71 research outputs found

    Old beacon of hope when nothing else works

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    Does it still hold?

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    Membrane structure and interactions of a short Lycotoxin I anaiogue

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    Lycotoxin I and Lycotoxin II are natural anti-microbial peptides, that were identified in the venom of the Wolf Spider Lycosa carolinensis. These peptides were found to be potent growth inhibitors for bacteria (Escherichia coli) and yeast (Candida glabrata) at micromolar concentrations. Recently, shortened analogues of Lycol and LycoII have been reported to have decreased haemolytic effects. A shorter Lyco-I analogue studied, Lycol 1-15 (H-IWLTALKFLGKHAAK-NH2), was active only above 10 pm, but was also the least haemolytic. On the basis of these findings, we became interested in obtaining a deeper insight into the membrane activity of LycoI 1-15, as this peptide may represent the first major step for the future development of selective, i.e. non-haemolytic, Lycotoxin-based antibiotics. The interaction of this peptide with liposomes of different composition was studied by microcalorimetry [differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC)l and CD. The results obtained from the calorimetric and spectroscopic techniques were jointly discussed in an attempt to further understand the interaction of this peptide with model membranes. Copyright (c) 2007 European Peptide Society and John Wiley & Sons, Ltd

    Synthesis, structure, solution behaviour and biological evaluation of oxidovanadium(IV/V) complexes: Substrate specific DMSO assisted methylation of a thiosemicarbazone

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    The synthesis and characterization of an oxidovanadium(IV) [VIVO(L)(acac)] (1) and of two dioxidovanadium(V) [VVO2(L')] (2) and [VVO2(L)] (2a) complexes of the Schiff base formed from the reaction of 4-(p-fluorophenyl) thiosemicarbazone with pyridine-2-aldehyde (HL) is described.The oxidovanadium(IV) species [VIVO(L)(acac)] (1) was synthesized by the reaction of VIVO(acac)2 with the thiosemicarbazone HL in refluxing ethanol. The recrystallization of [VIVO(L)(acac)] (1) in DMF, CH3CN or EtOH gave the same product i.e. the dioxidovanadium(V) complex [VVO2(L)] (2a); however, upon recrystallization of 1 in DMSO a distinct compound [VVO2(L')] (2) was formed, wherein the original ligand L- is transformed to a rearranged one, L’-. In the presence of DMSO the ligand in complex 1 is found to undergo methylation at the carbon centre attached to imine nitrogen (aldimine) and transformed to the corresponding V VO2- species through in situ reaction. The synthesized HL and the metal 2 complexes were characterized by elemental analysis, IR, UV–Vis, NMR and EPR spectroscopy. The molecular structure of [VVO2(L')] (2) was determined by single crystal X–ray crystallography.The methylation of various other ligands and complexes prepared from different vanadium precursors under similar reaction conditions was also attempted and it was confirmed that the imine methylation observed is both ligand and metal precursor specific. Complexes 1 and 2 show in vitro insulin-like activity against insulin responsive L6 myoblast cells, with complex 1 being more potent. In addition, the in vitro cytotoxicity studies of HL, and of complexes 1 and 2 against the MCF–7 and Vero cell lines were also done. The ligand is not cytotoxic and complex 2 is significantly more cytotoxic than 1. DAPI staining experiments indicate that increase in time of incubation as well as increase of concentration of the complexes lead to increase in cell death

    AnBx - Security Protocols Design and Verification

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    Designing distributed protocols is challenging, as it requires actions at very different levels: from the choice of network-level mechanisms to protect the exchange of sensitive data, to the definition of structured interaction patterns to convey application-specific guarantees. Current security infrastructures provide very limited support for the specification of such guarantees. As a consequence, the high-level security properties of a protocol typically must often be hard-coded explicitly, in terms of low-level cryptographic notions and devices which clutter the design and undermine its scalability and robustness. To counter these problems, we propose an extended Alice & Bob notation for protocol narrations (AnBx) to be employed for a purely declarative modelling of distributed protocols. These abstractions provide a compact specification of the high-level security guarantees they convey, and help shield the design from the details of the underlying cryptographic infrastructure. We discuss an implementation of the abstractions based on a translation from the AnBx notation to the AnB language supported by the OFMC [1,2] verification tool. We show the practical effectiveness of our approach by revisiting the iKP e-payment protocols, and showing that the security goals achieved by our declarative specification outperform those offered by the original protocols

    The thromboxane receptor antagonist NTP42 promotes beneficial adaptation and preserves cardiac function in experimental models of right heart overload

