光谱法及分子模拟研究芹菜素与人血清白蛋白的相互作用

利用紫外光谱、荧光光谱、红外光谱、圆二色光谱及分子模型等技术,在生理pH条件下,研究了芹菜素与人血清白蛋白的相互作用,计算了结合常数和热力学参数。分子模型研究表明,芹菜素与人血清白蛋白在亚结构域ⅡA结合,二者间的主要作用为疏水作用和静电作用,这与荧光光谱所得结果基本一致。红外光谱、圆二色光谱及同步荧光光谱均显示芹菜素与人血清白蛋白结合后没有改变人血清白蛋白的二级结构。     

毛细管电泳-发光二极管诱导荧光检测法分析肝硬化及正常人血清蛋白质的差异

应用毛细管电泳技术建立了人血清蛋白质毛细管电泳分析方法,对比了正常人与肝硬化患者血清蛋白质含量的差异。使用异硫氰酸荧光素(FITC)进行荧光标记,并考察光源与滤光片的波长、缓冲液的浓度、pH值、分离电压对分离效果的影响。建立了毛细管电泳-发光二极管诱导荧光法检测肝硬化患者血清及正常人血清蛋白质的方法;通过分离检测,获得了两者的蛋白质电泳谱图。经分析,在肝硬化患者的血清蛋白质中比在正常人的血清蛋白质中多检测到2个蛋白质峰,可能是和肝硬化发生相关的特异蛋白质;肝硬化患者与正常人的血清蛋白质电泳谱图的差异有统计学意义。该方法能实现人血清蛋白质的分离,可为临床诊断肝硬化做参考。     

肿瘤乏氧靶向响应的罗丹明荧光探针及其成像介导手术治疗

基于罗丹明的良好荧光性能, 经化学偶联反应制备并表征了一个偶氮乏氧特异响应的“Off-On”型荧光成像探针(FY-4). 从分子层面证实了其荧光“Off-On”性能和响应机制; 在L02正常细胞及4T1, HeLa和A549肿瘤细胞层面考察了其对受试细胞株的毒性和不同乏氧时间的荧光成像性能; 再利用4T1肿瘤模型, 分别以肿瘤原位注射和尾静脉注射的方式考察了其荧光成像性能, 并探究了其荧光成像介导切除肿瘤性能, 最后还考察了FY-4的生物安全性. 结果表明, FY-4有高的肿瘤乏氧靶向特异“关-开”响应的荧光成像差异显影及荧光成像介导切除肿瘤的潜能, 结合其良好的光物理性能、 生物安全性和明晰的给药时间等特性, 有望为生物医学荧光成像介导肿瘤切除提供新的研究工具.     

重型颅脑损伤并发多器官功能衰竭的临床分析

为探讨多器官功能衰竭（MSOF）的临床特点及治疗措施，回顾分析了广州市第六人民医院和天津市环湖医院救治的30例MSOF的临床资料并加以分析。结果表明，伤后3d内出现MSOF者4例，3－7d出现者19例，7d以上出现者7例；共有78个脏器衰竭（脑衰竭除外），其中肺功能衰竭24例，肾功能衰竭15例，应激性溃疡胃出血18例，心功能衰竭19例，肝功能衰竭2例，死亡28例，死亡率93．3％。强调对高危人群的重点监护和处理是防治MSOF的关键，对重型脑损伤患者及高危人群予以重视，积极处理原发病变并重视消除MSOF的诱发因素，早期给予积极有效的预防措施，可以减轻MSOF的发生率和死亡率。     

凋亡细胞线粒体膜电位的流式细胞术分析

采用流式细胞术与特异荧光探针JC-1相结合，在单细胞水平对X射线和化疗药物处理后的食管癌EC6细胞线粒体膜电位的变化进行了分析，凋亡细胞的线粒体膜电位下降，红色荧光减弱，随着剂量的增加，凋亡细胞的比例增大。     

用荧光猝灭和荧光加强两种理论研究头孢类药物与白蛋白的作用

应用荧光加强和荧光猝灭两种理论公式，对七种头孢类抗菌药物与人血清和牛血清白蛋白的作用作进行了对比研究，对药物与白蛋白的结合特点和通常的表征量：解离常数、猝灭常数、猝灭效率、能量转移效率、给体-受体作用距离等，进行了深入地分析。     

荧光黄与蛋白质相互作用的研究

研究了在人体生理条件下,荧光黄与人血清白蛋白和人体γ球蛋白间的相互作用。求出了荧光黄与蛋白质的结合常数及结合位置,并根据热力学参数确定了它们之间的主要作用力类型。认为”相分配模型“是对荧光黄与蛋白质相互作用模式的最好描述。     

