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H Tashiro

Publications and source records attributed to H Tashiro.

At least 55 records · Page 3Linked to original sources
PubMed2000

Mouse Peg9/Dlk1 and human PEG9/DLK1 are paternally expressed imprinted genes closely located to the maternally expressed imprinted genes: mouse Meg3/Gtl2 and human MEG3.

BACKGROUND: Genomic imprinting significantly influences development, growth and behaviour in mammals. Systematic screening of imprinted genes has been extensively carried out to identify the genes responsible for imprinted phenotypes and to elucidate the biological significance of this phenomenon. In this study, we applied DNA chip technology for isolating paternally expressed imprinted genes (Pegs). We compared the resulting expression profiles of parthenogenetic and fertilized control embryos to identify novel imprinted genes. RESULTS: A novel paternally expressed mouse imprinted gene, Peg9/Dlk1, was identified. Consistent with this finding, the paternal expression of its human homologue, PEG9/DLK1, was also confirmed. These two genes form imprinted gene clusters with the reciprocally imprinted mouse Meg3/Gtl2 and human MEG3 genes that we first identified on distal chromosome 12 and chromosome 14q32, respectively. CONCLUSIONS: As DNA chip technology allows us to quickly screen a large number of genes, using this technology to search for imprinted genes could accelerate the identification of genes responsible for human and mouse genetic diseases. Dlk1 and DLK1, which encode transmembrane proteins, have six EGF-like repeats and show homology to the Delta gene in Drosophila melanogaster. Because of its homology to mammalian Delta homologues, PEG9/DLK1 may contribute to the scoliosis phenotype observed in maternal uniparental disomy 14 (mUPD14) patients.

Animals↗
PubMed2000

RIKEN integrated sequence analysis (RISA) system--384-format sequencing pipeline with 384 multicapillary sequencer.

The RIKEN high-throughput 384-format sequencing pipeline (RISA system) including a 384-multicapillary sequencer (the so-called RISA sequencer) was developed for the RIKEN mouse encyclopedia project. The RISA system consists of colony picking, template preparation, sequencing reaction, and the sequencing process. A novel high-throughput 384-format capillary sequencer system (RISA sequencer system) was developed for the sequencing process. This system consists of a 384-multicapillary auto sequencer (RISA sequencer), a 384-multicapillary array assembler (CAS), and a 384-multicapillary casting device. The RISA sequencer can simultaneously analyze 384 independent sequencing products. The optical system is a scanning system chosen after careful comparison with an image detection system for the simultaneous detection of the 384-capillary array. This scanning system can be used with any fluorescent-labeled sequencing reaction (chain termination reaction), including transcriptional sequencing based on RNA polymerase, which was originally developed by us, and cycle sequencing based on thermostable DNA polymerase. For long-read sequencing, 380 out of 384 sequences (99.2%) were successfully analyzed and the average read length, with more than 99% accuracy, was 654.4 bp. A single RISA sequencer can analyze 216 kb with >99% accuracy in 2.7 h (90 kb/h). For short-read sequencing to cluster the 3' end and 5' end sequencing by reading 350 bp, 384 samples can be analyzed in 1.5 h. We have also developed a RISA inoculator, RISA filtrator and densitometer, RISA plasmid preparator which can handle throughput of 40,000 samples in 17.5 h, and a high-throughput RISA thermal cycler which has four 384-well sites. The combination of these technologies allowed us to construct the RISA system consisting of 16 RISA sequencers, which can process 50,000 DNA samples per day. One haploid genome shotgun sequence of a higher organism, such as human, mouse, rat, domestic animals, and plants, can be revealed by seven RISA systems within one month.

Animals↗
PubMed2000

Coronary microvascular abnormality in the reversible systolic dysfunction observed after noncardiac disease.

Acute reversible left ventricular wall motion abnormalities mimicking myocardial stunning have been reported with noncardiac disease and their coronary angiograms did not demonstrate organic stenosis or vasospasm in the epicardial coronary arteries. Thus, this mechanism has not yet been fully clarified. Two patients are reported as demonstrating acute reversible wall motion abnormalities after noncardiac disease. The electrocardiographic and echocardiographic findings mimicked myocardial stunning and confirmed the previous reports. The coronary angiograms did not show any corresponding coronary stenosis or vasospasm, but did show a reduced coronary flow reserve. Cardiac metaiodobenzylguanidine scintigraphy demonstrated regional defects involving the apex, a decreased heart/mediastinum ratio and an enhanced washout rate, which partially returned to normal after 3 months. Microvascular dysfunction and sympathetic nervous abnormalities might be responsible for the reversible contractile impairment.

3-Iodobenzylguanidine↗
PubMed2000

Two regions of homozygous deletion clusters at chromosome band 9p21 in human lung cancer.

