Diacrin + 100 % - 500 Beiträge pro Seite

[Kostos Jünger]

Warum hat Diacrin sich heute verdoppelt?
Und 56,25% plus an der Nasdaq?

Nasdaq +56,25%
Frankfurt +98,63%
München +105,48%
Berlin +104,38%

Da müsste es doch irgendeine Meldung geben, habe aber bis
jetzt nichts gefunden.

Wer weiß mehr?

[Kostos Jünger]

Einen Grund für den plötzlichen Wiederanstieg habe ich noch nicht gefunden,
angeblich soll es in absehbarer Zeit News geben.

In der Zwischenzeit hier mal ein interessanter Artikel zum
Thema Zelltransplantation, in dem Diacrin mehrfach erwähnt wird.

Quelle: http://www.jsonline.com/alive/news/may01/pig06050501.asp


This little piggy might save your life

Process of cloning pigs for transplants offers hope, questions

By JOHN FAUBER
of the Journal Sentinel staff

Last Updated: May 5, 2001

DeForest - In a nursery pen at a secret location not far from here, a dozen piglets scamper
around, cute and oblivious to their status as pioneers in modern medicine.

Not only are these little porkers some of the world`s first cloned pigs, but they also have a human
gene inserted in their DNA, making them transgenic.

Other than sheer madness, why would scientists want to add human genes to a pig?

Because someday, one of the 100 million or so pigs slaughtered in this country may save your life.

Researchers here at Infigen Inc. are trying to genetically alter and clone pigs to produce organs
that will not result in massive organ rejection when transplanted into humans.

Just how many lives are saved, extended or improved may well depend on the success of the
experiments taking place at Infigen and other research sites around the country, including the
University of Wisconsin-Madison.

In the nextfive years, porcine hearts, kidneys, livers and even brain cells probably will be
transplanted into sick, dying or injured people in hopes of giving them a new lease on life, some
scientists say.

The official term for when animal organs or cells are transplanted into a human is "xenotransplantation." Some scientists think that millions of
people could someday benefit, and that xenotransplantation could act as a bridge to the kind of human tissue advancements that stem cell
research may yield.

But there are obstacles and risks.

First, more work is needed to genetically alter and clone pigs to produce organs that will not be rapidly rejected by their human hosts,
although many scientists now believe that day is near.

Beyond that, there is unknown risk lurking.

What if a hidden virus or other unknown infectious agent in pigs attacked the person who received a pig organ? Worse yet, what if that
person spread the virus to large numbers of other people before scientists realized it was deadly to humans?

It is believed that HIV, for example, jumped from chimpanzees to humans sometime during the first half of the 20th century, eventually
leading to the worldwide AIDS epidemic.

Infections from animals

In their cells, nearly all pigs carry porcine endogenous retrovirus (PERV), a pathogen that has shown the ability to infect human cells, at least
in a laboratory dish. The virus does not make pigs ill; its effect on humans remains unknown. But in a 1999 study of 160 people who had
been exposed to living pig cells, none showed any evidence of being infected by PERV.

Still, PERV is just one known virus; other animal pathogens may not have been identified yet. For example, scientists already know that pigs
play a unique role in the spread of flu viruses. Most of the viruses originate in birds, then infect animals such as pigs, which can recombine
the flu virus DNA in novel ways before spreading it to humans.

"We don`t want to unleash a pandemic on the world," said David Cooper, a professor of surgery and immunology at Harvard Medical
School and president of the International Xenotransplantation Association.

But the pig already may be out of the pen.

Already, more than 200 experiments involving pig cells or organs have taken place.

In one of the early cases, Rebecca Draeger, then a 17-year-old Iron Ridge resident, had her blood infused through pig livers at the
University of Wisconsin Hospital and Clinics in Madison to keep her alive for more than a day until a human liver could be transplanted.

At the time, she was less than 24 hours away from brain death, according to her doctor. A catheter was inserted into the femoral vein in her
leg, near her groin. Her blood was pumped out into a mechanical oxygenator, a blood warmer and then into the main vein of the pig liver.

"The liver was in a sterile container at her bedside," said UW transplant surgeon Tony D`Alessandro.

As the blood circulated through the pig`s liver, toxins and bile were removed, and the blood was returned through the jugular vein in her
neck. When one liver reached its limit, a second was used.

Today, Rebecca, 22, is married and doing fine; she gave birth to a son about a year ago.

Draeger`s operation was a stopgap measure, not an actual transplantation. However, much more permanent and bold experiments have
been devised and tested in the last several years.

Brain cells substitute

In September 1999, Maribeth Cook had 30 million brain cells from a pig fetus injected into her brain.

Cook, 40, of Saratoga Springs, N.Y., had suffered a debilitating stroke five years earlier, and she and her doctors hoped the neural cells
from the pig fetus would take over the functions of her neural cells that died as the result of her stroke.

Less than two years after the operation, Cook said she has seen noticeable improvement. Her speech and walking have improved, she said.

But more important: "My cognitive thinking is better," she said. "I`m thinking clear, and I`m reading."

Before the operation, she said, she remembered virtually nothing when reading.

Cook is one of five stroke victims and 10 Parkinson`s disease sufferers to have neural cells from pigs injected into their brains in clinical trials
being conducted by Diacrin Inc., a biotech company in Charlestown, Mass.

The results from those trials have been mixed.

The stroke trial was stopped after two of the patients suffered seizures, even though one of them later reported a significant improvement in
her condition and the cessation of seizures.

In the Parkinson`s trial, there was an average 28% improvement in the condition of the 10 patients. It is believed the pig neural cells can help
Parkinson`s patients produce dopamine, a brain chemical they lack.

