Large-Scale Whole-Genome Sequencing of Three Diverse Asian Populations in Singapore.

Underrepresentation of Asian genomes has hindered population and medical genetics research on Asians, leading to population disparities in precision medicine. By whole-genome sequencing of 4,810 Singapore Chinese, Malays, and Indians, we found 98.3 million SNPs and small insertions or deletions, over half of which are novel. Population structure analysis demonstrated great representation of Asian genetic diversity by three ethnicities in Singapore and revealed a Malay-related novel ancestry component. Furthermore, demographic inference suggested that Malays split from Chinese ∼24,800 years ago and experienced significant admixture with East Asians ∼1,700 years ago, coinciding with the Austronesian expansion. Additionally, we identified 20 candidate loci for natural selection, 14 of which harbored robust associations with complex traits and diseases. Finally, we show that our data can substantially improve genotype imputation in diverse Asian and Oceanian populations. These results highlight the value of our data as a resource to empower human genetics discovery across broad geographic regions.

AQP5 enriches for stem cells and cancer origins in the distal stomach.

LGR5 marks resident adult epithelial stem cells at the gland base in the mouse pyloric stomach1, but the identity of the equivalent human stem cell population remains unknown owing to a lack of surface markers that facilitate its prospective isolation and validation. In mouse models of intestinal cancer, LGR5+ intestinal stem cells are major sources of cancer following hyperactivation of the WNT pathway2. However, the contribution of pyloric LGR5+ stem cells to gastric cancer following dysregulation of the WNT pathway-a frequent event in gastric cancer in humans3-is unknown. Here we use comparative profiling of LGR5+ stem cell populations along the mouse gastrointestinal tract to identify, and then functionally validate, the membrane protein AQP5 as a marker that enriches for mouse and human adult pyloric stem cells. We show that stem cells within the AQP5+ compartment are a source of WNT-driven, invasive gastric cancer in vivo, using newly generated Aqp5-creERT2 mouse models. Additionally, tumour-resident AQP5+ cells can selectively initiate organoid growth in vitro, which indicates that this population contains potential cancer stem cells. In humans, AQP5 is frequently expressed in primary intestinal and diffuse subtypes of gastric cancer (and in metastases of these subtypes), and often displays altered cellular localization compared with healthy tissue. These newly identified markers and mouse models will be an invaluable resource for deciphering the early formation of gastric cancer, and for isolating and characterizing human-stomach stem cells as a prerequisite for harnessing the regenerative-medicine potential of these cells in the clinic.

Endothelial-immune crosstalk contributes to vasculopathy in nonalcoholic fatty liver disease.

The top cause of mortality in patients with nonalcoholic fatty liver disease (NAFLD) is cardiovascular complications. However, mechanisms of NAFLD-associated vasculopathy remain understudied. Here, we show that blood outgrowth endothelial cells (BOECs) from NAFLD subjects exhibit global transcriptional upregulation of chemokines and human leukocyte antigens. In mouse models of diet-induced NAFLD, we confirm heightened endothelial expressions of CXCL12 in the aortas and the liver vasculatures, and increased retention of infiltrated leukocytes within the vessel walls. To elucidate endothelial-immune crosstalk, we performed immunoprofiling by single-cell analysis, uncovering T cell intensification in NAFLD patients. Functionally, treatment with a CXCL12-neutralizing antibody is effective at moderating the enhanced chemotactic effect of NAFLD BOECs in recruiting CD8+ T lymphocytes. Interference with the CXCL12-CXCR4 axis using a CXCR4 antagonist also averts the impact of immune cell transendothelial migration and restores endothelial barrier integrity. Clinically, we detect threefold more circulating damaged endothelial cells in NAFLD patients than in healthy controls. Our work provides insight into the modulation of interactions with effector immune cells to mitigate endothelial injury in NAFLD.

Effectiveness of an Artificial Intelligence-Assisted App for Improving Eating Behaviors: Mixed Methods Evaluation.

