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T Tsunoda

Publications and source records attributed to T Tsunoda.

At least 37 records · Page 2Linked to original sources
PubMed2001

Alterations of gene expression during colorectal carcinogenesis revealed by cDNA microarrays after laser-capture microdissection of tumor tissues and normal epithelia.

To identify a set of genes involved in the development of colorectal carcinogenesis, we compared expression profiles of colorectal cancer cells from eight tumors with corresponding noncancerous colonic epithelia using a DNA microarray consisting of 9216 human genes. These cell populations had been rendered homogeneous by laser-capture microdissection. Expression change in more than half of the tumors was observed for 235 genes, i.e., 44 up-regulated and 191 down-regulated genes. The differentially expressed genes include those associated with signal transduction, metabolizing enzymes, production of reactive oxygen species, cell cycle, transcription, mitosis, and apoptosis. Subsequent examination of 10 genes (five up-regulated and five down-regulated) by semiquantitative reverse transcription-PCR using the eight tumors together with an additional 12 samples substantiated the reliability of our analysis. The extensive list of genes identified in these experiments provides a large body of potentially valuable information of colorectal carcinogenesis and represents a source of novel targets for cancer therapy.

Colorectal Neoplasms↗
PubMed2001

Growth and gene expression profile analyses of endometrial cancer cells expressing exogenous PTEN.

The PTEN tumor suppressor gene encodes a multifunctional phosphatase that plays an important role in inhibiting the phosphatidylinositol-3-kinase pathway and downstream functions that include activation of Akt/protein kinase B, cell survival, and cell proliferation. Enforced expression of PTEN in various cancer cell lines decreases cell proliferation through arrest of the cell cycle, accompanied in some cases by induction of apoptosis. We used cDNA microarrays containing 4009 cDNAs to examine changes in gene-expression profiles when exogenous PTEN was induced in PTEN-defective cells. The microarrays and subsequent semi-quantitative reverse transcription-PCR analysis revealed transcriptional stimulation of 99 genes and repression of 72 genes. Some of the differentially expressed genes already had been implicated in cell proliferation, differentiation, apoptosis, or cell cycle control, e.g., overexpression of PTEN-induced transactivation of cyclin-dependent inhibitor 1B (p27Kip1) and 2B (p15INK4B), members of the TNF receptor family, tumor necrosis factor-associated genes, and members of the Notch-signaling and Mad families. To our knowledge this is the first report of transactivation of those genes by PTEN. The genes differentially expressed in our experiments also included many whose correlation with cancer development had not been recognized before. Our data should contribute to a greater understanding of the broad spectrum of ways in which PTEN affects intracellular signaling pathways. Analysis of expression profiles with microarrays appears to be a powerful approach for identifying anticancer genes and/or disease-specific targets for cancer therapy.

Adenoviridae↗
PubMed2001

Generation of cytotoxic T cell responses to an HLA-A24 restricted epitope peptide derived from wild-type p53.

Mutations in the p53 gene are the most common genetic alterations found in human tumours, and these mutations result in high levels of p53 protein in the tumour cells. Since the expression levels of wild-type p53 in nonmalignant tissue are usually much lower in contrast, the p53 protein is an attractive target for cancer immunotherapy. We tested p53 encoded HLA-A24 binding peptides for their capacity to elicit anti-tumour cytotoxic T lymphocytes (CTL) in vitro. These peptides were in murine p53-derived cytotoxic peptides, which were being presented to CTL by H-2K(d)and H-2K(b)molecules, because the HLA-A24 peptide binding motifs were similar to the H-2K(d)and H-2K(b). For CTL induction, we used CD8(+)T lymphocytes from the peripheral blood mononuclear cells (PBMC) of healthy donors and the peptides from pulsed dendritic cells as antigen-presenting cells. We identified the peptide, p53-161 (AIYKQSQHM), which was capable of eliciting CTL lines that lysed tumour cells expressing HLA-A24 and p53. The effectors lysed C1RA24 cells (p53(+), HLA-A*2402 transfectant), but not their parental cell lines C1R (p53(+), HLA-A,B null cell). These results strongly indicate that the CTL exerts cytotoxic activity in HLA-A24's restricted manner. The identification of this novel p53 epitope for CTL offers the possibility to design and develop specific immunotherapeutic approaches for treating tumours with p53 mutation in HLA-A24-positive patients.

