Stem Cells Flashcards
Describe the characteristics that a cell must have to be classified as a stem cell.
- Ability to differentiate into specialized tissues in the body
- Ability to continue to divide continuously in culture
- Has to be able to divide and produce more cells like itself and it has to be able to differentiate to produce more specialized cell types.
What are some goals of stem cell research? What do scientists hope to be able to do some day?
Knowledge about processes of development and differentiation may allow us to learn how hear disease, cancer, birth defects, etc. develop and may help us better treat or prevent these.
Therapy: May allow physicians to repair and/or regenerate damaged tissues and organs.
Testing drugs.
Distinguish between adult and embryonic stem cells. How is each type obtained?
Adult: More limited as to types of tissues they can become (multipotent).
- Umbilical cord at delivery
- Bone marrow of an adult
- Some adult cells
Embryonic: Have potential to differentiate into many/most (Pluripotent, not Totipotent) tissue types.
- From blastocyst of early embryo
What is somatic cell nuclear transfer? Describe the procedure.
Therapeutic cloning that uses patient’s cell so should be compatible with patient.
Nucleus is removed from both egg cell and body cell,
nucleus from the body cell inserted into egg cell,
cloned cell induced to form an embryo,
stem cells harvested from embryo cells.
What is meant by totipotent, multipotent, pluripotent? Which term is appropriate in describing adult stem cells? Which is appropriate for embryonic stem cells?
Totipotent cells can form all the cell types in a body, plus the extraembryonic, or placental, cells. Embryonic cells within the first couple of cell divisions after fertilization are the only cells that are totipotent. Pluripotent cells can give rise to all of the cell types that make up the body; embryonic stem cells are considered pluripotent. Multipotent cells can develop into more than one cell type, but are more limited than pluripotent cells; adult stem cells and cord blood stem cells are considered multipotent.
Adult stem cells: Multipotent
Embryonic stem cells: Pluripotent
What are induced pluripotent cells? Why are they important in medicine and research?
A new technique for creating stem cells without the controversial use of human eggs or embryos.
Skin cells are removed, then retroviruses are used to inject the skin cells with four genes. The genes somehow reprogram the cells to become stem cells.
Who received the Nobel Prize in the category Physiology or Medicine in 2012? Describe their research.
John B. Gurdon: 1962 discovered that a specialized cell still had all the genetic information needed to develop all cells in a mature organism.
Shinya Yamanaka: In 2006 determined that the insertion of 4 genes could reprogram differentiated cells and cause them to become pluripotent stem cells.
Discuss some of the controversial/ethical issues regarding stem cell research. What types of stem cells do these issues refer to?
- Fetal origin and right to life
- Tampering with God’s plan
- Fear of going too far
- Can get adult stem cells from lots of tissues so are embryonic stem cells really needed? Or will we need the embryonic stem cells to make all the cell types we need?
- Other countries do not have the regulations we have. Will we lag behind in this technology? What will that mean for our citizens?
Types: Embryonic stem cells
Discuss the historical and current state of federal regulations on stem cell research.
- Federal funding is available for adult stem cell research.
- In 2001, Pres. Bush issued and order that allowed federal funding for embryonic stem cell research on cell lines developed before August 9, 2001, but not on more newly developed ESC lines.
- March 9, 2009: Pres. Obama issued an order that allowed federal funding would be allowed for those newly developed lines, and that National Institute of Health would be allowed to set the regulations for ESC use.
- July 7, 2009: NIH published guidelines for Human Stem Cell research.
- September 21, 2009: NIH opened their website to accept requests for human embryonic stem cell line approvals for ESC lines.
- December 2009: NIH approved first ESC line under new guidelines.
- August 2010: District Judge Lamberth issued a preliminary order barring federal funding for new stem cell lines say that funding violated federal law since it required destruction of human embryos.
September 2010: Appeals court said it could continue for now. - Still going on…
Which organization set the current regulations for ESC funding?
National Institute of Health
Does NC allow embryonic stem cell research? Adult stem cell research?
Yes
Yes
