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Featured researches published by Stefan Kneisel.


Addiction | 2013

Acute toxicity due to the confirmed consumption of synthetic cannabinoids: clinical and laboratory findings.

Maren Hermanns-Clausen; Stefan Kneisel; Bela Szabo; Volker Auwärter

AIMS Recently, several synthetic cannabinoids were identified in herbal mixtures consumed as recreational drugs alternative to cannabis products. The aim was to characterize the acute toxicity of synthetic cannabinoids as experienced by emergency patients. DESIGN This was a retrospective study targeting patients seeking emergency treatment after recreational use of synthetic cannabinoids. SETTING AND PARTICIPANTS Patients were selected from the database of the Poisons Information Center Freiburg between September 2008 and February 2011. The inclusion criteria were: hospitalization, available clinical reports and analytical verification of synthetic cannabinoid uptake. In total, 29 patients were included (age 14-30 years, median 19; 25 males, four females). MEASUREMENTS Clinical reports were evaluated and synthetic cannabinoids and other drugs were determined analytically. FINDINGS CP-47,497-C8 (one), JWH-015 (one), JWH-018 (eight), JWH-073 (one), JWH-081 (seven), JWH-122 (11), JWH-210 (11), JWH-250 (four) and AM 694 (one) were quantified in blood samples. JWH-018 was most common in 2008-9, JWH-122 in 2010, and JWH-210 in 2011. Tachycardia, agitation, hallucination, hypertension, minor elevation of blood glucose, hypokalaemia and vomiting were reported most frequently. Chest pain, seizures, myoclonia and acute psychosis were also noted. CONCLUSIONS There appears to have been an increase in use of the extremely potent synthetic cannabinoids JWH-122 and JWH-210. Acute toxic symptoms associated with their use are also reported after intake of high doses of cannabis, but agitation, seizures, hypertension, emesis and hypokalaemia seem to be characteristic to the synthetic cannabinoids, which are high-affinity and high-efficacy agonists of the CB(1) receptor. Thus, these effects are due probably to a strong CB(1) receptor stimulation.


International Journal of Legal Medicine | 2014

Driving under the influence of synthetic cannabinoids (“Spice”): a case series

Frank Musshoff; Burkhard Madea; Gerhard Kernbach-Wighton; Wolfgang Bicker; Stefan Kneisel; Melanie Hutter; Volker Auwärter

Recreational use of synthetic cannabinoid receptor agonists—so-called “Spice” products—became very popular during the last few years. Several reports on clinical symptoms and poisonings were published. Unfortunately, most of these reports do not contain any analytical data on synthetic cannabinoids in body fluids, and no or only a limited number of cases were reported concerning driving under the influence (DUI) of this kind of drugs. In this article, several cases of DUI of synthetic cannabinoids (AM-2201, JWH-018, JWH-019, JWH-122, JWH-210, JWH-307, MAM-2201 (JWH-122 5-fluoropentyl derivative), and UR-144) are presented, focusing on analytical results and signs of impairment documented by the police or the physicians who had taken the blood sample from the suspects. Consumption of synthetic cannabinoids can lead to impairment similar to typical performance deficits caused by cannabis use which are not compatible with safe driving. These deficits include centrally sedating effects and impairment of fine motor skills necessary for keeping the vehicle on track. Police as well as forensic toxicologists and other groups should become familiar with the effects of synthetic cannabinoid use, and be aware of the fact that drug users may shift to these “legal” alternatives due to their nondetectability by commonly used drug screening tests based on antibodies. Sophisticated screening procedures covering the complete range of available compounds or their metabolites have to be developed for both blood/serum and urine testing.


Journal of Mass Spectrometry | 2013

Characteristics of the designer drug and synthetic cannabinoid receptor agonist AM-2201 regarding its chemistry and metabolism.

