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Nobuyoshi Shimizu

Publications and source records attributed to Nobuyoshi Shimizu.

At least 37 records · Page 2Linked to original sources
PubMed2006

Organization and structure of hox gene loci in medaka genome and comparison with those of pufferfish and zebrafish genomes.

We isolated BAC clones that cover the entire hox gene loci in the medaka fish Oryzias latipes. The BAC clones were characterized by the Southern hybridization with many hox gene probes isolated in our previous study and by PCR using primers designed for selective amplification of respective hox genes. Then, the BAC clones have been subjected to shotgun sequencing. The results revealed the organization of the entire hox gene loci. Forty-six hox genes in total are encoded in seven clusters as follows: 10 hox genes in Aa cluster; 5 in Ab; 9 in Ba; 4 in Bb; 10 in Ca; 6 in Da; and 2 in Db. Together with the information on the hox gene loci registered in the Fugu genome database and in the Danio genome database, the physical maps of three fish genomes were constructed and compared one another. Not only numbers of hox genes but also the distances between the neighboring hox genes are highly similar between medaka and fugu. As for six clusters, Aa, Ab, Ba, Bb, Ca and Da that are commonly present in the three fishes, only few or no differences were found in each cluster. Thus, the hox gene sets should have been well conserved once they had been established in respective species.

Animals↗
PubMed2006

Mutational and epigenetic evidence for independent pathways for lung adenocarcinomas arising in smokers and never smokers.

Genetic and epigenetic alterations are considered to play important roles in lung cancer. Recent studies showed that EGFR and K-RAS mutations exhibited a mutually exclusive pattern in adenocarcinoma of the lung, suggesting the presence of two independent oncogenic pathways. However, it is unknown how epigenetic alterations were involved in lung carcinogenesis mediated by EGFR or K-RAS mutation. In this study, we examined the relationship between genetic and epigenetic alterations in 164 cases of lung adenocarcinoma. Somatic mutations were determined by direct sequence of EGFR exons 18 to 21 and K-RAS codons 12 and 13. Methylation status of p16(INK4a), RASSF1A, APC, RARbeta, and CDH13, frequently methylated in lung cancer, was determined by methylation-specific PCR and the degree of methylation was defined as the methylation index. Multivariate analysis adjusted for age, sex, and smoking dose showed that the probability of having EGFR mutation was significantly lower among those with p16(INK4a) and CDH13 methylation than in those without [p16(INK4a): odds ratio (OR), 0.07; 95% confidence interval (95% CI), 0.02-0.33; CDH13: OR, 0.34; 95% CI, 0.15-0.77] and the methylation index was significantly lower in EGFR mutant cases than in wild type (OR, 0.70; 95% CI, 0.52-0.95). By contrast, K-RAS mutation was significantly higher in p16(INK4a) methylated cases than in unmethylated cases (OR, 4.93; 95% CI, 1.54-15.7) and the methylation index was higher in K-RAS mutant cases than in wild type with marginal significance (OR, 1.46; 95% CI, 0.95-2.25). Our results indicate the differences in the evolvement of epigenetic alterations between the EGFR- and K-RAS-mediated tumorigenesis and suggest the specific interaction of genetic and epigenetic changes in tumorigenesis of lung cancer.

Adenocarcinoma↗
PubMed2006

DNA sequence and analysis of human chromosome 8.

The International Human Genome Sequencing Consortium (IHGSC) recently completed a sequence of the human genome. As part of this project, we have focused on chromosome 8. Although some chromosomes exhibit extreme characteristics in terms of length, gene content, repeat content and fraction segmentally duplicated, chromosome 8 is distinctly typical in character, being very close to the genome median in each of these aspects. This work describes a finished sequence and gene catalogue for the chromosome, which represents just over 5% of the euchromatic human genome. A unique feature of the chromosome is a vast region of approximately 15 megabases on distal 8p that appears to have a strikingly high mutation rate, which has accelerated in the hominids relative to other sequenced mammals. This fast-evolving region contains a number of genes related to innate immunity and the nervous system, including loci that appear to be under positive selection--these include the major defensin (DEF) gene cluster and MCPH1, a gene that may have contributed to the evolution of expanded brain size in the great apes. The data from chromosome 8 should allow a better understanding of both normal and disease biology and genome evolution.

Animals↗
PubMed2006

Detection of EGFR gene mutation in lung cancer by mutant-enriched polymerase chain reaction assay.

