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Biomedical subjects

K Shiratori

Publications and source records attributed to K Shiratori.

At least 109 records · Page 6Linked to original sources
PubMed1986

Effect of licorice extract (Fm100) on release of secretin and exocrine pancreatic secretion in humans.

We investigated the effect of a fraction of licorice extract (Fm100) on release of endogenous secretin in seven human volunteers using radioimmunoassay and exocrine pancreatic secretion using a dye dilution technique with polyethylene glycol 4000 as a non-absorbable marker. Intrajejunal administration of Fm100 (pH 6.5) in three different doses (200, 400, and 800 mg/30 min) resulted in significant increases in both plasma secretin concentration and pancreatic bicarbonate output in a dose-dependent manner (r = 0.737, p less than 0.001, and r = 0.483, p less than 0.01, respectively). However, it did not influence pancreatic secretion of protein or amylase. The correlation between plasma secretin concentrations and bicarbonate outputs was also significant (r = 0.483; p less than 0.01). These results indicate that endogenous secretin is released by Fm100 in humans and suggest strongly that the increased pancreatic bicarbonate secretion is attributable to the increased plasma concentration of secretin.

Adult↗
PubMed1986

Endogenous cholecystokinin drives gallbladder emptying in dogs.

We investigated the effect of fat in the duodenum on the gallbladder emptying in seven dogs prepared with gastric, duodenal, and gallbladder cannulas. Gallbladder volume was measured at 15-min intervals, and venous blood samples were obtained at regular intervals for 2.5 h. Intraduodenal administration of Lipomul (pH 5.0, corn oil) in three different doses (1.1, 2.2, and 4.4 mmol/10 min) resulted in significant increases in gallbladder emptying in a dose-dependent manner (r = 0.8668, P less than 0.001). Likewise, the increase in integrated cholecystokinin (CCK) release in response to Lipomul was also dose dependent (r = 0.7334, P less than 0.001). A statistically significant correlation was found between integrated CCK release and gallbladder emptying in response to Lipomul (P less than 0.001). To determine the role of circulating endogenous CCK on gallbladder emptying effects of intravenous administration of proglumide and a rabbit anti-CCK serum on gallbladder emptying were studied. Gallbladder emptying was virtually abolished by the antiserum. Proglumide not only abolished the emptying but also increased gallbladder volume. Thus we conclude that in dogs the gallbladder emptying in response to fat in the upper small intestine depends on increased circulating endogenous CCK.

Animals↗
PubMed1986

A hormonal mechanism for the interdigestive pancreatic secretion in dogs.

We investigated a hormonal mechanism involved with cyclic pancreatic secretion in interdigestive state in four dogs prepared with gastric and modified Herrera's pancreatic cannulas and four dogs prepared with gastric and Thomas' duodenal cannulas. Cholecystokinin-pancreozymin (CCK-PZ), secretin, pancreatic polypeptide (PP), and motilin were considered as candidate hormones that might be involved in the mechanism. Radioimmunoassays of the four hormones in serial plasma samples showed cyclic increases in only two hormones including motilin and PP, which coincided with the cyclic increase in pancreatic secretion. However, only motilin given intravenously produced a cyclic pancreatic secretion similar to spontaneous cyclic pancreatic secretion in interdigestive state. Although the magnitude of peak pancreatic secretion was not altered during intravenous infusion of motilin in doses of 0.06 microgram X kg-1 X h-1 or 0.06 microgram/kg, the peak secretion occurred more frequently than that during the control interdigestive state. Atropine administered intravenously abolished the cyclic increases in both plasma motilin concentration and pancreatic secretion. Exogenous secretin, CCK-PZ8 and PP failed to produce cyclic pancreatic secretion. To further elucidate the mechanism involved, the effect of intravenous infusion of a rabbit anti-CCK-PZ or antimotilin serum on the cyclic pancreatic secretion was studied. The antimotilin serum completely blocked the pancreatic secretory cycles in two dogs so studied, whereas rabbit anti-CCK-PZ serum did not influence the pancreatic cycle in two dogs. We conclude that circulating motilin plays an important role on the development of cyclic increase in the pancreatic secretion in two dogs so studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Mechanical and electrocardiographic sequence of coronary artery occlusion: an echocardiographic study during coronary angioplasty].

