Theoretical study of ArcB and its dimerization, interaction with anaerobic metabolites, and activation of ArcA.

The complex metabolism of has been extensively studied, including its response to oxygen availability. The ArcA/B two-component system (TCS) is the key regulator for the transition between these two environmental conditions and has been thoroughly characterized using genetic and biochemical approaches. Still, to date, limited structural data is available.

Trichomonas vaginalis triggers neutrophil extracellular traps reducing parasite integrity and growth.

Trichomoniasis-caused by the parasite Trichomonas vaginalis-is associated with a high inflammatory process that may contribute to the risk of suffering from other medical complications. Our study focused on the in vitro interaction of T. vaginalis with human neutrophils because these are the most abundant cells implicated in the characteristic inflammatory process of trichomoniasis.

Immune cell arrival kinetics to peritoneum and role during murine-experimental trichomoniasis.

Trichomonas vaginalis causes trichomoniasis, an inflammatory process related to an increased rate of HIV transmission. In order to study T. vaginalis infection response in a microorganism-free environment, an infection model was established providing a host–parasite interaction system useful to study the interplay between immune cells and the parasite.

Reduced viability in mice pretreated with parasite DNA.

Trichomonas vaginalis is an extracellular parasite that colonizes the human urogenital tract leading to trichomoniasis, the most common sexually-transmitted non-viral disease worldwide. The immune response plays a critical role in the host defense against this parasite. Trichomonas' DNA contains unmethylated CpG motifs (CpGDNA) that in other microorganisms act as modulators of the immune response.

Trichomonas vaginalis exosome-like vesicles modify the cytokine profile and reduce inflammation in parasite-infected mice.

Trichomonas vaginalis (Tv) is a flagellated parasite commonly spread through sexual transmission. This protozoan initiates a severe inflammatory process, inducing nitric oxide, interleukin-6 (IL-6), IL-8, IL-10, IL-17 and IL-22 production by host immune cells. The parasites elicit these responses by releasing surface lipophosphoglycan, small extracellular vesicles (exosomes) and other factors.

The component leaching from decellularized pericardial bioscaffolds and its implication in the macrophage response.

The extracellular matrix molecules remaining in bioscaffolds derived from decellularized xenogeneic tissues appear to be important for inducing cell functions conducting tissue regeneration. Here, we studied whether decellularization methods, that is, detergent Triton X-100 (TX) alone and TX combined with reversible alkaline swelling (STX), applied to bovine pericardial tissue, could affect the bioscaffold components. The in vitro macrophage response, subdermal biodegradation, and cell infiltration were also studied.

A PCR procedure for the detection of Giardia intestinalis cysts and Escherichia coli in lettuce.

Giardia intestinalis is a pathogen associated with foodborne outbreaks and Escherichia coli is commonly used as a marker of faecal contamination. Implementation of routine identification methods of G. intestinalis is difficult for the analysis of vegetables and the microbiological detection of E.

Identification of the transcription factor Znc1p, which regulates the yeast-to-hypha transition in the dimorphic yeast Yarrowia lipolytica.

The dimorphic yeast Yarrowia lipolytica is used as a model to study fungal differentiation because it grows as yeast-like cells or forms hyphal cells in response to changes in environmental conditions. Here, we report the isolation and characterization of a gene, ZNC1, involved in the dimorphic transition in Y. lipolytica.

Indirect determination of nitric oxide production by reduction of nitrate with a freeze-thawing-resistant nitrate reductase from Escherichia coli MC1061.

Preparation of a nitrate reductase lysate of Escherichia coli MC1061 to measure nitrate and nitrite in biologic fluids is described. To obtain the crude bacterial lysate containing nitrate reductase activity, E. coli MC1061 was subjected to 16-20 freeze-thawing cycles, from -70 to 60 degrees C, until nitrite reductase activity was < or = 25%.

Iron chelators modulate the fusogenic properties of Salmonella-containing phagosomes.

In macrophages, the divalent cations transporter Nramp1 is recruited from the lysosomal compartment to the membrane of phagosomes formed in these cells. Nramp1 mutations cause susceptibility to infection with intracellular pathogens such as Salmonella and Mycobacterium. Intracellular survival of Salmonella involves segregation in an endomembrane compartment (Salmonella-containing vacuole, SCV) that remains negative for the mannose-6-phosphate receptor (M6PR) and that is inaccessible to the endocytic pathway.

Role of 3-phosphoinositides in the maturation of Salmonella-containing vacuoles within host cells.

Salmonella typhimurium invades mammalian cells and replicates within a vacuole that protects it from the host's microbicidal weapons. The Salmonella-containing vacuole (SCV) undergoes a remodelling akin to that of the host cell's endocytic pathway, but SCV progression is arrested prior to fusion with lysosomes. We studied the role of phosphatidylinositol 3-kinase (PI3-K) in SCV maturation within HeLa cells.

Nramp1 modifies the fusion of Salmonella typhimurium-containing vacuoles with cellular endomembranes in macrophages.

Salmonella survive and replicate within mammalian cells by becoming secluded within specialized membrane-bound vacuoles inaccessible to the host defense mechanisms. Delayed acidification of the vacuole and its incomplete fusion with lysosomes have been implicated in intracellular Salmonella survival. Nramp1 confers to macrophages resistance to a variety of intracellular pathogens, including Salmonella, but its precise mode of action is not understood.

The GTP-binding protein RhoA localizes to the cortical granules of Strongylocentrotus purpuratas sea urchin egg and is secreted during fertilization.

The sea urchin egg has thousands of secretory vesicles known as cortical granules. Upon fertilization, these vesicles undergo a Ca2+-dependent exocytosis. G-protein-linked mechanisms may take place during the egg activation.

Multiple GTP-binding proteins in sea urchin sperm: Evidence for Gs and small G-proteins.

Sea urchin sperm plasma membranes isolated from heads and flagella were used to examine the presence of Gs (stimulatory guanine nucleotide-binding regulatory protein) and small G-proteins. Flagellar plasma membranes incubated with [ P]NAD and cholera toxin (CTX) displayed radiolabeling in a protein of 48 kDa, which was reactive by immunoblotting with a specific antibody against mammalian Gs. CTX-catalyzed [ P]ADP-ribosylation in conjunction with immunoprecipitation with anti-Gs, followed by electrophoresis and autoradiography, revealed one band of 48 kDa.