231 |
A Versatile High Throughput Microfabricated Platform to Study Cancer Metastasis and Kidney DiseaseBhattacharya, Smiti January 2023 (has links)
Precision medicine involves a personalized approach to healthcare acknowledging an individual-to-individual variability in genetics, environment, and lifestyle. Research in precision medicine can be pulled from basic, clinical or epidemiological sciences from which imaging, omics, or other types of data can be mined to contribute to the ‘information commons’ from which patient-specific patterns are drawn. Advancement in basic sciences that focus on imaging and other high content information processing for precision medicine is of particular importance in fields like oncology and nephrology where, diseases like focal segmented glomerular sclerosis have neither seen drug development in the past two decades, nor have an affirmative treatment plan. One reason is the lack of high-content high-throughput platforms for drug testing with a physiologically appropriate microenvironment.
This work aims to build a high-content platform for podocyte-based drug discovery. Having demonstrated that cells in patterns demonstrate a phenotypic change representative of the in vivo condition, we first start by building a robust 96-well plate with our microfabricated platform as its base. We demonstrate a relevant increase in expression of podocyte specific proteins like synaptopodin in our patterned podocytes along with a decrease in cell-to-cell variability when compared with their unpatterned counterparts. Next, we demonstrate the use of our platform as a tool for drug discovery by showing that we achieve a reproducible actin-based dose response curve using human podocyte cell lines, something that has never been done to our knowledge. We see that our platform pushes immortalized podocytes towards cell cycle arrest at a much earlier timepoint during differentiation with improved functional performance metrics, such as lower motility and increased cytoskeletal segregation. We show that our platform may be able to extend its versatility by synergizing the effects of substrate shape and stiffness, and we show a potential application in studying the effect of this platform on the expression of Yes associated protein (YAP).
We demonstrate the flexibility of this platform using another case study, this time with cancer cells. It is well known that the progression of neoplastic cells to metastasis is a major contributing factor to poor prognosis. The metastatic cascade involves invasion and migration coupled by angiogenesis and intravasation. The subsequent cells that survive circulation and attach to the endothelium extravasate and colonize in a distal location. Current techniques, such as Transwell and scratch assays that attempt to quantify metastatic potential are difficult to scale and consequently may be challenging to use in large-scale drug testing. We show that using our platform, we are able to rapidly quantify the metastatic potential of cancer cells in situ with high sensitivity, independent of cell seeding density. By changing the dimensions of our microfabricated patterns, we are able to vary the mechanical resistance that the cell experiences traversing and use this to mimic cell invasion across different microenvironments. Importantly, we show that we can quantify the effect of the metastatic potential in response to a pharmacological intervention and thus demonstrate that we can use this platform for drug testing.
In conclusion, we present a novel multifaceted platform and demonstrate its versatility with two different applications. In the context of drug discovery, we show that the platform serves as a superior model for podocyte injury. The reproducible Puromycin aminonucleocide (PAN) actin-based dose response curves obtained using this platform, opens avenues to investigate the effect of various targeted therapies for podocyte-based kidney diseases. In the context of screening for metastatic potential of cancer cells, we show that our platform exhibits a superior sensitivity to existing screening techniques. Additionally, the potential of using a patient’s own cells in the future for either application presents exciting avenues for precision medicine.
|
232 |
Science principles - care of the nephrotic patientLetteri, Mary January 1964 (has links)
Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The purpose of this study was the identification of
science principles underlying the care of a patient with
glomerulonephritis and the nephrotic syndrome and the deduction
of appropriate nursing activities from these principles.
