Chronic kidney disease (CKD) is a multifaceted health problem with both physical and psychological manifestations. Increased symptom burden is associated with higher risk of mortality, decreased treatment adherence, and impaired quality of life. Despite the recognition of the importance of symptoms, the symptoms and mental health of individuals with CKD remain poorly understood in terms of their measurement, epidemiology and associated service use. The chapters in this dissertation aim to inform these knowledge gaps. Chapter 2 focusses on the symptom burden of patients receiving maintenance hemodialysis treatment and uses exploratory analyses to identify intra-dialytic symptom clusters associated with prolonged dialysis treatment recovery time. Chapters 3 and 4 are population-based studies examining mental health and addictions service utilization in patients with CKD using administrative data in Ontario, Canada. Chapter 3 is a cross-sectional study evaluating the prevalence of individuals with a history of mental health and addiction service use by levels of kidney function. Chapter 4 is a retrospective cohort study evaluating the rates of mental health and addiction service use over time in patients with CKD. Together, these chapters provide further understanding of how symptoms of dialysis and mental health and addiction service use may be measured in this patient population. They also inform considerations for the design of future symptom management and system-level mental health strategies in CKD. / Thesis / Doctor of Philosophy (PhD)

Renibacterium salmoninarum, the etiological agent of bacterial kidney disease (BKD) of salmonid fish, is a pathogen of great concern among fisheries and the aquaculture industry worldwide. Previous investigations have indicated the pathogenesis of BKD is complex. It is a chronic, multisystemic, granulomatous disease with a number of potential immunomodulatory effects on the host. Given the current limitations for treatment and control of BKD, it is imperative that the pursuit of development of methods of prevention, namely management strategies and vaccination, be continued. To do so, the immunology of BKD must be elucidated in order to better understand and manipulate the associated immune responses to our advantage. This dissertation is composed of four chapters which relate to BKD and the associated immune responses of three species of susceptible salmonid fish as follows: Exogenous stress factors, through stress-induced immunosuppression, have been shown to influence BKD development in cultured salmonids. Chapter 1 examines the effects of two environmental stressors common to fish culture, overcrowding and overfeeding, as they affect BKD development and R. salmoninarumantigen prevalence among juvenile chinook salmon (Oncorhynchus tshawytscha) Immunomodulatory interaction between pathogen and host in BKD is widely reported and merits further investigation. Particularly, the immunological parameters affected and the role of the extracellular protein (ECP) of R. salmoninarum are of interest. Chapter 2 examines the in vivo immune response of rainbow trout (Oncorhynchus mykiss) following exposure to the ECP in terms of both humoral and cell-mediated immunological parameters, including the immune response against another bacterial pathogen. Chapter 3 addresses the in vitro effects of the ECP upon specific splenic immunocyte functions, phagocytosis and respiratory burst activity, in brook trout (Salvelinus fontinalis). The immune-complex mediated hypersensitivity reported to occur with BKD has considerable ramifications for control measures involving immunostimulation via antigen exposure. Further investigation is warranted to discern the significance and consistency of immunological hypersensivity in BKD pathogenesis. Chapter 4 examines the renal lesions, including immunopathologic changes and indications of immune-mediated disease, of brook trout exposed to R. salmoninarum. / Ph. D.