BACKGROUND: A plethora of weight management apps are available, but many individuals, especially those living with overweight and obesity, still struggle to achieve adequate weight loss. An emerging area in weight management is the support for one's self-regulation over momentary eating impulses. OBJECTIVE: This study aims to examine the feasibility and effectiveness of a novel artificial intelligence-assisted weight management app in improving eating behaviors in a Southeast Asian cohort. METHODS: A single-group pretest-posttest study was conducted. Participants completed the 1-week run-in period of a 12-week app-based weight management program called the Eating Trigger-Response Inhibition Program (eTRIP). This self-monitoring system was built upon 3 main components, namely, (1) chatbot-based check-ins on eating lapse triggers, (2) food-based computer vision image recognition (system built based on local food items), and (3) automated time-based nudges and meal stopwatch. At every mealtime, participants were prompted to take a picture of their food items, which were identified by a computer vision image recognition technology, thereby triggering a set of chatbot-initiated questions on eating triggers such as who the users were eating with. Paired 2-sided t tests were used to compare the differences in the psychobehavioral constructs before and after the 7-day program, including overeating habits, snacking habits, consideration of future consequences, self-regulation of eating behaviors, anxiety, depression, and physical activity. Qualitative feedback were analyzed by content analysis according to 4 steps, namely, decontextualization, recontextualization, categorization, and compilation. RESULTS: The mean age, self-reported BMI, and waist circumference of the participants were 31.25 (SD 9.98) years, 28.86 (SD 7.02) kg/m2, and 92.60 (SD 18.24) cm, respectively. There were significant improvements in all the 7 psychobehavioral constructs, except for anxiety. After adjusting for multiple comparisons, statistically significant improvements were found for overeating habits (mean -0.32, SD 1.16; P<.001), snacking habits (mean -0.22, SD 1.12; P<.002), self-regulation of eating behavior (mean 0.08, SD 0.49; P=.007), depression (mean -0.12, SD 0.74; P=.007), and physical activity (mean 1288.60, SD 3055.20 metabolic equivalent task-min/day; P<.001). Forty-one participants reported skipping at least 1 meal (ie, breakfast, lunch, or dinner), summing to 578 (67.1%) of the 862 meals skipped. Of the 230 participants, 80 (34.8%) provided textual feedback that indicated satisfactory user experience with eTRIP. Four themes emerged, namely, (1) becoming more mindful of self-monitoring, (2) personalized reminders with prompts and chatbot, (3) food logging with image recognition, and (4) engaging with a simple, easy, and appealing user interface. The attrition rate was 8.4% (21/251). CONCLUSIONS: eTRIP is a feasible and effective weight management program to be tested in a larger population for its effectiveness and sustainability as a personalized weight management program for people with overweight and obesity. TRIAL REGISTRATION: ClinicalTrials.gov NCT04833803; https://classic.clinicaltrials.gov/ct2/show/NCT04833803.

Correction: Effectiveness of an Artificial Intelligence-Assisted App for Improving Eating Behaviors: Mixed Methods Evaluation.

[This corrects the article DOI: 10.2196/46036.].

A 10-year experience with anastomotic leaks in upper gastrointestinal surgery-Retrospective cohort study.

BACKGROUND: Anastomotic leak (AL) in upper gastrointestinal (UGI) surgery continues to be a diagnostic challenge. We seek to identify clinical parameters that predict AL and examine the effectiveness of investigations in evaluating AL following UGI surgeries. METHODS: 592 patients underwent UGI surgeries with an anastomosis between January 2011 and January 2021. Data on patient characteristics, surgery, postoperative investigations and outcomes were prospectively collected and analysed. RESULTS: The overall occurrence of AL was 6.4 %. Tachycardia >120 BPM (OR 6.959, 95 % CI 1.856-26.100, p = 0.004) and leukocyte count >19 × 109/L (OR 3.327, 95 % CI 1.009-10.967, p = 0.048) were independent predictors of AL. On multivariate analysis, patients whose anastomosis was deemed high risk and had pre-emptive investigation done postoperatively to exclude a leak were less likely to require intervention and were more likely to be managed conservatively (66.7 % vs 14.3 %, p = 0.025). Methylene blue test, oral contrast study and Computed Tomography scan with intravenous and oral contrast had 50.0 %, 20.0 % and 9.1 % false negative results, while esophagogastroduodenoscopy had none. There was no misdiagnosed AL when more than 1 investigation (n = 15, 39.5 %) were performed. CONCLUSION: Our study demonstrates that the presence of a triad including desaturation, tachycardia and leucocytosis predicts for AL following UGI surgery and for confirmation of a leak, evaluation with 2 or more investigation is needed. A practice of evaluating high risk anastomosis prior to commencement of feeding decreased the need for surgical intervention and improves success of conservative treatment.

Clinical relevance of PD-1 positive CD8 T-cells in gastric cancer.

