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Abstract Mesenchymal stem/stromal cells (MSCs) are distributed in various tissues and are used in clinical applications as a source of transplanted cells because of their easy harvestability. Although MSCs express numerous cell-surface antigens, single-cell analyses have revealed a highly heterogeneous cell population depending on the original tissue and donor conditions, including age and interindividual differences. This heterogeneity leads to differences in their functions, such as multipotency and immunomodulatory effects, making it challenging to effectively treat targeted diseases. The therapeutic efficacy of MSCs is controversial and depends on the implantation site. Thus, there is no established recipe for the transplantation of MSCs (including the type of disease, type of origin, method of cell culture, form of transplanted cells, and site of delivery). Our recent preclinical study identified appropriate MSCs and their suitable transplantation routes in a mouse model of inflammatory bowel disease (IBD). Three-dimensional (3D) cultures of MSCs have been demonstrated to enhance their properties and sustain engraftment at the lesion site. In this note, we explore the methods of MSC transplantation for treating IBDs, especially Crohn’s disease, from clinical trials published over the past decade. Given the functional changes in MSCs in 3D culture, we also investigate the clinical trials using 3D constructs of MSCs and explore suitable diseases that might benefit from this approach. Furthermore, we discuss the advantages of the prospective isolation of MSCs in terms of interindividual variability. This note highlights the need to define the method of MSC transplantation, including interindividual variability, the culture period, and the transplantation route.

Abstract Background The post-insertion clinical course of esophageal self-expandable metal stents (SEMS) in initially frail patients with esophageal carcinoma (EC) with dysphagia remains unclear. This study aimed to assess dysphagia improvement and evaluate prognosis in initially frail patients with advanced EC following SEMS insertion. Methods We retrospectively reviewed EC patients with EC who underwent esophageal SEMS insertion at our institution between January 2014 and March 2023. Inclusion criteria comprised Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≥ 3 or ECOG PS 2 for individuals aged ≥ 75 years and recommendation for best supportive care by a multidisciplinary team. Results Forty-six patients met the inclusion criteria. Among them, 37 patients (80.4%) were ≥ 75 years old, and 21 patients (45.7%) exhibited ECOG PS 3 or 4. Dysphagia score (DS) ≥ 3 was observed in 27 patients (58.7%). All esophageal SEMS insertions were successfully completed. Post-procedure, there were two fatal cases of aspiration pneumonia and one perforation incident. DS improved to ≤ 1 in 25 patients (54.3%), with multivariate analysis indicating DS 3–4 and Glasgow Prognostic Score (GPS) 1–2 as negative predictive factors. The median overall survival was 4.1 months (95% confidence interval 1.8–6.5). Conclusions Esophageal SEMS insertion effectively alleviated dysphagia in initially frail EC patients, yet prognosis remained poor, with occurrences of some fatal adverse events. Careful selection of candidates for esophageal SEMS insertions is crucial in this demographic, particularly considering the challenges in improving dysphagia for patients with DS 3–4 and GPS 1–2.

Background/Aims Mirikizumab is a p19-directed anti-interleukin-23 antibody with potential efficacy against ulcerative colitis (UC). We evaluated the efficacy and safety of mirikizumab in a Japanese subpopulation with moderately to severely active UC from the LUCENT-1 and LUCENT-2 studies. Methods LUCENT-1 and LUCENT-2 were phase 3, randomized, double-blind, placebo-controlled trials of mirikizumab therapy in adults with moderately to severely active UC. LUCENT-1 was a 12-week induction trial where patients were randomized 3:1 to receive intravenous mirikizumab 300 mg or placebo every 4 weeks (Q4W). Patients achieving a clinical response with mirikizumab following the induction study were re-randomized 2:1 to double-blind treatment with either mirikizumab 200 mg or placebo subcutaneously Q4W during the 40-week maintenance study. The primary outcomes were clinical remission at week 12 of LUCENT-1 and week 40 of LUCENT-2. Results A total of 137 patients enrolled in Japan were randomized to mirikizumab (n = 102) or placebo (n = 35). Compared with placebo, patients who received mirikizumab showed numerically higher clinical remission at week 12 of induction (32.4% [n = 33] vs. 2.9% [n = 1]) and at week 40 of maintenance (48.9% [n = 23] vs. 28.0% [n = 7]). A greater number of patients achieved key secondary endpoints in the mirikizumab group compared with placebo. The frequency of treatment-emergent adverse events was similar across mirikizumab and placebo groups. Efficacy and safety results observed in the Japanese subpopulation were generally consistent with those in the overall population. Conclusions Mirikizumab induction and maintenance treatments were effective in Japanese patients with moderately to severely active UC. No new safety concerns were identified.

Summary: In normal intestines, a fetal/regenerative/revival cell state can be induced upon inflammation. This plasticity in cell fate is also one of the current topics in human colorectal cancer (CRC). To dissect the underlying mechanisms, we generated human CRC organoids with naturally selected genetic mutation profiles and exposed them to two different conditions by modulating the extracellular matrix (ECM). Among tested mutation profiles, a fetal/regenerative/revival state was induced following YAP activation via a collagen type I-enriched microenvironment. Mechanistically, YAP transcription was promoted by activating AP-1 and TEAD-dependent transcription and suppressing intestinal lineage-determining transcription via mechanotransduction. The phenotypic conversion was also involved in chemoresistance, which could be potentially resolved by targeting the underlying YAP regulatory elements, a potential target of CRC treatment.

Background/Aims The safety and efficacy of filgotinib, a once-daily oral Janus kinase 1 preferential inhibitor, were evaluated in Japanese patients with ulcerative colitis (UC) in the phase 2b/3 SELECTION trial. Methods SELECTION (NCT02914522) was a randomized, placebo-controlled trial comprising 2 induction studies and a maintenance study. Adults with moderately to severely active UC were randomized in induction study A (biologic-naïve) or B (biologic-experienced) to receive filgotinib 200 mg, 100 mg, or placebo once daily for 11 weeks. Patients in clinical remission or Mayo Clinic score response at week 10 entered the 47-week maintenance study. Efficacy and safety outcomes were assessed in Japanese patients enrolled in Japan. Results Overall, 37 and 72 Japanese patients were enrolled in Japan in induction studies A and B, respectively, and 54 entered the maintenance study. Numerically higher proportions of filgotinib 200 mg-treated than placebo-treated patients achieved clinical remission in induction study A (4/15 [26.7%] vs. 0/6 [0%]) and the maintenance study (5/20 [25.0%] vs. 0/9 [0%]), but not induction study B (1/29 [3.4%] vs. 1/14 [7.1%]). Both doses were well tolerated, and no new safety signals were noted. Herpes zoster was reported in 1 filgotinib 200 mg-treated patient in each of induction study A (2.3%, 1/44) and the maintenance study (5.0%, 1/20). Conclusions These data, alongside those of the overall SELECTION population, suggest the potential of filgotinib 200 mg as a viable treatment option for Japanese patients with UC. Owing to small patient numbers, data should be interpreted cautiously.

