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Donna E. Davies

Bio: Donna E. Davies is an academic researcher from University of Southampton. The author has contributed to research in topics: Epidermal growth factor & Asthma. The author has an hindex of 67, co-authored 253 publications receiving 17322 citations. Previous affiliations of Donna E. Davies include National Oceanography Centre, Southampton & École normale supérieure de Lyon.


Papers
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Journal ArticleDOI
TL;DR: A causal link between deficient interferon-β, impaired apoptosis and increased virus replication is demonstrated, suggesting a novel use for type I interferons in the treatment or prevention of virus-induced asthma exacerbations.
Abstract: Rhinoviruses are the major trigger of acute asthma exacerbations and asthmatic subjects are more susceptible to these infections. To investigate the underlying mechanisms of this increased susceptibility, we examined virus replication and innate responses to rhinovirus (RV)-16 infection of primary bronchial epithelial cells from asthmatic and healthy control subjects. Viral RNA expression and late virus release into supernatant was increased 50- and 7-fold, respectively in asthmatic cells compared with healthy controls. Virus infection induced late cell lysis in asthmatic cells but not in normal cells. Examination of the early cellular response to infection revealed impairment of virus induced caspase 3/7 activity and of apoptotic responses in the asthmatic cultures. Inhibition of apoptosis in normal cultures resulted in enhanced viral yield, comparable to that seen in infected asthmatic cultures. Examination of early innate immune responses revealed profound impairment of virus-induced interferon-beta mRNA expression in asthmatic cultures and they produced >2.5 times less interferon-beta protein. In infected asthmatic cells, exogenous interferon-beta induced apoptosis and reduced virus replication, demonstrating a causal link between deficient interferon-beta, impaired apoptosis and increased virus replication. These data suggest a novel use for type I interferons in the treatment or prevention of virus-induced asthma exacerbations.

1,112 citations

Journal ArticleDOI
TL;DR: In this paper, the authors show deficient induction of interferon-λs by rhinovirus in primary bronchial epithelial cells and alveolar macrophages, which was highly correlated with severity of rhinovirus induced asthma exacerbation and virus load in experimentally infected human volunteers.
Abstract: Rhinoviruses are the major cause of asthma exacerbations, and asthmatics have increased susceptibility to rhinovirus and risk of invasive bacterial infections. Here we show deficient induction of interferon-λs by rhinovirus in asthmatic primary bronchial epithelial cells and alveolar macrophages, which was highly correlated with severity of rhinovirus-induced asthma exacerbation and virus load in experimentally infected human volunteers. Induction by lipopolysaccharide in asthmatic macrophages was also deficient and correlated with exacerbation severity. These results identify previously unknown mechanisms of susceptibility to infection in asthma and suggest new approaches to prevention and/or treatment of asthma exacerbations.

927 citations

Journal ArticleDOI
TL;DR: It is found that EGF accelerated repair of scrape‐wounded monolayers and that the EGFR‐selective inhibitor, tyrphostin AG1478, inhibited both EGF‐stimulated and basal wound closure whereas dexamethasone was without effect.
Abstract: Epithelial damage and airway remodeling are consistent features of bronchial asthma and are correlated with disease chronicity, severity, and bronchial hyperreactivity. To examine the mechanisms that control bronchial epithelial repair, we investigated expression of the epidermal growth factor receptor (c-erbB1, EGFR) in asthmatic bronchial mucosa and studied repair responses in vitro. In biopsies from asthmatic subjects, areas of epithelial damage were frequently observed and exhibited strong EGFR immunostaining. EGFR expression was also high in morphologically intact asthmatic epithelium. Using image analysis, EGFR immunoreactivity (% of total epithelial area, median (range) was found to increase from 9.4 (4.1-20.4) in normal subjects (n=10) to 18.4 (9.3-28.9) in mild asthmatics (P<0.01, n=13) and 25.4 (15.4-31.8) in severe asthmatics (P<0.00, n=5). Epithelial EGFR immunoreactivity remained elevated in patients treated with corticosteroids and was positively correlated with subepithelial reticular membrane thickening. Using 16HBE 14o- bronchial epithelial cells, we found that EGF accelerated repair of scrape-wounded monolayers and that the EGFR-selective inhibitor, tyrphostin AG1478, inhibited both EGF-stimulated and basal wound closure whereas dexamethasone was without effect. Intrinsic activation of the EGFR was confirmed by analysis of tyrosine phosphorylated proteins, which revealed a rapid, damage-induced phosphorylation of the EGFR, irrespective of the presence of exogenous EGF. To assess the relationship between EGFR-mediated repair and tissue remodeling, release of the profibrogenic mediator TGF-beta2 was also measured. Scrape wounding increased release of TGF-beta2 from epithelial monolayers and EGF had no additional stimulatory effect. However, when repair was retarded with AG1478, the amount of TGF-beta2 increased significantly. These data indicate that the EGFR may play an important role in bronchial epithelial repair in asthma and that impairment of this function may augment airway remodeling.

