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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
471

Quantificação de danos em DNA induzidos por acetaldeído. Potencial biomarcador de poluição ambiental / Quantification of DNA damage induced by acetaldehyde. Potential biomarker for environmental pollution

Camila Carrião Machado Garcia 21 June 2010 (has links)
O acetaldeído é um comprovado agente mutagênico e carcinogênico, pode ser produzido endogenamente pela oxidação do álcool ingerido em bebidas alcoólicas e alimentos ou exogenamente, inalado como poluente, advindo da oxidação de combustíveis fósseis e etanol. O efeito do acetaldeído foi avaliado em modelos celulares e animais com o propósito de avaliarmos o aumento do estresse oxidativo, por lipoperoxidação, fragmentação do DNA, e a formação de adutos DNA, tais como 8-oxo-7,8-dihidro-2-desoxiguanosina, além de, 1,N2-eteno-2-desoxiguanosina e 1,N2-propano-2-desoxiguanosina que foram analisados por HPLC acoplado a espectrometria de massa com a utilização de metodologia ultra-sensível e reprodutiva. O tratamento de fibroblastos pulmonares humanos normais (IMR-90) com diversas concentrações de acetaldeído (58 µM a 711 µM) resultou em aumentos de morte celular, lipoperoxidação, fragmentação do DNA, cálcio intracelular e adutos de DNA. O efeito protetor do licopeno (20 µM) foi comprovado minimizando todos os efeitos deletérios promovidos pelo acetaldeído. O tratamento dos ratos Wistar por 8 e 30 dias com 150 mg/kg e 60 mg/kg via intra-peritoneal ou gavage, evidenciaram os efeitos tóxicos provocados pelo acetaldeído, como aumento significativo de lipoperoxidação, adutos e fragmentação de DNA no fígado e cérebro destes animais. A detecção dos adutos de DNA se mostrou uma ferramenta importante para a detecção dos efeitos provocados por exposição ao aldeído. No tratamento de animais por inalação com variadas concentrações de acetaldeído, que expôs os animais a quantidades do aldeído similares às encontradas em atmosferas poluídas, foi observado aumento de lipoperoxidação, sendo este dose dependente no fígado e pulmão. Já no cérebro, os níveis de MDA foram significativamente maiores em 10 ppb e 30 ppb em relação a 0 ppb e controle, e diminuíram significativamente em 90 ppb. Em relação aos níveis de fragmentação do DNA, observamos no pulmão aumento foi dose dependente em relação à concentração de aldeído. A quantificação de 1,N2-εdGuo e 1,N2-propanodGuo mostrou aumentos de ambos os adutos no pulmão de todos animais expostos ao acetaldeído . No fígado, também, foram detectados aumentos nos níveis de 1,N2-propanodGuo. A formação de 8-oxo-7,8-dihidro-2-desoxiguanosina, 1,N2-eteno-2-desoxiguanosina e 1,N2-propano-2-desoxiguanosina na urina de moradores da cidade de São Paulo, também foi investigada, com o desenvolvimento de metodologia ultra-sensível e reprodutiva por HPLC e espectrometria de massa, que indicou a presença dos três adutos nas urinas analisadas. A detecção do 1,N2-propanodGuo na urina é inédita. Nossos resultados comprovam que o acetaldeído é um forte agente citotóxico e genotóxico, mesmo em concentrações muito baixas, podendo contribuir para o esclarecimento dos mecanismos de desenvolvimento de doenças atribuídas ao aldeído, como o câncer. Além disso, o desenvolvimento de metodologias ultra-sensíveis para detecção e quantificação de adutos na urina e DNA isolado contribui para o emprego destes adutos, em especial o 1,N2-propano- 2-desoxiguanosina, como possível biomarcador de exposição ao acetaldeído presente em atmosferas poluídas e em patologias associadas ao estresse redox e abuso de bebidas alcoólicas. / Acetaldehyde is a known mutagen and carcinogen that can be produced endogenously by ethanol oxidation or directly inhaled as an air pollutant produced by fuel oxidation. The toxicity of acetaldehyde was evaluated in vitro and in vivo models, by means of oxidative stress parameters such as lipid peroxidation (measured as malonaldialdehyde -MDA), DNA fragmentation and DNA adducts such as 8-oxo-7,8-dihydro-2-desoxiguanosine, 1,N2-eteno-2-desoxiguanosine and 1,N2-propano-2-desoxiguanosine, this adducts were analyzed by an ultra-sensible and reproducible HPLC coupled to mass spectrometry assay. Treatment of human normal fibroblast (IMR-90) with a wide range of concentrations (58 µM to 711 µM) resulted in an increase in citotoxicity, lipid peroxidation, DNA fragmentation, intracellular calcium release and DNA adducts. Furthermore, lycopene (20 µM) presented a protective effect against the cellular deleterious properties of acetaldehyde. Treatment of Wistar rats for 8 and 30 days with 150 mg/kg and 60 mg/kg intra-peritonially or by gavage resulted in increased toxicity, measured by lipid peroxidation and DNA damage in liver and brain. The detection of DNA adducts was shown an important tool for the identification of deleterious effects induced by exposure to the aldehyde. Animals treated by inhalation, of amounts commonly found in polluted air samples, presented increased levels of lipid peroxidation in a dose dependent manner in liver and lungs. Nevertheless, in the brain of those animals the higher concentration was devoid of toxic effect measured as MDA levels. Lung tissue presented increased levels of DNA fragmentation. Furthermore, increased levels of 1,N2-εdGuo and 1,N2-propanodGuo was also observed in lungs of all animals. In DNA from livers, 1,N2-propanodGuo presented increased levels. Formation of 8-oxo-7,8-dihydro-2-desoxiguanosine, 1,N2-eteno-2-desoxiguanosine and 1,N2-propano-2-desoxiguanosine in urine samples of people living in the city of São Paulo were also investigated using a newly developed and ultra-sensible methodology base in HPLC coupled to mass spectrometry. This methodology enabled us to detect, for the first time, the presence of 1,N2-propanodGuo in urine samples. In summary, our results demonstrate the acetaldehyde is a strong cytotoxic and genotoxic agent even at low concentrations, being able to contribute to the development of pathology such as cancer. Furthermore, the development of a very ultra-sensitive methodology for the detection of these adducts, mainly ,N2-propano- 2-desoxiguanosine, enables its use as a possible biomarker of acetaldehyde exposure in polluted air samples and in pathologies associated with redox unbalance and ethanol consumption.
472

