Imunohistoquímica em órgãos de tilápias-do-Nilo imunizadas com antígeno insolúvel de Streptococcus agalactiae

Pós-graduação em Medicina Veterinária - FCAV

O papel da ciclooxigenase-2 da pressão arterial na lesão renal de ratos submetidos à infusão contínua de angiotensina II

Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP)

Role of ATM and PTEN in prostatic carcinogenic dog prostate: validation of aCGH results

The canis lupus familiares is the only species besides human that spontaneously develop prostatic carcinoma (PCa). In addition, the metastatic sites are similar to those frequently reported in men. For these reasons, the dog is the best natural model to study the molecular mechanisms in PCa development providing a natural animal model for treatment by molecular targets. Previously, we investigated copy number alterations by arrayCGH (Canine Genome CGH Microarray 4x44K-G2519F, Agilent Technologies) in canine prostatic lesions: 3 benign prostatic hyperplasias (BPH), 4 proliferative inflammatory atrophies (PIA), and 14 PCa. Five histologically normal prostatic tissues were used as reference. Genomic alterations were evaluated using Genomic Workbench Standard Edition 5.0.14. This previous study revealed significant copy number losses of Atm and Pten exclusively in PCa. In the present study, ATM and PTEN immunoexpression were investigated using a tissue microarray (TMA) containing 149 canine prostatic paraffin-embedded lesions (BPH, PIA and PCa) collected from 67 animals. Immunohistochemical reactions were performed using the polyclonal rabbit antibody anti-PTEN (Santa Cruz Biotech, 1:50) and anti-ATM (Abcam, 1:50). The sections were developed with diaminobenzidine (DAB) and peroxidase. The immunohistochemical staining was assessed in each core by the distribution of positive cells for each antibody per lesion (score 1: <25% cells positive, 2: 26% to 50%, 3: being 51% and 75% and 4:> 75%) and intensity (1: weak, 2: moderate, 3: intense). Chi-square or Fisher exact test was used to determine the association between the categorical variables using GraphPad Prism 5 (GraphPad Software Inc., La Jolla, CA). Distribution of positive cells did not differ among lesions. PCa and PIA showed more samples with weak intensity for ATM when compared to normal prostatic tissue and BPH (PCa: p=0,032 and PIA: p=0,025). Benign prostatic hyperplasia and normal samples presented intense PTEN immunostaining than PCa (p=0,021) and PIA (p=0,0013). These results suggest that ATM and PTEN proteins expression in canine prostatic carcinoma are downregulated possibly by copy number losses. These findings are similar from those described in prostate carcinomas from human corroborating for the use of dogs as a natural model to study prostatic disease in men.

Undifferentiated pulmonary adenocarcinoma of clear cells associated to hypertrophic osteopathy in a dog

Background: Most of the primary pulmonary tumors in dogs are malignant and from epithelial origin, being bronchioalveolar tumors more prevalent. Adenocarcinoma of clear cells, however, is a very rare pulmonary tumor and its origin is still unknown. It is related to several clinical abnormalities, including hypertrophic osteopathy, an unusual paraneoplastic syndrome characterized by a periosteal reaction along the shaft of long bones. Because of the unusual presentation of the pulmonary adenocarcinoma, the aim of this study was to describe the radiographic, histopathological, and immunohistochemical fi ndings of a dog affl icted with hypertrophic osteopathy secondary to an undifferentiated pulmonary adenocarcinoma of clear cells. Case: A 12-year-old, 45 kg, not castrated male Great Dane dog was presented with painful swelling of all four limbs and moderate respiratory distress. Radiographic examination and computed tomography of the limbs showed palisade-like periosteal bone proliferation involving radius, ulna, femur, patella, tibia, fi bula, tarsus, metacarpal, metatarsal and digits, suggesting hypertrophic osteopathy. Radiographic examination and computed tomography of the lungs also showed a round mass well delimited localized in the right diaphragmatic lobe. A lobectomy of the right diaphragmatic lobe and partial lobectomy of accessory lobe were performed. A poorly differentiated clear squamous cell carcinoma was diagnosed by histological examination. An immune-panel of CK5/CK6, CK7, p63 and TTF-1 was used for immunophenotyping. Immunostaining was weakly positive for CK5/CK6 and negative to all others. Therefore, the diagnosis was poorly differentiated clear cell adenocarcinoma. The dog showed improvement in clinical signs seven days after surgery. One month postoperatively, radiographic examination of the limbs showed less intense periosteal reaction and initiation of bone remodeling. Discussion: Primary pulmonary tumors are considered very infrequent in small animals, but its true incidence rate is dif- fi cult to establish in animal populations. The histological origin of the tumor in the present case, as verifi ed in the literature, is not well established by histological analysis. In these situations, the immunohistochemistry panel may be useful. The modifi cation of the diagnosis between histological analysis and by immunohistochemistry, among other factors, might be due to transdifferentiation from one phenotype to another at various stages in the neoplastic process. The clear cell appearance observed in this case may be verifi ed in all types of carcinoma due to intracellular accumulation of glycogen, most of which is dissolved during the preparation of paraffi n sections. This uncommon neoplasm apparently did not infl uence the radiographic or tomographic fi ndings of the hypertrophic osteopathy in the present case. The frequency of metastases depends on the histological type of the tumor, being common in the pulmonary adenocarcinoma and usually to tracheobronchial lymph nodes and pulmonary parenchyma. Although in this case the imaging studies did not show metastases to other pulmonary lobes, the histological exams showed metastatic lesions that may be associated to the dog’s death after the surgery.

