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https://www.readbyqxmd.com/read/28430241/probing-the-germination-kinetics-of-ethanol-treated-bacillus-thuringiensis-spores
#1
Guiwen Wang, Huanjun Chen, Xiaochun Wang, Lixin Peng, Yuan Peng, Yong-Qing Li
Bacillus thuringiensis (Bt) is the most widely used microbial insecticide. To clarify the mechanism of bacterial resistance to ethanol toxicity, the present study investigated the effects of 70% (v/v) ethanol at a moderate temperature (65°C) on Bt spore germination by single-cell Raman spectroscopy and differential interference contrast microscopy. We found that over 80% of Bt spores were inviable after 30 min of treatment. Moreover, ethanol treatment affected spore germination; the time for initiation of rapid calcium dipicolinate (CaDPA) release (i...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28429794/bone-in-culture-array-as-a-platform-to-model-early-stage-bone-metastases-and-discover-anti-metastasis-therapies
#2
Hai Wang, Lin Tian, Amit Goldstein, Jun Liu, Hin-Ching Lo, Kuanwei Sheng, Thomas Welte, Stephen T C Wong, Zbigniew Gugala, Fabio Stossi, Chenghang Zong, Zonghai Li, Michael A Mancini, Xiang H-F Zhang
The majority of breast cancer models for drug discovery are based on orthotopic or subcutaneous tumours. Therapeutic responses of metastases, especially microscopic metastases, are likely to differ from these tumours due to distinct cancer-microenvironment crosstalk in distant organs. Here, to recapitulate such differences, we established an ex vivo bone metastasis model, termed bone-in-culture array or BICA, by fragmenting mouse bones preloaded with breast cancer cells via intra-iliac artery injection. Cancer cells in BICA maintain features of in vivo bone micrometastases regarding the microenvironmental niche, gene expression profile, metastatic growth kinetics and therapeutic responses...
April 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28429004/binding-site-opening-by-loop-c-shift-and-chloride-ion-pore-interaction-in-the-gabaa-receptor-model
#3
M A Michałowski, S Kraszewski, J W Mozrzymas
GABAA receptors (GABAARs) are crucial in mediating inhibition in the adult mammalian brain. Although the kinetics of this receptor has been extensively studied, the molecular picture of interactions occurring at various channel conformations remains elusive. While electrophysiology combined with mutagenesis sheds light on the role of specific residues, ultrastructural studies reveal static structures which, in the case of GABAARs, are limited to the β3 homomer. To take advantage of the newest crystal structures of cys-loop receptors, a homology model of α1β2γ2 GABAAR in the unbound closed state was built using a template of the homomeric glycine receptor in the closed state...
April 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28428786/challenge-of-humans-with-wild-type-salmonella-enterica-serovar-typhi-elicits-changes-in-the-activation-and-homing-characteristics-of-mucosal-associated-invariant-t-cells
#4
Rosângela Salerno-Goncalves, David Luo, Stephanie Fresnay, Laurence Magder, Thomas C Darton, Claire Jones, Claire S Waddington, Christoph J Blohmke, Brian Angus, Myron M Levine, Andrew J Pollard, Marcelo B Sztein
Gastrointestinal infections by Salmonella enterica serovar Typhi (S. Typhi) are rare in industrialized countries. However, they remain a major public health problem in the developing world with an estimated 26.9 million new cases annually and significant mortality when untreated. Recently, we provided the first direct evidence that CD8(+) MAIT cells are activated and have the potential to kill cells exposed to S. Typhi, and that these responses are dependent on bacterial load. However, MAIT cell kinetics and function during bacterial infections in humans remain largely unknown...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28427122/-application-on-the-quantitative-perfusion-parameters-of-dynamic-contrast-enhanced-mri-in-the-pathological-subtype-of-uterine-leiomyoma
#5
J Zheng, Z H Zhao, J F Yang, L Zhao, L M Yang, H J Hu
Objective: To analyze the value of the quantitative perfusion parameters of dynamic contrast-enhanced MRI(DCE-MRI) in the pathological subtype of uterine leiomyoma. Methods: A total of 35 cases of uterine leiomyoma confirmed by surgery and pathology were retrospectively analyzed in Shaoxing People's Hospital from October 2015 to May 2016.All cases underwent DCE-MRI. Quantitative perfusion parameters were prospectively measured and analyzed, including transfer constant (K(trans)) , efflux rate constant (K(ep)), extravascular extracellular space volume ratio (V(e)), blood plasma volume ratio (V(p)), permeability surface area product (PS) and plasma flow (F(p)) , using signal-input two-compartment tracer kinetic models (Extended Tofts model and Exchange model) in 35 leiomyoma cases...
