bluuebunny/crossref_metadata_2025_split huggingface dataset:
Costs and predictors of costs in rheumatoid arthritis: A prevalence‐based study
Authors: Lajas Cristina , Abasolo Lydia , Bellajdel Boutayeb , Hernández‐García César , Carmona Loreto , Vargas Emilio , Lázaro Pablo , Jover Juan A. 
Published: February 2003

AbstractObjectiveTo analyze the annual cost of rheumatoid arthritis (RA) and its predictive factors.MethodsData were obtained from a 12‐month retrospective cohort of 201 RA patients, randomly selected from a rheumatology registry, through a structured interview and records of the Central Information System of the hospital. Results were divided into direct, indirect, and total costs in 2001 US dollars. A sensitivity analysis was performed. Multiple linear regression models for the different types of costs were carried out.ResultsThe total cost was $2.2 million per year, with a cost attributable to RA of $2.07 million per year. The average cost per patient was $10,419 per year (ranging from $7,914 per patient per year in the best scenario to $12,922 per patient per year in the worst case). Direct costs represent nearly 70% of total costs. We found an average increment in total costs of $11,184 per year per unit of Health Assessment Questionnaire (HAQ) score (P < 0.0001) and an average annual increment of $621 per year of disease (P < 0.0001). After adjustment, the HAQ score, inability to perform housework tasks, and being permanently disabled for work were the only predictors of high costs.ConclusionOur data show a remarkable economic impact of RA over society and link the costs of the disease to its consequences in terms of functional disability, work disability, and housework disability.
Preoperative predictors of locomotor ability two months after total knee arthroplasty for severe osteoarthritis
Authors: Parent Éric , Moffet Hélène 
Published: February 2003

AbstractObjectiveTo identify preoperative predictors of locomotor ability 2 months after total knee arthroplasty (TKA).MethodsSixty‐five participants scheduled for a first TKA were recruited. The dependent variable was the distance covered during the 6‐minute gait test 2 months after TKA. The independent variables, measured before surgery, were grouped into 3 categories: 1) personal; 2) organic system, and 3) capability variables. Multiple regression analyses were conducted to determine the best predictors of the dependent variable. Modified cross‐validation of the model combining predictors from the three categories was obtained with 10 random samples derived from the original cohort by resampling with replacement.ResultsPredictors were identified in the 3 categories: 1) gender, number of comorbidities, body mass index, 2) knee pain, flexion and strength, lower limb mechanical power, and 3) preoperative 6‐minute gait distance. When these variables were modeled together only the preoperative 6‐minute gait distance and knee pain and flexion remained significant (adjusted R2= 0.66).ConclusionUsing variables easily measured before surgery, it is possible to predict with good accuracy locomotor ability 2 months after TKA.
Isometric muscle force measurement for clinicians treating patients with osteoarthritis of the knee
Authors: Fransen Marlene , Crosbie Jack , Edmonds John 
Published: February 2003

AbstractObjectiveTo evaluate the discriminant validity and, for clinicians, the test–retest reliability of isometric force in patients with knee osteoarthritis (OA).MethodsMean isometric muscle strength data collected for 113 patients with knee OA were compared with published normative data for 131 asymptomatic subjects.ResultsPatients with knee OA, ages 60–79 years, could attain only 40–53% of the knee extensor force and 35–46% of the knee flexor force generated by their age‐ and sex‐matched peers. One‐week test–retest intraclass correlations ranged from 0.79 to 0.95. Random measurement error demonstrated a favorable “signal‐to‐noise” ratio.ConclusionThe similar decrease in knee extensor and knee flexor strength demonstrated by patients with knee OA compared with their age‐ and sex‐matched asymptomatic peers suggests that strategies should be directed at both muscle groups to optimally limit joint damage. Isometric muscle force measurement can be a useful assessment tool for clinicians.
Use of complementary and alternative medicine by pediatric rheumatology patients
Authors: Hagen Lorrie E. M. , Schneider Rayfel , Stephens Derek , Modrusan Diana , Feldman Brian M. 
Published: February 2003

