[ RadSafe ] Any information on the credibility of the InternationalJournal for Health Services!!
alstonchris at netscape.net
alstonchris at netscape.net
Thu Dec 22 12:56:58 CST 2011
Hi Guys
Seems to me that the fast and dirty way to take the measure of the quality of a journal is to ask what the sponsoring institution is, and who is on the board of reviewing editors. E.g, Science is published by the AAAS, and the roster of reviewing editors reads like a short list of the most distinguished scientists in the world.
Happy Holidays
cja
-----Original Message-----
From: Brennan, Mike (DOH) (DOH) <Mike.Brennan at DOH.WA.GOV>
To: parthasarathy k s <ksparth at yahoo.co.uk>; The International Radiation Protection (Health Physics) Mailing List <radsafe at health.phys.iit.edu>
Sent: Thu, Dec 22, 2011 12:56 pm
Subject: Re: [ RadSafe ] Any information on the credibility of the InternationalJournal for Health Services!!
Hi, Parthasarathy.
I am not familiar with the Journal, but a quick look at the web page shows they
are highlighting a "study" by Mangano, who is a cherry-picker from way back. If
I were on the board of a journal, I would be inclined to dismiss his work out of
hand, so conversely I would have to be suspect of any journal that would publish
his work.
-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu]
On Behalf Of parthasarathy k s
Sent: Thursday, December 22, 2011 12:01 AM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: [ RadSafe ] Any information on the credibility of the
InternationalJournal for Health Services!!
Mike,
Can you enlighten me on the Journal called " International Journal of Health
Services". It publishes papers which appears to be bogus such as the the one
the list members talked about recently. It highlighted increased deaths in USA
post Fukushima. In 2004, the journal published results of "studies" in the high
background radiation areas of India. I know one of the authors of the paper. He
is a well-known anti nuclear activists
Any information on this journal!!
Regards
Parthasarathy
________________________________
From: "Brennan, Mike (DOH)" <Mike.Brennan at DOH.WA.GOV>
To: The International Radiation Protection (Health Physics) MailingList
<radsafe at health.phys.iit.edu>
Sent: Wednesday, 21 December 2011, 23:15
Subject: Re: [ RadSafe ] Berkeley Lab News Release: New Take on Impacts ofLow
Dose Radiation
Aside from the implications for LNT, I would like to point out that the
researcher were taking time-lapse images of things going on on DNA. How cool is
that?
-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu]
On Behalf Of ROY HERREN
Sent: Tuesday, December 20, 2011 11:33 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Berkeley Lab News Release: New Take on Impacts ofLow
Dose Radiation
For the full article please see
http://newscenter.lbl.gov/news-releases/2011/12/20/low-dose-radiation/
Roy Herren
________________________________
From: "Perle, Sandy" <sperle at mirion.com>
To: The International Radiation Protection (Health Physics) Mailing List
<radsafe at health.phys.iit.edu>
Sent: Tue, December 20, 2011 1:58:15 PM
Subject: [ RadSafe ] Berkeley Lab News Release: New Take on Impacts of Low Dose
Radiation
Very interesting study conducted at Lawrence Berkley National Laboratory
Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley
National Laboratory (Berkeley Lab), through a combination of time-lapse live
imaging and mathematical modeling of a special line of human breast cells, have
found evidence to suggest that for low dose levels of ionizing radiation, cancer
risks may not be directly proportional to dose. This contradicts the standard
model for predicting biological damage from ionizing radiation - the
linear-no-threshold hypothesis or LNT - which holds that risk is directly
proportional to dose at all levels of irradiation.
"Our data show that at lower doses of ionizing radiation, DNA repair mechanisms
work much better than at higher doses," says Mina Bissell, a world-renowned
breast cancer researcher with Berkeley Lab's Life Sciences Division. "This
non-linear DNA damage response casts doubt on the general assumption that any
amount of ionizing radiation is harmful and additive."
Bissell was part of a study led by Sylvain Costes, a biophysicist also with
Berkeley Lab's Life Sciences Division, in which DNA damage response to low dose
radiation was characterized simultaneously across both time and dose levels.
This was done by measuring the number of RIF, for "radiation induced foci,"
which are aggregations of proteins that repair double strand breaks, meaning the
DNA double helix is completely severed.
"We hypothesize that contrary to what has long been thought, double strand
breaks are not static entities but will rapidly cluster into preferred regions
of the nucleus we call DNA repair centers as radiation exposure increases," says
Costes. "As a result of this clustering, a single RIF may reflect a center where
multiple double strand breaks are rejoined. Such multiple repair activity
increases the risks of broken DNA strands being incorrectly rejoined and that
can lead to cancer."
Costes and Bissell have published the results of their study in the Proceedings
of the National Academy of Sciences in a paper titled "Evidence for formation of
DNA repair centers and dose-response nonlinearity in human cells." Also
co-authoring the paper were Teresa Neumaier, Joel Swenson, Christopher Pham,
Aris Polyzos, Alvin Lo, PoAn Yang, Jane Dyball, Aroumougame Asaithamby, David
Chen and Stefan Thalhammer.
