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Registros recuperados: 33 | |
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Medhioub, Walid; Ramondenc, Simon; Vanhove, Audrey; Vergnes, Agnes; Masseret, Estelle; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc. |
This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h,... |
Tipo: Text |
Palavras-chave: Shellfish; Toxins; Apoptosis; Gene expression. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28744/27213.pdf |
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Couet, Douglas; Pringault, Olivier; Bancon-montigny, Chrystelle; Briant, Nicolas; Poulichet, Francoise Elbaz; Delpoux, Sophie; Yahia, Ons Kefi-daly; Hela, Bengharbia; Charaf, M'Rabet; Herve, Fabienne; Rovillon, Georges-augustin; Amzil, Zouher; Laabir, Mohamed. |
Controlled laboratory experiments were conducted to test the effects of copper (Cu2+) and butyltins (BuT) on the growth, photosynthetic activity and toxin content of two HABs (Harmful Algal Blooms) dinoflagellates, the planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata. Microalgae were exposed to increasing concentrations of Cu2+ (10−4 to 31 nM) or BuT (0.084 to 84 nM) for seven days. When considering the growth, EC50 values were 0.16 (±0.09) nM and 0.03 (±0.02) nM of Cu2+ for A. catenella and O. cf. ovata, respectively. Regarding BuT, EC50 was 14.2 (±6) nM for O. cf. ovata, while A. catenella growth inhibition appeared at BuT concentrations ≥27 nM. Photosynthetic activity of the studied dinoflagellates decreased with increasing Cu and... |
Tipo: Text |
Palavras-chave: Alexandrium catenella; Ostreopsis cf. ovata; Cu; Butyltin; Photosynthesis; Toxins. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00418/52970/53896.pdf |
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Chomérat, Nicolas; Bilien, Gwenael; Derrien, Amelie; Henry, Kévin; Ung, André; Viallon, Jérôme; Darius, Hélène Taiana; Mahana Iti Gatti, Clémence; Roué, Mélanie; Hervé, Fabienne; Réveillon, Damien; Amzil, Zouher; Chinain, Mireille. |
To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French... |
Tipo: Text |
Palavras-chave: ITS-5.8S rDNA; LSU rDNA; Microscopy; Ostreopsis lenticularis; Taxonomy; Toxins. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59747/62887.pdf |
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Tetreau, Guillaume. |
Toxins are a major virulence factor produced by many pathogenic bacteria. In vertebrates, the response of hosts to the bacteria is inseparable from the response to the toxins, allowing a comprehensive understanding of this tripartite host-pathogen-toxin interaction. However, in invertebrates, this interaction has been investigated by two complementary but historically distinct fields of research: toxinology and immunology. In this article, I highlight how such dichotomy between these two fields led to a biased, or even erroneous view of the ecology and evolution of the interaction between insects, toxins, and bacteria. I focus on the reason behind such a dichotomy, on how to bridge the fields together, and on confounding effects that could bias the outcome... |
Tipo: Text |
Palavras-chave: Invertebrate immunity; Host-pathogens interaction; Toxins; Bacillus thuringiensis; Resistance. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00457/56834/78950.pdf |
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Perez-pascual, David; Lunazzi, Aurelie; Magdelenat, Ghislaine; Rouy, Zoe; Roulet, Alain; Lopez-roques, Celine; Larocque, Robert; Barbeyron, Tristan; Gobet, Angelique; Michel, Gurvan; Bernardet, Jean-francois; Duchaud, Eric. |
Tenacibaculum maritimum is a devastating bacterial pathogen of wild and farmed marine fish with a broad host range and a worldwide distribution. We report here the complete genome sequence of the T. maritimum type strain NCIMB 2154(T). The genome consists of a 3,435,971-base pair circular chromosome with 2,866 predicted protein-coding genes. Genes encoding the biosynthesis of exopolysaccharides, the type IX secretion system, iron uptake systems, adhesins, hemolysins, proteases, and glycoside hydrolases were identified. They are likely involved in the virulence process including immune escape, invasion, colonization, destruction of host tissues, and nutrient scavenging. Among the predicted virulence factors, type IX secretion-mediated and cell-surface... |
Tipo: Text |
Palavras-chave: Tenacibaculum maritimum; Fish pathogen; Virulence factors; Genome; Toxins. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00488/59939/63150.pdf |
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LIPPS,B. V.. |
Lethal Toxin Neutralizing Factor (N-LTNF), MW 63.0 kDa, was isolated from opossum serum. After trypsin digestion, the active domain of N-LTNF was isolated and sequenced. The synthetic peptide consisting of ten amino acids was designated as LT-10. N-LTNF and LT-10 inhibited the lethality of animal, plant and bacteria toxins when tested on mice non-immunologically. The antibodies against N-LTNF and LT-10 only reacted immunologically with toxins and not with non-toxic substances. Anti-LTNF and anti-LT-10 reacted immunologically by ELISA test with toxins that were not detected by mouse test, such as cholera toxin and digoxin. Anti-LTNF and anti-LT-10 failed to react immunologically with non-toxic substances, such as nerve growth factor and collagen. Currently,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antibodies; In vitro assay; Lethal toxin neutralizing factor; Toxins; Venoms. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-79302002000200003 |
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Sciani,Juliana Mozer; Zychar,Bianca; Gonçalves,Luis Roberto; Giorgi,Renata; Nogueira,Thiago; Pimenta,Daniel Carvalho. |
