U.S. Sen. Sam Brownback, a leading opponent of using embryonic stem cells, last week chaired a hearing that investigated the use of adult stem cells.

The hearing of the Science, Technology and Space Subcommittee of the Senate Commerce, Science and Transportation Committee focused on using adult stem cells to treat symptoms in patients with Parkinson’s and paralysis.

Research with adult stem cells has made progress in areas such as heart tissue regeneration, spinal-cord injury, tissue regrowth, restoring blood flow, regrowing corneas, curing sickle-cell anemia and treating multiple sclerosis and lupus, said Brownback, R-Kan.

Embryonic stem cells, many researchers say, have greater potential to regenerate tissue. In the process of obtaining stem cells from an embryo, the embryo is destroyed. Often the embryos are left over from in vitro fertilization, and would have been discarded anyway.