Made available in DSpace on 2014-10-09T12:34:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:28Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:34:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:28Z (GMT). No. of bitstreams: 0 / Dentre as diversas formas de se tratar o câncer de próstata, a braquiterapia com sementes de iodo-125 é uma opção que apresenta ótimos resultados e menor ocorrência de efeito colateral. No presente trabalho diferentes métodos de deposição de iodo radioativo em substrato de prata foram comparados com o propósito de eleger a alternativa mais adequada para a produção rotineira de sementes de iodo-125 do IPEN. A metodologia utilizada foi escolhida com base na infraestrutura disponível e na experiência dos pesquisadores presentes. Por essa razão, utilizou-se o iodo-131 para realização dos testes (mesmo comportamento do iodo-125). Quatro métodos foram selecionados: Método 1 (teste de eletrodeposição baseado no método desenvolvido por D. Kubiatowicz) com a eficiência de 65,16%; Método 2 (Reação química baseada no método desenvolvido por D. Kubiatowicz - HCl) com o resultado de 70,80% de eficiência; Método 3 (Reação química baseada no método desenvolvido pela Dra Maria Elisa Rostelato aquecimento/sulfeto) com 55,80% de eficiência; Método 4 (IQ-IPEN) apresentou o melhor resultado de eficiência, 99%. Como há mais fixação do material radioativo (que representa praticamente todo o custo da semente) por esse método, o preço final é o mais barato, sendo esse o método sugerido para ser implementado no laboratório de produção de fontes de braquiterapia do IPEN. Além disso o método é o mais rápido. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

The potential use of four radioiodinated fatty acids as myocardial imaging agents were evaluated. Preliminary distribution studies revealed that the terminal labeled fatty acids demonstrated higher myocardial uptake. Thus, 10-Iodocapric acid (10-iododecanoic) and 12-Iodolauric acid were subjected to further investigation. Comprehensive tissue distribution studies involving both radioiodinated fatty acids in mice indicated that the highest accumulation of the total injected activity occurred in the muscle and the blood. Other organs investigated included the heart, liver, lung, kidneys, spleen, stomach, intestines, bone and adrenals. The heart exhibited the highest concentration of the radioiodinated fatty acids for the relative accumulation of activity per unit weight. Erom the tissue distribution studies, the optimum scanning time was found to be immediately following injection of the radiopharmaceutical. Toxicity studies were performed in mice after intravenous administration of 10-Bromocapric acid and 12-Bromolauric acid. The LD₅₀ of Sodium Bromolaurate in 10% Human Serum Albumin was found to be 210 mg/kg (194 mg/kg - 228 mg/kg). The stability problem encountered with 10-Bromocapric acid necessitated the use of a different solvent system. The LD₅₀ obtained after intravenous injection was found to be 86.1 mg/kg (83.0 mg/kg - 89.3 mg/kg). However, this observed toxicity may not necessarily reflect the toxicity of the Bromocapric acid solely. Whole body excretion studies were performed in mice and revealed a triexponential excretion curve. For 10-Iodocapric acid, the effective half-lives were .90 hours (36.7%), 3.91 hours (61.6%) and 74.9 hours (14.5%). For 12-Iodolauric acid, the effective half-lives were 1.67 hours (46.6%), 7.68 hours (38.4%), and 71.6 hours (17.8%). For both 10-Iodocapric acid and 12-Iodolauric acid, the first as well as the second component of the excretion curve presumably represented a decrease in the whole body activity due mainly to urinary excretion. The third component appeared to represent activity which was tightly bound and slowly released. The third component presumably represented elimination by fecal excretion. The excretion of the injected activity was primarily in the urine, although some activity was recovered in the feces. For 10-Iodocapric acid, 82.4% of the injected activity had been recovered in the urine within the first 24 hours and 8.88% had been recovered in the feces. For 12-Iodolauric acid, 78.9% of the injected dose was recovered in the urine at 24 hours and 9.4% in the feces. From the urine results, the effective half-life of the radio-iodinated fatty acids in the kidneys was found to be 4.8 hours. Myocardial scans were done on rabbits using ¹³¹I-capric acid, ¹³¹I-lauric acid, NaI-131 (6% Human Serum Albumin), and Thallium-201 at specified time intervals after injection. Iodine-123, a radionuclide possessing more favorable imaging properties, was not readily available due to production problems at the time of scanning. The mean absorbed dose to the whole body, the liver, the kidneys, the muscle, and the heart were computed based on the results from the distribution and excretion studies. The dosimetry calculations were done using Iodine-123 as the radionuclide. For ¹³¹I-capric acid, the radiation doses were calculated as 34.76 mrads/2 mCi for the whole body, 136.3 mrads/2 mCi for the kidneys, 86.6 mrads/2 mCi for the liver, 38.5 mrads/2 mCi for the muscle, and 25.89 mrads/2 mCi for the heart. For ¹³¹I-lauric acid, the radiation doses were 41.73 mrads/2 mCi for the whole body, 199.8 mrads/2 mCi for the kidneys, 185.9 mrads/2 mCi for the liver, 52.07 mrads/2 mCi for the muscle, and 46.39 mrads/2 mCi for the heart. / Pharmaceutical Sciences, Faculty of / Unknown

