Amyloid-producing odontogenic tumour (calcifying epithelial odontogenic tumour) in the mandible of a Bengal tiger (Panthera tigris tigris).

A 13-year-old male tiger (Panthera tigris tigris) had a marked mandibular swelling noticed 12 months earlier and associated with progressive anorexia and weight loss. Radiological and post-mortem examination revealed a mass (13x15 cm) which was firm and poorly defined, with destruction of the adjacent bone tissue. Histologically, the mass was poorly demarcated, with infiltrative growth, and composed of nests, cords and islands of epithelial cells with characteristic basal cell features. Also observed were extensive squamous metaplasia, ghost cells, stellate reticulum, and fibroblastic connective tissue stroma containing inflammatory cells. A prominent feature of this tumour consisted of abundant nodular deposits of congophilic amyloid-like material with partial mineralization (Liesegang rings). Immunohistochemically, the neoplastic cells and the amyloid-like material were positive for pancytokeratin and negative for vimentin. The findings supported the diagnosis of an amyloid-producing odontogenic tumour (APOT), also known as calcifying epithelial odontogenic tumour in man and animals.

Streptococcal lid necrosis in previously healthy children.

Fulminant preseptal eyelid cellulitis developed in two previously healthy children, aged 17 months and 8 years, following minor trauma. Despite appropriate intravenous antibiotic therapy, lid necrosis with ulceration developed in both patients. In both cases group A beta-hemolytic Streptococcus was the causative agent. Spontaneous granulation of the ulcerated areas resulted in cicatricial defects, which in one case may require surgical correction. Neither child had a past history of susceptibility to infection. Group A beta-hemolytic Streptococcus has been known to cause lid gangrene, but almost all previously documented cases occurred in debilitated or elderly patients.

Chromatographic identification of a biochemical alteration in the aqueous humour of megalophthalmic Black Moor goldfish.

PURPOSE: To observe if any biochemical abnormalities exist between the eye of megalophthalmic and non-megalophthalmic goldfish by high-performance liquid chromatography (HPLC). METHOD: Aqueous humour and sera from megalophthalmic and non-megalophthalmic goldfish were subjected to HPLC and monitored by photodiode array detection (Waters, MA, USA). RESULTS: An unusual accumulation of a compound with a UV absorption maximum at 290 nm was observed in the aqueous humour of megalophthalmic eye. This compound was also present in the sera of both normal goldfish and one of its megalophthalmic mutant. However, it was significantly elevated in the aqueous humour of the megalophthalmic eye only. This compound concentration was very high in the eye of small fish and its concentration increased only slightly with the expansion of the eye in larger fish. CONCLUSIONS: The presence of this compound in the serum and aqueous humour indicates a specific systemic metabolic variation in Black Moor goldfish not seen other animal species we had studied (humans, bovine, chick, rabbits and rats). The marked elevation of this compound in the megalophthalmic eye indicates a possible association of this compound with the metabolic variation accounting for the expansion of the eye in megalophthalmic goldfish.