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Final

Final. Tuesday Dec 18 7:00 PM 1245 SC Same format. Stem Cell Research: Overview of technical, legal, and ethical considerations.

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Final

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  1. Final • Tuesday • Dec 18 • 7:00 PM • 1245 SC • Same format

  2. Stem Cell Research:Overview of technical, legal, and ethical considerations Disclaimer: I will attempt to neither promote nor advocate stem cell research -- but only provide knowledge about the process and raise awareness about relevant issues. You are adults, you can make up your own minds.

  3. Question?

  4. Stem Cell Research • Technical overview • Legal issues • Ethical issues

  5. Stem Cell Research: Why • Every year -- millions of people suffer, and eventually die from incurable degenerative diseases • Parkinson's, multiple sclerosis, stroke, heart disease, liver disease, pancreas (diabetes), and other organs (retina) • it is hypothesized that stem cell research is the current best avenue to alleviate, or even cure some of these diseases

  6. Stem Cells: What? • fetal stem cells (and adult stem cells) • multipotent -- capable of generating many different cell types • pluripotent -- capable of generating all different cell types • available in only small numbers • do not provide a realistic approach to cell therapy of common degenerative diseases unless they could be greatly amplified in culture • formidable scientific and clinical challenges must be overcome • how to direct pluripotent ES cells to differentiate into the require cell or tissue

  7. Sources of stem cells • stem cells • can be harvested from embryos, adults (living or dead), fetuses • derived from the transfer of a somatic cell nucleus (somatic cell nuclear transfer -- SCNT) into an oocyte from which the nuclear material has been removed • note: bone-marrow transfusions, blood transfusions, organ transplantation is widely practiced and regulated

  8. Human Stem Cells • derived from: • developing fetal tissue (embryonic germ -- EG cell lines) • early "pre-implantation" embryos (no longer required for infertility treatments -- ES cell lines -- and commonly discarded) • less is known about EG cell lines • there is some concern that the altered methylation status of the germ cell lineage might affect therapeutic value

  9. Somatic-cell nuclear cloning for therapeutic purposes

  10. Stem Cells: Legal?

  11. US Policy • In principle, it should be possible for much clinically valuable research to be carried out using the relatively few human pluripotent stem cell lines that have been derived so far. • basis for US policy proposed by George Bush in 2001 -- 64 ES cell lines in existence • Stem cell research in the US cannot be supported by federal money • Also, reproductive cloning is illegal (and confusing) • has since been determined that only about 10 lines are viable • may be unduly restrictive • extent of distribution of cell lines is limited by issues involving patents, commercial secrecy, and restrictive material transfer agreements.

  12. Ethical Dilemmas

  13. Observations • elective termination of pregnancy is considered ethically unacceptable by some (i.e. pro-choice/pro-life) • however, some also consider the use of an aborted fetus for research or treatment as acceptable (which may or may not require special conditions)

  14. More observations • some believe that the human embryo from the one-cell stage onwards has absolute moral value • equal to a newborn baby or an adult • therefore, embryo research is ethically unacceptable, and is tantamount to murder

  15. More observations • Alternatively, some believe that moral value develops gradually • "that status as a person or as an entity with interests requires, at the very least, a nervous system capable of sentience, if not also a cognition and consciousness. The neural development that is essential to have inherent moral status and interest in one's own right is not present in the undifferentiated cells of preimplantation embryos…Because of the preimplantation embryo's rudimentary state of development, removing ES cells from the inner cell mass of human blastocysts does not wrong them, and so should be permitted."

  16. Embryos • Denial of the early embryo's inherent moral status and correlative duty not to destroy embryos does not however mean that the human embryo is perceived as without value. • Or that it may be treated like an excised tissue. • Some reject the view that the embryo is a person but believe that the embryo is different from ordinary human tissue because of the unique potential it has to develop into a new human being • This attitude towards human embryos shows or symbolizes our respect for human life generally

  17. A contextual shift • "In the context of in vitro fertilization treatment, the generation of more embryos than can be safely transferred to the uterus is widely accepted as not being unduly disrespectful of human life, because it enables children to be born to infertile couples."

  18. Summary • Major technical issues for cell therapy remain • Without continued stem cell research -- these hurdles cannot be overcome • Differences in opinion on the definition of life, when life begins, and the beliefs to protect life has great influence in the debate (both for and against)

  19. References • McLaren. "Ethical and social considerations of stem cell research." Nature, v414, 129, 2001 • Robertson. "Human embryonic stem cell research: ethical and legal issues." Nature Reviews, V2, 74, 2001 • Childress. "Human stem cell research: some controversies in bioethics and public policy." Blood Cells, Molecules, and Diseases. 100-105, 2004

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