Dissertations / Theses on the topic 'Kidney disease'

We read with interest the Lancet Series on Global Kidney Disease. Valerie Luyckx and colleagues describe the economics and medical management of chronic kidney disease in sub-Saharan Africa.1 We note clear similarities with patients in Peru. Indeed, in Peru, the Ministry of Health (MINSA)—which covers 70% of the population—does not have a comprehensive programme for the management of patients with chronic kidney disease, including renal replacement therapies. However, the Social Security System (Essalud)—which covers 20% of the population—has a chronic kidney disease programme.
Revisión por pares

Ischemia and reperfusion are natural steps during kidney transplantation, and IRI is considered one of the most important nonspecific factors affecting allograft dysfunction. Transplanted organs experience several episodes of ischemia, in which cold ischemia occurs during allograft storage in preservation solutions. Even though cold ischemia has been studied extensively, all of the studies have been carried out in vitro and ex vivo models. There is no in vivo model available to examine renal IRI induced solely by cold ischemia. In the present study, we developed an in vivo mouse model to study renal IRI induced exclusively by cold ischemia through clamping the renal pedicle for 1 to 5 hours. During the ischemic phase, blood was flushed from the kidney with cold saline through a small opening on the renal vein. The kidney was kept cold in a kidney cup with circulating cooled saline, while the body temperature was maintained at 37℃ during the experiment. The level of kidney injury was evaluated by plasma creatinine, KIM-1, NAGL, GFR, and histology. Plasma creatinine was significantly increased from 0.15±0.04 mg/dl in the sham group to 1.14±0.21 and 2.65±0.14 mg/dl in 4 and 5-hours ischemia groups at 24 hours after cold IRI. The plasma creatinine in mice with ischemic time <3 hours demonstrated no significant increase compared with sham mice. Changes in KIM-1, NAGL, GFR and histology were similar to plasma creatinine. 65 In summary, we developed and characterized a novel in vivo IRI-induced AKI mouse model exclusively produced by cold ischemia.

Thesis (M.B.A.)--University of Nevada, Reno, 2005.
"May, 2005." Includes bibliographical references (leaves 92-97). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm.

Les microARNs sont reconnus comme des régulateurs essentiels de l'expression des protéines. Des anomalies dans leur fonction sont associées au développement de nombreuses pathologies.tiel des microARNs en tant que biomarqueurs ou cibles thérapeutiques dans une grande variété de pathologies. Dans le cadre de cette thèse, nous avons étudié :1) L'association des microARNs urinaires avec l'évolution de la maladie rénale chronique (MRC) chez l'adulte. La prévalence de la MRC est actuellement estimée à 5-10% de la population et est en constante augmentation. La détection précoce et l'identification de patients ayant une MRC progressant rapidement vers l'insuffisance rénale sont la clé pour une meilleure prise en charge de ces patients. Actuellement les outils non-invasifs comme l'albuminurie ou l'estimation du débit de filtration glomérulaire manquent de précision. Dans notre travail, nous avons tenté d'identifier les modifications urinaires des microRNAs afin d'identifier de nouveaux biomarqueurs non-invasifs associés à la progression de la MRC. Nous avons analysé les modifications des microARNs urinaires par séquençage à haut débit dans des échantillons d'urine de 70 patients atteints de MRC et corrélé leurs profils d'expression à la progression de la maladie. Cela a amené à l'identification de 25 microARNs urinaires (pvalue ajustée <0.05) potentiellement associés à la progression de la MRC. Parmi ceux-là, quatre microARNs (hsa-miR-34c-5p, hsa-miR-410-3p, hsa-miR-301b-3p, and hsa-miR-145-5p) ont été sélectionnés pour être validés dans une cohorte indépendante de 52 patients atteints de MRC. L'augmentation de l'abondance urinaire de hsa-miR-145-5p a été confirmée comme étant associée à la progression de la MRC. Des analyses in vitro de l'effet de l'inhibition de hsa-miR-145-5p dans les cellules rénales ont mis en évidence que ce microARN semblait être impliqué dans le processus de nécrose. En conclusion, cette étude nous a permis d'identifier hsa-miR-145-5p comme Ainsi, de nombreuses études s'intéressent au potenmarqueur potentiel de la progression de la MRC. 2) La présence de microARNs urinaires associés à la néphropathie obstructive, une maladie fréquemment rencontrée chez les enfants qui peut conduire, dans les cas graves, à l'insuffisance rénale précoce. Dans cette étude, nous avons utilisé la biologie des systèmes et avons combiné des données microARN et ARNm de néphropathie obstructive humaine et animale pour obtenir des informations sur les mécanismes possibles impliqués dans cette maladie. En particulier, nous avons étudié simultanément le miRNome urinaire de nourrissons présentant une obstruction de la jonction pyélo-urétérale et le miRNome et le transcriptome tissulaire rénal chez la souris dans le modèle animal d'obstruction urétérale unilatéral (OUU) partiel et néonatal. Plusieurs centaines de microARNs et d'ARNms étant modifiés, la combinaison des microARNs des deux espèces avec les ARNms cibles associés a permis de sélectionner les 5 microARNs et 35 ARNms les plus fortement associés à la néphropathie obstructive. Une validation in vitro et in vivo a mis en avant que let-7a-5p et miR-29-3p ainsi que deux nouvelles cibles potentielles, l'E3 ubiquitin-protein ligase (DTX4) et neuron navigator 1 (NAV1) étaient dérégulées au cours de cette pathologie. Cette étude est la première à corréler le modèle animal d'OUU partiel et néonatal avec l'obstruction pyélo-urétérale chez l'Homme dans une analyse intégrée de biologie des systèmes. Nos résultats ont révélé let-7a et miR-29b en tant que molécules potentiellement impliquées dans le développement de la fibrose dans la néphropathie obstructive via le contrôle de DTX4 chez l'homme et la souris, ce qui n'aurait pas été identifiable autrement
MicroRNAs are now recognized as key players in the regulation of proteins and any abnormality in their function is a cause for pathway instability, leading to pathological conditions. Numerous reports from a variety of pathologies provide new data about microRNAs function, their targets and their potential as biomarkers and possible ways to control microRNAs' expression for potential therapeutic purpose. A number of reports also connect microRNAs with pathological conditions in the kidney and point to the use of microRNAs as biomarkers for diagnosis and prognosis of kidney disease in blood, serum, tissue and urine samples. In this thesis, we researched:1) A possible role of the microRNAs in the progression of adult chronic kidney disease (CKD), a disease representing a global burden with the tendency to rise worldwide. Progression of CKD is still very hard to detect non-invasively with the currently used clinical tools (eGFR and albuminuria). In our work we studied alterations of the level of the microRNAs in human urine samples of patients with fast or slow progression of CKD, in order to identify new potential biomarkers for non-invasive progression of CKD. Using Next Generation Sequencing, we analyzed urinary microRNA modifications in urine samples of 70 patients with established CKD and correlated their expression profiles to disease progression. This lead to the identification of 25 urinary microRNAs significantly associated to CKD progression (adjusted pvalue<0.05). Among those, four microRNAs (hsa-miR-34c-5p, hsa-miR-410-3p, hsa-miR-301b-3p, and hsa-miR-145-5p) were selected for validation in an independent cohort of 52 patients with CKD. Increased urinary abundance of hsa-miR-145-5p was confirmed to be associated to progression of CKD. In vitro exploration of the effects of hsa-miR-145-5p inhibition in human kidney cells showed that the microRNA seemed to be involved in necrotic processes. In conclusion we have identified hsa-miR-145-5p as potential urinary microRNA marker of CKD progression. 2) The identification of microRNAs associated to obstructive nephropathy, a frequently encountered disease in children that can lead, in severe cases, to end stage renal disease (ESRD). In this study we used a comprehensive system biology analysis in which we combined micro- and mRNA data from human and animal obstructive nephropathy to obtain information on possible mechanisms involved in this disease. In particular, we have studied in parallel the urinary miRNome of infants with ureteropelvic junction (UPJ) obstruction and the kidney tissue miRNome and transcriptome of the corresponding neonatal partial unilateral ureteral obstruction (UUO) mouse model. Several hundreds of microRNAs and mRNAs displayed changed abundance during disease. Combination of microRNAs in both species and associated mRNAs let to the prioritization of 5 microRNAs and 35 mRNAs associated to disease. In vitro and in vivo validation identified consistent dysregulation of let-7a-5p and miR-29-3p and new potential targets, E3 ubiquitin-protein ligase (DTX4) and neuron navigator 1 (NAV1). Our study is the first to correlate a mouse model of neonatal partial UUO with human UPJ obstruction in a comprehensive systems biology analysis. Our data revealed let-7a and miR-29b as molecules potentially involved in the development of fibrosis in UPJ obstruction via the control of DTX4 in both man and mice that would not be identified otherwise

Background Chronic Kidney Disease (CKD) can be described as the loss of the kidney function over time. Symptoms usually develop slowly, and it may not appear in early stages. Lab tests can confirm a CKD diagnosis. The approximate number of incidents per year is more than 200,000 cases, and approximately 30 million people are living with CKD today in the United States. This long-standing disease ultimately leads to renal failure at the end. At this present time, there are no known cures for CKD, and the only treatment available is dialysis. Objectives The purpose of this study is to determine the association between CKD and further with hemodialysis (HD) and medical condition such as cardiac complications, cardiogenic shock, hemorrhage, anemia, vascular complication, postop respiratory failure, post op infarct hemorrhage, acute renal failure, new temporary pacemaker, new permanent pacemaker, pericardial complications, and death. Study design The study employed secondary data in a cross-sectional design. Methods A sample of 106,969 was drawn from the population. The outcome variables were a diagnosis of CKD and/or CKD with HD. The predictor variables were cardiac complications, cardiogenic shock, hemorrhage, anemia, vascular complication, postop respiratory failure, post op infarct hemorrhage, acute renal failure, new temporary pacemaker, new permanent pacemaker, pericardial complications and death. Logistic regression was conducted to analyze the relationship between outcome variable and each independent variable. Variables with a p-value Results Analysis shows that subjects with cardiac complications were 17% less likely to have CKD as compared to those who did not have cardiac complications (OR: 0.83, 95% CI: 0.78-0.88). CKD patients who had cardiac complications were 18% more likely to have HD than the subjects who did not have cardiac complications (OR: 1.18, 95% CI: 1.01-1.39). Patients with cardiogenic shock were 86% more likely to have CKD than the subjects who did not have cardiogenic shock (OR: 1.86, 95% CI: 1.82-1.91). CKD patients who had cardiogenic shock were also 18% more likely to have HD than the subjects who did not have cardiogenic shock (OR: 1.18, 95% CI: 1.11-1.25). We have similar results if a patient had other conditions. Conclusion Chronic kidney disease with hemodialysis is significantly associated by the other medical conditions such as cardiac complications cardiogenic shock, hemorrhage, anemia, vascular complication, postop respiratory failure, post op infarct hemorrhage, acute renal failure, new temporary pacemaker, new permanent pacemaker, pericardial complications and death in the United States. Further studies are needed to confirm the results and to understand the prognosis.

