The COVID-19 pandemic elucidated geographical disparities in COVID-19 burden on a globalscale. Geographical disparities in adverse COVID-19 outcomes may suggest population-level drivers of disease, such as environmental exposures. Epidemiological literature provides strong evidence that greater exposure to ambient air pollution, an environmental exposure, is associated with a greater risk of COVID-19 hospitalization and fatality. The pathways by which ambient air pollution exposure influences adverse COVID-19 outcomes are currently unknown. I propose that cardiovascular morbidity is relevant in this pathway, given that cardiovascular morbidity is a predominant risk factor of adverse COVID-19 outcomes, and there are strong and consistent associations between air pollution and cardiovascular morbidity. I suggest that the role of cardiovascular morbidity will be different for historical air pollution (period > 30 days) and short-term air pollution (period < 30 days). By proposing clear causal structures for the relationship between air pollution and adverse COVID-19 outcomes, we can explicate how air pollution leads to greater COVID-19 burden and address the larger goal of reducing geographic disparities in adverse COVID-19 outcomes. This dissertation is comprised of three specific aims. For the first aim, I performed a systematic review of the literature that examined the relationship between ambient air pollution and individual-level adverse COVID-19 outcomes. I identified if and how researchers conceptualized the causal role of comorbidities, specifically cardiovascular morbidities, in the relationship between air pollution and adverse COVID-19 outcomes. For the second aim, I examined if cardiovascular morbidity mediates the relationship between historical air pollution and adverse COVID-19 outcomes. For the third aim, I examined if there was evidence of synergistic interaction between short-term air pollution and cardiovascular morbidity in influencing the risk of adverse COVID-19 outcomes, suggesting that the effect of both short-term air pollution and cardiovascular morbidity on adverse COVID-19 is greater than the sum of the individual effects. In conducting the first aim, I used Covidence, a software used to manage systematic reviewstudies, to identify studies that examined the relationship between ambient air pollution exposure and individual-level adverse COVID-19, using the Embase, MEDLINE, and Web of Science databases. In conducting the empirical aims, I used a retrospective cohort study design using INSIGHT-Clinical Research Network (CRN) data, a harmonized repository of inpatient electronic health records in New York City (NYC) across metropolitan healthcare systems (3/1/2020-2/28/2021). INSIGHT-CRN included data pertaining to sociodemographics, diagnoses, outcomes, and residential ZIP Code to link air pollution exposure. For the second aim, I used the New York City Community Air Survey (NYCCAS) to estimate historical air pollution exposure to particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO₂), and ozone (O₃) on a ZIP Code level (2009-2019). For the third aim, I used the 2020 Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) downscaler modeled data, which estimated 2020 daily exposure to PM2.5 and O3 on a census tract level. I aggregated the census tract data to ZIP Code using a spatial weighting approach and estimated short-term air pollution as a 7-day average of daily PM2.5 and O3 exposure prior to patient hospitalization. For the first aim, the systematic review included 42 studies that examined the relationship between ambient air pollution, such as exposures to PM2.5, NO₂, and O₃, and individual-level adverse COVID-19, such as hospitalization, intensive care unit (ICU) admission, intensive respiratory support (IRS), and fatality. The studies were primarily retrospective cohort study designs, and were conducted in the United States and Europe (2020 to 2021). The majority of studies adjusted for cardiovascular morbidity without causal role specification, whereas some studies identified cardiovascular morbidity as a mediator or an effect modifier. For the second aim, I found evidence of cardiovascular morbidity mediating the relationship between historical air pollution and risk of acute respiratory distress syndrome (ARDS), dialysis use, ventilation use, and COVID-19 fatality, but not risk of pneumonia from March to June 2020, within areas of greater hospital catchment. Indirect effects suggest that historical air pollution increases the risk of atrial fibrillation and myocardial infarction, which increases risk of adverse COVID-19. For the third aim, I found evidence of synergistic interaction between short-term PM2.5 and presence of cardiovascular morbidities for only risk of COVID-19 pneumonia, in the latter half of 2020. Overall, there was evidence that cardiovascular morbidity mediates the relationship betweenhistorical air pollution and more severe COVID-19 outcomes, while cardiovascular morbidity synergistically interacts with short-term air pollution for risk of acute respiratory infections, such as pneumonia. This dissertation assesses the pathways by which air pollution may influence risk of adverse COVID-19, in better examining the causal role of cardiovascular morbidity. Knowledge gained could be used to mitigate population-level vulnerabilities to air pollution, and encourage population-level pandemic preparedness in the future.

Indiana University-Purdue University Indianapolis (IUPUI) / With effective antiretroviral therapy (ART), cardiovascular diseases (CVD), are emerging as a major cause of morbidity and death in the aging population with HIV infection. Although this increase in CVD could be partially explained by the toxic effects of combined anti-retroviral therapy (ART), more recently, HIV infection has emerged as an independent risk factor for CVD. However, it is unclear how HIV can contribute to CVD in patients on ART, when viral titers are low or non-detectable. Here, we provide several lines of evidence that HIV-Nef, produced in infected cells even when virus production is halted by ART, can lead to endothelial activation and dysfunction, and thus may be involved in CVD. We demonstrate that HIV-infected T cell-induced endothelial cell activation requires direct contact as well as functional HIV-Nef. Nef protein from either HIV-infected or Nef-transfected T cells rapidly transfers to endothelial cells while inducing nanotube-like conduits connecting T cells to endothelial cells. This transfer or transfection of endothelial cells results in endothelial apoptosis, ROS generation and release of monocyte attractant protein-1 (MCP-1). A Nef SH3 binding site mutant abolishes Nef-induced apoptosis and ROS formation and reduces MCP-1 production in endothelial cells, suggesting that the Nef SH3 binding site is critical for Nef effects on endothelial cells. Nef induces apoptosis of endothelial cells through both NADPH oxidase- and ROS-dependent mechanisms, while Nef-induced MCP-1 production is NF-kB dependent. Importantly, Nef can be found in CD4 positive and bystander circulating blood cells in patients receiving virally suppressive ART, and in the endothelium of chimeric SIV-infected macaques. Together, these data indicate that Nef could exert pro-atherogenic effects on the endothelium even when HIV infection is controlled and that inhibition of Nef-associated pathways may be promising new therapeutic targets for reducing the risk for cardiovascular disease in the HIV-infected population.