Abstract Background and Aim The number of patients with ulcerative colitis (UC) has been increasing in Japan. To elucidate the risk factors for developing UC in Japan, a hospital‐based case–control study was conducted. This study examined the association between smoking/drinking habits and UC onset in detail. Methods Cases comprised 132 Japanese patients who had been newly diagnosed with UC between 2008 and 2014 at 38 collaborating hospitals in Japan, and controls comprised 167 patients without UC. Detailed data on smoking and drinking habits were collected using a self‐administered questionnaire. Results Ex‐smokers showed an increasing odds ratio (OR) for UC development compared with never smokers (OR 2.42, 95% confidence interval 1.24–4.72). The ORs of ex‐smokers were particularly high among subjects aged less than 40 years, subjects who had smoked more than 10 pack‐years, and subjects who were within 13 years of quitting smoking. Regarding drinking habits, ex‐drinkers also showed a more than twofold higher OR for UC compared to never drinkers. Ex‐drinkers 40 years or older, ex‐drinkers who had consumed more than 364 drink‐years, and subjects who were less than 6 years after quitting drinking showed increased ORs for UC. Conclusion These findings suggest the need for careful attention for UC onset among heavy smokers who quit smoking before 40 years of age and heavy drinkers who quit drinking at ≥40 years of age.

Abstract Background The emerging concepts of fetal-like reprogramming following tissue injury have been well recognized as an important cue for resolving regenerative mechanisms of intestinal epithelium during inflammation. We previously revealed that the remodeling of mesenchyme with collagen fibril induces YAP/TAZ-dependent fate conversion of intestinal/colonic epithelial cells covering the wound bed towards fetal-like progenitors. To fully elucidate the mechanisms underlying the link between extracellular matrix (ECM) remodeling of mesenchyme and fetal-like reprogramming of epithelial cells, it is critical to understand how collagen type I influence the phenotype of epithelial cells. In this study, we utilize collagen sphere, which is the epithelial organoids cultured in purified collagen type I, to understand the mechanisms of the inflammatory associated reprogramming. Resolving the entire landscape of regulatory networks of the collagen sphere is useful to dissect the reprogrammed signature of the intestinal epithelium. Methods We performed microarray, RNA-seq, and ATAC-seq analyses of the murine collagen sphere in comparison with Matrigel organoid and fetal enterosphere (FEnS). We subsequently cultured human colon epithelium in collagen type I and performed RNA-seq analysis. The enriched genes were validated by gene expression comparison between published gene sets and immunofluorescence in pathological specimens of ulcerative colitis (UC). Results The murine collagen sphere was confirmed to have inflammatory and regenerative signatures from RNA-seq analysis. ATAC-seq analysis confirmed that the YAP/TAZ-TEAD axis plays a central role in the induction of the distinctive signature. Among them, TAZ has implied its relevant role in the process of reprogramming and the ATAC-based motif analysis demonstrated not only Tead proteins, but also Fra1 and Runx2, which are highly enriched in the collagen sphere. Additionally, the human collagen sphere also showed a highly significant enrichment of both inflammatory and fetal-like signatures. Immunofluorescence staining confirmed that the representative genes in the human collagen sphere were highly expressed in the inflammatory region of ulcerative colitis. Conclusions Collagen type I showed a significant influence in the acquisition of the reprogrammed inflammatory signature in both mice and humans. Dissection of the cell fate conversion and its mechanisms shown in this study can enhance our understanding of how the epithelial signature of inflammation is influenced by the ECM niche.

Abstract Background Small intestinal stricture is a major cause for surgery in Crohn’s disease (CD). Endoscopic balloon dilation (EBD) is performed for small intestinal strictures to avoid surgery, often repeatedly. However, factors that are associated with prognosis after EBD of small intestinal strictures remain poorly investigated. Mucosal healing is the therapeutic target in CD. We aimed to investigate the impact of mucosal healing defined by the presence of ulcers at the small intestinal stricture site on the prognosis of EBD in CD patients. Methods We retrospectively included patients with CD who underwent initial EBD for endoscopically impassable small intestinal strictures from January 2012 to March 2020 at a single center. The association between presence of ulcer at the stricture site and surgery after EBD was examined by Cox proportional hazards model. Results Of the 98 patients included, 63 (64.3%) had ulcer at the stricture site. 20 (31.7%) of these patients underwent surgery for the stricture in due course, whereas 4 (11.4%) of the patients without ulcer of the stricture underwent surgery. In multivariate analysis, patients with ulcer of the stricture had a significantly higher risk for surgery than those without ulcer (hazard ratio 4.84; 95% confidence interval 1.58–14.79). Conclusion Mucosal healing at the stricture site indicated a favorable prognosis after EBD for small intestinal strictures in CD.

Inflammatory bowel disease (IBD), with its 2 subtypes, Crohn’s disease and ulcerative colitis, is a complex chronic condition. A precise definition of disease activity and appropriate drug management greatly improve the clinical course while minimizing the risk or cost. Artificial intelligence (AI) has been used in several medical diseases or situations. Herein, we provide an overview of AI for endoscopy in IBD. We discuss how AI can improve clinical practice and how some components have already begun to shape our knowledge. There may be a time when we can use AI in clinical practice. As AI systems contribute to the exact diagnosis and treatment of human disease, we should continue to learn best practices in health care in the field of IBD.

Background & Aims: Mucosal-associated invariant T (MAIT) cells are innate-like T cells restricted by major histocompatibility complex-related molecule 1 (MR1) and express a semi-invariant T cell receptor. Previously, we reported the activation status of circulating MAIT cells in patients with ulcerative colitis (UC) was associated with disease activity and that these cells had infiltrated the inflamed colonic mucosa. These findings suggest MAIT cells are involved in the pathogenesis of inflammatory bowel disease. We investigated the role of MAIT cells in the pathogenesis of colitis by using MR1−/− mice lacking MAIT cells and a synthetic antagonistic MR1 ligand. Methods: Oxazolone colitis was induced in MR1−/− mice (C57BL/6 background), their littermate wild-type controls, and C57BL/6 mice orally administered an antagonistic MR1 ligand, isobutyl 6-formyl pterin (i6-FP). Cytokine production of splenocytes and colonic lamina propria lymphocytes from mice receiving i6-FP was analyzed. Intestinal permeability was assessed in MR1−/− and i6-FP-treated mice and their controls. The effect of i6-FP on cytokine production by MAIT cells from patients with UC was assessed. Results: MR1 deficiency or i6-FP treatment reduced the severity of oxazolone colitis. i6-FP treatment reduced cytokine production in MAIT cells from mice and patients with UC. Although MR1 deficiency increased the intestinal permeability, i6-FP administration did not affect gut integrity in mice. Conclusions: These results indicate MAIT cells have a pathogenic role in colitis and suppression of MAIT cell activation might reduce the severity of colitis without affecting gut integrity. Thus, MAIT cells are potential therapeutic targets for inflammatory bowel disease including UC.