Kidney disease is an important contributor to the burden of ill-health worldwide. Genetic factors have an important role in determining which people are affected by kidney disease, and this study aimed to identify the genes responsible for disease in families in which unusual kidney diseases were transmitted in a pattern suggesting autosomal dominant inheritance. I performed genome-wide single nucleotide polymorphism-based linkage studies and identified two new human disease genes. Hypoxia Inducible Factor-2α (HIF2α) is a widely expressed transcription factor which is rapidly broken down in the presence of oxygen. When oxygenation is reduced it activates the transcription of many genes, including erythropoietin which stimulates red blood cell production. I identified a heterozygous activating mutation of HIF2α which cosegregated with autosomal dominantly inherited erythrocytosis and pulmonary arterial hypertension in a British family, producing a phenotype similar to the effects of high altitude exposure. In vitro studies demonstrated that the mutant protein has increased transcriptional activity under normoxia. This suggests that HIF2α plays an important role in regulating the organism-wide responses to oxygen availability. Complement Factor H Related protein 5 (CFHR5) is a homologue of the complement regulating protein Complement Factor H and is of incompletely understood function. I uncovered an in-frame heterozygous duplication of exons 2 and 3 of the CFHR5 gene which cosegregated with autosomal dominantly inherited microscopic and synpharyngitic macroscopic haematuria, glomerulonephritis and renal failure in 2 families with ancestry in the Troodos Mountains of Cyprus. The mutation results in the production of a protein with impaired affinity for complement deposited in the kidney. This disease, which I named CFHR5 nephropathy, is endemic in Cyprus, accounting for a significant proportion of renal disease on the island, and may be amenable to systemic treatments. These findings implicate CFHR5 as a new and important regulator of complement in the human kidney.

Introduction Chronic kidney disease (CKD) is a common and important public health problem, with significant impact on the person’s quality of life and chances of survival. Cardiovascular disease is major cause of morbidity and mortality among people with CKD. Cancer is also a well-recognised complication in people on dialysis and with kidney transplants, but has not been adequately assessed in people with mild to moderately reduced kidney function. It is uncertain whether the basis of such increased risk in the end-stage kidney and transplant populations is solely related to their immunocompromised health states, or there are plausible biological reasons to explain the association beyond current knowledge. Screening, which allows early detection and subsequent treatment, is effective in reducing cancer-related deaths for common cancer such as breast, colorectal and cervical cancers in the general population. Given the inherent differences in the overall cancer risk and life expectancy among people with CKD, it is plausible that the effects, costs, and harms of routine population cancer screening may be different to the general population. This thesis is presented as published work on the theme of cancer and chronic kidney disease. The first chapter summarises the existing epidemiological evidence of association between cancer and kidney transplantation. The second chapter, uses data from the Blue Mountain Eyes Study cohort and linkage with the New South Wales Central Cancer Registry, explores the hypothesis of increased cancer risk in people with mild to moderately reduced kidney function. The work presented in the last five chapters of this thesis have extrapolated, critically appraised, and synthesized the available evidence for cancer screening in the general, end-stage kidney disease and kidney transplant populations.

Autosomal dominant polycystic kidney disease (PKD) is caused by mutations of the PKD1 or PKD2 genes. Cyst cells exhibit sustained expression of fetal genes such as PAX2. Normally, PAX2 is involved in kidney development and is rapidly downregulated after birth. Overactivity of the canonical beta-catenin signaling pathway has also been linked to the formation of renal cysts. To determine whether beta-catenin activity is linked to the level of PAX2 expression in vivo, we created a transgenic mouse overexpressing PAX2 in mature proximal tubules of the kidney. Here we report that the canonical beta-catenin signaling activity is increased in mice bearing the targeted PAX2 transgene.
There is also evidence that non-canonical Writ signaling may be involved in the development of renal cysts but this pathway is uncharacterized. We therefore studied the ontogeny of a downstream marker of this pathway (NFAT) and its localization in the developing kidney. Here we report that NFAT activity is high in early stages of kidney development and is rapidly downregulated at birth. The NFAT signal is diffuse and is expressed in both mesenchymal and epithelial cells of the developing kidney.

During kidney development, there is a switch from predominantly canonical to non-canonical WNT signalling. This switch transitions the developing kidney from a state of active proliferation to that of terminal differentiation. The current belief is that a defect in this switch is an underlying mechanism in the pathogenesis of autosomal dominant polycystic kidney disease. We first hypothesized that a failure to suppress canonical WNT signalling would lead to cyst formation and following this line of reasoning, crossed a β-catenin transcriptional activity reporter mouse to mice with mutations in Pkd1 or Pkd2. We found no aberrant canonical WNT signalling in the epithelial cells lining the cysts and concluded that a failure to restrict β-catenin transcriptional activity does not occur in autosomal dominant polycystic kidney disease. We next examined if an inability to activate a non-canonical WNT signalling pathway, specifically the WNT-calcium pathway, contributes to cystogenesis. WNT-calcium signalling was not previously characterized in the developing kidney, so we first established cell culture, organ culture, and in vivo systems to study the pathway in a normal developmental context. We showed that pathway activity peaks from embryonic day (E)13 to E16 and is located in the nephrogenic zone of E16 kidneys. We further demonstrated that activation of the WNT-calcium pathway in vitro restricts cell motility, an important process during mesenchymal cell condensation to form the renal vesicle. To assess the role of WNT-calcium signalling in autosomal dominant polycystic kidney disease, we crossed an NFAT transcriptional activity reporter mouse to mice with mutations in Pkd2 and found that pathway activity is significantly reduced in cystic kidneys. Taken together, this study supports the hypothesis of a developmental switch between canonical and non-canonical WNT signalling during normal kidney development and suggests that a failure to fully activate the WNT-calcium pathway may be a contributing factor in the pathogenesis of autosomal dominant polycystic kidney disease.
Lors du développement rénal, il y a une permutation entre les voies canonique et non-canonique de signalisation WNT. Ce changement permet au rein en développement de passer d'un état de prolifération active à une différentiation terminale. La pensée actuelle est qu'une erreur lors de cette transition est un mécanisme sous-jacent dans la pathologie de la maladie polykystique autosomale dominante des reins. Nous avons tout d'abord émis l'hypothèse que manquer de réprimer la voie canonique de signalisation WNT conduirait à la formation de kyste. En suivant ce raisonnement, nous avons croisé des animaux disposant d'un gène rapporteur de l'activité transcriptionnelle de -caténine à ceux présentant des mutations dans Pkd1 ou Pkd2. Nous n'avons trouvé aucune signalisation aberrante de la voie canonique de WNT dans les cellules épithéliale tapissant les kystes et en avons conclu qu'un échec de restriction de l'activité transcriptionnelle de -caténine n'est pas la cause de la maladie polykystique autosomale dominante des reins. Nous avons ensuite examiné si une incapacité d'activer une voie non-canonique de signalisation WNT, plus précisément la voie WNT-calcium, contribue à la formation de kyste. La voie WNT-calcium n'a pas été caractérisée au préalable dans le rein en développement. Nous avons donc établi des cultures cellulaires, d'organe et des systèmes in vitro afin d'étudier la voie de signalisation dans un contexte développemental normal. Nous avons alors montré que l'activité de la voie de signalisation culmine au jour embryonnaire (E)13 à E16 et se localise dans la zone néphrogénique des reins E16. De plus, nous avons démontré que l'activation de la voie WNT-calcium in vitro réduit la motilité des cellules, un processus important lors de la condensation des cellules mésenchymateuses pour former la vésicule rénale. Afin d'évaluer le rôle de la voie de signalisation WNT-calcium dans la maladie polykystique autosomale dominante des reins, nous avons croisé des souris disposant d'un gène rapporteur de l'activité transcriptionnelle de NFAT à celles présentant une mutation dans Pkd2. Nous avons constaté que l'activité de la voie de signalisation est considérablement réduite dans les reins kystiques. Ensemble, cette étude confirme l'hypothèse selon laquelle il y aurait une permutation développementale entre les voies canonique et non-canonique de signalisation WNT durant le développement normal du rein, et suggère que l'absence de toute activité de la voie WNT-calcium pourrait être un facteur contribuant à la pathogenèse de la maladie polykystique autosomale dominante des reins.

Introduction: Chronic kidney disease (CKD) common, particularly in the elderly, and is linked to an increased risk of cardiovascular disease (CVD). This is partly explained by joint risk factors such as hypertension and diabetes but novel risk factors such as arterial stiffness, arterial calcification and endothelial dysfunction may play a role. Our aims were 1) to prospectively investigate whether aortic stiffness was linked with rate of decline of renal dysfunction, 2) to investigate the associations of arterial stiffness in patients with moderate renal dysfunction, and 3) to investigate whether aortic stiffness was linked with adverse outcomes. Secondary aims were to explore the links between 24 hour ambulatory blood pressure (BP) monitoring (24h ABPM), aortic stiffness, and the novel CV risk factors asymmetric dimethylarginine (ADMA) and Fetuin-A. Methods: This is an observational study of 133 patients with CKD stages 3-4 (estimated GFR 15-60mUmin). At baseline subjects underwent full assessment of CV risk, measurement of arterial stiffness, Fetuin-A, ADMA, and 24h ABPM. Patients were then followed-up with repeat of arterial stiffness measurements 6- monthly. Change in renal function and clinical events were recorded. Major results: Renal function is a determinant of aortic stiffness independent of other well-described factors. Aortic stiffness is closely linked to deterioration in renal function and predicts cardiovascular events within this cohort. There is a high prevalence of ambulatory hypotension during 24h ABPM in older patients with CKD, and a large difference in BP between clinic and home measurements. The BP difference is associated with aortic stiffness, and is suggestive of a causal relationship. A rise in BP at night is associated with increased aortic stiffness, as is the related measure of postural hypotension. ADMA levels are related to change in renal function, while Fetuin-A is related to change in aortic stiffness. Conclusion: In this predominantly elderly cohort of patients with CKD stages 3 and 4, aortic stiffness is associated with baseline and change in renal fundion, CV risk and BP pattems. This highlights the close links between macro- and microvascular disease and suggests that knowledge of aortic stiffness may be crucial in further understanding the pathophysiology and treatment of renal disease.