Animals↗
PubMed2001

Genome-wide analysis of gene expression in human hepatocellular carcinomas using cDNA microarray: identification of genes involved in viral carcinogenesis and tumor progression.

To disclose detailed genetic mechanisms in hepatocellular carcinoma (HCC) with a view toward development of novel therapeutic targets, we analyzed expression profiles of 20 primary HCCs and their corresponding noncancerous tissues by means of cDNA microarrays consisting of 23,040 genes. Up-regulation of mitosis-promoting genes was observed in the majority of the tumors examined. Some genes showed expression patterns in hepatitis B virus-positive HCCs that were different from those in hepatitis C virus-positive HCCs; most of them encoded enzymes that metabolize carcinogens and/or anticancer agents. Furthermore, we identified a number of genes associated with malignant histological type or invasive phenotype. Accumulation of such data will make it possible to define the nature of individual tumors, to provide clues for identifying new therapeutic targets, and ultimately to optimize treatment of each patient.

Carcinoma, Hepatocellular↗
PubMed2001

Association between a single-nucleotide polymorphism in the promoter of the human interleukin-3 gene and rheumatoid arthritis in Japanese patients, and maximum-likelihood estimation of combinatorial effect that two genetic loci have on susceptibility to the disease.

Genetic variants of interleukin-3 (IL-3), a well-studied cytokine, may have a role in the pathophysiology of rheumatoid arthritis (RA); but reports on this association sometimes conflict. A case-control study was designed to investigate association between RA and a single-nucleotide polymorphism (SNP) in the IL-3 promoter region. Comparison of cases of RA versus control individuals yielded a chi(2) value of 14.28 (P=.0002), with a genotype odds ratio of 2.24 (95% confidence interval [95%CI] 1.44-3.49). When female cases with earlier onset were compared with female control individuals, the SNP revealed an even more significant correlation, with chi2=21.75 (P=.000004) and a genotype odds ratio of 7.27 (95%CI 2.80-18.89). The stronger association that we observed in this clinically distinct subgroup (females with early onset), within a region where linkage disequilibrium was not significantly extended, suggested that the genuine RA locus should locate either within or close to the IL-3 gene. Combined genotype data on SNPs on eight other candidate genes were combined with our IL-3 results, to estimate relationships between pairs of loci and RA, by maximum-likelihood analysis. The utility of combining the genotype data in this way to identify possible contributions of various genes to this disease is discussed.

Age of Onset↗
PubMed2001

Effect of adsorption of bovine serum albumin on liposomal membrane characteristics.

The effect of adsorption of bovine serum albumin (BSA) on the membrane characteristics of liposomes at pH 7.4 was examined in terms of zeta potential, micropolarity, microfluidity and permeability of liposomal bilayer membranes, where negatively charged L-alpha-dipalmitoylphosphatidylglycerol (DPPG)/L-alpha-dipalmitoylphosphatidylcholine (DPPC), negatively charged dicetylphosphate (DCP)/DPPC and positively charged stearylamine (SA)/DPPC mixed liposomes were used. BSA with negative charges adsorbed on negatively charged DPPG/DPPC mixed liposomes but did not adsorb on negatively charged DCP/DPPC and positively charged SA/DPPC mixed liposomes. Furthermore, the adsorption amount of BSA on the mixed DPPG/DPPC liposomes increased with increasing the mole fraction of DPPG in spite of a possible electrostatic repulsion between BSA and DPPG. Thus, the adsorption of BSA on liposomes was likely to be related to the hydrophobic interaction between BSA and liposomes. The microfluidity of liposomal bilayer membranes near the bilayer center decreased by the adsorption of BSA, while the permeability of liposomal bilayer membranes increased by the adsorption of BSA on liposomes. These results are considered to be due to that the adsorption of BSA brings about a phase separation in liposomes and that a temporary gap is consequently formed in the liposomal bilayer membranes, thereby the permeability of liposomal bilayer membranes increases by the adsorption of BSA.

Journal Article↗
PubMed2001

Effects of lysozyme and bovine serum albumin on membrane characteristics of dipalmitoylphosphatidylglycerol liposomes.