PURPOSE: Mutations in the epidermal growth factor receptor (EGFR) gene have been reported to be present in non-small cell lung cancer (NSCLC) and related to the responsiveness of tumors to EGFR tyrosine kinase inhibitors, suggesting its usefulness as a biomarker. Because clinical samples contain tumor and normal cells or genes, a highly sensitive assay for detecting mutation is critical for clinical applications. EXPERIMENTAL DESIGN: The mutant-enriched PCR is a rapid and sensitive assay with selective restriction enzyme digestion. We developed the mutant-enriched PCR assay targeting exons 19 and 21 of EGFR and applied the developed assay to detect mutations in 108 cases of surgically resected specimens of NSCLCs, 18 samples of computed tomography (CT)-guided needle lung biopsies, and 20 samples of pleural fluid. In addition, results were then compared with those from direct sequencing and a nonenriched PCR assay. RESULTS: The mutant-enriched PCR that was proved to enrich one mutant of 2 x 10(3) normal genes detected mutations in 37 cases of 108 resected tumors, seven samples of CT-guided lung biopsies, and seven samples of pleural fluid. Among mutant cases, four resected tumors, two CT-guided lung biopsies, and two pleural fluid were identified as additional mutant cases by the mutant-enriched PCR, which were considered normal based on nonenriched assays. CONCLUSIONS: Our results indicate that EGFR mutations are readily detectable by mutant-enriched PCR in various clinical samples. Thus, mutant-enriched PCR may provide a valuable method of potentially detecting a small fraction of mutant genes in heterogeneous specimens, indicating its possible use in clinical application for NSCLC.

Biopsy↗
PubMed2006

Anaplastic thyroid carcinoma associated with granulocyte colony-stimulating factor: report of a case.

A 75-year-old woman was hospitalized due to a right axillary mass. She had undergone a resection of thyroid carcinoma 13 years earlier, followed by two subsequent operations for recurrent thyroid disease. A physical examination revealed a right axillary mass associated with skin ulceration. Persistent bleeding was observed at the skin ulcer associated with the right axillary lymph node, despite conservative treatment for the lesion. Surgery was thus performed to control persistent bleeding from the axillary ulcer, and a histopathological examination resulted in a diagnosis of poorly differentiated thyroid carcinoma. The postoperative course was uneventful, but marked leukocytosis and extensive skin metastases were recognized 30 days postoperatively. A systemic examination revealed no other lesions associated with marked leukocytosis, but elevated levels of granulocyte colony-stimulating factor were noted in a blood examination. As a result, her general condition deteriorated rapidly and the patient died 2 weeks after the onset of leukocytosis.

Aged↗
PubMed2006

Transintestinal systemic oxygenation using perfluorocarbon.

PURPOSE: Perfluorocarbons have an excellent oxygen- and carbon dioxide-carrying capacity. This prompted us to investigate the feasibility of transintestinal systemic oxygenation using perfluorocarbon. METHODS: A rat hypoventilation model (room air, 20 breaths/min and a tidal volume of 10 ml/kg) was thus established, and FC-77 (Sumitomo-3M, Osaka, Japan) was used as a perfusate. Oxygenated FC-77 was perfused through the small intestine for 4 h. The rats were allocated into three groups as follows. Group 1 (n = 6): hypoventilation only; Group 2 (n = 6): saline was perfused instead of FC-77; Group 3 (n = 6): FC-77 was perfused. Arterial blood samples were drawn from the common iliac artery every 30 min until the end of perfusion. A standard blood gas analysis was performed. RESULTS: The PaO2 level in Group 3 was significantly higher than in Groups 1 or 2 (P = 0.006: at the end of perfusion, Group 1 = 58.6 +/- 14.5 mmHg, Group 2 = 65.2 +/- 29.4 mmHg, Group 3 = 84.0 +/- 35.5 mmHg). The PaCO2 level in Group 3 was significantly lower than that in Groups 1 or 2 (P = 0.014: at the end of perfusion, Group 1 = 56.8 +/- 8.5 mmHg, Group 2 = 52.6 +/- 5.7 mmHg, Group 3 = 44.4 +/- 11.1 mmHg). CONCLUSION: Our findings indicate that transintestinal systemic oxygenation is indeed possible and could therefore become a useful new modality for respiratory assist.

Animals↗
PubMed2006

Thymidine phosphorylase and dihydropyrimidine dehydrogenase expression levels in tumor and normal tissue specimens of T3 human colorectal carcinoma.

