Various cells
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Various cells. General green plant cell. Paramecium. Amoeba. Rod shaped bacterial cells. Cell specialization. A complex, multicellular organism such as yourself is composed of various specialized cells.

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Various cells

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Various cells

Various cells

General green plant cell

Paramecium

Amoeba

Rod shaped bacterial cells


Cell specialization

Cell specialization

  • A complex, multicellular organism such as yourself is composed of various specialized cells.

  • The estimated three trillion cells that make us up are kinda all the same, but then again, they aren’t. Huh??

  • Every cell in our body has the same overall cell anatomy. Every cell has the same copy of DNA or instruction manual on how we operate.

  • However, every cell does not have to produce every protein or product needed for the cell to run smoothly. Every cell doesn’t have to perform every job.

  • Cells will differentiate and become specialized focusing on producing certain products and performing one task really well


A few cells found in humans

A few cells found in humans

Nerve cell (neuron)

Erythrocyte (red blood cell)

Macrophage (white blood cell

Muscle cell (skeletal)

Embryonic stem cell from blastocyst


What are stem cells

What are stem cells?

  • Stem cells are undifferentiated or unspecialized cells yet to develop into a specific type of body (somatic) cell.

  • Stem cells differentiate (turn) into the specialized cells of the body.

  • Think of a stem cell as a “blank” cell that will eventually turn into a specific cell of the body


Types of stem cells

Types of stem cells

  • Embryonic stem cell--the time from conception (sperm fertilizing egg) to about 10 weeks is the embryonic stage

  • Fetal stem cells--After 10 weeks the organism is considered a fetus

  • Adult stem cells—stem cells found in an adult or living human


Conception

Conception

  • Totipotent—a stem cell’s ability to turn into ANY body cell

  • At conception when the sperm fertilizes the egg, the zygote or first cell is considered totipotent because it has the ability to turn into cell in the body

  • Embryonic stem cells are totipotent up to 4 days after fertilization when they then become pluripotent


Embryology

Embryology


Embryonic stem cells

Embryonic stem cells

  • Pluripotent= can differentiate into the vast majority of any body cell type

  • Taken from the blastula stage in development

  • Derived from embryos that develop from eggs that have been fertilized in vitro and then donated for research purposes with informed consent of the donors

  • NOT, NOT, NOT derived from eggs fertilized in a woman's body (abortion)


Major misconception

Major misconception!!

  • Embryonic stem cells are not taken from aborted fetuses or extracted from a mother’s womb.

  • They have come from unused fertilized eggs from fertility clinics


Adult stem cells

Adult stem cells

  • Multipotent= can form into some cells of the body including neural, skeletal, and cardiac tissue

  • Ex. Multipotent blood stem cells turn into red blood cells, white blood cells, and platelets

  • The primary location of adult stem cells is in bone marrow. However, they have also been found in:

    • Brain

    • Blood vessels

    • Digestive tract

    • Skeletal muscle

    • Skin

    • Liver

    • Umbilical cord


What do we want to do with stem cells

What do we want to do with stem cells?

  • Because stem cells can differentiate or turn into various specialized cells of the body, researchers are trying to use stem cells to cure disease.

  • It seems logical to assume that stem cell therapy could be used to repair damaged or diseased tissues or organs.


Various cells

Adult Stem Cell Therapies

Clinical Uses of Adult Stem Cells:

  • Cancers (leukemia, lymphomas)

  • Multiple Sclerosis

  • Sickle Cell anemia

  • Heart disease

  • Diabetes

  • Parkinson’s disease

  • Many more. . .

    Clinical Uses of Embryonic Stem Cells:

  • ?? Limited due to past governmental restrictions

Ethically obtained adult stem

cells from blood, fat cells, nerves, bone marrow are triggered to become new tissues to treat disease.


Adult stem cell research one of many success stories

Adult Stem Cell ResearchOne of Many Success Stories

60 Minutes II: Holy GrailJune 5, 2002Stem cells are thought of as the Holy Grail of medicine. One young boy agrees with that. He made medical history because he's been cured of his life-threatening disease. The key to his cure did not come from a human embryo, where all the controversy is, but from something that is routinely tossed in the garbage - an umbilical cord. Umbilical cords were always considered medical waste. Not anymore.

Full story:

http://www.cbsnews.com/stories/2001/11/28/60II/main319351.shtml

June 12 2003. Keone Penn, cured of sickle-cell anemia by stem cells from umbilical cord blood, testifies before a U.S. Senate committee about successes in adult stem cell research.


Not a complete science yet

Not a complete science yet

  • Posted on Wed, Dec. 01, 2004

  • New research undercuts promise of adult stem cells

  • BY PETER GORNERChicago Tribune

  • CHICAGO - (KRT) - Researchers reported Wednesday that bone marrow stem cells were unable to regenerate damaged heart tissue in laboratory animals, suggesting that a proposed revolutionary therapy for the 1.1 million Americans who suffer heart attacks each year may be destined to fail.

  • The study is the latest to cast doubts on the scientific dream that a patient's own mature stem cells - instead of stem cells from embryos - could someday be used to replace cells damaged or missing because of genetic diseases, tissue injuries or degenerative illnesses.


Federal policy on stem cells

Federal Policy on Stem Cells

  • Currently, embryonic and adult stem cell research can occur.

  • Former President Bush limited embryonic research to a minimum, however, President Obama has increased embryonic research efforts

  • Embryonic stem cells are only used from in-vitro fertilizations with informed consent


The debate the stem cell debate really centers on embryonic research and the ethics involved in it

The DebateThe stem cell debate really centers on embryonic research and the ethics involved in it

  • Should there continue to be current research into using embryonic stem cell therapies?

  • Should our nation increase research into embryonic stem cells by using more cell lines (in vitro cell lines)?

  • Should we stop embryonic stem cell research completely and focus on adult stem cell research?

  • If we oppose embryonic stem cell research, should we also discontinue in-vitro fertilizations that allow some couples to have families?

  • Should we stop all stem cell research and quit messing with natural outcomes?


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