Dear All:  I recently sent around discussions of ways to measure/estimate drug concentrations both in living animals (aptamer-based probes, Kevin Plaxco’s group) and with sufficient spatial resolution to permit construction of 2d/3d drug concentration maps (MALDI-MSI, David Perlin’s group). In the context of our efforts to learn to better apply PK-PD (e.g., the 14-15 June 2017 NIAID PK-PD workshop),