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T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 253 records · Page 14Linked to original sources
PubMed1999

Structure and promoter region of the surface membrane protein HS9 gene expressed on the thymic epithelial cells.

The HS9 gene encoding a surface membrane protein is expressed in thymic epithelial cells. We have isolated the mouse HS9 gene and determined the sequence of all exons. The mouse HS9 gene is composed of 14 exons spanning approx. 31 kb. Primer extension analysis identified two transcription initiation sites 33 bp and 179 bp upstream from the ATG start codon. DNA sequence analysis of the 5'-flanking region of the first exon revealed a number of consensus binding sites for known transcription factors such as GC box, Sp1, NFkappaB, gamma-IRE. Neither typical TATA nor CCAAT boxes were found in this region. These results and the analysis of the luciferase activity showed that transcription of the HS9 gene is regulated at a TATA-less promoter.

Animals↗
PubMed1999

A human cell system for detecting asbestos cytogenotoxicity in vitro.

Crocidolite, a carcinogenic asbestos in humans, specifically induces mesothelioma. We investigated the cytogenotoxic effects of crocidolite in a human mesothelioma cell line, MSTO211H, and a human promyelocytic leukemia cell line, HL60. Using confocal laser scanning microscopy, we found that the MSTO211H cells had phagocytotic activity, whereas the HL60 cells did not. In the MSTO211H cells, crocidolite decreased the cell population and increased the numbers of polynucleated cells (PN) and tetraploid cells, and increased the coefficients of variation (CV) of DNA contents in G0/G1 cells and the formation of 8-hydroxydeoxyguanosine. In contrast, crocidolite showed none of these cytogenotoxic effects in HL60 cells. To investigate the importance of phagocytosis in the cytogenotoxicity of crocidolite, we sorted the crocidolite-phagocytosed cells from less-phagocytosed cells by fluorescence-activated cell sorting, and studied the differences in cytogenotoxicity between these two cell groups. We found significant increases in the numbers of PN and tetraploid cells and the CV in the crocidolite-phagocytosed cells compared to the less-phagocytosed cells. These findings indicate that MSTO211H cells are susceptible to the cytogenotoxic effects of asbestos due to their phagocytotic activity, and that the MSTO211H cell line is suitable for the detection of such effects on human cells by asbestos and other materials which need to be phagocytosed to exert their toxicity.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1999

Tyrosine kinase involvement in apamin-sensitive inhibitory responses of rat distal colon.

1. It has been suggested that pituitary adenylate cyclase activating peptide (PACAP) may be involved in the non-adrenergic, non-cholinergic (NANC) inhibitory response of longitudinal muscle of rat distal colon. In this study, we have investigated the intracellular mechanism of PACAP-induced relaxation in this muscle. 2. PACAP induced an apamin-sensitive relaxation of the longitudinal muscle. The tyrosine kinase inhibitors genistein at 10 microM and tyrphostin 25 at 30 microM, but not the cyclic AMP-dependent protein kinase inhibitor Rp-8-bromoadenosine-3',5'-cyclic monophosphorothioate at 30 microM significantly inhibited the PACAP-induced relaxation to 60% and 25% of control values, respectively. PACAP did not increase the cyclic AMP content of the muscle. 3. Tyrphostin 25 at 10 microM significantly inhibited the relaxation of longitudinal muscle induced by electrical field stimulation (EFS), to 50% of control values. Apamin at 1 microM, an antagonist of small conductance Ca2+-activated K+ channels, also inhibited the relaxation, to 42 % of control values. The inhibitory effects of tyrphostin 25 and apamin were not additive (44 % of control values). 4. PACAP induced an apamin-sensitive, slow hyperpolarization of the cell membrane of the muscle. Tyrphostin 25 at 3 microM inhibited this PACAP-induced hyperpolarization. Tyrphostin 25 at 10 microM and genistein at 10 microM inhibited the apamin-sensitive inhibitory junction potentials induced by a single pulse of EFS. 5. The PACAP-induced relaxation of longitudinal muscle occurred with a concomitant decrease in intracellular Ca2+ levels ([Ca2+]i). Tyrphostin 25 at 10 microM and apamin at 1 microM abolished these PACAP-induced responses. 6. From these findings it is suggested that the activation of tyrosine kinase is involved in PACAP-induced relaxation of longitudinal muscle from rat distal colon, 'upstream of' the activation of apamin-sensitive K+ channels.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1999

Definitive but not primitive hematopoiesis is impaired in jumonji mutant mice.