荧光法研究苯胺蓝与人血清白蛋白的相互作用

用荧光光谱、同步荧光光谱研究了苯胺蓝和人血清白蛋白的相互作用。研究表明,苯胺蓝对人血清白蛋白的荧光发射有明显的猝灭作用,根据不同温度下的猝灭数据,由Stern-Volmer方程推断苯胺蓝对人血清白蛋白的猝灭属于静态猝灭。计算得到了结合常数KA、结合位点数n,同时计算得到的热力学常数表明苯胺蓝和人血清白蛋白作用力类型为静电作用和疏水作用结合。同时用同步荧光光谱探讨了苯胺蓝对人血清白蛋白构象的影响。     

多柔比星稀土配合物与人血清白蛋白相互作用的研究

运用荧光光谱法研究了多柔比星稀土配合物(ADM-M)与人血清白蛋白(HSA)的相互作用.结果表明:多柔比星稀土配合物对HSA的荧光有较强的猝灭作用,其荧光猝灭为混合猝灭过程.求得多柔比星稀土配合物与HSA的结合常数、结合位点数.由热力学参数确定了多柔比星稀土配合物与HSA的作用力类型.同时用同步荧光光谱法考察了多柔比星...     

磁共振/光学双模态分子探针的研究现状与展望

基于磁共振与荧光成像的双模态成像技术不仅克服了传统单一分子影像技术在灵敏度、特异度、分辨率等方面的固有缺陷，更是拓宽了分子影像技术在诊断及治疗监控等领域的研究范围及应用前景。本文将对磁共振/荧光双模态分子探针的应用情况和研究进展等进行综述。     

胆囊结石患者手术前后血清SOD、LPO的变化

为研究胆囊结石患者血清中超氧化物岐化酶活性水平,过氧化脂质含量及其变化簧 嘌呤氧化酶法和硫代巴比妥酸法测定了４８例胆囊结石患者手术前后血清中ＳＯＤ活性和ＬＰＯ含量。     

乙型肝炎患者血清中SOD与LPO含量分析

为了研究乙型肝炎患者血清中超氧化物歧化酶（SOD）活性水平、过氧化脂质（LPO）含量及其变化规律,应用黄嘌吟氧化酶法和硫代巴比妥酸法测定了53例乙肝患者血清中SOD与LPO含量,其中急性乙型肝炎（急肝）35例,慢性活动性乙型肝炎（慢活肝）18例。结果表明,乙型肝炎患者（包括急肝、慢活肝）血清中SOD的含量高于正常对照组（P＜0．05）,而LPO的含量也高于对照组（P＜0．01）,具有显著性差异,提示乙型肝炎患者体内存在着自由基紊乱。     

以氨基酸为配体的血液灌流用内毒素吸附剂的制备及性能研究

以琼脂凝胶为载体,氨基酸为配体,合成了内毒素吸附剂,并对其吸附效果进行了比较.对吸附剂的各种性质进行了表征,选取琼脂-赖氨酸吸附剂对内毒素血症的兔子进行血液灌流,可将血浆中的内毒素降至接近正常值,最高清除率达73.6%,且吸附剂具有良好的血液相容性.     

视网膜脱离后PVR的形成与氧自由基和锌、铜关系的研究

为探讨氧自由基和锌、铜在视网膜脱离后增殖性玻璃体视网膜病变 (PVR)中的作用 ,收集了 48例视网膜脱离患者视网膜下液 (SRF) ,利用紫外分光光度计测定了SRF中LPO的含量和SOD的活性 ,用原子吸收光谱法测定了Zn、Cu的含量。结果表明 ,随着PVR程度及玻璃体浑浊的加重、病程的延长 ,LPO含量增加 ,SOD活性明显下降 ,P <0 0 5 ,差异有统计学意义。提示SRF中LPO、Zn、Cu含量及SOD活性的改变与视网膜脱离后PVR的发生、发展有密切关系。     

茉莉酸甲酯和超氧化物歧化酶相互作用的光谱法研究

通过荧光光谱法和紫外吸收光谱法研究了超氧化物歧化酶和茉莉酸甲酯之间的相互作用。经过荧光光谱法的研究表明,超氧化物歧化酶和茉莉酸甲酯的相互作用是一个静态猝灭的过程,它们之间是以氢键和范德华力结合的,同时得到超氧化物歧化酶和茉莉酸甲酯的结合位点数n,表观结合常数K和热力学参数ΔH,ΔG,ΔS。而根据非放射性能量转移的F rster理论和同步荧光光谱证明茉莉酸甲酯和超氧化物歧化酶的相互作用位点同时接近超氧化物歧化酶色氨酸(Trp)和酪氨酸(Tyr)残基。     

Role of pyruvate and ascorbate production in regulation of antioxidant enzymes and membrane LPO levels in Fusarium Acuminatum

