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Mauro P. Soares - One of the best experts on this subject based on the ideXlab platform.
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pulmonary and hepatic lesions caused by the dehydropyrrolizidine alkaloid producing plants crotalaria juncea and crotalaria retusa in donkeys
Toxicon, 2013Co-Authors: Clarice R M Pessoa, Mauro P. Soares, Andre F A Pessoa, Lisanka A Maia, Rosane M T Medeiros, Steven M Colegate, S S Barros, Alexandre Secorun Borges, Franklin RietcorreaAbstract:The effects and susceptibility of donkeys to Crotalaria juncea and Crotalaria retusa poisoning were determined at high and low doses. Seeds of C. juncea containing 0.074% of dehydropyrrolizidine alkaloids (DHPAs) (isohemijunceines 0.05%, trichodesmine 0.016%, and junceine 0.008%) were administered to three donkeys at 0.3, 0.6 and 1 g/kg body weight (g/kg) daily for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was a mild liver Megalocytosis in the donkeys ingesting 0.6 and 1 g/kg/day. Two other donkeys that received daily doses of 3 and 5 g seed/kg showed initial respiratory signs 70 and 40 days after the start of the administration, respectively. The donkeys were euthanized following severe respiratory signs and the main lung lesions were proliferation of Clara cells and interstitial fibrosis. Three donkeys ingested seeds of C. retusa containing 5.99% of monocrotaline at daily doses of 0.025, 0.05 and 0.1 g/kg for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was moderate liver Megalocytosis in each of the three donkeys. One donkey that received a single dose of 5 g/kg of C. retusa seeds and another that received 1 g/kg daily for 7 days both showed severe clinical signs and died with diffuse centrilobular liver necrosis. No lung lesions were observed. Another donkey that received a single dose of 2.5 g/kg of C. retusa seeds showed no clinical signs. The hepatic and pneumotoxic effects observed are consistent with an etiology involving DHPAs. Furthermore, the occurrence of lung or liver lesions correlates with the type of DHPAs contained in the seeds. Similarly as has been reported for horses, the data herein suggest that in donkeys some DHPAs are metabolized in the liver causing liver disease, whereas others are metabolized in the lung by Clara cells causing lung disease.
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Aspectos epidemiológicos e padrões de lesões hepáticas em 35 surtos de intoxicação por Senecio spp. em bovinos no sul do Rio Grande do Sul
Pesquisa Veterinária Brasileira, 2010Co-Authors: Fabiane B. Grecco, Ana Lucia Schild, Mauro P. Soares, Clairton Marcolongo-pereira, Pablo Estima-silva, Eliza Simone Viégas SallisAbstract:The study aimed to characterize morphological patterns of 59 liver samples of Senecio spp. poisoned cattle from 35 outbreaks, observed in southern Rio Grande do Sul, Brazil, from 2000 to 2009. The lesions were associated with epidemiological changes during these years. The climate changes concerning accumulated rain and mean temperature during the different seasons were analyzed. The macroscopic and histological lesions were classified into 6 different patterns. The macroscopic classification was made according to capsular pattern, hepatic cut surface discoloration, and the presence of nodules. The histological classification was based on the distribution of fibrosis, the amount of megalocytes in 10 high magnification fields, and on bile duct proliferation. Pattern 1 was characterized by a whitish liver, diffuse fibrosis, severe bile duct proliferation, and discrete Megalocytosis; pattern 2 was characterized by nodules consisting of groups of hepatocytes surrounded by fibrosis, severe bile duct proliferation, and discrete to mild Megalocytosis; pattern 3 was characterized by a macro-nodular aspect to the cut surface with hepatic lobules surrounded by a thin septa of fibrous tissue, severe bile duct proliferation, and mild Megalocytosis; pattern 4 was characterized by a non-nodular surface with marble aspect, mild to severe bile duct proliferation, and Megalocytosis; pattern 5 was characterized by a non-nodular surface and bridging or diffuse fibrosis, mild Megalocytosis, and severe bile duct proliferation; and pattern 6 was characterized by a non-nodular surface, severe Megalocytosis, discrete bile duct proliferation, and incipient fibrosis of the portal system, central vein or among hepatocyte cords. The results of macroscopic and histological liver analysis showed that patterns 1, 2 and 4 were the most frequently observed. The results of this study demonstrated that the macroscopic lesion observed in Senecio poisoned cattle is variable. Histologically this variation is related to the amount and distribution of fibrosis, Megalocytosis and bile duct proliferation observed in each liver. Age of the cattle, evolution period of poisoning and clinical signs did not interfere on the pattern of lesions observed. On the other hand, climatic conditions probably had influence on increased disease prevalence due to major availability of Senecio spp. plants.
