茶多酚对膀胱移行上皮肿瘤EJ细胞内Ca^(2+)的影响

目的:研究茶多酚对膀胱移行上皮肿瘤EJ细胞内钙离子(Ca2+)的影响,以探讨茶多酚信号转导过程与EJ细胞内Ca2+浓度的关系。方法:体外培养膀胱肿瘤EJ细胞,采用噻唑蓝还原(MTT)法和激光扫描共聚焦显微镜测定不同浓度(10、20、40、80、160μg/ml)茶多酚作用前后的膀胱肿瘤EJ细胞生长抑制及Ca2+浓度随时间变化的情况。结果:不同浓度茶多酚对膀胱肿瘤EJ细胞株均有明显的抑制作用(P<0.05-0.01),并与时间、剂量存在依赖关系。随着茶多酚浓度的增加,细胞内的Ca2+浓度逐渐上升,最高增加到原水平的10倍以上。结论:茶多酚可引起膀胱肿瘤EJ细胞内Ca2+浓度的显著变化。证实Ca2+参与了膀胱肿瘤EJ细胞茶多酚信号转导过程。茶多酚具有诱导膀胱肿瘤细胞凋亡和影响肿瘤细胞膜Ca2+的通透性,使Ca2+在细胞非核部分聚积的双重功效。高Ca2+浓度可能是诱发肿瘤细胞凋亡的重要原因。

High concentration of calcium ions in Golgi apparatus

The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6NBD-ceramide, and then the single cells were examined by laser scanning confocal microscopy (LSCFM) for subcellular distributions of Ca2+ and the location of Golgi apparatus. In these cells, the intracellular Ca2+ were found to be highly concentrated in the Golgi apparatus. The changes of distribution of cytosolic high Ca2+ region and the Golgi apparatus coincided with the cell cycle phase.In calcium free medium, when the plasma membrane of the cells which had been loaded with fluo-3/AM were permeated by digitonin, the fluorescence of the Golgi region decreased far less than that of the cytosol. Our results indicated that the Glogi lumen retained significantly high concentration of free calcium.

Composite Cathode based on Mn-doped Perovskite Niobate-Titanate for Efficient Steam Electrolysis

Redox-active Mn is introduced into the B site of redox-stable perovskite niobate-titanate to improve the electrocatalytic activity of composite cathode in an oxide-ion-conducting solid oxide electrolyzer. The XRD and XPS results reveal the successful partial replacement of Ti/Nb by Mn in the B site of niobate-titanate. The ionic conductivities of the Mndoped niobate-titanate are significantly improved by approximately 1 order of magnitude in reducing atmosphere and 0.5 order of magnitude in oxidizing atmosphere compared with bare niobate-titanate at 800 ℃. The current efficiency for Mn-doped niobate-titanate cathode is accordingly enhanced by ,-25% and 30% in contrast to the bare cathode with and without reducing gas flowing over the cathode under the applied voltage of 2.0 V at 800 ℃ in an oxide-ion-conducting solid oxide electrolyzer, respectively.

Effects of drug serum of anti-fibrosis I herbal compound on calcium in hepatic stellate cell and its molecular mechanism

