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Martin, Jessica. "Les effets interactifs du stress et de la diète sur la prise alimentaire et l'activité neuronale." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28025/28025.pdf.
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Frifra, Mehdi. "Impact des Nutriments sur les Maladies Métaboliques : caractérisation d'échantillons végétaux sur des modèles cellulaires impliqués dans l’obésité." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0084.
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L’obésité est la pathologie métabolique la plus répandue dans le monde, induisant le développement de maladies telles que la stéatose hépatique non-alcoolique et l’athérosclérose. L’approche nutritionnelle apparaît primordiale dans la prévention de ces désordres métaboliques. Des études ont démontré une relation inverse entre la consommation de végétaux et le développement de maladies métaboliques. L’objectif de cette étude est d’évaluer l’impact des conditions de culture et de conservation couplé à la variabilité génétique de deux végétaux (pommes et carottes) sur des modèles cellulaires dont la fonction est altérée lors de l’obésité (hépatocytes et adipocytes). Quatre variétés de pommes (Gala, Golden Delicious, Granny Smith et Pink Lady) ont été stockées selon quatre modes de conservation tandis que six variétés de carottes (Karotan, Bolero, Presto, Deep Purple, Kintoki et Blanche des Vosges) ont été cultivées selon quatre méthodes différentes. La stratégie de ce projet consiste en une mise en place de protocoles adéquats pour le criblage cellulaire dans différents processus métaboliques tels que l’apoptose, l’accumulation des lipides et le stress oxydant. Le criblage cellulaire a démontré une variabilité des effets des échantillons dépendant de la conservation, de la culture et de la variabilité génétique. Ces résultats ont permis de les classer en fonction de leurs effets bénéfiques. Les deux échantillons de pommes ayant le plus haut potentiel anti-apoptotique sur les cellules endothéliales ont été choisis afin de déterminer leurs mécanismes d’actions. Les résultats montrent que le mécanisme d’action de ces échantillons met en jeu la modulation du stress oxydantObesity is a metabolic disorder that is spreading worldwide. Obesity can lead to many diseases such as non-alcoholic fatty liver disease or atherosclerosis. Nutritional approach appears to be an essential strategy for the prevention of metabolic disorders. Indeed, some studies show the correlation between vegetables’ consumption and decrease of cardiovascular diseases.The aim of the study is to evaluate the impact of harvests and storages’ conditions coupled with genetic variability of two vegetables (apples and carrots) on cellular models in which their function is altered during obesity (hepatocytes and adipocytes). Four varieties of apple (Gala, Golden Delicious, Granny Smith and Pink Lady) have been used depending on four different types of storage whereas six varieties of carrots (Karotan, Bolero, Presto, Deep Purple, Kintoki and Blanche des Vosges) have been harvested in four different ways.The strategy of this project is to put some proper protocols for cellular screening in different metabolic processes such as apoptosis, adipocyte differentiation, lipid accumulation, and oxidative stress. Cellulars creening showed variabilities on samples effects depending on storage and harvest conditions, and genetic variabilities. These results allowed us to classify samples according to their most interesting beneficial effects. Then, we chose apple samples with the highest anti-apoptotic effects on endothelial cells in order to investigate their mechanisms of action. The results show that the ability of apple samples to reduce apoptosis is associated with the modulation of oxidative stress
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Walter, Allison. "Propriétés anti-angiogéniques des polyphénols du vin rouge in vivo : rôle potentiel dans la prévention de l'athérosclérose et des cancers." Strasbourg, 2009. http://www.theses.fr/2009STRA6268.
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En 2005 l’Organisation Mondiale de la Santé (OMS) décomptait 58 millions de décès dans le monde dont 30% étaient dus aux maladies cardiovasculaires et 13% aux cancers, pathologies dont le développement est en partie contrôlé par la néo-angiogenèse. Des études épidémiologiques ont montré qu’une consommation régulière de fruits et de légumes et de vin rouge, en quantité modérée, est associée à une réduction du risque d’apparition de maladies cardiovasculaires et de cancers. Cet effet protecteur a été attribué en partie aux composés polyphénoliques. L’objectif principal de ce travail est d’évaluer le potentiel anti-angiogénique des polyphénols du vin rouge in vivo et de déterminer si ces propriétés contribuent à retarder la croissance tumorale et le développement de pathologies cardiovasculaires. Une première étude a permis de montrer que l’absorption de polyphénols du vin rouge prévient le stress oxydant ainsi que l’expression des ces facteurs pro-angiogéniques induits par l’angiotensine II in vivo. Une seconde étude a démontré que l’effet pro-angiogénique de l’angiotensine II est associé à la formation de néo-vaisseaux et à l’expression de facteurs pro-angiogéniques et que l’effet anti-angiogénique des polyphénols de vin rouge est associé à la prévention de cette néoangiogenèse induite par l’angiotensine ainsi qu’à une prévention de l’expression des facteurs pro-angiogéniques. Un modèle de tumeurs colorectales sous-cutanées a permis de démontrer que l’absorption de polyphénols in vivo permet de prévenir la croissance tumorale associée à une réduction de l’angiogenèse, de l’expression de facteurs pro-angiogénqiues tout en induisant l’expression de gènes suppresseurs de tumeursIn 2005 the World Health Organization (WHO) mentioned 58 millions of death among them 30% are attributated to cadiovascular disease and 13% to cancers, pathologies associated to angiogenesis. Epidemiological studies demonstrated that a regular intake of fruits, vegetables and red wine is associated to a reduced risk of ardiovascular diseases and cancers. This protective effect has been attributed to polyphenolic compounds. The major goal of this study is to evaluate the in vivo anti-angiogenic potential of red wine polyphenols and to determine if these properties participate the prevention of cardiovascular diseases and tumoral development. A first study demonstrated that in vivo intake of red wine polyphenols prevent oxidative stress and pro-angiogenic factors induced by angiotensin II. A second one, demonstrated that the pro-angiogenic effect of angiotensine II is associated to the development of new blood vessels and to pro-angiogenic factors. Red wine polyphenols intake prevent new blood vessels formation as weel as pro-angiogenic factors expression. A sub-cutanous colorectal cancer model, let us to show that red wine polyhenols intake in vivo, reduces tumor development, neo-angiogenesis, tumor pro-angiogenic factors and induces apoptosis
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Dragin, Nadine Aude. "Implication des facteurs nutritionnels et du stress oxydant dans la régulation de l'expression génique au cours du vieillissement chez la souris." Bordeaux 2, 2003. http://www.theses.fr/2003BOR21041.
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Le stress oxydant (SO) est impliqué dans le processus du vieillissement. Pour comprendre le rôle des facteurs nutritionnels sur le SO, nous étudions l'effet d'une alimentation standard, restrictive (RC), cafeteria (CD) et d'un SO chronique par le paraquat (PQ) sur des souris mâles C57BL6J au cours du vieillissement. Le statut antioxydant (SOD, GPX, Catalase et vitamines E, A) est estimé dans le sang, le foie et le cerveau. L'expression génique est suivie par cDNA array. Les performances cognitives sont évaluées par des tests comportementaux de mémoire. PQ et CD accélèrent la diminution liée à l'âge du SA et favorisent l'expression de gènes impliqués dans la prolifération et la différenciation cellulaire dans les différents tissus. Par contre, RC réprime la décroissance du SA et stimule l'expression des gènes de réparation et de renouvellement cellulaire. La diminution liée à l'âge des capacités d'apprentissage est augmentée par CD et PQ mais réprimée par RC comparé au témoin. Ces résultats montrent que l'interrelation entre le SO, le vieillissement tissulaire et cognitif qui peut être modulé par des facteurs nutritionnelsThere is some evidence that diet and oxidative stress can modulate the ageing process. To assess the role of nutritional factors on oxidative stress in liver and brain during ageing, we separated mice C57BL6j male in 4 groups : a standard, restriction (RD) and cafeteria (CD) diets, a chronic oxidative stress by Paraquat (PQ). Blood, liver and brain antioxidant status (AS) was determined by vitamins A, E, superoxyde dismutase, gluthation peroxydase and catalase analysis. Gene expression was studied by using cDNA arrays. Cognitive performances were evaluated using behavioral tests. PQ and CD enhanced the effect of ageing on AS and learning capacity compared to controls. They activate expression of gene implicated in proliferation and differentiation in tissues. On contrary, RC decrease ageing effect on AS and acquisition capacity and increase expression of gene implicated in reparation and cell survival. These results suggested a relationship between OS, ageing tissue, cognitive performances that could be modified by nutritional factors
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Ruel, Guillaume. "Effets de la canneberge (Vaccinium Macrocarpon) sur le profil cardiométabolique chez l'homme: Lipides, stress oxydatif, inflammation et fonction endothéliale." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27454/27454.pdf.
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Le, Goffe Claire. "Contrôle métabolique de la réponse des cellules épithéliales au stress oxydatif : une nouvelle approche par manipulation de la source hydrocarbonée des cellules en culture." Paris 7, 2003. http://www.theses.fr/2003PA077065.
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Corbel, Hélène. "Envol chez le poussin d'oiseau : Rôle de l'investissement parental et mécanismes proximaux." Strasbourg 1, 2008. http://www.theses.fr/2008STR13220.
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L’envol du jeune oiseau est une transition vers l’autonomie locomotrice et alimentaire. L’état physique doit alors être optimisé pour limiter les risques accrus de mortalité par prédation ou par famine. Cet état est largement dépendant de l’investissement parental lequel fait l’objet d’un conflit entre parents et petits. Mon travail de thèse s’attache à comprendre les mécanismes proximaux retenus chez l’oiseau pour optimiser le phénotype à l’envol. Deux espèces à l’écologie contrastée ont été comparées: le Manchot royal (MR; Aptenodytes patagonicus) et la Cigogne blanche (CB; Ciconia ciconia). Chez le MR, l’accumulation de réserves lipidiques dans la progéniture permet à l’éleveur de déserter et d’initier la mue prénuptiale tout en assurant la fin de la croissance du poussin à jeun. De plus, ces réserves préviennent une activation de l’axe hypothalamo-hypophyso-corticosurrénalien (HHCS) et un catabolisme exacerbé des protéines, lequel menacerait l’intégrité musculaire du poussin. Chez la CB, la restriction alimentaire parentale induit chez les cigogneaux un stress nutritionnel qui active l’axe HHCS et la sécrétion de corticostérone. La corticostéronémie élevée stimulerait les exercices locomoteurs au nid et par là faciliterait l’envol. La hiérarchie de développement au sein de la nichée modulerait la sensibilité de l’axe HHCS, ce qui préviendrait les effets délétères d’une corticostéronémie chroniquement élevée sur la croissance alaire des derniers éclos. Mes résultats permettent de proposer de nouvelles hypothèses quant aux pressions sélectives exercées sur 1) l’accumulation des réserves lipidiques et 2) la sécrétion de corticostérone chez le poussin en fin de croissanceFledging in birds is a transition from a situation in which it is totally dependent on its parents to a self-sufficient life. Physical state should be optimized at fledging to face increased predation and starvation risks outside the nest. Physical state at fledging is largely dependent on parental investment, over which parents and offspring disagree. My Ph. D work aims at understanding the proximate mechanisms that optimize phenotype at fledging. I used a comparison between two avian species with markedly different ecology: the King penguin (KP, Aptenodytes patagonicus) and the White stork (WS; Ciconia ciconia). In KP, parents accumulate important lipid stores in chicks before deserting and starting prenuptial moult. Lipid stores in deserted, fasting chicks fuel the completion of growth. Lipid stores also prevent the activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis and associated increased catabolism of muscular proteins in chicks. In WS, parental food restriction results in a nutritional stress which activates the HPA axis and corticosterone release in chicks. High plasma levels of corticosterone stimulate flight-training activity and hence facilitate fledging. The down-regulation of the HPA axis in last-hatched chicks prevents the impairment of wing growth due to chronically elevated plasma levels of corticosterone. The results of my work are discussed and shed new light on the evolutionary forces that shape 1) fattening and 2) corticosterone release in prefledging birds
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Gagné, Amélie. "Étude des concentrations d'antioxydants plasmatiques après supplémentation en vitamines E et C au cours de la grossesse." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/25990/25990.pdf.
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La prééclampsie (PE) est caractérisée par de l’hypertension et de la protéinurie maternelle survenant durant la grossesse. Certaines études ont suggéré que la supplémentation en vitamines (E et C) pourrait diminuer l’incidence de PE. Des échantillons sanguins de femmes avec (n=15) ou sans (n=100) PE, participant à l’étude International Trial of Antioxidants for the Prevention of PE (INTAPP), ont été collectés avant la prise de vitamines, ainsi qu’aux semaines 24 et 32 de la grossesse. Les niveaux de vitames ont été mesurés par HPLC. L’augmentation significative des niveaux d’α-tocophérol et de coenzyme Q10 au cours de la grossesse chez les femmes non supplémentées, avec ou sans PE, pourrait représenter une réponse naturelle effective contre le stress oxydatif. Le ratio abaissé de γ-/α-tocophérol, observé pour la première fois chez des femmes enceintes supplémentées, suggère une augmentation d’α-tocophérol et/ou une diminution de γ-tocophérol causée par une compétition pour l’absorption intestinale des tocophérols.Preeclampsia (PE) is a syndrome characterized by hypertension and maternal proteinuria during pregnancy. Some studies have suggested that supplementation with vitamins (E and C) could decrease the incidence of PE. Women (n=100) from the International Trial of Antioxidants for the Prevention of PE study were collected at week 12-16 of gestation (prior to vitamins supplementation), then at weeks 24 and 32 of gestation. A second group of 15 preeclamptic women was also selected for this study. Vitamins were determined using high-performance liquid chromatography. The higher α-tocopherol and coenzyme Q10 concentrations during pregnancy in non-supplemented women, with or without PE, could represent a naturally response against oxidative stress in pregnant women. The lower ratio of γ-/α-tocopherol, observed for the first time in supplemented pregnant women, suggest an increase in plasma α-tocopherol due to dietary supplementation and/or a decrease in γ-tocopherol resulting from a competition for the intestinal absorption of tocopherols.
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Corblin, Fabien. "Conception et mise en oeuvre d'un outil déclaratif pour l'analyse des réseaux génétiques discrets." Phd thesis, Grenoble 1, 2008. https://theses.hal.science/tel-00388776.
