Detection of sgRNA via SHERLOCK as Potential CRISPR Related Gene Doping Control Strategy.

Apprehensions about gene doping have grown consistently due to advancements in gene engineering techniques, particularly with the emergence of clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas)-based tools. These tools not only provide unprecedented possibilities for illicit performance enhancement by athletes but also offer new avenues for the detection of gene doping through biosensing of nucleic acids. Hence, pursuing on a previous study, an analytical method based on reverse transcriptase-recombinase polymerase amplification (RT-RPA) and subsequent qualitative nucleic acid detection by means of Specific High Sensitive Enzymatic Reporter UnLOCKing (SHERLOCK) was optimized for the direct detection of sgRNA associated with Streptococcus pyogenes in serum. Detection device, assay parameters, and sample handling were adjusted, to overcome previously determined assay limitations. The conducted method characterization confirmed the methods' specificity and increased detection sensitivity from 100 pM to 1 fM sgRNA in 100 µL of serum. Furthermore, reanalysis of in vivo mouse administration samples collected in a previous proof-of-concept study was conducted with successful identification of sgRNA in all anticipated postadministration samples within the 24-h collection period. Those findings support the applicability of the refined analytical procedure for the detection of illegal doping attempts via ribonucleoprotein-based CRISPR/Cas application through sgRNA identification, offering a new potential doping control strategy for CRISPR related gene doping.

Investigations into the concentration and metabolite profiles of stanozolol and LGD-4033 in blood plasma and seminal fluid using liquid chromatography high-resolution mass spectrometry.

Potential scenarios as to the origin of minute amounts of banned substances detected in doping control samples have been a much-discussed problem in anti-doping analysis in recent years. One such debated scenario has been the contamination of female athletes' urine with ejaculate containing doping agents and/or their metabolites. The aim of this work was to obtain complementary information on whether relevant concentration ranges of doping substances are excreted into the ejaculate and which metabolites can be detected in the seminal fluid (sf) and corresponding blood plasma (bp) samples. A method was established to study the concentration and metabolite profiles of stanozolol and LGD-4033-substances listed under anabolic substances (S1) on the World Anti-Doping Agency's Prohibited List-in bp and sf using liquid chromatography high-resolution mass spectrometry (LC-HRMS). For sf and bp, methods for detecting minute amounts of these substances were developed and tested for specificity, recovery, linearity, precision, and reliability. Subsequently, sf and bp samples from an animal administration study, where a boar orally received stanozolol at 0.33 mg/kg and LGD-4033 at 0.11 mg/kg, were measured. The developed assays proved appropriate for the detection of the target substances in both matrices with detection limits between 10 and 40 pg/mL for the unmetabolized drugs in sf and bp, allowing to estimate the concentration of stanozolol in bp (0.02-0.40 ng/mL) and in sf (0.01-0.25 ng/mL) as well as of LGD-4033 in bp (0.21-2.00 ng/mL) and in sf (0.03-0.68 ng/mL) post-administration. In addition, metabolites resulting from different metabolic pathways were identified in sf and bp, with sf resembling a composite of the metabolic profile of bp and urine.

High neutralizing potency of swine glyco-humanized polyclonal antibodies against SARS-CoV-2.

