bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sugar–Poly(para‐phenylene ethynylene) Conjugates as Sensory Materials: Efficient Quenching by Hg2+ and Pb2+ Ions
Authors: Kim Ik‐Bum , Erdogan Belma , Wilson James N. , Bunz Uwe H. F. 
Published: November 2004

AbstractThree polar poly(para‐phenylene ethynylene)s (PPE) were synthesized by utilizing the Heck–Sonogashira protocol. Two of the PPEs carry β‐glucopyranose substituents. Depending upon the linker used between the glycol units and the backbone, the fluorescence of these PPEs can be quenched by Hg2+ and Pb2+ to a varying degree. Monomeric model compounds that are substituted with only one glucose unit are not efficiently quenched. The presence of many glucose substituents in one PPE assembly led to a large increase in the binding constant to Hg2+ and quenching of the fluorescence was amplified.
Distant echoes of the accordion: Reduced dimensionality, GFT‐NMR, and projection‐reconstruction of multidimensional spectra
Authors: Freeman Ray , Kupče Eriks 
Published: November 2004

AbstractMultidimensional NMR spectroscopy can be speeded up appreciably by techniques that reduce the number of evolution periods examined independently. This review charts the evolution of the “reduced dimensionality” concept starting with the accordion experiment, and showing how it gradually developed into GFT‐NMR and projection‐reconstruction (PR‐NMR), which collects plane projections at different orientations and uses them to reconstruct the full multidimensional spectrum. While the data‐gathering stages of GFT‐NMR and PR‐NMR are similar, the processing stages are radically different. The methods described here are generally applicable to the standard multidimensional NMR sequences, and they offer comparable sensitivity and resolution, and a similar advantage in speed. By adopting a method related to the inverse Radon transform, PR‐NMR can also be applied to situations of only marginal sensitivity. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson 23A: 63–75, 2004.
NMR studies of surfactants
Authors: Söderman Olle , Stilbs Peter , Price William S. 
Published: November 2004

AbstractSurfactant molecules are amphipathic and posses complicated solution chemistry and self‐assembly properties. In addition to being of enormous practical significance, the physical characterization of surfactant systems presents a rich area of condensed matter physics. This article focuses on the application and interpretation of the commonly used NMR approaches for probing these systems. In particular, the use of NMR relaxation, diffusometry and, more briefly, electrophoretic NMR to determine characteristics such as micellar size and structure, ion‐binding and solubilization are considered. The application of these NMR techniques is illustrated by a number of pertinent examples. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson 23A:, 121–135, 2004.
NMR methods for studying membrane‐active antimicrobial peptides
Authors: Strandberg Erik , Ulrich Anne S. 
Published: November 2004

AbstractNMR is a versatile tool for studying interactions between antimicrobial peptides and lipid membranes. Different approaches using both liquid state and solid state NMR are outlined here, with an emphasis on solid state NMR methods, to study the structures of antimicrobial peptides in lipid bilayers as well as the effect of these peptides on model membranes. Different NMR techniques for observing both peptides and lipids are explained, including 2H, 13C, 15N, and 19F labels, or natural abundance 1H, 13C, or 31P. Previous studies in the field are extensively reviewed in easily accessible tables. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson 23A: 89–120, 2004.
Human ovarian carcinoma cells: Histone deacetylase inhibitors exhibit antiproliferative activity and potently induce apoptosis
Authors: Takai Noriyuki , Kawamata Norihiko , Gui Dorina , Said Jonathan W. , Miyakawa Isao , Koeffler H. Phillip 
Published: November 2004

AbstractBACKGROUNDHistone deacetylase inhibitors (HDACIs) can inhibit proliferation, stimulate apoptosis, and induce cell cycle arrest in malignant cells.METHODSThe authors investigated the effects of four HDACIs on nine ovarian carcinoma cell lines in vitro and in vivo. Ovarian carcinoma cells were treated with a variety of HDACIs, and their effects on cell growth, the cell cycle, apoptosis, and related events were investigated. The ability of valproic acid (VPA) to inhibit the growth of ovarian tumors in immunodeficient mice was also assessed.RESULTSClonogenic assays showed that all ovarian carcinoma cell lines were sensitive to the growth‐inhibitory effects of the HDACIs. Cell cycle analysis indicated that their exposure to HDACIs decreased the proportion of cells in S phase and increased the proportion of cells in the G0/G1 and/or G2/M phases of the cell cycle. Terminal deoxynucleotidyltransferase‐mediated uridine triphosphate end‐labeling assays demonstrated that HDACIs induced apoptosis, which occurred in concert with alterations in the expression of genes related to apoptosis, cell growth, and malignant phenotype, including the activation of caspase‐9 and caspase‐3. Chromatin immunoprecipitation analysis revealed a notable increase in levels of acetylated histones associated with the p21 promoter after treatment with suberoylanilide bishydroxamine. In addition, in experiments involving nude mice, VPA significantly inhibited human ovarian tumor growth without toxic side effects.CONCLUSIONSThe results of the current study suggest that HDACIs may be particularly effective in the treatment of ovarian tumors. Cancer 2004. © 2004 American Cancer Society.
Rhabdomyosarcoma: Value of myogenin expression analysis and molecular testing in diagnosing the alveolar subtype
Authors: Hostein Isabelle , Andraud‐Fregeville Marie , Guillou Louis , Terrier‐Lacombe Marie‐José , Deminière Colette , Ranchère Dominique , Lussan Catherine , Longavenne Elisabeth , Bui Nguyen Binh , Delattre Olivier , Coindre Jean‐Michel 
Published: November 2004

AbstractBACKGROUNDIdentification of the alveolar subtype of rhabdomyosarcoma (ARMS) is important, because the poor prognosis associated with this subtype necessitates a modified therapeutic regimen. At present, ARMS diagnoses are made on the basis of histologic findings and the extent of myogenin immunopositivity. Nonetheless, the absence of an alveolar pattern in the solid variant, the low degree of differentiation in certain embryonal rhabdomyosarcomas (ERMS), and the increasing use of microbiopsy samples make the diagnosis of ARMS somewhat difficult. Two specific translocations have been found in ARMS, and fusion transcripts can be detected by reverse transcriptase–polymerase chain reaction (RT‐PCR) analysis of paraffin‐embedded tissue (PET).METHODSTo assess the value of myogenin staining and molecular testing in the diagnosis of rhabdomyosarcoma, the authors examined 109 rhabdomyosarcoma samples (45 ARMS samples and 64 ERMS samples). Real‐time RT‐PCR analysis of PET was performed in all 109 rhabdomyosarcomas, and RT‐PCR analysis of frozen material was performed in 24 cases.RESULTSPAX fusion transcripts were present in 44 cases (39 ARMS and 5 ERMS) and absent in 52 cases (2 ARMS and 50 ERMS). In 13 cases (4 ARMS and 9 ERMS), the results were not interpretable. Results were concordant between paired frozen and fixed tumor samples. All 35 interpretable ERMS samples that contained < 50% myogenin‐positive cells failed to yield detectable PAX fusion transcripts. Of the 61 interpretable tumor samples (41 ARMS and 20 ERMS) that contained > 50% myogenin‐positive cells, 44 (39 ARMS and 5 ERMS) yielded detectable PAX fusion transcripts.CONCLUSIONSThe current study demonstrates that molecular detection of PAX fusion transcripts via real‐time RT‐PCR analysis of PET is a sensitive and specific method for the diagnosis of ARMS and that immunohistochemical analysis of myogenin expression can be used to select cases for such molecular testing. Although RT‐PCR analysis appears not to possess diagnostic value in tumors with < 50% tumor cell immunopositivity, it is strongly recommended for the diagnosis of tumors containing > 50% myogenin‐positive cells. Cancer 2004. © 2004 American Cancer Society.
Quantitative analysis by flow cytometry of interstitial cells of Cajal, pacemakers, and mediators of neurotransmission in the gastrointestinal tract
Authors: Ördög Tamás , Redelman Doug , Horváth Viktor J. , Miller Lisa J. , Horowitz Burton , Sanders Kenton M. 
Published: November 2004

