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The fundamental goal of tissue engineering is to functionally restore or improve damaged tissues or organs. Here we address this in the small bowel using an in vivo xenograft preclinical acute damage model. We investigated the therapeutic capacity of human intestinal organoids (HIOs), which are generated from human pluripotent stem cells (hPSCs), to repair damaged small bowel. We hypothesized that the HIO's cellular complexity would allow it to sustain transmural engraftment. To test this, we developed a rodent injury model where, through luminal delivery, we demonstrated that fragmented HIOs engraft, proliferate, and persist throughout the bowel following repair. Not only was restitution of the mucosal layer observed, but significant incorporation was also observed in the muscularis and vascular endothelium. Further analysis characterized sustained cell type presence within the regenerated regions, retention of proximal regionalization, and the neo-epithelia's function. These findings demonstrate the therapeutic importance of mesenchyme for intestinal injury repair., Competing Interests: Declaration of interests CCHMC has a patent application in process related to the work in this study., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The kidney maintains homeostasis through an array of parallel nephrons, which all originate in development as isolated epithelial structures that later fuse through their distal poles to a system of collecting ducts (CD). This connection is required to generate functional nephrons by providing a pathway for excretion of metabolic waste and byproducts. Currently, methods for differentiating human pluripotent stem cells into kidney organoids generate nephrons that lack CDs and instead terminate as blind-ended tubules. Here we describe a developmentally inspired system that addresses this deficiency through assembly of induced nephrogenic mesenchyme with ureteric bud (UB) tissues, the embryonic building blocks of the kidney's collecting system. The UB progenitors grow and develop into a network of CDs within the organoid, and importantly, they functionally integrate with the nephrons through recapitulating fusion between the distal tubule and CD to create a continuous epithelial lumen. We further showed that proximal-distal nephron specification, fusion frequency, and maturation of the CD can be augmented through temporal manipulation of developmental signaling pathways. This work provides a platform for interrogating the principles and mechanisms underlying nephron-UB fusion and a framework for engineering unobstructed nephrons with patterned collecting systems, an important step toward the de novo generation of functional kidney tissue., Competing Interests: Declaration of Interests M.S., K.W.M., and J.V.B. are co-inventors on pending UB organoid patents, and M.S. and K.W.M. are coinventors on pending integrated organoid technologies described herein. The other authors have no competing financial interests to declare.

Background and Aims: We previously identified small molecules predicted to reverse an ileal gene signature for future Crohn's Disease (CD) strictures. Here we used a new human intestinal organoid (HIO) model system containing macrophages to test a lead candidate, eicosatetraynoic acid (ETYA)., Methods: Induced pluripotent stem cell lines (iPSC) were derived from CD patients and differentiated into macrophages and HIOs. Macrophages and macrophage:HIO co-cultures were exposed to lipopolysaccharide (LPS) with and without ETYA pre-treatment. Cytospin and flow cytometry characterized macrophage morphology and activation markers, and RNA sequencing defined the global pattern of macrophage gene expression. TaqMan Low Density Array, Luminex multiplex assay, immunohistologic staining, and sirius red polarized light microscopy were performed to measure macrophage cytokine production and HIO pro-fibrotic gene expression and collagen content., Results: iPSC-derived macrophages exhibited morphology similar to primary macrophages and expressed inflammatory macrophage cell surface markers including CD64 and CD68. LPS-stimulated macrophages expressed a global pattern of gene expression enriched in CD ileal inflammatory macrophages and matrisome secreted products, and produced cytokines and chemokines including CCL2, IL1B, and OSM implicated in refractory disease. ETYA suppressed CD64 abundance and pro-fibrotic gene expression pathways in LPS stimulated macrophages. Co-culture of LPS-primed macrophages with HIO led to up-regulation of fibroblast activation genes including ACTA2 and COL1A1, and an increase in HIO collagen content. ETYA pre-treatment prevented pro-fibrotic effects of LPS-primed macrophages., Conclusions: ETYA inhibits pro-fibrotic effects of LPS-primed macrophages upon co-cultured HIO. This model may be used in future untargeted screens for small molecules to treat refractory CD., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This study investigates bioelectric stimulation's role in tissue regeneration by enhancing the piezoelectric properties of tissue-engineered grafts using annealed poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) scaffolds. Annealing at temperatures of 80°C, 100°C, 120°C, and 140°C was assessed for its impact on material properties and physiological utility. Analytical techniques such as Differential Scanning Calorimetry (DSC), Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) revealed increased crystallinity with higher annealing temperatures, peaking in β-phase content and crystallinity at 140°C. Scanning Electron Microscopy (SEM) showed that 140°C annealed scaffolds had enhanced lamellar structures, increased porosity, and maximum piezoelectric response. Mechanical tests indicated that 140°C annealing improved elastic modulus, tensile strength, and substrate stiffness, aligning these properties with physiological soft tissues. In vitro assessments in Schwann cells demonstrated favorable responses, with increased cell proliferation, contraction, and extracellular matrix attachment. Additionally, genes linked to extracellular matrix production, vascularization, and calcium signaling were upregulated. The foreign body response in C57BL/6 mice, evaluated through Hematoxylin and Eosin (H&E) and Picrosirius Red staining, showed no differences between scaffold groups, supporting the potential for future functional evaluation of the annealed group in tissue repair.

Competing Interests: H.M.P., J.M.W., M.M.M., and M.A.H. have Patent WO/2018/200481 and US20210115366 in process.

Human organoid model systems have changed the landscape of developmental biology and basic science. They serve as a great tool for human specific interrogation. In order to advance our organoid technology, we aimed to test the compatibility of a piezoelectric material with organoid generation, because it will create a new platform with the potential for sensing and actuating organoids in physiologically relevant ways. We differentiated human pluripotent stem cells into spheroids following the traditional human intestinal organoid (HIO) protocol atop a piezoelectric nanofiber scaffold. We observed that exposure to the biocompatible piezoelectric nanofibers promoted spheroid morphology three days sooner than with the conventional methodology. At day 28 of culture, HIOs grown on the scaffold appeared similar. Both groups were readily transplantable and developed well-organized laminated structures. Graft sizes between groups were similar. Upon characterizing the tissue further, we found no detrimental effects of the piezoelectric nanofibers on intestinal patterning or maturation. Furthermore, to test the practical feasibility of the material, HIOs were also matured on the nanofiber scaffolds and treated with ultrasound, which lead to increased cellular proliferation which is critical for organoid development and tissue maintenance. This study establishes a proof of concept for integrating piezoelectric materials as a customizable platform for on-demand electrical stimulation of cells using remote ultrasonic waveforms in regenerative medicine.

Most organs have tissue-resident immune cells. Human organoids lack these immune cells, which limits their utility in modeling many normal and disease processes. Here, we describe that pluripotent stem cell-derived human colonic organoids (HCOs) co-develop a diverse population of immune cells, including hemogenic endothelium (HE)-like cells and erythromyeloid progenitors that undergo stereotypical steps in differentiation, resulting in the generation of functional macrophages. HCO macrophages acquired a transcriptional signature resembling human fetal small and large intestine tissue-resident macrophages. HCO macrophages modulate cytokine secretion in response to pro- and anti-inflammatory signals and were able to phagocytose and mount a robust response to pathogenic bacteria. When transplanted into mice, HCO macrophages were maintained within the colonic organoid tissue, established a close association with the colonic epithelium, and were not displaced by the host bone-marrow-derived macrophages. These studies suggest that HE in HCOs gives rise to multipotent hematopoietic progenitors and functional tissue-resident macrophages., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Human intestinal organoids (HIOs) derived from pluripotent stem cells provide a valuable model for investigating human intestinal organogenesis and physiology, but they lack the immune components required to fully recapitulate the complexity of human intestinal biology and diseases. To address this issue and to begin to decipher human intestinal-immune crosstalk during development, we generated HIOs containing immune cells by transplanting HIOs under the kidney capsule of mice with a humanized immune system. We found that human immune cells temporally migrate to the mucosa and form cellular aggregates that resemble human intestinal lymphoid follicles. Moreover, after microbial exposure, epithelial microfold cells are increased in number, leading to immune cell activation determined by the secretion of IgA antibodies in the HIO lumen. This in vivo HIO system with human immune cells provides a framework for future studies on infection- or allergen-driven intestinal diseases., (© 2023. The Author(s).)

