Preparation and storage of125I labelled endothelin

Endothelin (ET) is a novel endothelium-derived vasoconstrictive peptide, purified from porcine aortic endothelial cells.¹²⁵I-ET was prepared by lodogen method and purified by HPLC, the specific activity was 62.9 TBq/mmol. The stability of¹²⁵I-ET was investigated in different storage conditions by radioimmunoassay.     

Chromatographic analysis and purification of multiply tritium-labelled eicosanoids

This is a comparative study of different chromatographic techniques [gas-liquid (GLC), thin-layer (TLC), liquid (LC), high-pressure liquid (HPLC) chromatography] as applied to the analysis and preparative purification of tritium-labelled eicosanoids with a molar radioactivity of 1.8–8.8 TBq/mmol obtained by selective hydrogenation and by chemical or enzymic methods. We demonstrate the possibility of analyzing reaction mixtures and isolating individual multiply labelled eicosanoids with a chemical and radiochemical purity of 95–98%. Special features of HPLC for high molar radioactivity eicosanoids are considered.     

Radio-gas chromatography on wide-bore capillary columns equipped with a synchronized accumulating radioisotope detector

A gas chromatographic system with wide-bore capillary columns and synchronized accumulating radioisotope detector (SARD) was developed. A direct injection method and constant-flow regulation were applied. The performance of wide-bore capillary columns was good and the correspondence of the resolution obtained with SARD and that with mass detection was excellent. It was proved that the apparatus could detect of the order of 1 pg of 3H-labelled substances (3.7 TBq/mmol) and compete in terms of sensitivity with gas chromatography-mass spectrometry.     

Design,Synthesis, and Validation of a Novel [11C]Promethazine PET Probe for Imaging Abeta Using Autoradiography

Promethazine, an antihistamine drug used in the clinical treatment of nausea, has been demonstrated the ability to bind Abeta in a transgenic mouse model of Alzheimer’s disease. However, so far, all of the studies were performed in vitro using extracted tissues. In this work, we report the design and synthesis of a novel [¹¹C]promethazine PET radioligand for future in vivo studies. The [¹¹C]promethazine was isolated by RP-HPLC with radiochemical purity >95% and molar activity of 48 TBq/mmol. The specificity of the probe was demonstrated using human hippocampal tissues via autoradiography.     

Optimized production,quality control and biodistribution assessment of <Superscript>166</Superscript>Ho–DOTATOC: a novel radiolabelled somatostatin analog

Nowadays, peptide receptor radionuclide therapy is used to treat a specific type of cancer called neuroendocrine tumors. In this research, the optimized conditions for ¹⁶⁶Ho-DOTATOC production are presented. The radiolabeled compound was prepared with the specific activity of 11.1 TBq/mmol and radiochemical purity of more than 99% (using ITLC and HPLC). Stability tests of the complex were investigated in room temperature and in human serum at 37 °C. Biodistribution studies in Syrian rats showed considerable accumulation in pancreas as the somatostatin receptor-positive tissue. ¹⁶⁶Ho-DOTATOC can be considered as a novel agent for treatment of somatostatin receptor-positive tumors.     

Study of optimum condition for synthesis of [γ-32P]ATP with high specific radioactivity

The synthesis of [γ-³²P]ATP with high specific radioactivity was investigated by the enzymatic method. We utilized a part of the glycolytic pathway which consists of three reaction steps. First, we examined the maximum radioactivity of H₃ ³²PO₄ without the decrease of labeling yield. Next, we examined the minimum amount of reagent without the decrease of labeling yield, because some reagents contain the phosphorus species as impurity. In this paper, we propose the optimum condition for synthesis of [γ-³²P]ATP with high specific radioactivity. As our calculation, we will be able to obtain about 220 TBq/mmol specific radioactivity using 1.5 GBq of H₃ ³²PO₄.     

A one-year study of the total air-borne14C effluents from two Swedish light-water reactors,one boiling water- and one pressurized water reactor

The results of a one-year study of the total air-borne¹⁴C effluents from two Swedish light-water reactors, one boiling water reactor (BWR) at Forsmark and one pressurized water reactor (PWR) at Ringhals, are presented. Air emitted from the stacks has been collected continuously over two-week periods and the¹⁴C content in the samples has been analysed using accelerator mass spectrometry (AMS). The¹⁴C activity concentration in the air issuing from the stack of the PWR varied between 2 and 1132 Bq/m³ with a mean value of 200 Bq/m³, while from the BWR the activity concentration varied between 4 and 146 Bq/m³, with a mean value of 95 Bq/m³. The corresponding¹⁴C release rate was 0.27 TBq/GW_el·year for the PWR and 0.48 TBq/GW_el·year for the BWR. During the same period of time, for comparison, the¹⁴C activity in continuously collected air from the stack of the PWR was also measured by liquid scintillation counting. In most cases the results of these measurements were in fair agreement with the corresponding AMS results.     

