Human Limb Regeneration a Possibility?

SablKnight writes "This NY Times article (free reg. req.) says maybe. Apparently research is being done in parallel with the more controversial stem cell implantation to attempt to regenerate missing parts in humans. Though this has been a subject of mild interest for centuries, serious research started much more recently, when an experiment involving mice suffered a setback. 'A few years ago, Dr. Ellen Heber-Katz, an immunologist at the Wistar Institute in Philadelphia, was conducting an experiment with those mice, which develop a disease similar to lupus. As is common, Dr. Heber-Katz punched a pattern of holes in each mouse's ear to so she could tell which mouse was which. Three weeks later, she said, when she checked on the experiment, 'there were no ear holes.'' A quick google search reveals similar stories about Dr. Heber-Katz' research in other publications, such as the Science Daily and Nature."

stemcells

[virtualXTC]

Correct me if I'm wrong, but I though the idea behind current stemcell research was regeneration with out having to "graft" any thing on, such as spinalcord regenaration. I wouldn't think it would be practical to try to graft a whole arm on, unless you sample the patients DNA and encode the stemcells with it to oppose rejection problems.

evolution?

[tid242]

Scientists wonder why the ability to regenerate has not spread more widely through evolution...

...the advanced immune systems of higher life forms may mistake rapidly proliferating cells for cancer and kill them.

i find this a really interesting idea. Especially given that most cancers are not seen until after people are at an age where they generally have children (you've passed your genes on before you die of cancer). If you were to look at our pre-historic counterparts: if their life-expectancy were 20 years old and they had most of their offspring starting at 10-12 (these numbers are mostly guesswork on my part) then i would tend to think that evolutionally being able to regrow lost arms and legs would outweigh the ability to ward off cancer that doesn't strike until they're 25...

This is much the same as the differences between the rates of Progeria and Huntington's disease in people (people with Progeria don't have kids, but people with Huntington's do as the onset isn't until their 40's) even though, they're (apparently) similiar genetic abnormalities (ie in population genetics not taking into accout inheritence, their incidences should be equal)...

But getting back to regen/cancer: Of course there would be a fine balance between the two and figuring this out would involve lots of statistics and things my noggen doesn't compute so well, but i do find it interesting that there's so little regeneration in people.

conversely to my first point, since most regeneration would have probably been selected for, to take place before child-bearing age, and as we've advanced culturally and civically (child-bearing age) has markedly increased, and it's doubtful that missing a leg destroys your chances of having offspring if you live with a family in a cottage as opposed to running through savannas away from man-eating beasts and the like, maybe all this makes sense... (did you understand my convoluded run-on sentence?).

-tid242