PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Silva S.C., Brum M.C.S., Oliveira S.A.M., Weiblen R. & Flores E.F. 2011. A thymidine kinase-negative bovine herpesvirus 5 is highly attenuated for rabbits, but is neuroinvasive and establishes latent infection. Pesquisa Veterinária Brasileira 31(5):389-397. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com Mutant viral strains deleted in non-essential genes represent useful tools to study the function of specific gene products in the biology of the virus. We herein describe an investigation on the phenotype of a bovine herpesvirus 5 (BoHV-5) recombinant deleted in the gene encoding the enzyme thymidine kinase (TK) in rabbits, with special emphasis to neuroinvasiveness and the ability to establish and reactivate latent infection. Rabbits inoculated with the parental virus (SV-507/99) (n=18) at a low titer (105.5TCID50) shed virus in nasal secretions in titers up to 104.5TCID50 for up to 12 days (average: 9.8 days [5-12]) and 5/16 developed neurological disease and were euthanized in extremis. Rabbits inoculated with the recombinant BoHV-5TKD at a high dose (107.1TCID50) also shed virus in nasal secretions, yet to lower titers (maximum: 102.3TCID50) and for a shorter period (average: 6.6 days [2-11]) and remained healthy. PCR examination of brain sections of inoculated rabbits at day 6 post-infection (pi) revealed a widespread distribution of the parental virus, whereas DNA of the recombinant BoHV-5TKD-was detected only in the trigeminal ganglia [TG] and olfactory bulbs [OB]. Nevertheless, during latent infection (52pi), DNA of the recombinant virus was detected in the TGs, OBs and also in other areas of the brain, demonstrating the ability of the virus to invade the brain. Dexamethasone (Dx) administration at day 65 pi was followed by virus reactivation and shedding by 5/8 rabbits inoculated with the parental strain (mean duration of 4.2 days [1 – 9]) and by none of seven rabbits inoculated with the recombinant virus. Again, PCR examination at day 30 post-Dx treatment revealed the presence of latent DNA in the TGs, OBs and in other areas of the brain of both groups. Taken together, these results confirm that the recombinant BoHV-5TKD is highly attenuated for rabbits. It shows a reduced ability to replicate in the nose but retains the ability to invade the brain and to establish latent infection. Additional studies are underway to determine the biological and molecular mechanisms underlying the inability of BoHV-5TKD to reactivate from latency.

• BoHV-5 neuroinvasiveness thymidine kinase-bovine herpesvirus 5 neuroinvasividade herpesvírus bovino tipo 5 timidina quinase

Abstract in Portuguese:

RESUMO.- Silva S.C., Brum M.C.S., Oliveira S.A.M., Weiblen R. & Flores E.F. 2011. A thymidine kinase-negative bovine herpesvirus 5 is highly attenuated for rabbits, but is neuroinvasive and establishes latent infection. [Cepa do herpesvírus bovino tipo 5 defectiva na timidina quinase é altamente atenuada para coelhos mas é neuroinvasiva e estabelece infecção latente.] Pesquisa Veterinária Brasileira 31(5):389-397. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com Cepas virais mutantes defectivas em genes não essenciais se constituem em ferramentas úteis para o estudo da função de proteínas virais na biologia dos vírus. Este estudo relata uma investigação do fenótipo, em coelhos, de uma cepa recombinante do herpesvírus bovino tipo 5 (BoHV-5) defectiva na enzima timidina quinase (TK), com ênfase para a neuroinvasividade e capacidade de estabelecer e reativar a infecção latente. Coelhos inoculados com o vírus parental (SV-507/99, n=18) em baixo título (105,5TCID50) excretaram o vírus nas secreções nasais em títulos de até 104,5TCID50/mL por até 12 dias (média: 9,8 dias [5-12]) e 5/16 desenvolveram doença neurológica e morreram ou foram eutanasiados in extremis. Em contraste, coelhos inoculados com o recombinante BoHV-5TKD em alto título (107,1TCID50) excretaram o vírus em títulos inferiores (máximo 102,3TCID50/mL), por um período menor (média: 6,6 days [2-11]) e permaneceram saudáveis. A realização de PCR em seções do encéfalo no dia 6 pós-infecção (pi) revelou uma ampla distribuição do DNA do vírus parental, enquanto o DNA do vírus recombinante foi detectado apenas nos gânglios trigêmeos [TGs] e nos bulbos olfatórios [OBs]. Não obstante, durante a infecção latente (52pi), o DNA do vírus recombinante foi detectado nos TGs, OBs e em outros locais do encéfalo, demonstrando que o vírus recombinante mantém a neuroinvasividade. Tratamento com dexamethasona (Dx) no dia 65 pi resultou em reativação e excreção viral por 5/8 dos coelhos inoculados com o vírus parental (duração média de 4,2 dias [1-9]) e por nenhum dos sete coelhos inoculados com o vírus recombinante. No entanto, PCR realizado no dia 30 pós-Dx revelou a presença de DNA latente do BoHV-5TKD nos TGs, OBs e em outras áreas do encéfalo. Esses resultados confirmam que o recombinante BoHV-5TKD é altamente atenuado para coelhos. A sua capacidade de replicação na mucosa nasal é reduzida, mas mantém a capacidade de invadir o encéfalo e estabelecer infecção latente. Estudos adicionais estão em andamento para elucidar os mecanismos responsáveis pela incapacidade do recombinante de reativar a infecção latente.

