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https://www.readbyqxmd.com/read/28102735/bulk-immunoassays-for-analysis-of-extracellular-vesicles
#1
Frank A W Coumans, Elmar L Gool, Rienk Nieuwland
There is increasing clinical interest in extracellular vesicles (EV) for diagnostic and treatment purposes. This review provides an overview of bulk immunoassays to analyse EV. Western blot and enzyme-linked immunosorbent assay are still the two predominant bulk immunoassays. Recently, new assays have become available that can detect exposure to EV concentrations that are up to 10,000-fold lower. This is advantageous for applications that detect rare EV. Other important parameters are the detectable concentration range, the required sample volume, whether simultaneous presence of different antigens on a single EV can be detected, size selectivity of each assay and practical considerations...
January 19, 2017: Platelets
https://www.readbyqxmd.com/read/28102680/ionicity-of-protic-ionic-liquid-quantitative-measurement-by-spectroscopic-methods
#2
Minming Shen, Yuyang Zhang, Kaizhou Chen, Siying Che, Jia Yao, Haoran Li
The ionicity value, which is a key property of protic ionic liquids, was obtained by the attenuated total reflection Fourier transform infrared spectroscopy and nuclear magnetic resonance respectively for a protic ionic liquid: n-propylammonium acetate. The method of potentiometric titration is found not suitable for such kind of ionic liquid as the ∆pKa of the compositing acid and base is relatively small. In the IR spectrum, molecular species can be directly observed in the range 1200-1800 cm-1, and the ratio of ionic and molecular species can be quantitatively calculated by the area of characteristic absorption peaks calibrated by standard curve from NaAc/HAc solutions...
January 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28102665/cosolute-and-crowding-effects-on-a-side-by-side-protein-dimer
#3
Alex J Guseman, Gary J Pielak
The effects of small (~102 Da) and larger (>103 Da) cosolutes on protein stability are broadly understood: excluding volume stabilizes proteins, and chemical interactions are stabilizing when repulsive, but destabilizing when attractive. Proteins, however, rarely work alone. Here, we investigate the effects of small and larger cosolutes on the equilibrium stability of the simplest defined protein-protein interactions, the side-by-side homodimer formed by the A34F variant of the 56-residue B1 domain of protein G...
January 19, 2017: Biochemistry
https://www.readbyqxmd.com/read/28100626/effect-of-metformin-on-metabolites-and-relation-with-myocardial-infarct-size-and-left-ventricular-ejection-fraction-after-myocardial-infarction
#4
Ruben N Eppinga, Daniel Kofink, Robin P F Dullaart, Geertje W Dalmeijer, Erik Lipsic, Dirk J van Veldhuisen, Iwan C C van der Horst, Folkert W Asselbergs, Pim van der Harst
BACKGROUND: Left ventricular ejection fraction (LVEF) and infarct size (ISZ) are key predictors of long-term survival after myocardial infarction (MI). However, little is known about the biochemical pathways driving LV dysfunction after MI. To identify novel biomarkers predicting post-MI LVEF and ISZ, we performed metabolic profiling in the GIPS-III randomized clinical trial (Glycometabolic Intervention as Adjunct to Primary Percutaneous Intervention in ST Elevation Myocardial Infarction)...
February 2017: Circulation. Cardiovascular Genetics
https://www.readbyqxmd.com/read/28098776/distinguishing-benign-from-malignant-pancreatic-and-periampullary-lesions-using-combined-use-of-%C3%A2-h-nmr-spectroscopy-and-gas-chromatography-mass-spectrometry
#5
Yarrow J McConnell, Farshad Farshidfar, Aalim M Weljie, Karen A Kopciuk, Elijah Dixon, Chad G Ball, Francis R Sutherland, Hans J Vogel, Oliver F Bathe
Previous work demonstrated that serum metabolomics can distinguish pancreatic cancer from benign disease. However, in the clinic, non-pancreatic periampullary cancers are difficult to distinguish from pancreatic cancer. Therefore, to test the clinical utility of this technology, we determined whether any pancreatic and periampullary adenocarcinoma could be distinguished from benign masses and biliary strictures. Sera from 157 patients with malignant and benign pancreatic and periampullary lesions were analyzed using proton nuclear magnetic resonance (¹H-NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS)...
