Boltzmann Model Predicts Glycan Structures from Lectin Binding.

Glycans are complex oligosaccharides that are involved in many diseases and biological processes. Unfortunately, current methods for determining glycan composition and structure (glycan sequencing) are laborious and require a high level of expertise. Here, we assess the feasibility of sequencing glycans based on their lectin binding fingerprints. By training a Boltzmann model on lectin binding data, we predict the approximate structures of 88 ± 7% of N-glycans and 87 ± 13% of O-glycans in our test set. We show that our model generalizes well to the pharmaceutically relevant case of Chinese hamster ovary (CHO) cell glycans. We also analyze the motif specificity of a wide array of lectins and identify the most and least predictive lectins and glycan features. These results could help streamline glycoprotein research and be of use to anyone using lectins for glycobiology.

LipidSIM: Inferring mechanistic lipid biosynthesis perturbations from lipidomics with a flexible, low-parameter, Markov modeling framework.

Lipid metabolism is a complex and dynamic system involving numerous enzymes at the junction of multiple metabolic pathways. Disruption of these pathways leads to systematic dyslipidemia, a hallmark of many pathological developments, such as nonalcoholic steatohepatitis and diabetes. Recent advances in computational tools can provide insights into the dysregulation of lipid biosynthesis, but limitations remain due to the complexity of lipidomic data, limited knowledge of interactions among involved enzymes, and technical challenges in standardizing across different lipid types. Here, we present a low-parameter, biologically interpretable framework named Lipid Synthesis Investigative Markov model (LipidSIM), which models and predicts the source of perturbations in lipid biosynthesis from lipidomic data. LipidSIM achieves this by accounting for the interdependency between the lipid species via the lipid biosynthesis network and generates testable hypotheses regarding changes in lipid biosynthetic reactions. This feature allows the integration of lipidomics with other omics types, such as transcriptomics, to elucidate the direct driving mechanisms of altered lipidomes due to treatments or disease progression. To demonstrate the value of LipidSIM, we first applied it to hepatic lipidomics following Keap1 knockdown and found that changes in mRNA expression of the lipid pathways were consistent with the LipidSIM-predicted fluxes. Second, we used it to study lipidomic changes following intraperitoneal injection of CCl4 to induce fast NAFLD/NASH development and the progression of fibrosis and hepatic cancer. Finally, to show the power of LipidSIM for classifying samples with dyslipidemia, we used a Dgat2-knockdown study dataset. Thus, we show that as it demands no a priori knowledge of enzyme kinetics, LipidSIM is a valuable and intuitive framework for extracting biological insights from complex lipidomic data.

A predictive ensemble classifier for the gene expression diagnosis of ASD at ages 1 to 4 years.

Autism Spectrum Disorder (ASD) diagnosis remains behavior-based and the median age of diagnosis is ~52 months, nearly 5 years after its first-trimester origin. Accurate and clinically-translatable early-age diagnostics do not exist due to ASD genetic and clinical heterogeneity. Here we collected clinical, diagnostic, and leukocyte RNA data from 240 ASD and typically developing (TD) toddlers (175 toddlers for training and 65 for test). To identify gene expression ASD diagnostic classifiers, we developed 42,840 models composed of 3570 gene expression feature selection sets and 12 classification methods. We found that 742 models had AUC-ROC ≥ 0.8 on both Training and Test sets. Weighted Bayesian model averaging of these 742 models yielded an ensemble classifier model with accurate performance in Training and Test gene expression datasets with ASD diagnostic classification AUC-ROC scores of 85-89% and AUC-PR scores of 84-92%. ASD toddlers with ensemble scores above and below the overall ASD ensemble mean of 0.723 (on a scale of 0 to 1) had similar diagnostic and psychometric scores, but those below this ASD ensemble mean had more prenatal risk events than TD toddlers. Ensemble model feature genes were involved in cell cycle, inflammation/immune response, transcriptional gene regulation, cytokine response, and PI3K-AKT, RAS and Wnt signaling pathways. We additionally collected targeted DNA sequencing smMIPs data on a subset of ASD risk genes from 217 of the 240 ASD and TD toddlers. This DNA sequencing found about the same percentage of SFARI Level 1 and 2 ASD risk gene mutations in TD (12 of 105) as in ASD (13 of 112) toddlers, and classification based only on the presence of mutation in these risk genes performed at a chance level of 49%. By contrast, the leukocyte ensemble gene expression classifier correctly diagnostically classified 88% of TD and ASD toddlers with ASD risk gene mutations. Our ensemble ASD gene expression classifier is diagnostically predictive and replicable across different toddler ages, races, and ethnicities; out-performs a risk gene mutation classifier; and has potential for clinical translation.

Randomized trial of gastric and colorectal endoscopic submucosal dissection defect closure comparing a novel through-the-scope suturing system with an over-the-scope suturing system (with video).

BACKGROUND AND AIMS: Mucosal closure adds time but reduces adverse events associated with endoscopic submucosal dissection (ESD). We aimed to assess the closure time (CT), technical success, and cost-effectiveness between a novel through-the-scope helix tack suture system (TTSS) and the over-the-scope suturing system (OTSS). METHODS: In this single-center, prospective, randomized trial, all patients undergoing ESD with anticipated closure were randomized 1:1 to TTSS (study group) or OTSS (control group). Primary outcomes were CT and overall CT (OCT; CT + setup time). Secondary outcomes were rates of technical success, adverse events, and cost-effectiveness. RESULTS: Forty patients were randomized to OTSS (n = 20) or TTSS (n = 20). OTSS and TTSS groups were similar with respect to age, gender, proportion of colorectal polyps, proximal colon polyps, and mean size of the resected specimen (40.9 mm vs 40.4 mm). The mean CT was 18.4 minutes for OTSS and 23.3 minutes for TTSS (P = .36). The mean OCT was 32 minutes for OTSS and 39.5 minutes for TTSS (P = .36). Closure with a primary device was successful in 17 cases (85%) with OTSS and 18 cases (90%) with TTSS (P = .63). No closure-related intraprocedural adverse events or delayed perforations were noted. Mean cost of closure was significantly lower in the TTSS group for lesions <35 mm (P = .008). CONCLUSIONS: TTSS was not found to be superior to OTSS with respect to CT and technical and clinical success for closure of gastric and colorectal ESD defects. TTSS is more cost-effective for closure of lesions <35 mm. (Clinical trial registration number: NCT04925271.).

Colonic-enteric lumen-apposing metal stents: a promising and safe alternative for endoscopic management of small-bowel obstruction.

BACKGROUND AND AIMS: Lumen-apposing metal stents (LAMSs) have revolutionized the treatment of various gastroenterologic conditions that previously required surgery. The use of LAMSs for the management of small-bowel obstruction (SBO) involves EUS-guided coloenterostomy (EUS-CE) between the colon and a dilated loop of the small intestine proximal to the point of obstruction. This procedure is potentially beneficial for patients with malignant SBO who are poor surgical candidates. METHODS: A retrospective cohort study was conducted at 2 tertiary care hospitals. Patients who underwent EUS-CE for SBO were identified, and data regarding patient demographics, indication for the procedure, location of the obstruction, procedural details, and adverse events were collected. The primary outcome was technical success of the procedure. Secondary outcomes were clinical success, resolution of symptoms, ability to tolerate enteral nutrition, and adverse events. RESULTS: Twenty-six patients who underwent the EUS-CE procedure were included. Technical success was achieved in all 26 patients, clinical success (resolution of obstructive symptoms) was achieved in 92.3% of patients (24/26), and the ability to resume enteral nutrition in 84.6% (22/26). Adverse events occurred in 4 patients (15.4%) and included bleeding (1/26), diarrhea (2/26), and postprocedure sepsis (1/26). Patients were followed for a mean of 54.8 days (range, 2-190). CONCLUSIONS: This study highlights that EUS-CE with LAMSs can be performed with high technical and clinical success for the management of SBO, particularly in patients with malignant obstructions who are not suitable candidates for surgical interventions. Further research with larger sample sizes will be essential to substantiate its efficacy and safety.

Safety, Efficacy and Clinical Utility of the 5.1mm EndoRotor Powered Debridement Catheter for Treatment of Walled-Off Pancreatic Necrosis.

