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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.
21

Neurodevelopment Liabilities of Substance Abuse

Palomo, T., Archer, T., Beninger, R. J., Kostrzewa, R. M. 01 June 2002 (has links)
The perinate is particularly risk-prone to chemical species which have the potential of inducing neuronal apoptosis or necrosis and thereby adversely altering development of the brain, to produce life-long functional and behavioral deficits. This paper is an overview for many substances of abuse, but the purview is much more broadened by the realization that even elevated levels of estrogens and corticosteroids in the pregnant mother can act as neuroteratogens, by passing via the placenta and altering neural development or inducing apoptosis in the perinate. Finally, therapeutic risks of anesthetics are highlighted, as these too induce neuronal apoptosis in the neonate by either blocking N-methyl-D-aspartate receptors or by acting as gamma-aminobutyric acid agonists. By understanding the mechanisms involved it may ultimately be possible to interrupt the mechanistic scheme and thereby prevent neuroteratological processes.
22

Delivering Therapeutic Cannabinoids via Skin: Current State and Future Perspectives

Tijani, Akeemat O., Thakur, Divya, Mishra, Dhruv, Frempong, Dorcas, Chukwunyere, Umeh I., Puri, Ashana 10 June 2021 (has links)
Adequate evidence exists in the literature indicating a relatively positive shift with regards to the legal acceptance of cannabis and cannabis-derived products for medicinal purposes in some countries. Concomitantly, scientists are showing renewed interest in cannabis-related research work. Over the years, clinical and preclinical studies have demonstrated the therapeutic significance of cannabinoids for diverse indications. Additionally, efforts are being made to develop cannabis-related products into acceptable prescription products. FDA authorization for the commercial use of four cannabinoid-derived products, available as oral dosage forms is a significant progress already. However, there are certain drawbacks associated with the conventional delivery forms of cannabinoids. These include low oral bioavailability due to hepatic degradation, gastric instability, poor water solubility, and the side effects experienced upon the use of high doses of psychotropic cannabinoids associated with heightened plasma concentrations of the drug. These are however, limitable with the aid of transcutaneous drug delivery. Emerging topical and transdermal strategies could be exploited for the successful development of highly effective delivery systems for cannabinoids. This review discusses the feasibility of delivering therapeutic cannabinoids via skin and provides a comprehensive account of the supporting research studies that have been reported in the literature till date.
23

Studying and Modifying Paper to Lower Detection Limits for Paper Spray Mass Spectrometry

Bills, Brandon John 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In this work we developed paper spray mass spectrometry methods to obtain lower detection limits for pharmaceuticals and drugs of abuse. The second chapter investigates blood fractionation membranes for their ability to obtain lysis free plasma from whole blood without changing the drug concentration relative to centrifugation. We presented a device capable of obtaining and analyzing plasma samples from whole blood and obtaining quantitative results similar to traditional methods. In the third chapter the properties of the paper substrate are investigated systematically for their impacts on ionization efficiency and recovery in combination with the solvent choice. The fourth and fifth chapters detail a simple method for lowering detection limits using a method called paper strip extraction. In this method biofluids are wicked through either sesame seed oil or solid phase extraction powder on a paper strip to concentrate and preserve (in the case of THC) analytes out of biofluids. The use of 3D printing for rapid prototyping and how it potentially impacts paper spray MS sensitivity is outlined in the final chapter.
24

The Implications of Delta-9-tetrahydrocannabinol on Localized Immune and Hormonal Responses Mediated by Trophoblasts of the Human Placenta

