418 research outputs found

    Vaccination Practices in Pediatric Dialysis Patients Across Europe. A European Pediatric Dialysis Working Group and European Society for Pediatric Nephrology Dialysis Working Group Study

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    Background: Data on the immunization practices in pediatric chronic kidney disease (CKD) patients are scarce. The purpose of this study was to evaluate current vaccination practices for children on dialysis across European pediatric nephrology centers. Methods: A total of 18 tertiary pediatric nephrology centers from 12 European countries were included in the study. The data on universal national immunization programs and immunization practices for children with chronic disease or risk were recorded from European Center for Disease Prevention and Control and the World Health Organization. The immunization practices and center protocols for monitoring antibody titers after vaccination in dialysis patients were obtained through a questionnaire. Results: All centers included in the study recommended immunization against hepatitis B virus (HBV), diphtheria, tetanus, pertussis, Hemophilus influenzae type b (Hib), poliomyelitis, measles, mumps, rubella (MMR), and streptococcus pneumonia in dialysis patients. In 16 centers, dialysis patients were vaccinated against influenza virus annually. HBV protective antibody titers were measured in 17 centers (during dialysis period in 14 centers, during pre-renal transplantation preparations in 14 centers or in both times in 11 centers). Hepatitis A virus (HAV) was reported to be followed in 13 centers, in 8 centers during dialysis period, and in 11 centers during pre-RTx preparations. MMR and varicella-zoster virus (VZV) protective antibody titers were measured during the dialysis period or before renal transplantation (RTx) in 12 and 15 centers, respectively, and in 6 centers both titers were checked both times. Conclusion: There are variations in vaccination practice across Europe. Children with CKD, those undergoing dialysis, and transplant candidates should receive age-appropriate vaccinations before RTx as well as before the transition to adult nephrology clinics and antibody levels should be monitored to evaluate the immunization status before and after RTx. (C) 2017 S. Karger AG, Basel.Peer reviewe

    An Experimental Workflow for Studying Barrier Integrity, Permeability, and Tight Junction Composition and Localization in a Single Endothelial Cell Monolayer: Proof of Concept

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    Endothelial and epithelial barrier function is crucial for the maintenance of physiological processes. The barrier paracellular permeability depends on the composition and spatial distribution of the cell-to-cell tight junctions (TJ). Here, we provide an experimental workflow that yields several layers of physiological data in the setting of a single endothelial cell monolayer. Human umbilical vein endothelial cells were grown on Transwell filters. Transendothelial electrical resistance (TER) and 10 kDa FITC dextran flux were measured using Alanyl-Glutamine (AlaGln) as a paracellular barrier modulator. Single monolayers were immunolabelled for Zonula Occludens-1 (ZO-1) and Claudin-5 (CLDN5) and used for automated immunofluorescence imaging. Finally, the same monolayers were used for single molecule localization microscopy (SMLM) of ZO-1 and CLDN5 at the nanoscale for spatial clustering analysis. The TER increased and the paracellular dextran flux decreased after the application of AlaGln and these functional changes of the monolayer were mediated by an increase in the ZO-1 and CLDN5 abundance in the cell–cell interface. At the nanoscale level, the functional and protein abundance data were accompanied by non-random increased clustering of CLDN5. Our experimental workflow provides multiple data from a single monolayer and has wide applicability in the setting of paracellular studies in endothelia and epithelia

    Human peritoneal tight junction, transporter and channel expression in health and kidney failure, and associated solute transport

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    Abstract Next to the skin, the peritoneum is the largest human organ, essentially involved in abdominal health and disease states, but information on peritoneal paracellular tight junctions and transcellular channels and transporters relative to peritoneal transmembrane transport is scant. We studied their peritoneal localization and quantity by immunohistochemistry and confocal microscopy in health, in chronic kidney disease (CKD) and on peritoneal dialysis (PD), with the latter allowing for functional characterizations, in a total of 93 individuals (0–75 years). Claudin-1 to -5, and -15, zonula occludens-1, occludin and tricellulin, SGLT1, PiT1/SLC20A1 and ENaC were consistently detected in mesothelial and arteriolar endothelial cells, with age dependent differences for mesothelial claudin-1 and arteriolar claudin-2/3. In CKD mesothelial claudin-1 and arteriolar claudin-2 and -3 were more abundant. Peritonea from PD patients exhibited increased mesothelial and arteriolar claudin-1 and mesothelial claudin-2 abundance and reduced mesothelial and arteriolar claudin-3 and arteriolar ENaC. Transperitoneal creatinine and glucose transport correlated with pore forming arteriolar claudin-2 and mesothelial claudin-4/-15, and creatinine transport with mesothelial sodium/phosphate cotransporter PiT1/SLC20A1. In multivariable analysis, claudin-2 independently predicted the peritoneal transport rates. In conclusion, tight junction, transcellular transporter and channel proteins are consistently expressed in peritoneal mesothelial and endothelial cells with minor variations across age groups, specific modifications by CKD and PD and distinct associations with transperitoneal creatinine and glucose transport rates. The latter deserve experimental studies to demonstrate mechanistic links. Clinical Trial registration: The study was performed according to the Declaration of Helsinki and is registered at www.clinicaltrials.gov (NCT01893710)

