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1.
Toxicon ; 241: 107683, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38460604

RESUMO

OBJECTIVE: To establish a preclinical large-animal model of Deinagkistrodon acutus snakebite envenomation and evaluate its feasibility. METHODS: The venom of D. acutus (0 mg/kg, 1 mg/kg, 2 mg/kg, 5 mg/kg, or 10 mg/kg) was injected into the left biceps femoris of 11 male pigs. Then, the circumferences of the limbs were regularly measured, and changes in muscle injury biomarkers, blood parameters, coagulation function, vital organ function and injury biomarkers were regularly detected. At 24 h after venom injection, the animals were euthanized, and the pathological damage to the vital organs mentioned above was evaluated. RESULTS: The two pigs receiving 10 mg/kg and 5 mg/kg snake venom died at 8 h and 12 h after injection, respectively. The remaining pigs were equally divided into 0 mg/kg, 1 mg/kg, and 2 mg/kg snake venom groups, and all of them survived to 24 h after injection. Compared with the pigs receiving 0 mg/kg snake venom, the pigs receiving 1 mg/kg or 2 mg/kg snake venom exhibited significant abnormities, including limb swelling; increased muscle injury biomarker creatine kinase (CK) and coagulation function indicators prothrombin time and D-dimer; and decreased blood routine indicator platelet and coagulation function indicator fibrinogen. Moreover, significant abnormalities in myocardial and cerebral function and injury biomarkers in the heart, brain, liver, kidney and intestine were also observed. In particular, the abnormalities mentioned above were significantly obvious in those pigs receiving 2 mg/kg snake venom. Pathological evaluation revealed that the morphology of muscle, heart, brain, liver, kidney, and intestine in those pigs receiving 0 mg/kg snake venom was normal; however, pathological damage was observed in those pigs receiving 1 mg/kg and 2 mg/kg snake venom. Similarly, the pathological damage was more severe in those pigs receiving 2 mg/kg snake venom. CONCLUSION: The intramuscular injection of 2 mg/kg D. acutus venom seems to be an optimal dose for examining the preclinical efficacy of existing and novel therapeutics for treating D. acutus envenomation in pigs.


Assuntos
Crotalinae , Mordeduras de Serpentes , Serpentes Peçonhentas , Masculino , Animais , Suínos , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/veterinária , Mordeduras de Serpentes/patologia , Venenos de Serpentes/toxicidade , Biomarcadores
3.
Toxins (Basel) ; 15(2)2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36828472

RESUMO

Snakebite is a globally neglected tropical disease, with coagulation disturbances being the primary pathology of many deadly snake venoms. Age-related differences in human plasma have been abundantly reported, yet the effect that these differences pose regarding snakebite is largely unknown. We tested for differences in coagulotoxic effects (via clotting time) of multiple snake venoms upon healthy human adult (18+) and paediatric (median 3.3 years old) plasma in vivo and compared these effects to the time it takes the plasmas to clot without the addition of venom (the spontaneous clotting time). We tested venoms from 15 medically significant snake species (from 13 genera) from around the world with various mechanisms of coagulotoxic actions, across the three broad categories of procoagulant, pseudo-procoagulant, and anticoagulant, to identify any differences between the two plasmas in their relative pathophysiological vulnerability to snakebite. One procoagulant venom (Daboia russelii, Russell's Viper) produced significantly greater potency on paediatric plasma compared with adult plasma. In contrast, the two anticoagulant venoms (Pseudechis australis, Mulga Snake; and Bitis cornuta, Many-horned Adder) were significantly more potent on adult plasma. All other procoagulant venoms and all pseudo-procoagulant venoms displayed similar potency across both plasmas. Our preliminary results may inform future studies on the effect of snake venoms upon plasmas from different age demographics and hope to reduce the burden of snakebite upon society.


