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Biomedical subjects

Y Nimura

Publications and source records attributed to Y Nimura.

At least 91 records · Page 5Linked to original sources
PubMed1988

Doppler echocardiographic approach to the blood flow of the left anterior descending coronary artery.

Assessment of flow in the left anterior descending coronary artery by Doppler echocardiography appeared to be possible in some patients in which the coronary artery system might be wide and/or the displacement of the coronary artery might be reduced because of cardiac enlargement or of impaired cardiac function. A study of this possibility was carried out in 78 patients, 20 cases with hypertrophic cardiomyopathy, 10 with dilated cardiomyopathy, 20 with aortic valve disease, and 28 following valve replacement for aortic valve disease. The anterior interventricular sulcus was a helpful landmark to search for the left anterior descending artery. The characteristic feature of the coronary flow pattern, that the flow ran mainly during diastole, was also helpful in finding the coronary artery. Complementary roles of ultrasonic imaging and Doppler ultrasound evaluation should be emphasized for identifying a thin echo-free space in the sulcus as the coronary artery. The left anterior descending coronary artery was imaged in 26 of the 78 patients. The peak velocity ranged 24 cm/s to 75 cm/s in different patients. Because the present study was carried out in patients with some particular diseases, these results do not indicate that current techniques can be routinely used for assessing the coronary flow. The detection rate will be increased with improvements in image resolution and the Doppler sensitivity. Although the detection rate of the coronary artery was not satisfactory in the present stage, the effect of sublingual administration of nitroglycerin on coronary circulation was noninvasively assessed in some patients, where reduction of the flow velocity by about 27% was observed in real time.

Adolescent↗
PubMed1988

Value of percutaneous transhepatic cholangioscopy (PTCS).

Since July 1975, percutaneous transhepatic biliary drainage (PTBD) has been performed in 533 cases, and since April 1977 we have developed percutaneous transhepatic cholangioscopy (PTCS) as a diagnostic and therapeutic endoscopical tool in 198 cases of malignant disease and 195 benign cases. After dilating the sinus tract of PTBD using a 15-Fr catheter about 2 weeks after PTBD, PTCS was carried out through the sinus tract. PTCS has diagnostic advantages: the lesion can be accurately diagnosed histologically and the extent of cancer in the biliary tract can be assessed by taking biopsy specimens before the operation. PTCS has been applied for cholangioscopic lithotripsy in 145 cases of gallstone disease. In 44 cases, the Nd-YAG laser and/or electrohydraulic shock wave has been used to break up the stones. The PTCS morbidity was 6% and mortality was 0.3%.

Biliary Tract Diseases↗
PubMed1988

Feedback regulation of basal pancreatic secretion in humans.

The effect of intrajejunal infusion of pancreatic juice on basal pancreatic secretion was studied in patients who had received pancreatoduodenectomy for pancreatic, biliary, or duodenal malignancy. Pure pancreatic juice was obtained through a drainage tube inserted into the main pancreatic duct. There was little fibrosis in the pancreatic remnant and daily pancreatic juice output was more than 200 ml. After intraluminal infusion of pancreatic juice, water, protein, bicarbonate, and enzyme outputs were decreased significantly by about 30%. Intraluminal trypsin also reduced pancreatic secretion. Trypsin inhibitor (aprotinin) suppressed the significant decrease caused by autopancreatic juice or trypsin solution. We conclude that basal pancreatic secretion in humans is under negative feedback control by intestinal pancreatic juice or tryptic activity.

Adult↗
PubMed1988

Clinical implications of pulmonary regurgitation in healthy individuals: detection by cross sectional pulsed Doppler echocardiography.

Pulsed Doppler echocardiography in healthy individuals often shows a disturbance of diastolic flow in the right ventricular outflow tract just below the pulmonary valve that suggests regurgitation. This disturbance of diastolic flow was studied in 50 healthy individuals and 40 patients with cardiopulmonary disease, some of whom had a pulmonary regurgitant murmur. Diastolic flow was disturbed in 39 of the 50 healthy individuals. In 32, cross sectional echocardiography gave a satisfactory image of the pulmonary valve. The characteristic Doppler signals usually lasted throughout diastole, were directed toward the right ventricular cavity, and gradually waned towards end diastole; they formed a spindle shaped area of abnormal signals that extended to within 10 mm of the coaptation of the pulmonary valve towards the right ventricular cavity and the pressure difference estimated from the signals by the modified Bernoulli equation seemed to be proportional to the normal retrograde transpulmonary pressure difference. In all 40 patients with cardiopulmonary disease, signals indicating pulmonary regurgitation were found whether or not a regurgitant murmur was present. When it was present, however, the spindle was longer than 20 mm and in patients with pulmonary hypertension the velocity of abnormal diastolic flow was higher than in healthy individuals. The Doppler signals registering disturbed flow in the healthy individuals resembled the signals caused by pulmonary regurgitation in the patients in terms of location, orientation, and configuration. These results show that healthy individuals usually have trivial pulmonary regurgitation. In practice the distance that the flow disturbance extends from the valve and estimated pressure difference across the valve are probably the most important variables for assessing the clinical significance of pulmonary valve regurgitation.

