Human stem cells
New source of stem cells found in
Amniotic fluid and placenta tissue
Types of stem cells:
There were originally believed to be only two different types of stem cells:
||Embryonic stem cells: These are pluripotent. That is, they have
the potential of developing into any of the 220
cell types in the human body (e.g. blood cells, heart cells, brain cells,
muscle cells, bone cells, etc). Unfortunately, they can only be obtained
from embryos. This causes very serious ethical problems among those who believe that
human life becomes a human person at conception. Once stem cells are removed
from an embryo, that embryo can no longer trigger a pregnancy, and be born. Some pro-life
advocates consider this to be the murder of a human being.
||Adult stem cells: These can be harvested from newborns, children
and adults with fewer ethical concerns. However, they have already started
to specialize and thus do not have the same level of flexibility as do
embryonic stem cells. They have only limited usefulness.
using adult stem cells has been underway for decades whereas studies using
embryonic stem cells only began when the cells were first isolated in 1988. Thus, adult cells are already being
used in clinical human trials of treatments and cures, whereas trials using
embryonic stem cells are still many years away.
A National Institutes of Health news release states:
"...research involving human pluripotent stem cells...promises new
treatments and possible cures for many debilitating diseases and injuries,
including Parkinson's disease, diabetes, heart disease, multiple
sclerosis, burns and spinal cord injuries. The NIH believes the potential
medical benefits of human pluripotent stem cell technology are compelling
and worthy of pursuit in accordance with appropriate ethical standards."
Now, a third type of stem cell has been isolated.
They can be harvested from amniotic fluid which surrounds the fetus during
pregnancy, or from the placenta which is delivered after birth and routinely
Amniotic/placental stem cells:
In 2005, researchers at the University of Pittsburgh discovered that
embryo-like stem cells could be obtained from the placenta. They are called
"amniotic epithelial cells" after the amnion -- the outer membrane of the
placenta's amniotic sac. Stephen Strom, an associate professor of pathology at
the Pitt medical school and a researcher at the university’s McGowan Institute
for Regenerative Medicine said:
"We think it would be easier to get these to the clinic than [embryonic
stem] cells. [They were coaxed to differentiate] into several different
tissue types, including liver cells, neurons, heart cells, pancreatic cells
with the potential to produce insulin, and glial cells which form part of
the nervous system." 2
Each placenta contains about 300 million amniotic
epithelial cells that could potentially be expanded to between 10 and 60 billion
Also in 2005, Dr. Dario Fauza of Boston's Children's Hospital discovered that
amnionic fluid stem cells might be used to treat a range of birth defects. 3
A study released in 2007-JAN by North Carolina’s Wake Forest University
School of Medicine and Harvard University shows that this third type of
stem cells, obtained from amniotic fluid, seem to combine the best
features of both embryonic and adult stem cells:
||They do not require the destruction of an embryo. Thus there should be
minimal protests from the pro-life movement.
||They can apparently be coaxed into developing into a wide range of cell
||They are much easier to obtain than embryonic stem cells.
They can double in number every 36 hours. They can divide at least 250 times
without mutating and without forming tumors. They have been converted into bone,
heart muscle, blood vessels, fat, nerve and liver tissues in lab mice. Unlike
embryonic stem cells, they cannot reproduce indefinitely.
Dr. Anthony Atala, head of the Institute for Regenerative Medicine at
Wake Forest University said:
"It has been known for decades that both the placenta and amniotic fluid
contain multiple progenitor cell types from the developing embryo, including
fat, bone, and muscle. ... We asked the question: 'Is there a possibility
that within this cell population we can capture true stem cells?' The answer
The potential of amniotic stem cells:
There is a real possibility that amniotic stem cells might be routinely
harvested from pregnant women, and be banked for future use. Later, if a child
or adult becomes ill or injured, they would be able to draw on these stem cells
for treatment or a cure. The cells could be coaxed to convert into the desired
type of cell, caused to replicate, and finally to produce a brand new organ for
transplant. Since the DNA of the stem cells are a perfect match to the child's
or adult's DNA there would be no risk of rejection.
Ethical aspects of amniotic/placental stem cells:
The pro-life community has not yet responded with its thoughts on this new
source of stem cells. We can conceive of two objections to this line of research
that they might have:
||Extracting amniotic fluid from a uterus poses a very small but non-zero
risk to the pregnant woman and to the fetus. This objection might be overcome if stem cells
can be reliably extracted from the placenta which is delivered after birth
and routinely discarded.
||A portion of the sample of amniotic fluid removed from the uterus could
be separately tested for genetic abnormalities, like the defect that causes
Down Syndrome (a.k.a. Down's Syndrome). If this were done, and if the
potential parents were notified, past experience shows that essentially all would choose to have an
abortion. If the amniotic were not sampled, the potential parents would be
unaware of the abnormality and would not have an abortion.
"NIH publishes final guidelines for stem cell research,"
National Institutes of Health, 2000-AUG-23, at:
"Placenta Cells Share Characteristics of Embryo Cells Without Tumor
"Discarded placentas deliver researchers promising cells they report are
much like embryonic stem cells," Hype and Hope, 2005-AUG-05, at:
- "Amniotic stem cell
discovery backed up by new study," LifeSiteNews.com, 2007-JAN-08, at:
Copyright © 2007 by Ontario Consultants on
Original posting: 2007-JAN-09
Latest update: 2007-NO-21
Compiled by B.A. Robinson