46 research outputs found

    Self-identity discrepancy theory: Exploring returning South African Cuban-trained medical students sense of belonging

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    Background: The Nelson Mandela-Fidel Castro Collaboration programme (NMFCMC) between South Africa and Cuba was established in 1996. South African students, undergo five years of medical training in Cuba and finish the final eighteen months of training in South Africa. These students experience academic difficulties on their return. Methods: All twelve NMFCMC students enrolled at the University of KwaZulu-Natal in 2015 participated in this study. Data were elicited using focus group interviews, narrative interviews, found photovoice and the Collage Life Story Elicitation Technique. Results: Challenges faced by participants resulted in identity discrepancy, which in turn promoted unfavourable attitudes, affect, psychological and physical behaviours towards participants’ belongingness. Conclusion: Returning NMFCMC students experienced difficulties in assimilation due to identity discrepancies and frustrated sense of belonging. Focusing on reinforcing positive aspects of identity, and interpersonal relationships through moderating the tendency of local teachers and students to emphasise the “otherness” of the NMFCMC student is crucial

    Lymphocyte-Derived Exosomal MicroRNAs Promote Pancreatic ÎČ Cell Death and May Contribute to Type 1 Diabetes Development.

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    Type 1 diabetes is an autoimmune disease initiated by the invasion of pancreatic islets by immune cells that selectively kill the ÎČ cells. We found that rodent and human T lymphocytes release exosomes containing the microRNAs (miRNAs) miR-142-3p, miR-142-5p, and miR-155, which can be transferred in active form to ÎČ cells favoring apoptosis. Inactivation of these miRNAs in recipient ÎČ cells prevents exosome-mediated apoptosis and protects non-obese diabetic (NOD) mice from diabetes development. Islets from protected NOD mice display higher insulin levels, lower insulitis scores, and reduced inflammation. Looking at the mechanisms underlying exosome action, we found that T lymphocyte exosomes trigger apoptosis and the expression of genes involved in chemokine signaling, including Ccl2, Ccl7, and Cxcl10, exclusively in ÎČ cells. The induction of these genes may promote the recruitment of immune cells and exacerbate ÎČ cell death during the autoimmune attack. Our data point to exosomal-miRNA transfer as a communication mode between immune and insulin-secreting cells

    Ceacam1 separates graft-versus-host-disease from graft-versus-tumor activity after experimental allogeneic bone marrow transplantation.

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    BACKGROUND: Allogeneic bone marrow transplantation (allo-BMT) is a potentially curative therapy for a variety of hematologic diseases, but benefits, including graft-versus-tumor (GVT) activity are limited by graft-versus-host-disease (GVHD). Carcinoembryonic antigen related cell adhesion molecule 1 (Ceacam1) is a transmembrane glycoprotein found on epithelium, T cells, and many tumors. It regulates a variety of physiologic and pathological processes such as tumor biology, leukocyte activation, and energy homeostasis. Previous studies suggest that Ceacam1 negatively regulates inflammation in inflammatory bowel disease models. METHODS: We studied Ceacam1 as a regulator of GVHD and GVT after allogeneic bone marrow transplantation (allo-BMT) in mouse models. In vivo, Ceacam1(-/-) T cells caused increased GVHD mortality and GVHD of the colon, and greater numbers of donor T cells were positive for activation markers (CD25(hi), CD62L(lo)). Additionally, Ceacam1(-/-) CD8 T cells had greater expression of the gut-trafficking integrin α(4)ÎČ(7), though both CD4 and CD8 T cells were found increased numbers in the gut post-transplant. Ceacam1(-/-) recipients also experienced increased GVHD mortality and GVHD of the colon, and alloreactive T cells displayed increased activation. Additionally, Ceacam1(-/-) mice had increased mortality and decreased numbers of regenerating small intestinal crypts upon radiation exposure. Conversely, Ceacam1-overexpressing T cells caused attenuated target-organ and systemic GVHD, which correlated with decreased donor T cell numbers in target tissues, and mortality. Finally, graft-versus-tumor survival in a Ceacam1(+) lymphoma model was improved in animals receiving Ceacam1(-/-) vs. control T cells. CONCLUSIONS: We conclude that Ceacam1 regulates T cell activation, GVHD target organ damage, and numbers of donor T cells in lymphoid organs and GVHD target tissues. In recipients of allo-BMT, Ceacam1 may also regulate tissue radiosensitivity. Because of its expression on both the donor graft and host tissues, this suggests that targeting Ceacam1 may represent a potent strategy for the regulation of GVHD and GVT after allogeneic transplantation

    Assimilating South African medical students trained in Cuba into the South African medical education system: reflections from an identity perspective

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    Abstract Background In terms of the Nelson Mandela Fidel Castro Medical Collaboration programme, an agreement between the governments of South Africa and Cuba, cohorts of South African students receive their initial five years medical training at a Cuban university before returning to South Africa for a six to twelve months orientation before integration into the local final year class. It is common for these students to experience academic difficulty on their return. Frequently this is viewed merely as a matter of a knowledge deficit. Discussion We argue that the problem arises from a fundamental divergence in the outcomes of the Cuban and South African medical curricula, each of which is designed with a particular healthcare system in mind. Using the discrepancy theory of identity proposed by Higgins in 1987, we discuss the challenges experienced by the returning Nelson Mandela Fidel Castro Medical Collaboration students in terms of a potential crisis of identity and suggest interventions which may prove valuable in promoting academic success and successful integration. Conclusions Though providing additional training to address the gap in skills and knowledge in returning students is an important part of their successful reintegration, this could be insufficient on its own and must be complemented by a range of measures designed to ameliorate the discrepancies in identity which arise from the transition from one educational model to another

    the ebb-tidal delta of the venice lagoon,Italy

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    Very high-resolution seismic lines were collected offshore the Venice Lagoon in the framework of the Co.Ri.La'New very high resolution seismic methods to study the Venice Lagoon subsoil' project. The 140 km boomer profiles led to the identification of a convex-upward,lens-shaped body just outside the Lido inlet,one of the three lagoon inlets,which has been interpreted as an ebb-tidal delta.The comparison between the scismostratigraphic setting og this deposit, as revealed by the seismic lines,and the analyses of historicalbathymetric maps highlighted the key role of human interventions in the formation and evolution of the Lido inlet cbb-tidal delta.To preserve the lagoon environment but also to ensure a navigable way, human interventions at the Lidoinlet,performed since the fourteenth centtury, caused profound variations in the inlet dynamics,ldading to a progressive increase in the sediment dispersion from the lagoon interior towards the sea. The ebb-tidal delta of the Lido nilet is thus a very recent feature compared with the formation of the Venice lagoon and formed mainly as a consequence of the construction of the two jetties that have bound the inlet form AD 1886 to the present day
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