Stress på akutmottagningen ur ett sjuksköterskeperspektiv : En litteraturstudie

Sjuksköterskor som arbetar på akutmottagningar utsätts regelbundet för stress. Det medför psykiska och fysiska besvär för sjuksköterskor och försämrad omvårdnad för patienten. Studien avser att utifrån vetenskaplig litteratur sammanställa de faktorer som leder till stress för sjuksköterskor som arbetar på akutmottagningar och hur vården påverkas av stressade sjuksköteskor. Syfte Syftet med litteraturstudien var att beskriva vilka faktorer på akutmottagningen som upplevdes bidra till stress för sjuksköterskor som arbetar på en akutmottagning och hur stressen påverkar sjuksköterskors möjligheter att erbjuda en god vård för patienter på akutmottagningen. Metod Studien har genomförts som en litteraturstudie. I studien användes 15 artiklar som bestod av både kvalitativ och kvantitativ ansats. Materialet hämtades i databaserna CINAHL och PubMed. Resultat Resultatet visar att det finns flera olika faktorer som bidrar till stress för sjuksköterskor på akutmottagningen. Stressande faktorer visade sig utifrån studierna i resultatet vara; hög arbetsbelastning och låg bemanning, avsaknad av tid för reflektion för sjuksköterskan, att vårda barn i stressade situationer, hot och våld på akutmottagningen, kommunikation samt smärta och lidande. Hur vården påverkas av sjuksköterskors stress på akutmottagningen var utifrån studierna att patientsäkerheten blev försämrad och att vårdrelationen påverkades. Slutsats Författarna drar slutsatsen att stress påverkar sjuksköteskors arbetsuppgifter på akutmottagningen. Patienters möjlighet till patientsäker och god vård på akutmottagningen påverkas negativt av stressade sjuksköterskor. För att komma till rätta med sjuksköterskebristen på akutmottagningar så är det av betydelse för sjukhusledningen att arbeta preventivt mot stressade sjuksköterskor.

Mellanchefers upplevelser av psykosocial arbetsmiljö inom distributions- och logistikverksamhet – en pendling mellan hög aktivitet och låg stress?

Forskarnas genuina intresse för den psykosociala arbetsmiljön med koppling mellanchefer gav upphov till att dyka djupare inom området och belysa centrala delar i form av krav, kontroll och socialt stöd. Framåtskridandet går mot en ökad medvetenhet kring den psykosociala arbetsmiljön, då ohälsan i arbetslivet ökar och Arbetsmiljöverkets nya föreskrift om organisatorisk och social arbetsmiljö är i fokus. I linje med en ökad medvetenhet som sker kring den psykosociala arbetsmiljön vill vi rikta ett särskilt fokus till mellanchefer som bör ha en förmåga att hantera krav både uppifrån och ned. Studien har främst utgått från Robert Karaseks och Töres Theorells Krav – kontroll – stödmodellen. Syftet är att undersöka mellanchefers upplevelse med fokus på den psykosociala arbetsmiljön i ett privat företag inom distributions- och logistikverksamhet. Metoden har bestått av en kvalitativ metod i form av en fallstudie där semistrukturerade intervjuer ligger som grund med åtta respondenter ifrån distributionscentret. Resultatet uppvisar att mellancheferna har en hög grad av inflytande, upplevelsen av arbetskrav varierar men i koppling till befattningen är kraven rimliga. Det sociala stödet upplevs som bra på arbetsplatsen och anses av funktionscheferna som en viktig och central del i arbetet. Slutsatser som har uppnåtts är att funktionscheferna har rimliga krav och upplever en bra nivå av kontroll i arbetet, men att ha en alltför hög kontroll i arbetet kan leda till negativ stress. En balans i pendlingen mellan aktiva arbeten och lågstressarbeten anses vara en fördel för att bevara en god psykosocial arbetsmiljö. Detta för att motverka de negativa effekterna som kan uppstå av att befinna sig inom varje komponent för länge. I studien har det påvisats att företaget anses ha en god psykosocial arbetsmiljö och därmed kan ses som ett gott exempel i arbetslivet.

