Two powerful healthcare unions are slugging it out over the future of a chain of six struggling Catholic hospitals in California, including two in Los Angeles County. California Atty. Gen. Kamala D. Harris is scheduled to decide this week whether to permit the sale of the Daughters of Charity Health System and its six nonprofit hospitals to for-profit Prime Healthcare Services Inc. of Ontario. Among the six hospitals are St. Francis Medical Center in Lynwood and St. Vincent Medical Center near downtown. Members of the California Nurses Assn. and the SEIU-United Healthcare Workers West are on opposite sides of the proposed $843-million sale – and their debate intensified on Tuesday.