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What
are stem cells and what are they used for?
.
Stem cells have the ability to
change into other types of cells. Because stem cells can become bone, muscle,
cartilage and other specialized types of cells, they have the potential to
treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. Stem cells are already being used to
treat leukemia and some joint repairs.
HowStuffWorks
Stem cells are
unprogrammed cells in the human body that can be described as "shape
shifters."
These cells have the ability to change into
other types of cells.
Stem cells are
at the center of a new field of science called regenerative medicine.
Because stem
cells can become bone, muscle, cartilage and other specialized types of cells,
they have the potential to treat many diseases, including Parkinson's,
Alzheimer's, diabetes and cancer.
Eventually,
they may also be used to regenerate organs, reducing the need for organ
transplants and related surgeries.
"Stem
cells are like little kids who, when they grow up, can enter a variety of
professions," Dr. Marc Hedrick of the UCLA School of Medicine says.
"A child
might become a fireman, a doctor or a plumber, depending on the influences in
their life -- or environment. In the same way, these stem cells can become many
tissues by making certain changes in their environment."
Stem cells can
typically be broken into four types:
· Embryonic stem cells - Stem
cells taken from human embryos
· Fetal stem cells- Stem cells taken from aborted
fetal tissue
· Umbilical stem cells - Stem
cells take from umbilical cords
· Adult stem cells - Stem cells taken from
adult tissue
Embryonic and
fetal stem cells have the potential to morph into a greater variety of cells
than adult stem cells do.
In April 2001,
researchers at UCLA and
the University
of Pittsburgh found stem cells in fat sucked out of liposuction
patients. Previously, stem cells were found only in bone marrow, brain tissue
and fetal tissue -- sources that have caused both logistical and ethical problems.
Stem cells
from fat have the ability to mature into other types of specific cells,
including muscle, bone and cartilage, but how many other
types is still unknown.
Prior to being
transplanted into a person's tissue to begin regeneration of that tissue, stem
cells have to go through differentiation.
Differentiation
is the process by which scientists pre-specialize the stem
cells, almost like preprogramming the stem cells to become specific cells.
These cells
are then injected into the area of the body being targeted for tissue
regeneration.
When stem
cells come into contact with growth chemicals in the body, the chemicals
program the stem cells to grow into the tissue surrounding it.
Stem cells are
already being used to treat leukemia and some joint repairs.
For example, a
bone-marrow transplant is accomplished by injecting stem cells from a donor
into the bloodstream of the patient.
Stem cells
from bone marrow also have the ability to repair the liver. Researchers are
studying stem cells to find out if they could correct brain damage resulting
from Parkinson's disease.
The next step
will be to learn what influences stem cells to change into particular types of
cells.
Once that's known, it will be possible to grow cells that perfectly match those of the patients.
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