bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel apoptosis assay to analyze immunosuppression
Authors: Boldt Andreas , Barten Markus Johannes , Weiss Claudia , Sagner Anja , Mohr Friedrich Wilhelm , Gummert Jan Fritz 
Published: February 2006

AbstractBackgroundWe developed a novel whole blood assay to assess the effects of immunosuppressants on lymphocyte apoptosis.MethodsPeripheral blood for six experiments for each drug was treated either with cyclosporin A (CsA), mycophenolate acid (MPA), tacrolimus (TRL) or rapamycin (RAPA). Whole blood was stimulated with different concentrations of staurosporine (0–5 μM) for 24 h. Using FACS, apoptosis were measured by Annexin V expression (%cells ± SEM).ResultsMPA, RAPA, TRL, but not CsA, increased (P < 0.05) apoptotic cells (MPA:20.9 ± 3.7; RAPA:17.5 ± 3.3; TRL:16.4 ± 2.9 vs. control:15.2 ± 2.8).ConclusionThis new whole blood assay exhibited that MPA has a stronger effect on apoptosis than RAPA and TRL, whereas CsA had no effect. © 2006 International Society for Analytical Cytology
Flow cytometric analysis of the in situ hybridization of cyclooxygenase isoforms in mesangial cells treated with cyclosporine A
Authors: de Hornedo J. Pérez , Fernández M. Calvino , de la Fuente G. de Arriba , Fernández P. del Reino , Cid T. Parra , Martinez S. Benito 
Published: February 2006

AbstractBackgroundCyclosporine A increases oxidative stress in kidney and we hypothesized that cyclooxygenase (COX) may be involved in this effect.Material and MethodsMesangial cells of Cyclosporine A‐treated (4, 7 or 10 days) rats were obtained to evaluate mRNA expression of COX‐isoforms (COX‐1, constitutive and COX‐2, inducible) by “in situ” hybridization. Probes were labelled using “Gene Image Random Prime Labelling Protocol” and COX expression was measured by flow cytometry.Results and Discussion“In situ” hybridization by flow cytometry is an useful method to detect mRNA. We observed an increased COX‐2 expression in a time‐dependent manner in parallel with Reactive Oxygen Species synthesis. COX‐1 expression increased only at 10 days. © 2006 International Society for Analytical Cytology
Microfluorometry of cell membrane dynamics
Authors: Weber Petra , Wagner Michael , Schneckenburger Herbert 
Published: February 2006

AbstractMembranes of living cells are characterized by a combination of conventional and total internal reflection fluorescence microscopy (TIRFM) using the membrane marker laurdan. In the first case, all cellular membranes are assessed simultaneously, whereas in the second case, the plasma membrane is excited selectively by the evanescent electromagnetic field of a laser beam. A spectral shift depending on the phase of membrane lipids is used to characterize membrane stiffness, which decreases with temperature and increases with the amount of cholesterol. Spectral properties are evaluated and displayed as microscopic images. © 2006 International Society for Analytical Cytology
Function of indoleamine 2,3‐dioxygenase in corneal allograft rejection and prolongation of allograft survival by over‐expression
Authors: Beutelspacher Sven C. , Pillai Radhakrishna , Watson Martin P. , Tan Peng H. , Tsang Julia , McClure Myra O. , George Andrew J. T. , Larkin Daniel F. P. 
Published: February 2006

AbstractIndoleamine 2,3‐dioxygenase (IDO) suppresses T cell responses by its action in catabolising tryptophan. It is important in maintenance of immune privilege in the placenta. We investigated the activity of IDO in the cornea, following corneal transplantation and the effect of IDO over‐expression in donor corneal endothelium on the survival of corneal allografts. IDO expression was analysed and functional activity was quantified in normal murine cornea and in corneas following transplantation as allografts. Low levels of IDO, at both mRNA and protein levels, was detected in the normal cornea, up‐regulated by IFN‐γ and TNF. Expression of IDO in cornea was significantly increased following corneal transplantation. However, inhibition of IDO activity in vivo had no effect on graft survival. Following IDO cDNA transfer, murine corneal endothelial cells expressed functional IDO, which was effective at inhibiting allogeneic T cell proliferation. Over‐expression of IDO in donor corneal allografts resulted in prolonged graft survival. While, on one hand, our data indicate that IDO may augment corneal immune privilege, up‐regulated IDO activity following cytokine stimulation may serve to inhibit inflammatory cellular responses. While increasing IDO mRNA expression was found in allogeneic corneas at rejection, over‐expression in donor cornea was found to significantly extend survival of allografts.
A very rapid and simple assay based on trogocytosis to detect and measure specific T and B cell reactivity by flow cytometry
Authors: Puaux Anne‐Laure , Campanaud Julie , Salles Audrey , Préville Xavier , Timmerman Benedikt , Joly Etienne , Hudrisier Denis 
Published: February 2006

