Genetic damage in the bivalve mollusk Corbicula fluminea induced by the water-soluble fraction of gasoline.

Although gasoline is an important contaminant of aquatic ecosystems, information concerning the potential effects of this petroleum derivative on the DNA of aquatic biota is lacking. The present study aimed to evaluate the genotoxic and mutagenic effects of acute exposures (6, 24, and 96h) to gasoline water-soluble fraction (GWSF), diluted to 5%, on the Asian clam Corbicula fluminea. The comet assay and the micronucleus (MN) test were performed on hemocytes and gill cells of C. fluminea. For the three different times tested, the comet assay indicated DNA damage in hemocytes and gill cells of C. fluminea exposed to GWSF. The MN test detected significant damage in the genetic material of the hemocytes only after 96h of exposure to GWSF. The recovery capacity of organisms previously exposed for 6h to GWSF was also evaluated with the comet assay. The results revealed a great capacity of this species to repair DNA damage; following 6h of recovery, the comet score returned to that of the control groups. Overall, our findings indicate that GWSF has genotoxic and mutagenic effects on C. fluminea. In addition, the present results confirm the sensitivity of C. fluminea to damage caused by exposure to environmental contaminants, and, therefore, its suitability for use in environmental monitoring studies.

Epidemiological and ethical aspects of multiplex autoantibody testing.

Arrays are one of the technologies able to detect autoantibodies by measuring simultaneously many thousands of markers from a unique biological sample. The main purpose of a diagnostic test is making an early and accurate diagnosis. From a statistical point of view, multiple testing increases the probability of false positive and false negative results. Some correction methods are available to account for this problem for instance family-wise error rate or false discovery rate. From an ethical point of view, the decision to accept or decline a test not requested has to be made autonomously. Some people may seek clarification about tests and implications of their choices. A scarcity of proven measures to reduce mortality has to be considered too. Reasons may also include avoidance of psychological harm or anxiety. Moreover, protection of confidentiality and privacy has to be respected. In conclusion, the fact that testing is optional and that surveillance advice can be offered on the basis of risk alone without a test should be discussed in the consultation. The implication of a positive test result should be discussed to make a decision about the degree to which early treatment of the condition is better than late (or no) treatment.