Luke TanLuke Tan is an MSc candidate in the Department of Physiology at the University of Toronto under the supervision of Dr. Carin Wittnich. Luke’s thesis investigates whether gender plays a role in antioxidant defense systems when protecting against oxidative damage in the newborn heart during high-oxygen conditions (hyperoxia).
Clinical studies in children show females have a higher risk of death than males post cardiac surgery. These studies serves as evidence suggesting female sex is a risk factor for children undergoing cardiac surgery. Luke’s research is focused on uncovering why female sex is a risk factor that leads to the pronounced female death rate. One major reason for cardiac surgery in children is the presence of congenital heart defects (CHD). As of 2008, the American Heart Association reports that CHDs are suffered by 8 in every 1000 newborns. Depending on the treatment course of CHD, newborns may be subjected to a high-oxygen (hyperoxic) condition (eg. cardiopulmonary bypass and extracorporeal membrane oxygenation). Hyperoxia generates reactive oxygen species (ROS), which are cytotoxic (damages/kills cells). However, the body has natural defenses against the oxidative stress created by ROS called antioxidants, which neutralize free radicals. Antioxidant activity is present in newborn myocardium, however whether there are gender-related differences is currently unknown and is the focus of Luke’s study.
Luke’s work addresses the potential female-male differences in antioxidant defense systems and oxidative damage experienced during hyperoxia. By utilizing a well-established piglet model, Luke’s work will ultimately provide key insights on sex-related differences regarding how newborn hearts handle oxidative stress, and ultimately why females have worse outcomes post cardiac surgery.
Left to Right: Kathryn Phenix (Mrs. Phenix's daughter), Mrs. Geraldine Phenix,
Luke Tan, Dr. Margaret Rand (Chair, Awards Subcommittee)