Monitorização citogenética de dentistas brasileiros ocupacionalmente expostos a baixos níveis de radiação X

A exposição à radiação ionizante pode causar aberrações cromossômicas (AC) em células somáticas ou germinativas dos indivíduos expostos, podendo levar a manifestações de doenças como os cânceres. Este trabalho teve como objetivo avaliar a freqüência de AC em linfócitos obtidos através de cultura temporária do sangue periférico de dentistas de Londrina (Paraná - Brasil), com mais de dez anos de trabalho com raios X. Os resultados obtidos do grupo experimental foram comparados com um grupo controle negativo pareado, que nunca se expôs ocupacionalmente aos raios X. Todos os indivíduos, dentistas e controles, responderam a um questionário pessoal, a partir do qual foi obtido um perfil de cada grupo. Após as culturas, as lâminas foram confeccionadas, coradas com solução de Giemsa e foram analisadas de 100 a 200 células metafásicas por indivíduo, anotando-se as freqüências e tipos de AC encontrados. Não foi necessária a realização de testes estatísticos para avaliação desses parâmetros. A análise dos índices mitóticos (IM) não indicou diferenças significantes (p < 0,05) entre os indivíduos dos grupos expostos e controle. Os fatores de variação analisados não influenciaram os resultados obtidos para o IM e freqüência de AC.Exposure to X-rays (ionizing radiation) may cause chromosomal aberrations (CA) in somatic or germinative cells in exposed individuals, and may lead to manifestations of diseases such as cancer. This study was carried out to assess the CA frequency in lymphocytes obtained by means of temporary culture of peripheral blood from dentists in Londrina, Paraná, Brazil, who have worked for more than ten years with X-rays. The results obtained from the experimental group were compared with a matched negative control group, which had never been exposed to X-rays. All individuals, dentists and controls, answered a personal questionnaire, from which a profile of each group was obtained. Slides, prepared after the cultures, were stained with Giemsa, and 100 to 200 metaphase cells were analyzed per individual. CA frequencies and types were registered and statistical tests were not necessary to evaluate the obtained data. The analysis of mitotic index (MI) did not indicate significant differences (p < 0.05) between the group of individuals exposed to X-rays and the control group. The analyzed confounding factors did not influence the results of MI and CA frequencies

A new species of Microcancilla from the southwestern Atlantic and notes on Microcancilla brasiliensis comb. nov. (Gastropoda, Cancellariidae)

Microcancilla phoenix sp. nov., collected from the Southeast and South coast of Brazil represents the southernmost record of the genus in the Atlantic Ocean. The new species differs from the other congeners of the Atlantic mainly by the presence of microscopic pustules covering the whole shell and by dimensions of the protoconch. “Axelella brasiliensis” Verhecken, 1991, known from the Northeast to South coast of Brazil, is transferred to Microcancilla based on a similar sculpture of microscopic pustules on the protoconch and on other features of the teleoconch discussed in the present study

The genus Brookula Iredale, 1912 (Gastropoda, Trochidae) from Brazil: description of a new species, with notes on other South American species

Absalão, Ricardo S., Miyaji, Cintia, Pimenta, Alexandre D. (2001): The genus Brookula Iredale, 1912 (Gastropoda, Trochidae) from Brazil: description of a new species, with notes on other South American species. Zoosystema 23 (4): 675-687, DOI: http://doi.org/10.5281/zenodo.539390