Abstract Background Sea urchins are animals commonly found on the Brazilian shoreline, being Echinometra lucunter the most abundant species. Accidents caused by E. lucunter have been reported as one of the most frequent in Brazil, and are characterized by intense pain and inflammation, consequence of spine puncture in the skin. In order to characterize such toxic effects, we isolated one molecule that caused inflammatory and nociceptive effects. Methods E. lucunter specimens were collected without gender distinction. Spines were removed and molecules were extracted, fractionated by RP-HPLC and assayed for inflammatory and nociceptive activity, in a biological-driven fractionation way, until the obtainment of one active molecule and its subsequent... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Toxins; Sea urchin; Echinometra lucunter; Spines; Inflammation. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100318 |
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Daniel-Ribeiro,Cláudio Tadeu; Roussilhon,Christian. |
Abstract The authors report a series of events including the scientific interest for poisonous dendrobates of French Guiana, the human confrontation with the immensity of the evergreen rainforest, the fragility of the best-prepared individuals to a rough life, and the unique and very special manifestation of a solid friendship between two experts and enthusiasts of outdoor life. In the evergreen forest of South America, as in many other scientific field expeditions, everything may suddenly go wrong, and nothing can prepare researchers to accidents that may occur in a succession of uncontrollable errors once the first mistake is done. This is what happened during an expedition in search for dendrobates by an experienced forest guide and naturalist. The... |
Tipo: Info:eu-repo/semantics/report |
Palavras-chave: Dart frogs; Dendrobatidae; Toxins; French Guiana. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992016000100501 |
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Chaves-Moreira,Daniele; Senff-Ribeiro,Andrea; Wille,Ana Carolina Martins; Gremski,Luiza Helena; Chaim,Olga Meiri; Veiga,Silvio Sanches. |
Abstract Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (4–40 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brown spider; Loxosceles; Venom; Toxins; Loxoscelism; Phospholipase-D; Metalloprotease; Insecticidal peptides; Serineprotease; Hyaluronidase. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100201 |
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Soares,A. M.; Oliveira,C. Z.; Santana,C. D.; Menaldo,D. L.; Silveira,L. B.; Teixeira,S. S.; Rueda,A. Q.; Marcussi,S.. |
This work succinctly describes the professional and scientific life of Dr. José R. Giglio, one of the most outstanding Brazilian researchers in the field of Toxinology. During his long and successful career, he has made major contributions, especially in elucidating the function, structure, and mechanisms of action of animal venom proteins (from snakes, scorpions and spiders) as well as the characterization of antibodies and several inhibitors of venoms and toxins. We present here a brief history of Dr. Giglios personal and professional life, also reporting some of his numerous published scientific articles on venoms from snakes (Bothrops, Crotalus, and other genera), scorpions (Tityus sp), spiders (Phoneutria sp), their isolated toxins and natural... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Toxinology; Animal venoms; Toxins; Inhibitors; Homage; Giglio JR. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992007000400003 |
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Menaldo,Danilo L.; Jacob-Ferreira,Anna L.; Bernardes,Carolina P.; Cintra,Adélia C. O.; Sampaio,Suely V.. |
Background Snake venoms are complex mixtures of inorganic and organic components, mainly proteins and peptides. Standardization of methods for isolating bioactive molecules from snake venoms is extremely difficult due to the complex and highly variable composition of venoms, which can be influenced by factors such as age and geographic location of the specimen. Therefore, this study aimed to standardize a simple purification methodology for obtaining a P-I class metalloprotease (MP) and an acidic phospholipase A2 (PLA 2 ) from Bothrops atroxvenom, and biochemically characterize these molecules to enable future functional studies.Methods To obtain the toxins of interest, a method has been standardized using consecutive isolation steps. The purity level of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Snake venoms; Bothrops atrox; Toxins; Metalloprotease; Phospholipase A2; Isolation; Characterization; Chromatography. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992015000100337 |
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Tasima,Lídia J.; Serino-Silva,Caroline; Hatakeyama,Daniela M.; Nishiduka,Erika S.; Tashima,Alexandre K.; Sant’Anna,Sávio S.; Grego,Kathleen F.; Morais-Zani,Karen de; Tanaka-Azevedo,Anita M.. |
Abstract Background: Crotalus durissus is considered one of the most important species of venomous snakes in Brazil, due to the high mortality of its snakebites. The venom of Crotalus durissus contains four main toxins: crotoxin, convulxin, gyroxin and crotamine. Venoms can vary in their crotamine content, being crotamine-negative or -positive. This heterogeneity is of great importance for producing antivenom, due to their different mechanisms of action. The possibility that antivenom produced by Butantan Institute might have a different immunorecognition capacity between crotamine-negative and crotamine-positive C. durissus venoms instigated us to investigate the differences between these two venom groups. Methods: The presence of crotamine was analyzed... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rattlesnake; Snake venom; Toxins; Venom variation; Antivenom. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992020000100307 |
