Search PubMed⌕ Search

Biomedical subjects

Ryuzo Ueda

Publications and source records attributed to Ryuzo Ueda.

At least 19 recordsLinked to original sources
PubMed2005

ARK5 is transcriptionally regulated by the Large-MAF family and mediates IGF-1-induced cell invasion in multiple myeloma: ARK5 as a new molecular determinant of malignant multiple myeloma.

ARK5, AMP-activated protein kinase (AMPK)-related protein kinase mediating Akt signals, is closely involved in tumor progression, and its stage-associated expression was observed in colorectal cancer. In this study, we found ARK5 expression in multiple myeloma cell lines expressing c-MAF and MAFB. In addition, gene expression profiling of 351 clinical specimens revealed ARK5 expression in primary myelomas expressing c-MAF and MAFB, suggesting that ARK5 may be a transcriptional target of the Large-MAF family. Sequence analysis of the ARK5 gene promoter revealed that it contains two putative MAF-recognition element (MARE) sequences. In support of this hypothesis, ARK5 was induced when an MAFB or c-MAF expression vector was introduced into non-ARK5-expressing colon cancer cells. Furthermore, ARK5 promoter activity was dramatically decreased by mutation or deletion of MARE sequences. Chromatin immunoprecipitation assays revealed an interaction between the Large-MAF family proteins and MARE sequences in the ARK5 promoter. Moreover, in ARK5 mRNA-expressing multiple myeloma lines, but not in ARK5-negative lines, insulin-like growth factor (IGF)-1 increased invasion activity. IGF-1-induced invasion was reproduced when ARK5 was overexpressed in Burkitt's lymphoma and plasmacytoma lines. Based on results, we conclude that ARK5 is a transcriptional target of the Large-MAF family through MARE sequence and that ARK5 may in part mediate the aggressive phenotype associated with c-MAF- and MAFB-expressing myelomas.

Base Sequence↗
PubMed2005

Clinical characteristics and prognostic implications of NPM1 mutations in acute myeloid leukemia.

Recently, somatic mutations of the nucleophosmin gene (NPM1), which alter the subcellular localization of the product, have been reported in acute myeloid leukemia (AML). We analyzed the clinical significance of NPM1 mutations in comparison with cytogenetics, FLT3, NRAS, and TP53 mutations, and a partial tandem duplication of the MLL gene (MLL-TD) in 257 patients with AML. We found NPM1 mutations, including 4 novel sequence variants, in 64 of 257 (24.9%) patients. NPM1 mutations were associated with normal karyotype and with internal tandem duplication (ITD) and D835 mutations in FLT3, but not with other mutations. In 190 patients without the M3 French-American-British (FAB) subtype who were treated with the protocol of the Japan Adult Leukemia Study Group, multivariate analyses showed that the NPM1 mutation was a favorable factor for achieving complete remission but was associated with a high relapse rate. Sequential analysis using 39 paired samples obtained at diagnosis and relapse showed that NPM1 mutations were lost at relapse in 2 of the 17 patients who had NPM1 mutations at diagnosis. These results suggest that the NPM1 mutation is not necessarily an early event during leukemogenesis or that leukemia clones with NPM1 mutations are sensitive to chemotherapy.

Adolescent↗
PubMed2005

Mechanisms for the apoptosis of small cell lung cancer cells induced by anti-GD2 monoclonal antibodies: roles of anoikis.

Anti-GD2 ganglioside antibodies could be a promising, novel therapeutic approach to the eradication of human small cell lung cancers, as anti-GD2 monoclonal antibodies (mAbs) induced apoptosis of small cell lung cancer cells in culture. In this study, we analyzed the mechanisms for the apoptosis of these cells by anti-GD2 mAbs and elucidated the mechanisms by which apoptosis signals were transduced via reduction in the phosphorylation levels of focal adhesion kinase (FAK) and the activation of a MAPK family member, p38, upon the antibody binding. Knock down of FAK resulted in apoptosis and p38 activation. The inhibition of p38 activity blocked antibody-induced apoptosis, indicating that p38 is involved in this process. Immunoprecipitation-immunoblotting analysis of immune precipitates with anti-FAK or anti-integrin antibodies using an anti-GD2 mAb revealed that GD2 could be precipitated with integrin and/or FAK. These results suggested that GD2, integrin, and FAK form a huge molecular complex across the plasma membrane. Taken together with the fact that GD2+ cells showed marked detachment from the plate during apoptosis, GD2+ small cell lung cancer cells seemed to undergo anoikis through the conformational changes of integrin molecules and subsequent FAK dephosphorylation.

