bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and characterization of a novel cold-adapted esterase from a metagenomic library of mountain soil
Authors: Ko Kyong-Cheol , Rim Soon-Ok , Han Yunjon , Shin Bong Seok , Kim Geun-Joong , Choi Jong Hyun , Song Jae Jun 
Published: January 2012

Abstract
A novel lipolytic enzyme was isolated from a metagenomic library after demonstration of lipolytic activity on an LB agar plate containing 1% (w/v) tributyrin. A novel esterase gene (estIM1), encoding a lipolytic enzyme (EstIM1), was cloned using a shotgun method from a pFosEstIM1 clone of the metagenomic library, and the enzyme was characterized. The estIM1 gene had an open reading frame (ORF) of 936 base pairs and encoded a protein of 311 amino acids with a molecular mass 34 kDa and a pI value of 4.32. The deduced amino acid sequence was 62% identical to that of an esterase from an uncultured bacterium (ABQ11271). The amino acid sequence indicated that EstIM1 was a member of the family IV of lipolytic enzymes, all of which contain a GDSAG motif shared with similar enzymes of lactic acid microorganisms. EstIM1 was active over a temperature range of 1–50°C, at alkaline pH. The activation energy for hydrolysis of p-nitrophenyl propionate was 1.04 kcal/mol, within a temperature range of 1–40°C. The activity of EstIM1 was about 60% of maximal even at 1°C, suggesting that EstIM1 is efficiently cold-adapted. Further characterization of this cold-adapted enzyme indicated that the esterase may be very valuable in industrial applications.
Effect of competition on habitat utilization in two temperate climate gecko species
Authors: Lisičić Duje , Drakulić Sanja , Herrel Anthony , Đikić Domagoj , Benković Vesna , Tadić Zoran 
Published: January 2012

AbstractCompetition over spatial niche utilisation is one of most common competitive interactions between species in sympatry. Moreover, competitive interactions may involve age classes, and can fluctuate temporally. Consequently, evasive strategies that enable co‐existence are likely to be important in the evolution of species assemblages. Here we investigate a system of two co‐existing species of temperate geckos with similar ecologies (the house gecko, Hemidactylus turcicus and the wall gecko, Tarentola mauritanica), providing an opportunity to study the effect of species interactions. Juveniles and adults of both species were investigated throughout their daily and annual cycle to explore the effect of inter‐ and intra‐specific interactions on microhabitat use. The two species showed differences in habitat use for both age classes in sympatry. In sympatry, T. mauritanica uses more open habitats and is more active. In contrast, H. turcicus is found in more closed habitats, closer to the ground and to vegetation cover. In allopatry, H. turcicus was observed in more open habitats, closer to the ground, and to vegetation cover, when compared to the population in sympatry with T. mauritanica. These differences in habitat usage were significant for both age classes. Moreover, there were differences, both in sympatry and in allopatry, between age classes that were dependent on season. In conclusion, the presence of a competitor induces a spatial shift in individuals of both age classes of H. turcicus. Observed plasticity in habitat utilisation in both age classes of H. turcicus is used to argue for the invasive potential of this species.
Enhancement of Intestinal Permeability Utilizing Solid Lipid Nanoparticles Increases γ‐Tocotrienol Oral Bioavailability
Authors: Abuasal Bilal S. , Lucas Courtney , Peyton Breanne , Alayoubi Alaadin , Nazzal Sami , Sylvester Paul W. , Kaddoumi Amal 
Published: January 2012