T-cell lymphoma in the tongue of a dog with cutaneous and striated forelimb muscle involvement

Background: Primary tongue tumors rarely affect dogs and correspond to 4% of tumors involving the oropharynx. Until now, primary tongue lymphoma had not been reported. However, lymphoma involvement in the skeletal muscle, although quite unusual, was described in the literature in four cases. Cutaneous lymphoma is another rare extranodal manifestation. The objective of this report is to describe a case of T immunophenotype lymphoma occurrence, whose manifestation is atypical, not only because it is situated in the tongue muscle but also because of the subsequent involvement of the striated musculature of the left forelimb and the skin, which showed unfavorable evolution. Case: A female seven-year-old mongrel was seen showing a regular lump in the base of the tongue, 3 cm in diameter, not ulcerated and of fi rm consistency, with halitosis as the only clinical sign of the disease. Incisional biopsy of the lump was performed and histopathology verifi ed that it was large cell lymphoma. The material was sent for immunohistochemical evaluation and was characterized as T immunophenotype lymphoma by positive CD3 and negative CD79a marking. The CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy protocol was established as treatment and after the fi rst chemotherapy session there was partial remission of the mass, measuring 2 cm in diameter. The lump, however, remained stable in the following sessions. Thirty days after the diagnosis of lymphoma, the animal began to show lameness of the left forelimb and swelling near the head of the left humerus. A muscle mass, fi rm in consistency, progressing fast, presented a signifi cant increase, just three weeks after its appearance. Two skin lesions, arcuate, erythematous and pruritic also appeared in the dorsocervical and ventral-abdominal region. Incisional biopsy of these lesions was performed and the histopathological diagnosis confi rmed muscle and cutaneous large cell lymphoma and immunophenotype compatible with T cells (positive CD3 and negative CD79a). Due to disease advance, even during chemotherapy, a rescue protocol of L-asparaginase administration followed by lomustine and prednisone was proposed. Even with the rescue protocol there was no remission of the tumors and the case was classifi ed as progressive. The animal of this report died after completing the fi rst cycle of chemotherapy protocol, with a survival of 92 days. Discussion: Despite the fact that clinical behavior of primary lymphoma in dogs’ skeletal muscle is unknown, it is believed that, as in humans, it can be associated with chronic infl ammation or neoplastic cell invasion by proximity of the tumor or metastasis, which could justify the dissemination of the lymphoma reported here from the tongue to other tissues. However, appearance of concurrent independent lymphomas cannot be ruled out. As observed in the three cases of primary muscular lymphoma, the dog of this report had low response to therapy and short survival. This report presents the fi rst case of lymphoma in tongue with subsequent skin and left forelimb skeletal muscle involvement described in the literature. The clinical outcome corroborates the aggressiveness of muscular lymphoma observed in the other reports and also suggests that both tongue and other skeletal muscle tumors should be included in the differential diagnosis of canine lymphoma.

MMP-2 and TIMP-2 in male and female prostates of mongolian gerbil: effects of hormonal manipulation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da prática de exercício físico (natação) de intensidade moderada no estresse oxidativo, hormônios sexuais e proliferação pancreática de ratas diabéticas prenhes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)