bluuebunny/crossref_metadata_2025 huggingface dataset:
Visitors’ willingness to pay for snow leopard Panthera uncia conservation in the Annapurna Conservation Area, Nepal
Authors: Schutgens Maurice G. , Hanson Jonathan H. , Baral Nabin , Ale Som B.
Published: March 2018

The Vulnerable snow leopard Panthera uncia experiences persecution across its habitat in Central Asia, particularly from herders because of livestock losses. Given the popularity of snow leopards worldwide, transferring some of the value attributed by the international community to these predators may secure funds and support for their conservation. We administered contingent valuation surveys to 406 international visitors to the Annapurna Conservation Area, Nepal, between May and June 2014, to determine their willingness to pay a fee to support the implementation of a Snow Leopard Conservation Action Plan. Of the 49% of visitors who stated they would pay a snow leopard conservation fee in addition to the existing entry fee, the mean amount that they were willing to pay was USD 59 per trip. The logit regression model showed that the bid amount, the level of support for implementing the Action Plan, and the number of days spent in the Conservation Area were significant predictors of visitors’ willingness to pay. The main reasons stated by visitors for their willingness to pay were a desire to protect the environment and an affordable fee. A major reason for visitors’ unwillingness to pay was that the proposed conservation fee was too expensive for them. This study represents the first application of economic valuation to snow leopards, and is relevant to the conservation of threatened species in the Annapurna Conservation Area and elsewhere.
Interpersonal processes in paranoia: a systematic review
Authors: Meisel Susanne F. , Garety Philippa A. , Stahl Daniel , Valmaggia Lucia R.
Published: March 2018

Paranoid ideation is a core feature of psychosis, and models of paranoia have long proposed that it arises in the context of disturbances in the perception of the self. However, to develop targeted interventions, there is a benefit in clarifying further, which aspects of self-perception are implicated. Interpersonal sensitivity is a personality trait which has been associated with the risk of paranoid thinking in the general population. However, not all studies have found this link. We aimed to review the empirical literature assessing the association between interpersonal sensitivity and paranoia in both general population and clinical samples; and to explore if associations found differed depending on whether state or trait paranoia was assessed. The review followed PRISMA guidelines. Articles were identified through a literature search in OVID (PsychINFO, MEDLINE) and Web of Science up to December 2016. Fourteen studies with a total of 12 138 participants were included. All studies were of ‘fair’ or ‘good’ quality. A robust association was found between interpersonal sensitivity and paranoia in clinical and general population samples alike, regardless of the method of assessment of both paranoia and interpersonal sensitivity. Although this finding was more pronounced in studies of trait paranoia, it is likely that differences in study purpose, measurement, and power explain these differences. Findings from this review support the hypothesis that feelings of personal vulnerability and exaggerated socially evaluative concerns are central for both onset and maintenance of paranoid symptoms, suggesting avenues for future research in targeted interventions.
PERIODS OF DRINFELD MODULES AND LOCAL SHTUKAS WITH COMPLEX MULTIPLICATION
Authors: Hartl Urs , Singh Rajneesh Kumar
Published: March 2018

Colmez [Périodes des variétés abéliennes a multiplication complexe,Ann. of Math. (2)138(3) (1993), 625–683; available athttp://www.math.jussieu.fr/∼colmez] conjectured a product formula for periods of abelian varieties over number fields with complex multiplication and proved it in some cases. His conjecture is equivalent to a formula for the Faltings height of CM abelian varieties in terms of the logarithmic derivatives at$s=0$of certain Artin$L$-functions. In a series of articles we investigate the analog of Colmez’s theory in the arithmetic of function fields. There abelian varieties are replaced by Drinfeld modules and their higher-dimensional generalizations, so-called$A$-motives. In the present article we prove the product formula for the Carlitz module and we compute the valuations of the periods of a CM$A$-motive at all finite places in terms of Artin$L$-series. The latter is achieved by investigating the local shtukas associated with the$A$-motive.
Retraction Note: Recombination spot identification Based on gapped k-mers
Authors: Wang Rong , Xu Yong , Liu Bin
Published: March 2018

Scientific Reports 6: Article number: 23934; published online: 31 March 2016; updated: 7 December 2016; updated: 10 November 2017; updated: 20 March 2018 This Article reports an application of methodology originally reported in Reference 33 to recombination spot identification. Reference 33 (Ghandi,M.
Scan-rate and vacuum pressure dependence of the nucleation and growth dynamics in a spin-crossover single crystal: the role of latent heat
Authors: Ridier Karl , Rat Sylvain , Salmon Lionel , Nicolazzi William , Molnár Gábor , Bousseksou Azzedine
Published: March 2018

A heat exchange dependence was evidenced on both the hysteresis properties and the switching dynamics of a spin-crossover single crystal.
One-step assembly of CuMo2S3 nanocrystals for the synergistic effect of photothermal therapy and photodynamic therapy
Authors: Huang Zhi , Liu Xijian , Deng Guoying , Yuan Haikuan , Wang Qiugeng , Zhang Lijuan , Lu Jie
Published: March 2018

A novel PVP conjugated CuMo2S3 nanocrystal was synthesized by a one-step approach and showed an excellent synergistic effect of photothermal therapy and photodynamic therapy for tumor treatment.
An examination of preservice elementary teachers’ representations about chemistry in an intertextuality- and modeling-based course
Authors: Ryu Minjung , Nardo Jocelyn Elizabeth , Wu Meng Yang Matthew
Published: March 2018

