Functional antibodies against G-protein coupled receptors in Beagle dogs infected with two different strains of Trypanosoma cruzi

The interaction of the anti-beta1-adrenergic receptor autoantibodies (β1ARAb) and the anti-muscarinic M2 receptor autoantibodies (M2RAb) with cardiac neurotransmitter receptors were identified in human chronic Chagas cardiomyopathy (CCC) related to the ECG and dysautonomia disturbances. Dogs are considered gold model to the study of Trypanosoma cruzi infection due the clinical similarities with CCC. This study aims to evaluate whether anti-β1ARAb, anti-β2ARAb, and anti-muscarinic M2RAb are generated in Beagle dogs infected by T. cruzi using Y and Berenice-78 strains of T. cruzi. Animals were infected with 4.0 x 103 bloodstream trypomastigotes/kg of body weight and, after 25 months of infection, blood sample was collected, and serum stored at -80°C. Dog serum was treated by ammonium sulphate precipitation and the IgG antibodies isolated and added to the beating neonatal rats’ cardiomyocytes. All T. cruzi-infected dogs developed agonistic β1ARAb, β2ARAb, and M2RAb. Animals infected by Berenice strain presented less β2ARAb and M2RAb activities than dogs infected by Y strain of the parasite. In cardiomyocytes culture, the antibodies recognized an epitope on the second extracellular loop of the receptors which were similar to findings in human Chagas disease. There was no detection of antibody against G protein-coupled receptor in serum from uninfected dogs. In conclusion, both Y and Berenice-78 strains of T. cruzi induced dog antibodies, whose targets located in the second extracellular loop of the adrenergic and muscarinic receptors were similar to those observed in individuals with CCC. Therefore, our findings highlight dogs as a promisor model to investigate pathogenic roles of functional Ab against G-protein coupled receptors

Avaliação microbiológica e físico-química de linguiça toscana no Município de Mossoró, RN

Com o objetivo de avaliar a qualidade microbiológica e físico-química da linguiça toscana comercializada no Município de Mossoró, RN, foram analisadas 28 amostras de seis supermercados, verificando-se o Número Mais Provável (NMP) de coliformes termotolerantes, Salmonella spp. e bactérias psicrotróficas, umidade, pH e atividade de água. Todas as amostras estavam dentro do padrão vigente que estabelece um limite máximo de 5 x 10³ NMP/g-1 para coliformes termotole-rantes conforme a ANVISA. Na contagem de bactérias psicrotróficas houve uma variação de 2,9 x 10¹ a 1,31 x 10(4) UFC/g-1. Das 28 amostras pesquisadas quanto a presença de Salmonella spp., em cinco verificou-se a presença deste micro-organismo em 25 g. Para umidade, todas as amostras encontravam-se dentro da legislação estabelecida (< 70%) e para atividade de água os limites variaram de 0,772 a 0,809. Os valores de pH das amostras estavam entre 5,7 e 6,2. Apesar das amostras analisadas estarem dentro do estabelecido pela legislação brasileira, faz necessária a aplicação de boas práticas, visto que a contaminação por micro-organismos psicrotróficos e Salmonella foi significativa, podendo diminuir a vida de prateleira do produto e causar danos a saúde pública

Hepatitis C virus infection among Brazilian hemophiliacs: a virological, clinical and epidemiological study

We determined and analyzed risk factors of hepatitis C virus (HCV)-infected Brazilian hemophiliacs according to their virological, clinical and epidemiological characteristics. A cross-sectional and retrospective study of 469 hemophiliacs was carried out at a Brazilian blood center starting in October 1997. The prevalence of HCV infection, HCV genotypes and factors associated with HCV RNA detection was determined. The seroprevalence of anti-HCV antibodies (ELISA-3.0) was 44.6% (209/469). Virological, clinical and epidemiological assessments were completed for 162 positive patients. There were seven (4.3%) anti-HCV seroconversions between October 1992 and October 1997. During the same period, 40.8% of the positive anti-HCV hemophiliacs had abnormal alanine transaminase (ALT) levels. Plasma HCV RNA was detected by nested-RT-PCR in 116 patients (71.6%). RFLP analysis showed the following genotype distribution: HCV-1 in 98 hemophiliacs (84.5%), HCV-3 in ten (8.6%), HCV-4 in three (2.6%), HCV-2 in one (0.9%), and not typeable in four cases (3.4%). Univariate analysis indicated that older age (P = 0.017) and abnormal ALT levels (P = 0.010) were associated with HCV viremia, while the presence of inhibitor antibodies (P = 0.024) and HBsAg (P = 0.007) represented a protective factor against the presence of HCV RNA. These findings may contribute to a better understanding of the relationship between HCV infection and hemophilia

IFN-<FONT FACE=Symbol>g</font> in human Chagas' disease: protection or pathology?

An apparently paradoxical role for IFN-<FONT FACE="Symbol">g</font> in human Chagas' disease was observed when studying the pattern of cytokine production by peripheral blood mononuclear cells (PBMC) obtained from two groups of chagasic patients after specific stimulation with Trypanosoma cruzi-derived antigens. The groups studied were 1) patients treated with benznidazole during the acute phase of Trypanosoma cruzi infection and 2) chronically infected untreated patients. In the treated group, higher levels of IFN-<FONT FACE="Symbol">g</font> were produced by PBMC from individuals cured after treatment when compared to non-cured patients. In contrast, in the chronically infected group (not treated) higher levels of IFN-<FONT FACE="Symbol">g</font> were produced by PBMC from cardiac patients in comparison with asymptomatic (indeterminate) patients. This apparently paradoxical role for IFN-<FONT FACE="Symbol">g</font> in human Chagas' disease is discussed in terms of the possibility of a temporal difference in IFN-<FONT FACE="Symbol">g</font> production during the initial stages of the infection (acute phase) in the presence or absence of chemotherapy. The maintenance of an immune response with high levels of IFN-<FONT FACE="Symbol">g</font> production during the chronic phase of the infection may favor cure or influence the development of the cardiac form of the diseas