Did you ever hear anything about stem cells? 
OK then, 
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. 

1. Introduction (Jan  27, 1999)
2. Bone marrow stem cells do the trick in rats (May 13, 1999)
3. Stem Cell Research Tops '99 Science  (12/16/99)
4. Stem Cell Transplant in Mice Hailed  ( 12/27/99)
5. Diabetes Reversed in Mice   ( 02/29/00)
6. Master Cell' Research Spurs Debate    (04/26/00)
7. Mouse Brain Now Self Repairing  (06/21/00)
8. Heart Group OKs Stem-Cell Research  (June 26, 2000)

    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 cell garden. 

This headline was taken in part from: 
Promise of 'Master Cell' Research 
By LAURAN NEERGAARD= 
AP Medical Writer= 
http://www.infobeat.com/stories/cgi/story.cgi?id=2558142658-be6 

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 shown to
 convert into basic liver tissue, raising the possibility of one day using a patient's own marrow to repair failing livers, researchers say.
           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 tissue.
          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 livers.
           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 recovering.
           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 organ.
           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 damaged the
 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 process.
           ``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.

 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 medical applications.''
           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 research.
           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 order:
           _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 energy.
           _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 known.
           _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 years.
           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
 true.

 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 that damage
 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
 donor male.
           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 often have
 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 develop successfully
 after transplantation, they can be frozen and reintroduced into the
 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 physician
 in the Hematology-Oncology Department at the Children's National
 Medical Center in Washington.
           ``This is also exciting because this was one of the first times
 people have actually talked about there being offspring, as opposed
 to just being sperm cells under a microscope,'' added
 Perez-Albuerne, who was not involved in the research.
           Frozen preservation ``of testicular stem cells and
 post-treatment reintroduction, could protect germ cells from
 potentially (mutation causing) cancer treatments and safeguard
 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.

           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 how useful
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 pancreas.
People with this disease must inject themselves with insulin daily
to survive.
           Patients have been treated with transplants of islets, the
insulin factories of the pancreas. But the success rate has been
low, apparently in part because it's hard to get enough islets from
a cadaver's pancreas.
           The new work suggests a way to overcome that problem: prodding
immature stem cells from the pancreas to make abundant quantities
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 injections
over a few days. Within a week after injections stopped, they
showed a decline in blood-sugar levels. They remained healthy
without insulin injections until they were killed for examination
of the implant, a period of up to 55 days from implantation.

 By LAURAN NEERGAARD=
AP Medical Writer=
           WASHINGTON (AP) _ Paralyzed ``Superman'' star Christopher Reeve
urged Congress on Wednesday to let federally funded research use
master cells from discarded human embryos, questioning why some
lawmakers would rather throw away the embryos than use them in
experiments that Reeve believes could one day help him walk again.
           ``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?'' Reeve
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 Brownback,
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. They are
generating huge excitement among scientists because if doctors
could learn how to control stem cells, they possibly could cure
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 any research
into embryonic stem cells because of a congressional ban on any
research that destroys human embryos _ and taking stem cells from
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 conducted
only on cells already derived by private companies, so that
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. Both
approaches face opposition by at least 70 members of Congress.
           ``The embryos to be used here are discarded. If not used for the
research, they will not be used at all,'' Sen. Arlen Specter,
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 science to
Nazi contentions that ``these people are going to be killed, why
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 Harkin,
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 an
alternative.
           Scientists are trying that, too. But two NIH scientists told
senators that adult stem cells are far more scarce, and may not
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,'' said Dr.
Allen Spiegel, NIH's diabetes chief.

 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, raising
hopes of developing new ways of treating neurological diseases and
head injuries.
           The researchers induced the creation of the neurons in the
neocortex of lab mice by triggering stem cells, or precursor cells,
that already exist in the brain.
           Other research has shown that under specific conditions,
transplanted stem cells can form new neurons. The new study
indicates that transplantation may not be needed.
           Instead, a combination of molecular signals can accomplish the
same thing, said Dr. Jeffrey Macklis, a neuroscience professor at
Harvard Medical School and Children's Hospital who led the study.
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 brain
circuitry. The cells migrated to areas populated by the dead
neurons and sprouted axons, or connections, into the proper tissue.
           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
treatments.
           Future experiments will focus on understanding exactly what
triggers the creations of neurons and developing drugs or molecular
manipulations that do not involve killing cells to create new ones,
Macklis said.
           Any new treatments for neurological disorders like Alzheimer's
and Parkinson's disease or nervous system injuries are many years
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,'' said
Bruce Dobkin, director of the neurologic rehabilitation and
research program at the University of California at Los Angeles.
           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 still
haven't pressed the button and seen the bell go off.''

 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 Nashville, Tenn.
           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.