| in vivo thrombus formation induced by complement activation on polymer surfaces. | to clarify involvement of complement activation in thrombus formation on polymer surfaces, in vitro complement activation was evaluated for polyethylene (pe) tubes radiation-graft copolymerized with acrylamide (aam), acrylic acid (ac), 2-hydroxyethyl methacrylate (hema), n-vinylpyrrolidone (nvp), and vinyl alcohol (voh), and compared to their in vivo antithrombogenicity and cell adherence in canine peripheral veins. the complement-activating surfaces (nvp and voh) cause preferential adhesion of ... | 1990 | 2283355 |
| reduction of total hemolytic complement activity with naja haje cobra venom factor does not prevent endotoxin-induced lung injury in sheep. | we studied the effects of reducing total hemolytic complement activity with naja haje cobra venom factor on the lung injury caused by intravenously infused endotoxin in 5 unanesthetized sheep with lung lymph fistulas. in normal sheep, infusions of lipopolysaccharide w from escherichia coli (1.0 micrograms/kg) intravenously over 30 min caused increases in protein-rich lung lymph flow as well as the appearance in plasma and lung lymph of complement (c5)-derived chemotactic activity for polymorphon ... | 1986 | 3510582 |
| effects of naja haje (egyptian cobra), naja naja (hooded cobra), naja nigricollis (spitting cobra) and naja mossambica mossambica (mozambique spitting cobra) venoms on the isolated guinea-pig tracheal muscle. | venoms from n. haje, n. naja, n. nigricollis and n. mossambica were tested on the isolated guinea-pig trachea. the four venoms (1-30 micrograms/ml) contracted the tracheal smooth muscle after a delay of 40-60 sec. a second challenge with the venoms caused either no or a much reduced contraction or a relaxant effect. the contraction could be prevented by pretreatment with antihistaminics, but not by atropine, methysergide or indomethacin, indicating that it is due to histamine release by the veno ... | 1986 | 3564065 |
| properties of some 3-nitrotyrosyl elapid venom cardiotoxins. | nitration of the invariant tyr-22 in hemachatus haemachates cardiotoxin 12b did not greatly decrease lethality, and the haemolytic potency towards guinea-pig erythrocytes remained unchanged. this residue is thus non-essential for cardiotoxin to exert its biological action. nitration of naja haje annulifera and naja melanoleuca cardiotoxins vii1 decreased but did not abolish the lethalities and haemolytic potencies. thus tyr-25 and tyr-51 were concluded to have no direct functional role in cardio ... | 1987 | 3569641 |
| effect of cobra venom (naja haje) on insulin release by rat pancreas in vitro. | | 1974 | 4376284 |
| ionophoretic fractionation of naja haje venom. | | 1971 | 4997189 |
| the effects of naja haje venom and its ionophoretic fractions on glucose metabolism. | | 1972 | 5015538 |
| effects of cobra (naja haje) venom on blood glucose, blood phosphate and plasma insulin-like activity in dogs. | | 1972 | 5070577 |
| acid and alkaline phosphomonoesterases in egyptian snake venoms. | non-specific acid and alkaline phosphomonoesterases could be demonstrated in two viperids (cerastes cerastes and cerastes vipers) and two elapids (naja haje and naja nigricollis). the latter could be a natural source for the production of these enzymes. the activities of both enzymes in elapids were greater than in viperids. n. nigricollis was the only to show acid phosphatase activity exceeding its alkaline one. the optimum ph values recorded for acid phosphatase was 4.0 and 4.9 and for alkalin ... | 1981 | 6264698 |
| structure-activity studies of homologues of short chain neurotoxins from elapid snake venoms. | three neurotoxin homologues (cm10 and cm12 from naja haje annulifera and s5c10 from dendroaspis jamesoni kaimosae) and two short neurotoxins (cm14 from naja haje annulifera and erabutoxin b from laticauda semifasciata) were examined by circular dichroism (c.d.) and tested for neuromuscular activity on chick biventer cervicis nerve-muscle preparations. all three homologues had acetylcholine receptor blocking activity, as they abolished responses to indirect stimulation, acetylcholine and carbacho ... | 1984 | 6743920 |
| isolation and properties of a complement inhibitor from naja haje venom, distinct from known anticomplementary factors in cobra venom. | a complement inhibitor (ci) has been isolated from cobra (naja haje) venom which is distinct from the two known anticomplementary factors in cobra venom [1], in functional properties as well as structure. ci is a small (mol. wt 26,000, determined by sodium dodecyl sulphate gel electrophoresis), heat-labile glycoprotein; the amino acid composition is that of a globular protein. ci interferes at various steps of the complement sequence, including reactions of the classical and alternative pathway. ... | 1981 | 6914809 |
| effect of naja haje snake venom on guinea pig spleen and lymph nodes. | | 1980 | 7394827 |
