Search PubMed⌕ Search

Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 19 recordsLinked to original sources

A phase II trial of gefitinib as first-line therapy for advanced non-small cell lung cancer with epidermal growth factor receptor mutations.

Retrospective analysis has shown that activating mutations in exons 18-21 of the epidermal growth factor receptor (EGFR) gene are a predictor of response to gefitinib. We conducted a phase II trial to evaluate the efficacy and safety of gefitinib as first-line therapy for advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Patients with stage IIIB or IV chemotherapy-naïve NSCLC with EGFR mutation were treated with 250 mg gefitinib daily. For mutational analysis, DNA was extracted from paraffin-embedded tissues and EGFR mutations were analysed by direct sequence of PCR products. Twenty (24%) of the 82 patients analysed had EGFR mutations (deletions in or near E746-A750, n=16; L858R, n=4). Sixteen patients were enrolled and treated with gefitinib. Twelve patients had objective response and response rate was 75% (95% CI, 48-93%). After a median follow-up of 12.7 months (range, 3.1-16.8 months), 10 patients demonstrated disease progression, with median progression-free survival of 8.9 months (95% CI, 6.7-11.1 months). The median overall survival time has not yet been reached. Most of the toxicities were mild. This study showed that gefitinib is very active and well tolerated as first-line therapy for advanced NSCLC with EGFR mutations.

Administration, Oral↗

Measurement of atmospheric neutrino flux consistent with tau neutrino appearance.

A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma.

Journal Article↗

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma.

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

Animals↗

Congenital osteofibrous dysplasia associated with pseudoarthrosis of the tibia and fibula.

The association between congenital pseudoarthrosis and osteofibrous dysplasia of the tibia and fibula is a rare entity that has been recently recognized. We report a male newborn who was found to have swelling and deformity of the left lower leg. Radiographs and magnetic resonance imaging showed an extensive destructive lesion of the tibial shaft, with dysplastic congenital pseudoarthrosis of the lower fibula. Histopathological examination confirmed the diagnosis of congenital pseudoarthrosis of the tibia and fibula with underlying osteofibrous dysplasia involving both bones. Immunohistochemical stains showed cytokeratin positivity.

Fibrous Dysplasia of Bone↗

Genetic linkage analysis of pulmonary fibrotic response to silica in mice.

Inter-individual variations in the development of silicosis, even within the same environments, have been reported, which suggest the contribution of genetic factors in silicosis aetiology. The aim of the present study was to determine whether there is any significant genetic influence on the development of silicosis. Furthermore, which genetic loci are responsible for the pulmonary response to silica exposure? Eight strains of inbred mice were used to examine the genetic influence on the lung fibrotic response to silica exposure. After intercross-breeding between the most susceptible and most resistant strains, a genome-wide linkage analysis of quantitative trait loci (QTL) was performed. Hydroxyproline was applied as an index, and genotypes of 167 marker genes were analysed by fragment analysis using a capillary-type sequencer. There was significant inter-strain difference in the mean concentration of hydroxyproline contents among the eight strains of mice. Breeding studies were conducted between the most susceptible, C57BL/6J, and the most resistant strain, CBA/J. A genome-wide linkage analysis of silica-exposed intercrossed cohorts identified significant QTL on chromosome 4 and suggestive QTL on chromosomes 3 and 18. The present study demonstrates that genetic factors may play a significant role in fibrotic-lung responses to silica; one significant and two suggestive quantitative trait loci were identified.

Air Pollutants, Occupational↗

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment.

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.

Journal Article↗

Prolactin regulatory element binding protein as a potential transcriptional factor for the insulin gene in response to glucose stimulation.

