| the importance of bites by the saw-scaled or carpet viper (echis carinatus): epidemiological studies in nigeria and a review of the world literature. | the incidence of echis carinatus (saw-scaled or carpet viper) bite and its mortality have been investigated in the nigerian savanna region. a geographical area was defined in which the snake was particularly abundant and bites were frequent. perennial and seasonal fluctuations in incidence and mortality, the circumstances in which bites occurred and the types of people bitten were studied at bambur, zaria, kaltungo and gombe hospitals. peak incidence coincided with the increase in farming during ... | 1976 | 14490 |
| micro-elisa for detecting and assaying snake venom and venom-antibody. | enzyme-linked immunosorbent assay (elisa) can detect venom levels down to 1-5 ng/ml. the assay is specific; no cross-reaction of clinical importance was found in a range of 14 different types of venom. both venom and venom-antibody levels were monitored in mice. specific antibody was detected in human serum more than 2 years after an accidental bite by echis carinatus. elisa should clarify many basic problems of envenoming in man. | 1977 | 71452 |
| bites by the carpet viper in the niger valley. | 60 people who had been bitten by the carpet viper, echis carinatus, were seen in four months at zungeru health centre, in north west nigeria, where snake-bite patients have recently occupied 10% of beds. health statistics greatly underestimate the frequency, morbidity, and mortality of snake bite in the rural tropics and further studies will probably confirm other areas endemic for e. carinatus within its vast distribution zone. regular supplies of effective antivenom are crucial to gain a commu ... | 1979 | 90281 |
| the mechanism of activation of human prothrombin by an activator isolated from dispholidus typus venom. | purified human prothrombin was activated, both in the absence and in the presence of thrombin inhibitors (diisopropylfluorophosphate or hirudin), by a coagulant principle isolated from dispholidus typus venom. the process of activation was monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis. in the absence of thrombin inhibitor, prolonged incubation of prothrombin with the purified venom yielded thrombin, fragment 1 (f 1) and fragment 2 (f 2). in the presence of diisopropylflu ... | 1978 | 102363 |
| complement depletion following envenomation by russell's viper and echis carinatus (saw-scaled viper) in the rhesus monkey. | significant depletion of c3 was observed following administration of lethal and sublethal doses of russell's viper and echis carinatus venom to rhesus monkeys. a sequential study carried out over a period of 3 weeks following sublethal envenomation showed a steady rise in the c3 level from 48 hours onwards. by the 20th day the c3 values had attained the pre-envenomation levels. the extent of depletion of c3 was similar in both russell's viper and e. carinatus envenomation. because of the close i ... | 1977 | 410316 |
| poisoning by bites of the saw-scaled or carpet viper (echis carinatus) in nigeria. | the saw-scaled or carpet viper (echis carinatus) whose range extends from senegal to bengal probably bites and kills more people than any other species of snake. one hundred and fifteen patients with poisoning caused by its bite were studied in the savanna region of nigeria, where victims of this snake may occupy 10 per cent of hospital beds. patients showing no signs of envenoming were excluded. all patients had local swelling at the site of the bite. other features included local blistering (1 ... | 1977 | 866568 |
| preparation of toxoids from the venoms of pakistan species of snakes. (naja naja, vipera russellii and echis carinatus). | | 1977 | 875234 |
| activation of bovine prothrombin by an activator isolated from echis carinatus venom. | | 1976 | 936095 |
| changes of prothrombin assayed by the method using echis carinatus venom in experimental disseminated intravascular coagulation and a clinical case. | | 1976 | 936112 |
| the mechanism of activation of bovine prothrombin by an activator isolated from echis carinatus venon and characterization of the new active intermediates. | bovine prothrombin was activated, in both the absence and presence of dissopropyphosphofluoridate (dep) and benzamidine, by an activator which was highly purified from the venom of echis carinatus (saw-scaled viper, ecv). the process of activation was monitored by sodium dodecysulfate (sds)-polyacrylamide gel electrophoresis, and the reaction products were isolated and chemically characterized. in the absence of the inhibitors, prothrombin yielded two fragments with molecular weights of 28,000 a ... | 1976 | 956136 |
| significance of a prothrombin assay method using echis carinatus venom for diagnostic information in disseminated intravascular coagulation syndrome. | | 1975 | 1060188 |
| prothrombin activation induced by ecarin - a prothrombin converting enzyme from echis carinatus venom. | | 1975 | 1114479 |
| activation of human prothrombin by a procoagulant fraction from the venom of echis carinatus. identification of a high molecular weight intermediate with thrombin activity. | in the presence of a procoagulant fraction (echis carinatus procoagulant) isolated from the venom of the saw-scaled viper echis carinatus sochureki, purified human prothrombin (p1) is completely converted to thrombin. the first step is the removal of an nh2-terminal peptide (f1) representing approximately one-third of the prothrombin molecule. the remaining peptide (p2) is then cleaved by the action of e.c. procoagulant to yield a two-chain, disulfide-bridged protein (p'2) which has the same mol ... | 1975 | 1158898 |
| the effect of several viper venoms on prothrombin padua. | the effect of four viper venoms (oxyuranus scutellatus, notechis scutatus scutatus, echis carinatus, naja nigricollis) on prothrombin padua has been studied. using oxyuranus scutellatus venom and notechis scutatus scutatus venom, prothrombin activity resulted to be moderately decreased similarly to what observed with other one-stage and two-stage methods. on the contrary, using echis carinatus venom a normal level was obtained. no clotting was observed using the naja nigricollis venom, regardles ... | 1975 | 1174715 |
| the effect of ecarin- defibrinating enzyme isolated from echis carinatus - on experimental arterial thrombosis. | | 1975 | 1198548 |
| clot-inducing substances present in snake venoms with particular reference to echis carinatus. | | 1976 | 1265707 |