Kidney disease is a common, expensive, and growing worldwide health problem. Genetic factors play an important role in the aetiology of kidney disease. Current research suggests that these genetic factors are predominantly rare variants with large phenotypic effects. In this thesis I have used a range of genetic techniques to identify rare variants in different families with kidney disease, and to study how they might cause disease. The Turkish-Cypriot population of Northern Cyprus has a high incidence of renal disease, much of which is undiagnosed and may be inherited. I collected DNA from the entire population on renal replacement therapy and identified three individuals with the G871C mutation in COL4A3. I used conflicting homozygosity analysis to demonstrate a minimal shared haplotype, thus dating this mutation to 17 generations ago. I used linkage analysis and whole genome sequencing in a large Greek-Cypriot kindred to identify 3 novel non-synonymous variants associated with kidney disease. Expression of these variants was examined in cultured primary urothelial cells from this family. I have studied another large pedigree with maternal transmission of renal disease. Sequencing of the mitochondrial genome demonstrated the presence of a novel polymorphism in the heavy strand promoter region at homoplastic levels. Mitochondrial function in primary dermal fibroblasts demonstrated a significant reduction in baseline oxidative respiration with a compensatory increase in glycolysis. Lastly, I have studied a novel compound heterozygous mutation in VHL. This variant showed abnormal degradation of HIF without activation of HIF target genes in patient-derived B-cells. It is possible that these cells are able to employ some kind of VHL-independent HIF regulatory mechanism. These studies demonstrate, in differing ways, the challenges of linking phenotype to genotype. Understanding the pathological and therapeutic importance of genetic information will become increasingly important to our management of kidney disease in this post-genomic era.

Chronic kidney disease (CKD) is arguably the most common disease of older cats. A disproportionate number of younger, male cats with CKD was identified among a cohort of cats with CKD and was hypothesised to be due to membranous glomerulopathy or an FIV associated nephropathy. Examination of epidemiologic, histologic, immunohistologic and survival data revealed an association between the presence of CKD and FIV infection among young cats and an adverse effect of FIV infection on survival among cats with CKD, but no specific histological changes were seen among FIV positive cats. Glomerulopathies were identified among 16% of cats with CKD but more female than male cats were diagnosed with glomerulopathies and proliferative rather than membranous glomerulopathies were diagnosed more commonly. ' While glomerulopathies are the cause of CKD in a proportion of cats, membranous glomerulopathy is unlikely to be the predominant glomerulopathy and more work is required to define the both the pathophysiology and histology of feline glomerulopathies. A novel familial glomerulopathy was identified among young Abyssinian cats which was characterised by the presence of haematuria. Ultrastructural and immunhistochemical studies will be required to further characterise these glomerulopathies. Routine histologic examination of 95 cats with kidney disease confirmed the results of earlier studies regarding the proportions of cats with CKD with glomerulopathies, chronic tubulointerstitial nephritis (TIN) and pyelonephritis. A new observation was the significant number of cats had pathologic changes in the inner medulla and renal crest including necrosis and epithelial dysplasia. Bacteriuria was common among cats with CKD, in particular among older, female cats. There was no association between a positive urine culture and disease severity, assessed by creatinine concentration, and a treated episode of bacteriuria had no adverse influence on survival. Bacteria were infrequently identified in cats with neutrophilic TIN, including cats with a histologic diagnosis consistent with pyelonephritis. Further work is required to distinguish cats with asymptomatic bacteriuria from those with urinary tract infections and at risk of pyelonephritis. In addition, causes of neutrophilic TIN other than bacterial infection should be evaluated.

Chronic kidney disease (CKD) is insidious and most cases are diagnosed through opportunistic serum creatinine (SCr) testing before symptoms develop. However, efforts to accurately assess prevalence have been hampered by the lack of a universally agreed definition of SCr thresholds for the diagnosis of CKD. At the turn of the millennium, two crucial developments occurred. The first was the description of the Modification of Diet in Renal Disease estimated Glomerular Filtration Rate (eGFR) which closely correlated to cumbersome measured GFR and could be used instead in daily clinical practice. The second was the publication of the Kidney Disease Outcomes Quality Initiative (KDOQI) clinical practice guideline for the evaluation, classification and stratification of CKD detailing a new definition of CKD based on GFR thresholds. Together, these two developments formed the basis of CKD as we know it today. Prevalence of CKD varies, and accurate prevalence estimates are difficult to obtain especially with respect to fulfilling the chronicity criterion (reduced eGFR ≥ 90 days). Traditional risk factors for CKD are well described and non-traditional risk factors such as socio-economic status (SES), health literacy and rurality are gaining interest. SCr sampling patterns in the community mean that most individuals with CKD are tested routinely every year. This information may not be considered in its entirety by primary care providers (PCP) which may explain inaccuracies in PCP CKD registers. Accurate identification is important to direct evidence based clinical interventions to this patient group. In chapter 2, a novel algorithm for detecting CKD and confirming chronicity from a laboratory database was developed to identify a CKD cohort of the population served by NHS Ayrshire & Arran. Data linkage of additional laboratory data, Scottish Morbidity Records for co-morbidity, statin dispensing information from Prescribing Information Scotland, area SES, rurality and deaths from Information Services Division Scotland enriched the cohort. Patients on renal replacement therapy were identified and excluded through the Scottish Renal Registry. Multiple imputations were applied where appropriate to address missing values. There were 21,037 individuals from 2010 to 2012 fulfilling the definition of CKD stage 3 – 5. Prevalence of adults with CKD was 5.6% – 5.8%. Average age (± SD) of the cohort was 75 ± 11 years. 64.6% were female and average eGFR for the cohort was 47.32 ± 11.53 mL/min/1.73m2. In chapter 3, laboratory ascertainment of CKD identified 7% more cases than PCP CKD registers. Furthermore, around 25% of patients on PCP CKD registers may be wrongly coded as having CKD. There was a 3.9-fold variation in CKD prevalence amongst PCPs, ranging from 2.8% - 11.0%. Variation fell to 3-fold with laboratory ascertainment, ranging from 3.0% - 9.1%. This fell further with age and gender stratification. Stratified laboratory CKD prevalence was positively associated with SES and rurality, a novel finding, but in multivariate linear regression, only SES, in addition to age and gender, were significant predictors for CKD prevalence. Chapter 4 explored the association between SES, eGFR and all-cause mortality. One-way ANOVA demonstrates a linear relationship between eGFR and SES (F (4,15078) = 2.52, p = 0.039) with a mean difference in eGFR of 0.83 mL/min/1.73m2 between the lowest and the highest SES quintile. However, linear regression modelling found proteinuria, hypertension, peripheral arterial disease, age, gender and serum albumin to be significant predictors for eGFR, but not SES. After adjustment for age and gender imbalance, survival demonstrated substantial influence by SES, but weakened in effect with full adjustment with only Scottish Index of Multiple Deprivation (SIMD) quintile 3 demonstrating a 13% increased risk (HR 1.13, 95% CI 1.03 to 1.24) with no progressive increase in risk associated with lower levels of SES. As a quality of care marker, the dispensing of statin was examined in chapter 5. Having another diagnosis where statins are indicated, male gender, higher serum albumin, CKD stage 3B and age between 65 – 80 were associated with higher odds ratio for statin dispensing. 64% of the cohort was dispensed a statin in 2010, but the proportion fell by 5% to 58% in 2012. This fall in dispensing disproportionately affected younger and less co-morbid CKD patients who were all eligible for a statin. SES and gender did not appear to be a factor in falling dispensing rates. Average LDL levels were lower in the statin group by (mean difference) 0.78 mmol/L (95% CI 0.74 to 0.81) in 2010 and 0.93 mmol/L (0.90 to 0.97) in 2012. 37.2% of all statin prescriptions was for Simvastatin 40 mg. Statins reduce cardiovascular events and mortality in CKD. However, in older patients typical of CKD, evidence is lacking. Chapter 6 examines survival in those dispensed a statin. Those dispensed a statin were younger, more likely to be male, had higher serum albumin and more co-morbid. After full adjustment, statin dispensing was associated with a 24% lower risk of death (HR 0.76, 95% CI 0.71 to 0.83) overall, 18% benefit for primary prevention (no prior coronary heart disease or cerebrovascular disease) (0.82, 0.74 to 0.91), 32% benefit in secondary prevention (0.68, 0.60 to 0.77), 22% benefit in younger (< 76 years) CKD patients (0.78, 0.67 to 0.92) and 22% benefit in the older (≥ 76 years) CKD patients (0.78, 0.71 to 0.85) over 4.5 years follow-up. To illustrate absolute risk reduction, the number needed to treat to avoid one death for all patients is 15.8 (95% CI 12.3 to 22.2) and 12.4 (9.3 to 18.5) for older CKD patients. This thesis demonstrates that centralised ascertainment of CKD is better at case finding, than existing PCP CKD registers. The linkage of additional, routinely collated healthcare data can develop CKD registers into a powerful tool for monitoring quality of care, efficacy of therapy and hypothesis generation which can, and should be, integrated into clinical IT systems with the appropriate information governance oversight in place.

