Andre Silva Carissimi

Hematological and biochemical profiles of rats (Rattus norvegicus) kept under microenvironmental ventilation system

Em estudos anteriores, demonstrou-se que ratos mantidos em sistema de Ventilacao Microambiental (VMA) apresentaram parâmetros de produtividade e padrao sanitario melhores do que aqueles mantidos em sistema de Ventilacao Geral Diluidora (VGD). Outra etapa dos experimentos foi determinar os parâmetros fisiologicos destes animais. O presente estudo foi realizado para avaliar os perfis hematologico e bioquimico de ratos mantidos sob o sistema de VMA. Para tanto, foram realizados dois experimentos diferentes, com ratos mantidos em VMA, quais sejam: Experimento 1 (E1), no qual foi avaliado o desempenho reprodutivo de machos e femeas, sob duas faixas de velocidade de ar (FV1 - de 0,03 a 0,26 m/s, e FV2 - de 0,27 a 0,80 m/s); Experimento 2 (E2), no qual foram avaliados diferentes intervalos de troca de cama (3, 5, 7 e 9 dias), para ratos machos mantidos a uma velocidade de ar constante de 0,5 m/s. Os valores do hemograma e de parâmetros bioquimicos destes animais foram comparados com os valores encontrados em ratos mantidos sob VGD. Os resultados obtidos demonstraram diferencas estatisticas em alguns dos parâmetros observados, tanto entre os sistemas VGD e VMA, como entre os diferentes grupos de VMA. Contudo, os valores encontrados em todos os parâmetros avaliados encontram-se dentro de faixas de variacao normal para a especie estudada, como e descrito na literatura. Isto indica que o emprego do sistema de VMA nao induz alteracoes relevantes nos parâmetros fisiologicos estudados.

Achados patológicos e imuno-histoquímicos em cães infectados naturalmente pelo vírus da cinomose canina

Canine distemper is a viral disease that affects mainly respiratory, gastrointestinal and nervous system. The present study analyzes pathologic and immunohistochemical findings in 54 dogs with canine distemper of a total of 760 canine necropsies performed from July 2006 to October 2007. The gross lesions were characterized by mucopurulent oculonasal discharge, hyperkeratosis of footpads, red and not collapsed lungs, thymic atrophy, watery intestinal content, hyperemia and enlarged Peyers patches. The histological findings were characterized by interstitial pneumonia, lymphoid depletion, white matter demyelization, perivascular cuffs and intracytoplasmatic and intranuclear inclusion bodies located in epithelial cells of gastric mucosa, urinary bladder, bronchial, renal pelvis, footpads, eyelid, skin of the ear, tonsil, central nervous system and mononuclear cells in lymph nodes, spleen, and tonsils. Viral antigen was detected by an immunohistochemical procedure using a mouse monoclonal anti-canine distemper antibody. The footpads were the more constantly (67.4% of the cases) immunolabeled tissue, followed by stomach with 62.7%. Immunohistochemistry was demonstrated to be a useful tool for the study of viral antigen distribution in distemper affected dogs as well as it indicated which is the best tissue to be examined in order to confirm a suspected case of canine.

Effects of an individually ventilated cage system on the airway integrity of rats (Rattus norvegicus) in a laboratory in Brazil

The ventilation method used in the management of laboratory rats is important in maintaining their health. Rats kept under general diluting ventilation (GDV) are exposed to high levels of pollutants present in the environment (dust, airborne bacteria, etc.) or those pollutants produced by animal metabolism and excretion inside the boxes (e.g. ammonia and carbon dioxide). These pollutants may contribute to respiratory pathologies. An alternative experimental ventilation system for laboratory animal housing using intracage ventilation technology (individually ventilated cage system, IVC) was developed. In this system, ammonia levels decreased and rats exhibited better reproductive performance and a lower incidence of pneumonia than rats maintained under GDV. Using two different levels of air speed (0.03–0.26 m/s: IVC1; 0.27–0.80 m/s: IVC2), the effects of IVC were compared with GDV (control) in Wistar rats in terms of respiratory mucus properties, on the nasal epithelium (as measured by quantitative morphometry) and on the lungs (as determined by the cellular composition obtained by bronchoalveolar lavage). Mucus of the respiratory system was evaluated using the following techniques: rheology (viscoelasticity) by microrheometer, in vitro mucociliary transportability (frog palate) and contact angle (an indicator of adhesivity). Also, membrane transepithelial potential difference was measured as a biomarker of airway integrity. After bedding was changed, ammonia concentrations inside the cages on day 3 were significantly higher for GDV than for IVC1 and IVC2. The potential-difference values for IVC1, IVC2 and GDV in the epiglottis and in the trachea also showed differences. Although some significant differences were observed across the three groups in counts of some cell types, the intragroup results were highly variable among individuals and inconsistent between sexes. No significant differences in the other parameters were found across groups. These results establish that rats maintained under GDV in relatively unregulated conditions are exposed to factors that can lead to deleterious effects on the ciliated epithelium of the airways, and that these effects can be prevented by the use of IVC.

Parâmetros hematológicos do roedor fossorial Ctenomys lami (Rodentia, Ctenomidae) no estado do Rio Grande do Sul

The hematological profile was determined in three populations of Ctenomys lami that inhabits three different areas nominated as A and B, affected by cattle production, and C, without human impact, all of them in southern Brazil, under the same geologic formation. Sixty two individuals were collected. The packed cell volume (PCV) values, hemoglobin (Hb) and red blood cell (RBC) count presents statistic significant differences between males and females. PCV and Hb values were lower in comparison with other subterranean rodents, which could be related to the food searching behavior or soil characteristic of the species. Significant statistic differences were found to for Hb, mean corpuscular hemoglobin concentration (MCHC) and lymphocytes between animals belonging to A and C areas. The PCV values were higher for animals from areas A and B, with significance only between A and C. Some of these alterations may suggest a modification on stress levels of the animals inhabiting areas A and B with anthropic alterations, or maybe just an inherited characteristic. Significant statistic differences were found either in mean corpuscular volume (MCV) between A and C areas, and platelets between A and B areas. No Kurloff cells were observed in the blood smear from analyzed individuals. The hematological values founded for Ctenomys lami are an important information for this species, which can be used for future research and management.

Teste de introdução transdiafragmática de drenos torácicos em cadáveres de cães

The thoracic drainage is an important technique for the thoracic traumatized patient. Its main objective is to remove fluids or gazes from the pleural cavity through a thoracic tube. Besides, it induces fibrine production, because its reaction of foreign body. Fibrine has a crucial effect on closure of small lung ruptures, avoiding air leaking. Therefore, the thoracic drainage should be done very carefully in patients with rib fractures, due to its possibility of lung or heart lesion. The aim of this study was to test a new way of thoracic drain introduction, the transdiaphragmatic thoracic drainage, using six canine corpses. Within 36 tries, only two were successfully, which disapproves the use of this technique in Veterinary Medicine.