95 research outputs found

    Epstein–Barr Virus MicroRNAs Are Evolutionarily Conserved and Differentially Expressed

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    The pathogenic lymphocryptovirus Epstein–Barr virus (EBV) is shown to express at least 17 distinct microRNAs (miRNAs) in latently infected cells. These are arranged in two clusters: 14 miRNAs are located in the introns of the viral BART gene while three are located adjacent to BHRF1. The BART miRNAs are expressed at high levels in latently infected epithelial cells and at lower, albeit detectable, levels in B cells. In contrast to the tissue-specific expression pattern of the BART miRNAs, the BHRF1 miRNAs are found at high levels in B cells undergoing stage III latency but are essentially undetectable in B cells or epithelial cells undergoing stage I or II latency. Induction of lytic EBV replication was found to enhance the expression of many, but not all, of these viral miRNAs. Rhesus lymphocryptovirus, which is separated from EBV by ≥13 million years of evolution, expresses at least 16 distinct miRNAs, seven of which are closely related to EBV miRNAs. Thus, lymphocryptovirus miRNAs are under positive selection and are likely to play important roles in the viral life cycle. Moreover, the differential regulation of EBV miRNA expression implies distinct roles during infection of different human tissues

    Critical success criteria for B2B E-commerce systems in Chinese medical supply chain.

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    The paper presents an exploratory investigation to determine and prioritise the critical success criteria, which can measure and guide the successful application and performance improvement of business to business e-commerce system (BBECS) in a medical supply chain's selling and buying functions, in the context of global business expansion. The research reveals that the buying and the selling functions have different prioritisations on the majority of the determined critical success measuring criteria. These criteria are categorised into three Critical Success Measuring Criteria Groups, for the selling and the buying functions, respectively, guiding medical supply chain members in harnessing the full advantage of a BBECS. For the selling function, the top critical success measuring criteria are as follows: integrating information searching/transmission and application processes, ensuring the reliability and timeliness of technical support, ensuring recognition and acceptance of e-commerce processes, displaying the organisation's business focus and product/service provisions online, securing a large scale/amount of business transactions, adjusting production outputs and inventory levels and having more registered users than competitors do. The top critical success measuring criteria for the buying function are as follows: securing the establishment of business relationships between businesses, displaying the measures ensuring mutual trust and cooperation online, ensuring employees' recognition of the benefit of e-commerce in increasing revenue, ensuring the contribution to the development and realisation of corporate strategy, achieving cost reduction for the organisation, making the purchase of famous brand products available/doable, securing a large scale/amount of business transactions, and ensuring the attainability of products/services at a lower price

    Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures

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    Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2) and with a mixture (30% CO2 and 70% N2) in dry and wet conditions at 25 ºC, 50 ºC, 60 ºC and 75 ºC and up to 600 kPa. Interesting values of single gas selectivity up to 60 ºC (between 31 and 28 for CO2/N2 and between 33 and 30 for CO2/CH4) in dry condition were obtained. The separation factor measured for the mixture was 20% lower compared to the single gas selectivity, in the whole temperature range analyzed. In saturation conditions the data showed that water influences the performance of the membranes, inducing a reduction of the permeance of all gases. Moreover, the presence of water caused a decrease of single gas selectivity and separation factor, although not so significant, highlighting the very high water resistance of hollow fiber membrane modules

    Human Genetics in Rheumatoid Arthritis Guides a High-Throughput Drug Screen of the CD40 Signaling Pathway

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    Although genetic and non-genetic studies in mouse and human implicate the CD40 pathway in rheumatoid arthritis (RA), there are no approved drugs that inhibit CD40 signaling for clinical care in RA or any other disease. Here, we sought to understand the biological consequences of a CD40 risk variant in RA discovered by a previous genome-wide association study (GWAS) and to perform a high-throughput drug screen for modulators of CD40 signaling based on human genetic findings. First, we fine-map the CD40 risk locus in 7,222 seropositive RA patients and 15,870 controls, together with deep sequencing of CD40 coding exons in 500 RA cases and 650 controls, to identify a single SNP that explains the entire signal of association (rs4810485, P = 1.4×10(−9)). Second, we demonstrate that subjects homozygous for the RA risk allele have ∼33% more CD40 on the surface of primary human CD19+ B lymphocytes than subjects homozygous for the non-risk allele (P = 10(−9)), a finding corroborated by expression quantitative trait loci (eQTL) analysis in peripheral blood mononuclear cells from 1,469 healthy control individuals. Third, we use retroviral shRNA infection to perturb the amount of CD40 on the surface of a human B lymphocyte cell line (BL2) and observe a direct correlation between amount of CD40 protein and phosphorylation of RelA (p65), a subunit of the NF-κB transcription factor. Finally, we develop a high-throughput NF-κB luciferase reporter assay in BL2 cells activated with trimerized CD40 ligand (tCD40L) and conduct an HTS of 1,982 chemical compounds and FDA–approved drugs. After a series of counter-screens and testing in primary human CD19+ B cells, we identify 2 novel chemical inhibitors not previously implicated in inflammation or CD40-mediated NF-κB signaling. Our study demonstrates proof-of-concept that human genetics can be used to guide the development of phenotype-based, high-throughput small-molecule screens to identify potential novel therapies in complex traits such as RA

