ASP-2/Trans-sialidase chimeric protein induces robust protective immunity in experimental models of Chagas' disease.

Immunization with the Amastigote Surface Protein-2 (ASP-2) and Trans-sialidase (TS) antigens either in the form of recombinant protein, encoded in plasmids or human adenovirus 5 (hAd5) confers robust protection against various lineages of Trypanosoma cruzi. Herein we generated a chimeric protein containing the most immunogenic regions for T and B cells from TS and ASP-2 (TRASP) and evaluated its immunogenicity in comparison with our standard protocol of heterologous prime-boost using plasmids and hAd5. Mice immunized with TRASP protein associated to Poly-ICLC (Hiltonol) were highly resistant to challenge with T. cruzi, showing a large decrease in tissue parasitism, parasitemia and no lethality. This protection lasted for at least 3 months after the last boost of immunization, being equivalent to the protection induced by DNA/hAd5 protocol. TRASP induced high levels of T. cruzi-specific antibodies and IFNγ-producing T cells and protection was primarily mediated by CD8+ T cells and IFN-γ. We also evaluated the toxicity, immunogenicity, and efficacy of TRASP and DNA/hAd5 formulations in dogs. Mild collateral effects were detected at the site of vaccine inoculation. While the chimeric protein associated with Poly-ICLC induced high levels of antibodies and CD4+ T cell responses, the DNA/hAd5 induced no antibodies, but a strong CD8+ T cell response. Immunization with either vaccine protected dogs against challenge with T. cruzi. Despite the similar efficacy, we conclude that moving ahead with TRASP together with Hiltonol is advantageous over the DNA/hAd5 vaccine due to pre-existing immunity to the adenovirus vector, as well as the cost-benefit for development and large-scale production.

Avaliação laboratorial da toxicidade molecular em eritrócitos talassêmicos / Laboratorial evaluation of molecular toxicity in thalassemic erythrocytes

Oxygen-derived free radical damage is associated with the molecular toxicity of hemoglobin. Especially in thalassemia syndromes, this toxicity has a relationship with "free" alpha globin concentrations. This study of beta thalassemia trait blood samples from 39 individuals shows that the evaluation of methemoglobin is a sensitive method of indicating molecular toxicity and the superoxide dismutase concentration revealing the intensity of oxidative stress of this process.

Fatores de risco da constipação crônica / Risk factors for chronic constipation

Este é um estudo complementar a um trabalho desenvolvido anteriormente, onde foi proposto um instrumento de coleta de dados para validar o diagnóstico de enfermagem de Risco para constipação. Assim,o objetivo desta pesquisa é o de validar clinicamente alguns fatores de risco deste diagnóstico.Participara do estudo 2 grupos de pacientes: 30 com constipação crônica e 30 não constipados, entrevistados no período de setembro de 1999 a fevereiro de 2000. foi feita a análise descritiva e aplicado o teste t e a regressão logística. os resultados mostraram que a média de ingestão de fibras em gramas , por semana, pelos pacientes constipados crônicos (84,9 g)ficou próximo à quantidade ingerida pelos não constipados (86,6 g).o mesmo ocorreu com a quantidade de líquidos em litro´s, ingeridos por semana , pelos pacientes constipados crônicos(6,3 l)e pelos não constipados(6,9 l).Nos dois grupos , a mesma quantidade de pacientes (66,7 %)tomava medicamentos constipantes.O fator idade avançada apresentou pequena tendência de diferença significativa nos pacientes constipados crônicos(0,096)enquanto que a ingestão de fibras e a ingestão de líquidos não apresentaram diferença significativa...