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Jeremy
10-01-2002, 04:24 PM
Neural stem cells improve motor function in brain injuries

Oct 1st,2002
Transplants in animal models could translate into therapy for humans
(Philadelphia, PA) - Neural stem cells, transplanted into injured brains, survive, proliferate, and improve brain function in laboratory models according to research based at the University of Pennsylvania School of Medicine. The findings, published in the October edition of the journal Neurosurgery, suggest that stem cells could provide the first clinical therapy to treat traumatic brain injuries. Traumatic brain injuries occur in two million Americans each year and are the leading cause of long-term neurological disability in children and young adults.
"Transplantation of neural stem cells in mice three days after brain injury promotes the improvement of specific components of motor function," said Tracy K. McIntosh, PhD, professor in the Department of Neurosurgery, Director of Penn's Head Injury Center, and senior author of the study. "More importantly, these stem cells respond to signals and create replacement cells: both neurons, which transmit nerve signals, and glial cells, which serve many essential supportive roles in the nervous system."

If stem cells are blank slates, able to become any type of body cells, then neural stem cells (NSCs) are slates with the basics of neurology already written on them, waiting for signals in the nervous system to fill in the blanks. The NSCs used by McIntosh and his colleagues were cloned from mouse progenitor cells and grown in culture. The advantage of NSCs exists in their ability to easily incorporate themselves into their new environment in ways other types of transplants could not.

"If you put these cells into normal newborn mice, they would behave exactly like normal cells - they create different neural cell types and they don't reproduce tumorigenically," said McIntosh. "In humans, the use of similar neural stem cells would avoid the ethical dilemmas posed by fetal stem cells and the limitations seen in cultures of cloned neurons."

In humans, traumatic brain injury is associated with disabilities affecting mobility, motor function and coordination. Following NSC transplantation in mice, the researchers used simple tests to determine motor skills. They found that mice with transplanted NSCs recovered much of their physical ability. The transplanted NSCs, however, seemed to have little effect in aiding recovery of lost cognitive abilities.

"The ultimate goal, of course, is to translate what we have learned into a therapy for humans," said McIntosh. Neural transplantation has been suggested to be potentially useful as a therapeutic intervention in several central nervous system diseases including Parkinson's disease, Huntington's disease, ischemic brain injury, and spinal cord injury. While McIntosh is impressed with the results of NSC transplants in mice, similar trials for humans are not expected in the near future.


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The lead author on this study is Peter Reiss, MD, a visiting fellow from the University of Cologne working in Dr. McIntosh's laboratory. Much of the work was performed in collaboration with the laboratory of Evan Y. Snyder, MD, Harvard Medical School. Other contributing researchers from the Department of Neurosurgery include, Chen Zhang, MD, PhD, Kathryn E. Saatman, PhD, Helmut L. Laurer, MD, Luca G. Longhi, MD, Ramesh Raghupathi, PhD, Philipp Lenzlinger, MD, Jonathan Lifshitz, PhD, John Boockvar, MD, Grant Sinson, MD, and M. Sean Grady, MD. Contributing researchers from outside of Penn include Edmund Neugebauer, MD, of the University of Cologne, Germany and Yang

"If the wind could blow my troubles away. I'd stand in front of a hurricane."

James Kelly
10-01-2002, 09:23 PM
Hello Jeremy:

Can you tell me where you found this article? Thanks!

James Kelly

Max
10-21-2002, 01:38 PM
Embryonic stem cells help brain-injured mice, study finds
BY STACEY BURLING
Knight Ridder Newspapers

PHILADELPHIA - (KRT) - An injection of embryonic stem cells helped brain-injured mice perform markedly better on physical tasks but did not improve their cognitive ability, researchers at the University of Pennsylvania School of Medicine have learned.

The study may ultimately have implications for the millions of human beings who have had traumatic brain injuries, said Tracy McIntosh, senior author of the study published in this month's issue of the journal Neurosurgery. No known treatment can restore function in damaged areas of the brain, said McIntosh, who directs Penn's Head Injury Center.

Any treatment for people based on this research is years away, he said, but these results are promising because injured mouse and human brains behave similarly.

The Penn researchers compared results in 65 mice. Thirteen were given anesthesia and a surgical incision - mock surgery - but were not injured or treated. In the remaining 52 mice, a part of the cortex that is important for motor skills was damaged. Half of those mice were given an injection of kidney cells, which would not be expected to function in the brain. The other half were injected with about 300,000 embryonic stem cells.

Although the hippocampus, a key center in the brain for memory and learning, was not directly injured, cells there often die when other parts are damaged, McIntosh said. The mice in the study showed cognitive as well as physical impairment.

Embryonic stem cells can differentiate into working cells in any part of the body. Once the cells have been harvested, a continuing line can be grown easily in a culture, so it's not necessary to repeatedly gather them from embryos, McIntosh said.

In this study, the researchers found that an estimated 30 percent of the injected embryonic stem cells were still alive at three months. Some were functioning as neurons, which transmit nerve signals, and others had turned into glial cells, which supply nerve cells with food and energy.

They had migrated to damaged areas of the brain. "They seem to want to go where they're needed," McIntosh said.

The animals were then given two tests that measured balance and sure-footedness. One, for example, required the mice to walk across a rotating pole. A normal mouse does not find this difficult. The injured mice who had been treated with the stem cells made about half as many "foot faults" as those who had not received the treatment.

However, the treated mice were no better at negotiating a maze than those in the control group.

McIntosh said the cells were injected close to where the physical damage to the brain occurred and tended not to migrate to the hippocampus. A future study will measure what happens when the cells are delivered closer to that part of the brain.

In this study, the stem cells were injected three days after the injury occurred. Because so many people are suffering from brain injuries that occurred years ago, McIntosh also will examine what happens when the stem cells are transplanted longer after the damage.

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© 2002, The Philadelphia Inquirer.

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Distributed by Knight Ridder/Tribune Information Services.

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