Made available in DSpace on 2016-07-18T17:53:07Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 176084 bytes, checksum: ba3ed3d023a44786d6afb86a343a98e0 (MD5) Previous issue date: 2010-08-27 / Accidents ofidic cart a relevant medical problem in our country due to the high toxicity and lethality of the poisons. About 8% of the accidents they are related to the gender Crotalus being in second place in the number of accidents and in first in relation to the death index. The study had as objective evaluates and to compare the effectiveness of the therapy of the intoxication for poison crotalic in dogs, with use of antiophidic serum isolated or associated the frozen plasma. The dogs were divided in two groups being: Group VS: animals inoculated with poison crotalic and treaties with antiophidic serum bothropic-crotalic; Group VSP: animals inoculated with poison crotalic, treaties with antiophidic serum and plasma frozen fresh. The animals were submitted the clinical evaluation and laboratorial. It was observed us of the two groups edema in the place of inoculation of the poison and mitigation with more precocious recovery in the animals of the group VSP, presence of reflex pupillary the light, dilated pupils, lameness, flaccid paralysis of the musculature, mandibular ptose, increase of the breathing frequency, decrease in the erythrocyte number, hemoglobin and hematocrit, decrease in the number of lymphocytes, increase in the neutrophil number, leukocytes, sanguine incoagulability and increase in the time of protrombina and partial tromboplastina activated with more precocious recovery in the animals of the group VSP. In conclusion the dose of poison crotalic used in the experimental intoxication of dogs was capable to produce alterations in the clinical parameters, laboratorial and hematological with benefits mainly in the recovery of the mitigation and decrease of the member edema in the animals that received the antiophidic serum associated to the frozen fresh plasma when compared to the animals that received only the antiophidic serum. / Acidentes ofídicos acarretam um problema médico relevante em nosso país devido às altas toxicidades e letalidades dos venenos. Cerca de 8% dos acidentes estão relacionados ao gênero Crotalus estando em segundo lugar no número de acidentes e em primeiro em relação ao índice de óbito. O estudo teve como objetivo avaliar e comparar a indução da intoxicação experimental e terapia por veneno crotálico em cães, com uso de soro antiofídico isolado ou associado a plasma congelado. Os cães foram divididos em dois grupos sendo: Grupo VS: animais inoculados com veneno crotálico e tratados com soro antiofídico botrópico-crotalico; Grupo VSP: animais inoculados com veneno crotálico, tratados com soro antiofídico e plasma fresco congelado. Os animais foram submetidos à avaliação clínica e hemograma. Foram observados nos dois grupos, edema no local de inoculação do veneno e sedação com recuperação mais precoce nos animais do grupo VSP, presença de reflexo pupilar a luz, midríase, claudicação, paralisia flácida da musculatura, ptose mandibular, aumento da frequência respiratória, diminuição no número de eritrócitos, hemoglobina e hematócrito, diminuição no número de linfócitos, aumento no número de neutrófilos, leucócitos, incoagulabilidade sanguínea e aumento no tempo de protrombina e tromboplastina parcial ativada com recuperação mais precoce nos animais do grupo VSP. Conclui-se que a dose de veneno crotálico usada na intoxicação experimental de cães foi suficiente de produzir alterações nos parâmetros clínicos, laboratoriais com benefícios principalmente na recuperação da sedação e diminuição do edema de membro nos animais que receberam o soro antiofídico associado ao plasma fresco congelado quando comparado aos que receberam somente o soro antiofídico.

