keyword
MENU ▼
Read by QxMD icon Read
search

Contrast kinetics

keyword
https://www.readbyqxmd.com/read/28345900/fluorescence-and-radio-labeling-of-lys-4-nle-17-30-hpp-yields-molecular-tools-for-the-npy-y4-receptor
#1
Stefanie Dukorn, Timo Littmann, Max Keller, Kilian Konrad Kuhn, Chiara Cabrele, Paul Baumeister, Günther Bernhardt, Armin Buschauer
The neuropeptide Y (NPY) Y4 receptor (Y4R) is involved in energy homeostasis and considered as a potential drug target for the treatment of obesity. Only a few molecular tools, i. e., radiolabeled and fluorescent ligands, for the investigation of the Y4R were reported. Previously, [Lys(4)]hPP proved to be an appropriate full-length PP analog to prepare a fluorescent ligand by derivatization at the ε-amino group. To preclude oxidation upon long-term storage, we replaced the two methionine residues in [Lys(4)]hPP by norleucine and prepared the corresponding [(3)H]propionylated ([(3)H]12) and cyanine labeled (13) peptides, which were characterized and compared with a set of reference compounds in binding (Y1, Y2, Y4 and Y5 receptors) and functional (luciferase gene reporter, β-arrestin-1, -2) Y4R assays...
March 27, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28345895/asymmetric-anchoring-is-required-for-efficient-%C3%AE-loop-opening-and-closing-in-cytosolic-phosphoenolpyruvate-carboxykinase
#2
Danica Cui, Aron Broom, Matthew J Mcleod, Elizabeth M Meiering, Todd Holyoak
Mobile Ω-loops play essential roles in the function of many enzymes. Here we investigated the importance of a residue lying outside of the mobile Ω-loop element in the catalytic function of an H477R variant of cPEPCK using crystallographic, kinetic, and computational analysis. The crystallographic data suggest that efficient transitioning of the Ω-loop to the closed conformation requires stabilization of the N-terminus of the loop through contacts between R461 and E588. In contrast, the C-terminal end of the Ω-loop undergoes changing interactions with the enzyme body through contacts between H477 at the C-terminus of the loop and E591 located on the enzyme body...
March 27, 2017: Biochemistry
https://www.readbyqxmd.com/read/28345888/influence-of-ring-strain-and-bond-polarization-on-the-ring-expansion-of-phosphorus-homocycles
#3
Saurabh S Chitnis, Rebecca A Musgrave, Hazel A Sparkes, Natalie E Pridmore, Vincent T Annibale, Ian Manners
Heterolytic cleavage of homoatomic bonds is a challenge, as it requires separation of opposite charges. Even highly strained homoatomic rings (e.g., cyclopropane and cyclobutane) are kinetically stable and do not react with nucleophiles or electrophiles. In contrast, cycloalkanes bearing electron-donating/withdrawing substituents on adjacent carbons have polarized C-C bonds and undergo numerous heterolytic ring-opening and expansion reactions. Here we show that upon electrophile activation phosphorus homocycles exhibit analogous reactivity, which is modulated by the amount of ring strain and extent of bond polarization...
March 27, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28344126/regulation-of-the-nitric-oxide-oxidase-activity-of-myeloperoxidase-by-pharmacological-agents
#4
Sophie L Maiocchi, Jonathan C Morris, Martin D Rees, Shane R Thomas
The leukocyte-derived heme enzyme myeloperoxidase (MPO) is released extracellularly during inflammation and impairs nitric oxide (NO) bioavailability by directly oxidizing NO or producing NO-consuming substrate radicals. Here, structurally diverse pharmacological agents with activities as MPO substrates/inhibitors or antioxidants were screened for their effects on MPO NO oxidase activity in human plasma and physiological model systems containing endogenous MPO substrates/antioxidants (tyrosine, urate, ascorbate)...
March 23, 2017: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28342532/shear-scaling-based-approach-for-irreversible-energy-loss-estimation-in-stenotic-aortic-flow-an-in-vitro-study
#5
Utku Gülan, Christian Binter, Sebastian Kozerke, Markus Holzner
Today, the functional and risk assessment of stenosed arteries is mostly based on ultrasound Doppler blood flow velocity measurements or catheter pressure measurements, which rely on several assumptions. Alternatively, blood velocity including turbulent kinetic energy (TKE) may be measured using MRI. The aim of the present study is to validate a TKE-based approach that relies on the fact that turbulence production is dominated by the flow's shear to determine the total irreversible energy loss from MRI scans...
