5 research outputs found
NUTRITIONAL DETERMINANTS OF METABOLIC DISEASES IN HUMANS
A high fructose intake, mainly consumed with products containing added sugars, is currently suspected to be responsible for an increase in the global prevalence of obesity and related metabolic diseases. This suspicion rests on several short-term studies showing that a high- fructose intake negatively impacts cardio-metabolic risk factors in healthy volunteers. Some studies however report that fructoseâs harmful metabolic effects can be partially prevented by other dietary or life-style related factors. Each of the two studies included in this PhD thesis aimed to investigate the effects of a candidate factor. The first of them, bariatric surgery, is considered as the most effective treatment for grade III obesity, and is known to markedly improve obesity-associated metabolic alterations. In the first study, we assessed whether Roux- en-Y gastric bypass surgery altered postprandial fructose kinetics and de novo lipogenesis, with a special focus on intestinal de novo lipogenesis and on blood lipid profiles. Our results indicate that this surgical procedure does not induce any fructose malabsorption, but drastically decreases postprandial hyperlipemia. The latter effect was observed without any decrease in intestinal de novo lipogenesis, however. Second, several studies have also shown that a high- protein intake was associated with beneficial effects on body weight, glucose homeostasis, and, more recently, on intrahepatic fat concentration in obese or in healthy subjects during short- term overfeeding experiments. In the second study, we assessed in healthy volunteers whether the short-term effects of saccharose overfeeding was modulated by the dietary protein and lipid intake. Our results indicate that the same excess saccharose and total energy intake caused a five-fold larger increase in intrahepatic fat content when associated with a low-protein, high- lipid diet than with a high-protein, low-lipid diet.
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Il est soupçonnĂ© quâune consommation excessive de fructose, principalement prĂ©sent dans notre alimentation sous forme de sucres ajoutĂ©s, pourrait ĂȘtre responsable de la rĂ©cente augmentation de la prĂ©valence mondiale dâobĂ©sitĂ© et des maladies mĂ©taboliques. Ceci repose sur de nombreuses Ă©tudes dâintervention qui montrent quâune suralimentation en fructose influe nĂ©gativement sur les marqueurs de risque mĂ©tabolique et cardiovasculaire. Pourtant, certaines Ă©tudes dĂ©montrent aussi que les effets nĂ©gatifs du fructose peuvent ĂȘtre partiellement attĂ©nuĂ©s par divers facteurs, alimentaires ou liĂ©s au mode de vie. Les Ă©tudes effectuĂ©es dans le cadre de cette thĂšse avaient pour but de prĂ©ciser lâeffet de certains de ces facteurs. La chirurgie bariatrique est actuellement considĂ©rĂ©e comme la mĂ©thode le plus efficace pour le traitement de lâobĂ©sitĂ© de degrĂ© III. De surcroit, elle est susceptible dâamĂ©liorer les anomalies mĂ©taboliques associĂ©es Ă lâobĂ©sitĂ©. Dans une premiĂšre Ă©tude, nous avons Ă©valuĂ© si le bypass gastrique selon Roux-en-Y altĂ©rait la cinĂ©tique postprandiale du fructose et la lipogenĂšse de novo. Une attention particuliĂšre a Ă©tĂ© portĂ©e Ă la lipogenĂšse intestinale de novo et aux Ă©ventuelles consĂ©quences de sa modification sur les concentrations sanguines de lipides. Les rĂ©sultats indiquent que le bypass gastrique nâentraĂźne pas de malabsorption de fructose, mais diminue lâexcursion postprandiale de triglycĂ©rides, et ce malgrĂ© une lipogenĂšse intestinale prĂ©servĂ©e. Il a aussi Ă©tĂ© rapportĂ© Ă plusieurs reprises, quâune augmentation de lâapport protĂ©ique pouvait ĂȘtre associĂ© Ă une perte de poids, une amĂ©lioration de l'homĂ©ostasie du glucose et, plus rĂ©cemment, la diminution de la quantitĂ© de graisse stockĂ©e dans le parenchyme hĂ©patique chez lâobĂšse ou dans des modĂšles expĂ©rimentaux de suralimentation chez le volontaire sain. Dans une seconde Ă©tude, nous avons donc Ă©valuĂ© si les effets dâune surcharge de courte durĂ©e en saccharose variait en fonction du contenu en protĂ©ines et lipides de lâalimentation. Les rĂ©sultats obtenus dĂ©montrent que, Ă mĂȘme surcharge en saccharose et en Ă©nergie totale, le stockage de lipides intrahĂ©patique est 5 fois plus important en prĂ©sence dâune alimentation pauvre en protĂ©ines et riche en lipide quâen prĂ©sence dâune alimentation hyper- protĂ©inĂ©e pauvre en lipides
The influence of SiO and SiO-TiO intermediate coatings on adhesion of Ti6AI4V titanium alloy : dental porcelain
Pathogenesis of Cardiovascular and Metabolic Diseases: Are Fructose-Containing Sugars More Involved Than Other Dietary Calories?
Pathogenesis of Cardiovascular and Metabolic Diseases: Are Fructose-Containing Sugars More Involved Than Other Dietary Calories?
There is increasing concern that sugar consumption may be linked to the development of metabolic and cardiovascular diseases. There is indeed strong evidence that consumption of energy-dense sugary beverages and foods is associated with increased energy intake and body weight gain over time. It is further proposed that the fructose component of sugars may exert specific deleterious effects due to its propension to stimulate hepatic glucose production and de novo lipogenesis. Excess fructose and energy intake may be associated with visceral obesity, intrahepatic fat accumulation, and high fasting and postprandial blood triglyceride concentrations. Additional effects of fructose on blood uric acid and sympathetic nervous system activity have also been reported, but their link with metabolic and cardiovascular diseases remains hypothetical. There is growing evidence that fructose at physiologically consumed doses may exert important effects on kidney function. Whether this is related to the development of high blood pressure and cardiovascular diseases remains to be further assessed
Effect of Recasted Material Addition on the Quality of Metal-Ceramic Bond: A Macro-, Micro-, and Nanostudy
Using the recasted alloys in dental prosthetics could affect the quality of the metal-ceramic bond. However, scientists, alloys producers, and prosthetists are still of different opinions. The purpose of this study was to estimate the influence of recasting of the NiCrMo alloy on the metal-ceramic bond quality. The research was carried out on macro-, micro- and nanoscales using the three-point bending test procedure and hardness tests as well as atomic force microscopy and SEM analyses. The SEM analyses showed good integrity of the metal-ceramic bond. The Ïb index of all test samples was greater than 45âMPa. The highest values were recorded for the samples made of 50% and 100% of a brand new material. SEM analysis made after the bending test confirmed good metal-ceramic bond and exhibited adhesive-cohesive fracture. The largest hardness of metal plates was found for the samples containing 50% of the recycled material. Atomic force microscopy studies showed that the alloy containing 50% of the recycled material was characterized by the highest values of surface roughness parameters