537 citations

Journal ArticleDOI
TL;DR: The results show that the bronchial epithelial barrier in asthma is compromised, which may facilitate the passage of allergens and other agents into the airway tissue, leading to immune activation and may thus contribute to the end organ expression of asthma.
Abstract: Background Asthma is a complex disease involving gene and environment interactions. Although atopy is a strong predisposing risk factor for asthma, local tissue susceptibilities are required for disease expression. The bronchial epithelium forms the interface with the external environment and is pivotally involved in controlling tissue homeostasis through provision of a physical barrier controlled by tight junction (TJ) complexes. Objectives To explain the link between environment exposures and airway vulnerability, we hypothesized that epithelial TJs are abnormal in asthma, leading to increased susceptibility to environmental agents. Methods Localization of TJs in bronchial biopsies and differentiated epithelial cultures was assessed by electron microscopy or immunostaining. Baseline permeability and the effect of cigarette smoke and growth factor were assessed by measurement of transepithelial electrical resistance and passage of fluorescently labeled dextrans. Results By using immunostaining, we found that bronchial biopsies from asthmatic subjects displayed patchy disruption of TJs. In differentiated bronchial epithelial cultures, TJ formation and transepithelial electrical resistance were significantly lower ( P P P Conclusions Our results show that the bronchial epithelial barrier in asthma is compromised. This defect may facilitate the passage of allergens and other agents into the airway tissue, leading to immune activation and may thus contribute to the end organ expression of asthma.

531 citations

Journal ArticleDOI
TL;DR: It is proposed that impaired epithelial repair cooperates with the TH2 environment to shift the set point for communication within the trophic unit and leads to myofibroblast activation, excessive matrix deposition, and production of mediators that propagate and amplify the remodeling responses throughout the airway wall.
Abstract: During lung development, repair, and inflammation, local production of cytokines (eg, transforming growth factor-β) and growth factors (eg, epidermal growth factor) by epithelial and mesenchymal cells mediate bidirectional growth control effectively creating an epithelial-mesenchymal trophic unit. In asthma the bronchial epithelium is highly abnormal, with structural changes involving separation of columnar cells from their basal attachments and functional changes including increased expression and release of proinflammatory cytokines, growth factors, and mediator-generating enzymes. Beneath this damaged structure there is an increase in the number of subepithelial myofibroblasts that deposit interstitial collagens causing thickening and increased density of the subepithelial basement membrane. Our recent studies suggest that the extent of epithelial damage in asthma may be the result of impaired epidermal growth factor receptor–mediated repair. In view of the close spatial relationship between the damaged epithelium and the underlying myofibroblasts, we propose that impaired epithelial repair cooperates with the TH2 environment to shift the set point for communication within the trophic unit. This leads to myofibroblast activation, excessive matrix deposition, and production of mediators that propagate and amplify the remodeling responses throughout the airway wall. (J Allergy Clin Immunol 2000;105:193-204.)

516 citations


Cited by
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01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

29,323 citations

Journal ArticleDOI
TL;DR: The evidence for adverse effects on health of selected air pollutants is discussed, and it is unclear whether a threshold concentration exists for particulate matter and ozone below which no effect on health is likely.

