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Find video protocols related to scientific articles indexed in Pubmed.
Comparing the Catalytic Oxidation of Ethanol at the Solid-Gas and Solid-Liquid Interfaces over Size-Controlled Pt Nanoparticles: Striking Differences in Kinetics and Mechanism.
Nano Lett.
PUBLISHED: 10-24-2014
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Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 °C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ?80 times faster, and the activation energy is ?5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy.
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Application of desorption electrospray ionization mass spectrometry imaging in breast cancer margin analysis.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 09-22-2014
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Distinguishing tumor from normal glandular breast tissue is an important step in breast-conserving surgery. Because this distinction can be challenging in the operative setting, up to 40% of patients require an additional operation when traditional approaches are used. Here, we present a proof-of-concept study to determine the feasibility of using desorption electrospray ionization mass spectrometry imaging (DESI-MSI) for identifying and differentiating tumor from normal breast tissue. We show that tumor margins can be identified using the spatial distributions and varying intensities of different lipids. Several fatty acids, including oleic acid, were more abundant in the cancerous tissue than in normal tissues. The cancer margins delineated by the molecular images from DESI-MSI were consistent with those margins obtained from histological staining. Our findings prove the feasibility of classifying cancerous and normal breast tissues using ambient ionization MSI. The results suggest that an MS-based method could be developed for the rapid intraoperative detection of residual cancer tissue during breast-conserving surgery.
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Serotonin affects movement gain control in the spinal cord.
J. Neurosci.
PUBLISHED: 09-19-2014
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A fundamental challenge for the nervous system is to encode signals spanning many orders of magnitude with neurons of limited bandwidth. To meet this challenge, perceptual systems use gain control. However, whether the motor system uses an analogous mechanism is essentially unknown. Neuromodulators, such as serotonin, are prime candidates for gain control signals during force production. Serotonergic neurons project diffusely to motor pools, and, therefore, force production by one muscle should change the gain of others. Here we present behavioral and pharmaceutical evidence that serotonin modulates the input-output gain of motoneurons in humans. By selectively changing the efficacy of serotonin with drugs, we systematically modulated the amplitude of spinal reflexes. More importantly, force production in different limbs interacts systematically, as predicted by a spinal gain control mechanism. Psychophysics and pharmacology suggest that the motor system adopts gain control mechanisms, and serotonin is a primary driver for their implementation in force production.
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Engineering of novel Staphylococcal Protein A ligands to enable milder elution pH and high dynamic binding capacity.
J Chromatogr A
PUBLISHED: 08-19-2014
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We describe novel Staphylococcal Protein A ligands that enable milder elution pH for use in affinity chromatography. The change in elution pH is the result of point mutations to the protein sequence. Two novel ligands are investigated in this study. The first, designated Z(H18S)4, represents a histidine to serine substitution single mutation. The second, designated Z(H18S, N28A)4, is a double mutant comprising histidine to serine and asparagine to alanine mutations. Both are compared against the unmutated sequence, designated Z4, which is currently utilized in a commercially available Protein A stationary phase for the purification of molecules containing Fc domains. The ligands are coupled to a chromatography support matrix and tested against a panel of antibodies and an Fc fusion protein for elution pH, dynamic binding capacity, step-wise elution, and capture from clarified culture media. Results demonstrate that the novel ligands result in milder elution pH, on average >0.5 pH units, when tested in a pH gradient. For step-wise elution at pH 4.0, the Z(H18S, N28A)4 ligand showed on average a greater than 30% increase in yield compared to Z4. Importantly, for the antibodies tested the mutations did not result in a decrease in dynamic binding capacity or other desirable attributes such as selectivity. A potential application of the novel ligands is shown with a pH sensitive molecule prone to aggregation under acidic conditions.
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Development and scale-up of a commercial fed batch refolding process for an anti-CD22 two chain immunotoxin.
Biotechnol. Prog.
PUBLISHED: 08-19-2014
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We describe the development and scale-up of a novel two chain immunotoxin refolding process. This work provides a case study comparing a clinical manufacturing process and the commercial process developed to replace it. While the clinical process produced high quality material, it suffered from low yield and high yield variability. A systematic approach to process development and understanding led to a number of improvements that were implemented in the commercial process. These include a shorter inclusion body recovery process, limiting the formation of an undesired deamidated species and the implementation of fed batch dilution refolding for increased refold titers. The use of a combination of urea, arginine and DTT for capture column cleaning restored the binding capacity of the capture step column and resulted in consistent capture step yields compared to the clinical process. Scalability is shown with data from 250 L and 950 L scale refolding processes. Compared to the clinical process it replaces, the commercial process demonstrated a greater than fivefold improvement in volumetric productivity at the 950 L refolding scale. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 2014.
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Oncologic Validity of Recipient Vessel Preservation in Microvascular Free-Flap Reconstruction.
ORL J. Otorhinolaryngol. Relat. Spec.
PUBLISHED: 08-14-2014
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Objectives: The use of free-flap reconstruction requires a more limited neck dissection to allow for microvascular anastomosis. This study seeks to determine the oncologic validity of cervical vessel preservation. Materials and Methods: The current study is a prospective review of cervical vessel biopsies from patients undergoing resection of squamous cell carcinoma (SCCA) tumors of the head and neck with free tissue reconstruction. Results: From June 2010 to March 2012, 227 recipient vessel biopsies were performed on 100 patients. Three of these patients had grossly abnormal vessels, with malignancy confirmed by frozen section analysis. One patient had a vessel positive for malignancy that was grossly normal but found to have SCCA on the final pathology. Conclusions: When the recipient vessel appears grossly suspicious, a frozen section biopsy and re-resection should be considered. Recipient vessel trimmings should routinely be sent for permanent pathology since in rare cases, they can be involved by tumor, affecting the margin status, prognosis, and indications for adjuvant therapy. © 2014 S. Karger AG, Basel.
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Development of a PET scanner for simultaneously imaging small animals with MRI and PET.
Sensors (Basel)
PUBLISHED: 08-12-2014
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Recently, positron emission tomography (PET) is playing an increasingly important role in the diagnosis and staging of cancer. Combined PET and X-ray computed tomography (PET-CT) scanners are now the modality of choice in cancer treatment planning. More recently, the combination of PET and magnetic resonance imaging (MRI) is being explored in many sites. Combining PET and MRI has presented many challenges since the photo-multiplier tubes (PMT) in PET do not function in high magnetic fields, and conventional PET detectors distort MRI images. Solid state light sensors like avalanche photo-diodes (APDs) and more recently silicon photo-multipliers (SiPMs) are much less sensitive to magnetic fields thus easing the compatibility issues. This paper presents the results of a group of Canadian scientists who are developing a PET detector ring which fits inside a high field small animal MRI scanner with the goal of providing simultaneous PET and MRI images of small rodents used in pre-clinical medical research. We discuss the evolution of both the crystal blocks (which detect annihilation photons from positron decay) and the SiPM array performance in the last four years which together combine to deliver significant system performance in terms of speed, energy and timing resolution.
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Direct endoscopic necrosectomy versus step-up approach for walled-off pancreatic necrosis: comparison of clinical outcome and health care utilization.