Gurm, Harmeet January 2021 (has links)
Over the approximate nine months of its intrauterine existence, the development of the fetus is supported by the human placenta. This transient organ is central to pregnancy success as it facilitates maternal-fetal exchange, immunological tolerance, and hormone production. Villous trophoblasts mediate placental formation by engaging in a continuous turnover process of proliferation, differentiation, fusion, and apoptosis. In doing so, cytotrophoblasts and syncytiotrophoblasts maintain the integrity of the outer placental lining known as the syncytium. Exposure to drugs, however, can compromise placental establishment, which can in turn adversely impact pregnancy and fetal health. Specifically, cannabis is widely used by women of reproductive age and during pregnancy. While maternal cannabis use is linked to poor outcomes such as preterm birth and neurodevelopmental delays in exposed children, the underlying mechanisms are not well-defined. First, we characterized a functionally relevant cell line to model differentiation and fusion. In a comparison of the BeWo and BeWo b30 cell lines, our findings demonstrated that both models similarly undergo fusion. We then explored the implications of exposure to delta-9- tetrahydrocannabinol (∆9-THC) on the immunological roles of villous trophoblasts. We observed that cytotrophoblast differentiation and fusion were associated with localized inflammation due to elevated interleukin-2 (IL-2) and tumour necrosis factor-alpha (TNF-α) but inhibited interleukin-4 (IL-4) and interleukin-10 (IL-10) production. ∆9-THC exposure impaired this T helper 1/2 cytokine balance through decreased IL-2 and TNF-α as well as increased IL-4 and IL-10 levels. Subsequently, we investigated the effects of ∆9-THC in TNF-α- and IL-10-dominant environments, to represent inflammatory and immunomodulatory microenvironments, respectively. Coincident with inflammation, ∆9-THC attenuated trophoblast fusion and the biosynthesis of steroid hormones, progesterone and cortisol, through perturbed cytochrome P450 regulation. This thesis ultimately lays a foundation for understanding how cannabis use during pregnancy may compromise the fusogenic, immune and endocrine functions of villous trophoblasts in the placenta. / Thesis / Master of Science (MSc) / The human placenta is a pregnancy-specific organ that supports the health of the mother- to-be and fetus. Stem cells known as cytotrophoblasts undergo differentiation and fusion to support the establishment of the syncytium, which creates a boundary that separates the maternal and fetal circulations. In the case of cannabis consumption during pregnancy, its biologically active components can travel to the placenta, cross the syncytium, and enter fetal blood. Our primary objective was to determine how cannabis exposure can impact the formation and maintenance of the syncytium. While maternal use has been linked to short- and long-term consequences for child health, existing research lacks a complete understanding of the underlying mechanisms. We demonstrate that cannabis exposure alters the production of important immune and hormonal factors during cytotrophoblast fusion, which may play a role in mediating poor placental development. Ultimately, it is critical to explore the implications of cannabis use for female reproductive health due to a rising trend in its use.
25

Recovery of THC from Oral Fluid: Comparison of Filters in Glass and Plastic Filtration Vials and Evaluation of Quiksal™ and Quantisal™

Dixon, Seth 15 May 2023 (has links)
No description available.
26

Dabbing-Induced Hypersensitivity Pneumonitis

Haddad, Ibrahim, Al-Ghzawi, Farah, Karakattu, Sajin M., Musa, Rasheed G., Hoskere, Girendra 01 July 2021 (has links)
Dabbing has been gaining popularity among young people in recent years due to its ability to deliver a high concentration of tetrahydrocannabinol. When produced illegally, it is usually contaminated by toxic substances and associated with multiple health hazards. We present the case of a 66-year-old woman who developed hypersensitivity pneumonitis after dabbing butane hash oil for the first time and was successfully treated with corticosteroids with complete resolution of her symptoms. This case report emphasizes the respiratory complications associated with using a noxious substance like butane hash oil and gives physicians an insight into the diagnosis and management of dabbing-induced hypersensitivity pneumonitis.
27

THE EFFECTS OF EARLY-LIFE LEAD EXPOSURE ON ADULT DELTA-9-TETRAHYDROCANNABINOL SENSITIVITY, SELF-ADMINISTRATION, AND TOLERANCE

