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M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 19 recordsLinked to original sources
PubMed1992

Age-associated increase in number of CD4+CD8+ intestinal intraepithelial lymphocytes in rats.

A significant number of CD4+CD8+ T cells were detected in intestinal intraepithelial lymphocytes (IEL) of various strains of rats including Wistar, WKA, BN, LEW and F344. The site of the CD4+CD8+ population in IEL increased with age in all strains we examined. Most IEL bearing CD8 expressed no CD5 antigen in young rats, while all CD4+CD8+ IEL and some of CD8+ IEL in aged rats were of CD5+CD45RB- phenotype. In germ-free Wistar rats, age-associated increase in the number of CD4+CD8+CD5+ IEL was not evident, indicating that stimulation by the intestinal microflora was important for expansion of the CD4+CD8+CD5+CD45RB- IEL. Aged athymic F344 nude rats contained appreciable numbers of CD4+ IEL and CD8+ IEL but few CD4+CD8+ IEL, suggesting that the CD4+CD8+ IEL may be derived from thymus-dependent populations. Unlike a majority of CD4+CD8+ thymocytes bearing a low intensity of CD3/T cell receptor (TcR) alpha/beta, the CD4+CD8+ T cells in IEL expressed a high intensity of CD3/TcR alpha/beta on their surface. The CD4+CD8+ IEL appear to contribute to the spontaneous proliferation of the IEL in aged rats as assessed by tritiated thymidine incorporation after in vitro culture with medium only. These results suggest that with aging a unique CD4+CD8+ IEL may expand at a local site of the intestine under the influence of intestinal microflora and may contribute to the first line of defense against various pathogens in the epithelium.

Age Factors↗
PubMed1992

Specific expressions of Fyn and Lyn, lymphocyte antigen receptor-associated tyrosine kinases, in the central nervous system.

The Src-like protein-tyrosine kinases Fyn and Lyn are expressed in lymphocytes. Fyn is expressed in T cells at elevated levels and is associated with the T cell antigen receptor complex, whereas Lyn is expressed in B cells and is associated with membrane-bound immunoglobulin. Thus, these kinases are suggested to participate in antigen-mediated signal transduction in lymphocytes. Previous report showed that fyn was also expressed in brain, but its cellular distribution was not examined. Expression of Lyn in neural tissues was not previously reported. Here we report that both fyn and lyn are expressed in discrete regions of the brain. To throw light on their functions in the brain, we investigated their expressions during brain ontogenesis in mice. In situ hybridization analysis showed that Fyn mRNA was specifically expressed in neurons of embryos and newborn mice. In adult animals, fyn mRNA was expressed in oligodendrocytes as well as neurons. In contrast, the expression of lyn mRNA was relatively low in brains of embryos and newborn mice, but in adults the transcript was specifically expressed in the granular layer of the cerebellum. Therefore, the Fyn and Lyn kinases may regulate distinct functions of specific cells during brain development. The specific expressions of Fyn and Lyn in both lymphatic and neural tissues could suggest common signalling mechanisms in the immune system and central nervous system.

Animals↗
PubMed1992

Rat thymic epithelium positively selects mouse T cells with specificity for rat MHC class II antigens but fails to induce detectable tolerance in the mouse T cells to the rat MHC antigens.

BALB/c (H-2d) nude mice were grafted with allogeneic AKR/J (H-2k) or xenogeneic (ACI-N rat, RT1av1) fetal thymuses which were depleted of hemopoietic cells by incubating with 2'-deoxyguanosine (2'dGuo) in vitro prior to grafting. The nylon-wool-passed LN T cells from nude mice grafted with 2'dGuo-treated AKR/J thymus showed a poor proliferative response to B10BR (H-2k) stimulator cells, confirming that mouse thymic epithelium has the capacity to induce tolerance against the mouse MHC antigens on the thymic epithelium. On the other hand, the nylon-wool-passed LN T cells from nude mice grafted with untreated or 2'dGuo-treated ACI/N rat thymus showed significant proliferative responses to ACI/N, which can be blocked by anti-rat MHC class II mAb, whereas the nylon-wool-passed LN T cells from nude mice grafted with syngeneic thymus hardly responded to the xenogeneic stimulator cells. These results suggest that rat thymic stromal cells including thymic epithelium can not induce detectable tolerance in mouse T cells to rat MHC antigens; but rat thymic epithelium may positively select mouse T cells with specificity for rat MHC class II antigens, resulting in a mouse T cell repertoire with strong xeno-reactivity.