Melanie Hutter; Bjoern Moosmann; Stefan Kneisel; Volker Auwärter

Aminoalkylindoles, a subclass of synthetic cannabinoid receptor agonists, show an extensive and complex metabolism in vivo, and due to their structural similarity, they can be challenging in terms of unambiguous assignment of metabolic patterns in urine samples to consumed substances. The situation may even be more complicated as these drugs are usually smoked, and the high temperature exposure may lead to formation of artifacts. Typical metabolites of JWH-018 (Naphthalen-1-yl(1-pentyl-1H-indol-3-yl)methanone) were reportedly detected not only in urine samples collected after consumption of JWH-018 but also after AM-2201 (1-(5-fluoropentyl-1H-indol-3-yl)-(naphthalene-1-yl)methanone) use. The aim of the presented study was to evaluate if typical JWH-018 metabolites can be formed metabolically in humans and if JWH-018 may be formed artifactually during smoking of AM-2201. Therefore, one of the authors ingested 5 mg of pure AM-2201, and serum as well as urine samples were analyzed subsequently. Additionally, the smoke condensate from a cigarette laced with pure AM-2201 was investigated. In addition, urine samples of patients after known consumption of AM-2201 or JWH-018 were evaluated. The results of the study prove that typical metabolites of JWH-018 and JWH-073 are built in humans after ingestion of AM-2201. However, the N-(4-hydroxypentyl) metabolite of JWH-018, which is the major metabolite after JWH-018 use, was not detected after the self-experiment. In the smoke condensate, small amounts of JWH-018 and JWH-022 (Naphthalen-1-yl[1-(pent-4-en-1-yl)-1H-indol-3-yl]methanone) were detected. Nevertheless, the results of our study suggest that the amounts absorbed by smoking do not significantly influence the metabolic pattern in urine samples. Therefore, the N-(4-hydroxypentyl) metabolite of JWH-018 can serve as a valuable marker to distinguish consume of products containing AM-2201 from JWH-018 use.


Drug Testing and Analysis | 2013

Acute intoxication by synthetic cannabinoids – Four case reports

Maren Hermanns-Clausen; Stefan Kneisel; Melanie Hutter; Bela Szabo; Volker Auwärter

receptor-mediated effectsare changes in mood, pain perception, state of arousal, bodytemperature, cardiovascular regulation, and food intake.Recently, synthetic cannabinoids appeared on the drugmarket, mostly as undeclared additives in ‘herbal mixtures’ namedfor example ‘Spice’, ‘Lava Red’ or ‘Jamaican Gold’. The use ofsynthetic cannabinoids is driven by several factors. After the intro-duction of new compounds, their use is initially not restricted byprohibition. Moreover, their consumption cannot be verified bystandard drug tests, which is particularly interesting for peoplefacing regular drugtesting.Easy accessvia the Internetand afford-ability also contribute to the popularity of these drugs.Since their first detection in herbal mixtures,


Forensic Toxicology | 2012

Identification of the cannabimimetic AM-1220 and its azepane isomer (N-methylazepan-3-yl)-3-(1-naphthoyl)indole in a research chemical and several herbal mixtures

Stefan Kneisel; Philippe Bisel; Volker Brecht; Sebastian Broecker; Michael Müller; Volker Auwärter

Recently, a large number of synthetic cannabinoids have been identified in herbal mixtures. Moreover, an even higher number of cannabimimetic compounds are currently distributed as research chemicals on a gram to kilogram scale via several online trading platforms. As this situation leads to a large number of new cannabimimetics and the occurrence of isobaric substances, the analysis of such compounds using mass spectroscopy (MS) involves the risk of incorrect assignments of mass spectra. In certain cases, this leads to considerable analytical challenges. In the majority of cases, these challenges can only be mastered by combining multiple analytical techniques. We purchased a so-called research chemical advertised as the cannabimimetic compound [(N-methylpiperidin-2-yl)methyl]-3-(1-naphthoyl)indole (AM-1220) via an Internet platform. Analysis of the microcrystalline substance using gas chromatography (GC)–MS indicated the presence of pure AM-1220. However, after further purity testing utilizing thin-layer chromatography we were surprised to see an additional spot indicating a mixture of two substances with highly similar physicochemical properties. After isolation, high-resolution mass spectroscopy (HR-MS) revealed an elemental composition of C26H26N2O for both substances, proving the presence of two isobaric substances. Moreover, GC–MS and LC-HR-MS/MS experiments indicated two naphthoylindoles featuring different heterocyclic substituents at the indole nitrogen. Nuclear magnetic resonance spectroscopy verified the presence of the highly potent cannabimimetic AM-1220 and its azepane isomer. Interestingly, only a few weeks after purchasing the powder we also detected both substances in a similar proportion in several herbal mixtures for the first time.