Heterologous polyclonal antibodies might represent an alternative to the use of convalescent plasma or monoclonal antibodies (mAbs) in coronavirus disease (COVID-19) by targeting multiple antigen epitopes. However, heterologous antibodies trigger human natural xenogeneic antibody responses particularly directed against animal-type carbohydrates, mainly the N-glycolyl form of the neuraminic acid (Neu5Gc) and the α1,3-galactose, potentially leading to serum sickness or allergy. Here, we immunized cytidine monophosphate-N-acetylneuraminic acid hydroxylase and α1,3-galactosyl-transferase (GGTA1) double KO pigs with the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor binding domain to produce glyco-humanized polyclonal neutralizing antibodies lacking Neu5Gc and α1,3-galactose epitopes. Animals rapidly developed a hyperimmune response with anti-SARS-CoV-2 end-titers binding dilutions over one to a million and end-titers neutralizing dilutions of 1:10 000. The IgG fraction purified and formulated following clinical Good Manufacturing Practices, named XAV-19, neutralized spike/angiotensin converting enzyme-2 interaction at a concentration <1 µg/mL, and inhibited infection of human cells by SARS-CoV-2 in cytopathic assays. We also found that pig GH-pAb Fc domains fail to interact with human Fc receptors, thereby avoiding macrophage-dependent exacerbated inflammatory responses and a possible antibody-dependent enhancement. These data and the accumulating safety advantages of using GH-pAbs in humans warrant clinical assessment of XAV-19 against COVID-19.

How to detect CRISPR with CRISPR - employing SHERLOCK for doping control purposes.

The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) tool kit constitutes one of today's most frequently used gene editing techniques. Editing of virtually any DNA sequence can be realised, due to the quickly progressing research into different Cas effectors and their ever-expanding range of targets. Moreover, the simplicity and cost-effectiveness of those CRISPR tools can, unfortunately, also facilitate the illicit utilisation of CRISPR/Cas in order to achieve performance enhancements amongst athletes. Consequently, there is an urgent need for the direct detection of illegally applied CRISPR/Cas methods in doping control samples, for which a promising strategy is presented herein employing Specific High Sensitive Enzymatic Reporter UnLOCKing (SHERLOCK) for targeted nucleic acid detection. An analytical method was developed that enables the detection of sgRNA associated with Cas9 from Streptococcus pyogenes (SpCas9) in serum samples by means of reverse transcriptase-recombinase polymerase amplification (RT-RPA) and subsequent qualitative nucleic acid detection via SHERLOCK in combination with a complementary gel-based screening procedure in order to uncover doping attempts with lipid mediated CRISPR ribonucleoprotein (RNP) complexes. Initial qualitative method characterisation confirmed the specificity of both procedures and established a detection sensitivity of 10 nM uncomplexed target sequence and 100 pM sgRNA in the form of RNP complexes. Furthermore, a proof-of-concept in vivo adimistration study simulating a hypothetical gene doping scenario employing a mouse model revealed a detection window of 8 h after intravenous injection, supporting the principal applicability of the test strategy to authentic doping control samples in the future.

Comprehensive insights into the formation of metabolites of the ghrelin mimetics capromorelin, macimorelin and tabimorelin as potential markers for doping control purposes.

Analytical methods to determine the potential misuse of the ghrelin mimetics capromorelin (CP-424,391), macimorelin (macrilen, EP-01572) and tabimorelin (NN703) in sports were developed. Therefore, different extraction strategies, i.e. solid-phase extraction, protein precipitation, as well as a "dilute-and-inject" approach, from urine and EDTA-plasma were assessed and comprehensive in vitro/in vivo experiments were conducted, enabling the identification of reliable target analytes by means of high resolution mass spectrometry. The drugs' biotransformation led to the preliminary identification of 51 metabolites of capromorelin, 12 metabolites of macimorelin and 13 metabolites of tabimorelin. Seven major metabolites detected in rat urine samples collected post-administration of 0.5-1.0 mg of a single oral dose underwent in-depth characterization, facilitating their implementation into future confirmatory test methods. In particular, two macimorelin metabolites exhibiting considerable abundances in post-administration rat urine samples were detected, which might contribute to an improved sensitivity, specificity, and detection window in case of human sports drug testing programs. Further, the intact drugs were implemented into World Anti-Doping Agency-compliant initial testing (limits of detection 0.02-0.60 ng/ml) and confirmation procedures (limits of identification 0.18-0.89 ng/ml) for human urine and blood matrices. The obtained results allow extension of the test spectrum of doping agents in multitarget screening assays for growth hormone-releasing factors from human urine.

