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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.
51

Klinische und molekularzytogenetische Charakterisierung von Tumoren der Pinealisregion / Clinical and cytogenetic characterization of tumors of the pineal region

Böhrnsen, Björn Florian 27 November 2013 (has links)
Raumforderungen der PR haben ihren Ursprung zum einen in den pinealen Geweben und zum anderen in den heterogenen Strukturen des ZNS. Aufgrund ihrer anatomischen Lage im Bereich der zirkumventrikulären GP und des Hirnstammes bedeuten sie im fortgeschrittenen Stadium für die Patienten eine massiv eingeschränkte Lebensqualität bei zunehmend schlechter Prognose. Die Heterogenität dieser Tumoren stellt die Medizin jedoch vor eine große diagnostische und therapeutische Herausforderung. Entscheidend für eine optimale Therapie ist eine eindeutige Charakterisierung dieser Raumforderungen. In dieser Arbeit ist es erstmals gelungen, neben pineal-parenchymalen Raumforderungen und Keimzelltumoren der PR, pilozytische Astrozytome, einen solid-fibrösen und einen neuroendokrinen Tumor der PR molekularzytogenetisch zu charakterisieren. Die Karzinogenese der Raumforderungen der PR ist nicht abschließend geklärt. Von Tumoren, die einer histologischen Zellpopulation entsprächen, wären in Regelhaftigkeit identische genetische Veränderungen zu erwarten. Die Analysen in dieser Arbeit zeigen zum einen übereinstimmende molekularzytogenetische Veränderungen der Chromosomen 7, 9, 12 und 17 mit zuvor beschriebenen Tumoren der PR. Zudem konnte erstmals eine Vielzahl neuer chromosomaler Veränderungen beschrieben werden. Diese molekulargenetische Heterogenität stellt die aktuelle Zuordnung der Raumforderungen der PR nicht in Frage, unterstreicht jedoch, dass eine weitere histologische Charakterisierung notwendig ist, um Subgruppen zu identifizieren. Sie zeigt, dass klassische Konzepte der Tumorigenese die molekularzytogenetische Heterogenität dieser Tumoren nur unzureichend beschreiben und durch progressivere Tumormodelle ergänzt werden müssen (Berger et al. 2011). Tumoren und Raumforderungen der PR entsprechen im Kindesalter 3-8% und im Erwachsenenalter weniger als 1% aller intrazerebralen Raumforderungen (Edwards et al. 1988; Regis et al. 1996; Rickert et al. 2001), so dass Untersuchungen größerer Patienten-kollektive über einen längeren Zeitraum schwierig sind. Die molekular¬zytogenetische Zuordnung der in dieser Arbeit untersuchten Raumforderungen unterstützt und ergänzt die Charakterisierung der Tumorentitäten. Auch wenn nur eine geringe Tumoranzahl über einen längeren Zeitraum untersucht werden konnte, so ist anzunehmen, dass es möglich sein wird, einzelnen histologischen Entitäten ein zytogenetisches Muster zuzuordnen, wenn größere Tumorkollektive der PR untersucht werden. So kann die Diagnostik erweitert und eine prognostische Bedeutung zum Wohle der Patienten erlangt werden.
52

Les dysplasies tubo-ovariennes : contribution à une meilleure compréhension de la carcinogenèse ovarienne / Ovarian and tubal dysplasia : an early event in the pathogenesis of epithelial ovarian cancer

