DARPA Sponsoring Limb Regeneration Research

fragmentate writes "Wired News is reporting: 'In response to the hundreds of soldiers coming home from war with missing arms or legs, Darpa is spending millions of dollars to help scientists learn how people might one day regenerate their own limbs. Prosthetics are getting better all the time, but they will never be as good as the limbs we were born with. So two teams of scientists at 10 institutions across the country are competing to regrow the first mammalian limb ... The researchers' first milestone is to generate a blastema — a mass of cells able to develop into various organs or body parts — in a mammal.' Apparently this is a relatively new area of research, even Wikipedia's stub on blastemas is very terse."

Comments

Stub.

[Wordsmith]

Wikipedia's stub. I get it. Hah.

Re:Stub.

[Darkman, Walkin Dude]

Jokes aside, if they can regenerate limbs, surely its just a hop skip and a jump to regenerate organs? If we can do that, immortality is just around the corner...

Re:Stub.

[Stile 65]

First of all, TFA says that one of the two teams of scientists working on this is basing their work on the MRL mouse, which can and does regenerate internal organs, including severed spinal cords.

Second of all, this may increase lifespan, but would not provide immortality. Human cells stop reproducing after a certain number of reproductions. The cell chromosomes have end-cap like things called telomeres which are shortened with each mitotic cycle. When they get too short, the cell stops reproducing. This is to prevent too many mutations from accumulating after a while. Generally, if cells divide without shortening the telomeres, they're usually malignant tumor cells. So to get immortality, you'd have to augment the mitotic cycle to a) "spellcheck" the chromosome copying, and b) prevent the telomeres from being shortened.

Re:Stub.

[javilon]

a) "spellcheck" the chromosome copying, and b) prevent the telomeres

b) is easy, you can shut off telomerase for a while(http://www.pubmedcentral.nih.gov/articlerend er.fcgi?artid=14711&tools=bot)

Re:Stub.

[izomiac]

Drastically reduce but not eliminate. IIRC mutations tend to occur once every 600,000 base pairs, so that would mean that replication is about 99.99983% accurate. After 100 divisions the genome of a cell would only be 99.983% accurate, so it'd have about 1 error every 500 base pairs. Given the size of most genes/proteins, that cell should have some serious problems or be cancerous. (I don't know the "maximum" number of divisions, it could be more or less, but you can see the problem.) Not to mention, mutation accumulation is just one part of aging. Now, if we could take our genome and add some parity base pairs and some redundancy checking proteins we might be able to address that problem. But that's far beyond our level of genetic engineering (AFAIK).

Re:Stub.

[mrogers]

If a person lives for 1000 years and their personality continues to evolve, to what extent can the 1000-year-old individual be regarded as "the same person" as, say, the 30-year-old individual? Are you the same person you were 10 years ago, or 20? What would 1000 years of experience, combined with 1000 years of cultural, political and technological change, do to the human personality?

Reminds me of The Forever War

[bhunachchicken]

(WARNING - SPOILERS)

When William Mandella lost his leg in an accident he was under the impression that he would simply be given an artificial one and would then be free to persue a semi-normal life. To his horror he discovers they'll simply grow him a new leg and chuck him right back in to active duty... :)

Re:Reminds me of The Forever War

[nosredna]

New moderation ideas are a dime a dozen, but I have to throw one in for this...

+1 Creepy but probably true

Don't underestimate prosthetics

[Chandon Seldon]

Prosthetics are getting better all the time, but they will never be as good as the limbs we were born with.

Why not? I see no good reason why competent engineering can't eventually beat a chunk of meat.

It's not like we were intelligently designed... we evolved. Evolution will tend to produce good solutions to problems, but it will hardly ever produce the best possible solution. Once we get nerve-circuit interfaces down, we should have no problem outengineering most of the human body.

Re:Don't underestimate prosthetics

[Darkman, Walkin Dude]

we should have no problem outengineering most of the human body.

Yes and then the batteries in your cyberleg run down and you have to haul the entire 40 kilo hunk of metal across town in the rain... on one leg. Besides that you are forgetting that the limbs aren't seperate components of the body; its all interlinked. Its no good having an arm able to flip over a truck, your torso would compact and tear itself apart if you didn't just rip the thing off, nerve circuits and all. The only real option for enhanced performance cybernetics would be a Ghost in the Shell effort, with full body replacement except for the brain. If you can manage that, without regular maintenance and some sort of 50 year power source, I'll admit you have a point.

Re:Don't underestimate prosthetics

[Darkman, Walkin Dude]

That's a bold statement of fact, considering even the most avid proponents of evolution refer to it as "theory".

Not a great troll... poignant, with a hint of maple... but lacking in the body and depth that a really rich, warm troll should have... I'll have to give this one star, I'm afraid.

Re:Don't underestimate prosthetics

[daeg]

Just because we may eventually out-tnature doesn't mean the thousands of injured soliders and civilians want part of their body replaced with robotics if they could have the option of a new, real limb.

There is also no reason both areas of research can't operate simultaneously, nor anything that is restricting them from working coopoeratively.

Re:Don't underestimate prosthetics

[Chandon Seldon]

Consider that cyberleg. We can build it to run off glucose in order to avoid it running out of batteries. We can easily give it the performance characteristics of an athlete - we know the human body can take that. It will never get out of shape. Assuming it has sufficient glucose (which is easy to introduce to your body, especially if you deal with the insulin thing right), it will never get tired.

Now, that's no car-tossing cyberarm, but it's definately an improvement on the stock equipment. The downside is maintnence, but anyone who's paid too much attention to cyberpunk settings knows that - and that can be reduced with better engineering.

Wikipedia's stub on blastemas is very terse

[Anonymous Coward]

I think it would be more accurate to say Wikipedia's stub on blastemas is embryonic.

can we grow some extra limbs in advance?

[porky_pig_jr]

so, say, if one hand is blown off, I still have a few more left, no need to rush to hospital. an extra head won't hurt either. (with a possibility of starring in Hitchhiker).

I sense a disturbance in the Force

[GungaDan]

as if a million stumpfuckers suddenly cried out in protest.

How about some hair regeneration?

[glrotate]

Let's focus our efforts on something a little more important.

Thanks.

Potential for new cybernetic prosthetics

[Colgate2003]

they will never be as good as the limbs we were born with

Not quite as good, but I just interviewed someone about new research into interfacing neurons with electronics that could lead to Luke Skywalker-like replacement limbs. Harvard researchers have figured out a way to directly read and write to a neuron with digital electronics.