PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Pedroso P.M.O., Pescador C.A., Bandarra P.M., Raymundo D.L., Borba M.R., Wouters F., Bezerra Jr P.S. & Driemeier D. 2008. [Standardization of immunohistochemistry technique for detection of rabies virus in formalin-fixed and paraffin-embedded tissue samples from central nervous system of cattle.] Padronização da técnica de imuno-histoquímica para raiva em amostras de tecido do sistema nervoso central de bovinos fixadas em formol e emblocadas em parafina. Pesquisa Veterinária Brasileira 28(12):627-632. Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br For standardization of the rabies immunohistochemistry technique, five samples of central nervous system (CNS) of cattle naturally infected with rabies virus were examined. One polyclonal antibody and two monoclonal antibodies were used. The following reagents were evaluated for antigen retrieval: XIV protease, proteinase K and citrate buffer (pH 6.0) boiling at 100°C during 15 minutes in bain-marie. Detection of rabic antigen was possible with the three antibodies tested. The polyclonal antibody was superior to the monoclonal antibodies, demonstrating good results with the three antigen retrieval protocols. The highest intensity staining was obtained with the citrate buffer and heat. The immunohistochemistry technique demonstrated the presence of viral antigens in the cytoplasm of neurons, in form of aggregates or with round or oval shape. The antigens were found as single or multiples inclusion bodies in the neurons. Immunohistochemistry is a fast method that can be used in routine procedures in cases where rabies is suspected, especially when the brain is submitted to the laboratory as formalin-fixed fragments or when samples could not be immediately shipped. The technique is also useful for retrospective studies.

• Diseases of cattle infectious diseases diseases of the central nervous system rabies immunohistochemistry standardization

Abstract in Portuguese:

ABSTRACT.- Pedroso P.M.O., Pescador C.A., Bandarra P.M., Raymundo D.L., Borba M.R., Wouters F., Bezerra Jr P.S. & Driemeier D. 2008. [Standardization of immunohistochemistry technique for detection of rabies virus in formalin-fixed and paraffin-embedded tissue samples from central nervous system of cattle.] Padronização da técnica de imuno-histoquímica para raiva em amostras de tecido do sistema nervoso central de bovinos fixadas em formol e emblocadas em parafina. Pesquisa Veterinária Brasileira 28(12):627-632. Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br For standardization of the rabies immunohistochemistry technique, five samples of central nervous system (CNS) of cattle naturally infected with rabies virus were examined. One polyclonal antibody and two monoclonal antibodies were used. The following reagents were evaluated for antigen retrieval: XIV protease, proteinase K and citrate buffer (pH 6.0) boiling at 100°C during 15 minutes in bain-marie. Detection of rabic antigen was possible with the three antibodies tested. The polyclonal antibody was superior to the monoclonal antibodies, demonstrating good results with the three antigen retrieval protocols. The highest intensity staining was obtained with the citrate buffer and heat. The immunohistochemistry technique demonstrated the presence of viral antigens in the cytoplasm of neurons, in form of aggregates or with round or oval shape. The antigens were found as single or multiples inclusion bodies in the neurons. Immunohistochemistry is a fast method that can be used in routine procedures in cases where rabies is suspected, especially when the brain is submitted to the laboratory as formalin-fixed fragments or when samples could not be immediately shipped. The technique is also useful for retrospective studies.

Abstract in English:

ABSTRACT.- Peixoto P.V., Ribeiro C.T., Bezerra Jr P.S., Driemeier D. & França T.N. 2008. Proliferative enteropathy (Lawsonia intracellularis) outbreak in rabbits in Brazil. Pesquisa Veterinária Brasileira 28(10):447-451. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br An outbreak of Lawsonia intracellularis infection in rabbits, which occurred in 1988 in Rio de Janeiro state, Brazil, is reported. The disease had an acute course (24-48 hours) with clinical signs characterized by brownish or green diarrhea and dehydration. Occasionally, the animals died one day after the onset of diarrhea, without showing any other clinical signs. At necropsy, the ileum was prominent, firm and had a thickened wall; it was dilated in the caudal direction and had a somewhat reticulated appearance, perceptible through the serosa. The thickened mucous membrane had finely corrugated aspect and a shiny surface. The ileocecal valve and surrounding areas were slightly edematous and irregular. The Peyer’s patches were sometimes more evident. There was moderate enlargement of the mesenteric lymph nodes. The histological examination revealed different degrees of hyperplasia of the epithelial cells of intestinal crypts consisting of poorly differentiated, hyperchromatic cells with high mitotic index, arranged in a pseudostratified layer which, in some cases, reached the apical portions of the villi. The inflammatory infiltrate between the hyperplastic epithelial cells was composed of lymphocytes, plasma cells, macrophages, some eosinophils and globular leukocytes. Silver impregnation revealed large numbers of bacteria with morphology of the genus Lawsonia in the apical pole of cryptal enterocytes. These bacteria reacted positively to a Lawsonia intracellularis polyclonal antibody by the avidin-biotin immunohistochemistry method.

• Lawsonia intracellularis proliferative enteropathy rabbits Brazil

Abstract in Portuguese:

ABSTRACT.- Peixoto P.V., Ribeiro C.T., Bezerra Jr P.S., Driemeier D. & França T.N. 2008. Proliferative enteropathy (Lawsonia intracellularis) outbreak in rabbits in Brazil. Pesquisa Veterinária Brasileira 28(10):447-451. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br An outbreak of Lawsonia intracellularis infection in rabbits, which occurred in 1988 in Rio de Janeiro state, Brazil, is reported. The disease had an acute course (24-48 hours) with clinical signs characterized by brownish or green diarrhea and dehydration. Occasionally, the animals died one day after the onset of diarrhea, without showing any other clinical signs. At necropsy, the ileum was prominent, firm and had a thickened wall; it was dilated in the caudal direction and had a somewhat reticulated appearance, perceptible through the serosa. The thickened mucous membrane had finely corrugated aspect and a shiny surface. The ileocecal valve and surrounding areas were slightly edematous and irregular. The Peyer’s patches were sometimes more evident. There was moderate enlargement of the mesenteric lymph nodes. The histological examination revealed different degrees of hyperplasia of the epithelial cells of intestinal crypts consisting of poorly differentiated, hyperchromatic cells with high mitotic index, arranged in a pseudostratified layer which, in some cases, reached the apical portions of the villi. The inflammatory infiltrate between the hyperplastic epithelial cells was composed of lymphocytes, plasma cells, macrophages, some eosinophils and globular leukocytes. Silver impregnation revealed large numbers of bacteria with morphology of the genus Lawsonia in the apical pole of cryptal enterocytes. These bacteria reacted positively to a Lawsonia intracellularis polyclonal antibody by the avidin-biotin immunohistochemistry method.

Abstract in English:

ABSTRACT.- Néspoli P.B., Duarte M.D., Bezerra Jr P.S., Döbereiner J. & Peixoto P.V. 2001.[Clinical and pathological aspects of experimental poisoning by sodium selenite in horses] Aspectos clínico-patológicos da intoxicação experimental por selenito de sódio em eqüinos. Pesquisa Veterinária Brasileira 21(3):109-116. Depto Clínica Médica Veterinária, Universidade Federal de Mato Grosso, Av. Fernando Correa s/nº, Cuiabá, MT 78065-200, Brazil. E-mail: peixotop@ufrrj.br Due to the numerous contradictions on selenium poisoining, and in arder to improve knowledge about the clinical, pathological and toxicological aspects, experiments were performed with intramuscular injections of sodium selenite in 9 horses. Peracute, acute, subacute and chronic poisoning was reproduced; some nervous symptoms observed in acute cases were similar to those described for "blind staggers". In spite of this, the conflicting and dubious feature of this formerly described disease tums very difficult any comparison. On the other hand, the chronic poisoning was the first experimental reproduction of "alkali disease" by the parenteral route in horses. When administered as one injection, the lethal dose for sodium selenite was 1.49 mg/kg. Various clinical and pathological observations regarding the cardiovascular and nervous system, not previously mentioned in the literature for horses, are described. There have to be mentioned especially, (1) as to clinical aspects, cardiac murmurs, arrythmia, splitting of the heart sounds and convulsions, (2) regarding post-mortem findings, flattening of the cerebral gyri and increase of the liquor, and (3) conceming histopathology, lysis and necrosis of neurons in the cortex, oedema of astrocytes, as well as activation of endothelial and glia cells. It is suggested, that the degenerative-necrotic alterations in the central nervous system could be due to the oedema caused by an increase in vascular permeability through the action of the selenite.

