In Memoriam
Faculty
Michael Vitti, MD, assistant professor of surgery and director of the Eastern Vascular vein center, died Jan. 22, 2026.
Jason Greenberg, MD, assistant professor of neurology, died Jan. 3, 2026.
Robert Lifton, MD, lecturer in psychiatry, died Sept. 4, 2025.
Alumni
1946
John Keith Spitznagel, an internist and immunologist who founded the Good Samaritan Health and Wellness Center in Jasper, Georgia, died Jan. 14, 2026. He was 102. After earning undergraduate and medical degrees from Columbia University, he later trained at the Johns Hopkins Hospital and Barnes Hospital of Washington University, and spent a year as a visiting investigator at the Rockefeller Institute for Medical Research. He served in several positions in the U.S. Army Medical Corps, including as an instructor in basic sciences at Walter Reed Hospital, as an assistant chief of medicine with the 114th Field Hospital in Kyushu, Japan, and as chief of medicine at Fort Bragg, rising to the rank of lieutenant colonel. In 1957, Dr. Spitznagel joined the University of North Carolina School of Medicine, where he advanced to professor of internal medicine and bacteriology and became internationally recognized for his National Institutes of Health-funded research on the mechanisms by which white blood cells combat bacterial infections. In 1979, he was appointed chair of microbiology and immunology at Emory University, where he served until retiring as professor emeritus. He is honored annually with the Spitznagel Annual Seminar on Host Defense. During retirement, in 2002, he founded the volunteer-run Good Samaritan clinic, which is a federally qualified health center that continues to foreground compassionate, accessible health care. Dr. Spitznagel enjoyed reading, fly-fishing, and playing the flute. He was predeceased by his wife, Anne, and is survived by five children, 14 grandchildren, and five great-grandchildren.
1949
Seymour Perlin, an academic psychiatrist and pioneer in suicidology, died Nov. 20, 2025. He was 100. Born in Passaic, New Jersey, he graduated from Princeton University, where he enjoyed an assignment to escort Albert Einstein to university seminars. Dr. Perlin completed training at the University of Michigan Hospital, the New York State Psychiatric Institute, and the Washington Psychoanalytic Institute before serving as chief of psychiatry at the National Institute of Mental Health. He founded the Division of Psychiatry at Montefiore Hospital and later held senior academic roles at the Johns Hopkins University School of Medicine and the Henry Phipps Psychiatric Clinic, where he established the first postgraduate fellowship program in the U.S. for the study of suicide. In 1967, he received Columbia University’s Silver Bicentennial Medallion for Achievement in Psychiatry. In 1974, he joined the faculty of the George Washington University School of Medicine and Health Sciences, where he directed psychiatry residency training for more than 15 years. A founder of the American Association of Suicidology, he made significant contributions to the scientific literature in the areas of suicidology, aging, community mental health, and medical ethics. Dr. Perlin was the author of more than 50 scholarly publications as well as two definitive anthology textbooks, “A Handbook for the Study of Suicide” and “Ethical Issues in Death and Dying” (co-editor). Outside of medicine, he was an avid gardener, traveler, and devoted patron of the arts. He is survived by his wife, Ruth, three sons, and seven grandchildren.
1952
Bayard D. Clarkson, an oncologist, hematologist, and leader in leukemia research, died Dec. 30, 2025. He was 99. Born in Bayville, New York, Dr. Clarkson attended St. Paul’s School and later Yale University. His education was interrupted by World War II, during which he served with the American Field Service as an ambulance driver in Italy and Germany and participated in the evacuation of the concentration camp at Bergen-Belsen. After the war, he resumed his studies and completed a Lasker Fellowship in clinical chemotherapy at Memorial Hospital, which later merged with the Sloan-Kettering Institute to form Memorial Sloan Kettering Cancer Center. Dr. Clarkson would remain at Memorial Sloan Kettering for more than five decades, serving in roles including chief of the Hematology/ Lymphoma Service, director of fellowship training in hematology and medical oncology, and associate chairman for research in the Department of Medicine. During his tenure, he contributed to the expansion of the hospital’s leukemia research program and helped develop curative therapies for acute lymphoblastic leukemia. He was recognized for his work on intracellular signaling pathways altered by BCR-ABL fusion genes, key drivers in certain types of leukemia. Additionally, he served as president of the American Society of Clinical Oncology and held leadership roles within the American Association for Cancer Research. He served on the board of trustees of Clarkson University, where he held an ancestral connection. He enjoyed sailing, rowing, and traveling with family. Predeceased by his wife, Virginia, Dr. Clarkson is survived by four children, six grandchildren, and eight great-grandchildren.