A novel gene, jumonji was identified by a mouse gene trap strategy. The jumonji gene encodes a protein containing a putative DNA binding domain. The mice homozygous for jumonji gene with a BALB/cA genetic background show hypoplasia of the fetal liver and embryonic lethality, suggesting impaired hematopoiesis. In the peripheral blood of jumonji mutant embryos, the number of fetal liver-derived definitive erythrocytes, but not yolk sac-derived primitive erythrocytes, showed a marked reduction, suggesting that jumonji mutants die of anemia. The defects of definitive erythrocytes in jumonji mutants seemed to be caused by a decrease in the numbers of multiple hematopoietic progenitors including colony-forming unit-spleen (CFU-S) in the fetal liver. However, hematopoietic stem cells (HSCs) in the fetal liver of jumonji mutants could reconstitute the hematopoietic system of lethally irradiated recipients. In the fetal liver, the jumonji gene is expressed in fibroblastic cells and endothelial cells, but not in Lin-/c-Kit+/Sca-1(+) cells known to include HSCs. These results suggest that an environmental defect induce the impaired hematopoiesis in the fetal liver of jumonji mutant embryos.

Animals↗
PubMed1999

Accelerated rejection of Fas ligand-expressing heart grafts.

The Fas/Fas ligand (FasL) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. Recently, there has been renewed interest in immune privilege, as it was shown that two privileged sites (the eye and testes) constitutively express FasL, which kills lymphoid cells that invade these areas. We have established murine FasL-transgenic mice (B6) under the control of the cardiac alpha-myosin heavy chain promotor, and transplanted FasL-expressing F1(B6 x C3H/HeJ) heart grafts into syngeneic (F1) and allogeneic (C3H/HeJ) recipients. FasL-expressing F1 heart allografts placed in C3H/HeJ recipients as well as FasL-expressing F1 isografts placed in nontransgenic and FasL-transgenic F1 were more rapidly rejected, and their survival was much shorter than that of nontransgenic control F1 allografts placed in C3H/HeJ. Native control and FasL-expressing hearts looked normal in mice up to 8 wk of age on hematoxylin-eosin staining. Control heart allografts undergoing ordinally acute rejection showed moderate focal lymphocyte infiltrates, while FasL-expressing F1 allografts and isografts showed massive hemorrhage, edema, and massive neutrophil infiltration as early as 1 day after transplantation. In conclusion, FasL expression and surgical procedure (ischemia/reperfusion) were synergistic in the induction of accelerated heart graft rejection, while allogenicity was not necessary. It may be necessary to find ways of controlling neutrophilic reaction/apoptosis in infiltrating lymphocytes to use FasL in clinical organ transplantation.

Animals↗
PubMed1999

Further characterization of the human clear cell sarcoma cell line HS-MM demonstrating a specific t(12;22)(q13;q12) translocation and hybrid EWS/ATF-1 transcript.

Only a small number of clear cell sarcoma (CCS) cell lines have been reported, including the cell line HS-MM. In the present study, this cell line, maintained for more than 4 years since establishment, was further characterized by cytogenetic studies, fluorescence in situ hybridization (FISH) analysis, and reverse transcriptase-polymerase chain reaction (RT-PCR). HS-MM cells both in vitro and in vivo exhibited pseudodiploid karyotypes with the specific t(12;22)(q13;q12) translocation. The translocation between chromosomes 12 and 22 was confirmed by FISH analysis and the hybrid EWS/ATF-1 transcript induced by this translocation was detected by RT-PCR. The HS-MM cell line will be useful for further studies of CCS.

Chromosome Aberrations↗
PubMed1999

Relationship between the biodistributions of radioactive metal nuclides in tumor tissue and the physicochemical properties of these metal ions.

This study was undertaken to elucidate the relationship between the biodistribution of radioactive metal nuclides in tumor tissue and its physicochemical properties. Potassium analogs (86Rb, 134Cs, 201Tl) were taken up into viable tumor tissue, although 22Na concentrated in necrotic tumor tissue. 67Ga and 111In were more predominant in inflammatory tissue than in the viable and necrotic tumor tissue. 169Yb and 167Tm accumulated in viable tumor tissue and tissue containing viable and necrotic tumor tissue. 67Ga, 111In, 169Yb and 167Tm were bound to the acid mucopolysaccharide with a mol. wt. of about 10,000 daltons in the tumor tissue. 46Sc, 51Cr, 95Zr, 181Hf, 95Nb, 182Ta, and 103Ru were highly concentrated in inflammatory tissue and were bound to the acid mucopolysaccharides with a mol. wt. exceeding 40,000 daltons. 65Zn and 103Pd concentrated in viable tumor tissue and were bound to the protein in the tissue. The results suggest that the difference in intra-tumor distribution of these elements is caused by a difference in the binding substances (or status) of these elements in the tissues, and the binding substance is determined by physicochemical properties of the elements. We therefore conclude that the biodistribution of radioactive metal ions in tumor tissue is determined by its own physicochemical properties.

