bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonenzymatic glycation of histones in vitro and in vivo
Authors: Talasz Heribert , Wasserer Sara , Puschendorf Bernd 
Published: October 2004

AbstractPurified histones in solution, purified nuclei, or whole endothelial cells in cell culture were used to study the reactivity of histones with various sugars. The sugar incubation of purified histones produced nonenzymatic glycation and formation of histone cross‐links showing disappearance of individual histone molecules and appearance of dimers and polymers in SDS–PAGE. In solution, core histones react considerably faster with sugars as compared to H1 histones. In sugar‐incubated nuclei where histones are nucleosomally organized, H1 histones, which are located at the periphery of the nucleosome, and H2A‐H2B dimers, which are associated with the central H32‐H42 tetramer, are more reactive as compared to H3 and H4 histones, which are most protected from the glycation reaction. Our in vivo experiments using endothelial cells show that high concentrations of ribose are able to generate protein cross‐links paralleled by apoptotic cell death. High concentrations of glucose or fructose do not increase histone glycation or cell death, even after 60 days of incubation of endothelial cells. In long‐time glucose‐ or fructose‐treated cells, under nondenaturing and nonreducing SDS–PAGE conditions part of the H3 histones shifted away from their normal location. Because it is known that the mitochondrial production of reactive oxygen species (ROS) increases after hyperglycaemia, we hypothesize that ROS could be responsible for the formation of a disulphide bridge between the side chain of the cysteine residues of H3 molecules. J. Cell. Biochem. 85: 24–34, 2002. © 2002 Wiley‐Liss, Inc.
Involvement of cAMP but not PKA in the increase of corticosterone secretion in rat zona fasciculata‐reticularis cells by aging
Authors: Lo Ming‐Jae , Wang Paulus S. 
Published: October 2004

AbstractThe effects and mechanisms of aging on corticosterone secretion in zona fasciculata‐reticularis (ZFR) cells of ovariectomized (Ovx) rats were studied. Young (3‐month) and old (24‐month) female rats were Ovx for 4 days before decapitation. ZFR cells were isolated and incubated with different hormones or reagents at 37°C for 30 min. Aging increased the basal secretion of corticosterone both in vivo and in vitro. The adrenocorticotropin (ACTH)‐, forskolin‐, 3‐isobutyl‐l‐methylxanthine (IBMX)‐, 8‐bromo‐adenosine 3′,5′‐cyclic monophosphate (8‐Br‐cAMP)‐, and ovine prolactin (oPRL)‐stimulated release of corticosterone by ZFR cells was greater in old than in young Ovx rats. H89, an inhibitor of protein kinase A (PKA), decreased the production of corticosterone in ZFR cells from young but not old Ovx rats. Forskolin‐, or IBMX‐induced production of cAMP was greater in old than in young Ovx animals, which correlated with the increase of corticosterone production by aging. The activity of 11β‐hydroxylase that converts deoxycorticosterone (DOC, 10−9 or 10−8 M) to corticosterone in rat ZFR cells was decreased by age. However, the corticosterone production in response to high dose of DOC (10−7 M) was indifferent between young and old groups. These results suggest that aging increases corticosterone production in Ovx rats via a mechanism in part associated with an increase of adenylyl cyclase activity and a decrease of phosphodiesterase activity, and then an increase of the generation of cAMP, but not related to either PKA activity or 11β‐hydroxylase. J. Cell. Biochem. 85: 35–41, 2002. © 2002 Wiley‐Liss, Inc.
Modulation of the proliferation and differentiation of human mesenchymal stem cells by copper
Authors: Rodríguez J. Pablo , Ríos Susana , González Mauricio 
Published: October 2004

