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Dive into the research topics where Sakae Itoga is active.

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Featured researches published by Sakae Itoga.


Journal of Gastroenterology and Hepatology | 2001

Prevalence of vaccine-induced escape mutants of hepatitis B virus in the adult population in China: a prospective study in 176 restaurant employees.

Chuan He; Fumio Nomura; Sakae Itoga; Kazumasa Isobe; Toshiaki Nakai

Background and Aim: Hepatitis B virus (HBV) variants with mutations in the S gene would pose a substantial risk to the community as current HBV vaccines are not effective in preventing infection with them. The majority of such vaccine escape mutants so far reported have been found while studying vertical transmission of HBV; the vaccine failure rate in connection with vaccine escape mutants in adults is not clear at the moment. The purpose of this study was to evaluate the efficacy of immunization against HBV in the adult population by analysis using polymerase chain reaction (PCR) to detect HBV‐DNA, and also to elucidate the type of mutation encountered in vaccine failure cases.


Frontiers in Bioscience | 2009

c-myc suppressor FBP-interacting repressor for cancer diagnosis and therapy

Kazuyuki Matsushita; Takeshi Tomonaga; Toshiko Kajiwara; Hideaki Shimada; Sakae Itoga; Takaki Hiwasa; Shuji Kubo; Takenori Ochiai; Hisahiro Matsubara; Fumio Nomura

Based on the genetic background of cancer, we have been trying to develop novel diagnostic and therapeutic strategies against human cancers. c-myc gene activation has been detected in many human cancers, indicating a key role of c-myc in tumor development. Thus targeting c-myc gene suppression is a promising strategy for cancer treatment. Recently, an interaction between FIR (FUSE-Binding Protein-Interacting Repressor) and TFIIH/p89/XPB helicase was found to repress c-myc transcription and so might be important for suppressing tumor formation. Previously, we have shown that the expression of splicing variant of FIR is elevated in colorectal cancer tissues and promotes tumor development by disabling FIR-repression to sustain high levels of c-Myc, opposing apoptosis in cancer cells. In this study, FIR recombinant adenovirus vector induces tumor growth suppression against tumor xenografts in animal model experiment. Together, one clue to the development of cancer diagnosis and therapies directed against c-Myc may go through FIR and its splicing variant.


Scandinavian Journal of Gastroenterology | 2010

Risk of Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Virus Infection

Kenichi Ito; Makoto Arai; Fumio Imazeki; Yutaka Yonemitsu; Dan Bekku; Tatsuo Kanda; Keiichi Fujiwara; Kenichi Fukai; Kenichi Sato; Sakae Itoga; Fumio Nomura; Osamu Yokosuka

Abstract Objective. To determine the risk factors for the occurrence of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV) infection. Material and methods. A total of 620 patients who tested positive for hepatitis B surface antigen and were referred to Chiba University Hospital between February 1985 and March 2008 were included in the study and the following characteristics were analyzed: age, gender, status of hepatitis B e antigen, alanine aminotransferase level, HBV DNA level, and number of platelets (PLTs). Results. HCC was detected in 30 cases during the follow-up period (5.4 ± 5.1 years). Multivariate analysis revealed that age > 40 years [compared with patients aged < 40 years; odds ratio (OR) = 4.28; 95% confidence interval (CI) = 1.68–10.9] and PLT level < 206,000/μl (compared with patients with a higher PLT level; OR = 8.50; 95% CI = 1.98–36.2) were predictive factors for HCC occurrence. In patients aged > 40 years, the HBV DNA level (compared with < 5.0 log copies/ml; OR = 4.22, 95% CI = 1.13–15.8) and PLT level (compared with patients with > 196,000/μl PLTs; OR = 15.6, 95% CI = 2.06–118.3) were predictive factors for HCC occurrence. Conclusions. Advanced age and low PLT level were risk factors for HCC occurrence in patients with HBV infection. In patients aged > 40 years, viral load was also a risk factor for HCC.


Journal of Gastroenterology and Hepatology | 1999

Transfusion-transmitted virus infection in China: prevalence in blood donors and in patients with liver diseases.

Chuan He; Fumio Nomura; Nobuyasu Yukimasa; Sakae Itoga; Maki Yamada-Osaki; Ryo Sumazaki; Toshiaki Nakai

Background : Prevalence of transfusion‐transmitted virus (TTV) infection among blood donors and in patients with liver diseases in China was studied.


