1,720,980 research outputs found
Vascular calcification and mineral bone disorder in chronic kidney disease
No full textChronic Kidney Disease (CKD), osteoporosis and mild hyponatremia are all prevalent chronic conditions that may coexist and are often under-recognized. Mineral-Bone Disorder begins early in the natural history of CKD and results in complex abnormalities of bone which ultimately confers a well-established increased risk of fragility fractures in End Stage Kidney Disease. Hyponatremia is a novel, usually renal mediated metabolic perturbation, that most commonly occurs independently of the stage of renal dysfunction but which may also predispose to increased fracture risk. The extent -if any- to which either early stages of renal dysfunction or the presence of hyponatremia contribute to fracture occurrence in the general population, independently of osteoporosis, is unclear. Renal transplantation is the treatment of choice for ESKD and although it restores endogenous renal function it typically fails to normalize either the long term cardiovascular or fracture risk. One potential mechanism contributing to these elevated long-term risks and to diminished Health Related Quality of Life is persistent, post-transplant hyperparathyroidism. In this study we retrospectively examine the association of renal function and serum sodium with Bone Mineral Density and fracture occurrence in a retrospective cohort of 1930 female members of the general population who underwent routine DXA scan. We then prospectively recruited a cohort of 90 renal transplant recipients in order to examine the association of post transplant parathyroid hormone (PTH) level with measures of CKD Mineral Bone Disorder, including, DXA Bone Mineral Density, Vascular Calcification (assessed using both abdominal radiography and CT techniques, as well as indirectly by carotid-femoral Pulse Wave Velocity) and Quality of Life (using the Short Form-12 and a PTH specific symptom score). In the retrospective DXA cohort, moderate CKD (eGFR 30-59ml/min/1.73m2) and hyponatremia (<135mmol/L) were associated with fracture occurrence, independently of BMD, with an adjusted Odds Ratio (95% Confidence Interval), of 1.37 (1.0, 1.89) and 2.25 (1.24, 4.09) respectively. In the renal transplant study, PTH was independently associated with the presence of osteoporosis, adjusted Odds Ratio (95% Confidence Interval), 1.15 (per 10ng/ml increment), (1.04, 1.26). The presence of osteoporosis but not PTH was independently associated with measures of vascular calcification, adjusted ß (95% Confidence Interval), 12.45, (1.16, 23.75). Of the eight quality-of-life domains examined, post-transplant PTH (per 10ng/ml increment), was only significantly and independently associated with reduced Physical Functioning, (95% Confidence Interval), 1.12 (1.01, 1.23). CKD and hyponatremia are both common health problems that may contribute to fracture occurrence in the general population, a major on-going public health concern. PTH and decreased Bone Mineral Density may signal sub-optimal long-term outcomes post renal transplantation, influencing bone and vascular health and to a limited extent long term Health Related Quality of Lif
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Clinical outcomes of real-world Kalydeco (ivacaftor); Cork study - understanding the implications of CFTR modulation
Full text linkCF represents one of the success stories of modern medicine with sustained incremental increases in survival from one of childhood death to one of adulthood survival. Traditionally the management of CF has focused on treating the consequences of CFTR dysfunction. The advent of ivacaftor offers the opportunity to evaluate the effect of restoration of CFTR function on CF lung disease and extrapulmonary manifestations. Global prevalence of the G551D mutation is 4%. Prevalance at Cork CF centre is 23%. Thus this work evaluates the effect of CFTR modulation on clinical parameters, Chest CT, lung microbiota, gut microbiota, gut inflammation, pancreatic function and benefit to the individual patient
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Studying glomerular disease epidemiology: tackling challenges and paving a path forward
Full text linkBackground:
Glomerular diseases are a group of rare immune-mediated kidney diseases that affect the glomeruli, or filtering units, of the kidney. Major knowledge gaps remain in our understanding of glomerular disease epidemiology. Efforts to describe glomerular disease distributions based on geographic, demographic, and temporal factors (descriptive epidemiology) are limited by the absence of population-level disease registries in most jurisdictions. The extent to which glomerular disease subtype independently associates with clinical outcomes (analytic epidemiology), especially once kidney disease has progressed to end-stage kidney failure, remains largely unknown. Further, much of what is known regarding glomerular disease epidemiology is derived from the experiences of highly-selected patient populations enrolled in clinical trials or attending academic medical centres. Larger-scale, population-level, studies of glomerular disease epidemiology would help to close knowledge gaps regarding the distribution and determinants of glomerular disease and, in doing so, would inform clinical care, public health policy, and clinical trial design.