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Une demande croissante d'outils pour construire et décrypter des réseaux génétiques contrôlant des processus cellulaires est ressentie en biologie. Nous soutenons que l'utilisation de l'approche déclarative est pertinente et applicable pour répondre aux questions des biologistes sur ces réseaux, en général partiellement connus. L'idée principale est de modéliser des connaissances portant à la fois sur la structure et la dynamique d'un réseau par un ensemble de contraintes représentant l'ensemble des solutions, de vérifier sa cohérence, de réparer une incohérence éventuelle par un relâchement automatique, et d'inférer des propriétés sur la structure et la dynamique du réseau. Pour montrer la faisabilité de l'approche, nous formalisons les réseaux discrets de R. Thomas et les propriétés biologiques pertinentes, proposons un outil reposant sur la programmation logique par contraintes en coopération avec un solveur SAT, et la validons sur des applications biologiques significativesA growing demand for tools to build and decrypt genetic networks that control cellular processes is felt in biology. We argue that the use of the declarative approach is relevant and applicable to answer questions from biologists about these networks, which are in general partially known. The main idea is to model knowledge about both the structure and the dynamic of a network by a set of constraints representing all the solutions, to check its consistency, to repair a possible inconsistency by an automatic constraint removal, and to infer properties on the structure and dynamic of the network. To demonstrate the feasibility of the approach, we formalize the discrete networks of R. Thomas and relevant biological properties, offer a tool based on constraint logic programming in cooperation with a SAT solver, and validate it on significant biological applications
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Bourgoin, Frédéric. "La contribution du stress oxydatif et de médiateurs inflammatoires dans les complications vasculaires, métaboliques et moléculaires induites chez le rat soumis à une alimentation riche en gras et en sucre, un modèle de résistance à l'insuline." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29180/29180.pdf.
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L’obésité viscérale est identifiée comme étant le facteur de risque de maladies cardiovasculaires le plus contributif à la résistance à l’insuline. De mauvaises habitudes alimentaires et la sédentarité contribueraient à l’obésité et affecteraient de manière indépendante et défavorable les actions métaboliques et vasculaires de l’insuline. L’objectif visé par ce projet de recherche consistait à déterminer l’impact d’une alimentation riche en gras saturé et en sucre (HFHS) sur la fonction endothéliale ainsi que l’établissement d’un stress oxydatif et d’une réponse inflammatoire dans un modèle animal de résistance à l’insuline avec surplus de poids. Plus précisément, le chapitre 2 avait pour but de développer et de caractériser un nouveau modèle expérimental animal, le rat nourri avec un régime HFHS, plus représentatif de la diète consommée par un pourcentage élevé de la population nord-américaine. Le chapitre 3 avait pour objectif de déterminer les effets d’un traitement préventif avec un antioxydant, le tempol, sur la fonction endothéliale ainsi que les actions glucorégulatrices et hémodynamiques de l’insuline dans ce modèle animal. Le chapitre 4 avait pour but d’étudier les effets du régime HFHS et du tempol sur l’expression et l’activité de marqueurs des voies de signalisation de l’insuline ainsi que de biomarqueurs du stress oxydatif et de l’inflammation. Nous avons noté que le régime HFHS entraînait une altération de la vasodilatation endothélium-dépendante, une diminution du transport du glucose stimulé par l’insuline et de la sensibilité à l’insuline ainsi qu’une réduction de l’expression et de l’activation de plusieurs protéines de la voie de signalisation à l’insuline. Nous avons également identifié des facteurs du stress oxydatif ou inflammatoires susceptibles de contribuer à la dégradation de la fonction endothéliale et prendre part aux complications vasculaires et métaboliques induites par le régime HFHS chez le rat. Nous démontrons que plusieurs de ces altérations pouvaient être évitées, atténuées ou retardées par une intervention précoce destinée à contrôler le stress oxydatif. Ce projet de recherche a permis de mieux comprendre l’implication et le lien entre le NO endothélial et le stress oxydatif ainsi que l’inflammation induits par un régime HFHS, dans un modèle animal de résistance à l’insuline avec surplus de poids.Visceral obesity has been identified as the main cardiovascular disease risk factor that contributes to insulin resistance. Bad eating habits and sedentary lifestyle can contribute to obesity, but can also affect independently and unfavourably the metabolic and vascular insulin actions. The aim of this research project was to determine the impact of a high fat high sucrose diet (HFHS) on endothelial function as well as the establishment of an oxidative stress and inflammatory response in an animal model of dietary-acquired insulin resistance and obesity. Precisely, the objective of chapter 2 was to develop a new animal experimental model, the rat fed with a diet rich in saturated fat and refined sugar, representative of the high-energy diets frequently consumed by a large percentage of North American. The aim of chapter 3 was to determine the effects of a preventive treatment with an antioxidant, tempol, on endothelial function as well as glucoregulatory and hemodynamic actions of insulin in this animal model. The objective of chapter 4 was to study the effects of HFHS diet and tempol on the expression and activity of markers of insulin signalling pathways, oxidative stress and inflammation. We noted that the HFHS diet altered the endothelium-dependent vasodilation, decreased insulin-stimulated glucose transport and insulin sensitivity as well as reduced expression and activation of many insulin signalling pathway proteins. We also identified oxidative stress or inflammatory markers that could contribute to endothelial function degradation and take part in vascular and metabolic complications induced by the HFHS diet, in the rat. We demonstrated that many of those alterations could be avoided, attenuated or prevented by an early intervention aimed at controlling oxidative stress. This research project provided a better understanding of the implication and the link between endothelial NO and the oxidative stress as well as the inflammation induced by a HFHS diet, in an animal model of diet-induced insulin resistance and obesity.
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Engler, Paul. "Utilisation d’extraits de raisin à faible dose en alimentation animale : quantification et identification des métabolites d’intérêts, évaluation des bénéfices nutritionnels sur modèles in vitro et in vivo." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0095.
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Le stress oxydatif en élevage intensif est susceptible d’induire des effets délétères sur les performances et l’état sanitaire des animaux, ainsi que sur la qualité de leurs produits dérivés. Parmi les solutions antioxydantes développées pour lutter contre ce phénomène, figurent les additifs alimentaires riches en métabolites secondaires de plantes.L’objectif de ce travail de thèse a été de déterminer l’impact d’une supplémentation d’une faible dose d’extrait de raisin sur les performances et le métabolome d’animaux élevés en système intensif.Un premier travail a été réalisé sur la mise au point d’une méthode de dosage de l’additif à très faible dose (5μg/g) dans l’aliment complet, de manière à assurer la traçabilité du produit et a résulté en un dépôt de brevet.De plus, un essai de supplémentation de truites arc-en-ciel génitrices à l’aide de l’extrait de raisin à faible dose (60ppm) a montré une modulation du métabolome des œufs des poissons, ainsi qu’un effet significativement positif sur la croissance des alevins descendant des truites supplémentées (+5,2% à 8 semaines). Enfin, l’impact d’une modulation du profil de l’additif en composés phénoliques, supplémenté à faible dose (30ppm) sur le modèle poule pondeuse, soumis à un stress alimentaire a été étudié. Les résultats ont mis en avant des divergences d’impact des 3 extraits évalués sur les paramètres zootechniques, biologique et métabolomiques.Ce travail de thèse a permis de recueillir des éléments nécessaires à l’enregistrement de l’extrait de raisin étudié en temps qu’additif zootechnique permettant de lutter contre le stress oxydatif, au sein de l’Union EuropéenneOxidative stress in intensive livestock farming can induce severe deleterious effects on animal health and performances, as well as their derived products. Among the antioxidant solutions developed to fight against this phenomenon, are feed additives, rich in plant secondary metabolites.The aim of this work was to elucidate the impact of a dietary supplementation consisting in a small dose of grape extract on the performances and metabolome of animals, raised in intensive conditions.The creation of a method of analysis of very small doses of the additive (5μg/g) in the complete feed constituted a first axis, in order to insure traceability of the product and resulted in a patent.Moreover, a trial consisting in the supplementation of rainbow trout with a small dose of the grape extract (60ppm) evidenced a modulation of the eggs’ metabolome and a significant improvement of the offspring’s growth (+5.2% weight at 8 weeks).Finally, the impact of the modulation of the phenolic profile of the additive, used in small dose in the complete feed (30ppm) of laying hens exposed to a dietary stress was studied. Results evidenced variations of the impact of the 3 grape extracts tested on zootechnical, biological and metabolomic parameters.This research allowed to collect necessary data for the registration of the studied grape extract as a zootechnical feed additive, within the European Union, to fight against oxidative stress
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Malardé, Ludivine. "Activité physique et produits dérivés du soja : intérêts dans la prise en charge du stress oxydant associé au diabète de type 1." Phd thesis, Université Rennes 2, 2012. http://tel.archives-ouvertes.fr/tel-00775870.
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Le Stress Oxydant (SO) est bien connu pour être impliqué dans la survenue et le développement des complications du diabète. Il est causé, au moins en partie, par une élévation importante de la glycémie. Chez les sujets diabétiques, lathérapie par l'insuline est vitale et constitue la pierre angulaire de la thérapie. Mais elle ne permet pas d'éviter à long terme l'apparition de complications, résultant du SO induit par les épisodes hyperglycémiques persistants.Chez le sujet sain, des prises en charge nutritionnelles et/ou par l'activité physique ont démontré avec succès leur capacité à diminuer le SO. L'activité physique bien conduite présente de plus l'avantage d'exercer un effet glucorégulateur.L'objectif de ces travaux de thèse était donc de déterminer si l'association de différentes prises en charge pouvait permettre de mieux lutter contre le SO, en agissant par des mécanismes complémentaires, démontrant alors des effetsadditifs. En s'appuyant sur différents protocoles de supplémentation, de traitement à l'insuline et/ou d'entraînement en endurance, nos travaux ont mis en évidence démontré l'intérêt d'un composé alimentaire dérivé du soja, le PFS, dansla prise en charge du SO associé audiabète. Nos travaux ont également mis en évidence que l'insuline et l'entraînement en endurance améliorait le SO induit par l'hyperglycémie, via des mécanismes partiellement différents. Leur association dans la prise en charge du diabète leur permet de potentialiser mutuellement leurs effets respectifs
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Corblin, Fabien. "Conception et mise en oeuvre d'un outil déclaratif pour l'analyse des réseaux génétiques discrets." Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00388776.
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Une demande croissante d'outils pour construire et décrypter des réseaux génétiques contrôlant des processus cellulaires est ressentie en biologie. Nous soutenons que l'utilisation de l'approche déclarative est pertinente et applicable pour répondre aux questions des biologistes sur ces réseaux, en général partiellement connus. L'idée principale est de modéliser des connaissances portant à la fois sur la structure et la dynamique d'un réseau par un ensemble de contraintes représentant l'ensemble des solutions, de vérifier sa cohérence, de réparer une incohérence éventuelle par un relâchement automatique, et d'inférer des propriétés sur la structure et la dynamique du réseau. Pour montrer la faisabilité de l'approche, nous formalisons les réseaux discrets de R. Thomas et les propriétés biologiques pertinentes, proposons un outil reposant sur la programmation logique par contraintes en coopération avec un solveur SAT, et la validons sur des applications biologiques significatives.
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Chaudhry, Abdul Shakoor. "Nutritional improvements of cereal straws." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279301.
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Mehaba, Nabil. "Heat stress effects and nutritional alleviation strategies in small ruminants." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670657.
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En esta tesis, se estudiaron los efectos del estrés por calor (EC) sobre la producción de ovejas lecheras Lacaune (Exp.1), así como la respuesta de cabras lecheras Murciano-Granadina bajo condiciones de EC a la L-carnitina (Exp. 2) y la metionina (Exp. 3). En los 3 Exp., los animales fueron alimentados con una ración única mezclada y se ordeñaron x2 al día. Las condiciones ambientales fueron: termo-neutralidad (TN; THI = 59-65) y EC (día, THI = 83; noche, THI = 75). El fotoperíodo (día-noche) fue constante (12-12 h). La temperatura rectal (TR), el ritmo respiratorio (RR), la IMS, el consumo de agua (CA) y la producción de leche (PL) se registraron diariamente, mientras que la leche para la composición se muestreó semanalmente y se registró el peso vivo (PV) al inicio y al final de cada período. En el Exp.1, las ovejas (n = 8) fueron expuestas a TN o EC en un diseño cruzado de 2 períodos (21 días cada uno). Además, a las ovejas se les administró glucosa, insulina y epinefrina para evaluar sus respuestas metabólicas. EC aumentó la TR, RR, CA y la pérdida de PV, pero redujo la IMS y el contenido de grasa y proteína de la leche sin afectar a PL. A pesar de la reducción de IMS por EC, los AGNE en sangre no cambiaron, y sin embargo los valores de creatinina aumentaron. La respuesta a los desafíos metabólicos indicó que las ovejas EC presentaban una rápida absorción de glucosa y una mayor resistencia a las señales lipolíticas en comparación con las ovejas TN. En los Exp.2 y 3 con cabras lecheras, el diseño fue un cuadrado latino 4 × 4, ya que se agregaron 2 factores dietéticos a las 2 condiciones ambientales. Las 2 condiciones dietéticas fueron control (CON) sin suplementación, versus L-carnitina protegida del rumen (CAR, Exp. 2) o metionina protegida del rumen (Met, Exp. 3). En Exp. 2, las cabras EC experimentaron un aumento de TR y RR. Además, las cabras EC sufrieron una pérdida del 26% en IMS, pero tendieron a comer partículas de tamaño más largo. La CAR aumentó drásticamente las concentraciones de carnitina libre, acetilo y total en sangre. A pesar de esta absorción eficiente, CAR no tuvo efecto sobre IMS, producción de leche o metabolitos en sangre en condiciones TN o EC. En el Exp.3, la IMS de las cabras TN se limitó a 2.0 kg/d, mientras que las cabras de EC se alimentaron ad libitum. Así pues, las cabras EC presentaron sólo un 9.8% menos IMS que TN, aunque significativo. En consecuencia, no se detectaron cambios en PL. Se observaron incrementos esperables en TR y RR debido al EC, pero Met redujo el RR por la mañana y RT en la tarde. Además, Met evitó la pérdida típica de PV en condiciones de EC. El perfil de aminoácidos en sangre (AA) reveló una menor concentración basal de Met, a pesar de los niveles comparables de IMS. Además, las cabras EC tenían poco glutamato, lo que podría estar relacionado con una inflamación y respuesta inmune a nivel gastrointestinal. La suplementación con Met ahorró glutamato, independientemente de la temperatura ambiente. En general, el EC afectó negativamente la producción de las ovejas lecheras. La adaptación metabólica de las ovejas lecheras al EC incluyó una reducción de la movilización de grasa corporal y el aumento de la degradación de las proteínas musculares. La metionina, pero no la L-carnitina, tuvo algunos efectos beneficiosos sobre el rendimiento de las cabras lecheras estresadas por el calor. Probablemente un poco más AA además de la metionina deberían ser suplementados en condiciones de EC.In the current thesis the effects of heat stress (HS) on performance of Lacaune dairy ewes (Exp.1) as well as the response of HS Murciano-Granadina dairy goats to dietary L-carnitine (Exp. 2) and methionine (Exp. 3) were evaluated. In the 3 Exp., animals were fed a total mixed ration and milked x2 daily. The environmental conditions were: thermal neutral (TN; THI = 59-65) and HS (day, THI = 83; night, THI = 75). Photoperiod (light- dark) was constant (12-12 h). Rectal temperature (RT), respiratory rate (RR), DMI, water intake (WI) and milk yield (MY) were recorded daily, whereas milk for composition was sampled weekly and BW was registered at the start and the end of each period. In Exp.1, ewes (n = 8) were exposed to TN or HS in a crossover design with 2 periods (21 d each). Further, ewes were administered with glucose, insulin and epinephrine to evaluate the metabolic responses. HS increased RT, RR, WI and BW loss, but reduced DMI, and milk fat and protein contents without affecting MY. Despite the reduced DMI by HS, blood NEFA did not change, but creatinine values increased. Response to the metabolic challenges indicated that HS ewes had faster uptake of glucose and greater resistance to lipolytic signals compared to TN ewes. In Exp.2 & 3 with dairy goats, the design was 4 × 4 Latin square as 2 dietary factors were added to the 2 environmental conditions. The 2 dietary conditions were control (CON) without supplementation vs. rumen protected L-carnitine (CAR, Exp. 2) or rumen protected methionine (Met, Exp. 3). In Exp. 2, HS goats experienced increased RT and RR. Additionally, HS goats suffered 26% loss in DMI, but they tended to eat longer particle sizes. CAR dramatically increased blood free-, acetyl, and total-carnitine concentrations. Despite this efficient absorption, CAR had no effect on DMI, milk production or blood metabolites in TN or HS conditions. In Exp.3, DMI for TN goats was limited to 2.0 kg/d, whereas HS goats were kept feeding ad libitum. Consequently, HS goats had only 9.8% (although significant) less DMI than TN. Consequently, no changes in MY were detected. Expected increments in RT and RR due to HS were detected but Met resulted in less RR in the morning and lower RT in the afternoon. In addition, Met avoided the typical BW loss under HS conditions. The profile of blood amino acids (AA) revealed less basal Met concentration, despite the comparable DMI levels. Additionally, HS goats were in shortage of glutamate, which could be related to the inflammation and immune response at the gastrointestinal level. Met supplementation spared glutamate regardless the ambient temperature. Overall, HS negatively affected the performance of dairy ewes. Metabolic adaptations of dairy ewes to HS included reduced body fat mobilization and increased muscle protein breakdown. Methionine, but not L-carnitine, had some beneficial effects on the performance of heat-stressed dairy goats. Probably some more AA in addition to methionine should be supplemented under HS conditions.
