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Biomedical subjects

H Yamabe

Publications and source records attributed to H Yamabe.

At least 127 records · Page 7Linked to original sources
PubMed1995

Radiofrequency catheter ablation of accessory atrioventricular pathway in Wolff-Parkinson-White syndrome.

Eighty patients with manifest or concealed Wolff-Parkinson-White (WPW) syndrome underwent catheter ablation of 86 accessory pathways (AP) using radiofrequency current. There are 65 AP located on the left side and 21 on the right side of the heart. The atrioventricular reciprocating tachycardia was previously documented in 77 patients and atrial fibrillation with a rapid ventricular response in 21 patients. Ablation was attempted via a catheter positioned at the atrial aspect of the tricuspid annulus in patients with a right-sided AP and via a catheter positioned in the left ventricle directly below the mitral annulus in patients with a left-sided AP. AP conduction was permanently abolished in 82 of the 86 pathways (95%). The number of radiofrequency current applications for these 82 successfully ablated AP was 7.6 +/- 0.9. Of the 65 left-sided and 21 right-sided AP, 62 (95%) and 20 AP (95%) were successfully ablated, respectively. The current application to the right-sided AP was 16.7 +/- 2.2, which was greater than that to the left-sided one (4.7 +/- 0.6, p < 0.001). No serious complication was observed in any case. Catheter ablation of AP using radiofrequency current is an effective and safe therapeutic modality for patients with symptomatic WPW syndrome.

Adolescent↗
PubMed1995

Cardiac involvement in a family with Becker muscular dystrophy.

We report a family with Becker muscular dystrophy (BMD) presenting with cardiac involvement. The proband was a 41-year-old Japanese man who was hospitalized with exertional dyspnea and muscle weakness. Cardiac examination showed findings consistent with dilated cardiomyopathy. Dystrophin immunohistochemical analysis showed a discontinuous patchy staining pattern in cardiac and skeletal muscles biopsied from the proband. His brothers had high creatine kinase (CK) activity and abnormal electrocardiogram. Dystrophin gene analysis revealed that the proband and his brothers had G-to-T transversion at the terminal nucleotide of exon13. We conclude that the mutated dystrophin gene may cause cardiac involvement as a symptom precedent to skeletal muscle involvement.

Adult↗
PubMed1995

Primary malignant lymphoma of the central nervous system--report of four long-term survivors.

Four of 47 patients treated between 1977 and 1993 for histologically confirmed primary malignant lymphoma of the central nervous system (non-Hodgkin's type of B-cell origin) achieved long-term survival for more than 5 years with a good quality of life. Three have remained disease-free for 9-12.5 years. The fourth achieved complete remission for more than 5 years before death from tumor recurrence. All four patients were treated with a standard therapeutic regimen, consisting of radiotherapy (50-60 Gy local and 30-40 Gy whole brain irradiation) followed by four to six courses of chemotherapy with cyclophosphamide, vincristine, adriamycin, and prednisolone at 4- to 8-week intervals. No further treatment was performed after remission had been obtained. No specific predictors for long-term survival including sex, age, tumor location, multiplicity of lesions, histology, or treatment modality was identified. All four patients showed an immediate tumor response to radiation. We recommend chemotherapy at increasing intervals as part of the post-therapeutic management of long-term, disease-free patients.

Adult↗
PubMed1995

TGF-beta upregulates interleukin 6 production by rat glomerular epithelial cells in vitro.

