A3G-induced mutations show a low prevalence and exhibit plus-strand regional distribution in hepatitis B virus DNA from patients with non-hepatocellular carcinoma (HCC) and HCC.

APOBEC3G (A3G) cytidine deaminase is an innate immune restriction factor that can edit and inhibit hepatitis B virus (HBV) replication. The preferred target of A3G is deamination of the third cytosine of 5'CCC to form a mutant marker 5'CC C → K. However, the distribution of A3G-induced mutations on HBV DNA during infection is not well characterized. To provide clarity, we obtained the HBV DNA sequences from HBV infected individuals with and without hepatocellular carcinoma (HCC and non-HCC, respectively), from the NCBI database, and calculated the r values of A3G-induced 5'CC C → K mutation prevalence in HBV DNA. A3G-induced mutations were weakly prevalent and mainly distributed in the plus strand of HBV DNA (r = 1.407). The mutations on the minus strand were weaker (r = .8189). There were A3G-induced mutation regions in the 1200 to 2000 nt region of the plus strand and the 1600 to 1500 nt region of the minus strand. There was no significant difference in the r values of A3G-induced mutations in HBV DNA between the HCC and non-HCC groups. However, the rvalue of the plus strand 2400 to 2800 nt regions of HCC derived HBV DNA (r = 4.2) was significantly higher than that of the same regions of non-HCC derived HBV DNA (r = 1.21). These findings clarify the weak prevalence and preferred plus-strand distribution of A3G-induced mutations on HBV DNA from HCC and non-HCC. These findings may provide valuable clues regarding the interaction mechanism between A3G and HBV DNA and inform HCC screening.

A long-acting isomer of Ac-SDKP attenuates pulmonary fibrosis through SRPK1-mediated PI3K/AKT and Smad2 pathway inhibition.

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening lung disease with a poor prognosis. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a critical negative regulator of fibrosis development. However, it's extremely short half-life greatly limits its applications. Previously, we reported an Ac-SDKP analog peptide in which Asp and Lys residues were replaced with D-amino acids (Ac-SDD KD P). Ac-SDD KD P exhibits better resistance to angiotensin-1-converting enzyme (ACE)-mediated degradation and a longer half-life than Ac-SDKP in rat and human sera. The objective of this study was to explore the potential application of Ac-SDD KD P for the treatment of IPF and to clarify the underlying mechanisms. We found that Ac-SDD KD P exerted similar antifibrotic effects as Ac-SDKP on human fetal lung fibroblast-1 (HFL-1) proliferation, α-smooth muscle actin (α-SMA), collagen I and collagen III expression, and Smad-2 phosphorylation in vitro. In vivo, Ac-SDD KD P exhibited significantly greater protective effects against bleomycin-induced pulmonary fibrosis than Ac-SDKP in mice. α-SMA, CD45, collagen I and collagen III expression, and Smad-2 phosphorylation were significantly decreased in the lungs of Ac-SDD KD P-treated but not Ac-SDKP-treated mice. Furthermore, a pull-down experiment was used to screen for molecules that interact with Ac-SDKP. Co-immunoprecipitation (Co-IP) and computer-based molecular docking experiments demonstrated an interaction between Ac-SDKP or Ac-SDD KD P (Ac-SDKP/Ac-SDD KD P) and serine/arginine-rich protein-specific kinase 1 (SRPK1) that caused inhibition SRPK1-mediated phosphatidylinositol-3 kinase/ serine/threonine kinase (PIK3/AKT) signaling pathway activation and Smad2 phosphorylation and thereby attenuated lung fibrosis. Our data suggest that long-acting Ac-SDD KD P may potentially be an effective drug for the treatment of pulmonary fibrosis. The interacting molecule and antifibrotic mechanism of Ac-SDKP/Ac-SDD KD P were also identified, providing an experimental and theoretical foundation for the clinical application of the drug.

Distribution and difference of APOBEC-induced mutations in the TpCpW context of HBV DNA between HCC and non-HCC.

