bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calcium phosphate coatings obtained by Nd:YAG laser cladding: Physicochemical and biologic properties
Authors: Lusquiños F. , De Carlos A. , Pou J. , Arias J. L. , Boutinguiza M. , León B. , Pérez‐Amor M. , Driessens F. C. M. , Hing K. , Gibson I. , Best S. , Bonfield W. 
Published: February 2003

AbstractThe plasma spray (PS) technique is the most popular method commercially in use to produce calcium phosphate (CaP) coatings to promote fixation and osteointegration of the cementless prosthesis. Nevertheless, PS has some disadvantages, such as the poor coating‐to‐substrate adhesion, low mechanical strength, and brittleness of the coating. In order to overcome the drawbacks of plasma spraying, we introduce in this work a new method to apply a CaP coating on a Ti alloy using a well‐known technique in the metallurgical field: laser surface cladding. The physicochemical characterization of the coatings has been carried out by means of X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X‐ray analysis (EDX). The biologic properties of the coatings have been assessed in vitro with human osteoblast‐like MG‐63 cells. The overall results of this study affirm that the Nd:YAG laser cladding technique is a promising method in the biomedical field. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 630–637, 2003
Cell adhesion on supported lipid bilayers
Authors: Andersson Ann‐Sofie , Glasmästar Karin , Sutherland Duncan , Lidberg Ulf , Kasemo Bengt 
Published: February 2003

AbstractThe cell and protein repellent properties of supported phospholipid bilayer (SPB) membranes were investigated. The SPBs were prepared by vesicle adsorption on SiO2 surfaces. The vesicles of phosphatidylcholine fuse and rupture, and form a supported bilayer covering the surface. We carried out cell culture experiments on several surfaces, including SPBs, using two types of epithelial cells to address the cell adhesional properties. The Quartz Crystal Microbalance Dissipation (QCM‐D) technique was used to monitor the SPB formation and subsequent protein adsorption. Neither cell type adhered or proliferated on SiO2 surfaces coated with SPBs, whereas both cell types adhered and proliferated on the three control surfaces of SiO2, tissue culture glass, and TiO2. The QCM‐D measurements showed that about two orders of magnitude less mass adsorbed on a SPB surface compared to a TiO2 surface, from serum‐containing media (10% fetal bovine serum). The reduced adsorption on the SPB is a likely explanation for the nondetectable epithelial cell adhesion on the SPB surface. Biomembranes are therefore attractive candidate systems to achieve alternating cell‐resistant and cell‐interacting regions on surfaces, by including specific cell‐binding proteins in the latter regions. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 622–629, 2003
Putative role for EPC‐1/PEDF in the G0 growth arrest of human diploid fibroblasts
Authors: Pignolo Robert J. , Francis Mary Kay , Rotenberg Mitch O. , Cristofalo Vincent J. 
Published: February 2003

AbstractEPC‐1/PEDF expression is closely associated with reversible growth arrest in normal human diploid fibroblast‐like (HDF) cells and is diminished with proliferative senescence in vitro. EPC‐1 expression in HDF cells is induced under conditions of density‐dependent contact inhibition and growth factor deprivation. Antiserum generated against EPC‐1 recognizes a secreted protein of approximately 50 kDa from medium conditioned by early passage HDF cells, but not from senescent cells. The addition of EPC‐1 antiserum to early population doubling level (PDL) cultures near the plateau phase of growth significantly increases the number of cells entering DNA synthesis. Affinity purified EPC‐1 antibodies alone enhance the ability of near plateau‐phase early PDL WI‐38 cells to synthesize DNA by as much as threefold. Further, the addition of recombinant EPC‐1 (rEPC‐1) to logarithmically growing cells resulted in a marked decrease in the ability of these cells to enter DNA synthesis. We also demonstrate the loss of EPC‐1 expression in WI‐38 and IMR‐90 HDF cell lines with both senescence and simian virus 40 (SV40) transformation. The loss of EPC‐1 expression with SV40 transformation occurs at the level of steady‐state mRNA and protein accumulation with genomic EPC‐1 sequences grossly intact. Taken together, these results suggest that EPC‐1 may play a role in the entry of early passage fibroblasts into a G0 state or the maintenance of such a state once reached. © 2003 Wiley‐Liss, Inc.
Inflammatory mediators and reversible myocardial dysfunction
Authors: Kan Hong , Finkel Mitchell S. 
Published: February 2003

