Primary ocular chondrosarcoma in a discus (Symphisodon aequifasciatus).

An adult discus (Symphisodon aequifasciatus) with a history of buphthalmia and anorexia was referred, from an aquarium, for clinical examination. Surgery was performed to enucleate the eye and obtain a definitive diagnosis. Macroscopic examination revealed a yellowish mass that affected the eye. Histologic examination of the mass revealed a poorly demarcated, high cellular infiltrative mesenchymal neoplasm composed of ovoidal-spindloid cells with elongated nuclei and with scant cytoplasm arranged in a solid pattern. Throughout the tumor, there were scattered foci of cartilaginous differentiation that stained deeply with alcian blue and stained metachromatically with toluidine blue. The neoplastic cells were immunolabeled to varying degrees by antibodies against vimentin and SOX-9. Based on morphologic, histochemical, and immunohistochemical characteristics, the tumor was diagnosed as a chondrosarcoma.

Small ruminant lentivirus genotype B and E interaction: evidences on the role of Roccaverano strain on reducing proviral load of the challenging CAEV strain.

Live attenuated vaccines provide the most consistent protective immunity in experimental models of lentivirus infections. In this study we tested the hypothesis that animals infected with a naturally attenuated small ruminant lentivirus field strain of genotype E may control a challenge infection with a virulent strain of the caprine arthritis encephalitis virus (CAEV-CO). Within genotype E, Roccaverano strain has been described as attenuated since decreased arthritic pathological indexes were recorded in Roccaverano-infected animals compared to animals of the same breed infected with genotype B strains. Moreover, under natural conditions, animals double-infected with genotypes B and E appear less prone to develop SRLV-related disease, leading to a putative protective role of Roccaverano strain. Here we present evidence that goats experimentally infected with the avirulent genotype E SRLV-Roccaverano strain control the proviral load of a pathogenic challenge virus (CAEV-CO strain) more efficiently than naïve animals and appear to limit the spread of histological lesions to the contralateral joints.

Ex vivo evaluation of imatinib mesylate for induction of cell death on canine neoplastic mast cells with mutations in c-Kit exon 11 via apoptosis.

Several studies of canine spontaneous mast cell tumours have described mutations in the c-kit proto-oncogene. These mutations produce a constitutively activated product and have been suggested to play a role in the malignant transformation of mast cells. We hypothesize that the selective tyrosine kinase inhibitor imatinib mesylate inhibits signal transduction and induces apoptosis when tested in cutaneous canine mast cell tumour samples positive for mutation in c-kit exon 11. Three-dimensional ex vivo cultures of canine grade II mast cell tumour treated with STI-571 at 48, 72, and 96 h and tested for signal transduction and apoptosis using appropriate assays were used. There was a progressive and significant increase in caspase-3 and TUNEL-positive mast cells compared to the untreated cultures. Additionally, a concurrent reduced expression of Ki67 and BCL-2 was observed. Furthermore, the treated cultures showed a marked reduction of Kit expression. Our results demonstrate that STI-571 induces Caspase-dependent apoptosis in a canine neoplastic mast cells possessing mutations in c-kit exon 11.

Adhesion molecules and cytokine profile in ileal tissue of sheep infected with Mycobacterium avium subsp. paratuberculosis.

Sheep develop clinical diseases after 3-5 years after infection with Mycobacterium avium subsp. paratuberculosis (MAP). Clinical symptoms of paratuberculosis include persistent diarrhea and weight loss due to a chronic inflammation of the small intestine. Tissue alterations in the areas of the ileo-cecal junction are often observed. Here, we investigate the molecular processes underlying tissue damages in intestinal mucosa of 14 sheep showing either tuberculoid or lepromatous form of MAP enteritis. We found that E-cadherins, alpha-catenin and beta1-integrins were present at significant low levels in tissues of sheep affected by lepromatous form and that this pattern was associated with high expression of TGF-beta, IL-10, IL-1beta, and TNF-alpha and with a modest increase of CD4+ and CD25+ T cells. Tissues of sheep with the tuberculoid form showed high expression of IFNgamma, IL-12, and MCP-1 and a significant presence of CD4+ and CD25+ T cells. Finally, anti-transglutaminase (tTG) IgG1 antibodies were detected in sera of infected animal belonging to both groups, as already described for human inflammatory bowel diseases. Our results further stress the similarities in the clinical and histological features between ruminant paratuberculosis and human intestinal inflammatory diseases.