Introduction Stem cells are undifferentiated cells of body that do not possess any specific structure or function which means they don’t...
Introduction
Stem cells
are undifferentiated cells of body that do not possess any specific structure
or function which means they don’t have any specific job, like others cells do.
However they do have the potential to become like other cells of the body.
Mostly the body uses stem cells to replace destroyed cells by formation and
development of stem cells into that specific type of cell. The example of this
is the replacement of linings of intestine every four days by the stem cells
underneath the linings.
Scientists
are hoping to discover a special type of mechanisms for the replacement of own
body parts by the use of stem cells research. Stem cell researchers are trying
to find new ways to use stem cells to create tissues to replace the parts of
organs that are being damaged by injuries or disease. This approach is called
regenerative medicine.
Where are
Stem Cells located?
Stem Cells
usually evolved from two main sources, the embryonic stem cells formed during
embryonic development and the adult stem cells formed from the adult tissues.
The adult
stem cells are formed after embryonic development and are found across the body
in different tissues as brain, skin, liver, bone marrow, skeletal muscles etc. These
cells can then differentiate into different types of organ depending mostly on
their origin, but they can also form other organs irrespective of their organs.
Most stem cells found in bone marrow are called as Hematopoietic Stem Cells
while some stem cells are found in blood stream and are called as peripheral
blood stem cells.
Embryonic
stem cells on other hand are located in the body of embryo during the
blastocyst stage.
What is
Stem cell Transplantation?
Transplantation
is a replacement technique of organs or tissues in which destroyed organs are
tissues are replaced in the receiver from a proper medically acceptable donor.
Stem cell transplant refers to insertion of healthy and working stem cells into
the body for specific functions. The transplant is necessary if bone marrow
doesn’t produce healthy stem cells and then the transplantation may result into
the production of healthy cells causing enough White blood Cells, Red Blood
Cells and Platelets to reduce the risk of diseases that are related to its
deficiency like anemia and leukemia.
Figure 1 Stem Cell
Transplantation (Defined)
Stem Cell
transplantation depends on the source from which stem cells are taken and thus
the transplants are given names like bone marrow transplant and umbilical cord
transplant depending on the source.
Types of
Stem Cell Transplantation:
The
transplantation comprises of different types (mainly 3) depending upon the
condition of patient and the presence of enough stem cells required for the
transplant inside the donor body so that it transfer from donor may not cause
any damage to the donor and also it matches with the requirements of receiver
or not.
The three
main types are discussed as below:
1. Autologous
transplants:
This type of
Transplant refers to the transfer of own stem cells to the body later after
treatment of a certain disease. The stem cells from the body are taken and
preserved by method of freezing and are kept under controlled conditions so
that they remain able for use again.
The example
is the transfer of person own stem cells after cancer treatment. In this method
the stem cells are removed from the body and frozen and preserved. The patient
is then subjected to the different process like chemotherapy and radiation to
kill the maximum number of cancerous cells so that the different toxic cells
are destroyed and then during transplantation the stem cells are not rejected
and destroyed.
The stem
cells are then inserted into patient’s body after the treatment.
2. Syngeneic
transplants:
In this type
of transplant the identical twin is taken as donor and stem cells are only
donated if there is identical twin available for the receiver. The identical
twins have same genetic structure and this there are minute chances of
rejection. This type of transplant is very rare because the twins occurring
probability is also less in the world.
3.
Allogeneic Transplants:
In this type of transplant the donor is closely related person who
possess some close relation with receiver either like brothers, sisters, or
another person having match with receiver in the special proteins on blood cell
surfaces called HLA: Human Leukocyte Antigens. This match finding process is
called tissue typing and it depends on certain HLA markers which if similar
between the donors and receiver will show a match between them.
Stem Cell Research:
Stem Cells research refers to studies related to the work and development
on the use and increase of stem cells in the body for the treatment of
different diseases and also for the regeneration of organs and treatment of
destroyed parts of it.
Stem cells research primary reason is to understand the mechanisms how
different types of origin oriented stem cells are differentiated into
respective types of cells with proper functioning.
The theme is to then use these understandings for the uplift of treatment
system of fatal diseases and also to work on regeneration of organs and its
destroyed parts.
Stem Cells research is applied in different systems for the advancement
of disease treatments of that system like in blood and skin system the research
is used along with cell therapy and gene therapy to target the origins of
different heritable disease and end it forever.
Stem cells therapies are also applied in muscle regeneration and bone
injury and still advancements are underway in it.
For treatment of diabetes type 1 disease the stem cells treatments are
applied on embryonic level to enable insulin producing Beta Cells that are
normaly destroyed in the mother.
In the blood
Stem Cell therapies the most work is done on bone marrow and umbilical cord
transplants to give best possible treatments to blood leukemia cancer and other
such related diseases.
The study of
embryonic stem cells provide the basis for understanding the systems of
different tissue and organs formation and also helps for modeling cellular
development process. This can help in future for complete organ formation from
desired stem cells if the process is fully understood.
Furthermore
the study of adult stem cells indulges researchers to find details of directed
control mechanism of innate repair system and also provides understanding of
growth factors. Such researches are underway on neural and brain tissues and
also on heart tissues.
The Stem
Cells researchers have made possible the treatment of below diseases and injuries
using the embryonic Stem Cell Treatments
·
Rheumatoid arthritis
·
Traumatic spinal cord injury
·
Severe burns
·
Parkinson’s disease stem cells research
·
Heart disease
·
Hearing loss
·
Retinal disease
·
Huntington’s disease
·
Stroke
·
Diabetes type 1
·
Leukemia
Drug
Testing and Development:
Stem cell
research also provides a path for drug testing and its effects on different
organs and tissues when applied to original organism. This will lead to better
development of drugs and will in turn lead to better treatment process of treatment
of disease if the drugs are directly tested on humans (by stem cells research).
Stem Cell
Controversy:
Stem cells
transplant is considered very useful technique but the embryonic stem cell
technique requires destruction embryo for harvesting the embryo stem cells and
thus is considered against the ethics of the society which demands equal rights
for all life forms. The international society made for human rights and
privilege considers the embryo as a full human and also gives all its rights to
the embryo and thus destruction of embryo is against the rules of society which
gives ethical proof for stoppage of such actions. The
embryonic stem cell therapy supporters on other hand considers the embryo as
not full developed human and thus they prefer is for research purposes.
However
after the discovery of Pluripotent stem cells also called iPSCs which are the
cells directly generated from adult cells and thus are thought to have the
possibility of development into human embryo and thus there is less need of use
embryonic stem cell harvesting for use then. However if the use of such process
produces a clone of donor then another ethical issue arises that clones of
human (which are not made yet) also are humans are possess same humane rights.
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