Daniel Garcy (13162236) 08 September 2022 (has links)
<p>Environmental exposure to lead (Pb) and cannabis use are two of the largest public health issues facing modern society in the United States and around the world. Exposure to Pb in early life has been unequivocally shown to have negative impacts on development, and recent research is mounting showing that it may also predispose individuals for risk of developing substance use disorders (SUD). At the same time, societal and legal attitudes towards cannabis (main psychoactive component delta-9-tetrahydrocannabinol) have been shifting, and many American states have legalized the recreational use of cannabis. It is also the 3<sup>rd </sup>most widely used drug of abuse in the US, and rates of cannabis use disorder are on the rise. This thesis sets out to establish whether there is a link between early life Pbexposure and later THC-related behavior in C57BL6/J mice, as has been demonstrated for other drugs of abuse. The first aim seeks to answer whether Pbexposure affects physiological THC sensitivity (as measured by the cannabinoid-induced tetrad). The secondaimseeks to answer whether Pbexposure affects edible THC self-administration and the development of THC tolerance (also measured by the tetrad).It was hypothesized that Pbexposure would decrease THC sensitivity (Aim 1), would enhance THC self-administration (Aim 2), enhance the development of THC tolerance (Aim 2), and finally that sex-dependent effects of Pb-exposure and THC would be observed (Aims 1 & 2). These hypotheses ended up not being supported, but Aim 1 produced findings indicating that THC sensitivity was increased by Pbexposure, but only in female mice. Future researchwill hopefully be able to fully explore the implications of these findings.</p>
28

Application of modeling-based approaches to study the pharmacokinetics and pharmacodynamics of Delta-9-tetrahydrocannabinol (THC) and its active metabolite

Awasthi, Rakesh 01 January 2017 (has links)
The medical use of marijuana is increasing, yet little is known about the exposure-response relationships resulting in its psychoactive effects. Δ9-tetrahydrocannabinol (THC) and its active metabolite (11-hydroxy-THC; THC-OH) are the principal psychoactive components in marijuana. It is well known that the plasma concentrations of the psychoactive components of marijuana do not directly relate to the observed psychoactive effects. The presence of a counter-clockwise hysteresis in the plasma concentrations-effect plot demonstrates a temporal delay between the plasma concentrations and observed effect following the intravenous administration of THC. The overarching objective of this research was to better understand the relationship between the plasma and brain concentrations of the psychoactive components (THC and THC-OH) and the observable psychoactive effects after intravenous administration of THC, utilizing model-based approaches. Specifically, the pharmacokinetics were explored using population pharmacokinetic (Pop PK) and physiologically-based pharmacokinetic (PBPK) modeling whereas the pharmacodynamics (PD) of the psychoactive effect (“highness”) were explored using effect-compartment modeling and linking the PD to the PBPK-derived concentrations predicted in the brain and an assumed effect-site. A “hypothetical” effect compartment model was developed to characterize the observed delay in peak “highness” ratings. A direct relationship was established between the reported psychoactive effects (“highness” or intoxication) and the predicted effect-site concentrations of both components (THC and THC-OH) using this effect-compartment modeling approach. The faster plasma to effect compartment equilibration for THC-OH indicated a more rapid equilibration of the active metabolite between plasma and the effect-site (biophase) than for the parent THC. In addition, a PBPK modeling approach was pursued to predict and relate the brain concentrations of THC and THC-OH to the psychoactive effect. The relationship between the effect and the predicted unbound brain concentration of THC indicated an indirect relationship, suggesting a temporal delay between brain concentrations of THC and observed effect. However, a direct relationship was observed between the observed effect and the unbound brain THC-OH concentrations. In addition, the unbound concentrations of THC-OH in the brain were predicted to be higher than the corresponding THC concentrations. These findings highlight the importance for the inclusion of THC-OH, in addition to THC, when relating the observed effect to the concentrations of the psychoactive components of marijuana. These models contribute to the understanding of the PK-PD relationships associated with marijuana use and are important steps in the prediction of the pharmacodynamic effects related to the psychoactive components in marijuana and establish an approach for investigating other THC-related effects.
29

Role of the Endocannabinoid System in Extinction of Learned Behaviours Motivated by Opioid-Induced Reward and Aversion in Rats

