Scientists for alternatives to embryonic stem cells
Scientists told a Senate panel on Thursday that alternatives to human embryonic stem cells, including adult stem cell treatment and umbilical cord blood transplants, have had proven success in helping people with crippling and ordinarily fatal diseases.
"There is abundant evidence that adult stem cells can be used as a therapy and are readily available in people," Dr. Jean Peduzzi-Nelson of the University of Alabama at Birmingham told the Senate Commerce science subcommittee. "The conclusion from the preclinical studies is that adult stem cells work just as well, if not better, than embryonic stem cells and are probably safer." The hearing was lead by subcommittee chairman Sen. Sam Brownback, who has questioned the ethical propriety and the necessity of embryonic stem cell research.
President George W Bush also opposes using human embryonic stem cells in medical research for a wide range of neurological and genetic diseases because it involves the death of an embryo, and the Bush administration has put in place strict guidelines controlling the use of federal dollars for embryonic stem cell research. Brownback trumpeted the "amazing results" from alternative methods, inviting to the witness stand 17-year-old Keone Penn, who five years ago became one of the first to be successfully treated for sickle cell anemia with unrelated umbilical cord blood stem cells.
Penn was treated at the National Cord Blood Program at the New York Blood
Center, whose director, Dr. Pablo Rubinstein, said cord blood banks have provided transplants for more than 3,500 patients worldwide, and 1,370 at his center.
He said blood left behind in the placenta and umbilical cord after birth and usually discarded has resulted in less immune reactions, greater availability in less time and less risk of virus infection.
Brownback promised to push for federal funds for a national cord blood bank system.
Dr. David Hess, head of the neurology department at the Medical College of Georgia, cited the advantages of obtaining adult stem cells from bone marrow, saying they are easily isolated, will not be rejected by the patient from which they are taken and avoid the ethical concerns of embryonic stem cells.
"The field is moving fast. Bone marrow derived stem cells are already being tested in small numbers of patients with heart attacks," he said.
Proponents of embryonic stem cells say they have greater potential for regenerative medicine because they are less developed than adult cells and thus can more easily be cultured into new tissue that can be used to replace or repair diseased organs. Peduzzi-Nelson, however, cited studies that adult stem cells from the brain, the upper nose, the cornea and other parts of the eye, teeth and skin are capable of forming neurons.
One witness, Dr. John McDonald of the Washington University School of Medicine neurology department, stressed that no research door, including that leading to embryonic stem cell research, should be closed.
Because of their less formed state, it's "much more feasible to try to encourage embryonic stem cells to develop into whichever type of cell is needed," he said. "It's entirely too early to rule out any one of these areas of research in favor of any other."
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