The level of ascorbate peroxidase is enhanced in benznidazole-resistant populations of Trypanosoma cruzi and its expression is modulated by stress generated by hydrogen peroxide

Ascorbate peroxidases (APX) are class I heme-containing enzymes that convert hydrogen peroxide into water molecules. The gene encoding APX has been characterized in 11 strains of Trypanosoma cruzi that are sensitive or resistant to benznidazole (BZ). Bioinformatic analysis revealed the presence of two complete copies of the T. cruzi APX (TcAPX) gene in the genome of the parasite, while karyotype analysis showed that the gene was present in the 2.000-kb chromosome of all of the strains analyzed. The sequence of TcAPX exhibited greater levels of similarity to those of orthologous enzymes from Leishmania spp than to APXs from the higher plant Arabidopsis thaliana. Northern blot and real-time reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed no significant differences in TcAPX mRNA levels between the T. cruzi strains analyzed. On the other hand, Western blots showed that the expression levels of TcAPX protein were, respectively, two and three-fold higher in T. cruzi populations with in vitro induced (17 LER) and in vivo selected (BZR) resistance to BZ, in comparison with their corresponding susceptible counterparts. Moreover, the two BZ-resistant populations exhibited higher tolerances to exogenous hydrogen peroxide than their susceptible counterparts and showed TcAPX levels that increased in a dose-dependent manner following exposure to 100 and 200 µM hydrogen peroxide.

Genotyping of gastroenteric viruses in hospitalised children: first report of norovirus GII.21 in Brazil

This retrospective study (April-September 2003) was designed to investigate the roles of the main viruses responsible for cases of acute infantile gastroenteritis in hospitalised children up to two years of age. The viruses were identified in 64.7% (88/136) of the cases and the detection rates of rotavirus A (RVA), norovirus (NoV) and astrovirus were 41.9% (57/136), 30.3% (24/79) and 12.7% (7/55), respectively. RVA and NoV were detected in 20 of the 24 reported nosocomial infection cases. This study identified the first circulation of the genotype NoV GII.21 in Brazil and highlights the need to establish differential diagnoses through active laboratorial surveillance.

Programa Interunidades de Doutoramento em Enfermagem: 21 anos construindo ciência

O Programa Interunidades de Doutoramento em Enfermagem foi o primeiro a ser criado na América Latina e titulou 290 enfermeiros, até o primeiro semestre de 2004. Este estudo apresenta algumas características das teses defendidas no programa, focalizando as áreas temáticas e métodos de pesquisa utilizados. Foram analisados os resumos de 287 teses, defendidas até o primeiro semestre de 2004. As áreas mais investigadas, até o momento foram: Saúde da Criança, da Mulher, do Adulto/Idoso e Educação. O método de pesquisa quantitativo predominou até final da década de 1980, havendo uma intensa produção de pesquisas no método qualitativo a partir desse período. Ainda na primeira década do programa, os temas passaram a versar sobre os aspectos que relacionam a prática da enfermagem aos contextos políticos e sociais, convergindo para o atual eixo paradigmático do programa: "Bases teóricas, filosóficas, históricas do saber e da prática de enfermagem".