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Biomedical subjects

R Omoto

Publications and source records attributed to R Omoto.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Serratia marcescens prosthetic mitral valve endocarditis associated with hemolytic anemia].

A 57-year-old female who had been performed mitral valve replacement (MVR) using 31 mm prosthetic valve 32 months before entered the hospital for the evaluation of long standing severe hemolytic anemia without infectious sign. Transesophageal echocardiogram revealed a moderate sized vegetation on the atrial site of the prosthetic valve. The size and number of the vegetation were increased after deterioration of infectious illness. Blood culture grew serratia marcessans and alpha-hemolytic Streptococcus. Re-MVR was carried out with the diagnosis of prosthetic valve endocarditis (PVE). As the symptom of PVE, hemolytic anemia without infectious sign is a rare condition. TEE is an useful method to make diagnosis of PVE by detecting the vegetations and evaluating their change of size and methods and to evaluate the effectiveness of the treatment.

Anemia, Hemolytic↗
PubMed1996

Pravastatin prevents the progression of accelerated coronary artery disease after heart transplantation in a rabbit model.

This study was designed to investigate the effects of pravastatin (Pr) on accelerated coronary arteriosclerosis in transplanted hearts. The rabbit hearts were transplanted to the recipients' neck heterotopically, and received FK506. The rabbits in group 1 were fed a normal diet (ND), and cholesterol-rich diet (CD) in group 2 and 3. Pr (10 mg/kg) was given to group 3. They were sacrificed at 4 weeks and the severity of myocardial rejection and arterio-sclerosis was assessed and scored histologically. The serum lipid levels were significantly elevated by a CD. However, addition of Pr had no effect on the levels of LDL and total cholesterol (TC). There was no significant difference in myocardial rejection in each group. Transplanted hearts in group 2 showed more severe arteriosclerotic lesions than those in group 1. Pr treatment in group 3 diminished the severity of coronary arteriosclerosis. Pr may prevent the accelerated coronary arteriosclerosis after heart transplantation without significant changes in TC and LDL.

Animals↗
PubMed1996

Weak expression of blood type B antigen in kidney tissue and successful B-incompatible kidney transplantation without special treatments.

Much attention has been paid to only natural antibody titer of the recipients in ABO-incompatible kidney transplantation. In this study, we looked at the distribution of blood type antigens in the kidney tissue. Thirty-seven biopsy specimens from patients with nephritis or transplanted kidneys were recruited. Fifteen were type A, 14 were type B, and 8 were type AB. Kidney tissues were stained with anti-A or anti-B antibody using immunohistological staining. The stained dots in each section were regarded as the area and were measured by image analyzer. B antigen was expressed very weakly both in the glomeruli and in interstitium as compared with A antigen. In type AB, B antigen was less expressed than A antigen. Based on these results, we performed B-incompatible kidney transplantation. No rejection was seen without preoperative depletion of natural antibody and splenectomy. These results may suggest that type B-incompatible kidney transplantation might possibly be performed without preoperative depletion of natural antibodies.

ABO Blood-Group System↗
PubMed1996

Intratumoral heterogeneity and inverse correlation between expression of E-cadherin and collagenase type IV in human gastric carcinomas.

We examined the expression of E-cadherin and collagenase type IV in formalin-fixed, paraffin-embedded specimens of human gastric carcinoma by an in situ mRNA hybridization (ISH) technique. The ISH technique revealed intertumoral heterogeneity for expression of E-cadherin and collagenase among 12 cases of early gastric cancer and 13 cases of advanced gastric cancer. In the majority of the tumors, we found an inverse relationship between the reactivities of E-cadherin and collagenase type IV. Specifically, E-cadherin was expressed at higher levels in the center of the neoplasms than in their periphery, whereas collagenase type IV was expressed at a higher level in the periphery (invasive edge) than in the center. Advanced gastric cancers with high levels of expression for collagenase type IV in the periphery had a higher incidence of distant lymph node metastasis than those with low expression. The data show an inverse relationship between E-cadherin (involved in cell-to-cell adhesion) and collagenase type IV (involved in invasion) in different zones of human gastric carcinoma and suggest that the relative expression of these independent genes may be involved in local invasion and metastasis.

Base Sequence↗
PubMed1996

[Indication and clinical results of heart transplantation in the terminal stage of ischemic cardiomyopathy].