Animals↗
PubMed1999

Green Fluorescent Protein As a Cell-Labeling Tool and a Reporter of Gene Expression in Transgenic Rainbow Trout.

: Green fluorescent protein (GFP) has been used as an indicator of transgene expression in living cells and organisms. For testing the utility of GFP in rainbow trout, we microinjected fertilized eggs with four types of supercoiled constructs containing two variants of GFP complementary DNA (S65T and EGFP), driven by two ubiquitous regulatory elements, human cytomegalovirus immediate early enhancer-promoter (CMV) and Xenopus laevis elongation factor 1alpha enhancer-promoter (EF1). Green fluorescence was first observed at 3 days postfertilization, when the embryo was in the mid-blastula stage. Fluorescence could be detected mosaically in various types of embryonic cells and tissues of swim-up fry. Both the percentage of fluorescent cells and the fluorescence intensity of GFP-expressing cells on blastoderms, measured with a microscopic photometry system, were highest in CMV-EGFP-microinjected embryos. We conclude that GFP is capable of producing detectable fluorescence in rainbow trout, and can be a powerful tool as a cell marker and reporter gene for cold-water fish, and that analysis of GFP expression in living cells is useful for characterizing the activity of cis-elements in vivo.

Journal Article↗
PubMed1999

CD95 ligand expression enhances growth of murine renal cell carcinoma in vivo.

The CD95/CD95 ligand (CD95L) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. In this system, two murine CD95L-transfected renca clones and a control renca clone transfected only with the vector were implanted into the subcapsule of the left kidney of Balb/c and Balb/c nude mice. Both CD95L-expressing and control renca clones formed macroscopic tumors in all of the Balb/c and Balb/c nude hosts 14 days after implantation. Growth of tumors of murine CD95L-transfected renca cells was significantly better than that of control renca cells in Balb/c mice, while the growth advantage of CD95L transfectants was not observed in Balb/c nude mice. Lymphocytes underwent apoptosis mainly in the periphery of the CD95L-expressing tumors but not in control tumors grown in Balb/c mice, while lymphocytes undergoing apoptosis were not observed in CD95L-expressing tumors or in control tumors grown in Balb/c nude mice. Neutrophilic recruitment was rarely observed in CD95L-expressing or control tumors. CD95L expressed on renca cells possibly suppressed immune responses against renca tumors by inducing apoptosis of the infiltrating lymphocytes. However, CD95L-expressing renca cells did not form tumors in the renal subcapsule of allogeneic C3H/HeJ mice.

Animals↗
PubMed1999

Sun-exposure- and aging-dependent p53 protein accumulation results in growth advantage for tumour cells in carcinogenesis of nonmelanocytic skin cancer.

Three hundred and sixteen patients with nonmelanocytic skin cancer, including 46 cases of Bowen's disease (BOD), 134 cases of squamous cell carcinoma (SCC), and 136 cases of basal cell carcinoma (BCC), were examined immunohistochemically using monoclonal antibody DO-7 to assess p53 protein accumulation related to sun exposure and ageing, and growth and differentiation of skin cancer and its precursors. The rates of p53 immunostaining of BOD, SCC and BCC were 80.4%, 76.1% and 70.6%, respectively. p53-positive cells were present not only in cancer nests, but also in dysplastic and even morphologically normal epidermis adjoining cancers. Sun exposure was statistically correlated with the p53 immunostaining scores in morphologically normal epidermis of the three skin cancers and in cancer nests of SCC and BCC. The positivity and score of p53 protein often differed significantly among the three types of cancer, especially in regions of dysplasia. Interestingly, differentiation of SCC was correlated with individual p53 scores for dysplasia and cancer nests, especially for dysplasia. BOD, as the precursor of SCC, demonstrated the strongest p53 expression. Furthermore, 12.3% cases with p53 negative cancer nests showed p53-positive reaction in dysplasia and in morphologically normal epidermis. It seems that the accumulation of p53 protein plays a part in precancerous lesions and in the genesis of more highly differentiated types of skin cancer and affects mainly the growth of tumour cells rather than their differentiation. For BCC, however, age was significantly related to p53 expression. Our findings suggest that overexpression of p53 in normal skin and cancer nests of SCC and BCC is significantly related to sun exposure, that the expression of p53 in BCC is an age-dependent process, and that the early accumulation of p53 protein may be a useful predictor for the detection of nonmelanocytic skin cancer.

