Bronchial hyper-responsiveness

Asthma is a chronic inflammatory condition characterized by bronchial hyper-responsiveness and reversible airway obstruction. Cytokine release from a variety of cell types such as eosinophils, lymphocytes and other inflammatory cells produces epithelial sloughing, plasma protein extravasation from the tracheobronchial microcirculation and airway remodeling. Bronchial mucosal inflammation is present in all patients. The primary goal of asthma management is to maintain control of the disease process by reducing symptoms and improving lung function. 

Allen, M.C., Graham, P., Morris, G., 1996. Histamine forming capacity (HFC) and its modulation by H3 receptor ligands in a model of bronchial hyper-responsiveness. Inflamm. Res. 45, 118-122. 

A missense mutation (Glu237Gly) of the P-subunit of the receptor creates a receptor associated with bronchial hyper-responsiveness. The mechanism of this response is not clear (39,127,128)... 

Hill MR, Cookson WO. A new variant of the beta subunit of the high-affinity receptor for immunoglobulin E (Fc epsilon Rl-beta E237G) associations with measures of atopy and bronchial hyper-responsiveness. Hum Mol Genet 1996 5(7) 959-962. 

Postma DS, Bleecker ER, Amelung PJ, et al Genetic susceptibility to asthma - Bronchial hyper-responsiveness coinherited with a major gene for atopy. N Engl J Med 1995 333 894-900. (Ill)... 

Bronchial hyper responsiveness and asduna Asdnna and allergic rhinitis... 

Respiratory When 21 patients who had been sensitized to isoeugenol or hydroxyisohexyl-3-carboxaldehyde inhaled these fragrances and geraniol as a control, there was increased bronchial hyper-responsiveness but no significant changes in lung function [37. ... 

Theophylline s predominant mode of action appears to be bronchocHlation. However, it has also been shown that prophylactic acHriinistration of theophylline provides some protection from asthma attacks and suppresses the late-phase response (67,68). Some researchers beHeve that at therapeutic semm concentrations theophylline may inhibit the development of airway inflammation (69). There are conflicting reports on the effect of theophylline on allergen-induced bronchial hyperresponsiveness some clinical stucHes report a reduction in hyper-responsiveness, others do not (69,70). Theophylline clearly does not reverse the general bronchial hyperresponsiveness over the course of long-term therapy (71). Because of the relationship between... 

Selectins mediate contact by binding to carbohydrate-containing receptors on leucocytes through their N-terminal lectin domain. Sialyl-Lewis X (Neu5Aca2-3-Gaipi-4(Fucal-3)Glc-NAc) and derivatives thereof were shown to bind to the selectins and subsequently inhibit ischaemia-induced leucocyte infiltration in the liver [76-78]. A similar compound prevented antigen-induced late bronchial responses and airway hyper-responsiveness in allergic sheep [79]. 

Corticosteroids are anti-inflammatory drugs that can be used in asthma to reduce airway hyper-responsiveness and to decrease bronchial oedema and mucus secretion. They are effective in the late phase reaction and reduce the intensity of allergic reactions. They are used in emergency treatment of severe acute attacks, for the treatment of mild to moderate attacks and prophylactically to prevent attacks. Corticosteroids can be useful in reducing acute exacerbations of chronic bronchitis. 

Hypersensitivity to the irritant effects of inhaled sulfur dioxide is well recognized and is a usual feature of asthma. As little as 1.0 ppm of the inhaled gas can produce significant broncho-constriction in groups of asthmatics (Koenig et ai, 1980 Koenig et ai, 1982), and the symptomatic severity of asthma can be correlated with atmospheric SO2 pollution (Boushey, 1982). Hypersensitivity appears to be due to an exaggerated reflex response to chemical irritation on the background of the bronchial hyper-reactivity which characterizes the asthmatic state (Boushey, 1982). 

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