• Digirad (Poway, California), a provider of cardiovascular imaging services and solid-state nuclear medicine imaging products to physician offices, hospitals and imaging centers, named Mark Casner CEO and a member of the board of directors. Casner joined Digirad last September as president of the company's Digirad Imaging Solutions leasing services subsidiary, and succeeds Gary Burbach, who will remain a member of Digirad's board. In addition, Peter Sullivan has been promoted to president of Digirad's product business. Sullivan joined Digirad as a consultant in January 2005 and was named senior vice president of operations in April 2005.

• John Hart has been appointed president and CEO of NiTi Medical Technologies (New York). Prevously, Hart held senior management positions at Stryker Orthopaedics and the Auto Suture Division of U.S. Surgical/Tyco Healthcare. NiTi has developed surgical devices for tissue closure, without the use of staples, based on clips and rings made of the shape memory alloy nitinol.

• Michael Centron was named vice president and CFO of Oxis International (Portland, Oregon). Prior to joining Oxis, Centron served as vice president, finance and administration and principal accounting officer of Large Scale Biology. Oxis International is developing technologies and products to research, diagnose, treat and prevent diseases resulting from oxidative stress.