Pancreas
PUBLISHED: 08-02-2014
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Infected walled-off pancreatic necrosis (WOPN) is a complication of acute pancreatitis requiring intervention. Surgery is associated with considerable morbidity. Percutaneous catheter drainage (PCD), initial therapy in the step-up approach, minimizes complications. Direct endoscopic necrosectomy (DEN) has demonstrated safety and efficacy. We compared outcome and health care utilization of DEN versus step-up approach.
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Contractile reserve induced with dobutamine echocardiography predicts outcome in patients with left ventricular dysfunction and mitral regurgitation.
J. Heart Valve Dis.
PUBLISHED: 08-01-2014
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The appropriate management of patients with mitral regurgitation (MR) and left ventricular dysfunction (LVD) is controversial. The study aim was to determine whether the presence of contractile reserve (CR) assessed by dobutamine stress echocardiography (DSE) was associated with improved outcomes.
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Comparison of hemodynamic performance of the balloon-expandable SAPIEN 3 versus SAPIEN XT transcatheter valve.
Am. J. Cardiol.
PUBLISHED: 07-17-2014
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The SAPIEN 3 valve (S3V) is a new-generation transcatheter valve with enhanced anti-paravalvular leak properties, but no data comparing with earlier transcatheter valve systems are available. We aimed to compare the hemodynamic performance of the S3V and the SAPIEN XT valve (SXTV) in a case-matched study with echo core laboratory analysis. A total of 27 patients who underwent transcatheter aortic valve replacement (TAVR) with the S3V were matched for prosthesis size (26 mm), aortic annulus area, and mean diameter measured by computed tomography, left ventricular ejection fraction, body surface area, and body mass index with 50 patients treated with the SXTV. The prosthesis size was determined by oversizing of 1% to 15% of annulus area. Doppler echocardiographic images collected at baseline and 1-month follow-up were analyzed in a central echocardiography core laboratory. The need for postdilation was higher in the SXTV group (20% vs 4%, p=0.047), and mean residual gradient and effective orifice area were similar in both groups (p>0.05). The incidence of paravalvular aortic regurgitation was greater with the SXTV (?mild: 42%, moderate: 8%) than with the S3V (?mild: 7%, moderate: 0%; p=0.002 for ?mild vs SXTV). The implantation of an S3V was the only factor associated with trace or no paravalvular leak after TAVR (p=0.007). In conclusion, TAVR with the S3V was associated with a very low rate of paravalvular leaks and need for balloon postdilation, much lower than that observed with the earlier generation of balloon-expandable valve (SXTV). The confirmation of these results in a larger cohort of patients will represent a major step forward in using transcatheter valves for the treatment of aortic stenosis.
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Dramatically different kinetics and mechanism at solid/liquid and solid/gas interfaces for catalytic isopropanol oxidation over size-controlled platinum nanoparticles.
J. Am. Chem. Soc.
PUBLISHED: 07-15-2014
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We synthesize platinum nanoparticles with controlled average sizes of 2, 4, 6, and 8 nm and use them as model catalysts to study isopropanol oxidation to acetone in both the liquid and gas phases at 60 °C. The reaction at the solid/liquid interface is 2 orders of magnitude slower than that at the solid/gas interface, while catalytic activity increases with the size of platinum nanoparticles for both the liquid-phase and gas-phase reactions. The activation energy of the gas-phase reaction decreases with the platinum nanoparticle size and is in general much higher than that of the liquid-phase reaction which is largely insensitive to the size of catalyst nanoparticles. Water substantially promotes isopropanol oxidation in the liquid phase. However, it inhibits the reaction in the gas phase. The kinetic results suggest different mechanisms between the liquid-phase and gas-phase reactions, correlating well with different orientations of IPA species at the solid/liquid interface vs the solid/gas interface as probed by sum frequency generation vibrational spectroscopy under reaction conditions and simulated by computational calculations.
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Current status of endoscopic simulation in gastroenterology fellowship training programs.
Surg Endosc
PUBLISHED: 06-30-2014
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Recent guidelines have encouraged gastroenterology and surgical training programs to integrate simulation into their core endoscopic curricula. However, the role that simulation currently has within training programs is unknown. This study aims to assess the current status of simulation among gastroenterology fellowship programs.
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Hydroxylation of the surface of PbS nanocrystals passivated with oleic acid.
Science
PUBLISHED: 05-29-2014
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Controlling the structure of colloidal nanocrystals (NCs) is key to the generation of their complex functionality. This requires an understanding of the NC surface at the atomic level. The structure of colloidal PbS NCs passivated with oleic acid has been studied theoretically and experimentally. We show the existence of surface OH(-) groups, which play a key role in stabilizing the PbS(111) facets, consistent with x-ray photoelectron spectroscopy as well as other spectroscopic and chemical experiments. The role of water in the synthesis process is also revealed. Our model, along with existing observations of NC surface termination and passivation by ligands, helps to explain and predict the properties of NCs and their assemblies.
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In situ study of CO? and H?O partitioning between Na-montmorillonite and variably wet supercritical carbon dioxide.
Langmuir
PUBLISHED: 05-21-2014
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Shale formations play fundamental roles in large-scale geologic carbon sequestration (GCS) aimed primarily to mitigate climate change and in smaller-scale GCS targeted mainly for CO2-enhanced gas recovery operations. Reactive components of shales include expandable clays, such as montmorillonites and mixed-layer illite/smectite clays. In this study, in situ X-ray diffraction (XRD) and in situ infrared (IR) spectroscopy were used to investigate the swelling/shrinkage and H2O/CO2 sorption of Na(+)-exchanged montmorillonite, Na-SWy-2, as the clay is exposed to variably hydrated supercritical CO2 (scCO2) at 50 °C and 90 bar. Measured d001 values increased in stepwise fashion and sorbed H2O concentrations increased continuously with increasing percent H2O saturation in scCO2, closely following previously reported values measured in air at ambient pressure over a range of relative humidities. IR spectra show H2O and CO2 intercalation, and variations in peak shapes and positions suggest multiple sorbed types of H2O and CO2 with distinct chemical environments. Based on the absorbance of the asymmetric CO stretching band of the CO2 associated with the Na-SWy-2, the sorbed CO2 concentration increases dramatically at sorbed H2O concentrations from 0 to 4 mmol/g. Sorbed CO2 then sharply decreases as sorbed H2O increases from 4 to 10 mmol/g. With even higher sorbed H2O concentrations as saturation of H2O in scCO2 was approached, the concentration of sorbed CO2 decreased asymptotically. Two models, one involving space filling and the other a heterogeneous distribution of integral hydration states, are discussed as possible mechanisms for H2O and CO2 intercalations in montmorillonite. The swelling/shrinkage of montmorillonite could affect solid volume, porosity, and permeability of shales. Consequently, the results may aid predictions of shale caprock integrity in large-scale GCS as well as methane transmissivity in enhanced gas recovery operations.
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Muscle activation varies with contraction mode in human spinal cord injury.
