Quasispecies investigation on swine hepatitis E viruses / 病毒学报

The objective of current study was to investigate the quasispecies of hepatitis E virus in swine. The partial ORF2 region of HEV envelope gene from four swine HEV strains was amplified by RT-nested polymerase chain reaction (RT-nPCR). After cloning and transformation of PCR products, 20 positive clones of each HEV isolate were subject to sequencing and DNA analysis. The homology among the different clones of each isolates was 96.8%-99.7%, 98.8%-99.7%, 98.8%-99.7% and 100%, respectively, while there was 96.8%-100% sequence identity at the nucleotide level compared with HEV strains isolated in Shanghai (SAAS-JDY5). This study confirmed that there existed quasispecies of HEV in swine.

Extraction and Detect on Immunization of Outer Membrane Protein of Bordetella bronchiseptica / 微生物学通报

P13-OMP (29.1). P13-OMP and OMP68 group challenged with P13 and P11 can be efectivly protected; P13-WCB group challenged with P13 and P11 can not be efectivly protected; the control group were died out. The P13-OMP and OMP68 of Bordetella bronchiseptica has good immunogenicity and protection, so the results of this study lay good theoretical foundation for OMP subunit vaccine.

Studies on chemical constituents of cytotoxic fraction from leaves of Elaeagnus pungens / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents possessing cytotoxicity activity from Elaeagnus pungens.</p><p><b>METHOD</b>The constituents were separated through repeated chromatographic methods and their structures were elucidated by spectral analysis.</p><p><b>RESULT</b>Five compounds were isolated from the ethyl acetate ether extract of leaves of E. pungens. Their structures were elucidated as 4-hydroxybenzoic acid (1), 3, 3'-dimethoxyquercetin (2), caffeic acid methyl ester (3), methyl 3, 4-dihydroxybenzoate (4), spingic acid (5), 4-methoxylbenzoic acid (6), 3-methylkaempferol (7), kaempferol-3-O-beta-D-glucoside (8), dausosterol (9).</p><p><b>CONCLUSION</b>Compounds 1-8 were isolated from this plant for the first time.</p>

Establishment and biological properties of hybridoma cell lines secreting anti-IBDV idiotypic antibodies / 生物工程学报

In recent years, the prevention and cure of infectious bursal disease (IBD) have become more and more difficult due to the emergence of very virulent strains of infectious bursal disease virus (vvIBDV) and the variant strains of IBDV. In this research, the hybridoma cell lines which secretes anti-idiotypic antibodies against anti-IBDV IgG were established. According to the Jerne's theory of immune network, the use of the anti-idiotypic antibodies as a vaccine will be a new method for the prevention of IBD. In this study, the SPF chickens were inoculated with the IBDV- SD strain, and the bursal was obtained from the died chickens. The bursal was then homogenized and frozen-thawed 3 cycles, and the virus samples were prepared by cane sugar density gradient centrifugation and dialysis. Typical IBDV particles were observed under an electron microscope, and the concentration of the virus protein measured by ultraviolet absorbance spectrophotometry was 10.8 mg/mL. SPF chickens were immunized with the virus and the highly immunized sera were prepared and purified by Sulfuric acid ammonia salt out and Sephadex G-25 chromatography. Then, Balb/C mice of six or eight weeks old were immunized interapertoneally(I. P.) with purified antibodies to IBDV at regular intervals. SP2/0 myeloma cells were fused with the spleencytes from the immunized mice at a ratio of 10:1, in 50% polyethylene glycol (1540) and were then cultured in HAT until all the SP2/0 cells died. The hybridoma cells were selected by ELISA and the highly positive holes were cloned 3 times with the method of limited dilution. Two strains (2B6 strain,5F4 strain) of hybridoma cells were obtained, which were shown by ELISA to steadily secrete anti-IBDV idiotypic antibodies. The chromosome number of the two hybridoma cells were about 88 - 106, 95 in average, and the antibodies secreted belonged to the types of IgG1 and Kappa. Balb/c mice of 3 months old were inoculated I.P. with about 10(7) hybridoma cells per capita, and the ascites were collected 12 days later and the titre of anti-IBDV idiotypic antibodies measured by ELISA was 1 :25600 (for 2B6) and 1:12800 (for 5F4) . The ascites containing the anti-IBDV idiotypic antibodies were emulsified with complete or incomplete Freund's adjuvants, and the anti-IBDV idiotypic antibody vaccine was obtained. SPF and common Jingbai chickens were immunized with the vaccine obtained. The immunized chickens with the vaccine were inoculated with IBDV-SD strain at a dose of 2000 ELD50 after twoimmunizations. All the 10 SPF chickens in the non-immunized group were sick, and 8 of them died; and 5 out of the 50 SPF chickens immunized group got sick and 2 died. All the 10 common Jingbai chickens in the control group were sick, and 6 died; 7 of the 30 immunized common Jingbai chickens got sick and only 1 died. Chi2 analysis showed that the difference between the immunized and the non-immunized groups in both the SPF and the common Jingbai chickens were significant (P < 0.01). Our result indicated that the anti-IBDV idiotypic antibody vaccine well protected chickens and had a great potential in both research and clinical application.

The thinking about modern biological technology / 生物工程学报

The way of life and mode of thinking of mankind is being changed by modern biological technology. It may be come true again that coexist and evolution of man and nature because the development of modern biological technology, but it also cannot avoid produce some new problem which made people have a think deeply to biological warfare, ethics and morals, law, society, food safety, production of industry and agriculture, energy resources, environment.