叶酸靶向超声造影剂的制备及体外寻靶实验研究

目的 制备偶联叶酸的靶向超声微泡造影剂,鉴定其基本性质,并探讨体外寻靶能力.方法 将DSPE-PEG(2000)Folate溶入微泡成膜材料中,制备叶酸靶向超声微泡造影剂.用DFY型超声图像定量分析诊断仪检测微泡粒径和浓度.通过光镜和激光共聚焦显微仪观察该靶向造影剂对SKOV3细胞的体外寻靶情况,以普通超声微泡作对照.结果 靶向超声微泡的大小、粒径及分布与普通超声微泡相似.体外寻靶试验显示,该靶向微泡可以较多并牢固地聚集到SKOV3细胞表面,而普通微泡对照组未见特异性结合.结论 成功制备出偶联叶酸的靶向超声微泡造影剂.该造影剂在体外对高表达叶酸受体的SKOV3细胞具有较强的特异性亲合力,有望成为靶向显像卵巢癌的理想造影剂.     

纳米级分子靶向超声造影剂的制备及其体外肿瘤靶向性实验研究

目的制备针对肿瘤HER2分子的纯纳米粒径分子靶向超声造影剂,观测其理化特性,并在体外肿瘤细胞中验证其特异靶向性。方法利用改良的薄膜水化法直接制备纯纳米粒径微泡,鉴定其基本理化特性、形态学表现及体外超声造影成像效果;利用"亲和素-生物素法"构建"纳米微泡-Affibody",体外多种肿瘤细胞验证其特异靶向性,同时观察其稳定性。结果直接制备出了纯纳米级微泡,粒径为(498.7±55.0)nm,各项理化特性及超声成像效果良好;新构建的"纳米微泡-Affibody"在体外对多种HER2(+)肿瘤细胞具有特异靶向性。结论 "纳米微泡-Affibody"体外特异靶向性强,稳定性好,为进一步进行体内肿瘤分子靶向超声造影及抗肿瘤分子靶向治疗奠定了基础。     

聚糖纳米微泡超声造影剂的制备及其超声显影效果

目的 制备聚糖纳米微泡超声造影剂,观察其基本特征及动物超声显影效果.方法 高速剪切法制备纳米微泡超声造影剂,光学显微镜和透射电镜观察纳米微泡大小、形态,马尔文粒度分析仪测粒径分布,细胞计数板计数纳米微泡,Zeta电位仪测表面电位,对比超声观察大鼠肾、心脏超声显影效果并测量声强度.结果 纳米微泡呈空心球形结构,分散均匀,形态规则,平均粒径(617±12)nm,浓度(7.2±0.6)×109/ml,Zeta电位(52.9±1.3)mV.24 h、45 d和90d三个时间点浓度、平均粒径和表面电位无明显差异(P＞0.05).用其可使小鼠肾、心脏超声显影明显增强,最大视频强度分别达(15.6±1.1)GU、(27.3±2.5)GU,可视增强持续时间(10±2)min.结论 聚糖纳米微泡稳定性和显像效果良好,有可能成为可穿过血管内皮间隙的新一代超声造影剂.     

叶酸介导靶向高分子造影剂的制备及体外识别研究

目的 合成叶酸介导靶向的聚乳酸共聚物,以其为靶向膜材制备靶向造影剂,表征造影剂性质.方法 以自制的叶酸-脯氨酸-乳酸共聚物(Fa-PLLA-Hpr)为膜材,应用双乳化-冷冻干燥法制备叶酸介导靶向高分子造影剂(MB-Fa-PLLA).采用激光粒径测量仪检测微泡的粒径,通过光镜观察该靶向造影剂(靶向造影剂实验组)对人卵巢癌SKOV3细胞的体外寻靶情况,并与游离叶酸干预组及空白对照组(普通微泡)比较.结果 FT-IR表征了靶向膜材的结构.成功制备叶酸介导靶向聚乳酸共聚物MB-Fa-PLLA.MB-Fa-PLLA在光镜下大小分布均匀,形态圆整,65％的微粒直径分布为500～800 nm,呈单峰分布,其亲水性较普通高分子微泡更好.体外寻靶实验显示,MB-Fa-PLLA可以较多并牢固地聚集到SKOV3细胞表面,而普通微泡未见特异性结合.结论 MB-Fa-PLLA亲水性好,对高表达叶酸受体的SKOV3细胞具有较强特异性亲合力,其有望成为靶向显像叶酸高表达肿瘤的理想造影剂.     

