静电吸附法制备抗αvβ3靶向脂质微泡及体外寻靶实验

 目的 探讨静电吸附方法制备携带抗αvβ3单克隆抗体的靶向微泡的可能性,并初步评价该靶向微泡在体外的寻靶能力.方法 将适量的负电荷脂质微泡造影剂与抗αvβ3单克隆抗体混合,利用静电吸附方法,制备亲黑色素瘤的靶向超声造影剂,并通过观察与黑色素瘤细胞的结合情况,验证该靶向微泡的靶向性.结果 静电吸附方法能够使抗体与微泡结合.携带抗αvβ3单克隆抗体的靶向微泡粘附在黑色素瘤细胞表面的靶向微泡数目明显多于普通对照微泡.结论 静电吸附法能够制备脂质靶向超声微泡,体外亲肿瘤细胞的寻靶试验验证了携带抗αvβ3单克隆抗体的靶向超声微泡具有一定的寻靶能力.     

基于聚合物微泡的超声/荧光双模态造影剂的制备及成像研究

目的 基于模块化思想,通过将具有荧光成像特性的量子点复合到具有超声响应特性的高分子微泡中,制备超声/荧光双模态医学造影剂.方法 将500 mg聚乳酸、50 mg樟脑、0.5ml油酸修饰的硒化镉/硫化锌量子点(CdSe/ZnS,2.3 μmol/L)溶解分散于10 ml二氯甲烷形成有机相,用碳酸铵溶液构成内水相,用聚乙烯醇溶液构成外水相,采用双乳溶剂挥发法和冷冻干燥技术相结合的方法制备兼具超声/荧光双模态成像功能的荧光微泡.用扫描电子显微镜观察荧光微泡形貌,以荧光分光光度计对其发光性能进行表征.搭建体外超声/荧光成像装置,以推注生理盐水的声像图为对照,观察装置中硅胶管注入荧光微泡后的超声对比增强情况和荧光增强情况及两者同步成像效果.评价荧光微泡在体内超声/荧光双模式下对新西兰大白兔肾脏的成像效果.结果 荧光微泡呈规则的球形,具有中空结构,平均粒径为(1.62±1.47) μm,超过99％的微泡直径小于8μm,能够满足超声造影剂大小的基本要求;荧光微泡的荧光发射峰位于632 nm,并能维持量子点良好的发光特性.体外超声/荧光成像结果示:管腔充满生理盐水时,声像图呈完全无回声;推注荧光微泡后,有造影剂的部分回声增强;紫外灯照射下,有造影剂的液柱见明亮红色荧光.推注荧光微泡后,兔肾脏在声像图上清晰显影.结论 成功制备基于聚合物微泡的超声/荧光双模态造影剂,该造影剂具有良好的回声特性和荧光成像能力,可以弥补单一造影剂的缺陷与不足.     

靶向超声造影评价兔腹主动脉粥样硬化的实验研究

目的探讨超声造影剂的靶向制备技术;评价携CD54单抗的超声造影剂在动脉粥样硬化诊断中的靶向价值和意义.方法整合CD54单克隆抗体及白蛋白微泡制备靶向超声造影剂.新西兰大白兔20只,高脂饮食建立动脉粥样硬化模型并随机分两组,分别使用普通和靶向造影剂行腹主动脉超声造影.视频密度法评价两种造影剂对腹主动脉内膜和粥样硬化斑块的造影增强效应.结果两组造影后血管内膜和粥样硬化斑块的视频峰值与造影前视频基础值相比均有显著增加(P<0.01).第1、2组实验对象分别使用普通和靶向造影剂造影后,两组对应的血管内膜和粥样硬化斑块的峰值视频密度之间的差异有统计学意义(P<0.01).结论携CD54单抗造影剂对粥样硬化血管内膜及斑块有靶向显影价值,可提高超声诊断敏感性.     

