SEARCH · PubMed Health

Results for “Bothrops”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed2002

Complications of Bothrops, Porthidium, and Bothriechis snakebites in Colombia. A clinical and epidemiological study of 39 cases attended in a university hospital.

The clinical and epidemiological features, as well as complications presented by 39 patients with Bothrops, Porthidium and Bothriechis snakebites, are described. Patients were admitted during 1 year in 25 hospitals of Antioquia and Chocó and then, they were transferred to the Hospital Universitario San Vicente de Paúl in Medellín, 30 of them because of the presence of complications, eight because of lack of antivenoms and another one because of the desire of his relatives. Thirty--one (79.5%) of the patients were male, 13 (33.3%) children, 59% of them were bitten at the lower extremities, the majority (74.4%) by Bothrops asper. Twenty-one (53.8%) of the patients were initially attended by traditional healers and sought medical attention at the local hospitals after 2h in 87.2% of the cases. Edema (100%), hemorrhage (74.4%), blistering (38.5%) and necrosis (38.5%), were the local signs of envenomation, while blood coagulation alteration (79.5%), hematuria (74.4%), gingival bleeding (43.6%), hypovolemic shock (23.1%) and oliguria (23.1%), were the systemic signs of envenomation. The final grade of envenomation was severe in 29 patients (74.4%). Thirty patients (76.9%) had one or more complications of the envenomation: acute renal failure (ARF), 15 (38.5%); soft-tissue infection, 12 (30.8%); central nervous system (CNS) hemorrhage, 5 (12.8%); compartment syndrome, 3 (7.7%); soft--tissue hematomas, 6 (15.4%); and Abruptio placentae, one (2.6%). There were four deaths (10.3%), two from ARF and two from cerebral hemorrhage. Fourteen other patients (35.9%) had sequelae. The onset of serotherapy after 2h of the bite was associated with the occurrence of ARF and CNS hemorrhage (p=0.02), as well as the risk of death and sequelae (RR=2.5).

Adolescent↗

PubMed2003

Hemorrhagic activity of Bothrops venoms determined by two different methods and relationship with proteolytic activity on gelatin and lethality.

The changes in hemorrhagic activity, proteolytic activity on gelatin and the lethal potency of four Bothrops venoms treated at different pH values or with EDTA were studied. Venoms from B. alternatus, B. jararaca, B. moojeni and B. neuwiedii of Argentina were preincubated at pH 5.8, 5.1 or 3.8 or with EDTA and the hemorrhagic activity expressed as size of the hemorrhagic lesion or as the amount of hemoglobin extracted, the proteolytic activity on gelatin and the lethal potency were determined. Although the MHDs recorded in rats were 19-56 fold higher than those recorded in mice, the A(550) extracted per gram of hemorrhagic haloes was very similar in rats or mice independent of the venom dose. Inhibition of proteolytic activity after preincubation at pH 5.1 or 3.8, agrees with the decreased amount of hemoglobin extracted from the hemorrhagic haloes, and with the increase in mean survival time after the i.p. injection to mice. Preincubation with EDTA resulted in 80% inhibition of hemorrhagic activity of B. jararaca venom and complete inhibition with the other Bothrops venoms tested. Measurement of the amount of hemoglobin extracted gives significant information in comparative studies, not available by measurement of the size of hemorrhagic haloes.

Animals↗

PubMed1997

Neutralization of bothropic and crotalic venom toxic activities by IgG(T) and IgGa subclasses isolated from immune horse serum.

IgG(T) and IgGa isotypes were isolated from horse hyperimmune anti-bothropic and anti-crotalic sera using a combination of two affinity chromatographic processes. IgG(T) and IgGa isotypes were isolated from these sera by chromatography on protein A-Sepharose followed by separation of the two isotypes by chromatography on a column of anti-IgG(T)-Sepharose. LO-HoGT-1, a rat anti-horse IgG(T) monoclonal antibody, was used. A comparative study of the efficiency of these isotypes in neutralizing the main toxic activities of the homologous venoms was carried out. It was found that IgG(T) was about three-fold and seven-fold more protective than IgGa for neutralization of the lethal activity of B. jararaca and C. d. terrificus venoms, respectively. IgG(T) was also more effective than IgGa for the neutralization of the haemorrhagic activity induced by B. jararaca venom, while both isotypes neutralized equally well the blood incoagulability induced by this venom. The results suggest that IgG(T) is the most protective isotype present in both anti-bothropic and anti-crotalic sera, followed by IgGa. Owing to their very low concentration in the serum, other IgG isotypes are not likely to be important in neutralizing the venoms' toxic activities.