Introduction End stage kidney disease (ESKD) accounts for 5-10 million deaths annually worldwide. The current treatment modalities for ESKD include dialysis, transplant and supportive care. The leading cause of death for people with ESKD is cardiovascular disease (CVD). CVD is a collective term for disease affecting the heart and blood vessels including coronary, cerebral and peripheral blood vessels. CVD causes significant morbidity and has a substantial impact on quality of life for people with ESKD. Improving cardiovascular outcomes for people living with ESKD is a priority. The escalating incidence of chronic kidney disease, its progression to ESKD and the high burden of cardiovascular disease has generated an increasing amount of research in the ESKD population. The ESKD population have previously been under-represented in clinical trials and current trials in ESKD have infrequently and inconsistently reported CVD outcomes. It is important to standardise outcomes used in research. When outcome reporting is standardised it enables comparisons of findings across trials, populations and eras. It is important that the outcomes reflect patient priorities and are relevant to patients and clinicians for use in shared decision making. The Standardised Outcomes in Nephrology Group (SONG) is an international initiative to establish a set of core outcomes and outcome measures across the spectrum of kidney disease for trials and other forms of research. The SONG-Haemodialysis (SONG - HD) initiative is developing a core outcome set for use in haemodialysis. As part of SONG-HD, CVD (as well as fatigue, vascular access and mortality) has been identified as important to all stakeholders and included in the core outcome set for haemodialysis. This requires appropriate measures of CVD to be identified and used. The first aim of this thesis was to achieve consensus on a CVD outcome measure for use in haemodialysis trials. In approaching this goal I first needed to ascertain the current use of cardiovascular outcomes (Chapter 2) and then determine which ones were important to all stakeholders (Chapter 3). Consensus over which is the most appropriate measure of CVD for use in trials in people on haemodialysis (Chapter 4) will allow improved standardisation of cardiovascular outcome reporting, reducing research wastage and will propel forward cardiovascular research to improve morbidity and mortality in this high risk population. The second aim of this thesis was to further examine some of the prioritised outcomes and to review the patterns and risks of CVD in the ESKD population. The magnitude of risk for cardiac events and cardiac deaths in people with ESKD relative to the general population and the changes over time are not well described. I hypothesised that the magnitude of risk remained high in the ESKD population and that epidemiological improvements seen in CVD outcomes in the general population have not been mirrored in the ESKD population (Chapters 5 and 6). CVD and more specifically cerebrovascular disease can lead to significant cognitive impairment which has a substantial impact on the ability of ESKD patients to understand their disease, interpret education and be involved in shared decision making. The patterns of cognitive deficit in the ESKD population are not well understood and I hypothesised that cognitive deficits in the ESKD population may be different to those found in the general population and may differ by modality of renal replacement therapy. Standardising CVD outcomes, examining the epidemiology of CVD in ESKD and comparing the trends and patterns to the general population can drive hypotheses into potential causative mechanisms and new treatments. I present this thesis as a hybrid of published work, work currently under peer review for publication and work submitted for publication on the theme of priorities and outcomes in ESKD.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is among the most prevalent life-threatening genetic conditions. Despite this, no approved medical therapies exist to treat the disease. Until the recent past, no methods could reliably measure the course of the disease far in advance of end stage renal disease (ESRD). As normal tissue is progressively destroyed or blocked by enlarging cysts, remaining nephrons compensate in a process called hyperfiltration. This beneficial physiological response confounds tests of renal function. Thus, potential interventions could not be tested against a reliable measurement of disease progression.

However, progressive changes are visually apparent on medical imaging examinations throughout the course of ADPKD. The search for ADPKD proxy biomarkers is now focused on quantitative imaging, or the extraction of information from medical images for purposes of diagnosis or disease tracking. Recent studies from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)- sponsored Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) showed Total Kidney Volume (TKV) is a usable quantitative imaging biomarker which can track disease in the early, asymptomatic phase and register measurable changes in as little as 12 months. These findings launched several new trials into potential ADPKD therapies.

Advanced analysis of polycystic kidney images, however, has never been done. The method CRISP used to extract TKV was stereology, an efficient means to estimate volume. However, stereology was tradi- tionally a dead end for further advanced analysis. TKV is useful for clinical trials and large population-based studies, but cannot accurately predict disease progression or stratify risk due to known out- lier cases. Thus, the utility of TKV for individual patient prognosis is limited. This work builds upon stereology data, describing a reliable and accurate new semi-automatic method to fully segment images us- ing only labeled stereology grids. Then, two new second generation quantitative imaging biomarkers are introduced and analyzed: Cyst- Parenchyma Surface Area (CPSA) and cyst concentration. These new physiologically motivated biomarkers will complement or potentially replace TKV in efforts to bring quantitative imaging to individual patients.

The goal of this body of work is to enable a pathway for efficient advanced image analysis in ADPKD, never before attempted in this dis- order, and to define new quantitative imaging biomarkers which will complement or replace existing ones in hopes of making individualized disease tracking for ADPKD patients a reality.

Section A provides an overview of the role of family caregivers of individuals with chronic illness, and describes key conceptualisations and theories posited in the caregiver literature. This is followed by an overview of research conducted with caregivers of children with chronic kidney disease (CKD), a summary of the limitations of this research, and suggestions for future research. Section B Despite a recognised need to monitor caregiver burden in caregivers of children with CKD, there is no measurement tool currently available to meet this aim. The present research documents the development of a measure of caregiver burden specific to family caregivers of children with CKD. Methods: Interviews were conducted with 16 caregivers of children with CKD and 10 healthcare professionals in order to generate measure items. A provisional version of the measure was developed and piloted with 18 caregivers of children with CKD and five healthcare professionals. Results: An initial pool of 97 items was generated from the content of interviews, which was reduced to 60 items following review for item redundancy. A piloting exercise provided preliminary evidence for the usability, readability, and relevance of measure items; adaptations further to piloting resulted in the 51-item ‘Paediatric Renal Caregiver Burden Scale’ (PR-CBS). Conclusions: It is hoped that the PR-CBS will serve to identify areas of need amongst caregivers of children with CKD, and in turn improve outcomes for this caregiver population and children with CKD. Section C is a critical appraisal of the conducted research study, and includes an overview of research abilities acquired during its completion, reflections on how the research may have been conducted differently, implications for future clinical practice, and ideas for future research.

Polycystic kidney disease (PKD) is the most common inherited cause of kidney failure affecting 1 in 1000 adults and children worldwide. Many studies focus on the disrupted cellular functions within the cyst epithelia but promising therapeutic strategies have not yet translated to clinically approved treatments for human PKD. This thesis takes a different approach and hypothesised that cyst growth requires the support of the underlying renal microvasculature and that targeting vessels could be an alternative therapeutic strategy. The renal vasculature in cystic and wild-type kidneys was first characterised using a mouse model of autosomal recessive PKD (ARPKD). It was found that mRNA levels of markers of blood and lymphatic endothelium were altered in cystic kidneys compared with wild-type. By immunohistochemistry, there was disorganisation of the vasculature with expansion of lymphatic capillaries surrounding the smaller cysts and regression of the microvasculature surrounding the larger cysts. Overall, the peri-cystic microvasculature shifted from a blood to a lymphatic endothelial phenotype. To test the potential of targeting the renal vasculature as a treatment for PKD, vascular endothelial growth factor-C (VEGFC) was administered to mouse models of both ARPKD and autosomal dominant PKD (ADPKD). The treatment significantly reduced disease severity as measured by kidney/body weight ratio by at least 28% in both models. In the model of ADPKD, serum blood urea nitrogen was also significantly reduced by around 35% indicating an improvement in renal function. Measurement of cyst characteristics revealed improvements in percentage cyst area, total number of cysts per kidney and the average cyst size. The treatment also restored normal renal vascular patterning and decreased the number of CD206+ macrophage cells which contribute to cyst growth. This thesis suggests that targeting the renal vasculature could be a therapy for PKD, with the potential to enhance current approaches.

Introduction Podocytes are terminally differentiated, highly specialized glomerular cells that form the final barrier to protein loss. Podocyte injury is characterised by proteinuria. Proteinuria is an important prognostic marker in kidney diseases, and lowering proteinuria has become a principal clinical goal. Compelling evidence supports the notion that continuing loss of podocytes plays a major role in the initiation and progression of glomerular diseases. It is my hypothesis that interventions that reduce the disruption by rescuing susceptible podocytes next to injured ones are potential therapies to restore podocyte phenotype and filtration behaviour, thereby protecting the kidney from progressive deterioration. Prevention of this damage, or ways to aid its recovery, could therefore be important to improving the management of human kidney diseases. Methods Transgenic mice expressing the human diphtheria toxin receptor on podocytes had been previously generated in our laboratory. Characterization of two lines showed that graded specific podocyte injury could be induced by single intraperitoneal injection of diphtheria toxin. Eight-week intervention studies involved administration of oral drug in water or food from 24h after toxin injection. Two control groups received no drug or were non-transgenic (wild-type) littermates. Primary endpoints were glomerulosclerosis and kidney function (serum creatinine). Other readouts included blood pressure, albuminuria, serum albumin, podocyte quantification and collagen staining of kidney. The angiotensin converting enzyme inhibitor (ACEi) captopril was tested because of its proven protective effect on renal function in patients with proteinuria. Subsequently another proteinuria-reducing drug, the endothelin receptor A antagonist sitaxsentan was tested alone and in combination with captopril. Results Captopril reduced proteinuria and ameliorated scarring, with matrix accumulation and glomerulosclerosis falling almost to baseline. Podocyte counts were reduced after toxin administration and showed no significant recovery irrespective of captopril treatment. In the following sitaxsentan and captopril combined intervention study, glomerular scarring was significantly reduced in all drug-treated groups either alone or in combination, but only combination drug treatment reduced glomerular damage to levels comparable to wild-type controls, demonstrating a synergistic effect of the two agents. Similarly, serum creatinine was lowered further in combined but not single drug-treated groups. Blood pressure of all drug treated mice was lowered compared to the placebo group. Surprisingly in this second study there were no significant differences in proteinuria between treated and untreated groups. Conclusion These results support the hypothesis that continuing podocyte dysfunction is a key abnormality in proteinuric disease, and plays a major role in progressive glomerulosclerosis. Both captopril and sitaxsentan alone or in combination provided protection without substantial preservation or restoration of podocyte numbers at the degree of injury induced in these experiments. Combined therapy showed a synergistic effect in protecting the kidney from progressive damage. These results suggest that protection may be at least partly due to change in podocyte phenotype. The model is ideal for studying strategies to protect the kidney from progressive damage following specific podocyte injury. Further elucidations on the mechanism of action of the drugs may aid development of superior future therapeutic treatments in the field of renal diseases.

