bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Sensitive Phases in Metal and Polymer Based Structural Materials for Health Monitoring
Authors: Asanuma Hiroshi
Published: July 2003

This paper describes new ideas the author has proposed to realize metal and polymer based sensitive structural material systems suitable for health monitoring without using commercially available sophisticated and expensive sensors. The following topics are mainly examined in this study: (1) Embedding a normal optical fiber in aluminum based materials such as SiC fiber reinforced aluminum composites to use as a sensor for fracture process monitoring; (2) forming an optical interference type strain sensor or an optical loss type strain sensor in host materials simply by embedding a singly or multiply notched optical fiber and breaking it at each notch in the host materials; (3) forming a multifunctional sensor in aluminum based materials for temperature and strain monitoring simply by embedding an oxidized nickel fiber in them.
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.
The Capabilities Approach and Gendered Education
Authors: Unterhalter Elaine
Published: July 2003

This article examines Amartya Sen's writings on the capabilities approach and education. Sen sometimes suggests a loose association between education and schooling. Elsewhere he concludes that one can read off the outputs of schooling as an indication of capabilities and an enhancement of freedom. While the capability approach provides a valuable way beyond human capital theorizing about education, Sen's writing fails to take account of the complex settings in which schooling takes place. Sometimes schooling does not entail an enhancement of capabilities and substantive freedom. South African policy responses to the HIV/AIDS epidemic highlight how using the capability approach to evaluation without paying attention to conditions of gender and race inequality yield only half the picture.
Challenging Deliberation
Authors: Levinson Meira
Published: July 2003

Civic education is a primary aim of public schooling in liberal democratic states, which rely on a well-educated, civic-minded citizenry for their perpetuation. Because liberal democracies can differ, it is important to decide for what kind of democracy schools should be educating. Recently, deliberative democracy has come into vogue as a political - and hence civic educational - goal. Because of differences in perspectives as a result of life experiences, however, racial, ethnic, economic, and/or religious minorities are disadvantaged in deliberative settings. Even if they fully participate, and even if all citizens welcome their participation, minority group members are unlikely to be able to influence debate appropriately. Furthermore, the steps that teachers or schools might take to overcome this problem in the future themselves impose serious costs on children, especially those who grow up in segregated minority communities. These costs may outweigh deliberative democracy's putative benefits over adversarial democracy.
Education, Reconciliation and Nested Identities
Authors: Spinner-Halev Jeff
Published: July 2003

In divided societies reconciliation between groups is an important, though difficult, goal. Democratic states always favor some group identities over others, making the idea of full reconciliation ever elusive. I argue that education alone cannot do much for reconciliation in divided societies, but can do so in tandem with a parallel political process of reconciliation. One way to push reconciliation through both is to construct a society that accepts the idea of nested identities; a state with nested identities accepts the different identities within it, though an overarching state identity is overlaid on top of these other identities. I suggest ways in which the idea of nested identities can be implemented in schools.
Liberal Feminism, Diversity and Education
Authors: Enslin Penny
Published: July 2003

Liberal feminism, like liberal political theory in general, is sometimes criticized for overemphasizing equality and the promotion of autonomy at the expense of valuing diversity. Some might thus see an approach to difference in education that is based on liberal feminism as a threat to cultural diversity. This article argues that although cultural diversity has some benefits, liberal feminism should not be deterred from promoting autonomy and equality for women by encouraging the alteration of practices that harm their interests. Siding with Susan Moller Okin's liberal feminism in Is Multiculturalism Bad for Women? the contrast between comprehensive and political liberalism in recent work by Okin and by Martha Nussbaum is explored. It is claimed that a liberal feminist approach to the education of women and girls would necessarily be a form of comprehensive liberalism.
A Philosophical Objection to Faith Schools
Authors: Hand Michael
Published: July 2003

