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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Atividades biológicas de peçonhas de vespa (Polistes lanio lanio) e formiga (Paraponera clavata) / Biological activities of wasp (Polistes lanio lanio) and ant (Paraponera clavata)

Silva, Delano Aníbal da 18 August 2018 (has links)
Orientador: Stephen Hyslop / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T04:48:28Z (GMT). No. of bitstreams: 1 Silva_DelanoAnibalda_D.pdf: 1969731 bytes, checksum: de221836aebacda27e28c520b97a53e9 (MD5) Previous issue date: 2011 / Resumo: As peçonhas de himenópteros contêm diversas toxinas que podem causar hemólise, cardiotoxicidade e insuficiência renal, além de reação de hipersensibilidade. Adicionalmente, algumas vespas e formigas utilizam sua peçonha para imobilizar ou matar a presa. Neste estudo analisamos as atividades fosfolipásica (PLA2) e hemolítica bem como a atividade biológica sobre íleo e átrio isolados de rato, e sobre coração semi-isolado de barata, das peçonhas de formiga (Paraponera clavata) e vespa (Polistes lanio lanio). A eletroforese das peçonhas (SDS-PAGE) revelou a presença de componentes com massas moleculares de ~22 kDa a 100 kDa em P. clavata e de 19 a 119 kDa em P. l. lanio. Já a cromatografia por gel filtração resultou em cinco picos principais para a peçonha de P. clavata e seis para a de P. l. lanio. A peçonha de P. clavata possuiu atividades PLA2 e hemolítica moderadas, que foram abolidas pelo aquecimento (100ºC, 20 min). A peçonha de P. clavata (0,1-3 ?g/ml) contraiu íleo isolado de rato, cujo efeito foi dessensibilizante e resistente ao aquecimento da peçonha. Esta atividade contraturante foi localizada no primeiro pico do perfil de eluição da cromatografia por gel filtração. Em átrio isolado de rato a peçonha de P. clavata (0,125-10 ?g/ml) causou contratura, resultando em diminuição da força contrátil e redução na freqüência atrial com aumento na liberação de creatinoquinase-MB (CK-MB) tecidual. O aquecimento da peçonha não aboliu esta ação atrial. A análise histopatológica mostrou necrose dos cardiomiócitos que não foi afetada pelo aquecimento. Dos picos obtidos por gel filtração, o pico 1 reproduziu a contratura causada pela peçonha enquanto o pico 3 aumentou a contratilidade atrial. Em coração semi-isolado de barata, a peçonha de P. clavata (1-100 ?g) causou bradicardia. Conclui-se que a peçonha de P. clavata: (1) possui atividades PLA2 e hemolítica que são termolábeis, (2) causa bradicardia em coração semi-isolado de barata, e (3) provoca contração em íleo isolado e contratura em átrio direito de rato. Ao contrário de P. clavata, a peçonha de P. l. lanio (0,3-100 ?g/ml) mostrou altas atividades PLA2 e hemolítica que também foram abolidas pelo aquecimento (100ºC, 20 min). A peçonha contraiu íleo isolado de rato, e causou inotropismo negativo em átrio direito isolado de rato, sem afetar o cronotropismo; não houve contratura da linha basal. A peçonha causou forte bradicardia em coração semi-isolado de barata que não foi abolido pelo aquecimento (100ºC, 20 min). Este cronotropismo negativo foi mediado por uma fração da peçonha de P. l. lanio enriquecida em componentes de baixa massa molecular (<5 kDa, obtida através da ultrafiltração). A cromatografia desta fração em HPLC de fase reversa resultou em seis picos, dos quais apenas o pico 4 causou bradicardia em coração semi-isolado de barata. A bradicardia foi bloqueada pela glibenclamida, sugerindo o envolvimento de canais de K+ dependentes de ATP neste fenômeno. A análise do