Background: The postoperative course after pediatric metabolic and bariatric surgery (MBS) cuts across a developmental phase when substance-use behaviors emerge as significant public health concerns., Objective: We examined use of marijuana, conventional cigarettes, and alternate tobacco products/devices (e.g., e-cigarettes, hookah, smokeless, dissolvable) in young adults (YA) to 6 years postsurgery., Setting: Five academic medical centers., Methods: In a prospective observational cohort series, 139 surgical (M age = 16.9, M body mass index [BMI] = 51.5, 80% female, 66% white) and 83 nonsurgical comparisons (M age = 16.1, M BMI = 44.9, 82% female, 54% white) completed assessments at presurgery/baseline and postsurgery years 2, 4, and 6 (year 6 [2014-2018]: surgical n = 123 [89%], M age = 23.0, M BMI = 39.8; nonsurgical n = 63 [76%], M age = 22.4, M BMI = 53.6). Lifetime and current (past 30 days) use were reported., Results: Consistent with national YA trends (2014-2018), the most commonly used were (1) conventional cigarettes (30% surgical, 41% nonsurgical, nonsignificant [ns]); (2) marijuana (25% surgical, 27% nonsurgical, ns); and (3) e-cigarettes (12% surgical, 10% nonsurgical). A sizable minority (26% surgical, 18% nonsurgical) used one or more alternate tobacco product/device. Many YA reported persistent and/or heavy use (e.g., >50% marijuana at year 6 and year 2 or 4; ≈50% ≥.5 pack/d of cigarettes), suggesting more established (versus intermittent) health risk behaviors. For the surgical group at year 6, current tobacco product/device use was associated with lower BMI (P < .001) and greater percent weight loss (P = .002)., Conclusions: Pediatric MBS demonstrates promise in lowering risks for adult chronic disease, which may be diminished by age-typical health risk behaviors. Developmentally salient and holistic pediatric postoperative care guidelines are needed., (Copyright © 2022 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

The in vitro differentiation of pluripotent stem cells into human intestinal organoids (HIOs) has served as a powerful means for creating complex three-dimensional intestinal structures. Owing to their diverse cell populations, transplantation into an animal host is supported with this system and allows the temporal formation of fully laminated structures, including crypt-villus architecture and smooth muscle layers that resemble native human intestine. Although the endpoint of HIO engraftment has been well described, here we aim to elucidate the developmental stages of HIO engraftment and establish whether it parallels fetal human intestinal development. We analyzed a time course of transplanted HIOs histologically at 2, 4, 6 and 8 weeks post-transplantation, and demonstrated that HIO maturation closely resembles key stages of fetal human intestinal development. We also utilized single-nuclear RNA sequencing to determine and track the emergence of distinct cell populations over time, and validated our transcriptomic data through in situ protein expression. These observations suggest that transplanted HIOs do indeed recapitulate early intestinal development, solidifying their value as a human intestinal model system., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

Study Objective: Describe the current practice patterns and diagnostic accuracy of frozen section (FS) pathology for children and adolescents with ovarian masses DESIGN: Prospective cohort study from 2018 to 2021 SETTING: Eleven children's hospitals PARTICIPANTS: Females age 6-21 years undergoing surgical management of an ovarian mass INTERVENTIONS: Obtaining intraoperative FS pathology MAIN OUTCOME MEASURE: Diagnostic accuracy of FS pathology RESULTS: Of 691 patients who underwent surgical management of an ovarian mass, FS was performed in 27 (3.9%), of which 9 (33.3%) had a final malignant pathology. Among FS patients, 12 of 27 (44.4%) underwent ovary-sparing surgery, and 15 of 27 (55.5%) underwent oophorectomy with or without other procedures. FS results were disparate from final pathology in 7 of 27 (25.9%) cases. FS had a sensitivity of 44.4% and specificity of 94.4% for identifying malignancy, with a c-statistic of 0.69. Malignant diagnoses missed on FS included serous borderline tumor (n = 1), mucinous borderline tumor (n = 2), mucinous carcinoma (n = 1), and immature teratoma (n = 1). FS did not guide intervention in 10 of 27 (37.0%) patients: 9 with benign FS underwent oophorectomy, and 1 with malignant FS did not undergo oophorectomy. Of the 9 patients who underwent oophorectomy with benign FS, 5 (55.6%) had benign and 4 (44.4%) had malignant final pathology., Conclusions: FSs are infrequently utilized for pediatric and adolescent ovarian masses and could be inaccurate for predicting malignancy and guiding operative decision-making. We recommend continued assessment and refinement of guidance before any standardization of use of FS to assist with intraoperative decision-making for surgical resection and staging in children and adolescents with ovarian masses., (Copyright © 2022. Published by Elsevier Inc.)

Background/purpose: Controversy persists regarding the ideal surgical approach for repair of esophageal atresia with tracheoesophageal fistula (EA/TEF). We examined complications and outcomes of infants undergoing thoracoscopy and thoracotomy for repair of Type C EA/TEF using propensity score-based overlap weights to minimize the effects of selection bias., Methods: Secondary analysis of two databases from multicenter retrospective and prospective studies examining outcomes of infants with proximal EA and distal TEF who underwent repair at 11 institutions was performed based on surgical approach. Regression analysis using propensity score-based overlap weights was utilized to evaluate outcomes of patients undergoing thoracotomy or thoracoscopy for Type C EA/TEF repair., Results: Of 504 patients included, 448 (89%) underwent thoracotomy and 56 (11%) thoracoscopy. Patients undergoing thoracoscopy were more likely to be full term (37.9 vs. 36.3 weeks estimated gestational age, p < 0.001), have a higher weight at operative repair (2.9 vs. 2.6 kg, p < 0.001), and less likely to have congenital heart disease (16% vs. 39%, p < 0.001). Postoperative stricture rate did not differ by approach, 29 (52%) thoracoscopy and 198 (44%) thoracotomy (p = 0.42). Similarly, there was no significant difference in time from surgery to stricture formation (p > 0.26). Regression analysis using propensity score-based overlap weighting found no significant difference in the odds of vocal cord paresis or paralysis (OR 1.087 p = 0.885), odds of anastomotic leak (OR 1.683 p = 0.123), the hazard of time to anastomotic stricture (HR 1.204 p = 0.378), or the number of dilations (IRR 1.182 p = 0.519) between thoracoscopy and thoracotomy., Conclusion: Infants undergoing thoracoscopic repair of Type C EA/TEF are more commonly full term, with higher weight at repair, and without congenital heart disease as compared to infants repaired via thoracotomy. Utilizing propensity score-based overlap weighting to minimize the effects of selection bias, we found no significant difference in complications based on surgical approach. However, our study may be underpowered to detect such outcome differences owing to the small number of infants undergoing thoracoscopic repair., Level of Evidence: Level III., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Circadian rhythms regulate diverse aspects of gastrointestinal physiology ranging from the composition of microbiota to motility. However, development of the intestinal circadian clock and detailed mechanisms regulating circadian physiology of the intestine remain largely unknown. In this report, we show that both pluripotent stem cell-derived human intestinal organoids engrafted into mice and patient-derived human intestinal enteroids possess circadian rhythms and demonstrate circadian phase-dependent necrotic cell death responses to Clostridium difficile toxin B (TcdB). Intriguingly, mouse and human enteroids demonstrate anti-phasic necrotic cell death responses to TcdB. RNA-Seq analysis shows that ~3-10% of the detectable transcripts are rhythmically expressed in mouse and human enteroids. Remarkably, we observe anti-phasic gene expression of Rac1, a small GTPase directly inactivated by TcdB, between mouse and human enteroids, and disruption of Rac1 abolishes clock-dependent necrotic cell death responses. Our findings uncover robust functions of circadian rhythms regulating clock-controlled genes in both mouse and human enteroids governing organism-specific, circadian phase-dependent necrotic cell death responses, and lay a foundation for human organ- and disease-specific investigation of clock functions using human organoids for translational applications., (© 2021 The Authors Published under the terms of the CC BY NC ND 4.0 license.)

