FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / A depressÃo à uma doenÃa crÃnica, grave que afeta cerca de 350 milhÃes de pessoas no mundo. O objetivo deste trabalho foi estudar os efeitos antidepressivos do Ãcido lipÃico (ALA) associado a mirtazapina (MIRT) via mecanismos antioxidativos em modelo animal de depressÃo induzido por corticosterona. Camundongos machos adultos receberam 0,3% Tween 80, Corticosterona (CORT 20 mg/kg), MIRT (3 mg/kg), ALA (100 ou 200 mg/kg), sozinhos ou associados por 21 dias. No Ãltimo dia de tratamento os animais foram submetidos aos seguintes testes: campo aberto, labirinto em cruz elevado, suspensÃo de cauda, preferÃncia por sacarose, rota rod e tempo de sono. AlteraÃÃes oxidativas (glutationa reduzida-GSH e peroxidaÃÃo lipÃdica- MDA) e nitrito no cÃrtex prÃ-frontal (CPF), hipocampo (HC) e corpo estriado (CE); e fator neurotrÃfico derivado do cÃrebro (BDNF) no CPF e HC tambÃm foram abordadas. A administraÃÃo crÃnica de CORT desenvolveu alguns comportamentos tipo-depressivos que foram revertidos com MIRT e/ou ALA. A associaÃÃo de ALA e MIRT reverteu o efeito sedativo provocado pela administraÃÃo de MIRT sozinha, assim como a hipersonia causada pela administraÃÃo crÃnica de CORT. A administraÃÃo de CORT, ALA 200 e MIRT associados mostrou um aumento significativos nos nÃveis de GSH no cÃrtex prÃ-frontal (113%), hipocampo (90,27%) e corpo estriado (127%) quando comparado com o grupo tratado com CORT sozinha; efeitos semelhantes foram observados na peroxidaÃÃo lipÃdica e nos nÃveis de nitrito, com reduÃÃo dos nÃveis de MDA e nitrito no hipocampo e corpo estriado dos grupos tratados com a associaÃÃo de CORT, ALA 200 e MIRT quando comparados com o grupo tratado com CORT sozinha, respectivamente. No geral, ALA parece ser uma alternativa para o tratamento da depressÃo quando associado com MIRT, pois aumenta a neuroproteÃÃo e reduz o efeito colateral de sedaÃÃo. / Depression is a chronic, serious illness that affects about 350 million people worldwide. The objective of this work was to study the antidepressant effects of lipoic acid (ALA) associated with mirtazapine (MIRT) via antioxidative mechanisms in animal models of depression induced by corticosterone. Adult male mice received 0.3% Tween 80, corticosterone (Cort 20 mg / kg) MIRT (3 mg / kg), ALA (100 or 200 mg / kg), alone or associated for 21 days. On the last day of treatment the animals were subjected to the following tests: open field, elevated plus maze, tail suspension, preference for sucrose, route rod and sleep time. Oxidative changes (reduced glutathione and GSH-peroxidation lipÃdica- MDA) and nitrite in the prefrontal cortex (PFC), hippocampus (HC) and striatum (CE); and brain-derived neurotrophic factor (BDNF) in the CPF and HC were also addressed. Chronic administration of CORT developed some kind-depressive behaviors were reversed with MIRT and / or ALA. The association of ALA and MIRT reversed the sedative effect caused by the administration alone MIRT, as hypersomnia caused by the chronic administration of CORT. The administration CORT ALA 200 and associated MIRT showed significant increase in GSH levels in the prefrontal cortex (113%), hippocampus (90.27%) and striatum (127%) compared to the group treated with CORT alone; Similar effects were observed on lipid peroxidation and nitrite levels with reduction of MDA and nitrite levels in the hippocampus and striatum in the groups treated with the combination CORT ALA MIRT 200 and compared with the group treated with CORT alone respectively. Overall, ALA seems to be an alternative for treatment of depression associated with MIRT when, for neuroprotection increases and reduces the side effect of sedation.

