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1.
Acta cir. bras ; 31(3): 206-211, Mar. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-777090

RESUMO

ABSTRACT PURPOSE: To determine the genetic diversity of MDR P. aeruginosa strains isolated from burn and wound infections in Ahvaz, Iran, by ERIC-PCR. METHODS: From total 99 strains of P. aeruginosa defined as MDR by using drug susceptibility testing, 66 were subjected to ERIC-PCR analysis, comprises 53 strains isolated from burn infection, and 13 randomly selected strains from wound infection with higher resistance to combinations of more numbers of drugs. RESULTS: Eight clusters (I to VIII), and 50 single clones were generated for tested MDR isolates analyzed by ERIC-PCR. The high heterogeneity was observed among the isolates from burn infections including 16 isolates which were categorized in eight clusters and 37 single clones. The isolates in clusters II, III, VI, VIII showed 100% similarity. CONCLUSIONS: The high level of genotypic heterogeneity in P. aeruginosa strains demonstrated no genetic correlation between them. Extremely high drug resistance in isolates from burn, suggests that efficient control measures and proper antibiotic policy should be observed.


Assuntos
Humanos , Pseudomonas aeruginosa/genética , Infecções por Pseudomonas/microbiologia , Infecção dos Ferimentos/microbiologia , Queimaduras/microbiologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Pseudomonas aeruginosa/isolamento & purificação , Sequências Repetitivas de Ácido Nucleico/genética , Reação em Cadeia da Polimerase , Genótipo
2.
Mem. Inst. Oswaldo Cruz ; 110(8): 1003-1009, Dec. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-769825

RESUMO

An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosaisolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding β-lactamases, aminoglycoside-modifying enzymes (AMEs), 16S rRNA methylases, integron-related genes and OprD. Expression of genes coding for efflux pumps and AmpC cephalosporinase were assessed by quantitative PCR. The outer membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The blaSPM-1, blaKPC-2 and blaGES-1 genes were detected in P. aeruginosaisolates in addition to different AME genes. The loss of OprD in nine isolates was mainly due to frameshift mutations, premature stop codons and point mutations. An association of loss of OprD with the overexpression of MexAB-OprM and MexXY-OprM was observed in most isolates. Hyper-production of AmpC was also observed in three isolates. Clonal relationship of the isolates was determined by repetitive element palindromic-PCR and multilocus sequence typing. Our results show that the loss of OprD along with overexpression of efflux pumps and β-lactamase production were responsible for the multidrug resistance in the isolates analysed.


Assuntos
Humanos , Carbapenêmicos/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Mutação , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Resistência beta-Lactâmica/genética , beta-Lactamases/metabolismo , Aminoglicosídeos/metabolismo , Anfotericina B/análogos & derivados , Anfotericina B/metabolismo , Antifúngicos/metabolismo , Brasil , Cefalosporinase/classificação , Cefalosporinase/metabolismo , Códon sem Sentido/metabolismo , Ativação Enzimática/genética , Mutação da Fase de Leitura/genética , Regulação Bacteriana da Expressão Gênica/genética , Proteínas de Membrana Transportadoras/metabolismo , Metiltransferases/metabolismo , Nucleotidiltransferases/metabolismo , Mutação Puntual/genética , Porinas/metabolismo , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/isolamento & purificação , Sequências Repetitivas de Ácido Nucleico , beta-Lactamases/genética
3.
J. pediatr. (Rio J.) ; 91(4): 333-338, July-Aug. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-759340

RESUMO

OBJECTIVE: Report the incidence, epidemiology, clinical features, death, and vaccination status of patients with whooping cough and perform genotypic characterization of isolates of B. pertussis identified in the state of Paraná, during January 2007 to December 2013.METHODS: Cross-sectional study including 1,209 patients with pertussis. Data were obtained through the Notifiable Diseases Information System (Sistema de Informação de Agravos de Notificação - SINAN) and molecular epidemiology was performed by repetitive sequence-based polymerase chain reaction (rep-PCR; DiversiLab(r), bioMerieux, France).RESULTS: The incidence of pertussis in the state of Paraná increased sharply from 0.15-0.76 per 100,000 habitants between 2007-2010 to 1.7-4.28 per 100,000 between 2011-2013. Patients with less than 1 year of age were more stricken (67.5%). Fifty-nine children (5%) developed pertussis even after receiving three doses and two diphtheria-tetanus-pertussis (DTP) boosters vaccine. The most common complications were pneumonia (14.5%), otitis (0.9%), and encephalopathy (0.7%). Isolates of B. pertussis were grouped into two groups (G1 and G2) and eight distinct patterns (G1: P1-P5 and G2: P6-P8).CONCLUSION: The resurgence of pertussis should stimulate new research to develop vaccines with greater capacity of protection against current clones and also encourage implementation of new strategies for vaccination in order to reduce the risk of disease in infants.


