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Biomedical subjects

H Osada

Publications and source records attributed to H Osada.

At least 271 records · Page 15Linked to original sources
PubMed1988

B-cell lymphoma of probable thymic origin: case report.

A case of B-cell lymphoma of probable thymic origin is reported. A 34-year-old woman was found to have an anterior mediastinal tumor in November 1986. The surface lymph nodes were not palpable. A total resection of the tumor mass was performed. The tumor invaded the right pleura, the right lung and the pericardium. Histologically, normal thymus was found at the margin of the tumor tissue. The neoplasm was predominantly composed of large lymphoid cells, separated by rather thick fibrous bands of nodular fashion in some areas. Immunohistochemical staining demonstrated monoclonal cytoplasmic IgG and kappa chains in a small portion of the neoplastic cells in fixed tissue. The cells showed positive staining with cluster of differentiation (CD) 20 (B1) but negative staining with antibodies reactive with T-cells in unfixed tissue. "Malignant lymphoma, diffuse, large cell type (B)" was the diagnosis. The arrangements of immunoglobulin (Ig) and T cell receptor (TCR) beta genes were studied. Clonal rearrangement bands of IgH and Ig kappa genes were observed in the same sizes in both the tumor and the peripheral blood before chemotherapy. The patient received chemotherapy until September 1987, and is in complete remission at present (January 1988). The peripheral blood showed germ line patterns of IgH and Ig kappa genes in complete remission. No rearrangement bands of TCR beta genes were detected throughout. The B-cell lineage was proved both from gene arrangement analysis and with immunohistochemistry.

Adult↗
PubMed1987

Molecular evidence that SJL reticulum cell sarcomas are derived from pre-B cell. Clonal rearrangement of heavy chain but not of light chain immunoglobulin genes.

In order to investigate the clonal origin of SJL reticulum cell sarcoma (RCS), two-color cell membrane-staining and molecular biologic analyses were performed. Flow cytometric analysis revealed that the SJL RCS consists of about 50 to 60% Thy-1-positive and 20 to 30% B220-positive cells and that the majority of the Thy-1-positive cells are L3T4-positive, whereas a few are Lyt-2-positive. In spite of this pleomorphic nature of SJL RCS shown by cell membrane analysis, when the immunoglobulin heavy chain J segment (JH) was used to probe the DNA obtained from the tumor, we observed clonal rearrangements of the gene. Results of the cell-sorting experiment combined with Southern hybridization using the JH gene probe confirmed that those clonally expanding cells are Ia and B220 antigen-positive. Furthermore, all tumors derived from a given mouse showed the same rearrangement pattern. However, no clonal rearrangement was observed when the DNA was probed with the T cell receptor beta-chain gene or with immunoglobulin kappa- or lambda-light chain genes. From these data, we conclude that SJL RCS is a tumor of B cells and that the neoplastic event takes place at an immature B cell stage.

Animals↗
PubMed1987

Delayed memory dysfunction by transient hypoxia, and its prevention with forskolin.

Rats exposed to 40 min hypoxia 3 h before a one-trial learning passive avoidance task showed impaired memory retention 24 h later. this model was used to assess the ability of forskolin to restore the delayed memory dysfunction. Significant amelioration of memory retention was observed when forskolin (500 micrograms/kg, i.p.) was injected just after hypoxia. Forskolin is suggested to enhance cerebral blood flow and to facilitate memory function through the action of increased cyclic adenosine monophosphate (cAMP).

Animals↗
PubMed1987

The role of mediastinal and multi-organ CT scans in staging presumable surgical candidates with non-small-cell lung cancer.

