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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.
241

Time-resolved spectroscopic studies of photo-defluorination and photo-decarboxylation reactions of selected fluoroquinolone antibiotic and nonsteroidal anti-inflammatory drugs

Su, Tao, 苏涛 January 2013 (has links)
This thesis aimed to investigate the features and properties of the ground states, transient species and photoproducts involved in the photophysical and photochemical processes for four kinds of drug compounds: lomefloxacin (LF), norfloxacin (NF), tiaprofenic acid (TPA), and flurbiprofen (Fp). The investigation used femtosecond transient absorption (fs-TA), nanosecond transient absorption (ns-TA), UV/Vis absorption spectra (UV/Vis), nanosecond transient resonance Raman (ns-TR2) and nanosecond time-resolved resonance Raman spectroscopy (ns-TR3), as well as density functional theory (DFT) calculations. Although many previous investigations have indicated that photo-defluorination or photo-decarboxylation reactions may account for the phototoxicity for these compounds, detailed information on the mechanisms remains unclear. In this thesis, the photo-defluorination reaction of LF was explored in neutral water at pH 7.2. The fs-TA results revealed that the lowest lying excited singlet state species (S1) partially decayed into the ground state through fluorescence emission and partially underwent cleavage of the carbon-fluorine bond at position 8 to generate into a singlet aryl cation. Subsequently, intersystem crossing (ISC) allowing the transformation from singlet cation to triplet carbene was observed. Finally, a cyclization reaction with the N-ethyl chain took place for the triplet carbene to generate the final product. The mechanism underlying NF phototoxicity involves a photo-defluorination reaction in neutral water (pH=7.2). The fs-TA spectra indicated that the S1 underwent efficient ISC to swiftly transform into lowest excited triplet (T1) The ns-TA gained under nitrogen-saturated condition observed a new transient species produced from T1 that was proposed to be a transient species derived from the photo-defluorination reaction involving a SN2Ar* mechanism. The photo-defluorinated product ultimately experienced an ISC process to produce the final product. The photo-decarboxylation mechanism of TPA was studied in a neutral phosphate buffered solution (PBS). The fs-TA data revealed that S1 went through an efficient ISC to rapidly transform into T1 that then undergoes a photo-decarboxylation reaction to produce a triplet biradical species (denoted as TB3). The ns-TA and ns-TR3 results supplied evidence of the protonation process of TB3 that produces the neutral species (denoted as TBP3) that then decayed through ISC to give rise to the singlet TBP species, which underwent further reaction to make the final product (DTPA). The photo-decarboxylation reaction of Fp was explored in pure acetonitrile (MeCN). The second excited singlet (S2) went through internal conversion (IC) to decay to S1. Intriguingly, three different pathways for S1 decay co-exist. One pathway is fluorescence emission and the second is an ISC process. The third pathway is the homolysis of the carbon α bond reaction that proceeds to generate two radical species, one being a carboxyl species and the other being the residual, denoted as FpR that was liable to be oxidized under an oxygen-saturated condition to yield a new radical species with the addition of one oxygen molecule which is denoted as FOR that then experienced intramolecular hydrogen transfer (IHT) and dehydroxylation (DHO) to produce the final product. / published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
242

THE NON-STEROIDAL ANTI-INFLAMMATORY DRUGS-MYOCARDIAL INFARCTION ASSOCIATION: AN INVESTIGATION OF KENTUCKY MEDICAID PRESCRIPTION CLAIMS

