The authors studied the safety and tolerability of subcutaneous interferon beta-1a at different doses in 24 children with clinically definite multiple sclerosis. After a mean treatment period of 44 months, interferon beta-1a was well tolerated in 22 patients, although two experienced possible serious adverse events. Although effectiveness cannot be inferred from this study, the authors did observe a significant reduction in the relapse rate at 22 mug, three times weekly, in the relapsing-remitting subgroup.

SUMMARY -We proposed to investigate subclinical cognitive impairment secondary to chronic Chagas' disease (CCD). No similar study was previously done. The neuropsychological performance of 45 chronic Chagasic patients and 26 matched controls (age, education place and years of residency in endemic area) was compared using the Mini Mental State Exam (MMSE), Weschler Memory Scale (WMS) and the Weschler Adult Intelligent Scale (WAIS). Non-parametric tests and Chi2 were used to compare group means and multivariate statistics in two way frequency tables for measures of independence and association of categorical variables with the disease. Results: Chagasic patients showed lower MMSE scores (p<.004), poor orientation (p<.004), and attention (p<.007). Lower WMS MQ were associated with CCD (Chi2 5.9; p<.01; Fisher test p<.02). Lower WAIS IQ were associated with CCD (Chi2 6.3, p<.01; Fisher test pcOl) being the digit symbol (pc03), picture completion (p<.03), picture arrangement (rx.01) and object assembly (pc03) subtests the most affected. The impairment in non-verbal reasoning, speed of information processing, problem solving, learning and sequencing observed in chronic Chagas disease patients resembles the cognitive dysfunction associated with white matter disease.KEY WORDS: Chagas' disease, cognitive dysfunction, cerebral white matter involvement.Disfuncion cognitiva en la enfermedad de Chagas crónica humana RESUMEN -El objetivo de esta investigación fue determinar compromiso cognitivo en pacientes con enfermedad de Chagas en estadio crónico. Se estudio el perfil cognitivo de 45 pacientes chagasicos crónicos (CC) y 26 controles apareados por edad, educación, lugar y tiempo de residencia en area endémica. El Minimental State (MMSE), 1 a escala de memoria de Weschler (WMS) y el test de Inteligencia de Weschler (WAIS) han sido utilizados para evaluar ambos grupos. Para el estudio estadístico de los datos se utilizaron pruebas no paramétricas, Chi2 y estadistica multivariada en tabla de 2 x 2 para medir la association o independencia de variables categoriales con la presencia de enfermedad. Los resultados mostraron que los pacientes alcanzaban score menor que los controles en el MMSE (p<0.004) debido basicamente a una mas pobre orientación (P<0.004) y atención (p<0.007). Cocientes bajos de memoria en el WMS se asociaron a la presencia de enfermedad (Chi2 5.9, p<0.01; test de Fisher p<0.02). Cocientes bajos de inteligencia en el WAIS se asociaron con la presencia de enfermedad (Chi2 6.3, p<0.01; test de Fisher p<0.01). Los subtests simbolos digitos (p<0.03), completamientos de figuras (p<0.03), ordenamiento de laminas (p<0.01) y rompecabezas (p<0.03) mostraron mayor compromiso. Estos resultados sugieren disfuncion del razonamiento no verbal, disminución de la velocidad de procesado de la información y dificultad en la resolución de problemas nuevos, en la habilidad de secuenciacion y en el aprendizaje. Este conjunto de hallazgos sugiere posible compromiso de la sustancia blanca subcortical en estos enfermos.PALAVRA-LLAVE:...

The prevalence, incidence, risk factors, and molecular genotyping of HIV-1 infection among men who have sex with men (MSM) were assessed through a prospective cohort study. The study was conducted in Buenos Aires from February 2003 to December 2004. Sociodemographic, sexual risk behavior data, and blood samples for HIV testing were collected at baseline and at 6 and 12 months. Cox regression analysis was applied to determine risk factors associated with HIV seroconversion. HIV-positive samples were analyzed by partial (pro/RT) and full-length genome sequencing. Of 811 HIV-negative participants evaluated at baseline, 327 volunteers that fulfilled the inclusion criteria were enrolled. Retention rates at 6 and 12 months were 97.2% and 91.5%, respectively. Twelve MSM seroconverted for HIV infection [incidence rate = 3.9 (95% CI = 2.0-6.7) per 100 person-years]. HIV seroconversion was associated with a greater number of different sexual contacts in the preceding 6 months (> or =10, hazard ratio = 3.3, 95% CI: 1.1-10.4). By partial pro/RT genotyping analysis, 83% HIV-positive samples were subtype B and 17% samples were BF recombinants, most of these being unique recombinant forms. This study describes for the first time the recruitment and follow-up of a cohort of MSM in Argentina. Retention rates and HIV incidence rate were high. These data should be considered as a promising potential population for HIV vaccine trials.

Non-injecting cocaine users from South America are vulnerable to multiple infections and HCV infection appears to occur through the sharing of straws. HCV infection is associated with intimate relationships with IDUs or HIV-seropositive partners, supporting the hypothesis that HCV risk may be due primarily to risk-taking behaviour associated with drugs in this population.

Fruit flies (Diptera: Tephritidae) are a species-rich and economically important group. The phylogenetic relationships among the many taxa are still to be fully resolved and the monophyly of several groups is still to be confirmed. This paper reports a study of the phylogenetic relationships among 23 economically important tephritid species (representing several major lineages of the family) which examines the sequence of a region of mitochondrial DNA encompassing the cytb, tRNA(Ser) and ND1 genes. Substitutions characteristic of particular taxa were found that could help classify members of the family at any developmental stage. The trees obtained by the maximum parsimony, neighbour joining and maximum likelihood methods were generally compatible with present morphological classification patterns. However, the data reveal some characteristics of the phylogenetic relationships of this family that do not agree with present classifications. The results support the probable non-monophyletic nature of the subfamily Trypetinae and suggest that Bactrocera cucurbitae (Coquillet) is more closely related to the genus Dacus than to other species of Bactrocera.