bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction of human skin fibroblasts with moderate wettable polyacrylonitrile–copolymer membranes
Authors: Groth Thomas , Seifert Barbara , Malsch Günter , Albrecht Wolfgang , Paul Dieter , Kostadinova Anelia , Krasteva Natalia , Altankov George 
Published: August 2002

AbstractThe development of a bioartificial skin is a step toward the treatment of patients with deep burns or nonhealing skin ulcers. One possible approach is based on growing dermal cells on membranes to obtain appropriate living cellular stroma (sheets) to cover the wound. New membrane‐forming copolymers were synthesized, based on acrylonitrile (AN) copolymerization with hydrophilic N‐vinylpyrrolidone (NVP) monomer, in different percentage ratios, such as 5, 20, and 30% w/w, and with two other relatively high polar comonomers—namely, sodium 2‐methyl‐2‐propene‐1‐sulfonic acid (NaMAS) and aminoethylmethacrylate (AeMA). All these copolymers were characterized for their bulk composition and number average molecular weight, and used to prepare ultrafiltration membranes. Water contact angles and water uptake were estimated to characterize the wettability and scanning force microscopy to visualize the morphology of the resulting polymer surface. Cytotoxicity was estimated according to the international standard regulations, and the materials were found to be nontoxic. The interaction of the membranes with human skin fibroblasts was investigated considering that these cells are among the first to colonize membranes upon implantation or with prolonged external contact. The overall cell morphology, formation of focal adhesion contacts, and cell proliferation were estimated to characterize the cell material interactions. It was found that the pure polyacrylonitrile homopolymer (PAN) membrane provides excellent conditions for seeding with fibroblasts, comparable only to a copolymer containing AeMA. In contrast, the presence of NaMAS with acidic ionic groups decreased both the attachment and proliferation of fibroblasts. Low content of NVP in the copolymer, up to about 5%, still enabled good attachment and spreading of cells, as well as subsequent proliferation of fibroblasts, but higher ratios of 20 and 30% resulted in a significant decrease of these cellular activities. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 290–300, 2002
Gene expression analysis of osteoblastic cells contacted by orthopedic implant particles
Authors: Pioletti Dominique P. , Leoni Lorenzo , Genini Davide , Takei Hiroshi , Du Pinyi , Corbeil Jacques 
Published: August 2002

AbstractParticles generated from orthopedic implants through years of wear play an essential role in the aseptic loosening of a prosthesis. We have investigated the biocompatibility of these orthopedic particles on different osteoblast‐like cells representative of different stages of osteoblast maturation. We found the particles induced a caspase‐dependent apoptosis of osteoblasts, with less mature osteoblasts being the most susceptible. An analysis of gene expression was performed on the less mature osteoblasts, which were in contact with the particles. We found that the particles had a profound impact on genes that code for inflammatory cytokines and genes involved in controlling the nuclear architecture. Results from this study suggest that the peri‐implant osteolysis after a total joint replacement can be due in part to a decrease of bone formation and not solely to an overstimulation of bone resorption as is generally proposed. Development of new drugs that promote normal bone formation and osteoblast survival would possibly control peri‐implant osteolysis, resulting in a better prognosis for patients with orthopedic implants. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 408–420, 2002
Transforming growth factor‐β 1, 2, and 3 can inhibit epithelial tissue outgrowth on smooth and microgrooved substrates
Authors: Walboomers X. F. , Dalton B. A. , Evans M. D. , Steele J. G. , Jansen J. A. 
Published: August 2002

AbstractIn this study, we describe the influence of parallel surface microgrooves, and of TGF‐β, on the outgrowth of corneal epithelial tissue. Microgrooves (depth 1 μm, width 1–10 μm) were made in polystyrene culturing surfaces. These surfaces were left untreated, or loaded with TGF‐β 1, 2, or 3 (6.0 ng/cm2). Subsequently, epithelial explants from bovine corneas were placed on the experimental surfaces. After 9 days of culturing, tissue outgrowth was evaluated. Furthermore, the tissue cultures were analyzed histologically. It was shown that epithelial tissue grew from the explants over all experimental surfaces. On microgrooved surfaces outgrowth proceeded in the direction of the grooves, rather than perpendicular to the grooves. The addition of each type of TGF‐β resulted in a reduction of outgrowth. However, outgrowth remained directed by the grooves. Further, the explants had shrunk after TGF treatment. Histology showed that this shrinkage was not related to α‐smooth muscle actin expression in the explants. We conclude that microgrooves can direct, and TGF‐βs can inhibit the outgrowth of epithelial tissue. This finding could be useful in biomaterial applications where the growth of epithelial tissue needs to be discouraged. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 445–451, 2002; DOI 10.1002/jbm.1290
Crystal structure‐based studies of cytosolic sulfotransferase
Authors: Yoshinari Kouichi , Petrotchenko Evgeniy V. , Pedersen Lars C. , Negishi Masahiko 
Published: August 2002

