Drug Testing and Analysis最新文献

This narrative review explores the concept of muscle memory, focusing on the physiological and biochemical mechanisms underlying information retention in skeletal muscle tissue as it relates to antidoping. The discussion encompasses the role of satellite cells (SCs) in myonuclei recruitment, resulting in increased myonuclear density and heightened muscle protein turnover. The myonuclear domain theory suggests that myonuclei acquired during hypertrophy may persist, contributing to enhanced muscle protein synthesis (MPS) and potential benefits of muscle memory. The impact of sustained training, protein intake, and resistance exercise on muscle memory, especially in elite athletes, is considered. The review also delves into the influence of anabolic androgenic steroids (AAS) on muscle tissue, highlighting their role in elevating the performance threshold and supporting recovery during intense training through increased muscle protein turnover rates. Additionally, genetic and epigenetic modifications, such as DNA methylation, are explored as potential contributors to muscle memory. The complex interplay of continuous training, AAS use, and genetic factors offers avenues for further research, especially in the context of antidoping efforts. The understanding of muscle memory has implications for maintaining performance gains and addressing ethical challenges in sports.

A patient was prescribed a new treatment, 40 mg furosemide. Her pharmacist mistakenly dispensed 40 mg gliclazide instead. After 3 weeks of treatment, the patient was found in a coma, was hospitalised and died after a week. Hair sample was collected during post-mortem examination and tested for gliclazide on three 2 cm sections, starting at the root end. Hair strands were decontaminated, segmented and incubated in the presence of diazepam-d₅, and a solid-liquid extraction has been performed. Finally, toxicological analyses were performed by UFLC Shimadzu Prominence - MS/MS Sciex 6500 QTRAP. Gliclazide was found on the proximal (238 pg/mg), median (77 pg/mg) and distal (69 pg/mg) segments. The concentration in the proximal segment was largely higher than in the other two, which demonstrates repeated intake of gliclazide by the patient during at least the last 2 months before death. The lower concentrations in the medial and distal segments, as well as a part of the concentration in the proximal segment, may be linked to external hair contamination. These could be due to either radial sweat diffusion, possibly occurring in the last week hospitalisation of the patient, or to biological fluids contamination during post-mortem examination. This case illustrates the opportunity to confirm slow and fatal chronic poisoning by gliclazide using hair analysis and shows the benefit of hair testing for the investigation of medical or dispensing errors.

Altrenogest is a synthetic progestin that suppresses reproductive behaviours and assists pregnancy maintenance in female horses. Two formulations are available, a 'weekly' intramuscular injection and a daily oral formulation. Altrenogest administration has returned positive swabs for steroids; consequently, using injectable altrenogest in racing mares is prohibited. Oral administration may be permitted in race mares if there is one clear day between dosing and racing. The only pharmacokinetic data available were generated from geldings. Therefore, to assist veterinarians and analysts in determining accurate dosing and detection intervals, pharmacokinetic analysis using mares is required. Blood samples were taken from 10 mares pretreatment to obtain baseline concentrations. Mares were administered altrenogest, either oral (PO; 0.044 mg/kg; daily for 15 days) or intramuscular (IM; 0.3 mg/kg; twice; Days 0 and 7). On the first and last treatment day, blood samples were taken at designated times post dosing. After a 3-week washout, mares received the alternative treatment with sampling repeated. At the initial dose, for IM administration mean (± SD) plasma altrenogest C_max was 18.0 ± 6.6 ng/mL at 7.9 ± 3.9 h compared with PO dosing 13.2 ± 5.8 ng/mL at 0.8 ± 0.8 h. Plasma C_max on the final day was significantly higher (p = 0.002 [IM]; p = 0.006 [PO]). At 24 h post final oral treatment, mean (± SD) plasma altrenogest was 1.0 ± 0.8 ng/mL and at 48 h were 0.65 ± 0.5 ng/mL. Plasma concentrations well exceeding this may indicate that the one clear day rule or dosage recommendations have not been adhered to.

