Brian J O'connor

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RATIONALE Exhaled breath nitric oxide (Fe(NO)) is increased in asthma. NO is produced predominantly by inducible nitric oxide synthase (iNOS). OBJECTIVES We evaluated the selective and potent iNOS inhibitor GW274150 in asthma. METHODS Twenty-eight steroid-naive patients with asthma participated in a double-blind, randomized, double-dummy,(More)
The concentration of nitric oxide (NO) is increased in the exhaled air of asthmatic patients and may reflect cytokine-mediated inflammation in the airways. We investigated whether allergen-induced inflammation causes an elevation in the level of exhaled NO. Of 25 patients who underwent allergen challenge, 16 developed dual early and late responses, whereas(More)
Asthma and chronic obstructive pulmonary disease (COPD) are associated with Th2 and Th1 differentiated T cells. The cytokine thymic stromal lymphopoietin (TSLP) promotes differentiation of Th2 T cells and secretion of chemokines which preferentially attract them. We hypothesized that there is distinct airways expression of TSLP and chemokines which(More)
Sputum induction with nebulized hypertonic saline is increasingly being used to evaluate airway inflammation. We investigated the procedure-associated risk in 16 asthmatics that were still symptomatic despite on high doses of regular corticosteroid (CS) therapy (7 on daily inhaled CS > or = 800 microg budesonide or equivalent; 9 on additional daily oral CS)(More)
Phenotypic modulation of airway smooth muscle (ASM) is an important feature of airway remodeling in asthma that is characterized by enhanced proliferation and secretion of pro-inflammatory chemokines. These activities are regulated by the concentration of free Ca(2+) in the cytosol ([Ca(2+)](i)). A rise in [Ca(2+)](i) is normalized by rapid reuptake of(More)
BACKGROUND Analysis of bronchoalveolar lavage fluid has improved our understanding of the pathogenesis of asthma. Safety issues and access to expert resources limit this techniques as a research tool. Induced sputum is a non-invasive method of collecting airway fluid which is applicable to subjects with a range of severity of airflow obstruction. The method(More)
RATIONALE Asthmatic airways have an increased number and size of vascular structures, which contribute to airflow obstruction and hyperresponsiveness. OBJECTIVES We examined whether proangiogenic mediators are elevated in bronchoalveolar lavage fluid (BALF) from subjects with asthma and if this translated to induction of angiogenesis. METHODS Angiogenic(More)
BACKGROUND Inhaled glucosteroids and oral theophylline are widely used to treat asthma. We compared the benefits of adding theophylline to inhaled glucosteroid with those of doubling the dose of inhaled glucosteroid in patients with persistent symptoms despite the use of inhaled glucosteroid. METHODS In a double-blind, placebo-controlled trial, we(More)
Beta-blockers are currently contraindicated in asthma because their acute administration may be associated with worsening bronchospasm. However, their effects and safety with their chronic administration are not well evaluated. The rationale for this pilot study was based on the paradigm shift that was observed with the use of beta-blockers in congestive(More)
Nitric oxide (NO) is detectable in the exhaled air of human subjects, and its concentration is increased in patients with asthma. We have investigated the origin of the increase in exhaled NO in asthmatic patients by using different expiratory maneuvers and by direct sampling from the upper and lower respiratory tracts. Exhaled NO was measured by a(More)