Prism 5

Data are expressed as means±standard error of means, and
significant p-value (2-sided) was set at p<0.05. For vasoreactivity,
overall response to acetylcholine was assessed by computing effective dose of
acetylcholine producing 50% dilator response (LogM EC50). This was calculated
using nonlinear regression using variable slope (4 parameters) and least squares
(ordinary fit), as described previously (Migrino
et al., 2011). Control (baseline) response was compared to the
post-treatment response in the same arteriole for each acetylcholine and
papaverine dose using paired Student's t-test. Dilator responses to
acetylcholine and papaverine were compared between different treatments (e.g.
Aβ versus Aβ+PEGSOD) using unpaired Student's t-test. For DCF and
nitrotyrosine assays, arteriole response to Aβ was compared separately to
vehicle and Aβ+PEGSOD using paired Student's t-test of raw DCF and
nitrotyrosine data. Prior to analysis, the DCF and nitrotyrosine data (in
arbitrary units) were transformed (reciprocal) and the resulting paired
Student's t-test passed test of normality of distribution of data. The
representation of the data, however, was expressed as values relative to vehicle
control (Figure 2). Statistical analyses
were performed using GraphPad Prism 5.0 (San Diego CA) and SigmaStat 3.5
(Richmond CA).

Results are expressed as mean ± standard error of the mean (SEM)
and were analyzed using the t-test, chi-square test or one-way analysis of
variance on ranks (Wilcoxon signed rank test) using Prism5 or SigmaStat3.5
software. All p-values are two-sided, and p < 0.05 was considered
statistically significant.