Analytical chemistry
Analytical toxicology
Drug testing
Mass spectrometry/Chromatography
24
Scopus Publications
Scopus Publications
Contamination of a drug consumption room with drugs and potential risks for social health care workers Flore Cuffaro, Georges Dahm, Claude Marson, Patrick Berlemont, Michel Yegles, et al. Harm Reduction Journal, 2024 Background Studies have shown that contamination of surfaces by illicit drugs frequently occurs in forensic laboratories when manipulating seized samples as well as in pharmacies and hospitals when preparing medicinal drugs. In this project, we extended these studies to a Drug Consumption Room to investigate drug levels and possible exposure of the staff members. Methods We investigated pre and post cleaning contamination by heroin and cocaine and their degradation products 6-monoacetylmorphine and benzoylecgonine on different surfaces (tables, counters, computers and door handles) and in the ambient air. We also collected urine and hair samples from staff members to check for potential short and long term contaminations. Results Medium to heavy contamination has been detected on most surfaces and door handles; as expected, air contamination was particularly high in the smoking room. Drug levels were < LOD to very low in the urine and the hair samples of staff members tested. Conclusion The cleaning efficiency of the surfaces, carried out by staff and drug users after drug consumption, was often not satisfactory. The very low drug levels in hair indicate that acute health risks for staff members are low.
Consumer expectations, drug effects, price and purity of heroin and cocaine purchased at drug consumption rooms Georges Dahm, Karin Roschel, Claude Marson, Adèle Bourmaud, Jennifer Macedo, et al. Harm Reduction Journal, 2023 Background Drug consumption rooms offer heroin and cocaine consumers a secure and hygienic environment including medical and social guidance. Despite the support and mentoring, only sparse information is available about how drug quality, drug prices and user expectations match at these locations. The present study reports analysis of these three parameters in two drug consumption rooms in Luxembourg. Methods Drug users were invited to participate in the project by handing in a few milligrams of the product they planned to consume for chemical analysis and filling out a short questionnaire about the price and their expectations. After consumption, they were asked to report the experienced effects. Drug quality was accessed using LC-Q-ToF and HPLC–UV, and a statistical analysis was carried out of the questionnaires that were correctly filled out. Results A total of 513 drug samples have been analyzed. Most consumers were looking for the relaxing/calming effects of heroin and the stimulating effects of cocaine, but they generally overestimated heroin potency and underestimated cocaine potency. No strong correlation based on Spearman’s ρ between drug user estimations, drug prices and drug quality was found. Conclusion To the best of our knowledge, this study is the first to combine drug analysis with heroin and cocaine user feedback about expectation, drug prices and drug effects. The analytical results were of great interest for users and the staff working at the drug consumption rooms. They may be a strong supplementary communication tool for health care workers when discussing effects and risks of highly toxic substance consumption.
Nickel in foodstuffs available on the Luxembourgish market and dietary intake Luc Schuler, Danny Zust, Georges Dahm, Fabienne Clabots Food Additives and Contaminants Part B Surveillance, 2023 Nickel is a food contaminant of natural or anthropogenic origin. Monitoring of contaminants in food in general allows obtaining an overview on the presence of substances that are undesirable to health. The aim of this study was to analyse nickel content in food of non-animal origin and beverages sold in Luxembourg to determine the exposure of the population to this contaminant. In total, 660 samples were analysed in the timeframe from 2017 to 2021. The results demonstrate high concentrations of nickel in cashew nuts, walnuts, hemp and sunflower seeds, dried peas, oregano, and cocoa powder. Surveillance of contaminants in food allows identifying contributors to the chronic and acute exposure of nickel in order to potentially set official maximum levels in European legislation in the future, allowing for better enforcement actions in case of contaminated products and increasing consumer protection.
