无机纳米晶体量子点光学成像应用进展

光学成像是分子成像技术的重要组成部分,主要包括荧光成像、生物发光成像及扩散光学成像。无机纳米晶体量子点（QDs）因具有独特光学性质（如激发光谱宽且连续、发射光谱窄且对称、荧光强度高、抗光漂白能力强等）而成为光学成像的热点研究领域。该文综述了QDs的光学性质、在光学成像中的体内外应用、局限性及目前存在的问题。     

不同粒径的石墨烯量子点在PC12细胞中的成像效应及细胞毒性

 目的 探究不同粒径的石墨烯量子点(graphene quantum dots,GQDs)在PC12细胞中的细胞成像效应及细胞毒性。方法 通过动态光散射法(DLS)对GQDs的水合粒径和zeta电位进行表征,采用CCK-8试剂盒检测GQDs对PC12细胞的毒理效应,使用激光共聚焦显微镜比较不同粒径的GQDs在PC12细胞中的荧光成像效应。结果 GQDs对PC12细胞的毒性效应是呈尺寸依赖性的,15 nm的GQDs比50 nm GQDs对PC12细胞的细胞毒性低,500 μg/ml的15 nm GQDs孵育48 h后,细胞活力仍保持在80%以上。对15 nm的GQDs更容易被PC12细胞摄取,80%以上的细胞能成功显影,表现优异的细胞成像效应。结论 GQDs细胞毒性低,细胞成像效果好,是一种适合神经系统成像的纳米材料。     

超声弹性成像、萤火虫成像及CDFI在乳腺癌诊断中的应用

目的 :探讨超声弹性成像、萤火虫成像技术及CDFI对乳腺癌的诊断价值。方法 :回顾性分析拟诊为乳腺癌并行乳腺肿块切除的180例(194个肿块)女性患者,术前均行二维灰阶超声、萤火虫成像、CDFI及超声弹性成像,以组织学病理结果为金标准,探讨上述方法对乳腺癌的诊断价值。结果:194个肿块中,良性19个,恶性175个。弹性成像与萤火虫成像、CDFI联合应用诊断乳腺癌的特异度为90.2%,与组织学病理检查结果高度相关。结论:超声弹性成像与萤火虫成像、CDFI联合应用对乳腺良恶性肿块具有较好的诊断价值。     

量子点成像技术在宫颈癌及卵巢癌诊断和治疗中的应用

宫颈癌及卵巢癌都是目前严重威胁女性健康的妇科恶性肿瘤,发病呈日益年轻化且发病率有逐年上升趋势。有数据统计,全世界每年约有宫颈癌新发病例50万,约有2313万妇女死于该病,其中80%的新发病例是发生在发展中国家,而我国每年宫颈癌新发病例约占全世界发病人数的1/3[1]。卵巢癌每年新发病例约为20万,占全部女性癌症的4%,死亡率为3%,在各种妇科恶性肿瘤引起的死亡率中占首位,     

石墨烯量子点的生物学应用

石墨烯量子点是石墨烯家族的衍生物,石墨烯量子点除了具有石墨烯的优良性能,还具有量子限制效应和边界效应所产生的一系列新的特性,因此吸引了各领域科学家的广泛关注。石墨烯量子点这类新颖材料的研究在这两三年内,无论是实验还是理论方面均取得了极大进展。石墨烯量子点生物相容性好,能够光致发光,具有光电特性,可用于生物成像和生物传感器。作者着重探索石墨烯多样的生物学应用,并从石墨烯量子点的发展、特性、制备方法、修饰、生物学应用、生物安全性等方面进行综述。     

