bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of a High Sampling Rate Time-Domain Multiplexing Fiber-Optic Sensor System
Authors: Levin Klas , Matrat Jérôme , Gunnarsson Ola 
Published: July 2003

A fiber-optic system for continuous high sampling rate measurement of strain is presented in this paper. It is clear that many applications require a monitoring system with high sampling rate capability and the ability to multiplex many sensors. This has led to the definition and development of a time-domain multiplexed system for measurement of strain and temperature. The system concept is based on short-pulse interferometry and Bragg-grating reflective elements. Time-domain multiplexing is achieved by using an optical amplitude modulator, synchronized with the triggering of light pulses, as a switch to select the reflected pulses from a particular sensor. The sequentially queried sensors all have the same spectral characteristics, with the number of sensors being limited by the available light intensity, the reflectivity of the sensors and the sensitivity of the detection system. The current version of the optical system has a fast digital signal processor (DSP), which increases the attainable sampling rates in the order of 100kHz, divided among sensors. The dedicated DSP controls the system and performs all data reduction tasks autonomously in real-time, storing the results in its memory. The capabilities of this system are evaluated in the present work. A series of strain experiments, involving surface-attached sensors were conducted to evaluate the system performance. It was shown that the system was capable of measuring strains at high sampling rates as well as to determine operational loads at low frequency ranges.
Assessment of the State of Condition of Prestressed Concrete Structures with Innovative Measurement Techniques
Authors: Hariri Karim , Holst Alex , Wichmann Hans-Joachim , Budelmann Harald 
Published: July 2003

The reliability of tensile elements is a requirement for the safety of prestressed structures. Besides many other data, the assessment of the load-carrying capacity of a prestressed concrete structure requires the knowledge of the actual force of the tendons and their corrosion state as well as the localization of fractures. Neither for grouted interior nor for ungrouted exterior tendons non destructive and reliable methods to measure the prestress and to assess the corrosion activity or to locate tendon fractures are available today. This contribution reports on actual research projects, dealing with fiber optic sensors to measure deformations and dealing with the variation of high frequency damping of steel tendons in concrete members due to corrosion. Furthermore a high-frequency-method is used to locate fracture in tendons. First applications of some of these innovative techniques on a real structure are presented: the Herrenbrücke-bridge in Lübeck. Since three winters, measurements on this prestressed concrete bridge assessing its state of condition are carried out.
Peptides containing a dominant T-cell epitope from red cell band 3 have in vivo immunomodulatory properties in NZB mice with autoimmune hemolytic anemia
Authors: Shen Chia-Rui , Youssef Abdel-Rahman , Devine Anne , Bowie Laura , Hall Andrew M. , Wraith David C. , Elson Christopher J. , Barker Robert N. 
Published: July 2003

AbstractThe major target of the pathogenic red blood cell (RBC) autoantibodies in New Zealand black (NZB) mice is the anion channel protein band 3, and CD4+ T cells from NZB mice respond to band 3. Here, we demonstrate that a band 3 peptide 861-875, which is the predominant sequence recognized by NZB T cells in vitro, bears a dominant helper epitope able to modulate the autoimmune hemolyic anemia in vivo. The development of RBC-bound autoantibodies and anemia was accelerated in NZB mice injected with peptide 861-874, which is relatively insoluble, and inhalation of the peptide primed T cells for both peptide 861-874 and band 3 responses. By contrast, inhalation of a soluble analog (Glu861, Lys875) of peptide 861-874 deviated the autoimmune response toward a T helper-2 (Th2) profile, with marked increases in the ratio of interleukin-4 to interferon-γ produced by splenic T cells responding in vitro to either peptide 861-874 or band 3. Moreover, in mice that had received such treatment, the proportion of RBC-bound immunoglobulin G (IgG) molecules that were of the Th2-associated IgG1 isotype was also increased, and anemia was less severe. It is concluded that NZB autoimmune hemolytic anemia is helper dependent and that nasal administration of different peptides containing the dominant T-cell epitope can have potentially detrimental or beneficial effects on the disease. (Blood. 2003; 102:3800-3806)
Dendritic cell subsets in blood and lymphoid tissue of rhesus monkeys and their mobilization with Flt3 ligand
Authors: Coates P. Toby H. , Barratt-Boyes Simon M. , Zhang Linyou , Donnenberg Vera S. , O'Connell Peta J. , Logar Alison J. , Duncan F. Jason , Murphey-Corb Michael , Donnenberg Albert D. , Morelli Adrian E. , Maliszewski Charles R. , Thomson Angus W. 
Published: July 2003