Chronic Kidney Disease (CKD) is a progressive condition that in the majority of cases leads to End Stage Renal Failure (ESRD) and the need for dialysis, with the only cure being renal transplant. CKD affects both adults and children; however the underlying causes of the disease are different. CKD in adults is most commonly secondary to diabetes and/or hypertension while CKD in children is usually caused by congenital structural abnormalities that result directly in renal dysfunction. There have been numerous reports of inflammatory and immunological disturbances in adult CKD that involve both the cellular and humoral immune systems. Consequences of these include an increased rate of cardiovascular disease (CVD), decreased response to vaccinations, as well as increased rates of infection, anaemia and malnutrition. Children with CKD display many of the clinical complications seen in adult kidney disease that are associated with inflammatory and immunological changes. In adults however, many of the primary conditions associated with CKD are inherently pro-inflammatory; therefore it is not clear whether the inflammatory changes observed in adults with CKD are due to pre-existing inflammatory conditions, renal disease per se or a combination of both. The majority of CKD in children is caused by conditions that are not inflammatory in nature. This presents a unique opportunity to study the inflammatory consequences of CKD alone, without the added complication of underlying inflammatory disorders. Despite this, there has been little investigation of the inflammatory and immunological status of children with CKD. Some very recent studies have shown that children with CKD have an increased systemic inflammatory state[1-3], however the nature of these immunological and inflammatory changes remains poorly defined. Identification of the specific inflammatory processes that occur in CKD may provide new treatment targets and the opportunity to develop urgently needed new therapies. The purpose of this thesis is to investigate the presence of immunological changes associated with inflammation in children with CKD. This is the first study to include children with very mild disease, and the significant changes that are present in the early stages of the disease are of particular note. I have shown that CKD in children is an intrinsically inflammatory condition, with increased accumulation of markers of oxidative stress and production of pro-inflammatory cytokines. The inflammatory markers identified in this study may be applied as a foundation for more sensitive diagnostic markers of disease progression as well as provide a basis for novel treatment strategies in this group of patients. Early identification of increased inflammation is a prerequisite for the application of preventive strategies. In addition, a better understanding of the level and mechanisms of systemic inflammation in children with CKD may enable a more accurate assessment of their risk of other inflammatory conditions such as CVD, anaemia, muscle wasting, and malnutrition. Future research that specifically focuses on the reasons and mechanisms for different rates of disease progression may emerge as a result of this study. Importantly, the findings of this study may have implications in the long term treatment of disease and may allow identification of new treatment strategies to achieve better patient outcomes. The outcomes of the study are: • Better definition of inflammatory profiles in paediatric CKD and correlation with disease severity and progression, which should contribute to improved management strategies. • Identification of new treatment targets to reduce the damage caused by chronic systemic inflammation. • Mechanistic understanding of the relationship of the inflammatory profile in regard to source leucocytes or other contributing cell types. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1330366 / Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2008

Chronic Kidney Disease (CKD) is a progressive condition that in the majority of cases leads to End Stage Renal Failure (ESRD) and the need for dialysis, with the only cure being renal transplant. CKD affects both adults and children; however the underlying causes of the disease are different. CKD in adults is most commonly secondary to diabetes and/or hypertension while CKD in children is usually caused by congenital structural abnormalities that result directly in renal dysfunction. There have been numerous reports of inflammatory and immunological disturbances in adult CKD that involve both the cellular and humoral immune systems. Consequences of these include an increased rate of cardiovascular disease (CVD), decreased response to vaccinations, as well as increased rates of infection, anaemia and malnutrition. Children with CKD display many of the clinical complications seen in adult kidney disease that are associated with inflammatory and immunological changes. In adults however, many of the primary conditions associated with CKD are inherently pro-inflammatory; therefore it is not clear whether the inflammatory changes observed in adults with CKD are due to pre-existing inflammatory conditions, renal disease per se or a combination of both. The majority of CKD in children is caused by conditions that are not inflammatory in nature. This presents a unique opportunity to study the inflammatory consequences of CKD alone, without the added complication of underlying inflammatory disorders. Despite this, there has been little investigation of the inflammatory and immunological status of children with CKD. Some very recent studies have shown that children with CKD have an increased systemic inflammatory state[1-3], however the nature of these immunological and inflammatory changes remains poorly defined. Identification of the specific inflammatory processes that occur in CKD may provide new treatment targets and the opportunity to develop urgently needed new therapies. The purpose of this thesis is to investigate the presence of immunological changes associated with inflammation in children with CKD. This is the first study to include children with very mild disease, and the significant changes that are present in the early stages of the disease are of particular note. I have shown that CKD in children is an intrinsically inflammatory condition, with increased accumulation of markers of oxidative stress and production of pro-inflammatory cytokines. The inflammatory markers identified in this study may be applied as a foundation for more sensitive diagnostic markers of disease progression as well as provide a basis for novel treatment strategies in this group of patients. Early identification of increased inflammation is a prerequisite for the application of preventive strategies. In addition, a better understanding of the level and mechanisms of systemic inflammation in children with CKD may enable a more accurate assessment of their risk of other inflammatory conditions such as CVD, anaemia, muscle wasting, and malnutrition. Future research that specifically focuses on the reasons and mechanisms for different rates of disease progression may emerge as a result of this study. Importantly, the findings of this study may have implications in the long term treatment of disease and may allow identification of new treatment strategies to achieve better patient outcomes. The outcomes of the study are: • Better definition of inflammatory profiles in paediatric CKD and correlation with disease severity and progression, which should contribute to improved management strategies. • Identification of new treatment targets to reduce the damage caused by chronic systemic inflammation. • Mechanistic understanding of the relationship of the inflammatory profile in regard to source leucocytes or other contributing cell types. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1330366 / Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2008