1954
Donald Dallas, a cardiologist and former chief of medicine at St. Luke’s Hospital in New York City, died Nov. 18, 2025. He was 96. Born to immigrant parents from Scotland and Germany, Dr. Dallas was the first in his family to attend college. He graduated from Columbia College in 1950 and, during medical school, married his sixth grade sweetheart, the artist Dorothy Benz Dallas. He went on to serve in the U.S. Public Health Service and Coast Guard following medical school. He is survived by four children, six grandsons who called him “Babbo,” and four beloved dogs.
1955
Alfonse “Al” Thomas Masi, a rheumatologist, epidemiologist, and prolific physician-scientist, died March 6, 2025. He was 94. A first-generation Italian American and native of New York City, Dr. Masi completed his undergraduate studies at the City College of New York. He pursued advanced training in internal medicine, epidemiology, and rheumatology at the Johns Hopkins Hospital, the Centers for Disease Control and Prevention’s Epidemic Intelligence Service in Puerto Rico, UCLA Medical Center, and the National Institutes of Health. He also earned a Doctor of Public Health degree from Johns Hopkins University. Dr. Masi began his academic career as chief of rheumatology at the University of Tennessee College of Medicine before joining the University of Illinois College of Medicine Peoria, where he served as the founding head of the Department of Medicine and later as professor emeritus. He authored more than 220 publications and was widely recognized for his pioneering work on neuroendocrine- immune mechanisms in rheumatoid arthritis. He had his last rheumatology paper accepted for publication at the age of 92. Outside of medicine, he loved traveling, sipping rum, watching classic movies, playing his bongo drum, bodysurfing, and dancing. He is survived by his wife, Nancy, four children, and nine grandchildren.
1956
Walton K.T. Shim, who was born in Hawaii and returned to the island to shape pediatric surgical care across the Pacific region, died Nov. 4, 2025. He was 94. Dr. Shim graduated from ‘Iolani School and Dartmouth College before serving as a captain and surgical consultant in the U.S. Army from 1962 to 1964. After his training in Chicago, he shifted his professional focus back to Hawai‘i in 1967, eventually becoming a founding member of the Pacific Association of Pediatric Surgeons. He became a professor of surgery and pediatrics at the John A. Burns School of Medicine and held several leadership roles at Kapi‘olani Medical Center for Women & Children, including division chief of pediatric surgery and multiple terms as chief of staff and chief of surgery. He found great joy in the outdoors. At the time of his passing, he was living on his property in the rugged landscape of Montana. He also loved tennis and tending to his vegetable garden, and was a devoted supporter of the symphony. He is survived by his wife, Vicki, four children, and six grandchildren.
1957
Michael Lazor, former chair of nephrology at Hartford Hospital, died Nov. 11, 2025. He was 94. Born in Tarrytown, New York, to Czechoslovakian immigrants, Dr. Lazor earned his undergraduate degree from Williams College. He completed his residency training in Madison, Wisconsin, followed by a rotation at the National Institutes of Health. Dr. Lazor spent his clinical career at Hartford Hospital. In 1996, he played a central role in founding Connecticut Multi-Specialty Group, helping to unite physicians across practices to strengthen patient care; the group later grew into one of the largest multispecialty organizations in New England. He was an avid traveler, gardener, and enthusiastic home cook. He faithfully cheered for the New York Giants, the Knicks, the Yankees, and UConn basketball. His porch was always stacked with daily newspapers, which he read cover to cover. He is survived by three children, eight grandchildren, and four great-grandchildren.
