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Re: Son of ALARA!
Hi Steve,
Thanks for your inquiry. See below.
Steve Costigan wrote:
>
> Jim Muckerheide wrote:
>
> "Consider that radiation causes "local" hits (single cell as
> you describe, but more often multi-cell) and the signal transduction
> stimulates responses that generally improve anti-oxidant and related
> protective capabilities; enzymes, proteins, gene expression, etc.; and
> apoptosis, etc. that improve general molecular, cellular, and tissue
> responses, ....."
>
> and:
>
> "Consider that there are Millions of times more ssb's and dsb's
> from normal oxidative metabolism (plus heat, stress, etc.) than from
> the normal range of background radiation"
>
> Can someone out there provide references of scientific studies that
> demonstrate that ionizing radiation induces the biological responses
> mentioned above that could mitigate against radiation damage? Also, I was
> not aware that the rate of double stranded breaks was that high under
> normal conditions, is there a reference to support this? Thanks.
>
> ***********************************************************************
> Steve Costigan, CHP
> ESH-1 Health Physics Operations
> Los Alamos National Laboratory
> MS G749
> Los Alamos, NM 87545 phone: 505-665-9435
> fax: 505-665-6678 e-mail: costigan@lanl.gov
> ************************************************************************
Re dsb's, recall the ref Dan Strom identified from Science in the last few
weeks that showed a free electron being captured on a DNA strand and having an
interaction that caused dsb's! They are a small fraction, a few percent, of
the 10s of Millions of ssb's per year PER CELL! But that's a lot! :-)
In today's current lit search
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10757755&dopt=Abstract
I just happened to see today the following "current example" that is
descriptive though specifically for UVB, but applicable. I have NOT read this
paper, do not know the actual equivalent doses, and encourage anyone
interested to see if this fully represents the responses that are routinely
seen in biology that contradict the LNT and the idea that DNA damage is
related to carcinogenesis, vs. damage control, and that LDR enhances damage
control while higher doses suppress DNA/cellular damage control. (To be sure
I'm accurately incorporating all the abstract, you can find it at: :-)
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10657961&dopt=Abstract
)
(I'll add a few other refs for gamma and x-ray responses following this, going
back just a few years to show this isn't "new" - and can go back further to
show this REALLY isn't new. See, e.g., the Calabrese and Baldwin papers
recently sent to the list.):
Liebler DC, Burr JA; Carcinogenesis 2000 Feb;21(2):221-5; "Effects of UV light
and tumor promoters on endogenous vitamin E status in mouse skin."
Department of Pharmacology and Toxicology and Southwest Environmental Health
Sciences Center, College of Pharmacy, The University of Arizona, Tucson, AZ
85721-0207, USA. liebler@pharmacy.arizona.edu
ABSTRACT
"Recent reports indicate that both orally administered and topically applied
alpha-tocopherol (vitamin E, TH) prevent UVB-induced skin carcinogenesis in
mice."
[NOTE: E, TH prevents UVB-induced skin cancer.]
"Because UVB exposure causes the formation of oxidants associated with tumor
promotion, epidermal TH status may be an important determinant of
susceptibility to photocarcinogenesis."
[NOTE: rad causes oxidants that promote tumors - not "DNA damage that causes
tumors"]
"To test this hypothesis, we studied the status of epidermal TH in C3H mice
following exposure to single and repeated UVB exposures at doses typical of
chronic photocarcinogenesis protocols."
[NOTE: doses? "typical of chronic." Is this "low-dose" enough? Check
biological response:]
"Exposure of mice to a single 13 kJ/m(2) dose over 60 min resulted in no
acute depletion of epidermal TH and a modest increase in TH within 6-12 h."
[NOTE: INCREASE in TH - in 6-12 hr. Recall: TH _prevents_ UVB-induced skin
cancer.]
"Daily exposure to 6.5 kJ/m(2) over 30 min resulted in a gradual increase in
epidermal TH, which reached 5-fold after five daily exposures."
[NOTE: stimulates a 5-fold increase in TH]
"The increase in epidermal TH was accompanied by an increase in the TH
oxidation products alpha-tocopherolquinone (TQ) and
alpha-tocopherolhydroquinone (THQ). We also studied the effect of the
prooxidant chemical tumor promoter benzoyl peroxide and the prooxidant azo
initiators azobis(amidinopropane HCl) and azobis(2, 4-dimethylvaleronitrile).
