No description available.

Coal is one of the major energy sources in the world and contains most of the elements from the periodic table. During combustion of coal these elements are released and redistributed. This may lead to environmental problems. Some of these elements are considered to be very dangerous for human and animal health and ecosystems. The knowledge of concentration and speciation of elements in coal is important for the prevention of the adverse environmental phenomena associated with the use of coal. One of the hazardous elements in coal is lead. The purpose of this work is to determine the concentration of lead and its isotopic composition simultaneously with determining the speciation of lead in coal. The ICP-MS method was used to determine the concentration and isotope ratios of lead. A total of 62 samples of subbituminous coal was analyzed. The method of selective extraction analysis BCR was used on 9 samples of subbitumnious coal to identify the speciation of lead in coal. Lead concentrations in coal were measured in the range of 0.25 to 78.84 mg·kg-1 . These concentrations correspond to the average concentrations of lead in most of the coals. Isotope ratio 206 Pb/207 Pb in coal samples ranged from 1.169 to 1.219. Isotopic 208 Pb/206 Pb ratio was measured in the interval 2.047 to 2.093. The isotopic...

A Lama Negra de Peruíbe é utilizada em tratamentos terapêuticos, tais como, psoríase, dermatites periféricas, acne e seborreia, além de utilizações em mialgias, artrites e processos reumáticos não articulares. Assim como a demais argilas medicinais ela pode não estar isenta de possíveis efeitos danosos à saúde, sendo os principais, a ocorrência de minerais perigosos ao sistema respiratório e possíveis efeitos devido à presença de elementos tóxicos. Uma vez utilizado com finalidade terapêutica, um material deve ser completamente caracterizado e, desta forma, amostras da lama negra de Peruíbe foram analisadas para determinar suas propriedades físicas e químicas: teor de umidade, matéria orgânica e perda ao fogo; pH, granulometria, capacidade de troca catiônica e grau de inchamento; composição elementar determinada por Análise por Ativação Neutrônica, Absorção Atômica com Forno de Grafite e fluorescência de raios X e composição mineralógica determinada por difração de raios X. Outra ferramenta bastante utilizada para avaliar o comportamento de elementos traço em diversas matrizes ambientais é a extração sequencial. Sendo assim, foi feito um processo de extração sequencial para fracionar a lama em formas geoquímicas específicas e verificar como e em que quantidade os elementos estão contidos nela. Considerando os diversos procedimentos de extração seqüencial, foi utilizado o método BCR-701 (Community Bureau of Reference) por ser o mais reprodutivo entre eles bem como uma extração simples com suor artificial a fim de se avaliar quais elementos estão potencialmente disponíveis para absorção pela pelo do paciente durante um tratamento tópico. Os resultados indicaram que a lama é constituída basicamente por um material silto-argiloso, rico em matéria orgânica e com boa capacidade de troca catiônica. Não foram observadas variações significativas na composição mineralógica e elementar das formas in natura e maturada da lama. As análises por extração sequencial e extração simples indicaram que os elementos que estão eventualmente disponíveis em maior quantidade para serem absorvidos pela pele durante o tratamento são Ca, Mg, Mn e Na. / The Peruíbe Black mud is used in therapeutic treatments such as psoriasis, peripheral dermatitis, acne and seborrhoea, as well as in the treatment of myalgia, arthritis, rheumatism and non-articular processes. Likewise other medicinal clays, it may not be free from possible adverse health effects due to possible hazardous minerals leading to respiratory system occurrences and other effects, caused by the presence of toxic elements. Once used for therapeutic purposes, any given material should be fully characterized and thus samples of Peruíbe black mud were analyzed to determine physical and chemical properties: moisture content, organic matter and loss on ignition; pH, particle size, cation exchange capacity and swelling index. The elemental composition was determined by Neutron Activation Analysis, Atomic Absorption Graphite Furnace and X-ray fluorescence; the mineralogical composition was determined by X-ray diffraction. Another tool widely used to evaluate the behavior of trace elements, in various environmental matrices, is the sequential extraction. Thus, a sequential extraction procedure was applied to fractionate the mud in specific geochemical forms and verify how and how much of the elements may be contained in it. Considering the several sequential extraction procedures, BCR-701 method (Community Bureau of Reference) was used since it is considered the most reproducible among them. A simple extraction with an artificial sweat was, also, applied in order to verify which components are potentially available for absorption by the patient skin during the topical treatment. The results indicated that the mud is basically composed by a silty-clay material, rich in organic matter and with good cation exchange capacity. There were no significant variations in mineralogy and elemental composition of both, in natura and mature mud forms. The analysis by sequential extraction and by simple extraction indicated that the elements possibly available in larger quantities to be absorbed by the skin during treatment are Ca, Mg, Mn and Na.

