1. Definition   2. History   3. Discrimination of stem cells from other types of cells 4. Types 5. Why stem cells are important 6. Properties 7. Application of stem cells 8. Advantages and disadvantages

1. PRESENTED BY: AYESHA KABEER
UNIVERSITY OF GUJRAT SIALKOT SUB CAMPUSPRESENTED BY: AYESHA KABEER
UNIVERSITY OF GUJRAT SIALKOT SUB CAMPUS

2. Contents: -
 Definition
 History
 Discrimination of stem cells from other types of cells
 Types
 Why stem cells are important
 Properties
 Application of stem cells
 Advantages and disadvantages

3. Definition: -
Stem cells are
undifferentiated
biological cells that
differentiate into
specialized cells and
can divide (through
mitosis) to produce
more stem cells.

4. • History of stem cells: -
 In 1998, researchers first extract stem cells from human embryos.
 In 2001, President Bush restricted federal funding for embryonic
stem-cell research.
 In 2002, Juvenile Diabetes Research Foundation International
creates $20 million fund-raising effort to support stem-cell research
 In 2004, Harvard researchers grow stem cells from embryos using
private funding

5. • Discrimination of stem cells from other types of
-
Stem cells have two important characteristics that
distinguish them from other types of cells.
 1. First, they are unspecialized cells that renew themselves
for long periods through cell division.

6.  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 insulin producing cells of the pancreas

8. • Types of stem cells: -
 There are several types of stem cells depending upon their
source and properties.
 1. Embryonic stem cells:-
These are isolated from the inner cell mass of blastocysts.

10. Adult stem cells:
Adult stem cells are found in certain tissues in fully
developed humans. This could be present in babies,
children, adolescents or adults. The primary roles of adult
stem cells in the body are to maintain and repair the
in which they are found. These stem cells are also called
somatic stem cells instead of adult stem cells as they may
be found in persons of all ages (not just adults).

11. Amniotic stem cells:
 These are stem cells found in the amniotic fluid. These can
be made into fat cells, bone cells, muscle cells, blood vessel
walls, liver and nerve cells.

12. Induced pluripotent stem cells:
 These are not adult stem cells but are created from adult
skin cells.

13.  Why stem cells are important: -
Stem cells are important for living organisms for many reasons. In the
3- to 5-day-old embryo, called a blastocyst, stem cells in developing
tissues give rise to the multiple specialized cell types that make up the
heart, lung, skin, and other tissues. In some adult tissues, such as
marrow, muscle, and brain, discrete populations of adult stem cells
generate replacements for cells that are lost through normal wear
tear, injury, or disease. It has been hypothesized by scientists that
cells may, at some point in the future, become the basis for treating
diseases such as Parkinson's disease, diabetes, and heart disease.

14. Properties of stem cells: -
1. Stem cells are capable of dividing and renewing themselves
for long periods:
Unlike muscle cells, blood cells, or nerve cells—which do not
normally replicate themselves—stem cells may replicate many
times. When cells replicate themselves many times over it is called
proliferation.

15.  2. Stem cells are unspecialized:-
One of the fundamental properties of a stem cell is that it does not have
any tissue-specific structures that allow it to perform specialized
functions. A stem cell cannot work with its neighbors to pump blood
through the body (like a heart muscle cell); it cannot carry molecules of
oxygen through the bloodstream (like a red blood cell); and it cannot
electrochemical signals to other cells that allow the body to move or
speak (like a nerve cell). However, unspecialized stem cells can give rise
specialized cells, including heart muscle cells, blood cells, or nerve cells.

16.  3. Stem cells can give rise to specialized cells:
When unspecialized stem cells give rise to specialized cells, the process
is called differentiation. Some signals both from within and from outside
the cell can trigger stem cell differentiation. While signals within the cell
are controlled by a cell's genes which are present over strands of DNA,
the external signals for cell differentiation include chemicals from other
cells, contact with neighboring cells and presence of certain molecules
in the environment.

18. • Applications of stem cells: -
 1. Stem cells can be used to study development: -
Stem cells may help us understand how a complex
organism develops from a fertilized egg.

19.  2. Stem cells have the ability to replace damaged cells and
treat disease: -
i. In diabetes, patients lose the function of their insulin
producing beta cells of the pancreas. In order to treat this
disease, embryonic stem cells may be grown in cell cultures
stimulate to form insulin-producing cells that can be
transplanted into the patient. i.e.

20. transplanted into patient

21.  ii. Rheumatoid arthritis, a disease causing inflammation in the joints and
resulting in deformity and immobility, especially in the fingers, wrists, feet, and
ankles. Adult stem cells may be helpful in starting repair of eroded cartilage.
 iii. In Parkinson’s disease, patients lack dopamine. Researchers are already using
stem cells to grow dopamine-producing nerve cells in the lab in order to replace
the lost nerve cells with healthy new ones.

22.  3. Stem cells could be used to study disease: -
In many cases it is difficult to obtain the cells that are damaged in a
and to study them in detail. Stem cells, either carrying the disease gene or
engineered to contain disease genes, offer a viable alternative. Scientists
could use stem cells to model disease processes in the laboratory, and
understand what goes wrong.
 4. Stem cells could provide a resource for testing new
medical treatments: -
New medications could be tested for safety on specialized cells
generated in large numbers from stem cell lines – reducing the need
for animal testing.

23. • Advantages of stem cells: -
 1. Immense medical benefits: -
It has been shown that they can be extremely beneficial in
therapeutic cloning to treat chronic illnesses.
 2. The key to reversing aging: -
Stem cells are the key to regenerative processes, which could
possibly be age reversal. By reviving organs in our body that have
become old or worn out, you could essentially live forever or at
least greatly prolong the lives of humans.

24.  3. Cure development defects before they happen: -
Stem cell research doesn’t just benefit the people walking around the
earth, but also the ones that haven’t been born yet. The effects of these
cells on embryos could change the way that birth defects are treated.
They could possibly be corrected before the child is even born, greatly
improving their quality of life and chance of survival.

25. • Disadvantages of stem cells: -
 1. High Uncertainties: -
One of the largest issues that people have with stem cell
research is just how risky and unknown it truly is. Major
advancements still need to be made and new technology must
be developed before it can be used in an efficient and safe way.

26. 2. Unknown Side Effects: -
Since stem cells are still in their research phase, the true long term effects
of their use is not known or understood. Using them could cause
new illnesses and disease to develop, or even interfere with the
natural functions of the body.
3. Playing God: -
The moral argument is another big one when it comes to this topic. Many
people believe that altering the basic structure of a human’s genes is putting
hands somewhere they should not be. The moral issue is the most frequently
argued.

27. 4. Perpetuates Cloning of Humans: -
Cloning is the process of making an exact genetic copy of a living
organism. Stem cell research also aids the research into human
cloning. Human cloning has been widely reviewed as a detriment to
society with many negative benefits.