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Biomedical subjects

H Yamabe

Publications and source records attributed to H Yamabe.

At least 73 records · Page 4Linked to original sources

Thrombin stimulates production of transforming growth factor-beta by cultured human mesangial cells.

Fibrin formation within the glomeruli occurs in various forms of human and experimental glomerulonephritis and it may play an important role in progressive glomerular injury. Transforming growth factor-beta (TGF-beta) has been shown to participate in the glomerular accumulation of extracellular matrix in glomerulonephritis. We investigated whether thrombin, an important coagulation factor, could modulate the production of TGF-beta by cultured human mesangial cells (HMC). TGF-beta levels in the culture supernatants were measured by ELISA using a specific antibody. The TGF-beta concentration was significantly increased by incubation of HMC with thrombin in a time-dependent manner. The stimulating effect of thrombin on TGF-beta was inhibited by addition of hirudin (a natural thrombin inhibitor) and argatroban (a synthetic thrombin inhibitor). In addition DFP-inactivated thrombin, which has no enzymatic activity, did not stimulate TGF-beta production. A protein kinase C inhibitor (H7) and a tyrosine kinase inhibitor (herbimycin A) also inhibited thrombin induced TGF-beta production. These findings suggested that thrombin may modulate the synthesis of TGF-beta via protein kinase C- and tyrosine kinase-dependent mechanisms in cultured HMC. Thus thrombin may participate in the accumulation of extracellular matrix in glomeruli through the augmentation of TGF-beta production.

Cells, Cultured↗

Primary testicular non-Hodgkin's lymphoma: a clinical study and review of the literature.

Non-Hodgkin's lymphoma (NHL) of the testis is a rare disease, and treatment outcome is generally poor. In this retrospective study, we investigated treatment results for testicular NHL in an attempt to develop an effective treatment policy for this disease. The survival rate and characteristics were retrospectively analyzed in eight patients with NHL of the testis who were treated between 1969 and 1991 at Kyoto University Hospital, Department of Radiology. Four patients were at stage IEA, one at stage IIEA, and three at stage IVEA. Of the eight testicular lymphomas, six were classed as intermediate grade lymphomas and two as high-grade lymphomas according to the Working Formulation. All of the eight patients received orchiectomy. Six patients received combined chemotherapy and radiation therapy as the primary treatment for the disease. One patient each was treated with radiation therapy alone or combination chemotherapy alone. The 5-year overall and disease-free survival rate was 45 and 33%, respectively. Even though almost all of the patients had received combination chemotherapy, high incidence of relapse in the central nervous system (CNS) was observed. Prophylactic treatment against such recurrence may be necessary to improve the treatment outcome of patients with testicular NHL.

Adult↗

An autopsy case of angioimmunoblastic T-cell lymphoma with a high content of epithelioid cells in the lymph node: immunohistochemical and genomic analyses.

A 79-year-old female developed red papulonodular eruptions on her extremities, facial erythema, generalized lymphadenopathy and high fever. Histopathology of an affected lymph node showed the features of angioimmunoblastic T-cell lymphoma with a high content of epithelioid cells. She died about two years after the onset despite therapy. Genomic Southern blotting and immunostaining of the lymph nodes were performed twice. In August of 1993, Southern blotting did not show any rearrangement of the immunoglobulin or the T-cell receptor (TCR) gene. Small or medium-sized lymphoid cells were positive for CD4 or CD8 (CD4:CD8 = 2:1). However, in September of 1994 (at autopsy), rearrangements of TCK C beta 1, J beta 2 and J gamma genes were observed. Small or medium-sized lymphoid cells were positive for CD4, but negative for CD8. Several large cells were positive for Latent Membrane Protein 1 (LMP1) of the Epstein-Barr virus (EBV). Our results proved that selective oligoclonal proliferation of tumor cells (probably CD4+) accompanied the disease progress.

Aged↗

Systemic lupus erythematosus associated with transverse myelitis and parkinsonian symptoms.

A 31-year old woman developed transverse myelitis after 10 years remission since she was first diagnosed as systemic lupus erythematosus. Although pulse methyl prednisolone resolved her myelitis, Parkinson-like symptoms developed subsequently after reduction of steroid. Treatments including apheresis did not improve her Parkinson-like symptoms such as rigidity, akinesia, impairment of speech and mask-like facial expression. Levodopa was effective as a symptomatic therapy. Orally administered cyclophosphamide eventually led her to remission and withdrawal from levodopa. Her clinical course and the absence of other possible causes prompted us to conclude that Parkinsonian symptoms as well as transverse myelitis may have developed as manifestations of central nervous system lupus.

