Schistosoma mansoni: activity responses in vitro to praziquantel. 
The effects of praziquantel, a novel antischistosomal compound, on the activity of adult Schistosoma mansoni (Liverpool strain) in vitro were investigated.  Worm activity was modified at all concentrations of praziquantel.  High concentrations (above 0.5 microgram/ml) produced rapid paralysis, whilst low concentrations of praziquantel stimulated worm activity.  It is concluded that such activity modification could lead to worm displacement in vivo.