affeb971-df68-47 4 H4sIAAAAAAAE
http://imageserve http://w eb.ebsco enabled
Stem Cell Research: An Overview
Embryonic stem cells are undifferentiated cells that show promise in the treatment
of heart disease, cancer, spinal cord injuries, diabetes and Parkinson's disease. For
example, if stem cells are introduced into a patient's heart after a heart attack,
they will migrate to the site of the damage, proliferate, and differentiate into new
cardiomyocytes, or heart muscle cells. Stem cells injected into the brains of
Parkinson's patients can become healthy neurons. Neural stem cells can even track
and destroy migrating cancer cells in brain tumors. Research on the applications of
stem cells to repair damaged tissue has given rise to a new medical specialty
known as regenerative medicine.
Human embryonic stem cell research is a controversial topic because the cells are
derived from eight-celled human embryos called blastocysts. To obtain stem cells
from the inner cell mass of the blastocyst, the embryo must be disassembled. The
component cells are then grown in culture. A blastocyst is a microscopic five-day-
old sphere of cells, not a recognizable human fetus. Still, it does have the potential
to grow into a baby, and this is the heart of the debate.
United States President George W. Bush and other social conservatives argue that it
is not right to destroy a potential human life, even to benefit others. Some anti-
abortion activists view killing an embryo as morally equivalent to murder. Scientists
and patient's rights advocates do not agree that an embryo is entitled to full human
rights. Advocates of stem cell research, such as former U.S. First Lady Nancy
Reagan and actor Michael J. Fox, focus on the help that stem cell research can
bring to suffering patients.
Efforts are underway to develop alternative sources of stem cells. Human somatic
stem cells, or adult stem cells, can be isolated from umbilical cord blood as well as
adult tissues and organs. Adult stem cells appear to have many of the regenerative
properties of embryonic stem cells.
Understanding the Discussion
Angiogenesis: The development of new blood vessels. In diseased hearts,
angiogenesis is stimulated by the introduction of stem cells.
Cell Lines: Groups of cells produced in a laboratory from common ancestry. The
cells within a cell line are usually genetically identical to one another.
Dopamine-Producing Nerve Cells: Certain neurons in the brain produce
dopamine, a neurotransmitter that sends signals from one cell to another.
Dopamine is involved in movement and experiencing pleasure; because of this,
Parkinson's disease patients may display involuntary movements and suffer from
Parkinson's Disease: A degenerative disorder of the brain caused by the death of
cells that produce dopamine. Parkinson's sufferers often have tremors and
uncontrolled movements that can make speech difficult. The disease may progress
to dementia in its later stages. Actor Michael J. Fox is a stem cell research advocate
who suffers from Parkinson's disease.
Undifferentiated Cells: Unspecialized cells with the potential to become one of a
variety of cell types. If grown with a certain type of cell they often differentiate, or
mature, to become that type of cell. Such cells are also described as pluripotent.
In November 1998, two research teams led by James A. Thomson of the University
of Wisconsin and John D. Gearhart of Johns Hopkins University School of Medicine
independently announced the isolation of human stem cells. The find was widely
recognized as one of great medical and ethical importance. Senate hearings to
debate federal funding for research on the newly-discovered cells began the
In the summer of 2000, the U.S. National Institutes of Health (NIH) and the
American Heart Association came out in favor of embryonic stem cell research.
Over objections from pro-life activists from the National Right to Life Committee,
the Clinton administration allowed federal funds for the research. Federal funding
was contingent upon researchers agreeing to use only leftover frozen embryos from
fertility clinics. Additionally, no financial compensation was allowed for donors
because of concerns about engendering a commercial trade in embryos.
The policy changed when George W. Bush became president in January 2001. In his
election campaign, Bush had been an outspoken opponent of any research involving
the destruction of human embryos. Despite pleas from the American Medical
Association and a coalition of eighty Nobel laureates, federal funding for embryonic
stem cell research was discontinued. The decision was applauded by a broad
alliance of conservative anti-abortion and religious groups.
Churches were split on the issue. Bush's ban was supported by the evangelical
Christian organization Focus on the Family, as well as Southern Baptist and Catholic
churches. However, the United Church of Christ and the Presbyterian Church both
made public statements in support of stem cell research conducted according to
Privately-funded embryonic stem cell research remained legal in the United States.
Stem cell research and its potential products represent a significant source of
revenue to participating institutions, so pharmaceutical companies continued their
independent programs. University-based scientists had fewer funding options, and
worried that American laboratories would become academic backwaters as new
discoveries were made overseas.
President Bush amended his funding ban in 2001, citing the potential of stem cells
to cure diseases. Federal funding would become available for stem cell research,
but only on sixty existing cell lines. No living or future embryos could be destroyed
to obtain new cell lines. Bush's compromise drew fire from both sides of the
Anti-abortion Christian groups viewed the use of cell lines derived from a destroyed
embryo as disrespectful to human life. Some even went so far as to draw parallels
between embryonic stem cell research and experiments done in Nazi Germany on
The American Cell Therapy Research Foundation, a stem cell advocacy organization,
expressed concern about the number and quality of existing cell lines allowed under
the revised rule. They asserted that there are only about two dozen legal lines, not
sixty, and all have been contaminated by growing in culture with mouse cells.
Advocates also point out that cell cultures may be used in drug development, so the
lines in use should be representative of all the ethnic groups in the country. The
current lines are not ethnically diverse. Infertility clinic patrons, whose surplus
embryos were used as the source for most cell lines, are predominantly white.
Since the controversy centered on the destruction of human embryos, scientists
began to look for alternative sources of stem cells. In 2001, stem cells were
isolated from adipose (fat) tissue. Since then, adult stem cells have been found in
many organs of the adult body, and in umbilical cord blood. Efforts are underway to
use these cells to replace dopamine-producing nerve cells in the brains of
Parkinson's disease patients. Adult stem cells also show promise in stimulating
angiogenesis in weakened hearts, and might be useful in producing insulin for
Stem Cell Research Today
In July 2006, the U.S. Senate passed the Stem Cell Research Enhancement Act of
2005, a bill that relaxed restrictions on government funding for stem cell research.
The bill would allow frozen embryos in fertility clinics to be used for research as an
alternative to disposal (it is currently legal to dispose of surplus embryos by
incineration or by flushing them down a drain). President George W. Bush vetoed
that bill, citing moral objections to the destruction of new human embryos.
Privately-funded embryonic stem cell research remains legal in the U.S., as does
federally-funded research using existing cell lines.
Rules regarding embryonic stem cell research differ throughout the rest of the
world. As of 2003, the United Kingdom, Sweden, Finland, Greece, and the
Netherlands all allowed embryonic stem cells to be sourced from surplus embryos in
fertility clinics. The practice was illegal in France, Ireland, Spain, Denmark, and
Austria. Most Asian countries permit embryonic stem cell research. Few laws
concerning stem cell research have passed in Muslim countries, although the
practice is controversial there. Concern is growing among medical professionals that
countries that ban embryonic stem cell research will lose top researchers to well-
funded institutions in other countries.
The rhetoric escalated in June 2006 when Cardinal Alfonso López Trujillo, leader of
the Catholic Pontifical Council for the Family, threatened Catholic stem cell
researchers and embryo donors with excommunication.
In May of 2009, President Obama reversed the Bush administration's restriction of
using taxpayer money to fund research on only 21 stem lines. At that time,
however, no change was made to the ban on using federal money to develop stem
cell lines. Federal money may be used to research lines that were created without
the use of federal funds, however.
These essays and any opinions, information or representations contained therein
are the creation of the particular author and do not necessarily reflect the opinion of