Assuntos
Daboia , Mordeduras de Serpentes , Animais , Humanos , Adulto , Criança , Pré-Escolar , Mordeduras de Serpentes/patologia , Antivenenos/farmacologia , Coagulação Sanguínea , Venenos de Serpentes/farmacologia , Anticoagulantes/farmacologia , Venenos de Víboras/farmacologia
4.
PLoS Negl Trop Dis ; 16(12): e0011013, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36548435

RESUMO

BACKGROUND: Bites by the hump-nosed pit vipers (HNPV) of the genus Hypnale are the commonest type of venomous snakebites in Sri Lanka. Their bites frequently cause local effects while rarely causing systemic envenoming, that may include acute kidney injury and coagulopathy. There are 3 species of genus Hypnale including H. hypnale, H. zara and H. nepa from which latter two are endemic to Sri Lanka. Virtually all studies on HNPV bites in Sri Lanka are focused on adults except two studies in paediatric group. The aims of this study were to describe the epidemiology and clinical manifestations of HNPV bites in a group of children admitted to a tertiary care hospital in Sri Lanka. METHODOLOGY/PRINCIPAL FINDINGS: This was a prospective observational study carried out in Teaching Hospital Ratnapura, Sri Lanka over 27 months commencing from May 2020 including all children aged up to 14 years with the history of HNPV bites. There were 40 (56%) HNPV bites, of them 28 (70%) were males. The age was 84 months (50.2-120 months). Majority (n = 21;52.5%) were bitten during day-time (06:00-17:59) in home gardens (n = 20; 50%) on lower limbs (n = 24;60%). Most children (n = 30;75%) were admitted to the medical facility < 4 hours after the snakebite [90 min (40-210 min)] and the hospital stay was 4 days (3-5 days). Local envenoming was observed in 38 patients (95%) and systemic effects developed in 4 patients (10%) as mild coagulopathy. Local effects include local pain (n = 30; 94%), swelling (n = 38;95%), blistering (n = 11;27.5%), necrosis at the site of bite (n = 11; 27.5%), regional lymph node enlargement (n = 8;20%) and local bleeding (n = 4;10%). For the local effects, surgical interventions were needed in 10 children (25%) and 3 (7.5%) of them developed acute compartment syndrome leading to fasciotomy. Leucocytosis (n = 28;78%) and eosinophilia (n = 9;27%) were the prominent laboratory findings. All got recovered except in patients with fasciotomy who got permanent scar. CONCLUSIONS/SIGNIFICANCE: Hump-nosed pit viper bites mostly cause local effects and rarely systemic envenoming in children. Compartment syndrome is common in children following their bites.


Assuntos
Transtornos da Coagulação Sanguínea , Crotalinae , Mordeduras de Serpentes , Adulto , Masculino , Animais , Humanos , Criança , Feminino , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/epidemiologia , Mordeduras de Serpentes/patologia , Transtornos da Coagulação Sanguínea/etiologia , Hemorragia , Sri Lanka/epidemiologia
5.
Toxicon ; 219: 106924, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36126694

RESUMO

The Brazilian Amazon has high rates of snakebite envenomings (SBEs), with ∼90% caused by Bothrops atrox. Envenomings by this species can trigger local and systemic effects, such as acute kidney injury (AKI). Our aim was to identify predictors of AKI in Bothrops SBEs in patients from Manaus, Western Brazilian Amazon. A total of 127 patients were enrolled, with a predominance of men between 16 and 45 years old from rural areas. Of the 127 patients, 38.6% developed AKI, with 61.2% presenting stage I, 34.7% presenting stage II and 4.1% presenting stage III severity. The age groups 0-10 years and ≥60 years presented a significantly higher frequency of AKI compared to the 11-40 years group. Moderate/severe edema in the affeccted limb was significantly associated with lower risk of AKI [p = 0.01; OR = 0.11 (95%CI 0.02-0.53)]. Nausea [p = 0.01; OR = 54.44 (95%CI = 3.26-909.27)] and high blood urea levels [p = 0.01; OR = 5.38 (95%CI = 2.12-13.66)] were risk factors for AKI. There was a significant positive correlation between circulating venom levels and the highest creatinine serum values during the hospital stay (p = 0.03) and with the difference between the maximum creatinine levels and the creatinine levels on admission (p = 0.02). A positive correlation between serum venom concentrations and creatinine levels suggests a direct or indirect dose-dependent participation of the venom toxins in the pathogenesis of AKI.


