Comparison of the D-N values in brain frontal cortex from cases of VPSPr, sCJD MM1, sCJD MM2, sCJD VV2, vCJD, two GSS cases and non-CJD. (a) The D-N values for VPSPr patients are the means (+/- S.D.) of five patients, whereas the values for non-CJD are from ten patients, five being cases of sudden death, three Alzheimer’s disease, one cerebral infarction and one motor neurone disease/frontal lobe dementia. Also shown for comparison, are D-N values for individual patients with vCJD (MM2B), sCJD subtypes MM1 and MM2, and VV2, and two cases of GSS with the P102L mutation of PRNP, one GSS (~8 kDa) and the other GSS (type 1). For the latter results from individual patients, the D-N values are the means (+/- S.D.) of triplicate analyses of single samples. (b) The D-N values (log10 scale) are shown for the same brain frontal cortex samples as in (a), but additionally D-N values obtained after treating the homogenates with no PK (red bars) are compared with the values obtained after 2.5 or 50 μg/ml PK (green and blue bars), respectively.