Identifying Intraspecific Variation in Venom Yield of Chinese Cobra(Naja atra) from Ten Populations in China's Mainland

Detailed information on venom yield is helpful in preparing antivenoms and treating snakebites, but such information is lacking for many species of venomous snakes. The Chinese cobra(Naja atra) is a large sized, venomous snake commonly found in southeastern China, where it causes a heavy burden of snakebites. To examine the effects of various factors(morphology, sex, age, season, and geographical origin) on the venom yield in this snake, we collected venom samples of 446 individuals(426 adults and 20 neonates) from 10 populations of N. atra over an eightyear period. We used two variables, lyophilized venom mass(venom yield) and solid content of venom(% solids), to quantify the venom yield. We used linear regression analysis to check if venom yield was related to morphological factors, one-way ANOVA and one-way ANCOVA to detect the sexual, ontogenetic, and geographic variation in venom yield, and repeated-measures ANOVA to examine seasonal shifts in venom yield. Our results indicate that venom yield of N. atra is positively related to the morphological traits examined, with male snakes expelling more venom than females. Venom yield in N. atra was age-related, with elder snakes always expelling more venom than younger ones. Geographic variation in venom yield was also observed, while seasonal variation was not. The solid content of venom was lower in males than in females, but this was not related to morphology, season, age, or geography. Our findings suggest that venom yield in N. atra is influenced by multiple factors, as well as by the interactions among these factors.

Early severity predictors of snakebite envenomation in the southern region of Tunisia: a multivariate analysis

Objective:To identify the early predictors of severe envenomation in the southern region of Tunisia.Methods:It was a retrospective monocentric study including consecutive patients admitted to the emergency department for snakebite envenomation.Snakebite envenomation was defined by a history of snakebite.Predictors of severe envenomation were determined by univariate and multivariate analyses.Results:Our sample consisted of 109 patients aged 30(20-44)years with a 1.1:1 sex-ratio(56 males and 53 females).During the 24-hour surveillance period,25 patients developed severe envenomation(22.9%).The in-hospital mortality rate was 4.6%(n=5).The independent predictors of severe snakebite envenomation were leucocyte count over 11550/mm3(OR:18.7,95%CI:3.3-107.8),creatine kinase over 155 IU/L(OR:6.16,95%CI:1.1-35.6),and/or tourniquet before arrival to the ED(OR:32.14,95%CI:3.5-295.9).Conclusions:This study emphasizes the importance of early evaluation of snakebite envenomation.Further studies are required to approve a severity scale proper to snakebite envenomation in Tunisia.

Ethnobotanical survey of folklore plants used in treatment of snakebite in Paschim Medinipur district,West Bengal

Objective:To investigate and collect information from traditional health healers/tribal communities on the use of medicinal plants for treatment of snakebite.Methods:The ethno-medicinal study was conducted in 8 villages of the Paschim Medinipur district of West Bengal in 2012-2013 through questionnaire and personal interviews.Following the method of Martin,information about medicinal plants used in snake bite,precise plant parts used,methods of treatment and administration was enquired from the tribal communities(Santhals,Mundas,Lodhas,Bhumijs,Oram Kherias) of the region.Results:The present study enumerates 20 ethnomedicinal plant species belonging to 16 families used by the tribal communities and medicinal healers of Paschim Medinipur district,West Bengal in treatment of snakebite.Each plant species has been listed alphabetically according to its botanical name,family,vernacular name,part(s) used,mode of preparation/administration.Conclusions:The importance of traditional medicinal system among the tribal communities of Paschim Medinipur district of West Bengal has been highlighted in the present study.

Bilateral parotid enlargement following snake bite:A rare sign

Snakebite is a common medical emergency in India.Unusual complications may occur after viper bite.Bilateral parotid enlargement after viper bite is a rare entity.An 18-year old gentleman presented to our hospital with history of viper bite.On examination he had cellulitis of right lower limb.He developed swelling of both the parotid glands 12 h after admission.He developed coagulopathy,acute renal failure and died within 48 h of hospital admission.Development of parotid swelling after snake bite is associated with poor prognosis.This case is found worth reporting as it is an unusual complication having prognostic value.