pico ativo por espectrometria de massas indicou a presença de peptídeos. Conclui-se que a peçonha de P. l. lanio: (1) tem alta atividade fosfolipásica e hemolítica (ambas termolábeis), (2) provoca contração de íleo e inotropismo negativo em átrio direito de rato e (3) exerce forte cronotropismo negativo em coração semi-isolado de barata mediado pela ativação de canais de potássio dependentes de ATP / Abstract: Hymenoptera venoms contain toxins that can cause hemolysis, renal failure, cardiotoxicity and hypersensitivity in humans. Additionally, some wasps and ants use their venom to immobilize or kill prey. In this study, we analyzed the phospholipase (PLA2) and hemolytic activities of ant (Paraponera clavata) and wasp (Polistes lanio lanio) venoms, and their action on rat isolated ileum and right atrium and cockroach semi-isolated heart. Electrophoresis (SDS-PAGE) showed that the venoms of P. clavata and P. l. lanio contained components with molecular masses of ~20-100 kDa and 19-119 kDa, respectively. Gel filtration chromatography resulted in five major peaks for P. clavata venom and six for P. l. lanio. Paraponera clavata venom had moderate phospholipase and hemolytic activities that were abolished by heating (100ºC, 20 min). This venom (0.1-3 ?g/ml) contracted rat isolated ileum, with a desensitizing effect, and heating the venom did not abolish this activity, which was located in the first peak of the gel filtration elution profile. In isolated atria, the venom (0.125-10 ?g/ml) caused muscle contraction that resulted in decreased contractile force and a reduction in atrial rate, with an increase in creatine kinase-MB (CK-MB) release; this atrial action was not abolished by heating. Histopathological analysis revealed myonecrosis that was also unaffected by heating. Of the peaks obtained by gel filtration, peak 1 reproduced the contraction observed with the venom whereas peak 3 caused a sustained increase in atrial contractility. The venom (1-100 ?g) caused bradycardia in cockroach semi-isolated hearts. These results show that P. clavata venom: (1) has PLA2 and hemolytic activities that are thermolabile, (2) causes bradycardia in cockroach semi-isolated hearts, and (3) contracts rat isolated ileum and causes contracture of rat right atria. In contrast to P. clavata, P. l. lanio venom (0.3-100 ?g/ml) showed high PLA2 and hemolytic activities that were also abolished by heating (100°C, 20 min). Polistes l. lanio venom contracted rat isolated ileum and produced negative inotropism in isolated rat right atria; there was no effect on the chronotropic response or on the baseline tension, i.e., no muscle contracture. The venom caused marked bradycardia in coackroach semi-isolated hearts that was unaffected by heating. This bradycardia was mediated by a low-molecular mass fraction of the venom (<5 kDa, obtained by ultrafiltration). RP-HPLC of this fraction resulted in six peaks, of which only the fourth caused bradycardia in cockroach semi-isolated hearts. This bradycardia was blocked by glibenclamide, suggesting the involvement of ATP-dependent K+ channel activation. Mass spectrometry of the active peak indicated the presence of peptides. These results indicate that P. l. lanio venom: (1) has high PLA2 and hemolytic activities that are thermolabile, (2) contracts rat isolated ileum and reduces the contractile force of isolated right atria, and (3) causes marked bradycardia in cockroach semi-isolated heart via the activation of ATP-dependent K+ channels / Doutorado / Farmacologia / Doutor em Farmacologia
42