Chêne, Gautier 14 June 2011 (has links)
Introduction : l’analyse histopathologique des pièces d’annexectomie prophylactique(pBSO) pour risque génétique (mutations BRCA) a pu révéler des anomalies cytologiques etarchitecturales interprétées comme potentiellement pré-cancéreuses et dénommées « dysplasieovarienne et tubaire ». Nous proposons d’étudier les aspects morphologiques,immunohistochimiques et moléculaires des dysplasies tubo-ovariennes.Matériels & Méthodes : l’analyse morphologique a été réalisée dans un premier grouped’annexectomies après stimulation de l’ovulation (protocole de Fécondation in vitro).L’évaluation morphologique et immunohistochimique (expression de Ki67, p53, Bcl2, PAX2et ALDH1) a par la suite concerné 111pBSO, 42 annexectomies exposées au Tamoxifène et116 témoins non cancéreux et spontanément fertiles (nBSO). Les analyses ont été réaliséespar deux pathologistes en aveugle. Les cellules épithéliales d’intérêt ovariennes et tubairesprovenant du groupe pBSO ont été microdisséquées par laser ; l’ADN extrait a été étudié parhybridation génomique comparative (CGH array). La longueur des télomères a été évaluéepar PCR quantitative en temps réel.Résultats : les scores moyens de dysplasie ovarienne et tubaire étaient significativement plusélevés dans les groupes stimulation de l’ovulation et génétique par rapport aux témoins. Seulle score de dysplasie tubaire était supérieur aux témoins pour le groupe Tamoxifène. Onretrouvait une surexpression de ALDH1 dans les groupes pBSO et tBSO alors que Ki67, p53,bcl2 et PAX2 étaient faiblement exprimés dans les groupes pBSO et tBSO. D’ailleurs,l’expression d’ALDH1 était faible dans l’épithélium non dysplasique, forte dans la dysplasieet constamment faible dans les carcinomes occultes. De subtiles altérations génomiques et desraccourcissements télomériques ont été mis en évidence au niveau des dysplasies génétiques.Conclusions : les scores élevés de dysplasie, la forte expression d’ALDH1 et les altérationsmoléculaires provenant du groupe à risque génétique pourraient supporter le conceptd’instabilité génétique. La dysplasie tubo-ovarienne pourrait être une étape importante etprécoce de la carcinogenèse ovarienne. Nos résultats suggèrent également qu’un certainnombre de cancers de l’ovaire pourrait avoir pour origine la trompe de Fallope. Le marqueurde cellules souches ALDH1 pourrait constituer une cible dans la prévention et le diagnosticprécoce des cancers de l’ovaire. / Background: Histopathological examination of material from prophylactic salpingooophorectomies(pBSO) performed in patients at genetic risk has revealed frequentabnormalities interpreted as possible pre-cancerous “ovarian and tubal dysplasia” lesions. Wesought to study the morphologic, immunohistochemical and molecular features in ovarian andtubal dysplasiaMaterials and methods : Morphologic analysis was evaluated in 37 oophorectomies afterovulation induction (iBSO). Morphologic features and immunohistochemical expressionpatterns of Ki-67, p53, Bcl2, PAX2 and ALDH1 (an enzyme significantly associated withearly-stage ovarian cancer) were evaluated in 111 pBSO, 42 salpingo-oophorectomiesexposed with Tamosifen (tBSO) and 116 normal salpingo-oophorectomies (nBSO).Representative slides from formalin-fixed, paraffin-embedded tissue blocks were read blindlyby two gynaecological pathologists. Tubal and ovarian epitheliums from normal anddysplastic tissues (from pBSO) were laser microdissected and studied by comparativegenomic hybridization (array CGH). Telomere length was performed using quantitative realtimePCR.Results: Mean ovarian and tubal dysplasia score were significantly higher in the ovulationinduction group and in the genetic risk group than in controls. Only tubal dysplasia score wassignificantly higher in the Tamoxifen group. Increased ALDH1 expression was observed inpBSO and tBSO compared with nBSO whereas expression patterns of Ki67, p53, bcl2 andPAX2 were low at moderate in pBSO and tBSO group. Interestingly, ALDH1 expression waslow in non dysplastic epithelium, high in dysplasia and constantly low in the carcinoma foundincidentally on pBSO. Subtle genomic alterations were found in the dysplastic ovarian andtubal epitheliums. Shortened telomeres were found in dysplastic tissues from pBSO.Conclusion: The increased dysplasia scores, the strong ALDH1 expression and the geneticalterations in ovaries and tubes from BRCA 1/2 carriers could support the genetic instabilityof dysplasia and might be consistent with progression towards neoplastic transformation andcould justify the use of the term “dysplasia”. Ovarian and tubal dysplasia may be a premalignant,non-invasive histopathological abnormalitie that could be an important step in11early ovarian neoplasia. Our results suggest that a greater percentage of ovarian cancers thanoriginally thought may actually have a fallopian origin with metastasis to the ovary. The stemcell marker ALDH1 activation in pBSO could be considered as a target for early diagnosisand prevention of ovarian cancers.
53

Avaliação Genético-Molecular do Carcinoma das Células Escamosas da Laringe / Assessing the Molecular and Genetic Aspects of Squamous Cell Carcinoma of the Larynx

