[Preparation of vero cell-adapted influenza H5N1 virus strain by genetic reassortment].

OBJECTIVE: To prepare Vero cell-adapted influenza H5N1 virus strain by Genetic Reassortment and produce influenza H5N1 vaccine using Vero cell as a substrate. METHODS: Embryonated specific pathogen-free (SPF) hen's eggs and Vero cells were co-infected with Vero cell-adapted influenza virus A/Yunnan/1/2005 Va(H3N2) and A/Anhui/1/2005 (H5N1) via reverse genetics. The reassortant was screened with goat antibody against strain A/Yunnan/1/2005 Va(H3N2) and identified for subtype by hemagglutination-inhibition (HI) assays and gene analysis of HA and NA. RESULTS: A Vero cell-adapted influenza H5N1 virus strain was obtained, and there was no significant difference in serum antibody titers of monovalent inactivated vaccine reassorted before and after (F = 0.857, P > 0.05). CONCLUSION: The Vero cell-adapted influenza virus of epidemic strain may be reassortment between Vero cell-adapted and epidemic strains.

[Study on the alkaloids in the stems and leaves of Stephania cepharantha (II)].

OBJECTIVE: To study the alkaloids in the stems and leaves of Stephania cepharantha Hayata. METHODS: The dried stems and leaves of Stephania cepharantha Hayata were percolated with 95% ethanol and the solvent was removed by rotary evaporation to give a concentrate, and the concentrate was extracted by petroleum ether and chloroform. Column chromatograghy on MCI CHP 20P, silica gel, Rp-18, Sephadex LH-20 and polyamide were applied for the isolation and purification of the chloroform fraction. The structures were elucidated by their physicochemical properties and spectral data. RESULTS: Five alkaloids were obtained and identified as, Stephasunoline (I) Aknadinine (II), Discretamine (III), Acutumine (IV), Sinomenine (V). CONCLUSION: Compounds I, III, IV are isolated from this plant for the first time, and compound IV is isolated from the genus for the first time.