Tuesday, April 24, 2007

Simple Injection Shows Promise for Treating Paralysis

Paralyzed lab rodents with spinal cord injuries apparently regained some ability to walk six weeks after a simple injection of biodegradable soap-like molecules that helped nerves regenerate.

The research could have implications for humans with similar injuries.

"It will take a long time, but we want to offer at least some improvement, to improve quality of life for people with these injuries," materials scientist Samuel Stupp at Northwestern University in Evanston, Ill., told LiveScience. "Anything would be considered a breakthrough, because there's nothing right now."

The soap-like molecules contain a small piece of laminin, a natural protein important in brain development. After these molecules are injected into the body, they react with chemicals there, assembling themselves instantly into scaffolds of super-thin fibers just six billionths of a meter wide, roughly a hundredth a wavelength of orange light. They biodegrade after roughly eight weeks.

The scientists experimented with their molecules on dozens of mice and rats that experienced spinal cord injuries that paralyzed their hind legs, "the kind of very hard blow people might experience after falling off skiing slopes or getting in car accidents," Stupp said. His colleague, neurologist John Kessler, became active in this work after Kessler's daughter was paralyzed in a skiing accident.

After six weeks, damaged nerves regenerated enough for the paralyzed legs of the rodents to regain some ability to walk.

"There's a special scale to monitor how much function they regained, ranging from 0 to 21," Stupp explained. "At 21, function is perfect. At 6 or 7, limbs are just paralyzed, and the mice were just dragging them along. If you go to 9 to 12, the animal can now actually move the limbs. Not perfectly?awkwardly?but they move. So two or three points on that scale makes a huge difference."

"We've been able to go from a 7 to a 9 in the mouse, and in the rat, the highest was 12," he said. The findings are to be presented today at a meeting of the Project on Emerging Nanotechnologies in Washington, D.C.

The researchers are currently in talks with the FDA regarding their work and hope to start phase I clinical trials (for toxicity and safety testing) in humans two years from now, Stupp said. The idea he and his colleagues have for these molecules is to administer them within a day or so after spinal cord injuries, before scar tissue begins to form that can suppress healing. Past experiments have shown these molecules can actually turn neural stem cells (which might otherwise become scar cells) into neurons instead.

"Recovering every function a person had before an injury will probably be very hard," Stupp cautioned. "Even if people couldn't walk, if they could recover bladder function, that'd be a good thing. It's the first thing I'd want to recover."

The researchers now are developing versions of these soap-like molecules that could help with regeneration when it comes to other maladies such as Parkinson's disease, stroke, heart attacks, bone trauma or diabetes.

By Charles Q. Choi

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Wednesday, April 18, 2007

Drug Shows Promise in Spinal Cord Injury Treatment

A drug called Cethrin shows promise in treating people with spinal cord injury (SCI), according to a study by American and Canadian researchers.

Cethrin inhibits Rho, a signaling master switch that, when activated, triggers cell death and increases damage after SCI. Tests in animals with SCI have found that Cethrin inhibits cell death and promotes neural regeneration.

This one-year study looked at the use of Cethrin (a recombinant protein) formulated with a fibrin sealant in 37 patients who had just suffered an SCI that left them with no sensory or motor function below the area of the injury.

All the patients had an "A" grade injury as ranked by the American Spinal Injury Association (ASIA). Grades of injury go from A through E. An "A" is the most serious while "E" is normal.

After the patients had surgical decompression/reconstruction, the researchers started treatment with Cethrin, an average of 53 hours after the injury occurred. The patients received increasing doses of the drug (0.3, 1.0, 3.0 and 6 milligrams) administered extradurally to the injured spinal cord. The patients were assessed at various points over a year.

The study found that at six weeks, 30.6 percent of the patients improved by one or ASIA grades of injury. At six months, 28 percent of patients improved by one or more ASIA grades. Five patients improved to "C" and two improved to "D." One patient died from acute respiratory distress syndrome.

The study, which was funded by BioAxone Therapeutique of Montreal and Boston Life Sciences Inc., was presented Monday at the annual meeting of the American Association of Neurological Surgeons, in Washington, D.C. The findings from this Phase I/II study warrant moving on to a prospective randomized trial of Cethrin, the researchers said.

