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Cancer de la prostate résistant à la castration métastatique : utilisation des nouveaux traitements dans un contexte réel au QuébecLahcene, Halima 04 1900 (has links)
No description available.
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Desenvolvimento e fabricação de filmes ultra-finos, obtidos pela técnica layer-by-layer, para aplicações na entrega direcionada de fármacos e na captura seletiva de bio-marcadores / Development and fabrication of ultrathin films obtained by layer-by-layer, aiming targeted drug delivery applications and the selective capture of biomarkersRoberta Polak 14 August 2014 (has links)
O objetivo geral deste trabalho foi explorar a versatilidade de filmes multicamadas de polieletrólitos (PEM) e suas aplicações em sistemas de entrega de drogas e como filmes funcionais para aplicações biomédicas. Filmes PEM montados pela técnica de camada por camada (layer-by-layer, LbL), foram explorados em três aplicações principais. Na primeira, foi explorado o desenvolvimento de um protocolo de funcionalização em filmes de poli(alilamina)/poli (estireno sulfonato), PAH/SPS. Os parâmetros de construção do filme para biotinilação dos grupamentos amina do PAH foram otimizados e aplicados na captura e detecção do antígeno específico da próstata (PSA), na concentração de 100 a 0,1 ng/mL, usando pontos quânticos (Qdots). Em comparação com outros trabalhos, este sistema apresentou uma boa sensibilidade na detecção de PSA, dentro do limite de detecção clínica de 0,4 a 0,1 ng/mL. A segunda aplicação envolveu o desenvolvimento de filmes de sacrifício baseados nas interações naturais da mucina submandibular bovina e da lectina, jacalina (BSM/JAC). Filmes de BSM/JAC apresentaram estabilidade quando submetidos a uma ampla faixa de pH (pH 3--9) e em solução de alta força iônica (5 M NaCl). A dissolução dos filmes BSM/JAC pôde ser seletivamente desencadeada mediante à incubação em solução de melibiose, 37 °C, pH 7,4, sem apresentar citotoxicidade às células. Na última parte deste trabalho, a incorporação de lipossomos ecogênicos (ELIP) em mochilas celulares foi investigada. Mochilas celulares são \"patches\" de 7-10 µm de diâmetro que podem ser fabricados por meio de deposição alternada de polímeros utilizando--se a técnica de LbL, sobre uma matriz pré-moldada obtida por fotolitografia, a fim de criar um sistema composto por três multicamadas estratificadas: uma região de liberação, para promover o destacamento do substrato, uma região de carga de droga, e uma região adesiva às células. O uso de ELIP permitiu incorporação de até 9x mais doxorrubicina (DOX) se comparado com o fármaco livre em solução absorvido pelos dos filmes. A liberação de DOX pelos filmes foi monitorado por 25 dias. Mochilas contendo ELIP-DOX foram então aderidos a monócitos, e sua viabilidade monitorados por 72h. Mochilas vazias mostraram diminuir a proliferação de monócitos ao longo das 72 horas, enquanto mochilas carregadas com ELIP-DOX mostraram uma diminuição dramática na população celular, apontando uma potencialização dos efeitos da droga pela sua proximidade com as células. / The overall goal of this thesis was to exploit the versatility of polyelectrolite multilayers (PEM) to be applied in drug delivery systems and biofunctionalizable films for biomedical applications. PEM films assembled by the layer-by-layer technique were explored in three main applications. In the first part of this work, the development of a functionalization protocol of poly(allylamine)/poly(styrene sulfonate), PAH/SPS was explored. The optimal film parameters to the use of biotinylated multilayers were applied for the capture and detection of prostate specific antigen (PSA) protein in the range of 100 to 0.1 ng/mL, by using quantum dots. Compared to previous work, this system presented a good sensitivity for PSA detection that is within the clinical limit range of 0.4 to 0.1 ng/mL. The second application involved the creation of a novel sacrificial multilayer film. Films based in natural interactions of bovine submaxillary mucin and the lectin jacalin, BSM/JAC were assembled. BSM/JAC films showed stability when underwent a wide rage of pH (pH 3 to 9) and high ionic strength (5 M NaCl) solutions. BSM/JAC dissolution could be triggered released by incubation in melibiose at 37 °C in pH 7.4 buffer, without cytotoxicity. In the last part of this work the incorporation of echogenic liposomes (ELIP) into cell backpacks was investigated. Cell backpacks are 7-10 µm diameter patches that can be fabricated through LbL polymer deposition onto a photopatterned array to create a stacked composite of three stratified multilayer systems: a releasable region for easy detachment from the substrate, a drug payload region, and a cell adhesive region. The use of ELIP allowed up to 9x more doxorubicin (DOX) loading when compared to free drug in solution adsorbed through the films. DOX release from films was monitored for over 25 days. ELIP-DOX backpacks were then attached to mouse monocytes and their viability monitored by 72h. Empty backpacks showed to decrease monocytes proliferation over the course of 72h, while ELIP-DOX backpacks showed a dramatic decrease in cell population, showing that DOX effects were enhancement in drug potency by its proximity.
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Escritores consagrados, ilustradores renomados, palavra e imagem entrelaçadas : ingredientes de contratos de comunicação literários renovadosMattos, Margareth Silva de 17 May 2017 (has links)
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Tese versão final Margareth Mattos.pdf: 12248873 bytes, checksum: 52f03d571242288d0da107fc56235306 (MD5) / Universidade Federal Fluminense, Colégio Universitário Geraldo Reis - COLUNI, Niterói, RJ / Esta pesquisa de caráter qualitativo e interdisciplinar vinculada à área de Estudos de
Linguagem tem como principal objetivo investigar os modos de renovação de diferentes
contratos de comunicação literários correspondentes às edições mais recentes de três
textos, dois do gênero conto – Conto de escola de Machado de Assis e De cima para baixo
de Artur Azevedo – e um do gênero crônica – Será o Benedito! de Mário de Andrade –,
produzidos entre o último quartel do século XIX e a primeira metade do século XX. Nessas
edições mais recentes, os textos exclusivamente verbais de autores-escritores brasileiros
canônicos transformam-se em textos híbridos verbo-visuais pelo trabalho dos autoresilustradores Nelson Cruz, Marcelo Ribeiro e Odilon Moraes, e pela iniciativa dos editores.