A Lama Negra de Peruíbe é utilizada em tratamentos terapêuticos, tais como, psoríase, dermatites periféricas, acne e seborreia, além de utilizações em mialgias, artrites e processos reumáticos não articulares. Assim como a demais argilas medicinais ela pode não estar isenta de possíveis efeitos danosos à saúde, sendo os principais, a ocorrência de minerais perigosos ao sistema respiratório e possíveis efeitos devido à presença de elementos tóxicos. Uma vez utilizado com finalidade terapêutica, um material deve ser completamente caracterizado e, desta forma, amostras da lama negra de Peruíbe foram analisadas para determinar suas propriedades físicas e químicas: teor de umidade, matéria orgânica e perda ao fogo; pH, granulometria, capacidade de troca catiônica e grau de inchamento; composição elementar determinada por Análise por Ativação Neutrônica, Absorção Atômica com Forno de Grafite e fluorescência de raios X e composição mineralógica determinada por difração de raios X. Outra ferramenta bastante utilizada para avaliar o comportamento de elementos traço em diversas matrizes ambientais é a extração sequencial. Sendo assim, foi feito um processo de extração sequencial para fracionar a lama em formas geoquímicas específicas e verificar como e em que quantidade os elementos estão contidos nela. Considerando os diversos procedimentos de extração seqüencial, foi utilizado o método BCR-701 (Community Bureau of Reference) por ser o mais reprodutivo entre eles bem como uma extração simples com suor artificial a fim de se avaliar quais elementos estão potencialmente disponíveis para absorção pela pelo do paciente durante um tratamento tópico. Os resultados indicaram que a lama é constituída basicamente por um material silto-argiloso, rico em matéria orgânica e com boa capacidade de troca catiônica. Não foram observadas variações significativas na composição mineralógica e elementar das formas in natura e maturada da lama. As análises por extração sequencial e extração simples indicaram que os elementos que estão eventualmente disponíveis em maior quantidade para serem absorvidos pela pele durante o tratamento são Ca, Mg, Mn e Na. / The Peruíbe Black mud is used in therapeutic treatments such as psoriasis, peripheral dermatitis, acne and seborrhoea, as well as in the treatment of myalgia, arthritis, rheumatism and non-articular processes. Likewise other medicinal clays, it may not be free from possible adverse health effects due to possible hazardous minerals leading to respiratory system occurrences and other effects, caused by the presence of toxic elements. Once used for therapeutic purposes, any given material should be fully characterized and thus samples of Peruíbe black mud were analyzed to determine physical and chemical properties: moisture content, organic matter and loss on ignition; pH, particle size, cation exchange capacity and swelling index. The elemental composition was determined by Neutron Activation Analysis, Atomic Absorption Graphite Furnace and X-ray fluorescence; the mineralogical composition was determined by X-ray diffraction. Another tool widely used to evaluate the behavior of trace elements, in various environmental matrices, is the sequential extraction. Thus, a sequential extraction procedure was applied to fractionate the mud in specific geochemical forms and verify how and how much of the elements may be contained in it. Considering the several sequential extraction procedures, BCR-701 method (Community Bureau of Reference) was used since it is considered the most reproducible among them. A simple extraction with an artificial sweat was, also, applied in order to verify which components are potentially available for absorption by the patient skin during the topical treatment. The results indicated that the mud is basically composed by a silty-clay material, rich in organic matter and with good cation exchange capacity. There were no significant variations in mineralogy and elemental composition of both, in natura and mature mud forms. The analysis by sequential extraction and by simple extraction indicated that the elements possibly available in larger quantities to be absorbed by the skin during treatment are Ca, Mg, Mn and Na.

