Friday, January 8, 1999 Published at 00:25 GMT
CJD discovery in mice
Mice were cured of scrapie
A chemical that experts believe may be able to treat the brain disease CJD has produced spectacularly successful results in mice.
A team from the Institute for Animal Health in Edinburgh inoculated mice that had been infected with scrapie - a disease of the brain similar to CJD - with the chemical pentosan polysulphate (PS).
Animals injected with one milligram of PS appeared to be completely protected against the scrapie. They died from unrelated causes between 500 and 707 days after they were "inoculated" with the drug.
Mice who received no PS died of scrapie within 428 days.
The incubation period for scrapie was increased by up to 66% for doses of PS as small as 250 micrograms.
The researchers say further studies are now needed to test whether PS can reduce the risk of CJD.
Dr Moira Bruce, head of pathology at the institute, said the previous research had shown PS to be effective in treating scrapie, but not in such small, single doses.
The Edinburgh research is also the first time that animals have been successfully treated after being infected. Previously, they were inoculated before being infected with the disease.
Dr Bruce said: "This research shows that a very small dose can produce really quite a dramatic effect if you get the time right."
Dr Bruce warned, however, that much more work was needed before the drug was used on humans. She said there would be problems identifying which people were carrying the CJD infection soon enough to ensure PS could work.
CJD, like BSE and scrapie, causes the brain to develop a spongy texture known as spongiform encephalopathy.
At present, there is no treatment to slow or halt nv-CJD, and the diagnosis is usually made when patients are terminally ill.
During the long incubation period when there are no symptoms, there is a risk that the infection may be transferred by blood transfusion, treatment with blood products, transplantation or reuse of surgical instruments.
PS is already licensed in the US for the treatment of a form of cystitis.
Microbiologist Dr Stephen Dealler, of Burnley General Hospital, is working on a treatment for CJD in humans.
He said the Edinburgh research was "very exciting".
"Pentosan does not just prevent the disease from progressing in animals, it actually gets rid of it," he said.
"The potential importance of this drug to humans cannot be underestimated."