AbstractObjectiveTo assess how often the patients in The Hospital for Sick Children's rheumatology clinic use complementary and alternative medicine (CAM), and the type of CAM used.MethodsCross‐sectional descriptive survey study in a tertiary care referral center.ResultsWe found that 90 (64%) of 141 respondents used at least 1 form of CAM; 45 (50%) of these 90 used more than 1 form. Duration of illness was positively associated with the use of CAM; the difference in the mean length of illness between users (4.12 ± 3.60 years) and nonusers (2.82 ± 3.23 years) was 1.3 years (P = 0.04). Of the 41 respondents with more than 1 illness, 32 used CAM, compared with 57 of 96 who had only 1 illness (P = 0.036).ConclusionHealth care providers must be aware of their patients' possible use of CAM, especially those with more than 1 illness.
Gaussian docking functions
Authors: McGann Mark R. , Almond Harold R. , Nicholls Anthony , Grant J. Andrew , Brown Frank K. 
Published: February 2003

AbstractA shape‐based Gaussian docking function is constructed which uses Gaussian functions to represent the shapes of individual atoms. A set of 20 trypsin ligand–protein complexes are drawn from the Protein Data Bank (PDB), the ligands are separated from the proteins, and then are docked back into the active sites using numerical optimization of this function. It is found that by employing this docking function, quasi‐Newton optimization is capable of moving ligands great distances [on average 7 Å root mean square distance (RMSD)] to locate the correctly docked structure. It is also found that a ligand drawn from one PDB file can be docked into a trypsin structure drawn from any of the trypsin PDB files. This implies that this scoring function is not limited to more accurate x‐ray structures, as is the case for many of the conventional docking methods, but could be extended to homology models. © 2002 Wiley Periodicals, Inc. Biopolymers 68: 76–90, 2003
The relaxed complex method: Accommodating receptor flexibility for drug design with an improved scoring scheme
Authors: Lin Jung‐Hsin , Perryman Alexander L. , Schames Julie R. , McCammon J. Andrew 
Published: February 2003

AbstractAn extension of the new computational methodology for drug design, the “relaxed complex” method (J.‐H. Lin, A. L. Perryman, J. R. Schames, and J. A. McCammon, Journal of the American Chemical Society, 2002, vol. 24, pp. 5632–5633), which accommodates receptor flexibility, is described. This relaxed complex method recognizes that ligand may bind to conformations that occur only rarely in the dynamics of the receptor. We have shown that the ligand–enzyme binding modes are very sensitive to the enzyme conformations, and our approach is capable of finding the best ligand enzyme complexes. Rapid docking serves as an efficient initial filtering method to screen a myriad of docking modes to a limited set, and it is then followed by more accurate scoring with the MM/PBSA (Molecular Mechanics/Poisson Boltzmann Surface Area) approach to find the best ligand–receptor complexes. The MM/PBSA scorings consistently indicate that the calculated binding modes that are most similar to those observed in the x‐ray crystallographic complexes are the ones with the lowest free energies. © 2002 Wiley Periodicals, Inc. Biopolymers 68: 47–62, 2003
Atomistic protein folding simulations on the submillisecond time scale using worldwide distributed computing
Authors: Pande Vijay S. , Baker Ian , Chapman Jarrod , Elmer Sidney P. , Khaliq Siraj , Larson Stefan M. , Rhee Young Min , Shirts Michael R. , Snow Christopher D. , Sorin Eric J. , Zagrovic Bojan 
Published: February 2003

AbstractAtomistic simulations of protein folding have the potential to be a great complement to experimental studies, but have been severely limited by the time scales accessible with current computer hardware and algorithms. By employing a worldwide distributed computing network of tens of thousands of PCs and algorithms designed to efficiently utilize this new many‐processor, highly heterogeneous, loosely coupled distributed computing paradigm, we have been able to simulate hundreds of microseconds of atomistic molecular dynamics. This has allowed us to directly simulate the folding mechanism and to accurately predict the folding rate of several fast‐folding proteins and polymers, including a nonbiological helix, polypeptide α‐helices, a β‐hairpin, and a three‐helix bundle protein from the villin headpiece. Our results demonstrate that one can reach the time scales needed to simulate fast folding using distributed computing, and that potential sets used to describe interatomic interactions are sufficiently accurate to reach the folded state with experimentally validated rates, at least for small proteins. © 2002 Wiley Periodicals, Inc. Biopolymers 68: 91–109, 2003
Condensation heat transfer on tubes in actual flue gas (Parametric study for condensation behavior)
Authors: Osakabe Masahiro , Yagi Kiyoyuki , Itoh Tsugue , Ohmasa Kunimitsu 
Published: February 2003

