<p>Sarcopenia is the age-associated loss of muscle mass and strength. Studies have shown that combining resistance training with high protein intake increases muscle mass and strength in older adults. Women are at higher risk than men of sarcopenia. Thus, it is essential to find interventions to lessen women’s risk of losing muscle mass with aging. However, limited studies combine a specific higher-protein diet and a resistance training program in older women to determine skeletal muscle responses. This study aimed to assess the impact of a 12-week resistance training program with a high protein lean beef diet on skeletal muscle mass, strength, and quality in older women compared to a normal protein diet or a high protein diet composed of a lesser amount of beef. </p> <p>The study included three diets; a USDA recommended protein diet (0.8 g/kg/day), a high protein lean beef diet (1.4 g/kg/day), and a high protein diet composed of lesser beef (1.4 g/kg/day). Sixteen subjects were included in the study. The resistance training program consisted of leg extension, leg press, leg curl, chest press, and seated row. Muscle strength was determined by one-repetition maximum assessment at weeks one, six, and twelve. In addition, subjects underwent an MRI pre- and post-intervention to assess quadriceps volume and intermuscular adipose tissue (IMAT). Muscle quality was defined as the leg extension one-repetition maximum over the quadriceps volume. </p> <p>Muscle strength, muscle quality, and quadriceps volume increased with training in all three diet groups (P<0.05, main effect of time). No difference in muscle strength, quality, or quadriceps volume was found between the diet groups. IMAT decreased in all diet groups (P<0.05, main effect of time), but no differences were seen between the diet groups. These findings suggest that the 12-weeks of resistance training increased skeletal muscle strength, quality, and mass, independent of the normal protein or high protein diet and the source of protein in the diet.</p>

Doctor of Philosophy / Department of Human Nutrition / Mark D. Haub / Background: Mixed Martial Arts (MMA) is a growing sport that places competitors into specific weight classes to level the competition field. Athletes “cut weight” to compete in a weight class lower than their “walk around” weight. Techniques for cutting weight include dehydration, starvation and exercise in hot environments jeopardizing health and performance. Higher-protein diets (HPD) have been shown to improve weight loss by increasing satiety, thermogenesis, decreasing total energy intake, and maintain lean mass during periods of energy deficiency, such as weight loss. Research regarding the impact of HPD on performance is limited and conflicting. Specific Aims: The central hypothesis for this study was: HPD diets will elicit greater weight loss and enhance body composition compare to tradition low-fat diets in non-obese, active individuals. The three specific aims of this study are: 1) examine the effects of HPD on weight loss, 2) evaluate the impact of HPD of athletic performance, and 3) determine the effectiveness of HPD for accelerated weight loss. Methods: Military personnel participating in the Combatives program were recruited. Participants were assigned a HPD (40% CHO, 30% PRO, 30% fat), traditional low-fat, high-carbohydrate diet (65% CHO, 15% PRO, 20% fat), or an ad libitum diet for 12-day to 6-weeks depending on their training program. Fields tests for pre- and post-intervention measures of performance included: vertical jump and leg power index to measure explosive power, 600 meter shuttle run for anaerobic capacity and 1.5 mile run for aerobic capacity. Pre- and post-intervention of weight and body composition were determined using dual energy x-ray absorptiometry. Diet analysis software was used to determine nutrient intakes during the study. SPSS statistical software was used to determine descriptive statistics, paired t-tests, Pearson’s Correlations and one-way ANOVA. Results & Conclusions: Due to the unanticipated high rate of dropout, statistical significance was difficult to determine, however, there was a trend for the HPD to elicit fat-free mass retention and it not negatively impact performance. Discrepancies in energy and nutrient intake made dietary comparison difficult. Future studies with larger samples and greater dietary control are needed to further evaluate the research goals of this study.

