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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1191

A study to determine the quality of life and experiences for liver and kidney transplant recipients and living kidney donors in Western Australia : the economic implications

O'Driscoll, Catherine T. January 2008 (has links)
The use of quality-of-life as an outcome measure provides detailed information about the effectiveness of medical treatments than morbidity or mortality rates alone. The use of quality-of-life data in the clinical setting can inform patients regarding treatment options, treatment benefits and costs. In competing health care markets, outcome measurement is regarded as important as it is concerned with the impact of health care practice and affects health policy decisions. Doessel (1978) conducted the first Australian study on the cost-effectiveness analysis of renal replacement therapies. The study was based on Klarman, Francis & Rosenthal's (1968) the study, where the output was measured in terms of the number of life years gained from kidney transplantation, and a twenty-five percent weight was allocated in an attempt to capture quality-of-life from kidney transplantation. Doessel (1978) used two sources of data: Australian data (Disney 1974) and European data (Gurland et al. 1973; Shiel et al. 1974). The study measured life years gained, and agreed with the Klarman et al. (1974) findings that transplantation is the most effective way to increase life expectancy of persons with chronic renal disease (Butler & Doessel 1989). The outputs of the alternative treatments were not reported in monetary terms; the study focused on life years gained as the output measure. Hence the importance of this current study, which includes a cost-effectiveness analysis for cadaver liver, and living kidney transplantation for end-stage liver and kidney disease patients. Calls to respect patient autonomy and to produce patient-centered outcomes have recently brought the patient’s point of view back into the center of clinical medicine (Sullivan 2003). Survival rates indicate one measure of outcome however they do not reflect patients’ perceptions of health benefit or experiences. Noting that patients’ psychosocial effect on functioning is of more concern to them than their physical Thesis Preamble iii ability, that more accurate knowledge of patients’ conditions be measured prior to transplantation (Tarter et al. 1991). Recently researchers advocated investigating transplant patients' states of health to assess the social benefit of these expensive health care services from their perspective (Joralemon & Fujinaga 1997). The current study's mixed method, bridges the gaps in treatment outcome measurements, as the mixed method applied (Creswell 1994; Sim & Sharp 1998) prospectively measured quality-oflife, determined health utility, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). The study reported the living donors experience of the donation process, described their needs; expressed using a new psychosocial model supporting future living kidney donor's during the donation process.
1192

The immunogenetics of natural killer cell alloreactivity

Foley, Bree Amanda January 2008 (has links)
[Truncated abstract] Natural killer (NK) cell alloreactivity can be exploited in haploidentical haematopoietic stem cell transplantation (HSCT) to improve graft survival, reduce graft versus host disease and decrease leukaemic relapse. NK cells lyse cells that have reduced expression of class I HLA molecules. In an allogeneic setting, donor NK cells may be activated by the absence of donor (self) class I HLA molecules on recipient cells; the absence of self-epitopes being detected by inhibitory KIR receptors on donor NK cells. The way in which genetic polymorphism of the receptors and ligands affects NK allorecognition of missing self, has not been fully elucidated. HLA-C molecules are divided into two groups, C1 and C2, with KIR2DL1 recognising cells expressing C2 and KIR2DL2 and KIR2DL3 recognising cells expressing C1. Donor NK cells expressing KIR2DL2 or KIR2DL3 can be alloreactive towards a recipient if they lack the C1 epitope and donor NK cells expressing KIR2DL1 can be alloreactive towards a recipient if they lack the C2 epitope. KIR3DL1 recognises the Bw4 epitope present on one-third of HLA-B alleles and certain HLA-A alleles. NK cells from donors expressing KIR3DL1 can be alloreactive towards recipients whose cells lack Bw4. Mismatches of KIR related HLA epitopes does not always results in NK alloreactivity. Therefore it is not possible to reliably predict NK alloreactivity based solely on the donor's HLA type and KIR repertoire and the recipient's HLA type. ... All Bw4-positive HLA-B alleles, with the exception of HLA-B*1301 and B*1302, protected targets from lysis. HLA-A*2402 and HLA-A*3201 unequivocally protected target cells from lysis whereas HLA-A*2501 and HLA-A*2301 provided only weak protection from lysis. KIR3DL1-dependent alloreactive NK clones were identified in donors whose only Bw4 positive allele was HLA-A*2402 but not in donors whose only Bw4 positive HLA allele was HLA-B*1301 or B*1302. Finally this thesis demonstrated that an activating KIR can control NK cell alloreactivity. Donors who are C2 negative and KIR2DS1 positive had NK cells that expressed the activating receptor KIR2DS1 and were capable of lysing cells expressing the C2 epitope. More so, KIR2DS1 dependent NK clones were shown to override inhibitory signals generated by NKG2A interacting with its ligand, HLA-E. The identification of these NK clones has important implications for haploidentical HSCT in that recipient expressing all three NK epitopes, C1, C2 and Bw4 were previously thought to be resistant to alloreactive NK cells controlled by inhibitory receptors. Such patients may be amenable to haploidentical HSCT from C2 negative, KIR2DS1 positive donors. These results will improve the ability to predict NK cell alloreactivity based on a donor's HLA type and KIR repertoire and the recipient?s HLA type.
1193