| control of antivenom treatment in echis carinatus (carpet viper) poisoning. | a study of all the patients treated for echis carinatus bites in a rural mission hospital in northern nigeria in june 1973 showed that not all bleeding during recovery from an echis bite results directly from the action of the venom; thus not all bleeding requires antivenom for treatment. evenomation by echis in west africa is accompanied by incoagulability of the blood. if coagulability is assessed by a simply performed test, also described, on each occasion bleeding is suspected of being due t ... | 1976 | 1265825 |
| inhibition of sendai virus by various snake venom. | viperid, elapid and crotalid snake venoms were screened in vitro for antiviral activity against sendai virus. the hemolysis of 10(8) human erythrocytes in 1 ml, caused by 70 hau of sendai virus, was abolished when the virions were pretreated with 10 ug of the viperid venom of echis coloratus, and was considerably diminished when pretreated with 10 ug of the venom of echis carinatus sochureki, the cobra venoms of naja atra and naja nigricollis nigricollis. these venoms did not affect the erythroc ... | 1992 | 1328790 |
| risk indicators after envenomation in humans by echis coloratus (mid-east saw scaled viper). | to determine the frequency, severity and predictors of bleeding and azotemia after envenomation in humans by echis coloratus, a retrospective survey of 68 cases in israel between 1970 and 1989 was carried out. we used univariate and multivariate analyses of clinical variables on admission for the outcome variables of bleeding, hemoglobin and platelet levels, and blood urea. within hours or days after envenomation, a major bleeding episode occurred in 18% of the victims, a drop in hemoglobin to 1 ... | 1992 | 1595076 |
| immunocytochemical localization of platelets in baboon hepatic sinusoids using monoclonal mouse anti-human platelet glycoprotein iiia following induction of thrombocytopenia. | a commercially available mouse monoclonal antibody to human platelet glycoprotein iiia was used to demonstrate sequestration of platelets in hepatic biopsies obtained from baboons following intravenous infusion of echistatin, a novel fibrinogen receptor antagonist derived from the venom of the snake echis carinatus. biopsies of liver and spleen were taken prior to administration of echistatin. the hepatic biopsies were either snap-frozen in freon-22/liquid nitrogen or fixed in 10% neutral buffer ... | 1992 | 1618650 |
| gene expression in echis carinatus (carpet viper) venom glands following milking. | rna was extracted from the venom glands of echis carinatus at different times after milking, and the temporal pattern and nature of mrna transcribed during venom regeneration was examined by in vitro translation. venom products were immunoprecipitated with e. carinatus venom polyclonal antiserum. maximum transcriptional activity occurred 3 days after milking. electrophoretic analysis of the translation products showed minimal differences in the banding patterns at each time interval. analysis of ... | 1992 | 1626320 |
| a novel enzyme immunoassay for quantitation of rat prothrombin in microsomal subfractions. | an enzyme linked immunoassay (elisa) for quantitation of rat prothrombin, based on a biotin-streptavidin alkaline phosphatase system is described. the assay utilizes rabbit antiserum raised against purified rat prothrombin. the assay was twenty fold more sensitive than a rat prothrombin assay based on amidolytic activity following activation by echis carinatus venom. results obtained with the two assays show good correlation. the elisa is a valuable tool for quantitation of minute amounts of pro ... | 1991 | 1806590 |
| life cycle of hepatozoon mehlhorni sp. nov. in the viper echis carinatus and the mosquito culex pipiens. | hepatozoon mehlhori sp. nov. and its developmental stages from the tissues of the egyptian viper echis carinatus and the mosquito culex pipiens are described. the erythrocytic parasites were differentiated into the small form (trophozoite) measuring 14.5 +/- 0.6 x 4 +/- 0.12 micron and the mature form (gametocyte) measuring 17.2 +/- 1.6 x 5.4 +/- 0.5 micron. merogony took place in the pulmonary endothelial cells and in the parenchyma cells of the liver and spleen of the infected vipers. two type ... | 1991 | 1891449 |
| prevention of canine coronary artery thrombosis with echistatin, a potent inhibitor of platelet aggregation from the venom of the viper, echis carinatus. | a model of acute, platelet-dependent canine coronary artery thrombosis was utilized to assess the antithrombotic effect of a synthetic, rgd-containing 49-residue protein termed echistatin. this protein is derived from the venom of the viper, echis carinatus. in vitro, echistatin inhibited adp (10 microm)-induced platelet aggregation with ic50 values in human and canine platelet-rich plasma of 101 +/- 4 and 127 +/- 32 nm, respectively. in vivo, in the dog, infusion of echistatin for 30 min at 20 ... | 1990 | 2084943 |
| the active site of membrane-bound meizothrombin. a fluorescence determination of its distance from the phospholipid surface and its conformational sensitivity to calcium and factor va. | the distance between the phospholipid surface and the active site of membrane-bound meizothrombin, a derivative of prothrombin, was determined directly using fluorescence energy transfer. the active site of prothrombin was exposed after a single cleavage by echis carinatus protease in the presence of [5-(dimethylamino)-1-naphthalenesulfonyl]glutamylglycylarginyl+ ++ (degr) chloromethyl ketone to yield degr-meizothrombin and thereby minimize secondary proteolysis. when degr-meizothrombin was titr ... | 1990 | 2180944 |
| echistatin is a potent inhibitor of bone resorption in culture. | the venom protein, s-echistatin, originally derived from the saw-scaled viper echis carinatus, was found to be a potent inhibitor of bone resorption by isolated osteoclasts. this arg24-gly25-asp26-(rgd)-containing protein inhibited the excavation of bone slices by rat osteoclasts (ic50 = 0.1 nm). it also inhibited the release of [3h]proline from labeled bone particles by chicken osteoclasts (ic50 = 100 nm). by comparison, the tetrapeptide arg-gly-asp-ser (rgds) inhibited resorption by rat or chi ... | 1990 | 2211834 |
| platelet glycoprotein iib-iiia protein antagonists from snake venoms: evidence for a family of platelet-aggregation inhibitors. | the purification, complete amino acid sequence, and biological activity are described for several homologous snake venom proteins that are platelet glycoprotein (gp) iib-iiia antagonists and potent inhibitors of platelet aggregation. the primary structures of kistrin (from agkistrodon rhodostoma), bitan (from bitis arietans), three isoforms of trigramin (from trimeresusus gramineus), and an isoform of echistatin (from echis carinatus) were determined by automated sequence analysis and fast atom ... | 1990 | 2320569 |
