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https://www.readbyqxmd.com/read/28102286/chelerythrine-down-regulates-expression-of-vegfa-bcl2-and-kras-by-arresting-g-quadruplex-structures-at-their-promoter-regions
#1
Jagannath Jana, Soma Mondal, Payel Bhattacharjee, Pallabi Sengupta, Tanaya Roychowdhury, Pranay Saha, Pallob Kundu, Subhrangsu Chatterjee
A putative anticancer plant alkaloid, Chelerythrine binds to G-quadruplexes at promoters of VEGFA, BCL2 and KRAS genes and down regulates their expression. The association of Chelerythrine to G-quadruplex at the promoters of these oncogenes were monitored using UV absorption spectroscopy, fluorescence anisotropy, circular dichroism spectroscopy, CD melting, isothermal titration calorimetry, molecular dynamics simulation and quantitative RT-PCR technique. The pronounced hypochromism accompanied by red shifts in UV absorption spectroscopy in conjunction with ethidium bromide displacement assay indicates end stacking mode of interaction of Chelerythrine with the corresponding G-quadruplex structures...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101950/molecular-binding-of-toxic-phenothiazinium-derivatives-azures-to-bovine-serum-albumin-a-comparative-spectroscopic-calorimetric-and-in-silico-study
#2
Somnath Das, Md Maidul Islam, Gopal Chandra Jana, Anirudha Patra, Pradeep K Jha, Maidul Hossain
In this paper, the comparative binding behavior of antimalarial drug azure A, azure B and azure C with bovine serum albumin (BSA) has been studied. The interaction has been confirmed by multispectroscopic (UV, fluorescence, Fourier transform infrared (FT-IR), and circular dichroism) and molecular docking techniques. The experimental results show that azure B has the highest BSA binding affinity followed by azure A and azure C. The experimental evidence of binding showed a static quenching mechanism in the interaction azures with BSA...
January 19, 2017: Journal of Molecular Recognition: JMR
https://www.readbyqxmd.com/read/28101726/development-of-timolol-loaded-galactosylated-chitosan-nanoparticles-and-evaluation-of-their-potential-for-ocular-drug-delivery
#3
Ruobing Zhao, Jing Li, Jingyi Wang, Zhenya Yin, Yongtao Zhu, Wei Liu
This study was conducted to develop timolol maleate (TM)-loaded galactosylated chitosan (GC) nanoparticles (NPs) (TM-GC-NPs) followed by optimization via a four-level and three-factor Box-Behnken statistical experimental design. The optimized nanoparticles showed a particle size of 213.3 ± 6.83 nm with entrapment efficiency of 38.58 ± 1.31% and drug loading of 17.72 ± 0.28%. The NPs were characterized with respect to zeta potential, pH, surface morphology, and differential scanning calorimetry (DSC)...
January 18, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28101468/agglomeration-of-celecoxib-by-quasi-emulsion-solvent-diffusion-method-effect-of-stabilizer
#4
Maryam Maghsoodi, Ali Nokhodchi
Purpose: The quasi-emulsion solvent diffusion (QESD) has evolved into an effective technique to manufacture agglomerates of API crystals. Although, the proposed technique showed benefits, such as cost effectiveness, that is considerably sensitive to the choice of a stabilizer, which agonizes from a absence of systemic understanding in this field. In the present study, the combination of different solvents and stabilizers were compared to investigate any connections between the solvents and stabilizers. Methods: Agglomerates of celecoxib were prepared by QESD method using four different stabilizers (Tween 80, HPMC, PVP and SLS) and three different solvents (methyl acetate, ethyl acetate and isopropyl acetate)...
December 2016: Advanced Pharmaceutical Bulletin
https://www.readbyqxmd.com/read/28099336/prognostic-significance-of-nonprotein-respiratory-quotient-in-patients-with-liver-cirrhosis
#5
Hiroki Nishikawa, Hirayuki Enomoto, Yoshinori Iwata, Kyohei Kishino, Yoshihiro Shimono, Kunihiro Hasegawa, Chikage Nakano, Ryo Takata, Akio Ishii, Takashi Nishimura, Kazunori Yoh, Nobuhiro Aizawa, Yoshiyuki Sakai, Naoto Ikeda, Tomoyuki Takashima, Hiroko Iijima, Shuhei Nishiguchi
The aim of this study was to examine the effect of nonprotein respiratory quotient (npRQ), as assessed using indirect calorimetry, on clinical outcomes in patients with liver cirrhosis (LC). A total of 244 LC patients were evaluated in this study. For the univariate analysis, for each continuous variable, the optimal cutoff value that maximized the sum of sensitivity and specificity was selected using receiver operating curve (ROC) analysis for survival. There were 137 men and 107 women with the median (range) age of 67 (25-90) years...
