Download - Stem Cell Research
![Page 1: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/1.jpg)
Stem Cell Research
Embryonic stem cell research will prolong life, improve life ad give hope for life to millions of people.
-Jim Ramstad
![Page 2: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/2.jpg)
What are they?
• Stem cells are undifferentiated cells.
• They can differentiate into specialized cells.
• They can divide (through mitosis) to produce more stem cells.
• They are found in multicellular organisms. In mammals.
• This slide shows an adult stem cell
![Page 3: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/3.jpg)
Stem Cell Types
• In mammals, there are two types of stem cells.
• Embryonic stem cells, which are isolated from the inner cell mass of blastocysts.
• Adult stem cells, which are found in various tissues.
![Page 4: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/4.jpg)
Repair System
• In adult organisms, stem cells act as a repair system for the body, replenishing adult tissues.
• This cross section of skeletal muscle fibers shows the small satellite cells.
• If the muscle fiber is damaged the satellite cells will reproduce and differentiate into muscle tissue and repair the damaged area.
![Page 5: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/5.jpg)
Adult stem cells
• Three easy sources.• Bone marrow, which is
extracted by harvesting, that is, drilling into bone (typically the femur or iliac crest).
• Adipose tissue (lipid cells), which requires extraction by liposuction.
• Blood, which requires extraction through pheresis, wherein blood is drawn from the donor (similar to a blood donation), passed through a machine that extracts the stem cells and returns other portions of the blood to the donor.
![Page 6: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/6.jpg)
Bone Marrow transplant
• Bone marrow contains multipotent stem cells.
• These cells can become RBC’s, WBC’s or platelets.
• The marrow can be harvested from a healthy donor and transfused into a patient with leukemia.
![Page 7: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/7.jpg)
Spray on Skin
• Some healthy skin stem cells (unipotent – keratinocytes or fibrocytes) are mixed with water.
• The solution is sprayed on the burn or damaged area.
• The cells divide and produce new skin within days.
![Page 8: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/8.jpg)
This young toddlers second degree burns were healed with the spray on skin technique.
![Page 9: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/9.jpg)
Autologous stem cells• Stem cells can also be
taken from umbilical cord blood just after birth.
• Of all stem cell types, autologous harvesting involves the least risk.
• Autologous cells are obtained from one's own body.
• A person can save his or her own stem cells in the same way they can save their own blood.
![Page 10: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/10.jpg)
![Page 11: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/11.jpg)
The case for Embryonic stem cells
• The most potent stem cells are the embryonic stem cells taken from the blastocyst stage.
• These cells have the capability of differentiating into any tissue cell.
• They are also ideal in that they keep replicating indefinitely.
• There are over 300 existing human embryonic stem cell lines available in the world; about two-thirds of these are in just five countries: UK, Sweden, France, Spain, USA
![Page 12: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/12.jpg)
Harvesting Embryonic Stem Cells
• In vitro fertilization generates multiple embryos.
• Some of the embryos are not clinically used or are unsuitable for implantation into the patient.
• These embryo’s may be donated by the donor with consent.
• Human embryonic stem cells are derived from these donated embryos that would otherwise be discarded.
![Page 13: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/13.jpg)
![Page 14: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/14.jpg)
Ethical objections
• Some people feel that it isn’t right to kill an embryo, even if it is going to be discarded, to obtain stem cells.
• They feel that once an egg is fertilized it is a distinct human life.
• This feeling has resulted in a moratorium on federal funding for embryonic stem cell research.
![Page 15: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/15.jpg)
Chimeras
• Chimeras are organisms that contain cells or tissues from more than one organism.
• For example human stem cells can be transplanted into mice to make sure that the tissues that develop will function. (pancreatic cell research for diabetes).
• New therapies need to be tried on animals before humans.
• Some worry about a chimera with human consciousness or introducing human stem cells into a primate (chimp).
![Page 16: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/16.jpg)
Human Chimerism
• This happens when two separate, fertilized eggs fuse to form one embryo.
• This results in an organism with intermingled cell lines.
• This person may have a liver with one set of chromosomes and a kidney with another.
• Most never now their situation.
• They may have different eye colors, faint marks on the back, or differential hair growth
![Page 17: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/17.jpg)
Cloning
• Cloning and stem cell research are linked with a technique called Nuclear transfer.
• Scientists can transfer a nucleus from an adult stem ceel into an ovum or egg whose nucleus has been removed.
• This would result in identical genetic matches leading to safer tissue transplants.
• The fear of a lab growing a complete person has led to the practice being outlawed.
![Page 18: Stem Cell Research](https://reader036.vdocument.in/reader036/viewer/2022062315/56815eeb550346895dcd9fea/html5/thumbnails/18.jpg)
Mammoth• Recently a well preserved 10,000 year old frozen mammoth was discovered.
• It has been proposed to take stem cells from the mammoth and implant the nucleus into an elephant egg.
• Repeat the process over time and eventually you would have a mammoth!