BACKGROUND AND AIMS: Direct endoscopic necrosectomy (DEN) is a recommended strategy for treatment of walled-off-necrosis (WON). DEN uses a variety of devices including the EndoRotor (Interscope, Inc.) debridement catheter. Recently, a 5.1 mm EndoRotor with increased chamber size and rate of tissue removal was introduced. The aim of this study was to assess the efficacy and safety of this device. METHODS: A multi-center cohort study was conducted at eight institutions including patients who underwent DEN with the 5.1 mm EndoRotor. The primary outcome was the number of DEN sessions needed for WON resolution. Secondary outcomes included the average percent reduction in solid WON debris and decrease in WON area per session, total time spent performing EndoRotor therapy for WON resolution, and adverse events. RESULTS: 64 procedures in 41 patients were included. For patients in which the 5.1 mm EndoRotor catheter was the sole therapeutic modality, an average of 1.6 DEN sessions resulted in WON resolution with an average cumulative time of 85.5 minutes. Of the 21 procedures with data regarding percent of solid debris, the average reduction was 85% +/- 23% per session. Of the 19 procedures with data regarding WON area, the mean area significantly decreased from 97.6 +/- 72.0 cm2 to 27.1 +/- 35.5 cm2 (p<0.001) per session. Adverse events included two intra-procedural LAMS dislodgements managed endoscopically and three perforations none of which were related to EndoRotor. Bleeding was reported in seven cases, none required embolic or surgical therapy and two required blood transfusions. CONCLUSIONS: This is the first multi-center retrospective study to investigate the efficacy and safety of the 5.1 mm EndoRotor catheter for WON. Results from this study showed an average of 1.6 DEN sessions were needed to achieve WON resolution with an 85% single session reduction in solid debris and a 70% single session decrease in WON area with minimal adverse events.

Consensus statements on the current landscape of artificial intelligence applications in endoscopy, addressing roadblocks, and advancing artificial intelligence in gastroenterology.

BACKGROUND AND AIMS: The American Society for Gastrointestinal Endoscopy (ASGE) AI Task Force along with experts in endoscopy, technology space, regulatory authorities, and other medical subspecialties initiated a consensus process that analyzed the current literature, highlighted potential areas, and outlined the necessary research in artificial intelligence (AI) to allow a clearer understanding of AI as it pertains to endoscopy currently. METHODS: A modified Delphi process was used to develop these consensus statements. RESULTS: Statement 1: Current advances in AI allow for the development of AI-based algorithms that can be applied to endoscopy to augment endoscopist performance in detection and characterization of endoscopic lesions. Statement 2: Computer vision-based algorithms provide opportunities to redefine quality metrics in endoscopy using AI, which can be standardized and can reduce subjectivity in reporting quality metrics. Natural language processing-based algorithms can help with the data abstraction needed for reporting current quality metrics in GI endoscopy effortlessly. Statement 3: AI technologies can support smart endoscopy suites, which may help optimize workflows in the endoscopy suite, including automated documentation. Statement 4: Using AI and machine learning helps in predictive modeling, diagnosis, and prognostication. High-quality data with multidimensionality are needed for risk prediction, prognostication of specific clinical conditions, and their outcomes when using machine learning methods. Statement 5: Big data and cloud-based tools can help advance clinical research in gastroenterology. Multimodal data are key to understanding the maximal extent of the disease state and unlocking treatment options. Statement 6: Understanding how to evaluate AI algorithms in the gastroenterology literature and clinical trials is important for gastroenterologists, trainees, and researchers, and hence education efforts by GI societies are needed. Statement 7: Several challenges regarding integrating AI solutions into the clinical practice of endoscopy exist, including understanding the role of human-AI interaction. Transparency, interpretability, and explainability of AI algorithms play a key role in their clinical adoption in GI endoscopy. Developing appropriate AI governance, data procurement, and tools needed for the AI lifecycle are critical for the successful implementation of AI into clinical practice. Statement 8: For payment of AI in endoscopy, a thorough evaluation of the potential value proposition for AI systems may help guide purchasing decisions in endoscopy. Reliable cost-effectiveness studies to guide reimbursement are needed. Statement 9: Relevant clinical outcomes and performance metrics for AI in gastroenterology are currently not well defined. To improve the quality and interpretability of research in the field, steps need to be taken to define these evidence standards. Statement 10: A balanced view of AI technologies and active collaboration between the medical technology industry, computer scientists, gastroenterologists, and researchers are critical for the meaningful advancement of AI in gastroenterology. CONCLUSIONS: The consensus process led by the ASGE AI Task Force and experts from various disciplines has shed light on the potential of AI in endoscopy and gastroenterology. AI-based algorithms have shown promise in augmenting endoscopist performance, redefining quality metrics, optimizing workflows, and aiding in predictive modeling and diagnosis. However, challenges remain in evaluating AI algorithms, ensuring transparency and interpretability, addressing governance and data procurement, determining payment models, defining relevant clinical outcomes, and fostering collaboration between stakeholders. Addressing these challenges while maintaining a balanced perspective is crucial for the meaningful advancement of AI in gastroenterology.

