Ammonium hydroxide treatment of A beta produces an aggregate free solution suitable for biophysical and cell culture characterization

Alzheimer's disease is the leading cause of dementia in the elderly. Pathologically it is characterized by the presence of amyloid plaques and neuronal loss within the brain tissue of affected individuals. It is now widely hypothesised that fibrillar structures represent an inert structure. Biophysical and toxicity assays attempting to characterize the formation of both the fibrillar and the intermediate oligomeric structures of Aβ typically involves preparing samples which are largely monomeric; the most common method by which this is achieved is to use the fluorinated organic solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Recent evidence has suggested that this method is not 100% effective in producing an aggregate free solution. We show, using dynamic light scattering, size exclusion chromatography and small angle X-ray scattering that this is indeed the case, with HFIP pretreated Aβ peptide solutions displaying an increased proportion of oligomeric and aggregated material and an increased propensity to aggregate. Furthermore we show that an alternative technique, involving treatment with strong alkali results in a much more homogenous solution that is largely monomeric. These techniques for solubilising and controlling the oligomeric state of Aβ are valuable starting points for future biophysical and toxicity assays

Attitudes Toward the Insanity Defense: Examination of the Factor Structure of Insanity Defense Attitude-Revised (IDA-R) Scale in Ghana

Decades of research have revealed the potential of individuals to be partial toward defendants pleading insanity at the time of offense. This study examines the internal structure of the Insanity Defense Attitude-Revised (IDA-R) scale as well as predictors of insanity defense attitude in a Ghanaian sample (N = 253). Using principal component analysis, we identified three distinct latent factors, two (i.e., strict liability, unprofessional behavior and safety concerns) of which corroborate the findings of previous studies, and a unique factor- expression of sympathy. Participants who were highly involved in religious activities were more likely to be sympathetic. Views regarding the causes and treatability of mental illness did not significantly predict insanity defense attitudes.</p