Tuesday, February 15, 2005

Compound in Urine May Fight Spinal Cord Injury

Uric acid, a metabolic breakdown product found in urine and blood, may help reduce damage from spinal cord injury, researchers say.

In research with mice, scientists at Thomas Jefferson University, Philadelphia, found that uric acid helped lessen some of the secondary cellular damage that occurs following spinal cord injury. This secondary damage is caused when the body's inflammatory response releases potentially harmful chemicals that exacerbate the injury.

Mice given uric acid just before and after they suffered a spinal cord injury recovered motor function quicker, and to a greater degree, than mice receiving a simple saline solution. In cell culture tests, the researchers discovered that uric acid protected spinal cord neurons from damage caused by a compound called peroxynitrite, which is linked to cell damage caused by inflammation.

The findings, reported in this week's issue of Proceedings of the National Academy of Sciences, might someday help in the development of new treatments for spinal cord injuries, the researchers say.

By Robert Preidt
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Saturday, February 12, 2005

Pig cells may help restore spinal cords

A study published by scientists at the Yale Center for Neuroscience and Regeneration Research suggests the inner lining of a pig's nose could be used as a treatment for spinal cord injury or disease.

The results of an experiment conducted several months ago showed that damaged monkey spinal cords repaired themselves when the pig cells were transplanted to the affected area. Led by Center Associate Director Jeffery Kocsis, a team of scientists is currently working to ascertain whether these results were due to the successful transplantation of pig olfactory cells or if the spinal cords repaired themselves independent of the transplanted cells.

Lakshmi Bangalore, the scientific liaison officer at the center, said pig cells were used because they can produce myelin -- the fatty tissue that insulates nerve fibers in the central nervous system and helps transmit signals along nerves with speed and efficiency. A spinal cord injury usually does not kill neurons, but damages the myelin surrounding them so that nerves can no longer function properly, she said. In the group's study, transplanted cells from genetically engineered pigs caused a regeneration of myelin around the damaged nerve cells, which restored their ability to transmit information throughout the nervous system.

Bangalore said the research has significant implications for the treatment of multiple sclerosis.

"MS is caused by a lack of myelin, and, after transplanting these cells into damaged areas, we did see regeneration and remylenation," she said. "Right now we're just trying to learn as much as possible."

Associate research scientist Karen Lankford said the center has recently begun to transplant nerve cells from a monkey's leg into its own spinal cord. This process differs from the original pig cell transplantation, she said, because now, instead of transferring cells from one species to another, the cells taken from one animal are put back into the same individual.

Lankford said this process has an even greater significance than the cross-species transplantation, as it relates to the eventual treatment of humans.

"Ideally, you'd want to use a person's own cells," she said. "Even though the pig cells are genetically engineered, they're still a foreign cell that could possibly be rejected."

Kocsis said that so far, it appears that the monkey cells require the transplanted pig cells in order to regenerate myelin.

In contrast, damaged cells within a rat's spinal cord will spontaneously undergo a process of self-repair and will remyelinate themselves without the transplantation of any other cells.

"This process of self-repair doesn't occur in humans, and we haven't seen any self-repair in the primates that we have been studying," Kocsis said. "The potential is there, but they don't normally repair on their own."

Kocsis said further research at the center is directed toward determining whether or not the spines of other animals can be stimulated to regenerate by progenitor cells -- cells that are slightly more differentiated and specialized than stem cells. He said the research team is also testing to learn if young progenitor cells can be introduced into the central nervous system to facilitate remyelination.

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Thursday, February 03, 2005

How estrogen may lead to a cure to spinal cord injuries.

Napans with spinal injuries hear how estrogen may lead to a cure

A group of Napans with serious spinal injuries recently heard about possible cures for what ails them from a leading scientist in the field.

Using the female hormones estrogen, a UC Davis professor is working toward a cure for spinal cord injuries in both sexes.

UC Davis' Dr. Candace Floyd, a professor in the school's department of Neurological Surgery, discussed her work with 30 members of the Napa Spinal Chord Injury Network (NSCIN) last week. Using the female hormones estrogen, Floyd is working toward a cure for spinal cord injuries in both sexes.

"I started looking at the data," she said. "Eighty-two percent of spinal cord injury patients are male and most injuries occur between the ages of 16 and 30. Even women involved in the same accidents were coming out better," she noted.

"Could there be a reason women are less affected by traumatic events? Why is it 80 percent men?" she said.

After describing some highly technical effects injuries have on spinal nerves, she speculated, "Maybe estrogen has an ability to heal nerves. My idea is that a female in a motor vehicle accident may have something in her body that makes her walk away from it."

Estrogen's benefits

Floyd began looking at how toxins spread through the spinal cord in the weeks after an injury had occurred.