A grounded theory study of the issues and challenges that impact on transplant coordinators and their practice.

Kelly, Mary Johanna. January 2008 (has links)
The purpose of this study is to identify and explore issues and challenges that impact on transplant coordinators and their practice. Such identification enhances understanding of their role, provides evidence for decision-makers to facilitate the positive aspects of the coordinators' practice, highlights their professional needs and contributions and provides baseline data for future research, education and policy development. The study used both qualitative and quantitative data. Data collection methods involved focus group interviews and Delphi surveys. Participants were coordinators who were employed on a full-time, part-time or relieving basis. Recruitment of participants was done by purposive and snowball sampling. There were 112 coordinators in the study and each was randomly assigned to the focus groups or Delphi survey phases of the research. The analysis of the focus group data together with the literature, informed the development of the first Delphi survey. The second Delphi survey was developed using the data from the focus groups, literature and the first survey. Four categories emerged from the data. The first involved 'knowledge and experience', which explored the education needs of coordinators and the issue of nursing qualification requirements. The work environment, demands and conditions, together with role attributes were discussed in the next category - 'the role'. Recipient, donor family and transplant coordinator outcomes were addressed in the 'outcomes’ category. The basic social process – building relationships - explored the relationships that coordinators have with the health team and their client groups. Four types of relationships emerged which were supportive, non-supportive, aggressive and virtual relationships. The emergent theory of the challenges that transplant coordinators face relates to the building of relationships. The theory also discovers how knowledge and experience, the role and outcomes impact on the building of these relationships in an interdependent manner. This study also emphasises that the transplant coordinators' role is complex, demanding and distinctly unique in terms of the context within which coordinators practice. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311520 / Thesis (Ph.D.) -- University of Adelaide, School of Population Health and Clinical Practice, 2008
1194

När njuren sviker : Patienters upplevelse av dialysbehandling och väntan på transplantation

Nilsson, Emily, Huasson, Jeanette January 2009 (has links)
<p>Bakgrund: Antalet patienter i behov av njurtransplantation per år är cirka 400-500, varav endast cirka 350 kommer att bli transplanterade. Bristen på organ är tydligt framträdande. I väntan på transplantation behöver patienten dialysbehandling, vilket ofta upplevs vara tidskrävande och utmattande. Sjuksköterskor bör ha kunskap om patienters upplevelser i samband med väntan på transplantation för att kunna utvecklas i sin roll som sjuksköterska och få en djupare förståelse för deras situation.</p><p>Syfte: Syftet var att beskriva kroniskt njursjuka patienters upplevelser av att leva med dialysbehandling och väntan på transplantation.</p><p>Metod: Studien är en litteratursammanställning av tio kvalitativa och kvantitativa vetenskapliga artiklar inom området, vilka har granskats, analyserats och sammanställts.</p><p>Resultat: I resultatet framkom flera olika upplevelser, så som längtan efter frihet, utmattning, höga förväntningar, frustration och rädsla inför framtiden i samband med dialysbehandlingen och väntan på transplantationen.</p><p>Slutsats: Kroniskt njursjuka patienters upplever sin situation som psykiskt, fysiskt och socialt påfrestande. En av sjuksköterskans viktigaste uppgifter i samband med bemötandet av patienter under dialysbehandling är att vara tillgänglig. Med en tillgänglig och öppen inställning till patienterna blir sjuksköterskan mer mottaglig för patienternas individuella behov.</p> / <p>Background: The number in need of kidney transplants per year is approximately 400-500, of which only about 350 will be transplanted. The shortage of organs is clearly prominent. In anticipation of the transplant patient needs dialysis, which is perceived to be time consuming and exhausting. Nurses should have knowledge of patients' experiences in connection with awaiting transplantation to be able to evolve in her role as a nurse and get a deeper understanding of the patients’ situation.</p><p>Aim: The aim of this study was to describe patients’ experiences of living with chronic kidney failure with dialysis and awaiting transplantation.</p><p>Method: The study is a literature compilation of ten qualitative and quantitative scientific articles in the field. The articles have been reviewed, analyzed and compiled. Results: The results revealed several different experiences, such as yearning for freedom, fatigue, high expectations, frustration and fear for the future in connection with the dialysis treatment and awaiting transplantation.</p><p>Conclusion: Chronic kidney disease patients perceive their situation as mentally, physically and socially stressful. One of the nurse's most important tasks in connection with the treatment of patients in dialysis is to be available. With an accessible and open approach to the patient in general, a nurse becomes more responsive to patient's individual needs.</p>
1195

