ENGLEWOOD - A skid into a tree, a bad fall on an icy mogul, a fall from a roof - it takes just a second to turn a healthy person into a quadriplegic or paraplegic.

For thousands of years, a severe spinal cord injury meant certain death. For much of the last century, it meant a painful year or two before the grip of death.

For the past 40 years, it has meant life in a wheelchair, with pressure sores, no control of vital organs and no feeling below the point of injury.

But now there is a glimmer of hope that at least partial feeling can be returned to those with spinal cord injuries and that some can rebound enough to have some control over their limbs.

Newly paralyzed people from across the country are making the pilgrimage to Craig Hospital, hoping an exotic new procedure can restore feeling to their toes, feet, arms and legs.

Craig is the only hospital in the United States certified to conduct the trial operation, which uses the body's own cells to stop nerve deterioration soon after a spinal cord injury.

Although it's unlikely the procedure will enable any of the trial patients to walk on their own again, most are expected to get some feeling back in their limbs. They also may regain some bladder control or enough body movement to relieve pressure wounds caused by wheelchairs and beds.

"Help is on the way - it really is," said Christopher Reeve, the long-paralyzed actor and activist for those with spinal cord injuries. Reeve was referring to the research by Proneuron Biotechnologies Inc., of Tel Aviv, Israel.

Proneuron pioneered the process, performing the first trials in Israel in 2000. It chose Craig, considered one of the top five rehabilitation hospitals in the U.S., to be its first American partner.

Wound-healing cells

In simplest terms, "We educate the cells to start the wound-healing process," said Nir Nimrodi, a Proneuron researcher stationed at Craig.

The body has special wound-healing white blood cells called macrophages, which are abundant in the skin, liver, kidneys and blood, he said. They eat bacteria and fix our injuries.

Unfortunately, macrophages are in short supply in the the spinal cord and the brain. They also work less efficiently in those areas.

But Dr. Michal Schwartz of the Weizmann Institute in Rehovot, Israel, theorized that spinal cord injury victims might be helped by injecting macrophages from elsewhere in the body into the spinal cord at the site of the injury.

Proneuron Biotechnologies worked with Schwartz to come up with a way to isolate macrophages and combine them with skin cells in a way that multiplies their number and power, said Nimrodi.

The first trial began in Israel in 2000. Eight patients were injected with the supercharged macrophage cells and three of them regained significant feeling, 10 times greater than by chance alone.

Normally, people with complete spinal cord injuries - where the cord is severed or so damaged that there is no feeling or ability to move below the injury - have only a 3 percent chance of regaining any significant feeling in the toes or limbs.

One of those first eight patients, and the first to undergo the treatment, was a Colorado woman, Melissa Holley, of Ridgway, who was badly injured in a car accident on June 25, 2000.

Holley, now a 22-year-old college student, cannot walk unaided, but she can shuffle her legs to help get herself from her wheelchair to the bed and elsewhere. She said recently she has "feeling pretty much everywhere."

Nimrodi calls Holley "a great success story, but not our best."

A patient who fell from a roof and was a quadriplegic now can walk in water with help from therapists, he said.

Those successes were enough to convince the U.S. Food and Drug Administration to approve a larger human trial in this country.

Two-week window

The trials have just begun at Craig, where officials won't say how many patients have undergone the procedure. To protect the study's scientific validity, it's best if even doctors don't know details of the study, including which patients have received the injections and which have been given placebos.

But they will talk about how the program works:

To be effective, the macrophage cells must be injected within 14 days of the accident.

Immediately after an injury, if the responding doctor knows of the Craig-Proneuron study, he or she makes contact and an initial screening is done. The patient must have a complete spinal cord injury, be between 14 and 65, and cannot have had a blood transfusion within the previous 36 hours.

If the patient passes that hurdle, then he or she goes to Craig for additional screening. If doctors think the patient is a good candidate for the trial, they harvest some blood and skin. The blood and skin are moved to a clean room, where isolating the macrophage cells takes 36 hours.

When all is ready, the patient and the cells are taken to an operating room at the adjacent Swedish Medical Center. Craig neurosurgeon Dr. Scott Falci injects the macrophage cells at numerous sites along the injured spine.

Building momentum

Craig, known for its expertise in spinal cord injuries, has sent notices about the trial to trauma doctors and neurosurgeons across the country, said Craig Hospital President Dennis O'Malley.

But he knows that most referrals originate with family members who got on the Internet as soon as their loved one had the accident.

"They're likely to come across this trial in the first 10 minutes of their search," O'Malley said. "Once we get a little momentum and the word starts to spread, we hope to enlighten the trauma community" about macrophages' potential, O'Malley added.

Craig is one of 13 regional model facilities for spinal cord injury, as designated by the federal government, and has treated more people with spinal cord injuries than any other facility in the nation.

Craig Hospital also is working with the Karolinska Institute in Sweden on stem cell research, hoping those cells can actually reconnect damaged spinal cords in people with older injuries.

The Proneuron study doesn't use stem cells, so it isn't caught in the controversy over whether cells from aborted fetuses should be used for medical research.

Nimrodi said it would be irresponsible to make promises to the Phase II patients that they'll be able to walk again. On the other hand, he won't rule out greater strides down the road.

"I'm an optimistic person," Nimrodi said. "I'm not willing to accept that someday people getting these injections won't be able to walk a mile."