The Experts below are selected from a list of 7941 Experts worldwide ranked by ideXlab platform
Sandra D Anderson - One of the best experts on this subject based on the ideXlab platform.
-
comparison of mannitol and methacholine to predict exercise induced bronchoconstriction and a clinical diagnosis of asthma
Respiratory Research, 2009Co-Authors: Sandra D Anderson, Sheldon L. Spector, John M. Weiler, Sara Nichols, David S PearlmanAbstract:Background Asthma can be difficult to diagnose, but Bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify Bronchial Hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated the sensitivity and specificity of mannitol to identify exercise-induced bronchoconstriction (EIB) as a manifestation of BHR; compared this with methacholine; and compared the sensitivity and specificity of mannitol and methacholine for a clinician diagnosis of asthma.
-
comparison of mannitol and methacholine to predict exercise induced bronchoconstriction and a clinical diagnosis of asthma
Respiratory Research, 2009Co-Authors: Sandra D Anderson, Sheldon L. Spector, John M. Weiler, Sara Nichols, Brett Charlton, David S PearlmanAbstract:Background Asthma can be difficult to diagnose, but Bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify Bronchial Hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated the sensitivity and specificity of mannitol to identify exercise-induced bronchoconstriction (EIB) as a manifestation of BHR; compared this with methacholine; and compared the sensitivity and specificity of mannitol and methacholine for a clinician diagnosis of asthma.
-
exercise induced asthma respiratory and allergic disorders in elite athletes epidemiology mechanisms and diagnosis part i of the report from the joint task force of the european respiratory society ers and the european academy of allergy and clinical immunology eaaci in cooperation with ga 2 len
Allergy, 2008Co-Authors: Kaihakon Carlsen, Sandra D Anderson, Leif Bjermer, S Bonini, Vito Brusasco, Walter Canonica, J Cummiskey, Luis Delgado, S R Del Giacco, F DrobnicAbstract:Aims: To analyze the changes in the prevalence of asthma, Bronchial Hyperresponsiveness (BHR) and allergies in elite athletes over the past years, to review the specific pathogenetic features of these conditions and to make recommendations for their diagnosis. Methods: The Task Force reviewed present literature by searching Medline up to November 2006 for relevant papers by the search words: asthma, Bronchial responsiveness, EIB, athletes and sports. Sign criteria were used to assess level of evidence and grades of recommendation. Results: The problems of sports-related asthma and allergy are outlined. Epidemiological evidence for an increased prevalence of asthma and BHR among competitive athletes, especially in endurance sports, is provided. The mechanisms for development of asthma and Bronchial Hyperresponsiveness in athletes are outlined. Criteria are given for the diagnosis of asthma and exercise induced asthma in the athlete. Conclusions: The prevalence of asthma and Bronchial Hyperresponsiveness is markedly increased in athletes, especially within endurance sports. Environmental factors often contribute. Recommendations for the diagnosis of asthma in athletes are outlined.
-
provocative challenges to help diagnose and monitor asthma exercise methacholine adenosine and mannitol
Current Opinion in Pulmonary Medicine, 2008Co-Authors: Sandra D AndersonAbstract:Purpose of review To review Bronchial provocations tests used in the measurement of Bronchial Hyperresponsiveness to help in the diagnosis of asthma. Recent findings The Bronchial provocations tests reviewed include exercise, methacholine, AMP and mannitol, with reference to methodology and monitoring of treatment. Summary Methacholine is used for identifying Bronchial Hyperresponsiveness and to guide treatment. Exercise is used as a Bronchial provocation test because demonstrating prevention of exercise-induced asthma is an indication for use of a drug. Both of these tests are being used to study tolerance to beta2 agonists. There is increasing use of eucapnic voluntary hyperpnea as a surrogate Bronchial provocation test for exercise to identify exercise-induced asthma, particularly in athletes. For methacholine and AMP there is concern about the different breathing patterns used to inhale these aerosols and the impact they have on the cutoff point for identifying Bronchial Hyperresponsiveness. A new test that uses a kit containing prepacked capsules of different doses of mannitol and a delivery device is discussed. There is increasing interest in using tests that act indirectly by release of mediators because the Bronchial Hyperresponsiveness itself is an indicator of the presence of inflammation. Since treatment of inflammation leads to loss of Bronchial Hyperresponsiveness to indirect stimuli, these tests are well suited to identify success of treatment.
