钠氢交换蛋白1在胃癌中的表达及其对胃癌细胞增殖的影响

目的：观察钠氢交换蛋白1（Na＋／H＋,exchanger 1,NHE1）在人胃癌组织和胃癌细胞中的表达变化,以及对SGC‐7901胃癌细胞增殖的影响。方法采用实时逆转录聚合酶链式反应（real time PCR ,RT‐PCR）和免疫印迹（Western Bloting）技术检测比较NHE1在正常胃黏膜组织、胃癌组织、正常胃黏膜细胞株GES‐1和胃癌细胞株SGC‐7901中的表达;用不同浓度的NHE1特异性阻断剂[5‐（N‐乙基‐N‐异丙基）]阿米洛利[5‐（N‐ethyl‐N‐isopropyl） amiloride （EIPA ）]处理胃癌 SGC‐7901细胞24 h ,MTT法检测其对SGC‐7901细胞增殖的影响。结果 NHE1在人正常胃黏膜组织、胃癌组织、正常胃黏膜细胞和胃癌细胞中均有表达,但在人胃癌组织和 SGC‐7901胃癌细胞中,其mRNA 和蛋白表达水平均明显增高（P＜0．05）;EIPA10μm／mL ,20μm／mL ,30μm／mL处理,均能抑制胃癌SGC‐7901细胞的过度增殖（P＜0．05）,且呈现良好的剂量‐效应关系。结论 NHE1 mRNA和蛋白表达水平在胃癌中表达显著升高;NHE1特异性阻断剂EIPA能抑制胃癌SGC‐7901细胞的增殖,N H E1的改变可能与胃癌细胞的增殖密切相关。     

抑制P13K／PKB信号通路提高胃癌细胞化疗敏感性的研究

目的探讨磷脂酰肌醇3激酶（phosphatidylinositol 3-kinase，PI3K）抑制剂LY294002提高胃癌耐药细胞SGC7901／VCR和亲代细胞SGC7901对化疗药物敏感性的作用及其机制。方法MTT法分别检测胃癌细胞SGC7901和SGC7901／VCR对化疗药长春新碱（VCR）的敏感性；RT—PCR法和免疫细胞化学法检测LY294002处理前后多药耐药蛋白1（muhidrug resistance protein-1，MDR1）和x染色体连锁的凋亡抑制蛋白（X—linked inhibitor of apoptosis，XIAP）基因和蛋白水平；Western blot法检测LY294002处理前后细胞PKB总蛋白水平和磷酸化水平；并用流式细胞仪检测细胞的凋亡率。结果2×10^5-mol·L^-1 LY294002能明显增加SGC7901和SGC7901／VCR细胞对VCR的敏感性（P〈0．01），其IC50分别由（0．20±0．03）和（8．09±0．60）mg·L^-1降至（0．05±0．006）和（1．70±0．20）mg·L^-1；降低细胞MDRl和XIAP的基因和蛋白水平；降低磷酸化PKB水平，而对其总蛋白水平无影响；LY294002联合VCR用药后细胞凋亡率明显高于单独VCR处理（P〈0．01）。结论LY294002通过降低耐药基因MDR1和抗凋亡基因XIAP的表达，提高耐药和非耐药胃癌细胞对化疗药物的敏感性，此过程与抑制PI3K／PKB通路密切相关。     

API-2抑制胃癌细胞株SGC7901生长及其机制探讨

目的检测不同浓度API-2作用后磷酸化AKT（p-AKT）在胃癌细胞株SGC7901中的表达及细胞生长情况,并探讨Akt信号转导通路与消化道肿瘤发生发展的机制。方法胃癌细胞株SGC7901传代培养;MTT方法检测不同浓度API-2（0,2,4,6,8μmol/L）对胃癌细胞SGC7901的增殖抑制作用;免疫细胞化学染色和Western blot检测经API-2作用24h后胃癌细胞株SGC7901中p-AKT的表达。结果不同浓度API-2均可抑制SGC7901细胞的增殖,并呈浓度和时间依赖性;不同浓度API-2作用24h后,p-AKT蛋白表达均减少。结论API-2作用Akt信号转导通路的位点,减少p-AKT的表达。Akt信号转导通路与胃癌细胞株SGC7901的发生、发展有关。     

