122 research outputs found

    The Effects of Anchor Schemes on Performance Fatigability, Neuromuscular Responses and the Perceived Sensations That Contributed to Task Termination

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    The present study examined the effect of anchor schemes on the time to task failure (TTF), performance fatigability, neuromuscular responses, and the perceived sensations that contributed to task termination following the sustained, isometric forearm flexion tasks. Eight women completed sustained, isometric forearm flexion tasks anchored to RPE = 8 (RPEFT) and the torque (TRQFT) that corresponded to RPE = 8. The subjects performed pre-test and post-test maximal isometric contractions to quantify performance fatigability and changes in electromyographic amplitude (EMG AMP) and neuromuscular efficiency (NME). In addition, the subjects completed a post-test questionnaire (PTQ) to quantify the contributions of perceived sensations to task termination. Repeated measure ANOVAs were used to assess the mean differences for TTF, performance fatigability, and neuromuscular responses. Wilcoxon Signed Rank Tests were used to assess the differences between anchor schemes for the average values from the PTQ item scores. For TTF, the RPEFT was longer than the TRQFT (174.9 ± 85.6 vs. 65.6 ± 68.0 s; p = 0.006). Collapsed across the anchor scheme, there were decreases in torque (23.7 ± 5.5 Nm vs. 19.6 ± 4.9 Nm; p \u3c 0.001) and NME (1.00 ± 0.00 vs. 0.76 ± 0.15; p = 0.003). There were no significant (p \u3e 0.577) changes for EMG AMP. For the PTQ, there were no differences (p \u3e 0.05) between anchor schemes. There were, however, inter-individual differences in the response scores. The current findings indicated that performance fatigability was likely due to peripheral fatigue (based on NME), not central fatigue (based on EMG AMP). Furthermore, the use of a PTQ may serve as a simple tool to assess the contributions of perceived sensations to task termination

    Performance Fatigability and Neuromuscular Responses Are Not Joint Angle Specific Following a Sustained Isometric Forearm Flexion Task Anchored to a High Perceptual Intensity in Women

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    Objectives: To examine the effects of joint angle (JA) on maximal voluntary isometric contractions (MVIC) and neuromuscular responses following a sustained, isometric forearm flexion task anchored to a rating of perceived exertion (RPE) of 8 (RPE=8). Methods: Nine women (age: 20.7±2.9 yrs; height: 168.8±7.2 cm; body mass: 66.3±6.8 kg) performed 2,3s forearm flexion MVICs at JAs of 75°, 100°, and 125° prior to and following a sustained, isometric forearm flexion task anchored to RPE=8 to task failure (torque reduced to zero) at JA100. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from the biceps brachii. Results: The MVIC at JA100 (collapsed across Time) was significantly greater (pppp\u3e0.05) differences between Time or JAs. Pre-test neuromuscular efficiency (normalized MVIC/normalized EMG AMP) was significantly greater (p=0.005) than post-test. Conclusion: Following a sustained, isometric forearm flexion task anchored to RPE=8 at JA100, the fatigue-induced MVIC and neuromuscular responses were not affected by JA

    Fatiguing Joint Angle Does Not Influence Torque and Neuromuscular Responses Following Sustained, Isometric Forearm Flexion Tasks Anchored to Perceptual Intensity in Men

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    This study examined the effects of joint angle (JA) on maximal voluntary isometric contraction (MVIC) and neuromuscular responses following fatiguing tasks anchored to RPE. Nine men (mean ± SD: age = 20.7 ± 1.2 yrs) performed forearm flexion MVICs at elbow JAs of 75o and 125o before and after sustained, isometric forearm flexion tasks to failure at fatiguing joint angles (FJA) of 75o and 125o anchored to RPE = 8. The amplitude and frequency of the electromyographic and mechanomyographic signals were recorded. Neuromuscular efficiency was calculated by dividing normalized torque by normalized electromyographic amplitude. A dependent t-test was used to assess the mean difference for time to task failure (TTF) between FJA. Repeated measure ANOVAs were used to assess mean differences for pre-test to post-test MVIC and neuromuscular responses. There was no significant difference between FJA for TTF (p = 0.223). The MVIC (collapsed across FJA and MVIC JA) decreased from pre-test to post-test (51.1 ± 5.0 vs. 45.3 ± 5.6 Nm, p \u3c 0.001). Normalized neuromuscular parameters remained unchanged (p \u3e 0.05). The FJA resulted in similar torque and neuromuscular responses, and the decreases in MVIC were not tracked by changes in the neuromuscular parameters. Thus, the neuromuscular parameters were not sensitive to fatigue, and pre-test to post-test measures may be compared between different FJA

