bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between enzyme activity and dimeric structure of recombinant HIV‐1 reverse transcriptase
Authors: Tachedjian G. , Radzio J. , Sluis‐Cremer N. 
Published: April 2005

AbstractThe multifunctional enzyme human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) is a heterodimer composed of a 66‐kDa (p66) subunit and a p66‐derived 51‐kDa (p51) subunit. p66/p51 HIV‐1 RT contains 1 functional DNA polymerase and 1 ribonuclease H (RNase H) active site, which both reside in the p66 subunit at spatially distinct regions. In this study, we have investigated the relationship between the heterodimeric structure of HIV‐1 RT and its enzymatic properties by introducing mutations at RT codon W401 that inhibit the formation of p66/p51 heterodimers. We demonstrate a striking correlation between abrogation of both HIV‐1 RT dimerization and DNA polymerase activity. In contrast, the p66 monomers exhibited only moderately slowed catalytic rates of DNA polymerase‐dependent and DNA polymerase‐independent RNase H cleavage activity compared with the wild‐type (WT) enzyme. Furthermore, no major changes in the unique cleavage patterns were observed between the WT and mutant enzymes for the different substrates used in the RNase H cleavage assays. Based on these results, and on our current understanding of HIV‐1 RT structure, we propose that the p66 monomer can adopt an open tertiary conformation that is similar to that observed for the subunit in the heterodimeric enzyme. We also propose that the formation of intersubunit interactions in HIV‐1 RT regulates the establishment of a functional DNA polymerase active site. Proteins 2005. © 2005 Wiley‐Liss, Inc.
A consistent set of statistical potentials for quantifying local side‐chain and backbone interactions
Authors: Fang Qiaojun , Shortle David 
Published: April 2005

AbstractThe frequencies of occurrence of atom arrangements in high‐resolution protein structures provide some of the most accurate quantitative measures of interaction energies in proteins. In this report we extend our development of a consistent set of statistical potentials for quantifying local interactions between side‐chains and the polypeptide backbone, as well as nearby side‐chains. Starting with ϕ/ψ/χ1 propensities that select for optimal interactions of the 20 amino acid side‐chains with the 2 flanking peptide bonds, the following 3 new terms are added: (1) a distance‐dependent interaction between the side‐chain at i and the carbonyl oxygens and amide protons of the peptide units at i ± 2, i ± 3, and i ± 4; (2) a distance‐dependent interaction between the side‐chain at position i and side‐chains at positions i + 1 through i + 4; and (3) an orientation‐dependent interaction between the side‐chain at position i and side‐chains at i + 1 through i + 4. The relative strengths of these 4 pseudo free energy terms are estimated by the average information content of each scoring matrix and by assessing their performance in a simple fragment threading test. They vary from −0.4–−0.5 kcal/mole per residue for ϕ/ψ/χ1 propensities to a range of −0.15–−0.6 kcal/mole per residue for each of the other 3 terms. The combined energy function, containing no interactions between atoms more than 4 residues apart, identifies the correct structural fragment for randomly selected 15 mers over 40% of the time, after searching through 232,000 alternative conformations. For 14 out of 20 sets of all‐atom Rosetta decoys analyzed, the native structure has a combined score lower than any of the 1700–1900 decoy conformations. The ability of this energy function to detect energetically important details of local structure is demonstrated by its power to distinguish high‐resolution crystal structures from NMR solution structures. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Insights into OLED functioning through coordinated experimental measurement and numerical model simulations [phys. stat. sol. (a) Vol. 202, No. 1, pp. 9–36 (2005)]
Authors: Berner D. , Houili H. , Leo W. , Zuppiroli L. 
Published: April 2005

AbstractSee original physica status solidi (a) Vol. 202, No. 1, pp. 9–36 (2005)
Lignans from Acanthopanax chiisanensis having an inhibitory activity on prostaglandin E2 production
Authors: Lee Sanghyun , Ban Hyun Seung , Kim Yong Pil , Kim Bak‐Kwang , Cho Seon Haeng , Ohuchi Kazuo , Shin Kuk Hyun 
Published: April 2005

