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 515 毫秒
1.
目的: 设计合成血管内皮生长因子多位点核酶,探讨其对靶RNA的切割作用.方法: 利用计算机辅助设计针对VEGF165的3个单位点核酶 (Rz1, Rz2, Rz3) 和联合型多位点核酶 (Rz123),构建其自剪切转录载体,观察多位点核酶对靶RNA的切割作用.结果: 构建的多位点核酶自剪切转录载体在体外转录中,顺式核酶发生了自身剪切,并释放出正确的目的核酶,多位点核酶可切割靶RNA,且效率高于单一核酶,其切割效率分别为 (37±10)% (Rz1), (51±8)% (Rz2 ), (68±15)% (Rz3) 和(88±11)% (Rz123).结论: 抗血管内皮生长因子多位点核酶体外可联合切割靶RNA,具有较高的生物活性.  相似文献   

2.
目的:构建特异性切割人组织金属蛋白酶抑制剂1(tissue inhibitor of metalloproteinases1,TIMP-1)的锤头状核酶的真核表达载体并在体外进行活性鉴定,为应用于瘢痕基因治疗奠定基础.方法:设计并合成针对人组织TIMP-1 mRNA的锤头状核酶基因Rz182、Rz358和Rz412及相应的点突变核酶基因,将核酶基因克隆于可在体内高表达核酶的载体pBSKneoU6中,制备嵌合于U6 snRNA分子的核酶基因克隆.逆转录聚合酶链式反应获得全长TIMP-1 mRNA基因片段并克隆至T载体.体外转录法大量制备以α-32P UTP 标记的核酶及靶RNA,进行体外切割实验.结果:核酶基因克隆制备正确,在体外成功转录出嵌合于U6 snRNA的核酶和靶RNA. 37℃的生理温度下,U6Rz182和U6Rz358成功切割了靶RNA,U6Rz182切割效率为49.23%,Km=29.7 nmol/L,Kcat=0.32 min-1.U6Rz358切割效率为55.21%.Km=39.6 nmol/L,Kcat=0.21 min-1.U6Rz412及突变核酶均未显示切割活性.结论:本研究中制备的U6Rz182和U6Rz358有良好的特异催化切割活性,有望在瘢痕成纤维细胞内抑制人TIMP-1的表达,成为新的抗瘢痕核酸药物.  相似文献   

3.
目的:探讨多位点核酶对乙型肝炎病毒(HBV)信使核糖核酸(mRNA)的切割作用,以及保守碱基突变后对切割活性的影响。方法:利用计算机辅助设计针对HBV C区基因的多位点核酶及保守碱基突变的双位点核酶,构建多位点核酶及双位点突变核酶的自剪切载体(pGEMRz123,pGEMmRz12),观察核酶及突变核酶对RNA的切割作用。结果:构建后的多位点串联核酶及突变核酶的自剪切转录载体在体外转录后,其顺式核酶可发生自剪切,并可将目的的核酶释放出来。多位点核酶对HBV mRNA有明确的切割作用,而保守碱基突变后对HBV mRNA则无切割作用。结果 :抗HBV多位点酶在体外可明确切割HBV靶RNA,突变后的核酶无切割活性,保守碱基为核酶保持活性所必需。  相似文献   

4.
王海芳  罗晓星  王立锋  扈本荃 《医学争鸣》2003,24(17):1569-1571
目的:选择针对ADAR1 mRNA的5’非编码区(NCR)和翻译起始区的锤头状核酶(ribozyrme,Rz)切割位点,构建针对ADAR1的Rz可诱导真核表达载体,旨在knock down ADAR1基因,开展ADAR1基因功能的研究.方法:应用计算机辅助设计,根据能量最低化原理,以ADAR1 mRNA的5’NCR和翻译起始区为靶序列,预测其二级结构,选择理想的Rz切割位点,设计并合成锤头状核酶.采用亚克隆法首先将人工合成的Rz DNA序列插入原核载体p1.5的XbaI和KpnI位点获得Rz原核表达质粒pRz-613;再将pRz-613中ADAR1Rz基因连同其两端的自剪切Rz序列一起克隆入可诱导真核表达载体pTRE的SacⅡ和EcoRI位点得到真核表达质粒pRz—ADAR1;通过酶切电泳和测序检查质粒重组后序列情况.结果:选出ADAR1 mRNA的第208位为Rz切点,设计并合成了RzDNA序列.所构建的pRz—ADAR1经酶切电泳鉴定显示,插入Rz序列大小约为180kb,和预期结果相同;经测序证实Rz序列正确.结论:利用计算机辅助设计,成功构建了针对ADAR1锤头状Rz可诱导真核表达载体pRz—ADAR1.  相似文献   