March 12, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28340549/long-term-in-vivo-monitoring-of-adult-derived-human-liver-stem-progenitor-cells-by-bioluminescence-imaging-pet-and-contrast-enhanced-ct
#6
Mei-Ju Hsu, Julie Prigent, Pierre-Edouard Dollet, Joachim Ravau, Lionel Larbanoix, Gaetan Van Simaeys, Anne Bol, Vincent Grégoire, Serge Goldman, Gisèle Deblandre, Mustapha Najimi, Etienne Sokal, Catherine Lombard
Adult-derived human liver stem/progenitor cells (ADHLSCs) have the potential to alleviate liver injury. However, the optimal delivery route and long-term biodistribution of ADHLSCs remains unclear. In this paper, we used a triple fusion reporter system to determine the kinetic differences in the biodistribution of ADHLSCs following intrasplenic (IS) and intrahepatic (IH) administration in SCID-beige mice. ADHLSCs were transduced with a lentiviral vector expressing a triple-fusion reporter comprising renilla luciferase, monomeric red fluorescent protein and truncated HSV-1 thymidine kinase...
March 24, 2017: Stem Cells and Development
https://www.readbyqxmd.com/read/28340419/photolytic-degradation-of-the-%C3%AE-blocker-nebivolol-in-aqueous-solution
#7
Alaa Salma, Holger V Lutze, Torsten C Schmidt, Jochen Tuerk
Nebivolol (NEB) is one of the top-sold prescription drugs belonging to the third generation of beta-blockers. However, so far, occurrence data in the environment are lacking. Within this study NEB has been found for the first time in effluent samples of wastewater treatment plants in Germany with an average concentration of 13 ng L(-1). Its photodegradation behavior in the environment and in technical processes is largely unknown. To fill this gap, three different UV treatment procedures (UV-C at 254 nm, UV-B at 312 nm and UV-A at 365 nm) were investigated in three different matrices: pure water, pure water in presence of the hydroxyl radical (OH) scavenger tert...
March 13, 2017: Water Research
https://www.readbyqxmd.com/read/28338744/understanding-the-molecular-mechanism-of-substrate-channeling-and-domain-communication-in-protozoal-bifunctional-ts-dhfr
#8
Karen S Anderson
Most species, such as humans, have monofunctional forms of thymidylate synthase (TS) and dihydrofolate reductase (DHFR) that are key folate metabolism enzymes making critical folate components required for DNA synthesis. In contrast, several parasitic protozoa, including Leishmania majorg(Lm), Plasmodium falciparum (Pf), Toxoplasma gondii (Tg) and Cryptosporidium hominis(Ch), contain a unique bifunctional thymidylate synthase-dihydrofolate reductase (TS-DHFR) having the two sequential catalytic activities contained on a single polypeptide chain...
February 4, 2017: Protein Engineering, Design & Selection: PEDS
https://www.readbyqxmd.com/read/28335455/viral-protein-kinetics-of-piscine-orthoreovirus-infection-in-atlantic-salmon-blood-cells
#9
Hanne Merethe Haatveit, Øystein Wessel, Turhan Markussen, Morten Lund, Bernd Thiede, Ingvild Berg Nyman, Stine Braaen, Maria Krudtaa Dahle, Espen Rimstad
Piscine orthoreovirus (PRV) is ubiquitous in farmed Atlantic salmon (Salmo salar) and the cause of heart and skeletal muscle inflammation. Erythrocytes are important target cells for PRV. We have investigated the kinetics of PRV infection in salmon blood cells. The findings indicate that PRV causes an acute infection of blood cells lasting 1-2 weeks, before it subsides into persistence. A high production of viral proteins occurred initially in the acute phase which significantly correlated with antiviral gene transcription...
March 18, 2017: Viruses
https://www.readbyqxmd.com/read/28333683/kinetics-of-sub-spinodal-dewetting-of-thin-films-of-thickness-dependent-viscosity
#10
Tirumala Rao Kotni, Rajesh Khanna, Jayati Sarkar
An alternative explanation of the time varying and very low growth exponents in dewetting of polymer films like polystyrene films is presented based on non-linear simulations. The kinetics of these films is explored within the framework of experimentally observed thickness dependent viscosity. These films exhibit sub-spinodal dewetting via formation of satellite holes in between primary dewetted holes under favorable conditions of excess intermolecular forces and film thicknesses. We find that conditions responsible for sub-spinodal dewetting concurrently lead to remarkable changes in the kinetics of dewetting of even primary holes...