An effective snakebite first aid training method for medics in the Chinese troops: a RCT

Background:Snakebites can lead to lifelong consequences and is one of the main causes of death among military troops worldwide.However,few Chinese military medics know the proper first aid procedures for snakebites.Therefore,this study aimed to explore the impact of the Standard Operation Procedure(SOP)and checklist on Chinese military medics’ability to manage snakebite first aid.Methods:This study was a prospective single-blind randomized controlled trial conducted in a military medical university of China from May to June 2017.A questionnaire-based survey was performed to collect the participants’socio-demographic profiles before the baseline measurement.During the baseline measurement,participants were requested to provide corresponding first aid that was responsive to the simulative situation portrayed by the standardized patients(SPs)and the evaluators then scored their performances according to a checklist for snakebite first aid scoring table.After the baseline measurement,they were randomly assigned to one of three intervention groups after stratification according to their baseline performance scores:group A received a self-learning course with textbooks(n=27),group B received a self-learning training on the SOP and checklist(n=27)and group C was engaged in an interactive discussion panel regarding the SOP and checklist(n=26).After the interventions,participants received outcome measurements about snakebite first aid key points capability from the same evaluator and SP for each group to avoid observational error.The reviewers were blinded about the grouping in the trial.Results:The baseline measurement yielded no significant difference(H=1.647,P=0.439)among the three groups.The post-intervention scores were higher than the pre-intervention scores for all three(A,B and C)groups(P=0.008,P<0.001 and P<0.001,respectively).There was significant difference of the post-intervention scores among the three groups(F=8.841,P<0.001).Both post-intervention scores of group B and group C were higher than that of group A(P<0.001 and P=0.001,respectively),but no difference was found between group B and C(P=0.695).The acceptance questionnaire score of SOP and checklist was mostly very satisfied,as the final scores of group B and group C were 4.62±0.61 and 4.82±0.45,respectively.Conclusions:In this study,the implementation of an SOP and checklist for snakebite first aid was shown to update and improve first aid treatment concepts in military medics.These intervention methods played an important role in improving the medics’cognition and understanding of snakebite first aid.Therefore,this finding suggests that SOP and checklist training should be further implemented in Chinese troops for snakebite care.

Epidemiological analysis of snakebite victims in southwestern Iran

Objective:To investigate the prevalence of snakebites and associated epidemiologic factors in Khorram-shahr County,Iran,between 2013 and 2017.Methods:This was a cross-sectional descriptive-analytical study.Information was collected and recorded via questionnaires.Snakebite data included gender,age,occurrence regions,bite site,time of being bitten,month and season.Data were analyzed by Chi-square and t-tests with SPSS version 18.Results:A total of 102 cases of snakebites occurred in Khorram-shahr County of Khuzestan Province,southwestern Iran.There were 75 men(73.5%)and 27 women(26.4%),without significant difference in incidence.The highest frequency of snakebites was observed in the age group of 41-50 years with 28 cases(27.4%).In total,58 cases(56.9%)occurred in urban areas and 44 cases(43.1%)in rural areas.No statistically significant difference was observed between the age groups or residential areas.Snakebites occurred in May with 19 cases(18.6%),spring with 45(44.1%)and summer with 45(44.1%).The results showed significant difference among different seasons and months of the year.Snakebites were in feet in 62 cases(60.8%)and hands in 36 cases(35.3%)which were bitten more than other organs,respectively,with significant difference among different bite sites in the body.The highest and lowest frequencies of snakebites were observed between 18:00 and 24:00 with 43 cases(42.2%)and between 6:00 and 12:00 with 14 cases(13.7%),with a significant difference among different hours of the day.Conclusions:Useful information about snakebites,venomous snakes,their hazards,prevention of bites and the importance of early hospital referral and treatment of victims should be provided to people using different educational tools.

Changes in hippocampal histamine receptors in rats after treatment with Trimeresurus albolabris venom

