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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Qualitative Detection of Selected Designer Drugs and Relevant Metabolites in Environmental Water Samples

Pruyn, Marley 14 July 2016 (has links)
Designer drugs are compounds which have been synthetically derived from illicit drugs. After consumption, drugs and their metabolites are introduced into the sewage water which is treated and disposed into the environment. A combined target, suspect and non-target workflow was created to detect designer drugs in environmental water samples. Multiple water samples were spiked with an unknown mixture of drugs and metabolites to assess the efficiency of the method. Samples were collected from sewage influent and effluent pipes, downstream from a sewage outfall and reclaimed water. Analysis was conducted with high resolution MS using the QExactive Orbitrap. Screening was performed using a database compiled in-house using TraceFinder EFS. Structure confirmation was achieved using MassFrontier. Target drugs and their metabolites were detected in sewage influent but not in sewage effluent, downstream of the effluent pipe, or in reclaimed water. The workflow was adequate to detect designer drugs in multiple water matrices at concentrations as low as 20ppt.
2

Synthetic Cannabinoid Usage among College Students: The Example of K2 and Spice

Stephens, Jason L. 08 1900 (has links)
The primary goal of this study was to investigate the awareness and prevalence of Spice and K2 usage among a population of college students, as well as the demographics of such users. The study also sought to determine whether or not students prefer these products over natural cannabis, in addition to examining the most popular methods of obtainment and the most commonly reported side effects of K2 and Spice usage. Participants consisted of 643 undergraduate students enrolled at the University of North Texas during the fall 2011 semester. Findings indicate that while students exhibit a relatively high awareness of K2 and Spice, usage of these products is not a prevalent occurrence. Implications of the findings are discussed.
3

Investigation in stability of eight synthetic piperazines in human whole blood under various storage conditions over time

Lau, Timothy Wan Tsun 13 July 2017 (has links)
Over the past decade, synthetic piperazines have been associated with multiple fatalities and was one of the top 25 identified drugs in 2011. While circumventing legislative controls and preventing the detection in standard drug tests, synthetic piperazine derivatives are encountered in forensic casework as “legal” alternatives to ecstasy (3,4-methylenedioxymethamphetamine). These chemically-produced compounds share very similar pharmacological and psychological effects with ecstasy which in turn has led to their popularity as “party pills”. The long-lasting duration of synthetic piperazines, especially when 1-benzylpiperazine (BZP) is mixed with 1-(3-trifluoromethylphenyl)-piperazine (TFMPP), has also made them desirable to drug users to receive enhanced hallucinogenic effects. Although most methods are optimized to accurately quantify the amount of drugs in biological specimens submitted for forensic toxicology testing, unforeseeable challenges may arise to complicate the analysis such as postmortem redistribution, enzymatic reactions, the presence of bacterial activities, chemical and matrix interferences as well as the lack of reference materials. Thus, the purpose of this research was to investigate the stability of synthetic piperazines in human whole blood under various storage conditions and time ranges. A total of eight synthetic piperazines were assessed on their degrees of degradation using a Shimadzu Ultra-Fast Liquid Chromatography (UFLC) with SCIEX 4000 Q-Trap Electrospray Ionization Tandem Mass Spectrometry in positive ionization mode. These analytes included: 1-benzylpiperazine (BZP), 1-(4-fluorobenzyl)-piperazine (FBZP), 1-(4-methylbenzyl)-piperazine (MBZP), 1-(4-methoxyphenyl)-piperazine (MeOPP), 1-(para-fluorophenyl)-piperazine (pFPP), 1-(3-chlorophenyl)-piperazine (mCPP), 2,3-dichlorophenylpiperazine (DCPP), and 1-(3-trifluoromethylphenyl)-piperazine (TFMPP). Individual unknown samples were prepared by spiking certified reference standards (Cayman Chemical, Ann Arbor, MI, U.S.A.) of each synthetic piperazine into certified drug-free human whole blood (UTAK Laboratories, Inc., Valencia, CA, U.S.A.) independently at 1000 ng/mL. To closely monitor the stability of each compound and potential drug-drug interactions, mixed samples consisted of all eight piperazines were also stored at room temperature (~20°C), 4°C and -20°C for one, three, six, nine and twelve months in dark sealed containers. Solid phase extraction (SPE) was performed to remove unwanted components prior to the injection into the LC system. Drug of Abuse (DAU) mixed-mode copolymeric columns (Clean Screen®, UCT Inc., Levittown, PA, U.S.A.) were utilized with a positive pressure manifold rack followed by evaporating to dryness with low heat at 65°C. All samples were then reconstituted with 250 µL of 50:50 mixture of methanol and 2mM ammonium formate buffer with 0.2% formic acid (Fisher Scientific, Waltham, MA, U.S.A.). Analysis was performed in triplicate using a reversed-phase column (Kinetex® F5, Phenomenex®, Torrance, CA, U.S.A.) with a binary gradient of a 2mM ammonium formate buffer with 0.2% formic acid and methanol with 0.1% formic acid. The total run time was 11.5 minutes including equilibration and the flow rate was 0.4 mL/min. Three internal standards including BZP-d7, mCPP-d8 and TFMPP-d4 (Cerilliant, Round Rock, TX, U.S.A) were used to generate calibration curves that were ranged from 20 ng/mL to 2000 ng/mL. Results revealed that BZP, MBZP and FBZP were more stable than phenyl piperazines over time under all storage conditions, in which MBZP was consistently more stable and still had more than 70% remaining after 12 months. Data showed a smaller degree of degradation when samples were kept frozen or refrigerated; whereas storing at room temperature should be avoided to ensure minimal degradation and detrimental impacts on stability of piperazine compounds. For crime laboratories that are facing backlog situations, case samples with synthetic piperazines should be kept frozen or refrigerated even for time period as short as 30 days or less. However, storing them for too long will clearly affect the quantitation accuracy because phenyl piperazines are more susceptible to degrade completely after six months regardless of storage conditions. Additionally, matrix interference was present due to the outlier of MBZP quantified on Day 270. Drug-drug interaction was also observed in the analyte mixture but the exact stability pattern of phenyl piperazines when mixed together could not be determined from this data set alone due to discrepancies observed on Day 91 and 270. This research project had shown a solid method to examine how quickly or slowly synthetic piperazines degrade in blood at different storage conditions. To further this study, it would be also important to evaluate the number of freeze-thaw cycles on each specimen in order to minimize the effect of non-metabolic degradation.
4

