Gabriel Laizola Frainer Correa

Intoxicação experimental por Trema micrantha (Cannabaceae) em equinos

The aim of this study was to confirm the toxicity and characterize the clinical and pathological aspects of poisoning by Trema micrantha in horses. The green leaves of the plant were spontaneously consumed by three ponies at single doses of 20, 25, and 30g/kg. The three ponies developed clinical disease characterized by apathy, equilibrium deficit, deglutition difficulty, sternal or lateral recumbency, paddling, coma and death. Affected ponies had also enhanced seric activity of gamma-glutamyl transferase, seric ammonia apart of diminished glycemia. An additional pony, that received 15 and 25g/kg of T. micrantha with a 30 day interval between the two doses, showed no clinical disease. The three ponies were necropsied and fragments from organs were collected for histology and immunostaining (IS) procedures. The main pathological findings were in the liver and encephalon. There were enhanced lobular pattern of the liver and yellowish areas in the cut surface of the encephalon, especially visualized in the cerebellar white matter. Microscopically, there was hepatocellular swelling and coagulative hepatic necrosis predominantly centrilobular with hemorrhages. Generalized perivascular edema and Alzheimer type II astrocytes were observed in the encephalon. The Alzheimer type II astrocytes showed weak or absent anti-glial fibrillar acid protein IS associated with positive IS for S-100 protein. The minimal lethal dose of Trema micrantha leaves was established at 20g/kg. The sensibility of horses to this plant, its wide distribution and high palatability reinforces the importance of Trema micrantha in accidental poisoning of horses.

Utilização de biópsias da terceira pálpebra e mucosa retal em ovinos para diagnóstico de scrapie em uma propriedade da região sul do Brasil

Scrapie, a form of transmissible spongiform encephalopathy (TSEs) is a fatal neurodegenerative disorder that affects sheep and goats. The disease is characterized by an accumulation of the abnormal prionic protein (PrPSc) in the encephalic and lymphoreticular tissues. This paper describes the use of anti-prionic protein immunohistochemical (IHC) procedure as a method of pre-clinical diagnosis of scrapie.The test was carried out in biopsied lymphoreticular tissues from third eyelid and rectal mucosa. Anti-prion protein monoclonal antibodies F89/160.1.5 and F99/97.6.1 were used. Scrapie diagnosis in lymphoreticular tissues through IHC was achieved when the samples had a minimum of three lymphoid follicles in well delimited germinal centre. Positive immunostaining was identified in 19 out of 318 samples of the third eyelid. Material sampled at post-mortem examination in 18 of these scrapie-positive sheep, which were previously verified by biopsy, and in 21 of its relatives, was confirmed with IHC tests. Positive immunostaining from rectal mucosa tissue was not observed. Third eyelid and tonsil were the organs with the larger amount of positive immunostaining (18/18 and 8/18 respectively) at post-mortem examination. None positive result was obtained along the 21 animals related to the positive ones, and none of the positive cases showed IHC labeling in the brain. The use of lymphoid tissues for scrapie diagnosis by IHC through biopsies showed to be a viable and efficient method for pre-clinical diagnostic.

Intoxicação espontânea por Cestrum intermedium em bovinos no Sudoeste do Estado do Paraná

Sao descritos surtos de intoxicacao espontânea por Cestrum intermedium em bovinos leiteiros do Municipio de Salgado Filho, sudoeste do Estado do Parana, com morte de dezesseis bovinos de um total de 72 de quatro pequenas propriedades. O historico obtido nessas propriedades incluia curso clinico agudo, com morte em menos de 24 horas. Em todas foram observadas elevada lotacao por area com escassa pastagem disponivel e grande quantidade de plantas arbustivas identificadas como C. intermedium e com sinais de terem sido consumidas pelos animais. Dois bovinos foram necropsiados e os achados mais importantes foram congestao de mucosas conjuntivais e vulvovestibular; hemorragias e evidenciacao do padrao lobular no figado; hemorragia, congestao e edema pulmonares; congestao esplenica e encefalica, alem de hemorragias multifocais no coracao. Amostras de tecidos desses bovinos foram avaliadas, com alteracoes histologicas importantes no figado, caracterizadas por necrose acentuada de hepatocitos e hemorragia, indicativas de hepatopatia toxica aguda e, no encefalo, foram observadas alteracoes astrocitarias em substância branca de cerebro e cerebelo e na substância cinzenta do cerebelo, caracterizadas por tumefacao celular com citoplasma amplo e eosinofilico, nucleo picnotico, ora excentrico. Essas alteracoes astrocitarias foram evidenciadas pela tecnica de imuno-histoquimica (IHQ), com imunomarcacao fortemente positiva para os anticorpos anti-proteina S100 (anti-S100) e anti-proteina glial fibrilar acida (anti-GFAP). O trabalho visa enfatizar em lesoes encefalicas relacionadas a hepatotoxicidade aguda em bovinos.

