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Introduction: Anastomotic leaks (ALs) are serious postoperative complications. Current experimental studies designed to investigate leaks are based on acute intraoperative dehiscence of the anastomosis. Clinically, however, AL usually happens later in the postoperative course. Presented here is a clinically relevant colonic AL model in swine. Methods: Seventeen Yorkshire pigs were divided into 2 groups: the control group (n = 6) and the experimental group (n = 11). An enterotomy was performed on the descending colon and an end-to-end handsewn anastomosis was created in the groups. The proximal and distal ends of the suture were exteriorized and tied to a plastic tube. Subsequently, the suture was cut and pulled to induce breakdown of the anastomosis in the experimental group 3–4 h postoperatively. Study endpoints included behavioral changes, clinical assessment, laboratory indicators, and macroscopic indicators of leakage. Results: Leaks were successfully created in 8/11 of the experimental group animals and confirmed through exploratory relaparotomy. Seven of the experimental pigs showed complete anastomotic breakdown and one showed partial rupture. Fecal peritonitis and enteric spillage were observed macroscopically within the abdomen of the experimental pigs, confirming the presence of a leak. The remaining (3/11) experimental pigs did not experience those findings due to either a tamponade/containment by the abdominal wall or surrounding organs. Statistical significance (p < 0.05) was achieved between the experimental and control cohorts for laboratory and clinical indicators including fever, leukocytosis, and decreased blood potassium. Conclusion: This animal model generated postoperative induced leak in approximately three-quarters (8/11) of experimental pigs, allowing control over the time of leak onset to simulate clinical settings. [ABSTRACT FROM AUTHOR]

Phosphorylation of intrinsically disordered eIF4E binding proteins (4E-BPs) regulates cap-dependent translation by weakening their ability to compete with eIF4G for eIF4E binding within the translation initiation complex. We previously showed that phosphorylation of T37 and T46 in 4E-BP2 induces folding of a four-stranded beta-fold domain, partially sequestering the canonical eIF4E-binding helix. The C-terminal intrinsically disordered region (C-IDR), remaining disordered after phosphorylation, contains the secondary eIF4E-binding site and three other phospho-sites, whose mechanisms in inhibiting binding are not understood. Here we report that the domain is non-cooperatively folded, with exchange between beta strands and helical conformations. C-IDR phosphorylation shifts the conformational equilibrium, controlling access to eIF4E binding sites. The hairpin turns formed by pT37/pT46 are remarkably stable and function as transplantable units for phospho-regulation of stability. These results demonstrate how non-cooperative folding and conformational exchange leads to graded inhibition of 4E-BP2:eIF4E binding, shifting 4E-BP2 into an eIF4E binding-incompatible conformation and regulating translation initiation. Phosphorylation of eIF4E binding proteins (4E-BPs) controls their folding and regulates cap-dependent translation. Here, the authors show that phosphorylation of the C-terminal disordered region stabilizes the non-cooperatively folded 4E-BP domain to an eIF4E binding-incompatible state to control translation. [ABSTRACT FROM AUTHOR]