RESUMO
We report the first study on prevalence of antiretroviral drug-associated resistance mutations in Venezuela. Protease and reverse transcriptase (RT) coding regions were analyzed in DNA samples obtained from 100 HIV-1-infected individuals. Primary resistance mutations to RT inhibitors were identified in 26% of patients treated with these drugs. Transmission of HIV-1-resistant strains was detected in a drug-naive patient (3%). Primary resistance mutations to protease inhibitors (PIs) were present in 9% of the 44 PI-treated patients and in 1 PI-naive individual. Phylogenetic analysis of these samples has resulted in the most extensive survey, to date, of HIV-1 genetic forms circulating in Venezuela. Ninety-nine samples clustered with subtype B, and 1 individual harbored the first B/F recombinant virus reported in Venezuela, with protease clustering with subtype F and RT with subtype B. In addition, this isolate had a new insertion (Glu-34 duplication) in the protease gene.
Assuntos
Infecções por HIV/virologia , Protease de HIV/genética , Transcriptase Reversa do HIV/genética , HIV-1/genética , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Resistência Microbiana a Medicamentos , Quimioterapia Combinada , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , HIV-1/efeitos dos fármacos , Humanos , Masculino , Dados de Sequência Molecular , Mutação , Filogenia , Inibidores de Proteases/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Venezuela/epidemiologiaAssuntos
Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Transcriptase Reversa do HIV/genética , HIV-1/genética , Recombinação Genética , Adulto , Argentina/epidemiologia , Feminino , Genes Virais , Protease de HIV/genética , HIV-1/classificação , Humanos , Masculino , Filogenia , Reação em Cadeia da PolimeraseRESUMO
A mini-Tn5-Hg insertion mutant derived from Pseudomonas aeruginosa W51D (W51M1) was isolated in which mini-Tn5 insertion disrupted the motR gene showing that it forms part of the cluster involved in bacterial motility and chemotaxis. Characterization of the W51M1 motility behavior, and also of a PAO1 motR::mini-Tn5-Hg mutant, suggests that the product of the motR gene is a negative regulator of bacterial motility which controls the number of flagella per cell.
Assuntos
Proteínas de Bactérias/genética , Pseudomonas aeruginosa/genética , Sequência de Aminoácidos , Proteínas de Bactérias/fisiologia , Sequência de Bases , Quimiotaxia/genética , Quimiotaxia/fisiologia , Elementos de DNA Transponíveis/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Dados de Sequência Molecular , Movimento/fisiologia , Mutagênese Insercional , Mutação , Óperon , Pseudomonas aeruginosa/fisiologia , Análise de Sequência de DNA , Fator sigma/genéticaRESUMO
Random Tn5 mutagenesis over Azotobacter vinelandii mucoid strain ATCC 9046 produced strain LA21, a non-mucoid, non-encysting mutant, carrying the Tn5 insertion within a gene homologous to algK from Pseudomonas aeruginosa encoding a periplasmic protein. algK, algJ and algG were shown to be transcribed as part of the palg8-alg44-algK-algJ-algG operon. A non-polar algK mutant was constructed and showed a non-mucoid phenotype, indicating that algK is essential for alginate production.
Assuntos
Azotobacter vinelandii/genética , Proteínas de Bactérias/genética , Genes Bacterianos , Mutação , Alginatos/metabolismo , Azotobacter vinelandii/metabolismo , Azotobacter vinelandii/ultraestrutura , Sequência de Bases , Mapeamento Cromossômico , Dessecação , Ácido Glucurônico , Ácidos Hexurônicos , Microscopia Eletrônica , Família Multigênica , Mutagênese Insercional , Óperon , Fenótipo , Plasmídeos/genética , Regiões Promotoras Genéticas , Pseudomonas aeruginosa/genética , Transcrição GênicaRESUMO
En esta revisión de las investigaciones publicadas sobre la infección por el virus de la inmunodeficiencia humana (VIH) y los factores de riesgo entre trabajadoras sexuales, se sintetizan los resultados de estudios de seroprevalencia efectuados en distintos países y se analizan los diferentes patrones de transmisión entre dichas trabajadoras en diversas zonas geográficas. Las tasas más altas de infección por el VIH se producen en la zona subsahariana del Africa, donde la amplia difusión de enfermedades de transmisión sexual puede contribuir de manera importante a perpetuar la transmisión. En Europa y América del Norte el uso de drogas inyectadas sigue siendo el factor que más se asocia con la infección por el VIH entre las trabajadoras sexuales, mientras que en America Latina y partes del Asia se observa un patrón mixto de transmisión por contacto heterosexual e inyección de drogas. La presente revisión también abarca estudios sobre los factores de riesgo asociados con la infección por el VIH entre las trabajadoras sexuales, factores que incluyen el consumo de drogas, el comportamiento sexual, la presencia de enfermedades de transmisión sexual y el empleo de condones. Se examinan, además, algunos estudios realizados en clientes de trabajadoras sexuales. Por último, se proponen directrices para futuras investigaciones en esta área y se examinan las diversas intervenciones que hay que realizar para reducir la transmisión del VIH entre las trabajadoras sexuales
Se publica en inglés en Bull. WHO. Vol. 71(3/4), 1993
Assuntos
Síndrome da Imunodeficiência Adquirida , América Latina , Austrália , Júpiter , Ásia , África , Região do CaribeRESUMO
We report here the formation of symbiotic plasmids (pSyms), by genetic recombination between rearranged pSyms, which lack symbiotic information, and resistance plasmids carrying parts of different symbiotic plasmids (R's). This recombination was found to occur both between plasmids derived from different Rhizobium phaseoli isolates, and between plasmids derived from strains obtained from the same original isolate. We also present evidence on the formation of a functional symbiotic plasmid by recombination of an R', carrying nif and nod genes from strain CFN42, and an indigenous plasmid present in this strain (pCFN42e), which was thought to be unrelated to its symbiotic plasmid (pCFN42d). These data are discussed with respect to the stability and transfer of Rhizobium symbiotic information.