    Vaccination Practices in Pediatric Dialysis Patients Across Europe. A European Pediatric Dialysis Working Group and European Society for Pediatric Nephrology Dialysis Working Group Study

    No full text
    Background: Data on the immunization practices in pediatric chronic kidney disease (CKD) patients are scarce. The purpose of this study was to evaluate current vaccination practices for children on dialysis across European pediatric nephrology centers. Methods: A total of 18 tertiary pediatric nephrology centers from 12 European countries were included in the study. The data on universal national immunization programs and immunization practices for children with chronic disease or risk were recorded from European Center for Disease Prevention and Control and the World Health Organization. The immunization practices and center protocols for monitoring antibody titers after vaccination in dialysis patients were obtained through a questionnaire. Results: All centers included in the study recommended immunization against hepatitis B virus (HBV), diphtheria, tetanus, pertussis, Hemophilus influenzae type b (Hib), poliomyelitis, measles, mumps, rubella (MMR), and streptococcus pneumonia in dialysis patients. In 16 centers, dialysis patients were vaccinated against influenza virus annually. HBV protective antibody titers were measured in 17 centers (during dialysis period in 14 centers, during pre-renal transplantation preparations in 14 centers or in both times in 11 centers). Hepatitis A virus (HAV) was reported to be followed in 13 centers, in 8 centers during dialysis period, and in 11 centers during pre-RTx preparations. MMR and varicella-zoster virus (VZV) protective antibody titers were measured during the dialysis period or before renal transplantation (RTx) in 12 and 15 centers, respectively, and in 6 centers both titers were checked both times. Conclusion: There are variations in vaccination practice across Europe. Children with CKD, those undergoing dialysis, and transplant candidates should receive age-appropriate vaccinations before RTx as well as before the transition to adult nephrology clinics and antibody levels should be monitored to evaluate the immunization status before and after RTx. (C) 2017 S. Karger AG, Basel

    Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at √ s = 5.02 and 13 TeV

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    The pseudorapidity density of charged particles with minimum transverse momentum (pT) thresholds of 0.15, 0.5, 1, and 2 GeV/c is measured in pp collisions at the center of mass energies of √s=5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity (η) within 0.8pT larger than the corresponding threshold. In addition, measurements without pT-thresholds are performed for inelastic and nonsingle-diffractive events as well as for inelastic events with at least one charged particle having |η|2GeV/c), highlighting the importance of such measurements for tuning event generators. The new measurements agree within uncertainties with results from the ATLAS and CMS experiments obtained at √s=13TeV.

    Measurement of beauty production via non-prompt D0{\rm D}^{0} mesons in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 5.02 TeV

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    The production of non-prompt D0{\rm D}^{0} mesons from beauty-hadron decays was measured at midrapidity (y5 GeV/c\left| y \right| 5~\mathrm{GeV}/c in the 0100-10% central Pb-Pb collisions. The data are described by models that include both collisional and radiative processes in the calculation of beauty-quark energy loss in the quark-gluon plasma, and quark recombination in addition to fragmentation as a hadronization mechanism. The ratio of the non-prompt to prompt D0{\rm D}^{0}-meson RAAR_{\rm AA} is larger than unity for pT>4 GeV/cp_{\rm T} > 4~\mathrm{GeV}/c in the 0100-10% central Pb-Pb collisions, as predicted by models in which beauty quarks lose less energy than charm quarks in the quark-gluon plasma because of their larger mass

    First measurement of the absorption of 3He^{3}\overline{\rm He} nuclei in matter and impact on their propagation in the galaxy