AIMS/HYPOTHESIS: Prolactin regulatory element binding (PREB) protein has been identified as a factor that regulates prolactin promoter activity in rat anterior pituitary. PREB is located not only in the anterior pituitary but also in pancreas; however its role in the pancreas is not known. We therefore examined the role of PREB in insulin gene expression. MATERIALS AND METHODS: To analyse the effects of PREB on insulin gene transcription, we employed the luciferase reporter gene assay and electrophoretic mobility shift assay (EMSA). In cells expressing or knocked down for PREB, insulin expression and secretion were determined. RESULTS: PREB was located mainly in nuclei of rat pancreatic beta cells and its cell line, INS-1. A nuclear extract of INS-1 cells contained material that was recognised by PREB antiserum. This nuclear extract also showed insulin promoter binding activity that was super-shifted by PREB antiserum in EMSA studies. In the INS-1 cells, co-expression of PREB and the insulin promoter induced activity of the latter. The addition of glucose to the cells increased PREB expression. Deletional analysis of the insulin promoter showed that A3, a glucose-responsive cis-element in the insulin promoter, mediated the transcriptional effect of PREB. In addition, synthesised PREB bound the A3 element by EMSA, while a mutant of this motif in the insulin promoter abrogated the effect of PREB. Cells expressing or knocked down for PREB exhibited increased or decreased insulin expression, respectively. CONCLUSIONS/INTERPRETATION: These results demonstrate that PREB may contribute to the regulation of insulin gene transcription and insulin secretion in response to glucose stimulation.

Animals↗

Estimation of the species-specific mutation rates at the DRB1 locus in humans and chimpanzee.

To estimate the species-specific mutation rates at the DRB1 locus in humans and chimpanzee, we analyzed the nucleotide sequence of a 37.6-kb chimpanzee chromosomal segment containing the entire Patr-DRB1*0701 allele and the flanking nongenic region and we compared it with two corresponding human sequences containing the HLA-DRB1*070101 allele using the sequence of HLA-DRB1*04011 as an outgroup. Because the allelic pair of HLA-DRB1*070101 and Patr-DRB1*0701 shows the lowest number of substitutions between the two species, it appears that these sequences diverged close to the time of the humans-chimpanzee divergence (6 million years ago). Alignment of the nucleotide sequences for HLA-DRB1*070101 and Patr-DRB1*0701 alleles showed that they share a high degree of similarity, suggesting that the studied chromosomal segments with these sequences have not been subjected to recombination since the humans-chimpanzee divergence. Comparison of the flanking 10.6 kb of nongenic sequences revealed an average of 41.5 and 83 single nucleotide substitutions in humans and chimpanzee, respectively. Thus, the species-specific nucleotide substitution rates in the flanking nongenic region were estimated to be 6.53 x 10(-10) and 1.31 x 10(-9) per site per year in humans and chimpanzee, respectively. Unexpectedly, the estimated rate in humans was twofold lower than in chimpanzee (P < 10(-3), Tajima's relative rate test) and lower than the average substitution rate in the human genome. Because the nucleotide substitution rate in nongenic regions free from selection is expected to be equal to the mutation rate, the estimated substitution rate should correspond to the species-specific mutation rate at the DRB1 locus. Our results strongly suggest that the mutation rate at DRB1 locus differs among species.

Alleles↗

Peroxisome proliferator-activated receptor gamma in human breast carcinoma: a modulator of estrogenic actions.

It has been reported that agonists of peroxisome proliferator-activated receptor gamma (PPARgamma) inhibit proliferation of breast carcinoma cells, but the biological significance of PPARgamma remains undetermined in human breast carcinomas. Therefore, we immunolocalized PPARgamma in 238 human breast carcinoma tissues. PPARgamma immunoreactivity was detected in 42% of carcinomas, and was significantly associated with the status of estrogen receptor (ER) alpha, ERbeta, progesterone receptor, retinoic X receptors, p21 or p27, and negatively correlated with histological grade or cyclooxygenase-2 status. PPARgamma immunoreactivity was significantly associated with an improved clinical outcome of breast carcinoma patients by univariate analysis, and multivariate analysis demonstrated that PPARgamma immunoreactivity was an independent prognostic factor for overall survival in ERalpha-positive patients. We then examined possible mechanisms of modulation by PPARgamma on estrogenic actions in MCF-7 breast carcinoma cells. A PPARgamma activator, 15-deoxy-Delta(12,14)- prostaglandin J(2) (15d-PGJ(2)), significantly inhibited estrogen-responsive element-dependent transactivation by estradiol in MCF-7 cells, which was blocked by addition of a PPARgamma antagonist GW9662. Subsequent study, employing a custom-made microarray focused on estrogen-responsive genes, revealed that mRNA expression was significantly regulated by estradiol in 49 genes, but this significance vanished on addition of 15d-PGJ(2) in 16 out of 49 (33%) genes. These findings were confirmed by real-time PCR in 11 genes. 15d-PGJ(2) significantly inhibited estrogen-mediated proliferation of MCF-7 cells, and caused accumulation of p21 and p27 protein. These results suggest that PPARgamma is mainly expressed in well-differentiated and ER-positive breast carcinomas, and modulates estrogenic actions.

