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Biomedical subjects

Y Hosaka

Publications and source records attributed to Y Hosaka.

At least 109 records · Page 6Linked to original sources
PubMed1992

Generation of microglial cell lines by transfection with simian virus 40 large T gene.

Microglial cells, which were isolated from a primary culture of neonatal rat brain, were transfected with temperature-sensitive simian virus 40 (SV40) large T gene by the calcium phosphate precipitation method. Four weeks after transfection, several colonies were generated, and cloned cells were characterized. One of the cloned cells (RBM129) proliferated actively at 37 degrees C and the dividing rate was significantly decreased at 40.5 degrees C. The expression of large T antigen was detected by western blotting in cells incubated at both 37 degrees C and 40.5 degrees C. The cell line showed high activity of non-specific esterase, isolectin B4 binding and phagocytosis. Also the cells were stained by ED 1 monoclonal antibody. These results indicate that these cells were derived from rat brain microglia, and immortalized by large T gene.

Animals↗
PubMed1992

Glucose modulation of aldose reductase mRNA expression and its activity in cultured calf pulmonary artery endothelial cells.

We examined the effect of glucose on aldose reductase mRNA expression and its activity in calf pulmonary artery endothelial cells. After the cells were exposed to 18 mmol/l glucose, aldose reductase mRNA expression began to increase at 6 h, reached a maximum (about 2.4-fold increase) at 12 h, and thereafter gradually decreased. Aldose reductase activity was found to strongly correlate with aldose reductase mRNA expression after cells were exposed to 18 mmol/l glucose. In contrast, aldose reductase mRNA expression was significantly decreased following exposure to 55 mmol/l glucose. Aldose reductase activity was also decreased at 24 h after 55 mmol/l glucose. The increase in aldose reductase mRNA level caused by glucose was inhibited by 1 microgram/ml of actinomycin D. These phenomena appear to be glucose-specific since neither 3-O-methylglucose nor fructose affected the levels of aldose reductase mRNA. We clearly demonstrate that aldose reductase mRNA level and its activity are modulated by glucose in calf pulmonary artery endothelial cells. Our data suggest that activation of aldose reductase in endothelial cells may contribute to the development of diabetic macroangiopathy.

3-O-Methylglucose↗
PubMed1992

Aldose reductase mRNA expression and its activity are induced by glucose in fetal rat aortic smooth muscle (A10) cells.

The induction of aldose reductase (AR) mRNA expression and its activity by glucose were investigated in fetal rat aortic smooth muscle (A10) cells. The increase in the expression of AR mRNA was observed at 6 h, and reached a maximum (2.3 fold) at 12 h after exposure to 80 mM glucose. On the other hand, increase in AR activity was observed at 12 h and reached a maximum (2 fold) at 48 h after exposure to 80 mM glucose. AR mRNA levels as well as its activity increased almost linearly in a concentration dependent manner up to 80 mM. Although not significant, there was a consistent increase in AR mRNA level and its activity at 23.75 mM glucose. There was a good correlation between AR mRNA level and AR activity. In the presence of 1 microgram/ml actinomycin D, the increase in the expression of AR mRNA level by glucose was almost completely abolished, suggesting its transcriptional regulation by glucose. Other osmolytes were also effective in inducing AR mRNA expression as well as its activity at 80 mOsm/kg. Therefore, the increase in AR mRNA level and its activity by glucose in A10 cells may be a response to the increase in osmolarity.

Aldehyde Reductase↗
PubMed1992

Transcriptional regulation of hexokinase I mRNA levels by TSH in cultured rat thyroid FRTL5 cells.

We investigated the effect of thyroid stimulating hormone (TSH) on the expression of hexokinase I mRNA by cultured rat thyroid FRTL5 cells. TSH stimulated hexokinase I gene expression in a time- and dose-dependent manner. An increase in hexokinase I mRNA was detected after 3 h of incubation with TSH, and a maximum was reached after 12 h showing about 2.5-fold increase at 1 mU/ml TSH. A nuclear run-on transcriptional assay showed that the effect of TSH on hexokinase I mRNA was due to an increase in the rate of gene transcription. (Bu)2cAMP and forskolin also increased hexokinase I mRNA expression to almost the same extent as TSH. These findings suggest that TSH stimulates hexokinase I gene expression at the transcriptional level via the cAMP-dependent pathway.

