Anita Arnold, MD: Dr. Arnold has been in practice for over 30 years as an internal medicine specialist. She practiced in Oxford, MS before joining UTHSC and then joined West Cancer Center for a combination of 16 years. Her experience with Threlkeld Infection Disease further expanded her mastery of diagnosis and testing. Dr. Arnold’s dedication to patient care and prevention is demonstrated as she works with patients and fellow providers.
Dr. Leah Tonkin, MD, MBA, DipABLM, is board certified in both Obstetrics & Gynecology and Lifestyle Medicine, bringing over 16 years of private practice experience in Memphis, Tennessee. On March 4, 2024, Dr. Tonkin joined Lifesigns—The Wellness Division of West Cancer Center— and was appointed Executive Medical Director in 2025.
Prior to her current role, Dr. Tonkin served as a hospitalist with Integrated Physician Services, providing emergent care in labor and delivery as well as gynecologic surgery. She was also a partner in a private OBGYN practice. Dr. Tonkin earned her medical degree and completed her internship and residency in Obstetrics & Gynecology at the University of Tennessee Health Science Center.
A dedicated fitness enthusiast and advocate for holistic health, Dr. Tonkin became board certified in Lifestyle Medicine to guide patients through the six pillars of health: Nutrition, Physical Activity, Stress Management, Restorative Sleep, Social Connection, and Avoidance of Risky Substances.
Dr. Felix Caldwell: Dr. Caldwell is a native Memphian and graduated Cum Laude from Vanderbilt University. He received his medical degree from The University of Tennessee Health Science, Chattanooga. Dr. Caldwell is Board Certified in Internal Medicine and is a fellow in the American College of Physicians. Following medical school, he served as Lt. Commander in the United States Naval Reserve with an Honorable Discharge. He enjoys gardening, hiking, going to movies, taking care of his three dogs and aquarium. Dr. Caldwell has practiced medicine for almost 40 years and has worked for Lifesigns since 2006.
Margaret Mitchell, DNP, FNP-C: A native Memphian, Maggie graduated Summa Cum Laude from the University of Memphis and earned her Doctorate of Nursing Practice from the University of Tennessee Health Science Center. As a nurse, she worked in primary care with Le Bonheur Pediatrics and following her NP program, she worked in Nashville as a Family Nurse Practitioner. Maggie has served as a Tennessee Promise Mentor and is on the UTHSC Honor Council; she has participated in the Nursing in Diverse Cultures program in Ecuador and is a member of Sigma Theta Tau Honor Society of Nursing. She lives in east Memphis with her husband, David, their daughter, Elizabeth, and two pups, Ruthie, and Gus.
Lachre Brown, NP has a heart to serve. She knew that a healthcare career was God’s destiny for her. Lachre began her nursing journey at Southwest Tennessee Community College, where she graduated Magna Cum Laude as valedictorian of her class. She graduated from Union University and earned a Master’s degree in Family Medicine. She is a member of Sigma Theta Tau International Honor Society of Nursing and The Greater Memphis Association of Advanced Practice Nurses. Her work experience includes hospice care, acute care, travel health, occupational health, and primary care. Her heart for missions led her to help bring healing to Haiti after the massive earthquake in 2010. She also devoted her nursing skills on a mission trip to the Dominican Republic. Lachre enjoys international travel and serves as a Sunday School teacher and trustee board member at her local church.