Near-Peer Emergency Medicine for Medical Students in Port-au-Prince, Haiti: An Example of Rethinking Global Health Interventions in Developing Countries

Background: During a 3-year time frame, a partnership between medical trainees in Haiti and the United States was forged with the objective of implementing an emergency response skills curriculum at a medical school in Port-au-Prince. The effort sought to assess the validity of a near-peer, bidirectional, cross-cultural teaching format as both a global health experience for medical students and as an effective component of improving medical education and emergency response infrastructure in developing countries such as Haiti. Method: Medical students and emergency medicine (EM) residents from a North American medical school designed and taught a module on emergency response skills in PAP and certified medical students in basic cardiac life support (BLS) over 2 consecutive years. Five-point Likert scale self-efficacy (SE) surveys and multiple-choice fund of knowledge (FOK) assessments were distributed pre- and postmodule each year and analyzed with paired 't'tests and longitudinal follow-up of the first cohort. Narrative evaluations from participants were collected to gather feedback for improving the module. Findings: Challenges included bridging language barriers, maintaining continuity between cohorts, and adapting to unexpected schedule changes. Overall, 115 students were certified in BLS with significant postcurriculum improvements in SE scores (2.75 ± 0.93 in 2013 and 2.82 ± 1.06 in 2014; 'P' < 0.001) and FOK scores (22% ± 15% in 2013 and 41% ± 16% in 2014; 'P' < 0.001). Of 24 Haitian students surveyed at 1-year follow-up from the 2013 cohort, 7 (29.3%) reported using taught skills in real-life situations since completing the module. The US group was invited to repeat the project for a third year. Conclusions: Near-peer, cross-cultural academic exchange is an effective method of medical student–centered emergency training in Haiti. Limitations such as successfully implementing sustainability measures, addressing cultural differences, and coordinating between groups persist. This scalable, reproducible, and mutually beneficial collaboration between North American and Haitian medical trainees is a valid conduit for building Haiti's emergency response infrastructure and promoting global health

Brain metastases in melanoma: Roles of neurotrophins1

Brain metastasis, which occurs in 20% to 40% of all cancer patients, is an important cause of neoplastic morbidity and mortality. Successful invasion into the brain by tumor cells must include attachment to microvessel endothelial cells, penetration through the blood-brain barrier, and, of relevance, a response to brain survival and growth factors. Neurotrophins (NTs) are important in brain-invasive steps. Human melanoma cell lines express low-affinity NT receptor p75NTR in relation to their brain-metastatic propensity with their invasive properties being regulated by NGF, or nerve growth factor, the prototypic NT. They also express functional TrkC, the putative receptor for the invasion-promoting NT-3. In brain-metastatic melanoma cells, NTs promote invasion by enhancing the production of extracellular matrix (ECM)-degradative enzymes such as heparanase, an enzyme capable of locally destroying both ECM and the basement membrane of the blood-brain barrier. Heparanase is an endo-β-d-glucuronidase that cleaves heparan sulfate (HS) chains of ECM HS proteoglycans, and it is a unique metastatic determinant because it is the dominant mammalian HS degradative enzyme. Brain-metastatic melanoma cells also produce autocrine/paracrine factors that influence their growth, invasion, and survival in the brain. Synthesis of these factors may serve to regulate NT production by brain cells adjacent to the neoplastic invasion front, such as astrocytes. Increased NT levels have been observed in tumor-adjacent tissues at the invasion front of human brain melanoma. Additionally, astrocytes may contribute to the brain-metastatic specificity of melanoma cells by producing NT-regulated heparanase. Trophic, autocrine, and paracrine growth factors may therefore determine whether metastatic cells can successfully invade, colonize, and grow in the CNS