First Steps toward Uncovering Gene Doping with CRISPR/Cas by Identifying SpCas9 in Plasma via HPLC-HRMS/MS.

The discovery of the clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) system as a programmable, RNA-guided endonuclease has revolutionized the utilization of gene technology. Because it enables the precise modification of any desired DNA sequence and surpasses all hitherto existing alternatives for gene editing in many ways, it is one of the most frequently used tools for genome editing. However, these advantages also potentially facilitate the illicit use of the CRISPR/Cas system in order to achieve performance-enhancing effects in sporting competitions. This abuse is classified as gene doping, which is banned in sports according to the Prohibited List of the World Anti-Doping Agency (WADA). Therefore, there is a pressing need for an adequate analytical method to detect the misuse of the CRISPR/Cas system by athletes. Hence, the first aim accomplished with this study was the identification of the exogenous protein Cas9 from the bacterium Streptococcus pyogenes (SpCas9) in plasma samples by means of a bottom-up analytical approach via immunoaffinity purification, tryptic digestion, and subsequent detection by HPLC-HRMS/MS. A qualitative method validation was conducted with three specific peptides allowing for a limit of detection of 25 ng/mL. Additionally, it was shown that the developed method is also applicable to the detection of (illicit) gene regulation through the identification of catalytically inactive Cas9. A proof-of-concept administration study employing an in vivo mouse model revealed a detection window of SpCas9 for up to 8 h post administration, confirming the suitability of the test strategy for the analysis of authentic doping control samples.

Analysis of endogenous steroids in urine by means of multi-immunoaffinity chromatography and isotope ratio mass spectrometry for sports drug testing.

Detecting the administration of naturally occurring but synthetically derived steroids (e.g., testosterone) in routine doping controls is particularly laborious and time-consuming. Carbon isotope signatures determined by isotope ratio mass spectrometry (IRMS) have been established as the method of choice to generate confirmatory evidence in case of suspicious or atypical findings in steroid profile analyses; however, IRMS measurements require sophisticated sample preparation methods employing up to two high-performance liquid chromatography (HPLC) purification steps. Here, an alternative sample preparation approach is presented. Immunoaffinity chromatography (IAC) was employed to reduce the batch analysis time by omitting the time-consuming HPLC purification steps, while pre- and post-IAC sample handling followed published protocols. IAC exploits specific antibody-immunogen interactions, and the option of combining three immunoaffinity gels containing specific antibodies for testosterone, pregnanediol, and 11-ketoetiocholanolone into a multi-immunoaffinity sample preparation approach was assessed. Due to cross reactivities, also etiocholanolone, androsterone, 5ß-androstanediol, and 5α-androstanediol were co-extracted and included in the testing protocol. The method was validated by determining precision, recovery, and carry over, and performing linear mixing models. IAC was found to be applicable to the determination of carbon isotope ratios in doping controls and the approach allowed for an accelerated sample preparation. Graphical abstract.

Immunisation - Choice of host, adjuvants and boosting schedules with emphasis on polyclonal antibody production.

Polyclonal antibodies are frequently used as immunodiagnostic tools in fundamental research. They are also used for routine diagnostic purposes in human and veterinary medicine and for quality control procedures in the food-processing industry. The antibody is a major component of the detection system. It binds with the molecule to be identified. This conjugate is subsequently revealed by means of binding the antibody with a radio-isotope, a fluorescent substance, an enzyme inducing a color change, or a biosensor based analytical system. Polyclonal antibodies are also used for treatment purposes in various pathologies. They might have immunomodulating or anti-inflammatory properties. Snake venom, rabies and tetanus antisera are examples of a therapeutic application; immunosuppressive antithymocyte serum used in order to avoid rejection in organ transplantation is another example from human medicine. These therapeutic aids need hyperimmunisation of animals. Since these are subject to a certain number of interventions such as injections and blood samplings, animal welfare prescriptions have to be taken into account. The optimisation of the immunisation protocol allows for reducing the numbers of animals used as well as reducing stress and pain while obtaining high quality antibodies. This article describes the critical steps in polyclonal antibody production with a particular focus on the choice of the animal species, the age of the subjects, the injection protocol and the sampling times.

