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https://www.readbyqxmd.com/read/27921033/new-tools-to-study-contact-activation
#1
Steffen Rosén
The recent availability of a sensitive chromogenic method approach for determination of FXIa activity has been explored for designing sensitive methods for FXIIa and kallikrein, both using FXa formation as the read-out. For both enzymes the assay range 1-10 nmol/L provides a resolution of about 0.8 absorbance units with a total assay time of about 20 min. For studies on activation kinetics, subsampling and extensive dilution can be performed in MES-bovine serum albumin (BSA) buffer pH 5.7 for quenching of enzyme activity and with ensuing determination of FXa generation in a chromogenic FXIa method...
2016: Frontiers in Medicine
https://www.readbyqxmd.com/read/27919873/managing-transitions-from-oral-factor-xa-inhibitors-to-unfractionated-heparin-infusions
#2
Andrew C Faust, Dave Kanyer, Ann K Wittkowsky
PURPOSE: Published evidence regarding the effects of oral factor Xa inhibitors on anticoagulation monitoring tests is reviewed with a focus on monitoring concerns that can arise during transitions to i.v. heparin therapy. SUMMARY: Assays that measure inhibition of factor Xa activity (i.e., anti-Xa assays) are widely used in U.S. institutions to monitor i.v. heparin therapy and, in some cases, for monitoring other types of anticoagulation therapy. Clinicians have raised concerns that the use of anti-Xa assays to monitor heparin levels in hospitalized patients who must be transitioned from oral factor Xa inhibitor therapy to i...
December 15, 2016: American Journal of Health-system Pharmacy: AJHP
https://www.readbyqxmd.com/read/27911408/defining-substrate-specificities-for-lipase-and-phospholipase-candidates
#3
Diana X Sahonero-Canavesi, Maritza Zavaleta-Pastor, Lourdes Martínez-Aguilar, Isabel M López-Lara, Otto Geiger
Microorganisms produce a wide spectrum of (phospho)lipases that are secreted in order to make external substrates available for the organism. Alternatively, other (phospho)lipases may be physically associated with the producing organism causing a turnover of intrinsic lipids and frequently giving rise to a remodeling of the cellular membranes. Although potential (phospho)lipases can be predicted with a number of algorithms when the gene/protein sequence is available, experimental proof of the enzyme activities, substrate specificities, and potential physiological functions has frequently not been obtained...
November 23, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27911360/development-of-a-more-sensitive-and-specific-chromogenic-agar-medium-for-the-detection-of-vibrio-parahaemolyticus-and-other-vibrio-species
#4
Marie Yeung, Trevor Thorsen
Foodborne infections in the US caused by Vibrio species have shown an upward trend. In the genus Vibrio, V. parahaemolyticus is responsible for the majority of Vibrio-associated infections. Thus, accurate differentiation among Vibrio spp. and detection of V. parahaemolyticus is critically important to ensure the safety of our food supply. Although molecular techniques are increasingly common, culture-depending methods are still routinely done and they are considered standard methods in certain circumstances...
November 8, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27909693/unfractionated-and-low-molecular-weight-heparin-and-the-phosphodiesterase-inhibitors-ibmx-and-cilostazol-block-ex-vivo-equid-herpesvirus-type-1-induced-platelet-activation
#5
Tracy Stokol, Priscila B D Serpa, Muhammad N Zahid, Marjory B Brooks
Equid herpes virus type-1 (EHV-1) is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation...
2016: Frontiers in Veterinary Science
https://www.readbyqxmd.com/read/27898513/inhibition-of-plasmin-generation-in-plasma-by-heparin-low-molecular-weight-heparin-and-a-covalent-antithrombin-heparin-complex
#6
Gabriela M T Chang, Helen M Atkinson, Leslie R Berry, Anthony K C Chan
The clinical limitations of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) led to the development of an antithrombin-heparin covalent complex (ATH), which displays superior anticoagulant abilities compared with UFH. A recent study investigating its interaction with fibrinolysis showed that ATH inhibited free and fibrin bound plasmin and decreased plasmin generation on fibrin clots. These studies were conducted using purified components and did not elucidate the interaction of ATH with plasmin in the presence of its natural inhibitors α2-antiplasmin (α2-AP) and α2-macroglobulin (α2-M)...
