Yazar "Lambrecht, F. Yurt" seçeneğine göre listele
Listeleniyor 1 - 14 / 14
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Biodistribution of (99m)technetium-labeled creatinine in healthy rats(Assoc Bras Divulg Cientifica, 2007) Yilmaz, O.; Lambrecht, F. Yurt; Soylu, A.; Durkan, K.; Kavukcu, S.The distribution of creatinine, one of the toxic guanidine compounds, in various tissues has not been studied in detail by using radiolabeled creatinine. Our objective was to investigate the biodistribution of creatinine labeled with (99m)technetium (Tc-99m) by the stannous (II) chloride method in healthy male Wistar rats. Quality controls were carried out by radio thin layer chromatography, high- performance liquid chromatography, and paper electrophoresis. The labeling yield was 85 +/- 2% under optimum conditions (pH 7 and 100 mu g stannous chloride). Rats (N = 12) were injected intravenously with Tc-99m-creatinine and their blood and visceral organs were evaluated for Tc-99m-creatinine uptake as percent of the injected dose per gram wet weight of each tissue (% ID/g). The lowest amount of uptake was detected in the brain and testis. When the rate of uptake was evaluated, only the kidney showed increasing rates of uptake of Tc-99m-creatinine throughout the study. Kidneys showed the highest amount of uptake throughout the study (P < 0.001 compared to all other organs), followed by liver, spleen and lung tissue.Öğe Biological distribution of iodo-allyl gabapentin and iodo-gabapentin(Springer, 2008) Akat, H.; Yildirim, Y.; Lambrecht, F. Yurt; Yilmaz, O.; Balcan, M.; Duman, Y.Gabapentin (GBP) is an anticonvulsant and is widely used in the treatment of epilepsy. In this study, GBP and an allyl derivative of GBP were radioiodinated with I-131 using the iodogen method; then their radiopharmaceutical potential in rats and rabbits was investigated. The radiochemical purity of I-131-GBP and its derivatives was determined by RTLC. The labeling yield was 95 +/- 2%. Biological evaluation was performed in normal rats and rabbits. Labeled compounds were intravenously injected into two rabbits via the ear vein after anesthetizing. The dynamic and static scintigrams were obtained using a gamma camera at different time. Then the labeled compounds were administered intravenously into the rats. The distribution was studied by counting the radioactivity in the removed organs. The results of biodistribution in the rats showed the clearance of I-131-ALGBP was faster than I-131-GBP. On the other hand, the uptake of I-131-ALGBP in the brain was higher than I-131-GBP at 60 minutes.Öğe Evaluation of 99mTc-Cefuroxime axetil for imaging of inflammation(Springer, 2007) Lambrecht, F. Yurt; Yilmaz, O.; Uenak, P.; Seyitoglu, B.; Durkan, K.; Baskan, H.Öğe Extraction, radiolabeling, and biodistribution of thebaine in rats(Springer Birkhauser, 2013) Enginar, H.; Unak, P.; Lambrecht, F. Yurt; Muftuler, F. Zumrut Biber; Seyitoglu, B.; Yurt, A.; Yolcular, S.; Medine, E. I.; Bulduk, I.The goal of this study was to determine the radiopharmaceutical potential of radioiodinated thebaine. Thebaine was extracted from dry capsules of opium poppy (Papaver somniferum L.), purified using high-performance liquid chromatography, and characterized with nuclear magnetic resonance and infrared spectroscopy. The purified thebaine was labeled with I-131 using the iodogen method. Normal and receptor-blockage biodistribution studies were performed in male Albino Wistar rats. The results of the tissue distribution studies showed that the uptake of I-131-thebaine in the stomach, large intestine, spinal cord, and prostate was higher than in the other tissues. A greater uptake of radiolabeled thebaine in the rat brain was observed in the midbrain and hypothalamus. We concluded that (1) the labeling yield of I-131-thebaine was high, (2) a large amount of I-131-thebaine remained in the midbrain and hypothalamus, and (3) I-131-thebaine had enough stability for diagnostic scanning.