| direct nephrotoxicity of russell's viper venom demonstrated in the isolated perfused rat kidney. | envenoming by russell's viper (vipera russelli) is an important cause of acute renal failure. the mechanism of renal damage is unresolved. it is difficult to obtain evidence of a direct nephrotoxic action because of the coincidental disturbance to the systemic circulation. we studied the action of russell's viper venom on the function of the isolated perfused rat kidney. direct nephrotoxic action was indicated by a dose dependent decrease in inulin clearance and an increase in fractional excreti ... | 1989 | 2929855 |
| experimental assessment of a new, low-cost antivenom for treatment of carpet viper (echis ocellatus) envenoming. | morbidity and mortality due to envenoming by the carpet viper (echis ocellatus) in northern nigeria remains unacceptably high and constitutes a severe economic and public health problem to the local farming community in particular. the only effective treatment of systemic envenoming is antivenom, but supplies are very limited as the little that is available is either too expensive, ineffective or both. here, we describe a new ovine antivenom, designed both to be effective and to be available at ... | 1995 | 7638870 |
| a comparison of ovine and equine antivenoms. | commercial antivenoms produced in horses were compared with monospecific antivenoms raised in sheep against crotalus durissus terrificus, crotalus atrox, crotalus adamanteus, micrurus fulvius fulvius, naja naja, naja kaouthia, echis ocellatus, vipera lebetina deserti, vipera berus berus and vipera ammodytes ammodytes venom. antibodies raised by immunizing sheep with c. d. terrificus venom were more effective than their equine counterparts in preventing lethal toxicity in mice (ed50), in inhibiti ... | 1994 | 8052997 |
| immunization against echis ocellatus (carpet viper) venom using liposomes incorporating immunostimulants: role of lipopolysaccharide in conferring protection in a mouse model. | varying doses of whole west african echis ocellatus venom were incorporated, with or without immunostimulants, into membrane-stabilized reverse phase evaporation (rev) liposomes. preparations were given either subcutaneously (s.c.) or intravenously (i.v.) to mice and the immune responses compared. addition of lipopolysaccharide (lps) significantly increased the venom antibody response. lipid a produced a less pronounced and less sustained effect and the addition of muramyl dipeptide analogues ma ... | 1993 | 8332992 |
| first clinical experiences with a new ovine fab echis ocellatus snake bite antivenom in nigeria: randomized comparative trial with institute pasteur serum (ipser) africa antivenom. | during the past decade, effective snake antivenoms have become scarce in northern nigeria. as a result, many patients severely envenomed by the saw-scaled or carpet viper (echis ocellatus), which is responsible for more than 95% of the snake bites in the region, did not receive effective treatment and mortality and morbidity increased. to combat this crisis, a new monospecific ovine fab antivenom (echitab) is being developed. its theoretical advantages over conventional equine f(ab')2 antivenom ... | 1997 | 9129531 |
| clinical safety of a polyvalent f(ab')2 equine antivenom in 223 african snake envenomations: a field trial in cameroon. vao (venin afrique de l'ouest) investigators. | a large-scale clinical trials was conducted, according to world health organization good clinical practice guidelines, in 7 centres in north cameroon to determine the safety and efficacy of a polyvalent antivenom composed of purified f(ab')2. this study included 223 patients presenting clinically with obvious snake bite, predominantly due to echis ocellatus (viper), the most abundant species in this savannah region. clinical surveillance was maintained for 5 d in all patients and until the twent ... | 1998 | 10326114 |
| characterization of a monomeric disintegrin, ocellatusin, present in the venom of the nigerian carpet viper, echis ocellatus. | ocellatusin is a new rgd-containing short monomeric disintegrin. it is a better inhibitor of alpha(5)beta(1) integrin and a more potent inducer of the expression of a ligand-induced binding site epitope on beta(1) integrin subunit than echistatin. in further contrast to echistatin, ocellatusin has a direct chemotactic stimulus on human neutrophils in vitro. the distinct effects of these two close evolutionarily related disintegrins might be explained by the presence of methionine-22 and histidin ... | 2002 | 11852062 |
| [comparative titration of three antivenin serums used against sub-saharan african snakes]. | the standardisation of serotherapy is necessary in africa mainly because of the frequency of envenomations and the lack of alternative treatments. comparative titrations of fav-afrique (aventis pasteur), polyvalent serum (serum institute of india = sii) and polyvalent antivenin (south african vaccine fabricants ltd = saimr) were carried out on venoms of echis ocellatus from cameroun, e. ocellatus from mali, e. leucogaster and naja melanoleuca. the 50% protective doses (ed50) of the antivenoms we ... | 2002 | 12404855 |
| [epidemiology of snake envenomations in northern cameroon]. | epidemiological surveys concerning snakebites were carried out in the savannah area of north cameroon according to two methods. a retrospective survey carried out in 5 hospitals or dispensaries covering a 3- to 8-year period according to locality was followed by a prospective survey in 4 of these health centres lasting 1 or 2 years according to location. these studies involved respectively 1,710 and 359 patients. the annual incidence varied between 50 and 250 envenomations per 100,000 inhabitant ... | 2002 | 12404867 |
| tetanus complicating snakebite in northern nigeria: clinical presentation and public health implications. | there is inequality in vaccination coverage, and adult farmers in tropical rural communities could have missed tetanus toxoid as campaigns target children. snakebite is not uncommon and partly because of lack of effective antivenom, management in inaccessible areas could be complicated with tetanus in unimmunized victims. | 2003 | 12505187 |
| formulation of a liquid ovine fab-based antivenom for the treatment of envenomation by the nigerian carpet viper (echis ocellatus). | most antivenoms are required for use in tropical or sub-tropical countries where temperatures may be high and refrigerated storage unavailable or unreliable. although freeze-dried products can be expected to have maximal storage stability, many antivenoms are manufactured in liquid form to lower their cost and ease their use. we developed a liquid formulation of an existing freeze-dried antivenom against the carpet viper (echis ocellatus) for use in nigeria. when fab fragments, prepared from ant ... | 2003 | 14505940 |
| snake bite in nigeria. | four families of venomous snakes are found in nigeria--viperidae, elapidae, colubridae and actraspididae but three species carpet viper (echis ocellatus), black-necked spitting cobra (naja nigricollis) and puff adder (bitis arietans), belonging to the first two families, are the most important snakes associated with envenoming in nigeria. the incidence of bites has been reported as 497 per 100,000 population per year with a 12 percent natural mortality, with echis ocellatus accounting for at lea ... | 2001 | 14510123 |