Efeitos comportamentais do veneno de Crotalus durissus terrificus e do soro anticrotálico em ratos Wistar / Behavioral effects on Crotalus durissus terrificus venom and crotalid anti-venom in Wistar rats

Diego de Carvalho 14 December 2010 (has links)
Acidentes ofídicos constituem um problema de saúde publica. Estudos prévios indicam que constituintes do veneno de Crotalus durissus terrificus injetados sistemicamente promovem, agudamente, aumento dos níveis de ansiedade em ratos; se injetados topicamente na formação hipocampal, região intimamente ligada a processos de memória espacial e ansiedade, induzem alterações citoestruturais. O objetivo deste trabalho foi avaliar, em ratos, efeitos comportamentais decorrentes da injeção sistêmica de veneno bruto de Crotalus durissus terrificus e a eficácia do soro anticrotálico em prevenir esses prejuízos quando administrado variáveis intervalos de tempo depois do envenenamento. Ratos submetidos a uma única injeção sistêmica de veneno bruto 7 dias antes do inicio dos testes foram avaliados nas tarefas de memória de referencia e de memória operacional no labirinto aquático de Morris, e também a uma tarefa envolvendo uma plataforma visível no mesmo aparelho. A seguir, os animais foram submetidos ao paradigma do teste-reteste no labirinto em cruz elevado. Os resultados mostraram que houve prejuízos de memória de referencia e de memória operacional; este último efeito ocorreu quando o intervalo entre as tentativas foi de 10 minutos, mas não quando foi de zero minutos. Potenciais efeitos sensoriais e motores foram excluídos. Alem disso, houve substancial aumento nos níveis de ansiedade. A administração de soro anti-crotálico preveniu os principais prejuízos de memória desde que realizada em ate 10 horas apos a injeção do veneno (foram testados intervalos de 0, 0,5, 2, 10 e 24 horas, em grupos independentes de animais)..O grupo tratado com soro anti-crotálico 24 horas depois do envenenamento apesar de prejudicado em relação aos grupos controle (um injetado com salina e o outro apenas com soro), exibiu desempenho melhor do que o grupo tratado apenas com veneno. Assim, o presente conjunto de resultados representam a primeira demonstração de que (1) uma única dose sistêmica do veneno crotálico produz prejuízos de memória espacial em ratos e aumenta os níveis de ansiedade avaliados 4 semanas apos a injeção, e (2) os prejuízos de memória podem ser prevenidos pela administração de soro anticrotálico desde que essa administração ocorra em ate 10 horas apos o envenenamento. / Snakebites constitute a serious public health problem in Brazil. Prior studies have shown that systemic injections of venom fractions of Crotalus durissus terrificus produce acute increase in anxiety levels in rats; when injected topically within the hippocampal formation, a brain region underlying processes of spatial memory and anxiety, induce damage. The aims of this study included to investigate, in rats, behavioral effects of a single systemic injection of crude venom on performance of spatial memory tasks and on anxiety, and the efficacy and time course of the antivenom administration to prevent memory disruption. Rats subjected to a single systemic injection of venom 7 days before the beginning of behavioral testing were evaluated in modified versions of the reference and working memory tasks in the water maze, and also to a version of the task in which the platform is visible. Then, the subjects were submitted to the test-retest paradigm in the elevated plus maze. Rats injected with the venom exhibited disruption of performance both in reference and working memory versions of the water maze task; in this latter task, however, disruption occurred when the intertrial interval was 10 minutes but not when the it was zero minutes. Anti-crotalic serum injection prevented memory disruptions when its administration occurred up to 10 hours after injection of the venom (time intervals evaluated included 0, 0.5, 2, 10 and 24 hours, in independent groups of rats). Subjects that received anti-crotalic serum 24 hours after venom injection exhibited disruption of memory relative to control groups (one of them treated with saline and the other with anti-crotalic serum only); however, performance of those animals was better when compared to subjects receiving only venom administration. These results show, to our knowledge for the first time, that (1) a single systemic injection of crotalic venom induces disruption of spatial memory and increases anxiety evaluated 4 weeks after injection, and (2) major spatial memory disruptions may be prevented by administration of the anti-crotalic serum up to 10 hours after the venom injection.
43

Development of an Immunodiagnostic Kit for Species Identification of Snake Bite and Studies on the Cross-Reacting Venom Antigens

De, Anindya Kanti January 1996 (has links) (PDF)
No description available.
44

Evoluce peptidů s antimikrobiální aktivitou v jedu kukaččích včel rodu Nomada (Hymenoptera: Apoidea) / Evolution of peptides with an antimicrobial activity in venom of bees from genus Nomada (Hymenoptera: Apoidea)

Matějková, Zuzana January 2017 (has links)
No description available.
45

Allergen immunotherapy for insect venom allergy: a systematic review and meta-analysis

