title: In vivo assessment of amyloid-β deposition in nondemented very elderly subjects.
abstract: OBJECTIVE
  This study examined amyloid-β (Aβ) deposition in 190 nondemented subjects aged ≥82 years to determine the proportion of Aβ-positive scans and associations with cognition, apolipoprotein E (APOE) status, brain volume, and Ginkgo biloba (Gb) treatment.
  
  
  METHODS
  Subjects who agreed to participate had a brain magnetic resonance imaging and positron emission tomography scan with (11) C-labeled Pittsburgh compound B (PiB) following completion of a Gb treatment clinical trial. The youngest subject in this imaging study was 82 years, and the mean age of the subjects was 85.5 years at the time of the scans; 152 (80%) were cognitively normal, and 38 (20%) were diagnosed with mild cognitive impairment (MCI) at the time of the PiB study.
  
  
  RESULTS
  A high proportion of the cognitively normal subjects (51%) and MCI subjects (68%) were PiB-positive. The APOE*4 allele was more prevalent in PiB-positive than in PiB-negative subjects (30% vs 6%). Measures of memory, language, and attentional functions were worse in PiB-positive than in PiB-negative subjects, when both normal and MCI cases were analyzed together; however, no significant associations were observed within either normal or MCI subject groups alone. There was no relationship between Gb treatment and Aβ deposition as determined by PiB.
  
  
  CONCLUSIONS
  The data revealed a 55% prevalence of PiB positivity in nondemented subjects age >80 years and 85% PiB positivity in the APOE*4 nondemented elderly subjects. The findings also showed that long-term exposure to Gb did not affect the prevalence of cerebral Aβ deposition.
authors.affiliation: Department of Radiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA. mathisca@upmc.edu
authors.forename: Chester A
authors.initials: CA
authors.lastname: Mathis
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Kuller
authors.forename: William E
authors.initials: WE
authors.lastname: Klunk
authors.forename: Beth E
authors.initials: BE
authors.lastname: Snitz
authors.forename: Julie C
authors.initials: JC
authors.lastname: Price
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Weissfeld
authors.forename: Bedda L
authors.initials: BL
authors.lastname: Rosario
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Lopresti
authors.forename: Judith A
authors.initials: JA
authors.lastname: Saxton
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Aizenstein
authors.forename: Eric M
authors.initials: EM
authors.lastname: McDade
authors.forename: M Ilyas
authors.initials: MI
authors.lastname: Kamboh
authors.forename: Steven T
authors.initials: ST
authors.lastname: DeKosky
authors.forename: Oscar L
authors.initials: OL
authors.lastname: Lopez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D015995:Prevalence; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D013844:Thiazoles