Brian J Lipworth - One of the best experts on this subject based on the ideXlab platform.
-
Leukotriene C4 synthase polymorphisms and responsiveness to leukotriene antagonists in asthma
British journal of clinical pharmacology, 2003Co-Authors: Graeme P. Currie, John J. Lima, Jim E. Sylvester, Daniel K. C. Lee, Wendy Cockburn, Brian J LipworthAbstract:Aim Cysteinyl leukotrienes are important pro-inflammatory mediators in the pathogenesis of asthma, while leukotriene C4 synthase is a key enzyme in their biosynthesis. Our aim is to evaluate whether responsiveness to leukotriene receptor antagonists was determined by expression of the variant (C) or wild-type (A) polymorphism of this enzyme. Methods We carried out a retrospective analysis of 8 randomised, placebo-controlled trials performed in our department in mild-to-moderate asthmatics. In all trials, effect of leukotriene receptor antagonist was compared to placebo, where the primary outcome was Bronchial Hyperresponsiveness to adenosine monophosphate or methacholine. Secondary outcomes were forced expiratory volume in 1 second, exhaled nitric oxide and peripheral blood eosinophils. Results For the primary outcome of attenuation of Bronchial Hyperresponsiveness by leukotriene receptor antagonist vs placebo, there were significant effects within each genotype on adenosine monophosphate (AMP) (n = 78): 2.21 and 2.07-fold improvements for AA and AC/CC, respectively; while for methacholine (n = 81) there were 1.39 and 1.36-fold improvements, respectively. There were no significant differences between genotypes (i.e. AA vs AC/CC): geometric mean fold-differences of 1.07 (95%CI 0.63–1.81) and 1.02 (95%CI 0.70–1.50) for AMP and methacholine, respectively. There were also no differences between genotypes for all secondary outcomes. Conclusion Polymorphisms of leukotriene C4 synthase did not determine responsiveness, in terms of attenuation of Bronchial Hyperresponsiveness, to leukotriene receptor antagonists in mild-to-moderate asthmatics. Further prospective large pharmacogenetic studies are required in more severe patients, where there may be greater improvements in pharmacodynamic outcome measures such as Bronchial Hyperresponsiveness and exhaled nitric oxide.
-
screening for Bronchial Hyperresponsiveness using methacholine and adenosine monophosphate relationship to asthma severity and beta 2 receptor genotype
American Journal of Respiratory and Critical Care Medicine, 2000Co-Authors: Stephen J Fowler, Owen J Dempsey, Erika J Sims, Brian J LipworthAbstract:Bronchial Hyperresponsiveness (BHR) is a key feature of asthma and may be measured by direct methacholine challenge or indirect adenosine monophosphate (AMP) challenge. We performed a retrospective analysis of our database (n = 487) of patients with asthma with the aim first, to compare methacholine and AMP challenge as screening tools, and second, to identify any relationships between BHR and disease severity markers or beta(2)-adrenoceptor genotype. Of these subjects, 258 had a methacholine challenge, 259 an AMP challenge and 185 both. Of subjects having both, 140 (76%) were methacholine responsive with PD(20) < 500 microgram (PC(20) < 5 mg/ml) and 92 (50%) were AMP responsive with PC(20) < 200 mg/ ml. For those who were AMP unresponsive 57% were methacholine responsive, whereas for the methacholine nonresponders 11% were AMP responsive. Methacholine (but not AMP)-responsive patients had a significantly (p < 0.05) lower % predicted FEV(1) and FEF(25-75) and higher inhaled corticosteroid dose than unresponsive patients. Finally, subjects with a glycine allele at codon 16 had significantly (p < 0.05) increased BHR to methacholine but not AMP. Our results suggest that methacholine is a more appropriate screening tool for BHR than AMP as it was more sensitive in our population and was also related to asthma severity. In addition, we have demonstrated an association between the glycine allele (codon 16) and increased BHR to methacholine.