BACKGROUND: Glomerular epithelial cells (GECs) play an important role in maintaining normal glomerular permselectivity in vivo. Recent in-vitro studies have suggested that GECs are able to secrete substances which may modulate glomerular injury. Interleukin 6 (IL-6) has been shown to be a potent mediator of glomerular injury. It is also known that IL-6 could be produced by various cells. METHODS: IL-6 production by rat GECs in culture was examined in this study. IL-6 bioactivity in conditioned medium collected from cultured GECs (GEC-CM) was measured using IL-6 dependent murine hybridoma cell line, namely B9 cells. IL-6 gene expression by GECs was analysed by reverse transcriptase polymerase chain reaction (RT-PCR). Effects of recombinant IL-6 on the proliferation of GECs and type IV collagen secretion by GECs were evaluated to examine the possible role of GECs derived IL-6. RESULTS: GEC-CM stimulated B9 cells growth in a dose dependent fashion. The mitogenic activity was inhibitable by anti-murine IL-6 antibody. De-novo synthesis of IL-6 was suggested by the demonstration of IL-6 mRNA by GECs using the RT-PCR. Secretion of IL-6 by GECs was increased by transforming growth factor beta but not by IL-1 beta. Recombinant murine IL-6 stimulated GECs growth and their type IV collagen secretion. CONCLUSIONS: These results indicate that rat GECs could produce IL-6 which may modulate glomerular inflammation and that IL-6 may function as an autocrine factor for GECs.

Animals↗
PubMed1994

[Huge leiomyosarcoma of the mesentery: a case report].

A patient, a 63 year-old-man, was admitted suffering from discomfort in the left abdominal area; this proved to be a case of leiomyosarcoma of the mesentery. An upper gastrointestinal series revealed stenosis in the 3rd portion of the duodenum, and shift of the entire intestine to the right side. Computed tomography showed a giant mass lesion with a central necrosis. Selective arterial angiography showed a heterogeneous tumor stain with several feeders and drainage veins. A partial resection of the intestine around the Treitz's ligament and left hemicolectomy was required due to the tumor's invasion of the intestinal wall and transverse colon. The operation was successfully performed supported by the angiographic findings. The resected tumor was 23 cm in diameter, 2330 g in weight, and was filled with blood. The histological diagnosis was leiomyosarcoma of the mesentery. The patient has been doing well during the 6 months postoperative period.

Humans↗
PubMed1994

Lactate threshold is not an onset of insufficient oxygen supply to the working muscle in patients with chronic heart failure.

It has been argued that the lactate threshold (LT) serves as an index to reflect circulatory insufficiency in transporting oxygen during submaximal exercise in patients with chronic heart failure (CHF). We examined whether or not the LT was related to an insufficient oxygen supply in patients with CHF. Sixty-nine patients were divided by NYHA classification. All underwent invasive cardiopulmonary exercise testing. The rate of increase in oxygen delivery (O2D) versus VO2 (delta O2D/delta VO2) was significantly lowered when work rate exceeded LT, that is, 1.32 +/- 0.35 to 1.05 +/- 0.37 (p < 0.01), 1.22 +/- 0.40 to 0.98 +/- 0.40 (p < 0.05), and 1.04 +/- 0.26 to 0.78 +/- 0.39 (p < 0.05) in NYHA classes I, II, and III, respectively. However, the rate of increase in leg O2D versus leg VO2 (delta LO2D/delta LVO2) did not change, that is, 1.25 +/- 0.20 to 1.29 +/- 0.20 (NS), 1.27 +/- 0.23 to 1.21 +/- 0.28 (NS), and 1.19 +/- 0.24 to 1.15 +/- 0.17 (NS) in classes I, II, and III, respectively. Leg venous PO2 was significantly different among three groups, that is, 23.7 +/- 3.4 mmHg, 23.2 +/- 2.8 mmHg, and 20.1 +/- 2.3 mmHg (p < 0.001), respectively. Thus, the oxygen supply to the working muscle did not become insufficient when work rate exceeded LT, and the LT occurred at different levels of leg PO2. It was concluded that the LT was not a result of anaerobiosis in patients with CHF.

Anaerobic Threshold↗
PubMed1994

Expression of sialosyl-Tn antigen (monoclonal antibody MLS102 reactive) in normal tissues and malignant tumors of the digestive tract.