Anoikis↗
PubMed2005

Effect of nifedipine on C-reactive protein levels in the coronary sinus and on coronary blood flow in response to acetylcholine in patients with stable angina pectoris having percutaneous coronary intervention.

The effects of nifedipine on inflammation and endothelial function in the coronary circulation were studied in patients who had angina pectoris (n = 17). Long-term treatment with nifedipine (nifedipine CR, 20 mg/day for 4 months) decreased levels of C-reactive protein in the coronary sinus (from 0.35 +/- 0.09 mg/dl to 0.07 +/- 0.01 mg/dl, mean +/- SEM, p <0.05) and enhanced acetylcholine-induced increases in coronary blood flow. Thus, nifedipine is effective in decreasing inflammation and incresing endothelial function in the coronary circulation.

Acetylcholine↗
PubMed2005

Pharmacokinetic and pharmacodynamic comparison of fluoropyrimidine derivatives, capecitabine and 5'-deoxy-5-fluorouridine (5'-DFUR).

PURPOSE: Capecitabine is a three-step prodrug that was rationally designed to be a more effective and safer alternative to its intermediate metabolite, 5'-deoxy-5-fluorouridine (5'-DFUR). We compared the pharmacokinetics/pharmacodynamics of these drugs in metastatic breast cancer patients. METHODS: Six patients received oral capecitabine at 1657 mg/m2 twice daily and 17 received 5'-DFUR at 400 mg three times daily. Both drugs were administered for 21 days followed by a 7-day rest. RESULTS: Median daily 5'-DFUR AUC was significantly higher for capecitabine than for 5'-DFUR (81.1 vs 32.6 mmol h/l; P = 0.01). Following treatment with 5'-DFUR, the median AUC and Cmax of 5'-DFUR tended to be higher in patients with a partial response (3.83 microg h/ml and 4.88 microg/ml) and stable disease (6.46 microg h/ml and 4.96 microg/ml) than in those with disease progression (2.53 microg h/ml and 1.36 microg/ml). The AUC and Cmax of 5'-DFUR was significantly related to overall survival. CONCLUSIONS: These results support the superiority of capecitabine over 5'-DFUR.

Administration, Oral↗
PubMed2005

Enhanced natural killer cell binding and activation by low-fucose IgG1 antibody results in potent antibody-dependent cellular cytotoxicity induction at lower antigen density.

PURPOSE: Recent studies have revealed that fucose removal from the oligosaccharides of human IgG1 antibodies results in a significant enhancement of antibody-dependent cellular cytotoxicity (ADCC) via improved IgG1 binding to FcgammaRIIIa. In this report, we investigated the relationship between enhanced ADCC and antigen density on target cells using IgG1 antibodies with reduced fucose. EXPERIMENTAL DESIGN: Using EL4 cell-derived transfectants with differential expression levels of exogenous human CC chemokine receptor 4 or human CD20 as target cells, ADCC of fucose variants of chimeric IgG1 antibodies specific for these antigens were measured. We further investigated IgG1 binding to natural killer (NK) cells and NK cell activation during ADCC induction to elucidate the mechanism by which low-fucose IgG1 induces ADCC upon target cells with low antigen expression. RESULTS: Low-fucose IgG1s showed potent ADCC at low antigen densities at which their corresponding high-fucose counterparts could not induce measurable ADCC. The quantitative analysis revealed that fucose depletion could reduce the antigen amount on target cells required for constant degrees of ADCC induction by 10-fold for CC chemokine receptor 4 and 3-fold for CD20. IgG1 binding to NK cells was increased by ligating IgG1 with clustered antigen, especially for low-fucose IgG1. Up-regulation of an activation marker, CD69, on NK cells, particularly the CD56(dim) subset, in the presence of both the antibody and target cells was much greater for the low-fucose antibodies. CONCLUSIONS: Our data showed that fucose removal from IgG1 could reduce the antigen amount required for ADCC induction via efficient recruitment and activation of NK cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed2005

Growth inhibition of multiple myeloma cells by a novel IkappaB kinase inhibitor.

