Comparision on the effect of RT-LAMP and LAMP method for detection of Mycobacterium tuberculosis / 中国人兽共患病学报

We compared the RT-LAMP,LAMP and L-J for detecting MTB to provide the rapid diagnosis method for tu-berculosis.In this assay,NTM and other common respiratory bacteria were used to detect specificity,Mycobacterium tubercu-losis specific products were identified by restriction enzyme digestion.To detect sensitivity,we used RT-LAMP,LAMP and L-J to detect 100 cases sputum specimens from patients with tuberculosis and 22 cases control sputum specimens,the 10 times dilution of 1 ng/μL H37Rv standard strains was used to detect RT-LAMP limit.The results showed that the positive rate of RT-LAMP,LAMP and L-J were 100%,92%,88%.RT-LAMP and L-J,RT-LAMP and LAMP were statistically signifi-cant,RT-LAMP had 10 times higher sensitivity than LAMP,RT-LAMP not only to identify viable but also capable of detec-ting a single copy of MTB.So RT-LAMP is superior to LAMP and L-J and is practical for use in primary medical care institu-tion or peripheral laboratory.

Study of using an individualized treatment strategy to treat patients with chronic hepatitis C / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the outcomes of chronic hepatitis C (CHC) patients treated with antiviral regimens of interferon (IFN) plus ribavirin (RBV) using individualized doses and durations.</p><p><b>METHODS</b>This study was designed as an open-label, prospective clinical trial to analyze the virological responses of 169 CHC patients who received individualized dosages of IFNa-2b or pegylated (Peg)IFNa-2a combined with RBV based on their weight ( less than 60 kg or more than or equal to 60 kg), age (less than 65 years or 65-75 years), morbid state (liver cirrhosis or not), and complications (such as heart disease, diabetes, thyroid disorder). Treatment duration was calculated using the time required to induce HCV RNA negativity. The rates of virological response and adverse effects among the different groups were compared.</p><p><b>RESULTS</b>The IFNa-2b treatment was given to 116 patients, and PegIFNa-2a was given to 53 patients. Compared to the IFNa-2b group, the PegIFNa-2a group showed significantly higher rates of complete early virological response (cEVR; 76.7% vs. 92.5%, P less than 0.05) and sustained virological response (SVR; 53.6% vs. 92.3%, P less than 0.05) among the patients who had completed their course of treatment; the rapid virological response (RVR) rate was also higher for the PegIFNa-2a group but the difference did not reach statistical significance (48.7% vs. 60.4%, P more than 0.05). Seventy-eight patients received the routine dose, and 91 patients received the low dose; there were no significant differences between these two groups for RVR (53.8% vs. 58.9%, P more than 0.05), cEVR (78.0% vs. 80.8%, P more than 0.05), or SVR (65.5% vs. 58.3%, P more than 0.05).</p><p><b>CONCLUSION</b>Use of an individualized antiviral treatment strategy designed according to the patient's baseline condition, early viral kinetics, and tolerability to adverse reactions can achieve a high rate of SVR, as well as improve the safety, prognosis, and cost-effectiveness associated with treating CHC patients.</p>

Relation of IL-17 polymorphisms and serum levels in patients with chronic HCV infection / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the association of single nucleotide polymorphisms (SNPs) in the interleukin 17 (IL-17) gene and serum protein levels in patients with chronic hepatitis C virus (HCV) infection.</p><p><b>METHODS</b>A total of 228 patients with chronic HCV infection and 81 healthy controls were enrolled in the study. The frequencies of IL-17 rs8193036 and rs2275913 polymorphisms were detected by the TaqMan SNP genotyping assay. Serum levels of IL-17 protein were detected by ELISA. Pairwise comparisons were made by the Chi-square test, and the significance of between-group differences was assessed by the Student's t-test with P less than 0.05.</p><p><b>RESULTS</b>The patients with chronic HCV infection and the healthy controls showed similar frequencies of the rs8193036 C/T allele (x2 = 1.428, P = 0.232) and the rs2275913 A/G allele (x2 = 0.106, P = 0.744). In addition, the two groups showed similar distribution of the rs8193036 CC (chronic HCV infection: 46.49% vs. healthy controls: 41.98%), CT (45.61% vs. 44.44%) and TT (7.89% vs. 13.58%) genotypes (x2 = 2.346, P = 0.309), and of the rs2275913 AA (16.23% vs. 13.58%), AG (48.25% vs. 50.62%) and GG (35.53% vs. 35.80%) genotypes (x2 = 0.340, P = 0.844). Subgroup analysis of chronic HCV infection patients stratified according to HCV genotypes 1 and 2 showed no differences in the distribution of rs8193036 and rs2275913 alleles (x2 = 1.127, P = 0.288; x2 = 1.088, P = 0.297) and genotypes (x2 = 2.825, P = 0.246; x2 = 0.970, P = 0.616). However, the chronic HCV infection group did show significantly higher levels of serum IL-17 than the controls (97.67+/-39.68 vs. 71.60+/-19.78 pg/ml, t = 2.414, P = 0.033).</p><p><b>CONCLUSION</b>Chronic HCV infection is associated with increased serum IL-17; however, the IL-17 polymorphisms rs8193036 and rs2275913 were not associated with chronic HCV infection susceptibility in this study's Chinese cohort.</p>

