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- ABC series on diagnostic parasitology part 2: the McMaster methodPublication . Nóbrega, Cármen; Santos, Carla; Mega, Ana Cristina; Coelho, Catarina; Cruz, Rita; Vala, Helena; Esteves, Fernando; Mesquita, João R.Classical coprological methods allow for inexpensive, quick and reliable detection of parasitic elements. However, the detection of these parasitic elements may be insufficient and quantification of the parasitic burden may be required. As such, faecal egg counts can play a crucial role in providing these extra data. Herewith we describe the McMaster method, one of the most used faecal egg count methods described.
- E-Cadherin and β-Catenin Expression during Urothelial Carcinogenesis Induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in MicePublication . Vasconcelos-Nóbrega, C.; Costa, C.; Vala, Helena; Colaço, A.; Santos, L.; Lopes, C.; Oliveira, PABACKGROUND: E-cadherin and β-catenin are adhesion molecules that promote integrity and stability of the urothelium. A decrease in theirexpression is associated with more aggressive tumour phenotypes with the ability to invade and metastasize. MATERIAL AND METHODS: 45 ICR male mice were used, of which 25 received N-butyl-N-(4-hydroxybutyl)nitrosamine (0.05%) in drinking water for a period of 12 weeks. Immunohistochemical expression was evaluated in all urinary bladder preparations for E-cadherin and for β-catenin. RESULTS: Preneoplastic lesions showed staining patterns similar to normal urothelium. In simple and nodular hyperplasia, membrane staining was dominant (66.7-78.6 and 50-100%, respectively). In dysplasia a cytoplasmic pattern was prevalent (86.7-100%). Neoplastic lesions exhibit an abnormal staining pattern (100%) with heterogeneous staining (cytoplasmic, nuclear and membrane staining). A strong correlation was observed between both adhesion molecule staining patterns (r = 0.83; p = 0.039). CONCLUSIONS: In mice, as in humans, E-cadherin and β-catenin are valuable tools to investigate cellular adhesion status of urothelium and can be considered as indicators of tumour aggressiveness and evolution.
- Histological assessment of small bowel hypoperfusion lesions in the pigPublication . Oliveira, A. L.; Ferreira, D.; Vala, HelenaBackground Authors propose the use of a quantitative morphological assessment for helping in studies concerning intestinal hypoperfusion. The method was applied to the small intestine mucosa stained with the standard hematoxylin and eosin, from pigs that underwent severe hypotension due to acute hemorrhage.,. Methods Six Large White pigs underwent total intravenous anesthesia with propofol and remifentanil. 25 ml/kg of arterial blood were passively removed from the femoral artery over 20 minutes. Volume was replaced using Ringer Lactate in Group 1 and Hydroxyethyl starch 130/0.4 in Group 2, with a delay of 20 minutes after the bleeding. One hour after the volume replacement, pigs were euthanized and the small intestine samples were taken for histopathological examination. Parameters were classified using two specific scales (Chiu, 1970; Çetin, 1995; Kaplan, 2007). Mucosal loss (ML) percentage and crypt:interstitium ratio were obtained (Faleiros, 2001). Results Inflammatory infiltrate was present in all animals, varying from grade 2 to grade 3. Hydropic cellular degeneration and epithelial detachment were more pronounced in duodenum and more noticeable in Group 1. In Group 1, ML percentage was 2.18±0.46 % in duodenum, 0.62±1,07% in jejunum and 0.45±0.77% in ileum. In Group 2 ML percentage was 0.75±1.30 in duodenum and 0±0% in the other intestinal segments. In the whole small intestine, was 1.08±0.78% in Group 1 and 0.25±0.35% in Group 2. Crypt:interstitium ratio did not presented significant differences between the groups. Conclusions The quantitative morphological assessment may be useful in quantifying the degree of mucosal lost in small intestine stained with hematoxylin and eosin, from pigs submitted to acute severe bleeding.
