A British company has asked American authorities for permission to trial a cure for stroke using brain cells from an aborted foetus. Although opponents of the experiment say that it is a "sick proposal", the company, ReNeuron, says that the foetal cells will multiply rapidly and repair brain areas damaged by strokes. The procedure has already worked with rats, it says.

Safety is a major concern for ReNeuron. The transplanted cells are genetically modified and could potentially multiply wildly and form tumours. However the company says that this is completely under control. It also claims that only one batch of foetal tissue will be needed to treat unlimited numbers of stroke patients. "We only take one single piece of tissue and for that we can grow up enough cells to potentially treat all eligible patients," says Dr Eric Miljan, ReNeuron's head of stem cell discovery. "And we never have to go back to that tissue again. We can provide a renewable source of cells in order to treat a large patient population."

Pro-life lobbyist John Smeaton denounced the proposal. "He told the BBC that "It involves cannibalising an unborn child. It's an unethical in every way - killing one member of the human race to help another."