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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

The Effects of Chronic Alcohol Consumption on Ovarian Function/ Morphology

Roberts, Destiny 01 May 2017 (has links)
Chronic alcohol (ethanol) consumption has been known to affect the major organs of the body and particularly the liver. However, the effects of chronic ethanol consumption on the female reproductive system remain relatively unstudied. A convenient way to study these effects is by analyzing laboratory mice that have been fed an ethanol diet for an extended period of time and comparing them to control mice. In this study, female mice were separated into control and ethanol fed groups. The mice were placed on their specified diets and observed over the course of six weeks. The mice were fed and weighed daily throughout the duration of the experiment. Once a week, vaginal washes were performed on both groups of mice to determine the stage of the estrous cycle for each mouse. At the end of the six weeks, the mice were sacrificed and the ovaries were harvested and fixed in 4% paraformaldehyde. The ovaries were then paraffin embedded and sectioned. Glass microscope slides were then stained using Hematoxylin and Eosin staining procedures for evaluation using standard light microscopy. The tissue’s morphology, follicle development, presence of corpora lutea, and overall appearance were analyzed. Due to the premature deaths of several mice in first group of ethanol fed mice, the experiment was repeated with three more groups of mice to obtain a better representation of data. The data from the control group was compared to that of the ethanol fed group. The mice that received the ethanol fed diet ceased to cycle and arrested in the diestrous phase of the estrous cycle. Our data indicates that the ovarian follicles within the ethanol fed mice show signs of degeneration in the 4b, 5a, 5b, 6, and 7 levels of development. There are also no notable corpora lutea present within the ovaries of the ethanol fed mice. Our findings indicate that chronic alcohol consumption has deleterious effects on ovarian morphology in mice.
2

A systematic column performance comparison for the confirmation of opioids used in pain management by LC-MS

Stallard, Derek 01 May 2014 (has links)
In this study, three different chromatographic column chemistries (C18, Pentafluorophenyl (PFP), Hydrophilic Interaction Chromatography (HILIC)) were compared under optimal conditions to determine which stationary performed best in the separation and detection of a mixture of opioids using LC-MS. Furthermore, these stationary phases were examined in three different column technologies – traditional silica, porous shell, and porous polymer (PRP). The PRP column had the best peak shape for all 13 opioids and dominated for later-eluting compounds. In terms of column reproducibility, the Hamilton C18 column had the lowest %RSD values. The Kinetex HILIC produced the most theoretical plates and best resolution for polar compounds as did the Hamilton C18 for nonpolar compounds. Finally, Kinetex PFP and Hamilton PRP both demonstrated themselves as viable alternatives to the C18 column chemistry for analysis of this drug class.
3

Hyperthermia as a Cancer Treatment- From Theory to Practice

Fullerton, Graham 01 January 2018 (has links)
Using iron super-paramagnetic and ferromagnetic nanoparticles composed of Fe3O4 molecules, scientists analyze the effectiveness and practicality of this new treatment theory, hyperthermia. The problems of magnetic particle density, isothermal barriers/cellular cooling thresholds, and nanoparticle specific targeting are addressed in this review. Iron magnetic nanoparticles were chosen due to their relatively low biological reactivates and lack of subsequent cellular toxicity. However, there are significant heating problems associated with these magnetic nanoparticles due to their relative size and short thermal time constants or thermal half-lives. Effectively, these aforementioned issues create a phenomenon where cancerous cells, surrounded by unheated healthy tissue, exhibit properties similar to those of an isothermal barrier. As a result, target cells experience limited gross heating, which is localized to the area directly surrounding the active magnetic nanoparticle within the cytoplasm. The effects of isothermal barriers and HSP up regulation on particle-based hypothermia are profound and prevent therapeutic temperatures from being achieved in single cell heating limiting the applications for Fe3O4 magnetic nanoparticle hyperthermia applications. It has been shown that reaching a certain magnetic nanoparticle density within the cell can result in a larger heating capacity, though this effect is also dependent on the particle dispersion pattern within cytoplasm. It has yet to be concluded whether ferromagnetic particles or super-paramagnetic particles are superior or more practical for hyperthermic treatments as they each have distinct benefits, and further study is needed. Finally, the popular targeting mechanism associated with magnetic nanoparticle research, monoclonal antibodies, require that they have an organic coating (such as starch) as a means of both providing an organic binding point and as camouflage for avoiding host filtration pathways. Forgoing this organic coating could lead to increased particle density within the cell and the adoption of a more specific targeting mechanism such as virus like particles (VLPs) altered to target HSP’s could lead to an increase in yield. Furthermore the up regulation of HSPs in response to therapeutic temperature is problematic for the therapies practically.
4

