Showing papers by "University of Veterinary Science published in 1979"

Ultrastructural studies of chicken embryo chorioallantoic membrane during incubation.

Abstract: Summary Structural changes taking place in the chorioallantoic membrane (CAM) of embryonated hen's eggs during incubation were followed up by histological, histochemical and electron microscopic methods. The allantoic sac surrounds the amnionic sac and also the yolk sac by the 7th to 11th day, respectively, and forms together with the chorion the CAM. The mesenchymal layer placing between the chorion of ectodermal and the allantoic layer of entodermal origin develops from the somatic and splanchnic-pleure of the parietal mesoderm. The CAM is composed of three different layers, i.e. chorionic epithelium, mesenchyme and allantoic epithelium. The chorion comprises 2 layers of cubical epithelial cells. In between the 2 layers capillaries and directly under the shell membrane vascular sinuses can be found. Blood circulating in the sinuses is separated from the air in the pores of the shell membrane by the adacent epithelial cell-projections of 0,2 μm thickness, the basal membrane (0.1 μm) and the sinus endothelial layer of 0.2 μm thickness. The mesenchymal cells are of star-like form. The allantioc epithelium is built of one layer of fusiform cells with oval-shaped or rod-like nuclei.

Recall phenomenon induced with ovine adenoviruses

Abstract: The evidence of the recall phenomenon was demonstrated in lambs vaccinated against ovine adenoviruses belonging to different serotypes. This phenomenon is of great importance in the specific control of diseases of lambs caused by adenoviruses.