Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| elisa for the detection of venom antigens in experimental and clinical envenoming by loxosceles intermedia spiders. | enzyme linked immunosorbent assays (elisa) were developed to detect antigens from loxosceles intermedia spider venom. hyperimmune horse anti-loxosceles intermedia iggs were prepared by immunoaffinity chromatography and used to set up a sandwich-type elisa. the specificity of the assay was demonstrated by its capacity to correctly discriminate the circulating antigens in mice that were experimentally inoculated with l. intermedia venom from those inoculated with l. gaucho, l. laeta, and phoneutri ... | 1998 | 9643469 |
| tension generation and increase in voltage-activated na+ current by crotamine. | we performed the present experiments to study the action of crotamine, a toxin isolated from the venom of the south american rattlesnake, crotalus durissus terrificus, on macroscopic na+ currents in frog skeletal muscle by using the loose patch clamp technique. crotamine at 50 microm increased the peak na+ current by 50% (p < 0.05). in addition, the voltage dependence of inactivation was shifted by +8 mv. other parameters of na+ currents (reversal potential, voltage-dependence of activation and ... | 1998 | 9652331 |
| irradiation of crotalus durissus terrificus crotoxin with 60co gamma-rays induces its uptake by macrophages through scavenger receptors. | to investigate the action of 2 kgy 60co gamma-rays on crotoxin and its favoured uptake through scavenger receptor (scvr) mouse peritoneal macrophages. | 1998 | 9652814 |
| tourniquet ineffectiveness to reduce the severity of envenoming after crotalus durissus snake bite in belo horizonte, minas gerais, brazil. | clinical and laboratory data from patients who applied a tourniquet (tourniquet group, n = 45) and who did not apply it (non-tourniquet group, n = 52) after being bitten by crotalus durissus were compared. the patients were treated with 100-200 ml of crotalus durissus antivenom. the gender, age, time elapsed between bite and hospital admission, dose of antivenom and the frequency of local paresthesia, myalgia and palpebral ptosis did not differ between the two groups. plasma creatine kinase enzy ... | 1998 | 9655642 |
| cloning of subunits of convulxin, a collagen-like platelet-aggregating protein from crotalus durissus terrificus venom. | convulxin (cvx) is a potent platelet-aggregating glycoprotein from the venom of the snake crotalus durissus terrificus. it consists of two subunits, alpha and beta, joined by disulphide bridges in a hexameric structure. a cdna library from venom gland was constructed in the vector pt3t7. the cloned cdnas encoding the two chains of cvx were sequenced. both are preceded by an identical 23-amino acid peptide signal sequence and encode sequences of 135 amino acids for the alpha chain and 125 amino a ... | 1998 | 9657980 |
| mitochondrial swelling and oxygen consumption during respiratory state 4 induced by phospholipase a2 isoforms isolated from the south american rattlesnake (crotalus durissus terrificus) venom. | the non-covalent interaction between two molecular entities namely, phospholipase a2 and crotapotin, results in the main toxin, crotoxin, present in the venom of the south american rattlesnake crotalus durissus terrificus. high performance liquid chromatography has enabled us the isolation of three phospholipase a2 isoforms (f1, f2 and f3), characterized through denaturing and non-denaturing polyacrylamide gel electrophoresis and also through the n-terminal amino acid sequence analysis. the effe ... | 1998 | 9663696 |
| physical and functional association of the src family kinases fyn and lyn with the collagen receptor glycoprotein vi-fc receptor gamma chain complex on human platelets. | we have previously shown that uncharacterized glycoprotein vi (gpvi), which is constitutively associated and coexpressed with fc receptor gamma chain (fcrgamma) in human platelets, is essential for collagen-stimulated tyrosine phosphorylation of fcrgamma, syk, and phospholipase cgamma2 (plcgamma2), leading to platelet activation. here we investigated involvement of the src family in the proximal signals through the gpvi-fcrgamma complex, using the snake venom convulxin from crotalus durissus ter ... | 1998 | 9670039 |
| [hemorrhagic and edema-forming activity and histologic changes in the mouse footpad induced by venoms from argentinian bothrops and crotalus genuses]. | hemorrhagic, oedema-forming activities and histopathological alterations in the mouse footpad induced by bothrops and crotalus snake venoms from argentina. hemorrhagic and oedema-forming activities of various bothrops and crotalus snake venoms from argentina were studied, together with histological alterations in the mouse footpad. the highest oedema-forming activity was found in the venom of b. jararaca, followed by b. jararacussu, b. neuwiedii diporus, b. alternatus, and crotalus durissus terr ... | 1998 | 9690783 |
| a monoclonal antibody directed against the non-toxic subunit of a dimeric phospholipase a2 neurotoxin, crotoxin, neutralizes its toxicity. | crotoxin is the main toxic component of the venom of the south-american rattlesnake crotalus durissus terrificus. it is a phospholipase a2 neurotoxin constituted by the association of two subunits: an acidic, non-toxic and non-enzymatic subunit (ca) and a basic, weakly toxic phospholipase a2 (cb). a murine monoclonal antibody directed to the non-toxic subunit ca, a-56.36, was shown to fully neutralize the toxicity of crotoxin. when the in vitro pharmacological properties of crotoxin were further ... | 1998 | 9705154 |
| effects of crotalus durissus cascavella venom in the isolated rat kidney. | crotalus durissus cascavella (c.d.c) is a snake usually found in scrubland of brazilian northeast and its bite constitutes an important public health problem. isolated kidneys from wistar rats, weighing 240 to 280 g, were perfused with krebs henseleit solution containing 6 g% of previously dialysed bovine serum albumin. the effects of c.d.c venom were studied on the perfusion pressure (pp), urinary flow (uf), glomerular filtration rate (gfr), percent of sodium tubular transport (%tna+) and perce ... | 1998 | 9723842 |
| the analgesic activity of crotamine, a neurotoxin from crotalus durissus terrificus (south american rattlesnake) venom: a biochemical and pharmacological study. | crotamine, a 4.88 kda neurotoxic protein, has been purified to apparent homogeneity from crotalus durissus venom by gel filtration on sephadex g-75. when injected (i.p. or s.c.) in adult male swiss mice (20-25 g), it induced a time-dose dependent analgesic effect which was inhibited by naloxone, thus suggesting an opioid action mechanism. when compared with morphine (4 mg/kg), crotamine, even in extremely low doses (133.4 microg/kg, i.p., about 0.4% of a ld50 is approximately 30-fold more potent ... | 1998 | 9839677 |
| a study on the venom yield of venomous snake species from argentina. | a study on the venom yield of snakes from argentina over a three year period was carried out on adult specimens of bothrops alternatus (n = 74); bothrops neuwiedii (n = 127); bothrops ammodytoides (n = 30); bothrops moojeni (n = 14); bothrops jararaca (n = 14); b. jararacussu (n = 6); crotalus durissus terrificus (n = 120) and micrurus spp. (n = 6) as well as with 12 specimens of newborn c. d. terrificus kept in captivity. while for each species there was a positive correlation between venom yie ... | 1998 | 9839679 |
| south american rattlesnake bite (crotalus durissus sp) without envenoming: insights on diagnosis and treatment. | a south american rattlesnake bite without clinical manifestations of envenoming (termed 'dry-bite') has not been recognized to occur by the brazilian ministry of health, which recommends the administration of antivenom to all bitten patients. during 36 months of an observational study on south american rattlesnake bites in minas gerais, brazil, 12% of 41 patients with fang marks at the bite-site did not present clinical or laboratory features of envenoming and had no plasma venom detected before ... | 1998 | 9839686 |
| differential biodistribution of native and 2 kgy 60co irradiated crotoxin in tissues of cba/j mice. | crotalus durissus envenomation is treated using antivenins produced in horses. during production, animals have problems, sometimes followed by death, due to the high toxicity of the main toxin, crotoxin. several methods tested to detoxify this toxin often resulted in decreased immunogenicity. gamma irradiation has proved to be a successful method for crotoxin detoxification without loss of immunogenicity. we have studied the biodistribution of 2 kgy 60co irradiated crotoxin (ictx) in mouse tissu ... | 1998 | 9851508 |
| thermal stability studies of hyperimmune horse antivenoms. | ampoules of horse antivenoms raised against bothrops spp and crotalus durissus (final product) produced by fundação ezequiel dias (funed) were fractionated on the molecular filtration chromatography (superose 12) and the expected mw species of f(ab')2 fragments were observed. it has been known that high temperatures promote aggregation and formation of protein precipitates. phenol is used in preparations of antivenoms as preservative; however, as thus is a hydrophobic substance, it can also indu ... | 1999 | 9920478 |
| comparison of the biological activities in venoms from three subspecies of the south american rattlesnake (crotalus durissus terrificus, c. durissus cascavella and c. durissus collilineatus) | the subspecies of the south american rattlesnake, crotalus durissus are classified according to their external morphological features and geographical distribution. we have determined some biological activities of c. durissus cascavella, c. durissus collilineatus and c. durissus terrificus venoms. c. durissus terrificus had a significantly higher clotting activity on bovine plasma and fibrinogen, human fibrinogen and rabbit plasma. c. durissus cascavella presented a statistically higher phosphol ... | 1999 | 10190029 |
| evidence for a regulatory role of cholesterol superlattices in the hydrolytic activity of secretory phospholipase a2 in lipid membranes. | we have conducted a detailed study of the effect of membrane cholesterol content on the initial hydrolytic activity of crotalus durissus terrificus venom phospholipase a2 (spla2) in large unilamellar vesicles of cholesterol/dimyristoyl-l-alpha-phosphatidylcholine (dmpc) and cholesterol/1-palmitoyl-2-oleoyl-l-alpha-phosphatidylcholine (popc) at 37 degrees c. the activity was monitored by using the acrylodan-labeled intestinal fatty acid binding protein and hplc. in contrast to conventional approa ... | 1999 | 10194297 |
| toxicity and immunogenicity of crotalus durissus terrificus venom treated with different doses of gamma rays. | crotalus durissus terrificus venom (cdt venom) was irradiated with four different doses of gamma rays (2, 3, 5 and 10 kgy) from a 60co source and their structural, toxic and immunogenic properties were analysed. venom irradiated with 2 and 3 kgy were, respectively, 2.7 and 13.5 times less toxic than the native one, whereas the 5 or 10 kgy irradiated venom were at least 100 times less toxic than nonirradiated venom. irradiated venom with all doses were immunogenic and the antibodies elicited by t ... | 1999 | 10400297 |
| neutralizing capacity of antisera raised in horses and rabbits against crotalus durissus terrificus (south american rattlesnake) venom and its main toxin, crotoxin. | crotalus durissus terrificus (south american rattlesnake) venom possesses myotoxic and neurotoxic activities, both of which are also expressed by crotoxin, the principal toxin of this venom. we have investigated the ability of commercial equine antivenom and antivenoms raised in rabbits against c. d. terrificus venom and crotoxin to neutralize the physiological and morphological changes induced by this venom and crotoxin in electrically-stimulated phrenic nerve-diaphragm (pnd) and extensor digit ... | 1999 | 10414861 |
| identification of bothrojaracin-like proteins in snake venoms from bothrops species and lachesis muta. | bothrojaracin, a 27 kda protein isolated from bothrops jararaca venom, forms a non-covalent complex with thrombin, thus blocking its activity. we have previously identified a bothrojaracin-like protein in b. alternatus venom [castro, h.c., dutra, d.l.s., oliveira-carvalho, a.l., zingali, r.b., 1998. bothroalternin, an inhibitor of thrombin from the venom of bothrops alternatus. toxicon 36, 1903-1912]. in this report, we have examined snake venoms from six different bothrops species (b. atrox, b. ... | 1999 | 10414865 |
| [cross neutralization of bothrops jararacussu venom by heterologous antivenoms]. | we have studied the immunochemical cross-reactivity and cross-neutralization of the lethal potency, hemorrhagic, necrotizing, procoagulant and (indirect) hemolytic activities of bothrops jararacussu venom by the standard antivenoms produced in argentina. these antivenoms are horse immunoglobulin f (ab')2 fragments from animals immunized with 1) crotalus durissus terrificus venom (monovalent anticrotalic antivenom); 2) bothrops alternatus and b. neuwiedii venoms (bivalent botropic antivenom); 3) ... | 1999 | 10451561 |
| nucleotide sequence of crotamine isoform precursors from a single south american rattlesnake (crotalus durissus terrificus). | a cdna phage library was constructed from venom glands of a single adult specimen of crotamine-plus crotalus durissus terrificus (south american rattlesnake) captured in a known region. fifteen crotamine positive clones were isolated using a pcr-based screening protocol and sequenced. these complete cdnas clones were grouped for maximal alignment into six distinct nucleotide sequences. the crotamine cdnas, with 340-360 bases, encompass open reading frame of 198 nucleotides with 5' and 3' untrans ... | 1999 | 10484745 |
| primary culture of venom gland cells from the south american rattlesnake (crotalus durissus terrificus). | primary cultures of venom gland cells from the south american rattlesnake (crotalus durissus terrificus) were attempted. at first, six different cell types were obtained including potentially secreting epithelial-like cells. nonepithelial cell cultures were later invaded by fibroblast-like cells. cultures of epithelial-like gland cells were successfully maintained, after testing different culture conditions by varying the media, incubation temperature, use of dissociating agents and adhesion sub ... | 1999 | 10519646 |
| studies on the specificity of cnf, a phospholipase a2 inhibitor isolated from the blood plasma of the south american rattlesnake (crotalus durissus terrificus). i. interaction with pla2 from lachesis muta muta snake venom. | a phospholipase a2 inhibitor has been previously purified and cloned from the blood plasma of the south american rattlesnake, crotalus durissus terrificus. this inhibitor, named cnf for crotalus neutralizing factor, interacts with crotoxin, the main neurotoxin from c. d. terrificus venom, abolishing its phospholipase a2 activity. crotoxin is a heterodimer of an acidic subunit (ca) and a basic phospholipase a2 (cb). cnf acts by forming a stable non-toxic complex with cb, replacing ca in the toxic ... | 1999 | 10519652 |
| megaselia scalaris (diptera: phoridae) causing myiasis in crotalus durissus terrificus (serpentes: viperidae) in brazil. | we describe a case of myiasis in crotalus durissus terrificus (laurenti) caused by megaselia scalaris (loew). the snake was found in anhembi, sao paulo, brazil, with a lesion measuring 25 mm in diameter where the larvae of m. scalaris had penetrated the ribs. the opportunistic behavior of the larvae of m. scalaris is discussed. | 1999 | 10534959 |
| gabaergic-benzodiazepine system is involved in the crotoxin-induced anxiogenic effect. | the behavioral effects of crotoxin (ctx), the major component of crotalus durissus terrificus venom, were studied in rats submitted to the open field, holeboard, and social interaction tests. ctx (100, 250, and 500 microg/kg, i.p.) was administered 2 h before the tests. in the open field, ctx reduced ambulation (250 microg/kg) and rearing (250 and 500 microg/kg) and increased grooming (100 and 250 microg/kg) and freezing (250 microg/kg). in the holeboard and social interaction, all the ctx doses ... | 2000 | 10638629 |
| effect of crotapotin and heparin on the rat paw oedema induced by different secretory phospholipases a2. | the effects of crotapotin (a non-toxic and non-enzymatic acid polypeptide naturally complexed with phospholipase a2) and heparin on rat paw edema induced by different secretory phospholipases a2 (spla2) have been investigated. the ability of crotapotin to affect the enzymatic activity of the spla2(s) have also been evaluated. secretory pla2(s) obtained from both snake (naja naja, naja mocambique mocambique, crotalus adamanteus and crotalus durissus terrificus) and bee (apis mellifera) venoms as ... | 2000 | 10665801 |
| quantification of crotamine, a small basic myotoxin, in south american rattlesnake (crotalus durissus terrificus) venom by enzyme-linked immunosorbent assay with parallel-lines analysis. | intraspecific variation in crotalus durissus terrificus venom composition was studied in relation to crotamine activity. crotamine induces paralysis in extension of hind legs of mice and myonecrosis in skeletal muscle cells. to determine whether the venom of crotamine-negative rattlesnake contains a quantity of myotoxin incapable of inducing paralysis, we have developed a very sensitivity immunological assay method, an enzyme-linked immunoabsorbent assay (elisa), capable of detecting 0.6 ng of p ... | 2000 | 10669031 |
| horse igg isotypes and cross-neutralization of two snake antivenoms produced in brazil and costa rica. | horse igg isotypes and cross-neutralization of two snake antivenoms produced in brazil and costa rica. toxicon 000-000. this work compared the specificity, elisa titers and igg subclass content of the polyvalent antivenom (anti-bothrops asper, crotalus durissus durissus and lachesis muta stenophrys) of instituto clodomiro picado (costa rica) and the bothropic antivenom (anti-bothrops jararaca, b. jararacussu, b. moojeni, b. neuwiedi and b. alternatus) of instituto butantan (brazil). the role of ... | 2000 | 10673156 |
| biochemical characterization of two crotamine isoforms isolated by a single step rp-hplc from crotalus durissus terrificus (south american rattlesnake) venom and their action on insulin secretion by pancreatic islets. | crotamine, a neurotoxin present in the venom of the south american rattlesnake crotalus durrisus terrificus exists as several polymorphic variants, as demonstrated by recombinant dna technology (smith and schmidt, toxicon 28 (1990) 575-585). we have isolated native crotamine by chromatography on sephadex g75, and have purified two crotamine isoforms (f2 and f3) by a single step of rp-hplc. native crotamine and rp-hplc fractions f2 and f3 produced skeletal muscle spasms and spastic paralysis in m ... | 2000 | 10699490 |
| influence of temperature upon effects of crotoxin and gamma-irradiated crotoxin at rat neuromuscular transmission. | the influence of temperature upon the effects of crotoxin (ctx), from crotalus durissus terrificus venom, and gamma-irradiated (60co, 2000 gy) crotoxin (ictx) was studied in rat neuromuscular transmission 'in vitro'. indirect twitches were evoked in the phrenic-diaphragm preparation by supramaximal strength pulses with a duration of 0.5 ms and frequency of 0.5 hz. the phospholipase a(2) (pla(2)) enzymatic activity of ctx and ictx was assayed against phosphadityl choline in triton x-100. at 27 de ... | 2000 | 10713471 |
| delta-opioid receptors and nitric oxide mediate the analgesic effect of crotalus durissus terrificus snake venom. | the antinociceptive effect of crotalus durissus terrificus venom was investigated in a model of inflammatory hyperalgesia induced by carrageenin. the rat paw pressure test was applied before and 3 h after the intraplantar (i.pl.) injection of carrageenin. the venom administered per os before and 1 or 2 h after carrageenin blocked hyperalgesia. when carrageenin was injected in both hind paws and naloxone into one hind paw, antinociception was abolished only in the paw injected with naloxone. d-ph ... | 2000 | 10720635 |
| neutralizing human anti crotoxin scfv isolated from a nonimmunized phage library. | combinatorial phage display technology offers a new possibility for making human antibodies which could be used in immune therapy. we explored the use of this technology to make human scfvs specific for crotoxin, the main toxic component of the venom of the south-american rattlesnake crotalus durissus terrificus. crotoxin, a phospholipase a2 neurotoxin constituted by the association of two subunits, exerts its lethal action by blocking neuromuscular transmission. this is the first report of huma ... | 2000 | 10736105 |
| effect of heating on the toxic, immunogenic and immunosuppressive activities of crotalus durissus terrificus venom. | the venom of south american rattlesnake crotalus durissus terrificus is very toxic but poorly immunogenic and it has an immunosuppressive ability. the heating of venom at 56, 70 or 100 degrees c for 30 min caused a diminution in the lethal, phospholipase a(2) and myotoxic activities. sds-page analysis of the heated venom showed that the proteins of higher molecular weights were the most affected by heating whereas proteins with lower molecular weights (20,000-14, 000) were the most resistant to ... | 2000 | 10758279 |
| combining phage display and molecular modeling to map the epitope of a neutralizing antitoxin antibody. | crotoxin is a potent presynaptic neurotoxin from the venom of the rattlesnake crotalus durissus terrificus. it is composed of the noncovalent and synergistic association of a weakly toxic phospholipase a2, cb, and a nontoxic three-chain subunit, ca, which increases the lethal potency of cb. the a-56.36 mab is able to dissociate the crotoxin complex by binding to the ca subunit, thereby neutralizing its toxicity. because a-56.36 and cb show sequence homology and both compete for binding to ca, we ... | 2000 | 10759860 |
| role of the recombinant non-integrin platelet collagen receptor p65 on platelet activation induced by convulxin. | convulxin (cvx) isolated from crotalus durissus terrificus venom selectively binds with a high affinity to platelets and induces platelet aggregation by a mechanism that resembles that induced by collagen. taking advantage that p65 has been recently cloned and expressed as a recombinant soluble protein (rec-p65), we examined the role of this non-integrin collagen receptor in platelet activation induced by cvx. rec-p65 blocked platelet adhesion to collagen-coated surfaces and inhibited platelet a ... | 2000 | 10772928 |
| convulxin binding to platelet receptor gpvi: competition with collagen related peptides. | convulxin (cvx), a potent platelet aggregating protein from the venom of the snake crotalus durissus terrificus, is known to bind to the platelet collagen receptor, glycoprotein vi (gpvi). cvx binding to human platelets was investigated by flow cytometry, using fluorescein labeled convulxin (fitc-cvx). scatchard analysis indicated high and low affinity binding sites with kd values of 0.6 and 4 nm and bmax values of 1200 and 2000 binding sites per platelet. fitc-cvx binding was inhibited by colla ... | 2000 | 10873594 |
| interaction of the neurotoxic and nontoxic secretory phospholipases a2 with the crotoxin inhibitor from crotalus serum. | crotalus durissus terrificus snakes possess a protein in their blood, named crotoxin inhibitor from crotalus serum (cics), which protects them against crotoxin, the main toxin of their venom. cics neutralizes the lethal potency of crotoxin and inhibits its phospholipase a2 (pla2) activity. the aim of the present study is to investigate the specificity of cics towards snake venom neurotoxic pla2s (beta-neurotoxins) and nontoxic mammalian pla2s. this investigation shows that cics does not affect t ... | 2000 | 10903514 |
| inhibition of the lethal and myotoxic activities of crotalus durissus terrificus venom by tabernaemontana catharinensis: identification of one of the active components. | in brazilian folk medicine, victims of bites by poisonous animals are usually treated with plant extracts derived from the diverse national flora. the chemical and pharmacological properties of most extracts were yet not investigated. in the rural community of assis-sp, the root bark of tabernaemontana catharinensis ("leiteiro", "cow milk") is applied to the site of the snake bite and believed to neutralize the effect of the venom. we report here the ability of the lyophilized aqueous extract (a ... | 2000 | 10909261 |
| south american rattlesnake bite and soft-tissue infection: report of a case. | the case of a man bitten by a south american rattlesnake (crotalus durissus) and who developed an abscess at the site of the bite is reported. abcesses are a rare complication of this type of envenoming, possibly due to the lack of a strong cytotoxic action of crotalus durissus venom. | 2000 | 10936955 |
| crotoxin, the major toxin from the rattlesnake crotalus durissus terrificus, inhibits 3h-choline uptake in guinea pig ileum. | we examined the effect of crotoxin, the neurotoxic complex from the venom of the south american rattlesnake crotalus durissus terrificus, on the uptake of 3h-choline in minces of smooth muscle myenteric plexus from guinea pig ileum. in the concentration range used (0. 03-1 microm) and up to 10 min of treatment, crotoxin decreased 3h-choline uptake by 50-75% compared to control. this inhibition was time dependent and did not seem to be associated with the disruption of the neuronal membrane, beca ... | 2000 | 10973144 |
| red blood cells from the south american rattlesnake (crotalus durissus terrificus) regulate volume incompletely following osmotic shrinkage and swelling in vitro. | the ability of rattlesnake (crotalus durissus terrificus) red blood cells to volume regulate in vitro has been investigated. blood was drawn through a catheter inserted in the dorsal aorta and equilibrated to gas mixtures of different composition. cells shrunken osmotically by increasing the extracellular osmolarity from approximately 291 mosm l(-1) (n=3) to approximately 632 mosm l(-1) (calculated) only partially regulated their volume back towards the original volume either at ph 7.51+/-0.05 ( ... | 2000 | 10996817 |
| sexual dimorphism in the hypothalamo-pituitary-adrenal (hpa) axis and tnfalpha responses to phospholipase a2-related neurotoxin (from crotalus durissus terrifcus) challenge. | neuroendocrine-immune interactions are vital for the individual's survival in certain physiopathological conditions such as sepsis and tissular injury. it is known that several snake venoms (sv) are potent neurotoxic compounds and that their main component is a specific phospholipase type 2 (pla2). it has been recently described that the venom from crotalus durissus terrificus (sv) possesses a cytotoxic effect in different in vitro and in vivo animal models. in the present study we investigated ... | 2016 | 11005268 |
| one-month safety study of intraperitoneal vrctc-310-onco (crotoxin + cardiotoxin) in rats. | to evaluate the toxicity of vrctc-310-onco (crotalus durissus terrificus crotoxin + cardiotoxin from naja naja atra), 10 sprague-dawley rats were implanted with intraperitoneal slow-release devices and subjected to treatment with 0.5 microgram/g body weight/d for 14 days. biochemical evidence at days 7 and 14 showed blood, muscular, renal and metabolic disturbance, mostly reversed by day 28. no significant changes were found in necropsy. the limited toxicity of i.p. vrctc-310-onco in rats deserv ... | 2000 | 11050707 |
| intraspecific variation in the venoms of the south american rattlesnake (crotalus durissus terrificus). | the venom of eight individual crotalus durissus terrificus snakes from the state of minas gerais, brazil, in addition to pooled venom from butantan institute, were compared. snakes were captured in distinct locations, some of them 600 km apart: conselheiro lafaiete, entre rios de minas, itauna, itapecerica, lavras, patos de minas, paracatu, and santo antonio do amparo. the crude venoms were tested for proteolytic, phospholipase a2, platelet aggregating, and hemagglutinating activities. the venom ... | 2000 | 11081410 |
| gyroxin fails to modify in vitro release of labelled dopamine and acetylcholine from rat and mouse striatal tissue. | gyroxin fails to modify in vitro release of labelled dopamine and acetylcholine from rat and mouse striatal tissue. gyroxin is a thrombin-like peptide with amidasic, esterasic and fibrinogenolitic activities, found in the venom of snakes like lachesis muta muta and crotalus durissus terrificus. intravenous injections of small doses of gyroxin induce a typical barrel rotation behaviour that has been thought to be a neurotoxic effect. the aim of this study was to determine whether gyroxin-induced ... | 2001 | 11137545 |
| enzymatic characterization of a novel phospholipase a2 from crotalus durissus cascavella rattlesnake (maracambóia) venom. | the pla2 and crotapotin subunits of crotoxin from crotalus durissus cascavella venom were purified by a combination of hplc molecular exclusion (protein pack 300sw column) and reverse-phase hplc (rp-hplc). tricine sds-page showed that the pla2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kda, respectively. the amino acid composition of the pla2 showed the presence of 14 half-cysteines and a high content of basic residues (lys, arg, his), whereas the crotap ... | 2000 | 11233174 |
| effect of membrane composition and of co-encapsulation of immunostimulants in a liposome-entrapped crotoxin. | crotoxin isolated from the venom of crotalus durissus terrificus (south american rattlesnake) was incorporated into liposomes by the dehydration-rehydration vesicle method using different membrane compositions and the co-encapsulation of immunostimulants. crotoxin was also encapsulated into liposomes formed from a non-phospholipid amphiphile, a mixture of polyoxyethylene 2-cetyl ether, dicetyl phosphate and cholesterol. the preparations were characterized in relation to stability, toxicity and t ... | 2001 | 11277856 |
| systemic skeletal muscle necrosis induced by crotoxin. | systemic skeletal muscle necrosis induced by crotoxin, the major component of the venom of crotalus durissus terrificus, was investigated. mice received an intramuscular injection of crotoxin (0.35mg/kg body weight) into the right tibialis anterior (ta) muscles, which were evaluated 3h, 24h and 3 days later. control mice were injected with saline. right and left tas, gastrocnemius, soleus and right masseter and longissimus dorsi were removed and frozen. histological sections were stained with to ... | 2001 | 11306124 |
| enzymatic characterization of a novel phospholipase a2 from crotalus durissus cascavella rattlesnake (maracambóia) venom. | the pla2 and crotapotin subunits of crotoxin from crotalus durissus cascavella venom were purified by a combination of high-performance liquid chromatography (hplc) molecular exclusion (protein pack 300sw column) and reverse-phase hplc (rp-hplc). tricine sds-page showed that the pla2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kda, respectively. the amino acid composition of the pla2 showed the presence of 14 half-cysteines and a high content of basic res ... | 2000 | 11307952 |
| tolerance to the antinociceptive effect of crotalus durissus terrificus snake venom in mice is mediated by pharmacodynamic mechanisms. | crotalus durissus terrificus venom exerts central and peripheral antinociceptive effect mediated by opioid receptors. the present work investigated the tolerance to the antinociceptive effect of the venom and characterised the mechanisms involved in this phenomenon. the hot plate test, applied in mice, was used for pain threshold determination. the venom (200 microg/kg) was administered by oral route, daily, for 14 days, and the nociceptive test was applied before and on days 1, 7 and 14 of the ... | 2001 | 11384730 |
| karl heinrich slotta (1895-1987) biochemist: snakes, pregnancy and coffee. | in 1923 karl h. slotta obtained his phd in chemistry from the university of breslau, germany, where he continued to work. at the instigation of the gynaecologist ludwig fraenkel, slotta made the first isolation of progesterone in 1933. in 1934 he proposed the correct structural formula. slotta was appointed professor of chemistry in 1935, but with the oppression of the nazi regime mounting, he soon left germany with his family to take a post at the instituto butantan, brazil. initially he worked ... | 2001 | 11447968 |
| effects of chemical modifications of crotoxin b, the phospholipase a(2) subunit of crotoxin from crotalus durissus terrificus snake venom, on its enzymatic and pharmacological activities. | crotoxin b, the basic asp49-pla(2) subunit from crotoxin, the main component of crotalus durissus terrificus venom, displays myotoxic, edema-inducing, bactericidal (upon escherichia coli), liposomal-disrupting and anticoagulant activities. chemical modifications of his (with 4-bromophenacyl bromide, bpb), tyr (with 2-nitrobenzenesulphonyl fluoride, nbsf), trp (with o-nitrophenylsulphenyl chloride, npsc) and lys (with acetic anhydride) residues of this protein, in addition to cleavage with cyanog ... | 2001 | 11461830 |
| determination of the neutralizing potency of horse antibothropic and anticrotalic antivenoms in blood samples collected on filter paper. | the correlation coefficients between in vivo neutralization of lethal toxicity (ed(50)) and levels of antibodies measured by enzyme-linked immunosorbent assay (elisa) in blood samples collected on filter paper were investigated to test the potency of horse antibothropic and anticrotalic antivenoms. sixteen horses were hyperimmunized with bothrops venom (50% from b. jararaca and 12.5% each from b. alternatus, b. jararacussu, b. neuwiedii and b. moojeni) and 12 horses with crotalus durissus terrif ... | 2001 | 11478970 |
| snake inhibitors of phospholipase a(2) enzymes. | phospholipase a(2) (pla(2)) enzymes consist of a large family of proteins which share the same enzymatic function and display considerable sequence homology. these enzymes have been identified and characterised in mammalian tissue and snake venoms. numerous physiological functions have been attributed to mammalian pla(2)s and they are nontoxic. in comparison, venom pla(2)s are toxic and induce a variety of pharmacological effects that are probably mediated via membrane receptors. snake pla(2) in ... | 2001 | 11514233 |
| role of crotoxin, a phospholipase a2 isolated from crotalus durissus terrificus snake venom, on inflammatory and immune reactions. | crotoxin (ctx) is a potent neurotoxin from crotalus durissus terrificus snake venom (cdtv) composed of two subunits: one without catalytic activity (crotapotin), and a basic phospolipase a2. recent data have demonstrated that cdtv or ctx inhibit some immune and inflammatory reactions. | 2001 | 11545249 |
| isolation and enzymatic characterization of a basic phospholipase a2 from bothrops jararacussu snake venom. | a novel basic phospholipase a2 (pla2) isoform was isolated from bothrops jararacussu snake venom and partially characterized. the venom was fractionated by hplc ion-exchange chromatography in ammonium bicarbonate buffer, followed by reverse-phase hplc to yield the protein bj iv. tricine sds-page in the presence or absence of dithiothreitol showed that bj iv had a molecular mass of 15 and 30 kda, respectively. this enzyme was able to form multimeric complexes (30, 45, and 60 kda). amino acid anal ... | 2001 | 11565904 |
| coagulopathy following lethal and non-lethal envenoming of humans by the south american rattlesnake (crotalus durissus) in brazil. | the south american tropical rattlesnake (crotalus durissus subspp) is responsible for approximately 10% of bites from venomous snakes in brazil. we studied 24 victims of bites by this species over 3 years, in south-eastern brazil, particularly investigating haemostatic alterations. thirteen patients were defined as moderately envenomed and 11 as severe. there were two deaths, which were not attributed to venom-induced haemostatic disturbances. however, envenoming by c. durissus is frequently ass ... | 2001 | 11588214 |
| crotalus durissus terrificus snake venom regulates macrophage metabolism and function. | in the present study, we examined the effect of crotalus durissus terrificus venom on rat macrophage metabolism and function. two hours after subcutaneous injection of the venom, peritoneal resident (unstimulated), elicited (thioglycollate-stimulated), and activated mycobacterium bovis strain bacille calmette guérin (bcg) macrophages were collected, and their functional and metabolic parameters were analyzed. the venom inhibited spreading and phagocytosis of macrophages. on the other hand, this ... | 2001 | 11590191 |
| actions of crotalus durissus terrificus venom and crotoxin on the isolated rat kidney. | many studies have reported the occurrence of lethal acute renal failure after snakebites. the aim of the present investigation was to determine alterations in renal function produced by crotalus durissus terrificus venom and crotoxin as well as the histological alterations induced by these venoms. isolated kidneys from wistar rats weighing 240 to 280 g were perfused with krebs-henseleit solution containing 6 g% of previously dialyzed bovine serum albumin. the effects of crotalus durissus terrifi ... | 2001 | 11593312 |
| analysis of fatty acids released by crotoxin in rat brain synaptosomes. | crotoxin, the main toxin of crotalus durissus terrificus venom, exerts its lethal effect by blocking neurotransmission at the neuromuscular junction level through a triphasic mechanism. this effect seems to depend on its phospholipasic activity, suggesting that the mechanism of neurotransmission blockage may be related to fatty acids release in specific sites of the nervous terminal. in this work, we purified the fatty acids released by crotoxin's activity and this outline was compared with othe ... | 2002 | 11602277 |
| effects of (60)co gamma radiation on crotamine. | ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. this has been employed to attenuate animal toxins. crotamine is a strongly basic polypeptide (pi 10.3) from crotalus durissus terrificus venom composed of 42 amino acid residues. it induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. the objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated c ... | 2001 | 11717705 |
| isolation and characterization of a convulxin-like protein from crotalus durissus collilineatus venom. | a convulxin (cvx)-like protein was isolated from crotalus durissus collilineatus venom by a combination of molecular exclusion and reversed-phase hplc chromatographies. the molecular mass of the cvx-like protein in the absence and presence of dtt was 78 kda and 12-13 kda, respectively. the cvx-like protein consisted of two nonidentical polypeptide chains (alpha and beta). the n-terminal amino-acid sequences of the alpha and beta subunits were glhcpsdwyaydghcykifneemnwed and gfccpshwssysrycykffsq ... | 2001 | 11838547 |
| antifungal activity of crotalus durissus cumanensis venom. | the susceptibility to crotalus venom of 14 yeast and 10 mould fungal isolates was assessed. this venom was tested in a standardized well diffusion test, using 400 microg/20 microl well. the percentage of susceptibility to yeast isolates was 78.6% (> 8 mm); that for filamentous isolates was 50% (> 8 mm). | 2002 | 11856432 |
| a proposed 3d structure for crotamine based on homology building, molecular simulations and circular dichroism. | crotamine, isolated from the venom of the south american rattlesnake crotalus durissus terrificus is a strongly basic 42-amino acid polypeptide belonging to the small basic myotoxin family. as no tridimensional structure is available for this myotoxin subfamily, despite its important pharmacological interest, we propose in this paper a theoretical 3d model for crotamine. starting from a homology modelling procedure, followed by intensive molecular dynamics (md) simulations in water and complemen ... | 2002 | 11887801 |
| comparison of the biodistribution of free or liposome-entrapped crotalus durissus terrificus (south american rattlesnake) venom in mice. | the local absorption rate, clearance and tissue distribution of crotalus durissus terrificus venom, (cdt) were examined using a two-antibody sandwich elisa assay. we compared the biodistribution of both free or encapsulated cdt in mice. following subcutaneous injection of 10 microg/mouse of free cdt (0.8 ld50), venom was detected in serum after 15 min, showed its highest level at 30 min (45+/-5 ng/ml) and was cleared from the circulation after 6 h. after 2 h of inoculation, venom was detected in ... | 2002 | 11912054 |
| a taxonomic bibliography of the south american snakes of the crotalus durissus complex (serpentes, viperidae). | a survey is made of the taxonomic literature on south american rattlesnakes (genus crotalus, family viperidae). two main areas are emphasized: the attribution of the names proposed in the eighteenth century by linnaeus and laurenti, and the current scheme of division in subspecies. the attribution of names is examined based on the original descriptions and on relevant previous and contemporary literature. the presently adopted scheme, proposed by klauber (1941, 1972) is found not entirely satisf ... | 2002 | 11960177 |
| isolation and preliminary enzymatic characterization of a novel pla2 from crotalus durissus collilineatus venom. | a crotoxin homolog was purified from the crotalus durissus collilineatus venom using molecular exclusion and reverse-phase hplc. this crotoxin contained one pla2 (cdcolli iii f6) and four crotapotin isoforms, whereas crotoxin from crotalus durissus terrificus venom had three pla2 iso forms and two crotapotin isoforms. sds-page showed that the c. d. collilineatus pla2 and crotapotin had relative molecular mass of 15 and 9 kda, respectively. neither the pla2 (cdcolli iii f6) nor the crotapotins (c ... | 2002 | 12018613 |
| structural and functional characterization of basic pla2 isolated from crotalus durissus terrificus venom. | the venom of crotalus durissus terrificus was fractionated by reverse-phase hplc to obtain crotapotins (f5 and f7) and pla2 (f15, f16, and f17) of high purity. the phospholipases a2 (pla2s) and crotapotins showed antimicrobial activity against xanthomonas axonopodis pv. passiflorae, although the unseparated crotoxin did not. the f17 of the pla2 also revealed significant anticoagulant activity, althrough for this to occur the presence of glu 53 and trp 61 is important. the f17 of the pla2 showed ... | 2002 | 12018617 |
| snakebites by crotalus durissus ssp in children in campinas, são paulo, brazil. | from january, 1984 to march, 1999, 31 children under 15 y old (ages 1-14 y, median 8 y) were admitted after being bitten by rattlesnakes (crotalus durissus ssp). one patient was classified as "dry-bite", 3 as mild envenoming, 9 as moderate envenoming and 18 as severe envenoming. most patients had neuromuscular manifestations, such as palpebral ptosis (27/31), myalgia (23/31) and weakness (20/31). laboratory tests suggesting rhabdomyolysis included an increase in total blood creatine kinase (ck, ... | 2002 | 12163905 |
| determination of crotalus durissus cascavella venom components that induce renal toxicity in isolated rat kidneys. | envenomation by crotalus durissus terrificus leads to coagulation disorders, myotoxicity, neurotoxicity and acute renal failure (arf). the most serious systemic change and primary cause of death is arf. in this work, we used rp-hplc to isolate crotoxin, convulxin and gyroxin from venom of the related subspecies crotalus durissus cascavella and investigated the effects of these toxins on renal function in the isolated rat kidneys perfused with krebs-henseleit solution containing 6% of bovine seru ... | 2002 | 12165320 |
| [snake envenomation in french guiana]. | french guiana is a french overseas department in south america. ninety-five percent of the territory is a tropical rainforest. its rich fauna includes seven families of snakes but only 3 are potentially venomous. less than 12% of species and, depending on biotope, 10 to 30% of specimens collected are dangerous for humans. the annual incidence of snakebite is less than 50 bites per 100,000 inhabitants overall but increases to 600 per 100,000 for persons active in the rainforest where the risk is ... | 2002 | 12192717 |
| geographic and ontogenic variability in the venom of the neotropical rattlesnake crotalus durissus: pathophysiological and therapeutic implications. | a comparative study was performed on the venoms of adult specimens of the neotropical rattlesnake, crotalus durissus, from guatemala, costa rica, venezuela and brazil, together with the venom of newborn specimens of c. d. durissus from costa rica. venoms from brazil (c. d. terrificus) and from newborn specimens of c. d. durissus presented an electrophoretic pattern characterized by the predominance of bands with molecular mass of 36 and 15 kda, whereas those of adult specimens of c. d. durissus ... | 2002 | 12298262 |
| occurrence of cryptosporidium (apicomplexa, cryptosporidiidae) in crotalus durissus terrificus (serpentes, viperidae) in brazil. | the objective of the present study was to investigate the prevalence of cryptosporidium (apicomplexa, cryptosporidiidae) in the snake crotalus durissus terrificus (serpentes, viperidae). fifty animals were evaluated for the presence of oocysts of cryptosporidium sp. at the time of arrival and 30 and 60 days later. intestinal washings with saline solution (1% body weight), fecal samples, and organ scrapings were collected during the study. oocysts were concentrated by an ether-phosphate-buffered ... | 2002 | 12386695 |
| fluorometric assay using naphthylamide substrates for assessing novel venom peptidase activities. | in the present study we examined the feasibility of using the fluorometry of naphthylamine derivatives for revealing peptidase activities in venoms of the snakes bothrops jararaca, bothrops alternatus, bothrops atrox, bothrops moojeni, bothrops insularis, crotalus durissus terrificus and bitis arietans, of the scorpions tityus serrulatus and tityus bahiensis, and of the spiders phoneutria nigriventer and loxosceles intermedia. neutral aminopeptidase (apn) and prolyl-dipeptidyl aminopeptidase iv ... | 2002 | 12419513 |
| cdna sequence and molecular modeling of a nerve growth factor from bothrops jararacussu venomous gland. | the complete nucleotide sequence of a nerve growth factor precursor from bothrops jararacussu snake (bj-ngf) was determined by dna sequencing of a clone from cdna library prepared from the poly(a) + rna of the venom gland of b. jararacussu. cdna encoding bj-ngf precursor contained 723 bp in length, which encoded a prepro-ngf molecule with 241 amino acid residues. the mature bj-ngf molecule was composed of 118 amino acid residues with theoretical pi and molecular weight of 8.31 and 13,537, respec ... | 2002 | 12453640 |
| structural and functional analysis of bmjmip, a phospholipase a2 myotoxin inhibitor protein from bothrops moojeni snake plasma. | a protein, which neutralizes the enzymatic, toxic, and pharmacological activities of various basic and acidic phospholipases a(2) from the venoms of bothrops moojeni, bothrops pirajai, and bothrops jararacussu, was isolated from b. moojeni snake plasma by affinity chromatography using immobilized myotoxins on sepharose gel. biochemical characterization of this myotoxin inhibitor protein (bmjmip) showed it to be an oligomeric glycoprotein with a m(r) of 23,000-25,000 for the monomeric subunit. bm ... | 2003 | 12604331 |
| crotoxin acceptor protein isolated from torpedo electric organ: binding properties to crotoxin by surface plasmon resonance. | crotoxin, a potent neurotoxin from the south american rattlesnake crotalus durissus terrificus, is a heterodimeric phospholipase a(2) (ec 3.1.1.4), which blocks the release of acetylcholine from peripheral neurons. we previously have suggested the existence of a 48 kda crotoxin-binding protein in the presynaptic membranes of the electric organ of torpedo marmorata. here, we report the purification and characterization of this protein that we called the crotoxin acceptor protein from torpedo (cap ... | 2003 | 12657321 |
| solution structure of crotamine, a na+ channel affecting toxin from crotalus durissus terrificus venom. | crotamine is a component of the venom of the snake crotalus durissus terrificus and it belongs to the myotoxin protein family. it is a 42 amino acid toxin cross-linked by three disulfide bridges and characterized by a mild toxicity (ld50 = 820 micro g per 25 g body weight, i.p. injection) when compared to other members of the same family. nonetheless, it possesses a wide spectrum of biological functions. in fact, besides being able to specifically modify voltage-sensitive na+ channel, it has bee ... | 2003 | 12709056 |
| renal effects of supernatant from macrophages activated by crotalus durissus cascavella venom: the role of phospholipase a2 and cyclooxygenase. | in brazil, the genus crotalus is responsible for approximately 1500 cases of snakebite annually. the most common complication in the lethal cases is acute renal failure, although the mechanisms of the damaging effects are not totally understood. in this work, we have examined the renal effects caused by a supernatant of macrophages stimulated by crotalus durissus cascavella venom as well the potential role of phospholipase a2 and cyclo-oxygenase. rat peritoneal macrophages were collected and pla ... | 2003 | 12710592 |
| inflammatory oedema induced by phospholipases a2 isolated from crotalus durissus sp. in the rat dorsal skin: a role for mast cells and sensory c-fibers. | the ability of the phospholipases a(2) (pla(2)s) from crotalus durissus cascavella, crotalus durissus collilineatus and crotalus durissus terrificus venoms and crotapotin to increase the vascular permeability in the rat skin as well as the contribution of both mast cells and sensory c-fibers have been investigated in this study. vascular permeability was measured as the plasma extravascular accumulation at skin sites of intravenously injected 125i-human serum albumin. intradermal injection of cr ... | 2003 | 12782082 |
| contribution of crotoxin for the inhibitory effect of crotalus durissus terrificus snake venom on macrophage function. | previous work of our group demonstrated that crotalus durissus terrificus venom has a dual effect on macrophage function: it inhibits spreading and phagocytosis and stimulates hydrogen peroxide and nitric oxide production, antimicrobial activity and glucose and glutamine metabolism of these cells. crotalid venom also induces analgesia and this effect is mediated by opioid receptors. the involvement of opioidergic mechanism and the determination of the active component responsible for the inhibit ... | 2003 | 12782091 |
| molecular cloning of a gamma-phospholipase a2 inhibitor from lachesis muta muta (the bushmaster snake). | several endogenous phospholipase a(2) inhibitors (plis) have been purified from the blood plasma of a number of snake species and are classified into three classes (alpha, beta and gamma) according to their structure and specificity. in the present study we have cloned transcripts of a protein homologous to cnf, a gammapli present in crotalus durissus terrificus plasma, that is encoded in the liver of lachesis muta muta (the bushmaster snake), a species evolutionarily related to crotalus. the cd ... | 2003 | 12782092 |
| activation of peripheral atp-sensitive k+ channels mediates the antinociceptive effect of crotalus durissus terrificus snake venom. | the role of peripheral potassium channels on the antinociceptive effect of crotalus durissus terrificus venom, a mixed delta- and kappa-opioid receptor agonist, was investigated in hyperalgesia induced by carrageenin or prostaglandin e(2). rat paw pressure test was applied before and 3 h after the intraplantar (i.pl.) injection of the nociceptive stimuli. oral administration of venom 2 h after carrageenin or prostaglandin e(2) induces antinociception. local pretreatment with 4-aminopyridine and ... | 2003 | 12782185 |
| structural, enzymatic and biological properties of new pla(2) isoform from crotalus durissus terrificus venom. | we isolated a new pla(2) from the crotalus durissus terrificus venom that designated f15, which showed allosteric behavior with a v(max) of 8.5nmol/min/mg and a k(m) of 38.5 mm. the incubated heparin salt of this isolated f15 act a positive allosteric effector by increasing the v(max) to 10.2 nmol/min/mg, with decreasing the v(max) value to 20.5 mm. the crotapotin, on the other hand acts as a negative allosteric effector by increasing the v(max) values to 58.4 mm. f15 also showed high calcium de ... | 2003 | 12875878 |
| convulxin binds to native, human glycoprotein ib alpha. | convulxin (cvx), a c-type snake protein from crotalus durissus terrificus venom, is the quintessential agonist for studies of the collagen receptor, glycoprotein vi (gpvi) and its role in platelet adhesion to collagens. in this study, cvx, purified from venom, behaves as expected, i.e. it binds to platelet gpvi and recombinant human gpvi, induces platelet aggregation and platelet prothrombinase activity, and binds uniquely to gpvi in ligand blots of sds-denatured proteins. nonetheless, we find t ... | 2003 | 12881531 |
| structural and biological characterization of a crotapotin isoform isolated from crotalus durissus cascavella venom. | envenoming by crotalus durissus subspecies leads to coagulation disorders, myotoxicity, neurotoxicity and acute renal failure. the most serious systemic alteration and primary cause of death after snakebite is acute renal failure. in this work, we isolated crotapotin, an acid component (crtp) of crotoxin from crotalus durissus cascavella venom and we investigated its bactericidal and pro-inflammatory activities as well as its renal effects in rat isolated perfused kidneys. crtp was bactericidal ... | 2003 | 12893061 |