AbstractA variety of seemingly unrelated clinical conditions manifest the same effects on the heart. These effects include: (1) reversible myocardial dysfunction, (2) β‐adrenergic desensitization, and (3) activation of inflammatory mediators. We provide evidence supporting a role for cytokines, mitogen activated protein kinases (MAP kinases), and nitric oxide (NO) as common mediators of reversible myocardial dysfunction and β‐adrenergic desensitization. Data from animal models and human studies support a pathogenic role for these inflammatory mediators in ischemic as well as non‐ischemic myocardial dysfunction. It is suggested that compensatory cellular programs are activated to provide short‐term protection from brief periods of ischemia and infection. Continuous activation of these compensatory pathways leads to cardiomyopathy and chronic (congestive) heart failure. Elucidating the signaling pathways involved has the potential to provide the opportunity to exploit the cardioprotective advantages of these agents without bearing the burden of excessive stimulation. © 2003 Wiley‐Liss, Inc.
Hydrocortisone has a protective effect on CyclosporinA‐induced cardiotoxicity
Authors: Florio Salvatore , Ciarcia Roberto , Crispino Luca , Pagnini Ugo , Ruocco Antonio , Kumar Christine , D'Andrilli Giuseppina , Russo Ferdinando 
Published: February 2003

AbstractCyclosporinA (CsA) is an immunosuppressive drug which induces severe adverse effects such as cardiotoxicity and nephrotoxicity. In several therapeutic protocols CsA is used in association with corticosteroids to obtain better therapeutic results. Recently, our studies showed that CsA increases blood pressure while inhibit Nitric Oxide (NO) production in vivo. In this study we evaluated in rat cardiomyocytes the effects of CsA, used alone or in association with Hydrocortisone (HY), on intracellular calcium concentration, NO production and lipid peroxidation (MDA level). Our results demonstrated that CsA increased intracellular calcium and such effect was dose‐dependent. HY used alone, slightly decreased intracellular calcium, while dramatically reduced CsA‐induced calcium fluxes. CsA (3.2 μM) increased lipid peroxidation and this effect was blunted by HY. Both CsA and HY inhibited NO production in rat cardiomyocytes acting on this pathway synergically. Our results demonstrated that in rat cardiomyocytes, CsA toxicity is due to a calcium overload, which in turn induce lipid peroxidation and determines oxidative stress‐induced cell injury. Treatment with HY effectively inhibits CsA‐induced toxicity, decreasing lipid peroxidation as well as calcium intracellular concentration. Our findings seem to suggest that glucocorticoids may be effective in reducing CsA‐induced cardiotoxicity at concentrations which are consistent with current therapeutic doses. © 2003 Wiley‐Liss, Inc.
Characterization of apoptosis signal transduction pathways in HL‐5 cardiomyocytes exposed to ischemia/reperfusion oxidative stress model
Authors: Cicconi Simona , Ventura Natascia , Pastore Donatella , Bonini Paolo , Nardo Paolo Di , Lauro Renato , Marlier Lionel N.J.L. 
Published: February 2003

AbstractDuring ischemia/reperfusion (I/R), cardiomyocytes are exposed to sudden lack of nutrients and successively to radical oxygen species (ROS). In the present study, we used the HL‐5 cardiac atrial myocyte cell line exposed to serum/glucose depletion added or not in H2O2 to mimic ROS during ischemia, then replaced in their standard culture medium to simulate reperfusion. We investigated the effects of serum/glucose depletion combined or not to ROS exposure on AKT and MAP kinases activation to address the role of each event with respect to apoptosis. We demonstrate that serum/glucose depletion per se did not induce apoptosis when compared to ROS exposure. In particular, ROS recruited p38MAPK and JNK pathways. SB202190 preventing p38MAPK activity, partially protected HL‐5 from apoptosis while blocking JNK, thanks to JNKI, further enhanced apoptosis. Blocking phosphatidylinositol (PI) 3‐kinase with LY294002 or ERKs with U0126 was without consequence on apoptosis. Finally, BCL‐2 and BCL‐XL/S expression levels were analyzed in cells exposed to 1 h ischemia followed by 12‐h reperfusion in the presence or not of SB202190; BCL‐2, but not BCL‐XL/S, expression was decreased in ROS treated cells but SB202190 failed to restore BCL‐2 level. Our data suggest that p38MAPK activation primarily mediates ROS‐induced apoptosis while concomitant JNK activation would represent a scavenger pathway for cells trying to escape apoptosis. © 2003 Wiley‐Liss, Inc.
Control of hepatocyte DNA synthesis by intracellular pH and its role in the action of tumor promoters
Authors: Lee Chow H. , Cragoe Edward J. , Edwards Anthony M. 
Published: February 2003