SILVA, Cláudio Carlos da 21 October 2009 (has links)
Made available in DSpace on 2014-07-29T15:10:31Z (GMT). No. of bitstreams: 1 claudio carlos.pdf: 4222908 bytes, checksum: 9eff1b9f349ce5868c10ca1d5b440898 (MD5) Previous issue date: 2009-10-21 / The larynx is a structure of the upper aerodigestive tract responsible for the production of sounds as well as protecting the lower airways and helping during the normal act of swallowing. Any pathology which affects the larynx can impose several challenges that disrupt its normal physiological function, and consequently and directly resulting in reduction of the patient s quality of life. Among the different diseases that affect the larynx, cancer is one of the most serious. The squamous cell carcinoma (SCC) of the larynx is a multifactorial disease, influenced by environmental factors and individual behavioral, habits, and susceptibility. The current study describes the molecular and genetic assessment of 20 patients with the squamous cell carcinoma of the larynx. In summary, the study strategy included the analyses of the genetic polymorphism of codon 72 of the TP53, the detection and genotyping of HPV genome, assessing genomic instability (MIS and LOH) and random chromosomal imbalances using PCR and CGH approaches. Regarding to the polymorphism of the TP53 gene, arginine homozygous genotypes (p53AA) and arginine-proline heterozygous genotypes (p53PA) were found in 65% (13/20) and 35% (7 / 20) of cases, respectively. HPV genome was found in association with tumor cells in 20% of SCC cases. HPV 16, 11, and 45 were the genotypes identified. Moreover, co-infection of HPV 11 and 45 was also observed. Both samples found positive for HPV genome were associated with p53AA at the TP53 gene. Our results corroborated the data published in the literature that described an increased susceptibility to the virus-induced carcinogenesis of the larynx in arginine homozygous genotypes. Here in we report genomic instability for a panel of 8 microsatellite markers distributed in 5 chromosomes. One locus (D8S135) was found in homozygous for all cases. On the other hand, RH-92600 was not included in the analysis mainly because it was also found homozygous for most cases. We found 76.2% (244/320) of informative loci. Thus the mean frequency of MIS was 9.0% (22/244) and LOH was 6.1% (15/244). The frequency of MIS was found higher than the LOH, suggesting that the tumorigenesis of SCC of the larynx follows a mechanism of mutator phenotype. Using CGH, chromosomal gains were observed in 1q21qter. On the other hand, chromosomal losses occurred in chromosome 3p21p28, 11q23, 16p16, 16q12, 17p13pter and 22q13. The techniques of comparative genomic hybridization have improved the understanding of genetic alterations in squamous cell carcinoma of the larynx, especially for characterizing the relationship between early precursors of laryngeal carcinomas, as well as to identify genomic regions that may contain oncogenes and tumor suppressor genes involved in the tumorigenesis of this anatomical site. / A laringe é uma estrutura tubular do trato aero digestivo com a principal função de formação de sons, além de estar relacionada com a proteção das vias aéreas inferiores e deglutição dos alimentos. Qualquer patologia que acomete este órgão pode ocasionar diversos problemas em sua função fisiológica normal, com influência plena e direta no decréscimo da qualidade de vida do indivíduo. Das diversas doenças que afetam a laringe, o câncer apresenta-se como uma das mais graves. O carcinoma de células escamosas da laringe apresenta-se como uma doença multifatorial e epigenética sendo influenciada por fatores ambientais, comportamentais e inerentes ao indivíduo. Este estudo avaliou 20 indivíduos portadores do carcinoma das células escamosas da laringe. Dentre dos parâmetros avaliados, destacam-se o polimorfismo do códon 72 do gene do gene TP53, a detecção e genotipagem do genoma de HPV, a instabilidade genômica (LOH e MIS) e alterações cromossômicas não balanceadas. Em relação ao polimorfismo de TP53, os resultados foram 65% (13/20) de homozigotos (TP53AA) e 35% (7/20) de heterozigotos (TP53PA). Em 20% dos pacientes foi observada a presença de genoma HPV associada às células tumorais, tendo sido genotipados os subtipos virais HPV 16 em uma amostra e HPV 11 e 45 na outra amostra, caracterizando uma co-infecção. Os dois casos positivos para HPV apresentaram genótipo homozigoto (TP53AA) para o gene TP53. Os resultados deste estudo corroboram os dados publicados na literatura pertinente, que correlacionam a susceptibilidade aumentada para CEC da laringe em indivíduos homozigotos para TP53Arg e a maior susceptibilidade destes à carcinogênese vírus-induzida. A instabilidade genômica foi avaliada utilizando um painel de 8 marcadores de microssatélites distribuídos em 5 cromossomos diferentes. Os loci D8S135 e RH-92600 foram considerados não informativos, pois se apresentaram homozigotos na maioria dos casos, enquanto que 76,2% (244/320) loci foram informativos. Contudo, a freqüência de MIS foi de 9% (22/244) e a freqüência de LOH de 6,1% (15/244). A freqüência observada de MIS foi maior do que a freqüência de LOH, sugerindo que o carcinoma das células escamosas da laringe segue o mecanismo fenótipo mutante . A hibridação genômica comparativa mostrou que a principal região cromossômica que apresentou ganhos foi em 1q21qter, enquanto que as perdas cromossômicas ocorreram em 3p21p28, 11q23, 16p16, 16q12, 17p13pter e 22q13. As técnicas de hibridação genômica comparativa têm contribuído para melhorar a compreensão das alterações genéticas no carcinoma das células escamosas da laringe, sobretudo para a caracterização da relação entre estágios precursores de câncer laríngeo, assim como, para a identificação de regiões genômicas que podem conter oncogenes e genes supressores tumorais.
54

Correlação cariótipo-genótipo-fenótipo de rearranjo cromossômico estrutural familiar envolvendo as regiões 4p e 12q / Karyotype-genotype-phenotype correlation of a familial structural chromosomal rearrangement involving regions 4p and 12q

