Molecular magnetic resonance probe targeting VEGF165: preparation and in vitro and in vivo evaluation

A new method for imaging the tumor human vascular endothelial growth factor 165 (VEGF 165) is presented. A magnetic resonance imaging (MRI) probe was prepared by crosslinking ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles to the aptamer for tumor vascular endothelial growth factor 165 (VEGF165‐aptamer). The molecular probe was evaluated for its in vitro and in vivo activities toward VEGF165. Enzyme‐linked immunosorbent assay showed that the VEGF165‐aptamer–USPIO nanoparticles conjugate specifically binds to VEGF165 in vitro. A cell proliferation test showed that VEGF165‐aptamer–USPIO seems to block the proliferation of human umbilical vein endothelial cells induced by free VEGF165, suggesting that VEGF165 is an effective target of this molecular probe. In xenograft mice carrying liver cancer that expresses VEGF165, T₂‐weighted imaging of the tumor displayed marked negative enhancement 3 h after the intravenous administration of VEGF165‐aptamer–USPIO. The enhancement disappeared 6 h after administration of the probe. These results suggest the targeted imaging effect of VEGF165‐aptamer–USPIO probe in vivo for VEGF165‐expressing tumors. This is the first report of a targeted MRI molecular probe based on USPIO and VEGF165‐aptamer. Copyright © 2014 John Wiley & Sons, Ltd.     

罗布麻叶HPLC指纹图谱构建及在种属鉴别中的应用

目的 建立罗布麻叶的HPLC指纹图谱,用以控制罗布麻叶的内在质量,并对罗布麻叶药材与其混淆品进行鉴别.方法 采用HPLC梯度洗脱的方法建立指纹图谱,"计算机辅助相似度评价系统"软件进行数据处理,据此对不同种属的药材进行比较.结果 建立的罗布麻HPLC指纹图谱方法的精密度、稳定性和重现性较好.罗布麻叶(红麻叶)HPLC指纹图谱共标定12个共有指纹峰,与白麻属样品图谱之间呈显著差异,可以依此鉴别.结论 HPLC指纹图谱可以用作罗布麻叶药材的质量控制.     

动态增强MRI定性诊断乳腺导管上皮非典型增生

目的 观察动态增强MRI（DCE-MRI）定性诊断乳腺导管上皮非典型增生（ADH）的价值。方法 回顾性分析经穿刺活检或局部切除组织活检诊断的64例乳腺单发ADH患者,以手术病理结果为金标准,比较恶性与良性病变患者临床资料及乳腺X线、DCE-MRI征象,分析DCE-MRI预测乳腺恶性ADH的效能。结果 64例乳腺单发ADH中,28例为恶性（恶性组）,36例非恶性（非恶性组）,组间活检方式、病灶最大径、MRI示乳腺实质背景强化（BPE）、乳腺X线表现差异均有统计学意义（P均<0.1）;将上述因素纳入Logistic多因素回归分析,结果显示仅BPE为乳腺恶性ADH的独立影响因素[OR=7.550,95%CI（1.575,36.197）,P=0.011]。DCE-MRI诊断BI-RADS 4A及以下者27例,其中3例为恶性;4A类以上（4B及4C）37例,25例为恶性,诊断敏感度89.29%（25/28）,特异度66.67%（24/36）,阳性预测值67.57%（25/37）,阴性预测值88.89%（24/27）。结论 DCE-MRI可用于定性诊断乳腺ADH;其所示中重度BPE为术后病理恶性的正相关因素。     

Relationship between ADAMTS4 and carotid atherosclerotic plaque vulnerability in humans

Background

Rupture of atherosclerotic plaques and the resulting thrombosis are vital causes of clinical ischemic events. Recent studies have shown that ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4) is a pathogenic factor of plaque vulnerability in mice. However, the relationship between ADAMTS4 and carotid atherosclerotic vulnerable plaques in humans remains unclear.

Antenatal Rh prophylaxis is unnecessary for “Asia type” DEL women

BackgroundGenerally Rh-negative patients need to be transfused with Rh-negative red blood cells. For pregnant women carrying Rh-positive fetus, the antenatal anti-D detection and Rh immunoglobulin prophylaxis are required worldwide. In East Asia, a RhD variant, termed “Asia type” DEL, was found in approximately 30% of apparent Rh-negative individuals. The antigenic and molecular properties of the DEL were previously defined. Few data discuss whether DEL could be immunized by D antigen clinically although DEL was reported arousing alloimmunization to true Rh-negative patients.Study design and methodsTo determine whether the DEL variant can be immunized to the D antigen, we retrospectively evaluated 104 Rh-negative pregnancies with allo-anti-D antibodies, and we also tracked 199 consecutive apparent Rh-negative pregnant women, with a history of gestations or parturitions but not subject to anti-D gamma-globulin prophylaxis, for evidence of allo-anti-D. The DEL variant was first excluded by ccee phenotypes and then identified through PCR analysis or sequencing.ResultsIn the retrospective study, we expected to find 30 DEL variants, yet none of the anti-D alloimmunized women were DEL-positive. And in the second group, none of 44 DEL-positive women versus 38 of 155 (24.5%) true Rh-negative women (those excluding DEL) formed allo-anti-D.ConclusionThe data indicate that the “Asia type” DEL variant does not appear at risk of alloimmunization to the D antigen. It strongly suggests that the antenatal Rh immune globulin prophylaxis is unnecessary for DEL women. Furthermore, it implicates that the “Asia type” DEL may be deemed Rh-positive safely for clinical transfusion therapy.     

