1. Advanced Placement Biology and Stem Cells Click on the cartoon above for a tutorial on Stem Cells The Nature of Stem Cells and Embryology

2. What is a Stem Cell? A cell that has the ability to continuously divide and differentiate (develop) into various other kind(s) of cells/tissues Stem cells are different from other cells of the body in that they have the ability to differentiate into other cell/tissue types. This ability allows them to replace cells that have died. With this ability, they have been used to replace defective cells/tissues in patients who have certain diseases or defects.

3. Stem Cell Applications Tissue repair  nerve, heart, muscle, organ, skin  Regenerate spinal cord, heart tissue or any other major tissue in the body. Cancers  Studies show leukemia patients treated with stem cells emerge free of disease  Injections of stem cells have also reduces pancreatic cancers in some patients. Autoimmune diseases  diabetes, rheumatoid arthritis, MS

4. Click on the picture to watch a video on the skin shooter Replace Skin

5. Kinds of Stem Cells Stem cell type DescriptionExamples Totipotent Each cell can develop into a new individual Cells from early (1-3 days) embryos Pluripotent Cells can form any (over 200) cell types Some cells of blastocyst (5 to 14 days) Multipotent Cells differentiated, but can form a number of other tissues Fetal tissue, cord blood, and adult stem cells

6. Illustration by Matt Bohan, 2007 Embryonic Stem cells are obtained from In-Vitro Fertilization embryos that were not used - http://www.news.wisc.edu/packages/stemcells/illustration.html

7. This cell Can form the Embryo and placenta This cell Can just form the embryo Fully mature

8. EMBRYONIC STEM CELLS Blastocyst http://stemcells.nih.gov/info/basics/ "Image courtesy of NIH resource for stem cell research" http://en.wikipedia.org/wiki/Image:Blastocyst_English.svg

9. Umbilical Cord Stem Cells Also Known as Wharton’s Jelly Adult stem cells of infant origin Less invasive than bone marrow Greater compatibility Less expensive

10. Skin Fat Cells Bone marrow Brain Many other organs & tissues Adult Stem Cells An undifferentiated cells found among specialized or differentiated cells in a tissue or organ after birth

11. Umbilical Cord Stem Cells Three important functions: 1.Plasticity: Potential to change into other cell types like nerve cells 2.Homing: To travel to the site of tissue damage 3.Engraftment: To unite with other tissues

12. STEM CELLS HAVE ALSO BEEN FOUND IN “MATURE” ORGANS Illustration by Matt Bohan, 2007

13. Differences between embryonic stem cells and adult stem cells They have different self-renewal capabilities –Embryonic stem cells: near indefinite self-renewal –Adult stem cells: limited self-renewal They have different differentiation potentials –.Embryonic stem cells: differentiate into all cell types in an organism –Adult stem cells: differentiate into restricted cells types. They differ in how they respond to external stimuli –Embryonic stem cells are readily to change upon stimulation –Adult cells emphasize on stability and need to be activated by cues, e.g. injuries.

14. PROS AND CONS OF EACH TYPE EMBRYONIC –CELL LINES LAST AND LAST AND LAST –MULTIPOTENT –EASY TO FIND –ETHICAL ISSUES - WHEN DOES LIFE BEGIN? ADULT –CELL LINES DO NOT LAST –NOT MULTIPOTENT –HARD TO LOCATE –NO ETHICAL ISSUES

15. Why the Controversy Over Stem cells? Embryonic Stem cells are derived from extra blastocysts that would otherwise be discarded following IVF. Extracting stem cells destroys the developing blastocyst (embryo). -Questions for Consideration- Is an embryo a person? Is it morally acceptable to use embryos for research? When do we become “human beings?”

16. People in the US affected by diseases that may be helped by stem cell research ConditionNumber of Persons Affected Cardiovascular diseases58 Million Autoimmune diseases30 Million Diabetes16 Million Osteoporosis10 Million Cancer8.2 Million Alzheimer's disease4 Million Parkinson's disease1.5 Million Burns (severe)0.3 Million Spinal cord injuries0.25 Million Birth defects150,000 (per year) Total 128.4 Million -------------------------------------------------------------------------------------- Data from the Patients' Coalition for Urgent Research, Washington, DC (according to Perry, Ref. 267).

17. How can scientists ensure ethical conduct in stem cell research Education for researchers –Routine emphasis by principle investigators –Emphasis by funding agencies –Classes and seminars Education for the public –Understand the importance of research –Understand that scientists are under ethical guidance Communication and open dialogue –Understand each others’ opinion –Reach a rationale common ground. Last step: Legal reinforcement

18. Useful Resources National Institute of Health resource for stem cells (http://stemcells.nih.gov) International Society for Stem Cell Research: “Guidelines for the Conduct of Human Embryonic Stem Cell Research (www.isscr.org)” National Academy of Science: “Guidelines for human embryonic stem cell research” (http://www.nap.edu/openbook.php?isbn=0309096537)