128 research outputs found

    Whipple's Disease With Neurological Manifestations: Case Report

    Get PDF
    Whipple's disease (WD) is an uncommon multisystem condition caused by the bacillus Tropheryma whipplei. Central nervous system involvement is a classical feature of the disease observed in 20 to 40% of the patients. We report the case of a 62 yeards old man with WD that developed neurological manifestations during its course, and discuss the most usual signs and symptoms focusing on recent diagnostic criteria and novel treatment regimens.622 A342346Whipple, G.H., A hitherto undescribed disease characterized anatomically by deposits of fat and fatty acids in the intestinal and mesenteric lymphatic tissues (1907) Johns Hopkins Hosp Bull, 18, pp. 382-391Marth, T., Raoult, D., Whipple's disease (2003) Lancet, 36, pp. 239-246Gerard, A., Sarrot-Reynauld, F., Liozon, E., Neurologic presentation of Whipple disease: Report of 12 cases and review of the literature (2002) Medicine (Baltimore), 81, pp. 443-457Brown, A.P., Lane, J.C., Murayama, S., Vollmer, D.G., Whipple's disease presenting with isolated neurological symptoms: Case report (1990) J Neurosurg, 73, pp. 623-627Bostwick, D.G., Bensch, K.G., Burke, J.S., Whipple's disease presenting as aortic insufficiency (1981) N Engl J Med, 305, pp. 995-998Raoult, D., A febrile, blood culture-negative endocarditis (1999) Ann Intern Med, 131, pp. 144-146Chan, R.Y., Yannuzzi, L.A., Foster, C.S., Ocular Whipple's disease: Earlier definitive diagnosis (2001) Ophthalmology, 108, pp. 2225-2231Louis, E.D., Lynch, T., Kaufmann, P., Fahn, S., Odel, J., Diagnostic guidelines in central nervous system Whipple's disease (1996) Ann Neurol, 40, pp. 561-568Sieracki, J.C., Whipple's disease: Observations on systemic involvement (1958) Amer Med Asso Arch Pathol, 66, pp. 464-467Anderson, M., Neurology of Whipple's disease (2000) J Neurol Neurosurg Psychiatry, 68, pp. 2-5De Coene, B., Gilliard, C., Indekeu, P., Whipple's disease confined to the central nervous system (1996) Neuroradiology, 38, pp. 325-327Verhagen, W.I.M., Huygen, P.L.M., Dalman, J.E., Schuurmans, M.M.J., Whipple's disease and the central nervous system: A case report and a review of the literature (1996) Clin Neurol Neurosurg, 98, pp. 299-304Feldman, M., Hendler, R.S., Morrison, E.B., Acute meningoencephalitis after withdrawal of antibiotics in Whipple's disease (1980) Ann Intern Med, 93, pp. 709-711Schwartz, M.A., Selhorst, J.B., Ochs, A.L., Oculomasticatory myorhythmia: A unique movement disorder occurring in Whipple's disease (1986) Ann Neurol, 20, pp. 677-683Manzel, K., Tranel, D., Cooper, G., Cognitive and behavioral abnormalities in a case of central nervous system Whipple disease (2000) Arch Neurol, 57, pp. 399-403Halperin, J.J., Landis, D.M., Kleinman, G.M., Whipple's disease of the nervous system (1982) Neurology, 32, pp. 612-617Feurle, G.E., Volk, B., Waldherr, R., Cerebral Whipple's disease with negative jejunal histology (1979) N Engl J Med, 300, pp. 907-908Madoule, P., Ciaudio-Lacroix, C., Halimi, P., Osteoarticular lesions in Whipple's disease, a propos of a destructive form and review of the literature (1985) J Radiol, 66, pp. 345-350Brändle, M., Ammann, P., Spinas, G.A., Relapsing Whipple's disease presenting with hypopituitarism (1999) Clin Endocrinol, 50, pp. 399-403Topper, R., Gartung, C., Block, F., Neurologic complications in inflammatory bowel diseases (2002) Nervenarzt, 73, pp. 489-499Clarke, C.E., Falope, Z.F., Abdelhadi, H.A., Cervical myelopathy caused by Whipple's disease (1998) Neurology, 50, pp. 1505-1506Ramzan, N.N., Loftus, E., Burgart, L.J., Diagnosis and monitoring of Whipple disease by polymerase chain reaction (1997) Ann Intern Med, 126, pp. 520-527Von Herbay, A., Ditton, H.J., Scuhmacher, F., Whipple's disease: Staging and monitoring by cytology and polymerase chain reaction analysis of cerebrospinal fluid (1997) Gastroenterology, 113, pp. 434-441Kremer, S., Besson, G., Bonaz, B., Pasquier, B., Le Bas, J.F., Grand, S., Diffuse lesions in the CNS revealed by MR imaging in a case of Whipple disease (2001) Am J Neuroradiol, 22, pp. 493-495Romanul, F.C., Radvany, J., Rosales, R.K., Whipple's disease confined to the brain: A case studied clinically and pathologically (1977) J Neurol Neurosurg Psychiatry, 40, pp. 901-909Thompson, D.G., Leidingham, J.M., Howard, A.J., Brown, C.L., Meningitis in Whipple's disease (1978) BMJ, 2, pp. 14-15Feurle, G.E., Marth, T., An evaluation of antimicrobial treatment for Whipple's disease: Tetracycline versus trimethoprim-sulfamethoxazole (1994) Dig Dis Sci, 39, pp. 1642-1648Misbah, S.A., Mapstone, N.P., Whipple's disease revisited (2000) J Clin Pathol, 53, pp. 750-755Schnider, P.J., Reisinger, E.C., Berger, T., Krejs, G.J., Auff, E., Treatment guidelines in central nervous system Whipple's disease (1997) Ann Neurol, 41, pp. 561-56

