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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.
11

Intraperitoneal, Continuous Carboplatin Delivery for the Treatment of Ovarian Cancer

Zhidkov, Nickholas 04 December 2012 (has links)
Ovarian cancer remains the deadliest gynecologic malignancy. Current treatment has low efficacy in the long term, leading to low 5-year survival rates of 20-40%. Treatment-free periods between cycles of chemotherapy are accepted in standard treatment. These periods lead to accelerated tumor cell proliferation, angiogenesis and drug resistance development. Studies presented herein show advantages of continuous carboplatin dosing schedule over conventional intermittent regimen, both administered intraperitoneally. Continuous carboplatin therapy blocked acceleration of cell proliferation observed during treatment-free period of intermittent therapy. Moreover, continuous carboplatin led to 57% inhibition of SKOV3 tumors grown intraperitoneally in SCID mice, a significant advantage over the 33% tumor suppression observed with intermittent carboplatin. Immunohistochemical analysis revealed continuous carboplatin led to greater tumor cell death while suppressing tumor cell proliferation and angiogenesis when compared to intermittent administration. These results show that the suppression of tumor growth with carboplatin can be enhanced by the elimination of treatment free periods.
12

Effect of NAFLD on Regulation of Hepatic Transporters and Metaboic Enzymes Using a High Fat/ High Cholesterol Dietary Model in Rats

Feng, Teresa Tong Qing 21 March 2012 (has links)
Non-alcoholic fatty liver disease is affecting an increasing population worldwide. NAFLD is closely associated with obesity and diabetes. Research has shown that the expression of some important hepatic transporters and enzymes are altered under inflammatory conditions. We examined the effect of NAFLD on the gene expression of several hepatic transporters and enzymes, as well as the impact of exercise in attenuating the effect of NAFLD. We have demonstrated that the mRNA expression of several hepatic transporters and enzymes, as well as FXR were significantly downregulated in liver of rats treated with a HFHCD. We concluded that HFHCD-induced hepatic steatosis, together with the reduced expression of FXR, contributed to the downregulation of expression of hepatic transporters and enzymes. The mRNA expression of TNF-α and IL-1β were unaffected. Interestingly, exercise was found to improve the expression levels of some transporters and enzymes.
13

Effects of Varenicline on Cue-reactivity in Individuals with Concurrent Tobacco Dependence and Heavy Alcohol Use: A Randomized, Double-blind, Placebo-controlled Trial

Wang, Shan 30 December 2010 (has links)
BACKGROUND: Alcohol and tobacco misuse and dependence are highly comorbid disorders. Varenicline alleviates symptoms of cigarette craving while preventing nicotine from binding to nicotinic acetylcholine receptors, thereby reducing nicotine’s reinforcing effects. Recent studies have shown that varenicline decreased alcohol self-administration in animal models and in one human study of heavy-drinking smokers. AIMS: To assess the effect of two-week varenicline (0.5-2mg) vs. placebo administration on cue-induced craving for tobacco and alcohol in smokers with heavy alcohol use (n = 24). METHODS: Subjects participated in two study visits where nicotine and alcohol craving and withdrawal were assessed with self-report questionnaires under four conditions (abstinence/one cigarette/neutral cues/tobacco-alcohol cues). RESULTS: Two-week administration of varenicline reduced tobacco-alcohol cue-induced cigarette cravings and reduced emotionality aspects of alcohol craving after smoking a cigarette compared to abstinence in heavy-drinking smokers. CONCLUSION: It is possible that varenicline may have particular advantages as a smoking cessation aid in heavy drinkers.
14

Evaluation of Pharmacotherapy for Common Medical Conditions in Pregnancy

Ebrahimi, Neda 07 December 2011 (has links)
Purpose Two new scales, CORECTS and PUQE-24 are introduced and validated, and the safety and effectiveness of Proctofoam-HC® in pregnancy is demonstrated. Method 315 of Motherisk NVP patients provided information on five clinical parameters as well as PUQE scores. 28 patients visiting a proctologist were graded for the severity of anal conditions by a proctologist before administering CORECTS. Pre and postnatal interviews were conducted with 204 pregnant women prescribed Proctofoam-HC®. Results Strong correlations were found between the following: PUQE-24 scores and parameters of well-being, hospitalization, and multivitamin intake; bleeding and pain components of CORECTS and the proctologist’s grade.There was no significant difference between mean birth weight of Proctofoam-HC® treated and comparison groups. There was a significant reduction in all symptoms of hemorrhoids. Conclusion PUQE-24 and CORECTS are the first validated scales used to assess the severity of NVP and hemorrhoids. Proctofoam-HC® is safe and effective for use in pregnancy.
15