AbstractIn order to improve boiler efficiency, latent heat recovery from the flue gas is a very important concept. Condensation heat transfer on horizontal tubes was investigated experimentally by using flue gas from a natural gas boiler. The parametric studies concerning the effects of tube stages, gas velocities, SO2 in the flue gas, and Teflon‐lined tubes were conducted at a wide range of tube surface temperature. The heat transfer was enhanced at the second stage due to the wake turbulence of the first stage. No significant decrease of the condensation in the second stage due to the condensate falling from the first stage could be observed. Even at the high gas velocity condition, the condensation pattern was similar to that observed in previous low gas velocity experiments. The effect of SO2 in the flue gas on the condensation behavior could not be observed. The heat and mass transfer behaviors on stainless‐steel and Teflon‐lined surfaces were well predicted with the analogy correlation. The above results suggested that the heat and mass transfer were dominated by the convection and diffusion process on the gas side. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(2): 153–166, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10079
Study of thermal characteristics of bubble‐driven heat‐transport device
Authors: Nishio Shigefumi , Nagata Shin‐ichi , Numata Shohei , Shirakashi Ryo 
Published: February 2003

AbstractIn the present paper, we report on heat transport rates and fluid flow patterns of a bubble‐driven heat‐transport device (BD‐HTD) made of glass, obtained with the working fluids water, soapsuds, ethanol, and R141b. In this type of HTD, the cooling and heating sections are connected to each other by a closed loop of tube meandering between them, and the loop is filled to a certain volume fraction with a working fluid. The present BD‐HTD was set vertically and was heated at the bottom by warm water and cooled at the top by cold water. Experimental parameters were the inner diameter of the tube (D = 1.8, 2.4, 5.0 mm), the total temperature difference of heating and cooling water (ΔT = 20 to 60 K), and liquid volume fraction (α = 18 to 98%). The main results are summarized as follows. Heat transfer coefficient of the working fluid at the heating and cooling sections, hfi, is not strongly dependent on α and ΔT. Among the present test liquids, the effective thermal conductivity kef is the highest for R141b, but the heat transfer coefficient hfi is the highest for water. As kef is sufficiently high even for water, the heat transport rate Q is the highest for water. Q of the present BD‐HTD using water can exceed the maximum heat transport rate of conventional heat pipes of the same geometry. For R141b, the BD‐HTD operated for D/λ0 = 1.5 to 4.2 (λ0: the capillary length) and Q is not strongly dependent on the tube diameter. This result indicates that BD‐HTDs are suitable for micro‐HTDs, but the BD‐HTD did not operate with water at D/λ0 = 0.65. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(2): 167–177, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10082
Differentiation of a pair of diastereomeric tertiarybutoxycarbonylprolylproline ethyl esters by collision‐induced dissociation of sodium adduct ions in electrospray ionization mass spectrometry and evidence for chiral recognition by ab initio molecular orbital calculations
Authors: Tsunematsu Hideaki , Ikeda Hirohito , Hanazono Hiroshi , Inagaki Masanori , Isobe Ryuichi , Higuchi Ryuichi , Goto Yoshinobu , Yamamoto Magobei 
Published: February 2003