AbstractThe chloroform and the ethyl acetate fractions from the roots of Acanthopanax chiisanensis exhibited the significant inhibition of TPA‐induced prostaglandin E2 (PGE2) production in rat peritoneal macrophages. Five lignans were isolated from the chloroform fraction and their structures were elucidated as l‐sesamin, helioxanthin, savinin, taiwanin C, and 3‐(3,4‐dimethoxybenzyl)‐2‐(3,4‐methylenedioxybenzyl)butyrolactone. Among the lignans tested, taiwanin C showed the most potent inhibitory activity (IC50 = 0.12 µM) on PGE2 production with the relative order of potency, taiwanin C ≫ 3‐(3,4‐dimethoxybenzyl)‐2‐(3,4‐methylenedioxybenzyl)butyrolactone > savinin = helioxanthin. l‐Sesamin showed no inhibitory activity at 30 µM. Copyright © 2005 John Wiley & Sons, Ltd.
Antiproliferative effects of daucane esters from Ferula communis and F. arrigonii on human colon cancer cell lines
Authors: Poli F. , Appendino G. , Sacchetti G. , Ballero M. , Maggiano N. , Ranelletti F. O. 
Published: April 2005

AbstractCertain jaesekanadiol p‐hydroxy‐ and p‐methoxybenzoates – typical of Ferula communis and Ferula arrigonii sardinian plants – show antiproliferative activity on human colon cancer less. The inhibitory doses 50%, calculated after 72 h of treatment, revealed that the antiproliferative capacity of the compounds was in the following descending order: ferutinin > 2α‐OH‐ferutidin > ferutidin > siol anisate > lapiferin > jaeskeanadiol. Evidence is presented that interaction with type II estrogen‐binding sites (EBS) underlies this activity. Copyright © 2005 John Wiley & Sons, Ltd.
Protective effect of Sargassum polycystum (brown alga) against acetaminophen‐induced lipid peroxidation in rats
Authors: Raghavendran Hanumantha Rao Balaji , Sathivel Arumugam , Devaki Thiruvengadam 
Published: April 2005

AbstractLipid peroxidation is believed to play an important role in the pathogenesis of several diseases, such as cancer, diabetic mellitus and liver injury. Aqueous and ethanol extracts of Sargassum polycystum C. Agardh (Phaeophyta) were screened for their protective effects against acetaminophen (ACP; Paracetamol)‐induced lipid peroxidation in rats. A single dose of acetaminophen significantly elevated the levels of lipid peroxides (LPO) with decreased levels of free radical scavenger enzymes (SOD, CAT, GSH, GPx, GST) in liver homogenate. The oral pretreatment of rats with ethanol and aqueous extracts of Sargassum polycystum C. Agardh (100 mg, 200 mg[sol ]kg body wt[sol ]day respectively, for a period of 15 days) significantly reduced the acetaminophen‐induced oxidative stress in rats. The animals treated with the ethanol and aqueous extracts alone did not show any toxicity on liver tissue. This observation shows that the seaweed crude extracts probably acted to protect against acetaminophen‐induced lipid peroxidation through their free radical scavenging property. Copyright © 2005 John Wiley & Sons, Ltd.
Hepatoprotective activity of aqueous–methanol extract of Artemisia vulgaris
Authors: Gilani Anwarul Hassan , Yaeesh Sheikh , Jamal Qamar , Ghayur M. Nabeel 
Published: April 2005