• Selenium sodium selenite poisoning horses clinics pathology Selênio selenito de sódio intoxicação eqüinos clínica patologia.

Abstract in Portuguese:

SINOPSE.- Néspoli P.B., Duarte M.D., Bezerra Jr P.S., Döbereiner J. & Peixoto P.V. 2001.[Clinical and pathological aspects of experimental poisoning by sodium selenite in horses] Aspectos clínico-patológicos da intoxicação experimental por selenito de sódio em eqüinos. Pesquisa Veterinária Brasileira 21(3):109-116. Depto Clínica Médica Veterinária, Universidade Federal de Mato Grosso, Av. Fernando Correa s/nº, Cuiabá, MT 78065-200, Brazil. E-mail: peixotop@ufrrj.br Dadas as controvérsias sobre a intoxicação por selênio, foram realizados nove experimentos com a administração de selenita de sódio, por via intramuscular, em eqüinos, com o intuito de estudar e melhor fundamentar os aspectos clínico-patológicos e toxicológicos sobre esse tema. Conseguiram-se produzir quadros com evoluções supiraguda, aguda, subaguda e crônica; alguns sinais clínicos de origem nervosa observados nos quadros agudos foram similares aos descritos para "blind staggers"; a despeito disto, o carácter conflitante e duvidoso das descrições sobre essa pretensa entidade historicamente descrita, não permite uma comparação mais exata. O quadro crônico, por outro lado, configurou claramente a primeira reprodução de "alkali disease", por via parenteral, em eqüinos. Estabeleceu-se 1,49 mg/kg de selenito de sódio como a dose única letal para essa espécie. Descrevem-se diversos achados clínico-patológicos relativos aos sistemas cardiovascular e nervoso, antes não mencionados na literatura relativa aos eqüinos intoxicados por selênio. Entre eles, destacam-se, clinicamente, sopro e arritmia cardíacos, desdobramento de bulhas e convulsão. À necropsia, um animal apresentou nítido achatamento das circunvoluções cerebrais e, em relação à histopatologia, lise e necrose de neurônios do córtex, edema de astrócitos, bem como ativação endotelial e gliose. Em relação à patogénese, postula-se que as alterações degenerativo-necróticas observadas no sistema nervoso central, devam-se ao edema, por sua vez consequente ao aumento da permeabilidade vascular, determinada pelo selenito de sódio.

Abstract in English:

ABSTRACT.- Bezerra Jr P.S., Ilha M.R.S., Langohr I.M. & Barros C.S.L. 2000. [Experimental monensin poisoning in horses.] Intoxicação experimental por monensina em eqüinos. Pesquisa Veterinária Brasileira 20(3):102-108. Depto Patologia, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. E-mail: cslb@sm.conex.com.br Seven horses were experimentally treated with sodium monensin. Two of them were fed 3-4 kg/horse/daywith a commercial ration (containing 180 ppm±20) known to be implicated in natural outbreaks of monensin poisoning in horses. A third horse was fed a single dose of 5 mg/kg and another one received four daily doses of 1 mg/kg of sodium monensin (from a premix source). These four horses died or were euthanitised in extremis 3-8 days after the beginning of administration of the drug. A fifth horse was fed a single dose of 5 mg/kg of monensin, became mildly ill but recovered. Two experimental horses did not develop signs of the toxicosis. One of them was fed 40 daily doses of 0.5 mg/kg of monensin. The other was fed 3 kg/day of the sarne brand of ration used in farms where outbreaks of monensin poisoning in horses have been reported (but from another batch later determined to have monensin leve Is of only < 5 ppm). The onset of clinical signs varied from 2 to 5 days after administration of the drug, and clinical courses lasted from 24 to 76 hours. Clinical signs included tachycardia and cardiac arythmia, groaning, incoordination, sudoresis, sternal or lateral recumbency, paddling and death. Ma.rked increases in the plasmatic activity of creatine phosphokinase were observed in five poisoned horses, and a mild increase in the aspartate aminotransferase plasmatic activity was detected in one of the animals. Main necropsy findings were in the skeletal muscles and consi_sted of focal to focally extensive white or yellow areas of discoloration with bilateral symmetric distribution. These lesions were associated with gelatinous transluscent edema in the intermuscülar fasciae. More intensively affected muscles included quadriceps femoris, adductor, pectineus, gracilis, semimembranous, supraspinatus, subscapularis and brachycephalic. Histopathological findings consisted of segmentar, multifocal to coalescent, degenerative myopathy. Both gross and microscopic lesions were absent in the skeletal muscles from two of the horses fed the monensin premix [5 mg/kg (single dose) and 4 mg/kg (four daily doses of 1 mg/kg)]. Neither gross nor microscopic lesions were observed in the myoéardium of any of these horses.

