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Dive into the research topics where Takahisa Yamasaki is active.

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Featured researches published by Takahisa Yamasaki.


British Journal of Cancer | 2014

IL-22 produced by cancer-associated fibroblasts promotes gastric cancer cell invasion via STAT3 and ERK signaling.

Hirokazu Fukui; Xinxing Zhang; Chao Sun; Ken Hara; Shojiro Kikuchi; Takahisa Yamasaki; Takashi Kondo; Toshihiko Tomita; Tadayuki Oshima; Jiro Watari; Johji Imura; Takahiro Fujimori; Mitsuru Sasako; Hiroto Miwa

Background:Interleukin-22 (IL-22) has been recently highlighted owing to its biological significance in the modulation of tissue responses during inflammation. However, the role of IL-22 in carcinogenesis has remained unclear. Here, we investigated the pathophysiological significance of IL-22 expression in gastric cancer tissues and examined the mechanism by which IL-22 promotes gastric cancer cell invasion.Methods:Human gastric cancer specimens were analysed by immunohistochemistry for expression of IL-22 and IL-22 receptor 1 (IL-22R1). The effects of IL-22-induced STAT3 and ERK signalling on invasive ability of gastric cancer cells were examined using a small-interfering RNA system and specific inhibitors. AGS cells were co-cultured with cancer-associated fibroblasts (CAFs) from human gastric cancer tissues and assessed by invasion assay.Results:Interleukin-22 and its receptor were expressed in α-smooth muscle actin-positive stromal cells and tumour cells at the invasive front of gastric cancer tissues, respectively. The expression of IL-22 and IL-22R1 was significantly related to lymphatic invasion. Interleukin-22 treatment promoted the invasive ability of gastric cancer cells through STAT3 and ERK activation. The invasive ability of gastric cancer cells was significantly enhanced by co-culture with IL-22-expressing CAFs.Conclusions:Interleukin-22 produced by CAFs promotes gastric cancer cell invasion via STAT3 and ERK signalling.


Journal of Gastroenterology and Hepatology | 2012

Prospective randomized controlled trial to compare the effects of omeprazole and famotidine in preventing delayed bleeding and promoting ulcer healing after endoscopic submucosal dissection.

Toshihiko Tomita; Yongmin Kim; Takahisa Yamasaki; Takuya Okugawa; Takashi Kondo; Fumihiko Toyoshima; Jun Sakurai; Junji Tanaka; Tsuyoshi Morita; Tadayuki Oshima; Hirokazu Fukui; Kazutoshi Hori; Jiro Watari; Takayuki Matsumoto; Hiroto Miwa

Background and Aims:  Proton pump inhibitors (PPIs) are generally used to prevent delayed bleeding after endoscopic submucosal dissection (ESD) and to heal the artificial ulcers. However, it remains controversial whether PPIs or histamine‐2 receptor antagonists (H2RAs) are more effective in preventing delayed bleeding after ESD. We prospectively compared the effects of omeprazole and famotidine in preventing delayed bleeding and promoting artificial ulcer healing after ESD.


Digestive Endoscopy | 2014

Do endoscopic features suggesting eosinophilic esophagitis represent histological eosinophilia

Kazutoshi Hori; Jiro Watari; Hirokazu Fukui; Junji Tanaka; Toshihiko Tomita; Jun Sakurai; Takashi Kondo; Tadayuki Oshima; Fumihiko Toyoshima; Takahisa Yamasaki; Takuya Okugawa; Hiroto Miwa

Esophageal linear furrows, corrugated rings, and/or white exudates are often seen in patients with eosinophilic esophagitis (EoE); however, whether these are specific to EoE remains unclear. Endoscopic surveillance of these features was conducted to determine whether these represent esophageal eosinophilia, which is essential for the diagnosis of EoE.


Journal of Neurogastroenterology and Motility | 2016

Prevalence and Self-recognition of Chronic Constipation: Results of an Internet Survey

Akio Tamura; Toshihiko Tomita; Tadayuki Oshima; Fumihiko Toyoshima; Takahisa Yamasaki; Takuya Okugawa; Takashi Kondo; Tomoaki Kono; Katsuyuki Tozawa; Hisatomo Ikehara; Yoshio Ohda; Hirokazu Fukui; Jiro Watari; Hiroto Miwa

Background/Aims Although chronic constipation is a common symptom, to date no international consensus has been reached regarding its definition. The aims of this study were (1) to investigate defecation habits and (2) to examine the prevalence of constipation using the Japanese Society of Internal Medicine (JSIM) and the Rome III criteria using an online survey. Methods An online questionnaire composed of items on the frequency, interval, form of defecation, the management, and self-recognition of constipation (reference standard of constipation) was created. A total of 5155 valid responses were received. In addition, constipation symptoms were evaluated through a survey using the JSIM and the Rome III criteria. Results In the internet survey, 28.4% of the respondents considered themselves to be constipated. Stratified by sex, significantly more females (37.5%) than males (19.1%) considered themselves to be constipated (P < 0.001). The prevalence of constipation among the respondents was 28.0% using the Rome III, but only 10.1% using the JSIM. The diagnostic accuracy was 73.2% for the Rome III and 78.1% for the JSIM, while the diagnostic specificity was 81.1% for the Rome III and 97.5% for the JSIM. However, the diagnostic sensitivities for both measures were low, at 52.2% and 29.2% for the Rome III and the JSIM, respectively. Conclusions The online survey developed for this study was able to provide clarification regarding defecation patterns. The results also suggest a discrepancy between the self-recognized prevalence of constipation in Japan and prevalence of constipation based on the JSIM criteria.


