Tag: Pigs

Transplanting animal cells into human beings produces benefits today

Keeping with the Xenotransplantation theme, there have been a number of stories recently about real world applications
for transplanting animal cells into human beings as well as transplanting
genetically altered human cells into human beings.

  • In late May, the U.S. Food and Drug Administration approved a new
    skin graft product called Apligraf intended to be used initially in
    the treatment of venous skin ulcers. Apligraf is composed of human skin
    cells combined with collagen cells taken from cattle. The human cells
    come from the foreskins of newly circumcised infants.

    Venous skin ulcers affect thousands
    of Americans each year and require multiple surgeries to correct. Apligraf
    will speed the healing and recovery time after surgery. The product
    is currently undergoing clinical trials to discern its effectiveness
    in treating burns, diabetic ulcers and eventually bed sores.

  • At the end of July, Imutran, one of the leading companies doing xenotransplantation
    work, announced it would begin using pig livers to act as dialysis machines
    for human beings.

    “What we are thinking of doing
    is using the liver as a temporary support, outside the body, as a sort
    of dialysis machine for patients in liver failure to allow the doctors
    to buy time until a human organ becomes available for transplantation,”
    Dr. Corrine Savill, Imutran’s CEO, told BBC radio.

    About 50,000 people in Europe alone
    are waiting for transplants, with that number growing at 15 percent
    a year according to a Reuters News Service report.

  • In May a 20-year-old college student had a historic operation after
    his heart was removed from his body and fixed using animal tissue.

    Guy Altmann, a Texas A&M student,
    had a malignant tumor the size of a lemon lodged in his mitral valve.
    During the six-hour operation, his heart was stopped, removed and the
    tumor cut away. The mitral valve was rebuilt using heart tissue from
    a cow.

    “I feel a lot better than
    when I cam in,” Altmann told the Associated Press.

  • And what about the fear expressed by animal rights activists that
    xenotransplantation could lead to some outbreak of a previously unknown
    disease? An August report in the New Scientist magazine suggests
    that there have been no signs of transmission of such diseases in patients
    who have received cells from pigs for pancreatic disorders and Parkinson’s
    disease.

    “The findings, based on screening
    samples from patients exposed to pig tissue, provide the first compelling
    evidence that dormant pig viruses do not spread to humans, causing new
    and incurable diseases,” the magazine reported.

    More research will need to be done,
    of course, but so far the worst fears of those opposed to xenotransplantation
    and genetic engineering are proving unfounded.

Sources:

Drug that helps heal skin wounds wins FDA approval. Reuters News Service, May 26, 1998.

Company plans to use pig livers as human dialysis machines. Patricia Reaney, Reuters News Service, July 30, 1998.

Man has rare surgery: his heart is removed, fixed with animal tissue, put back in his chest. Mark Babineck, Associated Press, May 22, 1998.

Transfer of animal cells to humans shows promise. Reuters News Service, August 5, 1998.

Cloned animal cells may lead to Parkinson's treatment

Parkinson’s disease is a brain disorder
that causes sufferers to experience tremors and erratic movements. Experiments
with cloned cells in animals may lead to a breakthrough in treatment of
the disease.

Researchers at the University of
Colorado successfully transplanted cells |cloned| from bovine brain cells
into the brains of rats that suffered from Parkinson’s-like symptoms.
The cloned bovine cells were effective in treating the rats’ symptoms.

“What we found was that the
bovine fetal dopamine cells were just as good as bovine embryo cells from
an animal that was not cloned, ” said Dr. Curt Freed of the University
of Colorado.

Freed is not the only researcher
exploring the use of cloned animal cells for such treatments. Researchers
at Emory University will transplant pig cells into human beings later
this year.

Source:

Rhonda Rowland “Cloned animal cells may help treat Parkinson’s disease”
Cable News Network April 27, 1998.

Researchers Transplant Genetically Modified Heart Cells from Mice into Pigs

Even when someone survives a heart
attack, significant amounts of muscle tissue die, damaging the heart. The
Associated Press recently reported on a technology which someday may allow
such tissue to be regrown.

The March 17 story described experiments
conducted at the Louisiana State University Medical Center by Dr. William
C. Claycomb. Claycomb sucessfully transferred genetically modified heart
cells from mice into the damaged heart of a pig, where the cells survived
and acted like normal heart muscle, although it is unclear if the mouse
cells actually assisted in the working of the pig heart.

Although any use in humans for
this sort of technology is years, if not decades away, the importance of
this experiment is demonstrating that it is at least possible.

“It is a very important advance,”
said Dr. Kenneth R. Chien, a professor of medicine at the University of
California, San Diego. “The work challenges the dogma that it is
not possible to create a cell line that displays the unique features of
an intact heart.”

Hog Intestines Used to Rebuild Human Knees

James McDonald can walk without
the aid of crutches again thanks to a promising new technology which uses
the intestines of hogs to strengthen weakened human knees. A March 9 Associated
Press story reported that McDonald was the first human being to receive the
still-experimental implant of small-intestinal submucos (SIS), derived
from the small intestines of hogs, into his knee. The intestine replaces
the kneeÂ’s anterior cruciate ligament (ACL).

In animal tests, SIS has shown
an ability to stimulate healing and growth of new blood vessels in damaged
tissue. “ItÂ’s exciting because it seems to have the capacity
to stimulate the bodyÂ’s healing response and to modify itself to
whatever environment itÂ’s being used in,” said Dr. Robert Hunter, who performed the surgery on McDonald.

McDonald and 11 other individuals
are being given the implants in Food and Drug Administration-approved
clinical trials to test their safety and efficacy in human beings. If
the trial prove successful, more comprehensive trials are likely and SIS
could have uses beyond mere knee replacement, including applications in
repairing tendons and ligaments and perhaps even replacing human arteries.

SIS avoids the thorny problem of
potential cross-species disease contamination by using a process which
ensures no individual hog cells are transferred to human beings. Animal rights activists have argued that the risk of spreading diseases through such xenotransplantation is unacceptable.