| growth inhibition of trypanosoma cruzi and leishmania donovani infantum by different snake venoms: preliminary identification of proteins from cerastes cerastes venom which interact with the parasites. | venom from three different snake species was tested in vitro against the protozoan parasites trypanosoma cruzi and leishmania donovani infantum. two of them, cerastes cerastes and naja haje, exerted a significant growth inhibition of t. cruzi and l. d. infantum parasites. heating of the venoms abolished their activity, suggesting that the active factors are thermolabile. incubation of parasites with 125i-labelled c. cerastes venom proteins allowed preliminary identification of components which i ... | 1994 | 7985193 |
| comparative studies on egyptian elapid venoms. | the immunological properties of naja haje from western desert, naja haje of the nile delta, naja nigricollis from upper egypt and walternnesia aegyptia from sinai desert were compared using horse serum antivenin prepared from the delta naja haje venom. all elapid venoms showed very similar precipitin lines with immunodiffusion or immunoelectrophoresis on agar gel. results of cellulose-acetate electrophoresis showed either different concentration of certain similar protein components or the absen ... | 1980 | 6781151 |
| experimental study on developing rat kidney after naja haje envenomation. | in the present experiment 164 pregnant white wistar rats were used to study the effect of naja haje (egyptian cobra) venom on the developing kidney. the rats were divided into 3 groups; a control group, a group receiving one ld50 of n. haje venom and the third injected with 1/8 of ld50. the injection was performed at different stages of gestation. after birth, the neonates of group i and iii and embryos of group ii were examined histologically, histochemically and electron-microscopically. both ... | 1987 | 3577652 |
| short term effects of animal venoms on the mitotic index of the duodenal mucosa of albino rats. | short term administration of the venoms of the snakes naja haje, naja nigricollis, and cerastes vipera and of the scorpion leiurus quinquestriatus on the mitotic index of the duodenal mucosal cells of the white rat, rattus rattus, has been studied. all the venoms increased the number of dividing cells of the duodenal mucosa significantly. naja haje crude venom was fractionated into three fractions. fraction i had no effect on the mitotic index whereas fractions ii and iii increased it significan ... | 1992 | 1344905 |
| redescription of haemoproteus mesnili (apicomplexa: plasmodiidae) and its meronts, with description of a second haemosporidian parasite of african cobras. | haemoproteus mesnili (bouet 1909) wenyon 1926 is redescribed from the spitting cobra, naja nigricollis nigricollis, of tanzania. mature gametocytes in the acute phase of infection averaged 17.7 x 7.3 jim, with lw 128.1 jim-, and l:w ratio 2.52. nuclei were visible in both sexes. both sexes were heavily pigmented, with 31-62 black granules dispersed in macrogametocytes; 20-46 granules were often clumped or concentrated near ends of microgametocytes. the halteridial form was present in 28% of acti ... | 2007 | 17626363 |
| 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 |
| [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 |
| [which antivenom for cerastes envenoming?]. | during echis viper envenoming, the administration of a single fav-afrique(®) antivenin vial generally corrects hemostasis disorders in less than twelve hours. the correction of hemostasis after 36 hours by 4 vials of fav-afrique(®) is thus not in favor of the usefulness of this antivenin for cerastes envenoming . mortality due to viper envenoming in africa is high, but more than 90 % of poisoned patients survive despite the absence of appropriate antivenom. the severity of poisoning depends on s ... | 2016 | 24736220 |
| evaluation of the lethal potency of scorpion and snake venoms and comparison between intraperitoneal and intravenous injection routes. | scorpion stings and snake bites are major health hazards that lead to suffering of victims and high mortality. thousands of injuries associated with such stings and bites of venomous animals occur every year worldwide. in north africa, more than 100,000 scorpion stings and snake bites are reported annually. an appropriate determination of the 50% lethal doses (ld₅₀) of scorpion and snake venoms appears to be an important step to assess (and compare) venom toxic activity. such ld₅₀ values are als ... | 2014 | 24926799 |
| molecular cloning and characterization of a complement-depleting factor from king cobra, ophiophagus hannah. | cobra venom factor (cvf) is an anti-complement factor existing in cobra venom. cvf proteins have been purified from the venoms of naja haje, naja siamensis, naja atra, naja kaouthia, naja naja, naja melanoleuca and austrelaps superbus, but only three full-length cdna sequences of cvf are available. in the present work, a cobra venom factor termed ovf was purified from the crude venom of ophiophagus hannah by successive gel filtration, ion-exchange and heparin affinity chromatography steps. the p ... | 2012 | 22561424 |
| assessment of the antimicrobial activity of few saudi arabian snake venoms. | venoms of two cobras, four vipers, a standard antibiotic and an antimycotic, were evaluated comparatively, as antimicrobials. | 2015 | 26668657 |
