Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
lmrtx, a basic pla₂ (d49) purified from lachesis muta rhombeata snake venom with enzymatic-related antithrombotic and anticoagulant activity.a basic phospholipase a₂ (lmrtx) isoform was isolated from lachesis muta rhombeata snake venom and partially characterized. the venom was fractionated by molecular exclusion chromatography in ammonium bicarbonate buffer followed by reverse-phase hplc on a c-5 discovery® bio wide column. from liquid chromatography-electrospray ionization/mass spectrometry, the molecular mass of lmrtx was measured as 14.277.50 da. the amino acid sequence showed a high degree of homology between pla₂ lmrtx from l. ...201222750534
crystallographic characterization of functional sites of crotoxin and ammodytoxin, potent β-neurotoxins from viperidae venom.this review will focus on a description of the three-dimensional structures of two β-neurotoxins, the monomeric pla(2) ammodytoxin from vipera ammodytes ammodytes, and heterodimeric crotoxin from crotalus durissus terrificus, and a detailed structural analysis of their multiple functional sites. we have recently determined at high resolution the crystal structures of two natural isoforms of ammodytoxin (atxa and atxc) (saul et al., 2010) which exhibit different toxicity profiles and different an ...201222683534
[experimental efficacy of igy antibodies produced in eggs against the venom of the peruvian snake bothrops atrox].to develop an immunization protocol in order to produce avian igy immunoglobulins against bothrops atrox peruvian snake venom and to evaluate its neutralizing capacity.201222510909
characterization of two vasoactive peptides isolated from the plasma of the snake crotalus durissus terrificus.incubation of plasma from the snake crotalus durissus terrificus (cdtp) with trypsin generated two hypotensive peptides. the primary structure of the peptides was established for two sequences as: (ser-ile-pro-gln-ala-pro-thr-ser-asn-leu-ile-glu-ala-thr-lys) and (lys-pro-asp-ala-asn-gln-val-leu-ile-gln-val-ile-gly-val). these peptides display homology with fragments of albumin from trimeresurus flavoviridis. bolus intra-arterial injection of the purified or the synthetic peptide produced a stron ...201222483415
relationship between the structure and the enzymatic activity of crotoxin complex and its phospholipase a2 subunit: an in silico approach.crotoxin, one of the major toxins of south american rattlesnake crotalus durissus subspecies, is an heterodimeric complex composed of two distinct subunits: a basic phospholipase a(2) (pla(2), cb) and an acidic nontoxic catalytically inactive protein, crotapotin (ca). it's well known that cb has a high enzymatic activity; however the molecular aspects that determine this fact remain unknown. in this study, an in silico approach was used to predict the ca structure by homology modeling, and the c ...201222481077
envenomations by bothrops and crotalus snakes induce the release of mitochondrial alarmins.skeletal muscle necrosis is a common manifestation of viperid snakebite envenomations. venoms from snakes of the genus bothrops, such as that of b. asper, induce muscle tissue damage at the site of venom injection, provoking severe local pathology which often results in permanent sequelae. in contrast, the venom of the south american rattlesnake crotalus durissus terrificus, induces a clinical picture of systemic myotoxicity, i.e., rhabdomyolysis, together with neurotoxicity. it is known that mo ...201222363828
is the population of crotalus durissus (serpentes, viperidae) expanding in brazil?crotalus durissus are found from mexico to northern argentina in a highly disjunct distribution. according to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some north american rattlesnakes. based on the literature, it seems plausible that crotalus durissus expanded their natural distribution in brazil due to floods, but only in a few municipalities in rio de janeiro state. data entries of buta ...201324314146
structure of the polypeptide crotamine from the brazilian rattlesnake crotalus durissus terrificus.the crystal structure of the myotoxic, cell-penetrating, basic polypeptide crotamine isolated from the venom of crotalus durissus terrificus has been determined by single-wavelength anomalous dispersion techniques and refined at 1.7 å resolution. the structure reveals distinct cationic and hydrophobic surface regions that are located on opposite sides of the molecule. this surface-charge distribution indicates its possible mode of interaction with negatively charged phospholipids and other molec ...201324100315
biochemical, functional, structural and phylogenetic studies on intercro, a new isoform phospholipase a2 from crotalus durissus terrificus snake venom.crotoxin is a neurotoxin from crotalus durissus terrificus venom that shows immunomodulatory, anti-inflammatory, antimicrobial, antitumor and analgesic activities. structurally, this toxin is a heterodimeric complex composed by a toxic basic pla2 (crotoxin b or cb) non-covalently linked to an atoxic non-enzymatic and acidic component (crotapotin, crotoxin a or ca). several ca and cb isoforms have been isolated and characterized, showing that the crotoxin venom fraction is, in fact, a mixture of ...201324035779
involvement of formyl peptide receptors in the stimulatory effect of crotoxin on macrophages co-cultivated with tumour cells.crotoxin (ctx) is the main neurotoxic component of crotalus durissus terrificus snake venom. it inhibits tumour growth and modulates the function of macrophages, which are essential cells in the tumour microenvironment. the present study investigated the effect of ctx on the secretory activity of monocultured macrophages and macrophages co-cultivated with llc-wrc 256 cells. the effect of the macrophage secretory activities on tumour cell proliferation was also evaluated. macrophages pre-treated ...201323998941
daily and seasonal activity patterns of free range south-american rattlesnake (crotalus durissus).this study aimed at describing daily and seasonal variation in the activity of a population of south-american rattlesnakes (crotalus durissus) in a savanna like habitat (cerrado) in southeastern brazil. seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of ...201323969850
inhibition of venom serine proteinase and metalloproteinase activities by renealmia alpinia (zingiberaceae) extracts: comparison of wild and in vitro propagated plants.the plant renealmia alpinia has been used in folk medicine to treat snakebites in the northwest region of colombia. in addition, it has been shown to neutralize edema-forming, hemorrhagic, lethal, and defibrin(ogen)ating activities of bothrops asper venom. in this work, extracts of renealmia alpinia obtained by micropropagation (in vitro) and from specimens collected in the wild were tested and compared in their capacity to inhibit enzymatic and toxic activities of a snake venom metalloproteinas ...201323916793
antinociceptive activity of crotoxin in the central nervous system: a functional magnetic resonance imaging study.crotoxin, the main neurotoxic component of the venom of south american rattlesnake (crotalus durissus terrificus), is reported to have potent antinociceptive activity. several authors have shown mainly in behavioral pain models that crotoxin induces antinociceptive effects, supposed to be mediated by actions on the central nervous system. the antinociceptive effects of crotoxin (45 μg/kg ip) in rats were verified in this study by increased response latencies in a hargreaves test and tail flick t ...201323916599