March 23, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28326765/a-change-in-the-rate-determining-step-of-polymerization-by-the-k289m-dna-polymerase-beta-cancer-associated-variant
#11
Khadijeh S Alnajjar, Beatriz Garcia-Barboza, Amirsoheil Negahbani, Maryam Nakhjiri, Boris A Kashemirov, Charles E McKenna, Myron F Goodman, Joann B Sweasy
K289M is a variant of DNA polymerase β (pol β) that was previously identified in colorectal cancer. The expression of this variant leads to a 16-fold increase in mutation frequency at a specific site <i>in vivo</i> and a reduction in fidelity <i>in vitro</i> in a sequence context-specific manner. Previous work shows that this reduction in fidelity results from decreased discrimination against incorrect nucleotide incorporation at the level of polymerization. To probe the transition state of the K289M mutator variant of pol β, single turnover kinetics experiments were performed using β,γ-CXY dGTP analogues with a wide range of leaving group monoacid dissociation constants (p<i>K</i><sub>a4</sub>), including a corresponding set of novel β,γ-CXY dCTP analogues...
March 22, 2017: Biochemistry
https://www.readbyqxmd.com/read/28323657/histology-and-gadolinium-distribution-in-the-rodent-brain-after-the-administration-of-cumulative-high-doses-of-linear-and-macrocyclic-gadolinium-based-contrast-agents
#12
Jessica Lohrke, Anna-Lena Frisk, Thomas Frenzel, Laura Schöckel, Martin Rosenbruch, Gregor Jost, Diana Constanze Lenhard, Martin A Sieber, Volker Nischwitz, Astrid Küppers, Hubertus Pietsch
OBJECTIVES: Retrospective studies in patients with primary brain tumors or other central nervous system pathologies as well as postmortem studies have suggested that gadolinium (Gd) deposition occurs in the dentate nucleus (DN) and globus pallidus (GP) after multiple administrations of primarily linear Gd-based contrast agents (GBCAs). However, this deposition has not been associated with any adverse effects or histopathological alterations. The aim of this preclinical study was to systematically examine differences between linear and macrocyclic GBCAs in their potential to induce changes in brain and skin histology including Gd distribution in high spatial resolution...
March 20, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28322781/characterization-of-akr1b16-a-novel-mouse-aldo-keto-reductase
#13
Joan Giménez-Dejoz, Susanne Weber, Oleg A Barski, Gabriele Möller, Jerzy Adamski, Xavier Parés, Sergio Porté, Jaume Farrés
Aldo-keto reductases (AKRs) are distributed in three families and multiple subfamilies in mammals. The mouse Akr1b3 gene is clearly orthologous to human AKR1B1, both coding for aldose reductase, and their gene products show similar tissue distribution, regulation by osmotic stress and kinetic properties. In contrast, no unambiguous orthologs of human AKR1B10 and AKR1B15.1 have been identified in rodents. Although two more AKRs, AKR1B7 and AKR1B8, have been identified and characterized in mouse, none of them seems to exhibit properties similar to the human AKRs...
March 17, 2017: Chemico-biological Interactions
https://www.readbyqxmd.com/read/28322561/accuracy-of-substrate-selection-by-enzymes-is-controlled-by-kinetic-discrimination
#14
Kinshuk Banerjee, Anatoly B Kolomeisky, Oleg A Igoshin
Enzymes have the remarkable ability to select the correct substrate from the pool of chemically similar molecules. The accuracy of such a selection is determined by differences in the free energy profiles for the right and wrong reaction pathways. Here, we investigate what features of the free energy landscape govern the variation and minimization of selectivity error. It is generally believed that minimal error is affected by both kinetic (activation barrier heights) and thermodynamic (binding stability) factors...
March 21, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28320505/fine-tuning-of-gene-expression-dynamics-by-the-set2-rpd3s-pathway
#15
Bo Bae Lee, Ji Hyun Kim, TaeSoo Kim
RNA polymerase II-interacting the Set2 methyltransferase co-transcriptionally methylates histone H3 at lysine 36 within the body of genes. This modification facilitates histone deacetylation by Rpd3S HDAC in 3' transcribed regions to suppress cryptic initiation and slow elongation. Although this pathway is important for global deacetylation, no strong effects on genome-wide transcription have been seen under optimized laboratory conditions. In contrast, this pathway slows the kinetics of mRNA induction when target genes are induced upon environmental changes...