- Cattle neoplasias on São Miguel Island - AzoresPublication . Pinto, C.; Medeiros, F.; Alves, A.; Pires, M.; Rodrigues, P.; Seixas, F.; Vala, Helena; Durão, F.; Peleteiro, C.; Peña, L.; Sánchez, B
- Princípios Básicos de Hematologia. Esfregaço sanguíneoPublication . Vala, HelenaO sangue é um tecido vivo fluído que circula num dos sistemas vasculares do corpo, o qual apresenta uma “bomba” central, o coração – órgão muscular que bombeia o sangue para as circulações pulmonar e geral. Quando o colocamos no interior de um tubo de ensaio o sangue separa-se em duas camadas. A camada superior líquida, designada por plasma, representa cerca de 55% do volume de sangue total e contém uma variedade de substâncias orgânicas e inorgânicas dissolvidas ou suspensas em água. A camada inferior é constituída por células vermelhas do sangue (eritrócitos), glóbulos brancos (leucócitos) e plaquetas (trombócitos) que, coletivamente, constituem os elementos figurados do sangue e representam 45% do volume de sangue total. O esfregaço sanguíneo constitui o método mais usual para observar o sangue e seus constituintes, pesquisar hemoparasitas e determinar a fórmula leucocitária, variável com a espécie, sendo fundamental que o Enfermeiro Veterinário domine as técnicas para a sua execução e reconheça as diferentes células sanguíneas. Neste trabalho será apresentada uma revisão dos órgãos hematopoiéticos (onde se originam os eritrócitos), órgãos linfóides (onde se originam ou diferenciam os leucócitos), bem como das funções do sangue e seus componentes.
- Transfusion Medicine in Dogs and Cats: Products, collection and administrationPublication . Branquinho, T.; Ortiz, V.; Vala, Helena; Ferreira, R.; Santos, C.; Oliveira, A. L.Many veterinary hospitals have permanent canine and/or feline blood donors to cover their transfusion requirements and some have their own blood bank. Hospitals must ensure there is appropriate donor selection and screening, as there are inherent risks of transmission of infectious agents and of causing adverse reactions. All donors should be fully vaccinated and receive regular veterinary preventative health care. A full physical examination should be performed by a veterinary surgeon prior to each donation, and should be unremarkable. Donors should also be screened for infectious diseases. Blood collection and component preparation can be labour intensive and time consuming. It is of great importance to know the properties of the different blood products available in transfusion medicine, as well as how they might be used to achieve the best results in clinical practice. Veterinary nurses must know how to administer blood and blood products safely to their patients. Blood products are prepared from donor animals and represent a very limited resource, not available in all situations. Through a combination of rigorous donor screening, individualized blood product selection, and careful monitoring, veterinary nurses can minimize the risks and enhance the benefits of transfusion.
- Rabbit haemorrhagic disease (RHD) – a new variant?Publication . Vala, Helena; Coelho, C.; Nóbrega, C.; Mesquita, JR.; Oliveira, J.Background: Rabbit haemorrhagic disease (RHD) is an acute fatal disease of domestic and wild European rabbits caused by a RNA virus (genus Lagovirus, family Caliciviridae). Prior to 1984, healthy rabbits in European regions had RHDV-specific antibodies and their infection with benign rabbit caliciviruses conferred them a low degree of cross-protective immunity against RHD, determining less severe clinical courses. Vaccination allowed to control the disease in the rabbit industry, but RHD still threatens non-vaccinated wild populations. A new variant of this disease is being described since 2010 in Iberian Peninsula. It affects mainly young rabbits that exhibit haemorrhages in heart, trachea, thymus, lungs, liver, kidneys and gut, as well as DIC, jaundice, splenomegaly and catarrhal enteritis. Objectives: To describe a case of high mortality rate on a rabbitry, mostly in young rabbits, with typical lesions of RHD. Methods: Samples from domestic vaccinated and non vaccinated rabbits which died suddenly were taken and fixed in 10% neutral-buffered formalin for 48 hours and embedded in paraffin. 3µm sections were stained for routine histopathological diagnosis (H&E) and examined by light microscopy. Results: Main macroscopic lesions observed: opisthotonos, oedema and pulmonary congestion, severe jaundice, splenomegaly, gastric punctiform ulcers, bilateral renal congestion and thymic petechiae, Conclusions: Macroscopic lesions in infected young’s, consistent with RHD infection usually observed only in adult rabbits, and the presence of lesions mostly associated to the new variant of RHD (DIC, jaundice, splenomegaly, catarrhal enteritis), led us to consider the presence of the new variant of RHD in Portugal, although further studies are needed.
