Effect of S83143, a praziquantel derivative, and its phosphate salt S85009, sulfate salt S85010 and hydrochloride salt S85021 on different developmental stages of Schistosoma japonicum in mice were ob- served. When infected mice were treated with S83143 suspension at a single oral dose of 400 mg/kg or with 3 different salts of S83143 at a single intramuscular dose of 100 mg' ( S83143 base )/kg, the worm reduction rate was 69~87% in 2 h old schistosomula and 47~96% in 32~33 d old adult worms, respectively, but had no effect on 3 ~14 d schistosomula. The results showed that the susceptibility of different developmental stages of schistosome to S83143 was similar to that of praziquantel.The acute LD50 of ig S83143 suspension was more than 10g/kg, while ED50 was 352?65 mg/kg. With im S85010 solution, the LD50 and ED50 were 176?14 and 66?10 mg/kg respectively. Therefore, the therapeutic index of S83143 was over 28, which was higher than 2.67 of S8S010.

Mice, were each infected with 48-52 different geographic Schisto-soma japonicum cercariae of Zhejiang Hangzhou, Jiangsu Wuxi,Anhui Guchi,Jiangxi Nanchang,Hubei Hanyang , Hunan Yueyang & Yunnan Dali. 32-35 d after infection, the mice were treated orally with praziquantel at a single dose of 400 mg/kg. The worm reduction rates of each geographic S. japonicum were compared with that of Anhui Guchi schistosomes which was known to be more sensitive to praziquantel. The results showed that the worm reduction rate of Yunnan Dali schistosomes was 35.1%, which was much less than 75.4% of Anhui Guchi schistosomes. No apparent difference in susceptibility of other 5 geographic schistosomes to praziquantel was observed as comparing with Anhui Guchi schistosomes.When mice infected with Yunnan or Anhui schistosomes for 5 weeks were treated orally with praziquantel at a single dose of 300 mg/kg. the drug-induced hepatic shift rate of the worms and morphological changes of the worms were more or less similar in both geographic schistosomes within 28 d after medication. It was considered that less effect of praziquanfel on Yunnan Dali schistosomes may be ascribed to less susceptibility of the worms to the drug.

Objective: To explore the epidemic characteristics of injury related deaths in children and adolescents aged 1-24 years old in China from 2010 to 2020, so as to provide a basis for the formulation of policies and measures related to the control of injuries and deaths among children and adolescents. Methods: The data were sourced from the China Death Cause Monitoring Dataset from 2010 to 2020. Annual percentage change (APC) and average annual percentage change (AAPC) of injury deaths in China in this age group during the period 2010 to 2020 were analyzed by Join point regression. Results: From 2010 to 2020, the standardized death rate of injury showed a decreasing trend (AAPC=-6.90%, t =4.58, P <0.01). The standardized death rates of male and rural injuries showed an overall downward trend, with AAPC rates of -8.37% and -7.79%( t =11.87, 10.34, P <0.01). An increasing trend was observed in the 20-24 year-old age group during 2010-2018 (APC=18.11%, t =6.50, P <0.01). The death rate from injuries was higher in males than females, and higher in rural areas compared with urban areas ( χ 2=16 483.64, 3 268.65 , P <0.01). A downward trend was observed in accidental falls and suicide, the overall standardized mortality rate of traffic accidents, accidental poisoning, fire, drowning, homicide and other injuries (AAPC=-10.22%, -6.21%, -7.50%, -7.94%, -9.01% , -10.97%, t =16.23, 7.29, 2.53, 9.32, 7.88, 4.58, P <0.05). Conclusion From 2010 to 2020, the overall injury standardized mortality rate in the 1-24 year-old age group shows a decreasing trend, but it remains at a relatively high level. Prevention efforts should be continuously strengthened, especially for urban areas, and should focus on women and those aged 20-24 years old, as well as accidental falls and suicide prevention.