Evaluation of Alginate Microcapsules for Use in Transplantation of Islets of Langerhans

King, Aileen January 2001 (has links)
<p>Transplantation of islets of Langerhans is a potential treatment of type 1 diabetes that aims to restore normal glucose homeostasis. Microencapsulation of islets could enable transplantation in the absence of immunosuppression, which would be beneficial as the side effects associated with immunosuppression outweigh the potential benefits of islet transplantation. Alginate is a polysaccharide that can be harvested from brown algae and is often used for microencapsulation of cells.</p><p>The aim of this study was to evaluate alginate/poly-L-lysine/alginate capsules with regard to their biocompatibility and permeability to cytokines. Moreover, the function of microencapsulated islets was studied <i>in vitro</i> as well as their ability to reverse hyperglycaemia in diabetic mice.</p><p>Microencapsulated rodent islets functioned well <i>in vitro</i>, with similar insulin release rates and glucose oxidation rates as naked islets. However, when cultured with interleukin-1β and tumour necrosis factor-α, microencapsulated islets were functionally suppressed, showing that the capsules are permeable to these cytokines. The biocompatibility of capsules varied depending on their composition. The presence of poly-L-lysine in the capsule decreased the biocompatibility. However, the biocompatibility of the capsules was improved when the coating alginate had been epimerised, i.e. enyzmatically tailored. Transplantation of microencapsulated allogeneic islets to immune competent mice lowered blood glucose concentrations up to 1 month after implantation. The success of the microencapsulated islet graft depended on the composition of the alginate/poly-L-lysine/alginate capsule used, as capsules that had poor biocompatibility failed to reverse hyperglycaemia more than transiently in athymic nude mice.</p><p>In conclusion, alginate/poly-L-lysine/alginate capsules can protect islets of Langerhans from allogeneic rejection in mice. However, the composition of the capsule is of critical importance in the success of transplantation. Epimerised alginates may provide a novel capsule with ideal properties for microencapsulation of islets of Langerhans.</p>
1196

Cellular Immune Responses to Allografts and Cytomegalovirus

Engstrand, Mats January 2003 (has links)
<p>Today the immunosuppressive treatment is kept to a level were the incidence of acute rejection is below 20% within the first year after transplantation. As a consequence, a group of transplanted patients is over-immunosuppressed and at risk for infections. There is therefore an urgent need for tools which are able to determine the cellular immune response after organ transplantation. This knowledge would facilitate the task of prospectively opimize the immunosuppressive treatment and identify patients at risk of developing rejection episodes or infections.</p><p>To address this issue, a rat-kidney transplantation model for acute rejection was developed to study immune responses to allografts. Infiltrating lymphocytes were analysed using an in vitro culture system which allowed cells to propagate from the biopsies to culture medium. The numbers of outgrowing cells were correlated with morphological and immunohistochemical signs of rejection. When immunosuppressive treatment was administered for 2 and four days after acute rejection, histology did not reveal any improvement, however cellular propagation was reduced by 50 and 75%, respectively. Using the tissue culture technique in human transplanted kidney grafts, which was originally developed for the animal model, the number of propagated cells measured was profoundly higher in grafts with acute cellular rejection than from grafts in other groups. In some cases the number of propagated cells was better correlated with the clinical outcome than the diagnosis made by morphological evaluation. To determine immune responses to cytomegalovirus (CMV), we utilised Human Leukocyte Antigen (HLA) tetramer staining and stimulation of T cells with viral antigens. Both of these techniques independently detected CMV specific T cells in immunosuppressed and healthy individuals with latent or active infection. Although the frequency of CMV specific T cells did not differ between groups, there was a functional impairment in immunosuppressed patients as evidenced by reduced interferon-gamma production. In conclusion, these techniques can be used to determine the cellular immune response to allografts and cytomegalovirus and prove valuable for the optimization of immunosuppressive protocols and antiviral treatment. </p>
1197