Animals↗
PubMed1992

Immunoelectron microscopy of influenza A virus neuraminidase glycoprotein topography.

Using immunoelectron microscopy, the distribution of influenza A virus neuraminidase (NA) glycoproteins was examined, after performing immunoreactions to virions on the grid. With polyclonal antibody, the immunolabels of the glycoproteins were found to be homogeneously distributed, whereas with monoclonal antibody they were found to be distributed in clusters. After destruction of haemagglutinin (HA) but not of NA activity with a high concentration of trypsin, the remaining visible spikes were evenly distributed. This finding was consistent with the absence of immunolabelling with anti-HA antibody, and the homogeneous pattern of immunolabels with anti-NA polyclonal antibody, but not with the clustered labelling with the anti-NA monoclonal antibody. Thus, the immunolabelling image with anti-NA polyclonal antibody was considered to reflect the true one.

Antibodies, Monoclonal↗
PubMed1992

The regulation of two distinct glucose transporter (GLUT1 and GLUT4) gene expressions in cultured rat thyroid cells by thyrotropin.

We investigated the glucose transporter mRNAs expressed in FRTL5, a rat thyroid cell line, and their regulation by TSH by means of the polymerase chain reaction. FRTL5 cells as well as rat thyroid tissue expressed three types of glucose transporter mRNAs: GLUT1 or erythrocyte/HepG2/brain isoform, GLUT2 or pancreatic beta-cell/liver isoform, and GLUT4 or muscle/fat isoform. GLUT1 mRNA predominated, GLUT4 mRNA was minor, and GLUT2 mRNA expression was faint. Incubation of FRTL5 cells with TSH induced a time- and concentration-dependent increase in GLUT1 mRNA levels, while GLUT4 mRNA levels were decreased. The response of GLUT1 mRNA to TSH was evident at 3 h, and the maximal response was achieved at 12 h. TSH at a dose of 1 mU/ml elicited an approximately 3-fold increase in GLUT1 mRNA levels. (Bu)2cAMP (1 mM), 8-bromo-cAMP (1 mM), and forskolin (50 microM) mimicked the effect of TSH on GLUT1 and GLUT4 mRNA levels. The increase in GLUT1 mRNA by TSH was correlated with the increase in GLUT1 protein and the increase in 2-deoxyglucose transport activity. These observations suggest that in thyroid cells, TSH stimulates glucose transport at least in part by enhancing GLUT1 gene expression, and that the effect of TSH on GLUT1 and GLUT4 mRNA levels is mediated by a cAMP-dependent pathway.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1992

Assessment of the molluscicidal activities of Tribromosalan, Cartap and Chlorothalonil against Oncomelania hupensis.

Molluscicidal activities of Tribromosalan, Cartap and Chlorothalonil were evaluated in the laboratory and the field against Oncomelania hupensis, the intermediate host of Schistosoma japonicum in China. The three chemicals were very effective against O. hupensis in the laboratory. The molluscicidal activities found in the field trials suggest that Tribromosalan and Cartap may be used as practical molluscicides. Dosage of 10 g/m2 of Tribromosalan in spring only and 20 g/m2 of Cartap in both spring and autumn would be recommendable as practical mollusciciding doses for the control of O. hupensis.

Animals↗
PubMed1992

[DNA ploidy pattern of flow cytometry as indicator of malignancy and prognosis in bladder cancer].

Flow cytometry (FCM) of bladder cancer has unique characteristics. First, bladder washing is a suitable material to measure in terms of single cell suspension, while the urine appears inadequate because of the low sensitivity for detecting bladder cancer. Second, the role of FCM depends on the different features of superficial, in situ or invasive bladder cancer. In superficial cancers, FCM can detect the presence of cancer, predict intravesical recurrence and evaluate the response of intravesical instillation therapy. In carcinomas in situ, frequent occurrence of polyclonal aneuploid may indicate the aggressive nature of high grade malignancy. Early removal of bladder may be endorsed unless BCG instillation is effective. For invasive cancers, FCM does not seem to be so useful, but FCM relates well to other prognostic parameters.