Assuntos
Injúria Renal Aguda , Bothrops , Venenos de Crotalídeos , Mordeduras de Serpentes , Masculino , Animais , Humanos , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Feminino , Venenos de Crotalídeos/toxicidade , Creatinina , Mordeduras de Serpentes/patologia , Injúria Renal Aguda/induzido quimicamente , Ureia , Brasil/epidemiologia , Antivenenos
6.
Toxicon ; 218: 8-12, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36041514

RESUMO

Snakebite is a life-threatening and often-neglected public health hazard with high chronic disability and mortality, mainly faced by rural communities in the tropics/subtropics. Stroke and neuromuscular paralysis are the most severe neurological complications. However, cerebral venous sinus thrombosis has rarely been reported among cerebrovascular complications. We report a previously healthy middle-aged Indian woman who developed cerebral venous sinus thrombosis preceded by features of disseminated bleeding diathesis following Russell's viper bite. The cerebral venous sinus thrombosis was diagnosed by magnetic resonance imaging. The patient responded well to treatment with antivenom and subcutaneous enoxaparin and had no demonstrable neurological deficits at three months of follow-up.


Assuntos
Daboia , Trombose dos Seios Intracranianos , Mordeduras de Serpentes , Animais , Antivenenos , Enoxaparina , Humanos , Trombose dos Seios Intracranianos/complicações , Trombose dos Seios Intracranianos/etiologia , Mordeduras de Serpentes/patologia , Venenos de Víboras/toxicidade
7.
Toxins (Basel) ; 14(6)2022 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-35737039

RESUMO

This study reported reproductive pathologies associated with Echis ocellatus venom in animal model. Twenty male Wistar rats with body weight between 180 and 220 g were selected randomly into two groups (n = 10). Rats in group 1 served as the control while rats in group 2 were envenomed with a single intraperitoneal injection of 0.055 mg/kg−1 (LD6.25) of E. ocellatus venom on the first day and a repeated dose on the twenty fifth day. Both control and envenomed rats were monitored for fifty consecutive days. The venom caused a significant (p < 0.05) reduction in sperm motility, count, and volume, with increased sperm anomalies in envenomed rats compared to the control. Likewise, serum concentrations of male reproductive hormones were significantly (p < 0.05) higher in envenomed rats. Increased levels of malondialdehyde were accompanied by a significant (p < 0.05) decrease in reduced glutathione and catalase activity in the epididymis and testis tissues of envenomed rats. The venom enhanced the release of epididymal and testicular tumor necrosis factor-alpha and interleukin1-beta compared to the control. Furthermore, severe pathological defects were noticed in tissues of the testis and epididymis of envenomed rats. This study demonstrated that E. ocellatus venom toxins can induce reproductive dysfunction in male victims of snake envenoming.


Assuntos
Mordeduras de Serpentes , Viperidae , Animais , Antivenenos , Citocinas , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Sêmen , Mordeduras de Serpentes/patologia , Venenos de Serpentes , Motilidade dos Espermatozoides , Espermatozoides/patologia , Testículo/patologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-34508870

RESUMO

Snakebite envenomation caused by the Western and Eastern Russell's Vipers (Daboia russelii and Daboia siamensis) may potentially induce capillary leak syndrome (CLS), while the use of antivenom in treating this has not been well examined. This study investigated the CLS-inducing toxicity of Russell's Viper venoms from various sources and examined the neutralization activity of regionally available antivenoms, using a newly devised mouse model. D. russelii venoms demonstrated a more consistent vascular leakage activity (76,000-86,000 CLS unit of vascular leak index, a function of the diameter and intensity of Evans Blue dye extravasation into dermis) than D. siamensis venoms (33,000-88,000 CLS unit). Both species venoms increased hematocrits markedly (53-67%), indicating hemoconcentration. Regional antivenoms (DsMAV-Thailand, DsMAV-Taiwan, VPAV-India) preincubated with the venoms effectively neutralized the CLS effect to different extents. When the antivenoms were administered intravenously post-envenomation (challenge-rescue model), the neutralization was less effective, implying that CLS has a rapid onset that preceded the neutralizing activity of antivenom, and/or the antivenom has limited biodistribution to the venom's inoculation site. In conclusion, Russell's Viper venoms of both species from various locales induced CLS in mice. Antivenoms generally had limited efficacy in neutralizing the CLS effect. Innovative treatment for venom-induced CLS is needed.


