Kita belum sempat memikirkan soal stem cells. Konon, di Amerika sendiri stem cells terhalang oleh Presiden Bush, maklum karena dia berasal dari Bible belt. Sekarang orang sudah menduga, nantinya stem cells bukan saja mengganti sel yang cacat, tapi dapat mereparasi yang sakit, yang nantinya bakal berkembang jadi sakit jantung misalnya. Salam, RM
[EMAIL PROTECTED] Stem Cells to the Rescue By Kristen Philipkoski | Also by this reporter Page 1 of 1 11:00 AM Oct. 07, 2004 PT For years, researchers have touted stem cells as potential replacements for cells damaged by disease. Now, they're finding that stem cells may not only replace defective cells, but rescue them. The results of a study published in the Oct. 8 issue of Science show stem cells have special properties that allow them to rescue, or repair, heart cells. Scientists injected the stem cells into very young mouse embryos that had been engineered to develop a lethal heart disorder. While these pregnancies would normally spontaneously abort midway through gestation, half of the approximately 75 offspring were born with healthy heart. Fraidenraich and his team merely hoped to extend the pregnancies, but didn't expect them to result in healthy births. "We were expecting to prolong development for two to three more days by injection of embryonic stem cells," Fraidenraich said. "But we were surprised that these mice were born, with 50 percent of those becoming adults." Stem cells have the ability to become every cell in the human body, and researchers hope to harness this ability to cure or treat various diseases. This latest discovery could provide a new approach to stem-cell research focusing on cell rescue rather than replacement. A companion article to Fraidenraich's study published in the same issue of Science suggests that by using the "modern tools of bioinformatics, genomic databases and microarrays," researchers could discover what factors are leading to cell rescue. Those factors, whatever they may be, could be used directly as treatments, circumventing the need to use stem cells. "This discovery suggests that embryonic stem cells can be used to find factors that can rescue lethal birth defects, and this could also have relevance to a variety of other defects as well," said Ken Chien, a stem cell researcher at the University of California at San Diego, and one of the authors of the companion article. "This does not mean that embryonic stem cells themselves will have to be the therapy, but rather since they release many different kinds of factors, they can be used to identify proteins that themselves could have therapeutic effects." Other researchers have also begun to look at stem cells as rescuers rather than replacements. In 2001, John Gearhart, a stem cell researcher at Johns Hopkins University, led a group that injected stem cells (taken from voluntarily aborted fetuses) into rats engineered to exhibit symptoms of Amyotrophic Lateral Sclerosis, or Lou Gehrig's disease, rendering their back legs useless. The treated mice regained some, but not all, movement in their hind legs. At the time, Gearhart thought the stem cells might have turned into replacement cells that took over for motor neurons damaged by the disease. But at a stem cell conference in San Diego on Saturday, Gearhart said he now thinks differently. "Now we believe the improvement is due to rescue of the animals' own motor neurons," he said. Fraidenraich said he believes both replacement and rescue are likely important. To learn more about the stem-cell rescue phenomenon, some researchers would like to use therapeutic cloning technology, also known as somatic cell nuclear transfer. They'd like to create a clone of, say, an ALS patient in a petri dish. After the cloned embryo develops for a few days, they would remove stem cells from it. Then they would grow the stem cells into motor neurons, study them to find out exactly what goes wrong as they develop, and experiment with ways to interfere with the cell malfunction. "We would certainly like to use cells derived from humans with ALS," Gearhart said. But research using human embryonic cells in the United States is limited by President Bush's executive order that states that the National Institute of Health -- the benefactor of most basic research in the United States -- can only fund the study of embryonic stem cells derived before Aug. 9, 2001, the day Bush declared his plan. Ian Wilmut, the researcher who cloned Dolly the sheep at the Roslin Institute in Edinburgh, Scotland, has applied for a license to perform therapeutic cloning experiment to study ALS. The United Kingdom has outlined a plan that allows therapeutic cloning and study of embryonic stem cells under certain regulations. The new study is a boon for embryonic stem cell research as a whole, and in particular for the treatment of heart disease. "In my opinion," said UC San Diego's Chien, "this is one of the most significant papers in the arena of cardiac stem cell therapy to date." ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/BRUplB/TM --------------------------------------------------------------------~-> *************************************************************************** Berdikusi dg Santun & Elegan, dg Semangat Persahabatan. Menuju Indonesia yg Lebih Baik, in Commonality & Shared Destiny. www.ppiindia.shyper.com *************************************************************************** __________________________________________________________________________ Mohon Perhatian: 1. Harap tdk. memposting/reply yg menyinggung SARA (kecuali sbg otokritik) 2. Pesan yg akan direply harap dihapus, kecuali yg akan dikomentari. 3. 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