stem cell research

Views:
 
     
 

Presentation Description

stem cell reserach still needs to be developed to perfection to help the mankind

Comments

Presentation Transcript

Stem cell research : 

4/25/2010 Stem cell research Dr.Veerendra Kumar C.M. MD.,DNB. Associate Professor VIMS,Bellary veerendrakumarcm@gmail.com

Slide 2: 

4/25/2010 VIMS

Human suffering… : 

4/25/2010 Human suffering…

Slide 4: 

4/25/2010 Totipotent Pluripotent Multipotent Oligopotent

What are stem cells? : 

4/25/2010 What are stem cells? Self renewal in undifferentiated state Potencyto develop into different cells

Regenerative medicine : 

4/25/2010 Regenerative medicine Study of early human development Therapeutic tool for various diseases Develop and test new therapies

hESC (human embryonic stem cells) : 

4/25/2010 hESC (human embryonic stem cells) To study drug toxicity- liver cells & cardiomyocytes derived from SC- useful to study drug toxicityDavila ,Toxico Sci 2004;79:214-23

Types of stem cells : 

4/25/2010 Types of stem cells Adult Embryonic Adult - Bone marrow, Cord blood Embryonic - Unused IVF embryos Pregnancy terminations

Slide 9: 

4/25/2010 Embryonic V/S adult stem cells

Embryonic stem cells (ESC) : 

4/25/2010 Embryonic stem cells (ESC) Embryonic cells are pluripotent and virtually immortal.

Fetuses from pregnancy terminations : 

4/25/2010 Fetuses from pregnancy terminations Their ability to renew themselves is limited. Animal studies have shown that it is more difficult to produce normal tissues from these cells.

Adult stem cells : 

4/25/2010 Adult stem cells A person’s own stem cells should be the best source of cells for transplantation. Adult stem cells will eventually substitute for embryonic stem cells.

Umbilical cord stem cells : 

4/25/2010 Umbilical cord stem cells

Adult Stem Cells and Postnatal Stem Cells : 

4/25/2010 Adult Stem Cells and Postnatal Stem Cells Advantages No ethical controversy. None to minimal risk of immune rejection. Reduced cost and time. Genetic stability. Potential disadvantage ?Limited plasticity ?Limited lifespan in culture, may carry defective gene

FDA TRIALS USING ADULT OR CORD BLOOD STEM CELLS : 

4/25/2010 FDA TRIALS USING ADULT OR CORD BLOOD STEM CELLS >70 current human clinical applications using adult stem cells there are no current human clinical trials involving human embryonic stem cells “It is nearly certain that the [human] clinical benefits of the [embryonic stem cell] research are years or decades away. This is a message that desperate families and patients will not want to hear.” — Science, June 17, 2005

Slide 16: 

4/25/2010

Debate over hESC : 

4/25/2010 Debate over hESC

Objections and concerns.. : 

4/25/2010 Objections and concerns.. An embryo should be accorded full human status from the moment of its creation A first step on a ‘slippery slope’ towards human reproductive cloning.

Conservative vs. Liberal : 

4/25/2010 Conservative vs. Liberal Conservative = Literal Translation of the Bible Liberal = Compromising Translation of Bible

Question to consider: : 

4/25/2010 Question to consider: Is it ethical to delay research using embryonic stem cells until adult stem cells are fully capable of treating any disease?

Stem Cell Cultivation : 

4/25/2010 Stem Cell Cultivation University of Wisconsin-Madison

Somatic Cell Nuclear Transfer (SCNT) technique used in ‘CLONING’May be ethically acceptable as you are not using embryos by conventional methods : 

4/25/2010 Somatic Cell Nuclear Transfer (SCNT) technique used in ‘CLONING’May be ethically acceptable as you are not using embryos by conventional methods

Novel methods : 

4/25/2010 Novel methods Extraction of single blastomere without damaging embryo and developed into independent hESC lines Chung et al ,Nature 2006; 439:216-19 Altered Nuclear Technique (ANT)genetically modifying the somatic nucleus so that induced pluripotent stem cells are producedmeissener & Jaenisch Nature 2006;439:212-15

First clinical trial using hESC : 

4/25/2010 First clinical trial using hESC GERON Co, 2005-2006 Aldhous, Nature 2005;434:94-6

Existing lines of hESC : 

4/25/2010 Existing lines of hESC 414 lines are available in 20 countries Characterization of these lines is limited- only 49% of lines are published in peer reviewed journals Guhr et al Stem cells 2006;24:2187-91

Derivation of hESC : 

4/25/2010 Derivation of hESC Frozen embryos from IVF cycleExpanded blastocyst – ICMimmunosurgical isolation Quality poor-2nd quality embryos-cryoppreservation damages Simon et al Fertil Steril 2005;83:246-9

Maintenance of hESC : 

4/25/2010 Maintenance of hESC Immortal cells in undifferentiated state Optimal growth conditions for future therapeutic applications Majority of hESC have been isolated and maintained in fetal calf serum and mouse embryonic fibroblasts as feeder cell layers (Xenoproteins and xenosupports)

Problems : 

4/25/2010 Problems Transmission of interspecies virus transfer Incorporation of foreign sugar molecule to hESC leading to immune response It may also lead to impairment of cell function & tissue development Varki Am J Phys Anthropol Suppl 2001

Research focus is on…. : 

4/25/2010 Research focus is on…. Use of human components instead of animal sources to avoid zoonosis Fetal, adult muscle tissue, skin, Fallopian tube, endometrium, foreskin cells Successful undifferentiated growth of hESC using xenobiotic –free feeder system Richards ,Stem cells 2003;21:546-56

Research focus is on… : 

4/25/2010 Research focus is on… Feeder free culture system from recombinant sources Ludwig Nature Biotech 2006;24:185-7

Differentiation : 

4/25/2010 Differentiation Direct hESC to differentiate into specific cell lines - drug development- cell replacement therapeutics Specific germ cell layers can be directed by adding specific growth factors

Scientific Stem Cell Challenges : 

4/25/2010 Scientific Stem Cell Challenges Stem cells represents a very small fraction of cells in tissue. Isolate a small number of stem cells (finding a needle in a haystack). Expand the number of stem cells for research and clinical applications. Maintain genetic stability in culture and in recipient. Culture media has to be free of animal protein. Deliver cells to tissue of interest. Stem cells have to be functional. Avoid or restrict tissue rejection.

Challenges to Stem Cell/Cloning Research : 

4/25/2010 Challenges to Stem Cell/Cloning Research differentiation to the appropriate cell type(s) before using clinically. Recently, chromosome abnormalities in three human ESC lines.

Challenges to Stem Cell/Cloning Research : 

4/25/2010 Challenges to Stem Cell/Cloning Research Stem cell development or proliferation must be controlled once placed into patients. Possibility of rejection of stem cell transplants as foreign tissues is very high.

Beware : 

4/25/2010 Beware Private companies promising wonders with stem cells - mostly in countries with unregulated lawsIlic D, Regenerative med 2006;1:1-4 UKRAINE –capital of ESC ? but the references they quote do not have international authenticity in peer reviewed journals

Slide 36: 

4/25/2010

Slide 37: 

4/25/2010

authorStream Live Help