Denton Cooley 1960s. He and his colleagues worked on developing new artificial heart valves from 1962 to 1967; during that period, mortality for heart valve transplants fell from 70% to 8%. In 1969, he became the first heart surgeon to implant an artificial heart designed by Domingo Liotta in a man, Haskell Karp, who lived for 65 hours. The next year, in 1970, "he performed the first implantation of an artificial heart in a human when no heart replacement was immediately available." Cooley's interests included basketball, which he played in high school and as a three-year letterman for the UT men's basketball
Human artificial chromosome resulted in a human artificial chromosome that is mitotically stable. 21HAC was also able to be transferred into cells from a variety of species (mice, chickens, humans). Using 21HAC, researchers were able to insert a herpes simplex virus- thymidine kinase coding gene into tumor cells. This "suicide gene" is required to activate many antiviral medications. These targeted tumor cells were successfully, and selectively, terminated by the antiviral drug ganciclovir in a population including healthy cells. This research opens a variety of opportunities for using HACs in gene therapy. In 2011, researchers formed a human artificial chromosome by truncating chromosome 14.