Citomegalovírus, herpesvírus humano 6, herpesvírus humano 7 e perfil imunofenotípico do infiltrado inflamatório na periodontite crônica marginal / Cytomegalovirus, human herpesvirus 6, human herpesvirus 7 and immunophenotypic profile of inflammatory infiltrate in marginal chronic periodontitis

Thomasini, Ronaldo Luís, 1978- 11 April 2011 (has links)
Orientador: Sandra Cecília Botelho Costa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T10:22:52Z (GMT). No. of bitstreams: 1 Thomasini_RonaldoLuis_D.pdf: 2991233 bytes, checksum: 570abfb75508069faffb192f2c6c5dcd (MD5) Previous issue date: 2011 / Resumo: Periodontite humana crônica é um processo inflamatório caracterizado por denso acúmulo de células imunes no tecido periodontal. A periodontite pode levar a perda do dente no paciente e a patogênese desta doença não é completamente conhecida. Este estudo testou a hipótese de que as células do infiltrado inflamatório podem abrigar betaherpesviruses e estes vírus estão ligados á subpopulação específicas de linfócitos. Fragmentos de tecido periodontal foram obtidas de pacientes afetados por periodontite e de indivíduos saudáveis. Imuno-histoquímica foi realizada para a contagem de células CD19+, céulas CD3+ e células CD4+ e CD8+. Reação em cadeia da polimerase e imuno-histoquímica foram realizados para detectar citomegalovírus, herpesvirus humanos 6 e 7 nas amostras. Como esperado, os tecidos coletados de indivíduos saudáveis não apresentaram nível significativo de infiltrado inflamatório e, portanto, foram excluídos dos procedimentos de imunofenotipagem. Os resultados mostraram que células CD19+ foram discretamente predomiantes sobre as células CD3+ no tecido periodontal afetado, mas estatisticamente não significativo. A subpopulação CD4+ de linfócitos estava significativamente em maior número que a subpopulação CD8+ de linfócitos (P=0,004), nas amostras. Citomegalovírus e herpesvírus humano 7 foram encontrados em locais afetados, mas não no tecido coletado de indivíduos saudáveis (P=0,04 e P=0,04, respectivamente). Herpesvirus humano 6 foi raramente detectado. Foi encontrado correlação entre citomegalovírus com menor relação de CD19+/CD3+ (P=0,003) e herpesvirus humano 7 com menor relação CD19+/CD3+ (P=0,003) e maior relação de CD4+/CD8+ ( P=0,002). Imuno-histoquímica foi negativa para citomegalovírus, herpesvirus humano 6 e herpesvirus humano 7 em todas as amostras. Este estudo mostra que citomegalovírus e herpesvírus humano 7 podem estar presentes em regiões afetadas pela periodontite, mas são incomuns em regiões saudáveis. Além disso, este estudo sugere que citomegalovírus pode ser relacionado ao infiltrado inflamatório, com predomínio de células CD3+ e, herpesvirus humano 7 pode estar relacionado ao infiltrado inflamatório com predomínio de células CD4+. Os dados sugerem que citomegalovírus e herpesvírus humano 7 podem estar presentes no infiltrado inflamatório, em estado de latência. No entanto, outros métodos deveriam ser realizados para confirmar esta hipótese / Abstract: Human chronic periodontitis is an inflammatory process characterized by dense accumulation of immune cells in the periodontal tissue. The periodontitis can lead to loss of teeth in the patient and the pathogenesis of this disease is not completely known. This study tested the hypothesis that cells within inflammatory infiltrate can harbor betaherpesviruses and these viruses are linked to specific lymphocyte subpopulation. Biopsies of periodontal tissue were taken from periodontitis affected and from healthy subjects. Immunohistochemistry was performed to count CD19+ cells, CD3+ cells, CD4+ and CD8+ cell subsets. Polymerase chain reaction and immunohistochemistry were performed to detected cytomegalovirus, human herpesvirus 6 and 7 in the samples. As expected, tissues collected from healthy subjects presented no significant level of inflammatory infiltration and therefore were excluded from immunostaining procedures. The results showed that CD19+ cells had discrete predominance over CD3+ cells in the periodontitis affected tissue but not statistically significant. CD4+ lymphocyte subset were significantly higher then CD8+ lymphocyte subset (P=0.004) in the samples. Cytomegalovirus and human herpesvirus 7 were found in affected sites but not in tissue collected from healthy subjects (P=0.04 and P=0.04, respectively). Human herpesvirus 6 was rarely detected. We found a correlation between cytomegalovirus with lower CD19+/CD3+ ratios (P=0.003) and human herpesvirus 7 with lower CD19+/CD3+ ratio (P=0.003) and higher CD4+/CD8+ ratios (P=0.002). Imunohistochemistry was negative for cytomegalovirus, human herpesvirus 6 and human herpesvirus 7 in the total of samples. This study shows that cytomegalovirus and human herpesvirus 7 can be present in periodontitis affected sites but are uncommon in healthy sites. Moreover, this study suggests that cytomegalovirus can be related to inflammatory infiltrate with predominance of CD3+ cells and, human herpesvirus 7 can be related to inflammatory infiltrate with predominance of CD4+. The data suggest that cytomegalovirus and human herpesvirus 7 could be present in the inflammatory infiltrate in latent state. However, different methods should be performed to confirm this hypothesis / Doutorado / Ciencias Basicas / Doutor em Clínica Médica
473

