RESUMO
Se estudia la composición iónica mayoritaria, la concentración de oligoelementos, especialmente flúor y arsénico y su procedencia, en las aguas subterráneas que escurren por sedimentos terciarios y cuaternarios en el norte de la provincia de La Pampa
Assuntos
Geologia , Hidrologia , Qualidade da Água , Química , Água SubterrâneaRESUMO
Se estudia la composición iónica mayoritaria, la concentración de oligoelementos, especialmente flúor y arsénico y su procedencia, en las aguas subterráneas que escurren por sedimentos terciarios y cuaternarios en el norte de la provincia de La Pampa
Assuntos
Qualidade da Água , Geologia , Química , Hidrologia , Água SubterrâneaRESUMO
TT virus (TTV) is a newly discovered DNA virus originally classified as a member of the Parvoviridae. TTV is transmitted by blood transfusion where it has been reported to be associated with mild post-transfusion hepatitis. TTV can cause persistent infection, and is widely distributed geographically; we recently reported extremely high prevalences of viraemia in individuals living in tropical countries (e.g. 74% in Papua New Guinea, 83% in Gambia; Prescott & Simmonds, New England Journal of Medicine 339, 776, 1998). In the current study we have compared nucleotide sequences from the N22 region of TTV (222 bases) detected in eight widely dispersed human populations. Some variants of TTV, previously classified as genotypes 1a, 1b and 2, were widely distributed throughout the world, while others, such as a novel subtype of type 1 in Papua New Guinea, were confined to a single geographical area. Five of the 122 sequences obtained in this study (from Gambia, Nigeria, Papua New Guinea, Brazil and Ecuador) could not be classified as types 1, 2 or 3, with the variant from Brazil displaying only 46-50% nucleotide (32-35% amino acid) sequence similarity to other variants. This study provides an indication of the extreme sequence diversity of TTV, a characteristic which is untypical of parvoviruses.
Assuntos
Genoma Viral , Hepatite Viral Humana/virologia , Parvoviridae/genética , África Ocidental/epidemiologia , Sequência de Aminoácidos , Brasil/epidemiologia , DNA Viral/análise , DNA Viral/genética , Equador/epidemiologia , Variação Genética , Hepatite Viral Humana/epidemiologia , Humanos , Dados de Sequência Molecular , Parvoviridae/isolamento & purificação , Filogenia , Análise de SequênciaRESUMO
Two cases of cutaneous schistosomiasis due to ectopic ova have recently been seen. Both patients presented with abdominal papular lesions, which were found on biopsy to contain schistosoma ova. To reach these abdominal sites mature worms probably migrate from the portal circulation to the paraumbilical veins, where they anastomose with veins of the caval system.