Gordon, Leonard A. 01 January 2015 (has links)
Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used medications globally. There are generally two types: selective (COX-2) and traditional NSAIDs (COX-1). They are primarily used for the treatment of pain. They gained attention after a study about their basic mechanisms highlighted their toxicity. Several studies have reported an association between NSAIDs and risk of myocardial infarction (MI). However, the direction of the relationship is not conclusive. Further studies are needed to ascertain the direction of this relationship and evaluate the present situation with available drugs. Due to the seriousness of cardiovascular diseases as one of the leading cause of death, continuous monitoring of the NSAIDs-MI association is needed. The purpose of this dissertation was to investigate the association between NSAIDs and MI in a younger (30-64 years) Kentucky Medicaid population with a 12 year window of data. The three specific aims were: (1) to understand the characteristics of the Kentucky Medicaid population with respect to NSAID use: (2) to evaluate the NSAID-MI relationship with a 12 year follow-up in a young heavily-burdened population for cardiovascular diseases: and (3) to investigate the MI risk of meloxicam, celecoxib and naproxen compared to no exposure. A retrospective study was conducted employing data from January 1st 2000 and December 31st 2012. The data comprised demographic, prescription and medical files. Within this cohort, a nested case control study was conducted. Cases of MI were matched to four controls on race and gender. The results suggested that exposure to COX 2 presented an increased adjusted risk for MI (1.138(0.983, 1.318)). However, this risk was significantly increased for COX-2 only users compared to COX-1 only users (1.221 (1.03, 1.485)) and 30-40 year olds (1.600 (1.082, 2.367)). Meloxicam, celecoxib and naproxen compared to no exposure showed meloxicam presented a non-significant different risk for MI (1.26 (0.98, 1.63)) and celecoxib presented a significantly increased risk for MI (1.52 (1.26, 1.82)). This study considered pattern of use in determining continuous usage by looking at both continuous and sporadic users of NSAIDs and also considered patient switching patterns between classes of NSAIDs.
243

The relationship between Cox-2 inhibitors and cardiovascular risk: a retrospective analysis using the Veteran Affairs (VA) database

Motsko, Stephen Paul 28 August 2008 (has links)
Not available / text
244

Regulation of Cyclooxygenase-2 expression in human macrophages

Barrios-Rodiles, Miriam. January 2000 (has links)
High output of prostaglandins (PGs) are the hallmark of inflammatory and immune reactions. A rate-limiting step in the production of PGs is the presence of the enzyme cyclooxygenase (COX). COX exists as two isoforms: COX-1 which is constitutively expressed in most cells and COX-2 which is inducible by LPS, proinflammatory cytokines and other stimuli in cells involved in inflammation. The objective of this study was to determine the effect of nonsteroidal antiinflammatory drugs and proinflammatory cytokines on COX-2 expression in human macrophages. COX-2 specific (NS-398) and non-specific (aspirin, indomethacin and naproxen) inhibitors showed no effect on COX mRNA and protein expression induced by LPS. In contrast, the drugs markedly inhibited COX activity as measured by the accumulation of PGE2. The induction of COX-2 mRNA expression by LPS was rapid and sustained. However, LPS only transiently stimulated the transcription of COX-2 gene and activation of the transcription factor NF-kappaB. LPS stimulated the release of IL-1beta and TNF-alpha but these cytokines had no autocrine effect on the transcriptional or post-transcriptional regulation of COX-2. The presence of LPS was essential for the maintenance of high levels of long-lived COX-2 mRNA. As IFN-gamma is a major macrophage activating factor, we determined the role of this cytokine on COX-2 expression induced by exogenous IL-1beta. IFN-gamma-primed macrophages showed significantly lower levels of COX-2 mRNA, protein and PGE2 production compared to non-primed cells. IFN-gamma specifically decreased the transcriptional activation of COX-2 gene by IL-1beta but not by LPS without affecting the rate of mRNA decay. These results demonstrate that sustained production of PGE2 by macrophages in an inflammatory milieu can occur through the stabilization of COX-2 mRNA and revealed a role for IFN-gamma as an anti-inflammatory cytokine counteracting the expression of COX-2. A better understanding of COX-2 regulation will
245

Mesenchymal stromal cells of human umbilical cord Wharton's jelly accelerate wound healing by paracrine mechanisms

Ueda, Minoru, Kikkawa, Fumitaka, Hibi, Hideharu, Iwase, Akira, Takikawa, Sachiko, Yamamoto, Akihito, Shohara, Ryutaro 09 1900 (has links)
名古屋大学博士学位論文 学位の種類 : 博士(医学)(課程) 学位授与年月日:平成25年1月31日 匠原龍太郎氏の博士論文として提出された
246

Non steroidal anti-inflammatory drugs and cardiovascular risk: identifying evidence for channelling bias in a population based study

