Upper alimentary tract papillomas in calves related to papillomavirus infection.

This study reports 3 cases of spontaneous papillomavirus infection in 1-week-old calves. Thickening of the omasum and abomasum wall, with acute inflammation, necrosis, ulceration, and neoplastic changes were seen in 1 calf. In the other 2, small papillomas were observed in the omasal mucosa, exhibiting proliferation of the parakeratinized epithelium. Papillomavirus antigens were detected by immunohistochemistry and virus-like particles were seen through electron microscopy.

[Adaptation of an immunohistochemistry protocol for the detection of Leptospira spp. in samples of formaldehyde-fixed tissue]. / Adaptación de un protocolo de inmunohistoquímica para la detección de Leptospira spp. en muestras de tejido fijado en formaldehído.

The immunohistochemistry technique was evaluated in tissue samples fixed in formaldehyde saline solution 10 % and included in paraffin to be used as a lab method allowing to identify leptospires in tissues. Samples obtained from the experimental inoculation of 8 guinea pigs carriers of L. interrogans Pomona isolated from a clinical case were used. The disease was reproduced in a lab model. The histologic sections of the kidneys of the animals inoculated were subjected to histopathological studies, immunofluorescence, Warthin-Starry stain, and immunohistochemistry technique using formaldehyde-fixed samples. This technique proved to be an efficient tool for the diagnosis of leptospirosis.