Le facteur de transcription Hepocyte Nuclear Factor 1β est nécessaire pour l’expression de plusieurs gènes kystiques et sa délétion prénatale induit une polykystose rénale. J’ai montré que l’inactivation de HNF1β chez la souris à partir de 10 jours après la naissance, après la fin de la prolifération morphogénique, ne provoque pas de dilatations tubulaires kystiques. La résistance kystogénique est intrinsèquement liée à la quiescence cellulaire. En effet, lorsque les cellules déficientes pour HNF1β sont forcées à proliférer avec une ischémie/reperfusion, elles donnent lieu à la formation de kystes après avoir perdu l’orientation de la division cellulaire. Il est remarquable que l’expression de cibles kystogéniques critiques soit maintenue même en l’absence de HNF1β. Cependant, l’expression des cibles est perdue lorsque les cellules prolifèrent et ces cibles acquièrent des marques d’hétérochromatinisation. Ces résultats constituent un nouvel aspect dans la régulation de l’expression génique. Il est généralement reconnu que la transcription des gènes est arrêtée pendant la condensation mitotique. Les facteurs de transcription comme HNF1β pourraient être impliqués dans la reprogrammation de l’expression génique après l’arrêt mitotique de la transcription. De plus, HNF1β reste accroché aux chromosomes mitotiques condensés et cette association est site-spécifique. Cette observation suggère que HNF1β est un facteur marque-page de la transcription nécessaire pour la réouverture de la chromatine après l’extinction de la transcription pendant la mitose

Mestrado em Biotecnologia
A doença renal poliquística autossómica dominante (ADPKD) é uma doença hereditária e monogénica comum que resulta no desenvolvimento de quistos renais que aumentam em tamanho e em número com o avanço da idade, muitas vezes conduzindo ao aparecimento da doença renal terminal. Cerca de 85% dos casos identificados são causados por mutações no gene PKD1, um gene complexo de elevadas dimensões (~ 47kb). Atualmente, a sequenciação completa do gene PKD1 permite, com elevada sensibilidade, detetar variantes alélicas e pode ser utilizada em determinadas situações clínicas para as quais as técnicas radiológicas não permitem obter um diagnóstico clínico definitivo. No entanto, o rastreio de mutações é muitas vezes inconclusivo devido à presença de várias cópias homólogas a este gene localizadas no cromossoma 16, e à elevada heterogeneidade alélica do PKD1. O presente trabalho teve como objetivo o desenvolvimento de um teste genético de diagnóstico para a ADPKD através da sequenciação da zona codificante e limites intrão/exão do gene PKD1, utilizando a tecnologia de Sanger e otimizado para amostras de sangue armazenadas em cartões FTA™. Procedeu-se à otimização da amplificação e sequenciação, das regiões de interesse, utilizando a tecnologia de BigDye™ Terminator V3.1 e o protocolo desenvolvido mostrou ser uma metodologia reprodutível. Mutações patogénicas foram rastreadas em amostras de dois indivíduos, não relacionados, com ADPKD. Num dos pacientes a análise revelou a presença de uma mutação causadora de um codão stop prematuro no exão 15, no segundo paciente foi detetada uma deleção de 19pb no intrão 31, originando uma alteração na frame de leitura e causando a terminação prematura da proteína. Além disso, a heterogeneidade do PKD1 foi verificada uma vez que foram detetadas várias variantes neutras nas amostras analisadas, sendo que três destas alterações resultaram em alteração de aminoácido. Este estudo demonstrou o potencial da sequenciação de Sanger no diagnóstico de doenças genéticas. Apesar de futuramente ser necessária a validação com mais amostras de pacientes com ADPKD, é possível concluir que a metodologia desenvolvida poderá conduzir a um diagnóstico genético eficaz.
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a common hereditary and monogenic disorder that results in renal cysts development that increases in number and size as the person gets older, often leading to end- stage renal disease. PKD1 is a large (~47kb) and complex gene that accounts for 85% of the identified cases of ADPKD. Currently, the full sequencing of PKD1 allows, with high sensibility, the detection of variations along the gene and this may be used in certain clinicai situations where imaging cannot provide a definitive clinicai diagnosis. However, the screening of mutation is often inconclusive because of multiple homologous copies of this gene on chromosome 16 and the high levei of allelic heterogeneity of PKD1. The research presented here had the objective to develop a genetic diagnostic test for ADPKD through PKD1 coding region and exon/intron boundaries sequencing, using Sanger technology and optimized for blood samples in FTA™ cards. The amplification and sequencing, using BigDye™ Terminator V3.1 technology, were optimized for the regions of interest, and the methodology showed to be reproducible. The screening for disease-causing mutations was performed in two unrelated individuais with ADPKD. The analysis revealed the presence of a truncating mutation in exon 15 in one of the patients, and a 19bp deletion in intron 31 of the other patient, which led to frameshifting and premature termination. In addition, the heterogeneity of PKD1 was observed, since there were detected several neutral variants in the analyzed samples, three of which resulting in amino acid substitution. This research demonstrated the potential of automated Sanger sequencing for diagnosis of genetic diseases. Although further validation using more samples from ADPKD patients is still needed, it is possible to conclude that this approach can lead to an effective molecular genetic diagnosis.

Patients with chronic kidney disease (CKD) are a group with a markedly increased risk of adverse events following cardiac surgery. A particular problem for these patients is the development of post-operative acute kidney injury (AKI), which is associated with a significant increase in morbidity and mortality. Currently, there are no effective therapies proven to modify AKI in patients undergoing cardiac surgery. This thesis has three parts. The first describes an analysis of the Barts Health NHS Trust cardiac surgical dataset. Specifically, outcomes of patients with CKD and AKI were examined. The second describes a randomized control trial that examined the effect of remote ischaemic preconditioning (RIPC) upon AKI and myocardial injury in patients with CKD undergoing coronary artery bypass graft surgery (CABG). The final part describes the development of a panel of AKI biomarkers to allow the accurate prediction of AKI in patients with CKD undergoing CABG. The aims of this thesis were: 1. In our local cardiac surgical cohort, a. To assess the effects of CKD upon outcomes after CABG. b. To asses the prognostic importance of AKI after CABG. 2. To assess the potential for RIPC to reduce AKI and myocardial injury in patients with CKD undergoing CABG. 3. To investigate the diagnostic performance of serum and urine AKI biomarkers in a population of patients with CKD undergoing CABG. Analysis of the Barts Health NHS Trust cardiac surgical dataset confirmed that patients with CKD account for almost one-third of patients undergoing CABG. However, these patients account for a disproportionate two-thirds of all early mortality. CKD was also independently associated with late mortality after CABG. AKI was common in these patients. AKI was associated with late mortality even after accounting for pre-operative comorbidity and surgical complexity. In the randomized control trial, RIPC showed no effect upon the incidence of AKI or myocardial injury in the. 86 patients with CKD recruited. Secondary analysis of serum and urine biomarkers collected found change in serum cystatin C and NGAL as impressive predictors of AKI in patients with CKD. They allowed accurate early prediction of AKI more than 24 hours before diagnosis was possible using serum creatinine.

People with chronic kidney disease (CKD) living in rural communities have a higher risk of mortality, morbidity, hospitalisation, and decreased quality of life. They are less likely to access nephrology services and receive the recommended testing and education about CKD. Many barriers to accessing healthcare exist for rural patients with CKD, including geography and travel, particularly in large countries like Australia. This thesis aims to summarise existing evidence, generate new and comprehensive knowledge about the experiences, perspectives and needs of rural patients in accessing kidney replacement therapy in Australia, and to develop a practical, evidence-based, consumer-driven framework for improving access to healthcare for rural people with CKD. Chapter 2 provides synthesised evidence from multiple qualitative studies on patients’ and caregivers perspectives on access to kidney replacement therapy to generate comprehensive insights across rurally diverse geographical settings and populations. Chapters 3 to 5 is a suite of qualitative studies that describe in-depth perspectives of rural patients, caregivers, and clinicians on access to dialysis and transplant. Chapter 6 is a survey of the financial impact of CKD on families in rural Australia. Chapter 7 describes a series of workshops conducted with patients, caregivers, and health professionals on identifying roles and priorities of a rural patient navigator program for patients with CKD in rural settings. In conclusion, this thesis identifies a plethora of barriers and challenges in accessing dialysis and transplantation for rural people with CKD in Australia. The findings highlight the need for education, particularly regarding treatment options, financial support, psychosocial services, and support in navigating complex healthcare services.

Although existing kidney tissue engineering systems and cell-based strategies favoured significant advances in the field, they cannot reproduce the organ’s complex architecture. This prevented the use of these tissues in studying kidney development realistically, modelling diseases, and establishing therapeutic approaches. To fill these gaps, we devised a 3D engineering system for rapid generation of custom-made geometrically predefined kidney units that more faithfully resemble their counterparts in vivo. Combining 3D printing and PDMS prototyping, we fabricated differently sized and shaped scaffolds into which MDCK cells were seeded and cultured under tubulogenic conditions. Cells grew and self-assembled into branched tubules with single lumen delimited by a polarised monolayered epithelium, exhibiting kidney-specific functions. To model polycystic kidney disease (PKD), we pharmacologically induced cyst formation within engineered tubules. Next, we tested and quantified different compounds’ effect on cyst regression, identifying new potential pharmacological treatment; we showed that 2-deoxy-D-glucose is more effective than other compounds and discovered that berberine possesses high therapeutic potential for PKD treatment. Optimising the protocol and using different human iPSC lines, we successfully engineered functional human ureteric bud (UB)-like tubules capable of recapitulating early steps of UB morphogenesis. Exploiting these developmental capacities, we used tubules to identify a novel growth factor combination that induces budding events in a way comparable to mouse embryonic kidneys and that may therefore be involved in human UB development. Observing a marked reduction of ramified buds in tubules derived from a patient with heterozygous PAX2 mutation affected by focal segmental glomerulosclerosis, we speculated that such developmental disorder might have contributed to the patient’s condition. Overall, these findings document that our innovative and robust technology for controlled tubule engineering provides a valuable and reliable platform for kidney disease modelling, drug discovery and developmental studies, and may lay the groundwork for creating anatomically correct kidney tissue in vitro.

