Bovine herpesvirus meningoencephalitis in the State of Tocantins, Brazil.

Three outbreaks of herpesvirus meningoencephalitis in cattle have been reported in three municipalities in the northern region of the State of Tocantins, Brazil. In one outbreak, 41 predominantly young bovines were affected, with 2-3 deaths in some cases. The animals showed neurological signs of incoordination, blindness, and recumbency, with death occurring within approximately 4-5 d. At necropsy, hyperemia and leptomeningeal hemorrhages were observed in the brain. Histology revealed more intense lesions in the rostral portions of the brain, mainly affecting the frontoparietal cerebral cortex, with nonsuppurative encephalitis and meningitis, glial nodules, neuronophagia, and eosinophilic intranuclear inclusion bodies in the astrocytes and neurons. This study shows the presence of bovine herpesvirus in Tocantins, probably the highly neurotropic type 5 strain, and emphasizes its importance in the differential diagnosis of bovine neuropathies.

Três surtos de meningoencefalite por herpesvírus em bovinos são relatados em três municípios da região norte do Estado do Tocantins, Brasil. Num surto, 41 animais predominantemente jovens foram afetados, com 2-3 mortes nos outros casos. Os animais apresentaram sinais neurológicos de incoordenação, cegueira e decúbito, com a morte ocorrendo em aproximadamente 4 a 5 dias. Na necropsia foram observadas hiperemia e hemorragias leptomeníngeas no encéfalo. A histologia revelou lesões mais intensas nas porções rostrais do encéfalo, principalmente no córtex cerebral frontoparietal, com encefalite e meningite não supurativas, nódulos gliais, neuronofagia e corpúsculos de inclusão intranucleares eosinofílicos nos astrócitos e neurônios. Este estudo demonstra a presença do herpesvírus bovino no Tocantins, provavelmente a cepa tipo 5 altamente neurotrópica, e enfatiza sua importância no diagnóstico diferencial das neuropatias bovinas.

Effects of trichlorfon organophosphate on the morphology of the gills and liver of Pseudoplatystoma corruscans.

Possible changes in the morphology of the gills and liver of P. corruscans after exposure to TCF were evaluated. The fish were distributed into five groups in triplicate (n = 10 in each group: 0.0; 0.125; 0.25; 0.5; 1.0 mg/L of the commercial product NEGUVON®, for 96 h. TCF induced a high histopathological index associated with circulatory disorders (congestion and aneurysm), as well as progressive changes (lamellar hyperplasia, capillary dilation, epithelial detachment and edema) at the highest concentrations (0.25; 0.5 and 1.0 mg/L). In addition to the histopathological disturbances, there was an increase in the levels of neutral glycoproteins and alterations in the histomorphometry of the secondary lamellae (total height, apical region, median, basal and interlamellar) at the highest concentrations. In the liver, the alterations were more intensified, in addition to circulatory (congestion) and regressive disturbances (loss of hepatocyte architecture and accumulation of intracellular substances), progressive alterations (focal necrosis) were observed, indicating a high degree of hepatic tissue involvement. The results indicate that the use of TCF concentrations above 0.25 mg/L promotes histopathological, histomorphometric and histochemical changes in the gills and liver of P. corruscans, imposing a biological risk that affects the aquatic environment and the health of fish.

Use of biomarkers to evaluate the ecological risk of xenobiotics associated with agriculture.

This research aimed to evaluate the ecological risk of xenobiotics associated with agricultural activities by determining metal contents and biomarker responses using tucunaré (Cichla sp.) as a bioindicator. The work was conducted in the southwest region of the state of Tocantins, in the cities of Lagoa da Confusão and Pium. Water samples and specimens of Cichla sp. were collected in the Javaés and Formoso Rivers at three collection points (A, B and C). The concentrations of Cd, Pb, Cu, Cr, Mn, Ni and Zn in water and fish were analyzed. In fish, genotoxic, biochemical (glucose serum levels, AST (aspartate aminotransferase) and ALT (alanine aminotransferase) and histological (gills and liver) biomarkers were assessed. In the water, the Cr and Mn concentrations at the three collection points exceeded the values for Class 1 rivers. In the muscle, Cr was above the maximum limit allowed for human consumption at the three collection points, although the values at Points B and C were not significantly different from that at Point A (p > 0.05). At the three collection points, the micronucleus test revealed a low frequency of micronuclei. Significant hyperglycemia and a decrease in the AST activity of the fish collected at Point C was observed. In the gills, the most frequent alterations were at Stages I and II, which indicated mild to moderate damage, and epithelial detachment was the most frequent variation. In the liver tissue, the most frequently observed histological changes were at Stages I and II and included cytoplasmic vacuolization, nuclear hypertrophy, dilated sinusoids and bile stagnation. The integrated evaluation of these biomarkers indicated that fish collected from areas with intense agricultural activities presented adaptive responses that were likely caused by the availability and bioaccumulation of certain xenobiotics in the environment.