Com base nos pressupostos da Teoria Semiolinguística de Análise do Discurso, eixo
teórico-metodológico desta pesquisa, e, subsidiariamente, nos estudos dos paratextos
editoriais, na Semiótica da imagem visual, bem como nos estudos da interação palavraimagem no livro ilustrado e no livro com ilustração, pretende-se demonstrar como esses
textos, reeditados na primeira década do século XXI, com ilustrações de autoresilustradores brasileiros consagrados, integram contratos de comunicação literários que se
renovam. A hipótese é a de que a ocorrência de tal processo de renovação deve-se,
principalmente, à transformação dos textos verbais em textos híbridos verbo-visuais; à
redefinição dos parceiros iniciadores do processo de produção da encenação narrativa com
a inclusão dos autores-ilustradores; à redefinição dos parceiros do processo de
interpretação da encenação narrativa com a inclusão do leitor criança, em virtude de sua
inscrição nos textos híbridos como leitor destinatário, inscrição essa não prevista nos
contratos anteriores; à intensificação dos efeitos de sentido visados a partir tanto da
conformação dos paratextos editoriais, que constituem a mise-en-scène material e
discursiva dos livros correspondentes aos contratos de comunicação renovados, quanto da
interação entre as partes verbal e visual dos textos. Com isso, os livros correspondentes aos
contratos de comunicação literários renovados estariam identificados com a literatura de
potencial destinação infantil / This paper of qualitative and interdisciplinary nature linked to the area of Language
Studies has as its main objective the investigation of the renewal ways of different literary
contracts of communication corresponding to the most recent editions of three texts, two
short stories – Conto de escola by Machado de Assis and De cima para baixo by Artur
Azevedo – and one chronicle – Será o Benedito! by Mário de Andrade –, written between
the last quarter of the 19th century and the first half of the 20th century. In these most
recent editions, the exclusively verbal texts of canonical Brazilian writer-authors are
transformed into verbal-visual hybrid texts by the work of illustrator-authors such as
Nelson Cruz, Marcelo Ribeiro and Odilon Moraes, and by the editors’ initiative. Based on
the assumptions of the Semiolinguistic Theory of Discourse Analysis, which is the
theoretical-methodological framework of this investigation, and also based, in a subsidiary
way, on the studies of the editorial paratexts, on the Semiotics of the visual image, as well
as on the studies of the word-image interaction in picturebooks and in the book with
illustration, this paper intends to demonstrate how these texts, reprinted in the first decade
of the twenty-first century, with illustrations by acclaimed Brazilian illustrator-authors,
integrate literary contracts of communication that are renewed. The hypothesis is that the
occurrence of this renewal process is mainly due to the transformation of the verbal texts
into hybrid verbal-visual texts; the redefinition of the initiating partners of the production
process of the narrative staging by including the illustrator-authors; the redefinition of the
partners of the process of interpretation of the narrative mise-en-scène by including
children readers, because of their integration in the hybrid texts as target readers, a
hypothesis which was not incorporated in the previous contracts; the intensification of
meaning effects aimed at both the conformation of the editorial paratexts, which constitute
the material and discursive mise-en-scène of the books corresponding to the renewed
contracts of communication, and the interaction between the verbal and visual parts of the
texts. Thus, the books corresponding to the renewed literary contracts of communication
would be identified as literature potentially targeted for children readers
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Role of Mammalian RAD51 Paralogs in Genome Maintenance and Tumor SuppressionSomyajit, Kumar January 2014 (has links) (PDF)
My research was focused on understanding the importance of mammalian RAD51 paralogs in genome maintenance and suppression of tumorigenesis. The investigation carried out during this study has been addressed toward gaining more insights into the involvement of RAD51 paralogs in DNA damage signalling, repair of various types of lesions including double stranded breaks (DSBs), daughter strand gaps (DSGs), interstrand crosslinks (ICLs), and in the protection of stalled replication forks. My study highlights the molecular functions of RAD51 paralogs in Fanconi anemia (FA) pathway of ICL repair, in the ATM and ATR mediated DNA damage responses, in homologous recombination (HR), and in the recovery from replication associated lesions. My research also focused on the development of a novel photoinducible ICL agent for targeted cancer therapy. The thesis has been divided into following sections as follows:
Chapter I: General introduction that describes about DNA damage responses and the known functions of RAD51 paralogs across species in DNA repair and checkpoint
The genome of every living organism is susceptible to various types of DNA damage and mammalian cells are evolved with various DNA damage surveillance mechanisms in response to DNA damages. In response to DNA damage, activated checkpoints arrest the cell cycle progression transiently and allow the repair of damaged DNA. Upon completion of DNA repair, checkpoints are deactivated to resume the normal cell cycle progression. Defective DNA damage responses may lead to chromosome instability and tumorigenesis. Indeed, genome instability is associated with several genetic disorders, premature ageing and various types of cancer in humans. The major cause of chromosome instability is the formation of DSBs and DSGs. Both DSBs and DSGs are the most dangerous type of DNA lesions that arise endogenously as well as through exogenous sources such as radiations and chemicals. Spontaneous DNA damage is due to generation of reactive oxygen species (ROS) through normal cellular metabolism. Replication across ROS induced modified bases and single strand breaks (SSBs) leads to DSGs and DSBs, respectively. Such DNA lesions need to be accurately repaired to maintain the integrity of the genome.
