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Monitoring Stem Cell Research 
has been used extensively in studies regarding spinal cord injury and 
axon regrowth. Human OEG cells can be expanded in number in 
culture and induced to produce all three main neural cell types. 
Transplant of the cells into animal models of spinal cord injury has 
shown that the cells can effect remyelination of demyelinated spinal 
cord axons,”'* and provide functional recovery in paraplegic rats,”^ 
including in transected spinal cords.”® Another study has foimd that 
infusion of growth factors such as GDNF can stimulate functional 
regeneration of sensory axons in adult rat spinal cord.*” 
Interestingly, one group has made use of the similarities between 
enteric glial cells and OEG cells, and shown that transplanted 
enteric glial cells can also promote regeneration of axons in the 
spinal cord of adult rats.**® Clinical trials are underway to test the 
abilities of OEG cells in spinal cord injury patients. Finally, a 
significant impediment to recovery from spinal cord injury is the 
formation of a glial/astrocyte scar at the site of injury, which can 
prevent growth of axons no matter what the source of the cells. 
Menet et ai. have shown, using a mutant mouse model, that much of 
the scar can be prevented by inhibition of glial fibrillary acidic 
protein and vimentin.**® In mutant mice that lacked these genes, 
there was increased sprouting of axons and functional recovery after 
spinal cord injury. Thus, endogenous neural cell growth and 
reconnection might suffice for repair of damage if inhibitory 
mechanisms can be removed from neural systems. 
hNT CELLS 
Embryonal carcinoma (EC) cells can be derived from 
teratocarcinomas of adult patients, and show multipotent 
differentiation abilities in culture. From one such isolation, a 
"tamed" (non-tumorigenic) line of cells with neuronal generating 
capacity has been developed, termed hNT (NT-2) cells. Because of 
their capacity to generate neuronal cells, these cells have been 
studied for possible application in regeneration of neuronal tissues. 
The hNT neurons show the ability to generate dopaminergic 
neurons,*^® and have shown some benefit of transplantation in animal 
models of amyotrophic lateral sclerosis (ALS, Lou Gehrig’s 
disease).*^* Early clinical trials using hNT neurons transplanted into 
stroke patients have shown initial positive results.*^ 
MUSCLE STEM CELLS 
PRE -PUBLICATION VERSION 
