Chronic Administration of Δ9-Tetrahydrocannabinol Alters Brain Glucose Uptake and Improves Waiting Impulsivity in the Rat.

Introduction: Δ9-Tetrahydrocannabinol (THC) acts as an agonist at cannabinoid receptors. Its chronic intake affects many behaviors, including cognitive processes. The aims of this study in rats are to assess the chronic effects of THC on impulsivity and on regional brain glucose uptake. Materials and Methods: For the determination of "waiting impulsivity," a total of 20 male Lister Hooded rats were trained to perform a reaction time task, followed by a baseline test of impulsivity and baseline glucose uptake measurements with [18F]-fluoro-2-deoxy-D-glucose and positron emission tomography (PET). Then, 10 rats each received 3 mg/kg THC or vehicle injected intraperitoneally daily for 21 days. Subsequently, a second behavioral test and PET measurements were performed, and blood THC concentrations were determined. Analyses of variance of brain regions of the impulsivity network with the parameter "standardized uptake value" regarding glucose uptake and correlation analyses of the collected parameters were carried out. Discussion: After chronic THC treatment, decreased glucose uptake (p-values <0.05) was found in cingulate cortex, hippocampus, amygdala, thalamus, and cerebellar cortex, as compared with vehicle-treated rats. The number of correct no-go responses (increased waiting time) significantly increased (p<0.05) in THC-treated rats. Furthermore, correct no-go responses correlated positively and strongly with the THC blood concentrations (Spearman's ρ=0.79, p<0.01). Conclusion: These findings reflect a specific reduction in impulsive behavior after chronic THC treatment, showing a functionally relevant influence of THC on "waiting impulsivity" with reduced selective glucose uptake at the same time.

Analysis of tetramisole metabolites - Is "Aminorex" found in forensic samples of cocaine users actually 4-phenyl-2-imidazolidinone?

Phenyltetrahydroimidazothiazole (PTHIT, tetramisole) is a common adulterant in cocaine samples. Little is known about its human metabolism. p-hydroxy-PTHIT has long been the only proven phase-I-metabolite. Another putative metabolite is the stimulant aminorex. However, data on its analytical proof is rare and contradictory. Even less known is its constitutional isomer 4-phenyl-2-imidazolidinone which has only been proven in animal samples so far. The aim of the study was to get insight into the metabolism of PTHIT after controlled nasal uptake of PTHIT and in real forensic cocaine/benzoylecgonine-positive samples. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated for quantification of 4-phenyl-2-imidazolidinone and p-hydroxy-PTHIT (LOQ 0.05 ng/ml each). Selectivity was ensured for 4-phenyl-2-imidazolidinone and aminorex (LOD 0.05 ng/ml). After controlled nasal uptake of tetramisole (10 mg, n = 3) a shorter half-life for p-hydroxy-PTHIT (3.4-5.8 h) was determined than for 4-phenyl-2-imidazolidinone (14.0-15.9 h). p-hydroxy-PTHIT (33%) and 4-phenyl-2-imidazolidinone (51%) were also detected in serum samples from cocaine users tested previously positive for PTHIT (n = 73). Aminorex was never detected. The potential of misinterpreting 4-phenyl-2-imidazolidinone as aminorex was tested using a gas chromatography-mass spectrometry (GC-MS) method used in the literature and an in-house liquid chromatography-time-of-flight mass spectrometry (LC-QTOF) screening-method. Using GC-MS the analysed bis-trimethylsilyl-derivatives cannot be differentiated due to co-elution. Both substances were chromatographically separated using the LC-QTOF method, but library comparison workflows misinterpreted 4-phenyl-2-imidazolidinone as aminorex. It seems likely that aminorex, which was allegedly identified as a metabolite of PTHIT in samples of cocaine users in previous studies, is in fact 4-phenyl-2-imidazolidinone.

Chiral pharmacokinetics of tetramisole stereoisomers-Enantioselective quantification of levamisole and dexamisole in serum samples from users of adulterated cocaine.

