In vitro anthelmintic activity of Siparuna guianensis extract and essential oil against Strongyloides venezuelensis.

New therapeutic approaches are necessary to control strongyloidiasis due to the side effects of, and resistance to, currently available drugs thiabendazole, albendazole, and ivermectin. This study examined the anthelmintic properties of extracts and isolated compounds from Siparuna guianensis against Strongyloides venezuelensis eggs and larvae, using the egg hatching test (EHT) and larval motility test (LMT). Albendazole (0.025 mg/ml) and ivermectin (0.316 mg/ml) were used as the positive controls for the EHT and LMT assays, respectively. Strongyloides venezuelensis eggs or larvae (±50 specimens) were treated with ethanol extract (0.05-1.0 mg/ml), ethyl acetate and aqueous fractions (0.05-0.8 mg/ml), essential oil (0.2-1.0 mg/ml) and α-bisabolol (0.2-1.0 mg/ml) from S. guianensis, and analysed by optical microscopy after 48 h (EHT), or after 24, 48 and 72 h (LMT). All the tested compounds exhibited ovicidal activity equivalent to the positive control and changed the morphology of the eggs. The S. guianensis ethanol extract and aqueous fraction were as effective as the positive control. Phytochemical analysis of the ethanol extract and fractions revealed the presence of phenolic compounds, tannins and flavonoids. Therefore, S. guianensis is effective against S. venezuelensis eggs and larvae in vitro, and can be considered as a potential alternative treatment for strongyloidiasis.

Thymus involution in alloxan diabetes: analysis of mast cells

We previously reported that alloxan-induced diabetes results in reduction in the number and reactivity of mast cells at different body sites. In this study, the influence of diabetes on thymic mast cells was investigated. Thymuses from diabetic rats showed marked alterations including shrinkage, thymocyte depletion, and increase in the extracellular matrix network, as compared to those profiles seen in normal animals. Nevertheless, we noted that the number and reactivity of mast cells remained unchanged. These findings indicate that although diabetes leads to critical alterations in the thymus, the local mast cell population is refractory to its effect. This suggests that thymic mast cells are under a different regulation as compared to those located in other tissues.

Virus da Imunodeficiencia Humana: considerações gerais sobre a especificidade e sensibilidade de metodos laboratoriais para a detecção de anticorpos e antigenos especificos / Human immunodeficiency virus: general aspects concerning laboratorial methods specificity and sensitivity to detect specific antigens and antibodies

O diagnostico laboratorial da infeccao pelo virus da imunodeficiencia humana tipo 1 pode ser feito mediante a aplicacao de testes sorologicos de terceira geracao. Reatividade inespecificas podem, entretanto, ser observadas em diferentess grupos populacionais, para a deteccao de anticorpos contra HIV por metodos imunoenzimaticos, conforme observado na analise de amostras sorologicas de gestantes (3,9 porcento), hepatopatas (3,0 porcento) e populacao pediatrica (1,03 porcento). Os valores de inespecificidade reforcam o conceito de que a deteccao de anticorpos contra HIV deve ser feita pela analise e interpretacao de, ao menos, dois testes de diferentes procedencias, em uma primeira coleta. Metodos de triagem de quarta geracao, que permitem a deteccao simultanea de anticorpos e antigeno p24 do HIV, apresentam sensibilidade comparavel a das metodologias tradicionais, sendo de particular valor no diagnostico precoce da infeccao. Diferentes amostras de sangue de tres pacientes, coletadas em periodos distintos, foram analisadas comparativamente por testes imunoenzimaticos de terceira geracao (Cobas, Axsym e Ortho) e quarta geracao (ELFA HIV DUO). Os resultados demonstram a possibilidade de antecipar a deteccao dos marcadores da infeccao viral em periodos que podem variar de quatro a 12 dias, quando comparados a metodos de terceira geracao, que detectam apenas anticorpos