الفهرس 
classi fication of asthmaOnly 14 pages are availabe for public view
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Abstract
Bronchial asthma is one of the most common chronic diseases. It’s a chronic inflammatory disease of the airways characterized by reversible airway obstruction, inflammation, and hyperresponsiveness to variety of stimuli. Inflammation is being increasingly recognized as a major factor in the pathogenesis of asthma, and a driving force in airway hyperresponsiveness. Cells which are mainly responsible for this inflammation are eosinophils, mast cells, and CD4+T helper 2 lymphocytes. Bronchial hyperresponsiveness (BHR) has often been linked to airways inflammation. It’s an exaggerated bronchoconstrictive response of the airways to various inhaled stimuli. It can be measured by using bronchoconstrictives as histamine and methacholine, by determining the provocative concentration or dose causing 20% fall in forced expiratory volume in the first second (FEVi). Many drugs have proved useful for treatment of asthma including drugs which are used as bronchodilators in acute attacks, and others which can suppress the chronic and persistent airway inflammation. It’s important to find markers of inflammation that’s simple to measure, inexpensive and non invasive to help in evaluating the effect of these anti-asthmatic drugs. Measurement of BHR may also help in this evaluation.