Le Sarcome d'Ewing est un cancer pédiatrique rare, principalement dû à l'expression de l'oncogène de jonction EWS-Fli1, et dont les traitements médicamenteux ont peu évolué au cours des dernières décennies. Nous nous intéressons à une nouvelle approche thérapeutique utilisant des siRNA, ciblant spécifiquement l'oncogène EWS-Fli1, et permettant l'inhibition de la croissance tumorale. Durant mon travail de thèse, j'ai utilisé des nanocristaux de diamant issus soit de détonation (DND), soit de synthèse haute pression-haute température (NDHPHT) pour vectoriser les siRNA, accrochés par interaction électrostatique. Pour ce faire, les NDs ont été rendus cationiques par différentes méthodes: (i) hydrogénation assistée par plasma, (ii) par recuit thermique, ou (iii) par traitement chimique pour les DNDs, ou (iv) greffage covalent d'un polymère cationique sur des NDHPHT (COP-NDHPHT).Mes travaux ont comporté deux axes: (i) étude in vitro des complexes ND:siRNA (caractérisations physico-chimiques des NDs et étude de l'efficacité d'inhibition de l'oncogène par les complexes); (ii) distribution tissulaire de COP-NDHPHT, injectés dans des souris, grâce à des NDHPHT fluorescents, contenant des défauts azote-lacune. Pour les détecter individuellement dans des coupes d'organes de souris portant une tumeur xénogreffée sous-cutanée, nous avons développé un système d'imagerie en épifluorescence à grande ouverture numérique, et résolu en temps afin de rejeter l'autofluorescence tissulaire (de durée de vie plus courte que celle des NDs). Nous avons quantifié le nombre, l'état d'agrégation et la localisation cellulaire de ces vecteurs (grâce à un marquage histopathologique imagé simultanément) 24h après injection. Les NDs ont été clairement détectés dans les différents organes, dont la tumeur, ouvrant la voie à un contrôle de la progression tumorale grâce au siRNA. / Ewing Sarcoma is a rare pediatric cancer, caused in the majority of the cases by the expression of the fusion oncogene EWS-Fli1. Current treatments have not much evolved over the past decades. We are investigating a new therapy based on siRNA specifically targeting the oncogene and inhibiting the tumor growth. During my PhD thesis, I have tested different types of synthetic nanodiamonds (ND) used to vectorize siRNA electrostatically bound at their surface: ND produced by detonation (DND) or by High Pressure-High Temperature synthesis (NDHPTH). Their surfaces have been cationized by various processes: (i) plasma or (ii) thermal hydrogenation, (ii) chemical treatment, or (iv) covalent grafting of a copolymer (COP-NDHPHT).My PhD work included two main axis: (i) in vitro study of ND:siRNA complexes (NDs physico-chemical characterization and oncogene inhibition efficacy by the complexes); (ii) tissue distribution of COP-NDHPHT, injected into mice, using fluorescent NDHPHT containing nitrogen-vacancy defects. To detect them individually in sections of mouse organs carrying a subcutaneous xenograft tumor, we developed an epifluorescence imaging system with large numerical aperture and resolved in time to reject tissue autofluorescence (of a shorter lifetime than NDs). We quantified the number, the aggregation state and the cell localization (thanks to simultaneous histopathological imaging) of these vectors 24 hours after injection. NDs have been clearly detected in different organs, including the tumor, paving the way for tumor progression control with siRNA.