Indiana University-Purdue University Indianapolis (IUPUI) / Epidemiological studies suggest that depression may be an independent risk factor for cardiovascular disease (CVD). Although several possible mediators of this association have been proposed, the precise mechanisms are yet unknown. Accordingly, we examined periodontal disease as a novel mediator of the depression-CVD association, given its separate links with both depression and CVD. Data from the National Health and Nutrition Examination Survey (NHANES) I and its Epidemiologic Follow-up Study (NHEFS) were analyzed. Participants were 3,346 individuals aged 25-74 years free of CVD at baseline (53% female, 16% non-white). Depression was assessed by the, depressed mood subscale of the General Well-Being Schedule Based on the Russell Periodontal Index, periodontal disease (43%) was defined as the presence of four or more periodontal pockets identified by a licensed dentist during an examination. The primary outcome was incident CVD (n=727, 22%), defined as nonfatal or fatal coronary artery disease or cerebrovascular disease, identified during the follow-up period by interviews and death certificate records. All analyses were adjusted for demographic and cardiovascular risk factors. Logistic regression analyses revealed no association between the GWBS depressed mood score and periodontal disease (OR=1.05, 95% CI: 0.96-1.14, p=.24). Cox proportional hazard models revealed that both periodontal disease (HR=1.24, 95% CI: 1.06-1.46, p=.009) and depressed mood (HR=1.08, 95% CI: 1.01-1.17, p=.03) were significant predictors of incident CVD. However, Sobel analyses found that periodontal disease was not a partial mediator of the depressed mood-incident CVD association (t=1.01, p=.31). Overall, these mediation results suggest that (a) both periodontal disease and depressed mood are independent predictors of incident CVD and that (b) the effect of depressive symptoms on incident CVD is not mediated by periodontal disease.

Dissertation / The aim of this study was to determine the knowledge of persons with hypertension in a selected geographical area regarding cardiovascular risk factors in order to make recommendations for patient education. A quantitative, non-experimental, descriptive study was done in the form of a survey using a questionnaire as measuring instrument. The population was hypertensive patients from selected private medical practices in the western part of KwaZulu-Natal and the bordering eastern part of the Free State. Convenience sampling was used and 46 respondents participated in the study. Only 16 (35%) of the respondents achieved a percentage on or above the competency indicator of 50%. Respondents performed worst in questions where definitions, for example hypertension, were assessed. Recommendations for a patient education document, nursing practice and further research were made. / Health Studies / M.A. (Health Studies)

Dissertation (PhD)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Activation of the NO-cGMP pathway is associated with myocardial protection against ischaemia/reperfusion injury. However, high-cholesterol diets alter function of this pathway and these alterations have been implicated in both ischaemic/reperfusion injury and the development of ischaemic heart disease. Little is known about the effects of supplements such as Red Palm Oil (RPO) on the myocardial NO-cGMP-signalling pathway. RPO consists of saturated, mono-unsaturated and poly-unsaturated fatty acids and is rich in antioxidants such as β-carotene and Vitamin E (tocopherols and tocotrienols). The aims of this study were: 1) to determine whether dietary RPO-supplemention protects against ischaemia/reperfusion injury in rats fed a standard rat chow (control) and cholesterol-enriched diets and 2) if so, to investigate possible mechanisms for this protection. Male Long-Evans rats were fed a standard rat chow or a standard rat chow plus cholesterol and/or RPO-supplementation for 6 weeks. Myocardial functional recovery was measured and hearts were freeze-clamped for determination of myocardial phospholipid, cAMP/cGMP concentrations, total myocardial nitric oxide concentrations, lipid hydroperoxide production and superoxide dismutase- and nitric oxide synthase activity in isolated rat hearts subjected to 25 minutes of normothermic total global ischaemia. In addition, the degree of phosphorylation of extracellular signal-regulated kinase (ERK), p38, c-Jun N-terminal protein kinase (JNK) and protein kinase B (PKB/Akt) was investigated. Furthermore, the effect of RPO-supplementation on caspase-3 activation and poly (ADP-ribose) polymerase (PARP)-cleavage in hearts subjected to ischaemia and reperfusion was also investigated. Our data show that dietary RPO-supplementation protects the hearts of rats on a standard rat chow (control) and hypercholesterolaemic diet against