Search PubMed⌕ Search

Biomedical subjects

K Tsunoda

Publications and source records attributed to K Tsunoda.

At least 163 records · Page 9Linked to original sources
PubMed1984

Renal prostaglandin E in the hypotensive mechanism of MK-421 in conscious rats.

To assess the role of renal prostaglandin E in the hypotensive mechanism of MK-421, we evaluated the effects of chronic infusion of MK-421 (6 mg/kg/day i.p.) on systolic blood pressure and urinary prostaglandin E excretion in conscious rats in states of sodium repletion or depletion and also during chronic infusion of norepinephrine (1.8 mg/kg/day i.p.) or vasopressin (7.2 U/kg/day i.p.). The hypotensive effect of MK-421 was greater in sodium depleted than in sodium repleted rats. The hypertensive effect of norepinephrine or vasopressin was inhibited by the simultaneous administration of MK-421. MK-421 induced an increase in the excretion of urinary prostaglandin E, in both sodium repleted and depleted rats. However, simultaneous administration of MK-421 had no influence on the increase in urinary prostaglandin E excretion induced by norepinephrine or vasopressin. In addition, the combined administration of MK-421 with indomethacin (10 mg/kg/day s.c.) still abolished the hypertensive effect of norepinephrine or vasopressin. The disparate effect of MK-421 on urinary prostaglandin E excretion suggests that the renal prostaglandin system is not essential for the mechanism of the hypotensive effect of MK-421.

Angiotensin I↗
PubMed1982

[Assessment of an intracardiac mural thrombus by contrast enhanced computed tomography].

The usefulness of computed tomography (CT) in the diagnosis of an intracardiac mural thrombus was examined by comparing with two-dimensional echocardiography (2-DE), left ventricular cineangiography (LVG), and operative findings. The following results were obtained: 1) Left atrial thrombi: Among 43 cases of valvular disease with mitral stenosis, left atrial thrombi were noted in 10 cases (13 regions) by CT. Out of these 13 regions, 2-DE detected six regions (Fig. 2). Among 11 patients who underwent operation, thrombi were present in four (six regions). Of these six regions, thrombus was suspected in one region and another one was undetectable, but detected in the remaining four regions by CT and was in good accord with the operative findings (Table 1). Left atrial thrombi were detected in two of 138 cases of coronary heart disease, and in one of 26 cases of cardiomyopathy by CT. 2) Left ventricular thrombi: Left ventricular thrombi were detected in 26 of 122 cases of myocardial infarction (21%) by CT, and had a particularly high incidence in the cases having a ventricular aneurysm (Fig. 4). Of 81 cases in which 2-DE was performed, left ventricular thrombi were detected in 13 cases by both CT and 2-DE, and were not detected in 59 cases by both methods. In nine cases 2-DE diagnosis was not consistent with CT (Table 2). Of 76 cases in which left ventricular cineangiography was performed, left ventricular thrombi were detected in 12 cases by both CT and LVG, and were not detected in 58 cases by both methods. There were six cases of disaccord between 2-DE and CT (Table 2). In two of five cases of congestive cardiomyopathy, left ventricular thrombi were noted by CT. CT was able to detect thrombi in the left atrial appendage, the left atrial lateral wall (Fig. 6), and the regions near the left ventricular apex, which were difficult to be investigated by 2-DE (Fig. 8). CT was, in particular, superior in depicting the size, location and property of thrombi. In addition, CT was able to depict clearly a small thrombus in the left ventricular apex to the extent of, or better than, left ventriculography. Therefore, contrast enhanced CT is a useful diagnostic method for the detection of intracardiac mural thrombi.

Cineangiography↗
PubMed1982

[Estimation of infarct size with 201Tl by multiprojection analysis].

Since mortality resulting from cardiac arrhythmia has been decreased by an introduction of CCU, power failure has become the major cause of death in patients with acute myocardial infarction. The power failure is assumed to be related to an infarct size. Therefore, noninvasive quantification of the infarct size is required for proper assessment of prognosis and treatment. Recently, a scintigraphic technique using radionuclide thallium-201 has developed, which is accumulated not in myocardial necrosis but in the intact myocardium. In this study, we tested two different parameters expressing the infarct size based on 5-projection myocardial scintigrams. One parameter is the ratio of the defect area to the total myocardium (% area), and the other is the ratio of a count decrease by the defect to total counts (% loss counts) in the planar image. Each parameter was obtained from uni- and multi-projection analysis. Six items were selected in the study including % area of 1-projection analysis, % area of 3-projection analysis, % area of 5-projection analysis, % loss counts of 1-projection analysis, % loss counts of 3-projection analysis, and % loss counts of 5-projection analysis. In 56 patients with the first attack of acute myocardial infarction, these parameters showed a clinically acceptable correlation with ejection fractions obtained by contrast ventriculography performed about 4 weeks later, with pulmonary end-diastolic pressure shortly after the onset, and with peak-CPK and sigma CPK obtained by 4 or 6 hourly measurements. Correlation coefficients between two parameters among 6 items showed no difference from each other. Scintigraphy was performed more than twice in 11 patients and the infarct size of these patients was decreased with the clinical course. Validity for estimates of the infarct size obtained with two parameters (% loss counts and % area) in different projection analysis was examined by a phantom model experiment and the clinical implications were discussed. In conclusion, an infarct size estimated by 201Tl scintigraphy provides useful informations about the size of necrosis and cardiac function in patients with acute myocardial infarction.

Adult↗