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21.
AIM: To study the electrophysiological characteristics of ion channels of stem cell derived cardiomyocytes(SCDC) of mouse. METHODS: Embryonic stem cells of D3 line(ES-D3) were cultured on the MEF feeder layer with BRL conditioned medium, and fetal mouse heart cells(FMHC)were cultured in vitro. Then ES-D3 cells were induced to differentiate into many kinds of cells. SCDC were harvested on day 12 after differentiation initiating and identified by electro-microscope and immunocytochemistry. SCDC and FMHC were prepared for the patch-clamp research. Sodium and calcium currents together were elicited and compared between SCDC and FMHC. RESULTS: The current characteristics of sodium and calcium channels of SCDC were very similar to FMHC. CONCLUSION: The functional expression of ion channels occurred during ES-D3 cells differentiation and the electrophysiological characteristics of sodium and calcium channels of SCDC are very similar to FMHC. 相似文献
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研究了两种β-环糊精的衍生物甲基-β-环糊精(MCD)和羟丙基-β-环糊精(HPCD)对甲基对硫磷的增溶作用和对紫外光降解的影响。结果表明:MCD和HPCD能增强甲基对硫磷的水溶性,在25℃下,20 g/L的MCD和HPCD溶液中,甲基对硫磷溶解度比在纯水中分别提高了21.91和17.92倍;另外,3 g/L、6 g/L MCD和HPCD分别处理的甲基对硫磷,其光降解速率分别加快了4.87~6.85倍。增溶作用和光敏效应主要是由于MCD和HPCD与甲基对硫磷形成包合物引起的。 相似文献
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AIM: In order to study the relationship between the ERK and p38 MAPK activation and the protection of 11, 12-epoxyeicosatrienoic acid (11, 12-EET) and ischemia preconditioning (IP), the effects of 11, 12-EET and ischemic preconditioning on phosphorylated ERK and p38 MAPK during ischemia and reperfusion in rat myocardium were examined. METHODS: The rat heart was subjected to ischemia for 5 min by ligating the left anterior descending coronary artery followed by reperfusion for 5 min (two times) to undergo ischemia preconditioning. The rats were divided into 5 groups: (1) control; (2) sham group; (3) ischemia/reperfusion (I/R) group, in which the rat heart suffered from 60 min ischemia followed by 30 min reperfusion; (4) IP plus I/R group; (5) EET plus I/R group, in which 6.28×10-8 mol/L 11, 12-EET was injected intravenously 20 min before I/R. The heart function was examined, and phosphorylated ERK and p38 MAPK were detected by Western blot. RESULTS: At 30 min reperfusion, +dp/dtmax, -dp/dtmax and LVDP decreased significantly in I/R group compared with sham group, IP plus I/R group and EET plus I/R group; Phosphorylated ERK1/2 level was higher in I/R group than sham group, but was lower in I/R group than IP plus I/R group and EET plus I/R group; Phosphorylated p38 MAPK level was lower in control, sham, IP plus I/R and EET plus I/R group than I/R group. CONCLUSION: 11,12-EET protects rat heart against ischemia/reperfusion injury, the mechanism may be related to activation of ERK1/2 and inhibition of p38 MAPK. 相似文献
25.
AIM: This study was designed to investigate the secretion of VEGF and its receptor (flt-1 or flk-1/KDR) protein by cultured bovine thoracic aortic endothelial cells treated with various insulin concentrations. METHODS: Endothelial cells was isolated from bovine thoracic aorta, and cultured in serum-free medium, then incubated with different insulin concentrations (30 mU/L, 300 mU/L, 3 000 mU/L). The level of VEGF and its receptor (flt-1 or flk-1/KDR) protein were detected by immunohistochemical staining. RESULTS: As compared with no insulin group, the expression of VEGF protein in low insulin concentration (30 mU/L and 300 mU/L) groups were significantly increased (P<0.01). The expression of VEGF protein in high insulin concentration (3 000 mU/L) group was significantly decreased (P<0.05). Howerer, no difference of the expression of VEGF receptor (flt-1 or flk-1/KDR) protein among all groups (P>0.05) was observed. CONCLUSION: Low concentration insulin up-regulates the VEGF protein expression while high concentration insulin down-regulates the VEGF protein expression in bovine thoracic aortic endothelial cells, but insulin had no directly effect on the VEGF receptor (flt-1 or flk-1/KDR) protein expression in bovine thoracic aortic endothelial cells. 相似文献
26.
