By Maggie Fox

W A S H I N G T O N, Aug. 21 Cells taken from a deadly tumor and retrained to become brain cells have been safely used to treat stroke patients, doctors said today.
　　Only about half of the patients improved, but the study shows the method is safe and strengthens the idea that brain cell transplants can be used to help stroke patients recover, the team at the University of Pittsburgh said.
　　No Home Runs Yet
　　“We did not try to hit a home run the first time at bat,"Dr. Douglas Kondziolka, a professor of neurological surgery at the University of Pittsburgh who helped lead the study, said in a telephone interview.
　　“This is very brand-new area of neuroscience. In a first study we are trying to get to first base. That means safety."br /> 　　Kondziolka’s team experimented on 12 stroke patients, all of whom had fairly serious brain damage. Strokes can cause problems with speech, hearing, movement and learning.
　　All got injections of the cells, which started out as cancer cells but were transformed into nerve cells using technology patented by researchers who formed a private company called Layton BioScience in Atherton, California.
　　Just under six months later, six of the 12 patients had improved scores on standard measures of stroke effects, Kondziolka’s team reported in the journal Neurology.
　　“They are things like a better ability to use the arm and leg, walking without a brace, strength in terms of being able to hold something better,"Kondziolka said.
　　Positron emission tomography (PET) scans showed the cells seemed to be functioning in about half the patients.
　　All of the nine men and three women, who ranged in age from 44 to 74 years, had an unusual type of stroke called a basal ganglia stroke. Kondziolka said these patients were chosen because such a stroke usually damages a small, contained area of cells.

Not Enough Brain Cells
　　“We don’t have enough brain cells to put all over the brain,"he said.Importantly, none of the patients developed cancer.
　　“The first patient is 27 months out. She’s the same,"Kondziolka said.
　　The cells all came from a 22-year-old cancer patient who died years ago from a tumor known as a teratocarcinoma.
　　Its cells have properties similar to stem cells "which are a kind of master cell in the body from which all other cells are produced. Scientists are studying the use of stem cells to also treat brain diseases, including Parkinson’s and Alzheimer’s.
　　“These cells are not stem cells but they are similar to stem cells in that they start out as extremely immature body cells,"Kondziolka said. “This was an embryonic tumor, not a brain tumor or a breast tumor."br /> 　　Layton BioSciences has kept these cells alive in a laboratory and has found a way to coax them into becoming what appear to be normal neurons.

Coaxing Cells
　　“The main thing is they sit for six weeks in retinoic acid,"Kondziolka said. This precursor to vitamin A helps encourage cells to differentiate.
　　“It takes cells that don’t know what they want to be when they grow up and makes them grow up,"Kondziolka said. Other agents stop the out-of-control replication that makes cancer cells so dangerous.
　　“At the end you are left with nerve cells,"he said.
　　Now the team is waiting for Food and Drug Administration (FDA) approval to start a phase II study in which more patients will be tested.
　　Dr. Justin Zivin, a neuroscientist at the University of California, San Diego, issued strong warnings about the study.
　　For one, he said patients will have to be watched for years to make sure the cells used do not revert to their malignant form and cause cancer.
　　“It is too soon to know whether it promises hope for disabled patients with stroke,"Zivin wrote in an editorial.
　　“Adverse effects may not have been seen because the injected quantities were too small to be effective and the larger cell numbers, sufficient to produce a major benefit, may have greater concomitant hazards,"he added.
　　
　　(From ABCNEWS.com)