Submitted by Adriana Martinez (amartinez@unoeste.br) on 2018-05-10T22:40:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Isabella Saneshigue.pdf: 688383 bytes, checksum: dcc746f15532dd8ee811a23185cc4201 (MD5) / Made available in DSpace on 2018-05-10T22:40:35Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Isabella Saneshigue.pdf: 688383 bytes, checksum: dcc746f15532dd8ee811a23185cc4201 (MD5) Previous issue date: 2017-11-24 / Accidents caused by venom of Crotalus snakes, popularly known in Brazil as rattlesnake, cause the highest number of deaths in humans and animals, mainly due to the great neurotoxic, myotoxic, coagulant, nephrotoxic and hepatotoxic potential of their venom. The present study had the objective of analyzing by histology and fractal dimension liver samples of Wistar rats experimentally poisoned with venom of the snake Crotalus durissus terrificus. The hypothesis is that the venom of Crotalus durissus terrificus is capable of inducing hepatic damage at the dose recommended in this study, that its alterations can be quantified by the fractal dimension and that the antiofidic serum be able to minimize the hepatic lesions induced by the venom. Ninety rats were divided into different groups and treated with: control group (GC, n = 30) 0.9% sodium chloride solution; venom group (GV, n = 30) crotalic venom; (GVS, n = 30) Crotalic venom and antiofidic serum 6 hours after the application of the venom. Liver samples were collected at 2h (M1), 8h (M2) and 24h (M3) after venom administration and submitted to histological analysis and fractal dimension (DF) using the ImageJ® software and box-counting method. Procedures for collecting, processing and analyzing samples were standardized. No significant lesions were observed in GC and GV. Necrosis, cytoplasmic and nuclear vacuolization and absence of inflammatory infiltrate were observed in M2 and M3, whereas in GVS, mononuclear inflammatory infiltrate was evident at all times, in addition to the lesions found in GV. The lesions of necrosis, cytoplasmic and nuclear vacuolization, considered of greater severity were visualized in M3 in both GV and GVS. There was an increase in DF for the same changes in GV and GVS over time, but with no difference between them, but with a significant difference compared to CG. The lesions evidenced in the liver were not minimized by the application of the antiofidic serum. This study agrees with other authors about the hepatotoxicity of crotalic venom in relation to histological findings and the results indicate an increase in FD for the findings of vacuolization and necrosis, proving to be an efficient method for the quantitative evaluation of morphological changes induced by venom without observer interference. In addition, non-protection of the liver by antiofidic serum was evident. It is concluded that Crotalus durissus terrificus venom has hepatotoxic effects; FD is effective in the quantitative morphological evaluation of the liver for vacuolization and necrosis, and antiofidic serum did not protect the liver from venom-induced lesions. / Os acidentes causados pelo veneno das serpentes do gênero Crotalus, conhecidas popularmente no Brasil como cascavel, causam o maior índice de óbitos em seres humanos e animais, principalmente pelo grande potencial neurotóxico, miotóxico, coagulante, nefrotóxico e hepatotóxico do seu veneno. O presente estudo teve por objetivo analisar pela a dimensão fractal e achados histológicos em amostras de fígado de ratos Wistar intoxicados experimentalmente com veneno da serpente Crotalus durissus terrificus. A hipótese é que o veneno da Crotalus durissus terrificus seja capaz de induzir lesão hepática na dose preconizada neste estudo, que suas alterações possam ser quantificadas pela dimensão fractal e que o soro antiofídico seja capaz de minimizar as lesões hepáticas induzidas pelo veneno. Noventa ratos, foram distribuídos em diferentes grupos e tratados com: grupo controle (GC, n=30) solução de cloreto de sódio 0,9%; grupo veneno (GV, n=30) veneno crotálico; grupo veneno/soro antiofídico (GVS, n=30) veneno crotálico e soro antiofídico 6 horas após aplicação do veneno. As amostras do fígado foram realizadas nos momentos 2h (M1), 8h (M2) e 24h (M3) após administração do veneno e submetidas a análise histológica e dimensão fractal (DF) utilizou o software ImageJ® e método de box-counting. Os procedimentos para coletar, processar e analisar as amostras foram padronizados. Não foram observadas lesões significativas no GC e no GV foram evidenciadas necrose, vacuolização citoplasmática e nuclear e ausência de infiltrado inflamatório nos M2 e M3, enquanto que no GVS evidenciou-se infiltrado inflamatório mononuclear em todos os momentos, além das lesões constatadas no GV. As lesões de necrose, vacuolização citoplasmática e nuclear, consideradas de maior severidade foram visualizadas no M3 tanto no GV quanto no GVS. Observou-se uma elevação da DF para as mesmas alterações nos GV e GVS ao longo do tempo, porém sem diferença entre eles, mas com diferença significativa comparado ao GC. As lesões evidenciadas em fígado não foram minimizadas pela aplicação do soro antiofídico. Este estudo concorda com outros autores quanto a hepatotoxicidade do veneno crotálico frente aos achados histológicos e os resultados apontam aumento da DF para os achados de vacuolização e necrose, mostrando ser um método eficaz na avaliação quantitativa de alterações morfológicas induzidas pelo veneno, sem a interferência do observador. Além disso, a não proteção do fígado pelo soro antiofídico foi evidente. Conclui-se que o veneno de Crotalus durissus terrificus apresenta efeitos hepatotóxicos; a DF é eficaz na avaliação morfológica quantitativa do fígado para vacuolização e necrose, e o soro antiofídico não protegeu o fígado de lesões induzidas pelo veneno.

