Microsphere Peptide-Based Immunoassay for the Detection of Recombinant Bovine Somatotropin in Injection Preparations.

The use of peptides in immunoassays can be favored over the use of the full protein when more cost effective or less toxic approaches are needed, or when access to the full protein is lacking. Due to restricted access to recombinant bovine somatotropin (rbST), a protein enhancing growth and lactating performances of livestock, which use has been banned in the EU, Canada and Australia (amongst others), we developed a peptide-based biorecognition assay on an imaging planar array analyzer. For this, we identified the rbST epitope that is responsible for binding to the rbST-targeting monoclonal antibody 4H12 (MAb 4H12) to be DLEEGILALMR.

Discrimination between the exogenous and endogenous origin of thiouracil in farm animals, the final chapter?

Thiouracil (2-thiouracil) is a thyreostatic compound that can be used as an illegal growth promoter. In bovine, porcine and other farm animals, low concentrations of thiouracil are detected in urine. There is much debate on which concentrations can be considered to originate from feed ('natural') and which concentrations are caused by the illegal administration of thiouracil for growth-promoting purposes.

Detection of methionine- and alanine-recombinant bovine somatotropins and their induced antibodies in serum and milk of cows suggests blood-milk barrier specificity for these compounds.

The elimination of recombinant bovine somatotropin (rbST) and its induced antibodies through milk of 2 formulations is studied to propose a control strategy for its use or abuse. Two dairy cows were treated with alanine-rbST (Ala-rbST), which is identical to endogenous bovine somatotropin, and ten dairy cows were treated with methionine-rbST (Met-rbST), which differs by 1 amino acid from endogenous bovine somatotropin. We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method able to measure rbST at a decision limit (CCα) of 0.

Determination and confirmation of selective estrogen receptor modulators (SERMs), anti-estrogens and aromatase inhibitors in bovine and porcine urine using UHPLC-MS/MS.

Selective estrogen receptor modulators (SERMs), anti-estrogens and aromatase inhibitors are prohibited in human sports doping. However, they also present a risk of being used illegally in animal husbandry for fattening purposes. A method was developed and validated using UHPLC-MS/MS for the determination and confirmation of SERMs, anti-estrogens and aromatase inhibiters in bovine and porcine urine.

A view on the analytical design of future risk based residue control.

The current laboratory network system in support of residue monitoring programmes within the EU formally started in the early 1990s. Since then, it has undergone a gentle evolution incorporating new techniques and methods for quality assurance and, in parallel to the extension of the European Union itself, was further extended. However, a paradigm shift from production-based to risk-based control now is foreseen.

Dietary supplement for energy and reduced appetite containing the β-agonist isopropyloctopamine leads to heart problems and hospitalisations.

In 2013 the Dutch authorities issued a warning against a dietary supplement that was linked to 11 reported adverse reactions, including heart problems and in one case even a cardiac arrest. In the UK a 20-year-old woman, said to have overdosed on this supplement, died. Since according to the label the product was a herbal mixture, initial LC-MS/MS analysis focused on the detection of plant toxins.

Calling Biomarkers in Milk Using a Protein Microarray on Your Smartphone.

Here we present the concept of a protein microarray-based fluorescence immunoassay for multiple biomarker detection in milk extracts by an ordinary smartphone. A multiplex immunoassay was designed on a microarray chip, having built-in positive and negative quality controls. After the immunoassay procedure, the 48 microspots were labelled with Quantum Dots (QD) depending on the protein biomarker levels in the sample.

Cellphone-based detection platform for rbST biomarker analysis in milk extracts using a microsphere fluorescence immunoassay.

Current contaminant and residue monitoring throughout the food chain is based on sampling, transport, administration, and analysis in specialized control laboratories. This is a highly inefficient and costly process since typically more than 99% of the samples are found to be compliant. On-site simplified prescreening may provide a scenario in which only samples that are suspect are transported and further processed.

Investigation of the presence of prednisolone in bovine urine.

Over the past two years low levels of prednisolone have been reported in bovine urine by a number of laboratories in European Union member states. Concentrations vary, but are reported to be below approximately 3 µg l(-1). Forty per cent of bovine urine samples from the Dutch national control plan had concentrations of prednisolone between 0.

Bioactivity screening and mass spectrometric confirmation for the detection of PPARδ agonists that increase type 1 muscle fibres.

Sensitive and robust bioassays able to detect nuclear receptor activation are very useful for veterinary and doping control, pharmaceutical industry and environmental scientists. Here, we used bioassays based on human leukemic monocyte lymphoma U937 and human liver hepatocellular carcinoma HepG2 cell lines to detect the ligand-induced activation of the peroxisome proliferator-activated receptor delta (PPARδ). Exposure of U937 cells to the PPARδ agonist GW501516 resulted in a marked increase in mRNA expression of the PPARδ target gene Angptl4 which was quantified by qRT-PCR analysis.

Selective androgen receptor modulators: in vitro and in vivo metabolism and analysis.

For future targeted screening in National Residue Control Programmes, the metabolism of seven SARMs, from the arylpropionamide and the quinolinone classes, was studied in vitro using S9 bovine liver enzymes. Metabolites were detected and identified with ultra-performance liquid chromatography (UPLC) coupled to time-of-flight mass spectrometry (ToF-MS) and triple quadrupole mass spectrometry (QqQ-MS). Several metabolites were identified and results were compared with literature data on metabolism using a human cell line.

Application of the revised EU criteria for the confirmation of anabolic steroids in meat using GC-MS.

The EU criteria for the confirmation of the presence of illegal compounds in biological matrices were recently revised. The old and the revised criteria were applied to relative ion intensities obtained for five anabolic steroids (methylboldenone, methyltestosterone, ethynylestradiol, beta-boldenone and beta-nortestosterone) in meat (cow, pig, turkey) and fish at concentrations ranging from 0.5 to 5.

Determination of acetyl gestagenic steroids in kidney fat by automated supercritical fluid extraction and liquid chromatography ion-trap mass spectrometry.

Acetyl gestagenic steroids are isolated from animal tissues such as bovine kidney fat by automated supercritical fluid extraction (SFE). After the addition of internal standards and sample pretreatment, the analytes are extracted from the matrix by supercritical CO2 and trapped directly in-line on alumina placed in the extraction vessel. The samples are analysed by liquid chromatography combined with ion-trap mass selective detection (LC-MSn).