2,396 research outputs found

    Preferential Adhesion of Urethral Bacteria from a Mixed Population to a Urinary Catheter

    Get PDF
    The ability of uropathogens to adhere to catheters and subsequently colonize the urinary mucosa leads to urinary tract infections which afflict a large patient population. In vitro studies were carried out whereby Escherichia coli Hu734 (water contact angle 12 °) and Enterococcus faecalis (19°) were found to be highly adhesive to silicone latex urinary catheters. The addition of one of four Lactobacillus sp., with water contact angles ranging from 19-105 °, to the suspending fluid caused a 60-86% reduction in pathogen adhesion with a significant effect against E. coli, the organism most commonly found to infect the urinary tract. Lactobacilli were significantly effective at displacing uropathogens and preventing their adhesion. Hydrophobic lactobacilli (105 °) were particularly effective at preventing enterococci from adhering from the surface, while more hydrophilic lactobacilli (19-54 °) were most effective at displacing enterococci. The effective competition with four strains of lactobacilli was achieved even when they only comprised 0.1%-7% of the total organisms on the surfaces. These studies demonstrate the important role which the indigenous urethral flora could play in inhibiting the initial attachment of pathogens to catheter surfaces

    Protein translocation channel of mitochondrial inner membrane and matrix-exposed import motor communicate via two-domain coupling protein

    Get PDF
    The majority of mitochondrial proteins are targeted to mitochondria by N-terminal presequences and use the TIM23 complex for their translocation across the mitochondrial inner membrane. During import, translocation through the channel in the inner membrane is coupled to the ATP-dependent action of an Hsp70-based import motor at the matrix face. How these two processes are coordinated remained unclear. We show here that the two domain structure of Tim44 plays a central role in this process. The N-terminal domain of Tim44 interacts with the components of the import motor, whereas its C-terminal domain interacts with the translocation channel and is in contact with translocating proteins. Our data suggest that the translocation channel and the import motor of the TIM23 complex communicate through rearrangements of the two domains of Tim44 that are stimulated by translocating proteins

    Imaging Granulomatous Lesions with Optical Coherence Tomography

    Get PDF
    www.karger.com/cde This is an Open Access article licensed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License (www.karger.com/OA-license), applicable to the online version of the article only. Distribution for non-commercial purposes only

    Complementary Domains of Retinoic Acid Production and Degradation in the Early Chick Embryo

    Get PDF
    AbstractExcess retinoids as well as retinoid deprivation cause abnormal development, suggesting that retinoid homeostasis is critical for proper morphogenesis. RALDH-2 and CYP26, two key enzymes that carry out retinoic acid (RA) synthesis and degradation, respectively, were cloned from the chick and show significant homology with their orthologs in other vertebrates. Expression patterns of RALDH-2 and CYP26 genes were determined in the early chick embryo by in situ hybridization. During gastrulation and neurulation RALDH-2 and CYP26 were expressed in nonoverlapping regions, with RALDH-2 transcripts localized to the presumptive presomitic and lateral plate mesoderm and CYP26 mRNA to the presumptive mid- and forebrain. The two domains of expression were separated by an approximately 300-μm-wide gap, encompassing the presumptive hindbrain. In the limb region, a similar spatial segregation of RALDH-2 and CYP26 expression was found at stages 14 and 15. Limb region mesoderm expressed RALDH-2, whereas the overlying limb ectoderm expressed CYP26. RA-synthesizing and -degrading enzymatic activities were measured biochemically in regions expressing RALDH-2 or CYP26. Regions expressing RALDH-2 generated RA efficiently from precursor retinal but degraded RA only inefficiently. Conversely, tissue expressing CYP26 efficiently degraded but did not synthesize RA. Localized regions of RA synthesis and degradation mediated by these two enzymes may therefore provide a mechanism to regulate RA homeostasis spatially in vertebrate embryos

    Potential Immunotherapy for Prostate Cancer: Recombinant Bacille Calmette-Guerin Expressing Prostate Specific Molecules

