Leonard Jarett, the  longest-serving chair in the history of the department of pathology and laboratory medicine at the University of Pennsylvania School of Medicine, died on January 13. He was 81.

Dr. Jarett assumed the chairmanship of Penn’s department in 1980 and in 1985 was named the Simon Flexner Professor and Chair. He held this position until 1998, when he became Distinguished Professor of Pathology and Laboratory Medicine. From 1984 to 1986 he served as vice chairman of the Medical Board at the Hospital of the University of Pennsylvania and from 1989 to 1990 he also served as associate dean for faculty affairs. He was internationally recognized as an investigator in the area of insulin action and was deeply committed to developing an integrated department that excelled in clinical service, excelled in both basic and applied research, and that excelled in teaching. A completely redesigned residency program was instituted early in his tenure as chair.

Dr. Jarett graduated from the Rice Institute in Houston in 1958 and received his MD (cum laude) from Washington University of St. Louis in 1962. He completed an internship in pathology at the Barnes Hospital in St. Louis, followed by an assistant residency, and became a trainee in Experimental Pathology in the department of biochemistry, Washington University School of Medicine. In 1964, he became a research associate, NIH, NIHLD, Laboratory Biochemistry, Section Cellular Physiology, in Bethesda, Maryland. Starting in 1966, he became an assistant professor in pathology at Washington University School of Medicine and was promoted to associate professor in 1969 and full professor in 1973. He also served as director of the Central Diagnostic Laboratories of Barnes Hospital until 1979.

In 1980, Dr. Jarett was appointed chair of the department of pathology at Penn, which was formally renamed the department of pathology and laboratory medicine under his leadership, emphasizing the integration of anatomic pathology and laboratory medicine and reflecting the department’s broader scope. From Washington University, he brought an extensive clinical and administrative background to the department and initiated a complete administrative reorganization. This resulted in improvements of the quality and turnaround time of results and increased consultative activity. Both anatomic pathology and laboratory medicine were computerized. Many collaborative clinical studies were initiated and inspections by the College of American Pathologists verified the high quality of the service provided by the department to the staff of the Hospital of the University of Pennsylvania. A measure of the quality of the service was the desire of several national laboratories or regional organizations to use the specialized services of the department for tissue typing, drug screening and toxicology, immunocytochemistry and in situ hybridization.

Dr. Jarett was also deeply dedicated to academic medicine, with a philosophy that involved training residents in clinical consultation, teaching and research, resulting in a program uniquely suited to train individuals for academic careers. Early in his tenure, he formalized previous decisions that the residency program change its emphasis from training for community hospital practice to training specialists for academic careers. His own research focused on metabolism and diabetes, where he investigated the mechanism of insulin action at the molecular level, the role of insulin internalization and nuclear translocation in the control of cell growth and gene expression. The very first paper he wrote as a first-year medical student in 1958 at Washington University became a Citation Classic. As a resident he showed that nonendocrine hormone-secreting tumors produce immunologically active ACTH. His work on the interaction of insulin with its receptor on the plasma membrane led to the theory that a mediator regulates the activity of key enzymes that control the metabolism of carbohydrates and lipids by altering the state of phosphorylation of these enzymes. For this work, Dr. Jarett was awarded the 1980 David Rumbough Award of the Juvenile Diabetes Foundation.

Dr. Jarett was the recipient of numerous other awards and accolades. He received the Cotlove Award of the Academy of Clinical Laboratory Physicians and Scientists in 1985 and its Gerald T. Evans Award in 1992. He received an honorary MA from the University of Pennsylvania in 1982. In 1990, Dr. Jarett earned the Alumni Achievement Award of Washington University School of Medicine. In 1995, the department established an Endowed Professorship in his honor. He received the Presidential Citation of the American Association for Clinical Chemistry in 1997, the Distinguished Service Award of the Association of Pathology Chairs in 1998 as well as the Luigi Mastroianni Clinical Innovator Award that year, and the prestigious “Gold-Headed Cane Award,” an award he was particularly fond of, in recognition of his long-term contributions to the field from the American Society for Investigative Pathology in 2000. He authored more than 150 original papers, served on editorial boards for nine journals, and published close to 30 books and chapters.

In 2001, Dr. Jarett won a Special Dean’s Award in recognition of his role as former chair (Almanac April 24, 2001). In the department, Dr. Jarett is remembered as an exceptional, generous yet exacting, and extraordinarily supportive mentor to an entire generation of academic pathologists in training and throughout their careers. Moreover, his tremendous talents in leadership, his ability to create a cohesive and integrated department, and his recruitment of outstanding and talented residents, fellows and senior faculty, leave a lasting legacy and have profoundly shaped the direction of the department to this day.

He is survived by his wife, Arlene K. Jarett; children Stacy Levitan (Jonathan), Douglas Jarett and Jennifer Jarett; and grandchildren, Jacob and Maya Levitan.

Contributions in his memory may be directed to the Parkinson’s Fund at Pennsylvania Hospital by visiting http://bit.ly/PDFundPAH, or please send checks to Penn Medicine Development and Alumni Relations, 3535 Market Street, Suite 750, Philadelphia, PA 19104.