121 research outputs found

    Spielen CRP-Spiegel neben IL-6 und PCT noch eine Rolle für Patienten auf Intensivstationen? / Are circulating levels of CRP compared to IL-6 and PCT still relevant in intensive care unit patients?

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    In der Diagnostik von Infektionen und inflammatorischen Prozessen ist das C-reaktive Protein (CRP) einer der meistverwendeten Parameter, unter anderem aufgrund der geringen Kosten und der schnellen Verfügbarkeit. Im Zuge der letzten Jahre gewannen jedoch andere Entzündungsparameter, wie zum Beispiel das Interleukin 6 (IL-6) oder Procalcitonin (PCT), zunehmend an Bedeutung. Obwohl diese Parameter im klinischen Alltag noch nicht überall etabliert sind, besitzen sie doch wesentliche Vorteile in der Diagnostik und im Verlaufsmonitoring von entzündlichen Erkrankungen. Beispielsweise ist die Erkennung entzündlicher Komplikationen auf Intensivstationen durch erhöhte IL-6 Spiegel 24 bis 48 Stunden vor einer Erhöhung des CRP möglich. Die deutliche Überlegenheit von PCT gegenüber CRP in der Diagnostik von bakteriellen Infektionen und Sepsis begründet sich in der höheren Spezifität des PCT für bakterielle Infektionen. Der PCT-Verlauf ermöglicht daher eine bessere Beurteilung des Therapieerfolges und Krankheitsverlaufs des Patienten und liefert Hinweise auf eine gegebenenfalls erforderliche Therapieumstellung. Daraus ergibt sich die Frage, ob die Messung des CRP-Spiegels durch IL-6 und/oder PCT ersetzt werden kann. In dieser Übersichtsarbeit wird die derzeitige Bedeutung von CRP im Verhältnis zu den neueren Entzündungsparametern in der Diagnostik von bakteriellen Infektionen, im therapeutischen Monitoring und in seiner Aussagekraft bezüglich der Prognose des Patienten auf Intensivstationen dargestellt.C-reactive protein (CRP) currently constitutes one of the most widely used parameters for the diagnosis of infections and inflammatory processes, due to simple methods and low costs. However, in recent years, other parameters, such as interleukin 6 (IL-6) and procalcitonin (PCT), have gained in importance. Although these parameters are presently not established everywhere in clinical routine, they provide significant advantages in the diagnosis and monitoring of inflammatory diseases. For instance, in intensive care, the increase in IL-6 levels may indicate inflammatory complications 24 to 48 h prior to the increase in circulating CRP levels. In contrast to CRP, PCT shows a higher specificity for bacterial infections, which facilitates the diagnosis of bacterial infections and sepsis. Therefore, PCT values provide a better evaluation of prognosis and therapeutic success and of a necessary change in therapy. These points raise the question whether CRP levels should at least in part be replaced by PCT and/or IL-6. Thus, this review seeks to examine the value of CRP in relation to PCT and IL-6 in the diagnosis of bacterial infections, in therapeutic monitoring, and regarding prognosis in critical care patients

    Gravito-electromagnetic analogies

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    We reexamine and further develop different gravito-electromagnetic (GEM) analogies found in the literature, and clarify the connection between them. Special emphasis is placed in two exact physical analogies: the analogy based on inertial fields from the so-called "1+3 formalism", and the analogy based on tidal tensors. Both are reformulated, extended and generalized. We write in both formalisms the Maxwell and the full exact Einstein field equations with sources, plus the algebraic Bianchi identities, which are cast as the source-free equations for the gravitational field. New results within each approach are unveiled. The well known analogy between linearized gravity and electromagnetism in Lorentz frames is obtained as a limiting case of the exact ones. The formal analogies between the Maxwell and Weyl tensors are also discussed, and, together with insight from the other approaches, used to physically interpret gravitational radiation. The precise conditions under which a similarity between gravity and electromagnetism occurs are discussed, and we conclude by summarizing the main outcome of each approach.Comment: 60 pages, 2 figures. Improved version (compared to v2) with some re-write, notation improvements and a new figure that match the published version; expanded compared to the published version to include Secs. 2.3 and

