[ RadSafe ] Danger of ADJACENT HIGH-Dose Radiation

HOWARD.LONG at comcast.net HOWARD.LONG at comcast.net
Wed Aug 20 11:35:42 CDT 2008

So, "high dose radiation - 12,000 times - chest x-ray" affects adjacent tissue?
Would other severe injury, like crushed arm, affect the rest of the body? Of course!

Why the surprise?

Why the false headline that it  "Hints at Dangers of Low Dose Radiation"?

Hormesis, low dose good where high dose bad, must be taught.  
We must correct this disinformation by fearmongers 
to dismantle over-regulation and liberate nuclear power.

Howard Long

-------------- Original message -------------- 
From: ROY HERREN <royherren2005 at yahoo.com> 

> http://sciencenow.sciencemag.org/cgi/content/full/2008/818/3 
> Bystander Effect" Hints at Dangers of Low-Dose Radiation 
> By Jocelyn Kaiser 
> ScienceNOW Daily News 
> 18 August 2008That lead apron you wear during a dental x-ray is supposed to 
> protect the rest of you from radiation. But it may not work very well, according 
> to a new study. When cancer-prone mice were placed in lead containers and 
> irradiated on just the lower half of their bodies, they developed brain tumors. 
> The results suggest that radiation could be riskier than scientists thought. 
> The study builds on a surprising effect, first observed 16 years ago. When cells 
> in culture are exposed to ionizing radiation, even those not directly hit 
> sustain damage to chromosomes. Apparently, the irradiated cells pass on a 
> distress signal or emit some chemical that breaks the DNA of neighboring cells 
> (ScienceNOW, 7 September 2005). Although this "bystander effect" has been 
> observed in tissue culture and recently in living animals, no experiments have 
> yet linked it to the main reason for concern: Bystander effects might trigger 
> cancer. Some scientists even suspect the opposite--that the bystander responses 
> could protect against the disease by killing damaged cells. 
> Now it seems that the cancer risk is real. Radiation oncologist Anna Saran at 
> the Italian National Agency for New Technologies, Energy and the Environment in 
> Rome and colleagues studied mice with a mutation in a gene called Patched that 
> makes them susceptible to brain tumors early in life. They placed newborn mice 
> in lead shields that protected their heads and upper bodies, then zapped them 
> with high-dose x-rays, or about 12,000 times the dose of a dental or chest 
> x-ray. The scientists found that the cerebellums of these animals had higher 
> than normal amounts of DNA damage and apoptosis, or programmed cell death. By 40 
> weeks of age, 39% of the shielded mice had developed brain tumors. That's a lot 
> considering that the rate was 62% in Patched mice that were irradiated all over, 
> including their heads. Patched mice that weren't irradiated did not develop 
> brain cancer. 
> When the team injected the shielded mice with a chemical that blocks 
> cell-to-cell communication before irradiating them, they detected no DNA breaks 
> and the amount of apoptosis decreased more than threefold. Even though the 
> irradiated tissues are far away from the brain, they are connected by neurons 
> that could be passing on bystander signals, Saran says. The results appear 
> online this week in the Proceedings of the National Academy of Sciences. 
> "This is a milestone paper," says Columbia University radiation physicist David 
> Brenner. He suggests that current estimates of cancer risk from low doses of 
> radiation--say, from naturally occurring radon and diagnostic tests--may 
> underestimate the danger by failing to take into account bystander effects. To 
> learn more, however, the mouse work should be repeated with lower doses of 
> radiation, Saran says. 
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