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Dive into the research topics where Yasuaki Nagami is active.

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Featured researches published by Yasuaki Nagami.


Digestive and Liver Disease | 2013

Risk factors for severe nonsteroidal anti-inflammatory drug-induced small intestinal damage

Toshio Watanabe; Tetsuya Tanigawa; Yuji Nadatani; Yasuaki Nagami; Satoshi Sugimori; Hirotoshi Okazaki; Hirokazu Yamagami; Kenji Watanabe; Kazunari Tominaga; Yasuhiro Fujiwara; Tatsuya Koike; Tetsuo Arakawa

BACKGROUND Few studies have assessed the risk factors associated with nonsteroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal damage. AIMS To evaluate the risk factors for NSAID-induced enteropathy in patients with rheumatoid arthritis. METHODS A cross-sectional study using capsule endoscopy was conducted. A total of 113 patients who took NSAIDs for over 3 months underwent capsule endoscopies. Endoscopic findings were scored as (0) normal, (1) red spots, (2) 1-4 erosions, (3) >4 erosions, or (4) large erosions/ulcers. Initial scores were grouped into 3 categories: No damage (0-1), mild damage (2), and severe damage (3-4), and the potential risk factors for damage development were assessed. RESULTS Five patients were excluded because of incomplete visualization of the entire small intestine. Fifty-two (47.2%) and 27 (25%) patients had no damage and mild damage, respectively, while the remaining 30 patients (27.8%) had severe damage and significantly decreased hemoglobin levels. In a multivariate logistic regression analysis, ages of 65 years or more (odds ratio [OR], 4.16; 95% confidence interval [CI], 1.51-11.47), proton pump inhibitor usage (OR, 5.22; 95% CI, 1.36-20.11), and histamine H2 receptor antagonist usage (OR, 3.95; 95% CI, 1.28-12.25) were independent risk factors for severe damage. CONCLUSIONS Elderly patients and acid suppressant users are more likely to develop severe NSAID-induced enteropathy.


The American Journal of Gastroenterology | 2014

Usefulness of Non-Magnifying Narrow-Band Imaging in Screening of Early Esophageal Squamous Cell Carcinoma: A Prospective Comparative Study Using Propensity Score Matching

Yasuaki Nagami; Kazunari Tominaga; Hirohisa Machida; Masami Nakatani; Natsuhiko Kameda; Satoshi Sugimori; Hirotoshi Okazaki; Tetsuya Tanigawa; Hirokazu Yamagami; Naoshi Kubo; Masatsugu Shiba; Kenji Watanabe; Toshio Watanabe; Hiroyoshi Iguchi; Yasuhiro Fujiwara; Masaichi Ohira; Kosei Hirakawa; Tetsuo Arakawa

OBJECTIVES:The usefulness of non-magnifying endoscopy with narrow-band imaging (NBI; NM-NBI) in the screening of early esophageal squamous cell carcinoma (SCC) and high-grade intraepithelial neoplasia (HGIN) remains unclear. Here, we aimed to compare NM-NBI and chromoendoscopy with iodine staining (CE-Iodine) in terms of the diagnostic performance, and to evaluate the usefulness of NM-NBI in detecting early esophageal SCC.METHODS:We prospectively enrolled 202 consecutive patients (male/female=180/22; median age, 67 years) with high-risk factors for esophageal SCC. All patients received endoscopic examination with NM-NBI and CE-Iodine to screen for early esophageal SCC or HGIN. We conducted the examinations sequentially, and calculated the accuracy, sensitivity, and specificity through a per-lesion-based analysis. A propensity score matching analysis was performed to reduce the effects of selection bias, and we compared the respective outcomes according to NM-NBI and CE-Iodine after matching.RESULTS:The accuracy, sensitivity, and specificity of NM-NBI were 77.0, 88.3, and 75.2%, respectively, and those for unstained areas by CE-Iodine were 68.0, 94.2, and 64.0, respectively. The accuracy and specificity of NM-NBI were superior to those of CE-Iodine (P=0.03 and P=0.01, respectively). However, the sensitivity did not significantly differ between NM-NBI and CE-Iodine (P=0.67). The accuracy and specificity of NM-NBI before matching were superior to those of CE-Iodine after matching (P=0.04 and P=0.03).CONCLUSIONS:NM-NBI was useful and reliable for the diagnosis of esophageal SCC and can be a promising screening strategy for early esophageal SCC.


