oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Rabbit antivenom efficacy against myotoxic and neurotoxic activities of Bothrops jararacussu venom and bothropstoxin-I
Oshima-Franco, Y.;Leite, G. B.;Valério, A. A.;Hyslop, S.;Andriao-Escarso, S.;Giglio, J. R.;Prado-Franceschi, J.;Cruz-H?fling, M. A.;Rodrigues-Simioni, L.;
Journal of Venomous Animals and Toxins , 2002, DOI: 10.1590/S0104-79302002000200004
Abstract: bothrops jararacussu venom and its major toxin bothropstoxin-i (bthtx-i) possess myotoxic and neurotoxic properties. the efficacy of a rabbit antivenom raised against b. jararacussu venom in the neutralization of physiological, biochemical, and morphological changes induced by the venom and its major toxin bthtx-i was studied in mouse isolated phrenic nerve-diaphragm (pnd) and extensor digitorum longus (edl) preparations. the times required for 50% neuromuscular blockade in pnd and edl preparations for venom were 70+11.5 (s.e.m., n=5) min and 58+8 (n=16) (50 m g/ml), and for bthtx-i 31+6 (n=3) min and 30+3 (n=5) min (20 m g/ml), respectively. after 120 min incubation, creatine kinase (ck) concentrations in solution containing the edl preparations were 3464+346 u/l after exposure to venom (50 m g/ml, n=5) and 3422+135 u/l to bthtx-i (20m g/ml, n=4), respectively. rabbit antivenom dose-dependently neutralized venom and toxin-induced neuromuscular blockade in both preparations and effectively prevented venom and toxin-induced ck release from edl. histological analysis showed that rabbit antivenom neutralized morphological damage caused by b. jararacussu venom and bthtx-i in edl preparations. these results indicate that rabbit antivenom effectively neutralized the biological activities of b. jararacussu venom and bthtx-i.
Cross-neutralization of the coagulant activity of Crotalus durissus terrificus venom from the northeast of Argentina by bivalent bothropic antivenom
Rodríguez, JP;Gay, CC;Fusco, LS;Gauna, MC;Acosta, OC;Leiva, LC;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2012, DOI: 10.1590/S1678-91992012000100015
Abstract: cross-neutralization of crotalus durissus terrificus venom coagulant activity was tested using bivalent horse antivenom against bothrops alternatus and bothrops diporus venoms. our in vitro and in vivo experiments showed that bothropic antivenom neutralizes the thrombin-like activity of crotalic snake venom and this cross-reaction was demonstrated by immunoassays either with whole venom or a purified thrombin-like enzyme. these results suggest common antigenic properties and, consequently, similar molecular structure among venom thrombin-like enzymes. besides, they provide information that could be further used in the development of new antivenom formulations.
Acción del veneno de Bothrops jararacussu de Argentina sobre la coagulación sanguínea
Maru?ak,S.L.; Ruíz de Torrent,R.M.; Teibler,G.P.; Gay,C.C.; Leiva,L.; Acosta de Pérez,O.;
InVet , 2006,
Abstract: the envenomation by snakes of the genus bothrops of argentina causes local and systemic signs. among the systemic damages, bothropic venoms induce a wide variety of effects on blood coagulation, haemorrhage, shock and renal failure. in this paper the effects of bothrops jararacussu venom from argentina on the hemostatic system were determined. in order to estimate blood-clotting, fibrinolytic and defibrinating activities of the venom, in vitro and in vivo tests were employed. the ability to degrade fibrinogen and the lethal dosis (dl50) also were determined. the b. jararacussu venom appears to be fibrinogenolytic and the values obtained for assayed activities were minimum blood-clotting concentration 18,5 μg/ml, minimum fibrinolytic dose 9,5 mg/ml, minimum defibrinating dose 1,56 μg, ld50 43,52 μg/mouse. these results differ from those obtained for other species of genus bothrops, or from the same species that inhabits in different south american regions. it is concluded that bothrops jararacussu venom from argentina largely affects blood coagulation system, and that the procoagulant and anticoagulant activities exhibited by this secretion may contribute to the lethality of the venom, since they could promote hemorrhages which could lead to renal failure and death of the victim in severe envenomation.
