1,287 research outputs found

    Prevalence of vitamin D deficiency in an inpatient population in the Swiss canton of Basel-Country

    Get PDF
    AIMS: Vitamin D deficiency remains very common in the general population. Adding to the importance of this issue is the discovery that vitamin D plays a role in many other tissues apart from the bone, including muscle, brain, prostate, breast and colon. In this study, we investigated the prevalence of vitamin D deficiency in a large group of patients hospitalised in the cantonal hospital Basel-Country, and analysed the dependence of serum vitamin D concentrations on gender, time of the year and age. METHODS: We retrospectively analysed anonymised data received from the central laboratory of the cantonal hospital Basel-Country. The pool of data contains values obtained between 2013 and 2017 from 8861 patients aged between 18 and 102 years. If sequential measurements were available from a patient, only the first was used for the analyses. Vitamin D deficiency was defined as a serum concentration of <50 nmol/l and severe deficiency as 75 nmol/l. RESULTS: Mean ± standard deviation serum vitamin D concentration was 52.5 ± 30.5 nmol/l, with women having a higher mean of 55.5 ± 31.5 nmol/l as compared with 48.1 ± 28.6 nmol/l in men (p <10-5). Of the 8861 first measurements taken within the observation period, 4527 (51%) were vitamin D deficient with levels <50 nmol/l, including 1860 (21.0%) with levels <25 nmol/l. There was only a weak positive association of average vitamin D levels with age (p = 0.06). Women reached peak concentrations of 56.9 ± 35.4 nmol/l in the age group 90-102 years, whereas men reached peaks of 50.3 ± 31.9 nmol/l in 50-59-year-olds. Mean autumn and spring concentrations differed less (51.6 ± 29.6 vs 52.7 ± 30.7 nmol/l, respectively, p = 0.38) than mean summer and winter concentrations (57.1 ± 29.5 vs 48.0 ± 31.2 nmol/l, respectively, p 75 nmol/l, only 22.1% of measured values indicated adequate vitamin D levels. This issue should be addressed in order to improve quality of life and reduce medical costs.

    Effect of altered loading conditions during haemodialysis on left ventricular filling pattern

    Get PDF
    Changes in the circulating volume associated with haemodialysis result in modification of left ventricular loading conditions. To determine the influence of haemodialysis on Doppler indices of left ventricular filling, 12 patients (mean age 40.8 ±2.7 (SEM) years) with renal insufficiency but without overt heart disease were studied by Doppler-echocardiography immediately before and after haemodialysis. Haemodialysis resulted in a decrease in body weight from 68.0±3.8 kg to 65.0 ±3.7 kg (P< 0.01). Heart rate and blood pressure did not change significantly during haemodialysis. Left ventricular diastolic dimension (M-mode) decreased from 53.5±1.1 mm to 49.5±1.9 mm (P < 0.05), whereas the shortening fraction did not change. Haemodialysis elicited marked changes in the early diastolic rapid filling wave (E wave) recorded by pulsed Doppler at the level of the mitral annulus. Peak velocity of the early rapid filling phase (peak E) decreased significantly from 95.3 ± 8.2 cm .s−1 to 63.0 ±5.7cm .s−1 (P< 0.001) and mid-diastolic deceleration of transmitral velocity decreased from 437.3 ±54.2 cm . s−2 to 239.7 ±54.4 cm . s−2 (P<0.01). The peak filling velocity during atrial contraction (peak A) did not change (79.7 ±6.3 cm .s−1 vs 74.1±4.7 cm.s−1;P=NS). The ratio peak E/peak A decreasedfrom 1.19±0.06 to 0.85 ± 0.04 (P < 0.01) during haemodialysis. The results provide further evidence for the pronounced preload-dependence of Doppler indices of left ventricular diastolic functio

    A tilted grating interferometer for full vector field differential x-ray phase contrast tomography

    Full text link
    We report on a setup for differential x-ray phase-contrast imaging and tomography, that measures the full 2D phase-gradient information. The setup uses a simple one-dimensional x-ray grating interferometer, in which the grating structures of the interferometer are oriented at a tilt angle with respect to the sample rotation axis. In such a configuration, the differential phase images from opposing tomography projections can be combined to yield both components of the gradient vector. We show how the refractive index distribution as well as its x, y, and z gradient components can be reconstructed directly from the recorded projection data. The method can equally well be applied at conventional x-ray tube sources, to analyzer based x-ray imaging or neutron imaging. It is demonstrated with measurements of an x-ray phantom and a rat brain using synchrotron radiation

    Characterizing near-surface firn using the scattered signal component of the glacier surface return from airborne radio-echo sounding

    Get PDF
    We derive the scattered component (hereafter referred to as the incoherent component) of glacier surface echoes from airborne radio-echo sounding measurements over Devon Ice Cap, Arctic Canada, and compare the scattering distribution to firn stratigraphy observations from ground-based radar data. Low scattering correlates to laterally homogeneous firn above 1800m elevation containing thin, flat, and continuous ice layers and below 1200m elevation where firn predominantly consists of ice. Increased scattering between elevations of 1200-1800m corresponds to firn with inhomogeneous, undulating ice layers. No correlation was found to surface roughness and its theoretical incoherent backscattering values. This indicates that the scattering component is mainly influenced by the near-surface firn stratigraphy, whereas surface roughness effects are minor. Our results suggest that analyzing the scattered signal component of glacier surface echoes is a promising approach to characterize the spatial heterogeneity of firn that is affected by melting and refreezing processes.This work was supported by grants from UK NERC (NE/K004999), NASA (13-ICEE13-00018), NSERC (Discovery Grant/Northern Research Supplement), Alberta Innovates Technology Futures, the CRYSYS Program (Environment Canada), and a University of Alberta Northern Research Award

