[C gene-targeting short hairpin RNA suppresses the replication and expression of hepatitis B virus in BHK-21 cells].

Objective: The vaccines currently developed against infectious diseases fail to induce effective antiviral immune responses to control an abrupt outbreak of viral diseases epidemic in a short space of time. Hence there is an urgent need to develop emergency vaccines capable of producing prophylactic effects against infectious diseases. RNA interference (RNAi) is a mechanism that inhibits gene expression by causing the degradation of specific RNA molecules or hindering the transcription of specific genes.

[Transfection of siRNA expressing plasmids targeting S gene inhibits replication and expression of hepatitis B virus in hepatic cancer cells].

Objective: To study the inhibitive effects of transfection of siRNA expressing plasmids targeting S gene, one of the 4 open reading frames of hepatitis B virus (HBV), on the replication and expression of HBV.

Methods: Two plasmids expressing 2 siRNAs targeting S gene, one of the 4 open reading frames of HBV (S1 and S2) and one nonspecific plasmid (siRNA-S3), as negative control, with the length of 21 nt heterologous to the HBV/U95551 genome were constructed, and then transfected into the hepatic cancer cells of the line HepG2.2.

A peptide of foot-and-mouth disease virus serotype Asia1 generating a neutralizing antibody response, and an immunostimulatory peptide.

The epitopes of the capsid of foot-and-mouth disease virus (FMDV) play important roles in the construction of highly immunogenic subunit vaccines. However few epitopes have been found for FMDV serotype Asia1. In this study we screened for epitopes of the VP1 and VP2 proteins of FMDV serotype Asia1 isolate, YNBS/58.

Constituents of Vittaria anguste-elongata and their biological activities.

Twelve new compounds, vittarin-A (1), -B (2), -C (3), -D (4), -E (5), -F (6), 3-O-acetylniduloic acid (7), ethyl 3-O-acetylniduloate (8), methyl 4-O-coumaroylquinate (9), vittarilide-A (10), and -B (11), and vittariflavone (12), as well as 20 known compounds have been isolated from the whole plant of Vittaria anguste-elongata. The structures of these compounds were determined by spectroscopic and chemical transformation methods. 5,7-Dihydroxy-3',4',5'-trimethoxyflavone (18) displayed moderate cytotoxicity against human lung carcinoma and central nervous system carcinoma cell lines with inhibition of 89 and 61% at a concentration of 58 microM, respectively.