Stem cells that could be used to restore hearing have been successfully created, scientists have said.



A Sheffield University team took stem cells from embryos and converted them into cells that behave like sensory hair cells in the human inner ear.

Their discovery could ultimately help those who have lost hair cells through noise damage and some people born with inherited hearing problems.

But any cure is still some years away, experts told the journal Stem Cell.

The Sheffield team is now working on the next stage of the research to check if the cells can restore hearing.

This research is incredibly promising and opens up exciting possibilities
Dr Ralph Holme, RNID

Currently, hair cell damage is irreversible and causes hearing problems in some 10% of people worldwide.

Embryonic stem cells could change this because they have the unique ability to become any kind of human cell.

Not only could they be used to replace the lost hair cells, but also any damaged nerve cells along which the signals generated by the hair cells are transmitted to the brain.

But the use of stem cells is controversial - opponents object on the grounds that it is unethical to destroy embryos in the name of science.

Lead researcher Dr Marcelo Rivolta, said: "The potential of stem cells is very exciting. We have now an experimental system to study genes and drugs in a human context.

"Moreover, these cells would help us to develop the technologies needed to deliver them into damaged tissues, such as the cochlea, in order to restore the different cell types.


Is this the ultimate upgrade for the iPod generation?
Professor David McAlpine
Ear Institute

"This should facilitate the development of a stem cell treatment for deafness."

Dr Ralph Holme, director of biomedical research at RNID, said: "Stem cell therapy for hearing loss is still some years away but this research is incredibly promising and opens up exciting possibilities by bringing us closer to restoring hearing in the future."

Vivienne Michael of Deafness Research UK said: "This study highlights the importance of stem cell research.

"In addition to the future potential for restoring hearing with stem cell therapy, the recent research success means that we may now have better ways to test the efficacy and toxicity of new drugs on auditory cells."

Professor David McAlpine, director of the Ear Institute, University College London, said: "Is this the ultimate upgrade for the iPod generation?

"The possibility of regenerating the sensory cells of the inner ear, so easily damaged by exposure to loud sound, has just moved a step closer.

"If scientists can find out ways to deliver new cells to the inner ear, and wire them up correctly, then "plug and play" hearing could be the future."

A woman who went on an intense grapefruit-based diet developed a blood clot in her leg and risked losing the limb, US doctors have reported.



The unusual case, written up in the Lancet medical journal, occurred in Washington state in November last year.

Medics concluded grapefruit had affected the way the 42-year-old's body processed her contraceptive pill.

A UK expert stressed this was an unusual case, but said extreme diets may have "unpredictable consequences".


Three days of grapefruit for breakfast may well have tipped the balance
Dr Lucinda Grande, Providence St Peter Hospital

In November 2008, the woman came to the casualty department of the Providence St Peter Hospital in Olympia, Washington state.

The day before, she had gone on a long car journey, after which she felt pain radiating from her lower back down to her left ankle.

When she arrived at the hospital she was experiencing difficulty walking, shortness of breath, and light-headedness.

By the next day her left leg had turned purple.

The woman was generally in good health but was slightly overweight and had decided to diet.

Three days before falling ill, she had begun a crash diet which included eating 225g of grapefruit each morning, after rarely eating the fruit in the past.

When doctors examined her, an ultrasound scan confirmed the woman had a large blood clot within the veins of her left leg, which stretched from her hip down to her calf and she was deemed to be at risk of losing her leg because of gangrene.

The woman was given clot-busting treatment and had a stent, a kind of tube, fitted in order to widen her vein.

Fruit block

The doctors treating her said a number of risk factors had contributed to the woman developing the clot.

She had an inherited disorder which increased her risk, as did being on the combined Pill. Being immobile in a car probably also contributed to the clot forming.

Writing in the Lancet, the authors led by Dr Lucinda Grande, called it a "constellation of potential risk factors".

But they added: "The increased [oestrogen] serum concentration due to her three days of grapefruit for breakfast may well have tipped the balance."

They suggest the fruit blocked the action of a key enzyme that normally breaks down the form of oestrogen in her contraceptive.

Dr Trevor Baglin, a consultant haematologist at Addenbrooke's NHS Trust in Cambridge, said: "From this case study it appears as if the grapefruit enhanced the thrombotic effect of the contraceptive pill in the presence of a genetic predisposition.

"However, it is worth pointing out that this is a single case study and a very unusual case at that.

"I would suggest that any extreme diets should be avoided because they can have unpredictable consequences."