ABSTRACT
An on-site screening test for the detection of beta-agonistic drugs in urine was developed. The test is based on the principle of an enzyme immunoassay in polystyrene tubes. Results can be obtained by visual interpretation or by measurement with a differential photometer. The total time required to perform the test for a set of samples (five samples+one cut-off standard) is about 20 min (visual interpretation) with an additional 2 min for an instrumental interpretation. Owing to its speed and simplicity, the test can be performed in slaughter- and farmhouses. In the tube test, a mixture of antibodies raised against clenbuterol and salbutamol is used, which makes this test sensitive towards a range of beta-agonists (multi-test). In this study, the test was applied to the screening of 269 bovine urine samples. Bovine urine samples with a level of 3 ng ml-1 of clenbuterol and higher were found positive with this on-site test. Owing to fewer matrix effects, a lower level (1 ng ml-1) could be detected in calf urine. The detection of positive samples at the place of sampling can result in more effective control of the illegal use of beta-agonists.
Subject(s)
Adrenergic beta-Agonists/urine , Immunoenzyme Techniques , Animals , Cattle , Methods , Sensitivity and SpecificityABSTRACT
Five-month-old male goats were treated with 25 mg diethylstilbestrol dipropionate (DES-DP) by a single intramuscular injection, causing characteristic histological alterations in the peripheral glandular epithelium of the prostate, resulting in squamous metaplasia. Using a panel of monoclonal and polyclonal cytokeratin antibodies on frozen tissue sections of control prostates, we were able to immunohistochemically distinguish between the normal secretory cells, which are positive for cytokeratin 18 as detected with the antibody RGE 53, and the scattered basal cells, which could be specifically stained by the antibody RCK 103. Cytokeratins indicating squamous differentiation, i.e., nos 4 and 13, recognised by the antibodies 6B10 and 1C7, respectively, were found in sporadic cells throughout the normal goat prostate. Profound changes in cytokeratin expression were observed in the metaplastic lesions as compared to control peripheral glandular tissue. In this respect three monoclonal antibodies are of special interest. RCK 103 is immunoreactive with resting and all stages of differentiating basal cells. Antibodies 1C7 and 6B10 strongly stain the squamous cells in the metaplastic lesions, with 1C7 staining all the squamous cells in the lesions except the basal cell layer, and 6B10 being immunoreactive with the same suprabasal cells or the more differentiated cells in the upper strata. As a result the number of cytokeratin 18-positive cells is drastically reduced upon metaplasia. The results indicate that the goat system can be used as a suitable model system to further test the applicability of immunohistochemical methods in meat inspection and toxicological pathology.
Subject(s)
Goat Diseases/pathology , Keratins/analysis , Prostate/pathology , Prostatic Neoplasms/veterinary , Animals , Antibodies, Monoclonal , Cross Reactions , Diethylstilbestrol/analogs & derivatives , Epithelium/chemistry , Epithelium/pathology , Frozen Sections , Goats , Hyperplasia , Immunoenzyme Techniques , Immunohistochemistry , Keratins/immunology , Male , Metaplasia , Prostate/chemistry , Prostatic Neoplasms/pathologyABSTRACT
A method has been developed for the demonstration of neutral and acidic glycoproteins in and for preparing autoradiographs of rat nasal glands embedded in JB-4 embedding kit.
