The acute response of tendon to loading: implications for rehabilitation

Achilles tendinopathy is a common disorder involving physically active and sedentary individuals alike. Although the processes underlying its development are poorly understood, tendinopathy is widely regarded as an ‘overuse’ injury in which the tendon fails to adapt to prevalent loading conditions. Paradoxically, there is emerging evidence that heavy eccentric loading of the Achilles tendon may be an effective conservative approach for treatment of tendinopathy, with success rates of 60–80% reported. Interestingly, loading exercises involving other forms of muscle action, such as concentric activation, have been shown to be less effective treatment options. However, little is known about the acute response of tendon to exercise at present, and there are few plausible explanatory mechanisms for the observed beneficial effects of eccentric exercise, as opposed to other forms of strain stimuli. This paper presents the findings from a series of experiments undertaken to evaluate the effect of various strain stimuli on the time-dependent response of human Achilles tendon in vivo. It was shown for the first time, that heavy resistive ankle plantarflexion/ dorsiflexion exercises induced an immediate and significant decrease in Achilles tendon thickness (~15%). While thickness returned to pre-exercise levels within 24 hours, the recovery was exponential, with primary recovery occurring in less than 6 hours post-exercise. We proposed that such a diametral strain response with tensile loading reflects collagen realignment, Poison’s effects and radial extrusion of water from the tendon core. With unloading, the recovery of tendon dimensions likely reflects the re-diffusion of water via osmotic and/or inflammatory driven processes. Interestingly, prolonged walking was found to induce a similar diametral strain response. In subsequent studies, we demonstrated that eccentric exercise resulted in a greater reduction (-21%) in Achilles tendon thickness than isolated concentric exercise alone (-5%), despite a similar loading impulse. These novel findings, coupled with observations of a reduced diametral strain response with tendon pathology, highlight the importance of fluid movement to tendon function, nutrition and health. They also provide new insights into potential mechanisms underlying Achilles tendinopathy that impact rehabilitation strategies

Collaborative decision making improves interpersonal psychotherapy efficiency: A randomized clinical trial with postpartum women

Background: Randomized controlled trials of Interpersonal Psychotherapy (IPT) and other psychotherapies for depression have required strict adherence to protocol and do not allow for clinical judgment in deciding frequency of sessions. To determine if such protocols were more effective than allowing therapists to use their clinical judgment, we compared “Clinician- Managed” IPT (CM-IPT), in which clinicians and patients with postpartum depression were allotted 12 sessions and determined collaboratively when to use them, to a once weekly 12 session protocol (“Standard IPT”). We hypothesized that CM-IPT would be more efficient, requiring fewer sessions to reach an equivalent acute outcome, and that CM-IPT would be superior over 12 months because “saved” sessions could be used for maintenance treatment. Method: We conducted a clinical trial including 140 postpartum outpatients with DSM-IV major depression who were randomly assigned to “Standard” IPT (N= 69) or CM-IPT (N= 71). Results: Both CM-IPT and S-IPT were highly efficacious with similar outcomes by 12 weeks but CM-IPT group utilized significantly fewer sessions. Both were superior to a waitlist control. Superiority comparisons at 12 months did not favor the CM-IPT condition. Limitations: Results should be replicated in a more diverse sample to increase generalizability. Conclusions: CM-IPT is more efficient in treating acute depression than mandated weekly IPT. Further, permitting clinicians and patients to use their collaborative judgment is likely to be a more efficient and effective way to conduct future research and to implement evidence-based psychotherapy in the community

A molecular genetic toolbox for Yarrowia lipolytica

Background: Yarrowia lipolytica is an ascomycete yeast used in biotechnological research for its abilities to secrete high concentrations of proteins and accumulate lipids. Genetic tools have been made in a variety of backgrounds with varying similarity to a comprehensively sequenced strain. Results: We have developed a set of genetic and molecular tools in order to expand capabilities of Y. lipolytica for both biological research and industrial bioengineering applications. In this work, we generated a set of isogenic auxotrophic strains with decreased non-homologous end joining for targeted DNA incorporation. Genome sequencing, assembly, and annotation of this genetic background uncovers previously unidentified genes in Y. lipolytica. To complement these strains, we constructed plasmids with Y. lipolytica-optimized superfolder GFP for targeted overexpression and fluorescent tagging. We used these tools to build the "Yarrowia lipolytica Cell Atlas," a collection of strains with endogenous fluorescently tagged organelles in the same genetic background, in order to define organelle morphology in live cells. Conclusions: These molecular and isogenetic tools are useful for live assessment of organelle-specific protein expression, and for localization of lipid biosynthetic enzymes or other proteins in Y. lipolytica. This work provides the Yarrowia community with tools for cell biology and metabolism research in Y. lipolytica for further development of biofuels and natural products

