Institute Veterinaria

Seropédica, Brazil

Institute Veterinaria

Seropédica, Brazil
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Pinheiro J.,Institute Biologia | Franco-Acuna D.O.,Institute Veterinaria | Oliveira-Menezes A.,Secretaria Municipal de Educacao do Rio de Janeiro | Oliveira-Menezes A.,Institute Biofisica Carlos Chagas Filho | And 3 more authors.
Veterinary Parasitology | Year: 2011

The digenetic trematode Eurytrema coelomaticum is a parasite of pancreatic ducts of ruminants. The ultrastructure of the mother and daughter sporocysts of E. coelomaticum was analyzed. The mother sporocyst was attached to the coelome of the intestine wall of intermediate snail host Bradybaena similaris, intimately adhered in some regions. It presents a highly folded tegument with granules and the body wall was composed by an outer syncitial layer, basal lamina, and circular and longitudinal muscle layer. Below was the cell body (cyton) with the nucleus. The daughter sporocysts obtained by dissection exhibited many granules and secretory vesicle in the outer layer indicating an intense secretory activity. The body wall presented the same layers of the mother sporocysts, but the outer syncitial layer invaginated and an amorphous layer was present between the syncitial and circular muscle layers. The protonephridial excretory system was viewed. The anterior and posterior end of the expelled sporocyst exhibit a degenerated structure, but biological activity still occurred in these regions. The swollen middle of the body was filled by a lamellar structure formed by degenerating membranes, but the excretory system was preserved. The endocyst wall was fibrilar and filled by cercariae and amorphous, membranous and secretory material inside it. These results were discussed. © 2011 Elsevier B.V.


Gaudencio F.N.,Institute Ciencias Biologicas e da Saude | Klafke G.M.,Institute Pesquisas Veterinarias Desiderio Finamor | Tunholi-Alves V.M.,Institute Ciencias Biologicas e da Saude | Ferreira T.P.,Institute Veterinaria | And 4 more authors.
Parasitology International | Year: 2017

The objective of this study was to assess the effect of the exposure to fluazuron on the activity of common pesticide detoxification enzyme groups in the cattle tick (Rhipicephalus microplus). Engorged females of a susceptible strain (POA) and a resistant strain (Jaguar) were exposed in vitro to fluazuron and their eggs and larvae were used to compare the activities of the general esterases, mixed-function oxidases (MFO) and glutathione-S-transferase (GST). The results showed significant elevation in MFO contents and esterases activity in the resistant strain when compared with the susceptible strain, in eggs and larvae respectively. In the POA strain, the MFO activity in eggs was down-regulated by fluazuron exposure. Based on these results, it can be concluded that different detoxification enzymes can act in distinct pathways depending on the tick's development stage, and may be related to fluazuron detoxification in resistant strains. © 2017 Elsevier B.V.


Tunholi-Alves V.M.,Federal Rural University of Rio de Janeiro | Tunholi-Alves V.M.,Institute Veterinaria | Tunholi V.M.,Federal Rural University of Rio de Janeiro | Tunholi V.M.,Institute Veterinaria | And 2 more authors.
Experimental Parasitology | Year: 2012

The effect of infection by Angiostrongylus cantonensis on the activity of the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the concentration of total proteins, uric acid and urea in the hemolymph of Biomphalaria glabrata were investigated. The snails were dissected after 1, 2 and 3. weeks of infection to collect the hemolymph. The infection by A. cantonensis induced severe changes in the host snail's metabolism, triggering physiological mechanisms to minimize the deleterious effects caused by the larvae. There was a significant decrease in the concentration of total proteins in the infected snails, which occurred gradually as the infection advanced. This change was accompanied by an increase in the concentrations of urea and a decrease in the levels of uric acid in the hemolymph, suggesting that in this model the infection induces proteolysis and inversion of the excretion pattern of the infected snails. Besides this, variations in the activities of the aminotransferases were observed, with significantly higher levels in the infected groups than in the control group. These results indicate an increase in the protein metabolism of the infected snails, since there was an increase in nitrogen catabolites such as urea. © 2012 Elsevier Inc.


