Effects of fructose-containing caloric sweeteners on resting energy expenditure and energy efficiency: a review of human trials.

Epidemiological studies indicate that the consumption of fructose-containing caloric sweeteners (FCCS: mainly sucrose and high-fructose corn syrup) is associated with obesity. The hypothesis that FCCS plays a causal role in the development of obesity however implies that they would impair energy balance to a larger extent than other nutrients, either by increasing food intake, or by decreasing energy expenditure. We therefore reviewed the literature comparing a) diet-induced thermogenesis (DIT) after ingestion of isocaloric FCCS vs glucose meals, and b) basal metabolic rate (BMR) or c) post-prandial energy expenditure after consuming a high FCCS diet for > 3 days vs basal,weight-maintenance low FCCS diet. Nine studies compared the effects of single isocaloric FCCS and glucose meals on DIT; of them, six studies reported that DIT was significantly higher with FCCS than with glucose, 2 reported a non-significant increase with FCCS, and one reported no difference. The higher DIT with fructose than glucose can be explained by the low energy efficiency associated with fructose metabolism. Five studies compared BMR after consumption of a high FCCS vs a low FCCS diet for > 3 days. Four studies reported no change after 4-7 day on a high FCCS diet, and only one study reported a 7% decrease after 12 week on a high FCCS diet. Three studies compared post-prandial EE after consumption of a high FCCS vs a low FCCS diet for > 3 days, and did not report any significant difference. One study compared 24-EE in subjects fed a weight-maintenance diet and hypercaloric diets with 50% excess energy as fructose, sucrose and glucose during 4 days: 24-EE was increased with all 3 hypercaloric diets, but there was no difference between fructose, sucrose and glucose. We conclude that fructose has lower energy efficiency than glucose. Based on available studies, there is presently no hint that dietary FCCS may decrease EE. Larger, well controlled studies are however needed to assess the longer term effects of FCCS on EE.

Dual-energy CT behavior of heroin, cocaine, and typical adulterants.

PURPOSE: To investigate the dual-energy CT behavior of cocaine and heroin and of typical adulterants, and to evaluate the elemental composition of pure cocaine and heroin compared with cocaine and heroin in bodypacks. METHODS: Pure heroin and pure synthetic cocaine samples, eight different adulterants, and in each case ten different bodypacks containing cocaine or heroin, were imaged at 80, 100, 120, and 140 kVp in a dual source CT system at two different degrees of compression. Two radiologists, blinded to the samples, measured the attenuation. The dual-energy index (DEI) was calculated. We performed atomic mass spectrometry for the elemental analysis of pure cocaine, pure heroin, and heroin and cocaine in bodypacks, and 140 kVp in a dual-source CT system. RESULTS: Inter- and intra-observer agreement for attenuation measurements was good (r = 0.61-0.72; p < 0.01). The cocaine bodypacks had a positive DEI of 0.029, while the pure drugs and the heroin bodypacks had a negative DEI (-0.051 to -0.027). Levamisole was the only substance which expressed a positive DEI of 0.011, while the remaining adulterants had negative DEIs ranging between -0.015 and -0.215. Atomic mass spectrometry revealed a concentration of tin in the cocaine bodypack that was 67 times higher than in the pure synthetic cocaine sample. CONCLUSIONS: The different DEIs of bodypacks containing cocaine and heroin allow them to be distinguished with dual-energy CT. Although the material properties of pure cocaine, pure heroin, or common drug extenders do not explain the differences in DEI, tin contamination during illicit natural cocaine production may be a possible explanation.

Effect of a novel beta-adrenoceptor agonist (Ro 40-2148) on resting energy expenditure in obese women.

