Cold hardiness and resistance in winter are key factors determining the geographical distribution of plants. In addition, these factors have a huge impact on harvest of cultural plants. Strawberries, which are among the most important berry plants in the world and in Lithuania, are vulnerable to cold because of unstable snow cover, which is more and more often occurring during variable wintering conditions. Insufficient resistance of strawberries in winter, absence of clear criteria, which enable to select the most resistant varieties during a shorter time than the few year period, impedes the development and introduction of new, adaptive, fertile, and of high-quality berries strawberry cultivars. The mechanisms of cold hardiness were intensively investigated using model plants. However, there is a lack of knowledge about the genetic regulation mechanisms of winterhardiness of cultural plants. For the selection of resistant to cold plants, the knowledge about plants cold acclimation and factors determining cold resistance and controlling genes is necessary. Investigating the plants under controlled conditions in vitro, it is possible to investigate the influence of individual factors on acclimation and cold hardiness by disassociating from the influence of many different factors, which is unavoidable under natural conditions. The cold acclimation and cold hardiness of strawberries are important not only for breeding. Preservation of plant genetic resources for future... [to full text] / Atsparumas šalčiui ir ištvermingumas žiemą – pagrindiniai veiksniai, lemiantys augalų geografinį pasiskirstymą. Be to, šie veiksniai turi didžiulę įtaką kultūrinių augalų derlingumui. Braškės, kurios yra tarp svarbiausių uoginių augalų pasaulyje ir Lietuvoje, stipriai pašąla esant nepastoviai sniego dangai, vis dažniau pasitaikančiomis permainingomis žiemojimo sąlygomis. Nepakankamas braškių ištvermingumas žiemą, aiškių kriterijų, kurie leistų per trumpesnį nei kelių metų laikotarpį atrinkti ištvermingas veisles nebuvimas, apsunkina naujų, adaptyvių, derlingų, kokybiškomis uogomis, braškių veislių sukūrimą ir introdukciją. Atsparumo šalčiui mechanizmai intensyviai tirti naudojant modelinius augalus, tačiau žinių apie žiemojančių kultūrinių augalų, kurių įvairovė labai didelė, ištvermingumo žiemą mechanizmus ir jo genetinį reguliavimą labai trūksta. Atsparių šalčiui augalų atrankai vykdyti reikalingos žinios apie augalų užsigrūdinimą, apie atsparumą šalčiui lemiančius veiksnius ir juos kontroliuojančius genus. Tiriant augalus kontroliuojamomis sąlygomis in vitro, galima ištirti atskirų veiksnių įtaką užsigrūdinimui ir atsparumui šalčiui, atsiribojant nuo, neišvengiamo natūraliomis sąlygomis, daugelio įvairių veiksnių poveikio. Braškių užsigrūdinimas ir atsparumas šalčiui svarbūs ne vien tik atrankai. Genetinių išteklių išsaugojimas ateities kartoms - svarbus šiuolaikinės biologijos uždavinys. Didelių kolekcijų išsaugojimą palengvina ir sąnaudas sumažina, augalų laikymas... [toliau žr. visą tekstą]

Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / A range of epidemiological, clinical and experimental studies have demonstrated that exposure of an embryo to a suboptimal environment in vivo or ex vivo during early embryo development is associated with altered development of cardiovascular, neuroendocrine and metabolic disorders in adult life. A number of perturbations during early embryo development result in developmental adaptations by the embryo to ensure immediate survival, whilst programming the embryo for altered fetal and placental development, resulting in the eventual onset of adult disease. It has been previously shown that maternal nutrient restriction during the periconceptional period results in a hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in twin but not singleton pregnancies. It was therefore the first aim of this thesis to interrogate the impact of maternal undernutrition during the periconceptional period (defined as from at least 45 days prior until 7 days after conception) on fetal and placental development during early pregnancy at - day 55 of pregnancy, which coincides with the period of maximal placental growth. In Chapter 2, it has been demonstrated that there are important relationships between maternal weight gain during the periconceptional period and feto-placental growth during the first - 55 days of pregnancy and that periconceptional undernutrition has a differential effect on these relationships in singleton and twin pregnancies. In singleton pregnancies, periconceptional undernutrition disrupts the relationship between maternal weight gain during the periconceptional period and utero-placental growth and in twin pregnancies, periconceptional undernutrition results in the emergence of an inverse relationship between maternal weight gain during early pregnancy and uteroplacental growth and in a dependence of fetal growth on placental growth. (Chapter 2) In order to investigate the origins of the