Carcinoma, Transitional Cell↗
PubMed1992

Morphological estimation of total number of influenza A type virion spikes.

When purified and stored influenza A type virions were observed by the negative staining method in electron microscopy, we found disintegrated virions associated with a population of dispersed but clustered spikes. The total spike numbers of the clusters were morphologically counted, and their peak number (about 200) was consistent with the spike number measured by the molecular biology method, described in the other report.

Influenza A virus↗
PubMed1991

Regulation of the human T-cell response to Schistosoma japonicum egg antigen by concomitant cellular and humoral mechanisms in vitro.

Serum-mediated regulation of T-cell responses specific for soluble egg antigen (SEA) of Schistosoma japonicum was tested in human hosts. When we added autologous serum to SEA-specific human T-cell lines (CD3+, 4+, 8-), we observed suppression of T-cell proliferation, and this suppressive activity was detected in the immunoglobulin-G2 (IgG2) subclass. Suppression was dose-dependent and antigen-specific. T-cell proliferation induced by only one SEA fraction of greater than 18 kDa was modulated in the presence of 100 micrograms/ml autologous as well as allogeneic infected IgG2. This SEA fraction-driven proliferation was also regulated by suppressor T-cells through distinct suppressive mechanisms. Our results suggest that T-cell responses to a particular component(s) of SEA are strictly regulated through both cellular and humoral mechanisms in human chronic S. japonicum infection.

Animals↗
PubMed1991

Haemodynamic changes during the apnoea test for diagnosis of brain death.

Haemodynamic responses to the apnoea test for the diagnosis of brain death were investigated in nine patients with severe head injury or cerebrovascular disease. To prove apnoea, the ventilator was disconnected for ten minutes and oxygen was insufflated to avoid hypoxaemia. No respiratory movement was seen in any patient. Ten minutes after disconnecting the ventilator, PaCO2 was increased to 78 +/- 3 mmHg and pH was reduced to 7.17 +/- 0.02. Adequate oxygenation was maintained in all patients. Cardiac output increased from 4.8 +/- 0.7 to 5.7 +/- 0.8 L.min-1 (P less than 0.05), and mean pulmonary artery pressure increased from 11 +/- 1 to 17 +/- 2 mmHg (P less than 0.01). However, mean arterial pressure, heart rate, pulmonary artery wedge pressure and right atrial pressure did not change. Plasma catecholamines were measured in three patients. Plasma norepinephrine concentrations increased in all three patients but the changes in plasma epinephrine were minimal. These circulatory responses to acute hypercapnia were less than those reported in awake volunteers and in patients during general anaesthesia. However, since plasma norepinephrine concentration increased during the test, some sympathoadrenal response, probably of spinal origin, was present, and may have prevented the direct depressant circulatory effects of acute hypercapnia. In conclusion, the apnoea test did not produce haemodynamic disturbances when respiratory acidosis was limited to a pH 7.17 +/- 0.02 and PaCO2 60-80 mmHg.

Adult↗
PubMed1991

The contour lines of the upper lip and a revised method of cleft lip repair.

Many techniques for cleft lip repair have been reported, but these techniques do not consider the contour lines of the upper lip and, in fact, destroy them. The upper lip has complicated contour lines including the vermilion free margin, vermilion border, upper lip horizontal groove (upper lip groove), philtrum (dimple and columns), nostril sills, and nasolabial grooves. Incision lines should be designed so that the postoperative scars do not cross these contour lines. We feel that our incision lines and postoperative scars provide better aesthetic results and diminish hypertrophic scar formation.

Child, Preschool↗
PubMed1991

Flow cytometric DNA histograms of paraffin-embedded pheochromocytomas.

