Transplant revolution on way

A revolution in transplant medicine has begun following the successful culturing of embryonic stem cells, the material from which all types of human tissues grow.

Two separate research teams working at the University of Wisconsin-Madison in Wisconsin and at Johns Hopkins Medical Institutions in Baltimore, Maryland, managed to culture stem cells in the laboratory. These cell lines are now growing indefinitely and as they matured began to change spontaneously into muscle, nerve and bone cells.

Both teams derived their stem cell lines from embryonic tissues. It opens up dramatic possibilities, including the potential to culture replacement transplant tissues that would not be rejected by the recipient.

Dr James Thomson, a developmental biologist, who led the Wisconsin group, said: "Although a great deal of basic research needs to be done before these cells can lead to human therapies, I believe that in the long run they will revolutionise many aspects of transplantation medicine."

Although it will be years before we see grown-to-order organ replacements, scientists will quickly learn how growth factors and hormones make the stem cells change. This knowledge itself should help towards new medical treatments.

The research reports are published today in Science and in the Proceedings of the National Academy of Sciences.