To understand the various cellular responses that are triggered after different types of DNA damage and the possible roles of RAD51 paralogs in these processes, chapter I of the thesis has been distributed in to multiple sections as follows: Briefly, the initial portion of the chapter provides a glimpse of various types of DNA damage responses and repair pathways to deal with the lesions arising from both endogenous as well as exogenous sources. Owing to the vast range of cellular responses and pathways, the following section provides the detailed description and mechanisms of various pathways involved in taking care of wide range of DNA lesions from SSBs to DSBs. Subsequent section of chapter I provides a comprehensive description of maintenance of genome stability at the replication fork and telomeres. Germline mutations in the genes that regulate genome integrity cause various genetic disorders and cancer. Mutations in ATM, ATR, MRE11, NBS1, BLM and FANC (1-16), BRCA1 and BRCA2 that are known to regulate DNA damage signaling, DNA repair and genome integrity lead to chromosome instability disorders such as ataxia-telangiectasia, ATR-Seckel syndrome, AT-like disorder, Nijmegen breakage syndrome, Bloom syndrome, FA, and breast and ovarian cancers respectively. Interestingly, RAD51 paralog mutations are reported in patients with FA-like disorder and various types of cancers including breast and ovarian cancers. Mono-allelic germline mutations in all RAD51 paralogs are reported to cause cancer in addition to the reported cases of FA-like disorder with bi-allelic germline mutations in RAD51C and XRCC2. In accordance, the last section of the chapter has been dedicated to describe the genetics of breast and ovarian cancers and the known functions of tumor suppressors such as BRCA1, BRCA2 and RAD51 paralogs in the protection of genome.
Despite the identification of five RAD51 paralogs nearly two decades ago, the molecular mechanism(s) by which RAD51 paralogs regulate HR and genome maintenance remain obscure. To gain insights into the molecular mechanisms of RAD51 paralogs in DNA damage responses and their link with genetic diseases and cancer, the following objectives were laid for my PhD thesis:
1) To understand the functional role of RAD51 paralog RAD51C in FA pathway of
ICL repair and DNA damage signalling.
2) To dissect the ATM/ATR mediated targeting of RAD51 paralog XRCC3 in the
repair of DSBs and intra S-phase checkpoint.
3) To uncover the replication restart pathway after transient replication pause and the
involvement of distinct complexes of RAD51 paralogs in the protection of
replication forks.
4) To design photoinducible ICL agent that can be activated by visible light for
targeted cancer therapy.
Chapter II: Distinct roles of FANCO/RAD51C protein in DNA damage signaling and repair: Implications for Fanconi anemia and breast cancer susceptibility
RAD51C, a RAD51 paralog has been implicated in HR. However, the underlying mechanism by which RAD51C regulates HR mediated DNA repair is elusive. In 2010, a study identified biallelic mutation in RAD51C leading to FA-like disorder, whereas a second study reported monoallelic mutations in RAD51C associated with increased risk of breast and ovarian cancers. However, the role of RAD51C in the FA pathway of DNA cross-link repair and as a tumor suppressor remained obscure. To understand the role of RAD51C in FA pathway of ICL repair and DNA damage response, we employed genetic, biochemical and cell biological approaches to dissect out the functions of RAD51C in genome maintenance. In our study, we observed that RAD51C deficiency leads to ICL sensitivity, chromatid-type errors, and G2/M accumulation, which are hallmarks of the FA phenotype. We found that RAD51C is dispensable for ICL unhooking and FANCD2 monoubiquitination but is essential for HR, confirming the downstream role of RAD51C in ICL repair. Furthermore, we demonstrated that RAD51C plays a vital role in the HR-mediated repair of DSBs associated with replication. Finally, we showed that RAD51C participates in ICL and DSB induced DNA damage signaling and controls intra-S-phase checkpoint through CHK2 activation. Our analyses with pathological mutants of RAD51C displayed that RAD51C regulates HR and DNA damage signaling distinctly. Together, these results unravel the critical role of RAD51C in the FA pathway of ICL repair and as a tumor suppressor.
Chapter III: ATM-and ATR-mediated phosphorylation of XRCC3 regulates DNA double-strand break-induced checkpoint activation and repair
The RAD51 paralogs XRCC3 and RAD51C have been implicated in HR and DNA damage responses, but the molecular mechanism of their participation in these pathways remained obscured. In our study, we showed that an SQ motif serine 225 in XRCC3 is phosphorylated by ATR kinase in an ATM signaling pathway. We found that RAD51C in CX3 complex but not in BCDX2 complex is essential for XRCC3 phosphorylation, and this modification follows end resection and is specific to S and G2 phases. XRCC3 phosphorylation was found to be required for chromatin loading and stabilization of RAD51 and HR-mediated repair of DSBs. Notably, in response to DSBs, XRCC3 participates in the intra-S-phase checkpoint following its phosphorylation and in the G2/M checkpoint independently of its phosphorylation. Strikingly, we found that XRCC3 distinctly regulates recovery of stalled and collapsed replication forks such that phosphorylation was required for the HR-mediated recovery of collapsed replication forks but is dispensable for the recovery of stalled replication forks. Together, our findings suggest that XRCC3 is a new player in the ATM/ATR-induced DNA damage responses to control checkpoint and HR-mediated repair.
