The risk of POI seems increased in patients with preoperative COPD and patients with an ileostomy, especially in men. Consideration of these factors could be important for the prevention and treatment of POI.

The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that mediates the biological and toxic effects of a wide variety of structurally diverse chemicals, including the toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While significant interspecies differences in AHR ligand binding specificity, selectivity and response have been observed, the structural determinants responsible have not been determined and homology models of the AHR ligand-binding domain (LBD) are available for only a few species. Here we describe the development and comparative analysis of homology models of the LBD of sixteen AHRs from twelve mammalian and nonmammalian species and identify the specific residues contained within their ligand binding cavities. The ligand-binding cavity of the fish AHR exhibits differences from mammalian and avian AHRs, suggesting a slightly different TCDD binding mode. Comparison of the internal cavity in the LBD model of zebrafish (zf) AHR2, which binds TCDD with high affinity, to that of zfAHR1a, which does not bind TCDD, revealed that the latter has a dramatically shortened binding cavity due to the side chains of three residues (Tyr296, Thr386, His388) that reduce the internal space available to TCDD. Mutagenesis of two of these residues in zfAhR1a to those present in zfAHR2 (Y296H, T386A) restored the ability of zfAHR1a to bind TCDD and to exhibit TCDD-dependent binding to DNA. These results demonstrate the importance of these two amino acids and highlight the predictive potential of comparative analysis of homology models from diverse species. The availability of these AHR LBD homology models will facilitate in depth comparative studies of AHR ligand binding and ligand-dependent AHR activation and provide a novel avenue to examine species specific differences in AHR responsiveness.

Diverticulitis in young patients does not have a particularly aggressive course and the risk of recurrence is similar to that of older patients.

No abstract

Placement of a prosthetic mesh by the laparoscopic approach following the modified Sugarbaker technique is safe and effective in the prevention of PH, reducing significantly the incidence of PH.

No abstract

Specialization in colorectal surgery has a significant influence on morbidity, mortality, and anastomotic dehiscence after emergency operations.

RPA can be safely performed without adding morbidity and mortality in cases of diffuse diverticular peritonitis. HP should be reserved only for hemodynamically unstable or high-risk patients. Specialization in colorectal surgery improves mortality and raises the percentage of one-stage procedures.