| histopathological and histochemical effects of naja haje venom on kidney tissue of mice. | | 1999 | 1220085 |
| snake venom toxins. the amino acid sequence of three toxins (cm-2e, cm-4a and cm-) from naja haje annulifera (egyptian cobra) venom. | three toxins (cm-2e, cm-4a and cm-7) were purified from the venom of naja haje annulifera by gel filtration on sephadex and by ion-exchange chromatography on cm-cellulose. they comprise 60 amino acid residues and are cross-linked by four intrachain disulphide bridges. the complete amino acid sequences of the three toxins have been elucidated. the toxicities, the serological properties, the sequences and the invariant amino acid residues of toxin cm-2e, cm-4a and cm-7 resemble the corresponding p ... | 1976 | 1017800 |
| snake venom toxins. the amino-acid sequences of three toxins (cm-8, cm-11 and cm-13a) from naja haje annulifera (egyptian cobra) venom. | three toxins (cm-8, cm-11, and cm-13a) were purified from the venom of naja haje annulifera by gel filtration on sephadex g-50 and by ion-exchange chromatography on cm-cellulose. whereas toxin cm-8 and cm-11 comprise 60 amino acid residues, toxin cm-13a contains 61 residues. all three toxins are cross-linked by four intrachain disulphide bridges. the complete amino acid sequences of these toxins have been elucidated. the reduced and s-carboxymethylated toxins were digested with trypsin and chymo ... | 1976 | 1278155 |
| the amino acid sequence of toxin v ii 2, a cytotoxin homologue from banded egyptian cobra (naja haje annulifera) venom. | toxin v ii 2 comprises 60 amino acid residues and is cross-linked by four disulphide bridges. the complete amino acid sequence of this toxin was elucidated. the reduced and s-carboxymethylated toxin was digested with trypsin and chymotrypsin and the peptides were purified by ion-exchange chromatography and chromatography or electrophoresis on paper. the edman procedure, either through the use of the automatic sequenator or by manual manipulation, was employed to obtain the sequence of the intact ... | 1977 | 1213684 |
| purification and characterization of a cytotoxic neurotoxin-like protein from naja haje haje venom that induces mitochondrial apoptosis pathway. | this study reported the purification and characterization of a cytotoxic, neurotoxin-like protein derived from the venom of the egyptian cobra naja haje haje, elapidae family, and explored their mechanistic role in the cell death. the protein purification was performed through ion-exchange chromatography and gel-filtration chromatography and was characterized by sds-page, amino acid sequencing, and mass spectrum analysis. the antitumor activity of naja haje venom (nhv) and its fractions (nhvi, n ... | 2011 | 21240479 |
| a new type of thrombin inhibitor, noncytotoxic phospholipase a2, from the naja haje cobra venom. | thrombin is a key enzyme in the blood coagulation cascade and is also involved in carcinogenesis; therefore, its inhibitors are of fundamental and clinical importance. snake venoms are widely used as sources of proteins that affect blood coagulation. we have isolated a new protein, called ti-nh, from the naja haje cobra venom. ti-nh is a mixed-type inhibitor of thrombin (k(i) of 72.8 nm for a synthetic peptide substrate) and effectively inhibits thrombin-induced platelet aggregation with an ic(5 ... | 2010 | 19622365 |
| assessment of the anti-naja haje antibodies elicited in a low dose multi-site immunization protocol. | the horse antibodies to naja haje (nh) elicited in a low dose multi-site immunization protocol were investigated from binding perspective in the context of antivenom maturation. we found that, this protocol evoked the production of lethality neutralizing avid antibodies in the first round of immunization which increases over the successive immunization rounds. the changes and the relative changes in the antibody parameters of each horse were taken as a measure for the efficacy of its immune syst ... | 2009 | 19464310 |
| cancer cell injury by cytotoxins from cobra venom is mediated through lysosomal damage. | cytotoxins from cobra venom are known to manifest cytotoxicity in various cell types. it is widely accepted that the plasma membrane is a target of cytotoxins, but the mechanism of their action remains obscure. using the confocal spectral imaging technique, we show for the first time that cytotoxins from cobra venom penetrate readily into living cancer cells and accumulate markedly in lysosomes. cytotoxins ct1 and ct2 from naja oxiana, ct3 from naja kaouthia and ct1 from naja haje are demonstrat ... | 2005 | 15847607 |
| comparative study of structure and activity of cytotoxins from venom of the cobras naja oxiana, naja kaouthia, and naja haje. | cytotoxins are positively charged polypeptides that constitute about 60% of all proteins in cobra venom; they have a wide spectrum of biological activities. by cd spectroscopy, cytotoxins ct1 and ct2 naja oxiana, ct3 naja kaouthia, and ct1 and ct2 naja haje were shown to have similar secondary structure in an aqueous environment, with dominating beta-sheet structure, and to vary in the twisting angle of the beta-sheet and the conformation of disulfide groups. using dodecylphosphocholine micelles ... | 2004 | 15527416 |
