Radboud University Nijmegen

About: Radboud University Nijmegen is a education organization based out in Nijmegen, Gelderland, Netherlands. It is known for research contribution in the topics: Population & Randomized controlled trial. The organization has 35417 authors who have published 83035 publications receiving 3285064 citations. The organization is also known as: Catholic University of Nijmegen & Radboud University.

Evidence for complete denitrification in a benthic foraminifer

Abstract: Several foraminiferal protozoa species grow in anoxic zones in marine sediment, but the type of anaerobic respiration that sustains them was not known. These organisms have now been found to accumulate nitrate intracellularly at concentrations more than 500 times the environmental values. The nitrate substitutes for oxygen in these anoxic habitats. The large amounts of nitrate that accumulate may even allow them to 'hold their breath' for more than a month. Denitrification, the biological conversion of nitrate to nitrogen, was believed to be restricted to bacteria and archaea. It has now been shown that highly abundant benthic foraminifers are also capable of denitrification, suggesting that much remains to be learned about the global nitrogen cycle. Benthic foraminifera are unicellular eukaryotes found abundantly in many types of marine sediments. Many species survive and possibly reproduce in anoxic habitats1, but sustainable anaerobic metabolism has not been previously described. Here we demonstrate that the foraminifer Globobulimina pseudospinescens accumulates intracellular nitrate stores and that these can be respired to dinitrogen gas. The amounts of nitrate detected are estimated to be sufficient to support respiration for over a month. In a Swedish fjord sediment where G. pseudospinescens is the dominant foraminifer, the intracellular nitrate pool in this species accounted for 20% of the large, cell-bound, nitrate pool present in an oxygen-free zone. Similarly high nitrate concentrations were also detected in foraminifera Nonionella cf. stella and a Stainforthia species, the two dominant benthic taxa occurring within the oxygen minimum zone of the continental shelf off Chile. Given the high abundance of foraminifera in anoxic marine environments1,2,3, these new findings suggest that foraminifera may play an important role in global nitrogen cycling and indicate that our understanding of the complexity of the marine nitrogen cycle is far from complete.

When do job demands particularly predict burnout?: The moderating role of job resources

Abstract: Purpose – The purpose of this paper is to focus on home care organization employees, and examine how the interaction between job demands (emotional demands, patient harassment, workload, and physical demands) and job resources (autonomy, social support, performance feedback, and opportunities for professional development) affect the core dimensions of burnout (exhaustion and cynicism).Design/methodology/approach – Hypotheses were tested with a cross‐sectional design among 747 Dutch employees from two home care organizations.Findings – Results of moderated structural equation modeling analyses partially supported the hypotheses as 21 out of 32 (66 per cent) possible two‐way interactions were significant and in the expected direction. In addition, job resources were stronger buffers of the relationship between emotional demands/patient harassment and burnout, than of the relationship between workload/physical demands and burnout.Practical implications – The conclusions may be particularly useful for occupat...

Broad defects in the energy metabolism of leukocytes underlie immunoparalysis in sepsis

Abstract: The acute phase of sepsis is characterized by a strong inflammatory reaction. At later stages in some patients, immunoparalysis may be encountered, which is associated with a poor outcome. By transcriptional and metabolic profiling of human patients with sepsis, we found that a shift from oxidative phosphorylation to aerobic glycolysis was an important component of initial activation of host defense. Blocking metabolic pathways with metformin diminished cytokine production and increased mortality in systemic fungal infection in mice. In contrast, in leukocytes rendered tolerant by exposure to lipopolysaccharide or after isolation from patients with sepsis and immunoparalysis, a generalized metabolic defect at the level of both glycolysis and oxidative metabolism was apparent, which was restored after recovery of the patients. Finally, the immunometabolic defects in humans were partially restored by therapy with recombinant interferon-γ, which suggested that metabolic processes might represent a therapeutic target in sepsis.

Peptide- and Protein-Based Hydrogels

Abstract: Hydrogels are polymeric networks, capable of absorbing large amounts of water and biological fluids. They are insoluble due to the presence of chemical or physical cross-links between the constituents. Hydrogels are promising materials for use as injectable biomaterials due to their high water content, tunable viscoelasticity, and biocompatibility. Peptides and proteins are important building blocks in the design of hydrogels, since they are easily degraded by the body and display a high biocompatibility. This review aims to give an overview of hydrogels in which peptides and proteins are structural elements of the polymer network. The review starts with hydrogels derived from naturally occurring structural proteins, followed by all-protein and peptide-based synthetic systems. Next, hybrid hydrogels composed of synthetic polymeric and peptide structural elements will be discussed. The potential of these hydrogels is illustrated with applications that are mainly derived from the field of tissue engineering.

Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology: A Systematic Review and Meta-analysis

Abstract: Importance: Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date. Objectives: To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions. Data Sources: PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC. Study Selection: Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex. Data Extraction and Synthesis: Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept. Main Outcome and Measure: The cNfL levels adjusted for age and sex across diagnoses. Results: Data were collected for 10059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes. Conclusions and Relevance: These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.