The authors believe their study to be the first to report the clustering of DNA
double strand breaks and the formation of DNA repair centers in human cells. The
movement of the double strand breaks across relatively large distances of up to
two microns led to more intensely active but fewer RIF. For example, 15 RIF per
gray (Gy) were observed after exposure to two Gy of radiation, compared to
approximately 64 RIF/Gy after exposure to 0.1Gy. One Gy equals one joule of
ionizing radiation energy absorbed per kilogram of human tissue. A typical
mammogram exposes a patient to about 0.01Gy.
Corresponding author Costes says the DNA repair centers may be a logical product
of evolution.
"Humans evolved in an environment with very low levels of ionizing radiation,
which makes it unlikely that a cell would suffer more than one double strand
break at any given time," he says. "A DNA repair center would seem to be an
optimal way to deal with such sparse damage. It is like taking a broken car to a
garage where all the equipment for repairs is available rather than to a random
location with limited resources."
However, when cells are exposed to ionizing radiation doses large enough to
cause multiple double strand breaks at once, DNA repair centers become
overwhelmed and the number of incorrect rejoinings of double strand breaks
increases.
"It is the same as when dozens of broken cars are brought to the same garage at
once, the quality of repair is likely to suffer," Costes says.
The link between exposure to ionizing radiation and DNA damage that can give
rise to cancerous cells is well-established. However, the standards for cancer
risks have been based on data collected from survivors of the atomic bomb blasts
in Japan during World War II. The LNT model was developed to extrapolate low
dose cancer risk from high dose exposure because changes in cancer incidence
following low dose irradiation are too small to be measurable. Extrapolation was
done on a linear scale in accordance with certain assumptions and the laws of
physics.
"Assuming that the human genome is a target of constant size, physics predicts
DNA damage response will be proportional to dose leading to a linear scale,"
Costes explains. "Epidemiological data from the survivors of the atomic bombs
was found to be in agreement with this hypothesis and showed that cancer
incidence increases with an increase in ionizing radiation dose above 0.1 Gy.
Below such dose, the picture is not clear."
Previous studies failed to detect the clustering of double break strands and the
formation of DNA repair centers because they were based on single-time or
single-dose measurements of RIF at a discrete time after the initial exposure to
ionizing radiation. This yields a net number of RIF that does not account for
RIF that have not yet appeared or RIF that have already made repairs and
disappeared. The time-lapse imaging used by Costes, Bissell and their co-authors
showed that RIF formation continues to occur well beyond the initial radiation
exposure and after earlier repair issues have been resolved. Time-lapse imaging
also indicates that double strand break clustering takes place before any RIF
are formed.
"We hypothesize that double strand break clustering occurs rapidly after
exposure to ionizing radiation and that RIF formation reflects the repair
machinery put in place around a single cluster of double strand breaks," Costes
says. "Our results provide a more accurate model of RIF dose response, and
underscore fundamental concerns about static image data analysis in the dynamic
environment of the living cell."
Previous studies also mostly involved fibroblast cells whereas Costes, Bissell
and their colleagues examined epithelial cells, specifically an immortalized
human breast cell line known as MCF10A, which has a much higher background of
RIF than fibroblasts, even without ionizing irradiation. To compensate for this
higher background, Costes developed a mathematical method that enables
background to be corrected for on a per- nucleus basis in unirradiated cells.
Still the use of a special line of immortalized breast cells is an issue that
Costes and his colleagues plan to address.
"We are now looking at primary breast epithelial cells that have been removed
from healthy donors to determine if our results are repeated beyond just a
single cell line and under more realistic physiological conditions," Costes
says. "We'd also like to know if our findings hold true for fibroblasts as well
as epithelial cells. Also, we'd like to know if double strand break clustering
is the result of a random coalescence or if there is an active transport
mechanism that moves these double strand breaks towards pre-existing DNA repair
centers."
Working in collaboration with Rafael Gomez-Sjoberg of Berkeley Lab's Engineering
Division, Costes and his group are also developing a special microfluidics
lab-on-a-chip device that is integrated into an X-ray microbeam. The goal is to
provide a means by which cells can be kept in a controlled microenvironment
while being irradiated with multiple doses. This microfluidic array will be used
to characterize DNA damage response in breast and blood cells collected from
human donors.
"By characterizing DNA damage response in cells from many different human
donors," Costes says, "we should be able to determine the variation across
humans and gain a better understanding of how sensitivity to DNA damage from
ionizing radiation might vary from individual to individual."
This research was supported by the DOE Office of Science.
-----------------------------------
Sander C. Perle
President
Mirion Technologies
Dosimetry Services Division
2652 McGaw Avenue
Irvine, CA 92614
+1 (949) 296-2306 (Office)
+1 (949) 296-1130 (Fax)
Mirion Technologies: http://www.mirion.com/
”Protecting people, property and the environment”
_______________________________________________
You are currently subscribed to the RadSafe mailing list
Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu
_______________________________________________
You are currently subscribed to the RadSafe mailing list
Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at: http://health.phys.iit.edu/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu
_______________________________________________
You are currently subscribed to the RadSafe mailing list
Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at: http://health.phys.iit.edu/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu
_______________________________________________
You are currently subscribed to the RadSafe mailing list
Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at: http://health.phys.iit.edu/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu
_______________________________________________
You are currently subscribed to the RadSafe mailing list
Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at: http://health.phys.iit.edu/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu
More information about the RadSafe
mailing list