Hepatitis B virus (HBV) DNA is vulnerable to editing by human apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) cytidine deaminases. However, the distribution of APOBEC-induced mutations on HBV DNA is not well characterized. To this end, we obtained the HBV DNA sequence of HBV-infected individuals with and without hepatocellular carcinoma (HCC and non-HCC groups, respectively) from NCBI database and calculated the rapo values of APOBEC-induced TpCpW→TpKpW mutation prevalence in HBV DNA. The results showed that the APOBEC-induced mutations were mainly distributed in the minus strand of non-HCC-derived HBV DNA (rapo = 2.04), while the mutation on the plus-strand was weaker (rapo = 0.99). There were high APOBEC-induced mutation regions in the minus strand of HBV DNA 1 to 1000 nucleotides (nts) region and in the plus-strand of HBV DNA 1000 to 1500 nts region; the mutations in the 1 to 1000 nts region were mainly TpCpW→TpTpW mutation types (total T/G: 111/18) and a number of these were missense mutations (missense/synonymous: 35/94 in P gene, 17/15 in S gene, and 5/10 in X gene). The difference between minus to plus-strand rapo of HCC-derived HBV DNA (1.96) was greater than that of the non-HCC group (1.05). The minus-strand rapo of HCC-derived HBV DNA regions 1000 to1500nts and 1500 to 2000 nts (rapo = 4.2 and 4.2) was also higher than that of the same regions of non-HCC-derived HBV DNA (rapo = 1.2 and 1.1). Finally, the ratio of minus to plus-strand rapo was used to distinguish HCC-derived HBV DNA from non-HCC-derived HBV DNA. This study unraveled the distribution characteristics of APOBEC-induced mutations on double strands of HBV DNA from HCC and non-HCC samples. Our findings would help understand the mechanism of APOBECs on HBV DNA and may provide important insights for the screening of HCC.

miR-99b-targeted mTOR induction contributes to irradiation resistance in pancreatic cancer.

BACKGROUND: Radiation exerts direct antitumor effects and is widely used in clinics, but the efficacy is severely compromised by tumor resistance. Therefore uncovering the mechanism of radioresistance might promote the development of new strategies to overcome radioresistance by manipulating activity of the key molecules. METHODS: Immunohistochemistry were used to find whether mTOR were over-activated in radioresistant patients' biopsies. Then Western blot, real-time PCR and transfection were used to find whether radiotherapy regulates the expression and activity of mTOR by modulating its targeting microRNA in human pancreatic cancer cell lines PANC-1, Capan-2 and BxPC-3. Finally efficacy of radiation combined with mTOR dual inhibitor AZD8055 was assessed in vitro and in vivo. RESULTS: Ionizing radiation promoted mTOR expression and activation in pancreatic cancer cells through reducing miR-99b expression, which negatively regulated mTOR. Novel mTOR inhibitor, AZD8055 (10 nM, 100 nM, 500 nM) synergistically promoted radiation (0-10 Gy) induced cell growth inhibition and apoptosis. In human pancreatic cancer xenografts, fractionated radiation combined with AZD8055 treatment further increased the anti-tumor effect, the tumor volume was shrinked to 278 mm3 after combination treatment for 3 weeks compared with single radiation (678 mm3) or AZD8055 (708 mm3) treatment (P < 0.01). CONCLUSIONS: Our data provide a rationale for overcoming radio-resistance by combined with mTOR inhibitor AZD8055 in pancreatic cancer therapy.

Rapid high-throughput genotyping of HBV DNA using a modified hybridization-extension technique.

China has the highest incidence of hepatitis B virus (HBV) infection worldwide. HBV genotypes have variable impacts on disease pathogenesis and drug tolerance. We have developed a technically simple and accurate method for HBV genotyping that will be applicable to pre-treatment diagnosis and individualized treatment. Multiple sequence alignments of HBV genomes from GenBank were used to design primers and probes for genotyping of HBV A through H. The hybridization was carried out on nitrocellulose (NC) membranes with probes fixed in an array format, which was followed by hybrid amplification by an extension step with DNA polymerase to reinforce the double-stranded DNA hybrids on the NC membrane and subsequent visualization using an avidin-biotin system. Genotyping results were confirmed by DNA sequencing and bioinformatics analysis using the National Center for Biotechnology Information genotyping database, and compared with results from the line probe assay. The data show that multiple sequence alignment defined a 630 bp region in the HBV PreS and S regions that was suitable for genotyping. All genotyping significant single nucleotides in the region were defined. Two-hundred-and-ninety-one HBV-positive serum samples from Northwest Chinese patients were genotyped, and the genotyping rate from the new modified hybridization-extension method was 100% compared with direct sequencing. Compared with line probe assay, the newly developed method is superior, featuring reduced reaction time, lower risk of contamination, and increased accuracy for detecting single nucleotide mutation. In conclusion, a novel hybridization-extension method for HBV genotyping was established, which represents a new tool for accurate and rapid SNP detection that will benefit clinical testing.

