PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Diel D.G., Fonseca E.T., Souza S.F., Mazzanti A., Bauermann F., Weiblen R. & Flores E.F. 2005. [Bovine herpesvirus 5 may use the olfactory and trigeminal pathways to invade the central nervous system of rabbits, depending upon the route of inoculation.] O Herpesvírus bovino tipo 5 (BoHV-5) pode utilizar as rotas olfatória ou trigeminal para invadir o sistema nervoso central de coelhos, dependendo da via de inoculação. Pesquisa Veterinária Brasileira 25(3):164-170. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine herpesvirus type 5 (BoHV-5) is a major etiological agent of meningoencephalitis in cattle. Following replication in the nasal mucosa, viral invasion of the brain is thought to occur mainly by the olfactory pathway. To address the role of this pathway in the pathogenesis of neurological infection in a laboratory model, 30 days old rabbits had the main olfactory bulbs (MOBs) surgically removed and were subsequently inoculated intranasally (IN) or conjunctivally (IC) with a highly neurovirulent BoHV-5 strain (SV-507). Following IN inoculation, 10 out of 10 (100 %) control rabbits developed neurological disease. The clinical onset ranged from day 5 to 10 post-inoculation (pi, average 7.5 days); nine being euthanized in extremis and one recovering after a mild clinical course. In contrast, only one rabbit (9.1 %) of the group lacking the MOBs (n=11) developed neurological disease (onset at day 17 pi). Dexamethasone administration to the survivors (n=10) at day 50pi was followed by virus shedding in nasal and/or ocular secretions by 8 animals, demonstrating that the virus was able to reach the trigeminal ganglia (TG) during acute infection. These results demonstrate that the olfactory route provides the main, yet not the sole access to the brain of rabbits following IN inoculation. To address the role of a second pathway, groups of control (n=12) or MOB-lacking rabbits (n=12) were inoculated into the conjunctival sac (IC), following which the virus would be expected to use the ophtalmic branch of the trigeminal nerve to reach the brain. Ten control rabbits (83.3 %) developed neurological disease upon IC inoculation (onset 15.3 days [11 to 20]). Previous ablation of the MOBs did not affect the frequency and course of neurological disease: ten out of 12 rabbits (83.3 %) lacking the MOBs developed neurological disease (onset 9 to 15 dpi, average: 12.7 days) upon IC inoculation. These results demonstrate that both IN and IC routes may operate in the transport of BoHV-5 to the brain of experimentally infected rabbits, depending on the route of inoculation. IN inoculation results in a fast and efficient transport by the olfactory pathway, the trigeminal route providing an alternative, much slower and less efficient transport; IC inoculation results in efficient viral transport by the trigeminal route, yet with a delayed kinetics comparing to the transport provided by the olfactory pathway.

• Bovine herpesvirus type 5 BoHV-5 neurological infection rabbits.

Abstract in Portuguese:

Diel D.G., Fonseca E.T., Souza S.F., Mazzanti A., Bauermann F., Weiblen R. & Flores E.F. 2005. [Bovine herpesvirus 5 may use the olfactory and trigeminal pathways to invade the central nervous system of rabbits, depending upon the route of inoculation.] O Herpesvírus bovino tipo 5 (BoHV-5) pode utilizar as rotas olfatória ou trigeminal para invadir o sistema nervoso central de coelhos, dependendo da via de inoculação. Pesquisa Veterinária Brasileira 25(3):164-170. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine herpesvirus type 5 (BoHV-5) is a major etiological agent of meningoencephalitis in cattle. Following replication in the nasal mucosa, viral invasion of the brain is thought to occur mainly by the olfactory pathway. To address the role of this pathway in the pathogenesis of neurological infection in a laboratory model, 30 days old rabbits had the main olfactory bulbs (MOBs) surgically removed and were subsequently inoculated intranasally (IN) or conjunctivally (IC) with a highly neurovirulent BoHV-5 strain (SV-507). Following IN inoculation, 10 out of 10 (100 %) control rabbits developed neurological disease. The clinical onset ranged from day 5 to 10 post-inoculation (pi, average 7.5 days); nine being euthanized in extremis and one recovering after a mild clinical course. In contrast, only one rabbit (9.1 %) of the group lacking the MOBs (n=11) developed neurological disease (onset at day 17 pi). Dexamethasone administration to the survivors (n=10) at day 50pi was followed by virus shedding in nasal and/or ocular secretions by 8 animals, demonstrating that the virus was able to reach the trigeminal ganglia (TG) during acute infection. These results demonstrate that the olfactory route provides the main, yet not the sole access to the brain of rabbits following IN inoculation. To address the role of a second pathway, groups of control (n=12) or MOB-lacking rabbits (n=12) were inoculated into the conjunctival sac (IC), following which the virus would be expected to use the ophtalmic branch of the trigeminal nerve to reach the brain. Ten control rabbits (83.3 %) developed neurological disease upon IC inoculation (onset 15.3 days [11 to 20]). Previous ablation of the MOBs did not affect the frequency and course of neurological disease: ten out of 12 rabbits (83.3 %) lacking the MOBs developed neurological disease (onset 9 to 15 dpi, average: 12.7 days) upon IC inoculation. These results demonstrate that both IN and IC routes may operate in the transport of BoHV-5 to the brain of experimentally infected rabbits, depending on the route of inoculation. IN inoculation results in a fast and efficient transport by the olfactory pathway, the trigeminal route providing an alternative, much slower and less efficient transport; IC inoculation results in efficient viral transport by the trigeminal route, yet with a delayed kinetics comparing to the transport provided by the olfactory pathway.

