bluuebunny/crossref_metadata_2025_split huggingface dataset:
Network-based genetic investigation of virulence-associated phenotypes in methicillin-resistant Staphylococcus aureus
Authors: Kim Chan Yeong , Lee Muyoung , Lee Keehoon , Yoon Sang Sun , Lee Insuk 
Published: July 2018

AbstractStaphylococcus aureus is a gram-positive bacterium that causes a wide range of infections. Recently, the spread of methicillin-resistant S. aureus (MRSA) strains has seriously reduced antibiotic treatment options. Anti-virulence strategies, the objective of which is to target the virulence instead of the viability of the pathogen, have become widely accepted as a means of avoiding the emergence of new antibiotic-resistant strains. To increase the number of anti-virulence therapeutic options, it is necessary to identify as many novel virulence-associated genes as possible in MRSA. Co-functional networks have proved useful for mapping gene-to-phenotype associations in various organisms. Herein, we present StaphNet (www.inetbio.org/staphnet), a genome-scale co-functional network for an MRSA strain, S. aureus subsp. USA300_FPR3757. StaphNet, which was constructed by the integration of seven distinct types of genomics data within a Bayesian statistics framework, covers approximately 94% of the coding genome with a high degree of accuracy. We implemented a companion web server for network-based gene prioritization of the phenotypes of 31 different S. aureus strains. We demonstrated that StaphNet can effectively identify genes for virulence-associated phenotypes in MRSA. These results suggest that StaphNet can facilitate target discovery for the development of anti-virulence drugs to treat MRSA infection.
Exosome-associated Shiga toxin 2 is released from cells and causes severe toxicity in mice
Authors: Watanabe-Takahashi Miho , Yamasaki Shinji , Murata Masayuki , Kano Fumi , Motoyama Jun , Yamate Jyoji , Omi Jumpei , Sato Waka , Ukai Hirofumi , Shimasaki Kentaro , Ikegawa Masaya , Tamura-Nakano Miwa , Yanoshita Ryohei , Nishino Yuri , Miyazawa Atsuo , Natori Yasuhiro , Toyama-Sorimachi Noriko , Nishikawa Kiyotaka 
Published: July 2018

AbstractShiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli (EHEC), is classified into two subgroups, Stx1 and Stx2. Clinical data clearly indicate that Stx2 is associated with more severe toxicity than Stx1, but the molecular mechanism underlying this difference is not fully understood. Here, we found that after being incorporated into target cells, Stx2, can be transported by recycling endosomes, as well as via the regular retrograde transport pathway. However, transport via recycling endosome did not occur with Stx1. We also found that Stx2 is actively released from cells in a receptor-recognizing B-subunit dependent manner. Part of the released Stx2 is associated with microvesicles, including exosome markers (referred to as exo-Stx2), whose origin is in the multivesicular bodies that formed from late/recycling endosomes. Finally, intravenous administration of exo-Stx2 to mice causes more lethality and tissue damage, especially severe renal dysfunction and tubular epithelial cell damage, compared to a free form of Stx2. Thus, the formation of exo-Stx2 might contribute to the severity of Stx2 in vivo, suggesting new therapeutic strategies against EHEC infections.
Molecular identification and characterization of rhodaneses from the insect herbivore Pieris rapae
Authors: Steiner Anna-Maria , Busching Christine , Vogel Heiko , Wittstock Ute 
Published: July 2018

AbstractThe association of cabbage white butterflies (Pieris spec., Lepidoptera: Pieridae) with their glucosinolate-containing host plants represents a well-investigated example of the sequential evolution of plant defenses and insect herbivore counteradaptations. The defensive potential of glucosinolates, a group of amino acid-derived thioglucosides present in plants of the Brassicales order, arises mainly from their rapid breakdown upon tissue disruption resulting in formation of toxic isothiocyanates. Larvae of P. rapae are able to feed exclusively on glucosinolate-containing plants due to expression of a nitrile-specifier protein in their gut which redirects glucosinolate breakdown to the formation of nitriles. The release of equimolar amounts of cyanide upon further metabolism of the benzylglucosinolate-derived nitrile suggests that the larvae are also equipped with efficient means of cyanide detoxification such as β-cyanoalanine synthases or rhodaneses. While insect β-cyanoalanine synthases have recently been identified at the molecular level, no sequence information was available of characterized insect rhodaneses. Here, we identify and characterize two single-domain rhodaneses from P. rapae, PrTST1 and PrTST2. The enzymes differ in their kinetic properties, predicted subcellular localization and expression in P. rapae indicating different physiological roles. Phylogenetic analysis together with putative lepidopteran rhodanese sequences indicates an expansion of the rhodanese family in Pieridae.
Dry Spin Graphene Oxide Fibers: Mechanical/Electrical Properties and Microstructure Evolution
Authors: Feng Lichao , Chang Ying , Zhong Jing , Jia De-Chang 
Published: July 2018

