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Dive into the research topics where Takashi Muramoto is active.

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Featured researches published by Takashi Muramoto.


Journal of Gastroenterology | 2006

Late toxicity in complete response cases after definitive chemoradiotherapy for esophageal squamous cell carcinoma

Yosuke Kumekawa; Kazuhiro Kaneko; Hiroaki Ito; Toshinori Kurahashi; Kazuo Konishi; Atsushi Katagiri; Taikan Yamamoto; Meiko Kuwahara; Yutaro Kubota; Takashi Muramoto; Yoshihide Mizutani; Michio Imawari

BackgroundWe retrospectively investigated long-term toxicity after concurrent chemoradiotherapy (CRT) for patients with esophageal squamous cell carcinoma (ESCC).MethodsConcurrent chemoradiotherapy was performed in 110 patients with T1 to T4 disease containing M1 lymph node (LYM) disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil 400 mg/m2 per 24 h on days 1 to 5 and 8 to 12, combined with 2-h infusion of cisplatin 40 mg/m2 on days 1 and 8. Radiation treatment of the mediastinum at a dose of 30 Gy in 15 fractions was administered concomitantly with chemotherapy. A course schedule with a 3-week treatment and a 2-week break was applied twice, with a total radiation dose of 60 Gy. For the assessment of toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring schema was adopted.ResultsA total of 81 patients were recruited in patients with stage I to IVA. Of 34 patients with complete response, 1 patient died as a result of acute myocardial infarction. Grade 2, 3, and 4 late toxicities occurred with the following incidences: pericarditis in 3 patients, 1 patient, and 2 patients, respectively; heart failure in 0, 0, and 3 patients; pleural effusion in 2, 3, and 0 patients; and radiation pneumonitis in 0, 0, and 1 patient, respectively.ConclusionsDefinitive chemoradiotherapy for ESCC is effective with substantial toxicities. Further investigation is warranted to minimize the normal tissue toxicities.


The American Journal of Gastroenterology | 2011

Clinicopathological and Molecular Features of Colorectal Serrated Neoplasias With Different Mucosal Crypt Patterns

Yuichiro Yano; Kazuo Konishi; Toshiko Yamochi; Atsushi Katagiri; Hisako Nozawa; Hiromu Suzuki; Minoru Toyota; Yutaro Kubota; Takashi Muramoto; Yoshiya Kobayashi; Masayuki Tojo; Kenichi Konda; Reiko Makino; Kazuhiro Kaneko; Nozomi Yoshikawa; Hidekazu Ota; Michio Imawari

OBJECTIVES:Endoscopic examination shows that serrated neoplasias (SNs), such as serrated adenomas and sessile serrated adenomas, exhibit different mucosal crypt patterns. However, it remains unclear whether advanced serrated polyps with different mucosal crypt patterns have different clinicopathological or molecular features.METHODS:We classified the mucosal crypt patterns of 86 SNs into three types (hyperplastic, adenomatous, and mixed pattern) and evaluated their clinicopathological and molecular features.RESULTS:We found significant differences in the proliferative activity status between SNs with mixed/adenomatous patterns and those with the hyperplastic patterns. SNs with the hyperplastic pattern were frequently located in the proximal colon and had a macroscopically superficial appearance, whereas SNs with the adenomatous pattern were often located in the distal colon and had a protruding appearance. Furthermore, a significant difference was observed in the frequency of the CpG island methylator phenotype (CIMP), involving the methylation of two or more CIMP-related genes (MINT1, MINT2, MINT31, p16, and MLH1), between SNs with the hyperplastic pattern and those with the mixed/adenomatous patterns (18/32 (56%) vs. 8/28 (29%) or 7/26 (27%); P=0.0309 or P=0.0249, respectively). Moreover, the prevalence of KRAS mutations was significantly higher in SNs with the adenomatous pattern than in those with the hyperplastic pattern (7/26 (27%) vs. 1/32 (3%); P=0.0173). In comparison with other patterns, the mixed pattern was detected more frequently in mixed serrated polyps (MSPs), which contain separate histological components. Some MSPs exhibited concordant molecular alterations among the different histological components.CONCLUSIONS:The clinicopathological and molecular features of SNs correlated strongly with their mucosal crypt patterns, which were observed using chromoendoscopy.


