| 1. |
- Hussain, Rashida, 1976-
(författare)
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Cell responses in infected and cystic fibrosis respiratory epithelium
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Respiratory Epithelium. Örebro Studies in Medicine 99. Cystic fibrosis (CF) is caused by a mutation in a cAMP-activated chloride (Cl-) channel (CFTR). Mortality and morbidity in CF is mainly due to the deregulated responses of the airway epithelial cells. The purpose of the thesis was to investigate the behaviour of the airway epithelial cells that are involved in maintaining the homeostasis in the airways.Nasal brush biopsies obtained from anesthetized human nasal mucosa can be an easy source to establish primary epithelial cell lines (Paper I). We found that CF and non CF cellular models cannot fully show the relation between CFTR and the phenotypic differences between CF and healthy cells (Paper II). The possibility to correct the Cl- transport defect in CF by the use of stable NOdonors, and ambroxol was investigated. NO-donors stimulated Cl- efflux, and decreased ENaC mRNA expression in CFBE cells (Paper III), while ambroxol increased Cl- efflux from CFBE cells, and showed a positive effect on the biosynthesis of CFTR (Paper IV). This suggests that these substances may be a potentially interesting group of compounds for the treatment of CF. Increased levels of IL-6 and IL-8 upon infection in CF cells can increase the susceptibility of P. aeruginosa infected CF cells to apoptosis and/or internalization of these bacteria in CF cells and hence, may have important roles in the pathology of P. aeruginosa infection in CF airways. If internalization is beneficial for the host then glucocorticoids (GCs) are not beneficial for the treatment of CF patients. However, GCs may improve airway hydration. Whether the benefits of GC treatment outweigh the negative effects is questionable, and further clinical studies need to be carried out (Paper V). The neonatal isolates S. epidermidis 94B080 and S. aureus 90B083 can modulate CFTR and ENaC expression in airway epithelial cells, which may disturb the ion transport in the respiratory epithelium upon bacterial exposure. Airway epithelial cells also show excessive inflammatory responses to these bacteria, which means that these bacteria may induce pulmonary inflammation (Paper VI).
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| 2. |
- Hussain, Rashida, 1976-, et al.
(författare)
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Effect of IL-6, IL-8 and glucocorticoids on the internalization of Pseudomonas aeruginosa (ATCC 27853) in cystic fibrosis bronchial epithelial cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Pseudomonas aeruginosa infection is common in cystic fibrosis (CF). Uptake of P. aeruginosa by the cell and the subsequent apoptosis may prevent colonization of P. aeruginosa in CF airways. CF airways have elevated levels of IL-6 and IL-8. Glucocorticoids (GCs) are anti-inflammatory but their use in CF is controversial. We studied the effect of IL- 6, IL-8 and GCs on bacterial internalization, apoptosis, and intracellular Ca2+concentration in CF bronchial epithelial (CFBE) cells and found that increased levels of IL-6 and IL-8 can increase the susceptibility of P. aeruginosa infected cells to apoptosis and/or internalization of these bacteria in CF cells. GCs decreased the extent of apoptosis in CFBE cells infected with P. aeruginosa, but may improve airway hydration by increasing the intracellular Ca2+ concentration. None of the GCs and cytokines affected apoptosis in cells not exposed to Pseudomonas. We conclude that increased levels of IL-6 and IL-8 may have important roles in the pathology of P. aeruginosa infection in CF airways. If internalization is beneficial for the host then GCs are not beneficial for the treatment of CF patients. Whether the benefits of GC treatment outweigh the negative effects is questionable, and further clinical studies need to be carried out.
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| 3. |
- Hussain, Rashida, 1976-, et al.
