1,422 research outputs found

    Clinical Importance and Epidemiology of Quinolone Resistance

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    The quinolone class of antimicrobial agents is one of most widely used classes of antimicrobial agents in outpatient and inpatient treatment. However, quinolone resistance in gram-positive and gram-negative bacteria has emerged and increased globally. This resistance limits the usefulness of quinolones in clinical practice. The review summarizes mechanisms of quinolone resistance and its epidemiology and implications in the most common clinical settings, urinary tract infections, respiratory tract infections, intraabdominal infections, skin and skin structure infections, and sexually transmitted diseases

    Natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE): a systematic review

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    Background: No published systematic reviews have assessed the natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE). Time to clearance of colonization has important implications for patient care and infection control policy. Methods: We performed parallel searches in OVID Medline for studies that reported the time to documented clearance of MRSA and VRE colonization in the absence of treatment, published between January 1990 and July 2012. Results: For MRSA, we screened 982 articles, identified 16 eligible studies (13 observational studies and 3 randomized controlled trials), for a total of 1,804 non-duplicated subjects. For VRE, we screened 284 articles, identified 13 eligible studies (12 observational studies and 1 randomized controlled trial), for a total of 1,936 non-duplicated subjects. Studies reported varying definitions of clearance of colonization; no study reported time of initial colonization. Studies varied in the frequency of sampling, assays used for sampling, and follow-up period. The median duration of total follow-up was 38 weeks for MRSA and 25 weeks for VRE. Based on pooled analyses, the model-estimated median time to clearance was 88 weeks after documented colonization for MRSA-colonized patients and 26 weeks for VRE-colonized patients. In a secondary analysis, clearance rates for MRSA and VRE were compared by restricting the duration of follow-up for the MRSA studies to the maximum observed time point for VRE studies (43 weeks). With this restriction, the model-fitted median time to documented clearance for MRSA would occur at 41 weeks after documented colonization, demonstrating the sensitivity of the pooled estimate to length of study follow-up. Conclusions: Few available studies report the natural history of MRSA and VRE colonization. Lack of a consistent definition of clearance, uncertainty regarding the time of initial colonization, variation in frequency of sampling for persistent colonization, assays employed and variation in duration of follow-up are limitations of the existing published literature. The heterogeneity of study characteristics limits interpretation of pooled estimates of time to clearance, however, studies included in this review suggest an increase in documented clearance over time, a result which is sensitive to duration of follow-up

    Pseudomoduli Dark Matter

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    We point out that pseudomoduli -- tree-level flat directions that often accompany dynamical supersymmetry breaking -- can be natural candidates for TeV-scale dark matter in models of gauge mediation. The idea is general and can be applied to different dark matter scenarios, including (but not limited to) those of potential relevance to recent cosmic ray anomalies. We describe the requirements for a viable model of pseudomoduli dark matter, and we analyze two example models to illustrate the general mechanism -- one where the pseudomoduli carry Higgsino-like quantum numbers, and another where they are SM singlets but are charged under a hidden-sector U(1)U(1)' gauge group.Comment: 20 pages, refs adde

    Infrared Properties of High Redshift and X-ray Selected AGN Samples

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    The NASA/ISO Key Project on active galactic nuclei (AGN) seeks to better understand the broad-band spectral energy distributions (SEDs) of these sources from radio to X-rays, with particular emphasis on infrared properties. The ISO sample includes a wide variety of AGN types and spans a large redshift range. Two subsamples are considered herein: 8 high-redshift (1 < z < 4.7) quasars; and 22 hard X-ray selected sources. The X-ray selected AGN show a wide range of IR continuum shapes, extending to cooler colors than the optical/radio sample of Elvis et al. (1994). Where a far-IR turnover is clearly observed, the slopes are < 2.5 in all but one case so that non-thermal emission remains a possibility. The highest redshift quasars show extremely strong, hot IR continua requiring ~ 100 solar masses of 500 - 1000 Kelvin dust with ~ 100 times weaker optical emission. Possible explanations for these unusual properties include: reflection of the optical light from material above/below a torus; strong obscuration of the optical continuum; or an intrinsic deficit of optical emission.Comment: 8 pages, 3 figures (2 color), to be published in the Springer Lecture Notes of Physics Series as part of the proceedings for "ISO Surveys of a Dusty Universe," a workshop held at Ringberg Castle, Germany, November 8 - 12, 1999. Requires latex style files for this series: cl2emult.cls, cropmark.sty, lnp.sty, sprmindx.sty, subeqnar.sty (included with submission

    Genes Contributing to Staphylococcus aureus Fitness in Abscess- and Infection-Related Ecologies

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    ABSTRACT Staphylococcus aureus is a leading cause of both community- and hospital-acquired infections that are increasingly antibiotic resistant. The emergence of S. aureus resistance to even last-line antibiotics heightens the need for the development of new drugs with novel targets. We generated a highly saturated transposon insertion mutant library in the genome of S. aureus and used Tn-seq analysis to probe the entire genome, with unprecedented resolution and sensitivity, for genes of importance in infection. We further identified genes contributing to fitness in various infected compartments (blood and ocular fluids) and compared them to genes required for growth in rich medium. This resulted in the identification of 426 genes that were important for S. aureus fitness during growth in infection models, including 71 genes that could be considered essential for survival specifically during infection. These findings highlight novel as well as previously known genes encoding virulence traits and metabolic pathways important for S. aureus proliferation at sites of infection, which may represent new therapeutic targets

    Total carotenoid content, α-carotene and β-carotene, of landrace pumpkins (Cucurbita moschata Duch): A preliminary study

