BBI blocks LPS-mediated inhibitory effect on tight junction protein of intestinal epithelial cells / 中国感染控制杂志

Objective To evaluate the blocking effect and mechanism of Soybean-derived Bowman-Birk inhibitor (BBI)on LPS-mediated downregulation for tight junction protein(HT-29 cells)in intestinal epithelial cells(IECs). Methods The toxic effect of LPS and BBI on HT-29 cells was detected by CCK8 Kit.HT-29 cells were pretreated by BBI for 6 hours prior to LPS stimulation, the expression of tight junction protein(ZO-1 and Occludin), TLR4, and MyDD8 was detected by the quantitative real-time polymerase chain reaction(PCR)and Western Blot;activation of NF-κB was measured by Western Blot.Results LPS(1 000ng/mL)and BBI(1 000μg/mL)showed no cytotoxicity on HT-29 cells.LPS could significantly upregulate the expression of TLR4 in HT-29 cells, the up-regulation had time-dose effect, and could significantly downregulate the expression of tight junction protein, the down-regulation effect was directly proportional to the concentration of LPS, could activate NF-κB, and had dose effect, effect of LPS on HT-29 cells could be significantly inhibited by BBI.Conclusion By inhibiting the expression of TLR4 and activation of NF-κB in IECs induced by LPS, BBI can significantly block the LPS-mediated inhibitory effect on tight junction protein in intestinal epithelial cells.

Pathogenic detection of infectious diarrhea in patients in a district of Beijing from 2011 to 2013 / 中国感染控制杂志

Objective To analyze the distribution and pulsed-field gel electrophoresis (PFGE)of pathogenic bacteria causing infectious diarrhea in a district of Beijing from 2011 to 2013,and provide basis for tracing infection sources.Methods A total of 1 179 stool specimens of infectious diarrhea from patients in a diarrhea outpatient department from January 2011 to December 2013 were collected,all isolated pathogens were identified by serotyping and PFGE analysis.Results 330 enteric pathogens were isolated from 1 179 specimens,the top 4 bacteria were Shi-gella spp .(28.18%,n=93),Salmonella spp .(20.91 %,n=69),Vibrio parahaemolyticus (13.33%,n =44),and diarrheagenic Escherichia coli (3.33%,n = 11 ).18 Shigella sonnei isolates were identified as 8 PFGE patterns, clustering similarity was close to 88%;69 Salmonella spp .strains belonged to 18 serotypes and 41 PFGE patterns, Salmonella senftenberg and Salmonella enteritidis had dominant patterns;no dominant PFGE patterns were obviously identified among 23 strains ofVibrio parahaemolyticus .Conclusion The serotypes and PFGE patterns of pathogenic bacteria in infectious diarrhea in past three years showed a wide distribution characteristics,the dominant PFGE patterns of Salmonella spp .and Shigella spp .need to be paid more attention,and outbreak of infectious diarrhea caused by Salmonella spp .and Shigella spp .should be alerted.

Inhibition of hepatitis C virus replication by mycophenolic acid in hepatocytes / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>It is well known that cyclosporine A (CsA), a widely used immunosuppressant for clinical organ transplantation, has the ability to inhibit HCV replication. In this study, the effects of several other immunosuppressants, including mycophenolic acid (MPA), rapamycin and FK-506, on HCV replication were examined in human hepatocytes.</p><p><b>METHODS</b>HCV JFH-l-infected hepatocytes were treated with immunosuppressants or with control vehicles. The levels of viral RNA and the expression of HCV core protein were determined by quantitative real-time RT-PCR and Western Blot assay, respectively.</p><p><b>RESULTS</b>MPA-treated cells showed significant decreases in both viral RNA and HCV Core protein expression compared with the control cells. Moreover, MPA treatments of hepatocytes before, during or after HCV infection could significantly inhibit viral replication. In contrast, rapamycin and FK-506 had little effect on HCV replication. Mechanism research disclosed that the inhibition of HCV replication by MPA was mainly due to its depletion of guanosine, a purine nucleoside crucial for synthesis of guanosine triphosphate (GTP), which is required for initiation of HCV RNA replication. The supplement of exogenous guanosine could reverse most of anti-HCV effect of MPA.</p><p><b>CONCLUSION</b>These results indicate that MPA, through the depletion of guanosine, inhibits HCV JFH-1 replication in hepatocytes, suggesting that MPA may be beneficial for HCV-infected transplant recipients.</p>

Study on the distribution of hepatitis C virus genotypes in patients visiting one methadone maintenance clinic in Wuhan / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the prevalence of hepatitis C virus (HCV) infection and characteristics on molecular biology related to HCV among patients who were enrolled in a Methadone maintenance clinic in Wuhan.</p><p><b>METHODS</b>Serum samples from 332 injection drug users (IDUs) were obtained and anti-HCV IgG was detected by enzyme linked immunosorbrent assay(ELISA), together with 86 anti-HCV positive specimens genotyped. A reverse transcriptase-polymerase chain reaction (RT-nPCR) assay using conserved primers deduced from the core-envelopel (C-E1) region of the HCV genome was employed to amplify a 474 bp fragment. Phylogenetic analysis of the C-E1 sequences was conducted by direct sequencing of the RT-nPCR products and alignment with determined by nucleotide sequencing followed by composition of a phylogenetic tree.</p><p><b>RESULTS</b>There were 313 cases (94.3%) appeared positive anti-HCV IgG in the 332 patients from a Methadone maintenance clinic in Wuhan. It was demonstrated that there were four different subtypes of HCV in that clinic in Wuhan, including 6a--71 cases (82.5%), 3b--7 cases (8.2%), 1a--5 cases (5.8%) and 1b--3 cases (3.5%).</p><p><b>CONCLUSION</b>Infection of 6a genotype HCV was predominant in patients from the Methadone maintenance clinic in Wuhan, followed by HCV 3b, 1a and 1b.</p>

Preliminary Discussion on the Structure of a Novel Housefly Pupae Lectin / 中国生物工程杂志

In order to provide plenty of information about the relationship between its structure and function,the structure of a novel housefly pupae D-galactose binding lectin with the molecular weight 55kDa and immune acitivity was analyzed preliminarily.In the first place,oligosaccharide chain was confirmed to be existed in this kind of novel housefly pupae lectin by the method of gel staining,and then its structure was analyzed with the help of protein sequencing instrument,spectrophotometer color contrast,?-elimination reaction,infrared spectroscopy and atomic force microscopy.This kind lectin was a global-shaped monomer with the diameter 75 nm or so and the protein and oligosaccharide content 97.36% and 2.1% respectively.Peptide chain and oligosaccharide chain was linked by O-glycoside bond with the N-terminal blocked and the sugar ring alpinum type.All above was the reliable theory for further analysis of structure.