The chemical remained only in brains that had deposits
A new experimental test was able to indicate the presence of amyloid deposits in the brain, a sign of the existence of Alzheimer's disease. If the human test results as well as the animal tests, it may allow people with Alzheimer's disease to be diagnosed at an early stage of the disease.
The chemical substance, PIB, used by the researchers, led by Dr. Brian Bakskai from the Massachusetts General Hospital, was able to cross the blood-brain barrier (BBB) and bind to the amyloid deposits in the brains of Alzheimer's diseased mice. According to the researchers, the PIB quickly disappeared from the brains of non-Alzheimer's mice.
The next step, which is already being implemented in Pittsburgh and Uppsala in Sweden, is to test the operation of the PIB in humans. Today it is sometimes possible to diagnose Alzheimer's disease based on the symptoms of the disease, but a definite diagnosis is only possible after the death of the patient. According to William Clank of the University of Pittsburgh, a member of the research team, diagnosing the disease in its early stages is of great importance, because it will allow treatment to begin before much damage is done to the patient. "All the evidence suggests that Alzheimer's disease begins to develop ten years or more before symptoms appear," Klank said.
In the study, published this week in the online edition of the journal "Academy of Sciences" "Proceedings of the National" it was found that PIB binds directly to the amyloid deposits in the brains of mice with Alzheimer's disease. The researchers examined the brain tissue through a hole in the mice's skulls using a powerful photon microscope.
PET scans (tomography of radioactive substances emitting positrons) in the brains of humans do not reach such a high resolution, but according to Klank they can indicate the presence of PIB in the brain, which will indicate the development of Alzheimer's disease.
Dr. Bakskai said that the PIB passed toxicological tests and it was found that it has no side effects. When the substance was injected into the mice's tails, it quickly moved to the brain and bound to sediment. In some cases it was possible to diagnose even three days after being injected. When the brains of the mice were analyzed later, the researchers found that the PIB does not connect to the white matter in the brain - the fibers that connect the cells in the brain (as opposed to the cells themselves, which make up the gray matter).
Dr. Reed Martau, director of the neuroradiology department at the University of South Florida, who also tested ways to diagnose Alzheimer's, welcomed the new findings. According to Martau, "at this stage it is impossible to diagnose the disease with certainty. The new findings may allow us to do this."
