Increased Adenine Nucleotide Degradation in Skeletal Muscle Atrophy

Adenine nucleotides (AdNs: ATP, ADP, AMP) are essential biological compounds that facilitate many necessary cellular processes by providing chemical energy, mediating intracellular signaling, and regulating protein metabolism and solubilization. A dramatic reduction in total AdNs is observed in atrophic skeletal muscle across numerous disease states and conditions, such as cancer, diabetes, chronic kidney disease, heart failure, COPD, sepsis, muscular dystrophy, denervation, disuse, and sarcopenia. The reduced AdNs in atrophic skeletal muscle are accompanied by increased expression/activities of AdN degrading enzymes and the accumulation of degradation products (IMP, hypoxanthine, xanthine, uric acid), suggesting that the lower AdN content is largely the result of increased nucleotide degradation. Furthermore, this characteristic decrease of AdNs suggests that increased nucleotide degradation contributes to the general pathophysiology of skeletal muscle atrophy. In view of the numerous energetic, and non-energetic, roles of AdNs in skeletal muscle, investigations into the physiological consequences of AdN degradation may provide valuable insight into the mechanisms of muscle atrophy

Effect of Racing Flats on Running Economy in Male Adolescent Runners

The purpose of this study was to investigate whether running economy differs in racing flats versus standard running shoes in high school cross-country runners. In order to measure running economy the oxygen cost of running (mL O2∙kg-1∙min-1) was measured in 20 male adolescent runners (mean age = 16.25 ± 0.97 years, 5 km best time = 17.52 ± 0.78 min) when running two separate trials at a controlled speed. The speed was determined by estimating treadmill running speed at 85% of each runner\u27s VO2max. Each trial required the participants to run while wearing the Mizuno Wave Elixir 6TM standard running shoe and the Mizuno Wave Universe 4TM racing flat. The results indicated that after running both trials at the same speed, the high school runners demonstrated a significant 2% reduction (P \u3c .001) in the oxygen cost of running when comparing the racing flat (60.94 ± 5.83 mL∙kg-1∙min-1) to the standard running shoe (62.14 ± 5.87 mL∙kg-1∙min-1). The results of the current study suggest that the use of the Mizuno Wave Universe 4TM racing flat significantly improved running economy, most likely due to differences in shoe mass between the racing flat and standard running shoe

Physically Interactive Games Increase VO2 Above Resting Metabolic Rate

The purpose of this study was to determine the energy cost, beyond resting metabolic rate (RMR), of playing select games on the Nintendo Wii for 30 contiguous minutes. Physically interactive games (i.e. Basic Run and Basic Step) increase energy expenditure above resting values compared to a sedentary game (Tanks!) and therefore may help individual’s become more active. Furthermore, Basic Run and Basic Step elicited MET values of 3.9 and 3.2, respectively, which is considered moderate-intensity exercise and could be used to meet daily recommendations for physical activity

Interactive Video Gaming: Do We Feel Like We Are Exercising?

The primary purpose of this study was to determine if the rating of perceived exertion (RPE) and hedonics (liking or enjoyment) changed during 30 contiguous minutes of playing select, interactive video games on the Nintendo Wii system. A secondary purpose was to determine if RPE and liking differed among games.These data suggest that individuals do perceive difference in the amount of work they are performing during extended play of the same game or among sedentary and physically interactive games. Additionally, liking was similar during extended game play and among games suggesting that the physical interaction with the game may be superseded by interest in the game. Promoting the use of physically interactive gaming may be useful in helping individuals meet their daily recommendations for physical activity owing to their enjoyment which minimizes the perception of being physically demanding

Interactive Video Gaming Maintains VO2 & HR at Current Recommended Exercise Intensities for Cardiovascular Fitness

The purpose of this study was to determine the energy cost of playing select games on the Nintendo Wii for 30 contiguous minutes and whether or not the physical interaction of the participant with the gaming system and subsequent physiologic intensity diminishes with playing time

The association between frailty and MRI features of cerebral small vessel disease

