Tuesday, April 24, 2012

Anh ngữ Äặc biá»t 534 health (VOA)

Anh ngữ Ä'ặc biệt 534 health (VOA)

Chương trình học tiếng Anh cá»§a VOA: Special English Health Report - Stem Cells-Human Eggs. Xin hãy vào www.youtube.com Ä'ể xem các bài kế tiếp. New research could raise hope for women who are having trouble getting pregnant. For years, the thinking has been that women are born with all the eggs their bodies will ever produce. In fact, this has been the thinking not just about humans but all mammals. Then, in two thousand four, a researcher at Massachusetts General Hospital reported that adult female mice could produce new eggs. Now, Jonathan Tilly has extended his work and reported another discovery -- this time about human females. "We've isolated, essentially, the female equivalent of the stem cells that we know exist in men that actively make new sperm." He says having these cells now isolated opens up a lot of opportunities to consider. Stem cells are special kinds of cells. Starting in embryos just a few days old, they produce the many different cell ! types and tissues that form the body. In some adult tissues, stem cells produce replacements for damaged or worn out cells. In his new study, Jonathan Tilly and other researchers removed cells from ovaries. Ovaries are the female reproductive organs that produce eggs. The scientists did laboratory tests to make sure they had the right cells that they were looking for. Then they used what are known as culturing methods to grow the cells so they would divide and produce more cells. "And we could start with perhaps one ...





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