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1.
目的:研究自噬特异性抑制剂3-甲基腺嘌呤(3-methyladenine,3-MA)对奥沙利铂(oxaliplatin,OX)诱导的肝癌细胞系HepG2存活率的影响,并探讨其机制。方法:MDC与DAPI双重染色后,采用荧光显微镜对自噬进行定性观察;以CCK8检测3-MA抑制剂自噬前后,经OX诱导的HepG2细胞存活率;并用RT-PCR检测自噬特异性基因LC3表达的变化,以Western印迹法分别检测自噬特异性蛋白LC3及凋亡活化蛋白Caspase-3的变化。结果:OX可诱导肝癌细胞HepG2产生自噬,且自噬在基因及蛋白水平的表达均增加;3-MA与OX联合作用可明显增强HepG2细胞的凋亡。结论:OX诱导肝癌细胞系HepG2凋亡的过程中自噬起到保护性作用;抑制自噬可明显增强OX诱导的HepG2细胞凋亡。3-MA可能为提高肝癌对化疗敏感性提供新思路。  相似文献   

2.
目的:研究S腺苷甲硫氨酸(SAMe)在急性缺血/缺氧过程中对肝癌细胞HepG2的生物学作用,并通过检测自噬的变化探讨其可能机制。方法:real time-PCR检测自噬特异性基因(Beclin 1)表达的变化;吖啶橙染色后,采用荧光显微镜定性观察自噬;CCK-8法检测HepG2细胞的成活率;用AnnexinⅤ/PI流式细胞仪检测细胞凋亡的变化。结果:SAMe可诱导HepG2细胞的自噬,在单纯缺血和缺血/缺氧处理因素下,HepG2自噬在荧光强度和Beclin 1基因水平分别比空白对照组增强约3.2倍和3.5倍。细胞成活率分别比空白对照组增加了约20%和30%。SAMe对HepG2细胞具有显著的抑制作用,这种抑制作用在缺血/缺氧环境中更加明显,SAMe单独处理组和SAMe预处理结合缺血/缺氧组,其细胞成活率与空白对照组相比分别下降了约30%和70%。随着细胞成活率下降,细胞凋亡比例相应增加,与空白对照组相比,细胞经SAMe处理后凋亡比例增加约18%;细胞经SAMe预处理后再予以缺血/缺氧,凋亡比例增加约30%。结论:在SAMe抑制HepG2细胞生长过程中,自噬起着重要作用。  相似文献   

3.
目的:研究化疗药物索拉菲尼(Sorafenib)对肝癌细胞HepG2自噬的作用及自噬与细胞增殖、细胞凋r_的关系。方法:常规细胞培养,以10μmol/L的索拉菲尼作用不同时间,采用MDC染色,在荧光显微镜下观察自噬泡的情况:用Western印迹检测自噬相关蛋白LC3的动态变化;用3-MA抑制肝癌细胞中自噬的表达,并用CCK8法检测索拉菲尼及其联合3-MA对细胞生存率的影响,用AnnexinV/PI流式细胞仪检测抑制自噬后凋亡的变化。结果:HepG2经索拉菲尼作用后,自噬泡明显减少,LC3蛋白尤其是LC3-Ⅱ随着作用时间延长逐渐减弱;索拉菲尼联合3-MA可进一步抑制HepG2细胞中自噬的表达,抑制自噬后细胞死亡明显增加,特别是细胞凋亡明显增加。结论:索拉菲尼抗肝癌作用可能与抑制肝癌细胞自噬有关。  相似文献   

4.
目的:研究他克莫司(tacrolimus ,FK506)在体外对肝癌肿瘤株HepG2和乙肝相关肝癌株HepG2.2.15增殖的影响。方法:体外培养肝癌细胞HepG2和HepG2.2.15,采用MTT法、流式细胞技术,分别检测细胞增殖、细胞周期、CyclinA。结果:FK506可以显著抑制HepG2和HepG2.2.15细胞增殖,其抑制增殖作用随剂量增加而增强;FK506诱导细胞产生G0/G1期阻滞,这种抑制作用有浓度依赖性;FK506对周期蛋白CyclinA表达的影响呈浓度负相关性,FK506浓度越高,周期蛋白CyclinA表达越少。结论:FK506可以抑制肝癌细胞HepG2和乙肝相关肝癌细胞HepG2.2.15的增殖,这种作用可能与诱导细胞周期阻滞有关。  相似文献   

