Mostrando recursos 141 - 160 de 29.127

  1. IMMUNOBIOLOGY Transcription factor Zfx controls BCR-induced proliferation and survival of B lymphocytes

    Teresita L. Arenzana; Matthew R. Smith-raska; Boris Reizis
    tion of B lymphocytes involve multiple rounds of B-cell receptor (BCR)–controlled proliferation and prolonged maintenance. We analyzed the role of transcription factor Zfx, a recently identified regulator of hemato-poietic stem cell maintenance, in B-cell de-velopmentandhomeostasis.Panhematopoi-etic or B cell–specific deletion of Zfx in the bone marrow blocked B-cell development at the pre-BCR selection checkpoint. Zfx deficiency in peripheral B cells caused accelerated B-cell turnover, depletion of mature recirculating B cells, and de-layed T-dependent antibody responses. In addition, the numbers and function of B-1 cell lineage were reduced. Zfx-deficient B cells showed normal proximal BCR signaling, but impaired BCR-induced proliferation and survival...

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    K. Masuda; D. Yamada; H. Koseki; H. Kawamoto Rcai; H. Watarai; S. Fujii; D. Yamada; A. Rybouchkin; S. Sakata; T. A. Endo; T. Toyoda; O. Ohara; H. Koseki; M. Taniguchi Riken
    showing that JAM-B/JAM-C interaction contributes to the retention of hematopoı̈etic cells within the bone marrow microenvironment. WS/PP-010-05 Heterogeneity among iPS clones with regard to B cell potential

  3. Histologic, immunohistochemical, and ultrastructural features of an intraocular sarcoma of a cat

    J. H. Stoltz; J. L. Carpenter; D. M. Albert; S. J. Vainisi; R. J. Munn
    There are numerous reports in the literature of feline in-traocular neoplasms. Metastatic and secondary (hematopoi-etic tissue origin) tumors are described most commonly, and lymphosarcoma is most regularly mentioned.8 Primary in-traocular neoplasms in cats are rare, with melanoma of the anterior uvea representing the most common type.7 Intra-ocular sarcomas other than melanomas are rare; osteosar-coma,6,10 chondrosarcoma,8 fibrosarcoma,l and poorly dif-ferentiated spindle cell sarcomal1,4 have been described. Chronic uveitis or previous ocular trauma years before usu-ally precede the sarcomas.1,4 Most of the sarcomas had diffuse involvement of the eye with effacement of much of the nor-mal architecture. All had various degrees of...

  4. Selective transendothelial migration of hematopoietic progenitor cells: a role in homing of progenitor cells. Blood 93: 149–156

    Kiyotoshi Imai; Masanobu Kobayashi; Jingxin Wang; Yoichi Ohiro; Jun-ichi Hamada; Yuko Cho; Masahiro Imamura; Manabu Musashi; Takeshi Kondo; Masuo Hosokawa; Masahiro Asaka
    To elucidate the mechanisms by which hematopoietic pro-genitor cells transmigrate via the bone marrow (BM) endothe-lial cells, we first established endothelial cell lines from BM and lung, and BM fibroblast cell lines; then we established an in vitro model of transendothelial migration of hematopoi-etic progenitor cells in the presence of chemoattractants secreted by BM fibroblast cells. The BM endothelial cells expressed vascular cell adhesion molecule-1 (VCAM-1), but the lung endothelial cells did not. The BM fibroblast cells secreted chemoattractants including stroma cell–derived factor (SDF)-1, which could attract hematopoietic progenitor cells to BM and activate the adhesion molecules expressed on hematopoietic...