A eficácia do antiveneno botrópico-crotálico na neutraliza??o das principais atividades do veneno de Bothrops jararacussu
dos-Santos, Maria Cristina;Gon?alves, Luís Roberto de Camargo;Fortes-Dias, Consuelo L.;Cury, Yara;Gutiérrez, José Maria;Furtado, Maria de Fátima D.;
Revista do Instituto de Medicina Tropical de S?o Paulo , 1992, DOI: 10.1590/S0036-46651992000200001
Abstract: myonecrosis is one of the effects of bothrops jararacussu venom, from which a myotoxin was isolated showing structural homology to phospholipase a2 (pla2), but without enzimatic activity. such myotoxic activity is also present in the crotalus durissus terrificus venom, and is atributed to crotoxin and to pla2 (crotoxin b), the basic component of the crotoxin complex. the bothrops jararacussu venom showed three proteins with immunologic identity to pla2 from crotoxin. the bothropic (ab) and the bothropic/crotalic (ab/c) antivenoms, two commercial polyvalent antivenoms produced at instituto butantan, were compared in order to assess their capacity for neutralization of the lethal, hemorrhagic, coagulant and myotoxic activities of bothrops jararacussu venom. both antivenoms showed the same level of hemorrhagic activity neutralization. however, ab/c was about three times more efficient than ab in neutralizing the myotoxic activity, and two times more potent for neutralization of lethality and coagulant activity of bothrops jararacussu venom. these data suggest that the use of ab/c could be of value in the treatment of patients bitten by snakes of this species
Acción del veneno de Bothrops jararacussu de Argentina sobre la coagulación sanguínea Activity of the venom of Bothrops jararacussu of Argentina on blood coagulation  [cached]
S.L. Maru?ak,R.M. Ruíz de Torrent,G.P. Teibler,C.C. Gay
InVet , 2006,
Abstract: La intoxicación por mordeduras de serpientes del género Bothrops (yarará) de Argentina se caracteriza por causar efectos locales y sistémicos. Entre los sistémicos pueden generar alteraciones en la coagulación de la sangre, hemorragias, shock, insuficiencia renal. En este trabajo se estudiaron los efectos que causa el veneno de Bothrops jararacussu de Misiones, Argentina, sobre la coagulación de la sangre. Se utilizaron métodos in vitro e in vivo para evaluar la actividad coagulante, fibrinolítica y defibrinante, como así también la capacidad de degradar el fibrinógeno y la letalidad del veneno. El veneno mostró ser α-fibrinogenolítico y los resultados para las actividades ensayadas fueron: concentración coagulante mínima (CCM) 18,5 μg/ml, concentración fibrinolítica mínima (CFM) 9,5 mg/ml, dosis defibrinante mínima (DDM) 1,56 μg, DL50 43,52 μg/ratón, los que difieren de los obtenidos para otras especies de Bothrops e incluso dentro de la misma especie, pero distribuídas en otras regiones sudamericanas. Se concluye que el veneno de B. jararacussu de Argentina afecta marcadamente el sistema hemostático, y que las actividades coagulantes y anticoagulantes exhibidas por esta secreción probablemente influyan en la letalidad del veneno, dado que contribuirían a la aparición de hemorragias que, de ser severas, conducen a fallo renal y muerte de la víctima. The envenomation by snakes of the genus Bothrops of Argentina causes local and systemic signs. Among the systemic damages, bothropic venoms induce a wide variety of effects on blood coagulation, haemorrhage, shock and renal failure. In this paper the effects of Bothrops jararacussu venom from Argentina on the hemostatic system were determined. In order to estimate blood-clotting, fibrinolytic and defibrinating activities of the venom, in vitro and in vivo tests were employed. The ability to degrade fibrinogen and the lethal dosis (DL50) also were determined. The B. jararacussu venom appears to be fibrinogenolytic and the values obtained for assayed activities were minimum blood-clotting concentration 18,5 μg/ml, minimum fibrinolytic dose 9,5 mg/ml, minimum defibrinating dose 1,56 μg, LD50 43,52 μg/mouse. These results differ from those obtained for other species of genus Bothrops, or from the same species that inhabits in different South American regions. It is concluded that Bothrops jararacussu venom from Argentina largely affects blood coagulation system, and that the procoagulant and anticoagulant activities exhibited by this secretion may contribute to the lethality of the venom, since they could promo