(författare)
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Glucocorticoids can affect Pseudomonas aeruginosa (ATCC 27853) internalization and intracellular calcium concentration in cystic fibrosis bronchial epithelial cells
- 2015
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Ingår i: Experimental Lung Research. - : Taylor & Francis. - 0190-2148 .- 1521-0499. ; 41:7, s. 383-392
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objective: Glucocorticoids (GCs) are anti-inflammatory agents, but their use in cystic fibrosis (CF) is controversial. In CF, the early colonization with Pseudomonas aeruginosa is mainly due to nonmucoid strains that can internalize, and induce apoptosis in the epithelial cells. Uptake of P. aeruginosa by the epithelial cells and subsequent apoptosis may prevent colonization of P. aeruginosa in CF airways. In the airway epithelia, several other biological effects, including an anti-secretory role by decreasing intracellular Ca2+ concentration have been described for this anti-inflammatory drug. However, the effects of GCs on the nonmucoid P. aeruginosa internalization and intracellular Ca2+ in CF bronchial epithelial cells have not been evaluated.Methods: We used cultured human CF bronchial airway epithelial cell (CFBE) monolayers to determine P. aeruginosa internalization, apoptosis, and intracellular Ca(2+)concentration in CF bronchial epithelial cells. Cells were treated with IL-6, IL-8, dexamethasone, betamethasone, or budesonide.Results: GCs in co-treatments with IL-6 reversed the effect of IL-6 by decreasing the internalization of P. aeruginosa in the CFBE cells. GCs decreased the extent of apoptosis in CFBE cells infected with internalized P. aeruginosa, and increased the intracellular Ca2+ concentration.Conclusion: These findings suggest that if internalization of P. aeruginosa reduces infection, GC therapy would increase the risk of pulmonary infection by decreasing the internalization of P. aeruginosa in CF cells, but GCs may improve airway hydration by increasing the intracellular Ca2+ concentration. Whether the benefits of GC treatment outweigh the negative effects is questionable, and further clinical studies need to be carried out.
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| 4. |
- Karpati, Ferenc
(författare)
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Bacterial colonisation and infection of the lower airways in cystic fibrosis : a microbiological and clinical study
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Pulmonary deterioration has remained the major cause of mortality in cystic fibrosis (C17) patients despite the considerable improvement of their survival due to more efficient therapy and centralised care. The progression of the CF lung disease is correlated to inflection with a limited number of colonising bacterial species. An inflammatory reaction in the lung occurs early. The general aim of this thesis was to study the bacterial colonisation in the lower airways of CF patients, and the concomitant inflammatory reaction. Paper I is a retrospective study of the chronic bacterial colonisation with Stenotrophomonas maltophilia in 12 CF patients during 1983-1992. No background factors for chronic colonisation could be verified in our material. An epidemiologic outbreak was not seen. The patients were older at the time of first isolation of S. maltophilia compared to that of Pseudomonas aeruginosa. Chronic colonisation implied a deterioration of the lung function during follow-up. The lung function of the patients was significantly worse at first isolation of S. maltophilia compared to controls colonised with P. aeruginosa at similar ages. Chronic colonisation and repeated antibiotic treatments resulted in rapid development of antimicrobial resistance. Thus, S. maltophilia is a pathogenic bacterium in patients with CF and a marker of lung disease. Paper II evaluates multiplex PCR-based detection of P. aeruginosa, S. maltophilia and Burkholderia cepacia in 90 sputum specimens compared to culture. Our data indicate high sensitivity (93%) regarding the detection of P. aeruginosa and high specificity regarding all three genera examined. The greatest gains with this method could be made when used for the early detection of P. aeruginosa in sputum-producing CF patients. Paper III describes typing of 39 clinical isolates of B. cepacia, which is an important pathogen, often associated with deterioration of the CF lung status. It exhibits a considerable phenotypic polymorphism. Typing by arbitrarily primed (AP)-PCR. using ERIC primer was performed for epidemiologic subtyping. Genetic changes were detected by analysis of shifts in the band patterns that were individual. Partial species identification could effectively be obtained by sequencing the V3 region of the 16S RNA gene. Heterogeneity of the bases was revealed in the same region in 10 of 37 strains, indicating at least two different types of 16S rRNA in the same cell. Most of the 14 CF patients, to whom 33 of the isolates belonged, developed severe lung disease after colonisation with Burkholderia, irrespective of the typing results. Paper IV investigates TN17-oc and IL-8 levels of sputum in 10 CF patients during exacerbation and the baseline levels of IL-8 in 48 sputum-producing CF patients. High IL-8 and TNF-[alpha] values in sputum seemed to correlate with clinical symptoms of deterioration and could be valuable diagnostic parameters. Our data also indicated a correlation between current bacterial colonisation with either P. aeruginosa or S. aureus in the lower airways and IL-8 concentrations in sputum. IL-8 in the sputum of CF patients seems to be a useful marker of both current bacterial colonisation and the degree of lung damage. Paper V evaluates the effect of 14-day ibuprofen therapy with special regard to IL-8 levels in sputum of 19 CF patients in clinically stable condition. The study was performed double-blinded, placebo-controlled in a crossover manner. Ibuprofen therapy did not result in significantly decreased IL-8 concentrations in the sputum of these CF patients with relatively advanced pulmonary disease. Slightly lower levels during day 8-14 of ibuprofen therapy were seen. Prescribing ibuprofen for this group of CF patients may need individual evaluation and will probably not be a general alternative.
