bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of exercise duration on the key pathways of ceramide metabolism in rat skeletal muscles
Authors: Błachnio‐Zabielska Agnieszka , Baranowski Marcin , Zabielski Piotr , Górski Jan 
Published: August 2008

AbstractCeramide is the key compound on crossroads of sphingolipid metabolism. The content and composition of ceramides in skeletal muscles have been shown to be affected by prolonged exercise. The aim of this study was to examine the effect of exercise on the activity of key enzymes of ceramide metabolism in skeletal muscles. The experiments were carried out on male Wistar rats (200–250 g) divided into four groups: sedentary, exercised for 30 min, 90 min, and until exhaustion. The activity of serine palmitoyltransferase (SPT), neutral and acid sphingomyelinase (nSMase and aSMase), neutral and alkaline ceramidases (nCDase and alCDase) and the content of ceramide, sphingosine, sphinganine and sphingosine‐1‐phosphate were determined in three types of muscle. We have found that the activity and expression of SPT increase gradually in each muscle with duration of exercise. These changes were followed by elevation in the content of sphinganine. These data indicate that exercise increases de novo synthesis of ceramide. The aSMase activity gradually decreased with duration of exercise in each type of muscle. After exhaustive exercise the activity of both isoforms of ceramidase were reduced in each muscle. The ceramide level depends both on duration of exercise and muscle type. The ceramide level in the soleus and white gastrocnemius decreased after 30 min of running. After exhaustive exercise it was elevated in the soleus and red gastrocnemius. It is concluded that exercise strongly affects the activity of key enzymes involved in ceramide metabolism and in consequence the level of sphingolipid intermediates in skeletal muscles. J. Cell. Biochem. 105: 776–784, 2008. © 2008 Wiley‐Liss, Inc.
FIAT represses bone matrix mineralization by interacting with ATF4 through its second leucine zipper
Authors: Yu Vionnie W.C. , Gauthier Claude , St‐Arnaud René 
Published: August 2008

AbstractWe have characterized FIAT, a 66 kDa leucine zipper (LZ) protein that dimerizes with activating transcription factor 4 (ATF4) to form inactive dimers that cannot bind DNA. Computer analysis identifies three putative LZ motifs within the FIAT amino acid sequence. We have used deletion‐ and/or site‐specific mutagenesis to individually inactivate these motifs in order to identify the functional LZ that mediates the FIAT–ATF4 interaction. Amino acids 194–222 that encode the FIAT LZ2 were deleted (mutant FIAT ZIP2 DEL). We inactivated each zipper individually by replacing two or three leucine residues within each zipper by alanine residues. The engineered mutations were L142A/L149A (mutant M1, first zipper), L208A/L215A/L222A (mutant M2, second zipper), and L441A/L448A (mutant M3, third zipper). MC3T3‐E1 osteoblastic cells with an integrated 1.3 kb mouse osteocalcin gene promoter fragment driving expression of luciferase were transfected with expression vectors for ATF4 and the various FIAT deletion‐ or site‐specific mutants. Inhibition of ATF4‐mediated transcription was compared between wild‐type (WT) and LZ FIAT mutants. The deletion mutant FIAT ZIP2 DEL and the sequence‐specific M2 mutant did not interact with ATF4 and were unable to inhibit ATF4‐mediated transcription. The M1 or M3 mutations did not affect the ability of FIAT to contact ATF4 or to inhibit its transcriptional activity. Stable expression of WT FIAT in osteoblastic cells inhibited mineralization, but not expression of the FIAT ZIP2 DEL and M2 mutants. This structure–function analysis reveals that FIAT interacts with ATF4 and modulates its activity through its second leucine zipper motif. J. Cell. Biochem. 105: 859–865, 2008. © 2008 Wiley‐Liss, Inc.
Psychometric perspectives on diagnostic systems
Authors: Borsboom Denny 
Published: August 2008

