusive left atrial tumor.

Blood Coagulation↗
PubMed1980

Detection of flail aortic valve in bacterial endocarditis with real-time two-dimensional echocardiography. A case report.

This report describes a case with flail right and noncoronary cusps due to bacterial endocarditis, diagnosed with real-time two-dimensional echocardiography. Real-time two-dimensional phased array sector scanner demonstrated 2 cugdel-shaped lesions in the region of the left ventricular outflow tract through the aortic root, pendulating upward and downward floating along the blood stream. This study shows that the real-time two-dimensional echocardiography is a very useful noninvasive tool in the early diagnosis of flail aortic valve.

Adult↗
PubMed1980

The change in the left atrial dimension during diastole. Echocardiographic assessment of mitral stenosis.

The change in the left atrial dimension during diastole was examined in patients with mitral stenosis using echocardiography. The left atrial emptying fraction (LAEF), defined as the ratio of enddiastolic dimension to endsystolic dimension of the left atrium, was 0.65 +/- 0.03 (mean +/- SE) for normal subjects, 0.86 +/- 0.01 for low grade mitral stenosis, and 0.92 +/- 0.01 for high grade stenosis. The LAEF correlated well with mitral valve area index (r = -0.70), but the correlation between E-F slope of the anterior mitral leaflet and mitral valve area index was less significant (r = 0.48). In patients who received mitral valve replacement the LAEF and the left atrial dimension significantly improved. The left atrial emptying fraction is an easily obtainable and reliable index to estimate the severity of mitral stenosis, even in patients who have undergone mitral valvular surgery.

Adult↗
PubMed1980

Simultaneous closure of the tricuspid and mitral valve in Ebstein's anomaly.

Echocardiographic studies of a 23-year-old man with Ebstein's anomaly and type B Wolff-Parkinson-White syndrome showed almost simultaneous closure of the tricuspid and mitral valve. After administration of edrophonium chloride, the tricuspid valve closed 20 msec earlier than the mitral valve. However, the closure of the mitral valve preceded that of the tricuspid valve after administration of ajmaline and atropine sulfate by 90 msec and 60 msec, respectively, concomitant with obliteration of preexcitation. From these observations, the simultaneous closure of the tricuspid and mitral valve of this case appears to depend on the preexcitation of the right ventricle.

Adult↗
PubMed1980

Interaction of calcium and microtubules in the action of cyclic AMP on the toad urinary bladder.

Involvement of microtubules in the cellular action of vasopressin was studied by physiological and biochemical procedures. The inhibitory effect of 10(-4) M colchicine on the hydro-osmotic response of the toad bladder to 2 mM cyclic AMP was completely blocked by an increase in the concentration of calcium in the serosal bathing medium from 1 to 8 mM. Most of the colchicine-binding activity of extracts of the bladder epithelial cells was recovered by DEAE-Sephadex chromatography in a procedure similar to that used to isolate tubulin of bovine brain. Sodium dodecyl sulfate urea and urea gel electrophoresis of the DEAE-Sephadex fraction from the bladder epithelial cells yielded bands that corresponded to those of bovine brain tubulin. When 8 mM CaCl2 was present in an incubation mixture, the binding of colchicine to tubulin from the bladder epithelial cells and bovine brain was significantly inhibited. However, 1 mM CaCl2 did not affect the binding of colchicine to tubulin. Although the present study supports the concept that microtubules and calcium play an important role in the cellular action of vasopressin on the toad urinary bladder, the mechanism by which calcium blocks the inhibitory effect of colchicine on the hydro-osmotic response to cyclic AMP could not be elucidated.

Animals↗
PubMed1980

Hypouricemia due to an isolated defect in renal tubular urate reabsorption.

During investigation of chronic glomerulonephritis, a 24-year-old man was found to have a low serum urate concentration (0.6-1.3 mg/100 ml). Daily urinary excretion of urate and oxypurines was normal. His urate clearance was markedly increased (43.3-98.0 ml/min), and was substantially unchanged after both the administration of pyrazinamide, an inhibitor of the renal tubular secretion of uric acid, and the administration of probenecid, an inhibitor of the renal tubular reabsorption of uric acid. No other renal tubular abnormalities were detected. It was concluded that the patient had an isolated defect in the renal tubular reabsorption of uric acid. The patient's brother was also found to have hypouricemia due to renal uricosuria, suggesting a genetic origin of the defect.

Adult↗
PubMed1980

The difference between serum and plasma complement activity in primary renal disease.

Low serum CH50 (s-CH50) levels were found in 16 out of 574 patients with primary renal disease. However, five of these 16 patients had normal plasma CH50 (p-CH50). The most characteristic finding in the complement profile in these sera was a marked reduction in C4 and C2 hemolytic activities with a minimal reduction in C3 and C5 activities. Sera separated at 37 degrees C showed almost normal CH50 levels, nearly equal to p-CH50, while sera prepared at room temperature and at 4 degrees C showed a remarkable decrease in their CH50 levels. Further, when the serum from one patient showing this difference was added to pooled normal human serum, the C4 activity of the mixture decreased markedly at 4 degrees C but not at 37 degrees C. It is concluded that the difference is caused by cold activation of serum complement through the classical pathway in vitro.

Adolescent↗