January 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28098305/phase-behaviour-and-temperature-responsive-properties-of-a-gemini-surfactant-brij-30-water-system
#6
Chuanhong Han, Yan Guo, Xiaoxiao Chen, Meihuan Yao, Yingtian Zhang, Qirui Zhang, Xilian Wei
The phase behaviour of a ternary system composed of cationic gemini surfactant 2-hydroxypropyl-1,3-bis(myristyldimethylammonium chloride) (14-3(OH)-14(2Cl)), nonionic surfactant polyoxyethylene laurel ether (C12H25(OCH2CH2)10OH, Brij-30) and H2O was studied and its phase diagram was determined. In several different phase regions identified in the phase diagram, the viscoelastic worm-like micellar solution region was investigated. The focus of the investigation was the increase in the viscosity of the micellar solution with the temperature and the Brij-30 content, as suggested by a partial region of the triangular phase diagram...
January 18, 2017: Soft Matter
https://www.readbyqxmd.com/read/28097839/nutritional-assessment-of-a-population-with-a-history-of-childhood-craniopharyngioma-seen-at-hospital-prof-dr-juan-p-garrahan
#7
Carolina Caminiti, Carola Saure, Ilanit Bomer, Mercedes Brea, Javier González Ramos
INTRODUCTION: Craniopharyngiomas are histologically benign malformations located between the pituitary and hypothalamus that may affect key hormone secretion for endocrine regulation and satiety modulation. Although this is a relatively benign disease, the combination of severe hypothalamic obesity and associated comorbidities results in a reduced quality of life. OBJECTIVE: To assess the nutritional status of patients after craniopharyngioma surgery. POPULATION AND METHODS: Patients younger than 21 years old at the time of the study who required craniopharyngioma surgery at Hospital de Pediatr...
1, 2017: Archivos Argentinos de Pediatría
https://www.readbyqxmd.com/read/28097600/network-forming-nanoclusters-in-binary-as-s-se-glasses-from-ab-initio-quantum-chemical-modeling-to-experimental-evidences
#8
M Hyla
Network-forming As2(S/Se)m nanoclusters are employed to recognize expected variations in a vicinity of some remarkable compositions in binary As-Se/S glassy systems accepted as signatures of optimally constrained intermediate topological phases in earlier temperature-modulated differential scanning calorimetry experiments. The ab initio quantum chemical calculations performed using the cation-interlinking network cluster approach show similar oscillating character in tendency to local chemical decomposition but obvious step-like behavior in preference to global phase separation on boundary chemical compounds (pure chalcogen and stoichiometric arsenic chalcogenides)...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28095424/investigation-of-inclusion-complex-of-patchouli-alcohol-with-%C3%AE-cyclodextrin
#9
Fangfang Xu, Qiuxia Yang, Lilan Wu, Rui Qi, Yunshan Wu, Yucui Li, Lipeng Tang, De-An Guo, Bo Liu
The objective of this study was to improve the stability and water-solubility of patchouli alcohol by complexing with β-cyclodextrin (β-CD). The interactions between patchouli alcohol and β-CD were characterized by differential scanning calorimetry (DSC), Fourier transformation-infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and Scanning electron microscope (SEM), respectively. According to molecular modeling method, the enthalpy formation of host-guest illustrated the predominant configuration and the lowest value ΔbGo was -10...
