Navegando por Autor "PEIXOTO, Paulo Fernando de Vargas"

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Anemia hemolítica causada por Indigofera suffruticosa (Leg. Papilionoideae) em bovinos
(2001-03) BARBOSA NETO, José Diomedes; OLIVEIRA, Carlos Magno Chaves; PEIXOTO, Paulo Fernando de Vargas; BARBOSA, Imke Barbara Pfeifer; ÁVILA, Sandra Cristina de; TOKARNIA, Carlos Maria Antônio Hubinger
The aereal parts of Indigofera suffruticosa Mill. (family Leg. Papilionoideae) were force-fed fresh to 6 bovines in daily doses of 10 to 40 g/kg. Cattle breeders of various parts of the Northeast of Brazil accuse this plant as the cause of a non-fatal disease characterized by hemoglobinuria. The disease occurs only in years when the plant proliferates well invading the native pastures. All experimental animals had hemoglobinuria, which was transitory, inspite continuation of the administration of the plant. Two animals had no further manifestations, a third animal showed only slight other manifestations, and the other three had additional symptoms of moderate intensity. These were apathy, whitish visible mucous membranes, rough hair coat, anorexia, descrease in frequency and intensity of the ruminal movements, tachycardia, positive venous pulse and dispnoea. Before the occurrence of the hemolytic crisis the urine had a bluish-green colour. None of the experimental animals died, but one was euthanized whilst showing hemoglobinuria. Post-mortem findings were anemia, the bladder containing wine-red urine, swollen dark-brown kidneys, liver on the outside and on the cut-surface bluish and with perceptible lobular design. The main histological changes were found in liver and kidney. In the liver there was coagulative necrosis and cloudy swelling and/or cytoplasmatic microvacuolization of the hepatocytes; in the kidney there was severe nephrosis, associated with large amounts of filtrate and/or hemoglobine in the Bowman spaces, in the tubules and also in the cytoplasm of the epithelial cells.
Acesso aberto (Open Access)
Aspectos toxicológico, clínico-patológico e ultraestrutural das intoxicações iatrogênica e experimental por vitamina D em coelhos
(2010-03) PEIXOTO, Paulo Fernando de Vargas; KLEM, Marcius Alessandro Pessanha; BRITO, Marilene de Farias; CERQUEIRA, Valíria Duarte; FRANÇA, Ticiana do Nascimento
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).
Acesso aberto (Open Access)
Avaliação lectino-histoquímica de fígado e linfonodo mesentérico de búfalos mantidos em pastagens de Brachiaria spp.
(Universidade Federal do Pará, 2016-09) MIRANDA, Ileana Costa; RIVERO, Gabriela Riet Correa; OLIVEIRA JÚNIOR, Carlos Alberto de; RIVERO, Beatriz Riet Correa; PEIXOTO, Paulo Fernando de Vargas; COSTA, Samay Zillmann Rocha; D'AVILA, Mariana Sequeira; CID, Gabriela de Carvalho; FRANÇA, Ticiana do Nascimento
Animals grazing Brachiaria spp. commonly present foamy macrophages isolated or grouped in the liver, and crystals within biliary ducts. The pathogenesis of formation and the nature of the material stored in these cells however are not completely known. Through lectin histochemistry evaluation, steroidal saponins (secondary glycosylated metabolites) have been identified in the crystals and within the cytoplasm of the foam cells, which are probably liable for damaging the liver, leading to accumulation of phylloerythrin. This study aims to standardize and characterize the use of lectin histochemistry to detect glycosylated metabolites in tissues of buffaloes kept on different Brachiaria spp. pastures in Brazil. Fragments of liver and mesenteric lymph node from 40 buffaloes were analyzed: 10 buffaloes that were kept in predominant pasture of B. decumbens for 12 months; 10 buffaloes that were kept in pasture with a predominance of B. brizantha for 18 months; 10 buffaloes that were kept on pasture of B. brizantha for about four years; and as a negative control, 10 buffaloes that were maintained on native pasture without Brachiaria spp. since birth. Fourteen lectins were tested (Con-A, SBA, WGA, DBA, UEA, RCA, PNA, GSL-I, PSA, LCA, PHA-E, PHA-L, SJA and SWGA), in a total of 1120 evaluated samples. Previous studies demonstrated that PNA showed great binding reactivity for foamy macrophages in cattle and sheep. In the present study, SWGA showed high specificity and marked binding reactivity for foamy macrophages; WGA, GSL, PHA-E and PHA-L showed moderate to marked reactivity, but low specificity for foamy macrophages. The other lectins had not relevant reactivity or specificity. Moreover there was no relevant reactivity difference between the collected samplesd from buffaloes that grazed B. decumbens for 12 months and Brachiaria brizantha for 18 months. However the decreased presence of foamy macrophages and its lectin histochemical binding in animals that fed on B. brizantha for a longer time, indicates that the buffaloes can pass through an adaptation process according to the plant intake time. Lectin histochemistry analysis can be used to characterize the material stored in foamy macrophages present in liver and mesenteric lymph node of buffaloes that graze on Brachiaria spp. pastures and helps to clarify the pathogenesis of these cells.
