I used to work at the Oak Street campus. Both the Winslow street building and the Oak Street building were purchased by Children's hospital, then leased back to TriHealth (of which Bethesda Oak was a part of). The buildings are used by Trihealth for administrative functions, such as executive offices, IT, etc. Childrens Hospital then leases back portions of the buildings for their own purposes from Trihealth (at least this was the case a year or so ago).
As for the fences - while I was there a co-worker was car jacked in front of the Winslow street building. I believe another co-worker was robbed as well. They aren't pretty, that's for sure, but they were put in for a reason.