5.
抗乙型肝炎病毒特异联合型核酶的体外切割作用   总被引:5,自引:1,他引:4  
目的:探讨单一及多位点核酶对乙型肝炎病毒靶RNA的切割作用。方法:利用计算机辅助设计针对乙型肝炎病毒C基因的三个单一核酶及特异联合型核酶,构建三个核酶各自及三个核酶串联的自剪切转录载体(pGEMRz123)观察单一及串联核酶(Rz123)对靶RNA的切割作用。结果:构建的串联核酶自剪切转录载体体外转录后,在顺式核酶发生自剪切后可将目的核酶正确地释放出来,计算机设计的单一核酶体外可剪切靶RNA,串联  相似文献   

6.
目的 探讨体外核酶对肿瘤多药抗性相关基因mdr1靶RNA分子的切割作用及其影响因素。方法 利用计算机软件设计能特异切割mdr1 mRNA的锤头状核酶(ribozyme),并构建抗mdr1-ribozyme和靶分子的体外转录质粒,进行体外切割实验。结果 发现抗mdr1-ribozyme能较好地切割mdr1 mRNA。 结论 抗肿瘤多药抗性核酶的体外研究为其体内应用提供了参考,ribozyme有可能成为逆转肿瘤多药抗性的新药物。  相似文献   

7.
惭型肝炎病毒蛋白对核酶剪切作用的影响。方法 利用计算机辅助设计针对乙型肝炎病毒C基因的三个单一核酶构建Rz1核酶自剪切转录载体(pGEMRz1),观察单一核酶(Rz1)对靶RNA的切割作用及乙型肝炎病毒观察单一核酶(Rz1)对靶RNA的切割作用及乙型肝炎病毒蛋白对核酶剪切作用的影响。结果 核酶自剪切转录载体体2上转录后,在顺式核酶发生自剪切后可将目的核酶正确地释放出来,计算机设计的单一核酶体外可剪  相似文献   

8.
栾荣华  贾国良  李伟  贾战生  连建奇 《医学争鸣》2003,24(14):1249-1252
目的:构建c—myc基因核酶及其靶mRNA的体外转录载体,探讨核酶对靶mRNA的体外切割作用。方法:通过计算机分析c—myc基因mRNA的二级结构,设计核酶基因序列,采用DNA合成仪合成核酶基因,以克隆技术将核酶基因构建入pGEM3Zf( )体外转录载体,将大鼠c—myc基因第2外显子及部分第3外显子的基因片段克隆入pGEM7Zf(-)体外转录载体,分别进行体外转录获得核酶及靶mRNA。在含有Mg^2 的反应体系中,进行核酶对靶mRNA的体外切割反应。结果:经限制性内切酶酶切鉴定,核酶基因准确克隆入pGEM3Zf( )载体,经DNA自动序列分析仪测序分析,大鼠c—myc基因第2外显子及部分第3外显子的基因片段准确克隆入pGEM7Zf(-)载体。核酶对靶mRNA的体外切割活性约为64.5%。结论:该核酶具有切割靶mRNA的活性,可进一步用于细胞内和体内研究。  相似文献   

9.
目的:探讨per基因与阿片类成瘾的相关性,进而寻找治疗阿片成瘾的基因戒毒疗法。方法:设计并合成特异性per锤头状核酶基因和per核酶靶mRNA组分基因,并分别重组人体外转录质粒,而后将经体外转录反应得到per核酶RNA和地高辛标记的per核酶靶mRNA组分。将转录产物混合,在不同条件下进行体外切割反应后,采用地高辛化学发光法检测per核酶的体外切割效率。小鼠脑室注射直接导入脂质体包裹的重组质粒pcDNA 3.1-per RZ DNA,按剂量递增法建立吗啡依赖动物模型,用纳洛酮催瘾,观察戒断反应的变化。结果:per核酶对per核酶靶mRNA组分的体外切割效率达到60%。重组质粒组小鼠的刻板跳跃、“湿狗”样抖动和打洞次数与空质粒组、生理盐水组相比明显减少,但并不抑制小鼠的体重下降。结论:per核酶具有体外定点切割per基因mRNA组分的活性。经小鼠吗啡成瘾模型检测,该重组质粒能成功转染活体小鼠脑细胞并在脑组织内稳定表达per核酶,发挥阻断per基因表达的作用,有效地减轻吗啡成瘾的戒断症状。  相似文献   