Pulsed ultrasound therapy accelerates the recovery of skeletal muscle damage induced by Bothrops jararacussu venom
Saturnino-Oliveira, J.;Tomaz, M.A.;Fonseca, T.F.;Gaban, G.A.;Monteiro-Machado, M.;Strauch, M.A.;Cons, B.L.;Calil-Elias, S.;Martinez, A.M.B.;Melo, P.A.;
Brazilian Journal of Medical and Biological Research , 2012, DOI: 10.1590/S0100-879X2012007500033
Abstract: we studied the effect of pulsed ultrasound therapy (ust) and antibothropic polyvalent antivenom (pav) on the regeneration of mouse extensor digitorum longus muscle following damage by bothrops jararacussu venom. animals (swiss male and female mice weighing 25.0 ± 5.0 g; 5 animals per group) received a perimuscular injection of venom (1 mg/kg) and treatment with ust was started 1 h later (1 min/day, 3 mhz, 0.3 w/cm2, pulsed mode). three and 28 days after injection, muscles were dissected and processed for light microscopy. the venom caused complete degeneration of muscle fibers. ust alone and combined with pav (1.0 ml/kg) partially protected these fibers, whereas muscles receiving no treatment showed disorganized fascicules and fibers with reduced diameter. treatment with ust and pav decreased the effects of the venom on creatine kinase content and motor activity (approximately 75 and 48%, respectively). sonication of the venom solution immediately before application decreased the in vivo and ex vivo myotoxic activities (approximately 60 and 50%, respectively). the present data show that ust counteracts some effects of b. jararacussu venom, causing structural and functional improvement of the regenerated muscle after venom injury.
Neutralization of pharmacological and toxic activities of Bothrops jararacussu snake venom and isolated myotoxins by Serjania erecta methanolic extract and its fractions
Fernandes, RS;Costa, TR;Marcussi, S;Bernardes, CP;Menaldo, DL;Rodriguéz Gonzaléz, II;Pereira, PS;Soares, AM;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2011, DOI: 10.1590/S1678-91992011000100011
Abstract: most of the snakebites recorded in brazil are caused by the bothrops genus. given that the local tissue damage caused by this genus cannot be treated by antivenom therapy, numerous studies are focusing on supplementary alternatives, such as the use of medicinal plants. serjania erecta has already demonstrated anti-inflammatory, antiseptic and healing properties. in the current study, the aerial parts of s. erecta were extracted with methanol, then submitted to chromatographic fractionation on a sephadex lh20 column and eluted with methanol, which resulted in four main fractions. the crude extract and fractions neutralized the toxic activities of bothrops jararacussu snake venom and isolated myotoxins (bthtx-i and ii). results showed that phospholipase a2, fibrinogenolytic, myotoxic and hemorrhagic activities were inhibited by the extract. moreover, the myotoxic and edematous activities induced by bthtx-i, and phospholipase a2 activity induced by bthtx-ii, were inhibited by the extract of s. erecta and its fraction. the clotting time on bovine plasma was significantly prolonged by the inhibitory action of fractions sf3 and sf4. this extract is a promising source of natural inhibitors, such as flavonoids and tannins, which act by forming complexes with metal ions and proteins, inhibiting the action of serineproteases, metalloproteases and phospholipases a2.
THE IMMUNOCHEMICAL REACTIVITY AND NEUTRALIZING CAPACITY OF POLYVALENT Vipera (EUROPEAN) ANTIVENOM ON ENZYMATIC AND TOXIC ACTIVITIES IN THE VENOMS OF CROTALIDS FROM ARGENTINA
ROODT, A.R. de;DOLAB, J. A.;SEGRE, L.;SIMONCINI, C.;HAJOS, S. E.;FERNANDEZ, T.;DOKMETJIAN, J. C.;LITWIN, S.;ACCATTOLI, C.;VIDAL, J. C.;
Journal of Venomous Animals and Toxins , 1999, DOI: 10.1590/S0104-79301999000100006
Abstract: the immunochemical reactivity and neutralizing capacity of polyvalent vipera antivenom (vipera ammodytes, vipera aspis, vipera berus, vipera lebetina, and vipera xanthina) were tested on the enzymatic and biological activities of crotalus durissus terrificus and the following bothrops venoms from argentina (bothrops alternatus, bothrops ammodytoides, bothrops neuwiedii, bothrops jararaca, bothrops jararacussu, and bothrops moojeni). the vipera antivenom reacted weakly when tested by double immunoprecipitation (dip) and reacted with all the venoms when tested by elisa. several components in all the venoms studied were recognized in western blots. vipera antivenom deactivated to different degrees in vitro procoagulant, (indirect) hemolytic, and proteolytic activities in all the venoms studied. preincubation of bothrops alternatus venom with vipera antivenom neutralized a lethal potency of 4.5 ld50 in mice with an ed50 of 1.25 ± 0.25 ml per mg of venom, and with 1.0 ml/mg inhibited 54% of the hemorragic activity and 48% of necrotic activity. vipera antivenom (2.0 ml per mg toxin) inhibited the phospholipase a2 activity of purified crotoxin and decreased its lethal potency by 60%, while the neutralizing capacity on the lethal potency of crude crotalus durissus terrificus venom was poor even at a level of 5.0 ml/mg of venom.
Isolation and biological characterization of a basic phospholipase A2 from Bothrops jararacussu snake venom
Maru?ak,S.L.; Leiva,L; Garcia Denegri,M.E.; Teibler,P; Acosta De Pérez,O;
Biocell , 2007,
Abstract: a phospholipase a2 has been isolated from bothrops jararacussu venom from snakes that inhabit the northeast region of argentina. the present study describes in vivo and in vitro biological activities of phospholipase a2 from b. jararacussu as well as isolation details of its. venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20-30oc) rooms. snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. the enzyme was purified by gel filtration on a sephadex g-75 column followed by ion exchange chromatography on a sp-sephadex c25 column. the major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of kcl that exhibited phospholipase activity. this basic pla2 consists of a single polypeptide chain with a molecular mass of 15.6 kda. it had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. the enzyme showed a low lethality (ld50 148.6 mg) when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma ck activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of ck level just after 1 hour mice injection. moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase a2. these findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. however, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.
Isolation and biological characterization of a basic phospholipase A2 from Bothrops jararacussu snake venom  [cached]
S.L. Maru?ak,L Leiva,M.E. Garcia Denegri,P Teibler
Biocell , 2007,
Abstract: A phospholipase A2 has been isolated from Bothrops jararacussu venom from snakes that inhabit the northeast region of Argentina. The present study describes in vivo and in vitro biological activities of phospholipase A2 from B. jararacussu as well as isolation details of its. Venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20-30oC) rooms. Snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. The enzyme was purified by gel filtration on a Sephadex G-75 column followed by ion exchange chromatography on a SP-Sephadex C25 column. The major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of KCl that exhibited phospholipase activity. This basic PLA2 consists of a single polypeptide chain with a molecular mass of 15.6 kDa. It had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. The enzyme showed a low lethality (LD50 148.6 mg) when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma CK activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. Myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of CK level just after 1 hour mice injection. Moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase A2. These findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. However, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.