123 research outputs found
Patients with chronic obstructive pulmonary disease and chronically colonized with Haemophilus influenzae during stable disease phase have increased airway inflammation.
Some patients with chronic obstructive pulmonary disease (COPD) show increased airway inflammation and bacterial colonization during stable phase. The aim of this study was to follow COPD patients and investigate chronic colonization with pathogenic bacteria during stable disease phase, and relate these findings to clinical parameters, inflammatory pattern, lung function, and exacerbations
Extended diagnostic criteria used for indirect challenge testing in elite asthmatic swimmers.
The aim of the study was to investigate the prevalence of asthma with or without exercise induced symptoms among elite and elite aspiring swimmers and to compare sport specific exercise provocation with mannitol provocation. METHODS: 101 adolescent swimmers were investigated with mannitol provocation and sport specific exercise challenge test. Mannitol positivity was defined as either direct FEV(1) PD15 (ordinary criteria) or as β(2)-reversibility ≥15% after challenge (extended criteria). A direct positive exercise test was defined as a drop in FEV(1) of 10% (ordinary criteria) or a difference in FEV of ≥15% either spontaneous, variability, or with β2-agonist, reversibility (extended criteria). RESULTS: We found a high prevalence of mannitol and/or exercise positivity. Twenty-six swimmers were mannitol direct positive and 14 were direct exercise positive using ordinary criteria. Using extended criteria 43 were mannitol positive and 24 were exercise positive. When including reversibility and variability to define a positive test the sensitivity for current asthma with or without exercise induced symptoms increased while the specificity remained roughly unchanged. Direct positivity for mannitol and exercise poorly overlapped using ordinary criteria but improved using extended criteria. CONCLUSION: We found a high prevalence of asthma among elite swimmers. The use of variability and reversibility (liability) as additional criteria to define a positive test provided to our mind relevant information and should be considered
Sex differences in asthma in swimmers and tennis players
Background: Elite athletes, independent of sport, have increased risk of developing asthma, but little is known about sex difference among adolescent athletes. Objective: To investigate and compare sex-related differences according to symptoms and treatment of asthma, allergy, and health among elite athletes and a reference group. Methods: Adolescent elite swimmers (n = 101), tennis players (n = 86), and a reference group (n = 1,628) responded to a questionnaire about respiratory symptoms, allergy, health behavior, psychosomatic symptoms, self- esteem, and well-being. The athletes performed a mannitol provocation and a sport-specific exercise provocation. Atopy was assessed by skin prick tests, and fractional exhaled nitric oxide was measured. Results: The females reported more asthma symptoms than the males in both the reference group (29.1% vs 22.3%) and the athlete group (56.4% vs 40.2%). However, no significant differences were found in physician-diagnosed asthma or treatment with inhaled corticosteroids. More female athletes had a positive mannitol provocation result (48.7% vs 35.8% in male athletes), and more female swimmers had a positive exercise provocation result (15.1% vs 7.7% in male swimmers). The females in all groups had more psychosomatic symptoms compared with the respective males, and the males in the reference group reported higher self-esteem and felt more well-being compared with the reference group females. Conclusion: Overall, we found a higher prevalence of asthma symptoms in the females. However, the frequency of physician-diagnosed asthma and the prescription of inhaled corticosteroids were the same in both sexes. This finding demonstrates an insufficient diagnosis of asthma in females
Application of nitric oxide measurements in clinical conditions beyond asthma.
