But researcher says it could be a protective mechanism
By Janice Billingsley
HealthScoutNews Reporter

MONDAY, March 31 (HealthScoutNews) -- In a surprising finding, German
scientists have found that cells take a longer time to repair after
lower X-ray doses than after higher doses.

Radiation damages all cells, which then must repair themselves or die.
To date, scientists had thought that cell repair takes the same amount
of time no matter how much radiation the cell is exposed to, but a new
study discovered that cells exposed to lower doses of radiation -- the
amount similar to dental X-rays -- actually take from days to weeks
longer to repair than cell damage caused by higher levels of radiation,
which usually takes only a few hours to one day.

"The difference in repair between low and high doses of X-rays did
indeed surprise us," says study author Markus Lobrich, a professor of
radiation biology at the University of Saarland in Homburg, Germany. The
results appear in the March 31-April 4 Proceedings of the National
Academy of Sciences.

The doses given in most diagnostic tests, like dental X-rays,
mammograms, and CT scans, are considered low-dose, while the radiation
given to cancer patients is high-dose, Lobrich says. For example, a high
dose of radiation, aimed at killing cancer cells, is between 2 and 5 Gy.
(Each Gy is one joule of energy absorbed in a mass of 1 kilogram). In
cancer therapy, patients are treated with daily doses of about 2 Gy. In
contrast, a CT scan is only about 0.02 Gy, a mammogram about 0.01 Gy and
a dental exam usually less than 0.01 Gy.

Lobrich says the discrepancy between the rate of cell repair between
low- and high-dose radiation could mean an increase in cancer risk to
those who have low-dose radiation, or, conversely, it could be a
protective mechanism that actually decreases cancer risk.

When cells repair themselves from radiation, they aren't always returned
to their exact, original form, he says. In pasting back the broken parts
of a cell, called double-strand breaks (DSB), the cells are sometimes
changed into a slightly different cells, which are called mutations.
While uncommon, these mutations are associated with an increased risk of
cancer. When a large number of cells in one organ are damaged, as in
lung cancer radiation, for instance, the body has no choice but to
repair the DSBs, or the organ could fail, Lobrich says.

But with low-dose radiation, he says, only a few cells are damaged in a
given organ due to the small amount of radiation. The body could
basically decide it's better to let those few cells die and be replaced
by the division of existing healthy cells in the body than to repair the
DSB's and increase risk for a mutation. "I find this latter a more
intriguing idea," he says. "If you believe in the logic of nature, you
would expect the body to behave exactly this way, to refrain from repair
to avoid the risk of mutations."

"This study is very significant," says Timothy Jorgensen, an associate
professor of radiation medicine at Georgetown School of Medicine in
Washington, D.C. Jorgensen says that risk assessment of the effects of
radiation has been made from extrapolating how much damage and repair
occurs during high-dose radiation and assuming that cell damage and
repair follows the same pattern when radiation doses are lower. "But
this study suggests that the mechanism is different, and changes the way
we think about how radiation works," he adds.

The question, Lobrich says, will be the subject of further research.
In the meantime, Lobrich and other doctors say, don't stop having the
diagnostic X-rays you need. "I don't want people to get the idea that
X-rays are dangerous, because we are all exposed to low doses of X-rays,
and they are therapeutic, helping to prevent illness," says Richard B.
Setlow, a senior biophysicist at the Brookhaven National Laboratory.
Setlow brought the study to the attention of the National Academy of
Sciences, which publishes Proceedings.

Lobrich recommends having medically necessary X-rays, but exercising
some caution. "If there is a hereditary indication for an elevated
breast cancer risk, like having a mother and/or grandmother who had
breast cancer, have the mammography exams done and don't worry too much
about the radiation risk," he says. "But if the radiologist is about to
take another, or a third image of your chest because he didn't like the
quality of the first picture, stop and ask for a medical indication."
Lobrich adds that dental X-rays carry little risk because radiation is
not very likely to cause cancer in that part of the body.

For the study, scientists exposed human cell cultures in the laboratory
to X-ray levels similar to those in a standard dental exam. It was the
first time a study has been done of cell damage following low doses of
radiation, Setlow says. Previously, assessments of cell damage had been
estimated based on higher doses of radiation. Using a fluorescent
marker, the scientists noted the DSBs in the DNA of the cells following
the radiation and monitored them to see how long it took for the cells
to repair themselves after radiation.

"Usually DSBs are repaired within a few hours after radiation insult,"
Lobrich says, "but we observed that DSBs induced by very low doses
remained unrepaired for many days. And even two weeks after the
radiation, most of the induced DSBs were still present."

More information
The National Institutes of Health has a thorough explanation of
radiation and its effects. More information about radiation risks can be
found at the Environmental Protection Agency.