description of three new species of hepatozoon (apicomplexa, hepatozoidae) from rattlesnakes (crotalus durissus terrificus) based on molecular, morphometric and morphologic characters.hepatozoon spp. are commonly found infecting snakes. since the latter are parasitized by diverse forms and data in the literature show divergence, we studied hepatozoon spp. diversity on crotalus durissus terrificus snakes using both molecular and morphological approaches. naturally infected animals were employed. blood was collected, blood smears were prepared and an aliquot was stored at -20°c for dna extraction. five specimens of c. durissus terrificus were selected, each of them infected wit ...201323867148
the evolutionary implications of hemipenial morphology of rattlesnake crotalus durissus terrificus (laurent, 1768) (serpentes: viperidae: crotalinae).most amniotes vertebrates have an intromittent organ to deliver semen. the reptile sphenodon and most birds lost the ancestral penis and developed a cloaca-cloaca mating. known as hemipenises, the copulatory organ of squamata shows unique features between the amniotes intromittent organ. they are the only paired intromittent organs across amniotes and are fully inverted and encapsulated in the tail when not in use. the histology and ultrastructure of the hemipenes of crotalus durissus rattlesnak ...201323840551
bilateral posterior circulation stroke secondary to a crotalid envenomation: case report.snake bite envenoming is a disease with potential serious neurological complications. we report a case of an adolescent who was bitten by a rattlesnake and developed bilateral posterior circulation stroke. the rattlesnake was later identified as being crotalus durissus terrificus. stroke was probably due to toxic vasculitis or toxin-induced vascular spasm and endothelial damage.201323740059
coagulopathy as the main systemic manifestation after envenoming by a juvenile south american rattlesnake (crotalus durissus terrificus): case report.rattlesnake bites in brazil are generally caused by adult individuals, with most of the envenomed patients showing systemic manifestations that include varying degrees of neurotoxicity (acute myasthenia), rhabdomyolysis and coagulopathy, with only mild or no local manifestations. we report a case of envenoming by a juvenile south american rattlesnake (crotalus durissus terrificus) that involved coagulopathy as the main systemic manifestation.201323713821
peripheral kappa and delta opioid receptors are involved in the antinociceptive effect of crotalphine in a rat model of cancer pain.cancer pain is an important clinical problem and may not respond satisfactorily to the current analgesic therapy. we have characterized a novel and potent analgesic peptide, crotalphine, from the venom of the south american rattlesnake crotalus durissus terrificus. in the present work, the antinociceptive effect of crotalphine was evaluated in a rat model of cancer pain induced by intraplantar injection of walker 256 carcinoma cells. intraplantar injection of tumor cells caused the development o ...201323628488
viperid venom glands with defective venom production. morphological study.the venom of viperid snakes is collected monthly at butantan institute for research purposes and production of antivenoms. here we describe histological and ultrastructural changes on crotalus durissus terrificus and bothrops sp. venom glands with defective venom production. secretory tubules commonly showed partial or total obliteration of their lumina by masses of necrotic cells and cellular debris. secretory cells showed varying degrees of degenerative and/or metaplastic alterations seriously ...201323583664
characterization of anti-crotalic antibodies.crotalus durissus terrificus, c. d. collilineatus, c. d. cascavella and c. d. marajoensis are responsible minor but severe snake bites in brazil. the venoms of these snakes share the presence of crotoxin, a neurotoxin comprising of two associated components, crotapotin and phospholipase a2 (pla2). treatment of the victims with specific antiserum is the unique effective therapeutic measure. the ability of anti-crotalus antisera produced by the routine using crude venom to immunize horses or purif ...201323402840
ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen uptake, specific dynamic action or growth in the rattlesnake crotalus durissus.the morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. a possible functional significance for this intra-cardiac shunt has been debated for almost a century. unilateral left vagotomy rendered the single effective pulmonary artery of the south american rattlesnake, crotalus durissus, unable to adjust the magnitude of blood flow to the lung. the higher con ...201323393283
individual venom profiling of crotalus durissus terrificus specimens from a geographically limited region: crotamine assessment and captivity evaluation on the biological activities.crotalus durissus terrificus (cdt) venom major components comprise crotoxin, crotamine, gyroxin and convulxin. crotamine exerts a myotoxic action, among others, but its expression varies even amid snakes from the same region. biochemical, enzymatic and pharmacological variations of venoms may be associated with the geography, climate, gender, age, and diet, as well as captivity time and venom extraction intervals. the present study aimed to characterize the cdt venom from the botucatu region, (s ...201323380403
inhibitory effect of crotalus durissus terrificus venom on chronic edema induced by injection of bacillus calmette-guérin into the footpad of mice.in this study, we evaluated the effect of the crotalus durissus terrificus (cdt) venom on the chronic paw edema induced by the injection of bacillus calmette-guérin (bcg) into the footpad of mice. the bcg injection evoked chronic edema, which was significantly diminished in animals treated subcutaneously (s.c.) with cdt venom 1 h before or after the bcg injection. this inhibition persisted throughout the evaluation period (15 days). in mice injected with cdt venom 6 or 11 days after injection of ...201323246578
growth inhibitory effects and molecular mechanisms of crotoxin treatment in esophageal eca-109 cells and transplanted tumors in nude mice.to investigate the antitumor actions of the crotalus durissus neurotoxin (crotoxin) on human esophageal carcinoma (eca-109) cells in vitro and transplanted esophageal eca-109 tumors in nude mice.201323202800
development of snake-directed antipredator behavior by wild white-faced capuchin monkeys: i. snake-species discrimination.young animals are known to direct alarm calls at a wider range of species than adults. our field study examined age-related differences in the snake-directed antipredator behavior of infant, juvenile, and adult white-faced capuchin monkeys (cebus capucinus) in terms of alarm calling, looking behavior, and aggressive behavior. in the first experiment, we exposed infant and juvenile white-faced capuchins to realistic-looking inflatable models of their two snake predators, the boa constrictior (boa ...201323229464