Estudo do IL-7R na leucemia linfóide aguda pediátrica de linhagem T / Study of IL-7R in chilldhood T-cell acute lymphoblastic leukemia

Zenatti, Priscila Pini, 1981- 19 August 2018 (has links)
Orientadores: José Andrés Yunes, Jorg Kobarg / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T20:56:25Z (GMT). No. of bitstreams: 1 Zenatti_PriscilaPini_D.pdf: 14781518 bytes, checksum: 2324b48b89768b42bcd5bf002d30a510 (MD5) Previous issue date: 2012 / Resumo: A IL-7 é uma citocina essencial para o desenvolvimento, sobrevivência, e proliferação dos timócitos prematuros normais no timo e linfócitos T maduros nos órgãos linfoides periféricos. O receptor da IL-7 é um heterodímero constituído pela IL-7Ra (codificado pelo gene IL7R) e IL-2Ry. A IL-2Ry participa também dos receptores da IL-2, IL-4, IL-9, IL-15 e IL-21, sendo por isso conhecida como cadeia comum gama ou yc. A sinalização via IL-7 é imprescindível para o processo de rearranjo V(D)J dos receptores de células T (TCR), pois leva à modificação da cromatina que permite o acesso da recombinase aos loci TCR no DNA Camundongos defeituosos para a cadeia alfa do receptor da IL-7 (IL-7Ra) desenvolvem imunodeficiências devido à falta de células T. A via IL-7/IL-7Ra é também importante para proliferação e sobrevivência da leucemia linfóide aguda de células T (LLA-T). Suspeitando da existência de mutações em IL7R resultando em ganho de função e hiperativação da via IL-7/IL-7Ra, procurou-se por mutações no gene do IL-7Ra em mais de 50 casos de LLA-T pediátrica. Procurou-se também mutações no domínio de autoinibição das JAK1 e JAK3, moléculas associadas ao IL-7Ra e IL-2Ry, respectivamente. Aproximadamente 9% das LLA-T pediátricas apresentaram mutações no IL-7Ra, resritas a uma região estreita do éxon 6, que resultaram, na maioria dos casos, em inserções de uma cisteína no domínio transmembrana/justamembrana da proteína. A presença dessa cisteína leva à homodimerização das cadeias IL-7Ra mediante a formação de pontes de dissulfeto e à ativação constitutiva do IL-7Ra independente de seu ligante, conforme verificado pela fosforilação de JAK1, STAT5, AKT e BAD e análise de mutantes artificiais do IL-7Ra com subtração ou adição de resíduo de cisteína. Verificou-se também que o local de inserção da cisteína é crítico para que a homodimerização das cadeias IL-7Ra mutantes resulte em ativação da via JAK/STAT. Receptores imitados tiveram um efeito transformante nas linhagens celulares Dl e Ba/F3, que sobreviveram na ausência dos fator de crescimento IL-7 e IL-3, respectivamente. Além disso, células Dl transduzidas com IL7R mutante, quando injetadas em camundongos knockout (KO) para IL7, causaram esplenomegalia, metástase e tumor no local da injeção. Resultados semelhantes foram obtidos com a expressão ectópica do IL7R mutante em células progenitoras hematopoiéticas de camundongos knockout para IL7R, JAK3 e/ou IL2RG, demonstrando que o homodímero IL-7Ra mutante atua independentemente dessas moléculas. Em conclusão, mutações no IL7R contribuem para a leucemogenese em 9% das crianças com LLA-T. Espera-se que a melhor caracterização do mecanismo responsável pela ativação constitutiva do IL-7Ra mutante abra caminho para o desenho de novas drogas e anticorpos monoclonais, o que permitirá avaliar o valor terapêutico do bloqueio/inibição do IL-7Ra mutante nas LLA-T / .Abstract: The IL-7, a product of stromal cells, is normally required for T cells development and for survival of mature peripheral T cells. The IL-7R consists of two components, the IL-7Ra (encoded by IL7R) and the common gamma chain (yc), or IL-2Ry, that is shared by receptors for IL-2, IL-4, IL-9, IL-15 and IL-21. The IL-7 signaling has a role in V(D)J recombination in developing T and B cells by controlling access of the V(D)J recombinase to the locus. IL-7Ra deficiency mice showed a diminished T cell number and impaired lymphocyte development. Further, the IL-7/IL-7Ra pathway is important for T-acute lymphoblastic leukemia (T-ALL) proliferation and survival. Hypothesizing that IL7R gain-of-function mutation could be occurring in T-ALL, 50 T-ALL samples were analyzed for mutations. The kinases JAK1 and JAK3, mat are associated with IL-7Ra and yc, respectively, were also studied for mutations. About 9% of childhood T-ALL presented mutations at the transmembrane domain encoded by éxon 6, and all of mem were in-frame insertions and deletions. In all but three cases there was an insertion of cysteine mat is essential for disulfide bond formation and constitutive activation of the receptor independent of IL-7. The constitutive signaling was confirmed by phosphorylation of JAK1, STAT5, AKT and BAD, and analysis of IL-7Ra artificial mutants with or without cysteine. The position of cysteine insertion is very important to disulfide bond formation, to activate the JAK/STAT pathway and to support the proliferation of Ba/F3 and Dl cell lines in the absence of cytokine. Moreover, IL7R mutant transduced Dl cells injected into ILT1' mice caused splenomegaly, metastasis and tumor at the injection site. Similar results were obtained with the ectopic expression of the IL7R mutant in hematopoietic progenitor cells of IL7K1', JAK3'1' and/or IL2RG'1' mice, demonstrating that the mutant homodimer IL-7Ra operates independently of these molecules. In conclusion, mutations in ÚÍQIL7R contribute to leukemo genes is in 9% of children with ALL-T. We hope mat a better comprehension of the mechanism responsible for the constitutive activation of IL-7Ra mutant opens new perspectives into the design of new drugs and monoclonal antibodies, which may turn into valuable therapeutic treatment / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular
474

