I know I sent the press release re Spheramine, but don't know if anyone
else posted this...jmr
Cell Implants For Parkinson's Are Ready For Human Tests
NEW YORK, Nov 01, 1999 (NYT Syndicate) — A new brain implant therapy for
Parkinson's disease that doesn't rely on human or animal fetal tissue
has shown such promising early results in monkeys that researchers plan
to try it soon in humans.
In seven monkeys with a drug-induced form of Parkinson's, the cell
implants resulted in an improvement in each animal that varied from 44
percent to 90 percent within three months.
Richard C. Allen of Titan Pharmaceuticals Inc., which developed the
therapy, said last week he believes it can bring about "long-term,
significant restoration of function" using implants of "readily
available human cells" that could be stored frozen and used as an
off-the-shelf product.
The cells are dopamine-producing cells that form a pigmented layer
in the retina of the human eye. Why retina cells produce dopamine, the
substance lacking in PARKINSON'S, is not known. The cells can be
obtained from donor eyes at organ banks and then grown and multiplied in
the lab. For implanting, the cells are deposited on the surface of tiny
gelatin spheres — they are barely visible to the naked eye — and
hundreds of thousands of spheres are injected into the patient's brain.
The cell product is called Spheramine.
One donor eye could provide enough cells to perform thousands of
implants, said Allen. And, unlike implants of human or animal fetal
cells, the Spheramine cells are not attacked by immune cells in the
brain. Exactly why that is hasn't been determined for certain, said
Allen.
The Spheramine results were presented at a recent meeting here of
companies developing tissue engineering and "regenerative medicine"
products. The meeting was sponsored by TechVest LLC, an investment
research firm.
The Spheramine clinical trials will be carried out at Emory
University School of Medicine in Atlanta. Dr. Ray Watts, an Emory
neurologist, said Friday that the animal studies, in which he is
involved, have shown a "very prominent" improvement. He said it is too
soon to predict the eventual role of Spheramine in Parkinson's disease.
More than 500,000 people in America have Parkinson's, including US
Attorney General Janet Reno and actor Michael J. Fox.
The disease results from the death of brain cells that produce
dopamine, a key chemical messenger needed for smooth and coordinated
movement. Symptoms usually begin in middle age or beyond: they include
tremors of the hands and, as the disease progresses, slowed movement,
balance and gait difficulties, rigid extremities, and profound
disability.
Medication that provides dopamine to the brain can keep symptoms
under control for a few years, but eventually the drugs lose much of
their effect. In the 1990s, surgeons have experimented with implanting
dopamine-producing nerve cells into the brain, in hopes the nerves would
take root and pump out a constant supply of dopamine.
This strategy requires fetal cells that can adapt to their new
environment. Implants of human fetal cells are likely to have a limited
role because they present ethical issues, and because aborted fetuses
would not provide a large enough supply for the expected demand.
Recently, implants have been carried out with fetal pig cells. A
Charlestown company, Diacrin, Inc., has been developing the pig system
and its president and CEO, Thomas H. Fraser, reported on its progress at
the tissue engineering conference.
Fraser said that in a study of 11 implant patients who got a low
dose of pig cells there was an average of 20 percent improvement in
symptoms. Three patients have had "spectacular recoveries," he said,
while three remained at their pre-treatment level of disability, and the
other five were "somewhere in between."
It takes about 16 fetal pigs to provide enough nerve cells for a
transplant, Fraser said. The cells have to be used almost immediately.
By contrast, the Spheramine system allows cells to be frozen and kept
indefinitely, and does not require raising large animals, as the Diacrin
effort does.
Watts, at Emory, is involved in research for Diacrin as well as the
Spheramine experiments. At this point, he said, "I don't think you can
say yet whether one is more effective or more promising than the other."
©1996-1998 Inteli-Health, Inc.
~~~~
Judith Richards, London, Ontario, Canada
[log in to unmask]
^^^^
\ /
\ | / Today’s Research
\\ | // ...Tomorrow’s Cure
\ | /
\|/
`````
