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The Strait Times, Singapore April 25, 2003 Leap in stem cell research fuels call to ease US restrictions American scientists worry that Bush policy on embryos may force them to lag behind as advances are made in S'pore and Johns Hopkins WASHINGTON - A series of important advances - including one from Singapore - has boosted the potential of human embryonic stem cells to treat heart disease, spinal cord injuries and other ailments, but researchers in the United States say they are unable to take advantage of the new techniques under a government policy that requires federally supported scientists to use older colonies of stem cells. Now pressure is building from scientists, patient advocates and members of Congress to loosen the embryo-protecting restrictions imposed by President George W. Bush, with some on Capitol Hill saying they want to take up the issue next month. Stem cells obtained from five-day-old human embryos can morph into all kinds of human tissues and appear capable of regenerating ailing organs. But while newer and safer versions of the cells have been created recently, the policy imposed by Mr Bush in 2001 puts those cells off- limits to any scientist whose work is supported with federal money. Supporters of embryo cell research have long grumbled about the policy, but have acknowledged that their complaints were largely theoretical because there was still plenty to learn from older cells. The unexpectedly rapid advent of more medically promising cells and the possibility of human studies within the next year or so have changed that equation, they say, making the Bush policy a real barrier to progress. The older cells allowed under the Bush plan are problematic because they have been grown in mixtures with mouse tumour cells. The tumour cells, known as 'feeder' cells, secrete crucial, though as yet unidentified, nutrients that help nourish human embryo cells. But they can also pass mouse viruses or other microbes to the human stem cells, which means the stem cells could end up sickening patients instead of curing them. Recently, however, scientists have learnt how to grow human embryonic stem cells without mouse cells. The new stem cell colonies, or 'cell lines', appear ideal for use in clinical trials, scientists say. But they remain unavailable to the vast majority of US stem cell researchers - most of whom depend on federal grant money - because the US policy requires scientists to work only with cells from embryos destroyed before Aug 9, 2001. The goal was to prevent further destruction of stored human embryos, but it also limits researchers to cell lines tainted by contact with mouse cells. The White House indicated that it has no intention of changing its position. The advent of medically-promising cells began when researchers from Singapore published a landmark report last year showing that human embryonic stem cells could be maintained in culture dishes if they were accompanied by cells from 14-week-old aborted human foetuses, instead of mouse cells. Then, last month, scientists at Johns Hopkins University made another leap, showing that human embryonic stem cells could thrive in a culture system containing adult human bone marrow cells, which apparently secrete all the growth factors the stem cells need. Now, many are scrambling to find other recipes that support stem-cell growth. But scientists receiving federal grant money are not able to study any of the newly derived lines under the current Bush policy, because they come from embryos donated to research after August 2001. Opponents of the current policy said the US stands to fall behind other countries with access to more advanced cell lines and more open research policies. \-- LAT-WP Two new findings WASHINGTON - Heart failure patients who got injections of their own bone marrow cells got better, and may have grown new heart tissue or blood vessels, United States and Brazilian researchers reported earlier this week. Their findings could offer a way to treat a hopeless and deadly condition. 'If our findings are confirmed in larger trials, this procedure could lead to an effective treatment for severe heart failure, and perhaps to a new form of gene therapy,' Dr James Willerson, president of the University of Texas Health Science Center at Houston, said in a statement. 'The patients we treated had end-stage heart failure,' Dr Willerson said in a telephone interview. Such patients often have only one hope of recovery - a heart transplant - and hearts for transplant are in desperate shortage. Dr Willerson's team wanted to see if blood stem cells found in the bone marrow might help regenerate the heart muscle or the blood vessels feeding the heart. Writing in the journal Circulation, the team said the treated patients had better heart function and less chest pain. 'Either these stem cells became new blood vessel and new heart muscle cells, or their presence stimulated the development of one or both,' Dr Willerson said. \-- Reuters WASHINGTON - Baby teeth may be a source of powerful stem cells that hold promise for nerve and brain repairs, according to research. The versatile cells found in tissue inside the teeth may help doctors replace lost or diseased nerve tissue, researchers said. Stem cells, which have the ability to adapt to many functions, have been found in adult teeth as well as in bone, blood and other tissues, said study leader Shi Song Tao, a National Institute of Dental and Craniofacial Research biologist. Baby teeth, or deciduous teeth, represent a constant, renewable source of stem cells that can be harvested easily, Dr Shi said. Dr Shi made the discovery after his six-year-old daughter lost four teeth earlier this year. 'I took them to the lab and found there was still some tissue inside,' he said. 'The stem cells inside grow very well.' \-- Bloomberg SOURCE: The Strait Times, Singapore http://straitstimes.asia1.com.sg/storyprintfriendly/0,1887,185246,00.h tml? * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn