125I标记三链形成寡核苷酸对肝癌细胞生长的抑制作用

目的探讨^125I标记的三链形成寡核苷酸（TFO）对肝癌细胞的抑制作用，为HBV相关肝细胞癌（HCC）的基因治疗提供实验依据。方法合成能与HBV前S基因特异结合的TFO，并以^125 I标记（^125 I-TFO）；分^125I—TFO、等量TFO、相同活度^125 I和空白对照4组与HepG2．2．15细胞共同培养，通过ELISA法检测培养前后各组细胞上清中乙型肝炎e抗原（HBeAg）和乙型肝炎表面抗原（HBsAg）含量的变化，以四甲基偶氮唑蓝（M1Tr）比色法检测各组细胞存活率。结果^125 I-TFO标记率〉93％，稳定性较好，37℃放置12h放化纯90．8％，48h81．1％，72h73．2％；^125I-TFO组在转染48h对HepG2．2．15细胞合成HBeAg及HBsAg的抑制作用最强，对HBeAg和HBsAg表达的抑制率（74．5％和45．2％）及细胞杀伤率[72h细胞增殖抑制率为（31．64-2．5）％]高于其他实验组（P〈0．01）。结论^125 I-TFO可以抑制HBV抗原表达，杀伤肝癌细胞，为制备抗HBV、抗HCC的放射性基因治疗药物提供依据。     

雄激素受体三螺旋形成寡核苷酸抗前列腺癌细胞增殖的研究

目的　探讨反基因策略对雄激素受体(AR)表达和前列腺癌细胞增殖的影响。方法　针对AR基因2 4 4 7～2 4 6 1核苷酸序列设计并合成三螺旋形成寡核苷酸(TFO) ,经脂质体介导转染LN CaP前列腺癌细胞株,于转染后2 4、4 8、72h分别采用3H 胸腺嘧啶核苷(TdR)参入实验测定癌细胞增殖活性,用逆转录聚合酶链反应(RT PCR)方法检测ARmRNA表达,用放射配基结合分析法(RBA)单点法检测AR蛋白质表达,并与反义寡核苷酸(ASON)相比较。结果　2 4、4 8、72hTFO组LNCaP细胞的AR表达水平明显低于ASON组(P <0 0 5 ) ,TFO对LNCaP细胞增殖的抑制率显著高于ASON(P <0 0 5 )。结论　该TFO能有效抑制AR表达和前列腺癌细胞增殖,可用于反基因放射治疗的研究     

小鼠双微体扩增基因反义探针用于荷人前列腺癌裸鼠的显像研究

目的探讨^99Tc^m标记针对小鼠双微体扩增基因（MDM2）mRNA的ASON（MDM2反义探针）用于前列腺癌无创性基因显像的价值。方法以HYNIC为螯合物,对含MDM2mRNA某段序列的ASON、错义寡核苷酸（ASONM）进行^99Tc^m标记,检测标记率及放化纯。建立荷人前列腺癌LNCaP裸鼠肿瘤模型,分为3组（每组10只）,进行^99Tc^m-HYNIC—ASON和^99Tc^mHYNIC—ASONM、^99Tc^mO4^-（对照）肿瘤显像。测量肿瘤／对侧肢体（T／M）比值,采用单因素方差分析对测量数据进行统计学分析。结果ASON的^99Tc^m标记率为（65．15±2．05）％,ASONM的^99Tc^m标记率为（64．93±2．18）％。^99Tc^m-HYNIC—ASON和^99Tc^m-HYNIC—ASONM经纯化后,放化纯均达90％以上。不同探针注射后1、4和10h时,^99Tc^m-HYNIC—ASON组T／M比值分别为3．217±0．125、3．749±0．201和4．028~0．186;^99Tc^m HYNIC—ASONM组分别为1．579±0．128、1．715±1．140和1．683±0．139;对照组分别为2．146±0．132、1．847±0．124和1．528±0．152.^99Tc^m-HYNIC—ASON1、4、10hT／M比值与对照组和错义组差异均有统计学意义（F=213．37～235．41,t=3．527～4．738,均P〈0．01）,而^99Tc^m-HYNIC—ASONM组各T／M比值与对照组差异均无统计学意义（t=2．154、2．287和2．236,均P〉0．05）。结论^99Tc^m标记的MDM2反义探针可在荷人前列腺癌裸鼠模型的肿瘤组织中特异性聚集,可以在早期对前列腺癌进行无创性的基因诊断。     