Die Bedeutung von GD3-7-Aldehyd als Apoptosemediator und Oberflächenantigen

Röber, Nadja 25 July 2017 (has links) (PDF)
Glycosphingolipide sind eine Gruppe von amphiphatischen Membran- und Strukturlipiden, welche aus einem Molekül des Aminoalkohols Sphingosin oder einem seiner Derivate, einer langkettigen Fettsäure und einem Kohlenhydratrest als polare Kopfgruppe zusammengesetzt sind. Eine Subgruppe dieser Substanzen stellen die Ganglioside dar, welche durch das Vorkommen von Sialinsäure als Bestandteil ihrer Glykankette charakterisiert sind. Das Gangliosid GD3 ist als tumorassoziiertes Antigen auf der Oberfläche neuroektodermaler Tumore sowie als proapoptotisch wirkender Lipidmediator beschrieben. Seine biologischen Funktionen und der genaue Wirkmechanismus im Rahmen der Apoptose sind bisher aber unbekannt. Es gibt jedoch Hinweise, dass nicht GD3 selbst, sondern sein oxidiertes Derivat das eigentliche Effektormolekül darstellt. Eine minimale Veränderung des GD3-Moleküls, die 9-O-Acetylierung der Seitenkette der terminalen Sialinsäure, hebt die proapoptotische Wirkung des Gangliosids auf. Tumorzellen, in denen das Enzym 9-O-Acetyltransferase aktiv ist, können der Apoptose auf diese Weise entgehen. Das Anliegen dieser Arbeit war es, Vorkommen und Funktion des bis dahin nur artifiziell generierten oxidierten GD3-Derivates zu untersuchen. Es war zu analysieren, welche Auswirkungen oxidiertes GD3 auf das Überleben von GD3-resistenten Tumorzellen hat. Es sollte geprüft werden, ob GD3-7-Aldehyd in Primärzellen und Geweben auftritt. Dabei war zu klären, ob das Molekül unter Bedingungen des oxidativen Stresses entstehen und auf der Zelloberfläche oder intrazellulär induziert werden kann. Daraus folgernd sollte betrachtet werden, welche neuen immunologischen Therapieansätze zur Behandlung resistenter Tumore unter Nutzung von GD3-7-Aldehyd möglich wären. Voraussetzungen für die Experimente dieser Arbeit und für nachfolgende Forschungsfragen sind zuverlässige Nachweismöglichkeiten der Metabolite GD3, 9 O-acetyl-GD3 und GD3-7-Aldehyd. Während für den Nachweis von GD3 und 9 O acetyl-GD3 bereits monoklonale Antikörper zur Verfügung standen, war für die Detektion von GD3-7-Aldehyd im Rahmen dieser Arbeit erstmals ein monoklonaler Antikörper gegen ein oxidiertes Gangliosid zu generieren und zu charakterisieren. Für die Selektion antikörperproduzierender Zellen musste dafür zunächst eine neue Screeningmethode etabliert werden. Für die Überprüfung des Bindungsverhaltens der gangliosidspezifischen Antikörper und für die Durchführung der Inkubationsversuche waren die Ganglioside GD3 und 9-O-acetyl-GD3 über mehrere Chromatographieschritte aus lyophilisierter Buttermilch zu isolieren und das oxidierte Derivat herzustellen. Dabei wurde erstmals die Reinigung von GD3-7-Aldehyd mit der HPLC durchgeführt. Der im Rahmen dieser Arbeit generierte monoklonale Antikörper 10C6 gehört der Immunglobulin-Subklasse IgG2a an und bindet an die oxidierte Form des Gangliosids GD3. Das von 10C6 erkannte Antigen ist eine Glycankette der Struktur Neu5Ac-8Neu5Ac-3Gal mit oxidierter terminaler Sialinsäure. Der Antikörper reagiert nicht mit reduzierten oder 9-O-acetylierten Gangliosidvarianten und weist eine höhere Sensitivität auf als die etablierten Antikörper zum Nachweis der beiden anderen GD3-Derivate. In der Arbeit wurde in vitro gezeigt, dass die oxidative Modifikation von GD3 zu GD3 7-Aldehyd unter Bedingungen des oxidativen Stresses entstehen kann. In der GD3-resistenten Zelllinie Molt-4 induziert die Substanz Apoptose. GD3-7-Aldehyd kommt daher als proapoptotisches Effektormolekül in Frage. Das von 10C6 erkannte Antigen kommt auf der Oberfläche von Monozyten einzelner Spender vor. Außerdem kann es auf der Oberfläche eines Teils der Blasten bei akuter myeloischer Leukämie gefunden werden. Andere Leukozyten des peripheren Blutes tragen diese Struktur nicht. GD3-7-Aldehyd kommt in den Tumorzelllinien HEp-2, HL60 und T47D vor. In Gewebeschnitten von humanem Mammakarzinom sowie fötaler Milz und fötalem Darm von Primaten fanden sich Hinweise auf Strukturen mit oxidativ modifizierter Sialinsäure, in Geweben adulter Primaten wurden diese nicht gefunden. Auf der Oberfläche von Melanomzelllinien wie Ma-Mel-11, Ma-Mel-95 und SK-Mel-23 vorkommendes GD3 kann durch Natriumperjodatbehandlung zu GD3-7-Aldehyd oxidiert werden. Durch UV-Bestrahlung kann auf der Oberfläche von HEp-2- und SK-Mel-23-Zellen eine mit dem Antikörper 10C6 detektierbare Struktur induziert werden. HL60-Zellen lassen sich durch extern zugeführten GD3-7-Aldehyd dekorieren, es bleibt auf ihrer Oberfläche bis zu 48 Stunden nachweisbar. Für einen immunologischen Tumortherapieansatz könnten sowohl das geringe Vorkommen des Antigens in gesunden Geweben als auch die Induzierbarkeit auf der Oberfläche bestimmter Tumorzellen nach lokaler Vorbehandlung