In article <3lqehc$l3b at mserv1.dl.ac.uk>, <W.G.VAN.DOORN at ATO.AGRO.NL> wrote:
> Andy - part of my last message was not kept, for some reason. I
began >with
> a paragraph in which I said I appreciated your definitions, which
> were quoted below. I accept that biologists working on cell division
> call cell lines that do not stop replicating to be 'immortal'. I am
> also a biologist, and would rather define 'immortal' (if I would use the
> word at all) for an individual cell or an individual polycellular orga-
> nism. The word immortal, however, is not very exact as it is not easy to
> prove.
>> Thank you for explaining the terminology of biologists working on cell
> lines. It clearly helps the discussion.
>
Sorry about the confusion with the last message! I think your last point
is well taken with respect to dealing with stem cells in vivo. As Potten
and Loeffler pointed out in an excellent review on stem cells a few years
back, there are great difficulties in trying to interact experimentally
with stem cells, as you may change their behaviour in the process. They
referred to this as Heisenberg's Uncertainty Priciple operating in a
biological context, which I think is a very interesting idea!
Best wishes,
Andy
--
Andy Groves
Division of Biology, 216-76
California Institute of Technology