- New therapeutic approaches on chronic kidney diseasePublication . Nogueira, A.; Vala, Helena; Nóbrega, Carmen; Pires, C. A.; Colaço, B.; Oliveira, P. A.; Pires, M. J.Introduction: chronic kidney disease is a serious public health problem that affects millions of patients worldwide. So, the main research goals in the CKD patients are the research of new therapeutic approaches capable of slowing down the progression to end-stage renal disease. Objective: the aim of this work, was to evaluate the effects of chronic administration of chaetomellic acid A (CAA), which selectively blocks H-Ras farnesylation, on kidney chronic lesions in 5/6 nephrectomized Wistar rats, an animal model of chronic renal disease. Material and methods: sixty male Wistar rats (Rattus norvergicus) were housed under controlled conditions. After seven weeks of acclimatization, rats (weighing 359 to 402 g) were sham-operated (SO) or submitted to 5/6 nephrectomy (RMR). One week after surgery surviving animals (n=53) were distributed into four groups: SO: SO rats receiving no treatment (n=13); SO+CAA: SO rats receiving CAA treatment (n=13); RMR: RMR rats receiving no treatment (n=14); RMR+CAA: RMR rats receiving CAA treatment (n=13). CAA was intraperitoneally administered (0.23 µg/Kg) three times a week for six months. Six months after the surgical procedure, in the left kidney of each animal was evaluated the mean cortical and medullary echogenicity by two-dimensional ultrasonography. Then, the kidneys were removed, fixed in 10% neutral-buffered formalin and processed for routine histopathological diagnosis and chronic lesions were evaluated, by Hematoxylin-Eosin, reticulin and Masson trichrome methods, for severity. All experimental procedures followed the European (European Directive 2010/63/EU) and National (Decree-Law 113/2013) legislation on the protection of the animals used for scientific purposes. Results: the kidneys of the RMR animals treated with CAA showed a significantly decrease in the medullary echogenicity (p<0.05) compared with the RMR rats that received no treatment. Glomerulosclerosis and arteriolosclerosis scores were significantly lower (p<0.001) in the RMR+CAA group when compared with the RMR group. There were no significant differences in interstitial fibrosis, interstitial inflammation and tubular dilatation scores between the RMR+CAA and RMR groups.Conclusion: this data suggests that pharmacological inhibition of H-Ras proteins activation may be a future strategy in the prevention of end-stage renal disease.
- Feline Calicivirus: unveiling data on viral inactivationPublication . Lemos, M.; Nóbrega, C.; Vala, Helena; Mesquita, J. R.Feline Calicivirus (FCV) is an important and widespread virus of the feline population. As a member of the Caliciviridae family, FCV mutates readily in nature, and this has resulted in the recent emergence of a highly virulent haemorrhagic systemic strain. Despite the increased concern about this feline pathogen, little is still known on potential FCV virucidal compounds. On the other hand several experiments on the inactivation behaviour of various surface disinfectants have used FCV as a surrogate to monitor norovirus survival in order to minimize their impact on public health. This has led to a considerable number of studies generating a huge amount of data on FCV inactivation. These findings are presented here and may be useful to veterinary nurses who can improve their practice by minimizing FCV transmission.
- he Zoonotic Event of Leishmaniasis in Portugal: a Public Health Concern.Publication . Gouveia, A.; Santos, C; Vala, Helena; Esteves, F.; Oliveira, A. L.; Cruz, R.; Mega, A. C.; Nóbrega, C.; Mesquita, J. R.