298 research outputs found
Fulminant Leptospirosis (Weil's disease) in an urban setting as an overlooked cause of multiorgan failure: a case report
<p>Abstract</p> <p>Introduction</p> <p>Leptospirosis has recently come to international attention as a globally important re-emerging infectious disease. Our case is unusual given the season, location and setting in which leptospirosis occurred. According to the New York City Board of Health, there were only two other cases of leptospirosis in New York City in the year that our patient was diagnosed.</p> <p>Case presentation</p> <p>A 49-year-old healthy Chinese man presented to our hospital with sepsis and multiorgan failure. The patient did not respond to antibiotics and his multiorgan failure worsened. His workup did not show any significant findings except for a positive nasopharyngeal swab result for influenza A. Later the patient developed hemoptysis with evidence of bilateral infiltrates on radiography. His status mildly improved after he was started on steroids. Eventually, a microagglutination test confirmed the presence of antibodies against <it>Leptospira icterohaemorrhagiae. </it>The patient subsequently recovered after a course of intravenous antibiotics.</p> <p>Conclusion</p> <p>The case of fulminant leptospirosis presented here should serve to alert health care providers and the general public to the clinical importance of this severe, sometimes fatal, disease. Leptospirosis should be considered early in the diagnosis of any patient with acute, non-specific febrile illness with multiorgan system involvement or high fever in a returning traveler. In addition, not only should it be considered in tropical and rural areas between late summer to early fall, but also in any location or time if the risk factors are present.</p
Hemocompatibility of Silicon-Based Substrates for Biomedical Implant Applications
Silicon membranes with highly uniform nanopore sizes fabricated using microelectromechanical systems (MEMS) technology allow for the development of miniaturized implants such as those needed for renal replacement therapies. However, the blood compatibility of silicon has thus far been an unresolved issue in the use of these substrates in implantable biomedical devices. We report the results of hemocompatibility studies using bare silicon, polysilicon, and modified silicon substrates. The surface modifications tested have been shown to reduce protein and/or platelet adhesion, thus potentially improving biocompatibility of silicon. Hemocompatibility was evaluated under four categories—coagulation (thrombin–antithrombin complex, TAT generation), complement activation (complement protein, C3a production), platelet activation (P-selectin, CD62P expression), and platelet adhesion. Our tests revealed that all silicon substrates display low coagulation and complement activation, comparable to that of Teflon and stainless steel, two materials commonly used in medical implants, and significantly lower than that of diethylaminoethyl (DEAE) cellulose, a polymer used in dialysis membranes. Unmodified silicon and polysilicon showed significant platelet attachment; however, the surface modifications on silicon reduced platelet adhesion and activation to levels comparable to that on Teflon. These results suggest that surface-modified silicon substrates are viable for the development of miniaturized renal replacement systems
Measurement of the top quark mass using the matrix element technique in dilepton final states
We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84 GeV
Radio emission from Supernova Remnants
The explosion of a supernova releases almost instantaneously about 10^51 ergs
of mechanic energy, changing irreversibly the physical and chemical properties
of large regions in the galaxies. The stellar ejecta, the nebula resulting from
the powerful shock waves, and sometimes a compact stellar remnant, constitute a
supernova remnant (SNR). They can radiate their energy across the whole
electromagnetic spectrum, but the great majority are radio sources. Almost 70
years after the first detection of radio emission coming from a SNR, great
progress has been achieved in the comprehension of their physical
characteristics and evolution. We review the present knowledge of different
aspects of radio remnants, focusing on sources of the Milky Way and the
Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief
overview of theoretical background, analyze morphology and polarization
properties, and review and critical discuss different methods applied to
determine the radio spectrum and distances. The consequences of the interaction
between the SNR shocks and the surrounding medium are examined, including the
question of whether SNRs can trigger the formation of new stars. Cases of
multispectral comparison are presented. A section is devoted to reviewing
recent results of radio SNRs in the Magellanic Clouds, with particular emphasis
on the radio properties of SN 1987A, an ideal laboratory to investigate
dynamical evolution of an SNR in near real time. The review concludes with a
summary of issues on radio SNRs that deserve further study, and analyzing the
prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure
Ratio of the Isolated Photon Cross Sections at \sqrt{s} = 630 and 1800 GeV
The inclusive cross section for production of isolated photons has been
