PTK787/ZK222588 treatment of B.schlosseri systems. DMSO (A, B, C) and PTK787/ZK222588 (E, F, G) injection in single genotype systems. Three hours after injection (t0), part of the ampullae and the marginal have been surgically removed (B, F; dotted line) and the grade of regrowth monitored for 72 hours (t0+72h, C, G). Scale bar 1mm.