The knowledge of the biotransformation of compounds prohibited by the World Anti Doping Agency is of high concern as doping analyses are mostly based on the detection of metabolites instead of the parent compounds abused by athletes. While the self-administration of doping-relevant compounds is from an ethical point of view a rather problematic method to investigate metabolism, the usage of cell culture systems allows for studies on biotransformation in vitro. Five cell culture models with different tissue origin (liver, ovary, skin, kidney, and testis) were comparatively incubated with testosterone and epitestosterone as well as with the synthetic testosterone derivatives 17α-methyltestosterone and 4-chlorotestosterone to investigate the impact of synthetic modifications on phase I metabolic pathways. Cell culture supernatants were analyzed by high-performance liquid chromatography-tandem mass spectrometry. All cell lines possessed the default steroid phase I biotransformation reactions. The highest conversion rate was observed in ovarian (BG-1) and liver cells (HepG2). For BG-1 and skin cells (HaCaT), the 5α-reductase products 5αdihydrotestosterone (for both) and 5α-androstane-3α/β,17β-diol (for BG-1 solely) were found to be prevailing after testosterone incubation. In kidney (COS-1) and HepG2 cells, the 17β-hydroxysteroid dehydrogenase activity was predominant as supported by the observation that the 17α-OH (epitestosterone) and the methyl group (17α-methyltestosterone) impeded the conversion rate in these cell lines. In conclusion, future work should extend the characterization of the BG-1 and HepG2 cells on phase II metabolic pathways to examine whether they are suitable models for the generation of metabolite reference collections comparable to those obtained by human excretion studies.

The parameters which influence the determination of the major glycosylated haemoglobin fraction (HbA1c) with the thiobarbituric acid (TBA) method are described. Conditions for an optimal determination method are given. The correlation with the fast haemoglobin determination by column chromatography is greater than 0.9. The influence of storage on blood, washed erythrocytes and haemolysate in respect to HbA1c values obtained with the method described, was also investigated. Normal and pathological values from 78 patients correlate well with the fasting blood sugar levels (r greater than 0.9).

Animals vary genetically in responses to dietary change. Both mitochondrial and nuclear genomes contribute to this variation, but the role of combinatorial "mito-nuclear" genetic variation is understudied. We do not know whether specific nutrients modify patterns of mito-nuclear variation, nor whether putative epigenetic mechanisms play a role. Here, we show that enriching dietary essential amino acids or lipids modifies patterns of mito-nuclear variation in Drosophila life-history, including transgenerational effects of lipids. Systematically evaluating alternative statistical models revealed that diet-mito-nuclear interactions were a leading driver of phenotypic variation. Mito-nuclear genotype repeatably predicted phenotypic impacts of nutritional changes, but genotypes bearing naturally co-occurring pairs of mitochondria and nuclei did not necessarily outperform novel pairings, suggesting that nutrition-dependent phenotypes cannot easily be optimised by matching mitochondria to coincident nuclear genotypes. These results enhance understanding of how nutrition and genetics sculpt phenotype, with potential implications for human mitochondrial transfer therapies.

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