Stress e Emergência Médica: níveis e factores de stress em profissionais de emergência pré–hospitalar

O stress é a doença da actualidade, devido à exigência e à pressão emocional que o meio pode exercer sobre todas as pessoas, quer no seu ambiente pessoal quer no ambiente profissional. O termo stress serve cada vez mais como justificação ou forma de expressão de irritações, mal-estar físico e mental, cansaço, ansiedade e depressões. Todavia torna-se pertinente percebermos a evolução do stress enquanto conceito e enquanto doença. Neste trabalho contextualizamos o stress no âmbito da Emergência Pré – Hospitalar, explorando-o, avaliando-o e analisando-o, de modo a podermos perceber os níveis de stress e de que forma os Profissionais de Emergência a ele estão sujeitos. Considerando a base teórica deste estudo definimos, como objectivo geral do trabalho, a avaliação de níveis e factores de stress percepcionados pelos profissionais de emergência médica e como objectivos específicos do estudo a descrever e caracterizar, a nível da região centro, os indivíduos que desempenham funções na emergência préhospitalar, verificar a percepção dos mesmos no que respeita ao stress na sua vida profissional, conhecer como percepcionam os níveis de stress em situações profissionais de emergência e identificar a sua percepção no que concerne aos níveis de stress diário no seu quotidiano. Com estes objectivos, utilizamos uma amostra de 184 profissionais de Emergência Médica divididos por quatro profissões [Médicos, Enfermeiros, Técnicos de Ambulância de Emergência (TAE) e Operadores de Central de Emergência Médica(OPCEM)], com idades compreendidas entre os 20 e os 56 anos. Realizámos ainda um estudo descritivo explorando os questionários de stress no INEM (Instituto Nacional de Emergência Médica) e o Questionário de Vulnerabilidade do Stress com variáveis do estudo demográfico. Podemos concluir que o stress está presente nas actividades de emergência. A sua presença relaciona-se, por um lado, com uma maior ou menor discriminação dos factores stressantes e, por outro, numa maior ou menor centração no sujeito, nomeadamente, um maior perfeccionismo e intolerância à frustração que se apresentam como distressantes para a actividade profissional de emergência. Os aspectos estudados permitem-nos clarificar o sentido e a utilidade do conceito, a sua operacionalidade e a sua importância nos profissionais de emergência. / Stress is the disease of our time, due to the requirement and emotional pressure that the media can have on all people, both in their personal environment and in the professional environment. The word stress increasingly serves as a justification or form of expression of irritation, physical discomfort and mental fatigue, anxiety and depression. However it is pertinent to realize the evolution of stress as a concept and as a disease. In this work, we contextualize under the stress of the Pre - Hospital Emergency, exploring it, assessing it and analyzing it, so you can see the stress levels and how the Emergency Professionals are subject to it. Whereas the theoretical basis of this study as a strategic objective of the work, the assessment of levels and stress factors perceived by medical emergency professionals and specific objectives of the study description and characterization, the level of the center, individuals who perform functions in pre-hospital emergency, check their perception with regard to the stress in your life, know how they experience the stress levels of professionals in emergency situations and identify the perceptions of individuals regarding the levels of daily stress in their daily lives. For this we used a sample of 184 professionals of Medical Emergency divided by four professions [(Doctors, Nurses, Technicians Ambulance Emergency (TAE), Operators of Emergency Medical Center (OPCEM)], aged 20 to 56 years. We conducted a descriptive study also exploring the questionnaires of stress in INEM(National Institute of Medical Emergency) and Vulnerability Questionnaire Stress with variables of the study population. We can conclude that stress is present in emergency activities. Its presence is related to, first, with more or less stressful factors of discrimination and, secondly, a greater or lesser concentration on the subject, in particular, greater perfectionism and intolerance to frustration that stand as unstressed for the activity of emergency professionals. The areas studied will clarify the meaning and usefulness of the concept, its operation and its importance in day-to-day occupation of emergency.

Étude de la nucléophosmine NPM dans la réponse de l’endothélium à un stress oxydant majeur