sowie die Toxizität der Substanz von Nutzen sein. Ein passender spezifischer Antikörper liegt nun vor. Die im Rahmen dieser Arbeit etablierten Detektionssysteme können für weitere Untersuchungen auf dem Gebiet der Glycolipidforschung eingesetzt werden. / Glycosphingolipids are a group of amphiphatic membrane and structure lipids consisting of one molecule of the aminoalcohol Sphingosin or one of its derivatives, a long chain fatty acid, and a carbohydrate moiety as polar side chain. One subgroup of these substances are gangliosides, which are characterized by sialic acid as a component of their glycan chain. The ganglioside GD3 is described as tumor associated antigen on the surface of neuroectodermal tumors and as proapoptotic lipid mediator. Its biological functions as well as its mode of operation in the context of apoptosis still remain unclear. There are hints, that not GD3 itself, but an oxidized derivative represents the actual effector molecule. A minimal change in the GD3 molecule, the 9-O-acetylation of the side chain of the terminal sialic acid, abolishes the proapoptotic effect completely. Tumor cells with activity of the enzyme 9-O-acetyltransferase can escape from apoptosis like that. The request of this work was to investigate the occurrence and function of this so far solely artificially generated oxidized GD3 derivative. The impact of oxidized GD3 on the survival of GD3-resistant tumor cells had to be analyzed. It had to be examined, whether GD3-7-aldehyde occurs in primary cells and tissues. Withal it was to clarify, if the molecule occurs under conditions of oxidative stress and if it can be induced on the surface of cells or intracellularly. Following that, it was to contemplate which novel approaches of immunological therapies for the treatment of resistant tumors could be possible under the use of GD3-7-aldehyde. Prerequisite to all experiments of this work and for following research are reliable detection methods of the metabolites GD3, and GD3-7-aldehyde. Whereas for the detection of GD3 and 9-O-acetyl-GD3 monoclonal antibodies were already existing, for the detection of GD3-7-aldehyde a novel monoclonal antibody directed against an oxidized ganglioside had to be generated for the first time and had to be characterized. For the selection of antibody producing cells, a new screening method had to be established. For the examination of the binding behavior of the ganglioside specific antibodies and for the performance of the incubation assays the gangliosides GD3 and 9-O-acetyl-GD3 had to be isolated from lyophilized bovine buttermilk via several chromatography steps and the oxidized derivative had to be produced. In doing so, GD3-7-al was purified by HPLC for the first time. The monoclonal antibody 10C6 generated in the framework of this study is member of immunoglobulin subclass IgG2a and binds to the oxidized form of the ganglioside GD3. The antigen detected by 10C6 is a glycan chain with structure Neu5Ac-8Neu5Ac-3Gal with oxidized terminal sialic acid. The antibody does not react with reduced or 9-O-acetylated forms of the ganglioside GD3 and possesses a higher sensitivity than the antibodies, established for the detection of both other GD3 derivatives. In this work it is shown in vitro, that the oxidative modification of GD3 to GD3-7-aldehyde can arise under conditions of oxidative stress. In GD3-resistant Molt-4-cells this substance induces apoptosis. Therefore GD3-7-aldehyde comes into consideration to be a proapoptotic effector molecule. The antigen detected by 10C6 occurs on the surface of monocytes of particular donors. Further, it can be found on the surface of a portion of the blasts of acute myeloic leukemia. Other leucocytes of the peripheral blood do not show this structure. GD3-7-aldehyde occurs in tumor cell lines HEp-2, HL60, and T47D. Hints for the existence of structures with oxidatively modified sialic acid were found in tissue slides of human mamma carcinoma and fetal gut. In tissues of adult primates this was not the case. On the surface of melanoma cell lines like Ma-Mel-11, Ma-Mel-95, and SK-Mel-23, existing GD3 can be converted into GD3-7-aldehyde by sodium periodate treatment. UV radiation can induce a structure detectable by 10C6 on the surface of HEp-2- and SK-Mel-23-cells. HL60-cells can be decorated by externally administered GD3-7-aldehyde. It is detectable on their surface for up to 48 hours. For an immunological approach of tumor therapy, the sparsely incidence of this antigen in healthy tissues as well as the inducibility on the surface of distinct tumor cells after pretreatment and the toxicity of this substance could be advantageous. A fitting antibody is now available. The detection methods established in the context of this work can be applied for further investigations in glycolipid research.
475

