Effects of Tityus serrulatus scorpion venom on thromboelastogram in rats.

Thromboelastometry was used to evaluate blood coagulation in anesthetized rats after intravenous administration of Tityus serrulatus scorpion venom (Tx). Tracheostomy followed by catheterization of the left jugular vein and right carotid artery were performed for Tx or Ringer's lactate solution injection and blood sample harvesting, respectively. Blood samples were obtained at the beginning of the experiments (baseline) and at two, five, 15, 30, and 60 min after intoxication. The following coagulation parameters were analyzed: CT (Clotting Time), CFT (Clotting Formation Time), Alpha Angle (α), MCF (Maximum Clot Firmness) and TPI (Thrombodynamic Potential Index). Toxin-induced hypercoagulability was demonstrated at the 15 and 60 min. We hypothesize Tx-induced hypercoagulability and enhanced clot formation could be explained by catecholamine release, systemic inflammatory response, and complement system activation, at least in the first hour after envenomation. Further studies are needed to determine the molecular mechanism of Tx-induced coagulopathy.

Avaliação da infestação e diversidade de Teredinidae (Mollusca - Bivalvia) ao longo da costa do estado do Rio de Janeiro, Brasil / Evaluation of the infestation and diversity of Teredinidae (Mollusca - Bivalvia) along the coast of Rio de Janeiro State, Brazil

In order to evaluate the diversity and infestation level of Teredinidae wood-boring molluscs, ten satations were chosen along the coast of Rio de Janeiro State. Using five pine-wood panels in each station, it was possible to distinguish five areas according to species dominance. Ilha Grande Bay is characterized by the dominance of Lyrodus floridanus (Bartsch, 1922); Sepetiba Bay, by Bankia fimbriatula Moll & Roch, 1931, Tijuca Lagoon by Teredo navalis Linnaeus, 1758; Guanabara Bay by Notoredo knoxi (Bartsch, 1917) and Araruama Lagoon by Teredo furcifera Martens, 1894. Specific composition and dominance of these species were due mainly to abiotic factors such as salinity whereas infestation level was associated not only to salinity but also to other factors such as the quantity and quality of fouling, the presence of larval dispersion focus and the wood supply in each area.