Oncogenic transformation is often associated with changes in the glycosylation state of malignant cells. We investigated the immunohistochemical localization of sialosyl-Tn antigen [O-linked NeuAc(alpha 2-->6)GAINAc] using a novel monoclonal antibody MLS102 in normal and malignant digestive-tract tissues. In normal tissues, weak MLS102 immunoreactivity was observed in the epithelium of the esophagus, stomach and colon. However, MLS102 immunoreactivity was strong in the goblet cells of the duodenum, but not in the Brunner glands. In carcinomas of the esophagus, stomach, colon, pancreas and biliary tract, positive staining was detected with a high frequency (80%-100%). In mucinous carcinomas and signet-ring cell carcinomas, malignant cells themselves and the mucins they secreted were strongly positive for sialosyl-Tn antigen. There was no significant correlation between the frequency of expression of sialosyl-Tn antigen and the degree of differentiation (grade). However, in the case of well-differentiated adenocarcinomas, sialosyl-Tn antigen was found mainly in the supranuclear areas (Golgi area), on the apical surface and in the adjacent cytoplasm. In poorly differentiated adenocarcinomas, the antigen was often detected in the whole plasma membrane and cytoplasm. Therefore, monoclonal antibody MLS102 may be useful in further elucidating the characteristics of digestive-tract cancers, and possibly in their treatment.

Antibodies, Monoclonal↗
PubMed1994

Typical fibrolamellar hepatocellular carcinoma in Japanese patients: report of two cases.

We report herein the cases of two Japanese patients with typical fibrolamellar hepatocellular carcinoma treated at our institute. The first patient was a 19-year-old man with no hepatitis B or C viral infection and a normal, noncirrhotic liver in the nontumorous area. The second was a 36-year-old woman with no viral infection and a noncirrhotic liver in the nontumorous area. The clinicopathology, imaging appearances, and histology of both cases were similar to reports from the United States.

Adult↗
PubMed1994

Immunohistochemical demonstration of collagen types III and IV and myofibroblasts in the liver of patients with biliary atresia.

To clarify the pathogenesis of pericholangitis in biliary atresia, immunohistochemical and ultrastructural methods were used to quantify the amount of collagen types III and IV, and alpha-smooth muscle actin-positive myofibroblast present in the pericholangial tissue. Patients were divided into two groups: the early-stage group (n = 7; 15 to 30 days old at the time of the Kasai operation), and the advanced-stage group (n = 14; 8 months to 6 years old at the time of liver transplantation). The liver specimen was harvested at the time of the Kasai operation in the early-stage group, and during liver transplantation in the advanced-stage group. Liver tissue from the donor was used as the control. The specimen was visually inspected and classified into three grades to express the extent of proliferation. An increase of collagen types III and IV, and myofibroblast in the pericholangial area was seen even in 2- to 4-week-old patients, which became marked with the progression of the fibrotic disease process. This suggests that pericholangitis occurs in the very early stage of biliary atresia, perhaps before the development of bile duct obstruction.

Biliary Atresia↗
PubMed1994

Demonstration of entrainment and presence of slow conduction during ventricular tachycardia in arrhythmogenic right ventricular dysplasia.

During VT in two cases with arrhythmogenic right ventricular dysplasia, entrainment criteria, constant fusion beats except for the last entrainment beat, progressive fusion, and a localized conduction block associated with interruption of VT, were demonstrated with rapid ventricular pacing performed during VT. Furthermore, a long conduction interval was present during entrainment from the pacing site to the earliest activation site during VT, indicating the presence of a slow conduction area. VT in these cases was, thus, due to reentry with an area of slow conduction within the circuit.

Action Potentials↗
PubMed1994

Radiofrequency catheter ablation of concealed atrio-His bypass tract involved in paroxysmal supraventricular tachycardia.