Cette thèse, étude les effets du stress thermique (ST) sur les performances des brebis laitières Lacaune (Exp.1) ainsi que la réponse des chèvres laitières Murciano-Granadina à la L-carnitine (Exp.2) et à la méthionine (Exp. 3) sous conditions de ST. Dans les 3 Exp, les animaux ont reçu une ration totale mélangée et traitent x2 par jours. Les conditions environnementales étaient : thermoneutralité (TN; THI = 59-65) et ST (jour, THI = 83; nuit, THI = 75). La photopériode (jour-nuit) était constante (12-12 h). La température rectale (TR), le rythme respiratoire (RR), la MSI, la prise d’eau (PE) et la production de lait (PL) ont été enregistrés quotidiennement, tandis que le lait pour la composition a été échantillonné chaque semaine et PV a été enregistré au début et à la fin de chaque période. Dans Exp.1, les brebis (n = 8) ont été exposées au TN ou au ST avec permutation de 2 périodes (21 j chacune). En plus, les brebis ont été administrées avec du glucose, de l’insuline et de l’épinéphrine pour évaluer la réponse métabolique. Le ST a augmenté le TR, RR, PE et a réduit le PV, mais a réduit l’IMS et le contenu en matières grasses et en protéines du lait sans affecter la PL. Malgré la réduction de l’IMS par le ST, le AGNE sanguin n’a pas changé, mais les valeurs de créatinine ont augmenté. La réponse aux défis métaboliques a indiqué que les brebis ST avaient une absorption plus rapide du glucose et une plus grande résistance aux signaux lipolytiques que les brebis TN. Dans Exp.2 & 3 avec des chèvres laitières, le design expérimental était un carré latin 4 × 4 car 2 facteurs alimentaires ont été ajoutés aux 2 conditions environnementales. Les 2 conditions alimentaires étaient control (CON) sans supplémentation et une supplémentation avec la L-carnitine protégée du rumen (CAR, Exp. 2) ou avec la méthionine protégée du rumen (Met, Exp. 3). Dans Exp. 2, les chèvres ST ont demontré une augmentation du TR et RR accrues. De plus, les chèvres ST ont réduit de 26% l’IMS, mais elles avaient tendance à manger des particules plus longues. La CAR a considérablement augmenté les concentrations libres, d’acétyle et carnitine totale de sang. Malgré cette absorption efficace, la CAR n’a eu aucun effet sur l’IMS, la PL ou les métabolites sanguins dans les conditions TN ou ST. Dans Exp.3, l’IMS pour les chèvres TN était limité à 2,0 kg/j, tandis que les chèvres ST étaient nourries ad libitum. Par conséquent, les chèvres ST avaient seulement 9,8% (bien que significatif) de moins d’IMS que TN. Par conséquent, aucun changement dans PL n’a été détecté. Des augmentations attendues de la TR et du RR dues au ST ont été détectées, mais la Met a entraîné une diminution du RR le matin et une TR plus basse l’après-midi. De plus, Met a évité la perte de PV typique dans les conditions ST. Le profil des acides aminés du sang (AA) a révélé une concentration en Met basale inférieure, malgré des niveaux de DMI comparables. De plus, les chèvres ST manquaient de glutamate, ce qui pourrait être lié à l’inflammation et à la réponse immunitaire au niveau gastro-intestinal. La supplémentation rencontrée a épargné le glutamate quelle que soit la température ambiante. Globalement, le ST a affecté négativement la performance des brebis laitières. Les adaptations métaboliques des brebis laitières au ST comprenaient une mobilisation réduite des graisses corporelles et une dégradation accrue des protéines musculaires. La méthionine, mais pas la L-carnitine, a eu certains effets bénéfiques sur les performances des chèvres laitières soumises à un ST. Probablement un peu plus d’AA en plus de la méthionine devrait être supplémenté dans les conditions ST.
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Koyama(Ito), Ayana. "Analysis of Nutritional Components of Spinach Under Root Chilling Stress." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/264639.
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Kurz, Michael Wayne. "Nutritional modulation of immunity and physiological responses in beef calves." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/1096.
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Twenty-four crossbred steer calves (235 + 6 kg initial BW) were weaned, adapted to a growing diet, trained to use Calan feeders and assigned to one of four treatments in a 2 x 2 factorial arrangement as follows: (1) no transit stress and saline injection, (2) no transit stress and trace mineral and vitamin E (TM/VitE) injections, (3) transit stress and saline injection and (4) transit stress and TM/VitE injection. TM/VitE injections consisted of MultiminTM to provide 0.3, 0.6, 0.15 and 0.6 mg of Cu, Mn, Se, and Zn/kg BW, respectively, and Vita ETM to provide 9 IU of VitE/kg BW on d 0 and 21 of the study. On d 24, transit-stressed steers were subjected to a three-d, 2000-km, transportation period. During the 56-d experiment, liver and serum samples were assayed to assess trace mineral status, antibody titers to keyhole limpet hemocyanin (KLH) measured to assess humoral immunity and phytohemagglutinin(PHA)- and ovalbumin(OVA)-induced skin swelling and lymphocyte proliferation measured to assess cellular immunity. TM/VitE-injected steers grew slower (P < 0.05) over the first 24 d of the experiment and tended (P = 0.10) to grow slower after transit. TM/VitE injections increased (P < 0.05) liver Cu and Zn concentrations 135 and 21 % by d 30, respectively. TM/VitE-injected steers had increased (P < 0.05) serum Cu on d 24 and 26, but decreased (P < 0.05) serum Zn and whole blood Se compared to saline-injected steers on d 24 and 56. TM/VitE injections increased serum α-tocopherol concentrations. TM/VitE injections did not affect humoral immunity, but decreased (P < 0.05) skin-swelling responses to PHA on d 21, and decreased (P < 0.05) lymphocyte proliferation to OVA and KLH. Transit-stressed steers had higher (P < 0.05) serum Cu on d 26, and higher (P < 0.05) liver Cu concentrations on d 56 than non-transit-stressed steers. Transit stress did not affect serum Zn or whole blood Se concentrations. Injections of TM/VitE increased Cu, Zn and vitamin E, but not Se status. The TM/VitE treatment suppressed growth and cellular immune function suggesting that levels of trace minerals used in this study were too high.
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Walter, B. S., S. N. DeWitte, T. Dupras, and Julia Beaumont. "Assessment of nutritional stress in famine burials using stable isotope analysis." Wiley, 2020. http://hdl.handle.net/10454/17776.
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YesObjectives: We compared δ15N and δ13C values from bone and dentine collagen profiles of individuals interred in famine‐related and attritional burials to evaluate whether individuals in medieval London who experienced nutritional stress exhibit enriched nitrogen in bone and tooth tissue. Dentine profiles were evaluated to identify patterns that may be indicative of famine during childhood and were compared with the age of enamel hypoplasia (EH) formation to assess whether isotopic patterns of undernutrition coincide with the timing of physiological stress. Materials and Methods: δ15N and δ13C isotope ratios of bone collagen were obtained from individuals (n = 128) interred in attritional and famine burials from a medieval London cemetery (c. 1120–1539). Temporal sequences of δ15N and δ13C isotope profiles for incrementally forming dentine collagen were obtained from a subset of these individuals (n = 21). Results: Results indicate that individuals from attritional graves exhibit significantly higher δ15N values but no significant differences were found between burial types for the sexes. Analyses of dentine profiles reveal that a lower proportion of famine burials exhibit stable dentine profiles and that several exhibit a pattern of opposing covariance between δ15N and δ13C. EH were also observed to have formed during or after the opposing covariance pattern for some individuals. Conclusions: The results of this study may reflect differences in diet between burial types rather than nutritional stress. Though nutritional stress could not be definitively identified using bone and dentine collagen, the results from dentine analysis support previous observations of biochemical patterns associated with nutritional stress during childhood.
Division of Behavioral and Cognitive Sciences. Grant Numbers: BCS‐1261682, BCS‐1540208. Office of the Vice President for Research, University of South Carolina. Grant Number: SPARC Fellowship Grant
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Leduc, Christine. "Polyamines, stress oxydatif et progression tumorale. Essai pré-clinique de thérapie nutritionnelle." Rennes 1, 2003. http://www.theses.fr/2003REN10026.
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Les polyamines, nécessaires à la croissance cellulaire, sont synthétisées dans la cellule grâce à l'ornithine dcarboxylase (ODC). Les sources exogènes de polyamines sont l'alimentation et la flore intestinale : un traitement comportant un inhibiteur de l'ODC (DFMO), une alimentation pauvre en polyamines et une antibiothérapie intestinale permet d'inhiber à 95 % la croissance tumorale chez l'animal. Il est impossible d'appliquer cette tri-thérapie nutritionnelle à l'homme : la DFMO n'est pas disponible sur le marché. Nos travaux ont consisté à déterminer s'il existe un lien entre stress oxydatif et métabolisme des polyamines et s'il est possible d'utiliser des antioxydants en remplacement de la DFMO. Nos résultats indiquent que les antioxydants n'inhibent pas assez l'ODC pour obtenir un effet anti-tumoral satisfaisant, mais permettent d'améliorer l'état général, de réduire la cachexie et de stimuler la synthèse des protéines impliquées dans la défense immunitaire.
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Navarro, Martin M. "SENSING DEVELOPMENT OF A SOYBEAN CANOPY UNDER P OR K NUTRITIONAL STRESS." UKnowledge, 2012. http://uknowledge.uky.edu/pss_etds/12.
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The normalized difference vegetative index (NDVI) has been correlated with physiological plant parameters and used to evaluate plant growth. There is little information about the use of this technique to detect soybean nutrient deficiencies. The objective of this work was to determine the ability of the NDVI sensor to detect P and K deficiencies, and grain yield reduction, in soybean. During 2010 and 2011, NDVI measurements were made on a soybean field trial site known to exhibit yield responses to both P and K nutrition. Four replicates of 8 levels each of P and K nutrition were evaluated. The NDVI measurements were made with an active proximal sensor held parallel to the soil surface every seven days after V2, and until R2. At each measurement a mean NDVI value was found for each plot. Phosphorus deficiency was detected with the first NDVI measurement. Potassium deficiency was first detected just after V4. Differences in NDVI values due to P or K nutrition increased with continued crop development. There were significant R1 leaf composition and grain yield responses to improved P or K nutrition. The active proximal sensor was able to detect soybean growth differences due to P or K deficiencies in soybean.
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Valla, Frédéric. "Évaluation nutritionnelle systémique de l’enfant en réanimation pédiatrique." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1281/document.
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La malnutrition à l’admission en réanimation pédiatrique est fréquente et associée à une augmentation de la morbi-mortalité. Néanmoins, la plupart des études, limitées à une évaluation statique du statut nutritionnel, ne permettent pas une analyse fine de l’impact de la malnutrition. Une approche systémique associerait en plus d’une évaluation nutritionnelle statique, une analyse dynamique dans le temps, une analyse de la composition corporelle et une analyse physiopathologique et étiologique. Cette approche globale a été appliquée dans 4 études prospectives observationnelles, incluant des enfants sévèrement agressés de plus de 36 semaines d’âge corrigé. Il en ressort que la dénutrition globale à l’admission est fréquente (23,7%) et que la cassure des courbes de croissance avant l’admission est associée à une augmentation de la durée de séjour de 3 jours. L’enfant sévèrement agressé présente à l’admission des taux plasmatiques abaissés de 6 micronutriments impliqués dans le stress oxydant (Sélénium, Zinc, Cuivre, Vitamines C, E et bêta-carotène), proportionnellement au nombre de défaillances d’organe. La dénutrition globale et la fonte musculaire acquises en cours de séjour sont des phénomènes fréquents, précoces et importants, associés à une durée de séjour prolongée. Les changements métaboliques liés à l’agression sévère conduisent à une dénutrition. Ces processus adaptatifs sont parfois dépassés et la dénutrition pourra à son tour aggraver le pronostic. La bonne compréhension de la physiopathologie sous-jacente et un suivi systémique et systématique du statut nutritionnel sont les éléments indispensables à l’évaluation des stratégies nutritionnellesMalnutrition at pediatric Intensive care unit (PICU) admission is frequent and associated with impaired outcomes. However, most studies have focused solely on a static definition. A holistic approach would improve the description of malnutrition: this would include both a static and dynamic assessment of nutritional status, together with body composition assessment and with malnutrition classified based on its patho-physiology and etiology. This holistic assessment of malnutrition has been applied and examined in four observational studies which included critically ill children older than 36 gestational weeks (corrected age). These found that malnutrition was frequent at PICU admission (27.3%) and faltering growth prior to PICU admission was associated with an increased length of PICU stay (+3 days). Critically ill children present at admission with decreased plasma levels of 6 micro-nutrients (Selenium, Copper, Zinc, Vitamin C, E and beta-carotene) involved in anti-oxidative stress pathways. Nutritional status deterioration during PICU stay, and associated muscle mass loss occurred frequently and were intense. This early phenomenon was associated with extended length of PICU stay. A profound critical illness related metabolic shift leads to malnutrition as an adaptive process. However, malnutrition may also negatively impact on outcomes in this setting. These studies have led to a clearer understanding of the underlying patho-physiology. This, combined with a more systematic and holistic nutritional assessment, will enable implementation and assessment of nutritional strategies aiming to improve the functional outcome of critically ill children
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Nolin, France. "Parenteral glutamine supplementation in neonates following surgical stress." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31281.
