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Made available in DSpace on 2014-10-09T12:30:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:26Z (GMT). No. of bitstreams: 1 01387.pdf: 2053886 bytes, checksum: 9c61b3e10e5af0bb9a9a9cb8707260c7 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

O presente trabalho teve como objetivo avaliar, por meio da microscopia eletrônica de varredura (MEV), a capacidade de remoção da smear layer dos terços médio e apical do canal radicular utilizando soluções quelantes e desmineralizantes e, quantificar, por meio da espectrometria de absorção atômica com chama, a concentração de íons cálcio presentes nessas soluções após suas utilizações. Vinte e cinco caninos superiores foram preparados pela técnica Free Tip Preparation com 4 instrumentos acima do inicial e irrigados com hipoclorito de sódio 1% a cada troca de instrumento. Os dentes foram distribuídos aleatoriamente em 4 grupos, conforme protocolo utilizado para a irrigação final: G1 - EDTA 15%, G2 - quitosana 0,2%, G3 - ácido cítrico 10%, G4 - ácido acético 1%. O grupo controle (G5) não recebeu irrigação. Foram utilizados 5 mL de cada solução por 3 minutos. Após percorrer toda extensão do canal radicular a solução extravasada pelo forame foi coletada e encaminhada para análise espectrométrica. Os espécimes foram seccionados longitudinalmente e preparados para análise em MEV. As fotomicrografias obtidas foram avaliadas qualitativamente por três examinadores, que atribuíram escores às imagens, conforme a quantidade de smear layer. Os dados obtidos pela MEV foram analisados estatisticamente por meio do Teste de Kruskal-Wallis e Dunn. Para avaliação da espectrometria utilizou-se Tukey-Kramer (one-Way ANOVA). Os resultados mostraram que o EDTA 15%, quitosana 0,2% e ácido cítrico 10% removeram a smear layer de forma semelhante entre si e estatisticamente diferente (p<0,05) do ácido ácético 1% e controle. Não houve diferença na capacidade de limpeza das soluções quando os terços médio e apical foram comparados. A maior concentração de íons cálcio foi observada no grupo do EDTA 15% e quitosana 0,2%, sem diferença entre ambos. O grupo do ácido acético 1% apresentou as menores concentrações e o ácido cítrico 10%, concentrações intermediárias e diferentes estatísticamente dos dois grupos (p<0,01). Concluiu-se que as soluções de EDTA 15%, quitosana 0,2% e ácido cítrico 10% foram eficientes na remoção da smear layer do terço médio e apical do canal radicular. As soluções de EDTA 15% e quitosana 0,2% promoveram o maior efeito desmineralizante, seguidas pelo ácido cítrico 10% e acido acético 1%. / This study aimed to evaluate, by scanning electron microscopy (SEM), the ability to remove the smear layer from the apical and middle thirds of the root canal using chelators and demineralizing solutions, and quantify, by atomic absorption spectrophotometry flame, the concentration of calcium ions present in these solutions after their use. Twenty-five canines were prepared by Free Tip Preparation Technique with four instruments above the initial and irrigated with 1% sodium hypochlorite in each change of instrument. The teeth were randomly divided into four groups, according to the protocol used for the final irrigation: G1 - EDTA 15%, G2 - 0.2% chitosan, G3 - citric acid 10%, G4 - 1% acetic acid. The control group (G5) did not receive irrigation. We used 5 mL of each solution for 3 minutes. After irrigating the entire length of the root canal through the apical foramen, the solution was collected and sent to spectrometric analysis. The specimens were sectioned longitudinally and prepared for SEM analysis. The photomicrographs were qualitatively evaluated by three observers, who attributed scores to the images, equivalent to the amount of smear layer removal. The data obtained by SEM was statistically analyzed using the Kruskal-Wallis and Dunn tests. To evaluate the spectrometer, the Tukey-Kramer (one-way ANOVA) was used. The results showed that 15% EDTA, 0.2% chitosan and 10% citric acid had a similar smear layer removal with statistically different (p <0.05) when compared to 1% acetic acid and the control group. There was no difference between the solutions cleaning ability when the middle and apical thirds were compared. The highest concentration of calcium ions was observed in 15% EDTA group and 0.2% chitosan, with no statistical difference between them. The 1% acetic acid group had the lowest concentration and the 10% citric acid intermediate concentrations with statistical difference between each other (p <0.01). It can be concluded that the solutions of 15% EDTA, 0.2% chitosan and 10% citric acid were effective in removing the smear layer of the middle and apical thirds of the root canal. 15% EDTA solutions and 0.2% chitosan promoted the greatest effect on the demineralization, followed by 10% citric acid and 1% acetic acid.