physiological adaptations that lead to the development of hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in late gestational fetuses after exposure as an embryo to periconceptional undernutrition, we investigated the development and steroidogenic capacity of the fetal adrenal gland and development of the fetal heart and kidney at - 55 days gestation (Chapter 3 and 4). The relative weight of the fetal adrenal and adrenal IGF-1, IGF-1 R, IGF-2, IGF-2R and CYP 17 mRNA expression were lower in twin compared to singleton fetuses. There was evidence that in control singletons, IGF-2R expression plays an important role in the regulation of adrenal growth and CYP 17 mRNA expression during early pregnancy. In control twins, however, whilst there was a significant positive relationship between adrenal CYP 17 and IGF-2 mRNA expression, adrenal weight was directly related to the level of adrenal IGF-1 mRNA expression. There was no effect of periconceptional undernutrition on the level of expression of any of the placental or adrenal genes in the study. In PCUN ewes, carrying singletons, however, there was a loss of the relationships between either adrenal IGF-2, IGF-2R and IGF-1 mRNA expression and adrenal growth and CYP 17 expression which were present in control singletons. Similarly in ewes carrying twins, maternal undernutrition during the periconceptional period resulted in the loss of the relationships between adrenal growth and IGF-1 expression and between _ adrenal CYP 17 and IGF-2 expression which were present in control twin fetuses. Whilst there was no effect of fetal number on fetal heart growth at - d55 in twin fetuses, there was a direct relationship between relative fetal heart and adrenal weights, which was present in both the PCUN and control groups. There was also a significant inverse relationship between maternal weight at conception and relative fetal heart weight in PCUN twin, but not PCUN singleton or control fetuses (Chapter 3). In control pregnancies maternal weight gain during the periconceptional period is inversely related to the relative weight of the fetal kidney at -55d pregnancy. In this group, relative kidney weight was also directly related to renal IGF-1 mRNA expression. In control twins maternal weight gain was inversely related to fetal kidney weight and this effect was ablated when the effects of maternal cortisol was controlled for in the analysis. In the PCUN group, whilst there was an inverse relationship between maternal weight gain during the periconceptional period and relative kidney weight, it was not possible to separate the independent effects of maternal weight loss during the periconceptional period and the subsequent weight gain during the period of refeeding. Renal IGF-1 mRNA expression was higher and renal lGF-1 R and 2R expression were lower in twin fetuses compared to singletons. After exposure to PCUN, renal IGF-1 expression was also higher than in control pregnancies independent of the fetal number (Chapter 4). Superovulation, artificial insemination, embryo transfer and in vitro embryo culture are used in a range of assisted reproductive technologies, and it has been demonstrated that varying the composition of the culture media can result in a change in pre and postnatal development. Culture of sheep embryos in media containing serum is associated with fetal overgrowth which is phenotypic of the Large Offspring Syndrome. It is not known how the combination of superovulation, artificial insemination and embryo transfer alone impacts fetoplacental development in late gestation of the sheep. There have been no studies, however, examining the differential impact of superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the absence or presence of human serum on feto-placental development in Singleton and twin pregnancies (Chapter 5). I have therefore tested the hypothesis that superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the presence or absence of human serum differentially alters the growth of the placenta, fetus and fetal organs during late gestation when compared to naturally conceived controls and that these effects are different in singleton and twin pregnancies. The fetal weight, CRL and abdominal circumference were significantly larger in IVCHS singleton fetuses. A novel finding in this study was lower fetal weights of twin fetuses in the ET and IVCNS groups compared to NM control twin fetuses. In addition, placental weights were lighter in twin fetuses in the ET, IVCNS and IVCHS treatment groups and this is partially due to a failure to initiate compensatory growth of placentomes in twin pregnancies (Chapter 5). The results of this thesis therefore highlight the complex interactions between the periconceptional environment (in vivo or ex vivo) and embryo or fetal number on the programming fetal and placental development. Maternal undernutrition during the periconceptional period and superovulation, artificial insemination and embryo transfer with or without in vitro culture in the absence or presence of serum alters fetal development, and I have demonstrated that these changes in fetal growth can be explained by changes in placental growth trajectory. Furthermore, a novel finding of this study is that perturbations of the periconceptional environment affect feto-placental development differently in singleton and twin pregnancies. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2006