AbstractDry-spinning method is extensively employed in fiber industry, comparing to the counter-part of wet-spinning process, it has advantages of environmentally friendly, high yield rate and no need for purification. Here, we report the synthesis of graphene oxide (GO) fibers via dry spinning GO inks with extremely high concentrations. The proper rheology properties of such GO inks allow us to dry spin GO fiber directly. Various dry spinning conditions are investigated, and the relationship between mechanical performance and micro-structure of the obtained GO fiber are established. We found that the existence of larger GO liquid crystal domains does not necessarily result to higher mechanical properties, and it is because those large GO liquid crystal domains evolve into thick GO films during drying process and thus prevent the intimate compaction of the whole GOF and leave behind gaps. This is detrimental for the mechanical properties, and thus the dry spin GOF are much weaker than that of wet spin ones. Importantly, Barus effects, that generally arise during the melt spinning of polymers, were not observed, indicating that caution must be taken when classical polymer rheology theories are applied to investigate the dynamic behaviors of GO solution.
Differences in biochemical markers between Heart-transplanted and Left Ventricular Assist Device implanted patients, during cardiac rehabilitation
Authors: Racca Vittorio , Castiglioni Paolo , Panzarino Claudia , Saresella Marina , Marventano Ivana , Verde Alessandro , Oliva Fabrizio , Ferratini Maurizio 
Published: July 2018

AbstractHeart transplant (HTx) and left ventricular assist device (LVAD) implant are the best options for symptomatic end stage heart failure, but LVAD patients show lower rehabilitative outcome than HTx patients. To investigate the causes, we compared biomarkers levels and their association with rehabilitative outcome in 51 HTx and in 46 LVAD patients entering the same cardiac rehabilitation program. In both groups, routine biomarkers were measured at start (T1) and end (T2) of cardiac rehabilitation while homocysteine, leptine and IGF-1 were measured at T1 only. HTx patients had lower lymphocyte, platelets, glucose, total proteins and albumin at T1; differences with LVAD patients vanished during rehabilitation when new cases of diabetes were observed in HTx. By contrast, total cholesterol, LDL and HDL fractions, leptin and IGF-1 were higher in HTx patients. The increase from T1 to T2 in six-minute walking test distance, measure of functional rehabilitation outcome, was positively associated with homocysteine and IGF-1 levels in HTx patients. In conclusion, during rehabilitation care should be paid to the early occurrence of dyslipidemia and hyperglycemia in HTx patients, which also require a proper protein dietary support. IGF-1, dangerously low in LVAD patients, might contribute to their lower rehabilitative outcome.
LBT/ARGOS adaptive optics observations of z ∼ 2 lensed galaxies
Authors: Perna M. , Curti M. , Cresci G. , Mannucci F. , Rabien S. , Grillo C. , Belli S. , Bonaglia M. , Busoni L. , Contursi A. , Esposito S. , Georgiev I. , Lutz D. , Orban de Xivry G. , Zibetti S. , Gaessler W. , Mazzoni T. , Borelli J. , Rosensteiner M. , Ziegleder J. , Buschkamp P. , Rahmer G. , Kulas M. , Peter D. , Raab W. , Deysenroth M. , Gemperlein H. 
Published: July 2018

Aims. Gravitationally lensed systems allow a detailed view of galaxies at high redshift. High spatial- and spectral-resolution measurements of arc-like structures can offer unique constraints on the physical and dynamical properties of high-z systems.
Methods. We present near-infrared spectra centred on the gravitational arcs of six known z ∼ 2 lensed star-forming galaxies of stellar masses of 109−11 M⊙ and star formation rate (SFR) in the range between 10 and 400 M⊙ yr−1. Ground layer adaptive optics (AO)-assisted observations are obtained at the Large Binocular Telescope (LBT) with the LUCI spectrographs during the commissioning of the ARGOS facility. We used MOS masks with curved slits to follow the extended arched structures and study the diagnostic emission lines. LBT observations are used to demonstrate the spectroscopic capabilities of ARGOS.
Results. Combining spatially resolved kinematic properties across the arc-like morphologies, emission line diagnostics and archival information, we distinguish between merging and rotationally supported systems, and reveal the possible presence of ejected gas. For galaxies that have evidence for outflows, we derive outflow energetics and mass-loading factors compatible with those observed for stellar winds in local and high-z galaxies. We also use flux ratio diagnostics to derive gas-phase metallicities. The low signal-to-noise ratio in the faint Hβ and nitrogen lines allows us to derive an upper limit of ≈0.15 dex for the spatial variations in metallicity along the slit for the lensed galaxy J1038.
Conclusions. Analysed near-infrared spectra presented here represent the first scientific demonstration of performing AO-assisted multi-object spectroscopy with narrow curved-shape slits. The increased angular and spectral resolution, combined with the binocular operation mode with the 8.4 m wide eyes of LBT, will allow the characterisation of kinematic and chemical properties of a large sample of galaxies at high-z in the near future.
W 50 and SS 433
Authors: Bowler Michael G. , Keppens Rony 
Published: July 2018