Assuntos
Antivenenos/farmacologia , Síndrome de Vazamento Capilar/tratamento farmacológico , Daboia , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Víboras/toxicidade , Animais , Vasos Sanguíneos/efeitos dos fármacos , Síndrome de Vazamento Capilar/induzido quimicamente , Síndrome de Vazamento Capilar/patologia , Feminino , Camundongos , Camundongos Endogâmicos ICR , Testes de Neutralização , Mordeduras de Serpentes/induzido quimicamente , Mordeduras de Serpentes/patologia
9.
J Comp Pathol ; 186: 1-6, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34340798

RESUMO

Black snakes (Pseudechis spp) are a genus of venomous Australian elapid snakes that can cause major clinical envenomation in companion animals, which may be fatal, even with appropriate antivenom treatment. Despite its clinical significance, there is little published information on the pathology of black snake envenomation. We report the gross and microscopic lesions associated with black snake envenomation in two dogs, one with a definitive immunological species identification of red-bellied black snake (RBBS; Pseudechis porphyriacus), the other with a black snake immunotype on a venom detection kit. Both dogs were located in a geographical area where the RBBS is found. The prominent gross findings in both cases included icterus, localized facial oedema in the region of the presumed bite wound, pigmenturia and multicavitary serosanguineous effusions. Histopathology of the confirmed RBBS case revealed acute renal tubular necrosis with haemosiderosis, marked splenic haemosiderosis and centrilobular to midzonal hepatocellular necrosis with severe cholestasis. Defining the spectrum of lesions of elapid snake envenomation improves understanding of the pathogenesis, which may lead to improved patient outcomes and post-mortem diagnosis.


Assuntos
Mordeduras de Serpentes , Animais , Antivenenos/uso terapêutico , Austrália , Cães , Venenos Elapídicos , Elapidae , Mordeduras de Serpentes/patologia , Mordeduras de Serpentes/veterinária
10.
Acta Trop ; 222: 106047, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34273312

RESUMO

The systemic effects generated by Porthidium lansbergii lansbergii envenoming, a species found in the northern region of Colombia, is poorly known. The present study aimed to analyze for the first time the mice's behavior, the histological alterations, and changes in biochemical markers levels resulting from the intraperitoneal injection of an LD50 of P. lansbergii lansbergii snake venom on mice. The envenoming mice displayed hypodynamic condition, clonic head movements, accompanied by bradypnea and thoracoabdominal imbalance. After 7 h of envenoming, the mice showed an ecchymotic region at the injection site, including bleeding in the pleural, liver, and kidney capsules. The effect on the brain revealed a micro-hemorrhage in the sensorimotor cortex with substantial loss of neurons. The venom caused dilated blood vessels in lung tissue, with endothelial necrosis associated with alveolar rupture. The liver showed parenchyma alteration with many extravasated erythrocytes. The kidneys exhibited renal tubules necrosis and a statistically significant increase in creatinine concentration. ALP and ALT's enzymatic activities remained constant at 7 h after envenoming but increased at 12 h. AST and LDH were significantly increased at 7 h but decreased to the near baseline 12 h after venom administration. Massive hemorrhages could trigger a hypovolemic shock, which could lead to death after several h without treatment. Knowledge of P. lansbergii lansbergii snake bites' injuries is essential to make the appropriate diagnostic in human envenoming cases by this snake.


Assuntos
Crotalinae , Mordeduras de Serpentes , Venenos de Serpentes/toxicidade , Animais , Hemorragia/induzido quimicamente , Dose Letal Mediana , Camundongos , Mordeduras de Serpentes/patologia
11.
Toxins (Basel) ; 13(5)2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-34067062

RESUMO

Local tissue swelling, inflammation, and wound necrosis are observed in Taiwan cobra bites. Knowledge of the factors influencing local tissue necrosis after cobra bites might improve the cobra bite treatment strategy. Therefore, we aimed to explore the factors influencing local tissue necrosis after cobra bites. This was a retrospective observational cohort study. All patients clinical presentations including serum venom levels for determining the influential factors in this study were obtained from Hung et al.'s previous study. Clinical features, such as bite information, initial swelling, patient presentation time, serum venom levels, and antivenom, use were extracted. The measurement outcome was the development of wound necrosis. The factors influencing wound necrosis were investigated using univariate and logistic regression analyses. The influential factors of local tissue necrosis and their areas under the curve were: initial limb swelling, 0.88; presentation time × serum level, 0.80; initial necrosis, 0.75; patient presentation time, 0.70. Serum venom level alone cannot be used as a predictive factor. The development of tissue necrosis might be associated with the venom factor, time factor, and their interaction. These influential factors can be used in future studies to evaluate antivenom efficacy.


