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Background and Aims Intrapapillary capillary loops (IPCLs) are microvascular structures that correlate with the invasion depth of early squamous cell neoplasia and allow accurate prediction of histology. Artificial intelligence may improve human recognition of IPCL patterns and prediction of histology to allow prompt access to endoscopic therapy for early squamous cell neoplasia where appropriate. Methods One hundred fifteen patients were recruited at 2 academic Taiwanese hospitals. Magnification endoscopy narrow-band imaging videos of squamous mucosa were labeled as dysplastic or normal according to their histology, and IPCL patterns were classified by consensus of 3 experienced clinicians. A convolutional neural network (CNN) was trained to classify IPCLs, using 67,742 high-quality magnification endoscopy narrow-band images by 5-fold cross validation. Performance measures were calculated to give an average F1 score, accuracy, sensitivity, and specificity. A panel of 5 Asian and 4 European experts predicted the histology of a random selection of 158 images using the Japanese Endoscopic Society IPCL classification; accuracy, sensitivity, specificity, positive and negative predictive values were calculated. Results Expert European Union (EU) and Asian endoscopists attained F1 scores (a measure of binary classification accuracy) of 97.0% and 98%, respectively. Sensitivity and accuracy of the EU and Asian clinicians were 97%, 98% and 96.9%, 97.1%, respectively. The CNN average F1 score was 94%, sensitivity 93.7%, and accuracy 91.7%. Our CNN operates at video rate and generates class activation maps that can be used to visually validate CNN predictions. Conclusions We report a clinically interpretable CNN developed to predict histology based on IPCL patterns, in real time, using the largest reported dataset of images for this purpose. Our CNN achieved diagnostic performance comparable with an expert panel of endoscopists.

Chronic hepatitis C (CHC) is a major cause of cirrhosis, hepatocellular carcinoma (HCC), and mortality. Eliminating hepatitis C virus (HCV) can greatly improve long‐term outcomes. Several direct‐acting antiviral agents (DAAs), including sofosbuvir (SOF) plus different NS5A inhibitors, as well as non‐SOF‐based DAAs, including glecaprevir/pibrentasvir (GLE/PIB), have been approved for treating CHC genotype‐2 (GT‐2) patients in Taiwan. However, there is limited real‐world effectiveness data regarding these different regimens. Thus, we aimed to evaluate the real‐world efficacy in CHC GT‐2 patients who underwent these DAA regimens. We retrospectively enrolled CHC GT‐2 patients who were treated with SOF‐based DAAs or GLE/PIB at a single medical center. A total of 704 enrolled patients were treated with either SOF + ribavirin (RBV), SOF/daclatasvir (DCV) ± RBV, SOF/ledipasvir (LDV) ± RBV, SOF/velpatasvir (VEL) ± RBV, or with GLE/PIB. The overall sustained virological response (SVR) rate was 97.9%. The SVR rate was significantly lower in the SOF + RBV group (95.6%) than in the non‐SOF + RBV (98.9%) group, especially compared to the SOF/DCV (100%) and GLE/PIB groups (99.5%). Among patients treated with SOF + RBV, cirrhotic patients had significantly lower SVR rates than noncirrhotic patients (89.4% vs 98.2%). Multivariate analysis showed that patients with a younger age, hepatitis B virus coinfection, baseline cirrhosis, or those who received SOF + RBV were less likely to achieve SVR. In conclusion, for CHC GT‐2 patients, SOF in combination with DCV, LDV, or VEL, as well as GLE/PIB, achieved similar high efficacies, regardless of cirrhosis, treatment experience, or chronic kidney disease status. Therefore, the use of DAA therapy to eradicate HCV should not be delayed in these populations.

Background and study aims Endoscopic mucosal resection (EMR) is a standard method for removing sessile colorectal polyps ≥ 10 mm. Recently, underwater EMR (UEMR) has been introduced as a potential alternative. However, the effectiveness and safety of UEMR compared with conventional EMR is un clear. Patients and methods In this 1:1 propensity score (PS) matched retrospective cohort study, we compared the en bloc resection rates, procedure time, intraprocedural and delayed bleeding rates, and incidence of muscle layer injury. We also performed subgroup analyses by sizes of polyps ( Results Among 350 polyps in 315 patients from August 2012 to November 2017, we identified 121 PS-matched pairs. Mean polyp size was 16.8 mm. With similar en bloc resection rates (EMR: 82.6 % vs. UEMR: 87.6 %, rate difference: 5.0, 95 % confidence interval [95 % CI]: – 4 to 13.9 %), UEMR demonstrated a shorter resection time (10.8 min vs. 8.6 min, difference: – 2.2 min, 95 % CI: – 4.1 to – 0.3 min) and a lower intraprocedural bleeding rate (15.7 % vs. 5.8 %, rate difference: – 9.9 %, 95 % CI: – 17.6 to – 2.2 %). Incidence of delayed bleeding and muscle layer injury were low in both groups. For polyps Conclusions UEMR achieved an en bloc resection rate comparable to conventional EMR with less intraprocedural bleeding and a shorter procedure time.