超声纳米微泡在基因治疗中的应用进展

作为对比增强超声的造影剂,已经被广泛应用至今。近年来,微泡不仅仅用于超声造影,还逐渐和治疗结合在一起,尤其是在药物及基因递送方面。但微泡的粒径较大,难以通过血管壁渗透到周围组织中,尤其是肿瘤组织。然而,粒径为纳米级的微泡,就有这种渗透的可能性。研究发现,纳米微泡的表面可以偶联许多特异性配体,例如单克隆抗体或者多肽。此外许多药物、基因等可以与纳米微泡结合,或者包裹在纳米微泡内部。本文以纳米微泡研究为背景,阐述微泡从对比增强的超声造影剂发展到一种基因递送媒介的演进历程及其发展前景。     

超声微泡造影剂的临床应用及研究进展

随着超声造影和微泡制备技术的不断发展,超声不仅作为一种临床诊断工具,而且更扩展了治疗领域.新型超声造影剂的临床应用是近年来超声医学研究的热点,具有广阔的应用前景.现就超声微泡造影剂的应用及研究进展综述如下.     

RGD靶向微泡造影剂的制备及其黏附效能

目的制备一种新型的RGD超声微泡造影剂,探讨其在体外与小鼠血管内皮细胞(b End.3)靶向黏附效果,为肿瘤血管新生超声分子成像奠定基础。材料与方法以"生物素-亲和素"体系制备出RGD靶向微泡造影剂,分为10μg/ml RGD肽封闭组和30μg/ml RGD肽封闭组,未携带RGD肽微泡造影剂作为空白对照。粒径分析仪、普通光镜下进行表征或检测。体外培养小鼠血管内皮细胞,采用多肽封闭静态黏附实验验证靶向性和黏附效率;应用平行板流动腔芯片,设置不同流体剪切力,观察RGD靶向微泡造影剂在血管内皮细胞表面的动态黏附效果。结果测得的RGD靶向微泡粒径为(4.09±0.07)μm。单个细胞表面黏附的微泡个数RGD肽封闭组与RGD-MBs组比较,10μg/ml RGD肽封闭组为(2.98±0.35)个(P<0.05),30μg/ml RGD肽封闭组为(1.78±0.23)个(P<0.001)。10μg/ml和30μg/ml RGD肽封闭实验表明,黏附在单个细胞表面的微泡数量分别降低54.64%和67.00%。在剪切应力1.5 dyne/cm2下,RGD靶向微泡在细胞表面黏附率随着剪切应力增大而增加(P<0.05)。当剪切应力为1.5 dyne/cm2时,RGD靶向微泡在细胞表面黏附率为(48.72±4.26)个,继续增大剪切应力,黏附率降低(P<0.05)。结论 RGD靶向微泡造影剂能特异性地黏附血管内皮细胞,有望作为超声分子探针检测评价整合素ανβ3在肿瘤血管新生中的表达,用于肿瘤的早期诊断及预后检测。     

基于多功能超声造影剂的肿瘤分子成像和可视化联合精准治疗的专家共识

纳米级超声造影剂是超声分子影像学发展的重要方向,也是肿瘤靶向性、可视化精准治疗及实现诊疗一体化的新方向。如何制备生物安全性、超声显影能力和靶向负载能力更高的超声造影剂等问题,亟待进一步规范。为此制定了多功能纳米超声造影剂用于肿瘤分子成像和诊疗一体化的专家共识,以新型多功能壳聚糖纳米泡携载阿霉素,体内外实验证实其具有较好的稳定性、生物安全性、靶向性及较强的肿瘤杀伤能力,为规范多功能纳米超声造影剂的制备、安全性评价及诊疗一体化应用等奠定基础。     

超声探针是超声分子成像技术的关键

超声分子成像是近年来提出的新一代医学超声成像方法,在肿瘤、心脑血管等疾病的早期检测和疗效评价方面有重大应用前景. 超声分子成像研究的重点和先决条件是超声分子探针的研制.所谓超声分子成像探针,一般为靶向超声微泡、造影剂或具有声信号源作用的微米或纳米颗粒.超声分子成像的核心是将目的分子的特异性抗体或配体连接到超声造影剂表面以构筑靶向超声造影剂,使超声造影剂结合到靶组织,在分子和细胞水平观察靶组织的解剖和功能,以反映靶组织在分子水平上的变化.     