BTEB2反义基因转染对血管平滑肌细胞迁移的影响

目的：研究BTEB2反义基因转染对血管平滑肌细胞（VSMC）增殖的影响。方法：将BTEB2 cDNA反向克隆至腺病毒载体,构建携带反义BTEB2基因的重组腺病毒Ad-ASBTEB2;用Ad-ASBTEB2转染VSMC,经免疫印迹法检测BTEB2蛋白质表达;通过改良Boyden趋化小室检测VSMC迁移数;用免疫细胞化学技术检测促VSMC迁移血小板源性生长因子B链（PDGF）的表达。结果：（1）Ad-ASBTEB2转染明显抑制VSMC的BTEB2蛋白表达;（2）Ad-ASBTEB2组VSMC迁移数较未转染组（P〈0．01）和Ad．LacZ组（P〈0．01）显著减少;（3）Ad-ASBTEB2组PDGF-BB表达较Ad．LacZ组和未转染组显著降低。结论：BTEB2反义基因转染显著抑制AngⅡ诱导的VSMC的迁移,这种抑制作用可能是通过减少促迁移因子的表达而实现的。     

外源性p27KIP1基因抑制SGC7901细胞的增殖

研究p27^KIP1基因对胃癌细胞的细胞周期及细胞增殖的影响。采用脂质体转染法将p27^KIP1全长cDNA转入胃癌细胞系SGC7901中，通过免疫屯迹分析以及RNA斑点杂交方法检测p27^KIP1基因在蛋白质和mRNA水平的表达，细胞活力实验及软琼脂集落形成实验显示转染p27^KIP1基因对细胞增殖的作用；流式细胞仪观察目的的基因对该细胞的细胞周期的影响。结果显示，转染p27^KIP1的SGC7901细胞在mRNA和蛋白质水平均有高水平p27^KIP1的表达；细胞活力检测显示在外加Zn离子48h后细胞生长被抑制42％；转染p27^KIP1的SGC7901细胞的集落形成率较对照组明显减少（P＜0．01）；p27^KIP1的过表达能够显著地增加G1期的细胞数，由33．68％增加到69．29％（P＜0．01）。研究表明，p27^KIP1基因可抑制SGC7901细胞由G1期向S期过渡，从而抑制细胞增殖。     

Anti-miR-155反义寡核苷酸对人肺鳞癌H157细胞增殖的影响

目的：观察anti-miR-155反义寡核苷酸（AMOs）对肺鳞癌H157细胞增殖的影响。方法：将H157细胞分为对照组和AMOs处理组，AMOs处理组采用AMOs抑制H157细胞内miR-155的活性，液闪计数仪测定[^3H]-TdR掺入量，MTT法测定细胞增殖抑制率，流式细胞仪测定细胞周期。结果：与对照组相比，AMOs显著减少H157细胞[^3H]-TdR掺入量（P〈0．01），随着浓度从10nmol／L逐渐增加至于100nmol／L，H157细胞[^3H]-TdR掺入量亦随之减少（P〈0．01）；AMOs显著抑制H157细胞的增殖（P〈0.01），使G0／G1细胞比例显著增加，G2／M期细胞比例显著减少（P〈0．01）。结论：AMOs通过抑制H157细胞内高水平表达miR-155的活性，显著抑制H157细胞的增殖。     

