My mentor and friend of 40 years, Donald Overton Castell or as most of us knew him, DO or DOC passed away Jan 8, 2021.  Born in 1935, the son of a butcher, DO was an accomplished trumpet player as a young boy, a concert master in high school and lead trumpet for the Maryland State Band.  His musical talents helped pay for college and medical school at GW in Washington after which like many he joined the Navy for internal medicine residency. It would surprise no one who knew him that in a 20 year career he never went out to sea. While a resident he published a single author paper in Gastroenterology on of all things ammonia levels in liver disease.  While a GI fellow at Tufts he published the first article on nuclear liver scanning in cirrhosis in the New England Journal and an in 1967 an article in the Annals of Internal Medicine describing what is still known as Castell’s sign; the most accurate percussion technique for assessing spleen size.  Like many of us he was stimulated by one of his mentors to develop an interest in the esophagus and in 1970  published on the effects of gastrin on LES function in the New England Journal.  The rest as one might say is history. The beginning of 50 years of esophageal research, over 600 publications (all edited with a ‘green pen”), enhancing our knowledge of esophageal physiology, pH monitoring, non cardiac chest pain,  nutcracker esophagus, PPI pharmacodynamics, nocturnal gastric acid breakthrough, IEM, impedance  and non acid reflux. We in the AFS know Don from his long standing collaboration and friendship with the preeminent foregut surgeon Tom DeMeester highlighted by the annual 6 day winter “Hawaii course”.  Don in the front row right, Tom in the front row left, USC faculty v Graduate Hospital faculty each bringing their newest research in a preview of the SSAT and AGA esophageal and foregut programs at DDW.  Who would be invited to be the surgical guest and medical guest faculty???  Their 30 plus years of “friendly fights” were the forerunner of the collaboration and synergies we in AFS have created.

I met DO in 1981 when I was Chief Resident in Medicine at Bowman Gray (now Wake Forest) School of Medicine.  An avid tennis player we spent many an afternoon (evening and night) exchanging top spin forehands and weak backhands with breaks to discuss my career, eventually convincing  me to join him as his GI fellow.  He, along with Joel Richter, taught me to do clinical research, pushed, cajoled, mentored and promoted me as he did seemingly endless young investigators over the next 40 years.  He introduced me to my AFS friends in Hawaii in 1997 when he recruited me from Hopkins to join him in Philadelphia.  He was a master educator, unselfish mentor, and generous promoter who welcomed all who strived to share his passion for esophageal research (and tennis!). There was a rare day when he didn’t have a smile on his face and a welcoming hello.  I am among the many who were lucky to have known him as a mentee, a colleague and friend.  We were all lucky to have had the opportunity to learn from him.  He will be missed.

PO Katz