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Made available in DSpace on 2016-01-26T18:55:33Z (GMT). No. of bitstreams: 1 Cristiane de Pauli Pereira.pdf: 1503472 bytes, checksum: 59921819ab10ff8a49c25d968609430f (MD5) Previous issue date: 2012-03-20 / This study evaluated the effects of the venom from Crotalus durissus terrificus and snakebite serum on the clinical signs and liver function in 120 Wistar rats by performing physical examinations, laboratory and histopathology tests. The animals were divided into four experimental groups of thirty animals in each group. The control group (C) - received only solution of sodium chloride 0.9%; Group venom (V) - received 1mg/kg venom; Group snakebite serum (S) - received the indicated dose snakebite serum to neutralize the poison; Poison and serum group (VS) - received venom and the snakebite serum six hours later. The clinical evaluation and specimen obtained for laboratory and histological examinations were performed at time 2 hours, 8 hours and 24 hours in all groups. It was observed for the S Group elevation of serum enzyme alkaline phosphatase (FA), inflammatory reaction, changes in Kupffer cells, necrosis and hyaline degeneration; Group V heart rate decrease over time, increase in rectal temperature (TR), increased FA, increase of serum aspartate aminotransferase (AST), inflammatory infiltrate, changes in Kupffer cells, necrosis and hyaline degeneration; Group VS increased TR and also respiratory rate, elevated serum FA, AST and alanine aminotransferase (ALT), inflammatory reaction, changes in Kupffer cells, necrosis and hyaline degeneration. The results indicate that the venom and snakebite serum alter the clinical parameters and cause liver damage at the doses and times studied. However, further studies with the venom and antivenom to be able to understand the effect of time and changes in the percentage contribution of hepatotoxicity in serum isolated. In addition, to investigate the need for additional treatments to protect the liver. / Este estudo avaliou os efeitos hepatotóxicos do veneno de Crotalus durissus terrificus e soro antiofídico em 120 ratos Wistar, através da realização de exames físico, laboratorial e histopatológico. Os animais foram divididos em quatro grupos experimentais, com trinta animais em cada grupo, sendo: grupo controle (C) - recebeu solução de cloreto de sódio 0,9%; grupo veneno (V) - recebeu veneno crotálico 1mg/Kg; grupo soro antiofídico (S) - recebeu soro antiofídico na dose indicada para neutralizar o veneno; grupo veneno e soro (VS) - recebeu veneno crotálico e após 6 horas o soro antiofídico. A avaliação clínica e a colheita de material para exames laboratorial e histopatológico do fígado foram realizadas nos momentos 2 horas (n=10), 8 horas (n=10) e 24 horas (n=10) para todos os grupos. Observou-se para o grupo S elevação sérica da enzima fosfatase alcalina (FA), infiltrado inflamatório, alterações nas células de Kupffer, necrose e degeneração de hialina; Grupo V diminuição da frequência cardíaca no decorrer do tempo, aumento na temperatura retal (TR), elevação da FA, elevação sérica da aspartato aminotransferase (AST), infiltrado inflamatório, alterações nas células de Kupffer, necrose e degeneração de hialina; Grupo VS aumento da TR e na frequência respiratória, elevação sérica da FA, elevação sérica da AST, elevação sérica da alanina aminotransferase (ALT), infiltrado inflamatório, alterações nas células de Kupffer, necrose e degeneração de hialina. Os resultados encontrados indicam que o veneno crotálico e o soro antiofídico, associados ou não, alteram os parâmetros clínicos e provocam danos hepáticos nas doses e momentos estudados. No entanto, são necessários novos estudos com o veneno crotálico e a soroterapia para que se possa entender o efeito do tempo nas alterações e a porcentagem de contribuição do soro isolado na hepatotoxicidade. Além disso, investigar a necessidade de tratamentos complementares para a proteção hepática.

