重金属离子的免疫检测研究进展

农畜产品中残留的重金属离子已对人类安全构成严重威胁,急需快速、高效的重金属残留检测方法。重金属离子免疫检测是一种新型的检测方法,与传统检测方法相比,具有省时、省力、费用低廉、便于携带、易于操作等优点。除了化学螯合剂之外,植物螯合肽和金属硫蛋白也可用来制备重金属免疫原。重金属离子的免疫检测可分为多克隆抗体免疫检测和单克隆抗体免疫检测,前者包括荧光偏振免疫检测,后者包括间接竞争性ELISA、一步法竞争性免疫检测和KinExA免疫检测。作为一种辅助方法,胶体金快速免疫层析法可初步检测样品中的重金属离子浓度。     

金属离子对地衣芽孢杆菌合成多聚γ-谷氨酸的影响

多聚γ 谷氨酸 [γ Ｐｏｌｙ(ｇｌｕｔａｍｉｃａｃｉｄ) ,γ ＰＧＡ]是由某些杆菌 (Ｂａｃｉｌｌｕｓ)合成的一种细胞外水溶性高分子氨基酸聚合物 ,是由Ｌ 谷氨酸、Ｄ 谷氨酸两种构型的单体通过γ 酰胺键聚合形成的[1 ] 。γ ＰＧＡ具有极佳的成膜性、成纤维性 ,阻氧性、可塑性、粘结性、保湿性和可生物降解等许多独特的理化和生物学特性[2 ,3] 。因此 ,γ ＰＧＡ可以被广泛用于医药制造 ,食品加工 ,蔬菜、水果、海产品防冻、保鲜 ,化妆品工业 ,烟草、皮革制造工业和植物种子保护等许多领域 ,是一种有极大开发价值和前景的多功能新型生物制…     

Metal ions in biological systems. vol. XVIII. Circulation of metals in the environment : Edited by Helmut Sigel,Marcel Dekker,New York and Basle, 1984, 397 pp.

The solvent, pressure and temperature dependencies of the lowest energy metal to ligand charge transfer absorption bands were studied for a series of complexes of the type Mo(CO)₄(N$\text{N}$), where N$\text{N}$ = 2,2′-bipyridine, 1,10-phenanthroline and biacetylbis(phenylimine). Throughout the series of complexes the absorption bands shift to shorter wavelength in more polar solvents or on increasing the pressure in a particular solvent, but to longer wavelengths on increasing temperature. These main tendencies can be accounted for in terms of solvent polarity and its dependence on pressure and temperature.     

Chitosan Interactions with Metal Ions and Dyes: Dissolved-state vs. Solid-state Application

Summary Chitosan is an amino-polysaccharide with highly efficient properties for the binding of metal ions and anionic dyes. Uptake may occur through chelation on free amino functions (at near-neutral pH) or by electrostatic attraction on protonated amino groups (in acidic solutions). The polymer is soluble in acidic solutions and its binding properties can be used in both solid form (sorption) and liquid form (ultrafiltration coupled with chelation, coagulation–flocculation). These properties have been used for the recovery of mercury from dilute solutions at initial pH 5 (which reveals the most efficient pH in the range pH 4–6) and for the recovery of Reactive Black 5 (RB5, anionic dye) at pH 3. While in the case of mercury binding saturation of the biopolymer is only slightly higher when chitosan is used in the liquid form compared to solid-state adsorption, in the case of the coagulation–flocculation of RB5 (using the liquid-form of chitosan) the saturation of the polymer (calculated on the basis of molar ratio of dye vs. amino groups of the polymer) is reached at a significantly greater value than when the polymer is used for the solid-state binding of the dye. There is a much more efficient use of amino groups when chitosan is used in the liquid-form due to a better availability of amino groups (less hydrogen bonds between the chains of the polymer) and to a better accessibility to internal sorption sites (lower diffusion control).     

