108 research outputs found

    Protective effects of Sm-p80 in the presence of resiquimod as an adjuvant against challenge infection with Schistosoma mansoni in mice

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    SummaryObjectivesTo determine the prophylactic efficacy of an Sm-p80-based vaccine formulation against challenge infection with Schistosoma mansoni in mice using an approach comprising of initial priming with DNA and boosting with recombinant protein in the presence of resiquimod (R848) as an adjuvant.MethodsIn the first experiment (prime–boost approach), mice were primed with Sm-p80–pcDNA3 (week 0) and boosted at weeks 4 and 8 with recombinant Sm-p80 formulated in resiquimod (R848). Each mouse in the control group first received only pcDNA3 and was boosted with R848. In the second set of experiments (recombinant protein approach), mice were immunized (week 0) and boosted (weeks 4 and 8) with rSm-p80 formulated in R848. Animals of the control group in this series of experiments received only R848 at 0, 4, and 8 weeks. All of the animals from both the ‘prime–boost’ and ‘recombinant protein’ groups were challenged with cercariae of S. mansoni, 4 weeks after the last immunization. The mice were sacrificed 6 weeks post-challenge and the reductions in worm burden and egg production were determined. Sm-p80-specific antibody titers were estimated in the mice sera by ELISA. Cytokine mRNA and protein production by proliferating splenocytes in response to in vitro stimulation with Sm-p80, were estimated via RT-PCR and ELISA, respectively.ResultsVaccination with Sm-p80 (prime–boost approach) showed 49% reduction in worm burden; with the recombinant protein approach the protection was found to be 50%. The protection levels were correlated with antibody production. Upon antigenic stimulation with recombinant Sm-p80, splenocytes secreted significant levels of interferon (IFN)-γ and interleukin (IL)-2, indicating that the immune responses were Th1-biased and this was further supported in terms of distribution of antibody isotypes and mRNA expression of cytokines.ConclusionsIn conclusion the present study clearly demonstrates that Sm-p80 consistently maintained its protective nature, and resiquimod as an immunopotentiating agent slightly boosted the protective effects of Sm-p80 in both ‘DNA prime–protein boost’ and ‘recombinant protein’ immunization approaches in a murine model

    Synthesis of N'-Substituted-2-(5-(4-Chlorophenyl)-1,3,4- oxadiazol-2-ylthio)acetohydrazide Derivatives as Suitable Antibacterial Agents

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    Purpose: To evaluate antibacterial activity of a series of molecules bearing 1,3,4-oxadiazole and azomethine moieties.Methods: The 4-chlorobenzoic acid (1) was precursor to N'-substituted-2-(5-(4-chlorophenyl)-1,3,4- oxadiazol-2-ylthio)acetohydrazide, 8a-p, through a multistep synthesis of corresponding ester, 2, hydrazide, 3 and 1,3,4-oxadiazole, 4. The molecule, 4, was subjected to electrophilic substitution by ethyl-2-bromoacetate to yield 5 which was stepped to 2-(5-(4-chlorophenyl)-1,3,4-oxadiazol-2- ylthio)acetohydrazide (6). The target molecules, 8a-p, were synthesized by nucleophilic addition of 6 to arylaldehydes, 7a-p. The proposed structures of all the synthesized molecules were elucidated by Infra Red (IR), Proton Nuclear Magnetic Resonance (1H-NMR) and Electron Impact Mass Spectrometry (EIMS) spectral data. Antibacterial activity was evaluated by the principle that microbial growth is in a log phase of growth and so results in increased absorbance of broth medium which is observed.Results: The molecule, 8b, was active against S. aureus and 8c against S. typhi only. The molecule, 8p, was the most active against S. typhi with minimum inhibitory concentration (MIC) value of 10.04 ± 1.25 ΌM while 8e was active against E. coli with MIC of 9.45 ± 1.00 ΌM, both relative to the reference standard, ciprofloxacin, which displayed MIC of 9.13 ± 2.00 and 8.90 ± 1.65 ΌM, respectively.Conclusion: Most of the synthesized molecules exhibit 50 % antibacterial activity relative to the reference. Molecules 8b and 8c are the least active compounds.Keywords: 1,3,4-Oxadiazole, 4-Chlorobenzoic acid, Antibacterial activity, Azomethin