5.
索拉非尼抑制肝癌细胞增殖中自噬的作用及其机制   总被引:1,自引:0,他引:1  
目的:研究分子靶向药物索拉非尼在体外对人肝癌细胞株HepG_2增殖抑制过程中自噬的表达及作用,并探讨其可能机制。方法:以吖啶橙染色荧光显微镜对自噬进行定性观察;cell counting kit-8检测活性氧(reactiveoxygen species,ROS)抑制前后HepG_2细胞成活率的变化;RT-PCR检测自噬基因Beclin-1表达的变化。Western印迹检测自噬相关蛋白Beclin-1的变化:荧光分光光度计检测胞内二氯荧光素DCF的荧光强度。结果:索拉非尼对肝癌细胞HepG_2具有显著的抑制作用;索拉非尼可诱导肝癌细胞HepG_2产生自噬及ROS,自噬在基因及蛋白水平表达均增加;抑制ROS的产生可减少索拉非尼诱导的肝癌细胞HepG_2自噬的表达量,自噬的抑制增强了索拉非尼对肝癌细胞的抑制作用。结论:ROS参与索拉非尼诱导肝癌细胞HepG_2的自噬表达,索拉非尼在抑制肝癌细胞自噬过程中自噬可能起到保护作用,抑制自噬可能为提高进展期肝癌病人索拉非尼分子靶向治疗敏感性提供新的思路。  相似文献   

6.
目的研究不同浓度白藜芦醇(RSV)对破骨细胞分化的影响及自噬在其中的作用。方法RANKL诱导RAW264.7细胞分化过程中,加入不同浓度(0、0.1、0.5、1、5及10μmol/L)RSV,CCK-8检测干预后12、24、48、72 h时的细胞活力;TRAP染色观察破骨细胞分化程度。加或不加入3-甲基嘌呤(3-MA)抑制自噬,RT-PCR检测破骨分化相关标志物TRAP、MMP-9、CTSK和自噬相关标志物LC3、Beclin-1、P62的mRNA表达情况;Western blot检测自噬相关蛋白LC3II/I、Beclin-1、P62的表达情况。结果RANKL诱导分化过程中,细胞增殖活力提高,加入0.1~10μmol/L的RSV,细胞活力先上升后下降,在0.5μmol/L时达到最大;0.1μmol/L和0.5μmol/L的RSV能提高TRAP染色阳性的破骨细胞数和TRAP、MMP-9、CTSK、LC3、Beclin-1、P62的mRNA表达,自噬相关蛋白LC3II/I和Beclin-1也增加,P62的蛋白表达则减少;而1~10μmol/L RSV随浓度升高相关mRNA及蛋白LC3II/I和Beclin-1的表达减少,P62的蛋白表达增加;加入3-MA后,相关mRNA及蛋白LC3II/I和Beclin-1的表达减少,P62的蛋白表达增加。结论RSV浓度在0.1~10μmol/L范围内,破骨细胞分化和自噬水平先升高后降低,抑制自噬可以抑制破骨细胞的分化。白藜芦醇影响破骨细胞分化可能部分是通过调节自噬发挥作用。  相似文献   

7.
目的探讨缺氧环境下人肝癌细胞中多药耐药相关基因和缺氧诱导因子1a(HIF-1a)的表达和意义,从而部分阐明肝细胞癌发生多药耐药的机制,为逆转肝癌耐药提供新的分子靶点。方法将人肝癌细胞系HepG2细胞分别行不同时间低氧培养和转染HIF-1a/PCDNA3质粒;应用荧光定量聚合酶链反应技术和蛋白免疫印迹技术分别检测每组HepG2细胞中多药耐药相关基因(mdr1)、多药耐药相关蛋白1(MRP1)和肺耐药相关蛋白(LRP)在mRNA和蛋白水平的表达。结果在缺氧组,随着缺氧时间的延长HepG2细胞中多药耐药相关基因mdr1、MRP1和LRP的表达均逐渐增高,且以MRP1变化更为显著;而且这些多药耐药相关基因的表达升高与缺氧诱导因子-1a的表达呈同步化改变。在HIF-1a/PCDNA3质粒转染细胞中这些多药耐药相关基因的表达亦明显升高。结论缺氧可通过核转录因子HIF-1a上调肝癌细胞内mdr1,LRP、MRP1等多药耐药相关基因的表达,从而使肝细胞癌获得多药耐药性。生长局部微环境的缺氧是诱导肝癌产生多药耐药性的重要原因之一。核转录因子HIF-1a和这些多药耐药相关基因将可能成为逆转肝癌耐药的新的分子靶点。  相似文献   

8.