AbstractSulfation is a widely observed biological reaction conserved from bacterium to human that plays a key role in various biological processes such as growth, development, and defense against adversities. Deficiencies due to the lack of the ubiquitous sulfate donor 3′‐phosphoadenosine‐5′‐phosphosulfate (PAPS) are lethal in humans. A large group of enzymes called sulfotransferases catalyze the transfer reaction of sulfuryl group of PAPS to the acceptor group of numerous biochemical and xenochemical substrates. Four X‐ray crystal structures of sulfotransferases have now been determined: cytosolic estrogen, hydroxysteroid, aryl sulfotransferases, and a sulfotransferase domain of the Golgi‐membrane heparan sulfate N‐deacetylase/N‐sulfotransferase 1. These have revealed the conserved core structure of the PAPS binding site, a common reaction mechanism, and some information concerning the substrate specificity. These crystal structures introduce a new era of the study of the sulfotransferases. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:67–75, 2001
Sequencing, expression, and characterization of cDNA expressed flavin‐containing monooxygenase 2 from mouse
Authors: Karoly Edward D. , Rose Randy L. 
Published: August 2002

AbstractThe cDNA clone of mouse flavin‐containing monooxygenase 2 (FMO2) was obtained as an expressed sequence tag (EST) isolated from a female mouse kidney cDNA library from the I.M.A.G.E. consortium (I.M.A.G.E. CloneID 1432164). Complete sequencing of the EST derived a nucleotide sequence for mouse FMO2, which contains 112 bases of 5′ flanking region, 1607 bases of coding region, and 309 bases of 3′ flanking region. This FMO2 sequence encodes a protein of 535 amino acids including two putative pyrophosphate binding sequences (GxGxxG/A) beginning at positions 9 and 191. Additionally, this mouse FMO protein sequence shows 87 and 86% homology to rabbit and human FMO2 respectively. The mouse FMO2 sequence was subcloned into the expression vector pJL‐2, a derivative of pKK233‐2 and used to transform XL1‐Blue Escherichia coli. FMO activity in particulate fractions isolated from isopropyl‐β‐D‐thiogalactopyanoside (IPTG) induced cells was heat stable (45°C for 5 min) and demonstrated optimal activity at a relatively high pH of 10.5. The expressed FMO2 enzyme showed catalytic activity towards the FMO substrate methimazole and further analysis of E. coli fractions utilizing NADPH oxidation demonstrated that the mouse FMO2 enzyme also exhibits catalytic activity towards thiourea, trimethylamine, and the insecticide phorate. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:300–308, 2001
In vitro human phase I metabolism of xenobiotics I: Pesticides and related chemicals used in agriculture and public health, September 2001
Authors: Hodgson Ernest 
Published: August 2002

AbstractHuman phase I enzymes and their isoforms that metabolize pesticides are listed in a database that will be updated periodically. This initial version includes enzymes and isoforms that metabolize organophosphorus insecticides, chloroacetamide herbicides and triazine herbicides. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:296–299, 2001
Acute sodium arsenite treatment induces Cyp2a5 but not Cyp1a1 in the C57Bl/6 mouse in a tissue (kidney) selective manner
Authors: Seubert John M. , Webb Christopher D. , Bend John R. 
Published: August 2002