Animals↗
PubMed1992

Cytokine-related immunopotentiating activities of paramylon, a beta-(1-->3)-D-glucan from Euglena gracilis.

Paramylon, a beta-(1-->3)-D-glucan, isolated from Euglena gracilis, was tested for its adjuvant activity on the antibody response to sheep red blood cell (SRBC) in mice. Paramylon markedly enhanced anti-SRBC plaque-forming cell production at a dose of 10 mg/kg. It was also found that in vitro addition of lipopolysaccharide in culture to macrophages from paramylon-treated mice produced a large amount of interleukin 1 (IL-1) and there was a significant level of interleukin 6 (IL-6) induced transiently in the blood of these mice. As IL-1 and IL-6 play crucial roles in the immune response to T cell-dependent antigens like SRBC, the immunopotentiating effect of paramylon might be expressed through the action of these cytokines.

Adjuvants, Immunologic↗
PubMed1992

[Effects of self-efficacy and outcome expectation on observational learning of altruistic behavior].

The purpose of the present study was to examined the hypothesis that the effects of observational learning of altruistic behavior are related to personal viewpoint, self-efficacy, outcome expectation, and other factors. One hundred and fifty-five fourth-grade school children were assigned randomly to four conditions; distress viewpoint, outcome expectation, altruistic behavior, or non-observational control. After observational learning, the students were immediately administered the generalization test of altruistic behavior, empathy, reward and punishment expectations, and rating tests of self-efficacy belief. It was found that; (a) altruistic behavior and outcome expectation conditions had significant learning effects, (b) self-efficacy was able to predict altruistic response in the altruistic behavior viewpoint condition, and (c) from an outcome expectation viewpoint, altruistic behavior toward peers and adults related to punishment expectation, whereas social sharing was related to reward expectation. According to these findings, an observational learning model of altruistic behavior was proposed.

Altruism↗
PubMed1992

[Expression of angiotensin II receptor on BALF macrophages from patients with sarcoidosis and healthy individuals].

We previously reported that angiotensin II (A-II) enhanced the accessory function of BALF macrophages in some patients with sarcoidosis. We hypothesized that this finding was mediated by the A-II receptor on BALF macrophages. From this viewpoint, we investigated the expression of A-II receptor on BALF macrophages. The binding of 125I-A-II to BALF macrophages was specifically inhibited by unlabeled A-II when incubated for 1 hour at 37 degrees C. However, the uptake of 3H-inulin to BALF macrophages was not inhibited by unlabeled inulin under the same conditions. These findings indicate that the binding of 125I-A-II to BALF macrophages was mediated by the putative A-II receptor, and was not due to pinocytosis.

Adult↗
PubMed1992

[A case of pulmonary atypical mycobacteriosis complicated with aplastic anemia, treated with surgical resection and postoperative sparfloxacin].

A few weeks after treatment with INH, RFP and SM, severe aplastic anemia developed in a 49-year-old man with pulmonary atypical mycobacteriosis due to M. kansasii. All drugs were discontinued immediately after bone marrow examination revealed severely hypoplastic marrow, but pancytopenia continued for several months. Although M. kansasii was sensitive to other drugs including CS and TH, these two drugs were also discontinued because of their respective psychiatric and hepatic adverse effects. Ofloxacin (OFLX), to which M. kansasii was sensitive, was administered without clinical improvement and complete resistance to OFLX developed after several months treatment. Right upper and middle lobectomy and S6 partial lobectomy was performed, and postoperative sparfloxacin (SPFX) administration resulted in cure of the disease. Drug sensitivity testing revealed that the organism had acquired resistance to OFLX, but was still sensitive to SPFX. Thus, SPFX appears to be an useful drug for the treatment of atypical mycobacteriosis.

Anemia, Aplastic↗
PubMed1991

Primary culture and cryopreservation of mouse astrocytes under serum-free conditions.

The methods of primary culture and cryopreservation of mouse astrocytes under serum-free conditions were examined. Cerebra from newborn C3H/He mice were employed as the source of astrocytes. The cultured cells were able to grow in a serum-free, chemically defined medium containing transferrin, hydrocortisone, biotin, sodium selenite, insulin, fibroblast growth factor and epidermal growth factor. After the culture was maintained in the medium for 3 weeks, purity was assessed using immunofluorescence staining. The great majority of the cells (greater than 98%) contained glial fibrillary acidic protein and S-100 protein which are cell markers of astrocytes. To cryopreserve the enriched astrocytes under serum-free conditions, various cryoprotectants were examined. The combination of 10% dimethylsulfoxide and 0.1% methylcellulose gave the highest survival rate. These methods of primary culture and cryopreservation will be useful in physiological and biochemical studies which require mouse astrocytes.