四嗪二甲酰胺诱导人胃癌AGS、SGC7901细胞系凋亡及其分子机制的实验研究

目的：观察四嗪二甲酰胺（ZGDHu-1）体外抑制胃癌细胞株AGS和SGC7901增殖并诱导细胞凋亡及其作用机制。方法：将不同浓度的ZGDHu-1与AGS和SGC7901细胞在体外培养，用台盼蓝染色、SRB法、5′溴-2′脱氧尿苷（Brdu）-ELISA法观察ZGDHu-1对AGS和SGC7901细胞增殖的抑制作用；用细胞形态学、DNA凝胶电泳、DNA含量及细胞周期分析、Annexin—V／PI双标记、Hoechst33258荧光染色等技术检测细胞凋亡。用流式细胞术观察经ZGDHu-1作用后AGS和SGC7901细胞bcl-2、bax、P53蛋白质和P38MAPK和Star3磷酸化表达的变化的表达改变。结果：ZGDHu-1能抑制AGS和SGC7901细胞增殖和活力，呈现作用时间和剂量的量效关系。AGS和SGC7901细胞与ZGDHu-1作用后，大部分细胞阻滞于G2-M期；出现典型的细胞形态改变，DNA片断化，亚G1峰检出并显著增加，Annexin—V＋／PI-表达升高，Hoechst33258荧光染色后出现凋亡细胞的特征性改变等均证实ZGDHu-1能诱导AGS和SGC7901细胞凋亡。AGS和SGC7901细胞经不同浓度的ZGDHu-1体外培养后，bcl-2蛋白有所下调，但主要是上调bax和P53蛋白，导致bax／bcl-2比值明显增高，均并呈现剂量依赖性；磷酸化P38MAPK表达增强，而磷酸化Stat3表达降低。结论：ZGDHu-1通过诱导细胞凋亡抑制AGS和SGC7901细胞增殖，其机制可能与上调bax和P53的表达，增强P38MAPK的磷酸化和抑制STAT3的活化有关。     

尼美舒利和舒林酸对人胃癌SGC-7901细胞COX-2和VEGF表达的影响及意义

目的观察尼美舒利、舒林酸对人胃癌SCK2-7901细胞环氧化酶2（COX-2）和血管内皮生长因子（VEGF）表达的影响,初步探讨尼美舒利、舒林酸抑制肿瘤血管生成机制。方法对人胃癌SCA2-7901细胞进行细胞培养,免疫组织化学、蛋白质印迹（Western lot）方法检测不同浓度尼美舒利、舒林酸作用后细胞COX-2、VEGF表达的改变。结果尼美舒利100、200μmol／L及舒林酸0．6、1．2mmol／L作用48h后人胃癌SCK2-7901细胞COX-2、VEGF蛋白表达率与阴性对照组相比明显降低（P〈20．05）,并且COX2与VEGF之间具有相关性（P〈005）。随着药物浓度的升高COX2和VEGF表达逐渐减弱。结论抑制COX-2的表达及由此引起的VEGF蛋白表达降低。在非甾体类抗炎药（NSAIDs）抑制肿瘤血管生长机制中可能具有一定作用。     

