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Sci Tech
Making human organs — a mirage
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Chances of producing organs using embryonic stem cells are almost nil. Stem cells can only be used to treat diseases where the root cause is a defective cell.
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Success rate of cloning animals like Dolly is less than 2 per cent. Animal cloning should be first perfected before it is tried out on humans.
EMBRYONIC STEM cells hold great promise to treat diseases like diabetes, Parkinson's disease to name a few.
But hopes of producing human organs like spare parts that can be transplanted as and when required may only be a figment of imagination. Indicating this Harry Griffin, Assistant Director of Roslin Institute in U.K which cloned Dolly said human organs are far too complicated to be produced in a laboratory or commercially.
"Chances of producing organs using embryonic stem cells are almost impossible. It can only be used to treat diseases where the root cause is a defective cell," said Dr. Griffin who was in India as part of the India-U.K. Science Festival team. "These exaggerated claims have only helped biotechnology get more attention and funds from policy makers around the world."
Diseases like diabetes and Parkinson's are caused due to defective cells. Transplanting healthy cells produced from embryonic stem cells is the only way to treat such diseases.
Already, transplanting healthy islet cells help treat diabetes in humans. In the case of mice, islet cells formed from embryonic stem cells have been transplanted to treat diabetes. These embryonic stem cells were derived by cloning normal mice cells.
This kind of therapy using cells also known as `cell therapy' has its own problems or disadvantages.
For instance, if mutations happen in the cells that are transplanted into the organ then this continues and could lead to some complications. "This is a major area of concern," Dr. Griffin said. "While removing a malfunctioning organ that has been transplanted is quite easy, it is not so in the case of cells. This is because it will be difficult if not impossible to identify and recover the mutated cells." This is a major area of research to be able to identify the transplanted cells and new cells that have been produced by them.
Similarly, drugs designed and tailor made to individual need is more of a hype. It would not be economical to produce such drugs. Moreover it is dogged by a practical problem - a basic requirement of drug production is to test in on a group of people for safety and other aspects before it is commercially produced.
But what may be possible is to produce a drug for a group of people who do not respond well to a particular medicine.
This would be particularly true for people suffering from a particular disease resistant to all existing medicines.
Producing embryonic stem cells from normal human cells by cloning should be avoided he said.
"Cloning should not resorted to in the case of humans even if it is for a therapeutic purpose," Dr. Griffin said. "The success rate of cloning is less than 2 per cent, the technique is still in its infancy. And more importantly it is easy to get human embryos than human eggs." But will the technology develop if scientists are not allowed to pursue it? "Cloning of animals should be first perfected before it is tried out on humans," he said.
But will egg donation overcome the biggest hurdle faced in the case of human cloning? "Probably. But then should women be put through such trouble when embryos are anyway available? Perhaps we may develop a technology to produce eggs than harvest it from women," Dr. Griffin said.
Cloning for reproduction is more hype than reality. For one, it is riddled with many problems, both ethical and scientific.
Add to this, the very low success rate of cloning. "It's nothing but nonsense. And why should someone try this when the success rate of IVF is nearly 17 per cent. Cloning is never going to be more efficient than this," he said.
R. Prasad
in Chennai
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