| iron and carbon monoxide attenuate degradation of plasmatic coagulation by crotalus atrox venom. | hypofibrinogenemia is an important clinical consequence following envenomation by crotalus species, usually attenuated or prevented by administration of antivenom. it has been determined that iron and carbon monoxide (co) enhance fibrinogen as a thrombin substrate, likely secondary to conformational changes in molecular structure. we tested the hypothesis that pretreatment of plasma with iron and co could attenuate the effects of exposure to crotalus atrox venom. human plasma was exposed to 0 to ... | 2016 | 26575491 |
| iron and carbon monoxide attenuate crotalus atrox venom-enhanced tissue-type plasminogen activator-initiated fibrinolysis. | in addition to degrading fibrinogen as a source of consumptive coagulopathy, rattlesnake venom has also been demonstrated to enhance fibrinolysis and degrade alpha-2-antiplasmin. the goals of this investigation was to characterize the kinetic fibrinolytic profile of crotalus atrox venom in the absence and presence of tissue-type plasminogen activator (tpa), and to also ascertain if iron and carbon monoxide (co, a positive modulator of alpha-2-antiplasmin) could attenuate venom-enhanced fibrinoly ... | 2016 | 26575490 |
| zebrin ii / aldolase c expression in the cerebellum of the western diamondback rattlesnake (crotalus atrox). | aldolase c, also known as zebrin ii (zii), is a glycolytic enzyme that is expressed in cerebellar purkinje cells of the vertebrate cerebellum. in both mammals and birds, zii is expressed heterogeneously, such that there are sagittal stripes of purkinje cells with high zii expression (zii+), alternating with stripes of purkinje cells with little or no expression (zii-). the patterns of zii+ and zii- stripes in the cerebellum of birds and mammals are strikingly similar, suggesting that it may have ... | 2015 | 25692946 |
| incipient speciation with biased gene flow between two lineages of the western diamondback rattlesnake (crotalus atrox). | we used mitochondrial dna sequence data from 151 individuals to estimate population genetic structure across the range of the western diamondback rattlesnake (crotalus atrox), a widely distributed north american pit viper. we also tested hypotheses of population structure using double-digest restriction site associated dna (ddradseq) data, incorporating thousands of nuclear genome-wide snps from 42 individuals. we found strong mitochondrial support for a deep divergence between eastern and weste ... | 2015 | 25534232 |
| thrombin-dependent incorporation of von willebrand factor into a fibrin network. | attachment of platelets from the circulation onto a growing thrombus is a process involving multiple platelet receptors, endothelial matrix components, and coagulation factors. it has been indicated previously that during a transglutaminase reaction activated factor xiii (fxiiia) covalently cross-links von willebrand factor (vwf) to polymerizing fibrin. bound vwf further recruits and activates platelets via interactions with the platelet receptor complex glycoprotein ib (gpib). in the present st ... | 2014 | 25381443 |
| organotopic organization of the primary infrared sensitive nucleus (lttd) in the western diamondback rattlesnake (crotalus atrox). | pit vipers (crotalinae) have a specific sensory system that detects infrared radiation with bilateral pit organs in the upper jaw. each pit organ consists of a thin membrane, innervated by three trigeminal nerve branches that project to a specific nucleus in the dorsal hindbrain. the known topographic organization of infrared signals in the optic tectum prompted us to test the implementation of spatiotopically aligned sensory maps through hierarchical neuronal levels from the peripheral epitheli ... | 2014 | 24989331 |
| mating systems, reproductive success, and sexual selection in secretive species: a case study of the western diamond-backed rattlesnake, crotalus atrox. | long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. here, we used molecular genetic techniques in a 10-year radio-telemetric investigation ... | 2014 | 24598810 |
| antibody responses to natural rattlesnake envenomation and a rattlesnake toxoid vaccine in horses. | antivenom antibody titers following administration of rattlesnake venom for antivenom production in horses are well documented; however, antivenom antibody titers following natural rattlesnake envenomation in horses are not. antibody titers produced in response to the commercially available rattlesnake venom vaccine are also not published. our study objectives were to measure antivenom antibody titers in rattlesnake-bitten horses and compare them to titers in horses vaccinated with the rattlesna ... | 2013 | 23515015 |
| molecular basis for prey relocation in viperid snakes. | vertebrate predators use a broad arsenal of behaviors and weaponry for overcoming fractious and potentially dangerous prey. a unique array of predatory strategies occur among snakes, ranging from mechanical modes of constriction and jaw-holding in non-venomous snakes, to a chemical means, venom, for quickly dispatching prey. however, even among venomous snakes, different prey handling strategies are utilized, varying from the strike-and-hold behaviors exhibited by highly toxic elapid snakes to t ... | 2013 | 23452837 |
| gape size, its morphological basis, and the validity of gape indices in western diamond-backed rattlesnakes (crotalus atrox). | maximum gape is important to the ecology and evolution of many vertebrates, particularly gape-limited predators, because it can restrict the sizes and shapes of prey that can be eaten. although many cranial elements probably contribute to gape, it is typically estimated from jaw length or jaw width, or occasionally from a combination of these two measures. we measured maximum gape directly for 18 individuals of the western diamond-backed rattlesnake, crotalus atrox. we measured each individual's ... | 2013 | 23108999 |
| directional sensitivity in the thermal response of the facial pit in western diamondback rattlesnakes (crotalus atrox). | recent work published in the accompanying paper used a combination of 3d morphological reconstruction to define optical spread functions and heat transfer physics to study how external heat energy would reach the sensory membrane within the facial pit of pitvipers. the results from all of the species examined indicated asymmetric directional sensitivity, e.g. the pit would preferentially respond to stimuli located below and behind the snake. the present study was intended as a test of these find ... | 2012 | 22786639 |
| specificity analysis of the c-type lectin from rattlesnake venom, and its selectivity towards gal- or galnac-terminated glycoproteins. | the rattlesnake (crotalus atrox) venom lectin is a readily-prepared decameric c-type lectin, specific for gal and galnac. glycan microarray analysis showed it reacted with a wide range of glycans, chiefly recognizing sets of compounds with galβ1-4glcnac (lacnac), α-gal or α-galnac non-reducing termini. its array profile was therefore distinctly different from those of four previously studied mammalian c-type lectins with the same gal/galnac monosaccharide specificity, and it was more broadly rea ... | 2011 | 21805077 |
| nanoscale probing reveals that reduced stiffness of clots from fibrinogen lacking 42 n-terminal bbeta-chain residues is due to the formation of abnormal oligomers. | removal of bbetal-42 from fibrinogen by crotalus atrox venom results in a molecule lacking fibrinopeptide b and part of a thrombin binding site. we investigated the mechanism of polymerization of desbbeta1-42 fibrin. fibrinogen trinodular structure was clearly observed using high resolution noncontact atomic force microscopy. e-regions were smaller in desbbeta1-42 than normal fibrinogen (1.2 nm +/- 0.3 vs. 1.5 nm +/- 0.2), whereas there were no differences between the d-regions (1.7 nm +/- 0.4 v ... | 2009 | 19289066 |
| recurrent hemorrhage after western diamondback rattlesnake envenomation treated with crotalidae polyvalent immune fab (ovine). | recurrent coagulopathy has been observed in patients after rattlesnake envenomation treated with crotalidae polyvalent immune fab (ovine) [fabav]. while recurrent coagulopathy is well documented in the literature, clinically significant sequelae have not been reported. we present a case of recurrent thrombocytopenia after western diamondback envenomation treated with fabav, resulting in an extensive recurrent local hemorrhage. | 2008 | 18608290 |
| tail morphology in the western diamond-backed rattlesnake, crotalus atrox. | the shaker muscles in the tails of rattlesnakes are used to shake the rattle at very high frequencies. these muscles are physiologically specialized for sustaining high-frequency contractions. the tail skeleton is modified to support the enlarged shaker muscles, and the muscles have major anatomical modifications when compared with the trunk muscles and with the tail muscles of colubrid snakes. the shaker muscles have been known for many years to consist of three large groups of muscles on each ... | 2008 | 18553368 |
| proximate developmental mediators of sexual dimorphism in size: case studies from squamate reptiles. | sexual dimorphism in size (sexual size dimorphism; ssd) is nearly ubiquitous, but the relative importance of genetic versus environmental control of ssd is not known for most species. we investigated proximate determinants of ssd in several species of squamate reptiles, including three species of sceloporus lizards and the diamond-backed rattlesnake (crotalus atrox). in natural populations of these species, ssd is caused by sexual differences in age-specific growth. males and females, however, m ... | 2007 | 21672836 |
| cdna cloning and some additional peptide characterization of a single-chain vascular apoptosis-inducing protein, vap2. | vascular apoptosis-inducing proteins (vaps) from hemorrhagic snake venom are apoptosis-inducing toxins targeting vascular endothelial cells. well-characterized vaps consist of disulfide-bridged double chains (ddvaps). the authors previously described a single-chain vap (scvap), vap2 from crotalus atrox, which also induces apoptosis in endothelial cells (masuda et al., 1998, european journal of biochemistry, 253, 36-41). the authors report here the whole cdna sequences and some additional peptide ... | 2007 | 17497365 |
| crystal structures of catrocollastatin/vap2b reveal a dynamic, modular architecture of adam/adamalysin/reprolysin family proteins. | catrocollastatin/vascular apoptosis-inducing protein (vap)2b is a metalloproteinase from crotalus atrox venom, possessing metalloproteinase/disintegrin/cysteine-rich (mdc) domains that bear the typical domain architecture of a disintegrin and metalloproteinase (adam)/adamalysin/reprolysin family proteins. here we describe crystal structures of catrocollastatin/vap2b in three different crystal forms, representing the first reported crystal structures of a member of the monomeric class of this fam ... | 2007 | 17485084 |
| shotgun protein sequencing: assembly of peptide tandem mass spectra from mixtures of modified proteins. | despite significant advances in the identification of known proteins, the analysis of unknown proteins by ms/ms still remains a challenging open problem. although klaus biemann recognized the potential of ms/ms for sequencing of unknown proteins in the 1980s, low throughput edman degradation followed by cloning still remains the main method to sequence unknown proteins. the automated interpretation of ms/ms spectra has been limited by a focus on individual spectra and has not capitalized on the ... | 2007 | 17446555 |
| western diamondback rattlesnakes demonstrate physiological and biochemical strategies for tolerating prolonged starvation. | because of the uncertainty in food resources in nature, all animals face the possibility of imposed periods of fasting (i.e., starvation) at some point in their lives. i investigated physiological and biochemical responses to starvation that occur in a species of rattlesnake known to tolerate successfully prolonged periods of starvation in the wild. sixteen subadult crotalus atrox were fasted for up to 24 wk under controlled conditions simulating their active season. snakes exhibited significant ... | 2006 | 17160877 |
| mechanisms controlling venom expulsion in the western diamondback rattlesnake, crotalus atrox. | although many studies have documented variation in the amount of venom expended during bites of venomous snakes, the mechanistic source of this variation remains uncertain. this study used experimental techniques to examine how two different features of the venom delivery system, the muscle surrounding the venom gland (the compressor glandulae in the rattlesnake) and the fang sheath, could influence venom flow in the western diamondback rattlesnake, crotalus atrox. differential contraction of th ... | 2007 | 17094108 |
| structure-function inferences based on molecular modeling, sequence-based methods and biological data analysis of snake venom lectins. | lectins are a structurally and functionally diverse group of proteins from different sources, capable to recognize and bind specifically carbohydrates. several snake venoms contain calcium-dependent true lectins (svls) that recognize galactose. herein, in order to enlighten some of the structure-function relationships of snake venom lectins (svls), we constructed theoretical models for 10 svls based on the crotalus atrox lectin (cal), the only svl crystal structure available, and compared with o ... | 2006 | 17046438 |
| structural features of the reprolysin atrolysin c and tissue inhibitors of metalloproteinases (timps) interaction. | atrolysin c is a p-i snake venom metalloproteinase (svmp) from crotalus atrox venom, which efficiently degrades capillary basement membranes, extracellular matrix, and cell surface proteins to produce hemorrhage. the tissue inhibitors of metalloproteinases (timps) are effective inhibitors of matrix metalloproteinases which share some structural similarity with the svmps. in this work, we evaluated the inhibitory profile of timp-1, timp-2, and the n-terminal domain of timp-3 (n-timp-3) on the pro ... | 2006 | 16842758 |
| winter profile of plasma sex steroid levels in free-living male western diamond-backed rattlesnakes, crotalus atrox (serpentes: viperidae). | recent field studies on the reproductive ecology of western diamond-backed rattlesnakes (crotalus atrox) from populations in southern arizona showed significant differences in the concentration of plasma sex steroids (testosterone, t; 5alpha-dihydrotestosterone, dht; and 17beta-estradiol, e2) throughout the active season (march-october), and peak levels were coincident with the two mating periods (late summer and early spring). there is, however, no information on levels of sex steroids during w ... | 2006 | 16828091 |
| crystallization and preliminary x-ray crystallographic analysis of two vascular apoptosis-inducing proteins (vaps) from crotalus atrox venom. | vaps are haemorrhagic snake-venom toxins belonging to the reprolysin family of zinc metalloproteinases. in vitro, vaps induce apoptosis specifically in cultured vascular endothelial cells. vaps have a modular structure that bears structural homology to mammalian adams (a disintegrin and metalloproteinases). vap1 is a homodimer with a mw of 110 kda in which the monomers are connected by a single disulfide bridge. vap2 is homologous to vap1 and exists as a monomer with a mw of 55 kda. in the curre ... | 2006 | 16820695 |
| from physiology to fitness: the costs of a defensive adaptation in rattlesnakes. | the costs of using and maintaining presumed adaptations are unknown for most animals. energetically expensive traits, such as some agonistic and antipredator behaviors in animals, may incur trade-offs with other aspects of an animal's life history, such as feeding and reproduction. however, infrequent and brief use may reduce the costs of vigorous behaviors. the shaker muscles in the tails of rattlesnakes are an excellent system for studying the potential costs of a specialized defensive system. ... | 2006 | 16380934 |
| the ontogeny of contractile performance and metabolic capacity in a high-frequency muscle. | high-performance muscles such as the shaker muscles in the tails of western diamond-backed rattlesnakes (crotalus atrox) are excellent systems for studying the relationship between contractile performance and metabolic capacity. we observed that shaker muscle contraction frequency increases dramatically with growth in small individuals but then declines gradually in large individuals. we tested whether metabolic capacity changed with performance, using shaker muscle contraction frequency as an i ... | 2007 | 16380925 |
| effects of food supplementation on the physiological ecology of female western diamond-backed rattlesnakes (crotalus atrox). | food availability is an important factor in the life histories of organisms because it is often limiting and thus can affect growth, mass change, reproduction, and behaviors such as thermoregulation, locomotion, and mating. experimental studies in natural settings allow researchers to examine the effects of food on these parameters while animals are free to behave naturally. the wide variation among organisms in energy demands and among environmental food resources suggest that responses to chan ... | 2005 | 15800735 |
| heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (viperidae: crotalinae). | pitvipers (viperidae: crotalinae) possess thermal radiation receptors, the facial pits, which allow them to detect modest temperature fluctuations within their environments. it was previously thought that these organs were used solely to aid in prey acquisition, but recent findings demonstrated that western diamondback rattlesnakes (crotalus atrox) use them to direct behavioral thermoregulation, suggesting that facial pits might be general purpose organs used to drive a suite of behaviors. to in ... | 2004 | 15531644 |
| integrin beta 4 is a target of rattlesnake venom during inducing apoptosis of vascular endothelial cells. | to find more effective components which can trigger apoptosis in crude rattlesnake venom, and the possible mechanisms by which the venom causes apoptosis in vascular endothelial cells (vecs), we investigated the function of integrin beta4 by using the monoclonal antibody (mab) of this integrin. we added anti-beta4 mab 5 microg.ml(-1) to the cells treated with 2 microg.ml(-1) rattlesnake venom; apoptosis of these cells was completely inhibited 6 h after the treatment. furthermore, the increase of ... | 2004 | 15135325 |
| seasonal steroid hormone levels and their relation to reproduction in the western diamond-backed rattlesnake, crotalus atrox (serpentes: viperidae). | we report seasonal variation in steroid hormone levels in blood samples from free-ranging western diamond-backed rattlesnakes (crotalus atrox), and the relationship between these hormones and events in the reproductive cycle. at a field site in the sonoran desert of south-central arizona, we collected monthly blood samples over the course of two active seasons from 17 radiotelemetered females, and over three active seasons from 103 randomly encountered males. we used radioimmunoassay to measure ... | 2004 | 15081832 |
| x-ray crystal structure of a galactose-specific c-type lectin possessing a novel decameric quaternary structure. | rattlesnake venom lectin (rsl) from the western diamondback rattlesnake (crotalus atrox) is an oligomeric galactose-specific c-type lectin. the x-ray crystal structure of rsl, in complex with lactose and thiodigalactoside, at 2.2 and 2.3 a resolution, respectively, reveals a decameric protein composed of two 5-fold symmetric pentamers arranged in a staggered, back-to-back orientation. each monomer corresponds to a single canonical c-type lectin carbohydrate recognition domain devoid of accessory ... | 2004 | 15049685 |
| [rattlesnake bite poisoning, health damage and treatment in children]. | in mexico, we do not know the exact number of cases and the magnitude of health damage conditioned by poisonous rattlesnake bites, and little relative information exists in pediatric population. | 2009 | 14574752 |
| thermoregulation is the pits: use of thermal radiation for retreat site selection by rattlesnakes. | pitvipers (viperidae: crotalinae) possess unique sensory organs, the facial pits, capable of sensing subtle fluctuations in thermal radiation. prey acquisition has long been regarded as the sole function of the facial pits. however, the ability to sense thermal radiation could also direct thermoregulatory behavior by remotely sensing nearby surface temperatures. using a series of behavioral arenas of varying spatial complexity and ecological relevance, we surveyed the ability of the western diam ... | 2003 | 12819261 |
| resolution of compartment syndrome after rattlesnake envenomation utilizing non-invasive measures. | western diamondback rattlesnake envenomation is usually managed by administration of neutralizing antivenom. the development of compartment syndrome is a rare complication that has sparked considerable debate regarding medical vs. surgical management. we report a case of compartment syndrome resulting from a rattlesnake envenomation, which responded to large doses of neutralizing antivenom given concomitantly with mannitol and hyperbaric oxygen. this regimen obviated the need for surgical fascio ... | 2003 | 12676299 |
| minimal shortening in a high-frequency muscle. | reducing the cost of high-frequency muscle contractions can be accomplished by minimizing cross-bridge cycling or by recycling elastic strain energy. energy saving by contractile minimization has very different implications for muscle strain and activation patterns than by elastic recoil. minimal cross-bridge cycling will be reflected in minimal contractile strains and highly reduced force, work and power output, whereas elastic energy storage requires a period of active lengthening that increas ... | 2003 | 12624164 |
| proteome analysis of the thermoreceptive pit membrane of the western diamondback rattlesnake crotalus atrox. | rattlesnakes detect their prey's temperature by means of a cavern-like structure, the pit organ. the sensory component of this organ lies within a thin membrane called the pit membrane. proteome analysis conducted on this neurosensory tissue revealed only a relatively small number of proteins, thereby depicting its high degree of specialization. in addition to containing blood serum and structural proteins, the proteome of this membrane appears to be strikingly similar to that of isolated rattle ... | 2003 | 12548637 |
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