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ObjectiveInflammatory bowel disease (IBD) is a multifactorial condition driven by genetic and environmental risk factors. A genetic variation in the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene has been associated with autoimmune disorders while protecting from the IBD subtype Crohn’s disease. Mice expressing the murine orthologous PTPN22-R619W variant are protected from intestinal inflammation in the model of acute dextran sodium sulfate (DSS)-induced colitis. We previously identified food-grade titanium dioxide (TiO2, E171) as a neglected IBD risk factor. Here, we investigate the interplay of the PTPN22 variant and TiO2-mediated effects during IBD pathogenesis.DesignAcute DSS colitis was induced in wild-type and PTPN22 variant mice (PTPN22-R619W) and animals were treated with TiO2nanoparticles during colitis induction. Disease-triggering mechanisms were investigated using bulk and single-cell RNA sequencing.ResultsIn mice, administration of TiO2nanoparticles abrogated the protective effect of the variant, rendering PTPN22-R619W mice susceptible to DSS colitis. In early disease, cytotoxic CD8+T-cells were found to be reduced in the lamina propria of PTPN22-R619W mice, an effect reversed by TiO2administration. Normalisation of T-cell populations correlated with increasedIfngexpression and, at a later stage of disease, the promoted prevalence of proinflammatory macrophages that triggered severe intestinal inflammation.ConclusionOur findings indicate that the consumption of TiO2nanoparticles might have adverse effects on the gastrointestinal health of individuals carrying the PTPN22 variant. This demonstrates that environmental factors interact with genetic risk variants and can reverse a protective mechanism into a disease-promoting effect.

The interest in metabolomic studies has rapidly increased over the past few years. Changes of endogenous compounds are typically detected in plasma or urine. However, the use of hair allows for long-term monitoring of metabolomic changes and has recently started being applied to metabolomic studies. Within the proposed study, we aimed for a systematical investigation of different pre-analytical parameters on detected metabolites from different chemical classes in hair. For this purpose, three different parameters were varied: (1) multi-step decontamination (dichloromethane (DCM), acetone, H2O, acetone; H2O, acetone, DCM, acetone; and H2O, methanol/acetone), (2) homogenization (pulverization vs. cutting into snippets), and (3) extraction (acetonitrile (ACN)/buffer pH 4 vs. ACN/H2O vs. ACN/buffer pH 8.5). To include as many metabolites as possible, samples were analyzed by high-resolution time of flight mass spectrometry coupled to liquid chromatography (HPLC-HRMS) and additionally by gas chromatography high-resolution mass spectrometry (GC-HRMS) followed by untargeted-like data processing, respectively. The application of different decontamination procedures yielded similar results, although pointing to a trend towards increased washing-out effects if protic solvents were used as a first washing step. Pulverization of hair samples was favorable in terms of detected and tentatively identified metabolites. Evaluation of extraction solvents showed differences in extraction yield for the majority of investigated metabolites, yet, a prediction of metabolite extraction according to their pKa values was not possible. Overall, successive decontamination with DCM, acetone, H2O, and acetone; homogenization by pulverization; and extraction with ACN/H2O produced reliable results.

Inflammatory bowel disease (IBD) is a multifactorial condition driven by genetic and environmental risk factors. A genetic variation in the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene has been associated with autoimmune disorders while protecting from the IBD subtype Crohn's disease. Mice expressing the murine orthologous PTPN22-R619W variant are protected from intestinal inflammation in the model of acute dextran sodium sulfate (DSS)-induced colitis. We previously identified food-grade titanium dioxide (TiOAcute DSS colitis was induced in wild-type and PTPN22 variant mice (PTPN22-R619W) and animals were treated with TiOIn mice, administration of TiOOur findings indicate that the consumption of TiO

Untargeted metabolomic studies are used for large-scale analysis of endogenous compounds. Due to exceptional long detection windows of incorporated substances in hair, analysis of hair samples for retrospective monitoring of metabolome changes has recently been introduced. However, information on the general behavior of metabolites in hair samples is scarce, hampering correct data interpretation so far. The presented study aimed to investigate endogenous metabolites depending on hair color and along the hair strand and to propose recommendations for best practice in hair metabolomic studies. A metabolite selection was analyzed using untargeted data acquisition in genuine hair samples from different hair colors and after segmentation in 3 cm segments. Significant differences in metabolites among hair colors and segments were found. In conclusion, consideration of hair color and hair segments is necessary for hair metabolomic studies and, subsequently, recommendations for best practice in hair metabolomic studies were proposed.