Made available in DSpace on 2016-07-18T17:53:09Z (GMT). No. of bitstreams: 1 Cristiane de Pauli Pereira.pdf: 1503472 bytes, checksum: 59921819ab10ff8a49c25d968609430f (MD5) Previous issue date: 2012-03-20 / This study evaluated the effects of the venom from Crotalus durissus terrificus and snakebite serum on the clinical signs and liver function in 120 Wistar rats by performing physical examinations, laboratory and histopathology tests. The animals were divided into four experimental groups of thirty animals in each group. The control group (C) - received only solution of sodium chloride 0.9%; Group venom (V) - received 1mg/kg venom; Group snakebite serum (S) - received the indicated dose snakebite serum to neutralize the poison; Poison and serum group (VS) - received venom and the snakebite serum six hours later. The clinical evaluation and specimen obtained for laboratory and histological examinations were performed at time 2 hours, 8 hours and 24 hours in all groups. It was observed for the S Group elevation of serum enzyme alkaline phosphatase (FA), inflammatory reaction, changes in Kupffer cells, necrosis and hyaline degeneration; Group V heart rate decrease over time, increase in rectal temperature (TR), increased FA, increase of serum aspartate aminotransferase (AST), inflammatory infiltrate, changes in Kupffer cells, necrosis and hyaline degeneration; Group VS increased TR and also respiratory rate, elevated serum FA, AST and alanine aminotransferase (ALT), inflammatory reaction, changes in Kupffer cells, necrosis and hyaline degeneration. The results indicate that the venom and snakebite serum alter the clinical parameters and cause liver damage at the doses and times studied. However, further studies with the venom and antivenom to be able to understand the effect of time and changes in the percentage contribution of hepatotoxicity in serum isolated. In addition, to investigate the need for additional treatments to protect the liver. / Este estudo avaliou os efeitos hepatotóxicos do veneno de Crotalus durissus terrificus e soro antiofídico em 120 ratos Wistar, através da realização de exames físico, laboratorial e histopatológico. Os animais foram divididos em quatro grupos experimentais, com trinta animais em cada grupo, sendo: grupo controle (C) - recebeu solução de cloreto de sódio 0,9%; grupo veneno (V) - recebeu veneno crotálico 1mg/Kg; grupo soro antiofídico (S) - recebeu soro antiofídico na dose indicada para neutralizar o veneno; grupo veneno e soro (VS) - recebeu veneno crotálico e após 6 horas o soro antiofídico. A avaliação clínica e a colheita de material para exames laboratorial e histopatológico do fígado foram realizadas nos momentos 2 horas (n=10), 8 horas (n=10) e 24 horas (n=10) para todos os grupos. Observou-se para o grupo S elevação sérica da enzima fosfatase alcalina (FA), infiltrado inflamatório, alterações nas células de Kupffer, necrose e degeneração de hialina; Grupo V diminuição da frequência cardíaca no decorrer do tempo, aumento na temperatura retal (TR), elevação da FA, elevação sérica da aspartato aminotransferase (AST), infiltrado inflamatório, alterações nas células de Kupffer, necrose e degeneração de hialina; Grupo VS aumento da TR e na frequência respiratória, elevação sérica da FA, elevação sérica da AST, elevação sérica da alanina aminotransferase (ALT), infiltrado inflamatório, alterações nas células de Kupffer, necrose e degeneração de hialina. Os resultados encontrados indicam que o veneno crotálico e o soro antiofídico, associados ou não, alteram os parâmetros clínicos e provocam danos hepáticos nas doses e momentos estudados. No entanto, são necessários novos estudos com o veneno crotálico e a soroterapia para que se possa entender o efeito do tempo nas alterações e a porcentagem de contribuição do soro isolado na hepatotoxicidade. Além disso, investigar a necessidade de tratamentos complementares para a proteção hepática.

