Interpolation Properties and SAT-based Model Checking

Craig interpolation is a widespread method in verification, with important applications such as Predicate Abstraction, CounterExample Guided Abstraction Refinement and Lazy Abstraction With Interpolants. Most state-of-the-art model checking techniques based on interpolation require collections of interpolants to satisfy particular properties, to which we refer as "collectives"; they do not hold in general for all interpolation systems and have to be established for each particular system and verification environment. Nevertheless, no systematic approach exists that correlates the individual interpolation systems and compares the necessary collectives. This paper proposes a uniform framework, which encompasses (and generalizes) the most common collectives exploited in verification. We use it for a systematic study of the collectives and of the constraints they pose on propositional interpolation systems used in SAT-based model checking

From Cheese Whey Permeate To An Anti-Listeria Food Packaging Device: Bacterial Cellulose Nanocrystals/Sakacin-A Conjugates (Nanosak)

In the present project cheese whey permeate (CWP), the residual by-product obtained by extraction of whey proteins from cheese whey, was used as substrate for the growth of bacterial species that produce two appealing molecules: the anti-listerial bacteriocin sakacin-A and bacterial cellulose (BC). BC is then turned into nanocrystals (BCNCs) that are finally conjugated with sakacin-A to obtain an innovative antimicrobial device for food which could support Listeria monocytogenes growth. Sakacin-A was produced by Lactobacillus sakei DSMZ 6333 in liquid cultures. The highest bacteriocin production (around 300 AU/mL) was achieved after 9 h at 26\ub0C; a food-grade, salt-free enriched sakacin-A extract was obtained by using a gravity reverse phase chromatography. BC was produced by Komagataeibacter xylinus DSMZ 2325 by static fermentation of CWP in presence of 0.5 U/mL of \u3b2-galactosidase at 30\ub0C; after 7 days, BC yield was around 7 g/L. BCNCs were then obtained by acid hydrolysis mediated by sulfuric acid, with the goal of removing the amorphous regions of BC and introduce a net negative charge by esterification on the hydroxyl group on C6. BCNCs/sakacin-A conjugates were prepared by exploiting their opposite charge: enriched sakacin-A extract was mixed with BCNCs and, after incubation, conjugates collected by centrifugation have a specific activity of 100 AU/mg BCNCs. Among all peptides present in the enriched sample, sakacin-A appears to preferentially absorb onto BCNCs, thus allowing its further purification. Sakacin-A as well its BCNCs conjugates were then included in a hydroxypropil-cellulose coating spread onto paper sheets at a concentration of 5 and 25 AU/cm2. The addition of the coating did not bring any significant change in the oxygen barrier properties of the cellulosic substrate. In a similar way, the static contact angle of both uncoated and coated substrate was of approximately 130\ub0. However, the presence of BCNCs seemed to increase the swelling phenomenon of the coating. Sakacin A was also included in whey, caseine and cellulose derived matrices to prepare films and coatings with diverse results. The kinetics of Sakacin-A released from active films to aqueous food was analyzed by immersion of samples in water (as simulant) and measuring the anti-Listeria activity of the simulant after increasing times of exposure. In vitro and in vivo antimicrobial trials were carried out on real food products demonstrated their anti-listerial effectiveness, proving that the developed devices can contribute to increase shelf life, quality and safety of perishable foods

Platelet inhibition with ticagrelor 60 mg versus 90 mg twice daily in the PEGASUS-TIMI 54 trial

