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SCI Health Issues
Embryonic Stem Cell Therapy & Spinal Cord Injury Cure
Spinal Cord Injury Stem Cell Sections
Traumatic injury to the spinal cord prevents electrical nerve messages travelling to and from the brain. When injured, the substance coating the nerves breaks down, along with cellular damage to the neurons, and the electrical signals short circuit, stopping the signals from reaching their destination. These messages control most functions of the human body, including touch and sensation, muscle movement, bladder control and sexual function. With the loss of these messages, the body is paralysed below the level of injury.
Just days after the inauguration of President Barack Obama, the FDA decided to clear the way for the world's first study on human embryonic stem cell therapy. Geron Corp, the company behind the research, plans to initiate a clinical trial in patients newly paralysed due to spinal cord injury. Initially, a handful of patients with severe spinal cord injuries will be eligible for injections of specialised nerve cells, designed to enable electrical signals to travel between the brain and the rest of the body. When the cells were administered to rats that had lost control of their hind legs, they regained the ability to walk and run, although with a limp.
As a Phase I trial, the study by Geron will primarily assess the safety of the treatment, which has been under development by Geron Corp. for nearly a decade. Scientists, doctors and patients said they were most eager to see whether low doses of the cells would produce any therapeutic benefit.
Embryonic stem cells are coveted by researchers because they theoretically have the ability to grow into any kind of cell in the body. Even if the experimental therapy in spinal cord therapy doesn't make paralysed patients walk again, it could still substantially improve their quality of life.
To treat spinal cord injuries, scientists first needed to reverse the damage to oligodendrocytes, cells that insulate nerve fibres with myelin so that signals can be transmitted to and from the brain. The hard part was figuring out the complex combination of growth factors and other chemicals that would turn stem cells into oligodendrocyte progenitor cells that could make new myelin.
When this method was tested on rats, seven days after the rat's injury, scientists injected the rats at the site of the injury with the progenitor cells. After four weeks, the rats could walk, run and stand on their hind legs, and their coordination had fully recovered, UC Irvine researchers spent two years studying hundreds of rats to make sure the injections were safe. Pure embryonic stem cells tend to grow into tumours, but the rats showed no such signs for a year after treatment. Blood and urine tests turned up none of the chemicals that would signal a toxic reaction.
Geron plans to start a Phase I multi-center trial that is specifically designed to assess the safety and tolerability of GRNOPC1 in spinal cord injury patients with "complete" American Spinal Injury Association (ASIA) grade A subacute thoracic spinal cord injuries.
The selected patients eligible for the Phase I trial must have documented evidence of functionally complete spinal cord injury with a neurological level of T3 to T10 spinal segments and agree to have GRNOPC1 injected into the lesion sites between seven and 14 days after injury.
If the cells are administered sooner, they could be damaged by inflammation from the injury. If doctors wait too long, there might be too much scar tissue for the cells to find room to grow,
Patients will be given a low-dose anti-rejection drug for 60 days to ensure their bodies don't reject the GRNOPC1 cells, even though research indicates that the cells won't be recognized by the human immune system.
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