300 research outputs found
Patterns and characterization of COPD exacerbations using real-time data collection
Stanley I Ejiofor,1,2 Jan Stolk,3 Pablo Fernandez,4 Robert A Stockley1,2 1Centre for Translational Inflammation Research, University of Birmingham, 2ADAPT Project, University Hospital Birmingham, Birmingham, UK; 3Leiden University Medical Centre, Leiden, the Netherlands; 4Independent consultant, Penn, UK Introduction: Patients with chronic obstructive pulmonary disease often experience exacerbations. These events are important as they are a major cause of morbidity and mortality. Recently, it has been increasingly recognized that patients may experience symptoms suggestive of an exacerbation but do not seek treatment, which are referred to as unreported or untreated exacerbations. Symptom diaries used in clinical trials have the benefit of identifying both treated and untreated exacerbation events. Methods: The Kamada study was a multicenter, double-blind randomized controlled trial of inhaled augmentation therapy in alpha-1 antitrypsin deficiency (AATD). A retrospective review of daily electronic symptom diary cards was undertaken from the two leading centers to identify symptomatic episodes consistent with a definition of an exacerbation. The aims were to explore the relationship between exacerbation events and classical “Anthonisen” symptoms and to characterize treated and untreated episodes. Results: Forty-six AATD patients with airflow obstruction and history of exacerbations were included in the analysis. Two hundred thirty-three exacerbation episodes were identified: 103 untreated and 130 treated. Untreated episodes were significantly shorter (median 6 days; interquartile range [IQR] 3–10 days) than the treated episodes (median 10 days; IQR 5–18.25 days: P<0.001). Using logistic regression analysis, Anthonisen type and length of dyspnea were significant predictors of the treatment of an exacerbation event. Conclusion: Real-time electronic diary cards provide valuable information about the characterization of exacerbations. Untreated episodes are common and are significantly shorter in duration than the treated episodes. Dyspnea is the most important single Anthonisen symptom in the prediction and/or driver of treatment. Keywords: exacerbations, alpha-1 antitrypsin deficiency, COP
Small coastal streams - Critical reservoirs of genetic diversity for trout (Salmo trutta L.) in the face of increasing anthropogenic stressors
This is the final version. Available on open access from Wiley via the DOI in this recordWe used microsatellite markers to investigate levels and structuring of genetic diversity in trout (Salmo trutta L.) sampled from 16 rivers along the south coast of Cornwall in southwest England. This region is characterized by many small coastal streams with a few larger catchments. At a regional level, genetic structuring of contemporary populations has been influenced by a combination of events, including the last Ice Age and also more recent human activities over the last millennium. All populations are shown to have gone through strong genetic bottlenecks, coinciding with increased exploitation of mineral resources within catchments, beginning during the Medieval period. At more local levels, contemporary human-induced habitat fragmentation, such as weir and culvert construction, has disproportionally affected trout populations in the smaller catchments within the study area. However, where small catchments are relatively unaffected by such activities, they can host trout populations with diversity levels comparable to those found in larger rivers in the region. We also predict significant future loses of diversity and heterozygosity in the trout populations inhabiting small, isolated catchments. Our study highlights how multiple factors, especially the activity of humans, have and continue to affect the levels and structuring of genetic diversity in trout over long timescales.European Union 2007‐2013 Atlantic Area Programme INTERREG III B initiativeAtlantic Salmon TrustSalmonid Management Around the Channel (SAMARCH) projec
Relative influence of shredders and fungi on leaf litter decomposition along a river altitudinal gradient
