138 research outputs found

    2'-O-(2-methoxyethyl) nucleosides are not phosphorylated or incorporated into the genome of Human Lymphoblastoid TK6 Cells

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    Nucleoside analogues with 2'-modified sugar moieties are often used to improve the RNA target affinity and nuclease resistance of therapeutic oligonucleotides in preclinical and clinical development. Despite their enhanced nuclease resistance, oligonucleotides could slowly degrade releasing nucleoside analogues that have the potential to become phosphorylated and incorporated into cellular DNA and RNA. For the first time, the phosphorylation and DNA and RNA incorporation of 2'-O-(2-methoxyethyl) (2'-O-MOE) nucleoside analogues have been investigated. Using LC/MS/MS, we showed that enzymes in the nucleotide salvage pathway including deoxycytidine kinase (dCK) and thymidine kinase (TK1) displayed poor reactivity toward 2'-O-MOE nucleoside analogues. On the other hand, 2'-fluoro (F) nucleosides, regardless of the nucleobase, were efficiently phosphorylated to their monophosphate forms by dCK and TK1. Consistent with their efficient phosphorylation by dCK and TK1, 2'-F nucleosides analogues were incorporated into cellular DNA and RNA while no incorporation was detected with 2'-O-MOE nucleoside analogues. In conclusion, these data suggest that the inability of dCK and TK1 to create the monophosphates of 2'-O-MOE nucleoside analogues reduces the risk of their incorporation into cellular DNA and RNA

    National and firm-level drivers of the devolution of HRM decision making to line managers

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    Multinational companies must understand the influences on responsibility for managing people so that they can manage talent consistently thus ensuring that it is transferable across locations. We examine the impact of firm and national level characteristics on the devolution of HRM decision making to line managers. Our analysis draws on data from 2335 indigenous organizations in 21 countries. At the firm level, we found that where the HR function has higher power, devolution is less likely. At the national level, devolution of decision making to line management is more likely in societies with more stringent employment laws and lower power distance

    Comparative genomics of isolates of a pseudomonas aeruginosa epidemic strain associated with chronic lung infections of cystic fibrosis patients

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    Pseudomonas aeruginosa is the main cause of fatal chronic lung infections among individuals suffering from cystic fibrosis (CF). During the past 15 years, particularly aggressive strains transmitted among CF patients have been identified, initially in Europe and more recently in Canada. The aim of this study was to generate high-quality genome sequences for 7 isolates of the Liverpool epidemic strain (LES) from the United Kingdom and Canada representing different virulence characteristics in order to: (1) associate comparative genomics results with virulence factor variability and (2) identify genomic and/or phenotypic divergence between the two geographical locations. We performed phenotypic characterization of pyoverdine, pyocyanin, motility, biofilm formation, and proteolytic activity. We also assessed the degree of virulence using the Dictyostelium discoideum amoeba model. Comparative genomics analysis revealed at least one large deletion (40-50 kb) in 6 out of the 7 isolates compared to the reference genome of LESB58. These deletions correspond to prophages, which are known to increase the competitiveness of LESB58 in chronic lung infection. We also identified 308 non-synonymous polymorphisms, of which 28 were associated with virulence determinants and 52 with regulatory proteins. At the phenotypic level, isolates showed extensive variability in production of pyocyanin, pyoverdine, proteases and biofilm as well as in swimming motility, while being predominantly avirulent in the amoeba model. Isolates from the two continents were phylogenetically and phenotypically undistinguishable. Most regulatory mutations were isolate-specific and 29% of them were predicted to have high functional impact. Therefore, polymorphism in regulatory genes is likely to be an important basis for phenotypic diversity among LES isolates, which in turn might contribute to this strain's adaptability to varying conditions in the CF lung

    Metabolic phenotype-microRNA data fusion analysis of the systemic consequences of Roux-en-Y gastric bypass surgery.

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    BACKGROUND/OBJECTIVES: Bariatric surgery offers sustained marked weight loss and often remission of type 2 diabetes, yet the mechanisms of establishment of these health benefits are not clear. SUBJECTS/METHODS: We mapped the coordinated systemic responses of gut hormones, the circulating miRNAome and the metabolome in a rat model of Roux-en-Y gastric bypass (RYGB) surgery. RESULTS: The response of circulating microRNAs (miRNAs) to RYGB was striking and selective. Analysis of 14 significantly altered circulating miRNAs within a pathway context was suggestive of modulation of signaling pathways including G protein signaling, neurodegeneration, inflammation, and growth and apoptosis responses. Concomitant alterations in the metabolome indicated increased glucose transport, accelerated glycolysis and inhibited gluconeogenesis in the liver. Of particular significance, we show significantly decreased circulating miRNA-122 levels and a more modest decline in hepatic levels, following surgery. In mechanistic studies, manipulation of miRNA-122 levels in a cell model induced changes in the activity of key enzymes involved in hepatic energy metabolism, glucose transport, glycolysis, tricarboxylic acid cycle, pentose phosphate shunt, fatty-acid oxidation and gluconeogenesis, consistent with the findings of the in vivo surgery-mediated responses, indicating the powerful homeostatic activity of the miRNAs. CONCLUSIONS: The close association between energy metabolism, neuronal signaling and gut microbial metabolites derived from the circulating miRNA, plasma, urine and liver metabolite and gut hormone correlations further supports an enhanced gut-brain signaling, which we suggest is hormonally mediated by both traditional gut hormones and miRNAs. This transomic approach to map the crosstalk between the circulating miRNAome and metabolome offers opportunities to understand complex systems biology within a disease and interventional treatment setting

