A preseason cardiorespiratory profile of dancers in nine professional ballet and modern companies.

While studies have investigated the physical demands of dance in terms of cardiorespiratory fitness, there are no recent comparisons of cardiorespiratory response to exercise among professional dancers of different genres. Our purpose was to: 1. develop a cardiorespiratory profile of professional dancers; 2. investigate differences in peak and recovery heart rate (HR) between professional modern and ballet dancers using an accelerated 3-minute step test; 3. demonstrate the relationship between cardiorespiratory variables; and 4. investigate the effects of company and work variables on the dancers' cardiorespiratory profiles. We hypothesized greater cardiorespiratory fitness in modern dancers than in ballet dancers, due to the nature of their repertory. Furthermore, we hypothesized that company profiles would reflect differences in work variables. Two hundred and eleven dancers (mean age 24.6 ± 4.7) from nine companies (two modern and seven ballet) performed a 3-minute step test. Demographics, height, mass, blood pressure (BP), smoking history, and resting peak and recovery HR were recorded. Body mass index (BMI) and fitness category were calculated. Independent t-tests were used to compare differences in demographics and cardiorespiratory variables due to genre, MANOVA were conducted to compare differences due to company, and correlations were calculated to determine the relationships between cardiorespiratory variables (p < 0.05). Modern dancers demonstrated higher mass and BMI, lower BP, lower resting HR and HR recovery, and a higher percentage were categorized as "fit" compared to ballet dancers (p < 0.03). There were differences between companies in age, experience, BMI, BP, resting, peak, and recovery HR, and fitness category (p < 0.001). The differences in cardiorespiratory fitness levels that may be related to rigor of repertory, rehearsal and performance seasons, or off-season exercise training are discussed. Results support the need for comprehensive physical fitness screening to identify dancers who could benefit from aerobic conditioning to enhance overall performance preparedness and to minimize fatigue effects.

In vitro and in vivo models for the study of oral delivery of nanoparticles.

Oral delivery is an attractive route to deliver therapeutics via nanoparticles due to its ease of administration and patient compliance. This review discusses laboratory techniques for studying oral delivery of nanoparticles, which offer protection of cargo through the gastrointestinal tract. Some of the difficulties in modeling oral delivery include the harsh acidic environment, variable pH, and the tight monolayer of endothelial cells present throughout the gastrointestinal tract. The use of in vitro techniques including the Transwell ® system, simulated gastric/intestinal fluid, and diffusion chambers addresses these challenges. When studying effects after oral delivery in vivo, bioimaging of nanoparticle biodistribution using radioactive markers has been popular. Functional assays such as immune response and systemic protein concentration analysis can further define the merits of the oral delivery systems. As biologics become increasingly more important in chronic therapies, nanoparticle-mediated oral delivery will assume greater prominence, and more sophisticated in vitro and in vivo models will be required.

Assessing and Reporting Dancer Capacities, Risk Factors, and Injuries: Recommendations from the IADMS Standard Measures Consensus Initiative.

This technical report of the Standard Measures Consensus Initiative of the International Association for Dance Medicine and Science (IADMS) describes the results of the committee's multi-year effort to synthesize information regarding the tests and measures used in dance-related research, protocols for reporting injuries, and appropriate use of available technologies to aid in standardizing such matters. Specific recommendations are presented, with accompanying rationales, to facilitate consensus among members of the dance medicine and science community. An Executive Summary of this Technical Report, which contains implementation strategies and appendices, should soon be available on the IADMS website.

Lytic peptide-mediated sensitization of TRAIL-resistant prostate cancer cells to death receptor agonists.

Tumor Necrosis Factor-alpha Related Apoptosis Inducing Ligand (TRAIL) and agonistic antibodies to death receptors (DR) 4 and 5 have attracted significant attention in recent years due to their ability to selectively induce apoptosis in malignant cells while demonstrating little cytotoxicity in normal cells. Although these candidates are promising in cancer therapy, a number of tumor cells are resistant to TRAIL-mediated apoptosis. We describe the use of a cationic amphipathic lytic peptide, KLA (single letter sequence HHHHHKLAKLAKKLAKLAKC), for the chemosensitization of TRAIL-resistant LNCaP and PC3-PSMA human prostate cancer cells to DR agonistic antibodies. 'Single-agent' treatment with DR agonistic antibodies did not result in loss of viability of these cells confirming the resistance of these cells. However, the combination treatment of KLA followed by DR agonists resulted in greater cell death compared to the individual treatments acting alone, indicating synergistic action between the two components of the combination treatment. The combination of lytic peptide and DR agonists resulted in a significant increase in activated caspase-3 cleavage and cytochrome-C protein levels in cells, indicating a role for the caspase-mediated apoptotic pathway. In addition, KLA treatment also resulted in increased localization of DR5 and lipid rafts in LNCaP cells. Our results demonstrate, for the first time, that lytic peptides can be employed for sensitizing TRAIL-resistant prostate cancer cells to DR-mediated apoptosis resulting in novel combination treatments for the ablation of advanced cancer cells.

Injury patterns in elite preprofessional ballet dancers and the utility of screening programs to identify risk characteristics.

STUDY DESIGN: Retrospective descriptive cohort study. OBJECTIVES: To describe the distribution and rate of injuries in elite adolescent ballet dancers, and to examine the utility of screening data to distinguish between injured and noninjured dancers. BACKGROUND: Adolescent dancers account for most ballet injuries. Limited information exists, however, regarding the distribution of, rate of, and risk factors for, adolescent dance injuries. METHODS AND MEASURES: Two hundred four dancers (age, 9-20 years) were screened over 5 years. Screening data were collected at the beginning and injury data were collected at the end of each training year. Descriptive statistics were used to characterize distribution and rate of injuries. Inference statistics were used to examine differences between injured and noninjured dancers. RESULTS: Fifty-three percent of injuries occurred in the foot/ankle, 21.6% in the hip, 16.1% in the knee, and 9.4% in the back. Thirty-two to fifty-one percent of the dancers were injured each year, and, over the 5 years, there were 1.09 injuries per 1000 athletic exposures, and 0.77 injuries per 1000 hours of dance. Significant differences between injured and noninjured dancers were limited to current disability scores (P = .007), history of low back pain (P = .017), right foot pronation (P = .005), insufficient right-ankle plantar flexion (P = .037), and lower extremity strength (P = .045). CONCLUSION: Distribution of injuries was similar to that of other studies. Injury rates were lower than most reported rates, except when expressed per 1000 hours of dance. Few differences were found between injured and noninjured dancers. These findings should be considered when designing and implementing screening programs.