Wednesday, September 19, 2001
W7zaf are stem cells?
They are the precursor cells from which all the
Itissues in the body develop. They can continue
Ireplicating indefinitely and have the potential to
Idevelop into any specialized cell type, such as
Iblood cells or neurons.
Why are they important?
■ In addition to teaching scientists about how
jcells grow and develop, most researchers feel that
|stem cells offer great medical promise for future
medical treatments.
Stem cells could provide replacement cells to
treat diseases such as heart disease, Alzheimer’s,
diabetes, and cancer. Ultimately, they might
allow the growth of replacement organs.
What types are there?
Embryonic (or pluripotent) stem cells are
formed when a human embryo reaches the blas
tocyst phase a few days after fertilization. They
are the most versatile and can develop into any
type of tissue.
Adult (or multipotent) stem cells are formed
by the body to replace worn-out cells in many
organs and tissues. These cells can only develop
into a few predetermined tissue types.
Adult stem cells are much more difficult to
keep alive and growing in the laboratory, yet
there have been several recent successes.
Scientists differ in opinion on the relative useful
ness of adult and embryonic stem cells.
Stem cells collected from animals are also
commonly used in research, but the medical use
of such cells is limited by fear of zoonotic dis
eases and immune rejection.
Why all the debate?
Many people are opposed to the destruction of
a human embryo for any purpose, feeling that it
violates the sanctity of human life. However,
many others support the research, arguing that
the potential medical benefits will help cure
many diseases and that the discarded embryos
being used would never have had the chance to
form a living human.
Building people... ^
FROM SCRATCH
By Melissa Braddock
THE BATTALION
The science fiction image of
organs growing in vats may not
remain fiction much longer.
One of the most promising areas
of research to utilize stem cell tech
nologies is tissue engineering, in
which researchers work to “build”
new tissues that can be used to
reconstruct or replace damaged
body parts.
“Unlike a damaged car, a dam
aged person can’t just be rebuilt
using spare parts, but that could be
changing soon,” said Dr. Antonios
Mikos, associate professor of bio
logical and chemical engineering at
Rice University and tissue engi
neering researcher.
In 1986, Dr. Joseph Vacant! and
Dr. Robert Danger developed the
method now used in most tissue
engineering projects. A biodegrad
able polymer is shaped into a scaf
fold in which stem cells are nur
tured and grown.
The whole structure of cells and
scaffold is transplanted into a
patient. As the cells replicate and
form new tissue, the polymer
breaks down, leaving only the new
tissue or organ, indistinguishable
from its surroundings.
Today, doctors can treat victims
of severe burns with lab-grown
skin taken from a plastic bag. In
other cases, patients have had carti
lage grown and implanted into
knees and other joints.
Meanwhile, Mikos and his team
are working to develop bone tissue.
Unlike skin and cartilage, bone
requires an extensive blood supply.
something which is proving dif
ficult to create in engineered tissue.
Mikos is making progress, how
ever, and he has now developed
mature bone tissue in a matrix that
was inserted into a sheep ribcage.
Other researchers have already
grown simple organs such as blad
ders, and an international consor
tium of scientists known as Living
Implants from Engineering, or
LIFE,, has vowed to grow human
hearts within the next decade.
The heart will probably be
grown in four parts — valve, mus
cle, blood vessels, and conduits —
and then brought together.
Researchers have already creat
ed rudimentary blood vessels, heart
valves and heart muscles.
For now, the biggest limiting
factor for tissue engineering may
be money.
The LIFE
heart initia
tive alone
expected to need
$5 billion in
research funding.
But even as a new
field with limited funds,
encouraging results are
being reported.
“I really feel that it’s not
unrealistic to say that we will
eventually be able to recreate any
organ,” Mikos said. “This is the
beginning of a field that will change
the way medicine is done.”
A&M pursues research with stem cells
By Melissa Braddock
THE BATTALION
While the nation debates the
pros and cons of human embryonic
stem cell research, two Texas A&M
scientists are trying to unlock stem
cell secrets from a less controver
sial angle — by focusing on cells
taken from animals.
Although many researchers feel
human embryonic stem cells hold
the most research promise, others
think research can proceed using
adult stem cells and animal research.
Dr. Sumana Datta, professor in
Texas A&M’s Department of
Biochemistry and Biophysics, is
studying what triggers stem cells in
the brain to divide and grow.
In particular, she is using fruit
flies to look at how certain biochem
ical signals create patterns of stem
cell division in the developing brain.
“Stem cells are usually quiescent
- kind of like they are taking a nap.
We are trying to find out how the
body tells the stem cells of the brain
when they are needed,” Datta said.
This issue is of particular inter
est because cancer cells appear to
resemble stem cells that are grow
ing out of control, Datta said.
Meanwhile, Dr. Jorge Piedrahita,
a professor in the College of Veterinary
Medicine, focuses on stem cells
from pig embryos and fetuses.
Piedrahita’s lab has successful
ly isolated the stem cells and is now
working on steering them into the
desired developmental pathway, a
task that is often challenging for
stem cell researchers.
Ultimately, he would like to
genetically modify animals such as
pigs and cattle to create animals that
can be used as human organ donors.
Although stem cell research is
still in the early stages, many scien
tists feel that this work has the poten
tial to give rise to innovative treat
ments for a wide range of diseases.
Scientists such Datta and
Piedrahita hope one day to apply
what is learned from animal stem
cells to human treatments, or even
use animal tissues directly to repair
damaged organs in humans.
Despite optimism about animal
studies, animal studies can never
replace human stem cell studies.
“We can get a lot of good infor
mation out of animal studies,” Datta
said, “but we can never know what
is true for humans and what is dif
ferent in humans until we look at
human data.”
Business Career Fair
Receptions
FREE
Want to get a head start on your
employment future?
Want a casual way to interact with recruiters?
Come to the Business Career Fair Receptions.
Receptions 7-9 p.m.
• Monday, 19 th :
• Tuesday, 20 th :
• Wednesday, 21
st.
Cafe’ Eccell
George Bush Presidential Library
Briarcrest Country Club
Come by Wehner
September 19-26
and sign-up at the tables.
Business casual dress please.
TEXAS A Sc M UNIVERSITY.
BUSINESS STUDENT COUNCIL
http://wehner.tamu.edu/bsc
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