Chapter IV: RAD51 paralogs protect stalled forks and mediate replication restart in an FA-BRCA independent manner
Mammalian RAD51 paralogs RAD51 B, C, D, XRCC2 and XRCC3 are critical for genome maintenance. To understand the crucial roles of RAD51 paralogs during spontaneously arising DNA damage, we have studied the RAD51 paralogs assembly during replication and examined the replication fork stability and its restart. We found that RAD51 paralogs are enriched onto the S-phase chromatin spontaneously. Interestingly, the number of 53BP1 nuclear bodies in G1-phase and micro-nucleation which serve as markers for under replicated lesions increases after genetic ablation of RAD51C, XRCC2 and XRCC3. Furthermore, we showed that RAD51 paralogs are specifically enriched at two major fragile sites FRA3B and FRA16D after replication fork stalling. We found that all five RAD51 paralogs bind to nascent DNA strands after replication fork stalling and protect the fork. Nascent replication tracts created before fork stalling with hydroxyurea degrade in the absence of RAD51 paralogs but remain stable in wild-type cells. This function was dependent on ATP binding at the walker A motif of RAD51 paralogs. Our results also suggested that RAD51 paralogs assemble into BCDX2 complex to prevent generation of DSBs at stalled replication forks, thereby safeguarding the pre-assembled replisome from the action of nucleases. Strikingly, we showed that RAD51C and XRCC3 in complex with FANCM promote the restart of stalled replication forks in an ATP hydrolysis dependent manner. Moreover, RAD51C R258H mutation that was identified in FA-like disorder abrogates the interaction of RAD51C with FANCM and XRCC3, and prevents fork restart. Thus, assembly of RAD51 paralogs in different complexes prevents nucleolytic degradation of stalled replication forks and promotes restart to maintain genomic integrity.
Chapter V: Trans-dichlorooxovandium(IV) complex as a potent photoinducible DNA interstrand crosslinker for targeted cancer therapy
Although DNA ICL agents such as MMC, cisplatin and psoralen are known to serve as anticancer drugs, these agents affect normal cells as well. Moreover, tumor resistance to these agents has been reported. We have designed and synthesized a novel photoinducible DNA crosslinking agent (ICL-2) which is a derivative of oxovanadiumterpyridine complex with two chlorides in trans position. We found that ICL-2 can be activated by UV-A and visible light to enable DNA ICLs. ICL-2 efficiently activated FA pathway of ICL repair. Strikingly, photoinduction of ICL-2 induces prolonged activation of cell cycle checkpoint and high degree of cell death in FA pathway defective cells. Moreover, we showed that ICL-2 specifically targets cells that express pathological RAD51C mutants. Our findings suggest that ICL-2 can be potentially used for targeted cancer therapy in patients with gene mutations in FA and HR pathway.
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Nanoparticles functionalized with human antibodies for multimodal molecular imaging of atherosclerosis / Nanoparticules fonctionnalisées avec des anticorps humains pour l'imagerie moléculaire multimodale de l'athéroscléroseLarivière, Mélusine 19 December 2016 (has links)
L'athérosclérose, à l’origine de la plupart des maladies cardiovasculaires telles que l'infarctus du myocarde ou l'AVC, est la principale cause de décès dans le monde. Les cliniciens ont donc besoin de techniques d'imagerie fiables pour identifier les patients «vulnérables» porteur d’athérome à haut risque d'occlusion thrombotique. Cette pathologie est une maladie inflammatoire qui implique beaucoup d'acteurs cellulaires et moléculaires, parmi lesquels les cellules endothéliales et immunitaires, les lipoprotéines, les cellules apoptotiques et les plaquettes. L'imagerie moléculaire visant à détecter ces acteurs avant la survenue d'événements cardiovasculaires dramatiques est en plein essor. Des anticorps humains (HuAbs) sélectionnés par phage-display pour reconnaître des biomarqueurs de la pathologies ont ici proposés comme ligands servant à fonctionnaliser des vecteurs pour l'imagerie IRM, de fluorescence ou TEP. Les HuAbs ont été modifiés, en introduisant soit des Cystéines soit un site de reconnaissance pour la Sortase, afin de développer un greffage site-spécifique. Les agents ciblant ont été validés in vitro et ex vivo sur des coupes d'athérome de modèles animaux. Des résultats prometteurs ontété obtenus en injectant dans des souris ApoE-/- l’anticorps antiplaquettaire TEG4, apportant ainsi de nouvelles connaissances sur la biologie de l'athérome et la preuve de concept d'une possible détection des plaques à haut risque riches en plaquettes. Des améliorations sont en cours pour développer des agents de contraste multi-fonctionnalisés avec des HuAbs et permettant de réaliser une imagerie moléculaire multimodale de l'athérosclérose facilement transposable en clinique. / Because cardiovascular diseases are the leading cause of death in the world, providing clinicians with reliable and straightforward imaging techniques to identify "vulnerable" patients from the general population appears like the Holy Grail of the cardiovascular field. Atherosclerosis, identified as the underlying condition for most acute cardiovascular events, is characterized by the constitution of a lipidrich atheroma plaque, driven both by excess cholesterol and inflammation, which eventual rupture triggers clotting into the blood flow. It involves a wealth of cellular and molecular actors, which are so many potential markers for molecular imaging, aiming at deciphering how to warn clinicians about the possible occurrence of myocardial infarction or stroke. Here, human antibodies (HuAbs) selected by phage-display for their recognition of over-expressed biomarkers of the pathology are proposed as targeting ligands. They were further engineered for site-specific grafting, either by introducing Cysteine or Sortase recognition tags, and used to target contrast agents for MRI, fluorescence, or PET imaging. In vitro and ex vivo validation studies were carried out on atheroma sections of animal models. In vivo studies in the ApoE-/- mouse model were realized with the anti-platelet TEG4 HuAb using MRI, which provided insights on the biological relevance and feasibility to detect platelets-rich, high-risk atheroma plaques. The development of contrast agents useful in multi-modality imaging, and multi-functionalized with HuAbs is underway. It should serve as an accurate molecular imaging method for atherosclerosis, further more easily translated into the clinical arena.
