Advancing Evidence Generation for Circulating Tumor DNA: Lessons Learned from A Multi-Assay Study of Baseline Circulating Tumor DNA Levels across Cancer Types and Stages.

Circulating tumor DNA (ctDNA) holds promise as a biomarker for predicting clinical responses to therapy in solid tumors, and multiple ctDNA assays are in development. However, the heterogeneity in ctDNA levels prior to treatment (baseline) across different cancer types and stages and across ctDNA assays has not been widely studied. Friends of Cancer Research formed a collaboration across multiple commercial ctDNA assay developers to assess baseline ctDNA levels across five cancer types in early- and late-stage disease.

Stimulation of three distinct guanylate cyclases induces mucosal surface alkalinisation in rat small intestine in vitro.

The absorptive surface of the small intestine is isolated from bulk pH changes in the luminal contents by a zone of maintained low pH, the acid microclimate. The present study set out to compare the effects of stimulation of each of the three guanylate cyclases (GCs) expressed in the intestinal mucosa on the pH microclimate of rat jejunum in vitro. The tissue was exposed to specific ligands for each of the GCs and mucosal surface pH determinations were made by a miniaturised glass pH electrode.

Inhibition of neuronal high voltage-activated calcium channels by insect peptides: a comparison with the actions of omega-conotoxin GVIA.

The whole cell variant of the patch clamp technique was used to investigate the actions of two novel insect peptides on high voltage-activated Ca2+ currents in cultured dorsal root ganglion (DRG) neurones. The insect peptides (PMP-D2 and PMP-C) were isolated originally from insect brains and fat bodies, and have been found to have similar three-dimensional structures to the N-type Ca2+ channel inhibitor omega-conotoxin GVIA (omega-CgTx GVIA). High voltage-activated Ca2+ currents were activated from a holding potential of -90 mV by depolarizing step commands to 0 mV.