Increasing Stem Cell Production For Faster Healing 67
Wandering Wombat tips a BBC story about researchers from Imperial College London who were able to stimulate stem cell production by a factor of 100 in the bone marrow of mice. Such stem cells are released by the marrow to help with the regeneration of damaged bone and tissue. "Techniques already exist to increase the numbers of blood cell producing stem cells from the bone marrow, but the study focuses on two other types — endothelial, which produce the cells which make up our blood vessels, and mesenchymal, which can become bone or cartilage cells." The scientists hope that the increased production rate could be used to greatly speed tissue repair and to allow recovery from wounds that would otherwise be too severe. "There are also hopes that the technique could help damp down autoimmune diseases such as rheumatoid arthritis, where the body's immune system attacks its own tissues. Mesenchymal stem cells are known to have the ability to damp down the immune system." The full research paper is available at Cell Stem Cell.
Space and Medical discovery (Score:4, Insightful)
I can recall this Star Trek episode where people on a planet never aged, but the horror of it was that because nobody died, the planet filled up with people so that no beauty could flourish.
Medical discoveries like this one, by increasing the level of reproduction rates in stem cells by a factor of 100, remind me that eventually humanity will cure death. However, unlike that fateful society on that distant memory of a Star Trek episode, we have INFINITE stars and potential to flourish outside of our known universe, and therefore we should not fear immortality.
Uhhh....no. (Score:4, Insightful)
Just not having children is a much simpler solution---the absurd premise of "The Mark of Gideon" was that these people couldn't be sterilised, they healed so well. That's unlikely, with human beings---anyway, how is it that one has med tech good enough to create this sort of super-healing (which seems unlikely ab initio) but can't make it be contraceptive at the same time.
Anyway, there is no evidence that enough of us can get into space fast enough to make a difference on Earth. See here [antipope.org] for an elaboration.
Technically, there is no indication that there are an "infinite" number of stars, and even if you mean "planet" by "universe", no proof yet that we ca flourish off-world (I like my bone mass, especially around my spinal cord.)
Cancer? (Score:3, Insightful)
This is awesome. Biology is doing amazing things.
I do have one worry, though: Stem cells, some research is starting to indicate, are a double-edged sword. On the one hand, they allow new tissue to grow, but on the other, that new growth may end up being cancerous. One wonders whether the fact that we don't naturally produce stem cells at this rate reflects the optimal balance that evolution has found.
If we could control and cure (or prevent?) cancer reliably, however, this sort of technology would be great.
Re:Cancer? (Score:5, Insightful)
There is no "optimal balance" with evolution. It does not work that way. Traits that lead to reproductive success are continued those that do not are not. This is it.
You getting cancer at 80 has zero impact on the odds that your offspring will succeed or not, therefore they is no selective pressure for or against it.
Re:Cancer? (Score:3, Insightful)
In fact, if the social mechanisms for inheritance of worldly wealth have been in place long enough (and IIRC the sumerians made wills), there might be advantages to your offspring for you to die, but not so young you haven't accumulated a bunch of stuff to give to them.
Re:Telomeres (Score:3, Insightful)
I'm not a biologist, but wouldn't this shorten your life span?
I remember reading about Telomeres [wikipedia.org] and how they shorten as you age (and this is why you age).
Would this accelerated growth/generation cause these to shorten at a more rapid pace?
Short answer: probably not. Telomere shortening does occur, and it does limit the number of divisions that certain cells can undergo. However, as I understand it, it's not the primary cause of aging symptoms. In fact, the lengthening of telomeres is associated with many kinds of cancer - not eternal youth. One gene that may be at least partially responsible for aging is Klotho. [wikipedia.org] Experiments have been done in mice doing both knockdown expression and upregulation of the gene. Also, this is the gene that was making Snake age prematurely in MGS4.
Menopause is different (Score:5, Insightful)
Menopause is actually a more complex thing, and actually had _zero_ impact on human evolution back when it mattered.
The problem is that all mammal females are born with a finite number of "eggs". Usually more than enough for an average life span. Again, it's actually controlled by evolution, or rather natural selection. If you have too few it's a handicap, so nature tends to select those with more. But here's the important part: enough for your expected life span. If a cat lives for, say, 3 years outside, there's no evolutionary pressure to have enough ovules for 30 years. If an ape lives for an average 20 years, there is no evolutionary pressure to pre-produce enough ovules for 300 years.
So basically all you really see there is that the life span of our ancestors was _much_ shorter, back when we evolved into humans.
As late as the Old Kingdom period in Egypt -- and that's already talking about 5000 years ago, out of 200,000 that Homo Sapiens existed for, or the _millions_ leading to Homo Sapiens -- if you got past the high infant mortality, the median age for death was in the mid-20's for women. (And mid-30's for men.)
And just to stress it, I'm not talking about "life expectancy at birth" (which would include the dead babies), but the actual second peak of the age-at-death curve. We have a ton of records (plaques, scrolls, etc) detailing when someone died, and if you plot X = age, Y = number of such records dead at that age, you get a scary spike in the first 3 years of age, then a second peak in the mid 20's for women, and mid-30's for men.
So that was the number of years that you needed ovules for. The average women got married at 12 and died at, say, 24. That's 12 years of being fertile. That's all the ovules it needed. Having enough of them until the age of 60 is already a _massive_ margin for the case she lived longer. It's having 4 times more than the average will ever need.
(Actually, even more. Ovulation is inhibited while you're pregnant or have someone sucking milk out of your breast, as a safety. So someone making an average of, say, a child every 2 years and nursing each for a year, would use up only a fraction of what a modern woman uses.)
At any rate, an ultra-tiny minority lived long enough to reach menopause. There was _no_ evolutionary pressure to push it until later.
What you see is a relatively modern age phenomenon. The life expectancy has risen so dramatically, that the women actually get to reach the end of that counter. What was once a 300% margin, now is actually less than enough.
In computer terms: it's a buffer overflow error. Literally.
But the same modern age all but stopped evolution. And nobody makes a child every 2 years any more. People stop at a much lower number, menopause or not. There is no natural selection to change that any more.