ischaemia/reperfusion injury as reflected by improved aortic output recovery. Increased intracellular cardiomyocyte NO concentrations as observed in control hearts supplemented with RPO after 120 minutes hypoxia may contribute to the elevated cGMP concentration and may confer some of the cardioprotection to the ischaemic/reperfused heart. Although improved functional recovery with RPO-supplementation of a high-cholesterol diet was also associated with an increase in intracellular cardiomyocyte NO production after hypoxia compared to the non-hypoxic conditions, it could not be linked to increased NO-cGMP signalling. These data are in agreement with other studies, which showed that high-cholesterol diet impairs NO-cGMP signalling and confirms our hypothesis that elevated cGMP concentrations may not be the only mechanism of protection. We have also shown that RPOsupplementation caused increased phosphorylation of p38 and PKB, reduced phosphorylation of JNK and attenuation of PARP cleavage, which may contribute to the protection of the cell against apoptosis. Based on our results we propose that the myocardial protection offered by RPO-supplementation of rats on a normal and hypercholesterolaemic diet may be associated with either its antioxidant characteristics and/or changes in the fatty acid composition of the myocardium during ischaemia/reperfusion. Furthermore, we demonstrated for the first time that RPO-supplementation protects the isolated perfused working rat heart during reperfusion from ischaemia/reperfusion-induced injury through a MAPK-dependent pathway. / AFRIKAANSE OPSOMMING: Aktivering van die NO-cGMP sein transduksie pad word geassosieer met miokardiale beskerming teen isgemie/herperfusie skade. Hoë cholesterol diëte verander egter die funksie van die pad en hierdie veranderings speel ‘n rol in beide isgemie/herperfusie besering en die ontwikkeling van isgemiese hartsiekte. Daar is egter min inligting beskikbaar oor die uitwerking van aanvullings soos rooi palm olie (RPO) op die miokardiale NO-cGMP sein transduksie pad. RPO bevat versadigde, mono-onversadigde en poli-onversadigde vetsure en is ryk aan anti-oksidante nl. β-karotene en vitamien E (tokoferole en tokotriënole). Die doelwitte van hierdie studie was: 1) om vas te stel of ‘n RPO-aanvulling beskerming bied teen isgemie/herperfusie besering in rotte wat gevoed is met ‘n standaard rotmengsel (kontrole) en cholesterol-verrykte dieet en 2) indien wel, om moontlike meganismes van beskerming te ondersoek. Long-Evans manlike rotte is vir 6 weke gevoer met ‘n standaard rotmengsel of ‘n standaard rotmengsel plus cholesterol en/of RPO-aanvulling. Miokardiale funksionele herstel is gemeet en harte is gevriesklamp vir die bepaling van miokardiale fosfolipied, cAMP/cGMP, totale stikstofoksied, lipied hidroperoksied, superoksied dismutase en stikstofoksied sintase in geïsoleerde rotharte wat vir 25 minute onderwerp was aan normotermiese totale globale isgemie. Hiermee saam is die graad van fosforilering van ekstrasellulêre sein gereguleerde kinase (ERK), p38 mitogeen-geaktiveerde proteïen kinase (p38 MAPK), c-Jun-N-terminale proteïenkinase (JNK) en proteïen kinase B (PKB/Akt) ondersoek, asook kaspase-3 aktivering en poli (ADP-ribose) polimerase (PARP) kliewing in harte blootgestel aan isgemie en herperfusie. Ons resultate toon dat RPO-aanvulling van rotte op ‘n normale en hipercholesterolemiese dieet die hart beskerm soos getoon deur verbeterde herstel van aortiese uitset. Verhoogde intrasellulêre miokardiale NO vlakke in kontrole harte met ‘n RPO-aanvulling wat blootgestel was aan 120 minute hipoksie, mag bygedra het tot die verhoogde cGMP vlakke en beskerming van die hart tydens isgemie en herperfusie. Alhoewel verbeterde funksionele herstel met RPO-aanvulling van ‘n hoë cholesterol dieet ook geassosieer is met ‘n toename in intrasellulêre miokardiale NO produksie ná hipoksiese toestande, kon dit nie verbind word met verhoogde aktivering van die NOcGMP sein transduksie pad nie. Hierdie resultate stem ooreen met ander studies wat aangetoon het dat hoë-cholesterol diëte die NO-cGMP seinpad onderdruk. Hierdie bevinding bevestig ons hipotese dat verhoogde cGMP vlakke moontlik nie die enigste beskermingsmeganisme is nie. Ons resultate het ook gewys dat RPO-aanvulling fosforilering van p38 en PKB/Akt verhoog, fosforilering van JNK verminder en PARP kliewing onderdruk. Dit dui op beskerming van die sel teen apoptose. Ons resultate dui aan dat die miokardiale beskerming wat RPO-dieet aanvulling bied moontlik geassosieer kan word met sy anti-oksidant eienskap en/of veranderinge in die vetsuur samestelling van die miokardium tydens isgemie/herperfusie. Ons het ook vir die eerste keer bewys dat RPO-aanvulling die geïsoleerde geperfuseerde werkende rothart gedurende herperfusie beskerm teen isgemie/herperfusie besering deur die aktivering en/of deaktivering van die MAPK afhanklike pad.

