| Cowboy 2005-11-30, 10:58 am |
| http://www.guardian.co.uk/medicine/...1653838,00.html
The nose cells that may help the paralysed walk again
Surgeons in London to try revolutionary stem cell technique on crash
victims
Sarah Boseley, health editor
Wednesday November 30, 2005
The Guardian
Surgeons will attempt early next year to mend the severed nerves of
young people who have suffered motorbike accidents in the first trial
of a simple but potentially revolutionary technology that could one day
allow the paralysed to walk again.
At least ten operations will be carried out to test in humans a
technique pioneered in animals by the neuroscientist Geoffrey Raisman,
who heads the spinal repair unit of university College, London. He
discovered 20 years ago that cells from the lining of the nose
constantly regenerate themselves. Professor Raisman's team believes
that if those cells were implanted at the site of the damage they would
build a bridge across the break, allowing the nerve fibres to knit back
together.
Christopher Reeve, the actor who played Superman and became paralysed
after falling from a horse, had hoped that Prof Raisman's work would
bring a breakthrough, and they had planned to meet shortly before Reeve
died.
The first operations will not enable someone as badly hurt as Reeve was
to walk again, but they could heal the common motorbike injury
sustained when the nerves in the arm are pulled out of the spinal cord.
Until now, such injuries have been inoperable.
"I don't know that it will work, but I think it will work," Prof
Raisman said yesterday. "If you forced me to bet, I would bet on it
working.
"I have been patient. I didn't jump in the dark. I have grown through
the research all these years. It was in 1985 I discovered the cells. It
has taken 20 years before I felt we had the technology to apply this to
people. After spending this amount of time developing it, I'm not in a
hurry. This is not the final stage, but it is the crucial stage of the
research."
Studies in animals have established that the cell implants can restore
nerve functions. Rats with severed nerves have regained functions of a
forepaw. But the first human study, which tests the safety of the
procedure, will be limited to patients with one very specific and
similar injury to ensure the results are clear.
But there is no doubting the significance the results could hold. "If
this works well, it opens the door to an enormous area," Prof Raisman
said. "This is a door which has never been opened: to repair injuries
to the brain and spinal cord caused by the disconnection of nerve
fibres. The best possible outcome will be that these patients will get
a return of sensation to the arm and a reduction of the pain associated
with that injury."
If successful, with refinement and research the procedure could be
tried on people in a wheelchair. It also has the potential to heal
other nerve injuries, such as those caused by stroke, blindness and
deafness. "This is proof of principle," Prof Raisman said. "If it is
proved, I think there will be so much publicity we will be lucky to
stay in the field. It will be like a tidal wave. But the only race I'm
in is the human race. This has got an enormous future but I don't have
the illusion I'm going to see it all the way through."
At the beginning of the year, when he and his team moved from the
national institute for medical research in the US to set up the UCL
spinal repair unit, he predicted the first attempts in humans would not
take place for two to three years.
"I was wrong. Isn't that nice?" he said. The unit moved to a base at
the National Hospital for Neurology and Neurosurgery in Queen's Square,
and the team came together, he said. Funding is still an issue,
however. The unit is =A31m short of its target. Although things were
going well, it had not always been easy, he said. "We have been
mavericks in this research all my research life. I have never been on
the side of the majority view.
"This is not the most popular way of attempting to heal spinal
injuries. That would be to produce patented chemicals, which drug
companies can make and sell. What we're proposing could be carried out
by any very modestly equipped hospital with neurosurgery. There are no
patents. It makes it a very unpopular form of research.
"We're producing a procedure where the patient is their own cure. You
can't patent a patient's own cells, thank God."
FAQ
Why the nose is unique
What sort of cells are going to be used to try to repair nerve damage?
Cells from the nose. The all-important discovery made in 1985 showed
that in one section of the nervous system, a part of the nasal cavity
concerned with smell, nerve fibres are in constant growth - even in
adulthood. Though people with a bad cold may lose their sense of smell,
it does come back.
The nasal cells have the added advantage of belonging to the patient,
so there is no risk of their being rejected.
What do the cells do when transplanted into the spinal cord of rats?
They mend the break in the pathway that nerve fibres need to take if
they are to rejoin. When a nerve is severed, it tries to regrow, but
the pathway has been disrupted. The transplanted cells have the
capacity to integrate with the pathway cells, laying a "bridge" across
the gap and enabling the nerve fibres to reconnect.
What improvements were shown in the animals?
The transplants enabled animals that had been paralysed to reach with a
paw and to climb. They also restored the ability to breathe.
|