Publications by authors named "Pol I"

Regulated systems for transgene expression are useful tools in basic research and a promising platform in biomedicine due to their regulated transgene expression by an inducer. The emergence of optogenetics expression systems enabled the construction of light-switchable systems, enhancing the spatial and temporal resolution of a transgene. The LightOn system is an optogenetic tool that regulates the expression of a gene of interest using blue light as an inducer.

View Article and Find Full Text PDF

Objectives: One of the interventions to reduce risk of central line associated bloodstream infection (CLABSI) is routine replacement of the intravenous administration sets. Guidelines advises a time interval that ranges between four and seven days. However many hospitals replace intravenous administration sets every four days to prevent CLABSI.

View Article and Find Full Text PDF

Despite wide variation among natural languages, there are linguistic properties thought to be universal to all or nearly all languages. Here, we consider universals at the semantic level, in the domain of quantifiers, which are given by the properties of monotonicity, quantity, and conservativity, and we investigate whether these universals might be explained by differences in complexity. First, we use a minimal pair methodology and compare the complexities of individual quantifiers using approximate Kolmogorov complexity.

View Article and Find Full Text PDF

Aerobic metabolism generates 15-20 times more energy (ATP) than anaerobic metabolism, which is crucial in maintaining energy budgets in animals, fueling metabolism, activity, growth and reproduction. For ectothermic water-breathers such as fishes, low dissolved oxygen may limit oxygen uptake and hence aerobic metabolism. Here, we assess, within a phylogenetic context, how abiotic and biotic drivers explain the variation in hypoxia tolerance observed in fishes.

View Article and Find Full Text PDF

Background: Extra Corporeal Life Support (ECLS) may be a life-saving treatment for patients with reversible cardiac and/or respiratory failure. ECLS is associated with a high risk of complications and mortality. Because only a small number of studies have been conducted into the long-term effects of ECLS, we investigated the difference in quality of life, anxiety and depressive complaints and PTSD 3 months after ICU discharge.

View Article and Find Full Text PDF

Background: Although life-saving in selected patients, ECMO treatment still has high mortality which for a large part is due to treatment-related complications. A feared complication is ischemic stroke for which heparin is routinely administered for which the dosage is usually guided by activated partial thromboplastin time (aPTT). However, there is no relation between aPTT and the rare occurrence of ischemic stroke (1.

View Article and Find Full Text PDF

Cell size may be important in understanding the thermal biology of ectotherms, as the regulation and consequences of cell size appear to be temperature dependent. Using a recently developed model system of triploid zebrafish (which have around 1.5-fold larger cells than their diploid counterparts) we examine the effects of cell size on gene expression, growth, development and swimming performance in zebrafish larvae at different temperatures.

View Article and Find Full Text PDF

Being composed of small cells may carry energetic costs related to maintaining ionic gradients across cell membranes as well as benefits related to diffusive oxygen uptake. Here, we test the hypothesis that these costs and benefits of cell size in ectotherms are temperature dependent. To study the consequences of cell size for whole-organism metabolic rate, we compared diploid and triploid zebrafish larvae differing in cell size.

View Article and Find Full Text PDF

There is renewed interest in the regulation and consequences of cell size adaptations in studies on understanding the ecophysiology of ectotherms. Here we test if induction of triploidy, which increases cell size in zebrafish (Danio rerio), makes for a good model system to study consequences of cell size. Ideally, diploid and triploid zebrafish should differ in cell size, but should otherwise be comparable in order to be suitable as a model.

View Article and Find Full Text PDF

The conflict between pro-self and pro-social behaviour is at the core of many key problems of our time, as, for example, the reduction of air pollution and the redistribution of scarce resources. For the well-being of our societies, it is thus crucial to find mechanisms to promote pro-social choices over egoistic ones. Particularly important, because cheap and easy to implement, are those mechanisms that can change people's behaviour without forbidding any options or significantly changing their economic incentives, the so-called "nudges".

View Article and Find Full Text PDF

Theory of mind refers to the human capacity for reasoning about others' mental states based on observations of their actions and unfolding events. This type of reasoning is notorious in the cognitive science literature for its presumed computational intractability. A possible reason could be that it may involve higher-order thinking (e.

View Article and Find Full Text PDF

Introduction: Delirium in critically-ill patients is a common multifactorial disorder that is associated with various negative outcomes. It is assumed that sleep disturbances can result in an increased risk of delirium. This study hypothesized that implementing a protocol that reduces overall nocturnal sound levels improves quality of sleep and reduces the incidence of delirium in Intensive Care Unit (ICU) patients.

View Article and Find Full Text PDF

Energy is the common currency of life. To guarantee a homeostatic supply of energy, multiple neuro-endocrine systems have evolved in vertebrates; systems that regulate food intake, metabolism, and distribution of energy. Even subtle (lasting) dysregulation of the delicate balance of energy intake and expenditure may result in severe pathologies.

View Article and Find Full Text PDF

Background: Treatment of community acquired pneumonia (CAP) patients with antibiotics before laboratory-confirmed diagnosis leads to loss of knowledge on the causative bacterial pathogen. Therefore, an increasing number of pneumococcal infections is identified using non-culture based techniques. However, methods for serotyping directly on the clinical specimen remain scarce.