2017: PloS One
https://www.readbyqxmd.com/read/28092039/calorimetric-measurement-of-sh2-domain-ligand-affinities
#10
Marissa A McKercher, Deborah S Wuttke
Isothermal titration calorimetry (ITC) has emerged as a leading approach in the characterization of protein/ligand interactions. This technique measures the heat change of a system upon binding of a ligand to a biomolecule, and thereby requires no immobilization, intrinsic fluorescence, or labeling of any kind of either species. If properly designed, a single experiment can not only measure the binding affinity, but also determine additional binding and thermodynamic parameters, including the enthalpy, entropy, and the stoichiometry of the interaction...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28091670/enhanced-temperature-effect-of-electrorheological-fluid-based-on-cross-linked-poly-ionic-liquid-particles-rheological-and-dielectric-relaxation-studies
#11
Yang Liu, Jinhua Yuan, Yuezhen Dong, Xiaopeng Zhao, Jianbo Yin
Recent research of using poly(ionic liquid) (PIL) particles as the dispersal phase has provided a new strategy to develop a high-performance anhydrous polyelectrolyte-based electrorheological (ER) fluid. However, the working temperature range of the ER fluid of PIL particles is still narrow due to an inherently low glass transfer temperature caused by the plasticization of polyatomic organic counter ions in PILs. In this paper, we develop a new ER system based on cross-linked PIL (C-PIL) particles and demonstrate that crosslinking with a suitable degree only slightly degrades the ER properties but significantly improves the working temperature range of the ER fluid of PIL particles...
January 16, 2017: Soft Matter
https://www.readbyqxmd.com/read/28090638/late-gestational-intermittent-hypoxia-induces-metabolic-and-epigenetic-changes-in-male-adult-offspring-mice
#12
Abdelnaby Khalyfa, Rene Cortese, Zhuanhong Qiao, Honggang Ye, Riyue Bao, Jorge Andrade, David Gozal
Pregnancy, particularly late gestation, has been associated with a relatively high prevalence of obstructive sleep apnea (OSA). Intermittent hypoxia (IH), a hallmark of OSA, could impose significant long-term effects on somatic growth, energy homeostasis, and metabolic function in offspring. We hypothesized that IH during late pregnancy (LG-IH) may increase the propensity for metabolic dysregulation and obesity in adult offspring via epigenetic modifications. Time-pregnant female C57BL/6 mice were exposed to LG-IH or room air (LG-RA) during days 13-18 of gestation...
January 15, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28090612/quantum-chemical-study-and-isothermal-titration-calorimetry-of-%C3%AE-cyclodextrin-complexes-with-mianserin-in-aqueous-solution
#13
Anna Ignaczak, Bartłomiej Pałecz, Sylwia Belica-Pacha
β-Cyclodextrin (β-CD) is studied as a carrier of the drug mianserin (MIA). β-CD with MIA adducts with 1 : 1 and 2 : 1 stoichiometry are investigated in vacuo and in water using quantum chemical methods: PM6 and B3LYP/6-31G(d,p). An effect of the dispersion correction GD2 and the basis set superposition error on the complexation energies is also evaluated. Additionally, the interaction between MIA hydrochloride and β-CD in aqueous solution at 298.15 K is examined experimentally by isothermal titration calorimetry...
January 16, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28089448/structural-basis-for-the-interaction-of-a-human-small-heat-shock-protein-with-the-14-3-3-universal-signaling-regulator
#14
Nikolai N Sluchanko, Steven Beelen, Alexandra A Kulikova, Stephen D Weeks, Alfred A Antson, Nikolai B Gusev, Sergei V Strelkov
By interacting with hundreds of protein partners, 14-3-3 proteins coordinate vital cellular processes. Phosphorylation of the small heat shock protein, HSPB6, within its intrinsically disordered N-terminal domain activates its interaction with 14-3-3, ultimately triggering smooth muscle relaxation. After analyzing the binding of an HSPB6-derived phosphopeptide to 14-3-3 using isothermal calorimetry and X-ray crystallography, we have determined the crystal structure of the complete assembly consisting of the 14-3-3 dimer and full-length HSPB6 dimer and further characterized this complex in solution using fluorescence spectroscopy, small-angle X-ray scattering, and limited proteolysis...
December 30, 2016: Structure
https://www.readbyqxmd.com/read/28088635/mucoadhesive-amorphous-solid-dispersions-for-sustained-release-of-poorly-water-soluble-drugs
#15
Justin S LaFountaine, Leena Kumari Prasad, Dave A Miller, James W McGinity, Robert O Williams
The oral delivery of mucoadhesive patches has been shown to enhance the absorption of large molecules such as peptides. We hypothesized that this mechanism could have utility for poorly soluble small molecules by utilizing a mucoadhesive polymer as the matrix for an amorphous solid dispersion. Binary dispersions of itraconazole and carbomer (Carbopol 71G) were prepared utilizing a thermokinetic mixing process (KinetiSol Dispersing) and the physicochemical properties were investigated by powder x-ray diffraction, calorimetry, and liquid chromatography...