Assuntos
Antivenenos/administração & dosagem , Venenos Elapídicos/toxicidade , Mordeduras de Serpentes/complicações , Adulto , Animais , Estudos de Coortes , Elapidae , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Necrose/etiologia , Estudos Retrospectivos , Mordeduras de Serpentes/patologia , Mordeduras de Serpentes/terapia , Taiwan
12.
Am J Trop Med Hyg ; 104(5): 1870-1876, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33819174

RESUMO

Envenomation and death resulting from snakebites represent a significant public health problem worldwide, particularly in tropical and subtropical regions. The WHO has defined snakebite as a neglected tropical health concern. Bites from Macrovipera lebetina obtusa usually cause life-threatening systemic hemodynamic disturbances, reduced functionality of the kidneys, and other serious symptoms, including hypotension shock, edema, and tissue necrosis, at the bite site. Herein, we highlight five cases of M. l. obtusa envenomation that presented with wide-ranging manifestations. Many recovered cases were left with long-term musculoskeletal disabilities. In a particular case, a 15-year-old male patient was envenomed in his palm by an 80-cm M. l. obtusa. Within 12 hours, swelling extended to near the shoulder. Fasciotomy was performed on the forearm and part of the upper arm of this patient. Symptoms of severe localized pain and swelling, dizziness, weakness, low blood pressure, and itching around the bite area were documented. The patient remained in the hospital for 13 days.


Assuntos
Antivenenos/uso terapêutico , Edema/tratamento farmacológico , Hipotensão/tratamento farmacológico , Necrose/tratamento farmacológico , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Víboras/toxicidade , Viperidae/fisiologia , Adolescente , Adulto , Animais , Criança , Edema/diagnóstico , Edema/patologia , Edema/cirurgia , Feminino , Antagonistas dos Receptores Histamínicos/uso terapêutico , Humanos , Hipotensão/diagnóstico , Hipotensão/patologia , Hipotensão/cirurgia , Irã (Geográfico) , Loratadina/uso terapêutico , Masculino , Necrose/diagnóstico , Necrose/patologia , Necrose/cirurgia , Mordeduras de Serpentes/diagnóstico , Mordeduras de Serpentes/patologia , Mordeduras de Serpentes/cirurgia , Venenos de Víboras/administração & dosagem
13.
Int J Lab Hematol ; 43(5): 959-965, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33615713

RESUMO

INTRODUCTION: The major systemic manifestation of hemotoxicity in human snakebite envenoming is venom-induced consumption coagulopathy (VICC). A subset of patients with VICC develop thrombotic microangiopathy (TMA), in which acute kidney injury (AKI) occurs. We aimed to investigate the association between schistocytosis in snakebite patients with VICC and AKI, compared to non-envenomed patients. METHODS: Serial blood films collected from a prospective cohort of snakebite patients (Australian Snakebite Project) were examined. Cases were classified a priori as non-envenomed snakebites (normal controls), envenomed without VICC, partial VICC without AKI, complete VICC without AKI, and VICC with AKI based on defined clinical and laboratory criteria. The percentage of schistocytes between groups was compared and correlated by Kendall's tau b test. RESULTS: Seven hundred and eighty blood films from 234 snakebite cases were analyzed. There was a statistically significant correlation (τ = .69, SE .03, P < .001) for schistocytosis between the ordered groups of non-envenomed snakebites, envenomed without VICC, partial VICC without AKI, complete VICC without AKI, and VICC with AKI groups. Patients with VICC and AKI had a platelet nadir median of 42 × 109 /L (interquartile range [IQR] :25-130 × 109 /L), hemoglobin nadir of median 107 g/L (IQR 66-122 g/L), and maximum LDH median of 1128 U/L (IQR 474-3255 U/L). A 1.0% threshold for schistocytosis yielded 90% sensitivity (95% CI: 67%-98%) and 71% specificity (95% CI: 62%-79%) for predicting AKI in patients with VICC. CONCLUSION: Schistocyte quantitation has good diagnostic utility in snakebite patients with VICC. A definition of snakebite TMA as MAHA with ≥1.0% schistocytes and thrombocytopenia, would appear to be appropriate.


