134 research outputs found
Exploring object discrimination in zebrafish: behavioral performance and scopolamine-induced cognitive deficits at different retention intervals
Eddy diffusivities for the convective boundary layer derived from LES spectral data
AbstractLarge Eddy Simulation (LES) spectral data and Taylor statistical diffusion theory are used to obtain Eddy diffusivities in a convective boundary layer. The derivation employs a fitting expression obtained from LES data for the vertical peak frequency. The vertical Eddy diffusivities are well behaved and show similar patterns and magnitudes as those derived from experimental spectral peak frequency data. In addition, this new vertical Eddy diffusivity was introduced into an advection diffusion equation which was solved by Generalized Integral Laplace Transform Technique (GILLT) method and validated with observed contaminant concentration data of the Copenhagen experiment. The results of this new approach are shown to agree with the measurements of Copenhagen
Naloxone Prolongs Abdominal Constriction Writhing-Like Behavior in a Zebrafish-Based Pain Model
The ability to detect noxious stimuli is essential to survival. However, pathological pain is maladaptive and severely debilitating. Endogenous and exogenous opioids modulate pain responses via opioid receptors, reducing pain sensibility. Due to the high genetic and physiological similarities to rodents and humans, the zebrafish is a valuable tool to assess pain responses and the underlying mechanisms involved in nociception. Although morphine attenuates pain-like responses of zebrafish, there are no data showing if the antagonism of opioid receptors prolongs pain duration in the absence of an exogenous opioid. Here, we investigated whether a common opioid antagonist naloxone affects the abdominal constriction writhing-like response, recently characterized as a zebrafish-based pain behavior. Animals were injected intraperitoneally with acetic acid (5.0%), naloxone (1.25 mg/kg; 2.5 mg/kg; 5.0 mg/kg) or acetic acid with naloxone to investigate the changes in their body curvature for 1 h. Acetic acid elicited a robust pain-like response in zebrafish, as assessed by aberrant abdominal body curvature, while no effects were observed following PBS injection. Although naloxone alone did not alter the frequency and duration of this behavior, it dose-dependently prolonged acetic acid-induced abdominal curvature response. Besides reinforcing the use of the abdominal writhing-like phenotype as a behavioral endpoint to measure acute pain responses in zebrafish models, our novel data suggest a putative role of endogenous opioids in modulating the recovery from pain stimulation in zebrafish. © 2019 Elsevier B.V.We recognize the financial support and fellowships from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) . F.V.C. was recipient of CAPES fellowship. J.C. and F.V.S. receive the CNPq fellowship. D.B.R. is a recipient of CNPq research productivity grant ( 305051/2018-0 ) and his work is also supported by the PROEX/CAPES (process number 23038.005848/2018-31) and PRONEM/FAPERGS (process number 16/2551-0000248-7) fellowship grants. A.V.K. is the Chair of the International Zebrafish Neuroscience Research Consortium (ZNRC). His research is supported by the Russian Science Foundation (RSF) grant 19-15-00053. All authors contributed to the preparation of the manuscript and approved its final version. The funders had no influence on the study design, collection, analysis, and interpretation of data, as well as on writing and submission of this manuscript
Effect of dietary supplementation of Padauk (Pterocarpus soyauxii) leaf on high fat diet/streptozotocin induced diabetes in rats’ brain and platelets
Background
This study investigated the effects of Padauk leaf on brain malondialdehyde (MDA) content, acetylcholinesterase (AChE) activities, ectonucleotidases and adenosine deaminase (ADA) activities in the platelet of high fat diet and streptozotocin (STZ)-induced diabetic rats.
Methods
The animals were divided into six groups (n = 7): normal control rats; diabetic rats + high fat diet (HFD); diabetic rats + HFD + Metformin; diabetic rats + HFD + acarbose; diabetic rats + HFD + 10% Padauk leaf; normal rats + basal diet + 10% Padauk leaf. After 30 days of experiment comprising of acclimatization, dietary manipulation, pre-treatment with STZ and supplementation with Padauk leaf, the animals were sacrificed and the rats’ brain and blood were collected for subsequent analysis.
Results
The results demonstrated that the elevated MDA content and AChE activity in the diabetic rats were significantly reduced when compared with the control rats. Furthermore, the increased NTPDases, 5′-nucleotidase and ADA activities in the diabetic rats were significantly reduced when compared with the control rats.