脂质体纳泡超声造影剂的制备及体外超声显像效果观察

目的制备一种包裹C3F8的新型纳米级脂质体超声造影剂,考察其基本特性并评价充气后体外超声显影效果。方法采用乙醇注入法制备脂质体粒子,在显微镜及透射电镜下观察其形态,分布,并检测其粒径及Zeta电位。冷冻干燥制成冻干粉,充入C3F8,制得脂质体纳泡,在凝胶模型中检测增强超声效果。结果脂质体溶液呈乳白色悬液,在显微镜及透射电镜下,形态规则,分散均匀,平均粒径为(679.70±146.70)nm,Zeta电位(-0.05±11.10)m V;冻干粉重悬分散性好,无聚集;体外超声显示,脂质体溶液均不能增强超声基波及谐波模式图像;脂质体纳泡在低机械指数下,超声图像增强轻度增强,在较高机械指数下,基波及谐波模式图像均明显增强,且持续稳定显像。结论采用乙醇注入-冷冻干燥法成功制备出粒径小、可持续显像的新型脂质体纳泡超声造影剂,为超声造影剂小型化的制备及应用发展提供新的研究方向。     

靶向超声微泡对结肠癌新生血管分子成像的实验研究

目的 探讨以VEGFR2 (kinase insert domain receptor,KDR)为靶点的靶向超声微泡对裸鼠结肠癌新生血管的成像效果.方法 以生物素-亲和素桥接法将特异性结合VEGF主要受体KDR的小肽K237与脂质微泡耦联构建靶向微泡,用同样方法将对照肽与脂质微泡耦联,构建对照微泡.以KDR阴性表达的人结肠癌LS174T细胞株建立人结肠癌裸鼠移植瘤模型.12只荷瘤鼠经尾静脉随机先后注射靶向微泡、对照微泡,2种微泡注射间隔30 min.注射靶向微泡后5 min和注射对照微泡后5 min荷瘤鼠均行超声造影检查,观察各组微泡在肿瘤组织造影增强情况,测量肿瘤组织的声强度(Ⅵ).另取6只荷瘤鼠预先注射K237肽后再注射靶向微泡,观察微泡的成像效果.靶向微泡组、对照微泡组、小肽预先封闭组肿瘤组织的Ⅵ值比较采用单因素方差分析,组间多重比较采用最小显著性差异t检验.用免疫组织化学技术检测KDR在肿瘤组织表达及分布规律.结果 成功制备了靶向微泡.注射超声微泡后5 min超声检查显示靶向微泡组肿瘤组织超声造影明显增强,对照微泡组及小肽预先封闭组仅见轻度的超声造影增强.3组Ⅵ值差异有统计学意义(F=39.130,P＜0.01).靶向微泡组与对照微泡组Ⅵ值差异有统计学意义(30.18±9.56与8.28±4.74,t=6.91,P＜0.01);小肽预先封闭组Ⅵ值与靶向微泡组差异有统计学意义(9.23±3.44与30.18±9.56,t =4.91,P＜0.01).免疫组织化学结果显示,荷瘤鼠结肠癌新生血管内皮细胞KDR表达较正常组织血管内皮细胞KDR表达显著增加.结论 以KDR为靶点的靶向超声微泡可以与荷瘤鼠肿瘤新生血管内皮特异性黏附并有效评价肿瘤新生血管形成.     

Physiologic and pathologic calcifications and ossifications in the face and neck

The aim was to give a systematic presentation of physiologic and pathologic calcifications and ossifications in the face and neck with a special emphasis on clinical relevance. In a sometimes subacute setting one should recognize specific calcifications which often lead to important diagnoses such as fungal sinusitis or sclerosing labyrinthitis. In a more chronic situation intraocular calcifications in small children are pathognomonic for retinoblastoma. Juxtatumoral sclerosis of the laryngeal cartilage in laryngopharyngeal carcinoma is usually caused by tumor infiltration of the cartilage resulting in a higher tumor stage and, this way, has a major impact on the therapeutical strategy. Calcified lymph nodes are mainly unspecific but can be the result of tuberculosis or metastases of thyroid cancer. Cross-sectional imaging methods, most of all computed tomography, are ideally suited to reveal head and neck calcifications and ossifications, especially those which are clinically relevant.     

