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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.
571

Evaluation of Post-Operative Venous Thromboembolism Prophylaxis in Lung Transplant Patients

Douglas, Randi M., Parker, Lauren N., Katz, Michael, Cosgrove, Richard January 2012 (has links)
Class of 2012 Abstract / Specific Aims: The purpose of this study was to evaluate the effectiveness of various post-operative prophylaxis methods in lung transplant patients by comparing the incidence of venous thromboembolism (VTE) before and after the implementation of a standardized hospital order set at the University of Arizona Medical Center (UAMC) in April 2007. Methods: Paper and electronic medical charts were retrospectively reviewed if patients had a lung transplant date between October 31, 2003 – October 31, 2010. A computerized database was used to collect demographic data, length of stay (LOS), comorbid conditions, prophylaxis type (including dose/frequency), and date/type of thromboembolic events in the post-operative period prior to discharge and up to 1-year post-discharge. Main Results: Ninety-two patient charts were included in the study with 35 charts in the pre-order set (“Before”) group and 57 charts in the post-order set (“After”) group. All baseline characteristics were similar between groups except age (mean age difference 8.1 yrs, p=0.003), use of mycophenolate (Before n=24, After n=54; p=0.002), and use of medications that increase risk of VTE (Before n=6, After n=2; p=0.05). The April 2007 protocol significantly increased the number of patients receiving any method of prophylaxis (p<0.0001). However, receiving prophlyaxis did not significantly reduce event rates or readmissions due to VTE. Conclusions: Although implementation of the April 2007 protocol did not significantly reduce VTE event rates and readmissions, VTE prophylaxis should continue to remain a priority. Adherence to the implemented protocol may reduce the number of patients left without effective methods of prophylaxis.
572

The effect of nicotine and prostaglandin A2 on the lung cancer cell line NCI-H157