靶向PD-L1微泡对宫颈癌移植瘤抑制作用及靶向显影的实验研究

目的探讨靶向PD-L1微泡对宫颈癌移植瘤的抑制作用及靶向显影性。方法 (1)制备携PD-L1抗体的靶向脂质微泡,检测其一般特性及靶向显影性。(2)建立小鼠U14宫颈癌皮下移植瘤模型,随机分为对照组、空微泡组、靶向微泡组。(3)根据分组给予不同处理,绘制各组肿瘤生长曲线,计算抑瘤率,免疫组织化学法检测Bcl-2、Bax表达情况,RT-qPCR检测CD80、CD86表达情况。(4)分离小鼠脾淋巴细胞,与U14宫颈癌细胞共培养后,LDH法检测各组脾淋巴细胞体外杀伤效应。结果 (1)微泡镜下呈球形,平均粒径(1.09±0.21)μm,成功与PD-L1抗体结合。(2)体内外均具有靶向性。(3)与对照组相比,靶向微泡组小鼠肿瘤生长较缓慢,肿瘤体积质量明显较小(P0.05),Bax表达上调,Bcl-2表达下调(P0.05)。(4)靶向微泡组小鼠脾淋巴细胞在体外高效杀伤U14宫颈癌细胞,且CD80和CD86表达均上调(P0.01)。结论制备的靶向PD-L1微泡具有良好的体外靶向性及靶向显影性,可明显抑制小鼠U14宫颈癌移植瘤生长。     

以N-软酯酰基壳聚糖为壳膜的新型超声微泡造影剂的对比成像

目的 制备N-软酯酰基壳聚糖微泡(PCMB)类超声造影剂,评价其超声对比成像效果.方法 以N-软酯酰基壳聚糖为膜材料采用声振法制备PCMB造影剂,用光学显微镜、库尔特计数仪、Zeta电位仪检测其大小、形态、浓度和表面电位.经大鼠尾静脉团注0.1 ml该造影剂观察大鼠左心室、肝脏、肾脏超声造影效果,脱机分析峰值强度(PI)、达峰时间(TTP)、峰值减半时间(HPT)、廓清时间等参数,并与全氟显进行造影性能比较.结果 PCMB分布均匀,浓度为(2.88±0.45)×109/ml,直径为(1.31±0.07)μm(99.98%微泡直径小于8μm),表面电位为(55.03±3.08)mV;对大鼠左心室、肝脏、肾脏超声造影图像清晰,PI和TTP与全氟显相近(P>0.05),但HPT及廓清时间明显延长(P<0.001).结论 以廉价和生物相容性好的N-软酯酰基壳聚糖为壳膜材料制备新型超声造影剂具有良好的超声对比成像效果.     

载顺铂靶向纳米微泡对小细胞肺癌增殖抑制作用的实验研究

目的制备载顺铂抗前胃泌素释放肽(ProGRP)单抗靶向纳米微泡, 并研究其对小细胞肺癌(SCLC)增殖抑制效果及抗癌的分子机制。方法应用薄膜水化法制备载顺铂抗ProGRP单抗靶向纳米微泡, 研究其理化性质;建立10只SCLC裸鼠皮下移植瘤模型, 以空白纳米微泡作对照, 分析载顺铂靶向纳米微泡的超声分子靶向显影效果;另建24只SCLC荷瘤裸鼠模型, 随机分为4组:空白纳米微泡组、顺铂组、载顺铂纳米微泡组、载顺铂靶向纳米微泡组, 计算抑瘤率。采用CCK8法检测其对SCLC增殖的影响;运用RT-PCR和Western blotting分析4个处理组SCLC增殖相关基因P53、Rb、c-myc的mRNA和蛋白水平变化。结果成功制备载顺铂抗ProGRP单抗靶向纳米微泡, 粒径为(467.3±42.3)nm, 结构稳定;载顺铂靶向纳米微泡在SCLC裸鼠移植瘤体内具有良好的超声分子显影效果, 可明显抑制SCLC增殖;RT-PCR和Western blotting显示, 与对照组相比, 载顺铂靶向纳米微泡组的增殖相关基因P53、Rb的mRNA和蛋白水平显著上调, c-myc的mRNA和蛋白水平显著下调...     