AbstractThe author identifies four conceptualizations of the relation between symptoms and disorders as utilized in diagnostic systems such as the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV; American Psychiatric Association, 1994): A constructivist perspective, which holds that disorders are conveniently grouped sets of symptoms; a diagnostic perspective, which holds that disorders are latent classes underlying the symptoms; a dimensional perspective, which holds that symptoms measure latent continua; and a causal systems perspective, which holds that disorders are causal networks consisting of symptoms and direct causal relations between them. Advantages and disadvantages of these conceptualizations are discussed. The author concludes that the psychometric analysis of diagnostic systems is not settled, and that these systems require deeper psychometric analysis than they currently receive. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 1089–1108, 2008.
Estimating WISC‐IV indexes: proration versus linear scaling
Authors: Glass Laura A. , Ryan Joseph J. , Bartels Jared M. , Morris Jeri 
Published: August 2008

AbstractThis investigation compared proration and linear scaling for estimating Wechsler Intelligence Scale for Children–Fourth Edition (WISC‐IV) verbal comprehension (VCI) and perceptual reasoning (PRI) composites from all relevant two subtest combinations. Using 57 primary school students and 41 clinical referrals, actual VCI and PRI scores were highly correlated with estimated index scores based on proration and linear scaling (all rs≥.90). In the school sample, significant mean score differences between the actual and estimated composites were found in two comparisons; however, differences between mean scores were less than three points. No significant differences emerged in the clinical sample. Results indicate that any of the two subtest combinations produced reasonably accurate estimates of actual indexes. There was no advantage of one computational method over the other. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64:1–6, 2008.
Cleaner water using bimetallic nanoparticle catalysts
Authors: Wong Michael S. , Alvarez Pedro J. J. , Fang Yu‐lun , Akçin Nurgül , Nutt Michael O. , Miller Jeffrey T. , Heck Kimberly N. 
Published: August 2008

AbstractGroundwater contaminated by hazardous chlorinated compounds, especially chlorinated ethenes, continues to be a significant environmental problem in industrialized nations. The conventional treatment methods of activated carbon adsorption and air‐stripping successfully remove these compounds by way of transferring them from the water phase into the solid or gas phase. Catalysis is a promising approach to remove chlorinated compounds completely from the environment, by converting them into safer, non‐chlorinated compounds. Palladium‐based materials have been shown to be very effective as hydrodechlorination catalysts for the removal of chlorinated ethenes and other related compounds. However, relatively low catalytic activity and a propensity for deactivation are significant issues that prevent their widespread use in groundwater remediation. Palladium‐on‐gold bimetallic nanoparticles, in contrast, were recently discovered to exhibit superior catalyst activity and improved deactivation resistance. This new type of material is a significant next‐step in the development of a viable hydrodechlorination catalysis technology. Copyright © 2008 Society of Chemical Industry
Dexamethasone inhibition of confluence‐induced apoptosis in human mesenchymal stem cells
Authors: Song In‐Hwan , Caplan Arnold I. , Dennis James E. 
Published: August 2008

AbstractHuman mesenchymal stem cells (MSCs) have been extensively characterized with respect to their in vitro expansion and differentiation potential, especially with respect to osteogenesis. Dexamethasone (Dex) is a well‐known inducer of osteogenic differentiation of MSCs, but little is known about the effect of Dex treatment on apoptosis in MSCs. In this study, apoptosis in MSCs was examined with respect to cell density and Dex supplementation, using DAPI staining and DNA fragmentation ELISA Assay. In MSC cultures initiated at 1.0, 3.0, and 9.0 × 103 cells per cm2, it was found that higher MSC density correlated with increased apoptosis and that this apoptotic effect was diminished in cultures containing 100 nM Dex. MSCs and fibroblasts were co‐cultured, along with empty insert controls, and assayed for apoptosis by ELISA and DAPI counts to determine if soluble factors accounted for the cell density‐related apoptosis. No difference was seen between MSCs cultured with inserts containing either MSCs, fibroblasts, or empty control. To determine cell contact effects, BrdU‐labeled MSCs were cultured alone or with unlabeled chondrocytes at 2× and 8× the number of MSCs, with and without Dex, and apoptosis levels quantified. The results showed increased apoptosis at greater cell densities, and that the amount of apoptosis was greatly diminished in cultures containing Dex. These results show that apoptosis in MSCs is cell density‐related, requires direct cell contact, and that Dex treatment reduces or eliminates this density‐related apoptosis. These results may impact how MSCs should be cultured for clinical applications. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:216–221, 2009
A mouse model for glucocorticoid‐induced osteonecrosis: Effect of a steroid holiday
Authors: Yang Lei , Boyd Kelli , Kaste Sue C. , Kamdem Kamdem Landry , Rahija Richard J. , Relling Mary V. 
Published: August 2008