AbstractCopper plays important functional roles in bone metabolism and turnover. It is known that it is essential for normal growth and development of the skeleton in humans and in animals. Although at present the exact role that copper plays in bone metabolism is unknown, bone abnormalities are a feature of severe copper deficiency. Osteoblasts are derived from mesenchymal stem cells (MSCs) present in bone marrow stroma, which are able to differentiate into bone, adipocytes, and other cell phenotypes. Excess adipogenesis in postmenopausal women may occur at the expense of osteogenesis and, therefore, may be an important factor in the fragility of postmenopausal bone. The purpose of this study was to evaluate whether an increase of the extracellular concentration of copper affects the ability of MSCs to differentiate into osteoblasts or adipocytes. The results showed that copper modified both the differentiation and the proliferative activity of MSCs obtained from postmenopausal women. Copper (50 μM) diminished the proliferation rate of MSCs, increasing their ability to differentiate into the osteogenic and the adipogenic lineages. Copper induced a 2‐fold increase in osteogenic differentiation of MSCs, measured as a increase in calcium deposition. Copper (5 and 50 μM) diminished the expression of alkaline phosphatase (50 and 80%, respectively), but induced a shift in the expression of this enzyme to earlier times during culture. Copper also induced a 1.3‐fold increase in the adipogenic differentiation of MSCs. It is concluded that copper stimulates MSC differentiation, and that this is preferentially towards the osteogenic lineage. J. Cell. Biochem. 85: 92–100, 2002. © 2002 Wiley‐Liss, Inc.
Analysis of the carboxypeptidase D cytoplasmic domain: Implications in intracellular trafficking*
Authors: Kalinina Elena , Varlamov Oleg , Fricker Lloyd D. 
Published: October 2004

AbstractMetallocarboxypeptidase D (CPD) is a type 1 transmembrane protein that functions in the processing of proteins that transit the secretory pathway. Previously, CPD was found to be enriched in the trans Golgi network (TGN) and to cycle between this compartment and the cell surface. In the present study, the roles of specific regions of the CPD cytosolic tail in intracellular trafficking were investigated in the AtT‐20 cell line. When the CPD transmembrane region and cytosolic tail are attached to the C‐terminus of albumin, this protein is retained in the TGN and cycles to the cell surface. Deletion analysis indicates that a C‐terminal region functions in TGN‐retention; removal of 10 amino acids from the C‐terminus greatly increases the amount of fusion protein that enters nascent vesicles, which bud from the Golgi, but does not affect the half‐life of the fusion protein or the ability of cell surface protein to return to the TGN. Because the 10‐residue deletion disrupts a casein kinase 2 (CK2) consensus site, the two Thr in this site (TDT) were mutated to either Ala (ADA) or Glu (EDE). Neither mutation has an increased rate of budding from the TGN, although the ADA mutant has a shorter half‐life than either the wild type sequence or the EDE mutant. Adaptor protein‐1 and ‐2 bind to most of the deletion mutants, the EDE point mutant, and the CK2‐phosphorylated CPD tail, but not to the wild type tail. Taken together, these results suggest that CPD localization to the TGN requires both static retention involving the C‐terminal domain and phosphorylation at a CK2 site, which regulates the binding of adaptor proteins. J. Cell. Biochem. 85: 101–111, 2002. © 2002 Wiley‐Liss, Inc.
Cardiac troponin I sense‐antisense RNA duplexes in the myocardium
Authors: Podlowski Svenia , Bramlage Peter , Baumann Gert , Morano Ingo , Luther Hans Peter 
Published: October 2004

AbstractNatural antisense RNA is now thought to regulate, at least in part, a growing number of eukaryotic genes. It is becoming increasingly apparent that such endogenous antisense RNA molecules may modulate gene expression in a manner analogous to synthetic oligomers. Here, we report the detection of antisense‐orientated RNA transcripts of cardiac specific troponin I in rat and human myocardium. Interestingly, the different sizes of the rat and human antisense cTNI transcripts suggest species‐specific reverse transcription initiation sites. Moreover, for the first time in cardiomyocytes, we could demonstrate in vivo duplex formation between sense and antisense transcripts. The existence of antisense‐sense duplexes represents compelling evidence and a potential mechanism for endogenous antisense transcript‐mediated modulation of mRNA translation. The potential effect of attenuating translation was illustrated by in vitro and in vivo model systems. Testing several oligonucleotides based on the natural antisense sequences, the optimal region for inhibition of translation was identified as being close to the translational start codon. J. Cell. Biochem. 85: 198–207, 2002. © 2002 Wiley‐Liss, Inc.
O‐glycosylation of the nuclear forms of Pax‐6 products in quail neuroretina cells
Authors: Lefebvre Tony , Planque Nathalie , Leleu Denis , Bailly Manuella , Caillet‐Boudin Marie‐Laure , Saule Simon , Michalski Jean‐Claude 
Published: October 2004

