bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parental representations and subclinical changes in postpartum mood
Authors: Mayes Linda C. , Leckman James F. 
Published: April 2007

AbstractParents commonly experience a depressed mood in the immediate postpartum period, and a smaller proportion experience clinical postpartum depression. Among other factors, mental representations of early parenting experience appear to contribute to the development of major depressive disorder. The present study examines the role of mental representations of early parenting in subclinical fluctuations of parental mood in the peripartum period. Forty‐one middle‐class mothers and thirty‐six fathers were interviewed on three occasions from late in their pregnancy until three months postpartum. Ratings of social support and past history of depression were obtained along with ratings of parents' perceptions of their early parenting experiences. Parents' perception of their own maternal care was significantly predictive of peripartum fluctuations in mood. Parents who perceived their own mothers as less caring showed more dysphoria at 8 months gestation, and at 2 weeks and 3 months postpartum. Perceptions of maternal protectiveness or fathers' caring and protectiveness were not related to prenatal or postpartum mood fluctuations. Both mothers and fathers who perceived their mothers as affectionless and/or controlling were more likely to experience fluctuations in mood in the peripartum period. A past history of one or more episodes of major depression and ratings of perceived social support were also associated with more peripartum mood fluctuation. These findings suggest that early parenting experiences set the threshold for how vulnerable parents are in the peripartum period to the depressive costs of engaging with a new infant.
Dose effects of cross‐linking polyethylene for total knee arthroplasty on wear performance and mechanical properties
Authors: Asano Taiyo , Akagi Masao , Clarke Ian C. , Masuda Shingo , Ishii Tsunehiro , Nakamura Takashi 
Published: April 2007

AbstractWear performance and mechanical properties of cross‐linking polyethylene (XLPE) tibial inserts were investigated using a knee simulator, scanning electron microscopy (SEM), and a small punch test (SPT). Ultrahigh molecular weight PE made from GUR1050 resin was irradiated at doses ranging from 0 to 200 kGy and then machined into tibial inserts followed by annealing. The knee simulator was run for up to four million cycles. As the radiation dose increased from 0 to 100 kGy, the wear rate decreased dramatically, yielding 95% wear reduction at 100 kGy. The microwear features observed by SEM supported the dose‐dependent wear reduction. The SPT for XLPE after the simulation test showed that, as the radiation dose increased from 0 to 200 kGy, the ultimate displacement decreased dose‐dependently, while the ultimate load increased from 0 to 75 kGy and decreased from 75 to 200 kGy. The resulting toughness of the PE increased to its maximum at a dose of 50 kGy and then decreased with higher doses up to 200 kGy. PE cross‐linked with radiation doses from 25 to 75 kGy had greater toughness than virgin, nonirradiated PE. However, PE irradiated with 100 kGy or more had lower toughness than virgin PE. These data suggest that a certain amount of irradiation enhances both wear performance and toughness of PE tibial inserts. Although a certain amount of cross‐linking would be effective for clinical application of PE tibial inserts, an optimal radiation dose should be much smaller than that used in current XLPE in total hip arthroplasty. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Importance of the hybrid layer on the bond strength of restorations subjected to cyclic loading
Authors: Yamazaki Paula C. V. , Bedran‐Russo Ana Karina B. , Pereira Patricia N. R. 
Published: April 2007

AbstractThe present study evaluated the long‐term microtensile bond strength of collagen‐depleted dentin followed by cyclic loading. Bovine flat, midcoronal dentin received one of the following surface treatments: acid‐etch or acid‐etched + 5% NaOCl for 2 min. The teeth were restored with Single Bond, Scotchbond Multi‐purpose, One‐Step Plus, or All‐Bond 2 adhesive systems. Half of the specimens were randomly assigned to receive 200,000 cycles (50 N force). Teeth were sectioned into 1 × 1 mm thick slices and stored for 24 h, 1 month, 3 months, or 6 months. Specimens were subjected to tensile testing after elapsed storage time. Samples were analyzed by three‐way ANOVA and Fisher's PLSD (p < 0.05). The results showed that the deproteinized groups without cyclic loading presented lower bond strength when compared with the control group, but the difference was only statistically significant for Single Bond and All‐Bond 2 (p < 0.05). All adhesives presented a decrease in bond strength over time, regardless of the dentin treatment. When cyclic loaded, the decrease in bond strength for the deproteinized group was even greater when compared with the control group (p < 0.05). The results suggest that the hybrid layer is important as a stress‐buffering layer when loading is applied, and thus the presence of collagen is essential. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Heat denaturation of fibrinogen to develop a biomedical matrix
Authors: Marx Gerard , Mou Xiaode , Hotovely‐Salomon Anna , Levdansky Lilia , Gaberman Elena , Belenky Dimitry , Gorodetsky Raphael 
Published: April 2007

