Stem Cell Research: The Quest Resumes

www.time.com:
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Melton’s confidence is testament to the extraordinary advances in stem-cell science, some of which have brought the promise of breakthrough therapies for conditions like diabetes, Parkinson’s and heart disease closer than ever before. The cells filling petri dishes in freezers and incubators in Melton’s lab and others around the world are so vastly different — in provenance, programming and potential — from the stem cells of just two years ago that even the scientists leading this biological revolution marvel at the pace at which they are learning, and in some cases relearning, rules of development. Until recently, the field has revolved around either embryonic stem cells — a remarkably plastic class of cells extracted from an embryo that could turn into any of the body’s 200 tissue types — or their more restricted adult cousins, cells taken from mature organs or skin that were limited to becoming only specific types of tissue. On Jan. 23, after nearly a decade of preparation, the Food and Drug Administration approved the first trial of an embryonic- stem-cell therapy for a handful of patients paralyzed by spinal-cord injuries.
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