青蒿琥酯对人子宫内膜癌细胞RL95-2的生长抑制作用

目的 研究青蒿琥酯在体外对人子宫内膜癌RL95-2细胞的生长抑制作用及其可能机制.方法 通过MTT法实验观察青蒿琥酯在体外对RL95-2细胞的抑制作用;透射电镜观察癌细胞的形态学改变;免疫组化检测细胞浆Caspase3活性;流式细胞术观察青蒿琥酯对细胞周期的影响及检测细胞线粒体膜电位△ψm和细胞内ROS水平.结果 青蒿琥酯对RL95-2细胞具有增殖抑制作用,其半数细胞抑制浓度(IC50)为26.29 μg/ml.透射电镜见:细胞呈早期凋亡改变:核染色质聚集于核膜周围,呈团块状;免疫组化检测细胞浆Caspase3表达阳性;流式细胞仪检测:细胞周期阻滞发生在G0/G1期;细胞内ROS升高(P<0.05);细胞线粒体膜电位△ψm降低(P<0.05).结论 青蒿琥酯在体外作用于人子宫颈癌RL95-2细胞,可能通过诱导细胞凋亡抑制癌细胞增殖.     

高糖诱导人脐静脉内皮细胞衰老过程中活性氧与二甲基精氨酸二甲胺水解酶-非对称性二甲基精氨酸系统的变化

目的 观察高糖加速内皮细胞衰老过程中细胞内活性氧(ROS)水平与二甲基精氨酸二甲胺水解酶-非对称性二甲基精氨酸(DDAH-ADMA)系统的变化.方法 正常糖浓度培养液(5.5 mmol/L)和高糖培养液(11.0、22.0、33.0 mmol/L)作用于人脐静脉内皮细胞48 h后,用β-半乳糖苷酶染色鉴定衰老细胞,聚合酶链反应-酶联免疫吸附法(PCR-ELISA)检测端粒酶活性,流式细胞仪检测细胞内ROS水平,液质联用仪检测细胞上清液中ADMA含量及DDAH活性.结果 与正常糖浓度组相比,11.0、22.0、33.0 mmol/L高糖浓度组β-半乳糖苷酶染色阳性细胞率明显增高[(7.00±1.73)%、(12.67±2.03)%、(16.00±2.26)%比(4.00±1.33)%,P＞0.05、P＜0.05、P＜0.05],端粒酶活性显著下降[(91.32±4.01)%、(78.44±3.78)%、(56.04±3.35)%比100%,均P＜0.05];随细胞衰老程度加重,细胞内ROS水平(mfi)显著升高(159.84±27.52、188.99±18.77、244.56±20.96比117.11±18.76,P＜0.05或P＜0.01),ADMA水平(μmol/L)显著升高(0.78±0.14、0.88±0.18、1.08±0.15比0.70±0.12,P＞0.05、P＜0.05、P＜0.05),DDAH活性显著下降[(91.32±4.01)%、(78.44±3.78)%、(56.04±3.35)%比100%,均P＜0.05].结论 高糖可加速内皮细胞衰老进程,其机制可能与氧化应激水平增强、抑制DDAH活性使ADMA含量增加有关.

Abstract：

Objective To investigate the changes in reactive oxygen species (ROS) and dimethylarginine dimethylaminohydrolase-asymmetric dimethylarginine (DDAH-ADMA) system in the process of endothelial cell senescence after exposure to high glucose. Methods The human umbilical vein endothelial cells (HUVECs) were cultured with different concentrations of glucose, e.g. 5. 5 mmol/L (normal level),and high levels as 11. 0, 22. 0 and 33. 0 mmol/L. for 48 hours, respectively. Subsequently, SA-β-gal staining was used to evaluate senescence of cells. Telomerase activity was detected by polymerase chain reactionenzyme linked immunosorbent assay (PCR-ELISA). The intracellular ROS level was measured by flow cytometry. The ADMA concentration and DDAH activity were determined with high-performance liquid chromatography. Results Compared with normal glucose concentration group, after the endothelial cells were treated with high glucose concentration (11. 0 - 33. 0 mmol/L) for 48 hours, the number of SA-β-gal positive cells was increased significantly [(7.00±1. 73)%, (12. 67±2. 03)%, (16. 00±2. 26)% vs. (4. 00±1.33)%, P＞0.05, P＜0.05, P＜0.05] and the telomerase activity was inhibited dramatically [(91. 32±4.01)%, (78. 44±3. 78)%, (56. 04±3. 35)% vs. 100%, all P＜0. 05]. The ROS level (mfi) was increased in all high glucose groups (159. 84±27. 52, 188. 99±18. 77, 244. 56±20. 96 vs. 117.11±18. 76, P＜0. 05 or P＜0. 01). At the same time, the ADMA (μmol/L) production was increased (0. 78±0. 14, 0. 88±0.18,1. 08±0.15 vs. 0. 70±0. 12, P＞0. 05, P＜0. 05, P＜0. 05), and DDAH activity was decreased [(91. 32±4.01)%, (78.44±3.78)%, (56. 04± 3. 35)% vs. 100%, all P＜0.05]. Conclusion High glucose can accelerate endothelial cells senescence in dose-dependent manner and the underlying mechanism may be related to an increased oxidative stress and change in DDAH-ADMA system.     

