Gleidice Eunice Lavalle

Cox-2 Expression in Canine Mammary Carcinomas: Correlation with Angiogenesis and Overall Survival

Mammary tumors are among the most common neoplastic processes in female dogs. Prostaglandin E2, the catalytic product of Cox-2, may promote tumor development and angiogenesis. It has been investigated in several human cancers and also correlated with the evolution of the disease. However, the clinical implications of tumor pathology require more investigation in veterinary medicine. Angiogenesis is essential for the growth and metastasis of major solid tumors and has been correlated with prognosis in human and canine breast cancer. The aim of this study was to evaluate Cox-2 expression and microvessel density in canine mammary carcinomas and to correlate them with overall survival of the animal. Cox-2 and angiogenesis were assessed by immunohistochemistry in 46 mammary carcinomas (19 ductal and 27 metaplastic) and in healthy mammary glands. To assess tumor angiogenesis, microvessel density (MVD) was determined by CD31 staining. Immunostaining revealed that 46/46 (100%) of the tumors were positive for Cox-2 and CD31, and there was no statistical difference among tumor types. Cox-2 protein expression correlated positively with CD31 staining (r = 0.3742, P = .0104) but did not correlate significantly with tumor type. Longer overall survival was observed in metaplastic carcinomas (P = .028), in tumors with low microvessel density (P = .0002) and with low Cox-2 score (P = .01). Our results demonstrate that increased microvessel density and increased Cox-2 expression were linearly related in the canine mammary tumors studied and were also related to worse prognosis and shorter overall survival. This suggests that Cox-2 inhibitors could be an alternative for the treatment and control of advanced neoplastic mammary disease in female dogs.

Evaluation of adverse effects in tamoxifen exposed healthy female dogs

BackgroundMammary tumors are among the most frequent neoplasms in female dogs, but the strategies employed in animal treatment are limited. In human medicine, hormone manipulation is used in cancer therapy. Tamoxifen citrate is a selective inhibitor of oestrogen receptors and exerts a potent anti-oestrogen effect on the mammary gland. The aim of this study was to evaluate the adverse effects when exposing healthy female dogs to tamoxifen.MethodsTamoxifen was administered for 120 days at a dose of 0.5 or 0.8 mg/kg/day to either intact or spayed female dogs. The effects were assessed through clinical examination, haematology, serum biochemistry, ophthalmology and bone marrow aspirate examination. Ovariohysterectomy was performed and the uterus examined by histopathology.ResultsVulva oedema and purulent vaginal discharge developed with 10 days of tamoxifen exposure in all groups. Pyometra was diagnosed after around 90 days of exposure in intact females with frequencies increasing during the following 30 days of exposure. Up to 50% of dogs within the groups developed retinitis but none of the dogs had signs of reduced visual acuity. The prevalence of retinitis in each group was similar after 120 days of exposure. Haematological, biochemical and bone marrow changes were not observed. Due to the high risk of developing pyometra after prolonged exposure to tamoxifen, only spayed animals should be given this medication.ConclusionsA dose of 0.8 mg tamoxifen/kg body weight/day is recommended when treating tamoxifen-responsive canine mammary tumors. Due to the high risk of developing pyometra, ovariohysterectomy is recommended.

Surgical stress and postoperative complications related to regional and radical mastectomy in dogs

BackgroundSurgery is the treatment of choice for regional control of mammary neoplasms in female dogs. Various surgical techniques may be used, as long as mammary gland anatomy, lymphatic drainage, and known prognostic factors are respected. The purpose of this study was to compare surgical stress—including duration of surgery, nociception and hematological changes—and postoperative complications in dogs undergoing regional and unilateral radical mastectomy. Eighteen dogs were selected for each technique. Postoperative pain (nociception), hematological changes, and postoperative complications were compared between the two groups.ResultsThe group treated with radical mastectomy had a longer surgical duration, showed more intense physiological changes, achieved higher scores on nociception scales, and experienced more postoperative complications.ConclusionCompared to regional mastectomy, radical mastectomy was associated with longer surgical duration, greater nociceptive stimulus, greater surgical stress, and higher incidence of postoperative complications in dogs. Although evaluation of long-term results was not a goal of this study, it is suggested that postoperative recovery and patient quality of life should be considered when choosing a surgical approach for treating mammary tumors in dogs.

Mast cells and angiogenesis in canine mammary tumor

Estimou-se a correlacao entre a densidade de microvasos e a densidade de mastocitos em tumores mamarios caninos. Sessenta e cinco amostras de tumores mamarios caninos - 24 benignos e 41 malignos - foram analisadas, pela tecnica rotineira de coloracao com Azul de Toluidina para avaliacao da densidade de mastocitos. Para a avaliacao da angiogenese, foi utilizada a tecnica de imunoistoquimica para expressao de CD31. Nao foram observadas diferencas significativas de mastocitos (P=0.44) ou densidade microvascular (P=0.77) entre tumores malignos e benignos. A correlacao entre densidade microvascular e densidade de mastocitos foi positiva (r=0,39; P=0,011) em tumores malignos. Estes resultados sugerem que os mastocitos podem exercer um importante papel no desenvolvimento de tumores mamarios malignos caninos mediante promocao da angiogenese, similarmente a alguns tumores descritos na especie humana

Histoplasmose cutânea em gato: relato de caso

A case of a cutenous histoplasmosis in a three-year-old male Siamese cat is described. The diagnosis was based on clinical signs and laboratory exams. Dramatic remission of clinical signs was observed with cetoconazol therapy.