Dissertation / The aim of this study was to determine the knowledge of persons with hypertension in a selected geographical area regarding cardiovascular risk factors in order to make recommendations for patient education. A quantitative, non-experimental, descriptive study was done in the form of a survey using a questionnaire as measuring instrument. The population was hypertensive patients from selected private medical practices in the western part of KwaZulu-Natal and the bordering eastern part of the Free State. Convenience sampling was used and 46 respondents participated in the study. Only 16 (35%) of the respondents achieved a percentage on or above the competency indicator of 50%. Respondents performed worst in questions where definitions, for example hypertension, were assessed. Recommendations for a patient education document, nursing practice and further research were made. / Health Studies / M.A. (Health Studies)

Heart disease including ischemic heart disease is the highest contributor to death and morbidity in the western world. The studies presented were conducted to determine possible pathways of protection of the heart against ischemia/reperfusion. We employed adenovirus mediated over-expression of Methionine sulfoxide reductase A (MsrA) in primary neonatal rat cardiac myocytes to determine the effect of this enzyme in protecting against hypoxia/reoxygenation. Cells transfected with MsrA encoding adenovirus and subjected to hypoxia/reoxygenation exhibited a 45% decrease in apoptosis as compared to controls. Likewise total cell death as determined by levels of Lactate Dehydrogenase (LDH) release was dramatically decreased by MsrA overexpression. The initial hypothesis that led to our testing sulindac was based on the fact that the S epimer of sulindac was a substrate for MsrA and that this compound might function as a catalytic anti-oxidant based on a reaction cycle that involved reductio n to sulindac sulfide followed by oxidation back to sulindac. To test this we examined the protective effect of sulindac in hypoxia re-oxygenation in both cardiac myocytes in culture and using a Langendorff model of myocardial ischemia. Using this model of myocardial ischemia we showed that pre-incubation of hearts with sulindac, or the S and R epimers of sulindac resulted in protection against cell death. We present several lines of evidence that the protective effect of sulindac is not dependent on the Msr enzyme system nor does it involve the well established role of sulindac as a Cyclooxygenase (COX) inhibitor. Numerous signaling pathways have been implicated in myocardial protective mechanisms, many of which require fluctuations in ROS levels as initiators or mediators. / Sulindac shows very good potential as a preconditioning agent that could induce tissue protection against oxidative damage.Blocking of preconditioning pathways by administration of the PKC blocker chelerythine abrogated the ischemic protection afforded by sulindac. Secondly, an end-effector of preconditioning, inducible nitric oxide synthase (iNOS),was found to be induced by greater than 5 fold after 48 h prior feeding sulindac. / by Ian Moench. / Thesis (Ph.D.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Background: This dissertation comprises research conducted on two distinct projects. Project I focuses on the connection between household air pollution (HAP) from cooking with biomass fuels and blood pressure (BP); this research is situated in the context of a large randomized trial of a cookstove intervention in Ghana, West Africa. The setting of Project II, meanwhile, is the residential environment of New York City, where we explore temperature and humidity conditions in homes and relate these conditions to summertime heat wave risk and to the survival and transmission of respiratory viruses in the winter. Although these projects are quite distinct, each relates to the complex relationship between climate change and health. Reducing HAP to improve health (the focus of Project I) will simultaneously reduce climate change through a reduction in emissions of short-lived climate pollutants into the atmosphere. Meanwhile, furthering our understanding of heat and humidity levels inside urban residences (the focus of Project II) is crucial to our ability to protect health in light of projections for a changing climate. Domestic activities associated with heating, cooling, and cooking are thus very relevant both to human health and to climate change mitigation and adaptation. Objectives and Methods: Our overall objective for Project I was to investigate exposure- response relationships between HAP and BP in a cohort of pregnant women taking part in the Ghana Randomized Air Pollution and Health Study (GRAPHS). We first explored this association in a cross-sectional study (Chapter 1), in which we used 72-hour personal monitoring to ascertain levels of exposure among the GRAPHS women to carbon monoxide (CO), one of the pollutants emitted by traditional wood-fed cooking fires. These exposure data were collected at enrollment into the GRAPHS study, prior to the initiation of cooking with improved cookstoves. We investigated the association between these “baseline” CO exposure levels and the women’s blood pressure at enrollment into GRAPHS. A limitation of this study was that BP was only measured once. We followed this with a second study of 44 women drawn from the same cohort (Chapter 2), for whom we designed BP protocols using 24-hour ambulatory blood pressure monitoring (ABPM), the current gold standard