Control of the inheritance of regulatory T cell identity by a cis element in the Foxp3 locus.

In multicellular organisms, specialized functions are delegated to distinct cell types whose identity and functional integrity are maintained upon challenge. However, little is known about the mechanisms enabling lineage inheritance and their biological implications. Regulatory T (Treg) cells, which express the transcription factor Foxp3, suppress fatal autoimmunity throughout the lifespan of animals. Here, we show that a dedicated Foxp3 intronic element CNS2 maintains Treg cell lineage identity by acting as a sensor of the essential Treg cell growth factor IL-2 and its downstream target STAT5. CNS2 sustains Foxp3 expression during division of mature Treg cells when IL-2 is limiting and counteracts proinflammatory cytokine signaling that leads to the loss of Foxp3. CNS2-mediated stable inheritance of Foxp3 expression is critical for adequate suppression of diverse types of chronic inflammation by Treg cells and prevents their differentiation into inflammatory effector cells. The described mechanism may represent a general principle of the inheritance of differentiated cell states.

An essential role for the IL-2 receptor in Treg cell function.

Regulatory T cells (Treg cells), which have abundant expression of the interleukin 2 receptor (IL-2R), are reliant on IL-2 produced by activated T cells. This feature indicates a key role for a simple network based on the consumption of IL-2 by Treg cells in their suppressor function. However, congenital deficiency in IL-2R results in reduced expression of the Treg cell lineage-specification factor Foxp3, which has confounded experimental efforts to understand the role of IL-2R expression and signaling in the suppressor function of Treg cells. Using genetic gain- and loss-of-function approaches, we found that capture of IL-2 was dispensable for the control of CD4+ T cells but was important for limiting the activation of CD8+ T cells, and that IL-2R-dependent activation of the transcription factor STAT5 had an essential role in the suppressor function of Treg cells separable from signaling via the T cell antigen receptor.

Extrathymically Generated Regulatory T Cells Establish a Niche for Intestinal Border-Dwelling Bacteria and Affect Physiologic Metabolite Balance.

The mammalian gut microbiota provides essential metabolites to the host and promotes the differentiation and accumulation of extrathymically generated regulatory T (pTreg) cells. To explore the impact of these cells on intestinal microbial communities, we assessed the composition of the microbiota in pTreg cell-deficient and -sufficient mice. pTreg cell deficiency led to heightened type 2 immune responses triggered by microbial exposure, which disrupted the niche of border-dwelling bacteria early during colonization. Moreover, impaired pTreg cell generation led to pervasive changes in metabolite profiles, altered features of the intestinal epithelium, and reduced body weight in the presence of commensal microbes. Absence of a single species of bacteria depleted in pTreg cell-deficient animals, Mucispirillum schaedleri, partially accounted for the sequelae of pTreg cell deficiency. These observations suggest that pTreg cells modulate the metabolic function of the intestinal microbiota by restraining immune defense mechanisms that may disrupt a particular bacterial niche.

Auxiliary diagnosis of subepithelial lesions by impedance measurement during EUS-guided fine-needle biopsy.

BACKGROUND AND AIMS: EUS-guided FNA/biopsy (EUS-FNA/B) is the citerion standard for diagnosing subepithelial lesions (SELs); however, its diagnostic ability for SELs <20 mm is low. We developed a new diagnostic method to differentiate between GI stromal tumor (GIST) and non-GIST by measuring high-frequency impedance (H-impedance) using an EUS-FNB needle. METHODS: The H-impedance of gastric epithelial neoplasms from 16 cases were measured with a conventional impedance probe to confirm whether H-impedance is clinically useful for assessing cell density (study 1). The H-impedance values of exposed SELs from 25 cases with use of the conventional probe (study 2) and nonexposed SELs from 20 cases with use of the EUS-FNB needle probe (study 3) were measured to determine the diagnostic ability of H-impedance for differentiating GISTs from non-GISTs. RESULTS: H-impedance significantly positively correlated with cell density (P = .030) (study 1). The H-impedance of GIST (99.5) measured with a conventional probe was significantly higher than with those of the muscular layer (82.4) and leiomyoma (89.2) (P < .01) (study 2). The H-impedance of GIST measured with the EUS-FNB needle was also significantly higher than that of leiomyoma (GIST: 80.2 vs leiomyoma, 71.8; P = .015). The diagnostic yield of the impedance method for differentiating GISTs from non-GISTs had 94.4% accuracy, 88.9% sensitivity, 100% specificity, and 0.95 area under the curve. Diagnostic ability was not affected by lesion size (P = .86) (study 3). CONCLUSION: Auxiliary differential diagnosis between gastric GISTs and non-GISTs by the H-impedance measurement during EUS-FNB could be a good option, especially when the lesion is <20 mm.

