21.   The human embryonic stem cells whose first isolation was reported last November have been seen as a promising source of new tissue.

22.   They said they would continue to examine the new tissue and also look for evidence of it in animals.

23.   Tissue engineering involves transplanting cells onto synthetic forms where new tissue is generated.

24.   Perhaps giving the xenotransplant patient some bone marrow taken from the same pig that provides the organ will make the immune defenses tolerate the new tissue.

25.   Petersen said that in new experiments he already has shown that injecting the special marrow cells into rats causes the animals to form new liver tissue.

26.   Petersen said that his research investigated how some people with liver failures are able to grow new liver tissue.

27.   But Petersen said that some patients who do not make new hepatocytes still end up growing new liver tissue and recovering.

28.   Chiu said the new tissue quickly began to work with the original heart cells, beating in unison.

29.   Dr. Philippe Menasche of Bichat Hospital in Paris said the man has improved dramatically, and the new tissue in his heart is contracting rhythmically.

30.   High-protein, high-calorie diets have become part of treating a burn victim, who needs the nutrients to fight infection and grow new tissue.