4,010 citations

Journal ArticleDOI
Jean Bousquet, N. Khaltaev, Alvaro A. Cruz1, Judah A. Denburg2, W. J. Fokkens3, Alkis Togias4, T. Zuberbier5, Carlos E. Baena-Cagnani6, Giorgio Walter Canonica7, C. van Weel8, Ioana Agache9, Nadia Aït-Khaled, Claus Bachert10, Michael S. Blaiss11, Sergio Bonini12, L.-P. Boulet13, Philippe-Jean Bousquet, Paulo Augusto Moreira Camargos14, K-H. Carlsen15, Y. Z. Chen, Adnan Custovic16, Ronald Dahl17, Pascal Demoly, H. Douagui, Stephen R. Durham18, R. Gerth van Wijk19, O. Kalayci19, Michael A. Kaliner20, You Young Kim21, Marek L. Kowalski, Piotr Kuna22, L. T. T. Le23, Catherine Lemière24, Jing Li25, Richard F. Lockey26, S. Mavale-Manuel26, Eli O. Meltzer27, Y. Mohammad28, J Mullol, Robert M. Naclerio29, Robyn E O'Hehir30, K. Ohta31, S. Ouedraogo31, S. Palkonen, Nikolaos G. Papadopoulos32, Gianni Passalacqua7, Ruby Pawankar33, Todor A. Popov34, Klaus F. Rabe35, J Rosado-Pinto36, G. K. Scadding37, F. E. R. Simons38, Elina Toskala39, E. Valovirta40, P. Van Cauwenberge10, De Yun Wang41, Magnus Wickman42, Barbara P. Yawn43, Arzu Yorgancioglu44, Osman M. Yusuf, H. J. Zar45, Isabella Annesi-Maesano46, E.D. Bateman45, A. Ben Kheder47, Daniel A. Boakye48, J. Bouchard, Peter Burney18, William W. Busse49, Moira Chan-Yeung50, Niels H. Chavannes35, A.G. Chuchalin, William K. Dolen51, R. Emuzyte52, Lawrence Grouse53, Marc Humbert, C. M. Jackson54, Sebastian L. Johnston18, Paul K. Keith2, James P. Kemp27, J. M. Klossek55, Désirée Larenas-Linnemann55, Brian J. Lipworth54, Jean-Luc Malo24, Gailen D. Marshall56, Charles K. Naspitz57, K. Nekam, Bodo Niggemann58, Ewa Nizankowska-Mogilnicka59, Yoshitaka Okamoto60, M. P. Orru61, Paul Potter45, David Price62, Stuart W. Stoloff63, Olivier Vandenplas, Giovanni Viegi, Dennis M. Williams64 
Federal University of Bahia1, McMaster University2, University of Amsterdam3, National Institutes of Health4, Charité5, Catholic University of Cordoba6, University of Genoa7, Radboud University Nijmegen8, Transilvania University of Brașov9, Ghent University10, University of Tennessee Health Science Center11, University of Naples Federico II12, Laval University13, Universidade Federal de Minas Gerais14, University of Oslo15, University of Manchester16, Aarhus University17, Imperial College London18, Erasmus University Rotterdam19, George Washington University20, Seoul National University21, Medical University of Łódź22, Hai phong University Of Medicine and Pharmacy23, Université de Montréal24, Guangzhou Medical University25, University of South Florida26, University of California, San Diego27, University of California28, University of Chicago29, Monash University30, Teikyo University31, National and Kapodistrian University of Athens32, Nippon Medical School33, Sofia Medical University34, Leiden University35, Leiden University Medical Center36, University College London37, University of Manitoba38, University of Helsinki39, Finnish Institute of Occupational Health40, National University of Singapore41, Karolinska Institutet42, University of Minnesota43, Celal Bayar University44, University of Cape Town45, Pierre-and-Marie-Curie University46, Tunis University47, University of Ghana48, University of Wisconsin-Madison49, University of British Columbia50, Georgia Regents University51, Vilnius University52, University of Washington53, University of Dundee54, University of Poitiers55, University of Mississippi56, Federal University of São Paulo57, German Red Cross58, Jagiellonian University Medical College59, Chiba University60, American Pharmacists Association61, University of Aberdeen62, University of Nevada, Reno63, University of North Carolina at Chapel Hill64
01 Apr 2008-Allergy
TL;DR: The ARIA guidelines for the management of allergic rhinitis and asthma are similar in both the 1999 ARIA workshop report and the 2008 Update as discussed by the authors, but the GRADE approach is not yet available.
Abstract: Allergic rhinitis is a symptomatic disorder of the nose induced after allergen exposure by an IgE-mediated inflammation of the membranes lining the nose. It is a global health problem that causes major illness and disability worldwide. Over 600 million patients from all countries, all ethnic groups and of all ages suffer from allergic rhinitis. It affects social life, sleep, school and work and its economic impact is substantial. Risk factors for allergic rhinitis are well identified. Indoor and outdoor allergens as well as occupational agents cause rhinitis and other allergic diseases. The role of indoor and outdoor pollution is probably very important, but has yet to be fully understood both for the occurrence of the disease and its manifestations. In 1999, during the Allergic Rhinitis and its Impact on Asthma (ARIA) WHO workshop, the expert panel proposed a new classification for allergic rhinitis which was subdivided into 'intermittent' or 'persistent' disease. This classification is now validated. The diagnosis of allergic rhinitis is often quite easy, but in some cases it may cause problems and many patients are still under-diagnosed, often because they do not perceive the symptoms of rhinitis as a disease impairing their social life, school and work. The management of allergic rhinitis is well established and the ARIA expert panel based its recommendations on evidence using an extensive review of the literature available up to December 1999. The statements of evidence for the development of these guidelines followed WHO rules and were based on those of Shekelle et al. A large number of papers have been published since 2000 and are extensively reviewed in the 2008 Update using the same evidence-based system. Recommendations for the management of allergic rhinitis are similar in both the ARIA workshop report and the 2008 Update. In the future, the GRADE approach will be used, but is not yet available. Another important aspect of the ARIA guidelines was to consider co-morbidities. Both allergic rhinitis and asthma are systemic inflammatory conditions and often co-exist in the same patients. In the 2008 Update, these links have been confirmed. The ARIA document is not intended to be a standard-of-care document for individual countries. It is provided as a basis for physicians, health care professionals and organizations involved in the treatment of allergic rhinitis and asthma in various countries to facilitate the development of relevant local standard-of-care documents for patients.