Background The PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin–Thrombolysis In Myocardial Infarction 54) trial studied 2 doses of ticagrelor, 90 mg twice a day (bid) and 60 mg bid, for long-term prevention of ischemic events in patients with prior myocardial infarction. Both doses similarly reduced the rate of ischemic events versus placebo. The pharmacokinetics and pharmacodynamics of ticagrelor 60 mg bid have not been studied. Objectives In this study, the authors sought to study the pharmacokinetics and pharmacodynamics for ticagrelor 60 mg compared with 90 mg bid. Methods A total of 180 patients who received >4 weeks of study medication had blood sampling in the morning pre-maintenance dose and again 2 h post-dose. All patients received aspirin. Plasma levels of ticagrelor and its active metabolite AR-C124910XX were determined. P2Y12 inhibition was assessed by the VerifyNow P2Y12 assay (Accumetrics, Inc., San Diego, California) (P2Y12 reaction units [PRU]), light transmittance aggregometry (adenosine diphosphate 5 and 20 μmol/l and arachidonic acid), and vasodilator-stimulated phosphoprotein phosphorylation assays. VerifyNow Aspirin assays and serum thromboxane B2 measurements were performed. Results Mean pre- and post-dose plasma levels of ticagrelor were 35% and 38% lower, respectively, with 60 mg versus 90 mg. Both doses achieved high levels of platelet inhibition pre- and post-dose, with numerically slightly more variability with 60 mg: mean (SD) pre-dose PRU values were 59 ± 63 and 47 ± 43 for ticagrelor 60 and 90 mg, respectively (p = 0.34). High platelet reactivity, determined as PRU >208, was rare with the 60-mg pre-dose and was absent post-dose. Platelet reactivity pre- and post-dose, as measured by light transmittance aggregometry or vasodilator-stimulated phosphoprotein assays, was numerically but not significantly lower with 90 mg than with 60 mg. Aspirin response was not affected by either dose. Conclusions Ticagrelor 60 mg bid achieved high levels of peak and trough platelet inhibition in nearly all patients, similar to that with 90 mg bid, helping to explain the efficacy of the lower ticagrelor dose in PEGASUS-TIMI 54

Determination of the in vivo structural DNA loop organization in the genomic region of the rat albumin locus by means of a topological approach

Nuclear DNA of metazoans is organized in supercoiled loops anchored to a proteinaceous substructure known as the nuclear matrix (NM). DNA is anchored to the NM by non-coding sequences known as matrix attachment regions (MARs). There are no consensus sequences for identification of MARs and not all potential MARs are actually bound to the NM constituting loop attachment regions (LARs). Fundamental processes of nuclear physiology occur at macromolecular complexes organized on the NM; thus, the topological organization of DNA loops must be important. Here, we describe a general method for determining the structural DNA loop organization in any large genomic region with a known sequence. The method exploits the topological properties of loop DNA attached to the NM and elementary topological principles such as that points in a deformable string (DNA) can be positionally mapped relative to a position-reference invariant (NM), and from such mapping, the configuration of the string in third dimension can be deduced. Therefore, it is possible to determine the specific DNA loop configuration without previous characterization of the LARs involved. We determined in hepatocytes and B-lymphocytes of the rat the DNA loop organization of a genomic region that contains four members of the albumin gene family

Multi-site investigation of strategies for the implementation of CYP2C19 genotype-guided antiplatelet therapy

CYP2C19 genotype-guided antiplatelet therapy following percutaneous coronary intervention is increasingly implemented in clinical practice. However, challenges such as selecting a testing platform, communicating test results, building clinical decision support processes, providing patient and provider education, and integrating methods to support the translation of emerging evidence to clinical practice are barriers to broad adoption. In this report, we compare and contrast implementation strategies of 12 early adopters, describing solutions to common problems and initial performance metrics for each program. Key differences between programs included the test result turnaround time and timing of therapy changes which are both related to CYP2C19 testing model and platform used. Sites reported the need for new informatics infrastructure, expert clinicians such as pharmacists to interpret results, physician champions, and ongoing education. Consensus lessons learned are presented to provide a path forward for those seeking to implement similar clinical pharmacogenomics programs within their institutions. This article is protected by copyright

Consistent platelet inhibition with ticagrelor 60 mg twice-daily following myocardial infarction regardless of diabetes status

