Incidence, clinical features, and risk factors of hemocoagulase-induced hypofibrinogenemia: A retrospective real-world study.

The objective of this study was to explore the real-world incidence, severity, clinical features, and potential risk factors associated with hypofibrinogenemia induced by hemocoagulase. Based on Chinese Hospital Pharmacovigilance System, a retrospective case-control study was conducted, enrolling hospitalized patients who received hemocoagulase for the treatment or prevention of hemorrhage in Weifang People's Hospital in China from January 2021 to May 2022. Univariate and multivariate logistic regression was performed to analyze the potential risk factors. Out of 10,397 hospitalized patients who received hemocoagulase, 341 patients showed positive triggers, with 235 patients ultimately conformed as hemocoagulase-associated hypofibrinogenemia. The system positive alarm rate was 68.91%, and the overall incidence of hemocoagulase-induced hypofibrinogenemia was 2.26%, predominantly characterized by mild to moderate severity levels. The incidence varied among the 4 types of hemocoagulase, with the highest incidence observed in hemocoagulase Agkistrodon Halys Pallas at 4.59%. The incidence of hemocoagulase from Deinagkistrodon acutus, Bothrops Atrox and Adder were 0.97%, 0.44% and 0.12%, respectively. Multivariate logistic regression analysis revealed that age (odds ratios [OR] = 177.328, P < .001), source of snake venom (OR = 5.641, P < .05), albumin (OR = 2.487, P < .001), and cumulative dosage (OR = 1.106, P < .001) were independent risk factors. Increased risk of hemocoagulase-related hypofibrinogenemia may be associated with children, elderly patients, low albumin levels, high cumulative doses and hemocoagulase from Agkistrodon Halys Pallas. Early recognition and close drug monitoring for these high-risk patients are vital in clinical practice.

Protobothrops jerdonii (Jerdon's pit viper) and Protobothrops himalayanus (Himalayan lance-headed pit viper) bites: Clinical report on envenomings from North-East India, managed through remote consultation by a national-level Poison control center.

Members of the genus Protobothrops are amongst the more than twenty-eight range-restricted Indian pit viper species. Their bites and envenomings are rarely documented from India. Pit viper envenomings can be challenging to treat in the Indian setting, since available antivenoms do not satisfactorily neutralize their venoms. Herein, we present the first Indian reports on bites and envenoming by Protobothrops jerdonii and Protobothrops himalayanus resulting in local effects, coagulopathy and acute kidney injury in the case of the former and possible mild, isolated coagulopathy in the case of the latter; and discuss management-related challenges in the context of absent specific antivenoms.

Biochemical and toxicological profiles of venoms from an adult female South American bushmaster (Lachesis muta rhombeata) and her offspring.

In this work, we compared the biochemical and toxicological profiles of venoms from an adult female specimen of Lachesis muta rhombeata (South American bushmaster) and her seven offspring born in captivity, based on SDS-PAGE, RP-HPLC, enzymatic, coagulant, and hemorrhagic assays. Although adult and juvenile venoms showed comparable SDS-PAGE profiles, juveniles lacked some chromatographic peaks compared with adult venom. Adult venom had higher proteolytic (caseinolytic) activity than juvenile venoms (p < 0.05), but there were no significant inter-venom variations in the esterase, PLA2, phosphodiesterase and L-amino acid oxidase (LAAO) activities, although the latter activity was highly variable among the venoms. Juveniles displayed higher coagulant activity on human plasma, with a minimum coagulant dose ∼42% lower than the adult venom (p < 0.05), but there were no age-related differences in thrombin-like activity. Adult venom was more fibrinogenolytic (based on the rate of fibrinogen chain degradation) and hemorrhagic than juvenile venoms (p < 0.05). The effective dose of Bothrops/Lachesis antivenom (produced by the Instituto Butantan) needed to neutralize the coagulant activity was ∼57% greater for juvenile venoms (p < 0.05), whereas antivenom did not attenuate the thrombin-like activity of juvenile and adult venoms. Antivenom significantly reduced the hemorrhagic activity of adult venom (400 µg/kg, i. d.), but not that of juvenile venoms. Overall, these data indicate a compositional and functional ontogenetic shift in L. m. rhombeata venom.