| novel sequences encoding venom c-type lectins are conserved in phylogenetically and geographically distinct echis and bitis viper species. | envenoming by echis saw scaled vipers and bitis arietans puff adders is the leading cause of death and morbidity in africa due to snake bite. despite their medical importance, the composition and constituent functionality of venoms from these vipers remains poorly understood. here, we report the cloning of cdna sequences encoding seven clusters or isoforms of the haemostasis-disruptive c-type lectin (ctl) proteins from the venom glands of echis ocellatus, e. pyramidum leakeyi, e. carinatus sochu ... | 2003 | 14557069 |
| geographic information system mapping of snakebite incidence in northern ghana and nigeria using environmental indicators: a preliminary study. | snakebite is an important health problem in many parts of rural west africa where the carpet or sawscaled viper, echis ocellatus, is responsible for most of the morbidity and mortality. marked seasonal and geographical variation in the incidence of snakebite suggests an association with environmental factors that could potentially identify high-risk areas and inform health care decision making. this preliminary investigation describes a geographic information system (gis) approach to risk mappin ... | 2003 | 14584375 |
| defibrination and systemic bleeding caused by an imported african snakebite. | a 55-year-old man was referred from burkina fasso for coagulation disorders with severe spontaneous systemic bleeding. he had been bitten six days before by a snake that could not be definitely identified. no specific treatment had been started in africa. the patient was admitted with severe anaemia, incoagulable blood with undetectable fibrinogen. multiple haematomas in the chest and abdomen were found at computed tomography. blood transfusions and the administration of fresh frozen plasma and ... | 2003 | 14676521 |
| the antisnake venom activities of parkia biglobosa (mimosaceae) stem bark extract. | snake bites in rural nigeria are commonly treated with plant extracts. we have studied the ability of one such traditionally used plant (parkia biglobosa; [jacq.] benth., mimosaceae) to reduce the effects of two snake venoms (naja nigricollis, and echis ocellatus) in several experimental models. a water-methanol extract of p. biglobosa stem bark significantly (p<0.001) protected the chick biventer cervicis (cbc) muscle preparation from n. nigricollis venom-induced inhibition of neurally evoked t ... | 2003 | 14757207 |
| antigenic relationships and relative immunogenicities of isolated metalloproteinases from echis ocellatus venom. | the antigenic relationship between snake venom metalloproteinases (svmps) was analysed using rabbit antisera raised against the native forms of two svmps purified from echis ocellatus venom. using enzyme-linked immunosorbent assay (elisa), western blotting and two-dimensional sds-page, our findings show that antibodies raised against eovmp1, a non-haemorrhagic class p-i 24kda svmp, and eovmp2, a haemorrhagic class p-iii 56kda svmp, demonstrate cross-reactivities which relate to the domain hierar ... | 2005 | 15777964 |
| pan-african polyspecific antivenom produced by caprylic acid purification of horse igg: an alternative to the antivenom crisis in africa. | a polyspecific pan-african antivenom has been produced from the plasma of horses immunized with a mixture of the venoms of echis ocellatus, bitis arietans and naja nigricollis, the three most medically important snakes in sub-saharan africa. the antivenom is a whole igg preparation, obtained by caprylic acid precipitation of non-igg plasma proteins. the antivenom effectively neutralizes the most important toxic activities of the three venoms used in the immunization in standard assays involving ... | 2005 | 15837359 |
| effects of three novel metalloproteinases from the venom of the west african saw-scaled viper, echis ocellatus on blood coagulation and platelets. | two metalloproteinases, a 24-kda p-i eovmp1 and a 56-kda p-iii eovmp2, have recently been isolated from the venom of the west african saw-scaled viper echis ocellatus. we now reveal a new 65-kda haemorrhagic group p-iii metalloproteinase which we have designated eovmp3. the aim of this study was to determine whether these three snake venom metalloproteinases (svmps) affect platelets and blood coagulation. eovmp1 had no effect on the aggregation of washed human platelets, whereas eovmp2 inhibited ... | 2005 | 15863354 |
| snakebite in northern cameroon: 134 victims of bites by the saw-scaled or carpet viper, echis ocellatus. | echis ocellatus is one of the most deadly snakes known to humans, yet the procurement of antivenom for the treatment of these snakebites in africa has become increasingly difficult and expensive. there is no consensus for the management of victims, and little is known of actual recent experiences with these cases in ordinary health care settings in africa. all cases of snakebite reliably identified as bites of e. ocellatus and admitted to kolofata district hospital, northern cameroon, from janua ... | 2003 | 16117965 |
| neutralisation of venom-induced haemorrhage by igg from camels and llamas immunised with viper venom and also by endogenous, non-igg components in camelid sera. | envenoming by snakes results in severe systemic and local pathology. intravenous administration of antivenom, prepared from igg of venom immunised horses or sheep, is the only effective treatment of systemic envenoming. conventional antivenoms, formulated as intact igg, papain-cleaved (fab) or pepsin-cleaved f(ab')2 fragments, are however ineffective against the local venom effects because of their inability to penetrate the blood/tissue barrier. we have embarked on a new research program to exa ... | 2006 | 16359717 |
| [envenomation accidents caused by snakebites in the surgical emergency unit of gabriel-touré hospital, bamako, mali (1998-1999)]. | this study aimed at assessing envenomations caused by snakebite in the gabriel touré hospital between january 1998 and december 1999. we included in total 112 victims of snakebites proved by the identification of the snake, the fangs traces and envenomation signs. the bites concerned 34 women (30.36%) versus 78 men (69.64%) from the bamako district, while 66.7% were from a rural environment. the farmers were the most affected category (35.1%). the bite concerned the lower limb in 83.3% of the ca ... | 2005 | 16402577 |
| [biogeographical distribution of snakes in cameroon: the case of venomous snakes]. | a preliminary analysis of the distribution of snakes captured in cameroon between 1999 and 2004 is presented in this study. this work helps to provide a better understanding of the distribution of the venomous snakes. the main focus of this study was to identify regions of high diversity of venomous species, a useful step towards developing a national strategy of snakebite care and antivenom distribution. we recorded 4,910 specimens of 150 species from 361 localities throughout cameroon. among t ... | 2005 | 16402580 |
