Mutations that affect basal levels of myosin regulatory light chain (RLC) phosphorylation have been implicated in the development of familial hypertrophic cardiomyopathy. Regulatory light chains, one of the two light chain components of the myosin molecule, play a significant role in stabilizing the myosin lever arm during force transmission. While phosphorylation of RLCs by myosin light chain kinases have been implicated in modulating force development in cardiac muscle, their detailed mechanism and precise role in cardiac function is not well understood as compared to their well-studied counterparts in skeletal muscle. In this study, the effects of RLC phosphorylation on cardiac force generation were assessed by comparing force generation results from wild type mice (̃30% phosphorylated RLC) with those from a non- phosphorylatable RLC knock-in strain MLC2v (̃0% phosphorylated RLC). Intact papillary muscles were isolated from mouse hearts, and placed within a tissue culture chamber system that enabled measurement of force within a physiologic environment, i.e. with controlled oxygen and superfusate delivery. This system enabled measurements of force generation before and after muscles were subject to an isometric stretch protocol (90% Lmax). RLC phosphorylation at baseline had no statistically significant effect on systolic force generation; however there was a profound difference in active stress between wild-type and MLC2v knock-in papillary muscles after isometric stretch. These results suggest that RLC phosphorylation potentiates the immediate force response to cardiac lengthening, i.e. the Frank Starling mechanism; therefore RLC phosphorylation may involve cross-bridge dynamics and compensatory protein phosphorylation mechanisms that are more complex then previously assumed.

Objective

This study assessed the impact of a Leadership Fellowship, sponsored by the American Psychiatric Association (APA) and APA Foundation, on the careers of psychiatry residents and examined the influence of gender and year of Fellowship completion. This 2-year program for residents offered multiple opportunities to interact with professional leaders at various levels.

Methods

A retrospective online survey of alumni of the APA Leadership Fellowship, who had completed this Fellowship between 2003 and 2019, was conducted.

Results

Out of the 93 psychiatrists who were sent the survey, 59 alumni responded (60.8% response rate). Most respondents had remained involved with organized psychiatry groups and 80% held leadership positions. Respondents reported high levels of satisfaction with the APA Fellowship experience, noting the importance of peer networking. Overall, male and female respondents were similar in their subsequent leadership positions and satisfaction with the survey. Similarly, Fellows who completed the Fellowship in 2003-2015 had responses about the experience that were largely similar to those in the 2016-2019 cohort that had not yet completed their residency.

Conclusion

A vast majority of alumni of the APA Leadership Fellowship had become leaders in their workplace or organized psychiatry groups. The leadership-focused career development programs for psychiatry trainees are important avenues to develop a diverse cohort of future leaders in psychiatry.