[en] Accidental internal contamination of humans by uranium can induce radiological or chemical toxicity, their relative importance being dependent on the isotopic composition. The current approach for reducing the risk of biological effects is to administer chelating agents that will enhance the excretion of uranium. The results obtained with several phosphorus bearing compounds including phosphonic acids, diphosphonates, and phosphoalkylphosphates and with 3,4,3-LIHOPO, an effective agent for other actinides are presented here. The development of new approaches designed to optimise the decorporation of uranium carried out under the European Union Fourth Framework Program is described. (author)

[en] The article summarizes the biological importance of iron in the organism, primary and secondary causes of iron overload, complications in function of liver, heart and endocrine organs due to overload of iron, the pathophysiology of iron overload, transfusion risks associated with the iron overload, assessment of risk groups of patients suitable for chelation treatment fulfilling the indication criteria, treatment modalities of chelation therapy and its significance regarding the prevention and treatment effectiveness. (author)

[en] The ternary complex formation of metal ions with ligand in an aquatic solution has been of interest in various research fields such as synergistic extraction, spectrophotometry, spectrofluorometry, solubility and sorption of radionuclides in an environment. When the metal ion extraction based on its formation of a ternary complex with two additives shows much higher extraction efficiency as compared to the extractions by an individual additive, it is classified as a synergistic extraction. Synergistic extraction uses a neutral donor in combination with an acidic chelating ligand. The chelating ligand neutralizes the charge of a metal ion to form an uncharged extractable complex having sites for water molecules, which can be replaced by the neutral donors to form an organophilic adduct. The most common acidic chelating ligands are β-diketones or organophosphorous acids, and neutral donors are amine derivatives or organophosphorous compounds such as alkylphosphates and alklypohsphine oxides. Development of sensitive and selective analytical instruments such as ICP-AES and ICP-MS makes an analyst be free from the trouble to separate analyte. However, sometimes, the removal of matrix from an analyte is required to increase sensitivity and to decrease background level and hysteresis of an instrument. Solvent extraction is one of the most important techniques in concentration and purification of U(VI). The purpose of this study is an understanding of a ternary complex formation of U(VI) in the presence of pyridine derivatives and TBP. The solvent extraction technique was used, and the results was explained by a stability of U(VI)-chelating ligand complexes. The result of this study could be applied to the concentration and separation of U(VI) from the sea water

[en] The methods and results of laboratory experiment dealing with the properties of foams and their application to the decontamination of surfaces within the controlled zone of nuclear power plants are described. Experiments were carried out with selected specimens of materials commonly encountered within the controlled zone of the plant, such as stainless steel plates, epoxy paint, epoxy concrete and plastic floorings. The foams were generated by using laboratory and technological equipment. (author)

[en] During the past decade, many bifunctional chelating agents (BFCAs) have been studied, synthesized and used for radiopharmaceuticals especially for labeling of antibodies and regionally selective drugs. General researches for preparation of DTPA derivatives have been performed using cyclic DTPA dianhydride. Because one or two carboxylic groups of DTPA were used to conjugate with biomolecule results to lower chelating power for radionuclides. Our goal was to synthesize new bifunctional chelating agents for their application in development of new medical imaging and therapeutic agents. To obtain more effective new chelating agents, we focused on the development of DTPA derivatives whose original functional groups are intact. In our study, we described the synthesis of a DTPA analogue derived from lysine

No abstract available

[en] In vitro experiments have been performed to elucidate the mechanisms by which chelators remove the radionuclides from the body. In the first part of this large-scale study, experiments have been performed to understand why the recommended chelators, DTPA and NaHCO₃, are ineffective for neptunium and uranium decorporation. Blood, liver and bone were isolated either after in vivo or in vitro contamination and the effect of various concentrations of DTPA or NaHCO₃ were tested for the dissociation of the biological complexes. The results showed that DTPA and NaHCO₃ were ineffective both in preventing the organ deposition of the neptunium and uranium and in removing them from the target organs. Other studies using sodium citrate of 3,4,3-Li-HOPO showed better efficiency than that observed with the recommended chelators. (author)

[en] For radiopharmaceutical development, many bifunctional chelating agents (BFCAs) have been synthesized and applied. Among them, EDTA(Ethylenediamine tetra-acetic acid) and DTPA(Diethylenetriamine penta-acetic acid) have been used for the radiolabeling with lanthanide nuclides. Until now, many of researches are applying the cyclic DTPA dianhydride to introduce DTPA chelator to bioactive molecules. However, its inherent disadvantage is that DTPA dianhydride produces major side product DTPA bis-molecules, which may cause instability of radionuclide binding in-vivo. In this study, in order to develop the DTPA based bifunctional chelator for the radiolabeling with radionuclides including Re-188, In-111, Y-90, Ho-166, Lu-177 and so on, we prepare lysine-based DTPA derivative. We describe, herein, the convenient synthetic method of the lysine based DTPA derivative derived from Nε - Z protected lysine

[en] Recent progress in the filed of transition-metal mediated C-H bond activation has had a great influence on organic synthesis. Among such transition-metal catalyzed reactions, ortho-functionalization via the chelationassisted strategy has been paid great attentions as one of the powerful methodologies for converting aromatic compounds into ones that are more functionalized at the exclusively ortho-position. In this context, various transition metal-catalyzed ortho-functionalizations such as alkylation, alkenylation, silylation and carbonylation are described briefly and their prospects are suggested

[en] Radioimmunoimaging depends upon the use of proteins (generally antibodies) labeled with radioisotopes. A method for radiolabeling is to use proteins covalently modified with metal-chelating groups, a method with added flexibility in the chemical reactions involved, the choice of radioisotope, and the time of addition of the radionuclide. The development of a variety of 'bifunctional' chelating agents, which form stable protein conjugates and bind metal ions very tightly, has made this type of imaging a practical technique. This article considers the general methodology involved in this type of radiolabeling and the potential for application of this methodology to immunoimaging. (Auth.)