AbstractModulation of hepatic and extrahepatic detoxication enzymes Cyp1a1, Cyp2a5, glutathione S‐transferse Ya (GSTYa) and NAD(P)H:quinone oxidoreductase (QOR) dependent catalytic activity and mRNA levels were investigated at 1, 2, or 4 days in liver, lung, or kidney of male, adult CD57 Bl/6 mice treated sc with a single dose (85 μmol/kg) of sodium arsenite (As3+). Maximum decreases of total hepatic cytochrome P450 (CYP) monooxygenase content and catalytic activities, occurring at 24 h, corresponded with maximum increases of heme oxygenase (HO‐1) in all tissues, as well as maximum plasma total bilirubin. Extrahepatic increases in CYP were observed only in non‐AHR dependent isozymes in the kidney, where both Cyp2a5 mRNA and catalytic activity increased maximally 24 h after treatment. In contrast, no significant changes in Cyp2b1/2‐dependent PROD or mRNA activity and decreases in Cyp1a1‐dependent‐EROD activity were noted 1, 2, or 4 days after treatment. Increases in QOR catalytic activities were observed in all tissues examined with increased mRNA in kidney. On the other hand, GSTYa catalytic activity and mRNA increases were only detected in kidney. This study demonstrates the differential modulation of CYP, QOR, and GST‐Ya, important drug metabolizing enzymes after acute As3+ administration. The induction of Cyp2a5, QOR, and GSTYa catalytic activity and gene expression occurred primarily in kidney during or shortly after conditions of oxidant stress. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:96–106, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/jbt.10023
Hypocalcemic toxicity and atypical reactions in therapeutic plasma exchange
Authors: Weinstein Robert 
Published: August 2002

AbstractHypocalcemic toxicity accounts for the most common adverse effects of therapeutic plasma exchange. The symptoms can be related to a fall in plasma ionized calcium. Citrate‐based anticoagulants, notably sodium citrate and ACD formula A, have been indicated as the major cause of hypocalcemic toxicity, but colloid replacement fluids containing human serum albumin are also at fault. Recognition of the signs and symptoms of hypocalcemic toxicity is important because several clinical measures are available to deal with them and to ensure patient comfort. A typical reactions, characterized by flushing and hypotension during plasma exchange, have been attributed to the effects of angiotensin converting enzyme inhibitors. Both exchange and adsorption apheresis procedures can result in atypical reactions in patients who have been taking this class of drugs within 48 to 72 hours of an apheresis procedure. These reactions are less common than hypocalcemic toxicity, but can be prevented by paying attention to detail. J. Clin. Apheresis 16:210–211, 2001. © 2001 Wiley‐Liss, Inc.
Audit Committees: How Good Are They?
Authors: DeZoort F.Todd , Hermanson Dana R. , Houston Richard W. 
Published: August 2002

AbstractAudit committees must bear some of the blame for recent corporate scandals. Perhaps they were asleep at the
switch. But how much financial expertise do audit committee members really have? And how often do they
discuss materiality issues with auditors? A national survey of 300 audit committee members provides some
answers—and not all of them are comforting. © 2002 Wiley Periodicals, Inc.
Basic fibroblast growth factor decreases elastin gene transcription in aortic smooth muscle cells
Authors: Carreras Isabel , Rich Celeste B. , Panchenko Mikhail P. , Foster Judith Ann 
Published: August 2002

AbstractThe extracellular matrix (ECM) protein elastin plays an essential role in the cardiovascular system by imparting elasticity to blood vessel wall. In this study, we examined the effect of basic fibroblast growth factor (bFGF) on the expression of elastin in aortic smooth muscle cells (SMC) to gain insight into events associated with cardiovascular diseases. The results show that bFGF treatment of SMC causes a significant decrease in elastin mRNA and secreted tropoelastin levels. Nuclear run‐on analyses demonstrate that the downregulation is due to a decrease in the level of elastin gene transcription. Transient transfections of SMC with wild‐type and mutated elastin gene promoter/chloramphenicol acetyl transferase (CAT) constructs show that a previously identified activator protein‐1‐cAMP response element (AP1/CRE) (−564 to −558‐bp) within the elastin promoter mediates the bFGF‐dependent downregulation of elastin gene transcription in SMC. Addition of bFGF to SMC activates the extracellular signal‐regulated kinases 1/2 (ERK1/2) resulting in their translocation into the nucleus and subsequent induction of Fra‐1. The addition of PD‐98059, an inhibitor of ERK1/2 kinase, abrogates the bFGF‐dependent decrease of elastin mRNA in SMC. The described inhibitory effect of bFGF on elastin gene expression in SMC may significantly contribute to the inefficient repair of elastin in early stages of vascular wall injury. J. Cell. Biochem. 85: 592–600, 2002. © 2002 Wiley‐Liss, Inc.
Estrogen and Myc negatively regulate expression of the EphA2 tyrosine kinase
Authors: Zelinski Daniel P. , Zantek Nicole Dodge , Walker‐Daniels Jennifer , Peters Mette A. , Taparowsky Elizabeth J. , Kinch Michael S. 
Published: August 2002

