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Id: lil-525817
Autor: Martins, L. J; de Araújo, P. M. F; Bon, C; Hyslop, S; de Araújo, A. L.
Título: In vitro hemolytic activity of Bothrops lanceolatus (fer-de-lance) venom
Fonte: J. venom. anim. toxins incl. trop. dis;15(3):498-508, 2009. ilus.
Idioma: en.
Resumo: Bothrops lanceolatus venom contains a variety of enzymatic and biological activities. The present work investigated the hemolytic activity of this venom and its phospholipase A2 (PLA2). Bothrops lanceolatus venom (6.7 µg/mL) caused indirect hemolysis of cow, horse, rat and sheep erythrocytes, with horse erythrocytes being the most sensitive; no direct hemolysis was observed. Hemolysis in sheep erythrocytes was concentration-dependent (5-11.7 µg/mL) and markedly attenuated by heating the venom for 30 minutes at ≥ 40°C and by the PLA2 inhibitor p-bromophenacyl bromide. An acidic PLA2 (5 µg/mL) purified from B. lanceolatus venom also caused hemolysis. This PLA2 showed immunoprecipitin lines with antivenom against B. lanceolatus, which suggests that the enzymatic and hemolytic activities of this enzyme may be neutralized during antivenom therapy. These results indicate that B. lanceolatus venom and its PLA2 can cause hemolysis in vitro.(AU)
Descritores: Técnicas In Vitro
Bothrops lanceolatus
Venenos Elapídicos/toxicidade
Enzimas
Fosfolipases A2
-Produtos Biológicos
Hemólise
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: lil-623508
Autor: Yap, M. K. K; Tan, N. H; Fung, S. Y.
Título: Biochemical and toxinological characterization of Naja sumatrana (Equatorial spitting cobra) venom
Fonte: J. venom. anim. toxins incl. trop. dis;17(4):451-459, 2011. tab, ilus.
Idioma: en.
Projeto: Government of Malaysia.
Resumo: The lethal and enzymatic activities of venom from Naja sumatrana (Equatorial spitting cobra) were determined and compared to venoms from three other Southeast Asian cobras (Naja sputatrix, Naja siamensis and Naja kaouthia). All four venoms exhibited the common characteristic enzymatic activities of Asiatic cobra venoms: low protease, phosphodiesterase, alkaline phosphomonoesterase and L-amino acid oxidase activities, moderately high acetylcholinesterase and hyaluronidase activities and high phospholipase A2. Fractionation of N. sumatrana venom by Resource® S cation exchange chromatography (GE Healthcare, USA) yielded nine major protein peaks, with all except the acidic protein peak being lethal to mice. Most of the protein peaks exhibit enzymatic activities, and L-amino acid oxidase, alkaline phosphomonoesterase, acetylcholinesterase, 5'-nucleotidase and hyaluronidase exist in multiple forms. Comparison of the Resource® S chromatograms of the four cobra venoms clearly indicates that the protein composition of N. sumatrana venom is distinct from venoms of the other two spitting cobras, N. sputatrix (Javan spitting cobra) and N. siamensis (Indochinese spitting cobra). The results support the revised systematics of the Asiatic cobra based on multivariate analysis of morphological characters. The three spitting cobra venoms exhibit two common features: the presence of basic, potentially pharmacologically active phospholipases A2 and a high content of polypeptide cardiotoxin, suggesting that the pathophysiological actions of the three spitting cobra venoms may be similar.(AU)
Descritores: Fenômenos Bioquímicos
Cromatografia
Venenos Elapídicos
Cardiotoxinas
Elapidae
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-954790
Autor: Clement, Herlinda; Flores, Vianey; la Rosa, Guillermo De; Zamudio, Fernando; Alagon, Alejandro; Corzo, Gerardo.
Título: Heterologous expression, protein folding and antibody recognition of a neurotoxin from the Mexican coral snake Micrurus laticorallis
Fonte: J. venom. anim. toxins incl. trop. dis;22:25, 2016. graf.
Idioma: en.
Projeto: Dirección General de Asuntos del Personal Académico; . SEP-CONACyT.
