Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions.

Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM) of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes.

Inhibitory activity of root canal irrigants against Candida albicans, Enterococcus faecalis and Staphylococcus aureus.

The present study evaluated the antimicrobial activity of three root canal irrigants against Enterococcus faecalis, Candida albicans, and Staphylococcus aureus. These microorganisms were incubated in the presence of citric acid (6 and 10%), EDTA (17%), and NaOCl (0.5, 1.

Effects of platelet-activating factor on the interaction of Trypanosoma cruzi with Rhodnius prolixus.

We investigated the effects of platelet-activating factor (PAF) on the interaction of Trypanosoma cruzi with Rhodnius prolixus. The parasites (epimastigotes) were treated with PAF and/or WEB 2086 (PAF antagonist) for 1 h prior to the interaction experiments. PAF stimulated both in vivo and ex vivo interactions between T.

Low-intensity pulsed ultrasound-dependent osteoblast proliferation occurs by via activation of the P2Y receptor: role of the P2Y1 receptor.

Low-intensity pulsed ultrasound (LIPUS) is commonly used in the treatment of fractures and nonunion-promoting acceleration of healing fractures. In this report, we investigated the implication of the P2 receptors in osteoblast proliferation induced with LIPUS treatment. We observed that ADP, ATP, UTP, and UDP promote osteoblast increase and an increase of intracellular Ca(2+), through activation of P2Y receptors.

Group B Streptococcus induces tyrosine phosphorylation of annexin V and glutathione S-transferase in human umbilical vein endothelial cells.

Group B Streptococcus (GBS), a human pathogen that causes infection and invasive diseases in newborns, pregnant women and immunocompromised adults, has been shown to invade human umbilical vein endothelial cells (HUVECs). The objective of this study was to investigate the molecular mechanisms underlying GBS-HUVEC interaction, focusing specifically on the responsiveness of host protein tyrosine kinase (PTK). We found that GBS serotypes III and V induced actin reorganization and formation of stress fibers into HUVECs.

Acanthamoeba interaction with extracellular matrix glycoproteins: biological and biochemical characterization and role in cytotoxicity and invasiveness.

Acanthamoeba are free-living amoebae that are dispersed in most environments. Occasionally, Acanthamoeba cause serious human infections, such as keratitis and encephalitis. During the infection process, amoebic adhesion to, and degradation of, host cells and their extracellular matrix (ECM) appear to be important requirements.

The redox potential interferes with the expression of laminin binding molecules in Bacteroides fragilis.

The Bacteroides fragilis ATCC strain was grown in a synthetic media with contrasting redox potential (Eh) levels [reduced (-60 mV) or oxidised (+100 mV)] and their adhesion capacity to extracellular matrix components was evaluated. The strain was capable of adhering to laminin, fibronectin, fibronectin + heparan sulphate and heparan sulphate. A stronger adherence to laminin after growing the strain under oxidising conditions was verified.

Application of two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for proteomic analysis of the sexually transmitted parasite Trichomonas vaginalis.

Trichomonas vaginalis is a sexually transmitted protozoan parasite that infects the human urogenital tract causing trichomoniasis, a worldwide disease. In this work, a fresh clinical isolate of T. vaginalis was used for study of the protein expression in this species.

A further proteomic study on the effect of iron in the human pathogen Trichomonas vaginalis.

Iron is an essential element to support the growth and survival of Trichomonas vaginalis. It plays a critical role in the host-parasite interaction, and modulates the expression of virulence factors in this protozoan. In this work, parasites grown in iron-rich and iron-depleted media were analyzed by (i) light and scanning electron microscopy and (ii) 2-DE and MS.

The interaction between Acanthamoeba polyphaga and human osteoblastic cells in vitro.

Acanthamoeba spp. contains a group of free-living amoebae widespread in nature. These microorganisms may cause several diseases in humans including osteomyelitis.

Modulation of intercellular communication in macrophages: possible interactions between GAP junctions and P2 receptors.

Gap junctions are connexin-formed channels that play an important role in intercellular communication in most cell types. In the immune system, specifically in macrophages, the expression of connexins and the establishment of functional gap junctions are still controversial issues. Macrophages express P2X(7) receptors that, once activated by the binding of extracellular ATP, lead to the opening of transmembrane pores permeable to molecules of up to 900 Da.

Sialic acid residues on astrocytes regulate neuritogenesis by controlling the assembly of laminin matrices.

In the developing nervous system migrating neurons and growing axons are guided by diffusible and/or substrate-bound cues, such as extracellular matrix-associated laminin. In a previous work we demonstrated that laminin molecules could self-assemble in two different manners, giving rise to matrices that could favor either neuritogenesis or proliferation of cortical precursor cells. We investigated whether the ability of astrocytes to promote neuritogenesis of co-cultivated neurons was modulated by the assembling mode of the laminin matrix secreted by them.

Tritrichomonas foetus: the role played by iron during parasite interaction with epithelial cells.

The aim of this work was to investigate the role played by iron during interaction of Tritrichomonas foetus with cultured epithelial cells. We have observed that the growth rate of T. foetus is influenced by the amount of iron available into culture medium.

Anionogenic groups and surface sialoglycoconjugate structures of yeast forms of the human pathogen Paracoccidioides brasiliensis.

The surface anionogenic groups and sialoglycoconjugate structures of Paracoccidioides brasiliensis yeast forms were analysed by cell microelectrophoresis, binding assays with lectins and viral particles, ultrastructural cytochemistry, enzymic digestion and flow cytofluorimetry. P. brasiliensis yeast forms, particularly the budding primordia, reacted strongly with cationized ferritin.