68 research outputs found

    The molecular pharmacology and in vivo activity of 2-(4-chloro-6-(2,3-dimethylphenylamino)pyrimidin-2-ylthio)octanoic acid (YS121), a dual inhibitor of microsomal prostaglandin E2 synthase-1 and 5-lipoxygenase.

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    The microsomal prostaglandin E2 synthase (mPGES)-1 is one of the terminal isoenzymes of prostaglandin (PG) E2 biosynthesis. Pharmacological inhibitors of mPGES-1 are proposed as an alternative to nonsteroidal anti-inflammatory drugs. We recently presented the design and synthesis of a series of pirinixic acid derivatives that dually inhibit mPGES-1 and 5-lipoxygenase. Here, we investigated the mechanism of mPGES-1 inhibition, the selectivity profile, and the in vivo activity of α-(n-hexyl)- substituted pirinixic acid [YS121; 2-(4-chloro-6-(2,3-dimethylphenylamino) pyrimidin-2-ylthio)octanoic acid)] as a lead compound. In cell-free assays, YS121 inhibited human mPGES-1 in a reversible and noncompetitive manner (IC 50 = 3.4 μM), and surface plasmon resonance spectroscopy studies using purified in vitro-translated human mPGES-1 indicate direct, reversible, and specific binding to mPGES-1 (KD = 10-14 μM). In lipopolysaccharide-stimulated human whole blood, PGE2 formation was concentration dependently inhibited (IC50 =2 μM), whereas concomitant generation of the cyclooxygenase (COX)-2-derived thromboxane B2 and 6-keto PGF1α and the COX-1-derived 12(S)-hydroxy-5-cis-8,10- transheptadecatrienoic acid was not significantly reduced. In carrageenan-induced rat pleurisy, YS121 (1.5 mg/kg i.p.) blocked exudate formation and leukocyte infiltration accompanied by reduced pleural levels of PGE2 and leukotriene B4 but also of 6-keto PGF 1α. Taken together, these results indicate that YS121 is a promising inhibitor of mPGES-1 with anti-inflammatory efficiency in human whole blood as well as in vivo

    Semi-automatic conversion of BioProp semantic annotation to PASBio annotation

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    <p>Abstract</p> <p>Background</p> <p>Semantic role labeling (SRL) is an important text analysis technique. In SRL, sentences are represented by one or more predicate-argument structures (PAS). Each PAS is composed of a predicate (verb) and several arguments (noun phrases, adverbial phrases, etc.) with different semantic roles, including main arguments (agent or patient) as well as adjunct arguments (time, manner, or location). PropBank is the most widely used PAS corpus and annotation format in the newswire domain. In the biomedical field, however, more detailed and restrictive PAS annotation formats such as PASBio are popular. Unfortunately, due to the lack of an annotated PASBio corpus, no publicly available machine-learning (ML) based SRL systems based on PASBio have been developed. In previous work, we constructed a biomedical corpus based on the PropBank standard called BioProp, on which we developed an ML-based SRL system, BIOSMILE. In this paper, we aim to build a system to convert BIOSMILE's BioProp annotation output to PASBio annotation. Our system consists of BIOSMILE in combination with a BioProp-PASBio rule-based converter, and an additional semi-automatic rule generator.</p> <p>Results</p> <p>Our first experiment evaluated our rule-based converter's performance independently from BIOSMILE performance. The converter achieved an F-score of 85.29%. The second experiment evaluated combined system (BIOSMILE + rule-based converter). The system achieved an F-score of 69.08% for PASBio's 29 verbs.</p> <p>Conclusion</p> <p>Our approach allows PAS conversion between BioProp and PASBio annotation using BIOSMILE alongside our newly developed semi-automatic rule generator and rule-based converter. Our system can match the performance of other state-of-the-art domain-specific ML-based SRL systems and can be easily customized for PASBio application development.</p

    Cooperative Investment, Access, and Uncertainty

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    This paper compares the impacts of traditional one–way access obligations and the new regulatory scheme of co-investment on the roll-out of network infrastructures. We show that compulsory access leads to smaller roll-out, first because it reduces the returns from investment, and second because in the presence of uncertainty it provides access seekers with an option whose exercise hurts investors. Co-investment without access obligations leads to risk sharing and eliminates the access option, implying highest network coverage. Allowing for access on top of co-investment actually decreases welfare if the access price is low

    The editorial-Regulation and competition in communications markets

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    The special issue of Telecommunications Policy contains a series of papers presented at the first Scientific Seminar of the Communications and Media area of the Florence School of Regulation. All deal with hotly debated topics in evolving communications markets. Three main issues are considered: firstly, the regulation of mobile call termination and its effects on pricing strategies and competition; secondly, the development of broadband and ultra-broadband networks and the supply-side and demand-side policies intended to spur companies’ investment into an infrastructure that is expected to be fundamental for future communications markets and the growth of the whole economy; thirdly, in relation to media markets, this issue presents papers analysing how advertisement on different media such as commercial TV paid or free newspapers, blogs, radio, might be used to affect competition among firms in their respective product markets

    Fixed-Mobile Integration

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    Often, fixed-line incumbents also own the largest mobile network. We consider the effect of this joint ownership on market outcomes. Our model predicts that while fixed-to-mobile call prices to the integrated mobile network are more efficient than under separation, those to rival mobile networks are distorted upwards, amplifying any incumbency advantage. As concerns potential remedies, a uniform off-net pricing constraint leads to higher welfare than functional separation and even allows to maintain some of the efficiency gains
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