Dhami, S., Zaman, Hadar, Varga, E.M., Sturm, G.J., Muraro, A., Akdis, C.A., Antolın-Amerigo, D., Bilo, M.B., Bokanovic, D., Calderon, M.A., Cichocka-Jarosz, E., Oude Elberink, J.N.G., Gawlik, R., Jakob, T., Kosnik, M., Lange, J., Mingomataj, E., Mitsias, D.I., Mosbech, H., Ollert, M., Pfaar, O., Pitsios, C., Pravettoni, V., Roberts, G., Rueff, F., Sin, B.A., Asaria, M., Netuveli, G., Sheikh, A. 25 January 2017 (has links)
No / Background The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing the EAACI Guidelines on Allergen Immunotherapy (AIT) for the management of insect venom allergy. To inform this process, we sought to assess the effectiveness, cost‐effectiveness and safety of AIT in the management of insect venom allergy. Methods We undertook a systematic review, which involved searching 15 international biomedical databases for published and unpublished evidence. Studies were independently screened and critically appraised using established instruments. Data were descriptively summarized and, where possible, meta‐analysed. Results Our searches identified a total of 16 950 potentially eligible studies; of which, 17 satisfied our inclusion criteria. The available evidence was limited both in volume and in quality, but suggested that venom immunotherapy (VIT) could substantially reduce the risk of subsequent severe systemic sting reactions (OR = 0.08, 95% CI 0.03–0.26); meta‐analysis showed that it also improved disease‐specific quality of life (risk difference = 1.41, 95% CI 1.04–1.79). Adverse effects were experienced in both the build‐up and maintenance phases, but most were mild with no fatalities being reported. The very limited evidence found on modelling cost‐effectiveness suggested that VIT was likely to be cost‐effective in those at high risk of repeated systemic sting reactions and/or impaired quality of life. Conclusions The limited available evidence suggested that VIT is effective in reducing severe subsequent systemic sting reactions and in improving disease‐specific quality of life. VIT proved to be safe and no fatalities were recorded in the studies included in this review. The cost‐effectiveness of VIT needs to be established. / EAACI and Grant agreement no: 601763.
46

Effects of Red Diamondback Rattlesnake Venom on Keloid Dermal Fibroblasts <i>In Vitro</i>

Newman, Mackenzie Shelby January 2013 (has links)
No description available.
47

INVESTIGATING ICHNEUMONIDAE: INSIGHTS INTO SPECIES IDENTIFICATION AND VENOM COMPOSITION

Pook, Victoria G. 01 January 2016 (has links)
Parasitoid wasps are hyperdiverse, with current estimates suggesting that they may account for up to 20% of all insect species. Though their ecological significance and their importance in integrated pest management cannot be denied, these taxa remain understudied and, due to their small size, are often overlooked. However, recent advances in molecular techniques are helping to reverse this trend by providing tools which scientists can use to better understand species limits and host interactions. Parasitoid wasps are often morphologically cryptic and their accurate delimitation requires the analysis of DNA sequence data from fast-evolving genes in addition to morphological characters. The research presented here demonstrates the utility of a new molecular locus in species delimitation. Also, a morphological key to the species of a genus occurring in America, north of Mexico is presented. The interactions between parasitoid wasps and their hosts are highly complex. On the wasp side, it involves the production venom, which likely contains bountiful natural resources. In this study, the venom proteins of wasps of the genus Megarhyssa (Hymenoptera: Ichneumonidae) are identified. Putative functions are assigned to these proteins and possible applications are discussed. One of the proteins identified is the enzyme, laccase, which is associated with the degradation and digestion of wood. The sequence of the gene coding for this laccase was analyzed and used to create recombinant proteins in a baculovirus-insect cell expression system. Future work investigating this enzyme is necessary to determine its activity against the plant cell wall. The research presented here provides insight into the identification and venom composition of ichneumonid wasps. The results contribute to our knowledge of this understudied taxon and indicate that there is much to be gained from further research in this field which will become increasingly practicable as molecular techniques advance and become more affordable.
48

A homoeopathic drug proving of Hemachatus haemachatus with a subsequent comparison of this remedy to those remedies yielding the highest numerical value and total number of rubrics on repertorisation of the proving symptoms