Ecosystems transition quickly in the Anthropocene, whereas biodiversity adapts more slowly. Here we simulated a shifting woodland ecosystem on the Colorado Plateau of western North America by using as its proxy over space and time the fundamental niche of the Arizona black rattlesnake (Crotalus cerberus). We found an expansive (= end-of-Pleistocene) range that contracted sharply (= present), but is blocked topographically by Grand Canyon/Colorado River as it shifts predictably northwestward under moderate climate change (= 2080). Vulnerability to contemporary wildfire was quantified from available records, with forested area reduced more than 27% over 13 years. Both 'ecosystem metrics' underscore how climate and wildfire are rapidly converting the Plateau ecosystem into novel habitat. To gauge potential effects on C. cerberus, we derived a series of relevant 'conservation metrics' (i.e. genetic variability, dispersal capacity, effective population size) by sequencing 118 individuals across 846 bp of mitochondrial (mt)DNA-ATPase8/6. We identified five significantly different clades (net sequence divergence = 2.2%) isolated by drainage/topography, with low dispersal (F-ST = 0.82) and small sizes (2N(ef) = 5.2). Our compiled metrics (i.e. small-populations, topographic-isolation, low-dispersal versus conserved-niche, vulnerable-ecosystem, dispersal barriers) underscore the susceptibility of this woodland specialist to a climate and wildfire tandem. We offer adaptive management scenarios that may counterbalance these metrics and avoid the extirpation of this and other highly specialized, relictual woodland clades.

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.

O gênero Crotalus pertence a família Viperidae e é popularmente conhecido como cascavél. Seu veneno é reconhecido como fonte biológica de moléculas capaz de produzir danos irreversíveis na saúde dos seres humanos. O presente trabalho foi desenvolvido com a finalidade de estudar os mitos e as crenças, o perfil epidemiológico e toxicológico do veneno das serpentes do gênero Crotalus, para o estado do Tocantins. Para isso, foi realizado levantamento bibliográfico para avaliar os mitos e as crenças que cercam esses animais. Os agravos por serpentes do gênero Crotalus durissus foram obtidos da plataforma TabWin- SINAN, dos registros disponibilizados para os últimos cinco anos – 2012 a 2016, com informações sobre sexo, idade, soroterapia, evolução do caso e município de ocorrência. Também foi analisada a precipitação pluviométrica e temperatura, para avaliar variáveis facilitadoras do encontro com esses animais. O veneno obtido de cascavéis Crotalus durissus collilineatus foi obtido de espécimes coletadas no Tocantins, para análise do seu perfil tóxico. Foram realizados ensaios proteicos, determinada atividade fosfolipásica, dose mínima coagulante, verificada a toxicidade (DL50) e o potencial anti-ofídico do extrato da planta Chiococca alba. Todos os ensaios foram conduzidos em paralelo com o veneno referência, cedido pelo Instituto Butantan – SP, da mesma espécie de serpente em estudo. Diante dos resultados foi possível avaliar que as crenças e os mitos sobre serpentes precisam ser desmistificados, para que, o medo possa ser minimizado e substituído pelo respeito a estes animais. Quanto ao aumento dos acidentes crotálicos no estado, deve-se considerar o alto grau de letalidade para a região norte do país, sendo a sazonalidade um importante fator que influencia nesses índices. Para o veneno de Crotalus durissus collilineatus os experimentos demonstraram ausência de crotamina para nos animais coletados no Tocantins, e a indicação de atividade antiofídica para o estrato da planta Chiococca alba. / The genus Crotalus belongs to the family Viperidae and is popularly known as rattlesnake. Its venom is recognized as a biological source of molecules capable of producing irreversible damage to human health. The present work was developed with the purpose of studying the myths and beliefs, the epidemiological and toxicological profile of venom of snakes of the genus Crotalus, to the state of Tocantins. For this, a bibliographic survey was conducted to evaluate the myths and beliefs surrounding these animals. Crotalus durissus snake complaints were obtained from the TabWin-SINAN platform, from the records available for the last five years - 2012 to 2016, with information on sex, age, serum therapy, case evolution and municipality of occurrence. Rainfall and temperature were also analyzed to evaluate variables that facilitated the encounter with these animals. The venom obtained from rattlesnakes Crotalus durissus collilineatus was obtained from specimens collected in Tocantins, to analyze its toxic profile. Protein assays, phospholipase activity, minimal coagulant dose, toxicity (LD50) and anti-odor potential of the extract of the Chiococca alba plant were performed. All the tests were conducted in parallel with the reference venom, provided by the Butantan Institute - SP, of the same snake species under study. In view of the results it was possible to evaluate that the beliefs and myths about snakes need to be demystified, so that fear can be minimized and replaced by respect for these animals. As for the increase in crotalic accidents in the state, the high degree of lethality for the northern region of the country should be considered, with seasonality being an important factor that influences these indices, the highest incidence occurring on colder days and with higher rainfall. For the venom of Crotalus durissus collilineatus, the experiments demonstrated the absence of crotamine in the animals collected in Tocantins and the indication of antiofidic activity for the stratum of the Chiococca alba plant.