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / A range of epidemiological, clinical and experimental studies have demonstrated that exposure of an embryo to a suboptimal environment in vivo or ex vivo during early embryo development is associated with altered development of cardiovascular, neuroendocrine and metabolic disorders in adult life. A number of perturbations during early embryo development result in developmental adaptations by the embryo to ensure immediate survival, whilst programming the embryo for altered fetal and placental development, resulting in the eventual onset of adult disease. It has been previously shown that maternal nutrient restriction during the periconceptional period results in a hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in twin but not singleton pregnancies. It was therefore the first aim of this thesis to interrogate the impact of maternal undernutrition during the periconceptional period (defined as from at least 45 days prior until 7 days after conception) on fetal and placental development during early pregnancy at - day 55 of pregnancy, which coincides with the period of maximal placental growth. In Chapter 2, it has been demonstrated that there are important relationships between maternal weight gain during the periconceptional period and feto-placental growth during the first - 55 days of pregnancy and that periconceptional undernutrition has a differential effect on these relationships in singleton and twin pregnancies. In singleton pregnancies, periconceptional undernutrition disrupts the relationship between maternal weight gain during the periconceptional period and utero-placental growth and in twin pregnancies, periconceptional undernutrition results in the emergence of an inverse relationship between maternal weight gain during early pregnancy and uteroplacental growth and in a dependence of fetal growth on placental growth. (Chapter 2) In order to investigate the origins of the physiological adaptations that lead to the development of hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in late gestational fetuses after exposure as an embryo to periconceptional undernutrition, we investigated the development and steroidogenic capacity of the fetal adrenal gland and development of the fetal heart and kidney at - 55 days gestation (Chapter 3 and 4). The relative weight of the fetal adrenal and adrenal IGF-1, IGF-1 R, IGF-2, IGF-2R and CYP 17 mRNA expression were lower in twin compared to singleton fetuses. There was evidence that in control singletons, IGF-2R expression plays an important role in the regulation of adrenal growth and CYP 17 mRNA expression during early pregnancy. In control twins, however, whilst there was a significant positive relationship between adrenal CYP 17 and IGF-2 mRNA expression, adrenal weight was directly related to the level of adrenal IGF-1 mRNA expression. There was no effect of periconceptional undernutrition on the level of expression of any of the placental or adrenal genes in the study. In PCUN ewes, carrying singletons, however, there was a loss of the relationships between either adrenal IGF-2, IGF-2R and IGF-1 mRNA expression and adrenal growth and CYP 17 expression which were present in control singletons. Similarly in ewes carrying twins, maternal undernutrition during the periconceptional period resulted in the loss of the relationships between adrenal growth and IGF-1 expression and between _ adrenal CYP 17 and IGF-2 expression which were present in control twin fetuses. Whilst there was no effect of fetal number on fetal heart growth at - d55 in twin fetuses, there was a direct relationship between relative fetal heart and adrenal weights, which was present in both the PCUN and control groups. There was also a significant inverse relationship between maternal weight at conception and relative fetal heart weight in PCUN twin, but not PCUN singleton or control fetuses (Chapter 3). In control pregnancies maternal weight gain during the periconceptional period is inversely related to the relative weight of the fetal kidney at -55d pregnancy. In this group, relative kidney weight was also directly related to renal IGF-1 mRNA expression. In control twins maternal weight gain was inversely related to fetal kidney weight and this effect was ablated when the effects of maternal cortisol was controlled for in the analysis. In the PCUN group, whilst there was an inverse relationship between maternal weight gain during the periconceptional period and relative kidney weight, it was not possible to