The role of pyruvate and ascorbate in the regulation of superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase enzymes; and, therefore, membrane lipid peroxidation (LPO) levels in Fusarium acuminatum was investigated in media containing either glycerin or glucose as a carbon source, depending on the incubation period, in the range of 5–25 g/L. Increasing SOD activity between d 9 and 16 of the incubation period showed a positive correlation with a significant increase in pyruvate production up to 15 g/L of glycerin and glucose. In addition, maximum ascorbate production was observed at 15 g/L of glycerin as 82.5 ± 2.1 and 20 g/L of glucose as 54±1.51, whereas CAT activity decreased with an increased concentration of both carbon sources. When compared with the LPO levels determined in media supplemented with glycerin and glucose, the minimum LPO level was 1.88±0.028 nmol of malondialdehyde/g wet wt at 15 g/L of glycerin on d 16, at which it was also observed to have a maximum pyruvate and ascorbate production and SOD, CAT, and GSH-Px activities of 75±1.42 μg/mL, 82.5±2.1 μg/mL, 32.5±0.634 μg/mL, 86.8±2.58 IU/mg, and 1.867 IU/mg, respectively. These results indicate that the biosynthesis of pyruvate and ascorbate may be involved in the regulation of antioxidant enzymes, depending on the glycerin and glucose concentrations, and also this defense network was effective in preventing membrane damage from oxidative stress.     

亲和吸附剂对细菌内毒素吸附性能的研究

制备了以球形纤维素为载体、8种氨基酸和1种聚赖氨酸为配基的吸附剂,对质量浓度为100.0pg/mL的内毒素水溶液进行了吸附研究,绘制了吸附等温线,并初步探讨了吸附机理.结果表明,精氨酸和赖氨酸配基具有良好的吸附能力,在1.5mL100.0pg/mL内毒素溶液中吸附量分别达到182.0和160.0pg/mL;吸附等温线显示,以赖氨酸为配基的吸附剂其吸附量随溶液内毒素浓度增加而线性增加,符合Langmuir吸附方程,吸附能力强,具有一定的临床应用前景.     

Study on the interaction of copper-zinc superoxide dismutase with aluminum ions by electrochemical and fluorescent method

The interaction of superoxide dismutase (SOD) with aluminum (Al) ions was investigated by cyclic voltammetry, fluorescence spectroscopy and synchronous fluorescence spectroscopy. The electrochemical activity of the SOD enzyme electrode was inhibited irreversibly by the addition of Al. Meanwhile, the static fluorescence quenching mechanism further revealed the existing of molecular complex of SOD with Al(3+). The association constant was obtained from Lineweaver-Burk plot. The experimental results of voltammetry and fluorescence spectroscopy indicated that the conformation of SOD molecule was altered by the formation of Al-SOD complex. It may influence the activity of SOD enzyme since the optimum action of SOD depends upon a particular configuration of electrostatic charges in the enzyme molecule.     

Oxidative stress is associated with the number of components of metabolic syndrome: LIPGENE study

Previous evidence supports the important role that oxidative stress (OxS) plays in metabolic syndrome (MetS)-related manifestations. We determined the relationship between the number of MetS components and the degree of OxS in MetS patients. In this comparative cross-sectional study from the LIPGENE cohort, a total of 91 MetS patients (43 men and 48 women; aged between 45 and 68 years) were divided into four groups based on the number of MetS components: subjects with 2, 3, 4 and 5 MetS components (n=20, 31, 28 and 12, respectively). We measured ischemic reactive hyperemia (IRH), plasma levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), total nitrite, lipid peroxidation products (LPO), hydrogen peroxide (H₂O₂), superoxide dismutase (SOD) and glutathione peroxidase (GPx) plasma activities. sVCAM-1, H₂O₂ and LPO levels were lower in subjects with 2 or 3 MetS components than subjects with 4 or 5 MetS components. IRH and total nitrite levels were higher in subjects with 2 or 3 MetS components than subjects with 4 or 5 MetS components. SOD and GPx activities were lower in subjects with 2 MetS components than subjects with 4 or 5 MetS components. Waist circumference, weight, age, homeostatic model assessment-β, triglycerides (TGs), high-density lipoprotein and sVCAM-1 levels were significantly correlated with SOD activity. MetS subjects with more MetS components may have a higher OxS level. Furthermore, association between SOD activity and MetS components may indicate that this variable could be the most relevant OxS biomarker in patients suffering from MetS and could be used as a predictive tool to determine the degree of the underlying OxS in MetS.     

Chemical Modification of Tryptophan Residues in Superoxide Dismutase from Camellia Pollen and Its Fluorescence Spectrum

The amino acid composition of the superoxide dismutase（SOD） from camellia pollen was measured and the tryptophan（Trp） residues were modified by using N-bromosuccinimide（NBS）. The results show that there are 21 Trp residues in an SOD molecule and seven of which are located on the surface of the enzyme. By researching the fluorescence spectra of the native SOD and the modified SOD, we have found that the emission wavelength of Trp is at 335 nm and the fluorescence intensity will decrease when the enzyme is modified. The results also show that potassium iodide（KI） can significantly quench the fluorescence of the native SOD, but it has a less pronounced effect on the modified enzyme. Glycerin as a surface activation reagent can stabilize the fluorescence of the modified enzyme.