Determination of Region-Specific Roles of the M3 Muscarinic Acetylcholine Receptor in Gastrointestinal Motility.

BACKGROUND: The specific role of the M3 muscarinic acetylcholine receptor in gastrointestinal motility under physiological conditions is unclear, due to a lack of subtype-selective compounds. AIMS: The objective of this study was to determine the region-specific role of the M3 receptor in gastrointestinal motility. METHODS: We developed a novel positive allosteric modulator (PAM) for the M3 receptor, PAM-369. The effects of PAM-369 on the carbachol-induced contractile response of porcine esophageal smooth muscle and mouse colonic smooth muscle (ex vivo) and on the transit in mouse small intestine and rat colon (in vivo) were examined. RESULTS: PAM-369 selectively potentiated the M3 receptor under the stimulation of its orthosteric ligands without agonistic or antagonistic activity. Half-maximal effective concentrations of PAM activity for human, mouse, and rat M3 receptors were 0.253, 0.345, and 0.127 µM, respectively. PAM-369 enhanced carbachol-induced contraction in porcine esophageal smooth muscle and mouse colonic smooth muscle without causing any contractile responses by itself. The oral administration of 30 mg/kg PAM-369 increased the small intestinal transit in both normal motility and loperamide-induced intestinal dysmotility mice but had no effects on the colonic transit, although the M3 receptor mRNA expression is higher in the colon than in the small intestine. CONCLUSIONS: This study provided the first direct evidence that the M3 receptor has different region-specific roles in the motility function between the small intestine and colon in physiological and pathophysiological contexts. Selective PAMs designed for targeted subtypes of muscarinic receptors are useful for elucidating the subtype-specific function.

Development of a new endoscopy system to visualize bilirubin for the diagnosis of duodenogastroesophageal reflux.

OBJECTIVES: Reflux hypersensitivity (RH) is a form of refractory gastroesophageal reflux disease in which duodenogastroesophageal reflux (DGER) plays a role. This study aimed to determine the usefulness of an endoscopy system equipped with image-enhanced technology for evaluating DGER and RH. METHODS: The image enhancement mode for detecting bilirubin and calculated values were defined as the Bil mode and Bil value, respectively. First, the visibility of the Bil mode was validated for a bilirubin solution and bile concentrations ranging from 0.01% to 100% (0.002-20 mg/dL). Second, visibility scores of the Bil mode, when applied to the porcine esophagus sprayed with a bilirubin solution, were compared to those of the blue laser imaging (BLI) and white light imaging (WLI) modes. Third, a clinical study was conducted to determine the correlations between esophageal Bil values and the number of nonacid reflux events (NNRE) during multichannel intraluminal impedance-pH monitoring as well as the utility of esophageal Bil values for the differential diagnosis of RH. RESULTS: Bilirubin solution and bile concentrations higher than 1% were visualized in red using the Bil mode. The visibility score was significantly higher with the Bil mode than with the BLI and WLI modes for 1% to 6% bilirubin solutions (P < 0.05). The esophageal Bil value and NNRE were significantly positively correlated (P = 0.031). The area under the receiver operating characteristic curve for the differential diagnosis of RH was 0.817. CONCLUSION: The Bil mode can detect bilirubin with high accuracy and could be used to evaluate DGER in clinical practice.

The treatment effects of acotiamide in esophagogastric outflow obstruction: a prospective longitudinal observational study.

