Background: Ophidian envenomation is common in Sub-Saharan Africa, and its management is hampered by the lack of access to healthcare services in rural areas, in particular the availability and appropriate use of anti...Background: Ophidian envenomation is common in Sub-Saharan Africa, and its management is hampered by the lack of access to healthcare services in rural areas, in particular the availability and appropriate use of antivenom. Rare cases of serious side effects following the administration of antivenom have been reported. This is the case for a young farmer from the central region of Togo, who experienced a second snake bite within four years, and in whom antivenom serotherapy led to severe allergic manifestations. Case presentation: This 24-year-old patient, with a history of antivenom and tetanus serotherapy, was admitted to the Centre Hospitalier Régional (CHR) of Sokodé for a snakebite that occurred 45 minutes earlier while working in the field. Clinical assessment on admission revealed grade 1 envenomation, characterized by local pain in the right upper limb, with no sign of complication. He received an intravenous infusion of antivenom serotherapy, which rapidly relieved the pain, allowing him to be discharged after 24 hours of hospital monitoring. However, he was readmitted five days later for a skin rash associated with generalized pruritus and edema of the face and the neck, which prompted his evacuation to the Sylvanus Olympio University Hospital. He was diagnosed with a hypersensitivity-type allergic reaction to antivenom serum. Symptomatic treatment with antihistamines resulted in a favourable outcome after five days in the hospital. Conclusion: This young farmer developed a severe allergic reaction following a second course of antivenom serotherapy for low-grade ophidian envenomation. Although the efficacy of antivenom serum is undeniable in the management of snakebites, its use should be guided by a sound clinical assessment and framed by rigorous monitoring, especially in people sensitized to antivenom or antitoxin serotherapy. This highlights the importance of training healthcare staff alongside the availability of anti-venomous sera at peripheral healthcare centres.展开更多
Background: About 50 species of scorpions cause fatal scorpionism worldwide.Most of these are members of the Buthidae family, and include, among others,Mesobuthus eupeus, Androctonus crassicauda, Leiurus abdullahbayra...Background: About 50 species of scorpions cause fatal scorpionism worldwide.Most of these are members of the Buthidae family, and include, among others,Mesobuthus eupeus, Androctonus crassicauda, Leiurus abdullahbayrami, Leiurus quinquestriatus, Tityus pachyurus and Androctonus australis. Because high doses of scorpion venom and antivenom can cause death and hypersensitive reactions, there is a need to develop a formula that can be used to calculate both lethal and effective doses for scorpion venom and antivenom, respectively, thereby obviating the need for laboratory experiments.Methods: In view of this, a literature search was carried out with the aim of modifying the formula(LD_(50)=ED_(50)/3× W_a × 10^(-4))for calculation of the median lethal dose(LD_(50)) of scorpion venom and the ED_(50) of antivenom. The human equivalent dose(HED) formula was assessed for extrapolation of LD_(50) and ED_(50) from animals to human for comparison and relevance with the new formula.Results: The findings showed that the newly developed formula(LD_(50)= ED_(50)^(1/3)×W_a× 10^(-4)) yielded results that are very close to the reported values. Therefore, the newly developed and HED formulas can be used for calculation of LD_(50) and ED_(50) values for scorpion venom and antivenom, respectively.Conclusion: The new formula yielded better results than the HED formula, confirming its predictive validity, precision, and reliability, thereby obviating the need for rigorous experiments and justifying the principles of reduction, refinement, and replacement(3 Rs).展开更多
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 coul...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.展开更多
目的:对比分析蛇咬伤救治体系建立前后的毒蛇咬伤救治效果,为蛇咬伤患者临床救治提供参考。方法:本研究纳入2019年4月—2020年10月宜昌市中心人民医院救治的334例中重度蛇咬伤患者,根据是否建立蛇咬伤救治体系,分为对照组138例,观察组19...目的:对比分析蛇咬伤救治体系建立前后的毒蛇咬伤救治效果,为蛇咬伤患者临床救治提供参考。方法:本研究纳入2019年4月—2020年10月宜昌市中心人民医院救治的334例中重度蛇咬伤患者,根据是否建立蛇咬伤救治体系,分为对照组138例,观察组196例。对比分析两组患者的就诊时间、诊断时间、抗蛇毒血清使用时间、住院时间、医疗费用及相关治疗效果。结果:与对照组相比,观察组患者的就诊时间(3.12±1.21 h vs 5.32±1.70 h)、诊断时间(29.45±7.37 min vs 44.47±10.19 min)、抗蛇毒血清使用时间(6.65±2.69 min vs 12.94±5.64 min)、住院时间(2.25±1.17天vs 4.72±2.00天)明显缩短(均P<0.001),并且医疗费用(2845.77±580.48元vs 4962.18±918.92元,P<0.001)明显降低,皮肤肿胀行切排减压(15.82%vs 30.43%,P<0.05)的发生率明显减少,患者的治愈率由83.33%提高到94.90%。结论:蛇咬伤救治体系的建立实现了降本增效,提高了毒蛇咬伤的治愈率,值得在临床推广运用。展开更多