November 24, 2016: Blood Coagulation & Fibrinolysis: An International Journal in Haemostasis and Thrombosis
https://www.readbyqxmd.com/read/27896356/vapochromic-features-of-new-luminogens-based-on-julolidine-containing-styrene-copolymers
#7
Giuseppe Iasilli, Fabio Martini, Pierpaolo Minei, Giacomo Ruggeri, Andrea Pucci
We report on vapochromic films suitable for detecting volatile organic compounds (VOCs), based on new polystyrene copolymers containing julolidine fluorescent molecular rotors (JCAEM). Poly(styrene-co-hydroxyethylmethacrylate) copolymers functionalized with cyanovinyl-julolidine moieties of different compositions were prepared, (P(STY-co-JCAEM)(m) with m = 0.06-0.61). The sensing performance of the spin-coated copolymer films demonstrated significant vapochromism when exposed to VOCs characterized by high vapour pressure and a favourable interaction with the polymer matrix, such as Et2O and CH2Cl2...
November 29, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27894360/the-relationship-of-endotoxaemia-to-peripheral-and-central-nervous-system-inflammatory-responses-in-human-african-trypanosomiasis
#8
Lorna Maclean, Eltayb A Aboubaker, Peter G E Kennedy, Jeremy M Sternberg
Endotoxaemia has been described in cases of Human African trypanosomiasis (HAT), but it is unclear if this phenomenon influences inflammatory pathology either in the periphery or central nervous system (CNS). We studied endotoxin concentrations in the plasma and cerebrospinal fluid (CSF) of Trypanosoma brucei rhodesiense patients using the chromogenic Limulus Amoebocyte lysate assay. The relationship of endotoxin concentration to the presentation of gross signs of inflammation and the inflammatory/counter-inflammatory cytokine profile of the relevant compartments were analysed...
November 29, 2016: Parasitology
https://www.readbyqxmd.com/read/27891543/dynamic-neighbouring-participation-of-nitrogen-lone-pairs-on-the-chromogenic-behaviour-of-trans-bis-salicylaldiminato-pt-ii-coordination-platforms
#9
Takumi Hashimoto, Kanako Fukumoto, Ngoc Ha-Thu Le, Tatsuya Matsuoka, Soichiro Kawamorita, Naruyoshi Komiya, Takeshi Naota
The participation of neighbouring nitrogen lone pairs in the chromogenic control of trans-bis(salicylaldiminato)Pt(ii) platforms was examined, using newly designed Pt analogues bearing salicylaldehyde hydrazone ligands. A series of non-vaulted and vaulted Pt complexes (1-5) with salicylaldehyde hydrazones as trans-coordinated bidentate ligands were synthesized and characterized with regard to the chromogenic behaviour of the trans-bis(salicylaldiminato)Pt(ii) coordination platforms. X-ray diffraction and 2D NMR data demonstrated that, in the case of the non-vaulted N-monomethyl complexes 1, there was significant participation of neighbouring N(2) lone pairs in the d-π conjugation of the trans-bis(salicylaldiminato)Pt(ii) platforms owing to conformational fixation arising from intramolecular hydrogen bonding...
November 28, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/27887027/expansion-of-the-substrate-range-of-the-gentisate-1-2-dioxygenase-from-corynebacterium-glutamicum-for-the-conversion-of-monohydroxylated-benzoates
#10
Erik Eppinger, Andreas Stolz
The gentisate 1,2-dioxygenases (GDOs) from Corynebacterium glutamicum and various other organisms oxidatively cleave the aromatic nucleus of gentisate (2,5-dihydroxybenzoate), but are not able to convert salicylate (2-hydroxybenzoate). In contrast, the α-proteobacterium Pseudaminobacter salicylatoxidans synthesises an enzyme ('salicylate dioxygenase', SDO) which cleaves gentisate, but also (substituted) salicylate(s). Sequence comparisons showed that the SDO belongs to a group of GDOs mainly originating from Gram-positive bacteria which also include the GDO from C...
