General Medical Clinics Plc (GenMed) has bought rival walk-in primary care provider Medicentres (UK) Ltd out of administration, doubling the size of its portfolio.Healthcare Market News (COMPANY NEWS) August 2011The PLUS SX listed company paid £738,000 in cash for the business, which operates at walk-in centres at Paddington Station, Victoria Station, Eldon Street (London EC2)…