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Search Results: 1 - 10 of 4575 matches for " Bathoorn Erik "
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Airways inflammation and treatment during acute exacerbations of COPD
Erik Bathoorn,Huib Kerstjens,Dirkje Postma,Wim Timens
International Journal of COPD , 2008,
Abstract: Erik Bathoorn1, Huib Kerstjens1, Dirkje Postma1, Wim Timens2, William MacNee31Groningen Research Institute for Asthma and COPD (GRIAC), Department of Pulmonology, 2Department of Pathology, University Medical Center Groningen, University of Groningen, the Netherlands; 3Edinburgh Lung and the Environment Group Initiative/Colt Research Laboratories, Medical School, University of Edinburgh, Edinburgh, Scotland, United KingdomIntroduction: Inflammation is a core feature of acute chronic obstructive pulmonary disease (COPD) exacerbations. It is important to focus on inflammation since it gives insight into the pathological changes causing an exacerbation, thereby possibly providing directions for future therapies which modify inflammation.Objectives: To provide a cell-by-cell overview of the inflammatory processes during COPD exacerbations. To evaluate cell activation, and cytokine production, cellular interactions, damaging effects of inflammatory mediators to tissue, and the relation to symptoms at the onset of COPD exacerbations. To speculate on future therapeutic options to modify inflammation during COPD exacerbations.Results: During COPD exacerbations, there is increased airway wall inflammation, with pathophysiological influx of eosinophils, neutrophils, and lymphocytes. Although links have been suggested between the increase in eosinophils and lymphocytes and a viral etiology of the exacerbation, and between the increase in neutrophils and a bacterial aetiology, these increases in both inflammatory cell types are not limited to the respective aetiologies and the underlying mechanisms remain elusive.Conclusion: Further research is required to fully understand the inflammatory mechanisms in the onset and development of COPD exacerbations. This might make inflammatory pathway-specific intervention possible, resulting in a more effective treatment of COPD exacerbations with fewer side effects.Keywords: COPD, exacerbation, inflammation, therapy
Involvement of the opportunistic pathogen Aspergillus tubingensis in osteomyelitis of the maxillary bone: a case report
Bathoorn Erik,Escobar Salazar Natalia,Sepehrkhouy Shahrzad,Meijer Martin
BMC Infectious Diseases , 2013, DOI: 10.1186/1471-2334-13-59
Abstract: Background Aspergillus tubingensis is a black Aspergillus belonging to the Aspergillus section Nigri, which includes species that morphologically resemble Aspergillus niger. Recent developments in species determination have resulted in clinical isolates presumed to be Aspergillus niger being reclassified as Aspergillus tubingensis by sequencing. We present a report of a patient with an osteomyelitis of the maxillary bone with a probable invasive Aspergillus tubingensis infection. Case presentation We describe an immune compromised patient suffering from osteomyelitis of the maxillary bone after tooth extraction. The osteomyelitis probably resulted in dentogenic pansinusitis presenting as an acute ethmoiditis. Histologic examination of biopsy samples showed osteomyelitis, and inflammation of the surrounding connective tissue. Cultures of the alveolar wound grew Aspergillus tubingensis. The patient was treated with liposomal amphoterocin B, which was changed to oral treatment with voriconazole based on susceptibility testing (MIC for voriconazole was 1 μg/ml). Conclusion This case shows that Aspergillus tubingensis may have the potential to cause severe invasive infections in immunocompromised hosts. A larger proportion of Aspergillus tubingensis isolates are less susceptible to azoles compared to Aspergillus niger. Therefore, correct species identification and susceptibility testing is crucial for the choice of anti-fungal treatment, screening of azole resistance, and characterization of the pathogenic potential of the various species within Aspergillus section Nigri.
Cytotoxicity and Induction of Inflammation by Pepsin in Acid in Bronchial Epithelial Cells
Erik Bathoorn,Paul Daly,Birgit Gaiser,Karl Sternad,Craig Poland,William MacNee,Ellen M. Drost
International Journal of Inflammation , 2011, DOI: 10.4061/2011/569416