Gut | 2014

Anti-tumour necrosis factor agents reduce non-steroidal anti-inflammatory drug-induced small bowel injury in rheumatoid arthritis patients

Toshio Watanabe; Tetsuya Tanigawa; Masatsugu Shiba; Yuji Nadatani; Yasuaki Nagami; Satoshi Sugimori; Hirokazu Yamagami; Kenji Watanabe; Kazunari Tominaga; Yasuhiro Fujiwara; Tatsuya Koike; Tetsuo Arakawa

Objective The role of tumour necrosis factor α (TNFα) in the pathogenesis of non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal damage remains unclear. We evaluated the preventive effect of anti-TNF therapy against NSAID-induced enteropathy in rheumatoid arthritis (RA) patients. Design Capsule endoscopy was performed in 95 consecutive RA patients who received NSAID for more than 3 months, with or without anti-TNF therapy over a period of 3 months. The findings were scored from 0 to 4: 0, normal; 1, red spots; 2, one to four erosions; 3, more than four erosions; and 4, large erosions/ulcers. The relationship between the use of anti-TNF therapy and the risk of severe damage (scores 3 or 4) or the most severe damage (score 4) was assessed using multiple logistic regression analysis. Furthermore, a propensity score matching analysis was performed to reduce the effects of TNF selection bias. Results By stratifying the patients on the basis of anti-TNF therapy, we obtained crude OR of 0.23 for severe damage (95% CI 0.09 to 0.65) and 0.37 for the most severe damage (95% CI 0.16 to 0.86). This protective effect of anti-TNF therapy remained robust to adjustments for baseline characteristics, with the adjusted OR for severe damage and the most severe damage ranging from 0.23 to 0.26 and 0.06 to 0.41, respectively. Propensity score matching yielded similar results and showed the protective effects of anti-TNF therapy against severe and most severe damage. Conclusions Anti-TNF therapy may protect against NSAID-induced small intestinal damage in RA patients.


Endoscopy International Open | 2014

Clinical Efficacy of Endoscopic Submucosal Dissection for Adenocarcinomas of the Esophagogastric Junction.

Yasuaki Nagami; Hirohisa Machida; Masatsugu Shiba; Tomoko Obayashi; Masaki Ominami; Shusei Fukunaga; Satoshi Sugimori; Hirokazu Yamagami; Tetsuya Tanigawa; Kenji Watanabe; Toshio Watanabe; Kazunari Tominaga; Yasuhiro Fujiwara; Tetsuo Arakawa

Background and Study Aims There are a few reports about the efficacy of endoscopic submucosal dissection (ESD) for adenocarcinomas of the esophagogastric junction (EGJ). However, there is no detailed analysis that divides EGJ cancers into Barrett’s adenocarcinoma and gastric cardia adenocarcinoma. The aim of this study was to analyze the efficacy of ESD for EGJ cancers, comparing these two adenocarcinomas. Patients and Methods This study included 43 patients who underwent ESD for type II EGJ cancers between 2004 and 2011. Pathological examination of resected specimens confirmed 14 cases of Barrett’s adenocarcinoma and 29 cases of gastric cardia adenocarcinoma. Cutting margins on the oral side were placed 1 cm from the squamocolumnar junction, or 1 cm away from the slight elevation that is an endoscopic sign of subsquamous carcinoma extension. Clinical outcomes, prevalence and length of subsquamous carcinoma extension, and long-term outcomes were compared between these two types of adenocarcinoma. Results No significant differences in clinical outcomes were found between these two types of adenocarcinoma (en bloc, 100 % versus 100 %; complete, 100 % versus 89.7 %; curative, 85.7 % versus 75.9 %). No serious adverse events were encountered. The prevalence of subsquamous carcinoma extension was significantly higher in Barrett’s adenocarcinoma compared with gastric cardia adenocarcinoma. Local and distant recurrence were not observed in any cases with curative resection during the follow-up period (1.6 – 87.6 months). Conclusion ESD for EGJ cancers, including both Barrett’s adenocarcinoma and gastric cardia adenocarcinoma, was efficient and useful. ESD with a 1 cm safety margin may be acceptable for EGJ cancers.