AbstractBackgroundInterstitial cells of Cajal (ICCs) are mesenchymal cells that play critical roles in gastrointestinal motility as electrical pacemakers and mediators of neuromuscular neurotransmission. Although depletions of ICCs have been implicated in several gastrointestinal motor disorders, quantification of these cells has been difficult due to their varied morphology, regionally changing network density, and overall scarcity. Our goal was to evaluate flow cytometry (FCM) for the enumeration of ICCs.MethodsWe identified murine ICCs in live gastrointestinal muscles or primary cell cultures grown in the presence or absence of stem cell factor (SCF)–expressing STO fibroblasts with fluorescent Kit (CD117) antibodies. Because this technique also labels resident macrophages nonspecifically, we identified the latter with additional fluorescent antibodies. Dispersed cells were analyzed by FCM.ResultsICCs represented 1.63 ± 0.17% of the total cell count in the distal stomach (n = 18 mice) and 5.85 ± 0.84% in the proximal colon and 6.28 ± 0.61% in the distal colon (n = 3 mice). In fundic muscles of W/WV mice (n = 5) that virtually lack ICCs, very few Kit+ cells were detected. FCM identified approximately 2.6‐ to 7.3‐fold more Kit+ ICCs in small intestinal cell cultures grown on STO fibroblasts expressing membrane‐bound SCF (n = 6) than in cultures stimulated with soluble SCF (n = 6).ConclusionsFCM is a sensitive and specific method for the unbiased quantification of ICCs. © 2004 Wiley‐Liss, Inc.
Lectin‐based three‐color flow cytometric approach for studying cell surface glycosylation changes that occur during apoptosis
Authors: Batisse Chantal , Marquet Jeanine , Greffard Anne , Fleury‐Feith Jocelyne , Jaurand Marie‐Claude , Pilatte Yannick 
Published: November 2004

AbstractBackgroundChanges in cell surface glycosylation that accompany apoptosis are thought to be involved in the recognition and removal of apoptotic cells by phagocytes, but in most instances these changes are ill defined. To improve our understanding of this phenomenon, we designed a trivariate flow cytometry procedure that allows direct comparison of cell surface glycosylation in apoptotic and viable cellsMethodsThe annexin V/propidium iodide assay has been adapted for cell surface glycosylation analysis by combining the use of these two reagents with biotinylated lectins, and this has been used to investigate camptothecin‐induced apoptosis in U‐937 cells.ResultsAlthough numerous lectins are potent inducers of apoptosis, we found that it is possible to determine lectin concentrations that produce interpretable data without inducing significant cytotoxicity even when using apoptogenic lectins. That apoptosis is associated with a marked decrease in cell surface sialylation was confirmed by using the sialic acid–specific lectins Maackia amurensis agglutinin and Sambucus nigra agglutinin. These observations were corroborated by lectin blotting analysis with the same lectins.ConclusionsSpecies‐ and cell‐dependent altered glycosylation patterns are likely to be associated with different modes of apoptosis. The easy and versatile method described in this report should be useful for exploring this field. © 2004 Wiley‐Liss, Inc.
Turbulence model and numerical scheme assessment for buffet computations
Authors: Goncalves Eric , Houdeville Robert 
Published: November 2004

AbstractThe prediction of shock‐induced oscillations over transonic rigid airfoils is important for a better understanding of the buffeting phenomenon. The unsteady resolution of the Navier–Stokes equations is performed with various transport‐equation turbulence models in which corrections are added for non‐equilibrium flows. The lack of numerical efficiency due to the CFL stability condition is circumvented by the use of a wall law approach and a dual time stepping method. Moreover, various numerical schemes are used to try and be independent of the numerical discretization.Comparisons are made with the experimental results obtained for the supercritical RA16SC1 airfoil. They show the interest in using the SST correction or realizability conditions to get correct predictions of the frequency, amplitude and pressure fluctuations over the airfoil. Copyright © 2004 John Wiley & Sons, Ltd.
Reversed operation of glutamate transporter GLT‐1 is crucial to the development of preconditioning‐induced ischemic tolerance of neurons in neuron/astrocyte co‐cultures
Authors: Kawahara Koichi , Kosugi Tatsuro , Tanaka Motoki , Nakajima Takayuki , Yamada Takeshi 
Published: November 2004

