Smad3基因调控食管鳞癌发生及 EGCG 干预研究

目的：探讨 Smad3基因与食管鳞癌发生及发展关系,表没食子儿茶素没食子酸酯（ epigallocatechin-3-gallate,EGCG）抑制食管癌细胞 Ec9706增殖作用及调控 Smad3基因表达水平。方法 RT-PCR 方法检测44例食管鳞癌及正常食管组织中 Smad3基因表达水平,流式细胞术方法检测38例原发性食管鳞癌和20例正常食管组织的细胞周期,不同浓度 EGCG（0、100、200、300 mg/ L）作用 Ec9706细胞24、48 h 后流式细胞术检测细胞增殖及 Smad3蛋白表达水平。结果食管鳞癌组织中 Smad3 mRNA 表达水平显著低于正常食管组织中的表达水平,差异有统计学意义（P <0.05）。食管鳞癌组织增殖指数显著高于正常食管组织（ P <0.05）。不同浓度 EGCG 作用 Ec9706细胞24 h后,细胞增殖指数显著降低（ P <0.05）,而 Smad3蛋白表达水平显著增高（ P <0.05）。结论 Smad3在食管鳞癌中的异常表达参与了食管鳞癌发生及发展,EGCG 具有抑制食管鳞癌生长作用与调控 Smad3蛋白表达有关。     

伪士的宁对人结肠癌HT-29细胞凋亡的影响及其机制研究

目的:探讨伪士的宁对人结肠癌HT-29细胞凋亡的影响及其机制。方法:取人结肠癌HT-29细胞,随机分为空白组和低、中、高剂量伪士的宁组(125、250、500μmol/L),加入不含药培养基或含相应浓度伪士的宁的培养基培养48 h。采用流式细胞仪检测细胞凋亡情况和线粒体跨膜电位;采用Western blotting法检测细胞中P53、Caspase-3、Caspase-9、兔源DNA修复酶(c-PARP)、Bcl-2的蛋白表达水平。结果:与空白组比较,低、中、高剂量伪士的宁组细胞凋亡率显著升高,线粒体跨膜电位均显著降低(P<0.01),且均呈现浓度依赖趋势。中、高剂量伪士的宁组细胞中P53、Caspase-3、Caspase-9、c-PARP蛋白表达水平较空白组均显著升高,低、中、高剂量伪士的宁组细胞中Bcl-2蛋白表达水平则显著降低(P<0.05或P<0.01)。结论:伪士的宁可能通过上调P53蛋白、下调Bcl-2蛋白的表达,改变线粒体膜电位,然后激活Caspase-3、c-PARP、Caspase-9的表达,进而激活内源性线粒体通路,发挥促进HT-29细胞凋亡的作用。     

穿心莲内酯对人食管癌Ec9706细胞增殖和凋亡的影响

目的:探讨穿心莲内酯(AD)对人食管癌Ec9706细胞增殖、克隆形成、细胞周期和细胞凋亡的影响。方法:分别以四甲基偶氮唑蓝(MTT)比色法和平板克隆形成法评价AD对Ec9706细胞增殖和克隆形成的抑制作用;通过流式细胞术、细胞原位凋亡检测(TUNEL)和Annexin·V／PI法观察AD诱导细胞凋亡。结果:AD显著抑制Ec9706细胞的增殖,IC_(50)值为28．6μg·mL~(-1),也显著抑制Ec9706细胞的克隆形成,IC_(50)值为1．7μg·mL~(-1)。AD 30和60μg·mL~(-1)组G_0/G_1期的细胞比例较对照组显著增加[(65．6±1．9)%,(60．5±1．1)% vs．(50．6±0．9)%,P＜0．01],凋亡细胞比例也显著大干对照组[(17．9±2．6)%,(39．4±1．7)％vs．(0．5±0．2)%,P＜0．01]。结论:AD抑制人食管癌Ec9706细胞的增殖和克隆的形成,阻滞细胞周期于G_0/G_1期并诱导细胞凋亡。     

丙戊酸钠诱导K562细胞凋亡的机制探讨

目的 探讨丙戊酸钠(VPA)诱导K562细胞凋亡的可能机制.方法 将K562细胞分为经VPA 2.0mmol/L处理的实验组(A组)和正常对照组(B组),分别培养24、48、72 h.流式细胞术检测细胞凋亡率和线粒体膜电位改变,分光光度法检测半胱氨酸天门冬氨酸蛋白酶(Caspase)8、Caspase-9蛋白活性.结果 A组细胞凋亡率、细胞线粒体跨膜电位破坏率呈时问依赖性地增加,且明显高于B组(P<0.05);与B组相比,A组不同时间的Caspase-8、Caspase-9活性均上调(P<0.05).结论 VPA诱导K562细胞凋亡的机制可能与线粒体跨膜电位崩溃或死亡途径有关.     

二甲基甲酰胺对HL7702肝细胞毒性及线粒体膜电位的影响

目的观察二甲基甲酰胺(DMF)对HL7702肝细胞的细胞活力、凋亡及线粒体膜电位的影响,探讨DMF引起肝细胞凋亡的可能机制。方法 HL7702肝细胞给予50、100、150、200和250 mmol/L DMF处理,于24 h后检测其细胞存活率,乳酸脱氢酶(LDH)释放量。根据细胞毒性测试结果设置对照组及DMF染毒组(200 mmol/L)。流式细胞术检测DMF对HL7702细胞凋亡以及对线粒体膜电位的影响。结果 DMF剂量依赖性地降低HL7702细胞的存活率,其中150、200和250 mmol/L DMF组与对照组相比,细胞存活率明显降低;并且,随着DMF染毒浓度增加,释放至细胞外的LDH的含量增加,与DMF浓度呈正相关。200 mmol/L DMF染毒24 h后,与对照组相比,细胞凋亡率增加,差异有统计学意义(P0.001),线粒体膜电位降低,差异也有统计学意义(P0.001)。结论 DMF对HL7702细胞的毒性作用具有剂量依赖性,DMF引起HL7702线粒体膜电位的改变与DMF导致细胞凋亡有关。     

BNIP3介导锰经线粒体凋亡途径诱导SH-SY5Y细胞凋亡的研究

目的探讨线粒体蛋白BNIP3在锰诱导线粒体依赖的SH-SY5Y细胞凋亡中的作用。方法取对数生长期的人神经母细胞瘤SH-SY5Y细胞,经MnCl_2处理24 h后应用透射电子显微镜直接观察MnCl_2作用下SH-SY5Y细胞的凋亡情况,使用流式细胞仪检测SH-SY5Y细胞线粒体膜电位(Δψm),通过蛋白免疫印记法(Western blot)检测BNIP3及凋亡相关蛋白Caspase-3的表达。并使用shRNA将SH-SY5Y细胞中的BNIP3沉默,观察BNIP3对MnCl_2诱导的SH-SY5Y细胞凋亡、线粒体膜电位丢失(Δψm)及凋亡相关蛋白Caspase-3表达的影响。结果 MnCl_2可使线粒体膜电位逐渐丢失(F=49.061,P0.01)、并使线粒体蛋白BNIP3及凋亡相关蛋白Caspase-3的表达随着MnCl_2浓度的提高而上升(F=334.832,F=299.902,均P0.01)、明显增加SH-SY5Y细胞的凋亡小体个数,上述差异均有统计学意义。沉默BNIP3(F=1.301,P=0.318,t=32.647,P0.01)可以减少MnCl_2诱导线粒体膜电位的丢失(F=1.786,P=0.252;t=20.290,P0.01),减少凋亡相关蛋白Caspase-3的表达(F=2.816,P=0.168;t=22.073,P0.01)并使SH-SY5Y凋亡小体的个数减少,上述差异均有统计学意义。结论在MnCl_2通过线粒体凋亡途径诱导SH-SY5Y细胞凋亡的过程中BNIP3起到了重要作用,这种调控机制可能是锰产生神经毒性的作用机制之一。     

神经细胞缺氧/缺糖损伤后阿司匹林的线粒体保护研究

目的观察神经细胞缺氧/缺糖损伤后线粒体膜电位(MMP)和凋亡的变化情况及阿司匹林的保护作用。方法用体外培养7 d的Wistar大鼠皮质神经细胞,随机分为正常对照组、缺氧/缺糖模型组、缺氧/缺糖加100μmol/L浓度阿司匹林组。缺氧/缺糖2 h处理后,四甲基偶氮唑盐(MTT)比色分析法检测神经元线粒体活性;流式细胞术检测神经元线粒体膜电位、双染法检测不同组神经元的凋亡情况。结果缺氧/缺糖损伤2 h后,模型组的线粒体活性和MMP水平较对照组显著降低(P<0.01)。细胞凋亡百分率均较对照组显著升高(P<0.01)。而阿司匹林组能显著提高神经元线粒体活性、膜电位,降低细胞凋亡的百分率。结论阿司匹林可抑制缺氧/缺糖损伤所致的神经元线粒体活性和膜电位的降低、稳定线粒体膜电位,抑制神经元凋亡,起到神经元保护作用。     