OBJETIVO: Relatar a incidência, os aspectos epidemiológicos, clínicos, a morte e a vacinação de pacientes com coqueluche e fazer a caracterização genotípica de isolados de Bordetella pertussisidentificados no Estado do Paraná, de janeiro de 2007 a dezembro de 2013.MÉTODOS: Estudo transversal, incluindo 1.209 pacientes com coqueluche. Os dados foram obtidos no Sistema de Informação de Agravos de Notificação (Sinan) e a epidemiologia molecular foi feita por PCR baseada em sequências repetitivas (rep-PCR; DiversiLab(r), bioMerieux, France).RESULTADOS: A incidência de coqueluche no Estado do Paraná aumentou acentuadamente de 0,15-0,76 por 100.000 habitantes entre 2007-2010 para 1,7-4,28 por 100.000 habitantes entre 2011-2013. Os pacientes com menos de um ano foram os mais afetados (67,5%); 59 crianças (5%) desenvolveram coqueluche mesmo depois de receber três doses da vacina e dois reforços com a vacina tríplice DTP. As complicações mais comuns foram pneumonia (14,5%), otite (0,9%) e encefalopatia (0,7%). Isolados de B. pertussis foram agrupados em dois grupos (G1 e G2) e oito padrões distintos (G1: P1-P5 e G2: P6-P8).CONCLUSÃO: O ressurgimento da coqueluche vem para sugerir novas pesquisas com o objetivo se desenvolverem vacinas com maior capacidade de proteção contra os clones atuais e também implantar novas estratégias de vacinação, a fim de reduzir o risco de doenças em lactentes.


Assuntos
Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Bordetella pertussis/genética , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacinação/estatística & dados numéricos , Coqueluche/epidemiologia , Distribuição por Idade , Bordetella pertussis/isolamento & purificação , Brasil/epidemiologia , Estudos Transversais , Cianose/complicações , Hospitalização/estatística & dados numéricos , Esquemas de Imunização , Incidência , Pneumonia/complicações , Sequências Repetitivas de Ácido Nucleico , Análise de Sequência de DNA , Coqueluche/complicações , Coqueluche/prevenção & controle
4.
Mem. Inst. Oswaldo Cruz ; 107(5): 695-697, Aug. 2012.
Artigo em Inglês | LILACS | ID: lil-643760

RESUMO

Coxiella burnetii is the agent of Q fever , an emergent worldwide zoonosis of wide clinical spectrum. Although C. burnetii infection is typically associated with acute infection, atypical pneumonia and flu-like symptoms, endocarditis, osteoarticular manifestations and severe disease are possible, especially when the patient has a suppressed immune system; however, these severe complications are typically neglected. This study reports the sequencing of the repetitive element IS1111 of the transposase gene of C. burnetii from blood and bronchoalveolar lavage (BAL) samples from a patient with severe pneumonia following methotrexate therapy, resulting in the molecular diagnosis of Q fever in a patient who had been diagnosed with active seronegative polyarthritis two years earlier. To the best of our knowledge, this represents the first documented case of the isolation of C. burnetii DNA from a BAL sample.


