Ultrafiltrate of blood plasma modulates amyloid-β aggregation.

Several neurodegenerative diseases, including Alzheimer's disease (AD), have etiology connected to abnormal protein self association. Copper-induced striking differences in amyloid-β40 aggregation, distinct from spontaneous self association, prompted us to study whether amyloid-β40 aggregation could be applied to differentiate between platelet poor plasma ultrafiltrates obtained from AD and control samples. We report, based on 20 AD and 18 age-matched controls, a significant difference in the concentration of short fibers induced by ultrafiltrated plasma from AD compared to control samples.

Iron and reactive oxygen species activity in parkinsonian substantia nigra.

Objectives: We sought to determine concentrations of total and labile iron in substantia nigra from patients with Parkinson disease and from controls to assess if oxidative stress is triggered by an increased concentration of iron.

Methods: Total iron concentration in the whole substantia nigra was evaluated in 17 parkinsonian and 29 control samples. Concentrations of labile iron and copper were assessed in 6 parkinsonian and 8 control samples.