Development and validation of an enzyme-linked immunosorbent assay for the detection of circulating antibodies raised against growth hormone as a consequence of rbST treatment in cows.

The recombinant bovine growth hormone (rbST) is used to increase lactating performances of dairy cows. Administration of rbST is banned in the European Union; nevertheless, its use is probable. Until now, efficient analytical strategies to detect such practice are based on the direct detection by mass spectrometry of the presence of rbST in biological fluids, which suits for confirmatory purposes.

Criteria to distinguish between natural situations and illegal use of boldenone, boldenone esters and boldione in cattle 1. Metabolite profiles of boldenone, boldenone esters and boldione in cattle urine.

Boldenone is an androgenic steroid that improves the growth and food conversion in food producing animals. In most countries worldwide, this anabolic steroid is forbidden for meat production. Until recently, the control of its illegal use was based either on 17beta-boldenone or 17alpha-boldenone (its main metabolite in cattle) identification in edible tissues, hair, faeces or urine.

Endogenous nandrolone metabolites in human urine. Two-year monitoring of male professional soccer players.

19-Norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) are the two main indicators used to prove the illegal use of nandrolone by humans. Recent studies showed that 19-NA and 19-NE can be endogenously produced in some individuals. The mediated cases observed over the last three years generated some questions about the appropriateness of the official International Olympic Committee cutoff level, which is 2 ng/mL of 19-NA in male urine samples.

Endogenous nandrolone metabolites in human urine: preliminary results to discriminate between endogenous and exogenous origin.

When administered to human subjects, nandrolone is metabolized into two main products, 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE). Recent studies demonstrated the endogenous production of these compounds in man at concentrations very close to the threshold of the International Olympic Committee (IOC), i.e.