:
TO  : MTS@gnv.ifas.ufl.edu ........ Tom Sanford
    : murray@seattleu.edu ......... MaryAnne Murray
    : stever@tessi.com ............ Steve Rintala
    : SMIRNES@IMIHSRA.BITNET ...... S. Palazzi, MD
    : PHIP@TEMPLEVM.BITNET ........ Tina Phipps, Ph.D.
    : RRICCIUT@WCU.BITNET ......... Rae Ricciuti
FROM: broedel@geomag.gly.fsu.edu .. Bob Broedel
    :
RE  : neurotrophic factors (BDNF)
    :
===
Body Substances May Aid in Treatment of Nervous System Diseases
By Boyce Rensberger
Washington Post Staff Writer
===
 
   Scientists have discovered that certain natural compounds in the 
body can keep damaged nerve cells alive under circumstances that 
normally would kill them. They say it may be possible to develop 
the substances into an entirely new class of drugs to treat 
afflictions that result from nerve cell death such as Parkinson's 
disease, Alzheimer's disease, ALS (or Lou Gehrig's disease) and
injuries that sever nerves.
   While the scientists are willing to suggest such prospects, 
they emphasize that the compounds' remarkable powers have only 
just been discovered in relatively simple experiments and that it 
will be years before they can become useful drugs, if ever.
   The substances, about half a dozen of which are known, are 
called neurotrophic factors. One is already being tested in 
patients with ALS, or amyotrophic lateral sclerosis, the 
progressive, nerve-destroying disease whose best known victim 
today is Stephen Hawking, the almost totally paralyzed 
astrophysicist.
   "This is potentially a very, very powerful tool to limit or 
even reverse the degenerative process underlying many different 
diseases," said Irwin J. Kopin, associate director of the 
National Institute of Neurological Diseases and Stroke, who has 
been watching the field develop over recent years. "But it's
going to be a long time in the future."
   The newest, and some say the strongest, claims for these 
compounds are being published in today's issue of the journal 
Nature. Three research teams in the United States and Germany 
report that a chemical called BDNF, for brain-derived neurotrophic 
factor, can keep motor neurons alive even when their long axons 
are cut in two.
   Motor neurons are nerve cells that carry the signal that 
tells muscles to move. The main part of each such cell, the "cell 
body" that contains the nucleus and other "vital organs," lies 
within the spinal cord and sends out one long filament, called 
the axon, that carries the signal. Axons can be several feet
long. A nerve is a bundle of many axons.
   Ordinarily when a motor nerve's axon is cut, the result is 
not just a cell with a stub of an axon. Instead, for reasons 
that have long been puzzling, the whole cell dies.
   "We don't really know what makes a cell give up the ghost," 
said William D. Snider, a neurologist who did some of the new 
research at the Washington University medical school in St. 
Louis. "But what we've got now is an agent that stops that from 
happening."
   Snider and his colleagues tested BDNF on newborn rats by 
cutting the animals' sciatic nerves, which run from their spinal 
cord down their legs, and then placing the substance directly 
in the wound. In untreated animals, nearly half of the neurons 
died within six days. The animals that got BDNF sustained very
few neuronal deaths.
   Michael Sendtner and colleagues at the Max Planck Institute 
for Psychiatry in Martinsried, Germany, report in the same issue 
of Nature that they found much the same results when severing 
nerves that go to facial muscles in newborn rats.
   BDNF, like other neurotrophic factors, is thought to be 
released by certain tissues in the body to help developing 
nerve cells guide their axons as they grow out from the spinal 
cord and snake toward their target muscles. Snider and his 
colleagues found that motor nerve axons in newborn rats 
transport BDNF toward the cell body. The idea, so far unproven, 
is that axons headed in the wrong direction pick up little or 
no BDNF and therefore die while those following the right path 
live.
   A third report in the journal confirms BDNF's role in 
development. Ronald W. Oppenheim of Wake Forest University in 
Winston-Salem, N.C., and his colleagues showed that when chick 
embryos are dosed with BDNF, motor neurons that normally
die of "programmed cell death" at a key stage, keep on living.
   Snider said that once animals mature, there appears to be 
no more BDNF flowing in the system. "This is a strong caveat 
in applying this work to patients," Snider said. "No one has 
yet shown this kind of effect in adult animals. Still, it's 
exciting because anthing that promotes survival of the neuron 
could have clinical potential."
   BDNF, which was discovered by Yves A. Barde, a member of 
the German group, has been patented, and the rights are now 
owned by Amgen Inc., a biotechnology firm in Thousand Oaks, 
Calif. An Amgen scientist, Qiao Yan, was a co-author of two 
of the papers.
 
== end of als 3 ==