Assuntos
Injúria Renal Aguda/etiologia , Coagulação Intravascular Disseminada/etiologia , Eritrócitos/patologia , Mordeduras de Serpentes/complicações , Microangiopatias Trombóticas/etiologia , Injúria Renal Aguda/patologia , Adolescente , Adulto , Austrália/epidemiologia , Coagulação Intravascular Disseminada/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Mordeduras de Serpentes/patologia , Microangiopatias Trombóticas/patologia , Adulto Jovem
14.
Clin Toxicol (Phila) ; 59(1): 28-37, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32400229

RESUMO

INTRODUCTION: Protobothrops mucrosquamatus bite induces wound necrosis, coagulopathy, thrombocytopenia, rhabdomyolysis, and acute renal failure. The severity of the hematological derangements and associated factors for wound necrosis and subsequent surgery and the appropriate management of these conditions have not been well characterized. Although severe renal failure requiring hemodialysis has been reported following P. mucrosquamatus bite, the culprit snake may be erroneously classified. MATERIALS AND METHODS: A total of 186 patients with P. mucrosquamatus bites were retrospectively evaluated. They were categorized into group 1 (patients receiving debridement or finger/toe amputation) and group 2 (all other patients) to identify the associated factors for surgery. Characteristic data were compared between groups 1 and 2 and between definite and suspected cases. RESULTS: No differences were observed between definite and suspected cases in terms of symptomatology and management. Of the 186 patients, 7 (3.8%) were asymptomatic, 179 (96.2%) experienced tissue swelling and pain, and 107 (57.5%) had local ecchymosis. Coagulopathy, thrombocytopenia, and renal impairment were found in 13 (7%), 19 (10.2%), and 7 (3.8%) patients, respectively. None of the patients required transfusion therapy or hemodialysis. Furthermore, no systemic bleeding or death occurred. Antivenom was administered to all 179 envenomed patients at a median of 1.5 h post-bite. The median total dose of the specific antivenom was 5.5 vials. In multivariate logistic regression analysis, finger as the bite site, bullae and blister formation, and wound infection were significantly associated with wound necrosis; whereas finger as the bite site and bullae and blister formation were related to debridement or finger/toe amputation. DISCUSSION AND CONCLUSIONS: Protobothrops mucrosquamatus envenomation mainly exerts effects on local tissue. Systemic effects are uncommon and generally nonsevere and transient after the treatment with the specific antivenom. We speculated that severe renal failure requiring hemodialysis is not a typical finding of P. mucrosquamatus envenomation. Patients with finger as the bite site and bullae or blister formation should be carefully examined for wound necrosis, secondary infection, and subsequent surgery. Further evaluations of the efficacy of antivenom against local tissue effects and the effect of selective antibiotics in the management of bite wound infection are urgently required. Although the antivenom manufacturer suggested a skin test prior to use, we believed that it could be omitted because it does not accurately predict the allergic responses.


Assuntos
Amputação Cirúrgica , Antivenenos/uso terapêutico , Venenos de Crotalídeos/antagonistas & inibidores , Desbridamento , Dedos/cirurgia , Mordeduras de Serpentes/terapia , Dedos do Pé/cirurgia , Trimeresurus , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antibacterianos/uso terapêutico , Antivenenos/efeitos adversos , Criança , Pré-Escolar , Protocolos Clínicos , Venenos de Crotalídeos/metabolismo , Feminino , Dedos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Diálise Renal , Insuficiência Renal/etiologia , Insuficiência Renal/terapia , Estudos Retrospectivos , Mordeduras de Serpentes/sangue , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/patologia , Taiwan , Dedos do Pé/patologia , Trimeresurus/metabolismo , Infecção dos Ferimentos/microbiologia , Infecção dos Ferimentos/terapia , Adulto Jovem
15.
Chem Biol Interact ; 333: 109347, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33259806

RESUMO

Several reports have suggested that photobiomodulation, owing to its analgesic, anti-inflammatory, and healing effects, may be an effective therapeutic option for local effects of snakebites when the availability and accessibility of conventional serum therapy are inefficient and far from medical care centers. Although there have been studies that demonstrate the application of photobiomodulation in the treatment of local adverse events due to snakebites from snakes of the genus Bothrops, its role in the activation of leukocytes, particularly macrophages, has not been evaluated. Here, we assessed the effect of light-emitting diode (LED) treatment on macrophage activation induced by B. jararacussu venom (BjV). LED treatment caused an increase in the viability of macrophages incubated with BjV. This treatment reduced reactive oxygen species (ROS) and nitric oxide (NO) production by macrophages after incubation with BjV. However, LED treatment did not interfere with IL-1ß and IL-10 production by macrophages after incubation with BjV. In conclusion, this study showed that LED treatment has the potential to be used in combination with conventional serum therapy to prevent or minimize the progression of local to severe symptoms after Bothrops envenomation.


