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N Dupuis

Publications and source records attributed to N Dupuis.

15 recordsLinked to original sources
PubMed2005

Triplet superconducting pairing and density-wave instabilities in organic conductors.

Using a renormalization group approach, we determine the phase diagram of an extended quasi-one-dimensional electron gas model that includes interchain hopping, nesting deviations, and both intrachain and interchain repulsive interactions. We find a close proximity of spin-density- and charge-density-wave phases and singlet d-wave and triplet f-wave superconducting phases. There is a striking correspondence between our results and recent puzzling experimental findings in the Bechgaard salts, including the coexistence of spin-density-wave and charge-density-wave phases and the possibility of a triplet pairing in the superconducting phase.

Journal Article↗
PubMed1999

Plasmin converts factor X from coagulation zymogen to fibrinolysis cofactor.

Known anticoagulant pathways have been shown to exclusively inhibit blood coagulation cofactors and enzymes. In the current work, we first investigated the possibility of a novel anticoagulant mechanism that functions at the level of zymogen inactivation. Utilizing both clotting and chromogenic assays, the fibrinolysis protease plasmin was found to irreversibly inhibit the pivotal function of factor X (FX) in coagulation. This was due to cleavage at several sites, the location of which were altered by association of FX with procoagulant phospholipid (proPL). The final products were approximately 28 and approximately 47 kDa for proPL-bound and unbound FX, respectively, which did not have analogues when activated FX (FXa) was cleaved instead. We next investigated whether the FX derivatives could interact with the plasmin precursor plasminogen, and we found that plasmin exposed a binding site only on proPL-bound FX. The highest apparent affinity was for the 28-kDa fragment, which was identified as the light subunit disulfide linked to a small fragment of the heavy subunit (Met-296 to approximately Lys-330). After cleavage by plasmin, proPL-bound FX furthermore was observed to accelerate plasmin generation by tissue plasminogen activator. Thus, a feedback mechanism localized by proPL is suggested in which plasmin simultaneously inhibits FX clotting function and converts proPL-bound FX into a fibrinolysis cofactor. These data also provide the first evidence for an anticoagulant mechanism aimed directly at the zymogen FX.

Anticoagulants↗
PubMed1997

Schizophrenia: revisited.

Schizophrenia is a devastating illness for the affected individuals and their families. Health care providers and researchers are also challenged by the clinical heterogeneity of this disorder. The goal of the present paper is to offer an updated overview of the aetiology, definition, clinical manifestations and pharmacological and psychosocial treatments of schizophrenia. Finally, some future directions for psychiatric nursing will be suggested in light of the existing knowledge of schizophrenia.

Antipsychotic Agents↗
PubMed1983

Purification and identification of multiple forms of dynorphin in human placenta.

Immunoreactive dynorphin (ir-Dyn) and opiate-like peptides (OLP) were measured in acid (HC1) extracts of human placenta by the use of an antibody to synthetic Dyn-(1-13) and of the displacement of [3H]-naloxone binding to rat brain homogenates, respectively. The placenta contained 57.6 pmoles per g of ir-Dyn and 134.4 pmoles per g of naloxone binding equivalents. After passage of the extract through cartridges of Sep Pak C18, half of the OLP was eluted with ir-Dyn at 35% acetonitrile (ACN), the rest being eluted at 60% ACN. Both fractions obtained from Sep Pak were chromatographed separately on Sephadex G-50, the OLP of the 35% ACN fraction coeluting with the ir-Dyn speak and that of the 60% ACN fraction being eluted at the same volume as synthetic beta-endorphin. Conversely, the fraction of OLP coeluting with synthetic leucine-enkephalin (Leu-Enk) in these two chromatographies was minimal. The Dyn-immunoreactive material was further purified by high pressure liquid chromatography on reverse phase micro-Bondapak C18 columns to give three distinct peaks corresponding to synthetic Dyn-(1-11), Dyn-(1-13) and Dyn-(1-12), respectively. Our results indicate that the human placenta contains several forms of ir-Dyn which account for about half of its endogenous OLP.

Animals↗