Conclusion
This study demonstrated that Padauk leaf exhibited modulatory effects on purinergic and cholinergic enzymes involved in the prevention of platelet abnormality and consequent vascular complications in diabetic state
Uso do ricinoleato de gliceril polietilenoglicol como coadjuvante na peletização de ração.
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Use of thermographic imaging in clinical diagnosis of small animal: preliminary note
Introduction. The authors, after a description of the physics of infrared thermographic technique (IRT), analyze the reading of images and the main applications in the veterinary field, compared to the existing literature on the subject and to their experimental researches. IRT lends itself to countless applications in biology, thanks to its characteristics of versatility, lack of invasiveness and high sensitivity. Probably the major limitation to its application in the animal lies in the ease of use and in its extreme sensitivity.
Materials and methods. From September 2009 to October 2010, the experimental investigation with the thermo camera took into consideration 110 animals (92 dogs and 18 cats), without any selection criteria. All patients were brought to the Faculty of Veterinary Medicine in Milan University by the owner, to be examined by a specialist, or to undergo one of the following diagnostic procedures: X-rays, computed tomography, or ultrasound examinations; finally some patients were brought in for surgical procedures. With the consent of the owner, 1 to 10 thermographic images were recorded from each clinical case.
Results. In this first experimental investigation, thermography has shown a high sensitivity (100%), but a low specificity (44%). This figure excludes the use of thermal imaging technology to replace other imaging techniques such as radiography, computed tomography and magnetic resonance imaging. Furthermore, it does not show any ability to recognize the etiology of the disease, but only the thermal alteration, and this is restricting its use. However, this experimental study has demonstrated that thermography can be used in veterinary medicine, and specifically in dogs and cats. It is hoped that in the field of targeted diseases this technique will become an important tool for diagnostic purposes by using working protocols validated and repeatable
Immunophenotype predicts survival time in dogs with chronic lymphocytic leukemia
Background: Chronic lymphocytic leukemia (CLL) is a hematologic disorder in dogs, but studies on prognostic factors and clinical outcome are lacking. In people, several prognostic factors have been identified and currently are used to manage patients and determine therapy.Objectives: The aim of the study was to determine if the immunophenotype of neoplastic cells predicts survival in canine CLL.Design: Retrospective study.Animals: Forty-three dogs with CLL.Procedures: Records of dogs with a final diagnosis of CLL were reviewed. For each included dog, a CBC, blood smear for microscopic reevaluation, and immunophenotyping data had to be available. Data on signalment, history, clinical findings, therapy, follow-up, as well as date and cause of death were retrieved.Results: Seventeen dogs had B-CLL (CD21+), 19 had T-CLL (CD3+ CD8+), and 7 had atypical CLL (3 CD3- CD8+, 2 CD3+ CD4- CD8-, 1 CD3+ CD4+ CD8+, and 1 CD3+ CD21+). Among the variables considered, only immunophenotype was associated with survival. Dogs with T-CLL had approximately 3-fold and 19-fold higher probability of surviving than dogs with B-CLL and atypical CLL, respectively. Old dogs with B-CLL survived significantly longer than did young dogs, and anemic dogs with T-CLL survived a significantly shorter time than dogs without anemia.Conclusions: Although preliminary, results suggested that immunophenotype is useful to predict survival in dogs with CLL. Young age and anemia are associated with shorter survival in dogs with B-CLL and T-CLL, respectively
Efeito do processamento e nível energético de dietas sobre o desempenho de frangos de corte.
Na nutrição animal, a forma física das dietas é fator importante associado ao desempenho produtivo e ao aproveitamento dos nutrientes (5). Dietas peletizadas e trituradas proporcianam benefícios como a melhora no consumo e conversão alimentar, diminuição da segregação dos ingredientes e desperdício, aumento da densidade e melhora na digestibilidade e palatabilidade geral da ração (4). Aliado a isso, óleos vegetais e gordura animal são ferramentas importantes na formulação de dietas, suprindo os altos requerimentos de energia necessários para o ótimo desempenho das aves (3). O objetivo do trabalho foi estudar a influência do processamento e do nível energético de dietas sobre o desempenho produtivo em frangos de corte até 21 dias
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