|Growing your very own cell garden
Did you ever hear anything about stem cells?
Wouldn't it be great to grow new liver tissue in case
your old one was too heavily damaged ?.
It certainly would but, sorry, millions of years of biological
evolution have not been enough to develop that ability. On the other hand,
a few thousand years of cultural and technological evolution added on top
could be enough to master that trick.
Bone marrow stem cells do
the trick in rats (May 13, 1999)
Cell Research Tops '99 Science (12/16/99)
Cell Transplant in Mice Hailed ( 12/27/99)
Diabetes Reversed in
Mice ( 02/29/00)
Research Spurs Debate (04/26/00)
Mouse Brain Now
Self Repairing (06/21/00)
Heart Group OKs Stem-Cell
Research (June 26, 2000)
Introduction. Jan 27, 1999
We are not talking about developing
artificial livers. This time scientists are thinking about the possibility
of growing specialized cells such as those found in liver tissue from non-specialized
cells (stem cells) in a process somewhat similar to the one taking place
during the development of embryos. These "master cells" are indeed at the
root of human life. They are called embryonic stem cells and are
microscopic dots that grow inside weeks-old embryos before morphing into
any of the 210 types of cells that make up a human body.
Finding and controlling embryonic
stem cells has been a Holy Grail of science. Understanding how they develop
could prevent birth defects. These cells could grow huge tissue banks for
safer drug testing. They might even grow replacement body parts. Livers
or hearts cannot regenerate. But imagine doctors one day repairing heart-attack
damage with a simple injection of cells to grow new heart tissue or curing
diabetes by injecting insulin-producing cells.
Excitement in the scientific community
was understandably great in the fall of 1998 when researchers in Wisconsin
and Maryland culled some of these mysterious cells and grew large supplies
of them in laboratories.
Sound like science fiction? Look to
Johns Hopkins University, where Dr. John Gearhart already has used the
technology to grow fledgling human brain cells in his lab.
BUT. So far, scientists thought
that only stem cells from embryos could be used in this new frontier of
research on man-made cellular regeneration. The ethical implications were
obvious, some ethicists showed concerns, and abortion opponents declared
stem cell technology immoral and wanted it banned. On the other hand powerful
patients' groups were demanding the research.
THE (most recent) GOOD
NEWS IS that Science is progressing so rapidly in this new area
of research that it might circumvent the ethical dilemma.
In January 1999 researchers have announced
that adult mice harbor certain ``mature stem cells'' designed to replenish
one tissue that can sometimes be recoded to grow other tissues. If humans
have the same capacity, stem cells from embryos might not be needed. We
could after all take some of our own stem-like cells and convince them
to grow into our most beloved tissue. We would be growing our very own
This headline was taken in part from:
Promise of 'Master Cell' Research
By LAURAN NEERGAARD=
AP Medical Writer=
Bone marrow stem cells do the trick in rats Friday, May 13 1999.
03:06 PM ET 05/13/99
Cell Used To Make New Liver Tissue
By PAUL RECER AP Science Writer
WASHINGTON (AP) _ Special bone marrow cells have been
convert into basic liver tissue, raising the possibility
of one day using a patient's own marrow to repair failing livers, researchers
In laboratory rat studies at the University of Pittsburgh Medical Center,
researchers found in bone marrow a master, or stem, cell that under special
conditions will convert itself into functioning liver tissue cells.
Bryon Petersen, lead author of the study to be published Friday in the
journal Science, said the work is the first step toward learning how to
rescue failing livers using the body's own stem cells.
Petersen said that in new experiments he already has shown that injecting
the special marrow cells into rats causes the animals to form new liver
Although the work only has been demonstrated in laboratory animals, Petersen
said other studies strongly suggest humans also have bone marrow cells
that will convert into liver cells.
``What we have learned from the rat, we should be able to extrapolate to
the humans,'' said Petersen. But he cautioned that perfecting the technique
for humans may take a decade.
