The regional pattern and extent of airway closure measured by three-dimensional ventilation imaging may relate to airway hyperresponsiveness (AHR) and peripheral airways disease in asthmatic subjects. We hypothesized that asthmatic airways are predisposed to closure during bronchoconstriction in the presence of ventilation heterogeneity and AHR. Fourteen asthmatic subjects (6 women) underwent c...

BACKGROUND Methacholine dose-response curves illustrate pharmacologic bronchoprotection against methacholine-induced airway hyperresponsiveness and can be used to quantitate changes in airway sensitivity (position), reactivity (slope), and maximal responsiveness following drug administration. Our objective was to determine the influence of single-dose glycopyrronium (long-acting muscarinic anta...

To determine whether methacholine causes vagally mediated reflex constriction of airway smooth muscle, we administered methacholine to sheep either via the bronchial artery or as an aerosol via tracheostomy into the lower airways. We then measured the contraction of an isolated, in situ segment of trachealis smooth muscle and determined the effect of vagotomy on the trachealis response. Adminis...

Bronchial challenge with direct stimuli, like histamine and methacholine, is very sensitive for diagnosing asthma and produces similar responses on a milligram-on-milligram or on a millimole-on-millimole basis [1–4]. American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines have proposed measures in order to protect technicians performing these tests, which include the use o...

BACKGROUND Two bronchoprovocation methods are widely used. Compared to the tidal breathing method, the dosimeter method delivers approximately half the dose and involves five deep inhalations. Both the lower dose and the bronchoprotective deep inhalations contribute to the lesser airway response of the dosimeter. OBJECTIVE To determine the relative role of dose and deep inspiration in the dif...

BACKGROUND The airway muscles from allergen-sensitized animals in vitro show a heightened response to histamine, but not to carbachol. This study investigated whether the airway responsiveness to histamine in vivo is comparable to that of methacholine in human subjects with varying degrees of atopy. METHODS One-hundred-and-sixty-eight consecutive adult asthma patients or volunteers underwent ...

PURPOSE Obesity has been suggested to be linked to asthma. However, it is not yet known whether obesity directly leads to airway hyperreactivity (AHR) or obesity-induced airway inflammation associated with asthma. We investigated obesity- related changes in adipokines, AHR, and lung inflammation in a murine model of asthma and obesity. MATERIALS AND METHODS We developed mouse models of chroni...

I read with interest the valuable article by Pratter et al (November 1999),1 regarding the role of sinus imaging in the management of chronic cough. Figure 2 in this article contains a useful algorithm for investigation and treatment of chronic cough. Unfortunately, one potentially important cause of cough will be missed by following this algorithm. Eosinophilic bronchitis is a recently describ...