Studies of Acute Rejection Using Contrast Agents and Magnetic Resonance Imaging

Penno, Eva January 2006 (has links)
<p>Solid organ transplantation is today an established form of treatment for end-stage organ disease. Monitoring of graft function and pharmacological therapy constitutes a maze of clinical observations and histological evaluations of biopsy specimens; with the biopsy results playing a decisive role. The aims of this doctoral research were to investigate the feasibility of detecting acute rejection of transplanted organs and monitoring the effect of anti-rejection treatment, with the use of ultrasmall superparamagnetic iron oxide particles (USPIO) and magnetic resonance (MR) imaging with a clinical MR scanner.</p><p>Allogeneic and syngeneic heterotopic heart transplantations were performed in rats. Three different-sized USPIO were given to one allogeneic and one syngeneic group. The change in MR signal intensity (SI) over time was measured. An increase in SI was interpreted as damage to micro vessels due to the pronounced inflammatory reaction caused by acute rejection, which led to leakage of USPIO into the tissue. A decrease in SI was interpreted as normal vascular structure, since USPIO normally remains in the intravascular space. The same method, using one of the previously tested USPIO, was used in a treatment study in which acute rejection in transplanted rats was induced and subsequently treated. An attempt was also made to detect presence of macrophages in an acutely rejecting graft, since this cell type plays an important role in the acute rejection process; this was done by testing the ability of macrophages to phagocytose the UPSIO compound.</p><p>In permeability studies with MR imaging all three USPIO tested discriminated between rejecting and non-rejecting grafts without any overlap of the groups. Factors that contributed to the ability to distinguish between grafts were the size and half-life of the particle. We were also able to monitor effects of anti-rejection treatment by studying the vascular permeability of USPIO and MR imaging. We did not succeed in detecting macrophages in the rejecting grafts with USPIO and MR imaging.</p><p>This thesis presents a novel approach to detection of acute rejection of transplanted organs and to monitoring the effects of anti-rejection treatment using different USPIO contrast agents and MR imaging in a clinical MR scanner.</p>
1198

Experimental Studies Aiming to Prevent Type 1 Diabetes Mellitus

Rydgren, Tobias January 2007 (has links)
<p>Type 1 diabetes mellitus (T1DM) is an autoimmune disease in which T-cells and macrophages invade the islets of Langerhans and selectively destroy the insulin producing β-cells, either directly or through the secretion of e.g. cytokines and nitric oxide (NO). This thesis has studied possible strategies to prevent T1DM. In β-cells and macrophages, NO is produced by inducible nitric oxide synthase (iNOS). </p><p>In the first study, we found that 1400W, a highly selective inhibitor of iNOS could prevent interleukin (IL)-1β induced suppression of rat islet function <i>in vitro</i>, but not diabetes induced by multiple low dose streptozotocin (MLDS), a well established animal model for autoimmune diabetes, <i>in vivo</i>. </p><p>Next, we wanted to test a new type of high affinity blocker of IL-1 action, called IL-1 trap, <i>in vitro</i>. Here we found that an IL-1 trap could prevent the suppressive effects by IL-1β on rat pancreatic islet function. Also, it was sufficient to block the action of IL-1β to prevent islet cell death induced by a combination of IL-1β, tumor necrosis factor-α and interferon-γ.</p><p>In study III, a murine IL-1 trap was found to prolong islet graft survival in the recurrence of disease (ROD) model, a T1DM model that involves syngeneic transplantation of healthy pancreatic islets to diabetic nonobese diabetic mice. Mice treated with IL-1 trap displayed an increased mRNA level of the cytokine IL-4 in isolated spleen cells. This suggests a shift towards Th2-cytokine production, which in part could explain the results. </p><p>Finally, simvastatin an anti-hypercholesterolemic drug that possesses anti-inflammatory properties e.g. by interfering with transendothelial migration of leukocytes to sites of inflammation was studied. We found that the administration of simvastatin could delay, and in some mice prevent, the onset of MLDS-diabetes, and prolong islet graft survival in the ROD model. </p>
1199