This paper is a re-examination of the argument that faith schools ought to be abolished on the grounds that they are indoctrinatory. The premises of this argument are (1) that faith schools teach for belief in religious propositions, (2) that no religious proposition is known to be true, and (3) that teaching for belief in not-known-to-be-true propositions is indoctrinatory. I argue that the first two premises are true, but the third, as it stands, is false. However, the flaws in the third premise are relatively minor and the argument against faith schools can be reformulated to take account of them.
School Choice, Diversity and a Life of One's Own
Authors: Coleman Joe
Published: July 2003

Liberal proponents of school choice increasingly advance the diversity argument in support of programs such as vouchers. The diversity argument states that respect for the worldviews of parents requires allowing them to send their children to schools that reflect those views. But whatever its merits, such an argument cannot be made on behalf of adolescents insofar as these students have the same capacity to have a worldview upon which liberal respect for parental concerns is based. When it comes to high school, it is the students, not parents, who are the ones with a legitimate claim to the diversity argument. I explore whether the diversity argument is coherent if the same persons who are the recipients of education are also those who advance this argument. Ultimately, analysis reveals both principled and practical reasons that render the diversity argument incapable of justifying school choice for adolescents.
An Interview with Robert K. Fullinwider
Authors: Sardoč Mitja
Published: July 2003

In this interview, Professor Robert K. Fullinwider, Senior Research Scholar at the Institute for Philosophy and Public Policy, University of Maryland, provides an excellent and much needed overview of the debate on multiculturalism and `identity politics' and its relevance to educational theory. The interview also examines questions related to citizenship education, inclusion, and diversity in American public education. It also addresses several other important questions in contemporary political theory and philosophy of education, e.g. the civic purposes of public schooling, the sharp decline of civic culture over the past decades, issues of cultural diversity and value pluralism in contemporary liberal democracies.
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

The 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

We 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

Human 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

Notch1 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

Using 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

Hematopoiesis 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

The 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

One 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

Vascular 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

Antigens 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

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

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.
Plasminogen supports tumor growth through a fibrinogen-dependent mechanism linked to vascular patency
Authors: Palumbo Joseph S. , Talmage Kathryn E. , Liu Hong , La Jeunesse Christine M. , Witte David P. , Degen Jay L.
Published: July 2003

The growth of Lewis lung carcinoma (LLC) was sustained in plasminogen-deficient mice when transplanted into the dorsal skin but was dramatically suppressed in another anatomic location, the footpad. This unanticipated negative effect of plasminogen deficiency on footpad tumor growth was entirely relieved by superimposing a deficit in fibrinogen. This finding was not simply an unusual feature of LLC tumors—T241 fibrosarcoma growth in the footpad was also restricted by plasminogen deficiency in a fibrinogen-dependent manner. The probable mechanistic basis for suppression of tumor growth was revealed through transmission electron microscopy studies of tumor tissues. Occlusive microvascular thrombi were commonplace within footpad tumors from plasminogen-deficient mice, whereas no such lesions were observed within either dorsal skin tumors from plasminogen-deficient mice or footpad tumors from mice that also lacked fibrinogen. The data infer that tumor growth in the footpad of plasminogen-deficient mice is compromised as a function of the formation and persistence of vaso-occlusive thrombi that limit tumor blood supply. These studies indicate that plasminogen and fibrinogen can serve as critical determinants of tumor growth, but their relative importance is dependent on the tumor microenvironment. Furthermore, these studies suggest that one target of plasmin(ogen) relevant to tumor progression in vivo is intravascular fibrin.
Clonal hematopoiesis in familial polycythemia vera suggests the involvement of multiple mutational events in the early pathogenesis of the disease
Authors: Kralovics Robert , Stockton David W. , Prchal Josef T.
Published: July 2003