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Aspectos epidemiológicos e padrões de lesões hepáticas em 35 surtos de intoxicação por Senecio spp. em bovinos no sul do Rio Grande do Sul Epidemiological aspects and hepatic lesions pattern in 35 outbreaks of Senecio spp. poisoning in cattle in sout
Colégio Brasileiro de Patologia Animal (CBPA), 2010Co-Authors: Fabiane B. Grecco, Ana Lucia Schild, Mauro P. Soares, Clairton Marcolongo-pereira, Pablo Estima-silva, Eliza Simone Viégas SallisAbstract:O presente estudo teve como objetivo caracterizar os diferentes padrões morfológicos hepáticos em 59 fígados de bovinos intoxicados por Senecio spp. provenientes de 35 surtos observados na área de influência do Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD) de 2000-2009, dos quais havia registro fotográfico das lesões macroscópicas, fazendo uma relação com as variações epidemiológicas observadas no período. Foram analisadas as variações climáticas referentes à precipitação pluviométrica e temperatura média nas diferentes estações do ano ocorridas neste intervalo de tempo. As alterações hepáticas macro e microscópicas foram agrupadas em padrões morfológicos semelhantes. Foi considerada como critérios de classificação macroscópica a coloração das superfícies capsular e de corte e a presença ou não de nódulos; e como critérios para a classificação histológica a quantidade e distribuição da fibrose, o número de megalócitos por campo de maior aumento, o grau estimado de proliferação de ductos biliares e a presença de hepatócitos vacuolizados. O Padrão 1 caracterizou-se por fígado esbranquiçado, fibrose difusa, acentuada proliferação de células de ductos biliares e megalocitose discreta; o Padrão 2 por presença de nódulos correspondentes a grupos de hepatócitos ou lóbulos hepáticos circundados por tecido conjuntivo fibroso, acentuada proliferação de células de ductos biliares e megalocitose de discreta a moderada; o Padrão 3 por superfície de corte com aspecto macronodular correspondente a lóbulos hepáticos circundados por delgado cordão de tecido conjuntivo, acentuada proliferação de ductos biliares e megalocitose moderada; o Padrão 4 por superfície sem nodulações e com aspecto marmorizado e histologicamente por fibrose em ponte, megalocitose e proliferação de células de ductos de moderadas a acentuadas; o Padrão 5 por superfície sem nodulações e microscopicamente por fibrose em ponte a difusa, megalocitose moderada e acentuada proliferação de células de ductos; e, o Padrão 6 por superfície sem nodulações e microscopicamente por megalocitose acentuada, proliferação de ductos discreta e fibrose em estágio inicial localizada nos espaços porta e veia centrolobular ou como colágeno imaturo entre os cordões de hepatócitos. Os resultados da análise macroscópica e histológica dos fígados dos bovinos demonstraram que os Padrões 1, 2 e 4 foram os mais frequentemente encontrados. Os resultados deste trabalho demonstram que a lesão hepática macroscópica que ocorre em bovinos intoxicados por Senecio spp. é variável e que histologicamente esta variação está relacionada à distribuição e a quantidade da fibrose, à quantidade de megalócitos e à proliferação biliar observadas em cada fígado. A idade dos animais, o tempo de evolução da intoxicação e os sinais clínicos não interferem nos padrões de lesões hepáticas encontradas. Por outro lado, as condições climáticas provavelmente tiveram influência no aumento da freqüência da doença devido ao aumento da disponibilidade da planta.The study aimed to characterize morphological patterns of 59 liver samples of Senecio spp. poisoned cattle from 35 outbreaks, observed in southern Rio Grande do Sul, Brazil, from 2000 to 2009. The lesions were associated with epidemiological changes during these years. The climate changes concerning accumulated rain and mean temperature during the different seasons were analyzed. The macroscopic and histological lesions were classified into 6 different patterns. The macroscopic