Česká a polská právní úprava trestní odpovědnosti za drogové delikty / Czech and Polish legal regulation of criminal liability for drug offenses

Rosůlek, Adéla January 2019 (has links)
The dissertation thesis about Czech and Polish legislation on drug offenses deals with driving under the influence of addictive substances, responsibility for acts committed under the influence of addictive substances, drug possession, cannabis cultivation, production and distribution of drugs, handling of articles for drug production and spreading drug addiction. The aim of this work is to bring a critical view of the current Czech legislation on drug offenses and related issues and then to present specific legislative proposals based on comparison with Polish law. The thesis analyzes the Polish and Czech legal regulations of drug offenses and brings a comparison of the facts of the aforementioned crimes and specific case studies. The work is based on legal regulations and case law of both countries, practical knowledge and also available statistical data. The thesis deals with the legalization of drugs comprehensively, including the arguments for and against legalization, wich are used in the Czech Republic and Poland. It addresses the legalization of cannabis on the example of Holland, the USA and Uruguay, as well as the availability of hard drugs in substitution programs in the Czech Republic and Poland. In conclusion the thesis gets to the explanation how the Czech legislator should proceed...
5

Deciphering and modulating G protein signalling in C. elegans using the DREADD technology

Prömel, Simone, Fiedler, Franziska, Binder, Claudia, Winkler, Jana, Schöneberg, Torsten, Thor, Doreen 28 July 2016 (has links) (PDF)
G-protein signalling is an evolutionary conserved concept highlighting its fundamental impact on developmental and functional processes. Studies on the effects of G protein signals on tissues as well as an entire organism are often conducted in Caenorhabditis elegans. To understand and control dynamics and kinetics of the processes involved, pharmacological modulation of specific G protein pathways would be advantageous, but is difficult due to a lack in accessibility and regulation. To provide this option, we designed G protein-coupled receptor-based designer receptors (DREADDs) for C. elegans. Initially described in mammalian systems, these modified muscarinic acetylcholine receptors are activated by the inert drug clozapine N-oxide, but not by their endogenous agonists. We report a novel C. elegans-specific DREADD, functionally expressed and specifically activating Gq-protein signalling in vitro and in vivo which we used for modulating mating behaviour. Therefore, this novel designer receptor demonstrates the possibility to pharmacologically control physiological functions in C. elegans.
6