We compared autumn decomposition rates of European alder leaves at four sites along the Lasset–Hers River system, southern France, to test whether changes in litter decomposition rates from upstream (1,300 m elevation) to downstream (690 m) could be attributed to temperature-driven differences in microbial growth, shredder activity, or composition of the shredder community. Alder leaves lost 75–87% of original mass in 57 days, of which 46–67% could be attributed to microbial metabolism and 8–29% to shredder activity, with no trend along the river. Mass loss rates in both fine-mesh (excluding shredders) and coarse-mesh (including shredders) bags were faster at warm, downstream sites (mean daily temperature 7–8°C) than upstream (mean 1–2°C), but the differ- ence disappeared when rates were expressed in heat units to remove the temperature effect. Mycelial biomass did not correlate with mass loss rates. Faster mass loss rates upstream, after temperature correction, evidently arise from more efficient shredding by Nemourid stoneflies than by the Leuctra-dominated assemblage downstream. The influence of water temperature on decomposition rate is therefore expressed both directly, through microbial metabolism, and indirectly, through the structure of shredder commu- nities. These influences are evident even in cold water where temperature variation is small
Postcopulatory Sexual Selection Is Associated with Reduced Variation in Sperm Morphology
The evolutionary role of postcopulatory sexual selection in shaping male reproductive traits, including sperm morphology, is well documented in several taxa. However, previous studies have focused almost exclusively on the influence of sperm competition on variation among species. In this study we tested the hypothesis that intraspecific variation in sperm morphology is driven by the level of postcopulatory sexual selection in passerine birds.Using two proxy measures of sperm competition level, (i) relative testes size and (ii) extrapair paternity level, we found strong evidence that intermale variation in sperm morphology is negatively associated with the degree of postcopulatory sexual selection, independently of phylogeny.Our results show that the role of postcopulatory sexual selection in the evolution of sperm morphology extends to an intraspecific level, reducing the variation towards what might be a species-specific 'optimum' sperm phenotype. This finding suggests that while postcopulatory selection is generally directional (e.g., favouring longer sperm) across avian species, it also acts as a stabilising evolutionary force within species under intense selection, resulting in reduced variation in sperm morphology traits. We discuss some potential evolutionary mechanisms for this pattern
Cardiovascular disease in Alpha 1 antitrypsin deficiency: an observational study assessing the role of neutrophil proteinase activity and the suitability of validated screening tools
BACKGROUND: Alpha 1 Antitrypsin Deficiency (AATD) is a rare, inherited lung disease which shares features with Chronic Obstructive Pulmonary Disease (COPD) but has a greater burden of proteinase related tissue damage. These proteinases are associated with cardiovascular disease (CVD) in the general population. It is unclear whether patients with AATD have a greater risk of CVD compared to usual COPD, how best to screen for this, and whether neutrophil proteinases are implicated in AATD-associated CVD. This study had three aims. To compare CVD risk in never-augmented AATD patients to non-AATD COPD and healthy controls (HC). To assess relationships between CVD risk and lung physiology. To determine if neutrophil proteinase activity was associated with CVD risk in AATD. Cardiovascular risk was assessed by QRISK2® score and aortic stiffness measurements using carotid-femoral (aortic) pulse wave velocity (aPWV). Medical history, computed tomography scans and post-bronchodilator lung function parameters were reviewed. Systemic proteinase 3 activity was measured. Patients were followed for 4 years, to assess CVD development. RESULTS: 228 patients with AATD, 50 with non-AATD COPD and 51 healthy controls were recruited. In all COPD and HC participants, QRISK2® and aPWV gave concordant results (with both measures either high or in the normal range). This was not the case in AATD. Once aPWV was adjusted for age and smoking history, aPWV was highest and QRISK2® lowest in AATD patients compared to the COPD or HC participants. Higher aPWV was associated with impairments in lung physiology, the presence of emphysema on CT scan and proteinase 3 activity following adjustment for age, smoking status and traditional CVD risk factors (using QRISK2® scores) in AATD. There were no such relationships with QRISK2® in AATD. AATD patients with confirmed CVD at four-year follow up had a higher aPWV but not QRISK2® at baseline assessment. CONCLUSION: aPWV measured CVD risk is elevated in AATD. This risk is not captured by QRISK2®. There is a relationship between aPWV, lung disease and proteinase-3 activity. Proteinase-driven breakdown of elastin fibres in large arteries and lungs is a putative mechanism and forms a potential therapeutic target for CVD in AATD
A low-density single nucleotide polymorphism panel for brown trout (Salmo trutta L.) suitable for exploring genetic diversity at a range of spatial scales