Dr. John M. Vierling, liver specialist at Cedars-Siani Medical Center in
Los Angeles and chairman of the board of the American Liver Foundation,
said the research raises ``very exciting'' possibilities for reviving dying
Vierling said that other researchers have been trying with little success
to find in the liver stem cells that could make new tissue. If the cells
can be isolated from the bone marrow and cultured, he said, it raises the
ossibility of finding a virtually unlimited supply of key liver cells.
``The ability to take something from scratch, so to speak, and grow it
up in the quantity that you need would be extraordinary,'' Vierling said.
Dr. Mark F. Pittenger, a researcher at Osiris Therapeutics in Baltimore
who recently found in bone marrow the stem cells for bone, cartilage and
fat, called Petersen's ``a significant step forward.''
``It bodes well for our learning how to regenerate organs,'' said Pittenger.
``Liver disease is a very serious problem.''
The American Liver Foundation says about 26,000 Americans die annually
from liver disease. About 5 million in the U.S. are infected with hepatitis
B or C, virus diseases that are a major cause of liver failure.
Petersen said that his research investigated how some people
with liver failures are able to grow new liver
tissue. Some patients with failing livers recover after the organ spontaneously
grows new cells, he said.
The liver often can generate new hepatocytes, or a type of healthy liver
cells, after an injury or disease. But Petersen said that some patients
who do not make new hepatocytes still end up growing new liver tissue and
Just how this happens, said Petersen, long has been a mystery.
Researchers suspected some special cells in the
bone marrow somehow were prompted to start making new cells for the distressed
Peterson said research using the lab rats proves the bone marrow is the
source of these new liver cells.
In the study, Petersen and his colleagues destroyed the bone marrow of
female rats and replaced it with marrow from male rats. This meant that
the female rats had bone marrow that carried the male Y chromosome, which
could be used to identify cells. The scientists treated the female rats
with a chemical that prevented their livers from regenerating and then
livers, mimicking an injury. Two weeks later, the
livers were removed and the researchers found they contained new liver
cells that carried the Y hromosome marker. This meant that cells from the
bone marrow had gone to the failing livers and started the regeneration
``This suggests that there is a stem cell in the adult bone marrow that
is capable of becoming anything if you give it the right signal,'' said
Petersen. ``I have been able to show that there is a cell in the bone marrow
for the liver.''
He said there is preliminary work in his lab that shows the bone marrow
also has a stem cell that converts into pancreatic cells.
Petersen said that once researchers learn to isolate stem cells from the
bone marrow, switch them into liver cells, and then grow them into large
quantities, it may be possible to rescue failing livers with simple injections.
Vierling cautioned, however, that the technique would not totally replace
the need for liver transplants.
Cell Research Tops '99 Science 02:01 PM ET 12/16/99
Stem Cell Research Tops '99 Science
By PAUL RECER=
AP Science Writer=
WASHINGTON (AP) _ In a rapid surge of discovery, researchers in
1999 began learning how to direct the transformation
of stem cells into new body parts, a finding that may dramatically
change medicine and extend life.
The editors of Science have selected the new stem cell research as
the ``Breakthrough of the Year'' for 1999. A report appearing Friday
in the journal said the new technology ``raises hopes of dazzling
But the research also created a troubling ethical debate that was
heard throughout the year in the White House, in Congress and in
laboratories coast to coast.
Embryonic stem cells are the ancestral cells that give rise to all
of the tissues and organs in the body. Researchers believe that such
cells, taken from human embryos or fetuses, could be directed to grow replacements
for ailing hearts, livers or other organs.
Use of embryonic stem cells has been denounced by some members
of Congress and by antiabortion groups.
President Clinton asked a commission to evaluate the ethics of using
stem cells in federally funded research. The report supported the
National Institutes of Health director Dr. Harold Varmus also supported
stem cell research and proposed guidelines that would permit government
funding, but only if the embryonic stem cells used were developed
by private funds. The work was to be monitored by a special oversight commission.
Researchers have also found that some stem cells taken from adult tissue
could be converted into other types of cells _ brain cells becoming blood
cells, or bone marrow becoming liver.
Science editor Floyd E. Bloom said in an editorial about stem cells: ``Although
much remains to be done to convert today's results into tomorrow's treatments
and tools, the likelihood of success seems high.''