99Tcm标记MDM2反义寡核苷酸的实验研究

目的研究^99Tc^m标记小鼠双微体扩增基因（MDM2）mRNA的反义寡核苷酸（ASON）显像诊断乳腺癌的价值。方法以联肼尼克酰胺（HYNIC）为螯合物对ASON、错义寡核苷酸（ASONM）进行^99Tc^m标记，检测标记率、放化纯及其与互补正义链（SON）的结合能力。阳离子脂质体（1ipofectamine 2000）包裹反义探针及错义探针转染人乳腺癌细胞（MCF-7），通过RT-PCR和West-em．blotting法观察乳腺癌细胞MDM2mRNA和蛋白表达。建立荷人乳腺癌MCF-7裸鼠肿瘤模型，分别进行体内分布和肿瘤显像研究。结果ASON的标记率为（57．24-2．98）％（n=5），ASONM的标记率为（56．3±3．01）％（n=5），经纯化后放化纯可达95％以上，且仍保持与互补链的结合能力。不同浓度反义探针作用于乳腺癌细胞24h后，各浓度组MDM2mRNA和蛋白的表达量差异均有统计学意义（P〈0．01），而错义探针对MDM2mRNA和蛋白的表达没有明显影响。体内分布显示，反义及错义探针主要经肝、肾排泄，注射反义探针后，肿瘤／血液和肿瘤／骨骼肌放射性比值随时间的推移而增加。注射反义探针后1h肿瘤显影，肿瘤／对侧肢体放射性比值随时间推移而增加，各时间点错义探针在肿瘤内的聚集量均明显少于反义探针，差异有统计学意义（P〈0．01）。结论^99Tc^m标记的MDM2ASON可在荷人乳腺癌MCF-7裸鼠肿瘤模型的肿瘤组织中特异性聚集，为乳腺癌的特异性诊断提供了一种可能的新方法。     

hNIS基因的组织特异性表达介导肝癌细胞摄取99Tcm

目的探讨人钠／碘同向转运体（hNIS）基因在肝癌细胞中的组织特异性表达介导^99Tc^m摄取的可行性。方法构建鼠白蛋白基因启动子／增强子（mAlb）引导下hNIS和潮酶素共同表达的逆转录病毒载体，该重组逆转录病毒感染大鼠肝癌细胞MH3924A建立稳定表达细胞系，用^125I摄取实验证实hNIS基因的功能表达。建立肝癌移植瘤大鼠模型。在体内和体外水平评价重组肝癌细胞对^99Tc^m的摄取和流出。绘制时间-放射性曲线和体内外放射性分布图。结果重组质粒构建成功。体外培养条件下，hNIS基因稳定转染细胞系摄取^99Tc^m高出野生型肝癌细胞254倍。50μmol／L NaClO3和500μmol／L哇巴因（Ouabain）可分别使MHm AlbhNIS6细胞摄取^99Tc^m降低97．56％和88．20％（P均〈0．01）。而^99Tc^m流出迅速，有效半减期不足2min，应用^99Tc^m／γ相机系统获得了转染肿瘤的清晰图像及定量数据，注射^99Tc^m O4^-后30min，MHmAlbhNIS6细胞形成的移植瘤摄取^99Tc^m比对照组高4倍。结论证实hNIS基因在肝癌细胞中的组织特异性表达介导^99Tc^m摄取；利用^99Tc^m／γ相机系统可无创、简单、定量检测hNIS基因的表达。     

肌酸激酶B在前列腺细胞中的表达及临床意义

目的：探讨肌酸激酶B（脑型肌酸磷酸激酶,CKB）在前列腺良性及恶性细胞中的表达差异及临床意义。方法：采用实时定量PCR方法检测CKB在BPH1与LNCaP细胞中的表达差异,采用电泳仪法进行血标本CKB检验,最后采用半定量PCR方法研究CKB与雄激素的相关性。结果：CKB在LNCaP的表达量是BPH1细胞中的12．3倍,血检验发现,CKB在未经内分泌治疗前列腺癌组阳性率（5／10）显著高于前列腺增生组（0／10）,差异有统计学意义（P〈0．05）,内分泌治疗前列腺癌组CKB阳性率（4／37）与前列腺增生组阳性率（0／10）相比差异无统计学意义（P〉0．05）。CKB在比卡鲁胺（bicalutamide,Casodex）阻断组LNCaP细胞中的表达明显低于无比卡鲁胺阻断LNCaP细胞。结论：CKB在恶性细胞中高表达,对未经内分泌治疗前列腺癌患者有一定诊断价值,并且其表达受雄激素的调节,可能在前列腺癌的发生发展中起重要作用。     

