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 62 毫秒
1.
目的:研究鲤鱼精巢DNA对自由基的清除作用。方法:采用 化学发光法测定鲤鱼精巢DNA对Cu2 -Vit C-H2O2发光体系产生的·OH自由 基的清 除作用,采用分光光度法检测鲤鱼精巢DNA对大鼠腹腔多形核白细胞(PMNs)呼吸爆发产生O ÷2自由基的清除作用,采用电子自旋共振(ESR)法测定鲤鱼精巢DNA对DPPH有机自由基的 清 除作用。结果:鲤鱼精巢DNA使Cu2 -Vit C-H2O2发光体系的发光计数率降低, 使 PMNs呼吸爆发产生O÷2自由基的数量减少,使DPPH的特征波峰逐渐降低直至消失。结论 :鲤鱼精巢DNA对·OH自由基、O÷2自由基和有机自由基均有显著的消除作用。  相似文献   

2.
羟自由基引发的DNA氧化损伤机理的研究进展   总被引:2,自引:0,他引:2  
近年来 ,有关活性氧的产生及其对生物分子的损伤机理研究受到各学科的普遍重视 ,许多疾病与活性氧的介入有密切关系 [1 ] ,尤其是羟自由基 (OH· )。作为最活泼的活性氧自由基并没有专门的清除酶 ,它与任何生物分子都以极快的反应速率发生反应 ,而 H2 O2 及 O- 2· 。等的反应活性与 OH· 相比不是很高 ,对生物体的损伤很可能是通过与金属离子如铁、铜反应形成 OH·而起作用 ,因此 OH·可能是对生物体危害最大的氧自由基 [2 ]。大多数生物分子与分子氧作用产生活性氧自由基的反应速度在无金属离子参与时是非常缓慢的 ,金属离子 (如铁、…  相似文献   

3.
以正常大鼠组织匀浆、线粒体为材料研究穿心草酮 (1,6 -二羟基 - 3,5 -二甲氧基酮 ,CanscoraXanthon,CX)抗脂质过氧化作用。以丙二醛 (MDA)为指标 ,观察 CX对组织匀浆、线粒体体外脂质过氧化产物 MDA生成量的影响。以吸光度 (A)值为指标 ,观察 CX对邻苯三酚自氧化产生的 O÷2 及 Cu2 - Vit C自由基产生系统产生的· OH的清除作用。结果 CX抑制正常大鼠脑、肝、心、肾匀浆的体外过氧化脂质生成 ,抑制Vit C和 Fe SO4激发的线粒体膨胀。提示 CX能清除 O÷2 ,· OH。  相似文献   

4.
目的评价3种黄酮类同系化合物槲皮素及其单糖苷异槲皮素和双糖苷芦丁的体外抗自由基作用,进一步研究其构效关系。方法采用H2O2/Fe2 体系,通过Fenton反应生成羟自由基(·OH);采用邻苯三酚自氧化法产生超氧阴离子(O2-)。利用·OH造成肝细胞脂质过氧化以及红细胞膜破裂,观察受试化合物的保护作用,并计算IC50。结果在以上4种体外模型中,3种药物均表现出极强的清除自由基能力。在·OH以及O2-清除实验中,抗氧化活性顺序为芦丁>异槲皮素>槲皮素;在抑制肝匀浆脂质过氧化及红细胞膜破裂实验中,抗氧化活性顺序为槲皮素>异槲皮素>芦丁。结论3种受试黄酮类化合物均具有十分强大的自由基清除作用,且呈现明显的剂量依赖性和糖基结构依赖性,在不同的实验体系中其抗自由基活性强弱顺序不同。  相似文献   

5.
目的 评价鼠尾藻和海黍子两种褐藻中高相对分子质量褐藻多酚的抗氧化活性。方法 分别利用 3种体系 ,通过对羟自由基 (· OH)、超氧阴离子 ( O÷2 )和 1,1-二苯基 - 2 -苦味肼基自由基 ( DPPH· )清除效率来评价其抗氧化活性。结果 两种褐藻中高相对分子质量褐藻多酚对· OH、O÷2 和 DPPH·均有很高的清除效率 ,且效果相近。结论 鼠尾藻和海黍子两种褐藻中高相对分子质量褐藻多酚具有较强的抗氧化活性 ,是一类潜在的海洋生物天然抗氧化剂。  相似文献   