AbstractWe provide phenotypic and functional evidence of premonocytoid dendritic cells (DCs) and preplasmacytoid DCs in blood and of corresponding DC subsets in secondary lymphoid tissue of rhesus monkeys. Subsets were identified and sorted by 4-color flow cytometry using antihuman monoclonal antibodies cross-reactive with rhesus monkey. To mobilize pre-DC subsets, fms-like tyrosine 3 kinase ligand (Flt3L; 100 μg/kg subcutaneously) was administered for 10 days. Presumptive pre-DC subsets were identified within the lineage- (Lin-) major histocompatibility complex (MHC) class II+ fraction of blood mononuclear cells. Premonocytoid DCs were CD11c+CD123- (interleukin-3Rα- [IL-3Rα-]). Preplasmacytoid DCs were characterized as CD11c-CD123++ Flt3L increased the CD11c+ pre-DC (7-fold) and CD123++ pre-DC subsets (3-fold) in blood. The freshly isolated CD11c+ pre-DC subset induced modest proliferation of naive allogeneic T cells. After overnight culture with granulocyte macro-phage-colony-stimulating factor (GMCSF) and CD40L, both subsets up-regulated surface costimulatory molecules, and CD11c+ pre-DCs became potent allostimulators. Freshly isolated CD123++ pre-DCs showed typical plasmacytoid morphology and, when cultured with IL-3 and CD40L for 72 hours, developed mature DC morphology. Following stimulation with CD40L, CD11c+ pre-DCs secreted increased levels of IL-12p40. Importantly, herpes simplex virus-stimulated CD123++ pre-DCs, but not CD11c+ pre-DCs, secreted interferon-α (IFN-α). Corresponding DC subsets were identified by flow analysis and immunohistochemistry in lymph nodes wherein both populations were increased 2- to 3-fold by Flt3L administration. CD123+ pre-DCs produced IFN-α in response to in vivo viral infection. Thus, rhesus monkeys exhibit 2 distinct DC precursor populations that closely resemble those of humans. Both are mobilized into blood and lymphoid tissue by Flt3L, offering potential for their further characterization and possible therapeutic application. (Blood. 2003;102:2513-2521)
Selective suppression of IL-12 production by human herpesvirus 6
Authors: Smith Alison , Santoro Fabio , Di Lullo Giulia , Dagna Lorenzo , Verani Alessia , Lusso Paolo 
Published: July 2003

AbstractHuman herpesvirus 6 (HHV-6) is a potentially immunosuppressive agent that has been suggested to act as a cofactor in the progression of HIV disease. Exposure of human macrophages to HHV-6A or HHV-6B profoundly impaired their ability to produce interleukin 12 (IL-12) upon stimulation with interferon-γ (IFN-γ) and lipopolysaccharide (LPS). By contrast, the production of tumor necrosis factor–α (TNF-α); regulated on activation, normal T-cell expressed and secreted (RANTES); and macrophage inflammatory protein 1β (MIP-1β) was not negatively affected. To exclude the involvement of IL-12–suppressive cytokines, such as IL-10 and TNF-α, the viral stocks were fractionated by ultra-centrifugation. The bulk of the suppressive activity was recovered within the virion-rich pelleted fraction that was virtually devoid of such cytokines. IL-12 suppression was independent of viral replication, and the effect was not abrogated upon ultraviolet-light inactivation of the viral inoculum. The mechanism of HHV-6–mediated IL-12 suppression was investigated by RNase protection assays, which demonstrated unaltered levels of IL-12 p35 mRNA and only a modest reduction in p40 mRNA, which was insufficient to account for the near-complete loss of both extracellular and intracellular IL-12 protein. Moreover, both the IFN-γ and the LPS signaling pathways were intact in HHV-6–treated cells. These data suggest that HHV-6 can dramatically affect the generation of effective cellular immune responses, providing a novel potential mechanism of HHV-6–mediated immunosuppression.
Sustained Notch1 signaling instructs the earliest human intrathymic precursors to adopt a γδ T-cell fate in fetal thymus organ culture
Authors: García-Peydró Marina , de Yébenes Virginia G. , Toribio María L. 
Published: July 2003