恩度联合紫杉醇热化疗对人胃癌SGC7901细胞株增殖抑制及凋亡影响

目的观察恩度联合紫杉醇热化疗对人胃癌SGC7901细胞株增殖抑制及凋亡的影响。方法取对数生长人胃癌SGC7901细胞株,分为对照组、41℃、42℃、43℃、44℃组,5组分别加入终浓度30nmol／L、60nmol／L、120nmol／L、240nmol／L、480nmol／L紫杉醇,于水浴箱中分别水浴0．5h、1h、1．5h,72h后MTr法测定紫杉醇热化疗对SGC7901胃癌细胞株细胞抑制作用并确定最佳紫杉醇浓度及热疗温度、热作用时间。流式细胞术分别检测对照组、恩度组（15mg／L）,紫杉醇热化疗组,恩度联合组（恩度＋紫杉醇热化疗）的细胞凋亡率并进行细胞周期分析。结果随着紫杉醇浓度以及温度的提高,SGC7901细胞株的抑制率逐步升高。在紫杉醇浓度480nmol／L、43℃作用1h条件下,SGC7901细胞株的抑制率达到70．99％,在各组最高。细胞凋亡率在对照组、恩度组、紫杉醇热化疗组以及联合治疗组分别为O．70％、1．48％、8．56％、12．97％。细胞周期分析可见与对照组相比恩度组的增殖期（S＋G2／M）细胞比例由（52．5±2．1）％下降到（42．3±2．0）％（P〈0．05）,紫杉醇热化疗组G2／M期细胞比例由（15．2±1．4）％上升至（32．1±2．2）％（P〈0．05）。与紫杉醇热化疗组相比,恩度联合治疗组的G2／M期细胞比例由（32．1±2．2）％下降到（19．9±1．3）％,而G1期比例由（30．5±1．7）％上升到（48．1±2．4）％（P〈0．05）。结论43℃热作用lh联合480nmol／L紫杉醇对人胃癌SGC7901细胞株增殖抑制作用在5组中最强,紫杉醇热化疗联合恩度后能够进一步增卉口时SCr7Q01冒癌细日白楼拍枷制他阐算诱导丘涸十     

胃癌组织中 COX－2与 PTEN 的表达及临床病理的关系

目的：探讨环氧化酶－2（COX－2）与第10号染色体同源丢失性磷酸酶和张力蛋白基因（PTEN）在胃癌组织中的表达及临床意义,探讨两者在胃癌发生、发展及转移中的相互作用。方法采用免疫组织化学 Elivision 方法分别检测 COX－2与 PTEN 在80例胃癌组织中的表达情况,并以80例癌旁组织作为对照,分析两者的相关性及其与胃癌临床病理特征的关系。结果（1）PTEN 在胃癌中的阳性表达率为41．3％（33／80）,显著低于癌旁组织中的阳性表达率80％（64／80）,差异具有统计学意义（P ＜0．01）。（2）COX－2在胃癌组织中的阳性表达为70％（56／80）,显著高于癌旁组织中的阳性表达15％（12／80）,差异具有统计学意义（P ＜0．01）。（3）PTEN 和 COX－2在胃癌组织中的表达与组织分化程度、有无淋巴转移及临床分期相关（P ＜0．05）;在胃癌组织中的表达与患者的年龄、性别无相关性（P ＞0．05）。（4）PTEN 和 COX－2两者在胃癌组织中表达呈负相关。结论COX－2、PTEN 可能参与胃癌的发生且影响癌细胞转移;胃癌中 COX－2与 PTEN 的表达呈负相关性;联合检测 COX－2、PTEN 的表达可能成为胃癌淋巴结转移预测指标及判断预后的重要指标。     

缺氧后处理对成年大鼠心肌细胞缺氧复氧损伤的保护作用

目的：通过建立成年大鼠心肌细胞缺氧复氧模型观察缺氧后处理的心肌保护机制。方法雄性SD大鼠,体质量250～350 g ,随机分为3组：正常组（NOR组）、缺氧组（H／R组）、缺氧后组（HP组）。采用激光共聚焦显微镜检测心肌细胞线粒体膜电位（mitochondrial membrane potential , MMP）、细胞内钙离子荧光强度以及 Western blot方法测定磷酸化 p38丝裂原活化蛋白激酶（p‐p38MAPK）表达量。结果（1）与正常组比较,H／R组和 HP组 MMP显著降低（P＜0．05）;HP组MMP明显高于 H／R组（P＞0．05）;（2）与正常组和 HP组比较,H／R组细胞内钙离子荧光强度显著升高（P＜0．01）;HP组和正常组间差异无统计学意义（P＞0．05）;（3）与正常组和 HP组比较,H／R组p‐p38MAPK表达量显著升高（P＜0．05）;HP组和正常组间表达量差异无统计学意义（P＞0．05）。结论缺氧后处理可对缺氧复氧成年大鼠心肌细胞产生保护作用,其机制可能与下调心肌细胞p‐p38M A PK 表达量、抑制线粒体膜电位下降以及防止钙超载进而抑制凋亡有关。     

