首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
[Objective]To research the apoptosis of hepatoma cells HepG-2 induced by shikimic acid from FRUCTUS ANISI STELLATI and its mechanism. [Methods]Hepatoma cells HepG-2 at logarithmic phase were randomly divided into drug group and control group. Shikimic acids from FRUCTUS ANISI STELLATI at the concentrations of 0. 125,0. 5 and 1 g /L were used. Inhibitory effects of shikimic acids on HepG-2 cell proliferation were detected by MTT method. Effects of shikimic acids at the concentrations of 0. 125,0. 5 and 1 g /L on the cell cycle of hepatoma cells HepG were researched by Flow Cytometer. Expression of Bcl-2 and Bax proteins were detected by immunocytochemistry detection. [Results]Results of MTT test showed that shikimic acid(0. 125,0. 5 and 1 g /L) had significant inhibitory effects on the proliferation of in vitro human liver cancer HepG-2 in a time-and dose-dependent relationship(P 0. 05). Shikimic acid blocked the hepatoma cells HepG-2 at G1 phase,so that the cells could not enter into S phase for DNA synthesis,which restricted the cell proliferation. Results of immunocytochemistry detection showed that protein expression of Bcl-2 decreased significantly,while Bax expression enhanced significantly,so that the proportion of Bcl-2 to Bax reduced. [Conclusions]shikimic acid blocked the hepatoma cells HepG-2 at G1 phase,and had significant inhibitory effects on the proliferation of human hepatoma cell through reducing the proportion of Bcl-2 to Bax.  相似文献   

2.
[Objective]To observe the protective effects and pathway of paeoniflorin on rat MID(multi-infarct dementia) model by establishing the improved MID model,and to lay the pharmacological basis for the development of protective neurons candidate compounds. [Methods]The classic rats' MID model was used to observe the protective effects and pathway of different dosages of paeoniflorin. The learning and memory abilities of rats were detected by Morris water maze. The expression of Bcl-2 and Bax protein were detected by immunohistochemistry.The changes of cerebral cortex and the neuron structure were detected by HE staining and electron microscopy. [Results]Paeoniflorin had significant improvement effects on the time of anesthetic awareness,detention time of inclined plate test,behavioral evaluation,cognitive impairment and brain neuron injury of rat MID model. The protective mechanism of paeoniflorin was related to the Bcl-2 and Bax expression in cerebral cortex and hippocampus brain tissue. [Conclusions]The paeoniflorin had significant improvement effects on the rat MID model. It restricted the EAA damage,intracellular calcium overload,and Bax expression,so as to promote the Bcl-2 expression and to restrict the cell apoptosis.  相似文献   

3.
Under a certain electric field strength of steep pulse, plenty of micropores occur in the cell membrane. The number and diameter of micropore increase rapidly with the increase of electric field strength, the membrane breaks and the cell dies at last. This phenomenon is called as irreversible electrical breakdown (IREB). To research IREB of tumor cell, integrated with power electronics and conventional high voltage pulse generator, an energy-controllable steep pulse apparatus for tumor treatment is developed. The peak value, width, frequency and rise time of the output pulse can be adjusted independently, so the energy of the output pulse can be easily controlled. The apparatus is applied in cell experiment after a detailed analysis of its operating principle and debugging in laboratory. The experiment results show that the device works steadily and satisfies the demand of medical experiment.  相似文献   

4.
拟探讨热应激诱导LLC-PK1细胞线粒体凋亡相关因子的表达和活性情况,以及激活线粒体凋亡通路的时间。采用qRT-PCR方法和Caspase活性检测试剂盒分别检测42℃热应激处理后0,2,4,8,16 h以及37℃培养的LLC-PK1细胞中HSP72、Bcl-2、Bax、AIF和Cyt.c的基因表达以及Caspase-9和Caspase-3的活性。结果显示,42℃热应激1 h,LLC-PK1细胞Bcl-2/Bax(P0.05)和AIF(P0.01)基因表达以及Caspase-3(P0.01)活性从0 h开始升高(P0.01),到2 h达到最高(P0.01);HSP72基因表达和Caspase-9活性0 h即达到最高(P0.01);Cyt.c基因表达在2 h开始极显著升高(P0.01),并且此时最高,8 h以后全部因子恢复到正常水平。结果表明,42℃热应激1 h即激活LLC-PK1细胞线粒体凋亡通路,且热应激后的0~8 h线粒体凋亡通路处于活化状态,其中2 h时最为活跃。  相似文献   