10.
特异性切割大鼠c—myc癌基因mRNA核酶的设计   总被引:5,自引:0,他引:5  
栾荣华  连建奇 《医学争鸣》1998,19(2):228-229
核酸(ribozyme)为具有催化活性的RNA分子,能序列特异性地切割靶RNA.与传统的蛋白质酶所不同的是,核酶通过两侧的引导序列与底物以碱基互补形成杂交链,具有更高的底物特异性;核酶切割完靶RNA后即从杂交链上解离下来,可对新的靶RNA进行切割.因此,核酸成为近年来基因治疗的一种新方法.锤头状核酶具有分子小、设计简单、易于合成的特点,人们对核酸在基因治疗中作用的研究大部分是采用锤头状核酸.我们以Forster等总结的由13个保守碱基和3个螺旋区组成的锤头状核酸为模型,选择大鼠c-myc癌基因mRNA为靶RNA,在计算机辅助下设计了能特异性切割大鼠c-myc癌基因mRNA的核酸.  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.
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   

14.
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   

15.
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   

16.
Objective:To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas(SPTP). Methods:Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin(HE) staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results:Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin(9/9 cases), AAT(9/9 cases), NSE(9/9 cases), ACT(7/9 cases), CK20(2/9 cases), CgA(1/9 cases), S-100(3/gcases), PR(4/gcases), Syn(3/9 cases) and CD56(5/9cases), negative in CEA and ER. Conclusion:SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.  相似文献   

17.
In recent years, the author of this essay has applied electro-acupuncture combined with the trigger point needle-embedding for treatment of primary trigeminal neuralgia in 31 cases, yielding satis- factory results as reported in the following.  相似文献   

18.
Objective: To explore the role of matrix metalloproteinase-1,2 (MMP-1, MMP-2) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) in endometriosis. Methods: The eutopic and ectopic endometria from 40 subjects suffering from endometriosis and regular.endometria from 40 subjects (excluding endometriosis) were collected and examined by in situ hybridization technology and western blot assay. Results: Both expressions of MMP-1 and -2 were stronger in ectopic endometrium and eutopic endometrium than in normal endometrium. On the contrary, the expression of TIMP-1 in ectopic endometrium and eutopic endometrium was lower. The differences were significant (P 〈 0.01 ). Moreover, there was no relationship among the expressions of MMP-1, 2 and TIMP-1 in ectopic endometrium. Conclusion: The expressions of MMP-1, 2 and TIMP-1 lose balance and lack of periodic changes in ectopic endometrium , which explains the biological invasive behavior of endometriosis. It was suggested-that regulating the balance between the MMPs and TIMP-1 should be an ideal therapeutic target to endometriosis.  相似文献   

19.
Prof. SHI Da-zhuo, Ph.D., male, was born on March 20, 1960. Prof. SHI entered the Ph.D. program in 1990 at the China Academy of Chinese Medical Sciences under the supervision of Prof. CHEN Ke-ji, majoring in the treatment of cardiovascular diseases. After receiving his Ph.D. degree in 1993, Prof. SHI started working at the Cardiovascular Center in Xiyuan Hospital affiliated to China Academy of Chinese Medical sciences.  相似文献   

20.
《中国结合医学杂志》2008,14(2):159-159
The 6th National General Congress of Chinese Association of Integrative Medicine (CALM) was convened at 19-20, April 2008 in Beijing. Academician CHEN Zhu, the minister of Ministry of Health indicated at the congress that the integration of Chinese and Western medicine is very well in keeping with the situation of our country and the general rule of development in medical science; and as a good integration of Chinese medicine and Western medicine, it is mutually beneficial and advantageous to both of them. Seeing the creativity shown in integrative medical investigation in theoretic and methodological sides, we should and must persist in and develop it.  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