The establishment and evaluation of a swine model of deinagkistrodon acutus snakebite envenomation.

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.

In vitro immunoreactivity and in vivo neutralization of Trimeresurus gracilis venom with antivenoms targeting four pit viper species.

Snakebite envenomation is a significant global health issue that requires specific antivenom treatments. In Taiwan, available antivenoms target a variety of snakes, but none specifically target Trimeresurus gracilis, an endemic and protected species found in the high mountain areas of Taiwan. This study evaluated the effectiveness of existing antivenoms against T. gracilis venom, focusing on a bivalent antivenom developed for Trimeresurus stejnegeri and Protobothrops mucrosquamatus (TsPmAV), as well as monovalent antivenoms for Deinagkistrodon acutus (DaAV) and Gloydius brevicaudus (GbAV). Our research involved in vivo toxicity testing in mice and in vitro immunobinding experiments using (chaotropic) enzyme-linked immunosorbent assays, comparing venoms from four pit viper species (T. gracilis, T. stejnegeri, P. mucrosquamatus, and D. acutus) with three types of antivenoms. These findings indicate that TsPmAV partially neutralized T. gracilis venom, marginally surpassing the efficacy of DaAV. In vitro tests revealed that GbAV displayed higher binding capacities toward T. gracilis venom than TsPmAV or DaAV. Comparisons of electrophoretic profiles also reveal that T. gracilis venom has fewer snake venom C-type lectin like proteins than D. acutus, and has more P-I snake venom metalloproteases or fewer phospholipase A2 than G. brevicaudus, T. stejnegeri, or P. mucrosquamatus. This study highlights the need for antivenoms that specifically target T. gracilis, as current treatments using TsPmAV show limited effectiveness in neutralizing local effects in patients. These findings provide crucial insights into clinical treatment protocols and contribute to the understanding of the evolutionary adaptation of snake venom, aiding in the development of more effective antivenoms for human health.

Indian green pit vipers: A lesser-known snake group of north-east India.

Green pit vipers are one of the most widely distributed group of venomous snakes in south-east Asia. In Indian, green pit vipers are found in the Northern and North-eastern states spreading across eastern and central India and one of the lesser studied venoms. High morphological similarity among them has been a long-established challenge for species identification, however, a total of six species of Indian green pit viper belonging to genus Trimeresurus, Popeia and Viridovipera has been reported from North-east India. Biochemical and biological studies have revealed that venom exhibits substantial variation in protein expression level along with functional variability. The symptoms of envenomation are painful swelling at bite site, bleeding, necrosis along with systemic toxicity such as prolonged coagulopathy. Clinical data of green pit viper envenomated patients from Demow community health centre, Assam advocated against the use of Indian polyvalent antivenom pressing the need for a suitable antivenom for the treatment of green pit viper envenomation. To design effective and specific antivenom for green pit vipers, unveiling the proteome profile of these snakes is needed. In this study, a comparative venomic of green pit vipers of Northern and North-eastern India, their clinical manifestation as well as treatment protocol has been reviewed.

Comparative analysis of Deinagkistrodon acutus venom from Taiwan and China utilizing chromatographic, electrophoretic, and bioinformatic approaches, along with ELISA employing a monospecific antivenom.

Deinagkistrodon acutus is a medically important pitviper inhabiting mainly South China and Taiwan. The hemorrhagic effects of its envenoming are compatible to its venom, which is abundant in metalloproteases (svMPs) and C-type lectin-like proteins. In this study, we investigated geographic variations in the venom of D. acutus collected from Taiwan and four Mainland Chinese provinces: Fujian, Jiangxi, Anhui, and Hunan. The variations were assessed through high-performance liquid chromatography, non-metric multidimensional scaling analysis, gel electrophoresis, and enzyme-linked immunosorbent assay (ELISA) with a monospecific antivenom (DaMAV) generated against the Taiwanese D. acutus venom, and discussed based on venom-protein sequences in databases and literature related to D. acutus venom. Additionally, the cross-reactivity of DaMAV against Crotalus horridus and Calloselasma rhodostoma venoms was investigated. We noted differential abundances of D. acutus venom metalloproteases, C-type lectin-like proteins, and phospholipase A2, along with point mutations and selective expression of serine protease isoforms. The ELISA results revealed that the venom from Taiwan was more reactive toward Taiwanese DaMAV than the four Mainland Chinese venoms, consistent with chromatographic profile differences, whereas C. horridus venom presented moderate cross-reactivity with DaMAV. The observed immunoreactivities of these venom with DaMAV can be attributed to the high prevalence of their PIII-svMPs, which are the dominant antigens, and the conservation of PIII-svMP epitopes.

Panicolytic-like effects of environment enrichment on male mice threatened by Bothrops jararaca lancehead pit vipers.

Environment enrichment (EE) is a well-known eustress model showing beneficial effects in different psychiatric diseases, but its positive properties in panic disorders are not yet established. The confrontation between prey and predator in complex arenas has been validated as a putative panic attack model. The principal aim of this work was to investigate the role of the EE on panic-like defensive responses elicited by mice threatened by venomous snakes. After 6 weeks of exposure either to an enriched or standard environments, 36 male mice were habituated in a complex polygonal arena for snakes containing an artificial burrow and elevated platforms for escape. The animals were confronted by Bothrops jararaca for 5 min, and the following antipredatory responses were recorded: defensive attention, stretched attend posture, flat back approach, prey versus predator interaction, oriented escape behavior, time spent in a safe place, and number of crossings. Mice threatened by snakes displayed several antipredatory reactions as compared to the exploratory behavior of those animals submitted to a nonthreatening situation (toy snake) in the same environment. Notably, EE causes anxiolytic- and panicolytic-like effects significantly decreasing the defensive attention and time spent in safe places and significantly increasing both prey versus predator interaction and exploratory behavior. In conclusion, our data demonstrate that EE can alter the processing of fear modulation regarding both anxiety- and panic-like responses in a dangerous condition, significantly modifying the decision-making defensive strategy.

Envenomation by Eyelash Viper Bothriechis schlegelii (Berthold, 1846) in Southwestern Colombia.

INTRODUCTION: Bothriechis schlegelii is a Crotaline viperid species of Central America and Northern South America. The characteristics of its envenomation have not been well established. We present clinical characteristics of human cases evaluated and treated in a hospital in southwestern Colombia. METHODS: We evaluated data from patients who suffered Bothriechis schlegelii envenomation and were seen at Fundación Valle del Lili Hospital, Cali, Colombia between 2011 and 2022. RESULTS: Eight patients were included, with a median age of 24 years. Snakebites occurred in rural areas. Six (75%) patients were bitten on the upper extremities in relation to the arboreal habits of this animal. The most common symptoms were pain and edema (N = 8, 100%), ecchymoses (N = 2, 25%), and paresthesia (N = 2, 25%). The most common systemic findings were hypofibrinogenemia (N = 8, 100%) and prolonged prothrombin time in five patients (N = 5, 62.5%). All were treated with polyvalent antivenom for Colombian snakes, with a good response and outcome. CONCLUSIONS: Most bite sites from B. schlegelii were on the upper limbs. All patients had both local manifestations, including edema, pain, and systemic effects with hypofibrinogenemia, but none had systemic bleeding. Every patient received antivenom and had favorable outcomes.

A bifurcation integrates information from many noisy ion channels and allows for milli-Kelvin thermal sensitivity in the snake pit organ.