Familial clustering of malignancies provides a unique opportunity to identify molecular causes of cancer. Polycythemia vera (PV) is a myeloproliferative disorder due to an unknown somatic stem cell defect that leads to clonal myeloid hyperproliferation. We studied 6 families with PV. The familial predisposition to PV appears to follow an autosomal dominant inheritance pattern with incomplete penetrance. All examined females informative for a transcriptional clonality assay had clonal hematopoiesis. We excluded linkage between PV and a number of previously proposed candidate disease loci (c-mpl, EPOR, 20q, 13q, 5q, 9p). Therefore, mutations at these loci are unlikely primary causes of familial PV. The finding of erythropoietin-independent erythroid progenitors in healthy family members indicated the presence of the PV stem cell clone in their hematopoiesis. This finding, together with clonal hematopoiesis in the affected individuals, supports the hypothesis of multiple genetic defects involved in the early pathogenesis of PV. (Blood. 2003;102:3793-3796)
The nature of diversity and diversification at the ABO locus
Authors: Seltsam Axel , Hallensleben Michael , Kollmann Anke , Blasczyk Rainer
Published: July 2003

In this study we analyzed the complete genomic sequences, except intron 1, and 2 regulatory regions of 6 common (ABO*A101, ABO*A201, ABO*B101, ABO*O01, ABO*O02, and ABO*O03) and 18 rare ABO alleles, 3 of which were new. This was done by phylogenetic analysis and correlating sequence data with the ABO phenotypes. The study revealed multiple polymorphisms in noncoding regions. The intron-based phylogenetic analysis revealed 5 main lineages: ABO*A, ABO*B, ABO*O01, ABO*O02, and ABO*O03. The genomic sequences of most rare ABO alleles differed slightly from those of the common alleles. Singular mutations or hybrid alleles were most common, but a few exhibited mosaic sequence pattern containing multiple exon and/or intron motifs from other ABO lineages. Thus, both an accumulation of mutations as well as an assortment of the mutations by recombination seems to be responsible for the ABO gene diversity. The prevalence of replacement mutations indicates positive selection for allelic diversity. Phenotype-genotype correlation showed that sequence variations within the complete coding sequence can affect A- and B-antigen expression. All variant ABO*A/B alleles and one new ABO*O03-like allele were associated with weak ABO phenotypes. These findings are suggestive of the requirement of a comprehensive coding sequence database for sequence-based phenotype prediction.
A caspaselike activity is triggered by LPS and is required for survival of human dendritic cells
Authors: Franchi Luigi , Condò Ivano , Tomassini Barbara , Nicolò Chiara , Testi Roberto
Published: July 2003

Bacterial endotoxin (lipopolysaccharide [LPS]) is a potent inducer of human dendritic cell (DC) maturation and survival. Here we show that immature DCs exposed to LPS trigger an early and sustained caspaselike activity, which can be blocked by zVAD (z-Val-Ala-Asp), in the absence of detectable caspase 8 and caspase 10 activation, or poly(ADP-ribose) polymerase (PARP)–cleaving activity. Preventing LPS-induced caspaselike activation in DC results in massive cell death. Importantly, triggering of the caspaselike activity is required for LPS-induced activation of extracellular signal-regulated kinases (ERKs) and for LPS-induced up-regulation of cFLIP (Fas-associating protein with death domain–like interleukin-1β–converting enzyme [FLICE]–like inhibitory protein). Therefore, a caspase-dependent pathway initiated by LPS controls survival of human DCs.
Anti-D initially stimulates an Fc-dependent leukocyte oxidative burst and subsequently suppresses erythrophagocytosis via interleukin-1 receptor antagonist
Authors: Coopamah Malini D. , Freedman John , Semple John W.
Published: July 2003