Pancreatic Islet Transplantation : Modifications of Islet Properties to Improve Graft Survival

Cabric, Sanja January 2007 (has links)
<p>During the past decade clinical islet transplantation has become a viable strategy for curing type 1 diabetes. The limited supply of organs, together with the requirement for islets from multiple donors to achieve insulin independence, has greatly limited the application of this approach. </p><p>The islets are infused into the liver via the portal vein, and once exposed to the blood, the grafted tissue has been shown to be damaged by the instant blood-mediated inflammatory reaction (IBMIR), which is characterized by coagulation and complement activation as well as leukocyte infiltration into the islets. Islet revascularization is a subsequent critical step for the long-term function of the transplanted graft, which may partially be impeded by the IBMIR. </p><p>In this thesis, we have explored novel strategies for circumventing the effects of the IBMIR and facilitating islet revascularization.</p><p>Systemic inhibitors of the IBMIR are typically associated with an increased risk of bleeding. We therefore evaluated alternative strategies for modulating the islets prior to transplantation. We demonstrated, using an adenoviral vector, that a high level of expression and secretion of the anticoagulant hirudin could be induced in human islets. An alternative approach to limiting the IBMIR was developed in which anticoagulant macromolecular heparin complexes were conjugated to the islet surface. This technique proved effective in limiting the IBMIR in both an in vitro blood loop model and an allogeneic porcine model of islet transplantation. An increased adhesion of endothelial cells to the heparin-coated islet surface was demonstrated, as was the capacity of the heparin conjugate to bind the angiogenic factors VEGF and FGF; these results have important implications for the revascularization process.</p><p>The outcome of the work in this thesis suggests that modulation of the islet surface is an attractive alternative to systemic therapy as a strategy for preventing the IBMIR. Moreover, the same techniques can be employed to induce revascularization and improve the engraftment of the transplanted islets. Ultimately, improved islet viability and engraftment will make islet transplantation a more effective procedure and increase the number of patients whose diabetes can be cured.</p>
1200

Comparing the bone marrow donor registration drive at Oregon State University with peer institutions

Tsang, Christabelle W. 01 May 2003 (has links)
More than 30,000 children and adults are diagnosed with life-threatening blood diseases such as leukemia, anemia and lymphomas in the U.S. every year. A transplant of stem cells, obtained from the bone marrow of a healthy donor, can be a cure for these diseases. The National Marrow Donor Program's registry comprises almost five million potential donors, however, many ethnic minorities are still underrepresented in comparison to their percentage in the overall U.S. population. Since patients are more likely to find a matching donor within their own ethnic community, recruitment efforts have been focusing on minority donors since a number of years. A number of other studies are currently examining the psychosocial and physical effects of the donation experience, as well as identifying barriers against and reasons for donating bone marrow, using questionnaires and health models. However, none has yet looked at which recruitment settings work well for college campuses, to what extent the target group should be educated, and how the study results should be incorporated into the recruitment efforts to improve retention. Potential donor education was therefore the most important focus of a Bone Marrow Donor Registration Drive organized by the author on the OSU campus in January. 150 potential donors registered at the OSU drive, one third of them from ethnic minorities. This study examines if the drive's extensive education and outreach component had any impact on the number of newly recruited volunteer donors in comparison to OSU's peer institutions. Using the Chi square test, a proportion comparison was performed between the percentage of newly registered volunteer donors (both in total and broken down by ethnicity) among the eligible OSU student body, and the total eligible student body at each peer institution. While the hypothesis that the extensive education and promotion activities increased the number of recruited donors could not be confirmed, targeting the minorities on campus was successful, since a significantly higher proportion of minority students registered at the BMDRD than the proportion of minority students registered at OSU. Besides data on the impact of the promotional activities and the recruitment results, which can also be used for further research, the drive also yielded a protocol that can serve as a guideline for organizing future drives at OSU and other schools with similar resources. / Graduation date: 2003

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