Muscle Nerve
PUBLISHED: 05-09-2014
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Introduction: To better understand volitional force generation after chronic incomplete spinal cord injury (SCI), we examined muscle activation during single and repeated isometric, concentric, and eccentric knee extensor (KE) maximal voluntary contractions (MVCs). Methods: Torque and electromyographic (EMG) activity were recorded during single and repeated isometric and dynamic KE MVCs in 11 SCI subjects. Central activation ratios (CARs) were calculated for all contraction modes in SCI subjects and 11 healthy controls. Results: SCI subjects generated greater torque, KE EMG, and CARs during single eccentric vs. isometric and concentric MVCs (all P?25%) and concentric (>30%) MVCs. Conclusions: SCI subjects demonstrated greater muscle activation during eccentric MVCs vs. isometric and concentric MVCs. This pattern of activation contrasts with the decreased eccentric activation demonstrated by healthy controls. Such information may aid development of novel rehabilitation interventions. Muscle Nerve, 2014.
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Validation of an endoscopic part-task training box as a skill assessment tool.
Gastrointest. Endosc.
PUBLISHED: 05-08-2014
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There is no objective methodology to assess trainee progress in endoscopy. Our prior work has detailed the development of the endoscopic part-task training box.
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Automated high-pressure titration system with in situ infrared spectroscopic detection.
Rev Sci Instrum
PUBLISHED: 05-03-2014
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A fully automated titration system with infrared detection was developed for investigating interfacial chemistry at high pressures. The apparatus consists of a high-pressure fluid generation and delivery system coupled to a high-pressure cell with infrared optics. A manifold of electronically actuated valves is used to direct pressurized fluids into the cell. Precise reagent additions to the pressurized cell are made with calibrated tubing loops that are filled with reagent and placed in-line with the cell and a syringe pump. The cell's infrared optics facilitate both transmission and attenuated total reflection (ATR) measurements to monitor bulk-fluid composition and solid-surface phenomena such as adsorption, desorption, complexation, dissolution, and precipitation. Switching between the two measurement modes is accomplished with moveable mirrors that direct the light path of a Fourier transform infrared spectrometer into the cell along transmission or ATR light paths. The versatility of the high-pressure IR titration system was demonstrated with three case studies. First, we titrated water into supercritical CO2 (scCO2) to generate an infrared calibration curve and determine the solubility of water in CO2 at 50?°C and 90 bar. Next, we characterized the partitioning of water between a montmorillonite clay and scCO2 at 50?°C and 90 bar. Transmission-mode spectra were used to quantify changes in the clay's sorbed water concentration as a function of scCO2 hydration, and ATR measurements provided insights into competitive residency of water and CO2 on the clay surface and in the interlayer. Finally, we demonstrated how time-dependent studies can be conducted with the system by monitoring the carbonation reaction of forsterite (Mg2SiO4) in water-bearing scCO2 at 50?°C and 90 bar. Immediately after water dissolved in the scCO2, a thin film of adsorbed water formed on the mineral surface, and the film thickness increased with time as the forsterite began to dissolve. However, after approximately 2.5 h, the trend reversed, and a carbonate precipitate began to form on the forsterite surface, exposing dramatic chemical changes in the thin-water film. Collectively, these applications illustrate how the high-pressure IR titration system can provide molecular-level information about the interactions between variably wet scCO2 and minerals relevant to underground storage of CO2 (geologic carbon sequestration). The apparatus could also be utilized to study high-pressure interfacial chemistry in other areas such as catalysis, polymerization, food processing, and oil and gas recovery.
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Development and initial validation of an endoscopic part-task training box.
Endoscopy
PUBLISHED: 04-25-2014
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There is currently no objective and validated methodology available to assess the progress of endoscopy trainees or to determine when technical competence has been achieved. The aims of the current study were to develop an endoscopic part-task simulator and to assess scoring system validity.
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Survey of cosmetics for arsenic, cadmium, chromium, cobalt, lead, mercury, and nickel content.
J Cosmet Sci
PUBLISHED: 04-20-2014
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As part of efforts to assess amounts of inorganic element contamination in cosmetics, the U.S. Food and Drug Administration contracted a private laboratory to determine the total content of seven potentially toxic or allergenic elements in 150 cosmetic products of 12 types (eye shadows, blushes, lipsticks, three types of lotions, mascaras, foundations, body powders, compact powders, shaving creams, and face paints). Samples were analyzed for arsenic, cadmium, chromium, cobalt, lead, and nickel by inductively coupled plasma-mass spectrometry and for mercury by cold vapor atomic fluorescence spectrometry. The methods used to determine the elements were tested for validity by using standard reference materials with matrices similar to the cosmetic types. The cosmetic products were found to contain median values of 0.21 mg/kg arsenic, 3.1 mg/kg chromium, 0.91 mg/kg cobalt, 0.85 mg/kg lead, and 2.7 mg/kg nickel. The median values for cadmium and mercury were below the limits of detection of the methods. The contract requirements, testing procedures, and findings from the survey are described.
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Antiepileptic activity of preferential inhibitors of persistent sodium current.
Epilepsia
PUBLISHED: 04-12-2014
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Evidence from basic neurophysiology and molecular genetics has implicated persistent sodium current conducted by voltage-gated sodium (NaV ) channels as a contributor to the pathogenesis of epilepsy. Many antiepileptic drugs target NaV channels and modulate neuronal excitability, mainly by a use-dependent block of transient sodium current, although suppression of persistent current may also contribute to the efficacy of these drugs. We hypothesized that a drug or compound capable of preferential inhibition of persistent sodium current would have antiepileptic activity.
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Fever, immunity, and molecular adaptations.
Compr Physiol
PUBLISHED: 04-03-2014
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The heat shock response (HSR) is an ancient and highly conserved process that is essential for coping with environmental stresses, including extremes of temperature. Fever is a more recently evolved response, during which organisms temporarily subject themselves to thermal stress in the face of infections. We review the phylogenetically conserved mechanisms that regulate fever and discuss the effects that febrile-range temperatures have on multiple biological processes involved in host defense and cell death and survival, including the HSR and its implications for patients with severe sepsis, trauma, and other acute systemic inflammatory states. Heat shock factor-1, a heat-induced transcriptional enhancer is not only the central regulator of the HSR but also regulates expression of pivotal cytokines and early response genes. Febrile-range temperatures exert additional immunomodulatory effects by activating mitogen-activated protein kinase cascades and accelerating apoptosis in some cell types. This results in accelerated pathogen clearance, but increased collateral tissue injury, thus the net effect of exposure to febrile range temperature depends in part on the site and nature of the pathologic process and the specific treatment provided.
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Sociogenomics of self vs. non-self cooperation during development of Dictyostelium discoideum.
BMC Genomics
PUBLISHED: 03-26-2014
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Dictyostelium discoideum, a microbial model for social evolution, is known to distinguish self from non-self and show genotype-dependent behavior during chimeric development. Aside from a small number of cell-cell recognition genes, however, little is known about the genetic basis of self/non-self recognition in this species. Based on the key hypothesis that there should be differential expression of genes if D. discoideum cells were interacting with non-clone mates, we performed transcriptomic profiling study in this species during clonal vs. chimeric development. The transcriptomic profiles of D. discoideum cells in clones vs. different chimeras were compared at five different developmental stages using a customized microarray. Effects of chimerism on global transcriptional patterns associated with social interactions were observed.
