bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melatonin elicits nuclear exclusion of the human androgen receptor and attenuates its activity
Authors: Rimler Avi , Culig Zoran , Levy‐Rimler Galit , Lupowitz Zippora , Klocker Helmut , Matzkin Haim , Bartsch Georg , Zisapel Nava 
Published: August 2002

AbstractBackgroundThe androgen receptor (AR) promotes growth and functionality of androgen sensitive benign and cancer tissues. The pineal hormone melatonin is an androgen protagonist in vivo and in vitro. The interference of melatonin in the AR cascade was explored.MethodsThe effects of melatonin on AR expression, level, agonist and androgen‐response element (ARE) binding, reporter gene activity and intracellular localization were explored in prostate cancer LNCaP cell line.ResultsMelatonin increased immunoreactive AR cells in the absence and presence of dihydrotestosterone. Despite this increase and maintenance of AR agonist binding capacity, the androgen‐induced reporter gene activity and suppression of AR‐mRNA were attenuated. Immunocytochemical analysis and subcellular fractionation studies revealed nuclear exclusion of AR by melatonin.ConclusionsThe melatonin‐mediated nuclear exclusion of the AR may explain the attenuation of AR activity in the prostate cancer cells. This is the first demonstration of a hormone‐induced mislocalization of the AR in prostate epithelial cells and may represent a novel route for regulating AR activity. Prostate 49:145–154, 2001. © 2001 Wiley‐Liss, Inc.
Prediction of protein cellular attributes using pseudo‐amino acid composition
Authors: Chou Kuo‐Chen 
Published: August 2002

AbstractThe cellular attributes of a protein, such as which compartment of a cell it belongs to and how it is associated with the lipid bilayer of an organelle, are closely correlated with its biological functions. The success of human genome project and the rapid increase in the number of protein sequences entering into data bank have stimulated a challenging frontier: How to develop a fast and accurate method to predict the cellular attributes of a protein based on its amino acid sequence? The existing algorithms for predicting these attributes were all based on the amino acid composition in which no sequence order effect was taken into account. To improve the prediction quality, it is necessary to incorporate such an effect. However, the number of possible patterns for protein sequences is extremely large, which has posed a formidable difficulty for realizing this goal. To deal with such a difficulty, the pseudo‐amino acid composition is introduced. It is a combination of a set of discrete sequence correlation factors and the 20 components of the conventional amino acid composition. A remarkable improvement in prediction quality has been observed by using the pseudo‐amino acid composition. The success rates of prediction thus obtained are so far the highest for the same classification schemes and same data sets. It has not escaped from our notice that the concept of pseudo‐amino acid composition as well as its mathematical framework and biochemical implication may also have a notable impact on improving the prediction quality of other protein features. Proteins 2001;43:246–255. © 2001 Wiley‐Liss, Inc.
Protein molecular dynamics with the generalized born/ACE solvent model
Authors: Calimet Nicolas , Schaefer Michael , Simonson Thomas 
Published: August 2002

AbstractImplicit solvent models are increasingly important for the study of proteins in aqueous solution. Here, the generalized Born (GB) solvent polarization model as implemented in the analytical ACE potential [Schaefer and Karplus (1996) J Phys Chem 100:1578] is used to perform molecular dynamics simulations of two small, homologous proteins: the immunoglobulin‐binding domain of streptococcal protein G and the Ras binding domain of Raf. Several model parameterizations are compared through more than 60 ns of simulation. Results are compared with two simpler solvent models—an accessible surface area model and a distant‐dependent dielectric model, with finite‐difference Poisson calculations, with existing explicit solvent simulations, and with experimental data. The simpler models yield stable but distorted structures. The best GB/ACE implementation uses a set of atomic Voronoi volumes reported recently, obtained by averaging over a large database of crystallographic protein structures. A 20% reduction is applied to the volumes, compensating in an average sense for an excessive de‐screening of individual charges inherent in the ACE self‐energy and for an undersolvation of dipolar groups inherent in the GB screening function. This GB/ACE parameterization yields stable trajectories on the 0.5–1‐ns time scale that deviate moderately (∼1.5–2.5 Å) from the X‐ray structure, reproduce approximately the surface distribution of charged, polar, and hydrophobic groups, and reproduce accurately backbone flexibility as measured by amide NMR‐order parameters. Over longer time scales (1.5–3 ns), some of the protein G runs escape from the native energy basin and deviate strongly (3 Å) from the native structure. The conformations sampled during the transition out of the native energy basin are overstabilized by the GB/ACE solvation model, as compared with a numerical treatment of the full dielectric continuum model. Proteins 2001;45:144–158. © 2001 Wiley‐Liss, Inc.
Structure and diversity of insect nicotinic acetylcholine receptors
Authors: Tomizawa Motohiro , Casida John E 
Published: August 2002