Animals↗

PubMed1998

[Hemorrhagic and edema-forming activity and histologic changes in the mouse footpad induced by venoms from Argentinian Bothrops and Crotalus genuses].

Hemorrhagic, oedema-forming activities and histopathological alterations in the mouse footpad induced by Bothrops and Crotalus snake venoms from Argentina. Hemorrhagic and oedema-forming activities of various Bothrops and Crotalus snake venoms from Argentina were studied, together with histological alterations in the mouse footpad. The highest oedema-forming activity was found in the venom of B. jararaca, followed by B. jararacussu, B. neuwiedii diporus, B. alternatus, and Crotalus durissus terrificus. Regarding hemorrhage, the highest activity was found in the venom of B. neuwiedii diporus, followed by B. jararacussu, B. alternatus, and B. jararaca. No hemorrhage was observed after injection of Crotalus durissus terrificus venom, in agreement with histological observations of injected footpads. Histological analysis revealed a conspicuous inflammatory reaction in the injected footpad, characterized by oedema and an inflammatory infiltrate rich in polymorphonuclear leucocytes. Necrotic blood vessels and dilated lymphatic vessels were observed after injection of B. jararaca and B. jararacussu venoms, and myonecrosis was evident in tissue of mice injected with B. alternatus and B. neuwiedii diporus.

Animals↗

PubMed1999

Detection of an antibothropic fraction in opossum (Didelphis marsupialis) milk that neutralizes Bothrops jararaca venom.

An antibothropic fraction (ABF) from Didelphis marsupialis (opossum) serum, which is responsible for the neutralization of Bothrops jararaca venom was isolated by Perales et al. [Perales, J., Moussatché, H., Marangoni, S., Oliveira, B. and Domont, G. B. (1994). Isolation and partial characterization of an antibothropic complex from the serum of South American Didelphidae. Toxicon 32, 1237-1249]. The aim of this work was to verify the presence of this factor in opossum's milk, which could represent an additional protection for the neonatal opossum against bothropic venoms. An active milk fraction was isolated and showed similar physicochemical, structural, antigenic and biological properties when compared to ABF, indicating that they are probably the same protein.

Animals↗

PubMed1999

Structure of a Lys49-phospholipase A2 homologue isolated from the venom of Bothrops nummifer (jumping viper).

Lys49-Phospholipase A2 (Lys49-PLA2) homologues damage membranes by a Ca2+-independent mechanism which does not involve catalytic activity. We have solved the structure of myotoxin-I, a Lys49-PLA2 homologue isolated from the venom of Bothrops nummifer (jumping viper) at 2.4 A resolution using molecular replacement techniques. The final model has been refined to a final R-factor of 18.4% (R-free = 23.2%), and shows excellent geometry. The myotoxin-I from Bothrops nummifer is dimeric in the crystalline state as has been observed for other Lys49-PLA2 homologues. In addition, a continuous electron density in the active site and substrate binding channel could be successfully modeled as a fatty-acid molecule.

Animals↗

PubMed2000

Neutralization of the hemorrhagic activity of Bothrops and Lachesis snake venoms by a monoclonal antibody against mutalysin-II.

One mAb reactive with mutalysin-II, a hemorrhagic metalloproteinase isolated from Lachesis muta muta venom, was produced in mice immunized with L. m. muta venom. Indirect ELISA was employed to compare the antigenic cross-reactivity among the venoms from Bothrops snakes. The mAb anti-mutalysin-II efficiently neutralized the hemorrhagic effect of both mutalysin-II and L. m. muta crude venom. Furthermore, the mAb were cross-reactive with B. alternatus, B. atrox, B. itapetiningae, B. jararaca and B. neuwiedii and showed variable potencies in neutralizing the hemorrhagic activity of several bothropic venoms.