British Journal of Cancer | 2016

Effects of Helicobacter pylori eradication on the development of metachronous gastric cancer after endoscopic treatment: analysis of molecular alterations by a randomised controlled trial

Maki Kawanaka; Jiro Watari; Noriko Kamiya; Takahisa Yamasaki; Takashi Kondo; Fumihiko Toyoshima; Hisatomo Ikehara; Toshihiko Tomita; Tadayuki Oshima; Hirokazu Fukui; Takashi Daimon; Kiron M. Das; Hiroto Miwa

Background:Whether Helicobacter pylori eradication actually suppresses the development of metachronous gastric cancer (MGC) after endoscopic resection (ER) remains controversial. The aims of this study were to clarify (1) the molecular markers related to carcinogenesis in intestinal metaplasia (IM) by a cross-sectional study, and (2) the changes of those markers by an open-label, randomised controlled trial (RCT) of H. pylori treatment.Methods:First, we evaluated microsatellite instability (MSI), the methylation status at hMLH1, CDKN2A and APC genes, and immunoreactivity using the monoclonal antibody (mAb) Das-1 in IM in the background mucosa of 131 patients who underwent ER for gastric neoplasia and 22 chronic gastritis cases (control). Next, we performed an RCT to evaluate the changes of MSI between the H. pylori-eradicated (n=19) and non-eradicated patients (n=17) at 1 year among the H. pylori-positive patients.Results:Microsatellite instability and mAb Das-1 reactivity showed significantly higher incidences in both the H. pylori-positive and -negative patients compared with the control group, thus suggesting that MSI and mAb Das-1 reactivity are associated with gastric neoplasia (OR=5.06 for MSI; OR=2.51 for mAb Das-1 reactivity). The RCT showed that H. pylori eradication did not provide significant reversals of any molecular alterations including MSI (the primary end point) and other methylation statuses and mAb Das-1 reactivity (secondary end points).Conclusions:H. pylori eradication did not produce significant changes in the molecular alterations related to carcinogenesis, suggesting that H. pylori treatment may not prevent the development of MGC in background mucosa with IM.


Gastroenterology | 2016

773 A Double-Blind Placebo Controlled Study of Acotiamide Hydrochloride for Efficacy on Gastrointestinal Motility of Patients With Functional Dyspepsia

Kumiko Nakamura; Toshihiko Tomita; Tadayuki Oshima; Tomohiro Ogawa; Ken Hara; Takahisa Yamasaki; Takuya Okugawa; Takashi Kondo; Tomoaki Kono; Katsuyuki Tozawa; Yoshio Ohda; Hirokazu Fukui; Jiro Watari; Hiroto Miwa

Background Acotiamide is widely used to improve symptoms in patients with functional dyspepsia (FD) in multiple large-scale clinical studies, but there are few reports about the drug’s mechanism of action. The aim of this study was to assess the effects of acotiamide on gastric accommodation and gastric emptying, gastrointestinal symptoms, and health-related quality of life (HR-QOL) in a placebo-controlled study.


Journal of Gastroenterology and Hepatology | 2013

Use of scintigraphy to evaluate gastric accommodation and emptying: Comparison with barostat

Toshihiko Tomita; Takuya Okugawa; Takahisa Yamasaki; Takashi Kondo; Fumihiko Toyoshima; Jun Sakurai; Tadayuki Oshima; Hirokazu Fukui; Takashi Daimon; Jiro Watari; Toru Kashiwagi; Takayuki Matsumoto; Hiroto Miwa

Scintigraphy is a useful noninvasive technique for assessment of gastric motility, especially emptying, but there is little knowledge of use of the technique to assess gastric accommodation. Therefore, to clarify the usefulness of scintigraphy as a technique for assessing gastric accommodation, we compared scintigraphy with barostat, the gold standard modality.