Abstractγ‐Tocotrienol (γ‐T3), a member of the vitamin E family, has been reported to possess an anticancer activity. γ‐T3 is a lipophilic compound with low oral bioavailability. Previous studies showed that γ‐T3 has low intestinal permeability. Thus, we have hypothesized that enhancing γ‐T3 intestinal permeability will increase its oral bioavailability. Solid lipid nanoparticles (SLN) were tested as a model formulation to enhance γ‐T3 permeability and bioavailability. γ‐T3 intestinal permeability was compared using in situ rat intestinal perfusion, followed by in vivo relative oral bioavailability studies. In addition, in vitro cellular uptake of γ‐T3 from SLN was compared to mixed micelles (MM) in a time and concentration‐dependent studies. To elucidate the uptake mechanism(s) of γ‐T3 from SLN and MM the contribution of NPC1L1 carrier‐mediated uptake, endocytosis and passive permeability were investigated. In situ studies demonstrated SLN has tenfold higher permeability than MM. Subsequent in vivo studies showed γ‐T3 relative oral bioavailability from SLN is threefold higher. Consistent with in situ results, in vitro concentration dependent studies revealed γ‐T3 uptake from SLN was twofold higher than MM. In vitro mechanistic characterization showed that while endocytosis contributes to γ‐T3 uptake from both formulations, the reduced contribution of NPC1L1 to the transport of γ‐T3, and passive diffusion enhancement of γ‐T3 are primary explanations for its enhanced uptake from SLN. In conclusion, SLN successfully enhanced γ‐T3 oral bioavailability subsequent to enhanced passive permeability.
Is news media related to civic engagement? The effects of interest in and discussions about the news media on current and future civic engagement of adolescents
Authors: Erentaitė Rasa , Žukauskienė Rita , Beyers Wim , Pilkauskaitė‐Valickienė Rasa 
Published: January 2012

ABSTRACTThis study explored whether discussions about the media, when positively linked to interest in the news media, were related to adolescents' current and future civic engagement. A sample of 2638 adolescents (ageM = 17,SD = 1.2), who participated in a school‐based study on positive socialization, completed self‐report measures on interest in the news media and discussions about the media with parents and friends. Current civic engagement was measured by involvement in volunteering and civic commitments. Future civic engagement was measured by intentions to participate in civic activities in the future. The results showed that more interpersonal discussions about the media and higher interest in the news media both predicted higher civic engagement. Positive links between discussions about the media and current civic engagement were partly mediated by interest in the news media. In addition, interest in the news media together with current civic engagement fully mediated a positive link between discussions about the media and future civic engagement. Moderating effects of gender were observed, with discussions about the media a better predictor of boys' interest in the news media, and current civic engagement a better predictor of girls' future civic engagement.
Entering into politics: Interdiscursivity, register, stance, and vernacular in northern Italy
Authors: Cavanaugh Jillian R. 
Published: January 2012

AbstractThis article focuses on how specific types of language use connect socially, geographically, and temporally distant speakers and span face-to-face and mediated language contexts. It examines one variety of political language (the Northern League register in Italy) in order to analyze how the interdiscursive potentials of register and stance-taking enable such connections. It also presents the metapragmatic effects of engaging in types of talk such as political language, which are less about individual expression or political participation, but are rather part of a complex of stance-taking and alignment of self within local and national political debates. Based on long-term ethnographic and linguistic research in Bergamo, Italy, this article introduces the concept of the interdiscursive trap, showing how the Northern League register functions in this capacity, forging indexical links to particular ideas and stances that some speakers find undesirable. (Political language, interdiscursivity, register, stance, Italy, Europe, Northern League, media)*
Across languages and cultures: Brokering problems of understanding in conversational repair
Authors: Bolden Galina B. 
Published: January 2012

AbstractThis article examines the interactional construction of language competence in bilingual immigrant communities. The focus is on how participants in social interaction resolve problems of understanding that are demonstrably rooted in their divergent linguistic and cultural expertise. Using the methodology of conversation analysis to examine mundane video-recorded conversations in Russian-American immigrant families, I describe a previously unanalyzed communicative practice for solving understanding problems: by one participant enacting the role of a language broker in a repair sequence. The article thus contributes to the existing research on the interactional construction of language competence, on the one hand, and on the organization of repair and its relationship to social epistemics, on the other. (Language brokering, repair, conversation analysis, social epistemics, multiparty conversation, Russian, immigrant families, intercultural communication)*
Impact of the Manaus urban plume on trace gas mixing ratios near the surface in the Amazon Basin: Implications for the NO‐NO2‐O3 photostationary state and peroxy radical levels
Authors: Trebs Ivonne , Mayol‐Bracero Olga L. , Pauliquevis Theotonio , Kuhn Uwe , Sander Rolf , Ganzeveld Laurens , Meixner Franz X. , Kesselmeier Jürgen , Artaxo Paulo , Andreae Meinrat O. 
Published: January 2012

