Browsing by Author "Pinto, C."
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- 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
- Estudio inmunohistoquimico de diferenciación de los carcinomas de células escamosas bovinosPublication . Vala, Helena; Fondevila, D.; Carvalho, T.; Pinto, C.; Peleteiro, C.; Pinho, M.; Ferrer, L.En el ganado bovino son frecuentes los carcinomas de células escamosas localizados en párpados y tercer párpado. En Portugal, este tumor se diagnostica con frecuencia en bovinos de las Azores, representa un 21% del total de neoplasias diagnosticadas en esta especie, la segunda después de los tumores de la vejiga de la orina. El objetivo de este trabajo ha sido conocer el origen y grado de diferenciación de estas neoplasias utilizando anticuerpos contra queratinas expresadas en keratinocitos basales y suprabasales, y anticuerpos considerados marcadores de diferenciación terminal como la involucrina y profilagrina.
- Immunohistochemical studies of epidermal cell proliferation and p53 mutation in Bovine Ocular Squamous Cell CarcinomaPublication . Carvalho, T.; Vala, Helena; Pinto, C.; Pinho, M.; Peleteiro, M. C.Bovine Ocular Squamous Cell Carcinoma (OSCC) is the second most common cause of rejection due to neoplasia in slaughterhouses on S. Miguel Island, Azores and accounts for significant economic losses. In order to obtain better insight into the genesis and neoplastic transformation process of bovine OSCC, abnormal protein expression and proliferation index were assessed by the immunohistochemical evaluation of p53 and Ki67, respectively. OSCC samples were collected from fifteen bovine, and were classified histologically according to the degree of differentiation in three categories: poorly, moderately and well differentiated. Immunohistochemistry using polyclonal anti-human p53 antibody and polyclonal anti-human Ki67 antibody was performed. Ten out of fifteen tumours tested were immunoreactive for p53. Twelve tumours demonstrated Ki67 expression. As in human squamous cell carcinoma, p53 overexpression is frequent in bovine OSCC, providing support for a possible role of the protein in the pathogenesis of this neoplasia. No correlation between the percentage of p53 stained nuclei and the degree of differentiation was observed, although different patterns of staining were seen according to the degree of keratinization of the tumour cells. With the exception of moderately differentiated OSCC group, Ki67 index showed significant correlation with the histological pattern, increased proliferation being found in poorly differentiated OSCC (P=0.013).
- Immunohistochemical studies of proliferation cell markers and DNA mutation in bovine ocular squamous cell carcinomaPublication . Carvalho, T.; Vala, Helena; Fondevila, D.; Pinto, C.; Peleteiro, C.; Pinho, M.; Ferrer, L.The purpose of the present study was to immunocharacterize Bovine Ocular Squamous Cell Carcinoma neoplastic cells, in terms of proliferation index and DNA damage, using two human primary antibodies anti- Ki67 antigen of the cell cycle and anti- p53. Ki67 is a nuclear antigen expressed in dividing cells during late G1, G2, S-phase and M-phase that disapears rapidly after mitosis. p53 is a tumor supressor protein that plays a key role in the control of the DNA damage acting as a supressor of tumour cell proliferation, enhancing genetic stability. Mutation of the gene that codes for p53 provides an extended intracellular half-life of the protein and greater stability, therefore increasing its expression. Tumours for this study were obtained at the slautherhouse, in Ponta Delgada, Azores. A total of thirty samples were colected from eighteen bovine. Immunohistochemical analysis was performed in parafin embeded sections of formalin fixed material, using the Avidin-Biotin-Peroxidase method (ABC). Primary antibodies used were anti-human p53 (NCL – p53 CM-1, NOVOCASTRA, UK) and anti-human Ki67 (NCL – Ki67p, NOVOCASTRA, UK), both policlonal. Positivity for both Ki67 and p53 was evaluated quantitatively and semi-quantitatively, respectively
- Immunohistochemistry of epidermal differentiation markers in bovine ocular squamous cell carcinoma and distribution of cytokeratinsPublication . Vala, Helena; Fondevila, D.; Carvalho, T.; Pinto, C.; Peleteiro, C.; Pinho, M.; Ferrer, L.The aim of this study was to evaluate the possibility of using some antibodies as diagnostic instruments, in Bovine Ocular Squamous Cell Carcinoma (BOSCC) and establishing the relationship between immunohistochemical results and the degree of differentiation. Thirty two samples from nineteen bovine ocular tumours were collected at the Matadouro Frigorífico e Industrial of Ponta Delgada, S. Miguel Island, Azores. Material was fixed in 10% formalin, embedded in paraffin and stained for routine histopathological diagnosis for tumour classification. Diagnosis of BOSCC was confirmed in all samples. Nine carcinomas were well differentiated, five moderately differentiated and five non-differentiated. Immunohistochemical indirect technique Avidin-Biotin-Peroxidase was applied. Two antibodies against distinct keratins were used: a monoclonal antibody MNF116, anti-cytokeratins 5, 6, 8, 17 and 19 (DAKO), characteristic of non differentiated keratinocytes and simple epithelia, and a monoclonal antibody LP34, anti-cytokeratins 5, 6 and 18 (DAKO), characteristic of well-differentiated keratinocytes. Epidermal differentiation markers were also used: a monoclonal antibody anti-human involucrin, for keratinocytes of the stratum spinosum and stratum granulosum and a polyclonal antibody anti-human profilaggrin (ZYMED), for keratinocytes of the stratum granulosum. Most antibodies, without exception, reacted with the various types of BOSCC; The antibody MNF 116 was positive in all carcinomas, independently of their degree of differentiation. The antibody LP34 was positive in all carcinomas, except for one in each differentiation grade group. The anti involucrin antibody was positive in all but one non-differentiated carcinomas. The anti profilaggrin antibody was positive in only two moderately differentiated carcinomas, in all but one well-differentiated carcinomas, and in all but one non-differentiated carcinomas.
- Immunohistochemistry studies on bovine squamous cell carcinoma morphological characterization of epidermal cell proliferation and differentiation markers and characterization of cytokeratinsPublication . Vala, Helena; Fondevila, D.; Carvalho, T.; Pinto, C.; Peleteiro, C.; Pinho, M.; Ferrer, L.Bovine Ocular Squamous Cell Carcinoma (OSCC) is a general designation for a group of primary neoplasias of keratinocytes arising from ocular tissues, especially the lids and particularly the third eye lid. OSCC has been diagnosed all over the world with high prevalence, being the most common bovine tumour and the one causing the most significant economic losses (Hamir & Parry, 1980; Dennis et al., 1985, Heeney & Valli, 1985; Wilcock, 1993). In Portugal, the frequency of these tumours is particularly high in the Azores, where in S. Miguel Island a large number of cattle affected with OSCC is rejected for consumption at slaughter. OSCC is the second most frequent neoplasia after urinary bladder tumours, representing 21% of all cases of rejection due to neoplasia (Pinto et al, 1996). Several reasons have been advanced to explain this situation namely the fact that animals stay in pasture all year around, with a prolonged exposition to day light and benefiting from few shelters. The ingestion of toxic plants present the pasture could also give rise to photosensitazation problems, either primary or due to hepatic toxicity, that could generate predisposing conditions to the development of OSCC.
- Neoplasias em bovinos de São Miguel – Açores. II – Estudo anatomohistopatológicoPublication . Pinto, C.; Medeiros, F.; Alves, A.; Pires, M.; Rodrigues, P.; Vala, Helena; Seixas, F.; Durão, F.; Peteleiro, C.; Peña, L.; Sánchez, B.