转染B7-H3基因对前列腺癌细胞摄取^18F—FDG和^18F—FLT的影响

目的研究转染B7同系物3（B7-H3）基因对前列腺癌细胞摄取^18F—FDG和^18F-FLT的影响,并探讨抗B7-H3单克隆抗体（简称单抗）对前列腺癌细胞的作用。方法用细胞计数试剂盒（CCK）-8检测鼠源性前列腺癌RM1细胞和转染B7-H3基因RM1的同种细胞（RM1-B7-H3）培养后0．5、1、2、3、4和5d的吸光度（A）值,并用流式细胞仪测定2种细胞的生长周期。在不同糖浓度（0、5．5和11．0mmol／L）、不同细胞数（每孔5×10^4～5×10^6）、不同摄取时间（20～120min）的条件下,测定2种细胞的^18F—FDG摄取率;并在细胞数为1×10^6、反应时间为100min的条件下行^18F-FLT细胞摄取实验。最后测定给予抗B7-H3单抗4H7后RM1-B7-H3细胞的^18F—FDG细胞摄取率。数据比较行单因素方差分析和两样本t检验。结果RM1-B7-H3细胞培养1、2和3d时的A值分别为1．59±0．23、2．26±0．15和2．01±0．60,较RM1细胞（1．22±0．14、1．10±0．09和1．04±0．15）高（t=3．923、19．228和4．467,均P〈0．01）;其他时间点2组间差异无统计学意义（t=-0．094、0．858、2．000,均P〉0．05）。RM1-B7-H3细胞的G1、S、G2／M期比例分别为（32．96±2．56）％、（39．11±2．57）％和（27．94±0．21）％,S期比例较RM1细胞（32．76±1．90）％高（t=3．442,P〈0．05）。2种细胞^18F—FDG摄取率均随培养基糖浓度的增加而降低,随细胞数和摄取时间的增加而升高。在1．0×10^6细胞、摄取100min时,RM1-B7-H3和RM1细胞的^18F—FDG摄取率分别为（55．07±3．99）％和（44．16±3．60）％,^18F—FLT摄取率分别为（5．25±0．81）％和（3．33±0．64）％,差异均有统计学意义（t=4．977和4．567,均P〈0．01）。给予4H7单抗后RM1-B7。H3细胞的^18F—FDG细胞摄取率为（45．36±2．92）％,较未加单抗组^18F—FDG细胞摄取率低（F=10．001,P〈0．01）。结论转染B7-H3基因能增强前列腺癌细胞的代谢和增殖活性,并提高细胞对^18F—FDG和^18F-FLT的摄取;给予抗B7-H3单抗4H7后,RM1-B7-H3细胞的^18F—FDG细胞摄取率降低。     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.     

MR imaging of disorders of the brachial plexus

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.     

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.     

肾细胞癌的MRI研究进展

肾细胞癌是最常见的成人肾脏恶性肿瘤。近年来，多种功能MRI成像技术（如扩散加权成像、灌注加权成像等）、多参数MRI联合分析以及影像组学等新兴影像处理技术被证实在肾细胞癌的诊断中具有较大的价值。目前，研究热点多集中于良恶性肿瘤的鉴别、组织学亚型的区分、肿瘤分期、预测核分级及判断预后。就MRI新技术及图像处理技术在肾细胞癌中的研究进展予以综述。     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

Influence of in vivo copper on MR images of the liver in rats

To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Dynamic MRI of the gallbladder lesions: Differentiation of benign from malignant

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.