靶向超声微泡MB_(ICAM-1)的制备及靶向实验研究

目的制备载抗ICAM-1(细胞间黏附分子-1)的靶向超声微泡MBICAM-1,鉴定制备微泡的基本性质,研究其在体内及体外的靶向能力。方法通过"生物素-亲和素"桥接法将抗ICAM-1结合到生物素化脂质微泡,制成MBICAM-1;检测制备微泡的浓度、粒径,观察微泡的形态;检测抗ICAM-1与微泡的结合率;ICAM-1质粒转染Hela细胞,观察转染后的Hela细胞与MBICAM-1结合,验证MBICAM-1体外靶向功能;制备家兔左侧跟腱炎症模型,用制备的微泡对家兔双侧跟腱行造影检查,验证MBICAM-1体内靶向能力。结果三种微泡平均粒径1.00~2.4μm,浓度2.4×108~10/ml;微泡的形态完整、规则,分布较匀;微泡和抗ICAM-1单抗的平均结合率为(86.5±5.3)%。MBICAM-1环绕在转染后的Hela细胞周围。MBICAM-1对家兔左侧跟腱造影呈高增强。结论采用"生物素-亲和素"桥接法可制备MBICAM-1;MBICAM-1在体外、体内均具有靶向功能。     

携GL-7靶向微泡造影剂对高脂饮食兔腹主动脉内膜的靶向作用

目的 探讨携GL-7靶向微泡造影剂对高脂饮食兔腹主动脉内膜体外特异性结合及体内增强显影效果.方法 14只新西兰兔用高脂饮食法建立腹主动脉内膜损伤模型,并随机分为两组,4周后分别使用对照微泡和靶向微泡造影剂进行腹主动脉超声造影,以视频密度法评价两种造影剂对动脉内膜的增强效果,荧光显微镜观察两种造影剂体内结合情况及与动脉内膜荧光染色的结合情况及荧光强度统计分析.结果 对照微泡、靶向微泡造影后血管内膜回声均较造影前增强,靶向微泡造影与对照微泡造影比较,血管内膜峰值视频密度差异有统计学意义(P<0.05).荧光显微镜观察,靶向微泡血管腔内呈现绿色荧光,而对照微泡血管腔内仅有微弱的绿色荧光.动脉血管冰冻切片结果显示,靶向微泡造影组动脉内膜有绿色荧光表达,而对照微泡造影组绿色荧光表达较弱,两组荧光强度差异有统计学意义(P<0.05).结论 GL-7靶向微泡造影剂与兔动脉血管内膜体内、体外特异性结合,可显著增强兔腹主动脉内膜靶向显影.     

细胞间黏附分子-1靶向微泡超声造影成像评价肾移植后急性排异反应

目的 探讨靶向超声分子成像评价肾移植后急性排异反应的可行性.方法 采用“亲和素-生物素”桥接法构建携抗细胞间黏附分子-1(ICAM-1)靶向微泡(MBI)和携同型抗体对照微泡(MB).10只SD大鼠行左侧肾异种移植术,术后72 h移植肾随机先后注入MBI和MB(间隔30 min),分别于注入3 min后行移植肾超声造影检查,并测量移植肾声强度(VI),最后进行肾组织病理及免疫组化检测.结果 移植肾在注入靶向超声微泡后可见肾区域明显灌注显影,延迟3 min显像MBI组在移植肾可见显著的超声显影增强.而MB组移植肾仅见轻度的超声显影增强,其显影强度较前者明显减弱.MBI组和MB组移植肾VI值分别为(27.0±7.4)U、(10.2±2.4)U,两者之间差异有统计学意义(F=64.744,P＜0.05).结论应用靶向ICAM-1超声微泡和超声造影结合能有效评价大鼠肾移植急性排异.     