    Mass-Energy and Momentum Extraction by Gravitational Wave Emission in the Merger of Two Colliding Black Holes: The Non-Head-On Case

    Full text link
    We examine numerically the post-merger regime of two Schwarzschild black holes in non head-on collision. Our treatment is made in the realm of non-axisymmetric Robinson-Trautman spacetimes which are appropriate for the description of the system. Characteristic initial data for the system are constructed and the Robinson-Trautman equation is integrated using a numerical code based on the Galerkin spectral method. The collision is planar, restricted to the plane determined by the directions of the two initial colliding black holes, with the net momentum fluxes of gravitational waves confined to this plane. We evaluate the efficiency of mass-energy extraction, the total energy and momentum carried out by gravitational waves and the momentum distribution of the remnant black hole. Our analysis is based on the Bondi-Sachs four momentum conservation laws. Head-on collisions and orthogonal collisions constitute, respectively, upper and lower bounds to the power emission and to the efficiency of mass-energy extraction by gravitational waves. The momentum extraction and the pattern of the momentum fluxes, as a function of the incidence angle, are examined. The momentum extraction characterizes a regime of strong deceleration of the system. The angular pattern of gravitational wave signals is also examined. They are typically bremsstrahlung for early times emission. Gravitational waves are also emitted outside the plane of collision but this component has a zero net momentum flux. The relation between the incidence angle of collision and the exit angle of the remnant closely approximates a relation for inelastic collisions of classical particles in Newtonian dynamics.Comment: 18 pages, 12 Figures, published with slight modifications in Phys. Rev. D 85, 024003 (2012

    Gravito-electromagnetic analogies

    Full text link
    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

    General Relativistic 1+3 Orthonormal Frame Approach Revisited

    Full text link
    The equations of the 1+3 orthonormal frame approach are explicitly presented and discussed. Natural choices of local coordinates are mentioned. A dimensionless formulation is subsequently given. It is demonstrated how one can obtain a number of interesting problems by specializing the general equations. In particular, equation systems for ``silent'' dust cosmological models also containing magnetic Maxwell fields, locally rotationally symmetric spacetime geometries and spatially homogeneous cosmological models are presented. We show that while the 3-Cotton--York tensor is zero for Szekeres dust models, it is nonzero for a generic representative within the ``silent'' class.Comment: 41 pages, uufiles encoded postscript file, submitted to Phys. Rev.

