Researchers in Texas say they have found a way of prolonging the life of human cells. They say the breakthrough will not allow people to live longer but it may in time help to slow down the ageing process. The scientists at the University of Texas inserted a gene in a number of cells which allowed some of them to continue dividing. When a cell stops dividing it dies. Washington Correspondent, Tom Carver reports:

Most human cells divide about 70 times during a lifetime. Every time they divide, the protected end of the cells' chromosones shortens.

Eventually it becomes too short to protect the chromosone. The cell stops dividing and dies.

What the scientists succeeded in doing was inserting a gene into a number of human cells thereby preserving the cells protective ends. We strong suspect said one scientist that these cells have been immortalised.

The team stresses that it has not discovered the key to everlasting life but says the discovery may help in combatting certain diseases. Doctor Jerry Shay is one of the team's biologists.

It gives us the ability to take a cell from a human being, experimentally rejuvenate it in the laboratory environment and then give that cell back to the individual. This can include such diseases such as muscular dystrophy, perhaps treating burn patients.

This could treat degenatory diseases of the eye such as macular degeneration. But critics warn that the process could lead to cancer.

Cancerous cells also reproduce beyond their natural life and some scientists suggest that the reason cells eventually stop reproducing is to prevent cancer from breaking out. Nonetheless in a country pre-occupied with the idea of extending human life, these concerns have largely been lost in the applause.