Concussion Symptoms and Return to Play Time in Youth, High School, and College American Football Athletes

IMPORTANCE: To our knowledge, little research has examined concussion across the youth/adolescent spectrum and even less has examined concussion-related outcomes (ie, symptoms and return to play). OBJECTIVE: To examine and compare sport-related concussion outcomes (symptoms and return to play) in youth, high school, and collegiate football athletes. DESIGN, SETTING, AND PARTICIPANTS: Athletic trainers attended each practice and game during the 2012 to 2014 seasons and reported injuries. For this descriptive, epidemiological study, data were collected from youth, high school, and collegiate football teams, and the analysis of the data was conducted between July 2015 and September 2015. The Youth Football Surveillance System included more than 3000 youth football athletes aged 5 to 14 years from 118 teams, providing 310 team seasons (ie, 1 team providing 1 season of data). The National Athletic Treatment, Injury, and Outcomes Network Program included 96 secondary school football programs, providing 184 team seasons. The National Collegiate Athletic Association Injury Surveillance Program included 34 college football programs, providing 71 team seasons. MAIN OUTCOMES AND MEASURES: We calculated the mean number of symptoms, prevalence of each symptom, and the proportion of patients with concussions that had long return-to-play time (ie, required participation restriction of at least 30 days). Generalized linear models were used to assess differences among competition levels in the mean number of reported symptoms. Logistic regression models estimated the odds of return to play at less than 24 hours and at least 30 days. RESULTS: Overall, 1429 sports-related concussions were reported among youth, high school, and college-level football athletes with a mean (SD) of 5.48 (3.06) symptoms. Across all levels, 15.3% resulted return to play at least 30 days after the concussion and 3.1% resulted in return to play less than 24 hours after the concussion. Compared with youth, a higher number of concussion symptoms were reported in high school athletes (β = 1.39; 95% CI, 0.55-2.24). Compared with college athletes, the odds of return to play at least 30 days after injury were larger in youth athletes (odds ratio, 2.75; 95% CI, 1.10- 6.85) and high school athletes (odds ratio, 2.89; 95% CI, 1.61-5.19). The odds of return to play less than 24 hours after injury were larger in youth athletes than high school athletes (odds ratio, 6.23; 95% CI, 1.02-37.98). CONCLUSIONS AND RELEVANCE: Differences in concussion-related outcomes existed by level of competition and may be attributable to genetic, biologic, and/or developmental differences or level-specific variations in concussion-related policies and protocols, athlete training management, and athlete disclosure. Given the many organizational, social environmental, and policy-related differences at each level of competition that were not measured in this study, further study is warranted to validate our findings

Modelling Immunological Systems using PEPA: a preliminary report

We present preliminary work on modelling aspects of the immune system using process algebra. The problem addressed is how T-helper cell populations respond to co-infections with parasites making conflicting immunological demands. Our goal is to build PEPA models of alternative hypotheses around T-helper cell behaviour and to evaluate those with respect to experimental data

A long-term decline in the abundance of endangered leatherback turtles, \u3cem\u3eDermochelys coriacea\u3c/em\u3e, at a foraging ground in the California Current Ecosystem

Pacific leatherback turtles (Dermochelys coriacea) are critically endangered, and declines have been documented at multiple nesting sites throughout the Pacific. The western Pacific leatherback forages in temperate and tropical waters of the Indo-Pacific region, and about 38–57% of summer-nesting females from the largest remaining nesting population in Papua Barat (Indonesia) migrate to distant foraging grounds off the U.S. West Coast, including neritic waters off central California. In this study, we examined the trend in leatherback abundance off central California from 28 years of aerial survey data from coast-wide and adaptive fine-scale surveys. We used a Bayesian hierarchical analysis framework, including a process model of leatherback population density and an observation model relating leatherback observations to distance sampling methods. We also used time-depth data from biologgers deployed on 21 foraging leatherback turtles in the study area to account for detection biases associated with diving animals. Our results indicate that leatherback abundance has declined at an annual rate of −5.6% (95% credible interval −9.8% to −1.5%), without any marked changes in ocean conditions or prey availability. These results are similar to the nesting population trends of −5.9% and −6.1% per year estimated at Indonesian index beaches, which comprise 75% of western Pacific nesting activity. Combined, the declining trends underscore the need for coordinated international conservation efforts and long-term population monitoring to avoid extirpation of western Pacific leatherback turtles