A team of researchers from Kyoto University, Japan has announced the world's first human trial using a kind of stem cell to treat Parkinson's disease, building on earlier animal trials. The team plans to inject five million induced Pluripotent Stem (iPS) cells which have the potential to develop into any cell in the body, into patient brains.

The iPS cells from healthy donors will be developed into dopamine-producing brain cells, which are no longer present in people with Parkinson's disease.

The clinical test with seven participants aged between 50 and 69 will begin this week. The university will monitor the conditions of the patients for two years after the operation.

The human trial comes after an earlier trial involving monkeys.

Osaka University is also planning a clinical test to treat heart failure by using a heart muscle cell sheet created from iPS cells.