In various biological systems, information from many noisy molecular receptors must be integrated into a collective response. A striking example is the thermal imaging organ of pit vipers. Single nerve fibers in the organ reliably respond to milli-Kelvin (mK) temperature increases, a thousand times more sensitive than their molecular sensors, thermo-transient receptor potential (TRP) ion channels. Here, we propose a mechanism for the integration of this molecular information. In our model, amplification arises due to proximity to a dynamical bifurcation, separating a regime with frequent and regular action potentials (APs), from a regime where APs are irregular and infrequent. Near the transition, AP frequency can have an extremely sharp dependence on temperature, naturally accounting for the thousand-fold amplification. Furthermore, close to the bifurcation, most of the information about temperature available in the TRP channels' kinetics can be read out from the times between consecutive APs even in the presence of readout noise. A key model prediction is that the coefficient of variation in the distribution of interspike times decreases with AP frequency, and quantitative comparison with experiments indeed suggests that nerve fibers of snakes are located very close to the bifurcation. While proximity to such bifurcation points typically requires fine-tuning of parameters, we propose that having feedback act from the order parameter (AP frequency) onto the control parameter robustly maintains the system in the vicinity of the bifurcation. This robustness suggests that similar feedback mechanisms might be found in other sensory systems which also need to detect tiny signals in a varying environment.

Clinical Laboratory Investigations and Antivenom Administration after Malayan Pit Viper (Calloselasma rhodostoma) Envenoming: A Retrospective Study from Southernmost Thailand.

The Malayan pit viper (MPV: Calloselasma rhodostoma) is a medically important venomous snake causing numerous envenomations in Thailand. Administration of specific snake antivenom is the only effective treatment for MPV-envenomed patients. However, inappropriate administration or misuse of snake antivenom is problematic in some remote areas of tropical countries where the snakebite envenoming rate is notable. Currently, the indications for administration of MPV antivenom are focused mainly on hematological factors. These include 1) venous clotting time > 20 min, 2) unclotted 20-minute whole-blood clotting time, 3) international normalized ratio > 1.2, 4) platelet count < 50 × 103/µL, 5) systemic bleeding, and 6) impending compartment syndrome. We aimed to determine the association between laboratory data and antivenom administration in MPV-envenomed patients. A retrospective study of data from 2016 to 2021 in Narathiwat Province, the southernmost province in Thailand, was conducted. A total of 838 MPV-bitten patients were included in this study. Local effects and systemic effects were observed in 58.8% and 27.7% of patients, respectively. Coagulopathies, which range from abnormal blood clotting to systemic bleeding, represented the majority of systemic effects. Acute kidney injury developed in 2.5% of patients. In this study, 57.3% of patients were considered appropriate antivenom recipients. Interestingly, the present study revealed that local bleeding and mild to moderate thrombocytopenia became the independent factors for inappropriate use of MPV antivenom. Reeducation and supervision regarding the rational use of snake antivenom are needed to minimize the misuse of antivenom.

Structural, biochemical and immunochemical characterization of an acidic phospholipase A2 from Lachesis acrochorda (Viperidae: Crotalinae) venom.

Viperids of the genus Lachesis, also known as bushmasters, are capable of injecting great amounts of venom that cause severe envenomation incidents. Since phospholipases type A2 are mainly involved in edema and myonecrosis within the snakebite sites, in this work, the isolation, amino acid sequence and biochemical characterization of the first phospholipase type A2 from the venom of Lachesis acrochorda, named Lacro_PLA2, is described. Lacro_PLA2 is an acidic aspartic 49 calcium-dependent phospholipase A2 with 93% similarity to the L. stenophrys phospholipase. Lacro_PLA2 has a molecular mass of 13,969.7 Da and an experimental isoelectric point around 5.3. A combination of N-terminal Edman degradation and MS/MS spectrometry analyses revealed that Lacro_PLA2 contains 122 residues including 14 cysteines that form 7 disulfide bridges. A predicted 3D model shows a high resemblance to other viperid phospholipases. Nevertheless, immunochemical and phospholipase neutralization tests revealed a notorious level of immunorecognition of the isolated protein by two polyclonal antibodies from viperids from different genus, which suggest that Lacro_PLA2 resembles more to bothropic phospholipases. Lacro_PLA2 also showed significantly high edema activity when was injected into mice; so, it could be an alternative antigen in the development of antibodies against toxins of this group of viperids, seeking to improve commercial polyclonal antivenoms.

Prolonged venom-induced consumptive coagulopathy following Mangshan pit viper (Protobothrops mangshanensis) envenomation despite Hemato Polyvalent antivenom administration.

This case report summarizes an envenomation by the Mangshan pit viper (Protobothrops mangshanensis), a rare, endangered, venomous snake endemic to Mount Mang of China, and the first reported use of Hemato Polyvalent antivenom (HPAV) for this species. The snakebite occurred in a United States zoo to a 46-year-old male zookeeper. He presented via emergency medical services to a tertiary center after sustaining a single P. mangshanensis bite to the abdomen and was transported with antivenom from the zoo. Within 2 hours of envenomation, he developed oozing of sanguineous fluid and ecchymosis at the puncture site, and about 4 hours post-bite, was treated with HPAV. His coagulation profile fluctuated with the following pertinent peak/nadir laboratory values and corresponding hospital day (HD): undetectable fibrinogen levels, d-dimer 8.89 mg/L and 7.43 mg/L, and INR 2.97 and 1.46 on HD zero and three, respectively. Other peak/nadir values included hemoglobin 9.7 g/dL and creatinine phosphokinase 2410 U/L on HD four and platelets 81 × 109/L on HD seven. The patient received a total of 30 vials of HPAV over 5 days and 1 unit of cryoprecipitate on HD six. Upon discharge on HD eight, laboratory studies were normalizing, except for platelets, and edema stabilized. This case describes an acute, recurrent, and prolonged venom-induced consumptive coagulopathy despite prompt administration and repeated doses of HPAV.

Thromboembolic events following a pit viper bite from Protobothrops mucrosquamatus (Taiwan Habu): A report of two cases.

Protobothrops mucrosquamatus, also known as the Taiwan Habu, is a venomous snake prevalent in Taiwan. It is accountable for most snakebites in the region. The toxin of the Taiwan Habu has significant hemorrhagic potential. However, patients bitten by this snake often suffer more local injuries than systemic ones. This report presents two cases of individuals bitten by the Taiwan Habu who subsequently experienced thromboembolism. In the first case, an 88-year-old male, bitten on his fourth toe, suffered a cerebral infarction 32 hours post-bite. In the second case, an 82-year-old female, bitten on her ankle, experienced cardiac arrest 19 hours later. Both patients promptly received antivenom and showed no signs of coagulopathy either before or after the snakebite. However, elevated coagulation factor VIII levels were observed in the first case. Our aim is to understand the mechanism behind these thromboembolic events. This report emphasizes the unusually high level of coagulation factor VIIIa and highlights the need for further investigation into the mechanisms involved. Consequently, physicians should assess the risk of thromboembolic events in snakebite patients by evaluating coagulation factors during treatment.

Incidence and Risk Factors for Wound Infections after Trimeresurus stejnegeri Snakebites in Taiwan.

Snakebite envenomation is a neglected tropical disease. Taiwan, with its subtropical and Southeast Asian environment, provides suitable habitat for several venomous snake species. Trimeresurus stejnegeri, an arboreal pit viper, is the most common cause of venomous snakebite in Taiwan. Trimeresurus stejnegeri envenomation can cause local swelling, occasional ecchymosis, and wound infection. The primary treatment of T. stejnegeri envenomation is the binary antivenom, vacuum freeze-dried F(ab')2 fragments of equine antibodies, against T. stejnegeri and Protobothrops mucrosquamatus. This study aimed to analyze the incidence of post-envenomation wound infections caused by T. stejnegeri based on data collected over a decade from institutions affiliated with the Chang Gung Memorial Hospital in Taiwan. A total of 254 patients were enrolled in this study. Clinical and laboratory data, treatment information, and patient outcomes were extracted from electronic medical records. Wound infection was associated with delay in antivenom initiation (adjusted odds ratio: 3.987; 95% CI: 1.406-11.302). The infection rates were 20.5%, 12.5%, 31.3%, and 48.1% for antivenom administration within 2 hours, 2-4 hours, 4-6 hours, and > 6 hours, respectively. Therefore, early initiation of antivenom treatment (within 6 hours) is recommended. Morganella morganii was cultured from wounds of the patients, whereas Enterobacter cloacae and Enterococcus faecalis were cultured from both the oral cavity of snakes and the wounds of the patients. For post-envenomation patients who develop a local infection, empiric antibiotics such as third-generation cephalosporins, quinolones, and piperacillin/tazobactam are recommended because snakebite wound infections are often polymicrobial in nature.

