Barietin, a snake venom vascular endothelial growth factor from puff adder Bitis arietans venom, increases the heart rate with minor effect on blood pressure in rats

Posted by
  Barietin, a snake venom vascular endothelial growth factor from puff adder Bitis arietans venom, increases the heart rate with minor effect on blood pressure in rats ABSTRACT Snake venom vascular endothelial growth factors (svVEGFs) are homodimeric proteins comprising two equal subunits bound by two intermolecular disulfide bonds. The main biological effects of svVEGFs are local vasodilatation, increasing of vascular permeability, and hypotension. Barietin, a svVEGF purified from the venom of puff adder Bitis arietans , differs from other representatives of this toxin family by its shortened C-terminal amino acid sequence. No data about barietin effects on hemodynamics are available. Studying those in rats we found that barietin at a dose of 1 mg/kg significantly increased heart rate, exerting only a minor influence on blood pressure. In this respect, it differs from other svVEGFs having a significant effect on blood pressure. We aimed to find the barietin active fragment which m...

Ecological and social contexts of scorpion stings in Manaus, the largest metropolis of the Brazilian Amazon

Posted by

 


Ecological and social contexts of scorpion stings in Manaus, the largest metropolis of the Brazilian Amazon

Abstract

Scorpion stings remain a significant public health problem in tropical regions, particularly in Brazil, where an estimatied 117,185 cases are reported annually, reflecting a persistent and growing burden on the healthcare system. Globally, more than two million cases occur each year, especially in areas undergoing environmental disturbances such as deforestation and unplanned urbanization. This study investigates the ecological and social contexts of scorpion stings in Manaus, the largest metropolis of the Brazilian Amazon. This qualitative study was conducted at the Dr. Heitor Vieira Dourado Tropical Medicine Foundation (FMT-HVD), a reference center for scorpion stings, between January 2020 and March 2025. Data were collected through clinical questionnaires, in-depth interviews, and household field observations. Thematic analysis was performed using Atlas.ti. Thirty participants from different age groups were included. Most cases were clinically mild. Five themes emerged from the qualitative analysis that address perceptions and reactions to the sting, environmental risk factors, post-accident behaviors, emotional impacts, and patient care pathways. Participants reported overlap between domestic spaces and forest fragments, limited knowledge about prevention, emotional distress, and barriers to accessing care, including late referrals and transportation difficulties. Scorpion stings in the Amazon are shaped by environmental, social, and structural factors. Integrated strategies involving environmental management, health education, urban planning, and improved healthcare access are essential to reduce their burden.
Benzaken, Z. S., Cristino, J. S., Benzaken, H., Sachett, J., Da Silva Carvalho, E., Da Silva Mendes, Y., Da Silva Pereira, H., Silva-Neto, A., Wen, F. H., Guerra, M. D. G. V. B., & Monteiro, W. (2026). Ecological and social contexts of scorpion stings in Manaus, the largest metropolis of the Brazilian Amazon. Toxicon, 278, 109122. https://doi.org/10.1016/j.toxicon.2026.109122