March 21, 2017: BMB Reports
https://www.readbyqxmd.com/read/28317963/comparison-of-fast-electron-transfer-kinetics-at-platinum-gold-glassy-carbon-and-diamond-electrodes-using-fourier-transformed-ac-voltammetry-and-scanning-electrochemical-microscopy
#16
Sze-Yin Tan, Robert A Lazenby, Kiran Bano, Jie Zhang, Alan M Bond, Julie V Macpherson, Patrick R Unwin
Heterogeneous electron transfer (ET) processes at electrode/electrolyte interfaces are of fundamental and applied importance and are extensively studied by a range of electrochemical techniques, all of which have various attributes but also limitations. The present study focuses on the one-electron oxidation of tetrathiafulvalene (TTF) and reduction of tetracyanoquinodimethane (TCNQ) in acetonitrile solution by two powerful electrochemical techniques: Fourier-transformed large amplitude alternating current voltammetry (FTACV); and scanning electrochemical microscopy (SECM), both of which are supported by detailed theoretical models...
March 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28317480/novel-insights-into-complex-cardiovascular-pathologies-using-4d-flow-analysis-by-cardiovascular-magnetic-resonance-imaging
#17
Adam James Lewandowski, Betty Raman, Rajarshi Banerjee, Matteo Milanesi
BACKGROUND: It is essential that we are able to assess variations in blood flow in order to fully understand cardiovascular function in disease pathologies and for identification of individuals at long-term risk of cardiovascular disease development. Qualitative and quantitative assessments of blood flow by imaging modalities have been limited, and much of the accurate quantification has relied on invasive measures. METHODS: This review discusses how four-dimensional velocity cardiovascular magnetic resonance (4D flow CMR) offers increasing potential for the non-invasive assessment of blood flow in the heart and major blood vessels such as the aorta...
March 17, 2017: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/28317128/comparison-of-dce-mri-kinetic-parameters-and-fmiso-pet-uptake-parameters-in-head-and-neck-cancer-patients
#18
Urban Simoncic, Sara Leibfarth, Stefan Welz, Nina Schwenzer, Holger Schmidt, Gerald Reischl, Christina Pfannenberg, Christian la Fougère, Konstantin Nikolaou, Daniel Zips, Daniela Thorwarth
PURPOSE: Tumour hypoxia is a major cause of radiation resistance, often present in various solid tumours. Dynamic [(18) F]-fluoromisonidazole (FMISO) PET imaging is able to reliably assess tumour hypoxia. Comprehensive characterization of tumour microenvironment through FMISO-PET and dynamic contrast enhanced (DCE) MR multimodality imaging might be a valuable alternative to the dynamic FMISO-PET acquisition. The aim of this work was to explore the correlation between the FMISO-PET and DCE-MRI kinetic parameters...
March 20, 2017: Medical Physics
https://www.readbyqxmd.com/read/28316257/acute-kinematic-and-kinetic-adaptations-to-wearable-resistance-during-vertical-jumping
#19
Paul Macadam, Kim D Simperingham, John B Cronin, Grace Couture, Chloe Evison
One variation of vertical jump (VJ) training is resisted or weighted jump training, where wearable resistance (WR) enables jumping to be overloaded in a movement specific manner. A two-way analysis of variance with Bonferroni post hoc contrasts was used to determine the acute changes in VJ performance with differing load magnitudes and load placements. Kinematic and kinetic data were quantified using a force plate and contact mat. Twenty sport active subjects (age: 27.8 ± 3.8 years; body mass (BM): 70...
March 19, 2017: European Journal of Sport Science
https://www.readbyqxmd.com/read/28303908/disruption-of-autolysis-in-bacillus-subtilis-using-tio2-nanoparticles
#20
Eric McGivney, Linchen Han, Astrid Avellan, Jeanne VanBriesen, Kelvin B Gregory
In contrast to many nanotoxicity studies where nanoparticles (NPs) are observed to be toxic or reduce viable cells in a population of bacteria, we observed that increasing concentration of TiO2 NPs increased the cell survival of Bacillus subtilis in autolysis-inducing buffer by 0.5 to 5 orders of magnitude over an 8 hour exposure. Molecular investigations revealed that TiO2 NPs prevent or delay cell autolysis, an important survival and growth-regulating process in bacterial populations. Overall, the results suggest two potential mechanisms for the disruption of autolysis by TiO2 NPs in a concentration dependent manner: (i) directly, through TiO2 NP deposition on the cell wall, delaying the collapse of the protonmotive-force and preventing the onset of autolysis; and (ii) indirectly, through adsorption of autolysins on TiO2 NP, limiting the activity of released autolysins and preventing further lytic activity...
March 17, 2017: Scientific Reports
keyword
keyword
74488
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"