SummaryDiabetes increases cardiovascular risk and reduces pharmacodynamic response to some oral antiplatelet drugs. This study aimed to determine whether ticagrelor 60 mg twice daily (bid) provided potent and consistent platelet inhibition in patients with vs without diabetes in the PEGASUS-TIMI 54 platelet function substudy. Out of 180 patients studied, 58 patients were randomised to and had received at least four weeks of ticagrelor 60 mg bid, with 20 (34 %) having diabetes, 58 patients received ticagrelor 90 mg bid, with 12 (21 %) having diabetes, and 64 patients received placebo, with 18 (28 %) having diabetes. Blood was sampled pre- and 2 hours post-maintenance dose. In patients treated with ticagrelor 60 mg bid, on-treatment platelet reactivity to ADP, as determined by light transmission aggregometry (LTA), VerifyNow and VASP, was similar in patients with vs without diabetes (LTA post-dose, ADP 20 ?M: 29 ± 14 vs 34 ± 10 %, respectively; p = 0.19). A consistent inhibitory effect of ticagrelor 60 mg bid was observed pre- and post-dose regardless of diabetes status, even in insulin-treated patients. Patients with diabetes did not have an increased incidence of high platelet reactivity in either ticagrelor group. Platelet reactivity was similar in patients with diabetes treated with ticagrelor 60 mg vs 90 mg bid. Pharmacokinetics of ticagrelor were not affected by diabetes status. In conclusion, ticagrelor 60 mg bid is equally effective at reducing platelet reactivity in patients with and without diabetes, yielding a consistently high level of platelet inhibition regardless of diabetes status.</jats:p

Lipid rafts are essential for release of phosphatidylserine-exposing extracellular vesicles from platelets.

Platelets protect the vascular system during damage or inflammation, but platelet activation can result in pathological thrombosis. Activated platelets release a variety of extracellular vesicles (EVs). EVs shed from the plasma membrane often expose phosphatidylserine (PS). These EVs are pro-thrombotic and increased in number in many cardiovascular and metabolic diseases. The mechanisms by which PS-exposing EVs are shed from activated platelets are not well characterised. Cholesterol-rich lipid rafts provide a platform for coordinating signalling through receptors and Ca2+ channels in platelets. We show that cholesterol depletion with methyl-β-cyclodextrin or sequestration with filipin prevented the Ca2+-triggered release of PS-exposing EVs. Although calpain activity was required for release of PS-exposing, calpain-dependent cleavage of talin was not affected by cholesterol depletion. P2Y12 and TPα, receptors for ADP and thromboxane A2, respectively, have been reported to be in platelet lipid rafts. However, the P2Y12 antagonist, AR-C69931MX, or the cyclooxygenase inhibitor, aspirin, had no effect on A23187-induced release of PS-exposing EVs. Together, these data show that lipid rafts are required for release of PS-exposing EVs from platelets.Isaac Newton Trust/ Wellcome Trust ISSF/University of Cambridge Joint Research Grant British Heart Foundation grant SP/15/7/3156

Hypofibrinolysis in diabetes: a therapeutic target for the reduction of cardiovascular risk

An enhanced thrombotic environment and premature atherosclerosis are key factors for the increased cardiovascular risk in diabetes. The occlusive vascular thrombus, formed secondary to interactions between platelets and coagulation proteins, is composed of a skeleton of fibrin fibres with cellular elements embedded in this network. Diabetes is characterised by quantitative and qualitative changes in coagulation proteins, which collectively increase resistance to fibrinolysis, consequently augmenting thrombosis risk. Current long-term therapies to prevent arterial occlusion in diabetes are focussed on anti-platelet agents, a strategy that fails to address the contribution of coagulation proteins to the enhanced thrombotic milieu. Moreover, antiplatelet treatment is associated with bleeding complications, particularly with newer agents and more aggressive combination therapies, questioning the safety of this approach. Therefore, to safely control thrombosis risk in diabetes, an alternative approach is required with the fibrin network representing a credible therapeutic target. In the current review, we address diabetes-specific mechanistic pathways responsible for hypofibrinolysis including the role of clot structure, defects in the fibrinolytic system and increased incorporation of anti-fibrinolytic proteins into the clot. Future anti-thrombotic therapeutic options are discussed with special emphasis on the potential advantages of modulating incorporation of the anti-fibrinolytic proteins into fibrin networks. This latter approach carries theoretical advantages, including specificity for diabetes, ability to target a particular protein with a possible favourable risk of bleeding. The development of alternative treatment strategies to better control residual thrombosis risk in diabetes will help to reduce vascular events, which remain the main cause of mortality in this condition