We examined 149 lung cancer cell lines for homozygous deletions using 24 DNA markers, which were mapped and ordered in chromosome band 9p21, to define the target regions for 9p21 deletions in human lung cancer. Homozygous deletions were detected in 39 (26%) cell lines and clustered at 2 independent regions. One was the region containing the p16/CDKN2A tumor suppressor gene, and this region was deleted in 32 (21%) cell lines. The other was the region containing D9S171, which is the locus approximately 3 Mb proximal to the CDKN2A locus. This region, designated as the D9S171 region, was deleted in 18 (12%) cell lines. Seven of the 18 cell lines had identical minimum deletions of a 17,036 bp sequence located 20 kb distal to the D9S171 locus. However, such a deletion was also observed in the corresponding B-lymphoblastoid cell line from 1 of the 7 cell lines and in 5 (16%) of 32 noncancerous tissues, suggesting that the deletion was a genetic polymorphism. By considering this polymorphism, 11 (7%) cell lines still had deletions at the D9S171 region. Two NSCLC cell lines showed deletions at the D9S171 region and retentions of the CDKN2A locus. Furthermore, an NSCLC cell line showed discontinuous deletions including either the CDKN2A or D9S171 locus. Therefore, the region surrounding the D9S171 locus was defined as another target region for the 9p21 deletions. It is possible that unknown tumor suppressor gene(s) are present in this chromosomal region. Genes Chromosomes Cancer 27:308-318, 2000.

Carcinoma, Non-Small-Cell Lung↗
PubMed2000

[Efficacy of UFT in the treatment of para-aortic lymph node metastasis following gastric cancer surgery: case report].

The patient was a 68-year-old man who underwent pyloric gastrectomy for advanced stomach cancer on December 6, 1996. The histopathological diagnosis was poorly differentiated adenocarcinoma, ss, ly3, v1, n2 (+), and stage IIIa. Postoperative adjuvant chemotherapy consisted of short-term intravenous infusion of 5-FU, 320 mg/m2/day (= 480 mg/body) for 5 days beginning on postoperative day (POD) 1, and oral 5-FU, 200 mg/day, for 1 year beginning on POD 14. The preoperative CEA value was 316.2 ng, but it fluctuated below 10 ng postoperatively. About one year after the operation, the patient began to complain of epigastric pain, loss of appetite, and general malaise. CT of the upper abdomen revealed a 1.5-cm para-aortic lymph node, and the CEA value of 319.0 ng was abnormally high. 5-FU was stopped, oral UFT at 300 mg/day was started, and the patient's course was followed. Three months after the start of UFT, the lymph node had shrunk on CT (shrinkage rate: 66.7%), and the CEA value had decreased to 14.3 ng. As though corresponding to these changes there was a gradual decrease in the epigastric pain, general malaise, etc., and the patient's appetite also returned. There were no subsequent elevations in the CEA values or increases in the size of the para-aortic lymph nodes, and the patient's general condition was favorably maintained. UFT appeared to be effective against the lymph node metastasis around the aorta in this case.

Adenocarcinoma↗
PubMed2000

Study on eight patients with malignant tumors after renal transplantation.

The high incidence of cancer after renal transplantation is now a critical concern since the graft survival rate has been improved extensively. We experienced 9 malignancies in 8 patients out of 168 recipients up to December 31, 1999 in our hospital, consisting of a case of gastric plasmacytoma and cases of cancer in the liver (2), thyroid (2), prostate (1), breast (1), sigmoid colon (1) and gall-bladder (1). Two patients were diagnosed as having tumors within 3 months after transplantation, suggesting post-transplant acceleration of growth of the latent tumors. The other patients were diagnosed at an average of 128 months, ranging from 84 to 263 months after transplant. Two patients died of gastro-intestinal bleeding and acute heart failure. Four patients died directly of progressive neoplasm within 3 months after diagnosis. These results suggest that the course of malignancies developing in post-transplant recipients is more aggressive than that expected in non-transplant patients, and it is very important to intensively follow long-term surviving cases to detect the malignant tumors as early as possible.

Adolescent↗
PubMed2000

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group].

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

Anti-Infective Agents↗
PubMed1999

One- and two-photon-induced fluorescence from recombinant green fluorescent protein.

The fluorescence spectral properties of recombinant green fluorescent protein (rGFP) were examined with one- and two-photon excitations using femtosecond pulses from a Ti:sapphire laser. Intensity-dependent properties of the two-photon-induced fluorescence from rGFP excited by an 800-nm, 100-fs laser beam were reported, and the two-photon excitation cross section of rGFP was measured at 800 nm as about 160 x 10(-50) cm(4)s/photon. The possible excited-state proton transfer between two electronic states at about 400 nm in protonated (RH) species and 478 nm in deprotonated (R(-)) species in rGFP was confirmed by fluorescence and fluorescence excitation anisotropy spectra. A subelectronic state (or vibronic progression) at about 420 nm in RH species was identified, which was relatively stable and not involved in the excited state proton transfer in rGFP upon irradiation.

Anisotropy↗
PubMed1999

Molecular dynamics of MHC genesis unraveled by sequence analysis of the 1,796,938-bp HLA class I region.