Stable cell line for secretion of replication-defective hepatitis B virus vector expressing blasticidin resistant gene / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct a stable cell line with permanent secretion of recombinant hepatitis B virus (HBV) vector, which express blasticidin resistant gene.</p><p><b>METHODS</b>Replication-defective HBV vector, pCH-BsdR, which express blasticidin resistance gene was constructed by deleting the HBV genes and inserting the blasticidin resistance gene into the S region. The G418-resistant, the packaging signal deleted HBV helper plasmid, pcDNA3.1-CH3142, and the HBV vector pCH-BsdR were cotransfected into HepG2 cells. Cell clones were selected by the adding of both blasticidin and G418, then serial detection were done.</p><p><b>RESULTS</b>After 36 cell clones were picked and expanded. Three cell clones were defined as the best. Quantity of their HBV DNA were 4.1 x 10(6), 3.6 x 10(6) and 1.2 x 10(6) copies/ml, respectively. Enveloped recombinant, but not wild type HBV were confirmed in the culture medium.</p><p><b>CONCLUSIONS</b>The stable cell lines can realize large preparation of recombinant HBV virions. This will contribute to the use of HBV vector for gene therapy and HBV susceptible cell lines screening.</p>

Study on anti-HBV effects of genetically engineered replication-defective hepatitis B virus expressing dominant negative mutants of core protein / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To explore the possibility of using HBV as a gene delivery vector, and to test the anti-HBV effects by intracellular expression of dominant negative mutants of core protein.</p><p><b>METHODS</b>Two kinds of full length mutant HBV genome, which express Core-partial P and Core-S fusion protein, were transfected into HepG 2.2.15 cell lines. Positive clones were selected and mixed in respective groups with hygromycin in the culture medium. HBsAg and HBeAg, which exist in the culture medium, were tested by ELISA and intracellular HBc related HBV DNA was examined by dot blot hybridization. The existence of recombinant HBV virion in the culture medium was examined by PCR.</p><p><b>RESULTS</b>The mean inhibitory rates of HBsAg were 2.74+/-3.83%, 40.08+/-2.05% (P less than 0.01) and 52.94+/-1.93% (P less than 0.01) in group 2.2.15-pMEP4, 2.2.15-CP and 2.2.15-CS, respectively. The mean inhibitory rates of HBeAg were 4.46+/-4.25%, 52.86+/-1.32% (P less than 0.01) and 41.60+/-1.65% (P less than 0.01), respectively. The inhibitory rates of HBc related HBV DNA were 15.3%, 82.0% and 67.2%, respectively. Recombinant HBV virion was detectable in the culture medium of only group 2.2.15-CP.</p><p><b>CONCLUSION</b>Dominant negative mutants of core protein can efficiently suppress wt-HBV replication and the expressions of HBV antigens. With the help of wild-type HBV, the recombinant HBV genome can form and secret HBV like particles, which provides evidence that the antiviral gene will be hepatotropic expression and the antiviral effects will be amplified.</p>

Development of hygromycin-resistant packaging cell line for hepatitis B virus-derived vectors / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To cooperate with the study of HBV vector, hygromycin-resistant packaging cell line was developed that allows encapsidation of plasmids into HBV particles.</p><p><b>METHODS</b>Free of packaging signal, HBV genome was inserted into plasmid pMEP4, which expresses the HBV structural proteins including core, pol and preS/S proteins. HepG2 cell lines were employed to transfect with the construct. Hygromycin selection was done at a concentration of 150 micrograms/ml in the culture medium. The hygromycin-resistant clones with the best expressions of HBsAg and HBcAg were theoretically considered as packaging cell line and propagated under the same conditions. It was infected with recombinant retrovirus vector and hen selected with G418 and hygromycin in the culture medium. The existence of recombinant HBV virion in the culture medium was examined by PCR.</p><p><b>RESULTS</b>Hygromycin-resistant HBV packaging cell line was generated, which harbored an HBV mutant whose packaging signal had been deleted. Expressions of HBsAg and HBcAg were detectable. Infected with recombinant retrovirus pRV-CP, the hygromycin-resistant packaging cell line was found to secrete mutant HBV particles and no wild-type HBV was detectable in the culture medium.</p><p><b>CONCLUSION</b>After the packaging signal was deleted and transfected into HepG2 cell lines, the partial HBV genome lost its ability to form wild-type HBV, but conserves cis-action providing structural proteins for the packaging of the replication-defective HBV.</p>

