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The Daily Star Online Notion of ‘farming’ human tissues not that far-fetched Medicine Rania Abouzeid Daily Star staff “Physician heal thyself?” In a few years it could also be "patient heal thyself." Medical research is on the verge of perfecting a technology that promises to be the biggest breakthrough in biology since DNA was discovered in 1953. The know-how to regenerate damaged and diseased organs is rapidly moving from the realm of science-fiction to science-fact. So what is the agent of this revolution? Stem cells. Stem cells are the body’s “master cells.” They are the precursor (or “building block”) cells which when exposed to appropriate chemical cues can differentiate into any of the body’s 200-300 different cell types such as skin, bone, heart or brain. Once a cell becomes specialized, it loses the ability to become or function as another part of the body. These cells that can grow into a range of tissues are initiating a revolution in biology. Tissue repair results in scar formation in almost all tissues and organs with the notable exceptions of blood and bone. That is, a broken bone will heal through the formation of new bone, whereas the healing process in a damaged heart will result in non-functional scar tissue. Last week, researchers in the Un-ted States announced that stem cells taken from mouse bone marrow and transplanted into a damaged mouse heart turned into functioning cardiac tissue. The researchers said they would try the technique in Rhesus monkeys within a few months and that if all went well, clinical trials on people could begin in three years. Such tantalizing evidence opens up a myriad of possibilities. In addition to replacing scar tissue in hearts damaged by cardiac arrests or livers wracked by cirrhosis, the technology is being touted as a new hope for patients suffering diseases such as Parkinson’s or diabetes caused by a loss of particular cells. Even cancer, an enigma which science has been unable to solve, shows signs of responding to stem-cell treatment. An experiment conducted by a group from the US National Genome Research Institute reported in the April issue of the journal Nature that stem-cell therapy could provide new blood vessels to damaged hearts. Could this one day circumvent the need for bypass operations for blocked coronary arteries? Indeed, the therapy has the potential to negate the need for organ transplants altogether an astounding possibility that could save the lives of thousands of people around the world. So why aren’t billions of dollars being poured into this “mother of all cures,” this “miracle treatment,” by governments everywhere? What’s the catch? The source of the cells. Stem cells come from both adult tissue (usually the bone marrow) and from aborted fetuses or early-stage embryos created through in vitro fertilization. While private biotechnology corporations are undertaking research on embryos, governments are less enthusiastic. The US government has prohibited the use of taxpayer dollars to fund experimentation on embryos. A National Institute of Health Committee is due to meet in April in Washington to evaluate new applications by researchers seeking federal funds to work with embryonic stem cells. In January, the British House of Lords permitted the use of 14-day-old embryos “left over” from IVF to be used for research, making Britain the first country to allow such experimentation. Such procedures raise fundamental questions about the rights of the unborn and the ethics of creating a life in order to destroy it after harvesting its cells. Proponents counter that “unwanted” IVF embryos and aborted fetuses would have been discarded anyway, so why not use them for therapeutic purposes? Some people, including US President George W. Bush, argue that since stem cells can be extracted from adult tissue, embryos should not be used. However, research has indicated that adult cells may lack the flexibility of embryonic stem cells, although they can still give rise to a variety of cells. In other words, it might be hard to teach an old cell new tricks. Stem cells taken from a patient to regenerate the patient’s heart, for example, do have the advantage that they will not be rejected by the body’s immune system because they are not from a foreign source. Embryonic stem cells have this limitation and require immunosuppressant medication to counter rejection. Science, however, has other ways of getting around such limitations. Researchers are considering cloning as a solution to this problem. The idea is that a cloned embryo would be created to provide the stem cells and then destroyed. Needless to say, the idea is an ethical minefield. The controversy surrounding the issue has moved the technology to the top of political, ethical and scientific agendas around the world. Stem cell treatments are the future of medicine simply because their potential is astounding. The revolution will happen and sooner rather than later. DS 05/04/01 http://www.dailystar.com.lb/features/05_04_01_b.htm ********* ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn