The safety of high-dose dexmedetomidine after cardiac surgery: a historical cohort study.

Purpose: The off-label use of dexmedetomidine beyond the monograph-recommended maximum dose of 0.7 µg·kg·hr is common in postoperative cardiac surgical units; however, limited data exist on the association of higher doses and adverse hemodynamic effects. We sought to compare the rate of hypotension or bradycardia in cardiac surgery patients receiving peak infusion doses below and above 0.

Movement Patterns During a Jump-Landing Task in Athletes After Sport-Related Concussion and Healthy Control Individuals.

Context: A relationship between a history of sport-related concussion (SRC) and lower extremity injury has been well established in the literature.

Objective: To determine if biomechanical differences existed during a double-limb jump landing between athletes who had been released to return to play after SRC and healthy matched control individuals.

Design: Cross-sectional study.

Protection of the Queuosine Biosynthesis Enzyme QueF from Irreversible Oxidation by a Conserved Intramolecular Disulfide.

QueF enzymes catalyze the nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ₀) to 7-aminomethyl-7-deazaguanine (preQ₁) in the biosynthetic pathway to the tRNA modified nucleoside queuosine. The QueF-catalyzed reaction includes formation of a covalent thioimide intermediate with a conserved active site cysteine that is prone to oxidation in vivo. Here, we report the crystal structure of a mutant of QueF, which reveals an unanticipated intramolecular disulfide formed between the catalytic Cys55 and a conserved Cys99 located near the active site.

The Relationship Between Humeral Retrotorsion and Shoulder Range of Motion in Baseball Players With an Ulnar Collateral Ligament Tear.

Background: Humeral retrotorsion has been investigated in relation to shoulder range of motion (ROM) in healthy baseball players. Currently, there is limited information on the osseous anatomy and development of ulnar collateral ligament (UCL) tears.

Purpose: To determine the relationship between humeral retrotorsion and shoulder ROM in baseball players with a UCL tear.

Sex Differences in Time to Return-to-Play Progression After Sport-Related Concussion.

Background: Recently, female sports participation has increased, and there is a tendency for women to experience more symptoms and variable presentation after sport-related concussion (SRC). The purpose of this study was to determine whether sex differences exist in time to begin a return-to-play (RTP) progression after an initial SRC.

Hypothesis: After initial SRC, female athletes (11-20 years old) would take longer to begin an RTP progression compared with age-matched male athletes.

Vancouver Transcatheter Aortic Valve Replacement Clinical Pathway: Minimalist Approach, Standardized Care, and Discharge Criteria to Reduce Length of Stay.

We describe the development, implementation, and evaluation of a standardized clinical pathway to facilitate safe discharge home at the earliest time after transfemoral transcatheter aortic valve replacement. Between May 2012 and October 2014, the Heart Team developed a clinical pathway suited to the unique requirements of transfemoral transcatheter aortic valve replacement in contemporary practice. The components included risk-stratified minimalist periprocedure approach, standardized postprocedure care with early mobilization and reconditioning, and criteria-driven discharge home.

Benefits of the Nephros Dual Stage Ultrafilter in Chronic Hemodialysis Patients: Evidence for Improved ESA Responsiveness.

Installation of the Nephros Dual Stage Ultrafilter (DSU) added to a conventional hemodialysis unit to achieve ultrapure dialysate was tested in a group of 23 stable outpatients on chronic hemodialysis. Comparing the 6-month period prior to the installation of the filters (as baseline) to the 6-month period after the installation of the filters, we found a significant 40% reduction in the darbepoetin dose needed to maintain a stable hemoglobin level (p < 0.001).

Hospital performance for pharmacologic venous thromboembolism prophylaxis and rate of venous thromboembolism : a cohort study.

Importance: Hospitalization for acute medical illness is associated with increased risk of venous thromboembolism (VTE). Although efforts designed to increase use of pharmacologic VTE prophylaxis are intended to reduce hospital-associated VTE, whether higher rates of prophylaxis reduce VTE in medical patients is unknown.

Objective: To examine the association between pharmacologic VTE prophylaxis rates and hospital-associated VTE.

A regional anesthesia-based "swing" operating room model reduces non-operative time in a mixed orthopedic inpatient/outpatient population.

Purpose: We recently reported on the efficacy of a new "swing" room model involving two alternating ORs and regional anesthesia in increasing operating room (OR) throughput in a dedicated ambulatory orthopedic surgery facility. The purpose of this study was to evaluate this model in a main OR suite setting with typical mixed inpatient/outpatient cases.

Methods: We conducted a retrospective matched-pair cohort study of 133 upper extremity surgery patients treated in the swing room model under ultrasound-guided brachial plexus blockade.

Structural basis of biological nitrile reduction.

The enzyme QueF catalyzes the reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ(0)) to 7-aminomethyl-7-deazaguanine (preQ(1)), the only nitrile reduction reaction known in biology. We describe here two crystal structures of Bacillus subtilis QueF, one of the wild-type enzyme in complex with the substrate preQ(0), trapped as a covalent thioimide, a putative intermediate in the reaction, and the second of the C55A mutant in complex with the substrate preQ(0) bound noncovalently. The QueF enzyme forms an asymmetric tunnel-fold homodecamer of two head-to-head facing pentameric subunits, harboring 10 active sites at the intersubunit interfaces.

