SDSS J1650+4251: A New Gravitational Lens

We report that the Sloan Digital Sky Survey quasar SDSS J165043.44+425149.3 is gravitationally lensed into two images, based on observations obtained with the WIYN 3.5 m telescope at the Kitt Peak National Observatory. The lensed quasar, at a redshift of z=1.54, appears as two images separated by 1.2" with B-band magnitudes of 17.8 and 20.0. The lensing galaxy is clearly detected in I-band images obtained in 0.3" seeing, after point spread function subtraction of the two quasar images. A strong metal-line absorption system is also identified in the unresolved SDSS spectrum of the double quasar, suggesting a plausible lens redshift of z=0.58. The UBRI flux ratios of the pair vary significantly from 8.5:1 in the blue to 5.4:1 in the red, a difference of 0.5 magnitudes, and may indicate the presence of microlensing in one or both quasar components. The predicted differential time delay between quasar images is on the order of one month, assuming the intervening absorption system is due to the lensing galaxy.Comment: 15 pages (including 4 figures), submitted to the Astronomical Journa

Pyomyositis Diagnosed by Point-of-Care Ultrasound in the Emergency Department

© 2018 Elsevier Inc. Background: Currently, the role of ultrasound in diagnosing superficial abscesses is well validated, however, its role for deep space infections and intramuscular pathology is limited. Distinguishing between simple cellulitis and abscess is critical for emergency physicians (EP), as the treatment is very different. Management of cellulitis relies on antibiotic therapy, whereas abscess treatment requires incision and drainage. It is important that EPs can accurately distinguish between the two entities. Case Report: We report a case of a 41-year-old man with a history of high blood pressure and poorly controlled diabetes who presented with right lateral thigh redness, warmth, and tenderness. A point-of-care ultrasound (POCUS) of the patient\u27s right lateral thigh with a high-frequency linear (8 MHz) ultrasound probe showed a 2.93 × 3.38 × 6.0-cm complex fluid collection deep to the fascial plane, approximately 3.0 cm from the skin surface, that contained mixed echogenicities with posterior acoustic enhancement consistent with an intramuscular abscess of the vastus lateralis. The patient was diagnosed with pyomyositis of his vastus lateralis. He was started on vancomycin and admitted to the surgical service for antibiotic treatment and surgical drainage. Why Should Emergency Physicians Be Aware of This?: This case demonstrates that the use of POCUS by EPs can facilitate the rapid recognition and treatment of a disease that is challenging to diagnose on physical examination and can be potentially life-threatening if missed. EPs can consider performing a POCUS when evaluating skin infections to ensure rapid diagnosis and appropriate medical care for a potentially severe condition

Developing Nurse Scientists by Engaging in Research during Coursework

The nursing research residency provides PhD students the opportunity to participate in research immersion during their coursework. Students can take this course as a 3 credit block or 1 credit per semester for a total of 3 semesters. Each credit has to include at least 30 hours of research activities. Course objectives include: Describe selected research experiences as they work with an identified mentor engaged in research activities. Discuss a unique perspective about participating in research or serving on a team of researchers who are actively engaged in research. Analyze the numerous activities and roles of research team members

A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load

<div><p>Bacterial efflux pumps transport small molecules from the cytoplasm or periplasm outside the cell. Efflux pump activity is typically increased in multi-drug resistant (MDR) pathogens; chemicals that inhibit efflux pumps may have potential for antibiotic development. Using an in-cell screen, we identified three efflux pump modulators (EPMs) from a drug diversity library. The screening platform uses macrophages infected with the human Gram-negative pathogen <i>Salmonella enterica (Salmonella)</i> to identify small molecules that prevent bacterial replication or survival within the host environment. A secondary screen for hit compounds that increase the accumulation of an efflux pump substrate, Hoechst 33342, identified three small molecules with activity comparable to the known efflux pump inhibitor PAβN (Phe-Arg β-naphthylamide). The three putative EPMs demonstrated significant antibacterial activity against <i>Salmonella</i> within primary and cell culture macrophages and within a human epithelial cell line. Unlike traditional antibiotics, the three compounds did not inhibit bacterial growth in standard microbiological media. The three compounds prevented energy-dependent efflux pump activity in <i>Salmonella</i> and bound the AcrB subunit of the AcrAB-TolC efflux system with K_Ds in the micromolar range. Moreover, the EPMs display antibacterial synergy with antimicrobial peptides, a class of host innate immune defense molecules present in body fluids and cells. The EPMs also had synergistic activity with antibiotics exported by AcrAB-TolC in broth and in macrophages and inhibited efflux pump activity in MDR Gram-negative ESKAPE clinical isolates. Thus, an in-cell screening approach identified EPMs that synergize with innate immunity to kill bacteria and have potential for development as adjuvants to antibiotics.</p></div

The three hit compounds decrease bacterial load of <i>Salmonella</i> in mammalian cells.

<p>(A-C) Monitoring of bacterial load by GFP (SAFIRE) or CFU in RAW264.7 cells. (A) Representative micrographs of cells in 96-well plates infected with <i>sifB</i>::<i>GFP Salmonella</i>. Two hours after infection cells were treated with the indicated compound [25 μM] for 16 hours. (B) Dose response curve for SAFIRE and (C) CFU; keys includes IC₅₀ values. (D-E) Monitoring of bacterial load by GFP (SAFIRE) in HeLa cells infected with <i>Salmonella</i> expressing <i>rpsM</i>::<i>GFP</i> and treated with the indicated compound [25 μM]. (F) Monitoring of bacterial load by CFU in BMDMs treated with compounds [25 μM]. Mean and SEM from three independent biological replicates. The nonlinear curve fitting (B, C) is constrained using uninfected cells as the minimum and DMSO-treated cells as the maximum. (E, F) * <i>p</i> < 0.05; ** <i>p</i> < 0.01, *** <i>p</i> < 0.001 compared to DMSO by one-way ANOVA with Dunnett’s post-test.</p

EPMs do not disrupt bacterial inner or outer membranes.

<p>(A,B) <i>Salmonella</i> treated with DMSO or EPMs [100 μM] but not CCCP [1 mM] acquire TMRM staining within 30 minutes. (A) Representative data from one of three independent experiments. (B) Median fluorescence intensity from three experiments normalized to unstained control (0). (C) Disk diffusion assays; the radius of the zone of growth inhibition after 16 hours of exposure to compound across a dose range. Black lines, semilog fit for the combined antibiotic data; gray lines, semilog fit for CCCP and PAβN; dotted lines, limit of detection (disk radius). Average of two measurements from each image captured from one experiment representative of two independent experiments. (D,E) Nitrocefin access to the periplasm as monitored by nitrocefin [100 μM] hydrolysis in the presence of the indicated concentrations of compounds. (D) Absorbance 486 nm of <i>bla+ Salmonella</i> normalized to <i>bla- Salmonella</i>. Data is representative of at least two independent biological replicates. (E) Slope of the linear region of the A₄₈₆ plot from at least three experiments. Data is normalized to A₄₈₆/minute. * <i>p</i> < 0.05, *** <i>p</i> < 0.001, **** <i>p</i> < 0.0001 by one-way ANOVA with Dunnett’s post-test.</p