43 research outputs found

    First-generation structure-activity relationship studies of 2,3,4,9-tetrahydro-1H-carbazol-1-amines as CpxA phosphatase inhibitors

    Get PDF
    Genetic activation of the bacterial two-component signal transduction system, CpxRA, abolishes the virulence of a number of pathogens in human and murine infection models. Recently, 2,3,4,9-tetrahydro-1H-carbazol-1-amines were shown to activate the CpxRA system by inhibiting the phosphatase activity of CpxA. Herein we report the initial structure-activity relationships of this scaffold by focusing on three approaches 1) A-ring substitution, 2) B-ring deconstruction to provide N-arylated amino acid derivatives, and 3) C-ring elimination to give 2-ethylamino substituted indoles. These studies demonstrate that the A-ring is amenable to functionalization and provides a promising avenue for continued optimization of this chemotype. Further investigations revealed that the C-ring is not necessary for activity, although it likely provides conformational constraint that is beneficial to potency, and that the (R) stereochemistry is required at the primary amine. Simplification of the scaffold through deconstruction of the B-ring led to inactive compounds, highlighting the importance of the indole core. A new lead compound 26 was identified, which manifests a ∼30-fold improvement in CpxA phosphatase inhibition over the initial hit. Comparison of amino and des-amino derivatives in bacterial strains differing in membrane permeability and efflux capabilities demonstrate that the amine is required not only for target engagement but also for permeation and accumulation in Escherichia coli

    Metabolomic and metagenomic analysis of two crude oil production pipelines experiencing differential rates of corrosion

    Get PDF
    Corrosion processes in two North Sea oil production pipelines were studied by analyzing pig envelope samples via metagenomic and metabolomic techniques. Both production systems have similar physico-chemical properties and injection waters are treated with nitrate, but one pipeline experiences severe corrosion and the other does not. Early and late pigging material was collected to gain insight into the potential causes for differential corrosion rates. Metabolites were extracted and analyzed via ultra-high performance liquid chromatography/high-resolution mass spectrometry with electrospray ionization (ESI) in both positive and negative ion modes. Metabolites were analyzed by comparison with standards indicative of aerobic and anaerobic hydrocarbon metabolism and by comparison to predicted masses for KEGG metabolites. Microbial community structure was analyzed via 16S rRNA gene qPCR, sequencing of 16S PCR products, and MySeq Illumina shotgun sequencing of community DNA. Metagenomic data were used to reconstruct the full length 16S rRNA genes and genomes of dominant microorganisms. Sequence data were also interrogated via KEGG annotation and for the presence of genes related to terminal electron accepting (TEA) processes as well as aerobic and anaerobic hydrocarbon degradation. Significant and distinct differences were observed when comparing the ‘high corrosion’ (HC) and the ‘low corrosion’ (LC) pipeline systems, especially with respect to the TEA utilization potential. The HC samples were dominated by sulfate-reducing bacteria (SRB) and archaea known for their ability to utilize simple carbon substrates, whereas LC samples were dominated by pseudomonads with the genetic potential for denitrification and aerobic hydrocarbon degradation. The frequency of aerobic hydrocarbon degradation genes was low in the HC system, and anaerobic hydrocarbon degradation genes were not detected in either pipeline. This is in contrast with metabolite analysis, which demonstrated the presence of several succinic acids in HC samples that are diagnostic of anaerobic hydrocarbon metabolism. Identifiable aerobic metabolites were confined to the LC samples, consistent with the metagenomic data. Overall, these data suggest that corrosion management might benefit from a more refined understanding of microbial community resilience in the face of disturbances such as nitrate treatment or pigging, which frequently prove insufficient to alter community structure toward a stable, less-corrosive assemblage.This work was supported in part by grants from the University of Oklahoma Biocorrosion Center, the National Science Foundation (OCE 1634630 and MCB 1329890) and BP (The Gulf of Mexico Research Initiative, Project No. 130206). The instrumentation for the metabolomic analysis was funded by ONR through a DURIP grant (Award no. N000140910797), and the method development by ONR through a MURI grant (Award no. N000141010946).Ye

    Some recommendations for developing multidimensional computerized adaptive tests for patient-reported outcomes

    Get PDF
    PURPOSE: Multidimensional item response theory and computerized adaptive testing (CAT) are increasingly used in mental health, quality of life (QoL), and patient-reported outcome measurement. Although multidimensional assessment techniques hold promises, they are more challenging in their application than unidimensional ones. The authors comment on minimal standards when developing multidimensional CATs. METHODS: Prompted by pioneering papers published in QLR, the authors reflect on existing guidance and discussions from different psychometric communities, including guidelines developed for unidimensional CATs in the PROMIS project. RESULTS: The commentary focuses on two key topics: (1) the design, evaluation, and calibration of multidimensional item banks and (2) how to study the efficiency and precision of a multidimensional item bank. The authors suggest that the development of a carefully designed and calibrated item bank encompasses a construction phase and a psychometric phase. With respect to efficiency and precision, item banks should be large enough to provide adequate precision over the full range of the latent constructs. Therefore CAT performance should be studied as a function of the latent constructs and with reference to relevant benchmarks. Solutions are also suggested for simulation studies using real data, which often result in too optimistic evaluations of an item bank's efficiency and precision. DISCUSSION: Multidimensional CAT applications are promising but complex statistical assessment tools which necessitate detailed theoretical frameworks and methodological scrutiny when testing their appropriateness for practical applications. The authors advise researchers to evaluate item banks with a broad set of methods, describe their choices in detail, and substantiate their approach for validation

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

    Get PDF
    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    Blood coagulation and beyond: position paper from the fourth Maastricht consensus conference on thrombosis

    Get PDF
    The Fourth Maastricht Consensus Conference on Thrombosis included the following themes. Theme 1: The "coagulome" as a critical driver of cardiovascular disease. Blood coagulation proteins also play divergent roles in biology and pathophysiology, related to specific organs, including brain, heart, bone marrow, and kidney. Four investigators shared their views on these organ- specific topics. Theme 2: Novel mechanisms of thrombosis. Mechanisms linking factor XII to fibrin, including their structural and physical properties, contribute to thrombosis, which is also affected by variation in microbiome status. Virus infection-associated coagulopathies perturb the hemostatic balance resulting in thrombosis and/ or bleeding. Theme 3: How to limit bleeding risks: insights from translational studies. This theme included state-of- the- art methodology for exploring the contribution of genetic determinants of a bleeding diathesis; determination of polymorphisms in genes that control the rate of metabolism by the liver of P2Y12 inhibitors, to improve safety of antithrombotic therapy. Novel reversal agents for direct oral anticoagulants are discussed. Theme 4: Hemostasis in extracorporeal systems: the value and limitations of ex vivo models. Perfusion flow chamber and nanotechnology developments are developed for studying bleeding and thrombosis tendencies. Vascularized organoids are utilized for disease modeling and drug development studies. Strategies for tackling extracorporeal membrane oxygenation-associated coagulopathy are discussed. Theme 5: Clinical dilemmas in thrombosis and antithrombotic management. Plenary presentations addressed controversial areas, i. e., thrombophilia testing, thrombosis risk assessment in hemophilia, novel antiplatelet strategies, and clinically tested factor XI(a) inhibitors, both possibly with reduced bleeding risk. Finally, COVID- 19-associated coagulopathy is revisited.Nephrolog

    Pre-desert Tripolitania: a new archaeological and archaeometrical examination of red slip ware from the Ghirza excavations and the Libyan valleys survey

    No full text
    International audienceThe First Libyan Pottery Workshop, held in July 2014 in the Society for Libyan Studies archives at the University of Leices-ter, set out to review the pottery samples from the Ghirza excavations and the Libyan Valleys Survey. A new archaeological and archaeometrical (petrographical) examination of these sherds (some of them previously published by John W. Hayes and John Dore in 1984 and 1996) allowed us to better characterise the Red Slip ware production of the pre-desert region of Tripolitania between the end of the 2 nd and the 7 th century. a new archaeological and archaeometrical examination of red sliP ware from the ghirza excavations and the libyan valleys survey this short, preliminary study is based on a pottery workshop carried out in July 2014 at the University of Leicester, in collaboration with the Centre Camille Jullian (aix-en-Provence). 1 the aim of the project was to examine and scientifically analyse a selection of pottery sherds from the Society for Libyan Studies archives, to improve our understanding of trade routes and supply channels across the Libyan pre-desert and beyond. the Roman pottery studied here comes from Ghirza and the Libyan Valleys (fig. 1), and is dated between the 2 nd to 7 th century aD. Ghirza is a pre-desert settlement investigated in 1955-57. a selection of the pottery was published by J. W. Hayes. 2 the Libyan Valleys survey was carried out in 1979-89 and the pottery studied by J. n. Dore.