Abstract Background Intravenous corticosteroid is the mainstay for managing acute severe ulcerative colitis, but one-third of patients do not respond to intravenous corticosteroid. Tacrolimus, a salvage therapy before colectomy, is usually orally administered, though its bioavailability is low compared intravenous administration. The efficacy of intravenous tacrolimus has not been widely studied. Aim To determine the efficacy and safety of intravenous tacrolimus for the treatment of acute severe ulcerative colitis. Methods Eighty-seven hospitalized acute severe ulcerative colitis patients were enrolled for a prospective cohort study between 2009 and 2017. Sixty-five patients received intravenous tacrolimus and 22 received oral tacrolimus. The primary outcome was the achievement of clinical remission within 2 weeks. Relapse and colectomy incidence and adverse events were assessed at 24 weeks. Results Response rates of both treatments exceeded 50% but were not significantly different. The remission rate was higher in intravenous tacrolimus compared with oral tacrolimus. At 24 weeks, oral and intravenous tacrolimus showed similar relapse-free survival rates; however, colectomy-free survival rates were higher in intravenous tacrolimus compared with oral tacrolimus. Conclusions Patients receiving intravenous tacrolimus achieved superior remission and colectomy-free survival rates compared with patients receiving oral tacrolimus. Safety was similar between the two treatments.

Background/Aims A subgroup analysis was conducted in Japanese patients with moderate to severe ulcerative colitis (UC) enrolled in the phase 3 VISIBLE 1 study, which evaluated the safety and efficacy of a new vedolizumab subcutaneous (SC) formulation. Methods Eligible patients received open-label infusions of vedolizumab 300 mg intravenous (IV) at weeks 0 and 2 in the induction phase. Patients with clinical response by complete Mayo score at week 6 entered the double-blind maintenance phase and were randomized to vedolizumab 108 mg SC every 2 weeks, placebo, or vedolizumab 300 mg IV every 8 weeks. The primary endpoint was clinical remission (complete Mayo score ≤ 2 points; no individual subscore > 1 point) at week 52. Results Of 49 patients who entered the induction phase, 22 out of 49 patients (45%) had clinical response at week 6 and were randomized to vedolizumab 108 mg SC (n = 10), placebo (n = 10), or vedolizumab 300 mg IV (n = 2). At week 52, 4 out of 10 patients (40%) who received vedolizumab SC had clinical remission versus 2 out of 10 patients (20%) who received placebo (difference: 20% [95% confidence interval, –27.9 to 61.8]). Two patients (2/10, 20%) who received vedolizumab SC experienced an injection-site reaction versus none who received placebo. Conclusions Our results indicate that the efficacy of vedolizumab SC in a subgroup of Japanese patients with UC are similar with those in the overall VISIBLE 1 study population, and with those established with vedolizumab IV. The safety and tolerability of vedolizumab SC were generally similar to that established for vedolizumab IV. (ClinicalTrials.gov ID NCT02611830; EudraCT 2015-000480-14)

Background/Aims Crohn’s disease is a chronic disorder; therefore, it is essential to investigate long-term safety and efficacy of treatments. This study assessed the safety and effectiveness of adalimumab for up to 3 years in Japanese patients with Crohn’s disease in real-world settings. Methods This was a multicenter, single-cohort, observational study of patients with Crohn’s disease. Safety assessments included incidence of adverse drug reactions. Effectiveness assessments included clinical remission, mucosal healing, and Work Productivity and Activity Impairment (WPAI). Results The safety and effectiveness analysis populations comprised 389 and 310 patients, respectively. Mean (standard deviation) exposure to adalimumab in the safety analysis population was 793.4 (402.8) days, with a 58.1% retention rate. A total of 105 patients (27.0%) and 43 patients (11.1%) experienced adverse drug reactions and serious adverse drug reactions, respectively, with no patient reporting tuberculosis or hepatitis B. Infections and serious infections were reported in 37 patients (9.5%) and 17 patients (4.4%), respectively. Malignancy was reported as an adverse drug reaction in 2 patients (0.5%). Remission rate increased from 37.8% (98/259) at baseline to 73.9% (167/226) at week 4 and remained > 70% over 3 years. Proportion of patients without mucosal ulcerations increased from 2.7% (2/73) at baseline to 42.3% (11/26) between years > 2 to ≤ 3. WPAI improvement started at 4 weeks, with the overall work impairment score improving from 42.7 (n = 102) at baseline to 26.9 (n = 84) at 4 weeks. Conclusions Results from this study confirm the long-term safety and effectiveness of adalimumab treatment in Japanese patients with Crohn’s disease in the real-world setting.

Trifluridine/tipiracil (FTD/TPI) is an oral anticancer agent used as a third- or later-line treatment for patients with metastatic gastric cancer/gastroesophageal junction cancer (mGC/GEJC). The C-reactive protein-to-serum albumin ratio (CAR) is an inflammation-based prognostic marker in gastric cancer. This retrospective study evaluated CAR’s clinical significance as a prognostic factor in 64 patients with mGC/GEJC administered FTD/TPI as a third- or later-line therapy. Patients were categorized into high- and low-CAR groups based on pre-treatment blood data. This study evaluated associations between CAR and overall survival (OS), progression-free survival (PFS), clinicopathological features, treatment efficacy, and adverse events. The high-CAR group had significantly worse Eastern Cooperative Oncology Group performance status, a higher prevalence of patients administered with a single course of FTD/TPI, and a higher rate of patients not administered chemotherapy after FTD/TPI therapy than the low-CAR group. Median OS and PFS were significantly poorer in the high-CAR group than in the low-CAR group (113 vs. 399 days; p < 0.001 and 39 vs. 112 days; p < 0.001, respectively). In multivariate analysis, high CAR was an independent prognostic factor for OS and PFS. The overall response rate was not significantly different between the high- and low-CAR groups. Regarding adverse events, the high-CAR group had a significantly lower incidence of neutropenia and a higher incidence of fatigue than the low-CAR group. Therefore, CAR may be a potentially useful prognostic factor for patients with mGC/GEJC treated with FTD/TPI as third- or later-line chemotherapy.

Abstract Heterotopic gastric gland (HGG)‐originating early gastric cancer was endoscopically resected. We resected the HGG, widely marked the perimeter outside the submucosal tumor‐like area, injected from outside the markings into the submucosa, dissected the muscular layer, and used fine‐tip hood. HGG removal and ensuring negative horizontal and vertical margins are critical.

Introduction: Duodenal neuroendocrine tumors (DNETs) smaller than 1 cm in diameter, without invasion to the muscularis propria, have a low risk of metastasis. Therefore, DNETs are frequently resected endoscopically. However, among the various procedures, the best fit for DNET in terms of feasibility, effectiveness, and simplicity is unclear. Methods: Patients with DNET who underwent endoscopic submucosal resection using a ligation device (ESMR-L) at Kanagawa Cancer Center between May 2003 and December 2020 were studied retrospectively to evaluate clinical characteristics and short-term and long-term outcomes. Results: Eleven consecutive patients with 12 lesions were treated with 12 sessions of ESMR-L. Lesions were discovered in patients at a median age of 68 (range, 50–83) years. One patient had two lesions at the time of the initial ESMR-L session. Eleven of the 12 lesions (91.7%) existed in the duodenal bulb, of which 10 (83.3%) were in the anterior wall, and the remaining one (8.3%) existed in the descending part of the duodenum. The en bloc and R0 resection rates were 100% and 75%, respectively. The rates of bleeding and perforation were both 0%. Among the four patients who had non-curative resections, two patients underwent additional surgery after ESMR-L. One patient had a local remnant tumor, and the other had lymph node metastasis. In cases of local remnant tumors, the vertical margin was positive in the ESMR-L specimen. In that case, ligation by the O-ring was insufficient, retrospectively. All patients had no recurrence during the median follow-up period of 5.7 years. Discussion: ESMR-L was the best fit for DNET within the indications for endoscopic resection. It is a simple procedure that enables easy and complete resection of DNETs without complications.

