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Biomedical subjects

Y Nimura

Publications and source records attributed to Y Nimura.

At least 145 records · Page 8Linked to original sources
PubMed1987

[Effect of brain death on hemodynamics and cardiac function: an experimental study].

An experimental model was designed to study hemodynamic and left ventricular functional changes in the course of and after brain death in 13 mongrel dogs. Brain death was induced by creating intracranial hypertension by inflating a balloon inserted into the subdural space. Hemodynamic parameters and left ventricular systolic function as assessed by echocardiography were measured before and during intracranial hypertension and 30 min and 1, 2, 3, 5 and 8 hrs after brain death. During intracranial hypertension, heart rate, systemic and pulmonary blood pressures, cardiac output and systemic vascular resistance raised significantly. After brain death, all parameters decreased rapidly and significantly, and then stabilized. On comparison with values obtained before intracranial hypertension, systemic blood pressure decreased markedly following brain death, while no marked change was noted in cardiac output. This result is attributable to a marked reduction in peripheral vascular resistance following the induction of intracranial hypertension. The left ventricular end-diastolic and end-systolic diameters did not change; consequently, fractional shortening did not change, either. The Weissler's index improved after brain death, reflecting a marked reduction in systemic vascular resistance. This indicates limited usefulness of afterload-dependent cardiac indices. At the agonal period of brain death, three of 13 dogs died because of ventricular fibrillation or a marked decline in systemic blood pressure. Within five to eight hours after brain death, seven dogs died because of intractable acidosis. These results represent the specific hemodynamic features occurring after brain death. It is thought that recognition of these features is useful in managing cases of brain death and in selecting donors for heart transplants.

Animals↗
PubMed1987

Predominance of prostaglandin D2 and I2 in the rat gastric mucosa--analysis by high-performance liquid chromatography.

We have developed a method for measuring prostaglandins (PGs) in rat gastric mucosa by high-performance liquid chromatography (HPLC). The levels of PGD2 and 6-keto-PGF1 alpha, a degradation product of PGI2, were five times higher than those of PGE2 and PGF2 alpha. Oral administration of indomethacin (6 mg/kg body weight) completely abolished the synthesis of all detectable PGs uniformly. These results suggest that endogenous PGs, especially PGD2 and I2, play some roles in the function of the gastric mucosa.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

[A case of polypoid carcinoma of the left hepatic duct].

A case of polypoid carcinoma of the left hepatic duct in 50-year-old male was reported. Extended left hepatic lobectomy with total caudate lobectomy and resection of the right hepatic duct were performed because the tumor involved the right hepatic duct and bile duct branches of caudate lobe, medial and lateral segment. Papillary growth of the tumor was diagnosed definitely by percutaneous transhepatic cholangioscopy (PTCS) and computed tomography. The tumor infiltrated the liver parenchyma of medial segment and compressed the middle hepatic vein. These findings were revealed by selective middle hepatic venography preoperatively.

Adenocarcinoma↗
PubMed1987

[Anatomical studies on the biliary tree of the caudate lobe using an endoscopic retrograde cholangiogram].

The purpose of this study is to clarify positional relationship between the bile duct of the caudate lobe and the bile duct of the hepatic hilum through endoscopic retrograde cholangiogram (ERC). Until December 1984 all 100 ERC that met the following three conditions were studied which at Yachio Hospital. 1. The first cholangiogram. 2. Without obstructive jaundice. 3. No existence of lesion at the hepatic hilum. Bile duct of the caudate lobe were classified into 4 separate types: 1) Ducts from the cranialis of the right caudate lobe which pass via the inferior vena cava to the hepatic hilum named Blr, were confirmed in 32. 2) Ducts from the cranialis of the left caudate lobe to the hepatic hilum named Bl l s, were confirmed in 19. 3) Ducts from the left lateral part of the left caudate lobe to the hepatic hilum named Bl l i were confirmed in 37. 4) Ducts from the caudate process to the hepatic hilum named Blc, were confirmed in 5. One or more of the above bile ducts were confirmed in 53 cases. All four of the above were confirmed in only 2 cases out of 53 cases. Three were confirmed in 7 out of 53 cases, two were confirmed in 20 cases out of 53 cases and one was confirmed in 24 out of 53 cases. Studies for the bile duct of the caudate lobe have been conducted anatomically, but there has been no research by clinical examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile Ducts, Intrahepatic↗
PubMed1986

Paradoxical elevations of plasma glucagon levels in patients after pancreatectomy or gastrectomy.

