Study on construction of citrostatin and its bioactivity / 中国生化药物杂志

Purpose To construct a recombined antitumor peptide and to analyze its bioactivity. Methods Constructing a recombined gene and inserting the pGEX-4T-3 vector. The recombined protein was expressed in E. coli BL21 and purified with Amylose Resin. Then, citrostatin was subjected to the following tests separately: inhibition of endothelial cell proliferation, MTT test of cytotoxicity and inhibition of endothelial cell tube formation on ECMatrix. Results Citrostatin significantly inhibited the proliferation of human endothelial cell ECV304(IC_(50) = 2.28 μmol/L) .It also significantly inhibited the proliferation of human tumor cell 1990 and NCI-H64O(IC_(50) = 9.24,2.74 μmol/L) ,and the inhibitory effect became more marked with the increase of citrostatin concentration. The inhibitory effects of citrostatin on endothelial cell tube formation was also confirmed . Conclusion An antitumor peptide, citrostatin, has been successfully constructed and purified, which showed anti-angiogenesis effect and direct cytotoxic effect on tumor cells.

Study on Animal Models of Decompression Sickness / 航天医学与医学工程

Objective To study the profiles of decompression sickness(DCS) in various kinds of animals and to find out the target organ of decompression sickness by providing a basic experimental method for establishing animal models.Method Eleven kinds of animals were exposed to different pressures for different times at different compression/decompression rates.They were monitored at the precordial regions with Doppler flow meter for bubble sounds after decompression to normal pressure,to obtain a record about the developing course of the DCS.Pathological examinations of the bulbar conjunctiva were also made. Result Bubble sound of grade IV were recorded at the precordial regions after decompression.Among them,75%~100% incurred DCS with a diverse extent. Animals developed DCS showed vascular spasm,dysfunction and endothelial tumefaction.Conclusion Each of the 11 kinds of animals can serve as a model of DCS and the processes of development of DCS in various animals are similar.Blood vessels are the target organs of decompression sickness.

Immunogenicity of a multiple epitope antigen gene of hepatitis C virus in mice and rabbits / 细胞与分子免疫学杂志

Aim To explore the possibility of the multiple epitope DNA vaccines of hepatitis C virus (HCV). Methods A synthetic multiple epitope antigen gene PCX of HCV was cloned into vector pREP9(RSV promoter) and pcDNA3 (CMV promoter) to construct eukaryotic expression vectors pREP9/PCX and pcDNA3/PCX, then they were used to immunize mice and rabbits, the titer of specific humoral and cellular responses were detected and their safety were observed. Results In mice, specific anti-GZ-PCX antibody(IgG) was lower than 1∶ 1 000 and did not persist well. In rabbits, the highest titer of anti-GZ-PCX IgG reached at 1∶ 3 200 and remained for about one month. Delayed type hypersensitivity reactions (DTH)and proliferation response of peripheral lymphocytes were induced by GZ-PCX antigen. Body weights of immunized mice were normal and no obvious toxic reaction was observed. Conclusion The multiple epitope antigen gene of HCV could induce specific immune responses without obvious toxicity and it might be able to serve as an effective HCV vaccine candidate.