Cahill, Jodi January 2008 (has links)
Thesis (M.Tech.: Homoeopathy)--Durban University of Technology, 2008 / The proving substance Hemachatus haemachatus commonly known as the Rinkhals belongs to the family of Elapidae. This spitting-cobra is a local snake found only in Southern Africa. This proving tested the effects of the thirtieth centesimal (30CH) potency of venom from Hemachatus haemachatus on healthy provers. OBJECTIVES It was hypothesised that Hemachatus haemachatus 30CH would produce clearly observable signs and symptoms in healthy provers, and that the comparison of Hemachatus haemachatus to those yielding the highest numerical value and total number of rubrics on repertorisation of the proving symptoms would highlight differences and similarities between the remedy symptoms so that confusion as to the indication is eliminated. It was hypothesised that a fuller understanding of Hemachatus haemachatus and its relationship to other remedies would be gained following this comparison. METHODOLOGY A double blind, placebo controlled proving of Hemachatus haemachatus 30CH was conducted on thirty healthy volunteers who met the inclusion criteria. Six of these thirty provers randomly received placebo, with neither prover nor researcher knowing whom received placebo. Provers had a homoeopathic case history taken and a physical examination performed on them prior to commencement of the proving. The provers recorded their signs and symptoms 6 by means of a journal before, during and after administration of the remedy. On completion of the proving, the information obtained was correlated and assessed by the two researchers, De la Rouviere and Cahill. The symptoms elicited during the proving were translated into materia medica and repertory language, and a homoeopathic picture of the remedy was subsequently formulated. Data from the case histories, physical examinations and group discussions were also considered in the assessment. RESULTS During the period of investigation, provers experienced a variety of symptoms on the mental, emotional and physical spheres. On the mental emotional sphere there was a marked degree of irritability and changeability in moods as is commonly seen in many of the snake remedies. Along with this, it was noted that there were feelings of anxiety for reasons unknown, a sense of having lost something or someone close, and a desire to be left alone. There were also a great number of feelings regarding the home, where there were feelings of the home being a place of safety and wanting order in the home. On a physical level, many of the provers noted varying degrees of abdominal discomfort and headaches. Along with anxiety, provers experienced palpitations and sensations of chest restriction or constriction with shortness of breath. There were a variety of musculoskeletal symptoms ranging from painful joints in the fingers to stiffness and tightness in the neck and back. Provers noted flushes of heat and alterations of their internal thermostat. Provers experienced marked dryness of the mucus membranes and the skin, and there was also a general feeling of weakness and heaviness as well as a marked aggravation in the mornings on waking. 7 CONCLUSIONS Symptoms obtained from the proving of Hemachatus haemachatus 30CH were studied and evaluated. Those symptoms that appeared to represent the remedy picture of Hemachatus haemachatus most accurately in the researchers‟ opinion were used in the repertorisation of the remedy. The investigation supported the hypothesis that Hemachatus haemachatus 30CH would produce clearly observable signs and symptoms in healthy provers. The subsequent comparison of the proving symptoms of Hemachatus haemachatus to Lycopodium (Club moss), Sulphur, Alumina (Aluminium oxide), Sepia (Cuttle fish) and Calcarea carbonica (Carbonate of Lime) highlighted differences and similarities between these remedies and Hemachatus haemachatus. The further comparison of remedies that came up on repertorisation restricted to the plant, mineral and animal kingdoms respectively provided a further comparison of remedies, which aimed at enhancing the differentiation of Hemachatus haemachatus to other similar remedies. / M
49

Venom Variability and Health Severity Outcomes of the Mohave rattlesnake (Crotalus scutulatus scutulatus) from Southern Arizona

Curtis, Ryan, Richards, Kelvin, Boesen, Keith January 2012 (has links)
Class of 2012 Abstract / Specific Aims: Determine the difference in venom potency among Mohave Rattlesnakes in Cochise in Pima Counties and determine if those differences correlate to changes in clinical outcomes. Methods: Twenty-one Mohave rattlesnakes, C. s. scutulatus were collected from Arizona and New Mexico. Venom proteomes were analyzed using RP-HPLC and SDS-PAGE. The toxicity of venoms was analyzed using LD50. Health severity outcomes between two Arizona counties, Pima and Cochise, were determined by retrospective chart review of the Arizona Poison and Drug Information Center database between 2002-2009. Main Results: Six phenotypes were identified based on three venom proteins; Mojave toxin, SVMP PI and PIII, and myotoxin. Venom changed geographically from SVMP-rich to Mojave toxin-rich phenotypes from south central to southeastern Arizona. Phenotypes containing myotoxins were only found in the transitional zone between the SVMP and Mojave toxin phenotypes. Venom samples containing the largest amounts of SVMP or Mojave toxin had highest and lowest LD50s, respectively. Conclusions: There was a significant difference when comparing the presence of CNS affects between Pima and Cochise counties (p = 0.001). No significant difference was found when comparing severity number of antivenom vials administered, days spent in a health care facility or envenomation per 100,000 population. Although not part of the original data to be collected, death and intubations, were also noted. There is a 10x and 50x increased risk of death or intubations if envenomated in Cochise County.
50

Peçonha da cascavel Crotalus durissus terrificus prejudica a memória espacial e induz a morte neuronal no hipocampo, em ratos: estudos &#39; in vivo&#39; e &#39; in vitro&#39; / Crotalus durissus terrificus venom impairs spatial memory and induces neuronal death in rat hippocampus: \'in vivo\' and \'in vitro\' studies