AbstractDetection, quantification, separation and characterization of T and B cells reactive to specific antigens are important tasks in both basic and clinical immunology. Here, we describe an approach allowing the performance of all four tasks on a functional basis by flow cytometry. The assay is based on the property of lymphocytes to capture membrane components from the cells they interact with, in a process we call trogocytosis. Working with CD8+ CTL and target cells labeled with membrane markers, we describe the conditions allowing reactive lymphocytes to be detected rapidly and inexpensively within mixed populations. Accordingly, we used this method to monitor the CTL response triggered in mice after vaccination. In addition, we documented the applicability of this method to the detection of antigen‐specific CD4+ T and B cells. While our method is, for the time being, not as sensitive as staining of CTL with MHC class I multimers, it allows the simultaneous quantitative identification of reactive CD8+, CD4+ and B cells. Altogether, our method offers a simple and general alternative to other methods previously described to detect and quantify lymphocyte reactivity, and it can also be used in combination with those.
Ikaros has a crucial role in regulation of B cell receptor signaling
Authors: Nera Kalle‐Pekka , Alinikula Jukka , Terho Perttu , Narvi Elli , Törnquist Kid , Kurosaki Tomohiro , Buerstedde Jean‐Marie , Lassila Olli 
Published: February 2006

AbstractThe transcription factor Ikaros, a key regulator of hematopoiesis, has an essential role in lymphocyte development. In mice, fetal lymphoid differentiation is blocked in the absence of Ikaros, and whereas T cells develop postnatally, B cells are totally absent. The significance of Ikaros in the B cell development is evident, but how Ikaros regulates B cell function has neither been established nor previously been studied with B cells that lack Ikaros expression. Here we show that disruption of Ikaros in the chicken B cell line DT40 induces a B cell receptor (BCR) signaling defect with reduced phospholipase Cγ2 phosphorylation and impaired intracellular calcium mobilization, which is restored by Ikaros reintroduction. Furthermore, we show that lack of Ikaros induces hyperphosphorylation of Casitas B lymphoma protein subsequent to BCR activation. These results indicate that the absolute need of Ikaros for development, cell fate decisions and maintenance of B cells is due to the enhancement of BCR signaling.
N–H···S Hydrogen Bonds in a New Family of Ion‐Pair Complexes Between Cationic Nickel Tetraazabicyclononane and Anionic Metal Dithiolates: Synthesis, Characterization and Properties of [Ni(C9H22N6)][M(mnt)2](MII = Cu, Ni, Pd)
Authors: Madhu Vedichi , Das Samar K. 
Published: February 2006

AbstractThe ion‐pair complexes [Ni(C9H22N6)][Cu(mnt)2] (1), [Ni(C9H22N6)][Ni(mnt)2] (2), and [Ni(C9H22N6)][Pd(mnt)2] (3; mnt2– = 1,2‐dicyanoethylenedithiolate, C9H22N6 = 3,7‐bis(2‐aminoethyl)‐1,3,5,7‐tetraazabicyclo[3.3.1]nonane) have been synthesized and characterized by elemental analysis, IR, UV/Vis, and 1H NMR spectroscopy, X‐ray powder diffraction, and electrochemical studies, and unambiguously by single‐crystal X‐ray crystallography. All three complexes are isostructural and crystallize in the monoclinic space groupP21/n. The N–H···S‐type hydrogen‐bonding capabilities of the classical sulfur‐containing complex anions [MII(mnt)2]2– (A; M = Cu, Ni and Pd) have been explored using amine groups containing the nickel complex cation [Ni(C9H22N6)]2+ (C) in the ion‐pair compounds 1, 2, and 3. In the crystal, the cation interacts with two different anions through three N–H···S hydrogen bonds and, likewise, the anion is hydrogen‐bonded to two different cations through three hydrogen bonds, resulting in the formation of a chain‐like arrangement. The average N–H···S hydrogen‐bond lengths are 3.498(3), 3.505(3), and 3.490(5) Å for compounds 1, 2, and 3, respectively. Another crystallographic feature is the presence of CC–AA–CC–AA‐type packing with short S···Ni contacts in the crystal structures. Besides crystallography, the existence of these N–H···S hydrogen bonds between cation [Ni(C9H22N6)]2+ (C) and anion [MII(mnt)2]2– (A) is strongly supported by the IR and 1H NMR studies. The stability of the [Ni(C9H22N6)]2+ (C) moiety in compounds 1, 2, and 3 is discussed in light of electrochemical studies performed on these compounds and [Ni(C9H22N6)](ClO4)2. Complex 1 exhibits a well‐resolved ESR signal corresponding to a Cu2+ (d9) system at liquid‐nitrogen temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
An Electron Microscopy Study of New Chemically Twinned Phases in the MgS‐Yb2S3 System
Authors: Urones‐Garrote Esteban , Gómez‐Herrero Adrián , Landa‐Cánovas Ángel R. , Otero‐Díaz L. Carlos 
Published: February 2006