Etude du rôle de l'Ataxine-7 dans le développement de l'œil et son impact dans la compréhension des pathologies de l'œil et de l'ataxie spinocérébelleuse de type 7 / Role of Ataxin-7 in the development of vertebrate eye and its impact in the understanding of human eye pathologies and spinocerebellar ataxia type 7

Carrillo-Rosas, Samantha 30 October 2017 (has links)
L’ataxie spinocérébelleuse de type 7 (SCA7) est une maladie neurodégénérative à transmission autosomale dominante, causée par une expansion toxique de polyglutamine (polyQ) dans la protéine Ataxine-7. Elle se caractérise par une dégénérescence des photorécepteurs en cônes et en bâtonnets, ainsi que des cellules cérébelleuses de Purkinje et granuleuses. La nature sélective de cette dégénérescence reste peu claire, l’expression d’Ataxine-7 étant ubiquitaire. Dans ce contexte, nous avons exploré la fonction de l’orthologue d’Ataxine-7 chez le poisson-zèbre au cours du développement de l’œil. L’inactivation d’atxn7 chez le poisson-zèbre – par des approches utilisant des oligonucléotides anti-sens ou par CRISPR/Cas9 – résulte principalement en un colobome, malformation structurelle de l’œil causée par un défaut de fermeture de la fissure choroïde. Les morphants atxn7 présentent une altération du motif proximo-distal de la vésicule optique causée par une élévation de la signalisation Hedgehog (Hh). Une étude minutieuse des photorécepteurs révèle un défaut de la morphogénèse des segments externes. La sensibilité de l’œil aux variations de fonction d’atxn7 pourrait expliquer la phyiopathologie SCA7. Notre étude suggère également qu’une perte de fonction d’atxn7 contribuerait au développement du colobome chez l’Homme. / Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant neurodegenerative disorder caused by a toxic polyglutamine (polyQ) expansion in Ataxin-7 which leads to degeneration of cone and rod photoreceptors. The selective nature of degeneration remains unclear since Ataxin-7 is ubiquitously expressed. Here, we have explored the function of the Ataxin-7 ortholog in zebrafish during eye development. Inactivation of atxn7 in zebrafish primarily resulted in a coloboma defect, a structural malformation of the eye caused by failure of the choroid fissure to close. atxn7 morphants displayed altered proximo-distal patterning of the optic vesicle, caused by elevated Hedgehog (Hh) signaling. Careful examination of the photoreceptors reveals a defect in the morphogenesis of the outer segments. The eye sensitivity to variations in atxn7 function could account for SCA7 physiopathology. Our study also suggests that atxn7 loss of function may contribute to the development of human coloboma.
476