Background & Aims: The reason why small intestinal cancer is rarer than colorectal cancer is not clear. We hypothesized that intraepithelial lymphocytes (IELs), which are enriched in the small intestine, are the closest immune cells to epithelial cells, exclude tumor cells via cell-to-cell contact. Methods: We developed DPE-green fluorescent protein (DPE-GFP) × adenomatous polyposis coli; multiple intestinal neoplasia (APCmin ) mice, which is a T-cell–reporter mouse with spontaneous intestinal tumors. We visualized the dynamics of IELs in the intestinal tumor microenvironment and the interaction between IELs and epithelial cells, and the roles of cell-to-cell contact in anti-intestinal tumor immunity using a novel in vivo live-imaging system and a novel in vitro co-culture system. Results: In the small intestinal tumor microenvironment, T-cell movement was restricted around blood vessels and the frequency of interaction between IELs and epithelial cells was reduced. Genetic deletion of CD103 decreased the frequency of interaction between IELs and epithelial cells, and increased the number of small intestinal tumors. In the co-culture system, wild-type IELs expanded and infiltrated to intestinal tumor organoids from APCmin mice and reduced the viability of them, which was cell-to-cell contact and CD103 dependent. Conclusions: The abundance of IELs in the small intestine may contribute to a low number of tumors, although this system may not work in the colon because of the sparseness of IELs. Strategies to increase the number of IELs in the colon or enhance cell-to-cell contact between IELs and epithelial cells may be effective for the prevention of intestinal tumors in patients with a high cancer risk.

Induction therapy with tumor necrosis factor-α (TNF-α) inhibitors is highly effective for the treatment of Crohn’s disease. However, there are primary nonresponders (PNR) of TNF-α inhibitors without clinical response during the induction period. In addition, there are partial responders (PR), who show some efficacy, but clinical remission is not achieved by induction therapy. To date, the definition and clinical management of PNR and PR have not been established. This report summarizes the opinions of 36 Japanese experts attending the Japan Round Table Discussion on IBD Meeting regarding how to determine PNR and PR of TNF-α inhibitors and how to manage these patients in clinical practice. PNR, who do not show any initial improvement of clinical symptoms and serum C-reactive protein (CRP) levels, require re-assessment of intestinal complications. PR can be determined either by clinical symptoms, serum CRP levels, or imaging results. PR need intensification of the treatment with TNF-α inhibitors either with or without optimization of immunomodulators. Optimization of initial TNF-α inhibitor therapy may improve long-term outcomes, but more evidence is required to improve the use of TNF-α inhibitors for the prevention and management of PNR and PR.

Inflammatory bowel disease (IBD) consists of two major idiopathic gastrointestinal diseases: ulcerative colitis and Crohn's disease. Although a significant advance has been achieved in the treatment of IBD, there remains a particular population of patients that are refractory to the conventional treatments, including the biologic agents. Studies have revealed the importance of “mucosal healing” in improving the prognosis of those difficult-to-treat patients, which indicates the proper and complete regeneration of the damaged intestinal tissue. In this regard, organoid-based regenerative medicine may have the potential to dramatically promote the achievement of mucosal healing in refractory IBD patients, and thereby improve their long-term prognosis as well. So far, studies have shown that hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) may have some beneficial effect on IBD patients through their transplantation or transfusion. Recent advance in stem cell biology has added intestinal stem cells (ISCs) as a new player in this field. It has been shown that ISCs can be grown in vitro as organoids and that those ex-vivo cultured organoids can be employed as donor cells for transplantation studies. Further studies using mice colitis models have shown that ex-vivo cultured organoids can engraft onto the colitic ulcers and reconstruct the crypt-villus structures. Such transplantation of organoids may not only facilitate the regeneration of the refractory ulcers that may persist in IBD patients but may also reduce the risk of developing colitis-associated cancers. Endoscopy-assisted transplantation of organoids may, therefore, become one of the alternative therapies for refractory IBD patients. Keywords: Intestinal stem cells, Organoids, Ulcerative colitis, Crohn's disease, Organoid medicine

Formation of intrahepatic bile ducts (IHBDs) proceeds in accordance with their microenvironment. Particularly, mesenchymal cells around portal veins regulate the differentiation and ductular morphogenesis of cholangiocytes in the developing liver; however, further studies are needed to fully understand the arrangement of IHBDs into a continuous hierarchical network. This study aims to clarify the interaction between biliary and liver mesenchymal cells during IHBD formation. To identify candidate factors contributing to this cell–cell interaction, mesenchymal cells were isolated from embryonic day 16.5 matrix metalloproteinase 14 (MMP14)‐deficient (knockout [KO]) mice livers, in which IHBD formation is retarded, and compared with those of the wild type (WT). WT mesenchymal cells significantly facilitated the formation of luminal structures comprised of hepatoblast‐derived cholangiocytes (cholangiocytic cysts), whereas MMP14‐KO mesenchymal cells failed to promote cyst formation. Comprehensive analysis revealed that expression of vasoactive intestinal peptide (VIP) was significantly suppressed in MMP14‐KO mesenchymal cells. VIP and VIP receptor 1 (VIPR1) were mainly expressed in periportal mesenchymal cells and cholangiocytic progenitors during IHBD development, respectively, in vivo. VIP/VIPR1 signaling significantly encouraged cholangiocytic cyst formation and up‐regulated tight junction protein 1, cystic fibrosis transmembrane conductance regulator, and aquaporin 1, in vitro. VIP antagonist significantly suppressed the tight junction assembly and the up‐regulation of ion/water transporters during IHBD development in vivo. In a cholestatic injury model of adult mice, exogenous VIP administration promoted the restoration of damaged tight junctions in bile ducts and improved hyperbilirubinemia. Conclusion: VIP is produced by periportal mesenchymal cells during the perinatal stage. It supports bile duct development by establishing tight junctions and up‐regulating ion/water transporters in cholangiocytes. VIP contributes to prompt recovery from cholestatic damage through the establishment of tight junctions in the bile ducts.

Background/Aims Mucosal healing (MH) of distal lesions in ulcerative colitis (UC) has recently been confirmed with budesonide 2-mg foam (BF) treatment in 2 clinical trials; however, few studies have investigated the predictive factors for complete MH. Methods We conducted a post hoc analysis using pooled data from phase II and III clinical trials evaluating the efficacy and safety of BF for UC. Additionally, we analyzed the relationships between complete MH and baseline factors and clinical symptoms from baseline to week 6. Results Among the 291 Japanese patients from the 2 pooled clinical studies, 119 patients in the BF twice a day group and 117 in the placebo group were included in the full analysis set. The proportion of patients with a rectal bleeding (RB) subscore of 0 was significantly higher in the BF group than in the placebo group after a 5-day treatment (P