AbstractFour new phases in the MgS‐Yb2S3 system have been identified and characterised by means of transmission electron microscopy and associated techniques, such as microdiffraction and X‐ray energy dispersive spectroscopy analysis. The observed stoichiometries are: MgYb2S4 [a = 0.3752(2), b = 1.259(1), c = 1.268(2) nm] and Mg2Yb6S11 [a = 0.37297(4), b = 1.2592(2), c = 3.4853(3) nm] with orthorhombic symmetry (space group Cmcm) and Mg3Yb8S15 [a = 1.2637(1), b = 0.37176(5), c = 2.4132(2) nm; β = 100.40(1)°] and MgYb4S7 [a = 1.2578(2), b = 0.3735(3), c = 1.1417(7) nm; β = 104.88(6)°] with monoclinic symmetry (space group C2/m). Their structures can be described and derived from the NaCl‐type by the crystallographic operation of chemical twinning at the unit‐cell level along the {113}NaCl planes. The a and b lattice parameters are common in all the structures while the cparameter depends on the total extension of the twin slabs’ sequence, n, such that c ≈ n × d(113)MgS (for orthorhombic phases) or d(001) ≈ n × d(113)MgS (for monoclinic phases). All the unit‐cell parameters were refined from the X‐ray powder diffraction data after the unit‐cell symmetries had been deduced from electron microscopy data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Peroxynitrite/Nitric Oxide Balance in Ischemia/Reperfusion Injury‐Nanomedical Approach
Authors: Kubant Ruslan , Malinski Christopher , Burewicz Andrzej , Malinski Tadeusz 
Published: February 2006

AbstractElectrochemical nanosensors were used to simultaneously monitor in vitro (a single endothelial cell) and in vivo (vasculature of rat) the concentrations of NO (vasorelaxant), cytotoxic O$\rm{ {_{2}^{-}}}$ (oxidative stress) and ONOO− (nitroxidative stress). A balance of [NO]/[ONOO−]=(K) was applied as the diagnostic marker of dysfunctional endothelium and cardiovascular disease. In the isolated endothelium of normotensive rats, K= 2.8±0.1 while in hypertensive rats, K=0.4±0.1. During ischemia, K dropped from 7±1 to 1.4±0.2 and further decreased to 0.05±0.01 during reperfusion. The edema and vasoconstriction, indicators of vascular injury, correlated directly with the decrease in K.
Astrocyte heterogeneity revealed by expression of a GFAP‐LacZ transgene
Authors: Lee Youngjin , Su Mu , Messing Albee , Brenner Michael 
Published: February 2006