biochemical and biological characterization of two serine proteinases from colombian crotalus durissus cumanensis snake venom.two clotting serine proteinases, named cdc si and cdc sii, were isolated and characterized for the first time from colombian crotalus durissus cumanensis snake venom. the enzymes were purified using two chromatographic steps: molecular exclusion on sephacryl s-200 and rp-hplc on c8 column. the molecular masses of the proteins, determined by maldi-tof mass spectrometry, were 28,561.4 and 28,799.2 da for cdc si and cdc sii, respectively. the aim of the present study was to evaluate enzymatic, coag ...201323178323
malformations in neotropical viperids: qualitative and quantitative analysis.malformations can occur in all living species, but there is little information about anomalies that occur in snakes and their frequency. this study assessed malformations in newborn south american pit vipers (bothrops jararaca) and south american rattlesnakes (crotalus durissus) from wild captured pregnant females (240 and 35 litters, respectively). newborn snakes were measured, weighed, sexed and studied grossly and by radiography for the presence of malformations. ninety-five malformed pit vip ...201323885804
in vitro antiophidian mechanisms of hypericum brasiliense choisy standardized extract: quercetin-dependent neuroprotection.the neuroprotection induced by hypericum brasiliense choisy extract (hbe) and its main active polyphenol compound quercetin, against crotalus durissus terrificus (cdt) venom and crotoxin and crotamine, was enquired at both central and peripheral mammal nervous system. cdt venom (10 μg/ml) or crotoxin (1 μg/ml) incubated at mouse phrenic nerve-diaphragm preparation (pnd) induced an irreversible and complete neuromuscular blockade, respectively. crotamine (1 μg/ml) only induced an increase of musc ...201324490174
[afibrinogenemia secondary to crotalid snake bite (crotalus durissus terrificus)]. 20133241945
unraveling the antifungal activity of a south american rattlesnake toxin crotamine.crotamine is a highly basic peptide from the venom of crotalus durissus terrificus rattlesnake. its common gene ancestry and structural similarity with the β-defensins, mainly due to an identical disulfide bond pattern, stimulated us to assess the antimicrobial properties of native, recombinant, and chemically synthesized crotamine. antimicrobial activities against standard strains and clinical isolates were analyzed by the colorimetric microdilution method showing a weak antibacterial activity ...201323022146
toxoid preparation from the venom of crotalus durissus cumanensis (south american rattle snake).a new technique is described for the preparation of crotalus venom toxoid. this method preserves the immunogenicity but eliminates the toxic effects. all the animals vaccinated with crotalus venom toxoid survived when they were injected with raw venom.20133820358
myonecrosis, myoglobinuria and acute renal failure induced by south american rattlesnake (crotalus durissus terrificus) envenomation in brazil.the venom of the brazilian rattlesnake crotalus durissus terrificus is know to have hemolytic and neurotoxic physiopathological activities which may cause acute renal failure with hemoglobinuria and/or methemoglobinuria. as far as we know, no report has been published on the ability of the venom of this rattlesnake species to cause rhabdomyolysis. in the present paper we demonstrate that the venom of brazilian snakes of the genus crotalus can induce systemic myonecrosis. clinical, laboratory and ...20134060176
edema-forming activity of bushmaster (lachesis muta stenophrys) and central american rattlesnake (crotalus durissus durissus) venoms and neutralization by a polyvalent antivenom.the edema effect induced in mice by venoms of crotalus durissus durissus and lachesis muta stenophrys was studied. minimum edema-forming doses were 11 and 5 micrograms, respectively. edema developed very rapidly after injections of both venoms and reached a maximum at 6 hr. neutralizing activity was tested by preincubation of the venoms with polyvalent antivenom. the edema induced by the venom of l. m. stenophrys was partially neutralized, whereas that induced by the venom of c. d. durissus was ...20143992598
phospholipase a2 isolated from the venom of crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope.the flaviviridae family includes several virus pathogens associated with human diseases worldwide. within this family, dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. currently, there are no vaccines or specific antiviral drugs against dengue virus or against most of the viruses of this family. therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses ...201425383618
interaction of the rattlesnake toxin crotamine with model membranes.crotamine is one of the main constituents of the venom of the south american rattlesnake crotalus durissus terrificus. a common gene ancestry and structural similarity with the antimicrobial β-defensins (identical disulfide bond pattern and highly positive net charge) suggested potential antimicrobial activities for this snake toxin. although crotamine demonstrated low activity against both gram-positive and gram-negative bacteria, a pronounced antifungal activity was observed against candida sp ...201424754574
soluble prokaryotic expression and purification of crotamine using an n-terminal maltose-binding protein tag.crotamine is a peptide toxin found in the venom of the rattlesnake crotalus durissus terrificus. interestingly, crotamine demonstrates promising anticancer, antimicrobial, and antifungal activities. the crotamine peptide can also deliver plasmids into rapidly dividing cells, such as cancer and stem cells, and demonstrates potent analgesic effects. efficiently producing crotamine in mammalian cells is difficult because it is both cell-permeable and cytotoxic. prokaryotic expression of this peptid ...201425448388
vipericidins: a novel family of cathelicidin-related peptides from the venom gland of south american pit vipers.cathelicidins are phylogenetically ancient, pleiotropic host defense peptides-also called antimicrobial peptides (amps)-expressed in numerous life forms for innate immunity. since even the jawless hagfish expresses cathelicidins, these genetically encoded host defense peptides are at least 400 million years old. more recently, cathelicidins with varying antipathogenic activities and cytotoxicities were discovered in the venoms of poisonous snakes; for these creatures, cathelicidins may also serv ...201425100358
the biflavonoid morelloflavone inhibits the enzymatic and biological activities of a snake venom phospholipase a2.the biflavonoid morelloflavone has been reported as inhibitor of secretory pla2s (phospholipases a2 from human synovial and bee venom sources); however, its capacity to interact and inhibit snake venom pla2 activities has not been described. in this work we tested the inhibitory ability of morelloflavone on the enzymatic, anticoagulant, myotoxic and edema-inducing activities of a pla2 isolated from crotalus durissus cumanensis venom. the biflavonoid displayed ic50 values of 0.48 mm (95% confiden ...201424995575
intraspecific venom variation in the medically significant southern pacific rattlesnake (crotalus oreganus helleri): biodiscovery, clinical and evolutionary implications.due to the extreme variation of venom, which consequently results in drastically variable degrees of neutralization by crofab antivenom, the management and treatment of envenoming by crotalus oreganus helleri (the southern pacific rattlesnake), one of the most medically significant snake species in all of north america, has been a clinician's nightmare. this snake has also been the subject of sensational news stories regarding supposed rapid (within the last few decades) evolution of its venom. ...201424463169
enzyme specificity and effects of gyroxin, a serine protease from the venom of the south american rattlesnake crotalus durissus terrificus, on protease-activated receptors.gyroxin is a serine protease displaying a thrombin-like activity found in the venom of the south american rattlesnake crotalus durissus terrificus. typically, intravenous injection of purified gyroxin induces a barrel rotation syndrome in mice. the serine protease thrombin activates platelets aggregation by cleaving and releasing a tethered n-terminus peptide from the g-protein-coupled receptors, known as protease-activated receptors (pars). gyroxin also presents pro-coagulant activity suggested ...201424412460
intrahippocampal infusion of crotamine isolated from crotalus durissus terrificus alters plasma and brain biochemical parameters.crotamine is one of the main constituents of the venom of the south american rattlesnake crotalus durissus terrificus. here we sought to investigate the inflammatory and toxicological effects induced by the intrahippocampal administration of crotamine isolated from crotalus whole venom. adult rats received an intrahippocampal infusion of crotamine or vehicle and were euthanized 24 h or 21 days after infusion. plasma and brain tissue were collected for biochemical analysis. complete blood count, ...201425380458
effect of chlorogenic acid (5-caffeoylquinic acid) isolated from baccharis oxyodonta on the structure and pharmacological activities of secretory phospholipase a2 from crotalus durissus terrificus.the aim of this paper was to investigate the effect of chlorogenic acid (5-caffeoylquinic acid, 5cqa), isolated from baccharis oxyodonta, on the structure and pharmacological effect of secretory phospholipase a2 (spla2) from crotalus durissus terrificus. all in vitro and in vivo experiments were conducted using a purified spla2 compared under the same experimental conditions with spla2 : 5cqa. 5cqa induced several discrete modifications in the secondary structure and the hydrophobic characterist ...201425258715
does the rattle of crotalus durissus terrificus reveal its dietary history?environmental devastation threatens the survival of many species, including venomous snakes such as the south american rattlesnake crotalus durissus terrificus. this observation is based on the decrease of snakes collected and donated to brazilian research institutes. nevertheless, some individuals have managed to survive and procreate. the question is how these snakes are adapting in these new environmental conditions.201425540653
crotoxin induces apoptosis and autophagy in human lung carcinoma cells in vitro via activation of the p38mapk signaling pathway.crotoxin (crtx) is the primary toxin in south american rattlesnake (crotalus durissus terrificus) venom, and exhibits antitumor and other pharmacological actions in vivo and in vitro. here, we investigated the molecular mechanisms of the antitumor action of crtx in human lung carcinoma cells in vitro.201425132339
loss of the ability to control right-to-left shunt does not influence the metabolic responses to temperature change or long-term fasting in the south american rattlesnake crotalus durissus.abstract in the undivided ventricle of noncrocodilian reptiles, the blood perfusing the systemic circulation is a controlled combination of oxygenated pulmonary blood, flowing from left to right across the heart, and relatively deoxygenated systemic blood, flowing from right to left. a clear inverse correlation has been experimentally established between metabolic demand and the magnitude of right-to-left cardiac shunt in several reptile groups. unilateral left vagotomy renders the single effect ...201424940921
compartment syndrome after south american rattlesnake (crotalus durissus terrificus) envenomation.in order to report the outcome of a patient who developed compartment syndrome after south american rattlesnake (crotalus durissus terrificus) envenomation, confirmed by subfascial pressure measurement and magnetic resonance imaging (mri).201424940645
insights on the structure of native cnf, an endogenous phospholipase a2 inhibitor from crotalus durissus terrificus, the south american rattlesnake.several snake species possess endogenous phospholipase a2 inhibitors (sbplis) in their blood plasma, the primary role of which is protection against an eventual presence of toxic phospholipase a2 (pla2) from their venom glands in the circulation. these inhibitors have an oligomeric structure of, at least, three subunits and have been categorized into three classes (α, β and γ) based on their structural features. sbγplis have been further subdivided into two subclasses according to their hetero o ...201424820993
the intrahippocampal infusion of crotamine from crotalus durissus terrificus venom enhances memory persistence in rats.previous research has shown that crotamine, a toxin isolated from the venom of crotalus durissus terrificus, induces the release of acetylcholine and dopamine in the central nervous system of rats. particularly, these neurotransmitters are important modulators of memory processes. therefore, in this study we investigated the effects of crotamine infusion on persistence of memory in rats. we verified that the intrahippocampal infusion of crotamine (1 μg/μl; 1 μl/side) improved the persistence of ...201424813333
crotoxin from crotalus durissus terrificus snake venom induces the release of glutamate from cerebrocortical synaptosomes via n and p/q calcium channels.crotoxin (crtx), the main toxin in the venom of crotalus durissus terrificus snake, is a heterodimer with a basic subunit, cb, and an acidic subunit, ca. cb is a phospholipase a2 that depends on ca to specifically bind to the cell membrane. this toxin acts in the central nervous system (cns) causing chronic seizure effects and other cytotoxic effects. here, we report its action on glutamate release in rat cerebral cortex synaptosomes. aiming at a better understanding of the mechanism of action o ...201424751366
an evaluation of 3-rhamnosylquercetin, a glycosylated form of quercetin, against the myotoxic and edematogenic effects of spla 2 from crotalus durissus terrificus.this paper shows the results of quercitrin effects on the structure and biological activity of secretory phospholipase (spla2) from crotalus durissus terrificus, which is the main toxin involved in the pharmacological effects of this snake venom. according to our mass spectrometry and circular dichroism results, quercetin was able to promote a chemical modification of some amino acid residues and modify the secondary structure of c. d. terrificus spla2. moreover, molecular docking studies showed ...201424696848
crotalus durissus collilineatus venom induces tnf- α and il-10 production in human peripheral blood mononuclear cells.snake venom has been the subject of numerous studies in an attempt to find properties and biological effects that may be beneficial to man. in this study we evaluated in vitro the effects of crotalus durissus terrificus (cdt) and crotalus durissus collilineatus (cdc) venom in human peripheral blood mononuclear cells (pbmcs). at 24 h, a significant decrease of viable cells was observed in cells stimulated with the cdc venom at 0.0005 mg/ml and 0.005 mg/ml compared to the negative control. at 48 h ...201424563803
membrane-modifying properties of crotamine, a small peptide-toxin from crotalus durissus terifficus venom.crotamine is a small, highly basic myotoxin from the venom of the south american rattlesnake crotalus durissus terifficus. it is structurally well defined and exhibits some similarities with the β-defensins of vertebrates. an amazing variety of functions and targets that range from analgesia and tumor-related activity to cell penetration have been associated with crotamine. similar to defensins, it had been argued that crotamine has antimicrobial activity, and this supposition was recently prove ...201424513454
isolation and biochemical characterization of a γ-type phospholipase a2 inhibitor from crotalus durissus collilineatus snake serum.in the present work, we describe the isolation and partial structural and biochemical characterization of the first phospholipase a2 inhibitor (γpli) from crotalus durissus collilineatus (cdc) snake serum. initially, the cdc serum was subjected to a q-sepharose ion exchange column, producing six peaks at 280 nm absorbance (q1-q6). subsequently, q4 fraction was submitted to affinity chromatography with immobilized pla2 bnsp-7, a step that resulted in two fractions (nhs-1 and nhs-2). the latter co ...201424513130
a new structurally atypical bradykinin-potentiating peptide isolated from crotalus durissus cascavella venom (south american rattlesnake).venom glands of some snakes synthesize bradykinin-potentiating peptides (bpp's) which increase bradykinin-induced hypotensive effect and decrease angiotensin i vasopressor effect by angiotensin-converting enzyme (ace) inhibition. the present study shows a new bpp (bpp-cdc) isolated from crotalus durissus cascavella venom: pro-asn-leu-pro-asn-tyr-leu-gly-ile-pro-pro. although bpp-cdc presents the classical sequence ipp in the c-terminus, it has a completely atypical n-terminal sequence, which sho ...201425091347
parasitological and immunological diagnoses from feces of captive-bred snakes at vital brazil institute.fecal samples from 56 snakes at the vital brazil institute, in the city of niterói, rio de janeiro, were tested using the sedimentation and flotation techniques to investigate the evolutionary forms of parasites such as helminths and protozoa, and using enzyme immunoassay techniques to detect antigens of cryptosporidium sp. and giardia sp. among the animals tested, 80.3% were positive for parasites. out of these, there were 16 bothrops jararaca, 16 b. jararacussu and 13 crotalus durissus. the pr ...201425054488
effects of n-acetyl-l-cysteine on redox status and markers of renal function in mice inoculated with bothrops jararaca and crotalus durissus terrificus venoms.renal dysfunction is an important aggravating factor in accidents caused by crotalus durissus terrificus (cdt) and bothrops jararaca (bj) bites. n-acetyl-l-cysteine (nac) is well known as a nephroprotective antioxidant with low toxicity. the present study investigated the effects of nac on redox status and markers of renal function in mice that received vehicle (controls) or venoms (v) of cdt and bj. in controls nac promoted hypercreatinemia, hypouremia, hyperosmolality with decreased urea in ur ...201424412461
anti-inflammatory potential of zootherapeutics derived from animals used in brazilian traditional medicine.animals are used for the treatment of diseases caused by inflammatory processes, although few studies evaluate their potential for these purposes.201425026349
inhibition of inducible nitric oxide synthase-derived nitric oxide as a therapeutical target for acute pancreatitis induced by secretory phospholipase a2.nitric oxide is a key signalling molecule in the pathogenesis of inflammation, but its role in acute pancreatitis and related abdominal pain induced by secretory phospholipase a2 (spla2 ) from crotalus durissus terrificus (cdt) venom has not been investigated.201424166730
expression of a new serine protease from crotalus durissus collilineatus venom in pichia pastoris and functional comparison with the native enzyme.snake venom serine proteases (svsps) act primarily on plasma proteins related to blood clotting and are considered promising for the treatment of several hemostatic disorders. we report the heterologous expression of a serine protease from crotalus durissus collilineatus, named collinein-1, in pichia pastoris, as well as the enzymatic comparative characterization of the toxin in native and recombinant forms. the complementary dna (cdna) encoding collinein-1 was amplified from cdna library of c. ...201526227411
new immunization protocol to produce crotalic antivenom combining crotalus durissus terrificus venom and its pla2.antivenoms are usually obtained by animal immunization with successive inoculations of increasing sublethal amounts of venom, which may impair the animal health. the high lethality of venom requires prolonged immunization plans with small amounts of venom. thus, we propose an alternative plan that includes a pre-immunization of the animal with phospholipase a2, the main crotoxin component, which is responsible for the whole venom lethality. for comparison, three different immunization schemes we ...201525453603
blood oxygen affinity increases during digestion in the south american rattlesnake, crotalus durissus terrificus.digesting snakes experience massive increases in metabolism that can last for many days and are accompanied by adjustments in the oxygen transport cascade. accordingly, we examined the oxygen-binding properties of the blood in the south american rattlesnake (crotalus durissus terrificus) during fasting and 24 and 48h after the snakes have ingested a rodent meal corresponding to 15% (±2%) of its own body mass. in general, oxygen-hemoglobin (hb-o2) affinity was significantly increased 24h post-fee ...201525446935
first crotoxin-like phospholipase a(2) complex from a new world non-rattlesnake species: nigroviriditoxin, from the arboreal neotropical snake bothriechis nigroviridis.bothriechis nigroviridis is an arboreal neotropical pitviper found in costa rica and panamá. a previous proteomic profiling of its venom revealed the presence of proteins with homology to the a and b subunits of crotoxin/mojave toxin, a heterodimeric phospholipase a2 (pla2) complex only described in rattlesnake venoms (genera crotalus and sistrurus). the native crotoxin-like heterodimer, named nigroviriditoxin, and its a and b subunits were isolated in the present work, and the complete amino ac ...201525434534
assessing the influence of mechanical ventilation on blood gases and blood pressure in rattlesnakes.to characterize the impact of mechanical positive pressure ventilation on heart rate (hr), arterial blood pressure, blood gases, lactate, glucose, sodium, potassium and calcium concentrations in rattlesnakes during anesthesia and the subsequent recovery period.201525174935
