xenotransplant

The proposal urged researchers to document carefully an animal's breeding history and preserve blood samples from each animal used in a xenotransplant.

The world's first human-rabbit xenotransplant.

The animal transplants, which are known as xenotransplant, include seven baboon kidneys and two baboon hearts.

Dr. Sachs cautiously predicted that a pig-to-human xenotransplant would be attempted in less than a decade, and possibly "in a couple of years."

The first "whole organ" xenotransplant will attract intense press coverage, giving whoever conducts it free publicity, not to mention a spot in the medical history books.

No xenotransplant recipient has been known to have developed a novel type of infection, but those people were not monitored as closely as Mr. Getty is.

And one prominent xenotransplant expert, Dr. Fritz Bach, of Harvard University, who is a paid consultant to Novartis, has called for a national commission to study the risks.

The proposed Federal guidelines are expected to put primary responsibility on the researchers carrying out a xenotransplant and to demand that they gain approval from an independent committee, which has not been precisely defined.

"You can increase the doses of immune suppressants and get a xenotransplant to take, but that's not practical," said David H. Sachs, a professor of surgery and immunology at Harvard University Medical School as well as the director of transplantation biology at Massachusetts General Hospital.