The detection of regional myocardial dysfunction due to acute ischemic event has been limited almost entirely to experimental animal models. In human subjects, it has been limited to the observations during spontaneously-occurring or exercise-induced ischemic events. Recently, percutaneous transluminal coronary angioplasty (PTCA) provides an opportunity to study such dysfunction as the result of repeated interruptions of coronary blood flow. Echocardiograms and electrocardiograms were simultaneously recorded immediately before, during, and after 21 episodes of complete interruptions of coronary blood flow by PTCA in 11 patients. No patient had asynergy of the left ventricle either by two-dimensional echocardiography (2DE) or angiography. All patients had isolated single coronary artery stenosis including the left anterior descending artery in nine, left circumflex artery in one and right coronary artery in one. Recordings of M-mode and 2DE were successfully obtained in 10 patients. After balloon inflation, regional asynergy in the distribution of the instrumented coronary artery appeared in all 10 patients. Hypokinesis developed 9 +/- 3 (means +/- SD) sec after balloon inflation and progressed rapidly to akinesis or dyskinesis. At the same time, decreased systolic thickening of the left ventricular wall appeared in some patients in relation to the development of regional asynergy. However, systolic thinning of the left ventricular wall was not noted in all. The regional asynergy preceded ischemic electrocardiographic changes and had no relation to chest pain. Left ventricular wall motion began to normalize 12 +/- 3 sec after balloon deflation. Thereafter, transient hyperkinesis of the left ventricle developed. The first ischemic electrocardiographic change was a negative U wave which appeared 13 +/- 7 sec after coronary occlusion and remained 3 to 4 sec. Tall T waves were recorded at 28 +/- 12 sec and significant ST elevations developed 31 +/- 11 sec, after balloon inflation. These electrocardiographic changes invariably occurred only after the onset of wall motion abnormalities. Normalization of T waves was recognized at 17 +/- 16 sec and ST segment deviation were no longer present at 18 +/- 10 sec, after reperfusion. These electrocardiographic changes also preceded normalization of regional myocardial dysfunction. In conclusion, left ventricular wall motion abnormalities after coronary occlusion invariably precede the electrocardiographic changes, and begin to normalize after reperfusion prior to the electrocardiographic recovery.

Adult↗
PubMed1986

[Non-rheumatic multivalvular regurgitation in an older population: a pulsed Doppler echocardiographic study].

To assess the incidence of valvular regurgitation, 180 patients more than 40 years of age without cardiac symptoms were studied by pulsed Doppler echocardiography. The 180 patients were categorized by age as group 1, 40 to 49 years; group 2, 50 to 59 years; group 3, 60 to 69 years; group 4, 70 to 79 years; and group 5, more than 80 years of age. The incidence of valvular regurgitant flow signals increased significantly with age. Multivalvular regurgitation were often detected in groups 4 and 5. Furthermore, acoustically silent regurgitation at each valve was frequently noted (71 of 85 cases with valvular regurgitant flow signal: 84%). Mitral valve prolapse was diagnosed by two-dimensional echocardiography in 27 patients, but a mid-systolic click or pansystolic murmur with late-systolic accentuation was not noted. In conclusion, valvular regurgitations were common in the aged who lacked auscultatory findings.

Adult↗
PubMed1986

[Value of right ventricular and atrial collapse in identifying cardiac tamponade].

Collapse of the right ventricle and right and left atria is observed in cardiac tamponade. To assess the diagnostic value of each collapse component in identifying cardiac tamponade, two-dimensional and M-mode echocardiograms were recorded simultaneously with the measurement of intrapericardial pressure in five patients as they underwent pericardiocentesis. Before pericardiocentesis, each patient had evidence of right ventricular and right atrial collapse. In addition, left atrial collapse was observed in four patients. During pericardiocentesis, left atrial collapse initially resolved accompanied by a drop in pressure in the pericardial sac. Continuous drainage of pericardial effusion resulted in significant symptomatic improvement and the cessation of paradoxical pulse at the point of resolution of right ventricular collapse. However, right atrial collapse persisted after resolution of right ventricular collapse, but it was absent when pericardiocentesis was completed. Injection of saline solution with heparin into the pericardial sac for cleansing initially caused right atrial collapse, while right ventricular collapse developed with the appearance of cardiac tamponade. In one patient, the simultaneous recording of right ventricular and intrapericardial pressures and two-dimensional echocardiograms demonstrated that right ventricular collapse occurred early in diastole, when intrapericardial pressure exceeded right ventricular pressure. In conclusion, right ventricular collapse is the most reliable sign of cardiac tamponade. Right atrial collapse occurs in the early stage of cardiac tamponade. Left atrial collapse appears very late in the course of hemodynamic deterioration due to cardiac tamponade.

Adult↗
PubMed1985

[Functional transvalvular regurgitation in patients with Björk-Shiley aortic valves: a pulsed Doppler echocardiographic study].