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Our objective was to study the effect of GLN supplementation on whole body protein turnover, somatic growth and gastrointestinal tolerance to enteral feeding in neonates following surgical stress. We hypothesized that GLN in total parenteral nutrition (TPN) would (1) favor retention of lean body mass by reducing protein breakdown (PB) during the acute phase after surgery, (2) promote somatic growth, (3) decrease length of time to achieve full feeds. Protein turnover was measured in a double-blind randomized trial involving neonates admitted to the Neonatal Intensive Care Unit after major surgery. L-GLN (n = 6) was added to TPN at a dose of 200 mg/g of protein intake. Controls (n = 7) were isonitrogenous. Isotope studies were performed on Day 4 of TPN. Subjects were given a 4-hour primed constant intravenous infusion of L-[1-13C]-leucine and [15N2]-urea. In the GLN group, a 15% reduction in PB was measured (unpaired t-test, p < 0.05). There was a trend towards improved net protein balance which was statistically different from zero in the GLN group. There were no differences in somatic growth during TPN course and in the length of time to achieve full enteral feeds. Results suggest that early TPN supplemented with GLN has a beneficial sparing effect on protein metabolism in critically ill neonates after major surgical stress.
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Léonard, Anneliese. "Description et étiologie des exostoses oro-faciales : exemple d'une population thaïlandaise." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0139/document.
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Cette thèse vise à participer à une meilleure connaissance des exostoses oro-faciales comme variation anatomique et préciser leur possible utilisation en anthropologie biologique. Une nouvelle méthodologie a été conçue pour faciliter leur enregistrement tant sur restes squelettiques qu’individus vivants. L’étude a été réalisée sur une population thaïlandaise : la collection anatomique de référence de la faculté de médecine de Chiang Mai. Cette population a été choisie pour ses hautes fréquences et forte expressivité des exostoses oro-faciales, ainsi que son homogénéité génétique. Les exostoses oro-faciales ont été évaluées par présence/absence et métriquement. Leur relation au sexe, à l’âge et entre leurs différents types est détaillée et les étiologies discutées. La composante génétique est évaluée sur la base de l’homogénéité populationnelle et les liens entre exostoses et variations anatomiques dentaires et crâniennes. La composante environnementale inclut des données sur l’alimentation, le stress occlusal et la santé orale. Les exostoses oro-faciales apparaissent comme un ensemble de caractères liés entre eux et très influencés par l’âge. Toutes les exostoses sauf l’exostose palatine sont significativement liées au sexe avec prédominance masculine. Les exostoses oro-faciales n’appartiennent pas aux variations hyperostotiques. Les liens récurrents avec certaines variations anatomiques dentaires suggèrent une base génétique. Les exostoses oro-faciales émergent préférentiellement quand un maximum de dents saines et peu usées sont présentes, mais l’édentation de large étendue ne réduit pas leur prévalence, ni leur expressivité. L’influence environnementale locale n’est pas caractéristique d’un stress fonctionnel. Le régime traditionnel asiatique pourrait être une influence conséquente par son caractère promoteur du tissu osseux. La double participation génétique et environnementale au processus étiologique suggère que les exostoses oro-faciales appartiennent aux variations quasi-continuesWe aim here at participating in a better understanding of oral exostoses as an anatomical variant in order to clarify their possible use in biological anthropology. We propose a new study design that could be applied both on skeletal remains and living individuals and that allows discuss the etiology of oral exostoses. The research has been undertaken on the anatomical reference collection of the faculty of medicine of Chiang Mail, Thailand. The Thai population displays a wide array of expression of oral exostoses and a great genetic homogeneity. The oral exostoses have been scored by presence/absence and their measurements. The genetic component has been evaluated through population homogeneity and the relationships between oral exostoses and dental and cranial anatomical variants. The environmental component includes data on diet, occlusal stress and oral health. Oral exostoses appear as a set of characters linked together and strongly influenced by age. All types of oral exostoses except the palatine exostosis are correlated with sex with a male predominance. Oral exostoses do not belong to hyperostotic variants. The recurring relationships with dental anatomical traits point to a genetic basis. Oral exostoses preferentially arise when the greatest number of healthy, unworn teeth is present, although extensive edentulousnes does not lessen both their presence and their expressivity. The local environmental context is not typical of functional stress. The traditional Asian diet may be a substantial influence because of its bone-promoting composition. A dual participation of both genetic and environmental components to the etiological process implies that oral exostoses are quasi-continuous variants
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ZOCCHI, MONICA. "NUTRITIONAL ASPECTS OF MUSCULOSKELETAL PATHOPHYSIOLOGY: FOCUS ON MAGNESIUM." Doctoral thesis, Università degli Studi di Milano, 2022. https://hdl.handle.net/2434/945768.
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Il magnesio (Mg), nella sua forma biologicamente attiva di catione, è un micronutriente essenziale per la vita. Circa il 25% del Mg totale dell’organismo si trova nel muscolo scheletrico, dove è fondamentale per il rilassamento delle fibre. Una corretta assunzione di Mg con la dieta è associata a salute muscolare e a un ridotto rischio di sarcopenia. Nei paesi occidentali si registra un elevato rischio di ipomagnesemia cronica ma questo deficit nutrizionale è largamente sottostimato e il suo impatto a livello delle cellule muscolari non è ben caratterizzato. Inoltre, non è chiaro il suo contributo nella patogenesi della sarcopenia. A questo scopo, in questo lavoro sono stati utilizzati modelli di ipomagnesemia sia in vivo che in vitro. Topi nutriti per due settimane con una dieta povera di Mg hanno mostrato a livello muscolare una significativa rimodulazione dell’espressione di geni coinvolti nella rigenerazione delle fibre, nel catabolismo delle proteine, nelle dinamiche mitocondriali e nel metabolismo sia glucidico che lipidico. Questi aspetti sono stati confermati e approfonditi in vitro su mioblasti C2C12. Nel corso della miogenesi, è stata osservata una modulazione sia del livello intracellulare di Mg che dell’espressione proteica di suoi trasportatori di membrana, tra cui TRPM7, MagT1 e SLC41A1. Inoltre concentrazioni extracellulari non fisiologiche di Mg influiscono sulla capacità dei mioblasti di fondersi tra loro e, di conseguenza, provocano un difetto in miogenesi. In particolare questo danno è risultato essere connesso alla eccessiva produzione di specie reattive dell’ossigeno in condizioni di Mg non fisiologiche. Esponendo miotubi differenziati a basse concentrazioni di Mg, sono stati osservati cambiamenti morfologici, una compromissione dell’autofagia e alterazioni del metabolismo energetico. In particolare, una riduzione del livello di Mg intracellulare porta a una riduzione della glicolisi e un aumento dell’ossidazione degli acidi grassi, con conseguente diminuzione delle riserve di lipidi neutri. Questo adattamento metabolico è accompagnato anche da variazioni nell’espressione delle proteine contrattili. Tutte queste risposte metaboliche osservate in cellule esposte a basso Mg sono risultate connesse ad un significativo aumento della sintesi di ossido nitrico, una molecola segnale in grado di modulare l’attività di proteine target e di contribuire allo stress ossidativo. In conclusione, un deficit di Mg esercita un significativo impatto sulla fisiologia del muscolo scheletrico e gli effetti osservati sono sovrapponibili a caratteristiche tipiche della sarcopenia. Ciò suggerisce che alterazioni dell’omeostasi del Mg contribuiscano attivamente all’invecchiamento delle fibre muscolari.Magnesium (Mg) is a micronutrient essential to all vital processes and a quarter of body Mg is located in skeletal muscles where it is essential for fibers relaxation. It is widely known that a correct dietary Mg intake is associated to healthy skeletal muscles and to a reduced risk to develop sarcopenia. In western countries a latent risk of Mg deficiency is evident but this electrolyte imbalance is largely underestimated. Moreover, very little is known about the impact of Mg deficiency on skeletal muscle at the cellular and molecular levels and about its contribution in developing a sarcopenic and aged phenotype. With this aim, both in vivo and in vitro models of Mg deficiency were used. Mice fed two weeks with low Mg diets show a reduction in magnesemia and intramyocellular Mg content, which influences the expression of genes involved in muscle regeneration, protein catabolism, mitochondria dynamics, carbohydrates and lipids metabolism. To deeper investigate these pathways modulated by a low Mg status, in vitro experiments were performed on C2C12 myoblasts, both during myogenesis and on differentiated myotubes. New insights into the role of Mg during the myogenic process emerged. An interesting modulation of intracellular Mg content was observed during myogenesis and a coherent fluctuation in the levels of the Mg transporters TRPM7, MagT1 and SLC41A1 was found. Moreover, variations in extracellular Mg concentration impact on myoblasts fusion capacity and hence of the myogenic process in a ROS-dependent manner. C2C12-derived myotubes exposed to low Mg concentrations showed a reduced thickness, a compromised autophagic process and alterations in energy metabolism. Mg deficiency induced alterations of glucose metabolism and an increased fatty acids oxidation rate, with a consequent reduction of intracellular neutral lipids stores. This metabolic adaptation is accompanied by changes in the expression of contractile proteins and to a fast-to-slow phenotypic shift of the fibers. All these metabolic responses were found connected to the low Mg-dependent overproduction of nitric oxide which is able to modulate the activity of several target proteins and contribute to oxidative stress. Overall, Mg deficiency significantly impacts on skeletal muscle physiology and its effects overlap with typical features of a sarcopenic phenotype, thus suggesting that alterations in intramyocellular Mg status contribute to skeletal muscle aging.
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Lachili, Brahim. "Étude du stress oxydant et de son origine nutritionnelle chez la femme algérienne : conséquences de la grossesse." Université Joseph Fourier (Grenoble), 2001. http://www.theses.fr/2001GRE19013.
Full textAbstract:
Ce travail contribue à la connaissance du statut en oligo-éléments (fer, zinc, cuivre et sélénium) et en vitamines (A, E et b-Carotène) des femmes algériennes en âge de procréer et à l'accouchement. La femme algérienne en âge de procréer a un statut macronutritionnel normal (albumine et protides). En ce qui concerne les micronutriments, 9,6% des femmes en âge de procréer ont un risque biologique de déficit en zinc et 17,6 % des femmes sont en état de déplétion totale de leurs réserves en fer (ferritinémie inférieure à 12 æg/l). Par contre, aucun déficit biologique en sélénium n'est observé. Chez la femme à l'accouchement, le bilan nutritionnel est abaissé et s'associe à un déficit aggravé en micronutriments. Le stress oxydant s'avère plus sévère encore chez les femmes qui font l'objet d'une suppléméntation en fer destinée à corriger leur anémie. Notre observation amène à s'interroger sur l'inocuité de ces supplémentations. Ce stress est aggravé aussi par certaines pathologies liées à la gestation (diabète et prééclampsie). Nous notons lors de la grossesse une augmentation de certaines défenses antioxydantes (Vit E, sélénémie et GPx érythrocytaire). Nous interprétons cette augmentation comme une adaptation de l'organisme destinée à lutter contre le stress oxydant. Les conséquences médicales du stress oxydant lié à la grossesse, restent à évaluer afin d'établir une politique nutritionnelle de santé publiqueThis work aimed to investigate the trace element (Zn, Cu, Se, Fe) and vitamin (E, A, b-Caroten) status in young algerian women and at delivery. The global nutritional status as assessed by transtyrethine, albumin and protein is adequate (. . . ) More over an increased oxidative stress monitored by elevated MDA levels and decreased red cell SOD Cu-Zn is observed, especially in diabetic or preeclamptic pregnancies. We observe during pregnancy an increase in some antioxidant defenses (Vit E, selenium and SeGPx erythrocytes). We interpret our data as an adaptative process to the oxidative stress occuring during pregnancy. The clinical consequencies of the oxidative stress linked to pregnancy are not yet established and are necessary before to establish a nutritional public health politic
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McDermid, Joann M. "Antioxidant micronutrient intake and oxidative stress in persons with human immunodeficiency virus infection." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23920.
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An imbalance of the oxidant-antioxidant equilibrium has been associated with disease progression in HIV-seropositive individuals. In vitro and in vivo studies have demonstrated the efficacy of antioxidant supplementation in reducing the concentrations of oxidative stress markers. The objectives of the present cross-sectional study were to evaluate the dietary intake and nutritional supplementation practices of 24 HIV-seropositive persons in Montreal and explore the relationship between dietary intakes of antioxidant micronutrients (ascorbic acid, vitamin E, $ beta$-carotene, zinc, selenium), oxidative stress (plasma malondialdehyde (MDA), leukocyte glutathione (GSH)) and immunological indices (absolute CD4+ counts, polymorphonuclear leukocytes (PMN)). Unexpectedly, and paradoxically, a tendency to higher MDA concentrations in subjects with higher CD4+ counts was observed (r = 0.39, p $<$ 0.10). Moreover, supplementation with vitamin E was associated with significantly higher MDA concentrations (p $<$ 0.05). Ascorbic acid intake, even at levels in excess of the tissue saturation (200 mg/d) did not significantly lower MDA concentrations. Neither GSH concentrations nor CD4+ counts were significantly different between supplement users and non-users. In general, the small sample size of this study may have been in part responsible for the failure to detect statistical significance in some associations, however, trends were noted. These included the observation that vitamin supplement users were more likely to have a history of a clinical event associated with HIV infection (opportunistic infection, neoplasm, unintentional weight loss), have a longer duration of IV-seropositivity and have significantly higher MDA concentrations (p $<$ 0.05). In this study, it appears that antioxidants, and vitamin E in particular, were ineffective in reducing the elevated levels of reactive oxygen species (ROS) associated with HIV infection.
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Hamzaoui, Soufiane. "Heat stress responses in dairy goats and effects of some nutritional strategies for mitigation." Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/285552.
