GLOSSARY* 
Adipose tissue: A type of connective tissue that stores fat. 
Adult stem cell: An undifferentiated cell found in a differentiated 
tissue that can renew itself and (with certain limitations) differenti- 
ate to yield all the specialized cell types of the tissue from which it 
originated. (NIH) 
Allogeneic cell transplantation: Transplantation of cells from one 
individual to another of the same species. 
Amniotic fluid: Fluid that fills the innermost membrane, the amnion, 
that envelopes the developing embryo or fetus. 
Amnion: Innermost of the extra-embryonic membranes enveloping 
the embryo in utero and containing the amniotic fluid. (SMD) 
Aneuploid: Having an abnormal number of chromosomes. (SMD) 
Angiogenesis: Development of new blood vessels. (SMD) 
Antigen: A substance that, when introduced into the body, stimu- 
lates the production of protein molecules called antibodies that can 
bind specifically to the substance. 
Astrocyte: A type of nerve cell that has supportive and metabolic 
functions rather than signal conduction. 
Autologous: In transplantation, referring to a graft in which the do- 
nor and recipient areas are in the same individual. (SMD) 
* 
Definitions marked "(CR)" are from the Council’s report on human cloning {Human 
Cloning and Human Dignity: An Ethical Inquiry, Washington, D.C.: Government Print- 
ing Office, 2002). Definitions marked "(NIH)" are from the National Institutes of Health 
on-line stem cell glossary at http://stemcells.nih.gov (accessed September 5, 2003). 
Definitions marked "(NRC)" are from the National Research Council report. Stem Cell 
Research and the Future of Regenerative Medicine (Washington, D.C.: National Re- 
search Council, 2001). Definitions marked "(SMD)" are from Stedman’s Medical Dic- 
tionary. 
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