| bioinformatics and multiepitope dna immunization to design rational snake antivenom. | snake venom is a potentially lethal and complex mixture of hundreds of functionally diverse proteins that are difficult to purify and hence difficult to characterize. these difficulties have inhibited the development of toxin-targeted therapy, and conventional antivenom is still generated from the sera of horses or sheep immunized with whole venom. although life-saving, antivenoms contain an immunoglobulin pool of unknown antigen specificity and known redundancy, which necessitates the delivery ... | 2006 | 16737347 |
| the anti-snake venom activities of the methanolic extract of the bulb of crinum jagus (amaryllidaceae). | the anti-snake venom activities of the methanolic extract of the bulb of crinum jagus plant (amaryllidaceae) were investigated in vitro and in vivo against the venoms of three notable snake species: echis ocellatus, bitis arietans and naja nigricollis. the extract was prepared by cold marceration in 50% methanol at 37 degrees c with intermittent shaking for 48 h. an yield of 12.8% w/w dry extract was obtained. oral administration of c. jagus extract (1000 mg/kg) protected 50% of mice, while inje ... | 2006 | 16890262 |
| poxviruses as possible vectors for horizontal transfer of retroposons from reptiles to mammals. | poxviruses (poxviridae) are a family of double-stranded dna viruses with no rna stage. members of the genus orthopoxvirus (opv) are highly invasive and virulent. it was recently shown that the taterapox virus (tatv) from a west african rodent is the sister of camelpox virus and therefore belongs to the clade closest to the variola virus (varv), the etiological agent of smallpox. although these opvs are among the most dreaded pathogens on earth, our current knowledge of their genomes, their origi ... | 2007 | 17623783 |
| [study of the action of black stone (also known as snakestone or serpent stone) on experimental envenomation]. | black stone has been used since antiquity to treat snake bites and local infections. its efficacy is debated. since no clinical trial has been performed, we conducted a series of in vivo and in vitro experiments in a murine model. after determining the ld50 of batches of venoms of bitis arietans, echis ocellatus and naja nigricollis according to the spearman-kärber's method, we used four separate methods. first, we injected a fixed lethal amount of venom (triple the ld50) im to the shaved thighs ... | 2007 | 18180213 |
| characterization of a new polyvalent antivenom (antivipmyn africa) against african vipers and elapids. | as a response to the antivenom shortage in sub-saharan africa, evident for well over a decade, we developed a new polyvalent anti-ophidian antivenom (antivipmyn((r)) africa) designed for use in the region. we report a detailed characterization of its biochemical composition (protein content and profiling by size-exclusion chromatography and electrophoresis) as well as the specific and para-specific neutralization potencies (as median effective dose in the mouse lethality test). additionally, we ... | 2008 | 18926842 |
| pre-clinical and preliminary dose-finding and safety studies to identify candidate antivenoms for treatment of envenoming by saw-scaled or carpet vipers (echis ocellatus) in northern nigeria. | the aim of this study was to identify candidate antivenoms with specific activity against the venom of the saw-scaled or carpet viper (echis ocellatus) in northern nigeria, where bites by this species cause great morbidity and mortality but where effective antivenoms have become scarce and unaffordable. selected antivenoms were destined to be compared by randomised controlled clinical trials (rcts). standard pre-clinical neutralisation assays were carried out in rodents. we included two licensed ... | 2010 | 19874841 |
| analysis of camelid igg for antivenom development: serological responses of venom-immunised camels to prepare either monospecific or polyspecific antivenoms for west africa. | snake envenoming is a significant cause of mortality and morbidity in sub-saharan africa. the only effective treatment, antivenom, has been in short supply since the 1990s. whilst the humanitarian response by some antivenom producers has significantly improved the situation, strategies to ensure the long term stability of antivenom supply are still necessary. we are investigating whether the potential safety and logistic advantages of camel igg antivenom can be exploited to improve antivenom pro ... | 2010 | 20362604 |
| analysis of camelid antibodies for antivenom development: neutralisation of venom-induced pathology. | camelid igg has been reported to be less immunogenic, less able to activate the complement cascade and more thermostable than igg from other mammals, and has the ability to bind antigens that are unreactive with other mammalian iggs. we are investigating whether these attributes of camelid igg translate into antivenom with immunological and venom-neutralising efficacy advantages over conventional equine and ovine antivenoms. the objective of this study was to determine the preclinical venom-neut ... | 2010 | 20412814 |
| analysis of camelid igg for antivenom development: immunoreactivity and preclinical neutralisation of venom-induced pathology by igg subclasses, and the effect of heat treatment. | antivenom is the most effective treatment of snake envenoming and is manufactured from the igg of venom-immunised horses and sheep. camelids have a unique igg structure which may account for the report that camel igg is less immunogenic and less likely to activate complement than equine or ovine igg. camelid igg therefore offers potential safety advantages over conventional iggs used for antivenom manufacture. the reported thermostability of camelid igg also holds promise in the inclusion of a r ... | 2010 | 20547172 |
| antisnake venom activity of hibiscus aethiopicus l. against echis ocellatus and naja n. nigricollis. | the objective of the study is to investigate whether the hibiscus aethiopicus l. plant has neutralization activity against venoms of two clinically important snakes. the h. aethiopicus was dried and extracted with water. different assays were performed to evaluate the plant's acute toxicity and its anti-snake venom activities. the results showed that h. aethiopicus extract alone had no effect on the viability of c(2)c(12) muscle cells, but significantly (p < .05) protected muscle cells against t ... | 2010 | 20628507 |
| randomised controlled double-blind non-inferiority trial of two antivenoms for saw-scaled or carpet viper (echis ocellatus) envenoming in nigeria. | in west africa, envenoming by saw-scaled or carpet vipers (echis ocellatus) causes great morbidity and mortality, but there is a crisis in supply of effective and affordable antivenom (isrctn01257358). | 2010 | 20668549 |
