The current research interests of Young S. Han, Ph.D., are twofold: First, Dr. Han focuses on pathophysiological mechanisms by which accidental hypothermia-rewarming patients are associated with cardiac contractile dysfunction, and second, he is interested in the mechanisms by which airway inflammation results in airway smooth muscle (ASM) hyperreactivity of asthma.
To better understand these mechanisms, Dr. Han uses models to evaluate changes in intracellular Ca2+ concentration and force of contraction at the tissue and cellular levels. Changes in regulatory processes at the protein level also are of interest to Dr. Han.
- Impact of hypothermia/rewarming (H/R) on Ca2+ sensitivity and contractility. Dr. Han examines the hypothesis that H/R reduces Ca2+ sensitivity and contractility in cardiomyocytes.
- Molecular mechanisms underlying reduced Ca2+ sensitivity following H/R. The hypothesis that reduced Ca2+ sensitivity is associated with changes in phosphorylation of regulatory sarcomere proteins is explored in Dr. Han's studies.
- Impact of pro-inflammatory cytokine, TNF on ASM Ca2+ sensitivity and contractility. Dr. Han tests the hypothesis that TNF alters Ca2+ sensitivity and contractility.
Significance to patient care
The pathophysiological mechanisms of post-hypothermic cardiac contractile dysfunction remain elusive, leaving mortality after accidental hypothermia between 50 and 80 percent. The determination of such mechanisms is critical to comprehensive treatment of hypothermia-induced heart failure in the clinical setting.
Dr. Han's findings will also have an impact on the treatment of asthma. Chronic airway inflammation is a key aspect of asthma, and understanding the mechanisms of ASM hyperreactivity induced by airway inflammation will provide insight into the development of therapeutic strategies.