More MS news articles for August
2000
Study: Cell Transplants Safe for Stroke
Patients
Monday August 21 7:24 PM ET
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Cells taken from a deadly tumor and retrained
to become brain cells have been safely used to treat stroke patients, doctors
said on Monday.
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.
"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."
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.
"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.
Cells Come From Cancer Patient
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."
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.
"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.