RESUMO
Rat amylin differs from human amylin (hIAPP) in that it lacks a fibril-forming capacity. As a consequence, toxic effects have been reported for human but not for rat amylin. This report demonstrates how a mercury contamination of commercial rat amylin imitates peptide-related vasoactive and cytotoxic effects on preparations of isolated blood vessels. The source of mercury contamination was believed related to the peptide synthesis. Thiol groups of cysteine-containing peptides are often protected by acetamidomethyl (Acm) which is cleaved by mercuric acetate.
Assuntos
Amiloide/farmacologia , Antiulcerosos/farmacologia , Mercúrio/metabolismo , Artéria Pulmonar/efeitos dos fármacos , Acetilcolina/metabolismo , Amiloide/metabolismo , Amiloide/toxicidade , Animais , Antiulcerosos/metabolismo , Antiulcerosos/toxicidade , Califórnio/metabolismo , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Masculino , Espectrometria de Massas , Mercúrio/toxicidade , RatosRESUMO
Due to helium production following alpha decay, it is necessary to demonstrate the structural integrity of new 252Cf sources at elevated temperatures for special form certification by the U.S. Department of Transportation. Effects of temperature, capsule composition, and capsule dimensions are examined and reduced to a simple mathematical model. This highly conservative model assumes that all gas products leaving the radioactive source wire are retained by the capsule, and upon elevation to a temperature of 800 degrees C the capsule exhibits negligible expansion or change in internal volume and no increase in gas-phase components due to vaporization of spontaneous fission products. The calculated maximum loadings for the ORNL-made Applicator Tube and three proposed high dose rate 252Cf sources encapsulated in Pt/Ir-10% (VariSource, microSelectron classic, and a novel design) were 10.8, 0.508, 0.708, and 2.12 mg 252Cf, respectively.
Assuntos
Braquiterapia/instrumentação , Braquiterapia/métodos , Califórnio/uso terapêutico , Califórnio/metabolismo , Hélio , Modelos Teóricos , Radioisótopos/metabolismo , Radioisótopos/uso terapêutico , Temperatura , Fatores de TempoAssuntos
Plutônio/metabolismo , Elementos da Série Actinoide , Amerício/metabolismo , Animais , Animais Recém-Nascidos/metabolismo , Berkélio/metabolismo , Osso e Ossos/metabolismo , Califórnio/metabolismo , Cúrio/metabolismo , Einstêinio/metabolismo , Embrião de Mamíferos/metabolismo , Feminino , Feto/metabolismo , Humanos , Absorção Intestinal , Fígado/metabolismo , Netúnio/metabolismo , Nitratos/metabolismo , Oxirredução , Óxidos/metabolismo , Gravidez , Respiração , Absorção Cutânea , Tório/metabolismo , Distribuição TecidualAssuntos
Amerício/metabolismo , Califórnio/metabolismo , Fígado/metabolismo , Ácido Pentético/farmacologia , Amerício/farmacologia , Animais , Osso e Ossos/metabolismo , Califórnio/farmacologia , Cricetinae , Relação Dose-Resposta a Droga , Feminino , Meia-Vida , Injeções Intraperitoneais , Rim/metabolismo , Ácido Pentético/metabolismo , RatosAssuntos
Califórnio/metabolismo , Ácido Pentético/farmacologia , Animais , Carga Corporal (Radioterapia) , Califórnio/urina , Exposição Ambiental , Fezes/análise , Injeções Intraperitoneais , Rim/metabolismo , Fígado/metabolismo , Pulmão/metabolismo , Masculino , Ácido Pentético/administração & dosagem , Ácido Pentético/uso terapêutico , Poluentes Radioativos , Ratos , TraqueiaAssuntos
Califórnio/metabolismo , Animais , Carga Corporal (Radioterapia) , Neoplasias Ósseas/etiologia , Osso e Ossos/metabolismo , Cães , Feminino , Raios gama , Meia-Vida , Radioisótopos do Iodo/análise , Rim/metabolismo , Fígado/metabolismo , Masculino , Neoplasias Induzidas por Radiação , Fissão Nuclear , Sarcoma Experimental/etiologia , Glândula Tireoide/análise , Glândula Tireoide/metabolismoRESUMO
A method has been developed whereby the liver content of photon-emitting transuranium elements can be determined in living beagles by a combination of total-body and partial-body counting. Calibration of the system was accomplished through the photon counting of intact dogs and also of the parts of the same animals following autopsy. A determination of the calibration factors for 252Cf, 247Cf, 243Cm, 237Pu, and 241Am has been made. The special case of 252Cf was treated in which a significant fraction of the high energy fission gamma-ray spectrum penetrates the Pb shield employed in partial-body counting, and methods were developed which allow for this effect in the calculation of liver content. Some uniformity of response in the system was evident for all of the emitters which were considered. It is proposed that similar techniques could be applied in the determination of selected organ radioactivity in other species including man.
