Tcf/Lef transcription factors play an important role in mediating canonical Wnt signaling. When bound by ␤-catenin, Tcf/Lef proteins either activate or de-repress gene transcription. In zebrafish, four members have been identified: Lef1, Tcf3, Tcf3b, and Tcf4. Here, we report the cloning and expression of the tcf7 gene. Forms of Tcf7 expressed in the embryo contain two highly conserved regions: an N-terminal ␤-catenin binding domain and a C-terminal HMG domain. Tcf7 lacks a putative Groucho corepressor binding site, suggesting that, like Lef1, it functions as a transcriptional activator. We isolated three C-terminal splice variants of tcf7 corresponding to human B, C, and D isoforms. tcf7 expression overlaps with lef1 expression maternally, in the tail bud, fin buds, and paraxial mesoderm, and we expect that the two genes function redundantly in those areas. tcf7 is also expressed in nonoverlapping areas such as the prechordal mesoderm, dorsal retina, and median fin fold, suggesting unique functions. Developmental Dynamics 233: 233-239, 2005.

The diverse exercise goals of the aging population present several challenges to physicians. Whereas some Masters athletes aim to set personal time records, sedentary elderly persons may look to exercise to help maintain independence and combat functional decline. This review article examines the common cardiovascular and neuromuscular physiological changes associated with aging and how regular exercise is used to improve physiological parameters and functional abilities. Exercise precautions specific to the elderly population are discussed. Exercise recommendations for persons with osteoarthritis and after joint arthroplasty also are presented.

Among athletes, dancers sustain one of the highest rates of injury. Core muscle strength has been proposed as a factor for reducing injury incidence among athletic populations; however, dancers’ core strength and its relation to injury has not been well studied. This study hypothesized that during a pre-semester screening examination collegiate dancers who performed better during core strength assessments would report a lower prevalence of dance related injury. Thirty-six dancers (34 female, 2 male; mean age: 20.8 ± 1.8 years) were recruited from two college-level dance programs. Participants responded to a survey concerning their dance training (mean: 12.8 ± 4.3 years) and injury history. Hip joint passive range of motion testing was performed followed by dynamometer measurements of hip abduction (HAB) and hip external rotation (HER) strength. Dancers also underwent testing of anterior, lateral, and posterior core muscle strength. To assess functional integration of core strength, three pilot screening movements were performed. Thirty-one dancers (86.1%) reported a prior history of at least one dance related injury, and 15 (41.7%) had current injuries (mean: 1.8 ± 1.27 anatomic areas). More than half of the participants (51.4%) demonstrated significant (> 15%) side-to-side variability in HAB strength, and 32.4% demonstrated variability in HER, but neither these nor any of the other measurements of core strength (including both static and dance specific protocols) were significantly associated with current or previous dance injury. Asymmetric hip internal rotation was associated with prior but not current dance related injury, with previously injured dancers demonstrating a 10° difference between right and left limbs. While core strength remains an important component of dance training, this study was unable to show a significant correlation between the results on selected tests and current or prior dance related injuries. This may be due to limitations in study design. However, the authors continue to support medical providers in recommending core strengthening exercises as part of dancers’ overall fitness training to optimize injury prevention.

Although dancers did not perceive physicians to be first-line treatment providers for DRIs, these perceptions about physicians were poorly correlated with use. Instead, injured dancers' health care-seeking behaviors were more likely related to relatively decreased barriers to other nonphysician providers, as well as pre-existing referral pathways to PTs.

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