  5. TRANSPLANTATION Monocyte-mediated T-cell suppression and augmented monocyte tryptophan catabolism after human hematopoietic stem-cell transplantation

    Ursula Hainz; Petra Obexer; Christiana Winkler; Peter Sedlmayr; Osamu Takikawa; Hildegard Greinix; Anita Lawitschka; Dietmar Fuchs; Stephan Ladisch; Andreas Heitger
    T-cell dysfunction after human hematopoi-etic stem-cell transplantation (HSCT) is generally attributed to intrinsic T-cell de-fects. Here we show that the characteris-tic impaired proliferative responses to polyclonal stimulation of post-HSCT pe-ripheral blood mononuclear cells (PB-MCs) were markedly (4-fold) improved by T-cell enrichment. Conversely, addback of post-HSCT monocytes to these en-riched T cells dampened their prolifera-tive responses, suggesting that post-HSCT monocytes effectively mediate T-cell suppression. As a mechanism pos-sibly contributing to monocyte-mediated T-cell suppression, we investigated mono-cyte tryptophan catabolism by indoleam-ine 2,3-dioxygenase into kynurenine, which has been implicated in regulating T-cell responses. Compared with con-trols, all post-HSCT monocyte-containing cell cultures (total PBMCs,...

  6. de Saúde Pública,

    Sociais Escola Nacional; Fundação Oswaldo Cruz; Rua Leopoldo Bulhões; José Luiz; Telles Almeida; Fermin Roland Schramm
    Paradigm shift, metamorphosis of medical ethics, and the rise of bioethics Transição paradigmática, metamorfose da ética médica e emergência da bioética

  7. Luis González de Paz Aquesta tesi doctoral està subjecta a la llicència Reconeixement- SenseObraDerivada 3.0. Espanya de Creative Commons.

    Esta Reconocimiento; Sinobraderivada España; Luis González De Paz; Dirigida Por; Dr. Antoni; Sisó Almirall; Dra Maria; Dolores Navarro Rubio
    Efectividad de las normas de ética en la práctica clínica habitual

  8. HEMATOPOIESIS The Soluble Interleukin-6 (IL-6) Receptor/IL-6 Fusion Protein Enhances In Vitro Maintenance and Proliferation of Human CD341CD382/low Cells Capable of Repopulating Severe

    Combined Immunodeficiency Mice; Orit Kollet; Ronit Aviram; Judith Chebath; Herzl Ben-hur; Arnon Nagler; Leonard Shultz; Michel Revel; Tsvee Lapidot
    In vitro maintenance and proliferation of human hematopoi-etic stem cells is crucial for many clinical applications. Early hematopoietic cells express low levels of FLT-3 and c-kit receptors, as well as the interleukin-6 (IL-6) receptor signal transducing element, gp130, but do not express IL-6 receptor itself. Therefore, we have attempted to maintain human cord blood or bone marrow CD341 cells ex vivo in serum-free cultures containing stem cell factor (SCF) and FLT-3 ligand (FL) alone or together with a new recombinant molecule of soluble IL-6 receptor fused to IL-6 (IL6RIL6 chimera). The effect of IL6RIL6 chimera on the proliferation and differentia-tion...


    De Bioética; Asociación Española; Bioética Ética; L. E. García-valdecasas; Identidad Y Conflicto; En La; Ética De; Los Implantes; L. E. Echarte; M. García-valdecasas
    Identity and conflicts in the ethics of neural implants

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    time. In this issue ofBlood,Dominici and col-leagues use amurinemodel for conducting a comprehensive set of serial transplantations to determinewhether this outcome is related to the transplantability of cellswith limited osteopoi-etic potential, or rather due to the engraftment of cellswith robust potential that are nevertheless subject to regulatory influences,whichprevent sustained therapeutic levels of donor osteopoi-esis.This elegant studydemonstrates that nor-mal bonemarrowdonor stemcellswith osteo-poietic potential home and engraft after transplantation, but that these cells offer only limited regenerative contribution tohost osteo-poiesis.Although theprecisemechanism for this lack of sustained contribution remains unclear, the authors use serial transplantation to suggest that it is not due to...