Involvement of nuclear factor-kappaB (NF-kappaB) in cell survival and proliferation of multiple myeloma has been well established. In this study we observed that NF-kappaB is constitutively activated in all human myeloma cell lines, thus confirming the previous studies. In addition, we found the phosphorylation of p65 subunit of NF-kappaB in addition to the phosphorylation of IkappaBalpha and the activation of NF-kappaB DNA binding and that various target genes of NF-kappaB including bcl-x(L), XIAP, c-IAP1, cyclin D1, and IL-6 are up-regulated. We then examined the effect of a novel IkappaB kinase inhibitor, 2-amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-piperidin-4-yl nicotinonitrile (ACHP). When myeloma cells were treated with ACHP, the cell growth was efficiently inhibited with IC(50) values ranging from 18 to 35 mumol/L concomitantly with inhibition of the phosphorylation of IkappaBalpha/p65 and NF-kappaB DNA-binding, down-regulation of the NF-kappaB target genes, and induction of apoptosis. In addition, we observed the treatment of ACHP augmented the cytotoxic effects of vincristine and melphalan (l-phenylalanine mustard), conventional antimyeloma drugs. These findings indicate that IkappaB kinase inhibitors such as ACHP can sensitize myeloma cells to the cytotoxic effects of chemotherapeutic agents by blocking the antiapoptotic nature of myeloma cells endowed by the constitutive activation of NF-kappaB.

Cell Proliferation↗
PubMed2005

Production and characterization of an active single-chain variable fragment antibody recognizing CD25.

The alpha subunit of the interleukin-2 receptor (IL-2Ralpha, CD25) is a potential target in therapeutic approaches for hematolopoietic malignancies expressing CD25 on their cell surface, such as adult T cell leukemia/lymphomas. Recent reports have demonstrated that depletion of CD4+CD25+ regulatory T cells with anti-CD25 antibodies may enhance host tumor immunity. We previously raised a mouse monoclonal antibody (mAb), Ta60b mAb (IgG1kappa), specifically recognizing CD25, and an attempt was made here to produce a single chain Fv fragment (scFv) from this mAb as an initial step to development of scFv-based therapeutics. cDNA fragments encoding for the variable regions of the light and heavy chains of the Ta60b mAb were thus isolated by polymerase chain reaction-mediated cloning, and, an expression vector constructed to express Ta60b scFv fused with the maltose binding protein (MBP) in the periplasm of Escherichia coli. The soluble form of MBP-Ta60b fused scFv could be extracted and affinity-purified with an amylose/agarose column, allowing its immunoreactivity to be analyzed by enzyme-linked immunosorbent assay (ELISA), mixed hemadsorption assay, and fluorescence activated cell sorting. In addition, binding activity was studied by competitive ELISA and surface plasmon resonance. The results showed that Ta60b scFv obtained from periplasm retains good reactivity, although its KD value was 4-fold lower than that of the whole Ta60b antibody, suggesting possible clinical use for treatment of patients with CD25-expressing tumors and also for enhancing anti-tumor immunity.

Amino Acid Sequence↗
PubMed2005

Effects of atorvastatin on inflammation and oxidative stress.

