Tungsten-ethylene vinyl acetate (EVA) composite as a gamma rays shielding material

Lead is a highly toxic metal, also heavy in personal shielding. This negative aspect decline us to search for alternative shielding material that is free of toxic effect, environment friendly, lighter and easy to use individually. Polymer, being lighter, may constitute an alternative to lead, but it has a much lower density and does not serve in gamma shielding by it. Therefore, high density tungsten could be added to polymer in order to shield gamma rays. In this study ethylene vinyl acetate (EVA) and tungsten were mixed in certain amounts and thus discs have been produced from this mixture. The results show that EVA-Tungsten composite is an effective shielding material for gamma shielding

Radiotracer Techniques in the Investigation of Metabolism of Medicinal Plants

WOS: 000268493600018This work presents the importance of the use of radiotracers for metabolic studies of medicinal plants. Labeling with a radioisotope provides compounds of high specific activity. For this reason, the labeled compounds have much advantages for metabolic and pharmacokinetic studies. It also includes some study related to the use of the method

Tümör görüntüleme ajanı olarak teknesyum-99m işaretli bombesin benzeri peptid konjugasyonu; HYNIC-Litorin'in hazırlanması ve in vitro değerlendirilmesi

Birçok tümör tipinde peptid reseptörleri fazladır ve peptidlerin bu reseptörlere bağlanması hedef doku tarafından peptidin tutulumunu sağlar. Küçük hücreli akciğer kanseri, prostat, meme, mide, kolon ve pankreas kanseri gibi pek çok tümörün Bombesin/GRP reseptörlerini içerdikleri bilinmektedir. Tc-99m (Teknesyum 99m); kimyası ve görüntüleme karakteristiği (140.5 keV gama enerjisi, t1/2 = 6.01 saat) açısından görüntüleme için tercih edilen bir radyonükliddir. Bu projenin amacı, BN-benzeri peptid konjugatı: HYNIC-Q-Litorin’in farklı ko-ligandlar (EDDA ve trisin) kullanılarak 99mTc radyoizotopu ile işaretlenmesi, işaretleme koşullarının optimize edilmesi ve in vitro çalışmalar ile pankreas tümörüne karşı potansiyelinin belirlenmesidir. Yeni hazırlanan 99mTc-trisin-HYNIC-Q-Litorin ve 99mTc-EDDA-HYNIC-Q-Litorin’in radyoişaretleme koşulları; pH, ko-ligand miktarı, kalay klorür miktarı, sıcaklık ve reaksiyon süresi optimize edildi. 99mTc-trisin-HYNIC-Q-Litorin ve 99mTc-EDDA-HYNIC-Q-Litorin için radyokimyasal verimler %98.0 ± 1.7 ve %97.5 ± 2.5 olarak belirlendi. İn vitro çalışmalarda; kanser hücrelerinde 99mTc ile işaretli peptid konjugatının AR42J (sıçan pankreas tümörü), MIA-PaCa-2 (insan pankreas karsinoma) ve PanC 02.13 (insan pankreas adenokarsinoma) hücreleri ve kontrol hücre hatlarında [Hs 574.Sk (insan fibroblast) ve PSI 2 12s6 (fare fibroblast)] tutulum potansiyeli değerlendirildi. Radyoişaretli peptid konjugatının kanser hücrelerine bağlanma affinitesinin kontrol hücre grubuna göre daha yüksek ve spesifik olduğu saptanmıştır. Elde edilen sonuçlar pankreas tümörü gibi bombesin reseptör pozitif tümörlerin görüntülenmesinde kullanılacak yeni bir radyofarmasötik oluşturulmasına katkı sağlayacaktır.Various peptide receptors are over-expressed in particular tumor types and these receptors binding of peptides is supplied to uptake by target tissue. It is known that small cell lung cancers, prostate carcinomas, glioblastoma, gastric, pancreatic, colon and breast carcinomas have Bombesin/GRP receptors. 99mTc radionuclide is chosen because of its excellent chemical and imaging characteristics (140.5 keV gamma energy, t1/2 = 6.01h). The goal of this project; HYNIC-Q-Litorin was to label with 99mTc radioisotope using different co-ligands (EDDA and tricine), to optimize of its labeling conditions and evaluate of its potential to pancreatic tumor in in vitro studies. The radiolabeling conditions of newly-formed 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin; pH, amount of co-ligand, amount of stannous chloride, temperature and reaction time were optimized. Radiochemical yields for 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were found as 98.0 ± 1.7 and 97.5 ± 2.5%, respectively. In in vitro studies, the binding potential of 99mTc labeled peptide-conjugate was evaluated in AR42J (rat pancreatic tumor), MIA-PaCa-2 (human pancreas carcinoma) and PanC 02.13 (human pancreas adenocarsinoma) cell lines and control cell lines [Hs 574.Sk and PSI 2 12s6]. The binding affinity of the radiolabeled peptide-conjugate to the cancer cells was found to be higher and specific than that control cells. The results might be contribute for a new radiopharmaceutical to be used in imaging of bombesin receptor positive tumors such as pancreatic tumor

Synthesis and biological evaluation of receptor-based tumor imaging agent: Tc-99m-folate-glucaric acid

WOS: 000294790800036PubMed ID: 21782912The aim of the present study was to prepare Tc-99m-folate-glucaric acid and investigate the radiopharmaceutical potential for tumors imaging that over express folate receptor. Folate-glucaric acid was synthesized and the synthesized folate conjugate was confirmed with H-1 NMR and LC-MS/MS methods. Folate-glucaric acid was labeled with Tc-99m, and its radiolabelling efficiency was found as 96 +/- 2.0%. Biodistribution study of Tc-99m-folate-glucaric acid was carried out in vivo using two groups of female Albino Wistar rats: folate receptor (FR) saturated and unsaturated. Biodistribution study showed that Tc-99m-folate-glucaric acid indicated high uptake in folate receptor rich tissues such as breast, ovary and uterus. Therefore, Tc-99m-folate-glucaric acid shows good radiolabeling and biodistribution in FR organs, the radiolabeled conjugate is a reason potentially useful radiopharmaceutical for detection of FR-positive tumors. (C) 2011 Elsevier B.V. All rights reserved

Radiolabeling of bombesin-like peptide with Tc-99m : Tc-99m-Litorin and biodistribution in rats

WOS: 000249656100021PubMed ID: 17760415Bombesin-like peptides are related to several human cancer receptors, including small cell lung, prostate, breast, colon, and pancreatic cancers. Litorin, an amphibian bombesin peptide derivative, is found to stimulate the contraction of smooth muscle, to stimulate gastrin, gastric acid, and pancreatic secretion, and to suppress the nutriment in in vivo experiments. In the present study, litorin was labeled with 99mTc by the stannous chloride procedure. Labeling yield is 95 +/- 1.4%, as determined by radio thin layer chromatography (RTLC) and radio high performance chromatography (RHPLC). Results of in vitro studies demonstrated a high stability in serum and cysteine solutions. In vivo biodistribution was investigated with normal male Albino Wistar rats. Biodistribution data showed fast clearance, low intestinal accumulation, and significant uptake in bombesin/gastrin releasing peptide (BN/GRP) receptor rich tissues such as the pancreas (23.56 +/- 0.01 %ID/g 30 min pi). It can be blocked partially by previous administration of 'cold' litorin. The results showed specificity of the uptake. As Tc-99m-litorin displays good radiolabeling and biodistribution, it is a potentially useful radiopharmaceutical for detection of bombesin receptor-expressing cancers