pegylation: a successful approach to improve the biopharmaceutical potential of snake venom thrombin-like serine protease.pegylation is considered a successful technique to enhance the therapeutic and biotechnological potentials of peptides, proteins, toxins and drugs. the conjugation of polyethylene glycol (peg) increases the size and molecular weight of conjugated molecule and improves its pharmacokinetics and pharmacodinamics by increasing water solubility, protecting from enzymatic degradation, reducing renal clearance and limiting immunogenic and antigenic reactions. these features are very useful for therapeu ...201526458403
oxygenation properties and isoform diversity of snake hemoglobins.available data suggest that snake hemoglobins (hbs) are characterized by a combination of unusual structural and functional properties relative to the hbs of other amniote vertebrates, including oxygenation-linked tetramer-dimer dissociation. however, standardized comparative data are lacking for snake hbs, and the hb isoform composition of snake red blood cells has not been systematically characterized. here we present the results of an integrated analysis of snake hbs and the underlying α- and ...201526354849
bordonein-l, a new l-amino acid oxidase from crotalus durissus terrificus snake venom: isolation, preliminary characterization and enzyme stability.crotalus durissus terrificus venom (cdtv) is one of the most studied snake venoms in brazil. despite presenting several well known proteins, its l-amino acid oxidase (laao) has not been studied previously. this study aimed to isolate, characterize and evaluate the enzyme stability of bordonein-l, an laao from cdtv.201526273287
a new phospholipase a₂ from lachesis muta rhombeata: purification, biochemical and comparative characterization with crotoxin b.phospholipases a2 (pla2s) are enzymes responsible for inflammatory effects, edema formation, myotoxicity, neurotoxicity and other manifestations from envenoming. in this paper we report the isolation and biochemical characterization of lmr-pla2, the first acidic pla2 found in lachesis muta rhombeata venom. furthermore, this study compared biological effects of lmr-pla2 and crotoxin b (cb), a pla2 from crotalus durissus terrificus venom. lmr-pla2 was isolated by molecular exclusion and reversed p ...201526145564
p9a(cdt-pla2) from crotalus durissus terrificus as good immunogen to be employed in the production of crotalic anti-pla2 igg.four proteins with phospholipase a2 (pla2) activity, designated p9a(cdt-pla2), p9b(cdt-pla2), p10a(cdt-pla2) and p10b(cdt-pla2) were purified from the venom of crotalus durissus terrificus by two chromatographic steps: a gel filtration and reversed phase hplc. the profile obtained clearly shows that three of them have a similar abundance. the molecular mass, 14193.8340da for p9a(cdt-pla2), 14134.9102da for p9b(cdt-pla2), 14242.6289da for p10a(cdt-pla2) and 14183.8730da for p10b(cdt-pla2), were i ...201526129711
new insights into the structural characteristics of irradiated crotamine.since ionizing radiation has the potential to alter the molecular structure and affect the biological properties of biomolecules, it has been successfully employed to attenuate animal toxins. the present study aimed to characterize the structural modifications on irradiated crotamine, a toxin from crotalus durissus terrificus venom, using circular dichroism (cd), fluorescence, fourier transformed infrared spectroscopy (ftir), atomic force microscopy (afm) and differential scanning calorimetry (d ...201526029245
caryospora bigenetica (apicomplexa: eimeriidae) in south america: new hosts and distribution records.the coccidian caryospora bigenetica was first described in the snake crotalus horridus (viperidae) from united states of america. this study represents the first record of the occurrence of c. bigenetica in snakes in south america. feces were sampled between november 2013 and may 2014 from 256 wild snakes maintained in scientific breeding facilities in the states of mato grosso do sul (ms; n = 214) and rio de janeiro (rj; n = 42), brazil. caryospora bigenetica was found in 14 (5.6%) snakes, all ...201525909262
crotoxin from crotalus durissus terrificus is able to down-modulate the acute intestinal inflammation in mice.inflammatory bowel diseases (ibd) is the result of dysregulation of mucosal innate and adaptive immune responses. factors such as genetic, microbial and environmental are involved in the development of these disorders. accordingly, animal models that mimic human diseases are tools for the understanding the immunological processes of the ibd as well as to evaluate new therapeutic strategies. crotoxin (ctx) is the main component of crotalus durissus terrificus snake venom and has an immunomodulato ...201525853847
massive muscular infection by a sarcocystis species in a south american rattlesnake (crotalus durissus terrificus).massive numbers of sarcocysts of a previously undescribed species of sarcocystis were observed in the skeletal muscles throughout the body of an adult, female south american rattlesnake (crotalus durissus terrificus). examination of tissue sections by light microscopy demonstrated that sarcocysts were present in 20 to 40% of muscle fibers from 5 sampled locations. sarcocysts were not present in cardiac muscle, smooth muscle, or other organs. sarcocysts were 0.05-0.15 mm wide, had variable length ...201525658773
neuromuscular effects of venoms and crotoxin-like proteins from crotalus durissus ruruima and crotalus durissus cumanensis.a myographic study was performed to compare the neuromuscular effects of venoms and crotoxin-like proteins from crotalus durissus ruruima and crotalus durissus cumanensis in mice phrenic-diaphragm preparation. it was concluded that both venoms present neurotoxic activity as a consequence of their crotoxin content. furthermore, crotoxin from c.d. cumanensis is more potent than that from c.d. ruruima venom. at the concentration range in which both venoms express neurotoxic activity, only c.d. cuma ...201525598498
identification of crotamine in the venom of crotalus durissus collilineatus by three different methods.the use of mice for the identification of crotamine has been the motive of discussions of bioethical character and technical (efficiency), so that a reassessment of the use of animals in experiments is global trend the search for alternative tests. the objective of this study was to standardize a method for hplc-pda to identify the presence of crotamine in the venom of rattlesnakes, aiming to propose an alternative methodology to reduce or replace the use of animals. the cdc was evaluated as to ...201525553594
myocardial damage induced by tropical rattlesnake (crotalus durissus terrificus) venom in rats.this article describes the light and electron microscopic appearance of the rat myocardium at various time intervals after the administration of crotalus durissus terrificus venom by intraperitoneal route. the crotalid envenomation produced small foci of myocardial necrosis scattered throughout the base of the ventricles. these lesions were predominantly perivascular and were associated with slight to moderate interstitial edema as well as infiltration of mononuclear cells and of a great number ...201525990526
