Radioactive Hearts
April 30th, 2009 | No Comments | Source: NY Times, ScienceScientists at Stockholm’s Karolinska Institute have proved that the human heart produces new muscle cells throughout normal adult life, raising hope that this regenerative prowess can be harnessed to replace cardiac tissue that had been damaged by heart attacks and other pathological conditions.
Conventional wisdom had been that the heart does not produce new cells and people died with pretty much the same ticker as the one they started out with.
But Jonas Frisen and colleagues determined that up to age 25, the heart replaces about 1% of its cells per year, and it continues doing so, albeit at gradually diminishing rates, through old age.
When it’s all said and done, nearly half the heart’s muscle cells are created during a normal lifetime, the scientists estimated.
The scientists knew that cell turnover rates could be quantified in animals by adding radioactive molecules to cells and observing how quickly the radioactivity disappears.
This can’t be done in humans for ethical reasons, but Frisen reasoned that above-ground nuclear weapons testing, which was done by several countries until 1963, had seeded the atmosphere with carbon-14, and this stuff would find its way into the food chain.
The net result would be that the DNA in the nuclei of all living creatures has been C-14 labeled more or less continually as a byproduct of the nuclear folly.
The C-14 remains in the cell for as long as it survives, but since C-14 levels have diminished since 1963, cellular loads of the stuff in more recently formed cells have also diminished. The amount of C-14 in a particular cell thus indicates when it was formed.
The clever work appears in Science.
Loren Field, a cardiologist at Indiana University, told the New York Times the goal now becomes “to try to tickle the system to enhance (cellular regeneration rates).”




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Laura Bix and colleagues used an eye-tracking device to quantify the visual inspection patterns of subjects as they scanned package labels on OTC pain killers and subsequently assessed the extent to which subjects could recall the information.
Phase 5 means the virus is causing multiple, widespread outbreaks.
“If the situation deteriorates further, it is inevitable that international travel will be materially dented as it was evident during the case of SARS,” Lim Hwee Hua, Singapore’s second minister for finance and transportation told the Wall Street Journal.
But the link between conscious and unconscious thought remains a hot topic among neurobiologists, even when sexual desire is not involved.
Some subjects solved it, some did not. What was interesting though was data from the EEG could be used to differentiate the insightful few from the rest of us.
It was marred by the inability to detect repeat fatalities due to misspellings of company names and failure to identify instances in which subsidiaries of the same company were involved.
Autistic 2 year-olds respond differently to visual and auditory cues presented in cartoons, an observation that
In some versions, the images appeared upside-down. In others, they were not.
Apparently, sound helped grab their attention.
“This line of research holds promise for development of new therapies based on redirecting visual attention in children with (autism),” said Thomas Insel, director of the National Institute of Mental Health.
In the US,
The ads in question are known as “sponsored links.”
One month after MinuteClinic struck a
The retail clinic business is not for the faint of heart.