Previous results have demonstrated that anti-D therapy in children with chronic auto-immune thrombocytopenic purpura (AITP) induced a significant increase in several pro- and anti-inflammatory plasma cytokines within 2 hours of administration. To investigate the biologic basis of these early in vivo responses, we developed a flow cytometric assay to measure Fc-dependent responses of human peripheral leukocytes with fluorescently labeled and anti-D–opsonized red blood cells (RBCs). When anti-D–opsonized RBCs were incubated with peripheral blood leukocytes, the earliest detectible event observed was a significant oxidative burst in both monocytes (P < .05) and granulocytes (P < .0001), characterized by the production of hydrogen peroxide (H2O2), peroxynitrite (ONOO–), superoxide (O –2), and hydroxyl (OH) by 10 minutes which declined by 1 hour. By 2 hours, the opsonized RBCs were phagocytosed, particularly by granulocytes (P < .001), but the phagocytosis subsequently declined by 6 hours of incubation. The decline in phagocytosis was correlated with a significant production of interleukin-1 receptor antagonist (IL1ra) by both monocytes (P = .036) and granulocytes (P = .0002) within 4 hours. None of these events occurred if the RBCs were coated with anti-D F(ab)′2 fragments. When recombinant IL1ra was titrated into the assay, phagocytosis of the opsonized RBCs was significantly inhibited (P = .002). Taken together, these results suggest that at least one mechanism of action of anti-D is via the production of the anti-inflammatory cytokine IL1ra which can negatively regulate the ability of leukocytes to phagocytose opsonized cells.
Profound loss of T-cell receptor repertoire complexity in cutaneous T-cell lymphoma
Authors: Yawalkar Nikhil , Ferenczi Katalin , Jones David A. , Yamanaka Keiichi , Suh Ki-Young , Sadat Sarah , Kupper Thomas S.
Published: July 2003

Cutaneous T-cell lymphoma (CTCL) is a malignancy of skin-homing T cells. A major feature of CTCL is profound immunosuppression, such that patients with advanced mycosis fungoides or Sézary syndrome have been compared with patients with advanced HIV disease and are susceptible to opportunistic infection. The etiology of this immunosuppression is unclear. We analyzed peripheral blood T cells of patients with CTCL with stage I to IV disease, using a sensitive beta-variable complementarity-determining region 3 spectratyping approach. Our data revealed a profound disruption of the complexity of the T-cell repertoire, which was universally observed in patients with advanced disease (stages III and IV), and present in up to 50% of patients with early-stage disease (stages I and II). In most patients, multiple monoclonal and oligoclonal complementarity-determining region 3 (CDR3) spectratype patterns in many different beta-variable families were seen. Equally striking was a reduction of normal T cells (as judged by absolute CD4 counts) across multiple beta-variable families. In general, CTCL spectratypes were reminiscent of advanced HIV spectratypes published elsewhere. Taken together, these data are most consistent with a global assault on the T-cell repertoire in patients with CTCL, a process that can be observed even in early-stage disease. (Blood. 2003;102:4059-4066)
Toll-like receptors stimulate human neutrophil function
Authors: Hayashi Fumitaka , Means Terry K. , Luster Andrew D.
Published: July 2003

The first immune cell to arrive at the site of infection is the neutrophil. Upon arrival, neutrophils quickly initiate microbicidal functions, including the production of antimicrobial products and proinflammatory cytokines that serve to contain infection. This allows the acquired immune system enough time to generate sterilizing immunity and memory. Neutrophils detect the presence of a pathogen through germ line-encoded receptors that recognize microbe-associated molecular patterns. In vertebrates, the best characterized of these receptors are Toll-like receptors (TLRs). We have determined the expression and function of TLRs in freshly isolated human neutrophils. Neutrophils expressed TLR1, 2, 4, 5, 6, 7, 8, 9, and 10—all the TLRs except TLR3. Granulocyte-macrophage colony-stimulating factor (GM-CSF) treatment increased TLR2 and TLR9 expression levels. The agonists of all TLRs expressed in neutrophils triggered or primed cytokine release, superoxide generation, and L-selectin shedding, while inhibiting chemotaxis to interleukin-8 (IL-8) and increasing phagocytosis of opsonized latex beads. The response to the TLR9 agonist nonmethylated CpG-motif-containing DNA (CpG DNA) required GM-CSF pretreatment, which also enhanced the response to the other TLR agonists. Finally, using quantitative polymerase chain reaction (QPCR), we demonstrate a chemokine expression profile that suggests that TLR-stimulated neutrophils recruit innate, but not acquired, immune cells to sites of infection. (Blood. 2003;102:2660-2669)
Formation of trisomies and their parental origin in hyperdiploid childhood acute lymphoblastic leukemia
Authors: Paulsson Kajsa , Panagopoulos Ioannis , Knuutila Sakari , Jee Kowan Ja , Garwicz Stanislaw , Fioretos Thoas , Mitelman Felix , Johansson Bertil
Published: July 2003