Pathological findings in fetuses of goats and cattle poisoned by Sida carpinifolia (Malvaceae)

In Brazil, the consumption of Sida carpinifolia by livestock has been associated with neurological diseases linked to lysosomal storage disorders. This paper describes the pathological findings in two caprine fetuses from dams that were experimentally poisoned with S. carpinifolia. The goats were orally dosed with 10 and 13g/kg of a paste of green chopped S. carpinifolia for 30 days and were observed for an additional 15 days period after the last dosage with the plant; thereafter they were euthanized and necropsied. The dams showed only slight clinical signs. The study also includes the findings in one bovine fetus from a naturally S. carpinifolia poisoned cow which showed mild incoordination, generalized tremors, staggering, and frequent falls. The cow was euthanized and necropsied. While there were no significant histopathological changes in the goats, in the cow vacuolation of Purkinje neurons of the cerebellum, pancreatic acinar cells, and thyroid follicular cells were observed. The main microscopic changes observed in the caprine and bovine fetuses were vacuolation in the epithelium of renal tubules, thyroid follicular cells, and Purkinje neurons of the cerebellum. Transmission electron microscopy of sections from CNS of the cow and its fetus revealed vacuoles containing fine granular material surrounded by membrane. Lectin-histochemistry of CNS sections from goat fetuses marked lightly to sWGA lectins, WGA, and Con-A.

Novos aspectos sobre a intoxicação por Trema micrantha (Cannabaceae) em equídeos

Trema micrantha e uma planta arborea distribuida amplamente no Brasil. Descrevem-se nesse trabalho novos aspectos epidemiologicos e patologicos relacionados com a intoxicacao por essa planta em equideos. Dois equinos adultos da raca Crioula e dois asininos, de localidades distintas, foram intoxicados naturalmente por Trema micrantha, apos consumirem grande quantidade da planta que ficou disponivel a eles apos uma poda. Alem disso, um cavalo adulto, de outra propriedade, que estava passando por restricao alimentar, se intoxicou apos consumir as partes baixas de um grande numero de arvores jovens de T. micrantha. Clinicamente, em todos os equideos a doenca se caracterizou por alteracoes neurologicas, que apareceram tres a quatro dias apos o consumo da planta, com curso clinico de dois a quatro dias (abreviadas por eutanasia). Os principais achados de necropsia foram observados no figado, que estavam levemente aumentados e com padrao lobular evidente e no sistema nervoso central (SNC), com multiplas areas amareladas, focos de malacia e hemorragia, principalmente, no tronco cerebral e cerebelo. Histologicamente, havia necrose hepatica aguda, edema acentuado no SNC com degeneracao fibrinoide da parede de vasos associada a hemorragia e trombose e, frequentemente, com infiltrado de neutrofilos. Outras alteracoes observadas nos encefalos foram: grande quantidade de astrocitos de Alzheimer tipo II na substância cinzenta, acumulos de celulas Gitter e degeneracao Walleriana proxima a focos de lesoes vasculares.

Scrapie diagnosis in a goat and four Santa Inês sheep from the same herd in Brazil

Scrapie is a fatal and progressive transmissible spongiform encephalopathy (TSE) of natural occurrence in sheep and goats. The suspicion of scrapie may be based on clinical signs; however, the detection of pathological features of the prionic protein (PrP) in target tissues is necessary to diagnose the disease. The presence of an abnormal protein form (PrPSc) in lymphoreticular and nervous tissues is an important characteristic in diagnosis. This paper reports a case of scrapie in a flock of 55 Suffolk crossbred sheep, 19 Santa Ines sheep and 21 goats in the Mato Grosso state, midwestern Brazil. The animals were euthanized after the confirmation of a scrapie case with clinical signs in a Suffolk sheep in the same farm. Samples of brainstem at the level of the obex and lymphoid issues like palatine tonsils, mesenteric lymph nodes, third eyelid fixed in formalin 10% were processed for histological examination. Histological examination with hematoxylin and eosin did not show any microscopic changes in samples. Immunohistochemistry (IHC) examination to detect anti-prion PrPSc was performed in lymphoid tissues. Scrapie diagnosis was confirmed based on IHC positive results for PrPSc in lymphoid tissues of a crossbreed goat and four Santa Ines sheep, without any clinical scrapie signs. IHC showed positive staining in at least three lymphoid germinal centers in goat mesenteric lymph node, palatine tonsil, and third eyelid samples. The mesenteric lymph node, and tonsil samples of all sheep showed positive immunostaining, and only one sheep showed positive staining in lymphoid follicles in the third eyelid. Scrapie diagnosis using IHC in fixed samples of lymphoreticular tissue is technically feasible to detect the disease in both goats and sheep, as a form of pre-clinical diagnosis. The results indicate that the herd was infected by a sheep coming from another herd where scrapie had been diagnosed before.