Investigation of therapeutic efficiency of phenytoin (PHT) labeled with radioactive 131I in the cancer cell lines

The aim of this study is to determine the incorporations of PHT radiolabeled with ¹³¹I (¹³¹I-PHT) on U-87 MG, Daoy and A549 cancerous cell lines. For this, cold and radio-labeling studies were carried out. The radio-labeling yield of ¹³¹I-PHT was obtained about 95 %. Subsequently, cell culture studies were carried out and radio-labeling yields of ¹³¹I, ¹³¹I-PHT on U-87 MG, Daoy and A549 cancerous cells were investigated. Cell culture studies demonstrated that the incorporation values of ¹³¹I-PHT on the three cell lines decreased with increasing radioactivity. Consequently, ¹³¹I-PHT may be a good radiopharmaceutical for targeting radionuclide therapy of Central Nervous System Tumors.     

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.     

99mTc-Exorphin-glucuronide in tumor diagnosis: Preparation and biodistribution studies in rats

Summary  Elérh     

Comparison of the radiopharmaceutical potentials of dithizone radiolabeled with 131I and with 99mTc

In this study, dithizone (diphenylthiocarbazone) has been separately radiolabeled with ¹³¹I and with ^99mTc for preliminarily testing their radiopharmaceutical potentials on male albino rabbits. ¹³¹I-dithizone and ^99mTc-dithizone were intravenously injected to rabbits via their ear veins after anesthetizing with a mixture of Alfazyne and Alfamine (Serva) to determine their dynamic and static statuses in the metabolism. Also, ^99mTc as pertechnetate and ¹³¹I as iodate were administered to rabbits as controls. Dynamic and static scintigrams were obtained using a gamma camera (Diacan Instruments). Dynamic scintigrams were obtained over the first half hour with frames of 1 minute following the administrations of the labeled compounds. Static images were obtained from posterior projection at different time intervals up to about 3 hours following the administration of the radiolabeled compounds. ^99mTc-dithizone was significantly uptaken by the pancreas in contrast to free ^99mTc. In the case of ¹³¹I-dithizone, the distribution of ¹³¹I activity in the metabolism was clearly different than the case of free ¹³¹I and the uptake of ¹³¹I-dithizone at the pancreas zone was also significant. These preliminary tests have clearly indicated that especially ^99mTc-dithizone has a significant potential to be used as a pancreatic radiopharmaceutical.     

Optical Ray Movement Inside Dielectric Sphere

The paper presents results of numerical investigations of electromagnetic (optical) ray propagation inside a sphere, made of optically uniaxial crystal. The types of caustics formed by the ray trajectory inside the sphere are cleared up. It has been demonstrated the difference between types of caustics formed by the extraordinary ray trajectory inside the sphere made of optically positive and negative crystals. Results are discussed on the basis of one-to-one mapping of 2D billiard problem inside isotropic region bounded by ellipse onto anisotropic one.     

A new approach to liquid penetrant inspection: radiolabeled QDots

Penetrant technique is a sensitive non-destructive testing (NDT) method for detecting and locating the presence of cracks in sample surface. Today, NDT is used in a wide range of industries including aerospace, biotechnology, defence, marine, oil–gas and energy plants. This work focuses on potential use of radiolabeled ZnS coated CdTe quantum dots (QDots) as a penetrant for liquid penetrant testing. The synthesized QDots as a precursor were tested for surface defects detection in welded joints. The experimental results show the highest activities were found in defects on the sample surface. These finding are consistent with the sample NDT inspection test report.     

Reactions of the transient species Cr(CO)5(cyclohexane) with C4HnE (n=4, 8; E=O, NH, S) studied by time-resolved IR absorption spectroscopy

Time-resolved IR absorption spectroscopy is used to investigate substitution of the cyclohexane (CyH) molecule of the photolytically generated alkane-solvated transient intermediate Cr(CO)5(CyH) by heterocyclic ligands C4HnE (n=4, 8; E=O, NH, S). From the concentration and temperature dependences of the pseudo-first order rate constants, we obtain activation parameters for the reactions, and find that they are consistent with an associative (A) or interchange (I) mechanism. As was the case with ligand substitution reactions at W(CO)5(CyH), a ligand's reactivity depends both on its electron-donating ability and on its polarizability. We also find that for a reaction with a given DeltaH, the activation entropy is higher for reaction of Cr(CO)5(CyH) than it is for reaction of W(CO)5(CyH). Comparison of the present results with ligand substitution reactions of W(CO)5(CyH), CpMn(CO)2(CyH), and Cr(CO)5(n-heptane) indicates that for ligand substitution reactions at alkane-solvated transition-metal intermediates, the solvent's effect upon the reaction rate is primarily entropic.     

Synthesis of a 99mTc labeled estrogen-derivative and the determination of its radiopharmaceutical potential on rats

An estrogen derivative 1-(3, 17-α-estradiolyl propin-1-yl-3-(1,4,8,11-tetraazacyclotetradecyl)-propanate (ESTACPA) was synthesized. The product was purified by HPLC and characterized by NMR and IR spectroscopy. The synthesized compound was labeled with ^99mTc. The biodistribution studies were performed on female Albino Wistar rats. The rats were sacrificed and their organs were removed. The radioactivities of the organs were counted using a gamma-counter. The activity per gram tissue was calculated and time versus activity curves were generated. The ^99mTc-ESTACPA uptake by the uterus and ovary such as ER-rich tissues, were observed. The pancreas and stomach also showed a significant uptake. This revised version was published online in July 2006 with corrections to the Cover Date.