PURPOSE: Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are important enzymes related to the metabolism of 5-fluorouracil and its derivatives. We evaluated the association between the clinicopathological factors and these enzymes in patients with T3 colorectal carcinoma. METHODS: The TP and DPD expression levels in 15 patients with T3 colorectal carcinomas were measured in tumor and adjacent normal tissue specimens by enzyme-linked immunosorbent assay. Correlations between each enzyme and clinicopathological factors were also statistically evaluated. RESULTS: The TP levels in tumor and normal tissue specimens were 77.9 +/- 33.6 and 24.7 +/- 10.3, respectively (P < 0.001). The DPD levels in tumor and normal tissue specimens were 44.1 +/- 18.2 and 53.1 +/- 24.1, respectively (P = 0.46). The TP/DPD ratios in tumor and normal tissue specimens were 1.84 +/- 0.52 and 0.53 +/- 0.26, respectively (P < 0.001). The tumor/normal ratios of TP level in patients with and without liver metastasis were 1.79 +/- 0.91 and 4.67 +/- 2.51, respectively (P = 0.024). CONCLUSION: The measurement of the enzyme expression levels of TP and DPD is considered to be useful for better understanding the conditions of tumor progression. The mechanisms of regulation of these enzymes thus require further evaluation.

5'-Nucleotidase↗
PubMed2006

Treatment of fulminant hepatic failure in rats using a bioartificial liver device containing porcine hepatocytes producing interleukin-1 receptor antagonist.

Fulminant hepatic failure (FHF) is a serious clinical condition that is associated with high mortality. There is evidence that FHF is an inflammatory disease, which is supported clinically by elevated serum levels of cytokines. In an effort to develop hepatocytes with additional functions for use in our bioartificial liver (BAL) device, we focused on interleukin-1 (IL-1) blockade as a therapeutic modality. Primary porcine hepatocytes were isolated from the livers of miniature swine and then transfected with an adenoviral vector encoding human interleukin-1 receptor antagonist (AdIL-1Ra). The transfected hepatocytes secreted human IL-1Ra. These transfected hepatocytes were incorporated into a flat-plate BAL device to evaluate their efficacy in treating D-galactosamine (GalN)- induced FHF in a rat model. After extracorporeal perfusion with the BAL device containing the transfected hepatocytes, there were significant reductions in the plasma levels of hepatic enzymes (aspartate aminotransferase and alanine aminotransferase) and cytokines (IL-1 and IL-6), indicating a beneficial effect. Animal survival was significantly improved in the treated group compared to the control group. These experiments demonstrate that combining inflammatory cytokine blockade with a functional BAL device may be an effective therapeutic option in the treatment of FHF.

Adenoviridae↗
PubMed2006

Proteasome inhibitor bortezomib increases PTEN expression and enhances trastuzumab-induced growth inhibition in trastuzumab-resistant cells.

PTEN (phosphatase and tension homolog deleted on chromosome 10) has been shown to be inactivated in a wide range of cancers and the role of this gene product is associated with the suppression of the phosphatidylinositol-3-kinase (PI3K)/Akt pathway in many cancers. Recently, some reports demonstrated that the degree of PTEN expression could predict trastuzumab chemosensitivity in ErbB2-overexpressing breast cancer. Here, we demonstrate the possible involvement of a proteasome inhibitor (PS341) in PTEN expression and elucidate the influence of PI3K/Akt, one of the main cascades of the ErbB2 downstream pathway, and discuss the role of the proteasome inhibitors in trastuzumab resistance. ErbB2-overexpressing SKBR3 human breast cancer cells and trastuzumab-resistant SKBR3/R cells were analyzed in this study. We show that the expression of phosphorylated Akt was highly increased in trastuzumab-resistant cells, although the expression of PI3K, phosphorylated PI3K and non-phosphorylated Akt was unchanged in comparison with wild-type SKBR3 cells. However, following treatment with PS341, the level of phosphorylated Akt was decreased in a dose-dependent manner. Conversely, the level of PTEN was increased in the same fashion. PS341 showed sufficient cytotoxicity in resistant cells in combination with trastuzumab and the efficacy of trastuzumab was inclined to be better in resistant cells under PS341 treatment. Remarkable activity of Akt was observed in trastuzumab-resistant SKBR3 breast cancer cells and this phenomenon could be associated with the decreased expression of PTEN. The proteasome inhibitor PS341 could increase the level of PTEN and inhibit the downstream pathway of ErbB2, interfering with phosphorylation of Akt.

Antibodies, Monoclonal↗
PubMed2006

Autoimmune regulator (AIRE) gene is expressed in human activated CD4+ T-cells and regulated by mitogen-activated protein kinase pathway.

The autoimmune regulator (AIRE) gene is a gene responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. Here we show that AIRE is expressed in human peripheral CD4-positive T-cells, and most highly in antigen-and interleukin 2-stimulated T (IL-2T) cells. Mitogen-activated protein kinases (MAPKs), including MAPK kinase (MEK) 1/2 and p38 MAPK, were phosphorylated in IL-2T cells and the expression of the AIRE gene was inhibited by a specific p38 MAPK inhibitor (SB203580), thereby indicating that AIRE gene expression is controlled by the MAPK pathway in IL-2T cells. These data suggested the possible significance of the AIRE gene in the peripheral immune system.