    Fatiguing Joint Angle Does Not Influence Torque and Neuromuscular Responses Following Sustained, Isometric Forearm Flexion Tasks Anchored to Perceptual Intensity in Men

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    This study examined the effects of joint angle (JA) on maximal voluntary isometric contraction (MVIC) and neuromuscular responses following fatiguing tasks anchored to RPE. Nine men (mean ± SD: age = 20.7 ± 1.2 yrs) performed forearm flexion MVICs at elbow JAs of 75o and 125o before and after sustained, isometric forearm flexion tasks to failure at fatiguing joint angles (FJA) of 75o and 125o anchored to RPE = 8. The amplitude and frequency of the electromyographic and mechanomyographic signals were recorded. Neuromuscular efficiency was calculated by dividing normalized torque by normalized electromyographic amplitude. A dependent t-test was used to assess the mean difference for time to task failure (TTF) between FJA. Repeated measure ANOVAs were used to assess mean differences for pre-test to post-test MVIC and neuromuscular responses. There was no significant difference between FJA for TTF (p = 0.223). The MVIC (collapsed across FJA and MVIC JA) decreased from pre-test to post-test (51.1 ± 5.0 vs. 45.3 ± 5.6 Nm, p \u3c 0.001). Normalized neuromuscular parameters remained unchanged (p \u3e 0.05). The FJA resulted in similar torque and neuromuscular responses, and the decreases in MVIC were not tracked by changes in the neuromuscular parameters. Thus, the neuromuscular parameters were not sensitive to fatigue, and pre-test to post-test measures may be compared between different FJA

    Dietary Intake, Nutritional Adequacy and Food Sources of Total Fat and Fatty Acids, and Relationships with Personal and Family Factors in Spanish Children Aged One to <10 Years: Results of the EsNuPI Study

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    We aimed to determine the usual intake of total fat, fatty acids (FAs), and their main food sources in a representative cohort of the Spanish pediatric population aged 1 to <10 years (n = 707) who consumed all types of milk and an age-matched cohort who consumed adapted milk over the last year (including follow-on formula, toddler’s milk, growing-up milk, and fortified and enriched milks) (n = 741) who were participants in the EsNuPI study (in English, Nutritional Study in the Spanish Pediatric Population). Dietary intake, measured through two 24 h dietary recalls, was compared to the European Food Safety Authority (EFSA) and the Food and Agriculture Organization of the United Nations (UN-FAO) recommendations. Both cohorts showed a high intake of saturated fatty acids (SFAs), according to FAO recommendations, as there are no numerical recommendations for SFAs at EFSA. Also, low intake of essential fatty acids (EFAs; linoleic acid (LA) and α-linolenic acid (ALA)) and long-chain polyunsaturated fatty acids (LC-PUFA) of the n-3 series, mainly docosahexaenoic acid (DHA) were observed according to EFSA and FAO recommendations. The three main sources of total fat and different FAs were milk and dairy products, oils and fats, and meat and meat products. The consumption of adapted milk was one of the main factors associated with better adherence to the nutritional recommendations of total fat, SFAs, EFAs, PUFAs; and resulted as the main factor associated with better adherence to n-3 fatty acids intake recommendations. Knowledge of the dietary intake and food sources of total fat and FAs in children could help in designing and promoting effective and practical age-targeted guidelines to promote the consumption of EFA- and n-3 PUFA-rich foods in this stage of life

    Usual dietary intake, nutritional adequacy and food sources of calcium, phosphorus, magnesium and vitamin D of spanish children aged one to dagger