In twenty-five patients undergoing total pancreatectomy (TP), twenty distal gastrectomy (DG) and twenty healthy subjects, effects of oral glucose loading on the plasma glucagon (IRG) levels were determined. Plasma IRG levels were elevated after glucose loading in the TP and DG patients, but not in the healthy subjects. To clarify events related to the elevations in IRG, the plasma IRG components were analyzed by gel filtration in 6 of the TP patients, 5 of the DG patients and 4 of the controls. In the TP group, IRG3500 was not detectable either in the basal state or after glucose loading, while IRG9000 was markedly increased after glucose (p less than 0.002). In the DG group, IRG3500 was significantly suppressed after glucose (p less than 0.05), but IRG9000 was clearly increased (p less than 0.005). In the controls, IRG3500 was suppressed after glucose (p less than 0.05), however, IRG9000 was not detected throughout the examination. Thus, in patients with TP or DG, the essential cause of the high responses of plasma glucagon after oral glucose loading was the increase in IRG9000. Because the food passage route is much the same in TP and DG patients, the IRG9000 elevations are probably related to secretion in the digestive tract.

Adult↗
PubMed1986

Semiquantitative grading of severity of mitral regurgitation by real-time two-dimensional Doppler flow imaging technique.

An attempt was made to determine whether mitral regurgitation could be detected and its severity evaluated semiquantitatively by newly developed real-time two-dimensional Doppler flow imaging in 109 patients who underwent left ventriculography. In the Doppler flow imaging technique, Doppler signals due to blood flow in the cardiac chambers are processed using a high speed autocorrelation technique, so that the direction, velocity and turbulence of the intracardiac blood flow are displayed in the color-coded mode on the monochrome B-mode echocardiogram in real time. Mitral regurgitant flow was imaged as a jet spurting out from the mitral valve orifice into the left atrial cavity. It was noted that the regurgitant jet in the left atrial cavity had a variety of orientations and dynamic features when studied by the present technique. The sensitivity of the technique in the detection of mitral regurgitation was 86% as compared with that of left ventriculography. Mitral regurgitation in the false negative cases was mostly mild. On the basis of the farthest distance reached by the regurgitant flow signal from the mitral valve orifice, the severity of regurgitation was graded on a four point scale and these results were compared with those of angiography. A significant correlation (r = 0.87) was found between Doppler imaging and angiography in the evaluation of the severity of mitral regurgitation. A similar result was obtained for the evaluation based on the area covered by the regurgitant signals in the left atrial cavity. Thus, noninvasive semiquantitative evaluation by real-time two-dimensional Doppler flow imaging appears to be a promising clinical technique.

Adolescent↗
PubMed1986

Diagnosis of mitral valve perforation by real-time two-dimensional Doppler flow imaging technique.

It has been difficult to diagnose mitral regurgitation due to valve perforation using either noninvasive or invasive methods, differentiating it from that resulting from incomplete coaptation of the mitral valve. This report describes three patients with infective endocarditis and mitral valve perforation, which was definitively diagnosed by the real-time two-dimensional Doppler flow imaging technique. In these three patients, B-mode echocardiography demonstrated an echo interruption on the anterior mitral leaflet. However, it was not certain whether this interruption was simply an echo dropout or indicated an interruption of the valve tissue. Doppler flow imaging then demonstrated unusual flow in the vicinity of the echo interruption, which appeared to flow from the left ventricular cavity into the left atrial cavity across the midportion of the anterior mitral valve leaflet during systole and in the opposite direction during diastole. This was interpreted as mitral valve perforation. In general, Doppler flow imaging may play a complementary role with B-mode echocardiography in cardiac diagnosis.

Adult↗
PubMed1986

Right atrial flow topography in healthy subjects studied with real-time two-dimensional Doppler flow imaging technique.