Cerebral metabolism of [3H]-p-chloroamphetamine

The time-dependent metabolism of intraventricularly administered $\text{[}{}^3\text{H}\text{]-p-}\text{chloroamphetamine}$ was followed. The parent compound and its metabolites were recovered by high pressure liquid chromatography and characterized by high pressure liquid chromatography, thin-layer chromatography, and gas chromatography-mass spectrometry. By 4 hr after injection, two major toluene-soluble metabolites were present in brain. Their biological half-lives were different from the parent compound. On the basis of their analyses, one of the metabolites is p-chloronorephedrine, the other (P₃) is as yet unidentified. Pretreatment with Lilly 110140 prevented or markedly reduced the synthesis of both p-chloronorephedrine and P₃. Iprindole prevented the synthesis of p-chloronorephedrine. The P₃ appeared first in the brain then in the liver, suggesting that both of these organs can metabolize p-chloroamphetamine to this compound. The metabolites were recovered primarily from the nuclear and microsomal fractions following subcellular fractionation of the brain, with small quantities present in the synaptosomal fraction. The level of metabolites was higher in the brainstem than in the neocortex. Glutathione, administered simultaneously with p-chloroamphetamine either intraventricularly or intraperitoneally failed to alter the toxicity of p-chloroamphetamine.     

Clevudine University of Georgia/Abbott/Bukwang/Triangle/Yale University

The pyrimidine analog, clevudine (L-FMAU: 2'-fluoro-5-methyl-beta-L-arabinofuranosyluridine) is a potent antihepatitis B virus (HBV) and anti-Epstein-Barr virus (EBV) agent, discovered by researchers at the University of Georgia, in collaboration with Yale University and Bukwang. Bukwang transferred its technology to Triangle Pharmaceuticals in 1998 together with a license to develop clevudine worldwide except Korea [279649], [281942]. In June 1999, Triangle and Abbott Laboratories entered into a strategic alliance to copromote antiviral products including L-FMAU [326798]. In September 2000, Triangle Pharmaceuticals Inc initiated a 30-day phase I/II evaluation of clevudine in HBV-infected patients [381755]. Clevudine is a much less toxic derivative of the toxic agent P-D-FMAU. The mechanism of action of clevudine is not yet clear, but the agent induces a rapid decrease in HBV nucleic acid as doses increase from 0.3 to 10 mg/kg [319145]. It is believed that the target for clevudine lies in the viral replication mechanism. Clevudine is phosphorylated to the triphosphate form intracellularly. This is removed slowly from the cells, thus exerting a sustained inhibitory antiviral activity [178173], [320720], [320721].     

Spotlight from the American Society for Preventive Cardiology on Key Features of the 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guidelines on the Management of Blood Cholesterol

The 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol retains focus on recommendations for statin treatment in the original four statin-eligible groups [those with atherosclerotic cardiovascular disease (ASCVD), diabetes, low-density lipoprotein cholesterol (LDL-C) ≥ 190 mg/dL, and higher risk primary prevention] without the use of treatment initiation or target LDL-C levels from the earlier 2013 American College of Cardiology/American Heart Association (ACC/AHA) guideline, but has several new features. First, patients with primary prevention are divided into those who are at low (< 5%), borderline (5% to < 7.5%), intermediate (7.5% to < 20%), and high (≥ 20%) risk based on the ASCVD risk estimator. Moreover, the new guideline goes further to consider a wider range of factors [now called “risk enhancers”—premature family history of ASCVD, persistently high LDL-C, chronic kidney disease (CKD), metabolic syndrome, conditions specific to women, inflammatory diseases, and high-risk ethnicities] that can be used to better inform the treatment decision. Moreover, more detailed recommendations on how the results of coronary calcium scanning can be used to inform the treatment decision are provided, including how it may be used to “de-risk” certain patients for delaying or avoiding the use of statin therapy. There are also specific sections for cholesterol management in other patient subgroups including women, children, certain ethnic groups, those with CKD, chronic inflammatory disorders and HIV, as well as discussion on the management of hypertriglyceridemia. Importantly, for persons with known ASCVD, a distinction is made for those who are at “very high risk” based on having had two major ASCVD events or one major event and two or more other high risk conditions, such as diabetes or other major risk factors, or bypass surgery or percutaneous intervention. Finally, the concept of a threshold LDL-C for initiating a non-statin therapy (after considering highest tolerated statin dosage) is provided, with ezetimibe recommended as the key non-statin to be added if the LDL-C still remains ≥ 70 mg/dL for all ASCVD patients, and in those who are at “very high risk”, further consideration for using a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. While the new guideline does have greater detail (and arguably, complexity), the refinements provide a strategy for guiding the clinician to target both statin and non-statin therapy to those most likely to derive benefit.     

