Maintaining Microclimates during Nanoliter Chemical Dispensations Using Custom-Designed Source Plate Lids.

A method is described for using custom snap-on lids to protect chemicals in microtiter plates from evaporation and contamination. The lids contain apertures (diameter 1.5, 1.

Crosstalk between NF-kappaB and beta-catenin pathways in bacterial-colonized intestinal epithelial cells.

Salmonella-epithelial cell interactions are known to activate the proinflammatory NF-kappaB signaling pathway and have recently been found to also influence the beta-catenin signaling pathway, an important regulator of epithelial cell proliferation and differentiation. Here, using polarized epithelial cell models, we demonstrate that these same bacteria-mediated effects also direct the molecular crosstalk between the NF-kappaB and beta-catenin signaling pathways. Convergence of these two pathways is a result of the direct interaction between the NF-kappaB p50 subunit and beta-catenin.

Bacterial activation of beta-catenin signaling in human epithelia.

The mucosal lining of the human intestine is constantly bathed in a milieu of commensal gut flora, the vast majority of these being nonpathogenic microorganisms. Here, we demonstrate that microbial-epithelial cell interactions not only affect proinflammatory pathways but also influence beta-catenin signaling, a key component in regulating epithelial cell proliferation. The nonpathogenic Salmonella strain PhoP(c) activates the beta-catenin signaling pathway of human epithelia via a blockade of beta-catenin degradation.

Laminar flow induction of antioxidant response element-mediated genes in endothelial cells. A novel anti-inflammatory mechanism.

Atherosclerotic lesions preferentially develop in areas of the vasculature exposed to nonlaminar blood flow and low fluid shear stress, whereas laminar flow and high fluid shear stress are athero-protective. We have identified a set of genes including NAD(P)H:quinone oxidoreductase-1 (NQO1), heme oxygenase-1 (HO-1), ferritin (heavy and light chains), microsomal epoxide hydrolase, glutathione S-transferase, and gamma-glutamylcysteine synthase, whose expression is induced by exposure to prolonged physiological levels of steady laminar flow (shear stress = 20 dyn/cm(2)) in endothelial cells (EC). These genes contain an antioxidant response element (ARE) or ARE-like transcriptional regulatory sequence in their promoters and generally function to protect cells against oxidant stress.