Background/Aims PF-00547659 is a monoclonal antibody against human mucosal addressin cell adhesion molecule-1 (MAdCAM-1) that prevents the binding of α4β7+ lymphocytes to MAdCAM-expressing sites in the gastrointestinal tract with high affinity and selectivity, and is being developed for the treatment of Crohn’s disease (CD). Methods OPERA is a randomized, multicenter, double-blind, placebo-controlled study to investigate the efficacy, safety, and pharmacokinetics of PF-00547659 following subcutaneous administration in subjects with active CD, a history of failure or intolerance to anti-tumor necrosis factor and/or immunosuppressants, high-sensitivity C-reactive protein > 3.0 mg/L, and ulcers on colonoscopy. The primary endpoint was Crohn’s Disease Activity Index-70 response at week 8 or 12. Subpopulation analyses for Asian subjects were performed as some differences are observed in genetics and clinical phenotypes in Asian CD patients compared with Western patients. Results In this study, 265 CD subjects were randomized, with a subpopulation of 21 subjects (8 Japanese and 13 Korean) defined as the Asian population. In the overall and Asian populations; PF-00547659 was pharmacologically active as evidenced by soluble MAdCAM and circulating β7+ central memory CD4+ T-lymphocytes, although no clear evidence of efficacy was observed in any clinical endpoints; pharmacokinetics of PF-00547659 in the Asian subpopulation was generally comparable to the overall population; and the safety profile of PF-00547659 appeared acceptable up to 12 weeks of treatment. Conclusions In the overall and Asian populations, efficacy of PF-00547659 could not be demonstrated using any clinical endpoints compared with placebo. Pharmacokinetics and safety of PF-00547659 were generally comparable. Further studies with larger numbers of patients are required to confirm our results. (Trial Registration Number: NCT01276509)

Background/Aims An interim analysis of post-marketing surveillance of CT-P13, an infliximab biosimilar, was performed to evaluate its safety and efficacy in Japanese patients with inflammatory bowel disease. Methods Patients were prospectively enrolled between November 2014 and March 2017, after the launch of CT-P13 in Japan, and case report forms of patients followed for at least 4 months were analyzed as of July 2018. Results Of 523 patients in the analysis set, 372 remained on CT-P13 therapy, while 54 (20.2%) of 267 patients with Crohn’s disease, and 97 (37.9%) of 256 patients with ulcerative colitis were withdrawn during follow-up. A total of 144 adverse drug reactions (ADRs) were reported in 106 patients (20.3%). Infusion reaction was the most frequent ADR observed in 49 patients (9.4%). Efficacy parameters decreased immediately after the start of treatment in naïve patients to anti-tumor necrosis factor-α antibody. In the patients switched from originator infliximab for nonmedical reasons, the decreased parameters due to proceeded treatment with the originator were maintained in low ranges, and the treatment continuation rate was high with low ADR incidence. In contrast, in patients switched for medical reasons such as adverse event or loss of response, the incidence of ADRs was high. However, the efficacy parameters were improved, and the treatment continuation rate was not significantly different from that of the naïve patient group. Conclusions In this interim analysis, CT-P13 was comparable to the originator infliximab with respect to ADRs and efficacy, and is therefore considered to be a cost-efficient interchangeable biosimilar for Japanese patients with inflammatory bowel disease.

Ikarugamycin (IK) is an antibiotic which has been reported to have a variety of functions, such as inhibition of clathrin-mediated endocytosis (CME), anti-tumor effects and regulation of the immune system. Whether IK influences cytokine production is poorly understood. We have investigated the relationship between IK and production of tumor necrosis factor-α (TNF). TNF plays a pivotal role in pathogenesis of many diseases. Although the dynamics of soluble TNF (sTNF) has been widely explored so far, the functions of the membrane form of TNF (mTNF) have not been fully elucidated. We demonstrated that IK increases the amount of mTNF and prolongs the duration of TNF expression. This effect is unrelated to the shedding activity of disintegrin and metalloproteinase domain-containing protein 17 (ADAM 17). Our results revealed that there is a mechanism to terminate inflammation at the cellular level which IK dysregulates. Furthermore, IK can be a tool to study TNF signaling due to its effect of increasing mTNF expression.

Sporadic adenoma or adenocarcinoma is often detected during endoscopic surveillance of patients with ulcerative colitis (UC). However, it is occasionally difficult to distinguish these neoplasms from dysplasia or colitis-associated cancers because of the influence of inflammation. However, the influence of inflammation on sporadic neoplasms is not well characterised. To assess this influence, we established a long-term inflammation model of colon cancer cells by inflammatory stimulation with tumour necrosis factor-α, flagellin and interleukin-1β for 60 weeks. Then, the malignant phenotypes were evaluated using the MTS assay, Annexin V fluorescence assay, cell migration assay and sphere formation assay. The influence of P53 function on these phenotypes was assessed with a TP53 mutation model using the CRISPR/Cas9 system. A long-term inflammation model of LS174T cells was established for the first time with continuous inflammatory signalling. Chronic inflammation induced apoptosis and suppressed the proliferation and stemness of these cancer cells via the action of P53. It also enhanced the invasiveness of LS174T cells. Moreover, these phenotypic changes and changes in inflammatory signalling were recoverable after the removal of inflammatory stimuli, suggesting that colon cancer cells have higher plasticity than normal intestinal epithelial cells. In conclusion, our results suggest that sporadic neoplasms in patients with UC are affected by chronic inflammation but are not essentially altered.

Inflammatory bowel disease (IBD) is an idiopathic, multi-etiological disease characterized by inflammation and mucosal destruction of the gastrointestinal tract. Despite the remarkable advance in immunomodulating therapies, there still remains a certain population of patients who are refractory to conventional as well as biologic therapies and fail to achieve mucosal healing. To improve the prognosis of those patients, at least 2 types of stem cells have been tested for their potential therapeutic use. Transplantation of hematopoietic stem cells or mesenchymal stem cells have been tested in several clinical studies, but their beneficial effect still remains controversial. In this review, we would like to overview the recent clinical challenges of stem cell-based therapies in IBD and also introduce our new therapeutic plan of intestinal stem cell transplantation for IBD, based on our ex vivo intestinal organoid culture technique.

Results of recent studies have shown that disease models using human induced pluripotent stem (iPS) cells have recapitulated the pathophysiology of genetic liver diseases, viral hepatitis and hepatic fibrosis. The utilization of human iPS cells as a model of liver diseases has several substantial advantages compared with primary hepatocytes and cancer cell lines, such as the potential for unlimited expansion and similarity of biological characteristics to normal liver cells. In this review, we have focused on modeling liver diseases using human iPS cells and discussed the experimental evidence that supports the utility of such disease models, including that in our recent studies. Genetically modified or patient-derived human iPS cells can mimic congenital liver disease phenotypes. Human iPS-derived hepatic cells can be infected with the hepatitis viruses. The co-culture of human iPS-derived hepatocytes and mesenchyme partially mimics the process of liver fibrosis. Human iPS cell-derived hepatic cells and the co-culture system of such cells will contribute to the progress of studies on the pathophysiology of genetic and non-genetic liver diseases and development of novel therapeutic strategies for treating liver diseases.

