In Memoriam: Arthur (Art) Decae and His Contributions to Arachnology

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  Image Credit:  https://www.researchgate.net/profile/Arthur-Decae  In Memoriam: Arthur (Art) Decae and His Contributions to Arachnology The arachnological community has received the sad news of the passing of Arthur (Art) Decae of the Netherlands, a long-standing member of the International Society of Arachnology (ISA) and the European Society of Arachnology (ESA). Arthur was a respected authority on mygalomorph spiders, particularly those of Europe and the Mediterranean region. His research contributed significantly to the taxonomy, diversity, distribution, and natural history of these often poorly known spiders. In announcing his passing on behalf of the ISA, Jason Dunlop extended condolences to Arthur's family, friends, and colleagues. Marco Isaia, who remained in contact with Arthur during his final year, also shared a message that Arthur had specifically asked to be passed on to the arachnological community: “I would appreciate it if you tell our spider friends and ...

Venom from Loxosceles Spiders Collected in Southeastern and Northeastern Brazilian Regions Cause Hemotoxic Effects on Human Blood Components

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Venom from Loxosceles Spiders Collected in Southeastern and Northeastern Brazilian Regions Cause Hemotoxic Effects on Human Blood Components

Abstract

Spiders of the genus Loxosceles represent a public health problem in Brazil due to the severity of the cutaneous and systemic effects that may result from their bite. In the systemic form of loxoscelism, hemolytic anemia, thrombocytopenia, and disseminated intravascular coagulation can occur. Despite the seriousness of Loxosceles accidents, the venom of some species has not yet been properly characterized considering these hemotoxic effects, such as that of Loxosceles amazonica, Loxosceles aff. Variegata, and Loxosceles similis. To better understand their toxic potential, this study aimed to characterize the hematotoxic properties of these Loxosceles venoms. The crude venom was obtained from specimens of L. amazonica, L. aff. Variegata, and L. similis available from Funed’s arachnidary. In washed platelets, L. aff. variegata inhibited platelet aggregation induced by collagen and convulxin, whereas L. amazonica and L. similis venoms were able to induce platelet aggregation. In the in vitro hemolysis assays, all venoms experimentally induced direct hemolysis of human erythrocytes in a concentration-dependent manner, with different intensities. Furthermore, evidence suggest that the ABO and Rh systems may influence hemolytic activity. Finally, the studied Loxosceles venoms degraded fibrinogen, suggesting possible alterations in the coagulation cascade. Based in the here-presented preliminary study, in vivo assays in model animals are needed to verify the real toxic potential of these species’ venom, building up knowledge to elucidate the action of Loxosceles venoms in blood.

Mel, A., Luiza, A., Luize, P., Sanchez, E. F., Varela, L. S., & Paiva, A. L. (2024). Venom from Loxosceles Spiders Collected in Southeastern and Northeastern Brazilian Regions Cause Hemotoxic Effects on Human Blood Components. Toxins, 16(12), 532. https://doi.org/10.3390/toxins16120532