Öğe In vitro evaluation of apoptosis detection by Tc-99m-tetrofosmin in MCF-7 breast cancer cell line(Springer, 2011) Tabar, E. Bayrak; Lambrecht, F. Yurt; Gunduz, C.; Yucebas, M.Radiolabeled molecules have an important role to evaluate tumor characteristics such as aggressiveness, and to identify the effectiveness of cancer treatments such as chemotherapy and radiotherapy. Various radionuclide (F-18, Tc-99m, I-124) labeled molecules can be used apoptosis detection by estimating decrescendos cell viability after therapy. Tc-99m-tetrofosmin which is used as a myocardial perfusion imaging agent in routine and at the same time is known to accumulate in various tumors including breast tumor. The aim of this study was to assess the utility of Tc-99m-tetrofosmin for monitoring the early response of MCF-7 breast cancer to chemotherapy. To evaluate the role of Tc-99m-tetrofosmin in vitro chemotherapy, the uptake ratio was determined using MCF-7 breast cancer line after the cells had been treated with cisplatin. When we examined the apoptotic ratios which induced with different dose of cisplatin in MCF-7 breast cancer cells by using Annexin V and TUNEL methods, it was observed that the rate of apoptosis increased with soaring dose. The uptake rates of Tc-99m-tetrofosmin in MCF-7 cell line in the chemotherapeutic groups were lower than it is in the control group (p < 0.01). The negative correlation between uptake ratios and apoptotic rates shows that Tc-99m-tetrofosmin may be used a radiopharmaceutical for evaluating chemotherapy response. Tc-99m-tetrofosmin might be probably useful as an imaging agent for estimation of early chemotherapy response in breast cancer.Öğe Iodine measurements by isotope dilution analysis in drinking water in Western Turkey(Springer, 2007) Uenak, P.; Lambrecht, F. Yurt; Biber, F. Z.; Darcan, S.This study was designed to evaluate iodine concentrations in drinking water samples using isotope dilution analysis (IDA) in the Aegean region of Turkey A total of 76 drinking water samples from rural and urban areas in regional cities were analyzed. The mean iodine concentration was 78 +/- 27 mu g/l and iodine concentration ranges were within 69 +/- 26 mu g/l and 103 +/- 6 mu g/l.Öğe Labeling bombesin-like peptide with Tc-99m via hydrazinonicotinamide: description of optimized radiolabeling conditions(Springer, 2010) Lambrecht, F. Yurt; Durkan, K.; Bayrak, E.Bombesin (BNN)-like peptides have very high binding affinity for the gastrin-releasing peptide (GRP) receptor. The goal of the current study was to optimize the labeling conditions of a new Tc-99m-radiolabeled BNN-like peptide based on the bifunctional chelating ligand HYNIC using different co-ligands (EDDA and tricine). The radiolabeling conditions (pH, amount of co-ligand, amount of stannous chloride, temperature and reaction time) for newly-formed Tc-99m-tricine-HYNIC-Q-Litorin and Tc-99m-EDDA-HYNIC-Q-Litorin were optimized and evaluated by RHPLC and RTLC. Radiochemical yields for Tc-99m-tricine-HYNIC-Q-Litorin and Tc-99m-EDDA-HYNIC-Q-Litorin were 98.0 +/- A 1.7 and 97.5 +/- A 2.5%, respectively. When EDDA was used as co-ligand, the labeling of Tc-99m-EDDA-HYNIC-Q-Litorin was optimal in the following reaction mixture: HYNIC-peptide: EDDA: 10 mu g/5 mg, pH 3, SnCl2 concentration: 12 mu g/0.1 mL, reaction temperature: 100 A degrees C, reaction time: 15 min. Besides, the optimum conditions were HYNIC-peptide:tricine: 10 mu g/50 mg, pH 5, SnCl2 concentration: 12 mu g/0.1 mL, reaction temperature: 100 A degrees C, reaction time: 15 min for preparing Tc-99m-tricine-HYNIC-Q-Litorin. The manufactured Tc-99m-HYNIC-Q-Litorin conjugates may offer new possibilities for imaging cancer cells expressing bombesin receptors.Öğe Labeling of apigenin with I-131 and bioactivity of I-131-apigenin in male and female rats(Springer, 2009) Seyitoglu, B.; Lambrecht, F. Yurt; Durkan, K.Apigenin (4',5,7-trihydroxyflavone), one of the most common flavonoids, has been shown to possess a variety of biological activities including tumor growth inhibition and chemopreventation. In the present study, apigenin was labeled with I-131 using iodogen method and investigated of its bioactivity. Radiolabeling yield is 98 +/- 0.2%, as determined by radio thin layer chromatography (RTLC), electrophoresis and radio high performance liquid chromatography (RHPLC). Besides, structure analysis of synthesized cold iodoapigenin complex were assessed with LCMS/MS and H-1-NMR. Results of in vitro study indicated a high stability (3 hours) in human serum. Biodistrubition studies are performed in male and female albino Wistar rats. Biodistribution data related to the male rats showed significant uptake in the small intestine. The female rats biodistribution results indicated that the uptake of I-131-apigenin was high in the intestine and uterus.