The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Marcelo O Dietrich - One of the best experts on this subject based on the ideXlab platform.
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regulation of Substrate Utilization and adiposity by agrp neurons
Nature Communications, 2019Co-Authors: Joao Paulo Cavalcantidealbuquerque, Jeremy Bober, Marcelo R Zimmer, Marcelo O DietrichAbstract:The type of nutrient utilized by the organism at any given time—Substrate Utilization—is a critical component of energy metabolism. The neuronal mechanisms involved in the regulation of Substrate Utilization in mammals are largely unknown. Here, we found that activation of hypothalamic Agrp neurons rapidly altered whole-body Substrate Utilization, increasing carbohydrate Utilization, while decreasing fat Utilization. These metabolic changes occurred even in the absence of caloric ingestion and were coupled to increased lipogenesis. Accordingly, inhibition of fatty acid synthase—a key enzyme that mediates lipogenesis—blunted the effects of Agrp neuron activation on Substrate Utilization. In pair-fed conditions during positive energy balance, activation of Agrp neurons improved metabolic efficiency, and increased weight gain and adiposity. Conversely, ablation of Agrp neurons impaired fat mass accumulation. These results suggest Agrp neurons regulate Substrate Utilization, contributing to lipogenesis and fat mass accumulation during positive energy balance. Agouti-related peptide (AgRP) producing neurons regulate food intake and metabolic processes in peripheral organs. Here, the authors show that hypothalamic AgRP neurons alter whole body Substrate Utilization to favour carbohydrate usage and lipid storage.
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Rapid shift in Substrate Utilization driven by hypothalamic Agrp neurons
bioRxiv, 2016Co-Authors: Joao Paulo Cavalcanti-de-albuquerque, Jeremy Bober, Marcelo R Zimmer, Marcelo O DietrichAbstract:Agrp neurons drive feeding. To what extend these neurons participate in the regulation of other homeostatic processes is not well understood. We investigated the role of Agrp neurons in Substrate Utilization in mice. Activation of Agrp neurons was sufficient to rapidly increase RER and carbohydrate Utilization, while decreasing fat Utilization. These metabolic changes were linearly correlated with carbohydrates ingested, but not protein or fat ingestion. However, even in the absence of ingestive behaviors, activation of Agrp neurons led to changes in Substrate Utilization in well-fed mice. These effects were coupled to metabolic shifts towards lipogenesis. Inhibition of fatty acid synthetase (FAS) blunted the effects of Agrp neurons on Substrate Utilization. Finally, Agrp neurons controlled peripheral metabolism, but not food intake, via β3-adrenergic receptor signaling in fat tissues. These results reveal a novel component of Agrp neuron-mediate metabolism regulation that involves sympathetic activity on fat compartments to shift metabolism towards lipogenesis.
Larry S. Jefferson - One of the best experts on this subject based on the ideXlab platform.
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energy metabolism nitrogen balance and Substrate Utilization in critically ill children
The American Journal of Clinical Nutrition, 2001Co-Authors: Jorge A Cossbu, David Walding, William J. Klish, Fernando Stein, Obrian E Smith, Larry S. JeffersonAbstract:BACKGROUND: Critically ill patients are characterized by a hypermetabolic state, a catabolic response, higher nutritional needs, and a decreased capacity for Utilization of parenteral Substrate. OBJECTIVE: We sought to analyze the relation between a patient's metabolic state and their nutritional intake, Substrate Utilization, and nitrogen balance (NB) in mechanically ventilated, critically ill children receiving parenteral nutrition. DESIGN: This was a cross-sectional study in which resting energy expenditure (REE) and NB were measured and Substrate Utilization and the metabolic index (MI) ratio (REE/expected energy requirements) were calculated. RESULTS: Thirty-three children (mean age: 5 y) participated. Their average REE was 0.23 +/- 0.10 MJ x kg(-1) x d(-1) and their average MI was 1.2 +/- 0.5. Mean energy intake, protein intake, and NB were 0.25 +/- 0.14 MJ x kg(-1) x d(-1), 2.1 +/- 1 g x kg(-1) x d(-1), and -89 +/- 166 mg x kg(-1) x d(-1), respectively. Patients with an MI >1.1 (n = 19) had a higher fat oxidation than did patients with an MI <1.1 (n = 14; P < 0.05). Patients with lipogenesis (n = 13) had a higher carbohydrate intake than did patients without lipogenesis (n = 20; P < 0.05). Patients with a positive NB (n = 12) had a higher protein intake than did patients with a negative NB (n = 21; P < 0.001) and lower protein oxidation (P < 0.01). CONCLUSIONS: Critically ill children are hypermetabolic and in negative NB. In this population, fat is used preferentially for oxidation and carbohydrate is utilized poorly. A high carbohydrate intake was associated with lipogenesis and less fat oxidation, a negative NB was associated with high oxidation rates for protein, and a high protein intake was associated with a positive NB.