CHOGlycoNET: Comprehensive glycosylation reaction network for CHO cells.

Chinese hamster ovary (CHO) cells are extensively used for the production of glycoprotein therapeutics proteins, for which N-linked glycans are a critical quality attribute due to their influence on activity and immunogenicity. Manipulation of protein glycosylation is commonly achieved through cell or process engineering, which are often guided by mathematical models. However, each study considers a unique glycosylation reaction network that is tailored around the cell line and product at hand. Herein, we use 200 glycan datasets for both recombinantly produced and native proteins from different CHO cell lines to reconstruct a comprehensive reaction network, CHOGlycoNET, based on the individual minimal reaction networks describing each dataset. CHOGlycoNET is used to investigate the distribution of mannosidase and glycosyltransferase enzymes in the Golgi apparatus and identify key network reactions using machine learning and dimensionality reduction techniques. CHOGlycoNET can be used for accelerating glycomodel development and predicting the effect of glycoengineering strategies. Finally, CHOGlycoNET is wrapped in a SBML file to be used as a standalone model or in combination with CHO cell genome scale models.

Genome-wide screens uncover KDM2B as a modifier of protein binding to heparan sulfate.

Heparan sulfate (HS) proteoglycans bind extracellular proteins that participate in cell signaling, attachment and endocytosis. These interactions depend on the arrangement of sulfated sugars in the HS chains generated by well-characterized biosynthetic enzymes; however, the regulation of these enzymes is largely unknown. We conducted genome-wide CRISPR-Cas9 screens with a small-molecule ligand that binds to HS. Screening of A375 melanoma cells uncovered additional genes and pathways impacting HS formation. The top hit was the epigenetic factor KDM2B, a histone demethylase. KDM2B inactivation suppressed multiple HS sulfotransferases and upregulated the sulfatase SULF1. These changes differentially affected the interaction of HS-binding proteins. KDM2B-deficient cells displayed decreased growth rates, which was rescued by SULF1 inactivation. In addition, KDM2B deficiency altered the expression of many extracellular matrix genes. Thus, KDM2B controls proliferation of A375 cells through the regulation of HS structure and serves as a master regulator of the extracellular matrix.

EUS-guided Gastroenterostomy: A Multicenter International Study Comparing Benign and Malignant Diseases.

BACKGROUND: Endoscopic ultrasound (EUS)-guided gastroenterostomy (EUS-GE) is a minimally invasive therapy for patients with gastric outlet obstruction without the risks of surgical bypass and the limited long-term efficacy of enteral self-expanding metal stent placement. However, due to its novelty, there is a lack of significant data comparing long-term outcomes of patients with EUS-GE, based on the underlying disease. In this study, we compare outcomes of EUS-GE on benign versus malignant indications. METHODS: Consecutive patients from 12 international, tertiary care centers who underwent EUS-GE over 3 years were extracted in a retrospective registry. Demographic characteristics, procedure-related information and follow-up data was collected. Primary outcome was the rate of adverse events associated with EUS-GE and the comparison of the rate of adverse events in benign versus malignant diseases. Secondary outcomes included technical and clinical success as well as hospitalization admission. RESULTS: A total of 103 patients were included: 72 malignant and 31 benign. The characteristics of the patients undergoing EUS-GE is shown in Table 1. The mean age of the cohort was 68 years and 58 years for malignant and benign etiology. Gender distribution was 57% and 39% being females in malignant and benign etiology group, respectively. Clinical success, technical success, average procedure time, and hospital length of stay were similar in both groups. Patients with benign underlying etiology had significantly higher number of surgically altered midgut anatomy (P=0.0379). CONCLUSION: EUS-GE is equally efficient regardless of the underlying etiology (malignant vs. benign), and the adverse events both groups were comparable.

