Browsing by Author "Cruz, Rita"
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- A 2-Year Longitudinal Seroepidemiological Evaluation of Toxoplasma gondii Antibodies in a Cohort of Autochthonous Sheep from Central PortugalPublication . Almeida, Daniela; Quirino, João; Barradas, Patrícia Ferreira; da Silva, Priscilla Gomes; Pereira, Maria; Cruz, Rita; Santos, Carla; Mega, Cristina; Esteves, Fernando; Nóbrega, Carmen; Vala, Helena; Gärtner, Fátima; Amorim, Irina; Mesquita, João R.Background: Toxoplasma gondii is an important zoonosis and one of the major causes of abortion in sheep worldwide. (2) Methods: We performed a 2-year longitudinal serological antiT. gondii IgG screening on a cohort of a spatially confined population of a Portuguese autochthonous sheep breed in central Portugal. (3) Results: From the screening of the 2015 and 2016 sera, an increase of seroprevalence was observed (57.7% (95% CI: 49.9–65.3%) versus 69.1% (95% CI: 61.5–75.9), from 2015 and 2016, respectively) (p = 0.031). (4) Conclusions The present study is the first to provide prospective data on the anti-T. gondii serological status of a sheep cohort in Portugal, showing an increase in the occurrence of T. gondii. There is a need to provide a clearer understanding of T. gondii epidemiology in Portugal, ideally by implementing monitoring programs on sentinel herds, not only due to the high impact of T. gondii on animal health but also for it being a zoonosis.
- ABC series on diagnostic parasitology part 1: the Willis methodPublication . Mesquita, João R.; Esteves, Fernando; Santos, Carla; Mega, Ana Cristina; Coelho, Catarina; Cruz, Rita; Vala, Helena; Nóbrega, CármenDiagnosis of parasitic infections in animals is an interesting task that can be developed by veterinary nurses. To perform direct identification of parasites, particularly ova present in faeces, it is possible to use faecal smears, flotation and sedimentation tests. Faecal flotation is fast and inexpensive, and can be quickly implemented as a measure for infection control. Herewith we describe the Willis method, one of the most used flotation methods.
- 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.
- ABC series on diagnostic parasitology part 3: the Baermann techniquePublication . Mesquita, João R.; Mega, Ana Cristina; Coelho, Catarina; Cruz, Rita; Vala, Helena; Esteves, Fernando; Santos, Carla; Nóbrega, CármenDiagnosis of parasitic larval forms is typically associated with complex, costly methods. As such, simple, low-cost diagnostic tools for larvae identification are of the utmost importance in diagnostic parasitology in the veterinary clinic. Herewith we describe the Baermann technique, one of the most used larvae identification methods
- An Antibody-Based Survey of Toxoplasma gondii and Neospora caninum Infection in Client-Owned Cats from PortugalPublication . Pereira, Maria Aires; Nóbrega, Carmen; Mateus, Teresa Letra; Almeida, Daniela Gomes de; Oliveira, Andreia; Coelho, Catarina; Cruz, Rita; Oliveira, Paula; Faustino-Rocha, Ana; Pires, Maria J.; Mesquita, João R.; Vala, HelenaToxoplasma gondii and Neospora caninum are obligate intracellular protozoan parasites infecting a wide range of hosts worldwide. However, information on the epidemiology of toxoplasmosis and neosporosis in cats from Portugal is limited. Thus, this study aims to evaluate anti-T. gondii and anti-N. caninum seroprevalence in client-owned cats from Portugal and to identify risk factors using a panel of well-characterized sera. A total of 183 domestic cats were sampled and screened for antibodies against T. gondii and N. caninum using commercial ELISA assays, and their owners answered an online questionnaire designed to obtain background information. The overall anti-T. gondii and anti-N. caninum seroprevalences were 13.1% (CI: 8.97–18.77) and 3.8% (CI: 1.87–7.68), respectively. Univariate analysis revealed that living strictly indoors was a significant protection factor (cOR: 0.053; CI: 0.005–0.627), and the presence of a chronic disease a significant risk factor (cOR: 3.106; CI: 1.062–9.082) to T. gondii seroprevalence. When performing multivariate analysis, only chronic disease (aOR: 57.527; CI: 1.7–1976.7) and seropositivity to N. caninum (aOR: 7.929; CI:0.8–82.9) were found to be a significant risk factor to anti-T. gondii antibodies. To the best of our knowledge, this is the first report of N. caninum seropositivity in cats from Portugal.