BACKGROUND: We evaluated the relevance of PD-1+CD8+ T-cells in gastric cancer (GC) including prognostic significance, association with chemotherapy and immunotherapy sensitivity and correlations with the tumor microenvironment (TME). METHODS: Discovery cohort: GC samples were evaluated for AE1/3, CD8, PD-1, Ki-67 and Granzyme-B expression with fluorescence-based multiplex immunohistochemistry (mIHC). Validation cohorts: we analyzed bulk RNAseq GC datasets from TCGA, the "3G" chemotherapy trial and an immunotherapy phase 2 trial. The cox proportional hazards model was used to identify factors that influenced overall survival (OS). To study the TME, we analyzed single-cell RNAseq performed on GCs. RESULTS: In the discovery cohort of 350 GCs, increased PD-1 expression of CD8 T-cells was prognostic for OS (HR 0.822, p = 0.042). PD-1 expression in CD8 T-cells highly correlated with cytolytic [Granzyme-B+] (r = 0.714, p < 0.001) and proliferative [Ki-67+] (r = 0.798, p < 0.001) activity. Analysis of bulk RNAseq datasets showed tumors with high PD-1 and CD8A expression levels had improved OS when treated with immunotherapy (HR 0.117, p = 0.036) and chemotherapy (HR 0.475, p = 0.017). Analysis of an scRNAseq dataset of 152,423 cells from 40 GCs revealed that T-cell and NK-cell proportions were higher (24% vs 18% and 19% vs 15%, p < 0.0001), while macrophage proportions were lower (7% vs 11%, p < 0.0001) in CD8PD-1high compared to CD8PD-1low tumors. CONCLUSION: This is one of the largest GC cohorts of mIHC combined with analysis of multiple datasets providing orthogonal validation of the clinical relevance of PD-1+CD8+ T-cells being associated with improved OS. CD8PD-1high tumors have distinct features of an immunologically active, T-cell inflamed TME.

Best practice approach for redo-surgeries after sleeve gastrectomy, an expert's modified Delphi consensus.

BACKGROUND: Sleeve gastrectomy (SG) is the most common metabolic and bariatric surgical (MBS) procedure worldwide. Despite the desired effect of SG on weight loss and remission of obesity-associated medical problems, there are some concerns regarding the need to do revisional/conversional surgeries after SG. This study aims to make an algorithmic clinical approach based on an expert-modified Delphi consensus regarding redo-surgeries after SG, to give bariatric and metabolic surgeons a guideline that might help for the best clinical decision. METHODS: Forty-six recognized bariatric and metabolic surgeons from 25 different countries participated in this Delphi consensus study in two rounds to develop a consensus on redo-surgeries after SG. An agreement/disagreement ≥ 70.0% on statements was considered to indicate a consensus. RESULTS: Consensus was reached for 62 of 72 statements and experts did not achieve consensus on 10 statements after two rounds of online voting. Most of the experts believed that multi-disciplinary team evaluation should be done in all redo-procedures after SG and there should be at least 12 months of medical and supportive management before performing redo-surgeries after SG for insufficient weight loss, weight regain, and gastroesophageal reflux disease (GERD). Also, experts agreed that in case of symptomatic GERD in the presence of adequate weight loss, medical treatment for at least 1 to 2 years is an acceptable option and agreed that Roux-en Y gastric bypass is an appropriate option in this situation. There was disagreement consensus on efficacy of omentopexy in rotation and efficacy of fundoplication in the presence of a dilated fundus and GERD. CONCLUSION: Redo-surgeries after SG is still an important issue among bariatric and metabolic surgeons. The proper time and procedure selection for redo-surgery need careful considerations. Although multi-disciplinary team evaluation plays a key role to evaluate best options in these situations, an algorithmic clinical approach based on the expert's consensus as a guideline can help for the best clinical decision-making.

Single-incision transgastric resection for gastric gastrointestinal stromal tumors in anatomically challenging locations.

Surgical resection is the mainstay treatment for resectable gastrointestinal stromal tumors (GISTs). However, resection in anatomically challenging locations, such as near the gastroesophageal junction, lesser curve and fundus, remain technically challenging. We herein report the outcomes of the largest series of patients who underwent single-incision transgastric resection of an intraluminal gastric GIST. Our reduced-port resection technique for intraluminal GISTs in these anatomically challenging locations involves a single incision in the left hypochondrium, deepened to access the gastric lumen, with the surgery completed in a transgastric manner. A total of 22 patients received surgery with this technique at the National University Hospital in Singapore from November 2012 to September 2020. The median operative time was 101 (range 50-253) min, with no conversions to open surgery, median lesion size 3.6 (range 1.8-8.2) cm and median postoperative length of stay 5 (range 1-13) days. There was no 30-day mortality and no recurrence during the follow-up period. Our laparoscopic approach for reduced-port transgastric excision of intraluminal GISTs allows for adequate surgical clearance, convenient extraction and secure gastrostomy closure with low morbidity.