Full textAbstract:
En la presente tesis se han llevado a cabo 4 experimentos con cabras lecheras bajo condiciones de estrés por calor (HS) para medir la respuesta bajo las condiciones de estrés (Exp. 1 y 2) y para evaluar el aceite de soja y el propilenglicol como suplementos alimenticios (Exp. 3 y 4). En los Exp. 1 y 2, 8 cabras lecheras de raza Murciano-Granadina, a final (Exp. 1) y a mitad (Exp. 2) de lactación fueron expuestas a diferentes condiciones ambientales, utilizando jaulas metabólicas en una cámara climática. El diseño experimental fue de efecto cruzado (2 periodos de 28-35 d y 4 cabras por grupo) y las condiciones fueron: 1) temperatura neutral (TN, 15 a 20ºC día-noche) y 2) estrés por calor (HS, 12-h d a 37ºC y 12-h noche a 30ºC). La humedad se mantuvo al 40% y luz-oscuridad fue constante (12-12h). Diariamente, se midió la temperatura rectal, la frecuencia respiratoria (0800, 1200 and 1700 h) y la producción de leche, mientras que la composición de la leche y los parámetros sanguíneos fueron evaluados semanalmente. Se determinó los coeficientes de digestibilidad y el balance N y se registró el comportamiento mediante cámaras de video. Además, se realizaron tratamientos con insulina (4.6 µg/kg BW), epinefrina (2 µg/kg BW) y glucosa (0.25 g/kg BW) y se tomaron muestras de sangre para analizar insulina, NEFA y concentraciones de glucosa. En comparación con las cabras TN, las cabras HS experimentaron una mayor temperatura rectal, frecuencia respiratoria, consumo de agua y evaporación de agua. La ingesta de las cabras HS decreció un 21 y 29% en los Exp. 1 i 2, respectivamente. La leche de las cabras HS mostraron un menor porcentaje de grasa, proteína y lactosa. En comparación a las cabras TN, las cabras HS disminuyeron la concentración y la presión sanguínea del CO2 debido al jadeo y mantuvieron el pH sanguineo al bajar la concentración de HCO3–. Las cabras TN y HS tuvieron niveles similares de NEFA en sangre después de la inyección de insulina, pero después de la administración de epinefrina los valores de NEFA fueron mayores (P < 0.05) en las cabras TN que en las HS. Las cabras HS secretaron menos (P < 0.05) insulina que las cabras TN en respuesta al test de tolerancia de glucosa. Las cabras TN y HS presentaron una similar frecuencia alimentaria, aunque la duración de cada ingesta fue menor en las cabras HS que en las TN. Por otra lado, las cabras HS tuvieron una mayor frecuencia de bebida, aunque no hubo variación en la duración.
En los Exp. 3 i 4, se utilizaron 8 cabras lecheras multíparas a mitad de lactación de raza Murciano-Granadinas en un diseño de cuadrado latino 4 x 4 con 4 periodos de 21 d cada uno (14 d de adaptación, 5 d de medidas y 2 d de transición entre periodos). Las cabras fueron asignadas a 4 grupos con un diseño factorial 2 x 2. Los factores fueron la suplementación o no suplementación con aceite de soja (Exp. 3) y propilenglicol (Exp. 4) en condiciones de TN o HS iguales a lo mencionado en Exp. 1 y 2. Se evaluó la ingestión, la producción lechera, la composición de la leche y los metabolitos sanguíneos. Desde el punto de vista de salud humana, el HS mejoró el perfil de ácidos grasos de la leche debido a la disminución de los ácidos grasos saturados y el aumento de los ácidos grasos monoinsaturados sin afectar la grasa. El aceite de soja incrementó (P < 0.05) las NEFA en sangre en un 50%, la grasa de la leche en un 30% y el ácido linoleico conjugado en un 360%. La respuesta al aceite de soja fue de la misma magnitud en cabras TN y HS. Por el otro lado, la suplementación con propilenglicol aumentó los niveles de glucosa (P < 0.05) e insulina (P < 0.10), pero disminuyó (P < 0.10) la ingestión y la grasa en leche. Además, los niveles de NEFA y BHBA fueron menores en las cabras suplementadas con el propilenglicol.
En conclusion, el HS disminuyó la producción lechera entre un 3 y 10% con una marcada reducción en la proteína de la leche. El tejido lipídico de las cabras HS se volvió insensible a las hormonas lipolíticas, secretando el páncreas menor cantidad de insulina al inyectarle glucosa. El HS no afectó el número de acercamientos al comedero, pero sí redujo su duración. La suplementación con aceite de soja en condiciones HS y TN incrementó de forma similar la grasa de la leche, el ácido trans-vacénico y el ácido linoleico conjugado. Finalmente, el propienglicol incrementó el nivel de glucose e insulina sanguíneo, pero no alteró la proteína de la lecheIn the current thesis 4 experiments were carried out using dairy goats under heat stress (HS) to measure responses to HS (Exp. 1 & 2) and to evaluate soybean oil and propylene glycol as feed supplements (Exp. 3 & 4). In Exp. 1 & 2, 8 Murciano-Granadina dairy goats in late (Exp. 1) and mid (Exp. 2) lactation were exposed to different ambient conditions, using metabolic cages in a climatic chamber. Experimental design was a crossover (2 periods of 28-35 d and 4 goats each), and conditions were: 1) thermal neutral (TN, 15 to 20°C day-night), and 2) heat stress (HS, 12-h day at 37°C and 12-h night at 30°C). Humidity was maintained at 40% and light-dark was constant (12-12 h). Rectal temperature and respiratory rate (0800, 1200 and 1700 h) and milk yield were recorded daily, whereas milk composition and blood parameters were evaluated weekly. Digestibility coefficients and N balance were determined and behavior was recorded by video cameras. Moreover, challenges with insulin (4.6 µg/kg BW), epinephrine (2 µg/kg BW) and glucose (0.25 g/kg BW) were done and blood samples were collected for the analysis insulin, NEFA and glucose concentrations. Compared to TN goats, HS goats experienced greater rectal temperature, respiratory rate, water intake, and water evaporation. Intake of HS goats decreased by 21 and 29 in Exp. 1 and 2, respectively. Milk of HS goats contained lower fat, protein and lactose. Panting reduced concentration and pressure of CO2 in blood of HS goats, but they were able to maintain their blood pH similar to TN group by lowering HCO3– in blood. The TN and HS goats had similar blood NEFA after insulin injection, but NEFA values were greater (P < 0.05) in TN than HS goats after epinephrine administration. The HS goats secreted lower (P < 0.05) amounts of insulin than TN goats in response to the glucose tolerance test. Furthermore, TN and HS goats had similar eating bouts, but the duration of each bout was lower in HS than in TN. On the other hand, HS had greater number of drinking bouts with no change in drinking bout durations. In Exp. 3 & 4, 8 multiparous Murciano-Granadina dairy goats at mid lactation were used in a replicated 4 × 4 Latin square design with 4 periods; 21 d each (14 d adaptation, 5 d for measurements and 2 d transition between periods). Goats were allocated to one of 4 treatments in a 2 x 2 factorial arrangement. Factors were supplementation or not with soybean oil (Exp. 3) or propylene glycol (Exp.4, and TN or HS conditions similar to Exp. 1 & 2. Feed intake, milk yield, milk composition, and blood metabolites were evaluated. From the point of view of human health, HS improved milk fatty acid profile by decreasing saturated fatty acids and increasing monounsaturated fatty acids with no effect on milk fat content. The soybean oil increased (P < 0.05) on average blood NEFA by 50%, milk fat by 30%, and conjugated linoleic acid by 360%. The response to soybean oil was with the same magnitude in thermo-neutral and heat stress conditions. On the other hand, the supplementation with propylene glycol increased blood glucose (P < 0.05) and tended to increase (P < 0.10) blood insulin, but dry matter intake and milk fat decreased (P < 0.10). Furthermore, blood NEFA and β-hydroxybutyrate acid decreased (P < 0.05) by propylene glycol. In conclusion, heat stress decreased milk yield by 3 to 10% with a marked reduction in milk protein. Lipid tissue of heat-stressed dairy goats became insensitive to lipolytic hormones and their pancreas secreted lower insulin when glucose was injected. Heat stress had no effect on eating bouts, but the time of each eating bout was shorter. The supplementation with soybean oil increased milk fat, trans-vaccenic acid and conjugated linoleic acid similarly in thermo-neutral as well as in heat stress conditions. Although propylene glycol increased blood glucose and insulin, no change in milk protein was observed.
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au, dbeatty@murdoch edu, and David Beatty. "Prolonged and continuous heat stress in cattle: Physiology, welfare, and electrolyte and nutritional interventions." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060831.144000.
Full textAbstract:
The live export of cattle is an important industry for Australia. Concerns have arisen about animal welfare and in particular heat stress which may cause production losses and death. Cattle shipped live to the Middle East from a southern Australian winter can face continuous and prolonged periods of high heat and humidity as they cross the equator and arrive into a northern hemisphere summer, leading to heat stress and excessive heat load. Some live animal exporters treat heat stressed cattle with electrolyte supplements, but no scientific data exists as to whether this is beneficial to cattle in these unique environmental conditions.
In response to industrys concerns, the experiments described here monitored the physiological responses of Bos taurus and Bos indicus to conditions similar to those experienced by cattle being shipped from southern Australian to the Middle East. Initial experiments were conducted in climate controlled rooms at Murdoch University where intensive monitoring was possible. In the Bos taurus, increases in core body temperature, reductions in feed intake, and increased water intake were measured. There were also changes in blood gas variables consistent with the observed panting causing a compensated respiratory alkalosis. Following the heating period, there were decreases in blood and urinary pH. Bos indicus showed similar responses to the heat, but the changes were less pronounced at the temperatures tested. A pair feeding experiment was conducted to separate the effects of heat from the reductions in feed intake, and this indicated that the major measured effects were due to the responses to heat. On the basis of the measured responses, an electrolyte supplement was formulated and tested on Bos taurus, in the climate controlled rooms, and then on a commercial live export vessel. Results from these experiments indicated improved buffering capacity and a weight advantage for supplemented cattle, even in the absence of extreme heat stress.
A final experiment investigated the effects of amount and quality of roughage in a pelleted feed on core and rumen temperature and feed intakes in Bos taurus subjected to hot environmental conditions in climate controlled rooms at Murdoch University. Both pelleted feeds had approximately the same metabolisable energy and crude protein but differed in content and type of roughage. There were no differences in feed intake, core temperature or rumen temperature between diets.
This work has led to a greater understanding of the physiological responses of cattle to prolonged and continuous high heat and humidity, the requirements and effects of supplemental electrolytes in these conditions, and the effect of manipulating export diets. The demonstration of advantages in weight and buffering capacity with the electrolyte supplement highlights future areas of research to investigate electrolyte doses, route and types of supplementation, and dietary manipulation.
29
Garrison, Lance Preston. "The influence of physical transport and nutritional stress on the zoeae of estuarine crabs." W&M ScholarWorks, 1997. http://web.vims.edu/library/Theses/Garrison97.pdf.
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30
Beatty, David Thomas. "Prolonged and continuous heat stress in cattle: physiology, welfare, and electrolyte and nutritional interventions." Thesis, Beatty, David Thomas (2005) Prolonged and continuous heat stress in cattle: physiology, welfare, and electrolyte and nutritional interventions. PhD thesis, Murdoch University, 2005. https://researchrepository.murdoch.edu.au/id/eprint/258/.
Full textAbstract:
The live export of cattle is an important industry for Australia. Concerns have arisen about animal welfare and in particular heat stress which may cause production losses and death. Cattle shipped live to the Middle East from a southern Australian winter can face continuous and prolonged periods of high heat and humidity as they cross the equator and arrive into a northern hemisphere summer, leading to heat stress and excessive heat load. Some live animal exporters treat heat stressed cattle with electrolyte supplements, but no scientific data exists as to whether this is beneficial to cattle in these unique environmental conditions.
In response to industry's concerns, the experiments described here monitored the physiological responses of Bos taurus and Bos indicus to conditions similar to those experienced by cattle being shipped from southern Australian to the Middle East. Initial experiments were conducted in climate controlled rooms at Murdoch University where intensive monitoring was possible. In the Bos taurus, increases in core body temperature, reductions in feed intake, and increased water intake were measured. There were also changes in blood gas variables consistent with the observed panting causing a compensated respiratory alkalosis. Following the heating period, there were decreases in blood and urinary pH. Bos indicus showed similar responses to the heat, but the changes were less pronounced at the temperatures tested. A pair feeding experiment was conducted to separate the effects of heat from the reductions in feed intake, and this indicated that the major measured effects were due to the responses to heat. On the basis of the measured responses, an electrolyte supplement was formulated and tested on Bos taurus, in the climate controlled rooms, and then on a commercial live export vessel. Results from these experiments indicated improved buffering capacity and a weight advantage for supplemented cattle, even in the absence of extreme heat stress.
A final experiment investigated the effects of amount and quality of roughage in a pelleted feed on core and rumen temperature and feed intakes in Bos taurus subjected to hot environmental conditions in climate controlled rooms at Murdoch University. Both pelleted feeds had approximately the same metabolisable energy and crude protein but differed in content and type of roughage. There were no differences in feed intake, core temperature or rumen temperature between diets.
This work has led to a greater understanding of the physiological responses of cattle to prolonged and continuous high heat and humidity, the requirements and effects of supplemental electrolytes in these conditions, and the effect of manipulating export diets. The demonstration of advantages in weight and buffering capacity with the electrolyte supplement highlights future areas of research to investigate electrolyte doses, route and types of supplementation, and dietary manipulation.
31
Beatty, David Thomas. "Prolonged and continuous heat stress in cattle : physiology, welfare, and electrolyte and nutritional interventions /." Beatty, David Thomas (2005) Prolonged and continuous heat stress in cattle: physiology, welfare, and electrolyte and nutritional interventions. PhD thesis, Murdoch University, 2005. http://researchrepository.murdoch.edu.au/258/.
Full textAbstract:
The live export of cattle is an important industry for Australia. Concerns have arisen about animal welfare and in particular heat stress which may cause production losses and death. Cattle shipped live to the Middle East from a southern Australian winter can face continuous and prolonged periods of high heat and humidity as they cross the equator and arrive into a northern hemisphere summer, leading to heat stress and excessive heat load. Some live animal exporters treat heat stressed cattle with electrolyte supplements, but no scientific data exists as to whether this is beneficial to cattle in these unique environmental conditions.
In response to industry's concerns, the experiments described here monitored the physiological responses of Bos taurus and Bos indicus to conditions similar to those experienced by cattle being shipped from southern Australian to the Middle East. Initial experiments were conducted in climate controlled rooms at Murdoch University where intensive monitoring was possible. In the Bos taurus, increases in core body temperature, reductions in feed intake, and increased water intake were measured. There were also changes in blood gas variables consistent with the observed panting causing a compensated respiratory alkalosis. Following the heating period, there were decreases in blood and urinary pH. Bos indicus showed similar responses to the heat, but the changes were less pronounced at the temperatures tested. A pair feeding experiment was conducted to separate the effects of heat from the reductions in feed intake, and this indicated that the major measured effects were due to the responses to heat. On the basis of the measured responses, an electrolyte supplement was formulated and tested on Bos taurus, in the climate controlled rooms, and then on a commercial live export vessel. Results from these experiments indicated improved buffering capacity and a weight advantage for supplemented cattle, even in the absence of extreme heat stress.
A final experiment investigated the effects of amount and quality of roughage in a pelleted feed on core and rumen temperature and feed intakes in Bos taurus subjected to hot environmental conditions in climate controlled rooms at Murdoch University. Both pelleted feeds had approximately the same metabolisable energy and crude protein but differed in content and type of roughage. There were no differences in feed intake, core temperature or rumen temperature between diets.
