Interesting research reported via ScienceDaily: "Unexpected results from a [recent study] could completely alter scientists' ideas about Alzheimer's disease - pointing to the liver instead of the brain as the source of the 'amyloid' that deposits as brain plaques associated with this devastating condition. The findings could offer a relatively simple approach for Alzheimer's prevention and treatment. ... The product of [the mouse gene corresponding to a gene known to predispose humans carrying particular variations of it to develop early-onset Alzheimer's disease], called Presenilin2, is [involved] in the generation of pathogenic beta amyloid. Unexpectedly, heritable expression of Presenilin2 was found in the liver but not in the brain. Higher expression of Presenilin2 in the liver correlated with greater accumulation of beta amyloid in the brain and development of Alzheimer's-like pathology. ... This finding suggested that significant concentrations of beta amyloid might originate in the liver, circulate in the blood, and enter the brain. If true, blocking production of beta amyloid in the liver should protect the brain. ... mice were administered imatinib [which] has poor penetration of the blood-brain barrier in both mice and humans. ... Because it doesn't penetrate the blood-brain barrier, we were able to focus on the production of amyloid outside of the brain and how that production might contribute to amyloid that accumulates in the brain, where it is associated with disease. ... the drug dramatically reduced beta amyloid not only in the blood, but also in the brain where the drug cannot penetrate. Thus, an appreciable portion of brain amyloid must originate outside of the brain, and imatinib represents a candidate for preventing and treating Alzheimer's."

Link: http://www.sciencedaily.com/releases/2011/03/110303134435.htm