Christopher Calhoun, chief executive officer and director of Cytori Therapeutics, is retiring from the company, effective immediately. Dr. Marc Hedrick will succeed Mr. Calhoun, in addition to his current responsibilities as president and director. Mr. Calhoun will remain a director on Cytori’s board for the transition period, and will then assume the position of managing director, where he will focus on Cytori’s international business development efforts until his retirement on July 1, 2014.   ...