Prana Biotechnology Limited (PBT) said a recent independent study conducted by Massachusetts General Hospital had demonstrated that the company’s metal-protein attenuating compounds could halt Alzheimer's pathology. The company said the study showed that the administration of the anesthetic gas isoflurane could spur the production of amyloid-beta protein, which causes plaques in the brains of Alzheimer's patients. A group of mice in the study treated with clioquinol, also known as PBT1 and the predecessor of Prana’s compound PBT2, prior to receiving the isoflurance, had significant lower levels of the enzyme that leads to amyloid-beta production.