Topical application of these prooxidant chemicals acutely oxidized epidermal
TH to TQ and THQ. Topical treatments with the phorbol ester tumor promoter
12-O-tetradecanoylphorbol-13-acetate (TPA) increased epidermal TH levels
without producing a significant accumulation of TH oxidation products. The
results indicate that UVB and tumor promoting chemicals all exert
qualitatively different effects on epidermal TH status and that UVB and TPA
trigger an adaptive response involving epidermal TH accumulation."
[NOTE: What is the trade-off in tumor promotion vs. tumor suppression?]
>>>>>
For some sources that are more explicit about the biological response re the
"net benefit" of LDR:
You may recall the new paper by Yamaoka et al. sent to radsafe a few weeks ago
about enhanced recovery from liver damage using 50 cGy irradiation, with data
on various biological function indicators. An earlier paper by Nomura and
Yamaoka with separate but equivalent results is at:
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10641727&dopt=Abstract
There are voluminous sources that report on LDR beneficial effects in
infection and wound healing. In 1896 Shrader pub'd in "Electrical Engineering"
a response to JJ Thompson's statement that Roentgen's rays would not be
bactericidal an experiment in which Guinea pigs were injected with diphtheria
bacillus sufficient to kill all unirradiated animals in 24 hours, while the
irradiated animals largely survived.
More recently, in 1991, Berk and Hodes reviewed the evidence on infections and
stated in the abstract:
http://cnts.wpi.edu/RSH/Data_Docs/1-2/3/3/Rev%202%201233list.html
[All full refs in the limited materials on the RSH site are at:
http://cnts.wpi.edu/rsh/Data_Docs/references98.html]
Some general sources from our site include:
Liu, China, HPJ May 1987 (Report on the Oakland "Hormesis Special Issue"):
http://cnts.wpi.edu/rsh/Data_Docs/1-5/157li87.html
Liu, 1994 on immune enhancement signal transduction in T-lymphocytes:
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=7848556&form=6&db=m&Dopt=b
and in 1996 on thymocyte apoptosis:
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=8946023&form=6&db=m&Dopt=b
Dr. Matsubara is now on the Japan equivalent of the NRC. She was at, and
soundly ignored, at the December Airlie Conference (as were all the few
knowledgeable biologists that questioned the dishonest conference run by
ICRP/NCRP/IAEA):
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10669556&dopt=Abstract
Luckey 1991, Radiation Hormesis:
http://cnts.wpi.edu/rsh/Data_Docs/1-5/153lu91.html
and 1996 re immune response:
http://cnts.wpi.edu/rsh/Data_Docs/1-5/154lu96.html
These are of course extremely limited materials with respect to Dr. Luckey's
documentation of more than 2500 refs and the fundamental biology that is not
considered by the "biophysics" approach of the rad protection establishment.
See, e.g., Alexander Kuzin, Acad of Sci, Russia:
http://cnts.wpi.edu/rsh/Data_Docs/1-4/149ku93.html
Kesavan, India, at the 1997 IAEA Seville Conference:
http://cnts.wpi.edu/rsh/Data_Docs/1-5/154lu96.html
Back to 1987, as part of the basis to successfully apply LDR to people to cure
cancer (recently including curing himself of advanced colon cancer in 1998),
Dr. Kiyohiko Sakamoto (recently met with us in Ottawa and in Tokyo, and when
he was already ill, at ANS in 1996 and SNM in 1997) at the Tohoku U. School of
Medicine at Sendai:
http://cnts.wpi.edu/rsh/Data_Docs/1-4/1410sa87.html
and
http://cnts.wpi.edu/rsh/Data_Docs/1-4/1411mi87.html
See his early human cases (in a 1996 presentation) at:
http://cnts.wpi.edu/rsh/Data_Docs/1-2/3/3/12332sa96.html
and similar results with human case data by Dr. Takai (1991 paper):
http://cnts.wpi.edu/rsh/Data_Docs/1-2/3/3/12332sa96.html
See also work on the dramatic combined effects of 15 cGy with OK-432 in mice
to knock out squamous cell carcinoma:
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9436245&dopt=Abstract