| binding of the snake venom-derived proteins applaggin and echistatin to the arginine-glycine-aspartic acid recognition site(s) on platelet glycoprotein iib.iiia complex inhibits receptor function. | in the present report we describe the platelet-binding characteristics of applaggin and echistatin, potent inhibitors of fibrinogen-dependent platelet aggregation derived from agkistrodon piscivorus piscivorus and echis carinatus snake venoms, respectively. both molecules bound to unstimulated platelets in a specific and saturable manner. at saturation there were 37,100 +/- 3,150 (mean, +/- s.d.) molecules of applaggin and 27,200 +/- 2,816 molecules of echistatin bound/platelet, with dissociatio ... | 1990 | 2365698 |
| monoclonal antibodies against vipera lebetina venom nerve growth factor cross-react with other snake venom nerve growth factors. | nerve growth factor (ngf) was isolated from the venom of vipera lebetina and was purified to homogeneity as judged by sds gel electrophoresis. the biologically active ngf was used to immunize balb/c mouse, and the spleen cells from immunized mouse were fused with mouse pai myeloma cells. forty-seven hybrid cell lines, secreting monoclonal antibodies to v. lebetina ngf, were isolated and nine of them purified from ascitic fluids. the isolated antibodies define two partially overlapping epitopes o ... | 1987 | 2448608 |
| antithrombin iii in echis carinatus envenomation in northern nigeria. | antithrombin iii was evaluated in 21 patients admitted with echis carinatus envenomation. although there was evidence of incoagulability in all patients and elevated fibrin degradation products, mean antithrombin iii levels were found to be significantly greater than in controls. this result suggests that echis carinatus venom (echarin) may bypass the consumption of antithrombin iii molecules. | 1989 | 2496558 |
| preliminary study of an extract from diodia scandens on some toxic effects of echis carinatus venom. | | 1989 | 2601359 |
| snake venoms in science and clinical medicine. 2. applied immunology in snake venom research. | enzyme-linked immunosorbent assay (elisa) is a very important tool for studying both the epidemiology and clinical effects of snake bite in man. for epidemiology elisa depends on the development and persistence of specific humoral venom antibody in previous snake bite victims. in the nigerian savanna 63% of previous bite victims possessed specific venom antibodies against echis carinatus venom; in ecuador, where there is a 5% annual mortality due to snake bite in a population of waorani indians, ... | 1989 | 2617643 |
| treatment of envenomation by echis coloratus (mid-east saw scaled viper): a decision tree. | envenomation by echis coloratus causes a transient hemostatic failure. systemic symptoms, hypotension and evident bleeding are rare, with only one reported fatality. in this paper, we examine the decision to treat victims of echis coloratus by a specific horse antiserum. the decision model considers the mortality of treated and untreated envenomation, and the side effects of antiserum treatment: fatal anaphylaxis, serum sickness and increased risk of death after a possible repeated exposure to h ... | 1989 | 2683230 |
| cross reactivity of mono- and polyvalent antivenoms with viperidae and crotalidae snake venoms. | the lethal, local and defibrinating effects of two african viperidae and four crotalidae were assayed. two commercial antivenoms (behringwerke nord africa and wyeth anticrotalic) and gamma-globulins from hyperimmune rabbit serum were tested for their ability to neutralize the toxic effects of the venoms. cross neutralization of the lethal effect (antiviperidae antivenom against crotalidae venom and vice versa) was evident with behringwerke against crotalidae as well as with wyeth against viperid ... | 1989 | 2815109 |
| 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 |
| chromogenic assay for the prothrombin activator ecarin from the venom of the saw-scaled viper (echis carinatus). | ecarin, by limited proteolysis and subsequent autocatalytic reactions, causes the conversion of prothrombin into three products with amidolytic activity: meizothrombin, meizothrombin 1 and lpha-thrombin. ecarin action may be abolished by ethylenediaminetetraacetic acid and the activity of alpha-thrombin can, with a high degree of selectivity, be inhibited by heparin. thus, ecarin potency may be assayed by measuring the meizothrombin activity generated by ecarin action on human plasma in the pres ... | 1986 | 3082039 |
| disseminated intravascular coagulation following echis carinatus venom in dogs: effects of a synthetic thrombin inhibitor. | disseminated intravascular coagulation (dic) was produced by an infusion of a prothrombin activator (echis carinatus venom; 30 minutes; 0.5 nih thrombin equivalent u/kg) in mongrel dogs (echis group, n = 7). fibrinogen declined to below measurable levels (less than 25 mg/dl), and fibrin-fibrinogen degradation products appeared (53 +/- 8 micrograms/ml) at end venom infusion in the echis group. these alterations were not seen when an irreversible thrombin inhibitor, d-phenylalanyl-l-prolyl-l-argin ... | 1986 | 3086470 |
| prothrombin segovia: a new congenital abnormality of prothrombin. | a family with a new congenital dysprothrombinemia is presented. the propositus is a 21-yr-old man who presented simultaneously with hemartrosis of the left knee and an extensive hematoma following a minor trauma. prothrombin time and activated partial thromboplastin time were prolonged. prothrombin activity was very low when measured by biological assay using physiological activators (7% by one-stage method and 20% by two-stage method) or a russel's viper venom-cephalin mixture (23%), notechis s ... | 1986 | 3090681 |
| echistatin. a potent platelet aggregation inhibitor from the venom of the viper, echis carinatus. | a 49-residue protein, echistatin, which inhibits platelet aggregation, was purified from the venom of the saw-scaled viper echis carinatus. the purification procedure included gel filtration on sephadex g-50, cation-exchange chromatography on mono s, and c18 reverse-phase high pressure liquid chromatography. the purified protein was homogeneous as judged by polyacrylamide gel electrophoresis, isoelectric focusing, reverse-phase high pressure liquid chromatography, and nh2-terminal sequence analy ... | 1988 | 3198653 |
| characterisation of a monoclonal antibody capable of neutralising the haemorrhagic activity of west african echis carinatus (carpet viper) venom. | a murine monoclonal antibody (sv-1/f10) was highly specific immunologically for west african e.carinatus venom both by elisa and immunoblotting. in cross-protection tests in vivo, it possessed strong antihaemorrhagic activity. this iggl monoclonal antibody recognised an epitope present in a protein band of 124,000 mol. wt using immunoblotting of non-reduced nigerian and ghanaian e.carinatus venoms, as well as in a second protein band of 105,000 mol. wt in ghanaian e.carinatus venom. the sv-1/f10 ... | 1988 | 3284002 |