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    Background: Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary artery pressure leading to right ventricular (RV) failure. While current PAH therapies improve patient outlook, they show limited benefit in attenuating RV dysfunction. Recent investigations demonstrated that the thromboxane (TX) A2 receptor (TP) antagonist NTP42 attenuates experimental PAH across key hemodynamic parameters in the lungs and heart. This study aimed to validate the efficacy of NTP42:KVA4, a novel oral formulation of NTP42 in clinical development, in preclinical models of PAH while also, critically, investigating its direct effects on RV dysfunction. Methods: The effects of NTP42:KVA4 were evaluated in the monocrotaline (MCT) and pulmonary artery banding (PAB) models of PAH and RV dysfunction, respectively, and when compared with leading standard-of-care (SOC) PAH drugs. In addition, the expression of the TP, the target for NTP42, was investigated in cardiac tissue from several other related disease models, and from subjects with PAH and dilated cardiomyopathy (DCM). Results: In the MCT-PAH model, NTP42:KVA4 alleviated disease-induced changes in cardiopulmonary hemodynamics, pulmonary vascular remodeling, inflammation, and fibrosis, to a similar or greater extent than the PAH SOCs tested. In the PAB model, NTP42:KVA4 improved RV geometries and contractility, normalized RV stiffness, and significantly increased RV ejection fraction. In both models, NTP42:KVA4 promoted beneficial RV adaptation, decreasing cellular hypertrophy, and increasing vascularization. Notably, elevated expression of the TP target was observed both in RV tissue from these and related disease models, and in clinical RV specimens of PAH and DCM. Conclusion: This study shows that, through antagonism of TP signaling, NTP42:KVA4 attenuates experimental PAH pathophysiology, not only alleviating pulmonary pathologies but also reducing RV remodeling, promoting beneficial hypertrophy, and improving cardiac function. The findings suggest a direct cardioprotective effect for NTP42:KVA4, and its potential to be a disease-modifying therapy in PAH and other cardiac conditions

    Exploring subsurface fluid flow and active dewatering along the oceanic plate boundary between Africa and Eurasia (Gloria Fault)

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    R/V Meteor cruise M162 was conducted as a systematic continuation of ongoing work dedicated to understand if and howfluid flow through crust and sedimentscontinues along transform-type plate boundaries and fracture zones away from mid-ocean ridges and continental margins. Central target was the Gloria Fault in the central Northeast Atlantic. Previous findings along the eastern continuation of the Gloria Fault revealed fault-controlled fluid advection and mud volcanism along strike-slip faults in the Horseshoe Abyssal Plain and the Gulf of Cadiz, where fluid geochemistry revealed the admixture of fluids from deeply buried oceanic crust and oldest sediments on top of it. TheGloria Fault itselfis an old, reactivated, and seismically active oceanic fracture zone. During M162 a systematic survey along the main trace of the Gloria Fault between the Azores Plateau and the Madeira-Tore Rise was carried out, including sub-bottom profiler surveys, heat flow transects, gravity corer sampling, as well as video-guided CTD and multicorer deployments. In accordance to recently recorded seismic activity along the fault, there isevidence for tectonic motion both in sub-bottom profiler records and sediment cores. Heat flow measurements revealed values significantly elevated above the background in many places, predominantly along the main fault trace and other active faults.Ina number of placesfluid geochemistry revealed enhanced diagenetic processes in the sediments, implying the potential relation to upward-directed fluid flow. In summary, cruise M162revealed the first complementary data set on heat flow and fluid geochemistry along an oceanic fault zone, which will further our understanding on themes like the alteration of oceanic lithosphere and crust-ocean element exchange

    A prospective survey in European Society of Cardiology member countries of atrial fibrillation management: baseline results of EURO bservational Research Programme Atrial Fibrillation (EORP-AF) Pilot General Registry

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    Aims: Given the advances in atrial fibrillation (AF) management and the availability of new European Society of Cardiology (ESC) guidelines, there is a need for the systematic collection of contemporary data regarding the management and treatment of AF in ESC member countries. Methods and results: We conducted a registry of consecutive in- and outpatients with AF presenting to cardiologists in nine participating ESC countries. All patients with an ECG-documented diagnosis of AF confirmed in the year prior to enrolment were eligible. We enroled a total of 3119 patients from February 2012 to March 2013, with full data on clinical subtype available for 3049 patients (40.4% female; mean age 68.8 years). Common comorbidities were hypertension, coronary disease, and heart failure. Lone AF was present in only 3.9% (122 patients). Asymptomatic AF was common, particularly among those with permanent AF. Amiodarone was the most common antiarrhythmic agent used (~20%), while beta-blockers and digoxin were the most used rate control drugs. Oral anticoagulants (OACs) were used in 80% overall, most often vitamin K antagonists (71.6%), with novel OACs being used in 8.4%. Other antithrombotics (mostly antiplatelet therapy, especially aspirin) were still used in one-third of the patients, and no antithrombotic treatment in only 4.8%. Oral anticoagulants were used in 56.4% of CHA 2DS2-VASc = 0, with 26.3% having no antithrombotic therapy. A high HAS-BLED score was not used to exclude OAC use, but there was a trend towards more aspirin use in the presence of a high HAS-BLED score. Conclusion: The EURObservational Research Programme Atrial Fibrillation (EORP-AF) Pilot Registry has provided systematic collection of contemporary data regarding the management and treatment of AF by cardiologists in ESC member countries. Oral anticoagulant use has increased, but novel OAC use was still low. Compliance with the treatment guidelines for patients with the lowest and higher stroke risk scores remains suboptimal. © The Author 2013
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