Abstract in English:

ABSTRACT.- Dezengrini R., Silva S.C., Weiss M., Oliveira M.S., Traesel C.K., Weiblen R. & Flores E.F. 2010. [Effects of Foscarnet on the infection by bovine herpesviruses 1 and 5 in rabbits.] Efeitos do Foscarnet sobre a infecção pelos herpesvírus bovino tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 30(8):623-630. Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Av, Roraima 1000, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com The activity of Foscarnet (PFA) against three bovine herpesviruses (BoHVs) was previously demonstrated in cell culture. Herein we evaluated the effects of PFA on the infection and disease by BoHV-1 and BoHV-5 in a rabbit model. Rabbits inoculated with BoHV-5 in the conjunctival sac (IC) and treated with PFA (100 mg/kg/day) from day 1 to 17 post-inoculation (pi) shed less virus between days 2 and 6 pi comparing to untreated controls; this difference was significant at day 3 pi [F(9,108) = 2,23; P<0.03]. The morbidity and mortality rates of rabbits inoculated with BoHV-5 IC or intranasally (IN) were also significantly reduced in PFA-treated rabbits (50%; 11/22) comparing to untreated controls (95.4%; 21/22) (P<0.0008). In rabbits inoculated IC with BoHV-1, a reduction in virus shedding was observed in PFA-treated animals between days 1 and 4 pi; 6 and 7 pi. In addition, PFA-treated rabbits presented a longer incubation period and a shorter clinical course comparing to untreated controls (P<0.005 and P<0.04, respectively). The frequency and severity of ocular signs were also reduced in the PFA-treated group. These results demonstrate that PFA is effective against BoHV-1 and BoHV-5 in vivo and open the way towards its use in experimental therapy of herpetic infections in domestic animals.

• Antivirals BoHV-1 BoHV-5 PFA bovine herpesviruses 1 bovine herpesviruses 5 Foscarnet herpesvírus bovino tipo 1 herpesvírus bovino tipo 5

Abstract in Portuguese:

RESUMO.- Dezengrini R., Silva S.C., Weiss M., Oliveira M.S., Traesel C.K., Weiblen R. & Flores E.F. 2010. [Effects of Foscarnet on the infection by bovine herpesviruses 1 and 5 in rabbits.] Efeitos do Foscarnet sobre a infecção pelos herpesvírus bovino tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 30(8):623-630. Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Av, Roraima 1000, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com

Abstract in English:

ABSTRACT.- Vilela L.M., Del Carlo R.J., Silva J.C.P., Matta S.L.P., Rodrigues M.C.D., Monteiro B.S., Matinez M.M., Reis A.M.S., Machado D.P.D. & Lopes L.R. 2010. [Structure and cellularity of the fresh menisci (Oryctolagus cuniculus) of rabbits and the menisci preserved in glycerin.] Estrutura e celularidade de meniscos frescos de coelhos (Oryctolagus cuniculus) preservados em glicerina. Pesquisa Veterinária Brasileira 30(4):295-300. Departamento de Veterinária, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil. E-mail: ricarlo@ufv.br In the present study was evaluated the tissue architecture, the percentage of cellular population, as well as viability and distribution of cells in fresh menisci of rabbits and preserved in 98% glycerin. Were analyzed medial menisci of rabbits freshly slaughtered, which were distributed into three groups: the MF group (n=7), composed of fresh menisci, corresponded to the control group; the MG group (n=7), composed by menisci preserved in 98% glycerin, for 30 days, and the MR group (n=7) by menisci preserved in 98% glycerin and rehydrated in NaCl 0.9% for 12 hours. In all menisci were identified and quantified the different cell types: fibroblasts/fibrocytes and condrocytes. The cell population percentage was statistically similar in all groups. All menisci preserved in the MG and MR groups showed a lower intensity of color and shrinkage of collagen fibers, reduced volume and higher intensity of staining of nucleus (chromatin condensation), as compared to fresh menisci (MF), featuring the phenomenon of cell lysis. The cartilaginous matrix of preserved menisci proved to be well preserved because the tissue architecture was maintained. It was concluded that 98% glycerin is an optional preservation mean for meniscal allografts with a devitalized collagenous matrix.