The effects of adsorption of two kinds of proteins on the membrane characteristics of liposomes were examined at pH 7.4 in terms of adsorption amounts of proteins on liposomes, penetrations of proteins into liposomal bilayer membranes, phase transition temperature, microviscosity and permeability of liposomal bilayer membranes, using positively charged lysozyme (LSZ) and negatively charged bovine serum albumin (BSA) as proteins and negatively charged L-alpha-dipalmitoylphosphatidylglycerol (DPPG) liposomes. The saturated adsorption amount of LSZ was 720 g per mol of liposomal DPPG, while that of BSA was 44 g per mol of liposomal DPPG. The penetration of LSZ into DPPG lipid membranes was greater than that of BSA. The microviscosity in the hydrophobic region of liposomal bilayer membranes increased due to adsorption (penetration) of LSZ or BSA, while the permeability of liposomal bilayer membranes increased. The gel-liquid crystalline phase transition temperature of liposomal bilayer membranes was not affected by adsorption of LSZ or BSA, while the DSC peak area (heat of phase transition) decreased with increasing adsorption amount of LSZ or BSA. It is suggested that boundary DPPG makes no contribution to the phase transition and that boundary DPPG and bulk DPPG are in the phase-separated state, thereby increasing the permeability of liposomal bilayer membranes through adsorption of LSZ or BSA. A possible schematic model for the adsorption of LSZ or BSA on DPPG liposomes was proposed.

Journal Article↗
PubMed2001

Mapping the HLA-A24-restricted T-cell epitope peptide from a tumour-associated antigen HER2 / neu: possible immunotherapy for colorectal carcinomas.

HER2 / neu is a potential antigen candidate for immunotherapy because of its correlation to a poor prognosis and high expressions in many kinds of epithelial tumours. Especially in the colorectal carcinomas, the higher expression of HER2 / neu is recognized in metastatic regions as well as in primary sites. Several CTL epitopes restricted by HLA-A2.1 and -A3 were identified so far, however epitopes restricted by HLA-A24, that is one of the most common allele in Japanese and Caucasians, have not been identified. In this paper, we showed identification of a CTL epitope peptide of HER2 / neu restricted by HLA-A24. HLA-A24 binding peptides selected by an analysis based on HLA-A24 binding motifs were determined for their binding affinities to HLA-A24 molecules. The peptide with a sequence of RWGLLLALL (position 8-16) named HE1 showed the highest affinity. We induced CTLs from CD8(+)cells of HLA-A24 healthy donors by stimulation with HE1-pulsed autologous dendritic cells. The CTLs showed cytotoxic activity against not only the peptide-pulsed target cells but also HLA-A24 colorectal tumour cell lines that endogenously overexpressed HER2 / neu. The antigen-specificity was confirmed by cold target inhibition assay using HE1-pulsed target cells. In summary, HER2 / neu peptide, RWGLLLALL, may contribute to the induction of antitumour immunity with the peptide-based immunotherapy for the colorectal carcinomas.

Colorectal Neoplasms↗
PubMed2001

Primary angioplasty for isolated right ventricular infarction.

We describe a case of isolated right ventricular infarction that has rarely been diagnosed antemortem. Electrocardiogram showed ST segment elevation in left precordial chest, right precordial chest, and inferior leads, which mimicked those of anterior and inferior left ventricular infarction. Coronary angiography revealed that culprit lesion was totally occluded right coronary artery. Infarcted artery was nondominant right coronary artery with branches supplying only right ventricular wall. Restoration of coronary blood flow was obtained by primary stenting and resulted in prompt ST segment normalization in all leads. Despite extensive right ventricular wall motion abnormality, subsequent right ventricular dysfunction was not observed.

Aged↗
PubMed2001

Primary adenocarcinoma of the duodenum demonstrated by ultrasonography.

A 57 year-old man presented with abdominal discomfort and melena. Abdominal ultrasonography clearly revealed a duodenal tumor as a hypoechoic mass in the transverse segment of the duodenum. The lesion was a 4 x 4-cm oval mass with partial concavity, an irregular surface, high-level central echoes, and a hypoechoic periphery. After confirmation of the diagnosis of duodenal carcinoma, a pylorus-preserving pancreatoduodenectomy was performed curatively. Pathological examination revealed moderately differentiated tubular adenocarcinoma partially invading the pancreatic parenchyma. Ultrasonography can be used to detect lesions of the transverse segment of the duodenum as the first imaging procedure.