Ewing-like sarcomas (ELS) are a heterogenous group of neoplasms that typically occur in the bone and soft tissue of pediatric and young adult patients. ELS share various degrees of morphological, immunohistochemical, molecular, and clinical similarity with Ewing sarcomas. However, these tumors lack the pathognomonic molecular hallmark of Ewing sarcoma, which is defined as translocation between a gene of the RNA-binding TET family (EWSR1 or FUS) with a gene of the ETS-transcription family (FLI1, ERG, ETV1, ETV4, or FEV). Accurate classification and distinction from classical Ewing sarcomas is important for patient management. A subset of ELS harboring the BCOR-CCNB3 fusion has been described recently – the majority of which that have been reported to date are bone-based tumors, though there have been cases of discrete soft tissue-based tumors. We herein present a case of ELS harboring the BCOR-CCNB3 translocation occurring in a pediatric patient presenting with a large abdominal mass discovered on chest CT after failed outpatient treatment for pneumonia with effusion. This patient was a 14-year-old Caucasian boy with a past medical history significant for obesity and three episodes of pneumonia since 6-years-old. Imaging showed a large heterogeneous mass at the posterior left upper quadrant of the abdomen protruding through the posterior aspect of the left hemidiaphragm causing atelectasis. The mass abuts the inferior leftward aspect of the descending thoracic aorta and also protrudes between the 11th and 12th posterior lateral left rib. Pathology revealed this mass to be an Ewing-like sarcoma with a BCOR-CCNB3 fusion. Patient was treated with chemotherapy and radiation. This case demonstrates the importance of determining an accurate diagnosis to provide specific management.

No description available.

No description available.

No description available.

OBJETIVO: Analisar a frequência da submissão do protocolo de pesquisa aos Comitês de Ética em Pesquisa e da aplicação do Termo de Consentimento Livre e Esclarecido do projeto intitulado “Protocolo Brasileiro para o Tratamento de Pacientes com Tumores da Família de Sarcoma de Ewing”. MÉTODOS: Trata-se de estudo transversal retrospectivo. Através das fichas clínicas dos pacientes foi realizada uma análise do trâmite regulatório, bem como, do processo de obtenção do Termo de Consentimento Livre e Esclarecido de 180 pacientes de 16 instituições. RESULTADOS: Dez dos dezesseis centros submeteram o Protocolo ao Comitê de Ética em Pesquisa local. Em relação ao Termo de Consentimento Livre e Esclarecido, 161 dos 180 pacientes e/ou seus representantes legais consentiram e assinaram o Termo aplicado pelo pesquisador. Destes, 123 assinaram o Termo de Consentimento específico do protocolo e 38 assinaram o Termo de Consentimento institucional. Em relação à data da assinatura do consentimento, 141 dos 161 pacientes assinaram o Termo de Consentimento após receberem as informações referentes ao estudo clínico e antes de iniciar o tratamento. CONCLUSÃO: A maioria das instituições participantes apresenta uma estrutura adaptada ao assistencialismo e não estavam familiarizadas com aspectos éticos, legais e regulatórios que envolvem um projeto desta natureza. / OBJECTIVE: To analyze the frequency of submission of the research protocol to the Institutional Research Board and application of Informed Consent Form related to a clinical trial entitled “Treatment of Patients with Ewing Sarcoma Family of Tumors: A study of the Brazilian Cooperative Group”. METHODS: Retrospective cross-sectional study. Through patient records were performed an analysis of the regulatory proceeding and the signing of the Informed Consent Form by 180 patients from 16 institutions. RESULTS: Ten of the sixteen centers submitted the Protocol to the local Institutional Review Board. Regarding the Informed Consent Form, 161 of 180 patients and/or their legal representatives consented and signed the Form applied by the researcher. Of these, 123 signed the consent form specific to the protocol and 38 signed an institutional form. Regarding the date the consent form was signed, 141 of 161 patients signed it after receiving information about the trial and before starting treatment. CONCLUSION: Most of the participating institutions had a structure adapted to welfare and were not familiar with the ethical, legal and regulatory systems involved in a project like this.

