Karen St George

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Elevated polyamine levels are characteristic of many types of neoplastic cells and tissues. We demonstrate that in transgenic mice overexpressing ornithine decarboxylase in skin, changes in tissue polyamine levels, particularly putrescine, control the development and maintenance of the neoplastic phenotype. A specific inhibitor of the transgene,(More)
The phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) activates protein kinase C (PKC) and produces an early stimulation of Na+ transport across frog skin. The ionic basis for this stimulation was studied with combined transepithelial and intracellular electrical measurements. In an initial series of experiments, TPA approximately doubled the(More)
Acute exposure (up to 4 h) of LLC-PK1 epithelial cell sheets to the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) causes a rapid decrease of transepithelial electrical resistance (TER) to less than 15% of initial value. As the TPA exposure period is continued by chronically passaging cells in the presence of TPA, TER begins to recover. By 6 weeks(More)
In previous experiments we have shown that acute (30 minutes) exposure to phorbol esters or other protein kinase C activators causes increased transepithelial permeability, specifically by the increased paracellular permeability through tight junctions. However, the role of protein kinase C activators in carcinogenesis is predicted upon a chronic exposure(More)
The mRNA differential display technique is a method for molecular survey and analysis of differential gene expression in eukaryotic cells and tissues. We have previously described the use of ABI Prism fluorescent technology to specifically amplify expressed sequence tags (ESTs) from several different biological paradigms. High throughput, fluorescent(More)
The identity of the genetic defect(s) in Swiss 3T3 TNR-2 and TNR-9 that confers nonresponsiveness to the proliferative effect of 12-0-tetradecanoylphorbol-13-acetate (TPA) is not known. In BALB/c 3T3 cells, loss (via mutation) of a specific membrane ion transport system, the furosemide-sensitive Na+K+Cl- cotransporter, is associated with decreased(More)
BACKGROUND It was reported recently that sequences corresponding to the human T-lymphotropic virus type I (HTLV-I) tax gene were detected in peripheral blood mononuclear cells from 8 to 11 percent of healthy blood donors without detectable antibodies to HTLV-I. A multicenter blind study was conducted to determine if these results could be independently(More)
The synthesis and structure-activity relationship of 1-(aryl)-3-(4-(amino)benzyl)urea transient receptor potential vanilloid 1 (TRPV1) antagonists are described. A variety of cyclic amine substituents are well tolerated at the 4-position of the benzyl group on compounds containing either an isoquinoline or indazole heterocyclic core. These compounds are(More)