ZNF263 is a transcriptional regulator of heparin and heparan sulfate biosynthesis.

Heparin is the most widely prescribed biopharmaceutical in production globally. Its potent anticoagulant activity and safety makes it the drug of choice for preventing deep vein thrombosis and pulmonary embolism. In 2008, adulterated material was introduced into the heparin supply chain, resulting in several hundred deaths and demonstrating the need for alternate sources of heparin. Heparin is a fractionated form of heparan sulfate derived from animal sources, predominantly from connective tissue mast cells in pig mucosa. While the enzymes involved in heparin biosynthesis are identical to those for heparan sulfate, the factors regulating these enzymes are not understood. Examination of the promoter regions of all genes involved in heparin/heparan sulfate assembly uncovered a transcription factor-binding motif for ZNF263, a C2H2 zinc finger protein. CRISPR-mediated targeting and siRNA knockdown of ZNF263 in mammalian cell lines and human primary cells led to dramatically increased expression levels of HS3ST1, a key enzyme involved in imparting anticoagulant activity to heparin, and HS3ST3A1, another glucosaminyl 3-O-sulfotransferase expressed in cells. Enhanced 3-O-sulfation increased binding to antithrombin, which enhanced Factor Xa inhibition, and binding of neuropilin-1. Analysis of transcriptomics data showed distinctively low expression of ZNF263 in mast cells compared with other (non-heparin-producing) immune cells. These findings demonstrate a novel regulatory factor in heparan sulfate modification that could further advance the possibility of bioengineering anticoagulant heparin in cultured cells.

Prediction and management of bleeding during endoscopic necrosectomy for pancreatic walled-off necrosis: results of a large retrospective cohort at a tertiary referral center.

BACKGROUND AND AIMS: Lumen-apposing metal stents (LAMSs) provide an endoscopic method for management of walled-off necrosis (WON) and a gateway for the performance of endoscopic necrosectomy (EN). However, bleeding may occur in up to 20% of EN procedures. Predictive factors for bleeding in this patient population are unknown, and there is no agreed-on algorithm for the management of bleeding. The aim of this study was to evaluate preprocedural risk factors for bleeding in patients undergoing endoscopic drainage or EN for WON. METHODS: A retrospective cohort of patients undergoing EN for WON was reviewed. Demographics, comorbidities, concurrent medications, and etiology of pancreatitis were recorded. Pre-, peri-, and postprocedural clinical variables were compared using the χ2 test and independent t test. RESULTS: Between June 2014 and October 2020, 536 ENs were performed in 151 patients. Intraprocedural bleeding occurred during 28 procedures (5.2%) in 18 patients (11.9%). Endoscopic hemostasis was attempted in 8 patients (10 procedures). Eight patients (10 procedures) in total were treated by interventional radiology (IR). Thrombocytopenia (P = .006) and cirrhosis (P = .049) were associated with intraprocedural bleeding, although thrombocytopenia was present in only 1 patient. Identification of a vessel within the cavity endoscopically was also associated with bleeding (P < .001). On multivariate analysis, identification of a vessel within the cavity endoscopically remained a strong predictor of bleeding (P < .001), whereas cirrhosis was no longer significant. Patients who required IR for hemostasis were transfused with significantly more blood before the procedure than patients who did not (3.4 units vs .67 units, P = .002). CONCLUSIONS: EN for WON was associated with a 5.2% per-procedure risk of bleeding and an 11.9% per-patient bleeding risk. Identification of a vessel within the cavity during endoscopy is predictive of bleeding during EN. Patients who require more transfusions before endoscopy may require earlier intervention by IR.

Safety and efficacy of a novel resection system for direct endoscopic necrosectomy of walled-off pancreas necrosis: a prospective, international, multicenter trial.