This is the final version. Available on open access from Wiley via the DOI in this recordThe rivers of southern England and northern France which drain into the English Channel contain several genetically unique groups of trout (Salmo trutta L.) that have suffered dramatic declines in numbers over the past 40 years. Knowledge of levels and patterns of genetic diversity is essential for effective management of these vulnerable populations. Using restriction site-associated DNA sequencing (RADseq) data, we describe the development and characterisation of a panel of 95 single nucleotide polymorphism (SNP) loci for trout from this region and investigate their applicability and variability in both target (i.e., southern English) and non-target trout populations from northern Britain and Ireland. In addition, we present three case studies which demonstrate the utility and resolution of these genetic markers at three levels of spatial separation:(a) between closely related populations in nearby rivers, (b) within a catchment and (c) when determining parentage and familial relationships between fish sampled from a single site, using both empirical and simulated data. The SNP loci will be useful for population genetic and assignment studies on brown trout within the UK and beyond.European Union Interreg France (Channel) England programmeWestcountry Rivers Trus
Moraxella catarrhalis acquisition, airway inflammation and protease-antiprotease balance in chronic obstructive pulmonary disease
<p>Abstract</p> <p>Background</p> <p><it>Moraxella catarrhalis </it>causes approximately 10% of exacerbations in chronic obstructive pulmonary disease (COPD) and also colonizes the lower airway in stable patients. Little is known about the effects of colonization by <it>M. catarrhalis </it>on airway inflammation and protease-antiprotease balance, and how these changes compare to those seen during exacerbations. Since COPD is a progressive inflammatory disease, elucidating the effects of bacterial colonization and exacerbation on airway inflammation is relevant to understanding disease progression in COPD. Our aims were (1) Analyze changes in airway inflammation in colonization and exacerbation of COPD due to <it>M. catarrhalis</it>; (2) Explore protease-antiprotease balance in colonization and exacerbation due to <it>M. catarrhalis</it>. Our hypothesis were (1) Acquisition of a new strain of M. catarrhalis in COPD increases airway inflammation from baseline and alters the protease-antiprotease balance towards a more proteolytic environment; (2) These changes are greater during exacerbations associated with <it>M. catarrhalis </it>as compared to colonization.</p> <p>Methods</p> <p>Thirty-nine consecutive COPD patients with 76 acquisitions of a new strain of <it>M. catarrhalis </it>over a 6-year period were identified in a prospective study. Seventy-six pre-acquisition sputum supernatant samples, obtained just before acquisition of <it>M catarrhalis</it>, and 76 acquisition samples (34 were associated with exacerbation, 42 with colonization) were analyzed for IL-8, TNF-α, Neutrophil Elastase (NE) and Secretory leukocyte protease inhibitor (SLPI). Changes were compared in paired samples from each patient.</p> <p>Results</p> <p>IL-8, TNF-α and NE were significantly elevated after acquisition of <it>M. catarrhalis</it>, compared to pre-acquisition samples (p =< 0.001 for all three). These changes were present in colonization (p = 0.015 for IL-8; p =< 0.001 for TNF-α and NE) as well as in exacerbation (p =< 0.001 for all three), compared to pre-acquisition levels. SLPI was significantly lower after acquisition (p =< 0.001), in colonization (p =< 0.001) as well as in exacerbation (p = 0.004), compared to pre-acquisition levels. SLPI levels correlated negatively with NE levels (R<sup>2 </sup>= 0.07; p = 0.001).</p> <p>Conclusion</p> <p>Acquisition of <it>M. catarrhalis </it>in COPD causes increased airway inflammation and worsening protease-antiprotease imbalance during exacerbations and also in colonization, even in the absence of increased symptoms. These effects could contribute to progression of airway disease in COPD.</p
Prolastin, a pharmaceutical preparation of purified human α1-antitrypsin, blocks endotoxin-mediated cytokine release