Adult↗
PubMed1999

DNA polymerase activity in encysting Entamoeba invadens.

Using an axenic encystation system of Entamoeba invadens as a model for E. histolytica encystation, we examined the level of DNA polymerase activity in E. invadens during encystation induced in vitro. We first characterized the DNA polymerase activity of trophozoites of E. invadens, comparing it with that of E. histolytica, and found that the activity of E. invadens was lower than that of E. histolytica at pH 2, 4, and 6 and was higher at pH 8 and 10. The activity of E. invadens was completely inhibited by high concentrations of K(-). Among inhibitors of mammalian DNA polymerases, aphidicolin and N-ethylmaleimide inhibited the activity, but 2',3'-dideoxythymidine-5'-triphosphate did not. Thus, the sensitivity of the E. invadens activity to salt and inhibitors of mammalian DNA polymerases was basically the same as that recorded for E. histolytica in our previous results. The level of DNA polymerase activity in cysts decreased as encystation proceeded as compared with that of trophozoites. The results indicate that encystation is accompanied by a reduced level of DNA polymerase activity, which correlates with the previous finding that nuclear division occurs during cyst maturation in the absence of DNA synthesis.

Animals↗
PubMed1999

Aged Budd-Chiari syndrome attributed to chronic deep venous thrombosis with alcoholic liver cirrhosis.

Budd-Chiari syndrome is a rare disease, but there are many known causes. Recent studies showed that it can be an acquired lesion resulting from thrombosis in some elderly patients. We report a 74-year-old man with Budd-Chiari syndrome attributed to chronic deep venous thrombosis and alcoholic liver cirrhosis. When he was aged 45 years, stasis ulcers of the lower extremities appeared. Cerebral infarction and left hemiparesis occurred at age 71. Ultrasonography, venacavography, and three-dimensional-magnetic resonance imaging on admission demonstrated total obstruction of the inferior vena cava with several massive thrombi and developed collateral vessels. Although the etiology of the thrombosis remained obscure, we made some speculative assumptions that chronic disseminated intravascular coagulation (which is frequently observed in cirrhosis) or hereditary coagulopathy could be involved, from his familial history of thrombotic phenomena and a severe deficiency of clotting inhibitors. Despite the high mortality of untreated Budd-Chiari syndrome reported in previous studies, this patient had been alive for about 30 years from the suspected onset.

Adult↗
PubMed1999

Real-time detection system for quantification of hepatitis C virus genome.

BACKGROUND & AIMS: For diagnosis of hepatitis C virus infection and monitoring of viral load in patients, a highly sensitive and accurate hepatitis C virus quantification system is essential. METHODS: Hepatitis C virus genome was detected by real/time detection system using an ABI Prism 7700 sequence detector (Perkin Elmer Corp./Applied Biosystems, Foster City, CA). RESULTS: As few as 10 copies of the genome were detected, and the quantification range was between 10(1) and 10(8) copies (r > 0.99). This system was 10-100-fold more sensitive than an Amplicor monitor (Roche Diagnostic Systems, Branchburg, NJ). The coefficient of variation values for both intra-assay precision and interassay reproducibility of identifying the genome quantification ranged from 0.37% to 2.00% and 0.88% to 4.66%, respectively. The system could detect the genome in 98% of patients with chronic hepatitis, 95.8% of patients with liver cirrhosis, and 100% of patients with hepatocellular carcinoma who had the antibody to hepatitis C virus, but could not detect the genome in patients without the antibody. CONCLUSIONS: The establishment of a real-time detection system enables more accurate diagnosis of infection and monitoring of viral load in interferon-treated patients via quantification of viral genome.

Carcinoma, Hepatocellular↗
PubMed1999

Semiquantitative evaluation of alpha1A-adrenoceptor subtype mRNA in human hypertrophied and non-hypertrophied prostates: regional comparison.