Association of metabolic-bariatric surgery with long-term survival in adults with and without diabetes: a one-stage meta-analysis of matched cohort and prospective controlled studies with 174 772 participants.

BACKGROUND: Metabolic-bariatric surgery delivers substantial weight loss and can induce remission or improvement of obesity-related risks and complications. However, more robust estimates of its effect on long-term mortality and life expectancy-especially stratified by pre-existing diabetes status-are needed to guide policy and facilitate patient counselling. We compared long-term survival outcomes of severely obese patients who received metabolic-bariatric surgery versus usual care. METHODS: We did a prespecified one-stage meta-analysis using patient-level survival data reconstructed from prospective controlled trials and high-quality matched cohort studies. We searched PubMed, Scopus, and MEDLINE (via Ovid) for randomised trials, prospective controlled studies, and matched cohort studies comparing all-cause mortality after metabolic-bariatric surgery versus non-surgical management of obesity published between inception and Feb 3, 2021. We also searched grey literature by reviewing bibliographies of included studies as well as review articles. Shared-frailty (ie, random-effects) and stratified Cox models were fitted to compare all-cause mortality of adults with obesity who underwent metabolic-bariatric surgery compared with matched controls who received usual care, taking into account clustering of participants at the study level. We also computed numbers needed to treat, and extrapolated life expectancy using Gompertz proportional-hazards modelling. The study protocol is prospectively registered on PROSPERO, number CRD42020218472. FINDINGS: Among 1470 articles identified, 16 matched cohort studies and one prospective controlled trial were included in the analysis. 7712 deaths occurred during 1·2 million patient-years. In the overall population consisting 174 772 participants, metabolic-bariatric surgery was associated with a reduction in hazard rate of death of 49·2% (95% CI 46·3-51·9, p<0·0001) and median life expectancy was 6·1 years (95% CI 5·2-6·9) longer than usual care. In subgroup analyses, both individuals with (hazard ratio 0·409, 95% CI 0·370-0·453, p<0·0001) or without (0·704, 0·588-0·843, p<0·0001) baseline diabetes who underwent metabolic-bariatric surgery had lower rates of all-cause mortality, but the treatment effect was considerably greater for those with diabetes (between-subgroup I2 95·7%, p<0·0001). Median life expectancy was 9·3 years (95% CI 7·1-11·8) longer for patients with diabetes in the surgery group than the non-surgical group, whereas the life expectancy gain was 5·1 years (2·0-9·3) for patients without diabetes. The numbers needed to treat to prevent one additional death over a 10-year time frame were 8·4 (95% CI 7·8-9·1) for adults with diabetes and 29·8 (21·2-56·8) for those without diabetes. Treatment effects did not appear to differ between gastric bypass, banding, and sleeve gastrectomy (I2 3·4%, p=0·36). By leveraging the results of this meta-analysis and other published data, we estimated that every 1·0% increase in metabolic-bariatric surgery utilisation rates among the global pool of metabolic-bariatric candidates with and without diabetes could yield 5·1 million and 6·6 million potential life-years, respectively. INTERPRETATION: Among adults with obesity, metabolic-bariatric surgery is associated with substantially lower all-cause mortality rates and longer life expectancy than usual obesity management. Survival benefits are much more pronounced for people with pre-existing diabetes than those without. FUNDING: None.

Induction of Gastric Cancer by Successive Oncogenic Activation in the Corpus.

BACKGROUND & AIMS: Metaplasia and dysplasia in the corpus are reportedly derived from de-differentiation of chief cells. However, the cellular origin of metaplasia and cancer remained uncertain. Therefore, we investigated whether pepsinogen C (PGC) transcript-expressing cells represent the cellular origin of metaplasia and cancer using a novel Pgc-specific CreERT2 recombinase mouse model. METHODS: We generated a Pgc-mCherry-IRES-CreERT2 (Pgc-CreERT2) knock-in mouse model. Pgc-CreERT2/+ and Rosa-EYFP mice were crossed to generate Pgc-CreERT2/Rosa-EYFP (Pgc-CreERT2/YFP) mice. Gastric tissues were collected, followed by lineage-tracing experiments and histologic and immunofluorescence staining. We further established Pgc-CreERT2;KrasG12D/+ mice and investigated whether PGC transcript-expressing cells are responsible for the precancerous state in gastric glands. To investigate cancer development from PGC transcript-expressing cells with activated Kras, inactivated Apc, and Trp53 signaling pathways, we crossed Pgc-CreERT2/+ mice with conditional KrasG12D, Apcflox, Trp53flox mice. RESULTS: Expectedly, mCherry mainly labeled chief cells in the Pgc-CreERT2 mice. However, mCherry was also detected throughout the neck cell and isthmal stem/progenitor regions, albeit at lower levels. In the Pgc-CreERT2;KrasG12D/+ mice, PGC transcript-expressing cells with KrasG12D/+ mutation presented pseudopyloric metaplasia. The early induction of proliferation at the isthmus may reflect the ability of isthmal progenitors to react rapidly to Pgc-driven KrasG12D/+ oncogenic mutation. Furthermore, Pgc-CreERT2;KrasG12D/+;Apcflox/flox mice presented intramucosal dysplasia/carcinoma and Pgc-CreERT2;KrasG12D/+;Apcflox/flox;Trp53flox/flox mice presented invasive and metastatic gastric carcinoma. CONCLUSIONS: The Pgc-CreERT2 knock-in mouse is an invaluable tool to study the effects of successive oncogenic activation in the mouse corpus. Time-course observations can be made regarding the responses of isthmal and chief cells to oncogenic insults. We can observe stomach-specific tumorigenesis from the beginning to metastatic development.