Assuntos
Adulto , Humanos , Masculino , Artrite/microbiologia , Coxiella burnetii/genética , DNA Bacteriano/genética , Febre Q/diagnóstico , Sequências Repetitivas de Ácido Nucleico/genética , Transposases/genética , Doença Aguda , Lavagem Broncoalveolar , Coxiella burnetii/isolamento & purificação
5.
Mem. Inst. Oswaldo Cruz ; 106(5): 524-535, Aug. 2011.
Artigo em Inglês | LILACS | ID: lil-597710

RESUMO

The aim of the present study was to compare polymerase chain reaction (PCR)-based methods - spoligotyping and mycobacterial interspersed repetitive units (MIRU) typing - with the gold-standard IS6110 restriction fragment length polymorphism (RFLP) analysis in 101 isolates of Mycobacterium tuberculosis to determine the genetic diversity of M. tuberculosis clinical isolates from Delhi, North India. Spoligotyping resulted in 49 patterns (14 clusters); the largest cluster was composed of Spoligotype International Types (SITs)26 [Central-Asian (CAS)1-Delhi lineage], followed by SIT11 [East-African-Indian (EAI) 3-Indian lineage]. A large number of isolates (75 percent) belonged to genotypic lineages, such as CAS, EAI and Manu, with a high specificity for the Indian subcontinent, emphasising the complex diversity of the phylogenetically coherent M. tuberculosis in North India. MIRU typing, using 11 discriminatory loci, was able to distinguish between all but two strains based on individual patterns. IS6110-RFLP analysis (n = 80 strains) resulted in 67 unique isolates and four clusters containing 13 strains. MIRUs discriminated all 13 strains, whereas spoligotyping discriminated 11 strains. Our results validate the use of PCR-based molecular typing of M. tuberculosis using repetitive elements in Indian isolates and demonstrate the usefulness of MIRUs for discriminating low-IS6110-copy isolates, which accounted for more than one-fifth of the strains in the present study.


Assuntos
Adulto , Feminino , Humanos , Masculino , Adulto Jovem , DNA Bacteriano , Variação Genética , Repetições Minissatélites , Mycobacterium tuberculosis , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Genótipo , Índia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Sequências Repetitivas de Ácido Nucleico
6.
Mem. Inst. Oswaldo Cruz ; 105(4): 391-397, July 2010. tab, ilus
Artigo em Inglês | LILACS | ID: lil-554803

RESUMO

CA88 is the first long nuclear repetitive DNA sequence identified in the blood fluke, Schistosoma mansoni. The assembled S. mansoni sequence, which contains the CA88 repeat, has 8,887 nucleotides and at least three repeat units of approximately 360 bp. In addition, CA88 also possesses an internal CA microsatellite, identified as SmBr18. Both PCR and BLAST analysis have been used to analyse and confirm the CA88 sequence in other S. mansoni sequences in the public database. PCR-acquired nuclear repetitive DNA sequence profiles from nine Schistosoma species were used to classify this organism into four genotypes. Included among the nine species analysed were five sequences of both African and Asian lineages that are known to infect humans. Within these genotypes, three of them refer to recognised species groups. A panel of four microsatellite loci, including SmBr18 and three previously published loci, has been used to characterise the nine Schistosoma species. Each species has been identified and classified based on its CA88 DNA fingerprint profile. Furthermore, microsatellite sequences and intra-specific variation have also been observed within the nine Schistosoma species sequences. Taken together, these results support the use of these markers in studying the population dynamics of Schistosoma isolates from endemic areas and also provide new methods for investigating the relationships between different populations of parasites. In addition, these data also indicate that Schistosoma magrebowiei is not a sister taxon to Schistosoma mattheei, prompting a new designation to a basal clade.


Assuntos
Animais , DNA de Helmintos , Repetições de Microssatélites , Sequências Repetitivas de Ácido Nucleico , Schistosoma , Impressões Digitais de DNA , Genótipo , Filogenia , Reação em Cadeia da Polimerase , Schistosoma mansoni , Schistosoma
7.
Electron. j. biotechnol ; 10(4): 570-581, oct. 2007. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-504118