The results of medical therapy has been very poor for ischemic cardiomyopathy with inoperable coronary artery disease and left ventricular ejection fraction less than 20%, therefore, heart transplantation is considered to be definite indication for those patients. However, the limited supply of suitable donor organs imposes constraints upon the decision of whether patients are selected for transplantation or for alternative therapy including coronary artery bypass grafting (CABG), semipermanent use of implantable left ventricular assist device, or cardiomyoplasty even in the western countries. The heart transplantation therapy has not been accepted in Japan at the present time, therefore, such alternative therapy should be tried still more aggressively in our country. CABG is most established surgical technology among the alternative therapies for transplantation and realistic in availability. Many institutes in the western countries adopt the therapeutic strategy of aggressive trial of CABG for ischemic cardiomyopathy in the first stage and to use ventricular assist device as a bridge for heart transplantation in failure cases. Although the effects of CABG may not be permanent and ultimate heart transplantation may be required for those patients, still CABG therapy is considered reasonable, because of the shortage of supply of donor heart, rejection and the progression of coronary artery disease of transplanted heart in the chronic stage. The necessity and indication of heart transplantation for ischemic cardiomyopathy have not been discussed adequately in Japan, however, more than 5000 patients under 60-year-old are killed annually due to ischemic heart disease in our country. More hot discussion on heart transplantation is deems to be necessary for ischemic cardiomyopathy.

Cause of Death↗
PubMed1996

[Comparative study of mRNA expression of E-cadherin and collagenase IV in early and advanced cancers].

During the process of invasion, tumor cells must detach from the primary neoplasm and degrade host stroma. E-cadherin is responsible for the cell-cell adhesion and collagenase IV is the one of the matrix metalloproteinases. We determined whether the levels of mRNA for E-cadherin and collagenase IV were differently expressed within 12 cases of early and 13 cases of advanced gastric cancers using a rapid calorimetric in situ hybridization assay for mRNA. In 6 of 12 early cancers, we found a decreased expression of E-cadherin mRNA in the invasion edge compared to the main tumor. In advanced gastric cancers, 3 out of 13 cancers also exhibited this finding. Higher expression of the collagenase IV at the invasion edge of the tumor compared to the main tumor was observed in half of the early and advanced gastric cancer cases. Inverse expression levels of E-cadherin and collagenase IV mRNA were observed in 6 of 12 early cancers. However, only one of 13 advanced cancer cases expressed the same finding.

Adenocarcinoma↗
PubMed1996

[Assessment of Japanese patients receiving heart transplants overseas].

No heart transplants have been performed in Japan due to various obstacles since the only operation performed in 1968. Since 1981, a number of patients requiring heart transplants have been accepted by foreign transplantation centers in England, the U.S.A., and Germany. This report describes an investigation of the postoperative course of these Japanese heart transplant patients and discusses the problems regarding transplantation in Japan. Of the 21 transplant patients, the diagnosis was dilated cardiomyopathy in 17, restrictive cardiomyopathy in 1, hypertrophic cardiomyopathy in 2, and congenital muscle dystrophy in 1. All patients survived surgery but three died in the long-term period. The causes of death were acute rejection (after 3 months), chronic rejection (after 50 months) and infection (after 30 months). The actuarial survival curve of these patients was 95.0% for one-year survival and 86.4% for three-year survival. The postoperative functional class was NYHA classification I in all patients (100%). Ninety-three percent of patients returned to work. Immunosuppressive therapies included triple drug therapy in 14 patients (66.7%), double drug therapy in 4 (19.0%), ciclosporin alone in 2 (9.5%) and FK506 in 2 (5.0%). The incidence of acute rejection was 1.56 episodes per patient per year within 3 months and 2.9 episodes per patient per year within 1 year. The postoperative courses of Japanese patients who underwent heart transplantation at foreign transplantation centers were satisfactory. These results will encourage heart transplantation in Japan.

Adolescent↗
PubMed1996

[Papillary muscle rupture complicating acute myocardial infarction--treatment with mitral valve replacement and coronary bypass surgery in acute phase].

Complete rupture of a papillary muscle following acute myocardial infarction is a severe complication that is typically associated with acute left ventricular failure, pulmonary edema, and relentless clinical deterioration. The reported mortality rates without surgical intervention is almost 90%, therefore, prompt operation without prolonged attempts at medical stabilization is the key to decrease operative mortality. Although the complete coronary revascularization in conjunction with mitral valve replacement is advocated in the western medical academic society, there is only a few case of conjunct surgery has been reported in Japan. Three successful cases of conjunct surgery of mitral valve replacement and coronary complete revascularization in acute phase within one week from the onset of acute myocardial infarction (AMI) are described. There were one male and two female patients with an average age of 60-year-old (range 48-67), who developed cardiogenic shock and admitted to our hospital. The average interval between onset of AMI and the appearance of mitral regurgitation (MR) was 38 hours, and that of the appearance of MR and admission was 40 hours. Surgeries were performed within 26 hours (average 13 hours) after admission. The mitral valve was replaced with a mechanical valve (St. Jude Medical Valve) and a complete coronary revasculatization was done using saphenous vein graft. The average period of operation time and aortic cross clamping time were 6 hours 22 minutes and 109 minutes respectively. The average number of coronary grafting was 2.3 (range 1-3). Postoperative recovery from cardiogenic shock was uneventful in all three patients. The average periods of ICU stay and hospital stay were 5 days and 43 days respectively. All patients have regained their social activities with mean follow up period of 52 months. Since ischemic heart disease remains the leading cause of death in such patients, it is suggested that complete coronary revascularization should be performed immediately in conjunction with valve replacement even in the acute phase after onset of AMI.

