Coleopterofauna found on fresh and frozen rabbit carcasses in Curitiba, Paraná, Brazil.

Many arthropod species are associated with carrion and some of them can be used as forensic indicators in murder investigations to estimate the time of death. Different physical conditions of cadavers may influence the fauna and the importance of freezing and thawing is unknown. The present paper sought to survey the Coleoptera species encountered in frozen and fresh rabbit carcasses, at a forest in Curitiba, Brazil. Four rabbit carcasses, two of them fresh and the other frozen were used. The coleopterofauna was sampled daily, and analyzed using non-parametric tests. A total of 666 beetles were sampled, belonging to 28 species in 10 families. Most of the beetles captured were larvae of Oxelytrum spp. (433) which are known to be necrophagous. The two frozen carcasses accounted for most of the beetles (338 and 180) in comparison with the two fresh carcasses (103 and 45). The tests were based on the most abundant species. Oxelytrum spp. median differed significantly between carcasses (H = 12.47844; p = 0.0059). The two fresh carcasses differed significantly (U = 190.0; p = 0.00019), but there was no significant difference between the frozen carcasses (U = 336.0; p = 0.29755). The data indicate that the freezing process prevents certain species to colonize carcasses, in this case with the dominance of species of Oxelytrum. These data also indicate that careful attention is necessary before using frozen carcasses in forensic entomology studies.

Operclipygus hospes (Lewis) (Coleoptera, Histeridae): a beetle of potential forensic importance for buried bodies.

Operclipygus hospes (Lewis) is reported as a new record of Histeridae associated with buried bodies in the Neotropical region. It is also suggested that O. hospes has an important role in forensic entomology as a seasonal indicator. To assist in the recognition and the use of this species in forensic entomology, diagnosis and illustrations of the main characters of the genus and species are provided.

Effects of a vasorelaxing factor liberated by the rat isolated atria on rat aortic rings with and without endothelium.

In 1993, Illanes et al. described a vasoactive factor, the auricular vasorelaxing factor (AVF), by controlled distension of rat isolated atria. This factor produces vasodilation, antagonizing the vasoconstrictor action of phenylephrine. We now report assays by using isolated rat aortic rings and norepinephrine as a vasoconstrictor. Isolated thoraxic aortic rings were mechanically deprived of endothelium and subjected to the effects of increasing, cumulative concentrations of 6.6 x 10(-11) M to 6.6 x 10(-7) M norepinephrine. AVF significantly decreases the constrictor effect of norepinephrine assayed afterward, shifting the vasoconstrictor dose-response relation to the right. The effect was the same in rat aortic rings with or without endothelium. Subjecting aortic rings to control vehicle samples did not alter the dose-response curve to norepinephrine. We conclude that AVF antagonizes the norepinephrine vasoconstrictor effect in rat isolated aortic rings and that the mechanism of this vasorelaxing effect is independent of any contribution from the endothelial cells.