Agkistrodon Acutus Research Articles

Inactivation of Venom PLA₂ Alleviates Myonecrosis and Facilitates Muscle Regeneration in Envenomed Mice: A Time Course Observation.

Snake venom is a complex cocktail of toxins which induces a series of clinical and pathophysiological manifestations in victims, including severe local tissue damage and systemic alterations. Deinagkistrodon acutus (D. acutus) ranks among the “big four” life-threatening venomous species in China, whose venom possesses strong myotoxicity and hematotoxicity that often lead to permanent disability or muscle atrophy. Varespladib, an inhibitor of mammalian phospholipase A2 (PLA2), has been recently reproposed as an effective antidote against snakebite envenomation. The present study aimed at evaluating the protective role of varespladib on muscle regeneration in envenomed mice. Mice were grouped and subjected to inoculation with D. acutus venom or a mixture of venom and varespladib or control vehicle in the gastrocnemius muscle. Local injuries including hemorrhage, myonecrosis, ulceration, and systemic damages including general dysfunction, visceral failure, and inflammatory responses were observed at 1, 3, 7, 14, and 21 days. The results indicated that most of the muscle myonecrosis and hemorrhage were alleviated by varespladib. Besides, the pretreated mice recovered rapidly with lesser atrophy and muscle fibrosis. In conclusion, the findings of the present study suggested that varespladib is an effective antidote that could neutralize D. acutus venom and allow for earlier and improved rehabilitation outcome.

Anti-Deinagkistrodon acutus venom properties of ethanolic root extract from Cynanchum paniculatum (Bunge) kitag and its GC-MS analysis

Ethnopharmacological relevanceCynanchum paniculatum (Bunge) Kitag known as a popular Chinese herbal medicine has been used for a long time to treat a wide variety of diseases including snakebites. However, there is scarce information on the antiophidian potential of this plant. Aim of the studyThe purpose of this work was to evaluate the inhibition effects of the ethanol extract of C. paniculatum on the enzymatic and biological activities induced by Deinagkistrodon acutus venom (DAV). The phytochemical components in the extract were also determined for understanding the mechanism of antivenom activities. Materials and methodsFresh root of C. paniculatum was shed-dried and smashed into powder. The powder was then extracted in 75% ethanol by refluxing method. Inhibition of proteolytic, phospholipase A2, fibrinogenolytic and hyaluronidase activities of DAV by the extract were determined in vitro. Neutralization of lethal, hemorrhagic, myotoxic and edematogenic activities induced by the venom were also performed in vivo. Phytochemical constituents of the extract were analyzed by gas chromatography–mass spectrometry (GC-MS). ResultsThe ethanolic root extract of C. paniculatum (CPER) was able to completely (100%) inhibit protease and hyaluronidase activities induced by DAV when preincubated at a ratio of 1:100 and 1:50 (venom/extract, W/W), respectively. PLA2 and fibrinogenolytic enzyme activities were actually neutralized at the concentration tested. In-vivo studies the inhibition of venom hemorrhagic and myotoxic action reached 100% when the venom was previously incubated with the extract (1:100) before injection. The edematogenic effect was also inhibited in a dose-response manner. CPER completely inhibited DAV-induced lethality in mice when the venom was preincubated with the extract at a ratio of 1:100. GC-MS analysis indicated that a total of 58 compounds were discovered in CPER. Among them, 5 bioactive constituents including 9,12-octadecadienoic acid (Z,Z)-, n-hexadecanoic acid, cis-vaccenic acid, γ-sitosterol and stigmasterol exhibit antivenom activity according to previous reports. ConclusionsThe results obtained in this work validate for the first time CPER as a traditional antiophidic herb, especially inhibitory effect on local damage induced by DAV, suggesting it could be used as a potential source of bioactive components against snakebites.