Öğe Preparation and biodistribution of [I-131]linezolid in animal model infection and inflammation(Springer, 2009) Lambrecht, F. Yurt; Yilmaz, O.; Durkan, K.; Unak, P.; Bayrak, E.Linezolid is the first of new class of antibiotics, the oxazolidinones, and exhibits activity against many gram-positive organisms, including vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, and penicillin-resistant Streptococcus pneumoniae. Aim of the study: Linezolid was to label with I-131 and potential of the radiolabeled antibiotic was to investigate in inflamed rats with S. aureus ( S. aureus) and sterile inflamed rats with turpentine oil. Linezolid was labeled with I-131 by iodogen method. Biodistribution of [I-131] linezolid was carried out in bacterial inflamed and sterile inflamed rats. Radiolabeling yield of [I-131] linezolid was determined as 85 +/- 1% at pH 2. After injecting of [I-131] linezolid into bacterial inflamed and sterile inflamed rats, radiolabeled linezolid was rapidly removed from the circulation via the kidneys. Binding of [I-131] linezolid to bacterial inflamed muscle (T/NT = 77.48 at 30 min) was five times higher than binding to sterile inflamed muscle (T/NT = 14.87 at 30 min) of rats. [I-131] linezolid showed good localization in bacterial inflamed tissue. It was demonstrated that [I-131] linezolid can be used to detect S. aureus inflammation in rats.Öğe Preparation and biodistribution of [I-131]linezolid in animal model infection and inflammation(Springer, 2009) Lambrecht, F. Yurt; Yilmaz, O.; Durkan, K.; Unak, P.; Bayrak, E.Linezolid is the first of new class of antibiotics, the oxazolidinones, and exhibits activity against many gram-positive organisms, including vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, and penicillin-resistant Streptococcus pneumoniae. Aim of the study: Linezolid was to label with I-131 and potential of the radiolabeled antibiotic was to investigate in inflamed rats with S. aureus ( S. aureus) and sterile inflamed rats with turpentine oil. Linezolid was labeled with I-131 by iodogen method. Biodistribution of [I-131] linezolid was carried out in bacterial inflamed and sterile inflamed rats. Radiolabeling yield of [I-131] linezolid was determined as 85 +/- 1% at pH 2. After injecting of [I-131] linezolid into bacterial inflamed and sterile inflamed rats, radiolabeled linezolid was rapidly removed from the circulation via the kidneys. Binding of [I-131] linezolid to bacterial inflamed muscle (T/NT = 77.48 at 30 min) was five times higher than binding to sterile inflamed muscle (T/NT = 14.87 at 30 min) of rats. [I-131] linezolid showed good localization in bacterial inflamed tissue. It was demonstrated that [I-131] linezolid can be used to detect S. aureus inflammation in rats.Öğe Preparation of 131I-Pyrimethamine and Evaluation for scintigraphy of experimentally Toxoplasma gondii infected rats(Springer, 2012) Lambrecht, F. Yurt; Inceboz, Tonay; Surucu, E.; Yilmaz, O.; Yavasoglu, A.; Durkan, K.; Baykara, B.; Bekis, R.; Uner, A.Öğe Preparation, quality control and stability of Tc-99m-cefuroxime axetil(Springer, 2008) Lambrecht, F. Yurt; Durkan, K.; Unak, P.Cefuroxime axetil, a cephalosporin antibiotic used to treat bacterial infections, was investigated to label with Tc-99m. Radiolabeling of cefuroxime axetil was carried out by using stannous chloride method. Effects of pH and stannous chloride amount on the radiolabeling yield were investigated. The radiochemical purity of Tc-99m-cefuroxime axetil was determined by thin layer radio chromatography (TLRC), electrophoresis and high performance liquid chromatography. The maximum radiolabeling yield was 98 +/- 1%.Öğe Technetium-99m labeled Mebendazole and Biodistribution in experimentally Trichinella spiralis-infected rats(Springer, 2009) Inceboz, T.; Lambrecht, F. Yurt; Yilmaz, O.; Kaya, G. Capa; Kolatan, E.; Durkan, K.; Bagriyanik, A.; Uner, A.Öğe Technetium-99m labeled Mebendazole and Biodistribution in experimentally Trichinella spiralis-infected rats(Springer, 2009) Inceboz, T.; Lambrecht, F. Yurt; Yilmaz, O.; Kaya, G. Capa; Kolatan, E.; Durkan, K.; Bagriyanik, A.; Uner, A.