SOURCES: Richard B. Setlow, Ph.D., senior biophysicist, Brookhaven
National Laboratory, Upton, N.Y.; Markus Lobrich, Ph.D., professor of
radiation biology, Saarland University, Homburg, Germany; Timothy
Jorgensen, Ph.D., associate professor of radiation medicine, Georgetown
School of Medicine, Washington, D.C.; March 31-April 4, 2003,
Proceedings of the National Academy of Sciences
Copyright © 2003 ScoutNews, LLC. All rights reserved.

http://www.hon.ch/News/HSN/512500.html
http://www.med-rz.uni-sb.de/med_fak/biophys/ag-grill/research.htm
http://www.nlm.nih.gov/medlineplus/news/fullstory_12207.html
http://www.abc.net.au/science/news/health/HealthRepublish_820717.htm

Cellphones May Cause Alzheimers
12-Feb-2003

Talking on cellphones is the leading cause of crashes caused by driver
distraction, according to the California Highway Patrol. Maybe this is
because new evidence shows that cellphones may trigger the early onset
of Alzheimer's disease. Studies of rats in Sweden found that radiation
from mobile phones damages areas of the brain associated with learning,
memory and movement, but so far, no one has found conclusive evidence
that cellphones damage the human brain. It's a long-running debate
between people who want to talk and drive and other drivers who wish
they wouldn't, and people who say cellphones are safe to use and others
who think they're turning our brains into Swiss cheese. Leif Salford
experimented on rats aged between 12 and 26 weeks old, when their brains
are in the same stage of development as human teenagers. The rats were
exposed to two hours of radiation of the same kind emitted by mobile
phones. When their brains were examined under a microscope 50 days
later, they had many dead brain cells. "A rat's brain is very much the
same as a human's," says Salford. "We have good reason to believe that
what happens in rat's brains also happens in humans."

He also thinks cellphones could set off Alzheimer's disease in some
people. "What we are saying is those neurons that are already prone to
Alzheimer's disease may be stimulated earlier in life," he says.
"However, this theory is hypothetical. We do not have evidence yet that
the human brain is affected in this way. "We cannot exclude that after
some decades of often daily use, a whole generation of users may suffer
negative effects maybe already in their middle age."

In California, talking on cell phones is the leading cause of car
crashes that can be blamed on distracted drivers. "I didn't think cell
phones would be the highest category,'' says Spike Helmick, of the
California Highway Patrol. "But I was wrong. We have to be concerned.''
When state officials studied what distracted drivers in 9,000 crashes,
cellphone use was the cause of 891 of them, almost one in 10. This was
followed closely by fumbling with the radio or CD player, which resulted
in 768 crashes. Disciplining kids in the car, eating and smoking were
other leading causes, but were far behind the first two.
However, most crashes aren't caused by driver distraction. Out of the
522,562 crashes in California in 2001, only 51,107 were due to driver
inattention. Speeding is the cause of most crashes.

But highway patrol spokesman Tom Marshall thinks the number of crashes
caused by cellphones is much higher. He says, "Any right-minded person
knows a driver probably won't 'fess up to the fact he was on a cell phone.''

Retired Sgt. Bruce Raye says he never handled an accident involving a
cellphone during his 10 years in the San Jose police traffic division.
But he also said that such reports could be low because officers don't
remember to ask about a cellphone, due to all the other information
they're required to put in an accident report. "You can't get them to
write the correct court date on a ticket, let alone remember if a cell
phone was related to the accident,'' he says. "There are probably many
more accidents where cell phones contributed.''

But driver Andrea Puck of Santa Clara says, "If the risky behavior truly
is the conversation, then banning the device is as ridiculous as banning
conversation while driving. If you really want to get rid of
distractions while driving, ban children from cars.''

Maybe we should stick to ESP. The U.S. government tried it with great
success, although they're keeping it a secret.

http://www.unknowncountry.com/news/?id=2385

Cellphone Weapons
02-Apr-2003

Don't use your cellphone just to make calls use it to attack other
cellphones! The design firm Ideo has invented cellphones that discourage
people from making unnecessary calls or zap other cellphone users who
talk too long or too loudly in public. One design comes with two metal
plates attached to it that can send an increasing electric shock to the
people you're talking to. Another phone is shaped like a musical
instrument. "It looks like a snake that has swallowed a mobile phone,"
says designer Graham Pullin. In order to make a call, you have to stand
up and play a tune on the musical phone. "It seems inconceivable that
someone would stand up and play it in the middle of a crowded restaurant
so it is a good litmus test about where it is appropriate to make a
call," Pullin says. Then there's the catapult phone, which allows users
to aim their phone at someone talking on another phone nearby and send a
sound that disrupts their conversation. Maybe the best design is a quiet
phone that allows you to have a silent conversation. Instead of
speaking, you simply press a button to reply "yes" or "no" the person on
the other end of the line.

We have to admit we like the catapult phone best. Now can someone design
a zapper for those loud "boom box" car radios? There are certain people
we can always talk to quietly, without disturbing anyone else.

http://www.unknowncountry.com/news/?id=2560