Hair analysis has become an integral part in forensic toxicological laboratories for e.g. assessment of drug or alcohol abstinence. However, hair samples can be manipulated by cosmetic treatments, altering drug concentrations which eventually leads to false negative hair test results. In particular oxidative bleaching of hair samples under alkaline conditions significantly affects incorporated drug concentrations. To date, current techniques to detect cosmetic hair adulterations bear limitations such as the implementation of cut-off values or the requirement of specialized instrumentations. As a new approach, untargeted hair metabolomics analysis was applied to detect altered, endogenous biomolecules that could be used as biomarkers for oxidative cosmetic hair treatments. For this, genuine hair samples were treated in vitro with 9% hydrogen peroxide (H2O2) for 30 minutes. Untreated and treated hair samples were analyzed using liquid-chromatography high-resolution time-of-flight mass spectrometry. In total, 69 metabolites could be identified as significantly altered after hair bleaching. The majority of metabolites decreased after bleaching, yet totally degraded metabolites were most promising as suitable biomarkers. The formation of biomarker ratios of metabolites decreasing and increasing in concentrations improved the discrimination of untreated and treated hair samples. With the results of this study, the high variety of identified biomarkers now offers the possibility to include single biomarkers or biomarker selections into routine screening methods for improved data interpretation of hair test results.

Hair analysis has become a valuable tool in forensic toxicology to assess drug or alcohol abstinence. Yet, hair adulteration by cosmetic products presents a major challenge for forensic hair analysis. Oxidative treatments, e.g. bleaching, may lead to analyte loss and thereby to false negative results. Currently, the eumelanin degradation product 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA) serves as a marker for oxidative hair treatment, but requires the definition of cut-off values. To investigate further eumelanin degradation products as markers for oxidative hair treatment, hair samples with and without in vitro bleaching (hydrogen peroxide (H2 O2 ) concentrations 1.9% up to 12%; incubation times 15 min, 30 min, 60 min) were analyzed by liquid chromatography coupled to high-resolution time of flight mass spectrometry (HPLC-HRMS). The distribution of eumelanin degradation products along the hair shaft was investigated for routine applicability after segmentation of cosmetically untreated hair samples and authentically treated hair samples. The signals of the eumelanin degradation products PTCA, 1H-pyrrole-2,3,4-tricarboxylic acid (isoPTCA), and 1H-pyrrole-2,3,4,5-tetracarboxylic acid (PTeCA) were found to be significantly elevated after in vitro bleaching already with low H2 O2 concentrations and after short incubation times. In contrast to PTCA and isoPTCA, PTeCA was not detectable in cosmetically untreated segments up to 12 cm from hair root and was only formed through the oxidation process. The results of the study show that the detection of PTeCA within the proximal 3 to 6 cm segment can be applied to reliably detect hair adulteration attempts through hair bleaching.

Driving under the influence of alcohol and/or drugs (DUID) is a safety issue of increasing public concern. When a police officer has reasonable grounds to classify a driver as impaired, he may arrange for a blood sample to be taken. In many countries, alcohol analysis only is ordered if impairment is suspected to be exclusively due to alcohol while comprehensive toxicological screening will be performed if additional suspicion for other illegal drugs of abuse (DoA) or medicinal drugs is on hand. The aim of the present study was firstly to evaluate whether signs of impairment can be differentiated to be caused by alcohol alone or a combination of alcohol and other driving-impairing drugs and secondly to which extent additional drugs are missed in suspected alcohol-impaired drivers. A total of 293 DUID cases (negative n=41; alcohol positive only, n=131; alcohol+active drug positive, n=121) analyzed in 2015 in the Canton of Zurich were evaluated for their documented impairment symptoms by translating these into a severity score and comparing them applying principle component analysis (PCA). Additional 500 cases suspected for alcohol-impaired driving only were reanalyzed using comprehensive LC-MS/MS screening methods covering about 1500 compounds. Drugs detected were classified for severity of driving impairment using the classification system established in the DRUID study of the European Commission. As partly expected from the pharmacological and toxicological point of view, PCA analysis revealed no differences between signs of impairment caused by alcohol alone and those caused by alcohol plus at least one active drug. Breaking it down to different blood alcohol concentration ranges, only between 0.3 and 0.5g/kg trends could be observed in terms of more severe impairment for combined alcohol and drug intake. In the 500 blood samples retrospectively analyzed in this study, a total of 330 additional drugs could be detected; in some cases up to 9 co-ingested ones. In total, 37% of all cases were positive for additional drugs, thereby 15% of classic DoAs and further 9% of prescription drugs with a severe risk to cause driving impairment based on the DRUID classification system. A decision whether signs of impairment are related to alcohol alone or to the combination of alcohol and other drugs is impossible. Taking into consideration the high rate of missed drugs in DUI cases, police should think about increasing the number of DUID cases in countries were sanctioning differs between alcohol and alcohol plus drug impaired driving.