• Articular cartilage meniscal allograft knee cartilagem articular aloenxerto meniscal joelho

Abstract in Portuguese:

RESUMO.- Vilela L.M., Del Carlo R.J., Silva J.C.P., Matta S.L.P., Rodrigues M.C.D., Monteiro B.S., Matinez M.M., Reis A.M.S., Machado D.P.D. & Lopes L.R. 2010. [Structure and cellularity of the fresh menisci (Oryctolagus cuniculus) of rabbits and the menisci preserved in glycerin.] Estrutura e celularidade de meniscos frescos de coelhos (Oryctolagus cuniculus) preservados em glicerina. Pesquisa Veterinária Brasileira 30(4):295-300. Departamento de Veterinária, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil. E-mail: ricarlo@ufv.br No presente estudo foi avaliada a arquitetura tecidual, a população celular, assim como a integridade e a distribuição dos tipos celulares em meniscos frescos de coelhos e preservados em glicerina 98%. Foram analisados meniscos mediais de coelhos recém abatidos, que foram distribuídos em três grupos: o grupo MF (n=7), composto por meniscos frescos, correspondeu ao grupo controle; o grupo MG (n=7), composto por meniscos preservados em glicerina 98%, por 30 dias, e o grupo MR (n=7), por meniscos preservados em glicerina 98% e reidratados em NaCl 0,9%, por 12 horas. Em todos os meniscos foram identificados e quantificados os diferentes tipos celulares: fibroblastos/fibrócitos e condrócitos. A população celular foi estatisticamente semelhante nos três grupos de meniscos, sendo que os meniscos preservados, grupos MG e MR, apresentaram menor intensidade de coloração e retração das fibras colágenas, diminuição de volume e maior intensidade de coloração dos núcleos (condensação da cromatina), em relação aos meniscos frescos (MF), caracterizando o fenômeno de lise celular. A matriz fibrocartilaginosa dos meniscos preservados revelou-se bem preservada mantendo a arquitetura tecidual dos meniscos. Conclui-se que a glicerina 98% é uma opção de meio de preservação para meniscos objetivando aloenxerto, com matriz colágena desvitalizada.

Abstract in English:

ABSTRACT.- Vilela L.M., Del Carlo R.J., Silva J.C.P., Matta S.L.P. & Reis A.M.S. 2009. [Evaluation of the collagen fibers of the fresh meniscus and the meniscuses preserved in glycerine: Experimental study in rabbits (Oryctolagus cuniculus).] Avaliação das fibras colágenas de meniscos frescos e preservados em glicerina: estudo experimental em coelhos (Oryctolagus cuniculus). Pesquisa Veterinária Brasileira 30(4):321-327. Departamento de Veterinária, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil. E-mail: ricarlo@ufv.br In the present study was evaluated the effect of 98% glycerin on the collagen fibers, tissue architecture and size of medial meniscuses of New Zealand rabbits. The animals were separated into three groups: (1) Group MF of fresh meniscus, (2) Group MG of meniscus preserved in glycerin for 30 days, and (3) Group MR of meniscus preserved in glycerin for 30 days and rehydrated in NaCl 0.9% for 12 hours. Histological sections were stained with sirius red for identification of collagen types, which were examined with a polarized light microscope. The total collagen concentration and the fiber arrangement were evaluated. Group MF presented higher Type I collagen concentration and lower Type III collagen concentration when compared with Group MG and MR. This fact is due to the water loss and consequent reduction in size and subsequent retraction of the collagen fibers of the meniscus from these groups, caused by dehydration. This may have occurred because those Type I fibers, thicker and in larger quantities, become more evident than Type III collagen fibers, which are more slender and fragile (fibrils). In the three groups studied, the collagen fibers presented themselves in a circumference form, interposed by radially oriented fibers. All of the meniscuses from Group MF presented fibers arranged obliquely, while in the treated groups, a slight disorganization of collagen fibers could be observed in some areas, what corresponds to 42.8% and 14.3% of the meniscuses, respectively. The MG group presented a significant decrease (p<0.05) in size if compared with the MF group. In the MR group, 85.7% of the meniscuses went back to the original size after rehydratation. The 98% glycerin is effective in preserving the meniscus, following rehydratation, maintaining size, structural architecture, integrity and percentage of collagen of the meniscus preserved similar to the fresh one.

