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Dive into the research topics where Yuji Shimada is active.

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Featured researches published by Yuji Shimada.


Journal of Gastroenterology and Hepatology | 2010

Observational comparative trial of the efficacy of proton pump inhibitors versus histamine‐2 receptor antagonists for uninvestigated dyspepsia

Akihito Nagahara; Daisuke Asaoka; Mariko Hojo; Masako Oguro; Yuji Shimada; Dai Ishikawa; Taro Osada; Masato Kawabe; Takashi Yoshizawa; Michiro Otaka; Sumio Watanabe

Background and Aims:  It is still controversial which drugs, proton pump inhibitors (PPI) or histamine‐2 receptor antagonists (H2RA), are more effective for dyspepsia in the Japanese population.


Gastroenterology Research and Practice | 2014

The Relationship between H. pylori Infection and Osteoporosis in Japan

Daisuke Asaoka; Akihito Nagahara; Mariko Hojo; Hitoshi Sasaki; Yuji Shimada; Takashi Yoshizawa; Taro Osada; Sumio Watanabe

Background and Objective. H. pylori infection causes a chronic inflammation in the gastric mucosa. However, this local inflammation may result in extra-digestive conditions. Our aim is to investigate the relationship between H. pylori infection and osteoporosis in Japan. Methods. This cross-sectional study was conducted among outpatients at the Juntendo University Hospital between 2008 and 2014. Participants for patient profile, H. pylori infection status, comorbidity, internal medical therapies, lumbar dual-energy X-ray absorptiometry (DXA), and bone turnover marker were collected and upper gastrointestinal endoscopy for reflux esophagitis, hiatal hernia, peptic ulcer disease (PUD), and endoscopic gastric mucosal atrophy (EGA) was performed. The diagnosis of osteoporosis was performed in accordance with the Japanese criteria. We investigated risk factors of osteoporosis. Results. Of the eligible 200 study subjects, 41 cases were of osteoporosis. Bivariate analysis showed that age, being female, BMI, alcohol, smoking, H. pylori, bone-specific ALP, PUD, and EGA were related to osteoporosis. Multivariate analysis showed that age (OR 1.13; 95%CI 1.07–1.20), being female (OR 4.77; 95%CI 1.78–12.77), BMI (OR 0.79; 95%CI 0.68–0.92), H. pylori (OR 5.33; 95%CI 1.73–16.42), and PUD (OR 4.98; 95%CI 1.51–16.45) were related to osteoporosis. Conclusions. H. pylori infection may be a risk factor of osteoporosis in Japan.


Life Sciences | 2009

Target molecules of molecular chaperone (HSP70 family) in injured gastric mucosa in vivo

Michiro Otaka; Masaru Odashima; Yuko Izumi; Akihito Nagahara; Taro Osada; Naoto Sakamoto; Makiko Takada; Taiji Takahashi; Yuji Shimada; Kumiko Tamaki; Daisuke Asaoka; Hideaki Itoh; Sumio Watanabe

AIMS Several recent studies, including ours, have indicated the importance of heat shock proteins (HSPs) in cytoprotection against cytotoxic agents and environmental stresses mediated by the chaperone function of HSPs (molecular chaperones). However, the target molecule that is recognized by HSPs in damaged cells currently remains unknown. As HSPs rapidly recognize and bind to degenerated protein in cells, target molecules of HSPs might be key molecules for the initiation and pathogenesis of cellular damage. In the present study, gastric mucosal proteins that specifically bind to the HSP70 family (HSC70) were analyzed using HSC70-affinity chromatography. MAIN METHODS The gastric mucosa was removed from Sprague-Dawley rats after exposure to water immersion-stress for 0, 1, 3 or 5 h. Soluble fractions of each gastric mucosa were applied to the HSC70-affinity column separately. After washing off non-specific binding proteins, specific binding proteins were eluted by ATP-containing buffer. Binding proteins were analyzed by SDS-polyacrylamide gel electrophoresis. In addition, the amino acid sequence of purified proteins was also analyzed. KEY FINDINGS Specific HSC70-binding proteins with a molecular weight of 200-kDa and 45-kDa were eluted from an affinity column when gastric mucosal homogenate of 1-h stress exposure was applied. The amino acid sequencing showed that these binding proteins were cytoskeletal myosin (heavy chain) and actin, respectively. SIGNIFICANCE During the pathogenesis of stress-induced gastric mucosal damage, structurally degenerated cytoskeletal myosin (heavy chain) and actin may be key or initiation molecules which structural changes were firstly recognized by molecular chaperone.


Therapeutics and Clinical Risk Management | 2015

Risk factors for osteoporosis in Japan: is it associated with Helicobacter pylori ?