David S Pearlman - One of the best experts on this subject based on the ideXlab platform.
-
comparison of mannitol and methacholine to predict exercise induced bronchoconstriction and a clinical diagnosis of asthma
Respiratory Research, 2009Co-Authors: Sandra D Anderson, Sheldon L. Spector, John M. Weiler, Sara Nichols, David S PearlmanAbstract:Background Asthma can be difficult to diagnose, but Bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify Bronchial Hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated the sensitivity and specificity of mannitol to identify exercise-induced bronchoconstriction (EIB) as a manifestation of BHR; compared this with methacholine; and compared the sensitivity and specificity of mannitol and methacholine for a clinician diagnosis of asthma.
-
comparison of mannitol and methacholine to predict exercise induced bronchoconstriction and a clinical diagnosis of asthma
Respiratory Research, 2009Co-Authors: Sandra D Anderson, Sheldon L. Spector, John M. Weiler, Sara Nichols, Brett Charlton, David S PearlmanAbstract:Background Asthma can be difficult to diagnose, but Bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify Bronchial Hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated the sensitivity and specificity of mannitol to identify exercise-induced bronchoconstriction (EIB) as a manifestation of BHR; compared this with methacholine; and compared the sensitivity and specificity of mannitol and methacholine for a clinician diagnosis of asthma.
Soo-jong Hong - One of the best experts on this subject based on the ideXlab platform.
-
different cutoff values of methacholine Bronchial provocation test depending on age in children with asthma
World Journal of Pediatrics, 2017Co-Authors: Eun Lee, Song-i Yang, Soyeon Lee, Hyo Bin Kim, Youngho Kim, Seungbong Han, Young Ho Jung, Ju Hee Seo, Ji Won Kwon, Soo-jong HongAbstract:Background Bronchial Hyperresponsiveness (BHR) is a fundamental pathophysiological characteristic of asthma. Although several factors such as airway caliber can affect BHR, no study has established age-dependent cutoff values of BHR to methacholine for the diagnosis of asthma in children. We investigated the cutoff values of the methacholine challenge test (MCT) in the diagnosis of asthma according to age.
-
Association of symptom control with changes in lung function, Bronchial Hyperresponsiveness, and exhaled nitric oxide after inhaled corticosteroid treatment in children with asthma
Elsevier, 2016Co-Authors: Geun-mi Park, Hye Won Han, Jae Youn Kim, Eun Lee, Hyun-ju Cho, Jisun Yoon, Soo-jong Hong, Song-i Yang, Hyeon-jong YangAbstract:Background: A key therapeutic approach to asthma, which is characterized by chronic airway inflammation, is inhaled corticosteroid (ICS). This study evaluated the association of symptom control with changes in lung function, Bronchial Hyperresponsiveness (BHR), and exhaled nitric oxide (eNO) after ICS treatment in asthmatic children. Methods: A total of 33 children aged between 5 and 12 years with mild to moderate persistent asthma were treated with 160 μg ciclesonide per day for 3 months. At days 0 and 90, the following parameters were assessed: asthma symptom scores; lung function, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and forced expiratory flow at 25–75% of forced vital capacity (FEF25–75%); BHR to methacholine and adenosine 5-monophosphate (AMP); and eNO. Results: Asthma symptom scores, lung function parameters, BHR to methacholine and AMP, and eNO levels at day 90 were significantly improved versus day 0 (all p
-
association of il 13 polymorphisms with leukotriene receptor antagonist drug responsiveness in korean children with exercise induced bronchoconstriction
Pharmacogenetics and Genomics, 2008Co-Authors: Mijin Kang, Soyeon Lee, Hyo Bin Kim, Byoungju Kim, Wonah Choi, S Jang, Soo-jong HongAbstract:BackgroundIL-13 is a pivotal cytokine in allergic inflammation and Bronchial Hyperresponsiveness, and is known to influence leukotriene levels.ObjectiveWe investigated whether IL-13 polymorphisms may be associated with clinical phenotypes and drug responsiveness to the leukotriene receptor antagonis
Peter Bradding - One of the best experts on this subject based on the ideXlab platform.