Treatment with inhibitors of 3-hydroxyl-3-methylglutaryl coenzyme A reductase (statins) reduces the incidence of cardiovascular events, but it is unclear whether the beneficial effects are mediated solely by their lipid-lowering properties. We therefore investigated whether atorvastatin reduces inflammation and oxidative stress independently of its lipid-lowering effects. The subjects comprised 71 hyperlipidemic patients (64+/-9 years old, mean+/-SD) who were not receiving medical treatment. Serum lipid and C-reactive protein (CRP) levels, and urine 8-isoprostane level (an index of oxidative stress) were measured before and after 4 weeks of treatment with atorvastatin at 10 mg/day. In 38 patients, these biochemical variables and carotid intima-media thickness (IMT) were also measured after 6 months of treatment with atorvastatin. Atorvastatin markedly reduced CRP (from 0.69+/-0.36 to 0.42+/-0.20 and 0.35+/-0.19 mg/l, median+/-median absolute deviation, P<0.0001), 8-isoprostane (from 225+/-99 to 178+/-75 and 179+/-60 ng/g creatinine, P<0.05), and low density-lipoprotein cholesterol (LDLC; from 165+/-21 to 106+/-18 and 112+/-17 mg/dl, P<0.0001) after 4 weeks and 6 months of treatment, respectively. However, the reductions in CRP and 8-isoprostane were not correlated with those of LDLC. After 6 months of treatment, IMT was significantly decreased compared with the baseline value (from 0.94+/-0.26 to 0.90+/-0.20 mm, P<0.05), but this was not correlated with the reduction in LDLC. These results suggest that atorvastatin has beneficial effects on inflammation, oxidative stress, and the lipid profile in patients with hyperlipidemia. The extra-lipid effects are not attributable to the lipid-lowering effect of the statin, suggesting that the pleiotropic effects of atorvastatin are independent of its effects on the lipid profile.

Atorvastatin↗
PubMed2005

Pyogenic granuloma of the stomach successfully treated by endoscopic resection after transarterial embolization of the feeding artery.

Pyogenic granulomas represent the aquisition of vasodilative granulation tissue in the skin or mucosa. They are extremely rare in the alimentary tract, other than in the oral cavity. Here, we report a case of pyogenic granuloma arising from the gastric mucosa. An 82-year-old man was admitted to our hospital because of melena of more than 3 months, duration. Esophagogastroduodenoscopy (EGD) revealed a 30-mm-diameter semipedunculated lesion with an irregular surface in the fundus of the stomach. During hospitalization, the patient's anemia worsened due to loss of blood from the lesion, with the level of hemoglobin declining to 6 g/dl, and a blood transfusion was required. Because radiological and endoscopic findings indicated the lesion was hypervascular, transarterial embolization of the nutritional artery of the lesion was performed before endoscopic resection of the lesion. One week after the embolotherapy, endoscopic mucosal resection was performed, without any complications, such as massive bleeding. Histological studies of the resected specimen revealed many capillaries of various sizes, lined with plump endothelial cells, and accompanied by acute and chronic inflammatory infiltrates. On the basis of these observations, the lesion was diagnosed as a pyogenic granuloma. One year later, the patient was asymptomatic and there was no evidence of tumor recurrence on follow-up EGD.

Aged↗
PubMed2005

Circulating levels of myocardial proteins predict future deterioration of congestive heart failure.

BACKGROUND: This study was designed to test whether circulating levels of myocardium-specific proteins serve as useful markers for the prognosis of patients with congestive heart failure. METHODS AND RESULTS: Seventy-eight patients with congestive heart failure from dilated cardiomyopathy but in a stable condition were enrolled, and their blood was sampled for measurements of myosin light chain-I (MLC-I), troponin T (TnT), heart fatty-acid-binding protein (H-FABP), and creatine kinase isoenzyme MB (CK-MB). The patients were then followed up for 951 +/- 68 days, with the endpoint being acute deterioration. A univariate analysis revealed that MLC-I, TnT, H-FABP, and CK-MB were significant predictors for acute deterioration of heart failure. Application of the Kaplan-Meier method using cutoff values determined by analysis of receiver operating characteristics curves demonstrated that the incidence of acute deterioration was significantly higher in patients with higher values of MLC-I (61.9%), TnT (52.4%), H-FABP (50.0%), or CK-MB (38.6%) than in those with lower values of these markers (15.8%, 20.4%, 13.6%, and 16.1%, respectively). CONCLUSIONS: Increased circulating levels of the specific myocardial proteins are related to a higher probability of future acute deterioration of congestive heart failure in patients in a stable condition associated with dilated cardiomyopathy.

Age Factors↗
PubMed2005

The role of thymidylate synthase and dihydropyrimidine dehydrogenase in resistance to 5-fluorouracil in human lung cancer cells.