Comprehensive Forensic Toxicological Analysis of Designer Drugs

Swortwood, Madeleine Jean 21 October 2013 (has links)
New designer drugs are constantly emerging onto the illicit drug market and it is often difficult to validate and maintain comprehensive analytical methods for accurate detection of these compounds. Generally, toxicology laboratories utilize a screening method, such as immunoassay, for the presumptive identification of drugs of abuse. When a positive result occurs, confirmatory methods, such as gas chromatography (GC) or liquid chromatography (LC) coupled with mass spectrometry (MS), are required for more sensitive and specific analyses. In recent years, the need to study the activities of these compounds in screening assays as well as to develop confirmatory techniques to detect them in biological specimens has been recognized. Severe intoxications and fatalities have been encountered with emerging designer drugs, presenting analytical challenges for detection and identification of such novel compounds. The first major task of this research was to evaluate the performance of commercially available immunoassays to determine if designer drugs were cross-reactive. The second major task was to develop and validate a confirmatory method, using LC-MS, to identify and quantify these designer drugs in biological specimens. Cross-reactivity towards the cathinone derivatives was found to be minimal. Several other phenethylamines demonstrated cross-reactivity at low concentrations, but results were consistent with those published by the assay manufacturer or as reported in the literature. Current immunoassay-based screening methods may not be ideal for presumptively identifying most designer drugs, including the “bath salts.” For this reason, an LC-MS based confirmatory method was developed for 32 compounds, including eight cathinone derivatives, with limits of quantification in the range of 1-10 ng/mL. The method was fully validated for selectivity, matrix effects, stability, recovery, precision, and accuracy. In order to compare the screening and confirmatory techniques, several human specimens were analyzed to demonstrate the importance of using a specific analytical method, such as LC-MS, to detect designer drugs in serum as immunoassays lack cross-reactivity with the novel compounds. Overall, minimal cross-reactivity was observed, highlighting the conclusion that these presumptive screens cannot detect many of the designer drugs and that a confirmatory technique, such as the LC-MS, is required for the comprehensive forensic toxicological analysis of designer drugs.
7

Herbal Marijuana Alternatives Investigation: K2 and Spice: A Masters Thesis

Rosenbaum, Christopher D. 30 December 2011 (has links)
Background Herbal marijuana alternatives (HMA), legal plant products adulterated with synthetic cannabinoid receptor agonists, represent a growing public health concern. Only a few case reports describe HMA and synthetic cannabinoid’s clinical toxicity. We describe an outbreak of HMA abuse primarily in the Midwest, the clinical presentation of HMA toxicity, and clinical and forensic testing. Methods During the course of ongoing surveillance for emerging drugs of abuse between November 2009 and August 2010, we retrospectively and prospectively identified a convenience sample comprising 81 cases of abuse of HMA products. Subject demographics, vital signs, lab results and urine were obtained (when available) and tested via gas chromatography mass spectrometry (GCMS) analysis. Samples of HMAs and synthetic cannabinoids were also analyzed via GCMS. Results HMA users were predominantly young males who inhaled HMAs. Analysis of their urine detected synthetic cannabinoid parent compound in one subject. GCMS analysis of synthetic cannabinoids established a reference library that confirmed the presence of synthetic cannabinoids in sampled HMA products. Conclusion HMA products were available in head shops, gas stations, and via the Internet. We have confirmed the presence of synthetic cannabinoids in these HMA products. The tachycardia, hypertension, agitation, anxiety, vomiting and hallucinations observed in this convenience sample are not readily explained by the presence of synthetic cannabinoids acting on CB1 and CB2 receptors. Further research must be done on HMA products and their abusers.
8

In vitro cellular models for neurotoxicity studies : neurons derived from P19 cells