Runner-up for breakthrough of the year were the huge advances in genomics,
the science of deciphering the basic genetic pattern of life. The complete
gene equence for three microbes was completed in 1999, and a third of the
base pairs in human DNA, along with one complete chromosome, number 22.
A rough draft of the entire human genome is expected by March.
The other research advances selected and listed by Science in no particular
_Cooling fermions, one of the two basic particles of matter, to near absolute
zero to create a state of matter in which atoms act like waves instead
of individual particles.
_Resolving the structure of the ribosome, a sort of protein-making factory
inside a cell.
_Finding more planets beyond the solar system. Astronomers now have evidence
of about 30 planets orbiting distant suns and have captured what may be
a view of one planet orbiting across the face of a star.
_Researchers have found new molecules in the brain that play a role in
creating memories and learning.
_Astronomers found new evidence that the universe is flat. This supports
the Big Bang theory by establishing a precise balance between matter and
_Researchers developed photonic crystals, components that manipulate light
waves just as semiconductors manipulate electrical current. Photonic crystals
could lead to new types of computers and communication circuits.
_Cell fossils were discovered that push the known existence of complex
life back to 2.7 billion years, a billion years earlier than previously
_Gamma ray bursts, cosmic eruptions that put out more energy in seconds
than the sun does in 10 billion years, were linked to the birth of black
holes. This provides one answer to a mystery that has persisted for 30
For the ``blunder of the year,'' Science selected the National Aeronautics
and Space Administration's failed Mars Climate Orbiter. The $87 million
Mars probe was lost when NASA engineers used pound-seconds, an English
system measure, instead of Newton-seconds, a metric measure, to guide the
craft's rocket firings.
For ``Breakdown of the Year,'' Science selected the decision by the Kansas
State Board of Education to drop evolution from statewide science teaching
standards. The decision is considered a triumph for creationists who believe,
along with 35 percent of all American adults, that the Biblical account
of creation is literally
Cell Transplant in Mice Hailed 06:54 PM ET 12/27/99
Stem Cell Transplant in Mice Hailed
By RANDOLPH E. SCHMID=
Associated Press Writer=
WASHINGTON (AP) _ Researchers have successfully transplanted
cells that eventually develop into sperm, giving
new hope of
fatherhood to young males who undergo cancer treatments
their reproductive potential.
A team of researchers led by Ralph L. Brinster of the University
of Pennsylvania School of Veterinary Medicine,
was able to
transplant the stem cells from one type of mouse
into another. The
cells then developed into sperm cells, carrying
the traits of the
The findings, developed in a study of whether fertility can be
restored in infertile males, are reported in Tuesday's
issue of the
journal Nature Medicine.
While the work was done only in mice, it could have major
implications for some young human cancer victims,
Howard J. Cooke
of Western General Hospital in Edinburgh, Scotland,
reports in an
accompanying news article.
Because some cancer treatments can cause mutations in developing
and mature sperm cells, men undergoing these treatments
sperm removed and frozen for later use.
This cannot be done for boys who have not yet gone through
puberty since they have no mature sperm cells.
Cooke and colleague Philippa K. T. Saunders say that Brinster's
work indicates that if immature stem cells can
after transplantation, they can be frozen and reintroduced
donor after completion of cancer treatment.
``It certainly looks very promising, in particular the fact that
they were able to get the new sperm-generating
cells into testes
that didn't have these sperm generating cells in
them for most of
their lives,'' said Evelio Perez-Albuerne, an attending
in the Hematology-Oncology Department at the Children's
Medical Center in Washington.
``This is also exciting because this was one of the first times
people have actually talked about there being offspring,
to just being sperm cells under a microscope,''
Perez-Albuerne, who was not involved in the research.
Frozen preservation ``of testicular stem cells and
post-treatment reintroduction, could protect germ
potentially (mutation causing) cancer treatments
against infertility,'' Cooke and Saunders concluded.
However, they caution, care needs to be taken to avoid
reintroduction of cancer cells into the patient
in this process.