Abstract: Introduction. Gastroesophageal reflux has been associated with chronic inflammatory diseases and may be a cause of airway remodelling. Aspiration of gastric fluids may cause damage to airway epithelial cells, not only because acidity is toxic to bronchial epithelial cells, but also since it contains digestive enzymes, such as pepsin. Aim. To study whether pepsin enhances cytotoxicity and inflammation in airway epithelial cells, and whether this is pH-dependent. Methods. Human bronchial epithelial cells were exposed to increasing pepsin concentrations in varying acidic milieus, and cell proliferation and cytokine release were assessed. Results. Cell survival was decreased by pepsin exposure depending on its concentration ( ) and pH level of the medium ( ) (both ). Pepsin-induced interleukin-8 release was greater at lower pH ( ; ). Interleukin-6 induction by pepsin was greater at pH 1.5 compared to pH 2.5 (mean difference 434%; ). Conclusion. Pepsin is cytotoxic to bronchial epithelial cells and induces inflammation in addition to acid alone, dependent on the level of acidity. Future studies should assess whether chronic aspiration causes airway remodelling in chronic inflammatory lung diseases. 1. Introduction Aspiration of gastric fluids damages airway epithelial cells [1] due to the toxicity of its low pH [2]. Several in vivo and in vitro models have assessed the effect of acid aspiration on lung injury and inflammation, using a hydrochloric acid solution with a pH ranging from 1 to 1.5 [2–5]. In addition, gastric particles have been found to contribute to lung injury [6]. Previous in vivo and in vitro studies have shown that acid aspiration causes an IL-6 and IL-8 mediated neutrophil influx into the lungs [2, 3, 7, 8]. A correlation between acid aspiration, increased IL-8 levels, and airway neutrophil counts has been found in asthma patients [9]. However, the acidity of gastric fluids might not be the only cause of damage and inflammatory response. Digestive enzymes such as pepsin might be an important factor as well. Pepsin is stored as inactive pepsinogen in the chief cells of the gastric mucosa. It is a protease involved in the digestion of food, and its activity is acid-dependent. The conversion of pepsinogen to pepsin in the stomach starts slowly at pH 6 and reaches optimal activity between pH 1.5 to 2.5. Above pH 6.8, pepsin becomes inactive and above pH 7.5 it is fully inactive and irreversibly denatured [10]. In human gastric fluid, the pH varies from 1.5 to 3, which agrees with pepsin’s activity optimum, and the concentration of pepsin varies
Change in inflammation in out-patient COPD patients from stable phase to a subsequent exacerbation
Erik Bathoorn,Jeroen JW Liesker,Dirkje S Postma,Gerard H Koëter
International Journal of COPD , 2009,
Abstract: Erik Bathoorn1, Jeroen JW Liesker1, Dirkje S Postma1, Gerard H Ko ter1, Marco van der Toorn2, Sicco van der Heide2, H Alec Ross3, Antoon JM van Oosterhout2, Huib AM Kerstjens11Department of Pulmonology; 2Laboratory of Allergology and Pulmonary Diseases, Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of Groningen, the Netherlands; 3Department of Chemical Endocrinology, Radboud University Nijmegen Medical Centre, the NetherlandsBackground: Inflammation increases during exacerbations of COPD, but only a few studies systematically assessed these changes. Better identification of these changes will increase our knowledge and potentially guide therapy, for instance by helping with quicker distinction of bacterially induced exacerbations from other causes.Aim: To identify which inflammatory parameters increase during COPD exacerbations compared to stable disease, and to compare bacterial and non-bacterial exacerbations.Methods: In 45 COPD patients (37 male/8 female, 21 current smokers, mean age 65, FEV1 52% predicted, pack years 38) sputum was collected during a stable phase and subsequently during an exacerbation.Results: Sputum total cell counts (9.0 versus 7.9 × 106/mL), eosinophils (0.3 versus 0.2 × 106/mL), neutrophils (6.1 versus 5.8 × 106/mL), and lymphocytes (0.07 versus 0.02 × 106/mL) increased significantly during an exacerbation compared to stable disease. A bacterial infection was demonstrated by culture in 8 sputum samples obtained during an exacerbation. These exacerbations had significantly increased sputum total cell and neutrophil counts, leukotriene-B4, myeloperoxidase, interleukin-8 and interleukin-6, and tumor necrosis factor-α (TNF-α) levels, and were also associated with more systemic inflammation compared to exacerbations without a bacterial infection. Sputum TNF-α level during an exacerbation had the best test characteristics to predict a bacterial infection.Conclusion: Sputum eosinophil, neutrophil, and lymphocyte counts increase during COPD exacerbations. The increase in systemic inflammation during exacerbations seems to be limited to exacerbations caused by bacterial infections of the lower airways. Sputum TNF-α is a candidate marker for predicting airway bacterial infection.Keywords: chronic obstructive pulmonary disease, exacerbation, inflammation, sputum induction