Journal of Thoracic Oncology | 2014

Transbronchial Biopsy Needle Rinse Solution Used for Comprehensive Biomarker Testing in Patients with Lung Cancer

Yuichi Sakairi; Kenichi Sato; Sakae Itoga; Fumie Saegusa; Kazuyuki Matsushita; Takahiro Nakajima; Shigetoshi Yoshida; Yuichi Takiguchi; Fumio Nomura; Ichiro Yoshino

Introduction: Although genetic information is essential for molecular targeted therapy for personalized medicine, tissue sampling for genetic analysis remains challenging. We investigated the utility of bronchoscopic sampling in non–small-cell lung cancer (NSCLC) patients compared with conventional histological materials for multiple genetic analyses. Methods: Patients with NSCLC proven by onsite cytological evaluation during bronchoscopic survey were eligible for this study. After conventional needle aspiration biopsy by flexible bronchofiberscopy of primary lesions or convex-probe endobronchial ultrasound of lymph nodes, the used needle was rinsed with saline, and the ultra-microsample (uMS) was used for cytological diagnosis and genetic analysis. Gene mutations and fusion genes were examined by high-resolution melting analysis and direct sequencing. The results from the uMS and those from conventional histological samples were compared. Results: A total of 134 lesions (48 primary and 86 metastatic) were analyzed. Adenocarcinoma (n = 80), squamous-cell carcinoma (n = 43), and NSCLC (n = 11) samples were pathologically confirmed in histological cores; however, malignancies were detected in only 45 (34%) of the corresponding uMS. In 62 samples, genetic disorders, including epidermal growth factor receptor (n = 21), K-ras (n = 11), and BRAF mutations (n = 1); anaplastic lymphoma kinase (n = 5), receptor tyrosine kinase (n = 1), and RET fusion genes (n = 1); and silent mutations (n = 22), were identified. In total, 1474 molecular tests were performed, and 1464 tests (99.3%) were identical for both histological samples and uMS. Conclusion: Bronchoscopic uMS (biopsy needle rinsed fluids) are useful for multiple genetic examinations in NSCLC.


Journal of Gastroenterology and Hepatology | 2011

Long-term follow-up of patients with hepatitis B e antigen negative chronic hepatitis B

Dan Bekku; Makoto Arai; Fumio Imazeki; Yutaka Yonemitsu; Tatsuo Kanda; Keiichi Fujiwara; Kenichi Fukai; Kenichi Sato; Sakae Itoga; Fumio Nomura; Osamu Yokosuka

Background and Aim:  After hepatitis B virus (HBV) e antigen (HBeAg) seroconversion, HBV‐DNA continues to replicate, and HBeAg‐negative patients still face the risk of liver disease progression. We investigated the predictive factors for alanine aminotransferase (ALT) elevation, antiviral drug use, and hepatocellular carcinoma (HCC) occurrence in HBeAg‐negative patients.


Alcoholism: Clinical and Experimental Research | 2004

Comparative analyses of four different methods of genotyping ALDH2.

Sakae Itoga; Toru Nanmoku; Takayuki Uchimoto; Masahiko Sunaga; Masahiko Nezu; Takeshi Tomonaga; Shoji Harada; Fumio Nomura

BACKGROUND A number of methods of genotyping single nucleotide polymorphisms (SNPs) are currently available, ranging from the traditional restriction fragment length polymorphism (RFLP) and single-stranded conformational polymorphism (SSCP) to more sophisticated technologies. We determined the utility of three novel methods by genotyping aldehyde dehydrogenase-2 (ALDH2). METHODS DNA was isolated from blood samples of 241 control subjects and 74 patients with esophageal cancer. The utility of three novel genotyping methods-melting curve analysis using a LightCycler, SNaPshot analysis using an ABI PRISM 310 genetic analyzer, and denaturing high-performance liquid chromatography using a WAVE DNA fragment analysis system-were compared with that of conventional fluorescent-based polymerase chain reaction (PCR)-SSCP using an ALF express DNA sequencer. RESULTS The frequency of the mutant ALDH2*2 allele was significantly higher in patients with esophageal cancer (27.7%) than in control subjects (16.2%; p < 0.01; habitual alcohol drinkers). The melting curve analysis was accurate, more rapid, and easier to use than the SNaPshot analysis or denaturing high-performance liquid chromatography analysis. Fluorescent-based PCR-SSCP proved useful for analyzing a large number of samples. CONCLUSION Melting curve analysis using the LightCycler is suitable for the genotyping of small numbers of samples in a routine clinical setting; fluorescent-based PCR-SSCP analysis using the ALF express DNA sequencer can be used for large-scale genotyping in epidemiologic studies.