Cardiovascular (CV) disease is the commonest cause of mortality in CKD. CV mortality is not entirely explained by traditional CV risk factors and therefore systemic inflammation and vitamin D deficiency are thought to play a major role in CKD. Vitamin D [25 (hydroxy vitamin D; 25(OH)D] modulates adaptive immune responses and 25(OH)D deficiency is associated with CV mortality. Vascular endothelial dysfunction is a surrogate marker of atherosclerotic CV disease and related to systemic inflammation in CKD. However, the role of vitamin D on inflammation and endothelial function in CKD is largely unknown, which I aimed to investigate.

Introduction Addressing the gap in health between Aboriginal and Torres Strait Islander and non-Indigenous Australians is a national health priority. The life expectancy of Aboriginal and Torres Strait Islander Australians is currently 70 years for males and 74 years for females, which is 10 years lower than that of non-Aboriginal Australians. Around 80% of the mortality gap is attributable to chronic disease across all ages, with cardiovascular diseases specifically accounting for around 24% of the mortality gap. Aboriginal and Torres Strait Islander Australians have a higher prevalence of cardiovascular disease (27% vs 21%), diabetes (18% vs 5%) and chronic kidney disease (22% vs 10%), with Aboriginal and Torres Strait Islander showing higher prevalence of these conditions during early adult life. Rates of end stage kidney disease are five-fold higher among Aboriginal and Torres Strait Islander Australians compared to non-Indigenous Australians. Cardiovascular disease, diabetes and chronic kidney disease have a number of shared risk factors such as obesity, smoking, hypertension, diet and physical activity as well as perinatal risk factors such as low birth weight. Almost all studies investing the prevalence of risk factors for chronic disease have been cross sectional, with very few having tracked the risk of developing chronic kidney disease through childhood and adolescence into adult life. The Antecedents of Renal Disease in Aboriginal Children (ARDAC) is a population based long-term cohort study, the details of which have been published previously. Commenced in 2002, at an average age of 8.9 years, the original cohort of ARDAC participants has been followed up through mid-childhood, and at four years of follow up (at an average age of 13.3 years) no differences in the prevalence of albuminuria, high systolic blood pressure or obesity between Aboriginal and non-Aboriginal children were observed. The overarching hypothesis of my doctoral research is the higher prevalence of chronic disease in Aboriginal people becomes evident in adolescence and early adult life, and that this inequity is largely explained by the social determinants of health. The aims of my doctoral research was to extend the follow up of the ARDAC Study to 10 years (mean age 16 years), and compare the prevalence of albuminuria and change in blood pressure and body mass index (BMI) from childhood to adolescence using a longitudinal approach to data analysis. I also investigated the influence of the risk factors of residential remoteness, socioeconomic status and birth weight on these early indicators of adult chronic disease. I also aimed to further investigate the influence of the social determinants of health on the incidence of chronic kidney disease through a systematic review of the literature and meta-regression analysis. Finally I aimed to investigate the prevalence of obesity and hypertension in young people in the general Australian population though use of the microdata available from the Australian Health Survey, and to identify behaviour risk factors for hypertension and obesity. Beginning the trajectory to ESKD in adult life: Albuminuria in Australian Aboriginal children and adolescents Globally, disadvantaged populations suffer a high burden of chronic kidney disease. The trajectory to chronic kidney disease during childhood and adolescence remains unclear due to a paucity of longitudinal studies. 3418 participants (1469 non-Aboriginal and 1949 Aboriginal) were enrolled in a prospective, population based cohort study at participating schools across New South Wales (NSW), Australia since 2002. Albumin: creatinine ratio was measured by dipstick every two years along with body mass index (BMI), blood pressure. We used multivariable logistic generalised estimating equation models to examine if Aboriginal children had a higher prevalence of albuminuria compared with non-Aboriginal children with increasing age, and to identify potential risk factors. At enrolment with a mean age of 10.6 years, 14.2% of children were obese and 16.0% overweight, and 11.5% were found to have albuminuria. Over 8 years (11,387 participant-years) of follow up the prevalence of albuminuria increased to 18.5%, overweight to 16.1% and obesity to 17.2%. BMI standard deviation score (SDS) was found to have a differential effect on the risk of albuminuria in Aboriginal and non-Aboriginal children (P interaction < 0.01). The prevalence of albuminuria decreased as BMI SDS increased in both groups of children, but more in non-Aboriginal children, leading to a 2.5% higher prevalence of albuminuria in overweight Aboriginal children (95 CI%: 1.0 to 4.2%). Compared with non-Aboriginal children, Aboriginal children are of higher risk of albuminuria when overweight or obese. These findings suggest that interventions to reduce the prevalence of overweight and obesity, particularly in adolescence and early adult life, are of critical importance to reduce the higher burden of chronic kidney disease experienced by Aboriginal Australians. The differential effect of socioeconomic status, birth weight and gender on body mass index in Australian Aboriginal Children Adult Aboriginal Australians have 1.5 fold higher risk of obesity but the trajectory of body mass index (BMI) through childhood and adolescence and the contribution of socioeconomic factors remain unclear. Our objective was to determine the changes in BMI in Australian Aboriginal children relative to non-Aboriginal children as they move through adolescence into young adulthood, and to identify risk factors for higher BMI. A prospective cohort study of Aboriginal and non-Aboriginal school children commenced in 2002 across 15 different screening areas across urban, regional and remote New South Wales, Australia. Socio-economic status was recorded at study enrolment and participants’ BMI was measured every 2 years. We fitted a series of mixed linear regression models adjusting for age, birth weight and socioeconomic status for boys and girls. 3418 (1949 Aboriginal) participants were screened over a total of 11,387 participant years of follow up. The prevalence of obesity was 14.2% (mean age 11 years) at baseline, and increased to 17.2% by a mean age of 16 years. The mean BMI increased with age and was significantly higher among Aboriginal girls compared to non-Aboriginal girls (P<0.01). Girls born at low birth weight had a lower BMI than girls born of normal birth weight (P<0.001). Socioeconomic status and low birth weight had a differential effect on BMI for Aboriginal boys compared to non-Aboriginal boys (P for interaction = 0.01). Aboriginal boys of highest socioeconomic status, unlike those of lower socioeconomic status, had a higher BMI compared to non-Aboriginal boys. Non-Aboriginal boys of low birth weight were heavier than Aboriginal boys. Socioeconomic status and birth weight have differential effects on BMI among Aboriginal boys, and Aboriginal girls had a higher mean BMI than non-Aboriginal girls through childhood and adolescence. Intervention programs need to recognise the differential risk for obesity for Aboriginal and non-Aboriginal boys and girls to maximise their impact. Blood pressure in Aboriginal and non-Aboriginal children through childhood and adolescence Hypertension is associated with an increased risk of chronic kidney disease (CKD) in adulthood. Aboriginal adults have a higher prevalence of hypertension, but whether this develops during childhood and adolescence is unclear. Our aim was to determine relative changes in blood pressure between Aboriginal and non-Aboriginal children as they move through adolescence into young adulthood. A prospective cohort study of Aboriginal and non-Aboriginal schoolchildren commenced in 2002 across NSW. Blood pressure was measured every 2 years. We fitted a series of mixed linear regression models for systolic and diastolic blood pressure adjusting for age, sex, Aboriginality, birth weight and socioeconomic status (SES). 3418 (1949 Aboriginal) participants were screened over a total of 11, 387 participant years follow up. At study enrolment at a mean age of 11 years, , the prevalence of high systolic blood pressure (SBP SDS > 95th centile) was 7.2% which increased to 15.4% at eight years follow up (mean age was 15.36 years). Although age and birth weight had a differential effect on systolic blood pressure for Aboriginal boys, the difference in systolic blood pressure was minor. The was no difference in the systolic blood pressure of Aboriginal girls compared to non-Aboriginal girls. For both boys and girls, lower socioeconomic status was associated with an increase in systolic blood pressure of approximately 2.5 mmHg. The prevalence of high diastolic blood pressure was approximately 3% for both boys and girls and remained constant over follow up. Socioeconomic status had a differential effect on blood pressure for Aboriginal children, with lower socioeconomic status associated with lower diastolic blood pressure for both boys and girls. The prevalence of high systolic blood pressure increased through adolescence, with no difference in systolic blood pressure for Aboriginal participants compared to non-Aboriginal participants. Low socioeconomic status is associated with an increase in systolic blood pressure among children and adolescents, and targeted intervention for young people of low socioeconomic status is required to control blood pressure within our community. The social determinants of chronic kidney disease: a systematic review Socio-economic disadvantage is increasingly recognised as an important risk factor for chronic disease, but the strength of the association with the development of chronic kidney disease (CKD) and the contribution of the various domains of disadvantage are uncertain. The aim of this study was to synthesise the evidence regarding the risk of CKD and end stage kidney disease (ESKD) in the general population according to markers of socio-economic disadvantage. We performed a systematic review and meta-analysis of published primary articles in MEDLINE, EMBASE or CINAHL (until December 2014), risk of bias was assessed using the Newcastle Ottawa Scale and summary effects were estimated using random effects meta-analysis and meta-regression. Cohort studies conducted in the general population and the social determinants of health investigated were ethnicity, education, income, occupation and area level measures of socio-economic status with the outcome of interest incident CKD (any stage). We identified 21 studies (n=12,987,147) - 13 investigated risk by ethnicity, education (9), income (6), area level socio-economic status (4) and occupation (2). Only two of the included studies were of high risk of bias. Black Americans have more than double the risk of ESKD compared to white Americans (hazard ratio 2.33, 95% confidence interval 2.02 to 2.63, I2 59%). Low income was found to increase risk of ESKD in four of the six studies identified, however low education and low SES were not consistently identified as risk factors for CKD. Measurement of domains, and thresholds used to define disadvantage were heterogeneous so that summary estimates were generally not able to be calculated. Although there is a substantial body of evidence regarding the association between socioeconomic disadvantage and CKD, there appears to be an inconsistent relationship. This may be artefactual, due to difficulties in quantifying disadvantage, or reflect true underlying differences in the association across different settings. Obesity and hypertension in Australian young people: Results from the Australian Health Survey 2011 to 2012 Few studies have focused on the prevalence of hypertension and obesity among young people (ages 15 to 25), although there is increasing awareness that preventative programs need to target this age group. We examined the prevalence of overweight, obesity and hypertension among 2 163 young people in Australia using data from the Australian Health Survey 2011 to 2012 and aimed to identify behavioural risk factors using logistic regression. The prevalence of obesity increased from 7.5% to 15% through the ages of 15 to 25 among boys, whilst the prevalence of overweight and obesity remains constant among girls throughout this age group (14%). Low levels of physical activity was shown to be a strong risk factor for obesity for both boys (odds ratio 5.95, 95% CI 1.83 to 19.36) and girls (OR 3.20 95% CI 0.69 to 14.87). Low socioeconomic status was associated with obesity among girls only. Although the prevalence of hypertension is low in this age group, the prevalence of high normal blood pressure is high especially among men (28% men and 14% women). Our results suggest that programs targeting physical activity participation should be tailored differently for boys and girls, with a focus on girls during late childhood and early adolescence but late adolescence and early adult life for boys.