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22337号 / 医博第4578号 / 新制||医||1041(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 佐藤 俊哉, 教授 福原 俊一, 教授 鈴木 実 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Huge amounts of anthropogenic 129I have been and still are released to the environment through liquid and gaseous discharges from the nuclear fuel reprocessing facilities worldwide and in particular the ones in Europe. Most of this 129I signal has been accumulated in the marine environment which plays a major role in the iodine natural pool.  In this thesis, an overview of available 129I concentrations in waters of the oceans and marginal seas together with new data about 129I and 127I spatial distribution in surface seawater along a transect between the North Sea and the northeastern Atlantic Ocean are presented. After comprehensive chemical separation, the concentrations of iodine isotopes (127I and 129I) and their species (iodide and iodate) were analysed using accelerator mass spectrometry and inductively-coupled plasma mass spectrometry. The results show that, generally, changes in the 127I and 127I-/127IO3- are comparable to data from other marine waters which are related to natural distribution patterns. A considerable variation of 129I along the transect is observed with the highest values occurring in the eastern English Channel and relatively low values obtained in the northeastern Atlantic Ocean. Inventory estimations of 129I in the North Sea and the English Channel are 147 kg and 78 kg, respectively, where more than 90% resides in the Southern Bight and the eastern English Channel. Iodate is the dominant iodine species for both 127I and 129I in most seawater samples from the North Sea to the Atlantic Ocean. 129I species variability suggests a slow process of 129I- oxidation in the open sea. It takes at least 10 years for the 129I-/129IO3- pair to reach their natural equilibrium as the water is transported from the English Channel. The results suggest a main transport of 129I from the western English Channel via the Biscay Bay into the northeastern Atlantic Ocean. Further, high 129I/127I and distinctive 129I-/129IO3- values south of 40°N indicate possible contribution of 129I through Mediterranean Outflow Water. The environmental radioactive impact of 129I and possible applications in ecosystem studies are also discussed.

NCRP report No.160 states that medical exposure increased to nearly half of the total radiation exposure of the U.S. population from all sources in 2006 (NCRP 2009). Part of this increase in exposure is due to the rise in nuclear medicine procedures. With this observed growth in medical radionuclide usage, there is an increase in the radionuclide being released into wastewater after the medical procedures. The question then arises: what is the behavior of medical radionuclides and their impurities in the wastewater process? It is important to note that, often, medical radionuclides are not exactly 100% radionuclide pure, but they meet a certain standard of purity. Of particular interest are the longer lived impurities associated with these medical radionuclides. The longer lived impurities have a higher chance of reaching the environment. The goal of this study is to identify the behavior of medical radionuclides and their impurities associated with some of the more common radiopharmaceuticals, including Tc-99m and I-131, and locate and quantify levels of these impurities in municipal wastewater and develop a model that can be used to estimate potential dose and risk to the public. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from May 24, 2012 - May 24, 2014