classification was made according to capsular pattern, hepatic cut surface discoloration, and the presence of nodules. The histological classification was based on the distribution of fibrosis, the amount of megalocytes in 10 high magnification fields, and on bile duct proliferation. Pattern 1 was characterized by a whitish liver, diffuse fibrosis, severe bile duct proliferation, and discrete Megalocytosis; pattern 2 was characterized by nodules consisting of groups of hepatocytes surrounded by fibrosis, severe bile duct proliferation, and discrete to mild Megalocytosis; pattern 3 was characterized by a macro-nodular aspect to the cut surface with hepatic lobules surrounded by a thin septa of fibrous tissue, severe bile duct proliferation, and mild Megalocytosis; pattern 4 was characterized by a non-nodular surface with marble aspect, mild to severe bile duct proliferation, and Megalocytosis; pattern 5 was characterized by a non-nodular surface and bridging or diffuse fibrosis, mild Megalocytosis, and severe bile duct proliferation; and pattern 6 was characterized by a non-nodular surface, severe Megalocytosis, discrete bile duct proliferation, and incipient fibrosis of the portal system, central vein or among hepatocyte cords. The results of macroscopic and histological liver analysis showed that patterns 1, 2 and 4 were the most frequently observed. The results of this study demonstrated that the macroscopic lesion observed in Senecio poisoned cattle is variable. Histologically this variation is related to the amount and distribution of fibrosis, Megalocytosis and bile duct proliferation observed in each liver. Age of the cattle, evolution period of poisoning and clinical signs did not interfere on the pattern of lesions observed. On the other hand, climatic conditions probably had influence on increased disease prevalence due to major availability of Senecio spp. plants
Pravin B. Sehgal - One of the best experts on this subject based on the ideXlab platform.
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Running title: Depleted Golgi NSF and hypo-S-nitrosylation after MCTP To whom correspondence should be addressed:
2013Co-Authors: Somshuvra Mukhopadhyay, Pravin B. Sehgal, Jason Lee, B. SehgalAbstract:Investigations of regulated S-nitrosylation and denitrosylation of vasorelevant proteins is a newly emergent area in vascular biology. We previously showed that monocrotaline pyrrole (MCTP)-induced Megalocytosis of pulmonary arterial endothelial cells (PAECs), which underlies development of pulmonary arterial hypertension (PAH), was associated with a Golgi blockade characterized by trapping of diverse vesicle tethers, SNAREs and SNAPs in the Golgi; reduced trafficking of caveolin-1 (cav-1) and eNOS from the Golgi to the plasma membrane and decreased caveolar nitric oxide (NO). We have investigated whether N-ethylmaleimide sensitive factor (NSF), the ATPase involved in all SNARE-disassembly, might be the upstream target of MCTP and whether MCTP might regulate NSF by S-nitrosylation. Immunofluorescence microscopy and Golgi purification techniques revealed the discordant decrease of NSF by approximately 50 % in Golgi membranes after MCTP despite increases in α-SNAP, cav-1, eNOS and syntaxin-6. The NO scavenger (4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) failed to affect initiation or progression of MCTP-Megalocytosis despite reduction of 4,5-diaminofluorescein diacetate (DAF-2DA) fluorescence and inhibition of S
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Discordant regulatory changes in monocrotaline-induced Megalocytosis of lung arterial endothelial and alveolar epithelial cells.
American journal of physiology. Lung cellular and molecular physiology, 2006Co-Authors: Somshuvra Mukhopadhyay, Pravin B. SehgalAbstract:Monocrotaline (MCT) causes pulmonary hypertension in the rat by a mechanism characterized by Megalocytosis (enlarged cells with enlarged endoplasmic reticulum and Golgi and a cell cycle arrest) of ...
