Jason Deen, MD

Dr. Jason Deen is a fellow in the department of cardiology at Seattle Children's Hospital. He received his medical degree from the University of Minnesota Medical School in 2006 before completing a combined internal medicine and pediatrics residency at the same institution. His research interests include cardiovascular risk stratification in adults with congenital heart disease, dyslipidemia and cardiovascular health disparities. 

Matthew Files, MD

Dr. Matt Files is a third-year pediatric cardiology fellow at Seattle Children's Hospital and is working in the Portman Research Group. He completed his pediatrics residency at Oregon Health and Science University prior to moving to Seattle. His research projects are translational in nature with a focus on pediatric extracorporeal membrane oxygenation (ECMO). He is currently studying cardiac metabolism during ECMO and the influence of thyroid hormone. The goal of this work is to develop metabolic strategies that will improve outcomes for children supported with ECMO.

Masaki Kajimoto, MD

Dr. Masaki Kajimoto is a post-doctoral research fellow. He received his MD (1999) and PhD (2006) from Mie University, Japan. Prior to joining Dr. Portman's research group in 2010, he worked as a pediatric cardiovascular surgeon in Japan. His research interests include myocardial metabolism related to cardiopulmonary mechanical support.

Dolena Ledee, PhD

Dr. Dolena Ledee is a research scientist in the Portman Research Group. She received a PhD in molecular genetics from Ohio State University and did postdoctoral fellowships at the National Institutes of Health and the University of Pennsylvania. Her current research interests include studying the changes in signaling pathways involved in the heart during and after cardiac surgery due to the introduction of various metabolites. Additionally, she is studying thyroid hormone signaling pathways changes in the heart during the aging process.

Aaron Olson, MD

Dr. Aaron Olson is an attending physician at Seattle Children's Hospital and an assistant professor in the Department of Pediatrics at the University of Washington School of Medicine. His clinical work is in general pediatric cardiology. His research interests include pharmacological clinical trials and metabolic regulation in the heart.

Miriam Silva, MD

Dr. Miriam Silva, Clinical Research Coordinator II, is Dr. Michael Portman's coordinator in cardiology at Seattle Children's Research Institute. She has a BS in chemistry and a medical degree. Silva is currently assisting on studies that involve children with Kawasaki disease. Her research experience started at Texas Tech University Health Science Center in El Paso, conducting studies in obesity. She also conducted cardiology studies at Austin Heart in Austin, Texas.

Silva is a member of the Seattle Children's Research Staff Development Committee and is a volunteer for Junior Achievement. She is also involved in helping the homeless and youth around the community.

Kevin Xu, PhD

Dr. Kevin Xu is a research scientist in the Portman Research Group. He is working on a cardiac metabolism project with newborn swine model circulatory supported by extracorporeal membrane oxygenation (ECMO) and lab management. He has a medical background and received his PhD in electrophysiology. He has conducted studies in potassium and calcium channels modulation in both the central nervous system and the myocardium. He joined Seattle Children's in 2010.