RE: NCRP 136 / Immunology, DNA repair, cancer...

["Jacobus, John (OD/ORS)" <jacobusj@ors.od.nih.gov>]

Gary,

Although Les did not provide a link, here it is.

http://www.mayohealth.org/findinformation/conditioncenters/invoke.cfm?object

id=03E3E720-7C27-43C0-9DB3EBB58E7843CE

It is always useful to go to the source.  



The big question is if the immune system is doing this marvelous job, why do

cancers occur.  One possibility is that the immune system is damaged.

Another is that the immune system does not recognized the cancer cells are

tumors.  It is unclear to me if simply "stimulating" the immune system with

radiation really increases the immune system to attack the cancer.  If so,

why did it not do so before?  Could the radiation, in the process of

damaging cells, enhance the scavenging ability of the immune system, but in

a not specific, i.e., anti-cancer cell, way?



The purpose of Mossman's article is that hormesis cannot be used for

regulatory purposes.  It is defined as a positive effect, but regulations

are based on limiting detrimental effects, so what place should it place in

the laws?  The purpose was not to defend the LNT, but to state that based on

the evidence it is the most reasonable theory.  And it is a theory, but

seems to fit the data.  I will not reiterate some of the material in the

article, but it is clear to me that it is difficult to demonstrate either a

harmful or beneficial effect at low doses of radiation.  In many cases, the

data from several studies overlaps.  If you can read parts of NCRP 136, you

can see a lot of this.



-- John 



-----Original Message-----

From: Gary Isenhower [mailto:garyi@BCM.TMC.EDU]

Sent: Wednesday, October 24, 2001 11:37 AM

Cc: radsafe@list.vanderbilt.edu

Subject: Re: NCRP 136 / Immunology, DNA repair, cancer...





John,



I have been following this thread with interest.  Your response to Les

does not seem to address the key statements in the quote from the Mayo

Clinic.  Are you trying to say they are wrong, misquoted, or

misunderstood?



I also read the Mossman article some time back.  He said many things,

but did not, IMHO, address the key issue of evidence against LNT. 

Please don't assume that I am heavily for or against LNT, but if the

proponents of either side are unable to clearly and logically refute

opposing statements and articulate their own, then they don't have much

of a case.



"Jacobus, John (OD/ORS)" wrote:

> 

> Les,

> I think you are a little confused as to how cancers develop, and what role

> the immune system and cellular components play in DNA repair.  If cancer

> initiation, development and propagation were as simple as you think, we

> would have found cures years ago.

> 

> I would recommend you read the Mossman article, and let me know what you

> think.

> 



-- 

    _______________________________________________



	Gary Isenhower

	713-798-8353

	garyi@bcm.tmc.edu

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