AbstractMany transcription factors are demonstrated as being glycosylated with O‐N‐acetylglucosamine (GlcNAc) residue in transfected insect cell lines, but rarely in the original cells. For the first time, we demonstrate the O‐GlcNAc modification of the p48/p46 Pax‐6 gene (a developmental control gene involved in the eye morphogenesis) products in the quail neuroretina (QNR). In conjunction with a systematic PNGase F treatment, we used wheat germ agglutinin (WGA) binding, in vitro labeling with bovine galactosyltransferase, and labeling of cultured QNR with [14C]GlcNH2. Glycosylated forms of Pax‐6 proteins were found in the nucleus of the neuroretina cells. WGA‐selected Pax‐6 proteins produced in the reticulocyte lysate were able to bind a DNA target, as well as to the unglycosylated form. The O‐GlcNAc may, however, modulate protein interactions, mainly with other factors involved in the transcription process. Characterization of products released after reductive alkaline treatment of the proteins clearly demonstrates that N‐acetylglucosamine is directly linked to serine or threonine residues. Examination of Pax‐6 primary sequence allowed us to determine potential O‐GlcNAc attachment sites. Most of these expected glycosylation sites appear to be located on the two DNA binding domains and on the carboxyterminal transactivation domain, while experimental evidence taken from WGA‐selected proteins experiment points in favor of a main localization on the paired‐box domain. J. Cell. Biochem. 85: 208–218, 2002. © 2002 Wiley‐Liss, Inc.
Characterization of the osteoblast‐like cell phenotype under microgravity conditions in the NASA‐approved rotating wall vessel bioreactor (RWV)
Authors: Rucci Nadia , Migliaccio Silvia , Zani Bianca Maria , Taranta Anna , Teti Anna 
Published: October 2004

AbstractWeightlessness induces bone loss in humans and animal models. We employed the NASA‐approved Rotating Wall Vessel bioreactor (RWV) to develop osteoblast‐like cell cultures under microgravity and evaluate osteoblast phenotype and cell function. Rat osteoblast‐like cell line (ROS.SMER#14) was grown in the RWV at a calculated gravity of 0.008g. For comparison, aliquots of cells were grown in conventional tissue culture dishes or in Non‐Rotating Wall Vessels (N‐RWV) maintained at unit gravity. In RWV, osteoblasts showed high levels of alkaline phosphatase expression and activity, and elevated expression of osteopontin, osteocalcin, and bone morphogenetic protein 4 (BMP‐4). In contrast, the expression of osteonectin, bone sialoprotein II and BMP‐2 were unaltered compared to cells in conventional culture conditions. These observations are consistent with a marked osteoblast phenotype. However, we observed that in RWV osteoblasts showed reduced proliferation. Furthermore, DNA nucleosome‐size fragmentation was revealed both morphologically, by in situ staining with the Thymine‐Adenine binding dye bis‐benzimide, and electrophoretically, by DNA laddering. Surprisingly, no p53, nor bcl‐2/bax, nor caspase 8 pathways were activated by microgravity, therefore the intracellular cascade leading to programmed cell death remains to be elucidated. Finally, consistent with an osteoclast‐stimulating effect by microgravity, osteoblasts cultured in RWV showed upregulation of interleukin‐6 (IL‐6) mRNA, and IL‐6 proved to be active at stimulating osteoclast formation and resorbing activity in vitro. We conclude that under microgravity, reduced osteoblast life span and enhanced IL‐6 expression may result in inefficient osteoblast‐ and increased osteoclast‐activity, respectively, thus potentially contributing to bone loss in individuals subjected to weightlessness. J. Cell. Biochem. 85: 167–179, 2002. © 2002 Wiley‐Liss, Inc.
Immunohistochemical localization of type 2 inositol 1,4,5‐trisphosphate receptor to the nucleus of different mammalian cells
Authors: Laflamme Karina , Domingue Olivier , Guillemette Benoit I. , Guillemette Gaétan 
Published: October 2004

