Dr. Alexander joined the faculty of Boston University School of Medicine (BUSM) as an Assistant Professor in 1969 and remained with us till his passing on May 17, 2019. He was promoted to Associate Professor in 1973, and to Professor in 1979. He received his secondary appointment in Physiology & Biophysics in 1981. Dr. Alexander earned his BA in biological sciences from Rutgers University, NJ, and his MD from the Feinberg School of Medicine at Northwestern University. He completed his internship and junior residency at Kings County Hospital, Brooklyn, NY, and was senior resident in Medicine at what was then Boston City Hospital (BCH) from 1964-65, with a two-year service at Madigan Army Hospital in between. He served as Research Fellow in Nephrology in the laboratory of Dr. Norman Levinsky at BUSM from 1965-67 and as Research Fellow in Physiology with Dr. Joseph Hoffman at Yale School of Medicine from 1967-69.  
After joining the faculty in Nephrology at BUSM in 1969, Dr. Alexander established an innovative and productive NIH-funded research laboratory in the Thorndike Laboratories at BCH studying kidney physiology. His work was especially instrumental in defining the way in which the kidney regulates acid-base balance and potassium homeostasis. Beginning in 1977 he and Dr. John Schwartz, a former faculty in our Section, developed a long-lasting research partnership that extended well into the first decade of the new millennium exploring the molecular mechanisms of urine acidification.
In addition to his research accomplishments, Dr. Alexander was a revered and beloved clinical teacher and mentor whose legacy is reflected in the accomplishments and devotion of many generations of BUSM students, BCH and BMC residents and Renal fellows. Despite a serious illness in 2016, he returned to work the following year and continued to see patients in the Renal clinic and supervise fellows on the inpatient service at BMC until days before his final illness. Indeed, he was planning to continue as an active clinician and teacher for at least the next year. Our school and hospital were dear to his heart and he regarded us all as his second family.
Earlier in his career he held the following BCH appointments: Director of the Kidney Disease Clinic, Director of the Renal Section, and Associate Director of the Department of Medicine. He was also the Deputy Director of the Sackler student exchange program between the Hebrew University and BUSM that brought outstanding students from Israel to BU on extended elective rotations.
Dr. Alexander was elected to the American Society for Clinical Investigation in 1979. He received the Special Recognition Teaching Award from the Department of Medicine in 1999 and the Jerome Klein Award from BMC for his longstanding contributions to clinical care, education and research in 2013.