    Pooled safety analysis of baricitinib in adult patients with atopic dermatitis from 8 randomized clinical trials

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    BACKGROUND: Janus kinase (JAK) inhibition is a new mode of action in atopic dermatitis (AD); clarity about drug class safety considerations in the context of AD is important. Baricitinib, an oral, reversible, selective inhibitor of JAK1/JAK2, is in late-stage development for adult patients with moderate-to-severe AD. OBJECTIVE: To report pooled safety data for baricitinib in patients with moderate-to-severe AD in the clinical development program including long-term extension (LTE) studies. METHODS: This analysis included patient-level safety data from six double-blinded, randomized, placebo-controlled studies (one phase 2 and five phase 3), one double-blinded, randomized, LTE study and one open-label LTE study, reported in three data sets: placebo-controlled, 2-mg - 4-mg extended and All-bari AD. Safety outcomes include treatment-emergent adverse events, adverse events of special interest and abnormal laboratory changes. Proportions of patients with events and incidence rates were calculated. RESULTS: Data were collected for 2531 patients who were given baricitinib for 2247 patient-years (median duration 310 days). The frequency of serious infections, opportunistic infections and conjunctival disorders was low and similar between treatment groups in the placebo-controlled period. The most common serious infections were eczema herpeticum [n = 11, incidence rates (IR) = 0.5], cellulitis (n = 6, IR = 0.3) and pneumonia (n = 3, IR = 0.1). There were four opportunistic infections (IR = 0.2). No malignancies, gastrointestinal perforations, positively adjudicated cardiovascular events or tuberculosis were reported in the placebo-controlled period in baricitinib-treated patients. Frequency of herpes simplex was higher in the 4-mg group (6.1%) vs. the 2-mg (3.6%) and placebo group (2.7%); IRs in the extended data set (2-mg IR = 9.6; 4-mg IR = 14.5) were lower vs. the placebo-controlled data set (2-mg IR = 12.4; 4-mg IR = 21.3). In the All-bari AD data set, there were two positively adjudicated major adverse cardiovascular events (2-mg group): two venous thrombosis events (4-mg group) and one death. CONCLUSION: This integrated safety analysis in patients with moderate-to-severe AD confirms the established safety profile of baricitinib

    Phenotypic and Genome-Wide Analysis of an Antibiotic-Resistant Small Colony Variant (SCV) of Pseudomonas aeruginosa

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    Small colony variants (SCVs) are slow-growing bacteria, which often show increased resistance to antibiotics and cause latent or recurrent infections. It is therefore important to understand the mechanisms at the basis of this phenotypic switch.One SCV (termed PAO-SCV) was isolated, showing high resistance to gentamicin and to the cephalosporine cefotaxime. PAO-SCV was prone to reversion as evidenced by emergence of large colonies with a frequency of 10(-5) on media without antibiotics while it was stably maintained in presence of gentamicin. PAO-SCV showed a delayed growth, defective motility, and strongly reduced levels of the quorum sensing Pseudomonas quinolone signal (PQS). Whole genome expression analysis further suggested a multi-layered antibiotic resistance mechanism, including simultaneous over-expression of two drug efflux pumps (MexAB-OprM, MexXY-OprM), the LPS modification operon arnBCADTEF, and the PhoP-PhoQ two-component system. Conversely, the genes for the synthesis of PQS were strongly down-regulated in PAO-SCV. Finally, genomic analysis revealed the presence of mutations in phoP and phoQ genes as well as in the mexZ gene encoding a repressor of the mexXY and mexAB-oprM genes. Only one mutation occurred only in REV, at nucleotide 1020 of the tufA gene, a paralog of tufB, both encoding the elongation factor Tu, causing a change of the rarely used aspartic acid codon GAU to the more common GAC, possibly causing an increase of tufA mRNA translation. High expression of phoP and phoQ was confirmed for the SCV variant while the revertant showed expression levels reduced to wild-type levels.By combining data coming from phenotypic, gene expression and proteome analysis, we could demonstrate that resistance to aminoglycosides in one SCV mutant is multifactorial including overexpression of efflux mechanisms, LPS modification and is accompanied by a drastic down-regulation of the Pseudomonas quinolone signal quorum sensing system
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