From the Melbourne Age newspaper, May 2 1998
A Melbourne scientist has developed a world first treatment that could result in the reversal of debilitating nerve disorders such as motor neurone and Alzheimer's disease. The research, expected to be tested on humans within 12 months, marks the first time the breakdown of nerve cells has been prevented.
Dr Graham Barrett, a senior lecturer in the department of physiology at the University of Melbourne, has been working on the treatment for six years. He says he is confident his results - showing that mice which have had nerves in their spine and elsewhere severed, can be returned to full mobility - will translate to humans.
"When we first started to get some great results (with the reversal of nerve damage), I believed we had a 20 per cent chance of getting to trial the technique in humans," he told The Age. "Now I believe we have a greater than 50 per cent chance, which is very high for this sort of research."
Dr Barrett's study focusses on a protein called p75, which sits on the surface of many nerve cells. These cells remain alive as long as a hormone called NGF binds to the p75 protein. When the levels of NGF die off, as occurs in ageing, the exposed p75 molecule triggers the nerve cell to die. Dr Barrett calls this the "death factor". After an accident, or in neurodegenerative diseases such as Alzheimer's, the supply of NGF is cut off. Attempts by researchers to replace these NGF stores immediately after an accident to prevent nerve cell death have failed.
Dr Barrett has focused on the p75 molecule instead. He and his team have developed a drug that stops the "suicide" of the protein. One of the main hurdles will be in delivery of the drug. The brain and nervous system have their own circulation of cerebro-spinal fluid, which is almost completely separate from the blood system. Because of this, it has always been difficult to get drugs into the brain. Treatments injected into a vein won't travel to the brain, and it is dangerous and difficult to inject drugs into the spinal fluid.
Working with Dr Surindar Cheema from the anatomy department at Monash University, Dr Barrett has developed a delivery system that can get the drug to the brain, or the site of injury in the spine. "We are optimistic that we can modify the drug so that it will get across the blood-brain barrier - and we have evidence of this already," he says. The modification - which specifically targets p75 - has been patented.
"The results have been stunning. In experimental rats with (experimentally induced) motor neurone disease, we have achieved 90 per cent recovery," he says. Motor neurone disease is a particularly debilitating illness, killing one Australian every day.
When Dr Barrett first stumbled across the idea that preventing the action of p75 could stop cell death, he was so disbelieving that he put the experiments on the back-burner, sure that they were a fluke.
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