April 18, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/28426227/monovalent-vs-divalent-cation-diffusion-in-thiospinel-ti2s4
#6
Patrick Bonnick, Xiaoqi Sun, Ka-Cheong Lau, Chen Liao, Linda F Nazar
Measurement of Li+ and Mg2+ diffusion in the same Ti2S4 thiospinel material in three electrode cells at elevated temperature negates factors of surface area and cell design, allowing the direct comparison of their diffusion coefficients (D). D values were measured using the Galvanic Intermittent Titration Technique (GITT) as a function of both ion concentration (x) and temperature. During discharge at 55 °C, DLi descends gradually from 2×10-8 cm2/s by an order of magnitude over the range 0 < xLi < 1...
April 20, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28425758/agreement-between-mri-and-pathologic-analyses-for-determination-of-tumor-size-and-correlation-with-immunohistochemical-factors-of-invasive-breast-carcinoma
#7
Eun Young Yoo, Sang Yu Nam, Hye-Young Choi, Min Ji Hong
Background There may be discordance between tumor size determined by magnetic resonance imaging (MRI) and that observed during pathologic analyses. Purpose To evaluate MRI-pathology concordance of tumor size in patients with invasive breast carcinoma. Material and Methods Data from 307 invasive breast carcinomas were analyzed retrospectively. Preoperative breast MRI was reviewed for size, lesion type, morphology, and dynamic contrast-enhanced tumor kinetics. MRI tumor size was compared with tumor size measurements from the pathologic analysis...
January 1, 2017: Acta Radiologica
https://www.readbyqxmd.com/read/28425293/cosensitized-porphyrin-system-for-high-performance-solar-cells-with-tof-sims-analysis
#8
Wenjun Wu, Huaide Xiang, Wei Fan, Jinglin Wang, Haifeng Wang, Xin Hua, Zhaohui Wang, Yi-Tao Long, He Tian, Wei-Hong Zhu
Up to date, development of organic sensitizers has been predominately focused on light harvesting, HOMO and LUMO energy levels, and electron transferring process. In contrast, their adsorption mode as well as dynamic loading behaviour onto nanoporous TiO2 is rarely considered. Herein we have employed the time of flight secondary ion mass spectrometry (TOF-SIMS) to take insight into the competitive dye adsorption mode and kinetics in cosensitized porphyrin system. Using the novel porphyrin dye FW-1 and D-A-π-A featured dye WS-5, the different bond-breaking mode in TOF-SIMS and dynamic dye-loading amount during the coadsorption process are well compared with two different anchoring groups such as benzoic acid and cyanoacrylic acid...
April 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28425048/biopsy-targeting-with-dynamic-contrast-enhanced-versus-standard-neuronavigation-mri-in-glioma-a-prospective-double-blinded-evaluation-of-selection-benefits
#9
Vera C Keil, Bogdan Pintea, Gerrit H Gielen, Susanne Greschus, Rolf Fimmers, Jürgen Gieseke, Matthias Simon, Hans H Schild, Dariusch R Hadizadeh
Current biopsy planning based on contrast-enhanced T1W (CET1W) or FLAIR sequences frequently delivers biopsy samples that are not in concordance with the gross tumor diagnosis. This study investigates whether the quantitative information of transfer constant K(trans) maps derived from T1W dynamic contrast-enhanced MRI (DCE-MRI) can help enhance the quality of biopsy target selection in glioma. 28 patients with suspected glioma received MRI including DCE-MRI and a standard neuronavigation protocol of 3D FLAIR- and CET1W data sets (0...
April 19, 2017: Journal of Neuro-oncology
https://www.readbyqxmd.com/read/28415842/spectrophotometric-quantification-of-peroxidase-with-p-phenylene-diamine-for-analyzing-peroxidase-encapsulating-lipid-vesicles
#10
Ya Zhang, Yannick R F Schmid, Sandra Luginbühl, Qiang Wang, Petra S Dittrich, Peter Walde
A spectrophotometric assay for the determination of horseradish peroxidase (HRP) in aqueous solution with p-phenylenediamine (PPD, benzene-1,4-diamine) as electron donor substrate and hydrogen peroxide (H2O2) as oxidant was developed. The oxidation of PPD by HRP/H2O2 leads to the formation of Bandrowski's base ((3E,6E)-3,6-bis[(4-aminophenyl)imino]cyclohexa-1,4-diene-1,4-diamine), which can be quantified by following the increase in absorbance at 500 nm. The assay was applied for monitoring the activity of HRP inside ≈180 nm-sized lipid vesicles (liposomes), prepared from POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and purified by size exclusion chromatography...