Despite inconsistent results in the literature, high protein diets are being promoted for the management of metabolic syndrome parameters primarily due to their proposed favorable effects on weight loss. Therefore, lean and fa/fa Zucker rats were given normal and high protein diets with varying protein sources for 12 weeks. A high protein diet with a mixture of animal and plant protein sources was the most effective for improving metabolic syndrome parameters, specifically insulin resistance and hepatic steatosis. A high protein soy diet was the second most effective diet, while a high protein casein diet demonstrated no benefits compared to the other two high protein diets and minimal benefits compared to a normal protein casein diet. Interestingly, high protein diets did not affect body weight regardless of protein source. These findings suggest that the source of protein within a high protein diet is critical for improving metabolic syndrome parameters and that improvements can be observed independent of weight loss.

Une alimentation HP permet une importante diminution de la prise alimentaire, chez l’Homme et l’animal, par rapport à une alimentation STD. Les précédents travaux du laboratoire montrent que le mécanisme d’action des protéines implique une induction de la PIG chez le rat en période post-absorptive. Ce glucose, libéré et détecté dans la veine porte, permet l’activation de noyaux hypothalamiques impliqués dans la régulation des sensations de satiété. L’objectif de ce travail consistait à mettre en évidence le type de peptides pouvant induire la PIG en régime HP et d’essayer de découvrir leur mécanisme d’action. L’activité de la Glc6Pase et de l’expression des protéines Glc6Pase et PEPCK ont été quantifiées chez des rats nourris en régime STD ou HP et perfusés avec des perfusions d’acides aminés, de peptides µ-opioïdes et des solutions de di- ou tri-peptides. Les résultats montrent que le même mécanisme d’action est utilisé par les protéines et les antagonistes µ-opioïdes pour induire la PIG. Des expériences de dénervation portale et une étude immunohistochimique ont démontré la présence de récepteurs µ-opioïdes dans la veine porte probablement impliqués dans cette induction. Des perfusions de di ou tri-peptides chez le rat ont démontré que la PIG était induite par tous les di ou tri-peptides testés. L’étude phénotypique de la souris KO µ-opioïde nourrie en régime STD, HP ou ayant subi des perfusions portales de di ou tri-peptides, ont confirmé que la PIG pouvait être induite par des di ou tri-peptides et que leur mécanisme d’action nécessitait la présence de récepteurs µ-opioïdes. Cette étude suggère que tous les di- ou tri-peptides produits par la dégradation des protéines pourraient induire la PIG par un mécanisme dépendant des récepteurs µ-opioïdes / Protein feeding promotes an important decrease of food intake in humans and animals, compared on chow diet. Previous data show that this mechanism implicates intestinal glucose production (IPG) induction in rat during the post-absorptive time. Glucose released and detected into the portal vein produces an activation of hypothalamic nuclei implicated in the regulation of satiety sensations. The aim of this study was to highlight peptides which could induce IPG on HP diet and try to discoverer them mechanism. Quantification of Glc6Pase and protein expression of Glc6Pase and PEPCK were assessed in rats fed on chow or HP diet and infused with amino acids, µ-opioïd peptides and di- or tri-peptides. Our results show that the same mechanism is shared by both proteins and µ-opioïd antagonists to induce IGP. Experiments of portal vein denervation and an immunochemistry study showed that µ-opioïd receptors are present in the portal vein, probably implicated in this induction. Di or tri-peptides infusions in rat exhibited that the IGP was induced by all tested di or tri-peptides. Phenotypic study of µ-opioid mice fed on chow, HP diet or having undergone portal vein infusions of di or tri-peptides, confirmed that IGP could be induced by di or tri-peptides and their mechanism takes place with µ-opioïd receptors. This study suggests that all di or tri-peptide produced by protein degradation could induce IGP by a µ-opioïd receptor-dependent mechanism