AbstractNotch1 activity is essential for the specification of T-lineage fate in hematopoietic progenitors. Once the T-cell lineage is specified, T-cell precursors in the thymus must choose between αβ and γδ lineages. However, the impact of Notch1 signaling on intrathymic pro-T cells has not been addressed directly. To approach this issue, we used retroviral vectors to express constitutively active Notch1 in human thymocyte progenitors positioned at successive developmental stages, and we followed their differentiation in fetal thymus organ culture (FTOC). Here we show that sustained Notch1 signaling impairs progression to the double-positive (DP) stage and efficiently diverts the earliest thymic progenitors from the main αβ T-cell pathway toward development of γδ T cells. The impact of Notch1 signaling on skewed γδ production decreases progressively along intrathymic maturation and is restricted to precursor stages upstream of the pre-T-cell receptor checkpoint. Close to and beyond that point, Notch1 is not further able to instruct γδ cell fate, but promotes an abnormal expansion of αβ-committed thymocytes. These results stress the stage-specific impact of Notch1 signaling in intrathymic differentiation and suggest that regulation of Notch1 activity at defined developmental windows is essential to control αβ versus γδ T-cell development and to avoid deregulated expansion of αβ-lineage cells. (Blood. 2003;102:2444-2451)
The epidermal growth factor–like domains of the human EMR2 receptor mediate cell attachment through chondroitin sulfate glycosaminoglycans
Authors: Stacey Martin , Chang Gin-Wen , Davies John Q. , Kwakkenbos Mark J. , Sanderson Ralph D. , Hamann Jörg , Gordon Siamon , Lin Hsi-Hsien 
Published: July 2003

AbstractUsing multivalent protein probes, an evolutionarily conserved endogenous ligand for EMR2, a human myeloid cell–restricted EGF-TM7 receptor, was identified on the surface of a number of adherent cell lines. In addition, in situ staining of the ligand has revealed specific in vivo patterns consistent with a connective tissue distribution. The interaction is conserved across species and mediated exclusively by the largest EMR2 isoform containing 5 epidermal growth factor (EGF)–like modules. Antibody-blocking studies subsequently revealed that the fourth EGF-like module constitutes the major ligand-binding site. The largest isoform of CD97, a related EGF-TM7 molecule containing an identical EGF-like module, also binds to the putative EMR2 ligand. Through the use of mutant Chinese hamster ovary (CHO) cell lines defective in glycosaminoglycans (GAGs) biosynthesis as well as the enzymatic removal of specific cell surface GAGs, the molecular identity of the EMR2 ligand was identified as chondroitin sulfate (CS). Thus, exogenous CS GAGs blocked the EMR2-ligand interaction in a dose-dependent manner. EMR2-CS interaction is Ca2+- and sulphation-dependent and results in cell attachment. This is the first report of a GAG ligand for the TM7 receptors extending the already vast repertoire of stimuli of the GPCR superfamily.
Lysophospholipids synergistically promote primitive hematopoietic cell chemotaxis via a mechanism involving Vav 1
Authors: Whetton Anthony D. , Lu Yuning , Pierce Andrew , Carney Louise , Spooncer Elaine 
Published: July 2003

AbstractHematopoiesis is sustained by the proliferation and development of an extremely low number of hematopoietic stem cells resident in the bone marrow. These stem cells can migrate from their bone marrow microenvironment and can be found at low levels in the peripheral blood. The factors that regulate egress or ingress of the stem cells from the marrow include cytokines and chemokines. This process of stem cell trafficking is fundamental to both stem cell biology and stem cell transplantation. We show that primitive hematopoietic cells with cobblestone area–forming cell activity express receptors for and display enhanced motility in response to a new class of stem cell agonists, namely lysophospholipids. These agents synergistically promote chemokinestimulated cell chemotaxis, a process that is crucial in stem cell homing. The response to lysophospholipids is mediated by Rac, Rho, and Cdc42 G proteins and the hematopoietic-specific guanyl nucleotide exchange factor Vav 1. Inhibitor studies also show a critical role for phosphatidylinositol 3 kinase (PI3K). Lipid mediators, therefore, regulate the critical process of primitive hematopoietic cell motility via a PI3K- and Vav-dependent mechanism and may govern stem cell movement in vivo. These results are of relevance to understanding stem cell trafficking during bone marrow transplantation.
B-cell–specific transcription factor BACH2 modifies the cytotoxic effects of anticancer drugs
Authors: Kamio Takuya , Toki Tsutomu , Kanezaki Rika , Sasaki Shinya , Tandai Satoru , Terui Kiminori , Ikebe Dai , Igarashi Kazuhiko , Ito Etsuro 
Published: July 2003