AbstractThe mechanisms of tumor promotion in liver by various xenobiotics of diverse structure are not well understood. However, these tumor promoters share the ability to exert growth‐stimulatory effects on hepatocytes. Our laboratory has been utilizing normal rat hepatocytes under defined conditions of primary cultures, to investigate growth‐stimulatory actions of liver tumor promoters. We have shown that most, if not all, of the liver tumor promoters tested stimulate hepatocyte DNA synthesis when added in combination with epidermal growth factor (EGF), insulin, and glucocorticoids. In the present study, we sought evidence for the role of the Na+/H+ antiporter and cytoplasmic alkalinization in the direct growth‐stimulatory actions of tumor promoters on hepatocytes. Hepatocytes cultured under conditions (bicarbonate‐buffered medium) where intracellular pH (pHi) was independent of extracellular pH (pHe), EGF‐ and insulin‐stimulated rates of DNA synthesis were unaffected by modest changes in pHe. However, under conditions (HEPES‐buffered medium) where pHi varied in a linear fashion with pHe, rates of EGF‐ and insulin‐stimulated DNA synthesis were highly dependent on pHe. Similarly, 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) and α‐hexachlorocyclohexane (HCH)‐stimulated DNA synthesis were pHe‐dependent but were stimulatory over different pHe ranges, suggesting that these promoters may act by distinct mechanisms. Chemicals that are capable of inducing rapid cytoplasmic alkalinization, ammonium chloride (1 and 15 mM) and monensin (0.5 μM), were found to stimulate hepatocyte DNA synthesis. The role of the Na+/H+ antiport in controlling pHi of hepatocytes was demonstrated by artificially acidifying 2′,7′‐bis(carboxyethyl)‐5,6‐carboxyfluorescein acetoxymethyl (BCECF)‐loaded isolated hepatocytes with 20 mM sodium acetate and the use of specific inhibitors. Amiloride and its analogues inhibited pHi recovery from the acid load in a dose dependent manner and the relative potency of these inhibitors paralleled their Ki values for the Na+/H+ antiport. At concentrations that stimulate hepatocyte DNA synthesis, some liver tumor promoters phenobarbital (PB) and HCH, were found to cause a rapid rise pHi in isolated hepatocytes which was sensitive to amiloride and its analogues. Taken together, our data suggest that activation of Na+/H+ antiport activity may be one mechanism whereby some liver tumor promoters stimulate hepatocytes DNA synthesis. This study has implications for the mechanisms of tumor promotion in liver carcinogenesis. © 2003 Wiley‐Liss, Inc.
Cyclooxygenase and cytochrome P‐450 pathways induced by fetal calf serum regulate wound closure in 3T6 fibroblast cultures through the effect of prostaglandin E2 and 12 and 20 hydroxyeicosatetraenoic acids
Authors: Moreno Juan Jose 
Published: February 2003

AbstractWound‐induced injury of 3T6 fibroblast cultures initiated a repair process stimulated by fetal calf serum (FCS) that restored the integrity of cell cultures. In these experimental conditions, FCS induced arachidonic acid (AA) release and eicosanoid production. Our results show that the inhibition of the cyclooxygenase (COX) and/or cytochrome P‐450 pathways significantly decreases the wound closure, whereas that of the lipoxygenase pathway does not modify the wound repair process. Both EP1 and EP4 receptors of prostaglandin E2 (PGE2) mediate PGE2 stimulated 3T6 fibroblast wound closure. Our data suggest that calcium and cAMP are involved in the signaling event induced by PGE2 during the 3T6 fibroblast wound repair process. On the other hand, we show that ketoconazole, a cytochrome P‐450 inhibitor, hinders the wound closure induced by FCS in wounded 3T6 fibroblast cultures. 12 and 20 Hydroxyeicosatetraenoic acids (HETEs), which are key AA metabolites synthesized by cytochrome P‐450, partially revert the effects of ketoconazole on the wound repair process. Thus, the COX and cytochrome P‐450 pathways of the arachidonate cascade are involved in 3T6 fibroblast wound closure. © 2003 Wiley‐Liss, Inc.
Role of insulin‐like growth factor binding protein‐3 (IGFBP‐3) in the differentiation of primary human adult skeletal myoblasts
Authors: Foulstone Emily J. , Savage Paul B. , Crown Anna L. , Holly Jeff M.P. , Stewart Claire E.H. 
Published: February 2003