Adult↗

HRCT shows variations in appearance in disseminated tuberculosis in adults.

OBJECTIVE: To examine patterns of high resolution computed tomography (HRCT) of lungs of adults with disseminated tuberculosis (TB). DESIGN: Disseminated TB was defined as radiological involvement of all lung lobes. RESULTS: The case series illustrated wide variation in HRCT of disseminated TB. Patterns identified on HRCT included (1) miliary TB (haematogenous dissemination), (2) miliary TB with exudative reaction, (3) bronchogenic spread, (4) miliary TB mixed with bronchogenic spread, and (5) bronchogenic spread with multiple cavity formation. CONCLUSION: The HRCT patterns described allow classification of disseminated TB according to the mechanism of spread (haematogenous and/or bronchogenic) and the degree of local lung involvement (reaction or cavitation).

Aged↗

Search for coherent charged pion production in neutrino-carbon interactions.

We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.

Journal Article↗

Orally active antioxidative copper(II) aspirinate: synthesis, structure characterization, superoxide scavenging activity, and in vitro and in vivo antioxidative evaluations.

Ever since it was proposed that reactive oxygen species (ROS) are involved in the pathogeneses of various diseases, superoxide dismutase (SOD)-mimetic complexes have been intensively studied. We prepared copper(II) aspirinate [Cu2(asp)4] from Cu(II) and aspirin, which has been in use for many years as an antipyretic, an analgesic, and an anti-inflammatory agent. However, Cu2(asp)4 has been found to have additional activities, including anti-inflammatory, antiulcer, anti-ischemic/reperfusion agent, anticancer, antimutagenic, and antimicrobial activities. The activity of copper salicylate [Cu(sal)2] was also compared with that of Cu2(asp)4. The structure of the Cu2(asp)4 was determined using X-ray structure analysis. Its SOD-mimetic activity was determined using cytochrome c, electron spin resonance (ESR) spectroscopy, and ESR spin trap methods. The activity of Cu2(asp)4 was slightly greater than CuSO4 and copper acetate [Cu(ace)2] and slightly less than that of Cu(sal)2. The in vitro antioxidant activity, evaluated in human epithelial or transformed neoplastic keratinocyte cells, HaCaT, and normal dermal fibroblasts in terms of cell survival following ultraviolet B (UVB) irradiation, was significantly increased in the presence of Cu2(asp)4, Cu(sal)2, and CuSO4. Further, ROS generation following UVA irradiation in the skin of hairless mice following oral treatment with Cu2(asp)4 for three consecutive days was significantly suppressed compared to the vehicle- or Cu(ace)2-treated mice. On the basis of these results, Cu2(asp)4 was observed to be a potent antioxidative compound possessing antioxidative activity in biological systems. In conclusion, Cu2(asp)4 is a potent antioxidative agent that may be useful for future treatment of diseases resulting from ROS.

Administration, Oral↗

Aberrant DNA methylation associated with silencing BNIP3 gene expression in haematopoietic tumours.