The four sciences of anatomy, physiology, pathology and
biochemistry were included in this study. / 2999-01-01
|
233 |
The renal sympathetic nerves : implications for vascular remodelling in the SHR kidneyShweta, Amany, 1971- January 2001 (has links)
Abstract not available
|
234 |
Carbohydrate metabolism in chronic renal and liver disease潘建基, Pun, Kin-kee. January 1986 (has links)
published_or_final_version / Medicine / Master / Doctor of Medicine
|
235 |
The impact of prenatal glucocorticoid exposure on the ovine kidneyMeyer, Amanda Jane January 2006 (has links)
[Truncated abstract] In obstetric practice, pregnant women at risk of pre-term delivery between 24 and 34 weeks of gestation are administered synthetic glucocorticoids (betamethasone or dexamethasone) to induce fetal organ maturation. During this gestational period, the fetal kidney is undergoing a phase of rapid organogenesis with an increase in renal growth and active nephrogenesis occurring. The studies comprising this thesis examine the effects of prenatal betamethasone exposure on the fetal and adult ovine kidney. The central hypothesis of these studies was that exposure of the fetal kidney to betamethasone in late gestation would change renal structure and induce long-term alterations in the expression of glucocorticoid-sensitive genes and proteins. In the fetal studies, pregnant Merino ewes bearing single fetuses received single or repeated-weekly intra-muscular (i.m.) injections of betamethasone (0.5 mg/kg body weight) or saline commencing on day 104 of gestation (term is 150 days). Kidneys were collected from fetuses at 109, 116, 121 and 146 days of gestation (d). Using gold standard unbiased stereological techniques, the physical disector/fractionator method, total glomerular (nephron) number and glomerular volume were determined in 146 d fetal kidneys exposed to repeated maternal saline or betamethasone administration. In the adult study, kidneys were collected from 3.5-year-old sheep that had been exposed to ... In this thesis I have demonstrated that renal growth restriction as a result of betamethasone exposure is associated with a reduction in fetal nephron endowment. Although betamethasone does not appear to consistently alter nephron number or glomerular size, it may indirectly affect total nephron endowment through effects on renal growth. I have also provided evidence which suggests that lategestation betamethasone exposure in sheep does not program permanent alterations in the renal expression of genes or proteins involved in glucocorticoid hormone action or components of the renin-angiotensin system. Therefore, exposure of the fetal kidney to betamethasone during nephrogenesis may alter renal structure if kidney growth is perturbed; however, there are no persistent alterations in the expression of glucocorticoid-sensitive genes. These findings are consistent with the preservation of normal basal blood pressure in the adult sheep I studied and with the limited results from human studies of late-gestation maternal glucocorticoid administration.
|
236 |
Investigations of influenza vaccination in kidney & lung transplant populationsBergeron, Amber Dawne. January 2010 (has links)
Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Experimental Medicine, Department of Medicine. Title from pdf file main screen (viewed on April 24 2010). Includes bibliographical references.
|
237 |
Semen analysis of renal transplant patients undergoing immunosuppressive treatmentMoodley, Neville Sivanandan January 2017 (has links)
Submitted in partial fulfillment of the requirements for the degree of Master of Health Sciences in Clinical Technology, Durban University of Technology, Durban, South Africa, 2017. / Introduction
The prevalence of infertility is increasing at an alarming rate globally. Many couples are afflicted with infertility due to an array of diseases, trauma and psychological stresses. Renal disease is one such pathophysiological condition which is increasing amongst the younger age group. Often the progression of chronic renal disease leads to end stage renal failure that requires a renal transplantation. Post renal transplant, immunosuppressive agents are routinely prescribed to prevent allograft rejection. Immunosuppressive agents are potent drugs that can have deleterious side effects on semen parameters. However, the effects of the immunosuppressive agents on semen parameters in the literature are unclear and require further investigation. It is, therefore, important to assess the effects of immunosuppressive agents on semen, especially the three vital aspects of sperm concentration, motility and morphology which form the basis of male reproduction.
Aims and Objectives of study
This was a prospective observational study evaluating the effects of different immunosuppressive regimens on sperm parameters in post renal transplant male patients. The main aspects of semen parameters such as sperm concentration, motility and morphology that determine reproductive potential were assessed in the study patients and compared to the gold standard of semen analysis according to the World Health Organisation (WHO) reference values.
Methodology
Thirty-four renal transplant patients were recruited from the databases of both private nephrologists in the greater Durban area and the academic renal unit at Inkosi Albert Luthuli Central Hospital. Following bioethical approval and informed consent, patients were required to produce a semen sample by masturbation. A questionnaire documenting the patient’s lifestyle, aetiology of renal disease, transplant date and immunosuppressive duration and regimen were recorded. The semen samples were analysed comprehensively according to the protocol on semen analysis recommended by the WHO. This included the macroscopic investigation (volume, appearance, colour, viscosity, liquefaction time and pH) and microscopic evaluation (sperm concentration, total motility, morphology, IgG/IgA and vitality). Sperm concentration, total motility, morphology and vitality were examined and recorded in duplicate to strengthen the validity of the results. A biostatistician analysed the data and determined the statistical analysis. Descriptive statistics determined values of semen parameters in renal transplanted males and in each race demographic. The one sample t-test analysed the statistical significance between the mean study values and the WHO reference values. The effect of the immunosuppressive agent on semen parameters was determined using multiple linear regressions whilst ROC analysis determined the sensitivity and specificity of sperm concentration, total motility and morphology in predicting pregnancy from the patients that fathered children post renal transplant.
Results
The mean sperm concentration and morphology in the study patients were 14.0 mill/ml (95% Confidence Interval (CI) 10.2 – 17.7) and 3.3% (95% CI 2.7 – 3.9), respectively. Although values obtained were minimally lower than the WHO reference values, these results were within the 95% CI of the WHO guidelines.
