Cadmium is heavy metal toxic for plants and animals and environmental contaminant which must be removed from natural environment. In recent years a new method phytoremediation is getting more attention. This method uses plants called hyperaccumulators for extraction of heavy metals from soils. Hyperaccumulators have, however, after accumulation of heavy metals no other use. Therefore new possibilities are discussed in last few years. Energy plants, in this thesis sorghum and malva, could be used for accumulation of heavy metals from soils and after that these plants could be used as energy source. This thesis wants to find out if sorgum and malva are able to grow in cadmium contaminated environment and if these plants will accumulate cadmium. It also compares different cultivars of sorghum in toxicity tests and compares ability of these cultivars to grow in cadmium contaminated environment and to accumulate this heavy metal. Further it focuses on affection of uptake of kadmium ions by sorhum in presence of glutathione or ethylenediaminetetraacetic acid.

Glutathione (GSH) is a small antioxidant in the body and exists in large quantities compared to other antioxidants. The GSH redox state (Eh) helps developmental processes, however, when the GSH Eh is disrupted, cells may undergo significantly poor developmental pathways, possibly leading to long-lasting damages. Similarly, NADPH and Thioredoxin redox states can have a major impact on cellular function, viability, and response to both endogenous and exogenous toxicants. Subcellular, compartmentalized redox environments during normal or perturbed situations, specifically in the cytosol, mitochondria, and nucleus, are not well understood. Here, using the P19 neurogenesis model of cellular differentiation, the kinetics of subcellular H2O2 availability and GSH/GSSG and NADPH/NADP+ redox shifts were evaluated following oxidant exposure. Additionally, modified mouse embryonic fibroblasts (MEFs) were used to observe redox changes and protective mechanisms when major antioxidative pathways are inhibited, mainly those involving the GSH/GSSG and Trxred/Trxox pathways. Overall, treated undifferentiated cells showed a greater degree and duration of both H2O2 availability and GSH/GSSG and NADPH/NADP+ disruption throughout all compartments than differentiated neurons. Pretreatment with an Nrf2 inducer prevented H2O2-induced effects in all compartments of undifferentiated cells. Additionally, MEF cells without either GSH or Trx showed a greater degree and duration of GSH/GSSG and Trxred/Trxox disruption throughout the cytosol and nucleus when compared to normal functioning cells. Disruption of redox-sensitive developmental pathways is likely stage-specific, where cells that are less differentiated and/or are actively differentiating are most affected. Undifferentiated cells are more susceptible to oxidant-induced redox dysregulation but are protected through prior Nrf2 induction, which appears to preserve developmental programs and diminish the potential for poor developmental outcomes. The GSH and Trx antioxidant pathways converge to protect the cell, while cells that are missing one pathway or the other may undergo damaging developmental outcomes.