BACKGROUND AND AIMS: Direct endoscopic necrosectomy (DEN) of walled-off pancreatic necrosis (WOPN) lacks dedicated instruments and requires repetitive and cumbersome procedures. This study evaluated the safety and efficacy of a new powered endoscopic debridement (PED) system designed to simultaneously resect and remove solid debris within WOPN. METHODS: This was a single-arm, prospective, multicenter, international device trial conducted from November 2018 to August 2019 at 10 sites. Patients with WOPN ≥6 cm and ≤22 cm and with >30% solid debris were enrolled. The primary endpoint was safety through 21 days after the last DEN procedure. Efficacy outcomes included clearance of necrosis, procedural time, adequacy of debridement, number of procedures until resolution, hospital stay duration, and quality of life. RESULTS: Thirty patients (mean age, 55 years; 60% men) underwent DEN with no device-related adverse events. Of 30 patients, 15 (50%) achieved complete debridement in 1 session and 20 (67%) achieved complete debridement within 2 or fewer sessions. A median of 1.5 interventions (range, 1-7) were required. Median hospital stay was 10 days (interquartile range, 22). There was an overall reduction of 91% in percent necrosis within WOPN from baseline to follow-up and 85% in collection volume. Baseline WOPN volume was positively correlated with the total number of interventions (ρ = .363, P = .049). CONCLUSIONS: The new PED system seems to be a safe and effective treatment tool for WOPN, resulting in fewer interventions and lower hospital duration when compared with published data on using conventional instruments. Randomized controlled trials comparing the PED system with conventional DEN are needed. (Clinical trial registration number: NCT03694210.).

A unique esophageal extracellular matrix proteome alters normal fibroblast function in severe eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic TH2 disorder complicated by tissue fibrosis and loss of esophageal luminal patency. The fibrostenotic esophagus does not respond well to therapy, but profibrotic therapeutic targets are largely unclear. OBJECTIVE: Our aim was to utilize proteomics and primary cells as a novel approach to determine relevant profibrotic factors. METHODS: We utilized primary esophageal EoE and normal fibroblasts, their derivative extracellular matrixes (ECMs), an approach of fibroblast culture on autologous versus nonautologous ECM, and proteomics to elucidate EoE ECM proteins that dysregulate cellular function. RESULTS: We cultured esophageal fibroblasts from normal esophagi and esophagi from patients with severe EoE on autologous versus nonautologous ECM. The EoE ECM proteome shifted normal esophageal fibroblast protein expression. Proteomic analysis demonstrated that thrombospondin-1 is detected only in the EoE ECM, is central in the EoE ECM protein-protein interactome, is found at significantly elevated levels in biopsy specimens from patients with active EoE, and induces fibroblast collagen I production. CONCLUSION: Fibroblasts from patients with EoE secrete a unique ECM proteome that reflects their in vivo state and induces collagen I and α-smooth muscle actin protein expression from normal fibroblasts. Thrombospondin-1 is a previously unappreciated profibrotic molecule in EoE.

Increased Production of LIGHT by T Cells in Eosinophilic Esophagitis Promotes Differentiation of Esophageal Fibroblasts Toward an Inflammatory Phenotype.

BACKGROUND & AIMS: Eosinophilic esophagitis (EoE) is an antigen-mediated eosinophilic disease of the esophagus that involves fibroblast activation and progression to fibrostenosis. Cytokines produced by T-helper type 2 cells and transforming growth factor beta 1 (TGFß1) contribute to the development of EoE, but other cytokines involved in pathogenesis are unknown. We investigate the effects of tumor necrosis factor superfamily member 14 (TNFSF14, also called LIGHT) on fibroblasts in EoE. METHODS: We analyzed publicly available esophageal CD3+ T-cell single-cell sequencing data for expression of LIGHT. Esophageal tissues were obtained from pediatric patients with EoE or control individuals and analyzed by immunostaining. Human primary esophageal fibroblasts were isolated from esophageal biopsy samples of healthy donors or patients with active EoE. Fibroblasts were cultured; incubated with TGFß1 and/or LIGHT; and analyzed by RNA sequencing, flow cytometry, immunoblots, immunofluorescence, or reverse transcription polymerase chain reaction. Eosinophils were purified from peripheral blood of healthy donors, incubated with interleukin 5, cocultured with fibroblasts, and analyzed by immunohistochemistry. RESULTS: LIGHT was up-regulated in the esophageal tissues from patients with EoE, compared with control individuals, and expressed by several T-cell populations, including T-helper type 2 cells. TNF receptor superfamily member 14 (TNFRSF14, also called HVEM) and lymphotoxin beta receptor are receptors for LIGHT that were expressed by fibroblasts from healthy donors or patients with active EoE. Stimulation of esophageal fibroblasts with LIGHT induced inflammatory gene transcription, whereas stimulation with TGFß1 induced transcription of genes associated with a myofibroblast phenotype. Stimulation of fibroblasts with TGFß1 increased expression of HVEM; subsequent stimulation with LIGHT resulted in their differentiation into cells that express markers of myofibroblasts and inflammatory chemokines and cytokines. Eosinophils tethered to esophageal fibroblasts after LIGHT stimulation via intercellular adhesion molecule-1. CONCLUSIONS: T cells in esophageal tissues from patients with EoE express increased levels of LIGHT compared with control individuals, which induces differentiation of fibroblasts into cells with inflammatory characteristics. TGFß1 increases fibroblast expression of HVEM, a receptor for LIGHT. LIGHT mediates interactions between esophageal fibroblasts and eosinophils via ICAM1. This pathway might be targeted for the treatment of EoE.