Made available in DSpace on 2016-04-28T20:16:24Z (GMT). No. of bitstreams: 1 2007- Flavio Augusto Soares Graca01.pdf: 782491 bytes, checksum: aca3b139eb03d06af06c5dd1c95ec3d7 (MD5) Previous issue date: 2007-04-26 / Crotalus poisoning was experimentally reproduced by inoculation of Crotalus durissus terrificus (South American Rattlesnake) venom by subcutaneous via in ten clinically healthy mixed breed bovine, weighing between 125 and 449 kg and aged 12 to 36 months. Two bovine of the same age range and breed standard were used as controls. The bovine that received a 0.03 mg/kg p.v. dose died 7h40min after inoculation. A 0.015 mg/kg p.v. dose provoked death in four out of seven inoculated bovine, while two bovine experimentally poisoned with 0.0075 mg/kg p.v. became mildly sick and recovered. Onset of symptoms occurred between 1h30min and 13h45min after inoculation. Evolution oscillated between 5h25min and 44h59min for bovine deaths and between 33h15min and 17 days for bovine that recovered. The principal nervous signs observed were diminished response to external stimuli, hypotonic reflexes, dragging of hooves along the ground, apparent lethargy, difficulties in moving around obstacles, ocular globe paralysis, lateral and sternal decubitus and tongue paralysis. Constant adypsia and petechiae in the conjunctival and vaginal mucosa was also verified. A discrete to moderate increase in bleeding time was verified in six bovine and a moderate increase in partial thromboplastin time was activated in seven bovine. Moderate leukocytosis with neutrophilia, relative lymphopenia, eosinopenia and monocytosis occurred and a discrete increase in the number of rods. A significant increase in creatine kinase serum levels was observed, of a ten-fold order. No significant alterations were observed at urinalysis. At necropsy there were minimal edema at the inoculation site, discrete petechiae and suffusions in the epicardium, omentum, biliary vesicle and bladder mucosa. Histopathological examination revealed necrosis (hyalinization) of groups or isolated myocytes in ten different muscles examined, both close and distant from the inoculation site. Faced with the clinic-pathological picture, observations were made regarding the diagnosis of crotalus envenomation and its differentiation from deseases which course with paralysis and muscular necrosis in cattle in Brazil. / Reproduziu-se experimentalmente o envenenamento crot?lico, atrav?s da inocula??o, por via subcut?nea, do veneno de Crotalus durissus terrificus (Cascavel sul-americana) em dez bovinos mesti?os, com peso variando entre os 125 e 449 quilogramas e idade entre 12 e 36 meses. Dois animais na mesma faixa et?ria e padr?o racial foram utilizados como controle. O animal que recebeu dose de 0,03 mg/kg p.v. foi a ?bito 7h40min ap?s a inocula??o. A dose de 0,015 mg/kg p.v. induziu o ?bito em quatro de sete bovinos inoculados, enquanto os dois animais que receberam 0,0075 mg/Kg, adoeceram discretamente e se recuperaram. Os sintomas tiveram in?cio entre 1h30min e 13h45min ap?s a inocula??o. A evolu??o oscilou entre 5h25min e 44h59min para os animais que morreram e entre 33h15min e 17 dias entre os animais que se recuperaram. Os principais sinais nervosos observados foram diminui??o da resposta aos est?mulos externos, reflexos hipot?nicos, arrastar dos cascos no solo, aparente letargia, paralisia do globo ocular e da l?ngua, dec?bito esternal e lateral. Verificou-se tamb?m adipsia constante e pet?quias nas mucosas vaginal e conjuntival. Observaram-se discreto a moderado aumento do tempo de sangramento em seis animais e moderado aumento do tempo de tromboplastina parcial ativada em sete bovinos. Houve moderada leucocitose com neutrofilia, linfopenia relativa, eosinopenia, monocitose