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Résumé L’objectif de cette étude était de déterminer les effets de la source de sélénium sur les concentrations de Se et de GSH-Px des vaches de boucherie (n =33) et leurs veaux et sur des paramètres immunitaires des veaux. Deux groupes de vaches ont reçu 3 mg/j/animal de Se organique ou inorganique dans le minéral. Le troisième groupe n'a pas été supplémenté en Se et leurs veaux ont été divisés en deux sous-groupes, l’un des deux a reçu une injection de sélénite de sodium (0,087 mg/Kg) à la naissance. Le Se et la GSH-Px ont été respectivement mesurés par HPLC-UV et par cinétique enzymatique. La phagocytose, la flambée respiratoire et le ratio CD4:CD8ont été évalués par des kits commerciaux et les IgG totales ont été mesurés par immunodiffusion radiale. La supplémentation de Se a augmenté significativement le Se sérique et colostral (P<0,02) et la GSH-Px(P≤0,04) pour les vaches et leurs veaux avec un effet significativement plus élevé pour le Se organique. Le Se du lait a augmenté de façon significative uniquement avec la source organique du Se (P≤0,0007). L’injection du Se chez les veaux a permis une augmentation significative mais temporaire (P<0,0001) du Se sérique. La supplémentation en Se n’a pas influencé les paramètres immunitaires mesurés (P>0,01, non significatif après correction de Bonferroni). Nous concluons que la supplémentation en Se améliore le niveau du Se colostral, lacté et sérique ainsi que la GSH-Px pour les vaches et leurs veaux sans effet sur les paramètres immunitaires mesurés des veaux. Mots clés: Sélénium, veaux de boucherie, phagocytose, flambée respiratoire, anticorps, ratio CD4:CD8, GSH-Px. / Abstract The aims of this study were to determine the effects of selenium (Se) supplementation sources (organic and inorganic) on Se and GSH-Px concentrations of beef cows (n=33) and their calves and on immune parameters of the calves. Two groups of cows were given daily 3 mg of either organic or inorganic Se in mineral supplement starting from 12 weeks before calving until weaning. The third group had no Se added into the diet and their calves were divided into two subgroups either injected or not with 0.087 mg/kg of sodium selenite after birth. Serum Se and whole blood GSH-Px were respectively measured by HPLC-UV and by kinetic-enzymatic technique. Calves immune parameters were evaluated using commercial kits for phagocytosis, respiratory burst and CD4:CD8 ratio and radial immunodiffusion for total IgG concentrations. In cows and calves, Se supplementation increased significantly serum and colostrum Se concentrations (P<.02) with significant higher effect for organic source. However, milk Se concentrations increased significantly only with the organic source (P≤.0007). Se supplementation increased GSH-Px concentrations in cows (P≤.04) and their calves (P≤.0004); organic source induced a higher effect than inorganic one in calves (P≤.0004). Se injection in calves allowed a temporary increase (P<.0001) of serum Se concentrations. No significant differences were noticed throughout the experiment for all of the immune parameters measured (P>.01, not significant after Bonferroni adjustment). Our results showed that Se supplementation improved colostrum, milk and serum Se and GSH-Px concentrations in cows and their calves without effect on the measured immune parameters in calves. Key words: selenium, beef calves, phagocytosis, respiratory burst, antibodies, CD4:CD8 ratio, GSH-Px.

Résumé L’objectif de cette étude était de déterminer les effets de la source de sélénium sur les concentrations de Se et de GSH-Px des vaches de boucherie (n =33) et leurs veaux et sur des paramètres immunitaires des veaux. Deux groupes de vaches ont reçu 3 mg/j/animal de Se organique ou inorganique dans le minéral. Le troisième groupe n'a pas été supplémenté en Se et leurs veaux ont été divisés en deux sous-groupes, l’un des deux a reçu une injection de sélénite de sodium (0,087 mg/Kg) à la naissance. Le Se et la GSH-Px ont été respectivement mesurés par HPLC-UV et par cinétique enzymatique. La phagocytose, la flambée respiratoire et le ratio CD4:CD8ont été évalués par des kits commerciaux et les IgG totales ont été mesurés par immunodiffusion radiale. La supplémentation de Se a augmenté significativement le Se sérique et colostral (P<0,02) et la GSH-Px(P≤0,04) pour les vaches et leurs veaux avec un effet significativement plus élevé pour le Se organique. Le Se du lait a augmenté de façon significative uniquement avec la source organique du Se (P≤0,0007). L’injection du Se