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Seematter, G., E. Guenat, P. Schneiter, C. Cayeux, E. Jequier, and L. Tappy. Effects of mental stress on insulin-mediated glucose metabolism and energy expenditure in lean and obese women. Am J Physiol Endocrinol Metab 279: E799-E805, 2000.--The effects of the sympathetic activation elicited by a mental stress on insulin sensitivity and energy expenditure ([Vo.sub.2]) were studied in 11 lean and 8 obese women during a hyperinsulinemic-euglycemic clamp. Six lean women were restudied under nonselective [Beta]-adrenergic blockade with propranolol to determine the role of [Beta]-adrenoceptors in the metabolic response to mental stress. In lean women, mental stress increased [Vo.sub.2] by 20%, whole body glucose utilization ([6,6-[sup.2][H.sup.2]]glucose) by 34%, and cardiac index (thoracic bioimpedance) by 25%, whereas systemic vascular resistance decreased by 24%. In obese women, mental stress increased energy expenditure as in lean subjects, but it neither stimulated glucose uptake nor decreased systemic vascular resistance. In the six lean women who were restudied under propranolol, the rise in [Vo.sub.2], glucose uptake, and cardiac output and the decrease in systemic vascular resistance during mental stress were all abolished. It is concluded that 1) in lean subjects, mental stress stimulates glucose uptake and energy expenditure and produces vasodilation; activation of [Beta]-adrenoceptors is involved in these responses; and 2) in obese patients, the effects of mental stress on glucose uptake and systemic vascular resistance, but not on energy expenditure, are blunted. obesity; sympathetic nervous system; thermogenesis; glucose uptake; insulin resistance

Purpose of Review: The current article presents recent findings on the metabolic effects of fructose., Recent Findings: Fructose has always been considered as a simple 'caloric' hexose only metabolized by splanchnic tissues. Nevertheless, there is growing evidence that fructose acts as a second messenger and induces effects throughout the human body., Summary: Recent discoveries made possible with the evolution of technology have highlighted that fructose induces pleiotropic effects on different tissues. The fact that all these tissues express the specific fructose carrier GLUT5 let us reconsider that fructose is not only a caloric hexose, but could also be a potential actor of some behaviors and metabolic pathways. The physiological relevance of fructose as a metabolic driver is pertinent regarding recent scientific literature.

Background: The purpose of this study was to confirm the prognostic value of pancreatic stone protein (PSP) in patients with severe infections requiring ICU management and to develop and validate a model to enhance mortality prediction by combining severity scores with biomarkers., Methods: We enrolled prospectively patients with severe sepsis or septic shock in mixed tertiary ICUs in Switzerland (derivation cohort) and Brazil (validation cohort). Severity scores (APACHE [Acute Physiology and Chronic Health Evaluation] II or Simplified Acute Physiology Score [SAPS] II) were combined with biomarkers obtained at the time of diagnosis of sepsis, including C-reactive-protein, procalcitonin (PCT), and PSP. Logistic regression models with the lowest prediction errors were selected to predict in-hospital mortality., Results: Mortality rates of patients with septic shock enrolled in the derivation cohort (103 out of 158) and the validation cohort (53 out of 91) were 37% and 57%, respectively. APACHE II and PSP were significantly higher in dying patients. In the derivation cohort, the models combining either APACHE II, PCT, and PSP (area under the receiver operating characteristic curve [AUC], 0.721; 95% CI, 0.632-0.812) or SAPS II, PCT, and PSP (AUC, 0.710; 95% CI, 0.617-0.802) performed better than each individual biomarker (AUC PCT, 0.534; 95% CI, 0.433-0.636; AUC PSP, 0.665; 95% CI, 0.572-0.758) or severity score (AUC APACHE II, 0.638; 95% CI, 0.543-0.733; AUC SAPS II, 0.598; 95% CI, 0.499-0.698). These models were externally confirmed in the independent validation cohort., Conclusions: We confirmed the prognostic value of PSP in patients with severe sepsis and septic shock requiring ICU management. A model combining severity scores with PCT and PSP improves mortality prediction in these patients.

Despite some progress, the mortality of severe sepsis and septic shock remains high. Immunotherapy directed against inflammatory mediators failed, but new treatments more specifically tailored to individual situations are actively investigated. C-reactive protein (CRP) and procalcitonin (PCT) have not demonstrated to be useful for individual prognostic stratification. New biomarkers such as pancreatic stone protein (PSP) or growth arrest specific protein 6 (Gas6) could improve this prediction. Combined with the clinical course, "PCT" allows to tailor individually the duration of antibiotic therapy in ICU patients. This still contested innovative approach significantly reduces overall exposure to antibiotics.

Objective: To assess the short-term consequences of carbohydrate or fat overfeeding or of food restriction on the metabolic effects of mental stress in healthy lean women., Research Methods and Procedures: The effects of a sympathetic activation elicited by mental stress were evaluated in a group of healthy women after standardized isocaloric feeding (ISO) or after a 3-day overfeeding with 40% excess calories as either carbohydrate overfeeding (CHO OF) or fat overfeeding (FAT OF). Oxygen consumption rate (VO(2)) was measured as an index of energy expenditure, and subcutaneous glycerol concentrations were monitored with microdialysis. The same measurements were performed in another group of healthy women after ISO and after a 3-day period of underfeeding with a protein sparing modified fast (UF)., Results: In all conditions, mental stress significantly increased heart rate, blood pressure, plasma norepinephrine and epinephrine concentrations, and VO(2), and produced a nonsignificant increase in subcutaneous glycerol concentrations. CHO OF and FAT OF did not alter the effects of mental stress on VO(2) and subcutaneous glycerol concentrations. In contrast, UF increased basal VO(2) but significantly reduced its stimulation by mental stress. UF also enhanced the increase in subcutaneous glycerol concentrations during mental stress., Discussion: UF reduces the stimulation of energy expenditure and enhances lipolysis during sympathetic activation. These adaptations may be involved in mobilization of endogenous fat while limiting weight loss. In contrast, short-term overfeeding fails to alter the sympathetic control of energy expenditure and lipolysis.