Adult↗
PubMed1988

Transient abnormal septal motion after non-surgical closure of the ductus arteriosus.

Abnormal septal motion on M mode echocardiography was seen in eight of 16 patients soon after non-surgical closure of the ductus arteriosus. Ten to twenty-nine months after the procedure the abnormal septal motion had disappeared spontaneously. The cross section of the left ventricular cavity was circular both when septal motion was abnormal and when it was normal. Cross sectional echocardiography showed that there was an exaggerated anterior swinging motion of the heart in systole in patients with abnormal septal motion on the M mode recordings. The left ventricular end diastolic diameter before closure was significantly larger, and its reduction after closure was more pronounced in those with abnormal septal motion than in those without. This suggested that the abnormal septal motion was associated with relief of long standing left ventricular volume overload. It is suggested that acute shrinkage of the heart caused temporary laxity of the pericardium, and consequently more movement of the heart within the thorax. The return of normal septal motion suggests that the pericardium gradually shrank to accommodate the smaller heart.

Adult↗
PubMed1988

Abnormal blood pathways in left ventricular cavity in acute myocardial infarction. Experimental observations with special reference to regional wall motion abnormality and hemostasis.

To elucidate the mechanism of regional hemostasis in the left ventricular (LV) cavity during myocardial infarction, the blood pathway in LV cavity was examined with contrast echocardiography injected from the left atrium before and after coronary ligation in nine canines. Before coronary ligation, contrast echoes spread over LV cavity with one rush. After ligation, smokelike echoes indicating hemostasis were observed at the apical middle of the LV cavity in five dogs with apical akinesis and at the apical area in four dogs with apical dyskinesis. The contrast echoes did not reach the apex within one diastolic period but turned upward to the outflow tract in the middle of the cavity in all dogs. In the cardiac beats that followed, some contrast echoes spread slowly toward the apex, forming a thin layer along the posterior wall in cases with akinesis but not in cases with dyskinesis. The area separated from the blood pathway developed where the smokelike echoes had been developed. Tachycardia exaggerated the abnormality of blood pathway and widened the contrast echo-free area. The abnormal pathway of the blood in apical myocardial infarction develops hemostasis in the apex. This should be one of the mechanisms of thrombus formation in myocardial infarction.

Animals↗
PubMed1988

[Diagnostic value of computed tomography for the detection of invasion of the caudate bile duct branch in carcinoma of the hepatic hilum].

The visualization of the caudate bile duct branch (B1) in computed tomography (CT-scan) with a high dose of contrast medium was evaluated in 71 patients with carcinoma of the liver, biliary tract and pancreas, preoperatively. The patients were classified into four groups: Group A, 22 patients (twelve hepatomas, six gall bladder cancers and four cancers of the pancreas body or tail) without abnormal findings in the biliary tract; Group B, two patients (cancer of the pancreas head and the common bile duct) with obstructive jaundice whose CT-scans were taken before percutaneous transhepatic cholangio-drainage (PTCD); Group C, 22 patients (16 cancers of the pancreas head and six common bile duct cancers) whose CT-scans were taken after release of jaundice by PTCD; Group D, 25 patients with carcinoma of the hepatic hilum whose CT-scans were taken after release of jaundice by PTCD. The results were as follows. 1) In Group A, B1 was invisible in all the patients. 2) In Group B, B1 was clearly visible in all the patients. But in Group C, B1 was visible only in one patient. 3) In Group D, B1 was visible in 19 out of 25 patients and in 18 patients out of these 19 patients, cancer invasion toward B1 was histopathologically confirmed. In contrast, invasion was revealed only in one out of six patients whose B1s were invisible. From these results, it is concluded that in carcinoma of the hepatic hilum the visualization of B1 in CT-scan after release of jaundice by PTCD strongly suggests the cancer invasion on B1, and requests the caudate lobe resection.

Aged↗
PubMed1988

[Influence of total pancreatectomy on the secretion of human growth hormone and the endocrine pancreas].