5.
To accurately measure the ascendant time of a high-voltage steep pulse, the pace and precision of counter is highly challenged. The authors put forward the design of high-speed count system based on CPLD and DSP. In this system, the outer crystal oscillator of CPLD act as low-frequency clock whose frequency division and phase invertion are done by D-trigger group designed with CPLD, and finally,they get the counter with 200 MHz i. e. 5ns per period by the method of frequency difference multiply. The counting pace and precision are promoted, and meet the demand to measure the ascendant time of high-voltage steep pulse. It can be extended to measure the descendant time of pulse, pulse width and periods.  相似文献   

6.
不同氧气浓度对绵羊体外受精胚胎凋亡的影响   总被引:1,自引:1,他引:0  
为了研究培养环境中的氧气浓度对绵羊体外受精胚胎发育的影响。比较了低氧环境(5%O2)和高氧环境(20%O2)中绵羊体外受精胚胎的发育能力和凋亡发生情况,同时利用Real-time PCR技术检测这两种氧气浓度下绵羊体外受精胚胎中凋亡相关基因Bax和Bcl-2的表达水平。结果表明:在这两种氧气浓度下发育的绵羊体外受精胚胎,细胞凋亡信号都起始于16-细胞期,且在胚胎各发育阶段发生凋亡的比率没有明显差异,但低氧环境组的囊胚发育率和囊胚细胞数都显著高于高氧环境组的(分别为45.9%、134;14.6%、106,P<0.05),且其囊胚细胞的凋亡指数也显著低于高氧环境组(分别为0.053、0.066,P<0.05);PCR的研究结果表明:不论是高氧环境还是低氧环境,在绵羊体外受精胚胎的各阶段都能检测到Bax和Bcl-2的表达。而且在囊胚阶段,低氧环境下的Bcl-2基因表达量明显高于高氧环境下的。低氧环境可以抑制绵羊胚胎细胞的凋亡,更有利于绵羊胚胎的发育。  相似文献   

7.
Electrochemotherapy is a new therapy on curing tumor, and it consists of two therapies, which are direct current electrochemotherapy and electric pulse aided antitumor medicine electrochemotherapy. Its widely application prospect is being taken on. Researchers home and overseas study deeply in the wide field of its cure mechanism, ways and means, animal tests and clinical application. Medical studies have shown that electrochemotherapy is an easily operated therapy with excellent curative effect and security. On the basis of these studies, a new therapy is put forward, that is, energy-controllable steep pulse therapy, electric pulse' killing effect on cell membrane is called as irreversible breakdown, and the first-stage study results of this new therapy are introduced.  相似文献   

8.
黄芪多糖(APS)拮抗铅镉联合致鸡脾脏细胞凋亡作用的研究   总被引:1,自引:1,他引:0  
为了探讨黄芪多糖注射液对铅镉联合致鸡脾脏细胞凋亡的拮抗作用。采用TUNEL法、RT-PCR和DNA ladder方法检测分别对对照组、铅镉组和黄芪多糖-铅镉组的鸡脾细胞凋亡率和脾淋巴细胞凋亡基因Bcl-2 mRNA转录水平。结果表明:与对照组比较,试验组的细胞凋亡率明显升高,Bcl-2mRNA表达水平降低;试验组和对照组差异显著或差异极显著,并且黄芪多糖-铅镉组数据介于对照组和铅镉组之间。试验结果显示:黄芪多糖注射液对铅镉联合致鸡脏脾细胞凋亡具有明显的拮抗作用。  相似文献   

9.
为解决青藏高原东部强降温的气象预报和服务问题,利用青藏高原东北部68个气象站1961-2017年逐日最低气温数据,辅以趋势分析及相关分析等方法,本文探讨了近57年青藏高原东北部强降温的阈值及气候特征,并利用NECP/NCAR(2.5°×2.5°)海温场、高度场建立了预报诊断模型。研究发现 (1) 应用改进的强降温指标统计寒潮发生的特征更符合高原实际情况。(2)受地形地貌及山脉阻挡的影响,青藏高原东部强降温次数的地域分布存在明显差异,海拔较高的山区和东部地区强降温次数明显多于盆地。南部山区24h寒潮发生的次数多于48h、72h。(3)近57年区域寒潮频次总体呈下降趋势,南部和北部的降速分别为-0.5次/10a、-0.4次/10a,并通过显著性检验;西北部盆地区降速分别为-0.1次/10a,未通过显著性检验。(4)高冷空气的移动路径是强降温预测的关键信号。研究结果为青藏高原相关部门开展农牧业资源的和旅游资源的相关决策服务提供科学依据。  相似文献   

