Pulmonary interstitial fibrosis is characterized by a progressive increase in connective tissue in the lung parenchyma. Fibrosis is associated with conditions that result as a consequence of cell mediated responses including graft versus host disease, delayed type hypersensitivity reactions, and granulomas. The hapten-immune animal model for pulmonary interstitial fibrosis correlates the nonresolving fibrosis observed in the lung parenchyma directly with the animal's prior immunization to the hapten. Because the model is patterned after the well studied contact hypersensitivity assay in the skin, the immune response can be directly correlated with a cell-mediated (T-lymphocyte) immune mechanism. Previously, we reported that hapten-immune animals showed increased collagen deposition as identified on routine paraffin fixed slides that were stained with Masson's trichome. In this report, morphometric procedures were used to quantitate the fibrotic lesion. Fibroblasts were harvested from lungs of all treatment groups, cultured, and assayed for collagen production. Once it was determined that collagen production by fibroblasts was similar to that recorded in assays using fresh lung tissue, the fibroblasts were used as a homogeneous cell source for RNA. Total RNA from various treatment groups was used to assess the ratio of mRNA for procollagen I:III using slot and northern blot hybridization procedures. An increased ratio in the procollagen type I:III mRNA was observed in total RNA isolated from fibroblasts from immune and challenged hamsters, and not in samples from all other groups. These results support the hypothesis that the activated T lymphocytes involved in "contact" hypersensitivity-like reactions in the lung regulate not only the quantity, but also the quality of collagen produced by the fibroblasts in the lungs of the hamsters that develop nonresolving fibrosis. The model may be important for the study of skin and pulmonary disease induced by exposure to environmental haptens.

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PubMedDate not supplied

Four cases of neoplasia in captive wild birds.

Four cases of malignant neoplasia in captive wild birds are described: an adenocarcinoma of the adrenal gland in a Mountain duck (Tadorna tadornoides), a malignant melanoma in the thoracic cavity of a Combed duck (Sarkidiornis melanotos), a hepatocellular carcinoma with pulmonary metastasis in an Asian Purple Swamphen (Porphyrio porphyrio), and an undifferentiated carcinoma in the abdomen with metastasis to skeletal muscle in a White-Breasted Waterhen (Amaurornis phoenicurus). The tumors were diagnosed during a 1-year period and represented an incidence of neoplasia of 3.1%. These appear to be the first documented cases of a malignant adrenal gland tumor and a non-ocular melanoma in the order Anseriformes. The hepatocellular carcinoma failed to react with an immunoperoxidase stain for alphafetoprotein.

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PubMedDate not supplied

Metastatic malignant melanoma in a mandarin duck (Aix galericulata).

A biopsy taken from a mass on the dorsal surface of the bill of an adult female mandarin duck (Aix galericulata) was diagnosed as a malignant melanoma by light microscopy. Two months later, the tumor had enlarged considerably; the duck developed severe dyspnea and was euthanatized. At necropsy, there were metastases to lymphoid tissues in the lower regions of the neck. To our knowledge, this is the first report of a malignant melanoma in a mandarin duck.

Animals↗