| purification, characterization and antibacterial activity of l-amino acid oxidase from cerastes cerastes. | antibiotic resistance presents a real problem in which new antibacterial molecules from natural secretions could be beneficial in the development of new drugs. in this study, cerastes cerastes venom was investigated for its antibacterial activity against gram-positive and gram-negative bacteria. the antibacterial activity was evaluated by measuring the halo inhibition and minimum inhibitory concentration (mic). an l-amino acid oxidase (cclaao) was purified from this venom using three chromatogra ... | 2014 | 24817275 |
| cytotoxic activities of [ser⁴⁹]phospholipase a₂ from the venom of the saw-scaled vipers echis ocellatus, echis pyramidum leakeyi, echis carinatus sochureki, and echis coloratus. | fractionation by reversed-phase hplc of venom from four species of saw-scaled viper: echis ocellatus, echis pyramidum leakeyi, echis carinatus sochureki, and echis coloratus led to identification in each sample of an abundant protein with cytotoxic activity against human non-small cell lung adenocarcinoma a549 cells. the active component in each case was identified by maldi-tof mass fingerprinting of tryptic digests as [ser⁴⁹]phospholipase a₂ ([ser⁴⁹]pla₂). an isoform of [ser⁴⁹]pla₂ containing t ... | 2013 | 23747272 |
| identification of cdnas encoding viper venom hyaluronidases: cross-generic sequence conservation of full-length and unusually short variant transcripts. | the immobilisation of prey by snakes is most efficiently achieved by the rapid dissemination of venom from its site of injection into the blood stream. hyaluronidase is a common component of snake venoms and has been termed the "venom spreading factor". in the absence of nucleotide or protein sequence data to confirm the functional identity of this venom component, we interrogated a venom gland est database for the saw-scaled viper, echis ocellatus (nigeria), using the gene ontology (go) term "c ... | 2007 | 17210232 |
| expanding the neutralization scope of the echitab-plus-icp antivenom to include venoms of elapids from southern africa. | echitab-plus-icp is an antivenom prepared from plasma of horses hyperimmunized with the venoms of the carpet viper (echis ocellatus), the puff adder (bitis arietans) and the black-necked spitting cobra (naja nigricollis). therefore, the use of this antivenom has been limited to western africa. in order to expand the neutralization scope of echitab-plus-icp, we supplemented the immunogenic mixture with the venoms of b. arietans, the black mamba (dendroaspis polylepis), the mozambique spitting cob ... | 2017 | 27890775 |
| effect of geographical variation of echis ocellatus, naja nigricollis and bitis arietans venoms on their neutralization by homologous and heterologous antivenoms. | two antivenoms prepared by using echis ocellatus, bitis arietans and naja nigricollis venoms from different locations in sub-saharan africa were compared for their neutralizing ability. both antivenoms were similarly effective in the neutralization of the venoms of the three species from different locations. however in the case of e. ocellatus venom, antivenom prepared using venom from nigerian specimens was more effective than antivenom prepared with venom from cameroon specimens in the neutral ... | 2015 | 26450770 |
| vtbuilder: a tool for the assembly of multi isoform transcriptomes. | within many research areas, such as transcriptomics, the millions of short dna fragments (reads) produced by current sequencing platforms need to be assembled into transcript sequences before they can be utilized. despite recent advances in assembly software, creating such transcripts from read data harboring isoform variation remains challenging. this is because current approaches fail to identify all variants present or they create chimeric transcripts within which relationships between co-evo ... | 2014 | 25465054 |
| public health aspects of snakebite care in west africa: perspectives from nigeria. | snakebite envenoming is a major public health problem among rural communities of the nigerian savanna. the saw-scaled or carpet viper (echis ocellatus) and, to a lesser extent, the african cobras (naja spp.) and puff adders (bitis arietans) have proved to be the most important cause of mortality and morbidity. the main clinical features of e. ocellatus envenoming are systemic hemorrhage, incoagulable blood, shock, local swelling, bleeding and, occasionally, necrosis. bites may be complicated by ... | 2013 | 24134780 |
| second generation snake antivenomics: comparing immunoaffinity and immunodepletion protocols. | a second generation antivenomics protocol, based on affinity chromatography, was compared with a previously (first generation) immunodepletion protocol using as a proof of principle the pan-african echitab-plus-icp(®) igg antivenom and the venoms of echis ocellatus, bitis arietans, and african spitting cobras. the antivenom showed qualitatively similar immunoreactivity patterns using either antivenomic approach. quantitative departures were noticed between both methods, which may be ascribed to ... | 2012 | 22561422 |
| antivenomic assessment of the immunological reactivity of echitab-plus-icp, an antivenom for the treatment of snakebite envenoming in sub-saharan africa. | the immunoreactivity of echitab-plus-icp, an antivenom developed for the treatment of snakebite envenoming in sub-saharan africa, to venoms of seven echis and bitis species, was assessed by "antivenomics." this proteomic approach is based on the ability of an antivenom to immunodeplete homologous or heterologous venom proteins. our results show an extensive cross-reactivity of this antivenom against all echis and bitis venoms studied, as revealed by the complete immunodepletion of the majority o ... | 2010 | 20519622 |
| preclinical assessment of the efficacy of a new antivenom (echitab-plus-icp) for the treatment of viper envenoming in sub-saharan africa. | a preclinical assessment was performed on the neutralizing efficacy of a whole igg polyspecific antivenom (echitab-plus-icp), designed for the treatment of snakebite envenomings in nigeria. it was generated by immunizing horses with the venoms of echis ocellatus, bitis arietans and naja nigricollis, the most medically important species in nigeria. antivenom was tested against the venoms of e. ocellatus, echis leucogaster, echis pyramidum leakeyi, b. arietans, bitis gabonica, bitis rhinoceros and ... | 2010 | 19699756 |
| study of the efficacy of the black stone on envenomation by snake bite in the murine model. | the black stone (bs) has been used since antiquity to treat envenomations. since no actual clinical trial has ever been performed we used an experimental approach to evaluate its efficacy against the venoms of bitis arietans, echis ocellatus and naja nigricollis. local application of bs after intramuscular venom injection had no demonstrable effect on the outcome of envenomationa and it did not change the ld(50) of b. arietans venom. our results show that, contrary to widespread belief, no effic ... | 2007 | 17174999 |