Objective: To explore whether a DNA immunization approach targeting the major haemorrhage molecule of a prothrombin activator-like metalloproteinase from Echis ocellatus(E. ocellatus) venom could be conceived to inspi...Objective: To explore whether a DNA immunization approach targeting the major haemorrhage molecule of a prothrombin activator-like metalloproteinase from Echis ocellatus(E. ocellatus) venom could be conceived to inspire antibodies with more prominent specificity and equal adequacy to current conventional antivenoms systems.Methods: The isolated DNA Eo MP-6 was used as the template for PCR amplification using the Eo DC-2-specific forward and reverse primers. A PCR product of approximately700 bp was obtained and cloned into p Sec Tag-B expression vector where anti-Eo DC-2antibodies were generated and analysed for their efficacy to neutralise local haemorrhage in vitro and in vivo.Results: Our results suggest that the generated anti-Eo DC-2 showed a remarkable efficacy by(a) interfering with the interaction of the recombinant disintegrin "Eo DC-2" isolated from the E. ocellatus as well as other viper species to the a2b1-integrins on platelets;(b) complete inhibition of the catalytic site of the metalloproteinase molecules in vitro using an adaptation antibody zymography assay. Furthermore, it has a polyspecific potential and constitutively expressed significant inhibition by cross-reaction and neutralised venom-induced local haemorrhage exerted by different viper species in vivo. The potential characteristic of Eo DC-2 against one part(the non-catalytic domain) as opposed to the whole molecule to neutralise its haemorrhagic activity is of crucial importance as it represents a novel approach with greater immunological specificity and fewer hazards, if any, than conventional systems of antivenom production, by exposure large animals that usually being used for the current antivenom production to a less injurious than expression of the whole molecule containing the catalytic metalloprotease domain. Hence, we report for the first time that our preliminary results hold a promising future for antivenom development.Conclusions: Antibodies generated against the E. ocellatus venom prothrombin activatorlike metalloprotease and disintegrin-cysteine-rich domains modulated and inhibited the catalytic activity both in vitro and in vivo of venom metalloproteinase disintegrin cysteine rich molecules. Thus, generating of venom specific-toxin antibodies by DNA immunization offer a more rational treatment of snake envenoming than conventional antivenom.展开更多
文摘Background: Ophidian envenomation is common in Sub-Saharan Africa, and its management is hampered by the lack of access to healthcare services in rural areas, in particular the availability and appropriate use of antivenom. Rare cases of serious side effects following the administration of antivenom have been reported. This is the case for a young farmer from the central region of Togo, who experienced a second snake bite within four years, and in whom antivenom serotherapy led to severe allergic manifestations. Case presentation: This 24-year-old patient, with a history of antivenom and tetanus serotherapy, was admitted to the Centre Hospitalier Régional (CHR) of Sokodé for a snakebite that occurred 45 minutes earlier while working in the field. Clinical assessment on admission revealed grade 1 envenomation, characterized by local pain in the right upper limb, with no sign of complication. He received an intravenous infusion of antivenom serotherapy, which rapidly relieved the pain, allowing him to be discharged after 24 hours of hospital monitoring. However, he was readmitted five days later for a skin rash associated with generalized pruritus and edema of the face and the neck, which prompted his evacuation to the Sylvanus Olympio University Hospital. He was diagnosed with a hypersensitivity-type allergic reaction to antivenom serum. Symptomatic treatment with antihistamines resulted in a favourable outcome after five days in the hospital. Conclusion: This young farmer developed a severe allergic reaction following a second course of antivenom serotherapy for low-grade ophidian envenomation. Although the efficacy of antivenom serum is undeniable in the management of snakebites, its use should be guided by a sound clinical assessment and framed by rigorous monitoring, especially in people sensitized to antivenom or antitoxin serotherapy. This highlights the importance of training healthcare staff alongside the availability of anti-venomous sera at peripheral healthcare centres.