Abstract in English:

ABSTRACT.- Spilki F.R., Esteves P.A., Franco A.C., Lima M., Holz C.L., Batista H.B.C.R., Driemeier D., Flores E.F., Weiblen R. & Roehe P.M. 2002. [Neurovirulence and neuroinvasiveness of bovine herpesvirus type 1 and 5 in rabbits.] Neurovirulência e neuroinvasividade de Herpesvírus bovinos tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 22(2):58-63. Centro de Pesquisas Veterinárias Desidério Finamor, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@orion.ufrgs.br In order to determine the capacity of bovine herpesvirus type 1 and 5 (BHV-1 and BHV-5) to invade, multiply and spread along the central nervous system (CNS) (neuroinvasiveness), as well as their potential to induce neurological illness (neurovirulence), 30 to 35 days old rabbits were inoculated with the BHV-5 strain EVI 88 / 95 and Los Angeles and Cooper BHV-1 strains, by the intrathecal (IT) and intranasal (IN) routes. The BHV-5 strain induced severe neurological clinical signs in 100% (12/12) of the rabbits inoculated by both routes. Histopathological examination revealed multifocal non-suppurative meningoencephalitis, characterized by multifocal gliosis and perivascular cuffing. Virus was recovered from many parts of the brain. Both BHV-1 strains, when inoculated via 1T route, were not neurovirulent. The strain Los Angeles, after IN inoculation, induced signs of severe respiratory disease (7/7), as well as signs of neurological impairment, indistinguishable from those induced by BHV-5, in 57% (4/7) of the infected rabbits. However, the rabbits with nervous signs revealed at histopathology vasculitis and thrombosis in lungs and brain, the latter with foci of neuronal necrosis, but no lesions indicative of encephalitis, suggesting that neural damage was probably consequent to tissue anoxia. The BHV-1 strain Cooper, after IN inoculation, induced only mild signs of respiratory disease. These findings indicate that the BHV-5 strain was both neuroinvasive and neurovirulent, since it was capable of invading, spreading and multiplying in the rabbits brains by both routes of inoculation, yet causing neurological disease, apparently consequent to vírus induced neural damage. The BHV-1 Los Angeles strain was not neuroinvasive, whereas its neurovirulence was probably consequent to tissue anoxia, which histologically seemed not to be related to direct viral pathogenic effect. The BHV-1 strain Cooper was neither neurovirulent nor neuroinvasive for rabbits. It is possible that these observations bear relationship with the frequent association of BHV-5 with encephalitis in cattle, as opposed to BHV-1 encephalitis, which is a rare event in nature.

• Infectious bovine rhinotracheitis IBR BHV-1 bovine encephalitis herpesvirus BHV-5 Rinotraqueíte infecciosa bovina herpesvírus da encefalite bovina.

Abstract in Portuguese:

RESUMO.- Spilki F.R., Esteves P.A., Franco A.C., Lima M., Holz C.L., Batista H.B.C.R., Driemeier D., Flores E.F., Weiblen R. & Roehe P.M. 2002. [Neurovirulence and neuroinvasiveness of bovine herpesvirus type 1 and 5 in rabbits.] Neurovirulência e neuroinvasividade de Herpesvírus bovinos tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 22(2):58-63. Centro de Pesquisas Veterinárias Desidério Finamor, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@orion.ufrgs.br Com o objetivo de avaliar a capacidade dos herpesvírus bovinos tipos 1 e 5 (BHV-1 e BHV-5) de invadir e replicar no sistema nervoso central (SNC) (neuroinvasividade), bem como sua capacidade de induzir doença neurológica (neurovirulência), coelhos com 30 a 35 dias de idade foram inoculados com uma amostra do Herpesvírus da Encefalite Bovina (BHV-5; amostra EVI 88/95) ou com amostras de BHV-1 (Los Angeles ou Cooper), pelas vias intratecal (IT) e intranasal (IN). A inoculação da amostra de BHV-5, tanto pela via 1T como IN, induziu sinais clínicos neurológicos em 100% (12/12) dos coelhos inoculados. Os exames histopatológicos revelaram um quadro de meningoencefalite não-purulenta multifocal, caracterizada por gliose multifocal e infiltrados perivasculares. O vírus foi isolado de várias áreas do SNC desses animais. As amostras de BHV-1, quando inoculadas pela via IT, não foram neurovirulentas. A amostra Los Angeles de BHV-1, quando administrada pela via IN, induziu sinais respiratórios severos, além de sinais neurológicos em 57% (4/7) dos animais inoculados. Entretanto, o exame histopatológico destes quatro animais revelou vasculite e trombose no pulmão e cérebro, este último apresentando focos de necrose neuronal, porém sem lesões indicativas de encefalite. Isso sugere que os sinais neurológicos foram, provavelmente, consequentes a prejuízos no fluxo sangüíneo encefálico, e não a danos neuronais provocados pela inoculação desse vírus. A amostra Cooper de BHV-1, quando inoculada pela via IN, induziu apenas sinais leves de infecção respiratória. Estes resultados indicam que apenas a amostra de BHV-5 foi capaz de invadir e replicar no encéfalo dos coelhos quando inoculada tanto por via IN como IT, apresentando neuroinvasividade e neurovirulência. É possível que estas observações tenham relação com o fato de amostras de BHV-5 freqüentemente causarem encefalites, em contraposição a infecções pelo BHV-1, onde encefalites são raramente observadas.

