| effect of hydrolytic enzymes and protein-modifying reagents on gonadotropin receptors in bovine corpus luteum cell membranes. | preincubation of membranes with various concentrations of pronase, trypsin, lipase, phospholipase a from vipera russelli and from crotalus durissus terrificus, phospholipase c from bacillus cereus and from clostridium welchii, acetic anhydride, 2,4-dinitrofluorobenzene and tetranitromethane resulted in a dose-dependent inhibition of 125i-labeled human choriogonadotropin binding. at the submaximal concentrations of enzymes and at both submaximal and maximal concentrations of protein-modifying rea ... | 1978 | 202334 |
| the mode of action at the mouse neuromuscular junction of the phospholipase a-crotapotin complex isolated from venom of the south american rattlesnake. | 1 phospholipase a(2)-crotapotin complex (p-c complex) isolated from the venom of crotalus durissus terrificus induced an irreversible blockade of neuromuscular transmission when twitch tension was measured in the mouse phrenic nerve-hemidiaphragm preparation in vitro at 37 degrees c.2 a similar concentration of the phospholipase a(2) (10 mug/ml) alone did not affect neuromuscular transmission and no priming action was detected on later addition of crotapotin.3 the rate of neuromuscular blockade ... | 1977 | 202359 |
| search for relationships among the hemolytic, phospholipolytic, and neurotoxic activities of snake venoms. | several snake venom neurotoxins are larger and more complex than the well-studied group of postsynaptic toxins exemplified by alpha-bungarotoxin. several of these, exemplified by beta-bungarotoxin, show phospholipase a2 activity (phosphatide 2-acylhydrolase, ec 3.1.1.4) when tested in the presence of detergents. the high hemolytic activity of crotoxin, the neurotoxin of crotalus durissus terrificus, in the presence of lecithin has been attributed to this activity. the phospholipase a2 activity o ... | 1978 | 273221 |
| [early effect of crotalus durissus terrificus venom on kidney circulation]. | local blood flow was measured in renal cortex (1 mm below cortical surface) by means of the hydrogen clearance method in urethanized rats. recording of blood pressure from femoral artery was performed. crotalus durissus terrificus venom injection (one mg/kg i.v.) significantly decreased cortical blood flow at 10 min, without a significant arterial pressure modification. posterior injection of mannitol 200 mg induced a significant increase in cortical blood flow, although initial values were not ... | 1978 | 555830 |
| [occurrence of salmonella in healthy snakes and snake cadavers- isolation of a new salmonella species belonging to the sub-genus iv (s. iv 18:z36, z38:-) (author's transl)]. | forty-seven isolation attempts performed with 20 fecal samples of exotic snakes yielded 27 salmonella species belonging to the sub-genus i-iv. the majority of isolates (78.7%), however, was identified as sub-genus iii (arizona). the snakes under study were hold captured for less than one year (one part) or for longer than one year. bacteriological investigations of the 7 snakes studied, repeated 7 to 21 months thereafter, revealed uniformly other salmonella species in comparison to those found a ... | 1976 | 1015030 |
| detoxification of the crotoxin complex by gamma radiation. | 1. crotoxin, the major neurotoxin of the south american rattlesnake venom (2 mg protein/ml in 0.85% nacl) was irradiated with a co-60 gamma source at a dose rate of 1100 gy/h and at doses of 250, 500, 1000, 1500 and 2000 gy. 2. irradiated crotoxin was analyzed for free sh-groups, protein concentration, electrophoretic profile (sds-page), 50% lethal dose (ld50) in mice, and antigenicity against crotalic antiserum by diffusion immunoassay. 3. irradiation led to the formation of protein aggregates ... | 1992 | 1339505 |
| [the epidemiology and clinical picture of an accidental bite by the south american rattlesnake (crotalus durissus)]. | under study were two hundred and forty-nine cases of accidents caused by south american rattlesnakes (crotalus durissus) admitted to the vital brasil hospital, são paulo, brasil, from 1974 to 1990. the accidents were more common in the afternoon, from january to april and from october to december. ninety nine out of 100 snakes classified as subspecies were c. d. terrificus. most of the patients were males (80.7%). the inferior and superior limbs were bitten in 66.4% and 29.2% of the cases, respe ... | 1992 | 1342093 |
| the effect of crotoxin on the release of acetylcholine and lactate dehydrogenase from rat brain cortical slices. | 1. we have studied the effects of crotoxin, the neurotoxin of the south american rattlesnake crotalus durissus terrificus, on the release of acetylcholine and lactate dehydrogenase from rat brain cortical slices. 2. crotoxin enhances the release of [3h]-acetylcholine from cortical slices (control values 92.8 +/- 5.9 and 150.3 +/- 11.7 dpm/mg and crotoxin values 199.1 +/- 7.0 and 336.0 +/- 26.0 dpm/mg, at 60 and 120 min incubation, respectively) in parallel with the release of lactate dehydrogena ... | 1992 | 1342601 |
| antivenom and biological effects of ar-turmerone isolated from curcuma longa (zingiberaceae) | a potent antivenom against snakebite was isolated from curcuma longa, a plant commonly used in traditional brazilian medicine. the fraction consisting of ar-turmerone neutralized both the hemorrhagic activity present in bothrops jararaca venom, and the lethal effect of crotalus durissus terrificus venom in mice. immunological studies demonstrated that this fraction also inhibited the proliferation and the natural killer activity of human lymphocytes. | 1992 | 1440627 |
| evaluation of four different immunogens for the production of snake antivenoms. | four different immunogens were used to produce polyvalent antivenom in rabbits to the venoms of bothrops atrox, crotalus atrox, crotalus adamanteus and crotalus durissus terrificus. the immunogens were: (1) unfractionated mixture of the four crude venoms, and three fractions of the mixture as follows, (2) hplc gel filtration high (> 50,000) mol. wt fraction, (3) hplc gel filtration medium (14,000-50,000) mol. wt fraction, and (4) hplc gel filtration low (< 14,000) mol. wt fraction. the resultant ... | 1992 | 1485332 |
| pioneers of anti-venomous serotherapy: dr vital brazil (1865-1950). | dr vital brazil was a great humanitarian and pioneer of medical science. his main work arose from his concern with poisonous snakebite accidents to labourers working the land. vital brazil estimated that, at the beginning of this century, deaths due to crotaline snakebites in the state of são paulo, brazil, were nearly 3000 per year, representing a mortality rate of about 25%, the majority being due to bothropic envenomation. after reading a report of calmette's anti-naja serum, vital brazil rai ... | 1992 | 1519249 |
| [pharmacologic and enzymatic effects of snake venoms from antioquia and choco (colombia)]. | we compared several pharmacological and enzymatic effects induced by 11 snake venoms from seven species, six of them from different geographic areas of antioquia and choco, north-west of colombia, south america (bothrops atrox, b. nasutus, b. schlegelii, b. punctatus, lachesis muta, micrurus mipartitus), and crotalus durissus terrificus venom, from specimens captured in other provinces of the country (tolima, huila, meta and atlantico). differences were observed in edema-forming, hemorrhage, def ... | 1992 | 1519252 |
| measurement of human phospholipase a2 in arthritis plasma using a newly developed sandwich elisa. | a sandwich enzyme-linked immunosorbent assay (elisa) for human non-pancreatic phospholipase a2 (pla2) was developed using monoclonal antibodies raised against purified recombinant pla2. this assay was shown to be specific for human non-pancreatic pla2, showing no cross-reactivity with human pancreatic pla2 or with snake venom pla2 (crotalus durissus). the immunoassay showed no cross-reactivity with plasma components, and was reproducible and quantitative between 39 pmol and 2.7 nmol pla2/1. the ... | 1992 | 1540785 |
| characterization and quantification of diadenosine hexaphosphate in chromaffin cells: granular storage and secretagogue-induced release. | the presence of diadenosine hexaphosphate (ap6a) in chromaffin cells is described. the characterization of ap6a has been accomplished by hplc techniques, using three different elution conditions, rechromatography, and coelution with standards. treatment with phosphodiesterase from crotalus durissus produced amp and adenosine pentaphosphate. the hplc techniques described allowed the quantification of ap6a in the picomole range. chromaffin granules store ap6a in a quantity of 48.5 +/- 9.7 nmol/mg ... | 1992 | 1632493 |
| synthesis and physicochemical properties of oligonucleotides built with either alpha-l or beta-l nucleotides units and covalently linked to an acridine derivative. | modified deoxynucleosides 2'-deoxy-beta-l-uridine, beta-l-thymidine, alpha-l-thymidine, 2'-deoxy-beta-l-adenosine and 2'-deoxy-alpha-l-adenosine were synthesized and assembled as homooligomers, respectively: octa-beta-l-deoxyuridylates, octa beta-l and alpha-l-thymidylates and tetra beta-l and alpha-l-deoxyadenylates. these unnatural oligomers were then substituted with an acridine derivative. the binding studies of these modified oligonucleotides with d-ribo- and d-deoxyribopolynucleotides were ... | 1991 | 1651474 |
| immunological studies with the venom of the scorpion tityus serrulatus. | 1. we describe a "sandwich" enzyme-linked immunosorbent assay (elisa) sensitive to quantities of scorpion (tityus serrulatus) venom (tsv) in the range of 1-3 ng/ml sample. 2. cross-reactivity with the venom from the rattlesnake crotalus durissus terrificus and with venoms from several snakes of the bothrops genus was detected only at concentrations higher than 1 microgram/ml sample. 3. a conventional elisa is also described for the detection of antibodies against tsv. 4. analysis by western blot ... | 1991 | 1823231 |
| immunization of horses with crotalus durissus terrificus (south american rattlesnake) venom. a comparison of four different procedures. | 1. a comparative study was carried out on horses immunized with crotalus durissus terrificus venom using four different inoculation procedures, which included the use of freund's adjuvant, a1(oh)3 and liposomes as adjuvants. the antibody titer was assessed by enzyme linked immunosorbent assay (elisa) and the neutralizing potency by the neutralizing median effective dose (ed50). 2. the inoculation schedule used in horses to obtain antivenom serum consisted of sc injections of a 7.5 mg venom start ... | 1991 | 1823242 |
| [crotalid bites in children: clinical, laboratory, epidemiologic aspects and treatment approach]. | at the hospital of clinics of the faculty of medicine of ribeirão preto/usp during the years 1980-1989 21 children have been attended after rattlesnake bite: 16 severe and 5 with moderate envenomation. four (20%) developed acute tubular necrosis 2 necessitating dialysis. one patient died 13 days after the bite and grave complications including digestive hemorrhage and acute respiratory insufficiency. all patients preserved clinical laboratory and epidemiological characteristics of crotalus duris ... | 1991 | 1841432 |
| immunochemical cross-reactivity of two phospholipase a2 neurotoxins, agkistrodotoxin and crotoxin. | polyclonal rabbit antisera were raised against the phospholipase a2 neurotoxin agkistrodotoxin (agtx) from agkistrodon blomhoffii brevicaudus venom and against the phospholipase a2 subunit (component-b, cb) of crotoxin from crotalus durissus terrificus venom. anti-agtx antibodies cross-reacted strongly with crotoxin and crotoxin-like molecules and more weakly with other phospholipases a2 from the venoms of viperidae and crotalidae. on the other hand, anti-cb antibodies cross-reacted with agtx, a ... | 1991 | 1862520 |
| susceptibility of different strains of mice to south american rattlesnake (crotalus durissus terrificus) venom: correlation between lethal effect and creatine kinase release. | in the present work we report that susceptibility to crotalus durissus terrificus venom: varies according to the strain of inbred mouse used. the s.c. ld50 for balb/c and c57bi/6 mice were 193 micrograms/kg and 171 micrograms/kg, whereas for a/j and dba/j they were 78 micrograms/kg and 74 micrograms/kg, respectively. in addition, a direct correlation between susceptibility to c. d. terrificus venom and creatine kinase serum levels (ck) was observed. | 1991 | 1926179 |
| an indirect haemolytic assay for assessing antivenoms. | dilutions of antivenom, venom, human erythrocytes and a phosphatidylcholine suspension, were incubated for 30 min at 37 degrees c. after centrifugation, the liberated haemoglobin was measured spectrophotometrically. the assay was used to assess an ovine antivenom against the venom from the south american rattlesnake, crotalus durissus terrificus, and an equine wyeth antivenin (crotalidae, polyvalent). the ovine antivenom was more than five times as effective as the equine product. it also neutra ... | 1991 | 1949062 |
| specific binding of crotoxin to brain synaptosomes and synaptosomal membranes. | crotoxin, the presynaptic neurotoxin from crotalus durissus terrificus, was iodinated and used to demonstrate high affinity, specific binding to guinea-pig (cavia porcellus) brain synaptosomes and synaptosomal membrane fragments. 125i-crotoxin binding to the membrane fragments displays two binding plateaus, (kd1 = 4 nm and kd2 = 87 nm, bmax1 = 2 and bmax2 = 4 pmoles/mg membrane protein), but binding to whole synaptosomes revealed only one plateau (kd = 2 nm and bmax = 5 pmoles/mg membrane protei ... | 1991 | 1949068 |
| protection against the lethal effects of crotalus durissus terrificus (south american rattlesnake) venom in animals immunized with crotoxin. | mice and rabbits were immunized against crotoxin (the neurotoxic component isolated from crotalus durissus terrificus venom) using small amounts of antigen in a water-in-oil emulsion. following boosting (three times at 21-day intervals) a high titre of antibodies against crotoxin was obtained. crotoxin immunoglobulin g antibody recognizes whole venom antigen at a level comparable with that of crotoxin antigen, using the elisa method for antibody detection. the antibodies generated by crotoxin we ... | 1990 | 2128567 |
| acute myocardial infarction-like enzyme profile in human victims of crotalus durissus terrificus envenoming. | the clinical signs and symptoms of crotalus durissus terrificus envenoming are due to the neurotoxic, myotoxic systemic and thrombin-like coagulating effects of the venom. the rhabdomyolysis observed after envenoming caused by snakes, the venom of which has a systemic myotoxic activity, has been limited thus far to skeletal muscle, with no reports of myocardial damage. in the present paper we report serial measurements of serum creatine kinase (ck), lactic dehydrogenase (ld) and of ck-mb and ld1 ... | 1990 | 2260185 |
| comparison of the immunogenicity and antigenic composition of several venoms of snakes in the family crotalidae. | crude venoms from the prairie rattlesnake (crotalus viridis viridis), the western diamondback rattlesnake (crotalus atrox), the eastern diamondback rattlesnake (crotalus adamanteus) and the timber rattlesnake (crotalus horridus horridus) were used to prepare monovalent antivenoms in rabbits. each of these four monovalent antivenoms was reacted against six different venoms using the technique of immunoblotting (western blot) to determine the relative immunogenicity of the four venoms and to compa ... | 1990 | 2339435 |
| effects of crotoxin on the isolated guinea pig heart. | the effects of crotoxin, isolated from the venom of the south american rattlesnake, crotalus durissus terrificus, were investigated on isolated guinea pig hearts, perfused with locke solution, by the langendorff method. the cardiac beats and the electrocardiogram were simultaneously registered and the creatine kinase (ck) activity of the perfusate measured. crotoxin was infused (4.5 x 10(-8) m and 2.3 x 10(-7) m) into the heart during 90 min, and induced a remarkable decrease in the contractile ... | 1990 | 2339436 |
| cloning and nucleotide sequences of crotamine genes. | a cdna library containing snake toxin genes was constructed in bacteriophage lambda by using mrna isolated from the glands of the south american rattlesnake, crotalus durissus terrificus. the first high-density screening of 400,000 plaques for crotamine-containing genes yielded over 800 positives when a labeled cdna probe with sequence homology to crotamine was used. four of these clones with insert sizes from 270 to 400 base pairs were chosen and their inserts subcloned into pgem-3z and sequenc ... | 1990 | 2389256 |
| human ss-b/la autoantigen contains a covalent protein-rna linkage. | the chemical nature of association of rna in immunoprecipitates of human ss-b/la ribonucleoprotein, an autoantigen expressed in various autoimmune disorders, was investigated. a fraction of rna associated with ss-b/la immunoprecipitates was readily dissociated by sds-polyacrylamide gel electrophoresis, yielding four main subfractions, r1-4, with chain lengths in the range of 90-130 nucleotides (r4), 140-175 nucleotides (r2 and r3) and above 200 nucleotides (r1). moreover, the immunoreactive prot ... | 1987 | 2441750 |
| cross-neutralization on the histamine-releasing activity of snake venoms. | this paper investigates the neutralizing effect of crotalic and bothropic antivenoms on the histamine-releasing activity of three different brazilian snake venoms (crotalus durissus terrificus, bothrops jararacussu and bothrops alternatus). this relative histamine-releasing activity was determined on peritoneal mixed cells of rats. c. d. terrificus venom was the most efficient histamine-releasing agent (ed50 = 1.25 micrograms/ml) followed by b. jararacussu (ed50 = 1.97 ug/ml) and b. alternatus ( ... | 1989 | 2485182 |
| south american rattlesnake venom: its hemolytic power. | the hemolytic power of rattlesnake venom (crotalus durissus terrificus) was studied. a high percentage of sample with negative hemolytic power was detected when sheep red blood cells were used. a large number of venoms with hemolytic power, though with a low hemolysis percentage, were detected when liquid, recently extracted venom was used. when crystallized venom was used under the same experimental conditions, a higher percentage of positivity for hemolysis was obtained. when the results obtai ... | 1989 | 2487773 |
| convulxin does not induce convulsions when injected into the rat dorsal hippocampus. | the search for new and selective neurotoxins has attracted several efforts in the recent years. convulxin, a neurotoxin isolated from the crotalus durissus terrificus venom, was reported to elicit convulsions upon intravenous injection in mice and cats. therefore we have studied the behavioral, electroencephalographic and neuropathological effects of convulxin when microinjected into the dorsal hippocampus of rats. to test the hypothesis that substances released by convulxin from platelets and n ... | 1989 | 2520356 |
| the effect of crotoxin on the longitudinal muscle-myenteric plexus preparation of the guinea pig ileum. | the effects of crotoxin, the neurotoxin of the venom of the south american rattlesnake (crotalus durissus terrificus), was studied by using the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum. crotoxin (0.02-4.0 microm) caused depression of the twitch response of the electrically stimulated preparation. this transitory depression depended on the concentration of crotoxin; since crotoxin diminished the output of acetylcholine, this depression may be due to the inhibition ... | 1989 | 2548113 |
| effect of metronidazole on platelet aggregation. | the effects of metronidazole on platelet aggregation induced by several agonists were studied on guinea pig and human platelet-rich plasma. metronidazole (0.25-2.5 mg/ml) showed a dose-dependent inhibitory effect on in vitro aggregation of platelets from either source induced by adenosine-5-diphosphate (adp), platelet aggregating factor (paf), epinephrine, collagen or convulxin (extracted from crotalus durissus terrificus venom). total or partial inhibition was also detected in metronidazole pre ... | 1989 | 2641356 |
| behavioural, electroencephalographic and neuropathological effects of the intrahippocampal injection of the venom of the south american rattlesnake (crotalus durissus terrificus). | venom was microinjected into the dorsal hippocampus of rats and electroencephalographic recordings were obtained from the hippocampus and occipital cortex. behavioural alterations consisted of circling, wet shaking and scratching that evolved to head and body jerks and isolated clonic episodes and then to wild running followed by tonic-clonic generalized seizures and status epilepticus. electroencephalographic alterations consisted of high frequency and high voltage spikes together with epilepti ... | 1989 | 2718190 |
| purification of f(ab')2 anti-snake venom by caprylic acid: a fast method for obtaining igg fragments with high neutralization activity, purity and yield. | pooled horse plasma containing antibodies against crotalus durissus terrificus whole venom were digested with pepsin at an enzyme-substrate ratio of 8:1, ph 3.1, for 40 min and the f(ab')2m fragments purified by adding 8.7% caprylic acid (ph 5.0). for comparison, f(ab')2b purified by precipitation with ammonium sulphate and uncleaved igg purified with caprylic acid were also prepared. fab' fragments were obtained by reduction and alkylation of f(ab')2b. the anti-whole c.d. terrificus venom titer ... | 1989 | 2728022 |
| use of liposomes for protective immunisation against crotalus durissus (tropical rattlesnake) venom. | crotalus durissus venom has been described as a weak antigen when injected in combination with freund's complete adjuvant during the course of traditional methods of equine immunisation. antibody production is slow and unpredictable, with a wide variation in individual responses. in this experimental study, c. durissus venom was incorporated into stabilised sphingomyelin-cholesterol liposomes both in the presence and absence of lipopolysaccharide immunostimulant and injected by both i.v. and s.c ... | 1989 | 2728026 |
| raman and infrared studies on the conformation of porcine pancreatic and crotalus durissus terrificus phospholipases a2. | raman and infrared spectroscopies were used to investigate conformational features of crotalus durissus terrificus and porcine pancreatic phospholipases a2, as well as the proenzyme of the latter. the results indicate that conformational changes occur for the phospholipase molecules as a consequence of different experimental conditions such as change of physical state, presence of certain ionic species and interaction with a model substrate analog. amorphous and crystalline solid phospholipase p ... | 1989 | 2752052 |
| a gyroxin analog from the venom of the bushmaster (lachesis muta muta). | clinical observations of possible neurotoxic activity in bushmaster (lachesis muta muta) envenomations, coupled with the accepted ancestral relationship of lachesis to other crotalids, suggested that lachesis venom might contain a crotoxin-like molecule. crude venom and gel-filtration fractions showed modest reactivity in enzyme-linked immunosorbent assays using rabbit polyclonal antibodies raised against the basic subunit of crotoxin, but no reaction was detected with a murine monoclonal antibo ... | 1989 | 2781576 |
| comparative study on coagulant, defibrinating, fibrinolytic and fibrinogenolytic activities of costa rican crotaline snake venoms and their neutralization by a polyvalent antivenom. | the coagulant, defibrinating, fibrino lytic and fibrinogenolytic activities of venoms from ten species of costa rican crotaline snakes were studied, together with the neutralization of these effects by a polyvalent antivenom. the venoms of bothrops asper, b. schlegelii, b. nummifer, b. godmani, lachesis muta and crotalus durissus induced a coagulant effect in vitro, and all of them, with the exception of b. nummifer, also induced defibrination in vivo. the four non-coagulant venoms (b. lateralis ... | 1989 | 2781583 |
| neutralization of lethal and myotoxic activities of south american rattlesnake venom by extracts and constituents of the plant eclipta prostrata (asteraceae). | ethanolic extracts of the aerial parts of eclipta prostrata l. (asteraceae) neutralized the lethal activity of the venom of south american rattlesnake (crotalus durissus terrificus) when mixed in vitro before i.p. injection into adult swiss mice. samples of ethanolic extract corresponding to 1.8 mg of dry extract per animal neutralized up to four lethal doses of the venom (ld50 = 0.08 micrograms venom/g animal). three substances isolated from the plant--wedelolactone (0.54 mg/animal), sitosterol ... | 1989 | 2799833 |
| unusual neurological symptoms in a case of severe crotalid envenomation. | in sweden bites by non-european venomous snakes are reported to the poison information centre 5-10 times annually. these incidents generally take place in private homes and may result in severe poisoning. we report a recent case of envenomation from a bite by crotalus durissus terrificus with a prolonged, atypical course. the patient, a 24-year old man, was admitted to hospital approximately eight hours after the snakebite. on admission we noted coma, circulatory failure, hypofibrinogenaemia wit ... | 1985 | 2997459 |
| effects of crotoxin on autonomic neuromuscular transmission in the guinea-pig myenteric plexus and vas deferens. | the effects of crotoxin, the neurotoxic complex from the venom of the south american rattlesnake crotalus durissus terrificus on mammalian autonomic neuromuscular transmission, have been investigated. in the longitudinal muscle of the guinea-pig ileum, crotoxin induced a dose-dependent contraction which was followed by relaxation, in spite of the continued presence of the toxin. the contractile response was inhibited by indomethacin, tetrodotoxin, verapamil or nifedipine, but was unaffected by a ... | 1985 | 3006284 |
| cross-reactivity and neutralization by rabbit antisera raised against crotoxin, its subunits and two related toxins. | antisera were raised against intact crotoxin (crotalus durissus terrificus), mojave toxin (crotalus scutulatus scutulatus) and concolor toxin (crotalus viridis concolor), as well as the subunits of crotoxin. double immunodiffusion and enzyme-linked immunosorbent assays (elisa) demonstrated antigenic similarity between these three purified toxins and their subunits. additionally, when crotoxin antisera were pre-incubated with each of the three toxins before injection, the lethal activity of all w ... | 1986 | 3095955 |
| a crotoxin homolog from the venom of the uracoan rattlesnake (crotalus vegrandis). | a major protein toxin from the venom of crotalus vegrandis was examined by gel filtration, anion-exchange chromatography, and sds polyacrylamide gel electrophoresis. the toxin was separated into several isoforms by ion-exchange chromatography and spontaneously dissociated into free acidic and basic subunits, mimicking the behavior of crotoxin. rabbit antisera raised against crotoxin reacted strongly in enzyme-linked immunosorbent assays with the intact c. vegrandis toxin isoforms and their basic ... | 1987 | 3122371 |
| evidence that crotalus durissus terrificus (south american rattlesnake) envenomation in humans causes myolysis rather than hemolysis. | the venom of the south american rattlesnake crotalus durissus terrificus was originally reported to have a pathophysiological activity mainly involving hemolysis and neurotoxicity. the systemic myotoxic action of this venom was demonstrated in 1985. in the present paper we report clinical and laboratory data concerning three patients bitten by c. durissus terrificus and treated at the university hospital of ribeirão preto, university of são paulo. the normal haptoglobin levels detected in the se ... | 1987 | 3124296 |
| generation of protective immune sera by crotalus durissus terrificus venom detoxified by controlled iodination. | 1. whole soluble venom from the snake crotalus durissus terrificus was detoxified by controlled iodination. doses equivalent to 100 ld50 of the native venom were administered to mice, without signs of intoxication. 2. the non-toxic iodinated derivatives were able to stimulate antibodies in rabbits and horses within a short period (6 months) of immunization. horse antisera attained titers of 0.5 to 0.9 mg/ml for protection against native venom. 3. horse antisera obtained in horses from native and ... | 1987 | 3137988 |