Objective: The aim of this study was to assess current clinical outcomes in children with prenatally diagnosed congenital lung malformations (CLMs) and to identify prenatal characteristics associated with adverse outcomes., Summary Background Data: Despite a wide spectrum of clinical disease, the identification of fetal CLM subgroups at increased risk for hydrops and respiratory compromise at delivery has not been well defined., Methods: A retrospective cohort study was conducted using an operative database of prenatally diagnosed CLMs managed at 11 children's hospitals from 2009 to 2016. Statistical analyses were performed using nonparametric bivariate or multivariable logistic regression., Results: Three hundred forty-four children were analyzed. Fifteen (5.5%) fetuses were managed with maternal steroids in the setting of hydrops, and prenatal surgical intervention was uncommon (1.7%). Seventy-five (21.8%) had respiratory symptoms at birth, and 34 (10.0%) required neonatal lung resection. Congenital pulmonary airway malformation volume ratio (CVR) measurements were recorded in 169 (49.1%) cases and were significantly associated with perinatal outcome, including hydrops, respiratory distress at birth, need for supplemental oxygen, neonatal ventilator use, and neonatal resection ( P < 0.001). An initial CVR ≤1.4 was significantly correlated with a reduced risk for hydrops [area under the curve (AUC), 0.93; 95% confidence interval (CI), 0.87-1.00]. A maximum CVR <0.9 (AUC, 0.72; 95% CI, 0.67-0.85) was associated with a low risk for respiratory symptoms at birth., Conclusions: In this large, multi-institutional study, an initial CVR ≤ 1.4 identifies fetuses at very low risk for hydrops, and a maximum CVR < 0.9 is associated with asymptomatic disease at birth. These findings represent an opportunity for standardization and quality improvement for prenatal counseling and delivery planning., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

A major technical limitation hindering the widespread adoption of human pluripotent stem cell (hPSC)-derived gastrointestinal (GI) organoid technologies is the need for de novo hPSC differentiation and dependence on spontaneous morphogenesis to produce detached spheroids. Here, we report a method for simple, reproducible, and scalable production of small intestinal organoids (HIOs) based on the aggregation of cryopreservable hPSC-derived mid-hindgut endoderm (MHE) monolayers. MHE aggregation eliminates variability in spontaneous spheroid production and generates HIOs that are comparable to those arising spontaneously. With a minor modification to the protocol, MHE can be cryopreserved, thawed, and aggregated, facilitating HIO production without de novo hPSC differentiation. Finally, aggregation can also be used to generate antral stomach organoids and colonic organoids. This improved method removes significant barriers to the implementation and successful use of hPSC-derived GI organoid technologies and provides a framework for improved dissemination and increased scalability of GI organoid production., Competing Interests: Conflicts of interest The authors declare no competing interests., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background & Aims: A subset of myeloid-derived suppressor cells (MDSCs) that express murine Schlafen4 (SLFN4) or its human ortholog SLFN12L polarize in the Helicobacter-inflamed stomach coincident with intestinal or spasmolytic polypeptide-expressing metaplasia. We propose that individuals with a more robust response to damage-activated molecular patterns and increased Toll-like receptor 9 (TLR9) expression are predisposed to the neoplastic complications of Helicobacter infection., Methods: A mouse or human Transwell co-culture system composed of dendritic cells (DCs), 2-dimensional gastric epithelial monolayers, and Helicobacter were used to dissect the cellular source of interferon-α (IFNα) in the stomach by flow cytometry. Conditioned media from the co-cultures polarized primary myeloid cells. MDSC activity was determined by T-cell suppression assays. In human subjects with intestinal metaplasia or gastric cancer, the rs5743836 TLR9T>C variant was genotyped and linked to TLR9, IFNα, and SLFN12L expression by immunohistochemistry. Nuclear factor-κB binding to the TLR9 C allele was determined by electrophoretic mobility shift assays., Results: Helicobacter infection induced gastric epithelial and plasmacytoid DC expression of TLR9 and IFNα. Co-culturing primary mouse or human cells with DCs and Helicobacter induced TLR9, IFNα secretion, and SLFN + -MDSC polarization. Neutralizing IFNα in vivo mitigated Helicobacter-induced spasmolytic polypeptide-expressing metaplasia. The TLR9 minor C allele creates a nuclear factor-κB binding site associated with higher levels of TLR9, IFNα, and SLFN12L in Helicobacter-infected stomachs that correlated with a greater incidence of metaplasias and cancer., Conclusions: TLR9 plays an essential role in the production of IFNα and polarization of SLFN + MDSCs on Helicobacter infection. Subjects carrying the rs5743836 TLR9 minor C allele are predisposed to neoplastic complications if chronically infected., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Importance: The ability of computed tomography (CT) to distinguish between benign congenital lung malformations and malignant cystic pleuropulmonary blastomas (PPBs) is unclear., Objective: To assess whether chest CT can detect malignant tumors among postnatally detected lung lesions in children., Design, Setting, and Participants: This retrospective multicenter case-control study used a consortium database of 521 pathologically confirmed primary lung lesions from January 1, 2009, through December 31, 2015, to assess diagnostic accuracy. Preoperative CT scans of children with cystic PPB (cases) were selected and age-matched with CT scans from patients with postnatally detected congenital lung malformations (controls). Statistical analysis was performed from January 18 to September 6, 2020. Preoperative CT scans were interpreted independently by 9 experienced pediatric radiologists in a blinded fashion and analyzed from January 24, 2019, to September 6, 2020., Main Outcomes and Measures: Accuracy, sensitivity, and specificity of CT in correctly identifying children with malignant tumors., Results: Among 477 CT scans identified (282 boys [59%]; median age at CT, 3.6 months [IQR, 1.2-7.2 months]; median age at resection, 6.9 months [IQR, 4.2-12.8 months]), 40 cases were extensively reviewed; 9 cases (23%) had pathologically confirmed cystic PPB. The median age at CT was 7.3 months (IQR, 2.9-22.4 months), and median age at resection was 8.7 months (IQR, 5.0-24.4 months). The sensitivity of CT for detecting PPB was 58%, and the specificity was 83%. High suspicion for malignancy correlated with PPB pathology (odds ratio, 13.5; 95% CI, 2.7-67.3; P = .002). There was poor interrater reliability (κ = 0.36 [range, 0.06-0.64]; P < .001) and no significant difference in specific imaging characteristics between PPB and benign cystic lesions. The overall accuracy rate for distinguishing benign vs malignant lesions was 81%., Conclusions and Relevance: This study suggests that chest CT, the current criterion standard imaging modality to assess the lung parenchyma, may not accurately and reliably distinguish PPB from benign congenital lung malformations in children. In any cystic lung lesion without a prenatal diagnosis, operative management to confirm pathologic diagnosis is warranted.