OBJECTIVES: We have found that an altered lower esophageal sphincter (LES) accommodation response is an underlying cause of esophagogastric junction outflow obstruction (EGJOO). The objective of this study was to examine the treatment effect of acotiamide, a prokinetic agent which improves impaired gastric accommodation in functional dyspepsia, in patients with EGJOO. METHODS: A prospective observational longitudinal study was conducted between October 2014 and March 2020. Acotiamide (100 mg, 3 times a day) was administered to 25 patients with EGJOO for 4 weeks. High-resolution manometry (HRM) was performed just before and after 4 weeks of treatment. RESULTS: As the primary outcome, the extent of integrated relaxation pressure (IRP) after treatment (14.6, 12.1-22.0 mmHg) was significantly lower than that before treatment (19.4, 17.1-27.4 mmHg). The extent of LES accommodation index after treatment (32.7, 21.0-40.0 mmHg) was also significantly lower than that before treatment (39.3, 31.2-50.2 mmHg). Acotiamide normalized the IRP (< 15 mmHg) in 13 of 25 patients with EGJOO (52%), and the IRP was decreased in 20 of 25 patients with EGJOO (80%). As the secondary outcome, the total FSSG score in 25 patients with EGJOO before and after acotiamide treatment showed no significant difference. In a sub-analysis of 13 patients in whom EGJOO was normalized by acotiamide, however, dysphagia was reported to be significantly improved by acotiamide. CONCLUSIONS: Acotiamide has a treatment effect on patients with EGJOO via a reduction in the IRP level through the lowering of both the basal LES pressure and LES accommodation response. Dysphagia is a key symptom to be evaluated and treated in patients with EGJOO.

Discriminant equation using mucosally expressed cytokines and transcription factor for making definite diagnosis of inflammatory bowel disease unclassified.

BACKGROUND: The pathological conditions of UC and CD involved in inflammatory bowel disease-unclassified (IBD-U), UC with primary sclerosing cholangitis (PSC-UC), and UC with autoimmune pancreatitis type 2 (AIP-UC) remain unclear. Therefore, it is difficult to decide the appropriate treatments for these subtypes of UC. Our aim was to examine whether the discriminant equation using the mucosally expressed mediators designed as our previous study for IBD, could characterize IBD-U, PSC-UC, or AIP-UC. METHODS: A total of 56 patients including UC (n = 24), CD (n = 15), IBD-U (n = 10), PSC-UC (n = 4), and AIP-UC (n = 3), along with 9 control patients were enrolled in this study. Mucosally expressed inflammatory mediators related to Th1, Th2, Th17, and Treg were measured using quantitative PCR in endoscopic biopsies from the inflamed intestines of the patients. The IBD-U, PSC-UC or AIP-UC were characterized using discriminant analysis and principle component analysis. RESULTS: Through discriminant analyses, combinations of 3 to 7 inflammatory mediators were used to discriminate between UC and CD. Moreover, the identified 3 markers could diagnose patients with IBD-U as UC or CD with high accuracy. The distribution graph of inflammatory mediators using the principal component analysis revealed that PSC-UC and AIP-UC exhibited CD-like and UC-like features, respectively. CONCLUSIONS: The discriminant equation using mucosally expressed mediators of IL-13, IL-21 and T-bet can be used as a universal diagnostic tool not only for IBD-U but also to assess pathological conditions in PSC-UC and AIP-UC.

Clinical Characterization of Vonoprazan-Refractory Gastroesophageal Reflux Disease.

INTRODUCTION: The newly developed vonoprazan (a potassium-competitive acid blocker) has a greater ability to suppress gastric acid production than convention proton pump inhibitors (PPIs). The objective of the present study was to determine how vonoprazan influences the pathogenesis of refractory gastroesophageal reflux disease (GERD) in clinical practice. METHODS: Between March 2013 and November 2018, a total of 73 refractory GERD patients (34 in the conventional PPI group versus 39 in the vonoprazan group) were enrolled in this retrospective study. We then compared the underlying disease conditions between the 2 groups, examined by high-resolution manometry and multichannel intraluminal impedance/pH (MII-pH) monitoring. RESULTS: There was a significant difference in the proportion of underlying disease conditions, including erosive esophagitis, non-erosive reflux disease, reflux hypersensitivity, functional heartburn and oesophageal motility disorder (EMD), between the conventional PPI (6, 14, 23, 40 and 17% respectively) and vonoprazan groups (0, 0, 10, 49, and 41% respectively; p < 0.01). No cases of acid-related GERD were observed in the vonoprazan group. When the EMD patients were excluded, the lower oesophageal acid exposure time of the vonoprazan group (0.1% [0.0-0.5%], n = 23) was significantly lower than that of the conventional PPI group (0.35% [0.1-3.9%], n = 28; p < 0.05), and the gastric pH <4 holding time of the vonoprazan group (7.7% [0.7-34.5%]) was also significantly lower than that of the conventional PPI group (61.6% [49.4-74.3%], p < 0.01). CONCLUSIONS: Vonoprazan serves as a diagnostic tool to exclude acid-related GERD.

