Search results for "Bronchoconstriction"
showing 10 items of 47 documents
Effect of cigarette smoking on airway responsiveness to adenosine 5'-monophosphate in subjects with allergic rhinitis.
2003
Study objectives: The objective of this study was to determine differences in airway responsiveness to adenosine 5-monophosphate (AMP) between smokers and nonsmokers with allergic rhinitis. Methods: A total of 41 adults with allergic rhinitis (16 smokers and 25 nonsmokers) were challenged with increasing concentrations of methacholine and AMP. Airflow was assessed after each concentration, and the response to each bronchoconstrictor agent was measured by the provocative concentration required to produce a 20% fall in FEV1 (PC20). Results: The geometric mean PC20 AMP values were significantly lower in smokers than in nonsmokers: 72.4 mg/mL (95% confidence interval [CI], 33.9 to 154.9) vs 204…
Relationship between airway sensitivity to adenosine 5' monophosphate and the shape of the concentration-response curve to methacholine in subjects w…
2001
Abstract The objective of this study was to determine differences in airway sensitivity to adenosine 5′-monophosphate (AMP) between allergic rhinitis subjects with plateau and those without evidence of plateau on the concentration–response curves to methacholine. A total of 51 adults (38 subjects with allergic rhinitis and 13 healthy controls) were challenged with increasing concentrations of methacholine and AMP. The methacholine challenge was terminated when there was a 40% or more decrease in forced expiratory volume in 1 sec (FEV 1 ), whereas the AMP challenge was stopped when FEV 1 had fallen by more than 20%. A plateau for methacholine was detected in all 13 healthy controls and in 27…
Effect of beclomethasone dipropionate on the bronchial responsiveness to propranolol in asthmatics.
1990
The effect of four weeks of treatment with beclomethasone dipropionate (BDP, 500 micrograms twice daily) on the bronchial responsiveness to propranolol was examined in 16 patients with mild asthma in a placebo-controlled, double-blind crossover study. Propranolol was inhaled in doubling concentrations and the results were expressed as the cumulative dose producing a 20 percent fall in FEV1 (PC20). After four weeks of treatment with BDP, the mean FEV1 increased from 82.0 percent predicted to 88.1 percent predicted. The difference was significant (p less than 0.001). Treatment with BDP did not significantly change the responsiveness to propranolol, the geometric mean PC20 being 3.17 mg/ml bef…
Anti-muscarinic drugs as preventive treatment of exercise-induced bronchoconstriction (EIB) in children and adults.
2020
Regular physical activity is strongly recommended to prevent chronic respiratory diseases, including asthma. On the other hand, vigorous physical training may trigger airway symptoms and bronchoconstriction. The transient airway narrowing occurring because of exercise is named exercise-induced bronchoconstriction (EIB). Despite management according to guidelines, a significant proportion of patients experiences uncontrolled EIB, which thus represents a relevant unmet medical need. In particular, although prevention and treatment of EIB are effectively based on the use of beta-2 bronchodilator drugs, high heterogeneity in individual responses has been reported. Furthermore, even though beta-…
Modifications of airway responsiveness to adenosine 5'-monophosphate and exhaled nitric oxide concentrations after the pollen season in subjects with…
2002
s: To determine the effect of cessation of exposure to pollen on airway responsiveness to adenosine 5'-monophosphate (AMP) in subjects with pollen-induced rhinitis, and to explore the relationship between changes in airway responsiveness and changes in exhaled nitric oxide (ENO) levels.Subjects were studied during the pollen season and out of season.Specialist allergy unit in a university hospital.Fourteen subjects without asthma with pollen-induced rhinitis who showed bronchoconstriction in response to methacholine and AMP during the pollen season and 10 healthy nonatopic control subjects.In subjects with pollen-induced rhinitis, ENO concentrations, provocative concentration of agonist cau…
Modifications in forced vital capacity during adenosine monophosphate-induced bronchoconstriction in asthma: relationship with the response to methac…
2009
Background The effect of adenosine monophosphate (AMP) on forced vital capacity (FVC) has never been systematically investigated. Objective To compare methacholine- and AMP-induced changes in FVC, as a marker of air trapping, in asthmatic patients treated and not treated with inhaled corticosteroids (ICSs). Methods Airway responsiveness to equipotent concentrations of AMP and methacholine was obtained in asthmatic patients treated (n = 32) and not treated (n = 18) with ICSs. The response was expressed by the provocation concentration of agonist that caused a decrease in forced expiratory volume in 1 second (FEV 1 ) of 20% (PC 20 ) and by the slope of the FVC values recorded at each step of …
The role of lung inflation in airway hyperresponsiveness and in asthma
2004
Airway hyperresponsiveness (AHR) is a fundamental phenomenon in asthma that can explain many aspects of the clinical manifestations of the disease. Several theories on the mechanisms of AHR have been proposed, but the true nature of this problem is yet to be defined. During the past decade, the role of lung inflation in airway physiology and its relationship to AHR have attracted major attention. Deep inspirations are known to exert strong beneficial effects on the airways of healthy humans. These effects appear to be of dual nature: bronchoprotective and bronchodilatory. The bronchoprotective effect of deep inspiration is lost in asthma, even in mild disease. It is also lost in individuals…
Zur Immunpathogenese des Asthma bronchiale
2000
Allergic asthma is a chronic pulmonary disease associated with bronchoconstriction and inflammation. Recent studies have shown that mediator substances and proinflammatory cytokines produced by mast cells, eosinophils and T-lymphocytes appear to be important for the pathogenesis of asthma. These substances contribute both to the initiation and perpetuation of the disease. In particular, it has been shown that allergic asthma is associated with increased TH2 (IL-4, IL-5, IL-13) cytokine production that causes activation of eosinophils and T-cells and production of chemokines (e.g. eotaxin) by pulmonary fibroblasts. Based on recent advances in our understanding of the immunopathogenesis of as…
Airway Responsiveness to Adenosine 5′-Monophosphate and Exhaled Nitric Oxide Measurements
2003
Objectives To investigate the utility of the determination of airway responsiveness to inhaled adenosine 5′-monophosphate (AMP) and exhaled nitric oxide (ENO) levels as markers for safely reducing the dose of inhaled corticosteroids (ICS) in patients with asthma well controlled with a moderately high ICS dose. Methods A total of 37 patients with asthma well controlled for at least 3 months by treatment with a moderately high ICS dose (beclomethasone dipropionate, 500 to 1,000 μg or equivalent daily) were included in the study. Patients were treated for a 2-week run-in (baseline) period with their usual dose of ICS. For the next 12 weeks, patients were treated with ICS at half the previous d…
[Evolution over time in over perceivers of dyspnea in asthma].
2006
OBJECTIVE: In previous studies we identified a subgroup of patients whose perception of breathlessness was exaggerated during acute bronchoconstriction and who were termed “over perceivers” or “hyperperceivers.” In this study we aimed to determine whether such over perception is sporadic or stable over time. We also examined whether there is an association between over perception of dyspnea and hyperventilation syndrome. PATIENTS AND METHODS: The subjects were 22 stable asthmatics (11 men, 11 women) who had been over perceivers of dyspnea in a study 9 years earlier. After a medical history was taken, a patient performed forced spirometry and a severity classification was made according to t…