Rayleigh and Hyper-Rayleigh scatterings(HRS) from the nano-particle SnO2 were measured. It is found that as the concentration of the colloidal SnO2 or radiation power increases, the first- and second-order polarizabil...Rayleigh and Hyper-Rayleigh scatterings(HRS) from the nano-particle SnO2 were measured. It is found that as the concentration of the colloidal SnO2 or radiation power increases, the first- and second-order polarizabilities decrease. The radiation power dependencies of the first- and second-order polarizabilities show two domains: in high radiation power domain, the first- and second-order polarizabilities are approximately constant, in low radiation power domain, the first- and second-order polarizabilities increase sharply and become sensitive to the radiation power. The behavior of the concentration dependencies of the first- and second-order polarizabilities of colloidal SnO2 particles is similar to that of the radiation power dependence. A detailed mechanism explaining these phenomena has been discussed.展开更多
OBJECTIVE Steroid-resistant airway hyper-responsiveness(AHR)has been proposed to be related to the activation of innate host defense pathways such as those induced by LPS,IFN-γ,and LPS/IFN-γ-stimulated essential med...OBJECTIVE Steroid-resistant airway hyper-responsiveness(AHR)has been proposed to be related to the activation of innate host defense pathways such as those induced by LPS,IFN-γ,and LPS/IFN-γ-stimulated essential mediator IL-27.We investigated whether andrographolide,apreviously demonstrated anti-inflammatory bioactive molecule extracted from the plant Andrographis paniculata,could restore steroid sensitivity to block LPS/IFN-γ-induced IL-27 production and AHR viaits anti-oxidative property.METHODS Mouse macrophage cell line Raw264.7,mouse primary pulmonary monocyte/macrophage,and BALB/c mouse were treated with LPS/IFN-γ,in the presence and absence of increasing doses of dexamethasone and/or andrographolide.mRNA and protein levels of IL-27 in vitro and in vivo were examined,and mouse AHR was assessed.RESULTS Dexamethasone alone failed to inhibit LPS/IFN-γ-induced IL-27 and AHR in mice.Andrographolide significantly facilitated the suppressive effect of dexamethasone on LPS/IFN-γ-induced IL-27 level in macrophage cell line and primary monocyte/macrophage,mouse bronchoalveolar lavage fluid and lung tissue,and furthermore on the incurring AHR.LPS/IFN-γdid not impede nuclear translocation of glucocorticoid receptors but diminishthe protein level of histone deacetylase-2(HDAC2),an essential epigenetic enzymeresponsible for steroid anti-inflammatory action.Andrographolide at low doses(5μmol·L-1 in vitro;1mg·kg-1,ip in vivo)restored nuclear HDAC2 protein levels both in cells and in mouse lungs,possibly via suppression of PI3K/Akt signaling pathway and up-regulation of the anti-oxidative transcription factor Nrf-2level.CONCLUSION Our data suggest that andrographolide may resensitize steroid action on blocking LPS/IFN-γ-induced IL-27 and resultant AHR by restoring HDAC2 level.展开更多
文摘Rayleigh and Hyper-Rayleigh scatterings(HRS) from the nano-particle SnO2 were measured. It is found that as the concentration of the colloidal SnO2 or radiation power increases, the first- and second-order polarizabilities decrease. The radiation power dependencies of the first- and second-order polarizabilities show two domains: in high radiation power domain, the first- and second-order polarizabilities are approximately constant, in low radiation power domain, the first- and second-order polarizabilities increase sharply and become sensitive to the radiation power. The behavior of the concentration dependencies of the first- and second-order polarizabilities of colloidal SnO2 particles is similar to that of the radiation power dependence. A detailed mechanism explaining these phenomena has been discussed.
基金The project supported by National Medical Research Council of Singapore(NMRC/CBRG/0027/2012)
文摘OBJECTIVE Steroid-resistant airway hyper-responsiveness(AHR)has been proposed to be related to the activation of innate host defense pathways such as those induced by LPS,IFN-γ,and LPS/IFN-γ-stimulated essential mediator IL-27.We investigated whether andrographolide,apreviously demonstrated anti-inflammatory bioactive molecule extracted from the plant Andrographis paniculata,could restore steroid sensitivity to block LPS/IFN-γ-induced IL-27 production and AHR viaits anti-oxidative property.METHODS Mouse macrophage cell line Raw264.7,mouse primary pulmonary monocyte/macrophage,and BALB/c mouse were treated with LPS/IFN-γ,in the presence and absence of increasing doses of dexamethasone and/or andrographolide.mRNA and protein levels of IL-27 in vitro and in vivo were examined,and mouse AHR was assessed.RESULTS Dexamethasone alone failed to inhibit LPS/IFN-γ-induced IL-27 and AHR in mice.Andrographolide significantly facilitated the suppressive effect of dexamethasone on LPS/IFN-γ-induced IL-27 level in macrophage cell line and primary monocyte/macrophage,mouse bronchoalveolar lavage fluid and lung tissue,and furthermore on the incurring AHR.LPS/IFN-γdid not impede nuclear translocation of glucocorticoid receptors but diminishthe protein level of histone deacetylase-2(HDAC2),an essential epigenetic enzymeresponsible for steroid anti-inflammatory action.Andrographolide at low doses(5μmol·L-1 in vitro;1mg·kg-1,ip in vivo)restored nuclear HDAC2 protein levels both in cells and in mouse lungs,possibly via suppression of PI3K/Akt signaling pathway and up-regulation of the anti-oxidative transcription factor Nrf-2level.CONCLUSION Our data suggest that andrographolide may resensitize steroid action on blocking LPS/IFN-γ-induced IL-27 and resultant AHR by restoring HDAC2 level.