Interleukin-1ß as a Predictor of Glucocorticoid Response in Ulcerative Colitis.

BACKGROUND/AIM: Currently, there are no established biomarkers to differentiate between glucocorticoid (GC)-resistant and GC-sensitive ulcerative colitis (UC); however, interleukin (IL)-1ß could be one such candidate biomarker. The aim of this study was to investigate whether mucosally expressed IL-1ß could predict the response to GC in patients with UC. METHODS: A total of 27 mucosal tissue samples from 10 patients with GC-resistant UC (GC-resistant group), 9 patients with GC-sensitive UC (GC-sensitive group), and 8 control patients (control group) were analyzed by qRT-PCR for the expression of IL-1ß, GC receptor α (GRα), GRß, and other inflammatory mediators. Rachmilewitz endoscopic index (REI) between the GC-resistant and GC-sensitive groups was matched to avoid any potential influence of inflammation. RESULTS: The REI did not significantly differ between the GC-resistant and GC-sensitive groups. Mucosally expressed IL-1ß levels in the GC-resistant group were significantly higher than those in the GC-sensitive group. However, there were no significant differences in the expression levels of GRα, GRß, and other inflammatory mediators between the 2 groups. We could distinguish between the GC-resistant and GC-sensitive groups with a sensitivity of 90.0% and specificity of 77.8% based on mucosally expressed IL-1ß. CONCLUSIONS: Mucosally expressed IL-1ß can be used as a predictor of GC response in patients with UC.

Superiority of mucosal incision-assisted biopsy over ultrasound-guided fine needle aspiration biopsy in diagnosing small gastric subepithelial lesions: a propensity score matching analysis.

BACKGROUND: Gastric subepithelial lesions, including gastrointestinal stromal tumors, are often found during routine gastroscopy. While endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has been the gold standard for diagnosing gastric subepithelial lesions, alternative open biopsy procedures, such as mucosal incision-assisted biopsy (MIAB) has been reported useful. The aim of this study is to evaluate the efficacy of MIAB for the diagnosis of gastric SELs compared with EUS-FNAB. METHODS: We retrospectively analyzed medical records of 177 consecutive patients with gastric SELs who underwent either MIAB or EUS-FNAB at five hospitals in Japan between January 2010 and January 2018. Diagnostic yield, procedural time, and adverse event rates for the two procedures were evaluated before and after propensity-score matching. RESULTS: No major procedure-related adverse events were observed in either group. Both procedures yielded highly-accurate diagnoses once large enough samples were obtained; however, such successful sampling was more often accomplished by MIAB than by EUS-FNAB, especially for small SELs. As a result, MIAB provided better diagnostic yields for SELs smaller than 20-mm diameter. The diagnostic yields of both procedures were comparable for SELs larger than 20-mm diameter; however, MIAB required significantly longer procedural time (approximately 13 min) compared with EUS-FNAB. CONCLUSIONS: Although MIAB required longer procedural time, it outperformed EUS-FNAB when diagnosing gastric SELs smaller than 20-mm diameter.

Objective validity of the Japan Narrow-Band Imaging Expert Team classification system for the differential diagnosis of colorectal polyps.

BACKGROUND AND AIM: The Japan Narrow-Band Imaging (NBI) Expert Team (JNET) classification is a recently proposed NBI magnifying endoscopy-based classification system for colorectal tumors. Although the usefulness of this system has been reported by JNET experts, its objective validity remains unclear. We tested its validity and usefulness for the diagnosis of colorectal polyps by including colonoscopy experts and non-experts as test participants. METHODS: Forty NBI images of polyps of various JNET types were shown to 22 doctors (11 experts and 11 non-gastrointestinal [GI] trainees) who had not examined the patients. The doctors diagnosed the polyps based solely on the surface and vessel patterns in the magnified images and the JNET classification system. Concordance rates of their diagnoses with the pathological findings of the polyps were determined, and the results for experts and non-GI trainees were compared. RESULTS: Both for colonoscopy experts and non-GI trainees, the JNET classification system was particularly useful for classifying polyps as benign or malignant. Although the accuracy rates for classifying polyps into each JNET type varied among colonoscopy experts, those who were familiar with the JNET classification system were able to diagnose polyps with approximately 90% accuracy. Common mistakes were attributable to misunderstandings of the wording in the JNET classification chart and lack of proper training. CONCLUSION: The JNET classification system is a practical approach for the diagnosis of colorectal polyps. Training is required even for experienced colonoscopists to adopt the system properly. Common pitfalls must be shared among colonoscopists to improve the accuracy of the diagnosis.