Drug Testing and Analysis | 2014

Analysis of synthetic cannabinoids in abstinence control: Long drug detection windows in serum and implications for practitioners

Stefan Kneisel; Jörg Teske; Volker Auwärter

Controlled studies on the elimination kinetics and the long-term detection of synthetic cannabinoids in humans are lackingand will most probably not become available in the near futurebecause of the unfavorable risk profiles of these substances. Forthis reason, we aim to share our observations on this topic afterhaving analyzed more than 4200 serum samples for syntheticcannabinoids until late 2012. The samples were received frompatients of forensic psychiatric clinics, rehabilitation clinics orwithdrawal treatment centers located in two different regionsof Germany (federal states of Baden-Wurttemberg and Bavariaas well as Lower Saxony). Due to a high prevalence of syntheticcannabinoid use, most of the institutions sent follow-up samplesfrom patients who tested positive by LC-MS/MS analysis.A particularly striking observation was made in a number ofcases in which the widely used synthetic cannabinoids JWH-081,JWH-122 or JWH-210 were detectable for up to 102 days followingself-reported cessation of drug use, leading to estimated terminalelimination half-lives of up to 41 days. Consistent with the claimofabstinenceduringthisperiod,acontinuousdecreaseofserumconcentration levels was noted. This observation raised thepossibility that synthetic cannabinoids may be extensively dis-tributed into deeper compartments (e.g. fat tissue), hence lead-ing to an extended window of detection due to redistributionof these substances into the bloodstream, especially followingheavy consumption. Moreover, our preliminary data suggestthat this effect is even more pronounced than in the case ofΔ


Drug Testing and Analysis | 2013

Stability of 11 prevalent synthetic cannabinoids in authentic neat oral fluid samples: glass versus polypropylene containers at different temperatures.

Stefan Kneisel; Michael Speck; Bjoern Moosmann; Volker Auwärter

Although synthetic cannabinoids have been intensively investigated in recent years and oral fluid testing is becoming increasingly popular in suspected driving under the influence of drugs cases, only scarce data on their stability in authentic neat oral fluid (nOF) samples are yet available. However, especially for these new psychoactive drugs, investigations focusing on stability issues are necessary as inappropriate storage conditions may lead to considerable analytical problems. Since it has been shown for Δ(9) -tetrahydrocannabinol that adsorption to plastic surfaces may lead to considerable drug loss, we aimed to evaluate whether adsorption also has to be taken into account for synthetic cannabinoids in nOF samples. In this paper, the results of investigations on the recovery of 11 prevalent synthetic cannabinoids from authentic nOF samples stored over 72 h in RapidEASE (high quality borosilicate glass) and Sciteck Saliva Split Collector (polypropylene) tubes at 4 and 25 °C are presented. Our findings clearly demonstrate that lipophilic synthetic cannabinoids present in nOF samples adsorb to the surface of polypropylene containers when stored at room temperature, leading to considerable drug loss. Hence, when using polypropylene tubes, samples should be shipped cooled in order to avoid a substantial decrease of the analyte concentration during transportation.


PLOS ONE | 2011

Cannabinoid Receptor 2 Signaling Does Not Modulate Atherogenesis in Mice

Florian Willecke; Katharina Zeschky; Alexandra Ortiz Rodriguez; Christian Colberg; Volker Auwärter; Stefan Kneisel; Melanie Hutter; Andrey Lozhkin; Natalie Hoppe; Dennis Wolf; Constantin von zur Muhlen; Martin Moser; Ingo Hilgendorf; Christoph Bode; Andreas Zirlik