AbstractAlthough muscle satellite cells were identified almost 40 years ago, little is known about the induction of their proliferation and differentiation in response to physiological/pathological stimuli or to growth factors/cytokines. In order to investigate the role of the insulin‐like growth factor (IGF)/IGF binding protein (IGFBP) system in adult human myoblast differentiation we have developed a primary human skeletal muscle cell model. We show that under low serum media (LSM) differentiating conditions, the cells secrete IGF binding proteins‐2, ‐3, ‐4 and ‐5. Intact IGFBP‐5 was detected at days 1 and 2 but by day 7 in LSM it was removed by proteolysis. IGFBP‐4 levels were also decreased at day 7 in the presence of IGF‐I, potentially by proteolysis. In contrast, we observed that IGFBP‐3 initially decreased on transfer of cells into LSM but then increased with myotube formation. Treatment with 20 ng/ml tumour necrosis factor‐alpha (TNFα), which inhibits myoblast differentiation, blocked IGFBP‐3 production and secretion whereas 30 ng/ml IGF‐I, which stimulates myoblast differentiation, increased IGFBP‐3 secretion. The TNFα‐induced decrease in IGFBP‐3 production and inhibition of differentiation could not be rescued by addition of IGF‐I. LongR3IGF‐I, which does not bind to the IGFBPs, had a similar effect on differentiation and IGFBP‐3 secretion as IGF‐I, both with and without TNFα, confirming that increased IGFBP‐3 is not purely due to increased stability conferred by binding to IGF‐I. Furthermore reduction of IGFBP‐3 secretion using antisense oligonucleotides led to an inhibition of differentiation. Taken together these data indicate that IGFBP‐3 supports myoblast differentiation. © 2003 Wiley‐Liss, Inc.
Lamellipodial motility in wounded endothelial cells exposed to physiologic flow is associated with different patterns of β1‐integrin and vinculin localization
Authors: Albuquerque Maria Luiza C. , Flozak Annette S. 
Published: February 2003

AbstractIntegrins‐ and cytoskeletal‐associated focal adhesion proteins may participate in the process of endothelial wound closure, but their relationship in these wounds and in the presence of shear forces has not been defined. The goal in this study was to test the hypotheses that (1) modulation of β1‐integrin in human coronary artery endothelial cells (HCAEC) would alter endothelial wound closure under shear stress, and (2) β1‐integrin association with vinculin would be necessary for mediating this closure. HCAEC monolayers were pre‐conditioned to attain alignment by shearing at 12 dynes/cm2 for 18 h in a parallel‐plate flow chamber. Subsequently, they were divided into three groups: (a) control, (b) treated with anti‐β1‐integrin adhesion blocking antibody, or (c) treated with anti‐β1‐integrin adhesion promoting antibody. Next, the monolayers were wounded with a metal spatula, and re‐sheared at 20 dynes/cm2 or left static. Time‐lapse imaging and deconvolution microscopy were then performed for 3 h. Immunocytochemistry for β1‐integrin expression and vinculin was performed on all wounded monolayers. Under shear stress, vinculin localized to the ends of stress fibers, while β1‐integrin took on an intracellular macroaggregate appearance. Treatment with anti‐β1‐integrin adhesion blocking antibody enhanced wound closure, left the vinculin staining at the lamellipodial tips unchanged, but was associated with β1‐integrin staining at the lateral cell edges. Treatment with the anti‐β1‐integrin adhesion promoting antibody retarded wound closure, increased vinculin staining at cell‐cell junctions, and was associated with a fibrillar pattern of β1‐integrin staining. Modulation of β1‐integrin and changes in β1‐integrin and vinculin localization may further our understanding of laminar shear stress‐induced endothelial repair in the coronary circulation. © 2003 Wiley‐Liss, Inc.
CD31 (PECAM‐1)‐bright cells derived from AC133‐positive cells in human peripheral blood as endothelial‐precursor cells
Authors: Kanayasu‐Toyoda Toshie , Yamaguchi Teruhide , Oshizawa Tadashi , Hayakawa Takao 
Published: February 2003

