PDA

View Full Version : Cell Transplants "Restore Sight"



Race
11-08-2006, 07:03 AM
Cell transplants 'restore sight'

Cell transplants have successfully restored vision to mice which had lost their sight, leading to hopes people could benefit in the same way.
UK scientists treated animals which had eye damage similar to that seen in many human eye diseases.

They were able to help them see again by transplanting immature retinal stem cells into their eyes.

UK experts welcomed the study, published in the magazine Nature, saying it was "stunning" research.

If the results can be translated into a treatment for human eye disease, it could help the millions of people with conditions ranging from age-related macular degeneration to diabetes.

Once the cone and rod photoreceptors in a retina are lost, they cannot be replaced.

While treatments are being developed which might prevent or delay the loss of these cells, scientists are also seeking to help those already affected.

It is thought the retina is one of the best places to try out cell transplant therapy because photoreceptor loss initially leaves the rest of the wiring to the brain intact.

But previous attempts to transplant stem cells, which can turn into any kind of cell in the body, in the hope that they will become photoreceptors have failed because the cells were not developed enough.

Harvest

In this study, funded by the Medical Research Council, scientists from the University College London Institutes of Ophthalmology and Child Health and Moorfields Eye Hospital transplanted cells which were more advanced, and already programmed to develop into photoreceptors.

The team took cells from three to five-day-old mice, a stage when the retina is about to be formed.

They cells were then transplanted into animals which had been genetically designed to have conditions which meant they would gradually lose their sight - either mimicking the human diseases retinitis pigmentosa or age-related macular degeneration.

The transplants were successful;, the photoreceptors implanted and made electrical connections to the animal's existing retinal nerve cells - key to allowing them to see again.

Tests showed that the mice's pupils responded to light and that there was activity in the optical nerve, showing signals were being sent to the brain.
Dr Jane Sowden, one of the study's leaders, said: "Remarkably we found that the mature retina, previously believed to have no capacity for repair is in fact able to support the development of new functional photoreceptors."

'Not false hope'

To get human retinal cells at the same stage of development, however, would involve taking stem cells from a foetus during the second trimester of pregnancy.

But Dr Robert MacLaren, a specialist at Moorfields Eye Hospital who worked on the research, said they did not want to go down that route.

He said the aim now would be to look at adult stem cells to see if they could be genetically altered to behave like the mouse retinal cells.

There are some cells on the margin of adult retinas which have been identified as having stem cell-like properties, which the team say could be suitable.

Dr MacLaren would be some time before patients could benefit from such a treatment, but he said that at least it was now a possibility.

"Everyday, I sit in my clink and have to tell patients that there's nothing I can do.

"I don't want to give patients false hope. But at least now, if I see a young patient, I can say that there might be something within your lifetime."

Dr Stephen Minger, a stem cell expert at King's College London, said: "I think this is important, superb research - it clearly shows that the host environment is important in directing the integration of transplanted cells."

But Andrew Dick, professor of ophthalmology at the University of Bristol, added: "As with any basic research we have to be careful not to overhype. However this is a stunning piece of research that may in the distant future may lead to transplants in humans to relieve blindness."

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/6120664.stm
Published: 2006/11/08 14:03:44 GMT

Ben
11-08-2006, 07:15 AM
So it's okay now for blind people to restore their sight? Just because they want to see? Well, what if I said I wanted to be a buffalo? I guess I could just inject some cells into myself and become a buffalo! I'm stupid!

Brad N.
11-08-2006, 07:20 AM
Can you imagine if Stevie Wonder got to see before he died?

Bill!
11-08-2006, 07:38 AM
If God wanted these people to see, he wouldn't have bestowed a crushing disease upon them.

Taki Soma
11-08-2006, 07:58 AM
If God wanted these people to see, he wouldn't have bestowed a crushing disease upon them.

same could be said of any disease or even accidents which may kill or cripple people.

Race
11-08-2006, 08:05 AM
So no one wants to discuss the ethics and implications of harvesting cells from a 2nd trimester foetus?

DrMachine
11-08-2006, 08:17 AM
God hates blind people.

Smokinblues
11-08-2006, 08:21 AM
So no one wants to discuss the ethics and implications of harvesting cells from a 2nd trimester foetus?


well, it might be worth discussing if they didn't say in the article that they didn't want to do that.

Race
11-08-2006, 08:54 AM
God hates blind people.
As he went along, he saw a man blind from birth. His disciples asked him, "Rabbi, who sinned, this man or his parents, that he was born blind?"

"Neither this man nor his parents sinned," said Jesus, "but this happened so that the work of God might be displayed in his life. - John 9:1-3

:ninja:
Bible-ninja strikes again!

DrMachine
11-08-2006, 10:36 AM
:ninja:
Bible-ninja strikes again!

exactly

Natty P, Scientific Adventurer
11-08-2006, 10:46 AM
So no one wants to discuss the ethics and implications of harvesting cells from a 2nd trimester foetus?

Not with you.

Race
11-08-2006, 10:48 AM
Not with you.( )*( )

Pia Guerra
11-08-2006, 10:58 AM
What about mothers who have a miscarriage in the second trimester? Wouldn't it be a positive thing to be able to donate cells much in the same way a full term child or an adult can have their organs donated when the die? Many parents and next of kin find comfort in knowing their offspring live on in some way.

Race
11-08-2006, 11:52 AM
What about mothers who have a miscarriage in the second trimester? Wouldn't it be a positive thing to be able to donate cells much in the same way a full term child or an adult can have their organs donated when the die? Many parents and next of kin find comfort in knowing their offspring live on in some way.That's probably the best way to go about it - though I don't think very many miscarriages happen after the first trimester, IIRC - but that's up the parents.

Ray G.
11-08-2006, 12:00 PM
This is just plain awesome is what it is.

JBElliott
11-08-2006, 12:10 PM
What about mothers who have a miscarriage in the second trimester? Wouldn't it be a positive thing to be able to donate cells much in the same way a full term child or an adult can have their organs donated when the die? Many parents and next of kin find comfort in knowing their offspring live on in some way.


That's probably the best way to go about it - though I don't think very many miscarriages happen after the first trimester, IIRC - but that's up the parents.

It depends on three things: (1) How many stem cells are harvested from miscarried fetus'; (2) how many second trimester miscarriages are there; and (3) is there some other source for the stem cells.

(1) Anyone know that answer?

(2) It might not be common, but in a large population even a small percent can be a large number. This type of practice would be very similar to organ donation.

(3) There are other sources for stem cells that are being found.