Les vols spatiaux sont source de nombreux stress conduisant à un affaiblissement du système immunitaire. L’efficacité de ce système repose notamment sur la diversité des répertoires de récepteurs aux antigènes présents à la surface des lymphocytes B (BCR) et T (TCR) permettant de reconnaitre un grand nombre d’antigènes différents. Au cours de cette thèse, j’ai étudié la diversité des récepteurs à l’antigène dans trois modèles animaux différents : l’amphibien Pleurodeles waltl, le modèle murin de suspension anti‐orthostatique (micropesanteur simulée) et le modèle murin CUMS (pour « Chronic Unpredictable Mild Socio‐environmental stressors ») qui fait appel à des stress sociaux et environnementaux chroniques similaires à ceux rencontrés lors des vols spatiaux. L’étude des répertoires de chaînes lourdes d’anticorps IgM et IgY de P. waltl a montré que ceux‐ci présentent une diversité importante, faisant de cet animal un bon modèle pour étudier les effets d’un vol spatial sur le système immunitaire humoral. Nous avons aussi montré que l’exposition à la suspension anti‐orthostatique durant 21 jours diminue la lymphopoïèse B mais n’affecte que modérément la diversité du répertoire de chaînes lourdes d’IgM. Ces résultats ont été comparés à ceux obtenus avec des souris âgées afin de savoir si la suspension anti‐orthostatique induit un vieillissement accéléré du système immunitaire. Même si nous avons noté des similitudes intéressantes entre ces deux groupes de souris, nous avons constaté que l’effet du vieillissement sur le répertoire d’IgM est plus important que celui de la suspension anti‐orthostatique, suggérant que le temps d’exposition au modèle anti‐orthostatique devrait être augmenté pour accentuer ses effets sur le répertoire d’anticorps. Quant au modèle CUMS, nous avons montré que son application durant la gestation n’impacte pas la lymphopoïèse T chez les souriceaux nouveau‐nés mais affecte 25% de leur répertoire de chaînes lourdes β du TCR. Ces résultats suggèrent que des stress socio‐environnementaux chroniques, même de faibles intensités, pourraient modifier les capacités de reconnaissance antigénique de l’hôte / Spaceflight is a source of various stresses leading to the weakening of the immune system. The efficiency of this system relies, notably, on the diversity of antigen receptor repertoires present on B (BCR) and T (TCR) cells, allowing the recognition of a vast array of antigens. During this thesis, I studied the diversity of antigen receptors in three different animal models: the amphibian Pleurodeles waltl, the murine anti‐orthostatic suspension model (simulated microgravity) and the CUMS (for "Chronic Unpredictable Mild Socio‐environmental stressors") murine model involving exposure to chronic social and environmental stressors similar to those encountered during spaceflights. Analyses of P. waltl IgM and IgY heavy chain repertoires have shown that they are highly diverse, making this species a nice animal model for studying the effects of spaceflight on the humoral immune system. We have also shown that 21 days of anti‐orthostatic suspension decrease murine B lymphopoiesis and moderately affect IgM heavy chain repertoire diversity. These results were compared with those obtained with old mice to determine if anti‐orthostatic suspension induces an accelerated aging of the immune system. Although we noted interesting similarities between these two groups of mice, we found that the effect of aging on IgM repertoire is stronger than that of the anti‐orthostatic suspension, suggesting that anti‐orthostatic duration should be extended to increase the effects of this model on antibody repertoire. Finally, regarding the CUMS model, we have shown that, when applied during gestation it does not affect T lymphopoiesis in newborn mice but affects 25% of their TCRβ heavy chain repertoire. These results suggest that low‐intensity chronic socio‐environmental stressors may alter antigen recognition capabilities of the host