    A NWB-based dataset and processing pipeline of human single-neuron activity during a declarative memory task

    Get PDF
    A challenge for data sharing in systems neuroscience is the multitude of different data formats used. Neurodata Without Borders: Neurophysiology 2.0 (NWB:N) has emerged as a standardized data format for the storage of cellular-level data together with meta-data, stimulus information, and behavior. A key next step to facilitate NWB:N adoption is to provide easy to use processing pipelines to import/export data from/to NWB:N. Here, we present a NWB-formatted dataset of 1863 single neurons recorded from the medial temporal lobes of 59 human subjects undergoing intracranial monitoring while they performed a recognition memory task. We provide code to analyze and export/import stimuli, behavior, and electrophysiological recordings to/from NWB in both MATLAB and Python. The data files are NWB:N compliant, which affords interoperability between programming languages and operating systems. This combined data and code release is a case study for how to utilize NWB:N for human single-neuron recordings and enables easy re-use of this hard-to-obtain data for both teaching and research on the mechanisms of human memory

    C-reactive protein as a marker for acute coronary syndromes

    Get PDF
    Background For several years, acute coronary syndromes have been perceived as causing the most hospital admissions, and even hospital mortality. The syndrome of unstable angina frequently progresses to acute myocardial infarction but its pathogenesis is poorly understood, and prognosis determination is still problematic. We tested the hypothesis that measurement of the C-reactive protein in patients admitted for chest pain could be a marker for acute coronary syndromes. Methods and Results We studied 110 patients admitted with suspected ischaemic heart disease, but without elevated serum creatine-kinase levels at the time of hospital admission. Patients were subsequently divided into two groups based on their final diagnosis: group 1 comprised patients with unstable angina; group 2 patients with acute myocardial infarction. We measured the C-reactive protein at the time of hospital admission. The concentration of C-reactive protein was elevated in 59% of the patients with a final diagnosis of acute myocardial infarction, and in 5% of the patients with a final diagnosis of unstable angina, (P<0·001). Conclusion This study indicates that C-reactive protein levels measured at the time of admission in patients with suspected ischaemic heart disease could be a marker for acute coronary syndromes, and helpful in identifying patients at high risk for acute myocardial infarction. Measurement of C-reactive protein may have practical clinical significance in the management of patients hospitalized for suspected acute coronary syndrome

    Pulmonary delivery of cationic gold nanoparticles boost antigen-specific CD4+ T Cell Proliferation

    Get PDF
    To address how surface charge affects the fate of potential nanocarriers in the lung, gold nanoparticles (AuNPs) coated with polyvinyl alcohol containing either positively (NH2) or negatively (COOH) charged functional groups were intra-nasally instilled in mice, and their uptake by antigen presenting cell populations (APC) in broncho-alveolar lavage (BAL) fluid, trachea, and lung parenchyma, as well as trafficking to the lung draining lymph nodes (LDLNs) was assessed by flow cytometry. Furthermore, CD4+ T cell proliferation in LDLNs was investigated following instillation. All APC subpopulations preferentially captured positively-charged AuNPs compared to their negatively-charged counterparts. Uptake of AuNPs up-regulated expression of co-stimulatory molecules on all APC populations. Furthermore, positively-charged AuNPs induced enhanced OVA-specific CD4+ T cell stimulation in LDLNs compared to negatively-charged AuNPs, or polymer alone. Our findings demonstrate surface charge as a key parameter determining particle uptake by APC, and down-stream immune responses depend on the presence of particle core-bound polymer

    Extracellular electrophysiological measurements of cooperative signals in astrocytes populations

    Get PDF
    Astrocytes are neuroglial cells that exhibit functional electrical properties sensitive to neuronal activity and capable of modulating neurotransmission. Thus, electrophysiological recordings of astroglial activity are very attractive to study the dynamics of glial signaling. This contribution reports on the use of ultra-sensitive planar electrodes combined with low noise and low frequency amplifiers that enable the detection of extracellular signals produced by primary cultures of astrocytes isolated from mouse cerebral cortex. Recorded activity is characterized by spontaneous bursts comprised of discrete signals with pronounced changes on the signal rate and amplitude. Weak and sporadic signals become synchronized and evolve with time to higher amplitude signals with a quasi-periodic behavior, revealing a cooperative signaling process. The methodology presented herewith enables the study of ionic fluctuations of population of cells, complementing the single cells observation by calcium imaging as well as by patch-clamp techniques.Portuguese Foundation for Science and Technology (FCT) [PTDC/EEI-AUT/5442/2014]; Instituto de Telecomunicacoes [UID/Multi/04326/2013]; Associated Laboratory - Institute of Nanoscience and Nanotechnology [POCI-01-0145-FEDER-016623]; [PTDC/CTM-NAN/3146/2014]info:eu-repo/semantics/publishedVersio
    • …
    corecore