Design, construction and evaluation of 1a/JFH1 HCV chimera by replacing the intergenotypic variable region

Peer reviewedPublisher PD

The Use of Microalgae for Coupling Wastewater Treatment With CO2 Biofixation

Production and emission of CO2 from different sources have caused significant changes in the climate, which is the major concern related to global warming. Among other CO2 removal approaches, microalgae can efficiently remove CO2 through the rapid production of algal biomass. In addition, microalgae have the potential to be used in wastewater treatment. Although, wastewater treatment and CO2 removal by microalgae have been studied separately for a long time, there is no detailed information available on combining both processes. In this review article, microalgae-based CO2 biofixation, various microalgae cultivation systems,̄ and microalgae-derived wastewater treatment are separately discussed, followed by the concept of integration of CO2 biofixation process and wastewater treatment. In each section, details of energy efficiency and differences across microalgae species are also given

Lentinan and β-glucan extract from shiitake mushroom, Lentinula edodes, alleviate acute LPS-induced hematological changes in mice

Objective(s): Immunomodulatory activity of β-glucans of shiitake mushroom (Lentinula edodes) has been known. We investigated whether β-glucans from L. edodes would attenuate the acute effects of lipopolysaccharides (LPS) on peripheral hematological parameters in mice.Materials and Methods: An in-house β-glucans extract (BG) prepared from fruiting bodies of shiitake mushroom L. edodes was chemically measured and characterized using spectrophotometry and HPLC. Male BALB/c mice directly inhaled aerosolized LPS of 3 mg/ml and were treated with BG or commercial β-glucan (known as lentinan; LNT) (10 mg/kg bw) at 1 hr before or 6 hr after LPS inhalation. The blood samples were collected by cardiac puncture from euthanized mice at 16 hr post-treatment. Results: The results showed a significant reduction in levels of blood parameters, including red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), and platelets (PLT); and a significant increase in blood lymphocyte counts in LPS-treated mice as compared with the control mice (P≤0.05). Total white blood cells, neutrophils, and monocyte counts did not show any significant difference among the groups. Treatment of LPS-challenged mice with LNT or BG significantly increased the levels of RBC, HGB, HCT, and PLT; and reduced blood lymphocyte counts as compared with LPS-treated mice (P≤0.05).Conclusion: These findings suggest that β-glucans from L. edodes might be effective in attenuating the effects of inhaled LPS on peripheral blood parameters. Thus, these findings might be useful in acute inflammatory diseases particularly pulmonary infectious diseases in which the hematological parameters would be affected

Characterization of anti-enteroviral activity of heparan sulphate mimetic compounds

Enterovirus 71 (EV71) infection remains a public health problem at a global level, particularly in the Asia-pacific region. The infection normally manifests as hand-foot-mouth disease (HFMD); however, it is capable of developing into potentially fatal neurological complications. There is currently no approved vaccine or antiviral substance available for prevention or treatment of EV71 infection. There has been no research undertaken to examine the possible antiviral activity of heparan sulphate (HS) mimetics against the Human Enterovirus A (HEV-A), in particular EV71. Therefore, this PhD research began with the aim of investigating the antiviral potencies of HS mimetics against EV71 infection. Initially, a colorimetric-based method was developed for the titration of EV71 strains, whereby the viral titre was quantified more precisely. Three soluble HS mimetics including heparin (Hep), HS, and pentosan polysulphate (PPS) were then shown to substantially inhibit a cloned strain of EV71 from infecting in Vero cells. Further investigations revealed that the compounds most likely exerted their antiviral action through interference with the EV71 attachment. The role of cell surface HS in mediating viral infection was then studied for several clinical isolates of HEV-A and HEV-B in Vero cells as well as a human neuroblastoma cell line, SK-N-SH. The findings revealed that the clinical isolate of EV71 utilizes low sulphated domains of cellular HS to bind to Vero cells, in contrast to Coxsackievirus B4 (CVB4), Coxsackievirus A16 (CVA16), and the cloned EV71. In the neural cells, Hep and PPS significantly prevented both clinical EV71 and clinical CVA16 binding and infections, although it could not be confirmed whether the viruses utilize cellular HS to bind to the cells. Finally, an Affymetrix DNA microarray was performed to gain insight into the mechanisms of action of Hep against the clinical EV71 infection in the neural cells. The results showed many genes with significant down- or up-regulation across the undermentioned conditions: negative control cells, compound control (cells treated with Hep only), virus control (cells treated with virus only), and treatment control (EV71-infected cells treated with Hep). Several genes were finally found to be targets for the anti-EV71 activity of Hep in SK-N-SH cells using a strict multi-level selection procedure. In parallel, the results revealed the significant induction of more than 1000 genes by EV71 infection with expression fold changes ranged from +46.5 to -10.7. The findings of this research may suggest new directions for studies of designing molecular drug targets against EV71 infection