Digestion | 2017

Microbiota Plays a Key Role in Non-Steroidal Anti-Inflammatory Drug-Induced Small Intestinal Damage.

Koji Otani; Tetsuya Tanigawa; Sunao Shimada; Yuji Nadatani; Yasuaki Nagami; Fumio Tanaka; Noriko Kamata; Hirokazu Yamagami; Masatsugu Shiba; Kazunari Tominaga; Yasuhiro Fujiwara; Tetsuo Arakawa

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) damage the small intestine by causing multiple erosions and ulcers. However, to date, no established therapies and prophylactic agents are available to treat such damages. We reviewed the role of intestinal microbiota in NSAID-induced intestinal damage and identified potential therapeutic candidates. Summary: The composition of the intestinal microbiota is an important factor in the pathophysiology of NSAID-induced small intestinal damage. Once mucosal barrier function is disrupted due to NSAID-induced prostaglandin deficiency and mitochondrial malfunction, lipopolysaccharide from luminal gram-negative bacteria and high mobility group box 1 from the injured epithelial cells activate toll-like receptor 4-signaling pathway and nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 inflammasome; this leads to the release of proinflammatory cytokines such as tumor necrosis factor-α and interleukin-1β. Proton pump inhibitors (PPIs) are often used for the prevention of NSAID-induced injuries to the upper gastrointestinal tract. However, several studies indicate that PPIs may induce dysbiosis, which may exacerbate the NSAID-induced small intestinal damage. Our recent research suggests that probiotics and rebamipide could be used to prevent NSAID-induced small intestinal damage by regulating the intestinal microbiota. Key Messages: Intestinal microbiota plays a key role in NSAID-induced small intestinal damage, and modulating the composition of the intestinal microbiota could be a new therapeutic strategy for treating this damage.


Digestive and Liver Disease | 2017

The five-year survival rate after endoscopic submucosal dissection for superficial esophageal squamous cell neoplasia

Yasuaki Nagami; Masaki Ominami; Masatsugu Shiba; Hiroaki Minamino; Shusei Fukunaga; Natsuhiko Kameda; Satoshi Sugimori; Hirohisa Machida; Tetsuya Tanigawa; Hirokazu Yamagami; Toshio Watanabe; Kazunari Tominaga; Yasuhiro Fujiwara; Tetsuo Arakawa

BACKGROUND Endoscopic submucosal dissection (ESD) is a widely accepted procedure for superficial esophageal squamous cell neoplasia (ESCN) because of a high complete resection rate. However, there were a few reports about the long-term outcomes of these patients due to short follow-up periods. AIMS We aimed to evaluate the 5-year survival after ESD for superficial ESCN. METHODS This was a retrospective cohort study performed at a single institution. Between 2006 and 2009, 94 patients with superficial ESCN underwent ESD. Eighty-three patients (93.3%) who had completed an extended period of observation of at least 5 years were enrolled. The main outcomes were the 5-year survival rates. The secondary outcomes were the cumulative incidence rate of metachronous ESCN, and the clinical outcomes. RESULTS The 5-year relative overall survival rate was 99.0%, whereas the cause specific survival rate was 100% during 72.9 months of median follow up period. Subgroup analysis showed that the 5year survival of patients with EP/LPM and MM/SM1 (submucosal invasion ≤200μm) were 100% and 89.0%, respectively. The cumulative incidence rate of metachronous ESCN at 5 years was 16.8%. CONCLUSION ESD for superficial ESCN is a curative treatment with a favorable 5-year survival rate.


