Meet Our Board

Todd Guthrie, MD, PC


Dr. Todd Guthrie is a board certified orthopedic surgeon, practicing in Mt. Shasta, California. Dr. Guthrie sees AMEN as a catalyst to further facilitate the bringing together of the everlasting gospel of Revelation 14:6–12 and the Adventist health message. He firmly believes that medical missionary evangelism will open hearts in preparation for and in conjunction with the outpouring of God’s Spirit in the final days of earth’s history. Dr. Guthrie, his wife, Patti, and their four children have been involved for years in ministry in their local church and abroad.

Edwin Nebblett, MD


Dr. Edwin Nebblett currently practices family medicine, serving two small clinics in Catron county, New Mexico. His passion for sharing the principles of good health is surpassed only by his desire to live and share the practical gospel. Dr. Nebblett and his family regularly speak at churches and campmeetings, helping families to embrace Jesus Christ as an ever-present help in life’s challenges. Edwin is married to Maria; the couple have four young-adult children whose joy it is to engage in ministry with their parents.

Mark Ranzinger, MD

Past President

Mark Ranzinger is a board certified, minimally invasive surgeon currently practicing in Goshen, Indiana. Though Dr. Ranzinger has many honors to his credit, the aspect of his medical service that he values the most is his service as a missionary surgeon in Africa for seven years. What many do not know about Dr. Ranzinger, is that his undergraduate degree was in theology. Thus he has, since the beginning of his training, had a deep and abiding interest in combining the practice of medicine with the preaching of the gospel. Dr. Ranzinger considers himself blessed to be married to his wife Ruth, and they have three children - Andrew, Aubrey, and Elliot.

Lisa Walke, MD


Dr. Lisa Walke is board certified in Internal Medicine and Geriatric Medicine. She is an Associate Professor at the Yale University School of Medicine and Associate Chief of Geriatrics for Yale New Haven Hospital. Dr. Walke developed an interest in medical missionary work during her fourth year at the Mount Sinai School of Medicine but she did not act upon her interest until an appeal was made during the 2006 AMEN conference. As a result of her participation in AMEN, Dr. Walke has participated in short term missions to SDA Hospital, Ile-Ife, Nigeria and Hospital Adventista, Valle de Angeles, Honduras. She was also instrumental in organizing a medical mission trip to La Romana, Dominican Republic for Yale medical, nursing, and public health students. Having been inspired during several AMEN conference sessions to combine medical and gospel ministry, she has begun partnering with her pastor to conduct outreach efforts in Connecticut. Dr. Walke believes God will continue to use AMEN to empower and equip health care professionals to present a message of health and healing at home and abroad.