163 research outputs found

    Ingestion of 10 Grams of Whey Protein Prior To a Single Bout of Resistance Exercise Does Not Augment Akt/Mtor Pathway Signaling Compared To Carbohydrate

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    Background: This study examined the effects of a whey protein supplement in conjunction with an acute bout of lower body resistance exercise, in recreationally-active males, on serum insulin and insulin like growth factor 1 (IGF-1) and Akt/mTOR signaling markers indicative of muscle protein synthesis: insulin receptor substrate 1 (IRS-1), AKT, mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K) and 4E-binding protein 1 (4E-BP1). Methods: In a randomized, double-blind, cross-over design, 10 males ingested 1 week apart, either 10 g of whey protein (5.25 g EAAs) or carbohydrate (maltodextrose), 30 min prior to a lower-body resistance exercise bout. The resistance exercise bout consisted of 4 sets of 8-10 reps at 80% of the one repetition maximum (RM) on the angled leg press and knee extension exercises. Blood and muscle samples were obtained prior to, and 30 min following supplement ingestion and 15 min and 120 min post-exercise. Serum and muscle data were analyzed using two-way ANOVA. Results: No significant differences were observed for IGF-1 (p \u3e 0.05). A significant main effect for Test was observed for serum insulin (p \u3c 0.01) at 30 min post-ingestion and 15 and 120 min post-exercise, with no Supplement x Test interaction (p \u3e 0.05). For the Akt/MTOR signaling intermediates, no significant Supplement x Test interactions were observed (p \u3e 0.05). However, significant main effects for Test were observed for phosphorylated concentrations of IRS, mTOR, and p70S6K, as all were elevated at 15 min post-exercise (p \u3c 0.05). Additionally, a significant main effect for Test was noted for 4E-BP1 (p \u3c 0.05), as it was decreased at 15 min post-exercise. Conclusion: Ingestion of 10 g of whey protein prior to an acute bout of lower body resistance exercise had no significant preferential effect compared to carbohydrate on systemic and cellular signaling markers indicative of muscle protein synthesis in untrained individuals

    Stoichiometric and Stable Isotope Ratios of Wild Lizards in an Urban Landscape Vary with Reproduction, Physiology, Space and Time

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    Spatial and temporal variation in stoichiometric and stable isotope ratios of animals contains ecological information that we are just beginning to understand. In both field and lab studies, stoichiometric or isotopic ratios are related to physiological mechanisms underlying nutrition or stress. Conservation and ecosystem ecology may be informed by isotopic data that can be rapidly and non-lethally collected from wild animals, especially where human activity leaves an isotopic signature (e.g. via introduction of chemical fertilizers, ornamental or other non-native plants or organic detritus). We examined spatial and temporal variation in stoichiometric and stable isotope ratios of the toes of Uta stansburiana (side-blotched lizards) living in urban and rural areas in and around St. George, Utah. We found substantial spatial and temporal variation as well as context-dependent co-variation with reproductive physiological parameters, although certain key predictions such as the relationship between δ15N and body condition were not supported. We suggest that landscape change through urbanization can have profound effects on wild animal physiology and that stoichiometric and stable isotope ratios can provide unique insights into the mechanisms underlying these processes

    Obesity and Overweight Prevalence among a Mississippi Low-Income Preschool Population: A Five-Year Comparison

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    Purpose. This study determined 2010 rates of overweight/obesity in a representative sample of low-income preschoolers in Mississippi, USA and compared rates between 2005 (N = 1250) and 2010 (N = 1765). Significance. Obesity is a significant global health issue because of its well-established negative health consequences. Child obesity is a concern due to risk of early-onset obesity-related illnesses and the longevity of lifetime exposure to those illnesses. Methods. Identical measures were used in 2005 and 2010 with complex-stratified sampling designs. Results. Chi-square tests revealed that overall obesity/overweight rates between 2005 (20.6%/17.9%) and 2010 (20.8%/17.0%) had not changed significantly for the samples as a whole, nor by gender or race. Age group comparisons indicated a significant decline in obesity rates of 3 year olds (20.3% in 2005, reduced to 13.1% in 2010, P = 0.035). These findings mimic the trend toward stabilization of obesity rates noted in national low-income preschool populations

