1.   But pig tissue has its own drawbacks because some scientists worry that pig viruses can be transferred to people.

2.   Processed pig tissue is already used by companies such as Medtronic Inc. and St. Jude Medical Inc. to make replacement valves for heart patients.

3.   During the surgery doctors determined that repair to the damaged heart valve was too difficult and decided to repair the leaking valve with pig tissue.

4.   New Zealand said Monday it opposes a plan by the Cook Islands to allow pig tissue to be implanted into humans as a possible cure for diabetics.

5.   The concern has been that if pig tissues are transplanted to people, this viral DNA might make viruses that will infect people.

6.   In addition, surgeons have already gained a decade of experience in using pig tissue, using heart valves in human cardiac surgery.

7.   New Zealand company Diatranz Limited had approached the Cook Islands government to begin trails on the diabetes treatment, in which pig pancreatic tissue is transplanted into humans.