Manwell, Laurie 26 August 2013 (has links)
Recent evidence suggesting that the endogenous cannabinoid (ECB) system can be selectively manipulated to facilitate or impair the extinction of learned behaviours — specifically regarding drug-induced aversive memories — has important consequences for research on opiate withdrawal and abstinence. Data presented here support and expand previous findings that the ECB system has an important function in the extinction of aversively motivated behaviors and is mediated by i) an increase in available endogenous CB1 receptor agonists, primarily anandamide, and ii) the exogenous CB1 receptor agonist Δ9-THC, in a manner that is dependent upon both the dose and route of administration. Experiments demonstrated that the fatty acid amide hydrolase (FAAH) inhibitor, URB597, which blocks deactivation of endogenous CB1 ligands, such as anandamide, significantly facilitated extinction of naloxone-precipitated morphine withdrawal-induced conditioned cue aversion, whereas the CB1 receptor antagonist/inverse agonist SR141716 significantly impaired extinction. Several experiments demonstrated that neither the CB1 antagonist AM251 nor the FAAH inhibitor URB597 had any effect on extinction learning for morphine-induced conditioned cue preference. A method was developed for analysing cannabinoid levels in blood by liquid chromatography/mass spectrometry (LC/MS) to compare bioavailable levels of Δ9-THC and its primary psychoactive metabolite. Experiments were designed to meet three primary objectives: 1) to provide further support for the role of the ECB system in the extinction of aversively-motivated behaviours, 2) to compare bioavailable levels of Δ9-THC and its primary psychoactive metabolite, 11-OH-Δ9-THC, after pulmonary and parenteral administration, and 3) to demonstrate that the route of administration of Δ9-THC can have a significant impact on whether or not it facilitates or impairs extinction learning. Results showed that inhaled Δ9-THC dose- and time-dependently facilitated rates of extinction learning of the conditioned aversion whereas injected Δ9-THC significantly impaired extinction. These data suggest that the route of administration of Δ9-THC has important consequences for its resulting pharmacokinetic and behavioural effects, specifically, that pulmonary exposure facilitates, whereas parenteral exposure impairs, rates of extinction learning for conditioned cue aversion. Thus, pulmonary administration of Δ9-THC may prove more beneficial for pharmacological potentiation of extinction learning for aversive memories, such as those supporting drug-craving/seeking in opiate withdrawal-syndrome. / NSERC and OGS
30

Estudo do comportamento eletroquímico do 9-tetraidrocanabinol derivatizado com Fast Blue B / Study of electrochemical behavior of 9-tetrahydrocannabinol derivatizated with Fast Blue B

Balbino, Marco Antonio 29 October 2014 (has links)
A maconha é a droga ilícita mais consumida no mundo, tem como substância psicoativa o delta-9-tetraidrocanabinol (9-THC). Os testes colorimétricos são normalmente realizados em amostras de maconha (e para qualquer outra droga ilícita) apreendidas. A adição de reagentes específicos em uma solução de extrato de maconha pode indicar a presença de substância ilícita mediante mudança de cor. No entanto, a literatura recentemente tem relatado ocorrências de resultados falso-positivos quando os testes colorimétricos são aplicados em algumas folhagens de diversas espécies de plantas. Este estudo utilizou as técnicas voltamétricas em meio orgânico N-N-dimetilformamida utilizando tetrafluoroborato de tetrabutilamônio como eletrólito de suporte e eletrodos de trabalho de disco de carbono vítreo e platina. Aplicando-se um potencial de pré concentração em - 0,5 V, verifica-se um pico de corrente anódica em ± 0,01 V vs Ag/AgCl ,KCl(sat). Utilizando eletrodo de disco de carbono vítreo como eletrodo de trabalho, na modalidade de onda quadrada, obteve-se uma dependência linear na faixa de concentração entre 1,0 x 10-9 mol L-1 a 2,2 x 10-8 mol L-1, com um coeficiente de correlação linear em 0,999 e um limite de detecção de 6,2 x 10-10 mol L-1. Tais resultados possibilitaram a determinação de 9-THC na ordem de nmol L-1. / Marijuana, the illicit drug that is most consumed worldwide, contains 9-tetrahydrocannabinol (9-THC) as the main psychoactive substance. Presumptive colorimetric tests are usually performed on seized marijuana (or any illicit drug) samples: the addition of specific reagents to the marijuana extract solution prompts a change in. This study was developed using voltammetric techniques in organic medium (N,N-dimethylformamide) using tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte, and glassy carbon and platinum disc as working electrode. Applying a pre-concentration potential of -0.5 by square-wave voltammetry, we detected a well-defined anodic peak current in ± 0.01 V versus Ag/AgCl, KCl(sat); 9-THC detection presented linear dependence at concentrations ranging from 1.0 × 10-9 mol L-1 to 2.2 × 10-8 mol L-1, with a linear correlation coefficient 0.999 and a detection limit of 6.2 × 10-10 mol L-1, using the glassy carbon disc working electrode.

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