This work has led to a greater understanding of the physiological responses of cattle to prolonged and continuous high heat and humidity, the requirements and effects of supplemental electrolytes in these conditions, and the effect of manipulating export diets. The demonstration of advantages in weight and buffering capacity with the electrolyte supplement highlights future areas of research to investigate electrolyte doses, route and types of supplementation, and dietary manipulation.
32
Le, Roy Chloé. "Stress, opioïdes et sensibilisation à la douleur : thérapie nutritionnelle par un régime appauvri en polyamines." Bordeaux 2, 2008. http://www.theses.fr/2008BOR21514.
Full textAbstract:
Notre travail de thèse a concerné l'étude des processus de sensibilisation à la douleur et d'une thérapie nutritionnelle par un régime appauvri en polyamines afin de prévenir le développement d'un tel processus. Nos résultats ont montré que des stress environnementaux non nociceptifs, qu induisent une libération de peptides opioides endogènes, amplifient de manière durable l'hyperalgésie induite par une inflammation. Ainsi, l'exposition à des événements stressants conduirait à une sensibilisation latente à la douleur. Nous avons également montré qu'une très faible dose de fentanyl (50 ng/kg), qui induit une analgésie chez des animaux naifs, induit, à l'opposé, une hyperalgésie chez des animaux ayant été exposés à des stress. Ce test pharmacologique permet de détecter et de prédire la capacité ders animaux à développer une sensibilisation à la douleur. En parallèle, notre étude a montré que plus le taux de polyamines de l'alimentation est élevé, plus les animaux sont hypersensibles à la douleur. Les polyamines sont des modulateurs positifs des récepteurs de type NMDA impliqués dans les processus de sensibilisation à la douleur. Ainsi, d'un point de vue thérapeutique, un traitement par un régime appauvri en polyamines réduit considérablement l'hypersensibilité à la douleur induite par l'exposition à des événements stressants et permet également de prévenir l'état affectif négatif induit par l'administration d'opiooides exogènes (fentanyl ou héroine). Ces données précliniques suggèrent que la thérapie nutritionnelle par un régime appauvri en polyamines pourrait représenter une stratégie innovante et particulièrement bénéfique pour améliorer la prise en charge de la douleurThe aim of this work was to study the pain sensitization process and to evaluate a polyamine-deficient diet as a nutritional therapy to prevent or treat this process. We showed that non-nociceptive environmental stress, which induce endogenous opioid release, enhance the hyperalgesia associated with an inflammatory pain. Thus, pre-stressful events could lead to latent pain sensitization. Moreover, it was possible to discriminate stressed versus unstressed animals through the type of response to a fentanyl ultra-low dose test (50 ng/kg), i. E. Hyperalgesia or analgesia, respectively, this pharmacological test permits the prediction of pain sensitivity level. In this study, we showed that the higher the level of polyamines of food, the higher animals are hypersensitive to pain. Polyamines are positive modulators of NMDA receptors which are implicated in pain sensitization process. Thus, from a therapeutic viewpoint, a polyamine-deficient diet reduces pain hypersensitivity induced by pre-stressful events and long-lasting anxiety-like behavior induced by opioids (fentanyl or heroin). Altogether this preclinical data suggests that a nutritional therapy based on a polyamine-deficient diet could improve therapeutic strategies to reduce pain vulnerability. Moreover, this safe strategy could limit the risk of transition from acute to chronic pain, especially in patients with a severe psychological stress history
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Lamas, Bruno. "Caractérisation de l'activité fonctionnelle et métabolique des cellules NK en situation de stress nutritionnels : approche expérimentale in vitro et in vivo." Thesis, Clermont-Ferrand 1, 2012. http://www.theses.fr/2012CLF1PP02/document.
Full textAbstract:
Les cellules Natural Killer (NK), actrices majeures de la vigilance anti-tumorale, sont modulées par des facteurs nutritionnels et métaboliques. L'inhibition de leur activité favorise le développement tumoral. Un régime alimentaire hypercalorique induisant l'obésité est un facteur de risque de développer un cancer du sein. Au niveau du micro-environnement tumoral mammaire, la biodisponibilité en certaines molécules contrôle non seulement les cellules néoplasiques mais, également les cellules immunes infiltrées. Ainsi, la leptine, sécrétée à forte concentration par les adipocytes mammaires, pourrait favoriser la croissance tumorale et altérer les cellules NK. L'arginine fortement consommée par les cellules tumorales et les cellules suppresseurs dérivées des myéloïdes pourrait faire défaut aux cellules NK. L'objectif de cette thèse est de caractériser les activités fonctionnelles et métaboliques des cellules NK en situation de stress nutritionnel. Dans un premier temps, nous avons exploré, in vivo, l'impact d'un régime hypercalorique sur l'activité des cellules NK et sur le développement tumoral mammaire. Ensuite, nous avons cherché à identifier les potentielles altérations fonctionnelles des cellules NK en mimant, in vitro, les conditions retrouvées au niveau du micro-environnement tumoral telles que la présence de concentration élevée en leptine et la déplétion en arginine. Des souris Balb-c "nude" femelles ont été soumises à un régime hypercalorique (HC) versus une diète normo-calorique (NC) pendant 6 mois. Au bout de 5 mois, des cellules tumorales mammaires (MCF-7 ; groupes NCT et HCT) ou le véhicule (groupes NC et HC) ont été implantés au niveau de la quatrième paire de glandes mammaires. Sous régime HC, le développement tumoral s'accompagne d'une perte de masse grasse, de masse maigre et de poids corporel avec un volume et un poids de tumeur augmentés. Cette diète induit au niveau tumoral une sur-expression des ARNm d'enzymes impliquées dans la glycolyse et une sous-expression des acteurs du cycle de Krebs. Sous régime HC, l'expression de la caspase 3 clivée et des récepteurs des oestrogènes β et de la progestérone est réduite alors que celle du Ki67 est accrue. Les cellules NK des souris HC ont une cytotoxicité diminuée. Bien que la présence de tumeur stimule l'activité lytique des cellules NK, la cytotoxicité de ces cellules reste inférieure dans le groupe HCT comparativement à celle du groupe NCT. La leptine stimule, in vitro, de façon dose-dépendante l'activité métabolique des cellules NK. A fortes concentrations, elle active leur cytotoxicité vis-à-vis des cellules cibles MDA-MB-231. Cet effet passe par une stimulation de l'expression de TRAIL et de l'IFN-γ par les cellules NK. En revanche, vis-à-vis des cellules cibles MCF7, les cellules NK présentent une activité lytique réduite en présence de fortes concentrations de leptine, probablement en lien avec une réduction de l'expression de la perforine. En réponse à une déplétion en arginine dans le milieu de culture, la prolifération et la cytotoxicité des cellules NK sont abaissées. L'altération de la reconnaissance des cellules cibles par les récepteurs NKp46 et NKp30, la moindre transmission du signal activateur par la chaine ζ et la faible production d'IFN-γ peuvent expliquer l'inhibition de la cytotoxicité des cellules NK. Ainsi, un apport énergétique élevé favorise le développement tumoral mammaire notamment eninhibant la cytotoxicité des cellules NK. De plus, la leptine à fortes concentrations stimule ou réduit, in vitro, la cytotoxicité des cellules NK selon la nature des cellules cancéreuses mammaires cibles. Une déplétion en arginine, in vitro, quant à elle, inhibe la prolifération et la cytotoxicité des cellules NK. Ces travaux contribuent à mieux comprendre l'impact du micro-environnement sur la réponse antitumorale des cellules NKNatural killer (NK) cells are critical mediators of anti-tumor immunity. A high-calorie diet inducing obesity is associated with breast cancer development. NK cells are modulated by dietary and metabolic factors and a decrease in their lytic activity promotes mammary tumor development. In the breast microenvironment, high concentration of leptin can be secreted by mammary adipocytes and thereby could stimulate tumor growth and control immune cells. Arginine, strongly consumed by tumor and myeloid-derived suppressor cells, could be lacking to NK cells. The aim of this work is to characterize the functional and metabolic activities of NK cells in response to nutritional stress. Initially, we explored in vivo the impact of a high-calorie diet on NK cells activity and mammary tumor development. Then, we identified potential functional alterations in NK cells by mimicking the conditions found in the tumor microenvironment such as the presence of high leptin concentration and arginine depletion. Female Balb-c nude mice were fed a high-caloric diet (HC) versus a standard caloric diet (SC) for 6 months. After five months, mammary tumor cells (MCF-7, SCT, HCT) or MatrigelTM (SC, HC) were implanted into the fourth mammary fat pads. The tumor development in HC diet-fed mice was associated with a decrease in body weight, body fat and lean mass and an increase in volume and weight of tumors. This diet induced tumor over-expression, at the transcriptional level, of enzymes involved in glycolysis and a down-expression of citrate cycle actors. Protein tumor levels of cleaved caspase 3, estrogen β and progesterone receptors were reduced while Ki67 was increased in the HC diet-fed mice. NK cell cytotoxicity of HC diet-fed mice was reduced. Although the presence of tumor stimulated NK cell lytic activity, this later was lower in the HCT group compared to the one of SCT mice. In vitro, leptin stimulated, in dose-dependent manner, the metabolic activity of NK cells. High leptin concentrations enhanced NK cell cytotoxicity against the MDA-MB-231 target cells. This phenomenon involved the increase of expression of TRAIL and IFN-γ in NK cells. However, against the MCF-7 target cells, NK cell lytic activity was reduced in the presence of high concentrations of leptin, probably in link to the decreased perforin expression. NK cell proliferation and cytotoxicity were impaired in response to arginine depletion. This inhibition of NK cell cytotoxicity could be linked to a low target cells recognition by NKp46 and NKp30, a reduced activating signal transmission by ζ chain and a low production of IFN-γ. Thus, high energy intake promotes mammary tumor development in particular by inhibiting NK cell cytotoxicity. In vitro, high leptin concentrations stimulate or reduce NK cell cytotoxicity according to the breast cancer cell targets. Furthermore, arginine depletion inhibits NK cell proliferation and cytotoxicity in vitro. These findings provide insight into the microenvironment impacts on NK cell antitumor response in tumor development
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Kroscher, Kellie Ann. "Nutritional Strategies to Improve Pig Growth and Performance." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/100306.
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Many factors influence the efficiency of muscle growth including genetics, nutrition, and environment. The neonatal period is characterized as a time of rapid growth. Growth rate is reduced during neonatal nutrient restriction possibly due to altered satellite cell activity which can permanently alter growth potential. Therefore, optimal nutrition is important for maximizing the growth potential of the animal. Heat stress leads to changes in digestion and metabolism, thus alters nutrient availability to muscle. Heat stress is a prevalent problem in the agriculture industry resulting in great economic losses due to reduced growth, fertility, and increased morbidity. The use of functional feed additives is a potential strategy to mitigate these negative effects. The objective of this dissertation was to investigate nutritional strategies to improve growth in pigs during key malleable periods. Three nutritional studies were conducted to discern the optimal inclusion levels of calcium phosphate, energy, and protein in the diet to maximize neonatal muscle growth. Adequate dietary calcium phosphate was most efficient for satellite cell function which may be mediated by micro-RNA. Differentiation promoting miR-206 and correspondingly the fusion rate was highest in adequate calcium phosphate diets. Excess protein diets enhanced body and muscle growth, while deficient protein was detrimental to growth. Dietary protein treatments altered energy metabolism genes, and genes regulating protein degradation were upregulated in deficient protein diets. Dietary energy levels did not influence body weight, however feed efficiency improved with energy balance. Excess energy diets had the lowest fusion rates and the lowest differentiation promoting miR-1 expression. These data suggest that nutrient inclusion levels are important for satellite cell function and may mediate satellite cell activity through the expression of micro-RNAs. The final study sought to discern the ability of supplementation of an artificial high-intensity sweetener and capsicum oleoresin to mitigate the negative effects of heat stress on pig performance. Heat stress leads to increased body temperature and respiration and was detrimental to metabolic flexibility. Supplementation helped improve feed efficiency and maintain metabolic flexibility. These data indicate that supplementation may be an efficient strategy to mitigate heat stress.Doctor of Philosophy
Muscle is an important tissue to consider when optimizing growing conditions in feed animals due to its function as a consumer good. Many factors influence the efficiency of muscle growth including genetics, nutrition, and environment. Fractional growth rates are highest during the neonatal period and animals require adequate nutrients to facilitate this growth. Nutrient restriction reduces growth rate and can lead to permanent changes the animals' body size and composition later in life. Therefore, optimal nutrition is important for maximizing the growth potential of the animal. While the nutrients in feed can be controlled to improve growth, other factors are more difficult to regulate. Heat stress is a prevalent problem in the agriculture industry resulting in great economic losses due to reduced growth, fertility, and increased morbidity. The use of functional feed additives is a potential strategy to alleviate these negative effects. The objective of this dissertation was to investigate nutritional strategies to improve growth in pigs during key malleable periods. Three nutritional studies were conducted to determine the optimal inclusion levels of calcium phosphate, energy, and protein in the diet to maximize neonatal muscle growth. Satellite cells are muscle-specific stem cells that help facilitate the growth of muscle. Altering the ability of satellite cells to proliferate and fuse impairs the ability of muscle to grow and repair. Adequate dietary calcium phosphate was most efficient for satellite cell function. Excess protein diets enhanced body and muscle growth, while deficient protein was detrimental to growth. Dietary protein treatments altered energy metabolism genes, and genes regulating protein degradation were upregulated in deficient protein diets. Dietary energy levels did not influence body weight, however, feed efficiency improved with energy balance. Satellite cells from excess energy diets had the lowest fusion rates. These data suggest that nutrient inclusion levels are important for satellite cell function and growth. The final study sought to discern the ability of the supplementation of an artificial high-intensity sweetener and capsicum oleoresin to mitigate the negative effects of heat stress on pig performance. Heat stress leads to increased body temperature and respiration and was detrimental to metabolic flexibility. Supplementation helped improve feed efficiency and maintain metabolic flexibility. These data indicate that supplementation may be an efficient strategy to mitigate heat stress.
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Clero, Delphine. "Intérêt d'une supplémentation nutritionnelle adaptée dans l'optimisation de la performance physique de travail du chien d'utilité." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066175/document.
