Has anyone else heard of Chimeras? These articles made me sick to my stomach. Does this sicken anyone else?
Http://msnbc.msn.com/id/6534243
(believe it or not, this is the condensed version)
In Minnesota, pigs are being born with human blood in their veins.
In Nevada, there are sheep whose livers and hearts are largely human.
In California, mice peer from their cages with human brain cells firing inside their skulls.
These are not outcasts from "The Island of Dr. Moreau," the 1896 novel by H.G. Wells in which a rogue doctor develops creatures that are part animal and part human. They are real creations of real scientists, stretching the boundaries of stem cell research.
Biologists call these hybrid animals chimeras, after the mythical Greek creature with a lion's head, a goat's body and a serpent's tail. They are the products of experiments in which human stem cells were added to developing animal fetuses.
Living test beds
Chimeras are allowing scientists to watch, for the first time, how nascent human cells and organs mature and interact — not in the cold isolation of laboratory dishes but inside the bodies of living creatures. Some are already revealing deep secrets of human biology and pointing the way toward new medical treatments.
But with no federal guidelines in place, an awkward question hovers above the work: How human must a chimera be before more stringent research rules should kick in?
The National Academy of Sciences, which advises the federal government, has been studying the issue and hopes to make recommendations by February. Yet the range of opinions it has received so far suggests that reaching consensus may be difficult.
During one recent meeting, scientists disagreed on such basic issues as whether it would be unethical for a human embryo to begin its development in an animal's womb, and whether a mouse would be better or worse off with a brain made of human neurons.
Imagine, said Robert Streiffer, a professor of philosophy and bioethics at the University of Wisconsin, a human-chimpanzee chimera endowed with speech and an enhanced potential to learn — what some have called a "humanzee."
"There's a knee-jerk reaction that enhancing the moral status of an animal is bad," Streiffer said. "But if you did it, and you gave it the protections it deserves, how could the animal complain?"
Unfortunately, said Harvard political philosopher Michael J. Sandel, speaking last fall at a meeting of the President's Council on Bioethics, such protections are unlikely.
"Chances are we would make them perform menial jobs or dangerous jobs," Sandel said. "That would be an objection."
But what about experiments in which scientists add human stem cells not to an animal embryo but to an animal fetus, which has already made its eggs and sperm? Then the only question is how human a creature one dares to make.
In one ongoing set of experiments, Jeffrey L. Platt at the Mayo Clinic in Rochester, Minn., has created human-pig chimeras by adding human-blood-forming stem cells to pig fetuses. The resulting pigs have both pig and human blood in their vessels. And it's not just pig blood cells being swept along with human blood cells; some of the cells themselves have merged, creating hybrids.
In other experiments led by Esmail Zanjani, chairman of animal biotechnology at the University of Nevada at Reno, scientists have been adding human stem cells to sheep fetuses. The team now has sheep whose livers are up to 80 percent human — and make all the compounds human livers make.
Perhaps the most ambitious efforts to make use of chimeras come from Irving Weissman, director of Stanford University's Institute of Cancer/Stem Cell Biology and Medicine. Weissman helped make the first mouse with a nearly complete human immune system — an animal that has proved invaluable for tests of new drugs against the AIDS virus, which does not infect conventional mice.
More recently his team injected human neural stem cells into mouse fetuses, creating mice whose brains are about 1 percent human. By dissecting the mice at various stages, the researchers were able to see how the added brain cells moved about as they multiplied and made connections with mouse cells.
Already, he said, they have learned things they "never would have learned had there been a bioethical ban."
Now he wants to add human brain stem cells that have the defects that cause Parkinson's disease, Lou Gehrig's disease and other brain ailments — and study how those cells make connections.
Scientists suspect that these diseases, though they manifest themselves in adulthood, begin when something goes wrong early in development. If those errors can be found, researchers would have a much better chance of designing useful drugs, Weissman said. And those drugs could be tested in the chimeras in ways not possible in patients.
Now Weissman says he is thinking about making chimeric mice whose brains are 100 percent human. He proposes keeping tabs on the mice as they develop. If the brains look as if they are taking on a distinctly human architecture — a development that could hint at a glimmer of humanness — they could be killed, he said. If they look as if they are organizing themselves in a mouse brain architecture, they could be used for research.
So far this is just a "thought experiment," Weissman said, but he asked the university's ethics group for an opinion anyway.
"Everyone said the mice would be useful," he said. "But no one was sure if it should be done."
<a note from monastic>
I found another site talking about this sci-fi-like experimenting with these poor half human life forms. These Scientists seem to see no value in their subjects horribly mutated lives, as if, their life has no real value.
This link brought up their supporter's name which, explained a lot to me. I don't know why it surprised me to see the Major Contributer of Funding for this type of experiment... Is CAN (Cure Autism Now).
http://www.nichd.nih.gov/autism/abstracts/goldowitz.htm
10 Mar 2005, 8:35 pm
