A study of the process of apoptosis in animals infected with the contagious ecthyma virus.

Contagious ecthyma virus (CEV) is a disease caused by a parapoxvirus, also is a potent genetic carrier with the capacity for regulating apoptosis in the cells of infected skin, a mechanism that serves for evading the immune response of the host. It has been suggested that the virus may remain in the skin and be able to cause repeated infections in the same flock. The effect of infection as well as the presence of contagious ecthyma virus was evaluated in terms of lesions and apoptosis in the skin of animals, infected both naturally and experimentally. Samples used were obtained from a naturally infected sheep, 5 goats inoculated with CEV and a negative control. Samples obtained were longitudinally sectioned and processed using photon and electron microscopy, and embedded in paraffin and araldite. Samples embedded in paraffin were sectioned in 5 microm of thickness and dyed with orange eosin-hematoxilin G and Gomori's trichrom stain, apoptosis was demonstrated by the TUNEL assay, the viral antigen was revealed using polyclonal antibodies, and the presence of lymphocytes CD4+ and CD8+, with monoclonal antibodies. The samples processed in resin were cut to obtain semi-fine sections and dyed with toluidine blue-borax, and the ultra-fine sections were impregnated with lead citrate and uranyl acetate. Observations were similar in both, the natural infected animal and the experimental group. Infiltration was observed as well as images suggestive of a process of apoptosis. The TUNEL assay demonstrated that the number of epithelial cells undergoing apoptosis diminished during the process and increased among defense cells, until they almost disappeared at the beginning of healing. Cells undergoing apoptosis were located near the sebaceous glands and pilose follicles. The infiltrated lymphocytes gradually diminished. The viral antigen was observed in cells with morphology suggestive of apoptosis, located in sebaceous glands and pilose follicles. Using electron microscopy, cells with morphology compatible with that of lymphocytes were observed to be undergoing apoptosis, but there was little evidence of viral particles.

Contribution to the determination of the chemotherapeutic drug G1 in biological fluids.

A sensitive gas chromatographic method for the quantitative determination of the new antibacterial and antifungal drug G1, 1-(5-bromofuran-2-yl)-2-bromo-2-nitroethene, has been optimized. The method involves a fast and single extraction step from spiked serum and urine samples. The G1 drug was quantified using an internal standard method and by means of a nitrogen-selective detector. The results are statistically significant and show that mean levels of G1 as low as 1 microg ml(-1) can be measured accurately.