| [mortality from snake bites, wild and domestic animal bites and arthropod stings in the savannah zone of eastern senegal]. | from 1976 to 1999, we conducted a prospective study of overall and cause-specific mortality among the population of 42 villages of south-eastern senegal. of 4,228 deaths registered during this period, 26 were brought on by snakebites, 4 by invertebrate stings and 8 by other wild or domestic animals. the average annual mortality rate from snakebite was 14 deaths per 100,000 population. among persons aged 1 year or more, 0.9% (26/2,880) of deaths were caused by snakebite and this cause represented ... | 2002 | 12404858 |
| high mortality from snakebite in south-eastern senegal. | over 24 years, from 1976 to 1999, we conducted a prospective study of overall and cause-specific mortality among the population of 42 villages of south-eastern senegal. of 4228 deaths registered during this period, 26 were caused by snakebite, 4 by invertebrate stings and 8 by other wild or domestic animals. the average annual mortality rate from snakebite was 14 deaths per 100,000 population. among persons aged > or = 1 year, 0.9% (26/2880) of deaths were caused by snakebite and this cause repr ... | 2004 | 11579888 |
| molecular diversity of snake venom nerve growth factors. | nerve growth factor (ngf) is a protein which stimulates the differentiation and maintenance of sympathetic and embryonic sensory neurons. snake venoms are a rich source of ngf. due to small quantities it is sometimes difficult and laborious to isolate ngf from the venoms. in this study the use of ni-nta-agarose for isolation of ngf is studied. anti-vipera lebetina ngf antibodies were used for identification of ngf during ni-nta-agarose fractionation as well as for cross-reaction studies with 21 ... | 2011 | 21801740 |
| serine protease variants encoded by echis ocellatus venom gland cdna: cloning and sequencing analysis. | envenoming by echis saw-scaled viper is the leading cause of death and morbidity in africa due to snake bite. despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. here, we report the cloning of cdna sequences encoding four groups or isoforms of the haemostasis-disruptive serine protease proteins (sps) from the venom glands of echis ocellatus. all these sp sequences encoded the cysteine residues scaffold that form the 6-disulphi ... | 2010 | 20936075 |
| first draft of the genomic organization of a piii-svmp gene. | the evolutionary pathway of highly toxic proteins expressed in snake venom glands from proteins without toxic function and expressed in non-parotid tissues remains poorly understood. here we examine gene structure of a representative of a venom protein with an adams metalloproteinase evolutionary origin. the structure of the 15,652 bp echis ocellatus pre-pro eoc00089-like piii-svmp gene was assembled from pcr-amplified sequences of overlapping genomic fragments. the gene comprises 12 exons inter ... | 2012 | 22543188 |
| isolation and characterization of renin-like aspartic-proteases from echis ocellatus venom. | three aspartic proteases (svaps) have been isolated from venom of the saw-scaled viper, echis ocellatus. in confirmation of prior transcriptomic predictions, all three forms match to sequences of either of the two svap transcripts (eoc00051 and eoc00123), have a molecular weight of 42 kda and possess a single n-glycan. the svaps act in a renin-like manner, specifically cleaving human and porcine angiotensinogen into angiotensin-1 and possess no general protease activity. their activity is comple ... | 2017 | 28734982 |
| preclinical evaluation of three polyspecific antivenoms against the venom of echis ocellatus: neutralization of toxic activities and antivenomics. | snakebite envenoming has a heavy burden in the public health in sub-saharan africa. the viperid species echis ocellatus (carpet viper or saw-scaled viper) is the medically most important snake in the savannahs of western sub-saharan africa. several antivenoms are being distributed and used in this region for the treatment of envenomings by e. ocellatus, but the preclinical efficacy of some of these antivenoms has not been assessed. the present study evaluated the preclinical efficacy against e. ... | 2016 | 27377229 |
| antivenom therapy of carpet viper (echis ocellatus) envenoming: effectiveness and strategies for delivery in west africa. | in west africa, response to specific, geographically appropriate, antivenom is often dramatic following carpet viper (echis ocellatus) envenoming with rapid restoration of blood coagulability and resolution of spontaneous haemorrhage. envenoming from australasian snakes causing similar coagulopathies may respond less dramatically and the effectiveness of antivenom is being questioned. here we have reviewed and re-analysed all published preclinical and clinical studies on envenoming and antivenom ... | 2013 | 23339853 |
| long-term physicochemical and immunological stability of a liquid formulated intact ovine immunoglobulin-based antivenom. | an antivenom should be stable under the conditions that it will be both transferred and stored. thus instability may lead to a loss of efficacy and an increased incidence and severity of adverse effects. stability is a particular problem in countries where the temperatures and humidity are high. here we investigate the stability of a liquid-formulated, intact ovine immunoglobulin-based antivenom, echitabg™, which is used extensively in nigeria to treat envenoming by the west african saw-scaled v ... | 2013 | 23319075 |
| combined snake venomics and venom gland transcriptomic analysis of the ocellated carpet viper, echis ocellatus. | snakebite in africa causes thousands of deaths annually and considerable permanent physical disability. the saw-scaled viper, echis ocellatus, represents the single most medically important snake species in west africa. to provide a detailed compositional analysis of the venom of e. ocellatus for designing novel toxin-specific immunotherapy and to delineate sequence structure-function relationships of individual toxins, we characterised the venom proteome and the venom gland transcriptome. whole ... | 2009 | 19026773 |
| neutralization of the haemorrhagic activities of viperine snake venoms and venom metalloproteinases using synthetic peptide inhibitors and chelators. | envenoming by the west african saw-scaled viper, echis ocellatus resembles that of most vipers, in that it results in local blistering, necrosis and sometimes life-threatening systemic haemorrhage. while effective against systemic envenoming, current antivenoms have little or no effect against local tissue damage. the major mediators of local venom pathology are the zinc-dependant snake venom metalloproteinases (svmps). the high degree of structural and functional homology between svmps and thei ... | 2007 | 17196631 |
| venom gland est analysis of the saw-scaled viper, echis ocellatus, reveals novel alpha9beta1 integrin-binding motifs in venom metalloproteinases and a new group of putative toxins, renin-like aspartic proteases. | echis ocellatus is the most medically important snake in west africa. however, the composition of its venom and the differential contribution of these venom components to the severe haemorrhagic and coagulopathic pathology of envenoming are poorly understood. to address this situation we assembled a toxin transcriptome based upon 1000 expressed sequence tags (est) from a cdna library constructed from pooled venom glands of 10 individual e. ocellatus. we used a variety of bioinformatic tools to c ... | 2006 | 16713134 |
