Scientists in Oxford have found a human antibody which fights diseases such as Alzheimer's and CJD.

Working with the University of California, in America, researchers at Oxford University's Glycobiology Institute believe the discovery, known as D18, could be the key to future treatments for neuro-degenerative disease.

There are no cures for Alzheimer's or CJD, both of which attack the victim's brain. Alzheimer's commonly affects the elderly and is a form of dementia. CJD is the human form of BSE, which affects cattle. It is thought that humans contract the disease after eating infected meat.

The scientists, who have published their findings in today's Nature journal, discovered that D18 can bind to infectious particles -known as prions - which attack the brain and cause disease by killing cells and leaving holes.

By doing this, the antibody prevents the disease from spreading and clears away the infection.

During the research, it was found that D18 had cleared up the prions to undetectable levels within one week.

Prof Raymond Dwek, Glycobiology Institute director, said the research showed that the antibody was a "powerful weapon" in the search for treatments.

He said: "This is an excellent example of basic research leading to insights into therapy. The use of neutralising antibodies in treating a variety of diseases is an exciting approach."