Search PubMed⌕ Search

Biomedical subjects

M Kitamura

Publications and source records attributed to M Kitamura.

At least 775 records · Page 43Linked to original sources
PubMedDate not supplied

HLA-DR antigen and HLA-DRB1 genotyping with nonobstructive azoospermia in Japan.

We previously reported that the HLA-A33, -B13, and -B44 antigens, which are major histocompatibility complex class I molecules, are involved in the susceptibility of nonobstructive azoospermia in Japanese men. In this report, HLA-DR antigens, which are class II molecules, are investigated by advanced DNA typing in addition to classical serological typing to study a more complex genotype of HLA-DRB2. Genotyping was performed by the polymerase chain reaction-sequence-specific primer (PCR-SSP) method of analysis and/or by a commercial rapid assay based on the polymerase chain reaction (PCR), followed by reverse dot-blot hybridization of PCR products (the Inno-LiPA assay). The allele frequencies of the HLA-DR13 antigen and the -DRB1*1302 allele were significantly higher in Japanese subjects with nonobstructive azoospermia compared with a control group of healthy Japanese men, and these alleles were associated with relative risks for nonobstructive azoospermia of 4.2 and 4.9, respectively. If we suppose this strong linkage to both HLA class I and II antigens is due to linkage disequilibrium, it may suggest the existence of a novel gene involved in spermatogenesis in the class III region, which is located between the class I and class II regions and contains several genes other than HLA.

Chromosomes, Human, Pair 6↗
PubMedDate not supplied

Volvulus of the ileum in adult diagnosed pre-operatively by helical 3-dimensioned computed-tomography.

A 46 year-old male who was strictly diagnosed as having volvulus of the ileum based on the pre-operative information brought by computed tomography (CT) and helical (spiral) 3-dimensioned computed tomography was surgically treated. The post-operative course was satisfactory and the patient is now under observation without any exacerbation of symptoms one year after surgery.

Humans↗
PubMedDate not supplied

Dieulafoy-like lesions of colon and rectum in patients with chronic renal failure on long-term hemodialysis.

Two rare cases with Dieulafoy-like ulcer bleeding of the colon and rectum are reported. The patients have been suffering from chronic renal failure (CRF) on long-term hemodialysis (HD), and they were brought to Saiseikai Yahata General Hospital with anal bleeding. In both patients, colonoscopy was performed, showing arterial bleeding from a protuberant vessel on the mucosa of the rectum in Case 1 and gradual arterial bleeding from the protuberant vessel on the ascending colon in Case 2. For both cases, endoscopic clipping treatment was done for hemostasis and was successful.

Aged↗
PubMedDate not supplied

Successful surgical resection of solid cystic tumor of the pancreas with multiple liver metastases and a tumor thrombus in the portal vein.

We report a case of solid cystic tumor of the pancreas with widespread liver metastases and a tumor thrombus in the portal vein. The patient was a 43-year-old woman. She was referred because of an upper abdominal mass and weight loss. Computed tomography disclosed a 10-cm cystic and calcified mass in the body and tail of the pancreas and multiple masses in the liver. She underwent a distal pancreatectomy with splenectomy, extended right lobectomy, and partial resection of the liver. All the tumors were completely resected despite the presence of 20 liver metastases. Histopathological studies showed a tumor thrombus in the intrahepatic portal vein. The patient is well without any signs of recurrence 8 months after the operation. Aggressive surgical resection is considered to yield a good outcome for solid cystic tumor with liver metastases and tumor thrombus of the portal vein.

Adult↗
PubMedDate not supplied

Benign biliary stricture associated with atherosclerosis.

We report a case of benign bile duct stricture that could not be differentiated from intrahepatic bile duct carcinoma preoperatively. The patient was a 79-year-old man. Computed tomography showed dilatation of the intrahepatic bile duct in the left lobe. Direct cholangiography showed segmental stricture of the left bile duct. Angiography showed narrowing of the left hepatic artery. Although bile cytology did not show malignant cells, we suspected intrahepatic bile duct carcinoma preoperatively. We performed extended left hepatic lobectomy. Histopathologic examination of the resected duct also showed no malignant cells; fibrosis with infiltration by lymphocytes was seen at the bile duct stricture. In addition, the resected liver specimen showed sclerotic change in the intrahepatic arteries. The postoperative course was uneventful for more than 26 months, without recurrence or cholangitis. We encountered a very rare case of benign segmental bile duct stricture, which was difficult to differentiate from bile duct carcinoma. We think the biliary stricture was secondary to atherosclerosis which may have caused bile duct ischemia.