Anatomopatologia de amostras de bovinos alimentados com glicerol / Anatomic-pathological samples of cattle fed with glycerol

O aumento na produção de biodiesel vem acompanhado do incremento na geração de subprodutos, dentre os quais a glicerina bruta e o glicerol, que vem sendo objeto de inúmeros trabalhos em que se destaca seu uso como fonte energética para alimentação de animais de produção. Entretanto, sua utilização tem sido observada com atenção devido à presença de contaminantes como o metanol, utilizado no processo de separação dos ácidos graxos do glicerol. O metanol é um álcool e tem sido responsável por intoxicações, principalmente em seres humanos e primatas, caracterizadas por acidose metabólica e problemas oculares, apresentando menor toxidade a outras espécies animais. Os efeitos tóxicos da intoxicação por metanol são atribuídos principalmente ao ácido fórmico, um metabólito do processo de degradação do metanol no fígado. Objetivou-se com esse estudo verificar a possível ação tóxica da glicerina bruta e do metanol por análises histopatológicas do sistema nervoso central (SNC), fígado, rúmen, intestino delgado e rim de 24 bovinos confinados por 84 dias, consumindo rações contendo até 24% de glicerina bruta na matéria seca (MS),a qual apresentava 80,35% de glicerol, e <0,01% de metanol. À análise histopatológica, não foram observadas alterações patológicas em amostras provenientes de vacas e novilhos de raças de aptidão leiteira com até 24% de inclusão de glicerol com base na MS, da dieta. O ganho de peso total e a conversão alimentar não foram afetados pela inclusão da glicerol. Conclui-se que a glicerina bruta pode ser incluída até 24% da MS total nas dietas de novilhos e vacas de aptidão leiteira sem comprometer o desempenho dos animais e apresentar toxicidade.

The increase in biodiesel production has led to higher production of crude glycerin, thus, numerous studies have highlighted the use of crude glycerin and glycerol as energy source to be used for animal feed production. However, its use has been closely watched because of the presence of contaminants such as methanol used in the process of separating fatty acids from glycerol. Methanol is an alcohol and has been responsible for intoxication in humans and primates, characterized by metabolic acidosis and eye problems, with less toxicity to other species. The toxic effects of methanol poisoning are attributed mainly to formic acid, a metabolite of the degradation process of methanol in the liver. The objective of this study was to verify the possible toxic action of crude glycerin and methanol by pathological examinations of the central nervous system (CNS), liver, rumen, small intestine and kidney from 24 feedlot cattle for 84 days, feed containing up to 24% of crude glycerin in dry matter (DM) presenting in its composition 80.35% glycerol, and <0.01% methanol. There were no pathological changes observed in dairy cows and steers up to 24% of glycerol inclusion based on the diet DM. The total weight gain and feed conversion were not affected by inclusion of glycerol. We conclude that crude glycerin can be included up to 24% of total DM in the diets of steers and dairy cows without compromising animal performance or display toxicity.