April 17, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28415037/enantiomer-specific-accumulation-and-depuration-of-%C3%AE-hexabromocyclododecane-%C3%AE-hbcdd-in-chicken-gallus-gallus-as-a-tool-to-identify-contamination-sources
#11
Elsa Omer, Ronan Cariou, Adeline Huneau-Salaün, Gaud Dervilly-Pinel, Élisabeth Baéza, Angélique Travel, Sophie Le Bouquin, Catherine Jondreville, Bruno Le Bizec
A LC-ESI(-)-HRMS method dedicated to the analysis of 6 HBCDD enantiomers at trace levels in animal matrices was developed, using a cellulose based stationary phase with a particle size of 2.5 μm. This method was applied to a sample set derived from a kinetic study of α-HBCDD previously conducted in fast- and slow-growing chickens (Gallus gallus domesticus, n = 49, plus controls), in order to study the enantiomer specific accumulation and depuration of α-HBCDD in various tissues. Regarding abdominal adipose tissue, muscle and liver, the average enantiomeric fractions of α-HBCDD (EFα) for continuously exposed groups ranged between 0...
April 10, 2017: Chemosphere
https://www.readbyqxmd.com/read/28411227/fate-and-persistence-of-a-pathogenic-ndm-1-positive-escherichia-coli-strain-in-anaerobic-and-aerobic-sludge-microcosms
#12
David Mantilla-Calderon, Pei-Ying Hong
The presence of emerging biological pollutants in treated wastewater effluents has gained attention due to increased interest in water reuse. To evaluate the effectiveness of the removal of such contaminants by the conventional wastewater treatment process, the fate and decay kinetics of NDM-1-positive Escherichia coli strain PI7 and its plasmid-encoded antibiotic resistance genes (ARGs) were assessed in microcosms of anaerobic and aerobic sludge. Results showed that E. coli PI7 decayed at a significantly slower rate under anaerobic conditions...
April 14, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28411221/an-extracellular-cell-attached-pullulanase-confers-branched-%C3%AE-glucan-utilization-in-human-gut-lactobacillus-acidophilus
#13
Marie S Møller, Yong Jun Goh, Kasper Bøwig Rasmussen, Wojciech Cypryk, Hasan Ufuk Celebioglu, Todd R Klaenhammer, Birte Svensson, Maher Abou Hachem
Of the few predicted extracellular glycan-active enzymes, glycoside hydrolase family 13 subfamily 14 (GH13_14) pullulanases are the most common in human gut lactobacilli. These enzymes share a unique modular organization, not observed in other bacteria, featuring a catalytic module, two starch binding modules, a domain of unknown function, and a C-terminal surface layer association protein (SLAP) domain. Here we explore the specificity of a representative of this group of pullulanases, LaPul13_14 and its role in branched α-glucans metabolism in the well characterized Lactobacillus acidophilus NCFM that is widely used as a probiotic...
April 14, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28410433/simple-biochemical-networks-allow-accurate-sensing-of-multiple-ligands-with-a-single-receptor
#14
Vijay Singh, Ilya Nemenman
Cells use surface receptors to estimate concentrations of external ligands. Limits on the accuracy of such estimations have been well studied for pairs of ligand and receptor species. However, the environment typically contains many ligands, which can bind to the same receptors with different affinities, resulting in cross-talk. In traditional rate models, such cross-talk prevents accurate inference of concentrations of individual ligands. In contrast, here we show that knowing the precise timing sequence of stochastic binding and unbinding events allows one receptor to provide information about multiple ligands simultaneously and with a high accuracy...
April 14, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28409183/combination-of-il-10-and-il-2-induces-oligoclonal-human-cd4-t-cell-expansion-during-xenogeneic-and-allogeneic-gvhd-in-humanized-mice
#15
Sojan Abraham, Hua Guo, Jang-Gi Choi, Chunting Ye, Midhun Ben Thomas, Nora Ortega, Alok Dwivedi, N Manjunath, Guohua Yi, Premlata Shankar
IL-10 is a crucial anti-inflammatory cytokine which can also exert a seemingly divergent immunostimulatory effects under certain conditions. We found high levels of the cytokine in a xenogeneic GVHD model where NOD-scid IL2rγcnull (NSG) mice were transplanted with human PBMCs in presence of IL-2. Presence of exogenous IL-10 altered the kinetics of IL-2 induced human T cell reconstitution in vivo, showing an initial delay, followed by rapid expansion. Further, compared to IL-2 alone, treatment with IL-2 in combination with IL-10 increased survival in most animals and completely protected ∼20% of mice from GVHD...