BACKGROUND： It has been demonstrated that histamine and its receptors in the hippocampus play an important role in memory and/or learning behaviors.OBJECTIVE： To investigate the expression levels of the histamine receptor gene and protein in the hippocampi of rats prior to and after administration of Trimeresurus albolabris venom using reverse transcription-polymerase chain reaction （RT-PCR） and Western blot techniques. DESIGN, TIME AND SETTING： A controlled observation based on cellular protein level was performed in the College of Life Sciences, Chongqing Normal University between March 2005 and April 2007. MATERIALS： Eighty adult male Sprague-Dawley rats were provided by the Laboratory Animal Center of the Third Military Medical University of Chinese PLA. The lyophilized powder of Trimeresurus albolabris venom was collected from Jin-Hu-Shan in Chongqing, China. METHODS： Twenty rats were randomly and evenly divided into an experimental group and a control group The experimental group was subcutaneously injected with 0.65 mg/mL Trimeresurus albolabris venom, 0.5 mL for each rat. The control group was subcutaneously injected with an equal amount of 0.9% physiological saline. Prior to and after injection, rats from these two groups were placed in the Morris Water Maze for recording of path length and escape latency. The remaining 60 rats were randomly allocated to another experimental group （n = 50） and another control group （n = 10）. Rats were correspondingly injected as described above. At different time points （0.1, 0.5, 1, 2, and 3 hours after injection）, rats were decapitated and bilateral hippocampal tissues were dissociated （approximately 100 mg for each sample）. Then, the acquired hippocampal tissue was immediately preserved at -70 ℃ for subsequent experiments. MAIN OUTCOME MEASURES： （1） The levels of histamine receptor （including H1R, H2R, and H3R） mRNA and protein in the hippocampi of rats were measured prior to and after injection of Trimeresurus albolabris venom using RT-PCR and Western Blot techniques. （2） Escape latency （namely, time to reach a platform） and path length were examined by Morris Water Maze testing. RESULTS： All 80 rats were included in the final analysis. In the experimental group, the level of mRNA for H3R receptor in rat hippocampi was just slightly changed, but the level of H3R receptor protein was significantly down-regulated compared with that in the control group （P 〈 0.05）. Both mRNA and protein levels for H1R receptor were initially downregulated and then recovered to normal levels. Expression of H2R receptor mRNA was initially upregulated, then downregulated, and finally restored to the control level. The level of H2R receptor protein showed a tendency for downregulation. In the Morris Water Maze testing, escape latency and path length were significantly longer in the experimental group than in the control group （P 〈 0.05）. CONCLUSION： Within three hours of injection with Trimeresurus albolabris venom, mRNA and protein levels of most histamine receptors in rat hippocampi were downregulated. Such changes possibly contribute to an impairment of memory and/or learning behaviors in rats following injection of Trimeresurus albolabris venom.

Critical lower extremity ischemia after snakebite: A case report

BACKGROUND Globally,the estimated annual incidence of snakebites is approximately 5 million,and approximately 100000 deaths occur from snakebites annually.Local tissue reaction,haemorrhagic clotting disorder,nephrotoxicity,and neurotoxicity are very common effects of snake envenomation,but other rarer complications,such as thrombosis,may also occur as a result of underlying disease.In the treatment of snakebite patients,attention should be paid to the patient’s underlying diseases to avoid serious and catastrophic consequences secondary to snakebite.CASE SUMMARY We report a 69-year-old man with critical right lower extremity pain after left foot snakebite 10 d prior without intermittent claudication or atrial fibrillation history.He was diagnosed with acute right lower extremity arterial thrombosis,which may have been caused by coagulopathy after snakebite and lower extremity atherosclerotic occlusive disease.Lower extremity computed tomography angiography at another hospital revealed that the aortoiliac and femoral arteries had neither filling defects nor atherosclerosis,but the right popliteal artery was occluded 2.3 cm below the tibial plateau.The patient received emergency catheter-directed thrombolysis,but amputation was carried out 11 d after admission because the patient had been admitted to the hospital too late to save the extremity.CONCLUSION Acute ischaemia of the lower extremity due to snakebite is a rare event,and physicians should bear in mind the serious complications that may occur,especially in patients with atherosclerotic disease.

阿是穴针刺放血治疗蛇伤局部肿痛临床疗效观察

Objective:To evaluate the clinical therapeutic effect of acupuncture bloodletting therapy on local swelling and pain of snakebite in the patients bitten by snakes.Methods:A total of 106 patients with trimeresurus stejnegeri bite were randomly divided into two groups,a conventional treatment group and a conventional treatment combined with bloodletting therapy group,53 cases in each one.In the conventional treatment group,the convention treatment of western medicine was adopted.In the conventional treatment combined with bloodletting therapy group,on the base of the conventional treatment,bloodletting therapy was applied at Ashi points selected at the tender points around the wound.The intervention and observation were performed not less than 7 days in two groups.Before and after treatment,swelling and pain degrees were measured and remission time of both the limb swelling and pain were recorded in the patients.Results:Compared with the values on day 1 of treatment,swelling degree and visual analogue scale(VAS) score of the upper and lower limbs were all lower on day 3 and day 7 of treatment in the patients of the two groups(all P <0.05).Compared with the conventional treatment group,swelling degree and VAS score of the upper and lower limbs were all lower in the values of the conventional treatment combined with bloodletting therapy group on day 3 and day 7 of treatment respectively(all P <0.05).The remission time of either limb swelling or pain in the patients of the conventional treatment combined with bloodletting therapy group was shorter than the conventional treatment group respectively(both P <0.05).Conclusion:Acupuncture bloodletting therapy can effectively relieve the local swelling and pain caused by snakebite,promote the recovery of limb function,shorten the treatment course and improve the clinical therapeutic effect.

