Search results for "bronchial hyperreactivity"
showing 10 items of 53 documents
Increased responsiveness of human pulmonary arteries in patients with positive bronchodilator response.
1996
Abstract 1. The effects of noradrenaline, endothelin-1, acetylcholine and sodium nitroprusside were studied in isolated pulmonary arteries obtained from 14 patients undergoing lobectomy for lung carcinoma. Seven patients had shown increased response to a bronchodilator test prior to operation. In the remaining patients (control) the bronchodilator test was negative. 2. Artery rings from patients with a positive bronchodilator response showed greater contraction to noradrenaline (pD2 = 6.44 +/- 0.1; Emax = 93 +/- 9% of response to 100 mM KCl) and endothelin-1 (pD2 = 8.92 +/- 0.1; Emax = 130 +/- 16%) than the rings from control patients (pD2 = 6.04 +/- 0.08; Emax = 56 +/- 8% for noradrenaline…
Increased airway inflammatory cells in endurance athletes: what do they mean?
2003
Inflammatory cells are increased in the airways of endurance athletes, but their role in causing exercise-induced respiratory symptoms and bronchoconstriction, or their possible long-term consequences, are uncertain.To put the results of athlete studies in perspective, by analysing the pathogenesis of airway cell changes and their impact on respiratory function.Athletes of different endurance sports at rest showed increased airway neutrophils. Elite swimmers and skiers also showed large increases in airway eosinophils and lymphocytes, possibly related to chronic, exercise-related exposure to irritants or cold and dry air, respectively. Post-exercise studies reported variable responses of ai…
Involvement of distal airways in a chronic model of experimental asthma.
2005
Summary Background Bronchial asthma is characterized by chronic airway inflammation and airway remodelling which occurs in both proximal and distal airways. These changes are associated with development of airway hyper-responsiveness and airflow limitation. Objective This study was aimed to analyse whether chronic inhalative allergen challenges in mice lead to morphological and physiological changes comparable with this phenotype. Methods For this purpose, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed by aerosol allergen challenges on 2 consecutive days per week for 12 weeks. Results In chronically challenged mice, tissue inflammation in proximal as well as distal air…
Airway hyperresponsiveness in the elderly: prevalence and clinical implications.
2005
Airway hyperresponsiveness is associated with an increased risk of developing respiratory symptoms. The assessment of airway hyperresponsiveness can provide valuable information regarding the natural course of respiratory diseases. However, little information is available for populations of more advanced age, and data are conflicting. It was assessed whether age influences the occurrence of airway hyperresponsiveness by reviewing those studies that specifically addressed this issue, and attempting to identify the factors responsible for discrepancies between studies. Eighteen studies, published between 1983 and 2002, are included in this review. Overall, the results of the analysis are in f…
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…
Cellular network in airways inflammation and remodelling
2002
Chronic inflammation and airway remodelling are two key steps in asthma pathophysiology. The development of chronic airway inflammation depends upon the continuous recruitment of inflammatory cells from the bloodstream towards the bronchial mucosa and by their subsequent functional activation. The release of inflammatory mediators by activated cells contributes to the generation of a complex network which involves mobile inflammatory cells and structural cells such as epithelial cells, fibroblasts and myofibroblasts. This network is responsible for the amplification and persistence of the inflammatory process as well as for the development of a peculiar microenvironment which can directly m…
Prevalence of nocturnal asthma in a general population sample: determinants and effect of aging.
2000
Nocturnal asthma (NA) is important because of clinical and prognostic implications. Previous data on prevalence may be overestimated, because they are derived from selected series. Observations on monitoring of peak expiratory flow in elderly asthmatics suggested that prevalence of NA may increase with age. This study was designed to estimate the prevalence of NA-related symptoms in a sample drawn from a general population and evaluate the role of aging. Subjects (1,100, mean age 41.9, SD 22.8 years) were randomly selected from the lists of seven general practitioners. A questionnaire on nighttime and morning NA-associated symptoms was used and frequency of occurrence was rated as never, so…
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…
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…
Mast cell-derived tumour necrosis factor is essential for allergic airway disease
2007
Mast cells are thought to contribute to allergic airway disease. However, the role of mast cell-produced mediators, such as tumour necrosis factor (TNF), for the development of allergic airway disease is unclear. In order to define the role of mast cells in acute allergic airway disease two strains of mast cell-deficient mice (Kit W/Wv and Kit W-sh/W-sh ) were studied. Compared with their wild-type littermates, Kit W/Wv and Kit W-sh/W-sh mice developed significantly lower airway responsiveness to methacholine and less airway inflammation and goblet cell metaplasia, following sensitisation in the absence of adjuvant and airway challenge. Transfer of bone marrow-derived mast cells (BMMCs) fro…