191 research outputs found

    Down-regulation of CD46 by Piliated Neisseria gonorrhoeae

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    Human membrane cofactor protein (CD46) protects host cells against complement attack and may function as a receptor for pathogenic Neisseriae. We assessed CD46 expression in the human cervical cell line ME-180 after exposure to Neisseria gonorrhoeae. Piliated but not nonpiliated gonococci adhered to cells and produced up to an 80% reduction in CD46 surface expression by 6 h that persisted for at least 24 h. This response required a minimum multiplicity of infection of 10 and was not prevented by antibodies to CD46. CD46 down-regulation was not attributable to intracellular retention or a global or specific shutdown of mRNA or protein synthesis. Substantial quantities of CD46 were found in the supernatants, indicating a specific shedding of this protein. Adherent gonococci lacking the pilus retraction protein PilT did not down-regulate CD46 but de-repression of pilT expression restored CD46 down-regulation. After experimental infection of human volunteers with a gonococcal variant incapable of inducing CD46 down-regulation, variants of this strain were reisolated that exhibited CD46 down-regulation. Pilus-mediated interactions of gonococci with human epithelial cells results in a pathogen-induced manipulation of the host cell environment in which a membrane protein is removed from epithelial cells by liberation into the surrounding milieu

    A comparison between endoscopic ultrasound-guided rendezvous and percutaneous biliary drainage after failed ERCP for malignant distal biliary obstruction

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    Background and study Aims: Selective biliary cannulation is unsuccessful in 5 % to 10 % of patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) for malignant distal biliary obstruction (MDBO). Percutaneous biliary drainage (PBD) has been the gold standard, but endoscopic ultrasound guided rendezvous (EUSr) have been increasingly used for biliary decompression in this patient population. Our aim was to compare the initial success rate, long-term efficacy, and safety of PBD and EUSr in relieving MDBO after failed ERC Patients and methods: A retrospective study involving 50 consecutive patients who had an initial failed ERCP for MDBO. Twenty-five patients undergoing EUSr between 2008 – 2014 were compared to 25 patients who underwent PBD immediately prior to the introduction of EUSr at our center (2002 – 2008). Comparisons were made between the two groups with regard to technical success, duration of hospital stay and adverse event rates after biliary decompression. Results: The mean age at presentation was 66.5 (± 12.6 years), 28 patients (54.9 %) were female. The etiology of MDBO was pancreaticobiliary malignancy in 44 (88 %) and metastatic disease in 6 (12 %) cases. Biliary drainage was technically successful by EUSr in 19 (76 %) cases and by PBD in 25 (100 %) (P = 0.002). Median length of hospital stay after initial drainage was 1 day in the EUSr group vs 5 days in PBD group (P = 0.02). Repeat biliary intervention was required for 4 patients in the EUSr group and 15 in the PBD group (P = 0.001). Conclusions: Initial technical success with EUSr was significantly lower than with PBD, however when EUSr was successful, patients had a significantly shorter post-procedure hospital stay and required fewer follow-up biliary interventions. Meeting presentations: Annual Digestive Diseases Week 201

    Eruptions at Lone Star geyser, Yellowstone National Park, USA: 2. Constraints on subsurface dynamics

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    Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 119 (2014): 8688–8707, doi:10.1002/2014JB011526.We use seismic, tilt, lidar, thermal, and gravity data from 32 consecutive eruption cycles of Lone Star geyser in Yellowstone National Park to identify key subsurface processes throughout the geyser's eruption cycle. Previously, we described measurements and analyses associated with the geyser's erupting jet dynamics. Here we show that seismicity is dominated by hydrothermal tremor (~5–40 Hz) attributed to the nucleation and/or collapse of vapor bubbles. Water discharge during eruption preplay triggers high-amplitude tremor pulses from a back azimuth aligned with the geyser cone, but during the rest of the eruption cycle it is shifted to the east-northeast. Moreover, ~4 min period ground surface displacements recur every 26 ± 8 min and are uncorrelated with the eruption cycle. Based on these observations, we conclude that (1) the dynamical behavior of the geyser is controlled by the thermo-mechanical coupling between the geyser conduit and a laterally offset reservoir periodically filled with a highly compressible two-phase mixture, (2) liquid and steam slugs periodically ascend into the shallow crust near the geyser system inducing detectable deformation, (3) eruptions occur when the pressure decrease associated with overflow from geyser conduit during preplay triggers an unstable feedback between vapor generation (cavitation) and mass discharge, and (4) flow choking at a constriction in the conduit arrests the runaway process and increases the saturated vapor pressure in the reservoir by a factor of ~10 during eruptions.Funding for USGS team members was provided by the USGS Volcano Hazards Program. R. Sohn's participation was supported by the WHOI Green Technology Program. M. Manga, L. Karlstrom and M. Rudolph did receive salary from the National Science Foundation to spend time on this project.2015-06-0