La malaltia cardiovascular és la primera causa de morbiditat i mortalitat mundial. Els individus amb diabetis i malaltia renal crònica (MRC) presenten un major risc d’esdeveniments cardiovasculars (ECV) respecte a la població general. En la diabetis, l’increment de el risc cardiovascular és heterogeni i s’ha relacionat amb el grau d’afectació renal. D’altra banda, els algoritmes tradicionals per calcular el risc cardiovascular no traslladen amb suficient precisió el risc futur de ECV. L’avaluació de l’aterosclerosi subclínica (AS) mitjançant ecografia multiterritorial representa una eina vàlida per refinar el risc cardiovascular. El propòsit d’aquesta tesi va ser analitzar mitjançant ecografia multiterritorial la prevalença, distribució i progressió de AS, així com factors de risc associats, en una àmplia cohort de pacients, sense malaltia cardiovascular, amb MRC i amb i sense diabetis. Posteriorment, es va avaluar el valor pronòstic de l’AS per determinar la incidència d’ECV en aquesta població d’alt risc. Inicialment, es van analitzar les dades dels subjectes amb MRC, amb diabetis i sense diabetis, de la cohort de l’estudi NEFRONA reclutats a l’inici de l’estudi i que van assistir a la visita de control als 24 mesos. Després de realitzar un estudi ultrasonogràfic carotidi i femoral tant en la visita inicial com en la de seguiment, es va avaluar la correlació de factors de risc associats amb prevalença i progressió de placa mitjançant anàlisi multivariables. Així mateix, es va realitzar una altra anàlisi amb tots els subjectes de l’estudi, amb i sense diabetis, reclutats inicialment i als quals se’ls va seguir durant 48 mesos. Durant el període de seguiment es van registrar els ECV incidents. Es van utilitzar anàlisis bivariades i anàlisi de model de riscos competitius de Fine-Grey per a l’estudi estadístic. L’índex C es va estimar per als models de risc resultants amb més potència. Com a resultats, es va observar que la proporció d’individus amb placa basal va ser més gran entre els subjectes amb diabetis. Els subjectes amb diabetis també van presentar amb més freqüència l’afectació amb placa de més de dos territoris vasculars. També es va observar més progressió de placa entre els individus amb diabetis. Després de realitzar l’anàlisi multivariable, es va demostrar que la presència de placa basal s’associava amb l’edat, el gènere masculí, l’hàbit tabàquic i la diàlisi en els subjectes sense diabetis mentre que, en els subjectes amb diabetis, la presència de placa basal es associar tan sols a l’edat i al gènere masculí. La progressió de placa es va associar a l’edat, a el nombre de territoris amb placa basal, a l’hàbit tabàquic i a la diàlisi en els dos grups. Es van registrar un total de 107 ECV entre els subjectes sense diabetis (19.58 per 1000 anys-persona) i 96 entre els subjectes amb diabetis (44.44 per 1000 anys-persona). El model que millor va predir futurs ECV en individus sense diabetis contenia les variables: edat, 25-OH vitamina D i nombre de territoris amb placa basal. Entre els participants amb diabetis el model més robust en predir ECV incidents contenia tan sols la variable nombre de territoris amb placa basal. Per a tots dos models, l’índex estadístic C, estimat als 24 i als 48 mesos, va ser superior a 0.70. La AS és més prevalent, comporta major càrrega i és més progressiva en individus amb MRC i diabetis. En aquests subjectes, la diabetis supera altres factors de risc descrits. Així mateix, la càrrega d’AS és el predictor més potent de futurs ECV en individus amb diabetis i MRC. La detecció precoç de càrrega AS mitjançant ultrasonografia multiterritorial podria millorar la predicció de ECV en aquesta població.
La enfermedad cardiovascular es la primera causa de morbilidad y mortalidad mundial. Los individuos con diabetes y enfermedad renal crónica (ERC) presentan un mayor riesgo de eventos cardiovasculares (ECV) con respecto a la población general. En la diabetes, el incremento del riesgo cardiovascular es heterogéneo y se ha relacionado con el grado de afectación renal. Por otra parte, los algoritmos tradicionales para calcular el riesgo cardiovascular no trasladan con suficiente precisión el riesgo futuro de ECV. La evaluación de la aterosclerosis subclínica (AS) mediante ecografía multiterritorial representa una herramienta válida para refinar el riesgo cardiovascular. El propósito de esta tesis fue analizar mediante ecografía multiterritorial la prevalencia, distribución y progresión de AS, así como factores de riesgo asociados, en una amplia cohorte de pacientes, sin enfermedad cardiovascular, con ERC y con y sin diabetes. Posteriormente, se evaluó el valor pronóstico de la AS para determinar la incidencia de ECV en esta población de alto riesgo. Inicialmente, se analizaron los datos de los sujetos con ERC, con diabetes y sin diabetes, de la cohorte del estudio NEFRONA reclutados al inicio del estudio y que asistieron a la visita de control a los 24 meses. Tras realizar un estudio ultrasonográfico carotídeo y femoral tanto en la visita inicial como en la de seguimiento, se evaluó la correlación de factores de riesgo asociados con prevalencia y progresión de placa mediante análisis multivariables. Asimismo, se realizó otro análisis con todos los sujetos del NEFRONA, con y sin diabetes, reclutados inicialmente y a los que se les siguió durante 48 meses. Durante el periodo de seguimiento se registraron los ECV incidentes. Se utilizaron análisis bivariados y análisis de modelo de riesgos competitivos de Fine-Grey para el estudio estadístico. El índice C se estimó para los modelos de riesgo resultantes con mayor potencia. Como resultados, se observó que la proporción de individuos con placa basal fue mayor entre los sujetos con diabetes. Los sujetos con diabetes presentaron con mayor frecuencia la afectación con placa de más de dos territorios vasculares. También se observó una mayor progresión de placa en los individuos con diabetes. Tras realizar el análisis multivariable, se demostró que la presencia de placa basal se asociaba con la edad, el género masculino, el hábito tabáquico y la diálisis en los sujetos sin diabetes mientras que, en los sujetos con diabetes, la presencia de placa basal se asoció tan sólo a la edad y al género masculino. La progresión de placa se asoció a la edad, al número de territorios con placa basal, al hábito tabáquico y a la diálisis en ambos grupos. Se registraron 107 ECV entre los sujetos sin diabetes (19.58 por 1000 años-persona) y 96 entre los sujetos con diabetes (44.44 por 1000 años-persona). El modelo que mejor predijo futuros ECV en individuos sin diabetes contenía las variables: edad, 25-OH vitamina D y número de territorios con placa basal. Entre los participantes con diabetes el modelo más robusto en predecir ECV incidentes contenía tan sólo la variable ‘número de territorios con placa basal’. Para ambos modelos, el índice estadístico C, estimado a los 24 y a los 48 meses, fue superior a 0.70. La AS es más prevalente, conlleva mayor carga y es más progresiva en individuos con ERC y diabetes. En estos sujetos, la diabetes supera otros factores de riesgo descritos. Así mismo, la carga de AS es el predictor más potente de futuros ECV en individuos con diabetes y ERC. La detección precoz de carga AS mediante ultrasonografía multiterritorial podría mejorar la predicción de ECV en esta población.
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Individuals with diabetes and chronic kidney disease (CKD) have remarkably high rates of CVD risk. Moreover, incremental cardiovascular risk in diabetes is heterogeneous and has been often related to concomitant CKD. Typically used risk equations based on traditional cardiovascular risk factors fail to accurately predict cardiovascular risk not only in the general population but also in these subsets of the population. Multi-territorial ultrasonography to assess subclinical atherosclerosis (SA) has emerged as a valid tool to refine cardiovascular risk assessment beyond traditional risk factors. The purpose of this thesis was to analyse the prevalence, distribution, and progression of SA, as well as the associated cardiovascular risk factors in a large cohort of CKD subjects with and without diabetes, free from CVD, using multi-territorial ultrasonography. Subsequently, we further evaluated the prognostic value of SA in determining the incidence of first cardiovascular events (CVE) in this high-risk population. First, we included the data from CKD subjects with and without diabetes and free from previous CVE from the NEFRONA cohort, that were recruited at baseline, and that attended a follow-up visit 24 months later. Participants underwent carotid and femoral ultrasound examinations at baseline and at 24-month follow-up. Risk factors associated with the prevalence and progression of SA were evaluated using multivariate model analyses. In the second hand, we also conducted another analysis including data from the NEFRONA cohort subjects with and without diabetes that were recruited initially and were followed-up for 48 months. During the follow-up period, all CVE were registered. Bivariate analysis and Fine-Gray competing risk models were used to perform the statistical analysis. Concordance Index (C-statistics) was estimated for the strongest resulting risk models. We found that at baseline, the proportion of subjects with plaque at any of the examined territories was higher among diabetic individuals. Diabetic subjects more frequently had more than two vascular territories with plaque. During a 24-month follow-up period, plaque progression occurred in 72.2% individuals with diabetes whereas, among individuals without diabetes, plaque progression occurred in 55.8%. Multivariable analysis indicated that plaque at baseline was significantly associated with age, male gender, smoking, and dialysis in the non-diabetic subjects, while only age and male gender were associated with plaque presence in diabetic subjects. Plaque progression was significantly associated with age, the number of territories with basal plaque, smoking, and renal replacement therapy in both groups. Additionally, during a mean follow-up time of 48 months, CVE rate among participants without diabetes was 19.58 per 1000 person-years and 44.44 per 1000 person-years among participants with diabetes. After competing risk analyses and model selection, those variables that better predicted CVE in individuals without diabetes were the number of territories with plaque, age and serum concentrations of 25-OH vitamin D. Among participants with diabetes, the strongest model predicting incident CVE had only one variable: the number of territories with basal plaque. For both models, the concordance (C) index score was greater than 0.7 at both 24 and 48 months. We concluded that SA is more prevalent, carries a higher plaque burden, and is more progressive in CKD subjects with diabetes than in CKD subjects without diabetes. In these individuals, diabetes outweighs other risk factors associated with the presence of SA. SA is the strongest predictor of future CVE in diabetic individuals with CKD. Early detection of the SA burden by multi-territorial vascular ultrasound could improve CVE prediction in this population.