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Do younger women fare worse? Sex differences in acute myocardial infarction hospitalization and early mortality rates over ten years.
J Womens Health (Larchmt)
PUBLISHED: 03-19-2014
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Recent research has identified younger women as an "at-risk" population with rising prevalence of cardiac risk factors and excess mortality risk following acute myocardial infarction (AMI). However, population-based data on trends in AMI hospitalization and early mortality post AMI among younger adults is scarce. We, therefore, aimed to provide a 10-year, descriptive analysis of these trends in a Canadian setting.
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A novel magnetic countertraction device for endoscopic submucosal dissection significantly reduces procedure time and minimizes technical difficulty.
Endoscopy
PUBLISHED: 02-26-2014
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In endoscopic submucosal dissection (ESD), effective countertraction may overcome the current drawbacks of longer procedure times and increased technical demands. The objective of this study was to compare the efficacy of ESD using a novel magnetic countertraction device with that of the traditional technique.
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The first pilot project of the consortium for top-down proteomics: a status report.
Proteomics
PUBLISHED: 02-25-2014
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Pilot Project #1--the identification and characterization of human histone H4 proteoforms by top-down MS--is the first project launched by the Consortium for Top-Down Proteomics (CTDP) to refine and validate top-down MS. Within the initial results from seven participating laboratories, all reported the probability-based identification of human histone H4 (UniProt accession P62805) with expectation values ranging from 10(-13) to 10(-105). Regarding characterization, a total of 74 proteoforms were reported, with 21 done so unambiguously; one new PTM, K79ac, was identified. Inter-laboratory comparison reveals aspects of the results that are consistent, such as the localization of individual PTMs and binary combinations, while other aspects are more variable, such as the accurate characterization of low-abundance proteoforms harboring >2 PTMs. An open-access tool and discussion of proteoform scoring are included, along with a description of general challenges that lie ahead including improved proteoform separations prior to mass spectrometric analysis, better instrumentation performance, and software development.
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A novel method for endoscopic perforation management by using abdominal exploration and full-thickness sutured closure.
Gastrointest. Endosc.
PUBLISHED: 02-18-2014
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Perforation of the GI tract during endoscopy can result in significant morbidity and mortality. Early recognition and immediate management of endoscopic perforation are essential to optimize outcome. Larger perforations, defects with complex geometry, and those complicated by leakage of luminal contents have traditionally required surgical management.
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Modifications to the endoscopic approach for anterior skull base lesions improve postoperative sinonasal symptoms.
J Neurol Surg B Skull Base
PUBLISHED: 02-06-2014
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Background/Objective?Our institution previously showed that patients experience significant postoperative sinonasal symptoms for the first few months after endoscopic transnasal transsphenoidal skull base surgery (eTNTS). Since our initial study we have modified our technique, discontinuing routine resection of the middle turbinate, maxillary antrostomies, and nasoseptal flaps. In this study, we analyze whether these technical modifications decrease postoperative sinonasal morbidity after eTNTS. Methods?A retrospective review was performed of 93 consecutive patients who underwent eTNTS at a tertiary academic medical center from August 2011 to August 2012. Main Outcome Measures? Sino-Nasal Outcome Test (SNOT)-20 and SNOT-22 scores preoperatively and after surgery. Results?Compared with our previous study, our new cohort experienced a significant improvement (p?
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Conscious sedation for upper endoscopy in the gastric bypass patient: prevalence of cardiopulmonary adverse events and predictors of sedation requirement.
Dig. Dis. Sci.
PUBLISHED: 02-04-2014
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Safety of conscious sedation for performing esophagoduodenoscopy (EGD) in obese and Roux-en-Y gastric bypass (RYGB) patients remains controversial. Additionally, it has been suggested that patients with higher body mass index (BMI) require higher sedation doses, imparting greater risk.
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Comparison of a superficial suturing device with a full-thickness suturing device for transoral outlet reduction (with videos).
Gastrointest. Endosc.
PUBLISHED: 02-03-2014
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Larger gastrojejunal (GJ) anastomosis aperture is one independent predictor for weight regain after Roux-en-Y gastric bypass. Transoral outlet reduction (TORe) has proven safe and effective for treatment of weight regain by using a superficial-thickness (ST) suturing device. Full-thickness (FT) suturing devices are now available, potentially providing more effective results.
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Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video).
Gastrointest. Endosc.
PUBLISHED: 01-29-2014
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The lack of countertraction in endoscopic submucosal dissection (ESD) results in increased technical demand and procedure time. Although the suture-pulley method for countertraction has been reported, its effectiveness compared with the traditional ESD technique remains unclear.
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Invasive fungal sinusitis in a healthy athlete due to long-term anabolic steroid use.
Laryngoscope
PUBLISHED: 01-21-2014
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Invasive fungal rhinosinusitis is a potentially fatal infection that affects immunocompromised patients. Prognosis is generally poor despite aggressive medical and surgical treatments. We present the first reported case of invasive fungal sinusitis in a healthy 18-year-old male athlete who was taking anabolic androgenic steroids (AAS). The effects of excessive AAS use on the immune system are not fully understood, but there may be consequences at supraphysiological concentrations. This case demonstrates potential immunomodulatory effects of anabolic steroids and highlights a previously unknown cause of invasive fungal sinusitis.
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Prostate stereotactic ablative radiation therapy using volumetric modulated arc therapy to dominant intraprostatic lesions.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 01-20-2014
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To investigate boosting dominant intraprostatic lesions (DILs) in the context of stereotactic ablative radiation therapy (SABR) and to examine the impact on tumor control probability (TCP) and normal tissue complication probability (NTCP).
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Prevalence and impact of preoperative moderate/severe tricuspid regurgitation on patients undergoing transcatheter aortic valve replacement.
Catheter Cardiovasc Interv
PUBLISHED: 01-16-2014
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Significant tricuspid regurgitation (TR) is a marker for late-stage myocardial and valvular heart disease. Whether preoperative TR affects clinical outcomes of patients undergoing transcatheter aortic valve replacement (TAVR) has never been investigated. This study sought to identify the impact of moderate and severe TR on outcomes after TAVR.
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Newly diagnosed T1 diabetes presenting with hypoglycemia due to simultaneous co-existence of Addison disease.
Pediatr Diabetes
PUBLISHED: 01-13-2014
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Type 1 diabetes mellitus (TIDM) classically presents with symptomatic hyperglycemia and many patients develop diabetic ketoacidosis prior to their diagnosis. However, non-classical presentation or co-presentation with associated diseases may delay diagnosis or lead to challenges in acute, clinical management. An 18-yr-old girl presented to hospital with severe, symptomatic hypoglycemia. Clinical history and serum electrolyte concentrations suggested a diagnosis of adrenal insufficiency. She remained hypoglycemic until glucocorticoid replacement was commenced, at which point she developed persistent hyperglycemia requiring insulin therapy. Subsequent follow up confirmed the diagnosis of Addison's disease (AD), the treatment of which unmasked co-existing type 1 diabetes. Autoimmune diseases often cluster together in affected patients and first-degree relatives. Approximately 1 in 200 patients with T1DM develop AD. However, months or more commonly years usually elapse between the presentation of different autoimmune conditions. The co-diagnosis T1DM and AD in the acute setting is rare. Moreover, the first presentation of T1DM with severe hypoglycemia is even more exceptional. This case highlights the need for vigilance during the acute, emergency management of patients with autoimmune conditions and, in particular, to consider the possibility of concurrent antibody-mediated diseases which may need to be addressed during resuscitation.
