bluuebunny/crossref_metadata_2025_split huggingface dataset:
New acrylic bone cements conjugated to vitamin E: Curing parameters, properties, and biocompatibility
Authors: Méndez J.A. , Aguilar M.R. , Abraham G.A. , Vázquez B. , Dalby M. , Di Silvio L. , San Román J. 
Published: October 2002

AbstractAcrylic bone cement formulations with antioxidant character were prepared by incorporation of a methacrylic monomer derived from vitamin E (MVE). Increasing concentrations of this monomer provided decreasing peak temperature values, ranging from 62 to 36°C, and increasing setting time with values between 17 and 25 min. Mechanical properties were evaluated by compression and tension tests. Compressive strength of the new formulations were superior to 70 MPa in all cases. The cement containing 25 wt % MVE, however, showed a significant decrease in tensile properties. Biocompatibility of the new formulations was studied in vitro. The analysis of the effect of leachables from cements into the media showed continued cell proliferation and cell viability with a significant increase for the cement containing 15 wt % MVE. This formulation also showed a significant increase in cellular proliferation over a period of 7 days as indicated by the Alamar Blue test. The cells were able to differentiate and express phenotypical markers in presence of all materials. A significant increase in alkaline phosphatase activity was observed on the cements prepared in presence of 15–25 wt % MVE compared with PMMA. Morphological assessment showed that the human osteoblast (HOB) cells were able to adhere, retain their morphology, and proliferate on all the cements. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 299–307, 2002
Web‐Based Contracts: You Could Be Burned!
Authors: Durtschi Cindy , Hillison William , Pacini Carl 
Published: October 2002

AbstractThe Internet is the new Wild West for companies venturing into Web‐based commerce. Someone can consent

to complex electronic agreements with a simple mouse click. But what must you know so you don't get

burned? © 2002 Wiley Periodicals, Inc.
Differential regulation of Cbfa1/Runx2 and osteocalcin gene expression by vitamin‐D3, dexamethasone, and local growth factors in primary human osteoblasts
Authors: Viereck Volker , Siggelkow Heide , Tauber Simone , Raddatz Dirk , Schutze Norbert , Hüfner Michael 
Published: October 2002

AbstractCore binding factor alpha 1 (Cbfa1) is an osteoblast‐specific transcription factor essential to develop a mature osteoblast phenotype. However, its exact role in the signaling of various osteotropic‐differentiating agents is still unclear. In this study, we assessed the effects of 1,25‐(OH)2‐D3 (D3), ascorbic acid, bone morphogenetic protein‐2 (BMP‐2), dexamethasone (Dex), and transforming growth factor‐β (TGF‐β) on Cbfa1 and osteocalcin (OCN) mRNA steady state levels (by semiquantitative RT‐PCR) in an in vitro model of osteoblast differentiation. TGF‐β increased Cbfa1 mRNA levels in normal primary human osteoblasts (pHOB) by 2.6‐fold in a time‐dependent fashion with maximum effect on day 28 (P < 0.001). Similarly, the glucocorticoid Dex enhanced Cbfa1 gene expression by pHOB in a time‐dependent fashion by up to 4.6‐fold (P < 0.001). In contrast, Dex inhibited OCN gene expression levels by 68% (P < 0.01). Treatment with BMP‐2 resulted in an earlier enhancement of Cbfa1 and led to a 4.2‐fold increase with a maximum on day 21 (P < 0.001). Ascorbic acid did not modulate Cbfa1 and OCN gene expression. The effect of vitamin D (D3) on Cbfa1 mRNA expression was influenced by the duration of treatment, being inhibitory after 1 h and having a stimulatory effect after 48 h. Time course experiments indicated a stimulatory effect of D3 on Cbfa1 mRNA levels (by 2.5‐fold after 48 h; P < 0.01). Analysis of the late cellular differentiation marker osteocalcin revealed that D3 increased OCN gene expression by 14‐fold (P < 0.001). In conclusion, in normal primary human osteoblasts, the rapid and pronounced increase of OCN after treatment with D3 seems not to be mediated by Cbfa1. These data imply that Cbfa1 gene expression is differentially regulated by various osteoblastic differentiating agents and is dependent on the stage of maturation. J. Cell. Biochem. 86: 348–356, 2002. © 2002 Wiley‐Liss, Inc.
Linear scaling local correlation approach for solving the coupled cluster equations of large systems
Authors: Li Shuhua , Ma Jing , Jiang Yuansheng 
Published: October 2002