    Searches for Gravitational Waves from Binary Neutron Stars: A Review

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    A new generation of observatories is looking for gravitational waves. These waves, emitted by highly relativistic systems, will open a new window for ob- servation of the cosmos when they are detected. Among the most promising sources of gravitational waves for these observatories are compact binaries in the final min- utes before coalescence. In this article, we review in brief interferometric searches for gravitational waves emitted by neutron star binaries, including the theory, instru- mentation and methods. No detections have been made to date. However, the best direct observational limits on coalescence rates have been set, and instrumentation and analysis methods continue to be refined toward the ultimate goal of defining the new field of gravitational wave astronomy.Comment: 30 pages, 5 Figures, to appear in "Short-Period Binary Stars: Observations, Analyses, and Results", Ed.s Eugene F. Milone, Denis A. Leahy, David W. Hobil

    Changes in the ornithine cycle following ionising radiation cause a cytotoxic conditioning of the culture medium of H35 hepatoma cells

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    Cultured H35 hepatoma cells release a cytotoxic factor in response to irradiation with X-rays. When the conditioned medium from irradiated cells is given to nonirradiated cells, growth is inhibited and followed by cell death, possibly apoptosis, Analysis of the conditioned medium reveals a dramatic change in the ornithine (urea) cycle components after the irradiation. A strong decrease in medium arginine is accompanied with parallel increases in ornithine, citrulline and ammonia. The high level of ammonia appears to be largely responsible for the observed cytotoxicity. The development of hyperammonia by irradiated cells and the related toxicity depend on the radiation dose and the number of cells seeded thereafter for the medium conditioning. Development of cytotoxicity by irradiated cells is completely prevented with the arginase inhibitor L-norvaline, in arginine-deficient medium or when citrulline replaces arginine. These preventive measures result in subtoxic ammonia levels

    General Relativistic Gravity Gradiometry

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    Gravity gradiometry within the framework of the general theory of relativity involves the measurement of the elements of the relativistic tidal matrix, which is theoretically obtained via the projection of the spacetime curvature tensor upon the nonrotating orthonormal tetrad frame of a geodesic observer. The behavior of the measured components of the curvature tensor under Lorentz boosts is briefly described in connection with the existence of certain special tidal directions. Relativistic gravity gradiometry in the exterior gravitational field of a rotating mass is discussed and a gravitomagnetic beat effect along an inclined spherical geodesic orbit is elucidated.Comment: 18 pages, invited contribution to appear in "Relativistic Geodesy: Foundations and Applications", D. Puetzfeld et al. (eds.), 2018; v2: matches version published in: D. Puetzfeld and C. L\"ammerzahl (eds.) "Relativistic Geodesy" (Springer, Cham, 2019), pp. 143-15

    Protective Human Leucocyte Antigen Haplotype, HLA-DRB1*01-B*14, against Chronic Chagas Disease in Bolivia

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    Chronic Chagas disease consists of four different forms categorized on the basis of their clinical manifestations, namely; cardiac, digestive, cardiodigestive and indeterminate. In Latin America, there are 8–10 million seropositive persons who are at risk of, or have already developed serious clinical complications and who have limited access to effective treatment. The cardiac and digestive forms are characterized by tissue damage caused by persistent infection of Trypanosoma cruzi and are thought to be modulated by host immunity. In our large scale screening for chronic Chagas disease in Santa Cruz, Bolivia, hearts and colons of 229 seropositive patients were examined. We found 31.4% of patients had abnormal electrocardiograms (ECGs), 15.7% presented with megacolon, 5.2% had a combination of abnormal ECG and megacolon, and 58.1% were of indeterminate status. Previously, we attempted to ascertain whether parasite genetic polymorphism might account for the differences in clinical manefestations, by analyzing parasite DNA taken from the same study group (with the addition of a further 62 megacolon post-operational patients). We found no relationships between parasite lineages and clinical disease form. The present study reveals that host HLA polymorphisms associate with clinical manifestations of Chagas