Exploration of Bioactive Compounds of Ginger as a Folk Remedy for Migraines

Aleger, Nathan Vorbes 01 January 2017 (has links)
Ginger (Zingiber Officinale) has been used in Asia for centuries to treat various ailments. Ginger has been reported to alleviate migraine pain via four bioactive compounds that can reduce nitric oxide synthase (NOS) resulting in the inhibition of nitric oxide (NO). The inhibition of nitric oxide results in the vasoconstriction of the intracranial blood vessels alleviating migraine pain. It is hypothesized that ginger has structural similarities to vasoconstrictor drugs causing similar receptor interactions. A review of the bioactive compounds in ginger and popular vasoconstrictor drugs was done to determine structural similarities. The results of this study show that the compounds in ginger share no structural similarities with vasoconstrictor drugs used in the treatment of migraine headaches.
5

Cannabinoid Receptor 2 and C-X-C Chemokine Receptor 4 Interact to Abrogate CXCL12-Mediated Cellular Response

Coke, Christopher James 22 May 2017 (has links)
The expression of C-X-C Chemokine Receptor 4 (CXCR4) has been correlated with increased metastatic potential of cancer cells. CXCR4 increases tumor malignancy by encouraging tumors cells to migrate to distal organs expressing its cognate ligand, CXCL12, facilitating metastasis. Thus, targeting the CXCR4/CXCL12 signaling axis provides a good strategy to inhibit the metastatic spread of tumor cells and slow cancer progression. Various studies suggest that cannabis may have anti-proliferative as well as anti-metastatic properties, though a biochemical mechanism describing how this occurs has yet to be discovered. Our lab has confirmed that agonist-bound CXCR4 and agonist-bound Cannabinoid Receptor 2 (CB2) can form heterodimers that play a role in decreasing cancer cell migration. Simultaneous treatment of the breast cancer cell line, MDA-MB-231 and the prostate cancer cell line PC-3, with CXCL12 and AM1241, a synthetic ligand for CB2, desensitizes the intrinsic cellular response to migrate toward areas of high CXCL12 concentration. Furthermore, through co-immunoprecipitation and proximity ligation assays (PLA), we have determined that there is increased interaction between the two receptors with co-stimulation of respective agonists, providing evidence for the therapeutic notion that treating tumors that endogenously secrete CXCL12 with exogenous ligands for the cannabinoid can induce dimerization. Moreover, when CXCR4 and CB2 were activated simultaneously with various agonists, decreases in migration were observed, confirming that the regulatory activity was receptor-based, not agonist-based. Finally, to determine whether simultaneously–treated, dimerized receptors inhibited activity of respective receptors, calcium mobilization assays to determine G-protein coupled receptor activation were employed. Results showed that transiently activated calcium levels were significantly lower in response to simultaneous treated cells when compared to cells treated with their individual ligands. Phosphorylation of ERK and AKT were abrogated in response to simultaneous stimulation indicating loss in downstream signaling. Therefore, we believe that the interaction of CB2 with CXCR4 may play a role in inhibiting the cells response to CXCL12, leading to a loss in metastatic potential of cells expressing these receptors.
6

Chronic Behavioral and Cognitive Deficits in a Rat Survival Model of Organophosphate Toxicity