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    AbstractLandrace pumpkins occur in nature and their potential as source of pro-vitamin A may be investigated in order to be used in conventional plant breeding or biofortification programs, aiming to increase the total carotenoids and β-carotene contents. The objective of the study was to determine the total carotenoid, α-carotene, β-carotene and its isomers and contents in two landrace samples (A and B) of raw pumpkins (Cucurbita moschata) to verify its seed production potential. High Performance Liquid Chromatography and UV/Visible spectrophotometry were used to determine α-carotene, β-carotene and its isomers, and total carotenoid contents, respectively. All analyses were carried out in triplicate. The results showed mean total carotenoid contents of 404.98 in sample A, and 234.21μg/g in sample B. The α-carotene contents varied from 67.06 to 72.99μg/g in samples A and B, respectively. All E-β-carotene was the most abundant isomer found varying from 244.22 to 141.95μg/g in samples A and B, respectively. The 9 and 13-Z-β-carotene isomers were still found in low concentrations in both analyzed landrace samples. The content of β-carotene in raw sample A showed to be promising for the production of seeds for cultivation and consumption

    Exosomal αvβ6 integrin is required for monocyte M2 polarization in prostate cancer

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    Therapeutic approaches aimed at curing prostate cancer are only partially successful given the occurrence of highly metastatic resistant phenotypes that frequently develop in response to therapies. Recently, we have described αvβ6, a surface receptor of the integrin family as a novel therapeutic target for prostate cancer; this epithelial-specific molecule is an ideal target since, unlike other integrins, it is found in different types of cancer but not in normal tissues. We describe a novel αvβ6-mediated signaling pathway that has profound effects on the microenvironment. We show that αvβ6 is transferred from cancer cells to monocytes, including β6-null monocytes, by exosomes and that monocytes from prostate cancer patients, but not from healthy volunteers, express αvβ6. Cancer cell exosomes, purified via density gradients, promote M2 polarization, whereas αvβ6 down-regulation in exosomes inhibits M2 polarization in recipient monocytes. Also, as evaluated by our proteomic analysis, αvβ6 down-regulation causes a significant increase in donor cancer cells, and their exosomes, of two molecules that have a tumor suppressive role, STAT1 and MX1/2. Finally, using the Ptenpc−/− prostate cancer mouse model, which carries a prostate epithelial-specific Pten deletion, we demonstrate that αvβ6 inhibition in vivo causes up-regulation of STAT1 in cancer cells. Our results provide evidence of a novel mechanism that regulates M2 polarization and prostate cancer progression through transfer of αvβ6 from cancer cells to monocytes through exosomes

    Update to the Vitamin C, Thiamine and Steroids in Sepsis (VICTAS) protocol: statistical analysis plan for a prospective, multicenter, double-blind, adaptive sample size, randomized, placebo-controlled, clinical trial.

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    BACKGROUND: Observational research suggests that combined therapy with Vitamin C, thiamine and hydrocortisone may reduce mortality in patients with septic shock. METHODS AND DESIGN: The Vitamin C, Thiamine and Steroids in Sepsis (VICTAS) trial is a multicenter, double-blind, adaptive sample size, randomized, placebo-controlled trial designed to test the efficacy of combination therapy with vitamin C (1.5 g), thiamine (100 mg), and hydrocortisone (50 mg) given every 6 h for up to 16 doses in patients with respiratory or circulatory dysfunction (or both) resulting from sepsis. The primary outcome is ventilator- and vasopressor-free days with mortality as the key secondary outcome. Recruitment began in August 2018 and is ongoing; 501 participants have been enrolled to date, with a planned maximum sample size of 2000. The Data and Safety Monitoring Board reviewed interim results at N = 200, 300, 400 and 500, and has recommended continuing recruitment. The next interim analysis will occur when N = 1000. This update presents the statistical analysis plan. Specifically, we provide definitions for key treatment and outcome variables, and for intent-to-treat, per-protocol, and safety analysis datasets. We describe the planned descriptive analyses, the main analysis of the primary end point, our approach to secondary and exploratory analyses, and handling of missing data. Our goal is to provide enough detail that our approach could be replicated by an independent study group, thereby enhancing the transparency of the study. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03509350. Registered on 26 April 2018

    The effectiveness of manual stretching in the treatment of plantar heel pain: a systematic review

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    Background: Plantar heel pain is a commonly occurring foot complaint. Stretching is frequently utilised as a treatment, yet a systematic review focusing only on its effectiveness has not been published. This review aimed to assess the effectiveness of stretching on pain and function in people with plantar heel pain. Methods: Medline, EMBASE, CINAHL, AMED, and The Cochrane Library were searched from inception to July 2010. Studies fulfilling the inclusion criteria were independently assessed, and their quality evaluated using the modified PEDro scale. Results: Six studies including 365 symptomatic participants were included. Two compared stretching with a control, one study compared stretching to an alternative intervention, one study compared stretching to both alternative and control interventions, and two compared different stretching techniques and durations. Quality rating on the modified Pedro scale varied from two to eight out of a maximum of ten points. The methodologies and interventions varied significantly between studies, making meta-analysis inappropriate. Most participants improved over the course of the studies, but when stretching was compared to alternative or control interventions, the changes only reached statistical significance in one study that used a combination of calf muscle stretches and plantar fascia stretches in their stretching programme. Another study comparing different stretching techniques, showed a statistically significant reduction in some aspects of pain in favour of plantar fascia stretching over calf stretches in the short term. Conclusions: There were too few studies to assess whether stretching is effective compared to control or other interventions, for either pain or function. However, there is some evidence that plantar fascia stretching may be more effective than Achilles tendon stretching alone in the short-term. Appropriately powered randomised controlled trials, utilizing validated outcome measures, blinded assessors and long-term follow up are needed to assess the efficacy of stretching
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