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Biomedical subjects

Y Nimura

Publications and source records attributed to Y Nimura.

At least 73 records · Page 4Linked to original sources
PubMed1989

Stimulated rat liver mitochondrial biogenesis after partial hepatectomy.

In order to elucidate the response of mitochondria to the increase in cellular energy demand after hepatectomy, we have examined the effects of partial hepatectomy and hepatic artery ligation on the energy-transducing system of rat liver mitochondria. Specific content of DNA in the mitochondria increased on the first day after the hepatectomy and reached 150% of the original value. Oxidative phosphorylation capacity of the mitochondria started to increase on the first postoperative day. In contrast, specific enzymic activities, specific cytochrome contents, and subunit contents of the energy-transducing complexes in the isolated mitochondria were significantly increased only from the second postoperative day. The ligation of the hepatic artery did not inhibit the amplification of the mitochondrial function. The immunostain for ubiquinol-cytochrome c oxidoreductase was increased predominantly in the portal area of the hepatic lobules of the hepatectomized rats. These results suggest that enhancement of the mitochondrial oxidative phosphorylation system after hepatectomy is based on the increase of the amount of the complexes in the inner membrane, which is closely related to replication of mitochondrial DNA, and that the blood supply from the hepatic artery is not an important factor in the mitochondrial amplification in rats.

Animals↗
PubMed1989

Diastolic atrioventricular valve closure and regurgitation following atrial contraction: their relation to timing of atrial contraction.

Some authors have proposed that atrial contraction per se is able to close the atrioventricular (AV) valves. To determine whether tight closure of the AV valves can be accomplished solely by atrial contraction, the existence of diastolic regurgitation following atrial contraction and its relation to the PQ interval were examined in 13 patients with AV block (2 of the first degree, 4 of the second degree, and 7 of the third degree), using pulsed Doppler echocardiography, which allowed noninvasive estimation of valvular regurgitation in the physiological state. Diastolic mitral and tricuspid regurgitations were detected in the left and right atria near the respective AV valves in all 13 patients despite different degrees of AV block, while these valves were observed to be in apparently closed position during regurgitation on the two-dimensional and M-mode echocardiograms. The duration of regurgitant signals was prolonged with an increase in the PQ interval in the electrocardiogram, but it became short again as the P wave approached the preceding rapid filling wave. These results suggest that atrial contraction may initiate the closure of the AV valves but is not capable of closing the valves tightly, and atrial contraction with long PQ interval may contribute little to augmentation of cardiac output in patients with AV block.

Echocardiography, Doppler↗
PubMed1989

Sphincter of Oddi response to caerulein after endoscopic sphincterotomy for papillary stenosis.

Using a percutaneous transhepatic cholangioscopy (PTCS) catheter, sphincter of Oddi motility was measured in a patient with papillary stenosis secondary to bile duct stones. Prior to sphincterotomy, intramuscular injection of 20 micrograms caerulein did not inhibit pathological contraction waves of the sphincter of Oddi or relieve abdominal pain. Endoscopic sphincterotomy of the lower segment of the sphincter of Oddi resulted in recovery of the normal response to caerulein, i.e. relaxation of the sphincter of Oddi. This observation indicates that the pathological contraction and lack of relaxation to cholecystokinin in a patient with papillary stenosis is due to high common bile duct pressure. The measurement of motility of sphincter of Oddi via the PTCS route is useful in diagnosing motor disorders in the sphincter of Oddi and is helpful in deciding to perform endoscopic sphincterotomy.

Aged↗
PubMed1989

Hemodynamic and prognostic value of thallium-201 myocardial imaging in patients with dilated cardiomyopathy.