The intensely studied MHC has become the paradigm for understanding the architectural evolution of vertebrate multigene families. The 4-Mb human MHC (also known as the HLA complex) encodes genes critically involved in the immune response, graft rejection, and disease susceptibility. Here we report the continuous 1,796,938-bp genomic sequence of the HLA class I region, linking genes between MICB and HLA-F. A total of 127 genes or potentially coding sequences were recognized within the analyzed sequence, establishing a high gene density of one per every 14.1 kb. The identification of 758 microsatellite provides tools for high-resolution mapping of HLA class I-associated disease genes. Most importantly, we establish that the repeated duplication and subsequent diversification of a minimal building block, MIC-HCGIX-3.8-1-P5-HCGIV-HLA class I-HCGII, engendered the present-day MHC. That the currently nonessential HLA-F and MICE genes have acted as progenitors to today's immune-competent HLA-ABC and MICA/B genes provides experimental evidence for evolution by "birth and death," which has general relevance to our understanding of the evolutionary forces driving vertebrate multigene families.

Base Pairing↗
PubMed1999

Distinct role of antigen-specific T helper type 1 (Th1) and Th2 cells in tumor eradication in vivo.

The role of T helper type 1 (Th1) and Th2 cells in tumor immunity was investigated using Th cells induced from ovalbumin (OVA)-specific T cell receptor transgenic mice. Although Th1 cells exhibited stronger cytotoxicity than Th2 cells, both cell types completely eradicated tumors when transferred into mice bearing A20 tumor cells transfected with the OVA gene (A20-OVA). Th1 cells eradicated the tumor mass by inducing cellular immunity, whereas Th2 cells destroyed the tumor by inducing tumor necrosis. Both Th1 and Th2 cells required CD8(+) T cells to eliminate tumors, and neither of these cells were able to completely eliminate A20-OVA tumors from T and B cell-deficient RAG2(-/-) mice. Mice cured from tumors by Th1 and Th2 cell therapy rejected A20-OVA upon rechallenge, but CD8(+) cytotoxic T lymphocytes were induced only from spleen cells prepared from cured mice by Th1 cell therapy. Moreover, we demonstrated that Th1 and Th2 cells used distinct adhesion mechanisms during tumor eradication: the leukocyte function-associated antigen (LFA)-1-dependent cell-cell adhesion step was essential for Th1 cell therapy, but not for Th2 cell therapy. These findings demonstrated for the first time the distinct role of antigen-specific Th1 and Th2 cells during eradication of established tumors in vivo.

Animals↗
PubMed1999

CAST, a novel CD3epsilon-binding protein transducing activation signal for interleukin-2 production in T cells.

Antigen recognition through T cell receptor (TCR)-CD3 complex transduces signals into T cells, which regulate activation, function, and differentiation of T cells. The TCR-CD3 complex is composed of two signaling modules represented by CD3zeta and CD3epsilon. Signaling through CD3zeta has been extensively analyzed, but that via CD3epsilon, which is also crucial in immature thymocyte development, is still not clearly understood. We isolated cDNA encoding a novel CD3epsilon-binding protein CAST. CAST specifically interacts in vivo and in vitro with CD3epsilon but not with CD3zeta or FcRgamma via a unique membrane-proximal region of CD3epsilon. CAST is composed of 512 amino acids including a single tyrosine and undergoes tyrosine phosphorylation upon TCR stimulation. Overexpression of two dominant-negative types of CAST, a minimum CD3epsilon-binding domain and a tyrosine-mutant, strongly suppressed NFAT activation and interleukin-2 production. These results demonstrate that CAST serves as a component of preformed TCR complex and transduces activation signals upon TCR stimulation and represents a new signaling pathway via the CD3epsilon-containing TCR signaling module.

Amino Acid Sequence↗
PubMed1999

Identification of a novel promoter and exons of the c-ERBB-2 gene.

The c-ERBB-2 gene is frequently amplified in various cancers. During the course of studies on the structural characterization of the amplification units, we isolated four cDNA clones, A39, GRB7, C51 and CAB1 with corresponding genes localized on the c-ERBB-2 locus. A tentative gene, C51, was located at about 12 kb upstream of the c-ERBB-2 gene. By molecular cloning of a full-length cDNA clone of C51 and the reverse transcription PCR (RT-PCR) method, we identified a novel transcript of c-ERBB-2 containing new 5' sequences including the C51 sequence, demonstrating that the c-ERBB-2 gene has a novel promoter and new exons. The structural organization of the novel promoter and exons of c-ERBB-2 was revealed by complete sequence analysis of a total size of about 20 kb of genomic DNA clones containing the 5'-flanking region of the previously described c-ERBB-2 gene. Transient expression of the newly identified promoter-reporter gene constructs in breast cancer cell line MCF-7 showed that the elements responsible for promoter activity were contained in a 697 bp region upstream of the transcriptional start site. The new transcript may encode a protein different in the portion of the extracellular domain. Although the presence of the predicted protein product was not examined, this report is important in that it provides a new aspect of the c-ERBB-2 protooncogene products.

Adult↗