• Gary Fredericks was named VP of corporate accounts for Alphatec Holdings (Carlsbad, California). Prior to joining Alphatec, Fredricks was VP of corporate accounts and channel development for Aesculap. Alphatec Holdings makes products for the surgical treatment of spine disorders.

• Peter McAree was promoted to senior VP and CFO of Caliper Life Sciences (Hopkinton, Massachusetts) from VP of finance. Thomas Higgins will step down from the position of CFO. Previously, McAree was CFO of Zymark prior to that company's merger with Caliper in 2003. Caliper Life Sciences makes technologies enabling researchers in the life sciences industry to create and enhance medicines and diagnostic tests.

• Dan Reifsteck has been appointed CEO of the Ximedica subsidiary of the Item Group (Providence, Rhode Island). Reifsteck was recently the head of global services for IT solutions for Agfa (formerly Heartlab). Ximedica is a contract design, development and manufacturing company specializing in capital and disposable medical devices and instruments.

• Gregory Adams was named president of the Northern California region for Kaiser Foundation Health Plan (Oakland) and Kaiser Foundation Hospitals (also Oakland) named Bernard Tyson executive VP of Kaiser Permanente hospital and health plan operations. Adams has more than 25 years of experience as a senior healthcare executive and consultant, and he has been with Kaiser Permanente since 1999.

• Charles Kelly was named CFO of Medical Action Industries (Hauppauge, New York). Prior to joining Medical Action, Kelly was CFO with Chem RX. Medical Action Industries is a supplier of medical and surgical products.

• OptiMedica (Santa Clara, California) has named Robert Eno and Robert Haddad to the new positions of VP of marketing and VP of operations, respectively. Eno joins OptiMedica from NeoGuide Systems, where he served as VP of marketing. Haddad was VP of international operations and business development at Elkin Medical Systems. OptiMedica is an ophthalmic device company.

• Mark Nosacka has been appointed CEO of Tenet Healthcare's (Dallas) Good Samaritan Medical Center, a 333-bed, acute-care facility located in West Palm Beach, Florida. Nosacka most recently was president and CEO of Community Health Partners. Tenet Healthcare owns and operates acute-care hospitals and related ancillary healthcare businesses, which include ambulatory surgery centers and diagnostic imaging centers.

• Lawrence Covington was named CEO/chairman of Unibased Systems Architecture (Chesterfield, Missouri), which specializes in healthcare information technology.