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Monocrotaline pyrrole-induced Megalocytosis of lung and breast epithelial cells: Disruption of plasma membrane and Golgi dynamics and an enhanced unfolded protein response.
Toxicology and applied pharmacology, 2005Co-Authors: Somshuvra Mukhopadhyay, Mehul Shah, Kirit Patel, Pravin B. SehgalAbstract:The pyrrolizidine alkaloid monocrotaline (MCT) initiates pulmonary hypertension by inducing a "Megalocytosis" phenotype in target pulmonary arterial endothelial, smooth muscle and Type II alveolar epithelial cells. In cultured endothelial cells, a single exposure to the pyrrolic derivative of monocrotaline (MCTP) results in large cells with enlarged endoplasmic reticulum (ER) and Golgi and increased vacuoles. However, these cells fail to enter mitosis. Largely based upon data from endothelial cells, we proposed earlier that a disruption of the trafficking and mitosis-sensor functions of the Golgi (the "Golgi blockade" hypothesis) may represent the subcellular mechanism leading to MCTP-induced Megalocytosis. In the present study, we investigated the applicability of the Golgi blockade hypothesis to epithelial cells. MCTP induced marked Megalocytosis in cultures of lung A549 and breast MCF-7 cells. This was associated with a change in the distribution of the cis-Golgi scaffolding protein GM130 from a discrete juxtanuclear localization to a circumnuclear distribution consistent with an anterograde block of GM130 trafficking to/through the Golgi. There was also a loss of plasma membrane caveolin-1 and E-cadherin, cortical actin together with a circumnuclear accumulation of clathrin heavy chain (CHC) and alpha-tubulin. Flotation analyses revealed losses/alterations in the association of caveolin-1, E-cadherin and CHC with raft microdomains. Moreover, Megalocytosis was accompanied by an enhanced unfolded protein response (UPR) as evidenced by nuclear translocation of Ire1alpha and glucose regulated protein 58 (GRP58/ER-60/ERp57) and a circumnuclear accumulation of PERK kinase and protein disulfide isomerase (PDI). These data further support the hypothesis that an MCTP-induced Golgi blockade and enhanced UPR may represent the subcellular mechanism leading to enlargement of ER and Golgi and subsequent Megalocytosis.
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Monocrotaline pyrrole-induced endothelial cell Megalocytosis involves a
2005Co-Authors: Golgi Blockade Mechanism, Mehul Shah, Kirit Patel, Pravin B. Sehgal, Pravin Sehgal B. MonocrotalineAbstract:00327.2004.—Pyrrolizidine alkaloids initiate disease in the lung (pul-monary hypertension), liver (veno-occlusive disease and cirrhosis), and kidneys (afferent arteriolar block and mesangiolysis) by inducing a megalocytotic phenotype in target endothelial and parenchymal cells. A “hit-and-run ” type of exposure to the bioactive pyrrolizidine results, within 2–3 days, in enlarged cells with large nuclei and enlarged Golgi and endoplasmic reticulum, while the cells remain in G2/M block. In the present study, we recapitulated monocrotaline pyrrole (MCTP)-induced Megalocytosis in cultures of bovine pulmo-nary arterial endothelial cells (PAEC), human Hep3B hepatocytes, human type II-like alveolar epithelial cells (A549), and human pul-monary arterial smooth muscle cells (PASMC) and investigated the subcellular mechanism involved. There was an inverse relationship between reduction in caveolin (Cav)-1 levels and stimulation of promitogenic STAT3 and ERK1/2 cell signaling. In megalocytoti
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Monocrotaline pyrrole-induced endothelial cell Megalocytosis involves a Golgi blockade mechanism.
American journal of physiology. Cell physiology, 2004Co-Authors: Mehul Shah, Kirit Patel, Pravin B. SehgalAbstract:Pyrrolizidine alkaloids initiate disease in the lung (pulmonary hypertension), liver (veno-occlusive disease and cirrhosis), and kidneys (afferent arteriolar block and mesangiolysis) by inducing a ...
Claudio S.l. Barros - One of the best experts on this subject based on the ideXlab platform.