The pattern of normal blood flow in the right atrial cavity was studied using the newly developed real-time two-dimensional Doppler flow imaging technique as a standard reference for the Doppler diagnosis of heart diseases with intracardiac shunts at the atrial level. The study was performed primarily with use of the apical four chamber and the parasternal right ventricular inflow tract views in 21 healthy subjects. The following patterns were observed: blood from the inferior vena cava flowed up along the posterior wall of the right atrium and joined with blood from the superior vena cava in the posterocranial part of the right atrial cavity; the flow then coursed along the roof of the right atrium toward the tricuspid valve in the atrial relaxation phase. This flow was always noted along the interatrial septum in the four chamber view. During and after mid-systole of the right ventricle, additional blood flow away from the tricuspid valve appeared, moving from the valve to the central part of the right atrial cavity, that is, at the lower right of the preceding inflow; this flow was interpreted as arising from eddy currents caused by the preceding inflow. In early diastole of the right ventricle, the flow signal area along the interatrial septum and the roof of the right atrium extended into the right ventricular cavity through the tricuspid valve. In the atrial contraction phase only the blood near the tricuspid valve in the right atrial cavity appeared to flow into the right ventricular cavity. Inflow from the coronary sinus was almost undetectable.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Glycosphingolipid composition of a renal cell line (MDCK) and its ouabain-resistant mutant.

Glycosphingolipids were isolated from a canine kidney cell line (MDCK) and its ouabain-resistant mutant (MDCK-OR) by solvent extraction, mild alkaline methanolysis, a DEAE-Sephadex column, and preparative TLC. The glycolipids were characterized by their mobilities on TLC, an analysis of carbohydrates as trimethylsilyl methyl glycosides and acetates of partially methylated alditols, as well as by treatment with specific glycosidases. In the neutral glycolipid fraction of both cell lines, galactosylceramide (GalCer), glucosylceramide (GlcCer), lactosylceramide (LacCer), digalactosylceramide (Ga2Cer), globotriaosylceramide (Gb3Cer), globoside (Gb4Cer), and the Forssman antigen (IV3GalNAc alpha-Gb4Cer) were identified. The contents of Ga2Cer (4.4 nmol/mg protein), Gb3Cer (0.6), Gb4Cer (2.9), and IV3GalNac alpha-Gb4Cer (19.5) in MDCK-OR were 1.4- to 2.1-fold higher than those in MDCK, while the concentrations of GlcCer (5.3) and LacCer (1.4) in MDCK-OR were about half of those in MDCK. Among acidic glycolipids of MDCK-OR, galactosyl sulfatide (GalCer-I3-sulfate) and lactosyl sulfatide (LacCer-II3-sulfate) were increased to 1.9 (2.7-fold) and 0.2 nmol/mg protein (2.0-fold), respectively, as compared to MDCK. However, N-acetylneuraminosyllactosylceramide (GM3), the predominant ganglioside in both cell lines, was decreased to about one third of the level (1.5 nmol/mg protein) in the parent MDCK (4.7 nmol/mg protein). The fatty acid of the glycolipids in both cell lines consisted mainly of saturated acids of 16, 18, 22, and 24 carbons.

Animals↗
PubMed1986

Primary failure of Hancock porcine bioprosthetic valves: two dimensional echocardiographic assessment.

To reveal the process of primary failure of the Hancock porcine bioprosthetic heart valve, a real-time two-dimensional echocardiography was undertaken. There were 75 cases (84 valves) with 26 in the aortic valve position, 39 in the mitral valve position, 9 in both the aortic and mitral valve positions, and 1 in the tricuspid valve position. The subjects comprised 35 males and 40 females, whose ages ranged from 18 to 65 years with a mean of 44.7 years. Valvular changes such as thickened valve cusps or abnormal valve movement were observed in 27 (32%) of the 84 valves; more specifically, in 5 (14.3%) of the 35 aortic valves and in 22 (45.8%) of the 48 mitral valves, indicating that valvular changes occurred most frequently in the mitral valve position (p less than 0.01). In the period between valve replacement surgery and the appearance of valvular changes, no significant difference was noted between aortic and mitral valve bioprostheses. The duration ranged from 14.5 to 74.5 months with a mean of 50.2 months. Valvular changes were evident in more than 50% of the valve bioprostheses implanted 6 or more years ago. In the mitral valve position, valve cusp changes appeared more frequently at the anterior cusp than at the inner and outer cusps. The frequency was 17 cases at the anterior cusp, 6 at the inner and 9 at the outer. In 7 of the 11 cases followed up after the appearance of valvular changes, an increase in the changes was recognized 7.5 to 29.5 months (a mean of 16.4 months) later.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

[Postural effects in the jugular phlebogram in patients with complete absence of the left pericardium].