| cloning of a prothrombin activator-like metalloproteinase from the west african saw-scaled viper, echis ocellatus. | systemic envenoming by the saw-scaled viper, echis ocellatus, is responsible for more deaths than any other snake in west africa. despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. here we describe the isolation of e. ocellatus venom gland cdnas encoding a protein of 514 amino acids that showed 91% sequence similarity to ecarin, a prothrombin-activating metalloproteinase from the venom of the east african viper, e. pyramidum ... | 2003 | 14602118 |
| molecular cloning of phospholipases a(2) from venom glands of echis carpet vipers. | venom toxin-specific antibodies offer a more rational treatment of snake envenoming than conventional antivenom. here, we describe novel cdnas encoding phospholipase a(2) (pla(2)) isoforms from venom gland rna of echis pyramidum leakeyi (epl), echis sochureki (es) and echis ocellatus (eo). the deduced amino acid sequences of these cdnas encoded proteins with high overall sequence identity to the viper group ii pla(2) protein family, including the 14 cysteine residues capable of forming seven dis ... | 2003 | 12875867 |
| comparative biochemistry of disintegrins isolated from snake venom: consideration of the taxonomy and geographical distribution of snakes in the genus echis. | species in the genus echis have been classified mainly based on their morphological appearance and the analytical patterns of their serum. however, re-classification of the genus echis has recently been suggested by taxonomists, toxicologists, and clinicians, since there have been problems with the current classification, such as the efficacy of antivenoms used for treating bites and the broad geographical distribution of echis snakes. in this study, we purified five novel disintegrins, the plat ... | 2001 | 11275562 |
| snake venom disintegrins: novel dimeric disintegrins and structural diversification by disulphide bond engineering. | we report the isolation and amino acid sequences of six novel dimeric disintegrins from the venoms of vipera lebetina obtusa (vlo), v. berus (vb), v. ammodytes (va), echis ocellatus (eo) and echis multisquamatus (ems). disintegrins vlo4, vb7, va6 and eo4 displayed the rgd motif and inhibited the adhesion of k562 cells, expressing the integrin alpha5beta1 to immobilized fibronectin. a second group of dimeric disintegrins (vlo5 and eo5) had mld and vgd motifs in their subunits and blocked the adhe ... | 2003 | 12667142 |
| an improved technique for the assessment of venom-induced haemorrhage in a murine model. | haemorrhage is a common clinical manifestation in envenomings caused by bites from snakes of the family viperidae. therefore, knowing the haemorrhagic potential of venoms and the capacity of antivenoms to neutralise this effect are of paramount relevance in toxinology. the most widely used method for quantifying haemorrhage involves the intradermal injection of venom (or a mixture of venom/antivenom) in mice, and the assessment of the resulting haemorrhagic area in the inner side of the skin. al ... | 2017 | 29024773 |
| freeze-dried echitab+icp antivenom formulated with sucrose is more resistant to thermal stress than the liquid formulation stabilized with sorbitol. | echitab + icp is a pan-african antivenom used for the treatment of snakebite envenomation in rural sub-saharan african communities, where the cold chain can be difficult to maintain. to develop a formulation of echitab + icp that can be distributed and stored without refrigeration, we submitted three different formulations of echitab + icp: control (i.e. liquid antivenom formulated without stabilizer), liquid antivenom stabilized with sorbitol, and freeze-dried antivenom formulated with sucrose, ... | 2017 | 28478057 |
| peptidomimetic hydroxamate metalloproteinase inhibitors abrogate local and systemic toxicity induced by echis ocellatus (saw-scaled) snake venom. | the ability of two peptidomimetic hydroxamate metalloproteinase inhibitors, batimastat and marimastat, to abrogate toxic and proteinase activities of the venom of echis ocellatus from cameroon and ghana was assessed. since this venom largely relies for its toxicity on the action of zinc-dependent metalloproteinases (svmps), the hypothesis was raised that toxicity could be largely eliminated by using svmp inhibitors. both hydroxamate molecules inhibited local and pulmonary hemorrhagic, in vitro c ... | 2017 | 28400263 |
| hemorrhagic metalloproteinase, cc hsm-iii, isolated from cerastes cerastes venom: purification and biochemical characterization. | snake venom metalloproteinases are the most abundant toxins in viperidae venoms. in this study, a new hemorrhagin, cc hsm-iii (66 kda), was purified from cerastes cerastes venom by gel filtration, ion exchange, and reversed-phase high-performance liquid chromatographies. the analysis of cc hsm-iii by liquid chromatography with a tandem mass spectrometry revealed 32 peptides sharing a homology with p-iii metalloproteinases from echis ocellatus snake venom. cc hsm-iii displays hemorrhagic activity ... | 2017 | 28245079 |
| comparison of the adjuvant activity of emulsions with different physicochemical properties on the antibody response towards the venom of west african carpet viper (echis ocellatus). | adjuvant emulsions are widely used to enhance the antibody response of the animals used as immunoglobulin source for producing antivenoms. usually, the adjuvant activity of emulsions is attributed both to their ability to trigger "danger" signals from cells in which they induce death, and to form depots from which immunogens are slowly released. however, there is contradictory evidence suggesting that adjuvant activity of emulsions is independent of the dispersion type and the rate of immunogen ... | 2017 | 28088478 |
| insights into the evolution of a snake venom multi-gene family from the genomic organization of echis ocellatus svmp genes. | the molecular events underlying the evolution of the snake venom metalloproteinase (svmp) family from an a disintegrin and metalloproteinase (adam) ancestor remain poorly understood. comparative genomics may provide decisive information to reconstruct the evolutionary history of this multi-locus toxin family. here, we report the genomic organization of echis ocellatus genes encoding svmps from the pii and pi classes. comparisons between them and between these genes and the genomic structures of ... | 2016 | 27420095 |
| evaluation of the preclinical efficacy of four antivenoms, distributed in sub-saharan africa, to neutralize the venom of the carpet viper, echis ocellatus, from mali, cameroon, and nigeria. | snakebite envenoming causes a heavy toll in sub-saharan africa in terms of mortality and sequelae. in the west african savannah, the viperid echis ocellatus is responsible for the vast majority of bites. in the last decades, several new antivenoms have been introduced for the treatment of these envenomings, although the assessment of their preclinical efficacy against the venom of e. ocellatus has been studied only for some of them. this work analyzed comparatively the ability of four antivenoms ... | 2015 | 26415904 |