In a patient with paroxysmal supraventricular tachycardia and without any evidence for preexcitation syndrome or dual atrioventricular (AV) nodal pathways, the tachycardia reentry circuit consisted of the AV node as an antegrade limb of the circuit and a concealed atrio-His bypass tract located in the posterior septum as a retrograde limb. During the tachycardia, the atrial potentials in the septal region and coronary sinus were inscribed in the QRS complex, and the earliest atrial activation site was located in the posterior septum. Ventricular extrastimulation at critically short intervals reproducibly demonstrated a ventriculo-His-atrial activation sequence with the same earliest retrograde atrial activation site as that during the tachycardia. Radiofrequency energy (20 W) was applied to this earliest activation site during ventricular pacing, which resulted in complete ventriculoatrial block within 2 seconds after energy application. The antegrade AV conduction property was not affected and the tachycardia was no longer induced. The patient has been free from tachycardia attack for a follow-up period of 8 months. Therefore, radiofrequency catheter ablation for an atrio-His bypass tract is feasible without inducing any AV conduction disturbance.

Adolescent↗
PubMed1994

Comparison of the effects of exercise and isoproterenol on the antegrade refractory period of the accessory pathway in patients with Wolff-Parkinson-White syndrome.

The effects of exercise and isoproterenol infusion on the antegrade effective refractory period of the accessory pathway (ERP-AP) were compared in 10 patients with Wolff-Parkinson-White (WPW) syndrome. During an electrophysiologic study, the ERP-AP (paced cycle length: 400 msec) was measured before and during isoproterenol infusion at a rate of 1 microgram/min. On the next day, a symptom-limited ergometer exercise test was performed and the ERP-AP (paced cycle length: 400 msec) was measured before and during the test using an indwelling atrial electrode catheter. Isoproterenol infusion and the exercise test increased the heart rate from 84 +/- 24 to 122 +/- 17 beats/min and from 85 +/- 25 to 128 +/- 25 beats/min, respectively (p = NS isoproterenol versus exercise). The ERP-AP was shortened from 268 +/- 34 to 230 +/- 19 msec with isoproterenol infusion (p < 0.001) and from 273 +/- 42 to 237 +/- 31 msec with the exercise test (p < 0.001). There was no significant difference between the effects of isoproterenol and exercise. The percent change in the ERP-AP with exercise (Y) was significantly correlated to that with isoproterenol infusion (X) (Y = -3.04 + 0.70X, r = 0.92, p < 0.001). In conclusion, isoproterenol infusion at the present dose shortens the ERP-AP to the same degree as exercise, and thus is useful for predicting the exercise-induced shortening of the ERP of the accessory pathway in patients with WPW syndrome.

Adolescent↗
PubMed1994

A clinicopathological analysis of early gastric cancer: retrospective study with special reference to lymph node metastasis.

We reviewed 217 cases of early gastric cancer (EGC) resected from 1978 through 1988. To determine the indications for curative resection by endoscopic mucosectomy (EM) for EGC, we paid special attention to lymph node metastasis examined after gastrectomy. The overall incidence of lymph node metastasis was 12.4%. It was 3.4% for mucosal (m-) cancer and 23.5% for submucosal (sm-) cancer. The maximum diameter of the lesion, depth of cancerous invasion, and location of the lesion showed positive correlations with lymph node involvement (p < 0.05). EGCs less than 20 mm in diameter had no lymph node metastasis. Pieces of mucosa about 20 mm in diameter on the average could be obtained with a single EM procedure. EGC with ulceration had a higher incidence of lymph node involvement than did that without ulceration. We conclude that if EM reveals an intramucosal gastric carcinoma less than 20 mm in diameter without ulceration, curative resection by EM is indicated.

Adenocarcinoma↗
PubMed1994

Clinical aspects of B-cell malignancy involving the BCL1/PRAD1 locus.