In order to evaluate the role of CT scan and bone scan in staging patients with non-small-cell lung cancer presumably indicated for surgery, 70 consecutive patients who underwent thoracotomy were reviewed. Most of them received mediastinal and multi-organ (brain, liver and adrenal) CT scans and a bone scan. In the most recent 40 of the 70 patients, CT findings of the mediastinal lymph nodes were compared to the pathology following complete sampling. The overall accuracy of the mediastinal CT was 60.0 per cent (12 true positive and 12 true negative), but the negative predictable value was 12/(12 + 3) or 80.0 per cent, whereas 3 were false negatives though they showed an acceptable postoperative course. Sixteen out of 21 patients with one, or at the most, three enlarged nodes detected on CT also did well postoperatively and retrospectively, were considered not to have required mediastinoscopy. A group of patients showing no, or at the most, three enlarged mediastinal lymph nodes on CT may be considered as candidates for surgery even without mediastinoscopy. Multi-organ survey by means of CT was believed cost-ineffective and omittable. Bone scan however, retrospectively detected three true positives among 20 patients with a positive uptake, so that it cannot be omitted out of hand, though further examination of this point is required.

Aged↗
PubMed1987

Vectorcardiographic QRS loop in spontaneous pneumothorax.

Vectorcardiographic QRS loops were recorded in twenty-nine patients with primary spontaneous pneumothorax (SP), comprised of eighteen of left SP and eleven of right SP. The configurations of QRS loops in acute to recovery phases were compared. The patients were classified into three groups according to the degree of collapse of the lung (Group A: 25% or less, Group B: 25% to 50%, Group C: 50% or more). The major features of the QRS loop in SP were as follows: Left SP--Leftward QRS force was markedly reduced and the mean QRS axis showed a shift to the inferior and posterior. The greatest changes in the QRS loop appeared in group B. Right SP--The mean QRS axis tended to shift to the posterior and to the right. For clarifying the cause of the changes in the QRS loop, a simulation study was performed with a two-dimensional electrical field model. The results of the simulation study strongly suggested that the alterations of the QRS loop in spontaneous pneumothorax were mainly due to extracardiac reasons.

Adolescent↗
PubMed1986

[Relationships between characteristics of community and health service and activity states of medical care facilities in four regions of Fukuoka Prefecture].

In the present study, we assigned a geographical range to promote community health service planning according to the life-behavior spaces of inhabitants in Fukuoka prefecture and regarded the country-life zone, defined by the Ministry of Construction, as a region in which health services should be investigated. The social and economic characteristics of each individual region were then analyzed. As a result, four factors related to "Industrialization" and "Urbanization" were detected. Further, the states of space distribution of medical care facilities and medical care-related facilities were clarified, and relationships between the states and the above socio-economic characteristics were investigated. The states of space distribution in both facilities in Fukuoka prefecture were proved to be remarkably similar on an axis of the "Accumulation of Urbanism" factor. Moreover, Path Analysis was performed in order to clarify the patterns of treatment received by the inhabitants, and a model of these trends in relation to health care received was constructed, highlighting problems in the necessary planning of health service provision. It was specifically indicated that the problem of aging in Chikuho region would be an important factor affecting such planning in the future. We also analyzed the present state of emergency medical services in Fukuoka prefecture and the activities of health nurses in each individual region.

Catchment Area, Health↗
PubMed1986

Purification and characterization of ascamycin-hydrolysing aminopeptidase from Xanthomonas citri.

A nucleoside antibiotic, ascamycin (9-beta-[5'-0-(N-L-alanyl) sulphamoyl-D-ribofuranosyl]-2-chloroadenine), has a selective antibacterial activity against Xanthomonas species. When ascamycin was dealanylated, dealanylascamycin showed a broad antibacterial activity against various Gram-negative and Gram-positive bacteria. Xanthomonas citri is susceptible to ascamycin by virtue of the ascamycin-dealanylating enzyme on the cell surface [Osada & Isono (1985) Antimicrob. Agents Chemother. 27, 230-233]. The enzyme (Xc aminopeptidase) was purified from X. citri cells by successive DEAE-cellulose, chromatofocusing and Sephadex G-100 column chromatography to a homogeneous state. The purified enzyme exhibited a single band with an Mr of 38 000 in SDS/polyacrylamide-gel electrophoresis. Gel filtration on a calibrated column indicated a similar Mr value. The isoelectric point of the enzyme was 5.7. The enzyme catalysed the hydrolysis of the alanyl group of ascamycin and liberated alanine from the sulphamoyl nucleoside. The enzyme also catalysed the hydrolysis of L-proline beta-naphthylamide and L-alanine beta-naphthylamide. The optimal pH and temperature for enzyme activity were pH 7.5-8.0 and 35-40 degrees C respectively. The enzyme was inhibited by thiol-enzyme inhibitors (i.e. rho-chloromercuribenzoate and N-ethylmaleimide), but was not affected by various naturally occurring aminopeptidase inhibitors (i.e. amastatin, bestatin, pepstatin and leupeptin). Mn2+ and Mg2+ activated the enzyme, whereas Cu2+, Zn2+ and Cd2+ were inhibitory.