| inhibitory potential of crotalus durissus terrificus venom on measles virus growth. | this paper presents the antiviral activity found in a snake with crotalus durissus terrificus venom (cdt), studied by use of microplate inhibition assay, using measles virus (mv). cdt at concentrations below 100 microg/ml showed no cytotoxicity for vero cells. this study shows the optimal conditions for cell treatment and infection. two factors that affect virus binding and infection efficiency were studied: the use of an adsorption step, where infection volume was varied; and the concentration ... | 2003 | 12906885 |
| a new serovar and a new serological variant belonging to salmonella enterica subspecies diarizonae. | description of a new serovar (s. iiib 16:k:e,n,x,z15) and a new serological variant (s. iiib 42:z10:e,n,x,z15:z60 ) belonging to the genus salmonella isolated from stool specimens of brazilian snakes (crotalus durissus). | 2003 | 12937762 |
| studies on the biologic relationship of endotoxin and other toxic proteins. ii. enhancement of susceptibility to snake venom by endotoxin. | 1. injections of sublethal quantities of agkistrodon piscivorus venom into endotoxin-treated rabbits produces a consistent early death. 2. the endotoxin-induced hypersusceptibility state (eihs) to venom is produced by intravenous, intradermal, and intraperitoneal administration of endotoxin. the latency and duration of the eihs vary with the route of administration. 3. eihs is induced by as little as 1 gamma of endotoxin administered intravenously. although the degree of susceptibility was no gr ... | 1962 | 13916025 |
| initial structural analysis of an alpha4beta4 c-type lectin from the venom of crotalus durissus terrificus. | convulxin, an alphabeta c-type lectin, is a potent platelet activator isolated from the venom of the south american rattlesnake crotalus durissus terrificus. it is a 26.5 kda alphabeta heterodimer consisting of two homologous disulfide-linked chains. the crystals belong to space group i4, with unit-cell parameters a = b = 131.61, c = 121.85 a, and diffraction data were collected to 2.7 a. the structure was solved by molecular replacement and the asymmetric unit contains two alphabeta heterodimer ... | 2003 | 14501123 |
| crotapotin induced modification of t lymphocyte proliferative response through interference with pge2 synthesis. | the immunosuppressive property has been demonstrated for the venom of the crotalus durissus terrificus. using a simple, novel method for obtaining crotapotin and phospholipase a2 isoforms from venom, it was possible to demonstrate that the addition of crotapotin to cultures of isolated lymphocytes resulted in a significant inhibition of the cellular proliferative response to concanavalin a. this reduction in blastogenic response of lymphocytes is accompanied by a significant increase in the prod ... | 2003 | 14505945 |
| crystal structure of the platelet activator convulxin, a disulfide-linked alpha4beta4 cyclic tetramer from the venom of crotalus durissus terrificus. | convulxin (cvx), a c-type lectin, isolated from the venom of the south american rattlesnake crotalus durissus terrificus, causes cardiovascular and respiratory disturbances and is a potent platelet activator which binds to platelet glycoprotein gpvi. the structure of cvx has been solved at 2.4a resolution to a crystallographic residual of 18.6% (r(free)=26.4%). cvx is a disulfide linked heterodimer consisting of homologous alpha and beta chains. the heterodimers are additionally linked by disulf ... | 2003 | 14521935 |
| hematological, hemostatic and clinical chemistry disturbances induced by crotalus durissus terrificus snake venom in dogs. | the aim of this study was to investigate the hematological, hemostatic and biochemical disturbances induced by the injection of crotalus durissus terrificus venom in dogs under controlled conditions. for this purpose three groups of animals were used: an experimental group (e), which was injected i.m. with c. durissus terrificus venom (1 mg/kg); and two control groups--antivenom (av) and control (c)--which were injected i.m. with 150 mm nacl. groups e and av were treated i.v. with crotalus antiv ... | 2003 | 14580009 |
| description of the gamonts of a small species of hepatozoon sp. (apicomplexa, hepatozoidae) found in crotalus durissus terrificus (serpentes, viperidae). | a small species of the genus hepatozoon found in a specimen of crotalus durissus terrificus from the botucatu region, são paulo state, brazil is described. the morphologic alterations induced in the snake's erythrocytes by the presence of this parasite are described. morphology and morphometric analyses were performed using the qwin lite 2.5 computerized image analysis system (leica). the hepatozoon possessed a small and short body (8.1+/-0.5 microm long and 3.8+/-0.4 microm wide), with round ex ... | 2004 | 14628216 |
| inhibition of enzymatic and pharmacological activities of some snake venoms and toxins by mandevilla velutina (apocynaceae) aqueous extract. | phospholipases a(2) (pla(2)) are multifunctional proteins which exhibit varied biological activities correlated to the structural diversities of the sub-classes. the crude aqueous extract from subterranean system of mandevilla velutina, a plant found in brazilian savanna, was assayed for its ability to inhibit biological activities of several snake venoms and isolated pla(2)s. the extract induced total inhibition of the phospholipase activity of crotalus durissus terrificus venom and only partia ... | 2003 | 14644557 |
| the thermogenesis of digestion in rattlesnakes. | some snakes have a feeding regime characterized by the infrequent ingestion of relatively large meals, causing impressive increments in post-prandial metabolism. metabolism remains elevated for many days, while digestion proceeds, resulting in considerable investment of time and energy. snakes actively adjust thermoregulatory behavior to raise their body temperature during digestion, exhibiting a post-prandial thermophilic response that accelerates digestion at the expense of higher metabolic ra ... | 2004 | 14718501 |
| direct organogenesis of mandevilla illustris (vell) woodson and effects of its aqueous extract on the enzymatic and toxic activities of crotalus durissus terrificus snake venom. | in order to produce explants of mandevilla illustris (vell) woodson for the "cerrado in vitro", the germplasm bank of unaerp, we carried out a micropropagation protocol using ms or ms/3 medium supplemented with different concentrations of 6-benzyladeninepurine (ba), zeatin or 2-isopentenyladenine for nodal segment growth, and alpha-naphthaleneacetic acid, indole-3-butyric acid (iba) or 1,4 dithiothreitol for rooting. for nodal segments, all the cytokinins tested yielded similar results. however, ... | 2004 | 14727051 |
| absence of myocardial involvement in children victims of crotalus durissus terrificus envenoming. | the myotoxic activity of the venom of crotalus durissus terrificus is demonstrable by increased serum levels of the enzymes creatine kinase (ck), lactate dehydrogenase (ld), and aspartate aminotransferase. serial measurements of ck, ld and their isoenzymes in bite victims showed a pattern similar to that observed in acute myocardial infarction, although the clinical course and electro- and echocardiographic data did not suggest cardiac involvement. these data have raised the hypothesis that crot ... | 2003 | 14757204 |