| pulmonary fibrin deposition and increased microvascular permeability to protein following fibrin microembolism in dogs: a structure-function relationship. | the effects of fibrin microembolism were examined using an infusion of a prothrombin activator (echis carinatus venom, ecv; 30 min, 0.5 nih thrombin equivalent units/kg) in acute mongrel dogs prepared with a pulmonary lymph cannula (n = 6, 12.3-21.5 kg). lymph flow increased approximately 2.5-fold after 1-1.5 hr of elevated left atrial pressure (pla = 20 cm h2o; 26 +/- 7 to 63 +/- 16 microliter/min, p less than 0.01) and the plasma to lymph protein concentration ratio (cp/cl) declined from 0.66 ... | 1987 | 3302621 |
| platelet procoagulant properties studied with snake venom prothrombin activators. | purified snake venom prothrombin activators were used to probe the procoagulant properties of platelet membranes. human platelets were able to stimulate prothrombin activation by the venom activators from oxyuranus scutellatus and notechis scutatus, while the prothrombin activator from echis carinatus was not affected by the presence of platelets. the prothrombin-converting activity of platelets was further studied with the venom activator from oxyuranus scutellatus and with the factor xa-va com ... | 1987 | 3310319 |
| on the quantification of prothrombin from different species using echis carinatus as activator. | the generation of thrombin-like activity from rat, human, bovine and mouse prothrombin by echis carinatus venom (ecv) treatment was compared using a partially purified system (i.e. whole ecv and isolated prothrombin). a rapid increase in coagulant activity was obtained within 0.5 to 2 min., being constant upon further incubation for 60 min. a large variation in coagulant activity of the ecv generated thrombin from the four species was found, whereas no differences were found for the amidolytic a ... | 1986 | 3523815 |
| an investigation of venom secretion by the venom gland cells of the carpet viper (echis carinatus). | the indirect immunofluorescent antibody technique was applied to the study of echis carinatus pyramidum venom antigens in venom gland tissue using semi-thin frozen sections. a total of four rabbit antisera, two monoclonal antibodies active against e. carinatus venom, two monoclonal antibodies active against the rodent malaria parasite, plasmodium chabaudi, and two monoclonal antibodies active against the human malaria parasite, plasmodium falciparum, were investigated. the results of this study ... | 1986 | 3535168 |
| proteolysis of bovine and human prothrombin and of bovine factor x by rat mast cell proteinase. | the alpha-chymotrypsin-like proteinase from rat peritoneal mast cells (rmcp i) rapidly destroyed the normal clotting activity of purified, calcium-free, bovine prothrombin, human prothrombin and bovine factor x and simultaneously removed similar n-terminal peptides (mr approximately 5,000) from both prothrombin and the 'light' chain of factor x. the amino acid composition of the peptides agreed with the known composition of the regions of the respective parent molecules where gamma-carboxyglutam ... | 1986 | 3541280 |
| blood coagulation induced by the venom of bothrops atrox. 1. identification, purification, and properties of a prothrombin activator. | in this paper, we show that the procoagulant action of bothrops atrox venom is due in part to a protein component that activates prothrombin. the venom prothrombin activator was purified by ion-exchange chromatography and gel filtration. it was separated from a protease by affinity chromatography in a p-aminobenzamidine-ch-sepharose column. it is a protein of about mr 70,000, consisting of a single polypeptide chain. we have studied the kinetics of activation of prothrombin under different exper ... | 1987 | 3552031 |
| prothrombin poissy: a new variant of human prothrombin. | a new congenital dysprothrombinaemia is described in a newborn baby girl who presented severe bleeding from the second day of life. routine coagulation tests showed very prolonged prothrombin time and activated partial thromboplastin time with about 2% prothrombin activity in a one-stage assay. staphylocoagulase and echis carinatus venom prothrombin assays were respectively 35% and 25%. the prothrombin antigen level was 47% and its migration in crossed immuno-electrophoresis was abnormal. family ... | 1987 | 3606959 |
| structural and functional characterization of a prothrombin activator from the venom of bothrops neuwiedi. | a prothrombin activator from the venom of bothrops neuwiedi was purified by gel filtration on sephadex g-100, ion-exchange chromatography on deae-sephacel and affinity chromatography on a zn2+-chelate column. the overall purification was about 200-fold, which indicates that the prothrombin activator comprises about 0.5% of the crude venom. the venom activator is a single-chain protein with an apparent molecular weight of 60 kda. it readily activated bovine prothrombin with a km of 38 microm and ... | 1987 | 3689799 |
| effect of venom from bitis nasicornis (rhinoceros horned viper) on isolated rabbit aortic strips. | venom from b. nasicornis, but not from bitis arietans, echis carinatus or cerastes cerastes, produced an irreversible contraction of the isolated aortic strip that was slow in onset, increased with time, and reached maximum in about 10-15 min. the contraction was not inhibited by pretreatment with atropine, yohimbine, phentolamine, cyproheptadine or indomethacin, however, it was blocked by incubation in a ca2+-free solution and was partially blocked by incubation with the ca2+ channel blockers v ... | 1986 | 3715900 |
| heparin-enhanced inhibitors during reversible disseminated intravascular coagulation. | intravenous injection of homologous lung or brain tissue thromboplastin in dogs under general anesthesia induced changes of conventional hemostasis variables consistent with acute dic (prolongation of prothrombin times, thrombin times, aptt, drop of fibrinogen and a transient reduction of the platelet count). the animals reacted with accelerated respiration and pulse rates. after recovery from anesthesia they resumed their normal activity as before. fibrinogen reached a minimum within 40 min aft ... | 1985 | 3867125 |