We measured the mixing ratios of NO, NO2, O3, and volatile organic carbon as well as the aerosol light‐scattering coefficient on a boat platform cruising on rivers downwind of the city of Manaus (Amazonas State, Brazil) in July 2001 (Large‐Scale Biosphere‐Atmosphere Experiment in Amazonia‐Cooperative LBA Airborne Regional Experiment‐2001). The dispersion and impact of the Manaus plume was investigated by a combined analysis of ground‐based (boat platform) and airborne trace gas and aerosol measurements as well as by meteorological measurements complemented by dispersion calculations (Hybrid Single‐Particle Lagrangian Integrated Trajectory model). For the cases with the least anthropogenic influence (including a location in a so far unexplored region ∼150 km west of Manaus on the Rio Manacapuru), the aerosol scattering coefficient, σs, was below 11 Mm−1, NOx mixing ratios remained below 0.6 ppb, daytime O3 mixing ratios were mostly below 20 ppb and maximal isoprene mixing ratios were about 3 ppb in the afternoon. The photostationary state (PSS) was not established for these cases, as indicated by values of the Leighton ratio, Φ, well above unity. Due to the influence of river breeze systems and other thermally driven mesoscale circulations, a change of the synoptic wind direction from east‐northeast to south‐southeast in the afternoon often caused a substantial increase of σs and trace gas mixing ratios (about threefold for σs, fivefold for NOx, and twofold for O3), which was associated with the arrival of the Manaus pollution plume at the boat location. The ratio Φ reached unity within its uncertainty range at NOx mixing ratios of about 3 ppb, indicating “steady‐state” conditions in cases when radiation variations, dry deposition, emissions, and reactions mostly involving peroxy radicals (XO2) played a minor role. The median midday/afternoon XO2 mixing ratios estimated using the PSS method range from 90 to 120 parts per trillion (ppt) for the remote cases (σs < 11 Mm−1 and NOx < 0.6 ppb), while for the polluted cases our estimates are 15 to 60 ppt. These values are within the range of XO2 estimated by an atmospheric chemistry box model (Chemistry As A Box model Application‐Module Efficiently Calculating the Chemistry of the Atmosphere (CAABA/MECCA)‐3.0).
Establishing MIC breakpoints and the interpretation of in vitro susceptibility tests
Authors: MacGowan Alasdair P. , Wise Richard 
Published: January 2012

Abstract
The purpose of undertaking susceptibility testing, by whatever method, is to attempt to integrate the susceptibility of a population of potential pathogens with the pharmacokinetics of the antimicrobial and, whenever possible, to review this relationship in the light of clinical experience following therapy in clinical trials. Breakpoints are discriminatory antimicrobial concentrations used in the interpretation of results of susceptibility testing to define isolates as susceptible, intermediate or resistant. Clinical, pharmacological and microbiological considerations are important in setting breakpoints, and the ideal mix of these factors is unknown. Different countries have different approaches to this problem but, by and large, these approaches have much in common. This paper attempts to summarize the philosophy of the British Society for Antimicrobial Chemotherapy (BSAC) Working Party in its approach to setting breakpoints and to update the activities of the Working Party since it initially published breakpoints, approximately 10 years ago. The formula outlined by the BSAC Working Party in 1991 has been used to set the breakpoints presented here. The Working Party accepts that in the light of new knowledge, there is a need to reassess how breakpoints are defined, and this paper also summarizes the future activities of the Working Party.
Detection of methicillin/oxacillin resistance in staphylococci
Authors: Brown Derek F. J. 
Published: January 2012

