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Результаты 541-550 из 575
Determination of acute median lethal concentration and sublethal effects on AChE activity of Gymnotus carapo (Teleostei: Gymnotidae) exposed to trichlorfon
2020
Giovanni Henrique Ferri | Israel Luz Cardoso | Juliana Augusta Gil | Claudio Martin Jonsson | Francisco Tadeu Rantin | Márcia Mayumi Ishikawa
Trichlorfon (TRF) is a pesticide widely used in aquaculture to control fish ectoparasites. This pesticide is an inhibitor of acetylcholinesterase, an essential enzyme for termination of nerve impulses. High rates of TRF use generate risks to the environment and human health. In the environment, pesticides can affect the local fauna and generate an ecological breakdown. There are several studies performed with fish production; however, gaps are created for native fish with other commercial values. The tuvira (Gymnotus carapo) is a fish native to Brazilian fauna and has great commercial importance in sport fishing. The present study aimed to determine the lethal concentration of trichlorfon (Masoten) in Gymnotus carapo and its sublethal effects on the enzyme AChE. In this study, the acute toxicity (the concentrations to kill 50% of the fish LC50) of TRF in tuviras (Gymnotus carapo) and acetylcholinesterase inhibition in liver and muscle tissue of tuviras submitted to sublethal concentrations were evaluated. For the acute assay, concentrations of 0.0, 5.0, 7.5, 15, 22.5, 30, 37.5 and 45 mg L-1 were used for a period of 96 h. After the acute exposure period, a LC50 of 6.38 mg L-1 was determined. In the sublethal assay, concentrations of 0.0, 0.238, 0.438 and 0.638 mg L-1 were used, based on 10% of the LC50, over a period of 14 days. Two collections were performed: one at seven days and the other at the end (day 14). Inhibition of acetylcholinesterase in the liver was only shown (p < 0.05) for the treatment with 0.638 mg L-1 after 14 days of exposure. At seven days, muscle activity showed a significant difference only for the treatments 0.438 and 0.638 mg L-1, compared with the treatment 0.238 mg L-1 and control. At 14 days of exposure, only the treatment 0.638 mg L-1 showed significant differences in relation to the other groups, thus showing that enzyme recovery had occurred. The value found in the acute test allowed the conclusion that TRF presents moderately toxic characteristics to Gymnotus carapo. The toxicity parameter values calculated in the present study assisted in estimation of maximum allowable limits in bodies of water when combined with test data from other non-target organisms.
Показать больше [+] Меньше [-]Feeding behavior of cockatiels in captivity
2020
Priscilla Pimentel Freitas | Vanair Carlos da Paz | Rodrigo Diana Navarro
In nature, cockatiel (Nymphicus hollandicus) feed consists of a huge variety of seeds, fruits, flowers, leaves, and insects. In captivity, their feed is generally poor, as many breeders offer only a mixture of seeds as food, leading to nutrient deficiency and even obesity. This paper presents a study on cockatiel feeding behavior in artificial environments at different stages of development (growth, maintenance, and reproduction), to evaluate their preference from the offer of six different food types (sunflower seed, oats, millet, rice, ration, and a cornmeal based feed or farinhada), and an analysis of their preferences for locations in the cage. No significant differences were observed about the final weight of the birds during the stages of development. Consumption of millet seeds was significantly higher in the growth stage, but at this stage, the birds showed a preference for oats. On the other hand, at the reproduction and maintenance stages, they showed a preference for sunflower seeds. The birds in the reproduction stage were the ones that visited the nest, and the nest grid, the most. Among all the cage locations, all birds showed a preference for the perches.
Показать больше [+] Меньше [-]Uterine intussusception in immediate postpartum in bitches
2020
Daniel de Souza Ramos Angrimani | Matheus Felipe Silva | Amanda Moraes Ilkiu | Eduardo Santos Rossi | Isadora Mestriner Rodrigues | Viviane Maria Codognoto | João Carlos Pinheiro Ferreira
Uterine intussusception is a rare condition in bitches. This study aimed to report an unusual case of prolapsed uterine intussusception in a female dog. A 2-year-old American Bully bitch was received with labor history of large fetus requiring manual traction. The animal presented mucosal prolapse through the vulva, unproductive contractions and abdominal discomfort. After partial correction of mucosal prolapse, the dog was referred to ovary-hysterectomy surgery to correct prolapsed mucosa. During the surgical procedure, surgeons observed that the uterine horns were invaginated into the uterine body, rotated, and the tissue was slightly devitalized and congested. As previously described, this condition occurred during the immediate postpartum period. Thus, we suggest that this period can be a facilitator for the establishment of uterine intussusception.