二维超声、三维彩超与超声弹性成像诊断乳腺肿物性质的对比研究

目的探讨二维超声、三维彩超与超声弹性成像在诊断乳腺肿物性质的敏感性、特异性和准确率,以判断它们的临床应用价值。方法对120例（共178个肿物）患者分别进行对照,分析其敏感性、特异性及准确率。结果二维超声诊断乳腺恶性肿物的敏感性、特异性和准确率分别为76．8％（43／56）、86．9％（106／122）、83．7％（149／178）;三维彩超诊断乳腺恶性肿物的敏感性、特异性和准确率分别为89．3％（49／56）、92．6％（113／122）、91．0％（162／178）;超声弹性成像诊断乳腺恶性肿物的敏感性、特异性和准确率分别为94．6％（53／56）、95．1％（118／122）、96．7％（171／178）。超声弹性成像与二维超声及三维彩超对乳腺肿物性质的诊断结果进行比较,差异均具有统计学意义（P〈0．05）。结论在诊断乳腺肿物性质中,超声弹性成像具有重要临床应用价值,其敏感性、特异性及准确率均优于二维超声及三维彩超。     

常规超声结合弹性成像对乳腺癌的诊断价值

目的:探讨常规超声结合弹性成像(ultrasonic elastography,UE)对乳腺癌诊断的临床价值。方法:502例患者,共567个肿块纳入本研究,分为良性组及恶性组,对比2组患者间临床资料差异有无统计学意义。结果:常规超声联合UE诊断乳腺癌的敏感性为93.8%,特异性为88.1%,准确性为90.3%,敏感性和准确性均高于常规超声,差异有统计学意义(χ2=369.5,P<0.001),同时也高于单项UE(χ2=332.2,P<0.001)。结论:在规范评分指标的前提下常规超声联合UE对鉴别乳腺良恶性肿块具有较高的临床应用价值,可提高诊断乳腺癌的敏感性和准确性,对乳腺癌的早期诊断及术前分期具有重要参考价值。     

实时剪切波弹性成像鉴别乳腺肿瘤良恶性的初步探讨

目的 :探讨实时剪切波弹性成像技术(shear wave elastography,SWE)对乳腺肿块良恶性的鉴别诊断价值。方法 :选择我院行乳腺彩色多普勒超声和SWE检查检出乳腺肿块且经手术病理证实的女性患者54例,共72个乳腺肿块,对其SWE图像进行回顾性分析。应用ROC曲线确定SWE判断乳腺恶性肿瘤的最佳指标,获得其最佳诊断界值。结果:1乳腺良性肿瘤SWE典型表现:蓝色为主,颜色分布均匀;恶性肿瘤SWE典型表现:红色为主,颜色分布较杂乱。2与良性肿瘤相比,恶性肿瘤的平均弹性模量值(Emean)、标准差(SD)、与周边正常乳腺组织弹性模量的比值(Ratio)均明显增加,差异均有统计学意义(均P0.01)。3以病理结果为金标准,绘制SWE技术参数Emean、SD、Ratio的ROC曲线,其曲线下面积分别为0.933、0.891和0.753,表明Emean是诊断乳腺恶性肿瘤的最佳指标,截断值为46.41 k Pa。结论:SWE可定量测定乳腺肿块的弹性模量值,为乳腺肿块的良恶性鉴别诊断提供依据。     

实时组织弹性成像对乳腺肿瘤鉴别诊断的价值

目的探讨实时组织弹性成像对乳腺肿瘤鉴别诊断的临床应用价值。方法采用实时组织弹性成像进行良恶性鉴别和诊断,采用实时弹性成像评分法进行实时组织弹性成像对乳腺肿瘤鉴别诊断的效能分析。结果以实时组织弹性成像评分3分以下（包括3分）为良性病灶标准,实时组织弹性成像评分在4分以上（包括4分）为恶性病灶标准,进行实时组织弹性成像评分鉴别诊断乳腺病灶良恶性的效能分析发现,实时组织弹性成像评分对良恶性鉴别诊断的灵敏度、特异度、阳性预测值、阴性预测值分别为84．21％、95．83％、76．19％、97．46％。结论超声实时组织弹性成像技术具有无创、无痛重复性较好等各种优势,在乳腺方面的应用有较大的临床意义。     