Phenyltetrahydroimidazothiazole (PTHIT, tetramisole) is the most frequently used adulterant of cocaine and exists in the two enantiomeric forms levamsiole (S) and dexamisole (R). Existing studies show diverse fractions of samples containing enantiopure levamsiole, levamisole-enriched mixtures, and racemic tetramisole as adulterant. However, blood samples have never been enantioselectively tested for PTHIT. Because enantiomers are usually metabolized stereoselectively, chiral analysis of blood samples can help estimate the time of drug use, provided that a racemic substance is ingested. Therefore, an enantioselective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed using a chiral column. Validation of the method was carried out for methanolic substance samples as well as serum samples and showed satisfactory selectivity, sensitivity, linearity (0.05-100 ng/mL), precision, and accuracy; 151 cocaine samples seized in Germany between 2018 and 2021 were analyzed. Most (94%, n = 48) of the 51 PTHIT-positive samples contained racemic tetramsiole, whereas there were two samples containing levamisole-enriched mixtures and one sample containing nearly enantiopure levamisole. Furthermore, 157 cocaine and/or benzoylecgonine-positive forensic serum samples were tested with cocaine-positive samples showing the highest frequency of PTHIT detection (43%). All positive samples contained either dexamisole alone or (R)/(S)-concentration ratios >1 (1.05-70.6). Finally, a self-administration study was conducted with three subjects taking 10 mg of racemic tetramisole each. Although peak concentrations and corresponding times did not differ significantly between the enantiomers, dexamisole showed significantly longer apparent elimination half-lives (7.02-10.0 h) than levamisole (2.87-4.77 h). The resulting steadily increasing (R)/(S)-ratios can therefore be helpful in estimating the time of cocaine consumption.

Determination of the enantiomeric composition of amphetamine, methamphetamine and 3,4-methylendioxy-N-methylamphetamine (MDMA) in seized street drug samples from southern Germany.

Amphetamine (speed), methamphetamine (crystal meth), and 3,4-methylenedioxy-N-methylamphetamine (MDMA, ecstasy) represent the most frequently abused amphetamine-type stimulants (ATS). Differences in pharmacological potency and metabolism have been shown for the enantiomers of all three stimulants. Legal consequences in cases of drug possession may also differ according to the German law depending on the enantiomeric composition of the seized drug. Therefore, enantioselective monitoring of seized specimens is crucial for legal and forensic casework. Various kinds of samples of amphetamine (n = 143), MDMA (n = 94), and methamphetamine (n = 528) that were seized in southern Germany in 2019 and 2020 were analyzed for their chiral composition using different chromatographic methods. Whereas all samples of amphetamine and MDMA were racemic mixtures, the chiral composition of the methamphetamine specimens was diverse. Although the vast majority (n = 502) was present as (S)-methamphetamine, also specimens containing pure (R)-methamphetamine (n = 7) were found. Furthermore, few samples (n = 8) were of racemic nature or contained non-racemic mixtures of both enantiomers (n = 10). Because methamphetamine appears in varying enantiomeric compositions, any seizure should be analyzed using an enantioselective method. Amphetamine and MDMA, on the other hand, currently appear to be synthesized exclusively via racemic pathways and are not chirally purified. Nevertheless, regular monitoring of the chiral composition should be ensured.

Identification of Potential Distinguishing Markers for the Use of Cannabis-Based Medicines or Street Cannabis in Serum Samples.

Increasing prescription numbers of cannabis-based medicines raise the question of whether uptake of these medicines can be distinguished from recreational cannabis use. In this pilot study, serum cannabinoid profiles after use of cannabis-based medicines were investigated, in order to identify potential distinguishing markers. Serum samples after use of Sativex®, Dronabinol or medical cannabis were collected and analyzed for 18 different cannabinoids, using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Analytes included delta-9-tetrahydrocannabinol, 11-hydroxy-tetrahydrocannabinol, 11-nor-9-carboxy-tetrahydrocannabinol, cannabidiol, cannabinol, cannabigerol, cannabichromene, cannabicyclol, tetrahydrocannabivarin, cannabidivarin, tetrahydocannabinolic acid A, cannabidiolic acid, cannabinolic acid, cannabigerolic acid, cannabichromenic acid, cannabicyclolic acid, tetrahydrocannabivarinic acid and cannabidivarinic acid. Cannabinoid profiles of study samples were compared to profiles of street cannabis user samples via principal component analysis and Kruskal-Wallis test. Potential distinguishing markers for Dronabinol and Sativex® intake were identified, including 11-hydroxy-tetrahydrocannabinol/delta-9-tetrahydrocannabinol ratios ≥1 and increased concentrations of 11-nor-9-carboxy-tetrahydrocannabinol, cannabidiol or cannabichromene. Larger quantities of minor cannabinoids suggested use of cannabis. Use of medical and street cannabis could not be distinguished, except for use of a cannabidiol-rich strain with higher cannabidiol/delta-9-tetrahydrocannabinol and cannabichromene/delta-9-tetrahydrocannabinol ratios. Findings of the study were used to classify forensic serum samples with self-reported use of cannabis-based medicines.