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La nutrition est un élément clé du maintien de la performance opérationnelle chez le chien de service, lequel fait souvent face à des périodes de travail intense suivies de périodes de récupération de courte durée, l’enchaînement des efforts se répétant fréquemment sur plusieurs jours. Afin d’optimiser la performance, d’éviter l’émergence de pathologies liées à l’effort physique et aux contraintes mentales, et d’améliorer la récupération, l’alimentation est maintenant intégrée de manière prépondérante dans la préparation des athlètes de haut niveau que sont ces chiens. Les objectifs de ce travail furent de : (1) concevoir un supplément nutritionnel de mise/maintien en condition et en étudier les impacts biologiques lorsqu’il est distribué avant et pendant l’effort physique, en s’intéressant plus particulièrement à son adaptation au métabolisme spécifique de l’effort demandé ; (2) concevoir un supplément nutritionnel de récupération et en étudier les impacts biologiques lorsque distribué après l’effort physique en s’axant sur les capacités de récupération à court terme. Le premier supplément développé dans cette thèse se présente sous forme extrudée spécialement conçu, et contenant des acides gras à chaînes courtes et moyennes, associés à un complexe antioxydant. Distribué une heure avant, et au bout de vingt minutes d’effort dans un protocole de course en continu chez le chien de recherche de personnes, il a généré une amélioration de la réponse de l’organisme à l’exercice via un impact positif sur les paramètres physiologiques cardiovasculaires, l’augmentation des triglycérides circulants en début d’effort, et la moindre expression plasmatique de marqueurs pro-inflammatoires et du stress oxydatif dans le groupe supplémenté. Notre deuxième étude, portant sur une supplémentation post-effort chez le chien militaire, a pour objectif d’observer l’impact d’un mélange de maltodextrines (1,5g/kg de poids corporel) et protéines auparavant sélectionnée (0,3g/kg de poids corporel) distribué immédiatement après effort, durant trois périodes d’exercice intense séparées par une heure de repos au cours d’une même journée. Nos résultats montrent une moindre augmentation plasmatique des marqueurs de l’inflammation et des témoins de lésions musculaires dans le groupe supplémenté. Des études complémentaires sont indispensables à envisager pour adapter la supplémentation à chaque typologie d’effort (endurance, mixte, résistance), en testant différents apports qualitatifs et quantitatifs. Elles permettront également de préciser les moments optimaux de distribution de celle-ci (prise unique ou fractionné, délai par rapport à l’effort), et de l’adapter aux conditions environnementales (en particulier les climats chauds, sources de nombreux problèmes chez les chiens de service projetés en opérations extérieures)Nutrition is a key point in order to maintain performance during operationnal missions in the service dog, who often faces intense periods of work, followed by short resting periods, with a high number of working periods during several consecutive days. To optimise performance, reduce pathologies related to an intense physical exercise and mental stress and improve recovery, nutrition is now considered as one of the most important point in those elite athletes. This work objective were : (1) to develop a nutritionnal supplementation to set and maintain physical conditions when distributed before and during physical exercise, focusing our approach on the necessary adaptation to the specific metabolism involved during the exercise ; (2) to develop a nutritionnal supplementation for the recovery period, distributed just after the exercise and study the consequences of its distribution on biological markers during short term recovery period. The first supplement develop in this work contain short and medium chains fatty acids associated with an antioxidant complex. Given one hour before the work, and after a twenty minutes run during a continuous running test performed on search and rescue dogs, this supplement shows positive impacts on cardiovascular parameters, an increase of triglycerids at the onset of exercise, a reduction of plasmatic expression of proinflammatory and oxidative stress markers in the supplemented group. Our second study focusses on postexercise nutritionnal supplementation in the military dog, in order to observe impacts on a mix of maltodextrins (1.5g/kg body weight) and proteins (0.3g/kg body weight) provided just after the exercise, during three periodsof intense exercise separated by one hour rest periods during a single day. Our results include a reduction of plasmatic inflammatory markers production and of mucular lesions markers in the supplemented group. Further studies are required in order to adapt nutitionnal supplementation to each type of exercise (endurance, mix, resistance), by testing different qualitative and quantitative inputs. They will also permit to precise optimal timing for its distribution (single or fractionned inputs, timing before or after the exercise), and to adapt it to environmental conditions (especially hot climate, that is a cause of numerous problems for service dogs sent to oversees operations)
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Davey, Trish. "Nutritional influences on bone health, stress fracture risk and training progression in Royal Marine recruits." Thesis, University of Surrey, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.583332.
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Nutritional factors affecting bone health throughout the lifecvcle has received considerable attention in the literature but little is known about the influence of nutrition on stress fracture (SF) risk. Royal Marine (RM) recruits undergo a 32-week arduous military training programme, where the prevalence of SF has been ~5% over recent years. The Institute of Naval Medicine was tasked by Surgeon General to investigate risk factors associated with stress fracture during RM training at the Commando Training Centre Royal Marines. The present thesis focuses on the nutritional aspects of this work, with the primary aim to identify the influence of past and present dietary intake and nutritional status on SF risk and bone health in RM recruits. A bespoke dietary assessment tool was developed to investigate nutritional intake relative to SF risk and training success in a cohort of RM recruits (n=545). No aspects of diet during training were associated with SF risk. However, recruits with a higher energy intake during training were more likely to successfully complete training (P<0.05). Poor aerobic fitness, low body mass (less than 65 kg) and small thigh girth were independent risk factors for SF (n=27; P<0.05). In a larger cohort of RM recruits (n=1090), childhood (0-12 y), adolescent (12-18 y) and pre-RM training diets were assessed with a food frequency questionnaire. Vitamin 0 and micronutrient status were assessed in serum blood samples. Childhood milk intake and adolescent fruit and vegetable intakes were associated with bone quality (assessed by Broadband Ultrasound Attenuation) (P<0.05). Low milk intake during childhood, and high intake of fizzy drinks during adolescence, were associated with increased SF risk (n=75; P<0.05). Importantly, serum 25(OH)D (as a marker of vitamin 0 status) <60 nrnol.L" was associated with increased SF risk (P<0.05). Stress fractured recruits (n=65) and matched controls (n=65) underwent Dual Energy X-ray Absorptiometry and peripheral Quantitative Computed Tomography scanning. Stress fractured recruits had lower bone density of the lumbar spine and hip, and narrower tibiae than their matched controls. These novel data suggest an important role for lifestyle factors in the pathogenesis of SF in a military population, with concomitant bone density/structure differences at key fracture sites. Further research (including a possible vitamin D supplementation intervention) is warranted.
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Thornton, Elizabeth Claire. "Identification and characterisation of a novel β subunit of AMP-activated protein kinase." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312986.
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Roberts, Susan. "The effect of dietary protein source on plasma parameters related to stress and behaviour in pigs varying in their susceptibility to stress /." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56819.
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The present study was performed to determine if pigs varying in their susceptibility to stress, adapted to a casein-based diet, experience an improvement in biochemical parameters related to stress and behaviour compared to pigs adapted to the traditional western canadian cereal-based swine diet. Experiment 1 involved separating fifty-eight, 8-week old pigs according to genotype with respect to the halothane gene. Within each genotype pigs were divided into 2 groups and assigned to either a control diet or to a diet where most of the protein source was substituted for casein. All animals were adapted to diet for 6 weeks and experienced a weekly blood sampling stressor. Day 1, 14 and 35 of the plasma samples were analyzed for glucose, cortisol, ACTH, insulin, pyridoxal 5$ sp prime$-phosphate (PLP), amino acid concentrations and dopamine-$ beta$-hydroxylase (DBH) activity; metabolic indices known to be responsive to stress. Experiment 2 involved separating fifty-seven, 14-week old pigs in the same manner, then adapting the pigs to their respective diets for a period of 4 weeks. Afterwards, pigs were transferred from their pen to a novel pen-maze situation where they had their behaviour monitored for a period of one hour. Results of these experiments have revealed that (1) the stress susceptible and carrier pigs experienced reduced day 35 plasma glucose, PLP concentrations and DBH activity compared to normal pigs; (2) dietary adaptation to the casein diet resulted in greater day 14 and 35 PLP levels and day 35 essential amino acid lysine, threonine, methionine, tryptophan and arginine concentrations compared to control-adapted pigs; (3) the carrier pigs investigated their surroundings more frequently than the stress susceptible pigs, and the normal pigs engaged in the through-maze behaviour more often than the stress susceptible pigs; and (4) adaptation to the casein diet, compared to the control diet, resulted in fewer displacement-type behaviours such as drinking
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Baboulène, Laurence. "Approche nutritionnelle et biomoléculaire de la carence en calcium chez la tomate." Toulouse, INPT, 2003. http://www.theses.fr/2003INPT012A.
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Les effets d'une carence en calcium de deux, trois, quatre et cinq jours ont été étudiés chez la tomate cultivée en hydroponique. La carence totale en calcium entraînerait une remobilisation partielle d'ions calcium apoplasmique vers l'apex, afin de maintenir la croissance et le développement des méristèmes apicaux. La remobilisation d'ions calcium s'effectue, dans un premier temps, à partir du système racinaire, puis dans un deuxième temps, à partir des jeunes feuilles de rang 5, en remontant vers l'apex. Dès le quatrième jour de la carence en calcium, l'étude du profil protéique (électrophorèse SDS-PAGE) et l'analyse des protéines (MALDI-TOF), ont révélé dans les feuilles de tomates, l'induction de l'expression de la thréonine déaminase et de trois protéines PR (la prepro-enzyme subtilisine-like protéinase - P69B ; le précurseur de l'endochitinase acide de classe II - PR-3a ; une protéine P14a/P6), ainsi que la réduction de l'expression d'une protéine chloroplastique (OEE2). Ce signal est concomitant à l'apparition des symptômes visuels sur les feuilles jeunes de tomates carencées. Ce phénomène est spécifique du caractère irréversible de la carence en calcium et conduit à la mort des plantes.
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Soares, Da Costa Ricardo Jose. "The influence of sleep deprivation, cold exposure, exercise stress and nutritional intervention on selected immune responses." Thesis, Bangor University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531053.
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Holder, Sammantha. "Interpreting Diet and Nutritional Stress in Napoleon's Grand Army using Stable Carbon and Nitrogen Isotope Analysis." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5947.
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A mass grave containing the remains of at least 3269 Napoleonic soldiers from 1812 was discovered in Vilnius, Lithuania in 2001. Stable carbon and nitrogen isotopic analyses were performed on collagen from 78 femoral samples to explore dietary variation within the sample. Starvation and nutritional distress were also evaluated through the examination of nitrogen enrichment in bone collagen. Clinical studies have demonstrated that enriched nitrogen isotope values can indicate periods of nutritional stress and starvation; however, this is the first study to examine its use as a diagnostic indicator of starvation in a historical population using bone tissue. According to the carbon isotope data, a vast majority of the soldiers in this sample consumed predominantly C3 plants with only five individuals consuming more than 50% of their plant dietary protein in the form of C4 plants, with ?13C ratios for this sample ranging from -19.22‰ to -11.76‰ and a mean of -17.18‰. This conforms to expectations given that a majority of human plant consumption in Europe is C3 pathway plants. Twenty-nine individuals exhibit enriched ?15N values, with ?15N values for this sample ranging from 7.14‰ to 13.63‰ and a mean of 10.49‰. The combination of historical and isotopic evidence suggests prolonged nutritional stress may be the cause of enrichment in this sample. The results of this study demonstrate the applicability of this method on archaeological samples as a line of evidence in the investigation of starvation and famine.M.A.
Masters
Anthropology
Sciences
Anthropology
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Idrus, Zulkifli. "Stress response and habituation as influenced by nutritional and thermal factors in dwarf and normal chickens." Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/40200.
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Experiments were conducted to explore physiological, pathological, and immunological aspects of stress in chickens. Mechanisms of habituation and their association with adrenal steroids were also studied.
Degree of stress experienced during perinatal and neonatal stages was evaluated. In both stages, heterophilia and lymphopenia were noted and post-hatching heterophil to lymphocyte (H/L) ratios declined in a quadratic manner with age.
Feed restriction elicited a similar stress response, as indicated by H/L ratios in dwarfs and normals with the effect of adapting to fasting having dissipated between 12 to 16 days. Resistance to Eimeria tenella infection was greater in normals than dwarfs, and for fasted than ad libitum fed chicks. Neither genotype nor feeding regimen had an effect on antibody response to SRBC.
Frustration induced by thwarting of feeding resulted in a dramatic elevation in HIL ratios and conspicuous behavioral responses, suggesting responses to fasting may be physiologically and psychologically modulated. Provision of sand during feed withdrawal attenuated physiological responses, possibly via alteration of psychogenic components.
An experiment was designed to evaluate the impact of mild feed restriction at several ages on heat tolerance. Normal chicks feed-deprived during the neonatal stage had lower H/L ratios, improved resistance to marble spleen disease and growth during heat treatment than those fed ad libitum or fasted at older ages. A companion experiment examined habituation and concomitantly the role of glucocorticoids in stress response. Neonatal fasting-induced stress responses without concurrent increases in adrenal steroidogenesis did not enhance ability of normal chicks to withstand high ambient temperatures.
The hypothesis regarding modulatory roles of corticosteroids in neonatally-elicited adaptation was affirmed in a subsequent study. Feed withdrawal for 8 or 24 h at 36 days of age did not induce either H/L or plasma corticosterone response of chicks stressed early in life. In contrast, neither criterion provided evidence for adaptation to feed deprivation by neonates treated with an adrenal steroidogenesis blocker during the fast. corticosterone mediated inhibitory feedback regulation of the hypothalamic - pituitary - adrenal axis which down-regulates ACTH response was also evident.Ph. D.
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Clark, W. Andrew, and Eileen M. Cress. "Nutritional Issues and Positive Living in Human Immunodeficiency Virus/AIDS." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/2495.
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Key Points: (1) Nutrition management for individuals infected with HIV can be helpful in maintaining lean body weight, combating oxidative stress, reducing complications from hyperglycemia and hyperlipidemia, and managing gastrointestinal function. (2) Patients may need to be individualized to meet each individual's unique requirements. (3) Consideration should be given to including the expertise of a registered dietitian/nutritionist s part of the health care team to promote wellness in the individuals infected with HIV.
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Keech, Aaron L. "Fecal triiodothyronine assay validation using captive Steller sea lions (Eumetopias jubatus) and subsequent application to free-ranging populations to examine nutritional stress." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2817.
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Reduced availability of high energy-content prey (nutritional stress) is a predominant hypothesis to explain the decline of Steller sea lion (Eumetopias jubatus) populations in western Alaska from the late 1970's to the late 1990's. Animals may physiologically respond to consuming insufficient prey by increasing stress levels and decreasing metabolic rates. It may thus be possible to identify nutritional stress by measuring concentrations of glucocorticoids (stress) and thyroid hormones (metabolism) shed in feces. However, techniques to measure thyroid hormone concentrations from Steller sea lion feces have not been developed.
We quantified variation of triiodothyronine (T3) and thyroxine (T4) concentrations in Steller sea lion feces following injections of thyrotropin (TSH) into four captive animals. Glucocorticoids (GC) were also assayed to examine any relationship to stimulated thyroid hormone secretion. We found that fecal T3 peaked 48 h post-injection and increased 25-57% in three sea lions (all animals, p=0.03). Pre-injection GC increases indicated stress from isolation for baseline fecal collections, but post-injection increases could not be confirmed as a response to TSH injections or as a product of the study design. The results demonstrated that pre- and post-injection changes in fecal GC and T3 concentrations were consistent with predictions of an increased stress response and metabolic rate within the animals.
