Word: dna
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Dates: during 2000-2009
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...graduate student at the University of Chicago in the late 1970s, he baffled peers by enthusiastically throwing himself into the study of topoisomerases--the enzymes whose job it is to twist circular DNA molecules into tight coils. No one knew how the twisting occurred until Brown, playing with a rubber band, realized that by creating a break in the band, curling the opened band into a figure eight, then resealing the loose ends, he could introduce two twists into the rubber band for every split. "Everybody laughed and thought I was crazy," Brown recalls. But as it turned out, that...
Today the only maps he's interested in are the ones that can guide him through the byways of human DNA. "It's like exploring unknown territory," he says. "We're toddlers just now starting to discover our world...
Rather than rely on indirect cancer markers like PSA, which have an unacceptably high rate of false positives, Sidransky zeroed in on DNA shed directly from tumors. Many solid tumors, it turns out, result from mutations in stretches of DNA that are repeated several times. Finding these abnormal DNA snippets in urine or saliva could mean a cancer is just beginning to take root. In a small pilot study of bladder-cancer patients, one screen that Sidransky developed picked up more than 90% of tumors--a hit rate that could revolutionize the early detection and treatment of bladder cancer...
...footprints than others. In the urine of a patient with bladder cancer, for example, more than half the genetic material could derive from the tumor, making detection relatively straightforward. The sputum of a lung-cancer patient, on the other hand, is much more diverse; less than 1% of its DNA is traceable to cancer. Clearly, other genetic clues will have to be developed, and Sidransky is already tracking down several of them. The challenge, to his delight, never ends...
...living cell bustles with molecular activity. Lilliputian protein motors ferry goods and services. Enzymes curl and unfurl. Even on its calmest days, the DNA double-helix twists, unwinds and wiggles like a loopy spring...