Metabolism: clinical and experimental
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Tumor necrosis factor-alpha (TNF-alpha) seems to be increased in obese subjects, suggesting its role as a proinflammatory cytokine to insulin resistance and metabolic abnormalities in obesity. The aim of this study was to evaluate the relationship between serum TNF-alpha, soluble TNF-alpha receptor 1 (sTNF-R1), TNF-alpha receptor 2 (sTNF-R2), and metabolic syndrome (MS) components and anthropometric indices in obese and non-obese adolescents. A cross-sectional study was performed on obese and non-obese adolescents. ⋯ The serum TNF-alpha was positively correlated with triglyceride (TG) and DBP, and negatively with high-density lipoprotein-cholesterol (HDLC). The sTNF-R1 and sTNF-R2 were correlated with TG and DBP, and TG, respectively. Obese compared with non-obese adolescents exhibited higher concentrations of TNF-alpha and its soluble receptors, and the higher TNF-alpha concentrations were associated with several components of MS in obese adolescents.
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Comparative Study Clinical Trial
Are peristaltic pumps as reliable as syringe pumps for metabolic research? Assessment of accuracy, precision, and metabolic kinetics.
Syringe pumps are traditionally used to infuse tracers in metabolic research because they are perceived to be more accurate and precise than peristaltic pumps. This study evaluated the accuracy (actual v programmed infusion rate) and precision (reproducibility of infusion) of a peristaltic pump (Gemini PC 2; IMED, San Diego, CA) and a syringe pump (Model 22; Harvard Apparatus, Natick, MA) for metabolic research. In one protocol, saline delivery was measured in vitro in 5 trials at 4 flow rates: 3, 30, 150, and 300 mL/h. ⋯ Glycerol Ra values were the same when tracer was infused with either a syringe or peristaltic pump on day 1 and day 2: 4.1 +/- 1.7 (syringe pump) and 4.2 +/- 1.9 (peristaltic pump) micromol. kg fat mass (FM)(-1). min(-1) on day 1; 4.2 +/- 1.2 (syringe pump) and 4.2 +/- 1.3 (peristaltic pump) micromol. kg FM(-1). min(-1) on day 2. These data demonstrate that both syringe and peristaltic pumps are very accurate and precise across a large range of flow rates. Moreover, the assessment of in vivo substrate kinetics in human subjects is the same when either pump is used to infuse isotope tracers.