Animals↗

PubMed1997

Platelet aggregation in patients bitten by the Brazilian snake Bothrops jararaca.

Patients bitten by the lancehead snake Bothrops jararaca usually develop systemic bleeding. Our aim was to evaluate platelet function in whole blood of 17 human patients bitten by this snake in São Paulo State, Brazil. Bleeding occurred in 71% of these patients, and thrombocytopenia in 53% of them. On admission, most of the patients presented with hypoaggregation to 50 microM ADP and 1.2 mg/ml ristocetin, and only 35% of them to 5 micrograms/ml collagen. Abnormal plasma levels of fibrinogen and fibrin(ogen) degradation products (FDP/fdp) were also observed. Twenty-four hours of finishing serumtherapy, bleeding had already ceased, fibrinogen and FDP/fdp levels returned to hemostatic levels, and values for platelet aggregation returned to the reference range of controls, except for ADP that still remained decreased. These findings evidence that disturbances of platelet function are also an important factor for the development of bleeding in Bothrops envenomation, as well as other known hemostatic disturbances that occur concomitantly.

Adolescent↗

PubMed2002

cDNA sequence and molecular modeling of a nerve growth factor from Bothrops jararacussu venomous gland.

The complete nucleotide sequence of a nerve growth factor precursor from Bothrops jararacussu snake (Bj-NGF) was determined by DNA sequencing of a clone from cDNA library prepared from the poly(A) + RNA of the venom gland of B. jararacussu. cDNA encoding Bj-NGF precursor contained 723 bp in length, which encoded a prepro-NGF molecule with 241 amino acid residues. The mature Bj-NGF molecule was composed of 118 amino acid residues with theoretical pI and molecular weight of 8.31 and 13,537, respectively. Its amino acid sequence showed 97%, 96%, 93%, 86%, 78%, 74%, 76%, 76% and 55% sequential similarities with NGFs from Crotalus durissus terrificus, Agkistrodon halys pallas, Daboia (Vipera) russelli russelli, Bungarus multicinctus, Naja sp., mouse, human, bovine and cat, respectively. Phylogenetic analyses based on the amino acid sequences of 15 NGFs separate the Elapidae family (Naja and Bungarus) from those Crotalidae snakes (Bothrops, Crotalus and Agkistrodon). The three-dimensional structure of mature Bj-NGF was modeled based on the crystal structure of the human NGF. The model reveals that the core of NGF, formed by a pair of beta-sheets, is highly conserved and the major mutations are both at the three beta-hairpin loops and at the reverse turn.

Amino Acid Sequence↗

PubMed2004

Alkylation of myotoxic phospholipases A2 in Bothrops moojeni venom: a promising approach to an enhanced antivenom production.

Bothrops moojeni crude venom (MjCV) and its two major toxins, namely myotoxin I (MjTX-I) and myotoxin II (MjTX-II) were alkylated by p-bromophenacyl bromide (BPB). After alkylation the i.p. LD(50) (mice) of MjCV and MjTX-I/II increased from 6.0 to 15.7mg/kg and from 8.0 to 45.0mg/kg, respectively. In addition, doses of 5x LD(50) of alkylated MjTX-I did not cause a single death in mice and no myonecrosis was detected for the alkylated toxins, although both proteins still induced edema. Antibodies to native and modified crude venom or myotoxins cross-reacted with 12 purified class II myotoxic phospholipases A(2) found in snake venoms of the genus Bothrops. Myotoxic PLA(2)s from class I and class III were not recognized by the above antibodies. These results suggest that the overall antigenic structure is conserved among class II myotoxic PLA(2)s, despite differences in their amino acid sequences. Anti-MjTX-I-BPB and anti-MjTX-II-BPB rabbit serum, obtained against the modified myotoxins, were apparently more efficient than those obtained against the native myotoxins. In neutralization experiments, pre-incubation of crude venom or isolated myotoxins with antibodies raised against the native or modified toxins inhibited their PLA(2) and myotoxic activities. Therefore, alkylation of His48 by BPB strongly reduces the local tissue damage induced by B. moojeni venom or isolated myotoxins while retaining antigenicity, which suggests a promising procedure for an enhanced antiophidian serum production for practical purposes.