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Seneciosis in cattle associated with photosensitization
Colégio Brasileiro de Patologia Animal (CBPA), 2014Co-Authors: Paula R. Giaretta, Welden Panziera, Glauco J.a. Galiza, Juliana S. Brum, Ronaldo M. Bianchi, Márcia E. Hammerschmitt, Talissa Bazzi, Claudio S.l. BarrosAbstract:Senecio spp. poisoning is the main cause of cattle mortality in the central region of Rio Grande do Sul. This paper reports an outbreak of seneciosis in cattle with high prevalence of photosensitization, where 83 out of 162 cows (51.3%) presented this clinical sign. The outbreak occurred in September 2013, affecting adult cows that were held in a 205 hectare-pasture from April to October 2013 with abundant Senecio brasiliensis infestation. Main clinical signs were weight loss, excessive lacrimation or mucopurulent ocular discharge, nasal serous discharge, ventral diphteric glossitis, crusts in the nose, teats, dorsum of ears, and vulva. Liver biopsy was performed in all the cows under risk; the histopathological findings in the liver biopsies consisted of fibrosis, Megalocytosis, and biliary ductal proliferation and were present in 73.4% of the biopsied animals. Six cows had increased serum activity of gamma glutamyl transferase. Three affected cows were necropsied. The main necropsy findings were a hard liver, distended gall bladder, edema of the mesentery and abomasum. Liver histological changes in the necropsied cows were similar to those of the biopsied livers. Spongiosis was detected in the brain of necropsied cows and is characteristic of hepatic encephalopathy
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Aspectos clínico-patológicos da intoxicação crônica por Senecio spp. em ovinos
Pesquisa Veterinária Brasileira, 2014Co-Authors: Paula R. Giaretta, Welden Panziera, Ronaldo M. Bianchi, Talissa Bazzi, Marcia Elisa Hammerschmitt, Glauco José Nogueira De Galiza, Ingrid S. Wiethan, Claudio S.l. BarrosAbstract:This paper describes an outbreak of chronic Senecio spp. poisoning in grazing sheep in Rio Grande do Sul, Brazil, causing the death of 10 out of 860 adult sheep. Eight sick ewes were euthanized and necropsied. Cattle from this farm were also affected. Clinical signs included progressive weight loss, apathy and photosensitization. Four out of seven tested sheep had increased gamma-glutamyl transferase serum activity and two of them presented serum elevation of alkaline phosphatase. At necropsy, three out of eight ewes presented slightly irregular toughened livers with multifocal nodules, two out of eight ewes had a whitish liver with thickened fibrotic Glisson's capsule partially adhered to the diaphragm, and three out of eight ewes had smooth and grossly normal livers. Necropsy findings attributed to liver failure included hydropericardium (7/8), ascites (5/8), icterus (2/8), hydrothorax (1/8), and edema of mesentery (1/8). The main hepatic histological findings that allowed the establishment of the diagnosis were Megalocytosis, proliferation of bile ducts and fibrosis. Spongy degeneration was observed in the brains of all eight necropsied sheep and was more severe at the cerebellar peduncles, mesencephalon, thalamus, and pons. These are suggested as the portions of election to investigate microscopic lesions of hepatic encephalopathy in sheep with chronic seneciosis. The diagnosis of Senecio spp. poisoning was based on epidemiology, clinical signs, laboratory data, necropsy and histological findings.
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Surto de aflatoxicose em bezerros no Rio Grande do Sul
Pesquisa Veterinária Brasileira, 2010Co-Authors: Felipe Pierezan, José C. Oliveira Filho, Priscila M. S. Carmo, Ricardo B. Lucena, Daniel R. Rissi, Monique Togni, Claudio S.l. BarrosAbstract:An outbreak of chronic aflatoxicosis is reported in dairy calves. Forty 4-month-old male Holstein calves of approximately 100kg were kept in individual cages of 1.5 x 1.5m and were fed a ration constituted by alfalfa hay, broken corn and milk substitute. Six calves (15%) died after presenting a disease characterized by general unthriftiness, diarrhea, rough hair coats, abdominal pain, prolapsed rectum, grinding of teeth, and lying down and rolling. The clinical course, as observed by the owners, was 2-3 days; however many calves in this lot that did not die, remained underdeveloped. Three calves were necropsied. Necropsy findings included firm, light tan livers and marked hydrothorax, ascites and edema of the mesentery, mesocolon and of the mucosal folds of the abomasum. Main histopathological changes were restricted to the liver and consisted of fibrosis, moderate Megalocytosis, biliary duct hyperplasia and veno-occlusive disease. The search for Senecio spp. contamination in the alfalfa hay resulted negative. The analysis by thin layer chromatography of the corn fed to calves revealed 5,136 ppb of aflatoxin B1. A diagnosis of aflatoxicosis was made based on the characteristic clinical signs and pathology, on the absence of Senecio spp. in the food and on the presence of high levels of aflatoxin in the corn fed to the calves.
