Satellite cell depletion in degenerative skeletal muscle

Adult skeletal muscle has the striking ability to repair and regenerate itself after injury. This would not be possible without satellite cells, a subpopulation of cells existing at the margin of the myofiber. Under most conditions, satellite cells are quiescent, but they are activated in response to trauma, enabling them to guide skeletal muscle regeneration. In degenerative skeletal muscle states, including motor nerve denervation, advanced age, atrophy secondary to deconditioning or immobilization, and Duchenne muscular dystrophy, satellite cell numbers and proliferative potential significantly decrease, contributing to a diminution of skeletal muscle's regenerative capacity and contractility. This review will highlight the fate of satellite cells in several degenerative conditions involving skeletal muscle, and will attempt to gauge the relative contributions of apoptosis, senescence, impaired proliferative potential, and host factors to satellite cell dysfunction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44390/1/10495_2004_Article_5150572.pd

Likert scales: how to (ab)use them?

No abstract available

Double free-flap reconstruction of massive defects involving the lip, chin, and mandible

Two patients with massive, composite defects of the total lower lip, chin, and anterior mandible underwent double free-flap reconstruction. A fibular osteoseptocutaneous flap was used to reconstruct the mandible and floor of the mouth and a radial forearm fasciocutaneous composite flap, including the palmaris longus tendon, was used for total lower lip and chin reconstruction. Postoperatively, both patients had acceptable cosmesis, were orally competent, and recovered adequate mandibular function. Double free-flap reconstruction is indicated only in those circumstances in which composite tissue requirements or massive tissue defects preclude reconstruction with a single free-tissue transfer. © 1998 Wiley-Liss, Inc. MICROSURGERY 18:372–378, 1998Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38479/1/6_ftp.pd

Staged inset of free flaps for complex microsurgical head and neck reconstruction to ensure total flap survival

IntroductionMicrosurgical reconstruction of complex head and neck defects often requires reliable tissue in multiple spatial configurations to achieve good functional and aesthetic outcomes. In addition to robust perforators, flap inset and wound closure require great caution to minimize complications especially in the presence of trismus with limited space for inset. This report describes the technique and results of our staged approach to flap inset which increases the chance of total flap survival in complex head and neck reconstructions.MethodsFrom February 2010 to August 2016, a total of 53 patients were identified via a retrospective chart review. Patients who were suspected to have a high risk of vascular compromise and subsequently underwent complex head and neck reconstruction with staged inset of anterolateral thigh (ALT) flaps were included. The flap was inset only partially at the recipient site initially with fewer sutures. At a second stage, after neovascularization from surrounding tissue was established, the flap was partially elevated, divided and mobilized on its own pedicle for definitive inset.ResultsFiftyâ one patients had complete survival of flaps and had uneventful postoperative course. Six cases required immediate reâ exploration to release wound tension or reposition the pedicle. Of these, 4 flaps were salvaged, 2 failed due to small perforators despite anastomosis revision. The flap survival rate was 96.2% and the average time between 2 stages was 24â days (range, 21â 28).ConclusionStaged flap inset can improve free flap survival in complex head and neck reconstructions.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146598/1/micr30370.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146598/2/micr30370_am.pd

Termino-lateral neurorrhaphy: The functional axonal anatomy

The goal of this study was to determine the functional axonal anatomy of a termino-lateral neurorrhaphy (TLN). We hypothesize that axons populating a TLN must relinquish functional connections with their original targets prior to establishing new connections via the TLN. Two-month-old F344 rats underwent a TLN between the left peroneal nerve and a nerve graft tunneled to the contralateral hindlimb. Three months postoperatively, an end-to-end neurorrhaphy was performed between the nerve graft and the right peroneal nerve. Four months after the second operation, contractile properties and electromyographic (EMG) signals were measured in the bilateral hindlimbs. Left peroneal nerve stimulation proximal to the TLN site resulted in bilateral extensor digitorum longus (EDL) and tibialis anterior (TA) muscle contractions, with significantly lower forces on the side reinnervated by TLN. Evoked EMGs demonstrated that the right and left hindlimb musculature were electrically discontinuous following TLN. These data support our hypothesis that axons can form functional connections via a TLN, but they must first relinquish functional connections with their original targets. © 2000 Wiley-Liss, Inc. MICROSURGERY 20:6–14 2000Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34923/1/2_ftp.pd

Factors affecting residency rank-listing: A Maxdiff survey of graduating Canadian medical students

<p>Abstract</p> <p>Background</p> <p>In Canada, graduating medical students consider many factors, including geographic, social, and academic, when ranking residency programs through the Canadian Residency Matching Service (CaRMS). The relative significance of these factors is poorly studied in Canada. It is also unknown how students differentiate between their top program choices. This survey study addresses the influence of various factors on applicant decision making.</p> <p>Methods</p> <p>Graduating medical students from all six Ontario medical schools were invited to participate in an online survey available for three weeks prior to the CaRMS match day in 2010. Max-Diff discrete choice scaling, multiple choice, and drop-list style questions were employed. The Max-Diff data was analyzed using a scaled simple count method. Data for how students distinguish between top programs was analyzed as percentages. Comparisons were made between male and female applicants as well as between family medicine and specialist applicants; statistical significance was determined by the Mann-Whitney test.</p> <p>Results</p> <p>In total, 339 of 819 (41.4%) eligible students responded. The variety of clinical experiences and resident morale were weighed heavily in choosing a residency program; whereas financial incentives and parental leave attitudes had low influence. Major reasons that applicants selected their first choice program over their second choice included the distance to relatives and desirability of the city. Both genders had similar priorities when selecting programs. Family medicine applicants rated the variety of clinical experiences more importantly; whereas specialty applicants emphasized academic factors more.</p> <p>Conclusions</p> <p>Graduating medical students consider program characteristics such as the variety of clinical experiences and resident morale heavily in terms of overall priority. However, differentiation between their top two choice programs is often dependent on social/geographic factors. The results of this survey will contribute to a better understanding of the CaRMS decision making process for both junior medical students and residency program directors.</p