Proliferative kidney disease (PKD) poses a high financial burden upon the freshwater salmonid aquaculture industry of Europe and North America. The alternate hosts of the causative agent, Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea), have been identified as freshwater bryozoans (Bryozoa: Phylactolaemata) within which spores capable of infecting salmonid fish develop. Currently, control of PKD relies upon complex management practices, with no licensed prophylaxis or treatment available. Assessment of the nutritional preferences of phylactolaemate bryozoans allowed development of an optimised laboratory culture system. Following laboratory maintenance, bryozoans collected from PKD-endemic sites were found to be infected with the malacosporean parasites T. bryosalmonae and Buddenbrockia plumatellae. Subsequent parasitic development was observed using light-, electron- and confocal-microscopy techniques. Methods of challenging rainbow trout with T. bryosalmonae spores were developed, with the minimum infective dose established. The presence of Thomsen-Friedenreich and Tn epitopes within the parasite was investigated, and experimental vaccine preparations based on either these specificities or T. bryosalmonae-infected bryozoans were efficacy tested in rainbow trout. In addition, salinomycin and amprolium were tested as prospective chemotherapeutants for PKD. Further insights into the development and subsequent release of malacosporean spores within their invertebrate hosts have been revealed. Long-term maintenance of T. bryosalmonae allowed controlled infection of rainbow trout previously vaccinated with experimental preparations. Findings of the project could potentially be utilised in future research into the development of control methods for PKD.

Master of Science / Department of Clinical Sciences / Gregory F. Grauer / Chronic kidney disease (CKD) is a common cause of morbidity and mortality in cats. The purpose of this study was to investigate the effects of Chinese rhubarb (Rheum officinale) supplementation on the progression of feline CKD. Cats with stable IRIS stage II or III CKD and without certain comorbidities were included in the study. Cats were randomly divided into 3 treatment groups and administered Chinese rhubarb extract (Group 1, Rubenal®, Vetoquinol, Forth Worth, TX; 75 mg tablet by mouth every 12 h), benazepril as a positive control (Group 2, 0.5 mg/kg by mouth every 24 h), or both (Group 3). Cats were fed a commercial renal specific diet and enteric phosphate binder as appropriate. Body weight, laboratory data, and blood pressure were recorded every 3 months. Variables between groups at enrollment and within groups over visits were compared with ANOVA and repeated measures ANOVA, respectively. A treatment by visit interaction term was included in all repeated measures models. Significance was set at p ≤ 0.05. Except for body weight there was no significant differences between treatment groups at enrollment. There was no significant change in body weight, hematocrit (Hct), UPC, serum creatinine, or systemic blood pressure over time as compared to baseline within any group. There was no significant difference between groups over time in regards to change in body weight, Hct, UPC, serum creatinine, or systemic blood pressure. The treatment by time interaction was non-significant in all models. Based on easily measured clinical parameters, this study failed to detect a significant difference in cats administered a Chinese rhubarb supplement, benazepril, or both.