Animals↗

PubMed2000

Isolation and characterization of myotoxin II from Atropoides (Bothrops) nummifer snake venom, a new Lys49 phospholipase A2 homologue.

Myotoxic phospholipases A2 of class II are commonly found in the venoms of crotalid snakes. As an approach to understanding their structure-activity relationship, diverse natural variants have been characterized biochemically and pharmacologically. This study describes a new myotoxic phospholipase A2 homologue, isolated from the venom of Atropoides (Bothrops) nummifer from Costa Rica. A. nummifer myotoxin 1 is a basic protein, with an apparent subunit molecular mass of 16 kDa, which migrates as a dimer in sodium dodecylsulfate-polyacrylamide gel electrophoresis under nonreducing conditions. It is strongly recognized by antibodies generated against Bothrops asper myotoxin II, by enzyme-immunoassay. The toxin induces rapid myonecrosis upon intramuscular injection in mice (evidenced by an early increase in plasma creatine kinase activity), and significant edema in the footpad assay. It also displays cytolytic activity upon cultured murine endothelial cells. The toxin (up to 50 microg) has no detectable phospholipase A2 activity on egg yolk phospholipids, and does not show an anticoagulant effect on sheep platelet-poor plasma in vitro. N-terminal sequence determination (53 amino acid residues) demonstrated that A. nummifer myotoxin II is a new Lys49 variant of the family of myotoxic, class II phospholipases A2. Sequence comparison with other phospholipases A2 revealed Asn53 as a novel substitution. In addition, this myotoxin is the first Lys49 variant presenting Asn in its N-terminus. Consequently, these findings suggest that neither Ser1 or Lys53, usually found in this family of proteins, are essential amino acid residues for their myotoxic, cytolytic, or edema-inducing effects.

Amino Acid Sequence↗

PubMed2002

Purification and characterization of a phosphodiesterase from Bothrops alternatus snake venom.

A phosphodiesterase was purified from the venom of the snake Bothrops alternatus by a combination of gel filtration and ion exchange chromatographies. In SDS-PAGE, the enzyme gave a single band with a molecular mass of 105 kDa, which was unaltered in the presence of beta-mercaptoethanol, indicating that the protein contained no subunits. A single protein band was also observed in native PAGE. There were no contaminating 5'-nucleotidase, alkaline phosphatase and protease activities. The enzyme was recognized by commercial bothropic antiserum and gave a single band in immunoblotting. The enzyme had a pH optimum in the range of 7.5-9.5 and the optimum temperature was 60 degrees C, with activity being rapidly lost within 1 min at > or = 70 degrees C. The Km of the enzyme was 2.69 mM. PDE activity was potentiated by cobalt and, to a lesser extent, by calcium, whereas copper, manganese, zinc, EDTA, and beta-mercaptoethanol were inhibitory. These properties show that this enzyme is very similar to that isolated from other snake venoms.

Animals↗

PubMed1997

Cloning and sequence analysis of a Bothrops jararaca cDNA encoding a precursor of seven bradykinin-potentiating peptides and a C-type natriuretic peptide.

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 indicated the predominant expression of a 1.8-kb mRNA in the venom glands as well as in the spleen and the brain. Two lower intensity mRNA bands of 3.5 kb and 5.7 kb also hybridized to the cDNA clone. Radioimmunoassay for the CNP was performed using the antiserum against rat CNP. The presence of CNP immunoreactivity was detected in the low molecular weight fraction of the Bothrops jararaca venom.

Amino Acid Sequence↗

PubMed2000

Envenoming by the South American pit viper Bothrops neuwiedi Wagler.

Between 1975 and 1992, 18 cases of envenoming by Bothrops neuwiedi presented at the Hospital Vital Brazil, in São Paulo. Most of these cases were male (67%) and most had been bitten during the day (83%), between November and May (83%), either on the foot/ankle (50%) or hand (39%). Most (72%) of the cases arrived at the hospital 1-6 h after the bite. All presented with pain and most (83%) had oedema, but fewer had ecchymosis (50%), necrosis (17%), abscess (5%) and/or systemic blood-coagulation disorders (12%). Polyspecific Bothrops antivenom was administered to 16 (89%) of the patients. The results of B. neuwiedi bites therefore appear very similar to those of the much better known B. jararaca, even in terms of the gravity of the envenoming. Impairment in blood coagulation, however, seems less frequent among those bitten by B. neuwiedi than in those bitten by B. jararaca.