The expressions of thymidylate synthase (TS) and intracellular metabolic enzymes have been reported to be associated with the sensitivity and/or resistance to 5-fluorouracil (5-FU). However, since the role of these enzymes in the mechanism of resistance to 5-FU has not been fully examined in lung cancer, in the present study we measured the expression levels of TS, dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), and orotate phosphoribosyltransferase (OPRT) genes in lung cancer cell lines by real-time PCR, and the sensitivity to 5-FU using the MTS assay. The expression of DPD was significantly correlated with the concentration of 5-FU for 50% cell survival in 15 non-small-cell lung cancer (NSCLC) cell lines (p<0.05), but the expressions of TS, TP, and OPRT were not. Treatment with 5-chloro-2,4-dihydroxypyridine, an inhibitor of DPD, altered the sensitivity to 5-FU in DPD-expressing RERF-LC-MT cells, indicating that modulation of DPD activity could increase the 5-FU sensitivity in lung cancer. In contrast, TS expression was dramatically higher in a 5-FU-resistant small-cell lung cancer cell line than in the parent cell line, whereas the expressions of DPD, TP, and OPRT genes were not markedly different. In order to examine the effect of other cytotoxic agents on TS and DPD expression, we compared the expressions of both genes between cisplatin-, paclitaxel-, gemcitabine-, or 7-ethyl-10-hydroxycamptothecin-resistant lung cancer cells and their respective parent cells, but found no differences between any pair of resistant subline and the corresponding parent cell line. Our results indicate that degradation of 5-FU due to DPD is an important determinant in 5-FU sensitivity, while induction of TS contributes to acquired resistance against 5-FU in lung cancer. Therefore, the expression levels of TS and DPD genes may be useful indicators of 5-FU activity in lung cancer.

Antimetabolites, Antineoplastic↗
PubMed2005

p16/INK4a gene methylation is a frequent finding in pulmonary MALT lymphomas at diagnosis.

p16/INK4a gene alterations have been associated with tumor progression in lymphoid malignancies. However, their significance in mucosa-associated lymphoid tissue (MALT) lymphoma is unclear. We investigated p16 gene methylation and mutation in a large series of untreated cases of pulmonary MALT lymphoma and diffuse large B-cell lymphoma (DLBL), and correlated p16 gene alterations with a MALT lymphoma-specific API2-MALT1 fusion and the clinicopathologic features of MALT lymphoma. The API2-MALT1 fusion was detected by multiplex reverse transcription polymerase chain reaction in 25/60 (42%) cases of MALT lymphoma, but none of 11 DLBLs. Methylation-sensitive single-strand conformation analysis showed that p16 gene methylation was frequently detected in 36/60 (60%) cases of MALT lymphoma. The gene was similarly methylated in DLBL cases (6/11, 55%). A p16 gene mutation was found in one (p16 gene-methylation) of 44 MALT lymphomas and in none of six diffuse large B-cell lymphomas. Statistical analysis showed that the p16 gene methylation status did not correlate with API2-MALT1 fusion or any of the clinicopathologic factors including serum LDH, clinical stage, and increased large cells. These findings suggest that p16 methylation is not associated with tumor progression, but may be an early event in MALT lymphomagenesis that might be maintained through the progression of the tumor.

Adult↗
PubMed2005

Impact of occult hepatitis B virus infection on efficacy and prognosis of interferon-alpha therapy for patients with chronic hepatitis C.

BACKGROUND/AIMS: It is reported that some patients with undetectable hepatitis B surface antigen (HBsAg) have serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis C (HCV). The aim of this study was to elucidate the impact of occult HBV infection on the efficacy and prognosis of interferon-alpha (IFN) therapy in HCV patients. METHODS: One hundred and forty HCV patients without HBsAg who received IFN therapy were studied. Serum HBV DNA was quantified by real-time detection polymerase chain reaction. RESULTS: Of 140 patients, 11 (7.9%) were HBV DNA-positive before IFN therapy. The serum HBV DNA levels ranged from 106 to 884 copies/ml. Four of these 11 patients showed a sustained virologic response by IFN, compared with 39 of 129 without HBV DNA (P = NS). Interestingly, two of the 11 patients developed hepatocellular carcinoma (HCC) after therapy, compared with 16 of 129 without HBV DNA (P = NS). In the serial study, serum HBV DNA was transiently undetectable during and after IFN; however, most became positive during follow-up. CONCLUSIONS: Occult HBV infection may not have a significant impact on response to IFN therapy for chronic HCV and development of HCC after therapy. Occult HBV may be sensitive to IFN although HBV is not completely eradicated.