CD4-Positive T-Lymphocytes↗
PubMed2006

In vitro evaluation of a newly developed implantable artificial lung.

A prototype of an implantable artificial lung without a pump (Prototype II) has been tested. A commercially available membrane oxygenator, MENOX AL6000alpha (Dainippon Ink and Chemicals, Inc., Tokyo, Japan), was used as a basic model. The packing density of the hollow fiber was decreased in order to achieve low resistance through the blood pathway. The configuration of its housing was also re-designed using computational fluid dynamics (CFD). The first prototype, known as Prototype I, was already tested in a 15 kg pig, which showed excellent gas exchange with normal hemodynamics. A second prototype, Prototype II, has a larger membrane surface area than Prototype I. The device was evaluated for resistance through the blood path and gas transfer rate in an in vitro setting by the single pass method using fresh bovine blood. The resistance through the blood path of Prototype II was 2.7+- 0.7 mmHg/(L/min) at Q = 5L/min. The oxygen (O2) transfer rate was 178 +- 5.3 ml/min at Q = 5 L/min, V/Q = 3, and the carbon dioxide (CO2) transfer rate was 149 +- 28 ml/min at Q = 5 L/min, V/Q = 2 (Q: blood flow rate, V: sweep oxygen flow rate through the artificial lung). For the purpose of implantation, this prototype showed sufficiently low resistance in the pulmonary circulation with reasonable gas exchange.

Artificial Organs↗
PubMed2006

Utility of vessel-sealing systems in thyroid surgery.

The LigaSure vessel-sealing system (VSS) represents a new approach to intraoperative ligation. This clinical study retrospectively examined the utility of the VSS in thyroid surgery. In this study, we analyzed 56 consecutive patients who underwent thyroid surgery. Characteristics such as operative duration, the volume of intraoperative hemorrhage, and postoperative course were analyzed and compared between thyroid surgery using the VSS or conventional handtie methods. The present results indicate no significant differences in operative duration, volume of intraoperative hemorrhage, postoperative course, or duration of postoperative drainage between surgeries using the VSS or conventional methods. However, the postoperative hospital stay was found to be significantly shorter (p<0.05) with the VSS. No serious postoperative complications were encountered, and no significant differences were observed in the frequency of postoperative complications between methods. The VSS may simplify procedures for thyroid surgery, and hemostasis is effective for both thyroid vessels and thyroid parenchyma. However, further evaluation is warranted to adequately determine the relative merits of the VSS compared to conventional handtie methods.

Adult↗
PubMed2006

Intraatrial extension of thyroid cancer: a case report.

A 61-year-old man, who was diagnosed with superior vena cava syndrome by papillary thyroid carcinoma, was referred to our hospital. A bulky thyroid tumor with tracheal invasion extended from the left neck to the right atrium without distant metastases. The risk of sudden death due to airway occlusion, tumor embolism or obstruction of the tricuspid valve led us to elect surgery. Extended resection of thyroid cancer was performed with cardiopulmonary bypass. Peritoneal dissemination was found via laparotomy. A histological diagnosis of anaplastic carcinoma arising from transformation of papillary carcinoma was made. After the operation, bilateral ureteral occlusion by peritoneal dissemination and multiple lung metastases were detected. The patient died with acute renal failure on postoperative day 12. Intraatrial extension of thyroid cancer is rare, and only 12 cases have been reported in the literature. We present a case of thyroid cancer with intraatrial extension.

Carcinoma↗
PubMed2006

Suppression effects of human recombinant tissue inhibitor of metalloproteinases-1(TIMP-1) on tumor proliferation using in vivo treatment model of well-differentiated colon cancer cell line, HT29.

