• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

Estudo da variabilidade gen?tica do papilomav?rus humano e determina??o de alvos moleculares para detec??o e tipagem

Cavalcante, Gustavo Henrique Oliveira 23 February 2018 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-02T15:02:43Z No. of bitstreams: 1 GustavoHenriqueOliveiraCavalcante_DISSERT.pdf: 14332647 bytes, checksum: 07f54cbd966599c411e90b07dbb86ba8 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-05T13:57:34Z (GMT) No. of bitstreams: 1 GustavoHenriqueOliveiraCavalcante_DISSERT.pdf: 14332647 bytes, checksum: 07f54cbd966599c411e90b07dbb86ba8 (MD5) / Made available in DSpace on 2018-04-05T13:57:34Z (GMT). No. of bitstreams: 1 GustavoHenriqueOliveiraCavalcante_DISSERT.pdf: 14332647 bytes, checksum: 07f54cbd966599c411e90b07dbb86ba8 (MD5) Previous issue date: 2018-02-23 / O papilomav?rus humano (HPV) ? um pequeno v?rus de DNA de dupla fita circular, caracterizado como um dos mais comuns agentes sexualmente transmiss?veis no mundo, cuja detec??o e genotipagem acuradas s? s?o poss?veis por meio de t?cnicas de biologia molecular. Diferentes propriedades biol?gicas t?m sido reportadas dentre os mais de 170 tipos j? caracterizados, de maneira que um grupo particular de HPVs est? fortemente relacionado a infec??es persistentes, les?es intraepiteliais de diferentes graus e progress?o para c?nceres tais como cervical, anal, vulvar, vaginal, orofar?ngeo e de p?nis. No presente trabalho foram realizadas an?lises de variabilidade gen?tica e evolu??o molecular nos genomas dos principais HPVs de import?ncia cl?nica. Reconstru??es filogen?ticas e an?lises dos perfis de assinatura gen?tica nos genomas de cada gen?tipo sugeriram a presen?a de subgrupos de HPVs definidos por diferen?as nas sequ?ncias dos genes E1, E6, L1 e L2. Testes de evolu??o em n?vel de DNA revelaram uma atua??o mais forte da sele??o natural em c?dons espec?ficos, mais frequentemente nos genes E1, E2, L1 e L2. A partir dos dados obtidos nas an?lises de variabilidade, foi desenhado um novo conjunto de primers para a detec??o e genotipagem dos HPVs de import?ncia cl?nica por meio da t?cnica de rea??o em cadeia da polimerase (PCR). O gene E1 foi escolhido como alvo molecular devido a presen?a de uma regi?o conservada com tamanho vari?vel entre gen?tipos. O sistema proposto teve sua efici?ncia avaliada in vitro e foi comparado ao protocolo de PCR mais utilizado para detec??o do HPV em amostras cl?nicas. Utilizando a amplifica??o de ?cido nucleico de forma semianinhada (seminested), o sistema proposto foi capaz de detectar com boa sensibilidade alguns dos principais HPVs de alto risco oncog?nico e mostrou melhor especificidade em rela??o aos primers gen?ricos GP5+/6+, mesmo aplicando uma temperatura de anelamento consideravelmente maior. A an?lise do tamanho dos fragmentos amplificados usando a separa??o por eletroforese em gel de agarose pode favorecer a identifica??o do tipo de HPV presente nas amostras, permitindo a discrimina??o entre aqueles mais prevalentes na popula??o e a redu??o do tempo e do custo necess?rios para a identifica??o do agente. Opcionalmente, a separa??o dos produtos em matrizes de alta resolu??o e o sequenciamento direto podem ser usados para a tipagem, possibilitando a identifica??o de uma ampla variedade de gen?tipos de HPV descritos. / Human papillomavirus (HPV) is a small circular double-stranded DNA virus, characterized as one of the most common sexually transmitted agents in the world, whose accurate detection and genotyping is only possible through molecular biology techniques. Different biological properties have been reported among the more than 170 types already characterized, so that a particular group of HPVs is strongly related to persistent infections, intraepithelial lesions of different degrees and progression to cancers such as cervical, anal, vulvar, vaginal, oropharyngeal and penis. In the present work, analyzes of genetic variability and molecular evolution were performed in the genomes of the main clinically important HPVs. Phylogenetic reconstructions and analyzes of genetic signature profiles in the genomes of each genotype suggested the presence of subgroups of HPVs defined by differences in the E1, E6, L1 and L2 gene sequences. Evolution tests at DNA level have shown a stronger acting of natural selection at specific codons, more often in the E1, E2, L1 and L2 genes. From the data obtained in the analyzes of variability, a new set of primers was designed for the detection and genotyping of HPVs of clinical importance by polymerase chain reaction (PCR) technique. E1 gene was chosen as the molecular target due to the presence of a conserved region of variable size among genotypes. The proposed system had its efficiency evaluated in vitro and was compared to the most used PCR protocol for HPV detection in clinical samples. Using the seminested nucleic acid amplification, the proposed system was able to detect some of the major oncogenic HPVs with good sensitivity and showed a better specificity than the generic primers GP5+/6+, even applying a considerably higher annealing temperature. The analysis of the size of the amplified fragments using agarose gel electrophoresis may favor the identification of the HPV type present in the samples, allowing the discrimination between those more prevalent in the population and the reduction of the time and cost necessary for the identification of the agent. Optionally, the separation of products into high resolution matrices and direct sequencing can be used for typing, enabling the identification of a wide variety of HPV genotypes described.

Page generated in 0.0712 seconds