Animals↗
PubMed1991

Expression of fibronectin and laminin by different types of mouse glial cells cultured in a serum-free medium.

The expression of fibronectin and laminin by cultured glial cells was studied. The glial culture from neonatal mouse cerebra maintained in a chemically defined, serum-free medium consisted of type-1 astrocytes, oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells, oligodendrocytes and type-2 astrocytes. Double-labelling immunofluorescent experiments performed using the mixed glial culture indicated that fibronectin and laminin are expressed in different patterns among the glial subtypes. The staining intensities with anti-fibronectin or anti-laminin antibodies decreased in the order: type-1 astrocytes, O-2A progenitor cells and type-2 astrocytes. Both molecules were deposited in a fibrillar matrix underneath type-1 astrocytes, whereas only intracytoplasmic localization of these molecules was observed with O-2A progenitor cells and type-2 astrocytes. Western blot analysis showed that glial fibronectin has a slightly higher molecular weight than mouse plasma fibronectin (230 kDa) and that glial laminin is a variant with a 220 kDa B chain present and the 400 kDa A chain missing. Using enzyme-linked immunosorbent assays (ELISA), these molecules were detected in the glial extracellular matrix at the concentration of 4 ng/10(6) cells. A large amount of fibronectin (82 ng/10(6) cells) was secreted into the culture medium, while secretion of laminin was not detected.

Animals↗
PubMed1991

Effect of NGF-2 on the survival of chick sensory ganglion neurons in vitro.

The biological activity of NGF-2, the third member of the NGF family, was investigated. Conditioned medium of COS cells transfected with expression plasmid for human NGF-2 cDNA promoted the survival of sensory neurons from dorsal root ganglia (DRG), and nodose ganglia (NG). Supernatant of mock transfected COS cells was less effective for the survival of DRG neurons and ineffective for the survival of NG neurons. These results suggest that NGF-2 is a novel neurotrophic factor whose biological activity is distinct from NGF.

Animals↗
PubMed1991

Properties of a cell line (MEG-01SSF) of human megakaryoblastic leukemia cells.

MEG-01SSF cells were prepared from MEG-01S by conditioning in a chemically defined, serum-free medium. The cells grew well in the medium and required transferrin for growth. Doubling time was about 20 hours. The cells retained GpIIb/IIIa as a marker of megakaryocytes and transferrin receptors on the cell surface. Some of the cells in the stationary phase of growth produced platelet-like particles, which bore characteristic microtubule rings.

Antigens, Surface↗
PubMed1979

[Ergometer test].

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Exercise Test↗
PubMed1979

Relation of pancreatic duct hyperplasia to carcinoma.

In order to find a relationship between ductal hyperplasia and carcinoma of the pancreas, histological and histochemical examinations were made on pancreatic specimens of 1,174 autopsy patients with special attention to the age incidence of the former. Ductal hyperplasia was divided into 3 types; nonpapillary, papillary, and atypical hyperplasia. All three types of hyperplasia and ductal carcinoma showed a similar tinctorial property in mucous histochemistry. In general, atypical hyperplasia was seen in the pancreas having papillary hyperplasia which was found in the pancreas associated with nonpapillary hyperplasia. All three types of hyperplasia were apparently more frequent in cancerous pancreases than in non-cancerous ones. They were also more common in the head of the pancreas than in the body and tail. Age incidence also suggests a sequential change from nonpapillary hyperplasia through papillary and atypical ones to carcinoma.

Adolescent↗
PubMed1979

Quantitative flash-methylation analysis of phenobarbital.

In phenobarbital measurement by GLC with the flash-methylation technique, using trimethylanilinium hydroxide as a methylating reagent, a small amount of water decomposed phenobarbital and interfered with the quantitative analysis. Thus, both the sample and the methylating reagent must be sufficiently dehydrated to attain quantitative analyses. The hydrolysis decomposition product of phenobarbital was N-methyl-2-phenylbutyramide, as shown by its mass spectrum. The sum of methylated phenobarbital and N-methyl-2-phenylbutyramide (if observed in the spectrum) can be used for an accurate phenobarbital assay in the present flash-methylation technique.

Chromatography, Gas↗