Microsoft Word Kurzweil, Ray The Singularity Is Near doc

Smithsonian
, June 2003, 
http://www.smithsonianmag.com/smithsonian/issues03/jun03/phenomena.html. 
61.
J. B. Gurdon and A. Colman, "The Future of Cloning," 
Nature
402.6763 (December 16, 1999): 
743–46; Gregory Stock and John Campbell, eds., 
Engineering the Human Germline: An 
Exploration of the Science and Ethics of Altering the Genes We Pass to Our Children
(New York: 
Oxford University Press, 2000). 
62.
As the Scripps Research Institute points out, "The ability to dedifferentiate or reverse lineage-
committed cells to multipotent progenitor cells might overcome many of the obstacles associated 
with using ESCs and adult stem cells in clinical applications (inefficient differentiation, rejection of 
allogenic cells, efficient isolation and expansion, etc.). With an efficient dedifferentiation process, it 
is conceivable that healthy, abundant and easily accessible adult cells could be used to generate 
different types of functional cells for the repair of damaged tissues and organs" 
(http://www.scripps.edu/chem/ding/sciences.htm) . 
The direct conversion of one differentiated cell type into another—a process referred to as 
transdifferentiation—would be beneficial for producing isogenic [patient's own] cells to 
replace sick or damaged cells or tissue. Adult stem cells display a broader differentiation 
potential than anticipated and might contribute to tissues other than those in which they reside. 
As such, they could be worthy therapeutic agents. Recent advances in transdifferentiation 
involve nuclear transplantation, manipulation of cell culture conditions, induction of ectopic 
gene expression and uptake of molecules from cellular extracts. These approaches open the 
doors to new avenues for engineering isogenic replacement cells. To avoid unpredictable tissue 
transformation, nuclear reprogramming requires controlled and heritable epigenetic 
modifications. Considerable efforts remain to unravel the molecular processes NOTES 557 
underlying nuclear reprogramming and evaluate stability of the changes in reprogrammed 
cells. 
Quoted from P. Collas and Anne-Marl Hakelien, "Teaching Cells New Tricks," 
Trends in 
Biotechnology
21.8 (August 2003): 354–61; P. Collas, "Nuclear Reprogramming in Cell-Free 
Extracts," 
Philosophical Transactions of the Royal Society of London
, B 358.1436 (August 29, 
2003): 1389–95. 
63.
Researchers have converted human liver cells to pancreas cells in the laboratory: Jonathan Slack et 
al., "Experimental Conversion of Liver to Pancreas," 
Current Biology
13.2 (January 2003): 105–15. 
Researchers reprogrammed cells to behave like other cells using cell extracts; for example, skin 
cells were reprogrammed to exhibit T-cell characteristics. Anne-Mari Hakelien et al., 
"Reprogramming Fibroblasts to Express T-Cell Functions Using Cell Extracts," 
Nature 
Biotechnology
20.5 (May 2002): 460–66; Anne-Mari Hakelien and P. Collas, "Novel Approaches 
to Transdifferentiation," 
Cloning Stem Cells
4.4 (2002): 379–87. See also David Tosh and Jonathan 
M. W. Slack, "How Cells Change Their Phenotype," 
Nature Reviews Molecular Cell Biology
3.3 
(March 2002): 187–94. 
64.
See the description of transcription factors in note 21, above. 
65.
R. P. Lanza et al., "Extension of Cell Life-Span and Telomere Length in Animals Cloned from 
Senescent Somatic Cells," 
Science
288.5466 (April 28, 2000): 66–9. See also J. C. Ameisen, "On 
the Origin, Evolution, and Nature of Programmed Cell Death: A Timeline of Four Billion Years," 

---