Accurate Control of 17ß-Estradiol Long-Term Release Increases Reliability and Reproducibility of Preclinical Animal Studies.

Estrogens are the subject of intensive researches aiming to elucidate their mechanism of action on the various tissues they target and especially on mammary gland and breast cancer. The use of ready-to-use slow releasing devices to administer steroids, especially estrogens, to small experimental animals remains the method of choice in terms of animal well-being and of safety for both the researcher and the animal. In this study, we evaluated and compared, in vitro and in vivo, the release kinetic of estradiol (E2) over sixty days from two different slow-releasing systems: the matrix pellet (MP) and the reservoir implant (RI). We compared the impact of these systems in three E2-sensitive mouse models : mammary gland development, human MCF7 adenocarcinoma xenograft and mouse melanoma progression. The real amount of E2 that is released from both types of devices could differ from manufacturer specifications due to inadequate release for MP and initial burst effect for RI. Compared to MP, the interindividual variability was reduced with RI thanks to a superior control of the E2 release. Depending on the dose-dependent sensitivity of the physiological or pathological readout studied, this could lead to an improvement of the statistical power of in vivo experiments and thus to a reduction of the required animal number. Altogether, our data draw attention on the importance to adequately select the slow-releasing device that is the most appropriated to a specific experiment to better fulfill the 3Rs rule (Replacement, Reduction, Refinement) related to animal welfare and protection.

Carbon isotope ratios of endogenous steroids in Belgian Blue and Holstein cattle: Method development, reference population studies and application to steroid misuse control.

RATIONALE: The misuse of growth promoters in livestock and breeding animals is prohibited according to the laws of the European Union. Among these growth promoters, the detection of endogenous steroids like testosterone, estradiol or progesterone remains especially challenging as concentration-based urinary thresholds may not provide conclusive results due to large inter-individual variations. In addition to the detection of intact steroid esters in blood or hair, carbon isotope ratio (CIR) determination of urinary steroids has commonly been the method of choice. METHODS: A comprehensive sample clean-up procedure was developed and validated, which enables for the first time simultaneous CIR measurements of testosterone metabolites (17α-hydroxyandrost-4-en-3-one, 3α-hydroxy-5ß-androstan-17-one and 5α-androstane-3ß,17α-diol), the estradiol metabolite 17α-estradiol (ESTR) and the progesterone metabolite 5ß-pregnane-3α,20α-diol (PD) from a single urine specimen. As endogenous reference compounds 3ß-hydroxyandrost-5-en-17-one and 5-androstene-3ß,17α-diol (5EN) were chosen. The method was validated by means of linear mixing models and a reference population encompassing n = 53 Belgian Blue and Holstein cattle was investigated to enable the calculation of population-based Δ13 C thresholds. RESULTS: The combined measurement uncertainty determined for the Δ13 C-values of all steroids under investigation was found to be <0.8 ‰. Within the reference population studies, 5EN was demonstrated to be the most promising endogenous reference compound resulting in comparably low Δ-values and accompanying thresholds. For PD, a surprisingly high number of samples (n = 9) yielded significantly 13 C-depleted values and ESTR was only detectable in n = 13 samples. Proof-of-concept was accomplished by investigating two post-administration samples. CONCLUSIONS: This first comprehensive investigation on the CIRs of endogenous urinary steroids demonstrated once more the potential of isotope ratios in aiding discrimination between endogenously produced and exogenously administered steroids. By means of the reference population-derived CIRs, it is possible to apply cattle-specific thresholds to differentiate between treated and non-treated animals.

Pharmacokinetic and urinary profiling reveals the prednisolone/cortisol ratio as a valid biomarker for prednisolone administration.

BACKGROUND: In Europe, synthetic corticosteroids are not allowed in animal breeding for growth-promoting purposes. Nevertheless, a high prevalence of non-compliant urine samples was recently reported for prednisolone, however, without any indication of unauthorized use. Within this context, 20ß-dihydroprednisolone and the prednisolone/cortisol ratio have been suggested as potential tools to discriminate between exogenous and endogenous urinary prednisolone. In this study, the validity of these strategies was verified by investigating the plasma pharmacokinetic and urinary excretion profiles of relevant glucocorticoids in bovines, subjected to exogenous prednisolone treatment or tetracosactide hexaacetate administration to induce endogenous prednisolone formation. Bovine urine and plasma samples were analysed by liquid chromatography and mass spectrometry. RESULTS: Based on the plasma pharmacokinetics and urinary profiles, 20ß-dihydroprednisolone was confirmed as the main prednisolone-derived metabolite, being detected in the biological fluids of all 12 bovines (plasma AUC0-inf of 121 h µg L-1 and urinary concentration > 0.695 µg L-1). However, this metabolite enclosed no potential as discriminative marker as no significant concentration differences were observed upon exogenous prednisolone treatment or tetracosactide hexaacetate administration under all experimental conditions. As a second marker tool, the prednisolone/cortisol ratios were assessed along the various treatments, taking into account that endogenous prednisolone formation involves the hypothalamic-pituitary-adrenal axis and is associated with an increased cortisol secretion. Significantly lower ratios were observed in case of endogenous prednisolone formation (i.e. ratios ranging from 0.00379 to 0.129) compared to the exogenous prednisolone treatment (i.e. ratios ranging from 0.0603 to 36.9). On the basis of these findings, a discriminative threshold of 0.260 was proposed, which allowed classification of urine samples according to prednisolone origin with a sensitivity of 94.2% and specificity of 99.0%. CONCLUSION: The prednisolone/cortisol ratio was affirmed as an expedient strategy to discriminate between endogenous and exogenous prednisolone in urine. Although the suggested threshold value was associated with high specificity and sensitivity, a large-scale study with varying experimental conditions is designated to optimize this value.

Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS.

The use of growth hormone-releasing hormones (GHRHs) is prohibited in sports according to the regulations of the World Anti-Doping Agency (WADA). The aim of the present study was to develop a method for the simultaneous detection of four different GHRHs and respective metabolites from human plasma by means of immunoaffinity purification and subsequent nano-ultrahigh performance liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry. The target analytes included Geref (Sermorelin), CJC-1293, CJC-1295, and Egrifta (Tesamorelin) as well as two metabolites of Geref and CJC-1293, which were captured from plasma samples using a polyclonal GHRH antibody in concert with protein A/G monolithic MSIA™ D.A.R.T.'S® (Disposable Automation Research Tips) prior to separation and detection. The method was fully validated and found to be fit for purpose considering the parameters specificity, linearity, recovery (19-37%), lower limit of detection (<50 pg/mL), imprecision (<20%), and ion suppression/enhancement effects. The analytes' stability and metabolism were elucidated using in vitro and in vivo approaches. EDTA blood samples were collected from rats 2, 4, and 8 h after intravenous administration of GHRH (one compound per test animal). All intact substances were detected for at least 4 h but no anticipated metabolite was confirmed in laboratory rodents' samples; conversely, a Geref metabolite (GHRH3-29) was found in a human plasma sample collected after subcutaneous injection of the drug to a healthy male volunteer. The obtained results demonstrate that GHRHs are successfully detected in plasma using an immunoaffinity-mass spectrometry-based method, which can be applied to sports drug testing samples. Further studies are however required and warranted to account for potential species-related differences in metabolism and elimination of the target analytes.

A flow-cytometry-based method for detecting simultaneously five allergens in a complex food matrix.

To avoid carry-over contamination with allergens, food manufacturers implement quality control strategies relying primarily on detection of allergenic proteins by ELISA. Although sensitive and specific, this method allowed detection of only one allergen per analysis and effective control policies were thus based on multiplying the number of tests done in order to cover the whole range of allergens. We present in this work an immunoassay for the simultaneous detection of milk, egg, peanut, mustard and crustaceans in cookies samples. The method was based on a combination of flow cytometry with competitive ELISA where microbeads were used as sorbent surface. The test was able to detect the presence of the five allergens with median inhibitory concentrations (IC50) ranging from 2.5 to 15 mg/kg according to the allergen to be detected. The lowest concentrations of contaminants inducing a significant difference of signal between non-contaminated controls and test samples were 2 mg/kg of peanut, 5 mg/kg of crustaceans, 5 mg/kg of milk, 5 mg/kg of mustard and 10 mg/kg of egg. Assay sensitivity was influenced by the concentration of primary antibodies added to the sample extract for the competition and by the concentration of allergenic proteins bound to the surface of the microbeads.

Determination of Synacthen(®) in dried blood spots for doping control analysis using liquid chromatography tandem mass spectrometry.

Dried blood spot (DBS) sampling, a technique used for taking whole blood samples dried on a filter paper, was initially reported in 1963 by Robert Guthrie. While the diagnostic analysis of metabolic disorders in newborns was the focus of investigations at that time, the number of established applications for preclinical drug development, toxicological studies, and therapeutic drug monitoring increased enormously in the last decades. As a consequence of speed, simplicity, and minimal invasiveness, DBS recommends itself as the preferential technique in sports drug testing. The present approach highlights for the first time the development of a screening assay for the analysis of the synthetic human adrenocorticotropic hormone tetracosactide hexaacetate (Synacthen(®)) in DBS using liquid chromatography tandem mass spectrometry. Highly purified sample extracts were obtained by an advanced sample preparation procedure including the addition of an internal standard (d8-tetracosactide) and immunoaffinity purification. The method's overall recovery was 27.6 %, and the assay's imprecision was calculated between 8.1 and 17.9 % for intraday and 12.9 to 20.5 % for interday measurements. Stability of the synthetic peptide in DBS was shown for at least 10 days at room temperature and presents a major benefit, since a rapid degradation in conventionally applied matrices such as urine or plasma is well known. With a limit of detection of 50 pg/mL, a detection window of several hours is expected considering reported steady-state plasma levels of 300 pg/mL after intramuscular application of Synacthen(®) Depot (1 mg). The analysis of authentic DBS samples within the scope of an administration study with 250 µg Synacthen(®) (short stimulation test) demonstrated the great potential of the developed assay to simplify the analysis of Synacthen(®) for doping control purposes.

Evolving to the optoelectronic mouse for phycotoxin analysis in shellfish.

Despite ethical and technical concerns, the in vivo method, or more commonly referred to mouse bioassay (MBA), is employed globally as a reference method for phycotoxin analysis in shellfish. This is particularly the case for paralytic shellfish poisoning (PSP) and emerging toxin monitoring. A high-performance liquid chromatography method (HPLC-FLD) has been developed for PSP toxin analysis, but due to difficulties and limitations in the method, this procedure has not been fully implemented as a replacement. Detection of the diarrhetic shellfish poisoning (DSP) toxins has moved towards LC-mass spectrometry (MS) analysis, whereas the analysis of the amnesic shellfish poisoning (ASP) toxin domoic acid is performed by HPLC. Although alternative methods of detection to the MBA have been described, each procedure is specific for a particular toxin and its analogues, with each group of toxins requiring separate analysis utilising different extraction procedures and analytical equipment. In addition, consideration towards the detection of unregulated and emerging toxins on the replacement of the MBA must be given. The ideal scenario for the monitoring of phycotoxins in shellfish and seafood would be to evolve to multiple toxin detection on a single bioanalytical sensing platform, i.e. 'an artificial mouse'. Immunologically based techniques and in particular surface plasmon resonance technology have been shown as a highly promising bioanalytical tool offering rapid, real-time detection requiring minimal quantities of toxin standards. A Biacore Q and a prototype multiplex SPR biosensor have been evaluated for their ability to be fit for purpose for the simultaneous detection of key regulated phycotoxin groups and the emerging toxin palytoxin. Deemed more applicable due to the separate flow channels, the prototype performance for domoic acid, okadaic acid, saxitoxin, and palytoxin calibration curves in shellfish achieved detection limits (IC20) of 4,000, 36, 144 and 46 µg/kg of mussel, respectively. A one-step extraction procedure demonstrated recoveries greater than 80% for all toxins. For validation of the method at the 95% confidence limit, the decision limits (CCα) determined from an extracted matrix curve were calculated to be 450, 36 and 24 µg/kg, and the detection capability (CCß) as a screening method is ≤10 mg/kg, ≤160 µg/kg and ≤400 µg/kg for domoic acid, okadaic acid and saxitoxin, respectively.