| detoxification of echis ocellatus venom-induced toxicity by annona senegalensis pers. | different fractions (i-v) of the methanolic leaf extracts of annona senegalensis were assessed for their anti-snake venom activities. fractions iii neutralized lethal toxicity induced by echis ocellatus venom and manifested the same potency as the crude extracts against the venom. the anti-snake venom activity of fraction iii was clearly shown by the complete abrogation of venom-induced haemorrhage and the 75% record of surviving mice which were injected with a pre-incubate of venom and extract ... | 2014 | 24867285 |
| incidence of snakebites in kaltungo, gombe state and the efficacy of a new highly purified monovalent antivenom in treating snakebite patients from january 2009 to december 2010. | between 2009 and 2010 there were increasing incidences of snakebites in kaltungo, gombe state, nigeria. most of the cases presented were treated with the clinically approved drug of choice for snakebite, the echitab® antisnake venom (asv) at the kaltungo treatment centre which was manufactured by micropharm ltd, uk and produced in collaboration with the liverpool school of hygiene and tropical medicine. a total of 5,367 snakebite victims were treated for the two years under review with 82 deaths ... | 2012 | 22851309 |
| relationship between bite-to-hospital time and morbidity in victims of carpet viper bite in north-central nigeria. | envenomation from snake bites is a public health hazard in tropical countries. the observed mortality among in-hospital patients bitten by carpet viper (echis ocellatus) in northern nigeria has drastically reduced, related to the use of a mono-specific ovine fab anti-snake venom. however, many victims survive with temporary or permanent physical or psychological sequelae. | 2012 | 22752823 |
| snake bites in moyen chari district, chad: a five-year experience. | snake bites are of major public health importance in africa as a cause of morbidity and mortality. echis ocellatus is responsible for the majority of envenomation cases in west africa. antivenom immunotherapy is the only specific treatment available for envenomed patients. from january 1997 to december 2001, 325 patients suffering from snake bites were enrolled in a survey undertaken at goundi hospital, chad. we analysed the percentage of envenomed patients, sex distribution, distribution along ... | 2011 | 21303988 |
| the effect of pre-hospital care for venomous snake bite on outcome in nigeria. | we studied pre-hospital practices of 72 consecutive snake bite victims at a hospital in north-central nigeria. the primary outcome assessed was death or disability at hospital discharge. victims were predominantly male farmers, and in 54 cases (75%) the snake was identified as a carpet viper (echis ocellatus), with the remainder unidentified. most subjects (58, 81%) attempted at least one first aid measure after the bite, including tourniquet application (53, 74%), application (15, 21%) or inges ... | 2011 | 21035155 |
| comment on: failure of a new antivenom to treat echis ocellatus snake bite in rural ghana: the importance of quality surveillance. | | 2009 | 19586649 |
| envenoming after carpet viper (echis ocellatus) bite during pregnancy: timely use of effective antivenom improves maternal and foetal outcomes. | the report describes successful management of 10 women in 2nd and 3rd pregnancy trimesters with echitab igg antivenom after carpet viper (echis ocellatus) envenoming. all women survived but foetal loss in a victim with delayed presentation and a case of mild hypersensitivity reaction were recorded. excellent outcomes can be achieved in rural and semi-nomadic populations without specialized care and immediate access and provision of effective antivenoms is paramount in curtailing snakebite matern ... | 2008 | 18631310 |
| unscrupulous marketing of snake bite antivenoms in africa and papua new guinea: choosing the right product--'what's in a name?'. | snake bite envenoming, mainly caused by the saw-scaled or carpet viper (echis ocellatus), is a neglected disease of west africa. specific antivenoms can save life and limb but, for various reasons, supply of these essential drugs to africa has dwindled to less than 2% of estimated requirements. other problems include maldistribution, inadequate conservation and inappropriate clinical use of antivenoms. in the face of this crisis, several promising new antivenoms have been developed. however, som ... | 2008 | 18359053 |
| failure of a new antivenom to treat echis ocellatus snake bite in rural ghana: the importance of quality surveillance. | this study compares two antivenoms used to treat echis ocellatus snake bite patients at mathias hospital, yeji, central ghana. fav-afrique antivenom (aventis pasteur) was given to 278 patients during 2001--2003, whilst asna antivenom c (bharat serum and vaccines ltd) was used in 2004 to treat 66 patients. the two groups had comparable patient attributes, time from snake bite to treatment and staff adherence to the tested treatment protocol. the antivenom c group required more repeat doses and tw ... | 2008 | 18190937 |
| molecular characterisation of endogenous snake venom metalloproteinase inhibitors. | viper venoms contain one of the most potent mixtures of proteases in natural existence and yet the venom gland and proteins in this mixture are refractory to degradation. here we demonstrate that the sub-10-kda components of venom from two african viper species (echis ocellatus and cerastes cerastes cerastes) are predominantly composed of the tri-peptide pyroglutamate-lysine-tryptophan (pekw). this tripeptide is encoded by tandemly repeating elements and, in e. ocellatus, on the same transcript ... | 2008 | 18029259 |
| loss of introns along the evolutionary diversification pathway of snake venom disintegrins evidenced by sequence analysis of genomic dna from macrovipera lebetina transmediterranea and echis ocellatus. | analysis of cdnas from macrovipera lebetina transmediterranea (mlt) and echis ocellatus (eo) venom gland libraries encoding disintegrins argued strongly for a common ancestry of the messengers of short disintegrins and those for precursors of dimeric disintegrin chains. we now report the sequence analysis of disintegrin-coding genes from these two vipers. genomic dnas for dimeric disintegrin subunits ml_g1 and ml_g2 (mlt) and eo_d3 (eo) contain single 1-kb introns exhibiting the 5'-gtaag (donor) ... | 2007 | 17177090 |
| molecular cloning of echis ocellatus disintegrins reveals non-venom-secreted proteins and a pathway for the evolution of ocellatusin. | we report the cloning and sequence analysis of echis ocellatus cdnas coding for dimeric disintegrin subunits and for the short disintegrin ocellatusin. all the dimeric disintegrin subunit messengers belong to the short-coding class, indicating that short messengers may be more widely distributed than previously thought. mass spectrometric analysis of the hplc-separated venom proteins was performed to characterize the dimeric disintegrins expressed in the venom proteome. in addition to previously ... | 2006 | 16830094 |