We proposed a new classification of pheochromocytomas according to DNA ploidy patterns. Proliferation index (PI = S% + 4C%) might be an alternative to 4C% which was used as a critical marker of DNA nonaneuploid histograms. The follow-up survey revealed that DNA tetraploid with minimum increase of PI could not rule out the substantial possibility of malignancy and the comparison of DNA diploid histograms disclosed that 22 and 0% showed significant increase of the ratio of 4C% to S% under PI and 4C% criteria, respectively. In conclusion, 4C% was more effective and reliable than PI in order to classify DNA nonaneuploid pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1991

Binding of viral glycoprotein with trypsin and its relation to virulency. II. Comparison between bovine and Streptomyces griseus trypsins.

The two step nature of the binding reaction between trypsin and viral glycoproteins was further investigated using two types of trypsin, bovine trypsin and Streptomyces griseus trypsin. The experimental results were explained by the van der Waals energy operating in the second step, suggesting that the conformational aspects, in addition to the electrostatic nature, of the interacting peptides are decisive in this specific process.

Amino Acid Sequence↗
PubMed1991

Operations for microforms of cleft lip.

Microform cleft lip is a mild expression of cleft lip and may be difficult to repair. Its severity may be defined by the degree of downward depression of the nostril rim, skin striae of the upper lip, notching of Cupid's bow, and deformity of the vermilion border. Variation in surgical repair is reported for each type of microform cleft lip.

Cleft Lip↗
PubMed1991

[Lymphocytic subsets of tumor tissue, non tumorous kidney, and the peripheral blood in primary renal cell carcinoma].

Lymphocyte subsets were examined in renal cell carcinoma (TILs), adjacent non-tumor renal tissue and peripheral blood (PBLs) by flow cytometry and histochemistry in eighteen patients with renal cell carcinoma. CD5-positive cells were predominant in the TILs in 14 patients. In the renal cell carcinoma tissue, CD8-positive cells were predominant over CD4-positive cells, resulting in a less than unity ratio of CD4/CF8-positive cells. The lymphocyte number was significantly in adjacent normal renal tissue than in renal cell carcinoma. However, lymphocyte subsets ratios were not significantly different between these two tissues. PBLs showed the same proportions (CD4/CD8 mean 1.9 +/- 0.8) as the previously published healthy controlled data. The proportions of CD8-positive cells were significantly increased (p less than 0.05) and those of CD4-positive cells were also significantly decreased (p less than 0.01) in the TILs. The infiltrating pattern of TILs in 17 patients was divided histochemically into cluster (N = 7), single (N = 4), and mixed types (N = 6). The cluster and mixed types were significantly more common in grade 1 tumors and the single type was more common in the grade 2 tumors (p less than 0.05). The pT3 tumors showed the single type of TIL infiltration pattern, but showed no significant difference. In the cluster pattern of TILs, CD8-positive cells were surrounded by CD4-positive cells. Non-tumorous kidneys showed no infiltration of lymphocytes, except in 2 patients of pyelonephritis. These results suggest that cytotoxic T-cells stained as CD8 play an immunoreactive role against renal cell carcinoma.

CD4-CD8 Ratio↗
PubMed1991

[Lectins expression of parathyroid glands with primary hyperparathyroidism].

The binding sites of lectins in parathyroid glands were determined by an immunohistochemical method in normal parathyroid gland, hyperplasia, adenoma and carcinoma, the used lectins were commercially available Glycine max (SBA), Concanavalin enciformis (Con A), Triticum vulgaris (WGA), Richinus communis (RCA), Banderiaea simplicifolia II (BSA II) and Arachis hypogaea (PNA). For normal parathyroid glands (2 cases) and hyperplasia (2 cases), WGA and BSA II were stained in cytoplasma and cell membrane. For carcinoma (1 cases), all lectins but BSA II were positively stained. In particular, SBA revealed more stronger stain than any other hystological types. From the staining patterns of lectins, it was suggested that adenomas (22 cases) be divided into one group similar to carcinoma and the others to normal parathyroid gland and hyperplasia. But there was no difference in clinical data of patients between the two groups.

Adenoma↗