Resumo: Background The cysteine-rich neurotoxins from elapid venoms are primarily responsible for human and animal envenomation; however, their low concentration in the venom may hamper the production of efficient elapid antivenoms. Therefore, the aim of the present study was to produce fully active elapid neurotoxic immunogens for elapid antivenom production. Method Cysteine-rich neurotoxins showed recombinant expression in two strains of E. coli, and were purified using affinity chromatography and reverse-phase HPLC (rpHPLC). Results The cDNA of the four disulfide-bridged peptide neurotoxin Mlat1 was cloned into a modified expression vector, pQE30, which was transfected into two different E. coli strains. The recombinant toxin (HisrMlat1) was found only in inclusion bodies in M15 strain cells, and in both inclusion bodies and cytoplasm in Origami strain cells. The HisrMlat1 from inclusion bodies from M15 cells was solubilized using guanidine hydrochloride, and then purified by rpHPLC. It showed various contiguous fractions having the same molecular mass, indicating that HisrMlat1 was oxidized after cell extraction forming different misfolded disulfide bridge arrangements without biological activity. In vitro folding conditions of the misfolded HisrMlat1 generated a biologically active HisrMlat1. On the other hand, the HisrMlat1 from the cytoplasm from Origami cells was already soluble, and then purified by HPLC. It showed a single fraction with neurotoxic activity; so, no folding steps were needed. The in vitro folded HisrMlat1 from M15 cells and the cytoplasmic soluble HisrMlat1from Origami cells were indistinguishable in their structure and neurotoxicity. Rabbit polyclonal antibodies raised up against biologically active HisrMlat1 recognized the native Mlat1 (nMlat1) from the whole venom of M. laticorallis. In addition, HisrMlat1 was recognized by horse polyclonal antibodies obtained from the immunization of elapid species from sub-Saharan Africa. Conclusion HisrMlat1 shows increased biological activities compared to the native peptide, and may be used as an immunizing agent in combination with other toxic components such phospholipases type A2 for elapid antivenom production.(AU)
Descritores: Dobramento de Proteína
Elapidae
Venenos Elapídicos
Anticorpos
Neurotoxinas
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-1356458
Autor: Tan, Choo Hock; Bourges, Aymeric; Tan, Kae Yi.
Título: King Cobra and snakebite envenomation: on the natural history, human-snake relationship and medical importance of Ophiophagus hannah
Fonte: J. venom. anim. toxins incl. trop. dis;27:e20210051, 2021. tab, graf, ilus.
Idioma: en.
Projeto: University of Malaya.
Resumo: King Cobra (Ophiophagus hannah) has a significant place in many cultures, and is a medically important venomous snake in the world. Envenomation by this snake is highly lethal, manifested mainly by neurotoxicity and local tissue damage. King Cobra may be part of a larger species complex, and is widely distributed across Southeast Asia, southern China, northern and eastern regions as well as the Western Ghats of India, indicating potential geographical variation in venom composition. There is, however, only one species-specific King Cobra antivenom available worldwide that is produced in Thailand, using venom from the snake of Thai origin. Issues relating to the management of King Cobra envenomation (e.g., variation in the composition and toxicity of the venom, limited availability and efficacy of antivenom), and challenges faced in the research of venom (in particular proteomics), are rarely addressed. This article reviews the natural history and sociocultural importance of King Cobra, cases of snakebite envenomation caused by this species, current practice of management (preclinical and clinical), and major toxinological studies of the venom with a focus on venom proteomics, toxicity and neutralization. Unfortunately, epidemiological data of King Cobra bite is scarce, and venom proteomes reported in various studies revealed marked discrepancies in details. Challenges, such as inconsistency in snake venom sampling, varying methodology of proteomic analysis, lack of mechanistic and antivenomic studies, and controversy surrounding antivenom use in treating King Cobra envenomation are herein discussed. Future directions are proposed, including the effort to establish a standard, comprehensive Pan-Asian proteomic database of King Cobra venom, from which the venom variation can be determined. Research should be undertaken to characterize the toxin antigenicity, and to develop an antivenom with improved efficacy and wider geographical utility. The endeavors are aligned with the WHO´s roadmap that aims to reduce the disease burden of snakebite by 50% before 2030.(AU)
Descritores: Envenenamento
Mordeduras de Serpentes
Serpentes
Antivenenos
Proteoma
Venenos Elapídicos
-História Natural
Limites: Animais
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-954814
Autor: Zambelli, Vanessa Olzon; Chioato, Lucimara; Gutierrez, Vanessa Pacciari; Ward, Richard John; Cury, Yara.
Título: Structural determinants of the hyperalgesic activity of myotoxic Lys49-phospholipase A2
Fonte: J. venom. anim. toxins incl. trop. dis;23:7, 2017. graf.
