Robert Jarvik animal in the lab for 10 days. Kolff assigned Jarvik to design a new heart that would overcome the problems of the Kwan-Gett heart, eventually culminating with the Jarvik-7 device. In 1982, the team carried out an artificial heart implant - the second ever, 13 years after Domingo Liotta and Denton Cooley's first in 1969. William DeVries first implanted the Jarvik-7 into retired dentist Barney Clark at the University of Utah on December 2, 1982. Clark required frequent visits to the hospital for the next 112 days, after which he died. During frequent press conferences to update the patient's condition,
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.