AbstractThe effect of a crude extract of the aerial parts of Artemisia vulgaris (Av.Cr) was investigated against D‐galactosamine (D‐GalN) and lipopolysaccharide (LPS) induced hepatitis in mice. Co‐administration of D‐GalN (700 mg[sol ]kg) and LPS (1 µg[sol ]kg) significantly (p < 0.05) raised the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in mice in the toxin group compared with the values in the control group. Pre‐treatment of mice with different doses of Av.Cr (150–600 mg[sol ]kg) significantly (p < 0.05) reduced the toxin‐induced rise in plasma ALT and AST. The hepatoprotective effect was further verified by histopathology of the liver, which showed improved architecture, absence of parenchyma congestion, decreased cellular swelling and apoptotic cells, compared with the findings in the toxin group of animals. These findings scientifically validated the traditional use of Artemisia vulgaris for various liver disorders. Copyright © 2005 John Wiley & Sons, Ltd.
Ritual use of plants with possible action on the central nervous system by the Krahô Indians, Brazil
Authors: Rodrigues Eliana , Carlini E. A. 
Published: April 2005

AbstractThe aim of the present study was to document the use of plants, probably acting on the central nervous system (CNS), in rituals carried out by the Krahô Indians, who occupy the cerrado biome in the central region of Brazil. The 2 years of fieldwork were guided by methods of anthropology and botany. The local shamans have indicated 286 formulas, consisting of 138 plant species in 50 uses that could be associated with some type of action on the CNS; of which 98 formulas, 87 plants and 25 uses, appear to involve psychoactive properties, such as: ‘to get slow’, ‘stimulant effect’, ‘to calm down’, ‘to enhance memory’, ‘to reduce anxiety’ and ‘to induce sleep’. Phytochemical and pharmacological literature data were queried to establish any correlation between indigenous knowledge and scientific indications, for each one of the 138 plant species. Studies were available for 11 of these plants; and for two of them, scientific data coincided with indigenous information. Copyright © 2005 John Wiley & Sons, Ltd.
Cytotoxic constituents of the twigs of Simarouba glauca collected from a plot in Southern Florida
Authors: Rivero‐Cruz J. Fausto , Lezutekong Raphael , Lobo‐Echeverri Tatiana , Ito Aiko , Mi Qiuwen , Chai Hee‐Byung , Soejarto Djaja D. , Cordell Geoffrey A. , Pezzuto John M. , Swanson Steven M. , Morelli Ivano , Kinghorn A. Douglas 
Published: April 2005

AbstractActivity‐guided fractionation of a chloroform‐soluble extract of Simarouba glauca twigs collected from a plot in southern Florida, and monitored with a human epidermoid (KB) tumor cell line, afforded six canthin‐6‐one type alkaloid derivatives, canthin‐6‐one (1), 2‐methoxycanthin‐6‐one (2), 9‐methoxycanthin‐6‐one (3), 2‐hydroxycanthin‐6‐one (4), 4,5‐dimethoxycanthin‐6‐one (5) and 4,5‐dihydroxycanthin‐6‐one (6), a limonoid, melianodiol (7), an acyclic squalene‐type triterpenoid, 14‐deacetyleurylene (8), two coumarins, scopoletin (9) and fraxidin (10), and two triglycerides, triolein (11) and trilinolein (12). Among these isolates, compounds 1–4, 7 and 8 exhibited cytotoxic activity against several human cancer cell lines. 14‐Deacetyleurylene (8) was selectively active against the Lu1 human lung cancer cell line, but was inactive in an in vivo hollow fiber assay using this same cell type. Copyright © 2005 John Wiley & Sons, Ltd.
Antifungal activity of steroidal glycosides from Yucca gloriosa L.
Authors: Favel A. , Kemertelidze E. , Benidze M. , Fallague K. , Regli P. 
Published: April 2005