Abstract in English:

ABSTRACT.- Beltrão, N., Flores E.F., Weiblen R., Silva A.M., Roehe, P.M. & lrigoyen L.F. 2000. [Acute infection and neurological disease by bovine herpesvirus type-5 (BHV-5): Rabbits as an experimental model.] Infecção aguda e enfermidade neurológica pelo herpesvírus bovino tipo 5 (BHV-5): coelhos como modelo experimental. Pesquisa Veterinária Brasileira 20(4):144-150. Depto Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. Rabbits are susceptible to bovine herpesvirus type 5 (BHV-5) infection and often develop an acute and fatal neurological disease upon intranasal inoculation. The kinetics of viral infection of the central nervous system (CNS) was investigated by testing serial brain sections for infectivity at intervals after virus inoculation. The virus was first detected in the main olfactory bulb at 48h, followed by the olfactory cortex at 48/72h. At 72/96h infectivity was also detected in the trigeminal ganglia, pons and cerebral cortex. Two experiments were conducted to investigate the role of the olfactory system in the invasion of the rabbits’ CNS by BHV-5. In the first experiment, rabbits were inoculated with two BHV-5 isolates in the conjunctival sac. Rabbits inoculated by this route developed the neurological disease, yet with a reduced frequency and delayed clinical course. In a second experiment, twelve rabbits were submitted to surgical removal of the olfactory bulb and subsequently inoculated intranasally with BHV-5. Eleven out of 12 (91.6%) of the control rabbits developed the disease, against four out of 12 (33.3%) of the animals lacking the olfactory bulb. These results suggest that the olfactory system is the main pathway utilized by BHV-5 to reach the CNS of rabbits after intranasal inoculation. Nevertheless, the development of neurological infection in rabbits inoculated in the conjunctival sac and in rabbits lacking the olfactory bulb indicate that BHV- 5 may utilize an alternative route to invade the CNS, probably the sensory and autonomic fibers of the trigeminal nerve. The effects of immunization with homologous (BHV-5) and heterologous (BHV-1) strains in prevention of neurological disease by BHV-5 were investigated. Five out of 10 rabbits (50%) immunized with BHV-5 showed mild and transient neurological signs and one died upon challenge. Interestingly, the degree of protection against BHV-5 challenge was higher in rabbits immunized with BHV-1: only two rabbits showed transiente neurological signs and subsequently recovered. Thus, prevention of neurological disease by BHV-5 in rabbits may be achieved by immunization with either BHV-5 or BHV-1, likely reflecting the extensive serological cross-reactivity between these viruses. Further studies in rabbits may help in understanding the pathogenesis and immune response to BHV-5 infection.

• Bovine herpesvirus type 5 (BHV-5) meningo-encephalitis rabbits experimental model Herpesvírus Bovino tipo 5 meningoencefalite coelhos modelo experimental.

Abstract in Portuguese:

RESUMO.- Beltrão, N., Flores E.F., Weiblen R., Silva A.M., Roehe, P.M. & lrigoyen L.F. 2000. [Acute infection and neurological disease by bovine herpesvirus type-5 (BHV-5): Rabbits as an experimental model.] Infecção aguda e enfermidade neurológica pelo herpesvírus bovino tipo 5 (BHV-5): coelhos como modelo experimental. Pesquisa Veterinária Brasileira 20(4):144-150. Depto Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. Coelhos são susceptíveis à infecção pelo herpesvírus bovino tipo 5 (BHV-5) e freqüentemente desenvolvem enfermidade neurológica aguda fatal após inoculação intranasal. A cinética da invasão do sistema nervoso central (SNC) de coelhos pelo BHV-5 foi estudada através de pesquisa de vírus em secções do SNC a diferentes intervalos pósinoculação. Após inoculação intranasal, o vírus foi inicialmente detectado no bulbo olfatório às 48h, seguido do córtex olfatório às 48/72h. Às 72/96h o vírus foi detectado também no gânglio trigêmeo, ponte e córtex cerebral. Dois experimentos foram realizados para avaliar a importância do sistema olfatório na invasão do SNC de coelhos pelo BHV-5. No primeiro experimento, coelhos foram inoculados com duas amostras do BHV-5 no saco conjuntival. Coelhos inoculados por essa via também desenvolveram a enfermidade neurológica, porém com menor freqüência com curso clínico tardio. No segundo experimento, doze coelhos foram submetidos à ablação cirúrgica do bulbo olfatório e posteriormente inoculados com o BHV-5 pela via intranasal. Onze de 12 coelhos controle (91,6%), não submetidos à cirurgia, desenvolveram a doença neurológica, contra quatro de 12 (33,3%) dos animais submetidos à remoção cirúrgica do bulbo olfatório. Esses resultados demonstram que o sistema olfatório constitui-se na principal via de acesso do BHV-5 ao encéfalo de coelhos após inoculação intranasal. No entanto, o desenvolvimento de infecção neurológica em coelhos inoculados pela via conjuntival e em coelhos sem o bulbo olfatório indica que o BHV-5 pode utilizar outras vias para invadir o SNC, provavelmente as. fibras sensoriais e autonômicas que compõe o nervo trigêmeo. Os efeitos da imunização com vírus homólogo (BHV-5) e heterólogo (BHV-1) na proteção à infecção neurológica foram investigados. Cinco entre 10 coelhos (50%) imunizados com o BHV-5 apresentaram sinais neurológicos discretos e transitórios e um morreu após o desafio com o BHV-5. Curiosamente, o grau de proteção foi superior nos coelhos imunizados com o BHV-1: apenas dois animais apresentaram sinais clínicos passageiros e recuperaram-se. Portanto, proteção da enfermidade neurológica pelo BHV-5 em coelhos pode ser obtida por imunização com o BHV-5 ou BHV-1, provavelmente devido à extensa reatividade sorológica cruzada entre esses vírus. Estudos adicionais em coelhos podem auxiliar no esclarecimento da patogênese e resposta imunológica a infecção pelo BHV-5.

