• James Williams has been appointed president and chief operating officer of the Americas region of International SOS (Philadelphia). Williams began his tenure with the company in 1994 when he held a series of regional leadership positions in operations for SOS in Indonesia and Southeast Asia. He later was executive vice president and general manager of SOS Americas. International SOS is a medical and security assistance company, as well as a leading provider of remote site medical services.

• Dixon Thayer, a member of the I-trax (Chadds Ford, Pennsylvania) board of directors, has been named CEO. Frank Martin, who has served as the company's chairman and CEO since the merger of I-trax and CHD Meridian Healthcare in March 2004, will remain as chairman and play an active role in strategic business development, shareholder relations and key client relationships. Thayer has been on the I-trax board since April 2003. He most recently was the founder and senior partner of ab3 Resources, a strategic consulting and private equity investment company. I-trax is a provider of integrated health and productivity management solutions.

• Jelle Kylstra, MD, will serve in the newly created position of vice president and medical director for RITA Medical Systems (Mountain View, California). Kylstra has more than 14 years of experience in both pharmacology and medical devices across multiple therapeutic areas. Kylstra most recently held the position of vice president, clinical development at Light Sciences. RITA Medical manufactures products for cancer patients including radio frequency ablation systems for treating cancerous tumors as well as percutaneous vascular and spinal access systems.

• Michael Mogul has been appointed president of Stryker Orthopaedics (Kalamazoo, Michigan). Since 2000, Mogul has been managing director of Stryker Germany, Austria and Switzerland, where he led the rebuilding of those organizations following the Howmedica acquisition. Stryker also named Jeffrey Paulsen executive vice president, Stryker Orthopaedics and International. Paulsen formerly was president of Stryker Orthopaedics.

• Triad Hospitals (Plano, Texas) CFO Burke Whitman, a reserve officer in the U.S. Marine Corps, will be recalled to temporary active military duty in March, probably for service in Iraq, with an expected return to the company in 4Q05. The company said it expects Whitman to remain involved in its strategic and other significant decisions through electronic and telephonic communications, and other officers will conduct the company's day-to-day business while Whitman is away. During his absence, the company plans for senior vice president and controller W. Stephen Love to serve as acting CFO and for chairman and CEO James Shelton and director of finance and investor relations Laura Baldwin to lead its investor relations activities. Triad Hospitals, through its affiliates, owns and manages hospitals and ambulatory surgery centers in small cities and selected larger urban markets.

• Marc Miller has been promoted to vice president of Universal Health Services (King of Prussia, Pennsylvania), responsible for operations at the Eastern region acute-care hospitals. Miller most recently was division vice president, acute care, Eastern region. Universal Health Service operates acute-care and behavioral health hospitals, ambulatory and radiation centers nationwide, in Puerto Rico and France.

• Michael Singer has resigned as head of research and development for the WebMD Practice Services unit of WebMD (Elmwood Park, New Jersey). Tim Staley, senior vice president, research and development, at WebMD Practice Services, who had reported to Singer, will assume Singer's responsibilities. WebMD is a provider of healthcare information for physicians, consumers, providers and health plans.