Response of mucous cells of the gills of traíra (Hoplias malabaricus) and jeju (Hoplerythrinus unitaeniatus) (Teleostei: Erythrinidae) to hypo- and hyper-osmotic ion stress

The mucous cells (MC) of traíra, Hoplias malabaricus, and jeju, Hoplerythrinus unitaeniatus, two ecologically distinct erythrinid species, were analyzed in fish exposed to deionized (DW) and high ion concentration (NaCl and Ca2+) water (HIW) during 15 days to evaluate the MC responses to ion challenge. MCs are localized in the leading and trailing edge and, interlamellar region of the gill filament epithelium but, in H. unitaeniatus, they are also found in the breathing or lamellar epithelium. MC density is lower in H. malabaricus, the exclusively water-breathing fish, than in H. unitaeniatus, a facultative air-breathing fish. The transference to DW or HIW did not change the MC density and surface area, excepting in H. malabaricus, in the first day of exposure to DW. A single MC containing three types of glycoproteins (neutral, acidic and sulphated) was identified in the gill epithelium of both, H. malabaricus and H. unitaeniatus. The amount (based on the intensity of histochemistry reaction) of these glycoproteins differed between the species and were altered after exposure to DW and HIW showing little adjustments in the amount of mucosubstances in the MC of H. malabaricus and reduction of acidic and sulphated glycoproteins in H. unitaeniatus. The decreasing of these glycoproteins in H. unitaeniatus reduced the mucus protection against desiccation of gill tissue when change the ion concentration in water.(AU)

As células mucosas (CM) em traíra, Hoplias malabaricus, e jeju, Hoplerythrinus unitaeniatus, dois eritrinídeos ecologicamente distintos, foram analisadas em espécimes expostos a água deionizada (DW) e água com alta concentração de íons (NaCl + Ca2+, HIW) durante 15 dias para avaliar as respostas das CMs. As CMs estão localizadas no lado aferente e eferente e região interlamelar no epitélio do filamento branquial, mas em H. unitaeniatus, CMs estão presentes no epitélio respiratório ou lamelar. A densidade de CMs é menor em H. malabaricus, espécie com respiração exclusivamente aquática, do que em H. unitaeniatus, espécie com respiração aérea facultativa. A transferência para AD e HIW não alterou a densidade de CMs e a sua superfície, exceto em H. malabaricus, no primeiro dia de exposição à AD. Um único tipo de CM contendo três tipos de glicoproteínas (neutra, ácida e ácida sulfatada) foi identificado no epitélio branquial de H. malabaricus e H. unitaeniatus. A quantidade das glicoproteínas (avaliada pela intensidade da reação histoquímica) diferiu nas duas espécies e foi alterada após a transferência para AD e HIW mostrando pequeno ajuste na quantidade de cada mucosubstância secretada pelas CMs em H. malabaricus e redução de glicoproteínas ácidas e sulfatadas em H. unitaeniatus. A diminuição dessas glicoproteínas em H. unitaeniatus reduz a proteção do muco sobre o tecido branquial quando é alterada a concentração de íons na da água.(AU)

Chloride cell responses to ion challenge in two tropical freshwater fish, the erythrinids Hoplias malabaricus and Hoplerythrinus unitaeniatus.

Chloride cell (CC) responses to ion challenge and plasma ion concentration were evaluated in two ecologically distinct erythrinids, Hoplias malabaricus, an exclusively water-breathing species, and Hoplerythrinus unitaeniatus, a facultative air-breathing fish, at one, two, seven, and 15 days of exposure to deionized water and to ion-rich water. H. malabaricus displayed high CC proliferation on filament and lamellar epithelium during exposure to deionized water and significant CC proliferation in the filament epithelium on the first day of exposure to water rich in NaCl and Ca2+ and in the lamellar epithelium on the first, second, and seventh day of exposure to such water. CC proliferation in H. unitaeniatus occurred only in the lamellar epithelium of fish exposed to deionized water. CC proliferation on both species was not accompanied by significant increase of CC density in contact with the external medium. The increase in the CC fractional area (CCFA) resulted from the increase of individual CC apical surface area on the first and second days of exposure to deionized water in H. malabaricus and only on the first day in H. unitaeniatus. Plasma ions in both erythrinid species showed transitory changes and, on the fifteenth day of exposure to the two types of experimental water, the plasma ion concentration was similar to the control fish. The CC responses of these erythrinid fish showed that CC proliferation depends on previous CC density in the gill and is not related solely to exposure to ion-poor water. Furthermore, CC proliferation in gill epithelium did not always involve an increase of CC density in contact with the external medium.