Erythropoiesis-stimulating agents (ESAs) continue to be a significant threat to the integrity of human and equine sports. Besides conventional direct testing, monitoring the biomarkers associated with the effects of ESAs may provide a complementary approach via indirect detection to enhance doping control. In this study, we applied label-free proteomics to discover plasma protein biomarkers in Thoroughbred geldings after administration with a long-acting form of recombinant human erythropoietin (rhEPO), methoxy polyethylene glycol epoetin beta, Mircera. Increased haematocrit, haemoglobin and red blood cell (RBC) levels were evidenced as early as 4 days post-administration in all three horses to varying extents. Tryptic peptides were obtained from plasma samples and analysed by nanoflow ultra-high-performance liquid chromatography-high-resolution tandem mass spectrometry (nano-UHPLC-HRMSMS) using data-independent acquisition. Differential protein abundance analysis has shortlisted seven protein biomarker candidates that showed significant changes specifically after Mircera administration in the treated but not in the control geldings, which comprised downregulation of two proteins, haptoglobin (HP) and haemopexin (HPX), and upregulation of five proteins, transferrin receptor 1 (TFR1), phospholipid transfer protein (PLTP), tenascin C (TNC), vascular cell adhesion molecule 1 (VCAM1) and galectin 3 binding protein (LGALS3BP). Multivariate analysis of plasma proteome has allowed the classification of control and treated samples. This is the first report on the discovery of plasma protein biomarkers of rhEPO administration to geldings. The results lay a foundation for applications of protein biomarkers for controlling the misuse of ESAs.

Data-independent acquisition (DIA) methods employing a scanning quadrupole were recently described across multiple platforms. These strategies display remarkable performances in untargeted proteomics studies thanks to rapid duty cycles, leading to ultrashort liquid chromatography gradients while maintaining enough data points per peaks when coupled to fast-scanning mass analyzer. In this article, we perform the evaluation of three data acquisition strategies named diaPASEF,slicePASEF, and prmPASEF on a trapped ion mobility spectrometry quadrupole-time-of-flight (TIMS-Q-TOF) mass spectrometer for high-throughput doping control screening analyses. We report that slicePASEF outperforms diaPASEF and is almost as sensitive as prmPASEF in detecting humanized monoclonal antibodies for several weeks in equine plasma after administration. We observed that diaPASEF is still providing the best performances in untargeted proteomics studies employing high amounts of input materials, which is linked with the high complexity of slicePASEF data and current processing algorithms.

Positive identification and reporting of therapeutic substances intended for human consumption in race-day equine and canine samples is a controversial topic. While inadvertent environmental exposure is a potential cause for the presence of these substances in race-day samples, intentional use cannot be ruled out given their therapeutic benefits. Pregabalin is widely prescribed in Australia to treat epilepsy, anxiety, and neuropathic pain in humans; however, it is also increasingly used as a recreational drug. Metformin is commonly used to treat type 2 diabetes in humans. Both pregabalin and metformin have no routine use on racing animals and should not be present in race-day samples taken from healthy animals. They are prohibited substances under the Rules of Racing with no established screening limits. Although therapeutic levels for these substances have been established in humans, such information is not available for animals. Pregabalin and metformin are analytically challenging molecules, more so when they are extracted from biological matrices routinely screened for hundreds of other compounds simultaneously. A simple extraction, followed by a targeted Ultra High-Pressure Liquid Chromatography Orbitrap™ Mass Spectrometry method utilising a reverse-phase C18 column, is presented. This method is effective in screening for pregabalin and metformin, in addition to more than 150 other compounds of interest in equine and canine urines. The prevalence of pregabalin and metformin in race-day equine and canine urine samples in Western Australia was monitored using this method over 12 months. More than 4000 urine samples were screened, and four samples were confirmed positive for these substances.

The determination of serum concentrations of testosterone (T) and 4-androstenedione (A4) was implemented into the steroidal module of the Athlete Biological Passport in 2023. Monitoring T, A4, and the ratio of T/A4 in a longitudinal manner enables the detection of the misuse of low-dose T administrations especially in female athletes, whereas urinary markers of the steroid profile may not be influenced significantly. In contrast to the urinary steroid profile, knowledge on confounding factors regarding serum concentrations of T and A4 is yet comparably scarce, and corroborating exogenous sources of the target analytes by isotope ratio mass spectrometry (IRMS) is desirable. In a recent study, it was demonstrated that carbon isotope ratios (CIRs) of serum steroids can be determined if analyte concentrations permit. The therein-employed method utilized 2D-GC/IRMS, and only a limited number of potential endogenous reference compounds were available. The here-presented approach uses complementary analyte purification strategies, addressing previous limitations. A high-performance liquid chromatography cleanup was developed and fully validated for serum steroids in order to enable all doping control laboratories to potentially implement this method alongside existing protocols for urinary steroids. Besides the already-investigated endogenous steroids cholesterol, dehydroepiandrosterone sulfate, androsterone sulfate, and epiandrosterone sulfate, two additional steroids were included in the test menu, namely, pregnenolone sulfate and 5-androstene-3β,17β-diol sulfate. Serum steroid concentrations down to 25 ng/mL were found to allow robust CIR determinations, and a reference population encompassing 124 male and female athlete samples was investigated to enable the calculation of population-based thresholds for all relevant steroid combinations.