SAN DIEGO — Several scientists have used embryonic or fetal stem cells to help rodents with spinal cord injuries walk again. The researchers travel the country showing videos of rats dragging their hind legs, followed by clips of them miraculously hopping around following stem-cell injections.
The question now, especially in the minds of the 250,000 people in the United States with spinal cord injuries, is: When will the research transfer into helping humans? The answer depends on who you ask. Some scientists believe it could happen as soon as the end of this year. Others say that’s too soon, and data from larger animals such as dogs or monkeys is necessary before researching with humans.
Evan Snyder of the Burnham Institute in La Jolla, California, is one of those video-toting researchers. Last week at a small stem-cell conference here, he showed the dramatic improvement (.mov) in rats he achieved in 2002.
Despite those positive results with rats, Snyder believes more work must be done before doctors try the experiment on humans. The controversy surrounding embryonic and fetal stem-cell research means the first human clinical trial using the cells will be under a microscope in more ways than one, he said. If something goes awry, opponents of killing embryos for research will be poised to quash future research.
“The last thing we need is another Jesse Gelsinger,” Snyder said, referring to the 18-year-old man who died during a gene-therapy trial at the University of Pennsylvania in 1999. After Gelsinger’s death, the Food and Drug Administration closed many gene-therapy trials around the country.