AbstractNative and heat denatured fibrinogen are the basis for various matrices used to establish hemostasis as well as for constructing biomedical devices. For example, fibrin microbeads (FMB) prepared by a heated (∼70°C) oil emulsion process were reported to be attractive to mesenchymal‐type cells, such as fibroblasts, endothelial and smooth muscle cells, and useful for isolating mesenchymal stem cells from bone marrow. Here, we examined the solution properties of fibrinogen subjected to heat (47–60°C). Fibrinogen exhibited maximal stability of pHmax stab = 6.8. At physiologically relevant concentrations, Ca(II) stabilized and Zn(II) destabilized fibrinogen against heat denaturation. Scanning electron micrographs (SEM) of precipitated, heat denatured, fibrinogen showed globular structures (∼400 nm diameter), composed of aggregates of >3000 fibrinogen monomers. Monoclonal antibodies (MAb) to various regions of fibrinogen, as well as two polyclonal antibody (Ab) to haptotactic peptides (Haptides) equivalent to or near the C‐termini of β and γ‐chains (β463–483 and γ372–391/411), were used to monitor epitopic changes of fibrinogen bound to and heated on plastic ELISA plates. The pattern of altered Ab binding indicated that fibrinogen heat denaturation on plastic exposed the C‐terminal epitope γ397‐411 as well as Haptide epitopes (β463–483 and γ372–391). Immuno‐staining of FMB prepared by a heated (below 75°C) oil emulsion process, also presented many exposed Haptide epitopes, which probably helped to attract cells. Our results indicated that moderately heat‐denatured fibrinogen, in the form of FMB, could be used for cell culturing and biomedical applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Effect of YSZ thin film coating thickness on the strength of a ceramic substrate
Authors: Teixeira Erica C. , Piascik Jeffrey R. , Stoner Brian R. , Thompson Jeffrey Y. 
Published: April 2007

AbstractAlthough ceramics are used for many different biomedical applications they are brittle materials that can be compromised by surface defects when under stress. The objective of this study was to evaluate the effect of surface modification with an yttria‐stabilized zirconia (YSZ) thin film coating on the strength of a machinable dental ceramic. Fifty bars (2 mm ×××× 2 mm ×××× 15 mm) were cut from ProCAD (Ivoclar‐Vivadent) blocks. Specimens were wet‐polished through 1200‐grit SiC abrasive. One surface of each bar was sandblasted with 50 μm Al2O3 abrasive (0.34 MPa). Specimens were further modified through the deposition of a sputtered YSZ thin film on the sandblasted surface. Different thin film thicknesses were evaluated: 1, 3, 5, and 7 μm. Depositions were performed using a radio frequency magnetron sputter system (working pressure of 15 mT, 150°C, 30:1 Ar/O2 gas ratio). Flexural strength measurements were carried out by three‐point bending (span = 10 mm) in a servo‐electric material testing system in DI water (37°C). The results showed that the strength of porcelain significantly increased with the deposition of a 3‐μm YSZ thick coating. A nonlinear relationship was observed between film thickness and strength. Strengthening of porcelain is shown through the application of a sputtered YSZ thin film. It is presumed that the strengthening mechanism is due to modification of surface flaws and/or surface residual stress by the applied thin film. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Transcriptional regulation of aquaporin 3 by insulin
Authors: Higuchi Shota , Kubota Masafumi , Iguchi Kazuhiro , Usui Shigeyuki , Kiho Tadashi , Hirano Kazuyuki 
Published: April 2007