1958
William “Bill” Hopewell, who practiced medicine for decades in Ridgewood, New Jersey, died Nov. 18, 2025. He was 93. Raised in Mariemont, Ohio, Dr. Hopewell earned his undergraduate degree from Yale University, where he was a varsity football player. He completed his medical training and went on to establish a long and respected clinical career in northern New Jersey. He built a trusted private practice and served on multiple medical boards at Valley Hospital. He was an avid runner who completed five marathons, a devoted traveler, and a gifted artist who painted more than 300 dog portraits. He loved reading, opera, crossword puzzles, Cape Cod, and rescuing animals. He was deeply engaged in church life at Mount Auburn Presbyterian Church in Cincinnati. He is survived by his wife of 72 years, Jane, three children, seven grandchildren, and six great-grandchildren.
1959
James Rose Carter Jr., internist and educator, died Sept. 17, 2025. He was 92. He graduated from Princeton University, then completed his internal medicine residency at Massachusetts General Hospital, where he served as chief resident, and conducted research at the National Institutes of Health on transport mechanisms affected by diabetes. Dr. Carter held academic appointments at Harvard and the University of Pennsylvania before joining the faculty at Case Western Reserve University, where he remained for 26 years and attained the position of professor of medicine, emeritus. He was a fellow of the Academy of Medicine and became chair of the Department of Medicine at MetroHealth Medical Center, a teaching hospital for the university. Dr. Carter helped to develop the primary care track for medical students and won numerous accolades and teaching awards. He loved the outdoors, especially climbing the Presidential Range in the White Mountains of New Hampshire. He collected art, was an avid reader of classic literature, and cheered on Boston sports teams from wherever he resided. He is survived by his wife, Susan, two children, and four grandchildren.
Theodore “Ted” Johnson, an obstetrician-gynecologist who practiced for 31 years alongside his brother at Grove Hill Clinic in New Britain, Connecticut, died Dec. 21, 2025. He was 93. A native of New Britain, Dr. Johnson earned his undergraduate degree from Harvard University. He spent a year conducting research at the University of Birmingham in England during medical school and went on to complete his internship at the University of Chicago and his residency at the University of California, San Francisco. He served as a captain in the U.S. Air Force at James Connally Air Force Base, Waco, Texas, before returning to Connecticut. He was a passionate advocate for women’s health and a longtime supporter of Planned Parenthood. Beyond medicine, he embraced Unitarian Universalism and actively participated in the UU Fellowship of New Britain and the Unitarian Society of Hartford. A passionate musician, he sang, played brass instruments, performed with local chorales, helped found the CONCORA professional choir, and was a constant whistler of everything from Beatles tunes to classical melodies. He is survived by his wife, former U.S. Rep. Nancy L. Johnson; three daughters; 10 grandchildren; six great-granddaughters; and four great-grandsons.
Alan Neil Schechter’63, an Esteemed Columbia Medicine Board Member
Alan Neil Schechter, a pioneering physician-scientist who devoted six decades to the National Institutes of Health (NIH) and served as a longtime editorial board member of Columbia Medicine, died Oct. 15, 2025. He was 86. Dr. Schechter graduated from Cornell University and completed clinical training at the Albert Einstein College of Medicine before joining the NIH Laboratory of Chemical Biology, where he worked on the fundamental processes of protein folding with Nobel laureate Christian B. Anfinsen. In 1981, he succeeded Dr. Anfinsen as chief of what is now the Molecular Medicine Branch of the National Institute of Diabetes and Digestive and Kidney Diseases. His investigations into hemoglobin S polymerization helped pave the way for hydroxyurea as a Food and Drug Administration-approved therapy for sickle cell disease. In later years, his research on nitric oxide biology advanced understanding of vascular regulation and ischemic disease, generating multiple patents and opening new therapeutic avenues. A devoted mentor, he exemplified the physician-investigator ideal, training generations of physicians to think like researchers and researchers to understand clinical medicine. He served as acting NIH historian and a leader within the Foundation for Advanced Education in the Sciences. An avid art collector, he recently loaned part of his extensive collection of 19th century Japanese woodblock prints to the Vassar College Frances Lehman Loeb Art Center. He was always eager to learn from others and had an extraordinary capacity to connect people across disciplines. As a Columbia Medicine editorial board member, Dr. Schechter contributed intellectual rigor, deep institutional memory, and generous collaboration to help shape issues that reflected the best of VP&S clinical advances and research. He is survived by his wife of 60 years and medical school classmate, Geraldine Poppa Schechter’63, the former chief of hematology at the Washington Veterans Administration Hospital; two children; four grandchildren; and a sister.
