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Science Forum Index » Nanotechnology Forum » Nanotech & "Transhumanism"
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| sanman |
 Posted: Wed Nov 12, 2003 4:35 am |
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More on nanotech and life-extension:
http://www.betterhumans.com/Features/Columns/Transitory_Human/column.aspx?articleID=2003-11-10-5
Personally, I don't think little flesh-manipulating nanobots are the
answer to helping us live longer.
I'd say molecular biology is a sufficiently established field unto
itself, so that it can be differentiated from nanotech. The answers
lie in stem cells and DNA-manipulation more than in nano-machines.
I imagine that one day medical scientists will be able to generate an
artificial placenta capable of enveloping and sustaining the brain,
even after the rest of the body has suffered major damage so as to
become unsustainable.
Made out of stem cells, this placenta will initially be put to use in
keeping trauma victims alive, but eventually it will be applied to
keeping rich old people alive, after their feeble bodies have wasted
away.
But then the next leap will be to then use stem cells to re-grow a new
body in the place of the one that has wasted away. The new body would
literally bud and grow from the placenta in the place where the
original torso was once attached.
Once the technique becomes more widespread, you wouldn't have to wait
for old age, because once the brain is isolated by the placenta you
could then even lyse and replace a middle-aged body.
What do you think of the idea? Has anyone ever articulated something
like this before?
I guess my reasoning was around the fact that it is very difficult, if
not impossible, to genetically modify all of the trillions of cells in
an existing adult organism. And in my opinion, replacement or
replenishment of genetic material is fundamental to extending the
lifespand of flesh-and-blood creatures. Because we know that not only
is flesh eroded by environmental factors, but also the integrity of
its genetic information is degraded over time by the very act of
genetic replication (ie. a photocopy of a photocopy of a photocopy of
a photocopy looks fuzzy compared to the original)
Therefore, if you cannot reliably and accurately modify the genome of
each and every one of the trillions of cells in an adult organism,
then the answer is to imitate Mother Nature's own practice of applying
the blueprint to a single cell and replicating it into an entire
organism. Of course, we want to somehow be able to retain the
continuity of our original brain/mind, so we'd have to come up with
something like a placenta/womb to keep our brain healthy and happy
during the transition from old body to new one.
If a womb and placenta can sustain a fetus, could something similar be
artificially engineered to sustain an entire human brain? Plausible,
or not? Comments? |
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| Malcolm McMahon |
| Posted: Thu Nov 13, 2003 10:28 am |
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On 12 Nov 2003 09:35:25 GMT, manofsan@yahoo.com (sanman) wrote:
Quote: I'd say molecular biology is a sufficiently established field unto
itself, so that it can be differentiated from nanotech. The answers
lie in stem cells and DNA-manipulation more than in nano-machines.
I'm inclined to agree.
Quote: I imagine that one day medical scientists will be able to generate an
artificial placenta capable of enveloping and sustaining the brain,
even after the rest of the body has suffered major damage so as to
become unsustainable.
The brain shouldn't prove any harder than any other organ to maintain
separately from the body. However I would picture something more along
the lines of a heart/lung machine to replace the function of the
visceral organs. A placenta is no use without something to interface
with. In fact you could regard the various semi-permiable mebranes used
in heart/lung machines as a kind of artificial placenta.
However I would guess that bio-stasis of some kind would be a better
solution in trauma cases.
Quote:
But then the next leap will be to then use stem cells to re-grow a new
body in the place of the one that has wasted away. The new body would
literally bud and grow from the placenta in the place where the
original torso was once attached.
The thing is: The genome constitutes instructions for growing a human
being from an egg. It doesn't contain instructions for growing a body
onto a brain in a vat. The first elements of the central nervous system
are one of the earliest things to appear in the embryo. In a situation
like morphogenesis every element of the body will affect every other
element. I see the developing body as being like a complex musical
instrument, full of standing waves and resonances.
So to do a trick like this you have to take overall charge of the
largest scales of the morphogenic process. This is were (clinging to the
edges of being on topic here) nanomedicine is likely to be of relevance.
You'd need to take external control of the chemical signals and any
other factors involved in the morphogenic fields.
This would likely involve precise measurements of chemical environment
and precisely controlled release of signal chemicals under external
control. Effectively you have to talk, and listen too, the language by
which cells coordinate their actions.
This is true for any kind of transformation you might want to do on an
adult organism.
Quote:
I guess my reasoning was around the fact that it is very difficult, if
not impossible, to genetically modify all of the trillions of cells in
an existing adult organism.
But you can modify a few and have them replicate to replace existing
ones locally. I see no advantage in doing the whole thing in one go.