    Gravitational-wave research as an emerging field in the Max Planck Society. The long roots of GEO600 and of the Albert Einstein Institute

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    On the occasion of the 50th anniversary since the beginning of the search for gravitational waves at the Max Planck Society, and in coincidence with the 25th anniversary of the foundation of the Albert Einstein Institute, we explore the interplay between the renaissance of general relativity and the advent of relativistic astrophysics following the German early involvement in gravitational-wave research, to the point when gravitational-wave detection became established by the appearance of full-scale detectors and international collaborations. On the background of the spectacular astrophysical discoveries of the 1960s and the growing role of relativistic astrophysics, Ludwig Biermann and his collaborators at the Max Planck Institute for Astrophysics in Munich became deeply involved in research related to such new horizons. At the end of the 1960s, Joseph Weber's announcements claiming detection of gravitational waves sparked the decisive entry of this group into the field, in parallel with the appointment of the renowned relativist Juergen Ehlers. The Munich area group of Max Planck institutes provided the fertile ground for acquiring a leading position in the 1970s, facilitating the experimental transition from resonant bars towards laser interferometry and its innovation at increasingly large scales, eventually moving to a dedicated site in Hannover in the early 1990s. The Hannover group emphasized perfecting experimental systems at pilot scales, and never developed a full-sized detector, rather joining the LIGO Scientific Collaboration at the end of the century. In parallel, the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) had been founded in Potsdam, and both sites, in Hannover and Potsdam, became a unified entity in the early 2000s and were central contributors to the first detection of gravitational waves in 2015.Comment: 94 pages. Enlarged version including new results from further archival research. A previous version appears as a chapter in the volume The Renaissance of General Relativity in Context, edited by A. Blum, R. Lalli and J. Renn (Boston: Birkhauser, 2020

    Urticaria and infections

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    Urticaria is a group of diseases that share a distinct skin reaction pattern. Triggering of urticaria by infections has been discussed for many years but the exact role and pathogenesis of mast cell activation by infectious processes is unclear. In spontaneous acute urticaria there is no doubt for a causal relationship to infections and all chronic urticaria must have started as acute. Whereas in physical or distinct urticaria subtypes the evidence for infections is sparse, remission of annoying spontaneous chronic urticaria has been reported after successful treatment of persistent infections. Current summarizing available studies that evaluated the course of the chronic urticaria after proven Helicobacter eradication demonstrate a statistically significant benefit compared to untreated patients or Helicobacter-negative controls without urticaria (p < 0.001). Since infections can be easily treated some diagnostic procedures should be included in the routine work-up, especially the search for Helicobacter pylori. This review will update the reader regarding the role of infections in different urticaria subtypes

    Measuring the gravitational field in General Relativity: From deviation equations and the gravitational compass to relativistic clock gradiometry

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    How does one measure the gravitational field? We give explicit answers to this fundamental question and show how all components of the curvature tensor, which represents the gravitational field in Einstein's theory of General Relativity, can be obtained by means of two different methods. The first method relies on the measuring the accelerations of a suitably prepared set of test bodies relative to the observer. The second methods utilizes a set of suitably prepared clocks. The methods discussed here form the basis of relativistic (clock) gradiometry and are of direct operational relevance for applications in geodesy.Comment: To appear in "Relativistic Geodesy: Foundations and Application", D. Puetzfeld et. al. (eds.), Fundamental Theories of Physics, Springer 2018, 52 pages, in print. arXiv admin note: text overlap with arXiv:1804.11106, arXiv:1511.08465, arXiv:1805.1067
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