Test-retest reliability of the N2 event-related potential in school-aged children with autism spectrum disorder (ASD).

OBJECTIVE: The N2 ERP component is used as a biomeasure of executive function in children with autism spectrum disorder (ASD). The aim of the current study was to evaluate the test-retest reliability of N2 amplitude in this population. METHODS: ERPs were recorded from 7 to 11-year-old children with ASD during Flanker (n = 21) and Go/Nogo tasks (n = 14) administered at two time points separated by approximately three months. Reliability of the N2 component was examined using intraclass correlation coefficients (ICCs). RESULTS: Reliability for mean N2 amplitude obtained during the Flanker task was moderate (congruent: ICC = 0.542, 95% CI [0.173, 0.782]; incongruent: ICC = 0.629, 95% CI [0.276, 0.831]). Similarly, reliability for the Go/Nogo task ranged from moderate to good ('go': ICC = 0.817, 95% CI [0.535, 0.937]; 'nogo': ICC = 0.578, 95% CI [0.075, 0.843]). CONCLUSIONS: These findings support the use of N2 amplitude as a biomeasure of executive function in school-aged children with ASD. SIGNIFICANCE: This research addresses a critical gap in clinical neurophysiology, as an understanding of the stability and reliability of the N2 component is needed in order to differentiate variance explained by repeated measurement versus targeted treatments and interventions.

Protein Mimetic and Anticancer Properties of Monocyte-Targeting Peptide Amphiphile Micelles.

Monocyte chemoattractant protein-1 (MCP-1) stimulates the migration of monocytes to inflammatory sites, leading to the progression of many diseases. Recently, we described a monocyte-targeting peptide amphiphile micelle (MCP-1 PAM) incorporated with the chemokine receptor CCR2 binding motif of MCP-1, which has a high affinity for monocytes in atherosclerotic plaques. We further report here the biomimetic components of MCP-1 PAMs and the influence of the nanoparticle upon binding to monocytes. We report that MCP-1 PAMs have enhanced secondary structure compared to the MCP-1 peptide. As a result, MCP-1 PAMs displayed improved binding and chemoattractant properties to monocytes, which upregulated the inflammatory signaling pathways responsible for monocyte migration. Interestingly, when MCP-1 PAMs were incubated in the presence of prostate cancer cells in vitro, the particle displayed anticancer efficacy by reducing CCR2 expression. Given that monocytes play an important role in tumor cell migration and invasion, our results demonstrate that PAMs can improve the native biofunctional properties of the peptide and may be used as an effective inhibitor to prevent chemokine-receptor interactions that promote disease progression.