Tatiana Mozer Joaquim 21 March 2016 (has links)
Rearranjos cromossômicos estruturais estão potencialmente associados ao desenvolvimento de doenças genéticas devido à disrupção, inativação ou alteração da dosagem gênica. O objetivo deste projeto foi realizar a caracterização genômica de duas pacientes e seus familiares portadores de rearranjo cromossômico estrutural envolvendo o braço curto do cromossomo 4 e o braço longo do cromossomo 12, associando técnicas de citogenética clássica (bandamento GTG), citogenética molecular (FISH) e citogenômica (array-CGH), para definição diagnóstica e maior conhecimento sobre os fatores envolvidos na correlação cariótipo-genótipo-fenótipo. Foram avaliados seis indivíduos, duas pacientes, primas em primeiro grau que apresentavam alterações fenotípicas, assim como seus familiares, portadores de translocação aparentemente equilibrada e fenótipo normal. Apesar das duas pacientes apresentarem alteração cromossômica comum, derivativo do cromossomo 4 [der(4)], foram observados achados fenotípicos distintos. A investigação permitiu a definição do diagnóstico de deleção 4p16 e trissomia 12qter para as duas pacientes com fenótipo alterado e cariótipo 46,XX,der(4)t(4;12)(p16;q24.3), a definição precisa dos pontos de quebra em 4p16.3 e 12q24.31->q24.33, assim como a determinação da origem parental do rearranjo e a definição do diagnóstico citogenético final de quatro portadores de translocação aparentemente equilibrada e cariótipo t(4;12)(4pter->4p16.3::2q24.31->12qter;12qter->12q24.31::4p16.3->4pter),direcionando o aconselhamento genético para a família. Nas duas pacientes, a técnica de array-CGH (Plataforma 2x400K, Agilent®) detectou uma diferença sutil de tamanho entre as perdas e ganhos referentes aos cromossomos envolvidos no rearranjo, sendo diagnosticado em P1 uma perda de 2.707.221 pb na citobanda 4p16.3, além de um ganho de 12.405.205 pb em 12q24.31->q24.33. A paciente 2 apresentou uma perda de 2.710.969 pb em 4p16.3 e um ganho de 12.393.885 pb em 12q24.31->q24.33. Ambas as regiões de desequilíbrio genômico incluem genes que podem ser relevantes para manifestação fenotípica observada nas pacientes, entre eles: WHSC1, NELFA, LETM1, FGFRL1 e SPON2. Os resultados da investigação citogenômica indicaram, ainda, a presença de translocação equilibrada nos quatro indivíduos portadores, não sendo detectadas perdas e/ou ganhos genômicos nas regiões dos pontos de quebra cromossômica. Os resultados obtidos na investigação do padrão de metilação dos genes FGFRL1 e SPON2 não permitiram afirmar que uma provável repressão da expressão gênica devido ao imprinting materno e paterno esteja associada às características fenotípicas distintas observadas nas duas pacientes. Embora tenha sido possível a indicação de genes correlacionados ao fenótipo das pacientes, a correlação entre a alteração genética e o fenótipo das mesmas pode depender da ação sinérgica dos mais de 190 genes envolvidos neste rearranjo cromossômico estrutural familiar. / Structural chromosomal rearrangements are potentially associated with the development of genetic disorders due to disruption, inactivation or gene dosage alterations. The objective of this project was to perform the genomic characterization of a familial structural chromosomal rearrangement involving the short arm of chromosome 4 and the long arm of chromosome 12 in two patients and carriers. The experimental approach involved using a combination of classical cytogenetic techniques (GTG banding), molecular cytogenetics (FISH) and cytogenomics (array-CGH), to provide a diagnostic definition and a better understanding of how changes in the karyotype and genotype may be associated with the phenotype. Six individuals were evaluated, two patients with phenotypic abnormalities, as well as the carriers of an apparently balanced 4p;12q translocation with normal phenotypes. Although the two patients showed a common chromosomal abnormality, the derivative chromosome 4 [der (4)], they presented distinct phenotypic findings. The investigation provided a definition of the diagnosis of 4p16 deletion and trisomy 12qter for the two patients with abnormal phenotypes and a karyotype 46,XX,der(4)t(4;12)(p16;q24.3). In addition a precise definition of the breakpoints at 4p16.3 and 12q24.31->q24.33, and the parental origin of the rearrangement was determined. A precise definition of the cytogenetic diagnosis of four carriers with an apparently balanced translocation and karyotype t(4;12)(4pter->4p16.3::2q24.31->12qter; 12qter 12q24.31->4pter::4p16.3), facilitated the genetic counseling for the family. In both patients, the array-CGH technique (2x400K Platform, Agilent®) detected a subtle difference in size between losses and gains in the chromosomal regions involved in the rearrangement. Patient 1 presented a loss of 2,707,221 bp in the cytoband 4p16.3, and a gain of 12,405,205 bp in 12q24.31->q24.33. Patient 2 had a loss of 2,710,969 bp in 4p16.3 and a gain of 12,393,885 bp in 12q24.31 -> q24.33. Both regions of genomic imbalance included genes that may be relevant to phenotypic findings observed in our patients, including: WHSC1, NELFA, LETM1, FGFRL1 and SPON2. Genomic findings also confirmed the presence of a balanced translocation in four carriers, with no genomic losses and/or gains in the regions of chromosome breakpoints. The results of the investigation of the methylation pattern of FGFRL1 and SPON2 genes could not demonstrate that repression of gene expression due to maternal and paternal imprinting was associated with the distinct phenotypes observed in the two patients. Although it has been possible to indicate genes related to the phenotype of the patients, the correlation between the genetic alteration and phenotype may depend on the synergistic action of multiple genes from more than the 190 involved in this familial chromosomal rearrangement.
55

Investigação genômica de pacientes inférteis com oligozoospermia / Genomic investigation of infertile patients with oligozoospermia