The main purpose of this study was to compare semiquantitatively the amount of alpha1a-adrenoceptor subtype mRNA in urethral, central and peripheral areas in benign hypertrophied prostates and non-hypertrophied prostate by the competitive reverse transcriptase polymerase chain reaction (RT-PCR) method. Prostates from twenty cases of men with benign prostatic hypertrophy (BPH) and 5 cases of bladder tumor without BPH were obtained for this study. The mRNA was extracted from the urethral, central and peripheral areas of each prostate, and quantitative RT-PCR was performed using the ratio of PCR product of alpha1a-adrenoceptor mRNA/beta2-microglobulin mRNA. The ratio for the central area of the hypertrophied prostate was significantly greater than that for the same area of the non-hypertrophied prostate (p < 0.05). In contrast, the urethral area showed no significant difference between the two prostate conditions. The central area of the hypertrophied prostate showed the tendency to have an increased alpha1a-adrenoceptor mRNA level compared with the urethral area, though no statistical difference was recognized because of the high standard error. Regional differences in the alpha1a-adrenoceptor mRNA in the non-hypertrophied prostate were rarely observed. The present finding demonstrates that the increased alpha1a-adrenoceptor mRNA content found in the hypertrophied prostate (1) was due to that in the central area.

Aged↗
PubMed1999

Is the size aftereffect direction selective?

We investigated whether the size aftereffect (apparent spatial-frequency shift after adaptation to slightly different frequencies) is direction selective; i.e., whether it is stronger for test stimuli moving in the adapting direction than the opposite direction. We used drifting sinusoidal gratings of various spatiotemporal frequencies for both adaptation and test stimuli, and the perceived test frequency was estimated by means of a matching technique with a staircase method. For the purpose of comparison, the post-adaptation threshold elevation was measured in addition to the size aftereffect. The results revealed that the direction of stimuli had no influence on the magnitude of the size aftereffect for a wide range of spatiotemporal frequencies, whereas the post-adaptation threshold elevation showed clear direction selectivity. Although there was a significant direction selectivity for the size aftereffect at low spatial and high temporal frequencies, the selectivity was much weaker than that seen in the threshold elevation data. These findings are discussed in relation to the validity of a unified account of selective adaptation at and above threshold contrast and the notion of the separate processing of pattern and motion information.

Adaptation, Psychological↗
PubMed1999

A histopathological study of the effects of pulsed Nd:YAG laser irradiation on infected root canals in dogs.

The effects of pulsed Nd:YAG laser irradiation during root canal treatment of infected teeth were investigated histopathologically in dogs. One hundred and eight teeth with a single root in 15 healthy adult beagle strain dogs were used in this study. After inducing infected teeth, each root canal was shaped with up to at least a #40 K-file; then, after coating with black ink, the canal was irradiated using the following parameters: 1 W, 30 pps, for 1 and 2 s, and 2 W, 30 pps, for 2 s. The degree of inflammation of the periapical regions at 2, 4, and 8 wk was examined histopathologically by light microscopy. Inflammation of the periapical regions in the laser-treated groups was significantly less than that in the control group at 4 and 8 wk (p < 0.05). These results suggest that pulsed Nd:YAG laser is useful for root canal treatment of infected teeth, if appropriate parameters are selected.

Animals↗
PubMed1999

Overexpression of c-Met protein in human thyroid tumors correlated with lymph node metastasis and clinicopathologic stage.

To examine the expression of c-Met protein in thyroid tumors and the correlation of c-MET protein expression with lymph node metastasis (LNM) and pathological stage, 111 papillary thyroid carcinomas (PTC), including 44 with synchronous LNM, and 117 follicular adenomas (FA) were immunohistochemically examined using dewaxed sections of formalin-fixed, paraffin-embedded tissues. Immunohistochemical results were confirmed by Western blot analysis. For PTC, positive immunostaining was observed in 107 of 111 (96.4%) cases and was diffusely present in either cytoplasm and nucleus, or only cytoplasm or only nucleus of cancer cells at varying intensities. Staining tended to be stronger in the periphery of cancer cell nests. Positive reaction was also found in 44 of 117 (37.6%) cases of FA. However, the extent and intensity of c-Met immunostaining in FA were far less than those in PTC (p < 0.0001). Forty-four PTC cases (39.6%) exhibited LNM, and the extent and intensity of c-Met expression were significantly correlated with both LNM (p < 0.0001) and pathological stage (p < 0.0001). No significant correlation of c-Met expression with age, sex or tumor size was found. Our findings suggest that PTC expresses c-Met protein much more strongly and intensively than does FA, and that strong and intense overexpression of c-Met protein may be an indicator of the presence of lymph node metastasis and advanced pathological stage of papillary thyroid carcinoma.

Blotting, Western↗