Pitavastatin Nissan/Kowa Yakuhin/Novartis/Sankyo

Pitavastatin (nisvastatin) is an HMG CoA reductase inhibitor being developed jointly by Nissan, Kowa Kogyo, Novartis and Sankyo for the potential treatment of atherosclerosis and hyperlipidemia.     

N-Nitroso-N-Methyldodecylamine and N-Nitroso-N-Methyltetradecylamine in household dishwashing liquids

Eleven household dishwashing liquids and four household surface cleaners were analysed for N-nitroso-N-methyldodecylamine and N-nitroso-N-methyltetradecylamine by gas chromatography with detection using a Thermal Energy Analyzer. Both nitrosamines were found in three of the dishwashing detergents and one of the surface cleaners. [1-¹⁴C]-N-Nitroso-N-methyldodecylamine was used to determine recoveries, which were between 65 and 88%. Levels of N-nitroso-N-methyldodecylamine ranged from 112 to 661 ppb and those of N-nitroso-N-methyltetradecylamine from 46 to 151 ppb. A simple method was developed to screen the products for N,N-dimethyldodecylamine-N-oxide, a surfactant ingredient suspected of being the source of these nitrosamines. By application of this method it was established that all of the products formulated with this amine oxide contained these two nitrosamines, whereas in products that did not contain this ingredient, these nitrosamines were not detected.     

PROTON AND POTASSIUM TRANSPORT BY H+/K+-ATPases

1. H⁺/K⁺-ATPases are members of the P-type ATPase multigene family. The prototypical H⁺/K⁺-ATPase is the protein that acidifies gastric luminal contents. The physiological and pharmacological significance of this pump has led to a detailed investigation of its biochemistry and molecular and cell biology. 2. Recently, a number of closely related H⁺/K⁺-ATPase isoforms have been discovered. These isoforms are present in organs other than the stomach, including the colon and kidney, where they contribute to acid—base and potassium homeostasis. The structure, expression and physiological roles of the gastric H⁺/K⁺-ATPase and other isoforms are reviewed.     

INTERACTIONS OF Na+, H2O2 AND THE Na+-Ca2+ EXCHANGER STIMULATE Ca2+ RELEASE IN CK1.4 CELLS

1. The present study aimed to demonstrate that interactions of cations, hydrogen peroxide (H₂O₂) and the Na⁺-Ca²⁺exchanger stimulate Ca²⁺ release and oscillations of cytosolic Ca²⁺ [Ca²⁺]i in non-transfected Chinese Hamster Ovary (CHO) C1 cells and in transfected CHO (CK1.4) cells that contained an expression vector coding the Na⁺-Ca²⁺ exchanger sequence. 2. The [⁴⁵Ca²⁺] uptake assay, fura-2 fluorescence imaging and 2² and 2³ factorial orthogonal statistics provide comparative, direct, efficient, quantitative and transient methods to delineate the effects of such interactions on Ca²⁺ influx, Ca²⁺release and [Ca²⁺]i in C1 and CK1.4 cells. 3. In contrast to the control of either Na⁺-, Ca²⁺- or H₂O₂-free or CI cells, an elevated [⁴⁵Ca²⁺] uptake was induced by Ca²⁺, Na⁺ and H₂O₂ individually and in combination, intracellular Ca²⁺ release was activated by H₂O₂ and by combinations of either H₂O₂ and Na⁺, H₂O₂ and the Na⁺-Ca²⁺ exchanger, Na⁺ and the Na⁺-Ca²⁺ exchanger or by H₂O₂, Na⁺ and the Na⁺-Ca²⁺ exchanger and a rise in [Ca²⁺]i was triggered by H₂O₂, Na⁺ and a combination of Na⁺ and the Na⁺-Ca²⁺exchanger. 4. These results indicate that interactions between H₂O₂, Na⁺ and the Na⁺-Ca²⁺ exchanger stimulate intracellular Ca²⁺mobilization via Ca²⁺-induced Ca²⁺ release mechanisms, ATP-activated G-protein coupled P_2y-purinoceptor-sensitive pathways, Na⁺-Ca²⁺ exchanger-mediated Ca²⁺ influx and cation-π interaction (a strong non-covalent force between the cation and the π face of an aromatic structure in the transmembrane protein). 5. The present findings provide important clues for understanding Ca²⁺ signal transduction mechanisms from the plasma membrane to the endoplasmic reticulum.     