Juliana Dourado Grzesiuk 13 December 2016 (has links)
A infertilidade afeta aproximadamente 15% dos casais, sendo atualmente reconhecido o envolvimento de fatores masculinos em metade dos casos. Alterações nas análises seminais são detectadas na maioria dos homens inférteis e a mais frequente é a baixa concentração de espermatozoides no ejaculado, conhecida como oligozoospermia. Vários estudos mostram uma forte relação entre fatores genéticos e a infertilidade, incluindo alterações cromossômicas e microdeleções do cromossomo Y, porém as causas da oligozoospermia ainda permanecem obscuras. O desenvolvimento de novas tecnologias de investigação vem possibilitando a detecção de alterações a nível genômico, como mutações e variações no número de cópias (CNVs). O presente trabalho teve por objetivo a caracterização genômica de homens com oligozoospermia sem causa definida, visando estabelecer correlação entre alterações no número de cópias e perdas de heterozigosidade (LOHs) e o fenótipo de infertilidade. Foram selecionados 18 pacientes após rigorosa avaliação clínica e investigação do histórico reprodutivo, sendo excluídos pacientes portadores de alterações cromossômicas e portadores de microdeleções do cromossomo Y. Seis homens comprovadamente férteis foram selecionados para o grupo controle. A investigação genômica de ambos os grupos, amostral e controle, foi realizada pela técnica de hibridação genômica comparativa em microarranjos (aCGH) utilizando a plataforma de resolução 180K (Agilent®,US), analisada pelo software Nexus 8.0. Foram detectadas alterações possivelmente patogênicas no cromossomo Y, no cromossomo X e em autossomos. Um ganho na região de AZFc envolvendo apenas os genes DAZ1 e DAZ4 foi detectado em nove pacientes e em quatro controles, sendo classificado como alteração benigna. Porém, alterações na região de AZFc possivelmente relacionadas ao fenótipo de oligozoospermia foram detectadas em três pacientes e incluíram extensas duplicações e deleções envolvendo, entre outros genes, as quatro cópias do gene DAZ. Após comparação de regiões selecionadas com a literatura e com diferentes bancos de dados genéticos, sugerimos que os genes PLEC, SPATC1, COL1A1, MOV10L1, SYCE3 e ODF3B possam estar associados a alterações na produção espermática. Adicionalmente, entre os doze miRNAs presentes em regiões de LOH possivelmente relacionadas ao fenótipo de infertilidade, dez têm como alvo genes com funções relacionadas à espermatogênese e reprodução humana. Estudos adicionais a nível de expressão e sequenciamento gênico são necessários para confirmar a correlação entre o genótipo e o fenótipo de oligozoospermia. / Infertility affects about 15% of the couples, and it is currently recognized, that male factors are involved in about 50% of cases. Changes in seminal parameters are detected in most infertile men and the most common alteration, known as oligozoospermia, is a low concentration of sperm in the ejaculate. Several studies show a strong relationship between genetic factors and infertility, including chromosomal abnormalities and microdeletions of Y chromosome, however, the causes of oligozoospermia remain unclear. The development of new research technologies has allowed the detection of changes at genomic levels, such as mutations and copy number variations (CNVs). This study aimed to perform a genomic characterization of patients with idiopathic oligozoospermia to determine whether there is a correlation between changes of copy number and losses of heterozygosity (LOHs) in relation to the phenotype of infertility. Eighteen patients were selected for the cases after rigorous clinical examination and investigation of their reproductive history. Patients with chromosomal abnormalities or microdeletions of the Y chromosome were excluded. Six proven fertile men comprised the control group. Genomic investigation of both groups was performed by microarray comparative genomic hybridization (aCGH) using 4X180K platform (Agilent, US) analysed by Nexus 8.0 software. Potential pathogenic changes were detected on Y chromosome, as well as on the X and autosome chromosomes. A gain in AZFc region involving only DAZ1 and DAZ4 genes was detected in nine patients and four controls, and was considered as benign. However, changes in AZFc region, that could be related to the oligozoospermia phenotype were detected in three patients. These changes included extensive duplications and deletions involving the four copies of the DAZ gene together with copy number changes affecting other genes. After comparing the selected regions with the literature and with different databases, we suggest that changes such as LOH affecting PLEC, SPATC1, COL1A1, MOV10L1, SYCE3 and ODF3B genes may influence sperm production. Our analysis indicates that, ten out of the twelve miRNAs present in LOH regions could be involved in the infertility phenotype and could have target genes with functions related to spermatogenesis and human reproduction. Additional studies involving gene sequencing and expression analysis are needed to confirm the the correlation between the genotype and oligozoospermia phenotype.
56

Alterações genômicas e epigenômicas nas manifestações anatomopatológicas e cognitivas da doença de Alzheimer / Genomic and epigenomic alterations in the anatomopathological and cognitive manifestations of Alzheimer\'s disease

Darine Christina Maia Villela 19 September 2014 (has links)
A doença de Alzheimer (DA) é a causa mais comum de demência na população, sendo responsável por cerca de 50 a 60% dos casos. Embora o diagnóstico clínico da doença na maioria das vezes seja acurado, a confirmação da DA só é feita post mortem através principalmente da caracterização dos dois tipos principais de lesões neurais: depósitos extracelulares de placas de β amiloide e emaranhados de proteína tau hiperfosforilada. Até o momento, o envolvimento de apenas quatro genes foi confirmado na etiologia da DA, três deles (APP, PSEN1 e PSEN2) associados à forma familial de herança mendeliana, que corresponde a um tipo raro e grave. No entanto, apesar de inúmeros trabalhos de associação genômica, (Genome wide association studies- GWAS) sugerirem uma possível participação de vários outros genes na suscetibilidade à manifestação da forma multifatorial da DA, o gene APOE, ainda é o único consistente e reproduzivelmente associado à doença. As descobertas derivadas dos GWAS investigando o papel de SNPs coletivamente explicam somente uma pequena porcentagem da variação herdada que contribui para o risco de desenvolver a DA. Atualmente, há novas abordagens para investigar a base genética do restante da variabilidade fenotípica herdada e que pode influenciar a suscetibilidade ao desenvolvimento de doenças complexas. O papel da variação do número de cópias de segmentos de DNA (Copy Number Variation - CNV) na genética de doenças complexas foi demonstrado por diversos estudos nos últimos anos e evidencia que desequilíbrios genômicos também podem contribuir significantemente para a resistência ou susceptibilidade a várias patologias. Outro aspecto que vem assumindo crescente importância é a análise de modificações epigenéticas que podem constituir um mecanismo molecular básico e contribuir diretamente para a patogênese da DA. Logo, este trabalho teve como objetivo principal investigar dois aspectos relacionados à DA: (1) a identificação de CNVs que podem estar contribuindo para o desenvolvimento da forma multifatorial da DA, usando a técnica de array-CGH, e (2) a análise de alterações do padrão global de metilação do DNA no córtex frontal de indivíduos com a forma multifatorial da DA, usando um microarranjo que interroga o status de metilação de 450.000 sítios CpGs. Em nossa investigação sobre desequilíbrios genômicos na DA, identificamos 6 CNVs raras com conteúdo gênico relevante para o fenótipo investigado. Dois indivíduos distintos do grupo DA apresentam microduplicações em genes que codificam diferentes subunidades do mesmo tipo de canal de Ca2+ dependente de voltagem, o tipo L. Além disso, dos outros genes selecionados como especialmente interessantes, 4 estão envolvidos em diferentes processos inflamatórios e 1 é responsável por codificar a enzima nicotinamida fosforibosiltransferase, participante importante da via de biossíntese da molécula nicotinamida adenina dinucleotídeo (NAD). A implicação de um possível envolvimento de mediadores da sinalização celular do Ca2+ e da via de biossíntese da NAD na etiologia da DA também foi reforçada pelos nossos resultados sobre o padrão de metilação do DNA na DA. Dois genes importantes para a homeostasia intracelular do Ca2+ e via de biossíntese da NAD apresentaram sítios CpGs diferenciamente metilados nos sujeitos com DA / Alzheimer\'s disease (AD) is the most common form of dementia in the population, corresponding to 50-60% of all cases. Although clinical diagnosis seems to be accurate, the definitive diagnosis of the disease can only be made by a post mortem neuropathological exam that certifies the presence of the two hallmarks of AD: the accumulation of extracellular senile plaques containing β-amyloid (Aβ) and the intracellular neurofibrillary tangles containing hyperphosphorylated tau protein. Four genes are known to be involved in the etiology of AD, three of them (APP, PSEN1 and PSEN2) are associated to the familial form of the disease, which show autosomal dominant inheritance and correspond to the more severe and rare type of AD. Despite many genome wide association studies (GWAS), APOE still remains the only unequivocal genetic risk factor associated to the multifactorial form of AD. The discoveries from GWAS using SNPs collectively explain only a small percentage of heritable variation that may contribute in AD risk. Currently, new approaches have been used to investigate the genetic basis of the phenotypical variability inheritance that can influence the susceptibility of complex diseases. The important role of DNA copy number variation (CNV) has been demonstrated by several studies over the last years and shows that genomic imbalances may also significantly contribute to resistance or susceptibility to various complex diseases. Additionally, there is now increasing interest in exploring how epigenetic modifications, in particular DNA methylation, could influence complex diseases etiology. Thus, the major aim of this work were to investigate two aspects related to the multifactorial form of AD: (1) identification of rare CNVs, using array-CGH, that could contribute to the development of the disease, and (2) analysis of the DNA methylation pattern in frontal cortex of individuals with AD. In our study, we identified 6 rare CNVs with relevant gene content to the investigated phenotype. Two distinct subjects with AD from our casuistic presented microduplications in genes that encode different subunits of the same type of Ca2+ voltage channel, the L-type. Furthermore, among the other selected genes, four are involved in different inflammatory process and one encodes the nicotinamide phosphoribosyltransferase enzyme, important mediator of nicotinamide adenine dinucleotide (NAD) biosynthesis. The implication of a possible involvement of Ca2+ intracellular signaling mediators and NAD biosynthesis pathway in the etiology of AD was also reinforced by our analysis of DNA methylation pattern. Interestingly, two important genes, one to intracellular Ca2+ homeostasis and the other to NAD biosynthesis pathway presented CpGs sites differently methylated in the AD subjects
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Copy number variations (CNVs) in Brazilian patients with autism spectrum disorder (ASD) / Variações no número de cópias (CNVs) em pacientes brasileiros com transtorno do espectro autista (TEA)