Light ion production for a future radiobiological facility at CERN: preliminary studies.

Recent medical applications of ions such as carbon and helium have proved extremely effective for the treatment of human patients. However, before now a comprehensive study of the effects of different light ions on organic targets has not been completed. There is a strong desire for a dedicated facility which can produce ions in the range of protons to neon in order to perform this study. This paper will present the proposal and preliminary investigations into the production of light ions, and the development of a radiobiological research facility at CERN. The aims of this project will be presented along with the modifications required to the existing linear accelerator (Linac3), and the foreseen facility, including the requirements for an ion source in terms of some of the specification parameters and the flexibility of operation for different ion types. Preliminary results from beam transport simulations will be presented, in addition to some planned tests required to produce some of the required light ions (lithium, boron) to be conducted in collaboration with the Helmholtz-Zentrum für Materialien und Energie, Berlin.

Direct ELISA kits as a sensitive and selective screening method for abstinence control in urine.

In 2009 cutoff values of assessment criteria to testify abstinence control in order to estimate driving ability were standardized in Germany. The cutoff values are lower than required in existing guidelines like SAMHSA and there is critical discussion about detection of low concentrations by using immunoassay, especially concerning amphetamines in urine (50 ng/ml). In this study Direct ELISA kits were tested for their applicability to identify the absence of amphetamines, cannabinoids, opiates, cocaine, methadone and benzodiazepines in urine. Results were confirmed by LC/MS or GC/MS analyses. Sensitivity, specificity, predictive values (positive as well as negative) and overall misclassification rates were evaluated by contingency tables and were compared to ROC-analyses. Sensitivity results as well as specificity results were satisfying showing sensitivity values higher than 96% for each analyte. The amphetamine test we used showed sensitivity and specificity of 100% and 88%, respectively, even if amphetamine tests usually react with high cross-reactivity. Our study results include high discrimination at required cutoff values between positives and negatives for each drug group and demonstrate that immunological tests complying with requirements of current decreased urine cutoff values for assessment of driving ability do exist.

[Interpretation of blood analysis data found after passive exposure to cannabis]. / Interpretation analytischer Befunde in Blutproben bei passiver Cannabisexposition.

When defendants are confronted with evidence of cannabinoids in their blood suggesting consumption of cannabis they sometimes argue that this could only be due to a passive exposure. The small number of controlled studies available showed that tetrahydrocannabinol (THC), the active ingredient of cannabis, was actually found in the blood after passive exposure to cannabis smoke. The resulting blood concentrations were dependent on the applied THC doses and the size of the room in which the passive exposure occurred. However, the quantitative data indicated in the publications of the 1980s cannot be fully compared with the results of modern analytical methods. Due to the rapid distribution of THC in the body, which occurs also after passive exposure to low doses, the THC concentration in serum to be expected in a blood sample taken 1 hour after exposure is less than 1 ng/mL. For assessment of an alleged passive exposure, the metabolic THC-carboxylic acid, which is excreted more slowly, must also be taken into account. After passive exposure, similar and very low serum concentrations of THC and THC-carboxylic acid are to be expected (< 2 ng/mL), while higher blood levels suggest the deliberate consumption of a psychoactive dose.

A fatal paramethoxymethamphetamine intoxication.

During the last years in Germany a marked increase in the use of amphetamines such as 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has been observed. The use of these recreational drugs is especially common among young people participating in rave parties. Occasionally ring-methoxylated phenethylamine derivatives like paramethoxymethamphetamine (PMMA) or paramethoxyamphetamine (PMA) are found in street drugs offered as ecstasy. These compounds exhibit a higher toxicity than the methylenedioxyamphetamine derivatives. We report on the death of a 22-year-old man after the ingestion of ecstasy pills containing PMMA and PMA. The PMMA concentration in femoral blood was 0.85 mg/l. Besides PMA (0.61 mg/l), amphetamine (0.21 mg/l), benzoylecgonine (<0.01 mg/l) and ethanol (0.46 per thousand ) were found in the blood. The case reflects the well-known fact that street drugs offered as ecstasy pills contain not necessarily MDMA but frequently differ in composition even if they have the same logo. Users of these pills therefore always take the risk of consuming pills with dangerous life-threatening ingredients. In many laboratories paramethoxyamphetamines are not detectable in routine analytical procedures. If the cause of an intoxication cannot be discovered by analytical routine methods, rarely occurring designer drugs such as PMA or PMMA should also be kept in mind.