bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular divergence in tropical tree populations occupying environmental mosaics
Authors: Audigeos D. , Brousseau L. , Traissac S. , Scotti‐Saintagne C. , Scotti I. 
Published: January 2013

AbstractUnveiling the genetic basis of local adaptation to environmental variation is a major goal in molecular ecology. In rugged landscapes characterized by environmental mosaics, living populations and communities can experience steep ecological gradients over very short geographical distances. In lowland tropical forests, interspecific divergence in edaphic specialization (for seasonally flooded bottomlands and seasonally dry terra firme soils) has been proven by ecological studies on adaptive traits. Some species are nevertheless capable of covering the entire span of the gradient; intraspecific variation for adaptation to contrasting conditions may explain the distribution of such ecological generalists. We investigated whether local divergence happens at small spatial scales in two stands of Eperua falcata (Fabaceae), a widespread tree species of the Guiana Shield. We investigated Single Nucleotide Polymorphisms (SNP) and sequence divergence as well as spatial genetic structure (SGS) at four genes putatively involved in stress response and three genes with unknown function. Significant genetic differentiation was observed among sub‐populations within stands, and eight SNP loci showed patterns compatible with disruptive selection. SGS analysis showed genetic turnover along the gradients at three loci, and at least one haplotype was found to be in repulsion with one habitat. Taken together, these results suggest genetic differentiation at small spatial scale in spite of gene flow. We hypothesize that heterogeneous environments may cause molecular divergence, possibly associated to local adaptation in E. falcata.
Effects of within‐colony competition on body size asymmetries and reproductive skew in a social spider
Authors: Grinsted L. , Bilde T. 
Published: January 2013

AbstractReproductive partitioning is a key component of social organization in groups of cooperative organisms. In colonies of permanently social spiders of the genus Stegodyphus less than half of the females reproduce, while all females, including nonreproducers, perform suicidal allo‐maternal care. Some theoretical models suggest that reproductive skew is a result of contest competition within colonies, leading to size hierarchies where only the largest females become reproducers. We investigated the effect of competition on within‐group body size variation over six months in S. dumicola, by manipulating food level and colony size. We found no evidence that competition leads to increased size asymmetry within colonies, suggesting that contest competition may not be the proximate explanation for reproductive skew. Within‐colony body size variation was high already in the juvenile stage, and did not increase over the course of the experiment, suggesting that body size variation is shaped at an early stage. This might facilitate task specialization within colonies and ensure colony‐level reproductive output by early allocation of reproductive roles. We suggest that reproductive skew in social spiders may be an adaptation to sociality selected through inclusive fitness benefits of allo‐maternal care as well as colony‐level benefits maximizing colony survival and production.
Anti‐listerial and Anti‐biofilm Activities of Potential Probiotic Lactobacillus Strains Isolated from Tunisian Traditional Fermented Food
Authors: Ben Slama Rihab , Kouidhi Bochra , Zmantar Tarek , Chaieb Kamel , Bakhrouf Amina 
Published: January 2013

AbstractThree Lactobacilli were isolated from traditional Tunisian fermented food and then characterized for its ability to inhibit Listeria monocytogenes growth. Antagonistic effect of Lactobacillus plantarum on four L. monocytogenes strains was tested in soft artisanal cheese. Anti‐biofilm activity of Lactobacillus extracts was also tested.Our results demonstrate that the selected lactic acid bacteria (LAB) extract exhibited a good antibacterial effect against L. monocytogenes ATCC 19115 with low MICs values: 8.33 ± 2.1, 20 ± 1.2 and 23.33 ± 1, respectively. L. plantarum also exhibited a stronger inhibitory effect against L. monocytogenes when grown in cheese. Moreover, a potential anti‐biofilm effect of the three LAB extracts with BIC50 values ranging from 5% to 15% for L. monocytogenes ATCC 19115 was demonstrated. Although LAB extracts were able to eradicate significantly a preformed L. monocytogenes biofilm (P < 0.05). Growth inhibition of preformed biofilm was more difficult to achieve. LAB could be used as a bioprotective culture in cheese ripening to prevent Listeria growth.Practical ApplicationsA wide range of lactic acid bacteria (LAB) produce bacteriocins, which were essentially active against the food‐borne pathogen Listeria monocytogenes. 2, 3‐bis (2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐5‐[(phenylamino) carbonyl]‐2H‐tetrazolium hydroxide (XTT) reduction method was used to assess the anti‐biofilm and anti‐listerial activity of LAB extract. XTT reduction assay is dependent on the microbial respiratory activity.Since XTT is used for quantification of the microbial respiratory activity, it was used to quantify viable mature biofilm and to compare LAB activity against planktonic and biofilm cells.
Characterization of electroencephalographic and biochemical responses at 5‐HT promoting drug‐induced onset of serotonin syndrome in rats
Authors: Ma Zhiyuan , Rudacille Mary , Prentice Howard M. , Tao Rui 
Published: January 2013

AbstractMany psychotropic substances used either for medications or illicit recreational purposes are able to produce an increase in extracellular serotonin (5HT) in the CNS. 5HT is well known to improve mood; however, only when the levels of its release are in an appropriate range. Excessive 5HT is harmful, and will generally result in serotonin syndrome. To date, clinical diagnosis of serotonin syndrome relies exclusively on observation of symptoms because of a lack of available laboratory tests. The goal of this study was to characterize the onset of the syndrome using laboratory settings to determine excessive 5HT‐evoked neurological abnormalities. Experiments were carried out in rats with the syndrome being elicited by three groups of 5HT‐promoting drugs: (i) (±)‐3,4‐methylenedioxymethamphetamine (MDMA); (ii) a combination of the monoamine oxidase inhibitor clorgyline with the 5HT precursor 5‐hydroxytryptophan; (iii) clorgyline combined with the serotonin‐selective reuptake inhibitor paroxetine. The onset of the syndrome was characterized by electroencephalography (EEG), tremor, and brain/plasma 5HT tests. We found that a mild syndrome was associated with reduced EEG amplitudes while a severe syndrome strongly with seizure‐like EEG activity and increased tremor activity. The occurrence of the syndrome was confirmed with microdialysis, showing excessive 5HT efflux in brain dialysate and the increased concentration of unbound 5HT in the plasma. Our findings suggest that the syndrome onset can be revealed with EEG recording, measurements of tremor activity and changes of unbound 5HT concentration in the plasma.
Risk factors associated with outcomes of very low birthweight infants in four Asian countries
Authors: Wariki Windy Mariane Virenia , Mori Rintaro , Boo Nem‐Yun , Cheah Irene Guat Sim , Fujimura Masanori , Lee Jiun , Wong Kar Yin 
Published: January 2013

AimThe study aims to determine the risk factors associated with mortality and necrotising enterocolitis (NEC) among very low birthweight infants in 95 neonatal intensive care units in the Asian Network on Maternal and Newborn Health.MethodsThis is a cross‐sectional study using an international collaborative database of 17 595 very low birthweight infants admitted within 28 days of birth between 2003 and 2006 in four Asian countries. Information on the mortality and morbidity of neonates admitted to the neonatal intensive care units was recorded. Factors associated with the death and diseases of infants were estimated using multilevel multivariate logistic regression. Random effects were included to account for the clustering of the observations.ResultsOverall discharge mortality was 15% and it was significantly different by countries and units. The mortality rate was found to be significantly higher in neonates with pulmonary haemorrhage (odds ratio 1.83, 95% confidence interval 1.63–2.04) and air leak syndrome (odds ratio 1.51, 95% confidence interval 1.30–1.72). The incidence of NEC was 4.3% and was strongly associated with other morbidities. Multivariate logistic regression showed that patent ductus arteriosus was the most significant risk factor associated with NEC.ConclusionsOur analysis has highlighted the great potential that multi‐country, collaborative datasets have in terms of epidemiologic research when it comes to identifying issues in perinatal health that are common throughout Asia, and in relation to particular issues pertaining to specific countries and neonatal units. Establishing collaborative networks, conducting analyses of common datasets and further epidemiologic research are now essential measures to improve newborn health in Asia.
Optimal management of HBV infection during pregnancy
Authors: Piratvisuth Teerha 
Published: January 2013

