BACKGROUND The diagnosis of occupational asthma (OA) can be challenging and needs a stepwise approach. However, the predictive value of the methacholine challenge has never been addressed specifically in this context. OBJECTIVE We sought to evaluate the sensitivity, specificity, and positive and negative predictive values of the methacholine challenge in OA. METHODS A Canadian database was ...

Nagayama, Takahiro, Yasuo Fukushima, Hirohiko Hikichi, Makoto Yoshida, Mizue Suzuki-Kusaba, Hiroaki Hisa, Tomohiko Kimura, and Susumu Satoh. Interaction of SKCa channels and L-type Ca 21 channels in catecholamine secretion in the rat adrenal gland. Am J Physiol Regulatory Integrative Comp Physiol 279: R1731–R1736, 2000.—We elucidated the interaction of small-conductance Ca-activated K (SKCa) ch...

PURPOSE Dyspnea is not widely utilized as an indicator of asthma provocation despite its universal presentation. We hypothesized that dyspnea severity was proportionate with the lung function decline, methacholine dose-step, and the degree of bronchial hyperresponsiveness (BHR). METHODS We retrospectively analyzed 73 children's bronchial provocation test data with an assessment of dyspnea at ...

An acoustic whole body plethysmograph was developed to estimate specific airway resistance (sRaw) in unrestrained mice. The plethysmograph uses acoustic principles to measure the thoracic breathing pattern and simultaneously measures the airflow entering and/or leaving the plethysmograph. Similarly to traditional methods utilizing a double-chamber plethysmograph, these measurements were combine...

BACKGROUND A decline in host resistance due to an alteration in diet--primarily of salt--was recently put forward as a possible explanation for rising rates of asthma. METHODS A case-control study was conducted in participants in a prevalence survey which included 187 children with asthma (defined by prior diagnosis and/or a decline in forced expiratory volume in one second (FEV1) of > or = 1...

BACKGROUND Exposure to the bronchoconstricting agent methacholine is a potential hazard to technical staff during methacholine challenge testing, which remains a useful and frequently performed test. There are several methods of performing the test. One of the 2 methods listed in the American Thoracic Society's guidelines is the 2-min tidal-breathing method. The methacholine can be inhaled usin...

The nasal responses to provocation with histamine and methacholine were compared in 20 subjects with and 20 without rhinitis. Two variables were measured: nasal airways resistance and the development of rhinorrhoea. Histamine had a greater effect than methacholine in increasing nasal airways resistance while the converse was true for rhinorrhoea. Rhinitic subjects had a significantly greater re...

To evaluate bronchial reactivity to methacholine in human immunodeficiency virus (HIV) infection, we submitted 25 HIV-seropositive subjects without full-blown AIDS and 25 HIV-seronegative subjects, all inmates in a drug rehabilitation center for previous intravenous drug abuse, to interview and to bronchial challenge with methacholine. Four (16 percent) HIV-seropositve and three (12 percent) HI...