Muscle wasting and increased proteolysis is a major problem in chronic kidney disease (CKD). Exercise is potentially beneficial, but has been under-investigated in pre-dialysis CKD and could theoretically worsen acidosis through exercise-induced lactic acid generation. We therefore investigated effects of 6 months walking exercise with and without additional alkali therapy. 40 patients were recruited (23 male and 17 female, median age 58, range 20-83, mean eGFR±SEM 25.7±1.2ml/min/1.73m2). 20 undertook walking exercise at a Borg Rating of Perceived Exertion Rate (RPE) of 12-14 for at least 30 minutes, 5 times a week. The other 20 continued with normal physical activity (non-exercising controls). In addition to standard oral bicarbonate therapy (STD), 10 patients in each group were randomised to receive additional bicarbonate (XS). Blood and vastus lateralis muscle biopsies were drawn at baseline, one and six months. 18 exercisers (including 8 in XS group) and 14 controls (6 in XS group) completed the 6 month study. Exercise tolerance increased after 1 and 6 months in the exercisers, but not the controls, accompanied by a reduced acute lactate response in the XS, but not the STD exercising group. After 6 months of exercise, 9 intramuscular free amino acids showed striking depletion in the STD, but not XS bicarbonate group. This suggests an inhibition of active amino acid transporters, possibly the SNAT2 transporters that are inhibited by acidosis. Studies with cultured myotubes identified glucocorticoid as a possible mediator of acid s inhibitory effect on SNAT2. The preservation of amino acid concentrations in the XS exercising group was accompanied by strong suppression of ubiquitin E3-ligases MuRF-1 and MAFbx which activate proteolysis through the ubiquitin-proteasome pathway. However, other anabolic indicators (Protein Kinase B activation and suppression of the 14kDa actin fragment) were unaffected in the exercising XS group. Possibly because of this, overall suppression of myofibrillar proteolysis (3-methyl histidine excretion) and increased lean body mass (DEXA) were not observed in the exercising patients. As XS alkali had no effect in non-exercisers, it is concluded that alkali effects in the exercisers arose by countering exercise-induced acidosis. Sulphuric acid produced from the catabolism of sulphur-containing amino acids ingested in the diet is the main contributor to the daily titratable acid load and hence acidosis in CKD. In these patients the amount of sulphate excreted in urine over 24h varied widely between individuals. This directly correlated with 3-methyl histidine excretion suggesting that sulphate excretion may be a better clinical indicator of acidotic patients at long-term risk of cachexia than conventional measures such as venous bicarbonate. Studies with cultured myotubes confirmed that skeletal muscle is a source of sulphuric acid and showed that production of this acid is partly suppressed by L-Glutamine a potential novel way to control acidosis in CKD.

Master of Science / Biomedical Sciences / Gregory F. Grauer / Chronic kidney disease (CKD) is a potentially life-threatening disease that reportedly affects 10% of dogs and 30% of cats over the age of 15. There is no cure available for CKD, but medical management is available for patients with this disease. Research has focused on earlier detection of CKD with the goal of instituting medical management and monitoring as early in the disease course as possible. Symmetric dimethylarginine (SDMA) has recently emerged as a novel renal excretory biomarker that may aid in early detection of CKD in cats and dogs. SDMA is non-protein bound and is freely filtered by the glomerulus, is not secreted or reabsorbed, and has greater than 90% excretion by the kidneys, making it a potential target for measurement of glomerular filtration rate (GFR). Previous studies have demonstrated a close parallel between SDMA and serum creatinine (sCr), which is the currently favored serum biomarker for assessment of GFR. Research has also demonstrated a correlation between SDMA and GFR. Serum concentrations of SDMA increase above normal when GFR is decreased by 25-40%; much earlier than the 75% decrease in GFR typically required for sCr to increase above its reference interval. The studies reported here demonstrate a potential use for the SDMA:sCr ratio as a predictor of volume responsive azotemia. Furthermore, longitudinal assessment of older dogs and cats for early detection of CKD showed that SDMA was a more sensitive indicator of CKD than sCr. The evaluation of SDMA reported in this thesis presents a novel perspective on SDMA and its use clinically.

