A clinical trial of brain stem cells to treat strokes is set to move to its next phase.
An independent assessment of the first three patients to have had stem cells injected into their brains at Southern General Hospital in Glasgow has concluded that the procedure has had no adverse effect.
The BBC reports an elderly man was the first person in the world to receive this treatment last year. Since then it has been tried out on two more patients, who have been given very low doses in trials designed to test the safety of the procedure.
The assessment paves the way for the therapy to be tested on more patients to find a new treatment for stroke.
The hope is that the stem cells will help to repair damaged brain tissue.
More patients will be given progressively higher doses over the next year.
Larger trials are at least 18 months away.