Introduction: Anastomotic stricture is the most common complication after esophageal atresia (EA) repair. We sought to determine if postoperative acid suppression is associated with reduced stricture formation., Methods: A prospective, multi-institutional cohort study of infants undergoing primary EA repair from 2016 to 2020 was performed. Landmark analysis and multivariate Cox regression were used to explore if initial duration of acid suppression was associated with stricture formation at hospital discharge (DC), 3-, 6-, and 9-months postoperatively., Results: Of 156 patients, 79 (51%) developed strictures and 60 (76%) strictures occurred within three months following repair. Acid suppression was used in 141 patients (90%). Landmark analysis showed acid suppression was not associated with reduction in initial stricture formation at DC, 3-, 6- and 9-months, respectively (p = 0.19-0.95). Multivariate regression demonstrated use of a transanastomotic tube was significantly associated with stricture formation at DC (Hazard Ratio (HR) = 2.21 (95% CI 1.24-3.95, p<0.01) and 3-months (HR 5.31, 95% CI 1.65-17.16, p<0.01). There was no association between acid suppression duration and stricture formation., Conclusion: No association between the duration of postoperative acid suppression and anastomotic stricture was observed. Transanastomotic tube use increased the risk of anastomotic strictures at hospital discharge and 3 months after repair., Competing Interests: Declarations of Competing Interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Importance: The factors associated with the failure of nonoperative management of appendicitis and the differences in patient-reported outcomes between successful and unsuccessful nonoperative management remain unknown., Objectives: To investigate factors associated with the failure of nonoperative management of appendicitis and compare patient-reported outcomes between patients whose treatment succeeded and those whose treatment failed., Design, Setting, and Participants: This study was a planned subgroup secondary analysis conducted in 10 children's hospitals that included 370 children aged 7 to 17 years with uncomplicated appendicitis enrolled in a prospective, nonrandomized clinical trial between May 1, 2015, and October 31, 2018, with 1-year follow-up comparing nonoperative management with antibiotics vs surgery for uncomplicated appendicitis. Statistical analysis was performed from November 1, 2019, to February 12, 2022., Interventions: Nonoperative management with antibiotics vs surgery., Main Outcomes and Measures: Failure of nonoperative management and patient-reported outcomes. The relative risk (RR) of failure based on sociodemographic and clinical characteristics was calculated. Patient-reported outcomes were compared based on the success or failure of nonoperative management., Results: Of 370 patients (34.6% of 1068 total patients; 229 boys [61.9%]; median age, 12.3 years [IQR, 10.0-14.6 years]) enrolled in the nonoperative group, treatment failure occurred for 125 patients (33.8%) at 1 year, with 53 patients (14.3%) undergoing appendectomy during initial hospitalization and 72 patients (19.5%) experiencing delayed treatment failure after hospital discharge. Higher patient-reported pain at presentation was associated with increased risk of in-hospital treatment failure (RR, 2.1 [95% CI, 1.0-4.4]) but not delayed treatment failure (RR, 1.3 [95% CI, 0.7-2.3]) or overall treatment failure at 1 year (RR, 1.5 [95% CI, 1.0-2.2]). Pain duration greater than 24 hours was associated with decreased risk of delayed treatment failure (RR, 0.3 [95% CI, 0.1-1.0]) but not in-hospital treatment failure (RR, 1.2 [95% CI, 0.5-2.7]) or treatment failure at 1 year (RR, 0.7 [95% CI, 0.4-1.2]). There was no increased risk of treatment failure associated with age, white blood cell count, sex, race, ethnicity, primary language, insurance status, transfer status, symptoms at presentation, or imaging results. Health care satisfaction at 30 days and patient-reported, health-related quality of life at 30 days and 1 year were not different. Satisfaction with the decision was higher with successful nonoperative management at 30 days (28.0 vs 27.0; difference, 1.0 [95% CI, 0.01-2.0]) and 1 year (28.1 vs 27.0; difference, 1.1 [95% CI, 0.2-2.0])., Conclusions and Relevance: This analysis suggests that a higher pain level at presentation was associated with a higher risk of initial failure of nonoperative management and that a longer duration of pain was associated with lower risk of delayed treatment failure. Although satisfaction was high in both groups, satisfaction with the treatment decision was higher among patients with successful nonoperative management at 1 year., Trial Registration: ClinicalTrials.gov Identifier: NCT02271932.

Sonic Hedgehog (Shh), secreted from gastric parietal cells, contributes to the regeneration of the epithelium. The recruitment of macrophages plays a central role in the regenerative process. The mechanism that regulates macrophage recruitment in response to gastric injury is largely unknown. Here we tested the hypothesis that Shh stimulates macrophage chemotaxis to the injured epithelium and contributes to gastric regeneration. A mouse model expressing a myeloid cell-specific deletion of Smoothened (LysMcre/+;Smof/f) was generated using transgenic mice bearing loxP sites flanking the Smo gene (Smo loxP) and mice expressing a Cre recombinase transgene from the Lysozyme M locus (LysMCre). Acetic acid injury was induced in the stomachs of both control and LysMcre/+;Smof/f (SmoKO) mice and gastric epithelial regeneration and macrophage recruitment analyzed over a period of 7 days post-injury. Bone marrow-derived macrophages (BM-Mø) were collected from control and SmoKO mice. Human-derived gastric organoid/macrophage co-cultures were established, and macrophage chemotaxis measured. Compared to control mice, SmoKO animals exhibited inhibition of ulcer repair and normal epithelial regeneration, which correlated with decreased macrophage infiltration at the site of injury. Bone marrow chimera experiments using SmoKO donor cells showed that control chimera mice transplanted with SmoKO bone marrow donor cells exhibited a loss of ulcer repair, and transplantation of control bone marrow donor cells to SmoKO mice rescued epithelial cell regeneration. Histamine-stimulated Shh secretion in human organoid/macrophage co-cultures resulted in macrophage migration toward the gastric epithelium, a response that was blocked with Smo inhibitor Vismodegib. Shh-induced macrophage migration was mediated by AKT signaling. In conclusion, Shh signaling acts as a macrophage chemoattractant via a Smo-dependent mechanism during gastric epithelial regeneration in response to injury., (© 2022. The Author(s).)

Human organoid model systems lack important cell types that, in the embryo, are incorporated into organ tissues during development. We developed an organoid assembly approach starting with cells from the three primary germ layers-enteric neuroglial, mesenchymal, and epithelial precursors-that were derived separately from human pluripotent stem cells (PSCs). From these three cell types, we generated human antral and fundic gastric tissue containing differentiated glands surrounded by layers of smooth muscle containing functional enteric neurons that controlled contractions of the engineered antral tissue. Using this experimental system, we show that human enteric neural crest cells (ENCCs) promote mesenchyme development and glandular morphogenesis of antral stomach organoids. Moreover, ENCCs can act directly on the foregut to promote a posterior fate, resulting in organoids with a Brunner's gland phenotype. Thus, germ layer components that are derived separately from PSCs can be used for tissue engineering to generate complex human organoids., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

(1) Background: The expression of programmed death-ligand 1 (PD-L1), which interacts with programmed cell death protein 1 (PD-1) on cytotoxic T lymphocytes (CTLs), enables tumors to escape immunosurveillance. The PD-1/PD-L1 interaction results in the inhibition of CTL proliferation, and effector function, thus promoting tumor cell evasion from immunosurveillance and cancer persistence. Despite 40% of gastric cancer patients exhibiting PD-L1 expression, only a small subset of patients responds to immunotherapy. Human epidermal growth factor receptor2 (HER2) is one of the critical regulators of several solid tumors, including metastatic gastric cancer. Although half of PD-L1-positive gastric tumors co-express HER2, crosstalk between HER2 and PD-1/PD-L1 in gastric cancer remains undetermined. (2) Methods: Human gastric cancer organoids (huTGOs) were generated from biopsied or resected tissues and co-cultured with CTLs and myeloid-derived suppressor cells (MDSCs). Digital Spatial Profiling (DSP) was performed on FFPE tissue microarrays of numerous gastric cancer patients to examine the protein expression of immune markers. (3) Results: Knockdown of HER2 in PD-L1/HER2-positive huTGOs led to a concomitant decrease in PD-L1 expression. Similarly, in huTGOs/immune cell co-cultures, PD-L1 expression decreased in huTGOs and was correlated with an increase in CTL proliferation which enhanced huTGO death. Treatment with Nivolumab exhibited similar effects. However, a combinatorial treatment with Mubritinib and Nivolumab was unable to inhibit HER2 expression in co-cultures containing MDSCs. (4) Conclusions: Our study suggested that co-expression of HER2 and PD-L1 may contribute to tumor cell immune evasion. In addition, autologous organoid/immune cell co-cultures can be exploited to effectively screen responses to a combination of anti-HER2 and immunotherapy to tailor treatment for gastric cancer patients.

Purpose: The impact of thoracoscopic surgery on outcomes in children with congenital lung malformations (CLM) remains controversial. The purpose of this study was to determine the effect of operative approach on perioperative outcomes in infants undergoing lobectomy for an asymptomatic CLM., Methods: After IRB approval, a retrospective cohort study was conducted on 506 children with a CLM resected at one of eleven children's hospitals over a seven-year period. Infants undergoing elective lobectomy were identified, and covariates were balanced based on operative approach using propensity scores with full matching. Outcomes were analyzed based on intention to treat with weighted conditional regression., Results: One hundred seventy-five infants met inclusion criteria. There were 67 (38.3%) open, 89 (50.9%) thoracoscopic, and 19 (10.9%) thoracoscopic-converted-to-open lobectomies. Thoracoscopic lobectomy was associated with significantly longer operative times (26 min, 95% CI 6-47 min, p = 0.012) but used less epidural anesthesia (OR 0.02, 95% CI 0.004-0.11, p<0.001) when compared to open lobectomy. There were no significant differences in intraoperative blood loss, postoperative complications, chest tube duration, or length of stay., Conclusions: Thoracoscopy has become the most common operative approach for elective lobectomy in infants with asymptomatic CLMs. The non-inferiority of thoracoscopic lobectomy in postoperative outcomes supports its continued use as an alternative to open lobectomy., Level of Evidence: Treatment study, Level III., Competing Interests: Declaration of Competing Interest The authors indicate no potential conflicts of interest., (Copyright © 2021. Published by Elsevier Inc.)