November 24, 2016: Protein Engineering, Design & Selection: PEDS
https://www.readbyqxmd.com/read/27886764/sensitive-and-selective-colorimetric-assay-of-alkaline-phosphatase-activity-with-cu-ii-phenanthroline-complex
#11
Qiong Hu, Minhui He, Yaqi Mei, Wenjie Feng, Su Jing, Jinming Kong, Xueji Zhang
Alkaline phosphatase (ALP) plays a vital role in dephosphorylation- and phosphorylation-related cellular regulation and signaling processes. Accordingly, the development of efficient methods for ALP activity assay is of significant importance in clinical diagnosis. In this work, a simple and practical method is reported for the first time for the sensitive and selective colorimetric assay of ALP activity by exploiting a water-soluble Cu(II)-phenanthroline complex as the probe, on the basis of the distinctive metal-to-ligand charge-transfer (MLCT) properties...
January 15, 2017: Talanta
https://www.readbyqxmd.com/read/27878595/cell-type-specific-expression-of-nfix-in-the-developing-and-adult-cerebellum
#12
James Fraser, Alexandra Essebier, Richard M Gronostajski, Mikael Boden, Brandon J Wainwright, Tracey J Harvey, Michael Piper
Transcription factors from the nuclear factor one (NFI) family have been shown to play a central role in regulating neural progenitor cell differentiation within the embryonic and post-natal brain. NFIA and NFIB, for instance, promote the differentiation and functional maturation of granule neurons within the cerebellum. Mice lacking Nfix exhibit delays in the development of neuronal and glial lineages within the cerebellum, but the cell-type-specific expression of this transcription factor remains undefined...
November 23, 2016: Brain Structure & Function
https://www.readbyqxmd.com/read/27878149/synthesis-of-precipitating-chromogenic-fluorogenic-%C3%AE-glucosidase-%C3%AE-galactosidase-substrates-by-a-new-method-and-their-application-in-the-visual-detection-of-foodborne-pathogenic-bacteria
#13
Xianhu Wei, Qingping Wu, Jumei Zhang, Youxiong Zhang, Weipeng Guo, Moutong Chen, Qihui Gu, Zhihe Cai, Mianfei Lu
We developed a new efficient method for the synthesis of important indoxyl glycoside substrates for β-glucosidase and β-galactosidase by using 1-acetylindol-3-ones as intermediates. This method was used to synthesise novel precipitating fluorogenic substrates for β-glucosidase based on 2-(benzothiazol-2'-yl)-phenols. We also assessed the application of these substrates in the detection of foodborne pathogenic bacteria.
November 23, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27876785/characterization-of-the-annonaceous-acetogenin-annonacinone-a-natural-product-inhibitor-of-plasminogen-activator-inhibitor-1
#14
Stéphane Pautus, Mouad Alami, Fréderic Adam, Guillaume Bernadat, Daniel A Lawrence, Allan De Carvalho, Gilles Ferry, Alain Rupin, Abdallah Hamze, Pierre Champy, Natacha Bonneau, Philippe Gloanec, Jean-Louis Peglion, Jean-Daniel Brion, Elsa P Bianchini, Delphine Borgel
Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of the tissue type and urokinase type plasminogen activators. High levels of PAI-1 are correlated with an increased risk of thrombotic events and several other pathologies. Despite several compounds with in vitro activity being developed, none of them are currently in clinical use. In this study, we evaluated a novel PAI-1 inhibitor, annonacinone, a natural product from the Annonaceous acetogenins group. Annonacinone was identified in a chromogenic screening assay and was more potent than tiplaxtinin...
November 23, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27876270/a-new-manufacturing-process-to-remove-thrombogenic-factors-ii-vii-ix-x-and-xi-from-intravenous-immunoglobulin-gamma-preparations
#15
Dong Hwarn Park, Gil Bu Kang, Dae Eun Kang, Jeung Woon Hong, Min Gyu Lee, Ki Yong Kim, Jeung Whan Han
Coagulation factors (II, VII, IX, X, and particularly XIa) remaining in high concentrations in intravenous immunoglobulin (IVIG) preparations can form thrombi, causing thromboembolic events, and in serious cases, result in death. Therefore, manufacturers of biological products must investigate the ability of their production processes to remove procoagulant activities. Previously, we were able to remove coagulation factors II, VII, IX, and X from our IVIG preparation through ethanol precipitation, but factor XIa, which plays an important role in thrombosis, remained in the intermediate products...
