Stem Cells

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Stem cells
1.What are stem cells?
Stem cells are the master cells of the human body. They can divide to produce
copies of themselves and many other types of cell. They are found in various parts of
the human body at every stage of development from embryo to adult. Stem cells
taken from embryos that. Are just a few days old, can turn into any of the 300
different types of cell that make up the adult body.
2.Are there different types?
Stem cells can be classified into three broad categories, based on their ability to
differentiate. Totipotent stem cells are found only in early embryos. Each cell can
from a complete organism (e.g.) identical twins. Pluripotent stem cells exist in the
un differentiated inner cell mass of the blastocyst and can form any of the over
200 different cell types found in the body. Multipotent stem cells are derived from
fetal tissue, card blood and adult stem cells. Although their ability to differentiate
is more limited than pluripotent stem cells, they already have a trach record of
success in cellbased therapies. Here is a current list of the sources of stem
1. Embryonic stem cell. Are harvested from the inner cell mass of the blastocyst
seven to ten days after fertilization.
2. Fetal stem cells. Are taken from the germline tissues that will make up the
gonads of aborted foetuses.
3. Umbilical cord stem cells umbilical cord blood contains stem cells similar to
those found in bone marrow.
4. Placenta derived stem cells. Up to ten times as many stem cells can be
harvested from a placenta as from cord blood
5. Adult stem cells. Many adult tissues contain stem cells that can be isolated.
3.Why stem cells are important?
Stem cell have two important chard cteristics that distinguish them from other types of
cels. First, they are unspecialized cells that renew themselves for long periods through
cell division. The second is that under certain physiologic or experimental conditions,
they can be induced to become cells with special functions such as the beating cells of
the heart muscle or the insulinproducing cells of the pancreas.

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This article tries to shed some light on how stem cells may be able to cure diabetes in the
future and why their use is controversial. It aims merely to inform and elucidate some of the
controversies surrounding this area of research.
Stem cells are the basis for every type of cell in the body they possess the ability to develop
into any of the body's tissues.…read more

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The use of cadaveric fetal tissue to derive cell lineslike the use of organs from other dead
bodies is the least controversial source of stem cells.
Many embryos that are created for fertility treatment are discarded because they are no
longer required or are deemed unsuitable. Using these cells for research in the battle against
disease seems, to many, justifiable as they will be destroyed in any event.…read more

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Juengst and Fossell raise the question, "How shall ethicists, clinicians, and any individual
concerned about these issues weigh the fate of the embryo, from which these cells are
derived, against the therapeutic value to patients with real medical needs?" In a debate in the
British House of Lords, over this issue, Lord Althon, stated "These are not trivial questions
that preoccupy a few moral theologians. They are at the heart of our humanity.…read more

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Homing provides hope that the transplantation of
stem cells will be a clinically useful procedure.
Despite these general similarities, there are some important differences between embryonic stem
cells, embryonic germ cells, and adult stem cells. The origins of these three cell types define their
differences: ES cells are derived from the inner cell mass of the blastocyst in a developing embryo,
EG cells are obtained from the primordial germ cells of a fetus, and adult stem cells are found in
developed, specialized tissues.…read more


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