    Genetics of rheumatoid arthritis contributes to biology and drug discovery

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    A major challenge in human genetics is to devise a systematic strategy to integrate disease-associated variants with diverse genomic and biological datasets to provide insight into disease pathogenesis and guide drug discovery for complex traits such as rheumatoid arthritis (RA)1. Here, we performed a genome-wide association study (GWAS) meta-analysis in a total of >100,000 subjects of European and Asian ancestries (29,880 RA cases and 73,758 controls), by evaluating ~10 million single nucleotide polymorphisms (SNPs). We discovered 42 novel RA risk loci at a genome-wide level of significance, bringing the total to 1012–4. We devised an in-silico pipeline using established bioinformatics methods based on functional annotation5, cis-acting expression quantitative trait loci (cis-eQTL)6, and pathway analyses7–9 – as well as novel methods based on genetic overlap with human primary immunodeficiency (PID), hematological cancer somatic mutations and knock-out mouse phenotypes – to identify 98 biological candidate genes at these 101 risk loci. We demonstrate that these genes are the targets of approved therapies for RA, and further suggest that drugs approved for other indications may be repurposed for the treatment of RA. Together, this comprehensive genetic study sheds light on fundamental genes, pathways and cell types that contribute to RA pathogenesis, and provides empirical evidence that the genetics of RA can provide important information for drug discovery

    GJB2 mutation spectrum in 2063 Chinese patients with nonsyndromic hearing impairment

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    Background: Mutations in GJB2 are the most common molecular defects responsible for autosomal recessive nonsyndromic hearing impairment (NSHI). The mutation spectra of this gene vary among different ethnic groups. Methods: In order to understand the spectrum and frequency of GJB2 mutations in the Chinese population, the coding region of the GJB2 gene from 2063 unrelated patients with NSHI was PCR amplified and sequenced. Results: A total of 23 pathogenic mutations were identified. Among them, five (p.W3X, c.99delT, c.155_c.158delTCTG, c.512_c.513insAACG, and p.Y152X) are novel. Three hundred and seven patients carry two confirmed pathogenic mutations, including 178 homozygotes and 129 compound heterozygotes. One hundred twenty five patients carry only one mutant allele. Thus, GJB2 mutations account for 17.9% of the mutant alleles in 2063 NSHI patients. Overall, 92.6% (684/739) of the pathogenic mutations are frame-shift truncation or nonsense mutations. The four prevalent mutations; c.235delC, c.299_c.300delAT, c.176_c.191del16, and c.35delG, account for 88.0% of all mutantalleles identified. The frequency of GJB2 mutations (alleles) varies from 4% to 30.4% among different regions of China. It also varies among different sub-ethnic groups. Conclusion: In some regions of China, testing of the three most common mutations can identify at least one GJB2 mutant allele in all patients. In other regions such as Tibet, the three most common mutations account for only 16% the GJB2 mutant alleles. Thus, in this region, sequencing of GJB2 would be recommended. In addition, the etiology of more than 80% of the mutant alleles for NSHI in China remains to be identified. Analysis of other NSHI related genes will be necessary

    Optimisation of hydrolysis conditions for antioxidant hydrolysate production from whey protein isolates using response surface methodology

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    peer-reviewedThe hydrolysates of whey protein isolates (WPI) by papain were found to possess antioxidant activity. Response surface methodology (RSM) was used to improve the antioxidant activity of these hydrolysates. The model was validated and shown to be statistically adequate and accurate in predicting the response. For both 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activity and reducing power responses, the optimised conditions were achieved at an enzyme to substrate ratio (E/S, w/w) of 2.22%, hydrolysis time of 3.60 h, and hydrolysis temperature of 45.70 °C. Under the optimised conditions, DPPH radical-scavenging activity of the hydrolysates of WPI was 31.48% and the reducing power was 0.612 at 700 nm. The results of confirmation experiments indicated that the model was powerful and suitable for estimation of the experimental value. The hydrolysate of WPI has potential application as an antioxidant in food products.National Science Technology Minister of Chin

    Cloning and analysis of microRNAs encoded by the primate γ-herpesvirus rhesus monkey rhadinovirus

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    Several pathogenic human herpesviruses have recently been shown to express virally encoded microRNAs in infected cells. Although the function of these microRNAs is largely unknown, they are hypothesized to play a role in mediating viral replication by downregulating cellular mRNAs encoding antiviral factors. Here, we report the cloning and analysis of microRNAs encoded by Rhesus Monkey Rhadinovirus (RRV), an animal virus model for the pathogenic human γ-herpesvirus Kaposi's Sarcoma-Associated Herpesvirus (KSHV). RRV expresses several microRNAs that are encoded in the same genomic location as the previously reported KSHV microRNAs, yet these microRNAs are unrelated in primary sequence. These data set the stage for the mutational ablation and phenotypic analysis of RRV mutants lacking one or more viral microRNAs
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