Effects of environmental factors and intraspecific niche overlap on the body and ecological characteristics of red-tongued pit vipers (Gloydius ussuriensis).

The body condition of a snake species provides important physiological, morphological, and ecological information that elucidates its habits, life cycle, and competitive relationships. We measured the body size and condition of the wild Gloydius ussuriensis population in South Korea from 2018 to 2022, analyzed the degree of intraspecific niche overlap, and identified the geographic and climatic factors affecting their body condition. We found that the females were longer than the males. The body condition index (BCI) of G. ussuriensis differed depending on sex and season; the BCI of the females and males was highest in August and October, respectively. Environmental factors related to altitude and temperature affected the body condition of G. ussuriensis; BCI increased as the mean annual temperature and winter temperature increased; however, it increased when the annual temperature range decreased. The mean Pinaka index was 0.96, indicating a high degree of niche overlap; however, the niche overlap among the neonates was less than that among the adults and juveniles. To elucidate the causes of niche overlap and mechanisms behind the intraspecific competition among G. ussuriensis individuals, the habitat and utilization of food resources at different development stages of G. ussuriensis should be further investigated.

Hematology and biochemistry parameters of the Central American bushmaster (Lachesis stenophrys) under human care in Costa Rica.

Background: The Central American bushmaster (Lachesis stenophrys) is one of the largest pitvipers in the Americas, with relatively low abundance, suspected population declines, and continuing loss, fragmentation, and habitat degradation. Aim: Conservation actions, both in the wild and in captivity, bear the need for health parameters that allow managers and veterinarians to have a better understanding of health, especially when there are relatively few individuals in captivity to obtain robust information since there is no published information on the genus. To have hematological and biochemical reference ranges on the genus Lachesis. Methods: Blood samples were collected from 32 individuals (18 females and 14 males) under human care from 7 zoological institutions from August 2022 to January 2023 and performed hematological and biochemical analyses. Results: Reference intervals of hematological analytes included packed cell volume (17.51%-37.27%), total red blood cell count (0.36-0.92 × 1012/l), hemoglobin (61.73-145.23 g/l), white blood cell count (3.18-13.79 × 109/l), lymphocytes (2.16%-11.23%), azurophils (0.50%-4.20%), monocytes (0.00%-0.21%), heterophils (0.05%-1.12%), eosinophils (0.00%-0.19%), basophils (0.00%-2.00%), and total thrombocyte count (0.68-6.68 × 109/l), and biochemistry reference intervals included total protein (41.76-111.31 g/l), albumin (11.46-28.69 g/l), globulins (29.25-85.14 g/l), aspartate aminotransferase (1.44-68.75 U/l), creatinine kinase (52.72-625.00 U/l), uric acid (20.02-438.53 µmol/l), glucose (0.68-3.29 mml/l), cholesterol (41.74-13.25 mmol/l), calcium (1.78-6.06 mmol/l), and phosphorus (0.72-2.26 mmol/l). Conclusion: This is the first report on the genus Lachesis reporting hematological and biochemical reference ranges.

The Brazilian Atlantic Bushmaster Lachesis (Linnaeus, 1766) Mitogenome With Insights On Snake Evolution And Divergence (Serpentes: Viperidae: Crotalinae).