10.
为了提高牛体细胞克隆的效率,比较了不同融合电压对核移植胚发育的影响,其中1.7kv/cm电场强度,获得了较高的融合率、卵裂率和囊胚率,分别为67.14%,76.59%和29.16%。比较了血清饥饿处理体细胞对核移植效率的影响,血清饥饿处理体细胞后,融合率、卵裂率和囊胚率分别为68.91%,74.79%和28.26%,与非血清饥饿处理的相比没有明显差异(分别为60.96%,71.91%和20.31%,P>0.05)。而且胚胎移植后的怀孕率和产犊率也没有差异(分别为29.17%,8.33%和33.33%,16.66%,P>0.05)。另外,通过加强克隆牛的产后护理,可以提高克隆牛的成活率。总之,优化生产克隆牛的各环节因素,可以从整体上提高克隆牛的生产效率。  相似文献   

11.
钱颖  彭永康 《华北农学报》1994,9(4):116-118
500mg/kg苯黄隆对小鼠精子畸型率的影响低于对照,1000mg/kg引起的精子畸型率接近对照,而2000mg/kg下则比对照组高出0.5倍。上述3种剂量浓度对胃中的乳酸脱氢酶(LDH)工功酶未产生影响,但在解毒器官肝脏中LDH同功酶活性高于对照。结果表明,苯黄隆属低毒农药,然而潜在危险性尚性存在,使用时需掌握合适浓度。  相似文献   

12.
板蓝根粗多糖对免疫抑制小鼠的免疫调节作用   总被引:1,自引:0,他引:1  
将试验小鼠分为对照、模型和剂量(低、中、高)组,建立免疫抑制模型。对照组、模型组饲喂基础饲料,剂量组分别饲喂含不同板蓝根粗多糖的饲料。6周后测小鼠血常规指标、脏/体比、血清白介素-2(IL-2)及肿瘤坏死因子-α(TNF-α)的含量。结果表明,免疫抑制小鼠的白/红细胞数、血小板数和血红蛋白值均随粗多糖剂量的增加而增大;体增质量对照组最大,低、中、高剂量组和模型组依次递减;各剂量组脏/体比均明显小于对照组;各剂量组小鼠血清中IL-2和TNF-α水平均显著上升。说明板蓝根粗多糖能提升小鼠免疫功能,但对小鼠的发育有一定影响。  相似文献   

13.
The basic characteristic of electric field is that the substance in the field is in operation by the stress. Under steep pulsed electric fields, there is strong distribution of electric fields on the inside and outside surfaces of cell membrane. In virtue of the difference of the permittivity among membrane, cytoplasm and extracellular medium, there must be the electric field stress on the surface of the membrane. The calculation results showe that cell membrane is stressed from two directions of cytoplasm and extracellular medium under external electric fields. The stress on tumor cell membrane is greatly larger than normal cell membrane, so the tumor cell is more sensitive than normal cell. Tumor cell membrane certainly will be destroyed by electric field stress, then its survival environment and germ plasm will be injured and accordingly the cell will be damaged.  相似文献   

14.
桐花树果实乙酸乙酯部位体外抗氧化活性研究   总被引:1,自引:1,他引:0  
为了研究桐花树果实乙酸乙酯部位的抗氧化作用,考察了乙酸乙酯部位对DPPH自由基,羟自由基的清除效果,测定了其总还原力以及对H2O2诱导小鼠氧化溶血和对小鼠肝匀浆MDA生成的抑制作用。结果表明:桐花树果实乙酸乙酯部位对DPPH自由基和羟自由基的清除率随着样液质量浓度的增加而升高。0.01、0.05、0.1 mg/mL桐花树果实乙酸乙酯部位对H2O2对小鼠红细胞溶血抑制的抑制率分别为47.64%、67.09%、81.99%。与阴性对照组相比,0.5~2.0 mg/mL桐花树果实提取物均可极显著地抑制小鼠肝匀浆自发的产生MDA(P<0.01)。可见,桐花树果实乙酸乙酯部位具有明显的抗氧化活性。  相似文献   

15.
In need of ultra-high frequency partial discharge location and correction of electrical equipment, we designed a sub-nanosecond steep pulse generator, and constructed the corresponding circuit model through the circuit simulation software Pspice. The influence of the storage capacitor and the supply voltage to the pulse waveform is analyzed. When the storage capacitor is 10 pF and 20pF respectively, the output pulse waveforms have been measured in the conditions of pulse rise time being 0.68 ns and 0.90 ns, pulse width being 0.98 ns and 1.18 ns, pulse peek being 8.72 V and 12.2 V respectively, and partical discharge capacity of charge being 320 pC and 600 pC. The picked multi-pulse singnals are steady with the developped sleeve monopole antenna, the error is less than 70 ps. It can be used for the experimental study of ultra-high frequency partial discharge location and correction of electrical equipment.  相似文献   