The chemistry education aspect of elementary teacher education faces a unique set of challenges. On one hand, preservice and in-service elementary teachers tend to not like chemistry and have negative feelings toward chemistry. On the other hand, learning chemistry requires reasoning about natural phenomena from the submicroscopic perspective that deals with the properties and behaviors of unobservable particles. The present study addresses these challenges in chemistry education for preservice elementary teachers (PSETs) by designing a chemistry curriculum that improves the relevance of chemistry learning to students via intertextuality and modeling practices. An analysis of chemistry representations that PSETs generated before and after taking the designed chemistry course demonstrates that they initially perceived chemistry as vivid chemical changes occurring in lab spaces or a discipline related to atoms while failing to provide connections between the chemical reactions and atoms. After taking the course, many students came to see doing chemistry as epistemic practices that construct submicroscopic explanations for observable phenomena and its relevance to everyday lives such as food, car emissions, and their local surroundings. They also came to recognize various epistemic roles that people play in doing chemistry. We provide important implications for engaging PSETs in chemical reasoning and designing chemistry curricula that are more approachable and build on learners’ knowledge resources.
Fabrication of a hierarchical NiO/C hollow sphere composite and its enhanced supercapacitor performance
Authors: Liu Tao , Zhang Liuyang , Cheng Bei , You Wei , Yu Jiaguo
Published: March 2018

A prepared hierarchical NiO/C hollow sphere composite delivers an excellent electrochemical performance.
Relationship between crystal structures and photochromic properties of N-salicylideneaminopyridine derivatives
Authors: Sugiyama Haruki , Uekusa Hidehiro
Published: March 2018

Photochromic properties of the N-salicylideneaminopyridine (SAP) crystals were related to both the molecular conformation and the packing efficiency.
Single crystal growth, transport and scanning tunneling microscopy and spectroscopy of FeSe1−xSx
Authors: Chareev Dmitriy , Ovchenkov Yevgeniy , Shvanskaya Larisa , Kovalskii Andrey , Abdel-Hafiez Mahmoud , Trainer Dan J. , Lechner Eric M. , Iavarone Maria , Volkova Olga , Vasiliev Alexander
Published: March 2018

“Ampoule in ampoule” design to grow single crystals of FeSe1−xSx.
Methanol synthesis via CO2 hydrogenation over CuO–ZrO2 prepared by two-nozzle flame spray pyrolysis
Authors: Tada Shohei , Larmier Kim , Büchel Robert , Copéret Christophe
Published: March 2018

Controlled CuO–ZrO2 particle synthesis by tuning the flame spray pyrolysis conditions allow generating highly active and methanol selective CO2 hydrogenation catalysts.
Correction: Isostructural lanthanide-based metal–organic frameworks: structure, photoluminescence and magnetic properties
Authors: Luo Li-Lin , Qu Xiang-Long , Li Zheng , Li Xia , Sun Hao-Ling
Published: March 2018

Correction for ‘Isostructural lanthanide-based metal–organic frameworks: structure, photoluminescence and magnetic properties’ by Li-Lin Luo et al., Dalton Trans., 2018, 47, 925–934.
Unprecedented catalytic performance in amine syntheses via Pd/g-C3N4 catalyst-assisted transfer hydrogenation
Authors: Xu Xingliang , Luo Jiajun , Li Liping , Zhang Dan , Wang Yan , Li Guangshe
Published: March 2018

A Pd/g-C3N4 catalyst exhibited a superb performance in the transfer hydrogenation of nitro compounds to generate their corresponding primary and secondary amines with formic acid as the hydrogen donor in aqueous solution.
Inter-technique comparison of PIXE and XRF for lake sediments
Authors: El Ouahabi M. , Chêne G. , Strivay D. , Vander Auwera J. , Hubert-Ferrari A.
Published: March 2018

In this paper we describe a validation procedure for the chemical analysis of major elements and some minor elements such as Sr, Cr, Ni, Zn and Zr in heterogeneous geological sediments.
Light-weight 3D Co–N-doped hollow carbon spheres as efficient electrocatalysts for rechargeable zinc–air batteries
Authors: Chen Shengmei , Cheng Junye , Ma Longtao , Zhou Shanke , Xu Xiuwen , Zhi Chunyi , Zhang Wenjun , Zhi Linjie , Zapien J. Antonio
Published: March 2018

Facile synthesis of Co–N-doped hollow carbon spheres for rechargeable zinc–air batteries and the effect of their Co doping contents on ORR performance.
Correction: A smart pH-responsive nano-carrier as a drug delivery system for the targeted delivery of ursolic acid: suppresses cancer growth and metastasis by modulating P53/MMP-9/PTEN/CD44 mediated multiple signaling pathways
Authors: Jiang Kai , Chi Ting , Li Tao , Zheng Guirong , Fan Lulu , Liu Yajun , Chen Xiufen , Chen Sijia , Jia Lee , Shao Jing-Wei
Published: March 2018

Correction for ‘A smart pH-responsive nano-carrier as a drug delivery system for the targeted delivery of ursolic acid: suppresses cancer growth and metastasis by modulating P53/MMP-9/PTEN/CD44 mediated multiple signaling pathways’ by Kai Jiang et al., Nanoscale, 2017, 9, 9428–9439.
The synthesis of mono-alkyl phosphates and their derivatives: an overview of their nature, preparation and use, including synthesis under plausible prebiotic conditions
Authors: Fiore Michele
Published: March 2018

Nucleic acids, phospholipids and other organic phosphates play central roles in biological pathways.
Correction: Synthesis of the 10-oxabicyclo[5.2.1]decane framework present in bioactive natural products
Authors: Montaña Ángel M. , Ponzano Stefano , Sanasi Maria-Filomena , Kociok-Köhn Gabriele
Published: March 2018

Correction for ‘Synthesis of the 10-oxabicyclo[5.2.1]decane framework present in bioactive natural products’ by Ángel M. Montaña et al., Org. Biomol. Chem., 2018, 16, 1557–1580.
Self-assembly of hairy disks in two dimensions – insights from molecular simulations
Authors: Borówko Małgorzata , Rżysko Wojciech , Sokołowski Stefan , Staszewski Tomasz
Published: March 2018