2015 July 1900 (has links)
ABSTRACT The non-steroidal anti-inflammatory drug (NSAID), diclofenac, has been associated with a high risk for cardiovascular events in observational studies. However, majority of studies identifying this association were conducted when diclofenac was the only NSAID that could be obtained as a combination product (i.e., formulated with misoprostol). As a result, channelling bias might have resulted if prescribers selected the combination of diclofenac/misoprostol (Diclo-Miso) in patients with poor health status frequently than other NSAID products. The main purpose of this study was to identify evidence for channelling bias in a cohort of patients with coronary heart disease (CHD) prescribed NSAIDs. Three independent, retrospective analyses were carried out using Saskatchewan’s health administrative databases. Patients were eligible if they were hospitalized with CHD event between January 1, 1994 and December 31, 2008. In the first analysis, a time series was conducted to examine trends in the use of NSAIDs following discharge from original hospitalization. In the second analysis, multivariate logistic regression models were constructed to identify characteristics of patients prescribed with Diclo-Miso in comparison to single-entity diclofenac. Finally, a nested case-control study was conducted to examine the risk for recurrent myocardial infarction (MI)/ Unstable Angina (UA) or death among patients prescribed with Diclo-Miso versus single-entity diclofenac. For each case, up to five controls were matched by age and sex. Between 1994 and 2008, NSAIDs were used by 20.1% (3,099/15,393) of patients in the year following discharge from their original MI/UA hospitalization. Use of these agents was relatively stable until 2004 when the COX-2 selective agent rofecoxib was withdrawn from the market. Following this date (i.e., September 30, 2004), the use of Diclo-Miso and single-entity diclofenac appeared to follow different trends. However, available patient and disease specific factors could not explain diverging utilization trends. Further, no differences were observed in the risk of experiencing recurrent MI/UA between patients receiving Diclo-Miso (OR 0.88, 95% CI 0.72-1.08, p=0.22) or single-entity diclofenac (OR 0.78, 95% CI 0.60-1.00, p=0.06) versus patients not exposed to NSAIDs. Based on the study’s result, channelling bias does not appear to be a major threat to the analysis of cardiovascular toxicity of diclofenac products.
247

Potential Roles for the Neurotrophic Molecules Agrin and Neuregulin in Regulating Aspects of the Inflammatory Response

Mencel, Malwina 22 May 2015 (has links)
Agrin and neuregulin are neurotrophic molecules well known for their roles at synapses in the peripheral and central nervous systems. The expression of these two molecules is not restricted to these sites however, as they are broadly expressed across multiple organ systems. What roles do agrin and neuregulin play within these alternate systems; what is the function of these molecules outside the nervous system? Here I investigate potential roles for agrin and neuregulin in inflammation. Inflammation is an immediate response by innate immune cells, primarily macrophages, to infection and is characterized by the synthesis of pro-inflammatory mediators. The innate immune system possesses multiple redundant mechanisms to locally control inflammation. The neuro-immune axis is one means of control. Often called the cholinergic anti-inflammatory pathway, it acts to regulate local inflammation via nerve-secreted acetylcholine signaling through the homopentameric α7 nicotinic acetylcholine receptors (α7nAChR) present on macrophages. Both agrin and neuregulin have been independently described to share an intricate relationship with acetylcholine receptors (AChR) in the nervous system. Agrin is best known for its role in AChR aggregation at the neuromuscular junction while neuregulin has related roles in AChR transcription, cell survival, communication and differentiation. Based on the common characteristics of synapses in the nervous and immune systems we were curious to see if agrin and neuregulin played analogous roles on macrophages. Here we show that agrin and its receptor dystroglycan are expressed on RAW264.7 macrophages. In addition, agrin treated macrophages demonstrate increased endogenous agrin and α7nAChR expression. By blocking α-dystroglycan (α-DG), a receptor for agrin, with an anti-α-DG antibody we further saw a reduction in agrin expression. We also show that agrin is able to aggregate surface α7nAChRs and transmembrane agrin co-localizes with α7nAChRs therein. Agrin appears to induce approximately a 15-fold increase in anti-inflammatory cytokine IL-10 in macrophages but does not increase pro-inflammatory cytokine TNF-α or IL-6 synthesis. Agrin-treated macrophages challenged with LPS, a potent activator of inflammation, exhibit a 57% decrease in IL-6. Macrophages treated with agrin also exhibit a 4-fold increase in STAT3, a regulator of anti-inflammatory action. The potential anti-inflammatory effects of agrin in the periphery parallel previous work describing the effects of neuregulin in the brain. Previous work completed by our lab suggests a role for neuregulin in augmenting the expression of α7nAChRs on microglia, the macrophages of the brain, but not in peripheral macrophages. Here we show that treatment of LPS challenged microglia with neuregulin produces an 88% decrease in IL-6 and a 33% decrease in TNF-α. These results indicate both agrin and neuregulin are able to induce an increase in α7nAChRs and augment the synthesis of pro- and anti-inflammatory cytokines in their respective systems. These results also further the support the evidence of neuro-immune crosstalk in the immune system. Taken together these results present two novel players in inflammatory regulation by macrophages in the periphery and CNS.
248