The aim of this single-blind, placebo-controlled study was to investigate the effects of the new beta-adrenergic compound Ro 40-2148 on resting energy expenditure (REE) at rest and after an oral glucose load in non-diabetic obese women before and after two weeks of treatment. After one week of placebo administration and after an overnight fast and one hour rest, REE and glucose and lipid oxidation rates were measured by indirect calorimetry (hood system) before and for 6 h after a single dose of placebo solution. A 75 g oral glucose tolerance test (OGTT) was performed during this period starting 90 min after the placebo administration. During the following two weeks, using a randomization design, six patients received Ro 40-2148 at a dose of 400 mg diluted in 100 ml water twice a day (i.e. 800 mg per day), while six others continued with the placebo administration. The same tests and measurements were repeated after two weeks, except for the treatment group which received the drug instead of the placebo. The 14-day period of drug administration did not increase REE measured in post-absorptive conditions. Similarly, there was no acute effect on REE of a 400 mg dose of Ro 40-2148. In contrast, glucose-induced thermogenesis was significantly increased after two weeks in the treatment group (means +/- s.e.m.: 3.7 +/- 1.3%, P = 0.047), while no change was observed in the placebo group (-0.8 +/- 0.7%, not significant). Since there was no significant change in the respiratory quotient, the increase in energy expenditure observed in the treatment group was due to stimulation of both lipid and glucose oxidation. The drug induced no variations in heart rate, blood pressure, axillary temperature or in plasma glucose, insulin and free fatty acid levels. In conclusion, this study shows that Ro 40-2148 activates glucose-induced thermogenesis in obese non-diabetic patients.

Energy consumption of European and African shrews

Is the extremely high oxygen consumption of shrews due to an unusually high basal metabolism? In an attempt to answer this long-standing question, we have measured the oxygen consumption of 13 species of shrews of different origin: from Europe - Sorex araneus, S. Minutus, Neomys fodiens, Crocidura russula, and Suncus etruscus; from Africa - Crocidura bottegi, C. bicolor, C. jouvenetae; C. poensis, C. theresae, C. Wimmeri, C. flavescens, and C. giffardi, The measurements, taken over a period of 20-30 minutes, were made in small, closed-system chambers at 25°C. The metabolic rat our shrews of the subfamily Soricinae lies between the eman and minimum values of the Soricini (M=126.2 W0.52 cal/h and M=82.6 W0.53 cal/h, respectively), as recorded in the literature. Zhe average for the African Crocidurinae is much lower (M= 43.6 W0.67). The metabolic rate of the European Croccidura russula agrees with that of the African species. Thus, the Crocidurinae are characterized by a relatively low metabolic rate; the Soricinae, and in particular the tribe of the Soricini, by an extremely high metabolic rate. The tribes Neomyini and Blarinini occupy an intermediate position. These differences are also to be found at the level of the basal metabolism. This main difference between the two sub-families can most likely be explained by evolution in geographical isolation under differential climatic conditions: the Crocidurinae having evolved in tropical Africa and the Soricinae in temperate Eurasia

Fragmentation energy in rock avalanches

La fragmentation est un des mécanismes opérant lors d'avalanche rocheuses. La quantification de l'énergie associée à ce mécanisme permettrait d'apprécier l'influence de celui-ci sur la phase post-rupture d'une avalanche rocheuse. Dans cet article, les distributions des tailles des blocs du massif rocheux et des débris sont présentées et comparées pour neuf cas d'avalanches rocheuses : cinq dans les montagnes Rocheuses canadiennes et quatre dans les Alpes européennes. Des degrés de fragmentation ont pu être estimés. Pour évaluer l'énergie de fragmentation, deux méthodes on été examinées : l'une est basée sur l'énergie de concassage et l'autre est basée sur l'énergie de sautage utilisée dans le domaine minier. Les résultats obtenus portent à croire qu'il y aurait une relation entre l'indice de réduction de taille (Rr = D50/d50) et l'énergie potentielle par unité de volume, normalisée par la résistance au double poinçonnement (?HG/?c). Les énergies de fragmentation calculées pour les neuf cas étudiés donne en moyenne 20 % de l'énergie potentielle. Une relation empirique entre Rr et ?HG/?c est proposée, et est par la suite utilisée pour définir un indice de désintégration (ID). Cet indice reflète la physique du processus de désintégration puisqu'il considère que l'indice de réduction de taille est fonction de l'énergie dissipée et de la résistance de la roche. Ces facteurs connus depuis longtemps n'avaient jamais été présentés d'une façon cohérente pour des cas d'avalanches rocheuses.Mots clés : avalanches rocheuses, désintégration, énergie de fragmentation, Rocheuses canadiennes, Alpes européennes.

