Mr Powell Lesson Outcomes… 1.I will be able to give examples of how stem cells can be used to...
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Mr Powell Lesson Outcomes… 1.I will be able to give examples of how stem cells can be used to treat illnesses (Basic) 2.I will be able to explain the differences
Mr Powell Lesson Outcomes 1.I will be able to give examples of
how stem cells can be used to treat illnesses (Basic) 2.I will be
able to explain the differences between how adult stem cells and
embryonic stem cells work. (Medium) 3.I will be able to explain
which type of stem cell is suitable for certain treatments and why.
(Harder)
Slide 2
The small blocks are ok but when they grow up
Slide 3
Can you fill in the missing gaps
Slide 4
3) Use your applications of stem cells sheet to fill in the
relevant row. 4) Prepare an oral (spoken) presentation to the rest
of the class which lasts 1 minute to complete the sheet. You may
use my ready made PPT slides as well. (Harder) 1) Summarise this
sheet of information into a short paragraph and put it here.
(Basic) 2) Summarise this sheet of information into a short
paragraph and put it here. (Basic) Total Time 15 mins Total Time 15
mins
Slide 5
Embryonic stem cells replicate to produce any specialised cell
(differentiate). Adult stem cells are different as they only
produce one type of specialised cell in the area of the body that
they are found. skin liver nerve red blood stem Humans start with 1
cell, which divides over and over to produce a baby An Embryonic
stem cell is found in a blastocyst (5 day old embryo). A Blastocyst
contains around 100 stem cells in total. These cells are
unspecialised and can replicate into any type of specialised cell.
Blastocyst stem cell Embryonic stem cells can be harvested. We can
use discarded embryos from fertility treatments (controversial with
many religious groups). They can be controlled in a lab to form a
specialised cell of the scientists choosing which is then altered
or implanted into a patient with an illness. KEY FACT: embryonic
stem cells which are unspecialised cells that can develop into any
type of cell. Only found in early stages of life.
Slide 6
Specialised cells cannot divide, and after a while they die and
must be replaced by stem cells which have divided. Blood cell 120
days Adult stem cells are used to repair body tissues e.g. skin in
the same area of the body in which they are found. For example bone
marrow stem cells turn into any of the usual blood cells found in
the body (differentiates) platelet white blood red blood adult stem
New developments in gene therapy have shown that we can turn an
adult stem cell into an embryonic stem cell by reprogramming it.
KEY FACT: adult stem cells are unspecialised cells that can develop
into many, but not all, types of cells. They are found in certain
areas of the body only. Adult stem cell Nucleus splits Cell splits
Hairless skin cell Embryonic stem cell New skin cell with
hair!
Slide 7
Skin grafts have been used for centuries, although no one knew
exactly why they worked until fairly recently. Skin is particularly
rich in stem cells. Because so much skin is lost through normal
wear and tear; you shed thousands, or even millions, of dead skin
cells every day. In mild cuts and burns, these stem cells work to
repair the damaged tissue. In severe burns the stem cells in the
burn area are destroyed, so doctors have to take skin from an
undamaged area. There is an obstacle in carrying out skin grafts,
for example; if a person suffers burns, only the skin from that
same person (from another area of their own body) could be used for
a skin graft. If doctors tried to use skin from another person, the
immune system of the person who suffered the burns would eventually
reject the graft. In trials scientists are now trying to take a
stem cell from a person and modify it genetically to turn it into
an embryonic stem cell and then make a skin cell culture. For
example; We could then make as much skin as the person needs to
repair burns, without having to take skin from other areas of their
body.
Slide 8
Male baldness is mainly caused by too much of a certain type of
protein in the skin or for women a hormonal imbalance. This is a
localised effect and can be reversed in some people. Adult skin
stem cells with the ability to grow hairs can be taken from another
part of a persons body (i.e. your arm). The adult skin stem cells
can then be separated from other cells in the sample by use of a
centrifuge (object which spins the sample around). The adult skin
stem cells which have been separated from the normal cells are the
only cells which are then injected into the patients scalp and hair
growth starts again. In trials Japanese researchers took hairless
mice and used complex techniques to merge embryonic stem cells with
adult skin cells to make a new skin stem cell which would grow
hair. Then they implanted the new cells into the skins of the mice.
It took 21 days to grow the new hair structures and roots. We can
take the nucleus from one cell and combine with another cell to
produce a genetically modified cell. It is a complex process but
shown simply here Hairless skin cell Embryonic stem cell New skin
cell (hair generating) Transplants cannot prevent previous
hormonal/protein type problems which can reoccur. Transplants can
only be permanent if the underlying problems are fixed.