We report the results of large scale molecular dynamics simulations conducted for sparsely grafted disks in two-dimensional systems.
CGA-N12, a peptide derived from chromogranin A, promotes apoptosis of Candida tropicalis by attenuating mitochondrial functions
Authors: Li Ruifang , Zhang Ruiling , Yang Yanhui , Wang Xueqin , Yi Yanjie , Fan Pei , Liu Zhengwei , Chen Chen , Chang Junpeng
Published: March 2018

CGA-N12 (the amino acid sequence from the 65th to the 76th residue of the N-terminus of chromagranin A) is an antifungal peptide derived from human chromogranin A (CGA). In our previous investigation, CGA-N12 was found to have specific anti-candidal activity, though the mechanism of action remained unclear. Here, we investigated the effects of CGA-N12 on mitochondria. We found that CGA-N12 induced an over-generation of intracellular reactive oxygen species and dissipation in mitochondrial membrane potential, in which the former plays key roles in the initiation of apoptosis and the latter is a sign of the cell apoptosis. Accordingly, we assessed the apoptosis features of Candida tropicalis cells after treatment with CGA-N12 and found the following: leakage of cytochrome c and uptake of calcium ions into mitochondria and the cytosol; metacaspase activation; and apoptotic phenotypes, such as chromatin condensation and DNA degradation. In conclusion, CGA-N12 is capable of inducing apoptosis in C. tropicalis cells through mitochondrial dysfunction and metacaspase activation. Antifungal peptide CGA-N12 from human CGA exhibits a novel apoptotic mechanism as an antifungal agent.
Toward coordinated look‐ahead reactive power optimisation for distribution networks with minimal control
Authors: Ding Min , Chiang Hsiao‐Dong , Li Peng
Published: March 2018

A coordinated look‐ahead reactive power optimisation method is proposed to minimise the required number of operating control devices for a time horizon of 24 h. The aim is to determine, via solving a mixed integer non‐linear programming (MINLP) problem, optimum value settings of transformer taps, capacitor banks and reactive power output of distributed generators (DGs) based on the day‐ahead load demand and active power output of DGs satisfying the engineering and operational constraints. The proposed method employs a three‐stage method: assessment stage, time‐period‐partitioning stage, and coordinated reactive power optimisation stage. The first stage assesses the hourly voltage profile and available delivery capability margin of the system, while the time‐period‐partitioning stage uses clustering algorithm based on power‐flow solution to partition time periods into coherent time durations. The MINLP problem is solved in the proposed coordinated optimisation stage. A modified IEEE13 case and IEEE123 case are used to verify the effectiveness of the proposed three‐stage method.
Distributed broadband phased‐MIMO sonar for detection of small targets in shallow water environments
Authors: Pan Xiang , Li Si , Pan Chen
Published: March 2018

A joint processing framework is proposed for a distributed‐phased multiple‐input–multiple‐output (phased‐MIMO) sonar for detection of a small target. A transmit–receive‐interactive strategy is combined with the array processing for a high signal‐to‐noise ratio (SNR) required by the distributed MIMO detection. The former provides the approximate location of a likely target by transmitting a probe signal to sense the environment. Then, the transmitting beams are steered to illuminate the target from different angles by which target echoes are enhanced and reverberation is suppressed. It is seen from the receiver operating characteristic curves that the distributed‐phased‐MIMO sonar is intermediate to the distributed MIMO sonar and the phased‐array sonar in the low‐SNR scenario. In the at‐lake experiments of localisation of a small target, the distributed‐phased‐MIMO sonar system performs better than other two sonar systems due to exploiting the diversity gain and the transmitting array gain.
Prevalence of Neospora spp. in donkeys in China
Authors: Cong Wei , Nie Lan-Bi , Qin Si-Yuan , Wang Wei-Li , Qian Ai-Dong , Meng Qing-Feng
Published: March 2018

This study was conducted to detect specific anti-Neospora antibodies using a commercial competitive-inhibition ELISA kit, and to evaluate the risk factors for Neospora spp. infection. Out of a total of 2,228 donkey sera collected in three provinces in China, 211 (9.5%) were found to be positive for anti-Neospora antibodies. Statistical analysis revealed that age (p = 0.019, OR = 1.62, 95%CI: 1.08-2.44), feeding status (p < 0.001, OR = 3.79, 95%CI: 2.65-5.43), miscarriage history (p = 0.006, OR = 2.56, 95%CI: 1.27-4.01), and contact with dogs (p < 0.001, OR = 2.69, 95%CI: 1.86-3.88) were significant risk factors for Neospora spp. infection. This is the first evidence of Neospora infection in donkeys in China.
Validated Chiral LC-ESI-MS/MS Method for the Simultaneous Quantification of Darolutamide Diastereomers and Its Active Metabolite in Mice Plasma: Application to a Pharmacokinetic Study
Authors: Balaji Narayan , Sulochana Suresh , Saini Neeraj , A. Siva , Mullangi Ramesh
Published: March 2018

A simple, selective and reliable LC-MS/MS method was developed and validated for the simultaneous quantitation of darolutamide diastereomers (diastereomer-1 and diastereomer-2) and its active metabolite i. e. ORM-15341 in mice plasma using warfarin as an internal standard (IS) as per the regulatory guidelines. Plasma samples were extracted by liquid-liquid extraction and the chromatographic separation was achieved on a Chiralpak IA column with an isocratic mobile phase 5 mM ammonium acetate:absolute alcohol (20:80, v/v) at a flow rate of 1.0 mL/min. Detection and quantitation was done by multiple reaction monitoring on a triple quadrupole mass spectrometer following the transitions: m/z 397→202, 395→202 and 307→250 for darolutamide diastereomers, ORM-15341 and the IS, respectively in the negative ionization mode. The calibration curves were linear (r>0.992) in the range of 100–2400 ng/mL for all the analytes. The intra- and inter-day precisions were in the range of 1.25–10.2 and 1.58-12.3; 2.85-5.68 and 1.85-9.58; 2.34-12.1 and 2.58-7.38 for diastereomer-1, diastereomer-2 and ORM-15341, respectively. Both diastereomers and ORM-15341 were found to be stable under different stability conditions. The validated method was applied to a pharmacokinetic study in mice.
Stroke in Young Adults: The Role of Paradoxical Embolism
Authors: Chant Harvey , McCollum Charles
Published: March 2018