目的:探讨自噬抑制剂3-甲基腺嘌呤(3-MA)对人大肠癌SW480细胞生长与Notch1蛋白表达的影响。方法:将3-MA(5 mmol/L)作用于SW480细胞24 h后(以培养相同时间无处理的SW480细胞为对照),分别免疫组化和Western blot法检测细胞Notch1蛋白的表达,用CCK-8法和Annexin/PI双染法检测细胞增殖与凋亡。结果:免疫组化与Western blot结果均显示,3-MA作用后,SW480细胞Notch1蛋白的表达明显下调(均P<0.05);增殖与凋亡检测结果显示,3-MA作用后,SW480细胞增殖率明显降低,而凋亡率明显增加(均P<0.05)。结论: 3-MA能抑制结直肠癌细胞的增殖并促进其凋亡,该作用可能与3-MA抑制Notch1蛋白表达从而改变细胞自噬水平有关。

  相似文献   

9.
目的观察自噬对肝卵圆细(hepatic oval cell,HOC)在缺血缺氧微环境中增殖的影响。方法体外培养肝卵圆细胞建立缺血缺氧模型,检测缺血缺氧0、2、4、8和24 h的自噬情况,每个时间点设置单纯缺血缺氧组(ischemia-hypoxia),缺血缺氧+氯喹组(ischemia-hypoxia+CQ),正常对照组(control)。以CCK-8法检测各组HOC增殖能力的变化;Hoechst 33258染色观察细胞凋亡;应用丹(磺)酰戊二胺(Monodansylcadaverine,MDC)染色荧光定位法、免疫荧光细胞化学染色法观察各组细胞的自噬,免疫印迹法(Western blotting)检测各组细胞LC3-II/I蛋白表达情况。结果缺血缺氧对肝卵圆细胞的增殖有抑制作用,且缺血缺氧时间越长抑制越明显。与对照组相比,随着缺血缺氧的时间的延长,MDC染色阳性细胞数,细胞免疫荧光强度和自噬特异标记分子LC3 II水平及LC3-II与LC3-I的比值显著增加(P0.05)。加入自噬抑制剂CQ后肝卵圆细胞在缺血缺氧微环境中的存活率与未加CQ比较显著下降(P0.05)。结论缺血缺氧可以抑制肝卵圆细胞增殖,并且可诱导肝卵圆细胞自噬;自噬有利于肝卵圆细胞在缺血缺氧微环境中稳定细胞内环境,维持细胞的存活。  相似文献   

10.
目的研究自噬特异性抑制剂3-甲基腺嘌呤(3-MA)对5-氟尿嘧啶(5-FU)诱导肝癌细胞系SMMC7721凋亡的影响,并初步探讨其机制。方法利用单丹(磺)酰戊二胺(MDC)染色技术,在荧光显微镜下对细胞自噬进行定性观察;以CCK8法检测3-MA抑制细胞自噬前后经5-FU诱导SMMC7721细胞的存活,凋亡以AnnexinⅤ/PI流式细胞分析法检测;以Western blot法分别检测自噬特异性蛋白LC3及凋亡蛋白caspase-3活化片段和PARP裂解片段的表达。结果 5-FU处理肝癌SMMC7721细胞48 h后,可诱导其发生自噬,细胞存活率为(60.73±2.65)%,凋亡率为(40.42±2.34)%;联合应用3-MA处理48 h后,可使肝癌SMMC7721细胞存活率明显降低(P〈0.01),为(42.31±1.32)%,而细胞凋亡率显著增加(P〈0.01),为(60.92±2.99)%,同时引起自噬特异性蛋白LC3-Ⅱ及凋亡蛋白caspase-3活化片段和PARP裂解片段表达增加,其灰度值比较差异均有统计学意义(均P〈0.01)。结论自噬在5-FU诱导肝癌细胞系SMMC7721凋亡过程中起保护性作用,抑制自噬可提高肝癌SMMC7721细胞对5-FU的敏感性,其可能主要通过激活caspase-3及剪切PARP来实现的。因此,自噬特异性抑制剂3-MA可能为提高肝癌对5-FU的敏感性提供新思路。  相似文献   

11.
Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI2) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI2), TXB2 (stabile metabolite of thromboxane A2) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI2 release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB2 (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI2 release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A2, presumably contributing to hemodynamic stability within 30 min after MT.  相似文献   

12.
Don Dame 《Artificial organs》1996,20(5):613-617
Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.  相似文献   

13.
Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.  相似文献   

14.
Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H2O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg−1 followed by 0.15 mg · kg−1 · h−1, n=8) or verapamil (0.1 mg · kg−1 followed by 0.3 mg · kg−1 · h−1, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.  相似文献   

15.
Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.  相似文献   

16.
Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.  相似文献   

17.
Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg?1 i. v. or midazolam 0.05 mg · kg?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg?1 i. v. and 32 μg · kg?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg?1. The mean ED50s, calculated from dose-response curves, were 5.4 mg · kg?1, 3.9 μg · kg?1 and 0.4 mg · kg?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg?1 i. v. or midazolam 0.05 mg · kg?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg?1 and 8 μg · kg?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.  相似文献   

18.
Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg?1 · min?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min?1 · m?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO2I) and oxygen consumption index (VO2I) were also significantly increased in the dopexamine group (DO2I: from 416±91 to 717±110 ml/m2 · m2; VO2I: from 98±25 to 157±22 ml/m2 · m2), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.  相似文献   

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Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.  相似文献   

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