AbstractThe inositol 1,4,5‐trisphosphate receptor (InsP3R) is a ligand‐gated Ca2+ channel responsible for the release of Ca2+ from intracellular stores in the response of a wide variety of cells to external stimuli. Molecular cloning studies have revealed the existence of three types of InsP3R encoded by distinct genes. In the study presented here, we used selective anti‐InsP3R antibodies to determine the intracellular location of each InsP3R subtype in bovine aortic endothelial cells, bovine adrenal glomerulosa cells, and COS‐7 cells. InsP3R1 was found to be widely distributed throughout the cytosol and most abundantly in the perinuclear region identified as the endoplasmic reticulum (co‐localization with protein disulfide isomerase). The intracellular location of InsP3R3 was similar to that of InsP3R1. Surprisingly, InsP3R2 was found mostly associated to the cell nucleus. This observation was made with two antibodies recognizing different epitopes on InsP3R2. Binding studies revealed the presence of a high affinity‐binding site for [3H] InsP3 on purified nuclei from bovine adrenal cortex. Confocal images showed that InsP3R2 was not confined to the nuclear envelope but was distributed relatively uniformly within the nucleus. Our results demonstrate that the three types of InsP3R are not similarly distributed within a specific cell type. Our results also suggest the existence of an intranuclear membrane network on which InsP3R2 is abundantly expressed. J. Cell. Biochem. 85: 219–228, 2002. © 2002 Wiley‐Liss, Inc.
Functional expression of human heme oxygenase‐1 (HO‐1) driven by HO‐1 promoter in vitro and in vivo
Authors: Quan Shuo , Yang Liming , Shenouda Sylvia , Jiang Houli , Balazy Michael , Schwartzman Michal L. , Shibahara Ichiyo , Shinohara Kousei , Abraham Nader G. 
Published: October 2004

AbstractWe developed a retrovirus‐mediated human heme oxygenase‐1 (HO‐1) gene expression system and assessed the impact of heme on the inducibility of the HO‐1 gene in rat lung microvessel (RLMV) endothelial cells and in newborn Sprague‐Dawley (SD) rats. Overexpression of the HO‐1 gene driven by HO‐1 promoter (HOP) resulted in an increase in HO‐1 protein and HO activity by 4.8‐ and 1.3‐fold, respectively, compared to the viral LTR promoter. The increased HO‐1 gene expression was associated with the enhancement of CO production. In cells transduced by HOP‐driven HO‐1 gene, there was a decrease in basal cyclooxygenase (COX) activity as measured by PGE2. The degree of HO‐1 expression and, consequently, the levels of cellular heme were directly related to COX activity. Supplementation with heme markedly increased PGE2 and cGMP synthesis. In all (6/6) of newborn SD rats injected with retrovirus LSN‐HOP‐HO‐1, both HO‐1 and neor transcripts were expressed in tissues. We hypothesize that degree of HO‐1 gene expression resulted in a differential rate of cellular heme‐dependent enzyme gene expression, which may play a vital role in maintaining cellular homeostasis. J. Cell. Biochem. 85: 410–421, 2002. © 2002 Wiley‐Liss, Inc.
Improved intermolecular force field for molecules containing H, C, N, and O atoms, with application to nucleoside and peptide crystals
Authors: Williams Donald E. 
Published: October 2004

AbstractA new intermolecular force field for nitrogen atoms in organic molecules was derived from a training dataset of 76 observed azahydrocarbon crystal structures and 11 observed heats of sublimation. The previously published W99 force field for hydrogen, carbon, and oxygen was thus extended to include nitrogen atoms. Nitrogen atoms were divided into four classes: N(1) for triply bonded nitrogen, N(2) for nitrogen with no bonded hydrogen (except the triple bonded case), N(3) for nitrogen with one bonded hydrogen, and N(4) for nitrogen with two or more bonded hydrogens. H(4) designated hydrogen bonded to nitrogen. Wavefunctions of 6‐31g** quality were calculated for each molecule and the molecular electric potential (MEP) was modeled with net atomic and supplementary site charges. Lone pair electron charge sites were included for nitrogen atoms where appropriate, and methylene bisector charges were used for CH2 and CH3 groups when fitting the MEP. XH bond distances were set to standard values for the wave function calculation and then foreshortened by 0.1 Å for the MEP and force field fitting. Using the force field optimized to the training dataset, each azahydrocarbon crystal structure was relaxed by intermolecular energy minimization. Predicted maximum changes in unit cell edge lengths for each crystal were 3% or less. The complete force field for H, C, N, and O atoms was tested by intermolecular energy relaxation of nucleoside and peptide molecular crystals. Even though these molecules were not included in any of the training datasets for the force field, agreement with their observed crystal structures was very good, with predicted unit cell edge shifts usually less than 2%. These tests included crystal structures of representatives of all eight common nucleosides found in DNA and RNA, 15 dipeptides, four tripeptides, two tetrapeptides, and a pentapeptide with two molecules in the asymmetric unit. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1154–1166, 2001
Quantum chemical characterization of the cytosine: 2‐Aminopurine base pair
Authors: Sherer Edward C. , Cramer Christopher J. 
Published: October 2004

