Sökresultat

Filtyp

Din sökning på "*" gav 533241 sökträffar

On longitudinal prediction with time-to-event outcome : Comparison of modeling options

Long-term follow-up is common in many medical investigations where the interest lies in predicting patients’ risks for a future adverse outcome using repeatedly measured predictors over time. A key quantity is the likelihood of developing an adverse outcome among individuals who survived up to time s given their covariate information up to time s. Simple, yet reliable, methodology for updating the

Risk prediction to inform surveillance of chronic kidney disease in the US Healthcare Safety Net : A cohort study

Background: The capacity of electronic health record (EHR) data to guide targeted surveillance in chronic kidney disease (CKD) is unclear. We sought to leverage EHR data for predicting risk of progressing from CKD to end-stage renal disease (ESRD) to help inform surveillance of CKD among vulnerable patients from the healthcare safety-net. Methods: We conducted a retrospective cohort study of adult

Evaluating risk of ESRD in the urban poor

The capacity of risk prediction to guide management of CKD in underserved health settings is unknown. We conducted a retrospective cohort study of 28,779 adults with nondialysis-requiring CKD who received health care in two large safety net health systems during 1996-2009 and were followed for ESRD through September of 2011. We developed and evaluated the performance of ESRD risk prediction models

Plasma-free fatty acids, fatty acidebinding protein 4, and mortality in older adults (from the cardiovascular health study)

Plasma-free fatty acids (FFAs) are largely derived from adipose tissue. Elevated levels of FFA and fatty acidebinding protein 4 (FABP4), a key cytoplasmic chaperone of fatty acids, have been associated with adverse cardiovascular outcomes, but limited data are available on the relation of these biomarkers with cardiovascular and total mortality. We studied 4,707 participants with a mean age of 75

Plasma free fatty acids and risk of stroke in the Cardiovascular Health Study

Background: Although free fatty acids have been positively associated with risk factors for stroke, the role of plasma free fatty acids in the development of stroke has not been elucidated in older adults. Aims: We sought to examine the association between plasma free fatty acids and incident stroke. Methods: Prospective cohort of 4369 men and women ≥65 years of age in the Cardiovascular Health St

Towards a unified protocol for handling of CSF before β-amyloid measurements

Background: Widespread implementation of Alzheimer's disease biomarkers in routine clinical practice requires the establishment of standard operating procedures for pre-analytical handling of cerebrospinal fluid (CSF). Methods: Here, CSF collection and storage protocols were optimized for measurements of β-amyloid (Aβ). We investigated the effects of (1) storage temperature, (2) storage time, (3)

Quality of supply regulations versus societal priorities regarding electricity outage consequences : Case study in a Swedish context

Modern society is increasingly dependent on a reliable supply of electricity. Depending on where an electricity outage occurs and who is affected the consequences may range from a mere nuisance to major economic losses or actual threats against the health and safety of citizens. The direct costs of power outages have been assessed in numerous studies, however electricity outages normally also enta

Assessment and benchmarking of spatially enabled RDF stores for the next generation of spatial data infrastructure

Geospatial information is indispensable for various real-world applications and is thus a prominent part of today’s data science landscape. Geospatial data is primarily maintained and disseminated through spatial data infrastructures (SDIs). However, current SDIs are facing challenges in terms of data integration and semantic heterogeneity because of their partially siloed data organization. In th

Homelessness and risk of end-stage renal disease

To identify homeless people with chronic kidney disease (CKD) who were at highest risk for end-stage renal disease (ESRD), we studied 982 homeless and 15,674 domiciled people with CKD receiving public health care. We developed four risk prediction models for the primary outcome of ESRD. Overall, 71 homeless and 888 domiciled people progressed to ESRD during follow-up (median: 6.6 years). Homeless

Circulating fibrosis biomarkers and risk of atrial fibrillation : The Cardiovascular Health Study (CHS)

Background Cardiac fibrosis is thought to play a central role in the pathogenesis of atrial fibrillation (AF). Retrospective studies have suggested that circulating fibrosis biomarkers are associated with AF, but prospective studies are limited. Methods We measured circulating levels of 2 fibrosis biomarkers, procollagen type III, N-terminal propeptide (PIIINP) and transforming growth factor β1 am

Plasma fatty acid binding protein 4 and risk of sudden cardiac death in older adults

