Davies` work does not focus on remyelination, a technique of other stem-cell researchers to restore Myelin, a substance that protects nerve cells, in the Central Nervous System. Instead, he focused on changing the structure of the injury site itself. The transplanted cells may have also encouraged uncut nerve fibers around the injury to promote new connections.

The GRPs are of great interest, and the study reaffirms they are an attractive method for repairing spinal-cord damage, said Dr. Wise Young, a neuroscientist and director of Rutgers University`s W.M. Keck Center for Collaborative Neuroscience.

'This is going to create a lot of excitement in the field,' he said of Davies` work.

Young, a pioneer in treating spinal-cord injury, has organized clinical trials in China, where he plans to test the influence of umbilical-cord blood stem cells in the central nervous system.

'The paper shows very compelling data for moving GRPs to clinical trial as soon as compatible human cells can be obtained,' Young said.

But first, researchers would have to overcome a huge obstacle: the lack of availability of stem-cell lines in the United States. It would take hundreds of thousands of the GRP cells to act in a person, Davies said.

Even so, this could be a short-term dilemma: Young said he is confident that it won`t be long before scientists can make any cell into a stem cell.

'A stem cell is just a cell expressing certain genes, and there`s nothing more mysterious than that. We just have to know what the genes are,' he said.

Davies plans to continue researching the effect of GRPs on rats.

'We have a 40 percent efficiency in (repairing) nerve fibers. I want to see more than 90 percent,' he said.

Eventually, Davies hopes the new technology can be used to repair central nervous system injuries in people in the future, as well as other neurogenerative diseases.

Copyright 2006 by United Press International