According to the most recent definition, bronchial asthma is a chronic inflammatory disorder of the airways associated with reversible airway obstruction and increased airway responsiveness to a variety of stimuli. An intuitive inference from this definition is that a causal relationship may exist between airway inflammation and airway hyperresponsiveness. Along this line of reasoning, most of ...

Chronic stable asthma is characterized by inflammation of the airway wall, with abnormal accumulation of basophils, eosinophils, lymphocytes, mast cells, macrophages, dendritic cells, and myofibroblasts. Airway inflammation is not limited to severe asthma, but is also found in mild and moderate asthma. This inflammation results in a peculiar type of lymphocytic infiltration whereby Th2 lymphocy...

In recent years, airway responsiveness has commonly been measured in epidemiological studies using one of two methods. In one method, histamine is administered via a handheld DeVilbiss nebulizer and in the other, methacholine is administered via a dosimeter. Allergic sensitivity has commonly been measured by either the allergen droplet method or by Phazet. We wanted to assess the comparability ...

BACKGROUND The airway muscles from allergen-sensitized animals in vitro show a heightened response to histamine, but not to carbachol. This study investigated whether the airway responsiveness to histamine in vivo is comparable to that of methacholine in human subjects with varying degrees of atopy. METHODS One-hundred-and-sixty-eight consecutive adult asthma patients or volunteers underwent ...

inhalational insulin was withdrawn from the market due to its potential to produce airway hyper-reactivity and bronchoconstriction. so the present study was designed to explore the acute effects of insulin on airway reactivity of guinea pigs and protective effects of salbutamol and beclomethasone against insulin induced airway hyper-responsiveness on isolated tracheal smooth muscle of guinea pi...

Increased airway responsiveness (AR) is associated with asthma, but not all individuals with increased AR have asthma. The aim of this study was to identify factors, other than physician-diagnosed asthma (PDA), which are associated with increased AR. In a longitudinal study, data were collected on atopy and lower respiratory tract illness (LRTI) in infancy, and AR (expressed as dose-response sl...

STUDY OBJECTIVES To assess whether the dual anatomic origin of exhaled nitric oxide (NO), namely alveolar and bronchial, could explain the link between exhaled NO and airway responsiveness, and could participate in the bronchodilatory effect of deep inspiration (DI) that may be evidenced during methacholine challenge. DESIGN AND SETTING Prospective study in a laboratory performing pulmonary f...

The mechanisms by which deep inspiration (DI) avoidance increases airway responsiveness in healthy subjects are not known. DI avoidance does not alter respiratory mechanics directly; however, computational modeling has predicted that DI avoidance would increase baseline ventilation heterogeneity. The aim was to determine if DI avoidance increased baseline ventilation heterogeneity and whether t...

BACKGROUND Allergen induced early phase airway response and airway plasma exudation are predominantly mediated by inflammatory mast cell mediators including histamine, cysteinyl leukotrienes (cysLTs) and thromboxane A2 (TXA2). The aim of the present study was to evaluate whether repeated allergen exposure affects early phase airway response to allergen challenge. METHODS A trimellitic anhydri...