AIM: To investigate the effects of anti-fibrosis I herbal compound on intracellular Ca2+ in activated hepatic stellate cell (HSC) and to try to survey its molecular mechanism in treatment and prevention of hepatic fibrosis and portal hypertension. METHODS: The activated HSC line was plated on small glass cover slips in 24 wells culture dishes at a density of 5×106 /mL, and incubated in RPMI-1640 media for 24 h. After the cells were loaded with Fluo-3/AM, intracellular Ca2+ was measured with laser scanning confocal microscopy (LSCM). The dynamic changes of intracellular Ca2+, stimulated by carbon tetrachloride, TGF-β1 antibody and the drug serum of anti-fibrosis I herbal compound and under orthogonal design were determined by LSCM. The effect of anti-fibrosis I herbal compound on intracellular Ca2+ was observed before and after the addition of TGF-β1 antibody. RESULTS: The intracellular Ca2+ were significantly different in different dosage of carbon tetrachloride anti-fibrosis I formula drug serum, TGF-β1 antibody and different turn of these substance, but their interval time between CCl4 and TGF-β1 antibody, CCl4 and anti-fibrosis I drug serum had no influence on intracellular Ca2+. The result showed intracellular Ca2+ wasn't significantly different between rat serum without anti-fibrosis I and untreated group. After carbon tetrachloride stimulation, intracellular Ca2+ of activated HSC increased significantly when the dosage of CCl4 from 5 to 15 mmol/L, however, decreased significantly after stimulation by 5-20 μg/mL TGF-β1 antibody or 5-20 mL/L drug serum. Moreover, before and after the addition of TGF-β1 antibody, intracellular Ca2+ was significantly different. These results suggested that the molecular mechanism was independent of blocking TGF-β1 effects. CONCLUSION: Anti-fibrosis I herbal compound may treat hepatic fibrosis and decrease portal hypertension by inhibiting activated HSC contractility through decrease of intracellular Ca2+.

Phonon Dispersion and Thermodynamics Properties of CaF_2 via Shell Model Molecular Dynamics Simulations

The phonon and thermodynamics properties of face-centered cubic CaF2 at high pressure and high temperature are investigated by using the shell model interatomic pair potential within General Utility Lattice Program （GULP）. The phonon dispersion curves and the corresponding density of state （PDOS） in this work are consistent with the experimental data and other theoretical results. The transverse optical （TO） and longitudinal optical （LO） mode splitting as well as heat capacity at constant volume Cv and entropy S versus pressure and temperature are also obtained.

A novel autoantibody in patients with primary hypertension： antibody against L-type Ca^2＋ channel

Background Recently, it has been proposed that the autoantibodies against various cardiovascular receptors play a role in the pathogenesis of primary hypertension. In this study, we aimed to identify whether or not there are autoantibodies against cardiovascular L-type Ca^2＋ channels in patients with primary hypertension. Methods A peptide corresponding to the sequence 2-16 of the alc-subunit of L-type Ca^2＋ channel was used as an antigen to screen the autoantibodies from 90 patients with primary hypertension and 45 healthy controls by an enzyme-linked immunosorbent assay （ELISA）. The clinical data of 90 hypertensive patients were compared between patients with and without these autoantibodies. Results Serum from 3 （6.7%） of the 45 healthy controls, 33 （36.7%） of 90 hypertensives showed positive responses in ELISA （P 〈0.01）. The prevalence of such autoantibodies in two subgroups of hypertensives with coronary heart disease （9/21, 57.14%, P 〈0.05） and left ventricular diastolic dysfunction （28/63, 44.4%, P 〈0.05） was higher than in those without the corresponding complications. And the patients with such autoantibodies had lower E/A than patients without such autoantibodies （0.803±0.191 vs 1.004±0.322, P=0.002）. Conclusion There are autoantibodies against vascular L-tyPe Ca^2＋ channels in patients with primary hvnertension.

A stable lead halide perovskite nanocrystals protected by PMMA

To enhance the stability in humidity is very crucial to hybrid organic-inorganic lead halide perovskites in a broad range of applications. This report describes a coating stratergy of perovskite nanocrystals via poly- methylmethacrylate-introdnced ligand-assisted reprecipita- tion, using the interactions between the Pb cations on the surface of perovskite nanocrystals and the functional ester carbonyl groups in polymethylmethacrylate framework. The hydrophobic framework shields the open metal sites of hybrid organic-inorganic lead halide perovskites from being attacked by water, effectively retarding the diffusion of water into the perovskite nanocrystals. The as-prepared films demonstrate high resistance to heat and moisture. Additionally, the in- troduction of polymethylmethacrylate into ligand-assisted reprecipitation can effectively control the bulk precipitation and promote the stability of the perovskite solution.