Assuntos
Bothrops , Venenos de Crotalídeos/toxicidade , Terapia com Luz de Baixa Intensidade/instrumentação , Macrófagos/efeitos da radiação , Semicondutores , Mordeduras de Serpentes/imunologia , Mordeduras de Serpentes/radioterapia , Animais , Sobrevivência Celular/efeitos dos fármacos , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Espaço Intracelular/efeitos da radiação , Macrófagos/imunologia , Masculino , Camundongos , Óxido Nítrico/biossíntese , Espécies Reativas de Oxigênio/metabolismo , Mordeduras de Serpentes/metabolismo , Mordeduras de Serpentes/patologia , Superóxidos/metabolismo
16.
Am J Trop Med Hyg ; 104(3): 1142-1148, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33319738

RESUMO

We studied whether circulating secretory phospholipase A2 (sPLA2) activity reliably distinguished patients with snakebite envenomation from those with nonvenomous/dry snakebites, and whether patients with progressive local swelling had persistence of circulating sPLA2 activity despite antivenom treatment. We prospectively enrolled adults presenting to the emergency with a history of snakebite in the past 24 hours. We estimated circulating sPLA2 activity at baseline before antivenom administration and after 48 hours in those with envenomation. We enrolled 52 patients with snakebites (mean age 39.3 ± 12.6 years; 35 [67%] men), and 16 patients with infective cellulitis as controls. Thirty patients had local ± systemic envenomation; 15 were classified as dry/nonvenomous bites; and envenomation status was unclear in seven patients. Baseline sPLA2 activity was significantly higher in snakebite patients than that in those with infective cellulitis (4.64 [3.38-5.91] versus 3.38 [1.69-4.01] nmol/minute/mL; P = 0.005). Among patients with snakebites, sPLA2 activity in the highest quartile was significantly associated with envenomation (12 of 27 versus two of 22; P = 0.010). However, median sPLA2 activity did not differ significantly between patients with envenomation and the rest. Baseline sPLA2 activity was significantly associated with the maximum extent of limb swelling (P = 0.031 for trend). In envenomed patients, circulating sPLA2 activity significantly decreased after 48 hours compared with the baseline (5.49 [3.38-8.86] versus 3.38 [2.53-4.64]; P = 0.003) including those with progressive swelling. Although circulating sPLA2 activity was elevated following snakebites, its sensitivity to diagnose envenomation appears to be limited. Administration of more antivenom after systemic manifestations had reversed might not benefit patients with progressive local swelling.


Assuntos
Fosfolipases A2 Secretórias/sangue , Mordeduras de Serpentes/enzimologia , Mordeduras de Serpentes/patologia , Adulto , Estudos de Casos e Controles , Celulite (Flegmão)/enzimologia , Celulite (Flegmão)/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
17.
Am Nat ; 196(6): 690-703, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33211560

RESUMO

AbstractAutotomy, the self-amputation of body parts, serves as an antipredator defense in many taxonomic groups of animals. However, its adaptive value has seldom been quantified. Here, we propose a novel modeling approach for measuring the fitness advantage conferred by the capability for autotomy in the wild. Using a predator-prey system where a land snail autotomizes and regenerates its foot specifically in response to snake bites, we conducted a laboratory behavioral experiment and a 3-year multievent capture-mark-recapture study. Combining these empirical data, we developed a hierarchical model and estimated the basic life-history parameters of the snail. Using samples from the posterior distribution, we constructed the snail's life table as well as that of a snail variant incapable of foot autotomy. As a result of our analyses, we estimated the monthly encounter rate with snake predators at 3.3% (95% credible interval: 1.6%-4.9%), the contribution of snake predation to total mortality until maturity at 43.3% (15.0%-95.3%), and the fitness advantage conferred by foot autotomy at 6.5% (2.7%-11.5%). This study demonstrated the utility of the multimethod hierarchical-modeling approach for the quantitative understanding of the ecological and evolutionary processes of antipredator defenses in the wild.