To elucidate the function of the pericardium, alterations in jugular phlebograms, intracardiac pressures and cardiac volumes induced by postural changes were examined in seven patients with complete absence of the left pericardium. Ten patients with ischemic heart disease were studied as controls. Jugular phlebograms in patients with complete absence of the left pericardium showed decreased depths of the x descent and the tall v waves followed by the deep y descents (M-shaped pattern) in the supine position. These jugular abnormalities were exaggerated in the left lateral decubitus position. By contrast, the jugular phlebograms tended to return to normal, but remained abnormal in the right lateral decubitus position. Right atrial pressure curves showed similar postural effects. However, the jugular phlebograms and right atrial pressure curves in patients with ischemic heart disease were not altered by postural changes. The characteristic alterations of the jugular phlebograms are useful indicators for diagnosing complete absence of the left pericardium. The lack of a prompt decrease in pericardial pressure during ventricular ejection due to the absence of the pericardium is one of the causes of a decreased depth of the x descent in pericardial defect. However, this cannot explain the postural alteration of the jugular phlebogram. Another possible mechanism is the decreased excursion of the tricuspid ring during systole. As indicated in our previous report, there is anterior movement of the cardiac apex during systole in cases of pericardial defect, which is exaggerated in the left lateral decubitus position and decreased in the right lateral decubitus position due to the lack of normal pericardial support. This anterior swinging motion may inhibit the descent of the tricuspid ring toward the apex, resulting in a decreased depth of the x descent of the jugular phlebogram and the right atrial pressure curve and their postural alterations. The right ventricular volume as calculated from cardiac computerized tomography and the right ventricular end-diastolic pressure were not altered significantly by postural changes in the control cases. These indices increased to a greater extent in the left lateral decubitus position than in other postures in cases with pericardial defects.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

[Management of left and right type intrahepatic stone associated with proximal bile duct stenosis].

Fifty-seven cases of intrahepatic stone were treated in our department from 1976 to 1984. Fifteen cases out of them were left and right type intrahepatic stone associated with the proximal bile duct stenosis. Treatments and results of these 15 cases are discussed. Percutaneous Transhepatic Cholangioscopy (PTCS) was performed in 10 cases, post operative cholangioscopy (POC) in 7 cases. These cases were divided into three groups according to the treatment received. Six patients were treated only with cholangioscopic lithotomy (Group I). Six patients underwent surgical treatment after cholangioscopic lithotomy (Group II). Other 3 patients were treated with POC (Group III). Clinical course of Group I: One patient died of recurrent liver abscess 5 years after PTCS. One died of another disease. One had suffered from empyema 5 years after PTCS, but he is doing well now. Other 3 patients are doing well now. Clinical course of Group II: All patients are doing well now. Clinical course of Group III: All patients underwent treatments for residual stones after POC. Good results were obtained in group II. Surgical treatment after cholangioscopic lithotomy is the best way for these 15 cases. Adequate operative procedure should be applied after improving the patients' condition and making an accurate diagnosis of biliary tract anomalies by means of PTCS.

Adolescent↗
PubMed1986

[Reevaluation of the surgical treatment of thyroid nodules diagnosed as cancer postoperatively].

Reevaluation was carried out on the surgical treatment for clinically benign thyroid nodules. One hundred and thirty-seven patients underwent conservative resections of the thyroid because of preoperative impression of benign nodules at the First Department of Surgery, Nagoya University Hospital from 1970 to 1984. Permanent paraffin sections of the resected specimen revealed that the nodules in 4 patients were intrathyroidal cancer (3 papillary and 1 follicular) and the nodules in the other 8 patients were associated with an unsuspected small (3 approximately 15 mm) thyroid cancer. All those patients underwent either lobectomy or subtotal thyroidectomy at the initial surgery except for one patient in whom enucleation was performed. No further intervention was carried out when the definitive diagnosis was made, except for one patient in whom the enucleation was followed by lobectomy. No neck dissection was attempted in all of them. Patients have been living and well without evidence of recurrence for 3 to 11 years and one died of unrelated disease. From these results, it is recommended that lobectomy is the least requirement in treating clinically benign nodule and that, when paraffin section reveals the tumor is intrathyroidal cancer, no further surgery is justified unless there are other foci of cancer in the resected lobe.

Adenocarcinoma↗