Figure 3. Immunochemical and histopathologic study of humanized transgenic (Tg) mice inoculated with urine from patients with sporadic Creutzfeldt-Jakob disease MM1 (sCJDMM1). A) Immunoblot of brain homogenates (BH) from Tg40 mice inoculated with 100-fold concentrated and dialyzed urine from a sCJDMM1 patient show no proteinase K (PK)-resistant scrapie prion protein (PrPSc). Before immunoblotting, BH samples were treated with sodium phosphotungstate (NaPTA) to concentrate the PrPSc possibly present. BH from a Tg40 mouse inoculated with sCJDMM1 MF is shown as a positive control. A nonspecific band ≈32 kDa was detected in normal and sCJDMM1 urine (arrow). All samples were treated with PK. Histologic (B) and immunohistochemical (C) examinations show neither lesions nor abnormal PrP deposits in the cerebral cortex from urine-inoculated mice. Monoclonal antibody 3F4 was used for all immunostaining. Scale bar in B = 100 μm. Scale bar in C = 50 μm.