Lee Ann Sporn

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von Willebrand factor (vWf) secreted constitutively by human endothelial cells was compared to that released from Weibel-Palade bodies after stimulation. The majority of constitutively secreted molecules were dimeric and contained both pro-vWf and mature subunits. In contrast, the vWf released by the calcium ionophore A23187 or thrombin consisted of only(More)
The lung epithelium has recently been identified as a novel site of fibrinogen (FBG) biosynthesis. A coordinated upregulation of A alpha, B beta, and gamma chain FBG gene transcription occurs upon stimulation of A549 lung epithelial cells with dexamethasone (DEX) and the proinflammatory mediator interleukin-6 (IL-6). Subsequently, the cells synthesize and(More)
von Willebrand factor (vWf) is secreted from endothelial cells by one of two pathways-a constitutive pathway and a regulated pathway originating from the Weibel-Palade bodies. The molecular form of vWf from each of these pathways differs, with the most biologically potent molecules being released from Weibel-Palade bodies (Loesberg, C., M. D. Gonsalves, J.(More)
Immunofluorescence staining of buffy coat smears from a patient with chronic myelogenous leukemia in accelerated phase showed that approximately 13% of all nucleated cells contained von Willebrand protein and, therefore, appeared to be of megakaryocytic origin. This was confirmed by positive staining with antisera against platelet factor 4 and platelet(More)
Cultured endothelial cells from the human umbilical vein were incubated with low concentrations (1 microgram/ml) of the photosensitizer Photofrin II. Following a sublethal light exposure, a light dose-dependent release of von Willebrand factor (vWf) into the culture medium was observed. Analysis of the multimeric composition of the released protein(More)
Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever, is an obligate intracellular bacterial organism that infects primarily the vascular endothelial cells (EC). A component of the EC response to infection is transcriptional activation, which may contribute to the thrombotic and inflammatory consequences of disease. In this study, we(More)
Adhesion and spreading of cultured human umbilical vein endothelial cells on fibrin surfaces of varying structure were characterized to understand better the interactions occurring between endothelium and fibrin at sites of vascular injury. Fibrin prepared with reptilase, which cleaves only fibrinopeptide A from fibrinogen, and fibrin prepared with(More)
Human umbilical vein endothelial cells in tissue culture were irradiated with doses between 0 and 40 Gy, and the released von Willebrand (vW) protein and that which remained associated with the cells was quantitated. Doses of 20 Gy and higher produced a statistically significant increase in amount of vW protein secreted. This release was present whether the(More)
Endothelial cells were cultured from human umbilical veins and incubated with Photofrin (1 microgram/ml). Cells were then exposed to light, and cytoplasmic microtubule (MT) status was monitored by immunofluorescence microscopy using alpha-tubulin antibody. As early as 15 min following irradiation, a light dose-dependent depolymerization of MT was observed.(More)
Our laboratory has reported on a biphasic pattern of nuclear factor kappaB (NF-kappaB) activation in cultured human umbilical vein endothelial cells during infection with Rickettsia rickettsii, an obligate, intracellular bacterium, and the etiologic agent of Rocky Mountain spotted fever. Transcriptional activation of the tissue factor (TF) gene during this(More)