Proteomic characterization of six Taiwanese snake venoms: Identification of species-specific proteins and development of a SISCAPA-MRM assay for cobra venom factors

Deinagkistrodon acutus, Trimeresurus stejnegeri, Protobothrops mucrosquamatus, Daboia russelii siamensis, Bungarus multicinctus and Naja atra are the six medically important venomous snake species in Taiwan. In this study, we characterized and compared their venom protein profiles using proteomic approaches. The major snake venom proteins were identified by GeLC-MS/MS and the total venom proteome was characterized by in-solution digestion coupled with LC-MS/MS. A total of 27–52 proteins, categorized into 23 protein families, were identified in each snake's venom. The major venom components found in Viperidae species (D. acutus, T. stejnegeri, P. mucrosquamatus and D. russelii) were C-type lectin, snake venom serine proteinase, venom metalloproteinase and phospholipase A2, whereas three-finger toxin and phospholipase A2 were the major components detected in the venom of Elapidae snakes (B. multicinctus and N. atra). This study also provided the first demonstration of some low-abundance proteins in these six snake venoms, including 5′-nucleotidase, glutaminyl-peptide cyclotransferase and phosphodiesterase, among others. Furthermore, we found that cobra venom factor (CVF) is a cobra-specific protein. We produced anti-peptide antibodies against CVF and used it to develop a highly sensitive SISCAPA-MRM assay for quantifying CVF. The limit of detection and lower limit of quantification were 3.2 and 9.6 attomoles, respectively. This assay was used to precisely quantify CVF in 1 μg crude venom proteins from three Naja species and king cobra. The amount of CVF varied from 0.9 to 54.36 femtomoles (equivalent to 0.16–10.03 mg/g of venom protein). Biological significanceThere are six medically significant venomous snakes in Taiwan. The venoms of the four Viperidae species (Deinagkistrodon acutus, Trimeresurus stejnegeri, Protobothrops mucrosquamatus and Daboia russelii siamensis) cause local tissue swelling; this symptom is also seen in N. atra envenomation in humans, potentially complicating the differential diagnosis of envenomation by N. atra and Viperidae species. Thus, characterization of the venom proteomes of the six Taiwanese snakes, including the relative abundance of the major components and species-specific protein(s) in each venom type, could be useful for future venom research, including the development of new assay(s) for detecting snake species-specific venom protein(s) and new type(s) of antivenom.

MOLECULAR DOCKING STUDIES OF SNAKE VENOM SERINE PROTEASE OF SHARP-NOSED PIT VIPER WITH HESPERETIN

Objective: The management of snake bite envenomation is a global challenge affecting millions of people. Immunotherapy is still regarded as the treatment of choice; however, their subsequent adverse effects restrict their potential use for therapy against snake venom poisoning. In recent years, more attention has been given to the exploration of indigenous medicinal plants for their outstanding benefits for the treatment of several diseases and disorders, including snake venom poisoning. Hesperetin is a naturally occurring compound derived from a flavanone glycoside, hesperidin and is obtained from various citrus fruits. It is known to possess significant inhibitory activity against snake venom serine proteases. The aim of our present study was to investigate the significant inhibitory action of hesperetin on thrombin-like serine protease from sharp-nosed pit viper (Deinagkistrodon acutus) snake venom.Methods: We have employed molecular docking analysis by implementing the state-of-the-art docking program to validate the hypothesis of the prospective inhibitory properties of hesperetin on thrombin-like serine proteases of snake venom. AutoDock 4.2, InterProSurf, MGLTools, and MTiAutoDock were utilized for the molecular docking analysis of thrombin-like serine protease obtained from the snake venom of sharp-nosed pit viper with the natural compound hesperetin.Results: The results generated from in silico based approach reveals the significant inhibitory role of hesperetin against thrombin-like snake venom proteases, which might lead to the drug designing of the inhibitors of snake venom serine proteases.Conclusion: The implementation of molecular docking analysis by the employment of state-of-the-art docking program supports the potential of inhibitory activity of naturally obtained hesperetin compound on thrombin-like serine proteases of snake venom. The generated in silico results suggests that the novel structure hesperetin - flavanone might act as a potent inhibitor of thrombin-like snake venom proteases, and unlocks the possibilities for designing drugs of the inhibitors of snake venom serine proteases. Moreover, the investigation of the novel compound obtained from natural sources for their inhibitory activity against snake venom serine proteases would lead to the discovery of newer inhibitory compound from a highly uninvestigated research arena.

Effects of hemocoagulase agkistrodon on the coagulation factors and its procoagulant activities.