Abstract
Methicillin/oxacillin-resistant staphylococci are heterogeneous in their expression of resistance to β-lactam agents and the test conditions have a major effect on the expression and therefore the detection of resistance. Conflicting recommendations regarding the most reliable method for routine use are partly related to differences between strains and there may be a variable interaction between the factors affecting the expression of resistance, including the agent tested, the medium, the NaCl concentration, the inoculum, temperature and period of incubation and the reading of endpoints. ‘Borderline’ resistant strains may have altered PBPs or be penicillinase hyperproducers, and these can be difficult to distinguish from resistant strains that carry the mecA gene. Recommended methods for MIC and disc diffusion testing are described, although it is unlikely that any single method will detect all resistant strains. Some rapid and/or automated methods are also available, including latex agglutination techniques for the detection of PBP2a. The gold standard method for the detection of resistance mediated by mecA is PCR, which is most commonly used as a reference method at present.
Structures of ketolides and macrolides determine their mode of interaction with the ribosomal target site
Authors: Douthwaite Stephen , Champney W. Scott 
Published: January 2012

Abstract
Ketolides are the most recent generation of antimicrobials derived from the 14-membered ring macrolide, erythromycin A. The main structural feature that differentiates ketolides from erythromycin is the keto group, which replaces the l-cladinose moiety at position 3 of the macrolactone ring. The keto group bestows greater acid stability on the drugs, and enables them to bind to their ribosomal target without causing expression of MLSB resistance in inducible strains. Several ketolides are described here, including ABT 773 and telithromycin (HMR 3647), both of which possess a carbamate at C11/C12 of the macrolactone ring. In telithromycin, which is the first ketolide to be approved for clinical use, the carbamate is linked to an alkyl-aryl extension, which is responsible for the increased potency of this compound relative to macrolides. This review examines how the structural differences between macrolides and the new ketolides are related to their antimicrobial activities in inhibiting protein synthesis and blocking the assembly of new ribosomal subunits.
Neonatal candidosis: clinical picture, management controversies and consensus, and new therapeutic options
Authors: Leibovitz Eugene 
Published: January 2012

Abstract
Candida infections are increasingly being recognized as a major cause of septicaemia in neonatal intensive care units, and are associated with high morbidity (25%) and mortality (25–54%). Low birth weight pre-term infants are especially vulnerable to this devastating disease. The most frequently encountered fungal infections are caused by Candida albicans, Candida parapsilosis and, rarely, by Candida tropicalis. Amphotericin B (with or without flucytosine) is the treatment of choice for Candida infections in neonates. Conventional amphotericin B use is often limited by its severe side effects, although these tend to be fewer in neonates than in adults. Possible alternatives to amphotericin B include triazoles (such as fluconazole) and lipid preparations of amphotericin B. Liposomal encapsulation of amphotericin B has been shown to decrease the toxicity of the drug while maintaining its antifungal activity. The liposomal formulation AmBisome has proved to be effective in the treatment of severe fungal infections in adult and paediatric immunocompromised patients who fail to respond to conventional amphotericin B. The experience with AmBisome in the treatment of fungal infections in neonates is limited, and the drug has been used mainly in infants either failing conventional amphotericin B or having intolerable toxicity. Pharmacokinetic studies have not yet been performed in neonates. Three uncontrolled studies published between 1997 and 1998 on AmBisome (dose range 1–7 mg/kg/day) in the treatment of neonatal candidosis revealed that the drug was effective and safe. New information is accumulating on the safe use of high-dose AmBisome (5–7 mg/kg/day) in very low birth weight infants, and successful use of the drug as first-line therapy of neonatal candidosis. These promising results suggest a potential role for AmBisome as an additional first-line treatment of systemic candidosis in neonates.
Amphotericin B: spectrum and resistance
Authors: Ellis David 
Published: January 2012