| a bradykinin potentiating peptide from egyptian cobra venom strongly affects rat atrium contractile force and cellular calcium regulation. | peptide fractions were isolated from venoms of the egyptian snake naja haje haje (cobra bpp) and the scorpions buthus occitanus (bpp(b)) and leirus quenquestriatus (bpp(l)). the pharmacological effects of these peptides were bioassayed and showed bradykinin potentiating activities. amino acid analysis revealed that 14 amino acids contribute to the structure of bpp(b) and 16 for bpp(l), while cobra bpp was composed of 15 amino acids. treatment of rat atrial preparations with 50 microg/ml of cobra ... | 2003 | 15012910 |
| snake alpha-neurotoxin binding site on the egyptian cobra (naja haje) nicotinic acetylcholine receptor is conserved. | evolutionary success requires that animal venoms are targeted against phylogenetically conserved molecular structures of fundamental physiological processes. species producing venoms must be resistant to their action. venoms of elapidae snakes (e.g., cobras, kraits) contain alpha-neurotoxins, represented by alpha-bungarotoxin (alpha-btx) targeted against the nicotinic acetylcholine receptor (nachr) of the neuromuscular junction. the model which presumes that cobras (naja spp., elapidae) have los ... | 2001 | 11504859 |
| histological and histochemical alterations in the liver following intramuscular injection with a sublethal dose of the egyptian cobra venom. | in the present study, the effects of intramuscular (i.m.) injection of a sublethal dose (0.015 microgram/gm b.wt.) of naja haje venom were histologically and histochemically examined in the hepatic tissues of rabbits after 3, 6, and 12 hr. of envenomation. three hours after venom injection, the hepatic cells showed a generalized cytoplasmic granulation and cellular swelling accompanied with narrowing of the sinusoidal spaces. occurrence of inflammatory cells and hypertrophy of kupffer cells were ... | 2000 | 10701178 |
| hyperglycemic effect of a neurotoxic fraction (f3) from naja haje venom: role of hypothalamo-pituitary adrenal axis (hpa). | the effect of bolus intravenous injection of sub-ld50 (35 micrograms kg-1) of the neurotoxic fraction (f3) of the egyptian cobra naja haje on the plasma level of acth and serum levels of cortisol, insulin, glucose, total lipids, triacylglycerols, free fatty acids, total cholesterol, hdl and ldl-cholesterol, and glycogen content of liver and kidneys were studied in rabbit pretreated with cyproteron acetate (ca) or saline solution and propylene glycol (pg) to elucidate the possible role of the hyp ... | 1999 | 10410331 |
| [neurotoxic effects of cobra venom (naja haje haje) on the neuromuscular junction. electroclinical study of two cases in tunisia]. | two patients were bitten by tunisian cobras (naja haje haje). a few hours after the bite they developed generalized paralysis which progressed to respiratory paralysis. electrophysiological features are similar to those of myasthenia gravis and exhibit decremental pattern after stimulation at a frequency of three per second. it is probable that cobra neurotoxins act postsynaptically. the neuromuscular blocking activity of snake-venom can be reversed by intravenous neostigmine. | 1995 | 7603413 |
| anticholinesterases and experimental envenomation by naja. | danger from snake bites, especially those of elapidae, pose a public health problem in a large number of tropical and sub-tropical countries. since the advent of serotherapy, the morality rate has decreased, but suitable sera are not always available, explaining the usefulness of developing symptomatic treatments. the present study is a test of the preventative and curative efficacy of anticholinesterases in the treatment of naja haje haje venom envenomation. it is clearly shown that the early u ... | 1994 | 7894888 |
| [genetic origin of venom variability: impact on the preparation of antivenin serums]. | one of the main possible origin of the biochemical variations of venoms could be genetic. we studied the venom of members of litters born in a snake farm (12 crotalus atrox and 21 naja haje). we first used the electrophoresis in cellulose acetate (ae). then, variations were confirmed by immunoelectrophoresis (aie) using an antivenom (ipser africa, pasteur mérieux sérums & vaccines) and immunsera prepared on rabbit from i) venom presenting the maximum of bands in electrophoresis (complete venom) ... | 1997 | 9479469 |
| changes in the arterial blood pressure, heart rate and normal ecg parameters of rat after envenomation with egyptian cobra (naja haje) venom. | 1. the effect of egyptian cobra (naja haje) venom on the normal electrical activity of the cardiac muscles (ecg) and arterial blood pressure of envenomated rats were investigated in this study. 2. rats were divided into three groups. the first group was injected im with saline and considered as control group. rats of the second and third groups were injected im with 0.02 micrograms and 0.04 micrograms cobra venom/gim b.wt, respectively. 3. mean blood pressure (mbp), heart rate (hr) and four diff ... | 1997 | 9219029 |
