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1

Late embryos and bony skull development in Bothropoides jararaca (Serpentes, Viperidae).  

PubMed

In recent years, developmental anatomy received increasing interest as a potential new source for phylogenetic research. For skeletal development, studies mainly rely on the first appearance of ossification centers. However, informative events occur during the whole course of skeletogenesis; interactions between external and internal development occur and morphometric changes take place - all of which present potential sources for phylogenetic analyses. Therefore, the Standard Event System (SES) was used to traceably describe the external development of the snake species Bothropoides jararaca and external measurements were analyzed. We then applied micro-computed tomography (?CT), clearing and double-staining, and 2D and 3D morphometric methods to describe, illustrate, and analyze the development of the head in great detail. We found a 3D flattening of the skull during ontogeny, a pattern that is not reflected in external development. This may be explained by a different relationship of skeletogenesis and external characters to the developing jaw musculature or simply by the different type of data. Clearing and double-staining and ?CT-scanning revealed a broadly similar sequence in the onset of ossification. Minute differences may be due to the treatment of embryos. Bones of the dermatocranium are among the first to ossify and the development of the calcified endolymph may reflect its function as a calcium source during development. The value of phylogenetic observations using the sequence of first ossifications is critically discussed. The related heterochronic changes are interpreted to contribute at least to the very first phase of divagating skull formation among taxa. PMID:23348050

Polachowski, Katja M; Werneburg, Ingmar

2013-01-22

2

Inhibition of hemorrhagic and edematogenic activities of snake venoms by a broad-spectrum protease inhibitor, murinoglobulin; the effect on venoms from five different genera in Viperidae family  

Microsoft Academic Search

In order to obtain basic data on the effect of broad-spectrum protease inhibitor against local symptoms of Viperidae snake envenomation, inhibitory capacity of rat murinoglobulin on local hemorrhagic and edematogenic activities of venoms from Crotalus atrox, Bothrops jararaca, Lachesis muta muta, Trimeresurus flavoviridis and Echis carinatus sochureki were examined. Murinoglobulin, pre-incubated with the crude venoms at 37 °C for 15

Wilker Ribeiro Filho; Masahiko Sugiki; Etsuo Yoshida; Masugi Maruyama

2003-01-01

3

Healing rituals and sacred serpents.  

PubMed

Votive tablets found during the excavation of shrines of the Graeco-Roman god of medicine (Asklepios or Aesculapius) associate the healing of superficial lesions with contact with the oral cavity of non-poisonous serpents. We suggest that this may have been the empirical exploitation of the healing properties of salivary growth factors. By immunohistochemistry and immunoblotting we demonstrate the expression of the epidermal growth factor and its receptor in the oral, upper digestive, and salivary epithelia of Elaphe quatuorlineata, a species probably used in healing rituals. PMID:1353146

Angeletti, L R; Agrimi, U; Curia, C; French, D; Mariani-Costantini, R

1992-07-25

4

[Biological and immunological characteristics of the poison of Bothrops cotiara (Serpentes: Viperidae)].  

PubMed

Bothrops cotiara is a venomous snake sporadically found in the province of Misiones in Argentina, South of Brazil and Paraguay. Data on the clinics of the envenomation produced by its bite and on its venom are scarce. There is no information on the neutralizing capacity of the antivenoms available. In this study, the lethal potency, hemorrhagic, necrotizing, coagulant and thrombin-like, defibrinogenating, indirect hemolytic and fibrinolytic activities of the venom of B. cotiara specimens from the province of Misiones were determined. The toxic activities were within the range of those described for the other Bothrops species from Argentina, and the electrophoretic and chromatographic studies showed similarities with those described for the other bothropic venoms. The immunochemical reactivity of six South American anti Viper antivenoms (ELISA) have a strong reactivity with all the antivenoms studied. The neutralizing capacity of three of these therapeutic antivenoms against the lethal potency and hemorrhagic, necrotizing, coagulant, thrombin-like and hemolytic activities showed a very close neutralizing capacity. Our data strongly suggest that the antivenoms for therapeutic use available in this area of South America are useful to neutralize the toxic and enzymatic activities of the venom of this uncommon specie of Bothrops. PMID:18491630

de Roodt, Adolfo Rafael; Estévez, Judith; Dolab, Jorge Adrián; Manzanelli, Marcelo Víctor; Piñeiro, Nicolás; Paniagua, Jorge Francisco; Vogt, Alejandro Urs

2006-09-01

5

Tracing an invasion: landbridges, refugia, and the phylogeography of the Neotropical rattlesnake (Serpentes: Viperidae: Crotalus durissus).  

PubMed

Abstract Pleistocene fragmentation of the Amazonian rainforest has been hypothesized to be a major cause of Neotropical speciation and diversity. However, the role and even the reality of Pleistocene forest refugia have attracted much scepticism. In Amazonia, previous phylogeographical studies have focused mostly on organisms found in the forests themselves, and generally found speciation events to have predated the Pleistocene. However, molecular studies of open-formation taxa found both north and south of the Amazonian forests, probably because of vicariance resulting from expansion of the rainforests, may provide novel insights into the age of continuous forest cover across the Amazon basin. Here, we analyse three mitochondrial genes to infer the phylogeography of one such trans-Amazonian vicariant, the Neotropical rattlesnake (Crotalus durissus), which occupies primarily seasonal formations from Mexico to Argentina, but avoids the rainforests of Central and tropical South America. The phylogeographical pattern is consistent with gradual dispersal along the Central American Isthmus, followed by more rapid dispersal into and across South America after the uplift of the Isthmus of Panama. Low sequence divergence between populations from north and south of the Amazon rainforest is consistent with mid-Pleistocene divergence, approximately 1.1 million years ago (Ma). This suggests that the Amazonian rainforests must have become fragmented or at least shrunk considerably during that period, lending support to the Pleistocene refugia theory as an important cause of distribution patterns, if not necessarily speciation, in Amazonian forest organisms. These results highlight the potential of nonforest species to contribute to an understanding of the history of the Amazonian rainforests themselves. PMID:15773938

Wüster, Wolfgang; Ferguson, Julia E; Quijada-Mascareñas, J Adrian; Pook, Catharine E; Salomão, Maria da Graça; Thorpe, Roger S

2005-04-01

6

Karyotypic Studies of two Species of South American Snakes (Boa constrictor amarali and Bothrops jararaca)  

Microsoft Academic Search

Karyotypic studies have been made of two species of South American snakes, Boa constrictor amarali and Bothrops jararaca. Both have 36 chromosomes; 16 macrochromosomes and 20 microchromosomes. While no morphological difference is discernible between the mitotic chromosome complements of the male and the female Boa constrictor amarali, a heteromorphic pair is evident in the female jararaca, in which the subterminal

W. Beçak; M. L. Beçak; H. R. S. Nazareth

1962-01-01

7

Isolation of Bothrops jararaca Snake Antithrombin from the Supernatant of Fibrinogen Purification  

PubMed Central

A novel method of antithrombin (AT) purification from Bothrops jararaca snake plasma was developed to obtain this protein using a waste supernatant from B. jararaca fibrinogen purification. The AT purification was achieved by affinity chromatography on HiTrap Heparin HP. The results showed an efficient purification process yielding pure AT (purity 65-fold and specific activity 368.91). In conclusion, we showed a feasible purification method of AT from B. jararaca plasma using a discarded material. This feature is important, considering the limitation of material, such as snake plasma, and could also be useful to obtain pure plasma proteins from other animals, including human plasma.

Morais-Zani, K.; Tanaka, A. S.; Tanaka-Azevedo, A. M.

2009-01-01

8

Hypericum brasiliense plant extract neutralizes some biological effects of Bothrops jararaca snake venom  

PubMed Central

Alternative treatments for snake bite are currently being extensively studied, and plant metabolites are considered good candidates for such purpose. Here, the ability of a crude ethanolic extract of Hypericum brasiliense plant in neutralizing Bothrops jararaca snake venom was investigated by in vitro (coagulation, hemolysis or proteolysis) and in vivo (hemorrhage, lethality and edema) biological assays. We describe for the first time the ability of H. brasiliense extracts to inhibit some pharmacological effects of a Brazilian snake venom. Inhibitory assays were performed by incubating B. jararaca venom with H. brasiliense extracts for 30min at room temperature before the assays were performed. The results showed that H. brasiliense extracts impaired lethality, edema, hemorrhage, hemolysis, proteolysis as well as fibrinogen or plasma clotting induced by B. jararaca venom. This indicates that H. brasiliense extracts can provide promising agents to treat B. jararaca envenomation.

Assafim, Mariane; de Coriolano, Eduardo Coriolano; Benedito, Sergio Eufrazio; Fernandes, Caio Pinho; Lobo, Jonathas Felipe Revoredo; Sanchez, Eladio Florez; Rocha, Leandro Machado; Fuly, Andre Lopes

2011-01-01

9

Burnup calculation methodology in the serpent 2 Monte Carlo code  

SciTech Connect

This paper presents two topics related to the burnup calculation capabilities in the Serpent 2 Monte Carlo code: advanced time-integration methods and improved memory management, accomplished by the use of different optimization modes. The development of the introduced methods is an important part of re-writing the Serpent source code, carried out for the purpose of extending the burnup calculation capabilities from 2D assembly-level calculations to large 3D reactor-scale problems. The progress is demonstrated by repeating a PWR test case, originally carried out in 2009 for the validation of the newly-implemented burnup calculation routines in Serpent 1. (authors)

Leppaenen, J. [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland); Isotalo, A. [Aalto Univ., Dept. of Applied Physics, P.O.Box 14100, FI-00076 AALTO (Finland)

2012-07-01

10

Jararhagin, a hemorrhagic snake venom metalloproteinase from Bothrops jararaca.  

PubMed

Jararhagin is a metalloproteinase isolated from Bothrops jararaca snake venom, which has been extensively studied. These studies showed its involvement on most of the systemic and local damaging effects of snakebite envenomings. In this review we comment on the major targets of jararhagin as the vascular endothelium, platelets and coagulation factors and also its action on other cell systems as inflammatory cells and their mediators, cancer and cell signaling. The mechanisms of jararhagin action are discussed together with structural features essential for the expression of its biological activities. The studies reviewed here denote jararhagin as a prototype for studies of snake venom metalloproteinases, bringing new insights into cellular-matrix interactions and adding for the improvement of snakebite treatment. PMID:22534074

Moura-da-Silva, Ana M; Baldo, Cristiani

2012-04-14

11

The golden lancehead Bothrops insularis (Serpentes: Viperidae) relies on two seasonally plentiful bird species visiting its island habitat  

Microsoft Academic Search

Adult individuals of the island pitviper Bothrops insularis have a diet based on birds. We analysed bird species recorded in the gut of this snake and found that it relies on two out of 41 bird species recorded on the island. When present, these two prey species were among the most abundant passerine birds on the island. A few other

Otavio A. V. Marques; Marcio Martins; Pedro F. Develey; Arthur Macarrão; Ivan Sazima

2012-01-01

12

Morphological, morphometric, and molecular characterization of Hepatozoon spp. (Apicomplexa, Hepatozoidae) from naturally infected Caudisona durissa terrifica (Serpentes, Viperidae).  

PubMed

Hepatozoon spp. are the most frequent intracellular protozoa in snakes. Considering the variety of parasites infecting specimens of Caudisona durissa terrifica and the divergent data in literature where only two species, Hepatozoon romani and Hepatozoon capsulata, are described, the aim of this study was to morphologically, morphometrically, and molecularly characterize Hepatozoon spp. from some naturally infected specimens of C. durissa terrifica, and observe changes caused by these protozoa in parasitized erythrocytes. Four snakes were examined. Two of them had two morphological distinct gamonts, while the other two had only one type of gamont. The six distinct gamonts were provisionally named gamonts A, B, C, D, E, and F. Statistical analysis, however, confirmed the existence of only four parasite populations, those which were capable of inducing significant alterations in determined red blood cells variables. Attempts to infect Aedes aegypti and Culex quinquefasciatus mosquitoes were done for each snake specimen. Some mosquitoes became infected and oocysts were recovered and measured. The detection of Hepatozoon DNA was obtained with success but the molecular characterization was unable to differentiate species of the samples, with respect to the fragment studied. PMID:21922238

Moço, Tatiana Cristina; da Silva, Reinaldo José; Madeira, Newton Goulart; Dos Santos Paduan, Karina; Rubini, Adriano Stefani; Leal, Denise Dutra Menezes; O'Dwyer, Lucia Helena

2011-09-16

13

When continents collide: phylogeny, historical biogeography and systematics of the medically important viper genus Echis (Squamata: Serpentes: Viperidae).  

PubMed

We analyze the phylogeny of the medically important and taxonomically unresolved viper genus Echis using four mitochondrial gene fragments. The results show that the populations of the genus fall into four main clades: the Echis carinatus, E. coloratus, E. ocellatus and E. pyramidum groups. The E. pyramidum and E. coloratus groups are sister taxa but the interrelationships of this clade and the E. ocellatus and E. carinatus groups are unresolved. The initial divergence of the genus appears to coincide with the collision between Afro-Arabia and Eurasia, and that between the E. coloratus and E. pyramidum clades appears to be associated with the opening of the Red Sea. Later land connections between Africa and Arabia may have contributed to shaping the distribution of the E. pyramidum complex. The present distribution of E. carinatus may be the result of range expansion from southern India. Taxonomically, our results provide molecular evidence for the validity of Echis omanensis, E. khosatzkii, E. borkini and E. jogeri, for the presence of unsuspected genetic diversity within the E. pyramidum complex in eastern Africa, and for the conspecificity of E. carinatus and E. multisquamatus. The status of E. leucogaster remains to be confirmed. PMID:19666129

Pook, Catharine E; Joger, Ulrich; Stümpel, Nikolaus; Wüster, Wolfgang

2009-08-08

14

Antigenic, microbicidal and antiparasitic properties of an l-amino acid oxidase isolated from Bothrops jararaca snake venom  

Microsoft Academic Search

Venoms from the bee Apis mellifera, the caterpillar Lonomia achelous, the spiders Lycosa sp. and Phoneutria nigriventer, the scorpions Tityus bahiensis and Tityus serrulatus, and the snakes Bothrops alternatus, Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Bothrops neuwiedi, Crotalus durissus terrificus, and Lachesis muta were assayed (800?g\\/mL) for activity against Staphylococcus aureus. Venoms from B. jararaca and B. jararacussu showed the

P. Ciscotto; R. A. Machado de Avila; E. A. F. Coelho; J. Oliveira; C. G. Diniz; L. M. Farías; M. A. R. de Carvalho; W. S. Maria; E. F. Sanchez; A. Borges; C. Chávez-Olórtegui

2009-01-01

15

Neutralization of a snake venom hemorrhagic metalloproteinase prevents coagulopathy after subcutaneous injection of Bothrops jararaca venom in rats  

Microsoft Academic Search

Coagulopathy is one of the major complications following envenomations by crotalid and viperid snakes. The present study was undertaken to examine the effect of a hemorrhagic metalloproteinase in Bothrops jararaca venom, jararafibrase I (JF I), on the development of coagulopathy using rat snakebite model. Coagulation parameters were monitored after subcutaneous injection of B. jararaca crude venom, JF I-neutralized venom and

Keita Anai; Masahiko Sugiki; Etsuo Yoshida; Masugi Maruyama

2002-01-01

16

Appraisal of Antiophidic Potential of Marine Sponges against Bothrops jararaca and Lachesis muta Venom.  

PubMed

Snakebites are a health problem in many countries due to the high incidence of such accidents. Antivenom treatment has regularly been used for more than a century, however, this does not neutralize tissue damage and may even increase the severity and morbidity of accidents. Thus, it has been relevant to search for new strategies to improve antiserum therapy, and a variety of molecules from natural sources with antiophidian properties have been reported. In this paper, we analyzed the ability of ten extracts from marine sponges (Amphimedon viridis, Aplysina fulva, Chondrosia collectrix, Desmapsamma anchorata, Dysidea etheria, Hymeniacidon heliophila, Mycale angulosa, Petromica citrina, Polymastia janeirensis, and Tedania ignis) to inhibit the effects caused by Bothrops jararaca and Lachesis muta venom. All sponge extracts inhibited proteolysis and hemolysis induced by both snake venoms, except H. heliophila, which failed to inhibit any biological activity. P. citrina inhibited lethality, hemorrhage, plasma clotting, and hemolysis induced by B. jararaca or L. muta. Moreover, other sponges inhibited hemorrhage induced only by B. jararaca. We conclude that Brazilian sponges may be a useful aid in the treatment of snakebites caused by L. muta and B. jararaca and therefore have potential for the discovery of molecules with antiophidian properties. PMID:24141284

Faioli, Camila Nunes; Domingos, Thaisa Francielle Souza; de Oliveira, Eduardo Coriolano; Sanchez, Eládio Flores; Ribeiro, Suzi; Muricy, Guilherme; Fuly, Andre Lopes

2013-10-17

17

Bothrops asper and Bothrops jararaca snake venoms trigger microbicidal functions of peritoneal leukocytes in vivo  

Microsoft Academic Search

Venoms from snakes of the genus Bothrops cause pronounced local effects in the victims. These alterations result not only from the direct toxic action of venom components, but also from the prominent inflammatory reaction associated with these envenomations. In this study we investigated the ability of Bothrops asper (BaV) and Bothrops jararaca (BjV) venoms to induce cellular influx and microbicidal

Stella R Zamuner; José Maria Gutiérrez; Marcelo N Muscará; Simone A Teixeira; Catarina F. P Teixeira

2001-01-01

18

Appraisal of Antiophidic Potential of Marine Sponges against Bothrops jararaca and Lachesis muta Venom  

PubMed Central

Snakebites are a health problem in many countries due to the high incidence of such accidents. Antivenom treatment has regularly been used for more than a century, however, this does not neutralize tissue damage and may even increase the severity and morbidity of accidents. Thus, it has been relevant to search for new strategies to improve antiserum therapy, and a variety of molecules from natural sources with antiophidian properties have been reported. In this paper, we analyzed the ability of ten extracts from marine sponges (Amphimedon viridis, Aplysina fulva, Chondrosia collectrix, Desmapsamma anchorata, Dysidea etheria, Hymeniacidon heliophila, Mycale angulosa, Petromica citrina, Polymastia janeirensis, and Tedania ignis) to inhibit the effects caused by Bothrops jararaca and Lachesis muta venom. All sponge extracts inhibited proteolysis and hemolysis induced by both snake venoms, except H. heliophila, which failed to inhibit any biological activity. P. citrina inhibited lethality, hemorrhage, plasma clotting, and hemolysis induced by B. jararaca or L. muta. Moreover, other sponges inhibited hemorrhage induced only by B. jararaca. We conclude that Brazilian sponges may be a useful aid in the treatment of snakebites caused by L. muta and B. jararaca and therefore have potential for the discovery of molecules with antiophidian properties.

Faioli, Camila Nunes; Domingos, Thaisa Francielle Souza; de Oliveira, Eduardo Coriolano; Sanchez, Eladio Flores; Ribeiro, Suzi; Muricy, Guilherme; Fuly, Andre Lopes

2013-01-01

19

Toxicity and Some Enzymatic Properties and Activities in the Venoms of Crotalidae, Elapidae and Viperidae.  

National Technical Information Service (NTIS)

The i.v. and i.p. toxicities and some enzymatic properties of representative venoms of the families Crotalidae, Elapidae and Viperidae were determined. Differences between the venoms of the three genera in toxicity and enzymatic activity were considerable...

E. B. Ledford J. G. Daly T. A. Billings W. F. Kocholaty

1970-01-01

20

1900 - The Accommodating Serpent and God's Grace in Paradise Lost  

Microsoft Academic Search

Paradise Lost, much more successfully than has been recognized, meets the challenge to make understandable the curse upon the Serpent while navigating tough theological terrain. As Milton was well aware, an inexplicable and special punishment inflicted upon an innocent animal threatens to impugn God’s goodness. The text goes beyond locating accommodated meaning in the curse to depict its pronouncement as

Sarah R. Morrison

2009-01-01

21

A Transcriptomic View of the Proteome Variability of Newborn and Adult Bothrops jararaca Snake Venoms  

PubMed Central

Background Snake bite is a neglected public health problem in communities in rural areas of several countries. Bothrops jararaca causes many snake bites in Brazil and previous studies have demonstrated that the pharmacological activities displayed by its venom undergo a significant ontogenetic shift. Similarly, the venom proteome of B. jararaca exhibits a considerable variation upon neonate to adult transition, which is associated with changes in diet from ectothermic prey in early life to endothermic prey in adulthood. Moreover, it has been shown that the Brazilian commercial antibothropic antivenom, which is produced by immunization with adult venom, is less effective in neutralizing newborn venom effects. On the other hand, venom gland transcripts of newborn snakes are poorly known since all transcriptomic studies have been carried out using mRNA from adult specimens. Methods/Principal Findings Here we analyzed venom gland cDNA libraries of newborn and adult B. jararaca in order to evaluate whether the variability demonstrated for its venom proteome and pharmacological activities was correlated with differences in the structure of toxin transcripts. The analysis revealed that the variability in B. jararaca venom gland transcriptomes is quantitative, as illustrated by the very high content of metalloproteinases in the newborn venom glands. Moreover, the variability is also characterized by the structural diversity of SVMP precursors found in newborn and adult transcriptomes. In the adult transcriptome, however, the content of metalloproteinase precursors considerably diminishes and the number of transcripts of serine proteinases, C-type lectins and bradykinin-potentiating peptides increase. Moreover, the comparison of the content of ESTs encoding toxins in adult male and female venom glands showed some gender-related differences. Conclusions/Significance We demonstrate a substantial shift in toxin transcripts upon snake development and a marked decrease in the metalloproteinase P-III/P-I class ratio which are correlated with changes in the venom proteome complexity and pharmacological activities.

Zelanis, Andre; Andrade-Silva, Debora; Rocha, Marisa M.; Furtado, Maria F.; Serrano, Solange M. T.; Junqueira-de-Azevedo, Inacio L. M.; Ho, Paulo Lee

2012-01-01

22

Alexander, Scipio and Octavian: Serpent-Siring in Macedon and Rome  

Microsoft Academic Search

:The earliest categorical evidence for the myth of Alexander's serpent-siring derives from the Latin tradition of the ages of the Second Triumvirate and the principate of Augustus, who was also attributed with serpent-siring. This obliges us to ask whether the myth may have originated with or for Octavian, the future Augustus. An accumulation of indirect evidence does indeed suggest that

Daniel Ogden

2011-01-01

23

Alexander, Scipio and Octavian: Serpent-Siring in Macedon and Rome  

Microsoft Academic Search

The earliest categorical evidence for the myth of Alexander's serpent-siring derives from the Latin tradition of the ages of the Second Triumvirate and the principate of Augustus, who was also attributed with serpent-siring. This obliges us to ask whether the myth may have originated with or for Octavian, the future Augustus. An accumulation of indirect evidence does indeed suggest that

Daniel Ogden

2011-01-01

24

Feathered Serpent Pyramid Pages: Archaeology of Teotihuacan Mexico  

NSDL National Science Digital Library

For those interested in a look at aboriginal life on the North American continent, this two archaeological site should fit the bill. Feathered Serpent Pyramid Pages, provided by the Archaeological Research Institute of Arizona State University, is a much more detailed, scholarly look at an ancient pyramid at Teotihuacan, Mexico. The site details arts and artifacts of the pyramid. It includes architecture, graves, and offerings.

Sugiyama, Saburo.

1996-01-01

25

Proteomic Analysis of the Ontogenetic Variability in Plasma Composition of Juvenile and Adult Bothrops jararaca Snakes  

PubMed Central

The ontogenetic variability in venom composition of some snake genera, including Bothrops, as well as the biological implications of such variability and the search of new molecules that can neutralize the toxic components of these venoms have been the subject of many studies. Thus, considering the resistance of Bothrops jararaca to the toxic action of its own venom and the ontogenetic variability in venom composition described in this species, a comparative study of the plasma composition of juvenile and adult B. jararaca snakes was performed through a proteomic approach based on 2D electrophoresis and mass spectrometry, which allowed the identification of proteins that might be present at different levels during ontogenetic development. Among the proteins identified by mass spectrometry, antihemorrhagic factor Bj46a was found only in adult plasma. Moreover, two spots identified as phospholipase A2 inhibitors were significantly increased in juvenile plasma, which can be related to the higher catalytic PLA2 activity shown by juvenile venom in comparison to that of adult snakes. This work shows the ontogenetic variability of B. jararaca plasma, and that these changes can be related to the ontogenetic variability described in its venom.

de Morais-Zani, Karen; Grego, Kathleen Fernandes; Tanaka, Aparecida Sadae; Tanaka-Azevedo, Anita Mitico

2013-01-01

26

Morphological study of accessory gland of Bothrops jararaca and its secretory cycle.  

PubMed

The venom gland apparatus of Bothrops jararaca is composed of four distinct parts: main venom gland, primary duct, accessory gland and secondary duct. Despite the numerous studies concerning morphology and venom production and secretion in the main venom gland, there are few studies about the accessory gland and its secretion. We characterized the accessory gland of B. jararaca snake and determined the secretion cycle by morphological analysis using light and transmission electron microscopy. Our data showed that the accessory gland of B. jararaca has a simple secretory epithelium with at least six types of cells in the anterior region: two types of secretory cells, mitochondria-rich cells without secretory vesicles, horizontal cells, dark cells and basal cells, and in the posterior region a simple epithelium with two types of cells: seromucous cells and horizontal cells. Furthermore, the mucous secretory cells of the accessory gland show a delayed and massive exocytosis that occurs four days after the extraction of venom. Morphological analysis at different steps after venom extraction showed that the accessory gland has a long cycle of production and secretion, which is not synchronous with the main venom gland secretory cycle. PMID:22227156

Sakai, Fernanda; Carneiro, Sylvia M; Yamanouye, Norma

2011-12-30

27

Individual Variability in the Venom Proteome of Juvenile Bothrops jararaca Specimens.  

PubMed

Snake venom proteomes/peptidomes are highly complex and subject to ontogenetic changes. Individual variation in the venom proteome of juvenile snakes is poorly known. We report the proteomic analysis of venoms from 21 juvenile specimens of Bothrops jararaca of different geographical origins and correlate it with the evaluation of important venom features. Individual venoms showed similar caseinolytic activities; however, their amidolytic activities were significantly different. Rather intriguingly, plasma coagulant activity showed remarkable variability among the venoms but not the prothrombin-activating activity. LC-MS analysis showed significant differences between venoms; however, an interesting finding was the ubiquitous presence of the tripeptide ZKW, an endogenous inhibitor of metalloproteinases. Electrophoretic profiles of proteins submitted to reduction showed significant variability in total proteins, glycoproteins, and in the subproteomes of proteinases. Moreover, identification of differential bands revealed variation in most B. jararaca toxin classes. Profiles of venoms analyzed under nonreducing conditions showed less individual variability and identification of proteins in a conserved band revealed the presence of metalloproteinases and l-amino acid oxidase as common components of these venoms. Taken together, our findings suggest that individual venom proteome variability in B. jararaca exists from a very early animal age and is not a result of ontogenetic and diet changes. PMID:23998483

Dias, Gabriela S; Kitano, Eduardo S; Pagotto, Ana H; Sant'anna, Sávio S; Rocha, Marisa M T; Zelanis, André; Serrano, Solange M T

2013-09-18

28

Ancient scientific basis of the "great serpent" from historical evidence.  

PubMed

Zoological data and a growing mythology contributed to ancient Western knowledge about large serpents. Yet little modern attention has been paid to the sources, transmission, and receipt in the early Middle Ages of the ancients' information concerning "dragons" and "sea serpents." Real animals--primarily pythons and whales--lie behind the ancient stories. Other animals, conflations of different animals, simple misunderstandings, and willful exaggerations are found to account for the fanciful embellishments, but primitive myths played no significant role in this process during classical times. The expedition of Alexander the Great into India (327-325 B.C.) and the Bagradas River incident in North Africa (256 B.C.) had enormous repercussions on the development of serpent lore. Credible evidence is found for the presence of ancient populations of pythons living along the North African coast west of Egypt and along the coast of the Arabian Sea between the Indus River and the Strait of Hormuz--places where they no longer exist today. The maximum sizes of ancient pythons may have been greater than those of today's specimens. PMID:15490966

Stothers, Richard B

2004-06-01

29

Interpolations of nuclide-specific scattering kernels generated with Serpent  

SciTech Connect

The neutron group-to-group scattering cross section is an essential input parameter for any multi-energy group physics model. However, if the analyst prefers to use Monte Carlo transport to generate group constants this data is difficult to obtain for a single species of a material. Here, the Monte Carlo code Serpent was modified to return the group transfer probabilities on a per-nuclide basis. This ability is demonstrated in conjunction with an essential physics reactor model where cross section perturbations are used to dynamically generate reactor state dependent group constants via interpolation from pre-computed libraries. The modified version of Serpent was therefore verified with three interpolation cases designed to test the resilience of the interpolation scheme to changes in intra-group fluxes. For most species, interpolation resulted in errors of less than 5% of transport-computed values. For important scatterers, such as {sup 1}H, errors less than 2% were observed. For nuclides with high errors ( > 10%), the scattering channel typically only had a small probability of occurring. (authors)

Scopatz, A.; Schneider, E. [Univ. of Texas at Austin, 1 Univ. Station, C2200, Austin, TX 78712 (United States)

2012-07-01

30

Antigenic, microbicidal and antiparasitic properties of an l-amino acid oxidase isolated from Bothrops jararaca snake venom.  

PubMed

Venoms from the bee Apis mellifera, the caterpillar Lonomia achelous, the spiders Lycosa sp. and Phoneutria nigriventer, the scorpions Tityus bahiensis and Tityus serrulatus, and the snakes Bothrops alternatus, Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Bothrops neuwiedi, Crotalus durissus terrificus, and Lachesis muta were assayed (800mug/mL) for activity against Staphylococcus aureus. Venoms from B. jararaca and B. jararacussu showed the highest S. aureus growth inhibition and also against other Gram-positive and Gram-negative bacteria. To characterize the microbicidal component(s) produced by B. jararaca, venom was fractionated through gel exclusion chromatography. The high molecular weight, anti-S. aureus P1 fraction was further resolved by anion exchange chromatography through Mono Q columns using a 0-0.5M NaCl gradient. Bactericidal Mono Q fractions P5 and P6 showed significant LAAO activity using l-leucine as substrate. These fractions were pooled and subjected to Heparin affinity chromatography, which rendered a single LAAO activity peak. The anti-S. aureus activity was abolished by catalase, suggesting that the effect is dependent on H(2)O(2) production. SDS-PAGE of isolated LAAO indicated the presence of three isoforms since deglycosylation with a recombinant N-glycanase rendered a single 38.2 kDa component. B. jararaca LAAO specific activity was 142.7 U/mg, based on the oxidation of l-leucine. The correlation between in vivo neutralization of lethal toxicity (ED(50)) and levels of horse therapeutic antibodies anti-LAAO measured by ELISA was investigated to predict the potency of Brazilian antibothropic antivenoms. Six horses were hyperimmunized with Bothrops venoms (50% from B. jararaca and 12.5% each from B. alternatus, B. jararacussu, B. neuwiedii and B. moojeni). To set up an indirect ELISA, B. jararaca LAAO and crude venom were used as antigens. Correlation coefficients (r) between ED(50) and ELISA antibody titers against B. jararaca venom and LAAO were 0.846 (p<0.001) and 0.747 (p<0.001), respectively. The hemolytic and leishmanicidal (anti-Leishmania amazonensis) activity of LAAO was also determined. PMID:19101583

Ciscotto, P; Machado de Avila, R A; Coelho, E A F; Oliveira, J; Diniz, C G; Farías, L M; de Carvalho, M A R; Maria, W S; Sanchez, E F; Borges, A; Chávez-Olórtegui, C

2008-12-11

31

NPP-BJ, a nucleotide pyrophosphatase/phosphodiesterase from Bothrops jararaca snake venom, inhibits platelet aggregation.  

PubMed

Enzymes of the pyrophosphatase/phosphodiesterase family have multiple roles in extracellular nucleotide metabolism and in the regulation of nucleotide-based intercellular signaling. Snake venoms contain enzymes that hydrolyze nucleic acids and nucleotides, but their function is poorly understood. Here we describe for the first time the isolation and functional characterization of a soluble phosphodiesterase from Bothrops jararaca venom, which shows amino acid sequence similarity to mammalian nucleotide pyrophosphatase/phosphodiesterase 3 (NPP3), and inhibits ADP-induced platelet aggregation. The enzyme, named NPP-BJ, showed an apparent molecular mass of 228 kDa by size exclusion chromatography. NPP-BJ exhibited nuclease activity as well as pyrophosphatase and phosphatase activities, preferentially hydrolyzing nucleoside 5'-triphosphates over nucleoside 5'-diphosphates, but was not active upon nucleoside 5'-monophosphates. Depending on the substrate used, dithiothreitol and EDTA differently inhibited the catalytic activity of NPP-BJ. Platelet aggregation induced by ADP was also abrogated by NPP-BJ, whereas thrombin-induced platelet aggregation was only slightly attenuated. However, polyclonal antibodies raised against NPP-BJ could not abolish the lethal activity of B. jararaca venom. Altogether, these results show that NPP-BJ has a minor contribution to the lethal activity of this venom, but interferes with mechanisms of ADP-induced platelet aggregation. PMID:19481561

Santoro, Marcelo L; Vaquero, Tais S; Leme, Adriana F Paes; Serrano, Solange M T

2009-05-28

32

Local haemorrhage induced by Bothrops jararaca venom: relationship to neurogenic inflammation.  

PubMed

We investigated morphological alterations induced by s.c. injection of 2.5 microg of Bothrops jararaca venom in rats. Intense disorganisation of collagen fibres was observed 1 min after the venom injection, particularly at regions near vessels and nerves. Mast cells were degranulated, and erythrocytes were seen leaving venules throughout the endothelial junctions. At this time, damaged endothelial cells were not observed. In rats envenomed as above, but immediately after cardiorespiratory failure induced by deep ether anaesthesia, alterations in the connective tissue structures, as previously described, were not observed. The mediation of this haemorrhage was investigated by injecting the venom into the foot pad of mice and compared to the mediation of oedema. Local haemorrhage was significantly reduced in mice pre-treated with capsaicin or guanethidine or submitted to a surgical section of sciatic and saphenous nerves. In these animals, oedema was not affected. Groups treated with methysergide or morphine showed both haemorrhage and oedema significantly reduced. Indomethacin or dexamethasone pre-treatments significantly reduced the oedema, but not the haemorrhage. Moreover, in animals treated with promethazine or mepyramine, oedema and haemorrhage were not affected. These data suggest that local haemorrhage induced by Bothrops jararaca venom is partially controlled by serotonin and neurohumoral mediators. Furthermore, results indicate that haemorrhage and oedema are mediated by different pharmacological systems. PMID:10958383

Gonçalves, L R; Mariano, M

2000-01-01

33

Anti-hemorrhagic activity of four Brazilian vegetable species against Bothrops jararaca venom.  

PubMed

Around 20,000 snakebites are reported annually in Brazil and 90% of them are inflicted by species of the genus Bothrops. Intravenous administration of antibothropic antivenom neutralizes the systemic actions, but it is of little effect on the reversal of local symptoms and often induces adverse reactions, a context that drives the search for complementary treatments for snakebite accidents. Vegetable extracts with a range of antiophidian activities constitute an excellent alternative. In this study, we investigated the anti-hemorrhagic effects of Mouriri pusa Gardn. (Melastomataceae), Byrsonima crassa Niedenzu (Malpighiaceae), Davilla elliptica St. Hill. (Dilleniaceae) and Strychnos pseudoquina St. Hil. (Loganiaceae) against Bothrops jararaca venom. The methanolic extracts from M. pusa (leaves), B. crassa (leaves) and D. elliptica (leaves) showed total neutralization capacity against local hemorrhages. The amenthoflavone and quercetin fractions from B. crassa and the flavonoids fractions (quercetin and myricetin) from M. pusa and D. elliptica also showed total neutralization capacity. We conclude that flavonoids derived from myricetin, quercetin and amenthoflavone play an important role in the anti-hemorrhagic potential of these Brazilian vegetables species against B. jararaca venom. PMID:19305361

Nishijima, Catarine Massucato Nishijima; Rodrigues, Clenilson Martins; Silva, Marcelo Aparecido; Lopes-Ferreira, Mônica; Vilegas, Wagner; Hiruma-Lima, Clélia Akiko

2009-03-09

34

Winter proWle of plasma sex steroid levels in free-living male western diamond-backed rattlesnakes, Crotalus atrox (Serpentes: Viperidae)  

Microsoft Academic Search

Recent Weld studies on the reproductive ecology of western diamond-backed rattlesnakes (Crotalus atrox) from populations in southern Ari- zona showed signiWcant diVerences in the concentration of plasma sex steroids (testosterone, T; 5-dihydrotestosterone, DHT; and 17-estra- diol, 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,

Gordon W. Schuett; Roger A. Repp; Emily N. Taylor; Dale F. DeNardo; Ryan L. Earley; Edward A. Van Kirk; William J. Murdoch

35

Chromatin supraorganization, DNA fragmentation, and cell death in erythrocytes of the rattlesnake, Crotalus durissus terrificus (Serpentes, Viperidae), infected with the protozoan, Hepatozoon spp. (Apicomplexa, Hepatozoidae)  

Microsoft Academic Search

Forms of the protozoan of the Hepatozoon genus are detected free in the circulation and also within some of the erythrocytes of infected snakes. In healthy snakes, DNA fragmentation and cell death usually affect a few circulating erythrocytes in agreement with the long life span expected for these cells. In the present study we investigated whether infection by Hepatozoon spp.

Maristela Miyamoto; Maria Luiza S. Mello

2007-01-01

36

Lachesis muta (Viperidae) cDNAs Reveal Diverging Pit Viper Molecules and Scaffolds Typical of Cobra (Elapidae) Venoms: Implications for Snake Toxin Repertoire Evolution  

Microsoft Academic Search

Efforts to describe toxins from the two major families of venomous snakes (Viperidae and Elapidae) usually reveal proteins belonging to few structural types, particular of each family. Here we carried on an effort to determine uncommon cDNAs that represent possible new toxins from Lachesis muta (Viperidae). In addition to nine classes of typical toxins, atypical molecules never observed in the

Inácio L. M. Junqueira-de-Azevedo; Ana T. C. Ching; Eneas Carvalho; Fernanda Faria; Milton Y. Nishiyama Jr; Paulo L. Ho; Marcelo R. V. Diniz

2006-01-01

37

Comparative Analysis of Viperidae Venoms Antibacterial Profile: a Short Communication for Proteomics  

PubMed Central

Bacterial infections involving multidrug-resistant strains are one of the ten leading causes of death and an important health problem in need for new antibacterial sources and agents. Herein, we tested and compared four snake venoms (Agkistrodon rhodostoma, Bothrops jararaca, B. atrox and Lachesis muta) against 10 Gram-positive and Gram-negative drug-resistant clinical bacteria strains to identify them as new sources of potential antibacterial molecules. Our data revealed that, as efficient as some antibiotics currently on the market (minimal inhibitory concentration (MIC) = 1–32 ?g mL?1), A. rhodostoma and B. atrox venoms were active against Staphylococcus epidermidis and Enterococcus faecalis (MIC = 4.5 ?g mL?1), while B. jararaca inhibited S. aureus growth (MIC = 13 ?g ml?1). As genomic and proteomic technologies are improving and developing rapidly, our results suggested that A. rhodostoma, B. atrox and B. jararaca venoms and glands are feasible sources for searching antimicrobial prototypes for future design new antibiotics against drug-resistant clinical bacteria. They also point to an additional perspective to fully identify the pharmacological potential of these venoms by using different techniques.

Ferreira, Bruno L.; Santos, Dilvani O.; dos Santos, Andre Luis; Rodrigues, Carlos R.; de Freitas, Cicero C.; Cabral, Lucio M.; Castro, Helena C.

2011-01-01

38

[Edema and myonecrosis induced by Bothrops jararaca venom of Argentina in mice].  

PubMed

Myonecrotic and oedema-inducing activities of Bothrops jararaca of Argentina were studied. For oedema-inducing activity 0.05 ml of different solutions of venom in 0.9% NaCl were injected in mice. The dose of 0.86 micrograms/20 g mouse induced an oedema of 30% respect the other member in one hour. The myonecrotic effects were studied injecting mice gastrocnemius muscle with 70 micrograms of venom in 0.1 ml of 0.9% NaCl, which were sacrificed in different time. The inoculation area was obtained for hystophatological process. Animal sacrificed 30 minutes after the inoculation showed oedema, hemorrhage and inflammatory infiltrate. Those sacrificed in one and three hours after the inoculation also had got necrosis. PMID:9222388

Acosta de Pérez, O; Teibler, P; Koscinczuk, P; Sánchez Negrette, M; Trulls, H; Maruñak, S

1996-01-01

39

Role of kinins and nitric oxide on the rabbit arthritis induced by Bothrops jararaca venom.  

PubMed

The effects of the nitric oxide synthase inhibitor N(omega)Nitro-L-arginine-methyl ester (L-NAME) and of the bradykinin B(2) receptor antagonist HOE 140 were evaluated in the inflammatory reaction induced by Bothrops jararaca venom (BjV) in New Zealand White rabbits. Arthritis was induced by injecting 0.5 ml of a sterile solution of BjV (1-64 microg/ml) into the knee intraarticular cavity. The contralateral joint was injected with bovine serum albumin (BSA) diluted in sterile saline. At selected times thereafter (4, 24 and 48 h), the vascular permeability and the leukocyte influx in both the synovial fluid and synovium were evaluated. BjV caused a dose-dependent increase in both leukocyte influx and protein extravasation which reached a maximal response at 16 microg. Bothrops jararaca venom also induced the increase in the leukocyte accumulation in the synovium and in the concentration of both NO(2)/NO(3) in the synovial fluid. Chronic administration of L-NAME (20 mg/kg/day in the drinking water for 2 weeks) markedly reduced the leukocyte accumulation (90%), protein leakage (44%), and NO(2)/NO(3) (50%) levels in the synovial fluid, measured at the 4th h. Hoe 140, given i.v. (0.3 mg/kg, 30 min before) also reduced leukocyte accumulation (75%), protein leakage (48%), and NO(2)/NO(3) (79%) levels in the synovial fluid, measured at the 4th h. Similar results were obtained with acute administration of L-NAME (30 mg/kg, i.v., 30 min before). These results indicate that arthritis induced by BjV is triggered by kinin formation and that the increase in both vascular permeability and leukocyte accumulation is modulated by NO release. PMID:10775754

Guzzo, M L; Farsky, S H; De Nucci, G; Antunes, E; Silva, M A; Mello, S B

2000-11-01

40

Increments in serum cytokine and nitric oxide levels in mice injected with Bothrops asper and Bothrops jararaca snake venoms  

Microsoft Academic Search

Changes in serum levels of several cytokines and nitric oxide were studied in BALB\\/c mice injected intraperitoneally with one median lethal dose (ld50) of the venoms of Bothrops asper and Bothrops jararaca, two of the medically most important poisonous snakes of Latin America. Despite differences observed in the time-course of cytokine increments and in serum cytokine levels, both venoms induced

Vera L. Petricevich; Catarina F. P. Teixeira; Denise V. Tambourgi; José Mar??a Gutiérrez

2000-01-01

41

Isolation and biochemical characterization of a fibrinolytic proteinase from Bothrops leucurus (white-tailed jararaca) snake venom  

Microsoft Academic Search

In investigations aimed at characterizing snake venom clot-dissolving enzymes, we have purified a fibrinolytic proteinase from the venom of Bothrops leucurus (white-tailed jararaca). The proteinase was purified to homogeneity by a combination of molecular sieve chromatography on Sephacryl S-200 and ion-exchange chromatography on CM Sepharose. The enzyme called leucurolysin-a (leuc-a), is a 23 kDa metalloendopeptidase since it is inhibited by EDTA.

C. A. Bello; A. L. N. Hermogenes; A. Magalhaes; S. S. Veiga; L. H. Gremski; M. Richardson; Eladio F. Sanchez

2006-01-01

42

Reproductive biology and diet of Liophis poecilogyrus poecilogyrus (Serpentes, Colubridae) from southeastern Brazil  

Microsoft Academic Search

Reproductive biology and diet of Liophis poecilogyrus poecilogyrus (Serpentes, Colubridae) from southeastern Brazil. We describe the reproductive pattern and the diet of Liophis poecilogyrus poecilogyrus based on examination of museum specimens. The snake has an aseasonal reproductive pattern, suggesting multiple clutches during a year. Females are larger than males when sexual maturity is reached. Clutch size ranges from six to

Roberta R. Pinto; Ronaldo Fernandes

2004-01-01

43

Radionuclide uptake by beaver and ruffed grouse in the Serpent River basin.  

National Technical Information Service (NTIS)

Radionuclide levels were measured in tissues, gut contents, and diet items of adult beaver and ruffed grouse from the Serpent River drainage basin (which contains the city of Elliot Lake) and control sites in Ontario, and in beaver and muskrat fetuses fro...

F. V. Clulow

1988-01-01

44

A survey of the southernmost representatives of the tricolor species group, genus Phalotris (Serpentes, Colubridae)  

Microsoft Academic Search

A survey of the southernmost representatives of the tricolor species group, genus Phalotris (Serpentes, Colubridae). Colubrid snakes of the South American genus Phalotris are difficult to detect because of their secretive habits, and thus they are poorly represented in collections. The species Phalotris cuyanus and P. tricolor, the southernmost representatives of the tricolor species group, were studied to determine the

Gerardo C. Leynaud; Mario R. Cabrera; Paola Carrasco

2005-01-01

45

Hypothalamic activity during altered salt and water balance in the snake Bothrops jararaca.  

PubMed

The effects of water and salt overload on the activities of the supraoptic and paraventricular nuclei and the adjacent periventricular zone of the hypothalamus of the snake Bothrops jararaca were investigated by measurements of Fos-like immunoreactivity (Fos-ir). Both water and salt overload resulted in changes in body mass, plasma osmolality, and plasma concentrations of sodium, potassium, and chloride. Hyper-osmolality increased Fos immunoreactivity in the rostral supraoptic nucleus (SON), the paraventricular nucleus (PVN), and adjacent periventricular areas. Both hyper- and hypo-osmolality increased Fos immunoreactivity in the intermediate SON, but not in other areas of the hypothalamus. Immunostaining was abundant in cerebrospinal fluid (CSF)-contacting tanycyte-like cells in the ependymal layer of the third ventricle. These data highlight some features of regional distribution of Fos immunoreactivity that are consistent with vasotocin functioning as a hormone, and support the role of hypothalamic structures in the response to disruption of salt and water balance in this snake. PMID:17703311

Zambotti-Villela, Leonardo; Marinho, Camila Eduardo; Alponti, Rafaela Fadoni; Silveira, Paulo Flavio

2007-08-17

46

Bothrops jararaca Peptide with Anti-Hypertensive Action Normalizes Endothelium Dysfunction Involved in Physiopathology of Preeclampsia  

PubMed Central

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia.

Benedetti, Gabriel; Morais, Katia L. P.; Guerreiro, Juliano R.; de Oliveira, Eduardo Fontana; Hoshida, Mara Sandra; Oliveira, Leandro; Sass, Nelson; Lebrun, Ivo; Ulrich, Henning; Lameu, Claudiana; de Camargo, Antonio Carlos Martins

2011-01-01

47

The GATA factor Serpent cross-regulates lozenge and u-shaped expression during Drosophila blood cell development  

PubMed Central

The Drosophila GATA factor Serpent interacts with the RUNX factor Lozenge to activate the crystal cell program, whereas SerpentNC binds the Friend of GATA protein U-shaped to limit crystal cell production. Here, we identified a lozenge minimal hematopoietic cis-regulatory module and showed that lozenge-lacZ reporter-gene expression was autoregulated by Serpent and Lozenge. We also showed that upregulation of u-shaped was delayed until after lozenge activation, consistent with our previous results that showed u-shaped expression in the crystal cell lineage is dependent on both Serpent and Lozenge. Together, these observations describe a feed forward regulatory motif, which controls the temporal expression of u-shaped. Finally, we showed that lozenge reporter-gene activity increased in a u-shaped mutant background and that forced expression of SerpentNC with U-shaped blocked lozenge- and u-shaped-lacZ reporter-gene activity. This is the first demonstration of GATA:FOG regulation of Runx and Fog gene expression. Moreover, these results identify components of a Serpent cross-regulatory sub-circuit that can modulate lozenge expression. Based on the sub-circuit design and the combinatorial control of crystal cell production, we present a model for the specification of a dynamic bi-potential regulatory state that contributes to the selection between a Lozenge-positive and Lozenge-negative state.

Muratoglu, Selen; Hough, Barry; Mon, Soe T.; Fossett, Nancy

2007-01-01

48

Purification and functional characterization of bothrojaractivase, a prothrombin-activating metalloproteinase isolated from Bothrops jararaca snake venom.  

PubMed

Bleeding at the site of bite and/or systemic hemorrhage are symptoms frequently observed in envenomation by Bothrops jararaca snakes. In this study, we purified and characterized a prothrombin activator from B. jararaca that is probably involved in these clinical manifestations. The enzyme was isolated by a combination of gel filtration and ion exchange chromatographies and named bothrojaractivase. It has a single polypeptide chain with a molecular weight of 22,829 Da as measured by mass spectroscopy. Bothrojaractivase generates active thrombin from prothrombin, independently of cofactors. SDS-PAGE analysis of the prothrombin activation products shows that bothrojaractivase converts prothrombin into meizothrombin producing similar fragments to those generated by group A prothrombin's activators. In addition, bothrojaractivase degraded fibrinogen and fibrin. Chelating agents completely inhibited the enzymatic activity, whereas inhibitors of serine and cysteine proteinases had no effect. Amino acid sequence of four peptides demonstrated high similarity of bothrojaractivase with P-I class of snake venom metalloproteinases. Thus, our results indicate that bothrojaractivase is a new metalloproteinase that acts on different protein factors of the clotting cascade especially displaying a key and most relevant functional action in the generation of thrombin through prothrombin activation in a similar mode of action as that of group A activators. PMID:18262582

Berger, Markus; Pinto, Antônio F M; Guimarães, Jorge A

2008-02-11

49

Revised methods for few-group cross sections generation in the Serpent Monte Carlo code  

SciTech Connect

This paper presents new calculation methods, recently implemented in the Serpent Monte Carlo code, and related to the production of homogenized few-group constants for deterministic 3D core analysis. The new methods fall under three topics: 1) Improved treatment of neutron-multiplying scattering reactions, 2) Group constant generation in reflectors and other non-fissile regions and 3) Homogenization in leakage-corrected criticality spectrum. The methodology is demonstrated by a numerical example, comparing a deterministic nodal diffusion calculation using Serpent-generated cross sections to a reference full-core Monte Carlo simulation. It is concluded that the new methodology improves the results of the deterministic calculation, and paves the way for Monte Carlo based group constant generation. (authors)

Fridman, E. [Reactor Safety Div., Helmholz-Zentrum Dresden-Rossendorf, POB 51 01 19, Dresden, 01314 (Germany); Leppaenen, J. [VTT Technical Research Centre of Finland, POB 1000, FI-02044 VTT (Finland)

2012-07-01

50

EXPLANATION OF THE SEA-SERPENT MAGNETIC STRUCTURE OF SUNSPOT PENUMBRAE  

SciTech Connect

Recent spectro-polarimetric observations of a sunspot showed the formation of bipolar magnetic patches in the mid-penumbra and their propagation toward the outer penumbral boundary. The observations were interpreted as being caused by sea-serpent magnetic fields near the solar surface. In this Letter, we develop a three-dimensional radiative MHD numerical model to explain the sea-serpent structure and the wave-like behavior of the penumbral magnetic field lines. The simulations reproduce the observed behavior, suggesting that the sea-serpent phenomenon is a consequence of magnetoconvection in a strongly inclined magnetic field. It involves several physical processes: filamentary structurization, high-speed overturning convective motions in strong, almost horizontal magnetic fields with partially frozen field lines, and traveling convective waves. The results demonstrate a correlation of the bipolar magnetic patches with high-speed Evershed downflows in the penumbra. This is the first time that a three-dimensional numerical model of the penumbra results in downward-directed magnetic fields, an essential ingredient of sunspot penumbrae that has eluded explanation until now.

Kitiashvili, I. N. [Center for Turbulence Research, Stanford University, Stanford, CA 94305 (United States); Bellot Rubio, L. R. [Instituto de Astrofisica de AndalucIa (CSIC), Apdo. de Correos 3004, E-18080 Granada (Spain); Kosovichev, A. G. [NORDITA, Department of Astronomy, AlbaNova University Center, SE 10691 Stockholm (Sweden); Mansour, N. N.; Wray, A. A. [NASA Ames Research Center, Moffett Field, Mountain View, CA 94040 (United States); Sainz Dalda, A., E-mail: irinasun@stanford.ed [Stanford-Lockheed Institute for Space Research, Stanford, CA 94305 (United States)

2010-06-20

51

Cloning and Sequence Analysis of a Bothrops jararaca cDNA Encoding a Precursor of Seven Bradykinin-Potentiating Peptides and a C-Type Natriuretic Peptide  

Microsoft Academic Search

A 1.8-kb cDNA clone was isolated from a Bothrops jararaca venom gland cDNA library that encodes a 256-aa precursor for bradykinin-potentiating peptides (angiotensin-converting enzyme inhibitors) and a C-type natriuretic peptide (CNP). The seven bradykinin-potentiating peptides are aligned tandemly after the hydrophobic signal peptide sequence, followed by a putative intervening sequence and a CNP at the C terminus. Northern blot analysis

Nobuhiro Murayama; Mirian A. F. Hayashi; Hiroaki Ohi; Luiza A. F. Ferreira; Vivian V. Hermann; Hiromi Saito; Yoshiaki Fujita; Shigesada Higuchi; Beatriz L. Fernandes; Tetsuo Yamane; Antonio C. M. de Camargo

1997-01-01

52

Identification of proteins similar to Bothrops jararaca coagulation inhibitor (BjI) in the plasmas of Bothrops alternatus, Bothrops jararacussu and Crotalus durissus terrificus snakes.  

PubMed

Bothrops jararaca coagulation inhibitor (BjI), a protein isolated from B. jararaca plasma, specifically inhibits the coagulant activity of thrombin. Our group previously identified proteins similar to BjI in the plasma of other snakes [Tanaka-Azevedo, A.M., Tanaka, A.S., Sano-Martins I.S., 2003. A new blood coagulation inhibitor from the snake Bothrops jararaca plasma: isolation and characterization. Biochem Biophys Res Commun 308, 706-712.]. In the present study, we analyzed the presence of BjI-like proteins in the plasmas of three different species of viperid snakes, Bothrops alternatus, Bothrops jararacussu and Crotalus durissus terrificus. These proteins exhibited 109 and/or 138 kDa and were immunologically related to BjI. They also inhibited the coagulant activity of thrombin, evaluated by the thrombin time test. These findings demonstrate the presence of proteins similar to BjI in these three species, although such inhibitor could not be observed in all samples of the specimens tested. Moreover, the presence of these proteins in the plasma is related to prolongation of thrombin time, implying a relationship between these proteins and their inhibitory coagulant activity upon thrombin. Our results suggest that BjI-like proteins are widely distributed among Crotalinae snakes found in Brazil. PMID:17931922

de Morais, Karen Batista; Fernandes Grego, Kathleen; Tanaka-Azevedo, Anita Mitico

2007-09-20

53

Renal sexual segment of the Cottonmouth snake, Agkistrodon piscivorous (Reptilia, Squamata, Viperidae).  

PubMed

The seasonal variation of the renal sexual segment (RSS) of males of the Cottonmouth snake, Agkistrodon piscivorous, is described using light and electron microscopy. This study is the first to describe the ultrastructure of the RSS of a viper (Viperidae) and only the fourth on a snake. Renal sexual segments from males collected February to May and from August to November are similar in appearance. The cells are eosinophilic and react with periodic acid/Schiff procedure (PAS) for neutral carbohydrates and bromphenol blue (BB) for proteins. At the ultrastructure level, the cells contain large (2 microm diameter), electron-dense secretory granules and smaller vesicles with a diffuse material, and these structures abut against the luminal border and upon clear vacuoles continuous with intercellular canaliculi. Evidence was found for both apocrine and merocrine processes of product release. In June and July, the RSS are significantly smaller in diameter, largely basophilic, and have only scattered granules that are PAS+ and BB+. Cytologically, the RSS from June to July lack electron-dense secretory granules and the smaller vesicles with diffuse material. Numerous condensing vacuoles and abundant rough endoplasmic reticulum, however, indicate that active product synthesis is occurring. This is the first report of significant seasonal variation in the histology and ultrastructure of the RSS of a snake, although such reports exist for lizards. The seasons when the RSS is most highly hypertrophied correspond to the fall and spring mating seasons of A. piscivorous, as determined by other studies. PMID:17999397

Sever, David M; Siegel, Dustin S; Bagwill, April; Eckstut, Mallory E; Alexander, Laura; Camus, Angelle; Morgan, Colby

2008-06-01

54

Lachesis muta (Viperidae) cDNAs Reveal Diverging Pit Viper Molecules and Scaffolds Typical of Cobra (Elapidae) Venoms: Implications for Snake Toxin Repertoire Evolution  

PubMed Central

Efforts to describe toxins from the two major families of venomous snakes (Viperidae and Elapidae) usually reveal proteins belonging to few structural types, particular of each family. Here we carried on an effort to determine uncommon cDNAs that represent possible new toxins from Lachesis muta (Viperidae). In addition to nine classes of typical toxins, atypical molecules never observed in the hundreds of Viperidae snakes studied so far are highly expressed: a diverging C-type lectin that is related to Viperidae toxins but appears to be independently originated; an ohanin-like toxin, which would be the third member of the most recently described class of Elapidae toxins, related to human butyrophilin and B30.2 proteins; and a 3FTx-like toxin, a new member of the widely studied three-finger family of proteins, which includes major Elapidae neurotoxins and CD59 antigen. The presence of these common and uncommon molecules suggests that the repertoire of toxins could be more conserved between families than has been considered, and their features indicate a dynamic process of venom evolution through molecular mechanisms, such as multiple recruitments of important scaffolds and domain exchange between paralogs, always keeping a minimalist nature in most toxin structures in opposition to their nontoxin counterparts.

Junqueira-de-Azevedo, Inacio L. M.; Ching, Ana T. C.; Carvalho, Eneas; Faria, Fernanda; Nishiyama, Milton Y.; Ho, Paulo L.; Diniz, Marcelo R. V.

2006-01-01

55

Contribution of mast cells and snake venom metalloproteinases to the hyperalgesia induced by Bothrops jararaca venom in rats.  

PubMed

Bothrops jararaca venom (Bjv) is known to induce local inflammation and severe pain. Since, mast cells are able to secrete mediators involved in algesic processes, in this study we examined the putative role of these cells in the hyperalgesia triggered by Bjv in the rat paw. We noted that treatment with mast cell stabilizer sodium cromoglicate as well as with histamine and 5-hydroxytriptamine receptor antagonists meclizine and methysergide, respectively, inhibited the Bjv-induced hyperalgesia. In addition, we showed that stimulation of isolated rat peritoneal mast cells with Bjv in vitro resulted in the release of stored and neo-generated inflammatory mediators such as histamine and leukotriene C(4), respectively. Bjv-induced histamine secretion was clearly sensitive to treatment with sodium cromoglicate and sodium nedocromil. We further observed that metalloproteinase inhibitors 1,10-phenantroline and DM43 inhibited mast cell degranulation in vitro, under conditions where inhibitors of phospholipase A(2) as well as of serine- and cysteine-proteinases were inactive. Altogether, our findings indicate that mast cells seem to contribute to the hyperalgesia caused by Bjv in the rat paw, and also provide evidence that this response might be dependent on the ability of the Bjv to activate directly mast cells. PMID:16730041

Bonavita, André Gustavo C; da Costa, Aline S; Pires, Ana Lucia A; Neves-Ferreira, Ana G C; Perales, Jonas; Cordeiro, Renato S B; Martins, Marco A; e Silva, Patrícia M R

2006-03-24

56

Simplified procedures for the isolation of HF3, bothropasin, disintegrin-like/cysteine-rich protein and a novel P-I metalloproteinase from Bothrops jararaca venom.  

PubMed

HF3 and bothropasin are P-III hemorrhagic snake venom metalloproteinases (SVMPs) of Bothrops jararaca. The DC protein is composed of the disintegrin-like/cysteine-rich domains derived from the autolysis of P-III SVMPs. Here we describe simplified procedures for the isolation of HF3, bothropasin, the DC protein, and BJ-PI, a novel P-I SVMP. The isolated proteins were identified by mass spectrometry. BJ-PI is a potent caseinolytic enzyme devoid of hemorrhagic activity. HF3, bothropasin and BJ-PI show distinct fibrinogenolytic activities. PMID:19254739

Oliveira, Ana K; Paes Leme, Adriana F; Assakura, Marina T; Menezes, Milene C; Zelanis, André; Tashima, Alexandre K; Lopes-Ferreira, Mônica; Lima, Carla; Camargo, Antonio C M; Fox, Jay W; Serrano, Solange M T

2009-02-28

57

Avian pox infection in a free-living crested serpent eagle (Spilornis cheela) in southern Taiwan.  

PubMed

Avian pox viruses (APVs) have been reported to cause infection in diverse avian species worldwide. Herein we report the first case of APV infection in a free-living bird, a subadult crested serpent eagle (Spilornis cheela), in Taiwan. In addition to the typical wart-like lesions distributed on the cere, eyelid, and face, there were also yellowish nodules below the tongue and on the hard palate. Phylogenetic analysis of the 4b core protein gene showed that the APV is very close to that found in white-tailed sea eagle (Haliaeetus albicilla) in Japan recently. Because both cases are located on the same major flyway for migratory birds, the impact of this virus with regard to the wild and migratory raptor species along the East Asian-Australasian Flyway and West Pacific Flyway requires immediate investigation. PMID:21500652

Chen, C C; Pei, K J C; Lee, F R; Tzeng, M P; Chang, T C

2011-03-01

58

Hematocrit and plasma chemistry values in adult collared scops owls (Otus lettia) and crested serpent eagles (Spilornis cheela hoya).  

PubMed

In this study, we report hematocrit and plasma chemistry values for adult captive collared scops owls (Otus lettia) and crested serpent eagles (Spilornis cheela hoya). In particular, we address the gender-specific differences within these values. We measured hematocrit (HCT) and plasma chemistry values for uric acid (UA), plasma urea nitrogen (BUN), total protein (TP), albumin (ALB), glucose (GLU), cholesterol (CHO), triglyceride (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), total bilirubin (TBIL), creatine (CRE), creatine phosphokinase (CPK), amylase (AMY), calcium (CA), ionic phosphorous (IP) and sodium (NA), potassium (K) and chloride ions (CL) in 37 adult captive collared scops owls and 39 adult captive crested serpent eagles. Significant differences between the sexes were found for UA, GLU and CPK in the collared scope owls. UA and GLU concentrations were significantly higher (P<0.01 and P<0.05) among males than females, while the CPK concentration was significantly lower (P<0.05) in males. There were no significant differences in of all of the measured parameters between male and female eagles. These finding suggested that HCT and plasma chemistry values of raptors vary individually according to species and sex. Our results provide the 1st available reference data for ranges of plasma values in adult captive collared scops owls and crested serpent eagles, making them a potentially useful complementary diagnostic tool for veterinary care of individuals for both species in captivity. PMID:22446394

Chan, Fang-Tse; Lin, Pei-I; Chang, Geng-Ruei; Wang, Hsien-Chi; Hsu, Tien-Huan

2012-03-09

59

The GATA factor Serpent is required for the onset of the humoral immune response in Drosophila embryos  

PubMed Central

Innate immunity in Drosophila is characterized by the inducible expression of antimicrobial peptides. We have investigated the development and regulation of immune responsiveness in Drosophila embryos after infection. Immune competence, as monitored by the induction of Cecropin A1-lacZ constructs, was observed first in the embryonic yolk. This observation suggests that the yolk plays an important role in the humoral immune response of the developing embryo by synthesizing antimicrobial peptides. Around midembryogenesis, the response in the yolk was diminished. Simultaneously, Cecropin expression became inducible in a large number of cells in the epidermis, demonstrating that late-stage embryos can synthesize their own antibiotics in the epidermis. This production likely serves to provide the hatching larva with an active antimicrobial barrier and protection against systemic infections. Cecropin expression in the yolk required the presence of a GATA site in the promoter as well as the involvement of the GATA-binding transcription factor Serpent (dGATAb). In contrast, neither the GATA site nor Serpent were necessary for Cecropin expression in the epidermis. Thus, the inducible immune responses in the yolk and in the epidermis can be uncoupled and call for distinct sets of transcription factors. Our data suggest that Serpent is involved in the distinction between a systemic response in the yolk/fat body and a local immune response in epithelial cells. In addition, the present study shows that signal transduction pathways controlling innate and epithelial defense reactions can be dissected genetically in Drosophila embryos.

Tingvall, Tove Onfelt; Roos, Erik; Engstrom, Ylva

2001-01-01

60

Contribution of metalloproteases, serine proteases and phospholipases A2 to the inflammatory reaction induced by Bothrops jararaca crude venom in mice.  

PubMed

Various toxins isolated from Bothrops snake venoms induce inflammatory reactions and have been claimed to contribute to the severity of local symptoms present in this envenomation. Notwithstanding, the relative participation of serine proteases, metalloproteases and phospholipases A(2) in the inflammatory reaction produced by crude Bothrops venoms is poorly understood. Herein, crude Bothrops jararaca venom was treated with phenylmethanesulfonyl fluoride (PMSF), 1,10-phenanthroline (oPhe), or p-bromophenacyl-bromide (p-BPB) to inhibit those classes of enzymes, respectively, and inflammatory parameters were evaluated and compared to those induced by the control crude venom. The intensity of edema and hyperalgesia/allodynia was remarkably reduced in animals administered with oPhe-treated venom. Leukocyte-endothelium interactions (LEI), such as adhesion and migration of leukocytes, were also modified at 2h and 24h. Edema and LEI parameters induced by p-BPB-treated venom were similar to those observed with the control venom, but hyperalgesia/allodynia was significantly lower. Inflammatory parameters induced by PMSF-treated venom were similar to those induced by the crude venom, except for a mild reduction in edema intensity. Our results indicate that metalloproteases have a pivotal role in the inflammatory reactions induced by B. jararaca venom, and phospholipases A(2) and serine proteases have a minor role. PMID:19646466

Zychar, Bianca Cestari; Dale, Camila Squazoni; Demarchi, Denise Soares; Gonçalves, Luis Roberto C

2009-07-29

61

Elucidation of trends within venom components from the snake families Elapidae and Viperidae using gel filtration chromatography.  

PubMed

Research into snake venom components has intensified over the last number of decades, particularly that work directed towards the discovery of novel agents with potential applications in clinical therapy. In the present study we report, for the first time, defined patterns observed in the G-50 chromatographic elution profiles from 30 snake venoms taken from Elapidae and Viperidae families, as well as previously unreported patterns within subfamilies of these snake species. Development of this chromatographic technique thus offers a rapid method for the general classification of snakes within these families as well as providing insights into hitherto uncharacterised trends within the venoms of snake subfamilies that have opened new avenues for further investigation. PMID:17936867

Graham, Robert Leslie James; Graham, Ciaren; Theakston, David; McMullan, Geoff; Shaw, Chris

2007-09-02

62

[Sequencing and analysis of the complete mitochondrial genome of the King Cobra, Ophiophagus hannah (Serpents: Elapidae)].  

PubMed

We obtained the complete mitochondrial genome of King Cobra(GenBank accession number: EU_921899) by Ex Taq-PCR, TA-cloning and primer-walking methods. This genome is very similar to other vertebrate, which is 17 267 bp in length and encodes 38 genes (including 13 protein-coding, 2 ribosomal RNA and 23 transfer RNA genes) and two long non-coding regions. The duplication of tRNA-Ile gene forms a new mitochondrial gene rearrangement model. Eight tRNA genes and one protein genes were transcribed from L strand, and the other genes were transcribed genes from H strand. Genes on the H strand show a fairly similar content of Adenosine and Thymine respectively, whereas those on the L strand have higher proportion of A than T. Combined rDNA sequence data (12S+16S rRNA) were used to reconstruct the phylogeny of 21 snake species for which complete mitochondrial genome sequences were available in the public databases. This large data set and an appropriate range of outgroup taxa demonstrated that Elapidae is more closely related to colubridae than viperidae, which supports the traditional viewpoints. PMID:20650853

Chen, Nian; Lai, Xiao-Ping

2010-07-01

63

Type specimens of Crotalus scutulatus (Chordata: Reptilia: Squamata: Viperidae) re-examined, with new evidence after more than a century of confusion  

USGS Publications Warehouse

The original description of Crotalus scutulatus (Chordata: Reptilia: Squamata: Viperidae) was published in 1861 by Robert Kennicott, who did not identify a type specimen or a type locality. We review the history of specimens purported to be the type(s) and various designations of type locality. We provide evidence that ANSP 7069 (formerly one of two specimens of USNM 5027) is the holotype and that the appropriate type locality is Fort Buchanan, near present-day Sonoita, in Santa Cruz County, Arizona.

Cardwell, Michael D.; Gotte, Steve W.; McDiarmid, Roy W.; Gilmore, Ned; Poindexter, James A., II

2013-01-01

64

The hemoglobin system of the serpent eel Ophisurus serpens: structural and functional characterization.  

PubMed

The hemoglobin system of the serpent eel Ophisurus serpens was structurally and functionally characterized with the aim of comparing it to the hemoglobin system of other fish species, as oxygen loading under the severe habitat conditions experienced by O. serpens could have necessitated specific adaptation mechanisms during evolution. The hemoglobin system of O. serpens includes one cathodic and four anodic components. The molecular mass of the ? and ? chains of the cathodic component as well as the 2 ? and 4 ? of the anodic components were determined. Analysis of the intact ? and ? chains from cathodic hemoglobin and their proteolytic digestion products by high-resolution MS and MS/MS experiments resulted in 92 and 95 % sequence coverage of the ? and ? globins, respectively. The oxygen binding properties of both hemoglobin components were analyzed with respect to their interactions with their physiological effectors. Stripped cathodic hemoglobin displayed the highest oxygen affinity among Anguilliformes with no significant effect of pH on O2-affinity. In the presence of both chloride and organic phosphates, O2-affinity was strongly reduced, and cooperativity was enhanced; moreover, cathodic hemoglobin contains two indistinguishable GTP-binding sites. Stripped anodic hemoglobins exhibited both low O2-affinity and low cooperativity and a larger Bohr effect than cathodic hemoglobin. The cathodic hemoglobin of O. serpens and the corresponding component of Conger conger share the greatest structural and functional similarity among hemoglobin systems of Anguilliformes studied to date, consistent with their phylogenetic relationship. PMID:23632627

Manconi, Barbara; Pellegrini, Mariagiuseppina; Messana, Irene; Sanna, Maria Teresa; Castagnola, Massimo; Iavarone, Federica; Coluccia, Elisabetta; Giardina, Bruno; Olianas, Alessandra

2013-04-30

65

Discovery of microscopic evidence for shock metamorphism at the Serpent Mound structure, south-central Ohio: Confirmation of an origin by impact  

USGS Publications Warehouse

The origin of the Serpent Mound structure in south-central Ohio has been disputed for many years. Clearly, more evidence was needed to resolve the confusion concerning the origin of the Serpent Mound feature either by endogenic processes or by hypervelocity impact. A petrographic study of 21 samples taken from a core 903 m long drilled in the central uplift of the structure provides evidence of shock metamorphism in the form of multiple sets of planar deformation features in quartz grains, as well as the presence of clasts of altered impact-melt rock. Crystallographic orientations of the planar deformation features show maxima at the shock-characteristic planes of {101??3} and {101??2} and additional maxima at {101??1}, {213??1}, and {516??1}. Geochemical analyses of impact breccias show minor enrichments in the abundances of the siderophile elements Cr, Co, Ni, and Ir, indicating the presence of a minor meteoritic component.

Carlton, R. W.; Koeberl, C.; Baranoski, M. T.; SchuMacHer, G. A.

1998-01-01

66

Use of random amplified polymorphic DNA to identify several novel markers for sex identification in the crested serpent eagle and crested goshawk  

Microsoft Academic Search

The crested serpent eagle (Spilornis cheela hoya) has no distinct sexual dimorphic traits. In the current study, we report the results of an EE0.6 (EcoRI 0.6-kb fragment) sequence applied to S. cheela hoya and a novel random amplified polymorphic DNA (RAPD) marker that can be used to sex individuals within the species S. cheela hoya and Accipiter trivigatus formosae (crested

H. A. Hsu; P. H. Wang; M. C. Chao; F. T. Chan; L. M. Wang; P. I. Lin; C. H. Chang; H. W. Yuan; S. T. Ding

2009-01-01

67

Re-Os isotope systematics in carbonates from Serpent Mound, Ohio: Implications for Re-Os dating of crustal rocks and the osmium isotopic composition of Ordovician seawater  

Microsoft Academic Search

Eleven core samples of Ordovician carbonates and shale from within and nearby the Serpent Mound (Ohio) cryptoexplosion structure were analyzed for Re-Os isotopes. Whole-rock samples span a large range in measured 187Os\\/188Os (0.714 to 6.083), and exhibit a linear correlation of 187Os\\/188Os with 187Re\\/188Os. The linear relationship is inconsistent with a meteorite-crust mixing trend, but could represent an errorchron with

Elisabeth Widom; Sarah J. Gaddis; Norman E. Wells Jr

2004-01-01

68

Brain nitric oxide production by a proline-rich decapeptide from Bothrops jararaca venom improves baroreflex sensitivity of spontaneously hypertensive rats.  

PubMed

Baroreflex sensitivity is disturbed in many people with cardiovascular diseases such as hypertension. Brain deficiency of nitric oxide (NO), which is synthesized by NO synthase (NOS) in the citrulline-NO cycle (with argininosuccinate synthase (ASS) activity being the rate-limiting step), contributes to impaired baroreflex. We recently showed that a decapeptide isolated from Bothrops jararaca snake venom, denoted Bj-PRO-10c, exerts powerful and sustained antihypertensive activity. Bj-PRO-10c promoted vasodilatation dependent on the positive modulation of ASS activity and NO production in the endothelium, and also acted on the central nervous system, inducing the release of GABA and glutamate, two important neurotransmitters in the regulation of autonomic systems. We evaluated baroreflex function using the regression line obtained by the best-fit points of measured heart rate (HR) and mean arterial pressure (MAP) data from spontaneously hypertensive rats (SHRs) treated with Bj-PRO-10c. We also investigated molecular mechanisms involved in this effect, both in vitro and in vivo. Bj-PRO-10c mediated an increase in baroreflex sensitivity and a decrease in MAP and HR. The effects exerted by the peptide include an increase in the gene expression of endothelial NOS and ASS. Bj-PRO-10c-induced NO production depended on intracellular calcium fluxes and the activation of a G(i/o)-protein-coupled metabotropic receptor. Bj-PRO-10c induced NO production and the gene expression of ASS and endothelial NOS in the brains of SHRs, thereby improving baroreflex sensitivity. Bj-PRO-10c may reveal novel approaches for treating diseases with impaired baroreflex function. PMID:21132021

Lameu, Claudiana; Pontieri, Vera; Guerreiro, Juliano R; Oliveira, Eduardo F; da Silva, Carlos Alberto; Giglio, Joyce M; Melo, Robson L; Campos, Ruy R; de Camargo, Antonio Carlos Martins; Ulrich, Henning

2010-12-01

69

Pharmacological characterisation of arthritis induced by Bothrops jararaca venom in rabbits: a positive cross talk between bradykinin, nitric oxide and prostaglandin E2.  

PubMed Central

BACKGROUND: Our previous results showed that nitric oxide (NO) and bradykinin (BK) mediate the arthritis induced by Bothrops jararaca venom (BjV) in rabbits. In this study, we investigated the contribution of each receptor of BK as well as the inter-relationship between NO and eicosanoids in BjV-induced arthritis. METHODS: The arthritis was induced in rabbits with 16 microg of BjV injected intra-articularly. Prostaglandin E2 (PGE2), thromboxane B2 (TxB2), leukotriene B4 (LTB4) (radioimmunoassay) and nitrite/nitrate concentrations (NO2/NO3) (Griess reaction) were evaluated in the synovial fluid 4 h later. The animals were prior treated with NO synthase inhibitor (L-NAME; 20 mg/kg/day for 14 days), the B2 antagonist of BK (HOE-140) and the B1 antagonist of BK (des-Arg9[Leu8]-bradykinin), both at a dose of 0.3mg/kg, 30 min prior to the venom injection. RESULTS: Data show that L-NAME and HOE-140 treatment were equally able to reduce PGE2 and NO2/NO3 levels without interfering with TxB2 and LTB4 production. On the contrary, the B1 antagonist of BK inhibited TxB2 and LTB4 production, and did not alter PGE2 and NO metabolites levels in the inflamed joint. DISCUSSIONS: The results presented clarify the contribution of the kinin system, mainly through the B2 receptor, to the local inflammatory response induced by BjV, as well as its positive interaction with PGE2 and NO production.

Mello, Suzana B V; Guzzo, Maria Luiza; Lisboa, Luiz Filipe Santiago; Farsky, Sandra H P

2002-01-01

70

A novel phospholipase A2, BJ-PLA2, from the venom of the snake Bothrops jararaca: purification, primary structure analysis, and its characterization as a platelet-aggregation-inhibiting factor.  

PubMed

This paper describes the isolation and primary structure analysis of a new phospholipase A2 with platelet-aggregation-inhibiting activity from the venom of Bothrops jararaca. The protein, named BJ-PLA2, was isolated by means of ammonium sulfate precipitation and anion-exchange and reversed-phase chromatographies and behaved as a homogeneous single-chain protein on SDS-PAGE. Its amino acid sequence was determined by N-terminal sequencing and analysis of overlapped chemical and proteolytic fragments by automated Edman degradation and mass spectometry determination. BJ-PLA2 consists of 124 amino acid residues and has the structural features of snake venom class II phospholipases A2. Chemical modification with p-bromophenacylbromide caused complete loss of enzymatic activity and partially affected the platelet-aggregation-inhibiting activity of BJ-PLA2. PMID:10375395

Serrano, S M; Reichl, A P; Mentele, R; Auerswald, E A; Santoro, M L; Sampaio, C A; Camargo, A C; Assakura, M T

1999-07-01

71

The Descent of the Serpent: Using a Successful Ancient Solar Observatories Webcast from Chichen Itza to Highlight Space Weather Research  

NASA Astrophysics Data System (ADS)

Over the past seven years, NASA's Sun-Earth Connection Education Forum has sponsored and coordinated education and public outreach events to highlight NASA's heliophysics research and discoveries. Our strategy involves using celestial events, such as total solar eclipses and the Transit of Venus, as well as Sun-Earth Day during the March Equinox, to engage K-12 schools and the general public in space science activities, demonstrations, and interactions with space scientists. In collaboration with partners that include the Exploratorium and other museums, Ideum, NASA TV, NASA heliophysics missions, and others, we produce webcasts, other multi-media, and print resources for use by school and informal educators nation-wide and internationally. We provide training and professional development to K-12 educators, museum personnel, amateur astronomers, Girl Scout leaders, etc., so they can implement their own outreach programs taking advantage of our resources. A coordinated approach promotes multiple programs occurring each year under a common theme. As part of an Ancient Observatories theme in 2005, we have successfully featured solar alignments with ancient structures made by indigenous cultures that mark the equinoxes and/or solstices in cultural and historical parks in the Americas. In partnership with the Exploratorium, we produced broadcast-quality and webcast programming during the March equinox that shared heliophysics within a broad cultural context with formal and informal education audiences internationally. The program: "Descent of the Serpent" featured the light and shadow effect at sunset that takes place during the spring equinox at the Pyramid of El Castillo, in Chichén Itzá (México). This program made unique and authentic cultural connections to the knowledge of solar astronomy of the Maya, the living Mayan culture of today, and the importance of the Sun across the ages. We involved Sun-Earth Connection scientists, their missions, and research programs from México and the US to share NASA solar research with diverse audiences in the US and across the world, and to share how our dynamic Sun impacts the Earth and other planets in the solar system. During our presentation, we will highlight the strategies we used to successfully engage Hispanics of native heritage in heliophysics from all over the world.

Hawkins, I.; Higdon, R.; Cline, T.

2006-12-01

72

Use of random amplified polymorphic DNA to identify several novel markers for sex identification in the crested serpent eagle and crested goshawk.  

PubMed

The crested serpent eagle (Spilornis cheela hoya) has no distinct sexual dimorphic traits. In the current study, we report the results of an EE0.6 (EcoRI 0.6-kb fragment) sequence applied to S. cheela hoya and a novel random amplified polymorphic DNA (RAPD) marker that can be used to sex individuals within the species S. cheela hoya and Accipiter trivigatus formosae (crested goshawk). We used sex-specific primers for the avian CHD1 (chromo-helicase-DNA-binding 1) gene and the EE0.6 sequence in PCR assays to determine sex. In addition, 120 random primers were used for RAPD fingerprinting to search for novel sex-specific fragments of S. cheela hoya. The OPBB08 random primer generated a 1241-bp sex-specific fragment in all female S. cheela hoya. From the nucleotide sequence, PCR primers were designed to amplify 553-, 895-, and 194-bp sex-specific fragments present in all female S. cheela hoya. One of these primer pairs (ScBB08-7F/R) also amplified a male/female common fragment that can be used as an internal control (543bp). Moreover, one of the primer pairs (ScBB08-5aF/5bR) could be used to identify genders of A. trivigatus formosae. In conclusion, we identified novel sex-specific DNA markers of S. cheela hoya and A. trivigatus formosae that can be used for rapid and accurate sex identification. PMID:19560806

Hsu, H A; Wang, P H; Chao, M C; Chan, F T; Wang, L M; Lin, P I; Chang, C H; Yuan, H W; Ding, S T

2009-06-27

73

Ordeal by serpents, fire and strychnine  

Microsoft Academic Search

Summary Some of the cultural and psychodynamic background factors in the members of the Free Pentacostal Holiness Church are described. Particular attention is devoted to the relationship between their states of exaltation that occur during the religious services and the more than 200 observed instances of successful manipulation of poisonous rattlesnakes and copperheads. Also the salient details are given of

Berthold E. Schwarz

1960-01-01

74

First Results from SERPENT Marine MT Study  

NASA Astrophysics Data System (ADS)

In April 2010 we conducted a controlled source electromagnetic (CSEM) and magnetotelluric (MT) survey over the Middle Americas subduction zone offshore Nicaragua. Seismic and heat flow studies have been conducted in the region to explore the role water plays at convergent margins, yet the quantity of water entering the downgoing slab remains poorly constrained. Electrical conductivity, however, is highly sensitive to the amount and distribution of water in the crust, and possibly mantle. Our broadband marine MT receivers recorded electric and magnetic field variations at the seafloor in water depths ranging from 60-5100 m. A total of 54 receiver deployments along a 300 km profile resulted in the largest MT dataset ever collected over an active subduction zone, all recorded in a single 28 day cruise aboard the R/V Melville. Spectrograms of the raw data show strong signal, including a significant magnetic storm from 5/2 to 5/3. Robust multiple station processing of the MT data produced high quality apparent resistivity and phase estimates for periods of roughly 10-20,000 s. Impedance polar diagrams and skew estimates display an evolution of 1D structure on the abyssal plain, 2D structure at the outer rise, 3D structure on/near the trench, and 1D-2D structure along the continental shelf. The MT responses generally lack the severe anisotropy usually associated with the ocean-side coast effect in near-shore MT studies. However, large distortions are evident at a few sites on the prism side of the trench, where extremely high skews are strongly localized in both space and frequency; these are spatially correlated with cusps in apparent resistivity and negative phase wrapping of the TE mode. We suspect this is caused by a combination of severe bathymetric effects and local variations in conductivity structure. Initial modeling results will be presented.

Naif, S.; Key, K. W.; Constable, S.; Evans, R. L.

2010-12-01

75

Body Size Evolution in Insular Speckled Rattlesnakes (Viperidae: Crotalus mitchellii)  

PubMed Central

Background Speckled rattlesnakes (Crotalus mitchellii) inhabit multiple islands off the coast of Baja California, Mexico. Two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. We examined body size variation between island and mainland speckled rattlesnakes, and the relationship between body size and various island physical variables among 12 island populations. We also examined relative head size among giant, dwarfed, and mainland speckled rattlesnakes to determine whether allometric differences conformed to predictions of gape size (and indirectly body size) evolving in response to shifts in prey size. Methodology/Principal Findings Insular speckled rattlesnakes show considerable variation in body size when compared to mainland source subspecies. In addition to previously known instances of gigantism on Ángel de la Guarda and dwarfism on El Muerto, various degrees of body size decrease have occurred frequently in this taxon, with dwarfed rattlesnakes occurring mostly on small, recently isolated, land-bridge islands. Regression models using the Akaike information criterion (AIC) showed that mean SVL of insular populations was most strongly correlated with island area, suggesting the influence of selection for different body size optima for islands of different size. Allometric differences in head size of giant and dwarf rattlesnakes revealed patterns consistent with shifts to larger and smaller prey, respectively. Conclusions/Significance Our data provide the first example of a clear relationship between body size and island area in a squamate reptile species; among vertebrates this pattern has been previously documented in few insular mammals. This finding suggests that selection for body size is influenced by changes in community dynamics that are related to graded differences in area over what are otherwise similar bioclimatic conditions. We hypothesize that in this system shifts to larger prey, episodic saturation and depression of primary prey density, and predator release may have led to insular gigantism, and that shifts to smaller prey and increased reproductive efficiency in the presence of intense intraspecific competition may have led to insular dwarfism.

Meik, Jesse M.; Lawing, A. Michelle; Pires-daSilva, Andre

2010-01-01

76

Feeding ecology of the Great Basin Rattlesnake ( Crotalus lutosus , Viperidae)  

Microsoft Academic Search

Documenting variation in organismal traits is essential to understanding the ecology of natural populations. We relied on stomach contents of preserved specimens and literature records to assess ontogenetic, intersexual, temporal, and geographic variations in the feeding ecology of the North American Great Basin Rattlesnake (Crotalus lutosus Klauber, 1930). Snakes preyed mainly on rodents, occasionally on lizards, and less frequently on

Xavier Glaudas; Tereza Jezkova; Javier A. Rodríguez-Robles

2008-01-01

77

Mitochondrial genome of Protobothrops jerdonii (Squamata: Viperidae: Crotalinae).  

PubMed

Protobothrops jerdonii is a common venomous snake that is widely distributed in southwestern China and other adjacent countries of Asia. In this study, the complete mitochondrial genome of P. jerdonii was determined. The circle genome with the 17,239 bp total length contained 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 2 control regions. Overall base composition of the complete mtDNA was 33.13% A, 25.07% T, 29.31% C, and 12.50% G. All the genes in P. jerdonii were distributed on the H-strand, except for the ND6 subunit gene and eight tRNA genes which were encoded on the L-strand. PMID:23316752

Huang, Xin; Zhang, Liang; Zhu, Xiaoxue; Pan, Tao; Wang, Hui; Zhang, Baowei

2013-01-14

78

Etude CCD de 11 variables suspectes du Serpent  

NASA Astrophysics Data System (ADS)

Hervé Chantegros has studied 11 stars in Serpens, suspected, long ago by Antoine Brun to be variable. Those stars were followed from April 24 to October 4, with a CCD. The results are given here, some of those stars seem to vary up to 1.5 mag large (possibly seen visually). Those stars need more study from amateurs to be classified.

Chantegros, Hervé

2005-12-01

79

The rod and the serpent: history's ultimate healing symbol.  

PubMed

The snake has served as a medical emblem for more than 2400 years, since its association with the ancient Greek god of medicine and healing, Asclepius, in the 4th century BC. Its symbolic background can be traced further back to the worship of gods of earth's blossom in ancient Egypt and earth-related deities of the archaic period of Greek antiquity. It is featured entwined around a staff of knowledge and wisdom in most anaglyphs depicting Asclepius. The snake was impressed in the Old and the New Testament as well as in the Christian tradition as a symbol of sin, rejuvenation, death, resurrection, asthenia, and therapy. It is postulated that the double-snake motif was reintroduced by Renaissance philosophers as a medical emblem due to the symbolic connections of Hermes with deliverance and redemption. However, its use during the last two centuries seems to lack substantial historical background. The historical, mythological, and traditional retrospection of the snake's symbolism validates its appropriateness in the health-care field. PMID:20556606

Antoniou, Stavros A; Antoniou, George A; Learney, Robert; Granderath, Frank A; Antoniou, Athanasios I

2011-01-01

80

Serpentized mantle at rifted margins: The Goban Spur example  

NASA Astrophysics Data System (ADS)

The crustal structure of rifted continental margins can tell us about the processes that operated from continental extension to eventual break-up and sea floor spreading. Variations between margins may record different processes operating during extension or indicate changes in the external geological controls such as mantle plume influence. Extension between Europe and North America began in the mid Cretaceous, dated at the Goban Spur-Flemish Cap rift as late Hauterivian-early Barremian (126-128 Ma) from deep sea drilling (DSDP leg 80) results on the Goban Spur margin. Marine magnetic anomaly 34 can be identified clearly on both margins and indicates that sea floor spreading began no later than 83 Ma. Syn-rift volcanism is limited to a 20 km basaltic body, with considerable lateral extent, at the foot of the continental slope, emplaced at the end of continental rifting. \

Bullock, A. D.; Minshull, T. A.

2002-12-01

81

Serpentized mantle at rifted margins: The Goban Spur example  

Microsoft Academic Search

The crustal structure of rifted continental margins can tell us about the processes that operated from continental extension to eventual break-up and sea floor spreading. Variations between margins may record different processes operating during extension or indicate changes in the external geological controls such as mantle plume influence. Extension between Europe and North America began in the mid Cretaceous, dated

A. D. Bullock; T. A. Minshull

2002-01-01

82

Pharmacological characterization of mouse hind paw oedema induced by Bothrops insularis (jararaca ilhoa) snake venom  

Microsoft Academic Search

Bothrops snake venoms produce marked local effects, including oedema, haemorrhage and necrosis. The ability of Bothrops insularis venom to induce oedema in mice was investigated. Venom was injected into hind paws and the change in volume over time was measured by plethysmometry. B. insularis venom (0.01–2.5 ?g\\/paw) induced paw oedema which, at high doses (?0.5 ?g\\/paw), was accompanied by haemorrhage.

Ana M Barbosa; Renata O do Amaral; Catarina F. P Teixeira; Stephen Hyslop; José C Cogo

2003-01-01

83

Sperm storage in males of the snake Crotalus durissus terrificus (Crotalinae: Viperidae) in southeastern Brazil.  

PubMed

Seasonal variations in spermatozoa numbers and in sperm motility along the vas deferens in Crotalus durissus terrificus from southeastern Brazil were analyzed. Our data demonstrate storage and motility of the spermatozoa along the vas deferens throughout the year. This is characteristic of a postnuptial reproductive cycle, usually found in snakes living in temperate climates. We describe similarities in reproductive cycle patterns found in the tropical nonhibernator C. durissus terrificus and in hibernator snakes from temperate zones. Our results show that in C. durissus terrificus, a significant difference in spermatozoa counts occurs between winter and summer. Higher numbers of spermatozoa in summer and autumn, due to intense spermiogenesis, coincides with the mating season in autumn. These data indicate that after spermiogenesis in summer, the males combine the peak of sperm storage to the period females are attractive. Mating, however, is not linked to ovulation, and the sperm is stored in the females during winter until fertilization occurs in spring. In the males, after mating, spermatozoon counts low. In spring, they gradually increase, turning again the highest in summer and autumn. During spermiogenesis in the convoluted vas deferens, spermatozoa gain motility, enhancing their performance along their way towards the distal portion. PMID:15528165

Almeida-Santos, Selma M; Laporta-Ferreira, Iara L; Antoniazzi, Marta M; Jared, Carlos

2004-10-01

84

Molecular phylogeography of endangered sharp-snouted pitviper (Deinagkistrodon acutus; Reptilia, Viperidae) in Mainland China.  

PubMed

Using phylogenetic and population genetic approaches, the present study reports the phylogeographic structure of the sharp-snouted pitviper (Deinagkistrodon acutus), a threatened snake species with commercial and medicinal importance in China. The entire mitochondrial ND2 gene (NADH dehydrogenase subunit 2) sequences of 86 individuals of D. acutus from 14 localities across its range in China were determined. Based on the results of phylogenetic analyses, distribution of diagnostic sites, haplotype network, and AMOVA hierarchical analysis, an east-west division of the whole D. acutus population could be observed. Geographically, a line formed by a lake, river, and mountain chain (the Poyang Lake, Gan River to the southern end of the Wuyi Mountains), results in vicariance and approximately vertically splits the range into two and the whole population into two main lineages (western and eastern). The bifurcating tree suggested generally west to east dispersal trend. The data fit the isolation by distance (IBD) model well. Star-like clusters in haplotype network, significantly negative values of Fs statistics, and unimodal mismatch distributions all suggest recent demographic expansions in four areas. The results show that isolation, dispersal, bottleneck, and expansion jointly constitute the history of D. acutus. In a haplotype network, the excessive predominance of central haplotypes, few medium-frequency haplotypes, predominance (73.1%) of the singletons among the derived haplotypes, most of which are connected to the central haplotype by only one mutational step, unsymmetrical campanulate unimodal curve of mismatch distributions and leftwards shift of the peaks, all suggest that the whole D. acutus population is a young population with low genetic diversity. Based on the data, the first priority for conservation action should be given to the Huangshan unit. PMID:17643319

Huang, Song; He, Shunping; Peng, Zuogang; Zhao, Kai; Zhao, Ermi

2007-06-09

85

Evolutionary Relationships among the True Vipers (Reptilia: Viperidae) Inferred from Mitochondrial DNA Sequences  

Microsoft Academic Search

Nucleotide sequences of mitochondrial cytochrome b and 16S rRNA genes, totaling 946 bp, were used to reconstruct a molecular phylogeny of 42 species of the subfamily Viperinae representing 12 of the 13 recognized genera. Maximum-parsimony and maximum-likelihood were used as methods for phylogeny reconstruction with and without a posteriori weighting. When representatives of the Causinae were taken as outgroup, five

Peter Lenk; Svetlana Kalyabina; Michael Wink; Ulrich Joger

2001-01-01

86

The in vitro toxicity of venoms from South Asian Hump-nosed pit vipers (Viperidae: Hypnale)  

PubMed Central

Hump-nosed pit vipers (Genus Hypnale) are venomous snakes from South India and Sri Lanka. Envenoming by Hypnale species may cause significant morbidity and is characterized by local envenoming and less commonly coagulopathy and acute renal failure. Currently there are three nominal species of this genus: H. hypnale, H. zara and H. nepa. This study investigates the biochemical and pharmacological properties of the venoms from the three Hypnale species in Sri Lanka. The three Hypnale venoms had similar chromatographic profiles using reverse phase high performance liquid chromatography and fractions with procoagulant activity were identified. Hypnale venoms had potent cytotoxicity in cultured rat aorta smooth muscle cells with similar IC50 values. The venoms had weak neurotoxic and myotoxic activity in the isolated chick biventer muscle preparation. They had mild procoagulant activity with close MCC5 values and also phospholipase activity. Locally available polyvalent antivenom did not neutralise any venom effects. The study demonstrates that the three Hypnale venoms are similar and cytotoxicity appears to be the most potent effect, although they have mild procoagulant activity. These findings are consistent with clinical reports.

Maduwage, Kalana; Hodgson, Wayne C; Konstantakopoulos, Nicki; O'Leary, Margaret A; Gawarammana, Indika; Isbister, Geoffrey K

2011-01-01

87

Wound Myiasis due to Musca domestica (Diptera: Muscidae) in Persian Horned Viper, Pseudocerastes persicus (Squamata: Viperidae)  

PubMed Central

A case of myiasis due to Musca domestica describes in Pseudocerastes persicus for the first time. The snake was found in Bari Karafs, Kashan, Iran, with a lesion on its body. Fourteen live larvae of M. domestica removed from its wound. This is the first report of a new larval habitat of M. domestica.

Dehghani, R; Sedaghat, MM; Bidgoli, M Sabahi

2012-01-01

88

Crystallographic characterization of functional sites of crotoxin and ammodytoxin, potent ?-neurotoxins from Viperidae venom.  

PubMed

This review will focus on a description of the three-dimensional structures of two ?-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 anticoagulant properties. Comparative structural analysis of these two PLA(2) isoforms, which differ only by two amino acid residues, allowed us to detect local conformational changes and delineate the role of critical residues in the anticoagulant and neurotoxic functions of these PLA(2) (Saul et al., 2010). We have also determined, at 1.35Å resolution, the crystal structure of heterodimeric crotoxin (Faure et al., 2011). The three-dimensional structure of crotoxin revealed details of the binding interface between its acidic (CA) and basic (CB) subunits and allowed us to identify key residues involved in the stability and toxicity of this potent heterodimeric ?-neurotoxin (Faure et al., 2011). The precise spatial orientation of the three covalently linked polypeptide chains in the mature CA subunit complexed with CB helps us to understand the role played by critical residues of the CA subunit in the increased toxicity of the crotoxin complex. Since the CA subunit is a natural inhibitor of the catalytic and anticoagulant activities of CB, identification of the CA-CB binding interface describes residues involved in this inhibition. We propose future research directions based on knowledge of the recently reported 3D structures of crotoxin and ammodytoxin. PMID:22683534

Faure, Grazyna; Saul, Frederick

2012-06-07

89

Tissue distribution in mice of BPP 10c, a potent proline-rich anti-hypertensive peptide of Bothrops jararaca.  

PubMed

The snake venom proline-rich peptide BPP 10c is an active somatic angiotensin-converting enzyme (sACE) inhibitors. Recently we demonstrated that the anti-hypertensive effect of BPP 10c is not related to the inhibition of sACE alone, thus suggesting that this enzyme is not its only target for blood pressure reduction. In the present work, a biodistribution study in Swiss mice of [(125)I]-BPP 10c in the absence or in the presence of a saturating concentration of captopril, a selective active-site inhibitor of sACE, demonstrated that: (1) [(125)I]-BPP 10c was present in several organs and the renal absorption was significantly high; (2) [(125)I]-BPP 10c showed a clear preference for the kidney, maintaining a high concentration in this organ in the presence of captopril for at least 3h; (3) The residual amount of [(125)I]-BPP 10c in the kidney of animals simultaneously treated with captopril suggest that the peptide can interact with other targets different from sACE in this organ. We also showed that Cy3-labeled BPP 10c was internalized by human embryonic kidney cells (HEK-293T). Taken together, these results suggest that sACE inhibition by captopril affects the tissue distribution of [(125)I]-BPP 10c and that the anti-hypertensive effects of BPP 10c are not only dependent on sACE inhibition. PMID:18160089

Silva, Carlos A; Portaro, Fernanda C V; Fernandes, Beatriz L; Ianzer, Danielle A; Guerreiro, Juliano R; Gomes, Claudiana L; Konno, Katsuhiro; Serrano, Solange M T; Nascimento, Nanci; Camargo, Antonio C M

2007-11-17

90

Phylogenetic conservation of a snake venom metalloproteinase epitope recognized by a monoclonal antibody that neutralizes hemorrhagic activity.  

PubMed

Snake venom metalloproteinases (SVMPs) are present in large quantities in venoms of viper snakes and also in some elapids. Jararhagin is a representative of a P-III multidomain hemorrhagic SVMP present in Bothrops jararaca venom. It is comprised of a catalytic, a disintegrin-like and a cysteine-rich domain. Seven anti-jararhagin monoclonal antibodies (MAJar 1-7) were produced, of which six reacted with the disintegrin domain. MAJar 3 recognized an epitope present at the C-terminal part of the disintegrin-like domain, and neutralized jararhagin-induced hemorrhage. In this study, we evaluated the reactivity of these monoclonal antibodies with venoms from 27 species of snakes belonging to different families. MAJar 3 recognized most of the hemorrhagic venoms. By ELISA, MAJar 3 reacted strongly with venoms from Viperidae family and weakly with Colubridae and Elapidae venoms. This recognition pattern was due to bands between 50 and 80 kDa, corresponding to P-III SVMPs. This antibody preferentially neutralized the hemorrhage induced by venoms of Bothrops snakes. This fact suggests that the epitope recognized by MAJar 3 is present in other metalloproteinases throughout snake phylogeny. However, slight structural differences in the epitope may result in insufficient affinity for neutralization of biological activities. PMID:14757213

Tanjoni, Isabelle; Butera, Diego; Spencer, Patrick J; Takehara, Harumi A; Fernandes, Irene; Moura-da-Silva, Ana Maria

2003-12-01

91

Rattlesnakes in the Garden: The Fascinating Serpents of the Early, Edenic Republic  

Microsoft Academic Search

:This essay considers the various ways in which writers and visual artists deployed the rattlesnake to advance and, later, destabilize nationalist agendas between the French and Indian War and the Civil War. During the intervening century the rattlesnake, with its powers of fascination, evolved into a multifaceted symbol used to represent a wide range of ideas: British colonial unity; American

Zachary McLeod Hutchins

2011-01-01

92

Rattlesnakes in the Garden: The Fascinating Serpents of the Early, Edenic Republic  

Microsoft Academic Search

This essay considers the various ways in which writers and visual artists deployed the rattlesnake to advance and, later, destabilize nationalist agendas between the French and Indian War and the Civil War. During the intervening century the rattlesnake, with its powers of fascination, evolved into a multifaceted symbol used to represent a wide range of ideas: British colonial unity; American

Zachary McLeod Hutchins

2011-01-01

93

A phylogenetic analysis of Pseudonaja (Hydrophiinae, Elapidae, Serpentes) based on mitochondrial DNA sequences.  

PubMed

A phylogenetic analysis of mitochondrial ND4 and adjacent tRNA sequences for a geographically extensive series of specimens reveals nine major clades within Pseudonaja, of which six are largely coincident with nominal taxa (P. affinis, P. guttata, P. inframacula, P. ingrami, P. modesta, and P. textilis). The remaining three clades are composed of specimens presently referred to P. nuchalis. Two of these clades correspond with the "Darwin" and "Southern" morphs of previous authors, while the third clade incorporates the "Orange with black head" and "Pale head, grey nape" morphs. We are unable to confirm the presence of consistent karyotypic differences between "Orange with black head" and "Pale head, grey nape" specimens, however, P. inframacula, P. textilis, and P. nuchalis "Darwin" are found to exhibit distinctive karyotypes, as previously reported. These results, in conjunction with additional observations of karyotpic and morphological variation, are consistent with nine historically-independent lineages (i.e., species) within Pseudonaja. There is strong support for a clade composed of P. affinis, P. inframacula, P. ingrami, P. textilis, and the three P. nuchalis lineages, and for the relationships (P. inframacula, P. nuchalis "Southern") and (P. nuchalis "Darwin", P. nuchalis "Orange with black head"--"Pale head, grey nape" ). PMID:16098768

Skinner, Adam; Donnellan, Stephen C; Hutchinson, Mark N; Hutchinson, Rhonda G

2005-08-10

94

Preliminary Results From the Serpentinite, Extension and Regional Porosity Experiment Across the Nicaraguan Trench (SERPENT)  

NASA Astrophysics Data System (ADS)

Water plays an important role in the volcanic processes occurring at convergent margins, as the release of water from the downgoing slab affects the rheology of the mantle, increases melting by lowering the solidus temperature, and alters the chemistry of arc-lavas. Yet, one of the major uncertainties in terms of fluid inputs into the subduction factory concerns the extent of serpentinization of the oceanic upper mantle and the volumes of water that are being carried into the subduction system through this route. In April 2010 we conducted a large-scale marine electromagnetic experiment along a 300 km profile offshore Nicaragua in a region that shows evidence for substantial fault related fluid circulation in the crust and possibly upper mantle, and high Ba/La ratios and water contents in adjacent onshore volcanics that suggest a strong slab fluid input into the arc-melting. Our project is the largest combined controlled-source electromagnetic (CSEM) and magnetotelluric (MT) data set ever collected on an active subduction zone. During the single 28 day research cruise aboard the R/V Melville we collected 54 stations of broadband marine magnetotelluric (MT) data and deep-towed nearly 800 km of controlled-source electromagnetic (CSEM) data. Robust multiple-station array processing of the MT data yields high quality MT responses from 10 to 20,000 s period. The MT responses are fairly 1D over the abyssal plain, showing the effects of a thin veneer of conductive sediments overlying a resistive lithosphere and a deeper conductive mantle. The responses become strongly 2D on the trench outer rise and exhibit large 3D distortions at the bottom of the trench, likely due to a combination of effects from severe topography and seafloor conductivity variations. Two circular CSEM tows of 30 km radius were measured by special long-wire EM (LEM) sensors on the abyssal plain and the outer rise. The LEM data reveals a distinct pattern of electromagnetic polarization that is characteristic of mantle transverse anisotropy. Since the conductive axis is aligned with the fossil ridge-parallel direction and reactivated normal faults in the trench, we interpret this to be caused by conductive serpentinized mantle penetrating faults. Conventional CSEM data recorded at a broad suite of transmission frequencies along the 300 km long profile and a 50 km along strike profile provide constraints on crustal conductivity variations. The analysis of these data is ongoing and will provide a comprehensive picture of the electrical conductivity structure from the seafloor to the upper mantle, representing the entire input into this part of the Central American subduction system. Since conductivity is highly dependent on thermal structure, crack porosity and the presence of serpentinite, our experiment will provide constraints on the depth of active fluid circulation within the oceanic crust and mantle, the variation of fluid circulation with distance from the trench and hence with the degree of plate bending, and the extent of dewatering of the subducting slab in the shallow portion of the mantle wedge.

Key, K. W.; Constable, S.; Evans, R. L.; Naif, S.; Matsuno, T.; Lizarralde, D.

2010-12-01

95

Phylogenetic position, origin and biogeography of Palearctic and Socotran blind-snakes (Serpentes: Typhlopidae).  

PubMed

The majority of the family Typhlopidae occurs in the Neotropic, Australasian, Indo-Malayan and Afrotropic ecoregions. They show a restricted distribution in the western Palearctic, where they include few native species, i.e. Rhinotyphlops simoni, R. episcopus and Typhlops vermicularis. A unique species among typhlopids is T. socotranus, found in Socotra, one of the most endemic-rich archipelagoes. In this study we determine the phylogenetic position of the above mentioned species and discuss their systematics, origin and biogeography. For this purpose we use three protein-coding nuclear markers (AMEL-amelogenin, BDNF-brain-derived neurotrophic factor and NT3-neurotrophin 3) to construct a time-calibrated phylogeny of the family Typhlopidae. Our results show that T. socotranus is a sister-species to T. vermicularis, while R. simoni and R. episcopus are sister-species to each other and are found within the African clade of the family, although they are geographically distributed in west Asia. Additionally we discuss several hypotheses on their origin, as well as the occurence of typhlopids in Eurasia. PMID:23523862

Kornilios, P; Giokas, S; Lymberakis, P; Sindaco, R

2013-03-21

96

Serpents in the Garden: English Professors in Contemporary Film and Television  

ERIC Educational Resources Information Center

|In an article on "Smart People" (2008), a film in which Dennis Quaid plays an English professor who becomes romantically involved with a former student, Jeffery J. Williams notes that a "common complaint among academics is that films don't depict them correctly, and in some ways Quaid was accoutered by central casting, beginning the movie in a…

Carens, Timothy L.

2010-01-01

97

The Malicious SerpentSnakes as a Prototypical Stimulus for an Evolved Module of Fear  

Microsoft Academic Search

As reptiles, snakes may have signified deadly threats in the environment of early mammals. We review findings suggesting that snakes remain special stimuli for humans. Intense snake fear is prevalent in both humans and other primates. Humans and monkeys learn snake fear more easily than fear of most other stimuli through direct or vicarious conditioning. Neither the elicitation nor the

Arne Öhman; Susan Mineka

2003-01-01

98

Feeding in Atractaspis (Serpentes: Atractaspididae): a study in conflicting functional constraints.  

PubMed

African fossorial colubroid snakes of the genus Atractaspis have relatively long fangs on short maxillae, a gap separating the pterygoid and palatine bones, a toothless pterygoid, and a snout tightly attached to the rest of the skull. They envenomate prey with a unilateral backward stab of one fang projected from a closed mouth. We combined structural reanalysis of the feeding apparatus, video records of prey envenomation and transport, and manipulations of live and dead Atractaspis to determine how structure relates to function in this unusual genus of snakes. Unilateral fang use in Atractaspis is similar to unilateral slashing envenomation by some rear-fanged snakes, but Atractaspis show no maxillary movement during prey transport. Loss of pterygoid teeth and maxillary movement during transport resulted in the inability to perform. 'pterygoid walk' prey transport. Atractaspis transport prey through the oral cavity using movement cycles in which mandibular adduction, anterior trunk compression, and ventral flexion of the head alternate with mandibular abduction and extension of head and anterior trunk over the prey. Inefficiencies in manipulation and early transport of prey are offset by adaptability of the envenomating system to various prey types in both enclosed and open spaces and by selection of prey that occupy burrows or tunnels in soil. Atractaspis appears to represent the evolutionary endpoint of a functional conflict between envenomation and transport in which a rear-fanged envenomating system has been optimized at the expense of most, if not all, palatomaxillary transport function. PMID:16351890

Deufel, Alexandra; Cundall, David

2003-01-01

99

Gray's constant and 'swiss cheese' and 'sea serpents' in stellar convection zones  

NASA Astrophysics Data System (ADS)

Gray (1985), on the basis of Zeeman broadening measurements on a sample of G and K darfs found an interesting relation between the average magnetic field strength, B, and the areal coverage factor, A0: the product A0B is a constant independent of spectral type and rotational velocity. Pidatella and Stix (1986) applied a non-local form of the mixing length theory to the lower part of the solar convection zone to estimate the size of the overshoot layer and computed the magnetic field strength beyond which thin toroidal flux tubes, located in the overshoot layer, become unstable. In the present work the authors extend the calculations of Pidatella and Stix (1986) to a number of main sequence spectral types, ranging from F5 to K0. A possible explanation of why the Sun does not fit Gray's law is also proposed.

Belvedere, G.; Pidatella, R. M.; Stix, M.

1987-05-01

100

DISCOVERY OF THE MADAGASCAR SERPENT-EAGLE, EUTRIORCHIS ASTUR, IN CENTRAL AND SOUTHEASTERN MADAGASCAR. (U915543)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

101

When colour patterns reflect phylogeography: new species of Dasypeltis (Serpentes: Colubridae: Boigini) from West Africa.  

PubMed

Six colour phases are currently known in the genus Dasypeltis in West Africa, three in the D. scabra complex and three in the D. fasciata complex. Molecular phylogenetic analysis reveals that all correspond to distinct species. D. parascabra sp. nov. is described from wet savannah areas of Guinea and Ivory Coast. D. latericia is given full specific rank. The validity of D. sahelensis, D. gansi and D. confusa - three species recently described on the basis of colour pattern and biogeography - is confirmed. D. fasciata is confined to rain forest areas of West and Central Africa. D. scabra is absent from West Africa. PMID:22847016

Trape, Sébastien; Mediannikov, Oleg; Trape, Jean-François

2012-06-26

102

Serpents in the Garden: English Professors in Contemporary Film and Television  

ERIC Educational Resources Information Center

In an article on "Smart People" (2008), a film in which Dennis Quaid plays an English professor who becomes romantically involved with a former student, Jeffery J. Williams notes that a "common complaint among academics is that films don't depict them correctly, and in some ways Quaid was accoutered by central casting, beginning the movie in a…

Carens, Timothy L.

2010-01-01

103

Aquatic and terrestrial locomotor speeds of amphibious sea-snakes (Serpentes, Laticaudidae)  

Microsoft Academic Search

Amphibious animals may be subject to strong but conflicting selective pressures to enhance locomotor performance both on land and in the water. Biomechanical models suggest that in snakes, adaptations to swimming (e.g. reduction of ventral plates, flattening of tail) will reduce their ability to move on land. The locomotor speeds of six taxa of amphibious (laticaudid) sea-snakes, plus one entirely

Richard Shine; Harold G. Cogger; Robert R. Reed; Sohan Shetty; Xavier Bonnet

2003-01-01

104

Dissecting the major American snake radiation: A molecular phylogeny of the Dipsadidae Bonaparte (Serpentes, Caenophidia)  

Microsoft Academic Search

The Dipsadidae contains more than 700 extant species belonging to 92 genera and is the largest family of American snakes. In this work, we built a data set including two mitochondrial genes (12S and 16S rRNA) for 125 dipsadid taxa belonging to 59 genera, in order to gain further insights on the phylogenetic relationships of this large group at the subfamilial and generic levels.

Nicolas Vidal; Maël Dewynter; David J. Gower

2010-01-01

105

Dissecting the major American snake radiation: A molecular phylogeny of the Dipsadidae Bonaparte (Serpentes, Caenophidia).  

PubMed

The Dipsadidae contains more than 700 extant species belonging to 92 genera and is the largest family of American snakes. In this work, we built a data set including two mitochondrial genes (12S and 16S rRNA) for 125 dipsadid taxa belonging to 59 genera, in order to gain further insights on the phylogenetic relationships of this large group at the subfamilial and generic levels. Among dipsadines, the monotypic genus Nothopsis is the sister-group to Leptodeira. Among xenodontines, the monophyly of seven previously recognized tribes (Alsophiini, Elapomorphini, Hydropsini, Philodryadini, Pseudoboini, Tachymenini and Xenodontini) is confirmed. Among Xenodontini, the genus Liophis is paraphyletic with respect to Erythrolamprus and Umbrivaga and workers should be aware of the inadequacy of the current taxonomy. Finally, the following genera could not confidently be allocated to the above tribes: Caaeteboia, Echinantera and Taeniophallus, Tropidodryas, Manolepis and Pseudalsophis, Xenopholis, Psomophis, Hydrodynastes, Conophis and Crisantophis. PMID:20176336

Vidal, Nicolas; Dewynter, Maël; Gower, David J

2010-01-22

106

The Serpent in the Garden State: Juvenile Delinquency in 1920s New Jersey  

ERIC Educational Resources Information Center

|School administrators, educators, psychologists, social workers, the juvenile courts, institutional reformers, and others shape the manner in which children are labeled, portrayed, and treated. However, the agendas, motivations, political language, and influence of these "helping professionals" in "treating" and "reforming" juvenile delinquents…

Ferry, Thomas M.

2010-01-01

107

Kleptothermy: an additional category of thermoregulation, and a possible example in sea kraits (Laticauda laticaudata, Serpentes)  

PubMed Central

Lacking the capacity for thermogenesis, most ectotherms inhabiting thermally heterogeneous environments rely instead upon exploiting that ambient heterogeneity. In many cases they maintain body temperatures within a narrow range despite massive spatial and temporal variation in ambient conditions. Reliance on diverse thermal opportunities is reflected in specific terms for organisms that bask in sunlight to regulate their temperature (heliotherms), or that press their bodies against warm substrates to facilitate heat flow (thigmotherms), or that rely on large body mass to maintain thermal constancy (gigantothermy). We propose an additional category of thermoregulators: kleptotherms, which regulate their own temperature by ‘stealing’ heat from other organisms. This concept involves two major conditions: the thermal heterogeneity created by the presence of a warm organism in a cool environment and the selective use of that heterogeneity by another animal to maintain body temperatures at higher (and more stable) levels than would be possible elsewhere in the local area. Kleptothermy occurs in endotherms also, but is usually reciprocal (rather than unilateral as in ectotherms). Thermal monitoring on a small tropical island documents a possible example of kleptothermy, based on high stable temperatures of a sea snake (Laticauda laticaudata) inside a burrow occupied by seabirds.

Brischoux, Francois; Bonnet, Xavier; Shine, Richard

2009-01-01

108

Neogene diversification and taxonomic stability in the snake tribe Lampropeltini (Serpentes: Colubridae)  

Microsoft Academic Search

The impact of climate change during the Pleistocene on organ- isms living in temperate areas of the world has been documented for more than fifty years (Rand, 1948). A major impact of Pleisto- cene glacial cycles on vertebrates in temperate zones is hypothe- sized to be the isolation of species into allopatric populations (Avise and Walker, 1998). Refugial isolation and

R. Alexander Pyron; Frank T. Burbrink

2009-01-01

109

Enlarged Posterior Maxillary Teeth in the Scarlet Snake, Cemophora coccinea (Serpentes: Colubridae), Using Scanning Electron Microscopy  

Microsoft Academic Search

The scarlet snake, Cemophoracoccinea,is a small-to-medi- um sized colubrid species that is distributed throughout Arkansasand the southeastern United States (Conant and Collins, 1991). The species is noted for its coloration (a red, black, and yellow-to-creambanding pattern), fossori- al-to-semi-fossorial habits, and distinctively pointed snout. The scarlet snake is also infrequently encountered, and little is known about its biology in Arkansas other

Stanley E. Trauth

110

Heart of a Serpent? The Cold War Science Fiction of Murray Leinster  

Microsoft Academic Search

This article argues that the Cold War science fiction of Murray Leinster has been either mischaracterized or unfortunately ignored. Starting with the Soviet writer Ivan Efremov’s attack on Leinster’s 1945 story “First Contact,” his postwar work has too often been depicted as paranoid, cartoon-like, and war exalting. Instead, with a few exceptions, he was a consistent voice for peaceful coexistence

Thomas M. Barrett

2012-01-01

111

The phylogenetic position of Anomochilidae (Reptilia: Serpentes): first evidence from DNA sequences  

Microsoft Academic Search

Previously, anilioids (Aniliidae, Anomochilidae, Cylindrophiidae and Uropeltidae) were considered the only extant, non-macrostomatan alethinophidian snakes. Although their monophyly and intrarelationships remained poorly established, their fossoriality, small gape, and inferred phylogenetic position have been important evidence in orthodox scenarios about early snake evolution. Recent molecular studies including aniliids, cylindrophiids and uropeltids indicate anilioid polyphyly, with the latter two families comprising a

D. J. Gower; N. Vidal; J. N. Spinks; C. J. McCarthy

2005-01-01

112

The Rod and the Serpent: History’s Ultimate Healing Symbol  

Microsoft Academic Search

The snake has served as a medical emblem for more than 2400 years, since its association with the ancient Greek god of medicine\\u000a and healing, Asclepius, in the 4th century BC. Its symbolic background can be traced further back to the worship of gods of\\u000a earth’s blossom in ancient Egypt and earth-related deities of the archaic period of Greek antiquity. It

Stavros A. Antoniou; George A. Antoniou; Robert Learney; Frank A. Granderath; Athanasios I. Antoniou

2011-01-01

113

Close karyological kinship between the reptilian suborder serpentes and the class aves  

Microsoft Academic Search

In contrast to the situation found in two classes of warm-blooded vertebrates, mammals and birds, the class Reptilia is not uniform with regard to total genetic content; rather, it contains two distinct categories. The close cytological kinship between snakes and birds was revealed. Both are almost identical in total genetic content, which is about 50 per cent that of placental

Willy Beçak; Maria Luiza Beçak; H. R. S. Nazareth; Susumu Ohno

1964-01-01

114

Opossums (Mammalia: Didelphidae) in the diets of Neotropical pitvipers (Serpentes: Crotalinae): evidence for alternative coevolutionary outcomes?  

PubMed

Opossums and pitvipers are sympatric throughout most of the New World, but trophic relationships between these speciose clades have only recently attracted the attention of researchers. Although it is now known that some venom-resistant opossums prey on pitvipers, a review of the literature on diets shows that some Neotropical pitvipers prey on opossums. Interestingly, some pitviper species prey on opossums known or suspected to be venom resistant. If venom resistance and venom potency are coevolved traits, then these observations suggest that alternative outcomes may result in role-switching between victims and exploiters. Because molecular antagonists (e.g., venom toxins and toxin-neutralizing serum proteins) that could mediate such outcomes have been plausibly identified, this system is a potentially fruitful field for evolutionary research. PMID:23402839

Voss, Robert S

2013-02-08

115

Mitochondrial DNA-Based Phylogeography of North American Rubber Boas, Charina bottae (Serpentes: Boidae)  

Microsoft Academic Search

We used 783 bp of mitochondrial DNA sequences to study the phylogeography of Charina bottae (rubber boa) in western North America, with an emphasis on populations from California (U.S.A.). Maximum-parsimony and maximum-likelihood methods identified a basal divergence within C. bottae that corresponds to southern and northern segments of its current distribution. These clades coincide with the ranges of the two

Javier A Rodr??guez-Robles; Glenn R. Stewart; Theodore J. Papenfuss

2001-01-01

116

Comparative in-vivo toxicity of venoms from South Asian hump-nosed pit vipers (Viperidae: Crotalinae: Hypnale)  

PubMed Central

Background Envenoming by south Asian hump-nosed pit vipers (Genus: Hypnale) is a significant health issue in Sri Lanka and in peninsular India. Bites by these snakes frequently lead to local envenoming, coagulopathy and acute renal failure even resulting in death. Recently the genus was revised and the existence of three species viz H. hypnale, H. nepa and H. zara were recognized. There is, however, a paucity of information on the toxicity of the venoms of these species. Hence, we compared the toxic effects of the three Hypnale venoms using BALB/c mice. Findings Intraperitoneal median lethal doses (LD50) for H. hypnale, H. zara and H. nepa venoms were 1.6, 6.0 and 9.5??g protein/g respectively. Minimum haemorrhagic doses for venoms of H. hypnale, H. zara and H. nepa were 3.4, 11.0 and 16.6??g protein/mouse respectively. The minimum necrotic doses for the same venoms were 15.0, 55.1 and 68.2??g protein/mouse respectively. Severe congestion and petecheal haemorrhages were observed in lungs, kidneys, liver and the alimentary tract. Histopathogical examination of kidneys revealed proximal tubular cell injury and acute tubular necrosis with intact basement membrane indicating possible direct nephrotoxicity. Hypnale venoms caused pulmonary oedema, hepatocellular degeneration and necrosis, focal neuronal degeneration in brain and extramedullary haemopoiesis in spleen. H. hypnale venom caused all above histopathological alterations at lower doses compared to the other two. Conclusion Hypnale venoms cause similar pathological changes with marked differences in the severity of the toxic effects in vivo. Therefore, differences in the severity of the clinical manifestations could possibly be seen among bite victims of the three Hypnale species.

2012-01-01

117

A relict lineage and new species of green palm-pitviper (Squamata, Viperidae, Bothriechis) from the Chortís Highlands of Mesoamerica.  

PubMed

A new species of palm-pitviper of the genus Bothriechis is described from Refugio de Vida Silvestre Texíguat in northern Honduras. The new species differs from congeners by having 19 dorsal scale rows at midbody, a bright green dorsal coloration in adults, the prelacunal scale fused to the second supralabial, and in representing a northern lineage that is sister to Bothriechis lateralis, which is distributed in Costa Rica and western Panama and is isolated from the new taxon by the Nicaraguan Depression. This represents the 15th endemic species occurring in Refugio de Vida Silvestre Texíguat, one of the richest herpetofaunal sites in Honduras, itself being the country with the highest degree of herpetofaunal endemism in Central America. We name this new species in honor of a Honduran conservationist slain in fighting against illegal logging, highlighting the sacrifices of rural activists in battling these issues and the critical importance of conservation in these areas. PMID:23794885

Townsend, Josiah H; Medina-Flores, Melissa; Wilson, Larry David; Jadin, Robert C; Austin, James D

2013-05-13

118

Edema induced by Bothrops asper (Squamata: Viperidae) snake venom and its inhibition by Costa Rican plant extracts  

Microsoft Academic Search

W e tested the capacity of leaf (Urera baccifera, Loasa speciosa, Urtica leptuphylla, Chaptalia nutans, and Satureja viminea) and root (Uncaria tomentosa) extracts to inhibit edema induced by Bothrops asper snake venom. Edema-forming activity was studied plethysmographically in the rat hind paw model. Groups of rats were injected intraperitoneally with various doses of each extract and, one hour later, venom

Beatriz Badilla; Fernando Chaves; Gerardo Mora; Luis J. Poveda

2006-01-01

119

Sexual activity and plasma levels of sex steroids in the aspic viper Vipera aspis L. (Reptilia, Viperidae).  

PubMed

Reproductive behavior and associated sexual activity was studied in individual male and female Vipera aspis over a 3-year period in western France in an attempt to correlate mating behavior with blood levels of gonadal sex steroids. Males had higher average levels of both testosterone (T) and 5 alpha-dihydrotestosterone (DHT) than females. Levels of progesterone (P) did not differ significantly between the two sexes but estradiol-17 beta (E2) concentrations were significantly higher in females during the season of mating. Spring mating behavior and copulation in males was associated with significantly increased levels of T and DHT, compared with postmating males; and a similar, but not significant trend, was evident with autumnal mating. The only statistically significant hormonal difference detected in males showing no sexual activity in autumn, was an elevated level of E2 at 0.52 +/- 0.20 ng/ml compared with 0.09 +/- 0.03 ng/ml in spring-breeding males (P = 0.05). Estrus in females is associated with increased levels of all four steroids but significant only for E2 and DHT. Levels of P were significantly reduced in females displaying seasonal anestrous in the spring immediately following reproduction. Females not displaying estrus in either spring or autumn had significantly lower plasma DHT and E2. Although mating behavior in males is associated statistically with elevated levels of T and DHT, a tight correlation is not obvious at the individual level, suggesting that increased concentrations of androgens are a necessary, but not sufficient, condition for mating. The data from V. aspis suggest that, as in a number of other reptilian species, high circulating levels of androgens function to "condition" or "organize" sexual behavior in males which may be displayed at some later time, well after actual levels have fallen, thus engendering the impression that reproductive behavior may be temporally dissociated from essential hormonal stimuli. PMID:8224772

Saint Girons, H; Bradshaw, S D; Bradshaw, F J

1993-09-01

120

Reproductive cycle of free-living male Saharan sand vipers, Cerastes vipera (Viperidae) in the Negev desert, Israel.  

PubMed

The Saharan sand viper, Cerastes vipera (Linnaeus, 1758), is distributed in all Saharan countries, being confined to sand and dune systems. This relatively small snake, up to 35 cm, is nocturnal, is active from spring to autumn (April to October) and hibernates during the winter (November to March). We predicted that C. vipera would have peak plasma testosterone concentration at mating and that the vas deferens would contain abundant spermatozoa at that time. To test our predictions, we collected information on the time of mating and measured monthly testosterone concentration, testes size and testicular activity in free-living male C. vipera during its active period from April to October. Mating occurred only during spring. The pattern of plasma testosterone concentration, testes volume, seminiferous tubule diameter and spermatogenesis all followed the general pattern of high values in autumn and spring and low values in early summer. Our predictions were partially supported. There was a high plasma testosterone concentration at mating in spring and the vas deferens contained abundant spermatozoa, as predicted, but there was also a high plasma testosterone concentration in autumn without mating. We concluded that: (1) males are both aestival in that they produce spermatozoa in autumn, which they store over the winter hibernation period, and vernal in that they produce spermatozoa in spring prior to mating; (2) matings are associated with spermatogenesis; and (3) the high plasma testosterone concentration is concomitant with both matings and spermatogenesis in spring and with spermatogenesis in autumn. We propose that C. vipera has a single peak of testicular activity and plasma testosterone concentration which start in autumn and end in spring. We also propose that spermatogenesis is prior to spring mating and, consequently, is prenuptial. PMID:22967959

Sivan, Jaim; Kam, Michael; Hadad, Shlomo; Allan Degen, A; Rozenboim, Israel; Rosenstrauch, Avi

2012-09-04

121

Gene expression of inflammatory mediators induced by jararhagin on endothelial cells.  

PubMed

Snake venom metalloproteinases (SVMP) are abundant toxins in venoms of viper snakes and play a relevant role in the complex and multifactorial tissue damage characteristic of Viperidae envenoming. Jararhagin, a SVMP isolated from Bothrops jararaca venom, induces a fast onset hemorrhagic lesions acting directly on the capillary vessels, which are disrupted by toxin adhesion and degradation of extracellular matrix proteins like collagen IV. Jararhagin also triggers inflammatory response, where endothelial cells are activated, resulting in the enhanced rolling of circulating leukocytes, nitric oxide generation, prostacyclin production and pro-inflammatory cytokines release. Jararhagin also decreases endothelial cells viability inducing apoptosis (in vitro studies). In the present study we attempted to correlate the effect of sub-apoptotic doses of jararhagin on human umbilical vein endothelial cells (HUVECs) and gene expression of pro-inflammatory mediators, using microarray assay, real time PCR and detection of specific proteins on HUVEC surface or released in the medium. Jararhagin was effective in activate and up-regulate the gene expression of different mediators such as E-selectin, VCAM-1, IL-8, CD69, Ang-2 and MMP-10. Despite the increase in expression of genes coding for such molecules, jararhagin did not induce increased concentrations of E-selectin, VCAM-1 and IL-8 produced or released by endothelial cells. In conclusion, jararhagin is able to activate pro-inflammatory gene transcription on endothelial cells however this stimulus is not sufficient to result in the consequent expression of pro-inflammatory effectors molecules like E-selectin, VCAM-1 and IL-8. The time courses of these events, as well as the doses of jararhagin are important points to be addressed herein. PMID:22960448

Lopes, Daiana S; Faquim-Mauro, Eliana; Magalhães, Geraldo S; Lima, Iara C; Baldo, Cristiani; Fox, Jay W; Moura-da-Silva, Ana Maria; Clissa, Patricia B

2012-08-07

122

Effects of Snake Venoms on Mammalian Cells in Tissue Culture.  

National Technical Information Service (NTIS)

The effects of snake venoms on two types of cells in tissue culture were investigated. Venoms of Crotalidae, Viperidae, Elapidae and Hydrophiidae, from widely separated geographical areas, were used. Venoms of the three Crotalidae and one Viperidae showed...

A. T. Tu R. B. Passey

1968-01-01

123

Maintaining Coral Snakes (Micrurus nigrocinctus, Serpentes: Elapidae) for venom production on an alternative fish-based diet.  

PubMed

American Elapid snakes (Coral Snakes) comprise the genera Leptomicrurus, Micruroides and Micrurus, which form a vast taxonomic assembly of 330 species distributed from the South of United States to the southern region of South America. In order to obtain venom for animal immunizations aimed at antivenom production, Coral Snakes must be kept in captivity and submitted periodically to venom extraction procedures. Thus, to maintain a snake colony in good health for this purpose, a complete alternative diet utilizing an easily obtained prey animal is desirable. The development of a diet based on fish is compared to the wild diet based on colubrid snakes, and assessed in terms of gain in body weight rate (g/week), longevity (weeks), venom yield (mg/individual), venom median lethal dose (LD??) and venom chromatographic profiles. The animals fed with the fish-based diet gained more weight, lived longer, and produced similar amount of venom whose biological and biochemical characteristics were similar to those of venom collected from specimens fed with the wild diet. This fish-based diet appears to be suitable (and preferable to the wild diet) to supply the nutritional requirements of a Micrurus nigrocinctus snake collection for the production of antivenom. PMID:22538193

Chacón, Danilo; Rodríguez, Santos; Arias, Jazmín; Solano, Gabriela; Bonilla, Fabián; Gómez, Aarón

2012-04-19

124

Annotated checklist of the recent and extinct pythons (Serpentes, Pythonidae), with notes on nomenclature, taxonomy, and distribution  

PubMed Central

Abstract McDiarmid et al. (1999) published the first part of their planned taxonomic catalog of the snakes of the world. Since then, several new python taxa have been described in both the scientific literature and non-peer-reviewed publications. This checklist evaluates the nomenclatural status of the names and discusses the taxonomic status of the new taxa, and aims to continue the work of McDiarmid et al. (1999) for the family Pythonidae, covering the period 1999 to 2010. Numerous new taxa are listed, and where appropriate recent synonymies are included and annotations are made. A checklist and a taxonomic identification key of valid taxa are provided.

Schleip, Wulf D.; O'Shea, Mark

2010-01-01

125

Large snakes in a mosaic rural landscape: The ecology of carpet pythons Morelia spilota (serpentes: Pythonidae) in coastal eastern Australia  

Microsoft Academic Search

How can large pythons coexist with human beings in highly modified habitats throughout the eastern coastal region of Australia, when the same species has undergone rapid declines in other parts of the country? To investigate this question, we surgically implanted miniature temperature-sensitive radiotransmitters into 19 adult carpet pythons Morelia spilota (body lengths 1·3–2·8 m; 1·4–7·0 kg) from two study sites

R. Shine; M. Fitzgerald

1996-01-01

126

Variation in mating systems and sexual size dimorphism between populations of the Australian python Morelia spilota (Serpentes: Pythonidae)  

Microsoft Academic Search

Although adaptationist hypotheses predict a functional relationship between mating systems and sexual size dimorphism, such predictions are difficult to test because of the high degree of phylogenetic conservatism in both of these traits. Taxa that show intraspecific variation in mating systems hence offer valuable opportunities for more direct tests of evolutionary-ecological hypotheses. Based on a collation of published and unpublished

R. Shine; M. Fitzgerald

1995-01-01

127

No time to worship the serpent deities: women, economic change, and religion in north-western Nepal.  

PubMed

This paper explores the changing relationships between lay women, and the spiritual realm, in two ethnic Tibetan communities, Kag and Dzong, in northwestern Nepal. The study tackles how economic and social change has affected women's spiritual roles within the household and the community, and how these roles, in turn, have influenced the course of such change. In Kag, the introduction of tourism changed women's way of life. They became income-generating members of the community as lodge-owners. With new responsibilities to manage, Kag women eventually neglected their traditional social and spiritual obligations, much to the dismay of the older generation. On the other hand, women in Dzong still consider full social and physical participation in village life important despite the added obligations. They maintain spiritual harmony within the village. Dzongba women do not seem to feel the same conflicts as Kagpa women. The negative impact of Kag women's neglect of traditional social and spiritual responsibilities should be weighed against the possible benefits to women, household, and economy. PMID:12295339

Saul, R

1999-03-01

128

Lessons Learned from Cosmic Serpent: A Professional Development Project for Informal Educators on Science and Native Ways of Knowing  

Microsoft Academic Search

How can one engage native communities and the public alike in understanding nature and our universe? Our approach has been to bring together practitioners at informal science centers, cultural museums, and tribal museums to develop relationships cross-culturally, to learn about different ways of studying and learning about nature and our universe, and to start to develop informal education programs or

L. M. Peticolas; N. Maryboy; D. Begay; R. Paglierani; R. Frappier; A. Teren

2011-01-01

129

Lessons Learned from Cosmic Serpent, a professional development project for informal educators on science and native ways of knowing  

Microsoft Academic Search

How can one engage native communities and the public alike in understanding nature and our universe? Our approach has been to bring together practitioners at informal science centers, cultural museums, and tribal museums to develop relationships cross culturally, learn about different ways of studying and learning about nature and our universe, and start to develop informal education programs or exhibits

L. M. Peticolas; N. Maryboy; D. Begay; R. Paglierani

2010-01-01

130

Body size as a primary determinant of ecomorphological diversification and the evolution of mimicry in the lampropeltinine snakes (Serpentes: Colubridae)  

Microsoft Academic Search

Evolutionary correlations between functionally related character suites are expected as a consequence of coadaptation due to physiological relationships between traits. However, significant correlations may also exist between putatively unrelated characters due to shared relationships between those traits and underlying variables, such as body size. Although such patterns are often dismissed as simple body size scaling, this presumption may overlook important

R. ALEXANDER PYRON; F. T. BURBRINK

2009-01-01

131

Body size as a primary determinant of ecomorphological diversification and the evolution of mimicry in the lampropeltinine snakes (Serpentes: Colubridae).  

PubMed

Evolutionary correlations between functionally related character suites are expected as a consequence of coadaptation due to physiological relationships between traits. However, significant correlations may also exist between putatively unrelated characters due to shared relationships between those traits and underlying variables, such as body size. Although such patterns are often dismissed as simple body size scaling, this presumption may overlook important evolutionary patterns of diversification. If body size is the primary determinant of potential diversity in multiple unrelated characters, the observed differentiation of species may be governed by variability in body size, and any biotic or abiotic constraints on the diversification thereof. Here, we demonstrate that traits related to both predatory specialization (gape and diet preference) and predatory avoidance (the development of Batesian mimicry) are phylogenetically correlated in the North American snake tribe Lampropeltini. This is apparently due to shared relationships between those traits and adult body size, suggesting that size is the primary determinant of ecomorphological differentiation in the lampropeltinines. Diversification in body size is apparently not linked to climatic or environmental factors, and may have been driven by interspecific interactions such as competition. Additionally, we find the presence of a 'key zone' for the development of both rattle- and coral snake mimicry; only small snakes feeding primarily on ectothermic prey develop mimetic colour patterns, in or near the range of venomous model species. PMID:19702841

Pyron, R Alexander; Burbrink, F T

2009-08-20

132

Phylogeography across a continent: the evolutionary and demographic history of the North American racer (Serpentes: Colubridae: Coluber constrictor).  

PubMed

Most phylogeographic studies examine organisms that do not have transcontinental distributions and therefore the genetic and temporal effects of barriers across an entire continent cannot be assessed with respect to a single species. We examined the phylogeographic structure, lineage age, and historical demography using sequences from the mtDNA cytochrome b gene of the widespread North American racer (Coluber constrictor), one of the few abundant transcontinental snakes that occurs throughout many diverse biomes. Our results indicate that this complex is comprised of six lineages differing greatly in geographic extent, with the largest (a central US clade) being approximately 26 times greater than the smallest (a lineage restricted to the Florida Panhandle and nearby portions of adjacent States). Most of the six lineages appear to be separated at previously identified genetic barriers for several vertebrates with similar ranges. Lineage diversification in this species began in the late Miocene, separating populations in the Florida Peninsula from the remainder of the US. Diversification of lineages continued throughout the Pliocene and early Pleistocene. Four of the six lineages occur east of the Mississippi River, with only two distinctly young ( approximately 1.5 mya) lineages found west of the Mississippi River (one occurs west of Continental Divide). All methods of demographic inference, including the mismatch distribution, Fu and Li's D and Tajima's D , and Bayesian skyline plots revealed population expansion occurring in the mid-to-late Pleistocene for every lineage, regardless of size or proximity to formerly glaciated areas. Population expansion for lineages found east of the Mississippi River occurred earlier and was much greater than those found west of the River. PMID:18093846

Burbrink, Frank T; Fontanella, Frank; Alexander Pyron, R; Guiher, Timothy J; Jimenez, Cynthia

2007-11-09

133

Lessons Learned from Cosmic Serpent, a professional development project for informal educators on science and native ways of knowing  

NASA Astrophysics Data System (ADS)

How can one engage native communities and the public alike in understanding nature and our universe? Our approach has been to bring together practitioners at informal science centers, cultural museums, and tribal museums to develop relationships cross culturally, learn about different ways of studying and learning about nature and our universe, and start to develop informal education programs or exhibits at their institution through their new understandings and peer networks. The design of the grant has been to provide an initial week-long professional development workshop in a region in the Western U.S. with a follow-up workshop in that region the following year, culminating in a final conference for all participants. We focus on three regions: the southwest (SW - Utah, Arizona, New Mexico and Colorado); the northwest (Alaska, Washington, and Oregon); and California. We are in our fourth year of our four year grant and have in this time organized and run three regional week-long workshops and two follow-up workshops (in the SW and NW). We have learned many lessons through this work, including: the importance of incorporating workshop participants as presenters in the workshop agenda; how the content of astronomy, earth science, ecology, and health resonates with these museum professionals and can easily be discussed with different world views in this type of cross cultural science education; and how to best present different ways of knowing how nature and our universe work (science) in a manner that provides a context for science educators and museum professionals. In our poster presentation, we will share these and other lessons we have learned from the leadership perspective of bringing together such a diverse and under-represented-in-science group of educators.

Peticolas, L. M.; Maryboy, N.; Begay, D.; Paglierani, R.

2010-12-01

134

Serpent: Magnetic signatures of serpentinized mantle and mesoscale oceanic variability along the Alaska/Aleutian subduction zone  

NASA Astrophysics Data System (ADS)

NASA recently solicited suborbital missions as a part of its new Earth Venture program element. These missions are designed as complete PI-led investigations to conduct innovative, integrated, hypothesis or scientific question driven approaches to pressing questions in Earth System science. The missions should require sustained observations (<5 years) and significant resources (<30 million USD). The submitted mission proposals have been under evaluation since last November, and NASA is scheduled to make a decision in April. We, a team led by Raytheon's Photon Research Associates, propose to carry out a suborbital magnetic survey of the Aleutian subduction zone using NASA's Global Hawk to test the magnetic serpentinite hypothesis. This hypothesis states that dewatering of the descending slab within subduction zones produces an observable static magnetic signature through the formation of serpentinite in the overriding mantle. This signature may serve as a predictor of the location of large megathrust earthquakes and their associated tsunamis. Magnetic field measurements from 20 km (sub-orbital) altitude are essential to the testing of this hypothesis; analysis shows orbital and/or near-surface measurements are not likely to provide sufficient sensitivity and uniform calibration to confirm or reject the hypothesis, nor to consistently map its presence around the world. Static and dynamic magnetic signatures from the motion of seawater in the earth's magnetic field have the potential to confound an evaluation of the magnetic serpentinite hypothesis. Through a combination of modeling and exact repeat surveys over the subduction zone, spaced weeks to as much as six months apart, we can study the magnetic signature of the motion that characterizes the mesoscale oceanic circulation in order to develop the best possible corrections for lithospheric imaging, and elucidating the intrinsic and unique oceanic information content in the magnetic fields for the first time ever. The role of water in subduction zones, and in the overlying ocean, can be traced by sustained suborbital observations of the magnetic field. At critical depths of 40 to 50 km, subducting ocean crust goes through important metamorphic changes that release large amounts of water into overriding mantle rocks. Introduction of water into the mantle produces serpentinite, a highly magnetic, low-density rock. Thermal models indicate that, in many of the world's subduction zones, this part of the mantle is cooler than the Curie temperature of magnetite, the most important magnetic mineral in serpentinite, and thus large volumes of mantle in subduction-margin settings should be magnetic. Indeed, analysis of magnetic data from some subduction zones indicates that magnetic mantle can be detected in long-wavelength magnetic anomalies. The presence of serpentinite in subduction margins has two important links to large within-slab and giant megathrust earthquakes, and associated tsunamis. First, release of water from the subducting slab is thought to embrittle the slab, thereby promoting within-slab earthquakes (M 7-8). Thus, we expect to see a spatial association between this type of earthquake and mantle magnetic anomalies. Second, in cool subduction margins, the down-dip limit of megathrust earthquakes (M 8.0-9.6) is controlled by the slab's first encounter with serpentinized mantle. Again, we expect to see a spatial association between these devastating earthquakes and magnetic anomalies. The magnetic serpentinite hypothesis can be tested by comparison to free-air gravity, geologic, topographic, and bathymetric data of comparable resolution. Significant static and dynamic magnetic fields also originate as a consequence of oceanic flow in electrically conducting ocean water above the subduction zone. Although these signals are of much lower amplitude than the magnetic field associated with serpentinite, they can have significant power at short spatial scales, and thus have the potential to confound estimated magnetic source depths that rely on inferences from the

Purucker, Michael; Serpent Team

2010-05-01

135

Lessons Learned from Cosmic Serpent: A Professional Development Project for Informal Educators on Science and Native Ways of Knowing  

NASA Astrophysics Data System (ADS)

How can one engage native communities and the public alike in understanding nature and our universe? Our approach has been to bring together practitioners at informal science centers, cultural museums, and tribal museums to develop relationships cross-culturally, to learn about different ways of studying and learning about nature and our universe, and to start to develop informal education programs or exhibits at their institution through their new understandings and peer networks. The design of this National Science Foundation (NSF) grant has been to provide an initial week-long professional development workshop in a region in the Western U.S. with a follow-up workshop in that region the following year, culminating in a final conference for all participants. We focus on three regions: the southwest (Utah, Arizona, New Mexico, and Colorado), the northwest (Alaska, Washington, and Oregon); and California. We are in our third year of our four-year grant and have in this time organized and run three regional week-long workshops and a follow-up workshop in the southwest. We have learned many lessons through this work, including: the importance of incorporating workshop participants as presenters in the workshop agenda; how the content of astronomy, ecology, and health resonates with these museum professionals and can easily be discussed with different world views in this type of cross-cultural science education; and how to best present different ways of knowing how nature and our universe work (science) in a manner that provides a context for science educators and museum professionals. In this article, we share these and other lessons we have learned from the leadership perspective of bringing together such a diverse and under-represented-in-science group of educators.

Peticolas, L. M.; Maryboy, N.; Begay, D.; Paglierani, R.; Frappier, R.; Teren, A.

2011-09-01

136

The Descent of the Serpent: Using a Successful Ancient Solar Observatories Webcast from Chichen Itza to Highlight Space Weather Research  

Microsoft Academic Search

Over the past seven years, NASA's Sun-Earth Connection Education Forum has sponsored and coordinated education and public outreach events to highlight NASA's heliophysics research and discoveries. Our strategy involves using celestial events, such as total solar eclipses and the Transit of Venus, as well as Sun-Earth Day during the March Equinox, to engage K-12 schools and the general public in

I. Hawkins; R. Higdon; T. Cline

2006-01-01

137

Domain loss facilitates accelerated evolution and neofunctionalization of duplicate snake venom metalloproteinase toxin genes.  

PubMed

Gene duplication is a key mechanism for the adaptive evolution and neofunctionalization of gene families. Large multigene families often exhibit complex evolutionary histories as a result of frequent gene duplication acting in concordance with positive selection pressures. Alterations in the domain structure of genes, causing changes in the molecular scaffold of proteins, can also result in a complex evolutionary history and has been observed in functionally diverse multigene toxin families. Here, we investigate the role alterations in domain structure have on the tempo of evolution and neofunctionalization of multigene families using the snake venom metalloproteinases (SVMPs) as a model system. Our results reveal that the evolutionary history of viperid (Serpentes: Viperidae) SVMPs is repeatedly punctuated by domain loss, with the single loss of the cysteine-rich domain, facilitating the formation of P-II class SVMPs, occurring prior to the convergent loss of the disintegrin domain to form multiple P-I SVMP structures. Notably, the majority of phylogenetic branches where domain loss was inferred to have occurred exhibited highly significant evidence of positive selection in surface-exposed amino acid residues, resulting in the neofunctionalization of P-II and P-I SVMP classes. These results provide a valuable insight into the mechanisms by which complex gene families evolve and detail how the loss of domain structures can catalyze the accelerated evolution of novel gene paralogues. The ensuing generation of differing molecular scaffolds encoded by the same multigene family facilitates gene neofunctionalization while presenting an evolutionary advantage through the retention of multiple genes capable of encoding functionally distinct proteins. PMID:21478373

Casewell, Nicholas R; Wagstaff, Simon C; Harrison, Robert A; Renjifo, Camila; Wüster, Wolfgang

2011-04-04

138

Comparative venom gland transcriptome surveys of the saw-scaled vipers (Viperidae: Echis) reveal substantial intra-family gene diversity and novel venom transcripts  

PubMed Central

Background Venom variation occurs at all taxonomical levels and can impact significantly upon the clinical manifestations and efficacy of antivenom therapy following snakebite. Variation in snake venom composition is thought to be subject to strong natural selection as a result of adaptation towards specific diets. Members of the medically important genus Echis exhibit considerable variation in venom composition, which has been demonstrated to co-evolve with evolutionary shifts in diet. We adopt a venom gland transcriptome approach in order to investigate the diversity of toxins in the genus and elucidate the mechanisms which result in prey-specific adaptations of venom composition. Results Venom gland transcriptomes were created for E. pyramidum leakeyi, E. coloratus and E. carinatus sochureki by sequencing ~1000 expressed sequence tags from venom gland cDNA libraries. A standardised methodology allowed a comprehensive intra-genus comparison of the venom gland profiles to be undertaken, including the previously described E. ocellatus transcriptome. Blast annotation revealed the presence of snake venom metalloproteinases, C-type lectins, group II phopholipases A2, serine proteases, L-amino oxidases and growth factors in all transcriptomes throughout the genus. Transcripts encoding disintegrins, cysteine-rich secretory proteins and hyaluronidases were obtained from at least one, but not all, species. A representative group of novel venom transcripts exhibiting similarity to lysosomal acid lipase were identified from the E. coloratus transcriptome, whilst novel metallopeptidases exhibiting similarity to neprilysin and dipeptidyl peptidase III were identified from E. p. leakeyi and E. coloratus respectively. Conclusion The comparison of Echis venom gland transcriptomes revealed substantial intrageneric venom variation in representations and cluster numbers of the most abundant venom toxin families. The expression profiles of established toxin groups exhibit little obvious association with venom-related adaptations to diet described from this genus. We suggest therefore that alterations in isoform diversity or transcript expression levels within the major venom protein families are likely to be responsible for prey specificity, rather than differences in the representation of entire toxin families or the recruitment of novel toxin families, although the recruitment of lysosomal acid lipase as a response to vertebrate feeding cannot be excluded. Evidence of marked intrageneric venom variation within the medically important genus Echis strongly advocates further investigations into the medical significance of venom variation in this genus and its impact upon antivenom therapy.

2009-01-01

139

Isolation, characterization and molecular cloning of AnMIP, a new ?-type phospholipase A 2 myotoxin inhibitor from the plasma of the snake Atropoides nummifer (Viperidae: Crotalinae)  

Microsoft Academic Search

A new phospholipase A2 (PLA2)-inhibitory protein was isolated from the plasma of Atropoides nummifer, a crotaline snake from Central America. This inhibitor was named AnMIP, given its ability to neutralize the activity of basic PLA2 myotoxins of its own and related venoms. The cDNA of AnMIP was cloned and sequenced, showing that it belongs to the ? group of phospholipase

Steve Quirós; Alberto Alape-Girón; Yamileth Angulo; Bruno Lomonte

2007-01-01

140

Annual cycles in plasma testosterone and thyroxine in the male aspic viper Vipera aspis L., (Reptilia, Viperidae), in relation to the sexual cycle and hibernation.  

PubMed

Blood samples were taken monthly from males of Vipera aspis kept in outdoor terraria. Plasma testosterone was estimated by radioimmunoassay and plasma thyroxine by the technique of isotopic competition, between October 1979 and September 1985. Plasma testosterone showed an annual bimodal profile. The highest peak was observed from February 15 to the end of March. 2 to 5 weeks after the first emergence from hibernation. Values then decreased greatly, to reach a minimum level when the vernal spermiogenesis was at its maximum. The secondary peak of plasma testosterone was lower and less well marked. It occurred at the end of summer, during the strongest spermiogenesis, and preceded the autumnal facultative mating period. Plasma thyroxine was at a maximum concentration from February to March after which levels decreased markedly. The seasonal profile of plasma thyroxine was clearly marked during the period of hibernation. From September to October, 2 months before the beginning of hibernation, thyroxine levels began to decrease, and they reached a minimum in November-December. Endocrine reactivation of the thyroid appeared at the end of hibernation. However, in contrast to the plasma testosterone, endocrine activity of the thyroid began 2 to 3 weeks before the end of hibernation. Mechanisms of reactivation for testicular and thyroidal endocrine structures are discussed. PMID:3817449

Naulleau, G; Fleury, F; Boissin, J

1987-02-01

141

A relict lineage and new species of green palm-pitviper (Squamata, Viperidae, Bothriechis) from the Chort?s Highlands of Mesoamerica  

PubMed Central

Abstract A new species of palm-pitviper of the genus Bothriechis is described from Refugio de Vida Silvestre Texíguat in northern Honduras. The new species differs from congeners by having 19 dorsal scale rows at midbody, a bright green dorsal coloration in adults, the prelacunal scale fused to the second supralabial, and in representing a northern lineage that is sister to Bothriechis lateralis, which is distributed in Costa Rica and western Panama and is isolated from the new taxon by the Nicaraguan Depression. This represents the 15th endemic species occurring in Refugio de Vida Silvestre Texíguat, one of the richest herpetofaunal sites in Honduras, itself being the country with the highest degree of herpetofaunal endemism in Central America. We name this new species in honor of a Honduran conservationist slain in fighting against illegal logging, highlighting the sacrifices of rural activists in battling these issues and the critical importance of conservation in these areas.

Townsend, Josiah H.; Medina-Flores, Melissa; Wilson, Larry David; Jadin, Robert C.; Austin, James D.

2013-01-01

142

Food resources influence spatial ecology, habitat selection, and foraging behavior in an ambush-hunting snake (Viperidae: Bothrops asper): an experimental study.  

PubMed

Prey availability affects many aspects of predators' life history and is considered a primary factor influencing individuals' decisions regarding spatial ecology and behavior, but few experimental data are currently available. Snakes may represent ideal model organisms relative to other animal groups for addressing such resource dependency, due to a presumably more direct link between food resources and many aspects of behavior and natural history. We experimentally investigated the relationship between food intake and spatial behavior in a population of the snake Bothrops asper in a Costa Rican lowland rainforest. Six adult snakes were allowed to forage naturally while six were offered supplemental food in the field, with both groups monitored using radiotelemetry. Mean home range size did not differ between groups presumably due to small sample size, but supplementally fed snakes demonstrated altered patterns of macro- and microhabitat selection, shorter and less frequent movements, and increased mass acquisition. Fed snakes also devoted less time to foraging efforts, instead more frequently remaining inactive and utilizing shelter. Because snakes were always fed in situ and not at designated feeding stations, observed shifts in habitat selection are not explained by animals simply moving to areas of higher food availability. Rather, B. asper may have moved to swamps in order to feed on amphibians when necessary, but remained in preferred forest habitat when food was otherwise abundant. The strong behavioral and spatiotemporal responses of snakes in this population may have been influenced by an overall scarcity of mammalian prey during the study period. PMID:22440190

Wasko, Dennis K; Sasa, Mahmood

2012-03-21

143

Evolution of rattlesnakes (Viperidae; Crotalus) in the warm deserts of western North America shaped by Neogene vicariance and Quaternary climate change.  

PubMed

During Pleistocene, the Laurentide ice sheet rearranged and diversified biotic distributions in eastern North America, yet had minimal physical impact in western North America where lineage diversification is instead hypothesized to result from climatic changes. If Pleistocene climatic fluctuations impacted desert species, the latter would reflect patterns of restricted gene flow concomitant with indications of demographic bottlenecks. Accordingly, molecular evidence for refugia should be present within these distributions and for subsequent range expansions as conditions improved. We sought answers to these questions by evaluating mitochondrial DNA (mtDNA) sequences from four species of rattlesnakes [Crotalus mitchellii (speckled rattlesnake), Crotalus cerastes (sidewinder), Crotalus tigris (tiger rattlesnake), Crotalus ruber (red diamond rattlesnake)] with distributions restricted to desert regions of southwestern North America. We inferred relationships using parsimony and maximum likelihood, tested intraspecific clades for population expansions, applied an isolation-with-migration model to determine bi-directional migration rates (m) among regions, and inferred divergence times for species and clades by applying a semiparametric penalized likelihood approach to our molecular data. Evidence for significant range expansion was present in two of eight regions in two species (Crotalus mitchellii pyrrhus, C. tigris region north). Two species (C. cerastes, C. mitchellii) showed a distribution concomitant with northward displacement of Baja California from mainland México, followed by vicariant separation into subclades. Effects of Pleistocene climate fluctuations were found in the distributions of all four species. Three regional diversification patterns were identified: (i) shallow genetic diversity that resulted from Pleistocene climatic events (C. tigris, C. ruber); (ii) deep Pleistocene divisions indicating allopatric segregation of subclades within refugia (C. mitchellii, C. cerastes); and (iii) lineage diversifications that extended to Pliocene or Late Miocene (C. mitchellii, C. cerastes). Clade-diversifying and clade-constraining effects impacted the four species of rattlesnakes unequally. We found relatively high levels of molecular diversification in the two most broadly distributed species (C. mitchellii, C. cerastes), and lower levels of genetic diversification in the two species (C. tigris, C. ruber) whose ranges are relatively more restricted. Furthermore, in several cases, the distributions of subspecies were not congruent with our molecular information. We suggest regional conservation perspectives for southwestern deserts cannot rely upon subspecies as biodiversity surrogates, but must instead employ a molecular and deep historical perspective as a primary mechanism to frame biodiversity reserves within this region. PMID:16968275

Douglas, Michael E; Douglas, Marlis R; Schuett, Gordon W; Porras, Louis W

2006-10-01

144

Rose Lovell-Smith - Eggs and Serpents: Natural History Reference in Lewis Carroll's Scene of Alice and the Pigeon - Children's Literature 35:1  

Microsoft Academic Search

Alice's encounter with a Wonderland pigeon derives from a common scenario in nineteenth-century natural history publishing where a predator attacks a nest. The natural history intertext indicates that Carroll's Alice books use animal characters to reflect on Darwin's theory of species origin, on human identity, and on the child's place in nature.


Rose Lovell-Smith

2007-01-01

145

Inferring Species Trees from Gene Trees: A Phylogenetic Analysis of the Elapidae (Serpentes) Based on the Amino Acid Sequences of Venom Proteins  

Microsoft Academic Search

Toward the goal of recovering the phylogenetic relationships among elapid snakes, we separately found the shortest trees from the amino acid sequences for the venom proteins phospholipase A2and the short neurotoxin, collectively representing 32 species in 16 genera. We then applied a method we term gene tree parsimony for inferring species trees from gene trees that works by finding the

Joseph B. Slowinski; Alec Knight; Alejandro P. Rooney

1997-01-01

146

Geographic genetic structure in two laticaudine sea kraits, Laticauda laticaudata and Laticauda semifasciata (Serpentes: Elapidae), in the Ryukyu-Taiwan region as inferred from mitochondrial cytochrome b sequences.  

PubMed

The Ryukyu-Taiwan region is an island arch with intervening waters of varying distances and depths. This study examines the geographic genetic structure of two sympatric sea kraits, Laticauda laticaudata and L. semifasciata, in the region, to infer factors affecting the extent of dispersal and other biogeographical traits of these amphibious reptiles. Sequence analyses of the mitochondrial cytochrome b gene revealed four and 16 haplotypes for L. laticaudata (136 individuals) and L. semifasciata (177 individuals), respectively. For both species, population pairwise F ST analyses revealed significant genetic differentiations among islands and island groups, which are separated by deep straits, suggesting that deep waters serve as obstacles for dispersal in both species. Significant genetic differentiation was detected even among islands of the same basin in L. laticaudata, but not in L. semifasciata, and the isolation by distance analyses revealed no significant correlation between geographic and genetic distances in the former species. These results further suggest that L. laticaudata has stronger site fidelity or degree of philopatry than L. semifasciata. Based on the geographic genetic patterns, the historical biogeography of the two species in the Ryukyu-Taiwan region is also discussed. PMID:23915156

Tandavanitj, Nontivich; Ota, Hidetoshi; Cheng, Yuan-Cheng; Toda, Mamoru

2013-08-01

147

The phylogeny of cobras inferred from mitochondrial DNA sequences: evolution of venom spitting and the phylogeography of the African spitting cobras (Serpentes: Elapidae: Naja nigricollis complex).  

PubMed

We use phylogenetic analysis of 1333 bp of mitochondrial DNA sequence to investigate the phylogeny and historical biogeography of the cobra-like elapid snakes, with special reference to the evolution of spitting and the phylogeography of the African spitting cobras, a radiation widespread in open vegetational formations throughout sub-Saharan Africa. Our results suggest that spitting adaptations appear to have evolved three times in cobras, but alternative scenarios cannot be rejected. The Asiatic Naja are monophyletic and originate from a single colonization of Asia from Africa. The radiation of the African spitting Naja appears to date back to the early Miocene and many speciation events in the group predate the Pliocene expansion of grasslands and the radiation of large grazing mammals in Africa. The cladogenic events in this complex appear to have been triggered by both ecological changes and tectonic events associated with the formation and expansion of the African Rift Valley. Taxonomically, our data confirm the inclusion of Boulengerina and Paranaja within Naja, and reveal a clade of African rainforest cobras including N. melanoleuca, Paranaja multifasciata and Boulengerina that constitutes the sister clade of the African open-formation non-spitting cobras. Naja nigricollis is polyphyletic, and we therefore recognize N. nigricincta as a separate species, more closely related to N. ashei and N. mossambica than to N. nigricollis. PMID:17870616

Wüster, Wolfgang; Crookes, Steven; Ineich, Ivan; Mané, Youssouph; Pook, Catharine E; Trape, Jean-François; Broadley, Donald G

2007-08-14

148

Isolation, characterization and molecular cloning of AnMIP, a new alpha-type phospholipase A2 myotoxin inhibitor from the plasma of the snake Atropoides nummifer (Viperidae: Crotalinae).  

PubMed

A new phospholipase A(2) (PLA(2))-inhibitory protein was isolated from the plasma of Atropoides nummifer, a crotaline snake from Central America. This inhibitor was named AnMIP, given its ability to neutralize the activity of basic PLA(2) myotoxins of its own and related venoms. The cDNA of AnMIP was cloned and sequenced, showing that it belongs to the alpha group of phospholipase A(2) inhibitors (PLIs). AnMIP appears as a homotrimer in the native state, held together by non-covalent forces, with a subunit molecular mass of 22,247-22,301 and an isoelectric point of 4.1-4.7. This trimeric structure is the first observed in a PLIalpha from American crotaline snakes, previously reported only in Asian species. Sequencing, mass spectrometry, and analytical isoelectrofocusing indicated the existence of isoforms, as reported for other PLIalphas isolated from snake plasma. The inhibitory profile of AnMIP showed specificity towards group II PLA(2)s, either belonging to the catalytically-active (D49) or -inactive (K49) subtypes, exemplified in this study by Bothrops asper myotoxin I and A. nummifer myotoxin II, respectively. By phylogenetic analysis it was shown that AnMIP is closely related to CgMIP-II, previously isolated from the plasma of Cerrophidion godmani, showing 93% amino acid sequence identity. PMID:17071122

Quirós, Steve; Alape-Girón, Alberto; Angulo, Yamileth; Lomonte, Bruno

2006-09-26

149

Geophysics could explain Ancient Maya Myth  

Microsoft Academic Search

According to Maya mythology, the splendor of the principal entity, the Feathered Serpent, is exalted at Lake Atitlán in southwestern Guatemala. A chance look at a phenomenon in the natural environment reveals the possible geophysical basis of this myth.More than poetic fancy, the flight of the Feathered Serpent could refer to the dissipation of a soliton wave formed in the

Margaret Sabom Bruchez

2005-01-01

150

Resistance of the Opossum (Didelphis Virginiana) to Envenomation by Snakes of the Crotalidae Family.  

National Technical Information Service (NTIS)

Whether the North American opossum, Dipelphis virginiana, has a natural resistance to envenomation by 12 species of snakes from the families Crotalidae, Viperidae, Elapidae, and Hyprophidae was studied. Challenge of the anesthetized opossum was by actual ...

R. M. Werner J. A. Vick

1976-01-01

151

Electrophoretic Characterization of Elapid, Viperid and Crotalid Snake Venoms.  

National Technical Information Service (NTIS)

This report deals with comparative studies of snake venoms from 21 species representing Elapidae, Crotalidae and Viperidae. Both native and denatured venoms were analyzed by polyacrylamide gel electrophoretic methods with or without sodium dodecyl sulfate...

A. R. Bhatti C. E. Connolley-Mendoza T. Bhatti

1989-01-01

152

Radiant Heat Reception in Snakes.  

National Technical Information Service (NTIS)

Sixteen species of snakes, in the Boidae, Viperidae, Hydrophidae and Colubridae were examined electrophysiologically and compared with the seven species of Crotalidae previously described, with respect to the presence and character of receptors for infrar...

T. H. Bullock R. Barrett

1968-01-01

153

Cardiovascular and Respiratory Effects of Snake Venoms.  

National Technical Information Service (NTIS)

The physiological effects of venoms representing four families of poisonous snakes (Crotalidae, Elapidae, Viperidae, and Hydrophidae) were studied in 16 healthy, adult, anesthetized dogs. Blood pressure, heart rate, electrocardiogram, cardiac output, left...

H. L. Froehlich J. A. Vick

1975-01-01

154

The Seminole Serpent Warrior At Miramar, FL, Shows Settlement Locations Enabled Environmental Monitoring Reminiscent Of the Four-corners Kokopelli-like EMF Phenomena, and Related to Earthquakes, Tornados and Hurricanes.  

NASA Astrophysics Data System (ADS)

Certain Native Americans of the past seem to have correctly deduced that significant survival information for their tradition-respecting cultures resided in EMF-based phenomena that they were monitoring. This is based upon their myths and the place or cult-hero names they bequeathed us. The sites we have located in FL have been detectable by us visually, usually by faint blue light, or by the elicitation of pin-like prickings, by somewhat intense nervous-system response, by EMF interactions with aural electrochemical systems that can elicit tinitus, and other ways. In the northeast, Cautantowit served as a harbinger of Indian summer, and appears to be another alter ego of the EMF. The Miami, FL Tequesta site along the river clearly correlates with tornado, earthquake and hurricane locations. Sites like the Mohave Deserts giant man may have had similar significance.

Balam Matagamon, Chan; Pawa Matagamon, Sagamo

2004-03-01

155

A revision of the South American snake genus Thamnodynastes Wagler, 1830 (Serpentes, Colubridae, Tachymenini). I. Two new species of Thamnodynastes from Central Brazil and adjacent areas, with a redefinition of and neotype designation for Thamnodynastes pallidus (Linnaeus, 1758)  

Microsoft Academic Search

A revision of the South American snake genus Thamnodynastes Wagler, 1830 (Ser- pentes, Colubridae, Tachymenini). I. Two new species of Thamnodynastes from Central Brazil and adjacent areas, with a redescription of and neotype designation for Thamndynastes pallidus (Linnaeus, 1758). Two new species of Thamnodynastes whose ranges are entirely or largely in Brazil are described. Thamnodynastes pallidus, one of the most

Joseph R. Bailey; Robert A. Thomas; Nelson Jorge da Silva Jr

156

Geophysics Could Explain Ancient Maya Myth  

NASA Astrophysics Data System (ADS)

According to Maya mythology, the splendor of the principal entity, the Feathered Serpent, is exalted at Lake Atitlán in southwestern Guatemala. A chance look at a phenomenon in the natural environment reveals the possible geophysical basis of this myth. More than poetic fancy, the flight of the Feathered Serpent could refer to the dissipation of a soliton wave formed in the 130-km2 caldera lake. In the myth, recounted in the sixteenth century document los anales de los caqchiqueles, the newly acceded leader of the Kaqchikel-speaking Maya tribe rises from the lake transformed as the Feathered Serpent [Recinos and Goetz, 1953, p. 76]. Residents claim a gigantic serpent, Xocomil, still lives in the waters.

Sabom Bruchez, Margaret

2005-03-01

157

Geophysics could explain Ancient Maya Myth  

NASA Astrophysics Data System (ADS)

According to Maya mythology, the splendor of the principal entity, the Feathered Serpent, is exalted at Lake Atitlán in southwestern Guatemala. A chance look at a phenomenon in the natural environment reveals the possible geophysical basis of this myth.More than poetic fancy, the flight of the Feathered Serpent could refer to the dissipation of a soliton wave formed in the 130-km2 caldera lake. In the myth, recounted in the sixteenth century document los anales de los caqchiqueles, the newly acceded leader of the Kaqchikel-speaking Maya tribe rises from the lake transformed as the Feathered Serpent [Recinos and Goetz, 1953, p. 76]. Residents claim a gigantic serpent, Xocomil, still lives in the waters.

Bruchez, Margaret Sabom

158

78 FR 64691 - Endangered and Threatened Wildlife and Plants; Listing Five Foreign Bird Species in Colombia and...  

Federal Register 2010, 2011, 2012, 2013

...Serpentes), foxes (family Canidae), wild cats (Felis silvestris), feral dogs (Canus...Summary of Factor C Snakes, foxes, feral cats, feral dogs, and raptors are all predators...predators, including snakes, foxes, feral cats, feral dogs, and raptors (Factor...

2013-10-29

159

Failure to protect Mice against Endotoxin with Snake Venom  

Microsoft Academic Search

WHEN bacterial exotoxin, endotoxin, or snake venom is injected intravenously into animals, peripheral vascular collapse occurs. Preliminary investigations demonstrated that the administration of sub-lethal doses of Escherichia coli, Salmonella typhi or brucella endotoxins protected mice against lethal doses of snake venoms (Crotalus terrificus and Bothrops jararaca). Since North and Doery1 have reported that the venom of the Australian tiger snake

Wesley W. Spink; Chancy K. Su

1963-01-01

160

Gene expression in SK-Mel-28 human melanoma cells treated with the snake venom jararhagin  

Microsoft Academic Search

Alternative approaches to improve the treatment of advanced melanomas are highly needed. The disintegrin domain of metalloproteinases binds integrin receptors on tumor cells, blocking migration, invasion, and metastatization. Previous studies showed that jararhagin, from the Bothrops jararaca snake venom, induces changes in the morphology and viability of SK-Mel-28 human melanoma cells, and decreases the number of metastases in mice injected

Anelise Klein; Juliana Silva Capitanio; Durvanei Augusto Maria; Itamar Romano Garcia Ruiz

2011-01-01

161

Effects of Jarastatin, a Novel Snake Venom Disintegrin, on Neutrophil Migration and Actin Cytoskeleton Dynamics  

Microsoft Academic Search

A new disintegrin, an RGD-containing peptide of 6 kDa called jarastatin, was purified from Bothrops jararaca venom. It is a potent inhibitor of platelet aggregation induced by ADP, collagen, and thrombin. The effect of jarastatin on neutrophil migration in vivo and in vitro and on the actin cytoskeleton dynamics of these cells was investigated. Incubation in vitro with jarastatin significantly

Ana Lucia J. Coelho; Marta S. de Freitas; Ana Lucia Oliveira-Carvalho; Vivaldo Moura-Neto; Russolina B. Zingali; Christina Barja-Fidalgo

1999-01-01

162

Inhibition of melanoma cells tumorigenicity by the snake venom toxin jararhagin  

Microsoft Academic Search

Skmel-28 human melanoma cells were treated with jararhagin (Jara), a metalloproteinase disintegrin isolated from Bothrops jararaca snake venom, and Jari (Jara with the catalytic domain inactivated). Following treatments, monolayer cells lost cytoplasmic expansions acquiring round shapes, detached and formed cell clusters in suspension. Cytotoxicity effect of Jari was dramatically increased at concentrations higher than 0.4?M, whereas cell adhesion responses did

Mário César Corrêa; Durvanei A. Maria; Ana M. Moura-da-Silva; Kazumi F. Pizzocaro; Itamar R. G. Ruiz

2002-01-01

163

Fluorometric assay using naphthylamide substrates for assessing novel venom peptidase activities  

Microsoft Academic Search

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)

Elaine Gasparello-Clemente; Paulo Flávio Silveira

2002-01-01

164

Anti Echis carinatus venom antibodies from chicken egg yolk: Isolation, purification and neutralization efficacy  

Microsoft Academic Search

High titer antibodies (IgY) were raised in egg yolk of white leghorn chicken (Gallus gallus domesticus) by immunizing with the venom of Echis carinatus (Saw scaled viper or carpet viper), an Indian venomous snake belonging to the family Viperidae. The anti-snake venom antibodies (antivenom) were isolated from egg yolk by the water dilution method, enriched by 19% sodium sulfate precipitation

K. Paul; J. Manjula; E. P. Deepa; Z. E. Selvanayagam; K. A. Ganesh; P. V. Subba Rao

2007-01-01

165

Evolution \\/ Évolution The phylogeny and classification of caenophidian snakes inferred from seven nuclear protein-coding genes  

Microsoft Academic Search

More than 80% of the approximately 3000 living species of snakes are placed in the taxon Caenophidia (advanced snakes), a group that includes the families Acrochordidae, Viperidae, Elapidae, Atractaspididae, and the paraphyletic 'Colubridae'. Previous studies using DNA sequences have involved few nuclear genes (one or two). Several nodes have therefore proven difficult to resolve with statistical significance. Here, we investigated

Nicolas Vidal; Anne-Sophie Delmas; Patrick David; Corinne Cruaud; Arnaud Couloux; S. Blair Hedges

166

Phospholipase A2 inhibitors isolated from medicinal plants: alternative treatment against snakebites.  

PubMed

Many plants are used in traditional medicine as active agents against various effects of snake bites. Phospholipase A2 enzymes are commonly found in venoms of snakes of the Viperidae and Elaphidae families, which are their main components. This article presents an overview of inhibitors isolated from plants, which show antiophidian properties. PMID:23544601

Hage-Melim, Lorane I S; Sampaio, Suely V; Taft, Carlton A; Silva, Carlos H T P

2013-07-01

167

From chimera to chimaera: Changing the realities for youth in Solomon Islands  

Microsoft Academic Search

In classic mythology, a chimera was a fire-breathing mythical beast with a lion's head, a goat's body and a serpent's tail. The word has come to mean an impossible or foolish fantasy. I suggest that the head of the youth 'chimera' represents universal education, the body represents full employment and the tail represents the new political economy, one with a

Christopher Chevalier

168

Cellular and theoretical chimeras: Piecing together how cells process energy  

Microsoft Academic Search

AMONG THE fantastic creatures that Homer described in the Iliad is the chimera, a fire-breathing monster with the head of a lion, the body of a goat and the tail of a serpent. Biologically, the chimera is unimaginable-a quintessentially mythical creature. Yet as an improbable hybrid, it also served as a model for naming another, very real product of cellular

Douglas Allchin

1996-01-01

169

Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome  

Microsoft Academic Search

We provide phylogenetic analyses for primary Reptilia lineages including, for the first time, Sphenodon punctatus (tuatara) using data from whole mitochondrial genomes. Our analyses firmly support a sister relationship between Sphenodon and Squamata, which includes lizards and snakes. Using Sphenodon as an outgroup for select squamates, we found evidence indicating a sister relationship, among our study taxa, between Serpentes (represented

Joshua S. Rest; Jennifer C. Ast; Christopher C. Austin; Peter J. Waddell; Elizabeth A. Tibbetts; Jennifer M. Hay; David P. Mindella

2003-01-01

170

A Little-known Peculiarity of the Hamadryad Snake  

Microsoft Academic Search

A STRUCTURAL peculiarity of the ``king cobra'' which I have recently ascertained while studying the anatomy of the Ophidia seems to me to be so remarkable that it must have been noticed in such comprehensive works as Bronn's ``Thierreich'' and Dr. Gadow's account of serpents in the ``Cambridge Natural History'' were it known. I venture, therefore, to give a short

Frank E. Beddard

1903-01-01

171

On centipedes collected on the Raleigh International Expedition to Mauritius and Rodrigues 1993, with a description of a new species of Scolopendra (Scolopendromorpha; Scolopendridae)  

Microsoft Academic Search

Three species of Scolopendra are recorded from islands off Mauritius and Rodrigues, Indian Ocean. A new species, S. abnormis, is described from Round and Serpent Is. The marked colour variation of the S. morsitans population from Ile aux Cocos, Rodrigues is described.

J. G. E. Lewis; P. Daszak

1996-01-01

172

Ecological Function of Venom in Varanus, with a Compilation of Dietary Records from the Literature  

Microsoft Academic Search

Until recently, venom in reptiles was thought to be present in two lineages: Serpentes and Heloderma. Research has now shown that venom evolved only once in reptiles, in a venom clade known as Toxicofera. This has resulted in venoms being discovered in many more species within this clade, including monitor lizards, genus Varanus. To date, very little work has been

KEVIN ARBUCKLE

173

Animal Symbols in the Art of the Hodensaunee.  

ERIC Educational Resources Information Center

Explains the significance of the main animal symbols incorporated into the social, cultural, artistic, and spiritual fabric of the Hodenosaunee (the People of the Longhouse) also known as the Six Nations Iroquois: the eagle, turtle, bear, wolf, hawk, heron, snipe, eel, deer, beaver, moose, snake, and serpent. (NEC)

Hill, Richard

1987-01-01

174

A GATA\\/RUNX cis-regulatory module couples Drosophila blood cell commitment and differentiation into crystal cells  

Microsoft Academic Search

Members of the RUNX and GATA transcription factor families play critical roles during hematopoiesis from Drosophila to mammals. In Drosophila, the formation of the crystal cell hematopoietic lineage depends on the continuous expression of the lineage-specific RUNX factor Lozenge (Lz) and on its interaction with the GATA factor Serpent (Srp). Crystal cells are the main source of prophenoloxidases (proPOs), the

Géraldine Ferjoux; Benoit Augé; Karène Boyer; Marc Haenlin; Lucas Waltzer

2007-01-01

175

Palaeophis casei, new species, a tiny palaeophid snake from the early Eocene of Mississippi  

Microsoft Academic Search

Fourteen vertebrae from an estuarine site in the Bashi Marl early Eocene of Meridian, Lauderdale County, Mississippi, represent Palaeophis casei n. sp. (Ser-pentes: Palaeophidae). The snake resembles Palaeophis virginianus and differs from other American species in having but a single vertebral hypapophysis; however, it differs from the giant P. virginianus in being quite small, as well as in several other

J. Alan Holman

1982-01-01

176

Molecular systematics of New World lampropeltinine snakes (Colubridae): implications for biogeography and evolution of food habits  

Microsoft Academic Search

We used mitochondrial gene sequences to infer phylogenetic relationships among North American snakes of the colubrid tribe Lampropeltini (Arizona, Bogertophis, Cemophora, New World Elaphe,Lampropeltis , Pituophis, Rhinocheilus, Senticolis, Stilosoma), and assessed the implications of our findings for the biogeography and evolution of food habits among these serpents. The maximum likelihood phylogeny identified Rhinocheilus as the sister taxon to all other

JAVIER A RODRÍGUEZ-ROBLES; JOSÉ M DE JESÚS-ESCOBAR

1999-01-01

177

Radium226 in cattails, Typha latifolia, and bone of muskrat, Ondatra zibethica (L.), from a watershed with uranium tailings near the city of Elliot Lake, Canada  

Microsoft Academic Search

Radium-226 concentrations were measured in the main food plants (cattails, Typha latifolia) and bone of adult muskrats (Ondatra zibethica (L.)), taken from a study area near Quirke Lake in the Serpent River drainage basin. This watershed receives drainage containing radionuclides from the U tailings near the City of Elliot Lake, Ontario, Canada. Two control sites (one local, one 130 km

M. A. Mirka; F. V. Clulow; N. K. Davé; T. P. Lim

1996-01-01

178

The history of the evil eye and its influence on ophthalmology, medicine and social customs.  

PubMed

Belief in the evil eye is one of the oldest and most widespread superstitions in the world. The concept of the evil eye has influenced present day ophthalmology, medicine, and social customs. Oculus sinister (OS), the serpent and the staff of Asclepius, the symbol of RX, and many social customs are historically related to the evil eye. PMID:9657293

Bohigian, G H

1997-01-01

179

Ophiuchus  

Microsoft Academic Search

(the Serpent-bearer; abbrev. Oph, gen. Ophiuchi; area 948 sq. deg.) An equatorial constellation which lies between Hercules and Scorpius, and culminates at midnight in mid-June. The ecliptic cuts across the southern part of Ophiuchus, but the constellation is not included among the constellations of the zodiac. Ophiuchus is usually said to represent Asclepius, the Greek god of medicine, and is

P. Murdin

2000-01-01

180

Asclepius, Caduceus, and Simurgh as Medical Symbols Part I  

Microsoft Academic Search

This is the first of two articles reviewing the history of medical symbols. In this first article I have briefly reviewed the evolution of the Greek god, Asclepius, (and his Roman counterpart Aesculapius) with the single serpent entwined around a wooden rod as a symbol of western medicine and have alluded to the misplaced adoption of the Caduceus of the

Touraj Nayernouri

181

Finite-difference, time-domain analysis of a folded acoustic transmission line  

Microsoft Academic Search

Recently designed, modern versions of renaissance woodwind instruments such as the recorder and serpent use square cross sections and a folded acoustic transmission line. Conventional microwave techniques would expect that this bend would cause unwanted reflections and impedance discontinuities. This paper analyses the folded acoustic transmission line using finite-difference, time-domain techniques and shows that the discontinuity can be compensated with

Charles M. Jackson

2005-01-01

182

The Dissent of the Governors  

Microsoft Academic Search

In Adam, Eve, and the Serpent, Elaine Pagels discusses the tribulations of the early Christian church, when its members were tom by the effort to satisfy simultaneously two arguably inconsistent strands of teaching. The first strand taught that it was wrong to engage in homosexuality, promiscuity, abortion, infanticide, and contraception—in short, that it was wrong to enter into sexual relationships

Stephen L. Carter

1989-01-01

183

Lady Kaede in Kurosawa's Ran : verbal and visual characterization through animal traditions  

Microsoft Academic Search

This article deals with the characterization of the unique figure of Lady Kaede in Kurosawa's film Ran from within Japanese cultural syncretism, through using different verbal and visual elements of two animals - fox and serpent. The Japanese fox has always played a most important part in Japanese culture, and its ambivalent nature has become a leitmotiv, especially its supernatural

Zvika Serper

2001-01-01

184

Islands and despots  

Microsoft Academic Search

This paper challenges a conventional wisdom: that when discussing political systems, small is democratic. And yet, can there be paradises without serpents? The presumed manageability of small island spaces promotes and nurtures dispositions for domination and control over nature and society. In such dark circumstances, authoritarian rule is a more natural fit than democracy. By adopting an inter-disciplinary perspective, this

Godfrey Baldacchino

2012-01-01

185

Clip and Save.  

ERIC Educational Resources Information Center

Provides information about the artist Katsukawa Shuntei and his artwork entitled "The Warrior Egara no Heita Battling with the Giant Serpent" that is a wood-block print. Describes how block prints are created and offers learning activities. Includes background information on the artwork. (CMK)

Hubbard, Guy

2003-01-01

186

Haematopoietic effects induced in mice by the snake venom toxin jararhagin  

Microsoft Academic Search

Venom toxins have been tested as anti-thrombotic, and anti-metastatic drugs in experimental models. The jararhagin toxin, from Bothrops jararaca snake venom, acts upon several biological processes, as inflammation, pain, platelet aggregation, etc. In this article, the systemic effects of intra-peritoneal injections of different jararhagin doses were determined in mice. About 50% significant decrease was observed in total blood leukocytes in

D. A Maria; R. C Vassão; I. R. G Ruiz

2003-01-01

187

The effect of post-translational modifications on the hemorrhagic activity of snake venom metalloproteinases  

Microsoft Academic Search

Metalloproteinases (MPs) are Zn+-dependent endoproteolytic enzymes, abundant in crotalid and viperid snake venoms. Most snake venom metalloproteinases (svMPs) are active on extracellular matrix components and this effect is thought to result in bleeding as a consequence of the basement membrane disruption in capillaries. Jararhagin and ACLH are hemorrhagic svMPs from Bothrops jararaca and Agkistrodon contortrix laticinctus venom, respectively. Both enzymes

L. T Garc??a; L. T Parreiras e Silva; O. H. P Ramos; A. K Carmona; P. A Bersanetti; H. S Selistre-de-Araujo

2004-01-01

188

Proteomic profiling of snake venom metalloproteinases (SVMPs): insights into venom induced pathology.  

PubMed

Bothrops sp. snakebites account for the majority of envenomations in South and Central America. Bothrops jararaca accidents are characterized by edema, hemorrhage and necrosis, mainly attributed to the action of hemorrhagic snake venom metalloproteinases (SVMPs). Interestingly, accidents involving Bothrops lanceolatus (Fer-de-Lance) have a prothrombotic profile with necrosis and hemorrhage rarely reported. Here we describe biochemical and proteomic approaches to compare the venom composition of these snakes, focusing on the presence and activity of SVMPs. The total relative amount of SVMPs was found to be approximately the same in the venom of both species, the difference being in the distribution of SVMPs subgroups. Fer-de-Lance venom has relatively more PI SVMPs peptides identified (23-16%) while Jararaca venom has a higher amount of PIII SVMPs (54-43%). Gelatinolytic activity in the PIII mass range is also higher in Jararaca venom. Interestingly, the homologous band region in the Fer-de-Lance zymogram was only very weakly gelatinolytic. According to these findings it is feasible that the different distribution of SVMPs subgroups and their particular biochemical and pharmacological characteristics are two of the main factors contributing to these two radically different venom induced pathologies. PMID:19539639

Terra, Renata M S; Pinto, Antônio F M; Guimarães, Jorge A; Fox, Jay W

2009-06-17

189

Antibody from mice immunized with DNA encoding the carboxyl-disintegrin and cysteine-rich domain (JD9) of the haemorrhagic metalloprotease, Jararhagin, inhibits the main lethal component of viper venom.  

PubMed

Envenoming by the Brazilian pit viper, Bothrops jararaca, induces extensive local and systemic haemorrhage in humans. The severe and occasionally lethal outcome of envenoming is prevented only by administration of antivenom which is conventionally prepared by hyperimmunization of large animals with an individual venom or a range of venoms. Since snake venoms typically consist of numerous molecules, only some of which are toxic, antivenoms are antigenically crude preparations whose therapeutic value would theoretically be enhanced by restricting antibody specificity to toxic venom molecules. We report here that high-titre IgG antibody from mice immunized by the GeneGun with DNA encoding the carboxy-terminal JD9 domain of Jararhagin, a haemorrhage-inducing metalloprotease in B. jararaca venom, extensively neutralized the main lethal component of B. jararaca venom. This is to our knowledge the first study to apply DNA-based methods to preparation of antivenom; it represents a novel approach with greater immunological specificity and fewer hazards than conventional systems of antivenom production. PMID:10931154

Harrison, R A; Moura-Da-Silva, A M; Laing, G D; Wu, Y; Richards, A; Broadhead, A; Bianco, A E; Theakston, R D

2000-08-01

190

Isolation and characterization of two disintegrins inhibiting ADP-induced human platelet aggregation from the venom of Crotalus scutulatus scutulatus (Mohave Rattlesnake)  

Microsoft Academic Search

Disintegrins and disintegrin-like proteins are molecules found in the venom of four snake families (Atractaspididae, Elapidae, Viperidae, and Colubridae). The disintegrins are nonenzymatic proteins that inhibit cell–cell interactions, cell–matrix interactions, and signal transduction, and may have potential in the treatment of strokes, heart attacks, cancers, and osteoporosis. Prior to 1983, the venom of Crotalus scutulatus scutulatus (Mohave Rattlesnake) was known

Elda E. Sánchez; Jacob A. Galán; William K. Russell; Julio G. Soto; David H. Russell; John C.. Perez

2006-01-01

191

Horizontal transfer of non-LTR retrotransposons in vertebrates  

Microsoft Academic Search

Since their discovery in family Bovidae (bovids), Bov-B LINEs, believed to be order-specific SINEs, have been found in all\\u000a ruminants and recently also in Viperidae snakes. The distribution and the evolutionary relationships of Bov-B LINEs provide\\u000a an indication of their origin and evolutionary dynamics in different species. The evolutionary origin of Bov-B LINE elements\\u000a has been shown unequivocally to be

Dušsan Kordišs; Franc Gubenšsek

1999-01-01

192

Understanding the in vitro neuromuscular activity of snake venom Lys49 phospholipase A 2 homologues  

Microsoft Academic Search

Phospholipases A2 (PLA2s) with a lysine substituting for the highly conserved aspartate 49, Lys49 PLA2 homologues, are important myotoxic components in venoms from snakes of Viperidae family. These proteins induce conspicuous myonecrosis by a catalytically-independent mechanism. Traditionally, the Lys49 PLA2 homologues are classified as non-neurotoxic myotoxins given their inability to cause lethality or paralytic effects when injected in vivo, even

M. Gallacci; W. L. G. Cavalcante

2010-01-01

193

REVISED SYSTEMATICS OF TAIWANESE VIPERID SNAKES AND THE CORRELATION TO VENOM DIVERSITY AND EVOLUTION  

Microsoft Academic Search

The major viperid snakes present in Taiwan today are: Daboia russelli siamensis, Deinagkistrodon acutus, Protobothrops mucrosquamatus, Trimeresurus stej- negeri, Ovophis monticola and Ovophis gracilis. As suggested by the species trees deduced from mtDNA sequences of the family Viperidae, these species apparently belong to five different genera. Molecular cloning, N-terminal sequencing, and mass spectrometry have facilitated the sequence-determination of venom proteins.

INN-HO TSAI

2005-01-01

194

The complete mitochondrial DNA sequence of Crotalus horridus (timber rattlesnake).  

PubMed

The complete mitogenome of the timber rattlesnake (Crotalus horridus) was completed using Sanger sequencing. It is 17,260 bp with 13 protein-coding genes, 21 tRNAs, two rRNAs and two control regions. Gene synteny is consistent with other snakes with the exception of a missing redundant tRNA (Ser) . This mitogenome should prove to be a useful addition of a well-known member of the Viperidae snake family. PMID:22994371

Hall, Jacob B; Cobb, Vincent A; Cahoon, A Bruce

2012-09-20

195

Gene induction following wounding of wild-type versus macrophage-deficient Drosophila embryos  

PubMed Central

By using a microarray screen to compare gene responses after sterile laser wounding of wild-type and ‘macrophageless' serpent mutant Drosophila embryos, we show the wound-induced programmes that are independent of a pathogenic response and distinguish which of the genes are macrophage dependent. The evolutionarily conserved nature of this response is highlighted by our finding that one such new inflammation-associated gene, growth arrest and DNA damage-inducible gene 45 (GADD45), is upregulated in both Drosophila and murine repair models. Comparison of unwounded wild-type and serpent mutant embryos also shows a portfolio of ‘macrophage-specific' genes, which suggest analogous functions with vertebrate inflammatory cells. Besides identifying the various classes of wound- and macrophage-related genes, our data indicate that sterile injury per se, in the absence of pathogens, triggers induction of a ‘pathogen response', which might prime the organism for what is likely to be an increased risk of infection.

Stramer, Brian; Winfield, Mark; Shaw, Tanya; Millard, Thomas H; Woolner, Sarah; Martin, Paul

2008-01-01

196

A botanical perspective on the identity of soma ( Nelumbo nucifera Gaertn.) based on scriptural and iconographic records  

Microsoft Academic Search

An examination of the mythic and artistic records of India and Southeast Asia indicates that the famous psychotropic of the\\u000a ancient Aryans was the eastern lotus, Nelumbo nucifera. Vedic epithets, metaphors, and myths that describe the physical and behavioral characteristics of the ‘soma’ plant as a\\u000a sun, serpent, golden eagle, arrow, lightning bolt, cloud, phallic pillar, womb, chariot, and immortal

Andrew McDonald

2004-01-01

197

Vascularized Bone Marrow Transplantation  

Microsoft Academic Search

The classic description of the Chimera since the days of ancient Greece dating to Homer was a beast with the head of a lion,\\u000a the body of a goat, and the tail of a serpent. The concept of this mythical creature — one animal made from parts of others\\u000a — remained the epitome of modern transplantation, symbolizing the American Society

Chau Y. Tai; Louise F. Strande; Hidetoshi Suzuki; Martha S. Matthews; Chad R. Gordon; Charles W. Hewitt

198

Introduction – Historical Perspective  

Microsoft Academic Search

“She was of divine race, not of men, in the fore part a lion, in the hinder a serpent, and in the middle a goat, breathing\\u000a forth in terrible manner the force of blazing fire….” This description by Homer of the mythical creature called Chimera is\\u000a one of the first known bibliographic references supporting the idea of beings made out

Georgios Katsanos; Vincent Donckier

199

Fast implementations of secret-key block ciphers using mixed inner- and outer-round pipelining  

Microsoft Academic Search

The new design methodology for secret-key block ciphers, based on introducing an optimum number of pipeline stages inside of a cipher round is presented and evaluated. This methodology is applied to five well-known modern ciphers, Triple DES, Rijndael, RC6, Serpent, and Twofish, with the goal to first obtain the architecture with the optimum throughput to area ratio, and then the

Pawel Chodowiec; Po Khuon; Kris Gaj

2001-01-01

200

Cryptanalysis of Block Ciphers with Overdefined Systems of Equations  

Microsoft Academic Search

Severalrecentlyproposedciphers,forexampleRijndaeland Serpent, are built with layers of small S-boxes interconnected by linear key-dependentlayers.Theirsecurityreliesonthefact,thattheclassical methodsofcryptanalysis(e.g.linearordifierentialattacks)arebasedon probabilistic characteristics, which makes their security grow exponen- tially withthe numberof rounds Nr. In this paper we study the security of such ciphers under an additional hypothesis: the S-box can be described by an overdeflned system of al- gebraic equations (true with probability 1). We show

Nicolas T. Courtois; Josef Pieprzyk

2002-01-01

201

The history of the evil eye and its influence on ophthalmology, medicine and social customs  

Microsoft Academic Search

Belief in the evil eye is one of the oldest and most widespread superstitions in the world. The concept of the evil eye has\\u000a influenced present day ophthalmology, medicine, and social customs. Oculus sinister (OS), the serpent and the staff of Asclepius,\\u000a the symbol of RX, and many social customs are historically related to the evil eye.

George H. Bohigian

1997-01-01

202

Ophiuchus  

NASA Astrophysics Data System (ADS)

(the Serpent-bearer; abbrev. Oph, gen. Ophiuchi; area 948 sq. deg.) An equatorial constellation which lies between Hercules and Scorpius, and culminates at midnight in mid-June. The ecliptic cuts across the southern part of Ophiuchus, but the constellation is not included among the constellations of the zodiac. Ophiuchus is usually said to represent Asclepius, the Greek god of medicine, and is sh...

Murdin, P.

2000-11-01

203

Finite-difference, time-domain analysis of a folded acoustic transmission line.  

PubMed

Recently designed, modern versions of renais sance woodwind instruments such as the recorder and serpent use square cross sections and a folded acoustic transmission line. Conventional microwave techniques would expect that this bend would cause unwanted reflections and impedance discontinuities. This paper analyses the folded acoustic transmission line using finite-difference, time-domain techniques and shows that the discontinuity can be compensated with by the use of a manufacturable method. PMID:15857045

Jackson, Charles M

2005-03-01

204

Effect of suramin on myotoxicity of some crotalid snake venoms.  

PubMed

We investigated the protective effect of suramin, an enzyme inhibitor and an uncoupler of G protein from receptors, on the myotoxic activity in mice of different crotalid snake venoms (A.c. laticinctus, C.v. viridis, C.d. terrificus, B. jararacussu, B. moojeni, B. alternatus, B. jararaca, L. muta). Myotoxicity was evaluated in vivo by injecting im the venoms (0.5 or 1.0 mg/kg) dissolved in physiological saline solution (0.1 ml) and measuring plasma creatine kinase (CK) activity. Two experimental approaches were used in mice (N = 5 for each group). In protocol A, 1 mg of each venom was incubated with 1.0 mg suramin (15 min, 37 degrees C, in vitro), and then injected im into the mice at a dose of 1.0 mg/kg (in vivo). In protocol B, venoms, 1.0 mg/kg, were injected im 15 min prior to suramin (1.0 mg/kg, iv). Before and 2 h after the im injection blood was collected by orbital puncture. Plasma was separated and stored at 4 degrees C for determination of CK activity using a diagnostic kit from Sigma. Preincubation of some venoms (C.v. viridis, A.c. laticinctus, C.d. terrificus and B. jararacussu) with suramin reduced (37-76%) the increase in plasma CK, except for B. alternatus, B. jararaca or L. muta venoms. Injection of suramin after the venom partially protected (34-51%) against the myotoxicity of B. jararacussu, A.c. laticinctus and C.d. terrificus venom, and did not protect against C.v. viridis, L. muta, B. moojeni, B. alternatus or B. jararaca venoms. These results show that suramin has an antimyotoxic effect against some, but not all the North and South American crotalid snake venoms studied here. PMID:12045838

Arruda, E Z; Silva, N M V; Moraes, R A M; Melo, P A

2002-06-01

205

Frequency and effort of reproduction in female Vipera aspis from a southern population  

NASA Astrophysics Data System (ADS)

The frequency of reproduction of the asp viper ( Vipera aspis, Viperidae) was studied in a population living along the coasts of central Italy. An annual reproductive cycle seemed to be the rule during the 5-year study period. Annual reproduction, high average mass of reproductive females, and large size of neonates, compared with other northern or continental populations, are presumably due to the particularly suitable climatic conditions of the area, as in most coastal habitats of the Mediterranean region. Such a scenario should influence the extent of the feeding period, which allows females, within a few months after parturition, to regain their previous body condition and reproduce again the following year.

Zuffi, Marco A. L.; Giudici, Federico; Ioalè, Paolo

1999-11-01

206

Timeline of key events in snake venom metalloproteinase research.  

PubMed

It is reasonable to state that snake venom toxinology has been actively pursued for at least the past 400 to 500 years. Early on it was appreciated that the venoms of the Viperidae produced profound local effects, notably hemorrhage. For the past 100 years, with the advent of modern chemistry and biochemistry significant progress has been gained regarding the function, structure and role of the snake venom metalloproteinases (SVMPs) in viperid venom pathogenesis. In this review we provide a concise, chronological presentation of the key significant studies that have led to our current understanding of these intriguing toxins. PMID:19344655

Fox, Jay W; Serrano, Solange M T

2009-01-21

207

Reference toxins for antivenin standardization*  

PubMed Central

Potency determinations in mice of venom samples from snakes of the species Bothrops jararaca, which had been caught in an area of less than 10 000 km2, gave the following principal results: (1) Various methods of drying—i.e., closed and continuous vacuum-drying at 5° and 37°C and freeze-drying (lyophilization)—had no different effect on the potency of venoms. (2) Venom samples which display no differences in the final results of intravenous assay may be distinguishable if the observation time is limited to one or two hours. (3) Venom samples obtained from snakes caught no more than about 50 km apart may be of different potencies. (4) Different titres may be obtained for an antivenin, if different samples of venom from the same snake species are employed as reference preparations in the assay. From physiological experiments on dogs and rabbits, in conjunction with observations made in tests on mice, it is evident that B. jararaca venom causes death in circulatory collapse through a mechanism which is as yet unknown. Two physiologically (and probably immunologically) distinct hypotensory factors seem to be present in this venom. The conclusions drawn from the investigation is that consistent and reproducible reference preparations of snake venoms for antivenin assay can probably be obtained only from snakes that are bred and kept in captivity under constant environmental conditions.

Schottler, W. H. A.

1958-01-01

208

Viper metalloproteinase (Agkistrodon halys pallas) with antimicrobial activity against multi-drug resistant human pathogens.  

PubMed

Metalloproteinases are abundant enzymes in crotalidae and viperidae snake venoms. Snake venom metalloproteinases (SVMPs) comprise a family of zinc-dependent enzymes, which display many different biological activities. A 23.1 kDa protein was isolated from Agkistrodon halys (pallas, Chinese viper) snake venom. The toxin is a single chain polypeptide with a molecular weight of 23146.61 and an N-terminal sequence (MIQVLLVTICLAVFPYQGSSIILES) relatively similar to that of other metalloprotein-like proteases isolated from the snake venoms of the Viperidae family. The antibacterial effect of Agkistrodon halys metalloproteinase (AHM) on Burkholderia pseudomallei (strains TES and KHW), Escherichia coli, Enterobacter aerogenes, Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacterium) was studied at a concentration 120 microM. Interestingly, we found that the metalloproteinase exhibited antibacterial properties and was more active against S. aureus, P. vulgaris, P. mirabilis and multi-drug resistant B. pseudomallei (strain KHW) bacteria. AHM variants with high bacteriostatic activity (MIC 1.875-60 microM) also tended to be less cytotoxic against U-937 human monocytic cells up to 1 mM concentrations. These results suggest that this metalloprotein exerts its antimicrobial effect by altering membrane packing and inhibiting mechanosensitive targets. PMID:18297685

Samy, Ramar Perumal; Gopalakrishnakone, Ponnampalam; Chow, Vincent T K; Ho, Bow

2008-07-01

209

Extremely low nerve growth facior (NGF) activity of sea snake (Hydrophiidae) venoms.  

PubMed

Sea snake venoms contain less protein than those of land snakes (Toom et al., 1969). Sea snake venoms lack arginine ester hydrolyzing activity, whereas those of Crotalidae and Viperidae have such activity (Tu et al., 1966). Sea snakes live in salty water, and their venoms may be different from those of land snakes. Because of the difficulty in obtaining sea snake venoms, information about sea snake venoms is quite incomplete. NGF is commonly present in the venoms of land snakes such as Elapidae, Viperidae, and Crotalidae (Cohen and Levi-Montalcini, 1956; Lipps, 2002). It is therefore of interest to investigate the presence or absence of NGF in sea snake venoms. In order to investigate the presence or absence of NGF, five sea snake venoms were selected. Lapemis hardwickii (Hardwick's sea snake) and Acalyptophis peronii venom were obtained from the Gulf of Thailand. Hydrophis cyanocinctus (common sea snake) and Enhydrina schistosa (beaked sea snake) venom were obtained from the Strait of Malacca. Laticauda semifasciata (broad band blue sea snake) venom was also examined and the venom was obtained from Gato Island in the Philippines. PMID:12503884

Mariam, Khafizova; Tu, Anthony T

2002-12-01

210

Abati's work on the amazing nature of the viper and its miraculous powers.  

PubMed

For centuries since Herodotus, writings on those "footless lizards" touched on serpents, their types, appearance, habitat, anatomy external and internal, physiology, reproduction and venomy. However, the status of information remained much the same from Aristotle (B.C. IV) to Coiter (A.D. XVI). In 1589 a new era began with the publication of a book by Baldo Angelo Abati. Its factual illustrations, the first to depict the viper's internal anatomy, were soon republished, in part confirmed and in part contradicted, generally agreed upon by late 1600. PMID:2048145

Knoefel, P K

1991-01-01

211

A Serrate-expressing signaling center controls Drosophila hematopoiesis  

PubMed Central

The differentiation of Drosophila blood cells relies on a functional hierarchy between the GATA protein, Serpent (Srp), and multiple lineage-specific transcription factors, such as the AML1-like protein, Lozenge (Lz). Two major branches of Drosophila hematopoiesis give rise to plasmatocytes/macrophages and crystal cells. Serrate signaling through the Notch pathway is critical in the regulation of Lz expression and the specification of crystal cell precursors, thus providing a key distinction between the two lineages. The expression of Serrate marks a discrete cluster of cells in the lymph gland, a signaling center, with functional similarities to stromal signaling in mammalian hematopoiesis.

Lebestky, Tim; Jung, Seung-Hye; Banerjee, Utpal

2003-01-01

212

Explicit temperature treatment in Monte Carlo neutron tracking routines - First results  

SciTech Connect

This article discusses the preliminary implementation of the new explicit temperature treatment method to the development version Monte Carlo reactor physics code Serpent 2 and presents the first practical results calculated using the method. The explicit temperature treatment method, as introduced in [1], is a stochastic method for taking the effect of thermal motion into account on-the-fly in a Monte Carlo neutron transport calculation. The method is based on explicit treatment of the motion of target nuclei at collision sites and requires cross sections at 0 K temperature only, regardless of the number of temperatures in the problem geometry. The method includes a novel capability of modelling continuous temperature distributions. Test calculations are performed for two test cases, a PWR pin-cell and a HTGR system. The resulting k{sub eff} and flux spectra are compared to a reference solution calculated using Serpent 1.1.16 with Doppler-broadening rejection correction [2]. The results are in very good agreement with the reference and also the increase in calculation time due to the new method is on acceptable level although not fully insignificant. On the basis of the current study, the explicit treatment method can be considered feasible for practical calculations. (authors)

Tuomas, V.; Jaakko, L. [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT (Finland)

2012-07-01

213

Diving Down in Partnership - Technology assists science outreach  

NASA Astrophysics Data System (ADS)

Advances in underwater technology are revealing a world hitherto unseen - the deep ocean. Advances in web technology are enabling scientists to share their discoveries with the world. Underwater robot cameras are allowing scientists to observe animal behaviour and study habitats at depths of 6000 metres. And the Internet is providing a window on this exotic world for everyone with access to the web. The UK's National Oceanography Centre, Southampton operates Isis, a scientific deep-diving remotely-operated vehicle (ROV). The results are phenomenal, producing footage of life in the abyss and the ability to take samples and conduct experiments on the ocean floor. The Centre also hosts a novel project making use of the robot cameras used in the oil and gas industry for maintenance and exploration. Scientists are using this equipment during stand-by time to study animals in their own habitat. The SERPENT project - Scientific and Environmental ROV Partnership using Existing industrial Technology - is an international collaboration with industry, academia and museums. The SERPENT website is updated with the latest information and images attracting some 2000 visitors a month, which is set to rise with recent web developments. A vital part of the Centre's role is communication with the public to increase awareness of the marine environment. Images are essential for outreach especially as audiences continue to seek pictures from remote and inaccessible locations. This talk will explore how TV and the Internet are changing science outreach and the new challenges that it brings.

Marshall-Brown, K.

2009-04-01

214

Is Continuing Contumely Relative to Mc Leod's Vision and ``Secret Sacred Science, (SSS),'': Contagiously Counterproductive in Science, or an Unhealthy Artifact of ``Turf Wars''?  

NASA Astrophysics Data System (ADS)

Mc Leod confirmed, with physics, his models for vision, and for electromagnetic artifacts, by traditional methods, associated with phenomena like tornados, hurricanes, and earthquakes. The latter confirmations are evidently apparent across current ethnology, cultures, linguistics, religion, rituals, exotic astronomy, somewhat concealed evidence of native record-keeping/writing, and iconography. Use of cultural anthropology while observing a modern Peruvian sacred-site-sweeping at Cuzco, coupled with their assertion that Ñari Huallac means ``serpent God,'' plus electromagnet information, reveals that their religious world-view include(s)(d) applied science that is still otherwise unacknowledged. Alexander Thom's precise megalithic site-measurements also imply that ``The Ancients' Serpent'' made/makes precise tracks that convey valuable information. The linguistics of words like Seminole, and unusual visual effects, reveal some traditionalists have done better than most scientists, for vision, and observational physics, and earth science. Tornado and hurricane tracks are predictable, as are some earthquakes. Tornado ``detuning'' or shutdown is electromagnetically possible. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NES07.C2.7

Leod, Roger

2007-04-01

215

On the modeling of snake venom serine proteinase interactions with benzamidine-based thrombin inhibitors  

PubMed Central

Pit viper venoms contain a number of serine proteinases that exhibit one or more thrombin-like activities on fibrinogen and platelets, this being the case for the kinin-releasing and fibrinogen-clotting KN-BJ from the venom of Bothrops jararaca. A three-dimensional structural model of the KN-BJ2 serine proteinase was built by homology modeling using the snake venom plasminogen activator TSV-PA as a major template and porcine kallikrein as additional structural support. A set of intrinsic buried waters was included in the model and its behavior under dynamic conditions was molecular dynamics simulated, revealing a most interesting similarity pattern to kallikrein. The benzamidine-based thrombin inhibitors ?-NAPAP, 3-TAPAP, and 4-TAPAP were docked into the refined model, allowing for a more insightful functional characterization of the enzyme and a better understanding of the reported comparatively low affinity of KN-BJ2 toward those inhibitors.

Henriques, Elsa S.; Fonseca, Nelson; Ramos, Maria Joao

2004-01-01

216

High-level expression, purification, characterization and structural prediction of a snake venom metalloproteinase inhibitor in Pichia pastoris.  

PubMed

Snake venom metalloproteinase inhibitor BJ46a is from the serum of the venomous snake Bothrops jararaca. It has been proven to possess the capacity to inhibit matrix metalloproteinases (MMPs), likely based on its structural similarity to MMPs. This report describes the successful expression, purification, and characterization of the recombinant protein BJ46a in Pichia pastoris. Purified recombinant protein BJ46a was found to inhibit MMPs. Structural modeling was completed and should provide the foundation for further functional research. To our knowledge, this is the first report on the large scale expression of BJ46a, and it provides promise as a method for generation of BJ46a and investigation of its potential use as a new drug for treatment of antitumor invasion and metastasis. PMID:22307654

Shi, Yi; Ji, Ming-Kai; Xu, Jian-Wen; Lin, Xu; Lin, Jian-Yin

2012-03-01

217

Malformations in neotropical viperids: qualitative and quantitative analysis.  

PubMed

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 vipers were identified from 4,087 births (2.3%), while 36 malformed rattlesnakes were found from 324 births (11.1%). Spinal abnormalities were the most common in both species, followed by fusion of ventral scales. Pit vipers showed a greater range of malformations including schistosomia (22.1%), kinked tail (13.7%), bicephaly (3.1%) and hydrocephaly (2.1%). PMID:23885804

Sant'anna, S S; Grego, K F; Lorigados, C A B; Fonseca-Pinto, A C B C; Fernandes, W; Sá-Rocha, L C; Catão-Dias, J L

2013-07-23

218

[A survey on the venomous snakes of the vicinity of Kindia (Guinea) and considerations on the treatment of snakebite].  

PubMed

Between June and December 2004, snake collections were undertaken in eight villages of the vicinity of Kindia, an area of Guinea Conakry where the incidence of snakebite is among the highest reported in the world. A total of 916 specimens were collected, including 90 Elapidae (9.8 %) and 174 Viperidae (19.0%). The Black Mamba Dendroaspis polylepis was represented by eight specimens, i.e. almost 1% of the snakes collected. This species, which is considered as very rare in West Africa, appears common in this area of Guinea. The current difficulties for the treatment of snakebite due to the high increase of the cost of antivenom therapy are discussed. PMID:19499730

Baldé, M C; Mané, Y; Trape, J F

2009-02-01

219

Wide distribution of cysteine-rich secretory proteins in snake venoms: isolation and cloning of novel snake venom cysteine-rich secretory proteins.  

PubMed

Cysteine-rich secretory proteins (CRISPs) are found in epididymis and granules of mammals, and they are thought to function in sperm maturation and in the immune system. Recently, we isolated and obtained clones for novel snake venom proteins that are classified as CRISP family proteins. To elucidate the distribution of snake venom CRISP family proteins, we evaluated a wide range of venoms for immuno-cross-reactivity. Then we isolated, characterized, and cloned genes for three novel CRISP family proteins (piscivorin, ophanin, and catrin) from the venom of eastern cottonmouth (Agkistrodon piscivorus piscivorus), king cobra (Ophiophagus hannah), and western diamondback rattlesnake (Crotalus atrox). Our results show the wide distribution of snake venom CRISP family proteins among Viperidae and Elapidae from different continents, indicating that CRISP family proteins compose a new group of snake venom proteins. PMID:12646276

Yamazaki, Yasuo; Hyodo, Fumiko; Morita, Takashi

2003-04-01

220

Venomous snakebite in Thailand. I: Medically important snakes.  

PubMed

Thailand has an abundance of venomous snakes. Among the neurotoxic family Elapidae, there are three species of the genus Naja (cobras), three of the genus Bungarus (kraits), and the king cobra of the genus Ophiophagus. Other Elapidae snakes in Thailand include sea snakes and Asian coral snakes of the genus Calliophis. They have potent venoms but rarely bite humans. Tissue and hemotoxic snakes are represented by family Viperidae, subfamilies Viperinae and Crotalinae. They remain an occupational hazard for farmers and rubber tappers, causing serious morbidity but only rare deaths, since competent treatment is now widely available throughout Thailand. Purified equine antivenin is manufactured locally for the monocled and Siamese spitting cobras (Naja kaouthia and N. siamensis), king cobra (Ophiophagus hannah), banded krait (Bungarus fasciatus), most green pit vipers (Trimeresurus sp.), Malayan pit viper (Calloselasma rhodostoma), and the Siamese Russell's viper (Daboia russelli siamensis). PMID:9597848

Chanhome, L; Cox, M J; Wilde, H; Jintakoon, P; Chaiyabutr, N; Sitprija, V

1998-05-01

221

Inhibition of Lung Tumor Colonization and Cell Migration with the Disintegrin Crotatroxin 2 Isolated from the Venom of Crotalus atrox  

PubMed Central

Disintegrins are low molecular weight proteins (4-15 kDa) with an RGD binding region at their binding loop. Disintegrin and disintegrin-like proteins are found in the venom of four families of snakes: Atractaspididae, Elapidae, Viperidae and Colubridae. This report describes the biological activity of a disintegrin, crotatroxin 2, isolated by a three-step chromatography procedure from the venom of the Western diamondback rattlesnake (Crotalus atrox). The intact molecular mass for crotatroxin 2 was 7.384 kDa and 71 amino acids. Crotatroxin 2 inhibited human whole blood platelet aggregation with an IC50 of 17.5 nM, inhibited cell (66.3p) migration by 63%, and inhibited experimental lung tumor colonization in BALB/c mice at 1000 ?g/kg. Our data suggest that while crotatroxin 2 inhibits platelet aggregation, cancer cell migration, and lung tumor colonization it is done via different integrins.

Galan, Jacob A.; Sanchez, Elda E.; Rodriguez-Acosta, Alexis; Soto, Julio G.; Bashir, Sajid; McLane, Mary Ann; Paquette-Straub, Carrie; Perez, John C.

2009-01-01

222

Snake venom activators of factor X: an overview.  

PubMed

Activators of blood coagulation factor X have been described in the venom of many snake species belonging to the genus Viperidae and Crotalidae as well as from a few Elapid species. Based on the structural and functional properties of purified activating principles, factor X activators are either metalloproteases or serine proteases. The best known activator is RVV-X from Russell's viper (Daboia russelli), a metalloprotease consisting of a heavy chain containing the catalytic domain and two light chains which share homology with C-type lectins and which are thought to exert a regulatory function in the Ca(2+)-dependent activation of factor X. This activator is also one of the best examples of the use of exogenous activators in coagulation research and in addition it is used in many diagnostic research kits. In this paper, an overview is given of the structural and functional properties of snake venom factor X activators thus far described in the literature. PMID:11910189

Tans, G; Rosing, J

223

Biochemical characterization, action on macrophages, and superoxide anion production of four basic phospholipases A2 from Panamanian Bothrops asper snake venom.  

PubMed

Bothrops asper (Squamata: Viperidae) is the most important venomous snake in Central America, being responsible for the majority of snakebite accidents. Four basic PLA2s (pMTX-I to -IV) were purified from crude venom by a single-step chromatography using a CM-Sepharose ion-exchange column (1.5 × 15?cm). Analysis of the N-terminal sequence demonstrated that pMTX-I and III belong to the catalytically active Asp49 phospholipase A2 subclass, whereas pMTX-II and IV belong to the enzymatically inactive Lys49 PLA2s-like subclass. The PLA2s isolated from Panama Bothrops asper venom (pMTX-I, II, III, and IV) are able to induce myotoxic activity, inflammatory reaction mainly leukocyte migration to the muscle, and induce J774A.1 macrophages activation to start phagocytic activity and superoxide production. PMID:23509779

Rueda, Aristides Quintero; Rodríguez, Isela González; Arantes, Eliane C; Setúbal, Sulamita S; Calderon, Leonardo de A; Zuliani, Juliana P; Stábeli, Rodrigo G; Soares, Andreimar M

2012-12-24

224

Antitumoral potential of Tunisian snake venoms secreted phospholipases A2.  

PubMed

Phospholipases type A2 (PLA2s) are the most abundant proteins found in Viperidae snake venom. They are quite fascinating from both a biological and structural point of view. Despite similarity in their structures and common catalytic properties, they exhibit a wide spectrum of pharmacological activities. Besides being hydrolases, secreted phospholipases A2 (sPLA2) are an important group of toxins, whose action at the molecular level is still a matter of debate. These proteins can display toxic effects by different mechanisms. In addition to neurotoxicity, myotoxicity, hemolytic activity, antibacterial, anticoagulant, and antiplatelet effects, some venom PLA2s show antitumor and antiangiogenic activities by mechanisms independent of their enzymatic activity. This paper aims to discuss original finding against anti-tumor and anti-angiogenic activities of sPLA2 isolated from Tunisian vipers: Cerastes cerastes and Macrovipera lebetina, representing new tools to target specific integrins, mainly, ?5?1 and ?v integrins. PMID:23509718

Zouari-Kessentini, Raoudha; Srairi-Abid, Najet; Bazaa, Amine; El Ayeb, Mohamed; Luis, Jose; Marrakchi, Naziha

2013-01-31

225

Comparative sex chromosome genomics in snakes: differentiation, evolutionary strata, and lack of global dosage compensation.  

PubMed

Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes evolution. PMID:24015111

Vicoso, Beatriz; Emerson, J J; Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

2013-08-27

226

Formation of Ellerman bombs due to 3D flux emergence  

NASA Astrophysics Data System (ADS)

Aims. We investigate the emergence of a “sea-serpent” magnetic field into the outer solar atmosphere and the connection between undulating fieldlines and formation of Ellerman bombs. Methods: We perform 3D numerical experiments solving the time-dependent and resistive MHD equations. Results: A sub-photospheric magnetic flux sheet develops undulations due to the Parker instability. It rises from the convectively unstable sub-photospheric layer and emerges into the highly stratified atmosphere through successive reconnection events along the undulating system. Brightenings with the characteristics of Ellerman bombs are produced due to reconnection, which occurs during the emergence of the field. At an advanced stage of the evolution of the system, the resistive emergence leads to the formation of long, arch-like magnetic fields that expand into the corona. The enhancement of the magnetic field at the low atmosphere and episodes of emergence of new magnetic flux are also discussed.

Archontis, V.; Hood, A. W.

2009-12-01

227

Snake egg immunoglobulins: biochemical characteristics and adjusted isolation procedure.  

PubMed

Transmission of specific immunoglobulins from mothers to their offspring via the egg is a common phenomenon in egg-laying vertebrates but the occurrence of this phenomenon in reptiles, especially in colubrid snakes, has not been proven until recently. Thus, the essential biochemical characteristics of antibodies deposited in eggs of Elaphe guttata (Colubridae, Serpentes) were studied after isolation of the antibody by precipitation and purification by affinity chromatography and gel filtration, with verification by isoelectric focusing and immunoprecipitation. The immunoglobulin deposited in the eggs of colubrid snakes is a singular, non-truncated IgY antibody in a concentration roughly equal to that in the snake's serum. An efficient method to isolate antibody from snake eggs was developed, based on the PEG precipitation technique of avian yolk immunoglobulins; an unsophisticated protocol for the isolation procedure appropriate for reptile eggs is provided. PMID:15777947

Hassl, Andreas

2005-01-11

228

Hunter-gatherers and other primates as prey, predators, and competitors of snakes.  

PubMed

Relationships between primates and snakes are of widespread interest from anthropological, psychological, and evolutionary perspectives, but surprisingly, little is known about the dangers that serpents have posed to people with prehistoric lifestyles and nonhuman primates. Here, we report ethnographic observations of 120 Philippine Agta Negritos when they were still preliterate hunter-gatherers, among whom 26% of adult males had survived predation attempts by reticulated pythons. Six fatal attacks occurred between 1934 and 1973. Agta ate pythons as well as deer, wild pigs, and monkeys, which are also eaten by pythons, and therefore, the two species were reciprocally prey, predators, and potential competitors. Natural history data document snake predation on tree shrews and 26 species of nonhuman primates as well as many species of primates approaching, mobbing, killing, and sometimes eating snakes. These findings, interpreted within the context of snake and primate phylogenies, corroborate the hypothesis that complex ecological interactions have long characterized our shared evolutionary history. PMID:22160702

Headland, Thomas N; Greene, Harry W

2011-12-12

229

Floridas Miami Tequesta Indian Site, Its Calusa Indian Locations, the Matacumbe Keys, and Orlandos Wikiwa Springs Generate Environmentally Significant EMFs.  

NASA Astrophysics Data System (ADS)

Florida purchased the Tequesta ([Langue] doc Christ Spirit-signal) Indian site along the Miami River site that vigorously pulsates with even minor rainstorms entering or leaving the area. Although there is a laughable chimera of a fountain of youth associated with Ponce de Leons discovery of the Florida peninsula in about AD 1513, the Calusa (Royal Christ Jesus Spirit-signal) Indian Nation has an associated significance with EMF signals they possibly monitored throughout their area of activity. Our efforts have also led to the investigation of cultural and other influences implied by the Matacumbe Keys that indicate a shared commonality of awareness with Native Americans of the northeast such as Metacomet, or regions like Maines Grand Lake Matagamon and its associated electromagnetic Spirit Signal. Wikiwa Springs near Orlando shares much with Massachusetts (adherent of serpent Jesus Christ Spirit-signal) Natick, and New Hampshires Naticook Island. These are the locales of environmentally sensitive instrumentation.

Mac Dougall, Jean S.; Mc Leod, Roger D.; Mc Leod, David M.

2003-10-01

230

Boron concentration in water, sediment and different organisms around large borate deposits of Turkey.  

PubMed

Boron is an essential nutrient for plants and an essential element for many organisms, but can be toxic to aquatic and terrestrial organisms above certain concentrations. The aim of this research was to determine boron concentrations in water, sediment and biotic samples (Gammaridae spp.-Crustacea, Helix sp.-Gastropoda, Donax sp.-Bivalvia, Helobdella sp.-Hirudinae, Ephemeroptera nymph, Chrinomidae larvae, Tipulidae larvae-Insecta, Rana sp.-Amphibia, Natrix sp.-Serpentes, fish sample Leiscus cephalus (Linnaeus, 1758) and leaves of Salix sp.-Salicacea from Seydi Stream (Kirka-Eski?ehir). Our results have shown that boron concentrations of the Seydi Stream water is higher than the Turkish Environmental Guidelines standard (>1 mg L(-1)) and in Europe (mean values typically below 0.6 mg L(-1)). PMID:20352187

Emiro?lu, Ozgür; Ciçek, Arzu; Arslan, Naime; Aksan, Serdar; Rüzgar, Melih

2010-03-30

231

On the Asclepian spirit and the future of psychoanalysis.  

PubMed

The dynamics of the Asclepian myth are analyzed, and generic dynamics of the healing imperative are illustrated. The story teaches much about the early theories and practice of ancient medicine, and originated the healing symbol of the staff and serpent which appears on the emblem of the American Academy. The multi-modal therapeutic approach used at the Asclepia was often climaxed by dream incubation as a centerpiece of the treatment. Dreams from modern physicians in analysis will be introduced to show that while our practice has changed in external trappings, the underlying dynamics of ancient and modern healers reflect a common humanity. Modern therapists have reacquired the use of dreams and invented a new set of explanatory myths. Consideration of future developments leads to linking the "psychosomatic model" of antiquity with the psychopharmacological interventions which are now common-place in psychodynamic psychotherapy. The Asclepian emphasis on spirituality is also finding increasing recognition among psychoanalysts and other scientists. PMID:12064034

Whitehead, Clay C

2002-01-01

232

S. Weir mitchell and his snakes: unraveling the "united web and woof of popular and scientific beliefs".  

PubMed

Although best known as a nineteenth-century neurologist and creator of the rest cure, S. Weir Mitchell was one of the first Americans to engage in large-scale animal experimentation. In 1860 he published Researches Upon the Venom of the Rattlesnake, and in 1886, in collaboration with Dr. Edward T. Reichert, he published Researches Upon the Venoms of Poisonous Serpents. Yet, Mitchell's pioneering work in scientific medicine remains a little known aspect of his career. This essay, based mainly on primary source material, tells the story of Mitchell's medical education and research on venomous snakes in order to reveal the ways myth and metaphor influenced medicine as it was becoming a science. PMID:17629777

Cervetti, Nancy

2007-09-01

233

Did Secret, Sacred Science: ``Kokopelli/Pamola,'' Motivate the Tarratines' Assassination of the Penobscots' Bashaba ca 1615, and Does ``Orono'' Yield Direct Physics Insights?  

NASA Astrophysics Data System (ADS)

``Tarratine'' may share cognate phonetics with Tatoosh, (Makah, Pacific NE), Tuitan, Totonac, (coastal ``neighbors'' of the Aztec), Teedyuscung/Tatiuskundt, (Penn.), Teotihuacan, Tomtomhegan, (``ME'' ca 1781-2), Titikaka/Titicaca, and Tantaquidgeon, (Conn.); the military action that led to the assassination of the Penobscots' Bashaba has explanatory roots tying it to the last raid involving `Indian' military action of the Revolutionary War. ``Turf'' rights influenced conflict imperatives. Preserved linguistic roots have it best: Ñari Huallac, coupled with Arizona, Allagash, Allahpatah, and Orono/Orinoco, indicate traditionalists' information, by recognizing Kokopelli/Pamola/Pele/electromagnetics/EMF, says how nature behaves. Penobscots and modern Peruvian descendants of the Incas have it right: the concealed ``Serpent God'' of their EMF alter ego(s), says their science, (applied physics) is sacred because it ``predicts'' nature, even tinnitus, via ``Rawandagon''! To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NES07.C2.8

Ataide, Italani; de Souza, Beatriz; Pawa Matagamon, Sagamo

2007-04-01

234

Can Portable Technology Capture Subtle Phenomena, Related to Quakes, Hurricanes, Tornados, and Volcanoes, Culturally Reported in the Americas by an Equivalent of ``Kokopelli'' or Ñari Huallac, i.e., the EMF?  

NASA Astrophysics Data System (ADS)

Peruvians who produced the CD ÑARI HUALAC say this name of their home village represents two of their few original words, meaning ``serpent God.'' Arizona, hurricane, mullah, Molocket, Millinocket and Allagash of Maine, Allahpata, and Apalachicola of FL, and Allegheny of PA are some partial cognates for these ancient words. They are culturally detected aspects of the EMF, like Kokopelli, the ``hunchbacked, flute-playing, dancing around'' icon of our southwest. That aspect of `flutes' indicated by tinnitus, and its co-associated symptoms of Meuniere's syndrome, along with the sensation of `pins and needles', signify the rotation of secondary magnetic poles, stimulating nerve endings with their EMF that technology can detect, here and in Brazil. Can they fool us about some religious concepts?

Ataide, Jade; McLeod, Roger

2006-03-01

235

Origins of the ancient constellations: I. The Mesopotamian traditions  

NASA Astrophysics Data System (ADS)

In the sky-map of ancient Babylon, constellations had two different roles, and thus developed into two overlapping traditions. One set of constellations represented the gods and their symbols; the other set represented rustic activities and provided a farming calendar. Many constellations were shared by the two traditions, but in some regions of sky there were alternative divine and rustic figures. These figures developed in stages from ~3200 BC to ~500 BC. Of the divine set, the most important (although the last to be finalised) were the twelve zodiacal signs, plus several associated animals (the serpent, crow, eagle, and fish), which were all transmitted to the classical Greek sky-map that we still use today. Conversely, the rustic constellations of workers and tools and animals were not transmitted to the West. However, a few of them may have survived in Bedouin Arab sky-maps of the first millennium AD.

Rogers, J. H.

1998-02-01

236

[Professor Lev Fyodorovich Ilyin (140th anniversary of the birth)].  

PubMed

At the turn of the XIX-XX centuries significant contribution to the approval authority of the Department of Pharmacy, Military Medical Academy introduced Professor Leo F. Ilyin (1871-1937)--a major domestic scholar and social activist, organizer of military medical supplies, physician by training, pharmacist, dedicated chemist and educator. Research, first launched in Russia by L.F. Ilyin, served as the basis for the production of morsulus--one of the most widely used dosage forms. Many works of L.F. Ilyin, his fellow workers and students are devoted to studying the structure of the active principles, properties and pharmacological action of wild and cultivated medicinal plants in Russia: herbs of marsh gilled, leaves of lobelia and May lily, roots and rootstocks of serpent grass, all-heal, pieplant, licorice, etc. PMID:22332400

Miroshnichenko, Iu V; Kononov, V N; Kostenko, N L

2011-10-01

237

Purification and characterization of islet hormones (insulin, glucagon, pancreatic polypeptide and somatostatin) from the Burmese python, Python molurus  

Microsoft Academic Search

Insulin was purified from an extract of the pancreas of the Burmese python, Python molurus (Squamata:Serpentes) and its primary structure established as: A Chain: Gly-Ile-Val-Glu-Gln-Cys-Cys-Glu-Asn-Thr10-Cys-Ser-Leu-Tyr-Glu-Leu-Glu-Asn-Tyr-Cys20-Asn. B-Chain: Ala-Pro-Asn-Gln-His-Leu-Cys-Gly-Ser-His10-Leu-Val-Glu-Ala-Leu-Tyr-Leu-Val-Cys-Gly20-Asp-Arg-Gly-Phe-Tyr-Tyr-Ser-Pro-Arg-Ser30. With the exception of the conservative substitution Phe?Tyr at position B25, those residues in human insulin that comprise the receptor-binding and those residues involved in dimer and hexamer formation are fully conserved in

J Michael Conlon; Stephen M Secor; Thomas E Adrian; Dennis C Mynarcik; Jonathan Whittaker

1997-01-01

238

We Detect Blue Light Phenomena Correlating with Environmental and Weather Changes, and Historic Native Americans or Their Place Names.  

NASA Astrophysics Data System (ADS)

Katahdin (Christ Cathar Spirit-signal stronghold) in Maine is sacred to the Penobscot Indian Nation. That mountain complex, and areas like Ellis Pond, ME and Penley Hill/Anasagunticook (adherent of Jesus Christ Spirit-signal doctor church) of the Mexico/Rumford/Mountain Valley region, also in Maine, have an association with historic Native Americans like the medicine woman Molocket/Molly Ockett. We have observed that these and other regions generate electromagnetic field (EMF) signals, which we can detect visually and in other ways. Such signals have sometimes been associated with significant and dynamic weather phenomena. Ohio's Serpent Mound and associated regions, or those now occupied by the Hopi Indian Nation, formerly an ancient Anasazi site, or areas of the current and earlier Mayan Nations, or the Nazca Plateau of Peru, may generate signals correlating with climate change, that may impact our technology, as in major power blackouts.

Ochs, Michael Ann; Mc Leod, Roger D.; Mc Leod, Edward M.

2003-10-01

239

Environmental Aspects of Sites Like America's Stonehenge, (AS), Florida's Miami Tequesta Site, and Lowell's A.D. 1069  

NASA Astrophysics Data System (ADS)

Subtle ``instrumentation" is often unnoticed. Stone-chamber transponder-receivers are principle and secondary wave detectors, part of the ``technologic" arsenal of men like Passaconaway/Metacomen of colonial-era Massachusetts, or the earthquake-predicting Shawnee Tecumseh of the Ohio Valley region, during 1811-1813. An Ohio stone-effigy ``serpent" is a thunderstorm precursor signal indicator. The Hopi require similar ``equipment," when duping gullible ``rain-dance" patrons. Tornado/waterspout activity is documented right in the Tequesta site at the river in Miami, Florida, which generates detectable signals. Columbus could have used similar ``secret sacred science" previously learned from American Indians, and thereby successfully predicted an anomalous hurricane on a subsequent trip. These, and the Hawaiian volcano goddess Pelee, seem to be a mythic equivalent of electromagnetically generated signals, i.e., a metaphor for ``environmental applied physics" we detect at A.S.

Ochs, Michael Ann; Mc Leod, Roger D.

2002-04-01

240

Snake Robots.com  

NSDL National Science Digital Library

One of the latest developments in robotics is flexible, snake-like machines that could be used for such activities as Martian landscape exploration because they are highly flexible, adaptable, and maneuverable into tight spaces and over relatively large obstacles. Snake Robots.com comes from robotics engineer Gavin Miller who developed his own "snakes" with inspiration from his work on physically-based computer animation at Alias Research, Inc. and Apple Computer, Inc. (Note: this private site is not affiliated with those corporations.) Visitors to Miller's site can see color videos, with audio, of his incredibly life-like serpents (.mpeg). Links to other snake robot sites are provided along with information about upcoming museum exhibitions and articles.

241

Drosophila E-Cadherin Functions in Hematopoietic Progenitors to Maintain Multipotency and Block Differentiation  

PubMed Central

A fundamental question in stem cell biology concerns the regulatory strategies that control the choice between multipotency and differentiation. Drosophila blood progenitors or prohemocytes exhibit key stem cell characteristics, including multipotency, quiescence, and niche dependence. As a result, studies of Drosophila hematopoiesis have provided important insights into the molecular mechanisms that control these processes. Here, we show that E-cadherin is an important regulator of prohemocyte fate choice, maintaining prohemocyte multipotency and blocking differentiation. These functions are reminiscent of the role of E-cadherin in mammalian embryonic stem cells. We also show that mis-expression of E-cadherin in differentiating hemocytes disrupts the boundary between these cells and undifferentiated prohemocytes. Additionally, upregulation of E-cadherin in differentiating hemocytes increases the number of intermediate cell types expressing the prohemocyte marker, Patched. Furthermore, our studies indicate that the Drosophila GATA transcriptional co-factor, U-shaped, is required for E-cadherin expression. Consequently, E-cadherin is a downstream target of U-shaped in the maintenance of prohemocyte multipotency. In contrast, we showed that forced expression of the U-shaped GATA-binding partner, Serpent, repressed E-cadherin expression and promoted lamellocyte differentiation. Thus, U-shaped may maintain E-cadherin expression by blocking the inhibitory activity of Serpent. Collectively, these observations suggest that GATA:FOG complex formation regulates E-cadherin levels and, thereby, the choice between multipotency and differentiation. The work presented in this report further defines the molecular basis of prohemocyte cell fate choice, which will provide important insights into the mechanisms that govern stem cell biology.

Gao, Hongjuan; Wu, Xiaorong; Fossett, Nancy

2013-01-01

242

Shocked lithologies at the Wanapitei impact structure, Ontario, Canada  

NASA Astrophysics Data System (ADS)

The approx. 7.5 diameter Wanapitei impact structure (46 deg 45 min N; 80 deg 45 min W) lies entirely within Lake Wanapitei in central Ontario, Canada. Impact lithologies are known only from glacial float at the southern end of the lake. Over 50% of the impact lithologies recovered from this float can be classified as suevite, less than 20% as highly shocked and partially melted arkosic metasediments of the target rock Mississagi Formation or, possibly, the Serpent Formation and less than 20% as glassy impact melt rocks. An additional less than 5% of the samples have similarities to the suevite but have up to 50% glass clasts and are tentatively interpreted as fall-back material. The glassy impact melt rocks fall into two textural and mineralogical types: a perlitically fractured, colorless glass matrix variant, with microlites of hypersthene with up to 11.5% Al2O3 and a 'felted' matrix variant, with evidence of flow prior to the crystallization of tabular orthopyroxene. These melt glasses show chemical inhomogeneities on a microscopic scale, with areas of essentially SiO2, even when appearing optically homogeneous. They are similar in bulk composition for major elements, but the felted matrix variant is approx. 5x more enriched in Ni, Co and Cr, the interelement ratios of which are indicative of an admixture of a chondritic projectile. Mixing models suggest that the glassy impact melt rocks can be made from the target rocks in the proportions: approx. 55% Gowganda wacke, approx. 42% Serpent arkose and approx. 3% Nipissing intrusives. Geologic reconstructions suggest that this is a reasonable mixture of potential target rocks at the time of impact.

Grieve, R. A. F.; Ber, T. J.

1994-09-01

243

Jararhagin and its multiple effects on hemostasis.  

PubMed

Jararhagin is a 52 kDa hemorrhagic P-III metalloproteinase isolated from the venom of the medically important Brazilian pit-viper Bothrops jararaca. It is a member of the reprolysin family of zinc metalloproteinases containing a catalytic metalloproteinase domain followed by a disintegrin-like and a cysteine-rich domain. The impact of jararhagin on hemostasis has been extensively studied using in vitro and in vivo model systems as well as in clinical studies. Jararhagin-induced hemorrhage is the result of the degradation of sub-endothelial matrix proteins leading to the disruption of the blood vessel endothelium, with accompanying disturbances in platelet function. The versatility of jararhagin is further demonstrated by its direct action on von Willebrand factor, the degradation of fibrinogen, by its inhibition of platelet adhesion to collagen and by its inability to be affected by the plasma inhibitor alpha(2)-macroglobulin. Collagen-induced platelet aggregation is inhibited by jararhagin though the binding of the molecule to the alpha(2) subunit I domain of the platelet surface alpha(2)beta(1) integrin (collagen receptor). Jararhagin also cleaves the beta(1) subunit of the same integrin, inhibiting platelet interaction and ultimately causing impairment of signal transduction. The effect of jararhagin on cell systems other than platelets is evaluated; in fibroblasts, jararhagin functions as a collagen-mimetic substrate and, in endothelial cells, it causes apoptosis and indirectly inhibits cell proliferation by release of angiostatin-like compounds. Jararhagin induces a strong pro-inflammatory response characterized by intense leukocyte accumulation at the site of the injection. Although hemorrhage and edema are a response to the direct effect of jararhagin, jararhagin-induced inflammation and necrosis are dependent on macrophages and key pro-inflammatory cytokines or their receptors. Some data also indicate that the toxin possesses anti-tumorgenic properties. Methods for inhibiting jararhagin are reviewed; this encompasses the use of synthetic peptides to the isolation of naturally occurring mammalian peptides and the development of toxin-specific antibodies through DNA immunisation and monoclonal antibody technologies. The availability of jararhagin makes it an important tool for research into the mechanisms of action of similar toxins, for insights into cellular interactions and for clinical investigations into the treatment of envenomings from B. jararaca. PMID:15922770

Laing, Gavin D; Moura-da-Silva, Ana M

2005-04-02

244

Pioneers of anti-venomous serotherapy: Dr Vital Brazil (1865-1950).  

PubMed

Dr Vital Brazil was a great humanitarian and pioneer of medical science. His main work arose from his concern with poisonous snakebite accidents to labourers working the land. Vital Brazil estimated that, at the beginning of this century, deaths due to crotaline snakebites in the State of São Paulo, Brazil, were nearly 3000 per year, representing a mortality rate of about 25%, the majority being due to bothropic envenomation. After reading a report of Calmette's anti-Naja serum, Vital Brazil raised monovalent serum against the venom of Bothrops jararaca and the venom of Crotalus durissus terrificus. In 1989 this led to the first demonstration of the specificity of anti-venomous serum and later, the first production of polyvalent serum for therapeutic use. As Director of the newly founded Institute Butantan in São Paulo, Vital Brazil was actively engaged in every aspect of serotherapeutic treatment. This included organizing a unique system of exchanging anti-ophidic serum for snakes as well as a wide-ranging teaching programme. His many outstanding contributions to the fields of immunology, public health, toxinology and herpetology required not only a very high level of observational, deductive and practical ability but also an unswerving vision and sense of duty; this was allied to great administrative skill and exceptional energy. PMID:1519249

Hawgood, B J

245

Snake venom metalloproteinases: structure/function relationships studies using monoclonal antibodies.  

PubMed

Snake Venom Metalloproteinases (SVMPs) are synthesized as zymogens and undergo proteolytic processing resulting in a variety of multifunctional proteins. Jararhagin is a P-III SVMP, isolated from the venom of Bothrops jararaca, comprising metalloproteinase, disintegrin-like and cysteine-rich domains. The catalytic domain is responsible for the hemorrhagic activity. The disintegrin-like/cysteine-rich domains block alpha2beta1 integrin binding to collagen and apparently enhance the hemorrhagic activity of SVMPs. The relevance of disintegrin-like domain is described in this paper using a series of mouse anti-jararhagin monoclonal antibodies (MAJar 1-7). MAJar 3 was the only antibody able to completely neutralize jararhagin hemorrhagic activity. Neutralization of catalytic activity was partial by incubation with MAJar 1. MAJars 1 and 3 efficiently neutralized jararhagin binding to collagen with IC50 of 330 and 8.4 nM, respectively. MAJars 1 and 3 recognized the C-terminal portion of the disintegrin domain, which is apparently in conformational proximity with the catalytic domain according to additivity tests. These data suggest that disintegrin-like domain epitopes are in close contact with catalytic site or functionally modulate the expression of hemorrhagic activity in SVMPs. PMID:14757212

Tanjoni, Isabelle; Butera, Diego; Bento, Luciana; Della-Casa, Maisa S; Marques-Porto, Rafael; Takehara, Harumi A; Gutiérrez, Jose M; Fernandes, Irene; Moura-da-Silva, Ana M

2003-12-01

246

Complete amino-acid sequence, crystallization and preliminary X-ray diffraction studies of leucurolysin-a, a nonhaemorrhagic metalloproteinase from Bothrops leucurus snake venom  

PubMed Central

Leucurolysin-a (leuc-a) is a class P-I snake-venom metalloproteinase isolated from the venom of the South American snake Bothrops leucurus (white-tailed jararaca). The mature protein is composed of 202 amino-acid residues in a single polypeptide chain. It contains a blocked N-terminus and is not glycosylated. In vitro studies revealed that leuc-a dissolves clots made either from purified fibrinogen or from whole blood. Unlike some other venom fibrinolytic metalloproteinases, leuc-a has no haemorrhagic activity. Leuc-a was sequenced and was crystallized using the hanging-drop vapour-diffusion technique. Crystals were obtained using PEG 6000 or PEG 1500. Diffraction data to 1.80 and 1.60?Å resolution were collected from two crystals (free enzyme and the endogenous ligand–protein complex, respectively). They both belonged to space group P212121, with very similar unit-cell parameters (a = 44.0, b = 56.2, c = 76.3?Å for the free-enzyme crystal).

Ferreira, Rodrigo Novaes; Rates, Breno; Richardson, Michael; Guimaraes, Beatriz Gomes; Sanchez, Eladio Oswaldo Flores; de Castro Pimenta, Adriano Monteiro; Nagem, Ronaldo Alves Pinto

2009-01-01

247

The effect of post-translational modifications on the hemorrhagic activity of snake venom metalloproteinases.  

PubMed

Metalloproteinases (MPs) are Zn(+)-dependent endoproteolytic enzymes, abundant in crotalid and viperid snake venoms. Most snake venom metalloproteinases (svMPs) are active on extracellular matrix components and this effect is thought to result in bleeding as a consequence of the basement membrane disruption in capillaries. Jararhagin and ACLH are hemorrhagic svMPs from Bothrops jararaca and Agkistrodon contortrix laticinctus venom, respectively. Both enzymes demonstrate proteolytic activity on fibrinogen and fibronectin and jararhagin inhibits collagen-induced platelet aggregation in vitro. This work describes the expression, purification and successful refolding of the recombinant ACLH zymogen (rPRO-ACLH) as well as the catalytic domain of jararhagin (rCDJARA). The heterologous proteins were produced in E. coli, an in vivo expression system that does not make post-translational modifications. The recombinant refolded proteins did not show any hemorrhagic activity in mice skin, as well as the native deglycosylated jararhagin and ACLH. However, they preserved their proteolytic activity on fibrinogen and fibronectin. It seems that the hemorrhagic properties of these hemorrhagins are dependent on post-translational modifications, whereas their proteolytic activity is not dependent on such modifications. PMID:15313443

García, L T; Parreiras e Silva, L T; Ramos, O H P; Carmona, A K; Bersanetti, P A; Selistre-de-Araujo, H S

2004-05-01

248

Hemorrhagic activity of HF3, a snake venom metalloproteinase: insights from the proteomic analysis of mouse skin and blood plasma.  

PubMed

Hemorrhage induced by snake venom metalloproteinases (SVMPs) is a complex phenomenon resulting in capillary disruption and blood extravasation. The mechanism of action of SVMPs has been investigated using various methodologies however the precise molecular events associated with microvessel disruption remains not fully understood. To gain insight into the hemorrhagic process, we analyzed the global effects of HF3, an extremely hemorrhagic SVMP from Bothrops jararaca, in the mouse skin and plasma. We report that in the HF3-treated skin there was evidence of degradation of extracellular matrix (collagens and proteoglycans), cytosolic, cytoskeleton, and plasma proteins. Furthermore, the data suggest that direct and indirect effects promoted by HF3 contributed to tissue injury as the activation of collagenases was detected in the HF3-treated skin. In the plasma analysis after depletion of the 20 most abundant proteins, fibronectin appeared as degraded by HF3. In contrast, some plasma proteinase inhibitors showed higher abundance compared to control skin and plasma. This is the first study to assess the complex in vivo effects of HF3 using high-throughput proteomic approaches, and the results underscore a scenario characterized by the interplay between the hydrolysis of intracellular, extracellular, and plasma proteins and the increase of plasma inhibitors in the hemorrhagic process. PMID:21939285

Paes Leme, Adriana F; Sherman, Nicholas E; Smalley, David M; Sizukusa, Letícia O; Oliveira, Ana K; Menezes, Milene C; Fox, Jay W; Serrano, Solange M T

2011-10-27

249

Preclinical assessment of the neutralizing capacity of antivenoms produced in six Latin American countries against medically-relevant Bothrops snake venoms.  

PubMed

Species of the genus Bothrops induce the vast majority of snakebite envenomings in Latin America. A preclinical study was performed in the context of a regional network of public laboratories involved in the production, quality control and development of antivenoms in Latin America. The ability of seven polyspecific antivenoms, produced in Argentina, Brazil, Peru, Bolivia, Colombia and Costa Rica, to neutralize lethal, hemorrhagic, coagulant, defibrinogenating and myotoxic activities of the venoms of Bothrops neuwiedi (diporus) (Argentina), Bothrops jararaca (Brazil), B. neuwiedi (mattogrossensis) (Bolivia), Bothrops atrox (Peru and Colombia) and Bothrops asper (Costa Rica) was assessed using standard laboratory tests. Despite differences in the venom mixtures used in the immunization of animals for the production of these antivenoms, a pattern of extensive cross-neutralization was observed between these antivenoms and all the venoms tested, with quantitative differences in the values of effective doses. This study reveals the capacity of these antivenoms to neutralize, in preclinical tests, homologous and heterologous Bothrops venoms in Central and South America, and also highlight quantitative differences in the values of Median Effective Doses (ED50s) between the various antivenoms. PMID:20621114

Segura, A; Castillo, M C; Núñez, V; Yarlequé, A; Gonçalves, L R C; Villalta, M; Bonilla, C; Herrera, M; Vargas, M; Fernández, M; Yano, M Y; Araújo, H P; Boller, M A A; León, P; Tintaya, B; Sano-Martins, I S; Gómez, A; Fernández, G P; Geoghegan, P; Higashi, H G; León, G; Gutiérrez, J M

2010-07-16

250

Angiotensin-converting enzyme and enkephalinase in human breast cyst fluid.  

PubMed Central

Palpable breast cysts with an apocrine epithelial lining (type 1) are reported to be associated with a higher risk of developing breast cancer. The composition of breast cyst fluid (BCF) might include those factors involved in this increased risk. In this study peptidase activities that were active against the substrate [125I]metenkephalin-Arg-Phe were detected in BCF. The products were identified by reversed phase high-performance liquid chromatography (HPLC) as [125I]Tyr-Gly-Gly and [125I]Met-enkephalin. This proteolysis was not inhibited by PCMB, pepstatin A, leupeptin or aprotinin but was by EDTA, showing that the activity was due to metalloproteases. The production of [125I]Try-Gly-Gly was inhibited by phosphoramidon and thiorphan, whereas that of [125I]met-enkephalin was inhibited by captopril and Bothrops jararaca peptide, indicating that these activities are enkephalinase and angiotensin-converting enzyme (ACE) respectively. A fluorometric assay for ACE demonstrated that ACE levels are significantly higher in type 2 BCF than in type 1 BCF (30.8 vs 6.1 nmol hr-1 10 microliters-1, P < 0.001). As the increased risk of cancer is linked to type 1 cysts it is possible that higher levels of peptidase in type 2 BCF reflect a protective environment in the breast in which mitogenic peptide growth factors are neutralised by proteolysis.

Frame, K. L.; Patton, K.; Reed, M. J.; Ghilchik, M. W.; Parish, D. C.

1996-01-01

251

Bothrops snakebite on the head: case report and review of the literature.  

PubMed

A previously healthy, 21-year-old female was admitted 5 h after being bitten in the occipital region by a pitviper presumed to be Bothrops jararaca. Physical examination revealed marked cranial and facial oedema extending to the neck and dorsum, bilateral eyelid ecchymosis, and local conjunctival and gingival bleeding. The patient was alert and complained of mild, local pain and nausea. There were no signs of neurological involvement. The main laboratory findings on admission included incoagulable blood, a platelet count of 4000/microl, and an ELISA-estimated serum venom concentration of 62.6 ng/ml. Sequential serum creatinine, urea nitrogen, sodium and potassium concentrations were normal. The case was classified as severe and, after the intravenous administration of ranitidine, chlorpheniramine and hydrocortisone, the intravenous infusion of 12 vials of undiluted bothropic equine antivenom [F(ab)(2); 10 ml/vial] was initiated. The antivenom infusion was halted after 10 vials because the patient developed a severe early reaction, although this was successfully treated with subcutaneous adrenaline and intravenous hydrocortisone. Platelet replacement (seven units) was performed and 24 h after the antivenom infusion, normal results in blood-coagulation tests and an increase in the platelet count (to 100,000/microl) were observed. No circulating venom was detected in blood samples collected 6, 12, 24 or 48 h post-admission. The patient was discharged after 4 days, with clinical improvement and no signs of local infection, and subsequent follow-up revealed no sequelae. PMID:18028735

Bucaretchi, F; Hyslop, S; Mello, S M; Vieira, R J

2007-12-01

252

Purification and renal effects of phospholipase A(2) isolated from Bothrops insularis venom.  

PubMed

Bothrops insularis venom contains a variety of substances presumably responsible for several pharmacological effects. We investigated the biochemical and biological effects of phospholipase A(2) protein isolated from B. insularis venom and the chromatographic profile showed 7 main fractions and the main phospholipase A(2) (PLA(2)) enzymatic activity was detected in fractions IV and V. Fraction IV was submitted to a new chromatographic procedure on ion exchange chromatography, which allowed the elution of 5 main fractions designated as IV-1 to IV-5, from which IV-4 constituted the main fraction. The molecular homogeneity of this fraction was characterized by high-performance liquid chromatography (HPLC) and demonstrated by mass spectrometry (MS), which showed a molecular mass of 13984.20 Da; its N-terminal sequence presented a high amino acid identity (up to 95%) with the PLA(2) of Bothrops jararaca and Bothrops asper. Phospholipase A(2) isolated from B. insularis (Bi PLA(2) ) venom (10 microg/mL) was also studied as to its effect on the renal function of isolated perfused kidneys of Wistar rats (n=6). Bi PLA(2) increased perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF) and glomerular filtration rate (GFR). Sodium (%TNa(+)) and chloride tubular reabsorption (%TCl(-)) decreased at 120 min, without alteration in potassium transport. In conclusion, PLA(2) isolated from B. insularis venom promoted renal alterations in the isolated perfused rat kidney. PMID:17953979

Machado Braga, Marcus Davis; Costa Martins, Alice Maria; Alves, Claudênio Diógenes; de Menezes, Dalgimar Beserra; Martins, René Duarte; Ferreira Barbosa, Paulo Sérgio; de Sousa Oliveira, Isadora Maria; Toyama, Marcos Hikari; Toyama, Daniela Oliveira; Dos Santos Diz Filho, Eduardo Brito; Ramos Fagundes, Fabio Henrique; Fonteles, Manassés Claudino; Azul Monteiro, Helena Serra

2007-09-11

253

Simultaneous GeneGun immunisation with plasmids encoding antigen and GM-CSF: significant enhancement of murine antivenom IgG1 titres.  

PubMed

GeneGun DNA immunisation is a potent means of inducing antibody-dominant immune responses that we are exploiting to generate venom toxin-specific antibodies to improve the therapy of systemic envenoming by snakes. Here, we report that mice immunised with DNA encoding the carboxyl domain (JD9) of a haemorrhagic Zn metalloprotease (Jararhagin) in venom of the South American pit viper, Bothrops jararaca, and a plasmid expressing murine cytokine granulocyte/macrophage-colony stimulating factor (GM-CSF) raised significantly higher antigen-specific IgG1 titres than mice immunised with JD9 DNA alone. Serological responses to GeneGun JD9 DNA immunisation were shown to be dominated by IgG1, an IgG subclass associated with T lymphocyte helper 2 (Th2) immune responses. Further significant enhancement of JD9-specific IgG1 titres was achieved by increasing the number of immunisations. This report illustrates that DNA immunisation protocols to achieve high-titre, venom toxin-specific antibody production are well advanced and encourage the development of a DNA-based approach to antivenom production. PMID:11906755

Harrison, R A; Richards, A; Laing, G D; Theakston, R D G

2002-03-15

254

Purification and cloning of cysteine-rich proteins from Trimeresurus jerdonii and Naja atra venoms.  

PubMed

Three 26 kDa proteins, named as TJ-CRVP, NA-CRVP1 and NA-CRVP2, were isolated from the venoms of Trimeresurus jerdonii and Naja atra, respectively. The N-terminal sequences of TJ-CRVP and NA-CRVPs were determined. These components were devoid of the enzymatic activities tested, such as phospholipase A(2), arginine esterase, proteolysis, L-amino acid oxidase, 5'nucleotidase, acetylcholinesterase. Furthermore, these three components did not have the following biological activities: coagulant and anticoagulant activities, lethal activity, myotoxicity, hemorrhagic activity, platelet aggregation and platelet aggregation-inhibiting activities. These proteins are named as cysteine-rich venom protein (CRVP) because their sequences showed high level of similarity with mammalian cysteine-rich secretory protein (CRISP) family. Recently, some CRISP-like proteins were also isolated from several different snake venoms, including Agkistrodon blomhoffi, Trimeresurus flavoviridis, Lanticauda semifascita and king cobra. We presumed that CRVP might be a common component in snake venoms. Of particular interest, phylogenetic analysis and sequence alignment showed that NA-CRVP1 and ophanin, both from elapid snakes, share higher similarity with CRVPs from Viperidae snakes. PMID:14529736

Jin, Yang; Lu, Qiumin; Zhou, Xingding; Zhu, Shaowen; Li, Rui; Wang, Wanyu; Xiong, Yuliang

2003-10-01

255

Scales microstructure of snakes from the Egyptian area.  

PubMed

The morphology of many organisms seems to be related to the environments in which they live. Many snakes are so similar in their morphological patterns that it becomes quite difficult to distinguish any adaptive divergence that may have occurred. Many authors have suggested that the microstructure of the reptile's scales has important functional value. Herein, we investigate variations on the micromorphology of the external surface of dorsal scales on the head, the mid-body region (trunk), and the tail of Rhomphotyphlops braminus (Typhlopidae), Eryx jaculus (Boidae), Psammophis sibilans (Colubridae), Naja haje (Elapidae) and Echis carinatus (Viperidae). The specimens were metallized and analyzed by scanning electron microscopy. All species displayed unique dorsal scale surface microstructures of the investigated regions. The microstructural pattern of the scales of head, trunk, and tail differs in different species of these snakes. In conclusion, we detected ecomorphologic relationships between extant dorsal scale microstructures and snake microhabitat, enabling us to hypothesize that environmental pressures have significant influences not only on these animals' macrostructure, but also on its microstructure as well. PMID:23106563

Allam, Ahmed A; Abo-Eleneen, Rasha E

2012-11-01

256

Snake venom metalloproteinases: structure, function and relevance to the mammalian ADAM/ADAMTS family proteins.  

PubMed

Metalloproteinases are among the most abundant toxins in many Viperidae venoms. Snake venom metalloproteinases (SVMPs) are the primary factors responsible for hemorrhage and may also interfere with the hemostatic system, thus facilitating loss of blood from the vasculature of the prey. SVMPs are phylogenetically most closely related to mammalian ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin type-1 motif) family of proteins and, together with them, constitute the M12B clan of metalloendopeptidases. Large SVMPs, referred to as the P-III class of SVMPs, have a modular architecture with multiple non-catalytic domains. The P-III SVMPs are characterized by higher hemorrhagic and more diverse biological activities than the P-I class of SVMPs, which only have a catalytic domain. Recent crystallographic studies of P-III SVMPs and their mammalian counterparts shed new light on structure-function properties of this class of enzymes. The present review will highlight these structures, particularly the non-catalytic ancillary domains of P-III SVMPs and ADAMs that may target the enzymes to specific substrates. This article is part of a Special Issue entitled: Proteolysis 50years after the discovery of lysosome. PMID:21530690

Takeda, Soichi; Takeya, Hiroyuki; Iwanaga, Sadaaki

2011-04-20

257

Biochemical and enzymatic characterization of BpMP-I, a fibrinogenolytic metalloproteinase isolated from Bothropoides pauloensis snake venom.  

PubMed

Snake Venom Metalloproteinases (SVMPs) are the most abundant components present in Viperidae venom. They are important in the induction of systemic alterations and local tissue damage after envenomation. In the present study, a metalloproteinase named BpMPI was isolated from Bothropoides pauloensis snake venom and its biochemical and enzymatic characteristics were determined. BpMPI was purified in two chromatography steps on ion exchange CM-Sepharose Fast flow and Sephacryl S-300. This protease was homogeneous on SDS-PAGE and showed a single chain polypeptide of 20kDa under non reducing conditions. The partial amino acid sequence of the enzyme showed high similarity with other SVMPs enzymes from snake venoms. BpMPI showed proteolytic activity upon azocasein and bovine fibrinogen and was inhibited by EDTA, 1,10 phenanthroline and ?-mercaptoethanol. Moreover, this enzyme showed stability at neutral and alkaline pH and it was inactivated at high temperatures. BpMPI was able to hydrolyze glandular and tissue kallikrein substrates, but was unable to act upon factor Xa and plasmin substrates. The enzyme did not induce local hemorrhage in the dorsal region of mice even at high doses. Taken together, our data showed that BpMP-I is in fact a fibrinogenolytic metalloproteinase and a non hemorrhagic enzyme. PMID:22008900

Naves de Souza, Dayane L; Gomes, Mário Sérgio R; Ferreira, Francis Barbosa; Rodrigues, Renata Santos; Achê, David Collares; Richardson, Michael; Borges, Márcia Helena; Rodrigues, Veridiana M

2011-10-10

258

Expression of mRNAs coding for VAP1/crotastatin-like metalloproteases in the venom glands of three South American pit vipers assessed by quantitative real-time PCR.  

PubMed

Snake venom metalloproteases encompass a large family of toxins, with approximately 200 members already catalogued, which exhibit a diversity of structures and biological functions. From this relatively large number, only a dozen examples of apoptosis-inducing metalloproteases, like VAP1 and 2 from the venom of Crotalus atrox, are known. Since most VAP1-like toxins ever characterized were purified from the venom of Viperidae species inhabiting diverse places on earth, we investigate the expression of VAP-like metalloproteases in the venom gland of three representative pit vipers of the Brazilian territory. By molecular cloning and quantitative real-time polymerase chain reaction, using as calibrator gene the Crotalus durissus terrificus homolog of VAP1, named crotastatin, it is reported here that VAP1/crotastatin-like homologues in the venom gland of Bothrops atrox, C. d. cascavella and Lachesis m. rhombeata are expressed at different levels. Hence, batroxstatins, the crotastatin-like precursors from B. atrox, are expressed 87 times more than crotastatin-1, from C. d. cascavella, and 7.5-fold that lachestatins, from L. m. rhombeata. Moreover, in silico structural analysis of amino acid sequences indicates that batroxstatin-2, crotastatins and lachestatin-1 and -2 which share the archetypal motifs and metal- binding sites of VAP1, are subgrouped in a branch that comprises some apoptosis-inducing toxins. PMID:18926840

Tavares, N A C; Correia, J M; Guarnieri, M C; Lima-Filho, J L; Prieto-da-Silva, A R B; Rádis-Baptista, G

2008-09-27

259

1H-NMR assignments and secondary structure of dendroaspin, an RGD-containing glycoprotein IIb-IIIa (alpha IIb-beta 3) antagonist with a neurotoxin fold.  

PubMed

Dendroaspin, also referred to as mambin, was originally isolated from the venom of the Elapidae snake Dendroaspis jamesoni kaimose. It shares a high level of sequence similarity with the short-chain neurotoxins found in other Elapidae but displays approximately 1000-fold lower neurotoxin activity than the closely related protein erabutoxin b. However, unlike neurotoxins, it contains an RGD (Arg-Gly-Asp) motif and functions as an antagonist of platelet aggregation and cell-cell adhesion of comparable potency to the disintegrins from the venoms of Viperidae. We have determined the secondary structure of dendroaspin using 1H-NMR spectroscopy. Its structure resembles that of the short-chain neurotoxins, with three loops extending from a disulphide-bridged core; however, the strands of the triple-stranded beta-sheet are shorter and the loop containing the RGD sequence is moved away from this sheet. The structure bears little resemblance to that of the disintegrins, except in the RGD-containing loop, suggesting that this loop may be of prime importance in its inhibitory function. Comparison of this preliminary structure with that of the neurotoxins and disintegrins furthers our understanding of the mechanism of integrin antagonists and shows how the neurotoxin fold can be manipulated to give a variety of inhibitors. PMID:7813476

Jaseja, M; Lu, X; Williams, J A; Sutcliffe, M J; Kakkar, V V; Parslow, R A; Hyde, E I

1994-12-15

260

Anti-Echis carinatus venom antibodies from chicken egg yolk: isolation, purification and neutralization efficacy.  

PubMed

High titer antibodies (IgY) were raised in egg yolk of white leghorn chicken (Gallus gallus domesticus) by immunizing with the venom of Echis carinatus (Saw scaled viper or carpet viper), an Indian venomous snake belonging to the family Viperidae. The anti-snake venom antibodies (antivenom) were isolated from egg yolk by the water dilution method, enriched by 19% sodium sulfate precipitation and purified by immunoaffinity chromatography. A single, electrophoretically pure IgY band of 180-200 kDa was obtained on SDS-PAGE. Immunoblot analysis revealed not only the specific binding of the antivenom but also dose-dependent blocking of antivenom by venom proteins. In neutralization studies, a preincubated mixture of both affinity-purified (50 mg/kg body weight) as well as partially purified (210 mg/kg body weight) anti-E. carinatus IgY with 2 LD(50) dose of E. carinatus venom (2 x 6.65 mg/kg body weight) gave 100% protection in mice when administered subcutaneously. PMID:17681579

Paul, K; Manjula, J; Deepa, E P; Selvanayagam, Z E; Ganesh, K A; Subba Rao, P V

2007-06-26

261

Structural and dynamical properties of KTS-disintegrins: A comparison between Obtustatin and Lebestatin.  

PubMed

Obtustatin and Lebestatin are lysine-threonine-serine (KTS)-disintegrins, which are a family of low molecular weight polypeptides present in many viperidae venoms and are potent and specific inhibitors of collagen-binding integrins. The integrin binding loop, harboring the (21) KTS(23) motif, and the C-terminal tail are known to be responsible for the selective binding to the ?1?1 integrin. Despite a very high sequence homology (only two mutations are present in Lebestatin relative to Obtustatin, namely R24L and S38L), Lebestatin exhibits a higher inhibitory effect than Obtustatin on cell adhesion and cell migration to collagens I and IV. Here we show, by means of molecular dynamics simulations of the two polypeptides in aqueous solution, that Lebestatin possesses a higher flexibility of the C-terminal tail and a greater solvent accessibility of the integrin binding loop than Obtustatin. It may be hypothesized that these properties may contribute to the higher binding-affinity of Lebestatin to its biological partner. © 2012 Wiley Periodicals, Inc. PMID:23097229

Daidone, Isabella; Aschi, Massimiliano; Patamia, Maria; Bozzi, Argante; Petruzzelli, Raffaele

2013-01-01

262

Volkmann's contracture of the forearm owing to an insect bite: a case report and review of the literature.  

PubMed

Compartment syndrome affecting the upper limb is reported rarely in the literature and is usually limited to single case reports. Upper limb compartment syndrome secondary to envenomation is rare, especially in the UK. Worldwide, it has been reported resulting from snake and insect bites, mostly from snakes from the Viperidae family, and from insects such as bees and wasps. Reports from the UK are limited to one case of an adder bite. We present a case of a previously fit and well adult who developed an ischaemic contracture of the forearm after an insect bite. Surgical exploration revealed segmental necrosis and contracture of the superficial and deep flexors of the fingers, requiring fasciotomy and tendon-lengthening procedures. This is the first report of a compartment syndrome, or a late ischaemic contracture from an insect bite in the UK. Owing to the rarity of compartment syndrome of the upper limb secondary to envenomation, a delay in diagnosis and treatment can lead to irreversible changes in the muscular compartments of the forearm. PMID:23484979

Hardwicke, J; Srivastava, S

2013-03-01

263

Snake venomics and toxicological profiling of the arboreal pitviper Bothriechis supraciliaris from Costa Rica.  

PubMed

The genus Bothriechis comprises a lineage of nine species of Neotropical pitvipers distributed mainly in highlands across Middle America, all adapted to arboreal habitats. Bothriechis supraciliaris is a relatively recently described species that inhabits the Pacific southwest of Costa Rica, whose venom had never been studied. A proteomic and toxicological profiling of its venom is here reported. Proteins or peptides that belong to eleven families were found, with a predominance of bradykinin-potentiating peptides (21.9%), followed by serine proteinases (15.2%) and phospholipases A(2) (13.4%). A group of short polyglycine peptides, resembling the poly-His/poly-Gly metalloproteinase inhibitors described in Atheris and Echis snake venoms, was observed for the first time in a Bothriechis venom. Comparison of the venom proteome of B. supraciliaris with those of Bothriechis schlegelii, Bothriechis lateralis, and Bothriechis nigroviridis, confirms the highly diverse toxicological strategies evolved by these arboreal snakes in each case, as possible alternative solutions to the same trophic purpose. Toxicological profiling of B. supraciliaris venom revealed a potent hemorrhagic action, moderate myotoxicity, and very weak procoagulant activity. Importantly from the medical perspective, the lethal activity of its venom (mouse intraperitoneal LD(50): 7.1 ?g/g) was efficiently neutralized by a polyvalent (Viperidae) antivenom of therapeutic use in Central America. PMID:22333435

Lomonte, Bruno; Tsai, Wan-Chih; Bonilla, Fabián; Solórzano, Alejandro; Solano, Gabriela; Angulo, Yamileth; Gutiérrez, José María; Calvete, Juan J

2012-02-06

264

The complete mitochondrial genome of a gecko and the phylogeneticposition of the Middle Eastern teratoscincus keyserlingii  

SciTech Connect

Sqamate reptiles are traditionally divided into six groups: Iguania, Anguimorpha, Scincomorpha, Gekkota (these four are lizards), Serpentes (snakes), and Amphisbaenia (the so-called worm lizards). Currently there are complete mitochondrial genomes from two representatives of the Iguania (Janke et al., 2001; Kumazawa, 2004), three from the Anguimorpha (Kumazawa, 2004; Kumazawa and Endo, 2004), two from the Scincomorpha (Kumazawa and Nishida, 1999; Kumazawa, 2004), two from Serpentes (Kumazawa et al., 1998; Kumazawa, 2004) and 12 from Amphisbaenia (Macey et al., 2004). The only traditional group of Squamata from which a complete mitochondrial genome has not been sequenced is the Gekkota. Here we report the complete mitochondrial genome of Teratoscincus keyserlingii, a Middle Eastern representative of the Gekkota. The gekkonid lizard genus Teratoscincus is distributed throughout the deserts of central and southwest Asia as shown in figure 1, with five species currently recognized (Macey et al. 1997a, 1999b). Included in this figure are the positions of mountain ranges discussed in the text; see also figure 1 in Macey et al. (1999b). Two species, T. bedriagai and T. microlepis, are restricted to Southwest Asia south of the Kopet Dagh and Hindu Kush in Iran, Afghanistan, and Pakistan (Anderson, 1999). Two species are found in the deserts of western China and Mongolia, with T. przewalskii occurring in the Taklimakan and lowland Gobi deserts, and T. roborowskii restricted to the Turpan Depression. The fifth species, T. scincus, is sometimes considered to be restricted to the Caspian Basin in Kazakhstan, Kyrgyzistan, Tadjikistan, Turkmenistan and Uzbekistan. Alternatively, Teratoscincus populations in Southwest Asia, primarily on the Iranian Plateau, situated directly north of the Arabian Plate, are sometimes considered to be a subspecies of T. scincus or, otherwise, to constitute a sixth species, T. keyserlingii. Macey et al. (1999b) assessed the phylogenetic relationships of four Teratoscincus species with mitochondrial DNA sequences from a {approx}1800 base-pair segment spanning from nad1 to cox1. Phylogenetic analysis places T. microlepis in a basal position to a clade containing T. scincus, T. przewalskii and T. roborowskii, with the later two as sister taxa. This phylogenetic arrangement suggests that tectonic plate movements in Southwest Asia and western China due to the Indian and Arabian collisions caused speciation among Teratoscincus species. No molecular phylogenetic study has included the putative species T. keyserlingii.

Macey, J. Robert; Fong, Jonathan J.; Kuehl, Jennifer V.; Shafiei,Soheila; Ananjeva, Natalia B.; Papenfuss, Theodore J.; Boore, Jeffrey L.

2005-04-22

265

Commiphora molmol in human welfare (review article).  

PubMed

The origins of myrrh and frankincense are traced to the Arabian Peninsula. According to Herodotus (5th century BC): "Arabia is the only country which produces frankincense, myrrh, cassia and cinnamon ... the trees bearing the frankincense are guarded by winged serpents of small size and various colors." Diodorus Siculus writes, in the second half of the first century BC, that "all of Arabia exudes a most delicate fragrance; even the seamen passing by Arabia can smell the strong fragrance that gives health and vigor." He also mentioned gold mines so pure that no smelting was necessary. The Magi, carrying myrrh, frankincense, and gold, came from the East: Arabia. The frankincense trade route, with transport by donkeys and later by camel caravans, reached Jerusalem and Egypt from the Dhofar region of what is today Oman, through Yemen, turning north to follow the Red Sea coast. It is likely that the same or similar species of the resin-bearing plants grew across the Red Sea in the area that is now Somalia and Ethiopia, while the collection of the gum resins was initiated in Arabia. Myrrh contributed much in the human welfare. This review selected some but not all of the value application of myrrh (Commiphora molmol). PMID:17985580

Al-Mathal, Ebtsam M

2007-08-01

266

Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome.  

PubMed

We provide phylogenetic analyses for primary Reptilia lineages including, for the first time, Sphenodon punctatus (tuatara) using data from whole mitochondrial genomes. Our analyses firmly support a sister relationship between Sphenodon and Squamata, which includes lizards and snakes. Using Sphenodon as an outgroup for select squamates, we found evidence indicating a sister relationship, among our study taxa, between Serpentes (represented by Dinodon) and Varanidae. Our analyses support monophyly of Archosauria, and a sister relationship between turtles and archosaurs. This latter relationship is congruent with a growing set of morphological and molecular analyses placing turtles within crown Diapsida and recognizing them as secondarily anapsid (lacking a skull fenestration). Inclusion of Sphenodon, as the only surviving member of Sphenodontia (with fossils from the mid-Triassic), helps to fill a sampling gap within previous analyses of reptilian phylogeny. We also report a unique configuration for the mitochondrial genome of Sphenodon, including two tRNA(Lys) copies and an absence of ND5, tRNA(His), and tRNA(Thr) genes. PMID:13678684

Rest, Joshua S; Ast, Jennifer C; Austin, Christopher C; Waddell, Peter J; Tibbetts, Elizabeth A; Hay, Jennifer M; Mindell, David P

2003-11-01

267

Genome-Wide Transcription Analysis of Clinal Genetic Variation in Drosophila  

PubMed Central

Clinal variation in quantitative traits is widespread, but its genetic basis awaits identification. Drosophila melanogaster shows adaptive, clinal variation in traits such as body size along latitudinal gradients on multiple continents. To investigate genome wide transcription differentiation between North and South that might contribute to the clinal phenotypic variation, we compared RNA expression patterns during development of D. melanogaster from tropical northern and temperate southern populations using whole genome tiling arrays. We found that genes that were differentially expressed between the cline ends were generally associated with metabolism and growth, and experimental alteration of expression of a sample of them generally resulted in altered body size in the predicted direction, sometimes significantly so. We further identified the serpent (srp) transcription factor binding sites to be enriched near genes up-regulated in expression in the south. Analysis of clinal populations revealed a significant cline in the expression level of srp. Experimental over-expression of srp increased body size, as predicted from its clinal expression pattern, suggesting that it may be involved in regulating adaptive clinal variation in Drosophila. This study identified a handful of genes that contributed to clinal phenotypic variation through altered gene expression level, yet misexpression of individual gene led to modest body size change.

Chen, Ying; Lee, Siu F.; Blanc, Eric; Reuter, Caroline; Wertheim, Bregje; Martinez-Diaz, Pedro; Hoffmann, Ary A.; Partridge, Linda

2012-01-01

268

Adaptive Evolution of the Venom-Targeted vWF Protein in Opossums that Eat Pitvipers  

PubMed Central

The rapid evolution of venom toxin genes is often explained as the result of a biochemical arms race between venomous animals and their prey. However, it is not clear that an arms race analogy is appropriate in this context because there is no published evidence for rapid evolution in genes that might confer toxin resistance among routinely envenomed species. Here we report such evidence from an unusual predator-prey relationship between opossums (Marsupialia: Didelphidae) and pitvipers (Serpentes: Crotalinae). In particular, we found high ratios of replacement to silent substitutions in the gene encoding von Willebrand Factor (vWF), a venom-targeted hemostatic blood protein, in a clade of opossums known to eat pitvipers and to be resistant to their hemorrhagic venom. Observed amino-acid substitutions in venom-resistant opossums include changes in net charge and hydrophobicity that are hypothesized to weaken the bond between vWF and one of its toxic snake-venom ligands, the C-type lectin-like protein botrocetin. Our results provide the first example of rapid adaptive evolution in any venom-targeted molecule, and they support the notion that an evolutionary arms race might be driving the rapid evolution of snake venoms. However, in the arms race implied by our results, venomous snakes are prey, and their venom has a correspondingly defensive function in addition to its usual trophic role.

Jansa, Sharon A.; Voss, Robert S.

2011-01-01

269

The story of the condom  

PubMed Central

Condoms have been a subject of curiosity throughout history. The idea of safer sex has been explored in ancient and modern history, and has been used to prevent venereal diseases. We conducted a historical and medical review of condoms using primary and secondary sources as well as using the RSM library and the internet. These resources show that the first use of a condom was that of King Minos of Crete. Pasiphae, his wife, employed a goat's bladder in the vagina so that King Minos would not be able to harm her as his semen was said to contain “scorpions and serpents” that killed his mistresses. To Egyptians, condom-like glans caps were dyed in different colours to distinguish between different classes of people and to protect themselves against bilharzia. The Ancient Romans used the bladders of animals to protect the woman; they were worn not to prevent pregnancy but to prevent contraction of venereal diseases. Charles Goodyear, the inventor, utilized vulcanization, the process of transforming rubber into malleable structures, to produce latex condoms. The greater use of condoms all over the world in the 20th and 21st centuries has been related to HIV. This account of the use of condoms demonstrates how a primitive idea turned into an object that is used globally with a forecast estimated at 18 billion condoms to be used in 2015 alone.

Khan, Fahd; Mukhtar, Saheel; Dickinson, Ian K.; Sriprasad, Seshadri

2013-01-01

270

Herpetofauna of an Atlantic rainforest area (Morro São João) in Rio de Janeiro State, Brazil.  

PubMed

We studied the herpetofaunal community from the Atlantic forest of Morro São João, in Rio de Janeiro State, Brazil, and present data on species composition, richness, relative abundance and densities. We combined three sampling methods: plot sampling, visual encounter surveys and pit-fall traps. We recorded sixteen species of amphibians and nine of reptiles. The estimated densities (based on results of plot sampling) were 4.5 ind/100 m2 for amphibians and 0.8 ind/100 m2 for lizards, and the overall density (amphibians and lizards) was 5.3 ind/100 m2. For amphibians, Eleutherodactylus and Scinax were the most speciose genera with three species each, and Eleutherodactylus binotatus was the most abundant species (mean density of 3.0 frogs/100 m2). The reptile community of Morro São João was dominated by species of the families Gekkonidae and Gymnophtalmidae (Lacertilia) and Colubridae (Serpentes). The gymnophtalmid lizard Leposoma scincoides was the most abundant reptile species (mean density of 0.3 ind/100 m2). We compare densities obtained in our study data with those of other studied rainforest sites in various tropical regions of the world. PMID:18506255

Almeida-Gomes, Mauricio; Vrcibradic, Davor; Siqueira, Carla C; Kiefer, Mara C; Klaion, Thaís; Almeida-Santos, Patrícia; Nascimento, Denise; Ariani, Cristina V; Borges-Junior, Vitor N T; Freitas-Filho, Ricardo F; van Sluys, Monique; Rocha, Carlos F D

2008-06-01

271

Emergence of undulatory magnetic flux tubes by small scale reconnections  

NASA Astrophysics Data System (ADS)

With Flare Genesis Experiment (FGE), a balloon borne observatory launched in Antarctica on January 2000, series of high spatial resolution vector magnetograms, Dopplergrams, and H? filtergrams have been obtained in an emerging active region (AR 8844). Previous analyses of this data revealed the occurence of many short-lived and small-scale H? brightenings called 'Ellerman bombs' (EBs) within the AR. We performed an extrapolation of the field above the photosphere using the linear force-free field approximation. The analysis of the magnetic topology reveals a close connexion between the loci of EBs and the existence of ``Bald patches'' regions (BPs are regions where the vector magnetic field is tangential to the photosphere). Among 47 identified EBs, we found that 23 are co-spatial with a BP, while 19 are located at the footpoint of very flat separatrix field lines passing throught a distant BP. We reveal for the first time that some of these EBs/BPs are magneticaly connected by low-lying lines, presenting a 'sea-serpent' shape. This results leads us to conjecture that arch filament systems and active regions coronal loops do not result from the smooth emergence of large scale ? loops, but rather from the rise of flat undulatory flux tubes which get released from their photospheric anchorage by reconnection at BPs, whose observational signature is Ellerman bombs.

Pariat, E.; Aulanier, G.; Schmieder, B.; Georgoulis, M. K.; Rust, D. M.; Bernasconi, P. N.

272

[Assessment and correlation analysis of heavy metals pollution in soil of Dajinshan Island].  

PubMed

The Dajinshan Island is the highest altitude point in the nature land of Shanghai. In order to find out the status of soil heavy metals pollution of the Dajinshan Island and its correlation, this paper used the methods of grid and serpents sampling to collect samples, and applied the single factor pollution index method and potential ecological harm index method to assess the pollutions status. The results showed that the main contributor of soil heavy metal pollution in Dajinshan Island was Cd, with an over-standard rate of 85.4%, followed by Pb, with an over-standard rate of 26.8%, whereas Zn and Cu were not excessive. In addition, there was significant positive correlation between Pb-Cu, Pb-Zn and Cu-Zn at the level of P = 0.05, suggesting that they had high homology and were easily influenced by the soil forming materials. This was an indirect evidence that the Dajinshan Island was well protected and not much affected by human activities. PMID:23745415

Cheng, Fang; Cheng, Jin-Ping; Sang, Heng-Chun; Yu, Jin-Lian; Xi, Lei; Pi, Shuai-Shuai

2013-03-01

273

Origins of the ancient constellations: II. The Mediterranean traditions  

NASA Astrophysics Data System (ADS)

The classical map of the sky, with the 48 Greek constellations, was derived from at least two different pre-Greek traditions. One tradition comprised the 12 signs of the zodiac, with several associated animal constellations, all of which developed over ~3200-500 BC in Mesopotamia in a religious or ritual tradition. These were taken over by the Greeks around 500 BC. However the other Babylonian constellations, their farming-calendar tradition, were not adopted. The other tradition was not Mesopotamian; it comprised large constellations which appear to date from ~2800 BC, probably from the Mediterranean region, devised for the navigators of ships. They include huge bears and serpents which marked the celestial pole and equator at that time, and probably the four anonymous giants which we know as Hercules, Ophiuchus, Bootes, and Auriga, as well as some of the large southern 'marine' constellations. The origins of some other constellations, including the Perseus tableau and various animals, are unknown; they may have been new creations of the Greeks. The Greeks assembled the classical sky-map from these different sources between 540-370 BC, but many of the familiar legends were only applied to the constellations later.

Rogers, J. H.

1998-04-01

274

Maine's MOLLOCKET and METALLAK: Adherents of God's Secret Spirit Signal, SSS, Applied Physicists of the EMF/Manitou, Doctors, Reincarnationists, "Potlachers," Confidants of the Powerful, and, they Did Own the Land.  

NASA Astrophysics Data System (ADS)

Northeastern ``Indians,'' reputed to ``make the weather,'' actually, from youth, observed earth phenomena, including SSS. These are subtle and barely detectable visual artifacts of the electromagnetic field, special information that led/leads to their spiritual belief in reincarnation, which came from the EMF/SSS communication, backward and forward, (up to) seven generations. It commands communal, democratic, ``potlatch'' redistribution of accumulated wealth, Mother Earth's bounty, from their land, gifted by ``The Great Spirit,'' Manitou, Peru's Ñari Huallac, ``Serpent God.'' Genetics established the non-Asian origins of 1/3 of North American Indians. Linguistics indicates a major impact westwards to us. MILLInocket is ``Adherent of God (Spirit-signal) monk Cathar.'' Katahdin, with a shared root, has Manitou. After 1820, Gov. E. Lincoln and at least one US senator went westward to MetALLAk; his biography is by a Rumford, ME Knight of Pythias. Why? MOLLOCKET frequently asserted ownership of western Maine. ``Great Council Fires,'' religious ``Law Things,'' were at Merrymeeting Bay in pre-Colonial times. ``Medicine men/priests'' often participated as their applied scientist-statesmen. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NES07.C2.1

Andrade, Jennifer; Ferreira, Nadja; Mc Leod, Roger D.

2007-04-01

275

Lethal envenomation: medicolegal aspects of snakebites and religious snake handlers in Kentucky: a report of three cases with comment on medical, legal, and public policy ramifications.  

PubMed

Ritualistic serpent qua snake handling, which rests upon inveterate religious conviction arising out of literal interpretation of selected passages of the New Testament, is a rare ceremony practiced by a distinct minority of Christians predominantly in rural Appalachian regions of the United States commonly referred to as the Bible belt. The fervent, frenzied pursuit by anointed "sign-followers" of intimate contact with a variety of poisonous snakes, however, puts the handler together with sect members or bystanders at risk for lethal envenomation, particularly when prompt medical attention is held by the congregation of faith to contravene God's will. The authors report three separate cases of death due to envenomation by snakebite during a church service and the handler's faith-based refusal to seek treatment. Postmortem examination of each yielded similar physical findings attributable to various toxic sequelae of the complex venoms. A review of the injurious constituents of these chemical toxins also includes a discussion of complex pathophysiological mechanisms causing death. In addition, the authors review the history of representative legislative and judicial responses to the sensationally mortal phenomenon, all of which ineluctably grapple with fundamental Constitutional issues devolving from such controversial religious practices. We underscore the view that a thoroughly documented medicolegal investigation and autopsy are indispensable to both inform matters of public health and thereby contribute to the formulation of sound public policy. PMID:16302722

Hunsaker, Donna M; Hunsaker, John C; Clayton, Tara; Spiller, Henry A

2005-11-01

276

Evidence for serpentinite fluid in convergent margin systems: The example of El Salvador (Central America) arc lavas  

NASA Astrophysics Data System (ADS)

A comprehensive geochemical study, including B, Pb, Sr, and Nd isotopes, has been carried out on El Salvador subduction-related lavas. The rocks have arc-type incompatible element distributions with high LILE/HFSE ratios, nearly constant 143Nd/144Nd (?0.5130), and small differences in 207Pb/204Pb (15.53-15.57), whereas 87Sr/86Sr ranges from 0.7035 to 0.7039. Boron isotopic composition varies widely, between -2.7‰ and +6.3‰. The boron isotope signature points to involvement of fluid inputs from (1) a high-?11B serpentinite fluid from serpentized mantle wedge dragged beneath the volcanic arc or from the subducting lithosphere and (2) a low-?11B fluid from the progressive dehydration of subducted altered basaltic crust and/or sediments. The observed sample variability is explained with a model in which different proportions of serpentinite-derived (10-50%) and slab-derived fluids are added to an enriched-DMM source, triggering its partial melting. We suggest a model in which tectonic erosion, i.e., dragging down of slivers of serpentinized upper plate mantle, was responsible for the occurrence of serpentinite reservoir, 11B-enriched in the forearc by shallow fluids.

Tonarini, Sonia; Agostini, Samuele; Doglioni, Carlo; Innocenti, Fabrizio; Manetti, Piero

2007-09-01

277

Gene expression analysis in post-embryonic pericardial cells of Drosophila.  

PubMed

Increasing evidence suggests conservation of cardiovascular molecules between vertebrates and invertebrates. Vertebrate Rudhira, an evolutionary conserved WD40 protein is expressed during primitive erythropoiesis, neoangiogenesis and tumors. We report here the expression profile of the Drosophila ortholog of Rudhira (DRudh) in the fly life cycle. DRudh is expressed specifically in all post-embryonic pericardial cells (PCs) and garland cells (GCs). This is the first report of a cytoplasmic marker highly specific to post-embryonic PCs. Embryonic PCs belong to three distinct genetic classes based on Odd-skipped (Odd), Even-skipped (Eve) and Tinman (Tin) expression. To identify which among these three classes of PCs expresses DRudh in post-embryonic stages, we analyzed expression of embryonic PC markers in the post-embryonic stages. Unlike in the embryo all larval PCs show an identical gene expression profile. While Odd and Eve expression is mutually exclusive in the embryonic PCs, these two markers are co-expressed in larval PCs but show a distinct subcellular localization. Tin is not expressed in any post-embryonic PC. Additionally larval PCs also express the GATA factor, Serpent (Srp) and the extracellular matrix protein, Pericardin (Prc). While PC number is known to decrease post-embryogenesis, which of the Odd or Eve lineage embryonic PCs persists is not known. Co-expression of the two distinct lineage markers only in post-embryonic stages indicates a complex temporal regulation of gene expression in PCs. PMID:18060846

Das, Debjani; Ashoka, D; Aradhya, Rajaguru; Inamdar, Maneesha

2007-11-01

278

The Friend of GATA proteins U-shaped, FOG-1, and FOG-2 function as negative regulators of blood, heart, and eye development in Drosophila  

PubMed Central

Friend of GATA (FOG) proteins regulate GATA factor-activated gene transcription. During vertebrate hematopoiesis, FOG and GATA proteins cooperate to promote erythrocyte and megakaryocyte differentiation. The Drosophila FOG homologue U-shaped (Ush) is expressed similarly in the blood cell anlage during embryogenesis. During hematopoiesis, the acute myeloid leukemia 1 homologue Lozenge and Glial cells missing are required for the production of crystal cells and plasmatocytes, respectively. However, additional factors have been predicted to control crystal cell proliferation. In this report, we show that Ush is expressed in hemocyte precursors and plasmatocytes throughout embryogenesis and larval development, and the GATA factor Serpent is essential for Ush embryonic expression. Furthermore, loss of ush function results in an overproduction of crystal cells, whereas forced expression of Ush reduces this cell population. Murine FOG-1 and FOG-2 also can repress crystal cell production, but a mutant version of FOG-2 lacking a conserved motif that binds the corepressor C-terminal binding protein fails to affect the cell lineage. The GATA factor Pannier (Pnr) is required for eye and heart development in Drosophila. When Ush, FOG-1, FOG-2, or mutant FOG-2 is coexpressed with Pnr during these developmental processes, severe eye and heart phenotypes result, consistent with a conserved negative regulation of Pnr function. These results indicate that the fly and mouse FOG proteins function similarly in three distinct cellular contexts in Drosophila, but may use different mechanisms to regulate genetic events in blood vs. cardial or eye cell lineages.

Fossett, Nancy; Tevosian, Sergei G.; Gajewski, Kathleen; Zhang, Qian; Orkin, Stuart H.; Schulz, Robert A.

2001-01-01

279

Snakes antibodies.  

PubMed

Immunoglobulins are basic molecules of the immune system of vertebrates. In previous studies we described the immunoglobulins found in two squamata reptiles, Anolis carolinensis and Eublepharis macularius. Snakes are squamata reptiles too but they have undergone an extreme evolutionary process. We therefore wanted to know how these changes affected their immunoglobulin coding genes. To perform this analysis we studied five snake transcriptomes and two genome draft sequences. Sequences coding for immunoglobulin M (IgM), immunoglobulin D (IgD) and two classes of immunoglobulin Y (IgY - named IgYa and IgYb-) were found in all of them. Moreover, the Thamnophis elegans transcriptome and Python molurus genome draft sequences showed a third class of IgY, the IgYc, whose constant region only presents three domains and lacks the CH2. All data suggest that the IgYb is the evolutionary origin of this IgYc. An exhaustive search of the light chains were carried out, being lambda the only light chain found in snakes. The results provide a clear picture of the immunoglobulins present in the suborder Serpentes. PMID:22426516

Gambón-Deza, Francisco; Sánchez-Espinel, Christian; Mirete-Bachiller, Serafín; Magadán-Mompó, Susana

2012-03-14

280

Large Cretaceous sphenodontian from Patagonia provides insight into lepidosaur evolution in Gondwana.  

PubMed

Sphenodontian reptiles successfully radiated during Triassic and Jurassic times, but were driven almost to extinction during the Cretaceous period. The sparse Early Cretaceous record of sphenodontians has been interpreted as reflecting the decline of the group in favour of lizards, their suspected ecological successors. However, recent discoveries in Late Cretaceous beds in Patagonia partially modify this interpretation. Numerous skeletons of a new sphenodontian, Priosphenodon avelasi gen. et sp. nov., were collected from a single locality in the Cenomanian-Turonian Candeleros Formation, where it is more abundant than any other tetrapod group recorded in the quarry (for example, Crocodyliformes, Serpentes, Dinosauria and Mammalia). Adult specimens of Priosphenodon reached one metre in length, larger than any previously known terrestrial sphenodontian. Here we propose, using available evidence, that sphenodontians were not a minor component of the Cretaceous terrestrial ecosystems of South America, and that their ecological replacement by squamates was delayed until the early Tertiary. The new discovery helps to bridge the considerable gap in the fossil record (around 120 million years) that separates the Early Cretaceous sphenodontians from their living relatives (Sphenodon). PMID:14534584

Apesteguía, Sebastián; Novas, Fernando E

2003-10-01

281

Salmonella pathogenesis reveals that BMP signaling regulates blood cell homeostasis and immune responses in Drosophila  

PubMed Central

Intercellular signaling by bone morphogenetic proteins (BMPs) regulates developmental decisions in virtually all animals. Here, we report that Decapentaplegic (Dpp; a Drosophila BMP family member) plays a role in blood cell homeostasis and immune responses by regulating a transcription factor cascade. The cascade begins with Dpp repression of Zfh1, continues with Zfh1 activation of Serpent (Srp; a GATA factor), and terminates with Srp activation of U-shaped (Ush) in hematopoietic cells. Hyperactivation of Zfh1, Srp, and Ush in dpp mutants leads to hyperplasia of plasmatocytes. Salmonella challenge revealed that in dpp mutants the misregulation of this cascade also prevents the generation of lamellocytes. These findings support the hypothesis that Ush participates in a switch between plasmatocyte and lamellocyte fate in a common precursor and further suggests a mechanism for how all blood cell types can arise from a single progenitor. These results also demonstrate that combining Drosophila and Salmonella genetics can provide novel opportunities for advancing our knowledge of hematopoiesis and innate immunity.

Frandsen, Joel L.; Gunn, Bronwyn; Muratoglu, Selen; Fossett, Nancy; Newfeld, Stuart J.

2008-01-01

282

Art exhibit focuses on African astronomy  

NASA Astrophysics Data System (ADS)

Connections between Africans and astronomy are the focus of a new exhibition in the National Museum of African Art in Washington, D. C. “African Cosmos: Stellar Arts,” which includes artwork, cultural items, and scientific displays from ancient to contemporary times, is the first major exhibit “that brings together arts and science focused on Africa's contribution to keen observations of the heavens over time,” curator Christine Mullen Kreamer said at a 20 June news briefing. Among the exhibit's nearly 100 objects are an ancient Egyptian mummy board that includes a representation of the sky goddess Nut, sculptures by the Dogon people of Mali depicting figures in relation to the cosmos, a video that uses data from two square degrees of the Hubble Space Telescope Cosmic Evolution Survey, and a nearly floor-to-ceiling “Rainbow Serpent” constructed of plastic containers by Benin artist Hazoume. An untitled acrylic painting (Figure 1) by South African Gavin Jantjes evokes a myth of the Khoi San people of southern Africa, as it portrays a girl throwing evening fire embers into the night sky, where they remained as the Milky Way.

Showstack, Randy

2012-07-01

283

Micrurus snake venoms activate human complement system and generate anaphylatoxins  

PubMed Central

Background The genus Micrurus, coral snakes (Serpentes, Elapidae), comprises more than 120 species and subspecies distributed from the south United States to the south of South America. Micrurus snake bites can cause death by muscle paralysis and further respiratory arrest within a few hours after envenomation. Clinical observations show mainly neurotoxic symptoms, although other biological activities have also been experimentally observed, including cardiotoxicity, hemolysis, edema and myotoxicity. Results In the present study we have investigated the action of venoms from seven species of snakes from the genus Micrurus on the complement system in in vitro studies. Several of the Micrurus species could consume the classical and/or the lectin pathways, but not the alternative pathway, and C3a, C4a and C5a were generated in sera treated with the venoms as result of this complement activation. Micrurus venoms were also able to directly cleave the ? chain of the component C3, but not of the C4, which was inhibited by 1,10 Phenanthroline, suggesting the presence of a C3? chain specific metalloprotease in Micrurus spp venoms. Furthermore, complement activation was in part associated with the cleavage of C1-Inhibitor by protease(s) present in the venoms, which disrupts complement activation control. Conclusion Micrurus venoms can activate the complement system, generating a significant amount of anaphylatoxins, which may assist due to their vasodilatory effects, to enhance the spreading of other venom components during the envenomation process.

2012-01-01

284

Nova Scotia: ``Feu Follet" At Cheticamp, and Also the Phenomena At L'Sitkuk of the Mi'Kmaw, May Be Electromagnetic In Nature.  

NASA Astrophysics Data System (ADS)

There is a strong tradition that ``feu follet" exists at the cemetery associated with the Acadian French at Cheticamp. It is described as a blue light, and may actually be the equivalent of an ascending, positively charged stream of ions in the atmosphere, just like the blue-light column that is often a precursor of a storm's lightning-strike. Similar phenomena are at America's Stonehenge, at a stone serpent effigy site in Ohio, and just north of the Lakes Memphremagog and Magog of Vermont and Canada. At the Bear River L'sitkuk Reservation area, which seems to us to have been a most unsuitable site, was deliberately chosen by the Mi'kmaw for their living area. Was this because certain properties of the electromagnetic field (EMF) are evident to them there, which also seem to be reflected in their legends? We hope to establish that these disparate cultures and their separate worldviews can be confirmed by the presence of particular EMF signatures. *This paper does not represent the views of the United States Environmental Protection Agency.

Ochs, Michael Ann; McLeod, Roger D.

2001-11-01

285

Crotalid snake venom subproteomes unraveled by the antiophidic protein DM43.  

PubMed

Snake venoms are mixtures of proteins and peptides with different biological activities, many of which are very toxic. Several animals, including the opossum Didelphis aurita, are resistant to snake venoms due to the presence of neutralizing factors in their blood. An antihemorrhagic protein named DM43 was isolated from opossum serum. It inhibits snake venom metalloproteinases through noncovalent complex formation with these enzymes. In this study, we have used DM43 and proteomic techniques to explore snake venom subproteomes. Four crotalid venoms were chromatographed through an affinity column containing immobilized DM43. Bound fractions were analyzed by one- and two-dimensional gel electrophoresis, followed by identification by MALDI-TOF/TOF mass spectrometry. With this approach, we could easily visualize and compare the metalloproteinase compositions of Bothrops atrox, Bothrops jararaca, Bothrops insularis, and Crotalus atrox snake venoms. The important contribution of proteolytic processing to the complexity of this particular subproteome was demonstrated. Fractions not bound to DM43 column were similarly analyzed and were composed mainly of serine proteinases, C-type lectins, C-type lectin-like proteins, l-amino acid oxidases, nerve growth factor, cysteine-rich secretory protein, a few metalloproteinases (and their fragments), and some unidentified spots. Although very few toxin families were represented in the crotalid venoms analyzed, the number of protein spots detected was in the hundreds, indicating an important protein variability in these natural secretions. DM43 affinity chromatography and associated proteomic techniques proved to be useful tools to separate and identify proteins from snake venoms, contributing to a better comprehension of venom heterogeneity. PMID:19267469

Rocha, Surza L G; Neves-Ferreira, Ana G C; Trugilho, Monique R O; Chapeaurouge, Alex; León, Ileana R; Valente, Richard H; Domont, Gilberto B; Perales, Jonas

2009-05-01

286

Triacontyl p-coumarate: an inhibitor of snake venom metalloproteinases.  

PubMed

Snake venom metalloproteinases (SVMPs) participate in a number of important biological, physiological and pathophysiological processes and are primarily responsible for the local tissue damage characteristic of viperid snake envenomations. The use of medicinal plant extracts as antidotes against animal venoms is an old practice, especially against snake envenomations. Such plants are sources of many pharmacologically active compounds and have been shown to antagonize the effects of some venoms and toxins. The present study explores the activity of triacontyl p-coumarate (PCT), an active compound isolated from root bark of Bombacopsis glabra vegetal extract (Bg), against harmful effects of Bothropoides pauloensis snake venom and isolated toxins (SVMPs or phospholipase A(2)). Before inhibition assays, Bg or PCT was incubated with venom or toxins at ratios of 1:1 and 1:5 (w/w; venom or isolated toxins/PCT) for 30 min at 37°C. Treatment conditions were also assayed to simulate snakebite with PCT inoculated at either the same venom or toxin site. PCT neutralized fibrinogenolytic activity and plasmatic fibrinogen depletion induced by B. pauloensis venom or isolated toxin. PCT also efficiently inhibited the hemorrhagic (3MDH - minimum hemorrhagic dose injected i.d into mice) and myotoxic activities induced by Jararhagin, a metalloproteinase from B. jararaca at 1:5 ratio (toxin: inhibitor, w/w) when it was previously incubated with PCT and injected into mice or when PCT was administered after toxin injection. Docking simulations using data on a metalloproteinase (Neuwiedase) structure suggest that the binding between the protein and the inhibitor occurs mainly in the active site region causing blockade of the enzymatic reaction by displacement of catalytic water. Steric hindrance may also play a role in the mechanism since the PCT hydrophobic tail was found to interact with the loop associated with substrate anchorage. Thus, PCT may provide a alternative to complement ophidian envenomation treatments. PMID:23141056

Mendes, M M; Vieira, S A P B; Gomes, M S R; Paula, V F; Alcântara, T M; Homsi-Brandeburgo, M I; dos Santos, J I; Magro, A J; Fontes, M R M; Rodrigues, V M

2012-11-08

287

New insights into the structural elements involved in the skin haemorrhage induced by snake venom metalloproteinases.  

PubMed

Haemorrhage induced by snake venom metalloproteinases (SVMPs) is a complex phenomenon resulting in capillary disruption and extravasation. This study analysed structural elements important for the interaction of four Bothrops jararaca SVMPs of different domain organisation and glycosylation levels with plasma and extracellular matrix proteins: HF3 (P-III class) is highly glycosylated and ~80 times more haemorrhagic than bothropasin (P-III class), which has a minor carbohydrate moiety; BJ-PI (P-I class) is not haemorrhagic and the DC protein is composed of disintegrin-like/cysteine-rich domains of bothropasin. HF3, bothropasin and BJ-PI showed different degradation profiles of fibrinogen, fibronectin, vitronectin, von Willebrand factor, collagens IV and VI, laminin and Matrigel; however, only bothropasin degraded collagen I. In solid-phase binding assays HF3 and bothropasin interacted with fibrinogen, fibronectin, laminin, collagens I and VI; the DC protein bound only to collagens I and VI; however, no binding of BJ-PI to these proteins was detected. N-deglycosylation caused loss of structural stability of bothropasin and BJ-PI but HF3 remained intact, although its haemorrhagic and fibrinogenolytic activities were partially impaired. Nevertheless, N-deglycosylated HF3 bound with higher affinity to collagens I and VI, although its proteolytic activity upon these collagens was not enhanced. This study demonstrates that features of carbohydrate moieties of haemorrhagic SVMPs may play a role in their interaction with substrates of the extracellular matrix, and the ability of SVMPs to degrade proteins in vitro does not correlate to their ability to cause haemorrhage, suggesting that novel, systemic approaches are necessary for understanding the mechanism of haemorrhage generation by SVMPs. PMID:20664911

Oliveira, Ana K; Paes Leme, Adriana F; Asega, Amanda F; Camargo, Antonio C M; Fox, Jay W; Serrano, Solange M T

2010-07-20

288

Isolation and characterization of cotiaractivase, a novel low molecular weight prothrombin activator from the venom of Bothrops cotiara.  

PubMed

In this study, we isolated a novel prothrombin activator from the venom of Bothrops cotiara, a Brazilian lance-headed pit viper (Cotiara, Jararaca preta, Biocotiara), which we have designated "cotiaractivase" (prefix: cotiar- from B. cotiara; suffix: -activase, from prothrombin activating activity). Cotiaractivase was purified using a phenyl-Superose hydrophobic interaction column followed by a Mono-Q anion exchange column. It is a single-chain polypeptide with a molecular weight of 22,931 Da as measured by mass spectroscopy. Cotiaractivase generated active alpha-thrombin from purified human prothrombin in a Ca2+-dependent manner as assessed by S2238 chromogenic substrate assay and SDS-PAGE. Cotiaractivase cleaved prothrombin at positions Arg271-Thr272 and Arg320-Ile321, which are also cleaved by factor Xa. However, the rate of thrombin generation by cotiaractivase was approximately 60-fold less than factor Xa alone and 17 x 10(6)-fold less than the prothrombinase complex. The enzymatic activity of cotiaractivase was inhibited by the chelating agent EDTA, whereas the serine protease inhibitor PMSF had no effect on its activity, suggesting that it is a metalloproteinase. Interestingly, S2238 inhibited cotiaractivase activity non-competitively, suggesting that this toxin contains an exosite that allows it to bind prothrombin independently of its active site. Tandem mass spectrometry and N-terminal sequencing of purified cotiaractivase identified peptides that were identical to regions of the cysteine-rich and disintegrin-like domains of known snake venom metalloproteinases. Cotiaractivase is a unique low molecular weight snake venom prothrombin activator that likely belongs to the metalloproteinase family of proteins. PMID:16647309

Senis, Yotis A; Kim, Paul Y; Fuller, Gemma L J; García, Angel; Prabhakar, Sripadi; Wilkinson, Mark C; Brittan, Helen; Zitzmann, Nicole; Wait, Robin; Warrell, David A; Watson, Steve P; Kamiguti, Aura S; Theakston, R David G; Nesheim, Michael E; Laing, Gavin D

2006-04-07

289

Disintegrin-like/cysteine-rich domains of the reprolysin HF3: Site-directed mutagenesis reveals essential role of specific residues.  

PubMed

Little is known about the biochemical properties of the non-catalytic domains of snake venom metalloproteinases (SVMPs). The ECD sequence of the disintegrin-like domain (D-domain) has been assigned as the disintegrin motif and, recently, the hyper-variable region (HVR) of the cysteine-rich domain (C-domain) was suggested to constitute a potential protein-protein adhesive interface. Here we show that the recombinant C-domain of HF3, a hemorrhagic SVMP from Bothrops jararaca, as well as three peptides resembling its HVR, inhibit collagen-induced platelet aggregation, which indicates a role for the C-domain and its HVR in targeting HF3 to platelets. Site-directed mutagenesis was used for the first time to identify charged residues essential for the functionality of the disintegrin-like/cysteine-rich domains (DC-domains). Residues of the disintegrin loop (E467 and D469), and of the HVR (K568, K569 and K575) of HF3 were individually mutated to Ala. Interestingly, only the mutant D469A was obtained in soluble form in Escherichia coli and this single mutation caused loss of two functional activities of the DC-domains: inhibition of platelet aggregation and increase of leukocyte rolling in the microcirculation. In summary we demonstrate that the C-domain and its HVR are critical for HF3 to affect platelets and leukocytes, however, the disintegrin loop may be important for the functionality of the D-domain in the context of the C-domain. PMID:20955756

Menezes, Milene C; de Oliveira, Ana Karina; Melo, Robson L; Lopes-Ferreira, Mônica; Rioli, Vanessa; Balan, Andrea; Paes Leme, Adriana F; Serrano, Solange M T

2010-10-16

290

Proline rich-oligopeptides: Diverse mechanisms for antihypertensive action.  

PubMed

Bradykinin-potentiating peptides from Bothrops jararaca (Bj) discovered in the early 1960s, were the first natural inhibitors of the angiotensin-converting enzyme (ACE). These peptides belong to a large family of snake venom proline-rich oligopeptides (PROs). One of these peptides, Bj-PRO-9a, was essential for defining ACE as effective drug target and development of captopril, an active site-directed inhibitor of ACE used worldwide for the treatment of human arterial hypertension. Recent experimental evidences demonstrated that cardiovascular effects exerted by different Bj-PROs are due to distinct mechanisms besides of ACE inhibition. In the present work, we have investigated the cardiovascular actions of four Bj-PROs, namely Bj-PRO-9a, -11e, -12b and -13a. Bj-PRO-9a acts upon ACE and BK activities to promote blood pressure reduction. Although the others Bj-PROs are also able to inhibit the ACE activity and to potentiate the BK effects, our results indicate that antihypertensive effect evoked by them involve new mechanisms. Bj-PRO-11e and Bj-PRO-12b involves induction of [Ca(2+)]i transients by so far unknown receptor proteins. Moreover, we have suggested argininosuccinate synthetase and M3 muscarinic receptor as targets for cardiovascular effects elicited by Bj-PRO-13a. In summary, the herein reported results provide evidence that Bj-PRO-mediated effects are not restricted to ACE inhibition or potentiation of BK-induced effects and suggest different actions for each peptide for promoting arterial pressure reduction. The present study reveals the complexity of the effects exerted by Bj-PROs for cardiovascular control, opening avenues for the better understanding of blood pressure regulation and for the development of novel therapeutic approaches. PMID:23933300

Morais, Katia L P; Ianzer, Danielle; Miranda, José Rodolfo R; Melo, Robson L; Guerreiro, Juliano R; Santos, Robson A S; Ulrich, Henning; Lameu, Claudiana

2013-08-07

291

cDNA cloning and deduced amino acid sequence of prothrombin activator (ecarin) from Kenyan Echis carinatus venom.  

PubMed

The complete amino acid sequence of ecarin is deduced from the nucleotide sequence of a cDNA clone isolated by screening a venomous gland cDNA library of Kenyan Echis carinatus. The cDNA sequence with 2379 base pairs encodes an open reading frame of 616 amino acids with a remarkable sequence homology to the putative precursor protein of trigramin from Trimeresurus gramineus venom (61% identity) and a large hemorrhagin, jararhagin, from the pit viper Bothrops jararaca venom (62% identity). Thus, ecarin, as well as jararhagin and trigramin, is translated as a precursor protein, which may be processed posttranslationally. The ecarin proprotein has a "cysteine switch" motif (-Pro-Lys-Met-Cys-Gly-Val-) similar to that involved in the activation of matrix metalloproteinase zymogens. The processed mature protein consists of 426 amino acid residues (residues 191-616), showing the strongest sequence similarity with that of Russell's viper venom factor X activator (RVV-X) heavy chain (64% identity). Like RVV-X heavy chain, ecarin contains metalloproteinase, disintegrin, and cysteine-rich domains. The metalloproteinase domain has a typical zinc-chelating sequence (-His-Glu-Xaa-Xaa-His-Xaa-Xaa-Gly-Xaa-Xaa-His-), as found in crayfish astacin. In the disintegrin domain of ecarin, the Arg-Gly-Asp sequence is replaced by Arg-Asp-Asp, as found in the disintegrin domains of RVV-X heavy chain (Arg-Asp-Glu) and a guinea pig sperm fusion protein, PH-30 beta (Thr-Asp-Glu). These findings show that while there are structural and evolutionary relationships among these proteins, each has a unique functional activity. PMID:7849037

Nishida, S; Fujita, T; Kohno, N; Atoda, H; Morita, T; Takeya, H; Kido, I; Paine, M J; Kawabata, S; Iwanaga, S

1995-02-01

292

Neuromuscular action of venom from the South American colubrid snake Philodryas patagoniensis.  

PubMed

Snakes of the opisthoglyphous genus Philodryas are widespread in South America and cause most bites by colubrids in this region. In this study, we examined the neurotoxic and myotoxic effects of venom from Philodryas patagoniensis in biventer cervicis and phrenic nerve-diaphragm preparations and we compared the biochemical activities of venoms from P. patagoniensis and Philodryas olfersii. Philodryas patagoniensis venom (40 microg/mL) had no effect on mouse phrenic nerve-diaphragm preparations but caused time-dependent neuromuscular blockade of chick biventer cervicis preparations. This blockade was not reversed by washing. The highest concentration of venom tested (40 microg/mL) significantly reduced (p<0.05) the contractures to exogenous acetylcholine (55 microM and 110 microM) and K(+) (13.4 mM) after 120 min; lower concentrations of venom had no consistent or significant effect on these responses. Venom caused a concentration- and time-dependent release of creatine kinase (CK) from biventer cervicis preparations. Histological analysis showed contracted muscle fibers at low venom concentrations and myonecrosis at high concentrations. Philodryas venoms had low esterase and phospholipase A(2) but high proteolytic activities compared to the pitviper Bothrops jararaca. SDS-PAGE showed that the Philodryas venoms had similar electrophoretic profiles, with most proteins having a molecular mass of 25-80 kDa. Both of the Philodryas venoms cross-reacted with bothropic antivenom in ELISA, indicating the presence of proteins immunologically related to Bothrops venoms. RP-HPLC of P. patagoniensis venom yielded four major peaks, each of which contained several proteins, as shown by SDS-PAGE. These results indicate that P. patagoniensis venom has neurotoxic and myotoxic components that may contribute to the effects of envenoming by this species. PMID:18455482

Carreiro da Costa, Roberta S; Prudêncio, Luiz; Ferrari, Erika Fonseca; Souza, Gustavo H M F; de Mello, Sueli Moreira; Prianti Júnior, Antonio Carlos Guimarães; Ribeiro, Wellington; Zamunér, Stella Regina; Hyslop, Stephen; Cogo, José Carlos

2008-03-14

293

Argininosuccinate Synthetase Is a Functional Target for a Snake Venom Anti-hypertensive Peptide  

PubMed Central

Bj-BPP-10c is a bioactive proline-rich decapeptide, part of the C-type natriuretic peptide precursor, expressed in the brain and in the venom gland of Bothrops jararaca. We recently showed that Bj-BPP-10c displays a strong, sustained anti-hypertensive effect in spontaneous hypertensive rats (SHR), without causing any effect in normotensive rats, by a pharmacological effect independent of angiotensin-converting enzyme inhibition. Therefore, we hypothesized that another mechanism should be involved in the peptide activity. Here we used affinity chromatography to search for kidney cytosolic proteins with affinity for Bj-BPP-10c and demonstrate that argininosuccinate synthetase (AsS) is the major protein binding to the peptide. More importantly, this interaction activates the catalytic activity of AsS in a dose-de pend ent manner. AsS is recognized as an important player of the citrulline-NO cycle that represents a potential limiting step in NO synthesis. Accordingly, the functional interaction of Bj-BPP-10c and AsS was evidenced by the following effects promoted by the peptide: (i) increase of NO metabolite production in human umbilical vein endothelial cell culture and of arginine in human embryonic kidney cells and (ii) increase of arginine plasma concentration in SHR. Moreover, ?-methyl-dl-aspartic acid, a specific AsS inhibitor, significantly reduced the anti-hypertensive activity of Bj-BPP-10c in SHR. Taken together, these results suggest that AsS plays a role in the anti-hypertensive action of Bj-BPP-10c. Therefore, we propose the activation of AsS as a new mechanism for the anti-hypertensive effect of Bj-BPP-10c in SHR and AsS as a novel target for the therapy of hypertension-related diseases.

Guerreiro, Juliano R.; Lameu, Claudiana; Oliveira, Eduardo F.; Klitzke, Clecio F.; Melo, Robson L.; Linares, Edlaine; Augusto, Ohara; Fox, Jay W.; Lebrun, Ivo; Serrano, Solange M. T.; Camargo, Antonio C. M.

2009-01-01

294

The interaction of the antitoxin DM43 with a snake venom metalloproteinase analyzed by mass spectrometry and surface plasmon resonance.  

PubMed

DM43 is a circulating dimeric antitoxin isolated from Didelphis aurita, a South American marsupial naturally immune to snake envenomation. This endogenous inhibitor binds non-covalently to jararhagin, the main hemorrhagic metalloproteinase from Bothrops jararaca snake venom, and efficiently neutralizes its toxicity. The aim of this study was to apply mass spectrometry (MS) and surface plasmon resonance (SPR) to improve the molecular characterization of this heterocomplex. The stoichiometry of the interaction was confirmed by nanoelectrospray ionization-quadrupole-time-of-flight MS; from native solution conditions, the complex showed a molecular mass of ~94 kDa, indicating that one molecule of jararhagin (50 kDa) interacts with one monomer of DM43 (43 kDa). Although readily observed in solution, the dimeric structure of the inhibitor was barely preserved in the gas phase. This result suggests that, in contrast to the toxin-antitoxin complex, hydrophobic interactions are the primary driving force for the inhibitor dimerization. For the real-time interaction analysis, the toxin was captured on a sensor chip derivatized with the anti-jararhagin monoclonal antibody MAJar 2. The sensorgrams obtained after successive injections of DM43 in a concentration series were globally fitted to a simple bimolecular interaction, yielding the following kinetic rates for the DM43/jararhagin interaction: k(a) = 3.54 ± 0.03 × 10(4) M(-1) s(-1) and k(d) = 1.16 ± 0.07 × 10(-5) s(-1), resulting in an equilibrium dissociation constant (K(D) ) of 0.33 ± 0.06 nM. Taken together, MS and SPR results show that DM43 binds to its target toxin with high affinity and constitute the first accurate quantitative study on the extent of the interaction between a natural inhibitor and a metalloproteinase toxin, with unequivocal implications for the use of this kind of molecule as template for the rational development of novel antivenom therapies. PMID:22549991

Brand, Guilherme D; Salbo, Rune; Jørgensen, Thomas J D; Bloch, Carlos; Boeri Erba, Elisabetta; Robinson, Carol V; Tanjoni, Isabelle; Moura-da-Silva, Ana M; Roepstorff, Peter; Domont, Gilberto B; Perales, Jonas; Valente, Richard H; Neves-Ferreira, Ana G C

2012-05-01

295

Clinical toxinology--where are we now?  

PubMed

Clinical toxinology encompasses a broad range of medical conditions resulting from envenomation by venomous terrestrial and marine organisms, and also poisoning from ingestion of animal and plant toxins. Toxin-related disease is an important cause of morbidity and mortality worldwide, particularly in the tropical and subtropical continents. Snake bite is the single most important toxin-related disease, causing substantial mortality in many parts of Africa, Asia, and the Americas. The most important snake families are Viperidae and Elapidae, causing a range of clinical effects including local necrosis, neurotoxicity, coagulopathy and hemorrhage, myotoxicity and renal toxicity. These effects vary according to geography and group of snake. Arachnid envenomation results mainly in morbidity, particularly scorpion stings which can cause severe systemic envenomation. Spider bite is far less of a problem, and the majority of medically important cases can be attributed to widow spiders (Latrodectus spp.) and recluse spiders (Loxosceles spp.). Marine-related envenomations are common, but severe effects are less so. Plant and mushroom poisoning occur in most parts of the world, but the types and methods of poisoning vary considerably between continents. Management of toxin-related disease is often difficult, and in many cases meticulous supportive care is all that is available. The mainstay of treatment is the use of antivenoms for many envenomations and poisoning, although these do not exist for all dangerous organisms. Unfortunately antivenoms are not an economically viable product, so development and manufacture of these agents have been limited. This is now further worsened by a current shortage of antivenom. There is a need for improvement in the preventionand management of toxin-related disease. This will require well-designed studies to define the extent of the problem, initiatives to improve the prevention and management of these conditions, and development of new, and continuation of current, antivenom supplies. PMID:12807310

White, Julian; Warrell, David; Eddleston, Michael; Currie, Bart J; Whyte, Ian M; Isbister, Geoffrey K

2003-01-01

296

Snake bite in Nigeria.  

PubMed

Four families of venomous snakes are found in Nigeria--Viperidae, Elapidae, Colubridae and Actraspididae but three species carpet viper (Echis ocellatus), black-necked spitting cobra (Naja nigricollis) and puff adder (Bitis arietans), belonging to the first two families, are the most important snakes associated with envenoming in Nigeria. The incidence of bites has been reported as 497 per 100,000 population per year with a 12 percent natural mortality, with Echis ocellatus accounting for at least 66 percent in certain foci. Bites occur more often while victims were farming, herding or walking although the spitting cobra may bite victims who roll upon it in their sleep. Carpet viper venom contains a prothrombin activating procoagulant, haemorrhagin and cytolytic fractions which cause haemorrhage, incoagulable blood, shock and local reactions/ necrosis. The spitting cobra bite manifests with local tissue reaction and occassionally with bleeding from the site of bite, but no classic neurotoxic feature has been observed except following Egyptian cobra (N. haje) bites. Cardiotoxicity and renal failure may occassionally occur following bites by the carpet viper and the puff adder. In the laboratory, haematological and other features are noted and immunodiagnosis has a role in species identification. Immobilisation of the bitten limb is probably the single most important first aid measure. Antivenom should be used cautiously when indicated. As only 8.5 percent of snake bite victims attend hospitals in Nigeria, health education should be the main preventive measure, mean-while, the study of immunisation of occupationally predisposed individuals in endemic areas should be intensified. A new Fab fragment antivenom specific to Nigerian Echis ocellatus was investigated clinically, just as the local herbs-Aristolochia spp, Guiera spp and Schummaniophyton spp are investigated experimentally. PMID:14510123

Habib, A G; Gebi, U I; Onyemelukwe, G C

2001-09-01

297

Isolation and characterization of two disintegrins inhibiting ADP-induced human platelet aggregation from the venom of Crotalus scutulatus scutulatus (Mohave Rattlesnake)  

SciTech Connect

Disintegrins and disintegrin-like proteins are molecules found in the venom of four snake families (Atractaspididae, Elapidae, Viperidae, and Colubridae). The disintegrins are nonenzymatic proteins that inhibit cell-cell interactions, cell-matrix interactions, and signal transduction, and may have potential in the treatment of strokes, heart attacks, cancers, and osteoporosis. Prior to 1983, the venom of Crotalus scutulatus scutulatus (Mohave Rattlesnake) was known to be only neurotoxic; however, now there is evidence that these snakes can contain venom with: (1) neurotoxins; (2) hemorrhagins; and (3) both neurotoxins and hemorrhagins. In this study, two disintegrins, mojastin 1 and mojastin 2, from the venom of a Mohave rattlesnake collected in central Arizona (Pinal County), were isolated and characterized. The disintegrins in these venoms were identified by mass-analyzed laser desorption ionization/time-of-flight/time-of-flight (MALDI/TOF/TOF) mass spectrometry as having masses of 7.436 and 7.636 kDa. Their amino acid sequences are similar to crotratroxin, a disintegrin isolated from the venom of the western diamondback rattlesnake (C. atrox). The amino acid sequence of mojastin 1 was identical to the amino acid sequence of a disintegrin isolated from the venom of the Timber rattlesnake (C. horridus). The disintegrins from the Mohave rattlesnake venom were able to inhibit ADP-induced platelet aggregation in whole human blood both having IC{sub 5}s of 13.8 nM, but were not effective in inhibiting the binding of human urinary bladder carcinoma cells (T24) to fibronectin.

Sanchez, Elda E. [Natural Toxins Research Center, College of Arts and Science, 920 University Blvd. MSC 158, Texas A and M University-Kingsville, MSC 158, Kingsville, TX 78363 (United States); Galan, Jacob A. [Natural Toxins Research Center, College of Arts and Science, 920 University Blvd. MSC 158, Texas A and M University-Kingsville, MSC 158, Kingsville, TX 78363 (United States); Russell, William K. [Laboratory for Biological Mass Spectrometry, Department of Chemistry, PO Box 30012, Texas A and M University, College Station, TX 77842-3013 (United States); Soto, Julio G. [Department of Biological Sciences, One Washington Square Duncan Hall, San Jose State University, San Jose, CA 95192-0100 (United States); Russell, David H. [Laboratory for Biological Mass Spectrometry, Department of Chemistry, PO Box 30012, Texas A and M University, College Station, TX 77842-3013 (United States); Perez, John C. [Natural Toxins Research Center, College of Arts and Science, 920 University Blvd. MSC 158, Texas A and M University-Kingsville, MSC 158, Kingsville, TX 78363 (United States)]. E-mail: kfjcp00@tamuk.edu

2006-04-01

298

A survey of hemoparasite infections in free-ranging mammals and reptiles in French Guiana.  

PubMed

Blood smears of 1,353 free-ranging mammals (35 species) and 112 reptiles (31 species) from French Guiana were examined for hemoparasites. Parasites from 3 major groups were recorded: Apicomplexa (including hemogregarines, piroplasms, and Plasmodium spp.), Trypanosomatidae, and Filaroidea. Fifty percent of the individuals (86% of the species) were infected by parasites from at least 1 group. Hemogregarines, identified as Hepatozoon sp., infected numerous snakes with high prevalences (30-100%); infection is reported for the first time in 5 host genera of snakes: Clelia, Oxybelis, Pseustes, Rhinobotryum, and Bothriopsis. Infections were also observed in 4 marsupial species and 1 rodent. Hepatozoon spp. recorded in Didelphis albiventris (Marsupialia) and Coendou prehensilis (Rodentia) may be new species. Plasmodium sp. were observed in 2 snake species, Dipsas indica (Colubridae) and Bothrops atrox (Viperidae). Plasmodium brasilianum was recorded in all 5 primate species examined. Piroplasms were observed in all mammal orders except primates. Large terrestrial rodents were the main hosts of members of the Babesidae; 42% of Myoprocta acouchy, 36% of Dasyprocta agouti, and 44% of Agouti paca were infected. Trypanosomes were common in mammals and were recorded in 70% of the examined genera. Trypanosoma cruzi-like infections were reported in 21 mammal species, including sloths, rodents, carnivores, and primates. Microfilariae were also widespread, with higher prevalences in sloths, anteaters, and porcupines (>40% of the individuals infected) and in tamarins (95% infected). This survey highlights some potential anthropozoonotic risks due to the recent further evidence of Plasmodium brasilianum and P. malariae as a single species and to the increased diversity of hosts for Trypanosoma cruzi. PMID:11128476

de Thoisy, B; Michel, J C; Vogel, I; Vié, J C

2000-10-01

299

Structural and Functional Studies of a Bothropic Myotoxin Complexed to Rosmarinic Acid: New Insights into Lys49-PLA2 Inhibition  

PubMed Central

Snakebite envenoming is an important public health problem in many tropical and subtropical countries, and is considered a neglected tropical disease by the World Health Organization. Most severe cases are inflicted by species of the families Elapidae and Viperidae, and lead to a number of systemic and local effects in the victim. One of the main problems regarding viperidic accidents is prominent local tissue damage whose pathogenesis is complex and involves the combined actions of a variety of venom components. Phospholipases A2 (PLA2s) are the most abundant muscle-damaging components of these venoms. Herein, we report functional and structural studies of PrTX-I, a Lys49-PLA2 from Bothops pirajai snake venom, and the influence of rosmarinic acid (RA) upon this toxin's activities. RA is a known active component of some plant extracts and has been reported as presenting anti-myotoxic properties related to bothopic envenomation. The myotoxic activity of Lys49-PLA2s is well established in the literature and although no in vivo neurotoxicity has been observed among these toxins, in vitro neuromuscular blockade has been reported for some of these proteins. Our in vitro studies show that RA drastically reduces both the muscle damage and the neuromuscular blockade exerted by PrTX-I on mice neuromuscular preparations (by ?80% and ?90%, respectively). These results support the hypothesis that the two effects are closely related and lead us to suggest that they are consequences of the muscle membrane-destabilizing activity of the Lys49-PLA2. Although the C-terminal region of these proteins has been reported to comprise the myotoxic site, we demonstrate by X-ray crystallographic studies that RA interacts with PrTX-I in a different region. Consequently, a new mode of Lys49-PLA2 inhibition is proposed. Comparison of our results with others in the literature suggests possible new ways to inhibit bothropic snake venom myotoxins and improve serum therapy.

dos Santos, Juliana I.; Cardoso, Fabio F.; Soares, Andreimar M.; dal Pai Silva, Maeli; Gallacci, Marcia; Fontes, Marcos R. M.

2011-01-01

300

In vivo evaluation of homeostatic effects of Echis carinatus snake venom in Iran  

PubMed Central

Background The venom of the family Viperidae, including the saw-scaled viper, is rich in serine proteinases and metalloproteinases, which affect the nervous system, complementary system, blood coagulation, platelet aggregation and blood pressure. One of the most prominent effects of the snake venom of Echis carinatus (Ec) is its coagulation activity, used for killing prey. Materials and methods Subfractions F1A and F1B were isolated from Ec crude venom by a combination of gel chromatography (Sephadex G-75) and ion exchange chromatography on a DEAE-Sepharose (DE-52). These subfractions were then intravenously (IV) injected into NIH male mice. Blood samples were taken before and after the administration of these subfractions. Times for prothrombin, partial thromboplastin and fibrinogen were recorded. Results and conclusions Comparison of the prothrombin time before and after F1A and F1B administrations showed that time for blood coagulation after injection is shorter than that of normal blood coagulation and also reduced coagulation time after Ec crude venom injection. This difference in coagulation time shows the intense coagulation activity of these subfractions that significantly increase the coagulation cascade rate and Causes to quick blood coagulation. The LD50 of the Ec crude venom was also determined to be 11.1 ?g/mouse. Different crude venom doses were prepared with physiological serum and injected into four mice. Comparison of the prothrombin times after injection of subfractions F1A and F1B showed that the rate of mouse blood coagulation increases considerably. Comparing the partial thromboplastin times after injecting these subfractions with this normal test time showed that the activity rate of intrinsic blood coagulation system rose sharply in mice. Finally, by comparing the fibrinogen time after subfraction injections and normal test time, we can infer intense activation of coagulation cascade and fibrin production.

2013-01-01

301

Global richness patterns of venomous snakes reveal contrasting influences of ecology and history in two different clades.  

PubMed

Recent studies addressing broad-scale species richness gradients have proposed two main primary drivers: contemporary climate and evolutionary processes (differential balance between speciation and extinction). Here, we analyze the global richness patterns of two venomous snake clades, Viperidae and Elapidae. We used ordinary least squares multiple regression (OLS) and partial regression analysis to investigate to what extent actual evapotranspiration (AET; summarizing current environmental conditions) and biogeographical regions (representing evolutionary effects) were associated with species richness. For viperids, AET explained 45.6% of the variance in richness whereas the effect of this variable for elapids was almost null (0.5%). On the other hand, biogeographic regions were the best predictors of elapid richness (56.5%), against its relatively small effect (25.9%) in viperid richness. Partial regressions also revealed similar patterns for independent effects of climate and history in both clades. However, the independent historical effect in Elapidae decreased from 45.2 to 17.8% when we excluded Australia from the analyses, indicating that the strong historical effect that had emerged for the global richness pattern was reflecting the historical process of elapid radiation into Australia. Even after excluding Australia, the historical signal in elapid richness in the rest of the globe was still significant and much higher than that observed in viperid richness at a global scale (2.7% after controlling for AET effects). Differences in the evolutionary age of these two clades can be invoked to explain these contrasting results, in that viperids probably had more time for diversification, generating richness responses to environmental gradients, whereas the pattern of distribution of elapid richness can be more directly interpreted in an evolutionary context. Moreover, these results show the importance of starting to adopt deconstructive approaches to species richness, since the driving factors of these patterns may vary from group to group according to their evolutionary history. PMID:19101733

Terribile, Levi Carina; Olalla-Tárraga, Miguel Angel; Morales-Castilla, Ignacio; Rueda, Marta; Vidanes, Rosa M; Rodríguez, Miguel Angel; Diniz-Filho, José Alexandre Felizola

2008-12-20

302

Acute renal failure in snake envenomation: a large prospective study.  

PubMed

Venomous snakebite is a common problem in India. The aim of this study is to assess the prevalence, risk factors and prognostic factors in snakebite induced acute renal failure and to determine their outcome from a tertiary care center in India. A total of 1548 cases of snakebite admitted to adult medical wards of Government Rajaji hospital from January 2003 to December 2004, were studied from hospitalization to discharge or death. There were 1180 poisonous and 368 nonpoisonous snakebites. Among the poisonous, there were 1121 viperidae and 59 elapidae bites. A total of 159 (13.5%) patients (M = 98, F = 61) developed acute renal failure; of them 72 (45.3%) required dialysis and 36 (22.6%) expired (of them, 23 required dialysis). ARF patients were older than non ARF (39.1 vs. 35.4 years, p = 0.03). Cellulites (OR 9.20, p = 0.032), regional lymphadenopathy (OR 22.0, p= 0.001), intravascular hemolysis (OR 3.70, p = 0.004) and bite to needle time more than 2 hours (OR 2.10, p = 0.001) were identified as independent risk factors for the development of acute renal failure. Bite to needle time more than 2 hours (OR 2.10, p = 0.01), presence of intravascular hemolysis (OR 13.0, p = 0.004) and hypotension (OR 22.2, p = 0.04) and the presence of bleeding manifestations (OR 7.91, p = 0.032) were identified as independent predictors of poor outcome in snakebite victims. We conclude that our study demonstrates several risk factors and predictors for the development and outcome of ARF in patients with snakebites. PMID:18445901

Athappan, Ganesh; Balaji, M Vijay; Navaneethan, Udhayakumar; Thirumalikolundusubramanian, P

2008-05-01

303

Cytotoxicity induced in myotubes by a Lys49 phospholipase A2 homologue from the venom of the snake Bothrops asper: evidence of rapid plasma membrane damage and a dual role for extracellular calcium.  

PubMed

Acute muscle tissue damage, myonecrosis, is a typical consequence of envenomations by snakes of the family Viperidae. Catalytically-inactive Lys49 phospholipase A(2) homologues are abundant myotoxic components in viperid venoms, causing plasma membrane damage by a mechanism independent of phospholipid hydrolysis. However, the precise mode of action of these myotoxins remains unsolved. In this work, a cell culture model of C2C12 myotubes was used to assess the action of Bothrops asper myotoxin II (Mt-II), a Lys49 phospholipase A(2) homologue. Mt-II induced a dose- and time-dependent cytotoxic effect associated with plasma membrane disruption, evidenced by the release of the cytosolic enzyme lactate dehydrogenase and the penetration of propidium iodide. A rapid increment in cytosolic Ca(2+) occurred after addition of Mt-II. Such elevation was associated with hypercontraction of myotubes and blebbing of plasma membrane. An increment in the Ca(2+) signal was observed in myotube nuclei. Elimination of extracellular Ca(2+) resulted in increased cytotoxicity upon incubation with Mt-II, suggesting a membrane-protective role for extracellular Ca(2+). Chelation of cytosolic Ca(2+) with BAPTA-AM did not modify the cytotoxic effect, probably due to the large increment induced by Mt-II in cytosolic Ca(2+) which overrides the chelating capacity of BAPTA-AM. It is concluded that Mt-II induces rapid and drastic plasma membrane lesion and a prominent Ca(2+) influx in myotubes. Extracellular Ca(2+) plays a dual role in this model: it protects the membrane from the cytolytic action of the toxin; at the same time, the Ca(2+) influx that occurs after membrane disruption is likely to play a key role in the intracellular degenerative events associated with Mt-II-induced myotube damage. PMID:17560765

Villalobos, Juan Carlos; Mora, Rodrigo; Lomonte, Bruno; Gutiérrez, José María; Angulo, Yamileth

2007-04-29

304

Stable isotope tracer reveals that viviparous snakes transport amino acids to offspring during gestation.  

PubMed

Viviparity and placentation have evolved from oviparity over 100 times in squamate reptiles (lizards and snakes). The independent origins of placentation have resulted in a variety of placental morphologies in different taxa, ranging from simple apposition of fetal and maternal tissues to endotheliochorial implantation that is homoplasious with mammalian placentation. Because the eggs of oviparous squamates transport gases and water from the environment and calcium from the eggshell, the placentae of viviparous squamates are thought to have initially evolved to accomplish these functions from within the maternal oviduct. Species with complex placentae have also been shown to rely substantially, or even primarily, on placental transport of organic nutrients for embryonic nutrition. However, it is unclear whether species with only simple placentae are also capable of transporting organic nutrients to offspring. Among viviparous squamates, all of the snakes that have been studied thus far have been shown to have simple placentae. However, most studies of snake placentation are limited to a single lineage, the North American Natricinae. We tested the abilities of four species of viviparous snakes - Agkistrodon contortrix (Viperidae), Boa constrictor (Boidae), Nerodia sipedon (Colubridae: Natricinae) and Thamnophis sirtalis (Colubridae: Natricinae) - to transport diet-derived amino acids to offspring during gestation. We fed [(15)N]leucine to pregnant snakes, and compared offspring (15)N content with that of unlabeled controls. Labeled females allocated significantly more (15)N to offspring than did controls, but (15)N allocation did not differ among species. Our results indicate that viviparous snakes are capable of transporting diet-derived amino acids to their offspring during gestation, possibly via placentation. PMID:22323198

Van Dyke, James U; Beaupre, Steven J

2012-03-01

305

Reproduction in female copperhead snakes (Agkistrodon contortrix): plasma steroid profiles during gestation and post-birth periods.  

PubMed

We investigated levels of plasma progesterone (P4), 17?-estradiol (E2), testosterone (T), and corticosterone (CORT) during gestation and post-birth periods in wild-collected female copperhead snakes (Viperidae; Agkistrodon contortrix). We also sought to determine whether CORT levels at (or near) birth dramatically increase and were correlated with duration of labor and litter size. Specifically, pregnant subjects (N = 14) were collected during early- to mid-gestation, held in the laboratory, and repeatedly bled to obtain plasma for steroid analyses. Progesterone showed significant changes during gestation, with the highest levels at the onset of sampling (circa 50 days prior to birth); P4 progressively declined up to parturition, and basal levels were observed thereafter. At the onset of sampling, E2 was at peak levels and fell sharply at circa 30 days prior to birth, a trend observed throughout the post-birth sampling period. Throughout the entire sampling period, T was undetectable. Although CORT showed no significant changes during gestation and several days following parturition, there was a highly significant peak at the time of birth. Our findings mirror the results of previous studies on pregnancy and steroid hormones of other live-bearing snakes, lizards, and mammals. As expected, there was a significant relationship between duration of labor and litter size; however, although levels of CORT did not achieve significance, there was a positive trend with litter size. We suggest that elevation of CORT at birth is involved in the mobilization and regulation of energy stores necessary for the physiological process of parturition and as a possible mechanism to trigger birth. PMID:22468838

Smith, Charles F; Schuett, Gordon W; Hoss, Shannon K

2012-04-01

306

CURRENT BUILDUP IN EMERGING SERPENTINE FLUX TUBES  

SciTech Connect

The increase of magnetic flux in the solar atmosphere during active-region formation involves the transport of the magnetic field from the solar convection zone through the lowest layers of the solar atmosphere, through which the plasma {beta} changes from >1 to <1 with altitude. The crossing of this magnetic transition zone requires the magnetic field to adopt a serpentine shape also known as the sea-serpent topology. In the frame of the resistive flux-emergence model, the rising of the magnetic flux is believed to be dynamically driven by a succession of magnetic reconnections which are commonly observed in emerging flux regions as Ellerman bombs. Using a data-driven, three-dimensional (3D) magnetohydrodynamic numerical simulation of flux emergence occurring in active region 10191 on 2002 November 16-17, we study the development of 3D electric current sheets. We show that these currents buildup along the 3D serpentine magnetic-field structure as a result of photospheric diverging horizontal line-tied motions that emulate the observed photospheric evolution. We observe that reconnection can not only develop following a pinching evolution of the serpentine field line, as usually assumed in two-dimensional geometry, but can also result from 3D shearing deformation of the magnetic structure. In addition, we report for the first time on the observation in the UV domain with the Transition Region and Coronal Explorer (TRACE) of extremely transient loop-like features, appearing within the emerging flux domain, which link several Ellermam bombs with one another. We argue that these loop transients can be explained as a consequence of the currents that build up along the serpentine magnetic field.

Pariat, E. [Space Weather Laboratory, NASA Goddard Space Flight Center Greenbelt, MD 20771 (United States); Masson, S.; Aulanier, G. [LESIA, Observatoire de Paris, CNRS, UPMC, Universite Paris Diderot, 5 place Jules Janssen, 92190 Meudon (France)], E-mail: epariat@helio.gsfc.nasa.gov

2009-08-20

307

The drumstick gene acts cell-non-autonomously and triggers specification of the small intestine in the Drosophila hindgut.  

PubMed

An odd family gene drumstick (drm) encodes a zinc finger protein, and is necessary for the development of the small intestine, an anterior domain of the ectodermal hindgut of Drosophila melanogaster. However, mechanisms that specify the small intestine, as well as gene regulatory pathways leading to transcriptional activation of drm, are still unclear. We found that drm is expressed in two different tissues abutting the anterior end of the hindgut primordium, that is, the posterior-most region of the midgut (endoderm) and basal portion of the Malpighian tubules. A small intestine marker gene, unpaired (upd), begins to be expressed at the anterior-most region of the hindgut primordium that abuts the basal portion of Malpighian tubules, and the upd-positive region expands, resulting in a short tube during stages 11-13. The small intestine develops in both of the mutant embryos, serpent (srp) and Krüppel (Kr), that lack the drm-positive midgut or Malpighian tubules, respectively, while it fails to develop in the Kr srp double-mutant embryos that lack both of the drm-positive tissues. These results demonstrate that drm expressed in the abutting tissues cell-non-autonomously induces development of the small intestine in the hindgut primordium, probably by deploying some extracellular signaling factor. drm expression in the posterior gut region disappears and the small intestine fails to form in tailless (tll) mutant embryos, whereas over-expression of tll causes expansion of drm expression throughout the midgut, inducing a longer small intestine. These results indicate that drm is activated under the control of tll and triggers development of the small intestine cell-non-autonomously through some extracellular signaling. PMID:22252491

Uddin, Sarder N; Yano, Masahiro; Murakami, Ryutaro

2011-01-01

308

Detecting Mantle Anisotropy with Marine CSEM Sounding  

NASA Astrophysics Data System (ADS)

We can detect transverse electrical anisotropy in the oceanic crust and upper mantle using circular transmitter tows around a pair of highly sensitive controlled-source electromagnetic (CSEM) receivers. Our long-wire electromagnetic (LEM) receivers, equipped with 100-200 m antennas, improve signal to noise by about an order of magnitude over standard EM receivers using 8-10 m antennas. LEMs work well in deep water where voltage noise from electrodes and amplifiers dominates, and electric field noise from magnetotelluric signals and water motion is low. When combined with SUESI, our marine EM transmitter, which emits 300 amps across a 250 m antenna, noise floors of 10-17~V/Am2 may be obtained at 2-4 Hz over 40-minute stacks. Towing a transmitter in a 30 km circle around an orthogonal pair of LEMs samples propagation though the crust and upper mantle in all horizontal directions. This purely azimuthal geometry generates linearly polarized data for an isotropic earth, but in the presence of anisotropy the minor axis of the polarization ellipse develops a characteristic clover-leaf pattern when plotted against source-receiver direction, and the major axis becomes elongated. We have conducted such experiments on 40 Ma lithosphere offshore California (the APPLE experiment), and 24 Ma lithosphere as it subducts into the Nicaraguan trench (part of the SERPENT expedition). Both regions produce remarkably similar results, with increased conductivity in the fossil ridge-parallel directions, which we interpret to be caused by serpentinized mantle-penetrating faults. This pattern of anisotropy is modified in the outer rise of the trench, as the lithosphere bends and shallower (crustal) fractures develop.

Constable, S.; Key, K. W.; Behrens, J. P.; MacGregor, L.; Evans, R. L.

2010-12-01

309

Evolution of the mitochondrial genome in snakes: Gene rearrangements and phylogenetic relationships  

PubMed Central

Background Snakes as a major reptile group display a variety of morphological characteristics pertaining to their diverse behaviours. Despite abundant analyses of morphological characters, molecular studies using mitochondrial and nuclear genes are limited. As a result, the phylogeny of snakes remains controversial. Previous studies on mitochondrial genomes of snakes have demonstrated duplication of the control region and translocation of trnL to be two notable features of the alethinophidian (all serpents except blindsnakes and threadsnakes) mtDNAs. Our purpose is to further investigate the gene organizations, evolution of the snake mitochondrial genome, and phylogenetic relationships among several major snake families. Results The mitochondrial genomes were sequenced for four taxa representing four different families, and each had a different gene arrangement. Comparative analyses with other snake mitochondrial genomes allowed us to summarize six types of mitochondrial gene arrangement in snakes. Phylogenetic reconstruction with commonly used methods of phylogenetic inference (BI, ML, MP, NJ) arrived at a similar topology, which was used to reconstruct the evolution of mitochondrial gene arrangements in snakes. Conclusion The phylogenetic relationships among the major families of snakes are in accordance with the mitochondrial genomes in terms of gene arrangements. The gene arrangement in Ramphotyphlops braminus mtDNA is inferred to be ancestral for snakes. After the divergence of the early Ramphotyphlops lineage, three types of rearrangements occurred. These changes involve translocations within the IQM tRNA gene cluster and the duplication of the CR. All phylogenetic methods support the placement of Enhydris plumbea outside of the (Colubridae + Elapidae) cluster, providing mitochondrial genomic evidence for the familial rank of Homalopsidae.

Yan, Jie; Li, Hongdan; Zhou, Kaiya

2008-01-01

310

Release of Oceanic Intraplate Magmatic CO2, Carbonatization, and Decarbonatization Reactions in the Lower Oceanic Lithosphere and Subducting Slabs and Associated Intraplate and Intraslab Earthquakes  

NASA Astrophysics Data System (ADS)

Release of free CO2 from ascending mafic magmas is thought to be important for intraplate magmatic systems under the ocean basins and gives insight into the cause of deep mantle earthquakes such as those that occur under the Island of Hawai'i at depths of 20 to 60 km via pore-pressure effects. Moreover, this hypothesis is consistent with the occurrence of CO2-filled inclusions along healed fractures in mantle xenoliths in Hawai'ian in ultramafic xenoliths of presumed mantle or deep-crustal origin. The positive pressure effect on CO2 solubility in mafic melts implies that this volatile boils out of such magmas as they ascend and enables fracture and frictional sliding at mantle depths by reducing the effective normal stresses. It is likely that such CO2 is stored along such fractures and faults during the active stage of plume magmatic activity and that during cooling, this CO2 reacts with mantle silicates to form magnesite and dolomite as oceanic lithosphere cools. Such carbonates are much weaker than mantle peridotites (Holyoke and Kronenberg, this session) and are therefore expected to localize strain along such carbonated zones where the oceanic plate is under tectonic stresses. Such conditions are found in the zone of bending near trenches and within subducting slabs where double zones of seismicity are locally present. Localized plastic deformation and viscous heating leading to free CO2 release through decarbonatization and perhaps melting may enable seismogenesis at such depths in mantle lithosphere. This model for the lower zones of double seismic zones where the enabling fluid comes from below the plate from plume magmatic processes (Kirby, 1995; Seno and Yamanaka, 1996) is much more appealing than positing fluid penetration and serpentization downward through the entire oceanic lithosphere from the ocean floor followed by serpentinite dehydration upon subsequent heating during slab descent.

Kirby, S. H.

2011-12-01

311

Current Buildup in Emerging Serpentine Flux Tubes  

NASA Astrophysics Data System (ADS)

The increase of magnetic flux in the solar atmosphere during active-region formation involves the transport of the magnetic field from the solar convection zone through the lowest layers of the solar atmosphere, through which the plasma ? changes from >1 to <1 with altitude. The crossing of this magnetic transition zone requires the magnetic field to adopt a serpentine shape also known as the sea-serpent topology. In the frame of the resistive flux-emergence model, the rising of the magnetic flux is believed to be dynamically driven by a succession of magnetic reconnections which are commonly observed in emerging flux regions as Ellerman bombs. Using a data-driven, three-dimensional (3D) magnetohydrodynamic numerical simulation of flux emergence occurring in active region 10191 on 2002 November 16-17, we study the development of 3D electric current sheets. We show that these currents buildup along the 3D serpentine magnetic-field structure as a result of photospheric diverging horizontal line-tied motions that emulate the observed photospheric evolution. We observe that reconnection can not only develop following a pinching evolution of the serpentine field line, as usually assumed in two-dimensional geometry, but can also result from 3D shearing deformation of the magnetic structure. In addition, we report for the first time on the observation in the UV domain with the Transition Region and Coronal Explorer (TRACE) of extremely transient loop-like features, appearing within the emerging flux domain, which link several Ellermam bombs with one another. We argue that these loop transients can be explained as a consequence of the currents that build up along the serpentine magnetic field.

Pariat, E.; Masson, S.; Aulanier, G.

2009-08-01

312

Chimeric creatures in Greek mythology and reflections in science.  

PubMed

"The Chimaera" in Homer's Iliad, "was of divine stock, not of men, in the forepart a lion, in the hinder a serpent, and in the midst a goat, ellipsis Bellerophon slew her, trusting in the signs of the gods." In Hesiod's Theogony it is emphasized that "Chimaera ellipsis had three heads, one of a grim-eyed lion, another of a goat, and another of a snakeellipsis". In addition to this interspecies animal chimera, human/animal chimeras are referred to in Greek mythology, preeminent among them the Centaurs and the Minotaur. The Centaurs, as horse/men, first appear in Geometric and early Archaic art, but in the literature not until early in the fifth century B.C. The bullheaded-man Minotaur, who is not certainly attested in the literary evidence until circa 500 B.C., first appears in art about 650 B.C. Attempts, in the fourth century B.C. and thereafter, to rationalize their mythical appearance were in vain; their chimeric nature retained its fascinating and archetypal form over the centuries. Early in the 1980s, experimental sheep/goat chimeras were produced removing the reproductive barrier between these two animal species. Late in the 1990s, legal, political, ethical, and moral fights loomed over a patent bid on human/animal chimeras. Chimeric technology is recently developed; however, the concept of chimerism has existed in literary and artistic form in ancient mythology. This is yet another example where art and literature precede scientific research and development. PMID:11337752

Bazopoulou-Kyrkanidou, E

2001-04-15

313

Controls on melt migration and extraction at the ultraslow Southwest Indian Ridge 10°-16°E  

NASA Astrophysics Data System (ADS)

Crustal thickness variations at the ultraslow spreading 10-16°E region of the Southwest Indian Ridge are used to constrain melt migration processes. In the study area, ridge morphology correlates with the obliquity of the ridge axis with respect to the spreading direction. A long oblique "supersegment", nearly devoid of magmatism, is flanked at either end by robust magmatic centers (Joseph Mayes Seamount and Narrowgate segment) of much lesser obliquity. Plate-driven mantle flow and temperature structure are calculated in 3-D based on the observed ridge segmentation. Melt extraction is assumed to occur in three steps: (1) vertical migration out of the melting region, (2) focusing along an inclined permeability barrier, and (3) extraction when the melt enters a region shallower than ˜35 km within 5 km of the ridge axis. No crust is predicted in our model along the oblique supersegment. The formation of Joseph Mayes Seamount is consistent with an on-axis melt anomaly induced by the local orthogonal spreading. The crustal thickness anomaly at Narrowgate results from melt extracted at a tectonic damage zone as it travels along the axis toward regions of lesser obliquity. Orthogonal spreading enhances the Narrowgate crustal thickness anomaly but is not necessary for it. The lack of a residual mantle Bouguer gravity high along the oblique supersegment can be explained by deep serpentization of the upper mantle permissible by the thermal structure of this ridge segment. Buoyancy-driven upwelling and/or mantle heterogeneities are not required to explain the extreme focusing of melt in the study area.

MontéSi, Laurent G. J.; Behn, Mark D.; Hebert, Laura B.; Lin, Jian; Barry, Jennifer L.

2011-10-01

314

Sun-Earth Day 2005: Ancient Observatories: Timeless Knowledge  

NASA Astrophysics Data System (ADS)

The NASA Sun-Earth Connection Education Forum (SECEF) annually promotes an event called Sun-Earth Day. For Sun-Earth Day 2005 SECEF has selected a theme called "Ancient Observatories: Timeless Knowledge. This year's Sun-Earth Day theme is your ticket to a fascinating journey through time as we explore centuries of sun watching by a great variety of cultures. From ancient solar motion tracking to modern solar activity monitoring the Sun has always occupied an important spot in mankind's quest to understand the Universe. Sun-Earth Day events usually are centered on the spring equinox around March 21, but this year there has already been a webcast from the San Francisco Exploratorium and the Native American ruins at Chaco Canyon, New Mexico on the day of winter solstice 2004. There will be another webcast on March 20 live from Chichen Itza, Mexico highlighting the solar alignment that makes a serpent appear on one of the ancient pyramids. The website http://sunearthday.nasa.gov has been developed to provide the necessary resources and opportunities for participation by scientists and educators in giving school or general public programs about Sun-Earth Day. The goal is to involve as much of the student population and the public in this event as possible and to help them understand the importance of the Sun for ancient and modern peoples. Through engaging activities available on the website, classrooms and museums can create their own event or participate in one of the opportunities we make available. Scientists, educators, amateur astronomers, and museums are invited to register on the website to receive a free packet of materials about Sun-Earth Day for use in making presentations or programs about the event. Past and future Sun-Earth Days will be discussed as well.

Thieman, J. R.; Cline, T.; Lewis, E.; Hawkins, I.; Odenwald, S.; Mayo, L.

2005-05-01

315

Developmental sequences of squamate reptiles are taxon specific.  

PubMed

Recent studies in comparative vertebrate embryology have focused on two related questions. One concerns the existence of a phylotypic period, or indeed any period, during development in which sequence variation among taxa is constrained. The second question concerns the degree to which developmental characters exhibit a phylogenetic signal. These questions are important because they underpin attempts to understand the evolution of developmental characters and their links to adult morphology. To address these questions, we compared the sequence of developmental events spanning the so-called phylotypic period of vertebrate development in squamate reptiles (lizards and snakes), from the formation of the primary optic placode to the first appearance of scale anlagen. We used Bayesian phylogenetic ancestral state reconstruction analyses and estimates of Bayesian posterior probabilities of the rank order of developmental events to determine the level of support for phylogenetically associated variation in development. We assessed the amount of variation in event sequences by plotting the proportions of reconstructed ranks (excluding unlikely events, PP?Serpentes are distinguished by the earlier completion of torsion (rank 3) compared to acrodonts and pleurodonts (ranks 7 and 5, respectively). Clade specific sequences of developmental events mean that investigators should not extend observations on the development on particular squamate species to distantly related taxa for use in comparative studies. PMID:24074279

Andrews, Robin M; Brandley, Matthew C; Greene, Virginia W

2013-09-01

316

Organization and operation of the marine ornamental fish and invertebrate export fishery in Puerto Rico.  

PubMed

This fishery was examined utilizing public records, stakeholder interviews, and operational site visits to describe the fishery for the Puerto Rico Coral Reef Advisory Committee as a first step toward development of policies for the effective management of these natural resources. The fishery is not large, including fewer than 20 licensed fishers operating primarily on the west end of the island. Only three operators export product, with the remaining fishers providing specimens to the exporters based upon customer orders. Most collection of coral reef species occurs over hard rubble zones mixed with relic reef structures and rock, or on the sides and frontal areas of active reefs. Other species are collected from among mangrove prop root zones, tidal flats, and seagrass beds. Collections are made using simple barrier and dip nets for fish and motile invertebrates such as shrimp. Invertebrates such as crabs, starfish, and sea cucumbers are commonly collected by overturning small rocks, gathering the specimens, and then replacing the rocks in their original positions. Specimens are carried to the boat and transferred to individual cup holders to maximize survival. Although statements concerning former use of chemicals to assist capture were noted, no evidence of current chemical use was observed. Specimens are held in re-circulating seawater systems onshore until collections are aggregated and shipped. The fishery strives to operate with mortality of<1%, as mortalities of>3% are described as unacceptable to customers. More than 100 fish species are collected in this fishery, but the top ten species account for >70% of the total numbers and >60% of the total value of the fishery, with a single species, Gramma loreto (Royal Gramma), comprising >40% of the numbers. More than 100 species of invertebrates are collected, but this fishery is also dominated by a handful of species, including anemones, hermit crabs, turbo snails, serpent starfish, and feather duster polychaetes. PMID:17465154

Legorel, Richard S; Hardin, Mark P; Ter-Ghazaryan, Diana

2005-05-01

317

Cross-Cultural Astronomy in Informal Education Settings - Collaboration with Integrity  

NASA Astrophysics Data System (ADS)

The richness of astronomical knowledge and traditions from diverse cultures can engage participants of all ages and backgrounds. We will present astronomy-focused programs for museums, planetariums, and community centers designed to enhance participation of underserved populations in celebrating the International Year of Astronomy (IYA) in 2009. We will share examples of how the indigenous astronomies from the Southwestern US and Mesoamerica can be juxtaposed with Western astronomy to enhance education efforts and understanding for all audiences. In these examples, the traditional knowledge has been highlighted and incorporated into the realm of innovative and unique multimedia resources that engage students and the public, and which often ignite a deeper and more authentic interest in western astronomy and astrophysics. We will discuss approaches to displaying the Navajo sky in a digital planetarium in a manner that is true to the Navajo worldview and that also presents images and information from Western astronomy. We will share multi-media resources that highlight the importance of solar alignments in architecture and in landscape within the context of the seasons. We will also discuss how we are exploring ways to protect the intellectual property rights of indigenous sky knowledge while making aspects of it available to the general public. Our collaboration upholds the integrity of both Western and Indigenous astronomy knowledge and research protocols, and honors indigenous languages. We will discuss collaborative and relationship-based evaluation strategies emerging from the above efforts and from a new effort, Cosmic Serpent, a professional development program to increase the capacity of museum practitioners to bridge indigenous and western science learning in informal settings. We will provide links and information to access products and programs to engage all audiences in the wonder, complexity, and beauty of our Universe. We acknowledge the generous support of NASA/SMD and NSF DRL/ISE.

Maryboy, Nancy; Hawkins, I.; Begay, D.; Sakimoto, P.

2008-05-01

318

High conversion Th-U{sup 233} fuel assembly for current generation of PWRs  

SciTech Connect

This paper presents a preliminary design of a high conversion Th-U{sup 233} fuel assembly applicable for current generation of Pressurized Water Reactor (PWRs). The considered fuel assembly has a typical 17 x 17 PWR lattice. However in order to increase the conversion of Th{sup 232} to U{sup 233}, the assembly was subdivided into the two regions called seed and blanket. The central seed region has a higher than blanket U{sup 233} content and acts as a neutron source for the peripheral blanket region. The latest acts as a U{sup 233} breeder. While the seed fuel pins have a standard dimensions the blanket fuel radius was increased in order to reduce the moderation and to facilitate the resonance neutron absorption in blanket Th{sup 232}. The U{sup 233} content in the seed and blanket regions was optimized to achieve maximal initial to discharged fissile inventory ratio (FIR) taking into account the target fuel cycle length of 12 months with 3-batch reloading scheme. In this study the neutronic calculations were performed on the fuel assembly level using Helios deterministic lattice transport code. The fuel cycle length and the core k{sub eff} were estimated by applying the Non Linear Reactivity Model. The applicability of the HELIOS code for the analysis of the Th-based high conversion designs was confirmed with the help of continuous-energy Monte-Carlo code SERPENT. The results of optimization studies show that for the heterogeneous seed and blanket (SB) fuel assembly the FIR of about 0.95 can be achieved. (authors)

Baldova, D.; Fridman, E. [Reactor Safety Div., Helmholtz-Zentrum Dresden-Rossendorf, POB 510119, Dresden, 01314 (Germany)

2012-07-01

319

Phylogeography of the Mekong mud snake (Enhydris subtaeniata): the biogeographic importance of dynamic river drainages and fluctuating sea levels for semiaquatic taxa in Indochina  

PubMed Central

During the Cenozoic, Southeast Asia was profoundly affected by plate tectonic events, dynamic river systems, fluctuating sea levels, shifting coastlines, and climatic variation, which have influenced the ecological and evolutionary trajectories of the Southeast Asian flora and fauna. We examined the role of these paleogeographic factors on shaping phylogeographic patterns focusing on a species of semiaquatic snake, Enhydris subtaeniata (Serpentes: Homalopsidae) using sequence data from three mitochondrial fragments (cytochrome b, ND4, and ATPase—2785 bp). We sampled E. subtaeniata from seven locations in three river drainage basins that encompassed most of this species’ range. Genetic diversities were typically low within locations but high across locations. Moreover, each location had a unique suite of haplotypes not shared among locations, and pairwise ?ST values (0.713–0.998) were highly significant between all location pairs. Relationships among phylogroups were well resolved and analysis of molecular variance (AMOVA) revealed strong geographical partitioning of genetic variance among the three river drainage basins surveyed. The genetic differences observed among the populations of E. subtaeniata were likely shaped by the Quaternary landscapes of Indochina and the Sunda Shelf. Historically, the middle and lower Mekong consisted of strongly dissected river valleys separated by low mountain ranges and much of the Sunda Shelf consisted of lowland river valleys that served to connect faunas associated with major regional rivers. It is thus likely that the contemporary genetic patterns observed among populations of E. subtaeniata are the result of their histories in a complex terrain that created abundant opportunities for genetic isolation and divergence yet also provided lowland connections across now drowned river valleys.

Lukoschek, Vimoksalehi; Osterhage, Jennifer L; Karns, Daryl R; Murphy, John C; Voris, Harold K

2011-01-01

320

Purification and characterization of islet hormones (insulin, glucagon, pancreatic, polypeptide and somatostatin) from the Burmese python, Python molurus.  

PubMed

Insulin was purified from an extract of the pancreas of the Burmese python, Python molurus (Squamata:Serpentes) and its primary structure established as: A Chain: Gly-Ile-Val-Glu-Gln-Cys-Cys-Glu-Asn-Thr10-Cys-Ser-Leu-Tyr-Glu-Leu- Glu-Asn-Tyr-Cys20-Asn. B-Chain: Ala-Pro-Asn-Gln-His-Leu-Cys-Gly-Ser-His10-Leu-Val-Glu-Ala-Leu-Tyr- Leu-Val-Cys-Gly20-Asp-Arg-Gly-Phe-Tyr-Tyr-Ser-Pro-Arg-Ser30. With the exception of the conservative substitution Phe --> Tyr at position B25, those residues in human insulin that comprise the receptor-binding and those residues involved in dimer and hexamer formation are fully conserved in python insulin. Python insulin was slightly more potent (1.8-fold) than human insulin in inhibiting the binding of [125I-Tyr-A14] insulin to the soluble full-length recombinant human insulin receptor but was slightly less potent (1.5-fold) than human insulin for inhibiting binding to the secreted extracellular domain of the receptor. The primary structure of python glucagon contains only one amino acid substitution (Ser28 --> Asn) compared with turtle/duck glucagon and python somatostatin is identical to that of mammalian somatostatin-14. In contrast, python pancreatic polypeptide (Arg-Ile-Ala-Pro-Val-Phe-Pro-Gly-Lys-Asp10-Glu-Leu-Ala-Lys-Phe- Tyr20-Thr-Glu-Leu-Gln-Gln-Tyr-Leu-Asn-Ser-Ile30-Asn-Arg-Pro-Arg -Phe.NH2) contains only 35 instead of the customary 36 residues and the amino acid sequence of this peptide has been poorly conserved between reptiles and birds (18 substitutions compared with alligator and 20 substitutions compared with chicken). PMID:9350978

Conlon, J M; Secor, S M; Adrian, T E; Mynarcik, D C; Whittaker, J

1997-08-29

321

Structural and functional characterization of a P-III metalloproteinase, leucurolysin-B, from Bothrops leucurus venom.  

PubMed

Leucurolysin-B (leuc-B) is an hemorrhagic metalloproteinase found in the venom of Bothrops leucurus (white-tailed-jararaca) snake. By means of liquid chromatography consisting of gel filtration on Sephracryl S-200, S-300 and ion-exchange on DEAE Sepharose, leuc-B was purified to homogeneity. The proteinase has an apparent molecular mass of 55kDa as revealed by the reduced SDS-PAGE, and represents approximately 1.2% of the total protein in B. leucurus venom. The partial amino acid sequence of leuc-B was determined by automated Edman sequencing of peptides derived from digests of the S-reduced and alkylated protein with trypsin. Leuc-B exhibits the characteristic motif of metalloproteinases, HEXXHXXGXXH and a methionine-containing turn of similar conformation ("Met-turn"), which forms a hydrophobic basis for the zinc ions and the three histidine residues involved as ligands. Leuc-B has been characterized as a P-III metalloproteinase and possesses a multidomain structure including a metalloproteinase, a disintegrin-like (ECD sequence instead of the typical RGD motif) and a cysteine-rich C-terminal domain. Leuc-B contains three potential sites of N-glycosylation. The enzyme only cleaves the Ala14-Leu15 peptide bond of the oxidized insulin B-chain and preferentially hydrolyzes the Aalpha-chain of fibrinogen and the alpha-chain of fibrin. Its proteolytic activity was completely inhibited by metal chelating agents but not by other typical proteinase inhibitors. In addition, its enzymatic activity was stimulated by the divalent cations Ca2+ and Mg2+ but inhibited by Zn2+ and Cu2+. The catalytic activity of leuc-B on extracellular matrix proteins could readily lead to loss of capillary integrity resulting in hemorrhage occurring at those sites (MHD=30ng in rabbit), with alterations in platelet function. In summary, here we report the isolation and the structure-function relationship of a P-III snake venom metalloproteinase. PMID:17963685

Sanchez, Eladio F; Gabriel, Lucilene M; Gontijo, Sileia; Gremski, Luiza H; Veiga, Silvio S; Evangelista, Karla S; Eble, Johannes A; Richardson, Michael

2007-10-12

322

Mass spectrophotometric evidence for P-III/P-IV metalloproteinases in the venom of the Boomslang (Dispholidus typus).  

PubMed

The Boomslang, Dispholidus typus, is a mid- to rear-fanged arboreal colubrid widely distributed throughout much of the African continent. Envenoming by this species is rare although deaths have been recorded. Typical symptoms associated with envenoming include diffuse intravascular coagulation (DIC) caused by fibrinogen consumption and consequent incoagulable blood together with haemorrhage into tissues such as muscle and brain; together, these procoagulant and haemorrhagic effects of the venom result in a very poor prognosis in patients who receive a large dose of venom and who are not treated with antivenom. Renal failure may also result from acute tubular necrosis resulting from pigment nephropathy. Little is known about the toxic components present in the venom; however, proteolytic activity has been reported although the proteinases involved have not been identified. In this study we provide LC/MS/MS (liquid chromatography/mass spectrometry/mass spectrometry) data supporting the presence of class P-III/P-IV snake venom metalloproteinases (SVMPs) in Boomslang venom. Using a polyclonal antibody raised against the P-III haemorrhagic toxin (Jararhagin) obtained from the venom of the Brazilian pit viper, Bothrops jararaca, we identified by western blot a 65 kDa protein from Boomslang venom which cross-reacted with the jararhagin antibody. A corresponding band from SDS-PAGE was subjected to tryptic digestion followed by LC/MS/MS sequence analysis of the digestion mixture. A variety of peptide sequences were identified in the digest, one of which was clearly homologous with a highly conserved region of the disintegrin-like domains of P-III/P-IV SVMPs. These data provide the first structural evidence for the presence of SVMPs in Boomslang venom; it is possible that SVMPs may also be present in the venoms of other colubrids, which cause similar symptoms in envenomed humans. In other snake venoms, most notably those of the Viperinae and Crotalinae subfamilies, many of the coagulopathic and haemorrhagic syndromes associated with systemic and local envenoming are attributed to SVMPs. The identification of a P-III/P-IV SVMP sequence in D. typus venom suggests that many of the pathological signs resulting from envenoming by this species may also be due to the presence of SVMPs in the venom. It is hoped that these results may accelerate research into colubrid venoms and may provide new insights into novel and more efficacious treatments for colubrid envenoming. PMID:10775761

Kamiguti, A S; Theakston, R D; Sherman, N; Fox, J W

2000-11-01

323

Evolution of CRISPs associated with toxicoferan-reptilian venom and mammalian reproduction.  

PubMed

Cysteine-rich secretory proteins (CRISPs) are glycoproteins found exclusively in vertebrates and have broad diversified functions. They are hypothesized to play important roles in mammalian reproduction and in reptilian venom, where they disrupt homeostasis of the prey through several mechanisms, including among others, blockage of cyclic nucleotide-gated and voltage-gated ion channels and inhibition of smooth muscle contraction. We evaluated the molecular evolution of CRISPs in toxicoferan reptiles at both nucleotide and protein levels relative to their nonvenomous mammalian homologs. We show that the evolution of CRISP gene in these reptiles is significantly influenced by positive selection and in snakes (? = 3.84) more than in lizards (? = 2.33), whereas mammalian CRISPs were under strong negative selection (CRISP1 = 0.55, CRISP2 = 0.40, and CRISP3 = 0.68). The use of ancestral sequence reconstruction, mapping of mutations on the three-dimensional structure, and detailed evaluation of selection pressures suggests that the toxicoferan CRISPs underwent accelerated evolution aided by strong positive selection and directional mutagenesis, whereas their mammalian homologs are constrained by negative selection. Gene and protein-level selection analyses identified 41 positively selected sites in snakes and 14 sites in lizards. Most of these sites are located on the molecular surface (nearly 76% in snakes and 79% in lizards), whereas the backbone of the protein retains a highly conserved structural scaffold. Nearly 46% of the positively selected sites occur in the cysteine-rich domain of the protein. This directional mutagenesis, where the hotspots of mutations are found on the molecular surface and functional domains of the protein, acts as a diversifying mechanism for the exquisite biological targeting of CRISPs in toxicoferan reptiles. Finally, our analyses suggest that the evolution of toxicoferan-CRISP venoms might have been influenced by the specific predatory mechanism employed by the organism. CRISPs in Elapidae, which mostly employ neurotoxins, have experienced less positive selection pressure (? = 2.86) compared with the "nonvenomous" colubrids (? = 4.10) that rely on grip and constriction to capture the prey, and the Viperidae, a lineage that mostly employs haemotoxins (? = 4.19). Relatively lower omega estimates in Anguimorph lizards (? = 2.33) than snakes (? = 3.84) suggests that lizards probably depend more on pace and powerful jaws for predation than venom. PMID:22319140

Sunagar, Kartik; Johnson, Warren E; O'Brien, Stephen J; Vasconcelos, Vítor; Antunes, Agostinho

2012-02-01

324

The crucial role of the MyD88 adaptor protein in the inflammatory response induced by Bothrops atrox venom.  

PubMed

Most snake accidents in North Brazil are attributed to Bothrops atrox, a snake species of the Viperidae family whose venom simultaneously induces local and systemic effects in the victims. The former are clinically more important than the latter, as they cause severe tissue lesions associated with strong inflammatory responses. Although several studies have shown that inflammatory mediators are produced in response to B. atrox venom (BaV), there is little information concerning the molecular pathways involved in innate immune system signaling. Myeloid differentiation factor 88 (MyD88) is an adaptor molecule responsible for transmitting intracellular signals from most toll-like receptors (TLRs) after they interact with pathogen-associated molecular patterns (PAMPs) or other stimuli such as endogenous damage-associated molecular patterns (DAMPs). The MyD88-dependent pathway leads to activation of transcription factors, which in turn induce synthesis of inflammatory mediators such as eicosanoids, cytokines and chemokines. The aim of this study was to investigate the involvement of MyD88 on the acute inflammatory response induced by BaV. Wild-type (WT) C57BL/6 mice and MyD88 knockout (MyD88(-/-)) mice were intraperitoneally injected with BaV. Compared to WT mice, MyD88(-/-) animals showed an impaired inflammatory response to BaV, with lower influx of polymorphonuclear and mononuclear cells to the peritoneal cavity. Furthermore, peritoneal leukocytes from BaV-injected MyD88(-/-) mice did not induce COX-2 or LTB4 protein expression and released low concentrations of PGE2. These mice also failed to produce Th1 and Th17 cytokines and CCL-2, but IL-10 levels were similar to those of BaV-injected WT mice. Our results indicate that MyD88 signaling is required for activation of the inflammatory response elicited by BaV, raising the possibility of developing new therapeutic targets to treat Bothrops sp. poisoning. PMID:23474268

Moreira, Vanessa; Teixeira, Catarina; Borges da Silva, Henrique; D'Império Lima, Maria Regina; Dos-Santos, Maria Cristina

2013-03-05

325

Changes in deep-water epibenthic megafaunal assemblages in relation to seabed slope on the Nigerian margin  

NASA Astrophysics Data System (ADS)

Local-scale habitat heterogeneity associated with changes in slope is a ubiquitous feature of bathyal continental margins. The response of deep-sea species to high habitat heterogeneity is poorly known and slope can be used as a proxy for many important ecological variables, such as current flow, sedimentation and substratum type. This study determines how slope angle effects megafaunal species density and diversity at the Usan field, offshore Nigeria, between 740 and 760 m depth. This deep-water area is increasingly exploited for hydrocarbons, yet lacking in baseline biological information. Replicated remotely operated vehicle video transect surveys were carried out using industry infrastructure (through the SERPENT Project) at a representative range of slopes (1°, 3°, 11° and 29°). Twenty-four species of benthic megafaunal invertebrate were found, numerically dominated by the echinoid Phormosoma placenta, and nine species of fish were observed. Megafaunal invertebrate deposit feeder density decreased significantly with increasing slope (density range 0.503-0.081 individuals m-2). Densities of megafaunal suspension feeders were very low except at the highest slope site (mean density 0.17 m-2). Overall species richness was greater on steeper slopes, although the richness of deposit feeders was not affected. Reduced labile organic matter in sediments on steeper slopes likely reduced deposit feeder densities, but increased current flow at higher slopes allowed both increased richness and density of suspension feeders. HighlightsQuantitative replicated video survey of benthic megafauna on Nigerian Margin.Assess the role of slope in controlling megafaunal assemblage structure in the deep sea.Clear relationship of reducing deposit feeder and increasing suspension feeder densities with slope.Dense, species rich assemblage found on hard substrata exposed on steep slopes.

Jones, Daniel O. B.; Mrabure, Charles O.; Gates, Andrew R.

2013-08-01

326

Deterministic Modeling of the High Temperature Test Reactor  

SciTech Connect

Idaho National Laboratory (INL) is tasked with the development of reactor physics analysis capability of the Next Generation Nuclear Power (NGNP) project. In order to examine INL’s current prismatic reactor deterministic analysis tools, the project is conducting a benchmark exercise based on modeling the High Temperature Test Reactor (HTTR). This exercise entails the development of a model for the initial criticality, a 19 column thin annular core, and the fully loaded core critical condition with 30 columns. Special emphasis is devoted to the annular core modeling, which shares more characteristics with the NGNP base design. The DRAGON code is used in this study because it offers significant ease and versatility in modeling prismatic designs. Despite some geometric limitations, the code performs quite well compared to other lattice physics codes. DRAGON can generate transport solutions via collision probability (CP), method of characteristics (MOC), and discrete ordinates (Sn). A fine group cross section library based on the SHEM 281 energy structure is used in the DRAGON calculations. HEXPEDITE is the hexagonal z full core solver used in this study and is based on the Green’s Function solution of the transverse integrated equations. In addition, two Monte Carlo (MC) based codes, MCNP5 and PSG2/SERPENT, provide benchmarking capability for the DRAGON and the nodal diffusion solver codes. The results from this study show a consistent bias of 2–3% for the core multiplication factor. This systematic error has also been observed in other HTTR benchmark efforts and is well documented in the literature. The ENDF/B VII graphite and U235 cross sections appear to be the main source of the error. The isothermal temperature coefficients calculated with the fully loaded core configuration agree well with other benchmark participants but are 40% higher than the experimental values. This discrepancy with the measurement stems from the fact that during the experiments the control rods were adjusted to maintain criticality, whereas in the model, the rod positions were fixed. In addition, this work includes a brief study of a cross section generation approach that seeks to decouple the domain in order to account for neighbor effects. This spectral interpenetration is a dominant effect in annular HTR physics. This analysis methodology should be further explored in order to reduce the error that is systematically propagated in the traditional generation of cross sections.

Ortensi, J.; Cogliati, J. J.; Pope, M. A.; Ferrer, R. M.; Ougouag, A. M.

2010-06-01

327

Application de la methode des sous-groupes au calcul Monte-Carlo multigroupe  

NASA Astrophysics Data System (ADS)

This thesis is dedicated to the development of a Monte Carlo neutron transport solver based on the subgroup (or multiband) method. In this formalism, cross sections for resonant isotopes are represented in the form of probability tables on the whole energy spectrum. This study is intended in order to test and validate this approach in lattice physics and criticality-safety applications. The probability table method seems promising since it introduces an alternative computational way between the legacy continuous-energy representation and the multigroup method. In the first case, the amount of data invoked in continuous-energy Monte Carlo calculations can be very important and tend to slow down the overall computational time. In addition, this model preserves the quality of the physical laws present in the ENDF format. Due to its cheap computational cost, the multigroup Monte Carlo way is usually at the basis of production codes in criticality-safety studies. However, the use of a multigroup representation of the cross sections implies a preliminary calculation to take into account self-shielding effects for resonant isotopes. This is generally performed by deterministic lattice codes relying on the collision probability method. Using cross-section probability tables on the whole energy range permits to directly take into account self-shielding effects and can be employed in both lattice physics and criticality-safety calculations. Several aspects have been thoroughly studied: (1) The consistent computation of probability tables with a energy grid comprising only 295 or 361 groups. The CALENDF moment approach conducted to probability tables suitable for a Monte Carlo code. (2) The combination of the probability table sampling for the energy variable with the delta-tracking rejection technique for the space variable, and its impact on the overall efficiency of the proposed Monte Carlo algorithm. (3) The derivation of a model for taking into account anisotropic effects of the scattering reaction consistent with the subgroup method. In this study, we generalize the Discrete Angle Technique, already proposed for homogeneous, multigroup cross sections, to isotopic cross sections on the form of probability tables. In this technique, the angular density is discretized into probability tables. Similarly to the cross-section case, a moment approach is used to compute the probability tables for the scattering cosine. (4) The introduction of a leakage model based on the B1 fundamental mode approximation. Unlike deterministic lattice packages, most Monte Carlo-based lattice physics codes do not include leakage models. However the generation of homogenized and condensed group constants (cross sections, diffusion coefficients) require the critical flux. This project has involved the development of a program into the DRAGON framework, written in Fortran 2003 and wrapped with a driver in C, the GANLIB 5. Choosing Fortran 2003 has permitted the use of some modern features, such as the definition of objects and methods, data encapsulation and polymorphism. The validation of the proposed code has been performed by comparison with other numerical methods: (1) The continuous-energy Monte Carlo method of the SERPENT code. (2) The Collision Probability (CP) method and the discrete ordinates (SN) method of the DRAGON lattice code. (3) The multigroup Monte Carlo code MORET, coupled with the DRAGON code. Benchmarks used in this work are representative of some industrial configurations encountered in reactor and criticality-safety calculations: (1)Pressurized Water Reactors (PWR) cells and assemblies. (2) Canada-Deuterium Uranium Reactors (CANDU-6) clusters. (3) Critical experiments from the ICSBEP handbook (International Criticality Safety Benchmark Evaluation Program).

Martin, Nicolas

328

How to Steal a Million Stars?  

NASA Astrophysics Data System (ADS)

Based on observations with ESO's Very Large Telescope, a team of Italian astronomers reports [1] that the stellar cluster Messier 12 must have lost to our Milky Way galaxy close to one million low-mass stars. ESO PR Photo 04a/06 ESO PR Photo 04a/06 The Central Part of Messier 12 "In the solar neighbourhood and in most stellar clusters, the least massive stars are the most common, and by far", said Guido De Marchi (ESA), lead author of the study. "Our observations with ESO's VLT show this is not the case for Messier 12." The team, which also includes Luigi Pulone and Francesco Paresce (INAF, Italy), measured the brightness and colours of more than 16,000 stars within the globular cluster Messier 12 [2] with the FORS1 multi-mode instrument attached to one of the Unit Telescopes of ESO's VLT at Cerro Paranal (Chile). The astronomers could study stars that are 40 million times fainter than what the unaided eye can see (magnitude 25). Located at a distance of 23,000 light years in the constellation Ophiuchus (The Serpent-holder), Messier 12 got its name by being the 12th entry in the catalogue of nebulous objects compiled in 1774 by French astronomer and comet chaser Charles Messier. It is also known to astronomers as NGC 6218 and contains about 200,000 stars, most of them having a mass between 20 and 80 percent of the mass of the Sun. "It is however clear that Messier 12 is surprisingly devoid of low-mass stars", said De Marchi. "For each solar-like star, we would expect roughly four times as many stars with half that mass. Our VLT observations only show an equal number of stars of different masses." ESO PR Photo 04b/06 ESO PR Photo 04b/06 Loosing Stars in the Milky Way Globular clusters move in extended elliptical orbits that periodically take them through the densely populated regions of our Galaxy, the plane, then high above and below, in the 'halo'. When venturing too close to the innermost and denser regions of the Milky Way, the 'bulge', a globular cluster can be perturbed, the smallest stars being ripped away. "We estimate that Messier 12 lost four times as many stars as it still has", said Francesco Paresce. "That is, roughly one million stars must have been ejected into the halo of our Milky Way." The total remaining lifetime of Messier 12 is predicted to be about 4.5 billion years, i.e. about a third of its present age. This is very short compared to the typical expected globular cluster's lifetime, which is about 20 billion years. The same team of astronomers had found in 1999, another example of a globular cluster that lost a large fraction of its original content (see ESO PR 04/99). The scientists hope to discover and study many more clusters like these, since catching clusters while being disrupted should clarify the dynamics of the process that shaped the halo of our home galaxy, the Milky Way. High resolution images and their captions are available on this page. A press release on this is also issued by INAF in Italian and is available at www.inaf.it/comunicati_stampa/cs070206/Inaf-04-06.html.

2006-02-01

329

Broken formations, melanges and olistostromes in Puerto Plata area (Northern Dominican Republic) as a record of subduction and collisional processes between the Caribbean and North-American plates  

NASA Astrophysics Data System (ADS)

The Northern Cordillera of the Dominican Republic records the (oblique) subduction and collisional processes occurred between the Caribbean and North-American plates during Upper Cretaceous to Lower Paleogene times. The boundary between these two plates can be traced within this range disrupted by an Upper Paleogene to present intense left-lateral strike-slip tectonism, onset after collision. In the western part of the range this boundary might be defined by the Camu fault. In the coastal area of Puerto Plata, located on the northern block of the Camu fault, basement rocks belonging to the subducting plate (the Puerto Plata Basement Complex) and several related units probably formed in an accretionary prism, preserve in a large (300 km2) outcrop of chaotic formations presumably formed (and exhumed) during collision. They include from broken formations and tectonic melanges to olistostromes and other coeval sedimentary deposits. The Puerto Plata Basement Complex (PPBC) consists of highly faulted and dismembered blocks formed by discontinuous but sometimes coherent outcrops of serpentinized or massive peridotite, pods of ultramafic cumulates, massive or banded gabbros and Los Caños Fm, a thick sequence of gross bedded volcaniclastic material with interbedded basaltic (sometimes pillowed) or andesitic flows. All these rocks bear low grade metamorphism and lack a general deformation fabric apart from occasional transformation to mylonites due to localized shearing. The PPBC has been interpreted as a fragment of oceanic crust, belonging to the subducting (North-American) slab that has been exhumed as a tectonic melange or a broken complex. The Imbert Fm, of Palaeocene-Eocene age, is formed by a well bedded succession of white very fine grained porcelaneous tuffs, with eventual intercalations of cherts, limestones and marls that, towards the lower part, is interbedded with volcanic-derived graywackes and limolites, and more occasionally, thick beds of conglomerates and debris. These last ones typically incorporate fragments of serpentized peridotites and blocks of the volcanic rocks identified in the PPBC. The Imbert Fm is also internally disrupted and although not a single clear contact can be observed in the field, it is considered to rest unconformably over the complex, so postdating its exhumation. A separate mappable unit of serpentinitic brecchias has recently been identified mainly distributed along the outer limits of the PPBC but also in several scattered outcrops inside it. The unit is dominantly made of fragments and blocks of serpentinized peridotites, embedded in an abundant matrix of the same composition and includes also blocks of Los Caños and Imbert Fm, as well as other exotic blocks of unknown origin. In the southeastern limit of the complex, close to the Camu fault, there is a particular high concentration of exotic blocks derived from metamorphic rocks (greenschists, anfibolites, marbles and even blueschists) not exposed in any neighbouring areas and thus suggesting a deep-sited, subduction-related, feeding. The basal contact of this unit with the rocks of the PPBC is usually faulted and difficult to observe in the field, but cartographic patterns suggest that it is an unconformity. Outcrops of serpentinitic breccias show a wide variety of internal chaotic organization, from pods of tectonic melanges to the most frequent block-in matrix fabric, but most of them also show evidences of sedimentary rework. In the easternmost part of the PPBC, the serpentinitic brecchias are, in turn, the base of an olistostromic complex widely represented in the region, the San Marcos Fm. The olistostrome includes similar exotic blocks than observed in the serpentinitic brecchias and blocks and olistolithes derived from the PPBC but, mainly, from the Imbert Fm. According to the described relationships, the serpentinitic breccias and San Marcos olistostrome are considered partially coeval and laterally equivalent to the Imbert Fm.

Hernaiz Huerta, Pedro Pablo; Valera Fernando, Pérez; de Los Santos Manuel, Abad; Jacques, Monthel; de Neira Alberto, Díaz

2010-05-01

330

A Vanishing Star Revisited  

NASA Astrophysics Data System (ADS)

VLT Observations of an Unusual Stellar System Reinhold Häfner of the Munich University Observatory (Germany) is a happy astronomer. In 1988, when he was working at a telescope at the ESO La Silla observatory, he came across a strange star that suddenly vanished off the computer screen. He had to wait for more than a decade to get the full explanation of this unusual event. On June 10-11, 1999, he observed the same star with the first VLT 8.2-m Unit Telescope (ANTU) and the FORS1 astronomical instrument at Paranal [1]. With the vast power of this new research facility, he was now able to determine the physical properties of a very strange stellar system in which two planet-size stars orbit each other. One is an exceedingly hot white dwarf star , weighing half as much as the Sun, but only twice as big as the Earth. The other is a much cooler and less massive red dwarf star , one-and-a-half times the size of planet Jupiter. Once every three hours, the hot star disappears behind the other, as seen from the Earth. For a few minutes, the brightness of the system drops by a factor of more than 250 and it "vanishes" from view in telescopes smaller than the VLT. A variable star named NN Serpentis ESO PR Photo 30a/99 ESO PR Photo 30a/99 [Preview - JPEG: 400 x 468 pix - 152k] [Normal - JPEG: 800 x 936 pix - 576k] [High-Res - JPEG: 2304 x 2695 pix - 4.4M] Caption to ESO PR Photo 30a/99 : The sky field around the 17-mag variable stellar system NN Serpentis , as seen in a 5 sec exposure through a V(isual) filter with VLT ANTU and FORS1. It was obtained just before the observation of an eclipse of this unsual object and served to centre the telescope on the corresponding sky position. The field shown here measures 4.5 x 4.5 armin 2 (1365 x 1365 pix 2 ; 0.20 arcsec/pix). The field is somewhat larger than that shown in Photo 30b/99 and has the same orientation to allow comparison: North is about 20° anticlockwise from the top and East is 90° clockwise from that direction. The unsual star in question is designated NN Serpentis , or just NN Ser . As the name indicates, it is located in the constellation of Serpens (The Serpent), about 12° north of the celestial equator. A double letter, here "NN", is used to denote variable stars [2]. It is a rather faint object of magnitude 17, about 25,000 times fainter than what can be perceived with the unaided eye. The distance is about 600 light-years (180 pc). In July 1988, Reinhold Häfner performed observations of NN Ser (at that time still known by its earlier name PG 1550+131 ) with the Danish 1.54-m telescope at La Silla. He was surprised, but also very pleased to discover that it underwent a very deep eclipse every 187 minutes. Within less than 2 minutes, the brightness dropped by a factor of more than 100 (5 magnitudes). During the next 9 minutes, the star completely disappeared from view - it was too faint to be observed with this telescope. It then again reappeared and the entire event was over after just 11 minutes. Why eclipses are so important for stellar studies An eclipse occurs when one of the stars in a binary stellar system moves in front of the other, as seen by the observer. The effect is similar to what happens during a solar eclipse when the Moon moves in front of the Sun. In both cases, the eclipse may be partial or total , depending on whether or not the eclipsed star (or the Sun) is completely hidden from view. The occurence of eclipses in stellar systems, as seen from the Earth, depends on the spatial orientation of the orbital plane and the sizes of the two stars. Two eclipses take place during one orbital revolution, but they may not both be observable. The physical properties of the two stars in a binary system (e.g., the sizes of the stars, the size and shape of the orbit, the distribution of the light on the surfaces of the stars, their temperatures etc.) can be determined from the measured "light-curve" of the system (a plot of brightness vrs. time). The stars are always too close to each other to be seen as anything but a point of lig

1999-07-01