Adolescent↗

PubMed1999

Prognostic factors for amputation in the case of envenoming by snakes of the Bothrops genus (Viperidae).

The prognostic factors for amputation following envenoming by snakes of the Bothrops genus were identified from the medical records of 3139 patients. Each of these patients had been bitten by Bothrops sp. and treated in the Hospital Vital Brazil, in São Paulo, Brazil, between 1981 and 1990. The 21 (0.67%) of the patients who had undergone amputation were compared with the 3118 who had not, with respect to the characteristics of the accident, the snake, the victim, the local and systemic manifestations of the envenoming and the treatment. There was an association between amputation and the month of the accident, the time of day when the accident happened, the length of the attacking snake, the anatomical region bitten, systemic bleeding and renal failure. Patients bitten in the fingers, during the cooler months, between 00.00 and 12.00 hours and/or by snakes > 60 cm in length, who developed blisters and abscesses at the site of the bite, systemic bleeding and/or renal failure underwent amputation more frequently than the others (P < 0.05 for each).

Adolescent↗

PubMed2000

Bothrops asper snake venom and its metalloproteinase BaP-1 activate the complement system. Role in leucocyte recruitment.

The venom of the snake Bothrops asper, the most important poisonous snake in Central America, evokes an inflammatory response, the mechanisms of which are not well characterized. The objectives of this study were to investigate whether B. asper venom and its purified toxins--phospholipases and metalloproteinase--activate the complement system and the contribution of the effect on leucocyte recruitment. In vitro chemotaxis assays were performed using Boyden's chamber model to investigate the ability of serum incubated with venom and its purified toxins to induce neutrophil migration. The complement consumption by the venom was evaluated using an in vitro haemolytic assay. The importance of complement activation by the venom on neutrophil migration was investigated in vivo by injecting the venom into the peritoneal cavity of C5-deficient mice. Data obtained demonstrated that serum incubated with crude venom and its purified metalloproteinase BaP-1 are able to induce rat neutrophil chemotaxis, probably mediated by agent(s) derived from the complement system. This hypothesis was corroborated by the capacity of the venom to activate this system in vitro. The involvement of C5a in neutrophil chemotaxis induced by venom-activated serum was demonstrated by abolishing migration when neutrophils were pre-incubated with antirat C5a receptor antibody. The relevance of the complement system in in vivo leucocyte mobilization was further demonstrated by the drastic decrease of this response in C5-deficient mice. Pre-incubation of serum with the soluble human recombinant complement receptor type 1 (sCR 1) did not prevent the response induced by the venom, but abolished the migration evoked by metalloproteinase-activated serum. These data show the role of the complement system in bothropic envenomation and the participation of metalloproteinase in the effect. Also, they suggest that the venom may contain other component(s) which can cause direct activation of C5a.

Amino Acid Sequence↗

PubMed2000

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

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.

Animals↗

PubMed1998

Local inflammation, lethality and cytokine release in mice injected with Bothrops atrox venom.

We have provided evidence that: (a) lethality of mice to crude Bothrops venom varies according the isogenic strain (A/J > C57Bl/6 > A/Sn > BALB/c > C3H/HePas > DBA/2 > C3H/He); (b)BALB/c mice (LD50=100.0 microg) were injected i.p. with 50 microg of venom produced IL-6, IL-10, INF-gamma, TNF-alpha and NO in the serum. In vitro the cells from the mice injected and challenged with the venom only released IL-10 while peritoneal macrophages released IL-10, INF-gamma and less amounts of IL-6; (c) establishment of local inflammation and necrosis induced by the venom, coincides with the peaks of TNF-alpha, IFN-gamma and NO and the damage was neutralized when the venom was incubated with a monoclonal antibody against a 60 kDa haemorrhagic factor. These results suggest that susceptibility to Bothrops atrox venom is genetically dependent but MHC independent; that IL-6, IL-10, TNF-alpha, IFN-gamma and NO can be involved in the mediation of tissue damage; and that the major venom component inducers of the lesions are haemorrhagins.

Animals↗