Synthesis and in vivo evaluation of a 99m/99Tc-DADT-benzovesamicol: a potential marker for cholinergic neurons

Fifty-six asthmatics from an asthma ward or from an asthma out-patient clinic were challenged with two low concentrations (0.03 and 0.012 mg) of metacholine chloride in order to assess the relationship between pronounced hyper-responsiveness and asthma severity in a clinical setting. Only inhaled bronchodilators were stopped before challenge. Asthma severity was assessed retrospectively and prospectively on the basis of treatment, number of days in hospital, intensive care, number of emergency visits and days on sick-leave. The results show that pronounced hyper-responsiveness (n = 28) is not associated with asthma severity. It is concluded that a single simplified test of pronounced bronchial hyper-responsiveness, performed without taking into consideration the actual state of the disease and without stopping all medication, is of no help in identifying the patients with the clinically most severe asthma and worst prognosis.