Acesso aberto (Open Access)
Carcinoma de células escamosas perineal em cabras no Pará
(2009-05) BARBOSA NETO, José Diomedes; DUARTE, Marcos Dutra; OLIVEIRA, Carlos Magno Chaves; REIS, Alessandra dos Santos Belo; PEIXOTO, Tiago da Cunha; PEIXOTO, Paulo Fernando de Vargas; BRITO, Marilene de Farias
Squamous cell carcinoma in goats of two farms in the State of Pará is described. Prevalence, correlation with the pigmentation of the perineal area and macro and microscopic characteristics of the lesions were studied. The tumors on the perineum were of varied development degrees, diameters and forms. On one farm, in the county of Viseu, from a total of 347 goats, 20 presented the neoplasia (5.8%). On the second farm, in the county of Garrafão do Norte, three cases of squamous cell carcinoma in a herd of 400 goats (0.75%) were observed. The tumor was only observed in animals in which the perineal area was despigmented. The high incidence of this tumor appears to be due to lack of pigmentation at the períneo and the high and short tail of the goats, that exposes the area to intense ultraviolet radiation in the tropics.
Acesso aberto (Open Access)
Equívocos arraigados no meio pecuário sobre deficiências e suplementação minerais em bovinos no Brasil
(2014-03) MALAFAIA, Pedro Antônio Muniz; COSTA, Rogerio Magnoli; BRITO, Marilene de Farias; PEIXOTO, Paulo Fernando de Vargas; BARBOSA NETO, José Diomedes; TOKARNIA, Carlos Maria Antônio Hubinger; DÖBEREINER, Jürgen
The economic importance of mineral deficiencies in cattle and their supplementation for animal health and production is well established. But in spite of the existing knowledge and conscience of professionals on this subject in Brazil, there are numerous erroneous interpretations and superstitions on mineral supplementation for cattle, together with indiscriminate commercialization of mineral mixtures; the latter, thoroughly accepted and applied in the rural area, causes considerable economic losses to the cattle industry. In this article of general interest we discuss, one by one, the most important misunderstandings and superstitions regarding this subject.
Acesso aberto (Open Access)
Estudo comparativo da toxidez de Palicourea juruana (Rubiaceae) para búfalos e bovinos
(2004-03) OLIVEIRA, Carlos Magno Chaves; BARBOSA NETO, José Diomedes; MACÊDO, Raquel Soares Cavaleiro de; BRITO, Marilene de Farias; PEIXOTO, Paulo Fernando de Vargas; TOKARNIA, Carlos Maria Antônio Hubinger
An experimental study was performed to establish the toxicity of Palicourea juruana for buffaloes and to add new data on the toxicity of this plant for cattle. The clinical and pathological pictures were similar, but a comparison of the lethal doses for buffaloes (1-2g/kg) and cattle (0.25g/kg) shows that the buffalo is at least 4 times more resistant. In experiments performed 10 years earlier with the fresh leaves - collected on the same farm in July, at the beginning of the dry season, only 2 months later than in this second experimental series - the lethal dose for cattle was 2 g/kg. No explanation was found for the extremely high toxicity of the plant observed in the present study.
