F. Yurt

Detecting inflammation with 131I-labeled ornidazole.

The aim of this study was to demonstrate the accumulation of 131I-labeled ornidazole (131I-ORN) in experimental abscesses. 131I-ORN was prepared by electrophilic radioiodination of ORN, using radioiodide in the presence of Iodogen. An in vivo inflammation model was prepared by intramuscular injection of turpentine into the thigh of rabbits. Four days later 131I-ORN was intravenously administered to rabbits. Serial scintigrams were performed at different periods, using a Sophy DX Gamma Camera. 131I-ORN was visualized at 10 min after injection. 131I-ORN was also administered intraperitoneally to rats with turpentine-induced inflammation, for quantitative biodistribution studies. Counts of selected tissues were taken by a NaI(Tl) scintillation detector (gamma counter) after rats were decapitated. The target-to-non-target muscle ratios were 2.5, 2.6, 2.9 and 1.9 at 1, 3, 5 and 24 h, respectively.

Stability of Iodine Content in Iodized Salt

Abstract Iodization of consumed salts is mandatory in many countries fighting against to iodine deficiency. In salts iodine stability is affected by storage conditions. In this study, stabilization of iodine in salt has been determined by using Isotope Dilution Analysis. Heating, heating with oxidizing agent, incubation by time were the parameters which have been determined. Iodine loss was 41.16% by heating at 200°C up to 24 hours. When the iodized salt heated with oxidized agent iodine loss rose up to 58.46% in 24 hours. Iodine loss mechanism seems similar in both cases. However iodine loss is greater in the presence of H2O2. After the salt was stored at room temperature with a relative humidity of 30%–45% and in sealed paper bags for three years, 58.5% of iodine content lost in approximately 3.5 years.

New radiolabeled CCK-8 analogues [Tc-99m-GH-CCK-8 and Tc-99m-DTPA-CCK-8]: preparation and biodistribution studies in rats and rabbits

The aim of this study is to label CCK-8 with Tc-99m and to investigate its radiopharmaceutical potential. CCK-8 was labeled with Tc-99m using GH and DTPA as bifunctional chelating agents. Labeling efficiency was higher than 99%. Complex was stable more than 5 hours at room temperature. 37 MBq Tc-99m-GH-CCK-8 or Tc-99m-DTPA-CCK-8 was administered intravenously to rabbits for biodistribution experiments. Dynamic and static images were obtained from anterior projection using a Camstar XC/T gamma camera. For quantitative evaluation, regions of interest were drawn on organs and time-activity curves were generated. The highest accumulation occurred in brain within 10 and 30 minutes after injection. Renal and hepatobiliary excretion were observed. Brain distribution studies in rats showed the highest activity was in hypothalamus. Results demonstrated that Tc-99m-GH-CCK-8 and Tc-99m-DTPA-CCK-8 analogs may be a useful new class of receptor-binding peptides for diagnosis and therapy of brain diseases related with CCK-B receptor-expressing tumors.

Determination of iodide in drinking water by isotope dilution analysis

The most suitable way of determination iodine-deficiency is to measure iodine concentrations in water and urine. For this reason, a method that can determine iodide concentrations in drinking water and suitable for routine analysis, is developed. Water samples have been collected from four Aegean localities: Izmir, Salihli, Ödemis and Tire situated in the western Turkey. The method is based on substochiometric isotope dilution analysis. Iodile concentrations vary within 9.86–85.14 μg/l ranges in the analyzed samples. Mean value is 44.92±22.07 μg/l.

Investigation of in vitro PDT activities of zinc phthalocyanine immobilised TiO2 nanoparticles

Phthalocyanines (Pcs) are commonly used as Photosensors (PSs) in Photodynamic Therapy (PDT) applications due to their intense absorption in the far red-near IR spectral region with a high extinction coefficient and high ability for generating singlet oxygen. Pcs targetspecifically tumors, and do not show any considerable toxic effects under the absence of light. In particular, their chemical versatility has allowed the introducion a number of substituent at the periferal or axial positions which provide modulating photophysical properties, increases the solubility of these compounds in organic solvents. Nanoparticles increase the bioavailability, stability, and transport of PSs to target tissue. TiO2 nanoparticles are prefered in these applications because of their non toxic, low cost and high chemical stability properties. In our study, a Zinc Phthalocyanine (ZnPc) was used as a photosensor. The design of ZnPc integrated TiO2 nanoparticles is intended to make PSs a more effective PDT agent. With the aim to examine the nuclear imaging/treatment potentials of ZnPc and ZnPc-TiO2 in hepatocellular carcinoma (HepG2), colorectal adenocarcinoma (HT29) tumor and human healthy lung (WI38) cell lines in vitro study ZnPc and TiO2-ZnPc were also labeled with 131I. It is determined that 131I-ZnPc-TiO2 nanoparticle show a potential as an agent for the imaging/treatment of hepatocellular cancer by in vitro. The toxicity studies revealed that TiO2 nanoparticle decreases the toxicity of ZnPc. In vitro PDT results show that TiO2-ZnPc has a potential as a PDT agent in colon tumor treatment. Consequently, synthesized ZnPc and ZnPc-TiO2 could be promising candidates as theranostic agents.

An oestrogen-derivative labeled with 99mTc and its radiopharmaceutical potential

An oestrogen derivative 3,17-a-oestradiolyl propyl 1,4,8,11-tetraazacyclotetradecanyl-1-(4-methylbenzoic acid)ester (ESTCPTA) that is 3,17-a-oestradiolyl propinol coupled to 1-(4-methylbenzoic acid)1,4,8,11-tetraazacyclotetradecane (CPTA) was synthesized in five steps. The product was purified by recrystallization in ethyl alcohol, and analysed by NMR and IR spectroscopy. ESTCPTA was labeled with 99mTc and radio thin layer chromatography (RTLC) and radio-paper electrophoresis were used to determine the radiochemical yields. Specific activity was approximately 23.7 GBq/mmol and the labeling yield was over 95%. The biodistribution studies were performed on female Albino Wistar rats. The rats were sacricified by ether narcotization at certain time intervals and the activity of the organs was counted by a gamma counter. The activity per gram tissue was calculated and time activity curves were generated.

DETERMINATION OF IODIDE IN COMMON SALTS CONSUMED IN TURKEY BY ISOTOPE DILUTION ANALYSIS

Iodide traces in common salts consumed in Turkey have been determined by isotope dilution analysis. Iodide was precipitated by stoichiometric amount of AgNO3. Iodide-131 was used as tracer. Electrophoresis was performed to separate Ag131I from excess131I−. Zone of Ag131I was cut off electrophoresis paper and counted with a NaI(Tl) scintillation counter. Count rates were plotted versus added KI concentrations. Unknown iodide amounts were found by using these linear plots. Iodide concentrations found in analyzed salts were 9–58 μg/g.

Labeling of ornidazole with iodine-131

Ornidazole (1-(3-chloro-2-hydroxypropyl)-2-methyl-5-nitroimidazole) was labeled with iodine-131 by using iodogen method. Quality controls were performed by instant thin layer chromatography (ITLC) and electrophoresis methods. Labeling yield was 91%. Iodination was carried out by substitution of chloride by iodine-131. Structure was confirmed by1H-NMR.

Labeling of diazepam with iodine-131

Diazepam, which aims at benzodiazepine receptors and can be used as a specific SPECT agent has been labeled with [131I]2-iododiazepam (2-IDZ) was obtained in 50% HCl medium and [131I]2′-iododiazepam (2′-IDZ) was prepared by the iodogen method. The products were purified by passing through a Dowex-1 anion-exchange column.

Preparation of L-asparagine complex of technetium-99m

Various methods were experimented to obtain complex of L-asparagine with99mTc. The VII state of Tc was reduced with direct reduction by SnCl2 and complex compound could not be obtained. For this reason, ligand exchange with99mTc-gluconate complex was tried and 20% yield was obtained.99mTc-pyrophosphate complex was carred out as second ligand exchanger and 50% yield was obtained in this experiment. Optimum conditions for ligand exchange with pyrophosphate are pH 11,50°C temperature, 60 minutes for reaction time and 278: 1 for pyrophosphate concentration to SnCl2 ratio.