When it comes to people, said Dr. Hsieh, it might be similarly effective to give the therapy in the first week after a heart attack, when stem-cell activity is highest.

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In particular, low-status individuals showed high levels of activity in genes associated with the production of various immune-related cells and chemical signalling factors, as well as those to do with inflammation (a general immune response that involves tissue swelling and increased immune-cell activity in the affected area).

ECONOMIST: Social status and health

He was able to get in touch with his wife and son and daughter while in the car driving to his Maryland home, but it was difficult because of all the cell-phone activity.

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The idea that more brain cell activity could lead to more amyloid-beta build up is an exciting, if sobering, finding.

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The findings of the study, which examined the subjects during just one 50-minute exposure, raise a key question, the researchers said: What, if any, are the long-term consequences of repeated increased brain activity due to exposure to cell phone radiation?

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It is also suspected that brain cell death in Parkinson's patients is caused by over-activity of another brain chemical called glutamate.

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They do this by interfering with the activity of the messenger RNA strands that transfer genetic information from the cell's nucleus to its protein-making machinery.

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Lapatinib, it turns out, also inhibits the activity of a protein called the epidermal growth factor receptor, which has been found to be important for stem-cell proliferation.

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And the machines can only test for one event at a time--say, monitoring one enzyme's activity or seeing if a compound binds to a target on a cell.

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