ObjectiveHemocoagulase agkistrodon (HCA), a thrombin-like enzyme (TLE) from the venom of the Chinese moccasin snake (Deinagkistrodon acutus), has been used in clinical practice as a hemostatic compound. The aim of this study was to further investigate the pharmacological properties of HCA.Materials and methodsSodium dodecyl sulfate or native polyacrylamide gel electrophoresis (SDS- or N-PAGE) as well as enzyme linked immunosorbent assays (ELISAs) were conducted to study the effects of HCA on the human plasma fibrinogen and prothrombin levels, as well as its in vitro interactions with some coagulation factors. In addition, the bleeding time effects of HCA in the mouse tail-bleeding model as well as its effects on the fibrinogen levels in rabbits were determined in vivo.ResultsIn vitro results revealed that HCA exerts its procoagulant activities by hydrolyzing fibrinogen into segments that are easier to be absorbed, reducing the risk of thrombus formation. Besides, HCA could significantly inhibit the activation of prothrombin at the concentration of 0.3 μM. Unexpectedly, we also found that HCA was able to strongly bind to factor X/Xa (in a ratio of 1:1) and thus inhibit the acceleration of active factor X to tissue plasminogen activator-catalyzed plasminogen activation, demonstrating that it could be less likely to lead to thrombus formation. Finally, in vivo results indicated that HCA could significantly shorten the bleeding time in the mouse tail-bleeding model and had no effect on the fibrinogen levels in rabbits.ConclusionIn summary, HCA, a unique and new family member of TLEs, may become a new clinical drug for the prevention and treatment of hemorrhage due to its unique and complex interactions with the blood system. Clarification of these features will enable us to further understand the mechanism of action of HCA and then promote its further application in clinical practice as a therapeutic drug.

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 of Nestin 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.

Research progress of the clinical hemostatic effect of heamocoagulase agkistrodon

Haemocoagulase agkistrodon for injection is a kind of protein hemostatic which is purified from snake venom of Agkistrodon acutus, the hemostatic mechanism of the drug is it that the removal of fibrinogen from fibrinogen in blood can make it into monomeric fibrin after entering the body and enhance coagulation function.Preclinical results showed that the drug can significantly shortened the time of tail bleeding in mice and coagulation time of whole blood in rabbits.Clinical studies show that the medicine has a safe and effective hemostatic effect on incision in abdominal, thyroid, department of obstetrics and gynecology, department of urology, and the hemostatic effect of thoracic incision is not obvious.In this review, the research progress on the efficacy and safety of Agkistrodon acutus thrombin in clinical hemostasis were reviewed. Key words: Snake venoms; Thrombin; Hemostasis; Review

Ulnar artery pseudoaneurysm and compartment syndrome formation after snake bite to the left forearm

Objective: To report the outcome of a patient who developed pseudoaneurysms and compartment syndrome after a Deinagkistrodon acutus snakebite.Case report: A 61-year-old man, bitten by Deinagkistrodon acutus in his left forearm, came to the hospital eight hours after the bite. Despite the use of antivenom and supportive therapy, the patient developed compartment syndrome of the left forearm, the tissue pressure was elevated and fasciotomy was arranged. During the initial surgery, part of the necrotic tissues was removed. Moreover, two pseudoaneurysms of the ulnar artery were identified at the second debridement and the pseudoaneurysms were removed during this surgery. The patient went through a total of four surgeries, recovered and was eventually discharged from the hospital.Conclusion: A snake bite by Deinagkistrodon acutus may be accompanied by pseudoaneurysms and increased intracompartmental pressure.

Cloning, expression, purification and bioactivity evaluation of a thrombin-like enzyme from Deinagkistrodon acutus venom gland library.

To identify a new member of serine proteases from Deinagkistrodon acutus via phage display technique and appraise its biocatalytic activities. A novel thrombin-like enzyme gene was cloned by screening the phage display library of D. acutus venom gland. The gene has a 783bp ORF encoding 260 amino acids. A recombinant enzyme expression vector was constructed and the fused protein was expressed in Escherichia coli. The protein was purified showing a single band of approx. 49.4kDa after SDS-PAGE. The recombinant enzyme was capable of congealing normal human plasma in vitro with the minimum coagulant dose of 6µg in 57s. It exhibited fibrinogenolytic activity by hydrolyzing the Aα-chain of human fibrinogen. It was most active at pH 7.5-8.0 and 35-40°C with the highest clotting activity of 120 NIH units/mg. It was completely inhibited by PMSF but not by EDTA. Multiple sequence alignments demonstrate that this protein shares high identity with other thrombin-like enzymes from snake venoms. A novel thrombin-like protein from D. acutus venom was identified, expressed and biologically characterized in vitro. Its fibrinogenolytic properties make the enzyme applicable for biochemical research and drug development on thrombolytic therapy.