| [reproductive biology of the central american rattlesnake crotalus durissus durissus (serpentes: viperidae) in costa rica]. | in costa rica, rattlesnakes mate during the early dry season (december and january) and births occur in the early rainy season (may-july). gestation is therefore about 6 months. the mean number of offspring is 22.9 and is significantly correlated with the size of the female. newborn rattlesnakes are 27.5-43.0 cm in length and weight 11.4-46.3 g. they are relatively docile. adult males are longer and heavier than females. females seem to have their first litter when their size exceeds 120 cm. | 1988 | 3238074 |
| isolation and characterization of a thrombin-like enzyme from the venom of crotalus durissus terrificus. | a thrombin-like enzyme was isolated in 6% yield from the venom of crotalus durissus terrificus by ammonium sulfate precipitation followed by gel filtration on sephadex g-75 and finally affinity chromatography on sepharose-1,4-butanediol-diglycyl-p-aminobenzamide eluted with 0.15 m benzamidine. the enzyme behaved like a single component on sds-page corresponding to a molecular weight of 34 kda. the specific activity of the enzyme toward bovine fibrinogen was 71 nih u/mg protein. the ph optimum fo ... | 1986 | 3594000 |
| isolation and characterization of the alpha and beta subunits of the platelet-activating glycoprotein from the venom of crotalus durissus cascavella. | it was concluded in a previous paper that the high mr platelet-activating glycoprotein isolated earlier from the venom of crotalus durissus cascavella has an hexameric structure of the alpha 3 beta 3 type involving two distinct subunits. data reported here demonstrate that these two subunits are separable from each other by ion exchange chromatography under denaturating conditions, have similar mrs (alpha = 12,540 et beta = 13,770) and exist in a one to one ratio within the native molecule. carb ... | 1985 | 3938295 |
| immunogenic response of the venoms of fer-de-lance, bothrops atrox asper, and la cascabella, crotalus durissus durissus, following photooxidative detoxification. | | 1968 | 4170736 |
| [a comparison of the neuromuscular action of crotamine and the venom of crotalus durissus terrificus var. crotaminicus. 1. neuromuscular preparations in situ]. | | 1971 | 5092394 |
| [a comparison of the neuromuscular action of crotamine and the venom of crotalus durissus terrificus var. crotaminicus. 2. isolated preparations]. | | 1971 | 5092395 |
| [neuromuscular effects of venoms from 2 varieties of crotalus durissus terrificus]. | | 1969 | 5348398 |
| [new species of ophidascaris (baylis 1921), parasite of the crotalus snake (crotalus durissus terrificus)]. | | 1969 | 5393011 |
| pharmacology of crystalline crotoxin. 3. cardiovascular and respiratory effects of crotoxin and crotalus durissus terrificus venom. | | 1966 | 6002983 |
| chromatographic separation of phospholipase a from a histamine releasing component of brazilian rattlesnake venom (crotalus durissus terrificus). | | 1967 | 6070461 |
| a study on the membrane depolarization of skeletal muscles caused by a scorpion toxin, sea anemone toxin ii and crotamine and the interaction between toxins. | quinquestriatus toxin (qtx) isolated from the venom of a scorpion (leiurus quinquestriatus) and sea anemone (anemonia sulcata) toxin ii enhanced the twitch response of the rat and mouse diaphragms and like crotamine (isolated from the venom of crotalus durissus terrificus) caused spontaneous fasciculation of the muscle. trains of action potentials in muscles at 70-250 hz, which could not be antagonized by (+)-tubocurarine, were triggered by single stimulation or occurred spontaneously after trea ... | 1983 | 6197125 |
| crotoxin. i. immunology and interaction of the subunits. | p6ospholipase a and crotapotin were purified by gel filtration and ion-exchange chromatography from crotalus durissus terrificus venom. the minimal molecular weights obtained by amino acid analysis were 13,400 daltons for phospholipase a and 8,300 daltons for crotapotin. phospholipase a and crotapotin form a 1:1 molar complex that was stable during gel filtration. the ld50 of phospholipase a was increased about 10-fold when in a 1:1 complex with crotapotin. crotapotin, phospholipase a and crotox ... | 1984 | 6518335 |
| local necrotizing effect of snake venoms on skin and muscle: relationship to serum creatine kinase. | twenty-five snake venoms were tested for their ability to induce an increase of serum creatine kinase (ck) level after i.m. injection (0.125-1.0 mg/kg) into rates. of six australian elapid venoms only those from pseudechis colletti guttatus and p. australis produced a steep rise of ck-activity (30-70 times the normal value) 4 and 16 hr after injection (0.5 mg/kg). viperid and crotalid venoms had only slight effects (2-5 times the normal value) even in doses of 1.0 mg/kg except for a sample of cr ... | 1983 | 6623487 |
| detection of common antigenic sites in lethal proteins of non-related animal venoms. | monoclonal antibodies neutralizing specific coelenterate lethal toxins were used to determine the presence of homologous antigenic sites on toxin proteins of a rattlesnake (crotalus durissus terrificus), a hornet (vespa orientalis) and the sea wasp (chironex fleckeri). an anti-portuguese man-o'war toxin antibody was found useful for isolating a c. d. terrificus toxin. | 1983 | 6623490 |
| i--isolation and electron microscope studies of a potent platelet-aggregating glycoprotein from the venom of crotalus durissus cascavella. | a potent acid-soluble platelet-aggregating glycoprotein was purified from the venom of crotalus durissus cascavella by molecular sieve chromatography on sephadex g-75 and by adsorption onto sepharose 4b gels at acidic ph. this new protein with an apparent mr of 300,000 at acidic ph and containing a low amount of sugars is non-toxic for mice. electron microscope studies showed that the platelet-aggregating glycoprotein appeared as regular rosettes of 150 a in diameter at acidic ph and underwent p ... | 1983 | 6626587 |
| convulxin-induced activation of intact and of thrombin-degranulated rabbit platelets: specific crossed desensitisation with collagen. | the aggregation of plasma-free rabbit platelets induced by convulxin (cx), a glycoprotein extracted from the venom of crotalus durissus cascavella was accompanied by the secretion of atp and by the formation of thromboxane a2 (txa2) and of 'platelet-activating factor' (paf-acether). thrombin-induced exhaustion of the pool of releasable adp, or inactivation of cyclooxygenase with aspirin or with arachidonic acid failed to suppress cx-induced activation. electron microscopy studies showed that pla ... | 1983 | 6628537 |
| subunit structure of a potent platelet-activating glycoprotein isolated from the venom of crotalus durissus cascavella. | the potent platelet-activating factor isolated from the venom of crotalus durissus cascavella is an acid-soluble multisubunit glycoprotein of mr 72,000 built up of two types of subunits, alpha and beta, linked by disulphide bonds. the mean apparent mr of the reduced complex was around 12,000 by gel filtration under denaturating conditions. the mrs of the alpha and beta subunits, with an apparent ratio of 1/1, were 12,600 and 13,580 by sds-page respectively. the mr 72,000 glycoprotein is thought ... | 1983 | 6673741 |
| specificity of antibodies to the reconstituted crotoxin complex, from the venom of south american rattlesnake (crotalus durissus terrificus), using enzyme-linked immunosorbent assay (elisa) and double immunodiffusion. | | 1981 | 6784278 |