Development and evaluation of a paramagnetic nanoparticle based immunochromatographic strip for specific detection of 2009 H1N1 influenza virus.

Influenza A/H1N1 virus spreads worldwide and has been a threat to human health and the poultry industry. Although H1N1 lateral-flow immunoassay strips are available for the detection of 2009/A/H1N1 antigens, the specificity and sensitivity of these strips are limited. Because of the monodispersity, the strong magnetic signal and the stable brown color of superparamagnetic nanoparticles, which were employed in this study as label instead of commonly used colloidal gold particles. Two different monoclonal anti-HA (hemagglutinin) and anti-HA-tag mAbs were paired for conjugating with paramagnetic beads and immobilizing on the surface of nitrocellulose (NC) membrane as capture antibody respectively. After optimizing the experimental condition, we generated a superparamagnetic bead-based immunochromatographic strip. The strip could detect HA antigen from H1N1 influenza A virus sample sensitively, its detection limit was 100 pg/mL. It had low cross reactivity with H3N2 influenza A virus and did not detect influenza B virus. It had no false positive detection in all of the tested control samples. With the help of magnetic assay reader (MAR), the magnetic intensity on test lines could be recorded and quantified proportionally with the amount of antigens captured. Those properties were indeed superior to the colloidal gold-based strips. More importantly, the strip was affordable and easy to use. Conceivably, superparamagnetic bead-based immunochromatographic strip should be a valuable point-of-care test for the rapid and specific detection of influenza A virus.

Hepatitis B viral core protein disrupts human host gene expression by binding to promoter regions.

BACKGROUND: The core protein (HBc) of hepatitis B virus (HBV) has been implicated in the malignant transformation of chronically-infected hepatocytes and displays pleiotropic functions, including RNA- and DNA-binding activities. However, the mechanism by which HBc interacts with the human genome to exert effects on hepatocyte function remains unknown. This study investigated the distribution of HBc binding to promoters in the human genome and evaluated its effects on the related genes' expression. RESULTS: Whole-genome chromatin immunoprecipitation microarray (ChIP-on-chip) analysis was used to identify HBc-bound human gene promoters. Gene Ontology and pathway analyses were performed on related genes. The quantitative polymerase chain reaction assay was used to verify ChIP-on-chip results. Five novel genes were selected for luciferase reporter assay evaluation to assess the influence of HBc promoter binding. The HBc antibody immunoprecipitated approximately 3100 human gene promoters. Among these, 1993 are associated with known biological processes, and 2208 regulate genes with defined molecular functions. In total, 1286 of the related genes mediate primary metabolic processes, and 1398 encode proteins with binding activity. Sixty-four of the promoters regulate genes related to the mitogen-activated protein kinase (MAPK) pathways, and 41 regulate Wnt/beta-catenin pathway genes. The reporter gene assay indicated that HBc binding up-regulates proto-oncogene tyrosine-protein kinase (SRC), type 1 insulin-like growth factor receptor (IGF1R), and neurotrophic tyrosine kinase receptor 2 (NTRK2), and down-regulates v-Ha-ras Harvey rat sarcoma viral oncogene (HRAS). CONCLUSION: HBc has the ability to bind a large number of human gene promoters, and can disrupt normal host gene expression. Manipulation of the transcriptional profile in HBV-infected hepatocytes may represent a key pathogenic mechanism of HBV infection.

Accuracy assessment of pharmacogenetic algorithms for warfarin dose prediction in Chinese patients.

