Human immunodeficiency virus bDNA assay for pediatric cases

Techniques to quantify plasma HIV-1 RNA viral load (VL) are commercially available, and they are adequate for monitoring adults infected by HIV and treated with antiretroviral drugs. Little experience on HIV VL has been reported in pediatric cases. In Argentina, the evaluation of several assays for VL in pediatrics are now being considered. To evaluate the pediatric protocol for bDNA assay in HIV-infected children, 25 samples from HIV-infected children (according to CDC criteria for pediatric AIDS) were analyzed by using Quantiplex HIV RNA 2.0 Assay (Chiron Corporation) following the manufacturer's recommendations in a protocol that uses 50 microliters of patient's plasma (sensitivity: 10,000 copies/ml). When HIV-RNA was not detected, samples were run with the 1 ml standard bDNA protocol (sensitivity: 500 HIV-RNA c/ml). Nine samples belonged to infants under 12 months of age (group A) and 16 were over 12 months (group B). All infants under one year of age had high HIV-RNA copies in plasma. VL ranged from 30,800 to 2,560,000 RNA copies/ml (median = 362,000 c/ml) for group A and < 10,000 to 554,600 c/ml (median = < 10,000) for group B. Only 25 of children in group B had detectable HIV-RNA. By using the standard test of quantification, none of the patients had non detectable HIV-RNA, ranging between 950 and 226,200 c/ml for group B (median = 23,300 RNA c/ml). The suggested pediatric protocol could be useful in children under 12 months of age, but 1 ml standard protocol must be used for older children. Samples with undetectable results from children under one year of age should be repeated using the standard protocol.

Potentialization of the lactoperoxidase system for preservation of raw milk in the tropics

Se aumentó la capacidad antimicrobiana del sistema lactoperoxidas, mediante la adición de tiocianato y peróxido de hidrógeno en cantidades mayores a las sugeridas por otros autores. Los resultados de laboratorio y las pruebas de campo revelaron que por otros autoes. Los resultados de laboratorio y las pruebas de campo revelaron que el sistema potencializado pudo preservar leches de baja calidad microbiológica, a temperaturas "tropicales" por períodos más largos que al usarlo como se recomienda en la literatura. Se pudo conservar leches a 20-C por más de un día, sin menoscabo de su calidad general. A 36-C, las leches no acusaron desarrollo de acidez durante el término de 10 horas. Las pruebas realizadas en condiciones reales de recolección y transporte validaron los resultados de laboratorio. Se logró así probar que el sistema lactoperoxidasa es viable de uso en la práctica, y que su poder bactericida/bacteriostático sobre la flora deterioradora de la leche puede aumentarse a fin de superar las condiciones especialmente adversas que involucra el menejo de la leche en los trópicos