RE: radon - DNA damage - yeast - input from the biologists

>irrelevant chromosome aberrations, which can indeed be 'markers' of

radiation exposure, but are of no real significance to health effects

since the issue of producing cancer is DNA repair/mis-repair, not the

dead ends of permanently damaged chromosomes :-)

---------

I cannot agree with this - the cancer cells start somewhere. Those which do

not die due apoptosis and other phenomena undergo a successively increasing

amount of lost alleles, point mutations, DNA frameshifts, and messed up

karyotypes (disturbed spindle functions) - often it begins with a

duplication of all chromosomes (to make them tetraploid) - then followed by

some lost chromosomes resulting in hypotetraploid cells.

To make this more clear: Most cells can remain functional in many respects

while they are having translocations etc. The critical events may occur when

you get breakpoints in promotor regions of DNA or destroy the function of

genes regulating the cell cycle, the integrity of DNA (repair and structure)

or signaling systems (from membrane level to the nucleus and promotors).

Specific translocations are wellknown for the Philadelphia chromosome,

Burkitt's lymphoma (G. Klein et al.) and other contexts. For a lost Rb

function - see the papers by Nordenskiold et al. (Karolinska Institutet). In

addition, you should study DNA rearrangements in tumors as they have been

described in leading journals like Cancer Research.

I don't know if you mean to imply something about biologists or

technologists (good or bad?) - I belong to both categories. The findings

(messed up DNA in tumor cells) are all there - lots of them - if it is a

math person or biologist who points at them should be quite irrelevant.

Bjorn Cedervall bcradsafers@hotmail.com

http://www.geocities.com/bjorn_cedervall/

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