A few warfarin pharmacogenetic dosing algorithms have been proposed,based on multiethnic or homogeneous populations, to estimate warfarin therapeutic doses. However, it remains to be proven that which algorithm is accurate in predicting warfarin dose in Chinese people. We selected eight warfarin dose predictive pharmacogenetic algorithms and retrospectively assessed the predictive accuracy of each algorithm in a total of 368 eligible outpatients by comparing the actual stable therapeutic dose to the dose predicted by the algorithm. Our results showed that a high level of performance was demonstrated by three algorithms,Gage et al., Anderson et al., and Wu et al., having a similar performance in coefficient of determination (R2) and percentage of patients predicted dose within 20% of actual dose. The Gage et al. algorithm had the lowest mean absolute error (MAE). These results indicated that the algorithm by Gage et al. provided a more accurate prediction than did the others,which suggests that this pharmacogenetic algorithm might be used in clinical practice to guide rational administration of warfarin.

The natural YMDD mutations of hepatitis B virus in Western China.

BACKGROUND: To provide a scientific basis for clinical genetic diagnosis before lamivudine treatment in hepatitis B virus (HBV) patients, the rate of natural YMDD mutations in Western China and the correlations between YMDD mutations and several factors were investigated in this study. METHODS: A pyrosequencing approach for detecting YMDD mutations was first developed. The sensitivity of the pyrosequencing approach was determined by assaying polymerase chain reaction (PCR) products generated from 10-fold serial dilutions of HBV DNA and PCR products from mixed control plasmids with different ratios. Natural YMDD mutations in Western China were evaluated by analyzing the clinical samples from HBV patients who had no experience of using lamivudine, and the existence of YMDD mutants was further confirmed by real-time PCR. RESULTS: With the developed pyrosequencing approach, YMDD mutations could be determined within 2 h after PCR amplification. About 10 copies of HBV DNA per reaction were required to obtain sufficient PCR products to produce clear and accurate pyrosequencing patterns. The pyrosequencing approach developed had the capacity to detect minor mutants; most HBV mutants in samples were minor ones. The rate of natural YMDD mutations in Western China was 15.56%. The hepatitis B e antigen (HBeAg) level in serum was correlated with YMDD mutations. CONCLUSIONS: In Western China, natural YMDD mutations occur at a rate of 15.56%, and it is suggested that pyrosequencing be performed to detect YMDD mutations before lamivudine treatment in patients with a chronic HBV infection.

QKI degradation in macrophage by RNF6 protects mice from MRSA infection via enhancing PI3K p110ß dependent autophagy.

BACKGROUND: Sepsis is a fatal condition commonly caused by Methicillin-resistant Staphylococcus aureus (MRSA) with a high death rate. Macrophages can protect the host from various microbial pathogens by recognizing and eliminating them. Earlier we found that Quaking (QKI), an RNA binding protein (RBP), was involved in differentiation and polarization of macrophages. However, the role of QKI in sepsis caused by pathogenic microbes, specifically MRSA, is unclear. This study aimed to investigate the role of QKI in regulation of host-pathogen interaction in MRSA-induced sepsis and explored the underlying mechanisms. METHODS: Transmission electron microscope and immunofluorescence were used to observe the autophagy level in macrophages. Real-time PCR and western blot were used to analyzed the expression of mRNA and protein respectively. The potential protein interaction was analyzed by iTRAQ mass spectrometry and Immunoprecipitation. RNA fluorescence in situ hybridization, dual-luciferase reporter assay and RNA immunoprecipitation were used to explore the mechanism of QKI regulating mRNA of PI3K-p110ß. RESULTS: The mRNA level of QKI was aberrantly decreased in monocytes and PBMCs of septic patients with the increasing level of plasma procalcitonin (PCT). Then the mice with myeloid specific knockout of QKI was challenged with MRSA or Cecal Ligation and Puncture (CLP). Mice in these two models displayed higher survival rates and lower bacterial loads. Mechanistically, QKI deletion promoted phagocytosis and autophagic degradation of MRSA via activating p110ß (a member of Class IA phosphoinositide 3-kinases) mediated autophagic response. QKI expression in macrophages led to the sequestration of p110ß in mRNA processing (P) bodies and translational repression. Upon infection, the direct interaction of RNF6, a RING-type E3 ligase, mediated QKI ubiquitination degradation and facilitated PI3K-p110ß related autophagic removal of pathogen. The administration of nanoparticles with QKI specific siRNA significantly protected mice from MRSA infection. CONCLUSIONS: This study disclosed the novel function of QKI in the P body mRNA regulation during infection. QKI degradation in macrophage by RNF6 protects mice from MRSA infection via enhancing PI3K-p110ß dependent autophagy. It suggested that QKI may serve as a potential theranostic marker in MRSA-induced sepsis.

