Protective Effect of Quercetin in LPS-Induced Murine Acute Lung Injury Mediated by cAMP-Epac Pathway.

Quercetin (Que) as an abundant flavonol element possesses potent antioxidative properties and has protective effect in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the specific mechanism is still unclear, so we investigated the effect of Que from in vivo and in vitro studies and the related mechanism of cAMP-PKA/Epac pathway. The results in mice suggested that Que can inhibit the release of inflammatory cytokine, block neutrophil recruitment, and decrease the albumin leakage in dose-dependent manners. At the same time, Que can increase the cAMP content of lung tissue, and Epac content, except PKA. The results in epithelial cell (MLE-12) suggested that Que also can inhibit the inflammatory mediators keratinocyte-derived chemokines release after LPS stimulation; Epac inhibitor ESI-09 functionally antagonizes the inhibitory effect of Que; meanwhile, PKA inhibitor H89 functionally enhances the inhibitory effect of Que. Overexpression of Epac1 in MLE-12 suggested that Epac1 enhance the effect of Que. All those results suggested that the protective effect of quercetin in ALI is involved in cAMP-Epac pathway.

An improvement of uncertainty in activity standardization with efficiency tracer technique.

The activities of ten pure beta emitters were measured with two tracer nuclei for each one by using efficiency tracing technique. The determination results of specific activity of 35S, 63Ni and 185W, using efficiency tracers 60Co and 134Cs, are presented. The uncertainties of the final results for the three beta emitting nuclides were 0.5% at 99.7% confidence. The relationship between beta spectra and efficiency for the five nuclides were calculated with Fermi theory. The effects of the beta spectra shapes, end-point energies and chemical form of the tracers on the beta emitter activity results have been re-investigated. The type B uncertainty introduced by the upper limit of the fitting region (corresponding to the beta low detection efficiency), the polynomial fitting power (60Co as tracer), the lower limit of the fitting region (corresponding to self-absorption) and the gamma gate setting (134Cs as tracer) were investigated.