163 research outputs found

    Real-time PCR Method for the Quantification of Burkholderia Cepacia Complex Attached to Lung Epithelial Cells and Inhibitionn of that Attachment

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    To develop a rapid method to quantify the attachment of the cystic fibrosis pathogen, Burkholderia multivorans, to lung epithelial cells (16HBE14o(-)) using real-time PCR with a view to monitoring potential inhibition of lung cell attachment. Mammalian and bacterial DNA were purified from bacteria attached to lung epithelial cells. The relative amount of bacteria attached was determined by amplification of the recA gene relative to the human GAPDH gene, in the presence of SYBR Green. The method was thoroughly validated and shown to correlate well with traditional plating techniques. Inhibition of bacterial attachment with simple sugars was then evaluated by real-time PCR. Of the sugars examined, pre-incubation of B. multivorans with lactose, mannose and xylitol all decreased bacterial adherence to 16HBE14o(-) cells, while glucose and galactose had no significant effect. Pre-incubation with lactose had the greatest effect, resulting in reduced adhesion to 35% of untreated controls. This method can be used to quickly and effectively screen novel agents with higher affinities for bacterial adhesins. This method will enable the rapid development of novel agents to inhibit colonization by this pathogen from the environment

    Virulence of an emerging respiratory pathogen, genus Pandoraea, in vivo and its interactions with lung epithelial cells

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    Pandoraea species have emerged as opportunistic pathogens among cystic fibrosis (CF) and non-CF patients. Pandoraea pulmonicola is the predominant Pandoraea species among Irish CF patients. The objective of this study was to investigate the pathogenicity and potential mechanisms of virulence of Irish P. pulmonicola isolates and strains from other Pandoraea species. Three patients from whom the P. pulmonicola isolates were isolated have since died. The in vivo virulence of these and other Pandoraea strains was examined by determining the ability to kill Galleria mellonella larvae. The P. pulmonicola strains generally were the most virulent of the species tested, with three showing a comparable or greater level of virulence in vivo relative to another CF pathogen, Burkholderia cenocepacia, whilst strains from two other species, Pandoraea apista and Pandoraea pnomenusa, were considerably less virulent. For all Pandoraea species, whole cells were required for larval killing, as cell-free supernatants had little effect on larval survival. Overall, invasive Pandoraea strains showed comparable invasion of two independent lung epithelial cell lines, irrespective of whether they had a CF phenotype. Pandoraea strains were also capable of translocation across polarized lung epithelial cell monolayers. Although protease secretion was a common characteristic across the genus, it is unlikely to be involved in pathogenesis. In conclusion, whilst multiple mechanisms of pathogenicity may exist across the genus Pandoraea, it appears that lung cell invasion and translocation contribute to the virulence of P. pulmonicola strains

    Evaluation of In Vitro Virulence Characteristics of the Genus Pandoraea in Lung Epithelial Cells

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    Pandoraea species are emerging opportunistic pathogens capable of causing chronic lung infections in cystic fibrosis patients. This study examined the interactions of 17 Pandoraea isolates from the five identified species (Pandoraea apista, Pandoraea norimbergensis, Pandoraea pulmonicula, Pandoraea sputorum and Pandoraea pnomenusa) plus two Pandoraea genomospecies isolates with lung epithelial cells and their ability to form biofilms in vitro. Only three isolates showed an ability to invade A549 lung epithelial cells, and only one isolate was able to form biofilms. In contrast, all isolates triggered a pronounced pro-inflammatory response, with elevation of both interleukin (IL)-6 (two- to 19-fold) and IL-8 (10- to 50-fold) above that observed for a control strain of Escherichia coli. This property is likely to be a major factor in the pathogenesis of the genus

    Acidosis Maintains the Function of Brain Mitochondria in Hypoxia-Tolerant Triplefin Fish: A Strategy to Survive Acute Hypoxic Exposure?