Franco-Acuna D.O.,Institute Veterinaria | Pinheiro J.,Institute Biologia | Brandolini S.V.P.B.,Institute Biologia | de Souza W.,Institute Biofisica Carlos Chagas Filho
Veterinary Parasitology | Year: 2011

Eurytrema coelomaticum is a fluke that infects ruminants in South America, Europe and Asia. The morphology of the mother and daughter sporocysts of E. coelomaticum obtained from Bradybaena similaris, the first intermediate host, is described for the first time by light and scanning electron microscopy. The intermediate host was exposed to E. coelomaticum eggs and after 30 days the mother sporocyst was found in the coelom adhered to the intestine wall. This sporocyst was a rounded or elongated mass (0.1078 mm), with numerous germinal balls in it, and a folded tegument with no specializations. The daughter sporocysts obtained following dissection of infected snails have varied shape, one hollow tapered region with many transversal and longitudinal striations, named anterior end. The expelled daughter sporocyst presented an oval sac-like central region with a small anterior and a posterior longer filament-like prolongation. The measures of the expelled sporocysts are presented and compared to previous descriptions. © 2010 Elsevier B.V.


Pinheiro J.,Institute Biologia | Franco-Acuna D.O.,Institute Biologia | Oliveira-Menezes A.,Institute Veterinaria | Oliveira-Menezes A.,Federal University of Rio de Janeiro | And 2 more authors.
Parasitology Research | Year: 2012

Eurytrema coelomaticum is a digenetic trematode that parasitizes the pancreatic ducts of ruminants. In the present study, the morphology of the cercariae was analyzed using light, scanning, and transmission electron microscopies. The size of the larvae was larger than that reported in the literature. An oral sucker with many papillae and an oral aperture in its center and a ventral sucker with few discrete papillae on the edge were observed. No stylet at the anterior end of the larval body and spines on the tegument of the end of the tail were observed. The cercariae had lateral penetration glands and (central) pre-acetabular glands, from which ducts lead to the anterior region and open into a small anterior pocket. The flame cells were located laterally and communicated with fine branches, converging to two lateral excretory collecting ducts that opened into an excretory bladder, centrally located at the posterior end of the body. The tegument presented an external layer loosely attached to the larval body, below which an amorphous syncytial outer layer with many mitochondrial profiles was observed. This region exhibited many secretions and released secretory granules, indicating intense secretory activity. The circular and longitudinal muscle layers were arranged in sequence below the outer layer. The outer layer was connected by cytoplasmic bridges crossing the muscular layers to the internal region of the tegument, where the cell body with nucleus was located. In the cercarial body, it was possible to observe a typical flame cell with the barrel region, where cilia and the internal and external ribbed regions were found. The somatic cells seem to have an active metabolism, with a well-developed endoplasmic reticulum, secretory granules, and evident nuclei. The results are discussed in the light of the biology and taxonomy of this species. © Springer-Verlag 2012.


Tunholi V.M.,Institute Biologia | Lustrino D.,Institute Biologia | Tunholi-Alves V.M.,Institute Biologia | Mello-Silva C.C.C.D.,Instituto Oswaldo Cruz | And 3 more authors.
Journal of Invertebrate Pathology | Year: 2011

The egg-laying rate, number of egg masses, number of eggs/mass, number of eggs hatched/snail and egg viability of Biomphalaria glabrata exposed to different doses (5 and 50) of Echinostoma paraensei miracidia were analyzed as indicators of reproductive activity. Polystyrene plates were placed in aquariums containing the snails and every other day for four weeks after infection the plates were removed to count the number of egg masses and eggs laid. After this, the plates were numbered individually and placed in new aquariums free of snails and the egg masses were observed daily to determine the hatching rate. On average there was an increase in the parameters evaluated in the infected snails in relation to the controls (uninfected snails), except for egg viability, which was significantly lower in the groups infected with 50 miracidia. These findings indicate that when infected, this host snail is able to increase its reproductive activity, suggesting an ecological strategy to maintain the species. © 2010 Elsevier Inc.