Development and validation of a rapid multiplex ELISA for pyrrolizidine alkaloids and their N-oxides in honey and feed.

Pyrrolizidine alkaloids (PAs) are a group of plant secondary metabolites with carcinogenic and hepatotoxic properties. When PA-producing plants contaminate crops, toxins can be transferred through the food chain and cause illness in humans and animals, most notably hepatic veno-occlusive disease. Honey has been identified as a direct risk of human exposure. The European Food Safety Authority has recently identified four groups of PAs that are of particular importance for food and feed: senecionine-type, lycopsamine-type, heliotrine-type and monocrotaline-type. Liquid or gas chromatography methods are currently used to detect PAs but there are no rapid screening assays available commercially. Therefore, the aim of this study was to develop a rapid multiplex ELISA test for the representatives of three groups of alkaloids (senecionine, lycopsamine and heliotrine types) that would be used as a risk-management tool for the screening of these toxic compounds in food and feed. The method was validated for honey and feed matrices and was demonstrated to have a detection capability less than 25 µg/kg for jacobine, lycopsamine, heliotrine and senecionine. The zinc reduction step introduced to the extraction procedure allows for the additional detection of the presence of N-oxides of PAs. This first multiplex immunoassay for PA detection with N-oxide reduction can be used for the simultaneous screening of 21 samples for >12 PA analytes. Honey samples (n = 146) from various origins were analysed for PA determination. Six samples were determined to contain measurable PAs >25 µg/kg by ELISA which correlated to >10 µg/kg by LC-MS/MS.

Liquid chromatography-high resolution/ high accuracy (tandem) mass spectrometry-based identification of in vivo generated metabolites of the selective androgen receptor modulator ACP-105 for doping control purposes.

Selective androgen receptor modulators (SARMs) represent an emerging class of therapeutics which have been prohibited in sport as anabolic agents according to the regulations of the World Anti-Doping Agency (WADA) since 2008. Within the past three years, numerous adverse analytical findings with SARMs in routine doping control samples have been reported despite missing clinical approval of these substances. Hence, preventive doping research concerning the metabolism and elimination of new therapeutic entities of the class of SARMs are vital for efficient and timely sports drug testing programs as banned compounds are most efficiently screened when viable targets (for example, characteristic metabolites) are identified. In the present study, the metabolism of ACP-105, a novel SARM drug candidate, was studied in vivo in rats. Following oral administration, urine samples were collected over a period of seven days and analyzed for metabolic products by Liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry. Samples were subjected to enzymatic hydrolysis prior to liquid-liquid extraction and a total of seven major phase-I metabolites were detected, three of which were attributed to monohydroxylated and four to bishydroxylated ACP-105. The hydroxylation sites were assigned by means of diagnostic product ions and respective dissociation pathways of the analytes following positive or negative ionization and collisional activation as well as selective chemical derivatization. The identified metabolites were used as target compounds to investigate their traceability in a rat elimination urine samples study and monohydroxylated and bishydroxylated species were detectable for up to four and six days post-administration, respectively.