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Barbosa,Alexandre Naime; Boyer,Leslie; Chippaux,Jean-Philippe; Medolago,Natalia Bronzatto; Caramori,Carlos Antonio; Paixão,Ariane Gomes; Poli,João Paulo Vasconcelos; Mendes,Mônica Bannwart; Santos,Lucilene Delazari dos; Ferreira Jr,Rui Seabra; Barraviera,Benedito. |
Abstract Background Envenomation caused by multiple stings from Africanized honeybees Apis mellifera constitutes a public health problem in the Americas. In 2015, the Brazilian Ministry of Health reported 13,597 accidents (incidence of seven cases per 100,000 inhabitants) with 39 deaths (lethality of 0.25%). The toxins present in the venom, which include melittin and phospholipase A2, cause lesions in diverse organs and systems that may be fatal. As there has been no specific treatment to date, management has been symptomatic and supportive only. Methods In order to evaluate the safety and neutralizing capacity of a new apilic antivenom, as well as to confirm its lowest effective dose, a clinical protocol was developed to be applied in a multicenter,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Apis mellifera; Bee venom; Toxins; Envenomation; Heterologous serum; Apilic antivenom; Bee antivenom. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100309 |
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Tan,CH; Sim,SM; Gnanathasan,CA; Fung,SY; Ponnudurai,G; Pailoor,J; Tan,NH. |
Hypnale hypnale (hump-nosed pit viper) has been recently identified as one of the medically important venomous snakes in Sri Lanka and on the southwestern coast of India. The characterization of its venom is essential for understanding the pathophysiology of envenomation and for optimizing its management. In the present study, the biological properties of Hypnale hypnale venom and venom fractions obtained using Resource Q ion exchange chromatography were determined. The venom exhibited toxic activities typical of pit viper venom, comparable to that of its sister taxon, the Malayan pit viper (Calloselasma rhodostoma). Particularly noteworthy were its high activities of thrombin-like enzyme, proteases, phospholipase A2, L-amino acid oxidase and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hypnale hypnale; Venom; Enzymes; Toxins; Fibrinogen; Nephrotoxicity. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992011000400015 |
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Vigerelli,Hugo; Sciani,Juliana Mozer; Jared,Carlos; Antoniazzi,Marta Maria; Caporale,Graciane Maria Medeiros; Silva,Andréa de Cássia Rodrigues da; Pimenta,Daniel C. |
Background Rabies is a fatal zoonotic neglected disease that occurs in more than 150 countries, and kills more than 55.000 people every year. It is caused by an enveloped single stranded RNA virus that affects the central nervous system, through an infection initiated by the muscular nicotinic acetylcholine receptor, according to many authors. Alkaloids, such as acetylcholine, are widespread molecules in nature. They are present in numerous biological fluids, including the skin secretion of many amphibians, in which they act (together with proteins, peptides and steroids) as protection agents against predators and/or microorganisms. Among those amphibians that are rich in alkaloids, there is the genus Rhinella.Methods Bufotenine was isolated from Rhinela... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rabies; Rhinella; Bufotenine; Alkaloids; Toxins; Mass spectrometry. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992014000200336 |
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Baldassi,L.. |
Clostridium is an anaerobic bacterial genus. The clostridia produce more protein toxins than any other bacterial genus and are a rich reservoir of toxins for research and medicinal uses. Clostridia are widely spread in the environment: soil, dust and water, presenting more than 120 described species, although few can cause diseases. Diseases can grossly be divided into neurotropic disorders (nervous system is primarily affected), enterotoxemias (affecting intestinal tract and parenchymatous organs), and gas gangrene (myonecrosis with toxemia). Undoubtedly the most widely recognized infection due to anaerobes was clostridial myonecrosis, but recently interest has arisen for the role of clostridia in intestinal diseases. This report describes the most... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clostridiosis; Clostridium spp; Toxins. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000400002 |
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Pereira,Andreia Vieira; Barros,Gustavo de; Pinto,Erika Gracielle; Tempone,Andre Gustavo; Orsi,Ricardo de Oliveira; Santos,Lucilene Delazari dos; Calvi,Sueli; Ferreira Jr,Rui Seabra; Pimenta,Daniel Carvalho; Barraviera,Benedito. |
Abstract Background Apis mellifera venom, which has already been recommended as an alternative anti-inflammatory treatment, may be also considered an important source of candidate molecules for biotechnological and biomedical uses, such as the treatment of parasitic diseases. Methods Africanized honeybee venom from Apis mellifera was fractionated by RP-C18-HPLC and the obtained melittin was incubated with promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Cytotoxicity to mice peritoneal macrophages was evaluated through mitochondrial oxidative activity. The production of anti- and pro-inflammatory cytokines, NO and H2O2 by macrophages was determined. Results Promastigotes and intracellular amastigotes were susceptible to melittin... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Melittin; Apis mellifera; Leishmania; Leishmaniasis; Peptides; Toxins; Antiparasitic; Cytokines. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992016000100301 |
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Registros recuperados: 33 | |
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