separate the independent effects of maternal weight loss during the periconceptional period and the subsequent weight gain during the period of refeeding. Renal IGF-1 mRNA expression was higher and renal lGF-1 R and 2R expression were lower in twin fetuses compared to singletons. After exposure to PCUN, renal IGF-1 expression was also higher than in control pregnancies independent of the fetal number (Chapter 4). Superovulation, artificial insemination, embryo transfer and in vitro embryo culture are used in a range of assisted reproductive technologies, and it has been demonstrated that varying the composition of the culture media can result in a change in pre and postnatal development. Culture of sheep embryos in media containing serum is associated with fetal overgrowth which is phenotypic of the Large Offspring Syndrome. It is not known how the combination of superovulation, artificial insemination and embryo transfer alone impacts fetoplacental development in late gestation of the sheep. There have been no studies, however, examining the differential impact of superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the absence or presence of human serum on feto-placental development in Singleton and twin pregnancies (Chapter 5). I have therefore tested the hypothesis that superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the presence or absence of human serum differentially alters the growth of the placenta, fetus and fetal organs during late gestation when compared to naturally conceived controls and that these effects are different in singleton and twin pregnancies. The fetal weight, CRL and abdominal circumference were significantly larger in IVCHS singleton fetuses. A novel finding in this study was lower fetal weights of twin fetuses in the ET and IVCNS groups compared to NM control twin fetuses. In addition, placental weights were lighter in twin fetuses in the ET, IVCNS and IVCHS treatment groups and this is partially due to a failure to initiate compensatory growth of placentomes in twin pregnancies (Chapter 5). The results of this thesis therefore highlight the complex interactions between the periconceptional environment (in vivo or ex vivo) and embryo or fetal number on the programming fetal and placental development. Maternal undernutrition during the periconceptional period and superovulation, artificial insemination and embryo transfer with or without in vitro culture in the absence or presence of serum alters fetal development, and I have demonstrated that these changes in fetal growth can be explained by changes in placental growth trajectory. Furthermore, a novel finding of this study is that perturbations of the periconceptional environment affect feto-placental development differently in singleton and twin pregnancies. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2006

L’ischémie reperfusion pulmonaire et sa traduction clinique la dysfonction primaire du greffon sont responsables d’une morbi-mortalité importante en transplantation pulmonaire aussi bien à court terme qu’à long terme. Nous avons voulu faire la démonstration de la pertinence des microparticules comme marqueur de l’ischémie reperfusion pulmonaire. Nous avons reproduit et validé la stabilité d’un modèle de perfusion ventilation ex vivo de poumon de rat aussi bien en conditions normales (pas d’ischémie pulmonaire avant reperfusion) qu’en conditions extrêmes (1 h d’ischémie chaude avant reperfusion pulmonaire). Nous avons étudié la génération de microparticules par des poumons soumis à des conditions variables d’ischémie froide et d’ischémie chaude. Les poumons soumis à de fortes conditions d’ischémie froide (20h) produisent un pic précoce de microparticules d’origine épithéliale alvéolaire, leucocytaire et endothéliale. Nous en concluons que le modèle de perfusion ventilation ex vivo de poumons de rats est un modèle pertinent pour l’étude des réactions d’ischémie reperfusion. Les microparticules apparaissent comme un marqueur précoce des lésions d’ischémie reperfusion pulmonaires dans ce modèle. / Lung ischemia reperfusion and its clinical expression as primary graft dysfunction are provider of immediate and long term morbidity and mortality for patients. We aimed at demonstrating the usefulness and relevance of microparticles as biomarkers for lung ischemia reperfusion injury. We first reproduced an ex vivo rat lung perfusion and ventilation experimental model. Stability of the model was validated for normal conditions (no ischemia before reperfusion) as well as for extreme conditions (1 hour warm ischemia before reperfusion). The generation of microparticles was studied in that model for variable conditions of cold ischemia and for warm ischemia. Lung submitted to strong ischemic injury (20hours cold ischemia) generate an early pike of microparticles originated from leukocyes, endothelial cells, and epithelial alveolar cells. We may conclude the ex vivo model of rat lung perfusion and ventilation is relevant for the study of lung ischemia reperfusion injury. Microparticles are relevant markers of rat lung ischemia reperfusion injury in our model.