Bothrops atrox mice experimental envenoming treatment using light-emitting diode (led) as an adjunct therapy to conventional serum therapy.

The use of anti-venom is one of the main control measures for snakebite envenoming when applied immediately after the snakebite. Systemic effects of the envenoming are usually reversed; however, neutralization of local effects is hardly achieved. The need for adjuvant therapies associated with serum therapy can improve the treatment for local effects of envenoming, with greater effectiveness in preventing or delaying the progression of damage, reducing the clinical signs and symptoms of victims of snakebites. The purpose of the study was to evaluate the photobiomodulation therapy using LED and/or dexamethasone associated with conventional serum therapy for the treatment of local damage caused by Bothrops atrox envenomation in a murine model. For this, experimental envenoming was carried out in the gastrocnemius muscle of male Swiss mice weighing 18 to 22 g divided into 8 groups of animals, distributed in groups non-treat, treated with anti-bothropic serum, dexamethasone, and LED, or the associated treatments, by intramuscular inoculation of 50 µg of venom or sterile PBS (control). After 30 min, the proposed treatments were administered alone or in combination. After 3 h, blood and muscle samples were collected for myotoxicity, cytotoxicity, histological analysis, and IL-1ß assays. The evaluation of the treatment alone showed that serum therapy is not effective for the treatment of local damage and photobiomodulation demonstrated to be an effective therapy to reduce leukocyte infiltration, hemorrhage, and myotoxicity in experimental envenoming; dexamethasone proved to be a good resource for the treatment of the inflammatory process reducing the leukocyte infiltration. The association of serum therapy, LED, and dexamethasone was the best treatment to reduce the local effects caused by Bothrops atrox venom. All in all, the association of photobiomodulation therapy using LED with conventional serum therapy and the anti-inflammatory drug is the best treatment for reducing the undesirable local effects caused by snakebite accidents involving B. atrox species.

Increase in the risk of snakebites incidence due to changes in humidity levels: A time series study in four municipalities of the state of Rondônia.

INTRODUCTION: Snakebites represent a serious global public health problem, especially in tropical countries. In Brazil, the incidence of snakebites ranges from 19 to 22 thousand cases per 100000 persons annually. The state of Rondônia, in particular, has had an increasing incidence of snakebites. METHODS: A retrospective cross-sectional study on snakebites was conducted from January 2007 to December 2018. Brazil's Information System for Notifiable Diseases was queried for all snakebites reported in Porto Velho, Ariquemes, Cacoal, and Vilhena. Data on land surface temperatures during the day and night, precipitation, and humidity were obtained using the Google Earth Engine. A Bayesian time series model was constructed to describe the pattern of snakebites and their relationship with climate data. RESULTS: In total, 6326 snakebites were reported in Rondônia. Accidents were commonly caused by Bothrops sp. (n=2171, 81.80%). Snakebites most frequently occurred in rural areas (n=2271, 85.5%). Men, with a median age of 34 years (n=2101, 79.1%), were the most frequent bitten. Moderate clinical manifestation was the most common outcome of an accident (n=1101, 41.50%). There were clear seasonal patterns with respect to rainfall, humidity, and temperature. Rainfall and land surface temperature during the day or night did not increase the risk of snakebites in any city; however, changes in humidity increased the risk of snakebites in all cities. CONCLUSION: This study identified the population exposed to snakes and the influence of anthropic and climatic factors on the incidence of snakebites. According to climate data, changes in humidity increased the risk of snakebites.

Lectin isolated from Bothrops jararacussu venom induces IL-10 release by TCD4+ cells and TNF-α release by monocytes and natural killer cells.

BjcuL is a C-type lectin isolated from Bothrops jararacussu snake venom with specificity for binding ß-d-galactose units. BjcuL is not toxic to human peripheral blood mononuclear cells (PBMCs), but it inhibits PBMC proliferation and stimulates these cells to produce superoxide anions and hydrogen peroxide primarily via lymphocyte stimulation; it does not stimulate the production of nitric oxide and PGE2 . The purpose of this study was to investigate the effect of BjcuL on PBMC activation with a focus on cytokine release modulating PBMC proliferation. The results showed for the first time that BjcuL coupled to FITC interacted with monocytes, B cells, natural killer (NK) cells, and with subpopulations of T cells. These cell-cell interactions can lead to cell activation and inflammatory cytokines release, such as IL-6 and TNF-α, as well as the anti-inflammatory cytokine IL-10. In addition, TNF-α release was attributed to NK cells and monocytes, whereas IL-10 was attributed to TCD4+ and Treg cells when stimulated by BjcuL. The temporal cytokines profile produced by cells when stimulated with this lectin allows us to assert that BjcuL has immunomodulatory activity in this context.

Increase in the risk of snakebites incidence due to changes in humidity levels: A time series study in four municipalities of the state of Rondônia

Abstract INTRODUCTION: Snakebites represent a serious global public health problem, especially in tropical countries. In Brazil, the incidence of snakebites ranges from 19 to 22 thousand cases per 100000 persons annually. The state of Rondônia, in particular, has had an increasing incidence of snakebites. METHODS: A retrospective cross-sectional study on snakebites was conducted from January 2007 to December 2018. Brazil's Information System for Notifiable Diseases was queried for all snakebites reported in Porto Velho, Ariquemes, Cacoal, and Vilhena. Data on land surface temperatures during the day and night, precipitation, and humidity were obtained using the Google Earth Engine. A Bayesian time series model was constructed to describe the pattern of snakebites and their relationship with climate data. RESULTS: In total, 6326 snakebites were reported in Rondônia. Accidents were commonly caused by Bothrops sp. (n=2171, 81.80%). Snakebites most frequently occurred in rural areas (n=2271, 85.5%). Men, with a median age of 34 years (n=2101, 79.1%), were the most frequent bitten. Moderate clinical manifestation was the most common outcome of an accident (n=1101, 41.50%). There were clear seasonal patterns with respect to rainfall, humidity, and temperature. Rainfall and land surface temperature during the day or night did not increase the risk of snakebites in any city; however, changes in humidity increased the risk of snakebites in all cities. CONCLUSION: This study identified the population exposed to snakes and the influence of anthropic and climatic factors on the incidence of snakebites. According to climate data, changes in humidity increased the risk of snakebites.