• Allograft articular cartilage meniscus aloenxerto cartilagem articular menisco

Abstract in Portuguese:

RESUMO.- Vilela L.M., Del Carlo R.J., Silva J.C.P., Matta S.L.P. & Reis A.M.S. 2009. [Evaluation of the collagen fibers of the fresh meniscus and the meniscuses preserved in glycerine: Experimental study in rabbits (Oryctolagus cuniculus).] Avaliação das fibras colágenas de meniscos frescos e preservados em glicerina: estudo experimental em coelhos (Oryctolagus cuniculus). Pesquisa Veterinária Brasileira 30(4):321-327. Departamento de Veterinária, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil. E-mail: ricarlo@ufv.br No presente estudo foi avaliado o efeito da glicerina 98% sobre as fibras colágenas, arquitetura tecidual e o tamanho de meniscos mediais de coelhos da raça Nova Zelândia. Os meniscos foram separados em três grupos: (1) Grupo MF com meniscos frescos (grupo controle), (2) Grupo MG com meniscos preservados em glicerina 98% por 30 dias, e (3) Grupo MR com meniscos preservados em glicerina 98% por 30 dias e reidratados em NaCl 0,9%, por 12 horas. Os cortes histológicos foram corados com sirius red para identificação dos tipos de colágenos e observados em microscópio de luz polarizada, avaliando-se a concentração total de colágeno Tipo I e III e a disposição das fibras. Os meniscos frescos apresentaram significativamente maior concentração de fibras colágenas Tipo I e menor concentração de fibras colágenas Tipo III que os meniscos preservados (MG e MR); isto ocorreu devido à perda de água e conseqüente redução do tamanho dos meniscos e retração das fibras colágenas dos meniscos dos Grupos MG e MR; isto pode ter feito com que as fibras Tipo I, mais espessas e em maior quantidade, se tornassem mais evidentes do que as fibras colágenas Tipo III, que são mais delgadas e frágeis (fibrilas). Nos três grupos estudados, as fibras colágenas apresentaram-se de forma circunferencial, interpostas por fibras orientadas radialmente. Entretanto, nos grupos tratados (MG e MR) foi observado, em pequenas áreas, leve desorganização das fibras colágenas, o que correspondeu a 42,8% e 14,3% dos meniscos, respectivamente. O grupo de meniscos em glicerina apresentou redução significativa (p<0,05) no tamanho em relação ao Grupo MF. No Grupo MR, 85,7% dos meniscos retornaram ao seu tamanho inicial após a reidratação. A glicerina 98% é eficaz na preservação de meniscos, mantendo o tamanho, a arquitetura estrutural, a integridade e percentagem do colágeno dos meniscos preservados semelhante à de meniscos frescos, desde que sejam reidratados em NaCl 0,9% após preservação.

Abstract in English:

RESUMO.- Peixoto P.V., Klem M.A.P., Brito M.F., Duarte V.C., & França T.N. 2010. [Toxicological, clinic-pathological and ultrastructural aspects of iatrogenic and experimental poisoning by vitamin D in rabbits.] Aspectos toxicológico, clínico-patológico e ultraestrutural das intoxicações iatrogênica e experimental por vitamina D em coelhos. Pesquisa Veterinária Brasileira 30(3):277-288. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: peixotop@ufrrj.br São descritos aspectos toxicológicos, clínico-patológicos e ultraestruturais de coelhos intoxicados iatrogênica e experimentalmente por vitamina D por via subcutânea. Clinicamente, os animais evidenciaram sinais de insuficiência cardiovascular como ascite e edema pulmonar, hiporexia, anorexia, diarréia mucosa, emagrecimento e apatia. As clássicas alterações de mineralização e, por vezes, osseificação, do sistema cardiovascular, bem como as alterações de rins, pulmões, estômago, entre outros órgãos, foram reproduzidas com administrações subcutâneas de solução oleosa de colecalciferol (vitamina D3 não-ativada).

• Iatrogenic poisoning vitamin D poisoning hypervitaminosis D

Abstract in Portuguese:

ABSTRACT.- Peixoto P.V., Klem M.A.P., Brito M.F., Duarte V.C., & França T.N. 2010. [Toxicological, clinic-pathological and ultrastructural aspects of iatrogenic and experimental poisoning by vitamin D in rabbits.] Aspectos toxicológico, clínico-patológico e ultraestrutural das intoxicações iatrogênica e experimental por vitamina D em coelhos. Pesquisa Veterinária Brasileira 30(3):277-288. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: peixotop@ufrrj.br Toxicological, clinic-pathological and ultrastructural aspects of iatrogenic and experimental subcutaneous poisoning in rabbits by vitamin D are described. Clinically the animals showed signs of cardiovascular insufficiency, as ascite and lung edema, hyporexia, anorexia, mucous diarrhoea, loss of weight and apathy. The classical alterations of minera-lization and, occasionally, ossification of the cardiovascular system, as well the lesions of kidneys, lungs, stomach, among other organs, were reproduced by the subcutaneous administration of an oily solution of cholecalciferol (non-activated vitamin D3).