AbstractSublethal ischemia leads to increased tolerance against subsequent prolonged cerebral ischemia in vivo. In the present study, we investigated the roles of the astrocytic glutamate (Glu) transporter GLT‐1 in preconditioning (PC)‐induced neuronal ischemic tolerance in cortical neuron/astrocyte co‐cultures. Ischemia in vitro was simulated by subjecting cultures to both oxygen and glucose deprivation (OGD). A sublethal OGD (PC) increased the survival rate of neurons significantly when cultures were exposed to a lethal OGD 24 h later. The extracellular concentration of Glu increased significantly during PC, and treatment with an inhibitor of N‐methyl‐D‐actetate (NMDA) receptors significantly reversed the PC‐induced ischemic tolerance of neurons, suggesting that the increase in extracellular concentration of Glu during PC was critical to the development of PC‐induced neuronal ischemic tolerance via the activation of NMDA receptors. Treatment with a GLT‐1 blocker during PC suppressed this increase in Glu significantly, and antagonized the PC‐induced neuronal ischemic tolerance. This study suggested that the reversed operation of GLT‐1 was crucial to the development of neuronal ischemic tolerance. © 2004 Wiley‐Liss, Inc.
Differential activation of astrocytes by innate and adaptive immune stimuli
Authors: Carpentier Pamela A. , Begolka Wendy Smith , Olson Julie K. , Elhofy Adam , Karpus William J. , Miller Stephen D. 
Published: November 2004

AbstractThe immunologic privilege of the central nervous system (CNS) makes it crucial that CNS resident cells be capable of responding rapidly to infection. Astrocytes have been reported to express Toll‐like receptors (TLRs), hallmark pattern recognition receptors of the innate immune system, and respond to their ligation with cytokine production. Astrocytes have also been reported to respond to cytokines of the adaptive immune system with the induction of antigen presentation functions. Here we have compared the ability of TLR stimuli and the adaptive immune cytokines interferon‐γ (IFN‐γ) and tumor necrosis factor‐α (TNF‐α) to induce a variety of immunologic functions of astrocytes. We show that innate signals LPS– and poly I:C lead to stronger upregulation of TLRs and production of the cytokines IL‐6 and TNF‐α as well as innate immune effector molecules IFN‐α4, IFN‐β, and iNOS compared with cytokine‐stimulated astrocytes. Both innate stimulation and adaptive stimulation induce similar expression of the chemokines CCL2, CCL3, and CCL5, as well as similar enhancement of adhesion molecule ICAM‐1 and VCAM‐1 expression by astrocytes. Stimulation with adaptive immune cytokines, however, was unique in its ability to induce upregulation of MHC II and the functional ability of astrocytes to activate CD4+ T cells. These results indicate potentially important and changing roles for astrocytes during the progression of CNS infection. © 2004 Wiley‐Liss, Inc.
Mannose receptor expression specifically reveals perivascular macrophages in normal, injured, and diseased mouse brain
Authors: Galea Ian , Palin Karine , Newman Tracey A. , Van Rooijen Nico , Perry V. Hugh , Boche Delphine 
Published: November 2004

AbstractPerivascular macrophages are believed to have a significant role in inflammation in the central nervous system (CNS). They express a number of different receptors that point toward functions in both innate immunity, through pathogen‐associated molecular pattern recognition, phagocytosis, and cytokine responsiveness, and acquired immunity, through antigen presentation and co‐stimulation. We are interested in the receptors that are differentially expressed by perivascular macrophages and microglia in both the normal CNS as well as in neuroinflammation and neurodegeneration. In this article we report the use of a well‐characterized monoclonal antibody, 5D3, to localize the expression of the mannose receptor to perivascular macrophages in the normal CNS and in various models of brain pathology. Mannose receptor expression was limited to perivascular, meningeal, and choroid plexus macrophages in normal, inflamed, injured, and diseased CNS. In particular, activated microglia and invading hematogenous leukocytes were mannose receptor negative while expressing the F4/80 antigen, macrosialin (CD68), FcRII (CD32), scavenger receptor (CD204), and CR3 (CD11b/CD18). Since the perivascular macrophages expressing the mannose receptor are known to be the only constitutively phagocytic cells in the normal CNS, we injected clodronate‐loaded liposomes intracerebroventricularly in control mice to deplete these cells. In these mice, there was no detectable mannose receptor expression in perivascular spaces after immunocytochemistry with the 5D3 monoclonal antibody. This finding underlines the value of the monoclonal antibody 5D3 as a tool to study murine perivascular macrophages selectively. Mannose receptor expression by macrophages located at blood‐brain (perivascular), brain‐cerebrospinal fluid (CSF) (meningeal), and CSF‐blood (choroid plexus) interfaces supports a functional role of these cells in responding to external stimuli such as infection. © 2004 Wiley‐Liss, Inc.
Human embryonic stem cells differentiate into oligodendrocytes in high purity and myelinate after spinal cord transplantation
Authors: Nistor Gabriel I. , Totoiu Minodora O. , Haque Nadia , Carpenter Melissa K. , Keirstead Hans S. 
Published: November 2004