Context. The Galactic microquasar SS 433 launches oppositely directed jets at speeds approximately a quarter of the speed of light. These appear to have punched through and beyond the supposed supernova remnant shell W 50. The problems with this interpretation are: (i) the precessing jets have somehow been collimated before reaching the shell; (ii) without deceleration, only recently launched jets would have reached no further; and (iii) certain features in the lobes are moving slowly or are stationary.
Aims. Hydrodynamic computations have demonstrated that for at least one set of parameters describing the ambient medium, jets that diverge and precess are both decelerated and collimated; the conformation of W 50 could then have been sculpted by the jets of SS 433. However, the parameters adopted for density and pressure in these computations are not consistent with observations of jets at a few years old; nor do they represent conditions within a supernova remnant. Our aim is to investigate whether the computations already performed can be scaled to a realistic W 50.
Methods. We find simple and physically based scaling relations. The distance to collimation varies inversely with the square root of the pressure of the ambient medium and the speed with which the head of a collimated jet propagates scales with the square root of the temperature. We extrapolate the results of the hydrodynamic computations to lower densities and pressures.
Results. The jets of SS 433, launched into an ambient medium of pressure ~10−9 erg cm−3 and temperature ~108 K, within a supernova remnant, could be responsible for the characteristics of W 50. The precessing jets are collimated within ~10 pc and the head of the resulting cylindrical jet propagates slowly.
Conclusions. The problems of relating W 50 to SS 433 may now be solved.
Multiphoton imaging provides a superior optical biopsy to that of confocal laser endomicroscopy imaging for colorectal lesions
Authors: Yan Jun , Zheng Xiaoling , Liu Zhangyuanzhu , Liu Wenju , Lin Dajia , Chen Dexin , Li Kai , Jiang Wei , Li Zhiming , Zuo Ning , Chen Gang , Lu Jianping , Chen Jianxin , Li Guoxin , Xu Chris , Zhuo Shuangmu 
Published: July 2018

Abstract
Background Confocal laser endomicroscopy (CLE) requires fluorescence agents, the use of which leads to blurred images and low diagnostic accuracy owing to fluorescein leakage. We aimed to explore whether multiphoton imaging (MPI) could serve as a better method of optical biopsy.
Methods First, a pilot study was performed to set up the optical diagnostic criteria of MPI for benign or malignant colorectal lesions in 30 patients. Then, a blinded study was conducted to compare the sensitivity, specificity, and accuracy of MPI versus CLE imaging in 79 patients.
Results In the pilot study, MPI revealed regular tissue architecture and cell morphology in the normal tissue, and irregular tubular structures, and cellular and nuclear pleomorphism in the abnormal tissue. In the blinded study, compared with CLE imaging, MPI significantly improved the diagnostic sensitivity, specificity, and accuracy of the optical biopsy (89.74 % vs. 61.54 %, P = 0.008; 92.5 % vs. 67.5 %, P = 0.009; and 91.14 % vs. 64.56 %, P = 0.001, respectively).
Conclusions MPI can provide a superior optical biopsy to that of CLE imaging for colorectal lesions.
A Sensitive Bioimmunoassay for Thrombin-cleaved Two-chain Urokinase-type Plasminogen Activator in Human Body Fluids
Authors: Braat Ellen A M , Nauland Ume , Dooijewaard Gerard , Rijken Dingeman C 
Published: July 2018

SummaryThrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a two-chain form (tcu-PA/T), which is virtually inactive in plasminogen activator assays. Little is known about the physiological importance of tcu-PA/T. To examine the occurrence of tcu-PA/T in vivo, we developed a sensitive and specific bioimmunoassay (BIA) for the assessment of tcu-PA/T in human body fluids. In this BIA, urokinase antigen was immuno-immobilized in microtiter plates and treated with cathepsin C, a specific activator of tcu-PA/T, after which plasminogen activator activity was measured. The occurrence of tcu-PA/T was examined in the plasma of 27 healthy individuals and of 17 sepsis patients, and in the synovial fluid of 16 rheumatoid arthritis patients. In addition, the concentration of urokinase antigen and scu-PA were measured in all three groups. In the plasma of the healthy individuals no measurable amounts of tcu-PA/T could be found (< detection limit of 0.2 ng/ml). In the plasma of almost all sepsis patients tcu-PA/T could be detected (median value 0.4 ng/ml). The amount of tcu-PA/T was 12% of the amount of scu-PA and accounted for about 9% of urokinase antigen. In the synovial fluid of all rheumatoid arthritis patients tcu-PA/T could be measured (median value 5.4 ng/ml) at a concentration which was twofold higher than the concentration found for scu-PA. In this group tcu-PA/T contributed to about 47% of the urokinase antigen. From these data we conclude that inactivation of scu-PA by thrombin can take place in vivo under pathological conditions which involve the production of large amounts of thrombin. This way thrombin may regulate fibrinolysis and extracellular proteolysis. The BIA for tcu-PA/T can be of use for further research on the physiological role of tcu-PA/T.
Limiting Systemic Plasminogenolysis Reduces the Bleeding Potential for Tissue-type Plasminogen Activators but not for Streptokinase
Authors: Roger Thomas G , Thibodeaux Harold , Errett Carol J , Badillio Julie M , Wu Daisy T , Refino Canio J , Keyt Bruce A , Bennett William F 
Published: July 2018

SummaryClinical experience suggests that thrombolytic-induced bleeding is associated with systemic activation of the thrombolytic system. Using fibrin specific variants of tissue-type plasminogen activator (t-PA) and making use of the apparent fibrin specificity of streptokinase (SK) in the rabbit we tested the hypothesis that minimizing systemic plasmin production and fibrinogenolysis will decrease hemorrhages in models of peripheral bleeding and embolic stroke. t-PA consumed 51% of the available fibrinogen; caused cerebral bleeds and increased peripheral bleeding time. Fibrin-specific variants of t-PA depleted less than 20% of the fibrinogen and did not cause peripheral or cerebral bleeding. However, an equipotent dose of SK converted only 12% of the available fibrinogen but increased bleeding time and caused hemorrhagic conversion in 75% of embolic stroke model animals treated. The data suggest that bleeding associated with tissue-type plasminogen activators is linked to systemic plasmin generation and subsequent fibrinogenolysis. This hypothesis does not explain the mechanism(s) of SK-in-duced bleeding.
Characterisation of Type 2N von Willebrand Disease Using Phenotypic and Molecular Techniques
Authors: Nesbitt I M , Goodeve A C , Guilliatt A M , Makris M , Preston F E , Peake I R 
Published: July 2018

Summaryvon Willebrand factor (vWF) is a multimeric glycoprotein found in plasma non covalently linked to factor VIII (FVIII). Type 2N von Willebrand disease (vWD) is caused by a mutation in the vWF gene that results in vWF with a normal multimeric pattern, but with reduced binding to FVIII.We have utilised methods for the phenotypic and genotypic detection of type 2N vWD. The binding of FVIII to vWF in 69 patients, 36 with type 1 vWD, 32 with mild haemophilia A and one possible haemophilia A carrier with low FVIII levels was studied. Of these, six were found to have reduced binding (five type 1 vWD, one possible haemophilia A carrier), DNA was extracted from these patients and exons 18-23 of the vWF gene encoding the FVIII binding region of vWF were analysed. After direct sequencing and chemical cleavage mismatch detection, a Thr28Met mutation was detected in two unrelated individuals, one of whom appears to be a compound heterozygote for the mutation and a null allele. No mutations were found in the region of the vWF gene encoding the FVIII binding region of vWF in the other four patients
In Vivo Studies of Activated Porcine Factor VIII
Authors: Littlewood Janet D , Bevan Sally A , Kemball-Cook Geoffrey , Barrowcliffe Trevor W 
Published: July 2018