Outcomes of a Phase II Study of Intraperitoneal Paclitaxel plus Systemic Capecitabine and Oxaliplatin (XELOX) for Gastric Cancer with Peritoneal Metastases.

BACKGROUND: Adding intraperitoneal paclitaxel (IP-PTX) to paclitaxel/5-fluoropyrimidine has shown promising results in patients with gastric cancer peritoneal metastases (GCPM) but has not been studied with standard-of-care platinum/fluoropyrimidine combinations. Our goal to was evaluate IP-PTX with capecitabine/oxaliplatin (XELOX) in GCPM. METHODS: Forty-four patients with GCPM received IP PTX (40 mg/m2, Days 1, 8), oral capecitabine (1000 mg/m2 twice daily, Days 1-14) and intravenous oxaliplatin (100 mg/m2, Day 1) in 21-day cycles. Patients with synchronous GCPM underwent conversion surgery if they had good response after chemotherapy, conversion to negative cytology, no extraperitoneal metastasis, and no peritoneal disease during surgery. The primary endpoint was overall survival and secondary endpoints were progression-free survival and safety. Outcomes from the trial were compared against a matched cohort of 39 GCPM patients who received systemic chemotherapy (SC) comprising platinum/fluoropyrimidine. RESULTS: The median OS for the IP and SC groups was 14.6 and 10.6 months (hazard ratio [HR] 0.44; 95% confidence interval [CI], 0.26-0.74; p = 0.002). The median PFS for the IP and SC group was 9.5 and 4.4 months respectively (HR 0.39; 95% CI 0.25-0.66; p < 0.001). Patients in the SC group were younger (IP vs. SC, 61 vs. 56 years, p = 0.021) and had better performance status (ECOG 0, IP vs. SC, 47.7% vs. 76.9%, p = 0.007) compared with the IP cohort. In IP group, conversion surgery was performed in 36.1% (13/36) of patients, with a median OS of 24.2 (95% CI 13.1-35.3) months and 1-year OS of 84.6%. CONCLUSIONS: IP PTX with XELOX is a promising treatment option for GCPM patients. In patients with good response, conversion surgery was feasible with favourable outcomes.

Gastro-esophageal reflux disease (GERD) after peroral endoscopic myotomy (POEM).

BACKGROUND: Peroral endoscopic myotomy (POEM) is gaining traction as a minimally invasive treatment of achalasia. Increased reflux is reported after POEM but the incidence, type and severity of reflux are not fully understood. We aimed to study the prevalence and nature of reflux after POEM and correlate reflux with endoscopy and pH-impedance findings. METHODS: This is a prospective cohort study of achalasia patients undergoing POEM since 2014. Data from Eckardt and GERD symptom scores, high-resolution oesophageal manometry (HRM) and gastroscopy were performed pre-procedure and repeated at 1-year follow-up. Data from 24-h pH-impedance, if performed, were also recorded. A standardized questionnaire was used to determine the severity and frequency of heartburn symptoms and the composite score for each patient was calculated. RESULTS: 58 patients underwent POEM between January 2014 and October 2018. The efficacy of POEM at 1 year was 93.0%. We observed reduction of median Integrated Relaxation Pressure (IRP) from 23.5 ± 33.1 mmHg to 13.4 ± 7.71 mmHg (p = 0.005) and mean Eckardt score improved from 6.09 ± 2.43 points to 1.16 ± 1.70 points (p < 0.001). At 1 year, 43.1% (n = 25) had symptomatic reflux. Of the 40 patients who underwent repeated gastroscopy, 60.0% (n = 24) had endoscopic evidence of oesophagitis with seven patients (18%) diagnosed with Grade C or D oesophagitis. 43.1% (n = 25) of patients had pH-impedance done post-POEM off PPIs. 14 patients (56%) had increased acid exposure. Sixteen percent of reflux episodes were acidic and 77.3% were weakly acidic. CONCLUSION: POEM was an effective treatment for achalasia. However, GERD was common after POEM with incidence of 43% on symptom score, 60% on endoscopy and 56% on pH-impedance test. Post-POEM reflux appeared to be predominantly acidic in nature. Routine surveillance for GERD after POEM is recommended.