Effect of ethanol on energy expenditure.

The thermogenic response induced by ethanol ingestion in humans has not been extensively studied. This study was designed to determine the thermic effect of ethanol added to a normal diet in healthy nonalcoholic subjects, using indirect calorimetry measurements over a 24-h period in a respiration chamber. The thermic effect of ethanol was also measured when ethanol was ingested in the fasting state, using a ventilated hood system during a 5-h period. Six subjects ingested 95.6 +/- 1.8 (SE) g ethanol in 1 day partitioned over three meals; there was a 5.5 +/- 1.2% increase in 24-h energy expenditure compared with a control day in which all conditions were identical except that no ethanol was consumed. The calculated ethanol-induced thermogenesis (EIT) was 22.5 +/- 4.7% of the ethanol energy ingested. Ingestion of 31.9 +/- 0.6 g ethanol in the fasting state led to a 7.4 +/- 0.6% increase in energy expenditure over baseline values, and the calculated EIT was 17.1 +/- 2.2%. It is concluded that in healthy nonalcoholic adults ethanol elicits a thermogenic response equal to approximately 20% of the ethanol energy. Thus the concept of the apparently inefficient utilization of ethanol energy is supported by these results which show that only approximately 80% of the ethanol energy is used as metabolizable energy for biochemical processes in healthy nonalcoholic moderate ethanol consumers.

Impact of physical activity on energy balance, food intake and choice in normal weight and obese children in the setting of acute social stress: a randomized controlled trial.

BACKGROUND: Psychological stress negatively influences food intake and food choices, thereby contributing to the development of childhood obesity. Physical activity can also moderate eating behavior and influence calorie intake. However, it is unknown if acute physical activity influences food intake and overall energy balance after acute stress exposure in children. We therefore investigated the impact of acute physical activity on overall energy balance (food intake minus energy expenditure), food intake, and choice in the setting of acute social stress in normal weight (NW) and overweight/obese (OW/OB) children as well as the impact of psychological risk factors. METHOD: After receiving written consent from their parents, 26 NW (BMI < 90(th) percentile) and 24 7-to 11-year-old OW (n = 5)/OB (n = 19, BMI ≥ 90(th) percentile) children were randomly allocated using computer-generated numbers (1:1, after stratification for weight status) to acute moderate physical or to sedentary activity for 30 min. Afterwards, all children were exposed to an acute social stressor. Children and their parents completed self-report questionnaires. At the end of the stressor, children were allowed to eat freely from a range of 12 different foods (6 sweet/6 salty; each of low/high caloric density). Energy balance, food intake/choice and obesity-related psychological risk factors were assessed. RESULTS: Lower overall energy balance (p = 0.019) and a decreased choice of low density salty foods (p < 0.001) in NW children compared with OW/OB children was found after acute moderate physical activity but not sedentary activity. Independent of their allocation, OW/OB children ate more high density salty foods (104 kcal (34 to 173), p = 0.004) following stress. They scored higher on impulsive behavior (p = 0.005), restrained eating (p < 0.001) and parental corporal punishment (p = 0.03), but these psychological factors were not related to stress-induced food intake/choice. Positive parenting tended to be related to lower intake of sweet high density food (-132 kcal, -277 to 2, p = 0.054). CONCLUSIONS: In the setting of stress, acute moderate physical activity can address energy balance in children, a benefit which is especially pronounced in the OW/OB. Positive parenting may act as a protective factor preventing stress-induced eating of comfort food. TRIAL REGISTRATION: clinicaltrials.gov NCT01693926 The study was a pilot study of a project funded by the Swiss National Science Foundation (CRSII3_147673).

Transformation of a microprolactinoma into a mixed growth hormone and prolactin-secreting pituitary adenoma.