AbstractThe antifungal activity of a crude steroidal glycoside extract from Yucca gloriosa flowers, named alexin, was investigated in vitro against a panel of human pathogenic fungi, yeasts as well as dermatophytes and filamentous species. The minimal inhibitory concentration (MIC) was determined by an agar dilution method. Alexin had a broad spectrum of antifungal activity, found to reside entirely in the spirostanoid fraction. The major tigogenyl glycosides, yuccaloeside B and yuccaloeside C, exhibited MICs between 0.39 and 6.25 µg[sol ]mL for all the tested yeast strains except for two (C. lusitaniae and C. kefyr). They were also active against several clinical Candida isolates known to be resistant to the usual antifungal agents. The MICs for the dermatophytes were between 0.78 and 12.5 µg[sol ]mL. The most sensitive filamentous species was A. fumigatus (MIC = 1.56 µg[sol ]mL). For most of the strains, the MICs of both glycosides were similar to those of the reference antifungal agent. Copyright © 2005 John Wiley & Sons, Ltd.
Multireference configuration interaction and coupled‐cluster calculations on the X3Σ−, a1Δ, and b1Σ+ states of the NF molecule
Authors: Kardahakis Stavros , Pittner Jiří , Čársky Petr , Mavridis Aristides 
Published: April 2005

AbstractThe X3Σ−, a1Δ, and b1Σ+ states of the NF molecule were examined by a variety of ab initio methods, including the newly developed multireference Brillouin‐Wigner coupled‐cluster technique. Using correlation consistent sets of triple‐ and augmented quadruple‐quality, we constructed full potential energy curves obtaining dissociation energies and spectroscopic constants. It was reconfirmed that the X3Σ− binding energy is 77.0 kcal/mol, in contrast to recent experimental results claiming a value of about 61 kcal/mol. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
PARAMETER SETTING IN LANGUAGE ACQUISITION
Authors: Montrul Silvina 
Published: April 2005

PARAMETER SETTING IN LANGUAGE ACQUISITION. Dalila Ayoun. New
York: Continuum, 2003. Pp. x + 212. $110.00 cloth.This book presents an overview of the parameter setting theory of
learnability in first (L1) and second (L2) language acquisition within
the generative linguistic framework. It also attempts to challenge and
refine common assumptions underlying the model. The book comprises five
central chapters as well as short introductory and concluding chapters.
The introductory chapter summarizes the general aim of the book and the
specific aims of the chapters to follow. In chapter 2, Ayoun presents
historical background on the concept of parameter throughout
different versions of generative linguistics and distinguishes the
standard notion of parameter from the notions of associated clusters of
structures, microparameters (referring to structures), and
macroparameters (which apply to a family of typologically different
languages). This chapter also reviews the concept of parameter setting
for language changes, creole formation, computational linguistics, and
neurolinguistics, ending with a brief discussion of Universal Grammar
and the Critical Period Hypothesis. In brief, this chapter argues that
the parameter setting approach is a model worthy of further development
and refinement, capable of explaining and predicting a wide range of
phenomena in linguistic theory and its applications despite
misunderstandings and lack of clarity in the field.
TEACHING ACADEMIC ESL WRITING: PRACTICAL TECHNIQUES IN VOCABULARY
AND GRAMMAR
Authors: Cohen Alissa 
Published: April 2005

TEACHING ACADEMIC ESL WRITING: PRACTICAL TECHNIQUES IN VOCABULARY AND
GRAMMAR. Eli Hinkel. Mahwah, NJ: Erlbaum, 2004. Pp. xii + 360.
$79.95 cloth, $37.50 paper.In this text, Hinkel argues that second language (L2) writing
instruction has long favored teaching the writing process and discourse
and rhetorical features of text while neglecting the essential language
skills that L2 writers need to succeed in mainstream university
classes. She attempts to redress this perceived shortcoming by
identifying and describing the formal syntactic and lexical
characteristics of academic text and advocating the explicit teaching
of these key structures and lexical chunks.
LITERACY AND THE SECOND LANGUAGE LEARNER
Authors: Haynes Margot 
Published: April 2005