Evidence that methylation of hepatitis B virus covalently closed circular DNA in liver tissues of patients with chronic hepatitis B modulates HBV replication.

Epigenetic factors may modulate chronic Hepatitis B viral infection by affecting virion gene transcription. The aim of this study was to compare the methylation status of the intrahepatic covalently closed circular DNA (cccDNA) CpG island 2 and HBV replication capability. HBV cccDNA was extracted from liver biopsies of 55 HBsAg-positive patients with chronic hepatitis B (32 HBeAg-positive and 23 HBeAg-negative), and was analyzed for methylation status and quantity. The two Hpa II recognition sequences CCpGG in the CpG island 2 were methylated in infected liver tissues from 24 (43.6%) of 55 patients. Positive ratios of cccDNA methylation were significantly higher in HBeAg-negative patients (15/23, 65.2%) than HBeAg-positive patients (9/32, 28.1%) (P < 0.05). The percentage of methylated-cccDNA/total-cccDNA of HBeAg-negative samples (a median of 48%, ranging from 5% to 83%) was significantly higher (P < 0.001) than HBeAg-positive samples (a median of 14%, ranging from 0.26% to 35%). Ratios of relaxed circular DNA (rcDNA) to cccDNA molecules revealed that cccDNA methylation correlated with impaired virion productivity in HBeAg-positive individuals (P < 0.05). The bisulfite DNA sequencing showed that methylation density was significantly higher in HBeAg-negative than in HBeAg-positive patients (P < 0.05). The methylation level of the CpG island 2 of the cccDNA in HBeAg-negative patients was higher than that in HBeAg-positive patients, suggesting that HBV cccDNA methylation may be relevant to replication capability of HBV.

Dynamic Halbach array magnet integrated microfluidic system for the continuous-flow separation of rare tumor cells.

Circulating tumor cells (CTCs), the most representative rare cells in peripheral blood, have received great attention due to their clinical utility in liquid biopsy. The downstream analysis of intact CTCs isolated from peripheral blood provides important clinical information for personalized medicine. However, current CTC isolation and detection methods have been challenged by their extreme rarity and heterogeneity. In this study, we developed a novel microfluidic system with a continuously moving Halbach array magnet (dHAMI microfluidic system) for negative isolation CTCs from whole blood, which aimed to capture non-target white blood cells (WBCs) and elute target CTCs. The dynamic and continuous movement of the Halbach array magnet generated a continuous magnetic force acting on the magnetic bead-labelled WBCs in the continuous-flow fluid to negatively exclude the WBCs from the CTCs. Furthermore, the continuously moving magnetic field effectively eliminated the effect of magnetic bead aggregation on the fluid flow to realize the continuous-flow separation of the CTCs without a sample loading volume limitation. The experimental procedure for CTC negative isolation using the dHAMI microfluidic system could be completed within 40 min. Under the optimized experimental conditions of the dHAMI microfluidic system, including the flow rate and concentration of the immunomagnetic bead, the average CTC capture rate over a range of spiked cell numbers (50-1000 cancer cells per mL) was up to 91.6% at a flow rate of 100 µL min-1. Finally, the CTCs were successfully detected in 10 of 10 (100%) blood samples from patients with cancer. Therefore, the dHAMI microfluidic system could effectively isolate intact and heterogeneous CTCs for downstream cellular and molecular analyses, and this robust microfluidic platform with an excellent magnetic manipulation performance also has great application potential for the separation of other rare cells.

[Cloning,expression and activity identification of human innate immune protein apolipoprotein B mRNA editing enzyme catalytic subunit 3A(APOBEC3A)].

