Fig. 1

ProNGF serum levels after thyroidectomy and half-life. a Change in serum proNGF following total thyroidectomy. Pre- and post- thyroidectomy serum samples were available for 11 cases where pre-operative serum proNGF was detectable. No significant difference was detected between pre- and post- thyroidectomy levels of proNGF. b ProNGF in vitro half-life. Aliquots of serum negative for proNGF was spiked with 20 ng/mL recombinant proNGF dissolved in Assay Diluent A (Biosensis, Australia) in a 1:1 ratio, then incubated at 37 °C for increments of 24 h, then assayed at 1:20 dilution with Heterophilic Blocking Antibody (BL-003-1000). An exponential decay curve was fitted, giving an estimated in-vitro half-life in serum of 1.5 h. Similar results were obtained using phosphate-buffered-saline as diluent