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Strain- and age-dependent hippocampal neuron sodium currents correlate with epilepsy severity in Dravet syndrome mice.
Neurobiol. Dis.
PUBLISHED: 01-03-2014
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Heterozygous loss-of-function SCN1A mutations cause Dravet syndrome, an epileptic encephalopathy of infancy that exhibits variable clinical severity. We utilized a heterozygous Scn1a knockout (Scn1a(+/-)) mouse model of Dravet syndrome to investigate the basis for phenotype variability. These animals exhibit strain-dependent seizure severity and survival. Scn1a(+/-) mice on strain 129S6/SvEvTac (129.Scn1a(+/-)) have no overt phenotype and normal survival compared with Scn1a(+/-) mice bred to C57BL/6J (F1.Scn1a(+/-)) that have severe epilepsy and premature lethality. We tested the hypothesis that strain differences in sodium current (INa) density in hippocampal neurons contribute to these divergent phenotypes. Whole-cell voltage-clamp recording was performed on acutely-dissociated hippocampal neurons from postnatal days 21-24 (P21-24) 129.Scn1a(+/-) or F1.Scn1a(+/-) mice and wild-type littermates. INa density was lower in GABAergic interneurons from F1.Scn1a(+/-) mice compared to wild-type littermates, while on the 129 strain there was no difference in GABAergic interneuron INa density between 129.Scn1a(+/-) mice and wild-type littermate controls. By contrast, INa density was elevated in pyramidal neurons from both 129.Scn1a(+/-) and F1.Scn1a(+/-) mice, and was correlated with more frequent spontaneous action potential firing in these neurons, as well as more sustained firing in F1.Scn1a(+/-) neurons. We also observed age-dependent differences in pyramidal neuron INa density between wild-type and Scn1a(+/-) animals. We conclude that preserved INa density in GABAergic interneurons contributes to the milder phenotype of 129.Scn1a(+/-) mice. Furthermore, elevated INa density in excitatory pyramidal neurons at P21-24 correlates with age-dependent onset of lethality in F1.Scn1a(+/-) mice. Our findings illustrate differences in hippocampal neurons that may underlie strain- and age-dependent phenotype severity in a Dravet syndrome mouse model, and emphasize a contribution of pyramidal neuron excitability.
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Developmental lineage priming in Dictyostelium by heterogeneous Ras activation.
Elife
PUBLISHED: 11-28-2013
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In cell culture, genetically identical cells often exhibit heterogeneous behavior, with only lineage primed cells responding to differentiation inducing signals. It has recently been proposed that such heterogeneity exists during normal embryonic development to allow position independent patterning based on salt and pepper differentiation and sorting out. However, the molecular basis of lineage priming and how it leads to reproducible cell type proportioning are poorly understood. To address this, we employed a novel forward genetic approach in the model organism Dictyostelium discoideum. These studies reveal that the Ras-GTPase regulator gefE is required for normal lineage priming and salt and pepper differentiation. This is because Ras-GTPase activity sets the intrinsic response threshold to lineage specific differentiation signals. Importantly, we show that although gefE expression is uniform, transcription of its target, rasD, is both heterogeneous and dynamic, thus providing a novel mechanism for heterogeneity generation and position-independent differentiation. DOI: http://dx.doi.org/10.7554/eLife.01067.001.
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Development and evaluation of a LOR-based image reconstruction with 3D system response modeling for a PET insert with dual-layer offset crystal design.
Phys Med Biol
PUBLISHED: 11-11-2013
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In this study we present a method of 3D system response calculation for analytical computer simulation and statistical image reconstruction for a magnetic resonance imaging (MRI) compatible positron emission tomography (PET) insert system that uses a dual-layer offset (DLO) crystal design. The general analytical system response functions (SRFs) for detector geometric and inter-crystal penetration of coincident crystal pairs are derived first. We implemented a 3D ray-tracing algorithm with 4? sampling for calculating the SRFs of coincident pairs of individual DLO crystals. The determination of which detector blocks are intersected by a gamma ray is made by calculating the intersection of the ray with virtual cylinders with radii just inside the inner surface and just outside the outer-edge of each crystal layer of the detector ring. For efficient ray-tracing computation, the detector block and ray to be traced are then rotated so that the crystals are aligned along the X-axis, facilitating calculation of ray/crystal boundary intersection points. This algorithm can be applied to any system geometry using either single-layer (SL) or multi-layer array design with or without offset crystals. For effective data organization, a direct lines of response (LOR)-based indexed histogram-mode method is also presented in this work. SRF calculation is performed on-the-fly in both forward and back projection procedures during each iteration of image reconstruction, with acceleration through use of eight-fold geometric symmetry and multi-threaded parallel computation. To validate the proposed methods, we performed a series of analytical and Monte Carlo computer simulations for different system geometry and detector designs. The full-width-at-half-maximum of the numerical SRFs in both radial and tangential directions are calculated and compared for various system designs. By inspecting the sinograms obtained for different detector geometries, it can be seen that the DLO crystal design can provide better sampling density than SL or dual-layer no-offset system designs with the same total crystal length. The results of the image reconstruction with SRFs modeling for phantom studies exhibit promising image recovery capability for crystal widths of 1.27-1.43 mm and top/bottom layer lengths of 4/6 mm. In conclusion, we have developed efficient algorithms for system response modeling of our proposed PET insert with DLO crystal arrays. This provides an effective method for both 3D computer simulation and quantitative image reconstruction, and will aid in the optimization of our PET insert system with various crystal designs.
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Developing a class solution for Prostate Stereotactic Ablative Body Radiotherapy (SABR) using Volumetric Modulated Arc Therapy (VMAT).
Radiother Oncol
PUBLISHED: 10-28-2013
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To develop a class solution for prostate Stereotactic Ablative Radiotherapy (SABR) using Volumetric Modulated Arc Therapy (VMAT).
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Impact of Preoperative Moderate/Severe Mitral Regurgitation on 2-Year Outcome After Transcatheter and Surgical Aortic Valve Replacement: Insight From the Placement of Aortic Transcatheter Valve (PARTNER) Trial Cohort A.
Circulation
PUBLISHED: 10-23-2013
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The effect of preoperative mitral regurgitation (MR) on clinical outcomes of patients undergoing transcatheter aortic valve replacement (TAVR) is controversial. This study sought to examine the impact of moderate and severe MR on outcomes after TAVR and surgical aortic valve replacement (SAVR).
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Low-dose hydrocortisone replacement therapy is associated with improved bone remodelling balance in hypopituitary male patients.
