Laura L Hughes

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The development of a reliable assay for human synovial fluid phospholipase A2 (HSF PLA2) is important for the kinetic characterization of the enzyme and for the identification of enzyme inhibitors. This enzyme behaves differently from other extracellular PLA2s in many standard phospholipase assays and is generally assayed using radiolabeled, autoclaved(More)
Seventy patients with squamous cell carcinoma or cloacogenic carcinoma of the anus treated from 1979-1987 were reviewed. Five groups were analyzed: (a) local excision (LE) with postoperative radiotherapy (n = 9); (b) abdominoperineal resection (APR) with either pre- or postoperative radiotherapy (n = 22); (c) definitive radiotherapy alone (n = 8); (d)(More)
Human cytosolic phospholipase A2 (cPLA2) is an 85-kDa protein which displays a preference for arachidonoyl phospholipids as substrates. This substrate preference and the assay characteristics of the enzyme are quite different from those of the smaller, more well-studied extracellular PLA2s. We now report the development of a nonradioactive,(More)
The active site of thioredoxin-1 (Trx1) is oxidized in cells with increased reactive oxygen species (ROS) and is reduced by thioredoxin reductase-1 (TrxR1). The purpose of the present study was to determine the extent to which the redox state of Trx1 is sensitive to changes in these opposing reactions. Trx1 redox state and ROS generation were measured in(More)
Human cytosolic phospholipase A2 (cPLA2) is an arachidonic acid specific enzyme which may play a role in arachidonic acid release, eicosanoid production, and signal transduction. The PLA2 activity of this enzyme is stimulated by microM levels of Ca2+. Using a pure recombinant enzyme, we have confirmed that cPLA2 is not absolutely dependent on Ca2+, since(More)
Although 5-fluorouracil (5-FU) is commonly used in conjunction with radiotherapy to treat gastrointestinal malignancies, the molecular mechanisms underlying the clinically observed therapeutic advantage of this combination of agents have not been clearly established. The present in vitro studies addressed the possibility that the radiosensitization of(More)
The extracellular phospholipase A2s (PLA2) from cobra venom, rattlesnake venom, and porcine pancreas were analyzed by radiation inactivation to determine their functional aggregation states. The analysis was performed in the presence of the protein transferrin at two different concentrations of PLA2: 5 micrograms/ml. The small size of these proteins(More)
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