2-Chloroadenosine↗
PubMed1986

Bronchial artery aneurysm.

Two patients with bronchial artery aneurysm were surgically treated. One patient had a saccular aneurysm in the root of the left bronchial artery, and the other had a mediastinal as well as an intrapulmonary aneurysm, rupture of the latter of which had resulted in massive hemoptysis. Twelve reports of bronchial artery aneurysm have appeared in the literature to date. Those of mediastinal location frequently have symptoms mimicking dissecting aortic aneurysm, whereas their intrapulmonary counterparts usually are manifested by hemoptysis. Although its etiological process remains to be elucidated, this rare entity should be recognized in the clinical practice.

Adolescent↗
PubMed1986

Clinical evaluation of bisoprolol in the treatment of extrasystoles and sinus tachycardia: an interim report.

The effectiveness and safety of bisoprolol, a newly developed beta-adrenergic blocking drug, in the treatment of arrhythmias were evaluated in 17 patients with premature ventricular contraction (PVC), 8 with premature atrial contraction (PAC) and 7 with sinus tachycardia. More than 50% reduction of the PVC frequency was observed in 7 out of 16 patients. PVC was reduced in 2 out of 5 patients at a daily dose of 2.5 mg. The PAC frequency was decreased in 50% of the patients, and sinus tachycardia was improved in all 7 patients. Adverse reactions were observed in 8 of 32 patients. This preliminary study suggests that the antiarrhythmic effects of bisoprolol could be assessed starting at a daily dose of 2.5 mg to determine its optimal effective dose in Japanese patients.

Adrenergic beta-Antagonists↗
PubMed1986

Occurrence of an ascamycin dealanylating enzyme, Xc-aminopeptidase, in mammalian cell membranes and susceptibility to ascamycin.

An ascamycin dealanylating enzyme (Xc-aminopeptidase) has been isolated from Xanthomonas citri and characterized as a proline iminopeptidase of molecular weight of 38,000 (H. OSADA & K. ISONO, Biochem. J. 233: 459 approximately 463, 1986). Immunological studies have shown that all the mammalian cells tested possess a closely-related enzyme(s) on their cell membranes. This enzyme is more active in transformed cells than in nontransformed cells. A decreased ratio of ID50 (ascamycin/dealanylascamycin based on [35S]methionine uptake) in transformed cells compared with the nontransformed cell can be explained on the basis of the conversion of ascamycin to dealanylascamycin by the enzyme. It is suggested that ascamycin cannot be transported through mammalian cell membranes but dealanylascamycin can permeate; a similar situation exists in prokaryotic cells.

2-Chloroadenosine↗
PubMed1986

Changes in glycolytic intermediates in rat erythrocytes during exposure to simulated high altitude.

Regulatory mechanisms of erythrocyte glycolysis and 2,3-diphosphoglycerate (2,3DPG) metabolism under hypoxia were studied in rats exposed to a simulated altitude of 18,000 ft (5,486 m) for 5 d. Changes in erythrocyte glycolytic intermediates were determined by enzymatic analysis. Marked alterations of glycolytic intermediates were found during 1 d of exposure which were quite different from those observed during exposure for 2, 3, and 5 d. Alterations of intermediates seem to be highly correlated with blood pH changes; however, pH alone cannot explain the overall changes in intermediates. Results suggested that overall intermediate changes are the results of the combined effect of alterations of cellular pH and hemoglobin desaturation. Increased 2,3DPG at initial stages of exposure (within 1 d) may be caused mainly by the increased cellular pH; sustained elevation of 2,3DPG at later stages could be attributed to the relief of product inhibition of diphosphoglycerate mutase by deoxygenation.

2,3-Diphosphoglycerate↗