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This article is open access.Fractional exhaled nitric oxide (FeNO) is a convenient, non-invasive method for the assessment of active, mainly Th2-driven, airway inflammation, which is sensitive to treatment with standard anti-inflammatory therapy. Consequently, FeNO serves as a valued tool to aid diagnosis and monitoring in several asthma phenotypes. More recently, FeNO has been evaluated in several other respiratory, infectious, and/or immunological conditions. In this short review, we provide an overview of several clinical studies and discuss the status of potential applications of NO measurements in clinical conditions beyond asthma
Urinary CC16 after challenge with dry air hyperpnoea and mannitol in recreational summer athletes
Airway epithelial injury is regarded as a key contributing factor to the pathogenesis of exercise-induced bronchoconstriction (EIB) in athletes. The concentration of the pneumoprotein club cell (Clara cell) CC16 in urine has been found to be a non-invasive marker for hyperpnoea-induced airway epithelial perturbation. Exercise-hyperpnoea induces mechanical, thermal and osmotic stress to the airways. We investigated whether osmotic stress alone causes airway epithelial perturbation in athletes with suspected EIB. Twenty-four recreational summer sports athletes who reported respiratory symptoms on exertion performed a standard eucapnic voluntary hyperpnoea test with dry air and a mannitol test (osmotic challenge) on separate days. Median urinary CC16 increased from 120 to 310 ρg μmol creatinine-1 after dry air hyperpnoea (P = 0.002) and from 90 to 191 ρg μmol creatinine-1 after mannitol (P = 0.021). There was no difference in urinary CC16 concentration between athletes who did or did not bronchoconstrict after dry air hyperpnoea or mannitol. We conclude that, in recreational summer sports athletes with respiratory symptoms, osmotic stress per se to the airway epithelium induces a rise in urinary excretion of CC16. This suggests that hyperosmolarity of the airway surface lining perturbs the airway epithelium in symptomatic athletes.The study was independently supported financially by the World Anti Doping Agency (WADA). Pharmaxis Ltd. provided the mannitol kits free of charge and approved submission of the manuscript for publication
Biglycan as a modulator of fibrous connective tissue
Fibrous connective tissue contains fibroblasts distributed in a complex network of extracellular matrix molecules, such as proteoglycans. The small proteoglycans biglycan and decorin are composed of a protein core substituted with two and one glycosaminoglycan (GAG) chain, respectively. Proteoglycan metabolism is regulated differently during several processes including inflammation and wound healing. Proinflammatory cytokines, such as TNF-a and IL-1b, can affect matrix composition by increasing biglycan, versican and hyaluronan, and decreasing decorin and collagen. This results in a more loosely associated connective tissue that enhances the infiltration of inflammatory cells. Moreover, TNF-a can bind to both biglycan and decorin. In the inflammatory process, this may be of utmost importance since biglycan and decorin are located and regulated differently. The pericellular location of biglycan can enhance the binding of TNF-a to its cell surface receptors, while decorin, located in the extracellular matrix, may function as a storage depot. Besides the predominant form of biglycan, different isoforms can be secreted that possess a smaller core protein and greater diversity in the structure and length of their GAG chains. This variation in the structure of biglycan may alter its ability to bind cytokines as well as other matrix molecules potentially resulting in changes in the connective tissue formation. Biglycan and decorin also have important functions in the tissue repair process where they induce fibroblast cytoskeletal changes. These include morphological changes to a longer, stretched cell shape, formation of stress fibres and focal adhesions. These may be caused by an activation of the Rho GTPases, RhoA and Rac1, followed by an increase in migration. In summary, our results demonstrate that biglycan and decorin affect fibroblast activity and that they have a role both in physiological and pathological processes where the extracellular matrix is continuously being remodelled
Methodological improvements for measuring eicosanoids and cytokines in exhaled breath condensate.
Background: Exhaled breath condensate (EBC) is simple to cottect and as such a non-invasive method that has attracted substantial interest in the last few years. However, several methodological concerns have been raised and it has been difficult to reproduce results between different centres. Because of low concentrations of inflammatory markers, potential loss in the sampling system may have great influence. The aim of the present study was to se if evaporation and plastic coating could facilitate detection. Methodology: Through methodological improvements, we have now made it possible to measure EBC concentrations of eicosanoids and cytokines in our system. Due to absorbance of both fatty acid derivates and proteins to several plastics, the first step is coating of all surfaces with bovine serum albumin and Tween 20. Since several assays are sensitive to these factors, the methodology has to be standardised to avoid false results. Secondly, Larger amounts of EBC have to be vacuum-dried, and thereafter resolved in the respective assay buffers. The EBCs have to be concentrated 5-10 times, depending on samples and assay sensitivity. Results: Due to these improvements we can measure, for example, cysteinyl-leukotrienes, leukotriene B-4, prostaglandin E and 8-isoprostane. High sensitivity assays have also made it possible to measure cytokines, for example, interleukin (IL)-1 beta, IL-8 and IL-13. Summary: We are aware of different results from other tabs. However, it seems essential to coat and to concentrate the samples in order to achieve reliable and measurable results. (c) 2005 Elsevier Ltd. All rights reserved