January 13, 2017: Metabolites
https://www.readbyqxmd.com/read/28098763/new-abietane-and-kaurane-type-diterpenoids-from-the-stems-of-tripterygium-regelii
#6
Dongsheng Fan, Shuangyan Zhou, Zhiyuan Zheng, Guo-Yuan Zhu, Xiaojun Yao, Ming-Rong Yang, Zhi-Hong Jiang, Li-Ping Bai
Eleven new abietane type (1‒11), and one new kaurane (12), diterpenes, together with eleven known compounds (13-23), were isolated and identified from the stems of Tripterygium regelii, which has been used as a traditional folk Chinese medicine for the treatment of rheumatoid arthritis in China. The structures of new compounds were characterized by means of the interpretation of high-resolution electrospray ionization mass spectrometry (HRESIMS), extensive nuclear magnetic resonance (NMR) spectroscopic data and comparisons of their experimental CD spectra with calculated electronic circular dichroism (ECD) spectra...
January 13, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28098279/eu-3-doped-y3-xndxal3o12-garnet-synthesis-and-structural-investigation
#7
L Pavasaryte, A Katelnikovas, V Klimavicius, V Balevicius, A Krajnc, G Mali, J Plavec, A Kareiva
Nd(3+)-Doped yttrium aluminium garnet and Eu(3+)-Nd(3+)-co-doped yttrium aluminium garnet were synthesized using an environmentally friendly sol-gel method at low temperatures. The results of X-ray diffraction (XRD) analysis of the powders sintered at 1000 °C showed the purity and formation of monophasic compounds. The phase composition and purity confirmation of the samples were also characterized via FTIR spectroscopy. Desirable microstructural features and particle size of phosphorous materials of the polycrystalline samples were studied via scanning electron microscopy (SEM)...
January 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28098267/a-tailored-multi-frequency-epr-approach-to-accurately-determine-the-magnetic-resonance-parameters-of-dynamic-nuclear-polarization-agents-application-to-amupol
#8
P Gast, D Mance, E Zurlo, K L Ivanov, M Baldus, M Huber
To understand the dynamic nuclear polarization (DNP) enhancements of biradical polarizing agents, the magnetic resonance parameters need to be known. We describe a tailored EPR approach to accurately determine electron spin-spin coupling parameters using a combination of standard (9 GHz), high (95 GHz) and ultra-high (275 GHz) frequency EPR. Comparing liquid- and frozen-solution continuous-wave EPR spectra provides accurate anisotropic dipolar interaction D and isotropic exchange interaction J parameters of the DNP biradical AMUPol...
January 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28098142/carbon-translocation-from-a-plant-to-an-insect-pathogenic-endophytic-fungus
#9
Scott W Behie, Camila C Moreira, Irina Sementchoukova, Larissa Barelli, Paul M Zelisko, Michael J Bidochka
Metarhizium robertsii is a common soil fungus that occupies a specialized ecological niche as an endophyte and an insect pathogen. Previously, we showed that the endophytic capability and insect pathogenicity of Metarhizium are coupled to provide an active method of insect-derived nitrogen transfer to a host plant via fungal mycelia. We speculated that in exchange for this insect-derived nitrogen, the plant would provide photosynthate to the fungus. By using (13)CO2, we show the incorporation of (13)C into photosynthate and the subsequent translocation of (13)C into fungal-specific carbohydrates (trehalose and chitin) in the root/endophyte complex...
January 18, 2017: Nature Communications
https://www.readbyqxmd.com/read/28097855/-prolapsed-ureterocele-a-diagnosis-to-be-considered-for-a-vulvar-mass-in-an-infant-case-report
#10
Marita Lardón Fernández, José Uberos Fernández, Francisco Moreno Madrid
Ureterocele is a relatively common malformation of the urinary system in children; however, the ureterocele prolapse through the urethra is an extremely rare presentation. Urological nuclear magnetic resonance is the test of choice for definitive diagnosis. Initial treatment of a prolapsed ureterocele involves decompression of the mass. We report the case of a 7-month-old infant with duplication of the collecting system and right ectopic ureterocele appearing as a vulvar mass.