SummaryThe haemostatic effectiveness of activated FVIII was compared to that of non-activated FVIII in a cross-over study in a canine model of haemophilia. Activation of FVIII in porcine concentrate was achieved by the addition of 3 × 10−5 IU thrombin per ml of concentrate, which gave consistent increases in 1-stage FVIII activity of 13- to 14-fold and slow decay. The haemostatic effect was monitored by measurements of the cuticle bleeding time 10 and 45 min after infusion and there were no consistent differences between the activated and non-activated concentrates. One-stage factor VIII assays on plasmas 5 min after infusion showed identical mean values for activated and non-activated concentrates, indicating that most of the higher activity observed in vitro had disappeared rapidly from the circulation.These results suggest that controlled activation of FVIII by thrombin, which increases its activity in 1-stage assays, is unlikely to be of therapeutic benefit. For therapeutic concentrates which may contain small amounts of activated FVIII, the 1-stage assay may be an unreliable guide to their therapeutic effect.
Functional Significance of NH2- and COOH-Terminal Regions of Staphylokinase in Plasminogen Activation
Authors: Gase Ariane , Hartmann Manfred , Gührs Karl-Heinz , Röcker Anja , Collen Désiré , Behnke Detlev , Schlott Bernhard 
Published: July 2018

SummaryStructure/function relationships in the activation of plasminogen with staphylokinase were studied using mutants of recombinant staphylokinase (Sak42D). Deletion of up to 10 NH2-terminal amino acids (Sak42DΔN10) did not affect plasminogen activation, but removal of 11 amino acids completely abolished the ability to activate plasminogen. Elimination of potential plasmin cleavage sites in the NH2-terminal region yielding mutants Sak42D(K8H,K10H,KllH) and Sak42D(K6H,K8H,KllH) did not alter the rate of the exposure of a proteolytically active site (amidolytic activity) in equimolar mixtures with plasminogen, but destroyed the plasminogen activator properties of these muteins. Deleting two residues following the preferred processing site at position 10 (Sak42Δ(K11,G12)) resulted in a mutein also inactive in plasminogen activation. Removal of the COOH-terminal Lys136, yielding Sak42DΔCl, or of Lysl35 and Lysl36 in Sak42DΔC2 resulted in proteins with strongly reduced plasminogen activation capacity. In contrast, substitution of Lys135 and Lys136 with Ala in Sak42D(K135A,K136A) did not affect activation. Cyanogen bromide cleavage of Sak42D(M26L,E61M,D82E) produced a 61 amino acid NH2-terminal and a 65 amino acid COOH-terminal fragment which did not activate plasminogen, but bound to plasminogen with affinity constants Ka of 4.0 × 105 M−1 and 1.4 × 107 M−1, respectively (as compared to a Ka of 1.1 × 108 M−1 for Sak42D).These results indicate that Lysl 1 and the COOH-terminal region of staphylokinase play a key role in the activation of plasminogen.
Thrombin-activated Human Platelets Release two NAP-2 Variants that Stimulate Polymorphonuclear Leukocytes
Authors: Piccardoni Paola , Evangelista Virgilio , Piccoli Antonio , de Gaetano Giovanni , Walz Alfred , Cerletti Chiara 
Published: July 2018

SummaryThrombin-activated human platelets release substance(s) of a prote-ic nature which induce an increase in the intracellular calcium concentration in polymorphonuclear leukocytes (PMN). Aim of this study was to characterize the platelet released product(s) responsible for PMN stimulation.PMN-stimulating activity was isolated from platelet supernatant by FPLC and HPLC. The N-terminal sequence analysis revealed that the purified fractions consisted in 90% of a peptide of 73 amino acids and in 10% of a peptide of 74 amino acids; both are truncated forms of the connective tissue-activating peptide III (CTAP-III), a platelet a-granule product, and have 3 and 4 additional amino acids at the N-terminus compared with the neutrophil-activating peptide 2 (NAP-2): Asp-Leu-Tyr and Ser-Asp-Leu-Tyr, respectively. Treatment of platelet supernatant (previously depleted of PMN-activating nucleotides) with Affi-gel heparin resulted in the disappearance of PMN-stimulating effects, suggesting that NAP-2 variants, which are heparin-binding proteins, account for ATP-independent PMN-stimulating activity of the supernatant. Cross-desensitization between rNAP-2 and the platelet supernatant and inhibition by the anti-NAP-2 antibody are in agreement with this conclusion. Although NAP-2 and its variants are reportedly generated from the inactive precursors, CTAP-III and platelet basic protein, through a proteolytic cleavage, NAP-2 variants were not generated in our system by proteases deriving from platelets or contaminating leukocytes. Indeed, treatment of intact platelet suspensions with different protease inhibitors failed to modify the calcium stimulating activity of the resulting supernatants. In conclusion, thrombin-activated platelets release NAP-2 variants which are not generated outside the platelets by proteolytic processing but are released in an active form. This finding enhances our understanding of platelet-PMN interaction in thrombosis and inflammation.