AbstractThe nicotinic acetylcholine receptor (nAChR) is an agonist‐regulated ion‐channel complex responsible for rapid neurotransmission. The vertebrate nAChR, assembled from five homologous subunits, penetrates the synaptic membrane. Different subunit combinations lead to receptor subtypes with distinctive pharmacological profiles. In comparison with mammalian nAChRs, the insect receptor is poorly understood relative to functional architecture and diversity. Several genes for Drosophila, Locusta and Myzus encoding insect nAChR subunits have been identified, although the functional assembly and presence of different subtypes of these receptors are not defined. The insect nAChR is the primary target site for the neonicotinoid insecticides, thereby providing an incentive to explore its functional architecture with neonicotinoid radioligands, photoaffinity probes and affinity chromatography matrices. This review considers the current understanding of the structure and diversity of insect nAChRs based mainly on recent studies in molecular biology and protein biochemistry.© 2001 Society of Chemical Industry
The role of tryptophan in the antibacterial activity of a 15‐residue bovine lactoferricin peptide
Authors: Haug Bengt Erik , Svendsen John S 
Published: August 2002

AbstractBovine lactoferricin is a 25‐residue antibacterial peptide isolated after gastric cleavage of the iron transporting protein lactoferrin. A 15‐residue fragment, FKCRRWQWRMKKLGA of this peptide sustains most of the antibacterial activity. In this truncated sequence, the two Trp residues are found to be essential for antibacterial activity. The anchoring properties of Trp, as have been observed in membrane proteins, are believed to be important for the interaction of Trp containing antibacterial peptides with bacterial cell membranes. We have investigated the molecular properties which make Trp important for the antibacterial activity of the 15‐residue peptide by replacing Trp with natural and unnatural aromatic amino acids. This series of peptides was tested for antibacterial activity against Echerichia coli and Staphylococcus aureus. We found that neither the hydrogen bonding ability nor the amphipathicity of the indole system are essential properties for the effect of Trp on the antibacterial activity of the peptides. Replacement of Trp with residues containing aromatic hydrocarbon side chains gave the most active peptides. We propose that aromatic hydrocarbon residues are able to position themselves deeper into the bacterial cell membrane, making the peptide more efficient in disrupting the bacterial cell membrane. From our results the size, shape and aromatic character of Trp seem to be the most important features for the activity of this class of Trp containing antibacterial peptides. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd.
Effect of fire on concrete and concrete structures
Authors: Khoury Gabriel Alexander 
Published: August 2002

AbstractThe behaviour of concrete in fire depends on its mix proportions and constituents and is determined by complex physicochemical transformations during heating. Normal‐strength concretes and high‐performance concretes microstructurally follow similar trends when heated, but ultra‐high‐performance concrete behaves differently. A key property unique to concrete amongst structural materials is transient creep. Any structural analysis of heated concrete that ignores transient creep will yield erroneous results, particularly for columns exposed to fire. Failure of structural concrete in fire varies according to the nature of the fire; the loading system and the type of structure. Failure could occur from loss of bending or tensile strength; loss of bond strength; loss of shear or torsional strength; loss of compressive strength; and spalling of the concrete. The structural element should, therefore, be designed to fulfil its separating and/or load‐bearing function without failure for the required period of time in a given fire scenario. Design for fire resistance aims to ensure overall dimensions of the section of an element sufficient to keep the heat transfer through this element within acceptable limits, and an average concrete cover to the reinforcement sufficient to keep the temperature of the reinforcement below critical values long enough for the required fire resistance period to be attained. The prediction of spalling – hitherto an imprecise empirical exercise – is now becoming possible with the development of thermohydromechanical nonlinear finite element models capable of predicting pore pressures. The risk of explosive spalling in fire increases with decrease in concrete permeability and could be eliminated by the appropriate inclusion of polypropylene fibres in the mix and/or by protecting the exposed concrete surface with a thermal barrier. There are three methods of assessment of fire resistance: (a) fire testing; (b) prescriptive methods, which are rigid; and (c) performance‐based methods, which are flexible. Performance‐based methods can be classified into three categories of increasing sophistication and complexity: (a) simplified calculations based on limit state analysis; (b) thermomechanical finite element analysis; and (c) comprehensive thermohydromechanical finite element analysis. It is only now that performance‐based methods are being accepted in an increasing number of countries.
Prestressed fibre‐reinforced polymer laminates for strengthening structures
Authors: El‐Hacha R , Wight RG , Green MF 
Published: August 2002

