Stem Cells

Notes - “What’s the BIG DEAL?

What are stem cells?

*”Magic Seeds”

-Cells with the potential to be any kind of cell!

-Can divide without limit.

*Must be given the right chemical signal

Diagram Stem Cell Differentiation:

Fertilization/Zygote up to day 11. What is happening?

  1. Fertilization in the fallopian tube.

-Sperm meets Egg

  1. Zygote

-1 cell big

  1. Days 1 to 5

-Embryo divides over & over (Mitosis!)

*Sphere shaped “blastocyst” (150 cells big)

  1. Days 5 to 11 (Still a blastocyst)

-Embryonic stem cells are visible & capable of developing into any tissue in the body.

*Ideal to remove totipotent stem cells BUT it destroys the embryo in the process.

  1. Day 14

-The hollow mass of cells begins to change into three layers: the ectoderm, mesoderm & endoderm.

 The first 56 days of life is known as the “embryonic stage.”

Different Types of stem cells:

  1. Totipotent (Total Potential)

-Can become ANY type of cell in the body if given the correct “chemical message”

*Sources include: -Fertilized egg…Zygote

  1. Pluripotent (More Potential)

-Can become ALMOST ANY type of cell in the body except those needed to develop a fetus.

*Sources include: Blastocyst Embryonic Stem Cells from an embryo that is just a few days old or Fetal Stem Cells (after the 8th week of development.)

  1. Multipotent (Much Potential)

-Stem cells that can become a small number or limited range of different types of cells.

*Sources include: Umbilical Cord Blood and Adult Stem Cells

How can embryos be obtained?

-Embryos must be destroyed to get the stem cells.

  1. Fertility Clinics:

-Thousands of embryos are frozen in time with no intent to use.*Solution: Put these embryos up for adoption for an “opportunity to be born.”

Issue: How much respect does an embryo get?

  1. Aborted Fetuses:

-Women donated aborted fetuses.

Issue: Possible $ market or promoting an increase in abortions.

  1. Cloning:

-Human embryo “entities” may be cloned to produce more.

Issue: Possible $ market. *Massachusetts’s lab has already done this.

  1. Made to Order:

-Intentionally mix sperm and egg to create embryos as sources of stem cells.

Issue: Create life to destroy it? Should we profit from destroying human embryos? Considered the “Culture of Death.” *Virginia lab has already done this.

The BIG Debate: Should federal funds be used in research on discarded embryos?

“No”

  1. Stem cell research destroys living human embryos.
  2. Embryos are members of the human species from conception and have special moral status.
  3. There is a difference between embryos’ dying and actively killing them.
  4. It goes against the medical philosophy & practice of “do no harm.”
  5. It would desensitize society to the value of human life, which ultimately threatens vulnerable members in our society. (Such as “vegetables” or the old considered “biological remnants.”)
  6. It would increase a production of surplus embryos simply for research & profit.
  7. “Parents do not have the moral right to consent to the destruction of the human embryo any more than to the destruction of their own children.”
  8. Alternative sources of stem cells are not immoral and should be pursued.

“Yes”

  1. The “promise” of curing incurable diseases out ways any negative.
  2. There is a great potential for growing replacement organs & tissues. (Huge need.)
  3. Federal funding means that research is regulated.
  4. Stem cell research may also help prevent specific disease because of the knowledge gained about differentiation and what can go wrong.
  5. “AMA” (American Medical Association”) supports the research.