US doctors approve stem cell research

America's doctors have defied President George Bush and the conservative tide by putting their stamp of approval on scientists engaged in stem cell research.

Doctors said the finding by the American Medical Association (AMA) that it was ethical to use cloning for research, but not to copy another human being, offered reassurance and a moral shield to those working on the science. Michael Goldrich, who heads the AMA's ethics committee, said: "This is giving guidance to physicians on the science and the ethics. We can't remain silent."

It also puts American doctors directly at odds with the Bush administration which opposes all forms of human cloning. The White House has endorsed two bills introduced in the House of Representatives this year seeking a total ban on cloning. Scientists say limits imposed by President Bush two years ago have crippled stem cell research.

The AMA's endorsement concerns the creation of early embryos to be used as a source of stem cells for research into diseases including diabetes and Alzheimer's. Some anti-abortionists oppose the research because, they argue, the embryos could potentially develop into humans.

Scientists said the AMA directive on cloning was adopted without dissent in Chicago on Tuesday.

The decision was criticised within hours by a small rightwing rival, the Christian Medical Association, which accused the AMA of "putting medicine on a slippery slope of unethical principles".

The AMA has been more conservative on bioethical issues than the National Academy of Science and other research organisations which adopted similar stands on cloning some time ago.

By setting out its position, the scientific community hopes to have a say in the laws under consideration to regulate human cloning.

"What they were trying to do was to make it OK for their doctors to pursue research," said Stephanie Lorenger, a biologist at the Federation of American Scientists.

However, the AMA, like the other scientific organisations, does not approve of cloning human beings. "Scientific societies have been advocating legislation banning reproductive cloning because they want to be seen as ethical and moral," Dr Lorenger said.

Such concerns have become paramount during recent years as universities battle with conservative forces over legislation which will define what is, and what is not, acceptable scientific practice in America.

New technologies are emerging. In New York state, a developmental biologist has applied for a patent for a human-chimpanzee hybrid, which could theoretically be used as a source for heart transplants.

But the White House has resisted such efforts. In Washington, the House of Representatives has twice voted to ban all forms of cloning - including stem cell research.

The bill has stalled in the Senate, but President Bush is personally opposed to cloning. Two years ago, he imposed strict limits on stem cell research capping the available sources of stem cells and denying federal funding for research using therapeutic cloning.