Monthly Archives: February 2000

Genetically engineered insulin distribution in mice

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Whether or not it ever leads
to any specific application in human beings, the recent announcement in
Science of a new technique for delivering insulin highlights the sort
of medical technologies that widespread genetic engineering is going to
unleash.

       Researchers at Ariad Pharmaceuticals
in Cambridge, Massachusetts genetically engineered cells to produce insulin
along side a protein that causes the insulin to clump up together within
the cell. The insulin is thus trapped in the cell as it is too large to
pass through the cell wall.

       The cells were then injected
into the muscles of diabetic mice and then fed a drug that causes the
clumping protein to split apart which releases the insulin and thereby
lowered the glucose level of the mice. Tim Clackson, the senior author
of the study published in Science, told the Associated Press, \”The insulin
stays in the compartments of the cell and has no toxicity or adverse effects.
It just sits there. Only when the animal receives the drug do the aggregates
break apart and then flow into the circulation.\”

       The result — a potentially
needle free treatment for diabetes, and possibly a whole host of other
illnesses. Dr. Harvey Berger,Ariad Pharmaceuticals\’ CEO, suggested the
technology could have broader application such as managing chronic pain,
with the cells engineered to produce and release endorphins on cue rather
than insulin. Another possibility would be for using the technique to
treat conditions which required regular, periodic release of some protein,
such as growth hormone.

       Ariad Pharmaceuticals hopes
to begin human trials of this fascinating technology by 2003.

References:

Researchers
find new way to deliver insulin in lab studies. Associated Press,
February 4, 2000.

Gene therapy
may replace insulin shots in diabetics. Reuters, February 4, 2000.

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Cloning pioneers consider creating sheep with cystic fibrosis

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The team that created a firestorm
of controversy after successfully cloning Dolly the sheep is considering
helping a group of researchers at Edinburgh create a genetically engineered
sheep that has human cystic fibrosis.

Cystic fibrosis is a genetic
disease caused when a child receives a specific faulty gene from both
parents. Cystic fibrosis causes a variety of health problems, which tend
to vary from individual to individual, but is marked by severe respiratory
problems. People with cystic fibrosis have mucus secretions that are much
thicker and stickier than normal human mucus secretions, and the thick
secretions can cause severe respiratory problems from difficulty breathing
to higher risk of infection. A lot of advances have been made in extending
the life span of people with cystic fibrosis, but even today only 50%
of those with the disease will survive into their 30s (many of those patients
have to take up to 40 pills a day to prolong their lives).

Scientists have already managed
to create smaller animals, such as mice and rats, with cystic fibrosis,
but nobody has attempted to do so with larger animals. Sheep are a particularly
good candidate for cystic fibrosis research because they have lungs similar
to human lungs, and they tend to suffer from similar respiratory ailments.
The research under consideration would create at least two sheep with
the defective gene and then require breeding those sheep to produce a
sheep with a copy of the defective gene from each parent.

The Edinburgh researchers already
have a gene therapy treatment for cystic fibrosis that has received approval
in Great Britain for testing in normal sheep, and if those experiments
are successful an experiment in sheep that have the human disease would
be the next logical step.

References:

Dolly
team to create sheep with cystic fibrosis. The Times (UK), February
8, 2000.

What is cystic
fibrosis?. Michigan State University fact sheet.

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Researchers use gene therapy to restore rat liver functions

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    Researchers have used genetically
modified liver cells to grow in the laboratory and successfully transplanted
the lab-grown cells into rats.

    The cells, called hepatocytes,
are generally difficult to grow under laboratory conditions. Transplanting
of such cells has been done in humans before, but with limited success
because of the difficulty in isolating enough hepatocytes.

    The technique described in
the Science articles inserts a cancer gene that forces the liver cells
to reproduce quickly. Then when enough of the liver cells are created,
researchers treated the cells with an enzyme that gets rid of the cancer
gene and halts the growth of the cells.

    The researchers then injected
the liver cells into rats who had 90 percent of their liver surgically
removed. Sixty percent of the rats receiving the genetically modified
liver cells survived to live normal lives, while all animals in a control
group that didn\’t receive the cells died within three days.

Reference:

Researchers
experiment with genetic liver therapies. The Associated Press, February
18, 2000.

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PETA Protests George W. Bush

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People for the Ethical Treatment
of Animals didn\’t make any friends with Republican presidential candidate
George W. Bush during the South Carolina primary. PETA decided to protest
Bush after the presidential candidate had just finished a pancakes-and-bacon
breakfast.

A PETA activist dumped a truckload
of dried manure at the doorstep of the restaurant where Bush had just
eaten. The activist then abandoned the dump truck used to deposit the
manure (with a requisite sign saying \”Meat Stinks\”) so that it blocked
Bush\’s campaign bus. According to an Associated Press report on the incident,
\”Police moved in, grabbed the man, and as they dragged him away he yelled:
\”Meat is murder! Pork is death!\”

Bush, who was taping a television
interview at the time, joked, \”I sure am glad I had my bacon for breakfast.\”

Reference:

\”PETA protests Bush breakfast stop.\” Associated Press, February 19, 2000.

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Activists Fail — Barely — To Pass Circus Ban In Seattle

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    In a preview to a battle that
is likely to get far more intense through the rest of this decade, a ban
on circus animals on city property barely failed to pass the Seattle City
Council. The proposed ordinance failed on a 5-4 vote after heavy lobbying
by animal rights activists and circus officials.

    Although there are a few places
around the country that already have local bans on circuses, Seattle would
have been the first major city in the United States to pass such a ban.

    Those who support the ban argued
that keeping animals in circuses is inherently cruel. As Diane Venberg,
an organizer for the Progressive Animal Welfare Society put the animal
rights case, \”Bottom line, there\’s no way to provide a natural habitat
for animals in a circus.\”

    Anti-circus activist Claudine
Erlandson put a melodramatic touch on after the vote saying, \”All Seattle
is crying. That\’s not rain outside it\’s tears.\” But Erlandson and the
others do not intend to give up.

    \”We\’re going to re-group and
perhaps put the measure on the general election ballot,\” said activist
Simon Chaltowitz.

    Whether or not PAWS or any
of the other anti-circus activists have the financial wherewithal to do
so is debatable. Both sides of the issue spent thousands of dollars on
ads before the vote and at least one activist expressed skepticism about
whether it was realistic to push for a ballot initiative so soon.

    Especially considering that
Ringling Bros. and other circuses targeted by the activists seem prepared
to fight back.

    Without a ballot issue, though,
it\’s hard to tell how much legs the circus ban movement will have in the
United States. Getting a few animal rights-oriented individuals on elected
to the City Council is one thing, especially given typically low voter
turnouts in local elections in the United States, while getting voters
to agree with the animal rights position on a ballot initiative is another
thing, as activists have found in recent years with failed iniativies
such as their effort to require warning tags on fur in Beverly Hills.

    Personally, I doubt there is
any great desire among the electorate to ban circus animals. As Ringling
Bros. spokeswoman Joan Glavin underscored, the reason Ringling Bros. is
successful is precisely because so many people want to see exotic animal
acts.

    \”As long as they [circus patrons]
continue to come by the millions, we will have animals. And we will continue
to protect the rights of people to see them.\”

References:

Animal advocates regroup after Seattle defeats circus animal ban. The
Associated Press, February 15, 2000.

Seattle City Council defeats exotic-animal ban; activists to regroup.
John Zebrowski, Seattle Times, Feb. 15, 2000.

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