  11. HEMATOPOIESIS AND STEM CELLS STAT3 controls myeloid progenitor growth during emergency granulopoiesis

    Huiyuan Zhang; Hoainam Nguyen-jackson; Athanasia D. Panopoulos; Haiyan S. Li; Peter J. Murray; Stephanie S. Watowich
    (G-CSF) mediates “emergency ” granulo-poiesis during infection, a process that is mimicked by clinical G-CSF use, yet we understand little about the intracellu-lar signaling cascades that control de-mand-driven neutrophil production. Us-ing a murine model with conditional deletion of signal transducer and activa-tor of transcription 3 (STAT3) in bone marrow, we investigated the cellular and molecular mechanisms of STAT3 func-tion in the emergency granulopoiesis response to G-CSF administration or infection with Listeria monocytogenes, a pathogen that is restrained by G-CSF signaling in vivo. Our results show that STAT3 deficiency renders hematopoi-etic progenitor cells and myeloid precur-sors refractory to the growth-promoting functions...


    Didem Özçimen; Tufan Salan; Metallurgical Engineering Yıldız
    • Adsorbents were produced via thermal and chemical activation processes • Adsorption studies were conducted in batch equilibrium conditions for different dye concentrations • Chemically activated sewage sludge indicated better porous structure • Adsorption process demonstrated better compliance with pseudo-second order kin-etic model • Freundlich isotherm provided better fit to the equilibrium data for all adsorbents In this study, adsorbents were produced from sewage sludge via chemical and thermal activation processes. Experiments were carried out in a tubular fur-nace at a heating rate of 20 °C min-1 and temperature of 550 °C with a nitrogen flow rate of 400 mL...

  13. Peroxomonophosphoric Acid Oxidations: Kinetics and Mechanism of Oxidation of

    Aliphatic Aldehydes; S. Ch; Dharma Rao; Abhina K. P; Surendra N. Mahapatro
    The peroxomonophosphoric acid (PMPA) oxidation of six aliphatic aldehydes has been studied in the pH range 0-1 3. The reactions are second order, first order each in [aldehyde] and [PMPA] at constant pH. In alkaline medium the stoicheiometric ratio of PMPA to aldehyde is 1.0. In acid medium the ratio is significantly higher (1.5) pointing to the fact that an oxidation reaction and a carbonyl-assisted decom-position of P M PA occur simultaneously through a common intermediate. The pH-rate dependence was complex. A suitable rate law in a limited pH range 0-3 has been derived. We have been recently interested in...

  14. HEMATOPOIESIS Forced expression of Nanog in hematopoietic stem cells results in a T-cell disorder

    Yosuke Tanaka; Takumi Era; Shin-ichi Nishikawa; Shin Kawamata
    Nanog is a key molecule involved in the maintenance of the self-renewal of undif-ferentiated embryonic stem (ES) cells. In this work we investigate whether Nanog can enhance self-renewal in hematopoi-etic stem cells. Contrary to our expecta-tion, no positive effect of Nanog transduc-tion was detected in bone marrow reconstitution assays. However, recipi-ents of Nanog-transduced (Nanog) hema-topoietic stem cells (HSCs) invariantly develop a unique disorder typified by an atrophic thymus occupied by Nanog-expressing T-cell receptor–positive (TCR) cells (Nanog T cells). All thymi are eventually occupied by Nanog T cells with CD25CD44 surface phenotype that home selectively to the thymus on trans-fer and...

  15. America, patient education, progressive caution

    Eta S. Berner; Amarinder Singh S; Kenneth W. Goodman; Evaluación Y Estándares; O Consumidor; De Saúde; Informática Ética; Avaliação E Modelos
    Abstract: This article discusses the ethical issues involved in consumer health informatics –specifically those issues surrounding the provision of medical information for patients on the World Wide Web. The discussion includes concerns and suggestions relating to: quality control and error avoidance, Internet governance and Web site responsibility, and intellectual property and control. These issues are argued to be of exceptional importance in the developing world, including Latin America and the Caribbean.