Stroke in young adults may be devastating and frequently no cause can be found. However, there is ample literature to suggest an association between cryptogenic stroke in young people and paradoxical embolisation via a venous to arterial circulation shunt (v-aCS), commonly due to patent foramen ovale (PFO). Although paradoxical embolisation is assumed to be a rare event, this review suggests that it is an important or even dominant cause of stroke in young people and that a transcranial Doppler (TCD) technique may be the investigation of choice to identify v-aCS.

Appendix I, II on pp. 26-7
Fibrinogen Matsumoto V: a Variant with Aα19 Arg → Gly (AGG → GGG)
Authors: Tanaka Hitoshi , Terasawa Fumiko , Ito Toshiro , Tokunaga Shin-ichi , Ishida Fumihiro , Kitano Kiyoshi , Kiyosawa Kendo , Okumura Nobuo
Published: March 2018

Fibrinogen Matsumoto V (M-V) is a dysfibrinogen identified in a 52-year-old woman with systemic lupus erythematous. The triplet AGG encoding the amino acid residue Aα19 was replaced by GGG, resulting in the substitution of Arg→Gly. Residue Aα19 has been shown to be one of the most important amino acids in the so-called ‘A’ site or α-chain knob. The thrombin-catalyzed release of fibrinopeptide A from M-V fibrinogen was only slightly delayed yet release of fibrinopeptide B was significantly delayed. Both thrombin-catalyzed fibrin polymerization and fibrin monomer polymerization were markedly impaired compared to normal fibrinogen. In addition, reptilase-catalyzed fibrin polymerization of M-V was much more impaired than thrombin-catalyzed fibrin polymerization. These results indicate ‘B’ and/or ‘b’ site of M-V fibrinogen play a more important role in thrombin- catalyzed fibrin polymerization than that of normal control fibrinogen.
Platelets Exposed to Elevated Levels of Endogenous Thrombopoietin In Vivo Have a Reduced Response to Megakaryocyte Growth and Development Factor In Vitro
Authors: Nishiyama Uichi , Morita Haruhiko , Torii Yoshifumi , Kuwaki Tomoaki , Shimizu Eiko , Akahori Hiromichi , Kato Takashi , Miyazaki Hiroshi
Published: March 2018

Thrombopoietin (TPO), or megakaryocyte growth and development factor (MGDF), has been shown to potentiate the sensitivity of normal human platelets to various agonists in vitro. The present study investigated the functional and biochemical properties of platelets from mice rendered thrombocytopenic by sublethal irradiation with regard to the reactivity to recombinant murine MGDF (rmMGDF) in vitro. During the course of reversible thrombocytopenia following irradiation, platelets from irradiated mice which had lower platelet counts and reciprocally higher plasma TPO levels showed lower reactivity to rmMGDF in agonist-induced platelet aggregation. Intravenous injections of recombinant soluble murine c-Mpl (sMpl), which has the ability to capture TPO, after irradiation restored the reactivity of platelets at the platelet nadir to rmMGDF. On the other hand, platelets prepared from normal mice 3 h after a single intravenous injection of pegylated rmMGDF did not respond to rmMGDF. There was a marked decrease in c-Mpl and Janus kinase 2 (JAK2) in platelets from irradiated mice at the platelet nadir. Similar results were observed with platelets from mice administered pegylated rmMGDF. JAK2 was only moderately decreased, however, in platelets from mice given sMpl after irradiation. These results indicate that exposure of platelets to increased endogenous TPO levels in vivo in thrombocytopenic mice leads to a reduction in the platelet reactivity to rmMGDF in vitro. Further, these results suggest that the c-Mpl-mediated signaling pathway, which is essential for the priming effect of rmMGDF, is defective in thrombocytopenic murine platelets.
Lack of In Vivo Function of CD31 in Vascular Thrombosis
Authors: Schmits R. , Kunz D. , Menger M. D. , Vollmar B.
Published: March 2018

A murine model of endothelial cell injury-based vascular thrombosis was used to test the role of platelet-endothelial cell adhesion molecule-1 (PECAM-1, CD31) in blood cell aggregate formation and vessel occlusion in vivo. Photochemically-induced thrombus formation was analyzed in detail using intravital fluorescence microscopy of individual microvessels in cremaster muscle preparations of CD31-deficient and wildtype mice. In venules, epi-illumination induced rapid thrombus formation with first platelet deposition after 0.56 ± 0.11min and complete vessel occlusion within 5.05 ± 0.45 min. In arterioles, thrombus formation was markedly delayed with first platelet deposition after 3.03 ± 0.47 min and complete vessel occlusion within 10.04 ± 1.26 min. Kinetics of thrombus formation in both venules (first platelet deposition: 0.52 ± 0.1 min; vessel occlusion: 5.03 ± 0.52 min) and arterioles (first platelet deposition: 3.06 ± 0.68 min; vessel occlusion: 10.02 ± 1.38 min) of CD31-deficient mice was found almost identical compared with that in wildtype animals. Tail bleeding time was 233 ± 24 s in wildtype and 243 ± 32 s in CD31-deficient mice. Moreover, CD31-deficient and wildtype mice revealed comparable interaction of leukocytes to endothelium. This study shows for the first time in vivo that CD31 is not critically involved in blood cell thrombus formation upon endothelial cell injury.
New and Effective Treatment of Experimentally Induced Venous Thrombosis with Anti-inflammatory rPSGL-Ig
Authors: Myers Daniel , Wrobleski Shirley , Londy Frank , Fex Beverly , Hawley Angela , Schaub Robert , Greenfield Lazar , Wakefield Thomas
Published: March 2018

P-selectin antagonism decreases thrombosis and inflammation in animal models of venous thrombosis (VT) prophylaxis. This study defines results using a P-selectin receptor antagonist for VT treatment.