Willemse, Chontrelle January 2009 (has links)
Philosophiae Doctor - PhD / Lung cancer is the most common fatal cancer in terms of both incidence and mortality in the world. The most important cause of lung cancer is exposure to tobacco smoke through active or passive smoking. Nicotine which is a major component of tobacco could be assumed to be a tumour promoter since it had been indicated to stimulate tumour growth. Over expression of Bcl-2 in human lung cancer cells blocked the induction pathways (type I and II) of apoptosis. The increase in Bcl-2 in patients with lung cancer had also been linked to nicotine. In recent years nicotine replacement therapy has become a therapeutic method to treat smoker’s withdrawal symptoms and to advise cancer patients to stop smoking because, numerous cancer patients continue to smoke after their diagnosis. Non small cell lung carcinomas constitutes for approximately 80% of lung cancer cases. However, even with the development and improvement in conventional treatments of surgery, radiation and chemotherapy, the 5 year survival rate for these patients remains less than 15%. Chemoprevention, an approach to control cancer, is the use of specific natural or synthetic substances with the objective of delaying, reversing, suppressing or preventing carcinogenic progression to invasive cancer. A promising tool for chemoprevention against lung cancer could be prostaglandin A2 (PGA2), since it had been shown to have inhibitory effects on various cancer cell growth. The search for more effective agents, or combination therapies that could induce apoptosis in lung cancer are currently under investigation as a therapeutic target for the treatment of lung cancer. In order to elucidate the effect of nicotine and PGA2 on lung cancer cell proliferation in this study, an over view of the following was given;the cell cycle, tubulin, nucleoli, apoptosis, lung cancer, the etiology of cancer with reference to tobacco smoke and nicotine, the nutritional influence on carcinogenesis with reference to essential fatty acids and prostaglandins and chemoprevention.The supplements nicotine and PGA2 were administered to the NCI-H157 lung cancer cell line at the concentrations of 1 mM, 1 μM and 1 nM for nicotine and 5, 10 and 20 μg/ml PGA2. The effect of combinations of nicotine and PGA2 on the proliferation and survival was also tested. 5 μg/ml PGA2 was added to 1 mM, 1 μM and 1 nM nicotine respectively. This was also done for 10 and 20 μg/ml PGA2.These concentrations were administered to the cell culture and exposed for three different time exposures, namely 24, 48 and 72 hours. The objectives were: 1) To determine the effect of nicotine and PGA2 and combinations thereof on the growth(proliferation) of the NCI-H157 cells, where early results indicative of apoptosis lead to the investigation of the influence of nicotine and PGA2 on apoptosis. The effect of nicotine and PGA2 and their combinations on the morphology of interphase and dividing cells, as well as on the morphology of the dying cells were compared and quantified. 2) To study the effects of nicotine and PGA2 and their combinations on the nucleolar organizer region using silver stain. 3) To study the effects of nicotine and PGA2 or combinations thereof on the cytoskeleton (α-tubulin) of the cancer cells with aid of indirect immunofluorescence and to identify apoptotic cells using Hoechst 33342. 4) To determine the effect of nicotine and PGA2 and their combinations on cell cycle progression and apoptosis induction in the transformed cells using flow cytometry (DNA propidium iodide stain, Annexin V and caspase-3).In order to verify the effects of nicotine and PGA2 and their combinations on protein synthesis, SDS-PAGE and immunoblotting was employed.This study indicated the anti-apoptotic effects of nicotine. It maintained and stimulated cell proliferation of the NCI-H157 cell line. PGA2 demonstrated that it has a pro-apoptotic effect. The concentrations of 10 and 20 μg/ml PGA2 decreased cell proliferation and demonstrated its pro-apoptotic effects more effectively than 5 μg/ml PGA2. The combination of 10 and 20 μg/ml PGA2 and nicotine (1 mM, 1 μM and 1 nM) also showed a more pronounced induction of apoptosis than 5 μg/ml PGA2 and nicotine (1 mM, 1 μM and 1 nM). PGA2 therefore demonstrated that it blocked the mitogenic and anti-apoptotic effects of nicotine. With its pro-apoptotic effects, PGA2 could therefore be assumed to be a chemopreventive agent. However,it was evident that apoptotic induction was stimulated via both a dependent and an independent caspase-3 pathway and therefore further investigation is needed to indicate which pathway was activated. This study identified PGA2 as a chemopreventive agent for in vitro conditions; however, further studies are also needed to investigate the effect of in vivo conditions.
573

Systemic transplantation of bone marrow stromal cells:an experimental animal study of biodistribution and tissue targeting