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| 5. |
- Knudsen, Per Kristian, et al.
(författare)
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Differences in prevalence and treatment of Pseudomonas aeruginosa in cystic fibrosis centres in Denmark, Norway and Sweden
- 2009
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Ingår i: Journal of Cystic Fibrosis. - : Elsevier BV. - 1569-1993 .- 1873-5010. ; 8:2, s. 135-142
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chronic Pseudomonas aeruginosa (PA) infection causes increased morbidity and mortality in cystic fibrosis (CF). This study aimed to answer the following questions: Does the prevalence of chronic infection with PA differ between the CF centres in Scandinavia? Which differences exist concerning segregation and treatment of PA? METHODS: 989 patients (86%) from all eight CF-centres in Scandinavia were included. Demographic and clinical data, including PA colonisation status based on cultures and serology, were recorded at inclusion. The patients were followed prospectively for 1 year, recording number of days with anti-PA antibiotic treatment. RESULTS: In all pancreatic insufficient (PI) patients (n=890) the prevalence of chronic PA infection at each centre ranged from 25.8% to 48.9%, but were not significantly different. In PI patients <19 years the prevalence was 14.5% in Copenhagen compared to 30.9% in the Swedish centres pooled (p=0.001). In intermittently colonised PI patients <19 years the median number of days per year on anti-PA antibiotics was almost 6 times higher in Copenhagen (mean 86 (110), median 61 days) compared to the Swedish centres pooled (mean 27 (52), median 11 days) (p=0.037). The pulmonary function was similar. CONCLUSIONS: It is possible to maintain a very low prevalence of chronic PA infection in CF patients <19 years. We speculate that this was most likely due to a very intensive treatment of intermittently colonised patients with inhaled anti-PA antibiotics over prolonged periods of time in some centres. Since lung function was similar in centres with less intensive use of inhaled antibiotics, studies comparing different treatment modalities and other parts of CF care are needed to define the best clinical practice, including how to use antibiotics in the most rational way.
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| 6. |
- Pressler, Tacjana, et al.
(författare)
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Diagnostic significance of measurements of specific IgG antibodies to Pseudomonas aeruginosa by three different serological methods
- 2009
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Ingår i: Journal of Cystic Fibrosis. - : Elsevier BV. - 1873-5010 .- 1569-1993. ; 8:1, s. 37-42
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to evaluate three serological methods for their ability to identify CF patients in different infection status especially those at risk of developing chronic Pseudomonas aeruginosa (Pa) infection. Methods: Two ELISA methods: exotoxin A (ExoA) and CF-IgG-ELISA (CF-IgG) and Crossed Immunoelectrophoresis (CIE) were used for measurement of Pa-antibodies in sera from 791 Scandinavian CF patients. Results: 381 patients were cultured negative for Pa in the year before study start, 129 patients were intermittently colonized and 281 patients were chronically infected. The sensitivity of the investigated assays was 96%, 93% and 97%, specificity 89%, 89% and 83% for CIE, ExoA and CF-IgG respectively. The negative predictive value was for CIE 97%, for ExoA 95% and for CF-IgG 98% and positive predictive values 87%, 86% and 80%. Out of the 381 patients cultured negative for Pa, 11 changed status to chronically infected. Twenty-four out of the 129 patients intermittently colonized became chronically infected. The antibody levels in this latter group of patients were significantly higher already at the study start and increased significantly during the study period (p < 0.05). Elevated levels of specific anti-Pseudomonal antibodies showed to be the risk factor for developing chronic P. aeruginosa infection (OR 4.9 and OR 2.7, p < 0.05 for CF-IgG and ExoA). Conclusion: All three serological assays were equally informative. The very high sensitivity of the assays made it possible to characterize patients with different infection status. Elevated levels of specific anti-Pseudomonas antibodies showed to be the risk factor for developing chronic Pa infection. Due to the specificity of the tests, antibiotic treatment based on serology might be considered in selected cases. There is a window of opportunity for suppression and eradication of initial P aeruginosa infection making measurement of specific anti-Pseudomonas antibodies helpful. (c) 2008 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
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