99 research outputs found

    Relation of exaggerated cytokine responses of CF airway epithelial cells to PAO1 adherence

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    In many model systems, cystic fibrosis (CF) phenotype airway epithelial cells in culture respond to P. aeruginosa with greater interleukin (IL)-8 and IL-6 secretion than matched controls. In order to test whether this excess inflammatory response results from the reported increased adherence of P. aeruginosa to the CF cells, we compared the inflammatory response of matched pairs of CF and non CF airway epithelial cell lines to the binding of GFP-PAO1, a strain of pseudomonas labeled with green fluorescent protein. There was no clear relation between GFP-PAO1 binding and cytokine production in response to PAO1. Treatment with exogenous aGM1 resulted in greater GFP-PAO1 binding to the normal phenotype compared to CF phenotype cells, but cytokine production remained greater from the CF cell lines. When cells were treated with neuraminidase, PAO1 adherence was equalized between CF and nonCF phenotype cell lines, but IL-8 production in response to inflammatory stimuli was still greater in CF phenotype cells. The polarized cell lines 16HBEo-Sense (normal phenotype) and Antisense (CF phenotype) cells were used to test the effect of disrupting tight junctions, which allows access of PAO1 to basolateral binding sites in both cell lines. IL-8 production increased from CF, but not normal, cells. These data indicate that increased bacterial binding to CF phenotype cells cannot by itself account for excess cytokine production in CF airway epithelial cells, encourage investigation of alternative hypotheses, and signal caution for therapeutic strategies proposed for CF that include disruption of tight junctions in the face of pseudomonas infection

    Potential mechanisms underlying the acute lung dysfunction and bacterial extrapulmonary dissemination during Burkholderia cenocepacia respiratory infection

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    <p>Abstract</p> <p>Background</p> <p><it>Burkholderia cenocepacia</it>, an opportunistic pathogen that causes lung infections in cystic fibrosis (CF) patients, is associated with rapid and usually fatal lung deterioration due to necrotizing pneumonia and sepsis, a condition known as cepacia syndrome. The key bacterial determinants associated with this poor clinical outcome in CF patients are not clear. In this study, the cytotoxicity and procoagulant activity of <it>B. cenocepacia </it>from the ET-12 lineage, that has been linked to the cepacia syndrome, and four clinical isolates recovered from CF patients with mild clinical courses were analysed in both <it>in vitro </it>and <it>in vivo </it>assays.</p> <p>Methods</p> <p><it>B. cenocepacia-</it>infected BEAS-2B epithelial respiratory cells were used to investigate the bacterial cytotoxicity assessed by the flow cytometric detection of cell staining with propidium iodide. Bacteria-induced procoagulant activity in cell cultures was assessed by a colorimetric assay and by the flow cytometric detection of tissue factor (TF)-bearing microparticles in cell culture supernatants. Bronchoalveolar lavage fluids (BALF) from intratracheally infected mice were assessed for bacterial proinflammatory and procoagulant activities as well as for bacterial cytotoxicity, by the detection of released lactate dehydrogenase.</p> <p>Results</p> <p>ET-12 was significantly more cytotoxic to cell cultures but clinical isolates Cl-2, Cl-3 and Cl-4 exhibited also a cytotoxic profile. ET-12 and CI-2 were similarly able to generate a TF-dependent procoagulant environment in cell culture supernatant and to enhance the release of TF-bearing microparticles from infected cells. In the <it>in vivo </it>assay, all bacterial isolates disseminated from the mice lungs, but Cl-2 and Cl-4 exhibited the highest rates of recovery from mice livers. Interestingly, Cl-2 and Cl-4, together with ET-12, exhibited the highest cytotoxicity. All bacteria were similarly capable of generating a procoagulant and inflammatory environment in animal lungs.</p> <p>Conclusion</p> <p><it>B. cenocepacia </it>were shown to exhibit cytotoxic and procoagulant activities potentially implicated in bacterial dissemination into the circulation and acute pulmonary decline detected in susceptible CF patients. Improved understanding of the mechanisms accounting for <it>B. cenocepacia</it>-induced clinical decline has the potential to indicate novel therapeutic strategies to be included in the care <it>B. cenocepacia</it>-infected patients.</p

    Differential activation of inflammatory pathways in A549 type II pneumocytes by Streptococcus pneumoniae strains with different adherence properties