Eight juvenile baboons underwent 6 h of iliofemoral venous stasis to produce an occlusive VT. Two days later, animals were treated for 14 days with rPSGL-Ig, 4 mg/kg (n3), LMWH (n2) or saline (n3) and treatment continued weekly (rPSGL-Ig) or daily (LMWH, saline). The animals were examined and sacrificed 14 days after treatment initiation (n4) or on day 90 (n4).

Percent spontaneous vein reopening revealed a significant increase (p <0.05) in the proximal iliac vein in rPSGL-Ig and LMWH animals compared to controls (62%, 70% vs 8%), without differences in inflammation. No anticoagulation, thrombocytopenia, or wound complications were found in rPSGL-Ig animals. At 90 days, recanalization with iliac vein valve competence was found in treated animals.

rPSGLIg successfully treated established VT without anticoagulation.
Human Factor VIII Inhibitor Alloantibodies with a C2 Epitope Inhibit Factor Xa-catalyzed Factor VIII Activation: A new Anti-factor VIII Inhibitory Mechanism
Authors: Nogami Keiji , Nishiya Katsumi , Sakurai Yoshihiko , Tanaka Ichiro , Giddings John , Saenko Evgueni , Yoshioka Akira , Shima Midori
Published: March 2018

Factor VIII (FVIII) inhibitor alloantibodies react with the A2, C2, or A3-C1 domains of FVIII and inactivate FVIII activity. We recently demonstrated that an anti-C2 monoclonal antibody with a Val2248Gly2285 epitope, inhibited factor Xa (FXa)-catalyzed FVIII activation, and that a FXa binding site for FVIII was located within residues Thr2253-Gln2270. In this study, we investigated whether anti-C2 alloantibodies inhibit FXa-catalyzed FVIII activation. Anti-C2 alloantibodies from four patients inhibited FVIII activation by FXa in onestage clotting assay. Furthermore, analysis by SDS-PAGE showed that all alloantibodies inhibited FVIII proteolytic cleavage by FXa independently of phospholipid. To confirm direct inhibition of FVIII and FXa interaction, we examined the effect of alloantibodies on FVIII binding to anhydro-FXa, a catalytically inactive FXa, in ELISA. All alloantibodies and C2-affinity purified F(ab)’2 preparations inhibited FVIII binding to anhydro-FXa dose-dependently. Our results revealed a new inhibitory mechanism of FVIII, mediated by inhibition of FXa in the presence of anti-C2 alloantibodies.
Hydroxychloroquine Reverses Platelet Activation Induced by Human IgG Antiphospholipid Antibodies
Authors: Espinola Ricardo , Ghara Azzudin , Harris E. , Pierangeli Silvia
Published: March 2018

Prothrombotic properties of antiphospholipid (aPL) antibodies may be explained in part by their ability to enhance the activation of platelets pre-treated with low doses of ADP or thrombin. The antimalarial drug hydroxychloroquine (HQ) has been used successfully in prevention of postoperative thrombosis and in treatment of patients with SLE or APS. In one study, administration of HQ reversed the thrombogenic properties of aPL in mice. However, the mechanism of action of HQ in preventing thrombosis is not clearly understood. In order to explore this further, the effects of HQ on activation of platelets by aPL in the presence of a thrombin agonist was studied. The changes in the expression of GPIIb/IIIa (CD41a) and GPIIIa (CD61) on platelet membrane by flow cytometry were used as indicators of platelet activation. Citrated whole blood from a healthy donor was treated at room temperature with suboptimal doses of a thrombin agonist receptor peptide (TRAP) and affinity-purified aPL antibodies, in the presence and in the absence of hydroxychloroquine (1 mM). TRAP increased the expression of GPIIb/IIIa and GPIIIa on platelet surface. The treatment of the platelets with the six aPL antibodies in the presence of 12 nMol/ml TRAP further increased the expression of GPIIb/IIIa by 42.3 ± 12.3% and the expression of GPIIIa was further incremented by 46.8 ± 13.5%. The effects of aPL and TRAP on expression of platelet surface markers of activation was completely abrogated by HQ in a dose-dependent fashion and was effective at concentrations of HQ as low as 25 µg/ml (0.0125 mM). This suggests at least one possible mechanism by which HQ may prevent thrombosis. This may have important implications in treatment of thrombosis in APS patients.
New Aspects in Thrombosis Research: Possible Role of Mast Cells as Profibrinolytic and Antithrombotic Cells
Authors: Baghestanian M. , Bankl H. C. , Sillaber C. , Sperr W. R. , Wojta J. , Binder B. R. , Lechner K. , Valent P.
Published: March 2018

