Faculty: Justin Ziemba, MD and Joshua Stern, MD

Moderator: Kris Penniston, Ph.D., RDN


Justin B. Ziemba, M.D. M.S. Ed.

Justin B. Ziemba, M.D. M.S. Ed. is currently an Assistant Professor of Urology in Surgery at the Perelman School of Medicine of the University of Pennsylvania. Dr. Ziemba completed his residency training at the Hospital of the University of Pennsylvania. Following this, he spent 2 years as a clinical and research fellow in minimally invasive surgery and endourology at the James Buchanan Brady Urological Institute of the Johns Hopkins Hospital and Instructor of Urology at the Johns Hopkins School of Medicine. He also completed a master of science in education from the University of Pennsylvania Graduate School of Education.

Dr. Ziemba’s clinical focus is on the surgical treatment and medical management of kidney stone disease. This clinical focus is supported by a McCabe Foundation Award aimed at understanding how kidney stone treatment may impact a patient’s health-related quality of life. He is also a co-investigator on several federally funded research projects. The first funded by the NIH examines the application of machine learning to CT imaging to assist with clinical and surgical decision making. The second funded by PCORI examines the clinical effectiveness and impact on the quality of life of children who undergo surgical treatment for kidney stones.

Joshua Stern, MD

Dr. Joshua Stern is the Chief of Urology at Park City Hospital, Intermountain Healthcare in Utah. Dr. Stern is a fellowship trained, board-certified urologist specializing in the treatment of complex kidney stones and kidney tumors. He was formally the director of Endourology and the Kidney stone program at the Albert Einstein College of Medicine in New York City, where he developed an integrated, high volume kidney stone center that focused on innovative approaches to endoscopic kidney stone surgery. With grant support from the National Institutes of Health (NIH), Dr. Stern was one of the first to report on the interplay between the gut microbiome and kidney stones. Dr. Stern is a graduate of the University of Pennsylvania. He obtained his medical degree from The Weill Cornell Medical College and completed his residency in urology from the University of Texas, Southwestern Medical Center. Dr. Stern is also a graduate of the University of Pennsylvania Minimally Invasive Robotic Urology Fellowship. He is currently a member of the American Urological Association, The ROCK society and the Endourology society

Moderator: Kris Penniston, Ph.D., RDN

Kristina Penniston is a scientist and registered dietitian nutritionist in Madison, Wisconsin. Dr. Penniston earned a PhD in nutritional science from the University of Wisconsin-Madison. She completed a dietetic internship at the University of Wisconsin Hospital and Clinics and is a fellow of the Academy of Nutrition and Dietetics. Dr. Penniston has provided clinical nutrition services to patients with kidney stones and other urologic diseases for >20 years. Dr. Penniston's research focuses on prevention of kidney stones with a specific interest in developing and testing dietary interventions that prevent recurrent stones and enhance patients' self-efficacy in managing their stone disease. She was the primary developer of the Wisconsin Stone Quality of Life questionnaire (WISQOL), a stone-specific instrument to assess patients' health-related quality of life. Dr. Penniston leads the North American Stone Quality of Life consortium, a clinical research collaboration of 17 urology centers in the US and Canada, the primary aims of which are to test and validate the WISQOL and understand how kidney stones affects patients’ health-related quality of life. Dr. Penniston is a member of the American Urological Association (AUA) and is a former AUA research scholar (2008-2010). She is currently the Secretary-Treasurer for the Research on Calculus Kinetics (ROCK) Society.