Claudia Ismania Samogy Costa 18 July 2018 (has links)
Autism Spectrum Disorder (ASD) is a heterogeneous group of neurodevelopmental disorders that affects about 1% of the worldwide population and has a strong genetic component. Stereotyped behavior and restricted interests, as well as problems of social interaction and communication characterize ASD. Moreover, in 10% of cases, ASD occurs as a secondary condition in addition to a syndrome, such as Phelan-McDermid syndrome (PMS), which is associated with a great clinical variability. Among genetic factors, copy number variations (CNVs) are one of the most important. However, the clinical significance of many CNVs remains nuclear and there is an underrepresentation of small CNVs associated with ASD in the literature. In this context, this project aimed to 1) characterize large and small CNVs in Brazilian patients with ASD using an array-CGH previously customized in our laboratory. 2) Clinically and genetically describe a cohort of Brazilian patients with PMS, as well as to determine the frequency of this syndrome among Brazilian patients with ASD and other neurodevelopmental disorders. In result, we 1) further validated the customized array-CGH, 2) provided additional evidence of association with ASD for 27 candidate genes, 3) described 15 CNVs never reported in the literature in association with this disorder, 4) presented evidence that around 70% of CNVs found in our cohort are not polymorphism of our population and 5) reinforced the idea of shared molecular pathways among different neurodevelopmental disorders. In addition, we described for the first time a Brazilian cohort of patients with PMS and contributed to the molecular and clinical characterization of this syndrome. We also provided additional evidence of genotype-phenotype association with regard to the presence of renal problems and speech status in patients with PMS and estimated the frequency of this syndrome among Brazilian patients with ASD and intellectual disability (syndromic or not). With these results, we hope to contribute to better understand the ASD and PMS etiology, especially in our population / O Transtorno do Espectro Autista (TEA) corresponde ao um grupo heterogêneo de alterações no neurodesenvolvimento que afeta cerca de 1% da população mundial e apresenta um forte componente genético. O TEA é caracterizado pela presença de comportamento estereotipado e interesses restritos, além de problemas de interação social e comunicação. Além disso, em 10% dos casos, o TEA ocorre como uma condição secundária somada a uma síndrome. Um exemplo é a síndrome de Phelan-McDermid (PMS), associada a uma grande variabilidade clínica. Dentre os fatores genéticos, as variações no número de cópias (CNVs) são um dos mais importantes. No entanto, o significado clínico de muitas CNVs permanece incerto, além de haver juma sub-representação de CNVs pequenas associadas ao TEA na literatura. Dentro deste contexto, este projeto teve como objetivos 1) caracterizar CNVs grandes e pequenas em pacientes brasileiros com TEA utilizando uma lâmina de array-CGH previamente customizada no Laboratório de Genética do Desenvolvimento - USP. 2) descrever clínica e geneticamente uma casuística de pacientes brasileiros com PMS, bem como determinar a frequência desta síndrome em pacientes com TEA e com outras alterações de neurodesenvolvimento. Como resultados, nós 1) validamos a lâmina customizada, 2) fornecemos evidencia adicional de associação com o TEA para 27 genes, 3) descrevemos 15 CNVs nunca reportadas em associação com o transtorno 4) apresentamos evidências de que cerca de 70% das CNVs encontradas em nossa coorte não são polimorfismo de nossa população e 5) reforçamos a ideia de vias moleculares compartilhadas entre diferentes alterações do neurodesenvolvimento. Além disso, descrevemos pela primeira vez uma casuística brasileira de pacientes com PMS e contribuímos para a síndrome. Fornecemos evidência adicional de associação genótipo-fenótipo no que diz respeito à presença de problemas renais e status de fala em pacientes com PMS e estimamos a frequência da síndrome entre pacientes brasileiros com TEA e com deficiência intelectual (sindrômica ou não). Com estes resultados, esperamos ter contribuído para o entendimento da etiologia tanto do TEA, quanto da PMS, sobretudo na nossa população
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Entwicklung und Implementierung von Auswertungswerkzeugen für Hochdurchsatz-DNA-Kopienzahl-Analysen und deren Anwendung auf Lymphomdaten