This study presents the first complete mitogenome of the Brazilian Atlantic bushmaster Lachesis with insights into snake evolution. The total length was 17,177 bp, consisting of 13 PCGs, 22 tRNAs, two rRNAs and a duplicate control region (CRs). Almost all genes were encoded by the heavy-strand, except for the ND6 gene and eight tRNAs (tRNA-Gln, Ala, Asn, Cys, Tyr, Ser[TGA anticodon], Glu, Pro). Only ATG, ATA, and ATC were starting codons for protein-coding sequences. Stop codons mainly were TAA, AGA, AGG, and TAG; whereas ND1, ND3, and CYTB terminated with incomplete stop codons. Phylogeny retrieved Lachesis within the Crotalinae as the sister group of Agkistrodon; and the Lachesis+Agkistrodon clade as the sister group of (Sistrurus+Crotalus)+Bothrops. The tree supports Crotalinae, Viperinae, and Azemiopinae in the Viperidae family, being sister taxa of Colubridae+(Elapidae+Psammophiidae). The mean genetic distance across 15 snake families and 57 nucleotide sequences was 0.37. The overall mean value of genetic distance across the Crotalinae was 0.23, with Lachesis muta exhibiting the shortest distance of 0.2 with Agkistrodon piscivorus, Protobothrops dabieshanensis and P. flavoviridis and the greatest 0.25 with Gloydius blomhoffii, Trimeresurus albolabris, S. miliarius, and Deinagkistrodon acutus. The complete Atlantic L. muta mitogenome presented herein is only the third annotated mitogenome from more than 430 described Brazilian snake species.

Thromboelastographic evaluation in dogs with Asian pit viper (Gloydius) envenomation.

The objective of this study was to investigate the thromboelastography (TEG) variables and platelet count after Asian pit viper (Gloydius) envenomation in dogs compared with healthy control dogs. Ten dogs with snake envenomation and twenty healthy dogs were included. There was a significant decrease in G (P=0.017), maximum amplitude (MA) (P=0.012), angle value (P=0.041), platelet count (P<0.001, as well as an increase in K value (P=0.034) and R value (P=0.007) in dogs with snake envenomation. The results of this study revealed that dogs with Asian pit viper (Gloydius) envenomation showed a hypocoagulable state compared with healthy dogs. Our findings may support the use of TEG for diagnosing and monitoring coagulopathy after Asian pit viper (Gloydius) envenomation in dogs.

Long-term health manifestations of hump-nosed pit viper (Genus: Hypnale) bites.

INTRODUCTION: The hump-nosed pit viper (Genus: Hypnale) is a highly medically significant snake in Sri Lanka, responsible for the majority of venomous snakebites (22-77%). They are found throughout Sri Lanka and the Western Ghats region of India. The venom can lead to two types of effects: acute and long-term. Acutely, bites often result in local symptoms, with less common systemic effects such as acute kidney injury, venom-induced consumption coagulopathy, and thrombotic microangiopathy. METHODS: We conducted a prospective observational study at Teaching Hospital Ratnapura, Sri Lanka, spanning six years, starting in June 2015. Patients bitten by hump-nosed pit vipers were followed up for two years, with assessments every three months to identify long-term effects. Data was gathered through interviewer-administered questionnaires. RESULTS: Out of 728 patients bitten by hump-nosed pit vipers, 22 (3%) were lost to follow-up. Forty-four (6.2%) experienced long-term effects, including chronic kidney disease (24; 3.4%), chronic wounds (five; 0.7%), amputations (five; 0.7%), fasciotomy-related wounds (four; 0.6%), and psychological illnesses (four; 0.6%). There were nine (1.3%) deaths in this group. Among those with chronic effects, 27 (61%) were males, and 17 (39%) were females, with ages ranging from 29 to 82 years (mean 57.6 years). The time it took to diagnose acute kidney injury from the snakebite was 18 h (interquartile range: 15-23.5 h), while the time to diagnose chronic kidney disease was 69 days (interquartile range: 64-74.75 days). In these patients, the estimated glomerular filtration rate was 29.3 mL/min/1.73 m2 (interquartile range: 14-50.75 mL/min/1.73 m2). Among the patients who did not develop long-term complications (662; 91%) 660 (90.7%) experienced local effects, and 82 (11.3%) developed systemic manifestations, including acute kidney injury in 60 (8%) and coagulopathy in 35 (5%). CONCLUSION: Following hump-nosed pit viper bites, a subset of patients may experience long-term health complications, including chronic kidney disease, chronic ulcers, amputations, fasciotomy-related wounds, and psychological illnesses, with chronic kidney disease being the most frequently observed among these manifestations.