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-07-23T21:20:51Z No. of bitstreams: 1 Lorena Pinto. Avaliação ex vivo da proliferação espontanea em PBMC de individuos infectados pelo HTLV-1 por citometria de fluxo.pdf: 1267124 bytes, checksum: 830b004821bb96ca261aed15410bcb82 (MD5) / Made available in DSpace on 2012-07-23T21:20:51Z (GMT). No. of bitstreams: 1 Lorena Pinto. Avaliação ex vivo da proliferação espontanea em PBMC de individuos infectados pelo HTLV-1 por citometria de fluxo.pdf: 1267124 bytes, checksum: 830b004821bb96ca261aed15410bcb82 (MD5) Previous issue date: 2010 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / O vírus linfotrópico de células T humanas do tipo 1 (HTLV-1) infecta cerca de 2% da população de Salvador-Bahia. O HTLV-1 é o agente etiológico da ATLL, HAM/TSP e uveíte. Este vírus também está relacionado a outras doenças inflamatórias como artrites, dermatites infectivas, polimiosites, alveolites e Síndrome de Sjögren. Uma das características imunológicas mais marcantes da infecção pelo HTLV-1 é a proliferação espontânea dos linfócitos T induzida por proteínas transativadoras virais, como Tax e HBZ. O papel da proliferação na patogênese da infecção não é conhecido, porém alguns trabalhos indicam que sua intensidade é maior nos pacientes com HAM/TSP, além disso pode ser responsável pela manutenção da carga proviral do HTLV-1, uma vez que o vírus se replica por divisão da célula infectada. A dinâmica da proliferação ex vivo não é muito conhecida, sendo normalmente avaliada por adição de 3[H]-Timidina às culturas, que possui várias desvantagens, entre as quais a toxicidade. Este é um estudo piloto que objetivou padronizar um método para avaliação da dinâmica da proliferação espontânea de linfócitos T utilizando o marcador CarboxyFluorescein diacetate Succinimidyl Ester (CFSE), por citometria de fluxo. Além de quantificar os índices de proliferação celular de linfócitos T totais e das subpopulações linfocitárias T CD4+ e T CD8+, correlacionar proliferação celular com a carga proviral do HTLV-1 e a expressão da proteína viral TAX. Para tal, PBMC de 30 pacientes infectados pelo HTLV-1 (16 assintomáticos e 14 HAM/TSP) foram cultivados por 24, 48, 72, 96 e 120 horas, em presença de CFSE. As células foram adquiridas em citometro de fluxo e os resultados analisados pelo programa FlowJo, através da porcentagem de células divididas e do índice de divisão celular. Observou-se proliferação em 66,7% dos indivíduos infectados pelo HTLV-1. A proliferação espontânea de PBMC foi superior no grupo de pacientes com HAM/TSP (porcentagem de células divididas: 79%, índice de divisão celular: 79%), comparada aos assintomáticos (porcentagem de células divididas: 50%, índice de divisão celular: 56,3%), porém essa diferença não foi significante A proliferação espontânea pode ser detectada nas primeiras 24 horas de cultura. A intensidade de proliferação é semelhante para as subpopulações de linfócitos T CD4 e T CD8, tanto em indivíduos assintomáticos como naqueles com HAM/TSP. Não houve correlação entre a carga proviral e a porcentagem de células divididas (r= -0,009; p= 0,9) e índice de divisão celular (r=0,1; p=0,5). A média de expressão de TAX em linfócitos TCD4+ foi de 2,4±2,4 %. Houve correlação entre a expressão da proteína Tax e a porcentagem de células divididas (r=0,59; p =0,05) e o índice de divisão celular (r=0,60; p=0,05), porém sem significância estatística. No entanto, encontrou-se uma correlação positiva entre a porcentagem de células T CD4+ divididas e a expressão da proteína Tax (r=0,79; p<0,003), bem como entre o índice de divisão das células TCD4+ e a expressão da proteína Tax (r=0,75; p=0,008). Em conclusão, a avaliação da proliferação espontânea por citometria de fluxo, em culturas com CFSE avaliadas pelo programa FlowJo permite identificar a proliferação celular nas 24 horas inicias da cultura e quantificar a proporção de linfócitos T CD4 e TCD8 que proliferam. Este método pode ser útil na avaliação de drogas que modulam a proliferação espontânea em PBMC de indivíduos infectados pelo HTLV-1. / Around 2% of the population of Salvador-Bahia are infected by the Human-T Lymphocyte virus type I (HTLV-1). This virus is the etiologic agent of ATLL, HAM/TSP and uveitis. It is also related to inflammatory illness like arthritis, infective dermatitis, polymyositis, alveolitis and Sjorgen syndrom. The spontaneous proliferation of T-lymphocytes induced by viral transactivating proteins like Tax and HBZ is one of the most outstanding immunological characteristics of the infection. The role of the proliferation in the pathogenesis is still unknown though some studies have shown that it is higher among HAM/TSP patients. Moreover, it could be responsible for the HTLV-1 remaining proviral load since the virus replicate through division of infected cell. The dynamics of the proliferation ex-vivo