Adenocarcinoma↗
PubMed2001

Intralobar pulmonary sequestration supplied by multiple anomalous arteries: report of a case.

Pulmonary sequestration is abnormal pulmonary tissue that has separated from the normal pulmonary parenchyma, is not connected to the tracheobronchial tree, and is supplied by a systemic artery. We describe herein a case of intralobar pulmonary sequestration found in a 66-year-old man who was admitted to our hospital with hemoptysis, coughing, and fever. Angiography showed that the branches of the 11th left intercostal artery and a bronchial artery had formed a hypervascular area in the lower part of the left lung. Bronchial artery embolization and subsequent embolization of the left 11th intercostal artery were performed in an attempt to control the recurrent hemoptysis. These treatments were unsuccessful, and he was transferred to our department of surgery after coughing up about 400 ml of fresh blood. A left lower lobectomy was performed. The resected lung contained a large feeding artery, some acute and partly organizing inflammatory lesions within collapsed lung parenchyma, and massive intra-alveolar hemorrhage in the peripheral area. The patient had an uneventful recovery and was discharged 22 days after his operation.

Aged↗
PubMed2001

Phase I trial of weekly docetaxel combined with cisplatin in patients with non-small cell lung cancer.

The phase I study was conducted to evaluate the maximum tolerated dose (MTD) and toxicity of weekly administered docetaxel combined with cisplatin in patients with non-small-cell lung cancer (NSCLC). In a dose escalation study, 22 patients, under 75 years old, with unresectable and metastatic untreated NSCLC with performance status (0-1) were enrolled. Patients were treated with cisplatin (day 1) and weekly docetaxel (days 1, 8, 15). Dose escalation levels in mg/m(2) were for cisplatin and docetaxel; 70 and 15 (level 1), 80 and 15 (level 2), 80 and 20 (level 3), 80 and 25 (level 4), 80 and 30 (level 5), respectively. Chemotherapy was repeated for at least two cycles every 28 days. All patients were assessable for toxicities. Although grade 3 neutropenia occurred in one case in level 4, there were no significant modifications of chemotherapy schedule until level 4. Grade 3 neutropenia occurred in all cases receiving level 5. One patient developed an infection, and two had incomplete recovery of neutropenia by the 28th day after the first cycle of chemotherapy. Nonhematological toxicities, including nephrotoxicity, nausea/vomiting, alopecia and hypersensitivity reaction, were tolerable. However, one case developed severe hyponatremia. Among 21 patients evaluable for response, eight cases achieved partial response, thus the overall response was 39%. Weekly administration of docetaxel at 25 mg/m(2) (days 1, 8, 15) combined with cisplatin 80 mg/m(2) (day 1) is recommended for phase II studies. The responses observed in the present study suggest an identical high degree of activity against NSCLC with less hematotoxicity compared with a standard schedule of cisplatin and docetaxel.

Adult↗
PubMed2001

Diverse transcriptional initiation revealed by fine, large-scale mapping of mRNA start sites.

Determination of the mRNA start site is the first step in identifying the promoter region, which is of key importance for transcriptional regulation of gene expression. The 'oligo-capping' method enabled us to introduce a sequence tag to the first base of an mRNA by replacing the cap structure of the mRNA. Using cDNA libraries made from oligo-capped mRNAs, we could identify the transcriptional start site of an individual mRNA just by sequencing the 5'-end of the cDNA. The fine mapping of transcriptional start sites was performed for 5880 mRNAs in 276 human genes. Contrary to our expectations, the majority of the genes showed a diverse distribution of transcriptional start sites. They were distributed over 61.7 bp with a standard deviation of 19.5. Our finding may reflect the dynamic nature of transcriptional initiation events of human genes in vivo.

Base Sequence↗
PubMed2001

Independent predictors of restenosis after percutaneous coronary revascularization in haemodialysis patients.