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Monday, April 09, 2007

Hospital Tests New Surgery

Baumont procedure could improve bladder control

What does it take to import a medical procedure from China to Detroit?

In a reversal of the globalization seen in many industries, doctors from Beaumont Hospital in Royal Oak this week began a pilot study, under the watchful eye of the Chinese surgeon who developed the operation, that could help millions of Americans regain bladder control after spinal cord injuries and spina bifida, one of the most common and disabling birth defects.

Beaumont's team will perform the procedure on seven children and one adult with spina bifida, all but one of whom are from outside Michigan, evidence of the far-reaching appeal of the technique.

Then the team will wait one to two years to see if new nerve paths created in the surgery restore continence in the patients. Only then would the study be resumed.

Spinal cord patients, some 260,000 in the United States alone, and another 70,000 Americans who live with spina bifida await results.

The surgery creates a neural connection that signals the bladder to empty when a person touches the thigh, said Dr. Chuan-Gao Xiao, who practices at Huazhong University of Science & Technology in Wuhan, China.

If successful, the operation might save billions of dollars in lifelong costs related to incontinence and infection.

"We have over 200 children from all over the country who want this done and we have no other money right now," said Dr. Kenneth Peters of Beaumont's urology team and head of the team that traveled to China to learn the surgery. Applications poured in after the first three surgeries were performed at Beaumont in December on two people with spinal cord injuries and one with spina bifida. Without federal or private research grants that pay for many studies of investigational procedures, Beaumont had to find a donor.

J. Peter and Florine Ministrelli of West Bloomfield, who have given $15 million to the hospital for urology and cardiology research, will pay for this week's operations, which are estimated at $40,000 each.

Jessica Palmer, 8, who lives in Downingtown, Pa., underwent the procedure Tuesday. She is a medical pioneer already. When her mother was pregnant, doctors performed in-utero surgery to try to correct her spina bifida after it was diagnosed by an ultrasound test.

The Palmers say the pre-birth surgery did some good; Jessica walks with braces and is a bright second-grader who loves to draw and ride horses. "We were told she'd never walk," said her mother, Carol, a registered nurse.

"She's a tough little girl; she's been through so much already," said John Palmer, Jessica's father. The family considered going to China for the surgery. Though some risks are associated with it, "there's no guarantee with anything," Carol Palmer said.

There are no good estimates on the cost of incontinence in patients with spina bifida or spinal cord injury. The United States spends $16.3 billion a year on costs for urinary incontinence, according to a 2001 analysis in Obstetrics and Gynecology, a leading journal.

After several years of operating on animals, Xiao began performing the operation on humans with spinal cord injuries in 1995. He began doing the surgery on spina bifida patients in 2000, he said. In all, he's performed 340 surgeries, and says 80% have achieved satisfactory bladder control and no longer must use catheters. Some also have achieved bowel improvements, he said.

Children show regenerated nerves the fastest, he said. Those with prior bladder augmentations are not candidates for the operation.

Early on, two spina bifida patients developed muscular weakness and foot drop after the surgery, but changes in the technique have "dramatically decreased the incidence of this complication," Xiao said.

While he was doing a fellowship in Norfolk, Va., some of his research was underwritten by the Paralyzed Veterans of America and the National Institutes of Health, he said.

The surgery, called a hemi-laminectomy, is performed under general anesthesia and takes about two hours.

Doctors make about a four-inch incision near the lower part of the spine and open the dura, the protective sheath around the spinal cord, exposing the network of nerve roots that feed it. They find what they call a donor nerve in the leg, and measure its nerve conductivity with electrical tests.

The nerve then is split, with a portion still attached to the spinal cord, and routed to the bladder. There, another so-called recipient nerve from the spinal cord is spliced, again leaving a portion attached to the spinal cord, and the two ends are sewn together with a single stitch. It creates a new circuit that bypasses the brain, Peters said. "You are rerouting the nerve, using the nerve that moves the leg to feed nerves to the bladder."

Xiao compared the operation to fixing an electrical problem. Sometimes the lightbulb needs to be replaced; other times, the circuitry is the culprit, he said.

"What we are doing is putting the electricity back," he said.

BY PATRICIA ANSTETT

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