Background and purposeEffective mentorship is critical to the success of early stage investigators, and has been linked to enhanced mentee productivity, self-efficacy, and career satisfaction. The mission of the National Research Mentoring Network (NRMN) is to provide all trainees across the biomedical, behavioral, clinical, and social sciences with evidence-based mentorship and professional development programming that emphasizes the benefits and challenges of diversity, inclusivity, and culture within mentoring relationships, and more broadly the research workforce. The purpose of this paper is to describe the structure and activities of NRMN.Key highlightsNRMN serves as a national training hub for mentors and mentees striving to improve their relationships by better aligning expectations, promoting professional development, maintaining effective communication, addressing equity and inclusion, assessing understanding, fostering independence, and cultivating ethical behavior. Training is offered in-person at institutions, regional training, or national meetings, as well as via synchronous and asynchronous platforms; the growing training demand is being met by a cadre of NRMN Master Facilitators. NRMN offers career stage-focused coaching models for grant writing, and other professional development programs. NRMN partners with diverse stakeholders from the NIH-sponsored Diversity Program Consortium (DPC), as well as organizations outside the DPC to work synergistically towards common diversity goals. NRMN offers a virtual portal to the Network and all NRMN program offerings for mentees and mentors across career development stages. NRMNet provides access to a wide array of mentoring experiences and resources including MyNRMN, Guided Virtual Mentorship Program, news, training calendar, videos, and workshops. National scale and sustainability are being addressed by NRMN “Coaches-in-Training” offerings for more senior researchers to implement coaching models across the nation. “Shark Tanks” provide intensive review and coaching for early career health disparities investigators, focusing on grant writing for graduate students, postdoctoral trainees, and junior faculty.ImplicationsPartners from diverse perspectives are building the national capacity and sparking the institutional changes necessary to truly diversify and transform the biomedical research workforce. NRMN works to leverage resources towards the goals of sustainability, scalability, and expanded reach.

Morehouse School of Medicine chose to restructure its first year medical curriculum in 2005. The anatomy faculty had prior experience in integrating courses, stemming from the successful integration of individual anatomical sciences courses into a single course called Human Morphology. The integration process was expanded to include the other first year basic science courses (Biochemistry, Physiology, and Neurobiology) as we progressed toward an integrated curriculum. A team, consisting of the course directors, a curriculum coordinator and the Associate Dean for Educational and Faculty Affairs, was assembled to build the new curriculum. For the initial phase, the original course titles were retained but the lecture order was reorganized around the Human Morphology topic sequence. The material from all four courses was organized into four sequential units. Other curricular changes included placing laboratories and lectures more consistently in the daily routine, reducing lecture time from 120 to 90 minute blocks, eliminating unnecessary duplication of content, and increasing the amount of independent study time. Examinations were constructed to include questions from all courses on a single test, reducing the number of examination days in each block from three to one. The entire restructuring process took two years to complete, and the revised curriculum was implemented for the students entering in 2007. The outcomes of the restructured curriculum include a reduction in the number of contact hours by 28%, higher or equivalent subject examination average scores, enhanced student satisfaction, and a first year curriculum team better prepared to move forward with future integration.

A method is described for growing high-density micromass cultures of chick and mouse limb mesenchyme cells in 96-well microtiter plates (microT microM cultures). Rapid quantitative estimates of chondrogenic expression were obtained by automated spectrophotometric analysis of Alcian-blue-stained cartilage matrix extracts performed in the wells in which the cells had been grown. Quantitative estimates of myogenic expression were obtained similarly using anti-sarcomere myosin monoclonal antibody and modified ELISA techniques. This microT microM-ELISA method may be adapted for use with other antigens for which specific antibodies are available. These methods were used to compare cartilage and muscle differentiation in 1 to 4 d microT microM cultures grown in serum-containing (SCM) and defined (DM) media. The DM contains minimal additives (insulin, hydrocortisone, and in some cases, ascorbate or transferrin) and supports both chondrogenesis and myogenesis. The colorimetric analyses agree well with the morphologic appraisal of chondrogenesis and myogenesis. Similar numbers of cartilage nodules formed in all cultures, but in DM the nodules failed to enlarge; explaining the reduced matrix synthesis in DM as compared with SCM, and suggesting that nodule enlargement is a discrete, serum-dependent step. Studies of selected additives to DM show that transferrin enhances myogenesis, ascorbic acid enhances chondrogenesis, and retinoic acid inhibits chondrogenesis. Together, the microT microM system, in situ colorimetric assays of chondrogenesis and myogenesis, and DM will allow rapid prescreening of teratogens and screening of various bioactive compounds (e.g., hormones, growth factors, vitamins, adhesion factors) for effects on limb mesenchymal cell differentiation.

Anabolic agents are useful tools for probing the mechanisms by which muscle fibers perceive and respond to disuse. β₂-Adrenergic agonists exert protective, and/or reparative, effects on atrophying muscle tissue. The effects of one such agent, clenbuterol (Cb), were examined on muscle mass, total protein content, and myofibrillar protein content in selected hindlimb muscles [adductor longus (ADL), extensor digitorum longus (EDL), plantaris (PLAN), soleus (SOL)] of mature male rats, under different loading conditions. Pair-fed rats were divided into four experimental groups: vehicle- and Cb-treated nonsuspended, vehicle- and Cb-treated hindlimb suspended (HLS). Experiments lasted 14 days, during which the rats received subcutaneous injections of 1 mg/kg Cb or 1 ml/kg vehicle. HLS induced significant atrophy in all muscles, except the EDL, in a generally fiber type-related pattern. However, myofibrillar protein content was affected in a more regional pattern. Cb treatment of nonsuspended rats induced hypertrophy in all muscles, in a generally uniform pattern. However, myofibrillar protein content was affected in a more fiber type-related pattern. Cb treatment of HLS rats reduced or eliminated HLS-induced atrophy in all muscles, in a muscle-specific pattern. Overall, the ADL and SOL were most susceptible to HLS-induced atrophy. The PLAN had the greatest magnitude of Cb-induced sparing of atrophy. The results show that, in mature male rats, Cb exerts anabolic effects that are load-dependent and muscle-specific. Responses to this drug cannot be reliably predicted by fiber-type composition alone.