is not well known and is usually assessed by incorporating 3[H]-Thymidine to the cultures. This method has several disadvantages one of them being the 3[H]-Thymidine toxicity. This pilot study was aimed at the standardization of a method that assesses the dynamics of the spontaneous T-lymphocytes proliferation using flow cytometry and CarboxyFluorescein diacetate Succinimidyl Ester (CFSE) as a marker. Other objectives were to assess the rates of celular proliferation of both total T lymphocytes and CD4+ and T CD8+ subpopulations; to correlate the celular proliferation with the HTLV-1 viral load and the expression of the viral TAX protein. PBMCs of 30 HTLV-1 infected patients (16 assymptomatic and 14 HAM/TSP) were cultivated for 24, 48, 72, 96 and 120 hours in the presence of CFSE. Cells were obtained by flow cytometry and the results were analysed with the software Flowjo through the percentage of divided cells and the rate of celular division. Cell proliferation was observed in 66.7% of the HTLV-1 infected people. The PBMC spontaneous proliferation was higher in the group of HAM/TSP patients (percentage of divided cells:79%, rate of cellular division79%) compared to the assymptomatic individuals (percentage of divided cells: 50%, rate of cellular division: 56,3%) though this difference was not significant. Spontaneous proliferation can be detected in the first 24 hours of cell cultivation. The intensity of proliferation is similar in T CD4 e T CD8 subpopulations of assympomatic individuals and HAM/TSP patients. There was no correlation between proviral load and percentage of divided cells (r= -0,009; p= 0,9) and the rate of cellular division (r=0,1; p=0,5). The average of the TAX expression in T CD4+ was 2,4±2,4 %. There was a correlation between the expression of TAX protein and the percentage of divided cells (r=0,59; p =0,05) and the rate of cellular division (r=0,60; p=0,05), although not statistically significant. Nevertheless, a positive correlation was found between the percentage of divided T CD4+ cells and the expression of TAX protein (r=0,79; p<0,003), as well as between the rate of cellular division of TCD4+ cells and the expression of TAX protein (r=0,75; p=0,008). As a conclusion, the assessment of spontaneous proliferation by flow cytometry in cultures with CFSE analysed with the FlowJo software allows to identify the cellular proliferation in the first 24 hours of cultivation and to quantify the proportion of T CD4 and TCD8 lymphocytes that proliferated. This method could be usefull to assess drugs that modulate the spontaneous proliferation in PBMCs from HTLV-1 infected individuals.

L’incorporation croissante des (nanomatériaux) NMx dans les aliments et les emballages a contribué à une demande sociétale majeure au regard de l’évaluation des risques des NMx sur la santé. Toutefois, en raison des nombreux paramètres des NMx (taille, forme, structure cristalline, solubilité…), ainsi que des processus physiologiques (comme la digestion) pouvant impacter sur l’absorption et la réponse toxique des NMx, l’évaluation des risques des NMx est compliquée. De plus, leur évaluation in vitro est délicate en raison d’interférences (optiques, catalytiques…) lors de la réalisation des tests. Notre projet de recherche visait à déterminer, l’impact des paramètres d’hydrophobicité des NMx de TiO2 de structure cristalline rutile et l’impact de la solubilité des NMx d’Al0 et Al2O3 sur leur toxicité/génotoxicité au niveau intestinal (organe primo-exposé) et hépatique (organe d’accumulation). Les effets de ces NMx ont été étudiés par une combinaison de méthodes complémentaires in vivo par gavage sur rat, et in vitro sur les lignées humaines Caco-2 et HepaRG différenciées, tout en tenant compte des interférences in vitro. Aucune réponse toxique et génotoxique n’a été observée in vitro malgré la différence de revêtement hydrophobe/hydrophile des NMx de TiO2. Seuls les NMx d’Al2O3 ont induit des lésions oxydatives de l’ADN mais uniquement dans les cellules Caco-2, tandis que de fortes interférences ont empêché de conclure avec les NMx d’Al0. Aucun dommage chromosomique n’a été observé pour ces NMx. In vivo aucun effet génotoxique n’a été observé dans l’intestin, le colon et le foie mais des dommages à l’ADN ont été décelés avec les NMx d’Al2O3 dans la moelle osseuse. La comparaison des résultats avec ceux de la forme ionique AlCl3 suppose un mécanisme de génotoxcité indépendant de la solubilité des NMx d’Al0 et d’Al2O3 dans les milieux biologiques. Malgré les nombreux progrès en nanotoxicologie, l’ensemble de nos résultats a souligné la difficulté d’obtenir des conclusions fiables avec des tests classiques utilisés pour les produits chimiques in vitro, la difficulté d’extrapolation in vitro/in vivo des effets des NMx et le besoin de poursuivre les recherches pour disposer de méthodes et d’outils permettant d’évaluer les effets des NMx de manière fiable. / The growing incorporation of nanomaterials (NMs) into food and packaging