Ten years3H survey at the Krško Nuclear Power Plant

As part of the general off-site radioactivity monitoring at the Krško Nuclear Power Plant, tritium is measured in the water of the river Sava at two locations (one upstream reference point and downstream point of total dispersion), the inlet and discharge of the essential plant service supply water, in four borehole waters, in tap water in Krško and Bre zice, and in precipitations at four points. Since 1992 tritium has also been analysed in gaseous effluents in the exhaust stack. Tritium is electrolytically enriched and determined by a liquid scintillation technique. For liquid effluents an average normalized release of 17.6 TBq per GW_e·y was obtained, while this value for gaseous effluents is 2.3 TBq per GW_e·y.     

Analysis of serotonin in brain microdialysates using capillary electrophoresis and native laser-induced fluorescence detection

Serotonin or 5-hydroxytryptamine (5-HT) is a major neurotransmitter in the central nervous system. In this work, a method for analyzing 5-HT in brain microdialysis samples using a commercially available capillary electrophoresis (CE) system has been developed. A pH-mediated in-capillary preconcentration of samples was performed, and after separation by capillary zone electrophoresis, native fluorescence of 5-HT was detected by a 266 nm solid-state laser. The separation conditions for the analysis of 5-HT in standard solutions and microdialysates have been optimized, and this method has been validated on both pharmacological and analytical bases. Separation of 5-HT was performed using a 80 mmol/L citrate buffer, pH 2.5, containing 20 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and +30 kV voltage. The detection limit was 2.5 x 10(-10) mol/L. This method allows the in vivo brain monitoring of 5-HT using a simple, accurate CE measurement in underivatized microdialysis samples.     

新型取代胡椒醛缩合不对称卟啉金属配合物的微波合成及其抗菌活性

利用微波辐射加热方法合成了5-(3, 4-亚甲二氧基-6-硝基)苯基-10, 15, 20-三苯基卟啉和5-(3, 4-亚甲二氧基-6-硝基)苯基-10, 15, 20-三对氯苯基卟啉的Zn(Ⅱ)、Co(Ⅱ)、Mn(Ⅱ)金属配合物, 产物的结构用紫外-可见光谱、红外光谱、荧光光谱等技术手段进行了表征, 采用抑菌环方法研究了目标化合物对大肠杆菌和金黄色葡萄球菌的抗菌活性, 实验结果表明, 两个Co(Ⅱ)金属配合物在浓度为0.32 mmol/L时对Sa、Ec有较强的抑菌作用, 浓度为0.02 mmol/L时还有一定的抑菌作用;2个Zn(Ⅱ)和2个Mn(Ⅱ)配合物在浓度为0.16~0.32 mmol/L范围内对Sa、Ec有中等强度的抑菌作用。 各金属配合物的抑菌活性大小顺序大体为:Por(Co)>Por(Mn)≈Por(Zn)。 各配合物对金黄色葡萄球菌的抑制作用比大肠杆菌大约高10%~20%。     

Mobile gamma-irradiation robot

The source container with 98 TBq of ¹³⁷Cs and shielding made from depleted uranium has the total weight of 264 kg, height of 0.370 and diameter 0.272 m. The container is joined to accessories allowing movment of the radiation beam. The dose rate at a distance of 0.4 m in the beam axis is 50 Gy/h. Various technical means are available for manipulation and transport. The irradiation process proceeds according to a precalculated program.The safety measures have been taken to secure the possible application in historical buildings and similar objects. The licence from health physics authorities has been obtained. The first irradiation process performed is described.     

离子色谱法测定浴盐中的阴、阳离子

用离子色谱法测定浴盐中的Na^ 、K^ 、Mg^2 、Ca^2 、Cl^-、Br^-、SO4^2-时，分离阳离子的色谱柱为ICS-C25阳离子交换柱，淋洗液为2.0mmol/L均苯四甲酸溶液，流速为0.6mL/min；分离阴离子时的色谱柱为shim-pack IC-Al阴离子交换柱，淋洗液为2.5mmol/L邻苯二甲酸溶液－2.4mmol/L三羟基氨基甲烷溶液（体积比为1：1），流速为1.0mL/min。所测离子Na^ 、K^ 、Mg^2 、Ca^2 、Cl^-、Br^-、SO4^2-在较宽浓度范围内有良好的线性关系，回收率为94.7%-102.4%，检出限为0.001-0.02mg/L，相对标准偏差为1.03%-1.63%。     

高效液相色谱与电感耦合等离子体质谱联用技术用于胁迫富硒海带硒形态研究

通过对海带胁迫富硒培养, 研究了海带对硒的富集总量及硒化学形态转变. 建立了反相离子对缓冲盐等3个色谱系统的高效液相色谱与电感耦合等离子体质谱联用(RP-HPLC-ICP-MS)技术测定亚硒酸钠、硒甲基半胱氨酸(MeSeCys)、硒代蛋氨酸(SeMet)三种硒形态. 采用3种提取溶剂, 超声提取缩短提取时间, 分离检测富硒海带的主要硒形态为亚硒酸钠、硒甲基半胱氨酸和硒代蛋氨酸.     