Venous thromboembolism represents a significant cause of morbidity worldwide. The factors that underly thrombophilia are manifold. The concept of Virchow defines the well known triad of stasis, humoral factors, and pathologies of the vascular wall. In the current article, an additional factor, the “accumulation of repair cells” is discussed. This novel concept highlights the mast cell that accumulates around thrombosed vessels and provides a number of important repair molecules including heparin, profibrinolytic tPA, and fibrinogenolytic β-tryptase. Thus, mast cell recruitment and activation may result in local thrombolysis and prevention of coagulation. In line with this concept, mast cell-deficient mice are more susceptible to lethal thrombogenic stimuli compared to normal mice. The factors (cytokines) that trigger mast cell accumulation and release of repair molecules have also been identified – the most important one appears to be stem cell factor (SCF). All in all, our novel concept suggests that the patho-physiology of thrombosis may involve a “physiologic” cell that provides the same repair molecules that are used for treatment of thrombotic disorders by the physician. Whether an altered availability of components of this cellular repair system can predispose for thrombophilia remains to be determined.
Complete Defect in vWF-cleaving Protease Activity Associated with Increased Shear-induced Platelet Aggregation in Thrombotic Microangiopathy
Authors: Ajzenberg Nadine , Denis Cécile , Veyradier Agnès , Girma Jean-Pierre , Meyer Dominique , Baruch Dominique
Published: March 2018

Von Willebrand factor (vWF) cleaving metalloprotease activity represents an important factor in understanding the pathophysiology of thrombotic microangiopathies (TMA). Thrombotic events, leading to dramatic complications, occur preferentially in the microvasculature. Our aim was to determine the ability of TMA plasma with a complete deficiency of protease activity to promote shear-induced platelet aggregation (SIPA) at high shear rates using a coaxial cylinder shearing device. We have demonstrated the ability of four out of seven TMA plasma to aggregate normal washed platelets at 4,000 s−1. In these four TMA plasma, significant SIPA was obtained, whereas control plasma did not induce more SIPA than buffer. The % of unusually large (UL) multimers in TMA plasma varied from 1 to 18%. Surprisingly, the extent of SIPA in TMA plasma appeared independent of the percentage of UL multimers. Interestingly, anti-GPIb antibody 6D1 could block completely this pathological aggregation, opening new therapeutic possibilities. In contrast, none of eight other TMA patients’ plasma with a normal protease activity, exhibited any increase of SIPA compared with control plasma. These results strongly suggest that the deficiency of vWF-cleaving protease appears to be necessary, but not sufficient for elevated SIPA. In contrast, the % of UL is not associated with increased SIPA.
Functional Role of p38 Mitogen Activated Protein Kinase in Platelet Activation induced by a Thromboxane A2 Analogue and by 8-iso-prostaglandin F2
α
Authors: Gaino Stefania , Zuliani Valeria , Tommasoli Rosa , Benati Donatella , Ortolani Riccardo , Zancanaro Carlo , Berton Giorgio , Santonastaso Clara , Minuz Pietro
Published: March 2018

We investigated similarities in the signaling pathways elicited by the F2 isoprostane 8-iso-PGF2α and by low doses of U46619 to induce platelet activation. Both 0.01-0.1 µmol/L U46619 and 0.01-1 µmol/L 8-isoPGF2α triggered shape change and filopodia extension, as well as adhesion to immobilized fibrinogen of washed platelets. At these doses the two platelet agonists failed to trigger secretion and aggregation, which were however induced by higher doses of U46619 (0.1-1 µmol/L). SB203580 (1-10 µmol/L), a specific inhibitor of the p38 mitogen activated protein (MAP) kinase blunted platelet shape change and adhesion induced by 0.05-1 µmol/L 8-iso-PGF2α and by 0.01 µmol/L U46619. These platelet responses were also inhibited by 20 µmol/L cytochalasin D, an inhibitor of actin polymerization, and 50 µmol/L piceatannol, an inhibitor of the Syk tyrosine kinases. Both 8-iso-PGF2α and U46619-induced p38 MAP kinase phosphorylation in suspended platelets and this was inhibited by piceatannol, indicating that Syk activation occurs upstream p38 MAP kinase phosphorylation. These findings suggest that the signaling pathway triggered by both 8-iso-PGF2α and low concentrations of U46619 to induce platelet adhesion and shape change implicates Syk, the p38 MAP kinase, and actin polymerization.
Increased Angiostatin Levels in Bronchoalveolar Lavage Fluids from ARDS Patients and from Human Volunteers after Lung Instillation of Endotoxin
Authors: Lijnen H. , Suffredini Anthony , Pepper Michael , Steinberg Kenneth , Martin Thomas , Pugin Jérôme , Lucas Rudolf
Published: March 2018

Acute respiratory distress syndrome (ARDS) is characterized by a disruption of the alveolar-capillary barrier, due to both an epithelial and an endothelial dysfunction. Whereas epithelial apoptosis seems to be mainly mediated by Fas ligand, the mediators of endothelial damage remain to be identified. Angiostatin, a powerful inhibitor of angiogenesis in vivo, also specifically induces apoptosis in endothelial cells. The concentration of various enzymes that cleave angiostatin from plasminogen was reported to be significantly increased in bronchalveolar lavage (BAL) fluids from patients with ARDS. Therefore, in this study, we investigated whether angiostatin was generated during the pulmonary inflammatory response of both healthy subjects challenged with endobronchial endotoxin and in patients with ARDS. We found significantly elevated angiostatin levels in BAL fluids from patients at risk for and with early ARDS (up to 0.022% and 0.018% of total protein, respectively), as well as in BAL fluids from volunteers treated with endotoxin (up to 1.17% of total protein), as compared to BAL fluids from control patients (<0.005% of total protein). These data suggest that angiostatin may contribute to the endothelial damage observed in ARDS, probably via an increased permeability of the alveolar capillary barrier, allowing for an intra-alveolar processing of its precursor plasminogen.
Anticoagulant and Membrane-degrading Effects of Secretory (Non-pancreatic) Phospholipase A2 Are Inhibited in Plasma
Authors: Billy Didier , Speijer Han , Zwaal Robert , Hack Erik , Hermens Wim
Published: March 2018

Plasma concentrations of secretory (non-pancreatic) phospholipase A2 (sPLA2) may rise 1000-fold during inflammation, and this acute phase response has been related to anticoagulant effects. In the present study this hypothesis was further investigated.