e discreto aumento do n?mero de bast?es. Foi evidenciado significativo aumento dos n?veis s?ricos de creatinaquinase, da ordem de dez vezes. N?o foram observadas altera??es significativas atrav?s da urin?lise. ? necropsia constataram-se edema quase impercept?vel no local da inocula??o, discretas pet?quias e sufus?es no epic?rdio, omento, ves?cula biliar e mucosa da bexiga. Os exames histopatol?gicos revelaram necrose (hialiniza??o) de grupos de mi?citos ou em mi?citos isolados em dez diferentes m?sculos esquel?ticos examinados, pr?ximos ou distantes do local de inocula??o. Diante do quadro cl?nico-patol?gico foram feitas observa??es sobre o diagn?stico do envenenamento crot?lico e sua diferencia??o com enfermidades que cursam com paralisia e necrose muscular em bovinos do Brasil.

The sidewinder rattlesnake is found only in the low hot deserts of the southwestern United States and northwestern Mexico. It has adapted to this environment in various ways and thus is able to live under extremely demanding conditions. Previously published information on sidewinders is quite complete in certain respects and totally lacking in others. The present study represents an attempt to integrate the various aspects of sidewinder biology into a more cohesive unit. A large sidewinder population at Kelso Dunes, Mojave Desert, California, was intensively studied for three years. A number of parameters - physical, clmatic, behavioral and population - were investigated. Activity cycles are most closely tied to thermal regimes and considerably less so to rainfall and wind. An abundance of small mammal burrows on most of the study area provide thermal refugia on hot days and hibernacula during the winter. Because of the insulating properties of sand and the general lack of frost at Kelso, sidewinder hibernacula are probably scattered over the entire study area and appear to be rather superficial. Mating occurs generally in the spring and the young are born alive in early autumn. Whether the sidewinder reproductive cycle is annual or biennial was not determined. During warm weather sidewinders become active at dusk and may wander over the sand in any direction for over 1200 meters - mostly by sidewinding. The average distance travelled is much shorter, however. This nocturnal wandering probably serves as a dispersal mechanism, since mark and release studies showed no tendency towards homing or territorality. By midnight, however, even the most active sidewinders have formed resting craters and remain coiled therein until sunrise or later. Among rattlesnakes cratering is a feature unique to sidewinders. During the day the crater serves primarily for thermoregulation and less so for concealment, whereas at night this order of importance is reversed. Sidewinders prey upon any small reptile or mammal they can overpower and may actually do a considerable amount of feeding from ambush during the day. After feeding they become sedentary until digestion is largely completed, shifting position only to warm the food bolus during the day. Bio-telemetry studies indicated that the rate of heating or cooling may be more important in thermoregulatory behavior than the simple attainment of absolute thermal thresholds. On cool evenings sidewinders often bask on asphalt roads or railroad rails, using these surfaces as sources of reradiated heat. The sidewinder population is not uniformly distributed on the Kelso study area. More trackways were recorded in dune areas dotted with large clumps of vegetation with stable sand hummocks beneath them. In rockier areas with low vegetation and little sand, sidewinder trackways were few and mostly those of juveniles. This was attributed to inadequate burrows and the general lack of shade in such areas.