声脉冲辐射力成像对乳腺良恶性结节的鉴别诊断价值

目的 :探讨声脉冲辐射力成像(acoustic radiation force impulse,ARFI)在诊断乳腺良恶性结节中的价值。方法:分析128例共145个经病理证实的乳腺结节的声脉冲辐射力成像特征。采用ROC曲线评价剪切波速度值对乳腺病灶良恶性的鉴别诊断价值,并确定临界值。结果:145个结节中,良性结节107个,恶性结节38个。乳腺病灶良性组与恶性组的剪切波速度(shearwave velocity,SWV)值分别为(2.89±1.13)m/s和(6.57±1.36)m/s,2组差异有统计学意义(P0.05)。以SWV值3.37 m/s为临界值诊断乳腺病灶的良恶性的敏感度、特异度、准确度分别为89.4%、89.7%、90.3%。结论:ARFI为乳腺结节的良恶性鉴别诊断提供了新的分析方法,具有重要的临床价值。     

Real time in vivo non-invasive optical imaging using near-infrared fluorescent quantum dots

RATIONALE AND OBJECTIVE: Deep-tissue optical imaging is of particular interest, as the equipment costs are lower than for competing technologies such as MRI. For this purpose, the development of novel contrast agents with near-infrared (NIR) fluorescence is especially important. We report on the use of NIR semiconductor nanocrystals in deep-tissue in vivo optical imaging. MATERIALS AND METHODS: Semiconductor nanocrystals of CdMnTe/Hg were grown in aqueous solution and then coated with bovine serum albumin (BSA). The nanocrystals were approximately 5 nm in diameter and have a broad fluorescence peak in the NIR (770 nm). Nanocrystals were injected either subcutaneously or intravenously into athymic NCR NU/NU and C3H/HENCR MTV mice and then excited with a spatially broad 633 nm source; the resulting fluorescence was captured with a sensitive CCD camera. RESULTS: We have demonstrated that the nanocrystals are a useful angiographic contrast agent for vessels surrounding and penetrating a murine squamous cell carcinoma in a C3H mouse. Preliminary assessment of the depth of penetration for excitation and emission was done by imaging a beating mouse heart, both through an intact thorax and after a thoracotomy. The temporal resolution associated with imaging the nanocrystals in circulation has been addressed, and the blood clearance for this contrast agent has also been measured. CONCLUSIONS: There was no significant photobleaching or degradation of the nanocrystals after an hour of continuous excitation. The stability of the nanocrystals together with the time resolution of the optical detection makes them particularly attractive candidates for pharmacokinetic imaging studies.     

基于荧光碳点的免疫荧光探针构建及其对大肠杆菌的特异性识别

目的：将碳点（ CDs）应用在免疫荧光探针成为取代传统荧光染料的新型标记物。方法通过微波加热方法制备高强荧光碳点,并通过EDC偶联法与大肠杆菌抗体结合形成复合免疫荧光探针,以大肠杆菌O157∶H7为检测模型进行特异性识别实验。结果碳点成功应用在免疫标记大肠杆菌O157∶H7,并可见多色荧光。结论免疫荧光探针成功地识别大肠杆菌O157∶H7,表明碳点可作为免疫荧光探针的荧光标记物,有望制成具有自主知识产权的新型低毒生物传感器。     

Gadolinium‐labeled quantum dots for molecular magnetic resonance imaging: R1 versus R2 mapping

Quantum dots labeled with paramagnetic gadolinium chelates can be applied as contrast agent for preclinical molecular MRI combined with fluorescence microscopy. Besides increasing the longitudinal relaxation rate, gadolinium‐labeled quantum dots may increase the transverse relaxation rate, which might be related to their magnetic properties. Furthermore, molecular MRI experiments are primarily conducted at high magnetic fields, where longitudinal relaxation rate becomes less effective, and the use of transverse relaxation rate as a source of contrast may become attractive. Consequently, the optimal method of contrast enhancement using gadolinium‐labeled quantum dots is a priori unknown. The objective of this study was to compare longitudinal relaxation rate– and transverse relaxation rate–based contrast enhancement, proton visibility, and changes thereof induced by gadolinium‐labeled quantum dots targeted to the angiogenic vasculature of murine tumors, using in vivo longitudinal and transverse relaxation rate mapping. At a field strength of 7 T, longitudinal relaxation rate–based measures were superior to transverse relaxation rate–based measures in detecting both the level and spatial extent of contrast agent–induced relaxation rate changes. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.     