Digestive and Liver Disease | 2014

The prevalence of adverse events associated with double-balloon enteroscopy from a single-centre dataset in Japan

Sayoko Nakayama; Kazunari Tominaga; Tomoko Obayashi; Junichi Okamoto; Hiroaki Minamino; Masaki Ominami; Shusei Fukunaga; Yasuaki Nagami; Satoshi Sugimori; Hirohisa Machida; Hirotoshi Okazaki; Mitsue Sogawa; Hirokazu Yamagami; Tetsuya Tanigawa; Kenji Watanabe; Toshio Watanabe; Yasuhiro Fujiwara; Tetsuo Arakawa

BACKGROUND There are few comprehensive reports detailing the prevalence of major adverse events associated with a double-balloon enteroscopy procedure. METHODS We retrospectively investigated the prevalence of major adverse events in 538 patients (262 males and 276 females; median age, 65 years; age range, 12-95 years) who underwent double-balloon enteroscopy at our Institution between April 2008 and October 2011. RESULTS Of the 17 adverse events recorded (3.2%), acute pancreatitis (n=5; 0.9%) occurred during both diagnostic (n=3) and therapeutic (n=2) anterograde double-balloon enteroscopy, and all of them were treated conservatively. For these cases, the average duration of the examination was 135 min, which was longer than for the other patients (97 min) (P=0.046). Intestinal bleeding (1.3%) was observed in 6 cases after endoscopic polypectomy and in 1 case following a biopsy procedure during a diagnostic double-balloon enteroscopy. The prevalence rates of intestinal perforation and other complications were 0.2% and 0.7%, respectively. CONCLUSIONS The rate of adverse events associated with double-balloon enteroscopy was high compared to that associated with conventional upper/lower gastrointestinal endoscopy (0.042%/0.078%). The occurrence of acute pancreatitis may be significantly dependent on the duration of double-balloon enteroscopy examination.


PLOS ONE | 2017

Neutrophil-to-Lymphocyte Ratio for Predicting Loss of Response to Infliximab in Ulcerative Colitis

Yu Nishida; Shuhei Hosomi; Hirokazu Yamagami; Tomomi Yukawa; Koji Otani; Yasuaki Nagami; Fumio Tanaka; Koichi Taira; Noriko Kamata; Tetsuya Tanigawa; Masatsugu Shiba; Kenji Watanabe; Kazunari Tominaga; Yasuhiro Fujiwara

Objectives Neutrophil-to-lymphocyte ratio (NLR) has been used to determine the outcome in malignancies and coronary heart disease. Some reports considered the value of NLR as a predictor of response to infliximab in patients with Crohn’s disease or rheumatoid arthritis; however, no similar studies have been reported for ulcerative colitis (UC). This study aimed to evaluate the clinical significance of the baseline NLR in patients with UC treated by infliximab. Materials and Methods Patients with moderate-to-severe active UC who received the first infliximab infusion in our hospital between 2010 and 2015, who showed clinical response during the induction period, were retrospectively evaluated for long-term outcomes and risk factors for loss of response (LOR) during infliximab maintenance therapy. Baseline inflammatory markers including NLR were measured within one week before the initiation of infliximab. Results Fifty-nine patients with moderate-to-severe active UC started treatment with infliximab and 37 patients (62.7%) experienced clinical response after induction therapy. Fourteen of 37 patients on maintenance therapy lost the response during follow-up. Baseline NLR of patients with LOR was significantly higher than in patients with sustained response. The NLR cut-off value of 4.488 was predictive of LOR, using receiver operating characteristic analysis (sensitivity: 78.6%, specificity: 78.3%). A univariate analysis revealed a significant relationship between relapse-free survival and the NLR (P = 0.018). Multivariate analysis indicated the NLR as an independent prognostic factor for LOR (hazard ratio = 3.86, 95% confidence interval: 1.20–12.4, P = 0.023). Conclusions Baseline NLR is a useful prognostic marker in patients with moderate-to-severe active UC treated with infliximab, and may contribute to appropriate use of infliximab.


