Browsing by Author "Ferreira, R."
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- Blood Transfusions in Dogs and Cats: Blood Typing, Cross MatchingPublication . Branquinho, T.; Ortiz, V.; Vala, Helena; Ferreira, R.; Santos, C.; Oliveira, A. L.The blood transfusion (administration of blood) is a resource of veterinary medicine with several indications. Point-of-care blood-typing methods, including both typing cards and rapid gel agglutination, are readily available. Following blood typing, cross matching is performed on one or more donor units of appropriate blood type. Cross matching reduces the risk of transfusion reactions but does not completely eliminate the risk of other types of transfusion reactions in veterinary patients. All transfusion reactions should be appropriately documented and investigated. It is, therefore, important to have in-depth technical knowledge about concepts and procedures involved in clinical blood transfusion, so that the entire procedure can be performed in the most appropriate way and with a high success rate.
- Effects of histamine on the development of MNU-induced mammary tumoursPublication . Faustino-Rocha AI, A. I.; Gama, A.; Oliveira, P. A.; Vala, Helena; Ferreira, R.; Ginja, M.Objective: Breast cancer is frequently diagnosed worldwide. Histamine acts as mediator in several cancers. Ketotifen is a mast cells stabilizer drug that inhibits their degranulation. This work aimed to evaluate the effects of histamine on the development of MNU-induced mammary tumors. Methods: Procedures followed the European Directive 2010/63/EU. Twenty animals were equally divided into two experimental groups: ketotifen and control. At seven weeks of age, all animals received an intraperitoneal injection of N-methyl-N-nitrosourea (MNU). Animals from ketotifen group received ketotifen in drinking water (1mg/Kg; 7days/week; for 18 weeks). At the sacrifice, mammary tumors were fixed and histologically evaluated. Results: During the protocol one ketotifen-treated animal died. At the end, eight animals from ketotifen group developed 19 mammary tumors (2.4 tumors per animal), while six animals from control group developed 21 mammary tumors (3.5 tumors per animal). Animals from control group developed one benign lesion and 20 non-invasive carcinoma; all lesions from ketotifen-treated animals were malignant, however they did not develop any comedo carcinoma that was the lesion of the highest grade of malignancy found in this work. Conclusion: Inhibition of histamine release by ketotifen seems to reduce the number and malignancy of MNU-induced mammary tumors.
- Expression of estrogen receptors-α and β in chemically-induced mammary tumoursPublication . Faustino-Rocha, A. I.; Gama, A.; Oliveira, P. A.; Alvarado, A.; Vala, Helena; Ferreira, R.; Ginja, M.Objective: Estrogen receptors (ERs)-α and β are important for stimulating the growth and differentiation of human mammary tumours, respectively. This work aimed to evaluate the expression of ERs-α and β in rat chemically-induced mammary tumours. Methods: Procedures followed the European legislation (2010/63/EU). Fifteen seven-week-old female Sprague-Dawley rats received an intraperitoneal injection of N-methyl-N-nitrosourea (MNU) (50mg/Kg). At sacrifice, mammary tumours were fixed and histologically evaluated. Sections were incubated with ER-α and β primary antibodies and the percentage of immunopositive cells was determined. Results: During the experimental protocol four animals died, all survived animals developed mammary tumours: 30 benign, 2 preneoplastic and 39 malignant lesions. All histological patterns expressed ERs-α and β. The mean expression of ER-α (55.14% ± 13.26) was lower than the expression of ER-β (70.06% ± 18.51) (p<0.05). The expression of both receptors was not statistically different among lesions, however it was higher in preneoplastic lesions, followed by malignant and benign ones (p>0.05). Conclusion: All MNU-induced mammary tumours in rats expressed ERs-α and β, being a good model of ER-positive human mammary tumours. Once the expression of ER-β was higher, tumours’ differentiation was stimulated and its proliferation was inhibited.
- 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.
- Transfusões sanguíneas em animais de companhia.Publication . Branquinho, T.; Ferreira, R.; Vala, Helena; Santos, C.; Esteves, F.; Cruz, R.; Nóbrega, C.; Mesquita, J.; Mega, A. C.; Oliveira, A. L.
- Walking against cancer: the impact of long-term exercise training on mammary tumorsPublication . Rocha, A. I. Faustino; Oliveira, P. A.; Gama, A.; Vala, Helena; Esteves, Fernando; Ferreira, R.; Ginja, M.Breast cancer is one of the most frequent cancers among women worldwide. The present work evaluated the effects of long-term exercise training on the development of chemically-induced mammary cancer. Materials and Methods: Procedures followed the European legislation and were approved by the Portuguese Ethics Committee (DGAV, approval nº008961). Thirty 7-week-old female Sprague-Dawley rats were intraperitoneally injected with the carcinogen N-methyl-N-nitrosourea (MNU) (50mg/Kg). After this, they were randomly divided into two experimental groups: sedentary (n=15) and exercised (n=15). Exercised animals were trained on a treadmill for 35 weeks. At the end of the study, the mammary tumors were collected, fixated in formalin and histologically evaluated. The expression of estrogen receptor (ER)α was assessed by immunohistochemistry. Results: An incidence of 100% was observed. A total of 51 mammary tumors was developed: 28 in sedentary group and 23 in exercised one (p>0.05). At histopathological analysis, it was observed that each mammary tumor exhibited more than one histological pattern. A total of 121 mammary lesions was counted: 71 in sedentary group and 50 in exercised group (p=0.056). The number of malignant lesions was higher in sedentary group when compared with the exercised one (39 versus 21) (p=0.020). All mammary lesions exhibited nuclear immunostaining for ERα; the immunoexpression was higher in exercised group when compared with the sedentary one (p<0.05). Conclusions: Long-term exercise training reduced the number and malignancy of mammary tumors. Additionally, it increased the ERα immunoexpression that is an indicator of tumor differentiation and better response to hormone therapy.