Stem cells grown from dead bodies

Stem cells may one day provide new treatments

By BBC News Online's Helen Briggs

American scientists have grown brain cells harvested from dead bodies.

They say cadavers are a potential source of stem cells, the master cells that have the ability to develop into all the body's different tissues.

Doctors believe it might one day be possible to use stem cells to repair brain damage caused by strokes or Parkinson's disease.

But the research has been overshadowed by ethical objections about the source of the tissue, as well as legal bans to such work in some countries.

Master cells

Stem cells are the body's master cells, having the ability to "differentiate" into a wide variety of cells used for different purposes in the body.

Researchers have been growing rodent brain cells in the lab for many years

Experiments in rodents have shown that stem cells from embryos or adults could potentially treat a range of neurodegenerative disorders, such as Alzheimer's, Huntington's and Parkinson's.

However, the source of stem cells for human medical research has raised ethical concerns.

Many researchers believe cells taken from embryos are the best candidates for developing new medical treatments. However, the work is banned in some countries because of ethical objections.

Recent work has shown that adult stem cells could provide a viable alternative.

Now, a US team has shown that dead bodies can also be used as a source of stem cells.

'Careful evaluation'

Writing in the scientific journal Nature, a team led by Fred Gage at the Salk Institute in La Jolla, California, report a technique for sourcing stem cells from human post mortem samples and surgical specimens.

When placed in a succession of solutions in the lab, the tissue of two patients - an 11-week-old baby boy and a 27-year-old man - yielded immature (progenitor) brain cells.

Careful evaluation and consideration of the relative merits of post-mortem or adult-derived cells and foetal progenitor cells will be necessary

Fred Gage, Salk Institute

Since then, the team has successfully used the technique on other samples taken from people from different age groups, even from tissue extracted nearly two days after death.

But the scientists warn that the work raises "complex ethical and societal issues" which must be carefully addressed.

"Careful evaluation and consideration of the relative merits of post-mortem or adult-derived cells and foetal progenitor cells will be necessary," they write.

Ethical issues

Professor Peter Andrews of the University of Sheffield, UK, leads a research team that works on stem cells.

"There do appear to be true stem cells in the brain that do under certain circumstances renew themselves," he told BBC News Online.

"In theory, if you had a source of such immature brain cells you might be able to treat something like Parkinson's disease."

It's very important that we have a full public discussion about progress in this important field

Professor Brian Heap, Royal Society

He said the use of cadavers as a potential source of stem cells raised a different set of ethical issues from those associated with using stem cells from embryos.

Britain's Royal Society recently suggested in a report that one day people could donate their stem cells in much the same way that they are currently asked to offer their organs for transplant.

But the vice president of the Royal Society, Professor Brian Heap, said a raft of questions still needed to be answered before such issues could be addressed.

He told BBC News Online: "It's very important that we have a full public discussion about progress in this important field."