AbstractThe fragmentation of the sodium adduct ions for tert‐butoxycarbonyl‐L‐prolyl‐L‐proline ethyl ester (Boc‐L‐Pro‐L‐Pro‐OEt) was compared with that for Boc‐D‐Pro‐L‐Pro‐OEt in positive‐ion electrospray ionization (ESI) mass spectrometry. In the collision‐induced dissociation (CID) mass spectra of the [M + Na]+ ions, the abundance of the [M + Na − C(CH3)3 + H]+ ion, which is due to the loss of a tert‐butyl group from the [M + Na]+ ion for Boc‐D‐Pro‐L‐Pro‐OEt, was about eight times higher than that for Boc‐L‐Pro‐L‐Pro‐OEt. In addition, in the CID spectra of the sodium adduct fragment ion ([M + Na − Boc + H]+), the abundance of the [M + Na − Boc − prolylresidue + H]+ ion, which is due to the loss of prolyl residue from the [M + Na − Boc + H]+ ion for Boc‐L‐Pro‐L‐Pro‐OEt, was about five times higher than that for Boc‐D‐Pro‐L‐Pro‐OEt. These results indicate that Boc‐L‐Pro‐L‐Pro‐OEt was distinguished from Boc‐D‐Pro‐L‐Pro‐OEt by the CID mass spectra of the sodium adduct ions in ESI mass spectrometry. The optimized geometries of the [M + Na]+ and the [M + Na − Boc + H]+ ions calculated by ab initio molecular orbital calculations suggest that the chiral recognition of these diastereomers was due to the difference of the orientation of a sodium ion to the oxygen and nitrogen atoms in dipeptide derivatives, and to the difference of the total energies between them. Copyright © 2003 John Wiley & Sons, Ltd.
Deconvolution of mass spectra measuredwith a non‐uniform detector array to give accurate ion abundances
Authors: Birkinshaw K. 
Published: February 2003

AbstractArray detectors are under active development since they offer large improvements in the efficiency of mass spectrum measurements. High quality is always a requirement whether array detectors are used for ions, electrons, UV, x‐rays, etc., but in mass spectrometry the very high accuracy frequently needed in ion abundance measurements for isotope ratios is unique. These demands necessitate modelling the measurement process and careful deconvolution of the measured data. A linear model in terms of matrix algebra is presented in which the incident spectrum (unknown) and the measured spectrum are represented by column matrices and the action of the detector array on the incident spectrum is represented by an experimentally measurable square ‘A’ matrix. Residual noise in this matrix can be minimized following a singular value decomposition procedure and its use in ‘forward deconvolution’ of measured spectra is discussed. The random error in the incident ion counts is accounted for after the deconvolution since this is not an error from the perspective of the detector. The microchannel plate electron multiplier gain distribution is an important feature of the deconvolution. Copyright © 2003 John Wiley & Sons, Ltd.
Addressing the metabolic activation potential of new leads in drug discovery: a case study using ion trap mass spectrometry and tritium labeling techniques
Authors: Samuel Koppara , Yin Wenji , Stearns Ralph A. , Tang Yui S. , Chaudhary Ashok G. , Jewell James P. , Lanza Thomas , Lin Linus S. , Hagmann William K. , Evans David C. , Kumar Sanjeev 
Published: February 2003

AbstractMetabolic activation of drug candidates to electrophilic reactive metabolites that can covalently modify cellular macromolecules may result in acute and/or idiosyncratic immune system‐mediated toxicities in humans. This presents a significant potential liability for the future development of these compounds as safe therapeutic agents. We present here an example of an approach where sites of metabolic activation within a new drug candidate series were rapidly identified using online liquid chromatography/multi‐stage mass spectrometry on an ion trap mass spectrometer. This was accomplished by trapping the reactive intermediates formed upon incubation of compounds with rat and human liver microsomes as their corresponding glutathione conjugates and mass spectral characterization of these thiol adducts. Based on the structures of the GSH adducts identified, potential sites and mechanisms of bioactivation within the chemical structure were proposed. These metabolism studies were interfaced with iterative structural modifications of the chemical series in order to block these bioactivation sites within the molecule. This strategy led to a significant reduction in the propensity of the compounds to undergo metabolic activation as evidenced by reductions in the irreversible binding of radioactivity to liver microsomal material upon incubation of tritium‐labeled compounds with this in vitro system. With the efficiency and throughput achievable with such an approach, it appears feasible to identify and address the metabolic activation potential of new drug leads during routine metabolite identification studies in an early drug discovery setting. Copyright © 2003 John Wiley & Sons, Ltd.
Adiabatic RARE imaging
Authors: de Graaf Robin A. , Rothman Douglas L. , Behar Kevin L. 
Published: February 2003

