Fikriye Gül Gümüşer

Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with 131I

The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with (131)I ((131)I-APH and (131)I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with (131)I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of (131)I-APH and (131)I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as (125)I, (123)I and (124)I as imaging and therapeutic agents in nuclear medical applications.

Metabolic comparison of radiolabeled bleomycin and bleomycin-glucuronide labeled with 99mTc.

The metabolic comparison of bleomycin (BLM) and bleomycin-glucuronide (BLMG) radiolabeled with (99m)Tc ((99m)Tc-BLM and (99m)Tc-BLMG, respectively) has been investigated in this study. Quality control procedures were carried out using thin-layer radiochromatography and high-performance liquid chromatography. To compare the metabolic behavior of BLM and its glucuronide conjugate radiolabeled with (99m)Tc, scintigraphic, and biodistributional techniques were applied using male New Zealand rabbits and Albino Wistar rats. The results obtained have shown that these compounds were successfully radiolabeled with a labeling yield of about 100%. Maximum uptakes of (99m)Tc-BLM and (99m)Tc-BLMG metabolized as N-glucuronide were observed within 2 hours in the liver, the bladder, and the spinal cord for (99m)Tc-BLM and the lung, the liver, the kidney, the large intestine, and the spinal cord for (99m)Tc-BLMG, respectively. Scintigraphy and biodistributional studies performed on the experimental animals have shown that radiopharmaceutical potentials of these compounds are completely different. At the same time, uptake of the (99m)Tc-BLMG was found to be better than that of (99m)Tc-BLM.

Investigation of Therapeutic Efficiency of Bleomycin and Bleomycin-Glucuronide Labeled with 131I on the Cancer Cell Lines

The aim of this study is to determine the incorporations of radiolabeled bleomycin ((131)I-BLM) and bleomycin-glucuronide ((131)I-BLMGLU) on PC-3 (human prostate carcinoma cell line), Caco-2 (human colon adenocarcinoma cell line), Hutu-80 (Human Duodenum adenocarcinoma cell line), and A549 (Human lung adenocarcinoma epithelial cell line) cancerous cell lines. For this purpose, BLM and BLMGLU enyzmatically synthesized were labeled with (131)I, quality control studies were done and the incorporation yields of (131)I-BLM and (131)I-BLMGLU on these cell lines were measured. Quality-control studies showed that the radiolabeling yields were obtained as 95% and 90% for (131)I-BLM and (131)I-BLMGLU, respectively. Also, as a result of the cell culture studies, it was found that (131)I-BLM and (131)I-BLMGLU had higher incorporation on PC-3 cells than that of other cell lines. In addition to this, it was reported that the incorporation yield of (131)I-BLMGLU was higher than that (131)I-BLM. At the end of the study, cytotoxicities of BLM and BLMGLU on PC-3 cancerous cell line were inspected and fluorescent images of BLM and BLMGLU were taken on PC-3 cells by using fluorescein isothiocyanate. In conclusion, cell culture studies demonstrated that the incorporation values of (131)I-BLMGLU on the four cell lines were about five to six times higher than (131)I-BLM. Radiolabeled glucuronide derivatives can be used in cancer therapy and tumor imaging, depending on the properties of radioiodine for the β-glucuronidase-rich tissues because glucuronidation leads to rapid and higher incorporation on adenocarcinoma cells.

Assessment of alveolar epithelial permeability in Behçet’s disease with 99mTc-DTPA aerosol scintigraphy

ObjectiveBehçet’s disease (BD) is a multisystem disorder characterized by vasculitis, and consists of a triad of recurrent ulcers of the oral and genital mucosa with relapsing uveitis. The prevalance of pulmonary involvement varies in the range of 1–10% in various studies and its complications are severe and life threatening. In this study, we investigated the changes of pulmonary epithelial permeability of patients with BD using technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) aerosol scintigraphy, so as to begin the therapy regimen as soon as possible.MethodsTwenty-one nonsmoking patients with BD (8 women, 13 men; mean age 38.67 ± 8.86 years) and 15 healthy volunteer nonsmoking controls (8 women, 7 men; mean age 50.87 ± 12.45 years) underwent 99mTc-DTPA aerosol inhalation scintigraphy and pulmonary function tests (PFTs). Subjects inhaled 1480 MBq of 99mTc-DTPA for 4 min in the supine position. Scintigraphic data were recorded dynamically (1 frame/min) in the posterior projection on a 64 × 64 matrix for a 30-min period using a double-headed gamma camera (Infinia, GE, Tirat Hacarmel, Israel) equipped with a low-energy all-purpose parallel hole collimator. Half time of 99mTc-DTPA clearance (T1/2) was calculated by placing a mono-exponential fit on the curves. Penetration index (PI) was also calculated by dividing the peripheral total counts by the sum of the peripheral and central total counts on the first minute image, in order to quantify the distribution of the inhaled aerosol.ResultsThe clearance half time of 99mTc-DTPA radioaerosols in the BD patients (24.81 ± 6.22 min) was faster than in the normal control group (46.53 ± 22.41 min) (P = 0.004). There was also a significant difference between PI of the patients with BD (0.15 ± 0.03) and that of the controls (0.21 ± 0.06) (P = 0.002). No correlation was found between the mean T1/2 values of 99mTc-DTPA clearance or the spirometric measurements in the BD patients. Penetration indices were not correlated with PFT in the BD patients.ConclusionsLung epithelial permeability of the patients with BD was significantly higher than that of the normal subjects. The results of this study demonstrated that the assessment of lung epithelial permeability using 99mTc-DTPA aerosol scintigraphy could predict the presence of lung involvement in the early stages of BD.

Radiosynthesis and biodistribution of 99mTc-Sulfamethoxazole: a novel molecule for in-vivo infection imaging

The aim of this study was to prepare 99mTc-Sulfamethoxazole complex and evaluate its efficiency as an infection imaging agent. The Sulfamethoxazole was labeled with 99mTc and its biological efficacy as a potential radio tracer for Staphylococcus aureus infection was investigated in bacterially infected Albino Wistar rats. The radiolabeling yield was found to be 95 ± 3.07% and remained constant at more than 93 ± 0.1% even in serum for 240 min after radiolabeling. 99mTc-Sulfamethoxazole prepared with high yield localized well in the bacterially infected muscle of the rats. 99mTc-Sulfamethoxazole may be developed as a radiopharmaceutical agent to distinguish infection from inflammation by nuclear imaging.