LYSOPHOSPHATIDIC ACID PRODUCTION AND SIGNALING IN PLATELETS

Lysophosphatidic acid (LPA) belongs to a class of extracellular lipid signaling molecules. In the vasculature, LPA may regulate platelet activation and modulate endothelial and smooth muscle cell function. LPA has therefore been proposed as a mediator of cardiovascular disease. The bulk of circulating LPA is produced from plasma lysophosphatidylcholine (LPC) by autotaxin (ATX), a secreted lysophospholipase D (lysoPLD). Early studies suggest that some of the production of circulating LPA is platelet-dependent. ATX possesses an N-terminal somatomedin B-like domain suggesting the hypothesis that ATX interacts with platelet integrins which may localize ATX to substrate in the membrane and/or alter the catalytic activity of ATX. Using static adhesion and soluble binding assays we found that ATX does indeed bind to platelets and cultured mammalian cells in an integrin-dependent manner which is blocked by integrin function-blocking peptides and antibodies. This binding increases both the activity of ATX and localization of its product, LPA, to the platelet/cell membrane. LPA is generally stimulatory to human platelets although platelets from a small population of donors are refractory to LPA stimulation. Likewise LPA is inhibitory to murine platelets. We previously found that LPA receptor pan-antagonists reduce agonist-induced platelet activation, and partial stimulation of LPA5 specifically increases platelet activation in humans. Since both LPA5 and LPA4 are present at significant levels in human platelets, we hypothesized that LPA4 is responsible for an inhibitory pathway and LPA5 is responsible for an inhibitory pathway. We used mice deficient in LPA4 to test this model. Isolated platelet function tests revealed no major difference between lpa4-/- mice compared with WT mice although lpa4-/- mice were more prone to FeCl3-induced thrombosis. Paradoxically, chimeric mice reconstituted with lpa4-/- deficient bone marrow derived cells were protected from thrombosis. These discrepancies may be explained by involvement of endothelial cells and the relative scarcity of LPA receptors in murine platelets compared with human platelets. Taken together, these results demonstrate two critical regulators of LPA signaling and open up new avenues to further our understanding of atherothrombosis

Synthetic Routes to a Library of Novel Methionine Synthase Inhibitors

Fungal infections are of continuous concern, especially with regard to immunocompromised patients. In an effort to develop new potential anti-fungal agents, we have begun synthesizing a library of potential inhibitors of the fungal Methionine Synthase (MetSyn) enzyme. Key differences between the B12-independant fungal MetSyn enzyme and the B12-dependant mammalian form can allow for an antifungal drug to be developed to exclusively bind the fungal enzyme and inhibit fungal growth while leaving the host (patient) unaffected. We are currently exploring the synthesis of various pterin and deazaguanine-based molecules as these mimic folate, an essential substrate for MetSyn function. We have begun testing these new molecules for activity in a fungal growth assay, as well as a fluorescent assay for monitoring MetSyn activity

The Romantic Conventions of the "Haunted Melodrama"

THE ROMANTIC CONVENTIONS OF THE "HAUNTED MELODRAMA" THE NEXUS between love and death has been fodder for artists at least since antiquity. In Greek mythology, Orpheus famously descended into Hades in a fruitless attempt to retrieve his wife Eurydice from death. In his Divine Comedy, Dante Alighieri, after passing through hell and purgatory, is guided through paradise by his beloved Beatrice. The human preoccupation with the twin forces of love and death was best (and most frequently) expressed, however, by the artists of the Romantic movement. In more recent history, artists and directors working in the field of cinema resurrected many Romantic conventions in treating the same subject matter. Their collective work can be roughly collected into a film genre known as "haunted melodrama."(1) Before exploring the application of Romantic conventions to haunted melodramas, it is first necessary to establish the philosophical foundation of these Romantic conventions. In..

METHOD AND SYSTEM FOR IMPLEMENTING A MOBILE APPLICATION INTERFACE

The present disclosure includes methods, systems and computer program products for implementing a mobile application interface. Particularly, the present disclosure provides a method comprises receiving an input regarding a request to carry out an operation of a mobile payment application; determining data associated with an account identifier of an account of a user associated with the request to carry out the operation of the mobile payment application; and providing a user interface including the data associated with the account identifier to display via the mobile payment application

The \u3cem\u3edapE\u3c/em\u3e-encoded \u3cem\u3eN\u3c/em\u3e-succinyl-l,l-diaminopimelic Acid Desuccinylase from \u3cem\u3eHaemophilus influenzae\u3c/em\u3e Contains Two Active-site Histidine Residues

The catalytic and structural properties of the H67A and H349A dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae were investigated. On the basis of sequence alignment with the carboxypeptidase from Pseudomonas sp. strain RS-16, both H67 and H349 were predicted to be Zn(II) ligands. The H67A DapE enzyme exhibited a decreased catalytic efficiency (180-fold) compared with wild-type (WT) DapE towards N-succinyldiaminopimelic acid. No catalytic activity was observed for H349A under the experimental conditions used. The electronic paramagnetic resonance (EPR) and electronic absorption data indicate that the Co(II) ion bound to H349A-DapE is analogous to that of WT DapE after the addition of a single Co(II) ion. The addition of 1 equiv of Co(II) to H67A DapE provides spectra that are very different from those of the first Co(II) binding site of the WT enzyme, but that are similar to those of the second binding site. The EPR and electronic absorption data, in conjunction with the kinetic data, are consistent with the assignment of H67 and H349 as active-site metal ligands for the DapE from H. influenzae. Furthermore, the data suggest that H67 is a ligand in the first metal binding site, while H349 resides in the second metal binding site. A three-dimensional homology structure of the DapE from H. influenzae was generated using the X-ray crystal structure of the DapE from Neisseria meningitidis as a template and superimposed on the structure of the aminopeptidase from Aeromonas proteolytica (AAP). This homology structure confirms the assignment of H67 and H349 as active-site ligands. The superimposition of the homology model of DapE with the dizinc(II) structure of AAP indicates that within 4.0 Å of the Zn(II) binding sites of AAP all of the amino acid residues of DapE are nearly identical

Making virtue reign : citizenship and civic education in the political philosophy of Jean-Jacques Rousseau

This dissertation is a study of Jean-Jacques Rousseau’s conceptions of citizenship and civic education. Its basic conceit is that the former—what it means to be a citizen—can be understood fully only in light of the latter—what it means to become a citizen. It argues that Rousseau’s conception of civic education—a denaturing, psychically transformative process whereby human beings become citizens who virtuously exercise their rights and fulfill their duties under the social contract—poses a critical, yet, in a way, friendly, challenge to us as liberal democrats. For as radically as Rousseauian civic education differs from ours, it is grounded in premises that we, as liberal democrats, affirm, i.e., that human beings are naturally free and equal and therefore that the only authority to which human beings may be legitimately subject is that to which they consent. Hence, our own premises compel us to confront the challenge posed by Rousseau’s writings on citizenship and civic education. Contemporary disillusionment with citizenship across the liberal-democratic West makes doing this only more urgent and potentially illuminating and fruitful. Consisting in careful textual analysis of the various works and passages in which Rousseau treats civic education, the dissertation is organized around a heretofore insufficiently examined distinction between a preliminary stage of civic education and civic education proper. Whereas, in the former, future citizens are persuaded by legislators effectively to enact wise laws by means of ingenious yet disingenuous appeals to divine authority, in the latter, dutifulness to such authority is replaced as the moral basis for civic virtue with patriotism. The thesis of the dissertation is that, in order to understand the limits and possibilities of Rousseauian citizenship, it is necessary to understand this shift that lies at the heart of Rousseauian civic education.Governmen

Substrate Scope Analysis of Biocatalytic Halogenation on Complex Substrates

Malbrancheamide is a fungal natural product with significant vasorelaxation effects and potential as a cardiovascular therapeutic. The dichlorination of the indole ring is key for its biological activity, and this transformation is performed by the flavin dependent halogenase MalA. This enzyme utilizes a proposed chloramine lysine intermediate to iteratively and selectively chlorinate its natural substrate premalbrancheamide. Halogenases can provide orthogonal selectivity to many chemical methods, making them useful for pharmaceutical applications, while providing selective methods for late-stage functionalization. This investigation focuses on the substrate scope of the halogenase on complex pharmaceutically relevant substrates in collaboration with the Novartis Institutes for Biomedical Research. The bromination and chlorination reaction conditions were optimized, and the products were structurally characterized by NMR spectroscopy to gain further understanding of the versatility of the wild type enzyme and its mutants

Substrate Scope Analysis of Biocatalytic Halogenation on Complex Substrates

Malbrancheamide is a fungal natural product with significant vasorelaxation effects and potential as a cardiovascular therapeutic. The dichlorination of the indole ring is key for its biological activity, and this transformation is performed by the flavin dependent halogenase MalA. This enzyme utilizes a proposed chloramine lysine intermediate to iteratively and selectively chlorinate its natural substrate premalbrancheamide. Halogenases can provide orthogonal selectivity to many chemical methods, making them useful for pharmaceutical applications, while providing selective methods for late-stage functionalization. This investigation focuses on the substrate scope of the halogenase on complex pharmaceutically relevant substrates in collaboration with the Novartis Institutes for Biomedical Research. The bromination and chlorination reaction conditions were optimized, and the products were structurally characterized by NMR spectroscopy to gain further understanding of the versatility of the wild type enzyme and its mutants

Modeling Heterogeneous Traffic with Cooperative Adaptive Cruise Control Vehicles: A Macroscopic Equilibrium Approach

This thesis proposes a modeling framework to characterize equilibrium traffic flow relations for heterogeneous traffic composed of both standard and Cooperative Adaptive Cruise Control (CACC) vehicles, capturing the impact of CACC market penetration and vehicle arrangement within a lane. The resulting parameterized fundamental diagram is then integrated with the first-order macroscopic traffic model, creating the ability to characterize operational performance on a network for heterogeneous traffic with varying CACC market penetration. This first-order approach is demonstrated through an illustrative case study which considers a small network with time-varying demand, temporary capacity reductions, and CACC market penetration ranging from 0.0 to 1.0. The results indicate that maximum throughput initially decreases as CACC traffic is introduced, but eventually improves significantly for CACC market penetration rates above 0.4. Additionally, they show that when an incident abruptly reduces road capacity, introducing even a small fraction of CACC vehicles reduces the speed at which the congestion wavefront propagates upstream