Personalização e adaptação de conteúdo baseadas em contexto para TV Interativa / Context-based content personalization and adaptation for Interactive TV

Rudinei Goularte 10 November 2003 (has links)
O trabalho apresentado nesta tese trata do desenvolvimento de técnicas com suporte à ciência de contexto, baseadas nos padrões MPEG-4 e MPEG-7, para personalizar e adaptar conteúdo em TV Interativa. Um dos desafios dessa área é desenvolvimento de programas personalizados com rico conteúdo multimídia, com alta interatividade e que, além disso, sejam acessíveis a partir de uma variedade de dispositivos (fixos ou móveis), atendendo às expectativas de interação e de acesso dos usuários. Grande parte do problema está no fato de que os modos encontrados na literatura para representar, descrever e compor programas de TV Interativa não oferecem suporte a contexto, não permitem a separação entre descrições de programas e descrições de objetos e possuem baixa granulosidade de segmentação. Essas características dificultam e, em alguns casos, impedem o desenvolvimento de aplicações avançadas em TV Interativa. As técnicas desenvolvidas neste trabalho são baseadas em esquemas de descrição, compatíveis com o padrão MPEG-7, e na segmentação de programas em objetos MPEG-4. Os esquemas são utilizados para descrever a estrutura, a composição e a semântica de programas e de seus objetos componentes. Também foi definida e implantada uma infra-estrutura para produção, distribuição e consumo de programas. A utilização conjunta da infra-estrutura e das técnicas permite o desenvolvimento de aplicações avançadas em TV Interativa. Como um exemplo dessas aplicações, foi desenvolvido um serviço automático para personalizar e adaptar programas de TV Interativa, permitindo que um usuário possa acessar, sob demanda, programas especialmente produzidos para ele, contendo apenas assuntos de seu interesse e permitindo que o acesso possa ser realizado por dispositivos fixos ou móveis. / The work presented in this thesis developed techniques with context-awareness support, based on the MPEG-4 and MPEG-7 standards, in order to personalize and to adapt Interactive TV content. One of the challenges in this area is the development of personalized programs with rich multimedia content, high interactivity and accessibility through a variety of devices (mobile and non-mobile). Most part of the problem is that the approaches found in literature do not provide context support, do not allow separation between programs and objects descriptions and have low level of segmentation granularity. These features make difficult or impossible, in some cases, the development of Interactive TV applications. The techniques developed in this work are based on MPEG-7 compliant schemes and on programs segmentation into MPEG-4 objects. The schemes are used to describe structure, composition and semantics of programs and component objects. An infra-structure to creation, delivery and consumption of Interactive TV programs was also defined. The joint utilization of infra-structure and techniques allows for the development of Interactive TV advanced applications. As an example of these applications, this work developed an automatic Interactive TV personalization and adaptation service. This service allows a user to access, on-demand, a program specially designed to match his interests and allowing content access through devices with mobile and non-mobile features.
477

Interactions between BMP-7 and USAG-1 (Uterine Sensitization-Associated Gene-1) Regulate Supernumerary Organ Formations / BMP-7とUSAG-1との相互作用による歯数制御に関する機能解析

Kiso, Honoka 24 September 2014 (has links)
Kiso H, Takahashi K, Saito K, Togo Y, Tsukamoto H, et al. (2014) Interactions between BMP-7 and USAG-1 (Uterine Sensitization-Associated Gene-1) Regulate Supernumerary Organ Formations. PLoS ONE 9(5): e96938. / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18545号 / 医博第3938号 / 新制||医||1006(附属図書館) / 31445 / 京都大学大学院医学研究科医学専攻 / (主査)教授 斎藤 通紀, 教授 戸口田 淳也, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
478

Gentrifikace v postsocialistickém kontextu střední Evropy. Komparativní případová studie - Varšava a Praha / Gentrification in the post-socialist context of Central Europe. Comparative case study - Warsaw and Prague

Novotný, Ondřej January 2018 (has links)
The thesis deals with the issue of gentrification in the post-socialist context of Central Europe. This phenomenon occurs mainly in the inner city districts, where the local social structure is disturbed through the physical upgrade of the neighborhood (e.g. flats, shops and restaurants) by pushing out the poorer layers of society by the more wealthy ones. In the cities marked by the communist urban planning, the inner city parts were neglected at the expense of peripheral prefab concrete buildings, thus creating great potential for local investment after the fall of the Iron Curtain. The process of gentrification is illustrated in this paper by the comparison of the two city districts Praga-Północ (Warsaw) and Prague 7 (Prague) in the time between 1989 and 2017. As a starting point for comparison, a special case of Prenzlauer Berg district in Berlin is used, where the process has shown significant impact already in the 1990s. In this respect the aim of the thesis is to investigate the links between Warsaw and Prague, also how these cases differ. At the same time, the role of the public sector is studied as a relevant factor influencing gentrification in the post-socialist region of Central Europe. The results of the study showed that analogous processes of gentrification appear in the Praga-Północ and...
479

Farmakologické ovlivnění neurologického deficitu u modelu fokální mozkové ischémie u potkana / Neurological deficit after focal cerebral ischemia in rat - pharmacological intervention