for clinical diagnosis of hypertension. As we were not aware of any prior research in Africa that had employed ABPM, we also designed a parallel BP protocol using home blood pressure monitoring (HBPM) equipment for comparison with ABPM. The use of ABPM with concurrent personal CO monitoring enabled us to investigate hourly associations between CO exposure and changes in BP. We also evaluated BP in these women both before and after the cookstove intervention; this allowed us to investigate whether any changes in BP were associated with switching to an improved cookstove. Our objectives for Project II were to understand the distribution of temperature and humidity conditions in a range of New York City homes during the summer and winter seasons, to evaluate the impact of structural and behavioral factors (e.g. building size, use of air conditioning, and use of humidifiers) on these conditions, and to build models that could help predict indoor conditions from more readily available outdoor measurements. We conducted this research in two ways. We first analyzed a set of indoor temperature and humidity measurements that were collected in 285 New York City apartments during portions of summers 2003-2011 and used these data to simulate indoor conditions during two heat wave scenarios, one of which was more moderate and the other of which was more extreme (Chapter 3). Second, we designed and conducted a new study in which temperature and humidity were monitored in a set of 40 NYC apartments between 2013 and 2015 (Chapters 4-6). This second study enabled us extend our research into the winter season, and also to explore how factors such as air conditioning and humidifier use impacted indoor temperature and humidity. We also investigated relationships between the monitored conditions, self-reported perceptions of the indoor environment, and symptoms that were experienced among household members. Results: In the cross-sectional analysis of CO and BP in the GRAPHS cohort (Chapter 1), we found a significant positive association between CO exposure and diastolic blood pressure (DBP): on average, each 1 ppm increase in exposure to CO was associated with 0.43 mmHg higher DBP [0.01, 0.86]. A non-significant positive trend was also observed for systolic blood pressure (SBP). In our study of the acute relationship between CO exposure and BP (Chapter 2), we determined that peak CO exposure (defined as above the 90th percentile of the exposure distribution, or an average of 4.1ppm) in the two hours prior to BP measurement was associated with elevations in hourly systolic BP (4.3 mmHg [95% CI: 1.1, 7.4]) and diastolic BP (4.5 mmHg [95% CI: 1.9, 7.2]), as compared to BP following lower CO exposures. We also observed a non-significant trend toward lower BP following initiation of cooking with an improved cookstove. Lastly, we demonstrated that ABPM was a feasible and well-tolerated tool for BP assessment in a rural West African setting. For Project II in New York City, we first determined that there was a great deal of variability in indoor summer heat index (HI) between homes in association with similar outdoor conditions, and that this variability increased with increasing outdoor heat (Chapter 3). Our simulation of a moderate heat wave led us to conclude that the hottest 5% of the homes would reach peak indoor heat index (HI) values of 39°C. In a more extreme heat wave simulation, HI in the hottest 5% of homes reached a peak of 41oC and did not drop below 34oC for the entire nine- day simulated heat wave period. Our second indoor monitoring study yielded the following findings: in the summer season (Chapter 4), we found significant differences in indoor temperature and heat index according to the type of air conditioning (AC) in the home. Homes with central AC were the coolest, followed by homes with ductless AC, window AC, and no AC. Apartments on the top floor of a building were significantly hotter than other apartments regardless of the presence of AC. During the winter season (Chapter 5), median vapor pressure in our sample of apartments was 6.5mb. Comparing humidity levels in the apartments to a threshold of 10mb vapor pressure that has been proposed as protective against influenza virus transmission, levels of absolute humidity in the homes remained below this threshold for 86% of the winter: a total of over three months. Residential use of humidifiers was not associated with higher indoor humidity levels. Larger building size (above 100 units) was significantly associated with lower humidity, while the presence of a radiator heating system was non-significantly associated with higher humidity. Lastly, perceptions of indoor temperature and measured temperature were significantly associated in both the summer and the winter (Chapter 6), while sleep quality was inversely related to measured indoor temperature in the summer season only. Reports of heat- stress symptoms were associated with perceived, but not measured, temperature in the summer season. Conclusions: The work presented in this dissertation adds to a growing body of evidence on the importance of exposures in the domestic environment to health and well-being. The research reported here on household air pollution in Ghana documents an exposure-response relationship between air pollution from cookstoves and elevations in blood pressure, on both a chronic and an acute basis. As elevated BP is a known risk factor for cardiovascular disease (CVD), our research provides support for a plausible factor linking HAP exposure to CVD. Meanwhile, our research on temperature and humidity in New York City residences provides concrete data to supplement the very slim literature to date documenting these conditions in the home environment, where Americans spend over half their time. We conclude, first, that AC may not be fully protective against summertime heat risk, and second, that the levels of humidity we observed in residential environments are consistent with levels that have been shown to promote enhanced survival and transmission of respiratory viruses in experimental settings. We suggest that interventions that can reduce exposure to household air pollution and excess indoor heat can also mitigate climate change, and that with thoughtful planning we can improve health at the same time as we foster resiliency in the face of a changing climate.