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    Antimatter particles such as positrons and antiprotons abound in the cosmos. Much less common are light antinuclei, composed of antiprotons and antineutrons, which can be produced in our galaxy via high-energy cosmic-ray collisions with the interstellar medium or could also originate from the annihilation of the still undiscovered dark-matter particles. On Earth, the only way to produce and study antinuclei with high precision is to create them at high-energy particle accelerators like the Large Hadron Collider (LHC). Though the properties of elementary antiparticles have been studied in detail, knowledge of the interaction of light antinuclei with matter is rather limited. This work focuses on the determination of the disappearance probability of \ahe when it encounters matter particles and annihilates or disintegrates. The material of the ALICE detector at the LHC serves as a target to extract the inelastic cross section for \ahe in the momentum range of 1.17p<101.17 \leq p < 10 GeV/cc. This inelastic cross section is measured for the first time and is used as an essential input to calculations of the transparency of our galaxy to the propagation of 3He^{3}\overline{\rm He} stemming from dark-matter decays and cosmic-ray interactions within the interstellar medium. A transparency of about 50% is estimated using the GALPROP program for a specific dark-matter profile and a standard set of propagation parameters. For cosmic-ray sources, the obtained transparency with the same propagation scheme varies with increasing 3He^{3}\overline{\rm He} momentum from 25% to 90%. The absolute uncertainties associated to the 3He^{3}\overline{\rm He} inelastic cross section measurements are of the order of 10%-15%. The reported results indicate that 3He^{3}\overline{\rm He} nuclei can travel long distances in the galaxy, and can be used to study cosmic-ray interactions and dark-matter decays

    First study of the two-body scattering involving charm hadrons

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    This Letter presents the first measurement of the interaction between charm hadrons and nucleons. The two-particle momentum correlations of pD\mathrm{pD^-} and pD+\mathrm{\overline{p}D}^+ pairs are measured by the ALICE Collaboration in high-multiplicity pp collisions at s=13 TeV\sqrt{s} = 13~\mathrm{TeV}. The data are compatible with the Coulomb-only interaction hypothesis within (1.1-1.5)σ\sigma. Considering an attractive nucleon(N)D\overline{\mathrm{D}} strong interaction, in contrast to most model predictions which suggest an overall repulsive interaction, slightly improves the level of agreement. This measurement allows for the first time an estimation of the 68% confidence level interval for the isospin I=0\mathrm{I}=0 inverse scattering length of the ND\mathrm{N\overline{D}} state f0, I=01[0.4,0.9] fm1{f_{0,~\mathrm{I}=0}^{-1} \in [-0.4,0.9]~\mathrm{fm^{-1}}}, assuming negligible interaction for the isospin I=1\mathrm{I}=1 channel

    Study of the p-p-K+^+ and p-p-K^- dynamics using the femtoscopy technique

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    International audienceThe interactions of kaons (K) and antikaons (K\mathrm{\overline{K}}) with few nucleons (N) were studied so far using kaonic atom data and measurements of kaon production and interaction yields in nuclei. Some details of the three-body KNN and K\mathrm{\overline{K}}NN dynamics are still not well understood, mainly due to the overlap with multi-nucleon interactions in nuclei. An alternative method to probe the dynamics of three-body systems with kaons is to study the final state interaction within triplet of particles emitted in pp collisions at the Large Hadron Collider, which are free from effects due to the presence of bound nucleons. This Letter reports the first femtoscopic study of p-p-K+^+ and p-p-K^- correlations measured in high-multiplicity pp collisions at s\sqrt{s} = 13 TeV by the ALICE Collaboration. The analysis shows that the measured p-p-K+^+ and p-p-K^- correlation functions can be interpreted in terms of pairwise interactions in the triplets, indicating that the dynamics of such systems is dominated by the two-body interactions without significant contributions from three-body effects or bound states

    Studying strangeness and baryon production mechanisms through angular correlations between charged Ξ\Xi baryons and identified hadrons in pp collisions at s\sqrt{s} = 13 TeV

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    International audienceThe angular correlations between charged Ξ\Xi baryons and associated identified hadrons (pions, kaons, protons, Λ\Lambda baryons, and Ξ\Xi baryons) are measured in pp collisions at s=13\sqrt{s} = 13 TeV with the ALICE detector to give insight into the particle production mechanisms and balancing of quantum numbers on the microscopic level. In particular, the distribution of strangeness is investigated in the correlations between the doubly-strange Ξ\Xi baryon and mesons and baryons that contain a single strange quark, K and Λ\Lambda. As a reference, the results are compared to Ξπ\Xi\pi and Ξp\Xi\mathrm{p} correlations, where the associated mesons and baryons do not contain a strange valence quark. These measurements are expected to be sensitive to whether strangeness is produced through string breaking or in a thermal production scenario. Furthermore, the multiplicity dependence of the correlation functions is measured to look for the turn-on of additional particle production mechanisms with event activity. The results are compared to predictions from the string-breaking model PYTHIA 8, including tunes with baryon junctions and rope hadronisation enabled, the cluster hadronisation model HERWIG 7, and the core-corona model EPOS-LHC. While some aspects of the experimental data are described quantitatively or qualitatively by the Monte Carlo models, no one model can match all features of the data. These results provide stringent constraints on the strangeness and baryon number production mechanisms in pp collisions
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