Increased Efficacy of Antivenom Combined with Hyperbaric Oxygen on Deinagkistrodon acutus Envenomation in Adult Rats

Background：Snakebites are a neglected threat to global human health with a high morbidity rate.The present study explored the efficacy of antivenom with hyperbaric oxygen （HBO） intervention on snakebites,which could provide the experimental basis for clinical adjuvant therapy.Methods：Male Sprague-Dawley rats （n =96） were randomized into four groups：the poison model was established by injecting Deinagkistrodon acutus （D.acutus） venom （0.8 LD50） via the caudal vein;the antivenom group was injected immediately with specific antivenom via the caudal vein after successful establishment of the envenomation model;and the antivenom ＋ HBO group was exposed to HBO environment for 1 h once at predetermined periods of 0 h,4 h,12 h,and 23 h after antivenin administration.Each HBO time point had six rats;the control group was left untreated.The rats in the experimental group were euthanized at the corresponding time points after HBO therapy,and brain tissue and blood were harvested immediately.Hematoxylin and eosin （H＆E） staining was used to investigate the pathological changes in the rat brain.Immunohistochemistry （IHC）,real-time polymerase chain reaction （PCR）,and Western blotting were used to detect the expression ofNestin mRNA and protein in the subventricular zone （SVZ） of the brain.The levels of coagulation function （prothrombin time,activated partial thromboplastin time [APTT],and fibrinogen） and oxidation/antioxidation index （malondialdehyde [MDA] and superoxide dismutase [SOD]） were analyzed.Data were analyzed using one-way analysis of variance.Results：The brain tissue from rats in the poison model was observed for pathological changes using H＆E staining.Tissues showed edema,decreased cell number,and disordered arrangement in the SVZ in the snake venom group.The antivenom-HBO intervention significantly alleviated these observations and was more prominent in the antivenom ＋ HBO group.The serum levels of SOD and MDA in the snake venom group were increased and the antivenom-HBO intervention further increased the SOD levels but significantly decreased the MDA levels;however,this was enhanced within 1 h after HBO administration （MDA：F=5.540,P=0.008,SOD：F=7.361,P =0.000）.Activated partial thromboplastin time （APTT） was significantly abnormal after venom administration but improved after antivenom and was even more significant in the antivenom ＋ HBO group 5 h after envenomation （F =25.430,P =0.000）.Only a few nestin-positive cells were observed in the envenomation model.The expression levels were significant in the antivenom and antivenom ＋ HBO groups within 1 and 5 h after envenomation and were more significant in the antivenom ＋ HBO group as determined by IHC,real-time PCR,and Western blotting （P 〈 0.05）.D.acutus envenomation has neurotoxic effects in the brain of rats.Conclusions：Antivenin and HBO,respectively,induced a neuroprotective effect after D.acutus envenomation by attenuating brain edema,upregulating nestin expression in SVZ,and improving coagulopathy and oxidative stress.The intervention efficacy of antivenom with HBO was maximum within 5 h after envenomation and was more efficacious than antivenom alone.

Neutralising effects of small molecule toxin inhibitors on nanofractionated coagulopathic Crotalinae snake venoms

Repurposing small molecule drugs and drug candidates is considered as a promising approach to revolutionise the treatment of snakebite envenoming.In this study,we investigated the inhibiting effects of the small molecules varespladib(nonspecific phospholipase A2 inhibitor),marimastat(broad spectrum matrix metalloprotease inhibitor)and dimercaprol(metal ion chelator)against coagulopathic toxins found in Crotalinae(pit vipers)snake venoms.Venoms from Bothrops asper,Bothrops jararaca,Calloselasma rhodostoma and Deinagkistrodon acutus were separated by liquid chromatography,followed by nanofractionation and mass spectrometry identification undertaken in parallel.Nanofractions of the venom toxins were then subjected to a high-throughput coagulation assay in the presence of different concentrations of the small molecules under study.Anticoagulant venom toxins were mostly identified as phospholipases A2,while procoagulant venom activities were mainly associated with snake venom metalloproteinases and snake venom serine proteases.Varespladib was found to effectively inhibit most anticoagulant venom effects,and also showed some inhibition against procoagulant toxins.Contrastingly,marimastat and dimercaprol were both effective inhibitors of procoagulant venom activities but showed little inhibitory capability against anticoagulant toxins.The information obtained from this study aids our understanding of the mechanisms of action of toxin inhibitor drug candidates,and highlights their potential as future snakebite treatments.

A ten-year retrospective review of 1 107 snakebite patients in Sanya,China

Sanya is the one of most southern cities and tropical cities in China,situated on Hainan Island.It located between 18°09′ and 18°37′ latitude almost the same geographic position as Hawaii.Because of Sanya＇s location,it is a suitable habitat for snake to reproduce as other tropical areas.