November 18, 2016: Biologicals: Journal of the International Association of Biological Standardization
https://www.readbyqxmd.com/read/27873028/mcr-modern-colistin-resistance
#16
REVIEW
I Caniaux, A van Belkum, G Zambardi, L Poirel, M F Gros
Recently, plasmid-mediated and, therefore, transferable bacterial polymyxin resistance was discovered in strains from both humans and animals. Such a trait may widely spread geographically, while simultaneously crossing microbial species barriers. This may ultimately render the "last resort" polymyxin antibiotics therapeutically useless. Colistin is currently used to treat infections caused by Gram-negative carbapenemase producers and colistin resistance may lead to practical pan-antibiotic resistance. We here analyzed the medical and diagnostic consequences of (emerging) colistin resistance and propose pathways toward adequate diagnostics for timely detection of both asymptomatic carriage and infection...
November 21, 2016: European Journal of Clinical Microbiology & Infectious Diseases
https://www.readbyqxmd.com/read/27872722/production-of-monoclonal-antibody-against-recombinant-ns3-protein-of-bovine-viral-diarrhea-virus-nadl-strain
#17
Masood Reza Seyfi Abad Shapouri, Maryam Ekhtelat, Masood Ghorbanpoor Najaf Abadi, Mohsen Lotfi, Mohamad Rashno
This study was conducted to investigate the prevalence of subclinical mastitis caused by Staphylococcus spp. in ewes in West-Azerbaijan province of Iran. Molecular characterization of isolated Staphylococcus spp. from diseased ewes were performed using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) and DNA sequencing of glyceraldehyde-3-phosphate dehydrogenase (gap) gene. Also, antibiotic resistance of staphylococcal isolates against different antibiotics was investigated...
2016: Veterinary Research Forum
https://www.readbyqxmd.com/read/27871613/revisiting-catechol-derivatives-as-robust-chromogenic-hydrogen-donors-working-in-alkaline-media-for-peroxidase-mimetics
#18
Marcin Drozd, Mariusz Pietrzak, Jakub Pytlos, Elżbieta Malinowska
Colloidal noble metal-based nanoparticles are able to catalyze oxidation of chromogenic substrates by H2O2, similarly to peroxidases, even in basic media. However, lack of robust chromogens, which work in high pH impedes their real applications. Herein we demonstrate the applicability of selected catechol derivatives: bromopyrogallol red (BPR) and pyrogallol (PG) as chromogenic substrates for peroxidase-like activity assays, which are capable of working over wide range of pH, covering also basic values. Hyperbranched polyglycidol-stabilized gold nanoparticles (HBPG@AuNPs) were used as model enzyme mimetics...
December 15, 2016: Analytica Chimica Acta
https://www.readbyqxmd.com/read/27869794/covalently-deposited-dyes-a-new-chromogen-paradigm-that-facilitates-analysis-of-multiple-biomarkers-in-situ
#19
William A Day, Mark R Lefever, Robert L Ochs, Anne Pedata, Lauren J Behman, Julia Ashworth-Sharpe, Donald D Johnson, Eric J May, James G Grille, Esteban A Roberts, Jerry W Kosmeder, Larry E Morrison
Multiplexed analysis of multiple biomarkers in a tissue sample requires use of reporter dyes with specific spectral properties that enable discrimination of signals. Conventional chromogens with broad absorbance spectra, widely used in immunohistochemistry (IHC), offer limited utility for multiplexed detection. Many dyes with narrow absorbance spectra, eg rhodamines, fluoresceins, and cyanines, potentially useful for multiplexed detection are well-characterized; however, generation of a chromogenic reagent useful for IHC analysis has not been demonstrated...
November 21, 2016: Laboratory Investigation; a Journal of Technical Methods and Pathology
https://www.readbyqxmd.com/read/27869661/an-exploratory-investigation-of-endotoxin-levels-in-novice-long-distance-triathletes-and-the-effects-of-a-multi-strain-probiotic-prebiotic-antioxidant-intervention
#20
Justin D Roberts, Craig A Suckling, Georgia Y Peedle, Joseph A Murphy, Tony G Dawkins, Michael G Roberts
Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females) were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB⁴ANTI; 30 billion CFU·day(-1) containing 10 billion CFU·day(-1)Lactobacillus acidophilus CUL-60 (NCIMB 30157), 10 billion CFU·day(-1)Lactobacillus acidophillus CUL-21 (NCIMB 30156), 9...
November 17, 2016: Nutrients
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