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    BACKGROUND: Adherence of Streptococcus pneumoniae bacteria to lung cells is a first step in the progression from asymptomatic carriage to pneumonia. Adherence abilities vary widely among S. pneumoniae patient isolates. In this study, the binding properties of S. pneumoniae isolates and the effects of binding on activation of the Nuclear Factor-Kappa-B (NFκB) pathway and cytokine secretion by type II pneumocytes were measured. METHODS: Mechanisms of high- and low-binding S. pneumoniae adherence to A549 cells were investigated by blocking putative receptors on bacteria and host cells with antibody and by eluting choline-binding proteins off of bacterial surfaces. NFκB activation was measured by western blot and immunocytochemistry and cytokine secretion was detected by a protein array. RESULTS: This study shows that S. pneumoniae isolates from pneumonia patients (n = 298) can vary by as much as 1000-fold in their ability to bind to human lung epithelial cells. This difference resulted in differential activation of the NFκB pathway. High-, but not low-binding S. pneumoniae used Choline-binding protein A (CbpA) to bind to complement component C3 on epithelial cell surfaces. Interleukin-8 (IL-8) was the only cytokine secreted by cells treated with either low- or high-binding S. pneumoniae. CONCLUSION: These results indicate that S. pneumoniae clinical isolates are not homogeneous in their interaction with host epithelial cells. The differential activation of host cells by high- and low-binding S. pneumoniae strains could have implications for the treatment of pneumococcal pneumonia and for vaccine development

    Optimization problems of the thinning cycle

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    Problems of economic decisions in thinning

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    Evaluation of select cider apple (Malus domestica Borkh.) cultivars grown in Ontario. I. Horticultural attributes

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    Twenty-eight apple cultivars were selected for their potential for hard cider production in Ontario. An experiment was conducted to evaluate their horticultural potential in the province. After being planted in spring 2015, the trees were evaluated annually for their survival, tree height and spread, trunk growth, flowering dates, flower counts, fruit per tree, pre-harvest drop, crop load, fruit weight, fruit firmness, juicing extraction efficiency, and harvest dates. These horticultural attributes were sufficient to discriminate between cultivars. Additional exploratory analyses indicated a relationship between horticultural attributes and a cultivar’s origin, with British cider cultivars blooming the latest, American cider apples producing the most juice, and French cider cultivars having the highest pre-harvest fruit drop. Cultivars in this study that show promise for continued research in Ontario include Binet Rouge, Bramley’s Seedling, Breakwell, Bulmers Norman, Calville Blanc d’Hiver, Cline Russet, Cox Orange Pippin, Crimson Crisp, Dabinett, Enterprise, Esopus Spitzenberg, Golden Russet, GoldRush, Medaille d’Or, Porter’s Perfection, and Stoke Red.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Evaluation of select cider apple (Malus domestica Borkh.) cultivars grown in Ontario. II. Juice Attributes

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    Twenty-eight apple cultivars were selected for their potential for hard cider production in Ontario and their juice characteristics were measured in 2017 and 2018, beginning two years after planting in 2015. After being harvested and pressed, each juice sample underwent analyses to determine soluble solids concentration (SSC), titratable acidity (TA), pH, yeast assimilable nitrogen (YAN), and polyphenolic concentration. SSC ranged from 10.6 Brix in Brown’s Apple to 18.3 Brix in Ashmead’s Kernel. TA ranged from 31 as mg malic acid 100 mL-1 juice in Sweet Alford to 191 as mg malic acid 100 mL-1 juice in Bramley’s Seedling. The pH ranged from 2.88 in Breakwell to 4.76 in Sweet Alford. YAN concentration ranged from 60 mg YAN L-1 juice in Medaille d’Or to 256 mg YAN L-1 juice in Bulmers Norman. Polyphenols in juice ranged from 131 g gallic acid equivalents mL-1 juice in Tolman Sweet to 1042 g gallic acid equivalents mL-1 juice in Stoke Red. Firmness ranged from 6.3 kg in Yarlington Mill to 11.7 kg in GoldRush. The relationships between these variables were also analyzed, showing a connection between acidity and juicing efficiency as well as a relationship between polyphenol concentration and fruit weight. Exploratory analyses indicated that juice attributes can be used to distinguish between cultivars and their origins. Cider producers can use these data to determine what to expect in juice from these cultivars.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Management of biodiversity in the forests involved in the Natura 2000 network - conceptual outline

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    W pracy zajęto się opisem ekonomicznych warunków, w jakich idea ochrony bioróżnorodności leśnej może być skutecznie realizowana. Przede wszystkim skoncentrowano się na nowych formach regulacji gospodarki zasobami leśnymi mających na celu zachowanie i pomnażanie różnorodności biologicznej na terenach leśnych włączonych do sieci Natura 2000. W następnej kolejności dokonano analizy implikacji ekonomicznych związanych z wprowadzaniem różnego typu regulacji zarówno od strony metodologicznej, jak i dodatkowych kosztów, jakie obarczą gospodarstwo leśne w takich przypadkach. W tym celu wykorzystano znany w teorii zarządzania model Przełożony-Podwładny. Warto zaznaczyć, że w leśnictwie naszego kraju tego typu narzędzie analizy nie było dotychczas stosowane.The paper briefly describes the economic context in which the conservation of forest biodiversity is to take place. We focus on the new forms of regulation of forest resource management which has the goal of maintaining or improving biological diversity within the European Network Natura 2000. Next we analyze their implications for development on both the methodologies of management and the extra costs that forest owners and managers may have to bear. We base our study on the principal of joint production. We then concentrate on the possible application of a Principal- Agent model. We have to note that in Poland this type of tool has not been implemented yet
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