| [resistance of crotalus durissus terrificus and bothrops neuwiedii to the neurotoxicity of massive quantities of crotalid venom]. | the antitoxic potency of crude crotalus durissus terrificus serum against crotalic venom is similar to that of a standard horse anticrotalic serum in protecting mice against 4 ld50, while the potency of bothrops neuwiedii serum is 20% of the latter. failure to form precipitin lines in immunodiffusion tests suggests that the antitoxic factors present in the sera from both species are not immunoglobulins. it is, therefore, probable that crotoxin is not neutralized by an antigen-antibody reaction, ... | 1982 | 6820610 |
| activation of guinea-pig platelets induced by convulxin, a substance extracted from the venom of crotalus durissus cascavella. | convulxin (cx), a component of the venom of the snake crotalus durissus cascavella, induced the concentration-dependent aggregation of guinea-pig platelets when used at and above 50 +/- 5 ng/ml, accompanied by the release of atp and by the formation of thromboxanes (tx). platelet activation by cx was not due to potential contaminants found in the crude snake venom, such as phospholipase a2 and clotting enzymes. aspirin (50-100 microm) failed to interfere with the platelet effects of cx, demonstr ... | 1980 | 7009169 |
| titration of antiserum to south american rattlesnake (crotalus durissus terrificus) venom by measuring inhibition of phospholipase a2 activity. | horse antiserum to the venom of crotalus durissus terrificus, a south american rattlesnake, inhibits the phospholipase activity of the crude venom. there is a close relationship between this inhibitory property and the neutralizing potency of the antiserum in vivo. this may provide the basis for a rigorous standardization of anticrotalid venom in vitro. | 1982 | 7101307 |
| convulxin, a new toxin from the venom of the south american rattlesnake crotalus durissus terrificus. | | 1981 | 7336450 |
| afibrinogenemia following snake bite (crotalus durissus terrificus). | following the bite of crotalus durissus terrificus, an 11-year-old boy developed afibrinogenemia and high output acute renal failure. his platelet count remained within normal limits. he was treated with epsilon aminocaproic acid and whole fresh blood transfusion, with full recovery from afibrinogenemia 40 hours after the beginning of these measures and 75 hours after the snake bite. no hemorrhagic disturbances were present. the acute renal failure was treated conservatively, and the patient rec ... | 1980 | 7446831 |
| continuous measurement of phospholipase a2 activity using the fluorescent probe adifab. | a new method is described for the continuous quantitation of phospholipase a2 (pla2) activity with greatly improved sensitivity compared to existing techniques. the method utilizes a fluorescent probe to detect the release of fatty acid monomers (free fatty acids) into the aqueous phase. the fluorescent probe adifab, which is the acrylodan derivative of rat intestinal fatty acid binding protein, exhibits a change in the ratio of its fluorescence upon binding medium- to long-chain native fatty ac ... | 1995 | 7485980 |
| liver dysfunction in patients bitten by crotalus durissus terrificus (laurenti, 1768) snakes in botucatu (state of são paulo, brazil). | thirty-two patients bitten by venomous snakes sixteen by bothrops spp. and sixteen by crotalus durissus terrificus were studied. the group comprised thirty males and two females, aged eight to sixty-three years (mean 33 +/- 15). bromsulphalein tests were increased in the majority of patients bitten by crotalus durissus terrificus. the correlation coefficient of spearman was positive between bromsulphalein tests and alanine aminotransferase levels, and between alanine aminotransferase and asparta ... | 1995 | 7569642 |
| ammodytoxin a acceptor in bovine brain synaptic membranes. | ammodytoxin a, the presynaptic neurotoxin from vipera ammodytes ammodytes venom, was found to bind specifically and with high affinity to bovine cortex synaptic membrane preparation. the detected ammodytoxin a high-affinity binding was characterized by equilibrium binding analysis which revealed a single high-affinity binding site with kd 4.13 nm and bmax 6.67 pmoles/mg of membrane protein. 125i-ammodytoxin a was covalently cross-linked to its neuronal acceptor using a chemical cross-linking tec ... | 1995 | 7570629 |
| effect of saponin from quillaja saponaria (molina) on antibody, tumour necrosis factor and interferon-gamma production. | saponin has been described to contain adjuvant activity in vaccination protocols, in protection against disease, and on humoral immune response. in this paper we describe the effect of a pure saponin from quillaja saponaria (molina) on the immune response elicited in mice by two antigens, bsa and crotalus durissus terrificus (south american rattlesnake) venom. antibody production as measured by elisa shows that saponin was able to increase antibody synthesis to both antigens. moreover, mice immu ... | 1995 | 7576254 |
| a comparison of ovine and equine antivenoms. | commercial antivenoms produced in horses were compared with monospecific antivenoms raised in sheep against crotalus durissus terrificus, crotalus atrox, crotalus adamanteus, micrurus fulvius fulvius, naja naja, naja kaouthia, echis ocellatus, vipera lebetina deserti, vipera berus berus and vipera ammodytes ammodytes venom. antibodies raised by immunizing sheep with c. d. terrificus venom were more effective than their equine counterparts in preventing lethal toxicity in mice (ed50), in inhibiti ... | 1994 | 8052997 |
| crotoxin induces aggregation of human washed platelets. | crotoxin, the main toxic component isolated from the venom of the south american rattlesnake crotalus durissus terrificus, is a reversible protein complex composed of a non-toxic non-enzymatic acidic polypeptide (crotapotin) and a toxic basic phospholipase a2 (pla2). in this study, we have evaluated the ability of crotoxin to induced aggregation in human washed platelets. human washed platelet aggregation was monitored in a payton aggregometer and thromboxane b2 (txb2) release measured by direct ... | 1994 | 8153961 |
| cysteine-specific adp-ribosylation of actin. | incubation of lysate from human polymorphonucleated neutrophils and human platelets with [32p]nad resulted in the labeling of a 42-kda protein. phosphodiesterase (crotalus durissus) released 5'-amp from the radiolabeled protein. the 42-kda protein was identified as actin by binding to dnase-i, two-dimensional gel electrophoresis and partial proteolysis. the rate of adp-ribosylation was greater with [32p]adp-ribose than with [32p]nad, indicating a non-enzymic modification. adp-ribose also modifie ... | 1994 | 8181461 |
| a phospholipase a2 inhibitor from the plasma of the south american rattlesnake (crotalus durissus terrificus). protein structure, genomic structure, and mechanism of action. | the lethal toxicity of the south american rattlesnake (crotalus durissus terrificus) venom can be attributed mainly to the presence of a pre-synaptic neurotoxin, crotoxin, with phospholipase a2 activity. crotoxin is a heterodimer of an acidic protein (ca) and a basic phospholipase a2 (cb). an anti-toxic protein of subunit molecular mass 23.6 kda that neutralizes both lethal and pla2 activity of crotalid venom and crotoxin has been previously purified from the plasma of this snake (fortes-dias, c ... | 1994 | 8195214 |