Amlodipine/Valsartan/Hydrochlorothiazide

Amlodipine/valsartan/hydrochlorothiazide (HCTZ) is a fixed-dose combination of the well established antihypertensive agents amlodipine (a calcium channel antagonist), valsartan (an angiotensin II receptor antagonist), and HCTZ (a thiazide diuretic). In patients with moderate or severe hypertension, triple combination therapy with amlodipine + valsartan + HCTZ produced significantly greater reductions from baseline in mean sitting systolic and diastolic BP (msSBP and msDBP) than either valsartan + HCTZ, amlodipine + HCTZ, or amlodipine + valsartan in a large, 8-week, randomized, double-blind, multinational, phase III trial. Furthermore, the proportion of patients achieving overall BP control at endpoint was significantly greater with the triple combination regimen than with any of the dual regimens, with significantly more triple combination recipients achieving msSBP and msDBP control at each assessment throughout the trial. Subgroup analyses of this study suggested that amlodipine + valsartan + HCTZ was generally more effective in reducing BP and providing overall BP control than the dual combination therapies, irrespective of age, race, gender, ethnicity, or hypertension severity. Several smaller studies provide data that support the efficacy of amlodipine + valsartan + HCTZ in patients whose BP is inadequately controlled with amlodipine + valsartan, amlodipine + HCTZ, or valsartan + HCTZ dual combination therapy. Treatment with amlodipine + valsartan + HCTZ for up to 8 weeks was generally well tolerated in the large, phase III trial, with most adverse events being transient and of mild to moderate severity.     

EFFECTS OF THE OPIOID PEPTIDES [MET5]ENKEPHALIN-ARG6-PHE7 AND [MET5]ENKEPHALIN-ARG6-GLY7-LEU8 ON CHOLINERGIC NEUROTRANSMISSION IN THE RABBIT ISOLATED ATRIA

1. The effect of the opioid peptides [Met5]enkephalin-Arg6-Phe7 (MEAP) and [Met5]enkephalin-Arg6-Gly7-Leu8 (MEAGL) were compared with those of [Leu5]enkephalin and [D-Ala2,Met5]enkephalinamide (DAME) on cholinergic neurotransmission in the rabbit isolated atria. 2. Rabbit isolated atria had a resting rate of 190 beats/min. In the presence of the beta-adrenoceptor antagonist propranolol (0.3 mumol/l), atria responded to electrical field stimulation with a cholinergically mediated negative chronotropic response. The opioid peptides had no effect on the resting rate, but inhibited the negative chronotropic response to field stimulation. The IC50 values for inhibiting the cholinergic responses were 1.4 mumol/l for [Leu5]enkephalin (LE), 1.4 mumol/l for MEAP, 1.3 mumol/l for MEAGL and 0.2 mumol/l for DAME. Responses of a similar magnitude to exogenous acetylcholine were unaffected. 3. Thus, MEAP, MEAGL and LE had similar potencies but DAME was about seven times more potent in inhibiting cholinergic neurotransmission in the rabbit isolated atria. The site of inhibition appears to be prejunctional.