Idioma: en.
Projeto: State of São Paulo Research Foundation.
Resumo: Background Bothropstoxin-I (BthTx-I) is a Lys49-phospholipase A2 (Lys49-PLA2) from the venom of Bothrops jararacussu, which despite of the lack of catalytic activity induces myotoxicity, inflammation and pain. The C-terminal region of the Lys49-PLA2s is important for these effects; however, the amino acid residues that determine hyperalgesia and edema are unknown. The aim of this study was to characterize the structural determinants for the Lys49-PLA2-induced nociception and inflammation. Methods Scanning alanine mutagenesis in the active-site and C-terminal regions of BthTx-I has been used to study the structural determinants of toxin activities. The R118A mutant was employed as this substitution decreases PLA2 myotoxicity. In addition, K115A and K116A mutants - which contribute to decrease cytotoxicity - and the K122A mutant - which decreases both myotoxicity and cytotoxicity - were also used. The H48Q mutant - which does not interfere with membrane damage or myotoxic activity - was used to evaluate if the PLA2 catalytic site is relevant for the non-catalytic PLA2-induced pain and inflammation. Wistar male rats received intraplantar injections with mutant PLA2. Subsequently, hyperalgesia and edema were evaluated by the paw pressure test and by a plethysmometer. Native and recombinant BthTx-I were used as controls. Results Native and recombinant BthTx-I induced hyperalgesia and edema, which peaked at 2 h. The R118A mutant did not induce nociception or edema. The mutations K115A and K116A abolished hyperalgesia without interfering with edema. Finally, the K122A mutant did not induce hyperalgesia and presented a decreased inflammatory response. Conclusions The results obtained with the BthTx-I mutants suggest, for the first time, that there are distinct residues responsible for the hyperalgesia and edema induced by BthTx-I. In addition, we also showed that cytolytic activity is essential for the hyperalgesic effect but not for edematogenic activity, corroborating previous data showing that edema and hyperalgesia can occur in a non-dependent manner. Understanding the structure-activity relationship in BthTx-I has opened new possibilities to discover the target for PLA2-induced pain.(AU)
Descritores: Bothrops
Venenos Elapídicos
Fosfolipases A2
Miotoxicidade
Hiperalgesia
Inflamação
Limites: Animais
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-954836
Autor: Chippaux, Jean-Philippe.
Título: Snakebite envenomation turns again into a neglected tropical disease!
Fonte: J. venom. anim. toxins incl. trop. dis;23:38, 2017.
Idioma: en.
Resumo: On June 9th, 2017 WHO categorized snakebite envenomation into the Category A of the Neglected Tropical Diseases. This new situation will allow access to new funding, paving the way for wider and deeper researches. It should also expand the accessibility of antivenoms. Let us hope that it also leads to cooperation among stakeholders, aiming at improving the management of snakebites in developing countries.(AU)
Descritores: Envenenamento
Mordeduras de Serpentes
Antivenenos
Venenos Elapídicos
Limites: Animais
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-1012635
Autor: Bezerra, Patrícia Heloise Alves; Ferreira, Isadora Marques; Franceschi, Beatriz Tinoco; Bianchini, Francine; Ambrósio, Luciana; Cintra, Adélia Cristina O; Sampaio, Suely Vilela; Castro, Fabíola Attié de; Torqueti, Maria Regina.
Título: BthTX-I from Bothrops jararacussu induces apoptosis in human breast cancer cell lines and decreases cancer stem cell subpopulation
Fonte: J. venom. anim. toxins incl. trop. dis;25:e20190010, 2019. graf.
Idioma: en.