1964
John Mulliken, a pioneering pediatric plastic and reconstructive surgeon who devoted himself to the art and science of caring for children with facial differences, died Jan. 20, 2026. He was 87. Dr. Mulliken earned his undergraduate degree magna cum laude from Princeton University. He completed general surgery training at Massachusetts General Hospital before joining the U.S. Army Medical Corps. He served as a commanding officer of the 43rd Mobile Army Surgical Hospital in Uijeongbu, Korea, and later the chief of surgery at Cushing Hospital at Fort Devens in Massachusetts. He completed a plastic surgery fellowship at the Johns Hopkins Hospital and, in 1974, joined Boston Children’s Hospital, where he spent his career as a pioneering surgeon, researcher, and teacher. He served as director of the Craniofacial Center, director of the Cleft Lip and Palate Program, and co-director of the Vascular Anomalies Center, building internationally recognized programs. A professor of surgery at Harvard Medical School, he transformed the care of children with vascular anomalies and craniofacial differences, co-developing the widely adopted Mulliken classification system and advancing genetic and surgical understanding of complex congenital conditions. He was awarded the VP&S Alumni Association’s Gold Medal for Excellence in Clinical Medicine in 2008. Outside of medicine, he had a deep love of history and the arts. He is survived by his wife, Portia, and one daughter.
1965
John Geary Gregory, a longpracticing urologist and committed mentor, died Oct. 26, 2025. He was 87. Dr. Gregory was born in Philadelphia and graduated from Princeton University. He completed a residency at the University of Pennsylvania and began his academic career in Missouri, where he served as professor and chair of urology at Saint Louis University before transitioning to private practice. In 2000, Dr. Gregory moved to Maine and joined Waldo County Hospital, continuing to practice urology for nearly two additional decades. He remained deeply committed to patient care and medical education, mentoring generations of trainees and colleagues, and practicing well into his 80s. Outside of medicine, Dr. Gregory was a passionate woodworker who spent countless hours in his workshop or building in his yard. He was an avid reader and a devoted member of the Episcopal Church, serving in lay leadership and teaching roles in both Missouri and Maine. He is survived by his wife, Sandy, three children, eight grandchildren, and two great-granddaughters.
1969
Charles “Chuck” Peterson, a physician-scientist whose work made foundational contributions to diabetes care, hemoglobin A1c measurement, and blood diseases, died June 10, 2025. He was 82. Born in New York City, Dr. Peterson earned his undergraduate degree from Carleton College and was awarded an international fellowship from the School of International and Public Affairs during medical school for research in Bolivia. He later trained in internal medicine, serving as chief medical resident at Harlem Hospital and Rockefeller University Hospital, where he spent 11 years on faculty. Dr. Peterson went on to serve as CEO of the Sansum Medical Research Institute in Santa Barbara and later as director of the Division of Blood Diseases and Resources at the National Heart, Lung, and Blood Institute in Maryland. His career also included senior leadership roles with the U.S. Army Medical Research and Materiel Command, industry, and telemedicine initiatives, as well as clinical service during the COVID-19 pandemic as medical director of an opioid use disorder treatment center. With more than 15 patents, his research advanced therapies for sickle cell disease and thalassemia; established hemoglobin A1c as the standard measure of long-term glycemic control; linked glucose control to improved pregnancy outcomes; developed widely used clinical assays; and pioneered early applications of atomic force microscopy to cellular biology. Remembered for his humor and loyalty to friends and family, Dr. Peterson is survived by his wife, Karen, two children, one stepson, and one grandchild.
1972
Thomas Shiftan, a physicianscientist and a founding oncologist of what became the Sidney Kimmel Cancer Center in San Diego, died Dec. 1, 2025, in La Jolla, California. He was 79. Dr. Shiftan was born in New York City to refugees of Hitler’s Germany and attended the University of Virginia. During medical school, he completed a threemonth tropical medicine rotation in Phebe, Liberia. He trained at the University of California, San Diego, followed by a hematology fellowship and a research year at the University of Innsbruck in Austria. He cherished that year for the connections he made with young residents, who sought out his guidance when they felt hesitant to approach their traditionally didactic superiors. He returned to practice in San Diego and served Sharp Memorial Hospital as chief of medicine, chair of the Oncology Advisory Committee, and medical director of oncology for nearly two decades. He was instrumental in the formation of the Sidney Kimmel Cancer Center, helping to integrate laboratory discovery and clinical trials and to expand patient access to experimental cancer therapies in the region. He was an enthusiastic athlete and a lifelong devotee of opera and the performing arts, serving on the boards of San Diego Opera and La Jolla Playhouse. He is survived by his wife, Maureen, two sons, and three grandchildren, who called him “Papageno,” the endearing bird catcher from Mozart’s “The Magic Flute.”
