71 research outputs found
Off-target activity of NBOMes and NBOMe analogs at the mu opioid receptor
No full textNew psychoactive substances (NPS) are introduced on the illicit drug market at a rapid pace. Their molecular targets are often inadequately elucidated, which contributes to the delayed characterization of their pharmacological effects. Inspired by earlier findings, this study set out to investigate the mu opioid receptor (MOR) activation potential of a large set of psychedelics, substances which typically activate the serotonin (5-HT2A) receptor as their target receptor. We observed that some substances carrying the N-benzyl phenethylamine (NBOMe) structure activated MOR, as confirmed by both the NanoBiT (R) beta arr2 recruitment assay and the G protein-based AequoScreen (R) Ca2+ release assay. The use of two orthogonal systems proved beneficial as some aspecific, receptor independent effects were found for various analogs when using the Ca2+ release assay. The specific 'off-target' effects at MOR could be blocked by the opioid antagonist naloxone, suggesting that these NBOMes occupy the same common opioid binding pocket as conventional opioids. This was corroborated by molecular docking, which revealed the plausibility of multiple interactions of 25I-NBOMe with MOR, similar to those observed for opioids. Additionally, structure-activity relationship findings seen in vitro were rationalized in silico for two 25I-NBOMe isomers. Overall, as MOR activity of these psychedelics was only noticed at high concentrations, we consider it unlikely that for the tested compounds there will be a relevant opioid toxicity in vivo at physiologically relevant concentrations. However, small modifications to the original NBOMe structure may result in a panel of more efficacious and potent MOR agonists, potentially exhibiting a dual MOR/5-HT2A activation potential
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A Search for Ultra-heavy Resonances Decaying to Vector-like Quark Pairs in All Hadronic Final States at the CMS Experiment
No full textThis dissertation presents the foundation of an analysis that searches for a scalar diquark, , decaying to pairs of vector-like quarks, , in the fully hadronic final state. In total, 137~{fb} of CMS proton-proton collision luminosity at = 13~{\TeV} is analyzed, which corresponds to the full integrated luminosity of the Large Hadron Collider's Run 2. This search considers masses between 4-8~{\TeV} and masses between 1-3~{\TeV} where appropriate. Consequently, a wide variety of final-state kinematics are encompassed. A new technique is employed that uses a series of Lorentz boosts on an arbitrary number of selected large-cone lab-frame jets to reach the approximate rest frame where jets are geometrically assigned to daughter particles. The resulting jet groupings, called ``superjets'', can then be tagged as signal by placing cuts on various substructure variables. The signal region is defined as having two such tagged superjets. A simultaneous fit is performed over the signal region and a signal-poor region using the Higgs Combine tool for combined Run 2 Asimov data, and the resulting expected limits show model sensitivity up to = 8~{\TeV} for model parameters = = 1. A number of statistical tests are also generated following fits to ``antitag'' control regions and show reasonable agreement between observed data and simulations
A Search for Ultra-heavy Resonances Decaying to Vector-like Quark Pairs in All Hadronic Final States at the CMS Experiment
No full textFactors influencing the guidance of shared parenthood over time : perspectives of foster care workers
No full textThis study explores the factors shaping foster care workers' (FCWs) guidance on shared parenthood between biological parents and foster carers in long-term placements. Using a qualitative longitudinal analysis of interviews with nine FCWs over 6-10 months, four influencing factors were identified: organizational, professional, case-specific, and interpersonal. Organizational factors proved most decisive, leading FCWs to adopt a cautious, incremental approach, while individual assumptions about power, trust, and truth shaped other factors. Policy should consider the balance between stability and shared parenthood. FCWs are encouraged to deepen their understanding of these dynamics to leverage opportunities and mitigate blind spots. Further research is recommended
The meaning of shared parenthood in long‐term foster care : the perspectives of parents and foster carers
No full textShared parenthood is increasingly emphasized in long-term foster care placements across European countries, including Flanders, where our study was conducted. However, despite its growing importance, there is a lack of comprehensive understanding regarding the dynamics and pedagogical conceptualization of shared parenthood. This research seeks to bridge the gap by investigating how parents and foster carers perceive and navigate parenting roles. Through in-depth interviews with 12 parents and 12 foster carers from 10 long-term foster care cases, thematic and narrative analyses were employed to explore shared parenting dynamics. The findings underscore the significant impact of power dynamics on the relationship, often resulting in prolonged silences and reluctance to address issues openly. By elucidating both the promoting and impeding factors, this study sheds light on the complexities of shared parenting within long-term foster care arrangements. In conclusion, the study emphasizes the importance of recognizing and discussing the normative notion of shared parenting to facilitate its successful implementation in long-term foster care placements
