Re: LNT and Bystander Effect

[Emil Murat <kerrembaev@YAHOO.COM>]

Greetings,





You wrote:



>>>

At still lower doses, 

bystander effects may dominate the overall response,

possibly leading to an 

underestimation of low-dose risks extrapolated from

intermediate doses, 

where direct effects dominate

>>





Congratulations to the researches!

Good Job!

I think it is a great experiment and a great model

used to explain their own data! 



However,



1.1 I can agree with the statement: "If your

neighbor's dog got hit by the truck, it will effect on

neighborhood's moral spirit".



1.2 But I can not agree that all neighbors eventually

will die because of it?



Let's, Y'all not mix oranges with apples.



Who had proved that there is a "low-dose risks"?.

Risk of what???

Be more healthy?

May be....

Some of us think it is the case, 

others think inversevely.



What do I think? if I ever think..... 

If I ever stop thinking........



In my present life, I have only one head in my

disposal and I have other important things to think

about.



But,



I do  not  think  about things like 

"Will I get hit by the truck or not"?  

Or 

" Will the boat, which is carrying 207 Uzbek workers

from South to North Korea, get hit by the submarine

because the sub's captain was underwater for three

month and he is so anxious to see his wife, that he

can not see a little boat above the sub.



Although, here is something, I thought about when I

read the article:





2.1 YES. Bystander cells may respond to damage of the

target cell.



2.2 YES. Bystander cells response/effect can be higher

then target cell response/effect.



(For those, who can not understand the analogy

language, PLEASE, do read below this point.)



2.3 NO.  Who said that dog's owner MUST die if his dog

got hit by the truck?



2.4  0. I am NOT even asking about the owner neighbors

life expectancy vs. Dog's misfortune.



2.5 NO. Some neighbors may be happy that dog has died,

if the dog was too angry.





If Yes = (-No)



2YES + 2NO + 0 = 0. 



The result is still "ZERO".



Capice?



No offense, just discussion.



Emil.









The original message:



>>>>>

LNT and Bystander Effect

Radiat Res 2001 Mar;155(3):402-8 Related Articles,

Books

The bystander effect in radiation oncogenesis: II. A

quantitative model.

Brenner DJ, Little JB, Sachs RK

Center for Radiological Research, Columbia University,

New York, New York 

10032, USA.



There is strong evidence that biological response to 

ionizing radiation has a contribution from

unirradiated "bystander" cells 

that respond to signals emitted by irradiated cells.

We discuss here an 

approach incorporating a radiobiological bystander

response, superimposed on a 

direct response due to direct energy deposition in

cell nuclei. A 

quantitative model based on this 

approach is described for alpha-particle-induced in

vitro oncogenic 

transformation. The model postulates that the

oncogenic bystander response 

is a binary "all or nothing" phenomenon in a small

sensitive subpopulation 

of cells, and that cells from this sensitive

subpopulation are also very 

sensitive to direct hits from alpha particles,

generally resulting in a 

directly hit sensitive cell being inactivated. The

model is applied to 

recent data on in vitro oncogenic transformation

produced by broad-beam or 

microbeam alpha-particle irradiation. Two parameters

are used in analyzing 

the data for transformation frequency. The analysis

suggests that, at least 

for alpha-particle-induced oncogenic transformation,

bystander effects are 

important only at small doses-here below about 0.2 Gy.

At still lower doses, 

bystander effects may dominate the overall response,

possibly leading to an 

underestimation of low-dose risks extrapolated from

intermediate doses, 

where direct effects dominate.

>>>>















__________________________________________________

Do You Yahoo!?

Get email at your own domain with Yahoo! Mail. 

http://personal.mail.yahoo.com/

************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.



------------------------------