C14: From Australopithecines to Adipose Tissue
Radioactive carbon dating is most commonly used to determine the age of specimens that are thousands to millions of years old. But researchers at the Swedish Karolinska Institutet have used the method to look at decidedly younger samples, comparing the fat in the cells of healthy and obese individuals. Looking at the C14 content of triglyceride fats, they found that fat cells have a typical life span of 10 years, and during that time, the fats are turned over an average of six times in normal individuals. Obese individuals, on the other hand, had older fat, implying their cells were less able to break down fats. Older fat also correlated with an increased likelihood of a person's having insulin resistance. The authors said their results established fat turnover as "a novel target for prevention and treatment of metabolic disease." Their work appeared in the Sept. 25, 2011, advance online edition of Nature.
One Thing Leads to Another
Their growth can be due to very specific mutations, but cancer cells also tend to have much more whole-sale level problems with their DNA. Problems can include having the wrong numbers of whole chromosomes (which is called aneuploidy) as well as structural abnormalities such as chunks of DNA that are missing, or in the wrong place on a chromosome. Those structural abnormalities occur when DNA breaks are "repaired" incorrectly, and so the two types of damage have been considered …
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