Huang, Beverly 01 January 2015 (has links)
Organophosphates (OPs) are a major class of pesticides and nerve agents that elicit acute toxicity by inhibiting acetylcholinesterase (AChE), the enzyme responsible for the degradation of the neurotransmitter acetylcholine in the central and peripheral nervous systems. Acetylcholine accumulation following extensive AChE inhibition leads to an acute cholinergic syndrome characterized by autonomic dysfunction, involuntary movements, muscle fasciculations, respiratory distress, and seizures. Despite their classification as moderate to highly toxic, OP pesticides are the most widely used class of insecticides in the U.S., and are even more commonly used worldwide. Additionally, there is a growing concern that OP nerve agents could be used to cause mass civilian casualties. It is well known that the survivors of acute nerve gas poisoning and chronic OP pesticide exposure exhibit neurobehavioral deficits including mood changes, depression, and memory impairments. Despite this, there are very few treatments available for OP-intoxication survivors and this topic is under-researched. In this study we investigated whether animals surviving a single severe OP exposure exhibited long-term neurological impairments, using two OP agents: paraoxon (POX) and diisopropyl fluorophosphates (DFP), as well as a non-OP chemoconvulsant, pilocarpine (Pilo), which acts as a muscarinic agonist. Exposure to POX, DFP, or Pilo led to overt signs of cholinergic toxicity. POX and DFP rats were rescued with an optimized atropine, 2-PAM, and diazepam therapy per current OP-exposure treatment guidelines, while Pilo rats were given only diazepam. Saline was administered to control rats at all pharmacological timepoints. Surviving rats were studied using established behavioral assays for identifying symptoms of depression and memory impairment 3-6 months after exposure to toxic agents. In the forced swim test, POX, DFP, and Pilo animals exhibited increased immobility time indicative of a despair-like state. In the sucrose preference test, POX, DFP, and Pilo rats did not display a preference for sucrose water, indicating an anhedonia-like condition. POX, DFP, and Pilo rats also displayed increased anxiety as characterized by significantly lower performance in the open arm of the elevated plus maze. Furthermore, when tested with a novel object recognition paradigm, POX, DFP, and Pilo rats exhibited a significantly lower discrimination ratio, indicating impaired recognition memory. The results indicate that these models of survival from severe POX and DFP exposure can be employed to study chronic behavioral and cognitive comorbidities and to further investigate the molecular bases for these comorbidities, potentially leading to the development of pharmacological therapies.
7

Dual PI3K/mTOR Inhibition with BEZ235 Augments the Therapeutic Efficacy of Doxorubicin in Cancer without Influencing Cardiac Function

Durrant, David E. 01 January 2015 (has links)
Cancer continues to be a leading cause death in the United States despite improved treatments. Cancerous lesions form after acquiring oncogenic driver mutations or losing tumor suppressor function in normal cells. Traditional therapies have included use of genotoxic substances that take advantage of the increased growth rate and loss of tumor suppressor function to cause cell death. One such drug is the anthracycline antibiotic doxorubicin (DOX). DOX interchelates into DNA and disrupts transcriptional machinery while also poisoning topoisomerase II. This results in single and double stranded DNA breaks, which if severe enough leads to either necrotic or apoptotic cell death. DOX has been very effective at treating several different cancers and is still widely used today however its clinical use is limited due to cumulative dose dependent cardiotoxicity. Therefore, combination therapy targeting survival pathways is utilized to minimize the cumulative dose of DOX without ameliorating its anti-tumor effects. We investigated the potential anti-cancer effects of combining the dual PI3K/mTOR inhibitor, BEZ235 (BEZ), with DOX in pancreatic, breast and other cancer cells lines as well as its associated effects on the heart. Our results showed that co-treatment of BEZ with DOX increased apoptosis in a manner that was dependent on inhibition of the AKT survival pathway. Moreover, BEZ co-treatment with DOX had additive effects towards cell viability while it significantly enhanced necrotic cell death compared to either drug alone. Furthermore, we observed that physiological concentrations of BEZ inhibited ABCB1 efflux resulting in increased intracellular accumulation of DOX, which led to increased DNA damage. In addition, BEZ in combination with gemcitabine (Gem) reduced cell proliferation but did not enhance necrosis or apoptosis. Treatment with BEZ and DOX in mice bearing tumor xenographs reduced tumor growth as compared to BEZ, DOX or Gem. Moreover, BEZ reduced DOX toxicity in rat myoblast cells and did not potentiate the effects of DOX in tumor-bearing mice. We propose that combining BEZ with DOX could be a novel therapeutic approach for the treatment of patients with cancer in the hope of improving the prognosis of this deadly disease.
8

The Use of High-Throughput Virtual Screening Software in the Proposal of A Novel Treatment for Congenital Heart Defects