Abstract: Frailty is a common syndrome in older individuals that is associated with poor cognitive outcome. The underlying brain correlates of frailty are unclear. The aim of this study was to investigate the association between frailty and MRI features of cerebral small vessel disease in a group of non-demented older individuals. We included 170 participants who were classified as frail (n = 30), pre-frail (n = 85) or non-frail (n = 55). The association of frailty and white matter hyperintensity volume and shape features, lacunar infarcts and cerebral perfusion was investigated by regression analyses adjusted for age and sex. Frail and pre-frail participants were older, more often female and showed higher white matter hyperintensity volume (0.69 [95%-CI 0.08 to 1.31], p = 0.03 respectively 0.43 [95%-CI: 0.04 to 0.82], p = 0.03) compared to non-frail participants. Frail participants showed a non-significant trend, and pre-frail participants showed a more complex shape of white matter hyperintensities (concavity index: 0.04 [95%-CI: 0.03 to 0.08], p = 0.03; fractal dimensions: 0.07 [95%-CI: 0.00 to 0.15], p = 0.05) compared to non-frail participants. No between group differences were found in gray matter perfusion or in the presence of lacunar infarcts. In conclusion, increased white matter hyperintensity volume and a more complex white matter hyperintensity shape may be structural brain correlates of the frailty phenotype

Towards Rawlsian ‘property-owning democracy’ through personal data platform cooperatives

This paper supports the personal data platform cooperative as a means of bringing about John Rawls’s favoured institutional realisation of a just society, the property-owning democracy. It describes personal data platform cooperatives and applies Rawls’s political philosophy to analyse the institutional forms of a just society in relation to the economic power deriving from aggregating personal data. It argues that a society involving a significant number of personal data platform cooperatives will be more suitable to realising Rawls’s principle of fair equality of opportunity

Sex-Related Differences in the Maximal Lactate Steady State

The maximal lactate steady state (MLSS) is one of the factors that differentiates performance in aerobic events. The purpose of this study was to investigate the sex differences in oxygen consumption (VO2), heart rate (HR), and the respiratory exchange ratio (RER) at the MLSS in well-trained distance runners. Twenty-two (12 female, 10 male) well-trained distance runners (23 ± 5.0 years) performed multiple 30-min steady-state runs to determine their MLSS, during which blood lactate and respiratory gas exchange measures were taken. To interpret the MLSS intensity as a training tool, runners completed a time-to-exhaustion (TTE) run at their MLSS. The relative intensity at which the MLSS occurred was identical between males and females according to both oxygen consumption (83 ± 5 %O2max) and heart rate (89 ± 7 %HRmax). However, female runners displayed a significantly lower RER at MLSS compared to male runners (p < 0.0001; 0.84 ± 0.02 vs. 0.88 ± 0.04, respectively). There was not a significant difference in TTE at MLSS between males (79 ± 17 min) and females (80 ± 25 min). Due to the observed difference in the RER at the MLSS, it is suggested that RER derived estimates of MLSS be sex-specific. While the RER data suggest that the MLSS represents different metabolic intensities for males and females, the relative training load of MLSS appears to be similar in males and female runners

Liquid Chromatography Method for Simultaneous Quantification of ATP and its Degradation Products Compatible with both UV-Vis and Mass Spectrometry

ATP and its degradation products are essential metabolic and signaling molecules. Traditionally, they have been quantified via high-performance liquid chromatography (HPLC) with UV-Vis detection while utilizing phosphate buffer mobile phase, but this approach is incompatible with modern mass detection. The goal of this study was to develop an ultra-performance liquid chromatography (UPLC) method free of phosphate buffer, to allow for analysis of adenine nucleotides with UV-Vis and mass spectrometry (MS) simultaneously. The final conditions used an Acquity HSS T3 premier column with a volatile ammonium acetate buffer to successfully separate and quantify ATP-related analytes in a standard mixture and in extracts from non-contracted and contracted mouse hindlimb muscles. Baseline resolution was achieved with all 10 metabolites, and a lower limit of quantification down to 1 pmol per inject was observed for most metabolites using UV-Vis. Therefore, this method allows for the reliable quantification of adenine nucleotides and their degradation products via UV-Vis and their confirmation and/or identification of unknown peaks via MS