| a three-compartment open pharmacokinetic model can explain variable toxicities of cobra venoms and their alpha toxins. | the pharmacokinetic profiles of labelled naja melanoleuca, naja nivea, naja nigricollis and naja haje venoms and their alpha neurotoxins were determined following rapid i.v. injection into rabbits. the data obtained fitted a triexponential equation characteristic of a three-compartment open pharmacokinetic model comprising a central compartment 'blood', a rapidly equilibrating 'shallow' tissue compartment and a slowly equilibrating 'deep' tissue compartment. the distribution half-lives for the s ... | 1996 | 8896193 |
| the preparation of 3-nitrotyrosyl derivatives of three elapid venom cardiotoxins. | nitration studies using tetranitromethane were conducted on the tyrosine residues of cardiotoxins, naja melanoleuca vii1, naja haje annulifera vii1 and hemachatus haemachates toxin 12b. various partially and fully nitrated derivatives were formed. analysis of the products of nitrating naja melanoleuca vii1 showed that the average relative reactivities of the three tyrosine residues were tyr-25 greater than tyr-22 greater than tyr-51. it was significant that tyr-51 could be easily modified in bot ... | 1980 | 7417487 |
| purification, some properties and the primary structures of three reduced and s-carboxymethylated toxins (cm-5, cm-6 and cm-10a) from naje haje haje (egyptian cobra) venom. | three reduced and s-carboxymethylated toxins (cm-5, cm-6 and cm-10a) were purified from naja haje haje (egyptian cobra) venom. whereas toxin cm-5 comprises 71 amino acid residues and five intrachain disulphide bridges, toxins cm-6 and cm-10a contain each 61 residues and four disulphide bridges. the complete primary structures of the three toxins have been established. the toxicity, the immunochemical properties, the sequence and the invariant amino acid residues of toxin cm-5 resemble the proper ... | 1978 | 718974 |
| naja haje haje (egyptian cobra) venom. some properties and the complete primary structure of three toxins (cm-2, cm-11 and cm-12). | three toxins (cm-2, cm-11 and cm-12) were purified from naja haje haje (egyptian cobra) venom. whereas toxin cm-11 contains 65 amino acid residues and five intrachain disulphide bridges, toxin cm-2 and cm-12 comprise, respectively, 61 and 62 residues but both contain four disulphide bridges. the complete primary structures of the three toxins have been established. the sequence and the invarient amino acid residues of cm-2 resemble those of part of a long neurotoxin, a short neurotoxin and a cyt ... | 1978 | 710433 |
| snake venom toxins. the amino acid sequences of two toxins (cm-2a and cm-3) from naja haje annulifera (egyptian cobra) venom. | two toxins, cm-2a and cm-3, were purified from the venom of naja haje annulifera by gel filtration on sephadex g-50 and by ion-exchange chromatography on cm-cellulose. whereas toxin cm-2a contains 61 amino acid residues, toxin cm-3 comprises 60 residues. both toxins are cross-linked by four intra-chain disulphide bridges. the complete amino acid sequences of the toxins have been elucidated. the properties of the toxins were compared with those of a cytotoxin, a short neurotoxin, a long neurotoxi ... | 1977 | 852822 |
| snake venom toxin. the amino acid sequence of three toxins (cm-2h, cm-4b and cm-6) from naja haje annulifera (egyptian cobra) venom. | three toxins cm-2h, cm-4b and cm-6 were purified from the venom of naja haje annulifera by gel filtration on sephadex and by ion-exchange chromatography on cm-cellulose. they comprise 60 amino acid residues and are cross-linked by four intrachain disulphide bridges. the complete amino acid sequences of the three toxins have been elucidated. the toxicities, the serological properties, the sequences and the invariant amino acid residues of toxin cm-2h, cm-4b and cm-6 resemble the corresponding pro ... | 1977 | 838473 |
| the purification and amino acid sequence of toxin cm-13b from naja haje annulifera (egyptian cobra) venom. | toxin cm-13b was purified from the venom of naja haje annulifera by gel filtration on sephadex g-50 and by ion-exchange chromatography on cm-cellulose. the toxin comprises 65 amino acid residues and is cross-linked by five disulphide bridges. the complete amino acid sequence of toxin cm-13b was elucidated. the reduced and s-carboxymethylated toxin was digested with trypsin and chymotrypsin and the peptides purified by deae-cellulose chromatography and chromatography or electrophoresis on paper. ... | 1975 | 1213685 |
| snake venom toxins. the purification of toxins vii1 and vii2, two cytotoxin homologues from banded egyptian cobra (naja haje annulifera) venom, and the complete amino acid sequence of toxin vii1. | | 2013 | 4803830 |
| purification of animal neurotoxins. isolation and characterization of four neurotoxins from two different sources of naja haje venom. | | 1970 | 5531254 |
| the chondrocranium of late embryos of the egyptian cobra, naja haje. | | 1970 | 5520286 |
| a neurotoxin, toxin alpha, from egyptian cobra (naja haje haje) venom. i. purification, properties, and complete amino acid sequence. | | 1969 | 4308169 |
| [presence in tunisia of hexametra quadricornis wedl. (nematoda, ascaroidea), parasite of naja haje (reptilia, ophidia)]. | | 1963 | 13958033 |