Punção aspirativa por agulha fina para diagnóstico de mastocitoma em cães

Fine needle aspiration (FNA) associated with the cytological diagnosis mast cell tumor is a widely employed technique in human medicine, but it is still underused in veterinary medicine. The aim of this study was to demonstrate the efficacy of FNA technique for the diagnosis of mast cell tumors in dogs. Over one year period all dogs referred to the Veterinary Hospital of the Universidade Federal de Minas Gerais with tumor-like formations of the skin were submitted to FNA. In order to detect metastasis, both skin lesions and the regional lymph nodes were subjected to FNA. After surgical removal of the lesions, histological examination indicated a complete agreement with the cytological diagnosis. In conclusion, FNA technique is a good choice for diagnosis of mast cell tumors in dogs. In addition, FNA allows an adequate and early therapeutic planning.

Absence of significant adverse events following thalidomide administration in bitches diagnosed with mammary gland carcinomas

The aim of the study was to evaluate the incidence of adverse events (AEs) in female dogs diagnosed with advanced clinical stage mammary gland neoplasms following treatment with thalidomide. A prospective analysis of 29 female dogs treated with a high dose (HD) of 20 mg/kg/day of thalidomide for three months followed by a low dose (LD) of 10 mg/kg/day of thalidomide for three months was performed. All patients underwent physical examination, complete blood count, serum biochemistry profile, thoracic radiographs, and abdominal ultrasound analysis before the treatment and after the HD and LD. Clinical AEs were absent in 16/29 (55.17 per cent) patients following HD. An initial 3–5 day period of somnolence was described in 4/29 (13.79 per cent), prolonged somnolence in 5/29 (17.24 per cent), a short period of somnolence lasting only a few hours in 3/29 (10.34 per cent), and difficulty to rouse was described in 5/29 (17.24 per cent) cases. Two patients (6.89 per cent) presented with prolonged somnolence that interfered with activities of daily living, resulting in anticipation of the dose reduction to the proposed LD after 15 days of the HD treatment. Following dose reduction, AE improvement was observed in all patients. Albeit remaining within the reference ranges, erythrocytes, haematocrit, total leucocyte count, neutrophils, lymphocytes, monocytes and γ-glutamyltranspeptidase showed significant alteration associated to thalidomide treatment.

Prognostic significance of tissue and serum HER2 and MUC1 in canine mammary cancer

The aim of our study was to compare serum levels and protein tissue of human epidermal growth factor receptor–2 proto-oncogene (HER2) and mucin 1 (MUC1) using an antigen-capture enzyme-linked immunosorbent assay and immunohistochemistry (IHC) in canine mammary carcinomas and investigate how the 2 markers correlate with dogs with metastasis and without metastasis to a regional lymph node. Forty-eight female dogs were selected, including 14 with non-metastatic cancer, 14 with lymph node metastasis, and 20 healthy animals. Serum samples were collected from all the animals and tissues from 28 dogs with malignant mammary tumor with or without metastasis for evaluated HER2 and MUC1 expression. Tissue sample were evaluated for MUC1 and HER2 immunoexpression by IHC. The results showed measurable serum levels of MUC1 and HER2 in all groups. While serum MUC1 levels were significantly higher in animals with metastasis than the other 2 groups, no increase was observed in HER2 serum levels. The MUC1 IHC results showed that only membrane immunostaining was significantly different between the groups. Statistically, there was an association between immunostaining and the serum HER2 levels. Our results indicate that serum concentrations of HER2 and the IHC staining pattern for HER2 in primary tumor do not correlate with the presence of regional metastasis. However, increased concentrations of MUC1 in the serum of dogs with mammary cancer are associated with the presence of metastasis to regional lymph nodes. A membrane pattern of IHC staining for MUC1 in the primary tumor suggests that metastases to regional lymph node are present.

Anastomose cólon-trígono vesical em cães

Realizou-se anastomose colon-trigono vesical em 12 caes adultos (cinco machos e sete femeas), sem raca definida e clinicamente normais. Todos os animais mantiveram a continencia urinaria imediatamente apos a cirurgia. Amostras da regiao de transicao colon-trigono vesical foram colhidas aos 30 e 60 dias apos a cirurgia para exames histopatologicos. Observou-se infiltrado inflamatorio mononuclear na regiao de anastomose com invasao do epitelio de transicao da bexiga sobre a mucosa do fragmento intestinal. A tecnica mostrou-se simples e eficiente para a reparacao da bexiga, com o colon funcionando como substituto da bexiga, preservando as funcoes renal e vesical.

Leiomiossarcoma pulmonar e renal em cão: relato de caso

This report describes a case of pulmonary and renal leiomyosarcoma in a nine-year-old Siberian Husky male dog with a history of progressive weight loss. Clinically, the animal had mildly pale mucosae and severe abdominal pain. Kidneys enlargement also was observed. On hemogram, a mild anemia was observed. On urinalysis, isosthenuria and renal epithelial cells were detected. Urea nitrogen and creatinine levels were normal. Bilateral renal neoplasia was diagnosed by laparotomy and the animal was submitted to euthanasia. On necropsy, many whitish firm nodules ranging from 0.5 to 4cm in diameter were found in the kidneys. The region of the hilum and the left apical lobe of the lungs had a mass with 11´ 7cm in area which was well vascularized and had an irregular whitish surface with either firm or friable areas. There was also a whitish firm nodule with 1cm in diameter in the right apical lobe. Histological sections were stained by hematoxilin-eosin, Masson and van Gieson. Positivity for the vimentin and smooth muscle actin were detected by immunohistochemistry. Cytokeratin 1, 5, 10, 14, 8 and 7, protein S100 and CD68 markers showed negative reactions. The anatomopathological and immunohistochemistry features allowed the diagnosis of pulmonary and renal leiomyosarcoma. However, it was not possible to determine the primary site of the neoplasia.