High hyperdiploidy, common in childhood acute lymphoblastic leukemia (ALL) with a favorable prognosis, is characterized by specific trisomies. Virtually nothing is known about its formation or pathogenetic impact. We evaluated 10 patients with ALL using 38 microsatellite markers mapped to 18 of the 24 human chromosomes to investigate the mechanisms underlying hyperdiploidy and to ascertain the parental origin of the trisomies. Based on the results, doubling of a near-haploid clone and polyploidization with subsequent losses of chromosomes could be excluded. The finding of equal allele dosage for tetrasomy 21 suggests that hyperdiploidy originates in a single aberrant mitosis, though a sequential gain of chromosomes other than 21 in consecutive cell divisions remains a possibility. Our study, the first to address experimentally the parental origin of trisomies in ALL, revealed no preferential duplication of maternally or paternally inherited copies of X, 4, 6, 9, 10, 17, 18, and 21. Trisomy 8 was of paternal origin in 4 of 4 patients (P = .125), and +14 was of maternal origin in 7 of 8 patients (P = .0703). Thus, the present results indicate that imprinting is not pathogenetically important in hyperdiploid childhood ALL, with the possible exception of the observed parental skewness of +8 and +14.
Evidence for a positive role of SHIP in the BCR-ABL–mediated transformation of primitive murine hematopoietic cells and in human chronic myeloid leukemia
Authors: Jiang Xiaoyan , Stuible Matthew , Chalandon Yves , Li Andra , Chan Wing Yiu , Eisterer Wolfgang , Krystal Gerald , Eaves Allen , Eaves Connie
Published: July 2003

Previous studies suggested that the SH2-containing inositol-5-phosphatase (SHIP) may play a tumor suppressor-like function in BCR-ABL–mediated leukemogenesis. To investigate this possibility, we first developed a new assay for quantitating transplantable multilineage leukemia-initiating cells (L-ICs) in hematopoietic stem cell (HSC)–enriched mouse bone marrow (BM) cells transduced with a BCR-ABL–GFP (green fluorescent protein) retrovirus. The frequency of L-ICs (1 of 430 Sca-1+lin– cells) was 7-fold lower than the frequency of HSCs in the Sca-1+lin– subset transduced with a control virus (1 of 65 cells). Forced BCRABL expression was also accompanied by a loss of regular HSC activity consistent with the acquisition of an increased probability of differentiation. Interestingly, the frequency and in vivo behavior of wild-type (+/+) and SHIP–/– L-ICs were indistinguishable, and in vitro, Sca-1+lin– BCR-ABL–transduced SHIP–/– cells showed a modestly reduced factor independence. Comparison of different populations of cells from patients with chronic myeloid leukemia (CML) in chronic phase and normal human BM showed that the reduced expression of full-length SHIP proteins seen in the more mature (CD34–lin+) leukemic cells is not mirrored in the more primitive (CD34+lin–) leukemic cells. Thus, SHIP expression appears to be differently altered in the early and late stages of differentiation of BCR-ABL–transformed cells, underscoring the importance of the cellular context in which its mechanistic effects are analyzed.
Dexamethasone accelerates catabolism of leukotriene C4in bronchial epithelial cells
Authors: Zaitsu M. , Hamasaki Y. , Tsuji K. , Matsuo M. , Fujita I. , Aoki Y. , Ishii E. , Kohashi O.
Published: June 2003

Leukotriene (LT)C4, a potent chemical mediator in bronchial asthma, is metabolised to the less active LTE4viaLTD4in two consecutive reactions catalysed by enzymes of the glutamyl transpeptidase and dipeptidase families. The activities of these catabolic enzymes may be influenced by glucocorticosteroids. This study was conducted to examine whether this inactivation of LTC4is affected by dexamethasone (DEX) in transformed human bronchial epithelial cells and normal human bronchial epithelial cells.