Motility evaluation revealed higher values of 43.2% (95% CI 36.6 – 49.7). In contrast, sperm vitality was considerably decreased, 47.5% (95% CI 40.6 – 54.4). All semen parameters exhibited no statistical significance (one sample t-test) when analysed against the WHO reference values except for sperm morphology, (p = 0.025; p< 0.05) which showed decreased morphology irrespective of immunosuppressive regimen. Semen volume 1.7 ml (95% CI 1.3 – 2.0) and pH 7.7 (95% CI 7.6 – 7.9) were both within the WHO guidelines. Descriptive statistics according to racial demographics showed no differences in semen values. An almost perfect linear relationship existed between total sperm motility and vitality (r = 0.967). Multiple linear regressions of duration and dosages of immunosuppressive drugs tacrolimus and mycophenolate mofetil, could not predict the effect of the immunosuppressive agents on sperm concentration, total motility and morphology. There was a significant difference in morphology between those with and without children post renal transplant. Those with children post renal transplant exhibited a higher morphology value, (p = 0.001; p< 0.05). Sensitivity and specificity analysis of the patients with children post renal transplant concluded that morphology is the most optimal indicator and predictor of pregnancy (AUC = 0.854). Tacrolimus was the common immunosuppressive agent used in the four patients that fathered children. This was more evident in patients that underwent therapy with Sirolimus followed by Cyclosporin A (CsA) and changed to Tacrolimus as the last immunosuppressive agent used for maintenance therapy.
Conclusion
The ability to procreate in renal transplanted males has become increasingly difficult and emotionally challenging. In this study sperm concentration and morphology of renal transplanted males exhibited parameters similar to the general fertile population. Total motility possessed a higher range of values in contrast to sperm vitality which showed a significant decrease from the WHO reference values. The effect of immunosuppressive treatment on semen parameters could not be clearly defined due to the number of immunosuppressive regimens that patients were subjected to intermittently resulting in small sample sizes within each immunosuppressive regimen grouping. The majority of patients underwent a triple maintenance therapy of tacrolimus, MMF and prednisone. The dosage and duration of these tacrolimus and MMF was inconclusive in determining a beneficial or detrimental relationship on semen parameters. Morphology was shown to be the most significant indicator in predicting pregnancy in patients that fathered children. Tacrolimus was a common immunosuppressive agent used in the majority of patients that fathered children. It may have protective effects on sperm parameters as shown in patients that fathered children. This was a study with a small sample size and further investigations are required in a larger cohort of patients to assess individualized effects of the different immunosuppressive agents on sperm parameters. / M
|
238 |
Seeking certainty in an uncertain world : psychosocial aspects of renal replacement therapies in children and adolescentsPruefe, Jenny Maria January 2013 (has links)
No description available.
|
239 |
Development of Therapies to Treat Polycystic Kidney DiseaseFlaig, Stephanie Marge 06 March 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Polycystic kidney diseases (PKD) are genetic disorders characterized by fluid filled cysts in the kidney tubules and liver bile ducts. There are two forms of PKD, autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD). The focus of the studies in this thesis has been on ADPKD. The disease progresses slowly and the fluid-filled cysts grow in size due to increased rates of cell proliferation and fluid secretion into the cyst lumen. The expanding cysts compromise the normal kidney function and result in a decrease of renal
function to the point of end-stage renal failure in midlife. Cyst enlargement is due, at least in part, to chloride secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. Currently therapy is limited to renal cyst aspiration, dialysis, and eventually renal transplantation after organ failure, thus it has critical to determine possible drug therapies for the treatment of PKD.
Previous studies showed that cyst fluid caused a secretory response in cells lining the cysts. We hypothesized that once the cyst have expanded and become so large that they burst or leak, which could also occur due to renal injury or aging, the cyst fluid may stimulate additional cyst growth. Lysophosphatidic Acid (LPA) was determined to be the active component of human cyst fluid, and we investigated the LPA stimulated signaling pathway.
Our data suggest that the LPA stimulates chloride and fluid secretion by a combination of CFTR and Calcium-Activated chloride channels (CaCC) and that the two channels may functionally be linked to each other. The secretion is not occurring through a cAMP stimulated pathway, and it is possible that TMEM16A, a CaCC, plays a larger role than previously expected.
