Base de dados : LILACS
Pesquisa : G02.111.570.080.708.850 [Categoria DeCS]
Referências encontradas : 5 [refinar]
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Texto completo SciELO Saúde Pública
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Id: lil-610068
Autor: Salcedo-Cifuentes, Mercedes; Domínguez, Martha C; García-Vallejo, Felipe.
Título: Epidemiología genómica y paraparesia espástica tropical asociada a la infección por el virus linfotrópico humano de células T tipo 1 / Genome epidemiology and tropical spastic paraparesis associated with human T-cell lymphotropic virus type 1
Fonte: Rev. panam. salud pública = Pan am. j. public health;30(5):422-430, nov. 2011. ilus, tab.
Idioma: es.
Resumo: OBJETIVO: Caracterizar el ambiente genómico de las secuencias adyacentes al virus linfotrópico humano de células T tipo 1 (HTLV-1) en pacientes con paraparesia espßstica tropical y mielopatía asociada a la infección con HTLV-1 (PET/MAH) de diferentes regiones de Colombia y del Japón. MÉTODOS: Se enfrentaron 71 clones recombinantes con secuencias del genoma humano adyacentes al 5'-LTR de pacientes con PET/MAH, a las bases de datos del Genome Browser y del Gen-Bank. Se identificaron y analizaron estadísticamente 16 variables genómicas estructurales y composicionales mediante el programa informßtico R, versión 2.8.1, en una ventana de 0,5 Mb. RESULTADOS: El 43,0 por ciento de los provirus se localizaron en los cromosomas del grupo C; 74 por ciento de las secuencias se ubicaron en regiones teloméricas y subteloméricas (P < 0,05). Un anßlisis de conglomerados permitió establecer las relaciones jerßrquicas entre las características genómicas incluidas en el estudio; el anßlisis de componentes principales identificó las componentes que definieron los ambientes genómicos preferidos para la integración proviral en casos de PET/MAH. CONCLUSIONES: El HTLV-1 se integró con mayor frecuencia en regiones de la cromatina ricas en islas de citocina fosfato guanina (CpG), de alta densidad de genes y de repeticiones tipo LINE (elemento disperso largo [long interspersed element]) y transposones de ADN que, en conjunto, conformarían los ambientes genómicos blanco de integración. Este nuevo escenario promoverß cambios sustanciales en el campo de la salud pública y en el manejo epidemiológico de las enfermedades infecciosas, y permitirß desarrollar potentes herramientas para incrementar la eficiencia de la vigilancia epidemiológica.

OBJECTIVE: Characterize the genomic environment of the sequences adjacent to human T-cell lymphotropic virus type 1 (HTLV-1) in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in different regions of Colombia and Japan. METHODS: A total of 71 recombinant clones with human genome sequences adjacent to 5' LTR in patients with HAM/TSP were compared to the Genome Browser and GenBank databases. Sixteen structural and compositional genome variables were identified, and statistical analysis was conducted in the R computer program, version 2.8.1, in a 0.5 Mb window. RESULTS: A total of 43.0 percent of the proviruses were located in the group C chromosomes; 74 percent of the sequences were located in the telomeric and subtelomeric regions (P < 0.05). A cluster analysis was used to establish the hierarchical relations between the genome characteristics included in the study. The analysis of principal components identified the components that defined the preferred genome environments for proviral integration in cases of HAM/TSP. CONCLUSIONS: HTLV-1 was integrated more often in chromatin regions rich in CpG islands with a high density of genes and LINE type repetitions, and DNA transposons which, overall, would form the genomic environments targeted for integration. This new scenario will promote substantial changes in the field of public health and in epidemiological management of infectious diseases. It will also foster the development of powerful tools for increasing the efficiency of epidemiological surveillance.