Abstract in English:

ABSTRACT.- Nunes Rangel M.F., Lemos L.S., Almeida C.M.C., Sales L.G. & Vieira-da-Motta O. 2010. Development of Polyclonal IgY antibodies in chickens and IgG in rabbits immunized against proteins of Pythium insidiosum isolated from horses in the state of Rio de Janeiro. Pesquisa Veterinária Brasileira 30(1):87-93. Micologia Veterinária do Setor de Doenças Infectocontagiosas, Laboratório de Sanidade Animal do Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego 2000, Horto, Campos dos Goytacazes, RJ 28013-602, Brazil. E-mail: olney@uenf.br Pythiosis is caused by Pythium insidiosum and the occurrence of disease in horses was described in the North and Northwest State of Rio de Janeiro, Brazil. The disease was described in cattle, sheep, humans, and horses in different states and regions across the country. This paper describes the development of IgY and IgG polyclonal antibodies, in chicken and rabbits, respectively against proteins extracted from kunkers and hyphae of P. insidiosum from affected horses. The proteins were recognized by chicken, rabbit and horse antibodies by immunodiffusion and Western blot against majority bands of 27 and 43 KDa, and titrated by ELISA. The antibodies IgY developed by the first time against Brazilian strains of P. insidiosum may represent a valuable tool in the detection of antigens of the pathogen and contribute to further studies aimed at immunotherapy and knowledge about this disease in endemic areas in Rio de Janeiro and in Brazil.

• Pythiosis Pythium insidiosum

Abstract in Portuguese:

RESUMO.- Nunes Rangel M.F., Lemos L.S., Almeida C.M.C., Sales L.G. & Vieira-da-Motta O. 2010. Development of Polyclonal IgY antibodies in chickens and IgG in rabbits immunized against proteins of Pythium insidiosum isolated from horses in the state of Rio de Janeiro. [Desenvolvimento de Anticorpos IgY em galinhas e IgG em coelhos imunizados contra proteínas de Pythium insidiosum isolado de equinos no Estado do Rio de Janeiro, Brasil.] Pesquisa Veterinária Brasileira 30(1):87-93. Micologia Veterinária do Setor de Doenças Infectocontagiosas, Laboratório de Sanidade Animal do Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego 2000, Horto, Campos dos Goytacazes, RJ 28013-602, Brazil. E-mail: olney@uenf.br Pitiose é causada por Pythium insidiosum e a doença foi descrita em equinos no Norte e Noroeste do Estado do Rio de Janeiro, Brasil. A doença foi descrita em bovinos, ovelhas, humanos e cavalos em diferentes estados e regiões do país. Este trabalho descreve o desenvolvimento de anticorpos policlonais, IgY e IgG, em galinha e coelho, respectivamente, contra proteínas extraídas de kunkers e hifas de P. insidiosum de cavalos doentes. As proteínas foram reconhecidas por anticorpos de galinha, coelho e cavalos contra as bandas majoritárias de 27 e 34 KDa em imunodifusão e Western blot tituladas por ELISA. Os anticorpos IgY desenvolvidos pela primeira vez contra cepas brasileiras de P. insidiosum podem representar um valioso instrumento na detecção de antígenos de patógenos e contribuem para novos estudos baseados na imunoterapia e no entendimento sobre esta doença em áreas endêmicas no Rio de Janeiro e em todo o país.

Abstract in English:

ABSTRACT.- Silva A.D., Franco A.C., Esteves P.A., Spilki F.R. & Roehe P.M. 2009. Experimental infection of rabbits with a recombinant bovine herpesvirus type 5 (BoHV-5) gI, gE and US9-negative. Pesquisa Veterinária Brasileira 29(11):913-918. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro Saúde Animal, Estrada Municipal do Conde 6000, Caixa Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: anafranco.ufrgs@gmail.com Bovine herpesvirus type 5 (BoHV-5) is a major cause of viral meningoencephalitis in cattle. The expression of different viral proteins has been associated with BoHV-5 neuropathogenesis. Among these, gI, gE and US9 have been considered essential for the production of neurological disease in infected animals. To evaluate the role of gI, gE and US9 in neurovirulence, a recombinant from which the respective genes were deleted (BoHV-5 gI-/gE-/US9-) was constructed and inoculated in rabbits of two age groups (four and eight weeks-old). When the recombinant virus was inoculated through the paranasal sinuses of four weeks-old rabbits, neurological disease was observed and death was the outcome in 4 out of 13 (30.7 %) animals, whereas clinical signs and death were observed in 11/13 (84.6%) of rabbits infected with the parental virus. In eight weeks-old rabbits, the BoHV-5 gI-/gE-/US9- did not induce clinically apparent disease and could not be reactivated after dexamethasone administration, whereas wild type BoHV-5 caused disease in 55.5% of the animals and was reactivated. These findings reveal that the simultaneous deletion of gI, gE and US9 genes did reduce but did not completely abolish the neurovirulence of BoHV-5 in rabbits, indicating that other viral genes may also play a role in the induction of neurological disease.