1, 2017: Archivos Argentinos de Pediatría
https://www.readbyqxmd.com/read/28096310/characterization-of-the-dtdp-fuc3n-and-dtdp-qui3n-biosynthetic-pathways-in-campylobacter-jejuni-81116%C3%A2
#11
Zack Z Li, Alexander S Riegert, Marie-France Goneau, Anna M Cunningham, Evgeny Vinogradov, Jianjun Li, Ian C Schoenhofen, James B Thoden, Hazel M Holden, Michel Gilbert
The Gram-negative bacterium Campylobacter jejuni 81116 (Penner serotype HS:6) has a class E lipooligosaccharide (LOS) biosynthesis locus containing 19 genes, which encode for 11 putative glycosyltransferases, 1 lipid A acyltransferase and 7 enzymes thought to be involved in the biosynthesis of dideoxyhexosamine (ddHexN) moieties. Although the LOS outer core structure of C. jejuni 81116 is still unknown, recent mass spectrometry analyses suggest that it contains acetylated forms of two ddHexN residues. For this investigation, five of the genes encoding enzymes reportedly involved in the biosyntheses of these sugar residues were examined, rmlA, rmlB, wlaRA, wlaRB and wlaRG Specifically, these genes were cloned and expressed in Escherichia coli, and the corresponding enzymes were purified and tested for biochemical activity...
January 16, 2017: Glycobiology
https://www.readbyqxmd.com/read/28095303/gd-dtpa-induced-dynamic-metabonomic-changes-in-rat-biofluids
#12
Chuanling Wan, Youyang Zhan, Rong Xue, Yijie Wu, Xiaojing Li, Fengkui Pei
OBJECTIVES: The purposes of this study were (1) to detect the dynamic metabonomic changes induced by gadopentetate dimeglumine (Gd-DTPA) and (2) to investigate the potential metabolic disturbances associated with the pathogenesis of nephrogenic systemic fibrosis (NSF) at the early stage. METHODS: A nuclear magnetic resonance (NMR)-based metabolomics approach was used to investigate the urinary and serum metabolic changes induced by a single tail vein injection of Gd-DTPA (dosed at 2 and 5mmol/kg body weight) in rats...
January 14, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28094138/new-normoxic-n-hydroxymethyl-acrylamide-based-polymer-gel-for-3d-dosimetry-in-radiation-therapy
#13
Khalid A Rabaeh, Ahmed A Basfar, Akram A Almousa, Slobodan Devic, Belal Moftah
A novel composition of normoxic polymer gel dosimeters based on radiation-induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) is introduced in this study for 3D dosimetry for Quality Assurance (QA) in radiation therapy. Dosimeters were irradiated by 6, 10 and 18MV photon beams of a medical linear accelerator at various dose rates to doses of up to 20Gy. The dose response of polymer gel dosimeters was studied using nuclear magnetic resonance (NMR) spin-spin relaxation rate (R2) of hydrogen protons within the water molecule...
January 13, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28093594/fast-and-accurate-mas-dnp-simulations-of-large-spin-ensembles
#14
Frédéric Mentink-Vigier, Shimon Vega, Gaël De Paëpe
A deeper understanding of parameters affecting Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP), an emerging nuclear magnetic resonance hyperpolarization method, is crucial for the development of new polarizing agents and the successful implementation of the technique at higher magnetic fields (>10 T). Such progress is currently impeded by computational limitation which prevents the simulation of large spin ensembles (electron as well as nuclear spins) and to accurately describe the interplay between all the multiple key parameters at play...
January 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28093330/effect-of-solution-plasma-process-with-bubbling-gas-on-physicochemical-properties-of-chitosan
#15
Fengming Ma, Pu Li, Baiqing Zhang, Qun Fu, Zhenyu Wang, Cailian Gu
In the present work, solution plasma process (SPP) with bubbling gas was used to prepare oligochitosan. The effect of SPP irradiation with bubbling gas on the degradation of chitosan was evaluated by the intrinsic viscosity reduction rate and the degradation kinetic. The formation of OH radical was studied. Changes of the physicochemical properties of chitosan were measured by scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis, as well as ultraviolet-visible, Fourier-transform infrared, and (13)C nuclear magnetic resonance spectroscopy...