Eliza Simone Viégas Sallis - One of the best experts on this subject based on the ideXlab platform.
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Aspectos epidemiológicos e padrões de lesões hepáticas em 35 surtos de intoxicação por Senecio spp. em bovinos no sul do Rio Grande do Sul
Pesquisa Veterinária Brasileira, 2010Co-Authors: Fabiane B. Grecco, Ana Lucia Schild, Mauro P. Soares, Clairton Marcolongo-pereira, Pablo Estima-silva, Eliza Simone Viégas SallisAbstract:The study aimed to characterize morphological patterns of 59 liver samples of Senecio spp. poisoned cattle from 35 outbreaks, observed in southern Rio Grande do Sul, Brazil, from 2000 to 2009. The lesions were associated with epidemiological changes during these years. The climate changes concerning accumulated rain and mean temperature during the different seasons were analyzed. The macroscopic and histological lesions were classified into 6 different patterns. The macroscopic classification was made according to capsular pattern, hepatic cut surface discoloration, and the presence of nodules. The histological classification was based on the distribution of fibrosis, the amount of megalocytes in 10 high magnification fields, and on bile duct proliferation. Pattern 1 was characterized by a whitish liver, diffuse fibrosis, severe bile duct proliferation, and discrete Megalocytosis; pattern 2 was characterized by nodules consisting of groups of hepatocytes surrounded by fibrosis, severe bile duct proliferation, and discrete to mild Megalocytosis; pattern 3 was characterized by a macro-nodular aspect to the cut surface with hepatic lobules surrounded by a thin septa of fibrous tissue, severe bile duct proliferation, and mild Megalocytosis; pattern 4 was characterized by a non-nodular surface with marble aspect, mild to severe bile duct proliferation, and Megalocytosis; pattern 5 was characterized by a non-nodular surface and bridging or diffuse fibrosis, mild Megalocytosis, and severe bile duct proliferation; and pattern 6 was characterized by a non-nodular surface, severe Megalocytosis, discrete bile duct proliferation, and incipient fibrosis of the portal system, central vein or among hepatocyte cords. The results of macroscopic and histological liver analysis showed that patterns 1, 2 and 4 were the most frequently observed. The results of this study demonstrated that the macroscopic lesion observed in Senecio poisoned cattle is variable. Histologically this variation is related to the amount and distribution of fibrosis, Megalocytosis and bile duct proliferation observed in each liver. Age of the cattle, evolution period of poisoning and clinical signs did not interfere on the pattern of lesions observed. On the other hand, climatic conditions probably had influence on increased disease prevalence due to major availability of Senecio spp. plants.