AbstractBonding fibre‐reinforced polymer (FRP) laminates to the surface of a structural component is an effective technique for strengthening structures. The laminates may be used even more efficiently by prestressing the fibre, and this technique has been the focus of recent innovative work. This review focuses on the characteristics of prestressed FRP laminates, the techniques that have been developed, and field applications. Recent strengthening work with non‐prestressed laminates is also summarized.
Isolation of an antimicrobial compound from Impatiens balsamina L. using bioassay‐guided fractionation
Authors: Yang Xiaolong , Summerhurst D. Kristen , Koval Susan F. , Ficker Christine , Smith Myron L. , Bernards Mark A. 
Published: August 2002

AbstractBy using brine shrimp (Artemia salina) lethality test‐guided fractionation, a single bioactive compound (LC50=26 ppm) was isolated from the 95% ethanol extract of the dried aerial parts of Impatiens balsamina L. and subsequently identified as 2‐methoxy‐1,4‐naphthoquinone (MNQ). The structure of MNQ was confirmed by UV, FT‐IR, MS, and 1‐and 2‐D NMR spectroscopy. The antimicrobial activity of MNQ was evaluated using 12 bacterial and eight fungal strains. Five gram‐positive and two gram‐negative bacteria as well as all eight fungi (including multi‐drug resistant strains) tested were highly sensitive to MNQ. A tea prepared according to traditional methods was found to contain sufficient MNQ to account for its antimicrobial properties. Copyright © 2001 John Wiley & Sons, Ltd.
Confidence interval for the mean of non‐normal data
Authors: Wang F. K. 
Published: August 2002

AbstractThe problem of constructing a confidence interval for the mean of non‐normal data is considered. The Bootstrap method and the Box–Cox transformation method of constructing the confidence interval are compared with the normal theory method. Simulation studies are used to evaluate the performance of these different methods of constructing confidence intervals. The result is not surprising; the Bootstrap method is more effective and efficient than the Box–Cox transformation method and the normal theory method in this simulation study. A real example demonstrates the ability of these methods to construct a confidence interval for the mean of audit accounting data. Copyright © 2001 John Wiley & Sons, Ltd.
Investigation of structural and electronic biases in mutagenic compounds
Authors: Llorens Oriol , Perez Juan J. , Villar Hugo O. 
Published: August 2002

AbstractThe use of high throughput screening as the main means to discover lead compounds continues to require the design of libraries for screening. In this work some insights that may permit building chemical libraries that are biased toward compounds that are less likely to be mutagenic are shown. Toward this goal, the study of the distribution of substructural and electronic properties found in compounds that have been reported to be mutagens and nonmutagens is discussed. Mutagenic data retrieved for each of four Salmonella strains, TA‐98, TA‐100, TA‐1535, and TA‐1537, were compiled and divided depending on whether the compounds underwent metabolic activation. For each of the eight compound databases, an exhaustive enumeration of all molecular substructures within it was carried out. Comparison of the fragment distributions in sets of molecules that were Ames positive to a set of compounds found to be negative and vice versa allowed the deduction of moieties that are statistically overrepresented in active versus inactive or inactive versus active compounds for each strain and metabolic state. Our results show that compounds containing nitro functionalities are overrepresented in the Ames test in all strains whether the compounds had been metabolically activated or not. However, presence of a nitro functionality does not ensure that the compounds being Ames positive. Therefore, we computed a series of steric and electronic properties for 270 nitroaromatic compounds using semiempirical techniques. The electron affinity of the compounds offers a statistically significant discrimination between positive and negative compounds. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 88: 107–117, 2002
The complementary roles of molecular surface electrostatic potentials and average local ionization energies with respect to electrophilic processes
Authors: Politzer Peter , Murray Jane S. , Concha Monica C. 
Published: August 2002