3,769 citations

Journal ArticleDOI
19 Feb 2020-Allergy
TL;DR: This work aims to investigate the clinical characteristic and allergy status of patients infected with SARS‐CoV‐2 and its spread around the world.
Abstract: Background Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been widely spread. We aim to investigate the clinical characteristic and allergy status of patients infected with SARS-CoV-2. Methods Electronic medical records including demographics, clinical manifestation, comorbidities, laboratory data, and radiological materials of 140 hospitalized COVID-19 patients, with confirmed result of SARS-CoV-2 viral infection, were extracted and analyzed. Results An approximately 1:1 ratio of male (50.7%) and female COVID-19 patients was found, with an overall median age of 57.0 years. All patients were community-acquired cases. Fever (91.7%), cough (75.0%), fatigue (75.0%), and gastrointestinal symptoms (39.6%) were the most common clinical manifestations, whereas hypertension (30.0%) and diabetes mellitus (12.1%) were the most common comorbidities. Drug hypersensitivity (11.4%) and urticaria (1.4%) were self-reported by several patients. Asthma or other allergic diseases were not reported by any of the patients. Chronic obstructive pulmonary disease (COPD, 1.4%) patients and current smokers (1.4%) were rare. Bilateral ground-glass or patchy opacity (89.6%) was the most common sign of radiological finding. Lymphopenia (75.4%) and eosinopenia (52.9%) were observed in most patients. Blood eosinophil counts correlate positively with lymphocyte counts in severe (r = .486, P Conclusion Detailed clinical investigation of 140 hospitalized COVID-19 cases suggests eosinopenia together with lymphopenia may be a potential indicator for diagnosis. Allergic diseases, asthma, and COPD are not risk factors for SARS-CoV-2 infection. Older age, high number of comorbidities, and more prominent laboratory abnormalities were associated with severe patients.

2,999 citations