Background Strong evidence supports a protective role of the cannabinoid receptor 2 (CB2) in inflammation and atherosclerosis. However, direct proof of its involvement in lesion formation is lacking. Therefore, the present study aimed to characterize the role of the CB2 receptor in Murine atherogenesis. Methods and Findings Low density lipoprotein receptor-deficient (LDLR−/−) mice subjected to intraperitoneal injections of the selective CB2 receptor agonist JWH-133 or vehicle three times per week consumed high cholesterol diet (HCD) for 16 weeks. Surprisingly, intimal lesion size did not differ between both groups in sections of the aortic roots and arches, suggesting that CB2 activation does not modulate atherogenesis in vivo. Plaque content of lipids, macrophages, smooth muscle cells, T cells, and collagen were also similar between both groups. Moreover, CB2 −/−/LDLR−/− mice developed lesions of similar size containing more macrophages and lipids but similar amounts of smooth muscle cells and collagen fibers compared with CB2 +/+/LDLR−/− controls. While JWH-133 treatment reduced intraperitoneal macrophage accumulation in thioglycollate-illicited peritonitis, neither genetic deficiency nor pharmacologic activation of the CB2 receptor altered inflammatory cytokine expression in vivo or inflammatory cell adhesion in the flow chamber in vitro. Conclusion Our study demonstrates that both activation and deletion of the CB2 receptor do not relevantly modulate atherogenesis in mice. Our data do not challenge the multiple reports involving CB2 in other inflammatory processes. However, in the context of atherosclerosis, CB2 does not appear to be a suitable therapeutic target for reduction of the atherosclerotic plaque.


Current Pharmaceutical Biotechnology | 2018

Metabolism of Nine Synthetic Cannabinoid Receptor Agonists Encountered in Clinical Casework: Major in vivo Phase I Metabolites of AM-694, AM-2201, JWH-007, JWH-019, JWH-203, JWH-307, MAM-2201, UR-144 and XLR-11 in Human Urine Using LC-MS/MS

Melanie Hutter; Sebastian Broecker; Stefan Kneisel; Florian Franz; Simon D. Brandt; Volker Auwärter

BACKGROUND `Herbal mixtures` containing synthetic cannabinoid receptor agonists (SCRAs) are promoted as legal alternative to marihuana and are easily available via the Internet. Keeping analytical methods for the detection of these SCRAs up-to-date is a continuous challenge for clinicians and toxicologists due to the high diversity of the chemical structures and the frequent emergence of new compounds. Since many SCRAs are extensively metabolized, analytical methods used for urine testing require previous identification of the major metabolites of each compound. OBJECTIVE The aim of this study was to identify the in vivo major metabolites of nine SCRAs (AM- 694, AM-2201, JWH-007, JWH-019, JWH-203, JWH-307, MAM-2201, UR-144, XLR-11) for unambiguous detection of a drug uptake by analysis of urine samples. METHOD Positive urine samples from patients of hospitals, detoxification and therapy centers as well as forensic-psychiatric clinics were analyzed by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LCqToF- MS) for investigation of the major in vivo metabolites. RESULTS For all investigated SCRAs, monohydroxylation, dihydroxylation and/or formation of the Nhexanoic/ pentanoic acid metabolites were among the most abundant metabolites detected in human urine samples. Substitution of the fluorine atom was observed to be an important metabolic reaction for compounds carrying an N-(5-fluoropentyl) side chain. N-Dealkylated metabolites were not detected in vivo. CONCLUSION The investigated metabolites facilitate the reliable detection of drug uptake by analysis of urine samples. For distinction between uptake of the fluorinated and the non-fluorinated analogs, the N-(4-hydroxypentyl) metabolite of the non-fluorinated analog was identified as a useful analytical target and consumption marker.


Journal of Mass Spectrometry | 2011

Development and validation of a liquid chromatography-tandem mass spectrometry method for the quantitation of synthetic cannabinoids of the aminoalkylindole type and methanandamide in serum and its application to forensic samples

Sebastian Dresen; Stefan Kneisel; Wolfgang Weinmann; Ralf Zimmermann; Volker Auwärter

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Jürgen Kempf

University Medical Center Freiburg

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Bela Szabo

University of Freiburg

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Maren Hermanns-Clausen

University Medical Center Freiburg

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