RESUMO

Cannabis sativa L. is a multiple-use plant that provides raw material for the production of seed oil, natural fiber for textiles, automotive and pulp industries. It has also been used in insulating boards, ropes, varnishes, animal feed, and as medicinal agents. Cannabis has potential to be used for phytoremediation: however, its cultivation is strictly controlled due to its psychoactive nature and usage in producing drugs such as marijuana, and hashish. In this study, psychoactive type Cannabis samples, which were seized from 23 different locations of Turkey, and nine hemp type Cannabis accessions, as well as an unknown accession were used. Our interest was to identify the genetic relatedness of the seized samples and to separate drug and hemp type plants. Inter Simple Sequence Repeats (ISSRs) were employed for analysis based on single plant material (SET1) and bulked samples of them (SET2). Data was analysed via cluster analysis and principal coordinate analysis (PCoA). PCoA analyses, by using SET1 and SET2, were able to efficiently discriminate the seized samples from the fiber type accessions. However, separation of the plants was not clear via unweighted pair-group method using arithmetic average (UPGMA) dendogram in SET1, while they were clearly separated in SET2. Hemp type accessions showed high levels of variation compared to drug type Cannabis both in SET1 and SET2.


Assuntos
Cannabis/genética , Primers do DNA , Variação Genética , Técnicas de Amplificação de Ácido Nucleico , Repetições de Microssatélites/genética , Biologia Molecular/métodos , DNA de Plantas , Marcadores Genéticos , Reação em Cadeia da Polimerase , Polimorfismo Genético , Sequências Repetitivas de Ácido Nucleico/genética
8.
Rev. argent. microbiol ; 39(3): 145-150, jul.-sep. 2007. ilus, tab
Artigo em Inglês | LILACS | ID: lil-634551

RESUMO

In 2003, the incidence of tuberculosis in Argentina showed an increase compared to 2002. The severe national crisis at the end of the 90s has probably strongly contributed to this situation. The goal of this work was to estimate the extent of the spread of the most predominant Mycobacterium tuberculosis strains and to assess the spread of predominant M. tuberculosis clusters as determined by spoligotyping and IS6110 RFLP. The study involved 590 pulmonary, smear-positive TB cases receiving medical attention at health centers and hospitals in Northern Buenos Aires (NBA) suburbs, from October 2001 to December 2002. From a total of 208 clinical isolates belonging to 6 major clusters, 63 (30.2%) isolates had identical spoligotyping and IS6110 RFLP pattern. Only 22.2% were shown to have epidemiological connections with another member of their respective cluster. In these major clusters, 30.2% of the 208 TB cases studied by both molecular techniques and contact tracing could be convincingly attributable to a recently acquired infection. This knowledge may be useful to assess the clonal distribution of predominant M. tuberculosis clusters in Argentina, which may make an impact on TB control strategies.


La incidencia de la tuberculosis en Argentina mostró en 2003 un incremento en comparación con 2002. La grave crisis nacional a fines de los 90 ha probablemente contribuido en gran medida a esta situación. El objetivo del presente trabajo fue determinar la diversidad genética de aislamientos de Mycobacterium tuberculosis y el grado de dispersión de algunas cepas mayoritarias genéticamente relacionadas. El estudio involucró 590 aislamientos clínicos provenientes de muestras respiratorias con examen directo positivo, de pacientes atendidos en los hospitales y centros de salud que conforman la región Gran Buenos Aires Norte (NBA), de octubre de 2001 a diciembre de 2002. De 208 aislamientos que se encontraron en los 6 mayores clusters, 63 (30,2%) tenían patrones idénticos de spoligotyping y de IS6110 RFLP. En el 22,2% de los casos fue posible verificar la conexión epidemiológica con otro miembro del respectivo cluster. Concluimos que el 30,2% de estos agrupamientos principales pueden ser atribuidos a una infección reciente. Estos resultados pueden ser útiles para determinar la distribución clonal de los grupos predominantes de M. tuberculosis en Argentina, lo que puede impactar en las estrategias de control de la tuberculosis.


Assuntos
Adulto , Criança , Feminino , Humanos , Masculino , Transmissão de Doença Infecciosa , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana/métodos , Análise por Conglomerados , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Genótipo , Pessoal de Saúde , Infecções por HIV/epidemiologia , Incidência , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sequências Repetitivas de Ácido Nucleico , População Suburbana , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Tuberculose/epidemiologia , Tuberculose/transmissão
9.
Biol. Res ; 40(1): 85-92, 2007. ilus, tab
Artigo em Inglês | LILACS | ID: lil-456611

