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.

We describe the genetic diversity of currently transmitted strains of HIV-1 in men who have sex with men (MSM) in Buenos Aires, Argentina between 2000 and 2004. Nearly full-length sequence analysis of 10 samples showed that 6 were subtype B, 3 were BF recombinant and 1 was a triple recombinant of subtypes B, C and F. The 3 BF recombinants were 3 different unique recombinant forms. Full genome analysis of one strain that was subtype F when sequenced in pol was found to be a triple recombinant. Gag and pol were predominantly subtype F, while gp120 was subtype B; there were regions of subtype C interspersed throughout. The young man infected with this strain reported multiple sexual partners and sero-converted between May and November of 2004. This study reported for the first time the full genome analysis of a triple recombinant between subtypes B, C and F, that combines in one virus the three most common subtypes in South America. FindingsThe great genetic diversity of human immunodeficiency virus type 1 (HIV-1) strains have been recognized since early in the epidemic. Phylogenetic analyses of HIV-1 have revealed the presence of at least 9 subtypes (A-D, F-H, J and K) and 16 circulating recombinant forms (CRFs) worldwide [1].In Argentina, previous molecular studies have revealed the presence of two epidemics; the first, among men who have sex with men (MSM), where the viral strains are mostly subtype B, and the second among heterosexuals and injecting drug users where BF recombinants predominate [2,3]. Further sequencing studies have also revealed the presence of a new CRF, the CRF12_BF [4] and subtype

Objective To describe the prevalence and correlates of low serum Se and determine whether HIV, hepatitis C virus (HCV) and/or types of drugs used are associated with serum Se in a cohort of infected and uninfected drug users. Design Independent correlates of low serum Se levels based on data collected from food recalls, physical exams, and clinical status questionnaires were identified using multivariate analysis. Setting Buenos Aires, Argentina Subjects A total of 205 (25 females and 180 males) former and current drug users Results Drug users had an average serum Se level of 69.8±32.8 μg/dl, and 82% were considered deficient (< 85μg/l). Multivariate analyses found that HIV and/or HCV infection had lower mean Se compared to healthy, uninfected drug users (HIV/HCV co-infection: −25.3 μg/l (SE =7.6, p=0.001); HIV alone: −28.9 μg/l (SE=6.9, p<0.001); HCV alone −19.4 μg/l (SE = 7.1, p=0.006). Current and previous drug use was associated with higher serum Se. Cigarette smoking and heavy alcohol consumption were not found to be associated with Se status. Conclusions Low serum Se levels are highly prevalent among drug users in Buenos Aires, Argentina. Se supplementation and/or dietary interventions may be warranted in drug users who are at high risk of HIV and/or HCV infection.

Previous studies have revealed that hepatitis B virus (HBV)/D and HBV/F predominate among blood donors from Buenos Aires, Argentina. In the present study, blood samples from two high-risk groups were analysed: 160 corresponding to street- and hospital-recruited injecting drug users [81.2% showing the 'anti-hepatitis B core antigen (anti-HBc) only' serological pattern] and 20 to hepatitis B surface antigen (HBsAg)(+)/anti-HBc(+) men who have sex with men. HBV genotypes were assigned by polymerase chain reaction amplification followed by restriction fragment length polymorphism and confirmed by nucleotide sequencing of two different coding regions. HBV DNA was detected in 27 injecting drug users (16.9%, occult infection prevalence: 7.7%), and 14 men who have sex with men (70%). HBV/A prevailed among injecting drug users (81.8%) while HBV/F was predominant among men who have sex with men (57.1%). The high predominance of HBV/A among injecting drug users is in sharp contrast to its low prevalence among blood donors (P = 0.0006) and men who have sex with men (P = 0.0137). Interestingly, all HBV/A S gene sequences obtained from street-recruited injecting drug users encoded the rare serotype ayw1 and failed to cluster within any of the known A subgenotypes. Moreover, one of the HBV strains from a hospital-recruited injecting drug user was fully sequenced and found to be the first completely characterized D/A recombinant genome from the American continent. Data suggest that two simultaneous and independent HBV epidemics took place in Buenos Aires: one spreading among injecting drug users and another one sexually transmitted among the homosexual and heterosexual population.