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energy metabolism nitrogen balance and Substrate Utilization in critically ill children
The American Journal of Clinical Nutrition, 2001Co-Authors: Jorge A Cossbu, David Walding, William J. Klish, Fernando Stein, Obrian E Smith, Larry S. JeffersonAbstract:Background: Critically ill patients are characterized by a hypermetabolic state, a catabolic response, higher nutritional needs, and a decreased capacity for Utilization of parenteral Substrate. Objective: We sought to analyze the relation between a patient's metabolic state and their nutritional intake, Substrate Utilization, and nitrogen balance (NB) in mechanically ventilated, critically ill children receiving parenteral nutrition. Design: This was a cross-sectional study in which resting energy expenditure (REE) and NB were measured and Substrate Utilization and the metabolic index (MI) ratio (REElexpected energy requirements) were calculated. Results: Thirty-three children (mean age: 5 y) participated. Their average REE was 0.23 ± 0.10 MJ.kg -1 .d -1 and their average MI was 1.2 ± 0.5. Mean energy intake, protein intake, and NB were 0.25 ± 0.14 MJ.kg -1 .d -1 , 2.1 ± 1 g.kg -1 .d -1 , and -89 ± 166 mg.kg -1 .d -1 , respectively. Patients with an MI > 1.1 (n = 19) had a higher fat oxidation than did patients with an MI < 1.1 (n = 14; P < 0.05). Patients with lipogenesis (n = 13) had a higher carbohydrate intake than did patients without lipogenesis (n = 20; P < 0.05). Patients with a positive NB (n = 12) had a higher protein intake than did patients with a negative NB (n = 21; P < 0.001) and lower protein oxidation (P < 0.01). Conclusions: Critically ill children are hypermetabolic and in negative NB. In this population, fat is used preferentially for oxidation and carbohydrate is utilized poorly. A high carbohydrate intake was associated with lipogenesis and less fat oxidation, a negative NB was associated with high oxidation rates for protein, and a high protein intake was associated with a positive NB.
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Substrate Utilization in critically ill children |[dagger]| 188
Pediatric Research, 1998Co-Authors: Jorge A. Coss-bu, Larry S. Jefferson, David Walding, Yadin David, E. O'brian Smith, William J. KlishAbstract:Background:Critically ill patients usually are catabolic, as assessed by nitrogen balance (NB) studies. When indirect calorimetry (IC) and total urinary nitrogen (TUN) are done simultaneously; carbohydrate (CHO), protein (PROT), and fat Utilization can be calculated. Methods: This study measured NB and Substrate Utilization in 20 critically ill children(mean PRISM and TISS scores of 8±5 and 30±7 respectively) on mechanical ventilation (MV), in relation to their resting energy expenditure(REE) and caloric intake (Cal In.). All patients were receiving TPN or enteral nutrition when evaluated. REE was measured by IC (mass spectrometry) and TUN by the Kjeldahl method. Expected energy requirements (EER) were obtained from Talbot's tables. REE/EER index > 1.1 defined a hypermetabolic state. Substrate Utilization rates were calculated using the Consolazio formulas. Studies were done at the time of the first evaluation and repeated (n=48). The correlation was measured by Pearson's correlation coefficient. Values are mean±SD.