Head and neck infection and inflammation

This article discusses the imaging manifestations of infectious and inflammatory conditions of the head and neck. Special attention is paid to the sites, routes of spread, and complications of neck infections. Because the clinical signs and symptoms and the complications of these conditions are often determined by the precise anatomic site involved, anatomic considerations are stressed. Familiarity with the fascial layers, spaces of the neck, and the contents of each space is helpful for this discussion. The fascial layers of the neck are important barriers to infection, and once infection is established, the fascial layers play a part in directing its spread.     

幽门螺杆菌分泌与重组表达的VacA蛋白的分离纯化及其致细胞空泡效应与凋亡的对比研究

目的：分离纯化幽门螺杆菌分泌和重组表达的细胞空泡毒素抗原（ VacA）蛋白,并评价其致细胞空泡效应及致细胞凋亡效应。方法分别从幽门螺杆菌ATCC26695菌株培养上清和重组表达VacA蛋白的pQE30-VacA-E．coliM15基因工程菌中分离纯化VacA蛋白,经酸化后,以不同终浓度（5,10 ng／ml）分别与人胃腺癌AGS细胞共孵24 h,观察致空泡效应,并通过流式细胞术检测细胞凋亡。结果成功分离纯化出幽门螺杆菌分泌和重组表达的VacA蛋白;幽门螺杆菌分泌的VacA蛋白能显著引起AGS细胞的空泡样改变及凋亡（P＜0．01）,而重组表达的VacA蛋白致细胞空泡样改变及凋亡不显著（ P＞0．05）。结论幽门螺杆菌分泌的VacA蛋白有良好的空泡毒性及致凋亡效应,而重组表达的VacA蛋白无致空泡及凋亡效应,幽门螺杆菌分泌的VacA蛋白可用于VacA作用机制的研究。     

化学和生物学融合对国际武器公约履约的影响

化学武器公约（ CWC）和生物武器公约（ BWC）是为禁止生产、发展、储存和使用化学武器和生物武器而制定的国际公约。近年来,科学技术快速发展,知识交叉渗透,学科之间出现整合和融合,促进了科技进步和经济发展。其中化学和生物学融合在有力促进制药、健康卫生、绿色化学和环境保护等产业进步的同时,也对化学和生物武器公约的履约产生了重要的影响。该文综述了与化学武器和生物武器公约相关的化学和生物学融合进展,并分析其对公约履约的影响。     

Oxygen uptake and ventilation during rowing and running in females and males

This study evaluated if the ventilatory response to exercise is impaired by the cramp position of rowing. Maximal oxygen uptake (VO2max), maximal expiratory volume (VEmax), and maximal heart rate (HRmax) during rowing and running were compared in 55 males (age, mean +/- SD, 21 +/- 3 years; height 176 +/- 5 cm; body mass 72 +/- 6 kg) and 18 females (age 20 +/- 2 years; height 164 +/- 5 cm; body mass 61 +/- 4 kg). VEmax was larger during rowing than during running (males, 157 +/- 16 vs. 147 +/- 13 L min(-1); 114 +/- 9 vs. 105 +/- 11 L min(-1), P<0.01). Also VO2max was larger during rowing than during running (males, 4.5 +/- 0.5 vs. 4.3 +/- 0.4 L min(-1); females, 3.3 +/- 0.4 vs. 3.2 +/- 0.4 L min(-1), P<0.01). However, HRmax was lower during rowing than during running (males, 194 +/- 8 vs. 198 +/- 11 beats min(-1); females, 192 +/- 6 vs. 196 +/- 8 beats min(-1), P<0.05). VEmax was correlated to body mass and fat-free mass, as was VO2max. Thus, the oxygen pulse (VO2max/HRmax) was larger during rowing than during running, while the ventilatory equivalent for oxygen (VEmax/VO2max) was similar. We showed that bending the body during rowing does not seem to impair ventilation either in males or in females. The results indicate that VEmax and VO2max relate to body size and fat-free mass for both females and males. The findings indicate that the involvement of more muscles, the entrainment, and the body position during rowing facilitates ventilation and venous return and lowers maximal heart rate.     