| [pharmacological characterization of electrophoretic fractions of naja nigricollis and naja haje venoms]. | | 1954 | 13221270 |
| [electrophoretic analysis of naja haje and naja nigricollis venoms. snake venoms. ii]. | | 1954 | 13221268 |
| [studies on venoms of naja haje, naja nigricollis, lachesis gramineus and ancistrodon piscivorus]. | | 1953 | 13125004 |
| synthetic peptide antigens derived from long-chain alpha-neurotoxins: immunogenicity effect against elapid venoms. | three-finger toxins (3ftxs), especially α-neurotoxins, are the most poorly neutralized elapid snake toxins by current antivenoms. in this work, the conserved structural similarity and motif arrangements of long-chain α-neurotoxins led us to design peptides with consensus sequences. eight long-chain α-neurotoxins (also known as type ii) were used to generate a consensus sequence from which two peptides were chemically synthesized, lcp1 and lcp2. rabbit sera raised against them were able to genera ... | 2017 | 28010961 |
| unique features of myogenesis in egyptian cobra (naja haje) (squamata: serpentes: elapidae). | during early stages of myotomal myogenesis, the myotome of egyptian cobra (naja haje) is composed of homogenous populations of mononucleated primary myotubes. at later developmental phase, primary myotubes are accompanied by closely adhering mononucleated cells. based on localization and morphology, we assume that mononucleated cells share features with satellite cells involved in muscle growth. an indirect morphological evidence of the fusion of mononucleated cells with myotubes is the presence ... | 2016 | 26025263 |
| protective effects of melatonin against oxidative damage induced by egyptian cobra (naja haje) crude venom in rats. | naja haje envenomation is one of the leading causes of death due to snakebite. antiserum therapy sometimes fails to provide enough protection against venom toxicity. in this study, we investigated the protective effects of melatonin against n. haje venom in rats. the animals were injected with venom (0.25mg/kg) and/or melatonin (10mg/kg) and compared with vehicle-treated rats. there was oxidative/nitrosative damage and apoptosis in the liver, heart, and kidneys of venom-injected rats. melatonin ... | 2015 | 25542296 |
| proteomic analysis of moroccan cobra naja haje legionis venom using tandem mass spectrometry. | the proteome of the venom of naja haje legionis, the only medically important elapid species in morocco, has been elucidated by using a combination of proteomic techniques that includes size exclusion chromatography, reverse-phase hplc, tricine/sds-page, tryptic digestion, q-tof tandem mass spectrometry and database search. the sequence analysis of venom fractions revealed a highly complex venom proteome which counts a total of 76 proteins identified from database that can be assigned into 9 pro ... | 2014 | 24269350 |
| identification and discrimination of snake venoms from egyptian elapids. | the avidity to the corresponding antigens is often higher than to the cross-reactive antigens. this was demonstrated with the highly cross-reactive elapid egyptian snake venoms naja haje (nh), naja nigricollis (nn) and walterinnesia aegyptia (wa), and used for the differentiation among the three species in a simple elisa-based assay. a three-step immuno-affinity protocol was followed and the titer and avidity of the different antibody (ab) preparations were assessed and evaluated. the advantages ... | 2013 | 23220490 |
| cobra venom contains a pool of cysteine-rich secretory proteins. | a large family of cysteine-rich secretory proteins (crisps) includes proteins of different origin, the function of the majority of crisps being unknown. for crisps isolated from snake venom, two types of activities were found: two proteins blocked cyclic nucleotide-gated ion channels, several others blocked potassium-stimulated smooth muscle contraction. thus, snake crisps represent potentially valuable tools for studies of ion channels, which makes promising a search for new crisps. here we rep ... | 2005 | 15670767 |
| functional role of the noncatalytic subunit of complement c5 convertase. | the c5 convertase is a serine protease that consists of two subunits: a catalytic subunit which is bound in a mg2+-dependent complex to a noncatalytic subunit. to understand the functional role of the noncatalytic subunit, we have determined the c5-cleaving properties of the cobra venom factor-dependent c5 convertase (cvf, bb) made with cvf purified from the venom of naja naja (cvfn) and naja haje (cvfh) and compared them to those for two c3b-dependent c5 convertases (zymc3b,bb and c3b,bb). a co ... | 2000 | 10640753 |
| gamma irradiation of egyptian cobra (naja haje) venom. | the aim of the present study was to prepare an effective and safe toxoid for the egyptian cobra (naja haje) venom by gamma irradiation. the effects of gamma irradiation (0.1-10 m rad) on the toxicity, as well as the antigen antibody complex formation reactivity was described. it appears from the results that the lethality of naja haje venom irradiated in the dry form was not affected up to a dose of 10 m rad (100 kgy). on the other hand, the venom irradiated in the aqueous solution form showed a ... | 1996 | 17217012 |
