Mr Powell

1. Mr Powell Lesson Outcomes… I will be able to give examples of how stem cells can be used to treat illnesses (Basic) I will be able to explain the differences between how adult stem cells and embryonic stem cells work. (Medium) I will be able to explain which type of stem cell is suitable for certain treatments and why. (Harder)

2. The small blocks are ok but when they grow up……

3. Key Stage 3 Revision Can you fill in the missing gaps…

4. Task Instructions 2) Summarise this sheet of information into a short paragraph and put it here. (Basic) 1) Summarise this sheet of information into a short paragraph and put it here. (Basic) Total Time 15 mins 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)

5. Embryonic Stem cells KEY FACT: embryonic stem cells which are unspecialised cells that can develop into any type of cell. Only found in early stages of life. Humans start with 1 cell, which divides over and over to produce a baby… 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. 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. red blood nerve stem 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. liver skin stem Blastocyst stem cell

6. ADULT STEM CELLS 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) Specialised cells cannot divide, and after a while they die and must be replaced by stem cells which have divided. Embryonic stem cell 120 days Blood cell New skin cell with hair! Adult stem cell New developments in gene therapy have shown that we can turn an adult stem cell into an embryonic stem cell by reprogramming it. Hairless skin cell red blood adult stem Nucleus splits white blood platelet 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. stem Cell splits

7. Skin Grafts 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. 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 trials scientists are now trying to take a stemcell from a person and modify it genetically to turn it into an embryonicstemcelland 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. In mild cuts and burns, these stem cells work to repair the damaged tissue. In severe burns the stemcells in the burn area are destroyed, so doctors have to take skin from an undamaged area.

8. Baldness 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… 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. Embryonic stem cell 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. New skin cell (hair generating) Hairless skin cell Transplants cannot prevent previous hormonal/protein type problems which can reoccur. Transplants can only be permanent if the underlying problems are fixed. 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.

9. Bone marrow 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” Red and Yellow Bone Marrow from ball at top of femur (thigh bone) 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. For bone marrow treatment, we extract adult stem cells from a donor and then inject them into a patient where they differentiate. 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 don’t kill the donor cells.

10. blindness 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. Cells inside the eye can stop working for a variety of reasons; damage, infections, excess pressure inside the eye and diabetes. 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. Marcus Hilton (first European patient) 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.

11. Review of Stem Cells EMBRYONIC STEM CELLS: ADULT STEM CELLS:

12. Review of Stem Cells EMBRYONIC STEM CELLS: are cells which are unspecialised cells that can develop into any type of cell if cultured under the right conditions. 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

13. Quick Check Give an example of how these cells can be used to treat illnesses. (Basic) Explain what is the difference between adult stem cells and embryonic stem cells. (Medium) Give an example of a specific type of treatment and why it needs embryonic or adult stem cells. (Harder)

14. Revision/& Test Can you fill in the missing gaps… Outcomes Assessment….. 1) 2) 3)

15. Mr Powell Lesson Outcomes… I will be able to give examples of how stem cells can be used to treat illnesses (Basic) I will be able to explain the differences between how adult stem cells and embryonic stem cells work. (Medium) I will be able to explain which type of stem cell is suitable for certain treatments and why. (Harder)

16. Groups 6 (Skin Cells) 5 (Skin Cells) 3 (Skin Cells) 4 (Skin Cells) 1 TL (Skin Cells) 2 (Skin Cells) 2 (Hair Cells) 4 (Hair Cells) 3 (Hair Cells) 1 TL (Hair Cells) 6 (Hair Cells) 5 (Hair Cells) 3 (Bone Marrow) 1 TL (Bone Marrow) 5 (Bone Marrow) 2 (Bone Marrow) 6 (Bone Marrow) 4 (Bone Marrow) 2 (Eye Cells) 6 (Eye Cells) 4 (Eye Cells) 1 TL (Eye Cells) 5 (Eye Cells) 3 (Eye Cells)

17. 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.