Set aside, for one moment, Highmark's ongoing contract dispute with UPMC and assume the health insurer's plan to acquire the West Penn Allegheny Health System gets all the regulatory approvals. What happens then? Drowned out by all the heated charges and countercharges is the fact that Highmark is breaking new ground -- none of the other 38 Blue Cross Blue Shield independent licensed companies across the U.S. has ever purchased a health system before, and experts are hard-pressed to remember a major U.S. insurer buying an entire health system anywhere. "They are merging two different cultures -- one whose sole purpose is to minimize costs and one whose sole purpose is to provide more medical services," said James McTiernan, principal and co-founder of the Downtown employee benefits firm Triad USA.