Carcasses of GM animals threaten water sources

[Guest guest]

GMW: Carcasses of GM animals threaten water sources

" GM WATCH " <info

 

Sun, 24 Apr 2005 18:21:15 +0100

 

 

 

 

GM WATCH daily

http://www.gmwatch.org

------

If you find human genes in plants disturbing, welcome to the world of

chimeras and the College of Agriculture, Biotechnology and Natural

Resources, University of Nevada, Reno (UNR), USA.

 

" Employees of the project have been accused of allowing carcasses of

dead, genetically altered animals to rot in areas where water sources

could be contaminated. " (item 1)

 

" In Nevada, there are sheep whose livers and hearts are largely human. "

(item 2)

 

" Newspaper reports revealed in December that 38 pregnant ewes died in

2002 at UNR's farm on McCarran Boulevard in Reno after being locked in a

paddock without food or water. " (item 1)

 

1.UN-Reno farms could be inspected by health officials

2.Of Mice, Men and In-Between

------

1.UN-Reno farms could be inspected by health officials

ASSOCIATED PRESS, April 22, 2005

 

CARSON CITY, Nev. (AP) - Reacting to charges of animal abuse at the

University of Nevada, Reno, lawmakers voted 38-3 Friday to allow local

health officials to inspect agricultural programs run by the state

universities.

 

Assemblywoman Sheila Leslie, D-Reno, said she introduced AB523 after

constituents concerned about possible water contamination at a UNR farm

learned that the local health inspector lacked authority to test its

water.

 

Employees of the project have been accused of allowing carcasses of

dead, genetically altered animals to rot in areas where water sources

could be contaminated.

 

Assemblyman John Marvel, R-Battle Mountain, Assemblyman Pete

Goicoechea, R-Eureka, and Assemblywoman Sharron Angle, R-Reno, voted

against the

bill.

 

Newspaper reports revealed in December that 38 pregnant ewes died in

2002 at UNR's farm on McCarran Boulevard in Reno after being locked in a

paddock without food or water.

------

2.Of Mice, Men and In-Between

Scientists Debate Blending Of Human, Animal Forms

By Rick Weiss

Washington Post Staff Writer

Saturday, November 20, 2004

http://www.washingtonpost.com/ac2/wp-dyn/A63731-2004Nov19?language=printer

 

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.

 

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.

 

" This is an area where we really need to come to a reasonable

consensus, " said James Battey, chairman of the National Institutes of

Health's

Stem Cell Task Force. " We need to establish some kind of guidelines as

to what the scientific community ought to do and ought not to do. "

 

Beyond Twins and Moms

 

Chimeras (ki-MER-ahs) -- meaning mixtures of two or more individuals in

a single body -- are not inherently unnatural. Most twins carry at

least a few cells from the sibling with whom they shared a womb, and most

mothers carry in their blood at least a few cells from each child they

have born.

 

Recipients of organ transplants are also chimeras, as are the many

people whose defective heart valves have been replaced with those from

pigs

or cows. And scientists for years have added human genes to bacteria

and even to farm animals -- feats of genetic engineering that allow those

critters to make human proteins such as insulin for use as medicines.

 

" Chimeras are not as strange and alien as at first blush they seem, "

said Henry Greely, a law professor and ethicist at Stanford University

who has reviewed proposals to create human-mouse chimeras there.

 

But chimerism becomes a more sensitive topic when it involves growing

entire human organs inside animals. And it becomes especially sensitive

when it deals in brain cells, the building blocks of the organ credited

with making humans human.

 

In experiments like those, Greely told the academy last month, " there

is a nontrivial risk of conferring some significant aspects of humanity "

on the animal.

 

Greely and his colleagues did not conclude that such experiments should

never be done. Indeed, he and many other philosophers have been

wrestling with the question of why so many people believe it is wrong to

breach the species barrier.

 

Does the repugnance reflect an understanding of an important natural

law? Or is it just another cultural bias, like the once widespread

rejection of interracial marriage?

 

Many turn to the Bible's repeated invocation that animals should

multiply " after their kind " as evidence that such experiments are wrong.

Others, however, have concluded that the core problem is not necessarily

the creation of chimeras but rather the way they are likely to be

treated.

 

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. "

 

A Research Breakthrough

 

The potential power of chimeras as research tools became clear about a

decade ago in a series of dramatic experiments by Evan Balaban, now at

McGill University in Montreal. Balaban took small sections of brain

from developing quails and transplanted them into the developing

brains of

chickens.

 

The resulting chickens exhibited vocal trills and head bobs unique to

quails, proving that the transplanted parts of the brain contained the

neural circuitry for quail calls. It also offered astonishing proof that

complex behaviors could be transferred across species.

 

No one has proposed similar experiments between, say, humans and apes.

But the discovery of human embryonic stem cells in 1998 allowed

researchers to envision related experiments that might reveal a lot

about how

embryos grow.

 

The cells, found in 5-day-old human embryos, multiply prolifically and

-- unlike adult cells -- have the potential to turn into any of the

body's 200 or so cell types.

 

Scientists hope to cultivate them in laboratory dishes and grow

replacement tissues for patients. But with those applications years

away, the

cells are gaining in popularity for basic research.

 

The most radical experiment, still not conducted, would be to inject

human stem cells into an animal embryo and then transfer that chimeric

embryo into an animal's womb. Scientists suspect the proliferating human

cells would spread throughout the animal embryo as it matured into a

fetus and integrate themselves into every organ.

 

Such " humanized " animals could have countless uses. They would almost

certainly provide better ways to test a new drug's efficacy and

toxicity, for example, than the ordinary mice typically used today.

 

But few scientists are eager to do that experiment. The risk, they say,

is that some human cells will find their way to the developing testes

or ovaries, where they might grow into human sperm and eggs. If two such

chimeras -- say, mice -- were to mate, a human embryo might form,

trapped in a mouse.

 

Not everyone agrees that this would be a terrible result.

 

" What would be so dreadful? " asked Ann McLaren, a renowned

developmental biologist at the University of Cambridge in England.

After all, she

said, no human embryo could develop successfully in a mouse womb. It

would simply die, she told the academy. No harm done.

 

But others disagree -- if only out of fear of a public backlash.

 

" Certainly you'd get a negative response from people to have a human

embryo trying to grow in the wrong place, " said Cynthia B. Cohen, a

senior research fellow at Georgetown University's Kennedy Institute of

Ethics and a member of Canada's Stem Cell Oversight Committee, which

supported a ban on such experiments there.

 

How Human?

 

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.

 

It is important to have learned that human and pig cells can fuse,

Platt said, because he and others have been considering transplanting

modified pig organs into people and have been wondering if that might

pose a

risk of pig viruses getting into patient's cells. Now scientists know

the risk is real, he said, because the viruses may gain access when the

two cells fuse.

 

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.

 

Zanjani's goal is to make the humanized livers available to people who

need transplants. The sheep portions will be rejected by the immune

system, he predicted, while the human part will take root.

 

" I don't see why anyone would raise objections to our work, " Zanjani

said in an interview.

 

Immunity Advantages

 

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. "

 

 

 

----------------