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    Bone problems in the population begin to be establish in childhood. The present study aims to assess the usual calcium, phosphorus, magnesium, and vitamin D intakes, along with the food sources of these nutrients, in Spanish children participating in the EsNuPI (Estudio Nutricional en PoblaciĂłn Infantil Española) study. Two 24 h dietary recalls were applied to 1448 children (1 to <10 years) divided into two sub-samples: one reference sample (RS) of the general population [n = 707] and another sample which exclusively included children consuming enriched or fortified milks, here called “adapted milks” (AMS) [n = 741]. Estimation of the usual intake shows that nutrient intake increased with age for all nutrients except vitamin D. Using as reference the Dietary Reference Values from the European Food Safety Authority (EFSA), calcium and magnesium intakes were found to be below the average requirement (AR) and adequate intake (AI), respectively, in a considerable percentage of children. Furthermore, phosphorus exceeded the AI in 100% of individuals and vitamin D was lower than the AI in almost all children studied. The results were very similar when considering only plausible reporters. When analyzing the food sources of the nutrients studied, milk and dairy products contributed the most to calcium, phosphorus, magnesium, and vitamin D. Other sources of calcium were cereals and vegetables; for phosphorus: meat, meat products, and cereals; for magnesium: cereals and fruits; and, for vitamin D: fish and eggs. These results highlight the desirability of improving the intake concerning these nutrients, which are involved in bone and metabolic health in children. The AMS group appeared to contribute better to the adequacy of those nutrients than the RS group, but both still need further improvement. Of special interest are the results of vitamin D intakes, which were significantly higher in the AMS group (although still below the AI), independent of age

    Dietary and Lifestyle Patterns in the Spanish Pediatric Population (One to <10 Years Old): Design, Protocol, and Methodology of the EsNuPI Study

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    The interest in a healthy diet and lifestyle during the early stages of life increased, pointing out its role in the development of noncommunicable chronic diseases throughout adult life. Dietary habits and dietary patterns begin to be established in early childhood and persist during adulthood. Therefore, the EsNuPI ("Nutritional Study in Spanish Pediatric Population") study aims to depict the dietary patterns, physical activity, and sedentary behaviors in Spanish children aged from one to 50,000 inhabitants, stratified by Nielsen areas. Participants were involved in one face-to-face survey, followed by a telephone survey after at least one week. Information about dietary intake and habits was obtained using a quantitative food frequency questionnaire and two 24-h dietary recalls. Physical activity and sedentary behaviors were registered using a specific questionnaire based on a seven-day record. Data were processed and stratified by categorical variables to be statistically analyzed in order to meet the study objectives. This study is the first of its kind in a Spanish reference population of this age range and the first to evaluate whether the consumption of adapted milk formulas and dairy products is associated with healthier dietary patterns and better diet quality and lifestyles in this group

    Energy Intake, Macronutrient Profile and Food Sources of Spanish Children Aged One to <10 Years—Results from the EsNuPI Study

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    Abstract: The present study aimed to assess energy intake, nutrient profile and food sources in Spanish children participating in the EsNuPI (“Estudio Nutricional en PoblaciĂłn Infantil Española”) study. Plausibility of energy intake and adequacy of nutrient intakes to international recommendations were analyzed in a final sample of 1448 subjects (728 boys and 720 girls) and one group representative of the 1 to <10 years old urban Spanish children (reference sample (n = 707)) who consumed milk and one of the same age who consumed adapted milk over the last year (adapted milk consumers sample (n = 741)) were compared. Both groups completed data of a face-to-face and a telephone 24-h dietary recalls. Both the reference and the adapted milk consumers samples reported an adequate daily energy intake (1503 kcal/day and 1404 kcal/day); and a high contribution to total energy from protein (16.5% and 15.6%) and fat (36.5% and 35.9%). Also, a high percentage of children from both samples were below the lower limit of the recommendations for carbohydrates (47.8% and 39.3%). As the percentage of plausible energy reporters was high for both groups (84.7% and 83.5%, respectively), data for the whole sample were analyzed. Milk and dairy, cereals, meat and derived products, fats and oils, bakery and pastry, fruits and vegetables contributed to about 80% of the total energy intake in both groups. However, the reference sample reported significantly more contribution to energy from cereals, meat and meat products, bakery and pastry and ready to cook/eat foods; meanwhile, the adapted milk consumers sample reported significantly more energy from milk and dairy products, fruits and eggs. Those results suggest that adapted milk consumers have better adherence to the food-based dietary guidelines. Further analyses are warranted to characterize food patterns and the quality of the diet in the EsNuPI study population

