Found this at msnbc.com. Sounds promising.
Sept. 13 - Using a disabled tumor virus as ammunition, scientists said
Monday that they hope to launch an attack on the mind-robbing disorder
Alzheimer's disease within the year. The novel approach involves using
genetic engineering to introduce into the brain growth factors that prevent
cell death while concomitantly coaxing other cells back to life.
USING THIS method, "we can intervene in what we thought were untreatable
neurological disorders - not just Alzheimer's but Parkinson's and other
diseases of the brain and nervous system as well," said lead scientist Mark
H. Tuszynski of the University of California, San Diego.
So far, the designer engineering technique has stimulated the growth
of new brain cells in both rats and rhesus monkeys. With no signs of adverse
effects, Tuszynski said he applied in June to the Food and Drug
Administration to test the gene therapy technique in humans with Alzheimer's
disease.
The findings, which appear in this week's Proceedings of the National
Academy of Sciences, were first reported on MSNBC.com after Tuszynski
presented them last winter at the annual meeting of the American Association
for the Advancement of Science.
About 4 million Americans have Alzheimer's disease, which each year
claims some 100,000 lives in the United States. Worldwide, experts estimate
that 5 percent of those over 65, and up to 40 percent of those over 80, have
the disease.
Alzheimer's usually begins gradually, causing a person to forget
recent events or familiar tasks. How rapidly it advances varies from person
to person, but the degenerative disease eventually causes confusion,
personality and behavior changes and impaired judgment. Communication
becomes difficult as the affected person struggles to find words, finish
thoughts or follow directions. Eventually, most people with Alzheimer's
become unable to care for themselves.
The reason for their symptoms: the formation of abnormal structures
in the brain called plaques and tangles. As they accumulate, nerve-cell
connections are reduced and cells die off.
The hope is that the production of nerve growth factors inside the
brain will rescue damaged brain cells and enhance the production of other
depleted cells, Tuszynski reported.
The first step, he said, is to take a tiny skin biopsy, isolate the
immature developmental cells known as fibroblasts and let them multiply in a
nourished environment in the test tube. Meanwhile, a leukemia tumor virus is
made inactive by deleting the gene that tells it to divide. The genes that
code for nerve growth factors are slipped into its place
"The virus is now safe as we have taken out the bad genes and replaced
them with good ones," Tuszynski said.
The fibroblasts are then genetically modified with the viral mixture,
and the hybrid stored in a little bottle. Using a long needle, the virus
mixture is drawn up into a syringe and surgically implanted in the brain,
Tuszynski said. He hopes that patients will need injection once a year at
most.
"This is a reliable, efficient and practical way to stimulate nerve
cell growth," the California scientist said.
Unlike drugs that are being tested for Alzheimer's, "this would
prevent - not patch," he said.
While previous human gene therapy experiments have failed after the
genes stopped producing the desired proteins as soon as two weeks after the
procedure, nerve growth factors are still being produced - and cell death
prevented - in rats 18 months after the experiments began, he added. The
monkeys have so far been followed for eight months with similar results,
Tuszynski said.
But, he warned, there are still some unknowns. Since animals do not
get Alzheimer's' disease, there is no way of proving the technique will
combat the disease until human testing begins.
"What we have shown in animals is that the technique stimulates new
nerve cell growth," he said. "And that the technique nearly completely
reversed" the effects of aging on certain key brain cells.
Also, while there is no evidence that injecting the hybrid cells
directly into the brain will harm humans, it is a theoretical concern, he
said.
SAFETY, THEN EFFICACY
Once safety is established in human studies, a larger clinical trial
will begin to determine if disease progression can be slowed and even
halted.
And eventually, he said he would like to develop a form of gene
therapy in which the patient's own cells would be directly injected with
designer nerve growth factors. That would eliminate the need for yearly
injections, Tuszynski explained.
Dr. Evan Snyder of Harvard Medical School applauded the new approach.
"Tuszynski has shown that you can genetically engineer cells to crank out
nerve growth factor," he said. "There's good evidence that this approach
will rescue the dying brain cells [of Alzheimer's]."
