Thanks to MichaelP <email@example.com> for posting the following article:
Reuters Tuesday April 28 1:08 PM EDT
Firm reveals cross-species transplant studies
By Patricia Reaney
LONDON (Reuters) - A leading British transplant technology firm Tuesday
announced a plan to test the safety of transplanting animal organs to
Imutran, a British subsidiary of Swiss pharmaceutical giant Novartis, said
if the research went ahead as planned, it could lead to the first
transplant of a genetically altered pig's kidney and heart into humans.
But the company's chief operating officer, Dr. Corinne Savill, stressed
that safety concerns, particularly transmission of pig viruses to humans,
would be the top priority in assessing the value of the technology.
"If we find any evidence of transmission of pig viruses we will re-evaluate
our approach," she told a press briefing.
Xenotransplantation -- the use of organs, tissues or cells from a different
species -- was thought to be the ideal solution to the increasing demand
for replacement organs and the dwindling number of donors.
But then scientists discovered that two types of pig viruses were capable
of infecting human cells.
The viruses, called porcine endogenous retroviruses, cause no symptoms in
pigs. But scientists do not know if they can be transferred to humans
during transplants or if they can mutate and cause disease.
The finding sparked fears that cross-species transplants could lead to a
new pathogen like the human immunodeficiency virus that causes AIDS, and
provoked calls for a moratorium.
An international group, Doctors and Lawyers for Responsible Medicine,
launched a campaign in London earlier this year to ban xenotransplantion,
saying it could lead to an epidemic that could kill billions of people.
USA Today April 25-26, 1998
Scientists are learning how to repair genes that cause disease. But the
same process could alter a child's hair color, height or even intelligence.
Should we "fix" nature's genetic mistakes?
Scientists are contemplating a radical new step in medicine: changing the
genes that determine the destiny of our children, our children's children
-- and perhaps even the human race.
The procedure, "germ-line gene therapy," allows doctors to alter the genes
in a woman's egg, a man's sperm, or an embryo that is just a few days old.
The immediate goal is to eliminate inherited diseases such as Tay Sachs,
hemophilia or cystic fibrosis; hundreds of thousands of Americans carry
faulty genes that don't affect them, but can pass the diseases on to their
No one has yet tried germ-line gene therapy. It is prohibited in the United
States and several other countries, and so controversial that scientists
have only recently begun openly discussing it. To essentially prune off
parts of the genetic tree "really gets at who we are as humans," says
Gregory Stock, a biologist at the University of California at Los Angeles.
"But the argument for exploring this is so compelling I don't believe we
have a choice."
In the nucleus of every cell, 23 pairs of chromosomes carry DNA, the
genetic material that determines human traits.
Since 1990, physicians have tried to fix broken or missing genes in people
with inherited diseases by using something called somatic cell gene
therapy. But getting the engineered genes to the right place, such as the
blood cells or liver, and then making them work is very difficult. "It's
likely to be much easier with germ-line therapy," says Stock. That's
because geneticists may soon be able to correct a genetic flaw in the
sperm, egg or embryo -- in essence, knock out a bad gene before it can
Geneticists recently have learned how to construct handmade genes that can
be precisely targeted to replace broken genes, then switched on at will.
Michael Blaese, of the National Human Genome Research Institute in
Bethesda, Md., predicts in-vitro pregnancies will be the first candidates
for germ-line therapy, because a change made to the single fertilized egg
would be replicated in all the cells of the growing embryo. "
We should talk about [the procedure] now before someone does it," Blaese
says. Altering the germ line could pose unknown risks. A mistake could
introduce a harmful mutation that could be passed on to generations of
people. And because some "bad" genes also serve a useful purpose -- for
example, the gene that can cause sickle cell anemia also is associated with
resistance to malaria -- eliminating such genes could have serious
Critics worry that as scientists locate more genes, rich parents would
"design" their children to be taller or smarter than everyone else. But the
ability to wipe out terrible diseases from the human gene pool, or perhaps
even delay aging, could be too tempting to pass up, say geneticists.
"Imagine you will have a child," says Stock, "and you were told by your
doctor you could add a gene that would extend its life expectancy by 10
years. Would you opt for it?" We may have to answer that kind of question
within our own lifetimes.
By Christopher Joyce, a science editor for National Public Radio
Richard Wolfson, PhD
Consumer Right to Know Campaign,
for Mandatory Labelling and Long-term
Testing of all Genetically Engineered Foods,
500 Wilbrod Street
Ottawa, ON Canada K1N 6N2
tel. 613-565-8517 fax. 613-565-1596
Our website, http://www.natural-law.ca/genetic/geindex.html
contains more information on genetic engineering as well as
previous genetic engineering news items
Subscription fee to genetic engineering news is $35 for 12 months
See website for details.
To Unsubscribe: Email firstname.lastname@example.org with "unsubscribe sanet-mg".
To Subscribe to Digest: Email email@example.com with the command