RESUMO

This study evaluates the effectiveness of three different molecular techniques, repetitive extragenic palindromic PCR (REP-PCR), enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) and the random amplified polymorphic DNA (RAPD-PCR) for rapid typing of Photobacterium damselae ssp. piscicida strains isolated from different species of marine fish and geographic areas. The results obtained by the three methods showed that RAPD and ERIC-PCR were more discriminative for suitable rapid typing of Ph. damselae ssp. piscicida than REP-PCR. The analysis of DNA banding patterns generated by both molecular methods (RAPD and ERIC-PCR) clearly separated the strains into two main groups that strongly correlated with their geographic origin. Moreover, the REP-PCR analysis was less reproducible than the RAPD and ERIC-PCR methods and does not allow the establishment of genetic groups. RAPD and ERIC-PCR constitute valuable tools for molecular typing of Ph. damselae ssp. piscicida strains, which can be used in epidemiological studies of photobacteriosis infections.


Assuntos
Animais , Técnicas de Tipagem Bacteriana/métodos , Impressões Digitais de DNA/métodos , Variação Genética , Photobacterium/classificação , DNA Bacteriano/genética , Peixes/microbiologia , Photobacterium/genética , Reação em Cadeia da Polimerase/métodos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sequências Repetitivas de Ácido Nucleico/genética
10.
Genet. mol. res. (Online) ; 5(2): 373-389, 2006. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-442562

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.


Assuntos
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
11.
J. bras. med ; 88(3): 47-51, mar. 2005.
Artigo em Português | LILACS | ID: lil-661645

RESUMO

A doença de Huntington (DH) é um distúrbio hereditário autossômico dominante, que está relacionado à expansão das repetições de CAG (citosina-adenina-guanina) no braço curto do cromossomo 4, o que leva à formação de uma proteína mutante associada, principalmente, à destruição neuronal do estriado. Manifesta-se por transtornos motores, cognitivos e neuropsicológicos, evoluindo progressivamente para estado demencial grave. A patogênese da doença ainda apresenta pontos obscuros. No entanto, recentes investigações têm possibilitado maior entendimento de sua origem e evolução, assim como de outras doenças neurodegenerativas


Huntington's disease is a hereditary autosomal dominant disorder which occurs due to the expansion of the repetitions CAG on the short arm of chromosome 4, which leads to the formation of a mutant protein itself associated principally to the destruction of neuronal of the striated tissue. It manifests through motor, cognitive and neuropsychological disorders where it evolves progressively to a serious demential state. The pathogenesis of this disease still presents obscure points although recent investigations made it possible to understand it better in its origin and evolution, the same as with other neurodegenerative diseases


Assuntos
Humanos , Masculino , Feminino , /genética , Doença de Huntington/etiologia , Doença de Huntington/genética , Doença de Huntington/patologia , Proteínas Mutantes/genética , Sequências Repetitivas de Ácido Nucleico , Doenças Neurodegenerativas/etiologia , Degeneração Neural , Proteínas do Tecido Nervoso , Neurônios/patologia , Repetições de Trinucleotídeos/genética
12.
Rev. biol. trop ; 52(3): 491-499, sept. 2004. tab
Artigo em Espanhol | LILACS | ID: lil-501732

RESUMO

Unstable mutations or amplification of DNA tandem repeats sequences constitute a new kind of genetic alteration discovered in the 90's that cause hereditary diseases. This mutation has been found inside or near important genes involved in the normal neurological function in human beings. In some cases, the presence of the amplification causes altered expression of the genes, their inactivation or the synthesis of a protein with new functions. Some common characteristics of these diseases are that they affect the central nervous system and are degenerative in nature. Most of them show genetic anticipation meaning that the severity of the manifestations increases in each generation and appear at an earlier age. In most cases, the severity of the symptoms is positively correlated with the size of the amplification. Twenty illnesses caused by this kind of mutations have been identified so far. Briefly, this work reviews the current knowledge about this topic.