Tunholi V.M.,Institute Biologia | Tunholi V.M.,Institute Veterinaria | Lustrino D.,Institute Biologia | Tunholi-Alves V.M.,Institute Biologia | And 5 more authors.
Parasitology Research | Year: 2011

The effect of infection by Echinostoma paraensei on the activity of the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the concentration of total proteins, uric acid and urea in the hemolymph of Biomphalaria glabrata were investigated after exposure to five or 50 miracidia. The biochemical concentrations were measured weekly until the end of the fourth week after exposure. There was a significant decrease in the concentrations of total proteins in the snails exposed both to five and 50 miracidia, as well as an increase in the nitrogenous products of excretion, ALT and AST activities. The higher ALT activity in the hemolymph of the snails after infection with 50 miracidia suggests highest energetic requirement in these snails in relation to snails exposed to five miracidia. The results also suggest an increase in the use of total proteins, since there was increased formation of nitrogenous catabolites, in conformity with an increase in the aminotransferase activities, frequently associated with tissue damages. This can be explained by damage due to penetration by the miracidia and subsequent development of intramolluscan sporocysts and rediae. © 2011 Springer-Verlag.


Tunholi-Alves V.M.,Institute Biologia | Tunholi-Alves V.M.,Institute Veterinaria | Tunholi V.M.,Institute Biologia | Tunholi V.M.,Institute Veterinaria | And 7 more authors.
Parasitology International | Year: 2014

The activity of lactate dehydrogenase and the concentrations of glucose in the hemolymph and of glycogen in the digestive gland and cephalopedal mass of Biomphalaria glabrata experimentally infected with Angiostrongylus cantonensis were evaluated. Additionally, high performance liquid chromatography (HPLC) was used to determine the hemolymph concentrations of some carboxylic acids (oxalic, piruvic, lactic and succinic). After one, two and three weeks of infection, the snails were dissected to collect the hemolymph and separate the tissues. A significant reduction of the levels of glucose in the hemolymph was observed as of the first week of infection in relation to the control group. The lactate dehydrogenase activity of the infected group was significantly higher than the average of the control group. This increase was accompanied by a reduction of the levels of piruvic acid and an increase in the levels of lactic acid in the hemolymph of the parasited snails, confirming the acceleration of the anaerobic metabolism, necessary for the host to obtain energy and maintain its redox balance. In parallel, there was a decrease in the glycogen content of the storage tissues, with that reduction being significantly greater in the cephalopedal mass than the digestive gland, demonstrating that in this interaction system, the mobilization of glycogen was not sufficient to maintain and reestablish the normal glycemia of the infected snails. © 2013 Elsevier Ireland Ltd.


Coelho C.D.,Federal Rural University of Rio de Janeiro | Berto B.P.,Institute Veterinaria | Flausino W.,Institute Veterinaria | Lopes W.G.,Institute Veterinaria
Acta Protozoologica | Year: 2011

This current study reports a new isosporoid (Apicomplexa: Eimeriidae) species parasitizing tropical mockingbirds Mimus gilvus recovered from illegal trade in Brazil. Isospora mimusi n. sp. oocysts are spherical to sub-spherical, 20.6 × 19.6 μm, with smooth, bilayered wall, ~1.2 μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ovoidal, 13.4 × 9.8 μm. Stieda and substieda bodies are present. Sporocyst residuum composed of diffuse granules of various sizes, sporozoites have one refractile body.


PubMed | Institute Veterinaria
Type: Journal Article | Journal: Veterinary parasitology | Year: 2011

Eurytrema coelomaticum is a fluke that infects ruminants in South America, Europe and Asia. The morphology of the mother and daughter sporocysts of E. coelomaticum obtained from Bradybaena similaris, the first intermediate host, is described for the first time by light and scanning electron microscopy. The intermediate host was exposed to E. coelomaticum eggs and after 30 days the mother sporocyst was found in the coelom adhered to the intestine wall. This sporocyst was a rounded or elongated mass (0.1078 mm), with numerous germinal balls in it, and a folded tegument with no specializations. The daughter sporocysts obtained following dissection of infected snails have varied shape, one hollow tapered region with many transversal and longitudinal striations, named anterior end. The expelled daughter sporocyst presented an oval sac-like central region with a small anterior and a posterior longer filament-like prolongation. The measures of the expelled sporocysts are presented and compared to previous descriptions.

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