Aged↗
PubMedDate not supplied

Partial resection for leiomyoblastoma of stomach.

We herein report the case of a 51-year-old male with a submucosal tumor of the stomach which was histopathologically demonstrated to have features compatible with leiomyoblastoma. As the submucosal tumor of the posterior wall of the antrum, which was initially found in the upper gastrointestinal series done during a health examination, had grown 3.8 cm in diameter, the partial resection of the full thickness of the gastric wall containing the tumor with a sufficient tumor margin was performed.

Humans↗
PubMedDate not supplied

Assessment of cardiac allograft rejection with electrophysiology of the conduction system and histopathology of the ventricle.

Correlation between the effective refractory period of the conduction system and the histopathologic grade of the ventricle was examined in the rat cardiac allograft during acute rejection. Lewis rats were recipients of intraabdominal heart grafts from brown Norway rats (allogeneic group, n = 42) or Lewis rats (syngeneic group, n = 15). No immunosuppressant was given. The effective refractory period of the conduction system was measured by the programmed atrial extrastimulus method (basic cycle length, 150 msec) just before the time of death. Specimens of the transplanted hearts were examined histopathologically and the histopathologic grade of rejection was scored according to the standardized grading system of the International Society for Heart and Lung Transplantation. The effective refractory period of the allogeneic heart was significantly longer starting on the third day after transplantation (p less than 0.01). The effective refractory period of the allogeneic heart was more prolonged as the severity of rejection increased. The correlation between the effective refractory period (Y) and the histopathologic grade (X) of the allogeneic group was statistically significant (r = 0.955; Y = 10.3X + 81.0; p less than 0.01). The effective refractory period of all syngeneic hearts and allogeneic hearts of postoperative day 1 and 2 were statistically equivalent to the period of native rat hearts (81.0 +/- 2.0 msec; n = 6). The histopathologic grade of the conduction system was the same as that of the ventricle. We conclude that the effective refractory period of the conduction system could be a useful measure to predict the histopathologic grade of cardiac allograft rejection.

Abdomen↗
PubMedDate not supplied

Electrophysiologic assessment of the transplanted canine heart: correspondence to histopathologic findings in acute rejection.

This study was undertaken to electrophysiologically find signs of rejection after heart transplantation. A donor heart with a created atrial septal defect was implanted in the retroperitoneal space by anastomosing the thoracic aorta and left pulmonary artery of the donor heart to the abdominal aorta and inferior vena cava of the recipient heart, respectively. Endocardial leads were set up in the right atrium in the vicinity of the bundle of His and in the right ventricle. Cyclosporine (10 to 18 mg/kg/day, continuously) and prednisolone (1.0 mg/kg/day, for the first 4 days) were given orally. Electrophysiologic examinations were performed 1 to 4 days (control data) after the transplantation and were compared with data obtained 5 to 21 days after operation on 12 mongrel dogs. Finally, histopathology of the donor heart was studied. Results showed that the effective refractory period (ERP) of the atrioventricular conduction system was prolonged in six animals from 120 +/- 25 to 192 +/- 35 msec (p less than 0.02) on average. The ERP of the ventricle was shortened in four dogs from 153 +/- 36 to 123 +/- 17 msec (p less than 0.05). Specimens disclosed mononuclear cell infiltration in the atrioventricular node, the bundle of His, and the right and left bundle branches in eight of 12 cases and mild to moderate myocyte damage with cell infiltration in the ventricular septum of the same eight hearts. The ERP of the atrioventricular conduction system showed no change in four cases without mononuclear cell infiltration in the conduction system. These results suggested the feasibility of electrophysiologic monitoring as a means for detecting acute rejection in the prenecrotic stage in transplanted hearts.

Acute Disease↗
PubMedDate not supplied

MR imaging of hepatosplenic sarcoidosis.

We present a case of hepatosplenic sarcoidosis. Splenic lesions were detectable by both MRI and dynamic CT. They were demonstrated as multiple low signal intensity lesions on T2-weighted images obtained by MRI and as low density lesions by dynamic enhanced CT. Hepatic focal lesions were not apparent on CT or MRI. After steroid therapy, both dynamic enhanced CT and MRI showed disappearance of the splenic lesions. These are valuable modalities for detecting focal splenic sarcoidosis and evaluating the effect of steroid therapy.