Effect of NAFLD on Regulation of Hepatic Transporters and Metaboic Enzymes Using a High Fat/ High Cholesterol Dietary Model in Rats

Feng, Teresa Tong Qing 21 March 2012 (has links)
Non-alcoholic fatty liver disease is affecting an increasing population worldwide. NAFLD is closely associated with obesity and diabetes. Research has shown that the expression of some important hepatic transporters and enzymes are altered under inflammatory conditions. We examined the effect of NAFLD on the gene expression of several hepatic transporters and enzymes, as well as the impact of exercise in attenuating the effect of NAFLD. We have demonstrated that the mRNA expression of several hepatic transporters and enzymes, as well as FXR were significantly downregulated in liver of rats treated with a HFHCD. We concluded that HFHCD-induced hepatic steatosis, together with the reduced expression of FXR, contributed to the downregulation of expression of hepatic transporters and enzymes. The mRNA expression of TNF-α and IL-1β were unaffected. Interestingly, exercise was found to improve the expression levels of some transporters and enzymes.
16

Intraperitoneal, Continuous Carboplatin Delivery for the Treatment of Ovarian Cancer

Zhidkov, Nickholas 04 December 2012 (has links)
Ovarian cancer remains the deadliest gynecologic malignancy. Current treatment has low efficacy in the long term, leading to low 5-year survival rates of 20-40%. Treatment-free periods between cycles of chemotherapy are accepted in standard treatment. These periods lead to accelerated tumor cell proliferation, angiogenesis and drug resistance development. Studies presented herein show advantages of continuous carboplatin dosing schedule over conventional intermittent regimen, both administered intraperitoneally. Continuous carboplatin therapy blocked acceleration of cell proliferation observed during treatment-free period of intermittent therapy. Moreover, continuous carboplatin led to 57% inhibition of SKOV3 tumors grown intraperitoneally in SCID mice, a significant advantage over the 33% tumor suppression observed with intermittent carboplatin. Immunohistochemical analysis revealed continuous carboplatin led to greater tumor cell death while suppressing tumor cell proliferation and angiogenesis when compared to intermittent administration. These results show that the suppression of tumor growth with carboplatin can be enhanced by the elimination of treatment free periods.
17

Computational Study of Volumetric Effects of Hydration

Patel, Nisha 19 December 2011 (has links)
Molecular Dynamics (MD) simulations were used in conjunction with the Kirkwood-Buff (KB) theory to compute partial molar volume (PMV) for solutes of various chemical natures. Simulations performed with only the Lennard-Jones (LJ) potential yield PMV for solutes which coincide with the cavity volumes derived from calculations with scaled particle theory (SPT). Whereas, simulations carried out with only the repulsive LJ term produced PMV of solutes closer to their excluded volumes. We also determined the thermal volume, VT, which represents the volume of the effective void created around solutes of varying cavity sizes and applied the spherical approximation of solute geometry to evaluate the thickness of the thermal volume, . Our results reveal an increase in the thickness of thermal volume, , with an increase in the size of the solute. Our theoretical results are in good agreement with the reported empirical schemes for parsing PMV data on small solutes.
18

Computational Study of Volumetric Effects of Hydration

Patel, Nisha 19 December 2011 (has links)
Molecular Dynamics (MD) simulations were used in conjunction with the Kirkwood-Buff (KB) theory to compute partial molar volume (PMV) for solutes of various chemical natures. Simulations performed with only the Lennard-Jones (LJ) potential yield PMV for solutes which coincide with the cavity volumes derived from calculations with scaled particle theory (SPT). Whereas, simulations carried out with only the repulsive LJ term produced PMV of solutes closer to their excluded volumes. We also determined the thermal volume, VT, which represents the volume of the effective void created around solutes of varying cavity sizes and applied the spherical approximation of solute geometry to evaluate the thickness of the thermal volume, . Our results reveal an increase in the thickness of thermal volume, , with an increase in the size of the solute. Our theoretical results are in good agreement with the reported empirical schemes for parsing PMV data on small solutes.
19

