X-Message-Number: 8901
From:  (Ken Stone)
Subject: re: Why use humans for research instead of animals?
Date: Fri, 05 Dec 1997 20:34:31 GMT
References: <>

>From: Stephen Bogner <>
>
>I may have missed the premise of the "Donate Bodies for Research" thread. 
> Why are dead and dying human subjects preferred over animal models for 
>research?  Surely the state of research is not so far advanced that the 
>subtle difference between an animal model and a human model has become an 
>issue.

I think there are some big questions where those differences 
might not be at all subtle.  I know there have been a few cranial 
burr-hole tests which have given some hope, but I don't think anyone 
really knows if current suspension protocols are adequately perfusing 
the brain.  Furthermore, because cryoprotectants are themselves fairly 
toxic at the temperatures where they aren't too viscous to be used, 
there's a very tricky balance to be maintained: if the perfusion 
concentrations are inadequate, the patient's brain will suffer
mechanical freeze damage that is likely to be irreversible.  (Sorry, 
I'm not a big believer in capital 'N'-style Nanotechnology.)  And then
even if the cryoprotectant perfusion *is* effective, their brains 
may already be destroyed chemically before the patients ever rech
LN2 temps.  Great options, huh?  Maybe some day, our friends
in the future will be able to fix such damage.  But maybe not.

Some schemes are in place which try to walk the "not too much"/"not
too little" line, but without being able to carefully examine the results 
of real suspensions on real people, we can only speculate about how
effective they really are, and hope.  (If that's good enough for you, 
so be it, but with so much Faith, you might be better off considering 
options other than cryonics anyway.)

As to your question about animal models:  Human brains are quite a 
bit larger and rather differently structured than most other members 
of the animal kingdom.  We can expect that the vasculature and 
perfusion requirements will be noticeably different as well. For 
those creatures which MIGHT not be so different (e.g. dolphins,
chimpanzees, great apes), you're going to have a hard time convincing 
me that slaughtering them (with unknown applicability) while 
simply letting unfunded people die is somehow preferential to a
scheme which gives at least some hope to THOSE PEOPLE WHO WANT IT.

And who knows? Perhaps researchers might even be able to devise 
techniques that will allow them to very cleanly dissect and 
examine brain structures while preserving them at or near LN2 
temp.  Then they could return the pieces to storage after 
examination, knowing that even sliced-up brains might someday
be repaired.

Ken Stone


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