The role of thrombin and thrombin receptors in ischemic, hemorrhagic and traumatic brain injury: deleterious or protective?

In the last two decades it has become apparent that thrombin has many extravascular effects that are mediated by a family of protease-activated receptors (PARs). PAR-1, -3 and -4 are activated via cleavage by thrombin. The importance of extravascular thrombin in modulating ischemic, hemorrhagic and traumatic injury in brain has recently become clear. Thus, in vitro , thrombin at low concentration protects neurons and astrocytes from cell death caused by a number of different insults. In vivo , pretreating the brain with a low dose of thrombin (thrombin preconditioning), attenuates the brain injury induced by a large dose of thrombin, an intracerebral hemorrhage or by focal cerebral ischemia. Thrombin may also be an important mediator of ischemic preconditioning. In contrast, high doses of thrombin kill neurons and astrocytes in vitro and cause disruption of the blood–brain barrier, brain edema and seizures in vivo . This review examines the role of thrombin in brain injury and the molecular mechanisms and signaling cascades involved.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66277/1/j.1471-4159.2003.01268.x.pd

Teambuilding and Leadership Training in an Internal Medicine Residency Training Program: Experience with a One-day Retreat

OBJECTIVE: The purpose of this report is to describe and evaluate the impact of a 1-day retreat focused on developing leadership skills and teambuilding among postgraduate year 1 residents in an internal medicine residency. METHOD: A group of organizers, including members of the staff, the chief medical residents, administrative individuals in the residency office, and an internal organizational development consultant convened to organize an off-site retreat with activities that would provide experiential learning regarding teamwork and leadership, including a “reef survival exercise” and table discussions regarding the characteristics of ideal leaders. In addition, several energizing activities and recreational free time was provided to enhance the interaction and teamwork dimensions of the retreat. To evaluate the impact of the retreat, attendees completed baseline and follow-up questionnaires regarding their experience of the retreat. RESULTS: Attendees universally regarded the retreat as having value for them. Comparison of baseline to postretreat responses indicated that attendees felt that the retreat enhanced their abilities to be better physicians, resident supervisors, and leaders. Follow-up responses indicated significant increases in attendees’ agreement that good leaders challenge the process, make decisions based on shared visions, allow others to act, recognize individual contributions, and serve as good role models. Results on the survival exercise indicated a high frequency with which team-based decisions surpassed individual members’ decisions, highlighting the importance and value of teamwork to attendees. CONCLUSIONS: Our main findings were that: participants universally found this 1-day retreat beneficial in helping to develop teamwork and leadership skills and the experiential learning aspects of the retreat were more especially highly rated and highlighted the advantages of teamwork. In the context that this 1-day retreat was deemed useful by faculty and residents alike, further study is needed to assess the impact of this learning on actual clinical practice and the durability of these lessons