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The prevalence of asthma has been increasing in the United States since the early 1980s, afflicting 14.6 million people in 1994 and more than 17 million people in 1998. In 1994 alone, the cost of treating this chronic lung disease was estimated at $10.7 billion. Besides AIDS and tuberculosis, asthma is the only chronic disease with an increasing death rate — every day 14 Americans die from it. Characterized by inflammation and temporary narrowing of the passages that transport air to the lungs, asthma is increasingly common in children.
Biomedical Engineering Professor Kenneth Lutchen and graduate student Andrew Jensen (ENG'01) have been working to determine if asthma stems from a defect in the function of the smooth muscle of the airway. They developed a method to monitor in real time the action of the airway muscles while the patients, both healthy and asthmatic, are breathing. They found that the smooth muscles in the airways of asthmatics are different from those in healthy individuals, constricting with greater force and becoming stiffer when constricted. The stiffness prevents the airway from reopening during a deep breath. Lutchen and his colleagues are now investigating the factors that create this stiffness in airway muscle fibers. They suspect that it may be related to increased thickness of the muscle and decreased periodic stretching.
This research was reported in the Journal of Applied Physiology, and will be featured as a Highlighted Topics Selected Contribution in the July issue.
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