In this work we present a computational study of the kinetoplast genome, modelled as a large number of semiflexible unknotted loops, which are allowed to link with each other. As the DNA density increases, the systems shows a percolation transition between a gas of unlinked rings and a network of linked loops which spans the whole system. Close to the percolation transition, we find that the me...

Salivarian trypanosomes are the causative agents of several diseases of major social and economic impact. The most infamous parasites of this group are the African subspecies of the Trypanosoma brucei group, which cause sleeping sickness in humans and nagana in cattle. In terms of geographical distribution, however, Trypanosoma equiperdum and Trypanosoma evansi have been far more successful, ca...

Cutaneous leishmaniasis (CL), a public health problem in Tunisia, is associated to three species: Leishmania (L.) infantum, L. major and L. killicki. Accurate and sensitive procedures for the diagnostic of Leishmania infection and for species identification are required to enable adequate treatment and appropriate control measures. Several PCR-methods are applied for the diagnosis and the ident...

The positivities of two methods for the diagnosis of localised cutaneous leishmaniasis (CL) were estimated in 280 patients enrolled in a clinical trial. The trial was conducted in an endemic area of Leishmania (Viannia) braziliensis and trial participants were patients with skin ulcers and positive leishmanin skin tests. Patients underwent aspirative skin punctures of the ulcerated lesions and ...

BACKGROUND The determinants of parasite persistence or elimination after treatment and clinical resolution of cutaneous leishmaniasis (CL) are unknown. We investigated clinical and parasitological parameters associated with the presence and viability of Leishmania after treatment and resolution of CL caused by L. Viannia. METHODS Seventy patients who were treated with meglumine antimoniate (n...

Leishmaniasis comprises a spectrum of parasitic diseases caused by protozoans of the genus Leishmania. Molecular tools have been widely employed for the detection of Leishmania due to its high sensitivity and specificity. However, the analytical performance of molecular platforms as PCR and real time PCR (qPCR) including a wide variety of molecular markers has never been evaluated. Herein, the ...

A 6 M guanidine-HCl/0.2 M EDTA solution was used to lyse and store whole blood specimens. DNA stored in guanidine-EDTA-blood (GEB) lysate was found to be undegraded after incubation at 37 degrees C for 1 month, suggesting that this represents an appropriate reagent for transport of blood samples from the field to a laboratory for analysis. Trypanosoma cruzi kinetoplast DNA in GEB lysate can be ...

Replication of the kinetoplast DNA (kDNA) minicircle of trypanosomatids initiates at a conserved 12-nt sequence, 5'-GGGGTTGGTGTA-3', termed the universal minicircle sequence (UMS). A sequence-specific single-stranded DNA-binding protein from Crithidia fasciculata binds the heavy strand of the 12-mer UMS. Whereas this UMS-binding protein (UMSBP) does not bind a duplex UMS dodecamer, it binds the...

Several different models of Trypanosoma cruzi evolution have been proposed. These models suggest that scarce events of genetic exchange occurred during the evolutionary history of this parasite. In addition, the debate has focused on the existence of one or two hybridisation events during the evolution of T. cruzi lineages. Here, we reviewed the literature and analysed available sequence data t...

OBJECTIVE To investigate the effects of β-Elemene (β-ELE) on the proliferation, apoptosis, and topoisomerase I (TOPO I) and topoisomerase IIα (TOPO IIα) expression and activity of human hepatocarcinoma HepG-2 cells. METHODS After treatment with β-ELE, morphological alterations of HepG-2 cells were observed under an inverted microscope. Cell proliferation was assessed using an MTT assay, cell ...