    Salty or Sweet? Nutritional Quality, Consumption, and Cost of Snacks Served in Afterschool Programs

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    Snacks served in afterschool programs (ASPs, 3–6pm) represent an important opportunity to promote healthy eating. ASP policies suggest a fruit/vegetable is served daily, while sugar-sweetened foods/beverages and artificially-flavored snacks are eliminated. Limited information exists on the types of snacks served in ASPs, if snacks meet existing nutrition policies, whether children eat the snacks, and their cost

    A Potent and Broad Neutralization of SARS-Cov-2 Variants of Concern by DARpins

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    We report the engineering and selection of two synthetic proteins-FSR16m and FSR22-for the possible treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. FSR16m and FSR22 are trimeric proteins composed of DARPin SR16m or SR22 fused with a T4 foldon. Despite selection by a spike protein from a now historical SARS-CoV-2 strain, FSR16m and FSR22 exhibit broad-spectrum neutralization of SARS-CoV-2 strains, inhibiting authentic B.1.351, B.1.617.2 and BA.1.1 viruses, with respective I

    Utilization of Mid-Thigh Magnetic Resonance Imaging to Predict Lean Body Mass and Knee Extensor Strength in Obese Adults

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    PurposeTo train and test a machine learning model to automatically measure mid-thigh muscle cross-sectional area (CSA) to provide rapid estimation of appendicular lean mass (ALM) and predict knee extensor torque of obese adults.MethodsObese adults [body mass index (BMI) = 30–40 kg/m2, age = 30–50 years] were enrolled for this study. Participants received full-body dual-energy X-ray absorptiometry (DXA), mid-thigh MRI, and completed knee extensor and flexor torque assessments via isokinetic dynamometer. Manual segmentation of mid-thigh CSA was completed for all MRI scans. A convolutional neural network (CNN) was created based on the manual segmentation to develop automated quantification of mid-thigh CSA. Relationships were established between the automated CNN values to the manual CSA segmentation, ALM via DXA, knee extensor, and flexor torque.ResultsA total of 47 obese patients were enrolled in this study. Agreement between the CNN-automated measures and manual segmentation of mid-thigh CSA was high (>0.90). Automated measures of mid-thigh CSA were strongly related to the leg lean mass (r = 0.86, p < 0.001) and ALM (r = 0.87, p < 0.001). Additionally, mid-thigh CSA was strongly related to knee extensor strength (r = 0.76, p < 0.001) and moderately related to knee flexor strength (r = 0.48, p = 0.002).ConclusionCNN-measured mid-thigh CSA was accurate compared to the manual segmented values from the mid-thigh. These values were strongly predictive of clinical measures of ALM and knee extensor torque. Mid-thigh MRI may be utilized to accurately estimate clinical measures of lean mass and function in obese adults

    Detection of SARS‐CoV‐2 in respiratory samples from cats in the UK associated with human‐to‐cat transmission

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    Objectives: The aim of the study was to find evidence of SARS‐CoV‐2 infection in UK cats. Design: Tissue samples were tested for SARS‐CoV‐2 antigen using immunofluorescence and for viral RNA by in situ hybridisation. A set of 387 oropharyngeal swabs that had been submitted for routine respiratory pathogen testing was tested for SARS‐CoV‐2 RNA using reverse transcriptase quantitative PCR. Results: Lung tissue collected post‐mortem from cat 1 tested positive for both SARS‐CoV‐2 nucleocapsid antigen and RNA. SARS‐CoV‐2 RNA was detected in an oropharyngeal swab collected from cat 2 that presented with rhinitis and conjunctivitis. High throughput sequencing of the viral genome revealed five single nucleotide polymorphisms (SNPs) compared to the nearest UK human SARS‐CoV‐2 sequence, and this human virus contained eight SNPs compared to the original Wuhan‐Hu‐1 reference sequence. An analysis of the viral genome of cat 2 together with nine other feline‐derived SARS‐CoV‐2 sequences from around the world revealed no shared cat‐specific mutations. Conclusions: These findings indicate that human‐to‐cat transmission of SARS‐CoV‐2 occurred during the COVID‐19 pandemic in the UK, with the infected cats developing mild or severe respiratory disease. Given the ability of the new coronavirus to infect different species, it will be important to monitor for human‐to‐cat, cat‐to‐cat and cat‐to‐human transmission
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