Assuntos
Plasmídeos/genética , Recombinação Genética , Rhizobium/genética , Simbiose , Resistência Microbiana a Medicamentos/genética , Temperatura Alta , Hibridização de Ácido Nucleico , Microbiologia do SoloRESUMO
Rhizobium leguminosarum biovar phaseoli CFN23 loses its ability to nodulate beans at a high frequency because of a deletion of part of its symbiotic (pSym) plasmid (Soberón-Chávez et al., 1986). We report here that at least 80 kb of pSym are deleted upon loss of the symbiotic phenotype; the deletion removes the nitrogenase structural nifHDK and the common nodABC genes. The size of the deleted pSym is not reduced, since it is accompanied by an amplification of other pSym plasmid sequences. This genetic rearrangement is similar to the deletion and amplification of yeast mitochondrial DNA leading to 'petite' mutations.
Assuntos
DNA Bacteriano/biossíntese , Plasmídeos/genética , Rhizobium/genética , Simbiose/genética , Southern Blotting , Deleção Cromossômica , Fabaceae/microbiologia , Amplificação de Genes , Genes Bacterianos , Fixação de Nitrogênio/genética , Nitrogenase/genética , Fenótipo , Plantas MedicinaisAssuntos
Diarreia Infantil/terapia , Hidratação , Sódio/administração & dosagem , Humanos , Lactente , MasculinoRESUMO
This is the first study on genetic markers in Mexican Mestizos with multiple sclerosis (MS). Patients were born in Mexico, had no family history of MS are middle-class, and have a high-level education. HLA class I, class II determinants, C2, C4, BF, GLO-1, ABO, and Rb red cell systems were analyzed and compared with results of 295 controls. Measles antibodies, glucose, IgG, total proteins, and cell count were measured in cerebrospinal fluid; anti-neuron, T-cell, and B-cell antibodies were determined in serum. MS in Mexican Mestizos was clinically similar to MS reported in high prevalence countries. DRw6, as previously found in Japanese patients, and its subtype, DRw13, were increased in patients in our study (pc = 0.0007, pc = 0.01, respectively), and the combination A3, B7, DR2, was also elevated (pc = 0.003). The polygenicity of the disease is emphasized by the excess of AB group carriers (pc = 0.01). IgG levels were high in patients with DR2 or DRw6 and 67% of the latter had anti-T cell antibodies. Severity of the disease was also related to the DR markers. It is suggested that at least two HLA-DR linked genes and the industrialized environment are important for the expression of MS in Mestizos.
Assuntos
Antígenos de Histocompatibilidade Classe II/genética , Esclerose Múltipla/genética , Sistema ABO de Grupos Sanguíneos/genética , Adulto , Autoanticorpos/imunologia , Linfócitos B/imunologia , Feminino , Marcadores Genéticos , Genótipo , Antígenos HLA/genética , Antígenos HLA/imunologia , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunoglobulina G/análise , Masculino , México , Esclerose Múltipla/imunologia , Sistema do Grupo Sanguíneo Rh-Hr/genética , Linfócitos T/imunologiaRESUMO
La reciente constatación de que el síndrome de inmunodeficiencia adquirida (SIDA) podría afectar en forma especial a homosexuales, drogadictos por vía intravenosa y hemofílicos motivó el inicio, en marzo de 1983, de un seguimiento clínico, inmunológico y microbiológico en 67 pacientes hemofílicos que reciben atención en la Unidad de Hemofilia de la Ciudad Sanitaria La Paz de Madrid. De ellos, 31 eran asintomáticos y 36 portadores de alguno de los signos o síntomas prodrómicos del SIDA. Los resultados obtenidos demostraron, em primer lugar, que un alto número de pacientes hemofílicos presentaban inversión del cociente de linfocitos T inductores/linfocitos T supresores sin que existiera una relación clara con la presencia de signos y síntomas asociados con el SIDA; en segundo lugar, la presencia de infecciones recientes y pasadas en proporciones similares en pacientes sintomáticos y asintomáticos, así como la mayor frecuencia de infecciones recientes por virus del grupo herpes en los hemofílicos con síntomas clínicos, y, en tercer lugar, que uno de los casos evolucionó hacia un cuadro compatible con SIDA. Estos resultados sugieren la existencia del riesgo de que los enfermos de hemofilia padezcan el SIDA, por lo debe mantenerse un control médico especial sobre ellos
Assuntos
Humanos , Hemofilia A/complicações , Grupos de Risco , Síndrome da Imunodeficiência Adquirida/imunologia , Hepatite B/complicações , Risco , Sarcoma de Kaposi/complicações , Linfócitos T/imunologiaRESUMO
In keeping with the global goal of health for all, the National Development Plan of Mexico describes health as a social right. To give effect to this right it is felt that the health sector must be restructured so as, among other purposes, to improve the coverage of services and strengthen the coordination of education institutions and social security agencies with health establishments, and to make the training of health personnel responsive to the country's real needs. No profession is better suited than nursing to the diversity of tasks in primary care. The authors describe the key role of this personnel in extending the coverage of health services to the entire population. They enumerate the range of basic--technical, administrative and educational--functions performed by nurses, and some factors that reinforce and others that restrict the contribution of nursing to primary health care in Mexico.