Risk of unintentional antidoping rule violations by consumption of hemp products.

Consumption of hemp products is continuously growing, with an expanding scope of applications. Suppliers operate through different distribution channels, but the Internet is a major retail platform. Hemp products are prepared from cannabis plants and, therefore, might contain a variety of different natural cannabinoids. According to the regulations of the World Anti-Doping Agency, all natural and synthetic cannabinoids are prohibited in-competition, with the explicit exemption of cannabidiol. Therefore, an investigation of 23 hemp products for the presence of cannabinoids was performed to determine the likelihood of unintentional violations of anti-doping regulations. An assay for the detection of 16 cannabinoids in nutritional supplements was developed and validated. The sample preparation consisted of QuEChERS extraction, trimethylsilylation, and analysis by gas chromatography/tandem mass spectrometry. All 23 commercially available hemp products were analyzed, and assay characteristics such as selectivity, limit of detection, limit of identification, limit of quantification, linearity, imprecision, recovery, and accuracy were determined. Twenty of 23 hemp products included a variety of cannabinoids at, occasionally, substantial concentrations, with four products covering the entire spectrum of tested cannabinoids. An ethics committee-approved single-dose administration study was conducted with the commercially available hemp products, investigating the presence of 16 cannabinoids in urine collected pre- and post-consumption. Variable patterns of cannabinoids or their metabolites in urine were observed. In 30% of the urine samples collected 8 h after ingestion, the presence of a prohibited cannabinoid would have resulted in an unintentional violation of anti-doping regulations.

A Drosophila model to study retinitis pigmentosa pathology associated with mutations in the core splicing factor Prp8.

Retinitis pigmentosa (RP) represents genetically heterogeneous and clinically variable disease characterized by progressive degeneration of photoreceptors resulting in a gradual loss of vision. The autosomal dominant RP type 13 (RP13) has been linked to the malfunction of PRPF8, an essential component of the spliceosome. Over 20 different RP-associated PRPF8 mutations have been identified in human patients. However, the cellular and molecular consequences of their expression in vivo in specific tissue contexts remain largely unknown. Here, we establish a Drosophila melanogaster model for RP13 by introducing the nine distinct RP mutations into the fly PRPF8 ortholog prp8 and express the mutant proteins in precise spatiotemporal patterns using the Gal4/UAS system. We show that all nine RP-Prp8 mutant proteins negatively impact developmental timing, albeit to a different extent, when expressed in the endocrine cells producing the primary insect moulting hormone. In the developing eye primordium, uncommitted epithelial precursors rather than differentiated photoreceptors appeared sensitive to Prp8 malfunction. Expression of the two most pathogenic variants, Prp8S>F and Prp8H>R, induced apoptosis causing alterations to the adult eye morphology. The affected tissue mounted stress and cytoprotective responses, while genetic programs underlying neuronal function were attenuated. Importantly, the penetrance and expressivity increased under prp8 heterozygosity. In contrast, blocking apoptosis alleviated cell loss but not the redox imbalance. Remarkably, the pathogenicity of the RP-Prp8 mutations in Drosophila correlates with the severity of clinical phenotypes in patients carrying the equivalent mutations, highlighting the suitability of the Drosophila model for in-depth functional studies of the mechanisms underlying RP13 etiology.This article has an associated First Person interview with the first author of the paper.

Case Study: Atypical δ13 C values of urinary norandrosterone.

Isotope ratio mass spectrometry (IRMS) has been established in doping control analysis to identify the endogenous or exogenous origin of a variety of steroidal analytes including the 19-norsteroid metabolite norandrosterone (NorA). NorA can be found naturally in human urine in trace amounts due to endogenous demethylation or in situ microbial degradation. The administration of nortestosterone (nandrolone) or different prohormones results in the excretion of urinary NorA. Usually, this can be detected by IRMS due to differing δ13 C values of synthetic 19-norsteroids compared to endogenous reference compounds. The consumption of uncastrated pig edible parts like offal or even meat may also lead to a urinary excretion of NorA. In order to determine the δ13 C values of such a scenario, urine samples collected after consumption of a wild-boar-testicle meal were analyzed. IRMS revealed highly enriched δ13 C values for urinary NorA, which could be related to the completely corn-based nutrition of the animal. Isotopic analysis of the boar's bristles demonstrated a dietary change from C3 -based forage, probably in winter and spring, to a C4 -based diet in the last weeks to months prior to death. These results supported the interpretation of an atypical test result of a Central European athlete's doping control sample with δ13 C values for NorA of -18 ‰, most probably caused by the consumption of a wild boar ragout. As stated before, athletes should be fully aware of the risk that consumption of wild boar may result in atypical or even adverse analytical findings in sports drug testing.