Suh, Caitlin D 01 January 2019 (has links)
Conventional screening of potential drug candidates through wet lab affinity experiments using libraries of thousands of modified molecules is time and resource consuming, along with the fact that it contributes to the widening time gap between the discovery of disease-causing mutations and the implementation of resulting novel treatments. It is necessary to explore whether the preliminary use of high-throughput virtual screening (HTVS) software such as PyRx will curb both the time and money spent in discovering novel treatments for diseases such as congenital heart defects (CHDs). For example, AXIN2, a protein involved in a negative feedback loop inhibiting the Wnt/β-catenin signaling pathway important for cardiogenesis, has recently been associated with CHD. The loss-of-function mutation L10F on the tankyrase-binding domain of AXIN2 has been shown to upregulate the pathway by loss of inhibition ability, leading to the accumulation of intracellular β-catenin. In a different paper, however, AXIN2 has been shown to be stabilized using XAV-939, a small-molecule drug which targets tankyrase. PyRx and VMD will be used to modify the drug in order to increase its binding affinity to AXIN2, stabilizing the protein and reinstating its inhibitory property to treat CHDs. When used in adjunction to wet lab experiments, HTVS software may decrease costs and the time required to bring a potentially life-saving treatment into use.
9

Glycosaminoglycan Mimetics for the Treatment of Cancer and Lung Inflammation

Morla, Shravan 01 January 2019 (has links)
Glycosaminoglycans (GAGs) are linear polysaccharides whose disaccharide building blocks consist of an amino sugar and either uronic acid or galactose. They are expressed on virtually all mammalian cells, usually covalently attached to proteins, forming proteoglycans. GAGs are highly negatively charged due to an abundance of sulfate and carboxylic acid groups, and are structurally very diverse, with differences arising from chain length, the type of monomeric units, the linkages between each monomeric unit, the position of sulfate groups, and the degree of sulfation. GAGs are known to interact with a multitude of proteins, impacting diverse physiological and pathological processes. In addition, most of the biological interactions mediated by proteoglycans are believed to be primarily because of the GAG chains present on their surface. Considering the involvement of GAGs in multiple diseases, their use in the development of drugs has been of significant interest in the pharmaceutical field. Heparin, the first GAG-based drug developed in 1935, is still the most widely used anticoagulant in the world. The therapeutic potential of GAGs for the treatment of many other disease states, including cancer, inflammation, infection, wound healing, lung diseases, and Alzheimer’s disease, is being actively studied with many GAGs currently in clinical trials. However, challenges associated with the heterogeneous and complex structure of GAGs, limit their successful development. To combat such issues, our lab has focused on developing Non- Saccharide GAG Mimetics (NSGMs) as structural mimics of GAGs. NSGMs, being synthetic molecules, offer multiple advantages over GAGs. The studies mentioned here describe our efforts in the development of NSGMs as potential therapeutics for cancer, and cystic fibrosis.
10

From Disco to Electronic Music: Following the Evolution of Dance Culture Through Music Genres, Venues, Laws, and Drugs.

Colombo, Ambrose 01 January 2010 (has links)
Electronic dance music is a genre that has been long in the making. Starting with disco in the 1970s, dance culture genres evolved into house, acid house, techno, garage, 2-step, hardcore, gabba, san frandisco, electro, and many others. This paper studies the transformation of electronic sound, and the contributing/impeding factors involved. Drug use is heavily related to the creation and enjoyment of music, and features prominently in the history of dance culture. Starting with the use of acid in the 1960s and progressing to the use of acid, Quaaludes, poppers, speed in the 1970s, with MDA featured in clubs toward the end of the decade. The 1980s began the recreational use of MDMA, but not until the late 80s in UK acid parties did it become known as the party drug that it is known as today. MDMA use then spread rampantly throughout the US as the UK culture was exported and emulated. UK acid parties were the precursor to raves, which were illegal, and the backlash from the law was incredible and organized. Slowly licensing laws became more relaxed, and permits became easier to obtain, making future raves more legal, but according to ravers, less fun, ending at 2am instead of 8am, and forcing the drugs scene underground, rather than having them openly solicited. Organized crime in the UK got much worse as gangs realized the potential profits of selling drugs, and the scene forever changed because of this in the early 90s. The raves of the early 90s in New York, the Midwest, and San Francisco, were paradise in comparison. San Francisco enjoyed the most freedom, and beach raves became common. The electronic dance culture found a home in large festivals, and perhaps because of this the future of electronic music remains uncertain, especially with the casualties that have recently happened relating to ecstasy use, and complications in organizing such massive events.

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