    Les Thermes du Levant \ue0 Leptis Magna : quatre contextes c\ue9ramiques des IIIe et IVe si\ue8cles

    No full text
    This paper represents the second preliminary report on the excavations conducted in the Eastern bath at Leptis Magna by the Mission archéologique française en Libye since 1994. In order to contribute to the ‘ seriation’ of the Roman pottery in Tripolitania (I), four pottery contexts dated to c. 250‑260, 290‑310, 350-360 and 400 are catalogued here and their chronology discussed (II). An integrated archaeological and archaeometrical study of this documentation provides a better definition of the main ceramic classes imported to (e. g. Sicilian and Eastern Mediterranean amphorae) or regionally produced (amphorae, Tripolitanian Red Slip Ware, Cooking Ware) (IV). Lastly, this survey let us learn new information on the economy of the 3rd and 4th century port city (IV) and on the general chronology of the excavated area (V).Cet article constitue le deuxième volet de la publication préliminaire des fouilles des Thermes du Levant à Leptis Magna menées par la Mission archéologique française en Libye depuis 1994. En vue de contribuer à l’établissement d’une échelle chronologique de la céramique romaine en Tripolitaine (I), quatre contextes céramiques datés respectivement des années 250-260, 290-310, 350-360 et 400 sont présentés en détail et leur chronologie discutée (II). L’étude conjointe, archéologique et archéométrique, de cette documentation permet de progresser dans la définition des principales classes de céramiques importées (amphores siciliennes et orientales) et produites régionalement (amphores, sigillées tripolitaines, céramiques culinaires) (III). Enfin, cette étude apporte quelques nouvelles données sur l’économie de la ville des IIIe et IVe s. (IV) et sur la chronologie générale du site (V).Bonifay Michel, Capelli Claudio, Franco Carmela, Leitch Victoria, Riccardi Laurent, Berni Millet Piero. Les Thermes du Levant à Leptis Magna : quatre contextes céramiques des IIIe et IVe siècles. In: Antiquités africaines, 49,2013. pp. 67-150

    Metabolomic and Metagenomic Analysis of Two Crude Oil Production Pipelines Experiencing Differential Rates of Corrosion

    No full text
    Corrosion processes in two North Sea oil production pipelines were studied by analyzing pig envelope samples via metagenomic and metabolomic techniques. Both production systems have similar physico-chemical properties and injection waters are treated with nitrate, but one pipeline experiences severe corrosion and the other does not. Early and late pigging material was collected to gain insight into the potential causes for differential corrosion rates. Metabolites were extracted and analyzed via ultra-high performance liquid chromatography/high-resolution mass spectrometry with electrospray ionization (ESI) in both positive and negative ion modes. Metabolites were analyzed by comparison with standards indicative of aerobic and anaerobic hydrocarbon metabolism and by comparison to predicted masses for KEGG metabolites. Microbial community structure was analyzed via 16S rRNA gene qPCR, sequencing of 16S PCR products, and MySeq Illumina shotgun sequencing of community DNA. Metagenomic data were used to reconstruct the full length 16S rRNA genes and genomes of dominant microorganisms. Sequence data were also interrogated via KEGG annotation and for the presence of genes related to terminal electron accepting (TEA) processes as well as aerobic and anaerobic hydrocarbon degradation. Significant and distinct differences were observed when comparing the 'high corrosion' (HC) and the 'low corrosion' (LC) pipeline systems, especially with respect to the TEA utilization potential. The HC samples were dominated by sulfate-reducing bacteria (SRB) and archaea known for their ability to utilize simple carbon substrates, whereas LC samples were dominated by pseudomonads with the genetic potential for denitrification and aerobic hydrocarbon degradation. The frequency of aerobic hydrocarbon degradation genes was low in the HC system, and anaerobic hydrocarbon degradation genes were not detected in either pipeline. This is in contrast with metabolite analysis, which demonstrated the presence of several succinic acids in HC samples that are diagnostic of anaerobic hydrocarbon metabolism. Identifiable aerobic metabolites were confined to the LC samples, consistent with the metagenomic data. Overall, these data suggest that corrosion management might benefit from a more refined understanding of microbial community resilience in the face of disturbances such as nitrate treatment or pigging, which frequently prove insufficient to alter community structure toward a stable, less-corrosive assemblage
    corecore