Genome-wide association studies using commercially available outbred mice can detect genes involved in phenotypes of biomedical interest. Useful populations need high-frequency alleles to ensure high power to detect quantitative trait loci (QTLs), low linkage disequilibrium between markers to obtain accurate mapping resolution, and an absence of population structure to prevent false positive associations. We surveyed 66 colonies for inbreeding, genetic diversity, and linkage disequilibrium, and we demonstrate that some have haplotype blocks of less than 100 Kb, enabling gene-level mapping resolution. The same alleles contribute to variation in different colonies, so that when mapping progress stalls in one, another can be used in its stead. Colonies are genetically diverse: 45% of the total genetic variation is attributable to differences between colonies. However, quantitative differences in allele frequencies, rather than the existence of private alleles, are responsible for these population differences. The colonies derive from a limited pool of ancestral haplotypes resembling those found in inbred strains: over 95% of sequence variants segregating in outbred populations are found in inbred strains. Consequently it is possible to impute the sequence of any mouse from a dense SNP map combined with inbred strain sequence data, which opens up the possibility of cataloguing and testing all variants for association, a situation that has so far eluded studies in completely outbred populations. We demonstrate the colonies' potential by identifying a deletion in the promoter of H2-Ea as the molecular change that strongly contributes to setting the ratio of CD4+ and CD8+ lymphocytes. We show that commercially available mice are a resource for detecting single genes by genome-wide association. We surveyed 66 populations and identified those with properties conducive to high-resolution mapping. Importantly, we show that the same alleles contribute to variation in different colonies, so that when mapping progress stalls in one colony, another can be used in its stead. As a proof of principle, we detect the same QTL in different colonies influencing CD4⁺/CD8⁺ ratios and refine this mapping to the gene level. We show that a deletion in the promoter of H2-Ea is the molecular change that strongly contributes to setting the ratio of CD4+ and CD8+ lymphocytes. Our results make it possible for geneticists to make informed choices on the use of colonies for genome-wide association studies of complex traits in mice.

The dorsal pancreatic artery is the main artery of the body and tail of the pancreas. Its origin and branching is highly variable. The aim of this study was to perform a meta-analysis to generate pooled prevalence data on the presence and origin of the dorsal pancreatic artery. Clinically important aspects of the dorsal pancreatic artery were summarised during the literature review. Major medical databases were searched. Data on the presence and point of origin of the dorsal pancreatic artery were extracted and quantitatively synthesised. The obtained data of anatomical based studies and computed tomography based studies were statistically analysed. In total, 30 studies, comprising 2322 anatomical and computed tomography based cases were included. The dorsal pancreatic artery was present in 95.8% of cases. It originated from the splenic artery in 37.6% of cases, common hepatic artery in 18.3% of cases, coeliac trunk in 11.9% of cases and the superior mesenteric artery in 23.9% of cases. Other rare origins were present in 2.77% of cases. Multiple dorsal pancreatic arteries were found in 1,7% of cases. There was no significant difference in the presence or origin of the dorsal pancreatic artery between anatomical and computed tomography based studies. The dorsal pancreatic artery is present in the vast majority of cases. Its origin and branching are highly variable. Multiplicity of the dorsal pancreatic artery is infrequent.

Background: Despite consensus supporting enhanced recovery programs, their full implementation in such a context is difficult due to conventional practices within various groups of professionals. The goal of the EUropean PErioperative MEdical Networking (EUPEMEN) project was to bring together the expertise and experience of national clinical professionals who have previously helped deliver major change programs in their countries and to use them to spread enhanced recovery after surgery protocols (ERAS) in Europe. The specific aim of this study is to present and discuss the key points of the proposed recommendations for colorectal surgery. Materials and methods: Five partners from university hospitals in four European countries developed the project as partners. Following a non-systematic review of the literature, the European consensus panel generated a list of recommendations for perioperative care in colorectal surgery. A list of recommendations was formulated and distributed to collaborators at each center to allow modifications or additional statements. These recommendations were then discussed in three consecutive meetings to share uniform ERAS protocols to be disseminated. Result: The working group developed (1) the EUPEMEN online platform to offer, free of charge, evidence-based standardized perioperative care protocols, learning activities, and assistance to health professionals interested in enhancing the recovery of their patients; (2) the preparation of the EUPEMEN Multimodal Rehabilitation manuals; (3) the training of the trainers to teach future teachers; and (4) the dissemination of the results in five multiplier events, one for each partner, to promote and disseminate the protocols. Conclusion: The EUPEMEN project allowed the sharing of the expertise of many professionals from four different European countries with the objective of training the new generations in the dissemination of ERAS protocols in daily clinical practice through a new learning system. This project was proposed as an additional training tool for all the enhanced recovery program teams.