- Bioética e experimentação animalPublication . Nóbrega, Carmen; Oliveira, P. A.; Mesquita, João; Santos, C.; Arantes, R.; Themudo, D.; Esteves, Fernando; Cruz, Rita; Mega, Cristina; Vala, Helena- Introdução: O contributo da experimentação animal para a ciência é inegável. Dificilmente os meios médicos e profiláticos teriam atingido o presente estado de evolução sem a sua contribuição. O objectivo deste trabalho é a apresentação do conceito de experimentação animal, como uma prática válida e eticamente correta, desde que devidamente planeada e executada. - Estado da Arte: O recurso a animais vivos em investigação, tem desempenhado um papel importante no avanço científico, particularmente na área da saúde. Este facto dá origem a um dilema ético: se por um lado a maior parte dos animais utilizados são seres sencientes, por outro lado, a investigação pode ser de vital importância para a prevenção, cura ou melhoria significativa de doenças em humanos. Não sendo um tema consensual, é geralmente alvo de intenso debate. Opositores a qualquer tipo de investigação com recurso a animais, afirmam que a experimentação animal é cruel e desnecessária porque os animais não existem para serem usados segundo o nosso critério. No entanto, a generalidade da sociedade aceita que os animais possam ser utilizados em experimentação mas não a qualquer preço. Nos últimos anos, têm ocorrido progressos na criação de alternativas à experimentação animal, nomeadamente as culturas celulares, de tecidos e órgãos, fazendo com que, em certas situações, os animais possam já ser substituídos por alternativas eticamente mais aceitáveis, não podem, contudo, ser inteiramente eliminados da investigação. - Novas perspetivas/diretrizes Uma investigação ética e cientificamente válida com aplicabilidade na saúde humana, exige a seleção de modelos adequados para a acção estudada e o cumprimento do princípio dos 3Rs: Replace; Reduce; Refine. A estes, deve juntar-se ainda o R da responsabilidade, que deve prevalecer desde o delineamento da experimentação e acompanhar o decurso dos trabalhos experimentais. - Implicações teóricas e práticas Pesando os prós e contras, os benefícios da experimentação animal pesam mais no que se refere ao impacto na melhoria da saúde humana. Se esta prática fosse abandonada, certamente existiriam severas consequências a nível da investigação e da saúde pública.
- Bulk-Tank Milk Longitudinal Serosurvey Reveals Decreasing Schmallenberg Virus Circulation in a Confined Population of Portuguese SheepPublication . Esteves, Fernando; Cruz, Rita; Nóbrega, Carmen; Santos, Carla; Ferreira, Ana S.; Petrovic, Tamas; Cardoso, Luís; Vala, Helena; Nascimento, Maria S.J.; Mesquita, João R.Introduction: In 2011, Schmallenberg virus (SBV) was first detected in dairy cattle herds in The Netherlands and Germany having since then spread across Europe. Today studies are starting to show a decrease in new SBV infections, a circumstance that raises alerts for possible re-emergence if ideal conditions for vector development occur. To assess the potential decrease in SBV circulation, we performed a 2-year longitudinal serological investigation for SBV infection at the herd level by using bulk-tank milk of a specific sheep breed from central Portugal. Materials and Methods: Bulk-tank milk samples from 68 flocks were collected in both 2015 and 2016, and lactosera were tested for IgG anti-SBV by EIA. Results and Discussion: Results show that in 2015, 92.6% (95% confidence interval [CI]: 83.9–96.8) of the bulk-tank milk samples were positive, whereas in 2016 only 77.9% (95% CI: 66.7–86.1 of the samples from the same flocks were positive. Differences in the 2015/2016 seroprevalences showed to be statistically significant (p = 0.027). This significant decrease at the herd level seems to be in agreement with reported data from other European countries and raise alerts, since increasingly favorable conditions (higher number of susceptible animals) are now present, potentially favoring SBV epidemics if improved conditions for midge replication occur in the future.