Показать больше [+] Меньше [-]Evolution of Avian coronavirus (AvCoV) in BHK-21 and VERO cells
2020
Paulo Eduardo Brandão | Beatriz Alcântara Leite | Sueli Akemi Taniwaki Miyagi
Avian coronavirus (AvCoV) infects a range of tissues in chickens and several other avian species. Although the virus can be isolated in chicken embryos, only a few strains of the 6 genotypes/33 lineages can grow in cell lines, with the Beaudette strain (GI-1 lineage) being the most used for in vitro studies. Considering the differences between cell lines and chicken embryos as habitats for AvCoV, this study aimed to assess the diversity of the genes coding for the nonstructural protein 3 (nsp3) and spike envelope protein (S) after serial passages in BHK-21 and Vero cells. After 14 passages of an embryo-adapted Beaudette strain, the virus loads fluctuated in both cell lines, with the highest loads being 8.72 log genome copies/µL for Vero and 6.36 log genome copies/µL for BHK-21 cells. No polymorphisms were found for nsp3; regarding S, not only aa substitutions (Vero: 8th passage A150S, and 14th S150A; BHK-21: 4th S53F, 8th F53Y, and 8th S95R), but also minor variants could be detected on chromatograms with fluctuating intensities. As the regions of these aa substitutions are within the receptor-binding domain of S, it can be speculated that differences in cell receptors between Vero and BHK-21 cells and the speed of cell death led to the selection of different dominant strains, while the stability of nsp3 supports its function as a protease involved in AvCoV replication. In conclusion, AvCoV quasispecies evolution is influenced by the biological model under consideration, and a gradual transition is seen for minor and major variants.
Показать больше [+] Меньше [-]Occurrence of geohelminths in the soil of public squares in Rio Branco, Acre State, Brazilian Western Amazon
2020
Jefté Teixeira da Silva | Keli Pinheiro Menezes | Leonardo Augusto Kohara Melchior | Vânia Lúcia Brandão Nunes | Andreia Fernandes Brilhante
Soil contamination by dog and cat feces can become a public health problem due to the transmission of various etiologic agents that cause zoonoses. This study aimed to verify the occurrence of geohelminths in the soil of some public square areas of the municipality of Rio Branco, Acre State, Western Brazilian Amazon. Five public squares were selected, and soil samples collection was performed from April 2014 to March 2015. The samples were processed by using the Baermann-Moraes and centrifugal‑flotation methods. Geohelminths positivity was of 25% for Toxocara spp., 6.6% for the Ancylostomatoidea Superfamily and 1.6 for Trichuris spp.. Measures should be implemented to prevent the free access of animals to these places, as well as deworming of stray dogs and cats and the implementation of population control and policies for such animals.
Показать больше [+] Меньше [-]Adrenal function evaluation in critically ill dogs with low doses of synthetic ACTH
2020
Márcia Marques Jericó | Fernando Mathias Bento | Ricardo Duarte Silva | Felipe Braz de Siqueira Cardozo | Fabiano de Granville Ponce | Rogério Márcio Soila | Priscila Viau Furtado | Fabrício Lorenzini Aranha Machado
The hypothalamus-pituitary-adrenal axis function may be impaired in patients with critical illnesses, especially cases of sepsis, named critical illness-related corticosteroid insufficiency (CIRCI). This study examined the function of the hypothalamic-pituitary-adrenal axis in normal dogs (n = 10) and dogs with critical diseases (n = 16), through determinations of endogenous ACTH (adrenocorticotropic hormone), basal cortisol and cortisol after stimulation in low doses of synthetic ACTH (1.0μg/kg/IV). The stimulation test with ACTH dose tested was verified as effective for evaluation of adrenal function in healthy and sick dogs. Ill dogs differed from healthy dogs by presenting higher basal cortisol values. Eight sick dogs presented a decrease in endogenous ACTH, basal cortisol, or Δ-cortisol. No significant differences were found between the control groups and critically ill dogs for the values of endogenous ACTH, cortisol after stimulation or Δ-cortisol. We concluded that the stimulation test with low-dose ACTH was effective for evaluation of adrenal function, as well as the fact that a considerable portion of critically ill dogs studied here, especially with sepsis, had evidence of inadequate corticosteroid response to stress.