Ng Chi Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 147-160). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.I / ABSTRACT --- p.II / LIST OF ABBREVIATIONS --- p.VII / TABLE OF CONTENTS --- p.IX / Chapter CHAPTER 1 --- GENERAL INTRODUCTION / Chapter 1.1 --- Introduction of Low-density lipoprotein --- p.1 / Chapter 1.1.1 --- What are lipids? --- p.1 / Chapter 1.1.2 --- Function and structure of cholesterol --- p.1 / Chapter 1.1.3 --- Function and classification of lipoprotein --- p.1 / Chapter 1.2 --- Functions of low-density lipoprotein --- p.2 / Chapter 1.3 --- Basic structure of low-density lipoprotein --- p.4 / Chapter 1.4 --- Principle on isolation and purification of low-density lipoprotein --- p.4 / Chapter 1.5 --- Cholesterol transport system --- p.7 / Chapter 1.5.1 --- Exogenous pathway of cholesterol metabolism --- p.7 / Chapter 1.5.2 --- Endogenous pathway of cholesterol metabolism --- p.7 / Chapter 1.5.3 --- Reverse transport of Cholesterol --- p.8 / Chapter 1.6 --- Oxidation of LDL --- p.10 / Chapter 1.6.1 --- Agents that causes oxidation --- p.10 / Chapter 1.6.1.1 --- Lipoxygenases --- p.10 / Chapter 1.6.1.2 --- Myeloperoxidase --- p.10 / Chapter 1.6.1.3 --- Reactive nitrogen species --- p.11 / Chapter 1.6.1.4 --- Reactive oxygen species --- p.11 / Chapter 1.6.2 --- Factors that affect the susceptibility of LDL oxidation --- p.13 / Chapter 1.7 --- Hyperlipidaemia 一 chance to increase LDL oxidation --- p.13 / Chapter 1.7.1 --- Definition of hyperlipidemia and hypercholesterolemia --- p.13 / Chapter 1.7.2 --- Risk factors of hyperlipidaemia --- p.13 / Chapter 1.7.2.1 --- High fat low fibre diets: --- p.13 / Chapter 1.7.2.2 --- Obesity --- p.14 / Chapter 1.7.2.3 --- Type II diabetes --- p.14 / Chapter 1.7.2.4 --- Genetic factors (Familial hyperlipidemias) --- p.14 / Chapter 1.8 --- Diseases related to oxidized LDL --- p.15 / Chapter 1.8.1 --- Cardiovascular diseases --- p.15 / Chapter 1.8.1.1 --- Atherosclerosis and ischemic heart attack --- p.15 / Chapter 1.8.1.2 --- Factors that affect incidence of atherosclerosis --- p.16 / Chapter 1.8.1.2.1 --- Triglyceride-rich lipoprotein --- p.16 / Chapter 1.8.1.2.2 --- Small and dense LDL --- p.16 / Chapter 1.8.1.3 --- Stroke --- p.17 / Chapter 1.8.2 --- Common ways to reduce plasma cholesterol level --- p.17 / Chapter 1.8.2.1 --- Diet control --- p.17 / Chapter 1.8.2.2 --- Physical activity --- p.17 / Chapter 1.8.2.3 --- Drug therapy --- p.18 / Chapter CHAPTER 2 --- IMPAIRMENT OF OXIDIZED LDL ON ENDOTHELIUM-DEPENDENT RELAXATION / Chapter 2.1 --- Introduction --- p.19 / Chapter 2.1.1 --- Properties and function of phenylephrine hydrochloride --- p.22 / Chapter 2.1.2 --- Properties and function of acetylcholine --- p.22 / Chapter 2.2 --- Objectives --- p.23 / Chapter 2.3 --- Materials and methods --- p.24 / Chapter 2.3.1 --- Preparation of drugs --- p.24 / Chapter 2.3.2 --- Preparation of human native LDL --- p.25 / Chapter 2.3.3 --- Preparation of oxidized LDL --- p.27 / Chapter 2.3.4 --- Preparation of aorta --- p.27 / Chapter 2.3.5 --- Measurement of Isometric Force in vitro --- p.30 / Chapter 2.3.5.1 --- Protocol 1- Dose effect of oxidized LDL on acetylcholine-induced vasorelaxation --- p.30 / Chapter 2.3.5.2 --- Protocol 2 - Time effect of oxidized LDL on acetylcholine-induced vasorelaxation --- p.30 / Chapter 2.3.5.3 --- Protocol 3 - Effect of co-incubation of LDL and copper(ll) sulphate on acetylcholine-induced vasorelaxation --- p.31 / Chapter 2.3.5.4 --- Protocol 4 - Effect of oxidized LDL on selected vasodilators --- p.32 / Chapter 2.3.5.5 --- Protocol 5 - Effect of pretreatment of L-arginine on oxidized LDL impaired -endothelium-induced relaxation --- p.32 / Chapter 2.3.5.6 --- Protocol 6 - Effect of a -tocopherol on oxidized LDL-damaged acetylcholine- induced vasorelaxation --- p.33 / Chapter 2.3.5.7 --- Protocol 7 - Effect of a -tocopherol on LDL and copper(ll) sulphate- induced endothelial dysfunction --- p.33 / Chapter 2.3.6 --- Western blot analysis of endothelial nitric oxide synthase (eNOS) protein --- p.34 / Chapter 2.3.7 --- Statistics --- p.35 / Chapter 2.4 --- Results --- p.36 / Chapter 2.4.1 --- Dose effect of oxidized LDL on acetylcholine-induced vasorelaxation --- p.36 / Chapter 2.4.2 --- Time effect of oxidized LDL on acetylcholine-induced vasorelaxation --- p.36 / Chapter 2.4.3 --- Effect of co-incubation of LDL and copper(II) sulphate on acetylcholine- induced vasorelaxation --- p.39 / Chapter 2.4.4 --- Effect of oxidized LDL on selected vasodilators --- p.41 / Chapter 2.4.5 --- Effect of pretreatment of L-arginine on oxidized LDL impaired- acetylcholine-induced relaxation --- p.41 / Chapter 2.4.6 --- Effect of a-tocopherol on oxidized LDL-damaged acetylcholine- induced