Female↗
PubMedDate not supplied

Preliminary study of uneven fractionation radiotherapy combined with chemotherapy for esophageal cancer.

Between March 1992 and September 1993, nine patients were treated with combined-modality therapy of uneven fractionation radiotherapy and chemotherapy (CDDP+ 5-FU) before esophagectomy. All patients had a T4 tumor that was evident on the chest CT scan, MRI, or bronchofiberscopy. In the uneven fractionation radiotherapy, patients received 5 Gy on Fridays and daily doses of 1.2 Gy the following Monday through Thursday for 22 days, to yield a total dose of 34.4 Gy. CDDP (40 mg/body) was administered intravenously as a slow infusion just before each 5 Gy treatment for a total of five doses. 5-FU (300 mg/m2/day) was also administered intravenously as a slow infusion for each of the 22 treatment days. As restaging failed to document a significant response (improvement to T3 or better), a further dose of irradiation was given in two patients (22%). Five patients (56%) had a partial response. The tumors in eight patients (89%) could be resected after this combined modality treatment. Histological assessment of the resected specimens indicated grade 3 in two patients and grade 2 in six patients. At a median follow-up of 14 months, seven patients are alive and four patients are clinically disease free. Uneven fractionation radiotherapy combined with chemotherapy improved local control and the resectable rate in these patients.

Adult↗
PubMedDate not supplied

Segmental flow-resistance relationship in pulmonary lobar transplantation: possibility for donor lobe evaluation in pediatric lung transplantation.

Pulmonary lobar transplantation is an option for pediatric lung transplantation, and it has the potential of extended applications. We compared the relationship between segmental blood flow and segmental vascular resistance of the pulmonary lobe with that of the transplanted single lung. Eight of 14 puppies received a left upper pulmonary lobe from double-weighed adult dogs, and the other six puppies received a left lung from puppies. All recipient dogs were treated with oral cyclosporine (15 mg/kg/day) and intramuscular prednisolone (1.0 mg/kg/day), after the operation. Pulmonary arterial and left atrial pressures and segmental flow of the lungs were measured at rest and while the inferior vena cava or right pulmonary artery was clamped, before and 1 hour and 2 weeks after lung transplantation. Vascular resistance of the lung segment was calculated at each hemodynamic state. Segmental resistance of the lung at rest significantly increased from pretransplantation to 1 hour after transplantation (pulmonary lobe group, 2211 +/- 42 to 2555 +/- 61 dyne.sec.cm-5; single lung group, 2126 +/- 56 to 2557 +/- 72 dyne.sec.cm-5) and recovered 2 weeks after transplantation in both groups. However, by means of partial clamp of the right pulmonary artery, segmental resistances of 1 hour after transplantation pulmonary lobe (2248 +/- 37 dyne.sec.cm-5), and single lung (2206 +/- 34 dyne.sec.cm-5) at the same segmental flow of the pretransplantation state (310 to 320 ml/min) were equivalent to those of the pretransplantation lungs. There was no significant difference in the segmental resistance at any segmental flow between the pulmonary lobe and single lung before and after lung transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Development of a miniature intraventricular axial flow blood pump.

A new intraventricular axial flow blood pump has been designed and developed as a totally implantable left ventricular assist device (LVAD). This pump consists of an impeller combined with a guide-vane, a tube housing, and a DC motor. The pump is introduced into the LV cavity through the LV apex, and the outlet cannula is passed antegrade across the aortic valve. Blood is withdrawn from the LV through the inlet ports at the pump base, and discharged to the ascending aorta. Our newly developed axial flow pump system has the following advantages: 1) it is a simple and compact system, 2) minimal blood stasis both in the device and the LV cavity, 3) minimal blood contacting surface of the pump, 4) easy accessibility with a less invasive surgical procedure, and 5) low cost. A pump flow > 5 L/min was obtained against 100 mmHg differential pressure in the mock circulatory system. The pump could produce a passive pulsatile flow effect with a beating heart more efficiently than other non-pulsatile pumps because of minimal pressure drop and inertia along the bypass tract. Anatomic fit studies using dissected hearts of dilated cardiomyopathy (DCM) cadavers showed that this pump could smoothly pass through the aortic valve without any interference with mitral valve function. Recently, a dynamic pressure groove bearing and a miniature lip seal have been developed. The dynamic pressure groove bearing has a simple structure and acts as a pressure resistant sealing mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Dilated↗
PubMedDate not supplied

Gene delivery into the renal glomerulus by transfer of genetically engineered, autologous mesangial cells.