Abstract in English:

ABSTRACT.- Brito M.F., França T.N., Oliveira K.D. & Cerqueira V.D. 2000. [Experiments in rabbits with cyanogenic plants.] Estudos experimentais em coelhos com plantas cianogênicas. Pesquisa Veterinária Brasileira 20(2):65-70. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. The dried leaves of Piptadenia macrocarpa Benth. 1 =Anadenanthera macrocarpa (Benth.) Brenan], Piptadenia viridiflora (Kunth.) Benth. and Holocalyx glaziovii Taub. [=Holocalyx balansae Micheli], all trees of the Leguminosae Mimosoideae family, were given orally to rabbits in single doses. In the case of H. glaziovii, leaves were fed after being stored in two diferente ways. In the first series of experiments, Piptadenia macrocarpa failed to poison rabbits although the leaves were collected when sprouting, the most toxic stage forcattle. The experiments were performed 4 to 6 months after the leaves had been collected and dried. In a second series of experiments, similar leaves were fed at monthly intervals after harvest. They were toxic for the first 5 months, but were innocuous after 6 months storage. In both series of experiments the leaves were dried in the shade and then kept in cotton sacks at room temperature. They always were milled at the occasion of the experiments. These experiments with rabbits confirm the results with cattle, in which severe poisoning was caused by leaves stored for 3 months but caused no ili effect after 4 months, even when fed in large amounts. Young leaves of P. viridiflora were lethal at 12 g/kg, 12 months after collection and drying. In a second experiment the lethal dose was only 6 g/kg with leaves stored for only 2 months. These results show that the dried leaves of these species lose toxicity with time. Holocalyx glaziovii leaves were milled 6 weeks after collecting and dried and stored in sealed containers. They were fed in. single doses to different rabbits at intervals during a whole year. Lethal doses were initially 0.75 g/kg to 1.5 g/kg but rose to 1.5 g/kg to 3 g/kg by the end of the year. In a second experiment, leaves stored in cotton sacks and milled just before feeding were compared with milled leaves stored in sealed glass containers. The plant material kept in cotton sacks had halfthe toxicity of the leaves stored.for 2 months in sealed containers. After 10 to 12 months it was only a little less toxic than that stored in the sealed containers but there were no differences after 14 months. The symptoms observed in the rabbits that were poisoned by the dried leaves of P. macrocarpa, P. viridiflora and H. glaziovii were neuromuscular. Post-mortem findings and histopathological findings were almost absent. On opening the stomach, a strong smell of bitter almonds was sometimes noticed. The degree of toxicity during the storage of the dried leaves of he three tested plants was generallywell correlated with the picrate testfor cyanide.

• Poisonous plants experimental poisoning hydrocyanic poisoning Piptadenia macrocarpa Piptadenia anadenanthera Piptadenia viridiflora Holocalyx glaziovii Holocalyx balansae rabbits Plantas tóxicas intoxicação experimental intoxicação cianídrica coelhos.

Abstract in Portuguese:

RESUMO.- Brito M.F., França T.N., Oliveira K.D. & Cerqueira V.D. 2000. [Experiments in rabbits with cyanogenic plants.] Estudos experimentais em coelhos com plantas cianogênicas. Pesquisa Veterinária Brasileira 20(2):65-70. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. A administração por via oral das folhas dessecadas de Piptadenia macrocarpa (Benth. [ =Anadenanthera macrocarpa (Benth.) Brenan], Piptadenia viridiflora (Kunth.) Benth. e Holocalyx glaziovii Taub. [ =Holocalyx balansae Micheli], plantas cianogênicas da família Leguminosae Mimosoideae, revelou a sensibilidade do coelho à elas, caracterizando-se a intoxicação por sintomatologia de natureza neuromuscular. A dose letal de P. macrocarpa foi de 6 g/kg para a brotação dessecada, até 5 meses após sua coleta; 6 meses depois da coleta a planta havia perdido a toxidez. A dose letal de P. viridiflora foi também de 6 g/kg para a brotação dessecada, coletada dois meses antes dos experimentos; 10 meses após a coleta a planta havia perdido metade da toxidez. Com H. glaziovii foram realizadas duas séries experimentais; estabeleceu-se a dose letal entre 0,75 e 1,5 g/kg com a planta coletada 2 meses antes, também com perda aproximada de metade da toxidez no período de 12 meses. O experimentos indicam, que H. glaziovii, moída logo após a coleta e armazenada em vidros fechados com tampa plástica, conserva melhor a toxidez nos primeiros meses do que a planta guardada em sacos de algodão, porém, ao final de um ano, essa diferença deixa de existir. A toxidez das folhas dessecadas foi proporcional à intensidade das reações das mesmas ao teste do papel picro-sódico, com raras exceções.

Abstract in English:

ABSTRACT.- Tokarnia C.H., GavaA., Brito M.F., Bezerra P.S. & Oliveira K.D. 1998. [Experimental poisoning in rabbits by Mascagnia sp (Malpighiaceae) collected in the State of Santa Catarina, southern Brazil.] Intoxicação experimental em coelhos por Mascagnia sp (Malpighiaceae) procedente do Estado de Santa Catarina. Pesquisa Veterinária Brasileira 18(2):61-64. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. Freshly dried and ground young leaves or sprouts and mature leaves of Mascagnia sp, a creeping shrub of the Malpighiaceae family from Santa Catarina, known to be toxic to cattle, were suspended in water and given by gastric tube to adult rabbits. The rabbits showed first symptoms of poisoning between 3 hours and 24h49min after the beginning of feeding. The course of poisoning varied from 1 to 4 minutes. Symptoms consisted of generally violent incoordinated movements, followed by animals falling on their side, with dyspnea, slowing respiratory movements, a few final shrieks and death. The post-mortem findings were only hepatic congestion and splenomegaly. The lobulation of the liver was distinct; sometimes the centres of the lo bules were lighter in collor. Histopathology revealed regressive and circulatory alterations in the liver, kidneys and spleen. The lethal dose of the plant was very variable. The experiments did not allow to conclude if origin, growth stage or time of harvest influence its toxicity. The ground plant, kept in well closed recipients at room temperature for a year, was shown to have lost variable amounts of toxicity.

• Poisonous plants experimental poisoning Mascagnia sp Malpighiaceae rabbit Plantas tóxicas intoxicação experimental coelho.