Human intestinal epithelial organoids (enteroids and colonoids) are tissue cultures used for understanding the physiology of the human intestinal epithelium. Here, we explored the effect on the transcriptome of common variations in culture methods, including extracellular matrix substrate, format, tissue segment, differentiation status, and patient heterogeneity. RNA-sequencing datasets from 276 experiments performed on 37 human enteroid and colonoid lines from 29 patients were aggregated from several groups in the Texas Medical Center. DESeq2 and gene set enrichment analysis (GSEA) were used to identify differentially expressed genes and enriched pathways. PERMANOVA, Pearson's correlation, and dendrogram analysis of the data originally indicated three tiers of influence of culture methods on transcriptomic variation: substrate (collagen vs. Matrigel) and format (3-D, transwell, and monolayer) had the largest effect; segment of origin (duodenum, jejunum, ileum, colon) and differentiation status had a moderate effect; and patient heterogeneity and specific experimental manipulations (e.g., pathogen infection) had the smallest effect. GSEA identified hundreds of pathways that varied between culture methods, such as IL1 cytokine signaling enriched in transwell versus monolayer cultures and E2F target genes enriched in collagen versus Matrigel cultures. The transcriptional influence of the format was furthermore validated in a synchronized experiment performed with various format-substrate combinations. Surprisingly, large differences in organoid transcriptome were driven by variations in culture methods such as format, whereas experimental manipulations such as infection had modest effects. These results show that common variations in culture conditions can have large effects on intestinal organoids and should be accounted for when designing experiments and comparing results between laboratories. Our data constitute the largest RNA-seq dataset interrogating human intestinal epithelial organoids.

Objective: The aim of this study was to determine whether a regional quality improvement (QI) initiative decreased incidence and severity of surgical necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants., Study Design: A retrospective review of all VLBW infants who received care at one of the three hospitals involved in a NEC QI initiative from 2011 to 2016. Primary outcome was the number of surgical NEC cases per year. Secondary outcomes included associated outcomes and mortality., Results: Sixty-three infants with either a diagnosis of Stage III NEC ( n  = 40) or spontaneous intestinal perforation (SIP) ( n  = 23) were included. The incidence of medical and surgical NEC and the mortality rate of infants with surgical NEC decreased over time. Incidence and mortality of SIP did not significantly change., Conclusion: A regional QI bundle to reduce the overall incidence of NEC also significantly decreased the incidence of surgical NEC and all-cause mortality of infants diagnosed with surgical NEC., Key Points: · QI reduces surgical necrotizing enterocolitis.. · Reduction in NEC rate improves mortality.. · Human milk does not change SIP incidence.., Competing Interests: J.W. reports personal fees from Abbott Nutrition, personal fees from Fresenius Kabi, outside the submitted work. The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Tumors evade immune surveillance by expressing Programmed Death-Ligand 1 (PD-L1), subsequently inhibiting CD8 + cytotoxic T lymphocyte function. Response of gastric cancer to immunotherapy is relatively low. Our laboratory has reported that Helicobacter pylori-induced PD-L1 expression within the gastric epithelium is mediated by the Hedgehog (Hh) signaling pathway. The PI3K/AKT/mTOR pathway is activated in gastric cancer and may have immunomodulatory potential. We hypothesize that Hh signaling mediates mTOR-induced PD-L1 expression. Patient-derived organoids (PDOs) were generated from gastric biopsies and resected tumor tissues. Autologous organoid/immune cell co-cultures were used to study the immunosuppressive function of MDSCs. NanoString Digital Spatial Profiling (DSP) of immune-related protein markers using FFPE slide-mounted tissues from gastric cancer patients was performed. DSP analysis showed infiltration of immunosuppressive MDSCs expressing Arg1, CD66b, VISTA and IDO1 within cancer tissues. Orthotopic transplantation of patient derived organoids (PDOs) resulted in the engraftment of organoids and the development of histology similar to that observed in the patient's tumor tissue. PDO/immune cell co-cultures revealed that PD-L1-expressing organoids were unresponsive to nivolumab in vitro in the presence of PMN-MDSCs. Depletion of PMN-MDSCs within these co-cultures sensitized the organoids to anti-PD-1/PD-L1-induced cancer cell death. Rapamycin decreased phosphorylated S6K, Gli2 and PD-L1 expression in PDO/immune cell co-cultures. Transcriptional regulation of PD-L1 by GLI1 and GLI2 was blocked by rapamycin. In conclusion, the PDO/immune cell co-cultures may be used to study immunosuppressive MDSC function within the gastric tumor microenvironment. The mTOR signaling pathway mediates GLI-induced PD-L1 expression in gastric cancer., (Copyright © 2021. Published by Elsevier B.V.)

Introduction: The pathophysiology of type 2 diabetes (T2D) in youth differs from adults and conventional medical treatment approaches with lifestyle change, metformin, thiazolidinediones or insulin are inadequate. Metabolic bariatric surgery (MBS) improves multiple health outcomes in adults with T2D. Initial small, uncontrolled studies of Roux-en-Y gastric bypass have also suggested beneficial effects in adolescents. Definitive studies in youth with T2D are lacking, especially with the now more common form of MBS, vertical sleeve gastrectomy (VSG). The surgical or medical treatment for paediatric type 2 diabetes (ST 2 OMP) clinical trial was designed to test the hypothesis that VSG will more effectively reduce hyperglycaemic and diabetes comorbidities than the best currently available medical treatment incorporating state of the art pharmacotherapies. ST 2 OMP is also designed to better understand the pancreatic and enterohepatic mechanisms by which MBS improves diabetes and its associated comorbidities., Methods and Analysis: ST 2 OMP is a prospective, open-label, controlled clinical trial that will recruit 90 postpubertal participants, age range 13-19.9 years, with body mass index ≥35 kg/m 2 or >120% of 95th percentile and youth-onset T2D. The primary outcome is the per cent of youth achieving haemoglobin A1c <6.0% at 12 months postgroup allocation (post-VSG vs postmedical group allocation). Secondary outcomes include remission of comorbidities and measures of β-cell and incretin responses at 12 and 24 months post VSG versus AMT., Ethics and Dissemination: The ST 2 OMP protocol was approved by the Cincinnati Children's Hospital Medical Center and the University of Colorado Institutional Review Boards. Written informed consent is obtained prior to study enrolment. Study findings will be widely disseminated through peer-reviewed publications and conference presentations., Trial Registration Number: Clinical Trials.Gov NCT04128995., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Recent advances in intestinal organoid research, along with encouraging preclinical proof-of-concept studies, have revealed significant therapeutic potential for induced pluripotent stem cell (iPSC)-derived organoids in the healing and replacement of severely injured or diseased bowel (Finkbeiner et al. Biol Open 4: 1462-1472, 2015; Kitano et al. Nat Commun 8: 765, 2017; Cruz-Acuna et al. Nat Cell Biol 19: 1326-1335, 2017). To fully realize the tremendous promise of stem cell organoid-based therapies, careful planning aligned with significant resources and efforts must be devoted demonstrating their safety and efficacy to meet critical regulatory requirements. Early recognition of the inherent preclinical and clinical obstacles that occur with the novel use of pluripotent stem cell-derived products will accelerate their bench-to-bedside translation (Neofytou et al. J Clin Invest 125: 2551-2557, 2015; O'Brien et al. Stem Cell Res Ther 6: 146, 2015; Ouseph et al. Cytotherapy 17: 339-343, 2015). To overcome many of these hurdles, a close and effective collaboration is needed between experts from various disciplines, including basic and clinical research, product development and manufacturing, quality assurance and control, and regulatory affairs. Therefore, the purpose of this article is to outline the critical areas and challenges that must be addressed when transitioning laboratory-based discovery, through an investigational new drug (IND) application to first-in-human clinical trial, and to encourage investigators to consider the required regulatory steps from the earliest stage of the translational process. The ultimate goal is to provide readers with a draft roadmap that they could use while navigating this exciting cell therapy space.