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A pesquisa foi realizada com o objetivo de desenvolver uma raÃÃo para abelhas Apis mellifera usando produtos regionais do Nordeste de fÃcil acesso e baixo custo para o produtor. Os experimentos foram conduzidos entre marÃo de 2001 e janeiro de 2005 no NÃcleo de Pesquisa com Abelhas (NUPA) da Embrapa Meio-Norte com sede em Teresina (5Â05â S de latitude e 42Â49â W de longitude) e nos apiÃrios experimentais em Castelo do Piauà (5Â20â S de latitude e 41Â34â W de longitude). Levando-se em consideraÃÃo os alimentos fornecidos Ãs abelhas pelos apicultores, a facilidade dos mesmos serem colhidos, produzidos ou encontrados comercialmente na regiÃo e a preferÃncia natural das abelhas, medida por observaÃÃes empÃricas, iniciou-se o trabalho com feno das folhas de mandioca (Manihot esculenta); feno das folhas de leucena (Leucaena leococephala); farinha de vagem de algaroba (Prosopis juliflora); farinha de vagem de bordÃo-de-velho (Pithecellobium cf. saman); farelo de babaÃu (Orbygnia martiana) e sucedÃneo do leite para bezerros da marca PurinaÂ. O desempenho das abelhas alimentadas com estes componentes foi comparado com o desempenho das abelhas alimentadas com pÃlen adquirido da COORPEPÃLEN, Cooperativa de PÃlen do Brasil, localizada na cidade de Canavieiras, Bahia, havendo predominÃncia do pÃlen de Palmae. Inicialmente os componentes selecionados foram testados quanto à toxicidade e analisados quanto aos teores de proteÃna bruta, aÃÃcares livres totais, aminoÃcidos totais e teores de glicina, alanina, valina, leucina, isoleucina, fenilalanina, treonina, serina, metionina, aspargina, glutamina, aspartato, glutamato, lisina, arginina, histidina, asparagina e &#61543;-aminobutirato. Os resultados demonstram que o alto teor de aÃÃcares contido na farinha de bordÃo-de-velho nÃo permite que a mesma seja fornecida Ãs abelhas na forma in natura, uma vez que houve uma mortalidade precoce das abelhas alimentadas com esta farinha. Os demais alimentos nÃo se mostraram tÃxicos, porÃm, somente o feno da leucena contÃm os teores de aminoÃcidos essenciais requeridos pelas abelhas Apis mellifera. Com base nos dados obtidos foram formuladas as seguintes composiÃÃes de raÃÃes: (T01) - 260 g de feno de mandioca, 140 g de farinha de algaroba, 437,39 g de xarope e 0,96 g de essÃncia de baunilha; (T02) - 68 g de feno de mandioca, 332 g de farelo de babaÃu, 643,90 g de xarope e 1,32 g de essÃncia de baunilha; (T03) - 304 g de farelo babaÃu, 96 g de sucedÃneo do leite, 507,73 g de xarope e 1,08 g de essÃncia de baunilha e (T04) â 500 g de pÃlen apÃcola e 254,79 g de xarope. As raÃÃes foram testadas quanto ao consumo, desenvolvimento das colÃnias e digestibilidade. Os resultados demonstraram que apesar de nenhuma das trÃs raÃÃes ser tÃo palatÃvel e nem tÃo eficiente quanto o pÃlen na manutenÃÃo das crias, contribuÃram para que as colÃnias ao final do experimento estivessem em condiÃÃes melhores do que as iniciais, com maior Ãrea de alimento e maior peso. Os resultados do teste de digestibilidade demonstraram que os alimentos fornecidos tiveram altos Ãndices de digestbilidade, o que pode ser atribuÃdo ao alto consumo de xarope invertido e de Ãgua. Com os resultados obtidos pode-se recomendar as raÃÃes formuladas a apicultores como suplementaÃÃo alimentar para manutenÃÃo dos enxames fortes, entretanto, em situaÃÃes em que as raÃÃes passam a ser a Ãnica fonte protÃica fornecida Ãs abelhas seria necessÃria a busca de novas alternativas / The objective of this research was to develop a protein diet for honeybees Apis mellifera using regional products of NE Brazil that are of easy access and reduced costs for beekeepers. Experiments were carried out between March 2001 and January 2005 in the âNÃcleo de Pesquisa com Abelhasâ (NUPA) of the Embrapa Meio-Norte in Teresina (5Â05â S and 42Â49â W) and in Castelo do Piauà (5Â20â S and 41Â34â W), PiauÃ, Brazil. Products selected at the beginning of the research were cassava hay (Manihot esculenta), leucaena hay (Leucaena leococephala), mesquite pod meal (Prosopis juliflora), âbordÃo-de-velhoâ pod meal (Pithecellobium cf. saman), babassu bran (Orbygnia martiana) and succedaneums for calfskin from PurinaÂ. The performance of honeybees that consumed these components was compared with those that consumed pollen obtained from COORPEPÃLEN, Cooperativa de PÃlen do Brasil, located in Canavieiras, Bahia, Brazil. Pollen fed to bees was predominantly Palmae pollen. Initial components selected were tested