Objective: To investigate the effect of arsenic trioxide(As_2O_3)with three different concentration groups on the distribution and recruitment of dendritic cells(DCs)in the conducting airways of asthmatic mice. Metho...Objective: To investigate the effect of arsenic trioxide(As_2O_3)with three different concentration groups on the distribution and recruitment of dendritic cells(DCs)in the conducting airways of asthmatic mice. Methods: Fifty BALB/c mice were divided into 5 groups at random:control group,asthmatic group,therapeutic groups with low dose(1 mg/kg),moderate dose(5 mg/kg)and high dose(10 mg/kg)of As_2O_3.The immunohistochemistry,scanning electron microscope and computerized image analysis were applied to detect airway DCs,respectively. Results: We demonstrated from the control mice that all intraepithelial NLDC-145 + DCs throughout the respiratory tree could be accounted for a network of cells with dendritic cell morphology,and the density of DCs varied from(500±50)cells/mm 2 epithelial surface in the large airways,to(60±10)cells/mm 2 epithelial surface in the small airways(P<0.05).The DCs characteristic of spiny and long processes were impressively observed by the scanning electron microscope.Compared with the control mice,the density,but not the distribution of NLDC-145 + DCs was significantly upregulated in the conducting airways of asthmatic mice(P<0.01).Compared with the asthmatic mice,the densities,but not the distributions of NLDC-145 + DCs were significantly down regulated in the conducting airways of the therapeutic groups with three varying concentrations of As_2O_3(P<0.01)while there were no statistical differences between each other(P>0.05). Conclusion: Our findings suggest that it might be an important therapeutic mechanism of As_2O_3 to downregulate not the distribution but the density of DCs in the conducting airways of asthmatic mice,and low dose of As_2O_3 has potential value in treating asthma.展开更多
A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid mem-branes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form...A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid mem-branes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form of the light-harvesting complex has been obtained by sucrose gradient ultracentrifugation. The result of SDS- PAGE shows that the light-harvesting complex is composed of at least five apoproteins in which a protein with apparent molecular weight of about 31 kD was never found in the ma-jor light-harvesting complex (LHC Ⅱ) from higher plants. The isolated Bryopsis corticulans light-harvesting complex contains a specific carotenoid, siphonaxanthin, as well as chlorophyll (Chl) a, Chl b, neoxanthin and violaxanthin. Si-phonaxanthin which is present in the light-harvesting sipho-naxanthin-chlorophyll a/b-protein complex of Bryopsis corticulans is responsible for enhanced absorption in the blue-green region (530 nm). Efficient energy transfer from both siphonaxanthin and Chl b to Chl a in Bryopsis corticu-lans LHCP, which has similar absorption and fluorescence emission spectra to those of the lutein-chlorophyll a/b-protein of higher plants, proved that molecular arrangement of the light-harvesting pigments was highly ordered in the Bryopsis corticulans LHCP. The siphonaxanthin-chlorophyll a/b-pro- teins allow enhanced absorption of blue-green light, the pre-dominant light available in deep ocean waters or shaded subtidal marine habitats.展开更多
文摘Objective: To investigate the effect of arsenic trioxide(As_2O_3)with three different concentration groups on the distribution and recruitment of dendritic cells(DCs)in the conducting airways of asthmatic mice. Methods: Fifty BALB/c mice were divided into 5 groups at random:control group,asthmatic group,therapeutic groups with low dose(1 mg/kg),moderate dose(5 mg/kg)and high dose(10 mg/kg)of As_2O_3.The immunohistochemistry,scanning electron microscope and computerized image analysis were applied to detect airway DCs,respectively. Results: We demonstrated from the control mice that all intraepithelial NLDC-145 + DCs throughout the respiratory tree could be accounted for a network of cells with dendritic cell morphology,and the density of DCs varied from(500±50)cells/mm 2 epithelial surface in the large airways,to(60±10)cells/mm 2 epithelial surface in the small airways(P<0.05).The DCs characteristic of spiny and long processes were impressively observed by the scanning electron microscope.Compared with the control mice,the density,but not the distribution of NLDC-145 + DCs was significantly upregulated in the conducting airways of asthmatic mice(P<0.01).Compared with the asthmatic mice,the densities,but not the distributions of NLDC-145 + DCs were significantly down regulated in the conducting airways of the therapeutic groups with three varying concentrations of As_2O_3(P<0.01)while there were no statistical differences between each other(P>0.05). Conclusion: Our findings suggest that it might be an important therapeutic mechanism of As_2O_3 to downregulate not the distribution but the density of DCs in the conducting airways of asthmatic mice,and low dose of As_2O_3 has potential value in treating asthma.
文摘A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid mem-branes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form of the light-harvesting complex has been obtained by sucrose gradient ultracentrifugation. The result of SDS- PAGE shows that the light-harvesting complex is composed of at least five apoproteins in which a protein with apparent molecular weight of about 31 kD was never found in the ma-jor light-harvesting complex (LHC Ⅱ) from higher plants. The isolated Bryopsis corticulans light-harvesting complex contains a specific carotenoid, siphonaxanthin, as well as chlorophyll (Chl) a, Chl b, neoxanthin and violaxanthin. Si-phonaxanthin which is present in the light-harvesting sipho-naxanthin-chlorophyll a/b-protein complex of Bryopsis corticulans is responsible for enhanced absorption in the blue-green region (530 nm). Efficient energy transfer from both siphonaxanthin and Chl b to Chl a in Bryopsis corticu-lans LHCP, which has similar absorption and fluorescence emission spectra to those of the lutein-chlorophyll a/b-protein of higher plants, proved that molecular arrangement of the light-harvesting pigments was highly ordered in the Bryopsis corticulans LHCP. The siphonaxanthin-chlorophyll a/b-pro- teins allow enhanced absorption of blue-green light, the pre-dominant light available in deep ocean waters or shaded subtidal marine habitats.