AbstractGlucocorticoid‐induced osteonecrosis is a common and dose‐limiting adverse event. The goal of this study was to establish a mouse model of glucocorticoid‐induced osteonecrosis suitable for testing the effects of different treatment strategies on its frequency. Fourteen murine strains were screened using various glucocorticoids, routes of administration, and diets. Four‐week‐old male BALB/cJ mice were treated with oral dexamethasone for up to 12 weeks either by continuous dosing or by discontinuous dosing, with or without asparaginase. Histopathological features of the distal femurs were examined by light microscopy. Osteonecrotic lesions were characterized by empty lacunae and osteocyte ghosts in trabecular bone surrounded by necrotic marrow and edema. The incidence of dexamethasone induced osteonecrosis in BALB/cJ mice was 40–45% (4/10 or 5/11) at 12 weeks. The frequency of osteonecrosis trended lower after discontinuous compared to continuous dosing for 12 weeks (8 vs. 45%) (p = 0.06) despite comparable cumulative plasma exposure. Asparaginase hastened the occurrence of osteonecrosis, which was observed as early as 4 weeks and the incidence was 50% after 6 weeks. A mouse model of glucocorticoid‐induced osteonecrosis was established. Discontinuous was less osteonecrotic than continuous dexamethasone treatment, consistent with the possible benefits of a “steroid holiday” seen in clinical settings. Moreover, asparaginase hastened osteonecrosis, indicating that drugs may interact with glucocorticoids to affect osteonecrosis risk. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:169–175, 2009
Investigation of an unnatural amino acid for use as a resonance Raman probe: detection limits and solvent and temperature dependence of the νCN band of 4‐cyanophenylalanine
Authors: Weeks Colin L. , Polishchuk Alexei , Getahun Zelleka , DeGrado William F. , Spiro Thomas G. 
Published: August 2008

AbstractThe incorporation of unnatural amino acids into proteins that act as spectroscopic probes can be used to study protein structure and function. One such probe is 4‐cyanophenylalanine (PheCN), the nitrile group of which has a stretching mode that occurs in a region of the vibrational spectrum that does not contain any modes from the usual components of proteins and whose wavenumber is sensitive to the polarity of its environment. In this work we evaluate the potential of UV resonance Raman spectroscopy for monitoring the sensitivity of the νCN band of PheCN incorporated into proteins to the protein environment. Measurement of the Raman excitation profile of PheCN showed that considerable resonance enhancement of the Raman signal was obtained using UV excitation and the best signal‐to‐noise ratios were obtained with excitation wavelengths of 229 and 244 nm. The detection limit for PheCN in proteins was ∼10 µM, approximately 100‐fold lower than the concentrations used in infrared (IR) studies, which increases the potential applications of PheCN as a vibrational probe. The wavenumber of the PheCN νCN band was strongly dependent on the polarity of its environment; when the solvent was changed from H2O to tetrahydrofuran (THF) it decreased by 8 cm−1. The presence of liposomes caused a similar though smaller decrease in νCN for a peptide, mastoparan X, modified to contain PheCN. The selectivity and sensitivity of resonance Raman spectroscopy of PheCN mean that it can be a useful probe of intra‐ and intermolecular interactions in proteins and opens the door to its application in the study of protein dynamics using time‐resolved resonance Raman spectroscopy. Copyright © 2008 John Wiley & Sons, Ltd.
Isolation and characterisation of a coffee melanoidin fraction
Authors: Gniechwitz Diana , Reichardt Nicole , Ralph John , Blaut Michael , Steinhart Hans , Bunzel Mirko 
Published: August 2008

AbstractBACKGROUND: Melanoidins contribute to the colour and flavour of coffee brews and are also reported to be physiologically active components. However, structural information about coffee melanoidins is rare and current models are supported by few data.RESULTS: Using hydrophobic interaction chromatography (HIC), melanoidin fractions were isolated from different high‐molecular‐weight fractions of coffee brews obtained by ultrafiltration. Generally, melanoidin fractions isolated by HIC showed three‐ to fourfold higher antioxidant activities than the remaining high‐molecular‐weight material in the ultrafiltration fractions. Melanoidin fractions showed an intense brown colour: aqueous solutions with a concentration as low as 40 µg mL−1 were distinguishable from pure water. The melanoidin fractions contained less than 6% each of releasable carbohydrates and amino acids. The molecular masses of the melanoidins were estimated to be between 3 and 22 kDa, irrespective of the ultrafiltration fraction from which they were obtained. Two‐dimensional nuclear magnetic resonance studies revealed an enrichment of phenolic/aromatic/olefinic structural units and did not support the idea of intact ferulate or caffeate moieties integrated into the melanoidin polymer.CONCLUSION: These studies support melanoidin models describing them as high‐molecular‐weight compounds themselves as opposed to models describing them as low‐molecular‐weight chromophores bound to polysaccharides or proteins. Phenolic constituents are more likely integrated into melanoidins as condensed phenolics than as intact hydroxycinnamates from chlorogenic acids. Copyright © 2008 Society of Chemical Industry
Orbitrap mass spectrometry: Instrumentation, ion motion and applications
Authors: Perry Richard H. , Cooks R. Graham , Noll Robert J. 
Published: August 2008

AbstractSince its introduction, the orbitrap has proven to be a robust mass analyzer that can routinely deliver high resolving power and mass accuracy. Unlike conventional ion traps such as the Paul and Penning traps, the orbitrap uses only electrostatic fields to confine and to analyze injected ion populations. In addition, its relatively low cost, simple design and high space‐charge capacity make it suitable for tackling complex scientific problems in which high performance is required. This review begins with a brief account of the set of inventions that led to the orbitrap, followed by a qualitative description of ion capture, ion motion in the trap and modes of detection. Various orbitrap instruments, including the commercially available linear ion trap–orbitrap hybrid mass spectrometers, are also discussed with emphasis on the different methods used to inject ions into the trap. Figures of merit such as resolving power, mass accuracy, dynamic range and sensitivity of each type of instrument are compared. In addition, experimental techniques that allow mass‐selective manipulation of the motion of confined ions and their potential application in tandem mass spectrometry in the orbitrap are described. Finally, some specific applications are reviewed to illustrate the performance and versatility of the orbitrap mass spectrometers. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 27: 661–699, 2008
Downstream targets of heterogeneous nuclear ribonucleoprotein A2 mediate cell proliferation
Authors: He Yaowu , Rothnagel Joseph A. , Epis Michael R. , Leedman Peter J. , Smith Ross 
Published: August 2008

AbstractOver‐expression of heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 is regarded as an early marker for several cancers. This protein is associated with proto‐oncogenes and tumor suppressor genes and has itself been described as a proto‐oncogene. Our earlier experiments drew a connection between hnRNP A2/B1 levels and cell proliferation and raised the possibility that this protein contributes to the uncontrolled cell division that characterizes cancer. Limited knowledge of the downstream targets of hnRNP A2/B1 has, however, precluded a clear understanding of their roles in cancer cell growth. To define the pathways in which this protein acts we have now carried out microarray experiments with total RNA from Colo16 epithelial cells transfected with an shRNA that markedly suppresses hnRNP A2/B1 expression. The microarray data identified 123 genes, among 22 283 human gene probe sets, with altered expression levels in hnRNP A2/B1‐depleted cells. Ontological analysis showed that many of these downstream targets are involved in regulation of the cell cycle and cell proliferation and that this group of proteins is significantly over‐represented amongst the affected proteins. The changes detected in the microarray experiments were confirmed by real‐time PCR for a subset of proliferation‐related genes. Immunoprecipitation‐RT‐PCR demonstrated that hnRNP A2/B1 formed complexes with the transcripts of many of the verified downstream genes, suggesting that hnRNP A2/B1 contributes to the regulation of these genes. These results reinforce the conclusion that hnRNP A2/B1 is associated with cellular processes that affect the cell cycle and proliferation. © 2008 Wiley‐Liss, Inc.
Postconditioning attenuates ischemia‐reperfusion injury in rat skin flap
Authors: Moon Jun Gyu , Lim Hong Chul , Gye Myeoung Ryoung , Oh Joon Seo , Park Jong Woong 
Published: August 2008