Assuntos
Humanos , Aconselhamento Genético , Mutação/genética , Sequências Repetitivas de Ácido Nucleico/genética , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Predisposição Genética para Doença , Valor Preditivo dos Testes , Transtornos Heredodegenerativos do Sistema Nervoso/diagnóstico
13.
Genet. mol. biol ; 26(4): 505-510, dec. 2003. ilus
Artigo em Inglês | LILACS | ID: lil-355296

RESUMO

Thinopyrum ponticum (2n = 10x = 70, JJJJsJs) belongs to the Triticeae tribe, and is currently used as a source of pathogen resistance genes in wheat breeding. In order to characterize its chromosomes, the number and position of 45S and 5S rDNA sites, as well as the distribution of the repetitive DNA sequences pAs1 and pSc119.2, were identified by fluorescent in situ hybridization. The number of nucleoli and NORs was also recorded after silver nitrate staining. Seventeen 45S and twenty 5S rDNA sites were observed on the short arms of 17 chromosomes, the 45S rDNA was always located terminally. On three other chromosomes, only the 5S rDNA site was observed. Silver staining revealed a high number of Ag-NORs (14 to 17) on metaphase chromosomes, whereas on interphase nuclei there was a large variation in number of nucleoli (one to 15), most of them (82.8 percent) ranging between four and nine. The pAs1 probe hybridized to the terminal region of both arms of all 70 chromosomes. In addition, a disperse labeling was observed throughout the chromosomes, except in centromeric and most pericentromeric regions. When the pSc119.2 sequence was used as a probe, terminal labeling was observed on the short arms of 17 chromosomes and on the long arms of five others. The relative position of 45S and 5S rDNA sites, together with the hybridization pattern of pAs1 and pSc119.2 probes, should allow whole chromosomes or chromosome segments of Th. ponticum to be identified in inbred lines of wheat x Th. ponticum.


Assuntos
Hibridização in Situ Fluorescente , Poaceae , Sequências Repetitivas de Ácido Nucleico , Cromossomos , Marcadores Genéticos
14.
Biol. Res ; 36(2): 241-251, July 2003. ilus, tab
Artigo em Inglês | LILACS | ID: lil-351366

RESUMO

The seasonal adaptation of the teleost Cyprinus carpio to the cyclical changes of its habitat demands physiological compensatory responses. The process involves profound nucleolar adjustments and remarkable changes in rRNA synthesis, which affects ribosomal biosynthesis. In this context, we have demonstrated that the synthesis of several proteins involved in ribosomal biogenesis as protein kinase CK2, ribosomal protein L41 and nucleolin, as well as U3 snoRNP, are differentially regulated in summer-acclimatized carp compared to the cold-season adapted fish. To understand the mechanisms involved in the seasonal regulation of rRNA gene transcription, we have been studying the carp rDNA cistron structure. Because the cis-elements that regulate the expression of the tandem organized ribosomal genes are located in the non-transcribed intergenic spacer (IGS), we analyzed the primary structure of the carp rDNA gene IGS. The gene organization is similar to that described from other vertebrate species, including numerous repetitive sequences, the transcription start site, and some potential cis-elements such as ribosomal enhancers, proximal terminator and transcriptional terminators. Ribosomal DNA is a remarkable case of gene duplication and has been used as a model to test the concerted evolution theory. We performed sequence comparison analyses of 18S rRNA coding sequences from carp with different species, data with which an unrooted phylogram was constructed


Assuntos
Animais , Masculino , Carpas , Genes , RNA Ribossômico , Regulação da Expressão Gênica , Biblioteca Gênica , Dados de Sequência Molecular , Filogenia , Sequências Repetitivas de Ácido Nucleico , RNA Ribossômico , Estações do Ano
15.
Mem. Inst. Oswaldo Cruz ; 98(5): 693-695, July 2003. ilus
Artigo em Inglês | LILACS | ID: lil-344291

RESUMO

A simple, quick and sensitive method was used to detect telomerase activity in Plasmodium falciparum. The telomeric repeat amplification protocol (TRAP assay) was modified using electrophoresis and staining with SYBR-green I to detect telomerase activity in a range of 10² to 10(7) parasites. This might be a useful way to ascertain telomerase activity in different types of nontumor cells


Assuntos
Animais , Plasmodium falciparum , Reação em Cadeia da Polimerase , Telomerase , Telômero , Eletroforese em Gel de Poliacrilamida , Sequências Repetitivas de Ácido Nucleico
16.
Braz. j. infect. dis ; 7(1): 32-43, Feb. 2003.
Artigo em Inglês | LILACS | ID: lil-351151