  16. Age-associated epigenetic drift: implications, and a case of epigenetic thrift

    Andrew E. Teschendorff; James West; Stephan Beck
    It is now well established that the genomic landscape of DNA methylation (DNAm) gets altered as a function of age, a process we here call ‘epigenetic drift’. The biological, functional, clinical and evolutionary significance of this epigenetic drift, however, remains unclear. We here provide a brief review of epigenetic drift, focusing on the potential implications for ageing, stem cell biology and disease risk prediction. It has been demonstrated that epigenetic drift affects most of the genome, suggesting a global deregulation of DNAm patterns with age. A com-ponent of this drift is tissue-specific, allowing remarkably accurate age-predictive models to be constructed....

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    e44 A 23-year-old patient with recent history of hematopoi-etic stem cell transplantation as a result of a relapse of a cortical T-cell lymphoma presented with dyspnea and recur-rent nightly tachycardia. The initial ECG showed ST-segment depression in leads I and II and over the anterior wall, as well as tachycardia (heart rate, 110 bpm; Figure 1). The tro-ponin test was positive (1.780 μg/L; normal, <0.014 μg/L). Transthoracic echocardiography showed uniform thickening of the left ventricular wall with global hypokinesia and a mod-erate pericardial effusion without cardiac tamponade (Movie I in the online-only Data Supplement). For further diagnostic workup, cardiac magnetic...


    Paul C. Hooks; Ph. D; Jeffrey S. Levin
    Using ethnographic research methods in a sample of institutionalized male schizophrenics, an emic typology of patient social indentities was derived. Interview and observational data yielded three general status classes comprising thirteen associated identities: killer, fighter, assaultive person, fag, rapist, doper, drunk, victim, con, nut, weirdo, snitch, and disoriented. An individual’s social identity varied depending upon his current setting within the hospital (official, private, patient-staff interaction, or outside). This emic-derived typology is con-trasted with the etic typologies which dominate the literature (e.g. Goffman, Salisbury and Henry), and the importance of ethnographic study in social psychiatry is highlighted.

  19. HEMATOPOIESIS In vivo fate-tracing studies using the Scl stem cell enhancer: embryonic hematopoietic stem cells significantly contribute to adult hematopoiesis

    Joachim R. Göthert; Sonja E. Gustin; Mark A. Hall; Anthony R. Green; David J. Izon; C. Glenn Begley
    Evidence for the lineage relationship be-tween embryonic and adult hematopoi-etic stem cells (HSCs) in the mouse is primarily indirect. In order to study this relationship in a direct manner, we ex-pressed the tamoxifen-inducible Cre-ERT recombinase under the control of the stem cell leukemia (Scl) stem-cell en-hancer in transgenic mice (HSC-SCL-Cre-ERT). To determine functionality, HSC-SCL-Cre-ERT transgenics were bred with Cre reporter mice. Flow cytometric and transplantation studies revealed tamox-ifen-dependent recombination occurring in more than 90 % of adult long-term HSCs, whereas the targeted proportion within mature progenitor populations was sig-nificantly lower. Moreover, the transgene was able to irreversibly tag embryonic HSCs...

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    Alberto Bosi; Benedetta Bartolozzi; Ro M. Vannucchi; Ra Orsi; Stefano Guidi; Pierluigi Rossi Ferrini
    haematologica vol. 87(4):april 2002 scientific correspondence (9,158 vs 188,815 DNA copies/mL, p=0.038, Mann-Whitney test) with a similar trend also for blood (6,307 vs 9,440 DNA copies/mL; p=0.070). Patients who failed to respond to cidofovir were treated with ganciclovir ± foscavir; however, three patients died, two because of CMV-related interstitial pneumonia, and one because of thrombotic thrombocytopenic purpura. Cidofovir treatment was well tolerated, and neither renal nor hematopoi-etic toxicity was observed. In a recent report from the Infectious Disease Working Party of the EBMT,7 cidofovir was shown to be effective in both primary and secondary pre-emptive therapy. In that study, 10/20...

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