| modification of histidines in human prothrombin. effect on the interaction of fibrinogen with thrombin from diethyl pyrocarbonate-modified prothrombin. | diethyl pyrocarbonate (ethoxyformic anhydride) was used to modify histidyl residues in prothrombin. diethyl pyrocarbonate inactivated the potential fibrinogen-clotting activity of prothrombin with a second-order rate constant of 70 m-1 min-1 at ph 6.0 and 25 degrees c. the difference spectrum of the modified protein had a maximum absorption at 240 nm which is characteristic of n-carbethoxyhistidine. the ph dependence for inactivation suggested the participation of a residue with a pka of 6.2. ad ... | 1985 | 3886645 |
| action mechanism of the platelet aggregation inducer and inhibitor from echis carinatus snake venom. | platelet aggregation inducer and inhibitor were isolated from echis carinatus snake venom. the venom inducer caused aggregation of washed rabbit platelets which could be inhibited completely by heparin or hirudin. the venom inducer also inhibited both the reversibility of platelet aggregation induced by adp and the disaggregating effect of prostaglandin e1 on the aggregation induced by collagen in the presence of a23187, arachidonate, adp and platelet-activating factor (paf) with an ic50 of arou ... | 1985 | 3926005 |
| characterization of the platelet aggregation inducer and inhibitor from echis carinatus snake venom. | echis carinatus venom was separated into twenty fractions by means of ultrafiltration and cm-sephadex c-50 column chromatography. fraction ii possessed inhibitory activity on the aggregation of washed rabbit platelets and fraction xii possessed the procoagulant and platelet aggregation-inducing activity. both were further purified by gel filtration on a sephacryl s-200 column. the purified aggregation inducer was a glycoprotein with procoagulant activity 10-12-times that of the crude venom. it p ... | 1985 | 4016143 |
| liposomal immunisation against snake venoms. | a method is described which produces a high, permanent antibody response following a single injection of venom. animals (mice, rabbits, sheep) were given intravenous, subcutaneous or orally administered nigerian echis carinatus (carpet viper) venom which had been incorporated into sphingomyelin-cholesterol liposomes whose membranes had been stabilized by cross-linking adjacent molecules of sphingomyelin using osmium tetroxide. before use the preparations were thoroughly dialysed to remove any un ... | 1985 | 4024133 |
| use of liposomes for protective immunisation in sheep against echis carinatus snake venom. | nigerian echis carinatus venom incorporated into sphingomyelin-cholesterol liposomes stabilized with osmium tetroxide produced a rapid, sustained and protective immune response when injected i.v. into sheep. the response was similar to that reported earlier in mice. the implications of the findings are discussed in relation to the production of cheaper and more effective antivenoms. the possible use of immunostimulants for increasing the protective effect of antisera raised using this method are ... | 1985 | 4095707 |
| a prolonged defibrination caused by echis carinatus venom. | | 1971 | 4102309 |
| bites by the saw-scaled or carpet viper (echis carinatus): trial of two specific antivenoms. | echis carinatus is the most important cause of morbidity and mortality from snake bite in nigeria and in many other parts of the world. forty-six patients with systemic poisoning by this snake were given echis antivenom made either by the south african institute for medical research (s.a.i.m.r.) or by behringwerke (north and west african polyvalent antivenom). a simple test of blood coagulability was used to assess whether an adequate neutralizing dose of antivenom had been given. an average of ... | 1974 | 4154124 |
| effects of echis carinatus venom on tissue and blood histamine and their relations to local tissue reactions and eosinophil changes. | | 1968 | 4179719 |
| lesions produced by echis carinatus venom in experimental animals. | | 1974 | 4212122 |
| isolation, biochemical and pharmacologic characterization of a prothrombin-activating principle from echis carinatus venom. | | 1969 | 4242406 |
| the prothrombin-activating principle from echis carinatus venom. ii. coagulation studies in vitro and in vivo. | | 1972 | 4262727 |
| thrombocytopenia in defibrination syndrom induced by echis carinatus venom coagulase. | | 1972 | 4670751 |
| mechanism of action of vitamin k: demonstration of a liver precursor of prothrombin. | extracts of sonicated liver microsomes that are prepared from rats deficient in vitamin k or from rats given vitamin k antagonists contain a factor that liberates a thrombin-like activity when it is incubated with venom from echis carinatus. the amount of this factor is low in control rats and in hypoprothrombinemic rats given vitamin k 1 hour before they were killed. these data indicate that this factor is a protein precursor of prothrombin, which is synthesized in the liver. | 1973 | 4682251 |
| [comparison of the principal pharmacologic properties of different venoms of echis carinatus (viperides)]. | | 1973 | 4766551 |
| [neuromuscular action of an echis carinatus (viperidae) venom from ethiopia]. | | 1971 | 5160342 |
| observations on the effects of echis carinatus venom on blood clotting. | | 1969 | 5776835 |
| incidence and mortality on snake bite in savanna nigeria. | snake bite is a major medical problem among farming communities in the benue and niger valley savanna region of nigeria. surveys in the more densely populated northern savanna areas such as malumfashi (incidence 48 per 100 000 population, mortality 5.1%) show that the spitting cobra, naja nigricollis, was the predominant species of medical importance. in the less cultivated benue valley area the annual snake-bite incidence was estimated to be 497 per 100 000 population, with a 12.2% mortality du ... | 1980 | 6107780 |
| the action of prothrombin activated by ecarin on fibrinogen. | highly purified human prothrombin was activated by ecarin, a prothrombin activating principle of echis carinatus venom and the generated thrombin-like activity was investigated. kinetics of the release of fibrino-peptides a and b (fpa, fpb) from human fibrinogen was estimated using radioimmunoassay technique. the direct proteolytic action of ecarin on fibrinogen was studied by means of polyacrylamide gel electrophoresis and by radioimmunoassay for fragment b beta 15-42 of fibrinogen. in a system ... | 1983 | 6346578 |
| prothrombin salakta: an abnormal prothrombin characterized by a defect in the active site of thrombin. | an abnormal prothrombin has been detected in a 17 yr-old female originating from tunisia. there was no history of excessive bleeding. prothrombin time and activated partial thromboplastin time were moderately prolonged. prothrombin activity was 15-18% when measured using either the classical one-stage and two-stage assays, or assays with echis carinatus venom or staphylocoagulase, whereas prothrombin antigen was 100%. in keeping with current nomenclature practices, the abnormal molecule has been ... | 1984 | 6377575 |