LITERACY AND THE SECOND LANGUAGE LEARNER. Joann Hammadou Sullivan
(Ed.). Greenwich, CT: Information Age, 2002. Pp. xii + 279. $29.95
paper.In this age of Internet plenty, research collections need a
justification for presentation in book format. According to the
editor's introduction, the main justification for Literacy and
the second language learner is to provide a sampling of the range
of “possible voices and possible questions that make up the broad
and complex field of second language literacy study” (p. xi).
PRAGMATIC DEVELOPMENT IN A SECOND LANGUAGE
Authors: Burt Susan Meredith 
Published: April 2005

PRAGMATIC DEVELOPMENT IN A SECOND LANGUAGE. Gabriele Kasper and
Kenneth R. Rose. Oxford: Blackwell, 2002. Pp. x + 352. $36.95
paper.The goal for this useful volume is to survey and evaluate research on
pragmatic development of second language learners. In the first
chapter, Kasper and Rose note that numerous studies in crosscultural
pragmatics assess nonnatives' language use and contrast it with
the performance of natives but that relatively few studies have focused
on how language learners' pragmatic abilities change and develop
over time. For researchers in SLA, however, this question of
development is central.
INVISIBLE WORK: BILINGUALISM, LANGUAGE CHOICE, AND CHILDREARING IN
INTERMARRIED FAMILIES
Authors: Bayley Robert 
Published: April 2005

INVISIBLE WORK: BILINGUALISM, LANGUAGE CHOICE, AND CHILDREARING IN
INTERMARRIED FAMILIES. Toshie Okita. Amsterdam: Benjamins,
2002. Pp. vi + 274. $102.00 cloth.In recent years, studies of bilingualism and SLA have paid increasing
attention to the contexts in which languages are acquired and used.
This broadened perspective has led scholars to combine insights from a
number of different disciplines. In this highly original study, Okita
combines insights from studies of families, ethnicity, and bilingualism
to examine the factors that promote or inhibit Japanese maintenance by
the children of British fathers and Japanese mothers living in Britain.
The result is a finely nuanced study that illustrates the difficulties
of maintaining a minority language in a setting that provides few
sources of institutional support.
Diabetes‐induced changes in the 5‐hydroxytryptamine inhibitory receptors involved in the pressor effect elicited by sympathetic stimulation in the pithed rat
Authors: García Mónica , Morán Asunción , Calama Elena , Martín Maria Luisa , Barthelmebs Mariette , Román Luis San 
Published: April 2005

We investigated the effect of alloxan‐induced diabetes on the inhibitory mechanisms of 5‐hydroxytryptamine (5‐HT) in the pressor responses induced by stimulation of sympathetic vasopressor outflow in pithed rats, and analysed the type and/or subtype of 5‐HT receptors involved.
Diabetes was induced in male Wistar rats by a single s.c. injection of alloxan, then 4 weeks later, they were anaesthetized, pretreated with atropine and pithed. Electrical stimulation of the sympathetic outflow from the spinal cord (0.1, 0.5, 1 and 5 Hz) resulted in frequency‐dependent increases in blood pressure.
Intravenous infusions of 5‐HT (1–80 μg kg−1 min−1) reduced the pressor effects obtained by electrical stimulation. The 5‐HT1 receptor agonist 5‐carboxamidotryptamine, 5‐CT (5 μg kg−1 min−1), caused an inhibition of the pressor response, whereas the selective 5‐HT2 receptor agonist, α‐methyl‐5‐HT (5 μg kg−1 min−1) and the selective 5‐HT3 receptor agonist, 1‐phenylbiguanide (40 μg kg−1 min−1), did not modify the sympathetic pressor responses. 5‐HT had no effect on exogenous noradrenaline (NA)‐induced pressor responses.
The inhibition of electrically induced pressor responses by 5‐HT (10 μg kg−1 min−1) was unable to be elicited after i.v. treatment with methiothepin (100 μg kg−1) because of the marked inhibition produced by methiothepin alone. The 5‐HT‐induced inhibition was blocked after i.v. administration of WAY‐100,635 (100 μg kg−1) and not affected by ritanserin (1 mg kg−1), MDL 72222 (2 mg kg−1).
The selective 5‐HT1A receptor agonist, 8‐hydroxydipropylaminotretalin hydrobromide (8‐OH‐DPAT) (5–20 μg kg−1 min−1) but neither the rodent 5‐HT1B receptor agonist, CGS‐12066B (5 μg kg−1 min−1), nor the selective nonrodent 5‐HT1B and 5‐HT1D receptor agonist, L‐694,247 (5 and 40 μg kg−1 min−1), inhibited the electrically induced pressor response. The selective 5‐HT1A receptor antagonist, WAY‐100,635 (100 μg kg−1), blocked the inhibition induced by 8‐OH‐DPAT (10 μg kg−1 min−1). 8‐OH‐DPAT had no effect on exogenous NA‐induced pressor responses.
Experimental diabetes produces changes in the inhibitory effect induced by 5‐HT on electrically induced sympathetic pressor responses, such that the inhibitory action induced by 5‐HT in diabetic pithed rats is mediated by prejunctional 5‐HT1A receptors.