Quote: And in my opinion, replacement or
replenishment of genetic material is fundamental to extending the
lifespand of flesh-and-blood creatures. Because we know that not only
is flesh eroded by environmental factors, but also the integrity of
its genetic information is degraded over time by the very act of
genetic replication (ie. a photocopy of a photocopy of a photocopy of
a photocopy looks fuzzy compared to the original)
I've never really been convinced of that, because if DNA damage caused
aging, damage would accumulate down the germ lines as fast as down the
somatic lines and each generation would live shorter lives than the one
before. |
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| Joann Evans |
| Posted: Fri Nov 14, 2003 12:01 am |
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sanman wrote:
Quote:
More on nanotech and life-extension:
http://www.betterhumans.com/Features/Columns/Transitory_Human/column.aspx?articleID=2003-11-10-5
Personally, I don't think little flesh-manipulating nanobots are the
answer to helping us live longer.
I'd say molecular biology is a sufficiently established field unto
itself, so that it can be differentiated from nanotech. The answers
lie in stem cells and DNA-manipulation more than in nano-machines.
I imagine that one day medical scientists will be able to generate an
artificial placenta capable of enveloping and sustaining the brain,
even after the rest of the body has suffered major damage so as to
become unsustainable.
Made out of stem cells, this placenta will initially be put to use in
keeping trauma victims alive, but eventually it will be applied to
keeping rich old people alive, after their feeble bodies have wasted
away.
But then the next leap will be to then use stem cells to re-grow a new
body in the place of the one that has wasted away. The new body would
literally bud and grow from the placenta in the place where the
original torso was once attached.
Once the technique becomes more widespread, you wouldn't have to wait
for old age, because once the brain is isolated by the placenta you
could then even lyse and replace a middle-aged body.
What do you think of the idea? Has anyone ever articulated something
like this before?
[snip]
Though only peripherally related to nanotech, this item by Thomas
Donaldson, which originally appeared in the August 1988 issue of Analog
science fiction/science fact, is close to what you describe:
http://www.alcor.org/Library/html/24thcenturymedicine.html
--
You know what to remove, to reply.... |
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| Chris Phoenix |
| Posted: Fri Nov 14, 2003 12:02 am |
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sanman wrote:
Quote: And in my opinion, replacement or
replenishment of genetic material is fundamental to extending the
lifespand of flesh-and-blood creatures. Because we know that not only
is flesh eroded by environmental factors, but also the integrity of
its genetic information is degraded over time by the very act of
genetic replication (ie. a photocopy of a photocopy of a photocopy of
a photocopy looks fuzzy compared to the original)
Germline cells are the result of lots and lots of genetic replication,
but the next generation absolutely depends on their being accurate.
It's possible, of course, that more energy is spent in germline cells to
correct DNA copying errors, and non-germline cells are more susceptible
to copying errors. But this implies that this cellular machinery could
be turned up in other cells, saving them from further damage. And
anyway I don't think it's correct. Feel free to disprove me with a
reference.
Aubrey de Grey has done a lot of study of aging, and has found only
seven causes. http://www.gen.cam.ac.uk/sens/ I don't think any of them
involve fuzzy copying. Some of them involve genetic damage, of course,
and telomeres are mentioned, but I don't think either of these is what
you were referring to.
Chris
--
Chris Phoenix cphoenix@CRNano.org
Director of Research
Center for Responsible Nanotechnology http://CRNano.org |
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| Joann Evans |
| Posted: Fri Nov 14, 2003 9:32 am |
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sanman wrote:
[snip}
Quote: If a womb and placenta can sustain a fetus, could something similar be
artificially engineered to sustain an entire human brain? Plausible,
or not? Comments?
See also this from the Foresight Institute's Nanpmedicine pages:
http://www.foresight.org/Nanomedicine/Gallery/Captions/Image107.html
--
You know what to remove, to reply.... |
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| Leonid Gavrilov |
| Posted: Tue Nov 18, 2003 1:05 am |
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[ Moderator's note: To reiterate co-moderator Gordon's request, please try to
bring the focus back to nanotech's role in this or perhaps continue the
discussion on a more appropriate biology newsgroup. Thanks! -JimL ]
manofsan@yahoo.com (sanman) wrote in message
news:<bp9kmo0206q@enews3.newsguy.com>...
Quote: In my recollection, the haploid gamete cells are created early on, and
don't have to undergo much somatic type replication until they are
used in the act of conception. So your sperm cells have their original
genetic integrity, unlike the rest of the cells in your body, which
have multiplied many times on your way to adulthood.
***
As for male sperm cells, they accumulate a lot of mutations with
human age, see for example published review at:
"Human longevity and parental age at conception"
In: Sex and Longevity, Berlin, Heidelberg: Springer-Verlag, 2000,
7-31.
http://longevity-science.org/Parental_Age_2000.pdf
Kind regards,
-- Leonid Gavrilov
Author of the book "The Biology of Life Span"
http://longevity-science.org/index.html#Book |
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