表没食子儿茶素没食子酸酯对鱼藤酮诱导PC12细胞损伤的保护作用

目的探讨表没食子儿茶素没食子酸酯(EGCG)对鱼藤酮诱导的嗜铬细胞瘤PC12细胞损伤的保护作用及其可能机制。方法将培养的大鼠PC12细胞分别加入EGCG1,5和10μmol.L-1预处理30 min后加入鱼藤酮250 nmol.L-1继续作用24 h。MTT比色法检测细胞存活率,Hoechst33258染色观察细胞核形态的变化,流式细胞仪检测细胞凋亡率,JC-1染色检测线粒体膜电位变化。结果与鱼藤酮模型组存活率(77.0±1.3)%相比,EGCG1,5和10μmol.L-1组细胞存活率显著增加(P<0.05),分别为(79.8±2.3)%,(82.4±2.2)%和(88.3±2.0)%。Hoechst33258染色发现,EGCG组细胞核形态明显改善。与正常对照组比较,模型组细胞凋亡率增加8.2倍;与鱼藤酮模型组比较,EGCG组细胞凋亡率分别下降46%,25%和63%,差异具有统计学意义(P<0.01)。流式细胞仪检测鱼藤酮组凋亡率为33.8%,EGCG 1,5和10μmo.lL-1组的凋亡率下降至30.6%,14%和15.7%。与模型组相比,EGCG1,5和10μmol.L-1组线粒体膜分别增高了2.48,3.96和4.04倍,差异具有统计学意义(P<0.01)。结论 EGCG具有抑制鱼藤酮诱导的细胞凋亡作用,其机制可能与其稳定线粒体膜电位有关。     

迷迭香酸通过线粒体通路诱导骨肉瘤MG-63细胞凋亡的研究

目的研究迷迭香酸通过线粒体通路诱导骨肉瘤MG-63细胞凋亡的作用。方法体外培养MG-63细胞,将10、20、30、40、50、60μmol/L迷迭香酸作用于MG-63细胞,MTT和CCK-8法检测迷迭香酸对细胞生长的影响;AO/EB染色法观察细胞凋亡;流式细胞仪检测对细胞凋亡和细胞周期的影响;Western blotting法检测Cyt-c、Caspase-3、Bax和Bcl-2蛋白表达水平。结果 MTT和CCK-8结果显示迷迭香酸可浓度相关性地抑制MG-63细胞的生长;AO/BE染色可看到迷迭香酸组凋亡细胞明显增加;流式细胞仪检测结果显示迷迭香酸可浓度相关性地促进MG-63细胞凋亡,并将细胞周期阻滞在S期;Western blotting法结果显示与对照组比较,迷迭香酸20、40、60μmol/L组的Bax、Caspase-3和Cyt-c蛋白表达水平明显增加(P0.05、0.01);与对照组比较,迷迭香酸20、40、60μmol/L组的Bcl-2蛋白表达水平则明显降低(P0.05、0.01),且呈剂量相关性。结论迷迭香酸可显著促进人骨肉瘤MG-63细胞凋亡,其机制可能与调控线粒体凋亡通路有关。     

姜黄素对人肝癌Bel-7402细胞的抑制作用研究

目的 研究姜黄素对人肝癌Bel-7402细胞的抑制作用,并探讨其作用机制.方法 实验分为4组,分别为对照组和10、20和40 μmol/L姜黄素组.采用噻唑蓝(MTT)法检测细胞的活性;流式细胞术结合Annexin V-FITC/PI双染检测Bel-7402细胞的凋亡情况;RT-PCR法检测Bax和Bcl-2的mRNA的表达,Western blot检测细胞色素C和Caspase-3蛋白的表达.结果 姜黄素显著抑制Bel-7402细胞的活性(P＜0.01).姜黄素处理后,Bel-7402细胞的凋亡率明显增加,与对照组相比具有统计学差异(P＜0.05),且具有剂量依赖性.另外,姜黄素使Bax的mRNA表达上升,Bcl-2的mRNA表达下降,Bax/Bcl-2比值明显上升(P＜0.05).同时,细胞色素C和Caspase-3蛋白的表达均显著上调(P＜0.01).结论 姜黄素可以抑制Bel-7402细胞的活性和增殖,促进Bel-7402细胞的凋亡,其机制可能与与姜黄素激活Bel-7402细胞线粒体凋亡途径有关.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

Gender-related symptoms and correlates of alcohol dependence among men and women with a lifetime diagnosis of alcohol use disorders

This study explored gender-related symptoms and correlates of alcohol dependence in a crosssectional study of 150 men and 150 women with a lifetime diagnosis of alcohol use disorders (AUD). Participants were recruited in equal numbers from treatment settings, correctional centres and the general community. Standardized measures were used to determine participants' use of substances, history of psychiatric disorders and psychosocial stress, their sensation seeking and family history of substance use and mental health disorders. Multivariate analyses were used to detect patterns of variables associated with gender and the lifetime severity of AUD. Men had a longer history of severe AUD than women. Women had similar levels of alcohol dependence and medical and psychological sequelae as men, despite 6 fewer years of AUD. More women than men had a history of severe psychosocial stress, severe dependence on other substances and antecedent mental health problems, especially mood and anxiety disorders. There were differences in family history of alcohol-related problems approximating same-gender aggregation. The severity of a lifetime AUD was predicted by its earlier age at onset and the occurrence of other disorders, especially anxiety, among both men and women. The limitations in the generalizability of these findings due to sample idiosyncrasies are discussed.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.