6.
目的 研究射干 Belamcanda chinensis中分离的 4种异黄酮类成分清除 O2 ÷ ,· OH和 H2 O2 自由基的能力。方法 采用生物化学发光法测定。结果 射干根茎中分离得到的异黄酮成分野鸢尾苷元 (irgenin, ) ,鸢尾苷元 (tectorigenin, ) ,鸢尾苷 (tectoridin ) ,5 ,6 ,7,4′-四羟基 - 8-甲氧基异黄酮 (5 ,6 ,7,4′- tetrahydroxy- 8- men-thoxyisoflavone, )均具有清除自由基的作用 ,其中鸢尾苷元对 O2 ÷ ,· OH和 H2 O2 氧自由基清除作用的能力最强。结论 射干根茎中的 4种异黄酮类成分具有清除自由基的作用。  相似文献   

7.
采用正交试验研究了Cu2+、Zn2+、Mn2+单独作用或共存时中和铁氧体法净化低浓度Co2+废水的工艺。中和铁氧体法对Co2+、Cu2+、Zn2+、Mn2+4种离子去除效果较好,Cu2+、Zn2+、Mn2+单独作用或共存均不同程度降低了Co2+的去除效果。在各最优组合条件下,Co2+净化系数均高于1.00×104,残留质量浓度为0.40~0.50 μg/L;Cu2+、Zn2+、Mn2+的残留质量浓度均低于5 μg/L。Cu2+、Zn2+、Mn2+单独作用时各离子净化系数从大到小依次为Co2+ > Mn2+ > Cu2+ > Zn2+,离子共存时各离子净化系数从大到小依次为Co2+ > Cu2+ > Mn2+ > Zn2+,共存离子之间相互作用对铁氧体的形成具有影响。  相似文献   

8.
目的研究白藜芦醇苷的清除自由基、抗氧化活性.方法以NADH-PMS-NBT系统产生氧自由基O 2-;EDTANa2-Fe(Ⅱ)-H2O2系统和Fe2++Vit C系统产生羟自由基(·OH);H2O2诱导大鼠红细胞氧化溶血来研究白藜芦醇苷的生物活性.结果白藜芦醇苷体外可清除O2-及·OH;抑制H2O2诱导的大鼠红细胞氧化性溶血;抑制·OH引起的小鼠肝微粒体过氧化脂质(LPO)和大鼠红细胞膜丙二醛(MDA)含量的升高.结论白藜芦醇苷具清除自由基及抗脂质过氧化的作用.  相似文献   

9.
以NADH-PMS-NBT体系产生超氧阴离子自由基(o2-·)和EDTANa2·Fe(Ⅱ)-H2O2体系产生 羟自由基(·OH)来研究壳聚糖Cu(Ⅱ)、Zn(Ⅱ)配合物、羧甲基壳聚糖Cu(Ⅱ)、Zn(Ⅱ)配合物时氧自由基的 清除作用。结果显示配合物对O2-·和·OH均具有明显的清除作用,其中铜(Ⅱ)配合物对O2-·的清除活 性最高,而锌(Ⅱ)配合物比铜(Ⅱ)配合物具有更强的清除·OH的能力,羧甲基壳聚糖Cu(Ⅱ)、Zn(Ⅱ)配合 物与含有相同金属离子的壳聚糖配合物相比对O2-·和·OH具有更高的抑制活性。  相似文献   

10.
以正常大鼠组织匀浆、线粒体为材料研究穿心草(口山)酮(1,6-二羟基-3,5-二甲氧基(口山)酮,Canscora Xanthon, CX)抗脂质过氧化作用.以丙二醛(MDA)为指标,观察CX对组织匀浆、线粒体体外脂质过氧化产物MDA生成量的影响.以吸光度(A)值为指标,观察CX对邻苯三酚自氧化产生的O÷2及Cu2+-Vit C自由基产生系统产生的·OH的清除作用.结果CX抑制正常大鼠脑、肝、心、肾匀浆的体外过氧化脂质生成,抑制Vit C和FeSO4激发的线粒体膨胀.提示CX能清除O÷2,·OH.  相似文献   

11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

12.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

13.
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.  相似文献   

14.
FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…  相似文献   

15.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.  相似文献   

16.
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.  相似文献   

17.
Objective:To investigate the gene expression of osteoprotegerin(OPG) and osteoclast differentiation factor(ODF) in the bone tissue of patients with hip fracture due to osteoporosis. Methods:OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers(over 50 years old) with hip fracture(Observer Group) and 30 cases of hip facture sufferers with no osteoporosis(Control group) were analyzed with the Semi-Quantitative RT-PCR method. Results:The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion:Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.  相似文献   

18.
Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.  相似文献   

19.
Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.  相似文献   

20.
Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.  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