Emerging evidence suggests a key contribution to non-alcoholic fatty liver disease (NAFLD) pathogenesis by Th17 cells. The pathogenic characteristics and mechanisms of hepatic Th17 cells, however, remain unknown. Here, we uncover and characterize a distinct population of inflammatory hepatic CXCR3 + Th17 (ihTh17) cells sufficient to exacerbate NAFLD pathogenesis. Hepatic ihTh17 cell accrual was dependent on the liver microenvironment and CXCR3 axis activation. Mechanistically, the pathogenic potential of ihTh17 cells correlated with increased chromatin accessibility, glycolytic output, and concomitant production of IL-17A, IFNγ, and TNFα. Modulation of glycolysis using 2-DG or cell-specific PKM2 deletion was sufficient to reverse ihTh17-centric inflammatory vigor and NAFLD severity. Importantly, ihTh17 cell characteristics, CXCR3 axis activation, and hepatic expression of glycolytic genes were conserved in human NAFLD. Together, our data show that the steatotic liver microenvironment regulates Th17 cell accrual, metabolism, and competence toward an ihTh17 fate. Modulation of these pathways holds potential for development of novel therapeutic strategies for NAFLD., Competing Interests: Declaration of interests S.D. is a consultant for Janssen Research & Development., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Pediatric lung lesions are a group of mostly benign pulmonary anomalies with a broad spectrum of clinical disease and histopathology. Our objective was to evaluate the characteristics of children undergoing resection of a primary lung lesion and to identify preoperative risk factors for malignancy., Methods: A retrospective cohort study was conducted by using an operative database of 521 primary lung lesions managed at 11 children's hospitals in the United States. Multivariable logistic regression was used to examine the relationship between preoperative characteristics and risk of malignancy, including pleuropulmonary blastoma (PPB)., Results: None of the 344 prenatally diagnosed lesions had malignant pathology ( P < .0001). Among 177 children without a history of prenatal detection, 15 (8.7%) were classified as having a malignant tumor (type 1 PPB, n = 11; other PPB, n = 3; adenocarcinoma, n = 1) at a median age of 20.7 months (interquartile range, 7.9-58.1). Malignancy was associated with the DICER1 mutation in 8 (57%) PPB cases. No malignant lesion had a systemic feeding vessel ( P = .0427). The sensitivity of preoperative chest computed tomography (CT) for detecting malignant pathology was 33.3% (95% confidence interval [CI]: 15.2-58.3). Multivariable logistic regression revealed that increased suspicion of malignancy by CT and bilateral disease were significant predictors of malignant pathology (odds ratios of 42.15 [95% CI, 7.43-340.3; P < .0001] and 42.03 [95% CI, 3.51-995.6; P = .0041], respectively)., Conclusions: In pediatric lung masses initially diagnosed after birth, the risk of PPB approached 10%. These results strongly caution against routine nonoperative management in this patient population. DICER1 testing may be helpful given the poor sensitivity of CT for identifying malignant pathology., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2021 by the American Academy of Pediatrics.)

Background/purpose: This study evaluated compliance with a multi-institutional quality improvement management protocol for Type-C esophageal atresia with distal tracheoesophageal fistula (EA/TEF)., Methods: Compliance and outcomes before and after implementation of a perioperative protocol bundle for infants undergoing Type-C EA/TEF repair were compared across 11 children's hospitals from 1/2016-1/2019. Bundle components included elimination of prosthetic material between tracheal and esophageal suture lines during repair, not leaving a transanastomotic tube at the conclusion of repair (NO-TUBE), obtaining an esophagram by postoperative-day-5, and discontinuing prophylactic antibiotics 24 h postoperatively., Results: One-hundred seventy patients were included, 40% pre-protocol and 60% post-protocol. Bundle compliance increased 2.5-fold pre- to post-protocol from 17.6% to 44.1% (p < 0.001). After stratifying by institutional compliance with all bundle components, 43.5% of patients were treated at low-compliance centers (<20%), 43% at medium-compliance centers (20-80%), and 13.5% at high-compliance centers (>80%). Rates of esophageal leak, anastomotic stricture, and time to full feeds did not differ between pre- and post-protocol cohorts, though there was an inverse correlation between NO-TUBE compliance and stricture rate over time (ρ = -0.75, p = 0.029)., Conclusions: Compliance with our multi-institutional management protocol increased 2.5-fold over the study period without compromising safety or time to feeds and does not support the use of transanastomotic tubes., Level of Evidence: Level II., Type of Study: Treatment Study., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: To report outcomes of sutured and sutureless closure for gastroschisis across a large multi-institutional cohort., Methods: A retrospective study of infants with uncomplicated gastroschisis at 11 children's from 2014 to 2016 was performed. Outcomes of sutured and sutureless abdominal wall closure were compared., Results: Among 315 neonates with uncomplicated gastroschisis, sutured closure was performed in 248 (79%); 212 undergoing sutured closure after silo and 36 undergoing primary sutured closure. Sutureless closure was performed in 67 (21%); 37 primary sutureless closure, 30 sutureless closure after silo placement. There was no significant difference in gestational age, gender, birth weight, total days on TPN, and time from closure to initial oral intake or goal feeds. Sutureless closure patients had less general anesthetics, ventilator use/time, time from birth to final closure, antibiotic use after closure, and surgical site/deep space infections. Subgroup analysis demonstrated primary sutureless closure had less ventilator use and anesthetics than primary sutured closure. Sutureless closure after silo led to less ventilator use/time, anesthetics, and antibiotics compared to those with sutured closure after silo., Conclusion: Sutureless abdominal wall closure of neonates with gastroschisis was associated with less general anesthetics, antibiotic use, surgical site/deep space infections, and decreased ventilator time. These findings support further prospective study by our group., Level of Evidence: Level III., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The ability to absorb ingested nutrients is an essential function of all metazoans and utilizes a wide array of nutrient transporters found on the absorptive enterocytes of the small intestine. A unique population of patients has previously been identified with severe congenital malabsorptive diarrhea upon ingestion of any enteral nutrition. The intestines of these patients are macroscopically normal, but lack enteroendocrine cells (EECs), suggesting an essential role for this rare population of nutrient-sensing cells in regulating macronutrient absorption. Here, we use human and mouse models of EEC deficiency to identify an unappreciated role for the EEC hormone peptide YY in regulating ion-coupled absorption of glucose and dipeptides. We find that peptide YY is required in the small intestine to maintain normal electrophysiology in the presence of vasoactive intestinal polypeptide, a potent stimulator of ion secretion classically produced by enteric neurons. Administration of peptide YY to EEC-deficient mice restores normal electrophysiology, improves glucose and peptide absorption, diminishes diarrhea and rescues postnatal survival. These data suggest that peptide YY is a key regulator of macronutrient absorption in the small intestine and may be a viable therapeutic option to treat patients with electrolyte imbalance and nutrient malabsorption.

Gastrointestinal organoids are an exciting new tool for modeling human development, physiology, and disease in human tissue. Derived from pluripotent stem cells, gastrointestinal organoids consist of epithelial and mesenchymal cells organized in an intricate, three-dimensional structure that recapitulates the physiology and microscopic anatomy of the human gastrointestinal (GI) tract. In vitro derivation of gastrointestinal organoids from definitive endoderm has permitted an exploration of the complex signaling pathways required for the initial maturation of each individual gastrointestinal organ. Further maturation beyond an early fetal state currently requires transplantation into an immunocompromised host. Transplantation-induced maturation provides an opportunity to functionally interrogate the key mechanisms underlying development of the human GI tract. Gastrointestinal organoids can also be used to model human diseases and ultimately may serve as the basis for developing novel, personalized therapies for human intestinal diseases.

Our group has developed two transplantation models for the engraftment of Human Intestinal Organoids (HIOs): the renal subcapsular space (RSS) and the mesentery each with specific benefits for study. While engraftment at both sites generates laminated intestinal structures, a direct comparison between models has not yet been performed. Embryonic stem cells were differentiated into HIOs, as previously described. HIOs from the same batch were transplanted on the same day into either the RSS or mesentery. 10 weeks were allowed for engraftment and differentiation, at which time they were harvested and assessed. Metrics for comparison included: mortality, engraftment rate, gross size, number and grade of lumens, and expression of markers specific to epithelial differentiation, mesenchymal differentiation, and carbohydrate metabolism. Mortality was significantly increased when undergoing mesentery transplantation, however engraftment was significantly higher. Graft sizes were similar between groups. Morphometric parameters were similar between groups, however m-tHIOs presented with significantly fewer lumens than k-tHIO. Transcript and protein level expression of markers specific to epithelial differentiation, mesenchymal differentiation, and carbohydrate metabolism were similar between groups. Transplantation into both sites yields viable tissue of similar quality based on our assessments with enhanced engraftment and a dominant lumen for uniform study benefiting the mesenteric site and survival benefiting RSS., Competing Interests: The authors have declared that no competing interests exist.