It is well known that a small amount of regurgitation occurs through Björk-Shiley valves. Obviously, this functional regurgitation is related to the construction of the Björk-Shiley valve, wherein the disc does not overlap the ring, but fits within its orifice, leaving a minimal space between the edge of the disc and the ring. The aim of this study was to evaluate the clinical significance of regurgitation in patients having Björk-Shiley valves in the aortic position by pulsed Doppler echocardiography. The study group consisted of 46 patients with normally functioning valves and five patients with malfunctioning valves. Valve dysfunction resulted from paravalvular regurgitation in three, and thrombosed valves in two (confirmed by surgery and angiography). Using pulsed Doppler echocardiography, aortic regurgitation was observed in 29 of the 46 normally functioning Björk-Shiley aortic valves. Among these, regurgitant flow signals were constantly located in the vicinity of the valve ring in the left ventricular outflow tract. Therefore, these regurgitant flow signals were considered to represent functional regurgitation of the Björk-Shiley valve. Aortography was performed for 11 of the 46 normally functioning Björk-Shiley valves, and there was minimal transvalvular regurgitation in all. In all of the five malfunctioning Björk-Shiley aortic valves, aortic regurgitant flow signals were detected by pulsed Doppler echocardiography, and the maximal distance of the regurgitant flow signals from the Björk-Shiley valve ring was more than 0.5 cm. However, it was difficult to differentiate transvalvular regurgitation from paravalvular regurgitation using pulsed Doppler technique alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1985

[Tricuspid regurgitation evaluated by Doppler hepatic vein flow patterns].

Hepatic vein flow can be reliably measured because Doppler sampling volumes are easily oriented parallel with the course of the hepatic vein. In this study, the relationship between the Doppler signal in the hepatic vein and the external jugular vein pulse was evaluated, and the contribution of the Doppler echocardiography to the quantitative diagnosis of tricuspid regurgitation was also assessed. The subjects consisted of five healthy persons, four patients with lone atrial fibrillation, 27 patients who underwent cardiac surgery, and 34 patients with tricuspid regurgitation. The severity of the regurgitation was judged by right ventriculography and inferior caval angiography. The pattern of the Doppler hepatic vein flow mimicked that of the jugular phlebogram in each patient. The normal hepatic vein flow consisted of two forward flows toward the heart; one in systole; the other, in diastole, and one retrograde flow toward the liver during atrial contraction. In patients with lone atrial fibrillation, a systolic backward flow toward the liver or a decrease in the systolic forward flow was observed, though there was no tricuspid regurgitation. In patients who had cardiac surgery, a systolic backward flow toward the liver or a decrease in the systolic forward flow was usual. However, a prominent systolic backward flow toward the liver was observed in patients with severe tricuspid regurgitation, and a decreased systolic forward flow toward the heart was observed in patients with moderate tricuspid regurgitation in sinus rhythm. We concluded that Doppler measurement of hepatic vein flow does not contribute to the diagnosis of tricuspid regurgitation in the presence of atrial fibrillation or in postoperative conditions, but that it is useful in identifying severe tricuspid regurgitation.

Coronary Artery Bypass↗
PubMed1985

Proflamin, a new antitumor agent: preparation, physicochemical properties and antitumor activity.

Proflamin is a new biological response-modifying antitumor agent. It was isolated from the culture mycelium of Flammulina velutipes (Curt. ex Fr.) Sing. by means of ion exchange column chromatography and molecular sieving. It is a weakly acidic glycoprotein containing more than 90% protein and less than 10% carbohydrate, and its molecular weight is 13,000 +/- 4,000. The antitumor effect of proflamin was studied with murine tumors. It was markedly effective against the syngeneic tumors, B-16 melanoma (B-16) and adenocarcinoma 755 (Ca-755). At a dose of 10 mg/kg po, the increases in median survival time of mice with B-16 and Ca-755 were 86 and 84%, respectively. Proflamin exhibited no cytocidal effect against the cultured cell lines in vitro. Oral administration of proflamin produced no lethal or any other apparent adverse effect in mice.

Adenocarcinoma↗
PubMed1985

[Cor triatriatum dexter: a case report with particular reference to the echocardiographic features].

A patient with a double-chambered right ventricle and cor triatriatum dexter was presented. The non-invasive diagnosis of cor triatriatum dexter was stressed. A plate-like echo was imaged in the right atrium using two-dimensional echocardiography. It divided the atrium into two chambers. Contrast echocardiography revealed delayed filling of the lower portion of the atrium. Pulsed Doppler echocardiography demonstrated systolic turbulence in the lower portion of the atrium, indicating that the plate-like structure produced a stenosis in the right atrium. We conclude that non-invasive methods including contrast echocardiography and pulsed Doppler echocardiography, are effective in identifying stenoses in the right atrium.

Adult↗