measured in \pbarp collisions at GeV with the \D0 detector at
the Fermilab Tevatron Collider. The photons span a transverse energy ()
range from 7-49 GeV and have pseudorapidity . This measurement is
combined with to previous \D0 result at GeV to form a ratio
of the cross sections. Comparison of next-to-leading order QCD with the
measured cross section at 630 GeV and ratio of cross sections show satisfactory
agreement in most of the range.Comment: 7 pages. Published in Phys. Rev. Lett. 87, 251805, (2001
Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial
Contains fulltext :
96247.pdf (publisher's version ) (Open Access)BACKGROUND: The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences.Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. METHODS/DESIGN: This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning).Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory.Study parameters are clinical consolidation, radiological consolidation evaluated by CT-scanning, functional status of the wrist, including assessment by means of the patient rated wrist evaluation (PRWE) questionnaire and quality of life using SF-36 health survey questionnaire.Primary endpoint is number of scaphoid unions at six weeks, secondary endpoints are time interval to clinical and radiological consolidation, number of non-unions, functional status at 52 weeks and non-adherence to the treatment protocol. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR2064
Effects of Protein Deficiency on Perinatal and Postnatal Health Outcomes
There are a variety of environmental insults that can occur during pregnancy which cause low birth weight and poor fetal health outcomes. One such insult is maternal malnutrition, which can be further narrowed down to a low protein diet during gestation. Studies show that perinatal protein deficiencies can impair proper organ growth and development, leading to long-term metabolic dysfunction. Understanding the molecular mechanisms that underlie how this deficiency leads to adverse developmental outcomes is essential for establishing better therapeuticstrategies that may alleviate or prevent diseases in later life. This chapter reviews how perinatal protein restriction in humans and animals leads to metabolic disease, and it identifies the mechanisms that have been elucidated, to date. These include alterations in transcriptional and epigenetic mechanisms, as well as indirect means such as endoplasmic reticulum (ER) stress and oxidative stress. Furthermore, nutritional and pharmaceutical interventions are highlighted to illustrate that the plasticity of the underdeveloped organs during perinatal life can be exploited to prevent onset of long-term metabolic disease
Review of Coronal Oscillations - An Observer's View
Recent observations show a variety of oscillation modes in the corona. Early
non-imaging observations in radio wavelengths showed a number of fast-period
oscillations in the order of seconds, which have been interpreted as fast
sausage mode oscillations. TRACE observations from 1998 have for the first time
revealed the lateral displacements of fast kink mode oscillations, with periods
of ~3-5 minutes, apparently triggered by nearby flares and destabilizing
filaments. Recently, SUMER discovered with Doppler shift measurements loop
oscillations with longer periods (10-30 minutes) and relatively short damping
times in hot (7 MK) loops, which seem to correspond to longitudinal slow
magnetoacoustic waves. In addition, propagating longitudinal waves have also
been detected with EIT and TRACE in the lowest density scale height of loops
near sunspots. All these new observations seem to confirm the theoretically
predicted oscillation modes and can now be used as a powerful tool for
``coronal seismology'' diagnostic.Comment: 5 Figure
Laforin, a Dual Specificity Phosphatase Involved in Lafora Disease, Is Present Mainly as Monomeric Form with Full Phosphatase Activity
Lafora Disease (LD) is a fatal neurodegenerative epileptic disorder that presents as a neurological deterioration with the accumulation of insoluble, intracellular, hyperphosphorylated carbohydrates called Lafora bodies (LBs). LD is caused by mutations in either the gene encoding laforin or malin. Laforin contains a dual specificity phosphatase domain and a carbohydrate-binding module, and is a member of the recently described family of glucan phosphatases. In the current study, we investigated the functional and physiological relevance of laforin dimerization. We purified recombinant human laforin and subjected the monomer and dimer fractions to denaturing gel electrophoresis, mass spectrometry, phosphatase assays, protein-protein interaction assays, and glucan binding assays. Our results demonstrate that laforin prevalently exists as a monomer with a small dimer fraction both in vitro and in vivo. Of mechanistic importance, laforin monomer and dimer possess equal phosphatase activity, and they both associate with malin and bind glucans to a similar extent. However, we found differences between the two states' ability to interact simultaneously with malin and carbohydrates. Furthermore, we tested other members of the glucan phosphatase family. Cumulatively, our data suggest that laforin monomer is the dominant form of the protein and that it contains phosphatase activity
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