biodegradable microparticles containing crotamine isolated from crotalus durissus terrificus display antileishmanial activity in vitro.to evaluate antileishmanial activity of crotamine, a toxin isolated from crotalus durissus terrificus, in solution form and encapsulated in biodegradable microparticles in vitro.201525633844
in vitro activity of phospholipase a2 and of peptides from crotalus durissus terrificus venom against amastigote and promastigote forms of leishmania (l.) infantum chagasi.american visceral leishmaniasis is caused by the intracellular parasite leishmania (l.) infantum chagasi, and transmitted by the sand fly lutzomyia longipalpis. since treatment is based on classical chemotherapeutics with significant side effects, the search for new drugs remains the greatest global challenge. thus, this in vitro study aimed to evaluate the leishmanicidal effect of crotalus durissus terrificus venom fractions on promastigote and amastigote forms of leishmania (l.) infantum chaga ...201526609302
molecular identification of spirometra spp. (cestoda: diphyllobothriidae) in some wild animals from brazil.species of the genus spirometra are diphyllobothriid tapeworms with complex life cycles and are involved in human sparganosis, a neglected disease that affects individuals worldwide. although some species were reported in wild felids and human cases of sparganosis were described in brazil, the biology and taxonomy of these parasites are poorly understood. in the present study, samples of diphyllobothriids (eggs and/or proglottids) obtained from the stools of wild carnivores (leopardus pardalis a ...201627235572
isolation, characterization and screening of the in vitro cytotoxic activity of a novel l-amino acid oxidase (laaocdt) from crotalus durissus terrificus venom on human cancer cell lines.an l-amino acid oxidase (laaocdt) from crotalus durissus terrificus venom was purified to homogeneity in a two-step procedure using molecular exclusion on sephadex g-75, followed by phenyl sepharose ff chromatography. the molecular mass of the purified enzyme was 113 kda, as determined by sds-page under reducing conditions. laaocdt showed amino acid homology to other l-amino acid oxidases isolated from different snake venoms. the comparative analysis of the internal peptide sequences of the nnpg ...201627317870
immunochemical analysis of a snake venom phospholipase a2 neurotoxin, crotoxin, with monoclonal antibodies.crotoxin is the major neurotoxic component of the venom of the south american rattlesnake, crotalus durissus terrificus. the crotoxin molecule is composed of two subunits: a basic and weakly toxic phospholipase a2 (pla2) called component-b (cb), and an acidic, nonenzymatic and nontoxic subunit called component-a (ca). crotoxin exists as a mixture of several isoforms (or variants) resulting from the association of several subunit isoforms. we prepared monoclonal antibodies (mabs) against each iso ...20161378931
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 ...201611005268
a new heterologous fibrin sealant as a scaffold to cartilage repair-experimental study and preliminary results.autologous fibrin gel is commonly used as a scaffold for filling defects in articular cartilage. this biomaterial can also be used as a sealant to control small hemorrhages and is especially helpful in situations where tissue reparation capacity is limited. in particular, fibrin can act as a scaffold for various cell types because it can accommodate cell migration, differentiation, and proliferation. despite knowledge of the advantages of this biomaterial and mastery of the techniques required f ...201626264444
flow cytometric characterization of peripheral blood leukocyte populations of 3 neotropical snake species: boa constrictor, bothrops jararaca, and crotalus durissus.the reptilian immune system is represented by innate, humoral, and cell-mediated mechanisms, involving different types of blood leukocytes. the development of optimized methods for the advanced study of origin and function of reptilian blood leukocytes is needed.201627213293
endogenous phospholipase a2 inhibitors in snakes: a brief overview.the blood plasma of numerous snake species naturally comprises endogenous phospholipase a2 inhibitors, which primarily neutralize toxic phospholipases a2 that may eventually reach their circulation. this inhibitor type is generally known as snake blood phospholipase a2 inhibitors (sbplis). most, if not all sbplis are oligomeric glycosylated proteins, although the carbohydrate moiety may not be essential for pla2 inhibition in every case. the presently known sbplis belong to one of three structur ...201628031735
effect of a biostimulatory homeopathic complex on venom production in captive rattlesnakes (crotalus durissus).the purpose of this study was to evaluate the effect of two administration methods of a biostimulatory homeopathic complex (convert h(®)) on the production of fresh and lyophilized venom of rattlesnakes (crotalus durissus) under intensive captivity conditions. sixty snakes were subjected to treatment following a randomized block design. the effects of sex and size were controlled for. thirteen consecutive extractions were performed over 21 months. the first factor considered in the experiment wa ...201627914573
vagal tone regulates cardiac shunts during activity and at low temperatures in the south american rattlesnake, crotalus durissus.the undivided ventricle of non-crocodilian reptiles allows for intracardiac admixture of oxygen-poor and oxygen-rich blood returning via the atria from the systemic circuit and the lungs. the distribution of blood flow between the systemic and pulmonary circuits may vary, based on differences between systemic and pulmonary vascular conductances. the south american rattlesnake, crotalus durissus, has a single pulmonary artery, innervated by the left vagus. activity in this nerve controls pulmonar ...201627294346
identification of antinociceptive fraction of snake venom from crotalus durissus collilineatus crotamine-negative and its acute toxicity evaluation.the crude venom of the snake crotalus durissus collilineatus (cdc) promotes neurological signs and symptoms in accidents involving humans and animals and the victims reports analgesia at the bite site, without tissue destruction. studies shows that cdc has analgesic activity, among others. the crude venom is considered unsuitable for therapeutic purposes, with encouragement to the fractionation and purification of the same. thus, the aim with cdc venom is: to perform fractionation by preparative ...201627720975
crotalphine desensitizes trpa1 ion channels to alleviate inflammatory hyperalgesia.crotalphine is a structural analogue to a novel analgesic peptide that was first identified in the crude venom from the south american rattlesnake crotalus durissus terrificus. although crotalphine's analgesic effect is well established, its direct mechanism of action remains unresolved. the aim of the present study was to investigate the effect of crotalphine on ion channels in peripheral pain pathways. we found that picomolar concentrations of crotalphine selectively activate heterologously ex ...201627434506