Confidentiality and Conflicts of Interest: An Assessment of Twitter Posts in Gastrointestinal Endoscopy.

INTRODUCTION: To evaluate compliance with confidentiality and conflicts of interest (COI) in tweets sharing gastrointestinal (GI) endoscopy videos/images. METHODS: Physicians' tweets containing GI endoscopy videos/images were assessed for confidentiality and COI compliance. RESULTS: Identifiable details in tweets included procedure date (17.9%), date of birth (0.8%), and patient's face visible (0.5%). Ninety-five tweets (10%) mentioned the name/brand of a medical device. Of the 19 posted by US physicians, 7 came from physicians who had received payments from the device manufacturer. None of these physicians disclosed relevant COI. DISCUSSION: GI endoscopy tweets describing clinical cases or procedures may insufficiently address issues of confidentiality and COI.

Survey Finds Gender Disparities Impact Both Women Mentors and Mentees in Gastroenterology.

INTRODUCTION: Gastroenterologists at all levels of practice benefit from formal mentoring. Much of the current literature on mentoring in gastroenterology is based on expert opinion rather than data. In this study, we aimed to identify gender-related barriers to successful mentoring relationships from the mentor and mentee perspectives. METHODS: A voluntary, web-based survey was distributed to physicians at 20 academic institutions across the United States. Overall, 796 gastroenterology fellows and faculty received the survey link, with 334 physicians responding to the survey (42% response rate), of whom 299 (90%; 129 women and 170 men) completed mentorship questions and were included in analysis. RESULTS: Responses of women and men were compared. Compared with men, more women preferred a mentor of the same gender (38.6% women vs 4.2% men, P < 0.0001) but less often had one (45.5% vs 70.2%, P < 0.0001). Women also reported having more difficulty finding a mentor (44.4% vs 16.0%, P < 0.0001) and more often cited inability to identify a mentor of the same gender as a contributing factor (12.8% vs 0.9%, P = 0.0004). More women mentors felt comfortable advising women mentees about work-life balance (88.3% vs 63.8%, P = 0.0005). Nonetheless, fewer women considered themselves effective mentors (33.3% vs 52.6%, P = 0.03). More women reported feeling pressured to mentor because of their gender (39.5% vs 0.9% of men, P < 0.0001). Despite no gender differences, one-third of respondents reported negative impact of the COVID-19 pandemic on their ability to mentor and be mentored. DISCUSSION: Inequities exist in the experiences of women mentees and mentors in gastroenterology, which may affect career advancement and job satisfaction.

Systems glycobiology for discovering drug targets, biomarkers, and rational designs for glyco-immunotherapy.