<p> Intestinal phosphorus absorption is a key contributor to the body phosphorus pool, but much is unknown regarding physiological adaptations in intestinal phosphorus absorption that occur in vivo. We sought to measure changes in intestinal phosphorus absorption efficiency and phosphorus balance in adolescent females and in rats in response to several factors, using physiologically relevant assessment approaches including whole-body phosphorus balance techniques and <i>in situ</i> ligated intestinal loop absorption methods.</p> <p> We first assessed phosphorus balance and net phosphorus absorption in female adolescents from a controlled crossover study with two levels of calcium intake. Despite an increased calcium intake of 600 mg/day, there was no change in phosphorus balance, nor a significant change in net phosphorus absorption.</p> <p> Next, we measured intestinal phosphorus absorption efficiency with the <i>in situ</i> ligated loop method in healthy Sprague Dawley rats as well as the Cy/+ rat model of progressive kidney disease. We found 10-week-old healthy rats had a small but higher absorption efficiency of phosphorus compared to 20- and 30-week-old rats, while 20-week Cy/+ rats had higher absorption efficiency than 30-week-old. Each of these results corresponded to net phosphorus absorption from balance as well as the concentration of 1,25-dihydroxyvitamin D3. In healthy rats, there was no effect of altering the level of phosphorus in the diet on absorption efficiency. In Cy/+ rats, kidney disease produced a small <i>increase</i> in absorption efficiency, contrary to the predicted decrease that would occur with lower 1,25-dihydroxyvitamin D3 observed in CKD. Gene expression of the major intestinal phosphate transporter, NaPi-2b, largely followed absorption patterns.</p> <p> The utility of the Cy/+ model is limited to males as females do not begin to show signs of progressive kidney decline until a much older age. Therefore, we sought to test whether ovariectomy would accelerate kidney disease in Cy/+ females, with the aim of establishing a postmenopausal model of progressive kidney disease. Our results show that kidney disease is not accelerated by ovariectomy in this rat strain, as measured by kidney weight and biochemistries including blood urea nitrogen, creatinine, creatinine clearance, and plasma phosphorus and calcium.</p> <p> Our results utilizing <i>in situ</i> absorption measures as well as net absorption of phosphorus suggest that some of the factors that are understood to influence the intestinal absorption of phosphorus do not have a significant influence in a physiological context.</p>

The incidence and mortality from cardiovascular disease (CVD) in patients with chronic kidney disease (CKD) far exceeds that seen in the general population. Whilst a number of risk factors and associations have been identified in patients with CKD that may contribute to the increased risk of CVD, our understanding of the underlying pathophysiology remains poor. It has previously been reported that uraemic animals sustain larger myocardial infarcts and that this ‘reduced ischaemia tolerance’ may in part explain the excess mortality from CVD seen in CKD patients. The aim of this work was to establish an in vivo model of uraemic myocardial infarction in order to further explore the pathophysiology of uraemic CVD with particular focus on ameliorating myocardial ischaemia-reperfusion injury using ischaemic and pharmacological preconditioning. An increase in myocardial infarct size was demonstrated in the sub-total nephrectomy model of chronic uraemia, confirming previous reports in the literature. However, infarct size was not found to be increased in adenine diet induced renal failure. In addition, it was demonstrated for the first time, that the techniques of ischaemic preconditioning (IPC) and remote ischaemic preconditioning (RIPC) are both efficacious and not attenuated by chronic uraemia induced by sub-total nephrectomy or adenine diet (IPC only). Investigations were undertaken using an agent (a HIF stabiliser, FG4497) to induce pharmacological preconditioning in both animals with renal insufficiency and those without. These studies demonstrate that stabilisation of hypoxia inducible factor (HIF) may be a promising strategy to induce pharmacological preconditioning. It is hoped that this work may lay the foundations for future investigations to determine why sub-totally nephrectomised rats have larger infarcts whilst those with adenine induced renal failure, with a substantially greater degree of renal dysfunction, do not. Moreover, it is hoped that; by demonstrating that uraemia 3 does not prevent or attenuate the myocardial protection afforded by ischaemic preconditioning, the recruitment of patients with CKD will be encouraged to clinical trials of both ischaemic preconditioning and other therapies to limit myocardial infarction.