Eliášová, Karolína January 2020 (has links)
Title: Neurological deficit after focal cerebral ischemia in rats - pharmacological intervention Objectives: The goal of the thesis was to determine the effect of 7-nitroindazole, a selective inhibitor of neuronal nitric oxide synthase, after focal ischemic stroke in rats. Methods: Twenty adult male Wistar rats were used in this experiment. The rats were randomly divided into four groups: ischemic stroke was given to half of them, the rest were sham operated. 10 animals were given 7-nitroindazole (25mg/kg) to protect neuronal ischemic brain damage. After a few weeks the rats were tested with a set of behavioral tests: Ladder rung walking test, Bar holding test, Rotarod test and Open field test. To evaluate the volume of brain damage the stereotactic method was used. The brain sections were cut and compared with atlas. This study was supported by Institute of Physiology, Academy of Sciences ČR in Prague. Results: The present results show that the 7-nitroindazole has no side effects on healthy rats. The long-term effect on rats after ischemic stroke was not proved. There were a few positive trends observed such as an increase of locomotor speed, increased explorative behaviour and better coordination outcome on RotaRod. On the other hand the brain tissue damage was bigger and the time of hanging in...
480

Lobbying på IFRS 7 : En kvantitativ studie på 89 intressenter med avseende på argumentation / Lobbying on IFRS 7 : A quantitative study of 89 stakeholders in terms of argumentation

Al-Sabti, Amin, Johansson, Alexander January 2022 (has links)
Titel: Lobbying på IFRS 7: En kvantitativ studie på 89 intressenter med avseende på argumentation. Nivå: Examensarbete på grundnivå (kandidatexamen) i ämnet företagsekonomi.  Författare: Alexander Johansson och Amin Al-Sabti.  Handledare: Jan Svanberg. Examinator: Mats Landström. Datum: 2022-05-25. Syfte: Syftet med detta arbete är att undersöka om det finns ett samband mellan företag och antalet argument samt företagens användning av konsumtionsargument i kommentarsbreven. Detta i jämförelse med icke-företag och med avgränsning till implementeringen av IFRS 7.  Metod: Studien baseras på en deduktiv ansats med en applicering av en innehållsanalys. Studien har en kvantitativ strategi där 89 stycken avsändare av kommentarsbrev ligger till grund för studiens analyserade sekundärdata. Sekundärdata har bearbetats och analyserats i statistikprogrammet SPSS. Resultat och slutsats: Studiens resultat påvisar att det inte finns något samband mellan företag och antal argument i kommentarsbreven, vilket är i linje med tidigare forskning. Vi finner även att det saknas signifikant samband mellan företag och användningen av konsumtionsargument. Dessutom presenteras beskrivande data i den mån kommentarsbreven analyserats och kodats. Examensarbetets bidrag: Studien bidrar till företagsekonomiska forskningen via ämnesområdet lobbying då studien påvisar att det inte finns ett signifikant samband mellan företag och antal argument samt företag och konsumtionsargument i jämförelse med icke-företag inom kontexten IFRS 7. Studien bidrar även i kombination med tidigare forskning till ökad kunskap avseende argumentationen hos företag och icke-företag. Förslag till vidare forskning: Ett förslag till vidare forskning kan vara att utföra en liknande studie med avseende på metodiken men att analysera andra aspekter i kommentarsbreven och möjligtvis analysera andra standardsättningsprocesser. Nyckelord: Lobbying, IFRS 7, IFRS, IASB, argumentation, redovisningsstandarder. / Title: Lobbying on IFRS 7: A quantitative study of 89 stakeholders in terms of argumentation. Level: Degree project at the undergraduate level (Bachelor's degree) in the subject Business Administration.  Authors: Alexander Johansson och Amin Al-Sabti. Supervisor: Jan Svanberg. Examiner: Mats Landström. Date: 2022-05-25. Purpose: The purpose of this work is to investigate whether there is a connection between companies and the number of arguments and the companies' use of consumption arguments in the comment letters. This is in comparison with non-companies and with delimitation to the implementation of IFRS 7. Method:The study is based on a deductive approach with an application of a content analysis. The study has a quantitative strategy where 89 senders of comment letters form the basis for the study's analyzed secondary data. The secondary data has been processed and analyzed in the statistical program SPSS. Results and conclusion: The results of the study show that there is no connection between companies and the number of arguments in the comment letters, which is in line with previous research. We also find that there is no significant connection between companies and the use of consumption arguments. In addition, descriptive data are presented to the extent that the comment letters have been analyzed and coded. Contribution of the study: The study contributes to business economics research via the subject area lobbying as the study shows that there is no significant relationship between companies and number of arguments as well as companies and consumption arguments in comparison with non-companies in the context IFRS 7. The study also contributes in combination with previous research to increased knowledge regarding the argumentation of companies and non-companies. Suggestions for further research: A proposal for further research may be to carry out a similar study regarding the current methodology but to analyze other aspects in the comment letters and possibly analyze other standard setting processes.  Keywords: Lobbying, IFRS 7, IFRS, IASB, argumentation, accounting standards.

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