AbstractThe practical implementation of ultra‐fast spin‐echo, or RARE imaging with adiabatic RF pulses and surface coil transmission at 7 T is described. Despite the large RF inhomogeneities, the adiabatic character of the 180° BIR‐4 refocusing pulses ensures optimal sensitivity and minimal image artifacts. An internal ‘phase‐cycle’ is used to remove spurious unwanted coherences. The short T2 relaxation times in rat brain at 7 T demand a centric, rather than a linear coverage of k‐space in order to avoid excessive signal loss. T2 relaxation during k‐space coverage also leads to image blurring, which can be counteracted by interleaved k‐space sampling. The coverage of k‐space in four acquisitions provides high‐quality anatomical images comparable to conventional spin‐echo images. A two‐scan RARE implementation provides sufficient spatial and temporal resolution for most applications. Quantitative mapping of T1 relaxation and cerebral blood flow changes during forepaw stimulation in the rat are demonstrated. Copyright © 2003 John Wiley & Sons, Ltd.
Folding in lipid membranes (FILM): A novel method for the prediction of small membrane protein 3D structures
Authors: Pellegrini‐Calace M. , Carotti A. , Jones D. T. 
Published: February 2003

AbstractWe present the results of applying a novel knowledge‐based method (FILM) to the prediction of small membrane protein structures. The basis of the method is the addition of a membrane potential to the energy terms (pairwise, solvation, steric, and hydrogen bonding) of a previously developed ab initio technique for the prediction of tertiary structure of globular proteins (FRAGFOLD). The method is based on the assembly of supersecondary structural fragments taken from a library of highly resolved protein structures using a standard simulated annealing algorithm. The membrane potential has been derived by the statistical analysis of a data set made of 640 transmembrane helices with experimentally defined topology and belonging to 133 proteins extracted from the SWISS‐PROT database. Results obtained by applying the method to small membrane proteins of known 3D structure show that the method is able to predict, at a reasonable accuracy level, both the helix topology and the conformations of these proteins. Proteins 2003;50:537–545. © 2003 Wiley‐Liss, Inc.
A path from primary protein sequence to ligand recognition
Authors: Kho Richard , Baker Brian L. , Newman Joseph V. , Jack Richard M. , Sem Daniel S. , Villar Hugo O. , Hansen Mark R. 
Published: February 2003

AbstractA novel method to organize protein structural information based solely on sequence is presented. The method clusters proteins into families that correlate with the three‐dimensional protein structure and the conformation of the bound ligands. This procedure was applied to nicotinamide adenine dinucleotide [NAD(P)]‐utilizing enzymes to identify a total of 94 sequence families, 53 of which are structurally characterized. Each of the structurally characterized proteins within a sequence family correlates to a single protein fold and to a common bound conformation of NAD(P). A wide range of structural folds is identified that recognize NAD(P), including Rossmann folds and β/α barrels. The defined sequence families can be used to identify the type and prevalence of NAD(P)‐utilizing enzymes in the proteomes of sequenced organisms. The proteome of Mycobacterium tuberculosis was mined to generate a proteome‐wide profile of NAD(P)‐utilizing enzymes coded by this organism. This enzyme family comprises approximately 6% of the open reading frames, with the largest subgroup being the Rossmann fold, short‐chain dehydrogenases. The preponderance of short‐chain dehydrogenases correlates strongly with the phenotype of M. tuberculosis, which is characterized as having one of the most complex prokaryotic cell walls. Proteins 2003;50:589–599. © 2003 Wiley‐Liss, Inc.
D‐amino acid residues in peptides and proteins
Authors: Mitchell John B.O. , Smith James 
Published: February 2003

AbstractWe have investigated the D‐amino acid residues present in Protein Data Bank (PDB) entries, categorizing them into “real” D‐residues and artifacts. In polypeptide chains of more than 20 residues, only a single instance of a “real” D‐residue, other than those deliberately designed or engineered, was found. This example was the result of a slow chemical epimerization process. Another 12 designed D‐residues were found in these longer polypeptide chains. Smaller peptides of 20 or fewer residues contained 479 “real” D‐residues, the majority in various gramicidin, actinomycin, or cyclosporin structures. We found 148 PDB entries with “real” D‐residues and a further 186, in which all apparent D‐residues are artifacts. Investigating the (ϕ, ψ) preferences of the “real” D‐residues, we found that the region around (−60°, −45°) was almost completely unoccupied, even though it is not formally disallowed. We link the low propensity to occupy this region with the α‐helix destabilizing properties of D‐residues. Proteins 2003;50:563–571. © 2003 Wiley‐Liss, Inc.