Stem cells could improve hearing

From: BBC News, UK - Nov 22, 2004

Geoff Adams-Spink
BBC News Online disability affairs reporter

A research scientist from Sheffield University is using embryonic stem cells which he hopes could be part of a new treatment for deafness in people with certain types of hearing loss.

Dr Marcelo Rivolta is using stem cells from embryos and trying to learn how to convert them into cells for the human ear.

"We're talking very early stages," Dr Rivolta told BBC News Online.

"But this sort of treatment could eventually help people who've lost their hearing as a result of degeneration of the cochlear, those who've lost hair cells because of loud noise or drug treatments, and people with certain genetic conditions."

He was addressing a one day conference in London organised by the Royal National Institute for Deaf People (RNID) which brought together scientists from around the world working on treatments for hearing loss.

Dr Rivolta said that his research had shown that stem cells from sensory nerves could be regrown in a damaged part of the ear which, potentially, could restore a person's hearing.

"What we are trying to do in the lab is to use chemicals to tell a cell to do a particular task - in other words to mimic what normally happens in the embryo."

Dr Rivolta estimates that it will be between 10 and 15 years before such treatment could be made available, but he says the early indications are "exciting".

A treatment that could be available much sooner was explained by Jonathan Kil of Sound Pharmaceuticals - a company which, he says, is the first in the world to try to develop drugs to treat hearing loss.

Sound Pharmaceuticals has already registered one of it's products - code named SPI 1005 - with the Food and Drugs Administration and has taken out a patent on it.

If clinical trials with the US army are successful, SPI 1005 could be used to treat people whose hearing has been damaged as a result of exposure to excessive noise.

Eighty soldiers involved in live weapons training with handheld rifles are taking part in the first trials.

"Even with state of the art protective devices a significant proportion will develop both temporary and permanent hearing loss as well as tinnitus," said Mr Kil.

"Having the drug on board before, during and after rifle training could prevent and treat the hearing loss associated with the occupational exposure."

The company hopes that a product could be on the market in about three years from now.

It estimates that in the US alone, 30m people are exposed to noise that could damage their hearing every day.

A Danish researcher told the conference of his company's efforts to develop a drug to counteract tinnitus - noises which are heard but which have no external sound source.

"Tinnitus is a lot like the pain experienced by people who have had a limb amputated," said Mads Korsgaard, from a company called NeuroSearch.

He says that neuronal circuits in the brain somehow become altered which creates a perception of sound.

The company hopes that by identifying and then stimulating the parts of the brain that cause tinnitus, its effects will be dampened if not alleviated entirely.

But a chemical cure for tinnitus is still a long way off - it will be at least a decade before NeuroSearch's work will bear fruit.

Story from BBC NEWS: http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/4033383.stm

Published: 2004/11/22 18:01:07 GMT

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