• Arrowhead Research (Pasadena, California) reported the addition of three executives to its management team: Thomas Haag, PhD, chief patent officer; Mark Tilley, PhD, VP of advanced materials; and James Hamilton, MD, VP of medical technologies. Tilley previously was senior investment manager at DSM. Haag was with the Washington offices of Kenyon & Kenyon and McDermott Will & Emery. Hamilton is a cofounder of NanoValent Pharmaceuticals. Arrowhead Research is a nanotechnology company.

Robert Gontarek was named COO of Diagnostic Health (DHC; Birmingham, Alabama), effective Monday, May 19, 2008. Gontarek most recently was executive VP of operations for CBIZ Medical Management Professionals. DHC is an independent provider of diagnostic imaging services.

Bernie O'Rourke was named executive VP/COO of InSight Health Services Holdings Corp. (Lake Forest, California). O'Rourke has been senior VP/GM, Eastern Division of InSight since March 2006. InSight is a provider of diagnostic imaging services.

• Leerink Swann (Boston) has named Stephen Weiss as senior managing director, head of institutional equities, and promoted John Sullivan to the role of director of research. Weiss was previously co-head of institutional sales and a senior managing director for Leerink Swann. Sullivan joined Leerink Swann in 2004 as an equity research analyst in the life sciences tools and consumables sector. Leerink Swann is a healthcare-focused investment banking firm.