    The Phytophthora RXLR Effector Avrblb2 Modulates Plant Immunity by Interfering With Ca2+ Signaling Pathway

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    In plants, subcellular fluctuations in Ca2+ ion concentration are among the earliest responses to biotic and abiotic stresses. Calmodulin, which is a ubiquitous Ca2+ ion sensor in eukaryotes, plays a major role in translating these Ca2+ signatures to cellular responses by interacting with numerous proteins located in plasma membranes, cytoplasm, organelles and nuclei. In this report, we show that one of the Phytophthora RXLR effector, Avrblb2, interacts with calmodulin at the plasma membrane of the plant cells. Using deletion and single amino acid mutagenesis, we found that calmodulin binds to the effector domain of Avrblb2. In addition, we show that most known homologs of Avrblb2 in three different Phytophthora species interact with different isoforms of calmodulin. Type of amino acids at position 69 in Avrblb2, which determines Rbi-blb2 resistance protein-mediated defense responses, is not involved in the Avrblb2-calmodulin interaction. Using in planta functional analyses, we show that calmodulin binding to Avrblb2 is required for its recognition by Rpi-blb2 to incite hypersensitive response. These findings suggest that Avrblb2 by interacting with calmodulin interfere with plant defense associated Ca2+ signaling in plants

    Agency cost, corporate governance and ownership structure: the case of Pakistan

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    The article attempts to investigate the role of ownership structure and corporate governance in mitigating agency cost in a sample of 50 firms selected on the basis of market capitalization from “Karachi Stock Exchange” during the period 2003 to 2006. We used the proxy asset utilisation ratio to measure agency cost. Multivariate fixed effect regression is used to analyze the data. The explanatory variables include director ownership, institutional ownership, external ownership, board size, CEO/Chair duality, remuneration structure and board independence. The results show that higher director and institutional ownership reduces the level of agency cost. Smaller sized boards also results in lowering agency cost. Board independence has positive association with asset utilisation ratio. The separation of the post of CEO and chairperson and higher remuneration lower agency cost

    Synthesis, Structural Analysis and Screening of Some Novel 5-Substituted Aryl/Aralkyl-1,3,4-Oxadiazol-2-Yl 4-(Morpholin-4-Ylsulfonyl)Benzyl Sulfides as Potential Antibacterial Agents

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    A series of new 5-substituted aryl/aralkyl-1,3,4-oxadiazol-2-yl 4-(morpholin-4-ylsulfonyl)benzyl sulfides 6a-k were synthesized by converting multifarious aryl/aralkyl organic acids 1a-k successively into corresponding esters 2a-k, hydrazides 3a-k and 5-substituted aryl/aralkyl-1,3,4-oxadiazole-2-thiols 4a-k. Finally, the target compounds, 6a-k were prepared by stirring 5-substituted-1,3,4-oxadiazole-2-thiols with 4-(4-(bromomethyl)phenylsulfonyl) morpholine (5) in the presence of N,N-dimethylformamide (DMF) and sodium hydride (NaH). The structures of the newly synthesized compounds were elucidated by spectroscopic techniques. In addition, the anti-bacterial activity of all the synthesized compounds was investigated in vitro against Gram-positive and Gram-negative bacteria by using ciprofloxacin as reference standard drug and the results showed that some of the tested compounds possessed good anti-bacterial activity

    Analytical solution of an SEIV epidemic model by Homotopy Perturbation method

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    In this paper, we consider an SEIV epidemic model which represents the interection of infected and susceptible individuals in the population through horizontal transmission. We find the analytical solution of the proposed model by Homotopy perturbation method which is one of the best method for finding the solution of the nonlinear problem. By using this techniques, first, we solve the problem analytically and then compare the numerical results with other standards methods. We also justfy the numerical simulation and their results. Mostly nonlinear problem have upon some difficulties, and their solution is some time difficult to obtain. However, this techniques help us to obtain their approximate as well as analytical solution just after few perturbation terms

    Synthesis and Evaluation of some New 5-Substituted-1,3,4- oxadiazol-2yl-4-(morpholin-4yl Sulfonyl)benzyl Sulfides as Antibacterial Agent