Daisuke Asaoka; Akihito Nagahara; Yuji Shimada; Kenshi Matsumoto; Hiroya Ueyama; Kohei Matsumoto; Yuta Nakagawa; Tsutomu Takeda; Ippei Tanaka; Hitoshi Sasaki; Taro Osada; Mariko Hojo; Sumio Watanabe

Background A number of diseases and drugs may influence bone mineral density; however, there are few reports concerning the relationship between lifestyle-related diseases and osteoporosis in Japan as determined by multivariate analysis. The aim of this study was to investigate the risk factors for osteoporosis and whether infection by or eradication of Helicobacter pylori is associated with osteoporosis. Methods Between February 2008 and November 2014, using a cross-sectional study design, we investigated patient profile (age, sex, BMI, alcohol, smoking), H. pylori infection status, comorbidities, internal medicine therapeutic agents (calcium channel blocker, HMG-CoA reductase inhibitors, proton pump inhibitor), serum parameters (Hb, calcium, γGTP), bone turn over markers (bone-specific alkaline phosphatase (BAP) and collagen type I cross-linked N telopeptide (NTX), findings on dual-energy x-ray absorptiometry (DEXA) and upper gastrointestinal endoscopy, and Frequency Scale for the Symptoms of GERD score in consecutive outpatients aged ≥50 years at our hospital. We divided the subjects into an osteoporosis group and a non-osteoporosis group and investigated risk factors for osteoporosis between the two groups by bivariate and multivariate analyses. Results Of the 255 eligible study subjects, 43 (16.9%) had osteoporosis. Bivariate analysis showed that advanced age, female sex, lower body mass index, lower cumulative alcohol intake, lower Brinkman index, H. pylori positivity, lower hemoglobin, bone-specific alkaline phosphatase, lower prevalence of hiatal hernia, and endoscopic gastric mucosal atrophy were related to osteoporosis. Multivariate analysis showed that advanced age (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.07–1.19, P<0.001), female sex (OR 6.27, 95% CI 2.26–17.39, P<0.001), low BMI (OR 0.82, 95% CI 0.72–0.94, P=0.005), H. pylori positivity (OR 3.00, 95% CI 1.31–6.88, P=0.009), and BAP (OR 1.07, 95% CI 1.01–1.14, P=0.035) were related to osteoporosis. Conclusion Advanced age, low BMI, BAP, and H. pylori positivity were risk factors for osteoporosis; however, the success of H. pylori eradication was not a risk factor for osteoporosis in Japan.


Life Sciences | 2009

Specific induction of a 72-kDa heat shock protein protects esophageal mucosa from reflux esophagitis

Yuko Izumi; Michiro Otaka; Taiji Takahashi; Makiko Takada; Yuji Shimada; Daisuke Asaoka; Akihito Nagahara; Hideaki Itoh; Sumio Watanabe

AIMS The aim of this study is to investigate the expression and cytoprotective function of a 72-kDa heat shock protein (HSP72) using a reflux esophagitis model in rats. MAIN METHODS Expression of HSP60, HSP72, and HSP90 in rat esophageal mucosa was evaluated by Western blot analysis before and after hyperthermia (42.5 degrees C, 20 min). Rats received the operation to produce reflux esophagitis with or without pretreatment with hyperthermia to induce HSPs. The esophageal mucosal damage was evaluated 12 h after the operation. KEY FINDINGS Expression of HSP72 was significantly increased by hyperthermia in rat esophageal mucosa. Reflux esophagitis was dramatically prevented when HSP72 was preinduced by hyperthermia. Furthermore, activation of TNF-alpha and IL-1beta in esophageal mucosa was also suppressed. SIGNIFICANCE These results suggested that hyperthermia protects the esophageal mucosa in reflux esophagitis model by inducing HSP72 and suppressing proinflammatory cytokine activation. These findings might suggest that HSP-inducing therapy could be a novel and unique therapy for reflux esophagitis.


Biomedical Reports | 2017

Efficacy of a potassium‑competitive acid blocker for improving symptoms in patients with reflux esophagitis, non‑erosive reflux disease, and functional dyspepsia

Daisuke Asaoka; Akihito Nagahara; Mariko Hojo; Kenshi Matsumoto; Hiroya Ueyama; Kohei Matsumoto; Kentaro Izumi; Tsutomu Takeda; Hiroyuki Komori; Yoichi Akazawa; Yuji Shimada; Taro Osada; Sumio Watanabe

