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Background and aims: Biliary lipid absorption by the gall bladder mucosa and the cholesterol content of the gall bladder wall appear to play a role in cholesterol gall stone formation. As the scavenger receptor class B type I (SR-BI) regulates cellular cholesterol uptake, we studied its expression in human and murine gall bladders, its regulation by increased biliary lipid content, and its role in gall stone formation. Methods and results: Using immunohistochemistry, SR-BI was found in the apical domain of human gall bladder epithelial cells. Immunoblotting of isolated membranes from gall bladder epithelial cells showed a specific signal for the 82 kDa SR-BI protein. In C57BL/6 mice, SR-BI was also found in the gall bladder epithelium. Using western blot analysis, an inverse relationship was observed between biliary cholesterol concentration and SR-BI expression in murine gall bladder mucosa. By comparing lithogenic diet fed wild-type and SR-BI deficient mice, gall bladder wall cholesterol content and gall stone formation were not found to be dependent on SR-BI expression. Conclusions: (i) SR-BI is expressed in both human and murine gall bladder epithelium; (ii) biliary cholesterol hypersecretion is associated with decreased gall bladder SR-BI expression in mice; and (iii) murine SR-BI is not essential in controlling gall bladder wall cholesterol content and gall stone formation during diet induced cholelithiasis.

In a murine model of GSD, EZET prevented gallstone formation by reducing intestinal cholesterol absorption and increasing bile salt-dependent and -independent bile flow. EZET could be useful in preventing GSD disease in susceptible patients.

Ntcp localizes in membrane rafts and its localization and function are regulated by membrane cholesterol content. This may serve as a novel regulatory mechanism of bile salt transport in liver.

Caveolins are cholesterol-binding proteins involved in the regulation of several intracellular processes, including cholesterol transport. Because hepatocytes express caveolin-1 and caveolin-2, these proteins might modulate hepatic lipid metabolism and biliary lipid secretion. Our aim was to investigate the potential physiologic role of caveolins in hepatic cholesterol and bile salt (BS) metabolism and transport using adenoviral gene transfer. C57BL/6 mice were infected with recombinant human caveolin-1 and caveolin-2 adenoviruses. Mice infected with adenovirus lacking the transgene were used as controls. Hepatic caveolin expression was evaluated by immunochemical methods. Reverse-transcription polymerase chain reaction (RT-PCR) and immunoblotting were used to assess messenger RNA (mRNA) levels and protein mass of BS transporters (sodium taurocholate cotransporting polypeptide [Ntcp] and bile salt export pump [Bsep]). Serum, liver, biliary, and fecal biochemical determinations and BS maximal secretory rate (SRm) were performed by standard methods. Ad.Cav-1-and Ad.Cav-2-infected mice exhibited a 10-and 7-fold increase in hepatic caveolin-1 and caveolin-2 protein expression, respectively. Caveolin-1-overexpressing mice had a significant increase in plasma high-density lipoprotein (HDL) cholesterol and hepatic free cholesterol content, whereas total plasma cholesterol and triglyceride levels remained unchanged. Hepatic caveolin-1 and/or caveolin-2 overexpression significantly increased bile flow and secretion of all biliary lipids. Caveolin-1-overexpressing mice showed a 2.5-fold increase in taurocholate (TC) SRm, indicating increased canalicular BS transport capacity. BS pool size and fecal BS excretion remained within the normal range in mice with Cav-1 overexpression. No changes were seen in the protein mass of BS transporters Ntcp and Bsep. In conclusion, our findings indicate that caveolins may play an important role in regulating hepatic BS and cholesterol metabolism.

The most common postoperative complications of total gastrectomy are esophagojejunal anastomotic leakage and subphrenic abscess. These complications are a cause of morbility and mortality, relaparotomy, and longer postoperative stay. The use of abdominal drains is useful for the early diagnosis and management of anastomotic leaks. The aim of this study was to analyze our experience with total gastrectomy for gastric cancer in patients with and without abdominal drains, and to evaluate the results regarding postoperative morbidity, postoperative hospital stay, postoperative days for oral intake, relapatorotomy and mortality. This prospective and randomized study examines the results in 60 consecutive patients (43 males and 17 females) with gastric cancer who underwent total gastrectomy in the Regional Clinical Hospital of Concepción, Chile, between 2000 and 2003. Patients were divided into two groups: group I (without drains) and group II (two drains). We found 31 patients in group I and 29 patients in group II. The mean length of postoperative stay was 12.9 days in group I and 18.8 days in group II (p = 0.0242, s.). Morbidity was 9.7% in group I and 37.9% in group II (p = 0.0242, s.). Re-explorations were more frequent in group II (24.1%) versus group I (9.7%) (p = 0.1239, n.s.). Postoperative days for oral intake were 9.4 in group I and 12.8 in group II (p = 0.0514, n.s.) Mortality was 0% in group I and 3.4% in group II (p = 0.4833, n.s.). In our experience, morbidity and postoperative hospital stay were statistically higher in the group of patients with abdominal drains.

Objective: To compare the acquisition of basic procedural suture skills in medical students according to practical teaching by surgeons versus peers. Methods: Pre-experimental study before and after, a practical suture workshop was held for 46 eighth-semester medical students of the University of Concepción between November and December 2017. Participants were randomly distributed in such a way that half of them were trained by sub-specialists surgeons and the other by medical students (suture instructor). The continuous and discontinuous suture was evaluated on the biological model using the "the objective structured assessment of technical skills" (OSATS) scale. A satisfaction survey was applied at the end of the workshop. Results of the OSATS scale are compared before and after the workshop, SPSS24 ® was used for statistical analysis by Student's t-test for independent samples, considering significant p < 0.05. Results: Both groups progressed significantly on the OSATS scale (13.0 vs. 26.0, p < 0.001 for surgeons and 16.8 vs. 27.9, p < 0.001 for suture instructors) when comparing pre-versus post-workshop results, respectively. The post-workshop results do not show significant differences. Conclusion: Participants acquire basic surgical suture skills evidencing significant progression and similar degree of satisfaction regardless of whether they are trained by subspecialist surgeons or trained peers.