Les sources secondaires de métaux précieux, tels que les déchets électroniques, ont récemment attiré l’attention générale suite à la sensibilisation sur l’épuissement des ressources naturelles et sur l’industrie du recyclage sur l’emploi et la croissance économique. Developper des technologies de recyclage qui permettent l’extraction de palladium (Pd) et d’or (Au) en très faibles concentrations (10-100 ppm) dans les effluents électroniques s’avère aujourd’hui économiqueemnt viable.Dans ce contexte, notre étude aborde l’utilisation de nanoparticules de ZrO2 modifiées avec des ligands complexants en surface pour capturer efficacement et sélectivement des ions Pd(II) et Au(III) dan les effluents électroniques. Les avantages de l’utilisation de acide thioctique commercial (TOA) par rapport aux acides dialkyldiglycoamide ou (N, N)-dialkylcarbamoylméthylphosphoniques en termes de capacité d’adsorption et de sélectivité ont été démontrés. Des expériences d’adsorption en mode batch combinées à la méthode ICP-OES ont été réalisées et nos résultats ont montré des capacités d’adsorption envers le Pd et l’Au de 6.3 mg/g et de 43 mg/g, respectivement. Les processus d’adsorption suivaient le modèle de Langmuir et les cinétiques chimiques d’adsorption étaient mieux adaptés à l’équation du pseudo-second ordre. Les conditions d’optimisation pour la mise en place du stripping sélectif à l’aide de solutions acidifiées de thiourée ont également été étudiées. En particulier, afin d’améliorer la réutilisation de ce matériau hybride, des processus de modification des surface en deux étapes ont été développés par fonctionnalisation de la surface de nano-ZrO2 avec de l’acide alendronique et par une réaction de couplage peptidique avec du TOA.De plus, les procédés de greffage de nano-ZrO2 sur un textile en polypropylène modifié avec les groupements carboxylique ont été étudiés via des méthodes traditionnelles de revêtement par immersion (dip-coating) et de revêtement couche par couche (LbL). Cette dernière s’est avérée être une méthode prometteuse en termes de flexibilité, de facilité de manipulation et de respect de l’environnment. Les nanocomposites obtenus ont démontré d’excellentes propriétés d’adsorption de Pd et d’Au / Secondary sources of precious metals, such as e-waste, have been recently gaining more attention thanks to raising awareness of natural resources depletion and sound impact of recycling industry on employment and economic growth. Recycling technologies have now to be developed, enabling extraction of very small concentration (10-100 ppm) of precious metals, such as palladium (Pd) and gold (Au), from effluents of recycling factories economically viable.In this context, our study addresses the use of thioctic surface-modified zirconia nanoparticles to capture efficiently and selectively Pd(II) and Au(III) ions from industrial electronic wastewater. The advantages of using the commercial thioctic acid (TOA) over dialkyldiglycoamide or (N,N)-dialkylcarbamoylmethylphosphonic acids ones in terms of adsorption capacity and selectivity were demonstrated. Batch-mode adsorption experiments combined with ICP-OES method were conducted and our findings have displayed adsorption capacities toward Pd and Au of 6.3 mg/g and 43.3 mg/g, respectively. The adsorption processes were found to follow the Langmuir model and adsorption rates were best-fitted to pseudo-second order equation. The optimization conditions for selective stripping set-up using acidified solutions of thiourea were also investigated. Particularly, in order to improve the reusability of this hybrid nanomaterial, two-step surface modification processes were developed through alendronic acid-surface functionalization of nano-ZrO2 and amide coupling reaction with TOA.Furthermore, the grafting processes of nano-ZrO2 onto carboxylic-modified polypropylene textile were studied via traditional dip-coating and layer-by-layer coating methods. It has been realized that layer-by-layer coating method is a promising method in terms of its flexibility, ease of handling, and environmental friendliness

The objective of this study was to examine the effects of a medium chain triglyceride oil mixture (MCTo), designed to increase energy expenditure and improve lipid profiles containing medium chain triglycerides, phytosterols and n-3 fatty acids in the form of flaxseed oil, versus the antioxidant alpha-lipoic acid (ALA). Forty-eight hamsters were fed (i) hypercholesterol emic (HC) control, (ii) HC MCTo, (iii) HC ALA, (iv) HC MCTo/ALA diets for 4 weeks. No effects on food intake, body weight, total body water, lean body mass, fat mass, and tissue thiobarbituric acid-reactive substances (TBARS) were observed. ALA alone had no effect on total cholesterol (TC); however, MCTo feeding increased TC with (p < 0.03) and without (p < 0.003) ALA when compared to control. ALA increased HDL levels compared to control (p 0.04) and MCTo/ALA (p < 0.007) groups. MCTo, with (p < 0.0001) or without (p < 0.006) ALA, increased non-HDL cholesterol levels versus control. The non-HDL:HDL ratio was decreased by ALA compared to MCTo (45%) and MCTo/ALA (68%) (p < 0.0001), a similar trend was seen when compared to the HC control (22%) group (p < 0.14). Triglyceride levels were not altered by any of the dietary treatments. Liver and heart tissue reduced glutathione (GSH) was increased (p < 0.05) by all three treatments when compared to control. Both tissues showed an increase (p < 0.05) in oxidized glutathione (GSSG) when fed ALA compared to all other treatments. Hamsters fed ALA had a lower (p < 0.05) GSH/GSSG ratio compared to all treatment groups. In conclusion, MCTo feeding does not elicit beneficial effects on circulating plasma lipids and measures of body composition. In addition, our results do not clearly support an improvement in oxidative status through supplementation of ALA. However, our results do support the existence of beneficial effects of ALA on circulating lipoprotein content in the hamster.

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2003. / Vita. Bibliography: References located at the end of each chapter.

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