Adult↗

Clinical application of cardiac output during ramp exercise calculated using the Fick equation--comparison with the 2-stage bicycle ergometer exercise protocol in the supine position.

The purpose of this study was to clarify whether the direct Fick method is applicable to the measurement of cardiac output (Q) during ramp exercise. Twelve patients with chronic health failure underwent both a ramp exercise test and a steady-state exercise test. Oxygen intake (VO2), arterial oxygen saturation and mixed venous oxygen saturation were continuously measured using a pulse oximeter and a fiberoptic catheter, and the arteriovenous oxygen difference (a-v O2 diff) and Q were calculated. Both VO2 and a-v O2 diff were significantly lower in the ramp protocol than in the steady-state protocol when they were compared at the same workload. However, the VO2 vs Q relationship and the VO2 vs a-v O2 diff relationship were very similar in the 2 protocols. The difference between Q measured during steady-state exercise and Q calculated at the matched VO2 during ramp exercise was small (3.7 +/- 7.0% and 5.6 +/- 6.6%). The results indicate that, clinically, Q measured by the direct Fick method with simultaneous measurement of VO2 and a-v O2 diff during ramp exercise is a good substitute for the true Q measured by the steady-state protocol. We conclude that Fick Q is applicable to ramp exercise.

Adult↗

Acute left ventricular dysfunction and left ventricular thrombus in a patient with cerebral hemorrhage.

A 66-year-old woman was admitted to the hospital with a cerebral hemorrhage. An echocardiogram showed severe left ventricular hypokinesis and a left ventricular thrombus. An electrocardiogram showed ST segment elevation in the precordial leads. The patient's creatine kinase level was elevated. A follow-up echocardiogram performed 1 month after admission showed normalization of left ventricular wall motion and disappearance of the thrombus. The results of thallium myocardial scintigraphy, coronary arteriography, and left ventriculography performed 1 month after admission were normal, and the patient was discharged without clinical sequelae. The cause of the patient's left ventricular dysfunction was believed to be not myocardial infarction or myocarditis, but a massive adrenergic discharge due to the cerebral hemorrhage.

Aged↗

Early detection of left atrial thrombus in acute cardiogenic cerebral embolism by transesophageal echocardiography.

Re-embolization tends to occur during the first 14 days after the onset of cardiogenic cerebral embolism. The usefulness of early transesophageal echocardiography (TEE) was investigated in 64 patients (33 men and 31 women, mean [+/-SD] age 70.1 +/- 12.6 years) who underwent TEE within 30 days of the onset of cardiogenic cerebral embolism. Patients were retrospectively classified into two groups based on the time from the onset of the embolism to performance of TEE: group A consisted of 33 who underwent TEE within 4 days of the onset and group B consisted of 31 who underwent TEE 5 to 30 days after the onset. Transthoracic echocardiography visualized a left atrial thrombus in two patients, and TEE detected thrombi in 14 patients: 11 in group A and 3 in group B. Lethal re-embolization occurred in two patients in group A who had highly mobile thrombi. Early TEE may be useful for detecting left atrial thrombi and predicting the risk of re-embolization in patients with acute cardiogenic cerebral embolism.

Acute Disease↗

[Renal lesions of rats induced by antibodies to cultured rat glomerular epithelial cells and mesangial cells].

Renal lesions of rats induced by antibodies to cultured rat glomerular epithelial cells (GEC) and mesangial cells (GMC) were studied. Antibodies to cultured rat GEC and GMC were produced by immunization of rabbits with GEC and GMC respectively. The rats injected with anti-GEC antibody showed a small amount of urinary protein, glomerular deposition of rabbit IgG and subepithelial dense deposits observed by electron microscopy. Proteinuria was suppressed in the rats in which complement was depleted with cobra venom factor. Western blot analysis demonstrated a band of 200 KD in GEC lysates reacted with anti-GEC antibody. The rats injected with anti-GMC antibody showed little urinary protein, glomerular deposition of rabbit IgG and mesangial dense deposits. Western blot analysis demonstrated two bands of 43 and 14 KD in GMC lysates reacted with anti-GMC antibody. These data showed that the injection of anti-GEC antibody or anti-GMC antibody induced similar lesions to passive Heymann nephritis and anti Thy 1.1 nephritis. This study suggested that antigenicity of structural glomerular cells is important as the antigens of glomerulonephritis.

Animals↗

Prognostic criteria in patients with prostate cancer: Gleason score versus volume-weighted mean nuclear volume.