Overview of the prescribing patterns of non-steroidal anti-inflammatory drugs : 2004-2006 / Magdalena Adriana Harmzen

Harmzen, Magdalena Adriana January 2008 (has links)
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for systemic control of acute and chronic pain and inflammation (Lin et ah, 2000:1129), but usage problems and side-effects that occur during the post-marketing phase of these drugs are well documented (Thiefin & Beaugerie, 2005:287). Following the demonstration of the value of anti-inflammatory therapy in diseases like rheumatoid arthritis (Boardman & Dudley Hart, 1967:268), new NSAIDs appeared on the market (Dieppe et al., 2004:867), and the indications steadily broadened from inflammatory diseases to almost any painful condition. Studies have indicated that NSAID-associated serious upper gastro-intestinal (GI) adverse events result in 103 000 hospitalisations (Bombardier, 2002:4) and 165 000 deaths per year in the United States. A study in South Africa in 2002 indicated that NSAID utilisation contributed considerably to the total cost of all medicine items from a medicine claim database in the private health care sector (Joubert, 2002:260). The objective of this study was to determine the prevalence and cost of non-steroid anti-inflammatory drugs in a section of the private health care sector, and specifically to determine the prevalence, usage and cost of Coxib (Specific cyclo-oxygenase-2 inhibitor) medicine items before and after the withdrawal of Vioxx® from the market in September 2004 (Merck, 2004). Data from two medicine claim databases for the years 2004, 2005 and 2006 (medicine claim database I) and the years 2005 and 2006 (medicine claim database M), were analysed by means of a retrospective drug utilisation review (DUR) study. The usage of Coxib medicine items was determined, and compared for the periods before and after the withdrawal of Vioxx® in September 2004. It was found that between 9 and 10.5 per cent of prescriptions dispensed through both medicine claim database I and medicine claim database M during the study period were NSAID prescriptions. NSAID medicine items on medicine claim database I represented between 3.9 % (R25 942 986) and 2.9 % (R8 073 034) of the total cost of all medicine items claimed from 2004 to 2006. NSAIDs represented 3.1 % (R58 290 412) and 2.8 % (R57 752 267) of the cost of all medicine items claimed through medicine claim database M during 2005 and 2006 respectively, indicating similar trends in the two medicine claim databases. The prevalence of Coxibs on medicine claim database I decreased from almost 20 % (47 938) in 2004 to 8.4 % (13 276) in 2005, but showed an increase again to 10.9 % (12 355) in 2006. The prevalence of both cyclo-oxygenase (COX) inhibitors, and Coxibs demonstrated a change during 1 September 2004 to 31 December 2004 when COX-inhibitors showed an increase in use, while Coxibs showed and almost equal but opposite trend with a decrease in use. This could possibly be related to perceptions of providers and public with regard to Coxibs and their related safety after the withdrawal of Vioxx® on 30 September 2004 (Merck, 2004) and other Coxibs such as Bextra® (FDA, 2005) in 2005 in USA. It is concluded that most patients who were using Coxibs before the withdrawal of Vioxx®, substituted Coxibs for COX-inhibitors, that are known for their possible gastro-intestinal side-effects. Recommendations for future research regarding NSAID use were also made, and included an investigation of the usage of Coxibs in different age groups, as well as the combination of NSAIDs with gastro-protective medicines in long-term use. / Thesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2009.
249

PKA Signaling in ABCA1 Function: A Role in Modulation of Cholesterol Efflux and Macrophage Inflammation