Mäkelä, T. (Tuomas) 09 December 2014 (has links)
Abstract Bone marrow mesenchymal stromal cells (MSCs) and mononuclear cells (BM-MNCs) have shown great therapeutic potential in various clinical settings. Although intravascular transplantation of the cells constitutes the optimal delivery route, massive pulmonary entrapment, with the threat of embolization, remains a major obstacle for using this type of therapy. Because pulmonary entrapment is at least partially mediated by adhesion molecules, cell surface modification could enhance pulmonary passage. We used a porcine model of allogeneic MSC and autologous BM-MNC transplantation and radionuclide labelling to track the cells. The role of the transplantation route on lung entrapment, biodistribution, safety and BM-MNC targeting to the injured brain was studied. Effects of pronase detachment on the lung passage of MSCs were studied in porcine and murine models; a rat model of acute limb injury was used to further evaluate tissue targeting. Treatment with pronase to detach cell surface molecules and the effect on stem cell potential was assessed in vitro. Intra-arterial administration of MSCs diminishes their lung deposition; intravascular transplantation did not cause pulmonary embolisms. Intra-arterially transplanted BM-MNCs did not reach the brain in significant numbers. Transient proteolytic modification of MSCs with pronase decreased lung accumulation and tissue targeting without affecting their therapeutic characteristics. Intra-arterial transplantation increases lung passage of MSCs. Although thromboembolic events were not observed, further studies are warranted to ensure the safety of this route of MSC delivery. Pronase detachment is a promising method to enhance the potential of systemic MSC therapies. / Tiivistelmä Luutytimen mesenkymaaliset kantasolut (MSC) ja mononukleaariset solut (BM-MNC) ovat osoittautuneet tehokkaiksi useissa kliinisissä käyttöaiheissa. Solujen systeeminen annostelu verenkiertoon olisi käytännön kannalta paras soluterapian toteutukseen, mutta solujen merkittävä taipumus jäädä keuhkoihin loukkuun ja veritulppariski muodostavat haasteen. Keuhkohakeutumisen tiedetään ainakin osin johtuvan solujen pintamolekyyleistä ja näiden muokkaaminen voisi parantaa solujen keuhkoläpäisevyyttä. Tutkimuksessa käytettiin koe-eläimenä sikaa, jolle istutettiin systeemisesti allogeenisia mesenkymaalisia kantasoluja tai autologisia luuytimen mononukleaarisia soluja; solujen kudoshakeutumisen seuranta toteutettiin isotooppileimauksella- ja kuvannuksella. Tutkimuksessa arvioitiin annostelureitin vaikutusta keuhkoläpäisevyyteen, solujen kudojakautumista, toimenpiteen turvallisuutta sekä mononukleaarisolujen hakeutumista vaurioituneeseen aivokudokseen. Pronaasikäsittelyn vaikutusta mesenkymaalisten kantasolujen keuhkoläpäisevyyteen arvioitiin sika- ja hiirimallissa; rotan raajavauriomallia käytettiin lisäksi pronaasin kudoshakeutumisvaikutusten arvioimiseen. Pronaasikäsittelyn vaikutuksia solujen pintarakenteisiin ja toiminnallisuuteen arvioitiin in vitro- kokeissa. Mesenkyymalisten kantasolujen annostelu valtimonsisäisesti paransi solujen keuhkoläpäisevyyttä; tutkimuksissa käytetyt solut eivät aiheuttaneet keuhkoveritulppia. Valtimonsisäisesti annostellut mononukleaarisolut eivät hakeutuneet vaurioituneeseen aivokudokseen sikamallissa. Pronaasikäsittely muovasi solujen pintaproteiineja palautuvasti ja tämä lisäsi huomattavasti mesenkymaalisten kantasolujen keuhkoläpäisevyyttä ja kudoshakeutumista vaikuttamatta solujen toiminnallisuuteen. Mesenkymaalisten kantasolujen annostelu valtimonsisäisesti voi parantaa solujen keuhkoläpäisevyyttä. Tutkimuksessa ei todettu keuhkoveritulppaa tai muita tromboembolisia tapahtumia, mutta lisätutkimuksia tarvitaan MSC- terapian turvallisuuden takaamiseksi. Pronaasikäsittelyn tulokset mesenkymaalisten kantasolujen systeemisen annostelun parantamisessa olivat lupaavia.
574

