RESUMO
Es bien conocido que tanto los experimentos clínicos aleatorizados así como las revisiones sistemáticas de la literatura y los meta análisis bien conducidos, ofrecen la evidencia más confiable y de mejor calidad, sobre el efecto de las intervenciones en salud. Los autores de revisiones sistemáticas, así como de otros estudios integrativos entre los que se encuentran guías de práctica clínica basadas en evidencia, y análisis económicos, deben tratar de encontrar toda la evidencia relevante en un intento para minimizar el riesgo del sesgo de publicación, que corresponde al hecho que los resultados negativos, es decir aquellos que no encuentran diferencias entre los grupos de intervención, es menos probable que lleguen a la publicación, tardan más tiempo en ser publicados cuando lo hacen y tienden a publicarse más frecuentemente en el idioma nativo del autor cuando no es el inglés; todo esto podría conducir a una distorsión de la evidencia disponible para la toma de decisiones en la práctica clínica. Adicionalmente, algunos resultados de experimentos no son fácilmente recuperados en búsquedas de la literatura porque nunca han sido publicados o lo han hecho en revistas biomédicas no indexadas en las grandes bases de datos1 y 3. Desde mucho tiempo atrás se ha reconocido la importancia de registrar de manera sistemática y prospectiva los experimentos clínicos aleatorizados. Sin embargo, existen varias barreras que han impedido el desarrollo de un registro comprehensivo para los experimentos clínicos a saber: resistencia de la industria farmacéutica y tecnológica, recursos insuficientes para hacer sostenible la empresa del registro a largo plazo, dificultades para forzar a los investigadores a registrar su ensayo y carencia de conocimiento acerca de los problemas de no registrar los experimentos4...
Assuntos
Indústria Farmacêutica , Epidemiologia , Metanálise , Pesquisa , Tecnologia FarmacêuticaRESUMO
BACKGROUND: The use of enemas during labor usually depends on the preference of the attending physician and available resources. However enemas cause discomfort in women and increase the costs of delivery. OBJECTIVES: The objective of this review was to assess the effects of enemas during the first stage of labor on infection rates in mothers and newborns, duration of labor, perineal wound dehiscence in the mother, perineal pain, faecal soiling and costs. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register, Database of Abstracts of Reviews of Effectiveness, Medline and reference lists of articles. SELECTION CRITERIA: Randomised trials in which an enema was administered during the first stage of labor and which included assessment of possible neonatal or puerperal morbidity or mortality. DATA COLLECTION AND ANALYSIS: Selected studies were assessed by three reviewers independently. MAIN RESULTS: Two trials involving 665 women were included. These showed no clear difference in infection rates for puerperal mothers (odds ratio 0.61, 95% confidence interval 0.36 to 1.04) or newborn children. REVIEWER'S CONCLUSIONS: There is not enough evidence to evaluate the use of routine enemas during the first stage of labor.
Assuntos
Enema , Primeira Fase do Trabalho de Parto , Feminino , Humanos , Gravidez , RiscoRESUMO
Previous studies suggest a potential association between human immunoglobulin (Ig) genes and susceptibility to systemic lupus erythematosus (SLE). Ig allotypic determinants seem to confer an increased risk for the disease in various ethnic patient populations. In this study we have examined the pattern of restriction fragment length polymorphisms (RFLP) of constant region lambda (C lambda) light chain genes in a group of 78 Venezuelan patients with SLE and 70 healthy controls. The frequency of the 8-kb allele and the 8/8 genotype was significantly lower in normal Venezuelan controls as compared to healthy British Caucasians (P = 0.0002 and 0.0007 respectively). In turn, Venezuelan controls showed a higher frequency of the 18-kb allele and the 18/18 genotype (P = 0.0002 and 0.0052 respectively). However, there were no statistically significant differences in either parameter between Venezuelan SLE patients and healthy controls. Our study argues against a role for lambda light chain constant region genes in predisposition to SLE.
Assuntos
Doenças Autoimunes/genética , Genes de Imunoglobulinas , Regiões Constantes de Imunoglobulina/genética , Cadeias lambda de Imunoglobulina/genética , Lúpus Eritematoso Sistêmico/genética , Polimorfismo de Fragmento de Restrição , Doenças Autoimunes/etnologia , Doenças Autoimunes/imunologia , Genótipo , Humanos , Lúpus Eritematoso Sistêmico/etnologia , Lúpus Eritematoso Sistêmico/imunologia , Espanha/etnologia , Venezuela/epidemiologia , População Branca/genéticaRESUMO
Due to the resurgence of tuberculosis and the emergence of multidrug-resistant strains, fluoroquinolones (FQ) are being used in selected tuberculosis patients, but FQ-resistant strains of Mycobacterium tuberculosis have rapidly begun to appear. The mechanisms involved in FQ resistance need to be elucidated if the effectiveness of this class of antibiotics is to be improved and prolonged. By using the rapid-growing Mycobacterium smegmatis as a model genetic system, a gene was selected that confers low-level FQ resistance when present on a multicopy plasmid. This gene, lfrA, encodes a putative membrane efflux pump of the major facilitator family, which appears to recognize the hydrophilic FQ, ethidium bromide, acridine, and some quaternary ammonium compounds. It is homologous to qacA from Staphylococcus aureus, tcmA, of Streptomyces glaucescens, and actII and mmr, both from Streptomyces coelicoler. Increased expression of lfrA augments the appearance of subsequent mutations to higher-level FQ resistance.
Assuntos
Anti-Infecciosos/farmacologia , Antiporters/genética , Ciprofloxacina/farmacologia , Resistência Microbiana a Medicamentos , Mycobacterium/metabolismo , Sequência de Aminoácidos , Antiporters/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico Ativo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Genes Bacterianos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Mycobacterium/efeitos dos fármacos , Plasmídeos , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
MHC class II alleles and haplotypes were determined from unrelated individuals and families of the Arhuaco (n = 107), Kogi (n = 42), Arsario (n = 18), and Wayú (n = 88) tribes located in the northern part of Colombia. Class II DRB, DQA1, and DQB1 alleles were determined by PCR-SSO and PCR-RFLP based methods. Four haplotypes, [DRB1*0407, DRB4*0101, DQA1*03, DQB1*0302]; [DRB1*0403, DRB4*0101, DQA1*03, DQB1*0302]; [DRB1*1402/1406, DRB3*0101, DQA1*0501, DQB1*0301]; and [DRB1*0802, DQA1*0401, DQB1*0402], were observed among these four tribes. In addition to these haplotypes, the Wayú Indians showed a frequency of 21.3% for the [DRB1*1602, DRB5*02, DQA1*0501, DQB1*0301] haplotype, 13.1% for the [DRB1*0411, DRB4*0101, DQA1*03, DQB1*0302] haplotype, and 8.1% for the [DRB1*0411, DRB4*0101, DQA1*03, DQB1*0402] haplotype. Red cell antigen typing was used to calculate genetic admixture. The Kogi and Arsario showed no genetic admixture while the Arhuaco tribe showed admixture with genes of African origin and the Wayú showed admixture with Caucasians as well as genes of African origin. These findings were confirmed by the MHC class II allele and haplotype data obtained, as alleles and haplotypes of Caucasian and African origin were detected in the Wayú and Arhuaco and not in the Kogi or Arsario. These studies will be important in disease association and transplantation studies for Amerindian and colombian populations and for correlating genetic traits with the anthropologic and linguistic data available in order to better understand the Amerindian populations.