 In this study, researchers found that patients with chronic obstructive pulmonary disease, COPD, have higher levels of free radicals, lower levels of antioxidants, and damaged vascular endothelium. This suggests that oxidative stress may be playing a key role in the progression of COPD. This article was authored by A. M. Saburova, K. Charnaisertsenova, K. Tyosherapova, and others.