1,433 research outputs found

    Short and Extended Provocation Tests Have Similar Negative Predictive Value in Non-Immediate Hypersensitivity to Beta-Lactams in Children

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    Drug provocation tests (DPTs) are the gold-standard method to diagnose non-immediate hypersensitivity reactions (NIHSR) to beta-lactam antibiotics (BL) in children. Our aim was to compare the negative predictive value (NPV) of one-day (short) DPT versus 3-7 days (extended) DPT for the diagnosis of NIHSR to BL in paediatric age. A secondary aim was to compare confidence on drug re-exposure after short and extended negative DPTs.info:eu-repo/semantics/publishedVersio

    Nutidens formidling af Danmarks historie?

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    Articular cartilage covering the bone ends at the joint shows different chemical composition in different regions, depending on the mechanical and biological properties of that region. Several studies have shown a relationship between the chemical composition of the cartilage and biomechanical forces. In the present study we analysed five different knee joints divided into the following regions: F1 - medial and lateral border of the patellar surface, F2 - patellar surface of the femur, F3 - medial and lateral condyles, P - articular surface of the patella and T - medial and lateral condyle of the tibia. The main glycosaminoglycan (GAG) present in these regions was chondroitin sulfate. Analysis of total GAG after digestion of the tissue with papain showed that in F2 and F3 there was a larger quantity of GAG/mg tissue, probably due to the dynamic character of the biomechanical forces in these regions. No significant differences were found for the extract and D1 fractions of the different regions. Analysis of the D4 fraction showed that the protein content was higher in the F3 and P regions than in their opposite T and F2 regions. The differences among the five regions may be a result of the non-uniform presence of biomechanical forces supported by these regions. It is important to consider that the intensity and direction of stress in different parts of a tissue may influence the composition of the extracellular matrix.179543343

    Radial Growth of Qilian Juniper on the Northeast Tibetan Plateau and Potential Climate Associations

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    There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110–2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes

    Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

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    The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor gamma (PPAR gamma), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 mu M) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs

    LINC complex-Lisl interplay controls MT1-MMP matrix digest-on-demand response for confined tumor cell migration

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    Cancer cells' ability to migrate through constricting pores in the tissue matrix is limited by nuclear stiffness. MT1-MMP contributes to metastasis by widening matrix pores, facilitating confined migration. Here, we show that modulation of matrix pore size or of lamin A expression known to modulate nuclear stiffness directly impinges on levels of MT1-MMP-mediated pericellular collagenolysis by cancer cells. A component of this adaptive response is the centrosome-centered distribution of MT1-MMP intracellular storage compartments ahead of the nucleus. We further show that this response, including invadopodia formation in association with confining matrix fibrils, requires an intact connection between the nucleus and the centrosome via the linker of nucleoskeleton and cytoskeleton (LINC) complex protein nesprin-2 and dynein adaptor Lis1. Our results uncover a digest-on-demand strategy for nuclear translocation through constricted spaces whereby confined migration triggers polarization of MT1-MMP storage compartments and matrix proteolysis in front of the nucleus depending on nucleus-microtubule linkage

    Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples

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    Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China

    The actin-myosin regulatory MRCK kinases: regulation, biological functions and associations with human cancer

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    The contractile actin-myosin cytoskeleton provides much of the force required for numerous cellular activities such as motility, adhesion, cytokinesis and changes in morphology. Key elements that respond to various signal pathways are the myosin II regulatory light chains (MLC), which participate in actin-myosin contraction by modulating the ATPase activity and consequent contractile force generation mediated by myosin heavy chain heads. Considerable effort has focussed on the role of MLC kinases, and yet the contributions of the myotonic dystrophy-related Cdc42-binding kinases (MRCK) proteins in MLC phosphorylation and cytoskeleton regulation have not been well characterized. In contrast to the closely related ROCK1 and ROCK2 kinases that are regulated by the RhoA and RhoC GTPases, there is relatively little information about the CDC42-regulated MRCKΞ±, MRCKΞ² and MRCKΞ³ members of the AGC (PKA, PKG and PKC) kinase family. As well as differences in upstream activation pathways, MRCK and ROCK kinases apparently differ in the way that they spatially regulate MLC phosphorylation, which ultimately affects their influence on the organization and dynamics of the actin-myosin cytoskeleton. In this review, we will summarize the MRCK protein structures, expression patterns, small molecule inhibitors, biological functions and associations with human diseases such as cancer

    Structural, Metabolic, and Functional Brain Abnormalities as a Result of Prenatal Exposure to Drugs of Abuse: Evidence from Neuroimaging

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    Prenatal exposure to alcohol and stimulants negatively affects the developing trajectory of the central nervous system in many ways. Recent advances in neuroimaging methods have allowed researchers to study the structural, metabolic, and functional abnormalities resulting from prenatal exposure to drugs of abuse in living human subjects. Here we review the neuroimaging literature of prenatal exposure to alcohol, cocaine, and methamphetamine. Neuroimaging studies of prenatal alcohol exposure have reported differences in the structure and metabolism of many brain systems, including in frontal, parietal, and temporal regions, in the cerebellum and basal ganglia, as well as in the white matter tracts that connect these brain regions. Functional imaging studies have identified significant differences in brain activation related to various cognitive domains as a result of prenatal alcohol exposure. The published literature of prenatal exposure to cocaine and methamphetamine is much smaller, but evidence is beginning to emerge suggesting that exposure to stimulant drugs in utero may be particularly toxic to dopamine-rich basal ganglia regions. Although the interpretation of such findings is somewhat limited by the problem of polysubstance abuse and by the difficulty of obtaining precise exposure histories in retrospective studies, such investigations provide important insights into the effects of drugs of abuse on the structure, function, and metabolism of the developing human brain. These insights may ultimately help clinicians develop better diagnostic tools and devise appropriate therapeutic interventions to improve the condition of children with prenatal exposure to drugs of abuse
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