Kreuz, Markus 18 February 2015 (has links)
Aberrationen in der DNA-Kopienzahl sind häufige genetische Veränderungen bei malignen Lymphomerkrankungen. Zugewinne sowie Deletionen stellen dabei Mechanismen zur Onkogen-Aktivierung sowie Tumorsuppressorgen-Inaktivierung dar und tragen somit zur Pathogenese der Erkrankung bei. Array-CGH und SNP-Array sind Messplattformen, die die genomweite Bestimmung von Kopienzahlaberrationen in einem Experiment ermöglichen. Die bei der Analyse entstehenden Datensätze sind komplex und erfordern automatische Methoden zur Unterstützung der Analyse und Interpretation der Messergebnisse. In dieser Promotionsarbeit wurden Methoden entwickelt, welche die Analyse von Array-CGH- und SNP-Array-Messungen ermöglichen. Diese Methoden wurden für die Auswertung umfangreicher Datensätze von malignen Non-Hodgkin-Lymphomen verwendet. Dabei wurden Lymphome der Entitäten Burkitt-Lymphom, diffus großzelliges B-Zell-Lymphom, Mantelzelllymphom, primäres ZNS-Lymphom und peripheres T-Zell-Lymphom – nicht anderweitig spezifiziert – analysiert. Für die untersuchten Lymphom-Entitäten konnten hierbei zahlreiche neue rekurrente Kopienzahlaberrationen sowie uniparentale Disomien gezeigt werden, die neue Einblicke in die Pathogenese der jeweiligen Erkrankungen erlauben. Darüber hinaus erfolgte ein Vergleich beider Messplattformen anhand eines Datensatzes mit gepaarten Array-CGH- und SNP-Array-Daten. Für die eingesetzten Plattformen (2800k-BAC-Array vs. Affymetrix 250k-Sty-SNP-Array) konnte eine circa zwölffach höhere effektive Auflösung der SNP-Array-Plattform gezeigt werden. Die wesentlichen Ergebnisse dieser Arbeit sind in sieben Publikationen eingeflossen.:Inhaltsverzeichnis Abkürzungsverzeichnis Tabellenverzeichnis Abbildungsverzeichnis 1. Einführung 1.1 Biologischer Hintergrund 1.1.1 Aberrationen der DNA-Kopienzahl und Tumorentstehung 1.1.2 Lymphome 1.2 Motivation und Rationale für die Arbeit 1.3 Array-CGH Analyse 1.4 SNP-Array-Analyse 1.5 Vergleich von Array-CGH und SNP-Array-Analyse 1.6 Assoziationen von DNA-Kopienzahlaberrationen mit RNA-Expression, Lymphomentität sowie klinischen und phänotypischen Faktoren 2.Publikationen 2.1 Publikation 1: “Development and implementation of an analysis tool for array-based comparative genomic hybridization” Methods Inf Med. 2007;46(5):608-13 2.2 Publikation 2: “Recurrent loss of the Y chromosome and homozygous deletions within the pseudoautosomal region 1: association with male predominance in mantle cell lymphoma” Haematologica. 2008 Jun;93(6):949-50 2.3 Publikation 3: “GeneChip analyses point to novel pathogenetic mechanisms in mantle cell lymphoma” Br J Haematol. 2009 Feb;144(3):317-31 2.4 Publikation 4: “Chromosomal imbalances and partial uniparental disomies in primary central nervous system lymphoma.” Leukemia. 2009 Oct;23(10):1875-84 2.5 Publikation 5: “High resolution SNP array genomic profiling of peripheral T cell lymphomas, not otherwise specified, identifies a subgroup with chromosomal aberrations affecting the REL locus” Br J Haematol. 2010 Feb;148(3):402-12 2.6 Publikation 6: “Detection of genomic aberrations in molecularly defined Burkitt\''s lymphoma by array-based, high resolution, single nucleotide polymorphism analysis” Haematologica. 2010 Dec;95(12):2047-55 2.7 Publikation 7: “Patient age at diagnosis is associated with the molecular characteristics of diffuse large B-cell lymphoma” Blood. 2012 Feb 23;119(8):1882-7 2.8 Kennzeichnung des Eigenanteils für alle eingeschlossenen Publikationen 3. Diskussion und Ausblick 4. Zusammenfassung 5. Referenzen 6. Eigene Publikationen 7. Erklärung 8. Danksagung 9. Curriculum vitae
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Nouveaux outils exploratoires et développement d'approches thérapeutiques dans les dysferlinopathies primaires / Development of novel diagnosis tools and exploration of innovative therapeutic approaches in primary dysferlinopathies