OBJETIVO: Analisar a frequência da submissão do protocolo de pesquisa aos Comitês de Ética em Pesquisa e da aplicação do Termo de Consentimento Livre e Esclarecido do projeto intitulado “Protocolo Brasileiro para o Tratamento de Pacientes com Tumores da Família de Sarcoma de Ewing”. MÉTODOS: Trata-se de estudo transversal retrospectivo. Através das fichas clínicas dos pacientes foi realizada uma análise do trâmite regulatório, bem como, do processo de obtenção do Termo de Consentimento Livre e Esclarecido de 180 pacientes de 16 instituições. RESULTADOS: Dez dos dezesseis centros submeteram o Protocolo ao Comitê de Ética em Pesquisa local. Em relação ao Termo de Consentimento Livre e Esclarecido, 161 dos 180 pacientes e/ou seus representantes legais consentiram e assinaram o Termo aplicado pelo pesquisador. Destes, 123 assinaram o Termo de Consentimento específico do protocolo e 38 assinaram o Termo de Consentimento institucional. Em relação à data da assinatura do consentimento, 141 dos 161 pacientes assinaram o Termo de Consentimento após receberem as informações referentes ao estudo clínico e antes de iniciar o tratamento. CONCLUSÃO: A maioria das instituições participantes apresenta uma estrutura adaptada ao assistencialismo e não estavam familiarizadas com aspectos éticos, legais e regulatórios que envolvem um projeto desta natureza. / OBJECTIVE: To analyze the frequency of submission of the research protocol to the Institutional Research Board and application of Informed Consent Form related to a clinical trial entitled “Treatment of Patients with Ewing Sarcoma Family of Tumors: A study of the Brazilian Cooperative Group”. METHODS: Retrospective cross-sectional study. Through patient records were performed an analysis of the regulatory proceeding and the signing of the Informed Consent Form by 180 patients from 16 institutions. RESULTS: Ten of the sixteen centers submitted the Protocol to the local Institutional Review Board. Regarding the Informed Consent Form, 161 of 180 patients and/or their legal representatives consented and signed the Form applied by the researcher. Of these, 123 signed the consent form specific to the protocol and 38 signed an institutional form. Regarding the date the consent form was signed, 141 of 161 patients signed it after receiving information about the trial and before starting treatment. CONCLUSION: Most of the participating institutions had a structure adapted to welfare and were not familiar with the ethical, legal and regulatory systems involved in a project like this.

OBJETIVO: Analisar a frequência da submissão do protocolo de pesquisa aos Comitês de Ética em Pesquisa e da aplicação do Termo de Consentimento Livre e Esclarecido do projeto intitulado “Protocolo Brasileiro para o Tratamento de Pacientes com Tumores da Família de Sarcoma de Ewing”. MÉTODOS: Trata-se de estudo transversal retrospectivo. Através das fichas clínicas dos pacientes foi realizada uma análise do trâmite regulatório, bem como, do processo de obtenção do Termo de Consentimento Livre e Esclarecido de 180 pacientes de 16 instituições. RESULTADOS: Dez dos dezesseis centros submeteram o Protocolo ao Comitê de Ética em Pesquisa local. Em relação ao Termo de Consentimento Livre e Esclarecido, 161 dos 180 pacientes e/ou seus representantes legais consentiram e assinaram o Termo aplicado pelo pesquisador. Destes, 123 assinaram o Termo de Consentimento específico do protocolo e 38 assinaram o Termo de Consentimento institucional. Em relação à data da assinatura do consentimento, 141 dos 161 pacientes assinaram o Termo de Consentimento após receberem as informações referentes ao estudo clínico e antes de iniciar o tratamento. CONCLUSÃO: A maioria das instituições participantes apresenta uma estrutura adaptada ao assistencialismo e não estavam familiarizadas com aspectos éticos, legais e regulatórios que envolvem um projeto desta natureza. / OBJECTIVE: To analyze the frequency of submission of the research protocol to the Institutional Research Board and application of Informed Consent Form related to a clinical trial entitled “Treatment of Patients with Ewing Sarcoma Family of Tumors: A study of the Brazilian Cooperative Group”. METHODS: Retrospective cross-sectional study. Through patient records were performed an analysis of the regulatory proceeding and the signing of the Informed Consent Form by 180 patients from 16 institutions. RESULTS: Ten of the sixteen centers submitted the Protocol to the local Institutional Review Board. Regarding the Informed Consent Form, 161 of 180 patients and/or their legal representatives consented and signed the Form applied by the researcher. Of these, 123 signed the consent form specific to the protocol and 38 signed an institutional form. Regarding the date the consent form was signed, 141 of 161 patients signed it after receiving information about the trial and before starting treatment. CONCLUSION: Most of the participating institutions had a structure adapted to welfare and were not familiar with the ethical, legal and regulatory systems involved in a project like this.