| scales microstructure of snakes from the egyptian area. | the morphology of many organisms seems to be related to the environments in which they live. many snakes are so similar in their morphological patterns that it becomes quite difficult to distinguish any adaptive divergence that may have occurred. many authors have suggested that the microstructure of the reptile's scales has important functional value. herein, we investigate variations on the micromorphology of the external surface of dorsal scales on the head, the mid-body region (trunk), and t ... | 2012 | 23106563 |
| cross neutralization of dangerous snake venoms from africa and the middle east using the vacsera polyvalent antivenom. egyptian organization for biological products & vaccines. | this study was performed to assess the ability of polyvalent snake venom anti-serum, produced by the egyptian organization for biological products & vaccines (vacsera), to neutralize several toxic activities of snake venoms, not only of those included in the antivenom mixture, but also some additional venoms of snakes from egyptian, african, and middle eastern habitats. in general, the results revealed that polyvalent snake venom anti-serum from vacsera is highly effective in neutralizing egypti ... | 2002 | 12503876 |
| immunological properties of antivenins. ii. univalent naja haje antivenin. | a purified naja haje antivenin was tested against egyptian n. haje and n. nigricollis venoms, indian n. naja venom, iranian n. naja oxiana, vipera lebetina, and v. persica venoms, and echis carinatus venom from both iran and egypt. the different elapid venoms, with the exception of that of n. naja oxiana, showed a considerable number of identical and similar precipitin components by immunodiffusion and immunoelectrophoresis. on the other hand, only a few identical and partially identical lines w ... | 1976 | 816220 |
| state of functionally essential trp-29 in snake venom neurotoxins: a proton nuclear magnetic resonance study. | proton nuclear magnetic resonance (nmr) spectra have been recorded of various neurotoxins from snake venoms. ph dependence of the chemical shifts and resonance intensity has been followed for the functionally essential trp-29. the indole n-1 proton of trp-29 in alpha-bungarotoxin, toxin b, and cobrotoxin exhibits appreciably large upfield shifts as the ph is lowered and the suppressed exchange with the solvent hydrogen at ph 3-4, but not in naja haje annulifera 10 where asp-31 is replaced with g ... | 1989 | 2803518 |
| biosynthesis, secretion and in vivo isotopic labelling of venom of the egyptian cobra, naja haje annulifera. | the venom glands of elapidae differ from those of the viperidae by lacking an expanded central lumen; the venom is stored in the tubular lumina as well as inside the cells in densely packed secretion granules. using isotope tracer techniques, it was found that in the egyptian cobra (naja haje annulifera) venom is secreted both from pre-existing and from newly-formed granules. the rate of protein biosynthesis peaks at 4-9 days after venom was extracted (milked) from the glands. highly labelled to ... | 1982 | 7101309 |
| histopathological effects of naja haje snake venom and a venom glad extract of the scorpion buthus quinquestriatus on the liver, suprarenal gland and pancreas of mice. | | 1978 | 653753 |
| neurotoxic effects of bites by the egyptian cobra (naja haje) in nigeria. | two patients were bitten by egyptian cobra (naja haje). one became drowsy and developed transient ptosis 24 hours later. the other lost consciousness and died within two hours of the bite, but no cause was revealed by autopsy. a third patient developed severe transient neurological signs after being bitten by an unidentified snake. the small literature on bites by this species is discussed. | 1976 | 1265823 |
| amino-acid sequence of toxin iii of naja haje. | the complete amino acid sequence of toxin iii of naja haje (72 residues) has been established mainly by use of a protein sequenator (identification of 70 residues). the two c-terminal residues have been determined by digestion with carboxypeptidases a and b. addition of succinylated protein or peptide greatly improved the performance of the sequenator for the edman degradation of peptides: on one peptide (39 residues) degradation went to step 34 with a protein program and on two peptides (10 and ... | 1975 | 1183429 |
| structure-function relationship in the binding of snake neurotoxins to the torpedo membrane receptor. | the cys30-cus34 bridge present in all long neutotoxins (71-74 amino acids, 5 disulfide bridges), but not in short toxins (60-63 amino acids, 4 disulfide bridges), is exposed at the surface since it can be reduced rapidly and selectively by sodium borohydride. reduction and alkylation of the cys30-cys34 bridge of naja haje neurotoxin iii hardly alter the conformational properties of this model long toxin. although alkylation by iodoacetic acid of th -sh groups liberated by reduction abolishes the ... | 1975 | 1148159 |
| characterization of five neurotoxins isolated from the venoms of two elapidae snakes naja haje and naja nigricollis. | | 1973 | 4736919 |