Notch signaling is activated in the intestinal epithelial cells (IECs) of patients with inflammatory bowel disease (IBD), and contributes to mucosal regeneration. Our previous study indicated that TNF-α and Notch signaling may synergistically promote the expression of the intestinal stem cell (ISC) marker OLFM4 in human IECs. In the present study, we investigated the gene regulation and function of OLFM4 in human IEC lines. We confirmed that TNF-α and Notch synergistically upregulate the mRNA expression of OLFM4. Luciferase reporter assay showed that OLFM4 transcription is regulated by the synergy of TNF-α and Notch. At the protein level, synergy between TNF-α and Notch promoted cytoplasmic accumulation of OLFM4, which has potential anti-apoptotic properties in human IECs. Analysis of patient-derived tissues and organoids consistently showed cytoplasmic accumulation of OLFM4 in response to NF-κB and Notch activation. Cytoplasmic accumulation of OLFM4 in human IECs is tightly regulated by Notch and TNF-α in synergy. Such cytoplasmic accumulation of OLFM4 may have a cell-protective role in the inflamed mucosa of patients with IBD.

Background/AimsTofacitinib is an oral, small-molecule Janus kinase inhibitor being investigated for ulcerative colitis (UC). In OCTAVE Induction 1 and 2, patients with moderately to severely active UC received placebo or tofacitinib 10 mg twice daily (BID) for 8 weeks. Clinical responders in OCTAVE Induction were re-randomized to 52 weeks' therapy with placebo, tofacitinib 5 mg BID, or tofacitinib 10 mg BID.MethodsWe conducted post-hoc efficacy and safety analyses of East Asian patients in OCTAVE Induction 1 and 2 and OCTAVE Sustain.ResultsA total of 121 East Asian (Japan, Korea, and Taiwan) patients were randomized in OCTAVE Induction 1 and 2 (placebo, n=26; tofacitinib 10 mg BID, n=95), and 63 in OCTAVE Sustain (placebo, n=20; tofacitinib 5 mg BID, n=22; tofacitinib 10 mg BID, n=21). At week 8 of OCTAVE Induction 1 and 2, 18.9% of patients (18/95) achieved remission with tofacitinib 10 mg BID versus 3.8% (1/26) with placebo. In OCTAVE Sustain, the week 52 remission rates were 45.5% (10/22), 47.6% (10/21), and 15.0% (3/20) with 5 mg BID, 10 mg BID, and placebo, respectively. Adverse event rates were similar between groups in OCTAVE Induction and numerically higher with tofacitinib in OCTAVE Sustain. Serious adverse event rates were similar across groups in all studies. Infections were numerically more frequent with tofacitinib than placebo. Increases in serum lipid levels were observed with tofacitinib.ConclusionsIn East Asian patients with UC, tofacitinib demonstrated numerically greater efficacy versus placebo as induction and maintenance therapy, with a safety profile consistent with the global study population. ClinicalTrials.gov: NCT01465763; NCT01458951; NCT01458574.

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease of the gastrointestinal tract, with increasing prevalence worldwide. IBD Ahead is an international educational program that aims to explore questions commonly raised by clinicians about various areas of IBD care and to consolidate available published evidence and expert opinion into a consensus for the optimization of IBD management. Given differences in the epidemiology, clinical and genetic characteristics, management, and prognosis of IBD between patients in Japan and the rest of the world, this statement was formulated as the result of literature reviews and discussions among Japanese experts as part of the IBD Ahead program to consolidate statements of factors for disease prognosis in IBD. Evidence levels were assigned to summary statements in the following categories: disease progression in CD and UC; surgery, hospitalization, intestinal failure, and permanent stoma in CD; acute severe UC; colectomy in UC; and colorectal carcinoma and dysplasia in IBD. The goal is that this statement can aid in the optimization of the treatment strategy for Japanese patients with IBD and help identify high-risk patients that require early intervention, to provide a better long-term prognosis in these patients.

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from 9 Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 1 of the statements comprised 2 parts: risk of TB infection Recommendaduring anti-TNF therapy, and screening for TB infection prior to commencing anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Summary: ATOH1 is a master transcription factor for the secretory lineage differentiation of intestinal epithelial cells (IECs). However, the comprehensive contribution of ATOH1+ secretory lineage IECs to the homeostasis, repair, and tumorigenesis of the intestinal epithelium remains uncertain. Through our ATOH1+ cell-lineage tracing, we show here that a definite number of ATOH1+ IECs retain stem cell properties and can form ATOH1+IEC-derived clonal ribbons (ATOH1+ICRs) under completely homeostatic conditions. Interestingly, colonic ATOH1+ IECs appeared to exhibit their stem cell function more frequently compared with those of the small intestine. Consistently, the formation of ATOH1+ICRs was significantly enhanced upon dextran sodium sulfate colitis-induced mucosal damage. In addition, colonic ATOH1+ IECs acquired tumor stem cell-like properties in the azoxymethane-DSS tumor model. Our results reveal an unexpected contribution of colonic ATOH1+ IECs to maintaining the stem cell population under both homeostatic and pathologic conditions and further illustrate the high plasticity of the crypt-intrinsic stem cell hierarchy.

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from 9 Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 2 of the statements comprised 3 parts: management of latent TB in preparation for anti-TNF therapy, monitoring during anti-TNF therapy, and management of an active TB infection after anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Jingmen tick virus (JMTV) and the related jingmenvirus-termed Alongshan virus are recognized as globally emerging human pathogenic tick-borne viruses. These viruses have been detected in various mammals and invertebrates, although their natural transmission cycles remain unknown. JMTV and a novel jingmenvirus, tentatively named Takachi virus (TAKV), have now been identified during a surveillance of tick-borne viruses in Japan. JMTV was shown to be distributed across extensive areas of Japan and has been detected repeatedly at the same collection sites over several years, suggesting viral circulation in natural transmission cycles in these areas. Interestingly, these jingmenviruses may exist in a host tick species-specific manner. Vertical transmission of the virus in host ticks in nature was also indicated by the presence of JMTV in unfed host-questing Amblyomma testudinarium larvae. Further epidemiological surveillance and etiological studies are necessary to assess the status and risk of jingmenvirus infection in Japan.

In Kenya, there is an urgent need to strengthen domestic rice production to improve food security. To achieve this, it is necessary to develop a value chain of competitive rice varieties that creates new value over and above that of conventional varieties. In this study, we focused on locally grown japonica rice produced in the Mwea area, which has recently begun to be distributed in Nairobi. Through interviews with Japanese restaurants, Japanese food stores, and consumers as well as interviews with stakeholders in the value chain the market price, consumer acceptability, and profitability of locally grown japonica rice were determined. We evaluated the value chain of locally grown japonica rice based on the interaction between the potential demand and a value chain analysis and examined improvement measures to establish the value chain. The results showed that 76% of consumers who eat staple foods other than rice rated locally grown japonica rice as “very good” or “good”, indicating that it may be acceptable to those who do not usually eat rice. The net profits for locally grown japonica rice were higher than those of conventional rice at the production, processing, and distribution stages, which is an advantage for producers and demonstrates that the elimination of middlemen is effective and highly profitable for each stakeholder. In contrast, the consumer price of locally grown japonica rice was higher than that of conventional rice, indicating that some challenges remain to be overcome. Our estimation approach will allow further study of target values such as selling price in other desired value chains. Together, our findings suggest the potential of the locally grown japonica rice value chain to contribute to the strengthening of domestic rice production.

