Objective The aim of this research was to provide a basis for the development of preventive and curative measures against the toxoplasma infection by investigating the current infection of toxoplasma and its epidemic characteristics among the population of the Cangzhou city.Methods Antibodies IgG and IgM against toxoplasma in the sera were determined by ELISA during Jan.-May,2007.Results Six hundred and thirty-servn subjects were screened.The positive rate was 6.3% for total antibodies,5.2% for IgG and 1.1% for IgM.The infection rate was higher in the population aged 19-24 years and 49-60 years.The positive rate was higher in farmers living in countryside,those who were poor educated and who had bad habit of cooking food without separating knives and chopping boards to handle raw food and ready-to-eat food and washing their hands after cutting raw meat(P

BACKGROUND:Research on ethyl pyruvate detection methods is reported rarely, and moreover, literature about reversed-phase high-performance liquid chromatography (RP-HPLC) for detection of ethyl pyruvate is less.
OBJECTIVE:To establish an RP-HPLC method for determination of ethyl pyruvate in ethyl pyruvate-chitosan nanoparticles.
METHODS: The chromatographic analysis was performed on a ZORBAX Eclipse XDB-C18 column (4.6 mm× 150 mm, 5μm) at 25℃, with the mixture of acetonitrile and water (40:60, V/V) as the mobile phase at the flow rate of 1 mL/min. The determination wavelength wasset at 210 nm and the injection volume was 20 μL.
RESULTS AND CONCLUSION: The peak of ethyl pyruvate and the peaks of auxiliary materials and solvent were separated wel. The linear rang of ethyl pyruvate was 1-100 mg/L (r=0.999 6). The relative standard deviation of both the intra-and inter-day precision was less than 3% for low-, moderate-, and high-concentration ethyl pyruvate. The relative standard deviation of reproducibility test and stability test was 1.25% and 1.3%, respectively. Sample average recovery rates were (91.5±1.0)%, (3.5±0.2)%, (94.4±0.4)%, respectively. Encapsulation efficiency of samples were (87.2±0.22)%, (90.5±0.15)%, (91.1±0.17)%, respectively. The relative standard deviation of different sample content were 0.9%, 0.5%, 0.3%, respectively. The RP-HPLC method for determination of ethyl pyruvate is sensitive, accurate and highly specific with wide linear range and high sample average recovery.

Objective To construct five shRNA-expression plasmids and to investigate the expression of Smad2 in TGF-?/ Smads signal transduction treated with shRNA-expression plasmid.Methods Five shRNA-Smad2 DNA sequences from mRNA sequence of mouse Smad2 gene were designed and synthesized.DNA oligonucleotides encoding an appropriate shRNA were inserted to shRNA expression vector respectively.Five shRNA-Smad2 expression plasmids were obtained and then transfected into NIH/3T3 cells.The suppressed expression of Smad2 was assessed by RT-PCR and Western-blotting.Results The shRNA-expression plasmid numbered 2.4 could markedly reduce the expression of Smad2.The suppression effect of the RNAi-pool composed of four different plasmids was more obvious than that of any single.Conclusion The shRNA-expression plasmids were successfully constructed,which could specifically and effectively suppress the expression of Smad2.The method of using a mixture of RNAi plasmids to improve the RNAi efficiency was established.