    Effect of Six Weeks of Oral \u3ci\u3eEchinacea purpurea\u3c/i\u3e Supplementation On Nitric Oxide Production

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    Echinacea purpurea, a purple coneflower plant of the compositae family (Asteraceae), is native to North America and commonly used as an herbal supplement to enhance immune function. Echinacea purpurea has been shown to stimulate macrophage activity which is a known stimulator of nitric oxide (NO) production. Echinacea purpurea supplementation (8,000 mg·d-1) in untrained (42.5 ± 1.6 mL·kg-1·min-1) males was shown to elicit a 63% increase (p \u3c 0.05) in serum erythropoietin (EPO) following two weeks of supplementation. This is supported in part by earlier findings which indicated that four weeks of Echinacea purpurea supplementation demonstrated a non-significant increase in maximal oxygen uptake (VO2max). It is plausible that Echinacea-induced EPO production may stimulate physiological responses independent of and/or in addition to erythropoiesis. There is also evidence suggesting EPO has vasculo-protective effects including the activation of endothelial nitric oxide synthase (eNOS). Based on these findings, a proposed non-hematological response to the Echinacea-induced increase in EPO could be enhanced NO production. The purpose of this investigation was to determine whether six weeks of oral Echinacea purpurea supplementation augmented NO production as a result of an Echinacea-induced increase in EPO and/or Echinacea-induced macrophage activity

    Bioactive Properties and Clinical Safety of a Novel Milk Protein Peptide

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    Background: Milk protein fractions and peptides have been shown to have bioactive properties. This preliminary study examined the potential mechanisms of action and clinical safety of novel milk protein peptide ( MP). Findings: A novel MP mixture inhibits the tyrosine kinase activity of epidermal growth factor receptor ( EGFR), vascular endothelial growth factor receptor 2 (VEGFR2), and insulin receptor (IR) with IC(50) of 9.85 mu M, 7.7 mu M, and 6.18 mu M respectively. In vitro, this multi-kinase inhibitor causes apoptosis in HT-29 colon cancer cells, and in a C. elegans worm study, showed a weak but significant increase in lifespan. A six week double-blind, placebo-controlled study involving 73 healthy volunteers demonstrated that the MP mixture is safe to consume orally. All clinical blood markers remained within normal levels and no clinically significant side effects were reported. There was some evidence of improved insulin sensitivity, neutrophil-to-lymphocyte ratio (NLR), and quality of life assessment of role of physical function. Conclusions: These data in combination with the observed in vitro anti-cancer properties warrant further clinical studies to investigate this MP mixture as a potential clinical nutrition intervention for improving the quality of life and clinical outcomes in cancer patients

    Patterns of Upper Gastrointestinal Diseases Based on Endoscopy in the Period 1998-2001

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    Upper gastrointestinal complaints are common in Kenya. Though these have remained unchanged over the last 20 years, the pattern of upper gastrointestinal disease on endoscopic examination seems to be changing. There appears to be progressive increase in oesophagitis and cancer of the stomach. Peptic ulcer disease has remained stable while Cancer of the oesophagus is still common. The paper intends to report on endoscopic findings at the Centre for Clinical Research, Kenya Medical Research Institute (KEMRI) over the period October 1998 and May 2001. The sources of information are records made at the time of endoscopy and histology reports on biopsies taken. Seven hundred and sixty eight patients were endoscoped. The male to female ratio was 1.7:1 with mean age \ub1SD of 40.8 \ub120.1 years and age range was 3 to 96 years. Majority of the patients had abnormal findings with gastritis being the most common ( 25.8%). It is concluded that gastritis is an important cause of morbidity in Kenya. Oesophagitis, mainly due to gastroesopahageal reflux disease, seems to be on the increase. Gastric cancer is not as rare as previously thought and peptic ulcer disease is still common
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