"(It's) a secondary injury that can have more impact than the original injury," she told the audience, more than half of whom were in wheelchairs. Estrogen has been known to save those cells after injury, she said.

Floyd added that researchers are looking for a drug that will protect spinal cord tissue. "We are trying to look at one type of pharmaceutical that will go after the injury from several different angles," she said. "Estrogen may be that drug. Estrogen is already approved, so you wouldn't be starting from scratch."

Floyd said most estrogen research ground to a halt a few years ago when testing of the effects of estrogen on chronic heart disease brought up safety concerns. "They used Premarin in their research. Out of ten estrogens in Premarin, three of them are natural in humans. Several of them are toxic," she said.

To see if she was right, Floyd and her colleagues crushed the spinal cords of several rats. Some were given estrogen before the injury, while others were given the hormones afterward. Some rats received no estrogen.

The animals that were given estrogen before the injury had substantially more living spinal cord cells, as did the ones that received estrogen right after the injury, though their injuries were more severe.

She cautioned that these experiments are very preliminary and raise as many questions as answers.

"We want to know how long you can wait after the injury," Floyd told the audience. "We have strong evidence that it helps before injury, but what about after the injury? You can put a (estrogen) patch on somebody in the ambulance. We haven't done that study yet."

There are other problems with estrogen as a treatment, according to Floyd.

"Fourteen days is the limit a man can take estrogen without feminizing effects," she said. "We need to test how long and how much you need."

Floyd said the research community is slow to accept any kind of estrogen research.

"In the beginning, surgeons are really reluctant because of ... how negative the press has been for estrogen research," she said. "But when they see the data, they get the idea of what we're trying to do. It kind of sways them."

There is one thing that researchers and pharmaceutical companies like about estrogen.

"Estrogen has already passed all the safety trials," Floyd said. "That's money in the bank. This is commercially available, if you have a prescription."
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Australian breakthrough in spinal cord research

An Australian breakthrough in spinal cord injury research could help patients with bowel, bladder and sexual function problems.

The research shows those functions are controlled by nerve cells in the spine rather than in the brain.

The principal Research Fellow of the National Health and Medical Research Council, Professor Ida Llewellyn-Smith, says the finding has huge potential.

"If there is this whole network of nerve cells in the spinal cord that are actually the major control centre, then it might be actually much easier to get these functions back than to get blood pressure control back to normal where most of the neurons that actually control that function live in the brain," Professor Llewellyn-Smith said.
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New hope for spinal cord injury patients

Tiny nerves taken from the rib cage, fortified with a powerful growth inducer and transplanted in the spinal cord significantly reversed paralysis in rats with spinal cord injuries.

That's the finding of a study in the October issue of the Journal of Neurotrauma.

The study shows that nerve cells can be inserted and stimulated to grow in damaged areas of the spinal cord, and the discovery may lead to improved treatments for people with spinal cord injuries.

Using this method, researchers from the University of California-Irvine (UCI) and the Long Beach Veterans Administration Medical Center were able to partially restore hind leg movement in rats with severed spinal cords.

"By using tiny nerves from the rib cage as cables connecting the severed spinal cord, we were able to get some improvement in leg function," says Dr. Vernon Lin, a professor of physical medicine at UCI and director of the Spinal Cord Injury Group at the Long Beach V.A.

"Regeneration is considered very difficult because the damaged area apparently inhibits growth of new nerve-cell connections. This study gets us closer to arriving at the right combination of growth factors, nerve cells and physical stimulation to overcome these inhibitions and successfully treat spinal cord injury," Lin says.

The growth inducer used in this study, a molecule called aFGF, is found in most nerve cells.

The rats with severed spinal cords that received both a FGF and the nerve grafts were able to move their hind legs and could support some of their weight on those legs after treatment. Rats that received either a FGF or nerve cell grafts alone had nearly no improvement, the study says.
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Tuesday, February 01, 2005

US researchers create motor neurons with human stem cells

Researchers have successfully coaxed human embryonic stem cells into becoming spinal motor neurons in an experiment that might help scientists repair damaged nervous systems.

Spinal motor neurons relay messages sent from the brain to the rest of the body, making them critical components of the nervous system.

Researchers at the University of Wisconsin-Madison hope this technology will one day lead to treatments and cures for spinal-cord injuries and diseases like Lou Gehrig's disease.

Transforming embryonic stem cells into motor neurons had eluded researchers for decades, until now.

Lead researcher Su-Chun Zhang said their trial-and-error study helped them learn how motor neuron cells, which are key to the nervous system, develop in the first place.

He said the next step will be to transplant the newly generated neurons into a living animal.

Zhang also cautioned that it will be many years before they can be tested in humans.
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