August 2001: CHICAGO (Reuters) - A plastic tube filled with chemicals and wrapped snugly around the severed spines of rats provides nerves a "bridge'' on which to regrow and give the animals some mobility, Canadian researchers said on Tuesday.

In experiments, researchers at the University of Toronto found the rats regained as much as half their normal movement, depending on the chemicals used.

"We saw some directed nerve tissue growth along the plastic tube, but we do not yet know if the severed nerves were connected to the newly grown tissue,'' said Molly Shoichet, who presented her findings at a meeting of the American Chemical Society.

"We hope that once axons grow across the gap they will make the appropriate connections,'' she said, adding that experimenting with the technique on humans was far off.

The small tubes, made from the same material used for soft contact lenses, mimic the spine's flexibility and fit snugly around the injured area. The tube serves as a "bridge'' for nerve growth, Shoichet said.

Unlike nerves elsewhere in the body, which regenerate rapidly after an injury, nerves in the spinal cord must be stimulated to promote growth. Other researchers have experimented with injections of growth factors and genetically modified cells, but there is no standard treatment to reverse spinal cord damage.

An estimated 10,000 Americans suffer spinal cord injuries every year, notable among them actor Christopher Reeve.