A common drug used to treat cystitis could act as a shield against the human form of BSE, a scientist has claimed.

Dr Stephen Dealler, a microbiologist at Burnley General Hospital in Lancashire, told the BBC's Newsnight that he has been in talks with the government about using Pentosan to treat new variant Creutzfeldt-Jakob's Disease (CJD).

Dr Dealler said he thought it was worth testing the drug on the children of people who have died of CJD and people who need blood transfusions.

"It's an amazing drug...there are some obvious groups that would benefit from this kind of drug," he said, citing the case of childrne of Michelle Bowen, a 29-year-old who died three years ago shortly after giving birth to her third child.

"I would expect her child to have been exposed to the disease, just like people who may have been inoculated with the disease through blood transfusions, gammaglobulin or anti-D."

Scrapie

Experiments conducted in the 1980s have shown that Pentosan reduces scrapie in mice.

Some of the mice injected with the drug did not die from the disease and they lost their infectivity.

"It was as if the mice had been cured," said Dr Dealler.

Scrapie-infected sheep were added to cow food

Cow meal made from sheep infected with scrapie is thought to have caused BSE.

Dr Dealler believed the evidence was strong enough that Pentosan could help people at risk from CJD, which may take more than 30 years to develop, and he urged the government to go ahead with trials.

Other scientists have called on the government to test Pentosan in relation to CJD.

Dosage

Chris Bostock, director of the government's Institute of Animal Health and a member of the committee that advises on BSE and nvCJD, said he wanted experiments on mice to show whether taking the drug orally or injecting it made any difference.

And he wants to see if there is any optimum dosage for treating nvCJD.

But he thinks it is too early to start prescribing the drug to humans.

Philip Comer, of Det Norske Veritas, risk assessment advisors to the government, called for further investigations into Pentosan.

"It appears that Pentosan could be a useful risk reduction measure and certainly is worthwhile investigating further, but I think there's quite a lot of work that needs to be done to demonstrate that," he said.