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    The vertebrate brain is generally very sensitive to acidosis, so a hypoxia-induced decrease in pH is likely to have an effect on brain mitochondria (mt). Mitochondrial respiration (JO2) is required to generate an electrical gradient (ΔΨm) and a pH gradient to power ATP synthesis, yet the impact of pH modulation on brain mt function remains largely unexplored. As intertidal fishes within rock pools routinely experience hypoxia and reoxygenation, they would most likely experience changes in cellular pH. We hence compared four New Zealand triplefin fish species ranging from intertidal hypoxia-tolerant species (HTS) to subtidal hypoxia-sensitive species (HSS). We predicted that HTS would tolerate acidosis better than HSS in terms of sustaining mt structure and function. Using respirometers coupled to fluorimeters and pH electrodes, we titrated lactic-acid to decrease the pH of the media, and simultaneously recorded JO2, ΔΨm, and H+ buffering capacities within permeabilized brain and swelling of mt isolated from non-permeabilized brains. We then measured ATP synthesis rates in the most HTS (Bellapiscus medius) and the HSS (Forsterygion varium) at pH 7.25 and 6.65. Mitochondria from HTS brain did have greater H+ buffering capacities than HSS mt (∼10 mU pH.mgprotein-1). HTS mt swelled by 40% when exposed to a decrease of 1.5 pH units, and JO2 was depressed by up to 15% in HTS. However, HTS were able to maintain ΔΨm near -120 mV. Estimates of work, in terms of charges moved across the mt inner-membrane, suggested that with acidosis, HTS mt may in part harness extra-mt H+ to maintain ΔΨm, and could therefore support ATP production. This was confirmed with elevated ATP synthesis rates and enhanced P:O ratios at pH 6.65 relative to pH 7.25. In contrast, mt volumes and ΔΨm decreased downward pH 6.9 in HSS mt and paradoxically, JO2 increased (∼25%) but ATP synthesis and P:O ratios were depressed at pH 6.65. This indicates a loss of coupling in the HSS with acidosis. Overall, the mt of these intertidal fish have adaptations that enhance ATP synthesis efficiency under acidic conditions such as those that occur in hypoxic or reoxygenated brain

    Financial crisis and North-South gap within the main media groups in the EU

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    La crisis y los ajustes económicos en los grandes grupos de medios comunicación de la Unión Europea han incrementado la brecha Norte-Sur en cuanto a solidez financiera, competitividad y capitalización, a favor de los modelos centroeuropeo y anglosajón. Los resultados financieros de los 93 mayores grupos y empresas del sector en la UE evidencian no sólo los efectos perniciosos de la financiarización y la coyuntura económica, sino también el incremento de las divergencias regionales en la UE-28. Los países mediterráneos, con los peores resultados, son los más expuestos a estos peligros y muestran los escasos avances en la convergencia del sector mediático europeo en cuanto a gestión económica y solidez para cumplir sus cometidos sociales. La crisis ha reforzado la posición de los grupos mediáticos del Norte frente a un debilitado Sur, que ya partía de una mayor dependencia por su mayor exposición a intereses partidistas. La difusión diaria de prensa en la UE bajó de 115,33 millones de ejemplares distribuidos en 2008 a 82,54 millones en 2012, un 27,73% menos. El 64,5% de los grandes medios cotizados en la UE-28 se concentra en cinco países. El 52,7% de los medios cuenta con participaciones significativas de instituciones financierasThe financial crisis and the economic adjustments within the most important media groups of the European Union (EU) have enlarged the North-South gap regarding financial strength, competitiveness and capitalisation, favouring Center European and UK patterns. The financial results of the 93 biggest media groups and enterprises in the EU provide evidence of not only the pernicious effects of financialization, but also the increase of regional divergences within the EU-28. The Mediterranean countries, which have got the worst results in all of the indicators analysed, are the most exposed to those dangers and confirm the poor advances of the media sector regarding convergence of management and economic solidity, at the expense of their capability to fulfil their social aims. The crisis has strengthened the position of the media groups in the North in front of the weakened South, that already had a greater dependence by its greater exposure to partisan interests. The daily circulation of press in the EU fell from 115.33 million copies distributed in 2008 to 82.54 in 2012, 27.73% less. 64.5% of the major media listed in the EU-28 is concentrated in five countries. 52.7% of the media has significant holdings in financial institutionsS

    The construction of viewpoint aspect: the imperfective revisited

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    This paper argues for a constructionist approach to viewpoint Aspect by exploring the idea that it does not exert any altering force on the situation-aspect properties of predicates. The proposal is developed by analyzing the syntax and semantics of the imperfective, which has been attributed a coercer role in the literature as a de-telicizer and de-stativizer in the progressive, and as a de-eventivizer in the so-called ability (or attitudinal) and habitual readings. This paper proposes a unified semantics for the imperfective, preserving the properties of eventualities throughout the derivation. The paper argues that the semantics of viewpoint aspect is encoded in a series of functional heads containing interval-ordering predicates and quantifiers. This richer structure allows us to account for a greater amount of phenomena, such as the perfective nature of the individual instantiations of the event within a habitual construction or the nonculminating reading of perfective accomplishments in Spanish. This paper hypothesizes that nonculminating accomplishments have an underlying structure corresponding to the perfective progressive. As a consequence, the progressive becomes disentangled from imperfectivity and is given a novel analysis. The proposed syntax is argued to have a corresponding explicit morphology in languages such as Spanish and a nondifferentiating one in languages such as English; however, the syntax-semantics underlying both of these languages is argued to be the same

    A randomized, open-label, multicentre, phase 2/3 study to evaluate the safety and efficacy of lumiliximab in combination with fludarabine, cyclophosphamide and rituximab versus fludarabine, cyclophosphamide and rituximab alone in subjects with relapsed chronic lymphocytic leukaemia

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