- Carcinogénese Experimental da Bexiga em MurganhosPublication . Nóbrega, Carmen; Vala, Helena; Mesquita, João; Santos, C.; Themudo, D.; Oliveira, P. A.; Esteves, Fernando; Cruz, Rita; Mega, Cristina; Arantes, R.; PA., OliveiraIntrodução: A oncologia experimental é uma ciência em crescente evolução, que tem permitido estudar os mecanismos biopatológicos associados ao crescimento, invasão e metastização dos tumores, bem como a investigação de novas moléculas, eventuais novos agentes profilácticos, terapêuticos ou paliativos. O objetivo deste trabalho consiste na apresentação de um projeto de investigação em que se promoveu a carcinogénese experimental da bexiga em murganhos, para a posterior realização testes farmacológicos. Estado da Arte: O cancro da bexiga é o 7º tumor mais comum no homem e o 2º do trato urogenital, encontrando-se descrita predisposição sexual para o sexo masculino (4:1). Histologicamente, a maioria dos tumores de bexiga são superficiais, sendo o carcinoma invasivo menos frequente. No entanto, este último assume grande importância clínica, dado o difícil tratamento, a elevada possibilidade de metastização e o prognóstico reservado. São vários os modelos animais que podem ser utilizados no estudo dos tumores bexiga. O modelo animal para o carcinoma invasivo da bexiga consiste na indução pela administração na água de bebida da N-butil-N-(4-hidroxibutil)nitrosamina (BBN) a murganhos. Métodos: Foram utilizados murganhos macho da estirpe ICR, divididos em dois grupos: grupo controlo e experimental, que foi submetido à acção da BBN (0,05%), durante 12 semanas. Os animais foram distribuídos por gaiolas adequadas em tamanho, com água à disposição, alimentação ad libitum e enriquecimento ambiental. Todos os animais foram sacrificados no final do trabalho experimental e submetidos a necrópsia. Resultados: A incidência de tumores induzidos pela BBN, em roedores, atingiu os 100%. Foram também observadas outras lesões, nomeadamente metaplasia epidermoide, hiperplasia simples, hiperplasia nodular, displasia e hiperplasia papilar. Conclusões: As lesões quimicamente induzidas em roedores pela BBN assemelharam-se grandemente às observadas em humanos, facto que permitiu caraterizar este como um bom modelo para o estudo das neoplasias da bexiga.
- A case of giant cell tumourPublication . Vala, Helena; Andrade, Luís; Nóbrega, Carmen; Santos, Carla; Cruz, Rita; Mega, Cristina; Esteves, Fernando; Gomes, A.; Mesquita, JoãoMalignant fibrous histiocytoma refers to a group of soft tissue tumours that represents a diagnostic challenge which must be based in the predominant cellular type present. The authors describe an unusual case of tumour in which the presence of giant cells was the distinctive feature. A 7 year old Cocker Spaniel male dog was presented with a subcutaneous nodule in the labial commissure, measuring 1.5 cm in diameter. Sample was fixed in 10 % buffered formalin solution, embedded in paraffin wax and 3 μm thick sections were stained for routine histopathological diagnosis with Haematoxylin and Eosin. A standard Streptavidin-Biotin Complex technique for immunohistochemical evaluation was also performed. Macroscopic examination revealed dark brown, slightly lobed tissues, alternating with whitish tissues, both with moderate consistency on the cut surface. Microscopic examination revealed ulceration and necrosis of the epidermis, under which a high cellular population of undifferentiated cells was observed. These cells population exhibited oval, normo or eucromatic nucleus, with notorious nucleolus and moderate cytoplasm that, resembled fusiform fenotype, intermixed with blood vessels and multinucleated giant cells, as well as intense immunoreactivity for vimentin. The authors suggest the diagnosis of malignant fibrous histiocytoma of giant cell subtype, based on the multinucleated giant cells predominance and submit it to the discussion, particularly for histological grade assessment and prognosis, since there is still some discrepancy in the literature.
- A case of vascular tumour mimicking lymphangiomaPublication . Vala, Helena; Mega, Cristina; Santos, C.; Cruz, Rita; Santos, M.; Esteves, Fernando; Nóbrega, Carmen; Mesquita, JoãoIntroduction Sarcomas, particularly vascular tumours, can mimic other neoplastic conditions or even inflammatory diseases. Objectives The authors describe an unusual case of vascular tumour, histologically overlapping with benign lymphangioma and liposarcoma. Medical History A 8 year old Shar Pei male dog was presented with a subcutaneous nodule in the chest, measuring 3x2 cm. Material and Methods The sample was fixed in 10 % buffered formalin solution and processed for routine histopathological diagnosis with Haematoxylin and Eosin. A standard Streptavidin-Biotin Complex technique for immunohistochemical evaluation was also performed, using a Polyclonal Rabbit Anti-Human Von Willebrand Factor. Results Macroscopic examination revealed a well circumscribed nodule with homogeneous and brownish appearance and moderate consistency on a cut surface. Microscopic examination revealed clefts and variably-sized vascular spaces, lined by a single layer of spindle cells, with round-to-oval nuclei, small or indistinct nucleoli, small amount of eosinophilic cytoplasm, with endothelial appearance – areas like hemangiosarcoma, interspersed with areas, where these cells appeared to grow directly on thick bundles of dermal collagen, occasionally with erythrocytes – areas like lymphangioma. The stroma was also interspersed with vacuolar cells – areas like liposarcoma. No mitotic figures were seen, however, the presence of very rich cellular areas, with more prominent cells revealing pleomorphism and anisocariosis, were more favour to malignancy Conclusion The authors suggested the diagnosis of vascular neoplasia with unusual features, based on the histopathological diagnosis and immunohistochemistry results, and submit to the discussion, especially for assessment of histological grade and prognosis.