Craig Hospital in Englewood may become the first place in the world to transplant human stem cells into paralyzed patients in hopes of helping them regain mobility. The hospital is in a race with the University of Miami Hospital to pioneer the procedure, and could begin human trials as early as 2004.
Could this mean movie star Christopher Reeve and thousands of others now in wheelchairs will walk again some day? An emphatic maybe, say the neurosurgeons at Craig Hospital and the scientists at the Karolinska Institute in Sweden. What seemed impossible five years ago now has the feel of reality. Patients at Craig, a Rehabilitation and research hospital, would receive human stem cells for the purpose of reconnecting damaged spinal tissue. Craig is working in tandem with the Karolinska Institute in Sweden, which teamed with Craig’s Dr. Scott Falci five years ago to perform the world’s first embryonic spinal cord transplant. The goal that time wasn’t to restore movement to paralyzed people, but to prevent deterioration of their conditions. “Our goal was to fill the cavities and cysts with fetal spinal cord tissue,” Falci said. The tissue, from aborted fetuses, stabilized the spinal cords and showed no signs of rejection. Since then, stem cells – primitive cells from embryos, fetuses or fertilized eggs – have emerged as the hope for regenerating tissue. Craig’s relationship with Sweden proved fortuitous last year when President Bush announced that only existing stem cell lines could be used for federally funded medical research, like the work planned at Craig. About 40 percent of all existing stem cell lines are in Sweden, making the Karolinska Institute, Sweden’s largest medical research center, among the best places in the world to do such research. And when Karolinska’s Dr. Claes Hultling, who is a quadriplegic himself, visited 100 prominent centers to find a partner eight years ago, he chose Craig because it had the best clinical care, said Dr. Daniel Lammertse, medical director at Craig. A lot of spinal cord research is being done internationally. In fact, five spinal-injury patients already are getting stem cells elsewhere – just not from humans. The Albany Medical Center and Washington University of St. Louis are collaborating on a trial using stem cells from pigs. No results have been announced, but initial results have displayed no viruses from the cross-species injections. Stem cells are crucial to the process because they haven’t yet decided what kind of tissue they’re going to be, so are much more pliable than more mature cells. The reason scientists have so much hope for a cure is the amazing ability for stem cells to follow a route from the uninjured section of the spinal cord to the injured section, laying connective tissue the whole way. Stem cells seem to know how to migrate up and down the spinal cord and make connections, Falci said. “We believe connections can be made from above to below. It may not be same as when they were born – it may be a learned thing – but new connections can be made.” He knows because Karolinska already is having success with rats. First, researchers harvest stem cells from fertilized eggs or embryos. Then, they grow them in a petri dish to see what kind of nerve cells they become. “We can sort of push them in different directions,” Falci said. The most promising stem cells are injected into rats. After the rats die, an autopsy of the spinal cord determines where the connections have been made. In rats, “the stem cells are surviving at the injury site,” Falci said. “They’re moving into normal tissue above and below and making connections to nerves that are functioning in the spinal cord. That’ s all good stuff.” The next round will be to see if they can get rats to walk again. With humans, it will be trickier because the repair work will be greater, and the gaps in knowledge are wider still for those who were injured years ago. Still, “If there’s viable track from the head on down, the stem cells know how to migrate,” Falci said. Craig has the best database of living spinal-cord patients in the world, Falci said. That’s crucial because knowing where connections were weakest and strongest at the time of the injury will help doctors know where to inject the stem cells to bridge the gaps. Already, their work with petri dishes and rats has uncovered an irony: Trying to regenerate tissue too soon after the injury may be counterproductive. It may take several months after the injury before injecting stem cells is safe. Melissa Holley of Ridgway had been injured for two weeks when she became the first spinal-cord patient in the world to get an injection of specialized white blood cells to restore sensation in her legs. The procedure, in Tel Aviv, Israel, was successful enough to spark her interest in even more revolutionary procedures. “I have feeling pretty much everywhere, which is something I’m very thankful for,” Holley, 20, now a student at Harding University in Arkansas, said. “I’m not quite strong enough to get up and do jumping jacks, but after having nothing, I’ll take anything.” Holley can shuffle her legs to help herself move from, say, the wheelchair to her bed. She lifts weights everyday to keep in shape. She doesn’t spend all her time picturing herself walking again. “After an accident, you have to live in the here and now,” said Holley, who was injured in 2000 in an automobile crash. “You have to accept the day-to-day struggle you have to go through just to get up in the morning. “But at the same time, you want to look at the light at the end of the tunnel.” So, she keeps track of the Craig-Karolinska research. “It’s encouraging,” she said. “Stem cells are so versatile. Especially when you’re talking about human trials. That’s when you get to see if it’s really worth it. “I certainly wouldn’t discount the possibility of walking again. There’s so much hope. “I’d love to be a guinea pig again.”
INFOBOX
Repairing damaged spinal cords
Researchers are hoping to help patients regrow damaged neural tissue by injecting them with stem cells. The process would be a step toward restoring lost feeling and Motor control. 1. At the time of the injury, doctors make a map of the strengths and weaknesses of the spinal cord. 2. Researchers remove stem cells from the petri dish where they are cultivated and inject them into the patient. 3. Researchers hope that the stem cells will migrate to the damaged area, and begin to grow into nerve cells. 4. If the stem cells regenerate the damaged spinal cord, researchers hope that the new cord will be able to carry signals to and from the brain, restoring feeling and motor control.
Englewood Hospital Could Be First In World to
Transplant Them In Paralyzed Patients
Date: 04-29-2002; Publication: Denver Rocky Mountain News; Author: Bill Scanlon
Source: The Concise Encyclopedia of the Human Body