Objective: To construct the expression vector of apolipoprotein B mRNA editing enzyme catalytic subunit 3A( APOBEC3A),express APOBEC3 A in eukaryotic cells and identify its cytosine deaminase activity. Methods: The APOBEC3 A gene was obtained by PCR and inserted into the eukaryotic expression vector pc DNA3. 0( +). The recombinant vector pc DNA3. 0-APOBEC3 A was then transfected into HEK293 T and Hep G2 cells after confirmed by DNA sequencing. The recombinant protein was purified by Ni-NTA His Bind affinity column. Western blot analysis was used to detect the expression of APOBEC3 A protein. The localization of APOBEC3 A protein in HEK293 T and Hep G2 cel s was identified by immunofluorescence cytochemistry. The deaminase activity of APOBEC3 A protein was characterized by fluorescence polarization. Results: DNA sequencing confirmed that APOBEC3 A gene( 600 bp) was inserted into pc DNA3. 0-APOBEC3 A,which was expressed in HEK293 T and Hep G2 cells successfully. APOBEC3 A protein was mainly expressed in cytoplasm of HEK293 T cells and cytoplasm and nuclei of Hep G2 cells. APOBEC3 A protein showed cytosine deaminase activity on the TTCA sequence in single-stranded DNA. Conclusion: The study constructed successfully APOBEC3 A eukaryotic expression vector,identified the differential expression of APOBEC3 A protein in HEK293 T and Hep G2 cells,and confirmed that the APOBEC3 A protein had cytosine deaminase activity.

[Expression and activity identification of APOBEC3A-HBc fusion protein].

Objective To construct the expression vector of the fusion protein of apolipoprotain B mRNA editing enzyme catalytic polypeptide-like 3A (APOBEC3A) and hepatitis B virus core proteins (HBc) with different sequences, and identify its expression, intracellular localization and cytosine deamination activity. Methods The APOBEC3A gene and the coding sequence of HBc and four kinds of truncated HBc containing C-termimal domain were amplified by PCR. The APOBEC3A with full-length HBc antigen or four kinds of truncated HBc were cloned into a eukaryotic expression vector pcDNA3.0 by In-Fusion method, and confirmed by DNA sequencing. The recombinants were then transfected into HEK293T cells. The expression and localization of the fusion proteins were detected by Western blotting and immunofluorescence cytochemistry. The cytosine deamination activity was analyzed by electrophoresis on a urea denaturing polyacrylamide gel. Results Five kinds of fusion protein were expressed in HEK293T cells successfully, and the expression of the vectors containing the truncated HBc were higher than that of the APOBEC3A-HBc vector containing the full-length HBc. The fusion protein of APOBEC3A-HBc was mainly expressed in the cytoplasm of HEK293T cells, and the fusion proteins of APOBEC3A-HBc144S, APOBEC3A-HBc144E, APOBEC3A-HBc144AAA, APOBEC3A-HBc144A were expressed mainly in the nuclei of HEK293T cells. The cytosine deamination activity of the fusion proteins containing the truncated HBc was higher than that of the fusion protein APOBEC3A-HBc. Conclusion The fusion protein expression vectors of APOBEC3A and HBc with different lengths and sequences have been constructed successfully. The expressing ability, intracellular localization and cytosine deamination activity are obviously different between the fusion protein APOBEC3A-HBc and the fusion proteins containing the truncated HBc.

[Over-expression of uracil DNA glycosylase 2 (UNG2) enhances the resistance to oxidative damage in HepG2 cells].

Objective To investigate the uracil glycosidic enzyme activity of uracil DNA glycosylase 2 (UNG2) and study the role of UNG2 in the resistance of antioxidant stress of HepG2 cells. Methods The UNG2-expressing vector was built. Western blotting was used to detect the expression of UNG2. Immunofluorescence staining was performed to observe the cellular location of UNG2. Oligonucleotide was used as substrate for the determination of the UNG2 glycosidic enzyme activity. H2O2 toxicity assay was done to study the function of UNG2 in the antioxidant resistance of hepatocellular carcinoma HepG2 cells. Results UNG2 was successfully over-expressed in HEK293FT cells, and UNG2 was found to be mainly located in nucleus. Enzyme activity assay showed that UNG2 had significant oligonucleotide dU glycosidic enzyme activity. H2O2 toxicity assay showed that over-expressed UNG2 could remarkably increase the survival of HepG2 cells after exposed to H2O2. Conclusion UNG2 possesses specific DNA glycosidic enzyme activity, and it can protect HepG2 cells against oxidative stress damage.