AbstractTo clarify the process of endothelial differentiation, we isolated AC133+ cells and induced the in vitro differentiation of these cells into endothelial cells. AC133+ cells efficiently differentiated into endothelial cells when the cells were cultured on fibronectin‐coated dishes in the presence of vascular endothelial growth factor. Time‐course analysis of the alteration of endothelial markers on cultured AC133+ cells revealed that the expression of CD31 (PECAM‐1) on AC133+ cells was the earliest marker among all of the tested markers. Based on the hypothesis that CD31 is an early indicator during the endothelial differentiation, we examined the relationship between CD31 expression and the ability to differentiate into endothelial cells in cells derived from AC133+ cells. CD31‐bright cells, which were sorted from cultured AC133+ cells, differentiated more efficiently into endothelial cells than had CD31‐positive or CD31‐negative cells, suggesting that CD31‐bright cells may be precursor cells for endothelial cells. In the present study, we identified CD31+ cells derived from cultured AC133+ cells that are able to differentiate to endothelial cells as precursor cells. © 2003 Wiley‐Liss, Inc.
Epidermal growth factor induces an increase in cell adhesion and an arrangement of actin skeleton in stress fibres in pituitary cultured cells from infantile rats but not adult rats
Authors: Toral Claudia , Solano‐Agama M. Carmen , Luna José , Romano Marta C. , Mendoza‐Garrido M. Eugenia 
Published: February 2003

AbstractThe rat anterior pituitary gland undergoes changes in its cyto‐architecture during the second and third weeks of postnatal life. However, little is known about the factors that regulate these tissue conformational changes. The epidermal growth factor (EGF) is one of the growth factors that are synthesized by the pituitary gland, and almost all of the pituitary cells have EGF receptors (EGFR). In addition to the effects of the EGF on mitosis and differentiation, this growth factor can modulate cell adhesion, cell migration, and cytoskeletal organization. In this study we focussed our attention in examining the effects of EGF on the adhesion of cells to the extracellular matrix and on the actin cytoskeletal arrangement of pituitary cells from infantile and adult rats. Our results show that in infantile cells the EGF induces cell adhesion with increase in cell surface area. The arrangement of actin‐F in infantile EGF‐treated cells was in stress fibers and vinculin acquired a striped shape at the membrane border, suggesting the assembly of focal adhesion contacts. In contrast, in adult pituitary cells EGF does not induce any change in cell adhesion, and the cells maintain a rounded shape with an arrangement of actin‐F in thin cortical bands even though, immuno‐localization of the EGFR was observed in adult cells cultured in defined medium. We also looked for the EGFR in membrane preparations from infantile and adult pituitaries, and a marked difference in membrane EGFR was observed between them, the infantile pituitaries showing a significantly higher amount. Our results suggest that in infantile cells EGF induces the assembly of focal adhesion contacts, and that in adult cells the receptor of this growth factor is uncoupled of the signaling pathway by which a rearrangement of actin cytoskeleton occurs. © 2003 Wiley‐Liss, Inc.
Vanadium‐induced apoptosis and pulmonary inflammation in mice: Role of reactive oxygen species
Authors: Wang Liying , Medan Djordje , Mercer Robert , Overmiller Dean , Leornard Stephen , Castranova Vincent , Shi Xianglin , Ding Min , Huang Chuanshu , Rojanasakul Yon 
Published: February 2003

AbstractPulmonary exposure to metals and metal‐containing compounds is associated with pulmonary inflammation, cell death, and tissue injury. The present study uses a mouse model to investigate vanadium‐induced apoptosis and lung inflammation, and the role of reactive oxygen species (ROS) in this process. Aspiration of the pentavalent form of vanadium, V (V), caused a rapid influx of polymorphonuclear leukocytes into the pulmonary airspace with a peak inflammatory response at 6 h post‐exposure and resolution by 72 h. During this period, the number of apoptotic lung cells which were predominantly neutrophils increased considerably with a peak response at 24 h accompanied by no or minimum necrosis. After 24 h when the V (V)‐induced inflammation was in the resolution phase, an increased influx of macrophages and engulfment of apoptotic bodies by these phagocytes was observed, supporting the role of macrophages in apoptotic cell clearance and resolution of V (V)‐induced lung inflammation. Electron spin resonance (ESR) studies using lavaged alveolar macrophages showed the formation of ROS, including O2·−, H2O2, and ·OH radicals which were confirmed by inhibition with free radical scavengers. The mechanism of ROS generation induced by V (V) involved the activation of an NADPH oxidase complex and the mitochondrial electron transport chain. The ROS scavenger, catalase (H2O2 scavenger), effectively inhibited both lung cell apoptosis and the inflammatory response, whereas superoxide dismutase (SOD) (O2·− scavenger) and the metal chelator, deferoxamine (inhibitor of ·OH generation by Fenton‐like reactions) had lesser effects. These results indicate that multiple oxidative species are involved in V (V)‐induced lung inflammation and apoptosis, and that H2O2 plays a major role in this process. Published 2003 Wiley‐Liss, Inc.