| comparison of the immunogenicity and antigenic composition of ten central american snake venoms. | the immunological reactivity of five crotaline antivenoms for the venoms of ten costa rican snakes was determined. venoms from bothrops asper, b. godmani, b. lateralis, b. nasutus, b. ophryomegas, b. schlegelii, b. nummifer, b. picadoi, crotalus durissus durissus and lachesis muta stenophrys were separated by sds-page, transferred to cellulose nitrate membrane and reacted against five different antivenoms. antisera used in the immunoblotting were prepared in rabbits to the crotaline venoms from ... | 1993 | 8212043 |
| oedema formation and degranulation of mast cells by phospholipase a2 purified from porcine pancreas and snake venoms. | phospholipase a2 is ubiquitous in nature, with the highest concentrations occurring in pancreatic juice and in the venom of snakes. local oedema formation is a common feature of the effects caused by snakebite, and indicates an increase in vascular permeability that could be produced by lipid mediators such as lysophospholipids, eicosanoids or paf release by the enzymatic activity of pla2. desalted porcine pancreatic pla2 exhibited strong oedema-inducing activity in a similar form to pla2 venom ... | 1993 | 8212047 |
| [evaluation in mice of the efficacy of antivenins administered at the site of the intramuscular inoculation of the crotalus durissus terrificus venom]. | the efficacy of the crotalus durissus terrificus antivenom administration by intramuscular (im) injection at the same place of the im inoculation, of the c. d. terrificus venom was evaluated in mice. in three experiments two dl50 of the venom were inoculated and the antivenom was administered in three different ways: half of the ed50 by intraperitoneal (ip) administration and half by injection, at the same place, immediately after the venom inoculation and thirty minutes after the im venom inocu ... | 1993 | 8278742 |
| [characterization of the biological activities of the 'yellow' and 'white' venoms from crotalus durissus ruruima compared with the crotalus durissus terrificus venom. neutralizing activity of crotalus durissus ruruima antivenins]. | the biological activities of 'yellow' and 'white' venom of a rattlesnake crotalus durissus ruruima hoge, 1965, found in the savanna-like vegetation (cerrado) of northern brazil (roraima) and venezuela have been studied, and compared to the reference crotalus durissus terrificus venom. the lethal activity of venoms depended on the inoculation route. the most toxic venom was the white one. the venoms of c. d. terrificus and the yellow of c. d. ruruima had similar lethalities. the yellow venom of c ... | 1993 | 8310446 |
| comparison of crotoxin isoforms reveals that stability of the complex plays a major role in its pharmacological action. | crotoxin from the venom of the south american rattlesnake crotalus durissus terrificus is a potent neurotoxin consisting of a weakly toxic phospholipase-a2 subunit (cb) and a non-enzymic, non-toxic subunit (ca). crotoxin complex (cacb) dissociates upon interaction with membranes: cb binds while ca does not. moreover, ca enhances the toxicity of cb by preventing its non-specific adsorption. several crotoxin isoforms have been identified. multiple variants of each subunit give different crotoxin c ... | 1993 | 8513799 |
| detoxified venom from crotalus durissus terrificus is devoid of cytotoxic activity and induces mitogenesis. | the venom from the snake crotalus durissus terrificus was detoxified by stepwise incorporation of stable cationic iodine. the venoid, in a dosage equivalent to 100 ld50 of the lethal venom, was injected in mice without lethal exits. the native venom (nat), or its toxoided (txd) derivative were incubated in presence or absence of mitogens, with human mononuclear (mn), b and t cells, with a pulse of [3h]thymidine. no synergistic or antagonistic effects were observed in the combined activity of the ... | 1995 | 8537613 |
| determination of the neutralizing potency of horse antivenom against bothropic and crotalic venoms by indirect enzyme immunoassay. | the use of elisa to determine antisnake venom potency of horse immune sera should provide benefits of costs and reproducibility compared to in vivo assays. in the present investigation we evaluated the correlation between elisa antibody levels and in vivo neutralization assays. for the indirect elisa method, 0.016 micrograms/well of bothrops jararaca or crotalus durissus terrificus venom were used to coat the plates and 100 microliters/well of each sample of antibothropic or anticrotalic venom s ... | 1995 | 8634680 |
| [neuromuscular action of crotalid venoms: preliminary data]. | we studied 6 patients and 2 dogs that have been bitten by south american rattlesnake crotalus durissus terrificus and one rabbit inoculated with crotalid venom. we analyzed sensory and motor peripheral nerve conduction, repetitive stimulation for studying neuromuscular transmission and electromyographies. muscle biopsies were processed by histochemistry. all patients had peripheral mononeuropathy of the closest sensitive nerve to the area of snakebite. the neuromuscular transmission alterations ... | 1996 | 8736137 |
| native peptide inhibition. specific inhibition of type ii phospholipases a2 by synthetic peptides derived from the primary sequence. | the binding of low molecular weight type ii phospholipase a2 (ec) to membrane surfaces and hydrolysis of phospholipid are thought to involve the formation of a hydrophobic channel into which a single substrate molecule diffuses before cleavage. the floor and right side of the channel are provided by hydrophobic residues 2, 5, and 9 of an amphipathic amino-terminal helix. the channel is postulated to form via a conformational change in this helix and inward movement of a hydrophobic flap (residue ... | 1996 | 8798633 |
| characterization of paramyxoviruses isolated from three snakes. | multiple epizootics of pneumonia in captive snakes have been attributed to viruses which have been tentatively placed in the family paramyxoviridae. viruses isolated from an ill neotropical rattlesnake (crotalus durissus terrificus), from an aruba island rattlesnake (crotalus unicolor), and from a bush viper (atheris sp.) were propagated in vero cells and characterized. viral particles produced in vero cells were pleomorphic, enveloped, and contained helical nucleocapsids. the viruses were sensi ... | 1996 | 8822636 |
| encapsulation of native crotoxin in liposomes: a safe approach for the production of antivenom and vaccination against crotalus durissus terrificus venom. | crotoxin, the neurotoxic component of crotalus durissus terrificus (cdt) venom that displays phospholipase a2 activity, was successfully encapsulated into dehydration-rehydration vesicles (drv/crotoxin) and reverse-phase evaporation vesicles (rev/crotoxin) made from sphingomyelin and cholesterol. the encapsulation efficiency of native crotoxin was higher in drv/crotoxin than in rev/crotoxin. drv/crotoxin was not toxic when i.v. inoculated in mice at a dose of crotoxin as high as 91 times its l.d ... | 1997 | 9028012 |