Extrathymically generated regulatory T cells control mucosal TH2 inflammation.

A balance between pro- and anti-inflammatory mechanisms at mucosal interfaces, which are sites of constitutive exposure to microbes and non-microbial foreign substances, allows for efficient protection against pathogens yet prevents adverse inflammatory responses associated with allergy, asthma and intestinal inflammation. Regulatory T (T(reg)) cells prevent systemic and tissue-specific autoimmunity and inflammatory lesions at mucosal interfaces. These cells are generated in the thymus (tT(reg) cells) and in the periphery (induced (i)T(reg) cells), and their dual origin implies a division of labour between tT(reg) and iT(reg) cells in immune homeostasis. Here we show that a highly selective blockage in differentiation of iT(reg) cells in mice did not lead to unprovoked multi-organ autoimmunity, exacerbation of induced tissue-specific autoimmune pathology, or increased pro-inflammatory responses of T helper 1 (T(H)1) and T(H)17 cells. However, mice deficient in iT(reg) cells spontaneously developed pronounced T(H)2-type pathologies at mucosal sites--in the gastrointestinal tract and lungs--with hallmarks of allergic inflammation and asthma. Furthermore, iT(reg)-cell deficiency altered gut microbial communities. These results suggest that whereas T(reg) cells generated in the thymus appear sufficient for control of systemic and tissue-specific autoimmunity, extrathymic differentiation of T(reg) cells affects commensal microbiota composition and serves a distinct, essential function in restraint of allergic-type inflammation at mucosal interfaces.

The effects of commensal microbiota on immune cell subsets and inflammatory responses.

Billions of years of coevolution shaped the mutually beneficial relationships between metazoans and symbiotic commensal microorganisms. Commensal microorganisms profoundly affect the physiology of the host and provide the host with survival advantages in several ways, while they could also trigger pathogenic immune responses and threaten the well-being of the host. Recent advances in DNA sequencing technology enabled the analysis of commensal microbiota, and improvements in the techniques of culturing gut-resident microorganisms and of rearing gnotobiotic rodents have made it possible to assess the effect of individual component of microbial communities on host physiology. In this review, we discuss the current understanding of the interactions of commensal microbiota with the host immune system.

Evaluating the efficacy and safety of acotiamide in patients with esophagogastric junction outflow obstruction: study protocol for an investigator-initiated, multi-center, randomized, double-blind, placebo-controlled phase II trial.

BACKGROUND: We have determined that the impaired accommodation of the lower esophageal sphincter (LES) underlies the pathogenesis of esophagogastric junction outflow obstruction (EGJOO). We have also found that acotiamide may treat EGJOO by improving impaired LES accommodation. The effects of acotiamide in patients with EGJOO need to be further confirmed in a prospective study. METHODS: This trial is a multicenter, randomized, double-blind, placebo-controlled study to compare the efficacy and safety of acotiamide (300 mg/day or 600 mg/day) with those of a placebo in the treatment of patients with EGJOO. The primary endpoint will be the proportion of patients who report an improvement in symptom of food sticking in the chest after 4 weeks of treatment period 1. The secondary endpoints will be the proportion of patients with normalized integrated relaxation pressure (IRP), the value of change from baseline in the distal contractile integral, basal LES pressure, EGJOO-quality of life score, Gastrointestinal Symptom Rating Scale, and the correlation between IRP and each symptom score. During the 2-year trial period, 42 patients from five institutions will be enrolled. DISCUSSION: This trial will provide evidence to clarify the efficacy and safety of acotiamide as a treatment for patients with EGJOO. Acotiamide might help improve the quality of life of patients with EGJOO and is expected to prevent the progression of EGJOO to achalasia. TRIAL REGISTRATION: This study was approved by the Institutional Review Board (IRB) of Kyushu University Hospital as well as the local IRBs of the participating sites for clinical trials and registered in the Japan Registry of Clinical Trials (jRCT: 2071210072). The registration date is on October 11, 2021.

