Chronic Delivery of a Thrombospondin-1 Mimetic Decreases Skeletal Muscle Capillarity in Mice

Angiogenesis is an essential process for normal skeletal muscle function. There is a growing body of evidence suggesting that thrombospondin-1 (TSP-1), a potent antiangiogenic protein in tumorigenesis, is an important regulator of both physiological and pathological skeletal muscle angiogenesis. We tested the hypothesis that chronic exposure to a TSP-1 mimetic (ABT-510), which targets the CD36 TSP-1 receptor, would decrease skeletal muscle capillarity as well as alter the balance between positive and negative angiogenic proteins under basal conditions. Osmotic minipumps with either ABT-510 or vehicle (5% dextrose) were implanted subcutaneously in the subscapular region of C57/BL6 mice for 14 days. When compared to the vehicle treated mice, the ABT-510 group had a 20% decrease in capillarity in the superficial region of the gastrocnemius (GA), 11% decrease in the plantaris (PLT), and a 35% decrease in the soleus (SOL). ABT-510 also decreased muscle protein expression of vascular endothelial growth factor (VEGF) in both the GA (−140%) and SOL (−62%); however there was no change in VEGF in the PLT. Serum VEGF was not altered in ABT-510 treated animals. Endogenous TSP-1 protein expression in all muscles remained unaltered. Tunnel staining revealed no difference in muscle apoptosis between ABT-510 and vehicle treated groups. These data provide evidence that the anti-angiogenic effects of TSP-1 are mediated, at least in part, via the CD36 receptor. It also suggests that under physiologic conditions the TSP-1/CD36 axis plays a role in regulating basal skeletal muscle microvessel density

Set-shifting and place-keeping as separable control processes

We present three experiments using a sequential binary choice task that explore the relationship between two proposed cognitive control functions: set-shifting and place-keeping (i.e., keeping track of one’s place within a sequential task). The task involves switching from one stimulus-response mapping to another across trials, according to a predefined sequence and in the face of occasional brief interruptions. Response-stimulus interval, interruption length and interrupting task were varied. The robust finding across all experiments was that varying response-stimulus interval led to standard effects attributable to set-shifting, while varying interruption length led to standard effects attributable to place-keeping, but in no cases did the factors interact. We interpret the results as supporting the view that set-shifting and place-keeping are achieved by separable control processes and illustrate this interpretation with a computational model of performance on the task

The Academics Athletics Trade-off: Universities and Intercollegiate Athletics

This analysis focuses on several key issues in the Football Bowl Subdivision (FBS). The intrinsic benefits of athletic programs are discussed in the first section. Trends in graduation rates and academic performance among athletes and how they correlate with the general student body are discussed in the second section. Finally, an overview of the revenues and expenses of athletic department budgets are discussed in an effort to gain a better understanding of the allocation of funds to athletics. In spite of recent growth in revenues and expenses, the athletic department budget comprises on average only 5 percent of the entire university budget at an FBS school, though spending and revenues have increased dramatically in recent years. In the grand scheme of things, American higher education faces several other, arguably more pressing, areas of reform. However, athletics is a significant and growing dimension of higher education that warrants in-depth examination

Muscle protein metabolism in neonatal alloxan-administered rats: effects of continuous and intermittent swimming training

<p>Abstract</p> <p>Background</p> <p>This study aimed to examine the effects of intermittent and continuous swimming training on muscle protein metabolism in neonatal alloxan-administered rats.</p> <p>Methods</p> <p>Wistar rats were used and divided into six groups: sedentary alloxan (SA), sedentary control (SC), continuous trained alloxan (CA), intermittent trained alloxan (IA), continuous trained control (CC) and intermittent trained control (IC). Alloxan (250 mg/kg body weight) was injected into newborn rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 5% of body weight; uninterrupted swimming for 1 h/day, five days a week. The intermittent training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 15% of body weight; 30 s of activity interrupted by 30 s of rest for a total of 20 min/day, five days a week.</p> <p>Results</p> <p>At 28 days, the alloxan animals displayed higher glycemia after glucose overload than the control animals. No differences in insulinemia among the groups were detected. At 120 days, no differences in serum albumin and total protein among the groups were observed. Compared to the other groups, DNA concentrations were higher in the alloxan animals that were subjected to continuous training, whereas the DNA/protein ratio was higher in the alloxan animals that were subjected to intermittent training.</p> <p>Conclusion</p> <p>It was concluded that continuous and intermittent training sessions were effective in altering muscle growth by hyperplasia and hypertrophy, respectively, in alloxan-administered animals.</p

Tai Chi on psychological well-being: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Physical activity and exercise appear to improve psychological health. However, the quantitative effects of Tai Chi on psychological well-being have rarely been examined. We systematically reviewed the effects of Tai Chi on stress, anxiety, depression and mood disturbance in eastern and western populations.</p> <p>Methods</p> <p>Eight English and 3 Chinese databases were searched through March 2009. Randomized controlled trials, non-randomized controlled studies and observational studies reporting at least 1 psychological health outcome were examined. Data were extracted and verified by 2 reviewers. The randomized trials in each subcategory of health outcomes were meta-analyzed using a random-effects model. The quality of each study was assessed.</p> <p>Results</p> <p>Forty studies totaling 3817 subjects were identified. Approximately 29 psychological measurements were assessed. Twenty-one of 33 randomized and nonrandomized trials reported that 1 hour to 1 year of regular Tai Chi significantly increased psychological well-being including reduction of stress (effect size [ES], 0.66; 95% confidence interval [CI], 0.23 to 1.09), anxiety (ES, 0.66; 95% CI, 0.29 to 1.03), and depression (ES, 0.56; 95% CI, 0.31 to 0.80), and enhanced mood (ES, 0.45; 95% CI, 0.20 to 0.69) in community-dwelling healthy participants and in patients with chronic conditions. Seven observational studies with relatively large sample sizes reinforced the beneficial association between Tai Chi practice and psychological health.</p> <p>Conclusions</p> <p>Tai Chi appears to be associated with improvements in psychological well-being including reduced stress, anxiety, depression and mood disturbance, and increased self-esteem. Definitive conclusions were limited due to variation in designs, comparisons, heterogeneous outcomes and inadequate controls. High-quality, well-controlled, longer randomized trials are needed to better inform clinical decisions.</p

Leucine and tissue distribution of bulky and small neutral amino acids in rats: Dissociation between transport and insulin-mediated effects

The mechanism of the observed decrease in the plasma concentration of several amino acids in the presence of high levels of Leu has remained unexplained. In the present study a decrease in the plasma concentration of Ile, Val, Phe, Tyr, Met, Ala, Pro and Gly was observed after the intraperitoneal injection of Leu to weanling rats. Decreases in net intracellular concentrations in muscle accompanied the decrease in plasma of all of these amino acids except Pro and Gly. An increase in the distribution ratio muscle/plasma was observed exclusively for Gly after administration of Leu or of a non-insulinogenic transport system L analogue. Diazoxide suppressed the Leu-induced decreases in plasma and muscle intracellular concentrations of Ile and Val as well as of Pro in plasma. An increase in the distribution ratio liver/plasma was observed for Pro and Gly in the absence but not in the presence of diazoxide. All the above changes were statistically significant. Hence insulin probably mediates Leu effects, promoting an increased utilization of Ile and Val in muscle and of Pro in liver. A more direct effect of Leu appears to be involved in the apparent increased utilization of Phe, Tyr and Ala in the same tissue. Gly depletion in plasma can be explained by its trapping by inhibitory action of Leu on the exodus of Gly through transport system L.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42495/1/10545_2005_Article_BF01800357.pd