Coracoclavicular and coracoacromial ligament calcification and ossification

Thirty-six patients with calcification or ossification at or around the coracoclavicular and coracoacromial regions were analyzed with regard to type, location, and configuration of the deposits and related clinical history. Calcification or ossification in the coracoclavicular region resulted largely from trauma (36%) or renal failure (28%). Trauma patients may develop punctate calcification or ossification but do not develop the tumoral type of calcification. About 5% of the renal failure patients had coracoclavicular ligament calcifications, one-half of which were of the tumoral type. Renal failure patients may have punctate or tumoral calcifications but do not develop ossification.     

CLIP相关技术的研究进展

在真核生物基因表达的转录后调节中,RNA结合蛋白（ RBP）起着关键作用,很多RBP的异常与人类疾病的发生密切相关。自2000年的RNA免疫沉淀和芯片分析方法（ RNA immunoprecipitation with differential display or microarray analysis , RIP-ChIP）出现以来,人们开始就RBP与RNA相互作用进行了系统而广泛的研究。经过改良和发展,基于体内实时紫外交联免疫沉淀法（ ultraviolet crosslinking and immunoprecipitation , CLIP ）、交联免疫沉淀cDNA文库高通量测序法（ high-throughput sequencing of CLIP cDNA library , HITS-CLIP）、光催化核糖核苷增强交联和免疫沉淀法（ photoactivatable-ribonucleoside-enhanced crosslinking and immunprecipitation , PAR-CLIP）以及提高个别核苷酸分辨率交联和免疫共沉淀法（ individual nucleotide resolution CLIP , iCLIP）等RIP-ChIP衍生方法相继产生,使用这些方法,可以解析RBP的RNA识别特异性,而且通过与高通量测序技术结合,可以实现转录组尺度的RBP的靶序列的鉴定,分辨率也得到极大提高。该文就RNA与蛋白的相互作用的基本原理及其研究进展、相关技术存在的问题以及发展趋势进行简要综述。     

Cross-sectional and longitudinal comparisons of self-reported and device-assessed physical activity and sedentary behaviour

ObjectivesTo examine the longitudinal associations and differences between self-reported and device-assessed physical activity (PA) and sedentary behaviour (SB), using a multifaceted statistical approach.DesignLongitudinal measurement burst.MethodsIn total, 52 university students (78% female) aged 18–38 years (mean = 21.94 ± 4.57 years) participated. The study consisted of three blocks of six days of measurement, during which participants wore an accelerometer on their wrist for the entire block, and self-reported their PA over the 6 days at the end of each block.ResultsMeaningful latent differences between methods were observed for moderate PA and SB across all three assessment periods, such that participants underreported the time spent in each activity. Bland–Altman plots revealed a positive mean difference for vigorous PA, with over-reporting increasing as mean levels increased. Negative mean differences were observed for all other intensities. Underreporting of moderate PA increased as the mean level increased, whereas for light PA and SB, underreporting decreased at high levels. Repeated measures correlations revealed a meaningful association for vigorous PA only, suggesting that as self-reported minutes increase so too do device-measured minutes.ConclusionsWe found evidence of cross-sectional and longitudinal differences and weak associations between self-reported and device-assessed PA and SB. Future work is needed to enhance the quality of self-reported methods to assess PA and SB (e.g., face and content validity), and consider improvements to the processing of device-based data.     

Old and dangerous: Prison and dementia

Older prisoners are the fastest growing group of prisoners in many countries. The purpose of this study is to explore the phenomenon of detention of persons suffering from dementia. Medline searches were conducted for relevant articles, chapters and books published until August 2016. Search terms included dementia, elderly, prison and criminal. Publications found through this indexed search were reviewed for further relevant references. As results, there is a lack of data about elderly with dementia in prisons. Given the rise in the average age, it is reasonable to hypothesize that the number of older prisoners is growing. Moreover, some elderly are imprisoned with a concomitant cognitive impairment or psychiatric disorder while others will develop such diseases once incarcerated. At the present time, legal and social systems seem unprepared to handle the phenomenon of dementia in prison. As proposal, health assessments for older first time offenders should become a practice inside the correctional facilities and include an evaluation for specific health issues, such as psychiatric comorbidity and cognitive impairment.