To evaluate the effect of total pancreatectomy on the secretion of human growth hormone, twenty-six patients undergoing total pancreatectomy and twelve healthy subjects (controls) were investigated. Blood glucose (BG), plasma insulin (IRI), C-peptide (CPR), immunoreactive glucagon (IRG) and human growth hormone (HGH) levels were determined. In the glucose tolerance test, the mean basal blood glucose level in the patients before operation was significantly higher than the level in the controls. The basal blood glucose level in the patients after operation was still higher than the level before operation. The responses of IRI, CPR, and IRG secretion after arginine infusion in the patients before operation were less than those in the controls. After operation, arginine infusion did not alter the levels of IRI, CPR and IRG. The mean basal HGH levels were not significantly different between the controls and the patients before and after operation. However, a statistically significant correlation was shown between the basal values of plasma HGH and those of plasma IRI in the patients after operation. Thus, it suggested that the basal secretion of HGH is closely related to the exogenous plasma insulin levels in the pancreatectomized patients. After arginine infusion, the HGH levels in the patients before operation were lower than the those in the controls, but insignificant. After operation, mean HGH levels were significantly lower than those before operation. These findings suggested the absence of pancreatic endocrine function caused by total pancreatectomy resulted in decreased responses of HGH secretion after arginine infusion.

Adult↗
PubMed1988

[A case of advanced gallbladder carcinoma of a 77-year-old female successfully resected with extended right hepatic lobectomy with caudate lobectomy and pancreatoduodenectomy].

A 77-year-old woman was admitted with obstructive jaundice. US and CT demonstrated a solid mass 2.5cm in diameter in the hepatic hilum. Cholangiography revealed not only severe stenosis of the hilar hepatic duct but also involvement of the right-posterior-inferior-ventral branch and right caudal branch. Angiography showed almost normal appearance except cystic artery. Duodenal invasion was also detected by per oral duodenography. These findings forced to plan extended right hepatic lobectomy with caudate lobectomy and pancreatoduodenectomy for radicality. In spite of the aged and her complications such as DM, hypertension, scoliosis and bradyacusia, liver function was good and she was mentally very active for life. Therefore, planned operation was performed and the suitability of this operation was proved by histological examination. She underwent resection of the abdominal wall for recurrence 8 months after and now alive without the disease 27 months after the first operation. It is stressed that the most suitable operation should be selected conceiving the mode and severity of cancer extension which is revealed by precise preoperative examinations and extended operation may be indicated in even the elderly if various conditions are good.

Adenocarcinoma↗
PubMed1988

[Experimental studies on fistula formation after percutaneous trans-hepatic cholangiodrainage].

The process of intra- and extra-hepatic fistula formation after percutaneous transhepatic cholangiodrainage (PTCD) was investigated. Furthermore, effects of such 4 materials of catheter as vinyl chloride, silicon, polyethylene and poly-urethane on this formation process were compared in order to clarify factors influencing the process. Fistula formation began 2 weeks after PTCD, and nearly completed after 4 weeks. A drainage fistula most markedly formed in the use of vinyl chloride, as the fistula wall was thick and its collagen fibers were microscopically observed to be dense and regularly arranged. On the other hand, fistula walls were thin, and their connective tissues consisted of immature cells and sporadically observed, when the other materials were used. However, degeneration of the liver cells around the intrahepatic fistula was most markedly seen in the use of vinyl chloride. In addition, the fistula formation tended to be more facilitated at early stage when the extrahepatic bile duct was occluded. These results suggested that vinyl chloride is the most suitable material if the drainage is applied for the fistula formation.

Animals↗
PubMed1988

[Anterolateral papillary muscle motion before and after septal myotomy in hypertrophic obstructive cardiomyopathy].

The left ventricular outflow pressure gradient in hypertrophic cardiomyopathy results from systolic anterior motion of the mitral valve (SAM). This abnormal orientation of the valve was previously proposed to be caused by inappropriately hypertrophied papillary muscles which protrude to the interventricular septum (IVS). Septal myotomy can alter the orientation of the papillary muscles and resolve the pressure gradient, without myectomy. Recently, we have experienced two instructive cases to prove our previously advocated hypothesis. Case 1: This 54-year-old man complained of effort dyspnea, and his echocardiogram disclosed marked SAM, and a thickened IVS (28 mm) and left ventricular posterior wall (16 mm). The intraventricular pressure gradient was 134 mmHg, and there was mitral regurgitation of grade 2/4. A longitudinal incision via the aorta on the anterior portion of the IVS, toward the base of the anterolateral papillary muscle, resolved the pressure gradient and mitral regurgitation, and two-dimensional echocardiography demonstrated that the SAM resolved at the lateral aspect of the valve, but it remained on the medial side. Case 2: This 57-year-old man complained of dyspnea during effort. He had marked SAM. The intraventricular pressure gradient was 65 mmHg, and there was grade 3/4 mitral regurgitation. Longitudinal incisions on the anterior, medial and posterior parts of the IVS abolished the SAM and reduced mitral regurgitation to grade 1/4. In both cases, during systole, the anterolateral papillary muscle protruded into the left ventricular ontflow tract, causing SAM. After surgery, the direction of the muscle axis moved toward the mitral orifice during systole, resulting in alleviation of SAM on the same side of the location of septotomy. This further confirmed our concept that disoriented papillary muscles play essential roles in causing SAM. If the Venturi forces previously stressed by other investigators cause SAM, the latter should resolve on both the medial and lateral aspects, even by septotomy. Thus, the Venturi theory seems untenable.

