Molecular characterization of Cyclophilin (TcCyP19) in Trypanosoma cruzi populations susceptible and resistant to benznidazole

Cyclophilin (TcCyP19), a peptidyl-prolyl cis/trans isomerase, is a key molecule with diverse biological functions that include roles in molecular chaperoning, stress response, immune modulation, and signal transduction. In this respect, TcCyP19 could serve as a potential drug target in diseasecausing parasites. Previous studies employing proteomics techniques have shown that the TcCyP19 isoform was more abundant in a benznidazole (BZ)-resistant Trypanosoma cruzi population than in its susceptible counterpart. In this study, TcCyP19 has been characterized in BZ-susceptible and BZresistant T. cruzi populations. Phylogenetic analysis revealed a clear dichotomy between Cyphophilin A (CyPA) sequences from trypanosomatids and mammals. Sequencing analysis revealed that the amino acid sequences of TcCyP19 were identical among the T. cruzi samples analyzed. Southern blot analysis showed that TcCyP19 is a single-copy gene, located in chromosomal bands varying in size from 0.68 to 2.2 Mb, depending on the strain of T. cruzi. Northern blot and qPCR indicated that the levels of TcCyP19 mRNA were two-fold higher in drug-resistant T. cruzi populations than in their drugsusceptible counterparts. Similarly, as determined by two-dimensional gel electrophoresis immunoblot, the expression of TcCyP19 protein was increased to the same degree in BZ-resistant T. cruzi populations. No differences in TcCyP19 mRNA and protein expression levels were observed between the susceptible and the naturally resistant T. cruzi strains analyzed. Taken together, these data indicate that cyclophilin TcCyP19 expression is up-regulated at both transcriptional and translational levels in T. cruzi populations that were in vitro-induced and in vivo-selected for resistance to BZ.Fil: Rêgo, Juciane Vaz. Universidade Federal Do Piaui.; BrasilFil: Duarte, Ana Paula. Fundación Oswaldo Cruz; BrasilFil: Liarte, Daniel Barbosa. Universidade Federal Do Piaui.; BrasilFil: de Carvalho Sousa, Francirlene. Universidade Federal Do Piaui.; BrasilFil: Barreto, Humberto Medeiros. Universidade Federal Do Piaui.; BrasilFil: Bua, Jacqueline Elena. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romanha, Alvaro José. Fundación Oswaldo Cruz; BrasilFil: Rádis Baptista, Gandhi. Universidade Federal Do Piaui.; BrasilFil: Murta, Silvane Maria Fonseca. Universidade Federal Do Piaui.; Brasi

Implementação e avaliação de um instrumento de mediação e aprendizagem no âmbito de Aveiro Cidade Digital

Considerando os novos cenários em rede definidos por tecnologias e serviços da internet e da World Wide Web, propomos, utilizando media interactivo, mais concretamente, agentes multimedia on-line em rede com características multi-utilizador, desenvolver «módulos lúdicos» de aprendizagem, formação e consciencialização. O público-alvo são crianças dos 5 aos 10 anos e a actividade de comunicação e interacção deverá ser promovida no espaço «Actividade de Tempos Livres - ATL» dos jardins de infância inscritos nesta comunidade de trabalho, actualmente constituída por 15 instituições.Música, segurança rodoviária e ecologia serão os primeiros temas a ser trabalhados

A breakthrough on Amanita phalloides poisoning: an effective antidotal effect by polymyxin B

Amanita phalloides is responsible for more than 90 % of mushroom-related fatalities, and no effective antidote is available. a-Amanitin, the main toxin of A. phalloides, inhibits RNA polymerase II (RNAP II), causing hepatic and kidney failure. In silico studies included docking and molecular dynamics simulation coupled to molecular mechanics with generalized Born and surface area method energy decomposition on RNAP II. They were performed with a clinical drug that shares chemical similarities to a-amanitin, polymyxin B. The results show that polymyxin B potentially binds to RNAP II in the same interface of a-amanitin, preventing the toxin from binding to RNAP II. In vivo, the inhibition of the mRNA transcripts elicited by a-amanitin was efficiently reverted by polymyxin B in the kidneys. Moreover, polymyxin B significantly decreased the hepatic and renal a-amanitin-induced injury as seen by the histology and hepatic aminotransferases plasma data. In the survival assay, all animals exposed to a-amanitin died within 5 days, whereas 50 % survived up to 30 days when polymyxin B was administered 4, 8, and 12 h post-a-amanitin. Moreover, a single dose of polymyxin B administered concomitantly with a-amanitin was able to guarantee 100 % survival. Polymyxin B protects RNAP II from inactivation leading to an effective prevention of organ damage and increasing survival in a-amanitin-treated animals. The present use of clinically relevant concentrations of an already human-use-approved drug prompts the use of polymyxin B as an antidote for A. phalloides poisoning in humans.Juliana Garcia, Vera Marisa Costa, Ricardo Dinis-Oliveira and Ricardo Silvestre thank FCT-Foundation for Science and Technology-for their PhD grant (SFRH/BD/74979/2010), Post-doc grants (SFRH/BPD/63746/2009 and SFRH/BPD/110001/2015) and Investigator grants (IF/01147/2013) and (IF/00021/2014), respectively. This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) - project PTDC/DTPFTO/4973/2014 - and the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundacao para a Ciencia e Tecnologia) through project Pest-C/EQB/LA0006/2013

Urbs e civitas: a formação dos espaços e territórios urbanos nas minas setecentistas

O presente artigo procura situar a evolução das abordagens acerca da cidade colonial mineira dentro da perspectiva mais ampla dos estudos sobre o urbanismo colonial português. A análise privilegia os trabalhos que, em vez de se aterem aos aspectos ligados à estética urbana, procuraram relacioná-los às questões fundiárias e à constituição das redes e hierarquias urbanas.This article seeks to situate the evolution of approaches to the study of the colonial towns of Minas Gerais placing them in the broader perspective of studies on the Portuguese colonial urbanism. Instead of restricting our approach to questions of urban aesthetics, the analysis focuses on the works that tried to relate these questions to aspects of land ownership and to the establishment of networks and urban hierarchies