Alteration of proteoglycan synthesis in human lung fibroblasts induced by interleukin-1beta and tumor necrosis factor-alpha
Important constituents of extracellular matrix are collagen, fibronectin, hyaluronan, and various types of proteoglycans, such as versican, perlecan, decorin, and biglycan. Remodeling of extracellular matrix occurs continuously and is affected by various cytokines. The aim of this study was to investigate how interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), separately and in combination, alter fibroblast proliferation, as well as the production of extracellular matrix molecules produced by human fibroblasts from lung. Fibroblast proliferation was inhibited significantly by all treatments, by 12% with IL-1beta and by 16% with TNF-alpha. The combination of IL-1beta and TNF-alpha increased the inhibition further, by 27%. Hyaluronan production was increased by all treatments: 1.7-fold by IL-1beta and 1.5-fold by TNF-alpha. The combination of the two gave a further increase (2.5-fold). Similarly, the production of total proteoglycans was increased. The small proteoglycans, decorin, and biglycan, were regulated differently. Decorin production was inhibited by about 34% by all treatments, while biglycan was upregulated 1.3-fold by TNF-alpha. Versican was upregulated by IL-1beta (1.7-fold), whereas TNF-alpha was without effect. Perlecan was mostly unaffected. The changes in protein production of the various proteoglycans were due to increased transcription, as mRNA levels were also changed to the same extent. Synthesis of mRNA for collagen type I was inhibited by up to 75% with the IL-1beta/TNF-alpha combination. The separate cytokines also decreased the level of collagen type I mRNA, but to a lesser extent: 60% with IL-1beta and 40% with TNF-alpha. In summary, our study indicates that these proinflammatory cytokines affect the regulation of extracellular matrix production, which is of importance for the inflammatory process
Tumour necrosis factor-alpha interacts with biglycan and decorin.
Several interactions of cytokines with extracellular matrix molecules are mediated by proteoglycans, such as biglycan and decorin. Using surface plasmon resonance, we show for the first time that tumour necrosis factor-alpha (TNF-alpha) binds to both biglycan and decorin with K(d)s of 0.81 microM and 1.23 microM respectively, a binding that was confirmed by Scatchard plots using a solid phase assay. Binding occurs preferentially via the core protein, shown by lower K(d)s, 0.26 microM and 0.81 microM for biglycan and decorin respectively. There was also binding to dermatan sulphate, with a K(d) of 10.53 microM. The function of this interaction between TNF-alpha and biglycan and decorin is not known, but we suggest that the differential localisation of the proteoglycans enables the cytokines to be immobilised in different environments
Biglycan and decorin induce morphological and cytoskeletal changes involving signalling by the small GTPases RhoA and Rac1 resulting in lung fibroblast migration
Biglyean and decorin are small chondroitin/dermatan sulphate proteoglycans in the extracellular matrix of connective tissue that belong to the family of structurally related proteoglycans called small leucine-rich repeat proteins. We show for the first time that biglycan and decorin induce morphological and cytoskeletal changes in fibroblasts, resulting in an increase in migration. Biglycan changed the cell shape of fibroblasts with formation of long protruding filamentous processes. This was also seen for decorin but to a lesser extent. Using fluorescence staining of F-actin fibres it was possible to show that these long filamentous processes were supported by long thick bundles of actin, together with an induced formation of stress fibres after stimulation with biglycan and decorin. Moreover, a reorganisation of a-smooth muscle actin was clearly seen in these cultures. Decorin also stimulated alpha-smooth muscle actin expression in the cells. Using cDNA Atlas Arrays we were also able to show that the mRNA level of a number of the intracellular regulators and effectors involved in cell migration were increased. For example, the focal adhesion proteins paxillin and zyxin, and some of the small Rho GTPases such as RhoA, Rac1 and Cdc42 were upregulated. After treatment with biglycan or decorin, additional results showed an increased activation of RhoA (1.8- and 1.5-fold, respectively) and Rac1 (1.8- and 1.5-fold, respectively) after 15 minutes. These factors are known to be involved in fibroblast migration, and as expected a 1.3-to 1.6-fold increase in migration could be observed after stimulation with biglycan or decorin. This induced migration was caused by the core protein, as treatment with glycosaminoglycan chains alone did not have any effect. In summary, these data indicate that biglycan- and decorin-induced fibroblast cytoskeletal and signalling changes result in an increased cell migration, and demonstrate their potential role in the remodelling process
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