• Herpesvírus bovino tipo 5 BoHV-5

Abstract in Portuguese:

RESUMO.- Silva A.D., Franco A.C., Esteves P.A., Spilki F.R. & Roehe P.M. 2009. Experimental infection of rabbits with a recombinant bovine herpesvirus type 5 (BoHV-5) gI, gE and US9-negative. Pesquisa Veterinária Brasileira 29(11):913-918. Instituto de Pesquisas Veterinárias Desidério Finamor, Fepagro Saúde Animal, Estrada Municipal do Conde 6000, Caixa Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: anafranco.ufrgs@gmail.com O herpesvírus bovino tipo 5 é uma das principais causas de meningoencefalite viral em bovinos. A expressão de diferentes proteínas virais tem sido associada à neuropatogenia do BoHV-5. Entre estas, a gI, gE e US9 têm sido consideradas essenciais para a indução de sinais neurológicos nos animais infectados. Para avaliar o papel das proteínas gI, gE e US9 na neurovirulência, construiu-se um recombinante no qual os genes que codificam estas proteínas foram deletados, denominado BoHV-5 gI-/gE-/US9-. Este vírus foi inoculado em coelhos de idades diferentes (quatro e oito semanas de idade). Quando o vírus recombinante foi inoculado nos seios paranasais de coelhos de quatro semanas de idade, doença neurológica e morte foram observadas em 4 dos 13 (30,7 %) animais, enquanto que sinais clínicos e morte foram observados em 11/13 (84,6%) dos coelhos infectados com o vírus parental. Em coelhos de oito semanas de idade, o BoHV-5 gI-/gE-/US9- não induziu sinais clínicos aparentes e, após tentativa de reativação viral por tratamento com dexametasona, o vírus não foi re-excretado. Por outro lado, o vírus selvagem causou doença clínica em 55,5 % dos coelhos e foi re-excretado após tratamento com dexametasona. Estes achados revelam que a deleção simultânea dos genes gI, gE e US9 reduziu mas não aboliu completamente a neurovirulência do BoHV-5 em coelhos, indicando que outros genes virais possam ter papel na indução da doença neurológica.

Abstract in English:

ABSTRACT.- Helayel M.A., França T.N., Seixas J.N., Nogueira V.A., Caldas S.A. & Peixoto P.V. 2009. [Sudden death in cattle caused by ingestion of Pseudocalymma elegans (Bignoniaceae) in the county of Rio Bonito, Rio de Janeiro.] Morte súbita em bovinos causada pela ingestão de Pseudocalymma elegans (Bignoniaceae) no município de Rio Bonito, RJ. Pesquisa Veterinária Brasileira 29(7):498-508. Curso de Pós-Graduação em Medicina Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: michel_abdallavet@yahoo.com.br Natural poisoning by Pseudocalymma elegans, a plant that causes “sudden death” and only occurs in the State of Rio de Janeiro, is described in a cow. This condition was experimentally reproduced in three calves and three rabbits with the plant collected in the area where the deaths had occurred. Postmortem and histopathological examinations of the natural case in the cow did not reveal significant alterations. Oral administration of 1g/kg of the sprouts of P. elegans caused death of the calf 5 hours and 30 minutes after beginning of the administration. The dose of 0.5 g/kg caused death of another calf with onset of symptoms after 3 hours and 24 minutes and a course of 73 hours and 12 minutes. Animals that ingest borderline doses may show a longer course with a characteristic clinical picture of heart impairment. The dose of 0.25g/kg did not cause death, but only clinical signs. Heart palpitation and arrhythmia, increase of breathing frequency, reluctance in moving, positive venous pulse, ingurgitated jugular veins, falling down and peddling movements shortly before death, were observed. At postmortem examination the lesions were those of acute heart insufficiency, and histopathological examination revealed the typical kidney lesion (hydropic-vacular degeneration in the distal convoluted tubules) seen in poisoning by plants that cause “sudden death”. In the experimentally poisoned rabbits the clinical course was less than 1-2 minutes. In the kidney of two rabbits there was also the characteristic microscopic lesion. The presence of the plant in the county of Rio Bonito had not been known by the veterinarians. It is concluded that the plant could be more toxic than described before.

• Poisonous plants Pseudocalymma elegans Bignoniaceae plant poisoning sudden death cattle rabbits

Abstract in Portuguese:

RESUMO.- Helayel M.A., França T.N., Seixas J.N., Nogueira V.A., Caldas S.A. & Peixoto P.V. 2009. [Sudden death in cattle caused by ingestion of Pseudocalymma elegans (Bignoniaceae) in the county of Rio Bonito, Rio de Janeiro.] Morte súbita em bovinos causada pela ingestão de Pseudocalymma elegans (Bignoniaceae) no município de Rio Bonito, RJ. Pesquisa Veterinária Brasileira 29(7):498-508. Curso de Pós-Graduação em Medicina Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: michel_abdallavet@yahoo.com.br Descreve-se a intoxicação natural por Pseudocalymma elegans em pelo menos um bovino em Rio Bonito, RJ e a reprodução experimental dessa intoxicação em três bovinos e em 3 coelhos com exemplares dessa planta colhida no local onde ocorreu a morte. Necropsia e histopatologia do bovino naturalmente intoxicado não revelaram alterações significativas. A administração, por via oral, de 1g/kg da brotação da planta causou a morte do bovino dentro de 5h e 30 minutos após o início da administração, já pela administração de 0,5 g/kg, a morte do animal ocorreu após 76 horas e 36 minutos. A dose de 0,25g/kg foi capaz de causar sintomas, mas não levou a morte. A sintomatologia caracterizou-se por arritmia cardíaca, taquicardia, aumento da freqüência respiratória, relutância em se mover, pulso venoso positivo, jugulares e grandes vasos ingurgitados, queda ao solo e movimentos de pedalagem, seguindo-se o óbito. À necropsia foram verificadas alterações compatíveis com às observadas na insuficiência cardíaca aguda, e o exame histopatológico revelou a lesão renal típica (degeneração hidrópica em túbulos contornados distais) de intoxicação por plantas que causam “morte súbita”. Nos coelhos, a evolução variou entre menos de um minuto a dois minutos. O exame histopatológico do rim de dois coelhos também revelou a lesão microscópica característica. Essa planta ainda não havia sido mapeada nessa área do Estado do Rio de Janeiro. Conclui-se que a planta pode ser mais tóxica do que anteriormente descrito.

Abstract in English:

ABSTRACT.- Sampaio R.S., Lacerda M.S., Oliveira P.C.L., Paneto J.C.C., Bittar E.R., Borges G.A., Camacho G.M.M. & Braga E.M. 2009. [Variation of the resistance force to the micro-traction of fragments of cortical bones preserved in several means and fresh: Experimental study in rabbits.] Variação da força de resistência à micro-tração de fragmentos de ossos corticais preservados e a fresco: estudo experimental em coelhos. Pesquisa Veterinária Brasileira 29(4):345-352. Instituto de Estudos Avançados em Veterinária “José Caetano Borges”, Universidade de Uberaba, Av. Afrânio Azevedo 2140, Bairro Olinda, Uberaba, MG 38020-450, Brazil. E-mail: relisampa@terra.com.br Due to the increasing use of cortical bone allografts in orthopedic surgeries, de knowledge of its biomechanics characteristics during preservation time is needed. The present study consisted in the analyses of the resistance power to the micro-traction of samples of rabbit cortical bones preserved in several means for up to 180 days and fresh. The results showed that the resistance and the preservation time presented an inversely proportional relation, meaning that, the longer the time of preservation, the shorter the physical resistance evaluated in the biomechanical rehearsal of resistance to the micro-traction. The glycerin has presented lower values in relation to the resistance test, showing, after 30 days, only 24.58% of the present power in the fresh bone, and by 180 days, 1.76%. The samples submitted to autoclavation also showed low values by the end of the experiment, while they remained with just 12.31% of the power present in the fresh bone. The bones preserved in homologous plasma, Dakin liquid and the ones cryopreserved showed the best levels of resistance at the end of the experiment, remaining, respectively with 82.47, 70.34 and 66.72% of the maximum power, while compared with the resistance of the fresh bones. The conclusion is that the choice of methodology and time of preservation interfered directly in the biomechanics of the cortical bones, promoting decrease of the resistance capacity to the traction along the period of preservation.

• Bone graft bone preservation bone resistance bone micro-traction rabbits

Abstract in Portuguese:

ABSTRACT.- Sampaio R.S., Lacerda M.S., Oliveira P.C.L., Paneto J.C.C., Bittar E.R., Borges G.A., Camacho G.M.M. & Braga E.M. 2009. [Variation of the resistance force to the micro-traction of fragments of cortical bones preserved in several means and fresh: Experimental study in rabbits.] Variação da força de resistência à micro-tração de fragmentos de ossos corticais preservados e a fresco: estudo experimental em coelhos. Pesquisa Veterinária Brasileira 29(4):345-352. Instituto de Estudos Avançados em Veterinária “José Caetano Borges”, Universidade de Uberaba, Av. Afrânio Azevedo 2140, Bairro Olinda, Uberaba, MG 38020-450, Brazil. E-mail: relisampa@terra.com.br Due to the increasing use of cortical bone allografts in orthopedic surgeries, de knowledge of its biomechanics characteristics during preservation time is needed. The present study consisted in the analyses of the resistance power to the micro-traction of samples of rabbit cortical bones preserved in several means for up to 180 days and fresh. The results showed that the resistance and the preservation time presented an inversely proportional relation, meaning that, the longer the time of preservation, the shorter the physical resistance evaluated in the biomechanical rehearsal of resistance to the micro-traction. The glycerin has presented lower values in relation to the resistance test, showing, after 30 days, only 24.58% of the present power in the fresh bone, and by 180 days, 1.76%. The samples submitted to autoclavation also showed low values by the end of the experiment, while they remained with just 12.31% of the power present in the fresh bone. The bones preserved in homologous plasma, Dakin liquid and the ones cryopreserved showed the best levels of resistance at the end of the experiment, remaining, respectively with 82.47, 70.34 and 66.72% of the maximum power, while compared with the resistance of the fresh bones. The conclusion is that the choice of methodology and time of preservation interfered directly in the biomechanics of the cortical bones, promoting decrease of the resistance capacity to the traction along the period of preservation.