PLOS ONE | 2014

Distinct molecular features of different macroscopic subtypes of colorectal neoplasms.

Kenichi Konda; Kazuo Konishi; Toshiko Yamochi; Yoichi M. Ito; Hisako Nozawa; Masayuki Tojo; Kensuke Shinmura; Mari Kogo; Atsushi Katagiri; Yutaro Kubota; Takashi Muramoto; Yuichiro Yano; Yoshiya Kobayashi; Toshihiro Kihara; Teppei Tagawa; Reiko Makino; Masafumi Takimoto; Michio Imawari; Hitoshi Yoshida

BACKGROUND Colorectal adenoma develops into cancer with the accumulation of genetic and epigenetic changes. We studied the underlying molecular and clinicopathological features to better understand the heterogeneity of colorectal neoplasms (CRNs). METHODS We evaluated both genetic (mutations of KRAS, BRAF, TP53, and PIK3CA, and microsatellite instability [MSI]) and epigenetic (methylation status of nine genes or sequences, including the CpG island methylator phenotype [CIMP] markers) alterations in 158 CRNs including 56 polypoid neoplasms (PNs), 25 granular type laterally spreading tumors (LST-Gs), 48 non-granular type LSTs (LST-NGs), 19 depressed neoplasms (DNs) and 10 small flat-elevated neoplasms (S-FNs) on the basis of macroscopic appearance. RESULTS S-FNs showed few molecular changes except SFRP1 methylation. Significant differences in the frequency of KRAS mutations were observed among subtypes (68% for LST-Gs, 36% for PNs, 16% for DNs and 6% for LST-NGs) (P<0.001). By contrast, the frequency of TP53 mutation was higher in DNs than PNs or LST-Gs (32% vs. 5% or 0%, respectively) (P<0.007). We also observed significant differences in the frequency of CIMP between LST-Gs and LST-NGs or PNs (32% vs. 6% or 5%, respectively) (P<0.005). Moreover, the methylation level of LINE-1 was significantly lower in DNs or LST-Gs than in PNs (58.3% or 60.5% vs. 63.2%, P<0.05). PIK3CA mutations were detected only in LSTs. Finally, multivariate analyses showed that macroscopic morphologies were significantly associated with an increased risk of molecular changes (PN or LST-G for KRAS mutation, odds ratio [OR] 9.11; LST-NG or DN for TP53 mutation, OR 5.30; LST-G for PIK3CA mutation, OR 26.53; LST-G or DN for LINE-1 hypomethylation, OR 3.41). CONCLUSION We demonstrated that CRNs could be classified into five macroscopic subtypes according to clinicopathological and molecular differences, suggesting that different mechanisms are involved in the pathogenesis of colorectal tumorigenesis.


Journal of Clinical Gastroenterology | 2010

Does daily alcohol and/or cigarette consumption cause low-grade dysplasia, a precursor of esophageal squamous cell carcinoma?

Kazuhiro Kaneko; Yoshitaka Murakami; Atsushi Katagiri; Kazuo Konishi; Yutaro Kubota; Takashi Muramoto; Miki Kushima; Atsushi Ohtsu; Michio Imawari