BACKGROUND: Percutaneous balloon angioplasty has become a well-established and routine procedure for coronary revascularization of haemodialysis patients with coronary artery disease. However, the incidence of restenosis after balloon angioplasty is significantly higher in haemodialysis patients than in the general population. We performed a retrospective study comparing balloon angioplasty with coronary stenting in haemodialysis patients. We evaluated the long-term clinical and angiographic outcome after successful percutaneous coronary revascularization in haemodialysis patients. METHODS: A total of 103 consecutive haemodialysis patients (123 lesions) underwent procedurally and clinically successful percutaneous revascularization. Patients were treated with three different strategies: (i) balloon angioplasty in 55 patients (69 lesions); (ii) coronary stenting with balloon angioplasty in 23 patients (25 lesions); and (iii) coronary stenting with rotational atherectomy in 25 patients (29 lesions) who had severely calcified stenotic coronaries. RESULTS: The rates of in-hospital mortality were similar in the three groups. The 1-year incidence of overall events and major adverse cardiac events (MACE) were significantly higher in the balloon group than in the stent with/without rotational atherectomy groups (75% vs 36 and 28%, P<0.01; 71% vs 32 and 28%, P<0.01). Use of coronary stenting (relative risk=0.006, P<0.001) and the presence of calcified coronary lesion (relative risk=68.2, P<0.001) were independent predictors of the 1-year MACE-free survival after percutaneous revascularization. The 3-year MACE-free survival rate was significantly lower in the balloon group than in the stent with/without rotational atherectomy groups (11% vs 33 and 47%, P<0.005 and P<0.001). CONCLUSIONS: This study shows that coronary stenting reduces the incidence of MACE in haemodialysis patients with/without calcified coronary lesions. Moreover, coronary stenting reduces the restenosis rate of both complex and restenotic lesions, and rotational atherectomy prior to coronary stenting reduces the restenosis rate of the severely calcified coronary lesions. These results suggest that coronary stenting with/without rotational atherectomy has led to an improved long-term outcome in the haemodialysis patients with coronary artery disease.

Aged↗
PubMed2001

Quantification of intrahepatic non-uniform distributions for assessing impaired function of liver using 99Tcm-DTPA-galactosyl serum albumin liver SPECT scintigraphy.

Quantitative evaluation of intrahepatic non-uniform distribution was attempted by functional volumetric analysis of liver single photon emission computed tomography (SPECT) scintigraphy using 99Tcm-diethylenetriaminepentaacetic acid galactosyl serum albumin (99Tcm-GSA) (185 MBq). A total of 148 patients were classified into three groups: diffuse liver disease, liver disease with space-occupying lesions, and non-hepatic disease. The volume obtained at the 10% cut-off threshold from reconstructed liver-specific SPECT images was assumed to be the functional total hepatic volume, and the functional volume rates were calculated every 10% threshold width from 10% to 100%. The hepatic distribution index (D index) was calculated from the sum of absolute differences from the control. The hepatic D index in liver cirrhosis was significantly higher than in hepatitis and other diffuse liver diseases, and the index in liver disease with primary malignant neoplasm was significantly higher than in liver disease with metastasis or a benign-space occupying lesion. Additionally, it was significantly negatively correlated with LHL15, and positively correlated with the clinical severity. However, in stages II and III, with which LHL15 did not significantly correlate, the hepatic D index matched the severity of hepatic impairment. The hepatic D index evaluates distribution of functional hepatocytes and may provide a new clinical method for quantitatively assessing hepatic impairment.

Hepatitis↗
PubMed2001

Identification and characterization of the potential promoter regions of 1031 kinds of human genes.

To understand the mechanism of transcriptional regulation, it is essential to identify and characterize the promoter, which is located proximal to the mRNA start site. To identify the promoters from the large volumes of genomic sequences, we used mRNA start sites determined by a large-scale sequencing of the cDNA libraries constructed by the "oligo-capping" method. We aligned the mRNA start sites with the genomic sequences and retrieved adjacent sequences as potential promoter regions (PPRs) for 1031 genes. The PPR sequences were searched to determine the frequencies of major promoter elements. Among 1031 PPRs, 329 (32%) contained TATA boxes, 872 (85%) contained initiators, 999 (97%) contained GC box, and 663 (64%) contained CAAT box. Furthermore, 493 (48%) PPRs were located in CpG islands. This frequency of CpG islands was reduced in TATA(+)/Inr(+) PPRs and in the PPRs of ubiquitously expressed genes. In the PPRs of the CGM2 gene, the DRA gene, and the TM30pl genes, which showed highly colon specific expression patterns, the consensus sequences of E boxes were commonly observed. The PPRs were also useful for exploring promoter SNPs.

Base Sequence↗