Gleason's score (GS) has been reported to be the most valuable prognostic factor in cases of prostate cancer. GS is solely dependent on the histological architecture of the prostate cancer, but, it seems doubtful that histological patterns are sufficient for evaluating the degree of malignancy of prostate cancer. We previously reported that the estimation of volume-weighted mean nuclear volume (MNV) might be a more useful prognosticator for prostate cancer than subjective histological grading. However, the previous study was conducted on patients treated in a single hospital, and the number of subjects was too small to draw a definitive conclusion. In this study, we analyzed a larger number of subjects at another institution using a blinded study design. A retrospective prognostic study of 195 patients with prostate cancer diagnosed between January 1966 and December 1988 at Kyoto University Hospital, and treated by conservative therapy, was conducted. Unbiased estimates of MNV were compared with the clinical stage and histological grading according to GS with regard to the prognostic value. Univariate analysis revealed that estimates of MNV, clinical stage, and GS all correlated significantly with disease-specific survival in cases of prostate cancer. Multivariate analysis of all cases also revealed that all of these factors were significant independent prognosticators of disease-specific survival. However, focusing on clinically localized cases (stages A, B, and C), multivariate analysis revealed that the estimation of MNV was the only powerful prognosticator of prostate cancer. This study indicates that the estimation of MNV is prognostically equal or superior to GS in cases of prostate cancer. We emphasized that the estimates of MNV is a more objective method for histological grading to predict the malignant potential of prostate cancer.

Aged↗

The upper turnover site in the reentry circuit of common atrial flutter.

The upper turnover site of the reentry circuit of common atrial flutter was examined with the uses of atrial activation mapping and extrastimulus techniques during atrial flutter. The findings suggest that it is anterior to the orifice of the superior vena cava, i.e., between the superior vena cava and tricuspid annulus.

Adult↗

Characteristics of slow conduction zone demonstrated during entrainment of idiopathic ventricular tachycardia of left ventricular origin.

Idiopathic ventricular tachycardia (VT) with the right bundle branch block pattern and left-axis deviation has been shown to be due to reentry, but the property of the slow conduction zone within the reentry circuit is little understood. In 7 patients (mean VT cycle length [CL]: 361 +/- 49 ms), rapid pacing from the right ventricular outflow tract was performed during VT while recording electrograms at the early activation site in the left ventricle and at the right ventricular apex; also, conduction times from the pacing site to these recording sits (St-A and St-B intervals, respectively) were measured. Both constant fusion (except for the last paced beat) and progressive fusion were seen in all patients, indicating VT entrainment. The left ventricular site was captured orthodromically with an St-A of 394 +/- 57 ms at the pacing CL of 351 +/- 47 ms during entrainment, while the right ventricular apex was captured directly with an St-B interval of 63 +/- 19 ms. The St-A interval was gradually prolonged with the shortening of the pacing CL, whereas the St-B interval remained unchanged. VT was interrupted in all patients at the pacing CL of 279 +/- 39 ms. The effects of intravenous lidocaine (1 mg/kg) and verapamil (1 mg) were examined in 5 and 7 patients, respectively. Neither drug terminated VT but the VT-CL was increased to 369 +/- 57 ms after lidocaine (p <0.05) and to 413 +/- 69 ms after verapamil (p <0.05) (p <0.05 vs after lidocaine). The St-A interval was significantly increased after lidocaine (p <0.05) and after verapamil (p <0.05), while the St-B interval remained unchanged. A significant correlation between changes in St-A interval and VT-CL after verapamil was noted (p <0.001). In conclusion, the slow conduction zone of this VT shows tachycardia-dependent conduction delay, and the mechanism of this slow conduction involves mainly calcium channel-dependent conduction and partly depressed sodium channel-dependent conduction.

Adolescent↗

Malignant plexiform tumor of the uterus: an unusual variant of epithelioid leiomyosarcoma.

A 46-year-old woman with the complaint of hypermenorrhea underwent hysterectomy for a presumed uterine myoma. The solid tumor in the myometrium was gray in color, was 4 cm in diameter, and showed hemorrhage and necrosis. Histologically, the tumor consisted of round or polygonal cells arranged in cords and nests, and its histological features closely resembled those of plexiform tumor which has been reported as a benign, epithelioid smooth muscle tumor of the uterus. In the tumor in our patient, however, mild nuclear atypia and two to three mitoses/10 high-power fields were present. Two months after the hysterectomy, the patient was found to have metastatic foci in the lumbar vertebrae and iliac bone, which contained tumor cells with the same histological features. Accordingly, the present tumor might be interpreted as a malignant plexiform tumor of the uterus, an unusual variant of epithelioid leiomyosarcoma.

Biomarkers, Tumor↗