Re: Hormesis and homeopathy

["Bjorn Cedervall" <bcradsafers@hotmail.com>]

>Some of the doses I have
>heard expressed on the Listserv as LDR are fairly significant.

For work will cell lines (cell survival, DNA damage etc), anything below 5 
Gy is often considered "low dose". For instance, the slope change in 
survival curves that some cell lines exhibit occurs at doses below 2 Gy. An 
example (there are others) is the colorectal cell line HT29 where the 
survival slope is very steep up to a dose of about 1 Gy and then levels off 
somewhat up to about 2 Gy. At doses above 2 Gy the usual shoulder is seen. 
It seems like some phenomenon is triggering a protection mechanism (this 
could be on the thiol-OH level - that is physical and organic chemistry). If 
this also is relevant for the formation of chromosomal aberrations it may 
indicate a higher relative risk at lower doses _for this particular cell 
line_. Some of the relevant publications come from the Gray laboratory in 
London (prof. Mike Joiner and others). Dr. Malaise (France) and Dr. Lambin 
(Belgium, publications around 1993) have also been involved in this. The 
technique for studying clonability etc at the Gray laboratory is excellent - 
I have seen their microscopic equipment - highly computerized with a good 
resolution. I wrote about it earlier here a couple of times - I don't think 
any Radsafer ever commented.

I think that any hormetic effects must be interpreted with care depending on 
endpoint and biological context. There must always be an underlying 
molecular mechanism that one can understand. In biology there is a trade off 
between what is good for the individual and what is good for the population 
or the next generation. For instance, individuals with a prolonged life will 
compete with their offspring for space and food. There is little humans can 
do about this for obvious reasons - it is not a nice idea - and certainly 
seldom even discussed from a theoretical aspect. Modern medicine, warm 
houses, clean clothes etc, are probably important destroyers of our genome. 
I would have died long ago because of the cold in this country - some of 
those wearing glasses would have got a tree branch in their eye and been 
taken by some wolves before they had a chance to reproduce and so on. Those 
with good vision would have lived longer to reproduce. This type of impact 
on our genome is probably quite large as compared to many other genetic 
risks we discuss. I did not write this to say that we should go back 300 
years in terms of medical care etc. Darwinism will always be there 
regardless of weather we like it or not - it just takes on new shapes - 
careless drivers are statistically deselected - the same goes for animals 
not watching out for cars on roads etc, etc. OK, I have better stop before I 
get totally off-topic or too provocative.

My personal ideas only,

Bjorn Cedervall   bcradsafers@hotmail.com
http://www.geocities.com/bjorn_cedervall/

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