Migraine and genetic and acquired vasculopathies

It is remarkable that migraine is a prominent part of the phenotype of several genetic vasculopathies, including cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL), retinal vasculopathy with cerebral leukodystrophy (RVCL) and hereditary infantile hemiparessis, retinal arteriolar tortuosity and leukoencephalopahty (HIHRATL). The mechanisms by which these genetic vasculopathies give rise to migraine are still unclear. Common genetic susceptibility, increased susceptibility to cortical spreading depression (CSD) and vascular endothelial dysfunction are among the possible explanations. The relation between migraine and acquired vasculopathies such as ischaemic stroke and coronary heart disease has long been established, further supporting a role of the (cerebral) blood vessels in migraine. This review focuses on genetic and acquired vasculopathies associated with migraine. We speculate how genetic and acquired vascular mechanisms might be involved in migraine.     

Fibrinogen and fibrin structure and functions

Fibrinogen molecules are comprised of two sets of disulfide-bridged Aalpha-, Bbeta-, and gamma-chains. Each molecule contains two outer D domains connected to a central E domain by a coiled-coil segment. Fibrin is formed after thrombin cleavage of fibrinopeptide A (FPA) from fibrinogen Aalpha-chains, thus initiating fibrin polymerization. Double-stranded fibrils form through end-to-middle domain (D:E) associations, and concomitant lateral fibril associations and branching create a clot network. Fibrin assembly facilitates intermolecular antiparallel C-terminal alignment of gamma-chain pairs, which are then covalently 'cross-linked' by factor XIII ('plasma protransglutaminase') or XIIIa to form 'gamma-dimers'. In addition to its primary role of providing scaffolding for the intravascular thrombus and also accounting for important clot viscoelastic properties, fibrin(ogen) participates in other biologic functions involving unique binding sites, some of which become exposed as a consequence of fibrin formation. This review provides details about fibrinogen and fibrin structure, and correlates this information with biological functions that include: (i) suppression of plasma factor XIII-mediated cross-linking activity in blood by binding the factor XIII A2B2 complex. (ii) Non-substrate thrombin binding to fibrin, termed antithrombin I (AT-I), which down-regulates thrombin generation in clotting blood. (iii) Tissue-type plasminogen activator (tPA)-stimulated plasminogen activation by fibrin that results from formation of a ternary tPA-plasminogen-fibrin complex. Binding of inhibitors such as alpha2-antiplasmin, plasminogen activator inhibitor-2, lipoprotein(a), or histidine-rich glycoprotein, impairs plasminogen activation. (iv) Enhanced interactions with the extracellular matrix by binding of fibronectin to fibrin(ogen). (v) Molecular and cellular interactions of fibrin beta15-42. This sequence binds to heparin and mediates platelet and endothelial cell spreading, fibroblast proliferation, and capillary tube formation. Interactions between beta15-42 and vascular endothelial (VE)-cadherin, an endothelial cell receptor, also promote capillary tube formation and angiogenesis. These activities are enhanced by binding of growth factors like fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF), and cytokines like interleukin (IL)-1. (vi) Fibrinogen binding to the platelet alpha(IIb)beta3 receptor, which is important for incorporating platelets into a developing thrombus. (vii) Leukocyte binding to fibrin(ogen) via integrin alpha(M)beta2 (Mac-1), which is a high affinity receptor on stimulated monocytes and neutrophils.     

Telemedicine and teleradiology technologies and applications

Summary. Telemedicine and teleradiology hold the key for improving future health care delivery. In this paper we first review current communication and computer technologies used in telemedicine and teleradiology. Five examples in teleradiology applications are given including hospital-integrated picture archiving and communication systems, tele-neuro-imaging, telemammography, university consortium teleradiology service, and teleradiology for second opinion. Parameters important to teleradiology applications like costs, image quality, system reliability, and turn around time are considered. Data security is discussed, including patient confidentiality and image authenticity-which will be a major issue in future teleradiology applications.     