Wein, Nicolas 09 December 2010 (has links)
Les dysferlinopathies constituent un groupe de dystrophies musculaires autosomiques récessives comprenantprincipalement la myopathie des ceintures (LGMD) de type 2B et la myopathie distale de Miyoshi. Elles sont causéespar des mutations dans le gène DYSF qui se situe dans la région chromosomique 2p13.1-13.3 (NM_003494). Ce gènecomporte 55 exons répartis sur plus de 230 kb. Il est exprimé principalement dans le muscle squelettique etcardiaque, mais également dans d'autres tissus (placenta...) et types cellulaires tels que lesmonocytes/macrophages. La dysferline (2080 acides aminés, 237 kDa, O75923) fait partie de la famille des Ferlineset comporte 7 domaines C2, senseur de calcium et un domaine transmembranaire C-terminal.La dysferline participe à la formation des tubules-T et à la fusion des myoblastes en myotubes avec lamyoferline (un autre membre de la famille). Elle est localisée au sarcolemme de la fibre musculaire squelettiqueadulte, où elle joue un rôle dans sa réparation. En effet, chez l’homme comme dans les modèles murins, en absencede dysferline, des vésicules, dont la nature n’est pas clairement établie, s’accumulent sous le sarcolemme lésé sansfusionner avec celui-ci. Elle interagirait avec plusieurs protéines membranaires ou cytosoliques, dont certaines(comme la cavéoline 3) sont aussi impliquées dans d’autres formes de LGMD.Au cours de ma thèse, mon travail a été axé d’une part sur l’amélioration des techniques de diagnostic : étudede délétion/duplication dans le gène DYSF par CGH et le développement d’un test permettant d’évaluerl’absence/présence de la dysferline à partir de sang total par des techniques de FACS et d’immunofluorescence.D’autre part j’ai également étudié la pertinence d’approches thérapeutiques. Ainsi, nous avons mis en évidence unelarge délétion homozygote des ¾ du gène DYSF chez une patiente présentant un phénotype modéré dedysferlinopathies. Cette délétion permet cependant la production d’une dysferline tronquée. L’identification decette miniprotéine, la première identifiée à ce jour a permis de mettre en évidence l’aspect en partie modulaire dela dysferline. Une autre donnée sur le caractère modulaire de la dysferline est apparue dans la littérature, cette foismontrant le caractère dispensable de l’exon 32. Sur la base de cette observation clinique, nous avons développéune approche thérapeutique par saut d’exon pour les dysferlinopathies, en démontrant dans un premier temps safaisabilité technique sur l’exon 32.L’ensemble de ces travaux permettront probablement l’amélioration du diagnostic différentiel desdysferlinopathies, tout en fournissant de nouvelles pistes pour comprendre les rôles de la dysferline et offrir ainsides pistes thérapeutiques pour le traitement de patients souffrant de ces pathologies. / Dysferlinopathies are a group of autosomal recessive muscular disorders including mainly limb girdlemuscular dystrophy 2B (LGMD2B) and Miyoshi Myopathy (MM), caused by mutation in DYSF gene (2p13.1-13.3). It is composed by 55 exons spreading on 234 kb of genomic DNA and it is expressed mainly in skeletal and heart muscle and monocytes/macrophages.Dysferlin (2080 amino-acids, molecular weight 237 kDa) belongs to the Ferlin family as Myoferline, which is also expressed in muscle. Dysferlin is involved with Myoferlin in myoblasts fusion and T-tubule formation. In adult skeletal muscle, Dysferlin is localized at the sarcolemma where it plays its main function: the sarcolemma repair after muscular wounding. It has been suggested that Dysferlin allows them to fuse with the plasma membrane in order to provide the required plasma membrane to reseal the wound. During these years, my work was essentially focused on the improvement of diagnosis technique (evaluation of CGH array to detect deletion/duplication event in DYSF gene and development of test able to detect absence/presence of Dysferlin in whole blood), the functional exploration of diagnosis technique (evaluation of CGH array to detect deletion/duplication event in DYSF gene and development of test able to detect absence/presence of Dysferlin in whole blood), and the development of promising therapeutics approaches: AAV gene transfer of a minidysferlin which was identified in patient presenting a mild phenotype and for the first time the demonstration of the feasibility of an exon-skipping therapeutics strategy for dysferlinopathies.
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Využití cytogenetických a molekulárně cytogenetických metod v prenatální diagnostice / Application of cytogenetic and molecular cytogenetic methods in prenatal diagnosis

Rašpličková, Tereza January 2016 (has links)
Foetal anomalies found on ultrasound increase the probability of occurrence of chromosomal abnormalities. They cause about one quarter of all abortions and stillbirths and many of inborn defects in newborns. Karyotype analysis is number one method in prenatal diagnosis whereas array CGH is often used as a verification and supplemental method. The aim of this work was to prove that array CGH gives additional chromosomal findings to karyotypes and could substitute conventional karyotyping as a primary examination method in foetuses with ultrasound findings. We examined 45 prenatal samples using both methods. These samples were referred for invasive examination because of abnormal ultrasound findings. Karyotype analyses found two abnormalities in two (4,4 %) patients and array CGH identified aberrations in five (11,1 %) foetuses whereas both anomalies detected by karyotypes were discovered by array CGH too. This means that array CGH identified about 6,7 % more aberrations than karyotype. Our results correspond with scientific articles which refer that array CGH should replace karyotype not only in postnatal examinations but even in prenatal diagnosis. Keywords: chromosomal aberrations, array CGH, karyotype, prenatal diagnosis, ultrasound

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