Harnessing Mitochondria-penetrating Peptides for the Organellar Delivery of Small Molecule Drugs

Fonseca, Sonali 11 December 2012 (has links)
Mitochondria play essential roles in numerous cellular processes, including oxidative phosphorylation and apoptotic initiation. As a result, organellar dysfunction has been implicated in several pathologies such as cancer, diabetes and neurodegenerative diseases. The opportunity to deliver compounds to probe or treat these conditions would be highly beneficial but accessing this organelle is challenging. Prior work investigated the physicochemical properties required for mitochondrial targeting and yielded mitochondria-penetrating peptides (MPPs). MPPs possess hydrophobic and cationic character and exhibit efficient cellular uptake and mitochondrial localization. In this proof-of-principle study, MPPs were harnessed to re-route an anti-leukemia agent, chlorambucil (Cbl), from the nucleus to mitochondria. This DNA alkylating agent was selected for its rapid kinetics and facile conjugation to an MPP. In addition, because mitochondria possess their own genome, the target of this drug would also be present in the organelle. Conjugation of an MPP to Cbl (mt-Cbl) confirmed that the drug was re-routed to the mitochondria and an increase in potency was observed in several cell lines and patient samples. This gain in activity was due to the increased accessibility of the mitochondrial genome, its lack of introns and its limited repair capacity. However, despite this enhanced toxicity, a therapeutic window continued to be maintained due to the elevated mitochondrial membrane potential in cancer cells. The re-routing of Cbl also resulted in evasion of several drug resistance mechanisms. Damage directly within the organelle was sufficient to initiate apoptosis even in cell lines with disabled apoptotic triggering. In addition, mitochondrial sequestration protected mt-Cbl from drug inactivation mechanisms. Lastly, mt-Cbl inhibited Pgp efflux by unexpectedly interacting with the pumps and inhibiting activity for a short period of time. The anti-cancer activity of mt-Cbl was also assessed in vivo in xenograft models of leukemia. The conjugate was stable in mouse plasma and displayed an improved pharmacokinetic profile. In addition, mt-Cbl successfully delayed tumor growth in two xenograft models and continued to alkylate mitochondrial DNA in vivo. These studies demonstrate that MPPs can be harnessed to re-route drugs to this organelle. Mitochondrial re-targeting could be a novel method of re-purposing FDA-approved drugs to enhance activity and evade resistance.
20

Chip-based Sensors for Disease Diagnosis

Fang, Zhichao 18 January 2012 (has links)
Nucleic acid analysis is one of the most important disease diagnostic approaches in medical practice, and has been commonly used in cancer biomarker detection, bacterial speciation and many other fields in laboratory. Currently, the application of powerful research methods for genetic analysis, including the polymerase chain reaction (PCR), DNA sequencing, and gene expression profiling using fluorescence microarrays, are not widely used in hospitals and extended-care units due to high-cost, long detection times, and extensive sample preparation. Bioassays, especially chip-based electrochemical sensors, may be suitable for the next generation of rapid, sensitive, and multiplexed detection tools. Herein, we report three different microelectrode platforms with capabilities enabled by nano- and microtechnology: nanoelectrode ensembles (NEEs), nanostructured microelectrodes (NMEs), and hierarchical nanostructured microelectrodes (HNMEs), all of which are able to directly detect unpurified RNA in clinical samples without enzymatic amplification. Biomarkers that are cancer and infectious disease relevant to clinical medicine were chosen to be the targets. Markers were successfully detected with clinically-relevant sensitivity. Using peptide nucleic acids (PNAs) as probes and an electrocatalytic reporter system, NEEs were able to detect prostate cancer-related gene fusions in tumor tissue samples with 100 ng of RNA. The development of NMEs improved the sensitivity of the assay further to 10 aM of DNA target, and multiplexed detection of RNA sequences of different prostate cancer-related gene fusion types was achieved on the chip-based NMEs platform. An HNMEs chip integrated with a bacterial lysis device was able to detect as few as 25 cfu bacteria in 30 minutes and monitor the detection in real time. Bacterial detection could also be performed in neat urine samples. The development of these versatile clinical diagnostic tools could be extended to the detection of various cancers, genetic, and infectious diseases.

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