Les sections efficaces neutroniques des noyaux de courte durée de vie sont des données cruciales pour la physique fondamentale et appliquée dans des domaines tels que la physique des réacteurs ou l’astrophysique nucléaire. En général, l’extrême radioactivité de ces noyaux ne nous permet pas de procéder à des mesures induites par neutrons. Cependant, il existe une méthode de substitution (« surrogate » dans la littérature) qui permet de déterminer ces sections efficaces neutroniques par l’intermédiaire de réactions de transfert ou de réactions de diffusion inélastique. Son intérêt principal est de pouvoir utiliser des cibles moins radioactives et ainsi d’accéder à des sections efficaces neutroniques qui ne pourraient pas être mesurées directement. La méthode est basée sur l’hypothèse de formation d’un noyau composé et sur le fait que la désexcitation ne dépend essentiellement que de l’énergie d’excitation et du spin et parité de l'état composé peuplé. Toutefois, les distributions de moments angulaires et parités peuplés dans des réactions de transfert et celles induites par neutrons sont susceptibles d’être différentes. Ce travail fait l’état de l’art sur la méthode substitution et sa validité. En général, la méthode de substitution fonctionne très bien pour extraire des sections efficaces de fission. Par contre, la méthode de substitution dédiée à la capture radiative est mise à mal par la comparaison aux réactions induites par neutrons. Nous avons réalisé une expérience afin de déterminer les probabilités de désexcitation gamma du 176Lu et du 173Yb à partir des réactions de substitution 174Yb(3He,p)176Lu* et 174Yb(3He,alpha)173Yb*, respectivement, et nous les avons comparées avec les probabilités de capture radiative correspondantes aux réactions 175Lu(n,gamma) et 172Yb(n,gamma) qui sont bien connues. Cette expérience a permis de comprendre pourquoi, dans le cas de la désexcitation gamma, la méthode de substitution donne des écarts importants par rapport à la réaction neutronique correspondante. Ce travail dans la région de terres rares a permis d'évaluer dans quelle mesure la méthode de substitution peut s’appliquer pour extraire des probabilités de capture dans la région des actinides. Des expériences précédentes sur la fission ont aussi pu être réinterprétées. Ce travail apporte donc un éclairage nouveau sur la méthode de substitution. / Neutron-induced cross sections of short-lived nuclei are needed for fundamental and applied physics as nuclear energy or astrophysics. However, very often the high radioactivity of the samples makes the direct measurement of these cross sections extremely difficult. The surrogate reaction method is an indirect way of determining neutron-induced cross sections through transfer or inelastic scattering reactions. This method presents the advantage that in some cases the target material is stable or less radioactive than the material required for a neutron-induced measurement. The method is based on the hypothesis that the excited nucleus is a compound nucleus whose decay depends essentially on its excitation energy and on the spin and parity state of the populated compound state. Nevertheless, the spin and parity population differences between the compound-nuclei produced in the neutron and transfer-induced reactions may be different. This work reviews the surrogate method and its validity. Neutron-induced fission cross sections obtained with the surrogate method are in general good agreement. However, it is not yet clear to what extent the surrogate method can be applied to infer radiative capture cross sections. We performed an experiment to determine the gamma-decay probabilities for 176Lu and 173Yb by using the surrogate reactions 174Yb(3He,p)176Lu* and 174Yb(3He,alpha)173Yb*, respectively, and compare them with the well-known corresponding probabilities obtained in the 175Lu(n,gamma) and 172Yb(n,gamma) reactions. This experiment provides answers to understand why, in the case of gamma-decay, the surrogate method gives significant deviations compared to the corresponding neutron-induced reaction. In this work, we have also assessed whether the surrogate method can be applied to extract capture probabilities in the actinide region. Previous experiments on fission have also been reinterpreted. Thus, this work provides new insights into the surrogate method.

