1. Bronchial responsiveness to inhaled methacholine was studied in ten heart-lung transplant (HLT) recipients a mean 10.6 months (range 1.5-28 months) post-HLT and in ten normal subjects. 2. The mean provocation dose of methacholine producing a 20% fall in FEV1 (PD20 FEV1) was significantly lower in the HLT recipients (1.70 +/- 3.96 mg vs 11.55 +/- 3.79 mg; P less than 0.001), as was the mean p...

Objective(s): For determining the mechanism of anti-asthmatic effect of thymoquinone, this investigation evaluated the effect of thymoquinone in the presence of selective A2A and A2B adenosine receptor antagonists (ZM241385 and MRS1706, respectively). Materials and Methods: Seventy guinea pigs were randomly divided to 7 groups; control (C), sensitized with ovalbumin (S), sensitized groups pretr...

Inhaled heparin inhibits the early response to allergen and exercise-induced asthma, probably by inhibiting mast cell mediator release. Recent animal studies suggest that heparin might also inhibit cholinergic neurotransmission in asthma by restoring inhibitory M2 receptor function. We have tested the hypothesis that heparin inhibits neurally-mediated bronchoconstriction in asthma by examining ...

Previous reports suggest that regular use of beta-agonists does not lead to tolerance to their bronchodilator effects. However, most studies have been conducted in stable asthma. This study investigates whether bronchodilator tolerance can be demonstrated during acute bronchoconstriction. Thirty-four asthmatic subjects were treated with 6 weeks inhaled terbutaline (1 mg q.i.d.), budesonide (400...

The adenosine analogue phenylisopropyladenosine decreased the basal and isoproterenol-stimulated contractile state of isolated rat left atria. The ED50 levels for both responses were similar, suggesting that direct and antiadrenergic effects may be mediated by the same receptor. Phenylisopropyladenosine decreased the cyclic adenosine monophosphate content of isolated atria and inhibited isoprot...

With the aim of investigating the presence of latent inflammatory process in the lungs of patients with Crohn's disease, 15 patients with Crohn's disease were evaluated by spirometry, the methacholine challenge test, induced sputum, and skin tests for inhaled antigens. Serum IgE, erythrocyte sedimentation rate and hematocrit were also determined. The patients were compared with 20 healthy contr...

Adenosine 5'-monophosphate (AMP) and methacholine are commonly used to assess airway hyperreactivity. However, it is not fully known whether the site of airway constriction primarily involved during challenges with either agent is similar. Using a ventilation distribution test, we investigated whether the constriction induced by each agent involves the lung periphery in a similar fashion. Venti...

A simple device aiming to increase deposition of nebulized methacholine in the lower airway was studied. The device controlled inspiratory flow and volume and dried the aerosol. The effect of drying on deposition in the throat and lower airways was studied in six subjects given an aerosol of 99mTechnetium-diethylenetriamine pentaacetate (DTPA) in saline with the device and with a reference devi...

Hypertonic saline (HS) is used in sputum induction studies. However, little is known about the physiological effects of HS on human airways in vivo. The present study takes advantage of the fact that the airway effects of topical challenges may be accurately examined in the readily accessible nasal airway. The present study specifically examines whether exposure to HS affects histamine challeng...

Hyperresponsiveness of the airways to various spasmogenic stimuli is a characteristic feature of bronchial asthma. However, the association between the different stimuli to which asthmatic airways are hyperresponsive and airways inflammation is not completely understood. We have investigated the relationship between airway inflammation and airway hyperresponsiveness in asthma, as assessed by br...