| a sensitive colorimetric assay for thrombin, prothrombin and antithrombin iii in human plasma using a new synthetic substrate. | benzoyl-l-leucyl-l-alanyl-l-arginine-alpha-naphthylester (bz-leu-ala-arg-ne) was synthesized as a new substrate for use in the assay of thrombin. in the assay alpha-naphthol released by the enzyme reaction was measured colorimetrically. with bz-leu-ala-arg-ne as substrate, the minimum detectable concentration of human thrombin was 0.0025 u. this assay using bz-leu-ala-arg-ne is a highly sensitive method for detecting prothrombin, thrombin and antithrombin iii in human plasma. prothrombin could b ... | 1982 | 6461438 |
| pulmonary fibrin microembolism with echis carinatus venom in dogs: effects of a synthetic thrombin inhibitor. | we produced pulmonary fibrin microembolism using an infusion of a prothrombin activator (echis carinatus venom, 30 min, 0.5 nih thrombin equivalent units/kg) in open-chest mongrel dogs. to determine the nonclotting effects of this venom on edemagenesis we infused an irreversible thrombin inhibitor, d-phenylalanyl-l-prolyl-l-arginine chloromethyl ketone (ppack, 57 nmol x kg-1 x min-1 for 120 min), alone (n = 5) or with venom (echis + ppack, n = 5). the control group (n = 5) was given 1 ml of 0.9% ... | 1984 | 6511556 |
| development of simple standard assay procedures for the characterization of snake venom. | in accordance with the recommendations of the report of a who coordination meeting on venoms and antivenoms, methods have been developed for the assessment of lethal, defibrinogenating, procoagulant, haemorrhagic, and necrotizing properties of venoms, and used to study 53 venoms from 30 different species of snakes of medical importance throughout the world. the venoms studied included echis carinatus (iran), naja naja kaouthia (thailand), notechis scutatus (australia), trimeresurus flavoviridis ... | 1983 | 6609011 |
| cleavage and activation of human prothrombin by echis carinatus venom. | the cleavage of human prothrombin by partially purified echis carinatus venom (ecv) was investigated in the present report. incubation of prothrombin with ecv resulted in the rapid cleavage of prothrombin to alpha-thrombin, with the release of fragment-1 and fragment-2. when dansyl arginine-n-(3-ethyl-1,5-pentanediyl) amide (dapa), a very effective inhibitor of thrombin, was included in the ecv-prothrombin solution, meizothrombin was rapidly formed. only small amounts of meizothrombin-1 could be ... | 1982 | 6758184 |
| factor ii antigen in liver disease and warfarin-induced vitamin k deficiency: correlation with coagulant activity using echis venom. | four coagulation factors (ii, vii, ix, x) are synthesized in the liver as precursor forms. vitamin k is necessary for their conversion to functional factors. factor ii precursor is antigenically similar to factor ii and can be activated to form thrombin by echis carinatus venom. forty-one patients with liver disease and 30 patients with vitamin k deficiency (warfarin treated), were compared with 51 normal patients. rats with ccl4-induced hepatic necrosis and animals given warfarin were also stud ... | 1980 | 6774611 |
| determination of prothrombin by a micro-coagulation method. | in contrast to earlier assays, the prothrombin determination described here uses a two-step reaction: first, prothrombin is activated with human factor xa, phospholipids, ca++ and factor v; second, the amount of activated prothrombin is assayed by the proteolysis of added fibrinogen. the assay is dependent only on prothrombin, and independent of other components of thrombin generation. carboxy- and decarboxyprothrombin can be differentiated by means of using echis carinatus venom instead of fact ... | 1983 | 6840624 |
| the effect of vitamin e on warfarin-induced vitamin k deficiency. | vitamin k-deficient animals and humans developed a more severe coagulopathy when treated with vitamin e, which was due to further reduction in the vitamin k-dependent coagulation factors (ii, vii, ix, and x). this phenomenon was not seen in normal vitamin k-sufficient animals or human subjects. the mechanism by which vitamin e causes this effect is not known. these coagulation factors are produced by the liver in precursor forms and are converted to functional proteins by a vitamin k-dependent r ... | 1982 | 6959563 |
| enzyme-linked immunosorbent assay of venom-antibodies in human victims of snake bite. | the development, incidence, persistence, and significance of specific venom-antibodies were studied in 357 human victims of snake bite in nigeria using the enzyme-linked immunosorbent assay (elisa). venom-antibody was not detected within 2 weeks of envenoming but was present within 2 months of the bite despite therapeutic antivenom being given. elisa confirmed the medical importance of the carpet viper echis carinatus in nigeria but also showed that bites by other venomous species are more commo ... | 1981 | 7241624 |
| hemostatic abnormalities following echis carinatus (saw-scaled viper) envenomation in the rhesus monkey. | hemostatic abnormalities following lethal and sublethal doses of echis carinatus venom were studied in a subhuman primate model. the observations suggest the occurrence of disseminated intravascular coagulation of varying magnitude within a few hours of envenomation. a procoagulant effect of the venom of echis carinatus is likely to be the major cause of the disturbance in the hemostatic mechanism. | 1981 | 7283009 |
| prothrombin houston: a dysprothrombin identifiable by crossed immunoelectrofocusing and abnormal echis carinatus venom activation. | a 72-yr-old male with a lifelong history of easy bruisability and posttraumatic bleeding had a prolonged prothrombin time and activated partial thromboplastin time. his plasma stypven, taipan, and echis carinatus venom clotting times were prolonged. the presence of a dysprothrombin was confirmed by the discrepancy between plasma prothrombin coagulant activity and prothrombin antigen levels. his plasma prothrombin was capable of being completely absorbed onto and then eluted from barium sulfate. ... | 1980 | 7362870 |
| comparison of pasteur and behringwerke antivenoms in envenoming by the carpet viper (echis carinatus). | bites and envenoming by the carpet viper echis carinatus are common medical emergencies in parts of nigeria, but the most effective use of the various commercially produced antivenoms in treatment has not been established. pasteur paris echis monospecific and behringwerke west and north africa bitis-echis-naja polyspecific antivenoms were compared in two groups of seven patients with incoagulable blood after e carinatus bites. in both groups spontaneous bleeding stopped within a few hours and lo ... | 1980 | 7370603 |