Acesso aberto (Open Access)
Fotossensibilização hepatógena em eqüinos pela ingestão de Brachiaria humidicola (Gramineae) no estado do Pará
(2006-09) BARBOSA NETO, José Diomedes; OLIVEIRA, Carlos Magno Chaves; TOKARNIA, Carlos Maria Antônio Hubinger; PEIXOTO, Paulo Fernando de Vargas
Data on the clinical-pathological aspects and on the epidemioloy of a disease in horses, characterized by phototsensitization, which occurs in northeastern of Pará, Brazil, are presented. Of a total of 40 horses examined clinically, post-mortem examination was performed on seven. Due to the characteristic lesions found on the non-pigmented skin, the macroscopic and histological alterations in the liver, and knowing that Brachiaria grasses contain saponins with toxic properties, which cause liver lesions and photosensitization in cattle and sheep, it is concluded that this disease in horses is caused by grassing exclusively Brachiaria humidicola.
Acesso aberto (Open Access)
Intoxicações experimental e natural por Ipomoea asarifolia (Convolvulaceae) em búfalos e outros ruminantes
(2005-12) BARBOSA NETO, José Diomedes; OLIVEIRA, Carlos Magno Chaves; DUARTE, Marcos Dutra; PEIXOTO, Paulo Fernando de Vargas; TOKARNIA, Carlos Maria Antônio Hubinger
Ipomoea asarifolia R. et Schult. is a plant responsible for occasional outbreaks of poisoning in cattle, sheep and goats. Its oral administration to cattle and buffalos showed that the buffalo is as susceptible as cattle. One to 4 daily doses of 10-20g/kg caused similar symptoms in both species, as incoordination, muscular twiching and swaying of the head and anterior part of the body (pendular movement). In buffaloes the signs of incoordination were observed to a smaller extent. There is no report yet on natural poisoning by I. asarifolia in buffaloes, possibly because cases are not being noticed.
Acesso aberto (Open Access)
Princípios de suplementação mineral em ruminantes
(2005-09) PEIXOTO, Paulo Fernando de Vargas; MALAFAIA, Pedro Antônio Muniz; BARBOSA NETO, José Diomedes; TOKARNIA, Carlos Maria Antônio Hubinger
Although there is solid knowledge on mineral deficiencies and their consequences on health and productivity of cattle in Brazil, paradoxically, those informations, most of the time, are not used by professionals of the agricultural sciences, who persist in stimulating the widespread use of the so-called complete mineral mixtures. The deficiency of many minerals included in these supplements, as iron, chrome, sulfur, and others, do not occur under natural conditions or only in rare and very particular situations. The present paper deals with the misunderstandings and problems related to traditional mineral supplementation and discusses the main aspects of the so-called selective mineral supplementation that is based in supplying exclusively the deficient mineral(s) and these only in necessary amounts. This procedure can result in expressive economy (sometimes up to 700%) when compared with the commercial mineral supplementation usually employed. According to several estimates, mineral supplementation can account for 20 to 30% of the total cost of beef cattle production on tropical pastures. A reversion assay, in which a group of cattle receives the commercial mineral mixture routinely used on the farm, and another group which receives the selective supplement, is the best option for the elucidation of positive or negative effects between the two possibilities of mineral supplementation on a specific farm. Trough this assay, the effects of the two compositions of mineral supplements can be investigated rationally over a sufficient period of time, with no risks and minimal possibilities of economic losses.
Acesso aberto (Open Access)
Surtos de Enteropatia Proliferativa Hemorrágica (Lawsonia intracelullaris) em suínos no Estado do Rio de Janeiro
(2008-03) FRANÇA, Ticiana do Nascimento; RIBEIRO, Carlos Torres; BEZERRA JÚNIOR, Pedro Soares; DÖBEREINER, Jürgen; CERQUEIRA, Valíria Duarte; PEIXOTO, Paulo Fernando de Vargas
Outbreaks of infection of swine with Lawsonia intracelullaris in the state of Rio de Janeiro are described. The symptomathology was characterized by bloody diarrhea with peracute course. Postmortem findings were pale organs and tissues, reticulate aspect of the ileum with its mucosa moderately thickened nad contained large amounts of partially coagulated blood. Histopathological examination revealed hyperplastic epithelial cell proliferation of the Lieberkühn crypts, sometimes associated with inflammatory and necrotic alterations. Immunohistochemistry demonstrated the presence of large amounts of bacteria in the cytoplasm of the cryptal epithelial cells. L. intracellularis was also seen by ultramicroscopic examination. These outbreaks occurred in 1987 and this is the first report of the disease in the state of Rio de Janeiro.