[Pollution Characteristics, Source Analysis and Potential Ecological Risk Assessment of Heavy Metals in Soils Surrounding a Municipal Solid Waste Incineration Plant in Shanghai].

The contents of ten heavy metals (As, Cu, Cd, Cr, Pb, Ni, Zn, Ti, Mn, and Hg) were determined in the surface soils surrounding a municipal solid waste incineration plant in Shanghai using atomic spectroscopy. The spatial distribution and sources of the detected heavy metals were studied by enrichment factor and multivariate statistical and spatial interpolation analyses. In addition, their potential ecological risk was assessed. The results showed that all heavy metals, except Hg and As, were detected with mean contents ranging from 0.399 to 4220 mg·kg-1. The mean contents of Cu, Cd, Cr, Pb, Ni, Zn, and Mn were higher than their respective background values in Shanghai. In particular, the mean content of Cd was 2.9 times its background value. The results of the Pearson's correlation, principle component, enrichment factor, and spatial distribution analyses of these heavy metals indicated that Ti, Mn, and Ni primarily originated from natural sources, while Cd, Cr, Cu, Pb, and Zn originated from industrial manufacturing, combustion, and traffic emissions. The potential ecological risk assessment showed that soils surrounding the municipal solid waste incineration plant suffered from a moderate-level risk. The mean value of the potential ecological risk index of these detected heavy metals was 108.92, of which Cd contributed as high as 79.63%, deserving much attention.

A novel fluorescence polarization based assay for 14 human papillomavirus genotypes in clinical samples.

A specific and practical method was developed for high throughput 14 human papillomavirus (HPV) genotypes assay in clinical samples by a single PCR. GP5+/6+ polymerase chain reaction (PCR) system was used to amplify HPV DNA in 1127 samples. The PCR product was assayed by AcycloPrime reaction with fluorescence polarization (FP). Fourteen HPV genotypes specific sequence primers designed within GP5+/GP6+ amplification polymorphism regions of L1 genes for corresponding HPV genotypes were annealed with the type specific PCR products and special fluorescent terminator was added to the end of the primer under direction of the PCR products. AcycloPrime-FP analysis showed specific anneal and incorporation without any cross-reaction. The types detected with FP showed an excellent overall agreement with sequence when the individual monotype results were taken into account. The proposed method could detect more than one type of HPV infection, but the sequence method was limited. AcycloPrime-FP could reach the detection level: 100 ag for representative phylogenetically distant HPV genotypes: HPV6, 18, 31, 39, 42, 51 and 58. The results of AcycloPrime-FP showed excellent reproducibility. The proposed method allowed an economical detection of HPV genotypes without any use of labeled probe. It is expected to be an extremely useful tool for HPV genotypes screening.

Detection of H. pylori antibody profile in serum by protein array.

AIM: To detect multiple H. pylori antibodies in serum samples of individuals who carry H. pylori by protein array. METHODS: Recombinant H. pylori antigens, urease B subunit (UreB), vacuolating toxin A (VacA) and cytotoxin associated gene A protein (CagA), were prepared and immobilized in matrixes on nitrocellulose membrane by robotics to bind the specific immunoglobulin G (IgG) antibodies in serum. Staphylococcus protein A (SPA) labeled by colloid gold was used to integrate the immuno-complex and gave red color signal. The scanner based on charge-coupled device (CCD) could collect the image signal and convert it into digital signal. RESULTS: When human IgG was printed on the membrane in increasing concentrations and incubated with immunogold, a linear dose response curve was obtained and the detection limit for IgG was about 0.025 ng. The cutoff values, which were defined as the mean grey level plus 3 times of standard deviation, were 27.183, 28.546 and 27.402, for anti-UreB IgG, anti-CagA IgG and anti-VacA IgG, respectively, as 400 human serum samples with negative H. pylori antibodies were detected by the protein array. When 180 serum samples from patients in hospital were employed for detection of IgG against UreB, CagA and VacA, the sensitivity of the protein array was 93.4%, 95.4%, 96.0%, and the specificity was 94.8%, 94.4% and 97.5%, respectively, as compared with the results obtained by ELISA. The assay also showed high reproducibility, uniformity and stability, and the results were available within 30 min. CONCLUSION: The protein array is a very practical method for rapid detection of multiple antibodies in serum samples. It is especially useful for large scale epidemiological investigation of the infection of H. pylori.