January 11, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28088456/development-of-a-predictive-model-for-the-long-term-stability-assessment-of-drug-in-adhesive-transdermal-films-using-polar-pressure-sensitive-adhesives-as-carrier-matrix
#16
Clémence Chenevas-Paule, Hans-Michael Wolff, Mark Ashton, Martin Schubert, Kalliopi Dodou
Drug crystallization in transdermal drug delivery systems (TDDS) is a critical quality defect. The impact of drug load and hydration on the physical stability of polar (acrylic) drug-in-adhesive (DIA) films was investigated with the objective to identify predictive formulation parameters with respect to drug solubility and long-term stability. Medicated acrylic films were prepared over a range of drug concentrations below and above saturation solubility; and were characterized by FTIR, differential scanning calorimetry (DSC), polarized microscopy and Dynamic Vapor Sorption (DVS) analysis...
January 11, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28088005/nicotine-hydrogen-tartrate-loaded-chitosan-nanoparticles-formulation-characterization-and-in-vitro-delivery-from-dry-powder-inhaler-formulation
#17
Hui Wang, Graeme George, Selena Bartlett, Changyou Gao, Nazrul Islam
This study reports the development of nanoparticles in the form of inhalable micro-aggregates of biodegradable chitosan (CS) loaded with nicotine hydrogen tartrate (NHT) for potential pulmonary delivery of nicotine from dry powder inhaler (DPI) formulations with prolonged release profile. The NHT-loaded CS particles were prepared using a water-in-oil emulsion crosslinking method. The prepared particles were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for morphological studies; Zetasizer and Mastersizer were applied for particle size analysis...
January 11, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28087261/dna-aptamer-probes-for-detection-of-estrogen-receptor-%C3%AE-positive-carcinomas
#18
Arghya Sett, Bibhuti Bhusan Borthakur, Jagannath Dev Sharma, Amal Chandra Kataki, Utpal Bora
Estrogen receptor alpha (ERα) which is a ligand-activated transcription factor also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1). It is an important biomarker for breast cancer metastasis. In the present study, we report a novel DNA aptamer candidate against estrogen receptor (ER) alpha structure. The enriched aptamer candidate was obtained after 14 iterative cycles of in vitro protein-SELEX process. Isothermal calorimetry study suggests the nanomolar sensitivity of the candidate ER_Apt1 to its target protein...
December 25, 2016: Translational Research: the Journal of Laboratory and Clinical Medicine
https://www.readbyqxmd.com/read/28077884/chemical-vs-physical-acceleration-of-cement-hydration
#19
Dale P Bentz, Franco Zunino, Didier Lootens
Cold weather concreting often requires the use of chemical accelerators to speed up the hydration reactions of the cement, so that setting and early-age strength development will occur in a timely manner. While calcium chloride (dihydrate - CaCl2·2H2O) is the most commonly used chemical accelerator, recent research using fine limestone powders has indicated their high proficiency for physically accelerating early-age hydration and reducing setting times. This paper presents a comparative study of the efficiency of these two approaches in accelerating hydration (as assessed via isothermal calorimetry), reducing setting times (Vicat needle), and increasing early-age mortar cube strength (1 d and 7 d)...
November 2016: Concr Int
https://www.readbyqxmd.com/read/28076814/gsmtx4-mechanism-of-inhibiting-mechanosensitive-ion-channels
#20
Radhakrishnan Gnanasambandam, Chiranjib Ghatak, Anthony Yasmann, Kazuhisa Nishizawa, Frederick Sachs, Alexey S Ladokhin, Sergei I Sukharev, Thomas M Suchyna
GsMTx4 is a spider venom peptide that inhibits cationic mechanosensitive channels (MSCs). It has six lysine residues that have been proposed to affect membrane binding. We synthesized six analogs with single lysine-to-glutamate substitutions and tested them against Piezo1 channels in outside-out patches and independently measured lipid binding. Four analogs had ∼20% lower efficacy than the wild-type (WT) peptide. The equilibrium constants calculated from the rates of inhibition and washout did not correlate with the changes in inhibition...
January 10, 2017: Biophysical Journal
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