The use of hospice care in end-stage psychiatric patients.

Hospice care is rarely used in end-stage psychiatric patients, yet situations exist where psychiatric intervention is futile and comfort care is the best option. Delusional disorder is rare, typically begins later in life, and has a chronic course that responds poorly to treatment. The prognosis is affected by factors such as chronicity and insight.

Zoospore interspecific signaling promotes plant infection by Phytophthora.

Background: Oomycetes attack a huge variety of economically and ecologically important plants. These pathogens release, detect and respond to signal molecules to coordinate their communal behaviors including the infection process. When signal molecules are present at or above threshold level, single zoospores can infect plants.

Enzyme-catalyzed transfer of a ketone group from an S-adenosylmethionine analogue: a tool for the functional analysis of methyltransferases.

S-adenosylmethionine (AdoMet or SAM)-dependent methyltransferases belong to a large and diverse family of group-transfer enzymes that perform vital biological functions on a host of substrates. Despite the progress in genomics, structural proteomics, and computational biology, functional annotation of methyltransferases remains a challenge. Herein, we report the synthesis and activity of a new AdoMet analogue functionalized with a ketone group.

Zoosporic plant pathogens produce bacterial autoinducer-2 that affects Vibrio harveyi quorum sensing.

The frequent coisolation of bacteria with Phytophthora and Pythium species suggests possible interspecies communication. Zoospore-free fluids (ZFF) from bacteria-free and nutrient-depleted zoospore suspensions were examined to investigate the production of autoinducer-2 (AI-2), a bacterial interspecies signal molecule, by zoosporic oomycetes. ZFF from Phytophthora nicotianae, Phytophthora sojae, and Pythium aphanidermatum triggered luminescence of the Vibrio harve7yi AI-2 reporter, indicating the presence of AI-2 in zoospore extracellular products and the potential of cross-kingdom communication between oomycetes and bacteria.

Chemical methods for the detection of protein N-homocysteinylation via selective reactions with aldehydes.

Elevated blood levels of homocysteine (Hcy), hyperhomocysteinemia or homocystinuria, have been associated with various diseases and conditions. Homocysteine thiolactone (Hcy TL) is a metabolite of Hcy and reacts with amine groups in proteins to form stable amides, homocystamides, or N-homocysteinylated proteins. It has been proposed that protein N-homocysteinylation contributes to the cytotoxicity of elevated Hcy.

A naturally occurring brominated furanone covalently modifies and inactivates LuxS.

Halogenated furanones, a group of natural products initially isolated from marine red algae, are known to inhibit bacterial biofilm formation, swarming, and quorum sensing. However, their molecular targets and the precise mode of action remain elusive. Herein, we show that a naturally occurring brominated furanone covalently modifies and inactivates LuxS (S-ribosylhomocysteine lyase, EC 4.

Mechanistic studies of Bacillus subtilis QueF, the nitrile oxidoreductase involved in queuosine biosynthesis.

The enzyme QueF was recently identified as an enzyme involved in the biosynthesis of queuosine, a 7-deazaguanosine modified nucleoside found in bacterial and eukaryotic tRNA. QueF exhibits sequence homology to the type I GTP cyclohydrolases characterized by FolE, but contrary to the predictions based on sequence analysis the enzyme in fact catalyzes a mechanistically unrelated reaction, the NADPH-dependent reduction of 7-cyano-7-deazaguanine (preQ0) to 7-aminomethyl-7-deazaguanine (preQ1), a late step in the queuosine pathway. The reduction of a nitrile is unprecedented in biology, and we report here characterization and mechanistic studies of the enzyme from Bacillus subtilis.

A riboswitch selective for the queuosine precursor preQ1 contains an unusually small aptamer domain.

A previous bioinformatics-based search for riboswitches yielded several candidate motifs in eubacteria. One of these motifs commonly resides in the 5' untranslated regions of genes involved in the biosynthesis of queuosine (Q), a hypermodified nucleoside occupying the anticodon wobble position of certain transfer RNAs. Here we show that this structured RNA is part of a riboswitch selective for 7-aminomethyl-7-deazaguanine (preQ(1)), an intermediate in queuosine biosynthesis.

Crystallization and preliminary X-ray characterization of the nitrile reductase QueF: a queuosine-biosynthesis enzyme.

QueF (MW = 19.4 kDa) is a recently characterized nitrile oxidoreductase which catalyzes the NADPH-dependent reduction of 7-cyano-7-deazaguanine (preQ0) to 7-aminomethyl-7-deazaguanine, a late step in the biosynthesis of the modified tRNA nucleoside queuosine. Initial crystals of homododecameric Bacillus subtilis QueF diffracted poorly to 8.

From cyclohydrolase to oxidoreductase: discovery of nitrile reductase activity in a common fold.

The enzyme YkvM from Bacillus subtilis was identified previously along with three other enzymes (YkvJKL) in a bioinformatics search for enzymes involved in the biosynthesis of queuosine, a 7-deazaguanine modified nucleoside found in tRNA(GUN) of Bacteria and Eukarya. Genetic analysis of ykvJKLM mutants in Acinetobacter confirmed that each was essential for queuosine biosynthesis, and the genes were renamed queCDEF. QueF exhibits significant homology to the type I GTP cyclohydrolases characterized by FolE.