Squamous cell carcinoma in an aged German Landrace sow (Sus scrofa domestica).

Skin tumors are rarely observed in pigs, and, in particular, only a few cases of squamous cell carcinoma have been reported. The present case report describes the occurrence of a squamous cell carcinoma located in the skin at the center of the udder of a 14-year-old German Landrace sow. The tumor was spherical and 17.0 cm in diameter. The tissue of the distal pole had a cauliflowerlike appearance, was black and ulcerated with a malodorous exudation. The sow did not show any signs of reduced general condition caused by the tumor. No evidence of metastasis was noted in regional lymph nodes and in the lung. The tumor, which weighed 2.4 kg, was surgically removed. The histopathology revealed infiltratively growing pleomorphic tumor cells and cell aggregations with prominent squamous differentiation. Cells were strongly positive for several cytokeratins by immunhistochemistry. The present findings confirmed the diagnosis of squamous cell carcinoma. After surgery, the sow recovered without complications and remained without recurrence at the follow-up three months later. This is the first report ofa squamous cell carcinoma in the skin in the udder in an old sow.

Expression of p53 in a malignant melanoma of a goat.

A six-year-old brown haired goat was presented due to recurring tissue growth at the base of the right horn. The tumour recurred after repeated surgical excision and the animal was finally euthanized because of poor prognosis. Necropsy revealed a malignant, partly amelanotic melanoma originating from the right horn base with metastases in both frontal sinuses, urinary bladder, pleura, pericardium, second thoracic vertebra, kidney and mesenteric lymph nodes. Diagnosis was confirmed by histopathology and immunohistochemistry. A strong expression of p53, a suppressor of cell proliferation and activator of apoptosis, was detected in numerous tumour cells suggesting an altered protein function.

Mechanisms of insulin-dependent glucose transport into porcine and bovine skeletal muscle.

Euglycemic, hyperinsulinemic clamp tests have shown that adult ruminants are less insulin-sensitive than monogastric omnivores. The present study was carried out to elucidate possible cellular mechanisms contributing to this impaired insulin sensitivity of ruminants. Western blotting was used to measure glucose transporters 1 and 4 (GLUT1, GLUT4) in oxidative (musculus masseter and diaphragm) and glycolytic (musculus longissimus dorsi and semitendinosus) skeletal muscle in the crude membranes of pigs and cows. Muscles were characterized biochemically. To determine insulin-stimulated 3-O-D-[(3)H]-methylglucose (3-O-MG) uptake and GLUT4 translocation, porcine and bovine musculus semitendinosus strips were removed by open muscle biopsy and incubated without and with 0.1 or 20 mIU insulin/ml. GLUT4 translocation was analyzed using subcellular fractionation techniques to isolate partially purified plasma membranes and cytoplasmic vesicles and using Western blotting. GLUT4 protein contents were significantly higher in oxidative than in glycolytic muscles in pigs and cows. GLUT1 protein contents were significantly higher in glycolytic than in oxidative muscles in bovines but not in porcines. The 3-O-MG uptake into musculus semitendinosus was similar in both species. Maximum insulin-induced GLUT4 translocation into musculus semitendinosus plasma membrane was significantly lower in bovines than in porcines. These results indicate that GLUT1 is the predominant glucose transporter in bovine glycolytic muscles and that a reinforced insulin-independent glucose uptake via GLUT1 may compensate for the impaired insulin-stimulated GLUT4 translocation, resulting in a similar 3-O-MG uptake in bovine and porcine musculus semitendinosus. These findings may explain at least in part the impaired in vivo insulin sensitivity of adult ruminants compared with that of omnivorous monogastric animals.