Gastrointestinal Endoscopy | 2011

A case of Cronkhite-Canada syndrome complicated by McKittrick-Wheelock syndrome associated with advanced villous adenocarcinoma

Jiro Watari; Jun Sakurai; Tsuyoshi Morita; Takahisa Yamasaki; Takuya Okugawa; Fumihiko Toyoshima; Takashi Kondo; Junji Tanaka; Toshihiko Tomita; Yongmin Kim; Tadayuki Oshima; Hirokazu Fukui; Kazutoshi Hori; Junsuke Oku; Takayuki Matsumoto; Hiroto Miwa

F w Cronkhite-Canada syndrome (CCS) is a rare noninherited disease characterized by hyperplastic GI polyposis with various GI symptoms, alopecia, and onychodystrophy.1 Although the etiology remains unclear, a significant umber of CCS patients with GI malignancy, especially olorectal adenoma and/or cancer, have been reported.2,3 McKittrick-Wheelock syndrome (MWS) is an infrequent disorder that has the clinical features of depletion syndrome characterized by dehydration, watery diarrhea, and various symptoms caused by hyponatremia and hypokalemia4 as well as CCS. The most frequently reported leions causing MWS are villous adenomas situated primarly in the rectum and sigmoid colon.4,5 We report an extremely rare case of a patient with CCS complicated by MWS, presumably caused by a large villous adenocarcinoma of the rectum.


Journal of Neurogastroenterology and Motility | 2017

Prevalence of Gastric Motility Disorders in Patients with Functional Dyspepsia

Haruki Asano; Toshihiko Tomita; Kumiko Nakamura; Takahisa Yamasaki; Takuya Okugawa; Takashi Kondo; Tomoaki Kono; Katsuyuki Tozawa; Yoshio Ohda; Tadayuki Oshima; Hirokazu Fukui; Kazuhito Fukushima; Shozo Hirota; Jiro Watari; Hiroto Miwa

Background/Aims Gastric motility abnormalities have been considered to be pathophysiological features of functional dyspepsia (FD) that are closely related to dyspepsia symptoms, especially postprandial distress syndrome (PDS). The aims of this study are to (1) investigate the prevalence of gastric motility disorders and (2) evaluate the association between gastric motility abnormalities and dyspeptic symptoms using gastric scintigraphy in the PDS type of FD. Methods Forty healthy subjects and 94 PDS type FD patients were enrolled in the study. The volunteers and patients ingested a radiolabeled (technetium-99m) solid test meal, and scintigraphic images were recorded. Gastric accommodation and emptying were assessed by scintigraphic imaging. The patients’ dyspeptic symptoms were also explored using self-completed symptom questionnaires with 10 variables (4 scales, 0–3 points) at the same time. Results In 94 Japanese FD patients, the prevalence of impaired gastric accommodation and delayed emptying were 14.9% (14/94) and 10.6% (10/94), respectively. Gastric motility abnormalities were seen in 25.5% (24/94) of FD patients. There was no association between gastric motility abnormalities and dyspeptic symptoms. Conclusions Gastric motility abnormalities were seen in 25.5% of Japanese PDS type FD patients. However, there was no association between gastric motility abnormalities and dyspeptic symptoms on gastric scintigraphy.


Journal of Neurogastroenterology and Motility | 2016

Prevalence of Irritable Bowel Syndrome-like Symptoms in Japanese Patients with Inactive Inflammatory Bowel Disease.

Toshihiko Tomita; Yu Kato; Mayu Takimoto; Takahisa Yamasaki; Takashi Kondo; Tomoaki Kono; Katsuyuki Tozawa; Yoko Yokoyama; Hisatomo Ikehara; Yoshio Ohda; Tadayuki Oshima; Hirokazu Fukui; Shigemi Tanaka; Masayuki Shima; Jiro Watari; Hiroto Miwa

Background/Aims Few studies are available that have investigated the risk factors for overlapping irritable bowel syndrome (IBS)-like symptoms in patients with inactive inflammatory bowel disease (IBD). The present study has 3 objectives: (1) to assess the prevalence of IBS-like symptoms in Japanese patients with inactive IBD using Rome III criteria, (2) to examine the relationship of IBS-like symptoms to health related quality of life (HR-QOL), and (3) to investigate associations for developing IBS-like symptoms in patients with inactive IBD. Methods IBS-like symptoms were evaluated using the Rome III questionnaire for functional gastrointestinal disorders. HR-QOL and hospital anxiety and depression scale were evaluated. Results IBS-like symptoms were found in 17.5% (7/40) of patients with inactive ulcerative colitis, 27.1% (29/107) of patients with inactive Crohn’s disease (CD), and 5.3% (23/438) of healthy control subjects. The QOL level was significantly lower and anxiety score was significantly higher in inactive CD patients with IBS-like symptoms than in those without such symptoms (P = 0.003, P = 0.009). Use of anti-anxiety drugs was associated with the presence of IBS symptoms (P = 0.045). HR-QOL score was lower and anxiety score was higher in patients with inactive ulcerative colitis, but the difference was not statistically significant. Conclusions The prevalence of IBS-like symptoms in inactive IBD patients was significantly higher than in healthy controls. Inactive CD patients with IBS-like symptoms has low QOL and anxiety; suggesting that anxiety may be associated with symptom development in such patients.

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Hiroto Miwa

Hyogo College of Medicine

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Tadayuki Oshima

Hyogo College of Medicine

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Jiro Watari

Hyogo College of Medicine

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Hirokazu Fukui

Hyogo College of Medicine

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Takashi Kondo

Hyogo College of Medicine

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Takuya Okugawa

Hyogo College of Medicine

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