    Get PDF
    Purpose: The emergence of prostate cancer as a major health issue and the absence of curative treatment for metastatic disease requires the development of new treatment modalities. Prostate specific antigen (PSA) and prostate-specific membrane antigen (PSMA) are possible targets for prostate cancer immunotherapy. We have previously shown that PSA and PSMA can be expressed in recombinant bacille Calmette-Guérin (BCG) strains.Methods: The in vivo immunogenicity of the prostate-specific proteins produced by this recombinant BCG strain were examined by detection of specific antibody responses and delayed-type hypersensitivity (DTH) responses in mice vaccinated with these strains. These immune responses were compared with those of control mice vaccinated with phosphate buffered saline diluent or soluble PSA or PSMA.Results: Mice vaccinated with rBCG-PSA developed low levels of anti-PSA antibodies and strong DTH to PSA.  Mice vaccinated with rBCG-PSMA developed strong DTH to PSMA and no anti-PSMA antibodies. Conclusions: We conclude that recombinant BCG expressing PSA or PSMA induce strong cellular immune responses to these antigens. We propose that the innate adjuvant capacity of BCG could help stimulate a specific immune response against prostate-specific proteins produced by the bacteria, which in turn, could lead to the eradication of undetected metastatic prostate cancer cells in post-surgical patients

    Seismic surface wave focal spot imaging : numerical resolution experiments

    Get PDF
    Numerical experiments of seismic wave propagation in a laterally homogeneous layered medium explore subsurface imaging at subwavelength distances for dense seismic arrays. We choose a time-reversal approach to simulate fundamental mode Rayleigh surface wavefields that are equivalent to the cross-correlation results of three-component ambient seismic field records. We demonstrate that the synthesized 2-D spatial autocorrelation fields in the time domain support local or so-called focal spot imaging. Systematic tests involving clean isotropic surface wavefields but also interfering body wave components and anisotropic incidence assess the accuracy of the phase velocity and dispersion estimates obtained from focal spot properties. The results suggest that data collected within half a wavelength around the origin is usually sufficient to constrain the used Bessel functions models. Generally, the cleaner the surface wavefield the smaller the fitting distances that can be used to accurately estimate the local Rayleigh wave speed. Using models based on isotropic surface wave propagation we find that phase velocity estimates from vertical-radial component data are less biased by P-wave energy compared to estimates obtained from vertical-vertical component data, that even strong anisotropic surface wave incidence yields phase velocity estimates with an accuracy of 1 per cent or better, and that dispersion can be studied in the presence of noise. Estimates using a model to resolve potential medium anisotropy are significantly biased by anisotropic surface wave incidence. The overall accurate results obtained from near-field measurements using isotropic medium assumptions imply that dense array seismic Rayleigh wave focal spot imaging can increase the depth sensitivity compared to ambient noise surface wave tomography. The analogy to elastography focal spot medical imaging implies that a high station density and clean surface wavefields support subwavelength resolution of lateral medium variations.Peer reviewe

    Hidradenitis suppurativa is associated with higher heart rate but not atrial fibrillation: A comparative cross-sectional study of 462 individuals with hidradenitis suppurativa in Denmark

    Get PDF
    Hidradenitis suppurativa (HS) is a chronic inflammatory dermatological disease with inflammatory mechanisms overlapping those of psoriasis, and both diseases have been associated with cardiovascular risk factors i.e. smoking and metabolic syndrome. Two studies have recently linked psoriasis with Atrial Fibrillation (AF). AF is the most frequently occurring cardiac arrhythmia in the general population and is typically accompanied by increased heart rate. Both AF and heart rate are linked with inflammation.The aim of the study was to investigate a potential association between HS and increased heart rate as well as AF.We performed a comparative cross-sectional study using digital measurements of heart rate and resting 12-lead electrocardiography (ECG) in combination with self-reported information when diagnosing AF.Our study comprised 32 individuals with HS from the hospital (the hospital HS group), 430 from the general population HS group (the population HS group), and 20,780 controls. Age and sex adjusted analysis demonstrated a significantly higher heart rate in the HS groups vs. controls (15% (range: 8-23%) higher for the hospital HS group and 4% (2-5%) higher for the population HS group). We found no association between HS and AF (P=0.1670). </p

    Reflection ciphers

    Get PDF
    This paper investigates ciphers where the set of encryption functions is identical to the set of decryption functions, which we call reflection ciphers. Equivalently, there exists a permutation P, named the coupling permutation, such that decryption under k corresponds to encryption under P(k). We study the necessary properties for this coupling permutation.Special care has to be taken of some related-key distinguishers since, in the context of reflection ciphers, they may provide attacks in the single-key setting.We then derive some criteria for constructing secure reflection ciphers and analyze the security properties of different families of coupling permutations. Finally, we concentrate on the case of reflection block ciphers and, as an illustration, we provide concrete examples of key schedules corresponding to several coupling permutations, which lead to new variants of the block cipher PRINCE
    corecore