They also noted that the ability to separate, preserve and
reintroduce stem cells raises the possibility of
using gene therapy
to correct genetic problems.
``Ethical problems with this approach abound,'' they said.
Diabetes Reversed in Mice
10:02 AM ET 02/29/00
NEW YORK (AP) _ Scientists have reversed diabetes in mice by
generating insulin-producing cells in a laboratory and
transplanting them into the animals, an indication of
so-called stem cells might be.
The mice had a version of Type 1 diabetes, which occurs when the
body mistakenly destroys insulin-producing cells in the
People with this disease must inject themselves with
Patients have been treated with transplants of islets, the
insulin factories of the pancreas. But the success rate
low, apparently in part because it's hard to get enough
a cadaver's pancreas.
The new work suggests a way to overcome that problem: prodding
immature stem cells from the pancreas to make abundant
of islets in the laboratory.
The mouse study by researchers at the University of Florida
College of Medicine and elsewhere is reported in the
March issue of
the journal Nature Medicine.
In one set of experiments, eight diabetic mice received the
lab-generated islets and then were weaned from insulin
over a few days. Within a week after injections stopped,
showed a decline in blood-sugar levels. They remained
without insulin injections until they were killed for
of the implant, a period of up to 55 days from implantation.
Master Cell' Research Spurs Debate
04:26 PM ET 04/26/00
By LAURAN NEERGAARD=
AP Medical Writer=
WASHINGTON (AP) _ Paralyzed ``Superman'' star Christopher Reeve
urged Congress on Wednesday to let federally funded research
master cells from discarded human embryos, questioning
lawmakers would rather throw away the embryos than use
experiments that Reeve believes could one day help him
``Is it more ethical for a woman to donate unused embryos that
will never become human beings, or to let them be tossed
away as so
much garbage when they could help save thousands of lives?''
asked a Senate subcommittee hearing.
But it's a controversial issue: Reeve's comments came after a
Kansas senator compared the research to Nazism.
``Federally funded human embryonic stem cell research is
illegal, is immoral, and it's unnecessary,'' Sen. Sam
R-Kan., told the Senate health appropriations subcommittee.
At issue are embryonic stem cells, the master cells that in very
early embryos generate all the other tissues of the body.
generating huge excitement among scientists because if
could learn how to control stem cells, they possibly
diseases like Alzheimer's, diabetes, or Parkinson's,
or even repair
broken spinal cords like Reeve's.
Already, private companies are culling stem cells from embryos
donated by women who have some left over after fertility
treatments. But the federal government has not funded
into embryonic stem cells because of a congressional
ban on any
research that destroys human embryos _ and taking stem
embryos does destroy them.
The National Institutes of Health has proposed a way around the
ban. Draft guidelines now under review would let the
NIH fund some
embryonic stem cell research as long as the science is
only on cells already derived by private companies, so
NIH-funded scientists don't touch the actual embryos.
Proposed legislation would go farther, letting women agree to
donate their leftover embryos to federally funded researchers.
approaches face opposition by at least 70 members of
``The embryos to be used here are discarded. If not used for the
research, they will not be used at all,'' Sen. Arlen
R-Penn., who co-authored the legislation, explained Wednesday.
Thus, ``no human life is to be taken.''
``This sounds ... like what happened in World War II,''
Brownback countered, comparing embryo destruction for
Nazi contentions that ``these people are going to be
not experiment on them.''
Yet the embryos in question are no bigger than the period at the
end of a sentence.
``To equate that with individuals Nazis experimented on is
stretching the meaning of humanness,'' said Sen. Tom
D-Iowa, who co-authored Specter's legislation.
Because embryonic stem cells could save lives, ``our position is
just as moral as your position,'' Harkin added.
Brownback, however, noted that some stem cells do roam inside
adults' bodies, and he urged scientists to use them as
Scientists are trying that, too. But two NIH scientists told
senators that adult stem cells are far more scarce, and
grow as well, as those found in embryos. Thus many researchers
believe trying both approaches is crucial.
If government scientists cannot pursue embryonic stem cells, ``I
think this would be tying one hand behind our back,''
Allen Spiegel, NIH's diabetes chief.