Made available in DSpace on 2015-04-14T14:51:17Z (GMT). No. of bitstreams: 1 438120.pdf: 2337312 bytes, checksum: 3bcbd6b2d333489c6e0cefb866d0b73c (MD5) Previous issue date: 2012-03-30 / Ewing s sarcoma was first described by James Ewing in 1921 and it is the second most common bone tumor in children and young adults. Both chromosomal breakage and translocation occur in this sarcoma. The EWS gene is localized in chromosome 22 and is involved in this translocation. However, little is known about this gene breaking region and what sequences could be involved in higher chromosomal break susceptibility. In this study we aimed to investigate three SNPs in the EWS gene breaking region in a healthy subjects population and in Ewing s sarcoma patients. Genotyping was performed by TaqMan? assay for allelic discrimination using Real-Time PCR System. We conducted analysis of allelic and genotypic frequencies, as well as association and transmission disequilibrium tests. According to our results, the control group showed similar and different genotypes distribution of all SNPs when compared to other populations studied by different projects, which shows how important it is to know the frequencies of our population. To test the hypothesis that some SNP, SNParrangement or haplotype could influence in the susceptibility to develop Ewing s sarcoma, we compared affected with non-affected individuals using association studies. The results showed one significant difference: a higher presence of homozygote T-rs4820804 in Ewing s Sarcoma patients. Transmission Disequilibrium Test (TDT) was performed to compare data from Ewing s Sarcoma patients and from their families but no statistically significant result was found. In conclusion, we find that the TT-rs4820804 EWS genotype can be associate with Ewing s sarcoma and that the rs4820804 SNP can be a candidate to understand the EWS breakage susceptibility. / O sarcoma de Ewing foi primeiramente descrito por James Ewing em 1921 e ? o segundo tumor ?sseo mais frequente em crian?as, adolescente e adultos jovens. Neste sarcoma, ? comum ocorrer a quebra e a transloca??o cromoss?mica. Dentre os genes envolvidos nesta transloca??o est? o gene EWS, localizado no cromossomo 22. Entretanto, pouco se sabe a respeito da regi?o de quebra deste gene e quais sequ?ncias poderiam levar a uma maior susceptibilidade a quebra cromoss?mica. Sendo assim, o objetivo deste trabalho foi investigar tr?s polimorfismos de base ?nica (SNPs) presentes na regi?o de quebra do gene EWS, em uma popula??o de indiv?duos saud?veis e em pacientes afetados pelo Sarcoma de Ewing. A genotipagem para os SNPs selecionados foi realizada usando TaqMan SNP Genotyping Assay pelo sistema de PCR em tempo real. N?s realizamos an?lises de frequ?ncias al?licas e genot?picas, assim como um estudo de associa??o e de desequil?brio de transmiss?o. A compara??o das frequ?ncias al?licas e genot?picas entre as popula??es deste estudo e entre popula??es de projetos j? publicados mostrou particularidades entre as popula??es, revelando a import?ncia de se conhecer tais frequ?ncias na popula??o de estudo. Para testar a hip?tese de que algum SNP, hapl?tipo ou combina??o espec?fica de SNPs poderia influenciar na susceptibilidade ao Sarcoma de Ewing, comparamos afetados com n?o-afetados realizando estudos de associa??o cujos resultados mostraram uma ?nica diferen?a significativa: a maior incid?ncia no gen?tipo TT-rs4820804 entre os afetados pelo Sarcoma de Ewing. O Teste de Desequil?brio de Transmiss?o (TDT) comparou os dados dos pacientes afetados e os dados de seus familiares, mas nenhum resultado significativo foi encontrado. Em conclus?o, o gen?tipo TT-rs4820804 pode estar associado ao Sarcoma de Ewing e o SNP rs4820804 pode ser candidato para aux?lio do entendimento da susceptibilidade de quebra do gene EWS.