title: Shift from fibrillar to nonfibrillar Abeta deposits in the neocortex of subjects with Alzheimer disease.
abstract: A morphometric study of amyloid-beta-positive plaques in the neocortex of eight non-demented people from 68 to 82 years of age and 17 subjects with late-stage Alzheimer disease (GDS stage 7/FAST stages 7a-f) from 73 to 93 years of age shows a shift from prevalence of fibrillar plaques to prevalence of nonfibrillar plaques. In the aged, non-demented subjects, about 4/mm^2 plaques are detectable in the neocortex, and the majority are fibrillar plaques. Specifically, 64% found to be classical fibrillar and Thioflavin-S-positive bright primitive plaques. A lower percentage of pale primitive plaques (35%) relatively small proportion of plaques that are poor in thioflavin S-positive fibrils. The numerical density of plaques in the severe stage of AD increases to about 41/mm^2. Severely demented subjects appear to maintain an active process of fibrillar plaque formation. This is reflected in the presence of 3% bright primitive plaques. Severely demented subjects also manifest plaque degradation, reflected in the presence of 22% and 48% percentages of classical fibrillar plaques in non-demented subjects and in the end stage of disease suggest that once activated, the process of fibrillar plaque formation persists at a somewhat stable rate during the whole course of brain amyloidosis.
authors.affiliation: New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Wegiel
authors.forename: Maciej
authors.initials: M
authors.lastname: Bobinski
authors.forename: Michal
authors.initials: M
authors.lastname: Tarnawski
authors.forename: Jerzy
authors.initials: J
authors.lastname: Dziewiatkowski
authors.forename: Eirene
authors.initials: E
authors.lastname: Popovitch
authors.forename: Margaret
authors.initials: M
authors.lastname: Bobinski
authors.forename: Boleslaw
authors.initials: B
authors.lastname: Lach
authors.forename: Barry
authors.initials: B
authors.lastname: Reisberg
authors.forename: Douglas C.
authors.initials: DC
authors.lastname: Miller
authors.forename: Susan
authors.initials: S
authors.lastname: De Santi
authors.forename: Mony J.
authors.initials: MJ
authors.lastname: De Leon