Resumo: Breast cancer is the neoplasm with both the highest incidence and mortality rate among women worldwide. Given the known snake venom cytotoxicity towards several tumor types, we evaluated the effects of BthTX-I from Bothrops jararacussu on MCF7, SKBR3, and MDAMB231 breast cancer cell lines. Methods: BthTX-I cytotoxicity was determined via MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay. Cell death was measured by a hypotonic fluorescent solution method, annexin-V-FITC/propidium iodide staining and by apoptotic/autophagic protein expression. Cancer stem cells (CSCs) were quantified by flow cytometry using anti-CD24-FITC and anti-CD44-APC antibodies and propidium iodide. Results: BthTX-I at 102 µg/mL induced cell death in all cell lines. The toxin induced apoptosis in MCF7, SKBR3, and MDAMB231 in a dose-dependent manner, as confirmed by the increasing number of hypodiploid nuclei. Expression of pro-caspase 3, pro-caspase 8 and Beclin-1 proteins were increased, while the level of the antiapoptotic protein Bcl-2 was diminished in MCF7 cells. BthTX-I changed the staining pattern of CSCs in MDAMB231 cells by increasing expression of CD24 receptors, which mediated cell death. Conclusions: BthTX-I induces apoptosis and autophagy in all breast cancer cell lines tested and also reduces CSCs subpopulation, which makes it a promising therapeutic alternative for breast cancer.(AU)
Descritores: Células-Tronco Neoplásicas
Neoplasias da Mama
Apoptose
Bothrops
Venenos Elapídicos/síntese química
-Citometria de Fluxo
Limites: Humanos
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-1056676
Autor: Santos, Roberta Tancredi Francesco dos; Silva, Marcelo Florencio Passos; Porto, Rafael Marques; Lebrun, Ivo; Gonçalves, Luís Roberto de Camargo; Batista, Isabel de Fátima Correia; Sandoval, Maria Regina Lopes; Abdalla, Fernando Maurício Francis.
Título: Effects of Mlx-8, a phospholipase A2 from Brazilian coralsnake Micrurus lemniscatus venom, on muscarinic acetylcholine receptors in rat hippocampus
Fonte: J. venom. anim. toxins incl. trop. dis;26:e20190041, 2020. graf.
Idioma: en.
Projeto: FAPESP.
Resumo: Here, we described the presence of a neurotoxin with phospholipase A2 activity isolated from Micrurus lemniscatus venom (Mlx-8) with affinity for muscarinic acetylcholine receptors (mAChRs). Methods: The purification, molecular mass determination, partial amino acid sequencing, phospholipase A2 activity determination, inhibition of the binding of the selective muscarinic ligand [3H]QNB and inhibition of the total [3H]inositol phosphate accumulation in rat hippocampus of the Mlx-8 were determined. Results: Thirty-one fractions were collected from HPLC chromatography, and the Mlx-8 toxin was used in this work. The molecular mass of Mlx-8 is 13.628 Da. Edman degradation yielded the following sequence: NLYQFKNMIQCTNTRSWL-DFADYG-CYCGRGGSGT. The Mlx-8 had phospholipase A2 enzymatic activity. The pKi values were determined for Mlx-8 toxin and the M1 selective muscarinic antagonist pirenzepine in hippocampus membranes via [3H]QNB competition binding assays. The pKi values obtained from the analysis of Mlx-8 and pirenzepine displacement curves were 7.32 ± 0.15, n = 4 and 5.84 ± 0.18, n = 4, respectively. These results indicate that Mlx-8 has affinity for mAChRs. There was no effect on the inhibition ability of the [3H]QNB binding in hippocampus membranes when 1 µM Mlx-8 was incubated with 200 µM DEDA, an inhibitor of phospholipase A2. This suggests that the inhibition of the phospholipase A2 activity of the venom did not alter its ability to bind to displace [3H]QNB binding. In addition, the Mlx-8 toxin caused a blockade of 43.31 ± 8.86%, n = 3 and 97.42 ± 2.02%, n = 3 for 0.1 and 1 µM Mlx-8, respectively, on the total [3H]inositol phosphate content induced by 10 µM carbachol. This suggests that Mlx-8 inhibits the intracellular signaling pathway linked to activation of mAChRs in hippocampus. Conclusion: The results of the present work show, for the first time, that muscarinic receptors are also affected by the Mlx-8 toxin, a muscarinic ligand with phospholipase A2 characteristics, obtained from the venom of the Elapidae snake Micrurus lemniscatus, since this toxin was able to compete with muscarinic ligand [3H]QNB in hippocampus of rats. In addition, Mlx-8 also blocked the accumulation of total [3H]inositol phosphate induced by muscarinic agonist carbachol. Thus, Mlx-8 may be a new pharmacological tool for examining muscarinic cholinergic function.(AU)
Descritores: Serpentes
Venenos Elapídicos/efeitos adversos
Fosfolipases A2
Fosfatos de Inositol
-Acetilcolina
Receptores Muscarínicos/análise
Análise de Sequência de Proteína
Limites: Animais
Ratos
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-1091017
Autor: Fortes-Dias, Consuelo L; Macedo, Diego Henrique Fagundes; Barbosa, Rafaella Pereira; Souza-Silva, Gabriel; Ortolani, Paula Ladeira.