Critical Care | 2014

Omeprazole-associated rhabdomyolysis

Kumiko Tanaka; Taka-aki Nakada; Ryuzo Abe; Sakae Itoga; Fumio Nomura; Shigeto Oda

No abstract


Cancer Science | 2013

SAP155‐mediated c‐myc suppressor far‐upstream element‐binding protein‐interacting repressor splicing variants are activated in colon cancer tissues

Toshiko Kajiwara; Kazuyuki Matsushita; Sakae Itoga; Mai Tamura; Nobuko Tanaka; Takeshi Tomonaga; Hisahiro Matsubara; Hideaki Shimada; Yasuaki Habara; Masafumi Matsuo; Fumio Nomura

The c‐myc transcriptional suppressor, far‐upstream element (FUSE)‐binding protein (FBP)‐interacting repressor (FIR), is alternatively spliced in colorectal cancer tissue (Matsushita et al., Cancer Res 2006). Recently, the knockdown of SAP155 pre‐mRNA‐splicing factor, a subunit of SF3b, was reported to disturb FIR pre‐mRNA splicing and yield FIRΔexon2, an exon 2‐spliced variant of FIR, which lacks c‐myc repression activity. In the present study, novel splicing variants of FIR, Δ3 and Δ4, were also generated by SAP155 siRNA, and these variants were found to be activated in human colorectal cancer tissue. Furthermore, the expression levels of FIR variant mRNA were examined in the peripheral blood of colorectal cancer patients and healthy volunteers to assess its potency for tumor detection. As expected, circulating FIR variant mRNA in the peripheral blood of cancer patients were significantly overexpressed compared to that in healthy volunteers. In particular, the area under the receiving operating characteristic curve of FIR, FIRΔexon2 or FIRΔexon2/FIR, was greater than those of conventional carcinoembryonic antigen or carbohydrate antigen 19‐9. In addition, FIRΔexon2 or FIR mRNA expression in the peripheral blood was significantly reduced after operative removal of colorectal tumors. Thus, circulating FIR and FIRΔexon2 mRNA are potential novel screening markers for colorectal cancer testing with conventional carcinoembryonic antigen and or carbohydrate antigen 19‐9. Taken together, our results indicate that overexpression of FIR and its splicing variants in colorectal cancer directs feed‐forward or addicted circuit c‐myc transcriptional activation. Clinical implications for colorectal cancers of novel FIR splicing variants are also discussed in the present paper.


Alcoholism: Clinical and Experimental Research | 2013

Combined Proteomic Analysis of Liver Tissue and Serum in Chronically Alcohol‐Fed Rats

Mako Yamada; Mamoru Satoh; Masanori Seimiya; Kazuyuki Sogawa; Sakae Itoga; Takeshi Tomonaga; Fumio Nomura

BACKGROUND Proteomic approaches may provide new insights into pathological conditions associated with alcoholism. The aim of this study was to conduct a proteomic analysis of liver tissue and serum in chronically alcohol-fed rats using agarose 2-dimensional gel electrophoresis (2-DE) and 3-step serum proteome analysis. METHODS A total of 12 rats were pair-fed nutritionally adequate liquid diet containing ethanol as 36% of the total energy or an isocaloric control diet for 2 months. Rat liver homogenates and cytosol fractions were subjected to agarose 2-DE. Serum samples were subjected to 3-step serum proteome analysis involving immunodepletion of abundant proteins followed by fractionation using reverse-phase high-performance liquid chromatography and 1-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Candidate proteins were digested with trypsin and identified using mass spectrometry. Observed differences in protein expression levels were confirmed using Western blotting. RESULTS A total of 46 protein spots were found to be differentially expressed in the liver homogenates and cytosol fractions of alcohol-fed rats relative to pair-fed controls. The most notable change was down-regulation of a 29-kDa protein, which was subsequently identified as carbonic anhydrase III (CA III). Down-regulation of this protein in alcohol-fed rats was confirmed by Western blotting. The messenger RNA level of CA III was decreased as well. In rat serum, a total of 41 proteins were differentially expressed. Of these proteins, only betaine-homocysteine methyltransferase (BHMT) was also found to be differentially expressed in the liver. CONCLUSIONS A combined proteomic analysis of liver tissue and serum in chronically alcohol-fed rats revealed that the expression of CA III is significantly down-regulated in the liver of alcohol-fed rats. Our results also showed that BHMT expression is up-regulated in both the liver and serum of alcohol-fed rats.

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