    Phenomenology of the Lense-Thirring effect in the Solar System

    Full text link
    Recent years have seen increasing efforts to directly measure some aspects of the general relativistic gravitomagnetic interaction in several astronomical scenarios in the solar system. After briefly overviewing the concept of gravitomagnetism from a theoretical point of view, we review the performed or proposed attempts to detect the Lense-Thirring effect affecting the orbital motions of natural and artificial bodies in the gravitational fields of the Sun, Earth, Mars and Jupiter. In particular, we will focus on the evaluation of the impact of several sources of systematic uncertainties of dynamical origin to realistically elucidate the present and future perspectives in directly measuring such an elusive relativistic effect.Comment: LaTex, 51 pages, 14 figures, 22 tables. Invited review, to appear in Astrophysics and Space Science (ApSS). Some uncited references in the text now correctly quoted. One reference added. A footnote adde

    Dirac's Observables for the Rest-Frame Instant Form of Tetrad Gravity in a Completely Fixed 3-Orthogonal Gauge

    Get PDF
    We define the {\it rest-frame instant form} of tetrad gravity restricted to Christodoulou-Klainermann spacetimes. After a study of the Hamiltonian group of gauge transformations generated by the 14 first class constraints of the theory, we define and solve the multitemporal equations associated with the rotation and space diffeomorphism constraints, finding how the cotriads and their momenta depend on the corresponding gauge variables. This allows to find quasi-Shanmugadhasan canonical transformation to the class of 3-orthogonal gauges and to find the Dirac observables for superspace in these gauges. The construction of the explicit form of the transformation and of the solution of the rotation and supermomentum constraints is reduced to solve a system of elliptic linear and quasi-linear partial differential equations. We then show that the superhamiltonian constraint becomes the Lichnerowicz equation for the conformal factor of the 3-metric and that the last gauge variable is the momentum conjugated to the conformal factor. The gauge transformations generated by the superhamiltonian constraint perform the transitions among the allowed foliations of spacetime, so that the theory is independent from its 3+1 splittings. In the special 3-orthogonal gauge defined by the vanishing of the conformal factor momentum we determine the final Dirac observables for the gravitational field even if we are not able to solve the Lichnerowicz equation. The final Hamiltonian is the weak ADM energy restricted to this completely fixed gauge.Comment: RevTeX file, 141 page

    Shoulder hemiarthroplasty for fractures of the proximal humerus

    Get PDF
    Proximal humeral fractures were managed with primary hemiarthroplasty in 57 patients, 53 women (93%) and 4 men (7%) aged 51–87 years (mean 72.2). The mean follow-up period was 52 months (range 12–98), and the mean Constant score was 59.2 (range 38–76). Patients were very satisfied (n = 19); satisfied (n = 32) or dissatisfied with the outcome (n = 5). One patient required early revision surgery. Surgical treatment of three- and four-part fractures of the proximal humerus with hemiarthroplasty is a safe and effective approach, the outcome of which appears to be related to the quality of the anatomical reconstruction of the tuberosities

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

    Full text link
    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

    New Brazilian Floristic List Highlights Conservation Challenges

    Get PDF
    A comprehensive new inventory of Brazilian plants and fungi was published just in time to meet a 2010 Convention on Biological Diversity target and offers important insights into this biodiversity's global significance. Brazil is the home to the world's richest flora (40,989 species; 18,932 endemic) and includes two of the hottest hotspots: Mata Atlantica (19,355 species) and Cerrado (12,669 species). Although the total number of known species is one-third lower than previous estimates, the absolute number of endemic vascular plant species is higher than was previously estimated, and the proportion of endemism (56%) is the highest in the Neotropics. This compilation serves not merely to quantify the scale of the challenge faced in conserving Brazil's unique flora but also serves as a key resource to direct action and monitor progress. Similar efforts by other megadiverse countries are urgently required if the 2020 targets of the Convention on Biological Diversity and the Global Strategy for Plant Conservation are to be attained.Ministerio do Meio AmbienteMinisterio do Meio AmbienteCentro Nacional de Conservacao da FloraCentro Nacional de Conservacao da FloraNational Council for Scientific and Technological DevelopmentNational Council for Scientific and Technological DevelopmentBentham and Moxon TrustBentham and Moxon Trus
    corecore