Validation of the Social Responsiveness Scale (SRS) to screen for atypical social behaviors in juvenile macaques.

Primates form strong social bonds and depend on social relationships and networks that provide shared resources and protection critical for survival. Social deficits such as those present in autism spectrum disorder (ASD) and other psychiatric disorders hinder the individual's functioning in communities. Given that early diagnosis and intervention can improve outcomes and trajectories of ASD, there is a great need for tools to identify early markers for screening/diagnosis, and for translational animal models to uncover biological mechanisms and develop treatments. One of the most widely used screening tools for ASD in children is the Social Responsiveness Scale (SRS), a quantitative measure used to identify individuals with atypical social behaviors. The SRS has been adapted for use in adult rhesus monkeys (Macaca mulatta)-a species very close to humans in terms of social behavior, brain anatomy/connectivity and development-but has not yet been validated or adapted for a necessary downward extension to younger ages matching those for ASD diagnosis in children. The goal of the present study was to adapt and validate the adult macaque SRS (mSRS) in juvenile macaques with age equivalent to mid-childhood in humans. Expert primate coders modified the mSRS to adapt it to rate atypical social behaviors in juvenile macaques living in complex social groups at the Yerkes National Primate Research Center. Construct and face validity of this juvenile mSRS (jmSRS) was determined based on well-established and operationalized measures of social and non-social behaviors in this species using traditional behavioral observations. We found that the jmSRS identifies variability in social responsiveness of juvenile rhesus monkeys and shows strong construct/predictive validity, as well as sensitivity to detect atypical social behaviors in young male and female macaques across social status. Thus, the jmSRS provides a promising tool for translational research on macaque models of children social disorders.

Evaluation of fluorescence immunoassay for total and unbound serum concentrations of disopyramide.

The accuracy of determining disopyramide concentrations in 80 serum samples by high-performance liquid chromatography (HPLC) and fluorescence immunoassay (FIA) on 2 consecutive days was similar. The precision of both methods was excellent. The interday precision of FIA was superior to HPLC at nominal concentrations of 1.5 and 3.0 mg/L, but was similar at 7.0 mg/L. Following equilibrium dialysis of 40 serum samples, the unbound concentration of disopyramide determined by a modified FIA method under-estimated by 16% the unbound concentration determined by a reference method. The discrepancy may be avoided by preparing standards in the appropriate buffer. Fluorescence of disopyramide optical isomers at similar concentrations were identical. It is concluded that FIA for determining plasma concentrations of disopyramide is accurate and precise, and may be modified to accurately determine unbound concentrations following separation of plasma water and protein.