inhibition of proteases and phospholipases a2 from bothrops atrox and crotalus durissus terrificus snake venoms by ascorbic acid, vitamin e, and b-complex vitamins.the enzyme inhibition by natural and/ or low-cost compounds may represent a valuable adjunct to traditional serotherapy performed in cases of snakebite, mainly with a view to mitigate the local effects of envenoming. the objective of this study was to evaluate possible interactions between vitamins and enzymes that comprise bothrops atrox and crotalus durissus terrificus venoms, in vitro. proteolysis inhibition assays (substrates: azocasein, collagen, gelatin and fibrinogen), hemolysis, coagulat ...201627737338
direct spinal ventral root repair following avulsion: effectiveness of a new heterologous fibrin sealant on motoneuron survival and regeneration.axonal injuries at the interface between central and peripheral nervous system, such as ventral root avulsion (vra), induce important degenerative processes, mostly resulting in neuronal and motor function loss. in the present work, we have compared two different fibrin sealants, one derived from human blood and another derived from animal blood and crotalus durissus terrificus venom, as a promising treatment for this type of injury. lewis rats were submitted to vra (l4-l6) and had the avulsed r ...201627642524
venom yield and its relationship with body size and fang separation of pit vipers from argentina.the amount of venom that a snake can inject is related to its body size. the body size is related to head size and to the distance between fangs. to correlate snake body size, distance between fangs and distance between puncture wounds with the venom yield (and consequently with the venom dose potentially injected in a single snakebite), we studied these variables in two species of public health importance in south america, bothrops (rhinocerophis) alternatus, and crotalus durissus terrificus. i ...201627546705
rattlesnake phospholipase a2 increases cftr-chloride channel current and corrects ∆f508cftr dysfunction: impact in cystic fibrosis.deletion of phe508 in the nucleotide binding domain (∆f508-nbd1) of the cystic fibrosis transmembrane regulator (cftr; a cyclic amp-regulated chloride channel) is the most frequent mutation associated with cystic fibrosis. this mutation affects the maturation and gating of cftr protein. the search for new high-affinity ligands of cftr acting as dual modulators (correctors/activators) presents a major challenge in the pharmacology of cystic fibrosis. snake venoms are a rich source of natural mult ...201627241308
walker 256 tumor growth suppression by crotoxin involves formyl peptide receptors and lipoxin a₄.we investigated the effects of crotoxin (ctx), the main toxin of south american rattlesnake (crotalus durissus terrificus) venom, on walker 256 tumor growth, the pain symptoms associated (hyperalgesia and allodynia), and participation of endogenous lipoxin a4. treatment with ctx (s.c.), daily, for 5 days reduced tumor growth at the 5th day after injection of walker 256 carcinoma cells into the plantar surface of adult rat hind paw. this observation was associated with inhibition of new blood ves ...201627190493
inhibitory effect of pinostrobin from renealmia alpinia, on the enzymatic and biological activities of a pla2.pinostrobin is a flavanone isolated from renealmia alpinia, a plant used in folk medicine to treat snakebites. we tested the inhibitory ability of pinostrobin on the enzymatic, anticoagulant, myotoxic and edema-inducing activities of a pla2 isolated from crotalus durissus cumanensis venom. the compound displayed ic50 values of 1.76mm and 1.85mm (95% confidence intervals: 1.34-2.18 and 1.21-2.45) on the pla2 enzymatic activity, when either aggregated or monodispersed substrates were used, respect ...201627109758
microscopic agglutination test on captive rattlesnakes : data on serovars and titers.the microscopic agglutination test (mat) is considered the "golden standard" leptospirosis serodiagnostic test, but there is little information about it as it pertains to snakes. to fill this information gap, we provide data on serovars and titers of fifty-six crotalus durissus collilineatus sera samples that tested positive by mat (10.1016/j.actatropica.2016.02.006 (rodrigues et al., 2016) [5]). these data are presented in a table, along with a description of the methodology used for sample col ...201627077089
clinical presentation and management of an aruban rattlesnake bite in the netherlands.bites by aruban rattlesnake (crotalus durissus unicolor) are rare and not known to induce severe envenomations. here, we present a case of a 57 year-old man bitten by his pet aruban rattlesnake (crotalus durissus unicolor). he was admitted to hospital within 15 min. three and a half hours later his fibrinogen concentration decreased to 0.6 g/l (normal: 2.0-4.0). nine hours post-bite, he was treated with polyvalent snake antivenom covering crotalus durissus. three hours later his fibrinogen becam ...201627023827
anti-leptospira spp. antibodies in crotalus durissus collilineatus kept in captivity and its zoonotic relevance.leptospirosis is a worldwide spread zoonosis that can affect all groups of vertebrates, including reptiles. because it has been little studied in snakes, this study focused on determining the occurrence of anti-leptospira spp. antibodies in 64 crotalus durissus collilineatus kept in captivity and on identifying the most common serovars in these animals, using the microscopic agglutination test. of these, almost 90% were positive and there were reactions to the 22 serovars used in the study. the ...201626875762
crotamine stimulates phagocytic activity by inducing nitric oxide and tnf-α via p38 and nfκ-b signaling in raw 264.7 macrophages.crotamine is a peptide toxin found in the venom of the rattlesnake crotalus durissus terrificus and has antiproliferative, antimicrobial, and antifungal activities. herein, we show that crotamine dose-dependently induced macrophage phagocytic and cytostatic activity by the induction of nitric oxide (no) and tumor necrosis factor-alpha (tnf-α). moreover, the crotamineinduced expression of inos and tnf-α is mediated through the phosphorylation of p38 and the nf-κb signaling cascade in macrophages. ...201626818089
heterologous fibrin sealant derived from snake venom: from bench to bedside - an overview.hemostatic and adhesive agents date back to world war ii, when homologous fibrin sealant came onto scene. considering that infectious diseases can be transmitted via human blood, a new heterologous fibrin sealant was standardized in the 1990s. its components were a serine protease (a thrombin-like enzyme) extracted from the venom of crotalus durissus terrificus snakes and a fibrinogen-rich cryoprecipitate extracted from the blood of bubalus bubalis buffaloes. this new bioproduct has been used as ...201728396682
vascular distensibilities have minor effects on intracardiac shunt patterns in reptiles.the different vascular distensibilities of systemic and pulmonary circuits were recently proposed as an important mechanism defining the direction of cardiac shunt and the distribution of cardiac output in vertebrates with undivided cardiac ventricles. in short, the more distensible pulmonary vascular bed was proposed to accommodate a larger portion of the blood ejected from the heart when cardiac output increases. to evaluate this hypothesis, we performed a meta-analysis based on fourteen previ ...201728390664
Refresh
firstprev
12345678
nextlast
Displaying items 501 - 600 of 720