Nerve-associated Schwann cell precursors contribute extracutaneous melanocytes to the heart, inner ear, supraorbital locations and brain meninges.

Melanocytes are pigmented cells residing mostly in the skin and hair follicles of vertebrates, where they contribute to colouration and protection against UV-B radiation. However, the spectrum of their functions reaches far beyond that. For instance, these pigment-producing cells are found inside the inner ear, where they contribute to the hearing function, and in the heart, where they are involved in the electrical conductivity and support the stiffness of cardiac valves. The embryonic origin of such extracutaneous melanocytes is not clear. We took advantage of lineage-tracing experiments combined with 3D visualizations and gene knockout strategies to address this long-standing question. We revealed that Schwann cell precursors are recruited from the local innervation during embryonic development and give rise to extracutaneous melanocytes in the heart, brain meninges, inner ear, and other locations. In embryos with a knockout of the EdnrB receptor, a condition imitating Waardenburg syndrome, we observed only nerve-associated melanoblasts, which failed to detach from the nerves and to enter the inner ear. Finally, we looked into the evolutionary aspects of extracutaneous melanocytes and found that pigment cells are associated mainly with nerves and blood vessels in amphibians and fish. This new knowledge of the nerve-dependent origin of extracutaneous pigment cells might be directly relevant to the formation of extracutaneous melanoma in humans.

Using targeting to recruit men and women of color into a behavioral weight loss trial.

BACKGROUND: The majority of participants in weight loss trials are non-Hispanic White women, while men and women of color are underrepresented. This study presents data obtained from non-targeted and targeted recruitment approaches in a trial of behavioral weight loss programs to (1) describe the yields from each approach and (2) compare the demographics, weight control histories, and study involvement of samples recruited by each approach. METHODS: Data for this observational study include source of recruitment, demographic information, weight loss experiences (e.g., lifetime weight loss, current weight loss behaviors), and completion of the 6-month assessment visit. RESULTS: Men comprised 14.2% of participants who responded to non-targeted recruitment efforts, while targeted efforts yielded 50.4% men. Similarly, people of color comprised 12.8% of those who responded to non-targeted approaches, whereas targeted recruitment methods yielded 47.2% people of color. Men recruited through targeted methods were younger (p = 0.01) than men recruited through non-targeted means but were otherwise similar. Women of color recruited through targeted methods reported use of fewer weight loss strategies relative to women of color recruited through non-targeted means (p = 0.006) but were otherwise similar. There were no differences by recruitment method on retention to the study. CONCLUSIONS: Using targeted recruitment methods increased the ethnic and gender diversity of the recruited sample without reducing study retention. This targeting also increased the enrollment of women with less weight loss experience who may not have otherwise sought out a weight loss program. Developing and implementing a targeted recruitment plan should be considered early in the clinical trial development process. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02368002. Registered on 20 February 2015.

Education of foreign community general practitioners and its enlightenment / 中华医学教育探索杂志

Community medical staff construction centered on general practitioner is a basic engineering to improve the quality and enhance the level of basic medical and health service system.The developed western countries have up-to-date experiences in general and further education of community general practitioners.By combining these experiences with China's national conditions,this thesis explored the 'targeted recruitment-employment mode' for general practitioners and discussed the reform in curriculum,teaching content and teaching organization in order to promote the practice base construction and further education after graduation as well as to cultivate all-around talents of high quality who can meet the requirements of the basic-level medical work.