Pharmacokinetics of praziquantel injection in healthy buffaloes / 中国血吸虫病防治杂志

Objective To investigate the pharmacokinetics and relative bioavailability of praziquantel injection in buffaloes in contrast to praziquantel tablet. Methods A single oral administration of praziquantel tablet at a dose of 20 mg/kg or intramus-cular administration of praziquantel injection at a dose of 10 mg/kg was performed in six healthy adult buffalos according to a two-period crossover design. The praziquantel concentration in plasma was determined by a high performance liquid chromatography (HPLC)method. The pharmacokinetic parameters were calculated by non-compartmental analysis. Results The main pharma-cokinetic parameters of praziquantel tablet were as follows:Tmax=(0.60±0.29)h,Cmax=(0.57±0.37)μg/ml,T1/2β=(0.70±0.42) h,AUC=(0.80±0.70)(μg/ml)·h. The main pharmacokinetic parameters of praziquantel injection were as follows:Tmax=(0.65± 0.49)h,Cmax=(3.82 ± 1.17)μg/ml,T1/2β=(1.00 ± 0.73)h,AUC=(1.61 ± 0.89)(μg/ml)·h. The relative bioavailability of pra-ziquantel injection was 402.5％in contrast to praziquantel tablet. Conclusion The praziquantel injection has pharmacokinetic characteristics of rapid absorption,high bioavailability and extensive distribution,and the clinical recommended dosage of pra-ziquantel injection is 10 mg/kg.

Cloning, expression and protective efficacy evaluation of radiation sensitive protein 23 (RAD23) from Schistosoma japonicum / 生物工程学报

Radiation sensitive protein 23 (RAD23) is a nucleotide excision repair (NER) protein that plays an important role in Ubiquitin-proteasome pathway (UPP). Schistosoma japonicum radiation sensitive protein23 (SjRAD23) cDNA sequences were amplified by PCR and cloned into pET28a (+) vector to construct recombinant expression plasmid pET28a(+)-SjRAD23. The recombinant protein was expressed as both inclusion bodies and the supernatant in Escherichia coli BL21 (DE3) cell. Immunofluorescence observation shows that SjRAD23 was mainly distributed on the tegument surface of the worms. ELISA assay reveals that specific IgG, IgG1 and IgG2a antibodies could be detected in the sera of rSjRAD23 immunized mice. Western blotting analysis shows that the recombinant SjRAD23 could be recognized by serum specific to soluble adult worm antigen of S. japonicum. BALB/c mice vaccinated with rSjRAD23 combined with 206 adjuvant revealed 35.94% worm reduction and 40.59% liver egg reduction when compared with that of the adjuvant control

Distribution characteristics of deposited eggs and pathological changes in viscera of New Zealand white rabbits infected with Schistosoma japonicum at different time / 中国血吸虫病防治杂志

Objective To study the distribution characteristics of deposited eggs and pathological changes in the viscera of animal infected with Schistosoma japonicum at different time. Methods New Zealand white rabbits were infected artificially with quantitative S. japonicum miracidia,then the distribution characteristics and the hatchability of schistosome eggs as well as the pathological changes of the corresponding viscera of the rabbits 42 and 60 d post?infection were observed and compared. Re?sults On the 42nd day post?infection,among all the viscera observed,the percentage of eggs deposited,the number of eggs per gram and the hatchability were the highest in the liver,while on the 60th day post?infection,the tissues and organs with the highest values of the above 3 indexes were the liver,rectum and upper section of the small intestine,respectively. From 42 day to 60 day post?infection,the liver of infected rabbits became swelling,hardening and lost elasticity,the color changed from black to dark grey,and egg nodules gradually appeared in the different sections of the small intestine,and also the mucosal hy?peremia,edema and egg nodules were seen in the colon,cecum and rectum. The lesion levels tended to be correlated with the deposition of eggs. Conclusion The amount and the density as well as the hatching rate of deposited eggs of S. japonicum in the viscera of infected rabbits at different time are different,and the lesion level in the host is correlated with the deposition of eggs.

Cloning,expression and immuno-protection analysis of a gene encoding tro-ponin T of Schistosoma japonicum(SjTnT) / 中国血吸虫病防治杂志

Objective To clone cDNA encoding troponin T of Schistosoma japonicum(SjTnT),and evaluate the protective efficacy induced by recombinant SjTnT in BALB/c mice against S. japonicum challenge infection. Methods The SjTnT gene was amplified from 28-day-schistosome cDNAs by PCR and then subcloned into pET28a(+). The recombinant SjTnT protein (rSjTnT)was expressed in Escherichia coli BL21(DE3)cells. The serum specific to rSjTnT was prepared by immunized BALB/c mice with the recombinant antigen,and the immunogenicity of rSjTnT was detected by Western blotting and ELISA. The immuno-protective efficacy induced by rSjTnT in BALB/c mice was evaluated according to the reduction in worm and egg counts. Results The cDNA encoding SjTnT was successfully cloned and expressed in E. coli. Western blotting showed that rSjTnT had a good immunogenicity. The high level of specific IgG antibodies was detected,and 33.89% worm reduction and 43.94% liver egg reduction were obtained in mice vaccinated with rSjTnT combined with Seppic 206 adjuvant compared with those in the adjuvant control group. Conclusions rSjTnT could induce partial immuno-protection against S. japonicum infec-tion in BALB/c mice. This study provided a basic for understanding the biological function of SjTnT.