The aim of the present study was to investigate the efficacy of a potassium-competitive acid blocker (PCAB) named vonoprazan (VPZ) for improving symptoms in patients with reflux esophagitis (RE), non-erosive reflux disease (NERD), and functional dyspepsia (FD). A hospital-based, retrospective study of outpatients in our department (Department of Gastroenterology, University of Juntendo, Tokyo, Japan) between March 2015 and August 2016 was performed. The patients who were experiencing heartburn, acid regurgitation, gastric pain, and/or a heavy feeling in the stomach of at least moderate severity at baseline were treated with 20 mg VPZ once daily for 4 weeks. The patients completed the global overall symptom (GOS) scale to determine their symptom severity at baseline and after the 4 week treatment period. The proportions of patients with RE, NERD, and FD achieving improvement of their symptoms, defined as a GOS scale score of 1 (‘no problem’) or 2 (‘minimal problem’), were evaluated. During 4 weeks of VPZ therapy, changes in the gastroesophageal reflux disease (GERD) score, which was defined as the total points for heartburn and acid regurgitation on the GOS scale in patients with RE and NERD, and in the FD score, which was defined as the total points for gastric pain and a heavy feeling in the stomach on the GOS scale in patients with FD, were also evaluated. A total of 88 eligible cases were included in the present study, comprising 20 patients with RE, 25 patients with NERD, and 43 patients with FD. The rates of symptomatic improvement in patients with RE, NERD, and FD were 75.0, 60.0, and 48.8%, respectively. For the patients who were first administered VPZ, the rates of symptomatic improvement were 90.9, 66.7, and 58.8% in patients with RE, NERD, and FD, respectively. For those patients who were resistant to 8 weeks of proton pump inhibitor therapy, the rates of symptomatic improvement were 55.6, 53.8, and 42.3% in patients with RE, NERD, and FD, respectively. The GERD score in patients with RE and NERD, and the FD score in FD patients, were decreased after 4 weeks of VPZ therapy (P<0.01). In patients with RE, NERD and FD, the possibility that PCAB may be used as a novel therapeutic drug was suggested. However, the number of study subjects was small; therefore, further, larger and prospective studies are required.


Therapeutics and Clinical Risk Management | 2016

Association of medications for lifestyle-related diseases with reflux esophagitis.

Daisuke Asaoka; Akihito Nagahara; Mariko Hojo; Kenshi Matsumoto; Hiroya Ueyama; Kohei Matsumoto; Kentaro Izumi; Tsutomu Takeda; Hiroyuki Komori; Yoichi Akazawa; Yuji Shimada; Taro Osada; Sumio Watanabe

Background Because of a change in lifestyle, especially adoption of westernized eating habits, lifestyle-related diseases have become increasingly prevalent. The aim of this study was to investigate the association of medications for lifestyle-related diseases with reflux esophagitis (RE). Methods We conducted a hospital-based, cross-sectional retrospective study of consecutive outpatients who received an upper gastrointestinal endoscopy in our department from February 2008 to November 2014, which was performed by one specialist who was a member of the Japan Gastroenterological Endoscopy Society. We investigated the patient profile, Helicobacter pylori (H. pylori) infection status, medications for lifestyle-related diseases (including calcium channel blockers, statins, and bisphosphonates), and upper gastrointestinal endoscopic findings (RE, hiatal hernia, Barrett’s mucosa, and endoscopic gastric mucosal atrophy [EGA]). Patients with gastrectomy, peptic ulcer disease, gastric or esophageal malignant disease, and those who used proton pump inhibitors or histamine-2 receptor antagonists were excluded. We divided the subjects into a group without RE (RE(−)) and a RE (RE(+)) group as judged by endoscopy, and investigated the risk factors for RE. Results Of 1,744 consecutive cases, 590 cases (300 males and 290 females; mean age 60.5±13.2 years) were eligible. RE(−) and RE(+) cases numbered 507 and 83, respectively. Bivariate analysis showed significant positive associations of RE with male sex, body mass index (BMI), calcium channel blockers, Barrett’s mucosa, hiatal hernia and negative associations of RE with H. pylori positivity, EGA. Multivariate analysis showed significant positive associations of RE with BMI (odds ratio [OR]: 1.20, 95% confidence interval [95% CI]: 1.10–1.29), use of calcium channel blockers (OR: 2.12, 95% CI: 1.16–3.87), Barrett’s mucosa (OR: 2.97, 95% CI: 01.64–5.38), hiatal hernia (OR: 3.13, 95% CI: 1.79–5.47) and negative associations of RE with H. pylori positivity (OR: 0.20, 95% CI: 0.07–0.57), use of statins (OR: 0.42, 95% CI: 0.18–0.96), and EGA (OR: 0.83, 95% CI: 0.70–0.98). Conclusion Calcium channel blockers were positively associated with RE and statins were negatively associated with RE, while bisphosphonates were not associated with RE.


