26 November 2001
CLONED HUMAN EMBRYO SPARKS ETHICS DEBATE
Despite the current excitement over the cloning of a human embryo, this should not be seen as the first scientific or corporate step along the path of drastic experimentation with human life.
According to Richard Hayes:
"Advanced Cell Technologies (ACT) of Worcester, Massachusetts, announced
last year that it had created a viable human/bovine embryo by implanting
the nucleus of a human cell into the egg of a cow. No laws exist
that would have prevented this transspecies embryo from being implanted
in a woman's uterus in an attempt to bring a baby to term. The baby
would contain a small but significant proportion of cow genes."
[from "In the Pipeline: Genetically Modified Humans?"]
Meanwhile, the Sunday Times reported more than a year ago on how, "Scientists have successfully produced an embryonic pig-human hybrid. Human DNA was inserted into pig cells which became tiny embryos."
Pig-Human Hybrid: Cloning Teams Cross Pig and Human DNA
The Sunday Times
Jonathan Leake and Nick Fielding
October 8, 2000
SCIENTISTS have successfully produced an embryonic pig-human hybrid. Human DNA was inserted into pig cells which became tiny embryos. The researchers have not revealed what happened to them, but suggest they could have been grown further by being implanted into a womb - and that either a pig or a human mother would have been suitable. The intentions of the researchers are not made clear in an application they have submitted to the European Patent Office. However, such embryos would be ideal for research into therapeutic cloning, when cells are cloned, grown into tissues such as nerve cells and then used to treat a patient.
The researchers, from Stem Cell Sciences in Australia and Biotransplant in America, both big players in the biotechnology industry, took a cell from a human foetus, extracted the nucleus and then inserted it into a pig's egg cell. Two embryos were grown to the 32-cell stage, which took a week.
Experts in medical ethics are deeply concerned about the patent application, which has a strong chance of being granted. They say the research exploits loopholes in European law. It is not illegal because the embryo is not technically human. Dr Richard Nicholson, editor of the Bulletin of Medical Ethics, said: "This kind of research depends on devaluing human beings." Nobody knows whether the hybrid embryos could have become living beings. They would be much more human than pig because about 97% of DNA is in the nucleus, which was human. There would, however, be some effect from the 3% of DNA from the pig.
Cloned human embryo sparks ethics debate
Last Updated: Mon Nov 26 00:37:23 2001
BOSTON - A U.S. company announced Sunday that it has cloned the first human embryo using the same technique that produced Dolly the Sheep back in 1997.
The scientists said they have no intention of cloning human beings, but are hoping to use the DNA-swapping procedure to help patients combat a wide range of medical problems by giving them replacement cells.
October's lab work is outlined in Sunday's online edition of the journal Scientific American, which can be viewed without a subscription. The complete report is being published in The Journal of Regenerative Medicine.
The researchers, who work for Advanced Cell Technology in Worcester, Mass., said they cloned a six-cell human embryo.
"They were such tiny dots, yet they held such immense promise," the scientists wrote in Scientific American. "After months of trying, on October 13, 2001, we came into our laboratory - to see under the microscope what we'd been striving for - little balls of dividing cells not even visible to the naked eye.
"Insignificant as they appeared, the specks were precious because they were, to our knowledge, the first human embryos produced using the technique of nuclear transplantation, otherwise known as cloning."
Instead of using sperm, the six-cell embryo was created by removing DNA from a human egg and injecting it with the DNA of a skin cell, according to the company.
But the scientists were quick to point out they have no plans to transplant such an embryo into a woman's womb.
"This work sets the stage for human therapeutic cloning as a potentially
limitless source of immune-compatible cells for tissue engineering and
transplantation medicine," said Dr. Robert P. Lanza, vice-president of
medical and scientific development at ACT.
October 1990: National Institutes of Health officially begin the Human Genome Project.
July 1995: Scottish scientists clone two sheep, named Megan and Morag, from differentiated embryo cells.
February 1997: Scottish scientists clone an adult mammal for the first time, producing a lamb named Dolly, from a 6-year-old ewe, using tissue taken from the ewe's udder
July 1998: Researchers at the University of Hawaii clone 50 mice in three generations from a single mouse.
April 1999: Geneticists at Tufts University in Massachusetts clone three goats, altering the goats' genetic code to produce a protein in their milk to treat heart attacks and strokes.
2000: Oregon researchers produce a rhesus monkey named Tetra by splitting early-stage embryos and then implanting the pieces into the mother.
November 2001: Massachusetts research company reports it has cloned
the first human embryo, a development it said was aimed at producing genetically
matched replacement cells for patients with a wide range of diseases.
"Our intention is not to create cloned human beings, but rather to make life-saving therapies for a wide range of human disease conditions."
Some religious and political leaders are still outraged by the announcement.
The U.S. National Right to Life Committee accused the company of creating human embryos "for the sole purpose of killing them and harvesting their cells."
Several U.S. states have banned human cloning, and Congress is considering doing so. The House of Representatives passed a ban in the summer, but the Senate didn't discuss the measure.
In Canada, the federal government has proposed legislation that would
make it illegal to "create or participate in the creation of a human clone."
The bill is being reviewed by the Commons health committee.
FROM MARCH 12, 2001: Federal government plans to move on cloning law
Democratic Sen. Patrick Leahy said on Sunday he thinks it is just a matter of time before a human being is cloned. "I find it troubling," he said.
Senate majority leader Tom Daschle said he supports cloning technology for scientific purposes, but not for reproduction.
"We vehemently oppose any cloning for purposes of human replication," he said. "I don't think there's any need to do that."
Daschle also said he believes there is strong bipartisan opposition
in Congress to human reproductive cloning.
FROM JAN. 23, 2001: Britain allows cloning of human embryos for research
Saying the results are exciting, if preliminary, the scientists ultimately
want to create stem cells so they can produce replacement tissue to treat
diabetes, heart disease, spinal injuries, and many other ailments.
Written by CBC News Online staff
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