Background Cigarette smoking and alcohol consumption are well-known risk factors for esophageal squamous cell carcinoma (ESCC), which has a very poor prognosis. Successful screening strategies for precursor lesions that can be targets for early detection and treatment are required to prevent ESCC. Methods This is a prospectively cross-sectional study. To clarify whether daily smoking and/or alcohol consumption are risk factors for dysplasia, which is the initial lesion leading to ESCC. Lugol chromoendoscopy was performed in 1345 eligible individuals. Six hundred ninety individuals had daily smoking and/or alcohol consumption; 655 individuals did not smoke and drink alcohol. The effects of smoking and alcohol consumption among high-grade dysplasia (HGD), low-grade dysplasia (LGD), and controls without dysplasia were evaluated using multiple logistic regression analysis. Results Among 1345 individuals, 17 HGD and 23 LGD lesions were confirmed histologically. The prevalence of both smoking and drinking consumption was significantly higher in HGD than in LGD individuals (age and sex adjusted odds ratio; 113.0, 95% confidence interval; 6.26), whereas no significant difference was seen in both consumption between LGD individuals and controls (odds ratio; 1.29, 95% confidence interval; 0.33-6.37). Approximately 70% of HGD individuals, but only 13% of LGD individuals, both smoked and consumed alcohol. Conclusions Daily cigarette and alcohol consumption were not the risk factors for LGD, however, consumption of both were high-risk factors for HGD. We suggest that documenting the difference of risk factors for LGD and HGD can assist in the development of effective screening, early detection, and prevention strategies for ESCC.


Endoscopy International Open | 2014

Molecular features of colorectal polyps presenting Kudo's type II mucosal crypt pattern: are they based on the same mechanism of tumorigenesis?

Kensuke Shinmura; Kazuo Konishi; Toshiko Yamochi; Yutaro Kubota; Yuichiro Yano; Atsushi Katagiri; Takashi Muramoto; Toshihiro Kihara; Masayuki Tojo; Kenichi Konda; Teppei Tagawa; Fumito Yanagisawa; Mari Kogo; Reiko Makino; Masafumi Takimoto; Hitoshi Yoshida

Background and study aims: The molecular features of serrated polyps (SPs) with hyperplastic crypt pattern, also called Kudo’s type II observed by chromoendoscopy, were evaluated. Methods: The clinicopathological and molecular features of 114 SPs with a hyperplastic pit pattern detected under chromoendoscopy (five dysplastic SPs, 63 sessile serrated adenoma/polyps (SSA/Ps), 36 microvesicular hyperplastic polyps (MVHPs), and 10 goblet cell-rich hyperplastic polyps (GCHPs)) were examined. The frequency of KRAS and BRAF mutations and CpG island methylator phenotype (CIMP) were investigated. Results: Dysplastic SPs and SSA/Ps were frequently located in the proximal colon compared to others (SSA/Ps vs. MVHPs or GCHPs, P < 0.0001). No significant difference was found in the frequency of BRAF mutation among SPs apart from GCHP (60 % for dysplastic SPs, 44 % for SSA/Ps, 47 % for MVHPs, and 0 % for GCHPs). The frequency of CIMP was higher in dysplastic SPs or SSA/Ps than in MVHPs or GCHPs (60 % for dysplastic SPs, 56 % for SSA/Ps, 32 % for MVHPs, and 10 % for GCHPs) (SSA/Ps vs. GCHP, P = 0.0068). When serrated neoplasias (SNs) and MVHPs were classified into proximal and distal lesions, the frequency of CIMP was significantly higher in the proximal compared to the distal SNs (64 % vs. 11 %, P = 0.0032). Finally, multivariate analysis showed that proximal location and BRAF mutation were significantly associated with an increased risk of CIMP. Conclusions: Distinct molecular features were observed between proximal and distal SPs with hyperplastic crypt pattern. Proximal MVHPs may develop more frequently through SSA/Ps to CIMP cancers than distal MVHPs.


World Journal of Gastrointestinal Pathophysiology | 2011

Right colon cancer presenting as hemorrhagic shock

Tomoyuki Iwata; Kazuo Konishi; Takahisa Yamazaki; Katsuya Kitamura; Atsushi Katagiri; Takashi Muramoto; Yutaro Kubota; Yuichiro Yano; Yoshiya Kobayashi; Toshiko Yamochi; Nobuyuki Ohike; Masahiko Murakami; Takehiko Gokan; Nozomi Yoshikawa; Michio Imawari

A 67-year-old man visited our hospital with a history of continuous hematochezia leading to hemorrhagic shock. An abdominal computed tomography scan revealed a large mass in the ascending colon invading the duodenum and pancreatic head as well as extravasation of blood from the gastroduodenal artery (GDA) into the colon. Colonoscopy revealed an irregular ulcerative lesion and stenosis in the ascending colon. Therefore, right hemicolectomy combined with pylorus-preserving pancreaticoduodenectomy was performed. Histologically, the tumor was classified as a moderately differentiated adenocarcinoma. Moreover, cancer cells were mainly located in the colon but had also invaded the duodenum and pancreas and involved the GDA. Immunohistochemically, the tumor cells were positive for cytokeratin (CK)20 and carcinoembryonic antigen (CEA) but not for CK7 and carbohydrate antigen (CA)19-9. The patient died 23 d after the surgery because he had another episode of arterial bleeding from the anastomosis site. Although En bloc resection of the tumor with pancreaticoduodenectomy and colectomy performed for locally advanced colon cancer can ensure long-term survival, patients undergoing these procedures should be carefully monitored, particularly when the tumor involves the main artery.


Digestion | 2018

Efficacy of Upper Gastrointestinal Endoscopic Examination to Identify Patients with Obstructive Sleep Apnea Syndrome: A Retrospective Cross-Sectional Study

Ken Ohata; Eiji Sakai; Tomomi Nakao; Yoshiaki Kimoto; Rindo Ishii; Takafumi Konishi; Sayaka Ueno; Maiko Takita; Ryoju Negishi; Tatsuo Morinushi; Takashi Muramoto; Nobuyuki Matsuhashi; Teruo Nakaya; Ikuro Koba; Shigeyuki Nakaji

Background/Aims: Despite the high prevalence of obstructive sleep apnea syndrome (OSAS), most individuals are unaware of its diagnosis. We assessed whether an upper gastrointestinal (GI) endoscopy can accurately predict the incidence of OSAS. Methods: After endoscopic evaluation of laryngo-pharyngeal collapse, a total of 154 subjects with laryngo-pharyngeal collapse and 52 control subjects underwent polysomnography. Based on the modified Fujita Classification, upper airway obstruction was classified into 3 different types: oropharyngeal, supraglottic and combined type, and associations between upper airway obstruction and OSAS were evaluated. Results: Of 154 subjects with laryngo-pharyngeal collapse, 108 (70.1%) were diagnosed as OSAS, while only 4 (7.7%) control subjects were diagnosed as OSAS (p < 0.001). The sensitivity and specificity of endoscopic diagnosis were 96.4 and 51.1%, respectively. Oropharyngeal involvement was frequently found in 90.2% of the subjects (139/154). The severity of upper airway obstruction was significantly correlated with the apnea-hypopnea index score (r = 0.55, p < 0.001). A multivariate logistic regression analysis revealed that a male sex (OR 5.20; 95% CI 2.65–10.2, p < 0.001), body mass index ≥25 kg/m2 (OR 4.98; 95% CI 2.23–11.2, p = 0.02) and severe obstruction (OR 7.79; 95% CI 3.34–18.2, p < 0.001) were significant independent predictors of severe OSAS. Conclusion: A conventional upper GI endoscopic examination might be useful as a diagnostic modality for OSAS.


Gastroenterology | 2013

Sa1683 Five Different Subclasses of Colorectal Neoplasias Identified by Integrated Genetic and Epigenetic Analysis: Association With Polypoid and Nonpolypoid Carcinogenesis

Kenichi Konda; Kazuo Konishi; Atsushi Katagiri; Masayuki Tojo; Yutaro Kubota; Takashi Muramoto; Yuichiro Yano; Yoshiya Kobayashi; Toshihiro Kihara; Kensuke Shinmura; Teppei Tagawa; Toshiko Yamochi; Y. Ito; Michio Imawari; Hitoshi Yoshida

Background: Tumor necrosis factor-α (TNF-α) is a pro-inflammatory cytokine that is highly up-regulated in inflammatory bowel disease and reduces the expression of the intestinal specific homeodomain transcription factor, CDX2. CDX2 is a master regulator of the intestinal homeostasis and is considered to be a tumor suppressor. WNT/ β-catenin signaling is critical for intestinal cell proliferation, but decreased CDX2 expression contributes to an abnormal increased activation of WNT signaling and progression of cancer. Furthermore, low CDX2 expression is associated with enhanced epithelial-to-mesenchymal transition (EMT) in colorectal cancer (CRC). Inflammation is often observed at the invasive front of the colon cancer, and it has been suggested that the inflammatory microenvironment around a tumor also induces EMT. Hence, it is likely that down-regulation of CDX2 expression in the invasive front in CRC contributes to enhanced tumorigenicity by regulating genes associated with the WNT/β-catenin pathway. Aim: To determine the role of TNFα in the regulation of CDX2 expression in CRC and its influence onWNT/β-catenin signaling. Methods: Carcinoma specimens were obtained from patients undergoing surgical resection of the rectum. Ten cases with tumor cell buddings were selected, and the expression patterns of TNFα and CDX2 at the invasive front were evaluated on immunostained slides. The mechanisms behind TNF-α-mediated down-regulation of CDX2 were investigated in vitro by selective inhibitors, and the impact of TNF-α on APC, AXIN2 and GSK3β expression were analyzed by quantitative real-time PCR (qPCR) in Caco-2 cells. Subsequently, in vivo CDX2-DNA interactions to APC, AXIN2 and GSK3β gene regulatory elements were investigated by chromatin immunoprecipitation in relation to the TNF-α status (presence vs. absence). Results: Immunohistochemical staining showed reduced CDX2 positive-cells in tumor buddings in areas with TNF-α expression in the surrounding inflammatory cells. TNF-α treatment showed a dosedependent decrease of CDX2 mRNA and protein expression dependent on p38 and NFκB, but not on JNK and ERK signaling pathways. Down-regulation of CDX2 leads to significantly decreased levels of APC (p,0.05), AXIN2 (p,0.01), and GSK3β (p,0.05) mRNA. In line with these results, TNF-α treatment impaired the ability of CDX2 to interact and activate the expression of APC (p,0.05), AXIN2 (p,0.01), and GSK3β (p,0.05). Conclusions: This study suggests that TNF-α has a tumor-promoting effect on CRC by influencing the activity of WNT signaling through down-regulation of CDX2 expression. These findings provide a novel insight into the molecular regulation of genes in the β-catenin degradation complex in response to the pro-inflammatory cytokine TNFα in cancer cells.


Internal Medicine | 2009

Causal Relationships between Esophageal Squamous Cell Carcinoma and Nephrotic Syndrome

Takashi Muramoto; Kazuhiro Kaneko; Aki Kuroki; Kazuo Konishi; Hiroaki Ito; Atsushi Katagiri; Yutaro Kubota; Atsushi Ohtsu; Michio Imawari


Clinical Journal of Gastroenterology | 2011

Primary micropapillary carcinoma of the colon: a case report and literature review

Hiroyoshi Doi; Kazuo Konishi; Risa Omori; Tatsuro Yanagawa; Atsushi Katagiri; Toshiko Yamochi; Yuko Date; Yutaro Kubota; Takashi Muramoto; Yuichiro Yano; Yoshiya Kobayashi; Masayuki Tojo; Kenichi Konda; Masahiko Murakami; Nozomi Yoshikawa; Michio Imawari

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