Personal motivation, self-regulation barriers and strategies for weight loss in people with overweight and obesity: a thematic framework analysis.

OBJECTIVE: To explore motivations, self-regulation barriers and strategies in a multi-ethnic Southeast Asian population with overweight and obesity. DESIGN: Qualitative design using semi-structured face-to-face and videoconferencing interviews. Data were analysed using thematic framework analysis and constant comparison method. SETTING: Specialist weight management clinic. PARTICIPANTS: Twenty-two participants were purposively sampled from 13 April to 30 April 2021. Median age and BMI of the participants were 37·5 (interquartile range (IQR) = 13·3) and 39·2 kg/m2 (IQR = 6·1), respectively. And 31·8 % were men, majority had a high intention to adopt healthy eating behaviours (median = 6·5; IQR = 4·8-6·3) and 59 % of the participants had a medium level of self-regulation. RESULTS: Six themes and fifteen subthemes were derived. Participants were motivated to lose weight by the sense of responsibility as the family's pillar of support and to feel 'normal' again. We coupled self-regulation barriers with corresponding strategies to come up with four broad themes: habitual overconsumption - mindful self-discipline; proximity and convenience of food available - mental tenacity; momentary lack of motivation and sense of control - motivational boosters; and overeating triggers - removing triggers. We highlighted six unique overeating triggers namely: trigger activities (e.g. using social media); eating with family, friends and colleagues; provision of food by someone; emotions (e.g. feeling bored at home, sad and stressed); physiological condition (e.g. premenstrual syndrome); and the time of the day. CONCLUSIONS: Future weight management interventions should consider encompassing participant-led weight loss planning, motivation boosters and self-regulation skills to cope with momentary overeating triggers.

Development and validation of a serum microRNA biomarker panel for detecting gastric cancer in a high-risk population.

OBJECTIVE: An unmet need exists for a non-invasive biomarker assay to aid gastric cancer diagnosis. We aimed to develop a serum microRNA (miRNA) panel for identifying patients with all stages of gastric cancer from a high-risk population. DESIGN: We conducted a three-phase, multicentre study comprising 5248 subjects from Singapore and Korea. Biomarker discovery and verification phases were done through comprehensive serum miRNA profiling and multivariant analysis of 578 miRNA candidates in retrospective cohorts of 682 subjects. A clinical assay was developed and validated in a prospective cohort of 4566 symptomatic subjects who underwent endoscopy. Assay performance was confirmed with histological diagnosis and compared with Helicobacter pylori (HP) serology, serum pepsinogens (PGs), 'ABC' method, carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9). Cost-effectiveness was analysed using a Markov decision model. RESULTS: We developed a clinical assay for detection of gastric cancer based on a 12-miRNA biomarker panel. The 12-miRNA panel had area under the curve (AUC)=0.93 (95% CI 0.90 to 0.95) and AUC=0.92 (95% CI 0.88 to 0.96) in the discovery and verification cohorts, respectively. In the prospective study, overall sensitivity was 87.0% (95% CI 79.4% to 92.5%) at specificity of 68.4% (95% CI 67.0% to 69.8%). AUC was 0.848 (95% CI 0.81 to 0.88), higher than HP serology (0.635), PG 1/2 ratio (0.641), PG index (0.576), ABC method (0.647), CEA (0.576) and CA19-9 (0.595). The number needed to screen is 489 annually. It is cost-effective for mass screening relative to current practice (incremental cost-effectiveness ratio=US$44 531/quality-of-life year). CONCLUSION: We developed and validated a serum 12-miRNA biomarker assay, which may be a cost-effective risk assessment for gastric cancer. TRIAL REGISTRATION NUMBER: This study is registered with ClinicalTrials.gov (Registration number: NCT04329299).

Human Pluripotent Stem Cell-Derived Organoids as Models of Liver Disease.