AbstractThe transcription factor Bach2, a member of the CNC family of proteins, binds to the Maf recognition element (MARE) by forming homodimers or dimerizing with small Maf transcription factors. Bach2-expressing cells show reduced proliferation and undergo spontaneous cell death. The inhibition of BCR/ABL tyrosine kinase activity by STI571 in chronic myeloid leukemia (CML) cell lines and CD34+ cells from patients with CML in lymphoid crisis results in induction of BACH2 expression. We show here that BACH2 modifies the in vitro cytotoxicity of anticancer drugs. The cytotoxic effects of commonly used anticancer agents were studied by overexpression of BACH2 in RAJI lymphoid cells, a cell line that does not express endogenous BACH2. Cell growth inhibition was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Clones overexpressing BACH2 were more sensitive to etoposide, doxorubicin, and cytarabine than control RAJI cells, whereas there were no significant differences in the sensitivity of either cells to methotrexate or vincristine. Interestingly, we found that the former drugs were oxidative stressors that induced the nuclear accumulation of BACH2. In contrast, methotrexate or vincristine did not induce production of intracellular reactive oxygen species (ROS) and nuclear accumulation of BACH2. These results, coupled with our previous data showing that BACH2 promotes oxidative stress-induced cell death, suggest that combination chemotherapy involving STI571 and anticancer drugs that produce ROS may be of benefit in the treatment of Philadelphia chromosome 1 (Ph1)–positive leukemia.
Identification of an autoantigen on the surface of apoptotic human T cells as a new protein interacting with inflammatory group IIA phospholipase A2
Authors: Boilard Eric , Bourgoin Sylvain G. , Bernatchez Chantale , Surette Marc E. 
Published: July 2003

AbstractOne of the most studied secreted phospholipases A2 (sPLA2), the group IIA sPLA2, is found at high levels in inflammatory fluids of patients with autoimmune diseases. A characteristic of group IIA sPLA2 is its preference for negatively charged phospholipids, which become exposed on the extracellular leaflet of apoptotic cell membranes. We recently showed that low molecular weight heparan sulfate proteoglycans (HSPGs) and uncharacterized detergent-insoluble binding site(s) contribute to the enhanced binding of human group IIA PLA2 (hGIIA) to apoptotic human T cells. Using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry we now identify vimentin as the major HSPG-independent binding protein of hGIIA on apoptotic primary T lymphocytes. Vimentin is partially exposed on the surface of apoptotic T cells and binds hGIIA via its rod domain in a calcium-independent manner. Studies with hGIIA mutants showed that specific motifs in the interfacial binding surface are involved in the interaction with vimentin. The sPLA2 inhibitor LY311727, but not heparin, inhibited this interaction. In contrast, heparin but not LY311727 abrogated the binding of hGIIA to cellular HSPGs. Importantly, vimentin does not inhibit the catalytic activity of hGIIA. Altogether, the results show that vimentin, in conjunction with HSPGs, contributes to the enhanced binding of hGIIA to apoptotic T cells.
Exposure to fluid shear stress modulates the ability of endothelial cells to recruit neutrophils in response to tumor necrosis factor-α: a basis for local variations in vascular sensitivity to inflammation
Authors: Sheikh Sajila , Rainger G. Ed , Gale Zoe , Rahman Mahbub , Nash Gerard B. 
Published: July 2003

AbstractVascular endothelial cells are able to sense changes in the forces acting on them and respond, for instance, by modifying expression of a range of genes. However, there is little information on how such responses are integrated to modify homeostatic functions. We hypothesized that different shear stresses experienced in different regions of the circulation might influence endothelial sensitivity to inflammatory stimuli. We cultured human endothelial cells in tubes and exposed them for varying periods to shear stresses ranging from those typically found in postcapillary venules to those in arteries. When tumor necrosis factor-α was included in the flow cultures, we found startling differential effects of shear stress on the ability of endothelial cells to induce adhesion and migration of flowing neutrophils. Compared with static cultures, endothelial cells cultured at low shear stress (0.3 Pa) captured similar numbers of neutrophils but failed to induce their transendothelial migration. After exposure of endothelial cells to high shear stress (1.0 or 2.0 Pa), capture of neutrophils was largely ablated. The modification in response was detectable after 4 hours of exposure to flow but was much greater after 24 hours. From analysis of gene expression, loss of capture or migration was attributable to reduction in tumor necrosis factor–induced expression of selectins or CXC-chemokines, respectively. Thus, conditioning of endothelial cells by different flow environments may underlie variations in susceptibility to inflammation between different tissues or parts of the vascular tree.
Functional leukemia-associated antigen-specific memory CD8+ T cells exist in healthy individuals and in patients with chronic myelogenous leukemia before and after stem cell transplantation
Authors: Rezvani Katayoun , Grube Matthias , Brenchley Jason M. , Sconocchia Giuseppe , Fujiwara Hiroshi , Price David A. , Gostick Emma , Yamada Ko , Melenhorst Jan , Childs Richard , Hensel Nancy , Douek Daniel C. , Barrett A. John 
Published: July 2003