International Journal of Molecular Sciences | 2016

Prediction of Hepatocellular Carcinoma Development after Hepatitis C Virus Eradication Using Serum Wisteria floribunda Agglutinin-Positive Mac-2-Binding Protein

Shunsuke Sato; Takuya Genda; Takafumi Ichida; Nozomi Amano; Sho Sato; Ayato Murata; Hironori Tsuzura; Yutaka Narita; Yoshio Kanemitsu; Katsuharu Hirano; Yuji Shimada; Katsuyori Iijima; Ryo Wada; Akihito Nagahara; Sumio Watanabe

We aimed to clarify the association between a novel serum fibrosis marker, Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+-M2BP), and hepatocellular carcinoma (HCC) development in 355 patients with chronic hepatitis C who achieved sustained virologic response (SVR) through interferon-based antiviral therapy. Pretreatment serum WFA+-M2BP levels were quantified and the hazard ratios (HRs) for HCC development were retrospectively analyzed by Cox proportional hazard analysis. During the median follow-up time of 2.9 years, 12 patients developed HCC. Multivariate analysis demonstrated that high serum WFA+-M2BP (≥2.80 cut off index (COI), HR = 15.20, p = 0.013) and high fibrosis-4 (FIB-4) index (≥3.7, HR = 5.62, p = 0.034) were independent risk factors for HCC development. The three- and five-year cumulative incidence of HCC in patients with low WFA+-M2BP were 0.4% and 0.4%, respectively, whereas those of patients with high WFA+-M2BP were 7.7% and 17.6%, respectively (p < 0.001). In addition, combination of serum WFA+-M2BP and FIB-4 indices successfully stratified the risk of HCC: the five-year cumulative incidences of HCC were 26.9%, 6.8%, and 0.0% in patients with both, either, and none of these risk factors, respectively (p < 0.001). In conclusion, pretreatment serum WFA+-M2BP level is a useful predictor for HCC development after achieving SVR.


Gastroenterology Research and Practice | 2015

Upper Gastrointestinal Mucosal Injury and Symptoms in Elderly Low-Dose Aspirin Users

Yuji Shimada; Akihito Nagahara; Mariko Hojo; Daisuke Asaoka; Hitoshi Sasaki; Hiroya Ueyama; Kenshi Matsumoto; Sumio Watanabe

Background. We investigated the prevalence, symptoms, and QOL impact of esophageal (EI), gastric (GI), and duodenal mucosal injury (DI) individually between low-dose aspirin (LDA) users and nonusers to reveal the clinical features of LDA-related mucosal injury. Methods. Data were extracted from the records of subjects who underwent upper gastrointestinal endoscopy at our department between April 2008 and December 2013. Responses from 3162 elderly patients on Frequency Scale for Symptoms of GERD (FSSG) and SF-8 QOL questionnaires (SF-8) were analyzed. FSSG items were classified into total score (TS), reflux score (RS), and dyspepsia score (DS). The SF-8 questionnaire consisted of the physical component summary (PCS) and mental component summary (MCS). Results. Prevalence among LDA users and nonusers, respectively, was 9.6% and 10.0% (P = 0.83) for EI, 35.9% and 27.5% (P = 0.0027) for GI, 3.3% and 3.4% (P = 0.84) for DI, and 8.2% and 5.2% (P = 0.036) for mucosal injury in 2 or more organs. LDA users diagnosed with EI had significantly lower PCS, LDA users diagnosed with GI had significantly lower DS, and LDA users diagnosed with DI had significantly lower RS and significantly lower MCS. Conclusion. These results provide important clinical information indicating that symptom-based management is not appropriate in LDA users regarding upper gastrointestinal mucosal injury.


Hepatology Research | 2017

Aldo-keto reductase family 1 member B10 is associated with hepatitis B virus-related hepatocellular carcinoma risk

Masashi Mori; Takuya Genda; Takafumi Ichida; Ayato Murata; Masato Kamei; Hironori Tsuzura; Shunsuke Sato; Yutaka Narita; Yoshio Kanemitsu; Sachiko Ishikawa; Tetsu Kikuchi; Yuji Shimada; Katsuharu Hirano; Katsuyori Iijima; Ken Sugimoto; Ryo Wada; Akihito Nagahara; Sumio Watanabe

Recent reports have indicated that aldo‐keto reductase family 1 member B10 (AKR1B10), a cancer‐related oxidoreductase, was upregulated in some chronic liver diseases. However, few studies have reported AKR1B10 expression in chronic hepatitis B virus (HBV)‐infected patients. The aim of the present study was to analyze AKR1B10 expression and its relevance on hepatocellular carcinoma (HCC) development in patients with chronic HBV infection.

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