葛根素配位特性研究

本文运用配位化学的基本原理,采用pH电位滴定法,对葛根素的配位特性进行研究。结果表明在碱性条件下,葛根素结构易发生改变。在25℃和37℃,葛根素能和铜离子、锌离子、铁离子、铝离子、钙离子形成配合物。计算得出葛根素与Cu2 、Ca2 、Zn2 、Al3 、Fe2 的络合稳定常数lgK分别为3.28、2.16和1.12、2.85和1.72、2.78和1.63、2.94和1.87。     

Metal Ions,Not Metal-Catalyzed Oxidative Stress,Cause Clay Leachate Antibacterial Activity

Aqueous leachates prepared from natural antibacterial clays, arbitrarily designated CB-L, release metal ions into suspension, have a low pH (3.4–5), generate reactive oxygen species (ROS) and H₂O₂, and have a high oxidation-reduction potential. To isolate the role of pH in the antibacterial activity of CB clay mixtures, we exposed three different strains of Escherichia coli O157:H7 to 10% clay suspensions. The clay suspension completely killed acid-sensitive and acid-tolerant E. coli O157:H7 strains, whereas incubation in a low-pH buffer resulted in a minimal decrease in viability, demonstrating that low pH alone does not mediate antibacterial activity. The prevailing hypothesis is that metal ions participate in redox cycling and produce ROS, leading to oxidative damage to macromolecules and resulting in cellular death. However, E. coli cells showed no increase in DNA or protein oxidative lesions and a slight increase in lipid peroxidation following exposure to the antibacterial leachate. Further, supplementation with numerous ROS scavengers eliminated lipid peroxidation, but did not rescue the cells from CB-L-mediated killing. In contrast, supplementing CB-L with EDTA, a broad-spectrum metal chelator, reduced killing. Finally, CB-L was equally lethal to cells in an anoxic environment as compared to the aerobic environment. Thus, ROS were not required for lethal activity and did not contribute to toxicity of CB-L. We conclude that clay-mediated killing was not due to oxidative damage, but rather, was due to toxicity associated directly with released metal ions.     

金属对金属全髋关节置换术后体内金属离子对机体的影响

金属对金属全髋假体由于其具有良好的活动度因而被广泛应用全髋关节置换,但是由于金属对金属全髋假体置换术后可以产生大量的钴铬金属离子而使机体内血液尿液中金属离子水平升高,而金属离子水平升高后可能会对机体产生不利影响,本文就金属对金属全髋假体置换术后对机体的影响作一综述。     

金属对金属全髋关节置换术后体内金属离子对机体的影响

金属对金属全髋假体由于其具有良好的活动度因而被广泛应用全髋关节置换,但是由于金属对金属全髋假体置换术后可以产生大量的钴铬金属离子而使机体内血液尿液中金属离子水平升高,而金属离子水平升高后可能会对机体产生不利影响,本文就金属对金属全髋假体置换术后对机体的影响作一综述。     

免疫测定法检测重金属技术的进展

作为检测重金属的一种新型方法,免疫测定法有其特点和优势。免疫测定法的技术构成包括重金属单克隆抗体的获得、单克隆抗体灵敏性的提高和免疫检测,其中重金属单克隆抗体的获得是基础。我们对该方法进行了简要介绍,并就其所面临的一些问题和发展趋势进行了探讨。     

Carbonic Anhydrase Inhibitors. Metal Complexes of 5-(2-Chlorophenyl)-1, 3, 4-Thiadiazole-2-Sulfonamide with Topical Intraocular Pressure Lowering Properties: The Influence of Metal Ions Upon the Pharmacological Activity

Metal complexes of a sulfonamide possessing strong carbonic anhydrase (CA) inhibitory properties, 5-(2-chlorophenyl)-1, 3, 4-thiadiazole-2-sulfonamide (chlorazolamide) have been obtained from the sodium salt of the sulfonamide and the following metal ions: Mg(II), Zn(II), Mn(II), Cu(II), Co(II), Ni(II), Be(II), Cd(II), Pb(II), AI(III), Fe(III) and La(III). The original sulfonamide and its complexes were assayed for the in vitro inhibition of three CA isozymes, CA I, II, and IV, some of which play a critical role in ocular fluid secretion. All these compounds (the sulfonamide and its metal complexes) behaved as powerful inhibitors against the three investigated isozymes. The parent sulfonamide possessed an extremely weak topical pressure lowering effect when administered as a 1-2% suspension into the rabbit eye, but some of its metal complexes, such as the Mg(II), Zn(II), Mn(II) and Cu(II) derivatives, lower intraocular pressure (IOP) in experimental animals very well. Ex vivo data showed a 99.5-99.9% CA II inhibition in ocular fluids and tissues of rabbits treated with these agents, proving that the observed IOP lowering is due to CA inhibition. The influence of the different metal ions upon the efficiency of the obtained complexes as pressure lowering drugs are discussed, leading to the possibility of designing more selective; potent pharmacological agents from this class