Eur. J. Endocrinol.
PUBLISHED: 10-15-2013
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Glucocorticoid (GC) therapy is associated with adverse effects on bone metabolism, yet the effects of different GC physiological replacement regimens in hypopituitarism are not well characterised. We aimed to assess the effect of three hydrocortisone (HC) replacement dose regimens on bone turnover.
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Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations.
Am. J. Med.
PUBLISHED: 10-01-2013
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Hyponatremia is a serious, but often overlooked, electrolyte imbalance that has been independently associated with a wide range of deleterious changes involving many different body systems. Untreated acute hyponatremia can cause substantial morbidity and mortality as a result of osmotically induced cerebral edema, and excessively rapid correction of chronic hyponatremia can cause severe neurologic impairment and death as a result of osmotic demyelination. The diverse etiologies and comorbidities associated with hyponatremia pose substantial challenges in managing this disorder. In 2007, a panel of experts in hyponatremia convened to develop the Hyponatremia Treatment Guidelines 2007: Expert Panel Recommendations that defined strategies for clinicians caring for patients with hyponatremia. In the 6 years since the publication of that document, the field has seen several notable developments, including new evidence on morbidities and complications associated with hyponatremia, the importance of treating mild to moderate hyponatremia, and the efficacy and safety of vasopressin receptor antagonist therapy for hyponatremic patients. Therefore, additional guidance was deemed necessary and a panel of hyponatremia experts (which included all of the original panel members) was convened to update the previous recommendations for optimal current management of this disorder. The updated expert panel recommendations in this document represent recommended approaches for multiple etiologies of hyponatremia that are based on both consensus opinions of experts in hyponatremia and the most recent published data in this field.
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Selective targeting of gain-of-function KCNQ1 mutations predisposing to atrial fibrillation.
Circ Arrhythm Electrophysiol
PUBLISHED: 09-04-2013
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Atrial fibrillation is the most common sustained cardiac arrhythmia in adults. We hypothesized that gain-of-function KCNQ1 mutations previously associated with familial atrial fibrillation have distinct pharmacological properties that may enable targeted inhibition.
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Calcium-dependent regulation of Rab activation and vesicle fusion by an intracellular P2X ion channel.
Nat. Cell Biol.
PUBLISHED: 07-18-2013
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Rab GTPases play key roles in the delivery, docking and fusion of intracellular vesicles. However, the mechanism by which spatial and temporal regulation of Rab GTPase activity is controlled is poorly understood. Here we describe a mechanism by which localized calcium release through a vesicular ion channel controls Rab GTPase activity. We show that activation of P2XA, an intracellular ion channel localized to the Dictyostelium discoideum contractile vacuole system, results in calcium efflux required for downregulation of Rab11a activity and efficient vacuole fusion. Vacuole fusion and Rab11a downregulation require the activity of CnrF, an EF-hand-containing Rab GAP found in a complex with Rab11a and P2XA. CnrF Rab GAP activity for Rab11a is enhanced by the presence of calcium and the EF-hand domain. These findings suggest that P2XA activation results in vacuolar calcium release, which triggers activation of CnrF Rab GAP activity and subsequent downregulation of Rab11a to allow vacuole fusion.
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The next generation of endoscopic simulation.
Am. J. Gastroenterol.
PUBLISHED: 07-04-2013
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Over the past decade, the capabilities and use of endoscopic simulators have steadily expanded. Nevertheless, simulator use has yet to become fully integrated into standard endoscopic training programs. There are two obstacles. First, we lack adequate knowledge about how competency should be defined and how people become proficient in various specific techniques. Second, there has not been an affordable and convenient model to effectively assist in training and assessment. This paper explores the barriers to incorporation of simulators in training programs, and discusses currently available mechanical, computer, and ex vivo tissue models for assessment.
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Tranexamic acid and trauma: current status and knowledge gaps with recommended research priorities.
Shock
PUBLISHED: 06-08-2013
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A recent large civilian randomized controlled trial on the use of tranexamic acid (TXA) for trauma reported important survival benefits. Subsequently, successful use of TXA for combat casualties in Afghanistan was also reported. As a result of these promising studies, there has been growing interest in the use of TXA for trauma. Potential adverse effects of TXA have also been reported. A US Department of Defense committee conducted a review and assessment of knowledge gaps and research requirements regarding the use of TXA for the treatment of casualties that have experienced traumatic hemorrhage. We present identified knowledge gaps and associated research priorities. We believe that important knowledge gaps exist and that a targeted, prioritized research effort will contribute to the refinement of practice guidelines over time.
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Functional properties of five Dictyostelium discoideum P2X receptors.
J. Biol. Chem.
PUBLISHED: 06-05-2013
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The Dictyostelium discoideum genome encodes five proteins that share weak sequence similarity with vertebrate P2X receptors. Unlike vertebrate P2X receptors, these proteins are not expressed on the surface of cells, but populate the tubules and bladders of the contractile vacuole. In this study, we expressed humanized cDNAs of P2XA, P2XB, P2XC, P2XD, and P2XE in human embryonic kidney cells and altered the ionic and proton environment in an attempt to reflect the situation in amoeba. Recording of whole-cell membrane currents showed that four receptors operated as ATP-gated channels (P2XA, P2XB, P2XD, and P2XE). At P2XA receptors, ATP was the only effective agonist of 17 structurally related putative ligands that were tested. Extracellular sodium, compared with potassium, strongly inhibited ATP responses in P2XB, P2XD, and P2XE receptors. Increasing the proton concentration (pH 6.2) accelerated desensitization at P2XA receptors and decreased currents at P2XD receptors, but increased the currents at P2XB and P2XE receptors. Dictyostelium lacking P2XA receptors showed impaired regulatory volume decrease in hypotonic solution. This phenotype was readily rescued by overexpression of P2XA and P2XD receptors, partially rescued by P2XB and P2XE receptors, and not rescued by P2XC receptors. The failure of the nonfunctional receptor P2XC to restore the regulatory volume decrease highlights the importance of ATP activation of P2X receptors for a normal response to hypo-osmotic shock, and the weak rescue by P2XB and P2XE receptors indicates that there is limited functional redundancy among Dictyostelium P2X receptors.
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Short-term maximal-intensity resistance training increases volitional function and strength in chronic incomplete spinal cord injury: a pilot study.
J Neurol Phys Ther
PUBLISHED: 05-16-2013
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Recent research shows that individuals with an incomplete spinal cord injury (SCI) have a reserve of force-generating capability that is observable during repeated intermittent maximal volitional effort contractions. Previous studies suggest that increased neural drive contributes to the enhanced short-term force-generating capabilities. Whether this reserve can be harnessed with repeated training is unclear. The purpose of this pilot study was to investigate the effects of 4 weeks of maximal-intensity resistance training, compared with conventional progressive resistance training, on lower extremity function and strength in chronic incomplete SCI.
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Mini-nasoseptal flap for recalcitrant sphenoid sinusitis.