Thesis (Ph. D.)--University of Sydney, 2006.
Title from title screen (viewed 21 May 2007). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Public Health, Faculty of Medicine. Includes bibliographical references. Also available in print form.

Chronic kidney disease (CKD) is a significant public health issue. The uraemic milieu is associated with profound alterations in body composition and function. Therapeutic interventions to preserve renal function and to provide adequate homeostasis to improve outcomes in all stages of chronic kidney disease may promote other unwanted functional adversities which with careful attention to individualised treatment may be modifiable. The aim of this thesis is to clearly document these disorders of body composition and function and investigate whether commonly practiced interventions can indeed have additional deleterious impact. Our work involved subjects with different levels of CKD and included: • Antihypertensive therapy and falls in older persons with CKD 3/4. • Assessment of dynamic bone function in ERF subjects treated with haemodialysis and consequences of phosphate binder medication. • Distinguishing the dominant cardiac functional abnormalities in ERF subjects treated with haemodialysis and determination of the effects of haemodialysis on camitine depletion and its functional consequences (skeletal and myocardial). Key results included: • Antihypertensive therapy in older subjects with CKD was associated with a reduction in muscle mass over time and reduced overall function but no significant falls risk was noted. • Commonly utilised measurements to determine bone turnover in ERF subjects treated with haemodialysis do not appear to correlate with dynamic collagen formation rates. • Dobutamine-atropine stress with non-invasive assessment of cardiac parameters can be used to identify the dominant functional abnormalities that predispose to intradialytic hypotension in ERF subjects. • Skeletal muscle total carnitine decreases over the first 12 months of dialysis. Change in muscle total carnitine correlated weakly with exercise capacity. Carnitine replacement did not confer any measurable cardiovascular benefit over the first 12 months of dialysis. Body composition is highly variable over time in CKD. This is seen both in subjects receiving haemodialysis and in pre-dialysis patients. The interplay of these common alterations with the effects of treatments is potentially underestimated but should always be considered in the individualisation of patient care.

First year death rates remain unacceptable high for the end-stage renal disease (ESRD) population. New effective methods are vital to improve first year morbidity and mortality outcomes for the population transitioning from Stage 4 chronic kidney disease (CKD) to ESRD)/Stage 5 CKD. Based on current methods, evidence-based recommendations made by nephrology providers are frequently not heeded by patients in Stage 4 CKD. Low levels of patient knowledge, self-efficacy, and a poor ability to self-manage CKD negatively influence a patient's ability to follow provider recommendations. The group visit (GV) intervention has demonstrated improvements in disease-related outcomes through increased levels of patient knowledge, self-efficacy, and disease self-management for other chronic diseasses such as diabetes and congestive heart failure (CHF). No data are available for the use of GVs in CKD. The purpose of the study was to develop and test a nurse practitioner-facilitated chronic CKD GV model versus usual nephrology care for Stage 4 CKD patients (knowledge, self-efficacy/self-management, physiological data, and satisfaction). As classified by the National Kidney Foundation's (NKF) staging system, Stage 4 CKD is considered severe kidney disease, with a decrease in the functional capacity of the kidney as determined by a glomerular filtration rate (GFR) of 15-30 ml/min. It is common for patients with Stage 4 CKD to progress to Stage 5 CKD/end-stage renal disease (ESRD), requiring dialysis or transplantation to survive. Preliminary instrumentation and feasibility studies were conducted prior to a pilot study of a CKD GV model. The development and validation of the Stage 4 CKD Knowledge Instrument was completed with 59 Stage 4 patients. Findings supported reliability (Kuder-Richardson-20 [KR] = .89) and content validity (I-CVI = .97, S-CVI= 1.0) Feasibility of the CKD GV model was assessed with a single group, pretest-posttest design using a convenience sample of eight Stage 4 patients. Results demonstrated an improvement in knowledge of CKD from a median of 69% to 86% (p =.012). No improvements were noted in self-efficacy scores (p = .230). GV satisfaction ranged from very good to excellent. Feasibility was supported by a high retention rate (100%). No barriers to participant recruitment or GV implementation were encountered. The pilot study used a two-group, repeated measures experimental design, with a sample of 30 Stage 4 CKD patients from two office locations of an outpatient nephrology practice. Patients were randomized to the GV intervention or to usual nephrology care. CKD-knowledge, self-efficacy, and self-management scores were collected at baseline, six months, and nine months. Physiological data were measured at baseline, six months, and nine months. GV satisfaction was obtained after the completion of GVs (six months). Nephrology practice satisfaction was obtained from by both groups at nine months. MANOVA for repeated measures was calculated for data collected at the three time points. Twenty-six of 30 patients completed the study, with four patients ineligible to complete the study due to progression to ESRD and dialysis initiation. GV attendance was 92%. CKD knowledge was statistically improved for both groups (F(1.498, 34.446) = 6.363, P = .008). While not statistically significant, a favorable upward trend in the mean scores for the subscales of self-management (communication, partnership in care, and self-care) was demonstrated in the GV patients, with a lack of improvement found in the usual care group for these subscales. Self-efficacy scores revealed a non-significant improvement in mean scores for the GV patients during the GVs, not seen with usual care patients. GV satisfaction was again high with the vast majority of patients requesting use of GVs in their future nephrology care. Current methods of intervention in the Stage 4 CKD population have made little impact on reducing first-year ESRD mortality and morbidity rates. Opportunities to intervene in the poor outcomes begin in the predialysis care of Stage 4 patients. Based on the documented success of multidisciplinary approaches in predialysis care, of GVs in other chronic diseases, and of chronic illness care based on the CCM, a high probability for success exists with the application of GVs in CKD. Although limited by a small sample size, promising improvements in the subscales of disease self-management, self-efficacy, CKD knowledge, and high satisfaction with the GV model for GV participants were revealed in this study. Further research is warranted for the CKD GV model on a larger randomized sample in other locations. Much needed data would be provided on which to base decisions for use of the CKD GV intervention in the predialysis care of Stage 4 patients.
Ph.D.
Doctorate
Nursing
Nursing
Nursing

Planar cell polarity (PCP) is a signalling pathway regulating epithelial cell alignment and coordinated organisation, processes that are essential for the development and maintenance of healthy organs and tissues. In this thesis, I hypothesised that the core PCP protein, Celsr1 is essential for normal kidney development. Furthermore, I predicted that PCP proteins would be disrupted in a model of renal disease induced by folic acid. Kidneys of mice homozygous for a mutation in Celsr1 (Celsr1Crsh/Crsh) were significantly smaller compared with wild-type littermates and contained a reduced number of ureteric bud tips as assessed by optical projection tomography at embryonic day (E)13.5. The size of the bud tips and the angle at which they branched were unchanged. At E17.5, orientation of mitotic chromosomes was significantly disrupted in Celsr1Crsh/Crsh mutants compared with wild-type embryos. There was an occasional dilatation of proximal tubules and Bowman’s capsules surrounding the glomeruli, but not an overtly-cystic phenotype. I also examined whether Celsr1 interacted with another PCP component, Vangl2 in kidney development. I found that E13.5 Celsr1Crsh/+:Vangl2Lp/+ double heterozygous kidneys were also smaller compared with wild type littermates and had a significantly reduced UB tip number. At E17.5, a loss of corticomedullary differentiation with very few fully developed glomeruli and a disrupted mitotic orientation were observed in Celsr1Crsh/+:Vangl2Lp/+ kidneys compared with wild type littermates. During kidney injury induced by folic acid, a reduction in levels of Celsr1, normally expressed on the apical surface of proximal tubules, was seen in both the acute and fibrotic phases of this model. This data highlights that Celsr1 and the interaction between Celsr1 and Vangl2 are critical for normal kidney development and PCP proteins have a potential role in the progression of renal disease.

Cystic kidney diseases are a fascinating cluster of discrete conditions and an important, common cause of established renal failure. Both isolated and syndromic inherited cystic kidney diseases are known to be linked by their pathogenesis involving ciliary dysfunction. Interestingly to date, all mutated genes which have been related to cystic kidney disease, encode proteins which are located on cilia, the basal body or centrosomes and are required for ciliary function. To date, over 50 causal genes have been identified and are capable of causing additional disease phenotypes, such as neurological disorders and blindness, often of variable severity. Understanding this clinical heterogeneity may considerably guide appropriate genetic counselling and screening of patients for relevant complications. Zebrafish are a well-recognised animal model, their advantages of: transparency; conserved genome; representative kidney and rapid external development; make them useful for studying organogenesis in the context of disease. Furthermore the ability to perform combined gene knockdown in zebrafish, to study the effect of oliogenicity, which was proposed to influence clinical phenotypes in cystic kidney disease related ciliopathies, was of interest. Using zebrafish models, this work studied the impact of four key genes, independently and in combination: ahi1, cc2d2a, nphp6 and mks3 on the development of cystic kidney disease and ciliopathy phenotypes, to resemble the human diseases nephronophthisis (NPHP), Joubert syndrome (JBTS) and Meckel Gruber syndrome, (MKS). A frequent finding in zebrafish morphants was a reduction in the number of cilia, which was usually associated with abnormal development of left-right body patterning and cystic kidney disease. Additionally, combined gene knockdown of: nphp6 and cc2d2a; ahi1 and cc2d2a; ahi1 and nphp6 was associated with a synergistic increase in disease phenotypes, suggesting an interaction between these genes. In conclusion, zebrafish are a powerful developmental model to study and ideally improve understanding of cystic kidney disease related ciliopathies.