Microparticles from stored red blood cells activate neutrophils and cause lung injury after hemorrhage and resuscitation.

Item does not contain fulltextBACKGROUND: Transfusion of stored blood is associated with increased complications. Microparticles (MPs) are small vesicles released from RBCs that can induce cellular dysfunction, but the role of RBC-derived MPs in resuscitation from hemorrhagic shock is unknown. In the current study, we examined the effects of RBC-derived MPs on the host response to hemorrhage and resuscitation. STUDY DESIGN: MPs were isolated from murine packed RBC units, quantified using flow cytometry, and injected into healthy mice. Separate groups of mice underwent hemorrhage and resuscitation with and without packed RBC-derived MPs. Lungs were harvested for histology and neutrophil accumulation and assessed by myeloperoxidase content. Human neutrophils were treated with human RBC-derived MPs and CD11b expression, superoxide production, and phagocytic activity were determined. RESULTS: Stored murine packed RBC units contained increased numbers of RBC-derived MPs compared with fresh units. Hemorrhaged mice resuscitated with MPs demonstrated substantially increased pulmonary neutrophil accumulation and altered lung histology compared with mice resuscitated without MPs. Intravenous injection of MPs into normal mice resulted in neutrophil priming, evidenced by increased neutrophil CD11b expression. Human neutrophils treated with RBC-derived MPs demonstrated increased CD11b expression, increased superoxide production, and enhanced phagocytic ability compared with untreated neutrophils. CONCLUSIONS: Stored packed RBC units contain increased numbers of RBC-derived MPs. These MPs appear to contribute to neutrophil priming and activation. The presence of MPs in stored units can be associated with adverse effects, including lung injury, after transfusion.1 april 201

Surgeons underestimate their influence on medical students entering surgery.

Item does not contain fulltextBACKGROUND: Positive surgical role models influence medical students to pursue a career in surgery. However, the perception by role models of their own effectiveness has yet to be examined. In this study, we evaluated the influence of surgical role models on medical student career choice, and how these role models perceive themselves. METHODS: We distributed a voluntary and anonymous survey to third-year medical students, general surgery resident applicants, general surgery residents, and attending surgery faculty during the 2010-2011 academic year. We performed statistical analysis using the chi-square and Cochran-Mantel-Haenszel tests (P < 0.05 was significant). RESULTS: Medical students and resident applicants agreed that faculty and residents are important in shaping the career paths of students. The applicants were more likely to agree than were students that clerkship role models (P = 0.0049) and mentors (P = 0.0035) affected their interest in surgery. The applicants were also more likely to agree than the students that attending surgeons (P = 0.0004), senior (P = 0.0019) and junior (P = 0.0028) surgery residents served as positive role models. Although the surgical faculty and residents agreed with the students that each level of the surgical team served as positive role models, they did not agree as strongly with the students that they have an important role in shaping students' career path (P < 0.0001). CONCLUSIONS: Surgical faculty and residents serve as positive role models for medical students. They have an essential role in shaping students' career paths and should be more cognizant of their influence, which may draw a student toward or lead them away from the field of surgery.1 oktober 201

Sodium arsenite reduces severity of dextran sulfate sodium-induced ulcerative colitis in rats

The histopathological features and the associated clinical findings of ulcerative colitis (UC) are due to persistent inflammatory response in the colon mucosa. Interventions that suppress this response benefit UC patients. We tested whether sodium arsenite (SA) benefits rats with dextran sulfate sodium (DSS)-colitis. The DSS-colitis was induced by 5% DSS in drinking water. SA (10 mg/kg; intraperitoneally) was given 8 h before DSS treatment and then every 48 h for 3 cycles of 7, 14 or 21 d. At the end of each cycle rats were sacrificed and colon sections processed for histological examination. DSS induced diarrhea, loose stools, hemoccult positive stools, gross bleeding, loss of body weight, loss of epithelium, crypt damage, depletion of goblet cells and infiltration of inflammatory cells. The severity of these changes increased in the order of Cycles 1, 2 and 3. Treatment of rats with SA significantly reduced this severity and improved the weight gain