AbstractWe focus upon two properties, the electrostatic potential V(r) and the average local ionization energy \documentclass{article}\pagestyle{empty}\begin{document}$\bar{I}(\mathbf{r})$\end{document}. When evaluated on molecular surfaces, VS(r) and \documentclass{article}\pagestyle{empty}\begin{document}$\bar{I}_{S}(\mathbf{r})$\end{document} can be useful tools for analyzing and predicting reactive behavior. VS(r) is most reliable with respect to noncovalent interactions; when electrophilic attack and some degree of charge transfer are involved, then the combination of VS(r) and \documentclass{article}\pagestyle{empty}\begin{document}$\bar{I}_{S}(\mathbf{r})$\end{document} can be quite effective. They play complementary roles: VS(r) reveals the regions of the molecule to which an electrophile would initially be attracted, and \documentclass{article}\pagestyle{empty}\begin{document}$\bar{I}_{S}(\mathbf{r})$\end{document} indicates the ease of charge transfer at these and other sites. Four examples of such complementarity are discussed, involving benzene derivatives, guanine and cytosine, furan and pyrrole, and binary hydrides. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Chromatofocusing nonporous reversed‐phase high‐performance liquid chromatography/electrospray ionization time‐of‐flight mass spectrometry of proteins from human breast cancer whole cell lysates: a novel two‐dimensional liquid chromatography/mass spectrometry method
Authors: Chong Bathsheba E. , Yan Fang , Lubman David M. , Miller Fred R. 
Published: August 2002

AbstractA novel two‐dimensional two‐column liquid chromatography/mass spectrometry (LC/MS) technique is described in this work, where chromatofocusing (CF) has been coupled to nonporous reversed‐phase (NPS‐RP) HPLC to separate proteins from human breast epithelial whole cell lysates. The liquid fractions from NPS‐RP‐HPLC are readily amenable to direct on‐line analysis using electrospray ionization orthogonal acceleration time‐of‐flight mass spectrometry (ESI‐TOFMS). A key advantage of this technique is that proteins can be ‘peeled off’ in the liquid phase from the CF column according to their isoelectric points (pI) in the first chromatographic separation dimension. The NPS‐RP‐HPLC column further separates thesepI‐focused fractions based upon protein hydrophobicity as the second chromatographic dimension. The third dimension involves on‐line molecular weight determination using ESI‐TOFMS. As a result, this method has the potential to be fully automated. In addition, a 2‐D protein map ofpIversus molecular weight is generated, which is analogous to a 2‐D gel image. Thus, this technique may provide a means to study differential expression of proteins from whole cell lysates. Copyright © 2001 John Wiley & Sons, Ltd.
Referencing strategies and techniques in stable isotope ratio analysis
Authors: Werner Roland A. , Brand Willi A. 
Published: August 2002

AbstractStable isotope ratios are reported in the literature in terms of a deviation from an international standard (δ‐values). The referencing procedures, however, differ from instrument to instrument and are not consistent between measurement facilities. This paper reviews an attempt to unify the strategy for referencing isotopic measurements. In particular, emphasis is given to the importance of identical treatment of sample and reference material (‘IT principle’), which should guide all isotope ratio determinations and evaluations. The implementation of the principle in our laboratory, the monitoring of our measurement quality, the status of the international scales and reference materials and necessary correction procedures are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of phenolic compounds in rose hip (Rosa canina) using liquid chromatography coupled to electrospray ionisation tandem mass spectrometry and diode‐array detection
Authors: Hvattum Erlend 
Published: August 2002