Importance: Nonoperative management with antibiotics alone has the potential to treat uncomplicated pediatric appendicitis with fewer disability days than surgery., Objective: To determine the success rate of nonoperative management and compare differences in treatment-related disability, satisfaction, health-related quality of life, and complications between nonoperative management and surgery in children with uncomplicated appendicitis., Design, Setting, and Participants: Multi-institutional nonrandomized controlled intervention study of 1068 children aged 7 through 17 years with uncomplicated appendicitis treated at 10 tertiary children's hospitals across 7 US states between May 2015 and October 2018 with 1-year follow-up through October 2019. Of the 1209 eligible patients approached, 1068 enrolled in the study., Interventions: Patient and family selection of nonoperative management with antibiotics alone (nonoperative group, n = 370) or urgent (≤12 hours of admission) laparoscopic appendectomy (surgery group, n = 698)., Main Outcomes and Measures: The 2 primary outcomes assessed at 1 year were disability days, defined as the total number of days the child was not able to participate in all of his/her normal activities secondary to appendicitis-related care (expected difference, 5 days), and success rate of nonoperative management, defined as the proportion of patients initially managed nonoperatively who did not undergo appendectomy by 1 year (lowest acceptable success rate, ≥70%). Inverse probability of treatment weighting (IPTW) was used to adjust for differences between treatment groups for all outcome assessments., Results: Among 1068 patients who were enrolled (median age, 12.4 years; 38% girls), 370 (35%) chose nonoperative management and 698 (65%) chose surgery. A total of 806 (75%) had complete follow-up: 284 (77%) in the nonoperative group; 522 (75%) in the surgery group. Patients in the nonoperative group were more often younger (median age, 12.3 years vs 12.5 years), Black (9.6% vs 4.9%) or other race (14.6% vs 8.7%), had caregivers with a bachelor's degree (29.8% vs 23.5%), and underwent diagnostic ultrasound (79.7% vs 74.5%). After IPTW, the success rate of nonoperative management at 1 year was 67.1% (96% CI, 61.5%-72.31%; P = .86). Nonoperative management was associated with significantly fewer patient disability days at 1 year than did surgery (adjusted mean, 6.6 vs 10.9 days; mean difference, -4.3 days (99% CI, -6.17 to -2.43; P < .001). Of 16 other prespecified secondary end points, 10 showed no significant difference., Conclusion and Relevance: Among children with uncomplicated appendicitis, an initial nonoperative management strategy with antibiotics alone had a success rate of 67.1% and, compared with urgent surgery, was associated with statistically significantly fewer disability days at 1 year. However, there was substantial loss to follow-up, the comparison with the prespecified threshold for an acceptable success rate of nonoperative management was not statistically significant, and the hypothesized difference in disability days was not met., Trial Registration: ClinicalTrials.gov Identifier: NCT02271932.

Introduction: The purpose of this study was to develop a multi-institutional registry to characterize the demographics, management, and outcomes of a contemporary cohort of children undergoing congenital lung malformation (CLM) resection., Methods: After central reliance IRB approval, a web-based, secure database was created to capture retrospective cohort data on pathologically-confirmed CLMs performed between 2009 and 2015 within a multi-institutional research collaborative., Results: Eleven children's hospitals contributed 506 patients. Among 344 prenatally diagnosed lesions, the congenital pulmonary airway malformation volume ratio was measured in 49.1%, and fetal MRI was performed in 34.3%. One hundred thirty-four (26.7%) children had respiratory symptoms at birth. Fifty-eight (11.6%) underwent neonatal resection, 322 (64.1%) had surgery at 1-12 months, and 122 (24.3%) had operations after 12 months. The median age at resection was 6.7 months (interquartile range, 3.6-11.4). Among 230 elective lobectomies performed in asymptomatic patients, thoracoscopy was successfully utilized in 102 (44.3%), but there was substantial variation across centers. The most common lesions were congenital pulmonary airway malformation (n = 234, 47.3%) and intralobar bronchopulmonary sequestration (n = 106, 21.4%)., Conclusion: This multicenter cohort study on operative CLMs highlights marked disease heterogeneity and substantial practice variation in preoperative evaluation and operative management. Future registry studies are planned to help establish evidence-based guidelines to optimize the care of these patients., Level of Evidence: Level II., (Copyright © 2019 Elsevier Inc. All rights reserved.)

White adipose tissue inflammation, in part via myeloid cell contribution, is central to obesity pathogenesis. Mechanisms regulating adipocyte inflammatory potential and consequent impact of such inflammation in disease pathogenesis remain poorly defined. We show that activation of the type I interferon (IFN)/IFNα receptor (IFNAR) axis amplifies adipocyte inflammatory vigor and uncovers dormant gene expression patterns resembling inflammatory myeloid cells. IFNβ-sensing promotes adipocyte glycolysis, while glycolysis inhibition impeded IFNβ-driven intra-adipocyte inflammation. Obesity-driven induction of the type I IFN axis and activation of adipocyte IFNAR signaling contributes to obesity-associated pathogenesis in mice. Notably, IFNβ effects are conserved in human adipocytes and detection of the type I IFN/IFNAR axis-associated signatures positively correlates with obesity-driven metabolic derangements in humans. Collectively, our findings reveal a capacity for the type I IFN/IFNAR axis to regulate unifying inflammatory features in both myeloid cells and adipocytes and hint at an underappreciated contribution of adipocyte inflammation in disease pathogenesis.

Background & Aims: Little is known about prevalence and risk factors for nutritional deficiencies in adolescents after metabolic bariatric surgery. We performed a 5-year prospective cohort study of these., Methods: Adolescents who had Roux-en-Y gastric bypass (RYGB, n = 161) or vertical sleeve gastrectomy (VSG, n = 67) were enrolled at 5 tertiary-care centers from March 2007 through February 2012. The final analysis cohort included 226 participants (161 who had RYGB and 65 who had VSG). We measured serum levels of ferritin; red blood cell folate; vitamins A, D, B 1 , B 12 ; and parathyroid hormone at baseline and annually for 5 years. General linear mixed models were used to examine changes over time and identify factors associated with nutritional deficiencies., Results: The participants were 75% female and 72% white, with a mean age of 16.5 ± 1.6 years and mean body mass index of 52.7 ± 9.4 kg/m 2 at surgery. Mean body mass index decreased 23% at 5 years, and did not differ significantly between procedures. After RYGB, but not VSG, serum concentrations of vitamin B 12 significantly decreased whereas serum levels of transferrin and parathyroid hormone increased. Ferritin levels decreased significantly after both procedures. Hypo-ferritinemia was observed in 2.5% of patients before RYGB and 71% at 5 y after RYGB (P < .0001), and 11% of patients before VSG and 45% 5 y after VSG (P = .002). No significant changes in serum levels of folate or vitamins A, B 1 , or D were found between baseline and 5 y after either procedure. By 5 y, 59% of RYGB and 27% of VSG recipients had 2 or more nutritional deficiencies. Risk factors associated with specific deficiencies included surgery type, female sex, black race, supplementation intake, weight regain, and for females, pregnancy., Conclusions: In a prospective study of adolescents who underwent RYGB or VSG, we observed nutritional deficiencies by 5 y after the procedures-particularly in iron and B 12 after RYGB. Ongoing nutrient monitoring and supplementation are recommended for all patients, but surgery type, supplementation intake, sex, and race might affect risk. (Clinical trial registration: Adolescent Bariatrics: Assessing Health Benefits and Risk [also known as Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS)], NCT00474318.)., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Youth-onset type 2 diabetes (T2D) is a formidable threat to the health of obese adolescents because of its potential for early-onset and aggressive co-morbidities and complications. The physiology of youth-onset T2D differs from T2D in adults and is associated with a greater degree of insulin resistance, a more rapid decline in pancreatic β-cell function, and a poorer response to medications. Medical management in youth is focused on combining lifestyle intervention and pharmacological treatment, but these therapies have yet to demonstrate improvements in disease progression. Metabolic bariatric surgery (MBS) is now recommended for the treatment of T2D in adults largely because of the beneficial effects on weight, ability to improve glycemic control, and, in a large proportion of people, induce diabetes remission. MBS is now being performed in adolescents with severe obesity and T2D, with initial results also showing high rates of T2D remission. Here, we review the state of medical management of youth-onset T2D and the outcomes of MBS studies in youth with T2D published to date., (Copyright © 2020. Published by Elsevier Inc.)