Scientific Reports | 2016

NLRP3 inflammasome has a protective effect against oxazolone-induced colitis: a possible role in ulcerative colitis.

Shigehiro Itani; Yuji Nadatani; Naoki Sugimura; Sunao Shimada; Shogo Takeda; Koji Otani; Shuhei Hosomi; Yasuaki Nagami; Fumio Tanaka; Noriko Kamata; Hirokazu Yamagami; Tetsuya Tanigawa; Masatsugu Shiba; Kazunari Tominaga; Yasuhiro Fujiwara; Tetsuo Arakawa

The inflammasomes induce maturation of pro-interleukin-1β (IL-1β) and pro-IL-18. We investigated roles of the NLRP3 inflammasome in the pathogenesis of ulcerative colitis (UC). After induction of oxazolone-induced colitis, a mouse UC model, colonic tissues were assayed for inflammatory mediators. Histological studies were performed on inflamed colonic tissue from mice and UC patients. Histological severity of murine colitis peaked on day 1, accompanied by an increase in the expression of Th2 cytokines including IL-4 and IL-13. Oxazolone treatment stimulated maturation of pro-caspase-1 and pro-IL-1β, while it reduced IL-18 expression. Either exogenous IL-1β or IL-18 ameliorated the colitis with or without reduction in Th2 cytokine expression, respectively. Induction of colitis decreased MUC2 expression, which was reversed by administration of IL-18, but not IL-1β. Compared to wild-type mice, NLRP3−/− mice exhibited higher sensitivity to oxazolone treatment with enhancement of Th2 cytokine expression and reduction of mature IL-1β and IL-18 production; this phenotype was rescued by exogenous IL-1β or IL-18. Immunofluorescent studies revealed positive correlation of NLRP3 expression with disease severity in UC patients, and localization of the inflammasome-associated molecules in macrophages. The NLRP3 inflammasome-derived IL-1β and IL-18 may play a protective role against UC through different mechanisms.


Scientific Reports | 2016

Colchicine prevents NSAID-induced small intestinal injury by inhibiting activation of the NLRP3 inflammasome

Koji Otani; Sunao Shimada; Shogo Takeda; Shigehiro Itani; Akira Higashimori; Yuji Nadatani; Yasuaki Nagami; Fumio Tanaka; Noriko Kamata; Hirokazu Yamagami; Tetsuya Tanigawa; Masatsugu Shiba; Kazunari Tominaga; Yasuhiro Fujiwara; Tetsuo Arakawa

The inflammasome is a large, multiprotein complex that consists of a nucleotide-binding oligomerization domain-like receptor (NLR), an apoptosis-associated speck-like protein containing a caspase recruitment domain, and pro-caspase-1. Activation of the inflammasome results in cleavage of pro-caspase-1 into cleaved caspase-1, which promotes the processing of pro-interleukin (IL)-1β into mature IL-1β. We investigated the effects of colchicine on non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal injury and activation of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome. Colchicine treatment inhibited indomethacin-induced small intestinal injury by 86% (1 mg/kg) and 94% (3 mg/kg) as indicated by the lesion index 24 h after indomethacin administration. Colchicine inhibited the protein expression of cleaved caspase-1 and mature IL-1β, without affecting the mRNA expression of NLRP3 and IL-1β. Although treatment with recombinant IL-1β (0.1 μg/kg) did not change the severity of small intestinal damage, the preventive effects of colchicine were abolished by supplementation with the same dose of recombinant IL-1β. Indomethacin-induced small intestinal damage was reduced by 77%, as determined by the lesion index in NLRP3−/− mice, and colchicine treatment failed to inhibit small intestinal damage in NLRP3−/− mice. These results demonstrate that colchicine prevents NSAID-induced small intestinal injury by inhibiting activation of the NLRP3 inflammasome.

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