We studied 70 patients with dilated cardiomyopathy to determine whether extent of perfusion defect on thallium imaging could be related to the hemodynamics and prognosis of the patients. Patients were divided into three groups according to the extent of perfusion defect, i.e., Grade I: no perfusion defect (n = 19), Grade II: apical perfusion defect (n = 22), and Grade III: extensive perfusion defect (n = 29). The patients of Grade III demonstrated marked hemodynamic deterioration compared with those of Grade I and II. Three-year survival rate showed lower value in proportion to the extent of perfusion defect (P less than 0.05). Death from progressive heart failure tended to occur in patients with extensive perfusion defect (P less than 0.05). In patients of Grade III, the perfusion defect extended mainly to the posterolateral segment. Although autopsy studies showed increased fibrosis in the left ventricular wall in these patients, the extension of the fibrosis was not related to that of fibrosis. Moreover, the perfusion defect had regressed in three of 18 patients in the follow-up examination. These results indicate that the extent of perfusion defect on thallium imaging may be of value in non-invasive evaluation and prediction of the prognosis in patients with dilated cardiomyopathy. Distribution of the perfusion defect was, however, not related to that of myocardial fibrosis.

Adolescent↗
PubMed1989

Cholangioscopic differentiation of biliary strictures and polyps.

Since April 1977 percutaneous transhepatic cholangioscopy (PTCS) has been carried out in 428 cases comprising 213 cases of malignant disease and 215 benign cases. PTCS is performed through the dilated sinus track of percutaneous transhepatic biliary drainage. When irregularly dilated and tortuous vessels, which we called tumor vessels, are revealed on biliary strictures or polyps, a correct diagnosis of cancer can be made. Benign biliary strictures with or without gallstones, or polypoid lesions without tumor vessels such as granulomas, can be differentiated by cholangioscopic biopsy. The positive rate of cholangioscopic biopsy in 57 cases of bile duct cancer was 96%. PTCS should be used pre-operatively as a definitive diagnostic procedure for biliary tract strictures and polyps.

Bile Duct Diseases↗
PubMed1989

Hepatic transcatheter arterial embolization with gastroduodenal artery blocking by finger compression.

Hepatic transcatheter arterial embolization was performed in two patients by blocking the gastroduodenal artery with finger compression on the abdominal surface. The embolizing material, which was injected into the common hepatic artery, did not enter the gastroduodenal artery. No postoperative complications were experienced. This method may be useful for patients in whom superselective catheterization of the proper hepatic artery is not feasible.

Angiography↗
PubMed1989

Visualization of coronary blood flow by color Doppler imaging with a transesophageal approach.

To examine whether CBF can be imaged by color Doppler technique, we visualized CBF using a transesophageal color Doppler imaging system. In 36 of 39 patients with normal coronary arteriograms after heart surgery, the LMT and the proximal LAD were clearly imaged by 2-dimensional echocardiography. Among them, CBF was coded mainly in blue in 32 patients, showing that the flow runs from proximal to distal. In some cases, yellowish and/or reddish components were seen, suggesting the occurrence of aliasing associated with augmentation of flow velocity or flow turbulence. The fast Fourier transformation spectrogram of the pulsed Doppler sampled in the colored flow showed a typical flow velocity pattern of the LAD, which mainly consisted of a predominantly diastolic component. These results indicate that the transesophageal color Doppler technique is advantageous in noninvasively imaging CBF. It should be further sought whether flow abnormality due to coronary stenosis could be determined by this technique.

Adult↗
PubMed1989

[Studies on cholangiographic and endoscopic findings of primary intrahepatic cholesterol stones].

Cholangiographic investigations in 16 patients with primary intrahepatic cholesterol stones yielded some characteristic findings as follows. 1. Several numbers of stones were filled within locally dilated portion of the subsegmental or more peripheral intrahepatic bile duct branches, with no or minimal dilatation of the more peripheral portion and no stenosis-like lesions of the more hilar portion. 2. The lesion was single or multiple scattered in the liver and intrahepatic cholangiogram excluding involved segments was almost normal. 3. Although extrahepatic bile duct and/or gallbladder stones were often associated, the normal gallbladder, cystic duct and papillary portion and slightly dilated common bile duct were demonstrated. These cholangiographic findings were compatible with the endoscopic findings that inflammatory changes of the bile duct were rarely observed. According to above mentioned findings, it is suggested that the etiology of this disease differs from intrahepatic stones of calcium bilirubinate and dissolution therapy with bile acid may be available.

Adult↗
PubMed1989

[Significance of disturbances of cardiac filling in constrictive pericarditis].