INTRODUÇÃO: Há poucos modelos experimentais de doença óssea adinâmica (DOA) e os mecanismos fisiopatológicos dessa doença não são completamente compreendidos. Além disso, os efeitos dos quelantes de fósforo (P) na DOA têm sido pouco estudados. Este estudo objetivou estabelecer um modelo de DOA e avaliar os efeitos da terapia com carbonato de cálcio (Ca) e carbonato de sevelamer (sevelamer) sobre os distúrbios do metabolismo mineral e ósseo da doença renal crônica (DMO-DRC), no modelo estabelecido. MÉTODOS: Experimento 1: A DOA e a DRC foram induzidas por nefrectomia 5/6 (Nx) e paratireoidectomia (PTx) em ratos Wistar, que após a cirurgia foram divididos em 2 grupos: Nx+PTx e sham (sham Nx+PTx). Experimento 2: ratos Wistar foram submetidos à Nx e à PTx e após a cirurgia, foram divididos em outros 2 grupos: Nx+PTx+Ca (CaCO3 a 3%); Nx+PTx+Sev (sevelamer a 3%). A dieta de todos os animais após a cirurgia foi rica em P (1,2%) à base de grãos, exceto o grupo sham, que recebeu dieta padrão com 0,6% de P. Após oito semanas, os animais foram sacrificados. Foram realizadas análises bioquímicas, ósseas e de calcificação vascular. RESULTADOS: Experimento 1: A Nx e a PTx foram efetivas, confirmadas pela elevação da creatinina, com diminuição do clearance de creatinina e dos níveis de cálcio iônico, nos animais Nx+PTx comparados aos animais sham. O modelo foi eficaz na indução da DOA, confirmada pela diminuição do turnover ósseo nos animais Nx+PTx, comparados ao grupo sham. Experimento 2: A terapia com quelantes de P não alterou o P sérico, mas reduziu a fração de excreção de P (FeP). A diminuição dos níveis de FGF-23 e PTH nos animais Nx+PTx foram independentes da terapia com quelantes e não houve diferença nos valores entre os grupos. A esclerostina sérica não foi diferente entre os grupos, mas os animais Nx+PTx+Sev apresentaram menor expressão gênica de SOST e menor taxa de apoptose de osteócitos que os outros grupos. Ambos os quelantes de P diminuíram a expressão gênica do Dickkopf-1 e do fator de crescimento ?1 (TGF-?1). Os animais Nx+PTx+Ca apresentaram maior superficie de reabsorção e maior conteúdo de Ca do ventrículo esquerdo (VE) que os animais Nx+PTx, enquanto os animais Nx+PTx+Sev mostraram diminuição do conteúdo de Ca de VE, comparado aos demais grupos. CONCLUSÕES: o modelo experimental desenvolvido é útil para o estudo da DRC com DOA. A FeP parece ser parâmetro mais fidedigno que o P sérico para avaliar o poder dos quelantes de P. A diminuição do FGF-23 esteve relacionada à diminuição dos níveis de PTH e à hipocalcemia. Os animais tratados com Ca apresentaram sobrecarga desse elemento, traduzida por maior calciúria, maior conteúdo de cálcio de VE e maior superfície de reabsorção óssea. Os mecanismos subjacentes à ação do sevelamer na diminuição da expressão da SOST foram independentes do PTH, do P séricos, da função renal e da expressão gênica de TGF-?1. Mais estudos são necessários para melhor compreensão desses mecanismos / INTRODUCTION: There are few experimental models of adynamic bone disease (ABD) and the pathophysiology of this disease is not fully understood. In addition, the effects of different phosphate (P) binders on ABD have not been evaluated. This study aimed to establish a model of ABD and evaluate the effects of therapy with calcium carbonate (Ca) and sevelamer carbonate (sevelamer) on disorders of bone and mineral metabolism in chronic kidney disease (CKD-MBD), on the established model. METHODS: Experiment 1: ABD and CKD were induced by 5/6 nephrectomy (Nx) and parathyroidectomy (PTx) in Wistar rats, which after surgery, were divided into 2 groups: Nx+PTx and sham (sham Nx+PTx). Experiment 2: Wistar rats underwent Nx and PTx and after surgery were divided into 2 more groups: Nx+PTx+Ca(3% Ca-treated) and Nx+PTx+Sev (3% Sev-treated). All animals were fed a high P (1.2%), grain-based diet, except the sham group which was fed a standard P (0,6%) diet. After 8 weeks, the animals were sacrificed. Biochemical, bone and vascular calcification analyses were performed. RESULTS: Experiment 1: Nx and PTx were effective, confirmed by higher creatinina with decreased creatinine clearance and decreased ionized calcium levels respectively, in Nx+PTx animals compared to sham animals. The model was effective in inducing ABD confirmed by decreased bone turnover in animals Nx+PTx compared to sham group. Phosphate binders administration did not change serum P, but decreased the fractional excretion of phosphate (FeP) in treated animals. FGF-23 and PTH levels were reduced in all Nx+PTx animals independent of the therapy with P binders and these levels were not different among groups. Serum sclerostin was not different