Carvalho, Diego de 25 February 2015 (has links)
A administração sistêmica da peçonha bruta da cascavel Sul-Americana (Crotalus durissus terrificus, Cdt) induz prejuízos de memória espacial em ratos, sugerindo a ocorrência de dano hipocampal. No presente estudo, foram utilizadas técnicas In vivo e In vitro, a fim de testar os potenciais efeitos centrais do veneno de Cdt e da crotoxina (CTX), principal neurotoxina componente da peçonha bruta da serpente. Foram investigados (1) efeitos comportamentais da administração sistêmica e intrahipocampal do veneno de Cdt e da CTX envolvendo diferentes versões do labirinto aquático de Morris; (2) a morte neuronal, o curso temporal e a ação protetora do soro anticrotálico à exposição de culturas organotípicas de hipocampo a doses crescentes (0,05-1 &mu;g/mL) do veneno bruto de Cdt e de CTX, por meio da coloração fluorescente por Iodeto de propídeo (PI) (que reflete a morte neuronal); e (3) alguns dos possíveis mecanismos fisiopatológicos do envenenamento experimental em culturas de hipocampo utilizando o antagonista de receptores AMPA de glutamato, NBQX, à administração de 0,05 &mu;g/mL do veneno bruto de Cdt, para avaliar a possível participação do glutamato e seus receptores na morte neuronal. A administração sistêmica e intrahipocampal do veneno bruto de cascavel em ratos promoveu marcados prejuízos de memória espacial de referência e operacional. Diferentemente, a CTX promoveu prejuízos comportamentais apenas quando a administração foi intrahipocampal. As culturas expostas ao veneno bruto apresentaram dano sobretudo nas células piramidais de CA1, enquanto as culturas incubadas com CTX não apresentaram danos. Essa seletividade em relação ao CA1 foi mais proeminente nas doses baixas. O soro anticrotálico preveniu a morte neuronal quando administrado até uma hora após a exposição do veneno. O NBQX preveniu parcialmente o dano em CA1 indicando a participação de receptores AMPA de glutamato na cascata de eventos que subjazem os danos a estas células causados pela peçonha bruta de Cdt. Estes achados podem contribuir para a tanto para elucidação dos mecanismos quanto para a conduta utilizada durante o envenenamento crotálico / Systemic administration of the South American rattlesnake (Crotalus durissus terrificus, Cdt) venom in rats permanently disrupts performance in hippocampus-dependent spatial memory tasks, thus indicating the occurrence of damage to this brain area. In vivo and In vitro approaches were employed in the present study to investigate the effects of the venom and its main compound, crotoxin (CTX). We investigated (1) behavioral effects after both systemic and intrahipocampal administration of either venom or CTX in rats on performance in different versions of the Morris\' water maze task; (2) neuronal death, evaluated by the intensity of propidium iodide (PI) fluorescence (neurotoxicity of the venom and of CTX, and the protection by the antivenom, on organotypic hippocampal slice cultures, were evaluated by comparing slices exposed to venom and (1) slices treated only with vehicle - negative control - and (2) slices incubated with 1 mM glutamate - positive control for maximal neuronal death), and the time course of neurotoxic effects of 0.05-1 &mu;g/mL of crude Cdt venom and CTX, and the Brazilian anticrotalid serum on organotypic hippocampal slice cultures; and (3) provide an initial screening of the mechanisms underlying the venom action on cultured hippocampal slices, using the AMPA receptor antagonist NBQX and the crude venom at 0.5 &mu;g/mL dose, to test whether the neuronal damage is mediated by glutamate following the experimental envenomation. Both systemic and intrahippocampal administration of Cdt venom induces permanent disruption of spatial reference memory and spatial working memory in rats. In contrast, CTX only promoted behavioral effects when administered intrahippocampally. Slices exposed to Cdt venom, but not to CTX, exhibited substantial neuronal damage. This effect was particularly prominent in the CA1 sub-field at lower concentrations of the venom. The antivenom prevented damage when applied until 1 hour after the exposure of the venom. The NBQX partially prevented damage to CA1, thus indicating that AMPA receptors play a role in the damage caused by the Cdt venom. These findings may be helpful in the elucidation and management of rattlesnake envenomation

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