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    Purpose: To synthesise a new series of 5-substituted-1,3,4-Oxadiazol-2yl-4-(morpholin-4yl sulfonyl)benzyl sulfide and evaluate their antibacterial activity.Methods: Different organic acids were converted consecutively into corresponding esters, hydrazides and 5-substituted-1,3,4-Oxadiazol-2-thiols (4a-e). The targets, 6a-e were synthesized by stirring 4a-e with 4-(4-(bromomethyl)phenylsulfonyl) morpholine (5) in the presence of N,N-dimethylformamide (DMF) and sodium hydride (NaH). All the structures were elucidated by modern spectroscopic techniques and screened against bacteria using standard procedure and ciprofloxacin drug as positive control.Results: The yield of the synthesized compounds (4a-e and 6a-e) were moderate (65 - 90 %). Compounds 6a-e had antibacterial activity against Pseudomonas aeruginosa, Bacillis subtilis and Staphylococcus aureus while some had activity against the other bacteria used. One of the compounds, 6b, exhibited significant activity against all the bacterial strains, i.e., S. typhi (-), E. coli (-), K. pneumoniae (-), P. aeruginosa (-), B. subtilis (+) and S. aureus (+) with  MIC (ΌM) values of 11.01 ± 0.31, 15.37 ± 3.33, 16.11 ± 1.14, 9.70 ± 1.96, 10.01 ± 2.70 and 9.15 ± 0.29, respectively. However, none of the compounds had any inhibitory activity against any bacteria as high as that of ciprofloxacin.Conclusion: Five new compounds with antibacterial activities have been synthesized. Their potential as therapeutic agents is, however, yet to be evaluated.Keywords: 1,3,4-Oxadiazole, Benzyl sulfide, 4-(4-(bromomethyl)phenylsulfonyl)morpholine, Spectral analysis, Antibacterial activit

    Implementing Visual Analytics Pipelines with Simulation Data

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    Visual analytics has been widely studied in the past decade both in academia and industry to improve data exploration, minimize the overall cost, and improve data analysis. In this chapter, we explore the idea of visual analytics in the context of simulation data. This would then provide us with the capability to not only explore our data visually but also to apply machine learning models in order to answer high-level questions with respect to scheduling, choosing optimal simulation parameters, finding correlations, etc. More specifically, we examine state-of-the-art tools to be able to perform these above-mentioned tasks. Further, to test and validate our methodology we followed the human-centered design process to build a prototype tool called ViDAS (Visual Data Analytics of Simulated Data). Our preliminary evaluation study illustrates the intuitiveness and ease-of-use of our approach with regards to visual analysis of simulated data

    Correlation of severity of COVID-19 disease with gastrointestinal manifestations and liver injury - A north Brooklyn community hospital experience: A retrospective cohort study

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    Introduction: The primary receptor for SARS-CoV-2 infection, angiotensin-converting enzyme-2 (ACE-2), is expressed in the gastrointestinal tract and liver parenchyma. The involvement of the gastrointestinal tract with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has remained unclear. The following study retrospectively reviews gastrointestinal symptoms and liver function tests at the time of hospital admission to identify patient outcomes including prolonged hospital stay, the requirement for intensive care, and all-cause in-hospital 30-day mortality.Methods: A retrospective review of patient charts at the Woodhull Medical and Mental Health Center (WMC) was conducted at the time of hospital admission, using a pre-determined selection criterion. All adult patients, both inpatient and outpatient, were included from March 2020 till May 2020. A 95% confidence interval was used to estimate the odds ratio (OR) for patient outcomes.Results: Of the 520 patients, gastrointestinal symptoms including nausea (OR = 0.375, p = 0.015), and nausea and vomiting in combination (OR = 0.400, p = 0.016) had an inverse protective relationship with all-cause in-hospital 30-day mortality among COVID-19 patients. Gastrointestinal symptoms including diarrhea (OR = 1.008, p \u3c 0.001), and nausea and vomiting (OR = 1.291, p = 0.043) had a mild impact on the length of hospital stay.Conclusion: Elevated liver transaminases including alanine transaminase (ALT) and aspartate transaminase (AST) at the time of hospital admission can predict critical care requirement and all-cause 30-day hospital mortality in patients with COVID-19 infection. Presence of gastrointestinal symptoms is associated with worsened outcomes
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