Prothrombinase activity was measured for model membranes mimicking the phospholipid composition of the outer membrane of resting and activated blood platelets. Using ellipsometry, membrane degradation by sPLA2 could be measured simultaneously with inhibition of thrombin production. The same technique was used to study clotting, by the sudden appearance of fibrin strands on the membrane. Results were compared with the effects of sPLA2 on the activation of washed platelets and platelets in plasma.

In buffer solution, model membranes were degraded by (patho)physiological concentrations of sPLA2. Even when only partially degraded, membranes rapidly lost their prothrombinase activity, indicating preferential degradation of phosphatidylserine. Addition of diluted plasma interfered with membrane degradation, and also with inhibition of prothrombinase activity. In agreement with these observations, sPLA2 inhibited thrombin production and annexin V-binding of activated washed platelets, but had no effects on platelet activation or clotting in plasma. These findings indicate that the elevated plasma sPLA2 concentrations observed in inflammatory disease will not reduce hypercoagulability in such patients.
Polymorphonuclear Leucocytes Have Two Opposing Roles in Fibrinolysis
Authors: Moir E. , Robbie L. A. , Bennett B. , Booth N. A.
Published: March 2018

Polymorphonuclear leucocytes (PMN) are important in the resolution of human thrombi, with u-PA as a key player. We have shown that the u-PA activity of PMN depends on the presence of plasma; the study presented here provides an explanation for that requirement. Here we show that PMN degraded scu-PA and also tcu-PA, t-PA and plasmin, resulting in loss of fibrinolytic activity. Plasma protected against this degradation; α1-antitrypsin was identified as a protective factor. Purified human neutrophil elastase mirrored the effects of PMN, again neutralized by plasma inhibitors. These findings illustrate the dual role of PMN in the breakdown of thrombi, in that they contribute both u-PA, which lyses fibrin, and other proteases, including elastase, which can cleave fibrin and plasminogen activators/plasmin. Similarly, plasma can potentiate fibrinolysis by neutralization of PMN elastase, in addition to direct inhibition of fibrinolytic proteases. Our previous studies show that PMN in thrombi are mostly pro-fibrinolytic; the antifibrinolytic role defined here may be important in other pathologies where fibrin persists.
The R2-haplotype associated Asp2194Gly mutation in the light chain of human factor V results in lower expression levels of FV, but has no influence on the glycosylation of Asn2181
Authors: Dirven Richard , Vos Hans , Bertina Rogier , Kolfschoten Marijn
Published: March 2018

The R2 haplotype of the FV gene spans from exon 8 through 25 and comprises several strongly linked polymorphisms in the FV gene, including some missense mutations. Carriership of the R2-FV allele has been associated with reduced plasma FV levels, increased FV1/FV2 ratios and mild APC resistance. Some studies have reported that carriership of the R2-FV allele is associated with an increased risk of venous thombosis. At this moment, the individual contribution to the R2-associated phenotypes of the different mutations linked to the R2 haplotype of FV is unclear. The main objective of our study was to obtain insight in the influence of the R2-related Asp2194Gly mutation on FV expression, FV structure and FV function using B-domainless rFV mutants. Replacing Asp at position 2194 by Gly resulted in a more than threefold reduction of rFV expression compared to rFV wild-type. Therefore, we propose that the R2-linked Asp2194Gly mutation is an important determinant of the association of the R2-FV allele with lower FV levels. Furthermore, the light chains from Asp2194Gly containing rFV mutants showed similar molecular weights as the light chains of the non-glycosylated rFVwt or the plasma FV2 isoform, indicating that glycosylation at Asn2181 is not stimulated by the presence of a glycine in position 2194. Finally, the apparent K
d for dissociation of the FXaVa complex (K
1/2Xa) was not higher in rFV mutants with the Asp2194Gly mutation than for rFVwt, suggesting that also the affinity for negatively charged phospho-lipids is not affected by substitution of Asp into Gly at position at 2194.
Compliance and stability of INR of two oral anticoagulants with different half-lives: a randomised trial
Authors: Quenet Sara , Buchmüller-Cordier Andréa , Reynaud Jacqueline , Tardy-Poncet Brigitte , Thirion Christine , Decousus Hervé , Mismetti Patrick , Laporte Silvy
Published: March 2018

The aim of the study was to assess the respective roles of the half-life of elimination of oral anticoagulants and patient education as causes of instability of anticoagulation level in patients on oral anticoagulant therapy. Patients were randomised to receive either warfarin (long half-life) or acenocoumarol (short half-life) and either intensive or standard education, according to a factorial design. Instability of oral anticoagulant therapy was evaluated by the percentage of INRs and the time within the target range, and the variability between successive measurements. Compliance was assessed by means of electronic pill bottles. Eighty-six patients were included. Apart from the variability index, instability was similar between groups. Correlations between compliance and instability were observed only in the acenocoumarol group. No difference was found between the education groups. In patients starting oral anticoagulant therapy, dose determination may be the most important factor contributing to instability.
Age at first treatment and immune tolerance to factor VIII in severe hemophilia
Authors: Mauser-Bunschoten Eveline , Fischer Kathelijn , van den Berg Marijke , van der Bom Johanna
Published: March 2018

Findings from a recent study suggest that earlier start of treatment with factor VIII in patients with severe hemophilia is associated with a higher risk to develop inhibitors.

We set out to assess the association between age of first administration of clotting factor VIII and the risk to develop inhibitors in infants with severe hemophilia A.

This work was a cohort study, carried out in the national hemophilia treatment center. The study included eighty-one consecutive patients with severe hemophilia A who received their first dose of factor VIII between 1975 and 1998. Patients were followed until their last visit in 2001 or 2002.