AbstractIn the current study, we identified a regulatory factor for the transcription of aquaporin 3 (AQP3) whose expression is repressed by insulin. We constructed a luciferase reporter vector containing bp −1382 to −12 of the 5′‐flanking region of the AQP3 gene for a reporter gene assay and observed that luciferase activity in transfectants with the plasmid decreased on treatment with insulin. Serial deletion constructs revealed two regions responsible for the insulin‐mediated repression, one between bps −1382 and −780, and the other between bps −404 and −82. mRNA expression of forkhead box a2 (Foxa2), the binding site of which was located between bps −1382 and −780, was found to decrease on treatment with insulin. A mutant reporter plasmid with an altered Foxa2‐binding site and siRNA for the Foxa2 sequence counteracted the insulin‐mediated repression of AQP3 transcription. These results suggest that Foxa2 is one of the transcriptional regulators for AQP3 gene expression regulated by insulin. J. Cell. Biochem. 102: 1051–1058, 2007. © 2007 Wiley‐Liss, Inc.
HSPA1A is an important regulator of the stability and function of ZNF198 and its oncogenic derivative, ZNF198–FGFR1
Authors: Kasyapa Chitta S. , Kunapuli Padmaja , Cowell John K. 
Published: April 2007

AbstractMass spectroscopy analysis demonstrated that the HSPA1A protein is found in complex with the ZNF198 protein which is involved in a chromosome rearrangement with the FGFR1 gene in an atypical myeloproliferative disease. HSPA1A is a member of the HSP70 family of genes which has been shown to be inducible in a variety of circumstances. Exogenous expression of the ZNF198–FGFR1 fusion kinase gene as well as ZNF198 in a model cell system results in a large (>650‐fold) increase in HSP70 mRNA levels. Using KNK437, a specific inhibitor of HSP70 transcription, we have demonstrated that an important function of HSPA1A is to stabilize the ZNF198 and ZNF198–FGFR1 proteins. In the absence of HSPA1A, specific functions of ZNF198–FGFR1 such as STAT3 phosphorylation is also lost. Treatment of cells with KNK437 in the presence of MG132, an inhibitor of proteasomal degradation of proteins, suggested that only the ZNF198–FGFR1 protein is subject to the proteasomal degradation pathway, while ZNF198 is not. These observations suggest an important role for HSPA1A in ZNF198 and ZNF198–FGFR1 mediated cellular function. J. Cell. Biochem. 102: 1308–1317, 2007. © 2007 Wiley‐Liss, Inc.
Structure–Function analysis of secreted frizzled‐related protein‐1 for its Wnt antagonist function
Authors: Bhat Ramesh A. , Stauffer Barbara , Komm Barry S. , Bodine Peter V.N. 
Published: April 2007

AbstractSecreted frizzled‐related proteins (sFRPs) are glycoproteins that are recognized as Wnt antagonists. To identify the functional domains that are involved in Wnt antagonist function, several sFRP‐1 mutants and sFRP‐1/sFRP‐2 chimeras were generated. These mutants were characterized in an optimized T‐cell factor (TCF)‐luciferase based assay in U2OS human osteosarcoma cells. Deletions of the sFRP‐1 cysteine rich domain (CRD) lead to the complete loss of Wnt antagonist function. A region between amino acids 73–86 within the second loop of the CRD of sFRP‐1 was necessary for the optimal Wnt inhibitory function. Within this region, a conserved tyrosine residue played a critical role, and its change to neutral or polar amino acids lead to decreased Wnt inhibitory activity. The sFRP‐1/sFRP‐2 chimeras with the netrin domain of sFRP‐1 replaced by corresponding sFRP‐2 sequences showed 40–70% loss of Wnt antagonist function. The sFRP‐1/sFRP‐2 chimera with the replacement of C‐terminal 19 amino acids of sFRP‐1 with 11 amino acids of sFRP‐2 resulted in 70% loss of activity indicating that carboxyl‐terminal region of sFRP‐1 is important for its Wnt inhibitory activity. The structure–function analysis studies of sFRP‐1 clearly demonstrate the interaction of several functional domains for its optimal Wnt antagonist function. J. Cell. Biochem. 102: 1519–1528, 2007. © 2007 Wiley‐Liss, Inc.
Molecular cloning and characterization of the Xenopus hypoxia‐inducible factor 1α (xHIF1α)
Authors: de Beaucourt Arnaud , Coumailleau Pascal 
Published: April 2007

