More MS news articles for Nov 2001

Injections of pig cells bring hope to paralysed

October 28 2001
Roger Dobson
DOCTORS have transplanted foetal stem cells taken from pigs into the spines of six paraplegic patients in an operation designed to restore their movement.

The pioneering procedure offers hope to tens of thousands of people such as the Superman actor Christopher Reeve, who are paralysed as a result of accidents. Reeve is keeping a close eye on the experiment as his condition makes him suitable for the same therapy. During a debate on stem cell technology in America this summer, he described how the procedure could help him.

"I suffer from something called demyelination. That means that in one very small segment of my spinal cord the coating, myelin, which is like the rubber coating around a wire, has come off. That keeps signals from the brain from getting down into the body."

Stem cells, he added, could be cultured and injected into his spine to repair the site. "They would know that their job is to re-myelinate. And then the signals from the brain would go down properly, and I would get recovery of function."

The stem cells transplanted into the six patients have already started growing and, it is hoped, will soon bridge the myelin gaps in their spines.

Doctors are still monitoring progress in the patients, but John MacDonald, who leads the research at Washington University, said: "The changes that we are seeing are surprisingly impressive. Five years ago scientists said this was impossible. Now we know it is do-able. It is very exciting."

The operations completed this month follow extensive laboratory and animal testing. The therapy centres on a new technique for regenerating activity in the spinal cord by getting the stem cell to trigger the regrowth of myelin.

"It is about simple electrical conductance. Wire transmits better if it is insulated. The nerve fibres in the spinal cord need to transmit electrical signals but without the myelin wrapping the resistance is too big. The signal doesn't get through," said Jonathan Dinsmore, senior director of stem cell transplantation research at Diacrin, the biotechnology company that is co-ordinating the research.

The problem is that in people who have suffered paralysis, the myelin either does not grow, or it grows incorrectly.

The scientists are using foetal pig cells to grow into myelin and recoat the nerve fibres. Basic stem cells can grow into any form of human tissue, but the cells used in these operations have already developed into immature myelin cells. They are injected with tiny needles into the spinal cords of the patients at and around the damaged area.

"We chose people who were at least a year on from when they had become paralysed because we did not want to interfere with their own ability to recover," said MacDonald.

"It was carried out in the form of a back operation. We exposed the spinal cord at the level where we are going to transplant, then we use a special procedure to put the cells in. We gave up to 10 injections.

"Our aim is to help people regain important functions. If we can restore functions like bladder control and sexual functioning that would be really exciting."

Copyright 2001 Times Newspapers Ltd