about toxic effects for honeybees; contents of crude protein, total soluble sugars, free amino acids, and contents of glycin, alanine, valine,leucine, isoleucine, phenylalanine, tyrosine, serine, methionine, asparagines, glutamine, aspartic acid, glutamic acid, lysine, arginine, histidine, asparagines and &#61543;-aminobutyric acid. Results showed that the high content of sugars in the flour of âbordÃo-de-velhoâ does not allow its use for feeding honeybees, considering that it was observed an early mortality in the honeybees feeding with this meal. The other substances studied did not show any toxic effect, but only the leucaena hay have the contents of essential amino acids demanded by the honeybees. These results permitted the formulation of four diets: (T01) - 260 g of cassava hay, 140 g of mesquite pod meal, 437,39 g of sugar syrup and 0,96 g of vanilla essence; (T02) - 68 g of cassava hay, 332 g of babassu bran, 643,90 g of sugar syrup and 1,32 g of vanilla essence; (T03) - 304 g of babassu bran, 96 g of succedaneums for calfskin, 507,73 g of sugar syrup and 1,08 g of vanilla essence and (T04) â 500 g of pollen and 254,79 of sugar syrup. The feeds were tested for consumption, colony development and digestibility. Results showed that the three diets formulation did not show the same consumption and brood maintenance that pollen. However, by the end of the experiment all colonies were in better conditions than in the beginning, with higher food area and colony weight. The higher digestibility observed in the tests of digestibility could be attribute to the high consumption of sugar syrup and water. Results give evidence that all diets were efficient in maintaining the colonies strong and can be used by the beekeepers to maintain colony strength over the leanest period of the year. However, when the diet was the single source of protein, it was necessary to search for other alternative.

La progression de l'incidence de l'insuffisance rénale chronique dans le monde nécessite d'améliorer les mesures visant à ralentir sa progression et son évolution vers l'insuffisance rénale terminale. Le régime pauvre en protéines ou la prévention des épisodes d'ischémie- reperfusion appartiennent à ces mesures de néphroprotection mais leur bénéfice n'est qu'incomplètement compris. Le rein étant un des organes les plus vascularisé, rapporté à son poids, l'évaluation concomitante de la perfusion rénale ([15O]H2O), du métabolisme oxydatif ([11C]acetate) puis du contenu tissulaire en oxygène (BOLD-IRM) est fondamentale dans la mesure où ces trois mesures ne sont pas corrélées de manière linéaire. La TEP-IRM, appareil hybride combinant les fonctionnalités de la TEP et de l'IRM, permet une évaluation concomitante de ces trois paramètres de manière non invasive et sur rein isolé ce qui permet de l'utiliser en recherche clinique pour l'évaluation de l'effet de différentes interventions. Les régimes pauvres en protéines ont démontré qu'ils permettaient un ralentissement du déclin de la fonction rénale mais le mécanisme à l'origine de cet effet bénéfique n'est pas connu. Nous avons démontré que le contenu en AGE (Advanced Glycation End Products ou protéines modifiées) d'une charge protéique était responsable de la mobilisation de la réserve fonctionnelle rénale avec une augmentation de la perfusion et du métabolisme oxydatif plus importants après une charge protéique riche en AGE par rapport à une charge protéique pauvre en AGE. Nos résultats permettent de s'interroger sur l'intérêt d'une alimentation pauvre en AGE pour les insuffisants rénaux chroniques au-delà d'une restriction protéique pure. La prévention des épisodes d'ischémie- reperfusion est également particulièrement importante dans le cadre de la néphroprotection alors que la revascularisation d'une sténose de l'artère rénale s'accompagne obligatoirement de lésions de reperfusion. L'utilisation de la ciclosporine avant la dilatation d'une sténose de l'artère rénale dans le cadre d'un pré conditionnement a permis de réduire les lésions rénales chez la souris mais ce bénéfice clinique n'a pas été démontré chez l'homme. L'étude CICLOSAAR qui a pour but d'évaluer le bénéfice d'un pré conditionnement par la ciclosporine A avant dilatation d'une sténose de l'artère rénale sur des paramètres fonctionnels rénaux (perfusion, métabolisme oxydatif et contenu tissulaire en oxygène) est en cours. Dans