16.
用实时荧光定量PCR技术对草地贪夜蛾Spodoptera frugiperda卵巢组织细胞蛋白磷酸酶2A (protein phosphatase 2A,PP2A)基因表达进行分析以研究斑蝥素对其表达的影响。结果表明,PP2A相对表达量与斑蝥素浓度存在不显著的负相关性,斑蝥素各浓度下PP2A相对表达量差异都不显著(P<0.05),处理24 h后对照的极显著高于用斑蝥素处理的(P<0.01)。在相同斑蝥素浓度下,除25μg/mL外其他浓度处理24 h后PP2A相对定量显著高于6 h的(P<0.05)。研究结果说明,斑蝥素处理对卵巢细胞内的PP2A基因相对表达量有一定的影响,且与斑蝥素的浓度和处理时间有一定关系。  相似文献   

17.
以小鼠急性肝脏氧化损伤为模型,通过采用不同浓度的丙酮对小鼠肝脏蛋白进行分级提取和沉淀,用SDS-聚丙烯酰胺连续密度梯度凝胶电泳(SDS-PAGE)试验寻找差异表达蛋白质。通过试验发现,模型组中水溶性总蛋白、非水溶性总蛋白和膜蛋白总体表达量较空白组均有明显降低,进而对水溶性总蛋白进行的分级提取试验中发现有2个蛋白条带具有显著的差异性。进一步以基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)检测差异蛋白的肽质量指纹,在蛋白质数据库中检索鉴定差异蛋白的种类,经鉴定两种差异蛋白分别为一种未命名蛋白和Cu/Zn超氧化物歧化酶(Cu/Zn superoxide dismutase),为进一步研究其损伤机理奠定基础。通过分级提取蛋白质样品的试验方法,降低了蛋白组学当中蛋白质分离的成本和技术难度,在保证蛋白纯度的同时提高了电泳的分辨率,电泳图中的条带清晰、分明,便于后期进行质谱分析,同时也为蛋白质组学的应用提供了一种新思路和新方法。  相似文献   

18.
Herschel-Bulkley model is used to describe rheological behavior of the Magnetorheological (MR) fluids subject to an applied magnetic field. Based on momentum equation, the effect of the applied magnetic field on the pressure driven flow of the MR fluids in the cylindrical pipe is analyzed theoretically. The expressions for the velocity and the volumetric flow rate in viscoplastic flow are derived to provide a theoretical foundation for the design of cylindrical pipe MR devices. The results indicate the MR fluids have the properties of both viscosity and viscoplasticity. The flow of the MR fluids in the cylindrical pipe exhibits viscoplastic flow behavior. The velocity exhibits the distributions of both parabolic curve and straight line with the magnetic field direction. The volumetric flow rate can be continuously adjusted by an external magnetic field.  相似文献   

19.
In order to resolve the hazard of biofouling and scale in circulating cooling water system of power stations, this paper takes the lead in combining high voltage pulses and high frequency pulses for sterilization and descaling process. It analyzes both electromagnetic effects and biochemical effects on sterilizing and descaling process caused by the high voltage pulses and high frequency pulses respectively. The pulse generator is designed according to the requirements of electromagnetic parameters for effective operation. The design and improvement of process chambers are assisted by electromagnetic field simulation technology. Experimental data prove that the system can output high voltage pulse whose maximum peak value reaches 7 kV and high frequency pulse whose maximum peak value reaches 100 V the frequency ranges from 500 kHz to 2 MHz. The rate of sterilization can be as high as 91,and the rate of descaling reaches 71. This system is expected to achieve the standards of industrial water treatment through further research.  相似文献   

20.
在水稻转基因材料后代中筛选到一个自交后代标记基因呈1:1异常分离的雄配子不育突变体(暂命名为Male gametophyte abortion1,mga1(t))。该突变体花粉约50%败育,花粉败育表型与T-DNA共分离,且只能通过雌配子传递,表明mga1(t)是一个T-DNA插入引起的雄配子败育突变体。Southern blot分析表明,mga1(t)为单拷贝T-DNA插入突变体。侧翼序列分析发现T-DNA插入在水稻3号染色体上一个Bax inhibitor(BI)-1 like家族蛋白基因的5’非翻译区,该基因可能与细胞程序性死亡有关。RT-PCR表达分析显示MGA1(t)基因在水稻不同生长发育期均有表达,尤其在长度发育为0~7mm的颖花中强表达,表明该基因是一个水稻雄配子优势表达基因。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号