Search results for "choline"
showing 10 items of 1138 documents
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…
Effects of cigarette smoke on methacholine- and AMP-induced air trapping in asthmatics.
2014
Abstract Objective: No information is available on the effect of cigarette smoke on bronchoconstrictor-induced air trapping in asthma. The aim of this study was to evaluate the additional influence of smoking on methacholine- and adenosine 5'-monophosphate (AMP)-induced air trapping in subjects with asthma.Airway responsiveness to methacholine and AMP, bronchial (J'awNO) and alveolar (CANO) nitric oxide (NO) and exhaled breath condensate pH were measured in 68 adults (23 current smokers with asthma, 23 non-smokers with asthma and 22 current or former smokers with chronic obstructive pulmonary disease; COPD). The degree of air trapping induced by each bronchoconstrictor agent was expressed b…
Smoking and Obesity Increase Airway Hyperesponsiveness Risk In the Elderly
2015
Objective of our study was assessing whether smoking and obesity might affect airways hyperresponsiveness (AHR) differently in younger and older subjects and whether this influence might be due to their different impacts on baseline lung function values at different ages. Methods 3,903 consecutive adult subjects with normal lung function (1,920 males; mean age 35.1±16.2; median FEV1:97.3% of predicted [interquartile range (IQR):89.7-105.2] and FEV1/FVC:84.6% of predicted [IQR:79.8-89.2]), having performed a methacholine test, were considered. They were subdivided into three groups according to age (18-39, 40-64 and ≥65 years) and into different sub-groups according to body mass index (BMI) …
The bronchodilatory effect of deep inspiration diminishes with aging
2004
AbstractDeep inspirations have the ability to dilate constricted airways. The impairment of this function has been associated with the occurrence of asthmatic symptoms. We evaluated whether the bronchodilatory effect of deep inspiration (DI) is affected by aging. We tested 25 healthy subjects (median age: 54 yrs, range: 25–83 yrs). Single dose methacholine (Mch) provocations were performed in the absence of DI, which induced at least 15% reduction in inspiratory vital capacity (IVC) from baseline. The post-Mch IVC measurement was followed by 4 DIs and by another IVC (post-DI IVC). The fractional difference between post-DI IVC and post-Mch IVC represented the % bronchodilation by DI. The % b…
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 …
Tiotropium - ein langwirksames, inhalatives Anticholinergikum zur Therapie der chronisch-obstruktiven Lungenerkrankung (COPD)
2003
Anticholinergics are agents of first choice for the symptomatic treatment of patients with COPD. Tiotropium (Ba 679 BR, Spiriva) is a long-acting inhaled anticholinergic designed for once-daily bronchodilator treatment of COPD. Tiotropium is a selective antagonist of pulmonary M1 and M3 muscarinic receptor subtypes, that produces a long-lasting (24 hours), dose-dependent bronchodilation and bronchoprotection against constrictive stimuli, e. g. methacholine, following inhalation of single doses. Clinical trials with tiotropium in COPD patients over a maximum treatment duration of one year have confirmed a persisting bronchodilator effect of tiotropium compared with placebo and ipratropium, a…
Differences in the Response to Methacholine Between the Tidal Breathing and Dosimeter Methods
2008
Background It has been postulated that differences in provocative concentration of methacholine causing a 20% fall in FEV 1 (PC 20 ) values between the dosimeter method and tidal breathing method might be due to differences in the dose of agonist delivered to the mouth. The aim of the present study was to determine the influence of the dose of aerosol delivered to the mouth on differences in the response obtained with each challenge method. Methods This study measured airway responsiveness to methacholine by dosimeter method and tidal breathing method in 27 subjects with suspected asthma. The dosimeter was modified to deliver an identical volume to that obtained with the tidal breathing met…
Future Directions in the Pharmacologic Therapy of Chronic Obstructive Pulmonary Disease
2005
Current therapy for chronic obstructive pulmonary disease (COPD) fails to alter its relentless progression. This remains a significant challenge and unmet need. A recent advance is the demonstration that treatment with a fixed dose of an inhaled corticosteroid and a long-acting beta2-agonist in COPD improves lung function and quality of life, and reduces exacerbation more effectively than either drug alone. Other improvements include the introduction of tiotropium, a once-daily anticholinergic. In advanced clinical development are other once-daily bronchodilators and combinations of anticholinergic drugs and beta2-agonists. Increased understanding of the pathogenesis of COPD has led to nove…
The Non-neuronal cholinergic system: an emerging drug target in the airways.
2001
The non-neuronal cholinergic system is widely expressed in human airways. Choline acetyltransferase (ChAT) and/or acetylcholine are demonstrated in more or less all epithelial surface cells (goblet cells, ciliated cells, basal cells), submucosal glands and airway smooth muscle fibres. Acetylcholine is also demonstrated in the effector cells of the immune system (lymphocytes, macrophages, mast cells). Epithelial, endothelial and immune cells express nicotinic and muscarinic receptors. Thus the cytomolecule acetylcholine can contribute to the regulation of basic cell functions via auto-/paracrine mechanisms (proliferation, differentiation, ciliary activity, secretion of water, ions and mucus,…