文摘Background: About 50 species of scorpions cause fatal scorpionism worldwide.Most of these are members of the Buthidae family, and include, among others,Mesobuthus eupeus, Androctonus crassicauda, Leiurus abdullahbayrami, Leiurus quinquestriatus, Tityus pachyurus and Androctonus australis. Because high doses of scorpion venom and antivenom can cause death and hypersensitive reactions, there is a need to develop a formula that can be used to calculate both lethal and effective doses for scorpion venom and antivenom, respectively, thereby obviating the need for laboratory experiments.Methods: In view of this, a literature search was carried out with the aim of modifying the formula(LD_(50)=ED_(50)/3× W_a × 10^(-4))for calculation of the median lethal dose(LD_(50)) of scorpion venom and the ED_(50) of antivenom. The human equivalent dose(HED) formula was assessed for extrapolation of LD_(50) and ED_(50) from animals to human for comparison and relevance with the new formula.Results: The findings showed that the newly developed formula(LD_(50)= ED_(50)^(1/3)×W_a× 10^(-4)) yielded results that are very close to the reported values. Therefore, the newly developed and HED formulas can be used for calculation of LD_(50) and ED_(50) values for scorpion venom and antivenom, respectively.Conclusion: The new formula yielded better results than the HED formula, confirming its predictive validity, precision, and reliability, thereby obviating the need for rigorous experiments and justifying the principles of reduction, refinement, and replacement(3 Rs).
基金This study was supported by grants from the Science and Technology Foundation of Guizhou Province （No. SY [2013]3067） and National Natural Science Foundation of China （No. 81560217）.
文摘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.
文摘目的:对比分析蛇咬伤救治体系建立前后的毒蛇咬伤救治效果,为蛇咬伤患者临床救治提供参考。方法:本研究纳入2019年4月—2020年10月宜昌市中心人民医院救治的334例中重度蛇咬伤患者,根据是否建立蛇咬伤救治体系,分为对照组138例,观察组196例。对比分析两组患者的就诊时间、诊断时间、抗蛇毒血清使用时间、住院时间、医疗费用及相关治疗效果。结果:与对照组相比,观察组患者的就诊时间(3.12±1.21 h vs 5.32±1.70 h)、诊断时间(29.45±7.37 min vs 44.47±10.19 min)、抗蛇毒血清使用时间(6.65±2.69 min vs 12.94±5.64 min)、住院时间(2.25±1.17天vs 4.72±2.00天)明显缩短(均P<0.001),并且医疗费用(2845.77±580.48元vs 4962.18±918.92元,P<0.001)明显降低,皮肤肿胀行切排减压(15.82%vs 30.43%,P<0.05)的发生率明显减少,患者的治愈率由83.33%提高到94.90%。结论:蛇咬伤救治体系的建立实现了降本增效,提高了毒蛇咬伤的治愈率,值得在临床推广运用。
基金Supported by the Wellcome Trust,UK(RAH,Grant No.061325)the University of Science and Technology,Yementhe Gunter Trust,UK
文摘Objective: To explore whether a DNA immunization approach targeting the major haemorrhage molecule of a prothrombin activator-like metalloproteinase from Echis ocellatus(E. ocellatus) venom could be conceived to inspire antibodies with more prominent specificity and equal adequacy to current conventional antivenoms systems.Methods: The isolated DNA Eo MP-6 was used as the template for PCR amplification using the Eo DC-2-specific forward and reverse primers. A PCR product of approximately700 bp was obtained and cloned into p Sec Tag-B expression vector where anti-Eo DC-2antibodies were generated and analysed for their efficacy to neutralise local haemorrhage in vitro and in vivo.Results: Our results suggest that the generated anti-Eo DC-2 showed a remarkable efficacy by(a) interfering with the interaction of the recombinant disintegrin "Eo DC-2" isolated from the E. ocellatus as well as other viper species to the a2b1-integrins on platelets;(b) complete inhibition of the catalytic site of the metalloproteinase molecules in vitro using an adaptation antibody zymography assay. Furthermore, it has a polyspecific potential and constitutively expressed significant inhibition by cross-reaction and neutralised venom-induced local haemorrhage exerted by different viper species in vivo. The potential characteristic of Eo DC-2 against one part(the non-catalytic domain) as opposed to the whole molecule to neutralise its haemorrhagic activity is of crucial importance as it represents a novel approach with greater immunological specificity and fewer hazards, if any, than conventional systems of antivenom production, by exposure large animals that usually being used for the current antivenom production to a less injurious than expression of the whole molecule containing the catalytic metalloprotease domain. Hence, we report for the first time that our preliminary results hold a promising future for antivenom development.Conclusions: Antibodies generated against the E. ocellatus venom prothrombin activatorlike metalloprotease and disintegrin-cysteine-rich domains modulated and inhibited the catalytic activity both in vitro and in vivo of venom metalloproteinase disintegrin cysteine rich molecules. Thus, generating of venom specific-toxin antibodies by DNA immunization offer a more rational treatment of snake envenoming than conventional antivenom.
