Attachment of the prenyl groups farnesyl and geranylgeranyl to specific eukaryotic cell proteins by protein prenyltransferases is required for the functioning of a number of cellular processes including signal transduction. In this study it was found that previously reported inhibitors of mammalian protein farnesyltransferase (PFT) [those that mimic the substrate farnesyl pyrophosphate and thos...

In spite of the growing knowledge obtained about immune control of Trypanosoma cruzi infection, the mechanisms responsible for the variable clinico-pathological expression of Chagas disease remain unknown. In a twist from previous concepts, recent studies indicated that tissue parasitism is a pre-requisite for the development of chronic myocarditis. This fundamental concept, together with the r...

A natural case of co-infection by Leishmania and Trypanosoma is reported in a dog (Canis familiaris) in south- western state of Mato Grosso do Sul, Brazil. Both amastigote and trypomastigote forms were observed after Giemsa staining of cytological preparations of the dog's bone marrow aspirate. No parasite was detected using medium culture inoculation of the sample. DNA obtained from the bone m...

The acute phase of Trypanosoma cruzi infection is associated with a strong inflammatory reaction in the heart characterised by a massive infiltration of immune cells that is dependent on the T. cruzi strain and the host response. 15d-PGJ(2) belongs to a new class of anti-inflammatory compounds with possible clinical applications. We evaluated the effects of 15d-PGJ(2) administered during the ac...

Leishmania (Leishmania) amazonensis exhibits peculiarities in its interactions with hosts. Because amastigotes are the primary form associated with the progression of infection, we studied the effect of insulin-like growth factor (IGF)-I on interactions between L. (L.) amazonensis amastigotes and macrophages. Upon stimulation of infected macrophages with IGF-I, we observed decreased nitric oxid...

Widespread antimonial resistance in anthroponotic visceral leishmaniasis (VL) makes it critical to monitor the susceptibility of prevailing field isolates to upcoming antileishmanials in order to frame the right treatment policies to protect these drugs against development of resistance. We aimed to generate the baseline data on natural in vitro susceptibility to paromomycin and sitamaquine in ...

BACKGROUND The present study aims to identify antigens in protein extracts of promastigote and amastigote-like Leishmania (Leishmania) chagasi syn. L. (L.) infantum recognized by antibodies present in the sera of dogs with asymptomatic and symptomatic visceral leishmaniasis (VL). METHODOLOGY/PRINCIPAL FINDINGS Proteins recognized by sera samples were separated by two-dimensional electrophores...

In this study we have examined certain aspects of the process of cell invasion and parasitophorous vacuole escape by metacyclic trypomastigotes and extracellular amastigote forms of Trypanosoma cruzi (G strain). Using Vero (and HeLa) cells as targets, we detected differences in the kinetics of vacuole escape by the two forms. Alcalinization of intercellular pH influenced both invasion as well a...

CONTEXT Natural products and their compounds are some of the most interesting sources of new drugs. Reviews have reported various pharmacological properties such as antimicrobial effects of Zataria multiflora Boiss (Lamiaceae). OBJECTIVE The present study investigates the chemical composition of Z. multiflora essential oil and evaluates its cytotoxic effects and anti-leishmanial activities ag...

Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and affects approximately 10 million people in endemic areas of Mexico and Central and South America. Currently available chemotherapies are limited to two compounds: Nifurtimox and Benznidazole. Both drugs reduce the symptoms of the disease and mortality among infected individuals when used during the acute phase, but their ...