chez les veaux a permis une augmentation significative mais temporaire (P<0,0001) du Se sérique. La supplémentation en Se n’a pas influencé les paramètres immunitaires mesurés (P>0,01, non significatif après correction de Bonferroni). Nous concluons que la supplémentation en Se améliore le niveau du Se colostral, lacté et sérique ainsi que la GSH-Px pour les vaches et leurs veaux sans effet sur les paramètres immunitaires mesurés des veaux. Mots clés: Sélénium, veaux de boucherie, phagocytose, flambée respiratoire, anticorps, ratio CD4:CD8, GSH-Px. / Abstract The aims of this study were to determine the effects of selenium (Se) supplementation sources (organic and inorganic) on Se and GSH-Px concentrations of beef cows (n=33) and their calves and on immune parameters of the calves. Two groups of cows were given daily 3 mg of either organic or inorganic Se in mineral supplement starting from 12 weeks before calving until weaning. The third group had no Se added into the diet and their calves were divided into two subgroups either injected or not with 0.087 mg/kg of sodium selenite after birth. Serum Se and whole blood GSH-Px were respectively measured by HPLC-UV and by kinetic-enzymatic technique. Calves immune parameters were evaluated using commercial kits for phagocytosis, respiratory burst and CD4:CD8 ratio and radial immunodiffusion for total IgG concentrations. In cows and calves, Se supplementation increased significantly serum and colostrum Se concentrations (P<.02) with significant higher effect for organic source. However, milk Se concentrations increased significantly only with the organic source (P≤.0007). Se supplementation increased GSH-Px concentrations in cows (P≤.04) and their calves (P≤.0004); organic source induced a higher effect than inorganic one in calves (P≤.0004). Se injection in calves allowed a temporary increase (P<.0001) of serum Se concentrations. No significant differences were noticed throughout the experiment for all of the immune parameters measured (P>.01, not significant after Bonferroni adjustment). Our results showed that Se supplementation improved colostrum, milk and serum Se and GSH-Px concentrations in cows and their calves without effect on the measured immune parameters in calves. Key words: selenium, beef calves, phagocytosis, respiratory burst, antibodies, CD4:CD8 ratio, GSH-Px.

[pt] Uma das formas de detectar a contaminação ambiental é pela análise de respostas bioquímicas, ou biomarcadores, de tecidos de organismos-sentinela, como os mamíferos marinhos, uma vez que estes atuam como bioindicadores da saúde dos oceanos e de suas respectivas cadeias tróficas. A toninha (Pontoporia blainvilei) e o golfinho-de-dentes-rugosos (Steno bredanensis) são animais com longa expectativa de vida e estão no topo da cadeia alimentar, sendo, portanto, considerados indicadores adequados de contaminação ambiental. Neste trabalho foram estudadas as concentrações de metais e metalóides, tanto não-essenciais quanto essenciais, em amostras de fígado, rim e músculo de indivíduos de P. blainvilei e S. bredanensis coletados na Região dos Lagos e Norte Fluminense do estado do Rio de Janeiro, através da técnica de espectrometria de massas com plasma indutivamente acoplado (ICP-MS). Além das concentrações totais, foram avaliados como estes se distribuem nas diferentes frações subcelulares, obtidas a partir de processos de extração diferencial. Além disso, foi avaliada também a indução de metalotioneína (MT) e glutationa reduzida (GSH), consideradas proteínas de resposta a este tipo de contaminação, por espectrofotometria na região do UV-visível. Não houve diferença significativa entre as concentrações de MT encontradas nos três tecidos analisados para ambas as espécies, nem para GSH em P. blainvilei. No entanto, foi verificada uma diferença significativa entre GSH de fígado e músculo em S. bredanensis. Como esperado, a concentração no fígado foi mais elevada, por este ser um órgão metabolicamente ativo, além do principal órgão de destoxificação. Em P. blainvilei, elementos como Al, As, Cd, Cr, Mn, Pb e Ti, apresentaram altas concentrações nas frações termolábil e termoestável de todos os tecidos avaliados, indicando que grande parte destes analitos está sendo destoxificado por complexação com MT ou outras proteínas e compostos não enzimáticos. Outros elementos, como Ag, Cu, Fe, Hg, Ni, Se, Sn e Zn, embora presentes nos indivíduos, apresentaram a maior parte de sua concentração na fração insolúvel, indicando que, provavelmente, as vias preferenciais de destoxificação destes elementos nesta espécie não