has contributed to the increasing demand for the assessment of the health hazards of these particles. However, this task is rendered difficult since the numerous intrinsic parameters (size, shape, crystalline structure, solubility ...), as well as physiological processes (such as digestion) can have an impact on the absorption and toxicological responses of NMs. Moreover, their evaluation in vitro is complicated by various sources of interference (optical, catalytic …) with toxicity tests. Our research project aimed to evaluate, the impact of hydrophobicity of rutile TiO2 NMs and solubility of AlO and Al2O3 NMs on their intestinal (first-exposed organ) and hepatic (accumulation organ) toxicity/genotoxicity. The effects of these NMs were investigated by a combination of complementary methods, in the rat in vivo by gavage, and in vitro using differentiated human Caco-2 and HepaRG cell lines, while taking into account potential interference with in vitro tests. No toxic/genotoxic response was observed in vitro despite the difference of hydrophobic/hydrophilic surface coating for TiO2 NMs. Only Al2O3 induced oxidative DNA damage solely in Caco-2 cells, while significant interference led to inconclusive results for AlO NMx. No chromosomal damage was observed for Al0 or Al2O3 NMx. In vivo no genotoxic effect was observed in the intestine, colon and liver but DNA damage was detected with Al2O3NMx in the bone marrow. Comparison of results with those for the ionic form AlCl3 demonstrated that effects observed were not related to the solubility of Al0 and d’ Al2O3 NMs in the biological environment. Despite considerable progress in nanotoxicology, our results have highlighted the difficulty to obtain reliable re sults with the traditional toxicity tests used for chemical compounds in vitro, the difficulty associated with the in vitro/in vivo extrapolation of the effects of NMs, as well as the need to continue research aimed at developing robust and reliable methods and tools for the evaluation of the effects of NMs.

L'implantation d'îlots de Langerhans microencapsulés est une thérapie prometteuse pour le diabète de type 1. Le concept est de rétablir la fonction de sécrétion d'insuline tout en évitant le rejet de greffe. Les premiers essais cliniques ont reporté des résultats encourageants mais encore peu reproductibles. En effet, les techniques actuelles de production de microcapsules sont manuelles et au sein d'un même lot les capsules ne sont pas homogènes. L'utilisation de la microfluidique offre la possibilité de remédier à ce problème. Ce projet présente les différentes étapes d'optimisation d'un système microfluidique complexe qui automatise le procédé d'encapsulation monocouche de cellules dans des capsules polymériques d'alginate. Ce système comporte trois fonctions principales en série : la formation de gouttes monodisperses d'alginate en flux d'huile par un module MFFD (Micro Flow Focusing Device), le transfert de ces gouttes de la phase huileuse vers une phase aqueuse gélifiante de calcium et enfin un second transfert vers un flux à concentration physiologique. Des capsules monodisperses et sphériques ont été obtenues en sortie de ce système et des premiers tests d'encapsulation de cellules ont été réalisés. Les capsules produites par le système automatisé ont conduit à une première implantation chez le rongeur. Ce système est une première étape clé vers un dispositif instrumenté qui permettrait aux cliniciens d'encapsuler des îlots rapidement et de façon reproductible directement après leur isolement, puis de les implanter chez les patients diabétiques. Mots clés : encapsulation, îlots de Langerhans, alginate, gélification, microfluidique, automatisation, MFFD, transfert de phase. / Epileptic seizures arise from pathological synchronization of neuronal ensemble.Seizures originating from primary motor cortex are often pharmacoresistant, and many times unsuitable for respective surgery because of location of epileptic focus in eloquent area. Basal ganglia play important role in seizure propagation. Micro electrode recordings performed during previous studies indicated that input structures of basal ganglia such as GPe, Putamen and Subthalamic nucleus (STN) are strongly modified during seizures. For example the mean firing rate of neurons of the STN and Putamen increased and the percentage of oscillatory neurons synchronized with the ictal EEG was higher during seizures as compared to interictal periods. Pilot studies in humans have shown the possible beneficial effect of chronic DBS applied to STN in treatment of pharmacoresistant motor seizures. Our study was aimed at studying the therapeutic effect of electrical stimulation of input structures of basal ganglia . We first developed a stable, predictable primate model of focal motor epilepsy by intracortical injection of penicillin and we documented it's pharmacoresistence. We then stereotactically implanted DBS electrodes in the STN and Putamen. The stimulator was embedded at