BCL1/PRAD1 is the gene locus involved in the t(11;14)(q13;q32) translocation, which often occurs in a proposed subtype of non-Hodgkin's lymphoma of B-cell phenotype (B-NHL), named mantle cell lymphoma (MCL). When 67 Japanese patients with B-NHL were examined using two separate probes composed of the BCL1 MTC probe and the PRADI cDNA probe, rearrangement of BCL1/PRAD1 or overexpression of PRAD1 was detected in 11 patients. Among 13 patients with MCL, 8 had the abnormalities (61%) and the MTC probe detected the BCL1 rearrangement in 5 (38%). Five of the 6 MCL patients studied (83%) showed PRAD1 overexpression. These frequencies were compatible with those reported for Western patients. Although the remaining three with BCL1/PRAD1 abnormalities were diagnosed as having other histologies, 11 patients had advanced diseases, with dissemination to the extranodal sites. Except for one with diffuse large cell lymphoma, they had a slowly progressive disease, and none of the patients displayed clinical or pathological transformation. The tumor cells usually expressed CD5 and lacked CD10. The cells were completely uniform in the expression of IgM and/or IgD, and in the absence of C mu gene deletion. It thus appears that B-malignancies involving the BCL1/PRAD1 locus constitute a refined disease entity.

Adult↗
PubMed1994

[A case of adrenal myelolipoma consisting of two masses with different red and yellow colors].

A 52-year-old woman with asymptomatic gross hematuria visited a hospital, where computed tomography and ultrasonography revealed a left suprarenal mass, which was diagnosed as adrenal myelolipoma. After two years observation, she was admitted to our hospital due to enlargement of the tumor, and left adrenalectomy was performed. The tumor consisted of two separate masses with different macroscopic appearances. One was type I, while the other was type II according to Soos' classification. We found no similar case in the literature. We added a review of 119 cases of surgically resected adrenal myelolipoma in Japan.

Adrenal Gland Neoplasms↗
PubMed1994

Qualitative and quantitative histopathology in transitional cell carcinomas of the urinary bladder. An international investigation of intra- and interobserver reproducibility.

BACKGROUND: Histopathologic, prognosis-related grading of malignancy by means of morphologic examination in transitional cell carcinomas of the urinary bladder (TCC) may be subject to observer variation, resulting in a reduced level of reproducibility. This may confound comparisons of treatment results. Using objective, unbiased stereologic techniques and ordinary histomorphometry, such problems may be solved. EXPERIMENTAL DESIGN: A study of 110 patients with papillary or solid transitional cell carcinomas of the urinary bladder in stage Ta through T4 was carried out, addressing reproducibility of both qualitative and quantitative grading methods. Grading of malignancy was performed by one observer in Japan (using the World Health Organization scheme), and by two observers in Denmark (using the Bergkvist system). A "translation" between the systems, grade for grade, and kappa statistics were used in evaluating the reproducibility. Unbiased estimates of nuclear mean volume, nuclear mean profile area, nuclear volume fraction, nuclear profile density index, and mitotic profile density index were obtained twice in 55 of the studied cases by one observer in Japan and one in Denmark, using a random, systematic sampling scheme. RESULTS: The results were compared by bivariate correlation analyses and Kendall's tau. The international interobserver reproducibility of qualitative gradings was rather poor (kappa = 0.51), especially for grade 2 tumors (kappa = 0.28). Likewise, the interobserver agreement on the Bergkvist scheme was poor (kappa = 0.43). On the other hand was the interobserver agreement on invasion high (kappa = 0.75). The intraobserver reproducibility of the quantitative histopathologic variables was excellent in both Japan and Denmark for estimates of nuclear mean volume (r = 0.93), for nuclear mean profile area (0.78 < r < 0.83), and for nuclear profile density index (0.85 < r < 0.89), whereas the reproducibility for nuclear volume fraction was somewhat poorer (0.68 < r < 0.64). The slopes of the correlation lines were not significantly different from unity. Estimates of mitotic profile density index also showed acceptable intraobserver reproducibility (Kendall's tau > 0.53). CONCLUSIONS: The international, interobserver reproducibility of the quantitative estimators yielded similar results for all histopathologic variables investigated, except for nuclear volume fraction (r = 0.54). This can probably be related to the manual design of the sampling scheme and may be solved by introducing a motorized object stage in the systematic selection of fields of vision for quantitative measurements. However, the nuclear mean size estimators are unaffected by such sampling variability. The results obtained in this study stress the need for objective, quantitative histopathologic techniques substituting qualitative, subjective methods in prognosis-related grading of malignancy.

Adult↗