Background Cytokine imbalance has been associated with chronic hepatitis C virus (HCV) infection. We hypothesized that cytokines have an important role in fibrosis development in HCV infection. Methods Data of 92 patients were analyzed retrospectively. Fluorescent Bead immunoassay was used to measure the following serum cytokine levels: Interferon γ, tumor necrosis factor α, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and IL-12. Various statistical analyses were used as appropriate. Results Of the 92 HCV-infected patients, 49 (53.3%) were male, 23 (25%) patients had advanced (fibrosis grades 3-4) fibrosis, and the mean age of the study population was 51.9 ± 9.4 years. Elevation of baseline IL-4 level (>490 pg/mL) was associated with liver fibrosis grade by χ test (odds ratio [OR] = 2.99; 95%, CI = 1.02-8.78; p = 0.042) and multivariate logistic regression (OR = 4.26; 95% CI = 1.13-16.02; p = 0.032). Also, IL-4 had strong diagnostic value in advanced liver fibrosis by using area under receiver operating characteristics curve analysis. Assessment of fibrosis score was consequently developed from our findings and compared with other noninvasive serum markers to assess liver fibrosis. Conclusion This study provides evidence that increased IL-4 expression predicted advanced liver fibrosis in treatment of naive HCV-infected patients. The newly developed "FIL4" score had good predictive value for advanced fibrosis before treatment and this value was even strong in HCV-genotype 1b patients.

BACKGROUND AND AIM Optimal staging of the invasion depth of superficial esophageal squamous cell carcinoma is vital before endoscopic treatment. A new simplified magnified narrow-band imaging (M-NBI) classification system based on vascular architecture has recently been developed by the Japan Esophageal Society; however, its validity remains uncertain. METHODS A total of 11 experienced and 11 inexperienced endoscopists were invited to join an endoscopic training program, which was composed of pretest, educational section, and post-test. The pretest and post-test sections included a set of endoscopic photos from 40 subjects with superficial esophageal squamous cell carcinoma with various invasion depths. Each subject appeared twice in the test, one with white-light imaging (WLI) only and the other with both WLI and M-NBI. The educational section included lectures and video demonstrations. RESULTS The accuracy of WLI alone and combined with M-NBI at baseline were 0.53, 0.57 and 0.43, 0.41 for the experienced and inexperienced endoscopists, respectively, which then improved to 0.57, 0.63 and 0.49, 0.52 after training. Inter-observer agreement (k-value) of WLI alone and combined WLI and M-NBI for the experienced and inexperienced endoscopists also improved from 0.61, 0.61, and 0.61, 0.53 to 0.68, 0.71, and 0.71, 0.59, respectively. Multivariate analysis revealed that the educational course but not experience in endoscopy, NBI, or magnification significantly improved the diagnostic accuracy. M-NBI had a significant additional benefit to WLI, with an improvement in accuracy from 36% to 56% for the cases with m3/sm1 cancers (P

Endoscopic diagnosis of gastrointestinal tumors consists of the following processes: (i) detection; (ii) differential diagnosis; and (iii) quantitative diagnosis (size and depth) of a lesion. Although detection is the first step to make a diagnosis of the tumor, the lesion can be overlooked if an endoscopist has no knowledge of what an early-stage 'superficial lesion' looks like. In recent years, image-enhanced endoscopy has become common, but white-light endoscopy (WLI) is still the first step for detection and characterization of lesions in general clinical practice. Settings and practice of routine esophagogastroduodenoscopy (EGD) such as use of antispasmodics, number of endoscopic images taken, and observational procedure are customarily decided in each facility in each country and are not well standardized. Therefore, in the present article, we attempted to outline currently available evidence and actual Japanese practice on gastric cancer screening using WLI, and provide tips for detecting EGC during routine EGD which could become the basis of future research.

