Mutation research
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The pathologic mechanisms underlying the gestational trophoblastic diseases are largely unexplored, but are thought to involve oxidative damage to the maternal vasculature and also to the placenta. In this study we have assessed the plasma levels of total antioxidant response (TAR) and the levels of endogenous DNA damage--determined by the comet assay--in peripheral blood lymphocytes from 13 women with complete hydatidiform mole (CHM) and compared these with those of 12 healthy pregnant controls and 10 healthy non-pregnant controls. Significantly lower mean levels of plasma TAR were found in patients with CHM compared with healthy pregnant controls (1.08+/-0.29 versus 1.17+/-0.14 mmol Trolox Eq/L, p<0.05) and with healthy non-pregnant controls (1.08+/-0.29 versus 1.38+/-0.12 mmol Trolox Eq/L, p<0.05). ⋯ These results reveal a relationship between the extracellular and intracellular (as reflected by damage to the DNA) levels of oxidation. Our observations suggest that there is a link between the increased levels of oxidative stress and the increase in endogenous DNA damage seen in patients with CHM, as compared with those seen in normal pregnancy. However, the nature of this link, and whether it is direct or indirect, remains to be explored.
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It has been postulated that exposure to nitrous oxide and halogenated anaesthetics is associated with various adverse health effects such as neurological and reproductive abnormalities or impairment of hepatic functions. In spite of the quite well known genotoxic effects of exposure to nitrous oxide in vivo, the mechanisms of these effects are still not clear. The aim of this study was to assess the frequency of micronuclei and to identify the type of chromosomal damage (clastogenic or aneugenic) in peripheral blood lymphocytes of operating-room nurses exposed to nitrous oxide. ⋯ The multiple regression analysis revealed a statistically significant relationship (p=0.0009) between MN frequency and exposure status, indicating that the level of exposure was the main factor affecting chromosomal damage. As assessed by FISH analysis, the overall frequencies of centromere-positive MN in the control and exposed groups were 43 and 49%, respectively. The increase observed in the exposed group may suggest a slight, statistically insignificant pro-aneugenic effect of exposure to nitrous oxide.
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Cigarette smoking is the predominant risk factor for bladder cancer (BC). Major carcinogens present in tobacco smoke include a number of aromatic and heterocyclic amines. Two distinct N-acetyl transferase (NAT) enzymes, NAT1 and NAT2, play important roles in the bio-activation and detoxification of these carcinogens. ⋯ Using never smokers with NAT2 rapid acetylator genotypes as a reference group, heavy smokers with NAT2 slow acetylator genotypes showed an over six-fold increase in BC risk. In a multiplicative interaction model, the interaction term was statistically significant (P=0.02). Our data suggest that having a NAT2 slow acetylator genotype is a significant risk factor for BC, particularly in smokers and older individuals.
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The examination of a single scientific manuscript seldom alerts scientists, reviewers, editors, and scientific administrators to the fabrication and falsification of data and information. This review shows that most documented cases of scientific fraud involve falsification (altering truthful information) and fabrication (inventing information where none previously existed). Plagiarism is much less frequent. ⋯ This review documents and compares many of the better-known cases of scientific fraud. Fraudulent behavior has served as the impetus for the scientific community to develop publication procedures and guidelines that help to guard against not only fraudulent behavior but also against other types of unethical or undesirable behaviors. A companion paper reviews the non-fraudulent issues associated with scientific publication.
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Review Historical Article
Scientific authorship. Part 2. History, recurring issues, practices, and guidelines.
One challenge for most scientists is avoiding and resolving issues that center around authorship and the publishing of scientific manuscripts. While trying to place the research in proper context, impart new knowledge, follow proper guidelines, and publish in the most appropriate journal, the scientist often must deal with multi-collaborator issues like authorship allocation, trust and dependence, and resolution of publication conflicts. Most guidelines regarding publications, commentaries, and editorials have evolved from the ranks of editors in an effort to diminish the issues that faced them as editors. ⋯ Needs that emerge from this review are (a) a need for more controlled studies on authorship issues, (b) an increased awareness and a buy-in to consensus views by non-editor groups, e.g., managers, authors, reviewers, and scientific societies, and (c) a need for editors to express a greater understanding of authors' dilemmas and to exhibit greater flexibility. Also needed are occasions (e.g., an international congress) when editors and others (managers, authors, etc.) can directly exchange views, develop consensus approaches and solutions, and seek agreement on how to resolve authorship issues. Open dialogue is healthy, and it is essential for scientific integrity to be protected so that younger scientists can confidently follow the lead of their predecessors.