Ma, Loretta T. K. 28 October 2013 (has links)
Formation of lipid-laden macrophage foam cells and inflammation are the central components in the initiation and progression of atherosclerosis. ABCA1 is well established as an anti-atherogenic factor that facilitates cellular cholesterol and phospholipid efflux, promotes reverse cholesterol transport, and suppresses pro-inflammatory cytokine secretion. Through these functions, ABCA1 is capable of reducing the lipid burden in atherosclerotic plaque. PKA signaling is an integral factor in promoting many anti-atherogenic functions of ABCA1; however, mechanistic aspects of PKA signaling associated with ABCA1 remain poorly defined. Thus, the first part of this study investigates the involvement of spatially regulated PKA signaling in ABCA1 activities through the use of st-Ht31, a PKA de-anchoring peptide. It appears that de-anchoring PKA robustly increases ABCA1-mediated microparticle release, one of the cholesterol efflux pathways of ABCA1, and reverses macrophage foam cell formation. These results highlight the significance of subcellular compartmentalization of PKA signaling in ABCA1 functions and present PKA de-anchoring as a potential therapeutic strategy for atherosclerotic lesion regression. The second part of this study provides evidence that ABCA1 activates PKA and promotes the secretion of anti-inflammatory IL-10, a cytokine crucial for inflammation resolution. Furthermore, we provide evidence that this elevated PKA activity is the underlying mechanism in which macrophage ABCA1 promotes M2-like inflammatory response. Our results also suggest that ABCA1 activates PKA by regulating cholesterol, which poises macrophages towards an anti-inflammatory or M2-activated phenotype. Collectively, we demonstrate that PKA signaling plays a crucial multifactorial role in anti-atherogenic functions of ABCA1.
250

Overview of the prescribing patterns of non-steroidal anti-inflammatory drugs : 2004-2006 / Magdalena Adriana Harmzen

Harmzen, Magdalena Adriana January 2008 (has links)
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for systemic control of acute and chronic pain and inflammation (Lin et ah, 2000:1129), but usage problems and side-effects that occur during the post-marketing phase of these drugs are well documented (Thiefin & Beaugerie, 2005:287). Following the demonstration of the value of anti-inflammatory therapy in diseases like rheumatoid arthritis (Boardman & Dudley Hart, 1967:268), new NSAIDs appeared on the market (Dieppe et al., 2004:867), and the indications steadily broadened from inflammatory diseases to almost any painful condition. Studies have indicated that NSAID-associated serious upper gastro-intestinal (GI) adverse events result in 103 000 hospitalisations (Bombardier, 2002:4) and 165 000 deaths per year in the United States. A study in South Africa in 2002 indicated that NSAID utilisation contributed considerably to the total cost of all medicine items from a medicine claim database in the private health care sector (Joubert, 2002:260). The objective of this study was to determine the prevalence and cost of non-steroid anti-inflammatory drugs in a section of the private health care sector, and specifically to determine the prevalence, usage and cost of Coxib (Specific cyclo-oxygenase-2 inhibitor) medicine items before and after the withdrawal of Vioxx® from the market in September 2004 (Merck, 2004). Data from two medicine claim databases for the years 2004, 2005 and 2006 (medicine claim database I) and the years 2005 and 2006 (medicine claim database M), were analysed by means of a retrospective drug utilisation review (DUR) study. The usage of Coxib medicine items was determined, and compared for the periods before and after the withdrawal of Vioxx® in September 2004. It was found that between 9 and 10.5 per cent of prescriptions dispensed through both medicine claim database I and medicine claim database M during the study period were NSAID prescriptions. NSAID medicine items on medicine claim database I represented between 3.9 % (R25 942 986) and 2.9 % (R8 073 034) of the total cost of all medicine items claimed from 2004 to 2006. NSAIDs represented 3.1 % (R58 290 412) and 2.8 % (R57 752 267) of the cost of all medicine items claimed through medicine claim database M during 2005 and 2006 respectively, indicating similar trends in the two medicine claim databases. The prevalence of Coxibs on medicine claim database I decreased from almost 20 % (47 938) in 2004 to 8.4 % (13 276) in 2005, but showed an increase again to 10.9 % (12 355) in 2006. The prevalence of both cyclo-oxygenase (COX) inhibitors, and Coxibs demonstrated a change during 1 September 2004 to 31 December 2004 when COX-inhibitors showed an increase in use, while Coxibs showed and almost equal but opposite trend with a decrease in use. This could possibly be related to perceptions of providers and public with regard to Coxibs and their related safety after the withdrawal of Vioxx® on 30 September 2004 (Merck, 2004) and other Coxibs such as Bextra® (FDA, 2005) in 2005 in USA. It is concluded that most patients who were using Coxibs before the withdrawal of Vioxx®, substituted Coxibs for COX-inhibitors, that are known for their possible gastro-intestinal side-effects. Recommendations for future research regarding NSAID use were also made, and included an investigation of the usage of Coxibs in different age groups, as well as the combination of NSAIDs with gastro-protective medicines in long-term use. / Thesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2009.

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