Physiological Changes in Chicken Embryos Inoculated with Drugs and Viruses Highlight the Need for More Standardization of this Animal Model.

Several studies have been developed using the Gallus gallus embryo as an experimental model to study the toxicity of drugs and infections. Studies that seek to standardize the evaluated parameters are needed to better understand and identify the viability of CEs as an experimental model. Therefore, we sought to verify whether macroscopic, histopathological, blood count, metabolites and/or enzymes changes and oxidative stress in CE of different ages are specific to the model. To achieve this goal, in ovo assays were performed by injecting a virus (Gammacoronavirus) and two drugs (filgrastim and dexamethasone) that cause known changes in adult animals. Although congestion and inflammatory infiltrate were visible in the case of viral infections, the white blood cell count and inflammation biomarkers did not change. Filgrastim (FG) testing did not increase granulocytes as we expected. On the other hand, CE weight and red blood cell count were lower with dexamethasone (DX), whereas white blood cell count and biomarkers varied depended on the stage of CE development. Our work reinforces the importance of standardization and correct use of the model so that the results of infection, toxicity and pharmacokinetics are reproducible.

Hematologic parameters of captive Bothrops atrox (Squamata: viperidae)

The breeding of venomous snakes in captivity for research purposes and mainly as a source of pharmaceutical products highlights the need to determine hematological parameters for monitoring and ensuring a healthy breeding populationThe complete blood count is used to help diagnose alterations such as anemia, inflammatory diseases, parasitemia, hematopoietic disorders, hemostatic and toxicological changes, as well as bacterial and viral inclusions. Thus, the objective of this study was to define reference parameters for complete blood count in Bothrops atrox snakes. Blood samples were collected from 20 specimens of B. atrox from the Pentapharm do Brasil commercial breeding facility for laboratory examination. Mean values and standard deviation were: hematocrit 33.6 ± 5.47%, hemoglobin 10.81 ± 2.07g/dL, total number of erythrocytes 0.59 ± 0.1 x 106/mm3, leukocytes 11387.5 ± 3279.2/mm3 and thrombocytes 28175 ± 6320/mm3. No significant difference was observed between males and females and heterophils were the predominant leukocyte cell type.