Mouse Brain Now Self Repairing
04:00 PM ET 06/21/00
By MATTHEW FORDAHL=
AP Science Writer=
Scientists have managed to make new neurons grow in an area of
the brain once thought to lack the ability to regenerate,
hopes of developing new ways of treating neurological
The researchers induced the creation of the neurons in the
neocortex of lab mice by triggering stem cells, or precursor
that already exist in the brain.
Other research has shown that under specific conditions,
transplanted stem cells can form new neurons. The new
indicates that transplantation may not be needed.
Instead, a combination of molecular signals can accomplish the
same thing, said Dr. Jeffrey Macklis, a neuroscience
Harvard Medical School and Children's Hospital who led
It was published in Thursday's issue of the journal Nature.
The researchers were encouraged to find that the new cells
showed evidence that they were incorporated into the
circuitry. The cells migrated to areas populated by the
neurons and sprouted axons, or connections, into the
Macklis and fellow researchers Sanjay Magavi and Blair Leavitt
triggered the new growth by killing specific neurons
_ a procedure
that the scientists do not envision as part of any future
Future experiments will focus on understanding exactly what
triggers the creations of neurons and developing drugs
manipulations that do not involve killing cells to create
Any new treatments for neurological disorders like Alzheimer's
and Parkinson's disease or nervous system injuries are
and experiments away.
``We just have to keep in mind that you can do things in the
brain of a mouse that you can't necessarily do in people,''
Bruce Dobkin, director of the neurologic rehabilitation
research program at the University of California at Los
And the fact that a connection sprouted does not mean it
functions like the neuron it replaced.
``It's a little bit like you're wiring a switch on your door to
the bell in the hallway,'' Dobkin said. ``You can do
some things to
know that there seems to be a connection there, but you
haven't pressed the button and seen the bell go off.''
Heart Group OKs Stem-Cell Research
June 26, 2000
By KELLIE B. GORMLY=
Associated Press Writer=
DALLAS (AP) _ The American Heart Association has agreed to support stem-cell
research, putting it on a collision course with abortion opponents.
Officials of the heart association said stem cells, the building blocks
of human tissue, hold out hope for helping people suffering from heart
disease, strokes and other ailments. But the stem cells' sources -often
aborted fetuses or discarded human embryos - have triggered opposition
from some medical ethicists and anti-abortion groups.
The heart association's 43 board members agreed Sunday to support the use
of donors' money and federal funds to support stem-cell research.
``Ultimately, the board felt that this research has the opportunity to
save millions of lives,'' said Dr. Rose Marie Robertson, the association's
president-elect and a professor of medicine at Vanderbilt University in
The move had been recommended by an eight-member task force that the board
appointed to study the issue. The task force included scientists and a
bioethicist, and it conducted extensive interviews with councils and organizations
from all sides of the issue, heart association officials said.
The decision approves stem-cell research as a candidate for future funding
but does not necessarily dispense money to any particular research project,
an association spokesman said.
The association also will not fund any stem-cell research until strict
guidelines to prevent abuses are in place, Robertson said.
Although specific guidelines are being explored and should be adopted within
six months, they would include prohibiting the creation of embryos to harvest
stem cells or to create a human being. The guidelines also would prohibit
payment to people such as donors or doctors for stem cell research.
Such guidelines are not reassuring to anti-abortion opponents, said Kyleen
Wright, president of the Texans for Life Coalition.
``You still have the same problem,'' Wright said. ``On the one hand, you
want to reduce abortions in this country ... but on the other hand, you're
creating a whole new market that depends on abortion.''
The American Heart Association called stem-cell research the ``most promising
medical and scientific research'' to help fight cardiovascular disease
and stroke, the No. 1 and No. 3 killers in the United States.
Association officials estimate that 128 million Americans - 58 million
of them with cardiovascular disease - have ailments including cancer, Parkinson's
disease and osteoporosis that could be treated or cured with discoveries
from stem-cell research.
The cells could eventually be cultivated to become cardiac tissue, then
transplanted into failing or weakened hearts, medical experts said.