un second temps et afin d'améliorer l'applicabilité clinique de ces techniques d'imagerie fonctionnelle, nous avons démontré que l'acétate, qui était jusque-là utilisé comme un marqueur de métabolisme oxydatif, pouvait également être utilisé comme un marqueur de perfusion rénale grâce à la modélisation de son uptake par le rein. Au total, la TEP- IRM est un outil fondamental pour l'évaluation des paramètres fonctionnels rénaux de manière non invasive chez l'humain. La mise en évidence de l'impact du contenu en AGE sur la perfusion et le métabolisme rénal devrait permettre d'affiner nos conseils diététiques aux insuffisants rénaux pour prévenir la progression de la maladie vers l'insuffisance rénale terminale. L'étude CicloSAAR actuellement en cours devrait permettre d'améliorer les mesures mises en oeuvre pour protéger le rein des lésions de reperfusion après dilatation d'une sténose de l'artère rénale. Enfin, nos résultats sur la forte corrélation entre les données de perfusion en acétate et en eau devraient permettre d'utiliser ce traceur pour obtenir la perfusion et le métabolisme oxydatif à l'issue d'une seule injection de radio-traceur et renforcer l'applicabilité clinique de ces techniques / The increase in the incidence of chronic renal failure worldwide requires improvements in measures to slow its progression to end-stage renal failure. The low-protein diet or the prevention of episodes of ischemia-reperfusion belong to these measures of nephroprotection but their benefit is only incompletely understood. The kidney is one of the most vascularized organs, compared to its weight, the concomitant evaluation of renal perfusion ([15O] H2O), oxidative metabolism ([11C] acetate) and tissue content in oxygen (BOLD-IRM) is fundamental in that these three measures are not linearly correlated. PETMRI, a hybrid device combining the functionalities of PET and MRI, allows a concomitant evaluation of these three parameters in a non-invasive and isolated kidney way which allows to use it in clinical research for the evaluation of the effect of different interventions. Low-protein diets have been shown to slow down the decline in renal function, but the mechanism behind this beneficial effect is not known. We have demonstrated that the AGE (Advanced Glycation End Products) content of a protein load is responsible for the mobilization of the renal functional reserve with an increase in perfusion and oxidative metabolism after a high- AGE high- protein compared to a low- AGE high- protein load. Our results make it possible to question the interest of a low-AGE diet for chronic renal insufficiency beyond a pure protein restriction. The prevention of episodes of ischemia reperfusion is also particularly important in the context of nephroprotection, whereas the revascularization of a stenosis of the renal artery is necessarily accompanied by reperfusion injury. Use of ciclosporin prior to dilation of renal artery stenosis in pre-conditioning reduced renal damage in mice, but this clinical benefit has not been demonstrated in humans. The CICLOSAAR study, which aims to evaluate the benefit of pre-conditioning with ciclosporin before dilation of renal artery stenosis with renal functional parameters (perfusion, oxidative metabolism and tissue oxygen content) is in progress. In a second step and to improve the clinical applicability of these functional imaging techniques, we have shown that acetate, which was previously used as a marker of oxidative metabolism, could also be used as a marker of renal perfusion through the modeling of its uptake by the kidney. In total, PET-MRI is a fundamental tool for the evaluation of renal functional parameters in a non-invasive way in humans. Demonstrating the impact of the AGE content of a protein load on perfusion and renal metabolism should help refine our dietary advice to patients with chronic kidney disease to prevent progression of the disease to end-stage renal failure. The current CicloSAAR study is expected to improve the measures implemented to protect the kidney from reperfusion injury after dilatation of renal artery stenosis. Finally, our results on the strong correlation between acetate and water perfusion data should allow this tracer to be used to obtain perfusion and oxidative metabolism after a single radio tracer injection and reinforce clinical applicability of these techniques