    Urinary exosome miR-146a is a potential marker of albuminuria in essential hypertension

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    BACKGROUND: There is increasing interest in using extracellular vesicle-derived microRNAs (miRNAs) as biomarkers in renal dysfunction and injury. Preliminary evidence indicates that miRNAs regulate the progression of glomerular disease. Indeed, exosomes from the renal system have provided novel evidence in the clinical setting of albuminuria. Thus, the aim of this study was to quantify the urinary miRNAs present in exosome and microvesicles (MVs), and to assess their association with the presence of increased urinary albumin excretion in essential hypertension. METHODS: Exosomes were collected from urine specimens from a cohort of hypertensive patients with (n = 24) or without albuminuria (n = 28), and from 20 healthy volunteers as a control group. Urinary exosomes were phenotyped by Western blot, tunable resistive pulse sensing, and electronic microscopy. Expression of miR-146a and miR-335* was analysed by qRT-PCR and any associations between albuminuria and exosomal miRNAs were analysed. RESULTS: Urinary miRNAs are highly enriched in exosome subpopulations compared to MVs, both in patients with or without increased albuminuria (p < 0.001), but not in the control group. High albuminuria was associated with 2.5-fold less miR-146a in exosomes (p = 0.017), whereas miR-146a levels in MV did not change. In addition, exosome miR-146a levels were inversely associated with albuminuria (r = 0.65, p < 0.0001), and discriminated the presence of urinary albumin excretion presence [area under the curve = 0.80, 95% confidence interval: 0.66-0.95; p = 0.0013]. CONCLUSIONS: Our results indicate that miRNAs were enriched in the urinary exosome subpopulation in hypertensive patients and that low miR-146a expression in exosomes was associated with the presence of albuminuria. Thus, urinary exosome miR-146a may be a potentially useful tool for studying early renal injury in hypertension

    Relationship between IGF-1 and body weight in inflammatory bowel diseases: Cellular and molecular mechanisms involved

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    Inflammatory bowel diseases (IBD), represented by ulcerative colitis (UC) and Crohn''s disease (CD), are characterized by chronic inflammation of the gastrointestinal tract, what leads to diarrhea, malnutrition, and weight loss. Depression of the growth hormone-insulin-like growth factor-1 axis (GH-IGF-1 axis) could be responsible of these symptoms. We demonstrate that long-term treatment (54 weeks) of adult CD patients with adalimumab (ADA) results in a decrease in serum IGF-1 without changes in serum IGF-1 binding protein (IGF1BP4). These results prompted us to conduct a preclinical study to test the efficiency of IGF-1 in the medication for experimental colitis. IGF-1 treatment of rats with DSS-induced colitis has a beneficial effect on the following circulating biochemical parameters: glucose, albumin, and total protein levels. In this experimental group we also observed healthy maintenance of colon size, body weight, and lean mass in comparison with the DSS-only group. Histological analysis revealed restoration of the mucosal barrier with the IGF-1 treatment, which was characterized by healthy quantities of mucin production, structural maintenance of adherers junctions (AJs), recuperation of E-cadherin and ß-catenin levels and decrease in infiltrating immune cells and in metalloproteinase-2 levels. The experimentally induced colitis caused activation of apoptosis markers, including cleaved caspase 3, caspase 8, and PARP and decreases cell-cycle checkpoint activators including phosphorylated Rb, cyclin E, and E2F1. The IGF-1 treatment inhibited cyclin E depletion and partially protects PARP levels. The beneficial effects of IGF-1 in experimental colitis could be explained by a re-sensitization of the IGF-1/IRS-1/AKT cascade to exogenous IGF-1. Given these results, we postulate that IGF-1 treatment of IBD patients could prove to be successful in reducing disease pathology. © 2021 The Author
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