BACKGROUND & AIMS: There are few in vitro models for studying the 3-dimensional interactions among different liver cell types during organogenesis or disease development. We aimed to generate hepatic organoids that comprise different parenchymal liver cell types and have structural features of the liver, using human pluripotent stem cells. METHODS: We cultured H1 human embryonic stem cells (WA-01, passage 27-40) and induced pluripotent stem cells (GM23338) with a series of chemically defined and serum-free media to induce formation of posterior foregut cells, which were differentiated in 3 dimensions into hepatic endoderm spheroids and stepwise into hepatoblast spheroids. Hepatoblast spheroids were reseeded in a high-throughput format and induced to form hepatic organoids; development of functional bile canaliculi was imaged live. Levels of albumin and apolipoprotein B were measured in cell culture supernatants using an enzyme-linked immunosorbent assay. Levels of gamma glutamyl transferase and alkaline phosphatase were measured in cholangiocytes. Organoids were incubated with troglitazone for varying periods and bile transport and accumulation were visualized by live-imaging microscopy. Organoids were incubated with oleic and palmitic acid, and formation of lipid droplets was visualized by staining. We compared gene expression profiles of organoids incubated with free fatty acids or without. We also compared gene expression profiles between liver tissue samples from patients with nonalcoholic steatohepatitis (NASH) versus without. We quantified hepatocyte and cholangiocyte populations in organoids using immunostaining and flow cytometry; cholangiocyte proliferation of cholangiocytes was measured. We compared the bile canaliculi network in the organoids incubated with versus without free fatty acids by live imaging. RESULTS: Cells in organoids differentiated into hepatocytes and cholangiocytes, based on the expression of albumin and cytokeratin 7. Hepatocytes were functional, based on secretion of albumin and apolipoprotein B and cytochrome P450 activity; cholangiocytes were functional, based on gamma glutamyl transferase and alkaline phosphatase activity and proliferative responses to secretin. The organoids organized a functional bile canaliculi system, which was disrupted by cholestasis-inducing drugs such as troglitazone. Organoids incubated with free fatty acids had gene expression signatures similar to those of liver tissues from patients with NASH. Incubation of organoids with free fatty acid-enriched media resulted in structural changes associated with nonalcoholic fatty liver disease, such as decay of bile canaliculi network and ductular reactions. CONCLUSIONS: We developed a hepatic organoid platform with human cells that can be used to model complex liver diseases, including NASH.

Plasma Clearance of B-Type Natriuretic Peptide (BNP) before and after Bariatric Surgery for Morbid Obesity.

BACKGROUND: Obese patients have lower plasma concentrations of the cardiac natriuretic peptides (NPs) than their age- and sex-matched counterparts. This may reflect lower production and/or increased peptide clearance. It is unclear whether NP bioactivity is affected by obesity. METHODS: We studied the effects of obesity on B-type natriuretic peptide (BNP) clearance and bioactivity by comparing results from standardized intravenous infusions of BNP administered 2 weeks before and 6 months after bariatric surgery in 12 consecutive patients with morbid obesity (body mass index, BMI > 35 kg/m2). Anthropometric, clinical, neurohormonal, renal, and echocardiographic variables were obtained pre- and postsurgery. Pre- vs postsurgery calculated intrainfusion peptide clearances were compared. RESULTS: BMI (44.3 ± 5.0 vs 33.9 ± 5.2 kg/m2, P < 0.001) and waist circumference (130.3 ± 11.9 vs 107.5 ± 14.7 cm, P < 0.001) decreased substantially after bariatric surgery. Calculated plasma clearance of BNP was reduced (approximately 30%) after surgery. Though not controlled for, sodium intake was presumably lower after bariatric surgery. Despite this, preinfusion endogenous plasma NP concentrations did not significantly differ between pre- and postsurgery studies. The ratio of plasma N-terminal (NT)-proBNP to 24 h urine sodium excretion was higher postsurgery (P = 0.046; with similar nonsignificant findings for BNP, atrial NP (ANP) and NT-proANP), indicating increased circulating NPs for a given sodium status. Mean plasma NP concentrations for given calculated end-systolic wall stress and cardiac filling pressures (as assessed by echocardiographic E/e') rose slightly, but not significantly postsurgery. Second messenger, hemodynamic, renal, and neurohormonal responses to BNP were not altered between studies. CONCLUSION: Obesity is associated with increased clearance, but preserved bioactivity, of BNP.

Opportunistic upper endoscopy during colonoscopy as a screening strategy for countries with intermediate gastric cancer risk.

