Virginia-based HealthCentral, an online publisher of consumer health websites, said Wednesday that it acquired San Mateo-based Wellsphere, a publisher of health and wellness blogs and health information. Financial terms of the acquisition were not disclosed. Wellsphere will remain in San Mateo. Wellsphere was founded by graduates of Standford University Business School; the firm's CEO is Ron Gutman. HealthCentral is backed by IAC, Polaris Ventures, Sequoia Capital, The Carlyle Group, and Allen & Company.