Danos causados pelas radiações ionizantes sobre órgãos e sistemas vitais de fetos e crianças pequenas / Damage caused by ionizing radiation on organs and vital systems of fetuses and young children

Entrevista feita por jornalistas irlandeses, por ocasião da conferência de imprensa de Ady Roche (Chernobyl Children's Project (http://www.chernobylinternational.com), Minsk, abril de 2000.Tradução de Paulo Neves e revisão de Emico Okuno e Joaquim Francisco de Carvalho. O original em francês encontra-se à disposição do leitor para eventual consulta.

Alteraçöes cromossômicas causadas pela radiaçäo dos monitores de vídeo de computadores / Chromosome abnormalities caused by computer video display monitors' radiation

OBJETIVO: Em decorrência dos questionamentos sobre o efeito deletério das radiaçöes emitidas pelo campo eletromagnético (CEM) dos tipos ELF (extremely low frequency) e VLF (very low frequency) transmitidas pelos monitores de vídeo dos computadores (CRT), foi avaliada a freqüência de anomalias cromossômicas estruturais e a cinética do ciclo celular em indivíduos expostos por seu trabalho à radiaçäo dos CRT. MÉTODOS: A pesquisa de aberraçöes cromossômicas foi realizada em 2.000 metáfases de primeira divisäo celular obtidas de culturas de 48h de linfócitos de sangue venoso periférico de dez indivíduos expostos ao CRT (grupo E) e de dez controles (grupo C). A cinética do ciclo celular foi pesquisada pelos índices mitótico (IM) e de proliferaçäo celular (IPC). RESULTADOS: A análise estatística evidenciou freqüências significativamente maiores de metáfases com anomalias cromossômicas (E=5,9por cento; C=3,7por cento) e anomalias/célula (E=0,066ñ0,026; C=0,040ñ0,026) nos indivíduos expostos aos CRTs. As alteraçöes citogenéticas mais comuns foram as quebras cromatídicas, com freqüência de 0,034ñ0,016 no grupo E e de 0,016ñ0,015 no grupo C. As freqüências de IM e IPC näo apresentaram diferenças significantes entre os grupos avaliados. CONCLUSOES: Os resultados sugerem um efeito genotóxico do CEM emitido pelos CRTs devido à freqüência mais elevada de quebras cromatídicas, enfatizando a necessidade de haver um número maior de estudos com diferentes técnicas que vise a investigar a açäo do CEM sobre o material genético

International Genetic Epidemiology Society: commentary on Darkness in El Dorado by Patrick Tierney.

The International Genetic Epidemiology Society (IGES) has examined the charges against James V. Neel and his colleagues contained in the recently published book by Patrick Tierney entitled Darkness in El Dorado: How Scientists and Journalists Devastated the Amazon (W.W. Norton, 2000). The book implicates Neel in causing or promoting an epidemic of measles among the Yanomamö Indians of Venezuela in 1968 leading to "hundreds if not thousands" of deaths by using a "dinosaur" vaccine (Edmonston B) as a deliberate "experiment" to test his "eugenic" theories. Tierney also attempts to link this research, funded by the Atomic Energy Commission (AEC), with a broader tapestry of human radiation experiments. To investigate these serious charges, the IGES undertook a thorough examination of most source documents referenced in Tierney's book, Neel's field logs, notes, first-hand reports, contemporary writings, film sound tracks, etc., and conducted interviews with many relevant persons. The IGES finds that these allegations are false. Neel was not a eugenicist and was in fact highly critical of both the scientific basis of eugenics and its coercive social policies. In this regard, Tierney has grossly misrepresented Neel's views on a wide range of social implications of modern civilization for the long-term health of the gene pool. Far from causing an epidemic of measles, Neel did his utmost to protect the Yanomamö from the ravages of the impending epidemic by a vaccination program using a vaccine that was widely used at the time and administered in an appropriate manner. There was nothing experimental about the vaccination program, which in fact severely hindered the primary scientific objectives of the expedition. Although the research was funded in large part by the AEC, there was no element of radiation research and the work had no connection with the ethical abuses that have been reported from AEC-sponsored radiation research, such as studies of heavy isotopes. Neel's seminal contributions to a broad range of topics in human genetics have been extensively chronicled elsewhere. His research on the Yanomamö in particular has provided unique insights into the evolutionary biology of our species, the role of sociocultural practices, such as kinship relationships and selective pressures in shaping the genetic diversity of primitive population isolates, as well as the general picture of health in such populations. The IGES decries the damage done to the reputation of one of its founders and its first President and the misperception this book may have caused about the conduct of research in genetic epidemiology. Ethical issues about scientific research in primitive populations deserve serious and wide discussion, but the IGES condemns the gross misrepresentation of the facts and demonization of the principal characters in this book.