View Article and Find Full Text PDF

The implementation of nationwide pneumococcal vaccination may lead to alterations in the pneumococcal population due to selective pressure induced by the vaccine. To monitor such changes, pneumococcal isolates causing invasive pneumococcal disease (IPD) before (2004-2005, n=1154) and after (2008-2009, n=1190) the implementation of the 7-valent pneumococcal vaccine (PCV7) in 2006 in the national immunization program (NIP) of The Netherlands were characterized by molecular typing using multiple-locus variable number tandem repeat analysis (MLVA) and capsular sequence typing (CST). The IPD incidence after the implementation of PCV7 in children <5 years of age declined, mainly due to an impressive reduction of cases caused by vaccine serotypes.

View Article and Find Full Text PDF

Periosteum contains mesenchymal stem cells (Pe-MSCs) that contribute to normal bone growth, healing, and turnover; understanding Pe-MSC capabilities may shed light over the treatment of bone defects using tissue engineering. Bone tissue regeneration needs in vitro bone precursors or stem cell coculture onto specific scaffolds but, despite extensive research in the field, very little is known about the matrix structure of the tissue-engineered tissues and the scaffold's effects on cell differentiation. To this purpose we have selected a clonal population (murine Pe-MSCs) that was seeded and differentiated onto an acellular bone scaffold.

View Article and Find Full Text PDF

The main virulence factor of Streptococcus pneumoniae is the capsule. The polysaccharides comprising this capsule are encoded by approximately 15 genes and differences in these genes result in different serotypes. The aim of this study was to investigate the sequence diversity of the capsular genes of serotypes 6A, 6B, 6C, 19A and 19F and to explore a possible effect of vaccination on variation and distribution of these serotypes in the Netherlands.

View Article and Find Full Text PDF

The introduction of nationwide pneumococcal vaccination may lead to serotype replacement and the emergence of new variants that have expanded their genetic repertoire through recombination. To monitor alterations in the pneumococcal population structure, we have developed and utilized Capsular Sequence Typing (CST) in addition to Multiple-Locus Variable number tandem repeat Analysis (MLVA).To assess the serotype of each isolate CST was used.

View Article and Find Full Text PDF

Prolonged spaceflights are known to elicit changes in human cardiovascular, musculoskeletal, and nervous systems, whose functions are regulated by the thyroid gland. It is known that sphingomyelin metabolism is involved in apoptosis (programmed cell death) of thyroid cells induced by UVC radiation, but at present no data exists with regard to this phenomenon, which occurs during space missions. The aim of this study was to analyze, for the first time, the effect of spaceflight on the enzymes of sphingomyelin metabolism, sphingomyelinase, and sphingomyelin synthase, and to determine whether the ratio between the two enzymes might be used as a possible marker for thyroid activity during space missions.

View Article and Find Full Text PDF

Purpose: We investigated the hypothesis that many total hip arthroplasty revisions that are classified as aseptic are in fact low-grade infections missed with routine diagnostics.

Methods: In 7 Dutch hospitals, 176 consecutive patients with the preoperative diagnosis of aseptic loosening of their total hip arthroplasty were enrolled. During surgery, between 14 and 20 tissue samples were obtained for culture, pathology, and broad-range 16S rRNA PCR with reverse line blot hybridization.

View Article and Find Full Text PDF

Emergence of serogroup B meningococci of clonal complex sequence type (ST) 41/44 can cause high levels of disease, as exemplified by a recent epidemic in New Zealand. Multiplication of annual incidence rates (3.1 cases/100,000 population) of meningococcal disease in a defined German region, the city of Aachen and 3 neighboring countries (Greater Aachen) prompted us to investigate and determine the source and nature of this outbreak.

View Article and Find Full Text PDF

We developed an efficient molecular method for the identification of the bloodmeal sources in the tick Ixodes ricinus (L.), the European vector of the agents of Lyme borreliosis and tick-borne encephalitis. An approximately 145-bp orthologous fragment of the vertebrate mitochondrial 12S rDNA was used as a molecular marker to discriminate host vertebrate species.

View Article and Find Full Text PDF

We identified many variable-number tandem repeat (VNTR) loci in the genomes of Neisseria meningitidis serogroups A, B, and C and utilized a number of these loci to develop a multiple-locus variable-number tandem repeat analysis (MLVA). Eighty-five N. meningitidis serogroup B and C isolates obtained from Dutch patients with invasive meningococcal disease and seven reference strains were analyzed using MLVA and multilocus sequence typing (MLST).

View Article and Find Full Text PDF

Recently, there has been an increase in The Netherlands in the number of cases of invasive disease caused by Haemophilus influenzae serotype b (Hib). To study a possible change in the Hib population that could explain the rise in incidence, a multiple-locus variable number tandem repeats analysis (MLVA) was developed to genotype H. influenzae isolates.

View Article and Find Full Text PDF

Five-month-old lambs were experimentally infected with two 16S rRNA genetic variants of Anaplasma phagocytophilum, variants 1 (GenBank accession no. M73220) and 2 (GenBank accession no. AF336220).

View Article and Find Full Text PDF