Biomedical subjects

Berkan Cetinkaya

Publications and source records attributed to Berkan Cetinkaya.

3 recordsLinked to original sources

PubMed2006

Preparation of (99m)Tc labeled vitamin C (ascorbic acid) and biodistribution in rats.

The aim of this study was to label ascorbic acid with (99m)Tc and to investigate its radiopharmaceutical potential in rats. Ascorbic acid was labeled with (99m)Tc using the stannous chloride method. The radiochemical purity of [(99m)Tc]ascorbic acid ((99m)Tc-AA) was determined by RTLC, paper electrophoresis, and RHPLC methods. The labeling yield was found to be 93+/-5.0%. The maximum labeling yield of (99m)Tc-AA was determined at pH 5 and 25 degrees C. The biodistribution studies related to (99m)Tc-AA were done in male albino Wistar rats. (99m)Tc-AA, which has a specific activity of 13.02 GBq/mmol, was administered into the tail vein of the rats. The rats were sacrificed at 15, 30, 60, and 120 min after the injection by heart puncture under ether anaesthesia. The organs were weighed after removal. Their activities were counted using a Cd(Te) detector equipped with a RAD 501 count system. The %ID/g (% of injected dose per gram of tissue weight) in each organ and in blood was calculated. Maximum uptake of (99m)Tc-AA was observed in prostate and kidneys at the 60th min. (99m)Tc-AA may be a promising radiopharmaceutical for the imaging of prostate and kidneys.

Animals↗

PubMed2005

Absorbed dose estimates at the cellular level for 131I.

Microdosimetric calculations of 131I have been evaluated for a single cell and for cell clusters. A VsBasic program has been used to calculate stopping power, linear energy transfer, range values and deposited energies per decay for beta particles, Auger and conversion electrons of 131I. The chemical composition of the cell has been taken into account in this model; results were compared with water medium. Besides, total absorbed doses have been calculated for the radionuclides distributed randomly within the cell and clusters. Cross-fire irradiation has been considered for clusters of cells. In this case, absorbed doses per cell within a cluster were found to be significantly higher than absorbed doses per single cell, depending on the cluster size. Results showed that 131I is a promising radionuclide for therapy of tumors from millimeter to centimeter dimensions.

Iodine Radioisotopes↗

PubMed2003

Transfer of orally administrated iodine-131 into chicken eggs.

Radioactive iodine-131 as both as free iodide (Na131I) and covalently bound to aniline (aniline-131I) was added to the drinking water of two Leghorn laying hens as a single dose and also as a cumulative dose over 1 week. The radioactivity of the principal parts of the eggs, i.e. shell, white, and yolk, was measured, and the radioactivity levels per gram material, and percent of the total radioactivity were calculated. The radioactivity measurements were continued for 1 month following the administration of 131I. In the case of the single dose administration, the results obtained showed that about 15% of the total radioactivity administered as Na131I was transported into the egg structure; compared to only about 1% for aniline-131I. After cumulative administration, about 15% of the total administered radioactivity was transported into the egg structure with both forms of 131I. This was probably because of metabolic cleavage of iodine bonds in the labeled aniline molecules during the longer period of exposure. These results also showed considerable accumulation of 131I in the egg yolks. In the case of the single dose administration, 131I can be detected in eggs up to about 20 days after administration, and up to about 30 days, in the case of the cumulative administration over 1 week.

Administration, Oral↗