vasorelaxation --- p.48 / Chapter 2.4.7 --- Effect of a-tocopherol on LDL and copper(II) sulphate-induced endothelial dysfunction --- p.50 / Chapter 2.4.8 --- eNOS Protein expression --- p.50 / Chapter 2.5 --- Discussion --- p.53 / Chapter CHAPTER 3 --- EFFECTS OF LDL INJECTION ON THE ENDOTHELIAL FUNCTION OF RATS / Chapter 3.1 --- Introduction --- p.58 / Chapter 3.2 --- Objective --- p.60 / Chapter 3.3 --- Methods and Materials --- p.61 / Chapter 3.3.1 --- Preparation of Drugs --- p.61 / Chapter 3.3.2 --- Preparation of LDL --- p.61 / Chapter 3.3.3 --- Animal Treatment --- p.61 / Chapter 3.3.4 --- Serum lipid and lipoprotein determinations --- p.62 / Chapter 3.3.5 --- Measurement of serum MDA level by TBARS assay --- p.62 / Chapter 3.3.6 --- Preparation of aorta --- p.62 / Chapter 3.3.7 --- Organ bath experiment --- p.63 / Chapter 3.3.8 --- Statistics --- p.64 / Chapter 3.4 --- Result --- p.65 / Chapter 3.4.1 --- Growth and food intake --- p.65 / Chapter 3.4.2 --- "Effect of LDL injection on serum TC, TG and HDL-C" --- p.65 / Chapter 3.4.3 --- Effect of LDL injection on non-HDL-C and ratio of non-HDL-C to HDL-C --- p.65 / Chapter 3.4.4 --- Serum MDA level --- p.68 / Chapter 3.4.5 --- Phenylephrine-induced contraction --- p.70 / Chapter 3.4.6 --- Endothelium-dependent and -independent relaxation --- p.75 / Chapter 3.5 --- Discussion --- p.79 / Chapter CHAPTER 4 --- EFFECTS OF INDIVIDUAL COMPONENT OF OXIDIZED LDL ON ENDOTHELIUM-DEPENDENT RELAXATION / Chapter 4.1 --- Introduction --- p.83 / Chapter 4.2 --- Objectives --- p.85 / Chapter 4.3 --- Materials and methods --- p.86 / Chapter 4.3.1 --- Preparation of drugs --- p.86 / Chapter 4.3.2 --- Preparation of human native LDL and oxidized LDL --- p.86 / Chapter 4.3.3 --- GC analysis of fatty acid composition in LDL --- p.86 / Chapter 4.3.4 --- TBARS assay analysis of MDA content in LDL --- p.87 / Chapter 4.3.5 --- GC analysis of cholesterol oxidation products in LDL --- p.89 / Chapter 4.3.6 --- Thin-layer chromatography analysis of LPC in LDL --- p.91 / Chapter 4.3.7 --- Preparation of aorta --- p.92 / Chapter 4.3.8 --- Measurement of Isometric Force in vitro --- p.92 / Chapter 4.3.8.1 --- Protocol 1- effect of LPC on acetylcholine-induced vasorelaxation --- p.92 / Chapter 4.3.8.2 --- Protocol 2- effect of cholesterol oxidation products on acetylcholine-induced vasorelaxation --- p.92 / Chapter 4.3.8.3 --- Protocol 3- effect of oxidized fatty acids on acetylcholine-induced vasorelaxation --- p.93 / Chapter 4.3.9 --- Statistics --- p.93 / Chapter 4.4 --- Results --- p.94 / Chapter 4.4.1 --- Compositional differences between native LDL and oxidized LDL.… --- p.94 / Chapter 4.4.2 --- Effect of LPC on endothelium-dependent relaxation --- p.98 / Chapter 4.4.3 --- Effect of COPs on endothelium-dependent relaxation --- p.98 / Chapter 4.4.4 --- Effect of oxidized fatty acids on endothelium-dependent relaxation --- p.101 / Chapter 4.5 --- Discussion --- p.103 / Chapter CHAPTER 5 --- EFFECTS OF DIETARY OXIDIZED CHOLESTEROL ON BLOOD CHOLESTEROL LEVEL IN HAMSTERS / Chapter 5.1 --- Introduction --- p.107 / Chapter 5.2 --- Objectives --- p.111 / Chapter 5.3 --- Materials and Methods --- p.112 / Chapter 5.3.1 --- Preparation of Oxidized Cholesterol --- p.112 / Chapter 5.3.2 --- Diet preparation --- p.112 / Chapter 5.3.3 --- Animals --- p.113 / Chapter 5.3.4 --- Serum lipid and lipoprotein determinations --- p.116 / Chapter 5.3.5 --- GC analysis of cholesterol and cholesterol oxidation products on organs --- p.116 / Chapter 5.3.6 --- Extraction of neutral and acidic sterols from fecal samples --- p.117 / Chapter 5.3.6.1 --- Determination of neutral sterols --- p.117 / Chapter 5.3.6.2 --- Determination of acidic sterols --- p.117 / Chapter 5.3.6.3 --- GLC analysis of neutral and acidic sterols --- p.118 / Chapter 5.3.7 --- Organ bath experiment --- p.121 / Chapter 5.3.7.1 --- Preparation of aorta --- p.121 / Chapter 5.3.7.2 --- Aortic relaxation --- p.121 / Chapter 5.3.8 --- Analysis of the total area of atherosclerotic plaque on aorta --- p.122 / Chapter 5.3.9 --- Statistics --- p.122 / Chapter 5.4 --- Results --- p.123 / Chapter 5.4.1 --- GC of oxidized cholesterol --- p.123 / Chapter 5.4.2 --- Growth and food intake --- p.123 / Chapter 5.4.3 --- "Effect of non-oxidized and oxidized cholesterol on serum TC, TG and HDL-C" --- p.123 / Chapter 5.4.4 --- Effect of non-oxidized and oxidized cholesterol on non-HDL-C and ratio of non-HDL-C to HDL-C --- p.124 / Chapter 5.4.5 --- Effect ofnon-oxidized and oxidized cholesterol on concentration of hepatic cholesterol --- p.128 / Chapter 5.4.6 --- Effect of non-oxidized and oxidized cholesterol on concentration of cholesterol oxidation products accumulated in liver --- p.128 / Chapter 5.4.7 --- Effect of non-oxidized and oxidized cholesterol on concentration of brain and aortic cholesterol --- p.128 / Chapter 5.4.8 --- Effect of non-oxidized and oxidized cholesterol on fecal neutral and acidic sterols --- p.129 / Chapter 5.4.9 --- Effect of non-oxidized and oxidized cholesterol on aortic relaxation --- p.135 / Chapter 5.4.10 --- Effect of non-oxidzied and oxidized cholesterol on area of atherosclerotic plaque --- p.137 / Chapter 5.5 --- Discussion --- p.139 / Chapter CHAPTER 6 --- CONCLUSION --- p.143 / REFERENCES --- p.146