AbstractA linear scaling local correlation approach is proposed for approximately solving the coupled cluster doubles (CCD) equations of large systems in a basis of orthogonal localized molecular orbitals (LMOs). By restricting double excitations from spatially close occupied LMOs into their associated virtual LMOs, the number of significant excitation amplitudes scales only linearly with molecular size in large molecules. Significant amplitudes are obtained to a very good approximation by solving the CCD equations of various subsystems, each of which is made up of a cluster associated with the orbital indices of a subset of significant amplitudes and the local environmental domain of the cluster. The combined effect of these two approximations leads to a linear scaling algorithm for large systems. By using typical thresholds, which are designed to target an energy accuracy, our numerical calculations for a wide range of molecules using the 6‐31G or 6‐31G* basis set demonstrate that the present local correlation approach recovers more than 98.5% of the conventional CCD correlation energy. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 237–244, 2002
Structure and dynamics of liquid water with different long‐range interaction truncation and temperature control methods in molecular dynamics simulations
Authors: Mark Pekka , Nilsson Lennart 
Published: October 2002

AbstractWe have used molecular dynamics simulations to study the physical properties of modified TIP3P water model included in the CHARMM program, using four different methods—the Ewald summation technique, and three different spherical truncation methods—for the treatment of the long‐range interactions. Both the structure and dynamics of the liquid water model were affected by the methods used to truncate the long‐range interactions. For some of the methods artificial structuring of the model liquid was observed around the cutoff radius. The model liquid properties were also affected by the commonly applied temperature control methods. Four different methods for controlling the temperature of the system were studied, and the effects of these methods on the bulk properties for liquid water were analyzed. The system size was also found to change the dynamics of the model liquid water. Two control simulations with the SPC/E water model were carried out. The self‐diffusion coefficient (D), the radial distribution function (gOO), the distance dependent Kirkwood G‐factor [Gk(r)] and the intermolecular potential energy (Epot) were determined from the different trajectories and compared with the experimental data. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1211–1219, 2002
Accelerated Poisson–Boltzmann calculations for static and dynamic systems
Authors: Luo Ray , David Laurent , Gilson Michael K. 
Published: October 2002

AbstractWe report here an efficient implementation of the finite difference Poisson–Boltzmann solvent model based on the Modified Incomplete Cholsky Conjugate Gradient algorithm, which gives rather impressive performance for both static and dynamic systems. This is achieved by implementing the algorithm with Eisenstat's two optimizations, utilizing the electrostatic update in simulations, and applying prudent approximations, including: relaxing the convergence criterion, not updating Poisson–Boltzmann‐related forces every step, and using electrostatic focusing. It is also possible to markedly accelerate the supporting routines that are used to set up the calculations and to obtain energies and forces. The resulting finite difference Poisson–Boltzmann method delivers efficiency comparable to the distance‐dependent dielectric model for a system tested, HIV Protease, making it a strong candidate for solution‐phase molecular dynamics simulations. Further, the finite difference method includes all intrasolute electrostatic interactions, whereas the distance dependent dielectric calculations use a 15‐Å cutoff. The speed of our numerical finite difference method is comparable to that of the pair‐wise Generalized Born approximation to the Poisson–Boltzmann method. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1244–1253, 2002
Derivation of class II force fields. VIII. Derivation of a general quantum mechanical force field for organic compounds
Authors: Ewig Carl S. , Berry Rajiv , Dinur Uri , Hill Jörg‐Rüdiger , Hwang Ming‐Jing , Li Haiying , Liang Chris , Maple Jon , Peng Zhengwei , Stockfisch Thomas P. , Thacher Thomas S. , Yan Lisa , Ni Xiangshan , Hagler Arnold T. 
Published: October 2002