April 2017: Heliyon
https://www.readbyqxmd.com/read/28408827/photothermal-modulated-drug-delivery-and-magnetic-relaxation-based-on-collagen-poly-%C3%AE-glutamic-acid-hydrogel
#16
Sun-Hee Cho, Ahreum Kim, Woojung Shin, Min Beom Heo, Hyun Jong Noh, Kwan Soo Hong, Jee-Hyun Cho, Yong Taik Lim
Injectable and stimuli-responsive hydrogels have attracted attention in molecular imaging and drug delivery because encapsulated diagnostic or therapeutic components in the hydrogel can be used to image or change the microenvironment of the injection site by controlling various stimuli such as enzymes, temperature, pH, and photonic energy. In this study, we developed a novel injectable and photoresponsive composite hydrogel composed of anticancer drugs, imaging contrast agents, bio-derived collagen, and multifaceted anionic polypeptide, poly (γ-glutamic acid) (γ-PGA)...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28408432/1-n-6-%C3%AE-hydroxypropanoadenine-the-acrolein-adduct-to-adenine-is-a-substrate-for-alkb-dioxygenase
#17
Małgorzata Dylewska, Jarosław Tomasz Kuśmierek, Tomasz Pilzys, Jarosław Poznański, Agnieszka Monika Maciejewska
1,N(6)-α-hydroxypropanoadenine (HPA) is an exocyclic DNA adduct of acrolein - an environmental pollutant and endocellular oxidative stress product. E. coli AlkB dioxygenase belongs to the superfamily of α-ketoglutarate (αKG)- and iron-dependent dioxygenases which remove alkyl lesions from bases via an oxidative mechanism, thereby restoring native DNA structure. Here, we provide in vivo and in vitro evidence that HPA is mutagenic and is effectively repaired by AlkB dioxygenase. HPA generated in plasmid DNA caused A→C and A→T transversions and, less frequently, A→G transitions...
April 13, 2017: Biochemical Journal
https://www.readbyqxmd.com/read/28407073/uptake-sequestration-and-tolerance-of-cadmium-at-cellular-levels-in-the-hyperaccumulator-plant-species-sedum-alfredii
#18
Shengke Tian, Ruohan Xie, Haixin Wang, Yan Hu, Dandi Hou, Xingcheng Liao, Patrick H Brown, Hongxia Yang, Xianyong Lin, John M Labavitch, Lingli Lu
Sedum alfredii is one of a few plant species known to hyperaccumulate cadmium (Cd). Uptake, localization, and tolerance of Cd at cellular levels in shoots were compared in hyperaccumulating (HE) and non-hyperaccumulating (NHE) ecotypes of Sedum alfredii. X-ray fluorescence images of Cd in stems and leaves showed only a slight Cd signal restricted within vascular bundles in the NHEs, while enhanced localization of Cd, with significant tissue- and age-dependent variations, was detected in HEs. In contrast to the vascular-enriched Cd in young stems, parenchyma cells in leaf mesophyll, stem pith and cortex tissues served as terminal storage sites for Cd sequestration in HEs...
April 12, 2017: Journal of Experimental Botany
https://www.readbyqxmd.com/read/28403478/non-animal-approaches-for-toxicokinetics-in-risk-evaluations-of-food-chemicals
#19
Ans Punt, Ad A C M Peijnenburg, Ron L A P Hoogenboom, Hans Bouwmeester
The objective of the present work was to review the availability and predictive value of non-animal toxicokinetic approaches and to evaluate their current use in European risk evaluations of food contaminants, additives and food contact materials, as well as pesticides and medicines. Results revealed little use of quantitative animal or human kinetic data in risk evaluations of food chemicals, compared with pesticides and medicines. Risk evaluations of medicines provided sufficient in vivo kinetic data from different species to evaluate the predictive value of animal kinetic data for humans...
April 12, 2017: ALTEX
https://www.readbyqxmd.com/read/28401144/insights-into-the-activity-change-of-spore-photoproduct-lyase-induced-by-mutations-at-a-peripheral-glycine-residue
#20
Linlin Yang, Lei Li
UV radiation triggers the formation of 5-thyminyl-5,6-dihydrothymine, i.e., the spore photoproduct (SP), in the genomic DNA of bacterial endospores. These SPs, if not repaired in time, may lead to genome instability and cell death. SP is mainly repaired by spore photoproduct lyase (SPL) during spore outgrowth via an unprecedented protein-harbored radical transfer pathway that is composed of at least a cysteine and two tyrosine residues. This mechanism is consistent with the recently solved SPL structure that shows all three residues are located in proximity and thus able to participate in the radical transfer process during the enzyme catalysis...
2017: Frontiers in Chemistry
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