To simplify the preparation of neuraminidase in screening influenza neuraminidase inhibitors,the neuraminidase gene of H5N1 influenza A virus was optimized for high expression in mammalian cells and cloned into pcDNA4/TO vector. The recombinant plasmids were transfected into T-REx 293 cells to establish stable cell lines,in which the expression of neuraminidase was induced by tetracycline. Unlike from virions,the preparation of neuraminidase became conveniently and safely from these stable cell lines,which would facilitate developing high throughput assay to screen neuraminidase inhibitors. More than 3000 natural extracts and herbal components were screened in the study. Baicalin and baicalein were found to inhibit oseltamivir-sensitive and oseltamivir-resistant neuraminidase at similar level,furthermore,their anti-influenza activity was confirmed by plaque assay and virus inhibition assay.

AIM: To observe the change of TNF-? mRNA in hypertrophic cardiac myocytes induced by pressure overload in rats and the effect of captopril. METHODS: Serum and heart were collected 42 days after the cardiac hypertrophy model made by pressure overload by abdomen aorta-constriction (AC). Hypertrophic parameter and the concentration of TNF-? in serum and left ventricle were determined by ELISA. TNF-? mRNA in cardiac myocytes was determined by in situ hybridization and analyze by ELIA image analysis system. The orientation of (TNF-?) mRNA in cardiac myocytes was also observed. RESULTS: Left ventricle hypertrophy was observed 42 days after operation. TNF-? mRNA in AC group elevated 98% compared to sham-operated group and descended 64.14% by captopril ((P