From the perspective of national food security, strengthening domestic rice production is an urgent issue for Kenya. For this purpose, it is helpful to consider varieties that generate novel and competitive values different from those of conventional varieties. Recently, domestic japonica rice, which is now being distributed, has become an attractive variety with a high market price and its production is expected to increase. Although it is competitive and promising as a crop for small-scale farmers, the production stage costs and benefits are not clear. Thus, a study was conducted to perform a cost–benefit analysis of japonica rice in comparison to conventional rice at the production stage and evaluate strategies for strengthening the domestic production of rice. We conducted an experimental cultivation of japonica rice in the Mwea region, Kenya, where japonica rice is produced. As a result, although production costs for japonica rice are higher than costs for conventional varieties (24.46 KSh/kg versus 22.63 KSh/kg), when a high-yielding variety is grown (6.44 tons/ha for japonica rice compared to 6.07 tons/ha for conventional rice), a larger net profit can be obtained (65.54 KSh/kg versus 32.37 KSh/kg). We believe that initiatives to improve difficulties at the production stage would make the production of both japonica rice and conventional rice more economically viable and facilitate strengthening of the overall domestic rice production.

Ileocecal resection (ICR), one of several types of intestinal resection that results in short bowel syndrome (SBS), causes severe clinical disease in humans. We here describe a mouse model of massive ICR in which 75% of the distal small intestine is removed. We demonstrate that mice underwent 75% ICR show severe clinical signs and high mortality, which may recapitulate severe forms of human SBS, despite an adaptive response throughout the remnant intestine. By using this model, we also investigated whether the epithelium of the remnant intestine shows enhanced expression of factors involved in region-specific functions of the ileum. Cubn mRNA and its protein product, which play an essential role in vitamin B12 absorption in the ileum, are not compensatory up-regulated in any part of the remnant intestine, demonstrating a clear contrast with post-operative up-regulation of genes involved in bile acid absorption. Our study suggests that functional adaptation by phenotypical changes in the intestinal epithelium is not a general feature for nutrient absorption systems that are confined to the ileum. We also propose that the mouse model developed in this study will become a unique system to facilitate studies on SBS with ICR in humans.

Abstract Background Efficacy of maintenance therapy in ulcerative colitis (UC) in the remission stage has been reported to depend on release profile or dosing regimen of oral 5-aminosalicylic acid (5-ASA) products used. Aim of this study is to investigate real life results in using oral 5-ASA products for maintaining mild to moderate UC patients in Japan. Methods Adult UC outpatients treated with oral 5-ASA products were enrolled from 379 sites in Japan between July 2012 and July 2013, and followed for 52 weeks. Remission maintenance rate was evaluated by products and dosages. Factors affecting recurrence were also examined. Results A total of 5695 UC patients were registered. Among the 4677 patients in whom remission maintenance was observed, remission maintenance rate at week 52 was 80.2%. As for disease duration and dosage, Pentasa® 4000 mg/day in 2 divided doses was administered to 480 (21.0%) patients in remission and 341 (46.6%) patients in active stage, and Asacol® 3600 mg/day in 3 divided doses was administered to 696 (46.4%) patients in remission and 473 (67.3%) patients in active stage. The remission maintenance rate at week 52 by dosage and frequency did not significantly differ between Pentasa® Tablets at 4000 mg/day in 2 divided doses (76.5%) and Asacol® Tablets at 3600 mg/day in 3 divided doses (76.1%, P = 0.7868). Factors affecting the risk of relapse in UC were identified. Significantly persistent remission maintenance was noted in patients in whom duration of remission maintenance until enrollment was 12 to

The data on the immunohistochemical analysis of conditional Notch ligand knockout mice is presented. Targeted deletion of Jag1, Dll1, Dll4, or Dll1 plus Dll4 in Lgr5+ve cells was induced by a Cre-mediated gene recombination, and differentiation or proliferation of the intestinal epithelial cells was examined by immunohistochemistry. These data are the extension of the data presented and discussed in the paper entitled “Indispensable role of non-canonical Notch signaling in the proliferation of Apc-deficient intestinal tumors“ (Nakata et al., Submitted for publication) [1].

BackgroundBudesonide foam is effective in inducing clinical remission in ulcerative colitis (UC) patients with active proctosigmoiditis. The aim of this study was to evaluate the duration of remission and predictors of relapse in UC patients who achieved clinical remission and mucosal healing by 6-week treatment with topical budesonide.MethodsThis is a retrospective, observational, multicenter study with a 2-year follow-up period. UC patients who were treated with budesonide foam in phase 2 or phase 3 clinical trials and achieved both clinical remission and mucosal healing were enrolled.ResultsAmong 84 patients who met the eligibility criteria, 60 participated in the study. Eighteen of the 60 patients (30.0%; 95% confidence interval [CI]: 18.9-43.2) experienced no relapse (i.e., maintenance of remission) during the 2-year follow-up period. The median relapse-free survival time was 0.82 years (95% CI: 0.51-1.52). Of 37 patients with a Mayo endoscopic subscore of 0 after inducing remission with budesonide foam, 25 (67.6%) relapsed within 2 years. Patients with a disease duration of 5 years, and the hazard ratio was 2.38 (95% CI: 1.04-5.45).ConclusionThis is the first study to evaluate the short- to middle-term prognosis in UC patients who achieved mucosal healing with topical preparations. After inducing remission by budesonide foam, treatment for maintaining remissions and strict follow-up may be needed for patients with shorter disease duration.

[This corrects the article DOI: 10.1371/journal.pone.0212989.].

BackgroundVedolizumab safety and efficacy have been established in many populations all over the world, but have never been studied in Japan. We report results from a Phase 3, randomized, double-blind, placebo-controlled study of vedolizumab in Japanese patients with active ulcerative colitis (UC).MethodsPatients with moderate-to-severe UC were enrolled into Cohort 1 (double-blinded) or Cohort 2 (open-label) in the induction phase. Cohort 1 was randomized 2:1 to receive 300 mg vedolizumab or placebo, while Cohort 2 received vedolizumab 300 mg only, at Weeks 0, 2, and 6. Patients from Cohorts 1 and 2 showing a clinical response to vedolizumab at Week 10 were randomized 1:1 to receive vedolizumab or placebo (double-blinded) at Week 14 and then every 8 weeks up to Week 54 as the maintenance phase. The primary endpoint was clinical response at Week 10, for the induction phase, and clinical remission at Week 60, for the maintenance phase.ResultsA total of 292 patients were enrolled into the induction phase (246 in Cohort 1, 46 in Cohort 2); 83 patients achieved response to vedolizumab and were subsequently enrolled into the maintenance phase. Clinical response rates at Week 10 were 39.6% (65/164) and 32.9% (27/82) in the vedolizumab and placebo groups in Cohort 1, respectively (adjusted odds ratio [AOR] = 1.37, 95% CI 0.779-2.399; p = 0.2722). In the maintenance phase, clinical remission rate at Week 60 was significantly higher in the vedolizumab group, at 56.1% (23/41), versus 31.0% (13/42) for placebo (AOR = 2.88, 95% CI 1.168-7.108; p = 0.0210). Most adverse events were mild to moderate in intensity, and no deaths occurred during the study period.ConclusionsVedolizumab showed numerically greater efficacy compared with placebo as induction therapy, but the difference was not statistically significant. Vedolizumab was significantly superior to placebo as maintenance therapy in Japanese patients with UC. Vedolizumab has favourable safety and tolerability in these patients.Trial registrationClinicalTrials.gov: NCT02039505.