Cancer immunotherapy has revolutionized treatment and led to an unprecedented wave of immuno-oncology research during the past two decades. In 2018, two pioneer immunotherapy innovators, Tasuku Honjo and James P. Allison, were awarded the Nobel Prize for their landmark cancer immunotherapy work regarding "cancer therapy by inhibition of negative immune regulation" -CTLA4 and PD-1 immune checkpoints. However, the challenge in the coming decade is to develop cancer immunotherapies that can more consistently treat various patients and cancer types. Overcoming this challenge requires a systemic understanding of the underlying interactions between immune cells, tumor cells, and immunotherapeutics. The role of aberrant glycosylation in this process, and how it influences tumor immunity and immunotherapy is beginning to emerge. Herein, we review current knowledge of miRNA-mediated regulatory mechanisms of glycosylation machinery, and how these carbohydrate moieties impact immune cell and tumor cell interactions. We discuss these insights in the context of clinical findings and provide an outlook on modulating the regulation of glycosylation to offer new therapeutic opportunities. Finally, in the coming age of systems glycobiology, we highlight how emerging technologies in systems glycobiology are enabling deeper insights into cancer immuno-oncology, helping identify novel drug targets and key biomarkers of cancer, and facilitating the rational design of glyco-immunotherapies. These hold great promise clinically in the immuno-oncology field.

Maximizing success in single-session EUS-directed transgastric ERCP: a retrospective cohort study to identify predictive factors of stent migration.

BACKGROUND AND AIMS: EUS-directed transgastric ERCP (the EDGE procedure) is a simplified method of performing ERCP in Roux-en-Y gastric bypass patients. The EDGE procedure involves placement of a lumen-apposing metal stent (LAMS) into the excluded stomach to serve as a conduit for passage of the duodenoscope for pancreatobiliary intervention. Originally a multistep process, urgent indications for ERCP have led to the development of single-session EDGE (SS-EDGE) with LAMS placement and ERCP performed in the same session. The goal of this study was to identify predictive factors of intraprocedural LAMS migration in SS-EDGE. METHODS: We conducted a multicenter retrospective review that included 9 tertiary medical centers across the United States. Data were collected and analyzed from 128 SS-EDGE procedures. The primary outcome was intraprocedural LAMS migration. Secondary outcomes were other procedural adverse events such as bleeding and perforation. RESULTS: Eleven LAMS migrations were observed in 128 procedures (8.6%). Univariate analysis of clinically relevant variables was performed, as was a binary logistic regression analysis of stent diameter and stent dilation. This revealed that use of a smaller (15 mm) diameter LAMS was an independent predictor of intraprocedural stent migration (odds ratio, 5.36; 95% confidence interval, 1.29-22.24; P = .021). Adverse events included 3 patients who required surgery and 2 who experienced intraprocedural bleeding. CONCLUSIONS: Use of a larger-diameter LAMS is a predictive factor for a nonmigrated stent and improved procedural success in SS-EDGE. Although larger patient cohorts are needed to adequately assess these findings, performance of LAMS dilation and fixation may also decrease risk of intraprocedural LAMS migration and improve procedural success.

Endoscopic ultrasound-directed transgastric ERCP (EDGE): a retrospective multicenter study.

BACKGROUND: Endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography (ERCP; EDGE) is an alternative to enteroscopy- and laparoscopy-assisted ERCP in patients with Roux-en-Y gastric bypass anatomy. Although short-term results are promising, the long-term outcomes are not known. The aims of this study were: (1) to determine the rates of long-term adverse events after EDGE, with a focus on rates of persistent gastrogastric or jejunogastric fistula; (2) to identify predictors of persistent fistula; (3) to assess the outcomes of endoscopic closure when persistent fistula is encountered. METHODS: This was a multicenter retrospective study involving 13 centers between February 2015 and March 2019. Adverse events were defined according to the ASGE lexicon. Persistent fistula was defined as an upper gastrointestinal series or esophagogastroduodenoscopy showing evidence of fistula. RESULTS: 178 patients (mean age 58 years, 79 % women) underwent EDGE. Technical success was achieved in 98 % of cases (175/178), with a mean procedure time of 92 minutes. Periprocedural adverse events occurred in 28 patients (15.7 %; mild 10.1 %, moderate 3.4 %, severe 2.2 %). The four severe adverse events were managed laparoscopically. Persistent fistula was diagnosed in 10 % of those sent for objective testing (9/90). Following identification of a fistula, 5 /9 patients underwent endoscopic closure procedures, which were successful in all cases. CONCLUSIONS: The EDGE procedure is associated with high clinical success rates and an acceptable risk profile. Persistent fistulas after lumen-apposing stent removal are uncommon, but objective testing is recommended to identify their presence. When persistent fistulas are identified, endoscopic treatment is warranted, and should be successful in closing the fistula.