Le compartiment microvasculaire est une cible importante du stress oxydant qui est un facteur majeur de la dysfonction endothéliale, notamment au cours d’exposition aux rayonnements ionisants. L’altération de l’endothélium induite par le stress oxydant est impliquée dans la toxicité radio-induite des tissus sains. Limiter les dysfonctions endothéliales est donc un enjeu important des traitements radiothérapeutiques actuels. Cet objectif nécessite une meilleure caractérisation de la signalisation du stress oxydant dans les cellules endothéliales. La voie p38 MAPK est incontournable dans la réponse au stress oxydant mais reste encore insuffisamment caractérisée. Par une approche protéomique, nous avons identifié la nucléophosmine (NPM) comme nouveau partenaire de p38 dans le cytoplasme des cellules endothéliales. La phosphatase PP2a est aussi associée à ce complexe NPM/p38. Nos travaux montrent que le stress oxydant (H2O2, 500μM) régule la déphosphorylation de NPM via PP2a, entraine sa dissociation rapide du complexe et favorise sa translocation vers le noyau. De plus, nous montrons que la présence de NPM déphosphorylée au noyau altère la réponse des cellules aux dommages à l’ADN induits par le stress oxydant. Le céramide sphingolipide membranaire est également un facteur important des voies de stress, particulièrement dans les cellules endothéliales. Notre étude aborde donc l’implication de ce sphingolipide dans la régulation de la voie NPM/p38. Une meilleure caractérisation de la voie p38 et de ses acteurs permettra d’identifier de potentielles cibles afin de limiter les dysfonctions endothéliales et leurs conséquences délétères sur les tissus environnants.

Ansiedade, Stress, Depressão e Lapsos de Memória

Apesar de todos nós nos esquecermos, é comum atribuir-se os lapsos de memória às pessoas com idades avançadas. A evidência científica tem, no entanto, demonstrado que o esquecimento advém de uma multiplicidade de factores, como por exemplo, o excesso de trabalho, falta de descanso, entre outros. Neste estudo pretende-se saber se existe associação entre a tríade conceptual ansiedade, stress e depressão e os lapsos de memória, numa população em idade activa e com habilitações académicas de nível superior. A amostra é constituída por 68 professores que exercem a sua actividade profissional na Escola E.B. 2,3 de Cantanhede. A recolha dos dados foi efectuada recorrendo a: um questionário elaborado por nós, constituído por questões abertas e fechadas, uma Escala de Ansiedade, Depressão e Stress (EADS-21) e um Questionário de lapsos de memória (QLM). As análises estatísticas dos questionários foram efectuadas recorrendo ao programa informático SPSS (versão 15). As análises tiveram com objectivo final a testagem das hipóteses e tomaram em consideração a natureza métrica das variáveis. / In spite of all of we forget ourselves, it is common the lapses of memory are attributed to the persons with advanced ages. The scientific evidence has, however, when that the oblivion results from a multiplicity of factors was demonstrated, I eat for example, the excess of work, rest lack, between others. In this study one intends to know if there is association between the conceptual triad anxiety, stress and depression and the lapses of memory, in a population in active age and with academic competences of superior level. The sample is constituted by 68 teachers who practice his professional activity in the School E.B. 2,3 of Cantanhede. The gathering of the data was effectuated resorting to: a questionnaire prepared by us, constituted by questions open and shut, a Scale of Anxiety, Depression and Stress (EADS-21) and a Questionnaire of lapses of memory (QLM). The statistical analyses of the questionnaires were effectuated when there is resorting to the program informatics SPSS (version 15). The analyses had with final objective the testate of the hypotheses and took in consideration the metric nature of the variables.

Relação entre Vulnerabilidade ao Stress e Estratégias de Coping: estudo de caso numa empresa de venda a retalho da Região Centro do País

As situações indutoras de stress são uma constante imutável no dia-a-dia do ser humano e quando esta perturbação não é gerida de forma adequada, acarreta graves prejuízos na saúde dos indivíduos refletindo-se em diversas áreas das suas vidas nomeadamente no trabalho. O presente estudo tem como finalidade identificar a relação entre o stress e as estratégias de coping e perceber se os indivíduos com vulnerabilidade ao stress diferem dos indivíduos sem stress no que concerne às estratégias de coping utilizadas. A vulnerabilidade ao stress foi medida pela escala 23QVS, enquanto as estratégias de coping foram avaliadas pelo Inventário de Resolução de Problemas (IRP), tendo sido, ainda, utilizado um questionário sociodemográfico. A amostra foi composta por 62 trabalhadores de uma empresa de venda a retalho com idades compreendidas entre os 20 e os 44 anos (M=32,02 DP=5,770). Os resultados obtidos revelaram que a vulnerabilidade ao stress se correlaciona de forma negativa e altamente significativa com as estratégias de coping e que indivíduos com e sem vulnerabilidade ao stress não diferem quanto ao uso destas estratégias. / The stress-induction situations are a constant unchanging in human being life, and if this disturbance is not managed adequately can be harmful to the health of individuals and reflected in many areas of their lives including their work. The present study aims to analyze the relationship between stress and coping strategies, and understand if individuals with stress vulnerability differs from individuals without stress in respect to the use of coping strategies. Stress vulnerability was measured by the 23QVS scale and coping strategies by the Inventário de Resolução de Problemas – IRP (Inventory of Problem Solving), and we also used a sociodemographic questionnaire. The sample consisted of 62 workers of a retailing company with ages between 20 and 40 years old (M = 32,02; DP = 5,770). Our research studies reveal that stress vulnerability correlates negatively and highly with coping strategies, and individuals with and without stress vulnerability not differ in the use of these strategies.

