Dutch business publisher Wolters Kluwer has bought out UpToDate, a Waltham, MA-based online medical information company, for an undisclosed amount, though it is likely in low hundreds of millions.

UpToDate, founded in 1992, runs a service in which doctors and other medical professionals write articles summarizing the latest thinking on best clinical practices, which are available via a premium subscription service online as well as on mobiles. The company, which has about 250 employees, is expected to generate $80 million in revenue this year, according to the company, and has information which is used by 320,000 doctors and other medical workers in 130 countries, it says. More details in release.