IFNgamma-dependent, spontaneous development of colorectal carcinomas in SOCS1-deficient mice.

Approximately 20% of human cancers are estimated to develop from chronic inflammation. Recently, the NF-kappaB pathway was shown to play an essential role in promoting inflammation-associated cancer, but the role of the JAK/STAT pathway, another important signaling pathway of proinflammatory cytokines, remains to be investigated. Suppressor of cytokine signaling-1 (SOCS1) acts as an important physiological regulator of cytokine responses, and silencing of the SOCS1 gene by DNA methylation has been found in several human cancers. Here, we demonstrated that SOCS1-deficient mice (SOCS1-/- Tg mice), in which SOCS1 expression was restored in T and B cells on a SOCS1-/- background, spontaneously developed colorectal carcinomas carrying nuclear beta-catenin accumulation and p53 mutations at 6 months of age. However, interferon (IFN)gamma-/- SOCS1-/- mice and SOCS1-/- Tg mice treated with anti-IFNgamma antibody did not develop such tumors. STAT3 and NF-kappaB activation was evident in SOCS1-/- Tg mice, but these were not sufficient for tumor development because these are also activated in IFNgamma-/- SOCS1-/- mice. However, colons of SOCS1-/- Tg mice, but not IFNgamma-/- SOCS1-/- mice, showed hyperactivation of STAT1, which resulted in the induction of carcinogenesis-related enzymes, cyclooxygenase-2 and inducible nitric oxide synthase. These data strongly suggest that SOCS1 is a unique antioncogene which prevents chronic inflammation-mediated carcinogenesis by regulation of the IFNgamma/STAT1 pathways.

Onigiri esophagography as a screening test for esophageal motility disorders.

BACKGROUND/AIMS: No screening test for esophageal motility disorder (EMD) has been established, the objective of this study is to examine the potential usefulness of our newly developed "Onigiri esophagography" combined with an obstruction level (OL) classification system in screening for EMD. METHODS: A total of 102 patients with suspected EMDs who underwent both high-resolution manometry (HRM) and Onigiri esophagography between April 2017 and January 2019 were examined. The EMD diagnosis was performed based on the Chicago classification version 3.0 by HRM. Onigiri esophagography was performed using a liquid medium (barium sulfate) followed by a solid medium, which consisted of an Onigiri (a Japanese rice ball) with barium powder. The extent of medium obstruction was assessed by the OL classification, which was defined in a stepwise fashion from OL0 (no obstruction) to OL4 (severe obstruction). RESULTS: The patients with OL0 (32.3%), OL1 (50.0%), OL2 (88.0%), OL3 (100.0%), and OL4 (100.0%) were diagnosed EMDs by HRM. The area under the curve, as determined by a receiver operating characteristic analysis, for the OL classification was 0.86. Using the cutoff value of OL1, the sensitivity and specificity were 87.3% and 61.3%, respectively, while using a cutoff value of OL2, the sensitivity and specificity were 73.2% and 90.3%, respectively. CONCLUSION: In conclusion, Onigiri esophagography combined with the OL classification system can be used as a screening test for EMDs with a cutoff value of OL1.

Efficacy of ultrasound endoscopy with artificial intelligence for the differential diagnosis of non-gastric gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are common subepithelial lesions (SELs) and require treatment considering their malignant potential. We recently developed an endoscopic ultrasound-based artificial intelligence (EUS-AI) system to differentiate GISTs from non-GISTs in gastric SELs, which were used to train the system. We assessed whether the EUS-AI system designed for diagnosing gastric GISTs could be applied to non-gastric GISTs. Between January 2015 and January 2021, 52 patients with non-gastric SELs (esophagus, n = 15; duodenum, n = 26; colon, n = 11) were enrolled. The ability of EUS-AI to differentiate GISTs from non-GISTs in non-gastric SELs was examined. The accuracy, sensitivity, and specificity of EUS-AI for discriminating GISTs from non-GISTs in non-gastric SELs were 94.4%, 100%, and 86.1%, respectively, with an area under the curve of 0.98 based on the cutoff value set using the Youden index. In the subanalysis, the accuracy, sensitivity, and specificity of EUS-AI were highest in the esophagus (100%, 100%, 100%; duodenum, 96.2%, 100%, 0%; colon, 90.9%, 100%, 0%); the cutoff values were determined using the Youden index or the value determined using stomach cases. The diagnostic accuracy of EUS-AI increased as lesion size increased, regardless of lesion location. EUS-AI based on gastric SELs had good diagnostic ability for non-gastric GISTs.