Les protéines STAT5A et B sont des facteurs de transcription jouant un rôle important dans l'hématopoïèse normale et leucémique. Ce sont en effet des effecteurs essentiels d’oncogènes à activité tyrosines kinases, tels que BCR-ABL ou JAK2V617F responsables de la genèse d’hémopathies malignes. Ces oncogènes régulent la production de ROS (Reactive Oxygen Species) via l’activation de différentes voies de signalisation impliquées dans la prolifération et la survie cellulaire. Dans ce travail de thèse, nous montrons que l’activation oncogénique de STAT5, induite par BCR-ABL, favorise un stress oxydatif dans les cellules de Leucémie Myéloïde chronique (LMC), via la répression de l’expression des enzymes anti-oxydantes catalase et glutaredoxine-1 et la modulation potentielle de l’activité des NADPH oxydases. Nous montrons pour la première fois que l’effet pro-oxydant de STAT5 est régulé par la phosphorylation sur tyrosine de ces protéines et que les formes non phosphorylées et transcriptionnellement inactives exercent un effet anti-oxydant et protecteur contre le stress oxydatif, via des mécanismes non canoniques. Cette dualité de fonction est illustrée dans un modèle de co-culture de cellules de LMC et de cellules stromales médullaires, que nous avons développé dans le laboratoire afin de mimer le microenvironnement médullaire des cellules leucémiques. Dans ce modèle, nous montrons que le contact avec les cellules stromales permet d’inactiver STAT5 dans les cellules leucémiques et donc de promouvoir son activité anti-oxydante. Nous observons également un arrêt de prolifération et une entrée en phase G0 du cycle cellulaire des cellules leucémiques au contact des cellules stromales, ainsi qu’une résistance accrue de ces cellules à l’Imatinib, un inhibiteur de BCR-ABL. Ces données suggèrent un lien important entre activité anti-oxydante de STAT5, quiescence et chimio résistance des cellules leucémiques. / The Signal Transducer and Activator of Transcription factors 5A and B are two closely related STAT family members that play a major role in normal and leukemic hematopoiesis. STAT5 proteins are frequently activated in hematopoietic neoplasms and are targets of various tyrosine kinase oncogenes such as BCR-ABL and JAK2V617F. Both oncogenes were shown to stimulate the production of intracellular ROS (Reactive Oxygen Species) in leukemic cells and evidences for a cross talk between STAT5 and ROS metabolism have recently emerged. Herein, we demonstrate that sustained activation of STAT5 induced by BCR-ABL promotes ROS production in Chronic Myeloid Leukemia (CML) cells by repressing expression of two antioxidants, catalase and glutaredoxin1 and by possible functional interactions with NADPH oxidase complexes. We also provide compelling evidences that tyrosine phosphorylation regulate the pro-oxidant activity of STAT5 and that non phosphorylated STAT5 displays antioxidant properties and protection against oxidative stress via non-genomic effects. This dual function of STAT5 is also illustrated in an in vitro microenvironment model that we develop in our laboratory to analyze interactions between bone marrow stromal cells and CML cells. Using these coculture experiments, we show that STAT5 phosphorylation was reduced and its antioxidant activity enhanced in leukemic cells in contact with stromal cells. We also demonstrate in this model that leukemic cells stopped dividing, entered a quiescent G0 state and became resistant to Imatinib, a BCR-ABL kinase inhibitor. Collectively, these findings suggest an important link between antioxidant activity of STAT5, quiescence and resistance to chemotherapeutic agents in leukemic cells.

Les progéniteurs hématopoïétiques se différencient dans la moelle osseuse, au contact des cellules stromales, indispensables pour leur survie. Lors de la lymphopoïèse B, les progéniteurs se différencient suivant plusieurs étapes successives en cellules pro-B, pré-BI, pré-BII, puis B immatures, au cours desquelles se mettent en place les réarrangements des gènes codant pour les chaînes lourdes et légères des immunoglobulines. Les cellules pré-BII, qui expriment le récepteur pré-B (pré-BCR) à leur surface, constituent un point de contrôle essentiel lors du développement B. Le laboratoire a précédemment démontré que la galectine-1 (gal1), produite par les cellules stromales, fait un lien entre le pré-BCR et certaines intégrines afin de former une « synapse immunologique » entre les cellules pré-BII et les cellules stromales, conduisant ainsi à la relocalisation puis à l’activation du pré-BCR.Au cours de ma thèse, je me suis intéressée au rôle du stroma médullaire à l’étape des cellules pré-BII. Nous avons tout d’abord démontré l’importance de la formation de la synapse et des interactions entre les pré-BCR, les intégrines et la gal1 pour la prolifération et la différenciation des cellules pré-B in vivo. Enfin, nous avons caractérisé les cellules stromales de la moelle osseuse qui expriment la gal1. Ce travail a montré que la majorité des cellules pré-BII, au contraire des autres progéniteurs B, se situe au contact des cellules stromales gal1+, apportant pour la première fois la preuve de l’existence d’une niche stromale spécifique aux cellules pré-BII. / In the bone marrow, hematopoietic progenitors differentiate in close contact with stromal cells, essential for their survival. During B cell development, the progenitors differentiate through several sequential stages including pro-B cells, pre-BI cells, pre-BII cells and immature B cells, which allow setting up the rearrangements of genes encoding the immunoglobulin heavy and light chains. The expression of a functional pre-B cell receptor (pre-BCR) at the surface of the pre-BII cells represents a crucial checkpoint during B cell differentiation. The laboratory has previously demonstrated that the stromal cell-derived galectin-1 (gal1) is a link between the pre-BCR and certain integrins. This binding drives the pre-BCR in the pre-BII/stromal cell synapse, leading to the initiation of pre-BCR signaling.During my PhD, I have been interested in the role of stromal cells at the pre-BII cell stage. We first demonstrated the importance of synapse formation and the importance of the interactions between the pre-BCR, integrins and gal1 for the proliferation and differentiation of pre-BII cells in vivo. Finally, we characterized the bone marrow stromal cells which express gal1. This work showed that the majority of pre-BII cells, unlike other B cell progenitors, was in contact with gal1+ stromal cells, providing the first evidence of the existence of a specific stromal cell niche for the pre-BII cells.

