Immunocharacterization of matrix metalloproteinase-2 and matrix metalloproteinase-9 in canine transmissible venereal tumors.

Matrix metalloproteases (MMPs) are endogenous proteases that are responsible for degradation of extracellular matrix (ECM) proteins and cell surface antigens. The breakdown of ECM participates in the local invasion and distant metastases of malignant tumors. Canine transmissible venereal tumor (CTVT) is a naturally occurring contagious round cell neoplasm of dogs that affects mainly the external genitalia of both sexes. CTVT generally is a locally invasive tumor, but distant metastases also are common in puppies and immunocompromised dogs. We investigated the immune expressions and activities of MMP-2 and MMP-9 in CTVT. The presence of these enzymes in tumor cells and tissue homogenates was demonstrated by immunohistochemistry and western blotting. We used gelatin substrate zymography to evaluate the activities of MMP-2 and MMP-9 enzymes in tumor homogenates. We found that tumor cells expressed both MMP-2 and MMP-9. Electrophoretic bands corresponding to MMP-9 and MMP-2 were identified in immunoblots and clear bands that corresponded to the active forms of MMP-2 and MMP-9 also were detected in gelatin zymograms. Our study is the first detailed documentation of MMPs in CTVT.

Perosomus elumbis in a Holstein calf infected with bovine viral diarrhea virus.

The detection of bovine viral diarrhea virus (BVDV) in a female Holstein calf presented with perosomus elumbis, a congenital anomaly, is reported here. A cow with dystocia was evaluated and an abnormal dead calf was detected during vaginal examination. The calf was retrieved via caesarean section and exhibited abnormalities characteristic of PE, such as vertebral and pelvic malformations. These abnormalities were further confirmed using radiographic and necropsy examinations. At necropsy cerebellar hypoplasia was an additional finding, which is a typical lesion associated with bovine virus diarrhea (BVD). Several tissue samples from the calf were tested for the presence of antigens of BVDV and bovine herpesvirus-1 (BHV-1) by ELISA. In addition, sera samples from the dam and calf were tested for the presence of antibodies against BVDV, BHV-1, and bluetongue disease virus (BTV) using a virus neutralization assay. Results indicated that the calf was congenitally infected with BVDV, whereas there was no evidence for the presence of BHV-1 and BTV. In the dam's serum no antibodies against BVDV, BHV-1, and BTV were detected. Even though the etiology of perosomus elumbis is unknown, BVDV, which causes fetal anomalies at early gestation in cows, may have been a contributing factor in this case.

Unresectable huge sternal and mediastinal metastasis of follicular thyroid carcinoma; radiotherapy as first-line and palliative therapy.

Distant metastases as initial manifestation of follicular thyroid carcinoma is rare. We report a case of an unusual initial presentation of follicular thyroid carcinoma on follow-up. A 52- year-old woman presented with a 12-month history of progressively enlarging mass in the anterior chest wall. The mass was fixed to the chest wall, measuring 12 x 10 cm in diameter. Computed tomography demonstrated a lobulated soft-tissue mass (17 x 11 x 6 cm) destructing sternum and extending into the anterior mediastinum. There was no lung metastasis. Invasion of tumor to the ascending aorta, superior vena cava, and right atrium could not be excluded. Multiple lymph nodes were observed in the supraclavicular regions. Ultrasonography of the thyroid gland showed 46 x 37 mm nodule in the left lobe with milimetric gross calcifications and cystic-necrotic areas. Hyperthyroidism was detected. Biopsy from this nodule and the sternal mass revealed typical histology of follicular carcinoma. She was considered inoperable. Since there was huge tumor burden and iodinated contrast exposure for several times during evaluation, we decided to treat the patient with external beam radiotherapy (EBRT) rather than radioiodine as first-line therapy. After a course of conventional radiation with 50 Gy in 25 fractions over 4 weeks, encompassing the thyroid bed and the gross disease, tumor regressed remarkably in 6 months. In conclusion, when surgical resection is not possible, EBRT may be used for palliative purpose to obtain local control for extensive disease as first-line therapy. The indications of EBRT for differentiated thyroid cancer still remain poorly defined.