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Répercussions psychosociales des symptômes dermatologiques induits par les thérapies ciblées anticancéreuses / Psychosocial impact of dermatologic side effects associated with anticancer targeted therapiesCharles, Cécile 05 June 2014 (has links)
Contexte - Considérées comme un progrès thérapeutique notable en cancérologie, les thérapies ciblées ne sont pas sans effet secondaire, en particulier sur le plan dermatologique. Très peu de données sont actuellement disponibles quant à leurs retentissements sur la qualité de vie des patients. Le service de dermatologie de Gustave Roussy a développé un protocole de recherche prospectif (SKINTARGET) consacré à cette thématique afin de pouvoir proposer des mesures préventives et/ou curatives adaptées. Inscrite dans ces travaux, notre thèse avait pour objectif principal de décrire les changements observés du point de vue de l’état émotionnel, de l’image corporelle et des interactions sociales avec l’apparition des atteintes cutanées, en s’intéressant à la place des représentations associées au traitement dans le processus d’ajustement des patients à ces symptômes.<p>Méthode - Il s’agissait d’une étude comprenant quatre temps d’évaluation (initiation du traitement, un, deux et trois mois après), qui associait de façon concomitante deux modes d’évaluation :quantitatif (questionnaires :IPQ-R, DLQI, POMS, BDI-II, QIC) et qualitatif (entretiens semi-directifs). L’inclusion était proposée par les oncologues aux patients allant débuter un traitement par thérapie ciblée. Les analyses statistiques ont été menées à partir du logiciel SPSS version 14.0 ;les analyses des entretiens ont combiné méthode thématique et méthode par questionnement analytique, en s’appuyant sur le modèle théorique de Pedinielli. <p>Résultats - Quatre-vingt-deux patients ont donné leur accord pour la recherche biomédicale, 62 d’entre eux ont accepté de participer à l’étude psychologique. La partie quantitative a été complétée par 33 patients, pour moitié hommes (âge moyen 56 ans), soignés pour un cancer métastatique cutané, pulmonaire, rénal ou thyroïdien. L’échantillon comptait une majorité de personnes en couple, avec enfants, soit à la retraite soit en arrêt de travail. Quatre-vingt-quatorze pour cent a développé au moins un des principaux symptômes suivants :rash cutané, syndrome main-pied, alopécie ou photosensibilité. Les changements observés ont été un inconfort physique et une gêne à la réalisation des activités du quotidien. Aucun signe de perturbation de la sphère émotionnelle, de l’image du corps et des relations sociales n’a été mis en évidence au cours des trois premiers mois de traitement. Les symptômes dermatologiques ont majoritairement été rattachés par les patients à l’action du traitement, sans être interprétés comme signes de son efficacité. La représentation d’un médicament contrôlant la maladie a émergé comme un des facteurs significativement associés aux variations de l’impact des toxicités cutanées sur la qualité de vie. <p>La partie qualitative a concerné 41 patients, dont les caractéristiques médicales et socio-démographiques étaient très similaires à celles de l’échantillon quantitatif. Pour une majorité les effets secondaires dermatologiques ont été « embêtants », « gênants », quelquefois « impressionnants », voire « perturbants » lorsqu’ils entraînaient douleurs, difficultés à la mobilité ou troubles du sommeil, mais sont restés « gérables, supportables ». Les représentations associées au traitement, très positives, sont apparues comme un élément soutenant dans l’ajustement des patients. Du discours des patients en souffrance psychologique sont ressorties une défiance vis-à-vis du regard d’autrui et une impossibilité d’amorcer le travail de renoncement nécessaire à l’intégration des transformations liées au cancer et à ses traitements. L’origine de cette souffrance serait un débordement des défenses psychiques par une angoisse de mort :la difficulté pour restaurer l’état d’équilibre psychique antérieur provenant de l’activation concurrentielle de deux dynamiques, l’une surnommée « substantielle », l’autre « identitaire ».<p>Discussion - Ces résultats rejoignent les données de la littérature en concluant à un impact d’intensité faible à modérée des toxicités cutanées sur la qualité de vie pour une majorité de patients. Contrairement à ce qui était attendu, il n’a pas été observé de changement sur le plan de l’état émotionnel, de l’image corporelle et des interactions sociales. L’investissement positif du traitement, la réappréciation des valeurs, le très bon état général des patients et l’optimisme ont été évoqués pour expliquer non seulement l’absence de perturbation, mais aussi les très bas niveaux d’anxiété, de tristesse et de fatigue globalement rapportés. L’importance de l’encadrement soignant et médical a également été soulignée parce qu’il sécurise les patients en anticipant les difficultés, en informant et en proposant une prise en charge suivie.<p>Conclusion - Le développement croissant des thérapies ciblées devrait s’accompagner d’un renforcement des mesures de prévention et de prise en charge des effets secondaires dermatologiques, qui requiert formation et sensibilisation des acteurs de soin à cette problématique, en rappelant la dimension singulière du vécu de chaque patient et l’impossibilité de le réduire à l’observable médical.<p>Background - Considered as a significant therapeutic progress in cancer, targeted agents are not without side effects, particularly dermatological ones. Very little information is presently available about their consequences on patients’ quality of life. The dermatological team of Gustave Roussy has developed a prospective research (SKINTARGET) in order to provide preventive and curative adapted care. Integrated into this work, our thesis aimed to describe the psychosocial changes occurring with cutaneous toxicities and to explore the implication of treatment representations in the patient’s adjustment process.<p>Methods - The study included four phases of evaluation (treatment initiation, one, two and three months after) and used simultaneously two methods: a quantitative one (questionnaires: IPQ-R, DLQI, POMS, BDI-II, BIQ) and a qualitative one (semi-structured interviews). The inclusion was proposed by oncologists to patients who were about to start a targeted therapy. Statistical analyzes were conducted with SPSS 14.0 software; analyzes interviews combined thematic approach and analytical questioning methods and referred to the Pedinielli’s theoretical model.<p>Results - Eighty- two patients gave their consent for biomedical research, 62 of them agreed to participate to the psychological study. The quantitative part was completed by 33 patients (50% men, mean age 56 years) treated for metastatic skin, pulmonary, renal or thyroid cancer, who were mostly in a relationship with children, either retired or stopped working. Eighty- four percent developed at least one of the following main symptoms: skin rash, hand-foot syndrome, alopecia or photosensitivity. The observed changes were characterized by a physical discomfort and difficulties in the activities of daily life. No sign of disturbance was noted in emotional domain, body image or social relations during the first three months of treatment. Dermatological symptoms were mainly related by patients to treatment action, without being interpreted as an evidence of its effectiveness. The representation of a drug controlling the disease was significantly associated with a lower impact of skin problems on the quality of life.