AbstractGlial fibrillary acidic protein (GFAP) is an intermediate filament protein present primarily in astrocytes. The gene is first expressed as astrocytes mature, and in the adult is strongly upregulated in response to CNS damage. Thus, in addition to its astrocyte specificity, transcriptional regulation of the GFAP gene is of interest as a reporter of CNS signaling during development and injury. Several laboratories have shown that approximately 2 kb of 5′‐flanking DNA of the human or mouse GFAP gene is sufficient to direct transgene expression to astrocytes and to confer developmental and injury‐induced regulation. Enhancer regions have been identified adjacent to the basal promoter and about 1500 bp upstream of the RNA start site. Juxtaposition of these two segments yielded a 447 bp promoter, gfa28, which strongly drove reporter activity in transfected glioma cells. We report here that in mice a gfa28‐lacZ transgene expresses in only certain brain regions, revealing an unexpected heterogeneity among astrocytes. The restricted pattern of expression is present early in development, is not altered by injury, and is preserved in cultured astrocytes. However, astrocytes cultured from an inactive region strongly express a transiently transfected gfa28‐lacZ construct, and activity of the embedded gfa28‐lacZ transgene is partially restored by treatment with a histone deacetylase inhibitor. These results indicate that the absence of gfa28‐lacZ expression in specific brain regions results from a developmental failure to remodel GFAP chromatin to an open structure. Thus, expression of the gfa28‐lacZ transgene appears to serendipitously mark a distinct set of astrocyte precursors. © 2006 Wiley‐Liss, Inc.
Blockade of PD‐L1 (B7‐H1) augments human tumor‐specific T cell responses in vitro
Authors: Blank Christian , Kuball Juergen , Voelkl Simon , Wiendl Heinz , Becker Bernd , Walter Bernhard , Majdic Otto , Gajewski Thomas F. , Theobald Mathias , Andreesen Reinhard , Mackensen Andreas 
Published: February 2006

AbstractHuman tumors frequently escape immune destruction, despite the presence of cyototoxic T cells (CTL) recognizing tumor‐associated antigens (TAA). We have previously shown that programmed death ligand‐1 (PD‐L1), a recently identified ligand of the B7 superfamily, is expressed on murine tumors and can inhibit antitumor immune responses. To evaluate the clinical relevance of our animal model findings, we examined human tumors and tumor‐specific T cells. We found PD‐L1 to be constitutively expressed on human renal cell carcinoma (RCC) cell lines and upregulated on human melanoma cell lines upon exposure to interferon‐gamma. Similarly, we found binding of anti‐PD‐L1 monoclonal antibody (mAb) on frozen sections from RCC and melanomas, but not on normal tissues. The corresponding inhibitory receptor of PD‐L1, PD‐1, revealed a higher expression on tumor‐infiltrating lymphocytes than on peripheral blood lymphocytes (PBL) from melanoma patients upon specific antigen stimulation. Stimulation of PBL from healthy donors with peptide‐loaded dendritic cells in the presence of anti‐PD‐L1 mAb altered neither the total T cell numbers after expansion, nor the percentage of peptide‐specific CTL, when providing a T cell help by addition of cytokines. However, when stimulating TAA‐specific CTL and T helper cells with Ag‐pulsed dendritic cells in the absence of exogenous cytokines, PD‐L1 blockade increased the cytokine production. Similar to the data achieved in the murine system, the blockade of PD‐L1 on human tumors resulted in enhanced cytolytic activity of TAA‐specific CTLs and cytokine production of TAA‐specific T helper cells when interacting directly with the tumor. In summary, our data suggest that PD‐L1/PD‐1 interactions negatively regulate T cell effector functions predominately in the absence of exogenous cytokine support, indicating an important role for this pathway in tumor evasion. © 2006 Wiley‐Liss, Inc.
Picophytoplankton contribution to phytoplankton community structure in the Gulf of Venice (NW Adriatic Sea)
Authors: Aubry Fabrizio Bernardi , Acri Francesco , Bastianini Mauro , Pugnetti Alessandra , Socal Giorgio 
Published: February 2006

AbstractThe size distribution of the phytoplankton community has been analyzed on a monthly basis in the Gulf of Venice (NW Adriatic Sea), with the aim to assess the seasonal variation of the contribution of autotrophic picoplankton (APP) to total phytoplankton. The investigation was carried out in two stations characterized by different influences of fluvial inputs. APP was mainly made up of Synechococcus , the larger fraction (Utermöhl Fraction Phytoplankton, UFP: µm as maximum linear dimension) of diatoms and nanoflagellates. The average APP abundance (46 × 103 cells ml–1) and biomass (8.1 µg C dm–3) indicate that APP was a persistent and significant component of the NW Adriatic phytoplankton. The highest APP abundance (up to 270 × 103 cells ml–1) and biomass (up to 49 µg C dm–3) were recorded from summer to autumn, UFP peaked from late winter to late spring. The mean APP contribution to total phytoplankton abundance and biomass was 98% and 31% respectively.The seasonal variation of total phytoplankton biomass was mainly driven by the UFP fraction; however, a seasonal shift in the relative importance of UFP and APP occurred from spring to summer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Regulation of Rotifer Community by Predation of Cyclops vicinus (Copepoda) in the Římov Reservoir in Spring
Authors: Devetter Miloslav , Seďa Jaromír 
Published: February 2006

AbstractThe structuring role and predation impact of Cyclops vicinus on the rotifer community was studied using in situ enclosure experiments in Římov Reservoir during the spring of 2000. Seasonal changes in abundance and birth rates of the rotifer species Synchaeta lakowitziana , Polyarthra spp., Keratella cochlearis and Kellicottia longispina were related to predation pressure, i.e. selectivity and cropping rates of C. vicinus . All four rotifer species were found to be consumed by C. vicinus whose predation rates showed a marked succession through the spring period and corresponded to changes in the relative abundance of the pelagic species. The highest predation rates exhibited by C. vicinus were on Synchaeta lakowitziana and Polyarthra spp., being 11.3 and 6.4 ind Cyclops –1 day–1 respectively. The activity of the predator switched among three types of preferred food during the spring period. The most preferred, Synchaeta, was replaced by Polyarthra after Synchaeta became extinct and these species were replaced by Keratella when both soft‐bodied forms were not available in sufficient quantities. Loricated species (K. cochlearis and K. longispina) were consumed at a slower rate. We calculated the proportion of rotifer production cropped day–1 in order to estimate the predation impact of C. vicinus , which ranged from 11.6 to more than 100% over time and rotifer species. This shows that relative predation impact can be high not only on species most strongly selected, but also on species which are not selected. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Study of the Decomposition of Reed (Phragmites australis ) as a Possible Source of Aquatic Humic Substances by Measuring the Natural Abundance of Stable Carbon Isotopes
Authors: V.‐Balogh Katalin , Présing Mátyás , Vörös Lajos , Tóth Noémi 
Published: February 2006

AbstractThe decomposition of leaf and steam litter of reed (P. australis) was measured both in the field and in the laboratory. The breakdown rates, the total carbon and the stable carbon isotope dynamics of reed litter were determined. The stable carbon isotope ratios of isolated humic substances (fulvic and humic acids) were also analysed. The δ13C value in reed remains increased from –26‰ to –24‰ for stems and from –27‰ to –26‰ for leaves. The dissolved fulvic and humic acids isolated from the experimental bottles (mean δ13C was –27.6‰) and the reservoir water were depleted in 13C (mean δ13C was –28.6‰) relative to the reed remains. The results show that reed litter is an important source of coloured aquatic humic substances. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Occurrence of Arbuscular Mycorrhizas and Dark Septate Endophytes in Hydrophytes from Lakes and Streams in Southwest China
Authors: Kai Wang , Zhiwei Zhao 
Published: February 2006

AbstractIn this study, the colonization of arbuscular mycorrhizas (AM) and dark septate endophytes (DSE) in 140 specimens of 32 hydrophytes collected from four lakes and four streams in southwest China were investigated. The arbuscular mycorrhizal fungi (AMF) and DSE colonization in these hydrophytes were rare. Typical AM structures were observed in one of the 25 hydrophytic species collected in lakes and six of the 17 species collected in streams.Spores of 10 identified AMF species and an unidentified Acaulospora sp. were isolated from the sediments. The identified AMF came from the four genera, Acaulospora, Gigaspora, Glomus and Scutellospora . Glomus and G. mosseae were the dominant genus and species respectively in these aquatic environments.The presence of DSE in hydrophytes was recorded for the first time. DSE occurred in one of the 25 hydrophyte species collected in lakes and three of the 17 species collected in streams. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Do Invertebrate Activity and Current Velocity Affect Fungal Assemblage Structure in Leaves?
Authors: Ferreira Verónica , Graça Manuel A. S. 
Published: February 2006

AbstractIn this study we assessed the effect of current velocity and shredder presence, manipulated in artificial channels, on the structure of the fungal assemblage colonizing alder (Alnus glutinosa(L.)Gaertner) leaves incubated in coarse and fine mesh bags. Fungal sporulation rates, cumulative conidial production and number of species of aquatic hyphomycetes were higher in leaves exposed to high rather than to low current velocity. The opposite was observed regarding Simpson's index (D) on the fungal assemblage. Some species of aquatic hyphomycetes were consistently stimulated in high current channels. No effect of shredders or of mesh type was observed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)