Abstract
Amphotericin B is a polyene macrolide antibiotic derived from the actinomycete Streptomyces nodosus. Of the 200 known polyene agents, amphotericin B is the only one with toxicities that are sufficiently limited to permit intravenous administration. All polyenes have a common mechanism of action in that they preferentially bind to ergosterol, the primary sterol in the fungal cell membrane. The consequence of this binding includes disruption of the osmotic integrity of the membrane, with leakage of intracellular potassium and magnesium, and also the disruption of oxidative enzymes in target cells. Amphotericin B has a relatively broad spectrum of action and is useful in treating cases of candidosis, cryptococcosis, histoplasmosis, blastomycosis, paracoccidioidomycosis, coccidioidomycosis, aspergillosis, extracutaneous sporotrichosis and mucormycosis, and some cases of hyalohyphomycosis and phaeohyphomycosis. Resistance (MIC &gt; 2 mg/L) tends to be species-dependent and emerges uncommonly and slowly in isolates from patients treated with amphotericin B. These include some individual strains of Candida albicans, Candida tropicalis, Candida parapsilosis and Candida lusitaniae, which may acquire resistance during treatment. Some isolates of Scedosporium apiospermum, Fusarium spp. and Sporothrix schenckii also show primary resistance, whereas all strains of Scedosporium prolificans demonstrate resistance. The main problems associated with the use of conventional amphotericin B have always been due to its poor aqueous solubility and toxicity rather than antifungal resistance.
Prophylaxis and treatment of patients with aspergillosis: an overview, including the Royal Melbourne Hospital experience
Authors: Grigg Andrew 
Published: January 2012

Abstract
Patients receiving allogeneic bone marrow transplants are at risk of developing Aspergillus infections. The pre-transplant risk factors for the development of invasive disease include prolonged neutropenia, colonization with Aspergillus sp. or a prior history of fungal infection. Post-transplant risk factors include severe graft-versus-host disease with concomitant high-dose corticosteroid therapy, and colonization with Aspergillus sp. The antifungal prophylaxis of selected high-risk pre-transplant patients at the Royal Melbourne Hospital includes granulocyte transfusions and AmBisome. In high-risk patients post-engraftment, prophylaxis consists of oral itraconazole, or if it cannot be tolerated, AmBisome. Antifungal prophylaxis is discontinued upon resolution of neutropenia, when prednisolone dose falls below 10 mg/day or when Aspergillus colonization disappears. Following this regimen, there has been only one death due to fungal infection in over 80 consecutive allograft patients. This patient was infected with an amphotericin B-resistant organism.
Liposomal amphotericin B versus conventional amphotericin B in the empirical treatment of persistently febrile neutropenic patients
Authors: Cagnoni Pablo J. 
Published: January 2012

Abstract
Liposomal amphotercin B was compared with conventional amphotericin B for empirical antifungal therapy in febrile neutropenic patients in a randomized, double-blind, multicentre trial. Using a composite end-point, the two drugs were equivalent in overall efficacy. However, the liposomal amphotericin B treatment group had fewer proven fungal infections, fewer infusion-related side effects and less nephrotoxicity. Patient data from that study were analysed to compare the pharmacoeconomics of liposomal versus conventional amphotericin B therapy. Itemized billing data from 414 patients were collected and analysed. Hospital costs from first dose were significantly higher for all patients who received liposomal amphotericin B ($48 962 versus $43 183, P = 0.02). However, hospital costs were very sensitive to the cost of the study medication ($39 648 versus $43 048, when acquisition costs are not included, P = 0.4). Using decision analysis models and sensitivity analyses to vary the cost of study medications and risk of nephrotoxicity, the break-even points for the cost of liposomal therapy were calculated to range from $72 to $87 per 50 mg for all patients, and $83 to $112 per 50 mg in allogeneic bone marrow transplant patients. Therefore, the drug acquisition costs and the risk of nephrotoxicity are important factors in determining the cost-effectiveness of liposomal amphotericin B as empirical therapy in persistently febrile neutropenic patients. In a recent randomized double-blind study comparing liposomal amphotericin B at 3 or 5 mg/kg/day with amphotericin B lipid complex (ABLC) 5 mg/kg/day as empirical antifungal treatment in patients with febrile neutropenia, liposomal amphotericin B was associated with less toxicity than ABLC, both in terms of infusion-related reactions and nephrotoxicity. The incidence of study drug discontinuation due to toxicity was: liposomal amphotericin B 3 mg/kg/day, 14%; liposomal amphotericin B 5 mg/kg/day, 15%; and ABLC, 42% (P &lt; 0.001).