Although fatty acid binding protein 4 (FABP4) may increase risk of diabetes and exert negative cardiac inotropy, it is unknown whether plasma concentrations of FABP4 are associated with incidence of sudden cardiac death (SCD). We prospectively analyzed data on 4,560 participants of the Cardiovascular Health Study. FABP4 was measured at baseline using ELISA, and SCD events were adjudicated through

Activation of enteroendocrine membrane progesterone receptors promotes incretin secretion and improves glucose tolerance in mice

Glucagon-like peptide-1 (GLP-1) secretion is classically regulated by ingested nutrients. To identify novel molecular targets controlling incretin secretion, we analyzed enteroendocrine cell pathways important for hormone biosynthesis and secretion. We demonstrate that progesterone increases GLP-1 secretion and extracellular signal-related kinase 1/2 (ERK1/2) phosphorylation in enteroendocrine GLU

Anti-idiotypic antibody specific to GAD65 autoantibody prevents type 1 diabetes in the NOD mouse

Overt autoantibodies to the smaller isoform of glutamate decarboxylase (GAD65Ab) are a characteristic in patients with Type 1 diabetes (T1D). Anti-idiotypic antibodies (anti-Id) directed to GAD65Ab effectively prevent the binding of GAD65 to GAD65Ab in healthy individuals. Levels of GAD65Ab-specific anti-Id are significantly lower in patients with T1D, leading to overt GAD65Ab in these patients. T

Effects of vasoactive agents on blood loss and transfusion requirements during pre-reperfusion stages of the orthotopic liver transplantation

Objective: To evaluate the effects of vasoactive drugs, specifically low-dose vasopressin and phenylephrine infusions, on blood loss / transfusion requirements during dissection and anhepatic (pre-reperfusion) stages of orthotopic liver transplantations. Methods: A retrospective analysis of 110 orthotopic liver transplantation (OLT) cases was performed. The variables studied were: blood loss befor

ErbB Signaling Is Required for the Proliferative Actions of GLP-2 in the Murine Gut

Background & Aims: Glucagon-like peptide-2 (GLP-2) is a 33-amino acid peptide hormone secreted by enteroendocrine cells in response to nutrient ingestion. GLP-2 stimulates crypt cell proliferation leading to expansion of the mucosal epithelium; however, the mechanisms transducing the trophic effects of GLP-2 are incompletely understood. Methods: We examined the gene expression profiles and gro

The Glucagon Receptor Is Required for the Adaptive Metabolic Response to Fasting

Glucagon receptor (Gcgr) signaling maintains hepatic glucose production during the fasting state; however, the importance of the Gcgr for lipid metabolism is unclear. We show here that fasted Gcgr-/- mice exhibit a significant increase in hepatic triglyceride secretion and fasting increases fatty acid oxidation (FAO) in wild-type (WT) but not in Gcgr-/- mice. Moreover fasting upregulated the expre

Modulation of diabetes in NOD mice by GAD65-specific monoclonal antibodies is epitope specific and accompanied by anti-idiotypic antibodies

Type 1 diabetes is caused by the autoimmune destruction of pancreatic beta cells. Here we show that administration of a human monoclonal antibody (b96.11) specific to the 65-kDa isoform of glutamate decarboxylase (GAD65) to prediabetic non-obese diabetic (NOD) mice significantly delays the onset of autoimmune diabetes. We found this effect to be epitope-specific, as only b96.11 showed this therape

Integrating global proteomic and genomic expression profiles generated from islet α cells : Opportunities and challenges to deriving reliable biological inferences

Systematic profiling of expressed gene products represents a promising research strategy for elucidating the molecular phenotypes of islet cells. To this end, we have combined complementary genomic and proteomic methods to better assess the molecular composition of murine pancreatic islet glucagon-producing αTC-1 cells as a model system, with the expectation of bypassing limitations inherent to ei

Characterization and functional role of voltage gated cation conductances in the glucagon-like peptide-1 secreting GLUTag cell line

Glucagon-like peptide-1 (GLP-1) is released from intestinal L-cells in response to nutrient ingestion. It is currently under therapeutic evaluation because it enhances insulin secretion in type 2 diabetes. Previous studies using the GLP-1 secreting cell line GLUTag have shown that the cells are electrically active, and that the action potential frequency is regulated by nutrients. In this study we

Binary tree-structured vector quantization approach to clustering and visualizing microarray data

Motivation: With the increasing number of gene expression databases, the need for more powerful analysis and visualization tools is growing. Many techniques have successfully been applied to unravel latent similarities among genes and/or experiments. Most of the current systems for microarray data analysis use statistical methods, hierarchical clustering, self-organizing maps, support vector machi