Investigation of the inhibitory potential of phospholipase A2 inhibitor gamma from Sinonatrix annularis to snake envenomation

SaPLIγ is a novel gamma phospholipase A2 inhibitor (PLI) recently isolated from Sinonatrix annularis, a Chinese endemic non-venomous snake. To explore the neutralization effects of saPLIγ in snakebite envenomation, a dose equivalent to LD50 of Deinagkistrodon acutus, Agkistrodon halys and Naja atra venom with/without saPLIγ was inoculated into the gastrocnemius muscle of female Kunming mice. The ability of saPLIγ to inhibit myonecrosis and systemic toxicity were evaluated through investigations of muscle histopathology, and determination of the serum levels of creatine kinase (CK), lactate dehydrogenase isoenzyme1 (LDH1) and aspartate transferase (AST). Edema of the gastrocnemius muscle was evaluated by calculating the width difference between the inoculated limb and the contralateral leg. Desmin loss in the gastrocnemius muscle was determined by Western blot analysis. Co-immunoprecipitation and shotgun LC-MS/MS analyses were performed to identify venom proteins that interact with saPLIγ. All the envenomed mice had significantly elevated serum CK, LDH1 and AST levels, whereas the levels were decreased significantly in the presence of saPLIγ. Histopathological evaluation of gastrocnemius muscle sections showed severe snake venom-induced damage, characterized by leukocyte infiltration and erythrocyte leakage, leading to local edema. Myonecrosis, hemorrhage and desmin loss were significantly attenuated by saPLIγ. SaPLIγ interacted with a wide range of venom proteins, including PLA2s, metalloproteinases and C type lectins, which may contribute to broad anti-venom effects.

Dacin, one metalloproteinase from Deinagkistrodon acutus venom inhibiting contraction of mouse ileum muscle

BackgroundMice were bitten by five-pace vipers (Deinagkistrodon acutus), and then envenomed. It was well-known that the snake venom mainly disturbed the blood homeostasis of the envenomed victims. Ocassionally, we found that the venom of D. acutus could inhibit the contraction tension of mouse ileum, so in this study we aimed to identify the active component inhibiting the contraction tension of mouse ileum in the snake venom.ResultsThe active component inhibiting the contraction tension of mouse ileum, designated as Dacin, was isolated from D. acutus venom, purified to protein homogeneity and composed of a single peptide chain, about 23 kDa analyzed by SDS-PAGE, and 22, 947. 9 Da measured by MALDI-TOF-MS. Not only the results of its PMF blasted by Mascot indicated that Dacin may be one snake venom metalloproteinase (SVMP), but also the results of the biochemical and in-vivo assays as follow demonstrated that it was one SVMP: it cleaved Aα and Bβ chains, not Cγ of bovine fibrinogen within 1 h, and also hydrolyzed fibrin polymer; besides its fibrino(geno)lytic activities were strongly inhibited by β- mercaptoethanol, EDTA and EGTA; and it could induce a hemorrhagic reaction under the dorsal skin of mouse. In the isolated tissue assays, Dacin caused the concentration-dependent and time-dependent inhibitory actions on the spontaneous contraction tension of the ileum smooth muscle of mouse, and the inhibitory effects were irreversible.ConclusionsTaken together, for the first time one active component (Dacin, a SVMP) that irreversibly inhibited the spontaneous contraction tension of mouse ileum has been isolated and identified from D. acutus venom. The findings may provide not only a new insight for toxicological researches on SVMPs and venoms of the vipers, but also a reference for clinicians to treat the snake-bitten victims. However, Dacin’s inhibitory molecular mechanism will be further studied in the future.