Am J Rhinol Allergy
PUBLISHED: 04-09-2013
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Recalcitrant sphenoid sinusitis occurs in 27% of patients undergoing revision functional endoscopic sinus surgery. One of the main causes of disease recurrence in the sphenoid is cicatricial scarring of the ostium. Highly inflammatory lesions such as fungal balls or chronic mucoceles can predispose patients to restenosis. We present a novel use of a modified nasoseptal flap to cover exposed bone after sphenoid wide sinusotomy to prevent restenosis and expedite healing.
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Divergent modulation of clinical measures of volitional and reflexive motor behaviors following serotonergic medications in human incomplete spinal cord injury.
J. Neurotrauma
PUBLISHED: 04-03-2013
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Incomplete spinal cord injury (SCI) can result in profound impairments in volitional strength and reflex excitability, which contribute to loss of function. Human and animal models suggest that disruption of endogenous monoaminergic input, particularly serotonin (5-HT), from supraspinal centers contributes to this impaired motor function following SCI. In the present study, we investigated the effects of 5-HT medications on motor function in individuals with chronic (>1 year) SCI. Clinical measures of strength, spasticity/spasms, and walking ability were assessed in 12 individuals with chronic incomplete SCI following acute administration of either 8?mg cyproheptadine, a 5-HT antagonist, or 10?mg escitalopram, a selective 5-HT reuptake inhibitor (SSRI), in a double-blinded, randomized, crossover fashion. Results indicated that 5-HT medications modulated both volitional and reflexive behaviors with little change in walking performance; 5-HT antagonist medications depressed clinical measures of strength and spasticity/spasms, whereas SSRIs augmented both strength and spasticity/spasms. These changes are consistent with the dysregulation of 5-HT sensitive spinal neurons following SCI. This understanding may augment clinicians awareness of the motor consequences of 5-HT medications.
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Endoscopic suturing for transoral outlet reduction increases weight loss after Roux-en-Y gastric bypass surgery.
Gastroenterology
PUBLISHED: 03-29-2013
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Weight regain or insufficient loss after Roux-en-Y gastric bypass (RYGB) is common. This is partially attributable to dilatation of the gastrojejunostomy (GJ), which diminishes the restrictive capacity of RYGB. Endoluminal interventions for GJ reduction are being explored as alternatives to revision surgery. We performed a randomized, blinded, sham-controlled trial to evaluate weight loss after sutured transoral outlet reduction (TORe).
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Systematic review and meta-analysis of total intravenous anesthesia and endoscopic sinus surgery.
Int Forum Allergy Rhinol
PUBLISHED: 03-11-2013
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Total intravenous anesthesia (TIVA) has been shown in some studies to impact visual field, blood loss, and cardiovascular parameters during endoscopic sinus surgery when compared to inhalational anesthesia (IA). These variables are critical in endoscopic sinus surgery. A systematic review and meta-analysis was undertaken to discern the impact of TIVA vs IA in endoscopic sinus surgery.
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Solitary fibrous tumor of the hypopharynx: case report and literature review.
Am J Otolaryngol
PUBLISHED: 03-04-2013
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Solitary fibrous tumors are rare mesenchymal neoplasms that are increasingly being described in the head and neck. Clinical presentations may include compression by these tumors on vital surrounding structures. While malignant transformation is rare, treatment entails wide local excision. We present the case of a 74 year-old female with an increasingly enlarging symptomatic hypopharyngeal solitary fibrous tumor that was found on carotid duplex ultrasound. Transoral surgical excision resulted in relief of symptoms. Treatment options are discussed and a literature review of this uncommon disorder presented.
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The SH2 domain interaction landscape.
Cell Rep
PUBLISHED: 02-28-2013
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Members of the SH2 domain family modulate signal transduction by binding to short peptides containing phosphorylated tyrosines. Each domain displays a distinct preference for the sequence context of the phosphorylated residue. We have developed a high-density peptide chip technology that allows for probing of the affinity of most SH2 domains for a large fraction of the entire complement of tyrosine phosphopeptides in the human proteome. Using this technique, we have experimentally identified thousands of putative SH2-peptide interactions for more than 70 different SH2 domains. By integrating this rich data set with orthogonal context-specific information, we have assembled an SH2-mediated probabilistic interaction network, which we make available as a community resource in the PepspotDB database. A predicted dynamic interaction between the SH2 domains of the tyrosine phosphatase SHP2 and the phosphorylated tyrosine in the extracellular signal-regulated kinase activation loop was validated by experiments in living cells.
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Young and intense: FoxP2 immunoreactivity in Area X varies with age, song stereotypy, and singing in male zebra finches.
Front Neural Circuits
PUBLISHED: 02-02-2013
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FOXP2 is a transcription factor functionally relevant for learned vocalizations in humans and songbirds. In songbirds, FoxP2 mRNA expression in the medium spiny neurons of the basal ganglia song nucleus Area X is developmentally regulated and varies with singing conditions in different social contexts. How individual neurons in Area X change FoxP2 expression across development and in social contexts is not known, however. Here we address this critical gap in our understanding of FoxP2 as a link between neuronal networks and behavior. We used a statistically unbiased analysis of FoxP2-immunoreactivity (FoxP2-IR) on a neuron-by-neuron basis and found a bimodal distribution of FoxP2-IR neurons in Area X: weakly-stained and intensely-stained. The density of intensely-stained FoxP2-IR neurons was 10 times higher in juveniles than in adults, exponentially decreased with age, and was negatively correlated with adult song stability. Three-week old neurons labeled with BrdU were more than five times as likely to be intensely-stained than weakly-stained. The density of FoxP2-IR putative migratory neurons with fusiform-shaped nuclei substantially decreased as birds aged. The density of intensely-stained FoxP2-IR neurons was not affected by singing whereas the density of weakly-stained FoxP2-IR neurons was. Together, these data indicate that young Area X medium spiny neurons express FoxP2 at high levels and decrease expression as they become integrated into existing neural circuits. Once integrated, levels of FoxP2 expression correlate with singing behavior. Together, these findings raise the possibility that FoxP2 levels may orchestrate song learning and song stereotypy in adults by a common mechanism.
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Determinants of percutaneous coronary intervention vs coronary artery bypass grafting: an interprovincial comparison.
Can J Cardiol
PUBLISHED: 01-28-2013
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Marked variation exists concerning the utilization of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The objective of this study was to examine differences in predictors of mode of revascularization across 3 provincial jurisdictions.
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5-year experience with transcatheter transapical mitral valve-in-valve implantation for bioprosthetic valve dysfunction.
J. Am. Coll. Cardiol.
PUBLISHED: 01-08-2013
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The study sought to describe the authors experience with mitral transapical transcatheter valve-in-valve implantation (TVIV).
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The songbird syrinx morphome: a three-dimensional, high-resolution, interactive morphological map of the zebra finch vocal organ.
BMC Biol.
PUBLISHED: 01-08-2013
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Like human infants, songbirds learn their species-specific vocalizations through imitation learning. The birdsong system has emerged as a widely used experimental animal model for understanding the underlying neural mechanisms responsible for vocal production learning. However, how neural impulses are translated into the precise motor behavior of the complex vocal organ (syrinx) to create song is poorly understood. First and foremost, we lack a detailed understanding of syringeal morphology.