For the control of Crohn's disease (CD) a thorough assessment of the small intestine is essential; several modalities may be utilized, with cross-sectional imaging being important. Magnetic resonance (MR) enterography, i.e., MRE is recommended as a modality with the highest accuracy for CD lesions. MRE and MR enteroclysis are the two methods performed following distension of the small intestine. MRE has sensitivity and specificity comparable to computed tomography enterography (CTE); although images obtained using MRE are less clear compared with CTE, MRE does not expose the patient to radiation and is superior for soft-tissue contrast. Furthermore, it can assess not only static but also dynamic and functional imaging and reveals signs of CD, such as abscess, comb sign, fat edema, fistula, lymph node enhancement, less motility, mucosal lesions, stricture, and wall enhancement. Several indices of inflammatory changes and intestinal damage have been proposed for objective evaluation. Recently, diffusion-weighted imaging has been proposed, which does not need bowel preparation and contrast enhancement. Comprehension of the characteristics of MRE and other modalities is important for better management of CD.

Background/AimsAnti-tumor necrosis factor drugs (anti-TNF) and thiopurines are important treatment options in patients with inflammatory bowel disease (IBD), including during pregnancy. However, there are limited data on the benefit/risk profile of anti-TNF and thiopurines during pregnancy in Asia. The aim of this study was to analyze pregnancy outcomes of female Japanese IBD patients treated with anti-TNF and/or thiopurines.MethodsThis cross-sectional study assessed pregnancy outcomes in 72 women with IBD. Pregnancy outcomes were compared among 31 pregnancies without exposure to infliximab (IFX), adalimumab (ADA), or thiopurines; 24 pregnancies with exposure to anti-TNF treatment (23 IFX, 1 ADA); 7 pregnancies with exposure to thiopurines alone; and 10 pregnancies with exposure to both IFX and thiopurines.ResultsThirty-five of the 41 pregnancies (85.3%) that were exposed to anti-TNF treatment and/or thiopurines resulted in live births after a median gestational period of 38 weeks. Of the 35 live births, 3 involved premature deliveries; 7, low birth weight; and 1, a congenital abnormality. There were 6 spontaneous abortions in pregnancies that were exposed to anti-TNF treatment (17.7%). Pregnancy outcomes among the 4 groups were similar, except for the rate of spontaneous abortions (P =0.037).ConclusionsExposure to anti-TNF treatment or thiopurines during pregnancy was not related to a higher incidence of adverse pregnancy outcomes in Japanese IBD patients except for spontaneous abortion.

We previously performed a randomized controlled trial (RCT) comparing targeted and random biopsy in neoplasia detection in patients with ulcerative colitis (UC), which showed the short-term effectiveness of targeted biopsy with one-time colonoscopy. In this retrospective cohort study, we investigated the long-term effectiveness of targeted biopsy in tertiary care hospitals, using the follow-up data from patients with UC for ≥ 8 years who had enrolled in the initial RCT. The primary outcome was death from colorectal cancer (CRC). Secondary outcomes were advanced neoplasia (CRC or high-grade dysplasia) and colectomy due to neoplasia after the RCT. We compared these outcomes between target and random groups. Data on 195 of the 221 patients (88.2%) enrolled in the previous RCT were collected from 28 institutions between 2008 and 2019. No patients died of CRC in either group, with a median 8.8-year follow-up demonstrating a robustness for targeted biopsy in terms of CRC death prevention. Advanced neoplasia was detected in four and three patients in the target and random groups, respectively. Colectomy was required due to neoplasia in three patients in each group. The chance of developing CRC in patients with a negative colonoscopy was low, and the targeted biopsy appeared effective in this population. Conversely, patients found with low-grade dysplasia at initial RCT have 10-fold higher risk of progression to high-grade dysplasia and/or CRC. Ten extracolonic malignancies were observed during the follow-up, resulting in four deaths. Panchromoendoscopy was used only in 4.6% and targeted biopsy was only performed in 59.1% of colonoscopies. We recommend targeted biopsy rather than > 33 random biopsies in real-world settings under adequate observation by specialists.

Japanese encephalitis (JE) remains a public health concern in several countries, and the Culex mosquito plays a central role in its transmission cycle. Culex mosquitoes harbor a wide range of viruses, including insect-specific viruses (ISVs), and can transmit a variety of arthropod-borne viruses (arboviruses) that cause human and animal diseases. The current trend of studies displays enhanced efforts to characterize the mosquito virome through bulk RNA sequencing due to possible arbovirus−ISV interactions; however, the extent of viral diversity in the mosquito taxon is still poorly understood, particularly in some disease vectors. In this study, arboviral screening and RNA virome analysis of Culex tritaeniorhynchus and C. pseudovishnui, which are part of the Culex vishnui subgroup mosquitoes, were performed. Results from these two mosquito species, known as the major vectors of JE virus (JEV) in Asia, collected in three prefectures in Japan were also compared with the sympatric species C. inatomii. A total of 27 viruses, including JEV, were detected from these Culex mosquitoes. Molecular and phylogenetic analyses of the detected viruses classified 15 of the 27 viruses as novel species, notably belonging to the Flaviviridae, Rhabdoviridae, Totiviridae, and Iflaviridae families. The successful isolation of JEV genotype I confirmed its continuous presence in Japan, suggesting the need for periodic surveillance. Aside from JEV, this study has also reported the diversity of the RNA virome of disease vectors and broadened the knowledge on mosquito virome profiles containing both arbovirus and ISV. Mosquito taxon seemed to contribute largely to the virome structure (e.g., virome composition, diversity, and abundance) as opposed to the geographical location of the mosquito species. This study therefore offers notable insights into the ecology and evolution of each identified virus and viral family. To the authors’ knowledge, this is the first study to characterize the viromes of the major JE vectors in Japan.

Background and study aims Colonoscopy is the gold standard for detecting colorectal adenomas and cancers. Endoscopic surveillance has been shown to be effective for preventing colorectal cancer. Although detection of colorectal polyps at an early stage is important, endoscopic visualization of early neoplasia can be difficult. The Endocuff is a new device that can be attached to the tip of the colonoscope to hold the colonic folds away from the field of view during withdrawal. The aim of this study was to compare the adenoma detection rate (ADR) and the mean number of adenomas detected per patient (MAP) achieved using Endocuff-assisted colonoscopy (EAC) and standard colonoscopy (SC). Patients and methods This randomized prospective study was conducted at two academic endoscopy departments in Japan. A total of 447 patients underwent a complete colonoscopic examination between April 2015 and September 2015. The EAC group included 239 patients. The cecal intubation rate, insertion time, withdrawal time, pain score, complications, polyp detection rate (PDR), ADR, the mean number of polyps detected per patient (MPP), and the MAP were assessed. Results There were no differences between the EAC and SC groups in terms of cecal intubation rate, insertion time, withdrawal time, or pain scores. The PDR in patients increased by about 12 % (61.9 % vs. 49.2 %, P = 0.013) and ADR increased by 15 % (52.5 % vs. 39.2 %, P = 0.001) with the use of the Endocuff. The advanced ADR was higher in the EAC group but no statistically significant difference was found (7.7 % vs. 4.6 %, P = 0.17). Both MPP and MAP were also higher in the EAC group (mean ± SD: 1.33 ± 1.43 vs. 0.83 ± 0.99 per patient; P