AbstractWe report the molecular cloning and the characterization of the Xenopus homolog of mammalian hypoxia‐inducible factor 1α (HIF1α), a member of the bHLH/PAS transcription factor family. Searches in Xenopus genome sequences and phylogenetic analysis reveal the existence of HIF1α and HIF2α paralogs in the Xenopus laevis species. Sequence data analyses indicate that the organization of protein domains in Xenopus HIF1α (xHIF1α) is strongly conserved. We also show that xHIF1α heterodimerizes with the Xenopus Arnt1 protein (xArnt1) with the proteic complex being mediated by the HLH and PAS domains. Subcellular analysis in a Xenopus XTC cell line using chimeric GFP constructs show that over‐expression of xHIF1α and xArnt1 allows us to detect the xHIF1α/xArnt1 complex in the nucleus, but only in the presence of both partners. Further analyses in XTC cell line show that over‐producing xHIF1α and xArnt1 mediates trans‐activation of the hypoxia response element (HRE) reporter. The trans‐activation level can be increased in hypoxia conditions. Interestingly such trans‐activation properties can be also observed when human Arnt1 is used together with the xHIF1α. J. Cell. Biochem. 102: 1542–1552, 2007. © 2007 Wiley‐Liss, Inc.
CNBP mediates neural crest cell expansion by controlling cell proliferation and cell survival during rostral head development
Authors: Weiner A.M.J. , Allende M.L. , Becker T.S. , Calcaterra Nora B. 
Published: April 2007

AbstractStriking conservation in various organisms suggests that cellular nucleic acid binding protein (CNBP) plays a fundamental biological role across different species. Recently, it was reported that CNBP is required for forebrain formation during chick and mouse embryogenesis. In this study, we have used the zebrafish model system to expand and contextualize the basic understanding of the molecular mechanisms of CNBP activity during vertebrate head development. We show that zebrafish cnbp is expressed in the anterior CNS in a similar fashion as has been observed in early chick and mouse embryos. Using antisense morpholino oligonucleotide knockdown assays, we show that CNBP depletion causes forebrain truncation while trunk development appears normal. A substantial reduction in cell proliferation and an increase in cell death were observed in the anterior regions of cnbp morphant embryos, mainly within the cnbp expression territory. In situ hybridization assays show that CNBP depletion does not affect CNS patterning while it does cause depletion of neural crest derivatives. Our data suggest an essential role for CNBP in mediating neural crest expansion by controlling proliferation and cell survival rather than via a cell fate switch during rostral head development. This possible role of CNBP may not only explain the craniofacial anomalies observed in zebrafish but also those reported for mice and chicken and, moreover, demonstrates that CNBP plays an essential and conserved role during vertebrate head development. J. Cell. Biochem. 102: 1553–1570, 2007. © 2007 Wiley‐Liss, Inc.
Osteoprotegrin and the bone homing and colonization potential of breast cancer cells
Authors: Kapoor Preeti , Suva Larry J. , Welch Danny R. , Donahue Henry J. 
Published: April 2007

AbstractBreast cancer cells preferentially metastasize to bone, leading to the formation of primarily osteolytic lesions. Osteoprotegerin (OPG) plays multifactorial roles in the development of osteolytic bone metastases. An increase in the ratio of receptor activator of nuclear factor κB ligand (RANKL) to OPG increases osteoclastogenesis within the bone microenvironment. OPG also acts as a survival factor for cancer cells by protecting them from tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) mediated apoptosis. This study compares OPG production in vitro in a number of breast cancer cell lines exhibiting both differences in metastatic capacity and in preferential metastasis to bone. Our studies demonstrated that OPG expression by MDA‐231, MDA‐MET, and MDA‐231/K cancer cells was directly correlated with bone specific homing and colonization potential but not with metastasis of cancer cells to other organs; both in IL‐1β stimulated and control cells. We also demonstrated expression of other bone‐related markers including type I collagen, osteocalcin, osteopontin, and Runx2 in these cells. However, the generally lower expression of these markers in the bone selective cell line MDA‐MET suggested that increased OPG expression in the bone specific variant was not merely a consequence of enhanced osteomimicry by these cells but that it has a significant role in the metastatic process. Co‐culture of breast cancer cells with osteoblastic cells (hFOB 1.19) led to an overall downregulation in OPG production, which was not affected by the bone homing and colonization potential of the cell lines, suggesting that OPG alone is not indicative of osteolytic bone activity by breast cancer cells. J. Cell. Biochem. 103: 30–41, 2008. © 2007 Wiley‐Liss, Inc.
Dead‐end elimination for multistate protein design
Authors: Yanover Chen , Fromer Menachem , Shifman Julia M. 
Published: April 2007