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Sinonasal rhabdomyosarcoma: prognostic factors and treatment outcomes.
Int Forum Allergy Rhinol
PUBLISHED: 01-01-2013
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Despite the improvement in survival of pediatric patients with rhabdomyosarcoma, the outcome of patients with sinonasal rhabdomyosarcoma is poor and has not significantly changed. Since few institutions have extensive experience with sinonasal rhabdomyosarcoma in children and adults, our objective was to determine prognostic factors and treatment outcomes for this rare malignancy.
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High-resolution Fourier-transform infrared spectroscopy of the ?6 and Coriolis perturbation allowed ?10 modes of ketenimine.
J Chem Phys
PUBLISHED: 12-16-2011
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High-resolution FTIR spectra of the short lived species ketenimine have been recorded in the region 700-1300 cm(-1) and over 1500 transitions of the ?(10) and ?(6) modes have been assigned. Effective rotational and centrifugal distortion parameters for the v(10) = 1 and v(6) = 1 (excluding K(a) = 5) states were determined by co-fitting transitions, and treating strong a- and c-axis Coriolis interactions between them. Other perturbations attributed to interactions with the v(8) = 2 and v(12) = 1 + v(8) = 1 dark-states were also observed and treated. The ?(10) transitions are predicted to be inherently very weak, but are enhanced by an intensity stealing effect with the highly IR active ?(6) mode. A mechanism for this intensity stealing in ketenimine is also detailed.
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Obesity and bariatrics for the endoscopist: new techniques.
Therap Adv Gastroenterol
PUBLISHED: 11-02-2011
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Obesity and its associated conditions, including type 2 diabetes and cardiovascular disease, have reached epidemic proportions. Gastrointestinal weight loss surgery (GIWLS) shows the most promise in achieving significant and sustained weight loss and diabetes resolution. However, a large mismatch exists between the magnitude of the obesity epidemic and the number of surgical procedures performed to produce a significant shift in the distribution of obesity on a population level. This mismatch is fueled by high surgical costs, morbidity and mortality associated with surgical interventions, and the fact that the greatest public health burden of obesity comes from those around the center of the population body mass index distribution with mild to moderate obesity, rather than those at the distribution tail with severe obesity that GIWLS targets. New endoscopic methods, capitalizing on advances in our understanding of the physiological mechanisms by which GIWLS works, are developing to provide viable alternatives in the treatment of bariatric surgical complications, and for the primary treatment of obesity. These methods may have the added advantage of reduced invasiveness, reversibility, cost-effectiveness, and applicability to a larger segment of the population with moderate obesity.
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Variation of the Fourier transform mass spectra phase function with experimental parameters.
Anal. Chem.
PUBLISHED: 10-25-2011
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It has been known for almost 40 years that phase correction of Fourier transform ion cyclotron resonance (FTICR) data can generate an absorption-mode spectrum with much improved peak shape compared to the conventional magnitude-mode. However, research on phasing has been slow due to the complexity of the phase-wrapping problem. Recently, the method for phasing a broadband FTICR spectrum has been solved in the MS community which will surely resurrect this old topic. This paper provides a discussion on the data processing procedure of phase correction and features of the phase function based on both a mathematical treatment and experimental data. Finally, it is shown that the same phase function can be optimized by adding correction factors and can be applied from one experiment to another with different instrument parameters, regardless of the sample measured. Thus, in the vast majority of cases, the phase function needs to be calculated just once, whenever the instrument is calibrated.
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Identifying coronary artery disease in men with type 2 diabetes: osteoprotegerin, pulse wave velocity, and other biomarkers of cardiovascular risk.
J. Hypertens.
PUBLISHED: 10-06-2011
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In patients with type 2 diabetes, high serum levels of osteoprotegerin (OPG) have been associated with a greater risk of cardiovascular events. However, it remains unclear how well OPG performs when compared with traditional biomarkers of cardiovascular risk such as high-sensitivity C-reactive protein (hsCRP). Furthermore, OPG levels are also high in the presence of diabetes-related microvascular disease, and it is unclear whether OPG can distinguish microvascular disease from large-vessel atherosclerosis. The first aim of this study was to compare OPG levels against other biomarkers of cardiovascular risk in the identification of patients with documented multivessel coronary artery disease (CAD). The second aim was to compare OPG levels in patients with microvascular complications (microalbuminuria) against those with established CAD.
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A Pt-cluster-based heterogeneous catalyst for homogeneous catalytic reactions: X-ray absorption spectroscopy and reaction kinetic studies of their activity and stability against leaching.
J. Am. Chem. Soc.
PUBLISHED: 08-04-2011
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The design and development of metal-cluster-based heterogeneous catalysts with high activity, selectivity, and stability under solution-phase reaction conditions will enable their applications as recyclable catalysts in large-scale fine chemicals production. To achieve these required catalytic properties, a heterogeneous catalyst must contain specific catalytically active species in high concentration, and the active species must be stabilized on a solid catalyst support under solution-phase reaction conditions. These requirements pose a great challenge for catalysis research to design metal-cluster-based catalysts for solution-phase catalytic processes. Here, we focus on a silica-supported, polymer-encapsulated Pt catalyst for an electrophilic hydroalkoxylation reaction in toluene, which exhibits superior selectivity and stability against leaching under mild reaction conditions. We unveil the key factors leading to the observed superior catalytic performance by combining X-ray absorption spectroscopy (XAS) and reaction kinetic studies. On the basis of the mechanistic understandings obtained in this work, we also provide useful guidelines for designing metal-cluster-based catalyst for a broader range of reactions in the solution phase.
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The results of temporal bone surgery for advanced or recurrent tumors of the parotid gland.
Laryngoscope
PUBLISHED: 07-28-2011
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To describe the results of temporal bone surgery in managing advanced or recurrent tumors of the parotid gland.
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Endoscopic solutions for weight loss.
Curr. Opin. Gastroenterol.
PUBLISHED: 07-12-2011
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Gastroenterologists will likely play a critical role in the treatment of obesity and its comorbidities, as novel endoluminal approaches demonstrate their safety and efficacy over the coming years. Understanding the relative advantages and shortcomings of the endoscopic tools and procedures currently under investigation will provide the gastroenterologist with valuable insight into the future of endoscopic procedures for weight loss.
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High-resolution Fourier-transform infrared spectroscopy of the Coriolis coupled ground state and ?7 mode of ketenimine.
J Chem Phys
PUBLISHED: 06-28-2011
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High resolution FTIR spectra of the short lived species ketenimine have been recorded in the regions 390-1300 cm(-1) and 20-110 cm(-1) using synchrotron radiation. Two thousand six hundred sixty transitions of the ?(7) band centered at 693 cm(-1) and 126 far-IR rotational transitions have been assigned. Rotational and centrifugal distortion parameters for the ?(7) mode were determined and local Fermi and b-axis Coriolis interactions with 2?(12) are treated. A further refinement of the ground state, ?(12) and ?(8) parameters was also achieved, including the treatment of previously unrecognized ac-axis and ab-axis second order perturbations to the ground state.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.