Cardiomyopathy, Hypertrophic↗
PubMed1988

[A case of primary intrahepatic cholesterol gallstones difficult to manage by percutaneous transhepatic cholangioscopy].

A case of a 60-year-old man with primary intrahepatic cholesterol gallstone was reported. Several stones, each size 3mm in diameter, were packed in the diverticulum-like dilated part of the posterior-inferior-ventral bile duct branch of the right lobe and 3 stones, each size 3-4mm in diameter, were scattered separately in the lateral segment of the left lobe of which the bile duct branches were diffusely tortuous and with mildly irregular dilatation. Morphologic appearance of the biliary system except in these 2 areas was normal. All stones including a large gallbladder stone consisted of cholesterol. Intraluminal approach, not only ERC but also PTCS, can hardly detect intrahepatic stones of more peripheral areas, although combination of US and enhanced CT may be useful even though bile duct branches are not dilated. We failed in PTCS lithotomy in this case for the first time in our experience with more than seventy cases of intrahepatic stones. However, by PTCS it was possible to investigate the morphology of the biliary system in detail and consequently, to make the diagnosis of primary intrahepatic stones. This patient has cured by cholecystectomy and minimum hepatectomy.

Bile Ducts, Intrahepatic↗
PubMed1988

[Studies on the radiographic anatomy of the biliary tree of the caudate lobe].

The cholangiograms obtained through percutaneous transhepatic cholangioscopy (PTCS) were studied for the purpose of clarifying radiographic anatomy of confluence of the bile ducts of the caudate lobe and the main trunks at the hepatic hilum. PTCS was performed on a total of 112 patients at our department, January, 1979 through December, 1984. Among them 60 cases without lesions in the hepatic hilum were used for this study. Four types of the bile duct of the caudate lobe were distinguished by cholangiography in the 60 cases: 1) A duct ran from the cranial portion of the right caudate lobe along the inferior vena cava to the hepatic hilum in 53 (Blr); 2) A duct ran from the cranial portion of the left caudate lobe to the hepatic hilum in 50 (Blls); 3) A duct ran from the left lateral part of the left caudate lobe to the hepatic hilum in 59 (Blli) and 4) A duct from the caudate process to the hepatic hilum in 42 (Blc). We found that cholangiogram following percutaneous transhepatic biliary drainage or selective cholangiogram using the PTCS make an accurate identification of the bile duct of the caudate lobe possible.

Adult↗
PubMed1987

Chronic pancreatitis at early age of onset presenting interesting findings through endoscopic retrograde pancreatography and chemical analysis of nonopaque pancreatic concretion.

This case concerns a 20-year-old male patient with an approximate 10-year history of recurrent and severe abdominal pain radiating to the back. Endoscopic retrograde cholangiopancreatography revealed a short obstructing stenosis of the main pancreatic duct in the head of the pancreas, marked and tortuous dilatation of the prestenotic portion of the main pancreatic duct and its side branches, and a filling defect in the side branch in the body of the gland. Pancreaticojejunostomy was performed to induce decompression of the pancreatic duct. Histology of the pancreas showed advanced chronic pancreatitis. Three nonopaque concretions were obtained at operation. The largest one, which was milky white in appearance and elastic and soft in consistency, proved to be made up of protein. The concretion was rich in acidic amino acids, but poor in basic or aromatic residues. The molar composition of amino acids in the concretion was, in decreasing order, aspartic acid, serine, valine, glycine, and glutamic acid. Powder x-ray diffractometry revealed no crystalline structures.

Adult↗
PubMed1987

Histopathological study of hypertrophic cardiomyopathy with progression to left ventricular dilatation.

The heart of seven cases of fatal congestive heart failure with dilated left ventricle, developing in 5 patients with symptomatic hypertrophic cardiomyopathy (HCM) and 2 patients with histologically widespread disarray of both ventricles, was morphologically investigated. These 7 cases showed myocardial widespread disarray and massive fibrosis, the mean percent area of fibrosis was 40.6% and 59.4% at upper and lower levels of left ventricles, respectively. Fibrosis was most extensive in the lateral wall, and followed by anterior, posterior and interventricular walls. The severity of cell infiltration in left ventricle was completely matched to that of fibrosis and was most extensive in subepicardial area followed by middle and subendocardial areas of left ventricle. The intima and medial thickness of intramural small arteries in the fibrotic areas was significantly larger (p less than 0.05) than that of nonfibrotic areas, which suggested that the effect of intramural small artery was not essential for pathogenesis of massive fibrosis.

Adolescent↗