创伤高血糖与感染和MODS早期诊断和干预

本文详细介绍了创伤后血糖应激适度理论,以及高血糖与感染和多器官功能不全综合征的关系;提出涉及胰岛B细胞功能不全的MODS实验诊断新方案和极化液个体化干预新措施,可早期发现创伤MODS、降低感染率及MODS发生率和病死率。     

腹膜后纤维化与肾积水发生关系的临床研究

目的：探讨腹膜后纤维化（RPF）导致肾积水的原因及诊治经验。方法：回顾分析2004年1月—2010年12月24例腹膜后纤维化致肾积水患者的诊治资料。结果：（1）RPF患者常见首发症状为腰背痛或腹痛（69.2%）;（2）红细胞沉降率（ESR）增快和血清IgG4升高最常见。超声检查仅提示上尿路积水。RPF的静脉肾盂造影（IVP）和CT尿路成像（CTU）表现具有特征性。IVP肾盂输尿管显影不良时,CTU能较清晰的显示上尿路影像。CT扫描发现腹膜后软组织肿块9例（37.5%）,优于超声检查;（3）输尿管松解和腹腔化手术治疗22例;行肾切除术1例;行输尿管置双J管术1例。最终确诊为继发性RPF8例,其中4例为术前诊断,3例为术中腹膜后软组织肿块冷冻活检证实,1例为术后病理证实;（4）特发性RPF手术后肾积水均获长期缓解,而继发性RPF的预后取决于原发疾病及其治疗方案。结论：影像学检查是诊断RPF的重要手段,CTU优于超声检查和IVP。输尿管松解和腹腔化手术可以使特发性RPF输尿管梗阻得到长期的缓解,术中对肿块进行冷冻活检有助于鉴别特发性和继发性RPF,及时调整治疗方案。     

探讨儿童慢性顽固性咳嗽与支原体感染的关系及临床治疗观察

目的探讨儿童慢性顽固性咳嗽与肺炎支原体（MP）感染的关系及临床疗效观察。方法采用回顾性研究方法对于现将2005年3月至2008年3月在我院的55例确诊慢性顽固性咳嗽患儿,主要表现为肺炎支原体感染为临床特点进行分析,并进一步临床治疗研究。结果①临床特点：在55例确诊慢性咳嗽的患儿中,以慢性顽固性咳嗽为主要症状。58％（32／55）的病例无肺部体征;②外周血：85％（47／55）的病例外周血变化不大,WBC（4—10）×10 9／L之间,嗜酸性粒细胞增多;③特别检查：47．27％（26／55）肺炎支原体IgM（MP—IgM）抗体阳性,83．64％（46／55）PeR技术检测肺炎支原体特异性DNA;④X光报告为多种形式。结论肺炎支原体（MP）感染是引起儿童慢性顽固性咳嗽的病因之一,对儿童慢性咳嗽,特别是顽固性咳嗽的诊治中应更加重视。     

Acetaminophen and acetylcysteine dose and duration: Past,present and future

Abstract

Acetylcysteine has been utilized successfully in the treatment of acetaminophen overdose since the 1970s. Although prospective trials as to efficacy and safety of acetylcysteine were conducted, there were no randomized controlled trials. This commentary addresses the reasons for this, and the background to choice of dose of acetylcysteine utilized in the oral and IV dosing regimens. Nomograms to predict possible hepatotoxicity based upon time of ingestion of acetaminophen were developed from a relatively arbitrary definition of toxicity as an aspartate aminotransferase/alanine aminotransferase (ALT/AST) greater than 1000 IU/L. While these have proved generally useful, patients still continue to develop hepatic damage after acetaminophen overdose, particularly if they present late after ingestion. The optimum management of these patients remains unclear, and one area of uncertainty is the dose and duration of acetylcysteine in various circumstances. This article discusses the issues that need to be elucidated to better target changes in acetylcysteine dose. The potential for measurements of other markers to improve treatment selection is the subject of further research.     

Physician and Nurse Practitioner Teamwork and Job Satisfaction: Gender and Profession

Designing interprofessional primary care teams composed of physicians and nurse practitioners (NPs) is a national priority. We assessed how profession and gender affect teamwork and job satisfaction among primary care physicians and NPs by using survey data from 186 physicians and 398 NPs practicing in New York State. Our regression models show profession (NP vs physician) moderates the associations of gender with teamwork and job satisfaction. Among NPs, men had higher job satisfaction than women. Among physicians, women had higher job satisfaction than men. Our results can benefit interprofessional primary care teams to optimize their professional and gender mix.