Adult↗
PubMed2005

Differences of hepatocellular carcinoma patients with hepatitis B virus genotypes of Ba, Bj or C in Japan.

Hepatitis B virus (HBV) genotypes B (HBV/B) and C (HBV/C) are prevalent in Asia. Recently HBV/B has been classified into two subtypes, HBV/Ba which is ubiquitously found in Asia, and HBV/Bj which is specific in Japan. In addition, the frequency of positive HBeAg has been reported to be higher in patients with HBV/Ba than those with HBV/Bj. However, little is known about the differences between patients with various genotypes who developed hepatocellular carcinoma (HCC). In 296 serum samples of HCC patients collected from all over Japan, HBV genotypes were determined with the restriction fragment length polymorphism. HBV/A was detected in 1.0%, HBV/Ba in 4.4%, HBV/Bj in 7.4%, and HBV/C in 86.5%. In the Tohoku district and Okinawa, HBV/Ba, HBV/Bj and HBV/C were found in 6.7, 40.0 and 48.9%, compared to 4.0, 1.6 and 93.2% in the other districts in Japan. HBV/Bj patients were more frequently found in the group older than 65 years while HBV/Ba patients were found in all age groups. The frequency of positive HBeAg in HBV/Bj patients was significantly low compared to that in the other patients. More than 60% of the patients with HCC had cirrhosis as the underlying liver diseases. However, in HBV/Ba patients aged 50 years or younger, 80% of them had chronic hepatitis, while 87.5% of those aged older than 50 years had cirrhosis. These data suggest that great differences exist among patients with HCC infected with different genotypes.

Adult↗
PubMed2005

Detection of API2-MALT1 fusion transcripts in cytologic specimens of patients with pulmonary mucosa-associated lymphoid tissue lymphoma.

Mucosa-associated lymphoid tissue (MALT) lymphoma constitutes up to 90% of primary pulmonary lymphomas, but its diagnosis is often difficult. API2-MALT1 fusion is specific to MALT lymphoma and is detected in nearly half of the pulmonary cases. Cytologic examinations have played a pivotal role in the diagnosis of pulmonary tumors; however, cytologic specimens have only infrequently been used for molecular studies. In this study, we performed a multiplex reverse transcription-polymerase chain reaction (RT-PCR) assay to detect the API2-MALT1 fusion transcript in archival cytologic specimens used as RNA sources. We studied 3 pulmonary MALT lymphoma cases that were positive for the fusion gene as detected with RNA extracted from diagnostic histologic specimens. In 1 case, a conventional PCR clonality assay for the immunoglobulin heavy chain gene rearrangement failed to detect the monoclonality. In all 3 cases, the fusion transcript was successfully detected in the cytologic specimens of sputum, bronchoalveolar lavage fluid, bone marrow smears, and pleural effusions. This finding suggests that such specimens can be used as RNA sources in multiplex RT-PCR assays for the API2-MALT1 fusion transcript. The detection of API2-MALT1 fusion as carried out with these specimens would be useful as an ancillary assay for the diagnosis, staging, and follow-up of pulmonary MALT lymphoma.

Aged↗
PubMed2005

Spontaneous hepatic rupture due to metastatic tumor of lung adenocarcinoma.

A 64-year-old man diagnosed as lung adenocarcinoma with hepatic tumor was admitted to our hospital. He carried the hepatitis B virus but was negative for PIVKA-II and alpha-fetoprotein, and hence we diagnosed a case of stage IV lung adenocarcinoma. We planned to administer systemic chemotherapy, but he experienced sudden-onset abdominal discomfort accompanied with decreased blood pressure. We diagnosed hemorrhagic ascites due to spontaneous rupture of the liver tumor. Emergency angiography and therapeutic embolization stabilized his clinical condition. Hemorrhagic ascites due to metastatic liver tumor is rare and the sudden onset of abdominal symptoms is an indicator of rupture.

Adenocarcinoma↗