Die vorliegende Arbeit handelt von einer in vitro Untersuchung der Stoffwechselveränderun-gen durch die Expression von BCR/ABL bei BaF3-Zellen, einer murinen, IL-3-abhängigen B-Zelllinie. Die Zellen wurden in nährstoffreichem Standard- und in durch Titrationen ermittel-tem nährstoffarmem Minimalmedium auf unterschiedliche Stoffwechselaktivität in Abhän-gigkeit von BCR/ABL-Expression untersucht sowie auf die zusätzliche Beeinflussbarkeit durch IL-3. Danach wurden vergleichend zwischen den 2 Zelllinien (BaF3 und BaF3-BCR/ABL) im Minimalmedium und im Standardmedium Metabolite wie Glukose, Laktat und Aminosäuren bestimmt, wobei BaF3-BCR/ABL sowohl mit als auch ohne IL-3 kultiviert wur-de. Um den Einfluss von Nährstoffrestriktion auf die Therapie zu zeigen, wurden anschlie-ßend vergleichend in den beiden Medien die Tyrosinkinaseinhibitoren Imatinib und Nilotinib titriert. Die Ergebnisse zeigen, dass BaF3-BCR/ABL einen Wachstumsvorteil im Minimalmedium hat, welcher im Standardmedium nicht vorliegt. Während die bereits bekannte Verstärkung der Glukoseaufnahme durch BCR/ABL im Standardmedium bestätigt wurde, konnte im Minimal-medium Gegenteiliges gezeigt werden. Zudem wurde ein Unterschied im Aminosäurestoff-wechsel zwischen BaF3 + IL-3 und BaF3-BCR/ABL + IL-3 im Minimalmedium deutlich. Die therapeutische Relevanz des gezeigten Einflusses der Nährstoffrestriktion konnte anschlie-ßend in der Tyrosinkinaseinhibitortitration dargestellt werden, da die Medikamente in Abhän-gigkeit vom Medium unterschiedliche Wirkungen zeigen. Insgesamt bieten die Ergebnisse einen metabolischen Erklärungsansatz für das Überleben von Tumorstammzellen in nährstoffarmen Arealen des Knochenmarks unter Therapie und Raum für neue Therapieansätze.

No description available.

In this thesis I describe an investigation into the function of the protein Icb-1, a homologue of Themis1 in B cells and monocytes. Themis1 is important for T cell positive and negative selections. Yet its function in T cell development is not clear. Although it shows characteristics of an adaptor protein and involvement in TCR-induced signalling, the exact signalling defects in Themis1-/- T cells remain obscure. Icb-1 is similar to Themis1 in sequence, function and binding partners. It has been studied in human tumour and macrophage cell lines, leading to limited conclusions. Its role in B cells has never been published. Given the link with Themis1, it is of great interest to investigate the function of Icb-1. My study has been focused on the comparison between Icb-1 knockout mice with wild-type controls. I characterised the B cell development in Icb-1-/- mice, either naturally born or produced as mixed adult bone marrow chimeras reconstituted from WT and Icb-1-/- donor cells. I examined the possible compensation and redundancy of Themis1 and Icb-1, by characterising Thems1/Icb-1 double knockout mice. The Ig-HEL mouse models were used to examine the change in B cell repertoire due to negative and positive selections. The mice were challenged with SRBCs or NP-CGG to examine the germinal centre response to foreign antigen when Icb-1 is absent. In vitro stimulation of B cells with soluble and membrane-bound antigens was used to investigate early B cell responses in detail and to give insights into the defects found in in vivo challenges. Finally, I examined the BCR-induced phosphorylation of key signalling molecules and Ca2+ flux in splenic B cells. The study revealed largely normal B cell development with subtle selection impairments, but a partially defected B cell immune response to antigens in Icb-1-/- mice. The marginal zone B cell population was enlarged in the absence of Icb-1, while the positive selection of B1 B cells induced by intracellular self-antigen was impaired. The deficient mice showed a reduction in germinal centre B cell generation. The defects are associated with impaired BCR-induced cell signalling to low abundance and/or low avidity antigens. In particular, Ca2+ flux and Erk1/2 phosphorylation were clearly reduced under certain conditions. The results shine a light on the function of protein Icb-1, and also improve our knowledge of Themis1 and the Themis family. They provide a new avenue of investigation into the regulation of BCR signalling, especially in Ca2+ flux induction and Erk1/2 activation. They also provide insight into how differential signalling is controlled within cells during activation and differentiation in response to antigens that vary in terms of affinity, avidity and frequency.