To obviate the problem of rejection in situations where cells are used as vectors for gene delivery, the feasibility of using autologous mesangial cells cultured from renal biopsy specimens was studied for the purpose of gene transfer into the glomerulus. Using the calcium-phosphate co-precipitation method, a reporter gene which encodes bacterial beta-galactosidase was introduced into cultured mesangial cells derived from renal biopsy tissue of rats. Stable transfectants were established in the presence of a selection drug and then transferred back into the contralateral kidneys of the same animals via renal artery injection. Among 5 rats tested, expression of beta-galactosidase was detected in the isolated glomeruli from 4 injected kidneys. One week after cell injection, 31 +/- 13% of the glomeruli showed positive X-gal (5-bromo-4-chloro-3-indolyl beta- D-galactopyranoside) staining, indicating expression of the transferred gene. The use of autologous mesangial cells from biopsy specimens is thus realistic and would be useful to obviate the risk of rejection in the mesangial cell vector system.

Animals↗
PubMedDate not supplied

Prognostic significance of immunological parameters in patients with esophageal cancer.

BACKGROUND: The role of immunosurveillance in the fight against cancer is well known. In addition, cancer patients have been reported to have an impaired immune function. In patients with esophageal cancer, however, the relationship between the immunological parameters of the host and their survival has not yet been evaluated fully. MATERIALS AND METHODS: Of 103 patients with esophageal cancer who underwent esophagectomy, lymphocyte subsets (CD4+ and CD8+), the PHA response, and natural killer cell (NK) activity were all assessed in relation to clinicopathological features and the prognostic significance was evaluated using both a univariate and multivariate analysis. RESULTS: The CD4+/CD8+ ratio in 58 (56%) patients was higher than the mean of the control, while the PHA response and NK activity in 74 (72%) and 70 (68%) patients, respectively, were lower than 1 SD below the mean of the control. None of these three parameters demonstrated a low value in 5 patients, while 1, 2 and 3 parameters showed a low value in 28, 49 and 21 patients, respectively. The survival rate of the patients with low values in all of three of these parameters was significantly worse than that for the patients in whom the number of low parameters was less than two. A multivariate analysis revealed that tumor invasion and the number of low values in these parameters were independently significant prognostic factors. CONCLUSIONS: This survival analysis revealed that low values in the CD4+/CD8+ ratio, the PHA response, and the NK activity will help predict a poor prognosis in patients with esophageal cancer.

CD4-CD8 Ratio↗
PubMedDate not supplied

The role of prostanoid in hepatic damage during hepatectomy.

BACKGROUND/AIMS: The aim of this study in hepatectomy is to investigate whether or not hepatic ischemia elevates the serum prostanoid levels, and whether or not thromboxane A2 (TXA2) synthetase inhibitor (OKY 046) improves hepatic damage. MATERIALS AND METHODS: The prostanoid levels were measured in 22 hepatectomy cases. The beneficial effects of thromboxane A2 synthetase inhibitor were examined in cases who underwent hepatectomy under hemihepatic vascular control. The total prostanoid levels (6-keto PG Fla+ PGE2 + TXB2) were measured in 22 cases before and after hepatectomy. The hepatic ischemic time (HIT) was defined as the time required to perform a hepatic mobilization plus the right hemihepatic vascular control technique. RESULTS: The total prostanoid levels increased after hepatectomy (P < 0.01). The changes in the total prostanoid levels positively correlated with the HIT (P < 0.01). The 17 cases who underwent hepatectomy with the HIT were randomly divided into 2 groups; the OKY group (n = 9), OKY 046 (0.2 mg/kg/hr), the control group (n = 8); no drug was given. The OKY 046 administration reduced the TXB2 levels (P < 0.01), without any changes in the PGE2, or 6-keto PGF1a levels. The serum glutamic oxaloacetic transaminase levels after operation were lower, and the hepaplastin tests were higher in the OKY group than those of the control (P < 0.05). CONCLUSION: These results demonstrated that hepatectomy under ischemia elevated the prostanoid levels. OKY 046 significantly reduced the TXB2 levels and the degree of hepatic damage in hepatectomy under ischemia.

Aspartate Aminotransferases↗