Previous studies demonstrated that PPARγ agonists, insulin sensitizing drugs used to treat diabetes, inhibit chloride secretion by the collecting duct principal cells by decreasing CFTR synthesis. It was logical therefore to considered PPARγ agonists as long-term treatment for PKD. The first preclinical studied showed that high (20 mg/kg BW) dose pioglitazone, a PPARγ agonist, inhibited cyst growth in the PCK rat model, a
slow progressing model, of PKD. To continue to look at the effects of the PPARγ agonists another preclinical study was completed, which tested if there was a class action of PPARγ agonists and if a lower dose was effective in treating the cystic burden. Using the PCK rat model, and another PPARγ agonist, rosiglitazone, a 24 week study was completed using 3 doses (4, 0.4, and 0.04 mg/kg BW). 4 mg/kg BW rosiglitazone is
analogous to 20 mg/kg BW pioglitazone. The data indicated that the rosiglitazone is effective in lowering the cystic burden, and importantly the low dose proved to be
effective. An additional rat model, the W-WPK rapidly progressing model was used to determine efficacy across multiple models, and to determine if there was a way to track
the progress of the disease in a manner analogous to that used in human patients. The animals were treated with pioglitazone using 2 doses (2 and 20 mg/kg BW), and were
imaged using CT scans to track the progress of the disease. The data suggest that pioglitazone was not as effective in the W-WPK rat model as it was the PCK rat model. There was a trend however, that low dose PPARγ agonist was as effective ad high dose. Even more important, the CT scans proved to be an effective way to track the progress of the disease in animal models.
|
240 |
The impact of dialysis therapy on metabolic syndrome traits at the Groote Schuur HospitalMaree, Marilyn Jacqueline 03 March 2015 (has links)
Submitted in fulfillment of the requirements for Masters in Technology: Clinical Technology Durban University of Technology, 2014. / Background
The metabolic syndrome (MS) is a clustering of cardiovascular (CV) risk factors and is noted to be increasing globally. Several studies have shown a link between the MS, chronic kidney disease (CKD) and end-stage renal disease (ESRD) possibly through a process of inflammation. Dialysis therapy may increase inflammation and could worsen MS and increase CV risk and diseases in ESRD patients. ESRD has been associated with increased CV disease in dialysis patients. Although there have been several reports on the prevalence of MS from the general population as well as from other specific groups, there are no known studies in South Africa on the prevalence of MS in ESRD patients on chronic dialysis therapy. The prevalence and risk factors for CV diseases are also currently unknown in the dialysis population in Cape Town.
Aim
The aim of this study was to determine the prevalence of MS in the dialysis population at Groote Schuur Hospital in Cape Town, to determine the effect of dialysis on MS and its traits and to evaluate CV risk in this patient group.
Methods
A total of 143 prevalent chronic dialysis patients who consented were used for this study. Demographic and relevant clinical details including systolic and diastolic blood pressures, waist and hip circumference and body mass index were obtained from all patients. Blood was drawn in the fasting state for assessment of full lipogram, glucose, ferritin, iron, calcium and phosphate. The metabolic syndrome was defined using the Adult Treatment Panel III (ATPIII) criteria. To determine the impact of dialysis on MS and its traits in our patients, only incident (new) patients starting dialysis were followed up for assessment of MS traits at timed intervals (at baseline, at 6 months and at 12 months) following initiation of chronic dialysis. To evaluate CV risk in this study, common traditional CV risk factors were assessed and were stratified according to number of risk factors as low ( ≤ 1), moderate (2 – 4) or high ( ≥ 4). Relevant statistical methods were used for analysis.
Results
Of the 143 patients in the study, 67.8% were on haemodialysis (HD) and 32.2% were on peritoneal dialysis (PD). The mean age of all the patients was 38.5 ± 10.4 years. The MS was present in 37.1% of all patients (PD – 52.2%, HD 29.9%; p = 0.015) and the frequency of increased waist circumference and hypertriglyceridaemia were significantly higher in PD patients than HD patients (p < 0.0001 and p = 0.006 respectively). Hypertension was the most prevalent MS trait in all the patients (89.5%) and was also the most prevalent trait in males (92.4%), females (85.9%) and in HD and PD patients (91.3% and 88.7% respectively). The frequency of CV risk was 3.5, 75.5 and 21.0% respectively for low, moderate and high CV risk and there was no difference in CV risk in HD and PD patients. High CV risk correlated with body mass index (BMI), increased waist circumference (WC), hyperphosphataemia, raised calcium – phosphate product, raised parathyroid hormone (PTH) and elevated C-reactive protein (p < 0.05). There was no significant change in MS prevalence or prevalence of MS traits in patients who were followed up irrespective of gender or modality of dialysis (p > 0.05)
Conclusion
The prevalence of the MS is higher in dialysis patients compared to the general population in South Africa and among dialysis patients, the prevalence is higher in PD than HD patients. Patients with MS have significantly higher CV risk factors than those without MS. Although dialysis therapy appear to have no significant effects on the prevalence of the MS or its traits in this study, the increased prevalence of the MS and CV risk factors may be related to the underlying disease process associated with ESRD. There is therefore an urgent need to identify and treat dialysis patients with the MS in order to reduce CV morbidity and mortality in this group of patients. Further prolonged prospective studies are needed to clarify the impact of dialysis on the MS and its traits in the ESRD population.
|
Page generated in 0.0402 seconds