Показать больше [+] Меньше [-]Evaluation of post-operative pain and stress in dogs after elective ovariohysterectomy under hospitalization
2020
Nathália Gonçalves de Santana | Christina Malm | Mariana Zanini Maia | Tábata Megda | Suzane Lilian Beier | Leonardo Dias Mamão | Thaíssa Castro Franco
Surgical procedures in pet animals are usually associated with some degree of stress and pain. Hospitalization is one stress-triggering factor. The present study aimed to evaluate the degree of stress and pain during hospitalization of female dogs submitted to elective ovariohysterectomy (OVH) and to investigate the influence of hospitalization on the stress of these animals. Fifteen young adult crossbreed female dogs were divided into two groups: eight animals without surgery (Group 1 - control) and seven animals submitted to surgery (Group 2 - OVH). Pain and stress were evaluated. Visual analogue scale (VAS), simple descriptive pain scale (SDS) and modified Glasgow pain scale (MGPS) were used. Serum cortisol (μg/dL) and glucose (mg/dl) were also measured. No statistical difference was observed for cortisol (μg/dL) between the two groups. Despite the absence of statistical difference between groups and times, mean serum cortisol (μg/dL) values exceeded the normal values for the canine species at various times evaluated. Hyperglycemia was only observed at T4 in the OVH group. It was concluded that the hospitalization of animals was more relevant in the establishment of stress than the surgical procedure and associated pain. The influence of stress was a relevant factor in the results of assessments carried out using the MGPS.
Показать больше [+] Меньше [-]Hematological values for free-living great fruit-eating bats, Artibeus lituratus (Chiroptera: Phyllostomidae)
2020
Maria Alice Amaral Kuzel | Jonatas Amorim Tavares | Priscila do Amaral Fernandes | Bruno Alves | Sócrates Fraga de Costa Neto | Caroline Lacorte | Mylena de Souza Borges | Isabel Cristina Fábregas Bonna | Cecilia Siliansky de Andreazzi | Ricardo Moratelli
It was provide a hematological profile of Artibeus lituratus (Phyllostomidae: Stenodermatinae). Animals were collected from October 2017 to February 2018 in an urban forest in the city of Rio de Janeiro, Southeastern Brazil. Males and females showed similar overall mean values for the parameters analyzed. Males had higher values for erythrocytes (RBC), hematocrit and basophils. Females had higher levels of eosinophils than males. The hematological values reported here will serve as reference for future research on health conditions of free-living and captive populations of Artibeus lituratus, as well as for research on pathogens associated with these bats.
Показать больше [+] Меньше [-]Serum anti-Toxoplasma gondii antibodies in Passer domesticus (Linnaeus, 1758) (Passeriformes: Passeridae), in the municipality of Pelotas, RS, Brazil
2020
Luciana Siqueira Silveira dos Santos | Herbert Sousa Soares | Carolina Silveira Mascarenhas | Paulo Roberto Silveira dos Santos | Solange Maria Gennari | Nara Amélia da Rosa Farias
The objective of this study was to detect the presence of anti-Toxoplasma gondii antibodies in serum samples from 100 sparrows (Passer domesticus Linnaeus, 1758) that were caught in an urban area in southern Brazil. The modified agglutination test (MAT) was used to investigate anti-T. gondii antibodies and samples with a cut-off dilution > 5 were considered positive. Among the 100 serum samples analyzed, 80 (80%) were reactive. These results demonstrate that P. domesticus may play an important role in the epidemiological chain of T. gondii, since it is widely distributed throughout Brazil, and it may act as a source of infection to domestic, semi-domestic cats and to free-living wild felids.
Показать больше [+] Меньше [-]Epidemiological surveillance of West Nile virus in the world and Brazil
2020
Erica Azevedo Costa | José Joffre Martins Bayeux | Aila Solimar Gonçalves Silva | Guilherme Alves de Queiroz | Beatriz Senra Álvares da Silva Santos | Marcele Neves Rocha | Izabelle Silva Rehfeld | Luisa Feliciano de Souza Franklin | Livia Braga Valle | Maria Isabel Maldonado Coelho Guedes | Raffaella Bertoni Cavalcanti Teixeira
West Nile virus (WNV) is a neurovirulent mosquito-borne Flavivirus that is maintained in nature by a zoonotic transmission cycle between avian hosts and ornithophilic mosquito vectors, mostly from the Culex genus. Until the 1990s, WNV was considered to be an old-world arbovirus, but in 1999, WNV emerged in the United States (US) and spread rapidly, becoming a major threat to public health. WNV adapted to the transmission cycle involving American mosquitoes and birds and reached Central and South America in subsequent years. In 2003, the National West Nile Fever Surveillance System was created in Brazil based on serological screening of animals and sentinel vectors, as recommended by the Pan American Health Organization (PAHO) and the World Health Organization (WHO). Since 2008, serological evidence of WNV infection in Brazilian horses has been reported, and the circulation of WNV has been monitored through the regular serological screening of sentinel horses and reporting of encephalomyelitis cases. Horses are highly susceptible to WNV infection, and outbreaks of neurological disease among horses often precede human cases. In this regard, equine surveillance has been essential in providing early warning to public and animal health authorities in several countries, including Brazil. This demonstrates the need for animal and public health intervention programs to allocate resources to make veterinarians aware of the role they can play in the human surveillance processes by monitoring horses. This review discusses the importance of equine surveillance and the gap that veterinarians can fill on the front line in human surveillance, in Brazil and worldwide, in the context of “One Health”
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