AbstractReperfusion injury by the abrupt restoration of circulation after the prolonged ischemia has been remained unsolved problem in the reconstructive microsurgery. We tested the hypothesis that a procedure of intermittent interruption of reperfusion, i.e., postconditioning (post‐con) attenuates ischemia/reperfusion (I/R) injury of rat epigastric skin flap. A complete 4 hours of ischemia was generated by occlusion of the pedicle of dissected flap. The post‐con procedure was started at the end of ischemia. A cycle of 15 seconds of full reperfusion, followed by 15 seconds of complete reocclusion was repeated six times (3 min of total intervention) prior to the unlimited reperfusion. Flap necrosis area of post‐con group was compared with sham (no ischemic exposure) and control (4 hours of ischemia followed by full reperfusion without intervention) groups at postreperfusion day 5. Histology and MPO activities of flaps were evaluated. The post‐con group showed significantly reduced flap necrosis at the end of 5 days of reperfusion compared with the control. Decreased inflammatory cell infiltration and MPO activity indicated post‐con attenuated acute inflammatory reaction caused by I/R. This study reports for the first time that ischemic post‐con effectively attenuates skin flap I/R injury. With further study, post‐con may eventually be clinically applicable for the I/R injury as an “after‐injury strategy.” © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Meat‐based functional foods for dietary equilibrium omega‐6/omega‐3
Authors: Reglero Guillermo , Frial Paloma , Cifuentes Alejandro , García‐Risco Mónica R. , Jaime Laura , Marin Francisco R. , Palanca Vicente , Ruiz‐Rodríguez Alejandro , Santoyo Susana , Señoráns Francisco J. , Soler‐Rivas Cristina , Torres Carlos , Ibañez Elena 
Published: August 2008

AbstractNutritionists encourage improving the diet by combining meat products with fish or other sea‐related foods, in order to equilibrate the omega‐6/omega‐3 ratio. Strong scientific evidence supports the beneficial health effects of a balanced omega‐6/omega‐3 PUFA (poly unsaturated fatty acids) diets. In the present work, the scientific bases of new functional meat products with both a balanced omega‐6/omega‐3 ratio and a synergic combination of antioxidants are discussed. The aim is to contribute to the dietary equilibrium omega‐6/omega‐3 and to increase the antioxidant intake. Conventional meat products supplemented with a specific fatty acids and antioxidants combination led to functional foods with healthier nutritional parameters.
Isolation of tyrosinase inhibitors from Artocarpus heterophyllus and use of its extract as antibrowning agent
Authors: Zheng Zong‐Ping , Cheng Ka‐Wing , To James Tsz‐Kin , Li Haitao , Wang Mingfu 
Published: August 2008

AbstractA new furanoflavone, 7‐(2,4‐dihydroxyphenyl)‐4‐hydroxy‐2‐(2‐hydroxy propan‐2‐yl)‐2, 3‐dihydrofuro(3, 2‐g)chromen‐5‐one (artocarpfuranol, 1), together with 14 known compounds, dihydromorin (2), steppogenin (3), norartocarpetin (4), artocarpanone (5), artocarpesin (6), artocarpin (7), cycloartocarpin (8), cycloartocarpesin (9), artocarpetin (10), brosimone I (11), cudraflavone B (12), carpachromene (13), isoartocarpesin (14), and cyanomaclurin (15) were isolated from the wood of Artocarpus heterophyllus. Their structures were identified by interpretation of MS, 1H‐NMR, 13C‐NMR, HMQC, and HMBC spectroscopic data. Among them, compounds 1–6 and 14 showed strong mushroom tyrosinase inhibitory activity with IC50 values lower than 50 μM, more potent than kojic acid (IC50 = 71.6 μM), a well‐known tyrosinase inhibitor. In addition, extract of A. heterophyllus was evaluated for its antibrowning effect on fresh‐cut apple slices. It was discovered that fresh‐cut apple slices treated by dipping in solution of 0.03 or 0.05% of A. heterophyllus extract with 0.5% ascorbic acid did not undergo any substantial browning reaction after storage at room temperature for 24 h. The antibrowning effect was significantly better than samples treated with the extract (0.03 or 0.05%) or ascorbic acid (0.5%) alone. The results provide preliminary evidence supporting the potential of this natural extract as antibrowning agent in food systems.