Preparation and neutralization efficacy of IgY antibodies raised against Deinagkistrodon acutus venom

BackgroundThe five-paced pit viper (Deinagkistrodon acutus), endemic to China and northern Vietnam, is responsible for most snakebites in the Chinese territory. Antivenom produced from horses is the main treatment for snakebites, but it may cause numerous clinical side effects and have other disadvantages involved in their production such as the welfare of animals. The present study was conducted aiming to develop an alternative antibody (IgY) from the egg yolk of leghorn chickens immunized with snake venom.MethodsIgY from the egg yolk of white leghorn chickens previously immunized intramuscularly with D. acutus venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot. Finally, IgY neutralization assays to test its efficacy against hemorrhagic, edema-forming and myotoxic activities of D. acutus venom were conducted on mice.ResultsFor the first time, IgY antibodies against D. acutus venom were raised successfully in egg yolk of chickens injected with D. acutus venom multiple times. By three steps, including caprylic acid extraction, ammonium sulfate precipitation and affinity chromatography, IgY antibodies were isolated and purified from egg yolk, which exhibited a single protein band on SDS-PAGE and two bands (about 65 kDa and 35 kDa, respectively) under reducing conditions, and presented a high titer (1:40,000) tested by ELISA. Immunoblot analysis confirmed that these IgY were polyclonal antibodies since they bound to components of D. acutus venom. Furthermore, immunodiffusion assay showed that anti-D. acutus venom IgY cross-reacted with the venoms of Trimeresurus albolabris and D. saxatilis Emelianov, but did not react to the venoms of Bungarus multicinctus and Naja atra. In the neutralizing lethal assay, the median effective dose of anti-D. acutus venom IgY was 14.14 mg/kg of mouse body weight under the challenge dose (3 LD50 of D. acutus venom). In neutralizing the hemorrhagic, edema-forming and myotoxic activities of D. acutus venom, IgY showed the characteristic dose-dependent neutralization effects against all these toxic activities of D. acutus venom.ConclusionAnti-D. acutus venom IgY antibodies with high purity and titer were for the first time raised successfully in egg yolk of chickens immunized with D. acutus venom. They were effective in neutralizing the lethal effects, and the hemorrhagic, edema-forming and myotoxic acitivities of D. acutus venom. IgY could be an effective source to develop a treatment against snake bites in humans or animals in the future.

Effect of Agkistrodon Acutus Venom PCA on HUVEC Activity

To investigate the effects of Agkistrodon acutus venom protein C activator(PCA) on ultrastructure of human umbilical vein endothelial cells(HUVEC), and the levels of tissue factor(TF), vascular von Willebrand factor (vWF) and endothelin-1 secreted by HUVEC and to clarify the anti-thrombotic mechanism of PCA. The experiments were divided into control group(DMEM), LPS group (LPS 0.1 µg/ml), PCA group(PCA 1 µg/ml) and PCA+LPS group (1 µg/ml PCA+ 0.1 µg/ml LPS). The morphology of endoplasmic reticulum, mitochondria and the number of autophagosome in HUVEC were observed by transmission electron microscopy. The TF, vWF and ET-1 were measured in the medium of each group by ELISA; RT-PCR was used to detect mRNA expression level of vWF and ET-1 in cells; and the protein expression level of TF in cells was detected by Western blot. Compared with the control group, the ultrastructural changes of HUVEC in the LPS group included the cell membrane getting rough, swelling of mitochondria and endoplasmic reticulum, and autophagosome increase, however, the ultrastructure differences between PCA and control group were not significant. Compared with the ultrastructure of HUVECs in LPS group, the swelling of mitochondria and endoplasmic reticulum disappeared in the LPS+PCA group, and the number of autophagosome decreased obviously. Compared with the control group, the content of ET-1, vWF and TF in cell culture supernatant, and the protein expression level of vWF, ET-1 gene and TF protein were significantly increased in LPS group (P<0.05); the expression levels of the 3 factors in the cell culture supernatant and cells in PCA group were not significantly different from the control group (P>0.05). The expression levels of TF, vWF and ET-1 in LPS group were significantly lower than those in LPS+PCA group (P<0.05). PCA(1 µg/ml) can reduce the ultrastructural changes of HUVEC induced by LPS, and inhibit the increase of TF, vWF and ET-1 secretion from HUVEC induced by LPS.

