Encontrados 11 documentos, a visualizar página 1 de 2
FGF signaling pathway in the developing chick lung : expression and inhibition ...
Moura, Rute S.; Borges, José P. Coutinho; Pacheco, A. P.; Mota, Paulo O. da; Pinto, Jorge CorreiaFibroblast growth factors (FGF) are essential key players during embryonic development. Through their specific cognate receptors (FGFR) they activate intracellular cascades, finely regulated by modulators such as Sprouty. Several FGF ligands (FGF1, 2, 7, 9, 10 and 18) signaling through the four known FGFRs, have been implicated in lung morphogenesis. Although much is known about mammalian lung, so far, the avia...
Drinking water biofilm assessment of total and culturable bacteria under differ...
Simões, Lúcia C.; Azevedo, N. F.; Pacheco, A. P.; Keevil, C. W.; Vieira, M. J.Monitoring of biofilms subjected to different operating conditions was performed using a flow cell system. The system was fed by chlorine-free tap water, with and without added nutrients (0.5 mg l ˉ¹carbon, 0.1 mg l ˉ¹nitrogen and 0.01 mg lˉ¹ phosphorus), and biofilms were grown on polyvinyl chloride (PVC) and stainless steel (SS) coupons, both in laminar and turbulent flow. The parameters analysed were cultura...
Adhesion of water stressed Helicobacter pylori to abiotic surfaces
Azevedo, N. F.; Pacheco, A. P.; Keevil, C. W.; Vieira, M. J.Aim: The main aim of this work was to study and compare the adhesion of water exposed Helicobacter pylori to six different substrata and correlate any changes in morphology, physiology, ability to form aggregates and cultivability when in the planktonic or in the sessile phase. Methods and Results: The number of total cells adhered for different water exposure times and modifications in the cell shape were eva...
Factors affecting the adhesion of water-stressed Helicobacter pylori to plumbin...
Azevedo, N. F.; Pacheco, A. P.; Pinto, A. R.; Keevil, C. W.; Vieira, M. J.Resumo apresentado no "XVIIIth International Workshop on Gastrointestinal Pathology and Helicobacter", Copenhagen, Denmark, 2005. ; The most important route(s) of transmission for Helicobacter pylori among the human population has yet to be identified, but water and associated biofilms have been considered as potential environmental reservoirs in several studies. Although molecular techniques have identified H...
The role of biofilms in the transmission of Helicobacter pylori through drinkin...
Azevedo, N. F.; Pinto, A. R.; Reis, N.; Pacheco, A. P.; Keevil, C. W.; Vieira, M. J.Helicobacter pylori has a major role in promoting risk of peptic ulcer disease and non-cardia adenocarcinoma of the stomach and is present in more than 80% of the Portuguese population. The route of transmission of H. pylori to humans remains a controversial question, but it has been suggested that the bacterium may survive in water supplies by becoming associated with autochthonous microorganisms present in bi...
Nutrient shock and incubation atmosphere influence recovery of culturable helic...
Azevedo, N. F.; Pacheco, A. P.; Keevil, C. W.; Vieira, M. J.Three different media—Columbia agar, Wilkins-Chalgren agar, and Helicobacter pylori special peptone agar—were prepared in a diluted version and compared to the standard medium formulation in order to study a possible nutrient shock effect observed when recovering H. pylori from water by counting the number of CFU. This same parameter was subsequently used to evaluate the influence of the incubation atmosphere b...
Study of surface characteristics of water-exposed Helicobacter pylori and plumb...
Azevedo, N. F.; Pacheco, A. P.; Pinto, A. R.; Keevil, C. W.; Vieira, M. J.Adhesion of Helicobacter pylori to six materials of different hydrophobicity and commonly used in drinking water distribution systems was investigated using epifluorescence microscopy. The values obtained were subsequently compared with theoretical adhesion values, based on surface tension components and hydrophobicity, calculated through contact angle measurements. Bacteria were found to have a hydrophobic sur...
Monitoring cell detachment by surfactants in a parallel plate flow chamber
Azeredo, Joana; Pacheco, A. P.; Lopes, I.; Oliveira, Rosário; Vieira, M. J.The efficacy of the surfactants SDS and CTAB in detaching P. fluorescens from glass surface was evaluated in a parallel plate flow chamber. This device enables “in situ” determinations of cells detachment following the application of surfactants under well controlled hydrodynamic conditions. The results showed that SDS was able to remove almost all adhering bacteria in a short period of time, whereas CTAB did n...
Monitoring cell detachment by surfactants in a parallel plate flow chamber
Azeredo, Joana; Pacheco, A. P.; Lopes, I.; Oliveira, Rosário; Vieira, M. J.The efficacy of the surfactants SDS and CTAB in detaching P. fluorescens from glass surface was evaluated in a parallel plate flow chamber. This device enables “in situ” determinations of cells detachment following the application of surfactants under well controlled hydrodynamic conditions. The results showed that SDS was able to remove almost all adhering bacteria in a short period of time, whereas CTAB did n...
The effect of clay particles on the activity of suspended autotrophic nitrifyin...
Vieira, M. J.; Pacheco, A. P.; Espírito Santo, I. A. C. P.; Melo, L. F.Clay minerals have some properties, namely a high surface area and the ability of ion exchange that may exert some effects on microbial systems. It is often difficult to know the way the clay is exerting its influence and whether its presence improves a given metabolic process The present work concerns the study of the effect of the addition of Powdered kaolin to autotrophic nitrification systems, and includes ...
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