Mechanism of action of the glutaredoxins and their role in human lung diseases

Peltoniemi, M. (Mirva) 31 July 2007 (has links)
Abstract Glutaredoxins (Grx) are small thiol disulphide oxidoreductases with a conserved active site sequence -CXXC/S- and a glutathione (GSH) binding site. They catalyze the reduction of protein disulphides, preferring protein-GSH mixed disulphides as substrates. The accumulation of protein-GSH mixed disulphides has been observed during oxidative stress, where they may serve both a regulatory and an antioxidant function by protecting the enzymes from irreversible oxidation. Once oxidative stress has been removed the GSH-protein mixed disulphides are reduced by GSH or, more efficiently, by Grx. The present study showed for the first time that Grx1 and Grx2 can be detected in healthy human lung. Highly specific expression of Grx1 was observed in alveolar macrophages, but it could also be detected from sputum supernatant. Grx1 levels in alveolar macrophages were lower in selected inflammatory diseases than in control lung samples. Grx1 was also mainly negative in the fibrotic areas in usual interstitial pneumonia, an aggressive fibrotic lung disease. Overall, the present study suggests that Grx1 is a potential redox modulatory protein regulating the intracellular as well as extracellular homeostasis of glutathionylated proteins and GSH not only in healthy lung, but also in inflammatory and fibrotic lung diseases. In order to study the mechanism of action of glutaredoxins in vitro, a new real-time fluorescence-based method for measuring the deglutathionylation activity of glutaredoxins using a glutathionylated peptide as a substrate was developed. The first reaction intermediate in the deglutathionylation reaction was shown to be exclusively Grx-GSH mixed disulphide and this specificity was solely dependent on the unusual γ-linkage present in glutathione. The study also demonstrated the role of conserved residues in the proximity of proposed GSH binding site to the GSH binding specificity of E. coli Grx1. Opening the binding groove and removing charged residues enabled Grx to form more readily mixed disulfides with other molecules besides GSH. Different members of the PDI family showed considerably lower activity levels compared to glutaredoxins and, in contrast to the glutaredoxin-GSH mixed disulphide, the only intermediate in the PDI catalysed reaction was PDI-peptide mixed disulphide.
575

Identification of potential biomarkers in lung cancer as possible diagnostic agents using bioinformatics and molecular approaches

Ahmed, Firdous January 2015 (has links)
>Magister Scientiae - MSc / Lung cancer remains the leading cause of cancer deaths worldwide, with the majority of cases attributed to non-small cell lung carcinomas. At the time of diagnosis, a large percentage of patients present with advanced stage of disease, ultimately resulting in a poor prognosis. The identification circulatory markers, overexpressed by the tumour tissue, could facilitate the discovery of an early, specific, non-invasive diagnostic tool as well as improving prognosis and treatment protocols. The aim was to analyse gene expression data from both microarray and RNA sequencing platforms, using bioinformatics and statistical analysis tools. Enrichment analysis sought to identify genes, which were differentially expressed (p < 0.05, FC > 2) and had the potential to be secreted into the extracellular circulation, by using Gene Ontology terms of the Cellular Component. Results identified 1 657 statically significant genes between normal and early lung cancer tissue, with only 1 gene differentially expressed (DE) between the early and late stage disease. Following statistical analysis, 171 DE genes selected as potential early stage biomarkers. The overall sensitivity of RNAseq, in comparison to arrays enabled the identification of 57 potential serum markers. These genes of interest were all downregulated in the tumour tissue, and while they did not facilitate the discovery of an ideal diagnostic marker based on the set criteria in this study, their roles in disease initiation and progression require further analysis.
576

The effect of maternal nicotine exposure on cellular senescence in the lungs of the offspring

Salie, Yusrah January 2012 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / Several studies conducted in laboratories at the University of the Western Cape has demonstrated an interference with the parenchymal lung tissue of the offspring when exposed to nicotine (smoking cigarettes and/or Nicotine Replacement Therapy [NRT]), maternally i.e. during gestation and lactation. This in turn, decreases the amount of air sacs (alveolar number) resulting in a reduced surface area available for efficient gas exchange in the offspring. Since the foetus and offspring are only exposed to nicotine during gestation and lactation, emphysema- like lesions appear to develop after nicotine withdrawal in the foetus. It has been proposed that during lung development in utero, a change in the "program" that controls the maintenance of lung integrity will occur in the long term due to the initial maternal nicotine exposure. Therefore, animals that were exposed to maternal nicotine resemble lungs that have undergone rapid, premature aging caused by cellular senescence. Furthermore, energy metabolism and structural changes in the glycolytic pathways appear irreversibly slower compared to animals that were not exposed to nicotine via the mother during gestation and lactation, resulting in a reduction in the anti-oxidant capacity of lung development. Previous studies have also shown that strong anti-oxidants supplemented by smoking mothers during gestation and lactation could possibly resist change in the "program" which controls lung development and integrity of the offspring in the long term. Lycopene – as a strong anti-oxidant supplementation have shown to decrease the alveolar volume and increase the alveolar surface area for better gas exchange after the offspring has been exposed to maternal nicotine. In this study I have treated pregnant wistar rats with nicotine, tomato juice (containing lycopene among other phytonutrients), and a combination of nicotine and tomato juice during gestation, to determine various changes in the lung structure and signs of premature aging in the lungs of the offspring. I have also performed various staining techniques such as H&E, connective tissue and β- galactosidase staining which indicated whether maternal nicotine exposure indeed induced premature cellular senescence in the lungs of the offspring. / National Research Foundation
577