AbstractThe nature of the base pairing between cytosine and 2‐aminopurine is investigated by means of quantum mechanical calculations including electron correlation and accounting for the effects of aqueous solvation. At neutral pH, both a neutral wobble base pair and a Watson–Crick‐like base pair having a protonated 2‐aminopurine are predicted to be close to one another in energy; other previously proposed forms are found to be too high in energy to be of significant chemical interest. Accounting for the energetics of helix embedding suggests that the equilibrium between the two low‐energy motifs is quite sensitive to local environment. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1167–1179, 2001
An improved GROMOS96 force field for aliphatic hydrocarbons in the condensed phase
Authors: Schuler Lukas D. , Daura Xavier , van Gunsteren Wilfred F. 
Published: October 2004

AbstractOver the past 4 years the GROMOS96 force field has been successfully used in biomolecular simulations, for example in peptide folding studies and detailed protein investigations, but no applications to lipid systems have been published yet. Here we provide a detailed investigation of aliphatic liquid systems. For liquids of larger aliphatic chains, n‐heptane and longer, the standard GROMOS96 parameter sets 43A1 and 43A2 yield a too low pressure at the experimental density. Therefore, a reparametrization of the GROMOS96 force field regarding aliphatic carbons was initiated. The new force field parameter set 45A3 shows considerable improvements for n‐alkanes, cyclo‐, iso‐, and neoalkanes and other branched aliphatics. Liquid densities and heat of vaporization are reproduced for almost all of these molecules. Excellent agreement is found with experiment for the free energy of hydration for alkanes. The GROMOS96 45A3 parameter set should, therefore, be suitable for application to lipid aggregates such as membranes and micelles, for mixed systems of aliphatics with or without water, for polymers, and other apolar systems that may interact with different biomolecules. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1205–1218, 2001
Presenting problems among treatment‐seeking gay, lesbian, and bisexual youth
Authors: Hart Trevor A. , Heimberg Richard G. 
Published: October 2004

AbstractGay, lesbian, and bisexual youth are at risk for a variety of clinical problems amenable to psychotherapeutic intervention. However, many psychotherapists may be unaware of the difficulties faced by this population. The purpose of this article is to familiarize therapists with presenting complaints common to psychotherapy‐seeking gay, lesbian, and bisexual youth. Some of these problems include homophobia among family, peers, and authority figures (often expressed at school or at work), depression, suicidality, social anxiety, and body image disturbance. We illustrate these important issues via four case examples. © 2001 John Wiley & Sons, Inc. J Clin Psychol/In Session 57: 615–627, 2001.
A survival analysis of clinically significant change in outpatient psychotherapy
Authors: Anderson Edward M. , Lambert Michael J. 
Published: October 2004

AbstractThe number of sessions required to produce meaningful change has not been assessed adequately, in spite of its relevance to current clinical practice. Seventy‐five clients attending outpatient therapy at a university‐affiliated clinic were tracked on a weekly basis using the Outcome Questionnaire (Lambert et al., 1996) in order to determine the number of sessions required to attain clinically significant change (CS). Survival analysis indicated that the median time required to attain CS was 11 sessions. When current data were combined with those from an earlier investigation (Kadera, Lambert, and Andrews, 1996), it was found that clients with higher levels of distress took 8 more sessions to reach a 50% CS recovery level than clients entering with lower levels of distress. At a six‐month follow‐up, CS gains appeared to have been maintained. Other indices of change also were examined (reliable change, average change per session). The implications of these results for allocating mental‐health benefits, such as the number of sessions provided through insurance, are discussed. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 875–888, 2001.
Suicidal ideation and help‐negation: Not just hopelessness or prior help
Authors: Deane Frank P. , Wilson Coralie J. , Ciarrochi Joseph 
Published: October 2004

AbstractFew distressed young people seek professional psychological help and little is known about what sources of help young people seek for different problems. In suicidal youth, the process of help‐negation may exacerbate poor help‐seeking. Three hundred and two undergraduate university students completed a questionnaire measuring suicidal ideation, hopelessness, prior help‐seeking experience, and help‐seeking intentions. Participants indicated they would seek help from different sources of help for different types of problems, but friends consistently were rated as the most likely source of help. Help‐negation was suggested by higher levels of suicidal ideation being associated with lower help‐seeking intentions. However, the negative suicidal ideation/help‐seeking‐intentions relationship was not explained by hopelessness or prior help‐seeking. Help‐negation appears to involve more than just negative expectations regarding the future. The discussion proposes social problem‐solving orientation as one of a number of potential explanatory variables. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 901–914, 2001.