Posted on 04/02/2009 11:48:59 PM PDT by neverdem
Carbon 14 from Cold War–era nuclear bomb tests allowed researchers to track cell birth
By monitoring carbon 14 emitted from Cold War–era nuclear bomb tests, researchers found that heart muscle cells continue to divide throughout adulthood, shows a study appearing in the April 3 Science. The low-level cell renewal may eventually be exploited to treat damaged hearts, says study coauthor Jonas Frisén of the Karolinska Institute in Stockholm.
The finding contradicts the belief of many scientists that the heart muscle cells sticking around until the end were present at birth.
“The dogma has always been that cell division in the heart pretty much stops after birth,” says Charles Murry of the University of Washington in Seattle, whose commentary on the new research appears in the same issue of Science. “In medical school, we teach that you’ll die with the heart cells you’re born with.”
To figure out whether the cells continue to be regenerated throughout life, researchers took advantage of an inadvertent marker that has found its way into heart cell DNA. The radioactive isotope carbon 14 was generated by aboveground nuclear test bombs during the Cold War. After the Limited Nuclear Test Ban Treaty took effect in 1963, carbon 14 levels in the atmosphere dropped, but amounts of the isotope remain in both the environment and humans.
“The carbon 14 in the atmosphere is mirrored in bodies,” Frisén says.
When cells divide, they use carbon 14 to build DNA, a phenomenon that can serve as a birthmark for new cells. By looking at DNA from people born before 1955, when the first nuclear bombs were tested, researchers could see whether heart cells were born after the people in the study were born. (Cells that did not divide after a person’s birth would not contain any carbon 14.) The...
(Excerpt) Read more at sciencenews.org ...
What's the signal?
I have not read the article, but my father’s heart is showing signs of muscle redevelopment (blood vessel propagation) in the years following a massive infarction which would have killed him if mom had not been standing there when he coded and called in the crash team.
This story is inaccurate. C14 naturally occurs and every living thing has C14 in it. When the animal dies, the C14 is not replaced and decays. That is the basis of Carbon dating.
(Unlike in archaeology studies, the half-life of 14C, about 5,700 years, does not affect these results.)
IMHO, the study took advantage of the increase of carbon 14 during that period of atmospheric bomb testing compared to the normal amount of carbon 14 in nature.
The Claim: Heart Attack Symptoms Differ According to Sex
FReepmail me if you want on or off my health and science ping list. Heaven forfend! The girls are different!
Exactly. The C14 levels around after the tests would have zoomed compared to normal background levels.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.