NEW YORK, Dec 01 (Reuters Health) -- Purdue University researchers have
restored
nerve
impulses in extracted damaged or severed sections of guinea pig spinal cords.
Dr. Richard B.
Borgens presented his team's findings recently at the 18th annual meeting of
the
Society for
Physical Regulation in Biology and Medicine in Long Beach, California.
The researchers sliced spinal cord segments from adult guinea pigs into two
segments, then
applied a polymer called polyethylene glycol (PEG) directly on the end lesions
for 2 minutes. The
polymer fused the cut portions, which allowed electrical impulses to be
restored
between the
segments.
The researchers used the analogy of a broken garden hose to explain how the
process works. "If
we cut the hose and just hold the two ends tightly together, their not going
to
reconnect or
function as a hose. But if we add this special molecule, PEG, the 'rubber'
melts
a tiny bit on each
side and literally fuses the hose back together," explained Borgens, director
of
paralysis research
at Purdue in West Lafayette, Indiana, in a release to the press.
Nerve impulses were restored between the cut segments within 5 to 10 minutes,
the researcher
said.
Borgens told Reuters Health that "preliminary findings in live animals show
similar results. This
process is a new way of thinking about the repair to spinal cord or,
potentially, other nerve
injuries."
In a similar study presented recently at the 28th Annual Meeting of the
Society
for
Neuroscience, held in Los Angeles, researchers reported reconstructing spinal
sheaths and
restoring nerve signals in rat spinal cords.
In collaboration with Alexion Pharmaceuticals, Yale University School of
Medicine researchers
either partially severed spinal cords or chemically destroyed the myelin
sheath
that surrounds
portions of nerve cells. Myelin functions to enhance nerve conduction.
The rats were injected with genetically engineered pig cells containing human
Schwann cells or
ensheathing cells -- cells that support the formation of the myelin sheaths in
humans. The rats also
received immunosuppressive drugs, according to Alexion Pharmaceuticals
President
Dr.
Leonard Bell.
Bell reported that the chemically destroyed spinal sheaths showed signs of
reconstitution
following injection with either of the two types of transgenic pig cells.
Yale University's Dr. Jeffery D. Kocsis said in an Alexion press release that
"Alexion's transgenic
pig cells were associated with the highest levels of spinal cord repair and
regeneration that we
have yet seen using this transplantation approach."