Determination of noble elements in coins by gamma activation analysis

Silver and gold were analysed in coins and medals by inelastic gamma-scattering reaction. The irradiation was performed with a 740 TBq (20 kCi)⁶⁰Co source. After irradiation the isomer activities were measured with a well type NaI(Tl) scintillation counter and evaluated by means of a software program.     

Synthesis of [N-methyl-3H]-7-chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2 H-1,4-benzodiazepin-2- one (3H-fludiazepam) by phase transfer catalysis

[N-methyl-3H]-7-Chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2H-1,4- benzodiazepin-2- one ( [3H]fludiazepam) was prepared by phase transfer catalytic N-methylation of the corresponding nor-derivative with [3H]methyl iodide [407 GBq/mmol (11 Ci/mmol)] in a radiochemical yield of 34%. The specific activity was 271.6 GBq/mmol (7.34 Ci/mmol).     

高效离子交换液相色谱法分离绿脓杆菌外膜蛋白

 利用高效ＤＥＡＥ离子交换液相色谱法分离纯化了绿脓杆菌标准菌株ＰＡＯ１外膜蛋白。流动相为ｐＨ８．０Ｔｒｉｓ－ＨＣｌ缓冲液,色谱柱为ＴＳＫｇｅｌ－ＤＥＡＥ－５ＰＷ（０．７５ｃｍ×７．５ｃｍｉ．ｄ．）。通过纯化外膜蛋白,可以为研究绿脓杆菌外膜通透性与抗生素耐药性之间的关系及缩短研究周期提供有效的方法。     

Reconstructing the history of 14C discharges from Sellafield

Prior to 1984, the reported marine ¹⁴C discharges from Sellafield were estimates: 0.2 TBq per annum from 1952 to 1969 and 1 TBq per annum until 1984 when measurements commenced. The relationship between the net excess ¹⁴C activity in annually collected Nori (Porphyra umbilicalis) seaweed samples and the annual discharges (estimated and measured) implies that the discharges were not as constant as the estimates. Based on the relationship between post-1984 measured discharges and the excess ¹⁴C in the seaweed, two simple empirical models were used to re-calculate the discharges between 1967 and 1984. Gamma-spectrometry measurements on the seaweed also indicate that Porphyra is a sensitive indicator of changes in discharge of other radionuclides, brought about by the introduction of new waste clean-up technologies within Sellafield. This revised version was published online in July 2006 with corrections to the Cover Date.     

Tritium-labeled 5-oxo-Pro-Arg-Pro

Conditions of tritium introduction into 5-oxo-Pro-Arg-Pro have been developed. Labelled 5-oxo-Pro-Arg-Pro has been obtained in 75% yield and molar radioactivity of 60 Ci/mmol. Tritium distribution over amino acid residues in the peptide has been determined. 5-Oxo-Pro : Arg : Pro ratio in the labelled peptide has been found to be 1 : 5.2 : 2.8. Nonterminal amino acid has been found to contain the major portion of tritium, about 35 Ci/mmol; i.e., arginine includes more than half of the label. Such a feature can be explained by the effect of readily protonated guanidine group of arginine. The influence of charged guanidine group of arginine seems to increase the shift of electron density in the neighboring C–H bonds of arginine and proton mobility, thus increasing protium–tritium exchange at these carbon atoms.     

Protein-bound glutathione measurement in cultured cells by CZE with LIF detection

Protein modification due to S-glutathio(ny)lation, usually a reversible process in intact cells, arises interest as a possible mode of regulatory events that may potentially modify a large number of cellular processes. However, since less than 1% of the total protein is S-thiolated in resting cells, high sensitivity methods are required for its evaluation. We set up a new method by CE with LIF detection that allows to measure all forms of intracellular GSH involved in the process. For total and reduced glutathione, cell lysates were rapidly derivatized by 5-iodoacetoamidofluorescein (5-IAF), a selective reagent which traps thiol groups, thus minimizing auto-oxidation. Derivatized samples were separated in a 47 cmx75 microm id capillary by using 7 mmol/L sodium phosphate at pH 11.6. For the evaluation of S-glutathio(ny)lation, intracellular proteins from cell lysates were precipitated and washed to eliminate free GSH. After protein resuspension with NaOH and reduction treatment with tri-n-butylphosphine (TBP), the freed GSH was dried in a vacuum concentrator and directly dissolved in the derivatization mixture. GSH-IAF adduct was detected in a 6 mmol/L sodium phosphate, 3 mmol/L boric acid, and 75 mmol/L N-methylglucamine run buffer in less than 5 min. The high sensitivity ensured by 5-IAF use and sample concentration, allowed to quantify GSH at levels as low as 5 nmol/L, value suitable for the evaluation of protein S-glutathio(ny)lation. The method suitability was checked both in HUVEC and ECV304 cultured cells.