Quantitation of WBC NE activities
To quantify the activity of NE in the WBC pellets, kinetic enzymatic assays were applied to the WBC lysate samples as previously described [For the data analyses, only patients with baseline WBC extract NE values were evaluated to enable a determination of the change in NE activity from baseline. There were patients with missing WBC extract NE values at baseline (and at subsequent time points) due to misapplication of the WBC pellet procedure by the clinical sites leading to samples becoming compromised and unable to be assayed.