Approach to transforming hepatitis B virus as a gene therapeutic vector / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the possibility of hepatitis B virus (HBV) as a vector in liver-targeting gene therapy.</p><p><b>METHODS</b>A fragment containing the small envelope gene of HBV was replaced with the reporter gene green fluorescent protein (GFP) to construct the recombinant HBV vector, which was transfected into HepG2 cells with liposome. The expression of GFP was observed with fluorescence microscope. The HBV cccDNA was testified using semi-nest PCR. The viral particles of the recombinant HBV in culture medium were detected by PCR as well as Southern blot.</p><p><b>RESULTS</b>The HBV vector carrying the interesting gene of GFP could express the functional protein in the transfected hepatocytes. However, the recombinant HBV vector was replication-deficient, which could not be packed and replicated in the hepatocytes to secrete mature recombinant HBV particles carrying the interesting gene of GFP when transfected solely but could when cotransfected with the recombinant and helper construct which lacked part of 5'-proximal HBV RNA packaging signal epsilon.</p><p><b>CONCLUSION</b>It is possible that HBV is reconstructed as a liver-targeting vector for gene therapy.</p>

Anti-HBV effects of genetically engineered replication-defective HBV with combined expression of antisense RNA and dominant negative mutants of core protein and construction of first-generation packaging cell line for HBV vector / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the possibility of using HBV as a gene delivery vector, and to test the anti-HBV effects by intracellular combined expression of antisense RNA and dominant negative mutants of core protein.</p><p><b>METHODS</b>Full length of mutant HBV genome, which expresses core-partial P fusion protein and/or antisense RNA, was transfected into HepG2.2.15 cell lines. Positive clones were selected and mixed in respective groups with hygromycin in the culture medium. HBsAg and HBeAg, which exist in the culture medium, were tested by ELISA method. Intracellular HBc related HBV DNA was examined by dot blot hybridization. The existence of recombinant HBV virion in the culture medium was examined by PCR. Free of packaging signal, HBV genome, which express the HBV structural proteins including core, pol and preS/S proteins, was inserted into pCI-neo vector. HepG2 cell lines were employed to transfect with the construct. G418 selection was done at the concentration of 400mug/ml in the culture medium. The G418-resistant clones with the best expression of HBsAg and HBcAg were theoretically considered as packaging cell lines and propagated under the same conditions. It was transfected with plasmid pMEP-CPAS and then selected with G418 and hygromycin in the culture medium. The existence of recombinant HBV virion in the culture medium was examined by PCR.</p><p><b>RESULTS</b>The mean inhibitory rates of HBsAg were 2.74% 3.83%, 40.08 2.05% (t=35.5, P<0.01), 66.54% 4.45% (t=42.3, P<0.01), and 73.68% 5.07% (t=51.9, P<0.01) in group 2.2.15-pMEP4, 2.2.15-CP, 2.2.15-SAS, and 2.2.15-CPAS, respectively. The mean inhibitory rates of HBeAg were 4.46% 4.25%, 52.86% 1.32% (t=36.2, P<0.01), 26.36% 1.69% (t=22.3, P<0.01), and 59.28% 2.10% (t=39.0, P<0.01), respectively. The inhibitory rates of HBc related HBV DNA were 0, 82.0%, 59.9%, and 96.6%, respectively. Recombinant HB virion was detectable in the culture medium of all the three treatment groups. G418-resistant HBV packaging cell line, which harbored an HBV mutant whose packaging signal had been deleted, was generated. Expression of HBsAg and HBcAg was detectable. Transfected with plasmid pMEP-CPAS, it was found to secrete recombinant HB virion and no wild-type HBV was detectable in the culture medium.</p><p><b>CONCLUSIONS</b>It has stronger anti-HBV effects by combined expression of antisense RNA and dominant negative mutants than by individual expression of them. With the help of wild-type HBV, the modified HBV genome can form and secret HBV like particles, which provides evidence that the antiviral gene will be hepatotropic expression and the antiviral effects will be amplified. The packaging cell line can provide packaging for replication-defective HBV, but with low efficiency.</p>