Denny,
I found one article about this new procedure. I think this was what you
were referring to. It does sound hopeful, for other neurological
diseases, as well as PD. The article said they will be testing the
transplant in 24 more patients over the next two years. Let's hope the
results are good.
Linda Herman
For cell transplants, is one brain better than two?
American Medical News; Chicago; May 3, 1999; Mark Moran;
Volume: 42
Issue: 17
Start Page: 29
ISSN: 00011843
Subject Terms: Transplants & implants
Brain
Cells
Medical ethics
Abstract:
Neurosurgeons recently performed the first-ever autologous brain cell
transplant for a Parkinson's patient. This procedure could obviate
ethical
problems associated with fetal or porcine cell transplants.
AT A GLANCE
An experimental cell transplant for Parkinson's disease using autologous
brain cells could sidestep ethical and scientific problems associated
with
fetal and porcine cell transplants.
AUTOLOGOUS BLOOD DONATIONS are old hat, but a brain cell transplant using
the patient's own cells could turn a new page in cell grafting for
neurological conditions.
In March, neurosurgeons at Cedars-- Sinai Medical Center in Los Angeles
performed the first-ever autologous brain cell transplant for a patient
with Parkinson's disease. The cells, harvested from the patient's cortex
during prior implantation of a deep brain stimulator, were "regenerated"
in
culture dishes using growth factors and then differentiated into
dopamine-producing neurons. The regenerated cells were transplanted into
the patient's striatum, where it is hoped they will repair neurological
function and improve clinical symptoms.
Physicians at Cedars-Sinai said the procedure could obviate ethical and
scientific problems associated with fetal and porcine cell
transplantation.
"What we have is a protocol in which we don't have to harvest 12 or 15
fetuses, we don't have to give immunosuppressant therapy, and we don't
have
to worry about viral disease transmission," said Michel Levesque, MD,
director of the hospital's neurofunctional surgery center.
The procedure draws on new findings from animal studies showing that
certain brain cells behave like "progenitor" cells; when cultured in
specific media, they can be engineered to perform different neuronal
functions.
Cells that grow into dopamine-producing neurons then are selected for
transplantation, explained Toomas Neuman, PhD, director of neurobiology
at
Cedars-Sinai and Dr. Levesque's colleague in the experiment.
But the process of differentiating dopamine-producing cells in lab
cultures
is not yet perfect, and many of the estimated 5 million transplanted
cells
will die without producing dopamine.
"At this point, it's not a 100% pure culture," Dr. Levesque said. "We
predict only 10% of the transplanted cells will survive."
Despite this limitation, he said the procedure possesses a unique
conceptual elegance in the treatment of Parkinson's disease. "Instead of
delivering dopamine with a pill, we are using the patient's own cells to
secrete dopamine [in the region of the brain] where it is needed," he
said.
"We can call this a drug delivery system via cell therapy"
In the next two years, 24 patients with Parkinson's will receive the
transplant procedure. Patients will be evaluated for improvement in
clinical symptoms and receive periodic positron emission tomography scans
to determine if transplanted cells are producing dopamine.
In time, Drs. Levesque and Neuman hope to extend their autologous cell
transplant procedure to treat stroke and spinal chord injuries, which
would
be a considerably more complicated undertaking.
"Treating neurodegenerative diseases by introducing one type of
neurotransmitter cell into a particular part of the brain is
comparatively
straightforward," Dr. Levesque said. "But treating stroke and spinal cord
injuries with regenerated cells is infinitely more complex. We have to
identify, grow and reintroduce a complex mixture of cells to restore
damaged circuitry"
Doctors involved in treating stroke and neurological conditions said the
autologous procedure is conceptually intriguing, but that cell grafting
remains an unproven novelty.
"The concept makes good sense," said Joseph Broderick, MD, professor of
neurology at the University of Cincinnati College of Medicine, noting
that
use of autologous cells would eliminate potential for immunological
rejection.
But Dr. Broderick said results from cell transplant trials for
Parkinson's
had been mixed at best. He echoed Dr Levesque in emphasizing the
significantly greater complexity involved in reversing neurological
damage
from stroke or spinal chord injury
An experimental cell transplant for 12 stroke patients at the University
of
Pittsburgh Stroke Institute so far has proven to be safe with no
complications from surgery, said institute Director Lawrence Wechsler,
MD.
But while some patients have reported subjective improvement in symptoms,
there has been no dramatic change on objective measures of functioning.
The
12 patients in the protocol will continue to be evaluated using
functional
magnetic resonance imaging.
