0000000000041224
AUTHOR
Victoria Lopez
showing 7 related works from this author
Maximal degree of airway narrowing induced by methacholine and adenosine monophosphate: relationship with the decrease in forced vital capacity.
2010
Background Changes in forced vital capacity (FVC) may represent an indirect method for the detection of plateau in response to inhaled bronchoconstrictor agents. Objective To determine the relationship between the level of plateau obtained with either methacholine or adenosine monophosphate (AMP) and the decrease in FVC induced by each bronchoconstrictor agent. Methods Airway responsiveness to high concentrations of methacholine and AMP was determined in patients with intermittent asthma (n = 41) or allergic rhinitis (n = 26). Furthermore, allergen-induced changes in the response to each bronchoconstrictor agent were investigated in 18 pollen-sensitive patients. Concentration-response curve…
Maximal Response Plateau to Adenosine 5′-Monophosphate in Asthma
2009
Background No information is available on the plateau in response to adenosine 5′-monophosphate. The aims of the present study were to determine whether plateau can be detected with AMP and the relation with the plateau in response to methacholine, and to identify the relation between the plateau and indirect markers of airway inflammation, such as exhaled nitric oxide (ENO) and exhaled breath condensate (EBC) pH. Methods Airway responsiveness to high concentrations of methacholine and AMP, ENO levels, and EBC pH values were obtained in 31 subjects with well-controlled asthma. Concentration-response curves were characterized by their concentration of agonist that produces a decrease in FEV …
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…
Effects of allergen exposure on methacholine and AMP-induced air trapping in pollen-sensitive subjects
2011
Summary Background The effect of pro-inflammatory stimuli on bronchoconstrictor-induced air trapping has not been studied. Objective To determine the effect of natural allergen exposure, a pro-inflammatory stimulus, on methacholine- and adenosine 5′-monophospate (AMP)-induced air trapping. Methods Airway responsiveness to methacholine and AMP before and during the pollen season was obtained in 25 subjects with pollen allergy and in 10 healthy controls. The response was expressed by the sensitivity (PC 20 value) and by the slope and intercept of the FVC values recorded at each step of the challenge against the corresponding FEV 1 values. Results The slope and intercept FVC versus FEV 1 value…
Effect of allergen-specific immunotherapy with purified Alt a1 on AMP responsiveness, exhaled nitric oxide and exhaled breath condensate pH: a random…
2010
Abstract Background Little information is available on the effect of allergen-specific immunotherapy on airway responsiveness and markers in exhaled air. The aims of this study were to assess the safety of immunotherapy with purified natural Alt a1 and its effect on airway responsiveness to direct and indirect bronchoconstrictor agents and markers in exhaled air. Methods This was a randomized double-blind trial. Subjects with allergic rhinitis with or without mild/moderate asthma sensitized to A alternata and who also had a positive skin prick test to Alt a1 were randomized to treatment with placebo (n = 18) or purified natural Alt a1 (n = 22) subcutaneously for 12 months. Bronchial respons…
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 effect of challenge method on methacholine-induced changes in sensitivity and air trapping
2010
Summary Background The methacholine challenge test performed with the tidal breathing method induces a greater fall in FEV 1 than the dosimeter method; however, the effect of the challenge method on methacholine-induced fall in FVC has not been investigated. Objective To determine the influence of the challenge method on methacholine-induced changes in FEV 1 and FVC. Methods Airway responsiveness to methacholine was determined by dosimeter method and tidal breathing method in 37 subjects with suspected asthma. The dosimeter was modified to deliver an identical volume to that obtained with the tidal breathing method and the same nebulizer model was used for the two challenges. The response w…