42 research outputs found

    Conservation of Complex Nuclear Localization Signals Utilizing Classical and Non-Classical Nuclear Import Pathways in LANA Homologs of KSHV and RFHV

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    ORF73 latency-associated nuclear antigen (LANA) of the Kaposi's sarcoma-associated herpesvirus (KSHV) is targeted to the nucleus of infected cells where it binds to chromatin and mediates viral episome persistence, interacts with cellular proteins and plays a role in latency and tumorigenesis. A structurally related LANA homolog has been identified in the retroperitoneal fibromatosis herpesvirus (RFHV), the macaque homolog of KSHV. Here, we report the evolutionary and functional conservation of a novel bi-functional nuclear localization signal (NLS) in KSHV and RFHV LANA. N-terminal peptides from both proteins were fused to EGFP or double EGFP fusions to examine their ability to induce nuclear transport of a heterologous protein. In addition, GST-pull down experiments were used to analyze the ability of LANA peptides to interact with members of the karyopherin family of nuclear transport receptors. Our studies revealed that both LANA proteins contain an N-terminal arginine/glycine (RG)-rich domain spanning a conserved chromatin-binding motif, which binds directly to importin β1 in a RanGTP-sensitive manner and serves as an NLS in the importin β1-mediated non-classical nuclear import pathway. Embedded within this domain is a conserved lysine/arginine-(KR)-rich bipartite motif that binds directly to multiple members of the importin α family of nuclear import adaptors in a RanGTP-insensitive manner and serves as an NLS in the classical importin α/β-mediated nuclear import pathway. The positioning of a classical bipartite kr-NLS embedded within a non-classical rg-NLS is a unique arrangement in these viral proteins, whose nuclear localization is critical to their functionality and to the virus life cycle. The ability to interact with multiple import receptors provides alternate pathways for nuclear localization of LANA. Since different import receptors can import cargo to distinct subnuclear compartments, a multifunctional NLS may provide LANA with an increased ability to interact with different nuclear components in its multifunctional role to maintain viral latency

    The Bond and Burden of Caring

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    Ergonomic Analysis of Otologic Surgery: Comparison of Endoscope and Microscope

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    OBJECTIVE: The comparative postural health of surgeons performing endoscopic and microscopic otologic surgeries has been a topic of active debate, with many nascent or anecdotal reports suggesting the latter encourages suboptimal ergonomics. Using inertial body sensors to measure joint angles, this study sought to objectively evaluate and compare the ergonomics of surgeons during endoscopic and microscopic otologic surgeries. STUDY DESIGN: Prospective pilot trial. SETTING: Large, multicenter, academic hospital system. Performed 21 otologic operations (10 endoscopic and 11 microscopic) in November 2020 and January 2021. All attendings were fellowship trained in otology/neurotology. SUBJECTS: Eight otolaryngologists (four attendings and four residents) performing 21 otologic surgeries (11 microscopic and 10 endoscopic). INTERVENTION: Approach to otologic surgery: endoscope or microscope. MAIN OUTCOME MEASURES: Surgeons\u27 neck and back angles while wearing ergonomic sensors affixed to either side of each major joint, mental and physical burdens and pain after each surgery (via modified NASA Task Load Index). RESULTS: Residents\u27 necks (9.54° microscopic vs. -4.79° endoscopic, p = 0.04) and backs (16.48° microscopic vs. 3.66° endoscopic, p = 0.01) were significantly more flexed when performing microscopic surgery than when performing endoscopic surgery, although attending neck and back flexion were comparable during microscopic and endoscopic surgeries. Attendings reported significantly higher pain levels after operating microscopically than after operating endoscopically (0.13 vs. 2.76, p = 0.01). CONCLUSIONS: Residents were found to operate with significantly higher risk back and neck postures (as defined by the validated ergonomic tool, Rapid Entire Body Assessment) when operating microscopically. Attendings reported significantly higher levels of pain after operating microscopically versus endoscopically, suggesting that the suboptimal microscopic postures adopted earlier in training may pose an indelible risk later in a surgeon\u27s career

    In vitro study on the antimicrobial activity of various antibiotics against clinical isolates of Streptococcus pneumoniae from Belgium collected during winter 1998-199936695

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    A total of 205 isolates of Streptococcus pneumoniae obtained from 10 different centres were included in this study. The susceptibilities to penicillin, ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, grepafloxacin, levofloxacin, trovafloxacin, erythromycin, clarithromycin, miocamycin, clindamycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 16.1% [6.8% intermediate (0.12-1 microgram/mL) and 9.3% high-level (&gt; or = 2 micrograms/mL)], cefotaxime insusceptibility (&gt; or = 1 microgram/mL) 12.7%, ciprofloxacine insusceptibility (&gt; or = 2 micrograms/mL) 15.6% with 1.5% of high level resistance (&gt; or = 4 micrograms/mL), erythromycin insusceptibility (&gt; or = 0.5 microgram/mL) 36.1% and tetracycline insusceptibility (&gt; or = 4 micrograms/mL) 22.9%. Decreased susceptibility to cefotaxime was found in 78.8% of the penicillin-insusceptible isolates. No decreased susceptibility was found for gemifloxacin (&gt; or = 0.5 microgram/mL) and trovafloxacin (&gt; or = 1 microgram/mL). Compared to the 1996-1997 surveillance, penicillin, cefotaxime and erythromycin insusceptibility rose by 3.8%, 5.2% and 5.0% respectively, while tetracycline insusceptibility decreased with 8.2%. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Amoxicillin +/- clavulanate, cefotaxime and imipenem were generally 1, 1 and 5 doubling dilutions respectively more potent than penicillin on these isolates. Penicillin, ampicillin and cefuroxime were equally active while cefaclor was generally 5 dilutions less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin +/- clavulanate and imipenem. The penicillin-insusceptible isolates were 36.4%, 27.3% and 3.0% co-insusceptible to erythromycin, erythromycin plus tetracycline and tetracycline respectively. A subpopulation of 52 isolates obtained from children aged &lt; or = 3 years was also studied. Compared to the other isolates we found a statistically significant increase in insusceptibility for penicillin, cefaclor, cefuroxime, erythromycin, clarithromycin and tetracycline while a significant decrease was found for ciprofloxacin</p
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