DISPARITIES IN STAGE-APPROPRIATE THERAPY FOR RESECTABLE NON-SMALL CELL LUNG CANCER IN KENTUCKY

Martin, Jeremiah T. 01 January 2017 (has links)
Lung cancer (NSCLC) is the leading cause of cancer related mortality. Lung cancer screening aims to detect treatable cancers, however survival advantage will only be seen with early and appropriate stage-directed therapy. This study aims to understand recent rates of therapy for early-stage lung cancer in Kentucky, and to explore potential sources of disparities in treatment and outcomes. A Kentucky Cancer Registry query was performed of all NSCLC cases treated in the state from 2005-2014. Of 39,763 lung cancer patients, 10,622 were clinically operable. Of these, overall 40% did not receive surgery, while 16% did not receive any stage-appropriate local therapy. Wide variation was noted in rates of surgery and local therapy at the county level. Increased age, non-private insurance status, non-white race, male gender, and non-married status were less likely to receive surgery. Median survival in patients who underwent surgery was 59.1 months vs 16 months (p< 0.001). Appropriate stage-directed local therapy is a very important factor in survival of patients with early stage NSCLC. County-level variation in rates of therapy need further study. Demographic factors continue to drive disparities in therapy and outcomes in Kentucky and should inform health policy and ongoing research and education efforts.
578

The Value of Targeted Therapies in Lung Cancer

Romanus, Dorothy 01 January 2016 (has links)
The goal of this dissertation was to examine the realized value of targeted therapies in routine care and to identify opportunities for improving the return on medical spending for these technologies. Chapter 1 investigated the value of targeted therapies in lung cancer patients who were treated in routine care. This observational, claims-based analysis used propensity score, and instrumental variable methods, combined with a Kaplan Meier Sample Average estimator to calculate lifetime costs and life expectancy. An incremental comparison showed that the realized value of targeted therapies in routine care was unfavorable relative to chemotherapy treatment. Subgroup analyses revealed that initial erlotinib therapy yielded effectiveness results that are substantially lower than efficacy survival outcomes in molecularly guided trials. Our results indicated that in routine care, chemotherapy was the most cost effective strategy. The unexpectedly low outcomes with first-line erlotinib suggested that some of the value of this treatment was not being realized in practice. Chapter 2 examined the practice patterns of targeted therapies and utilization of predictive biomarker testing in routine care to better understand the observed gaps between trial-based and `real-world' outcomes with these agents. In our nationally representative cohort of lung cancer patients, we found that the vast majority of patients did not undergo molecular testing to inform first-line therapy. Our prediction models for biomarker screening and first-line treatment suggested that phenotypic enrichment criteria guided selection for testing and initiation of erlotinib therapy. Since clinical characteristics do not adequately discriminate between mutation positive and wild type tumors, these practices signal the need for wider dissemination of biomarker screening to accurately target patients towards improving therapeutic gains with erlotinib. Chapter 3 assessed the cost-effectiveness of multiplexed predictive biomarker screening to inform treatment decisions in lung cancer patients. Using a micro-simulation model to evaluate the incremental value of molecularly guided therapy compared to chemotherapy in unselected patients, we found that personalized therapy is a cost effective strategy. Our results indicated that better value of targeted therapies in lung cancer is achievable through molecularly guided treatment.
579