Development of antiviral agents toward Enterovirus 71 infection

Enterovirus 71 (EV71) infection remains a public health problem at a global level, particularly in the Asia-Pacific region. The infection normally manifests as hand-foot-mouth disease; however, it is capable of developing into potentially fatal neurological complications. There is currently no approved vaccine or antiviral substance available for the prevention or treatment of EV71 infection. This paper, thus, reviews efforts to develop or discover synthetic as well as naturally occurring compounds directed against EV71 infection. The recent achievements in cellular receptors of EV71 are also highlighted, and their contribution to the development of antiviral drugs against EV71 is discussed in this article

Global impact of Heparin on gene expression profiles in neural cells infected by Enterovirus 71

Objectives: Heparan sulphate mimetics, particularly heparin (Hep), have previously been shown to considerably inhibit infection of enterovirus 71 (EV71) in Vero cells. Therefore, in this study, a genome-wide DNA microarray was performed to gain insight into the mechanism(s) of action of Hep against infection of a human neural cell line, SK-N-SH, with a clinical strain of EV71. Methods: This study focused on a selection of EV71-induced genes whose expression profiling was exclusively affected by the antiviral activity of Hep. The selection procedure was performed through a statistical multi-level comparison with the following controls: negative control cells, compound control (cells treated with Hep only), virus control (cells treated with virus only) and treatment control (EV71-infected cells treated with Hep). Results: Overall, of more than 30,000 genes studied, 14 well-known annotated genes were selected that may be targets for the antiviral activity of Hep against EV71 infection in neural cells. For most of these genes, Hep appeared to modulate the impact of EV71 infection on the expression pattern of the genes. Conclusions: The findings of this research may provide initial assistance in new directions for studies to design molecular drug targets against EV71 infection. (C) 2013 S. Karger AG, Base

Initial evidence on differences among Enterovirus 71, Coxsackievirus A16 and Coxsackievirus B4 in binding to cell surface heparan sulphate

Cell surface heparan sulphate (HS) mediates infection for many viruses from diverse families. We demonstrated significant antiviral potencies for a number of HS mimetics against a cloned strain of Enterovirus 71 (EV71) in a previous study. Thus, the involvement of HS in mediating viral infection of isolates of human enteroviruses was investigated in Vero and human neural cells in the present work. In both cell lines, heparin and pentosan polysulphate significantly inhibited both infection and attachment of low passage clinical isolates of EV71 and Coxsackievirus A16 (CVA16) but showed no affect on Coxsackievirus B4 (CVB4) (p < 0.05). In addition, enzymatic removal of cell surface HS by heparinase I prevented binding of the clinical EV71 by nearly 50 % but failed to significantly inhibit CVA16 or CVB4 binding in Vero cells. Overall, the findings of this study provides evidence that whilst highly sulphated domains of HS serve as an essential attachment co-receptor for EV71, HS might be used as an alternative attachment receptor by the other member of Human Enterovirus group A, CVA16. In addition, HS may not mediate early infection in CVB4

International journal of central banking : IJCB

The 50 % tissue culture infectious dose (TCID50) is still one of the most commonly used techniques for estimating virus titers. However, the traditional TCID50 assay is time consuming, susceptible to subjective errors and generates only quantal data. Here, we describe a colorimetric-based approach for the titration of Enterovirus 71 (EV71) using a modified method for making virus dilutions. In summary, the titration of EV71 using MTT or MTS staining with a modified virus dilution method decreased the time of the assay and eliminated the subjectivity of observational results, improving accuracy, reproducibility and reliability of virus titration, in comparison with the conventional TCID50 approach (p < 0.01). In addition, the results provided evidence that there was better correlation between a plaquing assay and our approach when compared to the traditional TCID50 approach. This increased accuracy also improved the ability to predict the number of virus plaque forming units present in a solution. These improvements could be of use for any virological experimentation, where a quick accurate titration of a virus capable of causing cell destruction is required or a sensible estimation of the number of viral plaques based on TCID50 of a virus is desired

In vitro evaluation of the antiviral activity of heparan sulfate mimetic compounds against Enterovirus 71

Enterovirus 71 (EV71) is the causative agent of hand foot and mouth disease (HFMD) and can also cause fatal neurological complications for which currently there is no vaccine or approved antiviral drug. Despite suggestions that heparan sulfate (HS)-like compounds are effective antivirals against various viruses, no research has been undertaken to examine their effects upon EV71. Therefore, this study aimed to investigate the in vitro anti-EV71 effect of HS mimetics (heparin, heparan sulfate, and pentosan polysulfate). The results revealed that all of the compounds exhibited significant antiviral actions (p < 0.05) against EV71 at concentrations less than 250 μg/mL, compared to virus control and positive control, ribavirin. Among the compounds, heparin exhibited the most potent antiviral activity, as 7.81 μg/mL of it prevented the infection by more than 90% (p < 0.05). Assays to reveal the mode of action revealed that all of the compounds were capable of exerting antiviral activity through hindrance of viral attachment to the cells. In addition, some of the compounds could inhibit viral replication when added to cells 1 h before infection, but none significantly reduced viral penetration. Overall, this research revealed that HS mimetic compounds could inhibit EV71 infection, and that HS may be involved in EV71–host cell interactions, as the virus binding to the host cells was significantly hindered by the HS-like compounds but not by ribavirin. Thus, further investigations to discover the molecular mechanisms underlying the anti-EV71 action of HS-like compounds are warranted