Fig. 2

Neuropathologic findings of the cerebral biopsy. Severe amyloid angiopathy appeared as thickening of the wall of parenchymal arterioles (A Haematoxylin &Eosin) where amorphous material was present, exhibiting yellow/green fluorescence after thioflavine S treatment (B) and immunopositivity for Aβ (C 4G8 mouse monoclonal, 1:2000, after 80% formic acid for 20 min). The antibody specific for Aβ40 (mouse monoclonal, Covance, 1:1000, after 80% formic acid for 20 min) strongly decorated the amyloid-laden vessels (D), including capillaries (E). Aβ deposits were also abundant in the neuropil and these were intensely immunolabeled by anti-Aβ42 (F). Tau pathology was present, appearing as neurofibrillary tangles and neuropil threads (G) and clusters of dilated neurites (H) immunopositive for anti-phosphorylated tau antibody AT8 (mouse monoclonal, Biosource, 1:300). α-synuclein inclusions were absent (I). Immunolabeling was visualized by the Envision Plus/Horseradish Peroxidase System (DakoCytomation) using 3–3’-diaminobenzidine (brown reaction product) as chromogen. Bar in A = 35 µm (A, B and H are the same magnification); bar in C = 75 µm (C, E, F, G and I are the same magnification); bar in D = 350 µm