<p>The qualitative part included 41 patients. Medical and sociodemographic characteristics were very similar to those of the quantitative sample. For most people, dermatological side effects were "boring", "uncomfortable", sometimes "impressive" or "disturbing" when they were associated with pain, mobility difficulties or sleeping troubles, but remained "manageable, bearable". The very positive treatment representations appeared as a supporting element in patients’ adjustment. Psychological distress seemed appear when patients feared being stared by others and failed to engage themselves in the renouncement work which is needed to adjust oneself to the transformations related to cancer and its treatments. In such situation psychological distress was supposed to come from an overflow of the psychic defences by a fear of death; the difficulty to restore mental balance would be explained by the activation of two competitive dynamics, which struggle for the organism and the identity survival.<p>Discussion - These results are consistent with the literature data. The skin toxicities impact on quality of life is mild to moderate for a majority of patients. Contrary to our expectations, there was no evidence of change in the domains of emotions, body image and social interactions. The positive investment of treatment, a reassessment of values, the very good physical state of patients and the influence of optimism in patients state of mind have been cited to explain not only the absence of disturbance, but also the very low levels of anxiety, sadness and fatigue generally reported. The importance of the caregiving provided by health professionals was also highlighted: anticipating difficulties, giving information about side effects and effectively managing problems secure patients.<p>Conclusions - The growing development of targeted therapies implies strengthening prevention and management of dermatological side effects. Moreover, it requires to aware and to train more health professionals to this problem, recalling the singular dimension of each patient which can not being reduced to the medical observable.<p> / Doctorat en Sciences Psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished
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Rôle de l'intégrine α5β1 dans la biologie du glioblastome et dans la résistance aux thérapies anti-EGFR / Role of alpha5beta1 integrin in glioblastoma b1ology and resistance towards anti-EGFR therapiesBlandin, Anne-Florence 06 November 2015 (has links)
Le glioblastome multiforme (GBM) est la tumeur cérébrale primaire la plus fréquente. Une dérégulation des voies de signalisation de l’EGFR et un fort potentiel invasif sont les caractéristiques principales du GBM. Malheureusement, les essais cliniques impliquant des thérapies anti-EGFR dans le traitement des GBM demeurent inefficaces. Nous avons précédemment montré que le récepteur de la fibronectine, l’intégrine α5β1, est associé avec un mauvais pronostic et une résistance des patients au temodal. Les intégrines peuvent coopérer avec les récepteurs aux facteurs de croissance et ainsi amplifier leur potentiel oncogénique. Ici, nous avons cherché à déterminer le rôle de l’intégrine α5 dans la résistance aux thérapies anti-EGFR. Utilisant la lignée U87 de GBM, on a dans un premier temps confirmé que l’activation de l’intégrine sous l’influence de la fibronectine, potentialisait la signalisation de l’EGFR. La perte d’expression d’α5 sensibilise les cellules U87 aux anti-EGFR (cetuximab, gefitinib) dans des essais de clonogénicité en soft agar. L’expression d’ α5 favorise la résistance aux 2 drogues lors de la migration cellulaire. Pour aller plus loin, nous avons développé un nouveau test basé sur la quantification de l’évasion cellulaire à partir d’une sphère tumorale. La perte d’ α5 augmente la sensibilité des cellules U87 à 2 TKI réversibles spécifiques de l’EGFR, gefitinib et erlotinib, mais n’a pas d’effet sur l’efficacité du lapatinib, un TKI irréversible ciblant EGFR, ErbB2, ErbB3 et ErbB4. Grâce à la microscopie confocale, nous avons montré l’effet important du gefitinib sur l’endocytose de l’intégrine et de l’EGFR. Ces résultats suggèrent que l’expression d’ α5 favorise la résistance aux TKI par l’activation des voies de signalisation des récepteurs ErbB ou en contrôlant le trafic membranaire de l’EGFR. On a aussi montré que pour favoriser l’adhésion cellulaire, l’intégrine α5 stimulait la fibrillogénèse. Dans les cellules migrant à distance de la sphère, l’intégrine α5 est strictement engagée dans des adhésions cellule-substrat contenant la protéine FAK activée. Nos résultats soulignent le rôle central du couple fibronectine/ intégrine α5 dans l’invasivité du GBM et la résistance aux thérapies anti-EGFR. / Glioblastoma multiforme (GBM) is the most common primary brain tumor. Alteration of the EGFR pathway and high invasive potential are hallmarks of GBM. Unfortunately, trials using anti-EGFR therapies for the treatment of GBM reveal limited efficacy. We previously showed that overexpression of the fibronectin receptor, α5β1 integrin, is associated with a poor prognosis for patients and is responsible for chemoresistance to temodal. Integrins can cross-talk with growth factor receptors and amplified their oncogenic activity. Here, we sought to determine the potential role of α5 integrin in resistance to anti-EGFR therapy. Using U87 GBM cell line, we first confirmed that fibronectin-mediated integrin activation potentiated EGFR signaling. Loss of α5 integrin expression sensitized U87 cells to anti-EGFR drugs (cetuximab, gefitinib) in soft agar clonogenic assay. α5 expression can trigger resistance to both drugs on cell migration. To go further, we developed a new assay based on the quantification of cell evasion from tumor spheroids. α5 depletion increased U87 cell sensitivity to gefitinib and erlotinib, 2 EGFR-selective reversible TKI, but had not effect on lapatinib efficacy, an irreversible TKI that target EGFR, ErbB2, ErbB3 and ErbB4. Confocal microscopy revealed a strong impact of gefitinib on EGFR and integrin endocytosis. These results suggested that α5 expression may trigger resistance to TKI either by activating ErbB pathways or by controlling EGFR membrane trafficking. We also showed that to promote cell adhesion, α5 integrin stimulated fibronectin fibrillogenesis. As cells moved away from the spheroids, α5 became strictly engaged in cell-substratum adhesion sites where it recruited activated FAK. Our work highlights the pivotal role of fibronectin/α5β1 integrin in invasivity of GBM and resistance to anti-EGFR drugs.
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Synthesis And Characterization of Cationic Lipids And Carbon Nanomaterials Based Composites for the Delivery Of Bioactive Oligo/Polynucleotides and Drugs In Vitro and In VivoMisra, Santosh Kumar January 2013 (has links) (PDF)
The biggest hurdle in success of gene and drug therapy is designing and preparation of suitable bio-nanomaterials to carry the desired nucleic acid and drug to the targeted site. The work described in the present thesis encompasses two different approaches for the delivery of bioactive oligo/polynucleotides and drugs in vitro and in vivo using either cationic lipids or their nanocomposites with different carbon nanomaterials. The idea of using carriers for oligo/polynucleotides and drugs came into existence because of numerous physiological barriers in pathway of delivery of naked oligo/polynucleotides or drugs which reduces the overall activity of these bioactives in biological systems. These barriers trigger scientific research toward the preparation of appropriate biomaterials which can overcome the physiological barriers and improve the activity of bioactive oligo/polynucleotides and drugs in cellular systems. Toward this end, the design and synthesis of different cationic lipids and carbon nanomaterials were undertaken as described in seven chapters of the thesis.
A series of novel cationic lipids with structural variability was prepared and used for gene delivery in vitro. They were further tuned chemically to sustain delivery efficiency in high serum percentage during in vitro transfection. These serum compatible lipids were used to perform transfection of reporter gene plasmid and found to be more efficient compared to the some well known commercial products for the same purpose.
Another series of novel lipids were synthesized for the targeted gene delivery in vitro. These tryptophan based cholesteryl lipids were used to prepare mixed liposomes. These mixed liposomes were highly efficient in targeting sigma receptor rich HEK293T over sigma receptor negative HeLa cells. Mixed liposomes were also prepared for selective targeting of αvβ3 and αvβ5 integrins in gene transfection protocol using a palmitoyl-RAFT-RGD4 template.
A mixed liposomal formulation was developed to carry out anti-sense siRNA mediated knockdown of Smad-2 protein with better efficiency compared to some of the best known commercial products for the same purpose. These mixed liposomes were also highly efficient for regression via induction of p53 mediated apoptosis in xenograft tumors developed in nude mice.
Carbon nanomaterials have been extensively explored as nanoscale gene/drug carriers for potential applications. But the challenge is to solubilize these highly hydrophobic materials in aqueous medium for use in biological systems. Although there are reports for covalent modifications of such nanomaterials but it could be done only with the loss of some beneficial features of these materials. Herein a non-covalent technique has been efficiently used to suspend single walled carbon nanotubes in water using biocompatible cationic lipids. These nanosuspensions were used to complex plasmid DNA and transfect them in vitro. They proved to be highly serum compatible DNA carriers which did not drop the efficiency even in very high percentage of serum. Similarly exfoliated graphene was modified with cationic lipid and serum components to improve IC50 of Tamoxifen citrate and Methotrexate to a considerable extent in vitro. The improved Methotrexate formulations were highly efficient for regression in size of xenograft tumors developed in nude mice.
Thus, the present thesis entails generation of cationic lipids and carbon nanomaterials based nanocomposites which were not only highly biocompatible themselves but their efficiency was found many fold better compare to some of the best commercial delivery agents. These were useful for the delivery of various bioactive oligo/polynucleotides and drugs in vitro and in vivo.
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Targeted Client Synthesis for Detecting Concurrency BugsSamak, Malavika January 2016 (has links) (PDF)
Detecting concurrency bugs can be challenging due to the intricacies associated with their manifestation. These intricacies correspond to identifying the methods that need to be invoked concurrently, the inputs passed to these methods and the interleaving of the threads that cause the erroneous behavior. Neither fuzzing-based testing techniques nor over-approximate static analyses are well positioned to detect subtle concurrency defects while retaining high accuracy alongside satisfactory coverage. While dynamic analysis techniques have been proposed to overcome some of the challenges in detecting concurrency bugs, we observe that their success is critically dependent on the availability of effective multithreaded clients. Without a priori knowledge of the defects, manually constructing defect-revealing multithreaded clients is non-trivial.
