Scientists at Stanford University announced last week that they would begin trying to clone human cells. Their goal, they say, is not to make copies of human beings but to make so-called stem cells, which have shown promise for research into Parkinson's Disease, diabetes, paralysis and scores of other ailments.

Some experts say this approach could turn out to be scientifically and ethically superior to the current method for getting embryonic stem cells, which requires the destruction of human embryos.

Still, this particular application of human cloning, as well as human cloning in general, is still under fire from abortion opponents and others. The cells would first have to be made to grow into human embryos, which may have the potential to become babies if transplanted into a woman's uterus.

The Stanford work, if it succeeds, could be a boon to medical research, said Peter Donovan, who does work on animal stem cells at Thomas Jefferson University Hospital in Philadelphia.

The Stanford researchers announced that they would try the same cloning technique used to make Dolly the sheep. They would transfer the DNA from the cell of an adult into an unfertilized egg cell. The resulting cell would grow into a microscopic embryo that could then be prompted to grow into a collection of embryonic stem cells.

In sheep, mice, cows and a few other species, embryos created this way have been implanted into females and successfully grown into animals.

But the embryos can also be nurtured to create groups of stem cells. These cells are exciting to medical science because under different conditions they can be encouraged to grow into hundreds of different types of tissue - bone, skin, heart, pancreas - and these might be used for transplants.

Cloning provides an alternative to the existing sources of embryonic stem cells, which include leftover human embryos made in fertility clinics, human embryos specially created in laboratories from egg and sperm, and aborted fetuses.

Abortion opponents and others object to this research because it destroys something that could potentially become a human life. But University of Pennsylvania ethicist Arthur Caplan said that cloning shouldn't raise the same objection because it's not clear that a cloned embryo has the potential to become a person.

Scientists have found it difficult to make animals from cloning, and no one has yet used cloning to make a human baby, though a few fringe groups claim they are close.

Scientists say cloned cells could prove much more useful medically than cells taken from embryos because, in the future, doctors might create replacement tissues by cloning a patient's own cells. That would eliminate the very significant danger of rejection that often happens with tissue or organ transplants.

Donovan said the Stanford announcement was welcome news because two years ago the Bush administration put some severe limits on federally funded work in the field of embryonic stem cells.

Under current law, scientists cannot use federal funds for stem cell research that destroys human embryos, though they can use cells from 64 "lines" that have already been made from embryos.

Some, including Donovan, say they are skeptical that all these lines will be available and usable.

The Stanford research does not fall under these restrictions because it uses a $12 million private grant, rather than federal money. It could, however, become illegal under pending bills that would outlaw human cloning, said Penn's Caplan. Last year, Sen. Sam Brownback, R-Kan., introduced such an anti-cloning bill; it is considered likely to be passed in the current political climate.

Donovan said he thought the Stanford project had been helped by a California law that encourages research in embryonic stem cells.

The New Jersey legislature will be debating a similar bill this week. It would require health care professionals to give patients at fertility clinics information on donating unused embryos to research. It would also encourage the use of cloning to create stem cells.

"This bill seeks to balance the medical and ethical considerations of stem cell research, by affording fertility patients with an informed choice whereby unused embryos might be donated for scientific and medical advancement," said Senate Co-President Richard J. Codey (D., Essex), a prime sponsor of the bill. "As a national leader of medical and scientific research, New Jersey has an obligation to promote such advancement when it could end suffering for millions worldwide."

Source: Philadelphia Inquirer.

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