bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of prothrombin complex concentrates in reversing warfarin anticoagulation: A review of the literature
Authors: Leissinger Cindy A. , Blatt Philip M. , Hoots W. Keith , Ewenstein Bruce 
Published: August 2007

AbstractOver‐anticoagulation is a common problem with warfarin therapy and can lead to major or life‐threatening bleeding. The goal of urgent warfarin reversal is to elevate or replace vitamin K‐dependent clotting factors. In the United States, fresh frozen plasma (FFP) is considered the standard of care for warfarin reversal. Prothrombin complex concentrates (PCCs) offer an alternative to FFP for rapidly replacing deficient clotting factors and correcting the international normalized ratio (INR). However, few prospective clinical trials have been conducted to evaluate the effectiveness of these concentrates relative to other treatment modalities. A review of the published literature over the last 30 years found that PCCs offer a rapid and specific method for replacing vitamin K‐dependent clotting factors and restoring normal hemostasis in the context of over‐coagulation. In those studies in which PCCs were compared with FFP, PCCs were found more effective in shortening the time to INR correction and were associated with a low risk of thrombotic adverse events. Evidence‐based treatment guidelines are needed to optimize the use of PCCs for warfarin reversal. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Block copolymers of N‐vinyl carbazole and α,ω‐dihydroxy polydimethylsiloxane
Authors: Akar Ahmet , Kizilcan Nilgun , Ustamehmetoglu Belkis , Colak Demet , Sarac A. Sezai , Colak Cengiz 
Published: August 2007

AbstractThe redox system of ceric ammonium nitrate (Ce4+) and α,ω‐dihydroxy polydimethylsiloxane (DH.PDMS) was used to polymerize N‐vinyl carbazole (NVCz) to produce poly(N‐vinylcarbazole)‐b‐α,ω‐dihydroxy polydimethylsiloxane(PNVCz‐b‐DH.PDMS). The ratio of NVCz/ceric salt/DH.PDMS has an important effect on the properties of formed copolymers. White insulating PNVCz‐b‐PDMS copolymers with high fluorescence intensity are produced if the ratio of ceric salt/ NVCz is below 0.2. Green conductive PNVCz‐b‐PDMS copolymers are produced if this ratio is well above 0.2. The concentration and the type of DH.PDMS affected the polymerization yield. PNVCz‐b‐DH.PDMS copolymers were also prepared by electroinduced polymerization in the presence of catalytic amount of Ce4+ in a divided electrochemical cell where Ce3+ is readily oxidized to Ce4+ at the anode. White insulating PNVCz‐b‐DH.PDMS copolymers show higher contact angle value and lower Tg values than of white poly(N‐vinyl carbazole) (PNVCz). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Mechanical and morphological study of polyphenylene sulfide/liquid crystalline polymer blends compatibilized with a maleic anhydride grafted copolymer
Authors: Rath T. , Kumar S. , Mahaling R. N. , Das C. K. , Yadaw S. B. 
Published: August 2007

AbstractBlends of thermotropic liquid crystalline polymer (LCPA‐950), based on a copolyester of hydroxynapthoic acid and hydroxybenzoic acid with an engineering thermoplastic, poly(phenylene sulfide) (PPS), were prepared using a corotating twin‐screw extruder. Addition of a third component, a functionalized polypropylene (maleic anhydride grafted polypropylene, MA‐PP), that interact with the thermotropic liquid crystalline polymer (TLCP) facilitates the structural development of the TLCP phase by acting as a compatibilizer at the interface. Differential scanning calorimetry and dynamic mechanical thermal analysis results, however, show that there is an interaction between the polymers in the presence of compatibilizer. This means that MA‐PP can be used as a compatibilizer for the PPS/LCP in situ composite system. The viscosity of the compatibilized in situ composite was decreased by the compatibilizer, and this is mainly due to the fibrous structure of the LCP at the high shear rate. The mechanical properties of the ternary blends were increased when a proper amount of MA‐PP was added. This is attributed to fine fibril generation induced by the addition of MA‐PP. Morphological observations determined the significance of the third component in immiscible polymer blends, and an optimum amount of MA‐PP exists for the best mechanical performance. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Compositional trend analysis on poly(phenylene ether) based thermoplastic elastomers
Authors: Gupta Samik , Krishnamurthy Raja , Biswas Amit , Bhowmick Anil K. 
Published: August 2007

AbstractDetailed statistical trend analysis of thermoplastic elastomers based on poly (phenylene ether) (PPE), polystyrene (PS), ethylene vinyl acetate (EVA) and styrene‐ethylene‐butylene‐styrene (SEBS) was done through Design Expert software by Stat‐Ease. D optimal crossed design was followed to capture the interaction with the parameters. Effect of blend ratio, vinyl acetate (VA) content of EVA, molecular weight (MW) of SEBS and intrinsic viscosity (IV) of PPE on the blend performance (response) was studied in detail. Design of Experiment (DOE) analysis showed the “optimized formulation” of the blend. Increase in PPE‐polystyrene (PS) content increased tensile strength and modulus of the blend, followed by a decrease in strain at break. However, EVA had a reverse effect on tensile strength and modulus. Strain at break increased significantly with increasing SEBS content in the blend. Graphical and numerical optimization showed that superior mechanical properties (tensile strength, strain at break and modulus) could be achieved at VA content ∼ 50% at a particular loading of EVA. Low MW SEBS was found to be more compatible with the other components of the blend. Mechanical properties of the quaternary blend were marginally affected with change in IV of PPE in the range of 0.33 to 0.46. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Kinetics of the copolymerization of alkylene oxides with glycidyl methacrylate
Authors: Ahmetli Gulnare , Kocak Ahmet , Yazicigil Zafer 
Published: August 2007

AbstractIn the present study, the kinetics of copolymerization reaction of propylene oxide (PO) and butylene oxide (BO) with glycidyl methacrylate (GMA) in the presence of BF3·O(C2H5)2 catalyst were investigated. The kinetic parameters and activation energy of the copolymerization reaction were calculated. The amounts of reacting PO, BO, and GMA during copolymerization were determined by chromatographic method, because the same copolymerization conditions were carried out for them. It was determined that the copolymerization rate of PO (r0) and BO (r0) was higher than that of GMA, but activation energy (E) of GMA was higher than that of PO and BO. The rate of reaction, the rate constant, and activation energy were calculated from the amount of copolymer obtained with respect to time. The structures of synthesized copolymers were determined by the spectral and chemical analysis methods. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Estimating required habitat size for fish conservation in streams
Authors: Cowley David E. 
Published: August 2007

Abstract
A procedure is described to estimate viable population size and the area of habitat needed to support an endangered stream fish population. Monte Carlo simulations were used to evaluate population fates with stochastic demography and random variation simulated to cause age class 0 failures in some years. Viable population was defined in this paper to be large enough to have less than a 10% chance of extinction in 100 years and to have a long‐term effective size of at least 500 breeding adults, although the method could be applied for any assumed extinction rate and effective size.
Using data for Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis) in an age class model, it was inferred from simulations that minimum viable population size was 2750 fish, which would require 2.2 ha of habitat at median density of the subspecies in New Mexico streams.
Minimum viable population size occurred at the highest survival rate of young of year and no population‐wide year class failures. Viable population size, and hence required habitat size, increased as the failure rate for age class 0 increased or when the survival rate from age 0 to 1 declined. This suggested that managers should avoid managing for smallest possible viable population size and instead plan for much larger population sizes to accommodate temporal variation in demography and habitat quality.
Decreased survival rate of young of year caused the stable age class distribution to be skewed toward the age class 0, which profoundly reduced effective population size. This suggested that habitat restoration that improves survival of young of year would be a good strategy to increase effective size over the long term.
Estimating required habitat size could improve introductions of fish to create new populations. Although requiring time‐consuming simulations, the procedure can be used to estimate required habitat size for any species for which population and demographic data are available.
Copyright © 2007 John Wiley & Sons, Ltd.
Serious infection following anti–tumor necrosis factor α therapy in patients with rheumatoid arthritis: Lessons from interpreting data from observational studies
Authors: Dixon W. G. , Symmons D. P. M. , Lunt M. , Watson K. D. , Hyrich K. L. , Silman A. J. 
Published: August 2007

AbstractObjectiveIn a recent observational study, we found that the risk of serious infection following anti–tumor necrosis factor α (anti‐TNFα) therapy in patients with rheumatoid arthritis (RA) was not importantly increased compared with the background risk in routinely treated RA patients with similar disease severity. Observational data sets are, however, subject to a number of important biases related to selection factors for the timing of starting and stopping therapy. Infection risk is also likely to vary with duration of therapy. This study was undertaken to examine the influences of these biases and of the method of analysis on the risk of infection.MethodsWe compared the risk of serious infection in 8,659 patients treated with anti‐TNFα with that in 2,170 patients treated with traditional disease‐modifying antirheumatic drugs (DMARDs) recruited to the British Society for Rheumatology Biologics Register. We applied a number of statistical models in which we varied the length of the followup period by using different definitions of the date of discontinuation of treatment and different lag periods of risk following drug cessation.ResultsWhen the at‐risk period was defined as “receiving treatment”, the adjusted incidence rate ratio comparing patients receiving anti‐TNFα therapy with patients receiving DMARD therapy was 1.22 (95% confidence interval [95% CI] 0.88–1.69). Limiting followup to the first 90 days, however, revealed an adjusted incidence rate ratio of 4.6 (95% CI 1.8–11.9). Rates of infection were increased in the 90 days immediately following drug discontinuation and beyond, explained by selection factors for drug discontinuation.ConclusionThese findings show that overall, the way in which UK rheumatologists select patients for starting and discontinuing anti‐TNFα therapy explains our previous finding of no increase in risk. However, there may be important increases in true risk, notably early in the course of treatment, that would become more evident depending on the definition of at‐risk period.
Reduction in the incidence of myocardial infarction in patients with rheumatoid arthritis who respond to anti–tumor necrosis factor α therapy: Results from the British Society for Rheumatology Biologics Register
Authors: Dixon W. G. , Watson K. D. , Lunt M. , Hyrich K. L. , Silman A. J. , Symmons D. P. M. 
Published: August 2007

AbstractObjectiveRheumatoid arthritis (RA) is associated with an increased risk of coronary artery disease, possibly acting via shared mechanisms of inflammation. This study was undertaken to test the hypothesis that the powerful antiinflammatory effect of anti–tumor necrosis α (anti‐TNFα) therapy might lead to a reduction in the incidence of myocardial infarction (MI) in patients with RA.MethodsUsing data from the British Society for Rheumatology Biologics Register, a national prospective observational study, we compared MI rates in 8,670 patients with RA treated with anti‐TNFα and 2,170 patients with active RA treated with traditional disease‐modifying antirheumatic drugs (DMARDs).ResultsThrough July 2006, 63 MIs occurred in the anti‐TNFα cohort during 13,233 person‐years of followup and 17 MIs occurred in the DMARD cohort during 2,893 person‐years of followup, equivalent to a rate of 4.8 events per 1,000 person‐years and 5.9 events per 1,000 person‐years, respectively. After adjustment for baseline risk factors, there was no reduction in the rate of MI in the anti‐TNFα cohort compared with the DMARD cohort (incidence rate ratio 1.44 [95% confidence interval 0.56–3.67]). In an analysis of anti‐TNFα–treated patients who responded to the treatment within 6 months versus those who did not, MI rates were found to be 3.5 events per 1,000 person‐years in responders and 9.4 events per 1,000 person‐years in nonresponders. The adjusted incidence rate ratio (95% confidence interval) for responders compared with nonresponders was 0.36 (0.19–0.69).ConclusionThese results indicate that RA patients treated with anti‐TNFα do not have a lower incidence of MI compared with RA patients treated with traditional DMARDs. However, the risk of MI is markedly reduced in those who respond to anti‐TNFα therapy by 6 months compared with nonresponders. This finding supports the notion that inflammation plays a pivotal role in MI.
Low molecular weight isoforms of the aggrecanases are responsible for the cytokine‐induced proteolysis of aggrecan in a porcine chondrocyte culture system
Authors: Powell Alison J. , Little Christopher B. , Hughes Clare E. 
Published: August 2007

AbstractObjectiveThe major proteases responsible for aggrecan turnover in articular cartilage are the aggrecanases (ADAMTS‐4 and ADAMTS‐5). Although several studies have demonstrated C‐terminal truncation of these aggrecanases, the mechanism and importance of this processing are poorly understood. The objective of this study was to further investigate ADAMTS‐4 and ADAMTS‐5 C‐terminal truncation in a porcine model in vitro culture system.MethodsChondrocyte–agarose cultures with well‐established extracellular matrices were treated with or without interleukin‐1 (IL‐1), for a variety of different culture time periods. Cultures were analyzed for release of sulfated glycosaminoglycan, aggrecanase‐generated interglobular domain (IGD)–aggrecan cleavage, and the presence of ADAMTS‐4 and ADAMTS‐5 isoforms. Inhibition of aggrecanase activity with monoclonal antibodies, tissue inhibitor of metalloproteinases 3 (TIMP‐3), and cycloheximide pretreatment were used to identify ADAMTS isoforms involved in IGD–aggrecan catabolism.ResultsMultiple isoforms, including possible zymogens, of ADAMTS‐4 and ADAMTS‐5 were sequestered within the extracellular matrix formed by 3‐week chondrocyte–agarose cultures. IL‐1 exposure induced production of a low molecular weight (37 kd) isoform of ADAMTS‐4. This isoform was capable of degrading exogenous aggrecan at the IGD–aggrecanase site, was inhibited by TIMP‐3, was blocked after preincubation with an antibody to a sequence in the catalytic domain of ADAMTS‐4, and required de novo synthesis in the presence of IL‐1 for its generation.ConclusionIn porcine chondrocyte–agarose cultures, a 37‐kd ADAMTS‐4 isoform appears to be the major matrix protease responsible for the IGD–aggrecanase activity detected in response to exposure to IL‐1. This conclusion contradicts that of recent studies of transgenic knockout mice and highlights the need to determine the roles of the different aggrecanase(s) in human disease.
Protein isoprenylation regulates secretion of matrix metalloproteinase 1 from rheumatoid synovial fibroblasts: Effects of statins and farnesyl and geranylgeranyl transferase inhibitors
Authors: Abeles Aryeh M. , Marjanovic Nada , Park Jean , Attur Mukundan , Chan Edwin S. , Al‐Mussawir Hayf E. , Dave Mandar , Fisher Mark C. , Stuchin Steven A. , Abramson Steven B. , Pillinger Michael H. 
Published: August 2007

AbstractObjectiveTo determine whether protein prenylation (farnesyl/geranylgeranylation) regulates matrix metalloproteinase (MMP) secretion from rheumatoid arthritis (RA) synovial fibroblasts (RASFs), and whether MMP‐1 secretion can be regulated by statins or prenyltransferase inhibitors via effects mediated by ERK, JNK, and NF‐κB.MethodsRASFs obtained from patients during elective knee replacement surgery were assessed by immunoblotting and/or enzyme‐linked immunosorbent assay for secretion of MMP‐1 and MMP‐13 in the presence of tumor necrosis factor α (TNFα), interleukin‐1β (IL‐1β), statins, the farnesyl transferase (FT) inhibitor FTI‐276 and geranylgeranyl transferase inhibitor GGTI‐298, and prenyl substrates (farnesyl pyrophosphate [FPP] and geranylgeranyl pyrophosphate [GGPP]). Activities of JNK and ERK were determined by phosphoimmunoblotting, and NF‐κB activation was determined by nuclear translocation of the p65 component.ResultsFTI‐276, but not statins, inhibited RASF secretion of MMP‐1, but not MMP‐13, following induction with TNFα (P = 0.0007) or IL‐1β (P = 0.006). Loading RASFs with FPP to promote farnesylation enhanced MMP‐1 secretion. FTI‐276 inhibited activation of JNK (P < 0.05) and NF‐κB (P = 0.02), but not ERK. In contrast, GGTI‐298 enhanced, while GGPP inhibited, MMP‐1 secretion. FTI‐276 and GGTI‐298 together had no effect on MMP‐1 secretion. Stimulation of RASFs with TNFα or IL‐1β led to increased expression and activity of FT.ConclusionProtein farnesylation is required for expression and secretion of MMP‐1 from RASFs, via effects on JNK and NF‐κB. The ability of cytokines to stimulate the expression and activity of FT suggests that FT may be increased in the rheumatoid joint. In contrast, geranylgeranylation down‐regulates MMP‐1 expression. Statins simultaneously inhibit farnesylation and geranylgeranylation, and in consequence do not inhibit MMP‐1 secretion. The ability of FTI‐276 to inhibit MMP‐1 secretion suggests a potential therapeutic strategy in RA.
Pre–B cell colony‐enhancing factor/visfatin, a new marker of inflammation in rheumatoid arthritis with proinflammatory and matrix‐degrading activities
Authors: Brentano Fabia , Schorr Olivier , Ospelt Caroline , Stanczyk Joanna , Gay Renate E. , Gay Steffen , Kyburz Diego 
Published: August 2007

AbstractObjectiveTo study possible mechanisms that mediate induction of the recently described adipocytokine pre–B cell colony‐enhancing factor (PBEF) in joints of patients with rheumatoid arthritis (RA), and to analyze whether levels of PBEF correlate with disease severity and whether PBEF itself has the potential to act as a proinflammatory and destructive mediator in RA.MethodsRA synovial fibroblasts (RASFs) and monocytes were stimulated with Toll‐like receptor (TLR) ligands, cytokines, and recombinant human PBEF or were transfected with PBEF expression constructs or with PBEF‐specific small interfering RNA. Production of interleukin‐6 (IL‐6), IL‐8, and tumor necrosis factor α (TNFα) was measured by enzyme‐linked immunosorbent assay, and expression of matrix metalloproteinases (MMPs) was assessed by real‐time polymerase chain reaction. PBEF expression in synovial tissue, synovial fluid, serum, and SFs was assessed by immunohistochemistry, in situ hybridization, Western blotting, and enzyme immunoassays.ResultsIn RASFs, PBEF was up‐regulated by TLR ligands and cytokines that are characteristically present in the joints of patients with RA. In synovial tissue, RASFs were the major PBEF‐expressing cells. A predominance of PBEF was found in the synovial lining layer and at sites of invasion into cartilage. Levels of PBEF in serum and synovial fluid correlated with the degree of inflammation and clinical disease activity. Moreover, PBEF itself activated the transcription factors NF‐kB and activator protein 1 and induced IL‐6, IL‐8, MMP‐1, and MMP‐3 in RASFs as well as IL‐6 and TNFα in monocytes. PBEF knockdown in RASFs significantly inhibited basal and TLR ligand–induced production of IL‐6, IL‐8, MMP‐1, and MMP‐3.ConclusionOur findings establish PBEF as a proinflammatory and destructive mediator of joint inflammation in RA and identify PBEF as a potential therapeutic target.
Adapted versions of the Sharp/van der Heijde score are reliable and valid for assessment of radiographic progression in juvenile idiopathic arthritis
Authors: Ravelli Angelo , Ioseliani Maka , Norambuena Ximena , Sato Juliana , Pistorio Angela , Rossi Federica , Ruperto Nicolino , Magni‐Manzoni Silvia , Ullmann Nicola , Martini Alberto 
Published: August 2007

AbstractObjectiveTo develop adapted versions of the Sharp/van der Heijde radiographic scoring system for use in juvenile idiopathic arthritis (JIA), and to investigate their validity in JIA patients with polyarticular disease.MethodsThe study group comprised 177 patients with polyarticular JIA. Radiographs of the wrist/hand of each patient were obtained at baseline (first observation) and then at 1, 3, 5, 7/8, and 10 years and were assessed independently by 2 pediatric rheumatologists according to different adaptations of the Sharp/van der Heijde method. To facilitate score assignment, the radiograph for each patient was compared with a bone age–related standard. Validation procedures included analysis of reliability, construct validity, and score progression over time.ResultsInterobserver and intraobserver agreement on longitudinal score values and score changes was good for all of the adapted scoring versions (intraclass correlation coefficient >0.85). Score changes over time were moderately to strongly correlated with the clinical indicators of long‐term joint damage and with the amount of long‐term radiographic damage as measured with the carpo:metacarpal ratio, thereby demonstrating good construct validity. A steady increase in scores over time was observed, with joint space narrowing being the most common form of damage throughout the disease course. The inclusion of 5 new areas appeared to increase the overall construct validity of erosion scores.ConclusionOur results show that the adapted versions of the Sharp/van der Heijde score are reliable and valid for the assessment of radiographic progression in patients with JIA.