MEMES
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Regenerative medicine
It’s an old idea, but it’s still going strong – getting stronger if anything. The idea that it might be possible to ‘repair’ damaged human parts -simply by re-growing them.
Without any medical assistance, an otherwise healthy human can re-grow around 60% of the liver, small amounts of bone, blood, and outer layers of skin - and very young children can re-grow finger tips.
But several other animals, especially amphibians, can re-grow entire limbs. The undisputed champion being the Mexican axolotl – which can re-grow all four limbs, an eye, half a jaw, end even 25% of its heart.
The axolotl has been investigated for many years because of this remarkable ability. In fact, there are now many more of them living in labs across the world than in the wild.
Here’s a famous Axolotl movie file, showing limb re-growth.
http://darwin.bio.uci.edu/~mrjc/
The current theory is that axoltl’s don’t, in fact, have some special ability - it’s just that the facility has been ‘turned off’, genetically speaking, in other species – mammals included. Hence the intense interest from geneticists. If the theory is correct, and if it one day becomes possible to identify this gene(s) and ‘reset’ it – then it may well be possible for humans to re-grow limbs, organs, etc.
Although they don’t work at the genetic level, there are already several compounds – such as Bone Morphogenic Protein-7 ( BMP-7) – which have been found to help damaged bone re-grow. It was recently discovered that the same group of chemicals can induce re-growth of kidney cells in animals. In the future, it may be possible for human patients with damaged kidneys to re-grow at least a percentage. Even 10% is enough to mean freedom from the dialysis machine.
Without intervention though, there’s not all that much that a normal mammal can do morphogenic–wise ( exceptions are deer, which re-grow substantial antlers each year, and an obscure breed of lab-mice called MRL, which can re-grow up to 15% of a damaged heart ).
Current theory doesn’t explain however, why the gene(s) ever became ’switched off’ . Surely it would be a great advantage to any species ? Maybe it was just an unfortunate genetic accident.
Regenerative medicine obviously has enormous implications for the creation of entirely new forms of treatments for many serious diseases. It may still be 40 or 50 years away though.
( It also raises possibilities for enthusiasts of assisted immortality. No animal as yet has the ability to regrow a brain though – so we could face a future where countless people have re-grown grade-1 new bodies – but who are essentially senile.)
All you need to know about axolotl’s
http://www.caudata.org/axolotl/
