RESUMO
Objective To evaluate the acute and delayed killing effect of high intensity focused ultrasound (HIFU) on Echinococcus granulosus(E. granulosus)protoscolices in vitro.Methods E. granulosus protoscolices were treated with different dosage of effective power(0,25,50,100,200,250 W)and time(5,10,20,30,40,50,60 s)of HIFU in vitro to obtain the dosage-effect curves.Then the survival pmtoscolices were incubated,and the mortality of each group was counted daily.The protoscolicidal effects were investigated by trypan blue exclusion assay.Results Compared with the untreated group,the Vitality of E.granulosus protoscolices significantly decreased immediately after treated by HIFU of different dosage(F=5201.59 vs 1865.65,P＜0.05),there were the interaction both different dosage and time(F=214.50,P＜0.05).The protoscolices were broken into pieces by HIFU of 250 W×40 s,whereas the growth of the surviving protoscolices after exposed to HIFU was obvious suppressed.Both the acute killing effect and the delayed inhibitory effect showed a dosage-dependant manner.The inhibitory effect increased along with the increased dosage of HIFU(P＜0.05).The inhibitory effect in 50 W×10 s group was stronger than 25 W×20 s group(P＜0.05).The mortality was increased in parallel with the increase of HIFU dosage.Conclusions HIFU show an effective immediately killing effect,as well as a growth-inhibiting effect on the E.granulosus protoscolices in vitro.