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Aspectos epidemiológicos e padrões de lesões hepáticas em 35 surtos de intoxicação por Senecio spp. em bovinos no sul do Rio Grande do Sul Epidemiological aspects and hepatic lesions pattern in 35 outbreaks of Senecio spp. poisoning in cattle in sout
Colégio Brasileiro de Patologia Animal (CBPA), 2010Co-Authors: Fabiane B. Grecco, Ana Lucia Schild, Mauro P. Soares, Clairton Marcolongo-pereira, Pablo Estima-silva, Eliza Simone Viégas SallisAbstract:O presente estudo teve como objetivo caracterizar os diferentes padrões morfológicos hepáticos em 59 fígados de bovinos intoxicados por Senecio spp. provenientes de 35 surtos observados na área de influência do Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD) de 2000-2009, dos quais havia registro fotográfico das lesões macroscópicas, fazendo uma relação com as variações epidemiológicas observadas no período. Foram analisadas as variações climáticas referentes à precipitação pluviométrica e temperatura média nas diferentes estações do ano ocorridas neste intervalo de tempo. As alterações hepáticas macro e microscópicas foram agrupadas em padrões morfológicos semelhantes. Foi considerada como critérios de classificação macroscópica a coloração das superfícies capsular e de corte e a presença ou não de nódulos; e como critérios para a classificação histológica a quantidade e distribuição da fibrose, o número de megalócitos por campo de maior aumento, o grau estimado de proliferação de ductos biliares e a presença de hepatócitos vacuolizados. O Padrão 1 caracterizou-se por fígado esbranquiçado, fibrose difusa, acentuada proliferação de células de ductos biliares e megalocitose discreta; o Padrão 2 por presença de nódulos correspondentes a grupos de hepatócitos ou lóbulos hepáticos circundados por tecido conjuntivo fibroso, acentuada proliferação de células de ductos biliares e megalocitose de discreta a moderada; o Padrão 3 por superfície de corte com aspecto macronodular correspondente a lóbulos hepáticos circundados por delgado cordão de tecido conjuntivo, acentuada proliferação de ductos biliares e megalocitose moderada; o Padrão 4 por superfície sem nodulações e com aspecto marmorizado e histologicamente por fibrose em ponte, megalocitose e proliferação de células de ductos de moderadas a acentuadas; o Padrão 5 por superfície sem nodulações e microscopicamente por fibrose em ponte a difusa, megalocitose moderada e acentuada proliferação de células de ductos; e, o Padrão 6 por superfície sem nodulações e microscopicamente por megalocitose acentuada, proliferação de ductos discreta e fibrose em estágio inicial localizada nos espaços porta e veia centrolobular ou como colágeno imaturo entre os cordões de hepatócitos. Os resultados da análise macroscópica e histológica dos fígados dos bovinos demonstraram que os Padrões 1, 2 e 4 foram os mais frequentemente encontrados. Os resultados deste trabalho demonstram que a lesão hepática macroscópica que ocorre em bovinos intoxicados por Senecio spp. é variável e que histologicamente esta variação está relacionada à distribuição e a quantidade da fibrose, à quantidade de megalócitos e à proliferação biliar observadas em cada fígado. A idade dos animais, o tempo de evolução da intoxicação e os sinais clínicos não interferem nos padrões de lesões hepáticas encontradas. Por outro lado, as condições climáticas provavelmente tiveram influência no aumento da freqüência da doença devido ao aumento da disponibilidade da planta.The study aimed to characterize morphological patterns of 59 liver samples of Senecio spp. poisoned cattle from 35 outbreaks, observed in southern Rio Grande do Sul, Brazil, from 2000 to 2009. The lesions were associated with epidemiological changes during these years. The climate changes concerning accumulated rain and mean temperature during the different seasons were analyzed. The macroscopic and histological lesions were classified into 6 different patterns. The macroscopic classification was made according to capsular pattern, hepatic cut surface discoloration, and the presence of nodules. The histological classification was based on the distribution of fibrosis, the amount of megalocytes in 10 high magnification fields, and on bile duct proliferation. Pattern 1 was characterized by a whitish liver, diffuse fibrosis, severe bile duct proliferation, and discrete Megalocytosis; pattern 2 was characterized by nodules consisting of groups of hepatocytes surrounded by fibrosis, severe bile duct proliferation, and discrete to mild Megalocytosis; pattern 3 was characterized by a macro-nodular aspect to the cut surface with hepatic lobules surrounded by a thin septa of fibrous tissue, severe bile duct proliferation, and mild Megalocytosis; pattern 4 was characterized by a non-nodular surface with marble aspect, mild to severe bile duct proliferation, and Megalocytosis; pattern 5 was characterized by a non-nodular surface and bridging or diffuse fibrosis, mild Megalocytosis, and severe bile duct proliferation; and pattern 6 was characterized by a non-nodular surface, severe Megalocytosis, discrete bile duct proliferation, and incipient fibrosis of the portal system, central vein or among hepatocyte cords. The results of macroscopic and histological liver analysis showed that patterns 1, 2 and 4 were the most frequently observed. The results of this study demonstrated that the macroscopic lesion observed in Senecio poisoned cattle is variable. Histologically this variation is related to the amount and distribution of fibrosis, Megalocytosis and bile duct proliferation observed in each liver. Age of the cattle, evolution period of poisoning and clinical signs did not interfere on the pattern of lesions observed. On the other hand, climatic conditions probably had influence on increased disease prevalence due to major availability of Senecio spp. plants
Esam Agamy - One of the best experts on this subject based on the ideXlab platform.