Slide 9
Red and Yellow Bone Marrow from ball at top of femur (thigh
bone) Bone marrow problems can occur when we get infections such as
tuberculosis. Sometimes the bone marrow starts to produce too many
or too few of one type of cell. Often cancer treatments such as
radiotherapy can kill bone marrow as well. Bone marrow has an
important job to do in the body; the stem cells in the marrow are
able to produce exact copies of themselves as well as being able to
produce red blood cells, white cells and platelets. We call this
differentiation For bone marrow treatment, we extract adult stem
cells from a donor and then inject them into a patient where they
differentiate. The body of the donor is able to replace the bone
marrow stem cells within six weeks. After donating, most donors are
back to their usual routine in a few days. The patient will often
have a treatment such as chemotherapy (strong drugs) to kill all
their white blood cells before their bone marrow treatment so the
white cells dont kill the donor cells.
Slide 10
Cells inside the eye can stop working for a variety of reasons;
damage, infections, excess pressure inside the eye and diabetes. As
the cells are from a donor they can be rejected completely or grow
into tumours (cancers) inside the eye. Powerful drugs can help
prevent this and must be taken for a few months after the
operation. Marcus Hilton (first European patient) Stem cells can
help the eye recover by taking embryonic stem cells from a donor
embryo and culturing them to grow into retina type cells (found at
the back of eye). The stem cells are then injected into the
patient. A better method would be to take adult stem cells from the
patient and engineer them into embryonic type cells to avoid this
rejection and allow regeneration.
Slide 11
FocusCondition(s)Stem Cell TreatmentProblems Skin Cells Trials
Embryonic but patient can donate their own skin Hair Cells
Red/White blood cells & platelets (Bone Marrow) Chemotherapy /
Radiotherapy, infections, wrong number of cells growing Retina
(eye) cells Can be rejected by the patient so need to take strong
drugs to prevent this ADULT STEM CELLS: EMBRYONIC STEM CELLS:
Slide 12
FocusCondition(s)Stem Cell TreatmentProblems Skin CellsHeat or
chemical burns Trials Embryonic but patient can donate their own
skin Adult donor skin would be rejected Hair Cells Baldness from
hormones or excess protein Patient donates own + Trials of
Embryonic Need follicles to transfer but does not prevent
underlying previous causes Red/White blood cells & platelets
(Bone Marrow) Chemotherapy / Radiotherapy, infections, imbalance of
growth or lack of growth Another Adult Donor Can be rejected by the
patient so have to kill their own bone marrow Retina (eye) cells
Damage, infection, lack of growth Trials of Embryonic only Can be
rejected by the patient so need to take strong drugs to prevent
this ADULT STEM CELLS: adult stem cells are unspecialised cells
that can develop into many, but not all, types of cells. They are
found in certain areas of the body where they replicate EMBRYONIC
STEM CELLS: are cells which are unspecialised cells that can
develop into any type of cell if cultured under the right
conditions.
Slide 13
1.Give an example of how these cells can be used to treat
illnesses. (Basic) 2.Explain what is the difference between adult
stem cells and embryonic stem cells. (Medium) 3.Give an example of
a specific type of treatment and why it needs embryonic or adult
stem cells. (Harder)
Slide 14
Can you fill in the missing gaps Outcomes Assessment.. 1) 2)
3)
Slide 15
Mr Powell Lesson Outcomes 1.I will be able to give examples of
how stem cells can be used to treat illnesses (Basic) 2.I will be
able to explain the differences between how adult stem cells and
embryonic stem cells work. (Medium) 3.I will be able to explain
which type of stem cell is suitable for certain treatments and why.
(Harder)
ADULT STEM CELLS: Multipotent cells have the potential to give
rise to a variety of cells. A blood stem cell that can develop into
several types of blood cells, but cannot develop into brain cells
or other types of cells. These occur at the end of the long series
of cell divisions that form the embryo cells that are terminally
differentiated, or that are considered to be permanently committed
to a specific function. ADULT STEM CELLS: Multipotent cells have
the potential to give rise to a variety of cells. A blood stem cell
that can develop into several types of blood cells, but cannot
develop into brain cells or other types of cells. These occur at
the end of the long series of cell divisions that form the embryo
cells that are terminally differentiated, or that are considered to
be permanently committed to a specific function. EMBRYONIC STEM
CELLS: Pluripotent means the ability to divide into all the types
of cells except extra-embryonic tissues (umbilical cord, placenta)
Zygote: Totipotency is the ability of a single cell to divide and
produce all the differentiated cells in an organism, including
extra embryonic tissues. An example would be a zygote or fertilised
egg cell at the start of life.