Descritores: Genoma Humano
Vírus 1 Linfotrópico T Humano/genética
Paraparesia Espástica Tropical/genética
Provírus/genética
Sequências Repetidas Terminais/genética
Integração Viral/genética
-Mapeamento Cromossômico
Ilhas de CpG
Cromossomos Humanos/genética
Colômbia/epidemiologia
DNA Recombinante/genética
Paraparesia Espástica Tropical/epidemiologia
Paraparesia Espástica Tropical/virologia
Retroelementos/genética
Alinhamento de Sequência
Análise de Sequência de DNA
Homologia de Sequência do Ácido Nucleico
Limites: Adulto
Idoso
Feminino
Seres Humanos
Masculino
Meia-Idade
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Texto completo SciELO Chile
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Id: lil-538041
Autor: Zhao, Ming; Zhou, Jin yan; Tan, You jiu; Song, Wei wei; Li, Zhi dong; Tan, Hong.
Título: Two LTR retrotransposon elements within the abscisic acid gene cluster in Botrytis cinerea B05.10, but not in SAS56
Fonte: Electron. j. biotechnol;12(1):7-8, Jan. 2009. ilus.
Idioma: en.
Projeto: Chinese Academy of Sciences; . Hi-Tech Research and Development Program (863) of China.
Resumo: The plant hormone abscisic acid has huge economic potential and can be applied in agriculture and forestry for it is considered to be involved in plant resistance to stresses such as cold, heat, salinity, drought, pathogens and wounding. Now overproducing strains of Botrytis cinerea are used for biotechnological production of abscisic acid. An LTR retrotransposon, Boty-aba, and a solo LTR were identified by in silico genomic sequence analysis, and both were detected within the abscisic acid gene cluster in B. cinerea B05.10, but not in B. cinerea SAS56. Boty-aba contains a pair of LTRs and two internal genes. The LTRs and the first gene have features characteristic of Ty3/gypsy LTR retrotransposons. The second gene is a novel gene, named brtn, which encodes for a protein (named BRTN) without putative conserved domains. The impressive divergence in structure of the abscisic acid gene clusters putatively gives new clues to investigate the divergence in the abscisic acid production yields of different B. cinerea strains.
Descritores: Ácido Abscísico/genética
Ácido Abscísico
Ácido Abscísico/uso terapêutico
Botrytis/enzimologia
Botrytis/metabolismo
-Ascomicetos/enzimologia
Petunia/genética
Retroelementos/genética
Sequências Repetidas Terminais
Responsável: CL1.1 - Biblioteca Central


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Texto completo SciELO Chile
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Id: lil-490634
Autor: Vera, Jorge; Valenzuela, Beatriz; Roth, Mónica J; León, Óscar.
Título: Characterization of the long-terminal repeat single-strand tail-binding site of Moloney-MuLV integrase by crosslinking
Fonte: Biol. Res;41(1):69-80, 2008. ilus, graf.
Idioma: en.
Projeto: Fondecyt; . National Institutes of Health.
Resumo: Processing of viral DNA by retroviral integrase leaves a dinucleotide single-strand overhang in the unprocessed strand. Previous studies have stressed the importance of the 5' single-stranded (ss) tail in the integration process. To characterize the ss-tail binding site on M-MuLV integrase, we carried out crosslinking studies utilizing a disintegration substrate that mimics the covalent intermediate formed during integration. This substrate carried reactive groups at the 5' ss tail. A bromoacetyl derivative with a side chain of 6 A was crosslinked to the mutant IN 106-404, which lacks the N-terminal domain, yielding a crosslinked complex of 50 kDa. Treatment of IN 106-404 with N-ethylmaleimide (NEM) prevented crosslinking, suggesting that Cys209 was involved in the reaction. The reactivity of Cys209 was confirmed by crosslinking of a more specific derivative carrying maleimide groups that spans 8A approximately. In contrast, WT IN was not reactive, suggesting that the N-terminal domain modifies the reactivity of the Cys209 or the positioning of the crosslinker side chain. A similar oligonucleotide-carrying iodouridine at the 5'ss tail reacted with both IN 106-404 and WT IN upon UV irradiation. This reaction was also prevented by NEM, suggesting that the ss-tail positions near a peptide region that includes Cys209.
