4,105 research outputs found
A new method for studying human polycystic kidney disease epithelia in culture
A new method for studying human polycystic kidney disease epithelia in culture. Human polycystic kidney disease (PKD) epithelia were successfully grown in culture and expressed abnormal characteristics. Cysts lining epithelia of superficial and deep cysts were microdissected and compared to individual normal human proximal straight tubules (PST) and cortical collecting tubules (CCT) grown in defined media. PKD cyst epithelia differed from normal renal tubular epithelia in growth patterns and structural and functional properties. PKD epithelia grew more rapidly and showed cyst–like areas in otherwise confluent monolayers. Polygonal and elongate cells contained an epithelial–specific cytokeratin antigen and had polarized morphology. An extremely abnormal basement membrane morphology was seen and consisted of some banded collagen and numerous unique blebs or spheroids. These blebs were apparently extruded from intracellular vacuoles and stained with ruthenium red, suggesting a proteoglycan component. Cytochemistry of marker enzymes demonstrated the presence of NaK-ATPase and alkaline phosphatase, but a lack of γ-glutamyl transpeptidase. The response of adenylate cyclase activity to vasopressin, parathyroid hormone, and forskolin was significantly diminished in PKD cells as compared to PST and CCT. These studies suggest a defect in cell growth and basement membrane synthesis in human PKD. Cultured PKD epithelia provide a new tool for the study of the pathogenesis of this disease
Reflections and Experiences of a Co-Researcher involved in a Renal Research Study
Background Patient and Public Involvement (PPI) is seen as a prerequisite for health research. However, current Patient and public involvement literature has noted a paucity of recording of patient and public involvement within research studies. There have been calls for more recordings and reflections, specifically on impact. Renal medicine has also had similar criticisms and any reflections on patient and public involvement has usually been from the viewpoint of the researcher. Roles of patient and public involvement can vary greatly from sitting on an Advisory Group to analysing data. Different PPI roles have been described within studies; one being a co-researcher. However, the role of the co-researcher is largely undefined and appears to vary from study to study. Methods The aims of this paper are to share one first time co-researcher's reflections on the impact of PPI within a mixed methods (non-clinical trial) renal research study. A retrospective, reflective approach was taken using data available to the co-researcher as part of the day-to-day research activity. Electronic correspondence and documents such as meeting notes, minutes, interview thematic analysis and comments on documents were re-examined. The co-researcher led on writing this paper. Results This paper offers a broad definition of the role of the co-researcher. The co-researcher reflects on undertaking and leading on the thematic analysis of interview transcripts, something she had not previously done before. The co-researcher identified a number of key themes; the differences in time and responsibility between being a coresearcher and an Advisory Group member; how the role evolved and involvement activities could match the co-researchers strengths (and the need for flexibility); the need for training and support and lastly, the time commitment. It was also noted that it is preferable that a co-researcher needs to be involved from the very beginning of the grant application. Conclusions The reflections, voices and views of those undertaking PPI has been largely underrepresented in the literature. The role of co-researcher was seen to be rewarding but demanding, requiring a large time commitment. It is hoped that the learning from sharing this experience will encourage others to undertake this role, and encourage researchers to reflect on the needs of those involved.Peer reviewedFinal Published versio
Non-perturbative dynamics of hot non-Abelian gauge fields: beyond leading log approximation
Many aspects of high-temperature gauge theories, such as the electroweak
baryon number violation rate, color conductivity, and the hard gluon damping
rate, have previously been understood only at leading logarithmic order (that
is, neglecting effects suppressed only by an inverse logarithm of the gauge
coupling). We discuss how to systematically go beyond leading logarithmic order
in the analysis of physical quantities. Specifically, we extend to
next-to-leading-log order (NLLO) the simple leading-log effective theory due to
Bodeker that describes non-perturbative color physics in hot non-Abelian
plasmas. A suitable scaling analysis is used to show that no new operators
enter the effective theory at next-to-leading-log order. However, a NLLO
calculation of the color conductivity is required, and we report the resulting
value. Our NLLO result for the color conductivity can be trivially combined
with previous numerical work by G. Moore to yield a NLLO result for the hot
electroweak baryon number violation rate.Comment: 20 pages, 1 figur
Phage Orf family recombinases:conservation of activities and involvement of the central channel in DNA binding
Genetic and biochemical evidence suggests that λ Orf is a recombination mediator, promoting nucleation of either bacterial RecA or phage Redβ recombinases onto single-stranded DNA (ssDNA) bound by SSB protein. We have identified a diverse family of Orf proteins that includes representatives implicated in DNA base flipping and those fused to an HNH endonuclease domain. To confirm a functional relationship with the Orf family, a distantly-related homolog, YbcN, from Escherichia coli cryptic prophage DLP12 was purified and characterized. As with its λ relative, YbcN showed a preference for binding ssDNA over duplex. Neither Orf nor YbcN displayed a significant preference for duplex DNA containing mismatches or 1-3 nucleotide bulges. YbcN also bound E. coli SSB, although unlike Orf, it failed to associate with an SSB mutant lacking the flexible C-terminal tail involved in coordinating heterologous protein-protein interactions. Residues conserved in the Orf family that flank the central cavity in the λ Orf crystal structure were targeted for mutagenesis to help determine the mode of DNA binding. Several of these mutant proteins showed significant defects in DNA binding consistent with the central aperture being important for substrate recognition. The widespread conservation of Orf-like proteins highlights the importance of targeting SSB coated ssDNA during lambdoid phage recombination
States, Banks and the Financing of the Economy: Monetary Policy and Regulatory Perspectives
On 5-6 September 2012 SUERF held its 30th Colloquium “States, Banks, and the Financing of the Economy” at the University of Zürich, Switzerland. The papers included in this SUERF Study are based on contributions to the Colloquium. All the papers in this publication discuss from different angles the complex interrelations between states and financial systems, which have developed in recent years with economic, financial and sovereign debt crises. The contributions look primarily on the monetary policy and financial regulation and supervision perspectives. In the preceding SUERF Study (2013/2), the focus of the contributions also delivered at the 30th SUERF Colloquium is on fiscal policy and sovereign debt perspectives
Association between proton pump inhibitor therapy and clostridium difficile infection: a contemporary systematic review and meta-analysis.