Study on the molecular mechanism of Chinese herbal medicine &amp;lt;italic&amp;gt;Cynanchum paniculatum&amp;lt;/italic&amp;gt; for treating snakebites

C. paniculatum is a traditional Chinese herb and widely used in the remedy of venomous snakebites; however, its efficacy of snakebite envenoming lacks enough experimental evidence, and its underlying molecular mechanism remains unknown. In this study, one bioactive component was screened and isolated from C. paniculatum by organic solvent extraction, column chromatography and HPLC in combination, and finally identified as paenonlide by MS and NMR techniques. The animal experiments and histological pathological sections showed that panenonlide remarkably inhibited hemorrhage, edema and muscle tissue necrosis induced by Deinagkistrodon acutus venom; meanwhile, it exhibited potent inhibitory effects on the fibrinogenolytic and PLA2 activities of D. acutus venom in in vitro tests. Furthermore, molecular simulation revealed that paenonlide interacted with the key components in D. acutus venom, including metalloproteinase and PLA2, ultimately preventing the injury induced by snakebites. Taken together, this study revealed the molecular mechanism of snakebites treatment by using a traditional Chinese herb ( C. Paniculatum ), and experimentally evidenced its critical role in snakebites treatment. This may also shed light on developing new drugs in clinics.

The impact of hemocoagulase for improvement of coagulation and reduction of bleeding in fracture-related hip hemiarthroplasty geriatric patients: A prospective, single-blinded, randomized, controlled study

BackgroundUncontrolled bleeding is associated with poor outcomes and mortality in geriatric patients undergoing hemiarthroplasty. Hemocoagulase agkistrodon is a hemocoagulative, anti-hemorrhagic enzyme complex from Deinagkistrodon acutus snake venom. This study aimed to investigate the efficacy of hemocoagulase agkistrodon on coagulation and bleeding outcomes in fracture-related hemiarthroplasty. Patients and methodsThis was a prospective, single-blinded, randomized controlled trial carried out between October 2013 and September 2014 in 96 geriatric patients undergoing hemiarthroplasty for unilateral femoral neck fracture. Patients were administrated hemocoagulase agkistrodon (n=48) or normal saline (n=48). Intraoperative blood loss, transfusion volume and rate, and drainage were assessed. Hemoglobin (Hb) and coagulation parameters (prothrombin time [PT], thrombin time [TT], plasma fibrinogen [FIB], and activated partial thromboplastin time [aPTT]) were recorded preoperatively and 30min and 1, 3, and 5days after surgery. Complications were followed up for 4 weeks. ResultsCompared to controls, hemocoagulase patients exhibited lower intraoperative blood loss (P<0.01) and postoperative blood loss, total drainage, mean transfusion volume, and transfusion rates (all P<0.05), with lower aPTT at 30min (P<0.05). No significant differences in postoperative FIB were observed. Controls exhibited significantly higher PP and TT on day 1, and Hb on days 1, 3, and 5 (P<0.05). No serious complications were reported. ConclusionsHemocoagulase reduced blood loss and transfusion in fracture-related hip hemiarthroplasty without increasing short-term adverse event rates. In geriatric populations, hemocoagulase could be used for limiting bleeding and related complications.Trial registration: This trial is registered in the Chinese Clinical Trial Register (no. ChiCTR-TRC-14004379)

Evolutionary trajectories of snake genes and genomes revealed by comparative analyses of five-pacer viper.

Snakes have numerous features distinctive from other tetrapods and a rich history of genome evolution that is still obscure. Here, we report the high-quality genome of the five-pacer viper, Deinagkistrodon acutus, and comparative analyses with other representative snake and lizard genomes. We map the evolutionary trajectories of transposable elements (TEs), developmental genes and sex chromosomes onto the snake phylogeny. TEs exhibit dynamic lineage-specific expansion, and many viper TEs show brain-specific gene expression along with their nearby genes. We detect signatures of adaptive evolution in olfactory, venom and thermal-sensing genes and also functional degeneration of genes associated with vision and hearing. Lineage-specific relaxation of functional constraints on respective Hox and Tbx limb-patterning genes supports fossil evidence for a successive loss of forelimbs then hindlimbs during snake evolution. Finally, we infer that the ZW sex chromosome pair had undergone at least three recombination suppression events in the ancestor of advanced snakes. These results altogether forge a framework for our deep understanding into snakes' history of molecular evolution.