We then measured T3 and GC concentrations in 834 Steller sea lion fecal samples collected in 2005 and 2006 from 15 sites (haulouts and rookeries) between British Columbia and the Central Aleutian Islands. Overall, GC concentrations did not differ between haulout populations (western 2006 pre-pupping and eastern 2005 post-pupping). Fecal hard-part analyses revealed a lower energy-content diet in the western population, suggesting that diet quality is a relevant hypothesis to explain slightly higher GC concentrations found in the western population, specifically the Aleutian Islands region. However, nutritional stress could not be substantiated through T3 concentrations. The rookeries possessed the highest energy-content diets, but also exhibited a nutritional stress response with a significantly higher GC and lower T3 concentration than either haulout population (possibly related to lactation or decreased foraging opportunities), but T3 comparisons performed at scales of site and region were inconclusive.
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Thiébault, Jean-Jacques. "Stress oxydant induit par les efforts sous-maximaux chez le chien : prévention nutritionnelle et influence de l'entraînement." Rennes 1, 2008. http://www.theses.fr/2008REN1B114.
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Des efforts sous-maximaux induisent chez le chien un stress oxydant responsable d'altérations membranaires et lipoprotéiques, objectivées par des modifications de la fluidité membranaire et l'apparition de produits de la dégradation des acides gras. Ces effets dus aux radicaux libres générés peuvent être en partie inhibés par une suppléméntation en vitamine E et/ou un entraînement régulier. Une supplémentation en vitamine E pendant l'entraînement ne semble pas apporter un bénéfice très sensible et mérite d'être discutée.
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Callow, Lisa Jane. "Oxidative stress and antioxidant intake in HIV-related wasting." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33385.
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Weight loss is a common occurrence in patients with human immunodeficiency virus (HIV) and contributes to further debilitation in the acquired immune deficiency syndrome (AIDS). Wasting syndrome (WS) is defined as 10% or more unintentional weight loss from usual body weight. The etiology of WS includes alterations in metabolism, which contribute to loss of lean body mass. Cytokine driven oxidative stress may play a critical role in the metabolic pathways that lead to HIV wasting. Studies have shown that that patients infected with HIV may have a depleted antioxidant (AO) defense system, the integrity of which is needed to efficiently scavenge reactive oxygen species (ROS). It has been theorised that low AO intake may contribute to a depressed AO defense system, which drives oxidative stress (OS). In this study we examined 16 subjects who had documented WS but no active infectious process, stratified into 10 to 15% weight loss (n = 7) and over 15% weight loss (n = 9) groups, and reported on oxidative stress measures and AO intake. (Abstract shortened by UMI.)
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Jurcsisn, Jennifer. "Biomarker-Performance Associations During Nutritional and Exercise Intervention in Air Force Personnel." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1559229229507772.
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Cunha, Aline Matos. "Preconditioning with nutritional oral solution on immune modulation and oxidative stress in patients submitted to total abdominoplasty." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15956.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorThe hostâs protective mechanisms are mediated by the ability of immunonutrients in defense mechanisms, such as the inflammatory response and antioxidant capacity. Among the most investigated are glutamine, arginine and polyunsaturated fatty acids derived from fish oil, anti-inflammatory agents which act on the synthesis of eicosanoids and regulate the immune response. This study is clinical, prospective, randomized, controlled, double-blind, aimed to identify whether there is any effect arising from nutraceutical preconditioning with use of a supplement containing L-alanyl-glutamine, and arginine mixture of oils containing fatty acids ω3 (EPA, DHA and ALA) on the oxidative stress and immunomodulation in surgical trauma. The supplement was administered in one dose of 200ml/day during the preoperative period (7 days before surgery) in patients undergoing abdominoplastia. Laboratory evaluations were performed before administration of the supplement (7 days before surgery â T0), before the anesthetic induction (T1), in the 1nd postoperative day (T2) and in the 3nd postoperative day (T3). The sample (25 patients) was divided into 2 groups: SNO1 - skim milk (0% fat) and SNO2 â suplement group: Supplement with ω6: ω3 ratio of 1,4:1 and ω9: ω6 ratio of 3,2:1, Arginine (10g/day), L-alanyl-glutamine (15g/day). Values of lymphocytes, leukocytes, TBARS, glutathione peroxidase activity and concentration of total antioxidants in the three times of both groups were analyzed. There was no statistically significant difference between the control and study groups for variables lymphocytes, leukocytes, TBARS, glutathione peroxidase activity. There was a statistically significant difference between the control group and related to the concentration of total antioxidant study. Therefore, oral nutritional supplements containing L-alanyl-glutamine, arginine and oil mixture with a high ratio ω9: ω6 and low ratio ω6:ω3 containing ω3 acids (ALA, DHA and EPA) has nutraceutical effect of preconditioning the values of total antioxidants in surgical trauma in patients undergoing total abdominoplasty.
Os imunonutrientes sÃo responsÃveis pela modulaÃÃo dos mecanismos de defesa e por prepararem o organismo a possÃveis agressÃes futuras. Dentre os mais investigados estÃo a glutamina, a arginina e os Ãcidos graxos poliinsaturados derivados do Ãleo de peixe, agentes anti-inflamatÃrios que atuam na sÃntese de eicosanÃides e regulam a resposta imune. O presente estudo à clÃnico, prospectivo, randomizado, controlado, duplo-cego, cujo objetivo foi identificar se existe algum efeito decorrente do prÃ-condicionamento nutracÃutico com uso de um suplemento contendo L-alanil-glutamina, arginina e mistura de Ãleos contendo Ãcidos graxos ω3 (EPA, ALA e DHA) sobre a imunomodulaÃÃo e o estresse oxidativo no trauma cirÃrgico. O suplemento foi administrado em uma dose de 200ml/dia, durante o perÃodo prÃ-operatÃrio (7 dias antes da cirurgia), em pacientes a serem submetidos à abdominoplastia. AvaliaÃÃes laboratoriais foram realizadas antes da administraÃÃo do suplemento (7 dias antes da cirurgia- T0), antes da induÃÃo anestÃsica (T1) e no 1 pÃs-operatÃrio (T2) e no 3 pÃs-operatÃrio (T3). Vinte e cinco pacientes foram distribuÃdos em 2 grupos: SNO1 â suplemento desnatado (0% de gordura), SNO2 - suplemento com elevada relaÃÃo ω9:ω6, de 3,2:1 e baixa relaÃÃo ω6:ω3, de 1,4:1, Arginina (10g) e L-alanil-glutamina (15g). Foram analisados valores de linfÃcitos, leucÃcitos, TBARS, atividade de glutationa peroxidase e concentraÃÃo de antioxidantes totais nos trÃs tempos de ambos os grupos. NÃo houve diferenÃa estatisticamente significante entre os grupos controle e estudo para as variÃveis linfÃcitos, leucÃcitos, TBARS, atividade de glutationa peroxidase. Houve diferenÃa estatisticamente significante entre os grupos controle e estudo relacionado a concentraÃÃo de antioxidantes totais. Portanto, a suplementaÃÃo nutricional oral utilizando L-alanil-glutamina, arginina e mistura de Ãleos, com elevada relaÃÃo ω9:ω6 e baixa relaÃÃo ω6:ω3, contendo os Ãcidos ω3 (ALA, EPA e DHA) possui efeito prÃ-condicionante nutracÃutico sobre os valores de antioxidantes totais no trauma cirÃrgico de pacientes submetidos a abdominoplastia total.
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Simon, Émilie. "Participation des facteurs nutritionnels et environnementaux au vieillissement de la rétine et aux rétinopathies liées à l'âge." Thesis, Dijon, 2012. http://www.theses.fr/2012DIJOS028/document.
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Chez l’Homme, le vieillissement de la rétine peut aboutir à des pathologies telles que la dégénérescence maculaire liée à l’âge (DMLA) ou la rétinopathie diabétique (RD). Il semble qu’une alimentation riche en acides gras polyinsaturés à longue chaîne (AGPI-LC), notamment en oméga-3 comme l’EPA et le DHA, soit potentiellement protecteur vis-à-vis du développement de la DMLA et de l’insulinorésistance (IR), principal facteur de risque de la RD. Dans ce contexte, nous avons tenter d’évalué 1- l’impact de facteurs endogènes et environnementaux générateurs de stress oxydatif, de produits terminaux de glycation (PTG) ou d’insulinorésistance sur la fonction et le vieillissement de la rétine, et 2- l’adaptation de la rétine à un régime riche en AGPI-LC oméga-3 dans modèle murin de vieillissement de la rétine humaine, la souris ApoB100,LDLR-/-.Les animaux soumis à un stress oxydatif et à des PTG présentent une altération de la fonction rétinienne associée à une accumulation de cellules microgliales et/ou macrophages dans la rétine externe. L’IR induit une modulation de gènes impliqués dans le métabolisme des lipides, l’inflammation et dans la synthèse de facteurs nucléaires. Une alimentation riche en AGPI-LC oméga-3 induit une amélioration de l’incorporation d’acides gras oméga-3 dans la rétine et la modulation du gène codant le récepteur aux LDL dans la rétine neurosensorielle.En conclusion, nos travaux montrent une adaptation de la rétine d’une part à des conditions propices au vieillissement de la rétine et l’insulinorésistance, et d’autre part à un régime alimentaire riche en acides gras oméga-3 et pauvre en oméga-6, reconnu comme protecteur du vieillissement de la rétineWith advanced age, aging of the human retina can evolve into pathological forms, age-related macular degeneration (AMD) or diabetic retinopathy (DR). Meanwhile, epidemiological studies suggest that a diet rich in long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) such as EPA and DHA, potentially protects against the development of AMD and insulin resistance, the main risk factor for DR. Within this context, our research objectives were to assess: 1 - the impact of endogen and environmental factors, known to trigger oxidative stress, advanced glycation end-products (AGEs) or insulin resistance, on the function and aging of the retina, and 2 - the response of the retina to a omega-3 LC-PUFA-enriched diet in a murine model of aging of the human retina, the ApoB100,LDLR-/- mouse.The animals exposed to oxidative stress and AGEs showed an alteration of the retinal function associated with an accumulation of microglial cells and/or macrophages in the outer retina. The insulin resistance induced a modulation of the expression of genes coding proteins involved in lipid metabolism, inflammation and nuclear factors. An omega-3 LC-PUFA-enriched diet improved the incorporation of omega-3 LC-PUFA in the retina and modulated the expression of the LDL-receptor gene in the neurosensory retina.In conclusion, our works reported the adaptive response of the retina to environmental and endogenous factors known to promote aging of the retina. It included the impairment of the retinal function, and the modulation of gene expression. Our data also gave a better understanding of the effects of omega-3 LC-PUFA against aging of the retina
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Séité, Sarah. "Rôles de la méthionine sur le métabolisme hépatique de la truite arc-en-ciel (Oncorhynchus mykiss) : focus sur les mitochondries." Thesis, Pau, 2019. http://www.theses.fr/2019PAUU3007/document.
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L’impératif d’une aquaculture durable conduit à orienter l’alimentation des poissons vers la substitution de la farine de poisson par des produits végétaux renouvelables. Toutefois, ce remplacement est souvent limité par des niveaux trop faibles en méthionine dans les matières premières végétales. Ainsi la supplémentation en méthionine de ces nouveaux régimes à base de végétaux est essentielle, mais requière une bonne connaissance de son rôle pour adapter les apports aux conditions physiologiques des poissons tout en prenant en compte les contraintes économiques et environnementales de production. Dans ce contexte, cette thèse avait pour principal objectif de caractériser les effets induits par une carence en méthionine sur le métabolisme mitochondrial de la truite arc en ciel. Les résultats obtenus dans notre première étude montrent que l'alimentation de truites avec un régime déficient en méthionine entraîne une baisse des performances de croissance associée à une baisse de l’intégrité mitochondriale et une diminution du statut oxydatif dans le foie. Nous démontrons également que ces perturbations s’accompagnent de l’induction d’un processus de dégradation des mitochondries par autophagie (appelé mitophagie) ainsi que d’une augmentation du stress du Réticulum Endoplasmique (RE) et de l’apoptose. Ces données originales publiées dans le journal Scientific Reports mettent ainsi en évidence les liens étroits qui existent entre différentes fonctions cellulaires pour faire face à un déséquilibre nutritionnel en méthionine. Outre cet effet à court terme, nous démontrons également, dans un seconde étude, qu’une carence en méthionine alimentaire pendant une courte période (2 semaines) lors des premiers repas des alevins entraîne une induction à long terme de facteurs liés à la mitophagie. Ces résultats, soumis à publication dans Journal of Experimental Biology, démontrent ainsi pour la première fois la mise en place d’un processus de programmation de cette fonction cellulaire par une carence précoce en méthionine. L’enrichissement en H3K4me3 et H3K36me3 des foies des poissons issus d’alevins carencés en méthionine par rapport aux poissons témoins suggère une implication de mécanismes épigénétiques dans ces effets. Enfin, dans une troisième étude qui se détache de la thématique principale de la thèse et qui a fait l’objet d’une publication dans le journal Frontiers in Physiology, nous nous sommes attachés à préciser les interactions existante entre l’autophagie, l’homéostasie du RE et le métabolisme intermédiaire. Dans l’ensemble, ces données approfondissent notre compréhension du rôle de la méthionine alimentaire au niveau cellulaire et soulignent le potentiel de cet acide aminé en tant que levier pour appliquer de nouvelles stratégies alimentaires, comme la programmation nutritionnelle, afin d’optimiser la nutrition et la santé des poissons d'élevageThe expansion of the aquaculture industry in combination with limited availability and high prices of fishmeal has prompted feed producers to include more plant proteins in the aquaculture feeds. However, replacement of fish meal with plant proteins is often limited by the level of methionine in the alternative plant protein sources. Understanding of the different roles of methionine in fish is therefore essential to develop new diets and/or feeding strategies that are in tune with optimal fish growth, environmental and economic constraints. In this context, the main objective of this thesis was to characterize the effects induced by methionine deficiency on the hepatic mitochondrial metabolism in rainbow trout. The results obtained in our first study show that feeding trout with a methionine deficient diet leads to a decrease in growth performance associated with a decrease in both mitochondrial integrity and oxidative stress in the liver. We also demonstrate that these defects are accompanied by the induction of an autophagy-dependent mitochondrial degradation process (called mitophagy) as well as an increase in Endoplasmic Reticulum (ER)-stress and apoptosis. These original data published in Scientific Reports thus highlight the existence of close interactions between different cellular functions to cope to a dietary methionine deficiency. In addition to this short-term effect, we also demonstrate in a second study (submitted for publication in the Journal of Experimental Biology), that early nutritional stimulus during two weeks with a methionine deficient diet resulted in a long term programming of mitophagy. The enrichment of H3K4me3 and H3K36me3 in the liver of fish from methionine-deficient fry compared to their control counterparts suggests that epigenetic mechanisms are involved in these effects. Finally, in a third and last study, recently accepted for publication in Frontiers in Physiology, we sought to clarify, in primary culture of trout hepatocytes, the existing interactions between autophagy, ER homeostasis and intermediate metabolism under amino acid deprived conditions. Together, the results obtained in the present thesis extended our understanding of the role of dietary methionine at cellular level and emphasize the potential of this amino acid to apply new feeding strategies, such as nutritional programming, to optimize the nutrition and health of farmed fish