AbstractAntigens implicated in the graft-versus-leukemia (GVL) effect in chronic myeloid leukemia (CML) include WT1, PR1, and BCR-ABL. To detect very low frequencies of these antigen-specific CD8+ T cells, we used quantitative polymerase chain reaction (qPCR) to measure interferon-γ (IFN-γ) mRNA production by peptide-pulsed CD8+ T cells from HLA-A*0201+ healthy volunteers and from patients with CML before and after allogeneic stem cell transplantation (SCT). Parallel assays using cytomegalovirus (CMV) pp65 tetramers demonstrated the IFN-γ copy number to be linearly related to the frequency of tetramer-binding T cells, sensitive to frequencies of 1 responding CD8+ T cell/100 000 CD8+ T cells. Responses to WT1 and PR1 but not BCR-ABL were detected in 10 of 18 healthy donors. Responses to WT1, PR1, or BCR-ABL were observed in 9 of 14 patients with CML before SCT and 5 of 6 after SCT, often to multiple epitopes. Responses were higher in patients with CML compared with healthy donors and highest after SCT. These antigen-specific CD8+ T cells comprised central memory (CD45RO+CD27+CD57–) and effector memory (CD45RO–CD27–CD57+) T cells. In conclusion, leukemia-reactive CD8+ T cells derive from memory T cells and occur at low frequencies in healthy individuals and at higher frequencies in patients with CML. The increased response in patients after SCT suggests a quantitative explanation for the greater effect of allogeneic SCT.
DOCK2 regulates Rac activation and cytoskeletal reorganization through interaction with ELMO1
Authors: Sanui Terukazu , Inayoshi Ayumi , Noda Mayuko , Iwata Eiko , Stein Jens V. , Sasazuki Takehiko , Fukui Yoshinori 
Published: July 2003

Abstract
Although the migratory property of lymphocytes is critical for protective immunity, tissue infiltration of lymphocytes sometimes causes harmful immune responses. DOCK2 plays a critical role in lymphocyte migration by regulating actin cytoskeleton through Rac activation, yet the mechanism by which DOCK2 activates Rac remains unknown. We found that DOCK2 associates with engulfment and cell motility (ELMO1) through its Srchomology 3 (SH3) domain. When DOCK2 was expressed in T-hybridoma cells lacking endogenous expression of DOCK2, Rac activation and actin polymerization were induced. However, such responses were not elicited by the DOCK2 mutant lacking the region required for ELMO1 binding. On the other hand, we found that the expression of ELMO1 induces Rac activation in the plasmacytoma cells expressing DOCK2 but not ELMO1. These results indicate that the association of DOCK2 with ELMO1 is critical for DOCK2-mediated Rac activation, thereby suggesting that their association might be a therapeutic target for immunologic disorders caused by lymphocyte infiltration.
Targeting of the N-terminal coiled coil oligomerization interface of BCR interferes with the transformation potential of BCR-ABL and increases sensitivity to STI571
Authors: Beissert Tim , Puccetti Elena , Bianchini Andrea , Güller Saskia , Boehrer Simone , Hoelzer Dieter , Ottmann Oliver Gerhard , Nervi Clara , Ruthardt Martin 
Published: July 2003

Abstract
Translocations involving the abl locus on chromosome 9 fuses the tyrosine kinase c-ABL to proteins harboring oligomerization interfaces such as BCR or TEL, enabling these ABL-fusion proteins (X-ABL) to transform cells and to induce leukemia. The ABL kinase activity is blocked by the ABL kinase inhibitor STI571 which abrogates transformation by X-ABL. To investigate the role of oligomerization for the transformation potential of X-ABL and for the sensitivity to STI571, we constructed ABL chimeras with oligomerization interfaces of proteins involved in leukemia-associated translocations such as BCR, TEL, PML, and PLZF. We assessed the capacity of these chimeras to form high molecular weight (HMW) complexes as compared with p185(BCR-ABL). There was a direct relationship between the size of HMW complexes formed by these chimeras and their capacity to induce factor independence in Ba/F3 cells, whereas there was an inverse relationship between the size of the HMW complexes and the sensitivity to STI571. The targeting of the oligomerization interface of p185(BCR-ABL) by a peptide representing the coiled coil region of BCR reduced its potential to transform fibroblasts and increased sensitivity to STI571. Our results indicate that targeting of the oligomerization interfaces of the X-ABL enhances the effects of STI571 in the treatment of leukemia caused by X-ABL.