A major physicians group in the California's San Fernando Valley, struggling with the rising cost of medical care, has joined another Southern California healthcare network that will now serve more than 600,000 patients, the Los Angeles Times reports. Lakeside HealthCare Inc., a medical group providing care for 200,000 patients through more than 1,800 staff and contract physicians, was acquired by Heritage Provider Network Inc. The financial terms were not disclosed, but the deal provided a needed infusion of cash to Lakeside, which was struggling with an unforeseen rise in medical costs, executives said.