title: Down patients: extracellular preamyloid deposits precede neuritic degeneration and senile plaques.
abstract: Using anti-SP28 (a polyclonal antibody to a 28 residue synthetic peptide homologous to the NH2-terminal region of the Alzheimer amyloid beta-protein) to investigate the cerebral cortex of 6 Down patients aged 6-55 y, we found that, besides senile plaques and congophilic vessels, extracellular deposits unrelated to degenerating neurites, tangle-bearing neurons or congophilic vessels were labelled. These deposits were similar to the extracellular deposits previously observed in the cerebral cortex of Alzheimer patients and non-demented individuals. The material accumulated in the deposits did not react with Congo red, thioflavine S or, on some occasions, silver salts and therefore might have been constituted by beta-protein precursors lacking the molecular conformation of amyloid fibrils. Age-related analysis of the cortical lesions in Down patients suggested that such extracellular deposits precede degenerating neurites and evolve into senile plaques.
authors.affiliation: Istituto neurologico Carlo Besta, Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Giaccone
authors.forename: F
authors.initials: F
authors.lastname: Tagliavini
authors.forename: G
authors.initials: G
authors.lastname: Linoli
authors.forename: C
authors.initials: C
authors.lastname: Bouras
authors.forename: L
authors.initials: L
authors.lastname: Frigerio
authors.forename: B
authors.initials: B
authors.lastname: Frangione
authors.forename: O
authors.initials: O
authors.lastname: Bugiani
mesh_terms: D000328:Adult; D000367:Age Factors; D000682:Amyloid / Q000276:immunology / Q000378:metabolism*; D016229:Amyloid beta-Peptides; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology*; D002648:Child; D003599:Cytoskeleton / Q000473:pathology*; D003712:Dendrites / Q000378:metabolism / Q000473:pathology*; D004314:Down Syndrome / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007382:Intermediate Filaments / Q000473:pathology*; D008875:Middle Aged
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides