ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

A small effect (approximately 1 cm) of inhaled and intranasal corticosteroids on the 1 year growth of children with asthma and allergic rhinitis, respectively, has been reported in studies published during the past 10 years. Literature published during the past year confirmed the effect, but provided additional and novel information on the effects of longer-term (over 1 year) treatment, particularly with inhaled corticosteroids. This information is timely, because the longer-term effect size and duration were previously unknown, and the findings have major implications for the content of the safety discussion between caregivers and the parents of children with asthma or allergic rhinitis. The results of these studies provide very reassuring information about the longer-term safety of the use of inhaled corticosteroids in children with asthma. Limited evidence has also supported the notion that intranasal corticosteroids have no longer-term effects on growth. The possibility of an idiosyncratic (versus global) effect received conflicting support in recent literature. The risk of growth retardation can be lessened and managed by the employment of several simple strategies: (i) monitor growth; (ii) use minimal effective dose; and (iii) optimize steroid-sparing strategies. Communication with patients/parents about this possible side-effect, as well as the adverse consequences of the non-use of inhaled and intranasal corticosteroids, is essential to minimize any possible negative impact on adherence. Children whose disease severity warrants inhaled or intranasal corticosteroid therapy should not be denied their benefits on the basis of this safety consideration.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Stimulation of the nasal sensory nerves leads to sensations of pain and stuffiness. Type C nociceptive nerve releases neuropeptides including substance P and calcitonin gene related peptides that increase plasma extravasation and glandular secretion. This axonal response acts as an immediate protective mucosal defense mechanism. Recruited parasympathetic reflexes cause submucosal gland secretion via acetylcholine and muscarinic M3receptors. Itching, sneezing, and other avoidance behaviors rapidly clear the offending agents from the upper airways and protect the lower airways. Dysfunction of these nerves may contribute to allergic rhinitis, infectious rhinitis, nasal hyperresponsiveness, and possibly sinusitis. Sympathetic arterial vasoconstriction reduces mucosal blood flow, sinusoidal filling, and mucosal thickness, and so restores nasal patency. Loss of sympathetic tone may contribute to some chronic, nonallergic rhinopathies. Human axon responses differ from those in animals, an important distinction that limits extrapolation from other species.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Past studies implicated allergy in the pathogenesis of otitis media. However, definitive proof of the assertion is lacking. Epidemiologic studies, including one recently published by Rylander and Megevand, consistently identify allergy as a risk factor for otitis media. Also, higher than expected frequencies of allergy are reported for patients with otitis media, but it is unclear if this is an epiphenomenon associated with referral bias. This possibility is exemplified by the results of two reviewed papers where Velepic and colleagues reported a 25% prevalence of allergy in otitis media patients while Alles and colleagues reported a prevalence of 89%. Other studies documented biochemical components of allergic inflammation in the effusions recovered from children with otitis media, and Hurst and colleagues published a recent paper continuing on that theme. However, it is not known if a local allergic reaction is required for the production of these components and if they are produced exclusive of other inflammatory products. Three published studies explored mechanisms by which allergy could cause otitis media. Tikkanen and colleagues reexamined at age 10 a group of 56 subjects with previously diagnosed milk allergy and showed that despite decreased reactivity to milk protein a high prevalence of otitis media was retained. This suggests that it is the allergic condition, not the specific allergy to milk that increases otitis media risk. Downs and colleagues exposed the middle ears of rats to histamine and provoked changes in the pressure regulating and clearance functions of the Eustachian tube. Those changes could prolong an otitis media episode, but middle ear histamine is not limited to the allergic condition. Gentile and colleagues challenged the nose of allergic and nonallergic subjects with histamine followed by interleukin-6 or placebo and measured nasal, pulmonary, Eustachian tube and middle ear functions. Interleukin-6 did not change the Eustachian tube or middle ear functions but did cause increased secretions in allergic patients.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

A large body of research supports a pathogenic role for T helper 2 cells in asthma, although T helper 1 cell-type responses may also contribute. Using the principle of T helper cell cross-regulation, investigators have attempted to regulate the pathological effects of T helper 2 cells using regimens that may promote T helper 1 cell-type inflammation. In this review, we propose that the use of factors that promote T helper 1 cell differentiation and activation to treat asthma may be counterproductive, and that alternate regulatory approaches should be explored.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Airway hyperresponsiveness remains a defining characteristic of asthma. Traditional views assert that airway smooth muscle is an important structural effector cell in the bronchi that modulates bronchomotor tone induced by contractile agonists. New evidence, however, suggests that abnormalities in airway smooth muscle functions, induced by variety of extracellular stimuli, may play an important role in the development of airway hyperresponsiveness. Studies using isolated bronchial preparations or cultured cells show that inflammatory mediators and cytokines may alter calcium homeostasis in airway smooth muscle and render the cells nonspecifically hyperreactive to agonists.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

It is clear that airway smooth muscle plays an important role in the hyperresponsiveness and remodelling that occur in the asthmatic airway. This is by virtue of its roles as a contractile cell, a cell that undergoes proliferation as part of the inflammatory response, a cell that actively participates in the inflammatory response via the production of cytokines and chemokines, and perhaps as a cell that undergoes migration. Now that airway smooth muscle cells cultured from asthmatic patients have been studiedin vitro, it is apparent that there is an abnormality in the growth of these cells such that they grow more rapidly than cells derived from nonasthmatic patients. This raises the possibility of identifying the exact point(s) in the signal transduction pathways at which this abnormality occurs. To do this it is necessary to define precisely the mitogenic pathways that lead to proliferation in the airway smooth muscle cell, and this information is accumulating rapidly. The possibility is raised for new therapeutic targets that are aimed specifically at the airway smooth muscle, leading to an effective method for reversing or preventing the airway remodelling that accompanies chronic severe asthma.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

There continues to be a great deal of interest in the anti-asthmatic role of antihistamines. Antihistamines have recently been shown to have anti-inflammatory properties that are more extensive than simply the blocking of histamine receptors. For example, new evidence suggests that the suppression of cell adhesion molecule expression occurs with these drugs. The anti-inflammatory and anti-asthmatic effects of antihistamines have been evaluated in patients with both allergic asthma and rhinitis, given the established association between allergic inflammation of the upper and lower airways, with evidence to suggest that antihistamines have clinically relevant anti-asthmatic properties. As well as conferring benefits in asthma symptom control and the measurement of lung function, studies assessing the effect of histamine receptor antagonists on bronchial hyperresponsiveness suggest that there is bronchoprotection during both methacholine and mannitol challenges. Recently, there has also been considerable interest in the effect of combining an antihistamine with a leukotriene receptor antagonist. This combination has an anti-asthmatic effect that is greater than that of either drug given alone and may be comparable to inhaled corticosteroid therapy.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Phosphodiesterase type 4 plays an important role in modulating the activity of cells that are involved in the inflammatory processes occurring in chronic obstructive pulmonary disease and asthma. During the past decade, interest has focused on the development of selective inhibitors of phosphodiesterase-4, in an attempt to generate new treatment modalities that control airway inflammation not only in patients with asthma but also in those with chronic obstructive pulmonary disease. The aim of the present review is to discuss the results of recent clinical intervention studies with phosphodiesterase-4 inhibitors in patients with asthma or chronic obstructive pulmonary disease.

ISSN:1528-4050    

出版商:OVID    

年代:2002

数据来源: OVID