Screening and confirmation of microRNA markers for distinguishing between menstrual and peripheral blood

The identification of menstrual blood (MB) and peripheral blood (PB) left at a crime scene is crucial for crime reconstruction, especially in sexual assaults. MicroRNAs (miRNAs), a class of non-protein coding molecules, have been demonstrated to be a viable tool for body fluid identification in forensic casework. Several groups have searched for miRNAs that are specific to different body fluids. Blood has been studied the most extensively. However, menstrual blood was only involved in five studies, and the results confirming the presence of specific miRNAs could not be reproduced in other studies. In this study, we attempted to screen new markers that can differentiate between menstrual blood and peripheral blood by using Exiqon’s miRCURY™ LNA Array. Five miRNAs were selected based on the microarray results, namely, miR-141-3p, miR-373-3p, miR-497-5p, miR-143-5p, and miR-136-5p, whose expression levels exhibited 27.95-, 17.96-, 16.74-, 10.14-, and 9.21-fold changes, respectively, compared to the level in peripheral blood. Two classic quantitative methods, TaqMan hydrolysis probes (TaqMan for short) and SYBR Green fluorochrome (SYBR Green for short), were applied in the confirmation step to study the impact of different quantitative methods on the results. Three miRNAs (miR-141-3p, miR-497-5p, and miR-143-5p) were confirmed by TaqMan and one (miR-141-3p) by SYBR Green. Furthermore, bioinformatic methods were applied to interpret the candidate miRNAs. Our results established a multi-step procedure for body fluid identification and showed that the choice of quantitative method is important when miRNAs are used to identify the origin of blood samples.     

Calcium sulfide (CaS), a donor of hydrogen sulfide (H2S): A new antihypertensive drug?

Hypertension is the leading cause of cardiovascular diseases, and an estimated 972 million people in the world are suffering from this problem. Indubitably, hypertension is an important worldwide public-health challenge. In recent years many efforts have been made to devise novel therapies involving new targets implicated in cardiovascular diseases. Hydrogen sulfide (H₂S) is a member of a growing family of “gasotransmitters”. It is clear that H₂S plays a pivotal role in the basal regulation of vessels tone. Also studies demonstrate that intravenous sodium hydrosulfide (NaHS), a donor of H₂S, dose-dependently decreases systolic blood pressure. However, because of its active chemical property, NaHS can be easily oxidized, even spontaneously ignited in the open air. Moreover, its solution is not stable. So the pharmacal use of NaHS is limited by its properties. Calcium sulfide (CaS), one of the effective components in a traditional herb, is another donor of H₂S. It has more stable chemical properties than NaHS. We hypotheses that CaS might be given by mouth as a new antihypertensive drug through certain dosage form designing. To test this hypothesis, we should establish animal models for studies including drug efficacy, drug safety, drug toxicology, drug metabolism and drug kinetics.     

液相色谱-串联质谱法同时测定人血浆中二甲双胍和格列吡嗪

建立了快速、灵敏的液相色谱-串联质谱法测定人血浆中的二甲双胍和格列吡嗪。血浆样品经0.3%甲酸-乙腈(v/v)沉淀蛋白后，以乙腈-水-甲酸(70∶30∶0.3，v/v/v)为流动相，流速为0.50 mL·min^-1。Zorbax Extend C₁₈柱分离，采用大气压化学电离源；以选择反应监测(SRM)方式进行正离子检测。用于定量分析的离子反应分别为m/z 130→m/z 60(二甲双胍)，m/z 446→m/z 321(格列吡嗪)和m/z 256→m/z 167(内标，苯海拉明)。测定血浆中二甲双胍的线性范围为2.00～2 000 ng·mL^-1， 定量下限为2.00 ng·mL^-1； 格列吡嗪的线性范围为1.00～1 000 ng·mL^-1， 定量下限为1.00 ng·mL^-1。该方法专属性好，灵敏度高，准确快捷，适用于二甲双胍和格列吡嗪的临床药代动力学研究。     

微型心尖轴流泵的结构及流体力学特性研究

目的：通过研制微型心尖轴流泵的样机并实测其流体力学特性，初步证实其可行性。方法：微型心尖轴流泵无前导叶，使泵体缩短并保留入口处的旋转血流分量。泵体外壁上的环形缝合裙将泵体分为前后两段。前段长度与心尖部室壁心肌的全层厚度相等。植入心脏时，泵体前段由心尖部插入，由于缝合裙限制，泵体前段不过度进入心室腔，仅以泵入口与心室腔相连通，在有效地引流心室的同时可避免心腔内植入过多的异物和液流死区。基于以上设想，研制的样机直径为20.6mm，泵管直径为13mm，长度为65mm，总体积约为30cm^3，总质量约为50g。在模拟循环台上进行流体力学特性测试，观察了血液动力学效果。结果：随着轴流泵转速的增加，模拟左心室的压力逐步下降，在输出压力为13.332kPa（100mmHg）条件下，轴流泵转速为12000r／min时流量可达5L／min，消耗功率接近10W。结论：样机测试表明微型心尖轴流泵结构设计可行，有望成为长期应用的植入式心脏辅助装置。