In vivo fluorescence imaging of the reticuloendothelial system using quantum dots in combination with bioluminescent tumour monitoring

Purpose We characterised in vivo fluorescence imaging (FLI) of the reticuloendothelial system using quantum dots (QD) and investigated its use in combination with in vivo bioluminescence imaging (BLI). Materials and methods In vivo FLI was performed in five mice repeatedly after the intravenous administration of QD without conjugation to targeting ligands. Ex vivo FLI of the excised organs was performed 24 h after QD injection in three mice. Seven days after intravenous inoculation of luciferase-expressing model cells of a haematological malignancy, mice were injected with the QD or saline (n = 5 each), and combined BLI/FLI was performed repeatedly. Additional five mice inoculated with the tumour cells were examined by in vivo BLI/FLI, and the structures harbouring bioluminescent foci were determined by ex vivo BLI. The utility of combining FLI with bioluminescent tumour monitoring was evaluated. Results In vivo FLI after QD injection allowed long-term, repeated observation of the reticuloendothelial system in individual mice, although fluorescence intensity and image contrast gradually decreased over time. Ex vivo FLI verified selective accumulation in reticuloendothelial structures. The administration of QD did not affect whole-body bioluminescent signal intensities during longitudinal tumour monitoring. In vivo BLI/FLI, accompanied by fusion of both images, improved the accuracy and confidence level of the localisation of the bioluminescent foci. Conclusions In vivo FLI using QD provides an overview of the reticuloendothelial system in living mice. In combination with bioluminescent tumour monitoring, fluorescent reticuloendothelial imaging is expected to provide valuable information for lesion localisation.     

人肾尿酸转运蛋白1基因克隆、抗体制备及其在肾小管上皮细胞中的定位

目的 制备人尿酸转运蛋白1(hURAT1)多克隆抗体并利用该抗体检测hURAT1在肾组织中的表达及亚细胞定位。方法 用RT-PCR方法从人肾组织中扩增出hURAT1基因全长及其抗原表位区，分别构建绿色荧光蛋白hURAT1-pEGFP融合表达载体和GST融合表达载体pGEX-5X-1。诱导表达并纯化GST融合蛋白，利用改良的蛋白免疫法制备多克隆抗体；Western blot及免疫组化方法观察人肾组织的hUART1基因产物的表达。将hUPAT1-pEGFP重组质粒转染细胞，激光共聚焦显微镜动态观察hURAT1-pEGFP在肾小管上皮细胞LLC-PK1细胞膜的定位及表达。结果 成功获得高效特异的hURAT1抗体，利用该抗体证实hURAT1基因编码产物分布于人肾组织近端肾小管刷状缘，Western blot证实hURAIT1蛋白在肾组织中表达。激光共聚焦显微镜动态观察显示hURAT1-pEGFP定位于LLC-PK1细胞膜。结论 制备的hURAT1抗体及其全长基因可用于hURAT1基因的生理功能及病理研究，hUPAT1基因编码产物分布于人肾组织近端肾小管刷状缘。     

乳腺珠蛋白及其临床应用前景

乳腺珠蛋白（mammaglobin）是近年来发现的具有明确乳腺组织特异性的蛋白，与促进乳腺上皮生长有关。已发现，乳腺珠蛋白在乳腺癌诊断和治疗方面具有潜在价值。     

EGFP标记的VEGF165重组质粒的构建及其在骨髓间充质干细胞中的表达

目的构建pIRES2-EGFP-VEGF165真核表达质粒,并在大鼠骨髓间充质干细胞内表达。方法应用DNA重组方法构建pIRES2-EGFP-VEGF165,并将其转染到大鼠骨髓间充质干细胞内,采用ELISA和MTT法检测转染后细胞培养上清液中VHGF165的含量及生物活性。结果成功构建了pIRES2-EGFP-VHGF165,将其转染骨髓间充质干细胞后,VEGF蛋白表达水平明显增高．转染后的细胞培养上清具有促使内皮细胞增殖的生物活性。结论成功构建了真核表达质粒pIRES2-EGFP-VEGFl65．将其转染骨髓间充质干细胞后可高水平地表达具有生物学活性的VEGF蛋白。