Damaged DNA - the genetic blueprint from which cells are made - can lead to cancer or the death of cells.

Researchers working for the Imperial Cancer Research Fund say cells have more than one way of fixing broken DNA molecules. Which method is used is determined by which protein discovers the damage.

If scientists can control gene repair mechanisms, they have a better chance of adding their own genetic material - the key to successful gene therapy.

Dr Stephen West, who led the research, said greater understanding of such mechanisms "could provide a powerful new tool in the study of cancer".

Quitting marijuana causes aggression

People who smoke marijuana every day become more aggressive when they quit, researchers have said.

Dr Elena Kouri and colleagues at Harvard University used computers to test volunteers who were unaware they were being observed for aggression.

The subjects could either press a button to score points for themselves, or another button to remove points from an opponent.

The tests took place over 28 days, during which none of volunteers had cannabis. The heaviest users of cannabis showed the greatest levels of aggression.

Writing in the journal Psychopharmacology, Dr Kouri said: "Most of the studies that have been published on marijuana withdrawal have relied on self-report."

She said her study was the first test to verify this objectively.

Care blueprint for diabetes

The government is to set up care blueprints for patients with diabetes.

National Service Frameworks are already in development for coronary heart disease, mental health and care for the elderly.

They will set the standards of care patients can expect and will be enforced by the Commission for Health Improvement.

The framework will be developed over the next two years.

Announcing the move, Health Secretary Frank Dobson said: "People affected by diabetes, wherever they live, need to have convenient access to top quality, modern standards of care and treatment. That doesn't always happen at present. But in future, it will."

NHS acts on Y2K concerns

The NHS Executive is to increase its monitoring of moves towards Year 2000 compliance in hospital equipment.

There have been concerns that the NHS could collapse as the millennium starts because it is so reliant on technology.

In the run up to the date change, the NHS will be required to produce reports on its progress towards year 2000 compliance every two months instead of every quarter.

Alasdair Liddell, NHS Executive Director of Planning also said every health authority will have to draw up a local winter planning group to ensure continuity of care over the extended holiday period.