Objective Metabolomic studies have gained increasing interest over the past few years. Hair in particular represents an alternative to common matrices (e.g. blood, urine) for the detection of robust biomarkers: it provides a long-term monitoring of endogenous compounds as they are constantly incorporated during hair growth. For an initial biomarker search, usually a non-hypothesis driven approach (untargeted) is applied. Such an approach could be of great interest for example to identify endogenous markers to objectively differentiate cosmetically untreated from treated hair (e.g. bleaching). However, so far, little is known about the ‘hair metabolome’ and its analysis. Therefore, as a prerequisite, knowledge about presence of endogenous metabolites from different compound classes in hair and a suitable sample preparation for their reliable detection is mandatory. Methods Different decontamination protocols (dichloromethane (DCM)/acetone/H2O/acetone and H2O/acetone/DCM/acetone), homogenization procedures (pulverization/cutting) and extraction solvent mixtures [acetonitrile (ACN)/H2O, ACN/buffer pH 4 and ACN/buffer pH 8.5] were tested. Extracts and corresponding wash water solutions were analyzed by liquid chromatography high-resolution (HR) MS and MS/MS (Sciex 6600 TripleTOF) and GC-HRMS (Thermo Scientific Q Exactive), both with untargeted data acquisition. Cosmetically untreated hair samples of one individual were either left untreated or bleached in vitro for 30 min with a mixture of bleaching oxidase (containing 9% H2O2) and bleaching oxidation powder, n = 5 per group. Extracts were analyzed by LC-MS/MS. (Tentative) identification of metabolites was performed using Progenesis Qi and PeakView. Results and discussion The detection of different metabolite classes was possible (e.g. fatty acids, amino acids and derivatives, acylcarnitines) using untargeted hair metabolome analysis. Pulverization of hair samples showed higher homogeneity for most metabolites compared to snippets. Extraction with ACN/H2O led to a good coverage of metabolites. Comparing untreated and bleached hair samples, a targeted search for 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA) was conducted as it was recently described as a marker for cosmetic hair treatment [1] . PTCA could be detected and identified with a reference standard. A significant increase was observed after bleaching. Additionally, another metabolite formed during treatment could be found in bleached hair samples and was tentatively identified as 1H-pyrrole-2,3,4,5-tetracarboxylic acid (PTeCA). Conclusion Establishing a suitable sample preparation for hair metabolomic analyses is a challenging task. However, our study showed reliable metabolite detection from different chemical classes. The identification of PTCA in combination with the identification of an additional metabolite formed through bleaching served as a proof of concept for the developed untargeted workflow. Future studies should focus on the confirmation of these findings with a larger number of hair samples.

Lysergic acid diethylamide (LSD) is a semi-synthetic hallucinogen that has gained popularity as a recreational drug and has been investigated as an adjunct to psychotherapy. Analysis of LSD represents a major challenge in forensic toxicology due to its instability, low drug concentrations, and short detection windows in biological samples. A new, fast, and sensitive microflow liquid chromatography (MFLC) tandem mass spectrometry method for the validated quantification of LSD, iso-LSD, 2-oxo 3-hydroxy-LSD (oxo-HO-LSD), and N-desmethyl-LSD (nor-LSD) was developed in plasma and applied to a controlled pharmacokinetic (PK) study in humans to test whether LSD metabolites would offer for longer detection windows. Five hundred microlitres of plasma were extracted by solid phase extraction. Analysis was performed on a Sciex Eksigent MFLC system coupled to a Sciex 5500 QTrap. The method was validated according to (inter)-national guidelines. MFLC allowed for separation of the mentioned analytes within 3 minutes and limits of quantification of 0.01 ng/mL. Validation criteria were fulfilled for all analytes. PK data could be calculated for LSD, iso-LSD, and oxo-HO-LSD in all participants. Additionally, hydroxy-LSD (HO-LSD) and HO-LSD glucuronide could be qualitatively detected and PK determined in 11 and 8 subjects, respectively. Nor-LSD was only sporadically detected. Elimination half-lives of iso-LSD (median 12 h) and LSD metabolites (median 9, 7.4, 12, and 11 h for oxo-HO-LSD, HO-LSD, HO-LSD-gluc, and nor-LSD, respectively) exceeded those of LSD (median 4.2 h). However, screening for metabolites to increase detection windows in plasma seems not to be constructive due to their very low concentrations. Copyright © 2016 John Wiley & Sons, Ltd.