Yuen Yee Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 108-125). / Abstracts in English and Chinese. / TITLE PAGE --- p.1 / ACKNOWLEGDEMENTS --- p.2 / ABSTRACT --- p.3 / 摘要 --- p.5 / table of contents --- p.7 / list of figures and tables --- p.13 / CHAPTER 1 GENERAL INTRODUCTION --- p.16 / Chapter 1.1 --- role of PHYTOESTROGENS in soy and red WINE the PREVENTION OF CARDIOVASCULAR DISEASES (CVD) --- p.17 / Chapter 1.1.1 --- INTRoduction and Classification of Phytoestrogens --- p.17 / Chapter 1.1.2 --- estrogenic1ty of phytoestrogens and theIr abundancesin Plasma --- p.18 / Chapter 1.1.3 --- phytoestrogens as one of the active components In cvd Protection --- p.21 / Chapter 1.1.4 --- effects of Phytoestrogens on LDL Receptor and Apolipoprotein A-1 --- p.22 / Chapter 1.2 --- role of estrogen receptors (ers) in gene regulation --- p.24 / Chapter 1.2.1 --- "structure, Classification and tissue distribution of ERS" --- p.24 / Chapter 1.2.2 --- ligands for ERS --- p.25 / Chapter 1.2.3 --- mechaniSMS OF LIgands-ERS complex in GENE regulation --- p.27 / Chapter 1.2.4 --- ligand-independent ER activation --- p.28 / Chapter 1.3 --- aims and scopes of investigation --- p.29 / Chapter CHAPTER 2 --- MATERIALS AND METHODS --- p.30 / Chapter 2.1 --- chemicals and materials --- p.30 / Chapter 2.1.1 --- Chemicals --- p.30 / Chapter 2.1.2 --- Plasmids --- p.30 / Chapter 2.2 --- mammalian cell culture maintainence --- p.30 / Chapter 2.2.1 --- Maintenance of Cells --- p.31 / Chapter 2.2.2 --- Preparation of Cell Stock --- p.31 / Chapter 2.2.3 --- Cell Recovery from Liquid Nitrogen Stock --- p.31 / Chapter 2.3 --- manipulation of dna --- p.31 / Chapter 2.3.1 --- isolation of HEPG2 cells genonmic DNA --- p.31 / Chapter 2.3.2 --- separation and purification of dna from agarose gel --- p.31 / Chapter 2.3.3 --- Restriction digestionof DNA --- p.32 / Chapter 2.3.4 --- Ligation of DNA Fragments --- p.32 / Chapter 2.3.5 --- Transformation of --- p.32 / Chapter 2.3.6 --- Small Scale Plasmids Purification from DH5a --- p.32 / Chapter 2.4 --- construction of expression and reporter plasmids --- p.33 / Chapter 2.4.1 --- Construction of Estrogen Receptorα (Erα) Expression Vectors --- p.33 / Chapter 2.4.2 --- construction of reporter vectors of LDLR promoter and the Respective Mutants --- p.33 / Chapter 2.4.3 --- Construction of Reporter Vectors of APOAI Promoter and the Respective Mutants --- p.33 / Chapter 2.5 --- determination of promoter transcrtiption activities --- p.34 / Chapter 2.5.1 --- Transient Transfection of Cell with ERa Expression Vector and Promoter Reporter using Lipofectamine PLUS Reagent --- p.34 / Chapter 2.5.2 --- Dual Luciferase Assay --- p.34 / Chapter 2.6 --- semi-quantitative and quantitative rt-pcr assay --- p.34 / Chapter 2.6.1 --- Transient transfection of Cell with ERa Expression Vector Using Lipofectamine PLUS Reagent --- p.34 / Chapter 2.6.2 --- "Isolation of RNA using TRIzol® Reagent (Life Technology, USA)" --- p.35 / Chapter 2.6.3 --- Quantitation of RNA --- p.35 / Chapter 2.6.4 --- First Strand cDNA Synthesis --- p.35 / Chapter 2.6.5 --- Sem卜Quantitative PCR Reactions --- p.35 / Chapter 2.6.6 --- Quantitative PCR Reactions --- p.36 / Chapter 2.7 --- western blotting analysis --- p.36 / Chapter 2.8 --- statistical methods --- p.36 / Chapter CHAPTER 3 --- REGULATION BY PHYSIOLOGICAL LEVEL OF 17B-ESTRADIOL ON APOLIPOPROTEIN A-I AND LOW-DENSITY- LIPOPROTEIN RECEPTOR IN HEPG2 CELLS --- p.37 / Chapter 3.1 --- introduction --- p.37 / Chapter 3.2 --- results --- p.39 / Chapter 3.2.1 --- Determination of transient transfection functionality of estrogen receptors in hepg2 cells --- p.39 / Chapter 3.2.2 --- Effect of 17β-Estradiolon LDLR promoter transcription activity --- p.39 / Chapter 3.2.3 --- Effect of 17β-Estradiol on apoai promoter transcription activity --- p.40 / Chapter 3.2 --- discussion --- p.47 / Chapter CHAPTER 4 --- SOY ISOFLAVONES AND RESVERATROL DISPLAY DIFFERENT MECHANISM IN THE UP-REGULATION OF LOVV-DENSITY-LIPOPROTEIN RECEPTOR IN HEPG2 CELLS --- p.49 / Chapter 4.1 --- introduction --- p.49 / Chapter 4.2 --- results --- p.54 / Chapter 4.2.1 --- Association of ERα and isoflavones or resveratrol on LDLR promoter transcription activity --- p.54 / Chapter 4.2.2 --- Association of ERβ and isoflavones or resveratrol on LDLR promoter transcription activity --- p.54 / Chapter 4.2.3 --- "Role of MAP Kinase, PKA and PKC in isoflavones and resveratrol induced LDLR promoter transcription" --- p.55 / Chapter 4.2.4 --- Identification of promoter regions responsible for induction of LDLR transcription by isoflavones in the presence OF ERα --- p.55 / Chapter 4.2.5 --- Identification of promoter regions responsible for induction of LDLR TRANSCRIPTION BY resveratrol IN THE ABSENCE OF ERα --- p.56 / Chapter 4.3 --- DISCUSSION --- p.75 / Chapter CHAPTER 5 --- SOY ISOFLAVONES AND RESVERATROL UP-REGULATE APOLIPOPROTEIN A-I SIMILAR TO 17B-ESTRADIOL IN HEPG2 CELLS --- p.80 / Chapter 5.1 --- INTRODUCTION --- p.80 / Chapter 5.2 --- RESULTS --- p.84 / Chapter 5.2.1 --- Association of ERα phytoestrogens on APCAI gene expression --- p.84 / Chapter 5.2.2 --- Association of ERβ and isoflavones or resveratrol on APOAI promoter transcription activity --- p.85 / Chapter 5.2.3 --- "Role of MAP Kinase, PKA and PKC in isoflavones and resveratrol in APOAI promoter transcription in the presence of ERα" --- p.85 / Chapter 5.2.4 --- Identification of promoter regions responsible for induction of APOAI transcription by isoflavones and resveratrol in the presence of ERα --- p.85 / Chapter 5.3 --- DISCUSSION --- p.100 / Chapter CHAPTER 6 --- GENERAL DISCUSSION --- p.103 / Chapter CHAPTER 7 --- SUMMARY --- p.106 / BIBLIOGRAPHY --- p.108 / APPENDIX 1 ABBREVIATIONS --- p.126 / APPENDIX 2 MATERIALS AND METHODS --- p.129 / APPENDIX 3 PRIMER LISTS --- p.145 / APPENDIX 4 REAGENTS AND BUFFERS --- p.147