A microarray-based gastric carcinoma prewarning system.

AIM: To develop a microarray-based prewarning system consisting of gastric cancer chip, prewarning data and analysis software for early detection of gastric cancer and pre-cancerous lesions. METHODS: Two high-density chips with 8,464 human cDNA sites were used to primarily identify potential genes specific for normal gastric mucosa, pre-cancerous lesion and gastric cancer. The low-density chips, composed of selected genes associated with normal gastric mucosa, precancerous lesion and gastric cancer, were fabricated and used to screen 150 specimens including 60 specimens of gastric cancer, 60 of pre-cancerous tissues and 30 of normal gastric mucosa. CAD software was used to screen out the relevant genes and their critical threshold values of expression levels distinguishing normal mucosa from pre-cancerous lesion and cancer. All data were stored in a computer database to establish a prewarning data library for gastric cancer. Two potential markers brcaa1 and ndr1 were identified by Western blot and immunohistochemistry. RESULTS: A total of 412 genes associated with three stages of gastric cancer development were identified. There were 216 genes displaying higher expression in gastric cancer, 85 genes displaying higher expression in pre-cancerous lesion and 88 genes displaying higher expression in normal gastric mucosa. Also 15 genes associated with metastasis of gastric cancer and 8 genes associated with risk factors were screened out for target genes of diagnosis chip of early gastric cancer. The threshold values of 412 selected genes to distinguish gastric cancer, pre-cancerous lesion from normal gastric mucosa were defined as 6.01+/-2.40, 4.86+/-1.94 and 5.42+/-2.17, respectively. These selected 412 genes and critical threshold values were compiled into an analysis software, which can automatically provide reports by analyzing the results of 412 genes obtained by examining gastric tissues. All data were compiled into a prewarning database for gastric cancer by CGO software. Northern blot and immunohistochemistry analysis confirmed that gene and protein of brcaa1 displayed lower expression in normal gastric mucosa and higher expression in gastric cancer tissues, conversely, ndr1 displayed lower expression in gastric cancer and higher expression in normal gastric mucosa. CONCLUSION: The microarray-based prewarning system for gastric cancer was developed. This system consisted of gastric cancer-associated gene chip, prewarning data and analysis software, which has a high potential for applications in the early detection of gastric cancer. The two potential markers brcaa1 and ndr1 identified may be used to distinguish cancer status fand non-cancer status.

The hepatitis B virus (HBV) core protein enhances the transcription activation of CRE via the CRE/CREB/CBP pathway.

We previously reported that hepatitis B virus core protein (HBc) can bind to the Enhancer I (Enh I) domain and can accumulate with transcription coactivator cAMP response element (CRE). This raises the possibility that HBc may interact with CRE/CREB and regulate CRE transcription activation. In this study, we investigated the function and mechanisms of HBc in regulating CRE transcriptional activation using the HepG2 cell line. Our results showed the following: (1) HBc expression significantly increases HBV CRE transcriptional activation; (2) phosphorylation of the serine residues in the arginine-rich domain (ARD) of HBc protein impacts the function of transcriptional activation by the CRE; (3) HBc protein significantly increases HBV CRE transcriptional activation following forskolin treatment; (4) HBc nonspecifically binds to CRE and enhances the binding of the cAMP response element-binding protein (CREB) to CRE; and (5) HBc increases the concurrent accumulation of CREB and CBP at the CRE region. HBc activates Enh I through its binding to CRE, increasing the concurrent accumulation of CREB/CBP on CRE, and thus increases CRE transcriptional activation.