| crotoxin-induced behavioral effects in rats. | crotoxin is the major component of crotalus durissus terrificus venom. in view of the presence of high-affinity specific binding sites for crotoxin in the brain, the objective of this work was to investigate whether crotoxin induces behavioral effects in the open-field and hole-board tests. adult male wistar rats (180-220 g) treated with crotoxin, 100, 250 and 500 micrograms/kg, ip, administered 2 h before the test, presented statistically significant behavioral alterations (anova for one-way cl ... | 1996 | 9033813 |
| an enzyme-linked immunosorbent assay (elisa) that discriminates between the venoms of brazilian bothrops species and crotalus durissus. | enzyme-linked immunosorbent assays (elisas) were developed to detect specific antigens from bothrops sp. and crotalus durissus snake venoms in brazil. cross-reactive immunoglobulins from hyperimmune horse anti-bothrops and anti-crotalus sera were removed by immunoaffinity chromatography. specific iggs for bothrops sp. and c. durissus venom antigens were prepared and used to set up a sandwich-type elisa. the specificity of the assay was demonstrated by its capacity to identify correctly the circu ... | 1997 | 9080582 |
| effect of crotalus venom on the humoral and cellular immune response. | the effect of venom of south american rattlesnake crotalus durissus terrificus (cdt) on the humoral and cellular immune response was studied in balb/c mice that were immunized with soluble antigens [human serum albumin (hsa) or chicken ovoalbumin (ova)] or sensitized to dnfb 1 hr after venom injection. pretreatment of the animals with cdt venom induced a significant reduction in the level of anti-ova and anti-hsa igg antibodies. the effect of crotoxin, a major neurotoxic component of cdt venom, ... | 1997 | 9133715 |
| platelet activation and signal transduction by convulxin, a c-type lectin from crotalus durissus terrificus (tropical rattlesnake) venom via the p62/gpvi collagen receptor. | convulxin, a powerful platelet activator, was isolated from crotalus durissus terrificus venom, and 20 amino acid n-terminal sequences of both subunits were determined. these indicated that convulxin belongs to the heterodimeric c-type lectin family. neither antibodies against gpib nor echicetin had any effect on convulxin-induced platelet aggregation showing that, in contrast to other venom c-type lectins acting on platelets, gpib is not involved in convulxin-induced platelet activation. in add ... | 1997 | 9153205 |
| biologically active human anti-crotoxin scfv isolated from a semi-synthetic phage library. | the display of repertoires of antibody fragments on the surface of filamentous bacteriophages offers a new way of making antibodies with predefined binding specificities. | 1997 | 9237096 |
| convulxin, a potent platelet-aggregating protein from crotalus durissus terrificus venom, specifically binds to platelets. | convulxin, a very potent aggregating protein from rattlesnake venom, was purified by a new procedure and its heterodimeric structure alpha 3 beta 3 was confirmed. the polypeptide n-terminal sequences of convulxin subunits were determined by edman degradation. they are very similar and appear homologous to botrocetin from bothrops jararaca venom and to rattlesnake lectin from crotalus atrox venom, both being classified among the c-type lectin family. the binding of 125i-labelled convulxin to bloo ... | 1997 | 9278971 |
| adhesion and activation of human platelets induced by convulxin involve glycoprotein vi and integrin alpha2beta1. | we analyzed the interaction of convulxin (cvx), a 72-kda protein isolated from the venom of crotalus durissus terrificus, with human platelets. cvx is a potent platelet agonist that induces an increase in the intracellular ca2+ concentration ([ca2+]i), granule exocytosis and aggregation. 125i-labeled cvx binds specifically and rapidly to platelets at binding sites of high and moderate affinity. platelets adhere to immobilized cvx in a time-dependent but cation-independent manner. platelet exocyt ... | 1997 | 9341142 |
| identification of diphtheria toxin via screening as a potent cell cycle and p53-independent cytotoxin for human prostate cancer therapeutics. | metastatic human prostate cancer requires novel therapeutic strategies in order to overcome its low proliferative rate and its resistance to conventional chemotherapeutic agents. to identify potential cytotoxin gene products for use in experimental therapeutics such as in vivo gene therapy, an in vitro screen was designed. | 1998 | 9496900 |
| [hemorrhage induced by snake venoms in argentina]. | mice of 18 and 20 g were injected intradermally with 0.1 ml of serial dilution of venom in saline solution 0.9 buffered ph 7.2. groups of 4 animal were formed, they were sacrificed 2 hours after inoculation. skin of every mouse was put out, and the haemorrhagic area was measured bothrops alternatus, bothrops jararaca, bothrops jararacussu and bothrops neuwiedii venoms were used. crotalus durissus terrificus did not show any haemorrhagic activity. | 1997 | 9580123 |
| convulxin induces platelet activation by a tyrosine-kinase-dependent pathway and stimulates tyrosine phosphorylation of platelet proteins, including plc gamma 2, independently of integrin alpha iib beta 3. | 1convulxin (cvx) is a well-characterized platelet aggregating glycoprotein isolated from crotalus durissus terrificus and c. d. cascavella venoms. in the present report we show that cvx induces tyrosine phosphorylation of human platelet proteins, including phospholipase c-gamma 2 (plc gamma 2), and also stimulates [3h]arachidonic acid ([3h]aa) mobilization, pleckstrin phosphorylation, and an increase in the cytosolic ca2+ concentration ([ca2+]in) due to both ca2+ entry and internal ca2+ mobiliza ... | 1998 | 9606958 |
| camp does not inhibit convulxin-induced tyrosyl-phosphorylation of human platelet proteins, including plcgamma2, but completely blocks the integrin alphaiib beta3-dependent dephosphorylation step: comparisons with rgds peptide, cytochalasin d, and phenylarsine oxide. | convulxin (cvx) isolated from crotalus durissus terrificus venom, induces platelet aggregation, phospholipase c (plc) activation, and tyrosyl-phosphorylation (ptp) of multiple proteins, including plcgamma2 by a mechanism independent of integrin alphaiib beta3. however, ptp induced by cvx is followed by a dephosphorylation step in a platelet aggregation-dependent manner. here we show that increasing intraplatelet content of camp with forskolin is associated with the inhibition of cvx-induced plat ... | 1998 | 9637734 |
| stepwise iodination. a general procedure for detoxification of proteins suitable for vaccine development and antiserum production. | by gradual incorporation of stable iodine into toxins and whole venoms it is possible to abolish completely the lesion and lethal properties of the native components. allergen extracts can be turned anallergic. physiological proteins with strong biological activity can also be rendered innocuous. tyrosine and histidine are the reactive groups that incorporate the hapten. within the same batch of protein, there is a defined ratio hapten/protein to achieve the desired modified properties of the de ... | 1998 | 9637746 |