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Histopathological Changes in the Livers of Rabbit Fish (Siganus canaliculatus) Following Exposure to Crude Oil and Dispersed Oil
2016Co-Authors: Esam AgamyAbstract:The present study aimed to assess the impact of acute exposure to crude oil, dispersed oil, and dispersant alone on the liver of the rabbit fish (Siganus canaliculatus). Histopathological effects in the liver were observed at different time points (3 to 21 days) and different concentrations (3–100 % water accommodated fraction [WAF]) to simulate a range of possible oil pollution events. The main alterations observed in this study include lipid accumulation, necrosis, bile stagnation, Megalocytosis, cholangitis, and spongiosis hepatis. The liver of fish exposed to WAF, dispersed oil, or dispersant showed significant histopathologic alterations compared with the control fish (Mann-Whitney U test; p <.01). Reaction pattern indices (circulatory, degenerative, proliferative, and inflammatory changes) of treated fish differed significantly from the control groups. There was a significant correlation between exposure time and the occurrence of most lesions (Spearman correlation; p>.05). The present study indicates that oil pollution can cause important alterations to livers of adult rabbit fish and that the dispersed oil is slightly more toxic than crude oil or dispersant
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Histopathological Changes in the Livers of Rabbit Fish (Siganus canaliculatus) Following Exposure to Crude Oil and Dispersed Oil
Toxicologic pathology, 2012Co-Authors: Esam AgamyAbstract:The present study aimed to assess the impact of acute exposure to crude oil, dispersed oil, and dispersant alone on the liver of the rabbit fish (Siganus canaliculatus). Histopathological effects in the liver were observed at different time points (3 to 21 days) and different concentrations (3–100% water accommodated fraction [WAF]) to simulate a range of possible oil pollution events. The main alterations observed in this study include lipid accumulation, necrosis, bile stagnation, Megalocytosis, cholangitis, and spongiosis hepatis. The liver of fish exposed to WAF, dispersed oil, or dispersant showed significant histopathologic alterations compared with the control fish (Mann-Whitney U test; p .05). The present study indicates that oil pollution can cause important alterations to livers of adult rabbit fish and that the dispersed oil is slightly more toxic than crude oil or dispersant.
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Histopathological liver alterations in juvenile rabbit fish (Siganus canaliculatus) exposed to light Arabian crude oil, dispersed oil and dispersant.
Ecotoxicology and environmental safety, 2011Co-Authors: Esam AgamyAbstract:Abstract With the heavy transport of crude oil there is an increasing risk of a major oil spill in the Gulf waters; however, there have been few studies on the impact of oil spills and subsequent remedial action on Gulf fish. The aim of the experiment was to investigate the effects of acute exposure to water soluble fraction (WAF) of light Arabian crude oil, dispersed oil and dispersant on the liver of the juvenile rabbit fish (Siganus canaliculatus), observing several histopathological biomarkers of the liver at different time points and different doses. The concentrations used (3–100 percent WAF) simulated a range of possible oil pollution events. The main alterations observed in this study include hepatocyte swelling and cytoplasmic vacuolisation, Megalocytosis, coagulative dispersed necrosis, lymphocytic infiltration, melanomacrophage aggregates, spongiosis hepatis, pericholangiitis, and bile stagnosis. Treated livers showed significantly higher total index values than the control group (p 0.05). The present study indicates that dispersed oil is not more toxic, to livers of juvenile rabbit fish, than crude oil or dispersant.