-
mannitol and amp do not induce bronchoconstriction in eosinophilic bronchitis further evidence for dissociation between airway inflammation and Bronchial Hyperresponsiveness
Respirology, 2010Co-Authors: Amisha Singapuri, Christopher E Brightling, Sue Mckenna, Peter BraddingAbstract:Background and objective: Eosinophilic bronchitis (EB) shares many pathological features with asthma. However, patients with EB do not develop the characteristic physiological abnormalities of asthma: variable airflow obstruction and Bronchial Hyperresponsiveness (BHR) to a direct Bronchial challenge with methacholine. Indirect Bronchial challenges with AMP and mannitol are dependent on the presence of airway inflammation, and positive in 10% of asthmatic subjects who have a negative response to methacholine. We have therefore investigated whether subjects with EB are responsive to indirect airway challenge with AMP and mannitol. Methods: Subjects with asthma, EB and healthy controls attended on up to four occasions. After screening, subjects performed Bronchial provocation tests to methacholine and then either AMP or mannitol. Each challenge was followed immediately by sputum induction for the measurement of airway inflammation and mast cell-derived histamine. Results: No subjects with EB responded to either AMP (n = 5) or mannitol (n = 7) while 4/8 and 7/10 subjects with asthma responded to the respective challenges (P = 0.057 for AMP, P = 0.004 for mannitol). There was no difference in induced sputum concentrations of histamine or eosinophil cell counts following methacholine challenge compared with AMP or mannitol. Conclusions: The airways of patients with EB are not responsive to either direct or indirect Bronchial challenge. This supports the view that it is the presence of functionally abnormal airway smooth muscle that is the key determinant of BHR in asthma, and that while this may be aggravated by the presence of mucosal airway inflammation, it is not caused by it.
-
the role of the mast cell in the pathophysiology of asthma
The Journal of Allergy and Clinical Immunology, 2006Co-Authors: Peter Bradding, Andrew F Walls, Stephen T HolgateAbstract:There is compelling evidence that human mast cells contribute to the pathophysiology of asthma. Mast cells, but not T cells or eosinophils, localize within the Bronchial smooth muscle bundles in patients with asthma but not in normal subjects or those with eosinophilic bronchitis, a factor likely to be important in determining the asthmatic phenotype. The mechanism of mast cell recruitment by asthmatic airway smooth muscle involves the CXCL10/CXCR3 axis, and several mast cell mediators have profound effects on airway smooth muscle function. The autacoids are established as potent bronchoconstrictors, whereas the proteases tryptase and chymase are being demonstrated to have a range of actions consistent with key roles in inflammation, tissue remodeling, and Bronchial Hyperresponsiveness. IL-4 and IL-13, known mast cell products, also induce Bronchial Hyperresponsiveness in the mouse independent of the inflammatory response and enhance the magnitude of agonist-induced intracellular Ca2+ responses in cultured human airway smooth muscle. There are therefore many pathways by which the close approximation of mast cells with airway smooth muscle cells might lead to disordered airway smooth muscle function. Mast cells also infiltrate the airway mucous glands in subjects with asthma, showing features of degranulation, and a positive correlation with the degree of mucus obstructing the airway lumen, suggesting that mast cells play an important role in regulating mucous gland secretion. The development of potent and specific inhibitors of mast cell secretion, which remain active when administered long-term to asthmatic airways, should offer a novel approach to the treatment of asthma.