AbstractA class II valence force field covering a broad range of organic molecules has been derived employing ab initio quantum mechanical “observables.” The procedure includes selecting representative molecules and molecular structures, and systematically sampling their energy surfaces as described by energies and energy first and second derivatives with respect to molecular deformations. In this article the procedure for fitting the force field parameters to these energies and energy derivatives is briefly reviewed. The application of the methodology to the derivation of a class II quantum mechanical force field (QMFF) for 32 organic functional groups is then described. A training set of 400 molecules spanning the 32 functional groups was used to parameterize the force field. The molecular families comprising the functional groups and, within each family, the torsional angles used to sample different conformers, are described. The number of stationary points (equilibria and transition states) for these molecules is given for each functional group. This set contains 1324 stationary structures, with 718 minimum energy structures and 606 transition states. The quality of the fit to the quantum data is gauged based on the deviations between the ab initio and force field energies and energy derivatives. The accuracy with which the QMFF reproduces the ab initio molecular bond lengths, bond angles, torsional angles, vibrational frequencies, and conformational energies is then given for each functional group. Consistently good accuracy is found for these computed properties for the various types of molecules. This demonstrates that the methodology is broadly applicable for the derivation of force field parameters across widely differing types of molecular structures. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1782–1800, 2001
Diagnosing complicated grief: A closer look
Authors: Enright Brian P. , Marwit Samuel J. 
Published: October 2002

AbstractOver the past decade, a number of researchers have proposed a separate DSM category for complicated grief. Recently, there have been attempts to determine empirically the number and nature of variables comprising the complicated‐grief syndrome. The present research addresses one such procedure for defining these variables. Combining a past methodology that demonstrated the relative utility of one classification of complicated grief (Worden, 1991) with dimensional concepts derived from other classifications, the present research concludes that a relatively small number of variables account for the concept. These findings are discussed not only in terms of previous research on Worden's categorization and more recent classifications, but, more importantly, in terms of the more global theoretical and methodological issues surrounding the definition(s) of complicated grief. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 747‐757, 2002.
Remission, recovery, relapse, and recurrence in eating disorders: Conceptualization and illustration of a validation strategy
Authors: Kordy Hans , Krämer Beatrice , Palmer Robert L. , Papezova Hana , Pellet Jacques , Richard Matthias , Treasure Janet , COST Action B6  
Published: October 2002

AbstractIn a consensus‐building process a group of experts from 19 European countries (COST Action B6) adapted the terms partial and full remission, relapse, recovery, and recurrence according to principles described by Frank et al. for depression. The empirical validity of the operationalizations was illustrated by longitudinal data on the post treatment course of 233 anorectic and 422 bulimic patients (diagnosed according to DSM‐IIIR) from the German Project TR‐EAT. These data were collected 2.5 years after admission using the Longitudinal Interval Follow‐up Evaluation (LIFE) and statistically explored by survival‐analysis. It was demonstrated that these consensus definitions measure what they intend to measure. They open a longitudinal perspective in that one can learn not only whether, but also when and with what probability patients change for the better or worse. Data suggest that persistence of symptom improvement has different implications for anorexia and bulimia nervosa. For example, relapse prevention would be most beneficial for bulimic patients for about 4 months after key symptoms remit, while this would be of less importance for anorexic patients. It is discussed whether and how this longitudinal approach can contribute to an empirically based rationale for targeted and individualized treatment. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 833–846, 2002
Cellular response to oxidative stress: Signaling for suicide and survival*
Authors: Martindale Jennifer L. , Holbrook Nikki J. 
Published: October 2002