British Journal of Pharmacology (2005) 145, 593–601. doi:10.1038/sj.bjp.0706216
Phase 2 ventricular arrhythmias in acute myocardial infarction: a neglected target for therapeutic antiarrhythmic drug development and for safety pharmacology evaluation
Authors: Clements‐Jewery Hugh , Hearse David J , Curtis Michael J 
Published: April 2005

Ventricular fibrillation (VF), a cause of sudden cardiac death (SCD) in the setting of acute myocardial infarction (MI), remains a major therapeutic challenge. In humans, VF may occur within minutes or hours after the onset of chest pain, so its precise timing in relation to the onset of ischaemia is variable. Moreover, because VF usually occurs unobserved, out of hospital, and is usually lethal in the absence of intervention, its precise timing of onset is actually unknown in most patients. In animal models, the timing of susceptibility to VF is much better characterised. It occurs in two distinct phases. Early VF (defined as phase 1 VF, with possible subphases 1a and 1b in some animal species) occurs during the first 30 min of ischaemia when most myocardial injury is still reversible. Late VF, defined as phase 2 VF, occurs when myocardial necrosis is becoming established (after more than 90 min of ischaemia). Although much is known about the mechanisms and pharmacology of phase 1 VF, little is known about phase 2 VF. By reviewing a range of different types of data we have outlined the likely mechanisms and clinical relevance of phase 2 VF, and have evaluated possible future directions to help evolve a strategy for its suppression by drugs. The possibility that a proarrhythmic effect on phase 2 VF contributes to the adverse cardiac effects of certain cardiac and noncardiac drugs is also discussed in relation to the emerging field of safety pharmacology. It is concluded that suppression of phase 2 as well as phase 1 VF will almost certainly be necessary if drugs of the future are to achieve what drugs of the past and present have failed to achieve: full protection against SCD. Likewise, safety will require avoidance of exacerbation of phase 2 as well as phase 1 VF.British Journal of Pharmacology (2005) 145, 551–564. doi:10.1038/sj.bjp.0706231
Variation in Ferroelectric Characteristics of Lead Zirconate Titanate Ceramics Due to Minor Chemical Modifications
Authors: Gerson Robert 
Published: April 2005

Lead zirconate titanate ceramics with certain 3- or 5-valent additions (lanthanum, neodynium, tantalum, and niobium) are found to be characterized by low aging of electrical and mechanical properties, a well-defined hysteresis loop, and by high electrical and mechanical losses. Experimental investigations are reported on plain lead zirconate titanate and on a low-aging niobium modification.
The experiments included an electron microscope study of the ceramics and a number of electrical measurements. As a result of the study, the changed properties of the substituted material have been explained as being due to domain wall motion under low electric field. The results of electrical measurements supporting this conclusion, and a hypothesis accounting for the effects in terms of lattice vacancies, are presented.
The 3- or 5-valent additives described in the foregoing also cause greatly increased volume resistivity in the ceramic. This has not been satisfactorily explained.