Descritores: DNA Viral/química
Integrases/genética
Vírus da Leucemia Murina de Moloney/enzimologia
Sequências Repetidas Terminais/genética
Integração Viral
-Sequência de Aminoácidos
Sequência de Bases
Sítios de Ligação/genética
Reagentes para Ligações Cruzadas
Cisteína
Integrases/química
Vírus da Leucemia Murina de Moloney/genética
Oligonucleotídeos/genética
Oligonucleotídeos/metabolismo
Limites: Animais
Tipo de Publ: Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-442562
Autor: Guo, X; Xu, G; Zhang, Y; Wen, X; Hu, W; Fan, L.
Título: Incongruent evolution of chromosomal size in rice
Fonte: Genet. mol. res. (Online);5(2):373-389, 2006. ilus, tab, graf.
Idioma: en.
Projeto: National Natural Science Foundation of China.
Resumo: To investigate genome size evolution, it is usually informative to compare closely related species that vary dramatically in genome size. A whole genome duplication (polyploidy) that occurred in rice (Oryza sativa) about 70 million years ago has been well documented based on current genome sequencing. The presence of three distinct duplicate blocks from the polyploidy, of which one duplicated segment in a block is intact (no sequencing gap) and less than half the length of its syntenic duplicate segment, provided an excellent opportunity for elucidating the causes of their size variation during the post-polyploid time. The results indicated that incongruent patterns (shrunken, balanced and inflated) of chromosomal size evolution occurred in the three duplicate blocks, spanning over 30 Mb among chromosomes 2, 3, 6, 7, and 10, with an average of 20.3% for each. DNA sequences of chromosomes 2 and 3 appeared to had become as short as about half of their initial sequence lengths, chromosomes 6 and 7 had remained basically balanced, and chromosome 10 had become dramatically enlarged (approximately 70%). The size difference between duplicate segments of rice was mainly caused by variations in non-repetitive DNA loss. Amplification of long terminal repeat retrotransposons also played an important role. Moreover, a relationship seems to exist between the chromosomal size differences and the nonhomologous combination in corresponding regions in the rice genome. These findings help shed light on the evolutionary mechanism of genomic sequence variation after polyploidy and genome size evolution.
Descritores: Cromossomos de Plantas/genética
Evolução Molecular
Genoma de Planta/genética
Oryza/genética
Sequências Repetidas Terminais/genética
-Sequência de Bases
Duplicação Gênica
Genes de Plantas
Sequências Repetitivas de Ácido Nucleico
Responsável: BR1.1 - BIREME


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Id: lil-292319
Autor: Gómez Román, Raúl; Soler Claudín, Carmen.
Título: La importancia de la Secuencia Terminal Repetida Larga (LTR) en la patogenia del virus de la inmunodeficiencia humana / The importance of the long repeated terminal sequence (LTR) in the pathogenesis of the human immunodeficiency virus
Fonte: Rev. bioméd. (México);11(1):61-71, ene.-mar. 2000. ilus, tab.
Idioma: es.
Resumo: La región terminal repetida larga (LTR) del genoma del virus de la inmunodeficiencia humana funciona como un sitio de control y regulación de la transcripción viral. Pese a que el LTR no codifica proteínas estructurales o accesorias, su función está íntimamente ligada a la replicación viral en respuesta a mitógenos, citocinas e incluso a estímulos generados por agentes infecciosos oportunistas. En esta revisión, se describe la función del LTR en la replicación viral in vitro y su importancia en la patogenia del Síndrome de Inmunodeficiencia Adquirida.
Descritores: HIV/patogenicidade
Síndrome de Imunodeficiência Adquirida/fisiopatologia
Sequências Repetidas Terminais
-Replicação Viral/fisiologia
Retroviridae/patogenicidade
Tipo de Publ: Revisão
Responsável: MX1.1 - CENIDSP - Centro de Información para Decisiones en Salud Pública



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