Abstract in English:

ABSTRACT.- Flores E.F., Weiblen R, Vogel F.S.F., Dezengrini R., Almeida S.R., Spilki F.R. & Roehe P.M. 2009. [Experimental neuropathogenesis of bovine herpesvirus 5 infection in rabbits.] Neuropatogênese experimental da infecção pelo herpesvírus bovino tipo 5 em coelhos. Pesquisa Veterinária Brasileira 29(1):1-16. Departamento de Medicina Veterinária Preventiva. Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS. Brazil. E-mail: eduardofurtadoflores@gmail.com Several aspects of the biology of bovine herpesvirus 5 (BoHV-5) have been studied in rabbits, which develop acute infection and neurological disease upon experimental inoculation. The acute infection is followed by the establishment of latent infection, which can be naturally or artificially reactivated. The first experiments in rabbits established a protocol for virus inoculation and monitoring the infection, and characterized the main virological, clinical and pathological aspects of the acute infection. The pathogenesis of acute infection, from the initial viral replication at site of inoculation, pathways and kinetics of viral transport to the brain, distribution and virus replication in the central nervous system (CNS), cellular and tissue tropism, clinical signs and CNS pathology have been extensively studied using this animal model. Subsequently, several biological and molecular aspects of latent BoHV-5 infection have also been elucidated upon inoculation of rabbits. Rabbits have also been used to investigate the phenotype (neuroinvasiveness, neurogrowth) of field isolates and recombinant vaccine candidates, protection by passive immunity, vaccine protection, the efficacy of anti-viral drugs and support therapies for neurological disease. This animal model was also used to investigate the origin and distribution of electric impulses involved in seizures - a hallmark of BoHV-5 induced neurological infection - and also to test the efficacy of anti-convulsivants. In spite of the possible differences between rabbits and cattle - the natural host of the virus - the observations taken from this experimental model have greatly contributed to the knowledge of the biology of BoHV-5 infection. The present article presents a review of the main published and unpublished results and observations by our group, comprising more than a decade of studies on the pathogenesis of BoHV-5 infection in the rabbit model.

• Bovine herpesvirus 5 BoHV-5 rabbits experimental model

Abstract in Portuguese:

ABSTRACT.- Flores E.F., Weiblen R, Vogel F.S.F., Dezengrini R., Almeida S.R., Spilki F.R. & Roehe P.M. 2009. [Experimental neuropathogenesis of bovine herpesvirus 5 infection in rabbits.] Neuropatogênese experimental da infecção pelo herpesvírus bovino tipo 5 em coelhos. Pesquisa Veterinária Brasileira 29(1):1-16. Departamento de Medicina Veterinária Preventiva. Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS. Brazil. E-mail: eduardofurtadoflores@gmail.com Several aspects of the biology of bovine herpesvirus 5 (BoHV-5) have been studied in rabbits, which develop acute infection and neurological disease upon experimental inoculation. The acute infection is followed by the establishment of latent infection, which can be naturally or artificially reactivated. The first experiments in rabbits established a protocol for virus inoculation and monitoring the infection, and characterized the main virological, clinical and pathological aspects of the acute infection. The pathogenesis of acute infection, from the initial viral replication at site of inoculation, pathways and kinetics of viral transport to the brain, distribution and virus replication in the central nervous system (CNS), cellular and tissue tropism, clinical signs and CNS pathology have been extensively studied using this animal model. Subsequently, several biological and molecular aspects of latent BoHV-5 infection have also been elucidated upon inoculation of rabbits. Rabbits have also been used to investigate the phenotype (neuroinvasiveness, neurogrowth) of field isolates and recombinant vaccine candidates, protection by passive immunity, vaccine protection, the efficacy of anti-viral drugs and support therapies for neurological disease. This animal model was also used to investigate the origin and distribution of electric impulses involved in seizures - a hallmark of BoHV-5 induced neurological infection - and also to test the efficacy of anti-convulsivants. In spite of the possible differences between rabbits and cattle - the natural host of the virus - the observations taken from this experimental model have greatly contributed to the knowledge of the biology of BoHV-5 infection. The present article presents a review of the main published and unpublished results and observations by our group, comprising more than a decade of studies on the pathogenesis of BoHV-5 infection in the rabbit model.