In vitro functional characterization of a panel of non-fentanyl opioid new psychoactive substances
No full textThe landscape of new psychoactive substances (NPS) is constantly evolving, with new compounds entering the illicit drug market at a continuous pace. Of these, opioid NPS form a threat given their high potency and prevalence. Whereas previously, the use of fentanyl and fentanyl derivatives was the main point of attention, legislations have reacted accordingly, whichmay have been a driving force towards the (ab)use of alternative µ-opioid receptor (MOR) agonists. In contrast to fentanyl (analogues), details on these novel non-fentanyl opioid NPS are scarce. We investigated the biological activity of a panel of 11 ‘alternative’, newly emerging MOR agonists (2-methyl-AP-237, AP-237, bromadol, brorphine, butorphanol, isotonitazene, mitragynine, 7-OH-mitragynine, MT-45, piperidylthiambutene, and tianeptine) using two closely related in vitro MOR activation bio-assays, monitoring either G protein (mini-Gi), or β-arrestin2 (βarr2) recruitment. Activity profles were obtained for all tested compounds, with values for potency (EC50) ranging from 1.89 nM (bromadol) to>3 µM (AP-237 and tianeptine).
Bromadol, brorphine, isotonitazene, piperidylthiambutene, and tianeptine had the highest efcacy (Emax) values, exceeding that of the reference compound hydromorphone≥1.3-fold (βarr2 assay) and>2.6-fold (mini-Gi assay). Information on the recruitment of two distinct signaling molecules additionally enabled evaluation of biased agonism; none of the evaluated opioids being signifcantly biased. Taken together, this study is the frst to systematically investigate the in vitro biological activity of a diverse panel of emerging non-fentanyl opioid NPS at MOR. Given the known danger of (fatal) intoxications with many opioid NPS, it is important to continuously monitor and characterize newly emerging compounds
Activity-Based Detection and Bioanalytical Confirmation of a Fatal Carfentanil Intoxication
No full textCarfentanil, one of the most potent opioids known, has recently been reported as a contaminant in street heroin in the United States and Europe, and is associated with an increased number of life-threatening emergency department admissions and deaths. Here, we report on the application of a novel in vitro opioid activity reporter assay and a sensitive bioanalytical assay in the context of a fatal carfentanil intoxication, revealing the highest carfentanil concentrations reported until now. A 21-year-old male was found dead at home with a note stating that he had taken carfentanil with suicidal intentions. A foil bag and plastic bag labeled “C.50” were found at the scene. These bags were similar to a sample obtained by the Belgian Early Warning System on Drugs from a German darknet shop and to those found in the context of a fatality in Norway. Blood, urine and vitreous, obtained during autopsy, were screened with a newly developed in vitro opioid activity reporter assay able to detect compounds based on their μ-opioid receptor activity rather than their chemical structure. All extracts showed strong opioid activity. Results were confirmed by a bioanalytical assay, which revealed extremely high concentrations for carfentanil and norcarfentanil. It should be noted that carfentanil concentrations are typically in pg/mL, but here they were 92 ng/mL in blood, 2.8 ng/mL in urine, and 23 ng/mL in vitreous. The blood and vitreous contained 0.532 and 0.300 ng/mL norcarfentanil, respectively. No norcarfentanil was detected in urine. This is the first report where a novel activity-based opioid screening assay was successfully deployed in a forensic case. Confirmation and quantification using a validated bioanalytical procedure revealed the, to our knowledge, highest carfentanil concentrations reported in humans so far
In vitro structure-activity relationship determination of 30 psychedelic new psychoactive substances by means of beta-arrestin 2 recruitment to the serotonin 2A receptor
No full textSerotonergic psychedelics, substances exerting their efects primarily through the serotonin 2A receptor (5-HT2AR), continue to comprise a substantial portion of reported new psychoactive substances (NPS). The exact mechanisms of action of psychedelics still remain to be elucidated further, and certain pathways remain largely unexplored on a molecular level for this group of compounds. A systematic comparison of substances belonging to diferent subclasses, monitoring the receptor-proximal β-arrestin 2 recruitment, is lacking. Based on a previously reported in vitro bioassay employing functional complementation of a split nanoluciferase to monitor β-arrestin 2 recruitment to the 5-HT2AR, we here report on the setup of a stable HEK 293 T cell-based bioassay. Following verifcation of the performance of this