January 13, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28093096/structural-biology-of-supramolecular-assemblies-by-magic-angle-spinning-nmr-spectroscopy
#16
Caitlin M Quinn, Tatyana Polenova
In recent years, exciting developments in instrument technology and experimental methodology have advanced the field of magic-angle spinning (MAS) nuclear magnetic resonance (NMR) to new heights. Contemporary MAS NMR yields atomic-level insights into structure and dynamics of an astounding range of biological systems, many of which cannot be studied by other methods. With the advent of fast MAS, proton detection, and novel pulse sequences, large supramolecular assemblies, such as cytoskeletal proteins and intact viruses, are now accessible for detailed analysis...
January 2017: Quarterly Reviews of Biophysics
https://www.readbyqxmd.com/read/28092975/characterisation-of-the-antiproliferative-constituents-and-activity-of-ficus-exasperata-vahl-on-ovarian-cancer-cells-a-preliminary-investigation
#17
Enitome E Bafor, Jennifer McKenna, Edward G Rowan, RuAngelie Edrada-Ebel
Ovarian cancer is one of the most common gynaecological cancers today. This study therefore investigates the anticancer effects of Ficus exasperata extracts and fractions on ovarian cancer cells. The antiproliferative activity of the crude extracts (1 mg/mL) was assessed using the MTT assay on A2780 (ovarian cancer) cell line. Bio-activity guided fractionation was performed and preliminary identification was further achieved using high resolution mass spectrometry and nuclear magnetic resonance spectroscopy...
January 17, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28092038/nmr-chemical-shift-mapping-of-sh2-peptide-interactions
#18
Marissa A McKercher, Deborah S Wuttke
Heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) experiments offer a rapid and high resolution approach to gaining binding and conformational insights into a protein-peptide interaction. By tracking (1)H and (15)N chemical shift changes over the course of a peptide titration into isotopically labeled protein, amide NH pairs of amino acids whose chemical environment changes upon peptide binding can be identified. When mapped onto a structure of the protein, this approach can identify the peptide-binding interface or regions undergoing conformation changes within a protein upon ligand binding...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28092037/structural-characterization-of-monomeric-dimeric-state-of-p59-fyn-sh2-domain
#19
Radu Huculeci, Fabien Kieken, Abel Garcia-Pino, Lieven Buts, Nico van Nuland, Tom Lenaerts
Src homology 2 (SH2) domains are key modulators in various signaling pathways allowing the recognition of phosphotyrosine sites of different proteins. Despite the fact that SH2 domains acquire their biological functions in a monomeric state, a multitude of reports have shown their tendency to dimerize. Here, we provide a technical description on how to isolate and characterize by gel filtration, circular dichroism (CD), and nuclear magnetic resonance (NMR) each conformational state of p59(fyn) SH2 domain.
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28090774/biakamides-a-d-unique-polyketides-from-a-marine-sponge-act-as-selective-growth-inhibitors-of-tumor-cells-adapted-to-nutrient-starvation
#20
Naoyuki Kotoku, Ryosuke Ishida, Hirokazu Matsumoto, Masayoshi Arai, Kazunari Toda, Andi Setiawan, Osamu Muraoka, Motomasa Kobayashi
Biakamides A-D, novel unusually unique polyketides, were isolated from an Indonesian marine sponge (Petrosaspongia sp.) with a constructed bioassay using PANC-1 human pancreatic cancer cells. Through detailed analyses of the one- and two-dimensional nuclear magnetic resonance (NMR) spectra of biakamides, planar chemical structures possessing a terminal thiazole, two N-methyl amides, a chloromethylene, and a substituted butyryl moiety were obtained. After elucidation of the configuration of the secondary alcohol moiety in biakamides A and B, the absolute stereostructures of the two secondary methyl groups in biakamides A-D were determined by the asymmetric total syntheses of all possible stereoisomers from the optically pure monoprotected 2,4-dimethyl-1,5-diol...
January 16, 2017: Journal of Organic Chemistry
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