AbstractEstrogen receptor and c‐Myc are frequently overexpressed during breast cancer progression but are downregulated in many aggressive forms of the disease. High levels of the EphA2 tyrosine kinase are consistently found in the most aggressive breast cancer cells, and EphA2 overexpression can increase metastatic potential. We demonstrate, herein, that estrogen and Myc negatively regulate EphA2 expression in mammary epithelial cells. These data reveal EphA2 as a downstream target of estrogen and Myc and suggest a mechanism by which estrogen and Myc may regulate breast cancer. J. Cell. Biochem. 85: 714–720, 2002. © 2002 Wiley‐Liss, Inc.
Breakpoints of t(4;11) translocations in the human MLL and AF4 genes in ALL patients are preferentially clustered outside of high‐affinity matrix attachment regions
Authors: Hensel Jan Patrick , Gillert Esther , Fey Georg H. , Marschalek Rolf 
Published: August 2002

AbstractChromosomal translocations t(4;11) are based on illegitimate recombinations between the human MLL and AF4 genes, and are associated with high‐risk acute leukemias of infants and young children. Here, the question was asked, whether a correlation exists between the location of translocation breakpoints within both genes and the location of S/MARs. In “halo mapping experiments” (to define SARs), about 20 kb of MLL DNA was found to be attached to the nuclear matrix. Similar experiments performed for the translocation partner gene AF4 revealed that SARs are spanning nearly the complete breakpoint cluster region of the AF4 gene. By using short DNA fragments in “scaffold reassociation experiments” (to define MARs), similar results were obtained for both genes. However, Distamycin A competition experiments in combination with “scaffold reassociation experiments” revealed specific differences in the affinity of each tested DNA fragment to bind the isolated nuclear matrix proteins. When the latter data were compared with the known location of chromosomal breakpoints for both genes, an unexpected correlation was observed. DNA areas with strong MAR affinity contained fewer translocation breakpoints, while areas with weak or absent MAR affinity showed a higher density of chromosomal breakpoints. J. Cell. Biochem. 82: 299–309, 2001. © 2001 Wiley‐Liss, Inc.
An ab initio theoretical study of electronic structure and properties of 2′‐deoxyguanosine in gas phase and aqueous media
Authors: Mishra S. K. , Mishra P. C. 
Published: August 2002

AbstractMolecular geometries of two structural forms of 2′‐deoxyguanosine (keto‐N9R and keto‐N7R, R = the sugar moiety) considering both the C2′‐endo and C3′‐endo conformations of the sugar ring and those of the complexes of these species with two water molecules each were optimized employing the ab initio RHF procedure. A mixed basis set consisting of the 6‐311+G* basis set for the nitrogen atom of the amino group and the 4‐31G basis set for all the other atoms was used. The RHF calculations were followed by correlation correction of the total energy at the MP2 level. Both the structural forms of 2′‐deoxyguanosine were solvated using the polarized continuum model (PCM) of the self‐consistent reaction field (SCRF) theory and the corresponding RHF optimized geometries at the RHF and MP2 levels. Geometry optimization was also performed in aqueous media using the Onsager model at the RHF level using the above‐mentioned mixed basis set, and subsequently, using the reoptimized geometries, single‐point MP2 calculations were performed. It is found that both the keto‐N9R and keto‐N7R forms of 2′‐deoxyguanosine as well as their complexes with two water molecules each would occur, particularly at the water–air interface. Though the normal Watson–Crick‐type base pairing would not be possible with the keto‐N7R form of 2′‐deoxyguanosine(G*), two other (G*‐C and G*‐T) base pairing schemes may occur with this form of the nucleoside, which may cause mutation. The present calculated geometry of the keto‐N9R form of the anti‐conformation of 2′‐deoxyguanosine including the dihedral angle χCN agree satisfactorily with the available crystallographic results. The present results also agree satisfactorily with those obtained by other authors earlier for the keto‐N9R form of 2′‐deoxyguanosine using B3LYP and MP2 methods employing the 6‐31G* basis set. Using transition state calculations, it is shown that tautomerism of guanine and other similar molecules where the tautomers would coexist would be facilitated by the occurrence of the H+ and OH− fragments of water molecules. Further, this coexistence of the two tautomers appears to make the C8 carbon atom located between the N7 and N9 nitrogen atoms susceptible to attack by the OH− group. Thus, an explanation is obtained for the efficient formation of the reaction product 8‐hydroxy‐2′‐deoxyguanosine, which serves as a biomarker for oxidative damage to DNA in biological systems. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 530–540, 2002; DOI 10.1002/jcc.10046
Efficiency of the multicanonical simulation method as applied to peptides of increasing size: The heptapeptide deltorphin
Authors: Yaşar Fatih , Arkin Handan , Çelik Tarik , Berg Bernd A. , Meirovitch Hagai 
Published: August 2002