Popova, Dina January 2017 (has links)
Humans are exposed to a variety of chemicals including environmental pollutants, cosmetics, food preservatives and drugs. Some of these substances might be harmful to the human body. Traditional toxicological and behavioural investigations performed in animal models are not suitable for the screening of a large number of compounds for potential toxic effects. There is a need for simple and robust in vitro cellular models that allow high-throughput toxicity testing of chemicals, as well as investigation of specific mechanisms of cytotoxicity. The overall aim of the thesis has been to evaluate neuronally differentiated mouse embryonal carcinoma P19 cells (P19 neurons) as a model for such testing. The model has been compared to other cellular models used for neurotoxicity assessment: retinoic acid-differentiated human neuroblastoma SH-SY5Y cells and nerve growth factor-treated rat pheochromocytoma PC12 cells. The chemicals assessed in the studies included the neurotoxicants methylmercury, okadaic acid and acrylamide, the drug of abuse MDMA (“ecstasy”) and a group of piperazine derivatives known as “party pills”. Effects of the chemicals on cell survival, neurite outgrowth and mitochondrial function have been assessed. In Paper I, we describe a fluorescence-based microplate method to detect chemical-induced effects on neurite outgrowth in P19 neurons immunostained against the neuron-specific cytoskeletal protein βIII-tubulin. In Paper II, we show that P19 neurons are more sensitive than differentiated SH-SY5Y and PC12 cells for detection of cytotoxic effects of methylmercury, okadaic acid and acrylamide. Additionally, in P19 neurons and differentiated SH-SY5Y cells, we could demonstrate that toxicity of methylmercury was attenuated by the antioxidant glutathione. In Paper III, we show a time- and temperature-dependent toxicity produced by MDMA in P19 neurons. The mechanisms of MDMA toxicity did not involve inhibition of the serotonin re-uptake transporter or monoamine oxidase, stimulation of 5-HT2A receptors, oxidative stress or loss of mitochondrial membrane potential. In Paper IV, the piperazine derivatives are evaluated for cytotoxicity in P19 neurons and differentiated SH-SY5Y cells. The most toxic compound in both cell models was TFMPP. In P19 neurons, the mechanism of action of TFMPP included loss of mitochondrial membrane potential. In conclusion, P19 neurons are a robust cellular model that may be useful in conjunction with other models for the assessment of chemical-induced neurotoxicity.
9

Analysis of Synthetic Cannabinoids by Direct Analysis in Real Time Quadrupole Time-of-Flight Mass Spectrometry and Gas Chromatography Quadrupole Time-of-Flight Mass Spectrometry

Torbet, Tyler S 01 June 2015 (has links)
The aim of this study was to investigate the utility of direct analysis in real time quadrupole time-of-flight mass spectrometry and gas chromatography quadrupole time-of-flight mass spectrometry in the analysis of 162 different synthetic cannabinoids. Direct analysis in real time quadrupole time-of-flight mass spectrometry is shown to be a rapid and accurate analytical method for synthetic cannabinoids. Spectra can be generated with less than 1.5 ng of the drug in under a minute and be successfully searched against previously generated ESI-QTOF libraries in most cases (118/130 drugs tested) as well as can also be applied to the identification of synthetic cannabinoids in a mixture. Gas chromatography quadrupole time-of-flight mass spectrometry, while requiring a much longer analysis time, is shown to accurately distinguish all but 19 compounds (140/159). These two instruments have proven to be viable alternatives in synthetic cannabinoid analysis and will greatly benefit forensic laboratories.
10

Deciphering and modulating G protein signalling in C. elegans using the DREADD technology

Prömel, Simone, Fiedler, Franziska, Binder, Claudia, Winkler, Jana, Schöneberg, Torsten, Thor, Doreen January 2016 (has links)
G-protein signalling is an evolutionary conserved concept highlighting its fundamental impact on developmental and functional processes. Studies on the effects of G protein signals on tissues as well as an entire organism are often conducted in Caenorhabditis elegans. To understand and control dynamics and kinetics of the processes involved, pharmacological modulation of specific G protein pathways would be advantageous, but is difficult due to a lack in accessibility and regulation. To provide this option, we designed G protein-coupled receptor-based designer receptors (DREADDs) for C. elegans. Initially described in mammalian systems, these modified muscarinic acetylcholine receptors are activated by the inert drug clozapine N-oxide, but not by their endogenous agonists. We report a novel C. elegans-specific DREADD, functionally expressed and specifically activating Gq-protein signalling in vitro and in vivo which we used for modulating mating behaviour. Therefore, this novel designer receptor demonstrates the possibility to pharmacologically control physiological functions in C. elegans.

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