| cross-neutralisation of the neurotoxic effects of egyptian cobra venom with commercial tiger snake antivenom. | cross-neutralisation has been demonstrated for haemorrhagic venoms including echis spp. and cerastes spp. and for australia elapid procoagulant toxins. a previous study showed that commercial tiger snake antivenom (tsav) was able to neutralise the systemic effects of the egyptian cobra, naja haje, in vivo but it is unclear if this was true cross-neutralisation. the aim of the current study was to determine whether tsav can neutralise the in vitro neurotoxic effects of n. haje venom. both notechi ... | 2013 | 22788931 |
| hepatotoxicity and oxidative stress induced by naja haje crude venom. | snake venoms are synthesized and stored in venom glands. most venoms are complex mixtures of several proteins, peptides, enzymes, toxins and non-protein components. in the present study, we investigated the oxidative stress and apoptosis in rat liver cells provoked by naja haje crude injection (ld50) after four hours. | 2014 | 25258623 |
| structure-function relationships of neurotoxins isolated from naja haje venom. physiochemical properties and identification of the active site. | | 1972 | 5028111 |
| distinctive distribution of secretory phospholipases a₂ in the venoms of afro-asian cobras (subgenus: naja, afronaja, boulengerina and uraeus). | the protein abundances of phospholipases a₂ in cobra venom proteomes appear to vary among cobra species. to determine the unique distribution of snake venom phospholipases a₂ (svpla₂) in the cobras, the svpla₂ activities for 15 cobra species were examined with an acidimetric and a colorimetric assay, using egg yolk suspension and 4-nitro-3-octanoyloxy benzoic acid (noba) as the substrate. the colorimetric assay showed significant correlation between svpla₂ enzymatic activities with the svpla₂ pr ... | 2019 | 30769779 |
| in vivo anti-complementary activities of the cobra venom factors from naja naja and naja haje. | the kinetics of complement (c) depletion and recovery of c levels upon injection of balb/c mice with cobra venom factors (cvf), from n. naja (c3- and c5-depleting) and n. haje (selectively c3-depleting) were studied. the animals received i.p. or i.v. injections of either of the two preparations. ch50 and hemolytic c3 and c5 levels were followed as parameters of residual complement activity. n. naja cvf turned out to be as efficient in depleting total complement activity as n. haje cvf. decreased ... | 1991 | 1999656 |
| [major complement inhibiting factors from the venom of the central asian cobra naja naja oxiana]. | the properties of two anticomplementic factors isolated by cm-sepharose chromatography from the basic non-adsorbed on deae-sepharose fraction of the central asian cobra naja naja oxiana venom, were studied. of these three factors (cfb-i, cfb-ii and cfb-iii) the latter had been characterized earlier. cfb-i was shown to be a protein with an n-terminal asp and a molecular mass of about 39 kda (data from gel chromatography); its content in the venom is 3.6 mg/g of dry venom. the protein inhibits mai ... | 1989 | 2627558 |
| chain structure of cobra venom factor from naja naja and naja haje venom. | the chain structure of cobra venom factor, whether isolated from naja naja venom (cvfn) or from naja haje (cvfh) is similar. both homologous proteins are composed of three disulphide-linked chains (a, b, and c) with apparent molecular weights of 72,000, 54,000, and 27,000-35,000 for cvfn and 68,000, 51,000 and 30,000-32,000 cvfh. that all three polypeptides are integral parts of cvf was demonstrated by investigation of the chain pattern after partial reduction. reduction with 1-2 mm dithiothreit ... | 1982 | 7100817 |
| the effect of maternal envenomation by naja haje (egyptian cobra) snake on the developing central nervous system. | | 1980 | 7394557 |
| naja haje (egyptian cobra) venom. purification, some properties and the amino acid sequences of four toxins (cm-7, cm-8, cm-9, and cm-10b). | four toxins (cm-7, cm-8, cm-9 and cm-10b) were purified from naja haje haje (egyptian cobra) venom by gel filtration on sephadex g-50 followed by ion-exchange chromatography on cm-cellulose. they each contain 60 amino acid residues and are cross-linked by four intrachain disulphide bridges. the complete primary structure of the four toxins have been elucidated. the toxicities, the immunochemical properties, the sequences and invariant amino acid residues opf toxins cm-7, cm-8, cm-9 and cm-10b re ... | 1978 | 667107 |
| a decoy-receptor approach using nicotinic acetylcholine receptor mimics reveals their potential as novel therapeutics against neurotoxic snakebite. | snakebite is a neglected tropical disease that causes 138,000 deaths each year. neurotoxic snake venoms contain small neurotoxins, including three-finger toxins (3ftxs), which can cause rapid paralysis in snakebite victims by blocking postsynaptic transmission via nicotinic acetylcholine receptors (nachrs). these toxins are typically weakly immunogenic and thus are often not effectively targeted by current polyclonal antivenom therapies. we investigated whether nachr mimics, also known as acetyl ... | 2019 | 31417406 |