AbstractLiquid chromatography coupled with negative and positive electrospray ionisation (ESI) tandem mass spectrometry (MS/MS) and diode‐array detection (DAD) was used for determination of phenols in rose hip (Rosa canina) extract. ESI mass spectra of the chromatographically separated phenols gave the molecular weight of the compounds through prominent [M − H]− ions for most of the compounds and M+ ions for the anthocyanins. Collision induced dissociation (CID) of the [M − H]− (or M+) precursor ions yielded product ions which determined the molecular weight of the aglycones. In‐source fragmentation followed by CID of the resulting deprotonated aglycone ([A − H]−) provided product ions for the identification of the unconjugated phenols. The identification was based on comparison with product ion spectra of commercial standards. UV‐diode‐array spectra were used for identity confirmation. This combined approach allowed the identification in rose hip extract of an anthocyanin, i.e. cyanidin‐3‐O‐glucoside, several glycosides of quercetin and glycosides of taxifolin and eriodictyol. Phloridzin was identified, and several conjugates of methyl gallate were also found, one of which was tentatively identified as methyl gallate‐rutinoside. Catechin and quercetin were found as the aglycones in the extract. Copyright © 2002 John Wiley & Sons, Ltd.
Forensic identification of explosive oxidizers by electrospray ionization mass spectrometry
Authors: Zhao Xiaoming , Yinon Jehuda 
Published: August 2002

AbstractThe mass spectrometry of a group of inorganic oxidizers was studied using the electrospray ionization technique. It was found that a series of cluster ions were predominant in both positive‐ and negative‐ion mode, allowing for the characterization of the investigated oxidizers. The identity of the recorded cluster ions was further confirmed by using some isotopically labeled compounds and tandem mass spectrometry with collision‐induced dissociation. The use of electrospray ionization mass spectrometry for positive identification of major oxidizer components in explosive formulations was demonstrated by three samples of forensic interest. Copyright © 2002 John Wiley & Sons, Ltd.
Borna disease virus
Authors: Jordan Ingo , Lipkin W. Ian 
Published: August 2002

AbstractBorna disease virus (BDV) is unique amongst animal RNA viruses in its molecular biology and capacity to cause persistent, noncytolytic CNS‐infection in a wide variety of host species. Unlike other non‐segmented negative‐strand RNA animal viruses, BDV replicates in the nucleus of the host cell where splicing is employed for expression of a very compact genome. Epidemiological studies indicate a broad host range and geographical distribution, and some investigators have proposed that human infection may result in neuropsychiatric disorders. Experimental Borna disease in neonatal and adult rats provides an intriguing model for immune‐mediated disturbances of brain development and function. Copyright © 2001 John Wiley & Sons, Ltd.
Antiviral agents active against human herpesviruses HHV‐6, HHV‐7 and HHV‐8
Authors: De Clercq Erik , Naesens Lieve , De Bolle Leen , Schols Dominique , Zhang Ying , Neyts Johan 
Published: August 2002

AbstractA series of antiviral compounds were examined for their activity against human herpesvirus type 6 (HHV‐6), type 7 (HHV‐7) and type 8 (HHV‐8). They were selected either because they are already approved for clinical use in the treatment of herpesvirus infections (acyclovir, valaciclovir, penciclovir, famciclovir, ganciclovir, brivudin, foscarnet and cidofovir) or have demonstrated marked activity against herpesviruses (lobucavir, H2G, A‒5021, D/L‐cyclohexenyl G and S2242). In view of their host cell specificity, different cells and assays had to be used for determining antiviral activity against these three viruses. The most potent compounds with the highest antiviral selectivity index were: (i) for HHV‐6; foscarnet, S2242, A‐5021 and cidofovir; (ii) for HHV‐7; S2242, cidofovir and foscarnet; and (iii) for HHV‐8; S2242, cidofovir and ganciclovir. As mycophenolic acid has been shown to enhance significantly the activity of acyclic guanosine analogues (such as acyclovir, penciclovir and ganciclovir) in vitro against HSV‐1, HSV‐2, VZV and HCMV, it would seem worth evaluating whether mycophenolic acid also potentiates the activity of these acyclic guanosine analogues against HHV‐6, ‐7 and ‐8. Copyright © 2001 John Wiley & Sons, Ltd.