Joao Paulo Cavalcantidealbuquerque - One of the best experts on this subject based on the ideXlab platform.
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regulation of Substrate Utilization and adiposity by agrp neurons
Nature Communications, 2019Co-Authors: Joao Paulo Cavalcantidealbuquerque, Jeremy Bober, Marcelo R Zimmer, Marcelo O DietrichAbstract:The type of nutrient utilized by the organism at any given time—Substrate Utilization—is a critical component of energy metabolism. The neuronal mechanisms involved in the regulation of Substrate Utilization in mammals are largely unknown. Here, we found that activation of hypothalamic Agrp neurons rapidly altered whole-body Substrate Utilization, increasing carbohydrate Utilization, while decreasing fat Utilization. These metabolic changes occurred even in the absence of caloric ingestion and were coupled to increased lipogenesis. Accordingly, inhibition of fatty acid synthase—a key enzyme that mediates lipogenesis—blunted the effects of Agrp neuron activation on Substrate Utilization. In pair-fed conditions during positive energy balance, activation of Agrp neurons improved metabolic efficiency, and increased weight gain and adiposity. Conversely, ablation of Agrp neurons impaired fat mass accumulation. These results suggest Agrp neurons regulate Substrate Utilization, contributing to lipogenesis and fat mass accumulation during positive energy balance. Agouti-related peptide (AgRP) producing neurons regulate food intake and metabolic processes in peripheral organs. Here, the authors show that hypothalamic AgRP neurons alter whole body Substrate Utilization to favour carbohydrate usage and lipid storage.
Wolfgang Babel - One of the best experts on this subject based on the ideXlab platform.
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determination of Substrate Utilization patterns of soil microbial communities an approach to assess population changes after hydrocarbon pollution
FEMS Microbiology Ecology, 1995Co-Authors: Lothar Wunsche, Lutz Bruggemann, Wolfgang BabelAbstract:Changes in hydrocarbon content in soils resulted in characteristic shifts of the Substrate Utilization patterns as tested with the Biolog system. The altered patterns of Substrate Utilization corresponded to similar changes in abundance of hydrocarbon-utilizing bacteria and the occurrence of specific bacterial groups in the soils. Substrate Utilization patterns as recorded with the Biolog system are suitable for rapidly assessing dynamics of autochthonous soil communities and evaluating their biodegradative potential.
Michael C Riddell - One of the best experts on this subject based on the ideXlab platform.
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influence of age and pubertal status on Substrate Utilization during exercise with and without carbohydrate intake in healthy boys
Applied Physiology Nutrition and Metabolism, 2007Co-Authors: Brian W Timmons, Oded Baror, Michael C RiddellAbstract:Substrate Utilization during exercise is known to differ between children and adults, but whether these differences are related to pubertal status is unclear. The objective of this study was to investigate the effects of pubertal status on endogenous (CHOendo) and orally ingested exogenous (CHOexo) carbohydrate and fat oxidation rates during exercise. Twenty boys at the same chronological age (12 y) were divided into three pubertal groups (pre-pubertal, PP: n = 7; early-pubertal, EP: n = 7; mid- to late-pubertal, M-LP: n = 6) and consumed either a placebo or 13C-enriched 6% CHO drink while cycling for 60 min at ~70% of their maximal aerobic power (VO2 max). Another group of 14-year-old boys (pubertal, n = 9) completed all procedures. Substrate Utilization was calculated for the final 15 min of exercise using indirect calorimetry and stable isotope methodology. CHOexo decreased fat (p < 0.001) and increased total CHO (p < 0.001) oxidation, irrespective of group. Fat oxidation was higher (p = 0.01) in young...