Abstract
Introduction
Emerging epidemiological evidence suggests that proton pump inhibitor (PPI) acid-suppression therapy is associated with an increased risk of Clostridium difficile infection (CDI).
Methods
Ovid MEDLINE, EMBASE, ISI Web of Science, and Scopus were searched from 1990 to January 2012 for analytical studies that reported an adjusted effect estimate of the association between PPI use and CDI. We performed random-effect meta-analyses. We used the GRADE framework to interpret the findings.
Results
We identified 47 eligible citations (37 case-control and 14 cohort studies) with corresponding 51 effect estimates. The pooled OR was 1.65, 95% CI (1.47, 1.85), I2 = 89.9%, with evidence of publication bias suggested by a contour funnel plot. A novel regression based method was used to adjust for publication bias and resulted in an adjusted pooled OR of 1.51 (95% CI, 1.26–1.83). In a speculative analysis that assumes that this association is based on causality, and based on published baseline CDI incidence, the risk of CDI would be very low in the general population taking PPIs with an estimated NNH of 3925 at 1 year.
Conclusions
In this rigorously conducted systemic review and meta-analysis, we found very low quality evidence (GRADE class) for an association between PPI use and CDI that does not support a cause-effect relationship
The health of women and girls determines the health and well-being of our modern world: A White Paper From the International Council on Women's Health Issues
The International Council on Women's Health Issues (ICOWHI) is an international nonprofit association dedicated to the goal of promoting health, health care, and well-being of women and girls throughout the world through participation, empowerment, advocacy, education, and research. We are a multidisciplinary network of women's health providers, planners, and advocates from all over the globe. We constitute an international professional and lay network of those committed to improving women and girl's health and quality of life. This document provides a description of our organization mission, vision, and commitment to improving the health and well-being of women and girls globally
Clinically Actionable Hypercholesterolemia and Hypertriglyceridemia in Children with Nonalcoholic Fatty Liver Disease
OBJECTIVE:
To determine the percentage of children with nonalcoholic fatty liver disease (NAFLD) in whom intervention for low-density lipoprotein cholesterol or triglycerides was indicated based on National Heart, Lung, and Blood Institute guidelines.
STUDY DESIGN:
This multicenter, longitudinal cohort study included children with NAFLD enrolled in the National Institute of Diabetes and Digestive and Kidney Diseases Nonalcoholic Steatohepatitis Clinical Research Network. Fasting lipid profiles were obtained at diagnosis. Standardized dietary recommendations were provided. After 1 year, lipid profiles were repeated and interpreted according to National Heart, Lung, and Blood Institute Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction. Main outcomes were meeting criteria for clinically actionable dyslipidemia at baseline, and either achieving lipid goal at follow-up or meeting criteria for ongoing intervention.
RESULTS:
There were 585 participants, with a mean age of 12.8 years. The prevalence of children warranting intervention for low-density lipoprotein cholesterol at baseline was 14%. After 1 year of recommended dietary changes, 51% achieved goal low-density lipoprotein cholesterol, 27% qualified for enhanced dietary and lifestyle modifications, and 22% met criteria for pharmacologic intervention. Elevated triglycerides were more prevalent, with 51% meeting criteria for intervention. At 1 year, 25% achieved goal triglycerides with diet and lifestyle changes, 38% met criteria for advanced dietary modifications, and 37% qualified for antihyperlipidemic medications.
CONCLUSIONS:
More than one-half of children with NAFLD met intervention thresholds for dyslipidemia. Based on the burden of clinically relevant dyslipidemia, lipid screening in children with NAFLD is warranted. Clinicians caring for children with NAFLD should be familiar with lipid management
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