What are the sources of stem cells? 

Stem cells that do not raise any ethical questions are available from adults and children, umbilical cord blood, and even placentas.  Various cells of adults and children can be used to obtain stem cells. 

Bone marrow has been used frequently, but researchers are having success obtaining stem cells from various body tissues, including blood, bone, muscle, brain, fat, nasal/sinus, skin, and even baby teeth.  Obtaining stem cells from umbilical cord blood is showing great promise in finding treatments for some cancers, including leukemia.

Stem cells can also be obtained by killing human embryos, raising ethical issues.

What are stem cells capable of doing?

Stem cells are undifferentiated cells that can become various specialized cells needed by specific organs of the body.

There is significant interest in finding ways to use stem cells to repair diseases that originate in the brain, heart, liver, lungs, spinal cord, immune deficiencies, etc.  Some of these diseases include: Parkinson’s, diabetes, heart diseases, spinal cord injuries, cancer, some birth defects, etc.

Medical successes so far

Senator Bill Frist, a medical doctor, and Representative David Weldon, also a doctor, along with other doctors still in practice, have noted that no successes have yet been achieved with human patients using embryonic stem cells.  Similarly, experiments using rats and mice have shown virtually no successes or progress beyond very basic levels, often leading instead to development of tumorous-like growths.

At the same time, a long list of successful experimental treatments have been achieved using ethical sources of stem cells, reaching at least 72 by July 2006. These include:  

·        Spinal cord injury repair (using stem cells from nasal and sinus regions)

·        Complete reversal of juvenile diabetes in mice using adult spleen cells, with Harvard now preparing for human patient trials using spleen cells

·        Crohn’s Disease put into remission (using patient’s blood stem cells)

·        Lupus put into remission (using stem cells from patient’s bloodstream)

·        Parkinson’s disease put into remission (using patient’s brain stem cells)

·        Repair heart muscle in cases of congestive heart failure (using stem cells from bone marrow)

·        Repair heart attack damage (using the patient’s own blood stem cells)

·        Restore bone marrow in cancer patients (using stem cells from umbilical cord blood)

·        Restore weak heart muscles (using immature skeletal muscle cells)

·        Put leukemia into remission (using umbilical cord blood)

·        Heal bone fractures (using bone marrow cells)

·        Restore a blind man’s sight (using an ocular surface stem-cell transplant & a cornea transplant)

·        Recovery from a stroke (using stem cells from bone marrow)

·        Treat urinary incontinence (using under arm muscle stem cells)

·        Reverse severe combined immunodeficiency (SCID) (using genetically modified adult stem cells)

·        Restore blood circulation in legs (using bone marrow stem cells)

·        Treat sickle-cell anemia (using stem cells from unbilical cord blood)

 In addition to the above experimental treatments performed on human patients with life-threatening conditions beyond the help of traditional treatments, many other succesdful experiments have been performed on rats and mice using stem cells obtained from equivalent sources that did not involve killing embyros or cloning.

Sources of embryonic stem cells

 Sources:       1)  unneeded embryos created for in vitro fertilization

                        2)  eggs obtained from women and fertilized in the lab

3)     eggs obtained from women and used to clone embryos

In all three cases, the embryo, a living human being, must be killed to obtain the stem cells to be used for research or treatment.

Human Cloning

Cloning uses a process called somatic cell nuclear transfer.  Starting with an egg harvested from a woman, the nucleus is removed and replaced with the nucleus taken from a cell of another person, such as a skin cell.  This transfer makes the new cell the equivalent of a fertilized egg which is then stimulated to begin growing as an embryo. 

Impact on Women

Cloning requires harvesting eggs from women - a dangerous and unnatural process.  If the use of embryonic stem cells proved successful, millions of eggs would need to be obtained from women.

Massive use of such an invasive and dangerous medical procedure would put many women’s health at risk, raising more ethical questions.  Clearly, this approach is not a practical source of stem cells for commonly used medical treatments.

Therapeutic vs. reproductive cloning

Proponents of research using stem cells obtained from cloned human embryos like to make distinctions between therapeutic and reproductive cloning. 

They explain that human cloning should not be allowed to produce human beings (reproductive cloning).  Thus, implanting cloned human embryos in women should be illegal.

Rather, these researchers maintain that cloned embryos should only be grown to stages where stem cells can be harvested.   If any embryos are not killed to obtain their stem cells, then the law should require that they be killed.

Legal experts have testified that such a legal framework would be unenforceable.  Along with a number of prominent medical doctors, they view therapeutic cloning as a meaningless distinction.  Allowing any human cloning will lead to cloned human beings.

Why Cloning?

When tissues from one patient are given to another patient, normally these tissues are rejected unless the match is very close.  Even then, powerful drugs must be used to prevent rejection.  If embryonic stems cells are used, this rejection problem still exists.  The dream is to clone the person to make totally compatible stem cells available.

Of course, adult stem cells can already be obtained directly from a patient for treatments needed by that patient. Further, stem cells from umbilical cord blood can be more easily matched with a patient to reduce the likelihood of tissue rejection.

Bills in Illinois to Promote Human Cloning and Embryonic Stem Cell Research

In Illinois, a bill has been signed into law to establish the Illinois Regenerative Medicine Institute.  This institute would distribute allocated funds to encourage research using stem cells obtained from human embryos, including cloned embryos.  Provisions would also encourage research using aborted fetal tissue.  Fortunately, fundiing sources for this bill were not included in the final state budget produced by the 2007 legislative session. 

Bills in U.S. Congress to Ban Cloning

Concerns about the ethical issues raised by cloning led to an effort to pass a complete ban on human cloning in the U.S. Congress.  On February 27, 2003, H.R.534 to ban all human cloning was passed by the U.S. House of Representatives by a vote of 241-155 and was sent to the U.S. Senate. 

No action was taken in the Senate on that House bill or on an equivalent Senate bill.  Each bill was prevented from coming to a Senate vote by threat of a filibuster.  President Bush had indicated strong support for a complete ban on human cloning.

In the years since 2003 no further effort to pass a ban on human cloning has been attempted because of the continued roadblock of a potential Senate filibuster to prevent a vote on such a bill.

In fact, Congress twice passed bills (2006 and 2007) to allow so-called excess embryos from in vitro fertilization be made available for stem cell research.  President Bush vetoed both of these bills so they did not become law.  However, passage of such bills demonstrated the difficulty of making any further attempts to ban cloning.