Influence of grinding operations on surface integrity and chloride induced stress corrosion cracking of stainless steels

Stainless steels were developed in the early 20th century and are used where both the mechanical properties of steels and corrosion resistance are required. There is continuous research to allow stainless steel components to be produced in a more economical way and be used in more harsh environments. A necessary component in this effort is to correlate the service performance with the production processes. The central theme of this thesis is the mechanical grinding process.  This is commonly used for producing stainless steel components, and results in varied surface properties that will strongly affect their service life. The influence of grinding parameters including abrasive grit size, machine power and grinding lubricant were studied for 304L austenitic stainless steel (Paper II) and 2304 duplex stainless steel (Paper I). Surface integrity was proved to vary significantly with different grinding parameters. Abrasive grit size was found to have the largest influence. Surface defects (deep grooves, smearing, adhesive/cold welding chips and indentations), a highly deformed surface layer up to a few microns in thickness and the generation of high level tensile residual stresses in the surface layer along the grinding direction were observed as the main types of damage when grinding stainless steels. A large degree of residual stress anisotropy is interpreted as being due to mechanical effects dominating over thermal effects. The effect of grinding on stress corrosion cracking behaviour of 304L austenitic stainless steel in a chloride environment was also investigated (Paper III). Depending on the surface conditions, the actual loading by four-point bend was found to deviate from the calculated value using the formula according to ASTM G39 by different amounts. Grinding-induced surface tensile residual stress was suggested as the main factor to cause micro-cracks initiation on the ground surfaces. Grinding along the loading direction was proved to increase the susceptibility to chloride-induced SCC, while grinding perpendicular to the loading direction improved SCC resistance. The knowledge obtained from this work can provide a reference for choosing appropriate grinding parameters when fabricating stainless steel components; and can also be used to help understanding the failure mechanism of ground stainless steel components during service.

Psychology and Social Work: Applied Perspectives

Successful social work practice is underpinned by knowledge, theories and research findings from a range of related disciplines, key amongst which is psychology. This timely book offers a grounded and engaging guide to psychology s vital role at the heart of contemporary social work practice. The book skilfully addresses some of the central theoretical developments in psychology from an applied perspective, and explains how these make essential contributions to the methods and theory base of social work in ways that foster critical evaluation and promote best practice. Written by two authors with extensive backgrounds in psychology and social work respectively as well as a deep understanding of the intersections of the two this book delivers a unique synthesis of perspectives and approaches, focusing on their application to the lives of individuals and families. Each chapter contains reflective points and case studies based on contemporary practice realities which are related to the Professional Capabilities Framework for Social Workers and also to the Health and Care Professions Council s Standards of Proficiency. Times have never been more challenging for social work and this book will be an invaluable source of professional support within the ever-more complex psychological worlds where social work takes place. Table of Contents 1. Introduction: The place of psychological knowledge and research in social work training and practice 2. Signposts from Developmental Psychology on Human Development over the Life Course 3. Perspectives from Clinical and Counselling Psychology on Mental Health and Illness 4. Perspectives from Social and Community Psychology: Understanding values, attitudes, diversity and community change 5. Health Psychology: Understanding health, illness, stress and addiction 6. Organizational Psychology: Understanding the individual and the organization in the social work structure 7. Forensic Psychology: Understanding criminal behaviour and working with victims of crime 8. Conclusion References Index

Vivre avec un syndrome de stress post-traumatique : l'expérience et l'impact du diagnostic pour des militaires français