However, there also was a 21% improvement in a group of eight "placebo" patients who had small holes drilled in their heads - "just a little
divot," according to a Diacrin official - but who received no pig brain cells.

Over the next three months, Diacrin researchers will analyze the data and decide their next step, said Doug Jacoby, the company`s director
of research.

For the rest of their lives, some of the patients also will have to be tested for signs of the porcine endogenous retrovirus.

In the meantime, the company last month started a trial involving the injection of pig fetal nerve cells into the spinal cords of six paraplegics
and quadriplegics.

Animal experiments suggest that such a procedure may help repair the spinal cord and restore some function. However, the spinal cord
study is a trial designed primarily to test the safety of the procedure.

Other researchers have transplanted or scheduled trials involving the transplantation of pig pancreas cells into diabetics in hopes of helping
them produce their own insulin. At one time, insulin used by humans to control their disease came from pigs.

Need for organs

One of the big reasons why xenotransplantation may become a necessary therapy is the vast numbers of people in need of life-saving
organs.

Last year, 22,827 people donated organs, but more than 75,000 people needed an organ. About 15 people die every day in the United
States while waiting on an organ donation list.

Pig organs are the most likely source because anatomically they are similar to human organs, and there is virtually an unlimited supply. Pigs
produce large litters in a little more than three months, and the animals mature quickly.

Non-human primates such as chimpanzees and baboons are not likely to provide organs for people because they take longer to raise, and
some are considered endangered. As close relatives to humans, they also harbor viruses that could easily be transmitted to people.

The Food and Drug Administration - with input from the National Institutes of Health and the Centers for Disease Control and Prevention -
has regulatory authority over xenotransplantation experiments. Former Gov. Tommy G. Thompson, as secretary of the Department of
Health and Human Services, oversees those agencies.

Thompson now has an 18-member group, the Secretary`s Advisory Committee on Xenotransplantation, helping him with that responsibility.
The committee had its first meeting in February.

Thompson said xenotransplantation offers "tantalizing" possibilities and the potential to provide a much greater supply of organs and tissues.
But there are concerns, especially the risk of transmission of infectious diseases from animals to humans, he said.

"As high as some of our hopes are for xenotransplantation, this is an area where care and thoroughness are especially important," he said in
a statement to the Journal Sentinel.

Organs made to order

Permanent transplantation of whole animal organs into humans could be three to five years away, said Cooper, of Harvard Medical School
and co-author of "Xeno: The Promise of Transplanting Animal Organs into Humans."

In fact, xenotransplantation could become one of the greatest medical advances of the 21st century, he said.

In his book, Cooper, a longtime heart and lung transplant surgeon, describes a scenario that he says could be repeated daily at "donor
centers" around the country. Surgeons arrive, scrub, enter sterile rooms and begin removing organs to order. Those organs quickly are
perfused with a cold saline solution, put on ice and shipped by plane.

The donor centers would not be hospitals, but rather "veterinary institutions" on farms where special pigs would be bred and raised by the
thousands.

"The potential benefits are absolutely immense, and it could prove to be the next great medical revolution," he writes.

However, science still needs to address some issues.

Even organs from humans are often quickly rejected when transplanted into other people. Organs and tissue from other people are viewed
as foreign by the body`s immune system, which begins to attack the organs as soon as they are transplanted.

In human-to-human organ transplants, doctors are able to avoid part of the problem by selecting organs from donors who are a good match
to the recipient, such as those from someone with the same blood type, and by using immune-suppressing drugs, which must be taken for
the rest of the recipient`s life.

But there is a violent, hyperacute rejection that takes place when animal organs are transplanted into people.

"It is a dramatic immune attack," Cooper said.

To avoid hyperacute rejection, researchers are trying to genetically alter pigs, both by adding certain human genes and by knocking out pig
genes to make the organs appear more human-like to the body`s immune system.

Experiments abound

Infigen already has succeeded in adding a human gene to the DNA of pigs and then cloning those pigs, said Michael Bishop, president of
Infigen. However, the first gene that was added was done just to prove that the concept worked. It was not a gene that would make pig
organs more suitable for human transplantation.

Other researchers have been able to add another human gene to pig DNA as another possible means of preventing hyperacute rejection
problems.

Infigen also has been able to clone embryos with a "knockout" or inactivated pig gene, a development researchers hope will lead to organs
that won`t be rapidly rejected by humans. Piglets with the knockout gene are expected to be born in July, Bishop said.

So far, more than 40 cloned pigs, including several with the human gene added, have been born at Infigen, Bishop said.

"We`ve got so good at cloning pigs, we had to quit," Bishop said. "We had so many of them around."

More genetic tampering probably will be needed to prevent other organ rejection problems.

While that research is going on, better immune-suppressing drugs are being developed.

Last year, UW researchers received a $1.3 million grant to test drugs designed to prevent rejection of pig kidneys transplanted into
baboons. Before pig organs are transplanted into humans, they will be tested in non-human primates such as baboons.

Researchers at other universities also are testing immune-suppressing drugs that can be used in xenotransplantation.

Hans Sollinger, head of the UW organ transplant program, said much work still needs to be done and scientists need to be careful not to
give false hope.

Nevertheless, he said, xenotransplantation "looks like the only promise we have" in addressing the imbalance between the number of human
organs available and the number of people needing them - at least until, or unless, stem cell research opens up new opportunities to use
human tissue.

"Ultimately, we will be using animal organs to transplant to humans," Sollinger said. "It will change the face of medicine."


Appeared in the Milwaukee Journal Sentinel on May 6, 2001.