Comprehensive Assessment of Local Population Chemical Exposome by Combination of Organic Pollutant- and Metal-Multi-Residue Analysis in Hair Alba Iglesias-González, Charline Schaeffer, Georges Dahm, Emilie M. Hardy, Achilleas Pexaras, et al. Exposure and Health, 2022 Awareness of the adverse effects of exposure to pollutant mixtures, possibly much more severe than individual chemicals, has drawn attention towards the necessity of using multi-residue methods to obtain the most possible comprehensive information on exposome. Among the different biological matrices used for exposure assessment, hair enables to detect the largest number of chemicals, including many classes such as persistent pollutants, hydrophilic metabolites and metals. Most biomonitoring studies are however focused on a limited number of pollutants and only give a partial information on exposure. Combining several multi-residue methods, the present study aimed at assessing the exposure of a population to an extensive variety of chemicals by hair analysis. One hair sample was collected from each participant (55 children and 134 adults). Samples were analysed with three different multi-residue methods, targeting, respectively, 152 organic pollutants (pesticides, PCBs, bisphenols, PBDEs), 62 polycyclic aromatic hydrocarbons (PAHs) and metabolites, nicotine and cotinine and 36 metals. From 33 to 70 organic chemicals were detected in each child’s hair sample, and from 34 up to 74 in adults. From 7 to 26 PAH were detected per child, and 7 to 21 in adults. Twenty-three to 27 metals were detected per child and 21 to 28 per adult. The highest median concentration were observed for zinc (143 μg /mg in children; 164 μg /mg in adults), bisphenol A (95.9 pg/mg in children; 64.7 pg/mg in adults) and nicotine (66.4 pg/mg in children; 51.9 pg/mg in adults). The present study provides the most comprehensive exposure assessment ever and highlights the simultaneous exposure to multiple classes of pollutants in the general population. The results support the use of multi-residue methods for future studies on exposure-associated effects, to document exposome and better consider the effect of chemical mixtures.
Cooking heroin the Turkish way: chemical investigation on an unusual heroin preparation method Georges Dahm, Claudia Allar, Raoul Schaaf, Adèle Bourmaud, Serge Schneider Harm Reduction Journal, 2021 Background Reports from experienced heroin users about an alternative and appreciated but harmful so-called “Turkish” heroin preparation technic led to the chemical investigation of the compounds produced during this process and investigation of the presence of other psychoactive contaminants. Methods Comparison of diacetylmorphine, 6-monoacetylmorphine, morphine, paracetamol and caffeine concentrations were performed in the non-processed material, after processing according to the standard and to the alternative preparation methods using liquid chromatography coupled to quadrupole time of flight mass spectrometry followed by statistical evaluation of the results. Results The two preparation methods had in common a diminution of diacetylmorphine as compared to the starting material but significantly more 6-monoacetylmorphine was produced using the “Turkish” preparation method as compared to the standard method. Conclusion The high amount of psychoactive 6-monoacetylmorphine may have an impact on the reported effects of heroin using the “Turkish” preparation procedure.
Investigation on heroin and cocaine quality in Luxembourg Adèle Bourmaud, Georges Dahm, François Meys, Nicolas Gengler, Alain Origer, et al. Harm Reduction Journal, 2021 Background Heroin and cocaine are among the most dangerous illicit drugs available and their presence on the market is increasing. These facts have led to the investigation of the quality of heroin and cocaine samples seized in Luxembourg by police and customs but also collected at the national supervised drug consumption facilities. Methods Samples obtained from 2019 to 2020 were analyzed to determine their composition and content using GC–MS, HPLC-UV and LC-Q-ToF. The statistical evaluation of concentration changes depending on the source of collection is based on an ANOVA single factor test and a two-tailed t test. Results Results showed important differences between seizure and collection sources. For both drugs, customs samples had significantly higher concentrations than police samples and the latter had significantly higher concentrations than samples from drug consumption facilities, whereas for heroin two cutting steps were identified, for cocaine samples only one appears to occur on the local market. Indeed, cocaine samples seized by police consisted of a mixture of low and high concentration samples. Conclusion The results show that extensive adulteration with pharmacological active and inactive compounds takes place at local levels, which, however, are different for heroin and cocaine. This knowledge on variability of quality of drugs should be considered in the elaboration of drug and harm prevention strategies.