| echistatin inhibits the adhesion of murine melanoma cells to extracellular matrix components. | echistatin, an rgd containing peptide isolated from echis carinatus snake venom, inhibited the in vitro attachment of b16-bl6 mouse melanoma cells to fibronectin, vitronectin and laminin. its inhibitory activity on cell adhesion was non-cytotoxic, dose-dependent and fully reversible. kinetic analysis showed a competitive type of inhibition for all the three substrates examined here. chemical reduction and alkylation of echistatin almost abolished its effect on cell adhesion to extracellular matr ... | 1995 | 7735124 |
| expression and folding of recombinant bovine prethrombin-2 and its activation to thrombin. | bovine prethrombin-2 has been produced in escherichia coli using a t7 expression system. the expressed prethrombin-2 formed intracellular inclusion bodies which were solubilized by reversible sulfonation of the cysteines in the presence of 7 m guanidine hydrochloride. sulfonated prethrombin-2 was refolded in the presence of 4 m guanidine hydrochloride, using oxidized and reduced glutathione as the redox couple. the folded protein was purified by heparin affinity chromatography and activated to t ... | 1995 | 7814368 |
| determination of the structure of two novel echistatin variants and comparison of the ability of echistatin variants to inhibit aggregation of platelets from different species. | two new variants of short disintegrins were purified from the venom of echis carinatus leakeyi and named echistatin beta and gamma. these proteins were found to be about 85% similar in amino acid sequence to echistatin alpha which has been well studied. the disulphide pattern of echistatin gamma appeared to be identical with that of echistatin alpha. they all contain the adhesive recognition sequence arg-gly-asp (rgd) but inhibit the aggregation of platelets from human and other mammals with dif ... | 1995 | 7832768 |
| purification of a basic phospholipase a2 from indian saw-scaled viper (echis carinatus) venom: characterization of antigenic, catalytic and pharmacological properties. | a major basic phospholipase a2 was purified from the indian saw-scaled viper (echis carinatus) venom by the combination of column chromatography and electrophoresis. the purified phospholipase a2 (ec-iv-pla2) has a mol. wt of 14,000 by sds-page. it is a basic protein with a pi value between 7.2 and 7.6, and has a fluorescence emission maxima at 340 nm. it induces neurotoxicity and oedema in mice with an i.p. ld50 of 5 mg/kg body weight. it is devoid of direct haemolytic, myotoxic, cytotoxic and ... | 1994 | 7846689 |
| cdna cloning and deduced amino acid sequence of prothrombin activator (ecarin) from kenyan echis carinatus venom. | the complete amino acid sequence of ecarin is deduced from the nucleotide sequence of a cdna clone isolated by screening a venomous gland cdna library of kenyan echis carinatus. the cdna sequence with 2379 base pairs encodes an open reading frame of 616 amino acids with a remarkable sequence homology to the putative precursor protein of trigramin from trimeresurus gramineus venom (61% identity) and a large hemorrhagin, jararhagin, from the pit viper bothrops jararaca venom (62% identity). thus, ... | 1995 | 7849037 |
| neurotoxicity, haemostatic disturbances and haemolytic anaemia after a bite by a tunisian saw-scaled or carpet viper (echis 'pyramidum'-complex): failure of antivenom treatment. | a young man in germany was bitten by a large captive saw-scaled viper (echis 'pyramidum'-complex) of tunisian origin. during the first few hours after the bite he developed evidence of disseminated intravascular coagulation and fibrinolysis, and bled spontaneously. despite being given a total of 310 ml of three different echis-specific antivenoms (together with large amounts of fresh frozen plasma and concentrated clotting factors), venom antigenaemia (measured by enzyme immunoassay) and coagulo ... | 1994 | 7985198 |
| isolation, characterization and amino acid sequence of echicetin beta subunit, a specific inhibitor of von willebrand factor and thrombin interaction with glycoprotein ib. | echicetin is a dimeric protein isolated from the venom of echis carinatus that is a potent inhibitor of von willebrand factor and thrombin binding to glycoprotein ib. here, we report isolation and amino acid sequence of the beta subunit of echicetin that contains 123 amino acids, including 7 cysteines, and shows similarity with amino acid sequences of botrocetin and factor ixa/xa binding protein. we provide evidence that biological activity of echicetin which resides in this beta subunit is rela ... | 1994 | 7999097 |
| screening of snake venoms for neurotoxic and myotoxic effects using simple in vitro preparations from rodents and chicks. | eight snake venoms designated by the who as international reference venoms, and one additional venom were assessed for neurotoxic and myotoxic effects in vitro using the chick biventer cervicis and the rat and mouse phrenic nerve-diaphragm preparations. the objective was to determine whether any of the preparations could be used to detect evidence of neurotoxic or myotoxic activity prior to a more detailed examination. bungarus multicinctus venom at concentrations above 1 microgram ml-1 selectiv ... | 1994 | 8016848 |
| the use of the chick biventer cervicis preparation to assess the protective activity of six international reference antivenoms on the neuromuscular effects of snake venoms in vitro. | the protective activity of some antivenoms on the neuromuscular activity in vitro of six snake venoms was established in order to test the feasibility of using a simple isolated nerve-muscle preparation to compare different antivenoms. six venoms designated as international reference venoms by the world health organization (who) were used: echis carinatus (iran), echis carinatus (mali), naja naja kaouthia, notechis scutatus, trimeresurus flavoviridis, and vipera russelli (thailand). the chick bi ... | 1994 | 8016849 |
| [the ability of low-molecular heparin (fraxiparin) to overcome the action of exogenous coagulases--a fundamental difference from nonfractionated heparin]. | a new previously unknown activity of the low molecular-weight heparin fraxiparin (sanofi) has been discovered. this is its ability to reduce the plasma clotting action of snake venom coagulases at final concentration of more than 12.5 anti-xa u/ml, while the unfractionated heparin does not possess this property. the experiments demonstrated that fraxiparin the action of echis carinatus prothrombin-activating venom to a greater degree and agkistrodon halys halys thrombin-like coagulase to a lesse ... | 1993 | 8117966 |