2012
Amanda Posner, a pediatrician, died Aug. 28, 2025. She was 43. Dr. Posner grew up in Scarsdale, New York, and earned a bachelor’s degree from Dartmouth College in 2004. She completed her residency in pediatric gastroenterology at UCSF Benioff Children’s Hospital. She served on the boards of Bay Area Young Survivors and the Norfield Children’s Center, extending her advocacy beyond the clinic. A talented performer, she acted and sang in college productions and with the Bard Hall Players at VP&S after appearing off- Broadway as a teenager and acting in the films “Welcome to the Dollhouse” and “The Door in the Floor.” Her humor, generosity, and authenticity left a lasting impression on those who knew her. She defied metastatic breast cancer by living life fully in the face of her illness for a decade. She is survived by her husband, Ben, one son, her parents, and her brother.
2014
Omoye “Oye” Enisegho Imoisili, an internist and public health physician who rose to the rank of commander in the U.S. Public Health Service Corps by the age of 35, died Nov. 17, 2025. She was 38. Dr. Imoisili was born in Richmond, Virginia. She enrolled in Princeton University at age 16 and earned a bachelor’s degree in psychology, followed by a research year at the National Institutes of Health. During medical school, she developed a keen interest in population-level health, pausing her MD studies to complete an MPH at the Johns Hopkins Bloomberg School of Public Health. Upon returning to VP&S, she was inducted into the Gold Humanism Honor Society for compassionate, patientcentered care. She completed residency training in internal medicine at Yale-New Haven Medical Center on the primary care track and was named Intern of the Year. Dr. Imoisili then served as an Epidemic Intelligence Service officer at the Centers for Disease Control and Prevention (CDC), followed by roles at the U.S. Food and Drug Administration and the CDC’s Division for Heart Disease and Stroke Prevention. In 2017, she was commissioned in the U.S. Public Health Service Corps and rose to the rank of commander in 2023, contributing to multiple national deployments, including the earliest phase of the COVID-19 response. A devoted Christian, she was also a lover of music and learned to play the piano and the violin. She visited 67 countries, all 50 U.S. states, and multiple territories. Having learned French and Spanish, she was studying Yoruba toward the end of her life. She died after a yearlong battle with cancer. She is survived by her father, Menfo, her mother, Bim, and her three siblings.
Gerald E. Thomson’96, Executive Vice President, Senior Associate Dean, and Champion for Underrepresented Students in Medicine
Gerald E. Thomson, a pioneering nephrologist who served as the double-endowed Samuel Lambert and Robert Sonneborn Professor Emeritus of Medicine at VP&S, died in February 2026. An honorary VP&S alumnus of the Class of 1996, Dr. Thomson received his undergraduate degree from Queens College following military service and earned his medical degree from Howard University College of Medicine. He trained at SUNY Downstate/Kings County Hospital, where he helped establish one of the nation’s earliest large-scale maintenance dialysis programs. His dedication to addressing disparities in health, health care access, and medical education arose from a deep commitment to justice and human rights that informed all his work, including the establishment of a dialysis program at Harlem Hospital Center, where he was director of medicine from 1971 to 1985. He served as executive vice president and chief medical officer of Columbia-Presbyterian Medical Center from 1985 to 1990. As a senior associate dean at VP&S from 1991 to 2002, he was a staunch supporter of students underrepresented in medicine, including Black and Latino Student Organization (BALSO) students, and founded the Gerald E. Thomson Undergraduate Pre- Medical Program to expand pathways into medical careers. His influence was felt beyond VP&S as a member of the National Academy of Medicine; president of the American College of Physicians; chair of the American Board of Internal Medicine; co-founder and president of the Society of Urban Physicians; and board member of Physicians for Human Rights. He is survived by his wife, Carolyn, two children, and two grandchildren.