Objective: To identify child-, surgeon-, and hospital-specific factors at the time of primary cleft lip repair that are associated with the use of secondary cleft lip surgery., Design: Retrospective cohort study., Setting: Forty-nine pediatric hospitals., Participants: Children who underwent cleft lip repair between 1999 and 2015., Main Outcome Measure: Time from primary cleft lip repair to secondary lip surgery., Results: By 5 years after primary lip repair, 24.0% of children had undergone a secondary lip surgery. In multivariable analysis, primary lip repair before 3 months had a 1.22-fold increased hazard of secondary surgery (95% confidence interval [CI]: 1.02-1.46) compared to repair at 7 to 12 months of age, and children with multiple congenital anomalies had a 0.77-fold decreased hazard of secondary surgery (95% CI: 0.68-0.87). After adjusting for cleft type, age at repair, presence of multiple congenital anomalies, and procedure volume, there remained substantial variation in secondary surgery use among surgeons and hospitals ( P < .01). For children with unilateral cleft lip repaired at 3 to 6 months of age, the predicted proportion of children undergoing secondary surgery within 5 years of primary repair ranged from 4.9% to 21.8% across surgeons and from 4.5% to 24.7% across hospitals., Conclusions: There are substantial differences among surgeons and hospitals in the rates of secondary lip surgery. Further work is needed to identify causes for this variation among providers.

Purpose: Chest tube (CT) management for pediatric primary spontaneous pneumothorax (PSP) is associated with long hospital stays and high recurrence rates. To streamline management, we explored simple aspiration as a test to predict need for surgery., Methods: A multi-institution, prospective pilot study of patients with first presentation for PSP at 9 children's hospitals was performed. Aspiration was performed through a pigtail catheter, followed by 6 h observation with CT clamped. If pneumothorax recurred during observation, the aspiration test failed and subsequent management was per surgeon discretion., Results: Thirty-three patients were managed with simple aspiration. Aspiration was successful in 16 of 33 (48%), while 17 (52%) failed the aspiration test and required hospitalization. Twelve who failed aspiration underwent CT management, of which 10 (83%) failed CT management owing to either persistent air leak requiring VATS or subsequent PSP recurrence. Recurrence rate was significantly greater in the group that failed aspiration compared to the group that passed aspiration [10/12 (83%) vs 7/16 (44%), respectively, P=0.028]., Conclusion: Simple aspiration test upon presentation with PSP predicts chest tube failure with 83% positive predictive value. We recommend changing the PSP management algorithm to include an initial simple aspiration test, and if that fails, proceed directly to VATS., Type of Study: Prospective pilot study LEVEL OF EVIDENCE: Level III., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background & Aims: Shiga toxin (Stx)-producing Escherichia coli (eg, O157:H7) infection produces bloody diarrhea, while Stx inhibits protein synthesis and causes the life-threatening systemic complication of hemolytic uremic syndrome. The murine intestinal tract is resistant to O157:H7 and Stx, and human cells in culture fail to model the complex tissue responses to intestinal injury. We used genetically identical, human stem cell-derived intestinal tissues of varying complexity to study Stx toxicity in vitro and in vivo., Methods: In vitro susceptibility to apical or basolateral exposure to Stx was assessed using human intestinal organoids (HIOs) derived from embryonic stem cells, or enteroids derived from multipotent intestinal stem cells. HIOs contain a lumen, with a single layer of differentiated epithelium surrounded by mesenchymal cells. Enteroids only contain epithelium. In vivo susceptibility was assessed using HIOs, with or without an enteric nervous system, transplanted into mice., Results: Stx induced necrosis and apoptotic death in both epithelial and mesenchymal cells. Responses that require protein synthesis (cellular proliferation and wound repair) also were observed. Epithelial barrier function was maintained even after epithelial cell death was seen, and apical to basolateral translocation of Stx was seen. Tissue cross-talk, in which mesenchymal cell damage caused epithelial cell damage, was observed. Stx induced mesenchymal expression of the epithelial marker E-cadherin, the initial step in mesenchymal-epithelial transition. In vivo responses of HIO transplants injected with Stx mirrored those seen in vitro., Conclusions: Intestinal tissue responses to protein synthesis inhibition by Stx are complex. Organoid models allow for an unprecedented examination of human tissue responses to a deadly toxin., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Human intestinal organoids (HIOs), derived from pluripotent stem cells, are a new tool to gain insights in gastrointestinal development, physiology, and associated diseases. Herein, we present a method for renal transplantation of HIOs in immunocompromised mice and subsequent analysis to study intestinal epithelial cell proliferation. In addition, we describe how to generate enteroids from transplanted HIOs. The method highlights the specific steps to successful engraftment and provides insight into the study of human intestinal stem cells.

Objectives: To evaluate the longitudinal effects of metabolic and bariatric surgery (MBS) on the prevalence of musculoskeletal and lower extremity (LE) pain, physical function, and health-related quality of life., Methods: The Teen Longitudinal Assessment of Bariatric Surgery study (NCT00474318) prospectively collected data on 242 adolescents undergoing MBS at 5 centers over a 3-year follow-up. Joint pain and physical function outcomes were assessed by using the Health Assessment Questionnaire Disability Index, Impact of Weight on Quality of Life - Kids, and the Short Form 36 Health Survey. Adolescents with Blount disease ( n = 9) were excluded., Results: Prevalent musculoskeletal and LE pain were reduced by 40% within 12 months and persisted over 3 years. Adjusted models revealed a 6% lower odds of having musculoskeletal pain (odds ratio = 0.94, 95% confidence interval: 0.92-0.99) and a 10% lower odds of having LE pain (odds ratio = 0.90, 95% confidence interval: 0.86-0.95) per 10% reduction of BMI. The prevalence of poor physical function (Health Assessment Questionnaire Disability Index score >0) declined from 49% to <20% at 6 months ( P < .05), Physical comfort and the physical component scores, measured by the Impact of Weight on Quality of Life - Kids and the Short Form 36 Health Survey, improved at 6 months postsurgery and beyond ( P < .01). Poor physical function predicted persistent joint pain after MBS., Conclusions: Joint pain, impaired physical function, and impaired health-related quality of life significantly improve after MBS. These benefits in patient-reported outcomes support the use of MBS in adolescents with severe obesity and musculoskeletal pain and suggest that MBS in adolescence may reverse and reduce multiple risk factors for future joint disease., Competing Interests: POTENTIAL CONFLICT OF INTEREST: Dr Inge received honoraria and stock options from Standard Bariatrics and honoraria from UpToDate and Independent Medical Expert Consulting Services and served as a consultant for Zafgen, Inc, BioMedical Insights, and L&E Research, all outside the submitted work. Dr Harmon served on an advisory panel for Stryker Corporation from 1998 to 2015, unrelated to this project. Dr Dixon consulted for Apollo Endosurgery, Covidien, Bariatric Advantage, Nestle Health Science, Inova, and Novo Nordisk; the other authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2019 by the American Academy of Pediatrics.)

Background: Adolescent obesity is a significant factor in caring for patients with developmental delay (DD). Sleeve gastrectomy provides durable weight loss for teens with obesity but requires behavioral change that may not occur in patients with DD., Objectives: To determine whether patients with DD had similar weight loss and adverse outcomes to patients without a diagnosis of DD after sleeve gastrectomy., Setting: Academic children's hospital, United States., Methods: Patients with DD undergoing sleeve gastrectomy were matched to adolescents without DD. Chart review was performed to determine etiology and severity of DD, weight, and body mass index (BMI) change in each group at 3, 6, 9, and 12 months postoperatively. One-year emergency department visits, readmissions, and reoperations were reviewed., Results: Ten patients with DD and 44 patients without DD underwent sleeve gastrectomy between 2008 and 2017. Six patients with DD (60%) had mild cognitive impairment, 3 patients (30%) had moderate cognitive impairment, and 1 patient (10%) had severe cognitive impairment. Patients were 81.5% female, had a mean age of 17.3 years, and had a preoperative BMI of 48.6 kg/m 2 . Preoperative BMI was similar in the 2 groups, and percent BMI reduction at 1 year was -29% (95% confidence interval: -35 to -23) and -26% (95% confidence interval: -29 to -23) in groups with and without DD respectively (group by time interaction, P = .27)., Conclusion: Adolescents with DD experience similar 1-year weight loss and adverse events following sleeve gastrectomy to adolescents without DD. Understanding the long-term outcomes for this population is crucial to ensure appropriate implementation of surgical weight loss programs., (Copyright © 2019 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)