Hypoxia is a key factor contributing to the progression of human neoplasias and to the development of resistance to chemotherapy. BNIP3 is a proapoptotic member of the Bcl-2 protein family involved in hypoxia-induced cell death. We evaluated the expression and methylation status of BNIP3 gene to better understand the role of epigenetic alteration of its expression in haematopoietic tumours. Methylation of the region around the BNIP3 transcription start site was detected in four acute lymphocytic leukaemia, one multiple myeloma and one Burkitt lymphoma cell lines, and was closely associated with silencing the gene. That expression of BNIP3 was restored by treatment with 5-aza2'-deoxycytidine (5-aza-dC), a methyltransferase inhibitor, which confirmed the gene to be epigenetically inactivated by methylation. Notably, re-expression of BNIP3 using 5-aza2-dC also restored hypoxia-mediated cell death in methylated cell lines. Acetylation of histone H3 in the 5' region of the gene, which was assessed using chromatin immunoprecipitation assays, correlated directly with gene expression and inversely with DNA methylation. Among primary tumours, methylation of BNIP3 was detected in five of 34 (15%) acute lymphocytic leukaemias, six of 35 (17%) acute myelogenous leukaemias and three of 14 (21%) multiple myelomas. These results suggest that aberrant DNA methylation of the 5' CpG island and histone deacetylation play key roles in silencing BNIP3 expression in haematopoietic tumours.

Base Sequence↗

Evidence for muon neutrino oscillation in an accelerator-based experiment.

We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).

Journal Article↗

Antimyeloma effects of a novel synthetic retinoid Am80 (Tamibarotene) through inhibition of angiogenesis.

In multiple myeloma (MM), the interaction between myeloma cells and bone marrow microenvironment has an important role in the pathogenesis of MM. We first examined the inducing effect of myeloma cells on migration of human umbilical vein vascular endothelial cells (HUVECs). Five myeloma cell lines produced varying amounts of VEGF, and migration of HUVECs was induced by coculture with myeloma cells. We next examined the inhibitory effect of a novel synthetic retinoid Am80 (Tamibarotene) on both myeloma cells and HUVECs. Am80 is specific for the retinoic-acid receptor-alpha/beta, and has therapeutic effects in all-trans retinoic acid resistant acute promyelocytic leukemia. Am80 slightly inhibited the growth of both myeloma cells and HUVECs, and remarkably inhibited the growth of HUVECs stimulated by VEGF. Am80 showed little growth inhibition of bone marrow stromal cells (BMSCs), but it markedly inhibited migration of HUVECs by cocultured myeloma cells. Am80 inhibited VEGF-induced phosphorylation of VEGF receptor. In addition, VEGF-induced formation of tube-like structures in vitro and neovascularization in mouse corneas were significantly inhibited by Am80. These findings clearly demonstrate that Am80 is a potential inhibitor of angiogenesis caused by the interaction between vascular endothelial cells and myeloma cells, and might be a useful therapeutic agent against MM.

Animals↗

Multiple myeloma oncogene 1 (MUM1)/interferon regulatory factor 4 (IRF4) upregulates monokine induced by interferon-gamma (MIG) gene expression in B-cell malignancy.

MUM1 (multiple myeloma oncogene 1)/IRF4 (interferon regulatory factor 4) is a transcription factor that is activated as a result of t(6;14)(p25;q32) in multiple myeloma. MUM1 expression is seen in various B-cell lymphomas and predicts an unfavorable outcome in some lymphoma subtypes. To elucidate its role in B-cell malignancies, we prepared MUM1-expressing Ba/F3 cells, which proliferated until higher cellular density than the parental cells, and performed cDNA microarray analysis to identify genes whose expression is regulated by MUM1. We found that the expression of four genes including FK506-binding protein 3 (FKBP3), the monokine induced by interferon-gamma(MIG), Fas apoptotic inhibitory molecule (Faim) and Zinc-finger protein 94 was altered in the MUM1-expressing cells. We then focused on MIG since its expression was immediately upregulated by MUM1. In reporter assays, MUM1 activated the MIG promoter in cooperation with PU.1, and the interaction between MUM1 and the MIG promoter sequence was confirmed. The expression of MIG was correlated with that of MUM1 in B-CLL cell lines, and treatment with neutralizing antibodies against MIG and its receptor, CXCR3, slightly inhibited the proliferation of two MUM1-expressing lines. These results suggest that MUM1 plays roles in the progression of B-cell lymphoma/leukemia by regulating the expression of various genes including MIG. Leukemia (2005) 19, 1471-1478. doi:10.1038/sj.leu.2403833; published online 16 June 2005.

Animals↗