AbstractMultistate protein design is the task of predicting the amino acid sequence that is best suited to selectively and stably fold to one state out of a set of competing structures. Computationally, it entails solving a challenging optimization problem. Therefore, notwithstanding the increased interest in multistate design, the only implementations reported are based on either genetic algorithms or Monte Carlo methods. The dead‐end elimination (DEE) theorem cannot be readily transfered to multistate design problems despite its successful application to single‐state protein design. In this article we propose a variant of the standard DEE, called type‐dependent DEE. Our method reduces the size of the conformational space of the multistate design problem, while provably preserving the minimal energy conformational assignment for any choice of amino acid sequence. Type‐dependent DEE can therefore be used as a preprocessing step in any computational multistate design scheme. We demonstrate the applicability of type‐dependent DEE on a set of multistate design problems and discuss its strength and limitations. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Odd–even effects in the homologous series of alkyl‐cyanobiphenyl liquid crystals: A molecular dynamic study
Authors: Capar Mine Ilk , Cebe Emine 
Published: April 2007

AbstractFor the first five members of the homologous series of 4‐n‐alkyl‐4′‐cyanobiphenyls in the nematic and isotropic phases, molecular dynamics (MD) simulations were performed by using a united atom model. An odd–even effect was seen to be found in the molecular length, width, biaxiality, and inertia tensor anisotropy with the length of alkyl chain. The distributions of the molecular length, width, and inertia tensor anisotropy were presented. The orientational distributions of the last CC bonds in the alkyl chain were also evaluated for nematic and isotropic phases. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
An object‐oriented library for computational protein design
Authors: Chowdry Arnab B. , Reynolds Kimberly A. , Hanes Melinda S. , Voorhies Mark , Pokala Navin , Handel Tracy M. 
Published: April 2007

AbstractRecent advances in computational protein design have established it as a viable technique for the rational generation of stable protein sequences, novel protein folds, and even enzymatic activity. We present a new and object‐oriented library of code, written specifically for protein design applications in C++, called EGAD Library. The modular fashion in which this library is written allows developers to tailor various energy functions and minimizers for a specific purpose. It also allows for the generation of novel protein design applications with a minimal amount of code investment. It is our hope that this will permit labs that have not considered protein design to apply it to their own systems, thereby increasing its potential as a tool in biology. We also present various uses of EGAD Library: in the development of Interaction Viewer, a PyMOL plug‐in for viewing interactions between protein residues; in the repacking of protein cores; and in the prediction of protein–protein complex stabilities. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
An extended dead‐end elimination algorithm to determine gap‐free lists of low energy states
Authors: Kloppmann Edda , Ullmann G. Matthias , Becker Torsten 
Published: April 2007

AbstractProteins are flexible systems and commonly populate several functionally important states. To understand protein function, these states and their energies have to be identified. We introduce an algorithm that allows the determination of a gap‐free list of the low energy states. This algorithm is based on the dead‐end elimination (DEE) theorem and is termed X‐DEE (extended DEE). X‐DEE is applicable to discrete systems whose state energy can be formulated as pairwise interaction between sites and their intrinsic energies. In this article, the computational performance of X‐DEE is analyzed and discussed. X‐DEE is implemented to determine the lowest energy protonation states of proteins, a problem to which DEE has not been applied so far. We use X‐DEE to calculate a list of low energy protonation states for two bacteriorhodopsin structures that represent the first proton transfer step of the bacteriorhodopsin photocycle. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007