In this thesis, we design an approach to address the problem of automatically generate clients for detecting concurrency bugs in multithreaded libraries. The key insight underlying our design is that a subset of the properties observed when the defects manifest in a concur-rent execution can also be observed in a sequential execution. The input to our approach is a library implementation and a sequential testsuite, and the output is a set of multithreaded clients that can be used to reveal defects in the input library implementation. Dynamic defect detectors can execute the clients and analyze the resulting traces to report various kinds of defects including deadlocks, data races and atomicity violations. Furthermore, the clients can also be used by testing frameworks to report assertion violations.
We propose two variants of our design – (a) path-agnostic client generation, and (b) path-aware client generation. The path-agnostic client generation process helps in detection of potential bugs present in the paths executed by the input sequential testsuite. It does not attempt to explore newer paths by satisfying path conditions either by modifying the input or by scheduling the threads appropriately. The generated clients are used to expose deadlocks, data races and atomicity violations. Our analysis analyzes the execution traces obtained from executing the input sequential clients and produces a concurrent client program that drives shared objects via library methods calls to states conducive for triggering deadlocks, data races or atomicity violations.
For path-aware client generation, our approach explores newer paths that are not covered by the input sequential testsuite to generate clients. For this purpose, we design a directed, iterative and scalable engine that combines the strengths of static and dynamic analysis to help synthesize both multithreaded clients and schedules that violate complex correctness conditions expressed by the developer. Apart from the library implementation and the sequential testsuite as input, this engine also accepts a specification of correctness as input. Then, it iteratively refines each client from the input sequential testsuite to generate an ex-ecution that can break the input specification. Each step of the iterative process includes statically identifying sub-goals towards the goal of failing the specification, generating a plan toward meeting these goals, and merging of the paths traversed dynamically with the plan computed statically via constraint solving to generate a new client. The engine reports full reproduction scenarios, guaranteed to be true, for the bugs it finds.
We have implemented prototypes that incorporate the aforementioned ideas and validated them by applying them on 29 well-tested concurrent classes from popular Java libraries, including the latest version of JDK. We are able to automatically generate clients that helped expose more than 300 concurrency bugs including deadlocks, data races, atomicity violations and assertion violations. We reported many previously unknown bugs to the developers of these libraries resulting in either fixes to the code or changes to the documentation pertaining to the thread-safe behavior of the relevant classes. On average, the time taken to analyze a class and generate clients for it is less than two minutes. We believe that the demonstrated effectiveness of our prototypes in helping expose deep bugs in popular Java libraries makes the design, proposed in this thesis, a vital cog in the future development and deployment of dynamic concurrency bug detectors.
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Évaluation de l’approche métabolomique pour l’authentification des extraits naturels utilisés dans le secteur arômes et parfums / Metabolomics for the authentication of natural extracts used in flavour and fragrancesSaint-Lary, Laure 10 June 2015 (has links)
Certains extraits naturels sont très rares et onéreux. La tentation est alors forte pour les producteurs de matières premières ou intermédiaires d’avoir recours à des adultérations. Le mélange avec des extraits issus d’origines botaniques apparentées, d’origines géographiques différentes, l’ajout d’un composé synthétique présent dans l’extrait naturel ou d’un autre extrait végétal, l’utilisation de produits phytosanitaires réglementés, la mise en place de procédés d’extractions non standardisés, en sont quelques exemples. Ces différences de qualité sont de plus en plus difficilement décelables. Cette thèse a pour objet de mettre au point une méthodologie rapide, efficace et non ciblée. Une approche métabolomique en UHPLC-HRMS est développée pour identifier ces défauts ou pratiques frauduleuses pour les absolues destinées au secteur arômes et parfums. Cette mise en évidence est réalisée par la détection de métabolites marqueurs. Les absolues présentent un défi particulier : entre 50 et 95 % de l’extrait peut être constitué de composés non volatils, rarement décrits dans la littérature. La recherche d’authenticité de ces extraits est alors plus complexe que dans le cas d’un extrait volatil tel qu’une huile essentielle, dont la composition peut être plus facilement déterminée par des techniques analytiques éprouvées et l’utilisation de bases de données. Deux plantes emblématiques de la parfumerie ont été étudiées : la violette (Viola odorata) et la rose (Rosa damascena et Rosa centifolia). Des marqueurs d’origine géographique ont été identifiés dans le cas de la violette, et des marqueurs d’origine botanique dans le cas de la rose. / Some natural extracts are very scarce and expensive. The temptation is therefore very high for producers or brokers to resort to adulterations. Mixing of extracts from related botanical origins, from different geographical origins, addition of synthetic compounds with natural occurrence in the extract, or addition of another vegetal extract, use of phytosanitary products, non-standardized extraction processes, are some examples. The quality differences are more and more difficult to detect. The objective of this PhD study was to develop a fast, efficient and non-targeted methodology. Metabolomics approach in UHPLC-HRMS was developped to identify defects or fraudulent practices in absolutes used in flavour and fragrances. These identifications are realized by the detection of chemical markers. Absolutes are a great challenge: between 50 and 95 % of the extracts consist of non-volatile compounds; moreover these products are seldom described in literature. The quest for validation for authenticity is then much more complex than in cases of volatile extracts such as essential oils, whose composition can be more easily determined by robust analytical instruments and numerous databases. Two symbolic plants used in perfumery were studied: viola (Viola odorata) and rose (Rosa damascena and Rosa centifolia). Markers of French origin were identified for viola, and markers of R. centifolia were identified for rose. Their characterizations were nevertheless the fundamental limit for this technique being at trace level in the extract. This work demonstrated the performance and limitation of the non-targeted metabolomics approach on absolutes, which are specialties of perfumery.
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