On Thu, 15 Jan 1998  Joao Pedro <jpnitya@mail.esoterica.pt> Wrote:
         
        >certain cells that do not divide -- post-mitotic cells like neurons         
        >might also age. 
True. Perhaps neurons age because the support they receive from other cells 
that do divide degrades, or perhaps telomere shorting is not the only clock  
in every cell, but if one clock can be found so can another.
     
Damien Broderick:
        >My guess is that its [telomerase] production is inactivated in         
        >somatic cells as a general prophylaxis  against cancer. Immortal         
        >tumors do, indeed, switch telomerase production back on.
              
Geron also has a patent on a telomerase inhibitor. Except for sperm and eggs 
most cells don't produce telomerase (some cells lining the stomach and 
intestine produce a little, but not enough to become immortal) so this 
inhibitor shouldn't have many side effects, but all known cancers produce 
lots of it. Geron has a sensitive method for detecting telomerase and hopes to 
use it to diagnose cancer. The company also wants to develop its telomerase 
inhibitor into a cancer treatment, if it works it would turn our worst enemy 
into a friend, a fast growing cancer would die of old age.
On Tuesday when Geron made the announcement that they had made human cells 
immortal its stock jumped up by 44%, does anybody have an opinion about Geron  
as an investment?
                                            John K Clark    johnkc@well.com
-----BEGIN PGP SIGNATURE-----
Version: 2.6.i
iQCzAgUBNL5jHn03wfSpid95AQEB8gTuKpMgo3CeY90Ds6npyTOKbUik2a8EWUrs
EmxfAOGk4XPQYRw/NkGeMCwO30BpdF4IqvKGWiozWaThbijNGpeU7CSoeyv1Jpgr
k30iWSwK+gljU4tZ7BBLRhS755w9Xqr7q4IpXqVPZK3USrFlWFvdtXB0A9rvk7Wj
olJDFys3ROLyMrH8OLD/b5f4cMwwLOZ6k0xiGG8zDK7CV4UcA9c=
=SGsp
-----END PGP SIGNATURE-----