Ce mémoire de maitrise porte sur deux axes principaux : la mise en diagnostic et les enjeux que cela représente pour l’individu ainsi que la question du syndrome de stress post-traumatique (SSPT) dans une population particulière, celle des militaires français. À travers une étude de différents concepts anthropologiques tels que la sous-culture militaire, l’anthropologie du corps, de la mémoire et du discours, le travail de terrain a permis de mettre de l’avant l’expérience et l’impact du diagnostic du syndrome de stress post-traumatique. Les différentes étapes de la mise en diagnostic sont présentées afin de découvrir comment est vécue l’officialisation de ce trouble. Il est alors expliqué le paradoxe propre à ce diagnostic qui est posé, peu importe le type de choc traumatique à l’origine du SSPT. Cela permet de comprendre pourquoi le diagnostic du syndrome de stress post-traumatique reste un véritable enjeu lorsqu’il est question de la population militaire. Bien que de plus en plus de recherches existent sur le sujet au Canada ou aux États-Unis, la question en France reste encore en développement. C’est pourquoi cette recherche permet de découvrir la perception du trouble pour l’individu atteint et ses proches, la prévention et la prise en charge du stress post-traumatique à travers le diagnostic proposé actuellement.

Information and communication technology demands at work : the association with job strain, effort-reward imbalance and self-rated health in different socio-economic strata

PURPOSE: The use of information and communication technology (ICT) is common in modern working life. ICT demands may give rise to experience of work-related stress. Knowledge about ICT demands in relation to other types of work-related stress and to self-rated health is limited. Consequently, the aim of this study was to examine the association between ICT demands and two types of work-related stress [job strain and effort-reward imbalance (ERI)] and to evaluate the association between these work-related stress measures and self-rated health, in general and in different SES strata. METHODS: This study is based on cross-sectional data from the Swedish Longitudinal Occupational Survey of Health collected in 2014, from 14,873 gainfully employed people. ICT demands, job strain, ERI and self-rated health were analysed as the main measures. Sex, age, SES, lifestyle factors and BMI were used as covariates. RESULTS: ICT demands correlated significantly with the dimensions of the job strain and ERI models, especially with the demands (r = 0.42; p < 0.01) and effort (r = 0.51; p < 0.01) dimensions. ICT demands were associated with suboptimal self-rated health, also after adjustment for age, sex, SES, lifestyle and BMI (OR 1.49 [95 % CI 1.36-1.63]), but job strain (OR 1.93 [95 % CI 1.74-2.14) and ERI (OR 2.15 [95 % CI 1.95-2.35]) showed somewhat stronger associations with suboptimal self-rated health. CONCLUSION: ICT demands are common among people with intermediate and high SES and associated with job strain, ERI and suboptimal self-rated health. ICT demands should thus be acknowledged as a potential stressor of work-related stress in modern working life.

Topology Optimization of continuum structures with epsilon-relaxed stress constraints

Topology optimization of linear elastic continuum structures is a challenging problem when considering local stress constraints. The reasons are the singular behavior of the constraint with the density design variables, combined with the large number of constraints even for small finite element meshes. This work presents an alternative formulation for the s-relaxation technique, which provides an workaround for the singularity of the stress constraint. It also presents a new global stress constraint formulation. Derivation of the sensitivities for the constraint by the adjoint method is shown. Results for single and multiple load cases show the potential of the new formulation.

Transcriptomic comparison between two Vitis vinifera L. varieties (Trincadeira and Touriga Nacional) in abiotic stress conditions

Predicted climate changes announce an increase of extreme environmental conditions including drought and excessive heat and light in classical viticultural regions. Thus, understanding how grapevine responds to these conditions and how different genotypes can adapt, is crucial for informed decisions on accurate viticultural actions. Global transcriptome analyses are useful for this purpose as the response to these abiotic stresses involves the interplay of complex and diverse cascades of physiological, cellular and molecular events. The main goal of the present work was to evaluate the response to diverse imposed abiotic stresses at the transcriptome level and to compare the response of two grapevine varieties with contrasting physiological trends, Trincadeira (TR) and Touriga Nacional (TN).

STRESS AND INTERNATIONAL ENTREPRENEURHSIP: The dark side of international entrepreneurship

Entrepreneurship attracts people with high job satisfaction and financial independence. Unfortunately, being deceived by this image, people do not pay attention to side effects of entrepreneurship. This ignorance usually turns into devastating results for entrepreneur’s health and venture performance. Therefore, it is required to seek ways to avoid these situations. The interest of the study lies in understanding of stress influence on international entrepreneurs by considering stress as a negative side effect of international entrepreneurship. To cover the concept of entrepreneurial stress completely, the study was divided into three section presented by following research questions: 1. What are the antecedents of entrepreneurial stress? 2. What are the consequences of entrepreneurial stress? 3. What coping strategies are applied to address entrepreneurial stress? Systematic literature review has been chosen as scientific approach to answer above questions due to the reason that it enables to minimise inconsistencies of both concepts of international entrepreneurship and stress. This method has afforded an opportunity to distinguish such stress causes as role conflict, overload, and ambiguity. Additionally, the study has covered the notion of stress moderators. The author argues that entrepreneurial traits, venture environment, and social support can have influence on degree of stress perception. Further, it has been proven that unaddressed stress could lead to reduction of entrepreneur’s psychological and physiological health. It should be taken into consideration that degree of both job satisfaction and performance would depend on the level of perceived stress. The last part of study emphasises the coping strategies. The author argues that it is important for an international entrepreneur to comprehend his or her and others’ emotions in order to overcome negative consequences of stress. In addition, the author suggests that an international entrepreneur needs to practise job sharing to reduce the amount of work to be completed. Moreover, it is believed that job sharing can help to overcome work-family conflict that prevails among entrepreneurs. The author anticipates that results of study can be beneficial for entrepreneurs who aim to achieve great results.

In situ characterization of sediment oxygen demand across the spectrum of non-resuspension to full resuspension with varying bed shear stress

Sediment oxygen demand (SOD) can be a significant oxygen sink in various types of water bodies, particularly slow-moving waters with substantial organic sediment accumulation. In most settings where SOD is a concern, the prevailing hydraulic conditions are such that the impact of sediment resuspension on SOD is not considered. However, in the case of Bubbly Creek in Chicago, Illinois, the prevailing slack water conditions are interrupted by infrequent intervals of very high flow rates associated with pumped combined sewer overflow (CSO) during intense hydrologic events. These events can cause resuspension of the highly organic, nutrient-rich bottom sediments, resulting in precipitous drawdown of dissolved oxygen (DO) in the water column. While many past studies have addressed the dependence of SOD on near-bed velocity and bed shear stress prior to the point of sediment resuspension, there has been limited research that has attempted to characterize the complex and dynamic phenomenon of resuspended-sediment oxygen demand. To address this issue, a new in situ experimental apparatus referred to as the U of I Hydrodynamic SOD Sampler was designed to achieve a broad range of velocities and associated bed shear stresses. This allowed SOD to be analyzed across the spectrum of no sediment resuspension associated with low velocity/ bed shear stress through full sediment resuspension associated with high velocity / bed shear stress. The current study split SOD into two separate components: (1) SODNR is the sediment oxygen demand associated with non-resuspension conditions and is a surface sink calculated using traditional methods to yield a value with units (g/m2/day); and (2) SODR is the oxygen demand associated with resuspension conditions, which is a volumetric sink most accurately characterized using non-traditional methods and units that reflect suspension in the water column (mg/L/day). In the case of resuspension, the suspended sediment concentration was analyzed as a function of bed shear stress, and a formulation was developed to characterize SODR as a function of suspended sediment concentration in a form similar to first-order biochemical oxygen demand (BOD) kinetics with Monod DO term. The results obtained are intended to be implemented into a numerical model containing hydrodynamic, sediment transport, and water quality components to yield oxygen demand varying in both space and time for specific flow events. Such implementation will allow evaluation of proposed Bubbly Creek water quality improvement alternatives which take into account the impact of SOD under various flow conditions. Although the findings were based on experiments specific to the conditions in Bubbly Creek, the techniques and formulations developed in this study should be applicable to similar sites.