In cellulo evaluation of the therapeutic potential of nhc platinum compounds in metastatic cutaneous melanoma Elsa Charignon, Mathilde Bouché, Caroline Clave-Darcissac, Georges Dahm, Gabriel Ichim, et al. International Journal of Molecular Sciences, 2020 We describe here the evaluation of the cytotoxic efficacy of two platinum (II) complexes bearing an N-heterocyclic carbene (NHC) ligand, a pyridine ligand and bromide or iodide ligands on a panel of human metastatic cutaneous melanoma cell lines representing different genetic subsets including BRAF-inhibitor-resistant cell lines, namely A375, SK-MEL-28, MeWo, HMCB, A375-R, SK-MEL-5-R and 501MEL-R. Cisplatin and dacarbazine were also studied for comparison purposes. Remarkably, the iodine-labelled Pt-NHC complex strongly inhibited proliferation of all tested melanoma cells after 1-h exposure, likely due to its rapid uptake by melanoma cells. The mechanism of this inhibitory activity involves the formation of DNA double-strand breaks and apoptosis. Considering the intrinsic chemoresistance of metastatic melanoma cells of current systemic treatments, these findings are promising and could give research opportunities in the future to improve the prognosis of patients suffering from unresectable metastatic melanoma that are not eligible or that do not respond to the most effective drugs available to date, namely BRAF inhibitors and the anti-PD-1 monoclonal antibody (mAb).
Synthesis and structural characterization of benzyl-functionalized N-heterocyclic carbene platinum complexes: Dramatic substituent effect on anti-cancer activity Georges Dahm, Mathilde Bouché, Corinne Bailly, Lydia Karmazin, Stéphane Bellemin-Laponnaz Journal of Organometallic Chemistry, 2019 A series of platinum (II) complexes bearing N-heterocyclic carbene NHC ligands functionalized by various benzyl moieties were synthesized and characterized. The molecular structure of two complexes has been confirmed by X-ray diffraction studies on single crystals. Investigation of in vitro cytotoxic activities against various cancer cell lines revealed a strong substituent effect: IC50 as low as 0.005 μM were obtained depending on the substituent on the benzyl moiety.
N-heterocyclic carbene-platinum complexes featuring an anthracenyl moiety: Anti-cancer activity and dna interaction Sébastien Harlepp, Edith Chardon, Mathilde Bouché, Georges Dahm, Mounir Maaloum, et al. International Journal of Molecular Sciences, 2019 A platinum (II) complex stabilized by a pyridine and an N-heterocyclic carbene ligand featuring an anthracenyl moiety was prepared. The compound was fully characterized and its molecular structure was determined by single-crystal X-ray diffraction. The compound demonstrated high in vitro antiproliferative activities against cancer cell lines with IC50 ranging from 10 to 80 nM. The presence of the anthracenyl moiety on the N-heterocyclic carbene (NHC) Pt complex was used as a luminescent tag to probe the metal interaction with the nucleobases of the DNA through a pyridine-nucleobase ligand exchange. Such interaction of the platinum complex with DNA was corroborated by optical tweezers techniques and liquid phase atomic force microscopy (AFM). The results revealed a two-state interaction between the platinum complex and the DNA strands. This two-state behavior was quantified from the different experiments due to contour length variations. At 24 h incubation, the stretching curves revealed multiple structural breakages, and AFM imaging revealed a highly compact and dense structure of platinum complexes bridging the DNA strands.
N-Heterocyclic carbene-polyethyleneimine (PEI) platinum complexes inducing human cancer cell death: Polymer carrier impact May Wantz, Mathilde Bouché, Georges Dahm, Neïla Chekkat, Sylvie Fournel, et al. International Journal of Molecular Sciences, 2018 The high interest in N-Heterocyclic platinum carbene complexes in cancer research stems from their high cytotoxicity to human cancer cells, their stability, as well as their ease of functionalization. However, the development of these new molecules as anticancer agents still faces multiple challenges, in particular solubility in aqueous media. Here, we synthesized platinum-NHC bioconjugates that combine water-solubility and cytotoxicity by using polyethyleneimine as polymer carrier. We showed on 8 different types of cells that the activity of these conjugates is modulated by the size of the polymer and the overall density of metal ions onto polymer chains. Using HCT116 cells, the conjugates displayed an effective activity after only 45 min of exposure in vitro correlated with a quick uptake by the cells as shown by the use of various fluorescent-tagged derivatives.