Hypotheses:
Two major hypotheses are explored in this thesis: 1. Significant geographic and temporal variation in glomerular disease frequencies exist, that are not solely explained by racial-ethnic variation, thus supporting a role for socioeconomic and environmental factors in the development of clinically manifest glomerular disease; 2. Glomerular disease subtype independently associates with clinical outcomes even after glomerular disease has advanced to end-stage kidney failure, challenging the prevailing paradigm to group all glomerular disease subtypes together in research and public health reporting of clinical outcomes in patients with end-stage kidney failure.
Aims:
The overall aim of this research was to close knowledge gaps in glomerular disease epidemiology by identifying geographic and temporal variation in glomerular disease frequency distributions and by determining associations between glomerular disease subtype and clinical outcomes (mortality, cardiovascular events) in patients with end-stage kidney failure.
Methods:
For the first two manuscripts (Chapters 3 and 4), I analysed two large-scale pathology datasets created by my collaborator, Dr. Charles Jeannette: a) the International Kidney Biopsy Survey (IKBS) that includes kidney biopsy diagnoses and associated patient demographics from 29 international kidney pathology laboratories, which I used to study geographic variation in glomerular disease frequencies within and across racial-ethnic groups; b) the Glomerular Disease Collaborative Network (GDCN), a registry of all kidney biopsies referred to the University of North Carolina since 1986, which I used to study temporal trends in glomerular disease frequencies within and across demographic groups over the last three decades. For the next two manuscripts (Chapters 5 and 6), I analysed data – including physician-reported cause of kidney failure – from virtually all U.S. patients with treated end-stage kidney failure who are enrolled, by federal mandate, in the United States Renal Data System (USRDS). In the first of these two manuscripts, I determined associations between glomerular disease subtype and mortality; in the second, I determined associations between glomerular disease subtype and cardiovascular events. Advanced statistical methods included multivariable regression to handle confounding, proportional sub-distribution hazard models to handle competing events, and multiple imputation to handle missing data.
Results:
Major findings from these manuscripts include: a) significant differences in glomerular disease frequencies across continents, even among patients with similar racial-ethnic backgrounds; b) significant temporal trends in the relative frequencies of many biopsy-proven glomerular diseases, including stabilization in the 21st century of the rapid increase in focal segmental glomerulosclerosis observed at the end of the 20th century, and a dramatic increase in diabetic glomerulosclerosis over time, to become the second most frequent biopsy-proven glomerular disease diagnosis in the modern era; c) significant differences in the hazards of mortality and cardiovascular events across glomerular disease subtypes, even after accounting for between-group differences in case-mix.
Conclusions:
In addition to answering specific research questions regarding glomerular disease epidemiology, this research exemplifies the strengths and feasibility of population-level, internationally collaborative, approaches to studying glomerular diseases. Findings from these studies can shape public health policy (e.g. promotion of healthy lifestyle approaches to curb the high frequency of diabetic glomerulosclerosis in contemporary U.S. populations), future research design (e.g. recognising the importance of glomerular disease subtype as a prognostic indicator in studies involving patients with end-stage kidney failure), and clinical care (e.g. formulating differential diagnoses based on patient demographics, or counselling U.S. patients regarding their absolute and relative risks of mortality and cardiovascular events following dialysis initiation)
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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