The average follow-up was 16 years (range 3-26). Persistent inhibitory antibodies developed in 12 of 81 patients (15%).

Cumulative incidence at 100 exposure days was 34% (95% confidence interval 7-61%) in patients starting therapy before the age of 6 months, 20% (4-36%) in patients starting therapy between 6 months and 1 year, 13% (0-27%) in those starting therapy between 1 and 1.5 years, and 0% in those who started therapy beyond 1.5 years of age (p for trend 0.03).

Our findings confirm that age of first factor VIII administration in children with severe hemophilia A is inversely associated with the risk to develop antibodies against factor VIII. The role of confounding factors such as the type of factor VIII mutation and environmental factors needs to be evaluated.
Obesity: risk of venous thrombosis and the interaction with coagulation factor levels and oral contraceptive use
Authors: Abdollahi Morteza , Cushman Mary , Rosendaal Frits
Published: March 2018

Deep vein thrombosis (DVT) is a common disease with an annual incidence of about 1 in 1000. Many risk factors have already been studied, both genetic and acquired. It is unclear whether obesity affects thrombotic risk in unselected patients. Obesity is common, with a prevalence of 20-25% and may therefore have a considerable impact on the overall incidence of thrombosis. We evaluated the risk of thrombosis due to overweight and obesity using data from a large population based case-control study.

Four hundred and fifty-four consecutive patients with a first episode of objectively diagnosed thrombosis from three Anticoagulation Clinics in the Netherlands were enrolled in a case-control study. Controls were matched on age and sex to patients and were introduced by the patients. All patients completed a standard questionnaire and interview, with weight and height measured under standard conditions. The associations of obesity with clotting factor levels were studied to investigate possible mechanisms.

Obesity (BMI ≥30 kg/m2) increased the risk of thrombosis twofold (CI95: 1.5 to 3.4), adjusted for age and sex. Obese individuals had higher levels of factor VIII and factor IX, but not of fibrinogen. The effect on risk of obesity was not changed after adjustment for coagulation factors levels (fibrinogen, F VIII, F IX, D-dimer). The relative risk estimates were similar in different age groups and in both sexes, indicating a larger absolute effect in older age groups. Evaluation of the combined effect of obesity and oral contraceptive pills among women aged 15-45 revealed that oral contraceptives further increased the effect of obesity on the risk of thrombosis, leading to 10-fold increased risk amongst women with a BMI greater than 25 kg/m2 who used oral contraceptives.

Obesity is a risk factor for deep vein thrombosis. Among women with a BMI greater than 25 kg/m2 the synergistic effect with oral contraceptives should be considered when prescribing these.
Travel and the risk of symptomatic venous thromboembolism
Authors: ten Wolde Marije , Kraaijenhagen Roderik , Schiereck Jan , Hagen Petronella , Mathijssen Joost , Mac Gillavry Melvin , Koopman Maria , Büller Harry
Published: March 2018

Whether long-distance travel and symptomatic venous thromboembolism (VTE) are associated is debated. On the basis of the available literature a fair risk estimate cannot be obtained. We estimated an accurate odds ratio for the relationship between recent travelling and symptomatic VTE.

From three case-control studies consisting of 788 and 170 patients with clinically suspected deep vein thrombosis (DVT) and 989 patients with clinically suspected pulmonary embolism (PE) referred for diagnostic work-up, a pooled odds ratio for the relation between travel and symptomatic VTE was calculated. Cases were patients in whom the diagnosis was confirmed according to a diagnostic management strategy, whereas controls were patients in whom the diagnosis was excluded and who had an uneventful clinical follow-up. Patients were seen in the period April 1997 to September 2000. Travel history was recorded prior to diagnostic work-up.

The pooled odds ratio for the association between any travel and symptomatic venous thromboembolism was 0.9 (95% CI: 0.6-1.4). The median travel time was 7 h (quartile range 4 to 10 h). Separate analyses performed for different types of transport (plane, car, bus or train) yielded comparable odds ratios. The analysis for duration of travelling showed an increased odds ratio of 2.5 (95% CI: 1.0-6.2) in the category of 10-15 h of travelling.

This study shows that the average traveller does not have an increased risk for symptomatic venous thromboembolism. Only very long travelling (more than 10 h) may be associated with venous thromboembolic disease.
CD32-dependent platelet activation by a drug-dependent antibody to glycoprotein IIb/IIIa antagonists
Authors: Pedicord Donna , Dicker Ira , O’Neil Karyn , Breth Leah , Wynn Richard , Hollis Greogory , Billheimer Jeffrey , Stern Andrew , Seiffert Dietmar
Published: March 2018

Thrombocytopenia is observed with a frequency of up to 2% in patients treated with glycoprotein (GP) IIb/IIIa antagonists. We recently provided evidence that thrombocytopenia is caused by antibody binding to drug-induced conformational changes in GP IIb/IIIa. Here, we report that a murine monoclonal antibody binds to GP IIb/IIIa in an antagonist-dependent manner and activates platelets. Platelet stimulation is associated with a disruption of the phospholipid asymmetry, resulting in the assembly of catalytic active intrinsic Xase and prothrombinase complexes. Further mechanistic studies revealed that this response is (I) mediated in cis, (II) not associated with the formation of pro-thrombotic microparticles, and (III) requires intact platelet signaling and (IV) is blocked by increases in cAMP. The prothrombotic response is not observed using F(ab’)2 fragments and is blocked by incubation of platelets with neutralizing antibodies to the platelet FcγRIIa receptor (CD 32). Taken together, these observations suggest that GPIIb/IIIa antagonist-dependent antibody binding to the platelet fibrinogen receptor has the propensity to lead to CD32-mediated platelet activation and accelerated platelet clearance, leading to thrombocytopenia.