IL-1alpha, IL-1ra and IL-8 are differentially induced by Candida in experimental oral candidiasis

OBJECTIVE: To investigate the expression of interleukin-1alpha (IL-1alpha), IL-1ra and IL-8 by the oral epithelium challenged by various Candida species. MATERIALS AND METHODS: In vitro candidiasis was induced by C. albicans wild type SC5314, its EFG1, CPH1 and secretory aspartyl proteinase (SAP) mutants and, ATCC isolates of C. albicans, C. tropicalis and C. dubliniensis using a reconstituted human oral epithelium (RHOE) model. IL-1alpha, IL-1ra and IL-8 levels in culture media were quantified by an enzyme-linked immunosorbent assay at 12, 24 and 48 h. Fungal invasion and IL-1ra expression in RHOE were detected by periodic acid-Schiff staining and immunohistochemistry. RESULTS: Overall, the invasive Candida induced relatively higher levels of IL-1alpha, IL-1ra and IL-8 in the culture media than the noninvasive isolates. IL-1alpha and IL-1ra levels induced by Candida with hyphal invasion were significantly higher (P < 0.05) than those induced by the isolates without hyphal invasion at 12, 24 and 48 h. Candida albicans SC5314 induced IL-1ra expression in RHOE at 12 and 24 h but not at 48 h consistent with its hyphal invasion; while the noninvasive mutants and non-albicans Candida induced IL-1ra expression at 48 h. CONCLUSIONS: The cytokine expression profiles in experimental oral candidiasis may be associated with the invasive potential of Candida.     

解偶联蛋白2表达对颗粒细胞抗氧化应激的影响

目的：通过观察体外培养颗粒细胞解偶联蛋白2（UCP2）表达变化对细胞抗氧化能力的影响，探讨颗粒细胞参与卵泡抗氧化应激的机制.方法：体外培养人颗粒细胞，分别加入过氧化氢（0.25 mmol/L），ATP（1 mmol/L），ATP＋过氧化氢，继续培养24 h，检测颗粒细胞凋亡发生率.结果：过氧化氢可以诱导颗粒细胞UCP2表达，应用ATP抑制UCP2表达后，细胞凋亡发生率增加，细胞抗氧化能力下降.结论：UCP2通过负反馈机制控制细胞内活性氧水平，参与颗粒细胞抗凋亡和对卵母细胞氧化应激保护作用.     

574例结核病病例细菌学检验结果分析

目的了解西安市分支杆菌病原菌感染的流行状况,为制定结核病防治措施提供科学依据。方法采用流行病学抽样调查方法,选取陕西省西安市为调查点,于2005年5～8月对其13个区级结防所就诊的所有病人进行调查,每个病人收集三份痰标本。采用痰涂片和痰培养法检测病人痰标本,鉴别培养基培养法鉴定分支杆菌菌种。结果574位病人,涂片阳性113人,阳性率为19.69%,培养阳性病人150人,阳性率26.13%。后者明显高于前者,两者之间的差异具有显著统计学意义(!2=360.50,P<0.01),两者联合阳性率为26.83%。从137例病例痰标本中分离到251株分支杆菌菌株,结核分支杆菌、牛分支杆菌、非结核分支杆菌(NTM)和混合感染的比例分别是67.88%、5.84%、11.68%、14.60%。结论细菌培养法可明显提高阳性率;NTM感染流行状况应予以足够的重视。     