Oxidative stress and its haemodynamic consequences in chronic kidney disease

Chronic kidney disease (CKD) is associated with increased cardiovascular risk in comparison with the general population. This can be observed even in the early stages of CKD, and rises in proportion to the degree of renal impairment. Not only is cardiovascular disease (CVD) more prevalent in CKD, but its nature differs too, with an excess of morbidity and mortality associated with congestive cardiac failure, arrhythmia and sudden death, as well as the accelerated atherosclerosis which is also observed. Conventional cardiovascular risk factors such as hypertension, dyslipidaemia, obesity, glycaemia and smoking, are highly prevalent amongst patients with CKD, although in many of these examples the interaction between risk factor and disease differs from that which exists in normal renal function. Nevertheless, the extent of CVD cannot be fully explained by these conventional risk factors, and non-conventional factors specific to CKD are now recognised to contribute to the burden of CVD. Oxidative stress is a state characterised by excessive production of reactive oxygen species (ROS) and other radical species, a reduction in the capacity of antioxidant systems, and disturbance in normal redox homeostasis with depletion of protective vascular signalling molecules such as nitric oxide (NO). This results in oxidative damage to macromolecules such as lipids, proteins and DNA which can alter their functionality. Moreover, many enzymes are sensitive to redox regulation such that oxidative modification to cysteine thiol groups results in activation of signalling cascades which result in adverse cardiovascular effects such as vascular and endothelial dysfunction. Endothelial dysfunction and oxidative stress are present in association with many conventional cardiovascular risk factors, and can be observed even prior to the development of overt, clinical, vascular pathology, suggesting that these phenomena represent the earliest stages of CVD. In the presence of CKD, there is increased ROS production due to upregulated NADPH oxidase (NOX), increase in a circulating asymmetric dimethylarginine (ADMA), uncoupling of endothelial nitric oxide synthase (eNOS) as well as other mechanisms. There is also depletion in exogenous antioxidants such as ascorbic acid and tocopherol, and a reduction in activity of endogenous antioxidant systems regulated by the master gene regulator Nrf-2. In previous studies, circulating markers of oxidative stress have been shown to be increased in CKD, together with a reduction in endothelial function in a stepwise fashion relating to the severity of renal impairment. Not only is CVD linked to oxidative stress, but the progression of CKD itself is also in part dependent on redox sensitive mechanisms. For example, administration of the ROS scavenger tempol attenuates renal injury and reduces renal fibrosis seen on biopsy in a mouse model of CKD, whilst conversely, supplementation with the NOS inhibitor L-NAME causes proteinuria and renal impairment. Previous human studies examining the effect of antioxidant administration on vascular and renal function have been conflicting however. The work contained in this thesis therefore examines the effect of antioxidant administration on vascular and endothelial function in CKD. Firstly, 30 patients with CKD stages 3 – 5, and 20 matched hypertensive controls were recruited. Participants with CKD had lower ascorbic acid, higher TAP and ADMA, together with higher augmentation index and pulse wave velocity. There was no difference in baseline flow mediated dilatation (FMD) between groups. Intravenous ascorbic acid increased TAP and O2-, and reduced central BP and augmentation index in both groups, and lowered ADMA in the CKD group only. No effect on FMD was observed. The effects of ascorbic acid on kidney function was then investigated, however this was hindered by the inherent drawbacks of existing methods of non-invasively measuring kidney function. Arterial spin labelling MRI is an emerging imaging technique which allows measurement of renal perfusion without administration of an exogenous contrast agent. The technique relies upon application of an inversion pulse to blood within the vasculature proximal to the kidneys, which magnetically labels protons allowing measurement upon transit to the kidney. At the outset of this project local experience using ASL MRI was limited and there ensued a prolonged pre-clinical phase of testing with the aim of optimising imaging strategy. A study was then designed to investigate the repeatability of ASL MRI in a group of 12 healthy volunteers with normal renal function. The measured T1 longitudinal relaxation times and ASL MRI perfusion values were in keeping with those found in the literature; T1 time was 1376 ms in the cortex and 1491 ms in the whole kidney ROI, whilst perfusion was 321 mL/min/100g in the cortex, and 228 mL/min/100g in the whole kidney ROI. There was good reproducibility demonstrated on Bland Altman analysis, with a CVws was 9.2% for cortical perfusion and 7.1% for whole kidney perfusion. Subsequently, in a study of 17 patients with CKD and 24 healthy volunteers, the effects of ascorbic acid on renal perfusion was investigated. Although no change in renal perfusion was found following ascorbic acid, it was found that ASL MRI demonstrated significant differences between those with normal renal function and participants with CKD stages 3 – 5, with increased cortical and whole kidney T1, and reduced cortical and whole kidney perfusion. Interestingly, absolute perfusion showed a weak but significant correlation with progression of kidney disease over the preceding year. Ascorbic acid was therefore shown to have a significant effect on vascular biology both in CKD and in those with normal renal function, and to reduce ADMA only in patients with CKD. ASL MRI has shown promise as a non-invasive investigation of renal function and as a biomarker to identify individuals at high risk of progressive renal impairment.