A. E. Silva

Carcinogênese hormonal e neoplasias hormônio-dependentes

The hormone-dependent neoplasms may originate from genetic mutations resulting the normal cells proliferation or of the cells multiplication already transformed by other carcinogen. Some hormones and anti-hormones drugs are being used with success in the treatment of those neoplasm in humans. In spite of the elevated frequency of the hormone dependent neoplasms in the animals, the use of antagonistic hormones and anti-hormones drugs, as well as the identification immunohistochemical of hormones receptors in the neoplasm is not already part of the veterinary hospitals routine.

Uterine leiomyoma in chimpanzee (Pan troglodytes)

Uma chimpanze de 22 anos de idade foi necropsiada com historico clinico de anorexia, vomitos frequentes e desidratacao consequentes a gastrite iatrogenica. Macroscopicamente, o utero apresentava-se aumentado de volume, com o lumen totalmente ocluido por nodulos firmes, esbranquicados e coalescentes que se estendiam para o miometrio. Histologicamente, os nodulos eram constituidos por leiomiocitos bem diferenciados dispostos em varias direcoes e com coloracao caracteristica pelo tricromio de Gomori e Masson. Pela imunoistoquimica, as celulas neoplasicas apresentavam marcacao forte e difusa de receptores para progesterona e estrogeno, assim como de actina alfa de musculo liso. Algumas celulas neoplasicas e o estroma apresentavam marcacao para vimentina e poucas celulas neoplasicas foram positivas para MIB-1. Com base nas caracteristicas mosrfologicas e imunoistoquimicas foi firmado o diagnostico de leiomioma uterino.

Efeito do hipotireoidismo no tumor de Ehrlich sólido em camundongos fêmeas castradas e não castradas

The effect of hypothyroidism on the solid form of the Ehrlich tumor in intact or castrated adult female mice was studied. Hypothyroidism was induced by treatment with propylthiouracil (PTU). Forty mice were divided into four groups: castrated hypothyroid, intact hypothyroid, castrated euthyroid, and intact euthyroid. The mice were inoculated with suspension cells into the left footpad. The tumor growth curve was determined by measuring the inoculated footpad during 12 days. At the end of the experimental period the mice were sacrificed. Hypothyroidism was associated with a reduction in size of the tumor only in the castrated animals. Although the neoplastic growth was lower, mean nuclear diameter, number of nucleolar organizer regions (NORs), and area of mitosis were higher. In conclusion, hypothyroidism resulted in a delayed growth of the tumor, but it did not affect the malignant features of the neoplastic cells. In addition, the isolated effect of castration caused only mild alterations, whereas hypothyroidism associated with castration resulted in a more prominent delay in the growth rate of the Ehrlich tumor.

Mesotelioma pleural com metástase renal em gato

It has been described the anatomopathological and immunohistochemical characteristics of a multinodular neoplasm distributed in the parietal and visceral pleurae, pericardium, thoracic portion of the diaphragm and renal cortex of an eight year-old, female, mixed breed, cat. Based on the anatomopathological and immunohistochemical findings it was firmed the diagnosis of biphasic pleural mesotelioma with renal metastasis.

Model of induction of thyroid dysfunctions in adult female mice

Descreve-se a elaboracao de um novo protocolo de inducao ao hipertireoidismo e hipotireoidismo em camundongos, por meio da administracao de tiroxina e propiltiouracil, respectivamente, na agua de beber. As drogas foram administradas a camundongos femeas adultas Swiss por 30 dias para obtencao das disfuncoes tireoidianas sistemicas. A inducao de hipertireoidismo e hipotireoidismo nos animais foi confirmada pela analise histomorfologica e histomorfometrica da glândula tireoidiana ao final do experimento, quando observou-se o estado de disfuncao glandular nos animais submetidos ao tratamento.

Cytological and histopathological aspects of lipomas in Bothrops moojeni

O presente relato descreve os achados citologicos e histologicos de seis neoplasias benignas em cinco ofidios da especie Bothrops moojeni mantidas em cativeiro por um periodo medio de 11,4 anos. Os animais apresentavam nodulos subcutâneos com localizacao variada desde o terco anterior ate a porcao mediana. Os exames citologico e histopatologico revelaram tratar-se de tumores lipomatosos benignos compativeis com o subtipo lipoma fusocelular.

Tumor maligno da bainha de nervo periférico em cães: relato de três casos

Anatomo-clinical and immunohistochemical findings on three dogs with peripheral nerve sheath tumors assisted at the veterinary hospital are described. Animals showed different clinical signs depending on the location of the tumor. According to microscopy, neoplasia in all the three case were invasive and comprised of pleomorphic, anaplastic with polygonal to very elongated fusiform shapes arranged in a diffuse solid pattern, forming interwoven bundles in some areas. Immunohistochemistry was used to better classify these tumors. The diagnosis of peripheral nerve sheath tumor was confirmed by histological and immunohistochemical findings.

Condrossarcoma primário de língua em cão

A 10 year old female Boxer was taken dead to veterinary hospital for a necropsy without any clinical history, showing a growth on the dorsal part of the tongue. Based on the histopathological findings mesenchymal chondrosarcoma was diagnosed. This report describes the first case of chondrosarcoma on the base of the tongue in veterinary medicine.

Linfoma ósseo em cão

It was reported one case of primary bone lymphoma in eight year-old bitch, Fila, with history of anterior limbs paralysis and side lied. A cervical vertebrae neoplasm was suspected and in view of the poor prognosis, the animal was euthanatized. Based on the anatomopathological and histological findings it was firmed the diagnosis of primary bone lymphoma.

Resposta da paratireóide de ratas às variações do cálcio e fósforo plasmáticos no hipertireoidismo e hipogonadismo

ABSTRACT Eighty four parathyroids of castrated and intact adult female Wistar rats kept under hyperthyroidism state for 30, 60 or 90 days were studied. Two euthyroid goups, one castrated and another intact were used as controls. At the end of each period, blood was collected and the concentrations of free T4, calcium and phosphorus were determined. The parathyroids were analysed microscopically and % of nuclei, cytoplasm and stroma were determined. Hypocalcemia that was observed in castrated and intact euthyroid rats at 60 days was reverted after 90 days due to parathyroid hypertrophy. In hyperthyroid groups, hypocalcemia and hyperphosphatemia were progressive and did not revert at 90 days. In conclusion, castration revert hypocalcemia due to the increase of parathyroid activity. In spite of parathyroid hypertrophy, hyperthyroid state with functional gonads did not return to isocalcemia and isophosphatemia state. In addition, under the association of hyperthyroidism-castration, parathyroid did not respond to progressive hypocalcemia and hyperphosphatemia. Keywords: rat, parathyroid, hyperthyroidism, castration