Abstract in Portuguese:

RESUMO.- Tokarnia C.H., GavaA., Brito M.F., Bezerra P.S. & Oliveira K.D. 1998. [Experimental poisoning in rabbits by Mascagnia sp (Malpighiaceae) collected in the State of Santa Catarina, southern Brazil.] Intoxicação experimental em coelhos por Mascagnia sp (Malpighiaceae) procedente do Estado de Santa Catarina. Pesquisa Veterinária Brasileira 18(2):61-64. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. As folhas novas ou a brotação e as folhas maduras de Mascagnia sp, arbusto escandente da família Malpighiaceae, procedente de Santa Catarina, planta comprovadamente tóxica a bovinos, foram administradas sob forma de pó suspenso em água por sonda gástrica, até poucas semanas após a sua colheita, a 45 coelhos adultos. A planta colhida em três municípios do Estado de Santa Catarina, dessecada na sombra a temperatura ambiente, demonstrou possuir toxidez também para essa espécie animal. Porém a sua toxidez para coelhos foi muito variável. Os experimentos realizados não permitem concluir que a procedência da planta, o seu estado de evolução ou a época do ano da colheita, sejam fatores que influenciam a sua toxidez. Já em relação ao quadro clínico, os achados de necropsia e histopatológicos, a planta teve um comportamento muito constante. Os coelhos mostraram os primeiros sintomas de intoxicação entre 3 horas e 24h49min após o começo da administração da planta. A evolução do quadro clínico foi de 1 a 4 minutos. Os sintomas consistiram sempre em que o animal subitamente começava a fazer movimentos desordenados, geralmente violentos; finalmente ficava caído, tinha respiração dispnéica com movimentos respiratórios cada vez mais espaçados, dava alguns gritos e logo morria. Os achados de necropsia se resumiram em congestão hepática e esplenomegalia; o fígado ao corte tinha a lobulação nítida, às vezes com o centro dos lóbulos mais claro. Os exames histopatológicos revelaram alterações regressivas e circulatórias no fígado, rim e baço. A planta moída guardada em vidros hermeticamente fechados com tampa plástica e à temperatura ambiente, submetida a experimentos em outros 22 coelhos 1 ano ou mais após sua colheita, demonstrou ter perdido variavelmente em toxidez.

Abstract in English:

ABSTRACT.- Brito M.F. & Tokamia C.H. 1997. [Experimental poisoning by the ground seeds of Ricinus communis (Euphorbiaceae) in the rabbit.] Intoxicação experimental pelas sementes trituradas de Ricinus communis (Euphorbiaceae) em coelhos. Pesquisa Veterinária Brasileira 17(1):1-7. Projeto Saúde Animal Embrapa/UFRRJ, Km 47, Seropédica, Rio de Janeiro 23851- 970, Brazil. The ground seeds of Ricinus communis L., given by stomach tube in single doses to rabbits, caused severe symptoms of poisoning, lethal in three rabbits which received the dose of 2 g/ kg and in one of four rabbits which received 1 g/kg; the other three rabbits which received the lower dose, showed slight to moderate symptoms and recovered. Three other rabbits, which received 0.5 g/kg, showed only slight symptoms. The period between administration of the seeds and death or recovery, varied from 12h47min to 68h08min, and from 3 to 6 days, respectively. First clinical symptoms after the administration of the seeds were observed about 8 hours in the lethal cases and in those where the animals showed more than slight symptoms, and about 24 hours in the cases with only slight symptoms. The course of the poisoning varied from 4 to 56 hours in the lethal cases and froin 2 to 5 and half days in the cases with recovery. The clinical signs consisted mainly in digestive distress; the animals showed inappetence or anorexia. Faeces were generally scarce, with bolus altered in form and size, dark, sometimes soft, with mucus. There were manifestations of colic. The most evident post-mortem findings were in the small intestine and cecum, which had liquid contents; its wall was congested and edematous, and fibrine covered the mucosa as pseudomembranes or was found in the lumen as flakes and or filaments. The most important histological changes were seen also in the small intestine and cecum. In the former there was coagulative necrosis associated with congestion/ hemorrhages of the mucosa and submucosa which also showed edema. Similar lesions were seen in the cecum, but thése were less marked, with exception of the edema of the submucosa. In colon and rectum the changes were slight or absent. Necrosis with marked caryorhexis of the macrophages, which migrated to the upper mucosal layer, was seen in the lymphoid follicles of the appendix vermiformis and in one case also of the rudimentary cecum.

• Poisonous plants experimental plant poisoning Ricinus communis Euphorbiaceae pathology Rabbit Plantas tóxicas intoxicação experimental por plantas patologia coelhos.

Abstract in Portuguese:

SINOPSE.- Brito M.F. & Tokamia C.H. 1997. [Experimental poisoning by the ground seeds of Ricinus communis (Euphorbiaceae) in the rabbit.] Intoxicação experimental pelas sementes trituradas de Ricinus communis (Euphorbiaceae) em coelhos. Pesquisa Veterinária Brasileira 17(1):1-7. Projeto Saúde Animal Embrapa/UFRRJ, Km 47, Seropédica, Rio de Janeiro 23851- 970, Brazil. As sementes trituradas de Ricinus communis L., administradas em doses únicas por sonda intragástrica a coelhos, causaram graves sintomas de intoxicação com êxito letal nos três coelhos que receberam a dose de 2 g/kg e em um dos quatro que receberam 1 g/kg. Os outros três coelhos que receberam 1g/kg desenvolveram sintomas discretos a moderados e se recuperaram, e os três que receberam 0,5g/kg só mostraram sintomas discretos. O período entre a administração das sementes e a morte ou recuperação variou de 12h47min a 68h08min, e de 3 a 6 dias, respectivamente. Os primeiros sintomas após a administração das sementes, foram observados dentro de cerca 8 horas nos casos letais e nos animais que adoeceram moderadamente, e dentro de cerca 24 horas nos casos com sintomatogia discreta. A evolução da intoxicação variou de 4 a 56 horas nos casos letais e de 2 a 5 meio dias nos casos de recuperação. A sintomatologia consistiu principalmente de perturbações digestivas. Os animais apresentaram inapetência até anorexia. As fezes geralmente eram escassas, com forma e tamanho das síbalas alteradas, eram escuras, às vezes pastosas, com muco. Havia nítidas manifestações de cólica. Os achados de necropsia mais evidentes foram constatados no intestino delgado e ceco. O conteúdo destes segmentos era líquido. A parede apresentou congestão e edema e havia fibrina recobrindo a mucosa sob forma de pseudomembranas, ou na luz sob forma de flocos e/ou filamentos. As alterações histológicas mais importantes foram verificadas no intestino delgado e ceco. No intestino delgado observou-se necrose de coagulação associada a congestão/hemorragias na mucosa. Havia ainda congestão/hemorragias e edema na submucosa. Lesões semelhantes foram vistas no ceco onde porém, com exceção do edema da submucosa, eram menos acentuadas. No cólon e reto as lesões eram leves ou ausentes. Foi verificado no apêndice vermiforme e em um caso também no ceco rudimentar, necrose com acentuada cariorrexia de macrófagos que migraram dos folículos linfóides para a parte superior da mucosa.

Abstract in English:

The ground or whole seeds of Abrus precatoríus L., given by stomach tube in single doses to rabbits, caused a clinic-pathological picture of enteritis. The ground seeds caused death of all rabbits which received 0.03125 g/kg or more; doses of 0.015625 g/kg, 0.007812 g/kg and 0.003906 g/kg caused death of always one of three rabbits which received one of the doses. The dose of 0.001953 g/kg caused only slight symptoms in one of three rabbits tested; doses of 0.0009765 g/kg and 0.00048825 g/kg, each given to two rabbits, did not cause any symptoms. The whole seeds caused death of two rabbits which received the doses of 0.75 g/kg and 0.375 g/kg; doses of 0.25 g/kg and 0.125 g/kg, each one given to three rabbits, caused death of two from each group. The dose of 0.625 g/kg given to six rabbits, caused death only of one. The dose of 0.03125 g/kg did not cause any symptoms of poisoning in six rabbits. The period between the administration of the seeds and death varied from 13h35min to 7 days in the experiments with the ground seeds, and from 29hl 4min to 59h40min in the experiments with the whole seeds. The period between the administration of the seeds and recovery varied from 3 and a half days to 17 days in the experiments with the ground seeds and from 2 to 16 days in the experiments with the whole seeds. All 44 rabbits used in these experiments received the seeds only once. The clinic-pathological picture of the poisoning, which was the sarne in the experiments with the ground and the whole seeds of A.precatorius, consisted in inappetence/ anorexia, few faeces with bolus altered in form and size, sometimes dark coloured, soft or liquid, of foetid odor, with mucus and seldom with fibrina. There were manifestations of colic. The most important post-mortem changes were found in the small intestine and cecum. The former was distended by large amounts of liquid and mucous contents. Its wall was congested throughout its length and sometimes edematous, and fibrine covered the mucosa. The cecum was distended by soft to liquid contents and its wall showed congestion/hemorrhages and edema. The wall of the proximal colon was hemorrhagic and mucus was sometimes found in the lumen. In the rabbits which received the whole seeds, some of them were found in the stomach or rectum. In most rabbits slight to moderate splenomegaly was observed. The most important histological changes were seen in the digestive tract, mainly in the small intestine and less pronounced in the cecum. Few or no changes were observed in stomach and colon. The changes found in the different parts of the intestine were similar and consisted in coagulative necrosis of the mucosa with presence of nuclear fragments, congestion/hemorrhages of the mucosa, submucosa, muscularis and serosa, as well as edema of the submucosa. Additionally in the small intestine large amounts of nuclear fragments were seen in the upper portion of the lymphoid follicles and in smaller amounts in its center. In the appendix vermiformis, and in many cases also in the rudimentar cecum, variable amounts of nuclear fragments were seen in the stroma of the mucosa which resulted from necrosis by caryorhexis of macrophages of the lymphoid follicles, which migrated towards the intestinal lumen. In most rabbits thers was congestion of the spleen and mesenteric lymphnodes.

• Poisonous plants experimental plant poisoning Abrus precatorius Leguminosae Papilionoideae pathology rabbit

Abstract in Portuguese:

A administração por sonda intragástrica das sementes trituradas ou inteiras de Abrus precatorius L., em doses únicas, provocou em coelhos um quadro clínicopatológico grave de enterite. As sementes moídas causaram a morte de todos os coelhos a partir da dose de 0,03125 g/kg; as de 0,015625 g/kg, 0,0078125 g/kg e 0,003906 g/ kg causaram a morte, para cada uma dessas dosagens, de um de três coelhos. A dose de 0,001953 g/kg causou só sintomas leves em um de três coelhos e as de 0,0009765 g/kg e 0,00048825 g/kg não causaram sintomas nos dois coelhos para cada dosagem. As sementes inteiras causaram morte dos dois coelhos que receberam as doses de 0,75 g/kg e 0,375 g/kg; as de 0,25 e 0,125 g/kg causaram a morte, para cada uma dessas dosagens, de dois de três coelhos. A dose de 0,0625 g/kg causou a morte de um de seis coelhos. A dose de 0,03125 g/kg não causou sintomas de intoxicação em seis coelhos. O período entre a administração das sementes e a morte variou, nos experimentos com as sementes moídas, de 13h35min a 7 dias e nos experimentos com sementes inteiras, de 29h14min a 59h40min. O período entre a administração das sementes e a recuperação, variou, nos experimentos com as sementes moídas, de 3 e meio dias a 17 dias e nos experimentos com as sementes inteiras, de 2 a 16 dias. Todos os 44 coelhos usados nesses experimentos receberam as sementes de A. precatorius somente uma vez. O quadro clínico-patológico da intoxicação era o mesmo para a intoxicação pelas sementes moídas ou inteiras de A. precatorius. Os sintomas de intoxicação consistiram em inapetência/anorexia, fezes escassas e com forma e tamanho das síbalas alteradas, às vezes escuras, pastosas, líquidas, fétidas, com muco e raramente com fibrina. Havia sinais de cólica bem manifestos. Os achados de necropsia mais importantes ocorreram no intestino delgado e ceco. O intestino delgado estava muito dilatado com abundante conteúdo líquido-mucoso. Havia congestão da parede em toda extensão; às vezes edema. Fibrina revestia a mucosa. O ceco estava dilatado com conteúdo pastoso-líquido, a parede apresentava congestão/hemorragias e edema. No colon proximal às vezes havia muco na luz e homorragias na parede. Nos coelhos que receberam as sementes inteiras, algumas delas eram encontradas no estômago ou no rato. Na maioria dos coelhos havia ainda discreta a moderada esplenomegalia. As alterações histológicas mais importantes foram verificadas no tubo digestivo. Os segmentos mais afetados foram o intestino delgado e, com menor intensidade, o ceco. No estômago e colon as alterações foram poucas ou ausentes. As lesões nas diversas partes do intestino foram muito semelhantes e consistiram em necrose de coagulação da mucosa com presença de fragmentos nucleares, congestão/ hemorragias na mucosa, submucosa, muscular e serosa, e edema da submucosa. Na superfície dos folículos linfoides do intestino delgado observou-se grande quantidade de fragmentas nucleares; no interior desses folículos o grau de fragmentação era menor. No apêndice vermiforme e com menor frequência no ceco rudimentar, observou-se quantidade variável de fragmentos nucleares no estroma da mucosa, resultante da necrose por cariorrexia de macrófagos dos folículos linfóides que após ativação migraram em direção a luz intestinal. Na maioria dos coelhos havia ainda congestão do baço e dos linfonodos mesentéricos.

• Plantas tóxicas intoxicação experimental por plantas Abrus precatorius Leguminosae Papilionoideae patologia coelhos

Abstract in English:

The ultrastructure of bone cells of mid-diaphysis of the humerus of young rabbits that received by gastric tube a water estract of Solanum malacoxylon corresponding to 100 mg/kg of body weight is described. Atrophic, degenerated and necrotic osteocytes anel mineralization of perilacunar osteoiel were the main lesions. Osteoblasts were atrophic with diminution of synthetic organels. Osteoclasts exhibited a ruffle border in dose contact with the non eroded mineralized matrix, poorly developecl vesicular region and absent clear zone. Macrophages in fusion forming multinucleated giant cells wcre seen in some resorption cavities. It is suggested that the 1,25(OH)2D3 present in the plant is responsible for the cell changes, inhibition of osteoclastic and osteocytic resorption anel osteopetrosis.

• Bane pathology osteocyte osteoblast osteoclast ultrastructure Solanum malacoxylon calcitriol rabbit.

Abstract in Portuguese:

É descrita a ultra-estrutura das células ósseas da cortical da diáfise do úmero de coelhos jovens que receberam, diariamente, via sonda gástrica, um extrato aquoso de Solanum malacoxyloncorrespondente a 100mg da planta seca por quilograma de peso corporal e foram sacrificados 96 horas após o início do experimento. Osteócitos mostravam diversos graus de atrofia e necrose. Lacunas osteocíticas com restos celulares ou vazias foram vistas com frequência. Mineralização do tecido osteóide perilacunar foi constantemente observada. Os osteoblastos mostravam atrofia, diminuição das organelas de síntese e, em algumas oportunidades, exibiam núcleos picnóticos e estavam livres nos canais de Havers. Os osteoclastos mostravam borda pregueada em íntimo contato com a matriz mineralizada não erodida, região vesicular pouco desenvolvida e ausência da zona clara na periferia da borda pregueada. Em alguns canais de Havers, foram identificados macrófagos em processo de fusão para formarem células gigantes. Sugere-se que a osteopetrose descrita na intoxicação por S. malacoxylon seja decorrente de inibição das atividades de reabsorção osteocítica e osteoblástica, por efeito direto da ação de 1,25(OH)2D3.

• Patologia óssea osteócito osteoblasto osteoclasto ultra-estrutura Solanum malacoxylon calcitriol coelho

Abstract in English:

Experimental studies were performed on Baccharis coridifolia D.C. (Compositae), a small shrub with the popular name "mio-mio", one of the more important poisonous plants of southern Brazil, Uruguay, Argentina and Paraguay, in arder to find out possible variations in toxicity due to its origin, sex, plant parts and annual variability. Doses which varied from 0.085 to 5.44 g/kg of the dried powdered aerial parts of B. coridifolia were administered in aqueous suspension by stomach tube to 49 adult rabbits. The plant material was collected in five different localities, from four sites in Brazil and one in Uruguay, in the flowering/seeding stage and separated by sex; in some regions collections were made in two successive years. From three of the sites additionally only the leaves of female plants were used for the experiments. Sixteen animals died and one that showed severe symptoms was euthanized together with the contral animal. Nineteen animals that showed slight to severe symptoms, recovered. First symptoms after the administration of the plant were seen, in the fatal cases from 6h32min to 1 day 6h15min, and in the non-fatal cases from 4h03min to 24h00min, after ingestion. The clinical course, in the fatal cases, varied from approximately 6h00min to 4 days 20h23min and, in the non-fatal cases, from 9h25min to 11 days 3h45min. The length of time from first administration of the plant till death varied from 14h20min to 5 clays 2h55min. The lethal dose varied from 0.17 to 5.44 g/kg. The main symptoms were anorexia, modifications in the form, size and consistency of the faeces and hair loss. The main post-mortem alterations were found in the stomach, caecum and liver. There was red colouration of the stomach mucosa. ln the caecum the surface of the mucosa was rough and red and the wall was oedematous. The liver was clearer than normal with perceptible lobulation. Histopathologically these lesions correspond to 1) coagulative necrosis associated with haemorrhages and oedema of the stomach mucosa, 2) haemorrhagic necrosis of the mucosa and oedema and/or haemorrhages of the submucosa of the caecum and 3) cloudy swelling and/or vacuolization of the liver. Greater toxicity of B. coridifolia was associated with more southerly sites of collection in Brazil. The female plant was up to 32 times more poisonous than the male plant; the whole aerial pa1ts of the plant were up to 16 times more poisonous when compared with only the leaves. There was up to a fourfold variation in toxicity from year to year. These differences can be explained by variations in the type and the amount of macrocyclic trichothecenes accumulated in the different parts of the plant, which are believed to be absorbed from the soil fungus Myrothecium verrucaria which produces them. B. coridifolia was compared with B. megapotamica var. weirii, which does not show these variations.

• Poisonous plants experimental plant poisoning Baccharis coridifolia Compositae "mio-mio" pathology rabbit trichothecenes

Abstract in Portuguese:

Foram realizados estudos experimentais com Baccharis coridifolia D.C. (Compositae), subarbusto, vulgarmente conhecido como "mio-mio", uma das plantas tóxicas mais importantes no sul do Brasil, Uruguai, Argentina e Paraguai, com a finalidade de verificar possíveis variações na sua toxidez de acordo com sua procedência, sexo, as diversas partes da planta e de um ano para outro. Foram administradas, a 49 coelhos adultos, em suspensão aquosa, via intragástrica, doses variando de 0,085 a 5,44 g/kg, das partes aéreas dessecadas e pulverizadas de B. coridifolia coletada em quatro procedências do sul do Brasil e uma do Uruguai, em floração/frutificação, separada por sexo e, de parte das regiões, em dois anos consecutivos; com a planta do sexo feminino de três destas procedências, realizaram-se, ainda, experimentos em que se administraram somente as folhas. Dezesseis animais morreram, um adoeceu acentuadamente sendo sacrificado junto com o controle e 19 adoeceram discreta a acentuadamente, recuperando-se. O prazo entre a administração da planta e o início dos sintomas, nos casos fatais, variou de 6h32min a 1 dia 6h15min e para os animais que sobreviveram, de 4h03min a 24h00min. A evolução clínica, nos casos fatais, variou de aproximadamente 6h00min. A 4 dias 20h23min e a recuperação, dos que sobreviveram, de 9h25min a 11 dias 3h45min. O prazo entre a administração da planta e a morte dos animais variou de aproximadamente 14h20min a 5 dias 2h55min. A dose letal variou de 0,17 a 5,44 g/kg. Os principais sintomas consistiram em anorexia, alteração na forma, tamanho e consistência das fezes e perda de pêlos. Os principais achados de necropsia ocorreram no estômago, ceco e fígado, consistindo em avermelhamento da mucosa estomacal, mucosa com superfície rugosa e de cor vermelha e edema da parede do ceco e fígado mais claro e com lobulação perceptível. Estas lesões corresponderam histopatologicamente à necrose de coagulação associada a hemorragias e edema da mucosa estomacal, à necrose hemorrágica da mucosa e edema e/ou hemorragia da submucosa do ceco e à tumefação e/ou vacuolização hepáticas. B. coridifolia mostrou-se mais tóxica quanto mais para o sul do Brasil; a planta feminina foi até 32 vezes mais tóxica do que a masculina; as partes aéreas da planta, folhas, flores e caule finos juntos, foram até 16 vezes mais tóxicas, quando comparadas com somente as folhas; mostrou-se com maior ou menor toxidez de um ano para outro, com diferença na dose letal de até quatro vezes. Tais variações podem ser explicadas por diferenças no tipo e quantidade de tricotecenos macrocíclicos acumulados nas suas diversas partes, que parecem ser absorvidos do fungo do solo Myrothecium verrucaria, que os produz. B. coridifolia foi comparada com B. megapotamica var. weirii, que não apresenta tais variações.

• Plantas tóxicas intoxicação experimental por plantas Baccharis coridifolia Compositae "mio-mio" patologia coelhos tricotecenos.

Abstract in English:

The sprouting and flowering parsley, Carun petroselinum Benth. et Hook. ( = Petroselínum crispum (Mill) Nym. ex A. W. Hill), of the Umbelliferae family, was given ad libitum to 5 rabbits. The animals consumed between 92.6 g/kg (in 3 days) and 433.4 g/kg (in 4 days) and did not show any symptoms of poisoning. Initially they ate the plant well, but during the following days the appetite for the plant diminished, and between the 4th and 6th day the rabbits stopped to eat it.

• Carun petroselinum Petroselinum crispum parsley Umbelliferae plant poisoning rabbits

Abstract in Portuguese:

A administração de Carun petroselinum Benth. et Hook. ( = Petroselinum crispum (Mill) Nym. ex A. W. Hill), a "salsinha", da família Umbelliferae, administrada ad libitum a 5 coelhos em doses que variaram entre 92,6 g/kg (em 3 dias) e 433,4 g/kg (em 4 dias) da planta fresca, em brotação ou em floração, não provocou sintomas de intoxicação. Observou-se que inicialmente os coelhos comiam avidamente a planta, porém, nos dias seguintes o apetite pela planta diminuiu, até sua completa recusa a partir do 4º ao 6º dia.

• Carun petroselinum Petroselinum crispum Umbelliferae "salsinha" intoxicação por planta coelhos