RESUMO

Staphylococcus aureus has long been recognised as an important pathogen in human disease. Serious staphylococcal infections can frequently occur in inpatients and may lead to dire consequences, especially as to therapy with antimicrobial agents. The increase in the frequency of Methicillin-Resistant Staphylococcus aureus (MRSA) as the causal agent of nosocomial infection and the possibility of emergence of resistance to vancomycin demands a quick and trustworthy characterization of isolates and identification of clonal spread within hospitals. Enough information must be generated to permit the implementation of appropriate measures for control of infection, so that outbreaks can be contained. Molecular typing techniques reviewed in this manuscript include: plasmid profile analysis, analysis of chromosomal DNA after enzymatic restriction, Southern blotting, pulsed field gel electrophoresis (PFGE), techniques involving polymerase chain reaction and multilocus sequence typing (MLST). Repetitive DNA Sequence PCR (rep-PCR) may be used for screening due to its practicality, low cost and reproducibility. Because of its high discriminatory power Pulsed-Field Gel Electrophoresis (PFGE) still remains the gold standard for MRSA typing. New techniques with higher reproducibility and discriminatory power, such as Multi-Locus Sequence Typing (MLST), are appearing. These are mostly useful for global epidemiology studies. Molecular typing techniques are invaluable tools for the assessment of putative MRSA outbreaks and so should be extensively used for this purpose


Assuntos
Humanos , Técnicas de Tipagem Bacteriana , Infecção Hospitalar/microbiologia , DNA Bacteriano/análise , Resistência a Meticilina/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Técnicas de Tipagem Bacteriana/métodos , Técnicas de Tipagem Bacteriana/normas , Brasil/epidemiologia , Cromossomos Bacterianos/química , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Eletroforese em Gel de Campo Pulsado , Genótipo , Reação em Cadeia da Polimerase , Plasmídeos/análise , Sequências Repetitivas de Ácido Nucleico , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética
17.
Mem. Inst. Oswaldo Cruz ; 97(suppl.1): 71-75, Oct. 2002. ilus, tab
Artigo em Inglês | LILACS | ID: lil-325017

RESUMO

In the last decade microsatellites have become one of the most useful genetic markers used in a large number of organisms due to their abundance and high level of polymorphism. Microsatellites have been used for individual identification, paternity tests, forensic studies and population genetics. Data on microsatellite abundance comes preferentially from microsatellite enriched libraries and DNA sequence databases. We have conducted a search in GenBank of more than 16,000 Schistosoma mansoni ESTs and 42,000 BAC sequences. In addition, we obtained 300 sequences from CA and AT microsatellite enriched genomic libraries. The sequences were searched for simple repeats using the RepeatMasker software. Of 16,022 ESTs, we detected 481 (3 percent) sequences that contained 622 microsatellites (434 perfect, 164 imperfect and 24 compounds). Of the 481 ESTs, 194 were grouped in 63 clusters containing 2 to 15 ESTs per cluster. Polymorphisms were observed in 16 clusters. The 287 remaining ESTs were orphan sequences. Of the 42,017 BAC end sequences, 1,598 (3.8 percent) contained microsatellites (2,335 perfect, 287 imperfect and 79 compounds). The 1,598 BAC end sequences 80 were grouped into 17 clusters containing 3 to 17 BAC end sequences per cluster. Microsatellites were present in 67 out of 300 sequences from microsatellite enriched libraries (55 perfect, 38 imperfect and 15 compounds). From all of the observed loci 55 were selected for having the longest perfect repeats and flanking regions that allowed the design of primers for PCR amplification. Additionally we describe two new polymorphic microsatellite loci


Assuntos
Animais , Bases de Dados de Ácidos Nucleicos , Biblioteca Genômica , Repetições de Microssatélites , Schistosoma mansoni , Sequência de Bases , Brasil , Biologia Computacional , DNA de Helmintos , Reação em Cadeia da Polimerase , Polimorfismo Genético , Sequências Repetitivas de Ácido Nucleico , Análise de Sequência de DNA
18.
Säo Paulo med. j ; 120(3): 77-79, May 2002. ilus, tab
Artigo em Inglês | LILACS | ID: lil-312170