AbstractHuman embryonic stem cells (hESCs) demonstrate remarkable proliferative and developmental capacity. Clinical interest arises from their ability to provide an apparently unlimited cell supply for transplantation, and from the hope that they can be directed to desirable phenotypes in high purity. Here we present for the first time a method for obtaining oligodendrocytes and their progenitors in high yield from hESCs. We expanded hESCs, promoted their differentiation into oligodendroglial progenitors, amplified those progenitors, and then promoted oligodendroglial differentiation using positive selection and mechanical enrichment. Transplantation into the shiverer model of dysmyelination resulted in integration, differentiation into oligodendrocytes, and compact myelin formation, demonstrating that these cells display a functional phenotype. This differentiation protocol provides a means of generating human oligodendroglial lineage cells in high purity, for use in studies of lineage development, screening assays of oligodendroglial‐specific compounds, and treating neurodegenerative diseases and traumatic injuries to the adult CNS. © 2004 Wiley‐Liss, Inc.
Glial transcytosis of a photoreceptor‐secreted signaling protein, retinoschisin
Authors: Reid Silvia N.M. , Farber Debora B. 
Published: November 2004

AbstractIn vitro studies have clearly shown that signaling/guidance proteins can diffuse to their targets. However, it is unclear whether they can travel by diffusion in vivo, or if they are distributed in the tissue by an active mechanism. Retinoschisin, a signaling molecule related to neuropilins, is synthesized and secreted by photoreceptor cells in the outer retina; then it interacts with inner retinal cells contributing to synaptic organization and optic nerve fiber integrity. We developed an assay to examine how retinoschisin, which is secreted a distance away, reaches its inner retinal targets. We found that retinoschisin is preferentially taken up and carried into the inner retina from the retinal outer border (the photoreceptor side) by Müller cells (the main glial cells of the vertebrate retina). This transcytosis is disrupted by DL‐α‐aminoadipic acid, a Müller cell/glia‐specific toxin. Our results suggest that glial uptake/transcytosis can provide an effective and precise alternative for distributing signaling molecules in the nervous system. © 2004 Wiley‐Liss, Inc.
Evaluation of cytocompatibility and bending modulus of nanoceramic/polymer composites
Authors: McManus Anastasia J. , Doremus Robert H. , Siegel Richard W. , Bizios Rena 
Published: November 2004

AbstractIn an attempt to simulate the microstructure and mechanical properties of natural bone, novel nanoceramic/polymer composite formulations were fabricated and characterized with respect to their cytocompatibility and mechanical properties. The bending moduli of nanocomposite samples of either poly(L‐lactic acid) (PLA) or poly(methyl methacrylate) (PMMA) with 30, 40, and 50 wt % of nanophase (<100 nm) alumina, hydroxyapatite, or titania loadings were significantly (p < 0.05) greater than those of pertinent composite formulations with conventional, coarser grained ceramics. The nanocomposite bending moduli were 1–2 orders of magnitude larger than those of the homogeneous, respective polymer. For example, compared with 0.06 GPa for the 100% PLA, the bending modulus of 50/50 nanophase alumina/PLA composites was 3.5 GPa. Osteoblast adhesion on the surfaces of the nanophase alumina/PLA composites increased as a function of the nanophase ceramic content. Most importantly, osteoblast adhesion on the 50/50 nanophase alumina/PLA substrates was similar to that observed on the 100% nanophase ceramic substrates. Similar trends of osteoblast adhesion were observed on the surfaces of the nanophase titania/polymer and nanophase hydroxyapaptite/polymer composites that were tested. In contrast, fibroblast adhesion on the nanophase composites was either similar or lower than that observed on the conventional composites with either PLA or PMMA and minimum on all tested neat nanophase substrates. The calcium content in the extracellular matrix of cultured osteoblasts was also enhanced on the nanoceramic/PLA composite substrates tested as a function of the nanophase ceramic loading and duration of cell culture. The results of the present in vitro study provide evidence that nanoceramic/polymer composite formulations are promising alternatives to conventional materials because they can potentially be designed to match the chemical, structural, and mechanical properties of bone tissue in order to overcome the limitations of the biomaterials currently used as bone prostheses. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 98–106, 2005