AbstractThe advantage of the multicanonical (MUCA) simulation method of Berg and coworkers over the conventional Metropolis method is in its ability to move a system effectively across energy barriers thereby providing results for a wide range of temperatures. However, a MUCA simulation is based on weights (related to the density of states) that should be determined prior to a production run and their calculation is not straightforward. To overcome this difficulty a procedure has been developed by Berg that calculates the MUCA weights automatically. In a previous article (Yaşar et al. J Comput Chem 2000, 14, 1251–1261) we extended this procedure to continuous systems and applied it successfully to the small pentapeptide Leu‐enkephalin. To investigate the performance of the automated MUCA procedure for larger peptides, we apply it here to deltorphin, a linear heptapeptide with bulky side chains (H‐Tyr1‐D‐Met2‐Phe3‐His4‐Leu5‐Met6‐Asp7‐NH2). As for Leu‐enkephalin, deltorphin is modeled in vacuum by the potential energy function ECEPP. MUCA is found to perform well. A weak second peak is seen for the specific heat, which is given a special attention. By minimizing the energy of structures along the trajectory it is found that MUCA provides a good conformational coverage of the low energy region of the molecule. These latter results are compared with conformational coverage obtained by the Monte Carlo minimization method of Li and Scheraga. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1127–1134, 2002
The performance of different density functional methods in the calculation of molecular structures and vibrational spectra of platinum(II) antitumor drugs: cisplatin and carboplatin
Authors: Wysokiński Rafał , Michalska Danuta 
Published: August 2002

AbstractA comparison of eight density functional models for predicting the molecular structures, vibrational frequencies, infrared intensities, and Raman scattering activities of platinum(II) antitumor drugs, cisplatin and carboplatin, is reported. Methods examined include the pure density functional protocols (G96LYP, G96PW91, modified mPWPW and original PW91PW91), one‐parameter hybrid approaches (mPW1PW and mPW1LYP), and three‐parameter hybrid models (B3LYP and B3PW91), as well as the HF and MP2 levels of theory. Different effective core potentials (ECPs) and several basis sets are considered. The theoretical results are discussed and compared with the experimental data. It is remarkable that the mPW1PW protocol introduced by Adamo and Barone [J Chem Phys 1998, 108, 664], is clearly superior to all the remaining density functional methods (including B3LYP). The geometry and vibrational frequencies of cisplatin and carboplatin calculated with the mPW1PW method, and the ECP of Hay and Wadt (LanL2DZ basis set) are in better agreement with experiment than those obtained with the MP2 method. The use of more elaborated ECP and the enlargements of basis sets do not significantly improve the results. A clear‐cut assignments of the platinum‐ligand vibrations in cisplatin and carboplatin are presented. It is concluded that mPW1PW is the new reliable method, which can be used in predicting molecular structures and vibrational spectra of large coordination compounds containing platinum(II). © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 901–912, 2001
Collective motions of myosin head derived from backbone molecular dynamics and combination with X‐ray solution scattering data
Authors: Higo Junichi , Sugimoto Yasunobu , Wakabayashi Katsuzo , Nakamura Haruki 
Published: August 2002

AbstractCollective modes of myosin head, S1, were derived from molecular dynamics trajectories of a simplified protein model, backbone model. Because the model requires only the positions of Cα‐atoms, large proteins are tractable, even when the amino acid sequence and the side‐chain orientations are unknown. The S1 is a large molecule and only the Cα‐atomic positions have been experimentally determined. In the simulation, large flipping motions of the extended α‐helical C‐terminal tail of S1 were found only in the largest and second largest amplitude collective modes, which were approximately perpendicular to each other. A few collective modes other than the first and second largest ones largely deformed the actin binding site of S1. The pair‐distance distribution, obtained from the X‐ray solution scattering, suggests a large conformational change of S1, isolated in solution without binding to actin filament, during the ATP hydrolysis. The modeling of the large conformational change was done with using the collective modes, and showed that the second mode mainly contributed to the large conformational change. The modeling procedure, introduced here, can be easily generalized for various experimental data, and applicable to the collective modes obtained from an all‐atom simulation. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1983–1994, 2001