Glycine induces enhancement of bactericidal activity of neutrophils

Severe bacterial infections are frequently accompanied by depressed neutrophil functions. Thus, agents that increase the microbicidal activity of neutrophils could add to a direct antimicrobial therapy. Lysophosphatidylcholine augments neutrophil bactericidal activity via the glycine (Gly)/glycine receptor (GlyR) α2/TRPM2/p38 mitogen-activated protein kinase (MAPK) pathway. However, the direct effect of glycine on neutrophil bactericidal activity was not reported. In this study, the effect of glycine on neutrophil bactericidal activity was examined. Glycine augmented bactericidal activity of human neutrophils (EC₅₀ = 238 μM) in a strychnine (a GlyR antagonist)-sensitive manner. Glycine augmented bacterial clearance in mice, which was also blocked by strychnine (0.4 mg/kg, s.c.). Glycine enhanced NADPH oxidase-mediated reactive oxygen species (ROS) production and TRPM2-mediated [Ca²⁺]_i increase in neutrophils that had taken up E. coli. Glycine augmented Lucifer yellow uptake (fluid-phase pinocytosis) and azurophil granule-phagosome fusion in neutrophils that had taken up E. coli in an SB203580 (a p38 MAPK inhibitor)-sensitive manner. These findings indicate that glycine augments neutrophil microbicidal activity by enhancing azurophil granule-phagosome fusion via the GlyRα2/ROS/calcium/p38 MAPK pathway. We suggest that glycine could be a useful agent for increasing neutrophil bacterial clearance.     

Novel Bacteriophage Specific against Staphylococcus epidermidis and with Antibiofilm Activity

Staphylococcus epidermidis has emerged as the most important pathogen in infections related to indwelling medical devices, and although these infections are not life-threatening, their frequency and the fact that they are extremely difficult to treat represent a serious burden on the public health system. Treatment is complicated by specific antibiotic resistance genes and the formation of biofilms. Hence, novel therapeutic strategies are needed to fight these infections. A novel bacteriophage CUB-EPI_14 specific to the bacterial species S. epidermidis was isolated from sewage and characterized genomically and phenotypically. Its genome contains a total of 46,098 bp and 63 predicted genes, among which some have been associated with packaging and lysis-associated proteins, structural proteins, or DNA- and metabolism-associated proteins. No lysogeny-associated proteins or known virulence proteins were identified in the phage genome. CUB-EPI_14 showed stability over a wide range of temperatures (from −20 °C to 50 °C) and pH values (pH 3–pH 12) and a narrow host range against S. epidermidis. Potent antimicrobial and antibiofilm activities were observed when the phage was tested against a highly susceptible bacterial isolate. These encouraging results open the door to new therapeutic opportunities in the fight against resilient biofilm-associated infections caused by S. epidermidis.     

Bruceine D inhibits HIF-1α-mediated glucose metabolism in hepatocellular carcinoma by blocking ICAT/β-catenin interaction

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths, characterized by highly hypoxic tumor microenvironment. Hypoxia-inducible factor-1α (HIF-1α) is a major regulator involved in cellular response to changes of oxygen levels, supporting the adaptation of tumor cells to hypoxia. Bruceine D (BD) is an isolated natural quassinoid with multiple anti-cancer effects. Here, we identified BD could significantly inhibit the HIF-1α expression and its subsequently mediated HCC cell metabolism. Using biophysical proteomics approaches, we identified inhibitor of β-catenin and T-cell factor (ICAT) as the functional target of BD. By targeting ICAT, BD disrupted the interaction of β-catenin and ICAT, and promoted β-catenin degradation, which in turn induced the decrease of HIF-1α expression. Furthermore, BD could inhibit HCC cells proliferation and tumor growth in vivo, and knockdown of ICAT substantially increased resistance to BD treatment in vitro. Our data highlight the potential of BD as a modulator of β-catenin/HIF-1α axis mediated HCC metabolism.     

广西产石斛属植物两新种

本文报道石斛属植物两新种:修仁右斛Dendrobium xiurenense M.F.Li et G. J.Xu,永福石斛D.yongfuense M.F.Li et G.J.Xu,用拉丁文和中文对其特征作了集要描述。     

Enhanced generation of reactive oxygen species and photocatalytic activity by Pt-based metallic nanostructures: the composition matters

The modification of semiconductor nanostructures with metallic nanocomponents can promote the separation of electron/hole from photoexited semiconductors by forming heterojunctions, thus exhibit enhanced photocatalytic activities and potential applications. In this study, Pt-based NPs, including Pt, PtCu, and PtCuCo are employed as model co-catalysts to comparatively study their capability to enhance the photocatalytic activity of TiO₂ nanosheets. It was found that each of Pt, PtCu, and PtCuCo can greatly enhance the photocatalytic activity of TiO₂ toward degradation of organic dyes. Using electron spin resonance spectroscopy, we demonstrated that deposition of Pt-based NPs resulted in more production of reactive oxygen species including hydroxyl radicals, superoxide, and singlet oxygen. The enhancing effects of Pt-based NPs on generation of ROS and photocatalytic activity showed same trend: PtCuCo?>?PtCu?>?Pt. The mechanism underlying the enhancement differences in Pt-based NPs may be mainly related to electronic structure change of Pt in alloying with Cu and Co. These results are valuable for designing hybrid nanomaterials with high photocatalytic efficiency for applications in water purification and antibacterial products.