BACKGROUND: α1-antitrypsin (AAT) serves primarily as an inhibitor of the elastin degrading proteases, neutrophil elastase and proteinase 3. There is ample clinical evidence that inherited severe AAT deficiency predisposes to chronic obstructive pulmonary disease. Augmentation therapy for AAT deficiency has been available for many years, but to date no sufficient data exist to demonstrate its efficacy. There is increasing evidence that AAT is able to exert effects other than protease inhibition. We investigated whether Prolastin, a preparation of purified pooled human AAT used for augmentation therapy, exhibits anti-bacterial effects. METHODS: Human monocytes and neutrophils were isolated from buffy coats or whole peripheral blood by the Ficoll-Hypaque procedure. Cells were stimulated with lipopolysaccharide (LPS) or zymosan, either alone or in combination with Prolastin, native AAT or polymerised AAT for 18 h, and analysed to determine the release of TNFα, IL-1β and IL-8. At 2-week intervals, seven subjects were submitted to a nasal challenge with sterile saline, LPS (25 μg) and LPS-Prolastin combination. The concentration of IL-8 was analysed in nasal lavages performed before, and 2, 6 and 24 h after the challenge. RESULTS: In vitro, Prolastin showed a concentration-dependent (0.5 to 16 mg/ml) inhibition of endotoxin-stimulated TNFα and IL-1β release from monocytes and IL-8 release from neutrophils. At 8 and 16 mg/ml the inhibitory effects of Prolastin appeared to be maximal for neutrophil IL-8 release (5.3-fold, p < 0.001 compared to zymosan treated cells) and monocyte TNFα and IL-1β release (10.7- and 7.3-fold, p < 0.001, respectively, compared to LPS treated cells). Furthermore, Prolastin (2.5 mg per nostril) significantly inhibited nasal IL-8 release in response to pure LPS challenge. CONCLUSION: Our data demonstrate for the first time that Prolastin inhibits bacterial endotoxin-induced pro-inflammatory responses in vitro and in vivo, and provide scientific bases to explore new Prolastin-based therapies for individuals with inherited AAT deficiency, but also for other clinical conditions
Impact of statins and ACE inhibitors on mortality after COPD exacerbations
<p>Abstract</p> <p>Background</p> <p>The purpose of our study was to examine the association of prior outpatient use of statins and angiotensin converting enzyme (ACE) inhibitors on mortality for subjects ≥ 65 years of age hospitalized with acute COPD exacerbations.</p> <p>Methods</p> <p>We conducted a retrospective national cohort study using Veterans Affairs administrative data including subjects ≥65 years of age hospitalized with a COPD exacerbation. Our primary analysis was a multilevel model with the dependent variable of 90-day mortality and hospital as a random effect, controlling for preexisting comorbid conditions, demographics, and other medications prescribed.</p> <p>Results</p> <p>We identified 11,212 subjects with a mean age of 74.0 years, 98% were male, and 12.4% of subjects died within 90-days of hospital presentation. In this cohort, 20.3% of subjects were using statins, 32.0% were using ACE inhibitors or angiotensin II receptor blockers (ARB). After adjusting for potential confounders, current statin use (odds ratio 0.51, 95% confidence interval 0.40–0.64) and ACE inhibitor/ARB use (0.55, 0.46–0.66) were significantly associated with decreased 90-day mortality.</p> <p>Conclusion</p> <p>Use of statins and ACE inhibitors prior to admission is associated with decreased mortality in subjects hospitalized with a COPD exacerbation. Randomized controlled trials are needed to examine whether the use of these medications are protective for those patients with COPD exacerbations.</p
Inflammation in sputum relates to progression of disease in subjects with COPD: a prospective descriptive study
BACKGROUND: Inflammation is considered to be of primary pathogenic importance in COPD but the evidence on which current understanding is based does not distinguish between cause and effect, and no single mechanism can account for the complex pathology. We performed a prospective longitudinal study of subjects with COPD that related markers of sputum inflammation at baseline to subsequent disease progression. METHODS: A cohort of 56 patients with chronic bronchitis was characterized in the stable state at baseline and after an interval of four years, using physiological measures and CT densitometry. Sputum markers of airway inflammation were quantified at baseline from spontaneously produced sputum in a sub-group (n = 38), and inflammation severity was related to subsequent disease progression. RESULTS: Physiological and CT measures indicated disease progression in the whole group. In the sub-group, sputum myeloperoxidase correlated with decline in FEV(1 )(rs = -0.344, p = 0.019, n = 37). LTB4 and albumin leakage correlated with TLCO decline (rs = -0.310, p = 0.033, rs = -0.401, p = 0.008, respectively, n = 35) and IL-8 correlated with progression of lung densitometric indices (rs = -0.464, p = 0.005, n = 38). CONCLUSION: The data support a principal causative role for neutrophilic inflammation in the pathogenesis of COPD and suggest that the measurement of sputum inflammatory markers may have a predictive role in clinical practice
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