the back of the animals. Subthreshold electrical stimulations at 130 Hz were applied to STN. Stimulator was turned ON when penicillin was injected. Sham stimulation at 0 volt was used as a control situation, each monkey being its own control. The time course, number and duration of seizures occurring in each epochs of 1 h were compared during ON and sham stimulation periods. Each experimental session lasted uptoo 6 hours,We also studied preventive high frequency stimulation of STN and subthershold low frequency stimulation of Putamen with 5 Hz and 20 Hz in the same model .Finally we studied combined effects of high frequency STN and low frequency Putamen stimulation in one monkey Results: Data was analysed from 1572 seizures in 30 experiments in three monkeys for chronic STN stimulation , 454 seizures in 10 experiments in one moneky during preventive STN stimulation ,289 seizures from 14 experiments in two monkeys during LFS putamen stimulation and 477 seizures from 10 sessions during combined STN and Putamen stimulation in one monkey The best results were observed during chronic STN stimulation The occurrence of first seizure was significantly delayed as compared to sham situation. Total time spent in focal seizures was significantly reduced by ≥69% on an average (p ≤0.05) after STN stimulation, due to a significant decrease in the number of seizures especially so during the first 3 hours after stimulation. The duration of individual seizures reduced moderately. Bipolar and monopolar stimulation modes were equally effective Preventive HFS STN (in one specimen) was not found to be superior to acute stimulation. LFS Putamen alone was effective but mainly in first two hours of stimulation .In a combined HFS STN and LFS Putamen stimulation the effect of stimulation in terms of seizure control was modest and poor compared to HFS STN alone or LFS Putamen alone. This study provides original data in primates showing the potential therapeutic effect of chronic HFS-STN DBS to treat focal motor seizures . A discussion explaining these

Made available in DSpace on 2015-05-07T14:46:38Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 600159 bytes, checksum: ea31fed3515d9c4355930a60418a459e (MD5) Previous issue date: 2010-09-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Law of Registration of the Patrimônio Vivo Pernambucano can be identified as an instrument of the State which aims to record and protect producers of the popular culture of Pernambuco, bringing in the context of media activism, we identify the occurrence of an institutionalization and why not say, a nationalization of the popular activities representative for the state. That&#8223;s why the state is also contributing to the folkmedia activism. The state gives support to the folk media activists, already registered, be able to act in their communication networks. As well as representatives of their origin groups, the Patrimônio Vivo become a representation of the identity and culture of Pernambuco. Of course we know that by recognizing these groups and people as producers and disseminators icons of the popular culture in Pernambuco, the state somehow projects a little of its cultural identity and, having no doubts, the media, in particular the one being part of this study, the newspaper Jornal do Comercio and the website pe360graus, they are means of communication that make the range and the reach of this projection become even greater. This study aims to understand how the mediation process regarding the living heritage, the state, the society and the media, all these aspects seen from the perspective of the media activism made by those living heritage. / A Lei de Registro de Patrimônio Vivo Pernambucano pode ser identificada como um instrumento do Estado que procura registrar e proteger os produtores da cultura popular de Pernambuco, trazendo para o contexto do ativismo midiático identifica-se a ocorrência de uma institucionalização e porque não dizer, uma estatização das atividades populares representativas para o Estado. É nesse sentido que o Estado também está contribuindo com o ativismo folkmidiático. O Estado dá respaldo para que os ativistas folkmidiáticos já registrados possam atuar em suas redes comunicacionais. Além de representantes de seus grupos de origem os Patrimônios Vivos passam a serem representativos da identidade e da cultura de Pernambuco. Naturalmente sabe-se que, ao reconhecer esses grupos e pessoas como ícones produtores e disseminadores da cultura popular pernambucana, o Estado já projeta de certa forma um pouco sua identidade cultural e, sem dúvidas, a mídia, em particular nesse estudo, o Jornal do Commercio e o site pe360graus são veículos que permitem que o alcance e a abrangência desta projeção tornem-se ainda maior. Este estudo busca entender como se processam as mediações entre os patrimônios vivos, o Estado, a sociedade e a mídia, todos esses aspectos vistos sob a ótica do ativismo midiático realizado por esses patrimônios vivos.