AbstractReactive oxygen species (ROS), whether produced endogenously as a consequence of normal cell functions or derived from external sources, pose a constant threat to cells living in an aerobic environment as they can result in severe damage to DNA, protein, and lipids. The importance of oxidative damage to the pathogenesis of many diseases as well as to degenerative processes of aging has becoming increasingly apparent over the past few years. Cells contain a number of antioxidant defenses to minimize fluctuations in ROS, but ROS generation often exceeds the cell's antioxidant capacity, resulting in a condition termed oxidative stress. Host survival depends upon the ability of cells and tissues to adapt to or resist the stress, and repair or remove damaged molecules or cells. Numerous stress response mechanisms have evolved for these purposes, and they are rapidly activated in response to oxidative insults. Some of the pathways are preferentially linked to enhanced survival, while others are more frequently associated with cell death. Still others have been implicated in both extremes depending on the particular circumstances. In this review, we discuss the various signaling pathways known to be activated in response to oxidative stress in mammalian cells, the mechanisms leading to their activation, and their roles in influencing cell survival. These pathways constitute important avenues for therapeutic interventions aimed at limiting oxidative damage or attenuating its sequelae. Published 2002 Wiley‐Liss, Inc.
GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a role in S and G2/M cell cycle checkpoints induced by genotoxic stress
Authors: Vairapandi Mariappan , Balliet Arthur G. , Hoffman Barbara , Liebermann Dan A. 
Published: October 2002

AbstractGadd45a (Gadd45), Gadd45b (MyD118), and Gadd45g (CR6) constitute a family of evolutionarily conserved, small, acidic, nuclear proteins, which have been implicated in terminal differentiation, growth suppression, and apoptosis. How Gadd45 proteins function in negative growth control is not fully understood. Recent evidence has implicated Gadd45a in inhibition of cdc2/cyclinB1 kinase and in G2/M cell cycle arrest. Yet, whether Gadd45b and/or Gadd45g function as inhibitors of cdc2/cyclinB1 kinase and/or play a role in G2/M cell cycle arrest has not been fully established. In this work, we show that Gadd45b and Gadd45g specifically interact with the Cdk1/CyclinB1 complex, but not with other Cdk/Cyclin complexes, in vitro and in vivo. Data also has been obtained that Gadd45b and Gadd45g, as well as GADD45a, interact with both Cdk1 and cyclinB1, resulting in inhibition of the kinase activity of the Cdk1/cyclinB1 complex. Inhibition of Cdk1/cyclinB1 kinase activity by Gadd45b and Gadd45a was found to involve disruption of the complex, whereas Gadd45g did not disrupt the complex. Moreover, using RKO lung carcinoma cell lines, which express antisense Gadd45 RNA, data has been obtained, which indicates that all three Gadd45 proteins are likely to cooperate in activation of S and G2/M checkpoints following exposure of cells to UV irradiation. © 2002 Wiley‐Liss, Inc.
Studies on glycogen autophagy: Effects of phorbol myristate acetate, ionophore A23187, or phentolamine
Authors: Kalamidas S.A. , Kotoulas O.B. , Hann A.C. 
Published: October 2002