DEFINITIVE PRIMARY THERAPY IN PATIENTS PRESENTING WITH OLIGOMETASTATIC NON-SMALL CELL LUNG CANCER (NSCLC)

Parikh, Ravi B 01 November 2014 (has links)
Background: Although palliative chemotherapy is the standard of care for patients diagnosed with stage IV NSCLC, patients with a small metastatic burden, “oligometastatic” disease, may benefit from definitive local therapy. Methods: We identified 186 patients (26% of Stage IV patients) prospectively enrolled in our institutional database from 2002-2012 with oligometastatic disease, which we defined as five or fewer distant metastatic lesions at diagnosis. Univariable and multivariable Cox proportional hazards models were used to identify patient and disease factors associated with improved survival. Using propensity score methods, we investigated the effect of definitive local therapy to the primary site on overall survival. Results: Median age at diagnosis was 61 years, 51% of patients were female, 12% had squamous histology, and 33% had N0-1 disease. On multivariable analysis, ECOG performance status ≥2 (hazard ratio [HR] 2.43), nodal status N2-3 (HR 2.16), squamous pathology, and metastases to multiple organs (HR 2.11) were associated with a greater hazard of death (all p<0.01). Number of metastatic lesions and size of primary were not significantly associated with overall survival. Definitive local therapy to the primary tumor was associated with prolonged survival (HR 0.65, p=0.043). Conclusions: Definitive local therapy to the primary tumor appears to be associated with improved survival in patients with oligometastatic NSCLC. Select patient and tumor characteristics, including good performance status, non-squamous histology, and limited nodal disease, may predict for improved survival in these patients.
580

Environmental Risk Factors for Lung Cancer Mortality in the Cancer Prevention Study-II

Turner, Michelle C January 2012 (has links)
This thesis examined associations between ecological indicators of residential radon and fine particulate matter air pollution (PM2.5) and lung cancer mortality using data from the American Cancer Society Cancer Prevention Study-II (CPS-II) prospective cohort. Nearly 1.2 million CPS-II participants were recruited in 1982. Mean county-level residential radon concentrations were linked to study participants according to ZIP code information at enrollment (mean (SD) = 53.5 (38.0) Bq/m3). Cox proportional hazards regression models were used to obtain adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for lung cancer mortality associated with radon. After necessary exclusions, a total of 811,961 participants in 2,754 counties were retained for analysis. A significant positive linear trend was observed between categories of radon concentrations and lung cancer mortality (p = 0.02). A 15% (95% CI 1 - 31%) increase in the risk of lung cancer mortality was observed per each 100 Bq/m3 radon. Radon was also positively associated with chronic obstructive pulmonary disease mortality (HR per each 100 Bq/m3 = 1.13, 95% CI 1.05 - 1.21). No clear associations were observed between radon and non-respiratory mortality. In lifelong never smokers (n = 188,699), each 10 µg/m3 increase in mean metropolitan statistical area PM2.5 concentrations was associated with a 15-27% increase in the risk of lung cancer death which strengthened among individuals with a history of asthma or any prevalent chronic lung disease at enrollment (p for interaction < 0.05). There was no association between PM2.5 and mortality from non-malignant respiratory disease. In conclusion, this thesis observed significant positive associations between ecological indicators of residential radon and PM2.5 concentrations and lung cancer mortality. These findings further support efforts to reduce radon concentrations in homes to the lowest possible level and strengthens the evidence that ambient concentrations of PM2.5 measured in recent decades are associated with small but measurable increases in lung cancer mortality. Further research is needed to better understand possible complex inter-relationships between environmental risk factors, chronic lung disease, and lung cancer.

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