• Ionophore antibiotics monensin disease of horses pathology myopathy Antibióticos ionóforos monensina doenças de eqüinos patologia miopatia.

Abstract in Portuguese:

RESUMO.- Bezerra Jr P.S., Ilha M.R.S., Langohr I.M. & Barros C.S.L. 2000. [Experimental monensin poisoning in horses.] Intoxicação experimental por monensina em eqüinos. Pesquisa Veterinária Brasileira 20(3):102-108. Depto Patologia, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. E-mail: cslb@sm.conex.com.br Sete eqüinos foram tratados experimentalmente com monensina sódica. Dois desses animais receberem 3-4 kg/eqüino/dia de uma ração comercial sabidamente implicada em surtos naturais da intoxicação por monensina em equinos e que continha 180 ppm±20 da droga. Um eqüino recebeu uma única dose de 5 mg/kg e um outro recebeu 4 doses diárias de 1 mg/kg de monensina sódica originária de um premix. Esses quatro eqüinos morreram ou foram sacrificados in extremis, 3-8 dias após o início da administração da droga. Um quinto eqüino recebeu dose única de 5 mg/kg de monensina, ficou levemente doente e se recuperou. Dois eqüinos não desenvolveram sinais da intoxicação. Um desses eqüinos tinha recebido 40 doses diárias de 0,5 mg/kg de monensina e o outro recebeu 3 kg/dia de uma ração da mesma marca que a usada nas fazendas onde surtos de intoxicação por monensina foram detectados (mas de uma outra partida, mais tarde determinada como contendo menos de 5 ppm de monensina). O aparecimento dos sinais clínicos ocorreu de 2 a 5 dias após a administração da droga e a duração do quadro clínico variou de 24 a 76 horas. Os sinais clínicos incluíam taquicardia, arritmia, gemidos, incoordenação, sudorese, decúbito esternal, decúbito lateral, pedaleios e morte. Em cinco dos eqüinos intoxicados observaram-se marcadas elevações da atividade plasmática de creatina fosfoquinase e, em um eqüino, houve leve aumento da atividade plasmática de aspartato aminotransferase. Os principais achados de necropsia consistiram em áreas brancas ou amarelas, focais ou focalmente extensas e bilateralmente simétricas nos músculos esqueléticos. Essas lesões eram associadas a edema gelatinoso e translúcido das fáscias intermusculares. Quadríceps femoral, adutor, pectíneo, grácil, semimembranáceo, supra-espinhal, subescapular, braquicefálico e quadríceps femoral estavam entre os músculos esqueléticos mais afetados. Os exames histológicos revelaram miopatia segmentar, multifocal a coalescente. Em dois eqüinos que receberam o premix de monensina [5 mg/kg (dose única) e 4 mg/kg (quatro doses diárias de 1 mg/kg)] não se observaram lesões macroscópicas ou microscópicas. Em nenhum dos dois eqüinos se observaram lesões macro ou microscópicas no miocárdio.