Improved esophagography screening for esophageal motility disorders using wave appearance and supra-junctional ballooning.

BACKGROUND: High-resolution manometry (HRM) is the gold standard for diagnosing esophageal motility disorders (EMDs); however, it requires specialized equipment. The development of more accessible screening examinations is expected. We evaluated the utility of barium esophagography (BE) screening using two novel findings to diagnose EMDs. METHODS: Between January 2013 and October 2020, 244 patients with suspected EMDs who underwent both HRM and BE were analyzed. The EMD diagnosis was based on HRM findings using Chicago Classification version 3.0. BE was performed using sequential esophagography with barium sulfate. Three conventional BE findings (air-fluid level, rosary-bead/corkscrew appearance, and absent/weak peristalsis) and two novel BE findings (wave appearance and supra-junctional ballooning) were used for diagnosis. RESULTS: The sensitivity and specificity of BE screening using the two novel findings and conventional findings to diagnose EMDs were 79.4% and 88%, respectively [area under the receiver-operating characteristic curve (AUC) = 0.837]. Without these novel findings, they were 63.9% and 96%, respectively (AUC = 0.800), respectively. Achalasia was highly correlated with the air-fluid level (88.7%). Absent contractility was highly correlated with absent/weak peristalsis (85.7%). Relatively high correlations were observed between distal esophageal spasm and rosary-bead/corkscrew appearance (60%), and between achalasia and wave appearance (59.7%). The intra-observer reproducibility and inter-observer agreement for individual BE findings were 84.4% and 75%, respectively. Wave appearance was associated with higher integrated relaxation pressure (IRP) and shorter distal latency. Supra-junctional ballooning was associated with higher IRP. CONCLUSIONS: BE screening using two additional novel findings to diagnose EMDs could be useful in general practice.

Involvement of interstitial cells of Cajal in nicotinic acetylcholine receptor-induced relaxation of the porcine lower esophageal sphincter.

The interstitial cells of Cajal (ICCs) play an important role in coordinated gastrointestinal motility. The present study aimed to elucidate whether or how ICCs are involved in the lower esophageal sphincter (LES) relaxation induced by stimulation of the nicotinic acetylcholine receptor. The application of 1,1-dimethyl-4-phenyl-piperazinium (DMPP; a nicotinic acetylcholine receptor agonist) induced a transient relaxation in the circular smooth muscle of the porcine LES. DMPP-induced relaxation was abolished by not only 1 µM tetrodotoxin but also the inhibition of ICC activity by pretreatment with 100 µM carbenoxolone (a gap junction inhibitor), pretreatment with 100 µM CaCCinh-A01 (an anoctamin-1 blocker acting as a calcium-activated chloride channel inhibitor), and pretreatment with Cl--free solution. However, pretreatment with 100 µM Nω-nitro-L-arginine methyl ester had little effect on DMPP-induced relaxation. Furthermore, DMPP-induced relaxation was inhibited by pretreatment with 1 mM suramin, a purinergic P2 receptor antagonist, but not by 1 µM VIP (6-28), a vasoactive intestinal peptide (VIP) receptor antagonist. Stimulation of the purinergic P2 receptor with adenosine triphosphate (ATP) induced relaxation, which was abolished by the inhibition of ICC activity by pretreatment with CaCCinh-A01. In conclusion, membrane hyperpolarization of the ICCs via the activation of anoctamin-1 plays a central role in DMPP-induced relaxation. ATP may be a neurotransmitter for inhibitory enteric neurons, which stimulate the ICCs. The ICCs act as the interface of neurotransmission of nicotinic acetylcholine receptor in order to induce LES relaxation.