BACKGROUND AND AIM: Screening upper endoscopy can detect esophagogastric (OG) cancers early with improved outcomes. Recent cost-utility studies suggest that opportunistic upper endoscopy at the same setting of colonoscopy might be a useful strategy for screening of OG cancers, and it may be more acceptable to the patients due to cost-saving and convenience. We aim to study the diagnostic performance of this screening strategy in a country with intermediate gastric cancer risk. METHODS: A retrospective cohort study using a prospective endoscopy database from 2015 to 2017 was performed. Patients included were individuals age > 40 who underwent opportunistic upper endoscopy at the same setting of colonoscopy without any OG symptoms. Neoplastic OG lesions are defined as cancer and high-grade dysplasia. Pre-neoplastic lesions include Barrett's esophagus (BE), intestinal metaplasia (IM), and atrophic gastritis (AG). RESULTS: The study population involved 1414 patients. Neoplastic OG lesions were detected in five patients (0.35%). Pre-neoplastic lesions were identified in 174 (12.3%) patients. IM was found in 146 (10.3%) patients with 21 (1.4%) having extensive IM. The number needed to scope to detect a neoplastic OG lesion is 282.8 with an estimated cost of USD$141 400 per lesion detected. On multivariate regression, age ≥ 60 (RR: 1.84, 95% CI: 1.29-2.63) and first-degree relatives with gastric cancer (RR: 1.64, 95% CI: 1.06-2.55) were independent risk factors for neoplastic or pre-neoplastic OG lesion. CONCLUSION: For countries with intermediate gastric cancer risk, opportunistic upper endoscopy may be an alternative screening strategy in a selected patient population. Prospective trials are warranted to validate its performance.

The first modified Delphi consensus statement on sleeve gastrectomy.

INTRODUCTION: Sleeve gastrectomy (SG) is the commonest bariatric procedure worldwide. Yet there is significant variation in practice concerning its various aspects. This paper report results from the first modified Delphi consensus-building exercise on SG. METHODS: We established a committee of 54 globally recognized opinion makers in this field. The committee agreed to vote on several statements concerning SG. An agreement or disagreement amongst ≥ 70.0% experts was construed as a consensus. RESULTS: The committee achieved a consensus of agreement (n = 71) or disagreement (n = 7) for 78 out of 97 proposed statements after two rounds of voting. The committee agreed with 96.3% consensus that the characterization of SG as a purely restrictive procedure was inaccurate and there was 88.7% consensus that SG was not a suitable standalone, primary, surgical weight loss option for patients with Barrett's esophagus (BE) without dysplasia. There was an overwhelming consensus of 92.5% that the sleeve should be fashioned over an orogastric tube of 36-40 Fr and a 90.7% consensus that surgeons should stay at least 1 cm away from the angle of His. Remarkably, the committee agreed with 81.1% consensus that SG patients should undergo a screening endoscopy every 5 years after surgery to screen for BE. CONCLUSION: A multinational team of experts achieved consensus on several aspects of SG. The findings of this exercise should help improve the outcomes of SG, the commonest bariatric procedure worldwide, and guide future research on this topic.

Fat storage-inducing transmembrane protein 2 (FIT2) is less abundant in type 2 diabetes, and regulates triglyceride accumulation and insulin sensitivity in adipocytes.

Fat storage-inducing transmembrane protein 2 (FIT2) aids in partitioning of cellular triacylglycerol into lipid droplets. A genome-wide association study reported FITM2-R3H domain containing like-HNF4A locus to be associated with type 2 diabetes (T2DM) in East Asian populations. Mice with adipose tissue (AT)-specific FIT2 knockout exhibited lipodystrophic features, with reduced AT mass, insulin resistance, and greater inflammation in AT when fed a high-fat diet. The role of FIT2 in regulating human adipocyte function is not known. Here, we found FIT2 protein abundance is lower in subcutaneous and omental AT obtained from patients with T2DM compared with nondiabetic control subjects. Partial loss of FIT2 protein in primary human adipocytes attenuated their lipid storage capacity and induced insulin resistance. After palmitate treatment, triacylglycerol accumulation, insulin-induced Akt (Ser-473) phosphorylation, and insulin-stimulated glucose uptake were significantly reduced in FIT2 knockdown adipocytes compared with control cells. Gene expression of proinflammatory cytokines IL-18 and IL-6 and phosphorylation of the endoplasmic reticulum stress marker inositol-requiring enzyme 1α were greater in FIT2 knockdown adipocytes than in control cells. Our results show for the first time that FIT2 is associated with T2DM in humans and plays an integral role in maintaining metabolically healthy AT function.-Agrawal, M., Yeo, C. R., Shabbir, A., Chhay, V., Silver, D. L., Magkos, F., Vidal-Puig, A., Toh, S.-A. Fat storage-inducing transmembrane protein 2 (FIT2) is less abundant in type 2 diabetes, and regulates triglyceride accumulation and insulin sensitivity in adipocytes.