| the purification and partial characterisation of two novel metalloproteinases from the venom of the west african carpet viper, echis ocellatus. | separation of previously uncharacterised echis ocellatus venom by phenyl-superose fplc (fast liquid protein chromatography) yielded eight protein fractions. three of these displayed high proteolytic activity when assayed by in vivo and in vitro assays (including enzyme linked immunosorbant assay), and were further separated using superdex 75 and mono-q fplc. this resulted in the purification of a non-haemorrhagic 24 kda metalloproteinase (eovmp1, pi 7.0), and a haemorrhagic 56 kda metalloprotein ... | 2003 | 12893057 |
| varespladib inhibits the phospholipase a2 and coagulopathic activities of venom components from hemotoxic snakes. | phospholipase a2 (pla2) enzymes are important toxins found in many snake venoms, and they can exhibit a variety of toxic activities including causing hemolysis and/or anticoagulation. in this study, the inhibiting effects of the small molecule pla2 inhibitor varespladib on snake venom pla2s was investigated by nanofractionation analytics, which combined chromatography, mass spectrometry (ms), and bioassays. the venoms of the medically important snake species bothrops asper, calloselasma rhodosto ... | 2020 | 32560391 |
| development of high-throughput screening assays for profiling snake venom phospholipase a2 activity after chromatographic fractionation. | many organisms, ranging from plants to mammals, contain phospholipase a2 enzymes (pla2s), which catalyze the production of lysophospholipids and fatty acid proinflammatory mediators. pla2s are also common constituents of animal venoms, including bees, scorpions and snakes, and they cause a wide variety of toxic effects including neuro-, myo-, cyto-, and cardio-toxicity, anticoagulation and edema. the aim of this study was to develop a generic method for profiling enzymatically active pla2s in sn ... | 2020 | 32502555 |
| an in vivo examination of the differences between rapid cardiovascular collapse and prolonged hypotension induced by snake venom. | we investigated the cardiovascular effects of venoms from seven medically important species of snakes: australian eastern brown snake (pseudonaja textilis), sri lankan russell's viper (daboia russelii), javanese russell's viper (d. siamensis), gaboon viper (bitis gabonica), uracoan rattlesnake (crotalus vegrandis), carpet viper (echis ocellatus) and puff adder (bitis arietans), and identified two distinct patterns of effects: i.e. rapid cardiovascular collapse and prolonged hypotension. p. texti ... | 2019 | 31882843 |
| neutralizing effects of small molecule inhibitors and metal chelators on coagulopathic viperinae snake venom toxins. | animal-derived antivenoms are the only specific therapies currently available for the treatment of snake envenoming, but these products have a number of limitations associated with their efficacy, safety and affordability for use in tropical snakebite victims. small molecule drugs and drug candidates are regarded as promising alternatives for filling the critical therapeutic gap between snake envenoming and effective treatment. in this study, by using an advanced analytical technique that combin ... | 2020 | 32825484 |
| epidemiology, ecology and human perceptions of snakebites in a savanna community of northern ghana. | worldwide, snakebite envenomations total ~2.7 million reported cases annually with ~100,000 fatalities. since 2009, snakebite envenomation has intermittently been classified as a very important 'neglected tropical disease' by the world health organisation. despite this emerging awareness, limited efforts have been geared towards addressing the serious public health implications of snakebites, particularly in sub-saharan africa, where baseline epidemiological and ecological data remain incomplete ... | 2019 | 31369551 |
| reviewing evidence of the clinical effectiveness of commercially available antivenoms in sub-saharan africa identifies the need for a multi-centre, multi-antivenom clinical trial. | snakebite envenoming kills more than more than 20,000 people in sub-saharan africa every year. poorly regulated markets have been inundated with low-price, low-quality antivenoms. this review aimed to systematically collect and analyse the clinical data on all antivenom products now available in markets of sub-saharan africa. | 2019 | 31233536 |
| successful management of two patients with intracranial hemorrhage due to carpet viper (echis ocellatus) envenomation in a limited-resource environment. | the west african carpet viper (echis ocellatus) causes more deaths than any other snake in sub-saharan africa. carpet viper envenomations are characterized by a venom-induced consumption coagulopathy and systemic bleeding syndrome, in addition to local symptoms of painful progressive swelling and tissue destruction. the highest mortality rate is seen in the final stages of the syndrome, which typically ends with fatal internal bleeding or hemorrhagic shock. we present 2 cases of e ocellatus enve ... | 2019 | 31229367 |
| development of a generic high-throughput screening assay for profiling snake venom protease activity after high-resolution chromatographic fractionation. | snakebites cause upwards of 1.8 million envenomings, 138,000 deaths and 500,000 cases of long term morbidity each year. viper snake venoms (family viperidae) generally contain a high proportion of proteases which can cause devastating effects such as hemorrhage, coagulopathy, edema, necrosis, and severe pain, in envenomed victims. in this study, analytical techniques were combined with enzymatic assays to develop a novel method for the detection of snake venom protease activity by using rhodamin ... | 2020 | 32112787 |
| antivenom neutralization of coagulopathic snake venom toxins assessed by bioactivity profiling using nanofractionation analytics. | venomous snakebite is one of the world's most lethal neglected tropical diseases. animal-derived antivenoms are the only standardized specific therapies currently available for treating snakebite envenoming, but due to venom variation, often this treatment is not effective in counteracting all clinical symptoms caused by the multitude of injected toxins. in this study, the coagulopathic toxicities of venoms from the medically relevant snake species bothropsasper, calloselasmarhodostoma, deinagki ... | 2020 | 31963329 |
| uncapping the n-terminus of a ubiquitous his-tag peptide enhances its cu2+ binding affinity. | metal complexes with an n-terminally free and n-terminally acetylated polyhistidine region of echis ocellatus venom, with an interesting his-rich motif present in numerous metal binding proteins from all kingdoms of life (dhdhdhhhhhhpgssv-nh2 and ac-dhdhdhhhhhhpgssv-nh2) show the role of the free amino group in the thermodynamic enhancement of cu2+, ni2+ and zn2+ binding. in the studied sequences, cu2+ can be coordinated by different sets of imidazole rings, and a 3-10 helix is detected in close ... | 2019 | 31309219 |