安婀珍蝶Actinote anteas(Doubleday & Hewitson)是薇甘菊的天敌,取食薇甘菊Mikania micrantha Kunth.的叶片,能有效的控制薇甘菊的蔓延和生长。在广州市和深圳龙岗进行的观察表明,在实验室条件下,安婀珍蝶一年生长3代~4代。世代平均历期为112.44±1.18天;卵期平均为11.44±1.18天;幼虫期平均为82.54±4.05天;蛹期平均为12.98±1.31天;成虫期平均为7.33±0.80天。本文还记述了该蝶各虫态的形态特征、生活习性及其天敌等。 相似文献
27.
JIANG Xun ZENG Yao-ying HE Xian-hui XU Li-hui DI Jing-fang FENG Zheng ZHAO Jing-xian WANG Qing WANG Tong SHI Jian-bo 《园艺学报》2004,20(6):924-928
AIM: To investigate the effect of enhanced green fluorescence protein (EGFP) gene transfection on the cell cycle distribution of primary cultured human chondrocytes in order to establish a tracking method of cultured human nasoseptal chondrocytes. METHODS: pEGFP-N1 plasmid was amplified in E.coli, and purified by high purity kit. Primary cultured human chondrocytes,which were initially obtained from the nasoseptal cartilage, were cultured in vitro and transferred with pEGFP-N1 by means of electroporation with Amaxa nucleofector device. Transfering process and transient expression were evaluated by laser scanning confocal microscope (LSCM), the transfer efficiency and the cell cycle distribution were evaluated by flow cytometry. RESULTS: There was significant expression of EGFP at 24 h after transferring. The transfection efficiency of pEGFP-N1 into primary cultured human chondrocytes reached 35.37% at 48 h. It didn't affect the process of cell adherance and had no effect on the cell cycle distribution. CONCLUSION: Primary cultured human chondrocytes, which were transfected with pEGFP, are alive in vitro, and the transferring process doesn't affect the cell cycle distribution. These results suggest that pEGFP-N1 is an ideal transient expression vector for primary cultured human chondrocytes and it might be a well tracer in construction tissue engineered cartilage. 相似文献
28.
Expression of DNA repair gene ERCC1 and its relationship with PAH-DNA adducts in lung cancer tissues
AIM: To investigate the expression of nucleotide excision repair gene ERCC1 and its relationship with PAH (polycyclic aromatic hydrocarbons)-DNA adducts in lung cancer tissues. METHODS: ERCC1 mRNA expression and the PAH-induced DNA adducts were detected in 150 lung cancer tissues, 120 adjacent lung tissues without cancer cells, 40 benign lung lesions and 40 normal lung tissues. The effects of some exposure factors on the expression of ERCC1 gene and the connection between ERCC1 and PAH-DNA adduct was analyzed. RESULTS: Reduced expression levels of ERCC1 were observed in 46 of 150 (30.7%) lung cancer specimens and 1 of 40 (2.5%) normal lung tissues. Smoking may suppress the expression of ERCC1 gene. The level of PAH-DNA adduct was negatively correlated with the expression of ERCC1 gene, the Spearman coefficient was -0.648, P<0.01. CONCLUSION: ERCC1 is an important nucleotide excision repair gene and may participate in the repair of DNA damage, such as PAH-DNA adduct. Low expression of ERCC1 may play an important role in the development of human lung cancer. 相似文献
29.
ZHU Ying-yuan WANG Zi-neng ZENG Yi-ke ZHENG Pei-e XU Jian-ping GUO Zu-wen TANG Fu-xing 《园艺学报》2004,20(6):1038-1041
AIM: To obverse the expression and localization of urocortin on ultrathin cryosections of syncytiotrophoblast of human term placenta with immunocytochemistry technique under transmission electron microscope. METHODS: The human term placenta tissue from Cesarean delivery and normal labor were fixed in 4% paraformaldehyde, and then divided into two parts. One part was for regular immunocytochemistry under microscope, and the other part was used to prepare ultrathin cryosections for immunocytochemistry under transmission electron microscope. RESULTS: 1.Uroncortin mainly distributed in cytoplasm of syncytiotrophoblast of human term placenta under microscope. Urocortin also appeared in cytoplasm in some stromal cells. 2. Under transmission electron microscope, the anti-urocortin gold particles were observed in cytoplasm of syncytioptrophoblast ultrathin cryosections and sited on rough-surfaced endoplasmic reticulum. The anti-urocortin gold particles also appeared on nucleus and nuclear membrane of syncytiotrophoblast. CONCLUSION: Syncytiotrophoblast of human term placenta synthesized and secreted urocortin. The internalization of urocortin within syncytiotrophoblast nuclear indicates that urocortin may act as intracrine. 相似文献
30.