Aged↗
PubMed1996

[Aortic inner surface morphology in aortic disease by three-dimensional transesophageal echocardiography].

Aortic inner surface morphology in various pathologies was investigated using three-dimensional (3D) transesophageal echocardiography to clarify the feasibility and limitations for clinical application. Transesophageal echocardiography was performed in 16 patients with aortic disease (12 aortic dissection, 4 aortic sclerosis) and 5 with normal aorta. The transesophageal transverse view of the descending aorta was taken every 2 mm by manually withdrawing the probe. Each image was recorded using VTR during one heart beat, then stored in the memory of a personal computer as a data base for the subsequent 3D reconstruction. The aortic inner surface was displayed using distance and gradient shading. Three-dimensional reconstruction images were obtained in all patients. The aortic inner surface was reconstructed as a wall with ringed protrusion in patients with normal aorta and a rugged wall with various sized protrusions in patients with atherosclerotic plaques by 3D transesophageal echocardiography. However, it was impossible to differentiate calcified lesions from non-calcified areas of plaques. In aortic dissection, 3D reconstruction provided information regarding the spatial anatomy of the dissection in 10 of 12 patients, accurate shape and location of the intimal tears in 3 of 5 patients, and movement of the intimal flap in 9 of 12 patients. However, reconstruction of the false lumen failed in two patients who had false lumens filled with spontaneous contrast echo. Three-dimensional transesophageal echocardiography is potentially useful for estimating the inner surface morphology and spatial extent and actual location of the aortic abnormalities, but there are limitations in evaluating tissue characterization and reconstructing the lumen with spontaneous contrast echo.

Adult↗
PubMed1995

Usefulness of a prototype intravascular ultrasound imaging in evaluation of aortic dissection and comparison with angiographic study, transesophageal echocardiography, computed tomography, and magnetic resonance imaging.

The aim of this study was to evaluate the accuracy of information obtained with a prototype intravascular ultrasound (IVUS) system in chronic aortic dissection by comparing results with angiography, transesophageal echocardiography (TEE), computed tomography, or magnetic resonance imaging. We assigned 15 patients to IVUS imaging after they underwent angiography. The detection rate of the intimal flap was 100% in all segments of the aorta, and the detection rate of the intimal tear was 0%, 50%, 50%, and 77.8% in the ascending, arch, descending, and abdominal aorta, respectively. IVUS demonstrated 100% of the celiac and renal arteries, and 80% of the superior mesenteric arteries as well as their relation to dissection. It clarified the origin of 12 of 60 main abdominal branches (20%) which were not clear on the angiogram. It also determined the distal extent of the dissection in all cases. With regard to the size of the vessel, there was a good correlation between IVUS and computed tomographic values (r = 0.98, p < 0.01). No complications occurred in any patient. IVUS accurately demonstrated thrombus or spontaneous echo contrast in the false lumen that was confirmed with computed tomography or TEE, or both. It was especially useful in evaluating the abdominal aorta with regard to determining the size of the vessel, the extent of dissection, the relation of the branches to the false lumen, and the detection of intimal tears--important information for follow-up of patients and for planning surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Left atrial ball thrombus in the SLE patient without organic mitral lesion].

A case of 77-year-old female patient with the left atrial ball thrombus without organic mitral valve lesion is reported. She had a history of SLE for one year and experienced pericarditis 2 months before this admission. A 2-D echo examination at that time did not show any abnormal shadow in the left atrium. The repeated 2-D echo on this admission demonstrated peduncular left atrial thrombus of 2 x 1.5 cm in size. Surgical removal of the thrombus was performed successfully. Her cardiac rhythm was atrial fibrillation, but other possible factors related to the intracardiac thrombus formation such as bradycardia, left atrial dilatation or low cardiac output were not noted. Although lupus anticoagulant and anticardiolipin antibody were negative before the operation, participation of SLE in formation of the left atrial thrombus was highly suspected.

Aged↗