RESUMO

CONTEXT: Human DNA identification is a powerful tool for paternity cases as well as for criminal investigation, in which biological evidence is typed after collection from crime scenes and for the identification of human remains. OBJECTIVE: Identification of a criminal in a rape case with 4 suspects using STR and VNTR DNA analysis. TYPE OF STUDY: Forensic DNA analysis. SETTING: DNA Diagnostic Laboratory, Universidade Estadual do Rio de Janeiro, Brazil. PARTICIPANTS: Blood from 4 suspects and the victim, and skin from the fetus. PROCEDURES: Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: Three of the suspects were excluded and one of them was identified as the biological father of the fetus after typing with CTT and FFv Multiplexes. Complementary DNA typing at 3 VNTR loci was also carried out. CONCLUSIONS: After typing four suspects using 6 STR loci, one of them was identified as the biological father of the fetus. In order to significantly enhance the Combined Paternity Index (PI), complementary DNA typing in 3 VNTR loci was carried out. The included suspect was found to be the biological father with a PI of 412,860 (Probability of Paternity: 99.9997 percent)


Assuntos
Humanos , Masculino , Feminino , Adolescente , DNA , Paternidade , Estupro , Brasil , Abuso Sexual na Infância , Frequência do Gene , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Sequências Repetitivas de Ácido Nucleico
19.
Biomédica (Bogotá) ; 20(1): 49-58, mar. 2000. ilus
Artigo em Espanhol | LILACS | ID: lil-278062

RESUMO

Las secuencias repetitivas son componentes estructurales de los genomas eucariotes. Se desconoce la función de la mayoría de ellas, pero, al parecer, no son simplemente ADN egoísta sino que intervienen en procesos de recombinación y regulación génica. En este estudio se estableció la localización subtelomérica de la secuencia repetitiva PFCOL692 en los cromosomas de Plasmodium falciparum, a través de la caracterización de cuatro clones de la genoteca lambda EMBL4/PFCOL692, que contenían insertos entre 15 y 23Kb de ADN genómico del parásito; esta caracterización se hizo mediante análisis de restricción y la posible ubicación de PFCOL692 en el genoma se exploró utilizando sondas específicas para las regiones teloméricas (pTB4.1) y subtelomérica (pRep20) de los cromosomas de P. falciparum. El análisis de los mapas de restricción obtenidos permitió plantear una posible ubicación de PFCOL692 en el extremo de los cromosomas del parásito, donde las copias de esta secuencia se encuentran agrupadas en un segmento del subtelómero y con una posición conservada con respecto a la secuencia pRep20. Se sugiere, además, que PFCOL692 no se encuentra en el límite entre el subtelómero y el telómero


Assuntos
Plasmodium falciparum , Sequências Repetitivas de Ácido Nucleico , Telômero
20.
São Paulo; s.n; 1999. 139 p. ilus, tab.
Tese em Português | LILACS | ID: lil-235230

RESUMO

A partir de 1993 começou a ser descrita a presença de instabilidade de microssatélites (MSI) em tumores de cólon de pacientes portadores da síndrome do câncer de cólon hereditário não poliposo (HNPCC). A MSI é caracterizada pela perda ou ganho de unidades respectivas em regiões do DNA contendo mono, di, tri ou tetranucleotídeos dispostos seguidamente. Estas alterações começaram a ser descritas também em tumores esporádicos de cólon, endométrio, estômago, pâncreas, pulmão e mama. Analisamos a MSI em 42 amostras de tumores gástricos esporádicos, em dez regiões contendo repetições de dinucleotídeos (CA)n, por reação em cadeia da polimerase (PCR) radioativa e gel de poliacrilamida desnaturante. Das 42 amostras analisadas, 10 apresentaram pelo menos um loco alterado, com alelos extras no tecido tumoral mas não no normal correspondente, sendo classificadas como MSI+(10/42 - 23,8 por cento)...


Assuntos
Repetições de Dinucleotídeos , Neoplasias Gástricas/genética , Receptores de Fatores de Crescimento Transformadores beta , Sequências Repetitivas de Ácido Nucleico , DNA , Eletroforese em Gel de Poliacrilamida , Linfócitos , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
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