Combined prolactin (PRL) and growth hormone (GH) secretion by a single pituitary tumor can occur in approximately 5% of cases. However, in all previously reported patients, combined secretion of both hormones was present at the time of diagnosis. Here we describe a patient initially diagnosed with a pure prolactin-secreting microadenoma, who experienced the progressive apparition of symptomatic autonomous GH secretion while on intermittent long term dopamine agonist therapy. She was operated on, and immunohistochemical analysis of tumor tissue confirmed the diagnosis of pituitary adenoma with uniform co-staining of all cells for both GH and PRL. This patient represents the first documented occurrence of asynchronous development of combined GH and PRL secretion in a pituitary adenoma. Although pathogenic mechanisms implicated remain largely speculative, it emphasizes the need for long term hormonal follow up of patients harboring prolactinomas.

Variability of resting energy expenditure in healthy volunteers during fasting and continuous enteral feeding.

The magnitude of variability in resting energy expenditure (REE) during the day was assessed in nine healthy young subjects under two nutritional conditions: 1) mixed nutrient (53% carbohydrate, 30% fat, 17% protein) enteral feeding at an energy level corresponding to 1.44 REE; and 2) enteral fasting, with only water allowed. In each subject, six 30-min measurements of REE were performed using indirect calorimetry (hood system) at 90-min intervals from 9 AM to 5 PM. The mean REE and respiratory quotient were significantly (p less than .01) greater during feeding than during fasting (1.08 +/- 0.07 [SEM] vs. 1.00 +/- 0.06 kcal/min and 0.874 +/- 0.007 vs. 0.829 +/- 0.008 kcal/min, respectively). Mean postprandial thermogenesis was 4.9 +/- 0.4% of metabolizable energy administered. The intraindividual variability of REE throughout the day, expressed as the coefficient of variation, ranged from 0.7% to 2.0% in the fasting condition and from 1.2% to 4.1% in the feeding condition. There was no significant difference between the REE measured in the morning and that determined in the afternoon.

In vivo transformation of mouse conventional CD8alpha+ dendritic cells leads to progressive multisystem histiocytosis

Division and proliferation of dendritic cells (DCs) have been proposed to contribute to homeostasis and to prolonged antigen presentation. Whether abnormal proliferation of dendritic cells causes Langerhans cell histiocytosis (LCH) is a highly debated topic. Transgenic expression of simian virus 40 (SV40) T antigens in mature DCs allowed their transformation in vivo while maintaining their phenotype, function, and maturation capacity. The transformed cells were differentiated splenic CD8 alpha-positive conventional dendritic cells with increased Langerin expression. Their selective transformation was correlated with higher steady-state cycling compared with CD8 alpha-negative DCs in wild-type and transgenic mice. Mice developed a DC disease involving the spleen, liver, bone marrow, thymus, and mesenteric lymph node. Surprisingly, lesions displayed key immunohistologic features of Langerhans cell histiocytosis, including expression of Langerin and absence of the abnormal mitoses observed in Langerhans cell sarcomas. Our results demonstrate that a transgenic mouse model with striking similarities to aggressive forms of multisystem histiocytosis, such as the Letterer-Siwe syndrome, can be obtained by transformation of conventional DCs. These findings suggest that conventional DCs may cause some human multisystem LCH. They can reveal shared molecular pathways for human histiocytosis between humans and mice

Direct simulation of interface dynamics: linking capillary pressure, interfacial area and surface energy

We perform direct numerical simulations of drainage by solving Navier- Stokes equations in the pore space and employing the Volume Of Fluid (VOF) method to track the evolution of the fluid-fluid interface. After demonstrating that the method is able to deal with large viscosity contrasts and to model the transition from stable flow to viscous fingering, we focus on the definition of macroscopic capillary pressure. When the fluids are at rest, the difference between inlet and outlet pressures and the difference between the intrinsic phase average pressure coincide with the capillary pressure. However, when the fluids are in motion these quantities are dominated by viscous forces. In this case, only a definition based on the variation of the interfacial energy provides an accurate measure of the macroscopic capillary pressure and allows separating the viscous from the capillary pressure components.