During embryogenesis, the pancreas develops from separate dorsal and ventral buds, which fuse to form the mature pancreas. Little is known about the functional differences between these two buds or the relative contribution of cells derived from each region to the pancreas after fusion. To follow the fate of dorsal or ventral bud derived cells in the pancreas after fusion, we produced chimeric Elas-GFP transgenic/wild-type embryos in which either dorsal or ventral pancreatic bud cells expressed GFP. We found that ventral pancreatic cells migrate extensively into the dorsal pancreas after fusion, whereas the converse does not occur. Moreover, we found that annular pancreatic tissue is composed exclusively of ventral pancreas-derived cells. To identify ventral pancreas-specific genes that may play a role in pancreatic bud fusion, we isolated individual dorsal and ventral pancreatic buds, prior to fusion, from NF38/39 Xenopus laevis tadpoles and compared their gene expression profiles (NF refers to the specific stage of Xenopus development). As a result of this screen, we have identified several new ventral pancreas-specific genes, all of which are expressed in the same location within the ventral pancreas at the junction where the two ventral pancreatic buds fuse. Morpholinomediated knockdown of one of these ventral-specific genes, transmembrane 4 superfamily member 3 (tm4sf3), inhibited dorsalventral pancreatic bud fusion, as well as acinar cell differentiation. Conversely, overexpression of tm4sf3 promoted development of annular pancreas. Our results are the first to define molecular and behavioral differences between the dorsal and ventral pancreas, and suggest an unexpected role for the ventral pancreas in pancreatic bud fusion.

Background: In medical and surgical departments around the world, morbidity and mortality conferences (MMC) serve dual roles: they are cornerstones of quality-improvement programs and provide timely opportunities for education within the urgent context of clinical care. Despite the widespread adoption of MMCs, adverse events and preventable errors remain high or incompletely characterized, and opportunities to learn from and adjust to these events are frequently lost. This review examines the published literature on strategies to improve surgical MMCs. Methods:We searched OVID Medline, PubMed, Embase and CENTRAL. We defined our combination of search terms using a PICO (population, intervention, comparison, outcome) model, focusing on the use of MMCs in general surgery. Results:The MMC literature focused on 5 themes: educational value, error analysis, case selection and representation, attendance and dissemination. Strategies used to increase educational value included limiting case presentation time to 15-20 minutes, mandatory brief literature reviews, increasing audience interaction, and standardizing presentations using a PowerPoint template or SBAR (situation, background, assessment, recommendation) format. Interventions to improve error analysis included focused discussion on causative factors and taxonomic error analysis. Case selection was improved by using an electronic clinical registry, such as the National Surgery Quality Improvement Program, to better capture incidence of morbidity and mortality. Attendance was improved with teleconferencing. Dissemination strategies included MMC newsletters, incorporating MMCs into plan-do-check-act cycles, and surgeon report cards. Conclusion:Greater standardization of best practices may increase the quality improvement and educational impact of MMCs and provide a baseline to measure the effect of new MMC format innovations on the clinical and educational performance of surgical systems. Contexte : Dans les services de médecine et de chirurgie du monde entier, les conférences sur la morbidité et la mortalité (CMM) jouent 2 rôles : elles forment la pierre angulaire des programmes d'amélioration de la qualité de soins et fournissent l'occasion de faire de l'enseignement dans le contexte même des soins cliniques immédiats. Malgré la popularité grandissante des CMM, le nombre d'événements indési rables et d'erreurs évitables demeure élevé ou mal caractérisé et on perd beaucoup d'occasions d'apprendre de ces événements et d'apporter les changements qui s'imposent. La présente revue analyse la littérature publiée sur les stratégies d'amélioration des CMM en chirurgie. Méthodes : Nous avons interrogé OVID Medline, PubMed, Embase et CENTRAL. Nous avons défini nos combinaisons de mots clés à l'aide du modèle PICO (population, intervention, comparaison et résultat [outcome]), en mettant l'accent sur l'utilisation des CMM en chirurgie générale.Résultats : La littérature sur les CMM se concentrait sur 5 thèmes : valeur didactique, analyse des erreurs, sélection et représentation...