Using pulsed Doppler echocardiography, blood filling patterns of the right atrium and left and right ventricles in constrictive pericarditis were studied to evaluate the physiological role of the pericardium in the hemodynamics of this disease. Thirteen cases were examined including five cases with atrial fibrillation. The control subjects consisted of 16 healthy persons and six cases of lone atrial fibrillation. 1. Peak velocity of the atrial filling wave during ventricular systole was reduced, and the filling time was shortened, suggesting reduced compliance and restricted motion of the atrial wall, because of the thickening and adhesions of the pericardium. Duration of the atrial filling wave during ventricular diastole was also shortened, reflecting disturbance of the early diastolic filling of the right ventricle. 2. In healthy subjects, duration of the rapid filling wave was longer in the right ventricle than in the left ventricle, probably due to the greater compliance of the right ventricular wall as compared to that of the left ventricular wall. In constrictive pericarditis, the rapid filling time of the right ventricle is shortened, so that the difference in this time between the right and left ventricles is minimized, which may be related to a thinner right ventricular wall. Duration of the rapid filling wave of the right ventricle correlated with right ventricular end-diastolic pressure, indicating that the duration of the right ventricular rapid filling wave is proportional to the severity of constrictive pericarditis. In conclusion, constriction of the pericardium definitely influences the hemodynamics of the right side of the heart more than it does the left side in constrictive pericarditis. This difference appears to result from the difference in thickness of the myocardial layers of both ventricles.

Adult↗
PubMed1989

Gastrinoma in a mesenteric lymph node.

A 36-yr-old man was admitted to our hospital complaining of severe vomiting and diarrhea. Upper gastrointestinal series showed deformity of the duodenum. Serum gastrin level was very high (1,829 pg/ml) and secretin provocative test presented a positive result (peak 4,535 pg/ml). We diagnosed his illness as Zollinger-Ellison syndrome, but failed to identify the site of tumor. His symptoms were controlled with cimetidine 1,600 mg qid, but serum gastrin level was increasing. A year after the first admission, computed tomographic scan and selective angiography demonstrated the tumor, and surgery was performed. A solitary 2-cm tumor was noted at the surface of mesenterium of the duodenum. Frozen and paraffin section of the tumor revealed islet cell tumor apparently within a lymph node. Immunohistological examination revealed positive staining for gastrin alone. No other tumors were detectable by inspection and palpation during the operation. After excision of the tumor, serum gastrin and secretion test were normalized, and the patient remains asymptomatic 1 yr after surgery.

Adult↗
PubMed1989

[Analysis of pancreatic enzymes in the bile of congenital choledochal cyst with anomalous pancreaticobiliary ductal union].

Pancreatic enzymes in the bile of congenital choledochal cyst with anomalous pancreaticobiliary ductal union were analyzed. Almost all pancreatic proteases were already activated in the bile aspirated immediately after insertion of PTCD tube. However, inactive proteases gradually increased after continuation of drainage by PTCD. Pancreatic protease activities appeared again after clamping the PTCD tube. In vitro study of trypsin activities in the bile containing no initial trypsin activity, active type of trypsin did not appear throughout the experimental period. It is suggested that continuous reflux of pancreatic juice into the bile and certain incubation time are necessary for activation of pancreatic protease in bile of congenital choledochal cyst.

Adult↗
PubMed1989

[A study of concomitant chronic pancreatitis in forty-one cases of adult congenital biliary dilatation].

Forty-one cases of adult congenital biliary dilatation (CBD) were studied for concomitant chronic pancreatitis. Of the 41 cases, 8 had had such previous operations as choledochojejunostomy or choledocho-duodenostomy without biliary diversion (reoperated cases) and the other 33 had not received previous operations (primary cases). All of the 36 cases whose type of pancreatico-biliary junction could be examined revealed anomalous pancreatico-biliary junction. Four cases (10%) of CBD (1 of the primary and 3 of the reoperated cases) were complicated by chronic pancreatitis. On examining the elapsed time between the first and the final operation of the reoperated cases, in the 5 cases whose periods were less than 13 years, none was complicated by chronic pancreatitis. On the contrary, in the 3 cases whose periods of time were more than 17 years, all were complicated by chronic pancreatitis. The results suggest that choledochoenterostomy without biliary diversion enhances pancreatic damage in cases with anomalous pancreatico-biliary junction.

Adolescent↗