Immunoaffinity purification of peptide hormones prior to liquid chromatography-mass spectrometry in doping controls.

For most peptide hormones prohibited in elite sports the concentrations in plasma or urine are very low (pg/mL). Accordingly, hyphenated purification and enrichment steps prior to mass spectrometric detection are required to obtain sufficient doping control assays. Immunoaffinity purification in combination with nano-scale liquid chromatography coupled to high resolution/high accuracy mass spectrometry was found to have the potential of providing the necessary sensitivity and unambiguous specificity to produce reliable results. With the presented methodology 12 prohibited peptides (porcine insulin, Novolog, Apidra, Lantus DesB30-32 metabolite, Humalog and human insulin, Synacthen (synthetic ACTH analogue), luteinizing hormone-releasing hormone (LH-RH), growth hormone releasing hormone (GH-RH(1-29)) and CJC-1295 (GH-RH analogue), LongR(3)-IGF-1 and IFG-1) were simultaneously purified from plasma/serum or urine. With limits of detection for each target compound ranging in the low pg/mL level (urine), the method enables the determination of urinary peptides at physiologically relevant concentrations. For each class of peptides an appropriate antibody and a respective internal standard was implemented ensuring robust analysis conditions. Due to the fast and simple sample preparation procedure (∼25 samples per day) and the fact that all materials are commercial available, the implementation of the methodology to laboratories from other analytical fields (forensics, pharmacokinetic sciences, etc.) is enabled.

Screening methods and recent developments in the detection of anticoccidials.

This article presents a review of the current trends in the analysis of coccidiostats in various matrices, focusing principally on screening and rapid methods. Coccidiosis is an infectious disease having a high negative impact on the animal industry. Drugs are therefore necessary to prevent and/or to combat this disease. However, it is also of crucial importance that these veterinary drugs do not enter the human food chain. European legislation has therefore established the boundaries for the use of coccidiosats and has also addressed the unavoidable problem of cross-contamination of the feed, mainly caused by the use of the same production lines. Consequently there is a need for analytical methods and/or analytical strategies for the monitoring and control of the residues of anticoccidials, both in feed and in the resulting matrices for human consumption. In the frame of the European collaborative project CONffIDENCE, such attempts to establish the required analytical tools were made, which required beforehand a review of the state of the art in this domain. Aiming at this objective, in this review we consider the most interesting publications since 2000. In essence, both a rapid approach with mainly immunoassays and chromatographic methods were developed. To date, the obstacle to routine use of the first approach has been its inability to detect more than two compounds simultaneously, but recent developments in flow cytometry have made it possible to detect six coccidiostats at once. On the other hand, an increasingly popular approach for detecting multiple coccidiostats simultaneously is liquid chromatography coupled with tandem mass spectrometry. There remains a need to adapt these analytical methods to legislative requirements.

Effect-based proteomic detection of growth promoter abuse.

Unregulated growth promoter use in food-producing animals is an issue of concern both from food safety and animal welfare perspectives. However, the monitoring of such practices is analytically challenging due to the concerted actions of users to evade detection. Techniques based on the monitoring of biological responses to exogenous administrations have been proposed as more sensitive methods to identify treated animals. This study has, for the first time, profiled plasma proteome responses in bovine animals to treatment with nortestosterone decanoate and 17ß-oestradiol benzoate, followed by dexamethasone administration. Two-dimensional fluorescence differential in-gel electrophoresis analysis revealed a series of hepatic and acute-phase proteins within plasma whose levels were up- or down-regulated within phases of the treatment regime. Surface plasmon resonance (SPR) immuno-assays were developed to quantify responses of identified protein markers during the experimental treatment study with a view to developing methods which can be used as screening tools for growth promoter abuse detection. SPR analysis demonstrated the potential for plasma proteins to be used as indicative measures of growth promoter administrations and concludes that the sensitivity and robustness of any detection approach based on plasma proteome analysis would benefit from examination of a range of proteins representative of diverse biological processes rather being reliant on specific individual markers.