Medical Procedures
Spinal cord injuries
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Currently there are between 183,000 and 230,000 people in the United States with spinal cord injuries, and it's believed that there are more than 11,000 new cases each year. SCI primarily affects young adults. Fifty-five percent occur in people 16 to 30 years old, with the average age of injury at 32. More than 80 percent of all spinal cord injuries happen to men. Since 1990, motor vehicle crashes account for around 38 percent of the injuries reported. The next largest contributor is acts of violence (primarily gunshot wounds), followed by falls and recreational sporting activities. Interesting trends in the database show the proportions of injuries due to motor vehicle crashes and sporting activities have declined while the proportion of injuries from acts of violence and falls has increased steadily since 1973.
When a person suffers a spinal cord injury, often the nerve fibers running from the brain to the spinal cord that control movement and sensation are severed. As a result, the spinal cord is isolated from the brain and the brain can no longer command the cord. The outcome is paralysis and depending on what part of the cord is injured, paralysis begins at varying points. Another outcome is that there is damage to the brain neuron processes that descend to the cord.
Ira Black, M.D., of Robert Wood Johnson Medical School, describes the nervous system as having a plasticity. The nerve cell function changes with altered experience, which is what allows you to remember certain things or even heal after injury. These changes happen on a very basic level. Dr. Black and colleagues decided to see how flexible the nerve cell, called a neuron, is and how much it could change with experience. He started with very basic, immature nerve cells called stem cells and tried to see if they could be used change into blood cells. When they found that it could, they reasoned, if a nerve cell could turn into a blood cell, then a blood stem cell should be able to turn into a nerve cell.
Researchers placed bone marrow stem cells in a culture. The stem cells started as flat, pancake-shaped cells. Within minutes, Dr. Black said, "These flat cells contracted, they developed small cell bodies, as we call them, they extended processes just like normal neurons to contact other neurons, and for all the world, they looked like neurons." Then they found appropriate neuron specific genes were activated, too. This essentially means that the newly developed cells were, for all intents and purposes, nerve cells. From there, the newly developed cells were injected into the brains of rats. What they found was that the cells were able to survive for long periods of time and there were no negative side effects.
The next step is to try the newly developed cells in animal models with Parkinson's disease and Alzheimer's disease. They are also working to find out the best time to transplant the cells into the brain. While the research still has a long way to go, the ultimate hope is to one day be able to transplant new nerve cells into the damaged area and recover lost function. Since the cells start as bone marrow cells, they can come from the patient and eliminate any risk of rejection. Dr. Black says this could lead to a revolutionary approach in medicine and a way to treat a wide variety of conditions in which cells are injured and dying.
Reprinted with permission. Copyright ©2005TWEAN News Channel of Austin, L.P. d.b.a. News 8 Austin