Background and aim The mortality rate of gastric cancer (GC) is close to the incidence rate worldwide. However, in Korea and Japan, the mortality rate of GC is less than half of the incidence rate. We hypothesized that good-quality routine esophagogastroduodenoscopy (EGD) contributes to a high detection rate for early GC (EGC) and improves mortality in these countries. Methods To clarify the differences in routine EGD, a questionnaire survey was conducted in 98 Japanese and 53 international institutions. Results Prevalence of screening examination among routine EGD was higher in Japanese than in international institutions. Japanese endoscopists noted that endoscopic mucosal atrophy was the most significant risk factor for GC, whereas international endoscopists paid more attention to clinical information such as age, symptoms and family history. Antispasmodics, mucolytics and defoaming agents were used more frequently in Japanese institutions. The examination time was similar (mostly 5-10 min) between Japanese and international institutions. Japanese endoscopists took more pictures (>20 in almost all institutions) than international endoscopists (≤20 in two-thirds of institutions). In Japanese institutions, biopsy specimens were more frequently taken from areas of mucosal discoloration, unevenness or spontaneous bleeding rather than from obvious endoscopic lesions such as ulceration or polyps. In most Japanese institutions, one or two biopsy specimens were taken per lesion, compared with ≥three in international institutions. Conclusion There were some discrepancies between Japanese and international institutions for routine EGD. Thus, standardization is required for adequate risk assessment, proper techniques, and knowledge of endoscopic diagnosis of EGC.

BACKGROUND Multiple case reports suggest that olmesartan may be linked to sprue-like enteropathy; however, few epidemiological studies have examined this association and results have been mixed. AIM To assess whether olmesartan is associated with a higher rate of enteropathy vs other angiotensin II receptor blockers (ARBs). METHODS We conducted a cohort study among ARB initiators in 5 US claims databases representing different health insurance programmes. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for enteropathy-related outcomes, including coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy, comparing olmesartan initiators to initiators of other ARBs after propensity score (PS) matching. RESULTS We identified 1 928 469 eligible patients. The unadjusted incidence rates were 0.82, 1.41, 1.66 and 29.20 per 1000 person-years for coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy respectively. HRs after PS matching comparing olmesartan to other ARBs were 1.21 (95% CI, 1.05-1.40), 1.00 (95% CI, 0.88-1.13), 1.22 (95% CI, 1.10-1.36) and 1.04 (95% CI, 1.01-1.07) for each outcome. HRs were larger for patients aged 65 years and older (eg for coeliac disease, 1.57 [95% CI, 1.20-2.05]), for patients receiving treatment for more than 1 year (1.62 [95% CI, 1.24-2.12]), and for patients receiving higher cumulative olmesartan doses (1.78 [95% CI, 1.33-2.37]). CONCLUSIONS This large-scale, multi-database study found a higher rate of enteropathy in olmesartan initiators as compared to initiators of other ARBs, although the absolute incidence rate was low in both groups.

Background: Endoscopic radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality for early flat esophageal squamous cell neoplasms (ESCNs), but the risk factors for postoperative stricture have not been elucidated. The objective of this study was to identify and validate a predictor for post-RFA stenosis. Methods: We consecutively enrolled patients with flat-type ‘large’ (length no less than 3 cm extending no less than half the circumference of the esophagus), early ESCNs, treated with balloon-based RFA (12 J/cm2–clean–12 J/cm2 regimen). The tumor and technical factors for postoperative stricture were investigated and we validated the results externally with a society-based multicenter cohort using the same ablation regimen. Results: A total of 51 patients were enrolled (30 in the development set and 21 in the validation set). The complete remission rate at 12 months was 93%, and the rates of perforation and postoperative stenosis were 0% and 17%, respectively. Patients with post-RFA stenosis had a significantly larger longitudinal tumor size (mean 115 versus 61 mm, p = 0.003). There were no significant differences in age, body mass index, tumor circumferential extension, pretreatment histological grade, treatment efficacy or size of balloon catheter between the groups with or without stenosis. The optimal cut-off value was set as 9 cm to predict post-RFA stenosis by receiver operating characteristic curve [area under curve (AUC) = 0.881], which was then confirmed to be a reliable predictor by multivariate analysis (odds ratio, 12.7, 95% confidence interval, 1.18–136.28, p = 0.03) and have a good predictive performance in the validation set (AUC = 0.876). Conclusions: The most frequent adverse event of RFA was esophageal stenosis, for which the longitudinal tumor size was a significant predictive factor. Early intervention or prevention for stricture should be applied for those with long segment (⩾9 cm) ESCNs.