sejam realizadas através de MT. Em S. bredanensis, os metais Al e Cr também foram encontrados majoritariamente na fração insolúvel. Com relação às concentrações totais desses metais, níveis elevados para a maioria dos analitos foram observados em fígado, rim e músculo na espécie S. bredanensis. Diversas correlações estatisticamente significativas foram observadas entre elementos não-essenciais e essenciais em todas as frações subcelulares, no fígado e músculo de ambas espécies, através de uma análise de componentes principais. Além disso, alguns efeitos protetivos foram postulados contra elementos não-essenciais, avaliados a partir de cálculos de razões molares. Diferentes perfis foram observados para metaloproteínas contidas na fração termoestável destes indivíduos, através da técnica de cromatografia de alta eficiência acoplada a ICP-MS (HPLC-ICP-MS), indicando acúmulo dos metais e metalóides nos tecidos analisados, possível perturbação da homeostase dos elementos essenciais e tentativas de desintoxicação de metais não-essenciais por diversas metaloproteínas. / [en] One of the ways to detect environmental contamination is by analyzing biochemical responses, or biomarkers, in sentinel species tissues, such as marine mammals, as these animals act as bioindicators of ocean health and their respective trophic chains. Porpoises (Pontoporia blainvilei) and rough-toothed dolphins (Steno bredanensis) present long-life expectancy and are at the top of the food chain and are, therefore, considered appropriate environmental contamination indicators. In this study, environmental contamination by metals and metalloids, both non essential and essential, was assessed by means of inductively coupled plasma mass spectrometry (ICP-MS), as well as their distribution in different subcellular fractions, obtained from differential extraction processes analysis, in P. blainvilei and S. bredanensis liver, kidney and muscle samples of individuals sampled from in the Lakes and Northern Fluminense regions, in the state of Rio de Janeiro. In addition, the induction of both metallothionein (MT) and reduced glutathione (GSH) considered response proteins to this type of contamination, were also assessed by spectrophotometry in the UV-visible region. No significant difference between MT concentrations in the three analyzed tissues were noted for both species. This was also observed for GSH in P. blainvilei. However, a significant difference was observed between liver and muscle GSH in S. bredanensis, and, as expected, liver concentrations were higher as this is a metabolically active and main detoxification organ. In P. blainvilei, metals like as Al, As, Cd, Cr, Mn, Pb e Ti were present in high concentrations in the thermolabile and thermostable fractions of all evaluated tissues, indicating that a significant portion of these analytes is being detoxified by complexation with MT or other proteins and non-enzymatic compounds. Some metals, such as Ag, Cu, Fe, Hg, Ni, Se, Sn e Zn although detected, were present mostly in the insoluble fraction, indicating that the preferred detoxification pathways of these elements in this species are probably not performed through MT. In S. bredanensis, Al and Cr were also detected in the insoluble fraction. Regarding the total concentrations of these metals, high levels for most analytes were observed in S. bredanensis liver, kidney and muscle. Several statistically significant correlations between toxic and essential elements were observed in the liver and muscle of both species for all subcellular fractions, through a principal component analysis. In addition, some protective effects were postulated against toxic elements, evaluated from molar ratios calculations. Different profiles were observed for metalloproteins contained in the thermostable fraction of these individuals, using high efficiency chromatography coupled to ICP-MS (HPLC- ICP-MS), indicating metal and metalloid accumulation in the analyzed tissues, possible disturbance of elemental homeostasis and attempts to detoxify toxic metals by several metalloproteins.

Compartmentalization of redox reactions is essential to all life forms. Protein activity can respond to changes in the local redox environment through the reversible oxidation of cysteine thiols. For the majority of cysteines in the proteome, this interaction takes place through equilibration with the glutathione pool; this raises the question whether this redox pool acts as a buffer, or instead as a sensitive media, transducing information from a local physiological state into protein function.