AbstractThe effects of agents that could manipulate the lysosomal calcium such as phorbol myristate acetate, ionophore A23187, and phentolamine on the lysosomal glycogen degradation were studied by electron microscopy, morphometric analysis, and biochemical assays in newborn rat hepatocytes. Phorbol myristate acetate, which promotes the input of calcium to lysosomes, increased the total volume of autophagic vacuoles and the activity of lysosomal glycogen‐hydrolyzing acid alpha 1,4 glucosidase and decreased the fractional volume of undigested glycogen inside the autophagic vacuoles and also decreased the activity of acid mannose 6‐phosphatase. Ionophore A23187, which releases lysosomal calcium, produced opposite results in these enzyme activities. Phentolamine, an alpha‐adrenergic blocking agent which interferes with the generation of phosphoinositides and may activate the lysosomal calcium uptake pump, increased the total volume of autophagic vacuoles and the activity of lysosomal glycogen‐hydrolyzing acid glucosidase and decreased the fractional volume of undigested glycogen inside the autophagic vacuoles. The results of this study constitute evidence that changes in lysosomal calcium may influence certain aspects of autophagy, including the degradation of glycogen inside the autophagic vacuoles. They also support our previous postulate [Kalamidas and Kotoulas (2000a,b) Histol Histopathol 15:29–35, 1011–1018] that stimulation of autophagic mechanisms in newborn rat hepatocytes may be associated with acid mannose 6‐phosphatase activity‐deficient lysosomes. Microsc. Res. Tech. 57:507–511, 2002. © 2002 Wiley‐Liss, Inc.
Evolution of median fin modules in the axial skeleton of fishes
Authors: Mabee Paula M. , Crotwell Patricia L. , Bird Nathan C. , Burke Ann C. 
Published: October 2002

AbstractDetailed examples of how hierarchical assemblages of modules change over time are few. We found broadly conserved phylogenetic patterns in the directions of development within the median fins of fishes. From these, we identify four modules involved in their positioning and patterning. The evolutionary sequence of their hierarchical assembly and secondary dissociation is described. The changes in these modules during the evolution of fishes appear to be produced through dissociation, duplication and divergence, and co‐option. Although the relationship between identified median fin modules and underlying mechanisms is unclear, Hox addresses may be correlated. Comparing homologous gene expression and function in various fishes may test these predictions.The earliest actinopterygians likely had dorsal and anal fins that were symmetrically positioned via a positioning module. The common patterning (differentiation) of skeletal elements within the dorsal and anal fins may have been set into motion by linkage to this positioning module. Frequent evolutionary changes in dorsal and anal fin position indicate a high level of dissociability of the positioning module from the patterning module. In contrast, the patterning of the dorsal and anal fins remains linked: In nearly all fishes, the endo‐ and exoskeletal elements of the two fins co‐differentiate. In all fishes, the exoskeletal fin rays differentiate in the same directions as the endoskeletal supports, indicating complete developmental integration. In acanthopterygians, a new first dorsal fin module evolved via duplication and divergence. The median fins provide an example of how basic modularity is maintained over 400 million years of evolution. J. Exp. Zool. (Mol. Dev. Evol.) 294:77–90, 2002. © 2002 Wiley‐Liss, Inc.
The tet‐off system is more effective than the tet‐on system for regulating transgene expression in a single adenovirus vector
Authors: Mizuguchi Hiroyuki , Hayakawa Takao 
Published: October 2002

AbstractBackgroundControl of transgene expression in mammalian cells is desirable for gene therapy and the study of gene function in basic research. This study evaluates the functionality of single adenovirus (Ad) vectors containing a tetracycline‐controllable expression system (tet‐off or tet‐on system).MethodsAn Ad‐mediated binary transgene expression system was generated containing a tet‐off or a tet‐on system, which introduced the gene of interest with a tetracycline‐regulatable promoter and the tetracycline‐responsive transcriptional activator gene into the E1 and E3 deletion regions, respectively. The functionality of the Ad‐mediated tet‐off and tet‐on systems was compared under various conditions in vitro and in vivo.ResultsThe Ad vector containing the tet‐off system provided negative control of gene expression ranging from 20‐ to 500‐fold, depending on the cell type and condition. In contrast, the Ad vector containing the tet‐on system increased gene expression by only 2‐ to 28‐fold and required about two‐log orders higher concentration of an inducer (doxycycline) to switch on the gene expression, compared with the Ad vector containing the tet‐off system.ConclusionAd vectors containing the tet‐off system are a better choice for regulated gene expression than Ad vectors containing the tet‐on system. Single Ad vectors containing the tetracycline‐controllable expression system will greatly facilitate in vitro and in vivo analyses of gene function and may be useful for gene therapy. Copyright © 2002 John Wiley & Sons, Ltd.