Assuntos
Características de História de Vida , Regeneração , Caramujos/fisiologia , Mordeduras de Serpentes/patologia , Animais , Teorema de Bayes , Comportamento Animal , Evolução Biológica , Modelos Estatísticos , Comportamento Predatório , Mordeduras de Serpentes/mortalidade , Serpentes
18.
Toxins (Basel) ; 12(11)2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33153179

RESUMO

Snakebite envenoming (SBE) is a public health issue in developing countries. The estimated annual global incidence of snakebites is about 5.4 million snakebites per year, resulting from 1.8 to 2.7 million cases of SBE and from 81,000 to 138,000 deaths with 400,000 survivors suffering permanent physical and psychological disabilities. There are more than 3000 species of snakes around the world: 600 are venomous and over 200 are considered to be medically important because of their clinical effects. The severity of SBE depends on several factors among which bite localization, snake's size, condition of glands and teeth, bite angle and bite duration, the microflora of the snake's mouth and victim's skin, age of the victim, weight, health status, and victim's activity after a bite. Snake venoms are mixtures of protein families, and each of these families contains many different toxins or toxin isoforms. Based on their effects, snake venoms can be classified as hemotoxic, neurotoxic, or cytotoxic and they can all act together involving multiple tissues and organs. When the bite is fatal, the mechanism of death is primarily related to the paralysis of respiratory muscles, which causes asphyxia and hypoxic-ischemic encephalopathy, but also anaphylactic shock, hemorrhagic shock, cardiomyopathy, acute tubular necrosis (ATN). The purpose of this literature review is to evaluate epidemiological and post-mortem examination findings in fatal SBEs in order to better understand the pathophysiological mechanisms, thus helping pathologists in defining the correct diagnosis.


Assuntos
Patologia Legal , Mordeduras de Serpentes/patologia , Venenos de Serpentes/efeitos adversos , Serpentes/classificação , Adolescente , Adulto , Idoso , Animais , Autopsia , Causas de Morte , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Mordeduras de Serpentes/mortalidade , Mordeduras de Serpentes/fisiopatologia , Adulto Jovem
19.
Wilderness Environ Med ; 31(4): 466-469, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33032932

RESUMO

Blood-bellied coral snake (Calliophis haematoetron) is a recently discovered forest-dwelling species of elapid hitherto known from 3 specimens found from central Sri Lanka. Herein we describe the first authenticated case of blood-bellied coral snakebite. The victim, an 11-mo-old infant who received the bite while handling the snake at her home, had mild transient swelling at the bite site. The patient had no clinical or laboratory evidence of systemic envenoming. We highlight the importance of clinicians being aware of the occurrence of this potentially medically important elapid snake in anthropogenic habitats.


Assuntos
Elapidae/classificação , Mordeduras de Serpentes/patologia , Animais , Feminino , Humanos , Lactente , Sri Lanka
20.
Toxicon ; 186: 160-167, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32822734

RESUMO

In the Brazilian Amazon, snakebites are a significant problem, especially for populations in rural areas, particularly in forests, where victims are a considerable distance from hospital care. Several factors are associated with the severity of the accident, such as the size and age of the snake. This study aims to compare the clinical, epidemiological and laboratory aspects of envenomation to the size of Bothrops atrox snakes. Clinical, epidemiological and laboratory variables were collected from patients bitten by B. atrox and who were admitted to a hospital in the city of Cruzeiro do Sul (western Brazilian Amazon). When the two punctures of the teeth were present in the bite sign, the distance between these was measured. When taken to the hospital, the snake was measured; otherwise, its size was estimated via interviews with patients. In 92 cases, the size of the snake was estimated, and most of these were caused by small snakes. Bites of small snakes occur mainly on the feet, while larger specimens reach the legs or higher regions. Small snakes were associated primarily with mild and moderate snakebites, with more presence of hemorrhagic manifestations, while larger snakes were responsible for severe cases and characterized by local effects (necrosis, edema, flictena, compartment syndrome, and infection) and patients were treated with a higher amount of antivenom and for a longer period of hospitalization. The distance of the punctures was related to the size of the snake and the severity of the local envenomation. The observation of the distance between puncture marks when present, which is correlated with the length of the specimen, as well as the estimation of the snake size by the patient, may provide more support for the health professional on the prognosis of envenomation. The use of boots in activities in rural areas and forests could contribute to a lower rate of cases of snakebites, and health education on preventive measures and first aid for populations is fundamental.


Assuntos
Bothrops , Mordeduras de Serpentes/epidemiologia , Animais , Antivenenos , Brasil/epidemiologia , Edema , Feminino , Primeiros Socorros , Humanos , Masculino , Necrose , Mordeduras de Serpentes/patologia , Mordeduras de Serpentes/terapia , Serpentes
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