among groups, however, Nx+PTx+Sev animals had lower SOST gene expression and lower osteocytes apoptotic rate than the other animals. Both P binders decreased Dickkopf-1 and transforming growing factor ?1 (TGF-?1) gene expression. Nx+PTx+Ca animals showed higher eroded surface and higher left ventricle (LV) calcium content than Nx+PTx animals, whereas Nx+PTx+Sev animals showed a decrease in LV calcium content, compared to the other groups. CONCLUSIONS: This experimental model is useful to study CKD with ABD. The FeP seems to be a more reliable parameter than serum P to evaluate the effectiveness of P binders. Decreased FGF-23 levels were related to decreased PTH levels and hypocalcemia. Ca-treated animals showed Ca overload, as seen by higher calciuria, higher LV calcium content and higher eroded surface. The underlying mechanisms involved in sevelamer actions of decreased SOST expression were independent of PTH, serum P, renal function and TGF-?1 gene expression. Further studies are needed to a better understanding of these mechanisms

L’objectif de ce travail de thèse était de développer des outils pour détecter et traiter le cancer àun stade précoce. Nous avons donc entrepris la synthèse de nouveaux radiopharmaceutiques ciblantspécifiquement le récepteur CXCR4, en utilisant le savoir-faire et l'expertise de notre groupe dans lasynthèse et la fonctionnalisation des polyazacycloalcanes. Nous avons travaillé simultanément surdeux aspects : l’agent chélatant et la molécule vectrice.Dans un premier temps, les travaux ont concerné la conception, la synthèse et la caractérisationde nouveaux macrocycles à fort potentiel pour la chélation du cuivre et du gallium. Nous avons toutd’abord développé une nouvelle voie de synthèse permettant d’accéder à des dérivés homocyclènesC-functionnalisés. Nous nous sommes ensuite intéressés aux dérivés du 1,4,7-triazacyclononane(TACN). En optimisant une voie de synthèse déjà développée au laboratoire, nous avons facilitél’accès à des dérivés TACN N- et C-fonctionnalisés. Nous avons ainsi préparé une série denouveaux agents chélatants bifonctionnels adaptés pour la complexation du cuivre ou du gallium, envariant la nature de la fonction de greffage et des bras coordinants. Nous avons également réalisé lasynthèse de nouveaux cryptands en série cyclène et nous avons étudié leur propriété decomplexation vis à vis du cuivre.Dans un second temps, nous avons développé une nouvelle famille d’agents imageants duCXCR4 en modifiant la structure des AMD3100 et AMD3465. Ce travail a tout d’abord nécessité lamise au point de nouvelles méthodes de fonctionnalisation de ces structures. Nous avons ainsi pupréparer de nouveaux synthons porteur d’une fonction de greffage dans les deux séries. Nous avonsensuite introduit différentes sondes imageantes, telles que des chélates adaptés pour la complexationdu cuivre, gallium et indium ainsi que des sondes fluorescentes de type bodipy / The objective of this thesis work was to develop CXCR4-targeted tools to localize and treat cancer at an early stage. In this line, we investigated the synthesis of new target-specific radiopharmaceuticals. The work focused on two main axes, i.e. the chelating agent and the carrier, by using the know-how and the expertise of our group in polyazacycloalkanes synthesis and functionalization. In the first part, we were interested in developing new macrocyclic scaffolds of high potential for copper and gallium chelation. We first focused on the development of a new powerful route towards selectively functionalized constrained homocyclens. The second part was based on C-functionalized 1,4,7-triazacyclononane (TACN) and its derivatives. From a synthetic route previously developed in our group, we were able to facilitate and optimize the synthesis of selectively N- and C-functionalized TACN. By varying the grafting functions and the pendant coordinating arms, we prepared several really promising bifunctional chelating agents for copper and gallium chelation. We also investigated the synthesis of new cryptands based on cyclen and we studied their properties towards copper complexation. In the second part of this thesis work, we were interested in generating a new family of imaging agents based on well-known CXCR4 antagonists, i.e. AMD3100 and AMD3465. The access towards these agents first required the preparation of original building blocks by modification of the AMD3100 and AMD3465 cores. The conjugation of such platforms onto the appropriate probe enabled the synthesis of various systems for optical and nuclear imaging. Thus, we were able to introduce a bodipy dye and several chelators adapted for gallium, copper and indium chelation