La plupart des matériaux pour l'ONL quadratique actuellement commercialisés sont utilisés pour des applications dans le domaine de l'UV au proche infrarouge. Cependant, l'atmosphère présente deux autres fenêtres de transparence dans l'infrarouge : fenêtre II entre 3 et 5 Μm et fenêtre III entre 8 et 12 Μm. Les matériaux susceptibles de couvrir les besoins pour les applications entre 4 Μm et 12 Μm sont peu nombreux. Les composés d'iodates anhydres étudiés dans ce travail de formule générale M(IO3)n ou MM'(IO3)4 sont synthétisés soit par lente évaporation dans l'acide nitrique concentré soit en synthèse hydrothermale. Les études structurales menées par diffraction des rayons X sur poudre et sur monocristal, mettent en évidence une analogie entre les composés M(IO3)2, M(IO3)3 et a-LiIO3 qui permet l'obtention de solutions solides. Les composés étudiés présentent trois caractéristiques communes importantes : grande stabilité thermique en moyenne 500°C, non hygroscopicité et très grande fenêtre de transparence qui s'étend en continue de l'UV, pour les composés incolores, vers l'infrarouge lointain en moyenne jusqu'à 13 Μm. De plus, ils présentent un seuil de dommage optique sur poudre de l'ordre de quelques GW.cm-2 et l'efficacité en doublement de fréquence est comparable voire supérieure à celle observée pour a-LiIO3. Par ailleurs, l'insertion d'éléments luminescents a pu être réalisée dans certaines de ces matrices. Nous disposons maintenant de toute une famille de matériaux potentiellement actifs (émission laser due à la présence d'éléments luminescents pour les lasers à longueurs d'ondes fixes ou accordables) et/ou passifs (doubleur de fréquence) qui pourraient répondre aux exigences requises pour les applications visées.

Un effort de recherche important concerne le développement de nouvelles solutions pour la génération de second harmonique dans des guides d'ondes, généralement réalisés par implantation ou par échange d'ions sur des substrats monocristallins optiquement<br />non-linéaires.<br />Dans la première partie de ce travail, nous avons utilisé l'échange de protons pour réaliser des guides d'ondes sur des substrats d'iodate de lithium, matériau largement utilisé<br />pour des applications en optique non-linéaire quadratique. Des guides d'ondes présentant une atténuation inférieure à 1 dB/cm ont été obtenus et nous avons montré, par une étude combinée en diffraction des rayons X, spectroscopie Raman et spectroscopie mlines, que la couche guidante était constituée de solution solide Li(1−x)HxIO3 dont l'indice de réfraction est proportionnel à la concentration en protons (x). Nous avons également caractérisé la cinétique du processus d'échange. Cependant, les coeffcients de diffusion élevés à température ambiante ne permettent pas l'obtention de guides stables dans des conditions standard d'utilisation.<br />Tout en gardant comme objectif la réalisation de guides d'ondes pour l'optique nonlinéaire, nous avons abandonné l'utilisation de LiIO3 monocristallin pour l'insérer sous la forme de nanocristaux dans des matrices vitreuses. Ainsi, deux types de nanocomposites<br />ont été étudiés, l'un constitué d'une matrice de silice élaborée par voie sol-gel, l'autre constitué d'une matrice de Laponite, une argile synthétique très bas coût. Pour chacun des composites, une étude structurale a permis de déterminer la cinétique de cristallisation de LiIO3 dont les cristaux ont pu être orientés par l'application d'un champ électrique durant la nucléation.<br />Enfin, pour le composite LiIO3/Laponite, des guides d'ondes ont été élaborés et une atténuation de l'ordre de 2 dB/cm a été mesurée. Nous avons mesuré un coeffcient nonlinéaire effectif de l'ordre de 1.6 pm/V pour un composite dopé à 50% vol. et un modèle<br />a été proposé pour décrire le comportement optique non-linéaire du matériau. Ce modèle a ensuite permis de simuler les performances de structures périodiquement orientées.

No description available.