Situación y perspectivas de desarrollo de la genetica humana en el Ecuador / Situation and perspective of development of the human genetics in Ecuador

Contiene los res£menes de las exposiciones y documentos del Seminario sobre genética humana sin precedentes realizado en el Ecuador en 1997. Presenta estudios exhaustivos y completos sobre la genética médica y sus fundamentos, as¡ como los principales factores hereditarios que interviene en las malformaci¢n o disfunsiones humanas...

Genetic manipulation of Aspergillus niger for increased synthesis of pectinolytic enzymes

Um grupo de 35 mutantes morfológicos com potencial para síntese de enzimas pectinolíticas foi obtido de conídios de A. niger, empregando a técnica convencional de mutaçäo induzida por EMS seguida por irradiaçäo com UV. A linhagem mutante selecionada na primeira etapa (descrita como A. niger 5T25A) foi usada para a segunda etapa de induçäo de mutaçäo. Todas as linhagens selecionadas foram testadas para a síntese de enzimas pectinolíticas por fermentaçäo em estado sólido. Após 72h de fermentaçäo o extrato enzimático obtido pelo mutante A.niger 3T5B8 foi o que apresentou maior atividade enzimática. A atividade, medida por grupos redutores liberados e por reduçäo de viscosidade. Os valores obtidos para estes parâmetros foram, respectivamente, 56 por cento e 282 por cento maiores que os registrados para A.niger selvagem e 31 por cento e 147 por cento maiores que obtidos com o mutante A.niger 5T25A. O A.niger 3T5B8 mostrou uma acentuada reduçäo na sua capacidade de esporulaçäo e cresceu em meios com baixas atividades de água (aw) (meio básico, aw=0,96 e meio de fermentaçäo, aw=0,92), favorecendo o processo de fermentaçäo em estado sólido e formaçäo de colônias ausentes de setores em meios de cultura completo e básico

Efeitos genéticos das radiações no homem / Genetic effects of radiation on man

Um livro que expõe, analisa e discute problemas gerais sobre os riscos das radiações ionizantes e os métodos para a sua estimativa. Aqui se encontram também informações sobre os perigos da energia nuclear e os efeitos genéticos (mortalidade precoce e anomalias) e somáticos (câncer) mesmo de doses consideradas baixas

Reactions to ionizing radiation

This review deals with essential physical and biologic aspects of ionizing radiation as related to dermatology. The discussion of major physical factors and basic biophysics includes the production of x rays, dose definitions and recent changes in terminology, various factors affecting dose and tissue damage and current radiotherapy methods. The biologic effects and potential risks of ionizing radiation are reviewed in detail, particularly the major nonstochastic and stochastic somatic effects, such as radiation-induced skin cancer, thyroid carcinoma, breast cancer, and other radiogenic neoplasms. Current methods of risk assessment, radiation carcinogenesis, the efficacy of radiation protection technics, and potential genetic effects are critically evaluated.

[Human genetics studies in areas of high natural radiation. VII. Genetic load]. / Estudos de genética humana em áreas de alta radiacão natural. VII. Carga genetica

Two methods to estimate the inbreeding load (Morton, Crow and Muller17 1956; Freire-Maia and Freire-Maia6 1965) are reviewed. Both are employed in the analysis of our data. Besides the total population, a sample constituted of individuals with no alien ancestral is also analysed. No clean effect of natural radioactivity, as measured by genetic load models, has been found (this is especially valid for abortions, pre-natal mortality, anomalies, and abnormalities in general). The results on stillbirths and post-natal and total mortalities are discussed, and it is concluded that most probably the differences found are due to uncontrolled concomitant variables (if not to chance alone). Further analysis are under way.

Radioresistance in natural populations of Drosophila nebulosa from a Brazilian area of high background radiation.

D. nebulosa, collected in two woods of a high background radiation area (both in Iron Hills, State of Minas Gerais, Brazil), were compared to and found to be more resistant than flies collected as controls in two other woods of an adjacent area. This was the second time that average differences in radioresistance between natural populations were established. Previous experiments were carried out with D. willistoni, in the same area and in comparable fashion. In spite of their higher radiation resistance the flies from the radiation area carried a higher expressed load than the controls. The following tests were performed to estimate the differences: (a) survival, after whole body exposure to 90 000 R of 60Co-gamma-rays on 120 strains set up from single inseminated females and (b) reproductive performance, in 240 duplicate croses, measured in terms of the difference between irradiated series (males received 3000 R of 60Co-gamma-rays) and their unirradiated counterparts. The data are based on an offspring of 293784 individuals. Futhermore, two diallel crosses between sensitive and resistant strains have shown that the differences probably are due mainly to additive genes.