| echicetin: a snake venom protein that inhibits binding of von willebrand factor and alboaggregins to platelet glycoprotein ib. | echicetin, a new protein isolated from echis carinatus venom by reverse phase and ion exchange chromatography specifically inhibited agglutination of fixed platelets induced by several platelet glycoprotein ib (gpib) agonists, such as bovine von willebrand factor (vwf), alboaggregins, and human vwf in the presence of botrocetin. unlike alboaggregins, echicetin bound to gpib but did not induce agglutination of washed or fixed platelets. in contrast to disintegrins, it did not block adenosine 5'-d ... | 1993 | 8481512 |
| inhibition of retinal pigment epithelial cell-induced tractional retinal detachment by disintegrins, a group of arg-gly-asp-containing peptides from viper venom. | integrin-mediated extracellular matrix (ecm) attachment plays an important role in vitreous contraction of retinal pigment epithelial (rpe) cells. disintegrins, a group of arg-gly-asp (rgd)-containing peptides from viper venom, are potential anti-adhesion agents that interfere with integrin-ecm binding. this study was performed to determine whether disintegrins were effective in inhibiting rpe cell-induced matrix attachment in vitro and tractional retinal detachment in a rabbit model in vivo. | 1996 | 8603869 |
| the role of the insertion loop around tryptophan 148 in tthe activity of thrombin. | thrombin has trypsin-like specificity for arg-xaa and lys-xaa peptide bonds; however, it is much more specific than trypsin, cleaving far fewer peptide bonds in macromolecular substrates. to probe the nature of the specificity of thrombin, a mutant has been constructed in which the trp148 loop of thrombin has been replaced with the same loop of bovine trypsin. this mutant was expressed in escherichia coli as prethrombin-2(148) using a t7 expression system previously described for wild-type preth ... | 1996 | 8605192 |
| functional and sequence characterization of coagulation factor ix/factor x-binding protein from the venom of echis carinatus leucogaster. | a new coagulation factor ix/factor x-binding protein (ix/x-bp) from echis carinatus leucogaster venom has been purified and designated eclv ix/x-bp. eclv ix/x-bp binds factor ix and x in a ca(2+)-dependent manner and is devoid of thrombin-inhibitory and platelet-aggregating activities. the apparent dissociation constants (kd) for binding of eclv ix/x-bp to factor ix and factor x are 6.6 and 125 nm, respectively. upon the addition of mg2+, the required ca2+ concentration for optimal binding of ec ... | 1996 | 8611513 |
| rational design, recombinant preparation, and in vitro and in vivo characterization of human prothrombin-derived hirudin antagonists. | a mutant derivative of human prothrombin in which active site aspartate at position 419 is replaced by an asparagine (d419n-prothrombin) has been designed, expressed in recombinant chinese hamster ovary cells, and purified to homogeneity. d419n-prothrombin was converted to the related molecules d419n-meizothrombin and d419n-thrombin by limited proteolysis by echis carinatus and oxyuranus scutellatus venom protease, respectively, and affinity-purified using an immobilized modified c-terminal hiru ... | 1996 | 8798598 |
| asp-49 is not an absolute prerequisite for the enzymic activity of low-m(r) phospholipases a2: purification, characterization and computer modelling of an enzymically active ser-49 phospholipase a2, ecarpholin s, from the venom of echis carinatus sochureki (saw-scaled viper). | several studies have shown that asp-49 is the residue that controls calcium binding in, and so plays a critical role in the calcium-mediated activation of, low-m(r) group i-iii phospholipases a2 (pla2s). the present paper provides experimental evidence that asp-49 is not an absolute prerequisite for the enzymic activity of pla2s, and that proteins with amino acid(s) other than asp at position 49 can exhibit significant phospholipase activity. the purification, complete amino acid sequence and ch ... | 1996 | 8921006 |
| differentiation between proteolytic activation and autocatalytic conversion of human prothrombin. activation of recombinant human prothrombin and recombinant d419n-prothrombin by snake venoms from echis carinatus and oxyuranus scutellatus. | recombinant human prothrombin (r-prothrombin) and recombinant mutant prothrombin with active site asp419 substituted by asn (d419n-prothrombin) were expressed in recombinant cho cells, isolated and purified from the fermentation supernatant. the r-prothrombin and d419n-prothrombin were digested by both echis carinatus venom and oxyuranus scutellatus venom. prior to, during and after activation, generation of thrombin activity and the proteolytic degradation of the prothrombin polypeptide chain w ... | 1996 | 8931132 |
| a rapid and highly sensitive chromogenic microplate assay for quantification of rat and human prothrombin. | a rapid and highly sensitive chromogenic microplate assay for quantification of rat and human prothrombin in subcellular fractions and large series of plasma samples has been developed. the assay is based on the conversion of prothrombin to thrombin, using echis carinatus venom as an activator, and the subsequent cleavage of a chromogenic thrombin specific substrate, d-cyclohexylglycyl-l-alanyl-l-arginine-p-nitroanilide dihydroacetate. para-nitroaniline being released by the cleavage is then mea ... | 1997 | 9056216 |
| partially purified echis carinatus venom cleaves active-site-mutated bovine prothrombin at two sites. | partially purified snake venom of echis carinatus (ecv) is a well-known enzyme used to generate meizothrombin from prothrombin. in this reaction, meizothrombin is slowly converted to two smaller fragments. it is not certain if this slow reaction is catalyzed by meizothrombin or by ecv. using previously constructed active site mutant bovine prothrombin, we eliminated meizothrombin autolysis and examined ecv reactions. ecv did slowly generate two fragments during activation of the active site muta ... | 1997 | 9076894 |
| purification and characterization of a variant of human prothrombin: prothrombin segovia. | a dysprothrombin designated prothrombin segovia was isolated from the plasma of an individual with normal prothrombin antigen and prothrombin activity lesser than 25% of the control prothrombin activity. activation by prothrombinase complex showed a lower amidolytic than clotting activity, which suggests a lesser generation of active intermediates than normal prothrombin. when prothrombin segovia was activated by prothrombinase complex in the absence of factor va, no thrombin formation was found ... | 1997 | 9101639 |