Título: Identification and characterization of the first endogenous phospholipase A2 inhibitor from a non-venomous tropical snake, Boa constrictor (Serpentes: Boidae)
Fonte: J. venom. anim. toxins incl. trop. dis;26:e20190044, 2020. tab, graf.
Idioma: en.
Resumo: Abstract Background: Endogenous phospholipase A2 inhibitors from snake blood (sbPLIs) have been isolated from several species around the world, with the primary function of self-protection against the action of toxic phospholipases A2. In American snakes, sbPLIs were solely described in pit vipers, in which the natural protection role is justified. In this study, we described a sbPLI in Boa constrictor (popularly known as jiboia), a non-venomous snake species from America. Methods: PLA2 inhibitory activity was tested in the blood plasma of B. constrictor using C. d. terrificus venom as the enzyme source. Antibodies developed against CNF, a sbγPLI from Crotalus durissus terrificus, were used to investigate the presence of homologues in the blood plasma of B. constrictor. A CNF-like molecule with a PLA2 inhibitory activity was purified by column chromatography. The encoding gene for the inhibitor was cloned from B. constrictor liver tissue. The DNA fragment was cloned, purified and sequenced. The deduced primary sequence of interest was aligned with known sbγPLIs from the literature. Results: The blood plasma of B. constrictor displayed PLA2 inhibitory activity. A CNF-like molecule (named BcNF) was identified and purified from the blood plasma of B. constrictor. Basic properties such as molecular mass, composing amino acids, and pI were comparable, but BcNF displayed reduced specific activity in PLA2 inhibition. BcNF showed highest identity scores (ISs) with sbγPLIs from pit vipers from Latin America (90-100%), followed by gamma inhibitors from Asian viperid (80-90%). ISs below 70% were obtained for BcNF and non-venomous species from Asia. Conclusion: A functional sbγPLI (BcNF) was described in the blood plasma of B. constrictor. BcNF displayed higher primary identity with sbγPLIs from Viperidae than to sbγPLIs from non-venomous species from Asia. The physiological role played by sbγPLIs in non-venomous snake species remains to be understood. Further investigation is needed.(AU)
Descritores: Serpentes
Viperidae
Venenos Elapídicos
Fosfolipases A2
Inibidores de Fosfolipase A2
Limites: Animais
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-1091019
Autor: Attarde, Saurabh S; Pandit, Sangeeta V.
Título: Anticancer potential of nanogold conjugated toxin GNP-NN-32 from Naja naja venom
Fonte: J. venom. anim. toxins incl. trop. dis;26:e20190047, 2020. graf, ilus.
Idioma: en.
Resumo: Background: Cancer is the second most common fatal disease in the world, behind cardiovascular disorders in the first place. It accounts for around 0.3 million deaths per year in India due to the lack of proper diagnostic facilities, prevention and treatment. Current therapeutic methods do not provide adequate protection and affect normal cells along with cancerous ones. Thus, there is a need for some alternative therapeutic strategy, preferably from natural products, which have been traditionally used for treatment of various diseases in the country. Methods: In this study, we have conjugated purified NN-32 toxin from Naja naja venom with gold nanoparticles and its anticancer potential was evaluated against human breast cancer cell lines. UV-Vis spectroscopy, dynamic light scattering, transmission electron microscopy, atomic force microscopy and zeta potential analysis were the techniques used for characterization of GNP-NN-32. Results: GNP-NN-32 showed dose- and time-dependent cytotoxicity against breast cancer cell lines (MCF-7 and MDA-MB-231). NN-32 and GNP-NN-32 induced apoptosis in both breast cancer cell lines. The results of CFSE cell proliferation study revealed that NN-32 and GNP-NN-32 arrested cell division in both MCF-7 and MDA-MB-231 cell lines resulting in inhibition of proliferation of these cancer cells. Conclusion: GNP-NN-32 showed an anticancer potential against human breast cancer cell lines. Analysis of detailed chemical characterization along with its cytotoxic property might help to perceive a new dimension of the anti-cancer potential of GNP-NN-32 that will enhance its biomedical function in near future.(AU)
Descritores: Venenos Elapídicos
Naja naja
Antineoplásicos
Limites: Animais
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice



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