Isolation and biochemical characterization of a gamma-type phospholipase A2 inhibitor from Macropisthodon rudis snake serum

A novel phospholipaseA2 (PLA2) inhibitory protein (PLI) was purified from the serum of Macropisthodon rudis, a non-venomous snake mainly found in southern China. The molecular mass of the purified PLI was 160 kDa as determined by Superdex 200HR; however, the PLI protein had only one subunit of 25.4 kDa as determined by 12% SDS-PAGE, indicating an oligomeric protein. PLI cDNA obtained by PCR from the liver of Macropisthodon rudis, revealed 549 bps coding for a mature protein of 183 amino acid residues. Based on an amino acid sequence alignment with venomous and non-venomous snakes, this inhibitor was determined to be in the γ type family of PLI. In vitro experiments showed that PLIγ inhibited enzymatic, inflammatory, and antibacterial activities of snake venom PLA2 isolated from Agkistrodon acutus.

Agkistrodon acutus-purified protein C activator protects human umbilical vein endothelial cells against H2O2-induced apoptosis

Context: Recent studies show that the Agkistrodon acutus (Viperidae) (syn. Deinagkistrodon acutus) protein C activator (PCA) treats acute myocardial infarction and ischaemia-reperfusion animal models effectively, while the underlying mechanism remains unknown.Objective: To study the effect of PCA on the injury of human umbilical vein endothelial cells (HUVECs) induced by H2O2 and the underlying mechanism.Materials and methods: Primary cultured HUVECs were pretreated with PCA (20, 40 and 80 μg/mL) for 1 h, then HUVEC apoptosis was induced by 300 μmol/mL H2O2. Apoptosis was analyzed by AnnexinV-FITC/PI, and reactive oxygen species (ROS) level was tested by flow cytometry. Colorimetric methods were used to detect the levels of NO and IL-1. In addition, real-time PCR and western blot analyses were used to detect the expression of eNOS and phospho-p38/MAPK.Results: Morphological changes were induced by H2O2 in HUVECs. The cell survival rate was increased by 43.9, 64.0 and 80.6% in each PCA pretreated group (20, 40 and 80 μg/mL) compared to the model group. In each PCA pretreated group, oxidative stress level was also decreased to 54.7, 42.7 and 25.1%. Moreover, the level of IL-1 was decreased to 83.3, 62.2 and 30.7%. The level of NO was increased by 155.9, 232.4 and 317.6%. Apoptosis rate was decreased to 59.0, 47.7 and 32.7%. Phospho-p38 expression was downregulated, but eNOS expression was upregulated.Discussion and conclusion: The results suggest that PCA can effectively protect the endothelial cells from injury induced by H2O2, which may be associated with antioxidation, upregulation of eNOS and downregulation of p38-MAPK.

Screening, tandem expression and immune activity appraisal of Deinagkistrodon acutus (pit viper) venom mimotopes from a phage display 12-mer peptide library.

To design a specific polyclonal antibody against Deinagkistrodon acutus venom (DA-pAb) by immunizating New Zealand white rabbits. The IgG fraction was purified by affinity chromatography, and specific antibodies were purified by immunoaffinity chromatography. Polyclonal antibodies were subjected to ELISA and western blotting to evaluate their immune reactivity. We identified the mimotopes by screening a phage display 12-mer peptide library against D. acutus venom. After three rounds of biopanning with DA-pAb, 30 positive clones were identified. Eighteen phage clones were sequenced, and their corresponding amino acid sequences were deduced. Additional immunoassays with the peptides and DA-pAb identified five sequences as possible epitopes. Recombinant antigens synthesized with the five epitopes were used for the immunization of BALB/c mice. The antibodies induced by these peptides recognized the recombinant antigen and D. acutus venom and protected mice against the hemorrhagic effects of the venom.

First reported case of Deinagkistrodon acutus envenomation in United States. A case report of venom unit interstate response and care

First reported case of Deinagkistrodon acutus envenomation in United States. A case report of venom unit interstate response and care