After incubation with DEX for 0–5 days, cells were resuspended in the presence of exogenous LTC4, and conversion of LTC4to LTE4was measured using high-performance liquid chromatography. γ‐Glutamyl transpeptidase (GGT) and GGT-related enzyme (GGTRE) messenger ribonucleic acid (mRNA) expression were examined using reverse transcriptase-polymerase chain reaction analysis, and GGT activity by enzyme assay.

Conversion to LTE4was accelerated by DEX pretreatment. GGTRE but not GGT mRNA expression was enhanced after incubation with DEX.

The results indicate that dexamethasone transcriptionally upregulates the activity of γ‐glutamyl transpeptidase-related enzyme in human bronchial epithelial cells, which accelerates inactivation of leukotriene C4viaconversion to leukotriene E4. This is a novel mechanism of glucocorticosteroids in human bronchial epithelial cells.
The role of genetic factors in occupational asthma: Table 1
Authors: Mapp C.E.
Published: June 2003

This article explores the influence of genetic factors on the development of sensitisation and occupational asthma (OA).

First, several types of studies aimed at examining the role of genes, as well as the role of gene-environment interactions in asthma, including the available data for OA specifically, were reviewed. Genetic approaches include linkage and allele-sharing analysis and segregation analysis. Secondly, deoxyribonucleic acid banking for epidemiological studies was focused upon, highlighting the factors to be considered in choosing the appropriate specimens for genotyping.

OA, like asthma, is a multifactorial condition and, to date, no ideal genetic study has been described to examine complex gene-environment interactions. Most studies in OA have examined human leukocyte antigen-associated polymorphisms with some nonreproducible results.

The search for genes in occupational asthma is still in progress, and much of the information obtained has been based on small sample sizes, using different strategies for the recruitment of subjects. The best methodological approach still needs to be determined and the results of genetic identification need to be confirmed in different samples.
Cytokine profiles in idiopathic pulmonary fibrosis suggest an important role for TGF‐β and IL-10
Authors: Bergeron A. , Soler P. , Kambouchner M. , Loiseau P. , Milleron B. , Valeyre D. , Hance A.J. , Tazi A.
Published: June 2003

Modulation of cytokine expression represents a potentially useful approach for the treatment of idiopathic pulmonary fibrosis (IPF).

To identify potential targets for such intervention, semi-quantitative reverse transcriptase-polymerase chain reaction was used to compare the expression of messenger ribonucleic acids (mRNAs) coding for 17 cytokines in lung tissue obtained from patients with IPF at the time of diagnosis and control subjects. Some cytokines were also studied at the protein level by immunohistochemical techniques.

mRNAs coding for all of the cytokines evaluated were detected in both control and fibrotic lung samples. Only transforming growth factor (TGF)‐β and interleukin (IL)-10 mRNAs were quantitatively increased in lung biopsies from patients with IPF compared with those of controls, results confirmed at the protein level by immunohistochemistry. Although mRNAs for platelet-derived growth factor (PDGF)-BB and keratinocyte growth factor (KGF) were expressed in similar amounts in lungs from patients with IPF and controls, localised accumulation of both factors was also observed in IPF. Hyperplastic alveolar epithelial cells were a prominent source of cytokines, where IL-10, PDGF-BB and KGF were present in increased amounts, although increased accumulation in fibroblasts, smooth-muscle cells and matrix components was also observed (PDGF-BB, TGF‐β).

These results offer new insights into the cytokines produced in the lung in idiopathic pulmonary fibrosis and suggest that modulation of the production of transforming growth factor‐β and interleukin-10 may represent a potentially useful therapeutic strategy for this disabling disease.