new stable cell system as compared to a system based on transient transfection, the stable expression system was deemed suitable for the pharmacological characterization of psychedelic NPS. Subsequently, it was applied for the in vitro assessment of the structure–activity relationship of a set of 30 substances, representing diferent subclasses of phenylalkylamine psychedelics, among which 12 phenethylamine derivatives (2C-X), 7 phenylisopropylamines (DOx) and 11 N-benzylderivatives (25X-NB). The resulting potency and efcacy values provide insights into the structure–activity relationship of the tested compounds, overall confrm fndings observed with other reported in vitro assays, and even show a signifcant correlation with estimated common doses. This approach, in which a large series of psychedelic NPS belonging to diferent subclasses is comparatively tested, using a same assay setup, monitoring a receptor-proximal event, not only gives pharmacological insights, but may also allow prioritization of legal
actions related to the most potent -and potentially dangerous- compounds
Activity-based detection of consumption of synthetic cannabinoids in authentic urine samples using a stable cannabinoid reporter system
No full textSynthetic cannabinoids (SCs) continue to be the largest group of new psychoactive substances (NPS) monitored by the European Monitoring Center of Drugs and Drugs of Abuse (EMCDDA). The identification and subsequent prohibition of single SCs has driven clandestine chemists to produce analogues of increasing structural diversity, intended to evade legislation. That structural diversity, combined with the mostly unknown metabolic profiles of these new SCs, poses a big challenge for the conventional targeted analytical assays, as it is difficult to screen for "unknown" compounds. Therefore, an alternative screening method, not directly based on the structure but on the activity of the SC, may offer a solution for this problem. We generated stable CB1 and CB2 receptor activation assays based on functional complementation of a split NanoLuc luciferase and used these to test an expanded set of recent SCs (UR-144, XLR-11, and their thermal degradation products; AB-CHMINACA and ADB-CHMINACA) and their major phase I metabolites. By doing so, we demonstrate that several major metabolites of these SCs retain their activity at the cannabinoid receptors. These active metabolites may prolong the parent compound's psychotropic and physiological effects and may contribute to the toxicity profile. Utility of the generated stable cell systems as a first -line screening tool for SCs in urine was also demonstrated using a relatively large set of authentic urine samples. Our data indicate that the stable CB reporter assays detect CB receptor, activation by extracts of urine in which SCs (or their metabolites) are present at low- or subnanomolar (ng/mL) level. Hence, the developed assays do not only allow activity profiling of SCs and their metabolites, it may also serve as a screening tool, complementing targeted and untargeted analytical assays and preceding analytical (mass spectrometry based) confirmation
Setup of a serotonin 2A receptor (5-HT2AR) bioassay : demonstration of its applicability to functionally characterize hallucinogenic new psychoactive substances and an explanation why 5-HT2AR bioassays are not suited for universal activity-based screening of biofluids for new psychoactive substances
No full textClassic or serotonergic hallucinogens comprise the third largest number of reported new psychoactive substances (NPS), according to the United Nations Office on Drugs and Crime. While being structurally very divergent, they share activation of the serotonin 2A receptor (S-HT2AR), a G protein-coupled receptor, as their main pharmacological mechanism. Here, we report on the development of a 5-HT2AR bioassay, which monitors beta-arrestin2 recruitment to the receptor via a split-luciferase system, as a measure of receptor activation. Possible applications of the bioassay would lie in the characterization of serotonergic hallucinogens and the screening of these compounds in biofluids based on their serotonergic activity, rather than on their specific structures. The developed bioassay allowed the determination of the potency and efficacy of representatives of different classes of hallucinogens (LSD, 5-MeO-DALT, mescaline) and of a selected group 2C hallucinogens and their corresponding NBOMes, with EC50 values from the subnanomolar (NBOMes) to micromolar (mescaline) range. When implementing the bioassay for the screening of plasma, a pronounced receptor activation was already observed in blank samples, which could be ascribed to endogenous serotonin, as suggested by annihilation of this activity by a 5-HT2AR antagonist or after incubation with MAO-A (monoamine oxidase-A). The presence and degradability by MAO-A of serotonin in plasma extracts were confirmed by LC-HRMS. Due to the possible metabolism of certain hallucinogens by MAO-A, which would cause a bias in the detectability of compounds in biofluids, the main application potential of this bioassay lies in the characterization of these scarcely characterized serotonergic hallucinogens
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