233 research outputs found

    The use of the multivariate Principal Response Curve (PRC) for community analysis: a case study on the effects of carbendazim on enchytraeids in Terrestrial Model Ecosystems (TME).

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    The effects of the fungicide carbendazim (formulation Derosal®) on enchytraeids were determined in Terrestrial Model Ecosystem (TME) tests. TMEs consisted of intact soil columns (diameter 17.5 cm; length 40 cm) taken from three grassland sites (Amsterdam (The Netherlands), Bangor (Wales, England) and Flörsheim (Germany)) or an arable site (Coimbra (Portugal)). Results for each TME site were evaluated using the multivariate Principal Response Curve (PRC) method. The resulting No-Observable Effect Concentrations (NOECs) for the community were compared with the NOECs generated by univariate statistical methods. Furthermore, the E

    Proteome turnover in the bloodstream and procyclic forms of <i>Trypanosoma brucei</i> measured by quantitative proteomics

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    Background: Cellular proteins vary significantly in both abundance and turnover rates. These parameters depend upon their rates of synthesis and degradation and it is useful to have access to data on protein turnover rates when, for example, designing genetic knock-down experiments or assessing the potential usefulness of covalent enzyme inhibitors. Little is known about the nature and regulation of protein turnover in Trypanosoma brucei, the etiological agent of human and animal African trypanosomiasis.Methods: To establish baseline data on T.brucei proteome turnover, a Stable Isotope Labelling with Amino acids in Cell culture (SILAC)-based mass spectrometry analysis was performed to reveal the synthesis and degradation profiles for thousands of proteins in the bloodstream and procyclic forms of this parasite.Results: This analysis revealed a slower average turnover rate of the procyclic form proteome relative to the bloodstream proteome. As expected, many of the proteins with the fastest turnover rates have functions in the cell cycle and in the regulation of cytokinesis in both bloodstream and procyclic forms. Moreover, the cellular localization of T. brucei proteins correlates with their turnover, with mitochondrial and glycosomal proteins exhibiting slower than average turnover rates.Conclusions: The intention of this study is to provide the trypanosome research community with a resource for protein turnover data for any protein or group of proteins. To this end, bioinformatic analyses of these data are made available via an open-access web resource with data visualization functions.</p

    The Extracellular Domain of Myelin Oligodendrocyte Glycoprotein Elicits Atypical Experimental Autoimmune Encephalomyelitis in Rat and Species

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    Atypical models of experimental autoimmune encephalomyelitis (EAE) are advantageous in that the heterogeneity of clinical signs appears more reflective of those in multiple sclerosis (MS). Conversely, models of classical EAE feature stereotypic progression of an ascending flaccid paralysis that is not a characteristic of MS. The study of atypical EAE however has been limited due to the relative lack of suitable models that feature reliable disease incidence and severity, excepting mice deficient in gamma-interferon signaling pathways. In this study, atypical EAE was induced in Lewis rats, and a related approach was effective for induction of an unusual neurologic syndrome in a cynomolgus macaque. Lewis rats were immunized with the rat immunoglobulin variable (IgV)-related extracellular domain of myelin oligodendrocyte glycoprotein (IgV-MOG) in complete Freund’s adjuvant (CFA) followed by one or more injections of rat IgV-MOG in incomplete Freund’s adjuvant (IFA). The resulting disease was marked by torticollis, unilateral rigid paralysis, forelimb weakness, and high titers of anti-MOG antibody against conformational epitopes of MOG, as well as other signs of atypical EAE. A similar strategy elicited a distinct atypical form of EAE in a cynomolgus macaque. By day 36 in the monkey, titers of IgG against conformational epitopes of extracellular MOG were evident, and on day 201, the macaque had an abrupt onset of an unusual form of EAE that included a pronounced arousal-dependent, transient myotonia. The disease persisted for 6–7 weeks and was marked by a gradual, consistent improvement and an eventual full recovery without recurrence. These data indicate that one or more boosters of IgV-MOG in IFA represent a key variable for induction of atypical or unusual forms of EAE in rat and Macaca species. These studies also reveal a close correlation between humoral immunity against conformational epitopes of MOG, extended confluent demyelinating plaques in spinal cord and brainstem, and atypical disease induction

    Wat werkt in kunstzinnige oriëntatie?:Reviewstudie naar beïnvloedbare factoren voor leerprestaties bij kunstzinnige oriëntatie in het primair onderwijs

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    Onder regie van de Inspectie van het Onderwijs worden periodieke onderzoeken uitgevoerd naar de inhoud, kwaliteit en het niveau van een bepaald leergebied. Deze onderwijspeilingen richten zich op groep 8 van het primair onderwijs (po). Het gaat daarbij om twee vragen: welke kennis en vaardigheden hebben leerlingen op het onderzochte gebied en hoe ziet het aanbod van scholen eruit op dat leergebied? Voorafgaand aan een peiling maakt SLO een domeinbeschrijving van het betreffende gebied. Daarnaast wordt een reviewstudie uitgevoerd naar wat uit internationaal onderzoek bekend is over beïnvloedbare factoren die bijdragen aan leerprestaties van leerlingen. Deze review ondersteunt de ontwikkeling van onderzoeksinstrumenten om de aanbodkenmerken van het onderwijs in kaart te brengen.In schooljaar 2024/2025 zal een peiling plaatsvinden van het onderwijsniveau van kunstzinnige oriëntatie aan het eind van de basisschool. Kunstzinnige oriëntatie omvat de kunstdisciplines beeldend, dans, drama, muziek en cultureel erfgoed. In 2015/2016 vond de vorige peiling kunstzinnige oriëntatie plaats (Inspectie van het Onderwijs, 2016). Geruime tijd daarvoor, in de jaren negentig van de vorige eeuw, waren er peilingen van muziek (Weerden &amp; Veldhuijzen, 2000) en beeldend (Hermans et al., 2001).Ter voorbereiding van de peiling in 2024 heeft het Lectoraat Kunsteducatie van de Amsterdamse Hogeschool voor de Kunsten een reviewstudie uitgevoerd. Centrale vraagstelling van deze studie is: wat is er bekend over beïnvloedbare factoren voor leerprestaties bij kunstzinnige oriëntatie in (het einde van) het primair onderwijs

    PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study:protocol for a hybrid type I, mixed method, randomised controlled trial

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    INTRODUCTION: Kidney transplant candidates (KTCs) need to be in optimal physical and psychological condition prior to surgery. However, KTCs often experience compromised functional capacity which can be characterised as frailty. Prehabilitation, the enhancement of a person's functional capacity, may be an effective intervention to improve the health status of KTCs. The PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study aims to examine the effectiveness of a multimodal prehabilitation programme on the health status of KTCs, and to explore the potential of implementation of prehabilitation in daily clinical practice.METHODS AND ANALYSIS: This study uses a single centre, effectiveness-implementation hybrid type I study design, comprised of a randomised controlled trial and a mixed-methods study. Adult patients who are currently on the transplant waiting list or are waitlisted during the study period, at a university medical centre in The Netherlands, will be randomly assigned to either prehabilitation (n=64) or care as usual (n=64) groups. The prehabilitation group will undergo a 12-week home-based, tailored prehabilitation programme consisting of physical and/or nutritional and/or psychosocial interventions depending on the participant's deficits. This programme will be followed by a 12-week maintenance programme in order to enhance the incorporation of the interventions into daily life. The primary endpoint of this study is a change in frailty status as a proxy for health status. Secondary endpoints include changes in physical fitness, nutritional status, psychological well-being, quality of life and clinical outcomes. Tertiary endpoints include the safety, feasibility and acceptability of the prehabilitation programme, and the barriers and facilitators for further implementation.ETHICS AND DISSEMINATION: Medical ethical approval was granted by the Medical Ethics Committee Groningen, Netherlands (M22.421). Written informed consent will be obtained from all participants. The results will be disseminated at international conferences and in peer-reviewed journals.TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, NCT05489432.</p

    Outcomes that matter most to burn patients:A national multicentre survey study in the Netherlands

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    Background: The use of patient-reported outcomes to improve burn care increases. Little is known on burn patients’ views on what outcomes are most important, and about preferences regarding online Patient Reported Outcome Measures (PROMs). Therefore, this study assessed what outcomes matter most to patients, and gained insights into patient preferences towards the use of online PROMs. Methods: Adult patients (≥18 years old), 3–36 months after injury completed a survey measuring importance of outcomes, separately for three time periods: during admission, short-term (&lt;6 months) and long-term (6–24 months) after burn injury. Both open and closed-ended questions were used. Furthermore, preferences regarding the use of patient-reported outcome measures in burn care were queried. Results: A total of 140 patients were included (response rate: 27%). ‘Not having pain’ and ‘good wound healing’ were identified as very important outcomes. Also, ‘physical functioning at pre-injury level’, ‘being independent’ and ‘taking care of yourself’ were considered very important outcomes. The top-ten of most important outcomes largely overlapped in all three time periods. Most patients (84%) had no problems with online questionnaires, and many (67%) indicated that it should take up to 15 minutes. Patients’ opinions differed widely on the preferred frequency of follow-up. Conclusions: Not having pain and good wound healing were considered very important during the whole recovery of burns; in addition, physical functioning at pre-injury level, being independent, and taking care of yourself were deemed very important in the short and long-term. These outcomes are recommended to be used in burn care and research, although careful selection of outcomes remains crucial as patients prefer online questionnaires up to 15 minutes.</p

    The unusual kinetics of lactate dehydrogenase of Schistosoma mansoni and their role in the rapid metabolic switch after penetration of the mammalian host

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    Lactate dehydrogenase (LDH) from Schistosoma mansoni has peculiar properties for a eukaryotic LDH. Schistosomal LDH (SmLDH) isolated from schistosomes, and the recombinantly expressed protein, are strongly inhibited by ATP, which is neutralized by fructose-1,6-bisphosphate (FBP). In the conserved FBP/anion binding site we identified two residues in SmLDH (Val187 and Tyr190) that differ from the conserved residues in LDHs of other eukaryotes, but are identical to conserved residues in FBP-sensitive prokaryotic LDHs. Three-dimensional (3D) models were generated to compare the structure of SmLDH with other LDHs. These models indicated that residues Val187, and especially Tyr190, play a crucial role in the interaction of FBP with the anion pocket of SmLDH. These 3D models of SmLDH are also consistent with a competitive model of SmLDH inhibition in which ATP (inhibitor) and FBP (activator) compete for binding in a well-defined anion pocket. The model of bound ATP predicts a distortion of the nearby key catalytic residue His195, resulting in enzyme inhibition. To investigate a possible physiological role of this allosteric regulation of LDH in schistosomes we made a kinetic model in which the allosteric regulation of the glycolytic enzymes can be varied. The model showed that inhibition of LDH by ATP prevents fermentation to lactate in the free-living stages in water and ensures complete oxidation via the Krebs cycle of the endogenous glycogen reserves. This mechanism of allosteric inhibition by ATP prevents the untimely depletion of these glycogen reserves, the only fuel of the free-living cercariae. Neutralization by FBP of this ATP inhibition of LDH prevents accumulation of glycolytic intermediates when S. mansoni schistosomula are confronted with the sudden large increase in glucose availability upon penetration of the final host. It appears that the LDH of S. mansoni is special and well suited to deal with the variations in glucose availability the parasite encounters during its life cycle.</p
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