1 / 15

By: Mike Vieu, Katherine Munoz,

By: Mike Vieu, Katherine Munoz, Samah Najeeb, Ian Wenger. Definition.

tyra
Download Presentation

By: Mike Vieu, Katherine Munoz,

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. By: Mike Vieu, Katherine Munoz, Samah Najeeb, Ian Wenger

  2. Definition Stem cells are naturally occurring cells within the human body that have the potential to develop, or differentiate, into other types of cells with individual characteristics and specific functions

  3. Types of Stem Cell • Adult stem cells an undifferentiated cell, found among differentiated cells in a tissue or organ that can renew itself to yield some or all of the major specialized cell types of the tissue or organ • Embryonic stem cells as their name suggests, are derived from embryos in the blastocyst phase from an in vitro fertilization (IVF)clinic • Induced Pluripotent stem cells (iPSCs) adult cells that have been genetically reprogrammed to an embryonic stem cell–like state by being forced to express genes and factors important for maintaining the defining properties of embryonic stem cells.

  4. Background • Assumed to exist over 100 yrs. ago • 1908- Alexander A. Maximow • First to propose the term “Stem Cell” • First to hypothesize existence of hematopoietic stem cells • Let to more research in this field • 1961: Till & McCulloch establish the foundation for stem cell science. • 1964- scientists illustrated the presence of self-renewing cells in mouse bone marrow • 1974:  Congress Bans All Federally Funded Fetal Tissue Research • 1975:  Ethics Advisory Board Established • 1988:  Federal Panel Approves Funding of Embryo Research

  5. Adult Stem Cells • Exist throughout the body after embryonic development • Primary roles of adult stem cells in a living organism are to maintain and repair the tissue in which they are found • They remain in a non-dividing state for years, until activated by disease or tissue injury

  6. Embryonic Stem Cells • August 25, 2000: NIH Guidelines for Research Using Human Pluripotent Stem Cells. They stipulate: human embryonic stem cells must be derived with private funds from frozen embryos from fertility clinics; they must have been created for fertility treatment purposes; be in excess of the donor’s clinical need; and obtained with the consent of the donor. These guidelines also outlawed the federal funding of stem cells derived from embryos created by SCNT, even if the derivation took place with private funds. They are not derived from eggs fertilized in a woman's body • August 2001: President Bush Prohibits Federal Funding of Human Embryonic Stem Cell Research President Bush prohibits the federal funding of any research using stem cell lines derived after August 9, 2001, but his policy does not affect research in the private sector or research conducted with state funding. The president claims that more than 60 stem cell lines are available for funding. • August 24, 2012: Court upholds federal funding of embryonic stem cell research A senior US appeals court ruled on August 24, 2012 that the US National Institutes of Health (NIH) is legally able to fund research based on human embryonic stem cells. The decision was made by a three-judge panel of the US Court of Appeals for the District of Columbia Circuit and upholds a 2011 decision by a lower court, which found that the NIH’s funding of the research was legal despite a 1996 law (Dickey-Wicker Amendment), passed by Congress, which forbids funding research in which human embryos are destroyed. The NIH-supported research uses cell lines derived by destroying day-old embryos

  7. Potency of Stem Cells • Totipotent- differentiate into ALL possible cell types • Pluripotent- differentiate into all all cell types • Multipotent- differentiate into a closely related family of cells ex. Hematopoietic (adult) • Oligopotent- differentiate into a few cells ex. (adult) lymphoid or myeloid stem cell • Unipotent- produce cells of their own type ex. (adult) muscle stem cells

  8. Science ADULT STEM CELLS • Extracted from adult tissue • Found inside different types of tissue (brain, bone marrow, blood, blood vessels, skeletal muscles, skin, and the liver) • Placed into controlled culture, that prohibits specializing and differentiating

  9. SCIENCE EMBRYONIC STEM CELLS • Dividing zygote in a culture dish • The inner surface of the culture dish is typically coated with mouse embryonic skin cells that have been treated so they will not divide • Coating layer of cells is called a “feeder” layer • Release nutrients into the culture medium • Now able to grow embryonic stem cells without mouse feeder cells • This is a significant scientific advance because of the risk that viruses or other macromolecules in the mouse cells may be transmitted to the human cells • Cells that have increased in cell culture for prolonged period of time without differentiating, are pluripotenand have not developed genetic abnormalities are referred to as an embryonic stem cell line • Derived from 4-5 day old embryos that have been fertilized in vitro fertilization (blastocyst phase • Human embryonic stem cells (hESCs) are generated by transferring cells from a preimplantation-stage embryo into a plastic laboratory culture • If the At any stage in the process, batches of cells can be frozen and shipped to other laboratories for further culture and experimentation. • Easier to grow in large numbers and in a lab • Testing still needs time to further establish the realistic effectiveness of the relatively young science

  10. Treatment with Stem Cells • 1968- bone marrow transplant was successful between two siblings • First medical use of stem cells — and still the most common • Stem cells can “repair” and replace damaged cells • Used in some clinical trials to repair heart tissue • Repairing damaged or diseased tissues and curing such degenerative diseases as Alzheimer’s disease • January 25, 2012: Blindness eased by historic stem cell treatment Two people with eye degeneration both say their vision improved in the four months after they received implants of retinal pigment epithelial cells made from hESCs (human embryonic stem cells). The treatments were also safe, with no sign that the cells triggered aggressive tumours called teratomas, no sign of immune rejection of the cells, and no inflammation.

  11. Potential Stem Cell Uses • Possibilities to cure diseases, birth defects, medical conditions • Still in “studying phase”due to proper selection of the cells that are expected to have the greatest effect • Better understanding of cell and human development • Trials still continue today

  12. PROS • Therapies now available to treat a range of diseases and disorders Medical treatments (cancer to spinal cord injuries) • Understanding cells and cell life • Regenerate all areas of the body • Key to reversing the effects of aging and prolonging our lives • Mostly for the use of adult stem cells, neural stem cells, and cord blood stem cells • Help us all live longer, healthier lives

  13. Cons • Most cons deal with embryonic stem cell research • “Life begins at conception?” • High potential to divide characteristic if cancer • “Playing God”

  14. Ethics/Morality • Embryos are derived at 4-5 days • They are in the blastocyst phase (cells) • Embryos are usually “extras” that were created in the in vitro fertilization clinics • Fear of rejecting stem cells, have potential to lead away from stem cell research, into cloning • Nov 2011, Pope Benedict XVI spoke out in favor of adult stem cell research and called for any ensuing treatments to benefit all who need the care regardless of their financial means.

  15. Conclusion “Stem cell therapy is a constantly evolving research tool that involves the harvesting of pluripotential cells and the planting of those cells in the human body to regenerate damaged tissues, organs or body parts.” –Dr. Marcus Bethel

More Related