To investigate the suppressive effect of human recombinant TIMP-1 (rh-TIMP-1) on tumor proliferation using an in vivo xenograft system, HT29 was suspended in 0.1 ml phosphate buffered saline (PBS) and then subcutaneously injected in the back of female mice (BALB/C nu/nu). The mice were divided into 2 groups an and the tumor diameter was measured after rh-TIMP-1 (2 mg/kg) (rh-TIMP-1 group) or PBS (control group) was administered injections according to the following schedules. Schedule 1 : Beginning 2 weeks after the subcutaneous injection of HT29, an intraperitoneal injection of rh-TIMP-1 or PBS were performed twice a day (every 12 h) for 14 consecutive days. Schedule 2 : Beginning 1 week after the subcutaneous injection of HT29, an intraperitoneal injection was performed twice a day for 14 consecutive days. Schedule 3 : Intraperitoneal injections were started simultaneously with the subcutaneous injection of HT29, and then performed twice a day for 21 consecutive days. The mice were sacrificed and the tumors extirpated for immunohistochemical investigation. In addition, gelatin zymography and a cell proliferation assay were performed. With Schedule 1, the changes in the tumor diameter in the rh-TIMP-1 group followed the same course as those in the control group, and no suppressive effect on tumor proliferation was observed. However, with Schedule 3, a remarkable suppressive effect was observed throughout the treatment period. In immunostaining, more cases negative for MMP-9 were observed in the rh-TIMP-1 group than in the control group. Cases negative for CD34 were significantly more observed in the rh-TIMP-1 group than in the control group with Schedule 3. All of the results were obtained through the suppressive effect of rh-TIMP-1 on angiogenesis.

Animals↗
PubMed2006

An experimental study on pumpless extracorporeal membrane oxygenation (ECMO) support in a canine model.

This study was carried out to determine whether an extracorporeal membrane oxygenation (ECMO) support could be sufficiently conducted by the right ventricle alone from the viewpoint of the hemodynamics and blood gas state. Six infant dogs underwent a bypass between the left pulmonary artery and left atrium with an in-line oxygenator after a left pneumonectomy. Partial ECMO support was conducted simply by opening the circuit, and total ECMO support was conducted by ligating the right pulmonary artery. After the establishment of partial ECMO, approximately one-third of the right ventricular output was passively shunted through the bypass circuit, and the cardiac index and central venous pressure did not change. The mean pulmonary arterial pressures increased significantly. After a complete ligation of the right pulmonary artery, all 6 dogs survived for 12 h, but the cardiac output and blood pressure decreased significantly. The blood gas state was sufficiently maintained throughout the experiment. The results suggest the possibility of using the pumpless ECMO support. However, the flow resistance of the membrane oxygenator proved to still be too high for use in a total pumpless ECMO. Further studies on long-term ECMO and the development of a membrane oxygenator with a considerably low flow-resistance are needed.

Animals↗
PubMed2006

Gefitinib, an epidermal growth factor receptor blockade agent, shows additional or synergistic effects on the radiosensitivity of esophageal cancer cells in vitro.

Human esophageal cancers have been shown to express high levels of epidermal growth factor receptor (EGFR) and a relationship between high EGFR expression and local advance, the number of lymph node metastases, life expectancy, and sensitivity to chemo-radiotherapy has been demonstrated. We examined the use of gefitinib, an orally active EGFR-selective tyrosine kinase inhibitor, as a new strategy for treatment of esophageal carcinoma. The effects of gefitinib were evaluated in monotherapy and in combination with radiotherapy in human esophageal carcinoma cell lines. Gefitinib produced a dose-dependent inhibition of cellular proliferation in all of the 8 esophageal carcinoma cell lines examined, with IC50 values ranging from 5.7 microM to 36.9 microM. In combination, gefitinib and radiotherapy showed a synergistic effect in 2 human esophageal carcinoma cell lines and an additive effect in 5 cell lines. Western blotting demonstrated that gefitinib blocked activation of the EGFR-extracellular signal-regulated kinase (Erk) pathway and the EGFR-phosphoinositide-3 kinase (PI3K)-Akt pathway after irradiation. These results suggest that further evaluation of EGFR blockade as a treatment for esophageal cancer should be performed, and that radiotherapy combined with EGFR blockade may enhance the response of esophageal carcinoma to therapy.

Animals↗
PubMed2006

Molecular cloning of the m-Golsyn gene and its expression in the mouse brain.

The mouse ortholog of the human GOLSYN gene, termed the m-Golsyn gene, was isolated and mapped to the region on mouse chromosome 15B3.2 syntenic with human chromosome 8q23. Three mRNA species (type la, 1b, and type 2) were produced by use of alternative transcription initiation points and alternative splicing events. The type 1 mRNAs were expressed only in the brain, whereas the type 2 was detected in various tissues. m-Golsyn protein was expressed in various tissues including the brain. Immunohistochemical study of m-Golsyn protein showed its prominent expression in the neuronal cells in various regions of the brain and strong expression in the choroid plexus ependymal cells lining the ventricles. m-Golsyn protein was found to be homologous to syntaphilin, a regulator of synaptic vesicle exocytosis. These results indicate that the m-Golsyn protein may play an important role in intracellular protein transport in neuronal cells of the brain.

Alternative Splicing↗