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Amifostine (WR-2721, Ethyol®), a phosphorylated thiol, demonstrates the unique ability to protect normal but not tumour tissue from cytotoxic damage induced by radiation therapy and chemotherapy. This study tested the effect of amifostine's active metabolite, the free thiol, WR-1065, on the cytotoxicity of standard anticancer drugs against human A2780 ovarian and MCF7 breast cancer cell lines in vitro, using the well-characterised sulphorhodamine B assay. 50% inhibitory concentration (IC50) values were determined for each of 16 different anticancer drugs in the presence and absence of the highest nontoxic dose of WR-1065 from concentration-response curves constructed in triplicate and based on 18 replicate cell culture plates for each tested drug concentration. Pretreatment with WR-1065 had no statistically significant effect on the IC50 value of any of the 16 drugs tested against either the A2780 or MCF7 human tumour cells. These data expand upon previous reports showing that amifostine does not protect tumours from the cytotoxic effects of anticancer agents. The ability of amifostine to protect against dose-limiting toxicity to a variety of normal tissues without protection of tumour should enhance the efficacy ratio of a wide range of standard anticancer drugs.

Many experiments are being conducted to find compounds that offer radioprotection against radiation damage and that are also non-toxic. It is hopeful that in the future, research for this technology will benefit patients undergoing cancer treatment by reducing radiation damage to normal cells and therefore reducing short and long term side effects experienced from treatments. Hamster cells were irradiated at doses of 60 and 120 rad, with and without Sphingosine-1-Phosphate mixed in with their growth medium. Post irradiation, it was observed that the S1P molecule seemed to have a radioprotective effect by decreasing the amount of cell death compared to the amount of cell death that occurred with the absence of the molecule. The results of this experiment will sent to Dr. Jon Tilly at Massachusetts General Hospital. Dr. Tilly is currently researching S1P as a possible radioprotector. / Graduation date: 2003

Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 4 uppsatser.

Orientador: Pedro Duarte Novaes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-14T19:58:59Z (GMT). No. of bitstreams: 1 Ramos-Perez_FlaviaMariadeMoraes_M.pdf: 885830 bytes, checksum: fc6b33497f6ca471c917c9731d6f59af (MD5) Previous issue date: 2005 / Resumo: O objetivo neste trabalho foi avaliar o efeito radioprotetor da vitamina E na função das glândulas salivares por meio da medida do volume de saliva, bem como analisar a concentração de proteína total. Foram utilizados 90 ratos machos (Rattus norvegicus, Albinus, Wistar), os quais foram divididos aleatoriamente em cinco grupos experimentais: controle, que corresponde ao grupo em que os animais receberam óleo de oliva; leo/irradiado, grupo no qual os animais receberam óleo de oliva e foram irradiados com dose única de 15 Gy de radiação gama na região de cabeça e pescoço; irradiado, grupo no qual os animais foram irradiados com dose única de 15Gy de radiação gama; vitamina E corresponde ao grupo em que os animais receberam solução de acetato de alfa tocoferol (vitamina E) mas não foram irradiados e vitamina E/irradiado, no qual os animais receberam solução de acetato de alfa tocoferol (vitamina E) antes de serem irradiados com dose única de 15Gy. Os animais foram sacrificados no tempo de 4 horas, 8 horas e 30 dias após a irradiação. Não foram observadas diferenças significativas entre os grupos nos tempos de 4 e 8 horas. Aos 30 dias, o volume salivar dos animais do grupo óleo irradiado estava diminuído significativamente em relação ao grupo controle. Os animais do grupo irradiado apresentaram volume de saliva significativamente menor quando comparado com os grupos controle, vitamina E e vitamina E/irradiado, os quais apresentaram volumes de saliva similar. Na composição da saliva não houve diferenças significativas no conteúdo de proteína total entre os grupos estudados. Os constituintes medidos mostraram reduções significativas apenas 4 horas após a irradiação para todos os grupos examinados. Podemos concluir que a radiação não exerceu nenhum efeito no conteúdo de proteína total da saliva dos ratos irradiados e que a vitamina E protegeu a função salivar 30 dias após a irradiação, desta forma podemos considerá-la como um radioprotetor em potencial. / Abstract: The aim of this study was evaluate the radioprotective effect of vitamin E in salivary gland function by salivar volume measurements, as well as analize the total protein concentration. For this purpose 90 male rats (Rattus norvegicus, Albinus, Wistar) were used and randomly divided in 5 experimental groups: control (I), which animals received olive oil; irradiated olive oil (II), group that the animals received olive oil and were irradiated with a single exposure dose of 15 Gy of gamma rays to the head and neck region; irradiated (III), which animals were only irradiated with a single exposure dose of 15 Gy of gamma rays; vitamin E (IV), correspond to the group which animals received tocopherol acetate solution but were not irradiated; irradiated vitamin E (V), which animals received tocopherol acetate solution before irradiation with a single exposure dose of 15 Gy gamma rays. The animals were sacrificed 4, 8 hours and 30 days after the irradiation procedure. We did not observe differences between the groups at 4 and 8 hours. At 30 days, the salivar volume in the animals pertaining to the irradiated olive oil group was significantly reduced in relation to the control group. The irradiation group presented salivar volume significantly diminished when compared to the control (I), vitamin E (IV) and irradiated vitamin E (V), which presented salivar volumes similar. In the salivar composition we did not observe significant differences in the total protein content between the groups studied. The constituents measured showed significant reductions only 4 hours for all the groups examined. We conclude that the radiation did not exert any effect in the total protein content of saliva in the irradiated rats and vitamin E protected the salivary function 30 days after irradiation. Thus, we can consider vitamin E as a potential radioprotective substance. / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica

Orientador: Adriano Fregonesi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T20:23:11Z (GMT). No. of bitstreams: 1 Borges_ClaudioFerreira_D.pdf: 1990683 bytes, checksum: 1a75e1725e18e65f74c600f93224b4bb (MD5) Previous issue date: 2015 / Resumo: Objetivo: Foi realizada uma pesquisa de âmbito nacional com urologistas brasileiros a fim de estudar seu comportamento frente à exposição à radiação e ao uso de equipamentos de proteção e monitoramento. Material e Métodos: Um questionário com 13 perguntas foi enviado por e-mail para urologistas brasileiros; as questões abordavam temas como características demográficas, a exposição à radiação, bem como a utilização de dispositivos de proteção e dosímetros. As razões pelas quais esses dispositivos não foram utilizados também foram investigadas. Resultados: Um total de 332 questionários foi preenchido completamente e analisado; a idade média dos entrevistados foi de 43,3 ± 10,8 anos. Aventais de chumbo e protetores de tireoide são utilizados em cada procedimento por 84,4% e 53,89% dos entrevistados, respectivamente. Óculos de proteção nunca são utilizados por 72,12% dos entrevistados. Urologistas mais velhos são mais propensos a não usar proteção adequada. Dos urologistas que responderam, 76,42% nunca usam dosímetros. Conclusão: Este estudo mostra uma utilização insatisfatória dos dispositivos de proteção contra radiação e dosímetros, revelando uma baixa adesão ao ALARA (as low as reasonably achievable) entre urologistas brasileiros / Abstract: Purpose: We performed a nationwide survey of Brazilian urologists to study behaviors toward radiation exposure and the use of protective and monitoring equipment. Material and Methods: A 13-question e-mail questionnaire was sent to Brazilian urologists; the questions addressed demographic characteristics, radiation exposure, and the utilization of shielding devices and dosimeters. The reasons why these devices were not used were also investigated. Results: A total of 332 completed questionnaires were analyzed; the median age of the respondents was 43.3 ± 10.8 years. Lead aprons and thyroid protection are utilized in every procedure by 84.4% and 53.89% of respondents, respectively. Protective eyeglasses are never used by 72.12% of the respondents. Older urologists were more likely not to use adequate protection. Of the urologists who responded, 76.42% never use dosimeters. Conclusion: This study shows an unsatisfactory utilization of radiation-shielding devices and dosimeters, revealing a low compliance to the ALARA (as low as reasonably achievable) principle among Brazilian urologists / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências

No / The Raman spectrum of scytonin, a novel derivative of the parent scytonemin, is predicted from DFT calculations of the most stable, lowest energy, conformational structure. The diagnostic importance of this study relates to the spectral ability to discriminate between scytonemin and its derivatives alone or in admixture with geological matrices from identified characteristic Raman spectral signatures. The successful interpretation of biosignatures from a wide range of cyanobacterial extremophilic colonization in terrestrial and extraterrestrial scenarios is a fundamental requirement of the evaluation of robotic spectroscopic instrumentation in search for life missions. Scytonemin is produced exclusively by cyanobacterial colonies in environmentally stressed habitats and is widely recognized as a key target biomarker molecule in this enterprise. Here, the detailed theoretical analysis of the structure of scytonin enables a protocol to be established for the recognition of characteristic bands in its Raman spectrum and to accomplish the successful differentiation between scytonin and scytonemin as well as other scytonemin derivatives such as the dimethoxy and tetramethoxy compounds that have been isolated from cyanobacterial colonies but which have not yet been characterized spectroscopically. The results of this study will facilitate an extension of the database capability for miniaturized Raman spectrometers which will be carried on board search for life robotic missions to Mars, Europa, and Titan.