AbstractChronic hepatitis B virus (HBV) infection in pregnancy presents a unique and important challenge. Over 50% of chronicHBVcarriers in endemic areas acquire infection vertically from their mothers. More importantly, over 90% of perinatally acquired infections progress to chronicHBVinfection. Thus, management of chronicHBVduring pregnancy and strategies to prevent mother‐to‐child transmission is an important step in eradicating or reducing the global burden of chronic hepatitis B. In addition, chronicHBVinfection in pregnancy presents a unique clinical challenge because of the complex relationship between the physiological changes of pregnancy and the pathophysiological response toHBV. This review will present the current knowledge and a practical approach to management ofHBVin pregnancy.
Why do I treat HBeAg‐negative chronic hepatitis B patients with pegylated interferon?
Authors: Lampertico Pietro , Viganò Mauro , Colombo Massimo 
Published: January 2013

AbstractChronic hepatitis B (CHB) in serum HBeAg negative patients is a difficult to cure, progressive disease leading to end‐stage liver disease and hepatocellular carcinoma. Currently, there are two different treatment strategies for such patients: a finite course of Pegylated interferon (PEG‐IFN) or long‐term administration of the more potent and less resistance‐prone nucleot(s)ide analogues (NUC), i.e. entecavir and tenofovir. Although NUC may ensure persistent viral suppression by preventing disease progression in most patients, they require lifelong administration with the hypothetical disadvantages of cost, lack of long‐term safety data and, most important, the null rates of HBsAg seroclearance. On the other hand, 1 year of PEG‐IFN has the advantage of providing an immune‐mediated control of hepatitis B virus (HBV) infection, with the possibility of achieving a sustained off‐treatment response in 20% of the patients, ultimately leading to HBsAg loss in approximately 50% of these. However, these sustained response rates can be significantly increased by carefully selecting candidates for PEG‐IFN therapy based upon baseline ALT and HBV DNA levels, viral genotype and IL28B polymorphisms, by extending PEG‐IFN therapy beyond 48 weeks and, most importantly, by applying early on‐treatment stopping rules based upon HBsAg kinetics. Overall, PEG‐IFN is an ideal treatment strategy in selected patients with HBeAg‐negative CHB, because of its well‐recognized and predictable safety profile and a unique mechanism of antiviral activity leading to long‐lasting immune control. Because of these features, new therapeutic trials based upon a combination of PEG‐IFN and third generation NUC such as entecavir and tenofovir, in both naïve and NUC‐exposed patients, are ongoing to further increase the rates of HBsAg seroclearance, which remains the ‘ideal end‐point’ in all HBeAg‐negative CHB subjects.
Why do I treat HBeAg‐positive chronic hepatitis B patients with a Nucleoside analogue
Authors: Ma Hong , Jia Jidong 
Published: January 2013

AbstractChronic hepatitis B (CHB) is a worldwide public health problem which represents an enormous economic and social burden. Convincing evidence has shown that persistent active viral replication is an independent predictor of disease progression. Therefore, sustained suppression of HBV replication is the cornerstone for preventing the progression of disease and prolonging survival in patients with CHB. Pivotal clinical trials and real‐world studies show that nucleos(t)ide analogues (NAs) are potent suppressors of HBV DNA replication with very good safety profiles. Although 1‐year treatment with NAs only results in a modest rate of HBeAg seroconversion, extended treatment could increase this rate. Profound suppression of HBV DNA can result in histological improvement and a clinical benefit with a decrease in disease progression in patients with compensated or decompensated cirrhosis. Treatment must be begun with a highly potent and low resistant regimen to obtain long‐term suppression of viral replication. An alternative solution may be a roadmap approach in which an inexpensive antiviral drug is started and another drug is added‐on or switched‐to if there is a suboptimal on‐treatment decrease in HBV DNA. Clinical evidence has shown that once HBV DNA is suppressed and long‐term HBeAg seroconversion is achieved, NAs can be stopped. In summary, high antiviral efficacy, excellent tolerance, extensive applicability, clearly proven histological improvement and long‐term clinical benefit all make NAs the preferred choice for the management of CHB in most patients.
How to optimize HCV therapy in genotype 1 patients with cirrhosis
Authors: Bourlière Marc , Wendt Astrid , Fontaine Hélène , Hézode Christophe , Pol Stanislas , Bronowicki Jean Pierre 
Published: January 2013

AbstractOf all hepatitis C virus patients, those with cirrhosis are most in need of treatment owing to increased morbidity and mortality. Treatment with pegylated interferon and ribavirin (PEG‐IFN/RBV) has clearly shown the benefits of successful treatment by improving fibrosis, causing the regression of cirrhosis and reducing and preventing cirrhosis‐related complications. However, the sustained virological response (SVR) is lower in patients with cirrhosis. First generation protease inhibitors (boceprevir and telaprevir) in combination with PEG‐IFN/RBV are a major advancement in the treatment of both naïve and treatment‐experienced genotype 1 patients. In naïve patients, the SVR rate with the triple regimen with boceprevir increased by 14% in patients with severe fibrosis or cirrhosis compared to PEG‐IFN/RBV compared by 30% in patients with mild or moderate fibrosis. The SVR rate of the triple regimen with telaprevir increased by 10–30% compared to PEG‐IFN/RBV in patients with severe fibrosis or cirrhosis and by nearly 30% in patients with mild or moderate fibrosis. The greatest benefits seem to be found in patients with cirrhosis who have relapsed, and is limited in prior non‐responder patients. Thus, the choice of triple therapy in the latter should be considered in relation to the increase in side effects. There are no data on the efficacy of the triple regimen in patients with decompensated cirrhosis. Results in real‐life settings show that patients with cirrhosis need to be carefully followed‐up during treatment due to the increase in side effects that are greater than in clinical studies. Next generation DAAs and PEG‐IFN/RBV appear to be more effective and have fewer side effects in patients with cirrhosis. Ultimately, an interferon‐free regimen of DAAs combinations will probably provide a SVR in patients with cirrhosis and will probably be proposed in patients with more advanced or decompensated cirrhosis.
New therapeutic strategies in HCV: polymerase inhibitors
Authors: Gerber Ludmila , Welzel Tania M. , Zeuzem Stefan 
Published: January 2013

AbstractThe characterization of the viral life cycle facilitated the development of directly acting antiviral drugs. Among those, several inhibitors of the viral RNA‐dependent RNA polymerase have proven effectiveness in clinical trials. The characteristics of different nucleos(t)ide and non‐nucleoside polymerase inhibitors, as well as their clinical applications and combinations with other classes of directly acting antiviral drugs are reviewed herein.
Optimal treatment with boceprevir for chronic HCV infection
Authors: Maasoumy Benjamin , Manns Michael P. 
Published: January 2013

AbstractThere are 160–170 million people with chronic hepatitis C virus (HCV) infection worldwide. The marketing of protease inhibitors (PIs) has been a milestone in the history of HCV therapy. In phase III studies, up to 75% of the patients achieved a sustained virological response (SVR) after triple therapy with pegylated‐interferon (PEG‐IFN)‐α, ribavirin (RBV) and boceprevir (BOC). However, triple regimens are more expensive and associated with drug–drug interactions (DDIs) and more adverse events (AEs). According to results in ‘real‐world’ settings, safety seems to be limited, in particular in patients with advanced liver disease. To optimize efficacy while minimizing AEs as well as costs, the optimal treatment strategy must be determined for BOC. Optimizing treatment is based on patient selection, the most efficient treatment design, management of side effects and the challenge of DDIs. Therapy‐associated risks, treatment urgency and chances of SVR must all be considered for patient selection. In addition, certain differences between the two approved PIs may help identify the ideal candidates for each HCV PI. Optimal treatment design is based on the results of phase II and III studies, in which different approaches have been tested including ‘lead‐in’ and response‐guided strategies. Treatment regimens and stopping rules recommended by the FDA and EMA should normally be followed. Still, there are some cases in which more personalized strategies may be more promising. Management of side effects is a major challenge and plays a crucial role in ensuring safety and adherence.
Optimal treatment with telaprevir for chronic HCV infection
Authors: Jesudian Arun B. , Jacobson Ira M. 
Published: January 2013

AbstractTelaprevir is a recently approved direct‐acting antiviral against hepatitis C virus (HCV) that works through inhibition of the NS3/4A serine protease inhibitor.Phase 2b and 3 studies have shown marked increase in sustained virological response rates in both treatment‐ naïve and treatment‐experienced patients with HCV genotype 1 treated with a telaprevir‐containing regimen compared with pegylated interferon (PEG‐IFN) and ribavirin alone. The most commonly observed side effects of telaprevir therapy are anaemia to a greater degree than that observed with PEG‐IFN/ribavirin alone; eczematous rash, which can be severe in a minority of patients; and anorectal discomfort.
HCV therapy in HIV‐infected patients
Authors: Sulkowski Mark S. 
Published: January 2013

AbstractHepatitis C virus (HCV) co‐infection is common among HIV‐infected patients. Over the past 15 years, effective HIV treatment has led to dramatic reductions in the incidence of AIDS‐related death; over the same time period, HCV‐related liver disease has emerged as a major cause of morbidity and mortality. Treatment with peginterferon (PEG‐IFN) and ribavirin (RBV) has been recommended for the treatment of HCV infection in HIV‐infected patients at the greatest risk of developing liver disease. However, the effectiveness of this HCV treatment has been low because of limited efficacy in patients infected with HCV genotype 1. More recently, HCV NS3/4A protease inhibitors, telaprevir and boceprevir, in combination with PEG‐IFN/RBV have led to significantly higher sustained viral response rates in HIV‐uninfected patients with HCV genotype 1 infection. The potential use of these agents in patients with HIV/HCV co‐infection is complicated by the potential for drug interactions between antiretroviral drugs and the HCV protease inhibitors and uncertainty regarding the safety and effectiveness of the combination therapy in this population.
Glutamine synthetase expression in activated hepatocyte progenitor cells and loss of hepatocellular expression in congestion and cirrhosis
Authors: Fleming Kirsten E. , Wanless Ian R. 
Published: January 2013

AbstractBackground & AimsIn normal human liver, glutamine synthetase (GS) is expressed in a rim of hepatocytes surrounding hepatic veins. GS expression is decreased in cirrhosis and increased in chronic hepatitis, focal nodular hyperplasia, peritumoural hyperplasia and some hepatocellular neoplasms. For the non‐neoplastic conditions, there is limited information available on histological pattern of altered GS expression and the mechanisms of these changes.MethodsWe examined GS expression in 58 large specimens and 45 needle biopsies with a variety of non‐neoplastic human liver conditions and in 12 normal control livers. Expression was correlated with clinical and histological disease states.ResultsWe identified four patterns of GS expression: (i) Loss of normal perivenular expression was seen in states of chronic congestion, severe cirrhosis and zone 3 necrosis. (ii) Diffuse expression was seen in states with active hepatocellular injury and correlated with Ki‐67 expression. (iii) Interface expression was seen in feathery degeneration of chronic cholestasis. (iv) GS expression in activated hepatocyte progenitor cells (HPCs) associated with small ducts and ductules was seen in fulminant hepatic failure and in early and late chronic liver disease and rarely in normal livers.ConclusionsGlutamine synthetase expression is increased in regenerating hepatocytes and in early HPCs prior to morphological evidence of hepatocellular differentiation. This may be the earliest marker of HPCs yet demonstrated. Loss of expression may be a reflection of disrupted endothelium‐hepatocyte contact in hepatic vein walls caused by congestive injury as found in congestive heart failure and advanced cirrhosis.
Can lightning produce significant levels of mass‐independent oxygen isotopic fractionation in nebular dust?
Authors: Nuth Joseph A. , Paquette John A. , Farquhar Adam 
Published: January 2013

AbstractBased on recent evidence that oxide grains condensed from a plasma will contain oxygen that is mass‐independently fractionated compared to the initial composition of the vapor, we present a first attempt to evaluate the potential magnitude of this effect on dust in the primitive solar nebula. This assessment relies on previous studies of nebular lightning to provide reasonable ranges of physical parameters to form a very simple model to evaluate the plausibility that lightning could affect a significant fraction of nebular dust and that such effects could cause a significant change in the oxygen isotopic composition of solids in the solar nebula over time. If only a small fraction of the accretion energy is dissipated as lightning over the volume of the inner solar nebula, then a large fraction of nebular dust will be exposed to lightning. If the temperature of such bolts is a few percent of the temperatures measured in terrestrial discharges, then dust will vaporize and recondense in an ionized environment. Finally, if only a small average decrease is assumed in the 16O content of freshly condensed dust, then over the last 5 Myr of nebular accretion the average Δ17O of the dust could increase by more than 30 per mil. We conclude that it is possible that the measured “slope 1” oxygen isotope line measured in meteorites and their components represents a time‐evolution sequence of nebular dust over the last several million years of nebular evolution where 16O‐rich materials formed first, then escaped further processing as the average isotopic composition of the dust gradually became increasingly depleted in 16O.