US Veteran Brain Injury News
Will stem-cell research help U.S. wounded?
By Peter J. Bryant
More than 12,000 soldiers have been seriously wounded in the Iraq war since it began in 2003. Because of improvements in body armor since the Vietnam War, more soldiers in Iraq can survive bombings and sniper attacks, but this leaves a greater fraction of survivors with gruesome damage to the head, arms and legs caused by blast and shrapnel wounds.
Soldiers who would have died in previous wars are coming home with traumatic brain injury or as amputees. The military does not break down the statistics by type of wound, but according to Col. William Doukas, chairman of the Department of Orthopedics and Rehabilitation at Walter Reed Army Medical Center in Washington, "it is mostly legs." Bullets and shrapnel embedded in the brain are another common type of injury, and the metal is often left in place because removing it can do more damage than the injury itself.
Human limbs, brains and spinal cords are capable of only very limited repair following traumatic injury, so a lifetime of disability faces many of the victims. But many scientists are hopeful that with enough research, we will be able to harness the abilities of embryonic stem cells to form all of the cell types in the body, so that even whole limbs might be regenerated just as they are in a salamander, and neurons could be replaced and reconnected with each other and the organs they control.
Although the prospect of complete regeneration may seem far-fetched, recent discoveries show that stem cells may have beneficial effects even if they can't yet be used to replace lost body parts. After a traumatic injury to the central nervous system, many neurons survive the immediate injury but are then lost as a result of inflammation and loss of the myelin sheath that surrounds the axon and provides it with protection and electrical insulation.
Drs. Hans Keirstead and Oswald Steward, of the University of California at Irvine, have now shown that some of this secondary damage in the spinal cord can be prevented in animal models by treatment with specialized cells derived from human embryonic stem cells. Videos clearly show how rats retain much more mobility following spinal cord injury if they are given stem-cell therapy soon after the injury. The new results suggest that therapy with embryonic stem cells could reduce the amount of damage following traumatic injury to the central nervous system in humans, but the procedure must be more thoroughly tested on animals before it can be safely used on human patients.
Unfortunately, many of our best biologists, who could be working to make such therapies available, are hampered by Bush administration policies that do not allow federal funds to be used to generate new embryonic stem-cell lines or to work on any lines that have been generated since President Bush established the restrictions, based, as we now know, on his religious beliefs, in August 2001. Some scientists are finding ways to continue their embryonic stem-cell work with funding from private companies, while others plan to take advantage of funds freed up by the states, especially California, to compensate for the lack of federal funds.
Other nations with more liberal stem-cell policies are forging ahead and making the discoveries we need. Last month that was clearly happening: Scientists in Korea announced that they had solved the crucial problem of replacing the genes of stem cells with those of a potential patient, so the stem-cell products will not be rejected by the patient's immune system. Scientists all over the world had been eagerly anticipating that discovery, which removes a major scientific roadblock to cell-based therapy.
The United States has the most powerful federally funded health-research program in the world. As Bush indicated (as in announcing his decision to restrict federal support for research on embryonic stem cells), "Federal dollars help attract the best and brightest scientists. They ensure new discoveries are widely shared at the largest number of research facilities and that the research is directed toward the greatest public good. ... The United States has a long and proud record of leading the world toward advances in science and medicine that improve human life. And the United States has a long and proud record of upholding the highest standards of ethics as we expand the limits of science and knowledge."
Clearly, without the federal funding restrictions, the U.S. scientific community could be forging ahead to develop cellular therapies using embryonic stem cells. In anticipating that stem-cell research could lead to a society that creates human beings as a convenient source of spare body parts, Bush said, "I worry about a culture that devalues life." Many of us see a painful irony in that statement coming from a president who sent those 12,000 soldiers and many others to the battlefield in the first place.
In devoting their careers to stem-cell research and to developing therapies without the help of federal funds, scientists are not devaluing life but are recognizing the value of existing human lives and the potential of embryonic stem cells to transform the way that we treat not only battlefield injuries, but a host of other medical problems and genetic diseases as well. Unfortunately, unless the administration comes to its senses, those treatments may never be available to the maimed veterans in VA hospitals.
Peter Bryant is a professor of developmental and cell biology at UC Irvine (pjbryant@uci.edu).