Change in inflammation in out-patient COPD patients from stable phase to a subsequent exacerbation
Erik Bathoorn, Jeroen JW Liesker, Dirkje S Postma, Gerard H Ko ter, Marco van der Toorn, et al
International Journal of Chronic Obstructive Pulmonary Disease , 2009, DOI: http://dx.doi.org/10.2147/COPD.S4854
Abstract: nge in inflammation in out-patient COPD patients from stable phase to a subsequent exacerbation Original Research (4733) Total Article Views Authors: Erik Bathoorn, Jeroen JW Liesker, Dirkje S Postma, Gerard H Ko ter, Marco van der Toorn, et al Published Date February 2009 Volume 2009:4 Pages 101 - 109 DOI: http://dx.doi.org/10.2147/COPD.S4854 Erik Bathoorn1, Jeroen JW Liesker1, Dirkje S Postma1, Gerard H Ko ter1, Marco van der Toorn2, Sicco van der Heide2, H Alec Ross3, Antoon JM van Oosterhout2, Huib AM Kerstjens1 1Department of Pulmonology; 2Laboratory of Allergology and Pulmonary Diseases, Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of Groningen, the Netherlands; 3Department of Chemical Endocrinology, Radboud University Nijmegen Medical Centre, the Netherlands Background: Inflammation increases during exacerbations of COPD, but only a few studies systematically assessed these changes. Better identification of these changes will increase our knowledge and potentially guide therapy, for instance by helping with quicker distinction of bacterially induced exacerbations from other causes. Aim: To identify which inflammatory parameters increase during COPD exacerbations compared to stable disease, and to compare bacterial and non-bacterial exacerbations. Methods: In 45 COPD patients (37 male/8 female, 21 current smokers, mean age 65, FEV1 52% predicted, pack years 38) sputum was collected during a stable phase and subsequently during an exacerbation. Results: Sputum total cell counts (9.0 versus 7.9 × 106/mL), eosinophils (0.3 versus 0.2 × 106/mL), neutrophils (6.1 versus 5.8 × 106/mL), and lymphocytes (0.07 versus 0.02 × 106/mL) increased significantly during an exacerbation compared to stable disease. A bacterial infection was demonstrated by culture in 8 sputum samples obtained during an exacerbation. These exacerbations had significantly increased sputum total cell and neutrophil counts, leukotriene-B4, myeloperoxidase, interleukin-8 and interleukin-6, and tumor necrosis factor-α (TNF-α) levels, and were also associated with more systemic inflammation compared to exacerbations without a bacterial infection. Sputum TNF-α level during an exacerbation had the best test characteristics to predict a bacterial infection. Conclusion: Sputum eosinophil, neutrophil, and lymphocyte counts increase during COPD exacerbations. The increase in systemic inflammation during exacerbations seems to be limited to exacerbations caused by bacterial infections of the lower airways. Sputum TNF-α is a candidate marker for predicting airway bacterial infection.
An Exceptional Generalization of the Poisson Distribution  [PDF]
Per-Erik Hagmark
Open Journal of Statistics (OJS) , 2012, DOI: 10.4236/ojs.2012.23039
Abstract: A new two-parameter count distribution is derived starting with probabilistic arguments around the gamma function and the digamma function. This model is a generalization of the Poisson model with a noteworthy assortment of qualities. For example, the mean is the main model parameter; any possible non-trivial variance or zero probability can be attained by changing the other model parameter; and all distributions are visually natural-shaped. Thus, exact modeling to any degree of over/under-dispersion or zero-inflation/deflation is possible.
Global Environmental Coordination: How to Overcome the Double Collective Action Problematic?  [PDF]
Jan-Erik Lane
Sociology Mind (SM) , 2013, DOI: 10.4236/sm.2013.31013
Abstract:

The need for stronger global coordination of environmental policies has become ever more obvious, but there are no formal arrangements in sight. The UN framework of UNEP is not delivering effective policies. Only global environmental coordination on the successful model of the World Band and the IMF can stem the rising emissions numbers and projections—quantitative voting reflecting the differences in size between the states of the world. However, the system of weighted voting typical of the WB and the IMF must be reformed in an egalitarian manner, when a global ecology organisation is set up, reducing their excessive voting power disparities. This paper suggests a simple but effective mechanism for reducing these voting power disparities, decreasing all member country votes by either the square root or the cube root expression.

Team Training, Team Learning, Leadership and Psychology Safety: A Study of Team Training and Team Learning Behavior during a Swedish Military Staff Exercise  [PDF]
Erik Hedlund, Johan ?sterberg
Sociology Mind (SM) , 2013, DOI: 10.4236/sm.2013.31014
Abstract:

The critical dependence of armed forces on teams carrying out tasks in a continuously changing, uncertain and often dangerous environment, raises questions about how to better understand factors that enable or hamper effective team learning. So far there is no developed field of research into team learning in the Swedish Armed Forces. This is the first of several studies within the Swedish Armed Forces to explore and gain a better understanding of team learning. In this first study of team learning we followed a military staff exercise. The theoretical base in this study is Amy Edmondson’s theoretical model for studying and analyzing team learning. The model consists of context support, team leader coaching, team psychology safety and team learning behavior. The results of this study supports the theoretical model of team learning and describe factors that are important for creating good conditions for team learning behavior.

Into the Desert: Solitude in Culture and Literature  [PDF]
Svend Erik Larsen
Advances in Literary Study (ALS) , 2013, DOI: 10.4236/als.2013.13007
Abstract:

Most studies of solitude have focused on the modern individualized sense of solitude, located or originating in urbanized Western cultures where solitude is seen as a companion to urban modernity. In this perspective the larger historical and cultural context goes almost unnoticed together with the fact that the preoccupation with solitude, in various forms and functions, has been around for a longer time span than Modernity and with a broader cross-cultural perspective. However, the basic cultural function of the various understandings of solitude is the same across cultures: a negotiation of the boundaries of the human life world, but in forms that are historically contextualized and differentiated. With texts from William Shakespeare to J. M. Coetzee and with references to older mythology and its modern recycling this paper tries to capture the broader historical development of solitude in European culture as an imagined position on the boundary of the human life world.

The Principal-Agent Approach to Politics: Policy Implementation and Public Policy-Making  [PDF]
Jan-Erik Lane
Open Journal of Political Science (OJPS) , 2013, DOI: 10.4236/ojps.2013.32012
Abstract:

The principal-agent models may be employed to elucidate central problems in interaction between principals and agents in both policy implementation and public policy-making concerning performance and remuneration. One then hits upon the double principal-agent relationships that are typical of the policy cycle, from policy-making to policy implementation and back: 1) government as principal for agents in public service delivery; 2) the population as principal for political agents under various forms of rulership.

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