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  • Electronic Resource  (4)
  • Immunohistochemistry  (2)
  • B-Zell-Lymphome  (1)
  • Cytoskeleton  (1)
  • 1
    ISSN: 1432-2307
    Keywords: Cytoskeleton ; Wound healing ; Fibrosis ; Extracellular matrix ; Cytokine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Granulation tissue fibroblasts (myofibroblasts) develop several ultrastructural and biochemical features of smooth muscle (SM) cells, including the presence of microfilament bundles and the expression of α-SM actin, the actin isoform present in SM cells and myoepithelial cells and particularly abundant in vascular SM cells. Myofibroblasts have been suggested to play a role in wound contraction and in retractile phenomena observed during fibrotic diseases. When contraction stops and the wound is fully epithelialized, myofibroblasts containing α-SM actin disappear, probably as a result of apoptosis, and the scar classically becomes less cellular and composed of typical fibroblasts with well-developed rough endoplasmic reticulum but with no more microfilaments. In contrast, α-SM actin expressing myofibroblasts persist in hypertrophic scars and in fibrotic lesions of many organs, including stroma reaction to epithelial tumours, where they are allegedly involved in retractile phenomena as well as in extracellular matrix accumulation. The mechanisms leading to the development of myofibroblastic features remain to be investigated. In vivo and in vitro investigations have shown that γ-interferon exerts an antifibrotic activity at least in part by decreasing α-SM actin expression whereas heparin increases the proportion of α-SM actin positive cells. Recently, we have observed that the subcutaneous administration of transforming growth factor-β1 to rats results in the formation of a granulation tissue in which α-SM actin expressing myofibroblasts are particularly abundant. Other cytokines and growth factors, such as platelet-derived growth factor, basic fibroblast growth factor and tumour necrosis factor-α, despite their profibrotic activity, do not induce α-SM actin in myofibroblasts. In conclusion, fibroblastic cells are relatively undifferentiated and can assume a particular phenotype according to the physiological needs and/or the microenvironmental stimuli. Further studies on fibroblast adaptation phenomena appear to be useful for the understanding of the mechanisms of development and regression of pathological processes such as wound healing and fibrocontractive diseases.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Der Pathologe 21 (2000), S. 39-54 
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Chronische myeloische Leukämie ; Megakaryozyten ; Fasern ; Erythropoese ; Makrophagen ; Klinische Befunde ; Immunhistochemie ; Knochenmarkbiopsie ; Key words Chronic myelogenous leukemia ; Megakaryocytes ; Fibers ; Erythroid precursors ; Macrophages ; Clinical findings ; Immunohistochemistry ; Morphometry ; Bone marrow biopsies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary An immunohistochemical and morphometric study was performed on bone marrow biopsies in 604 patients with chronic myelogenous leukemia (CML) to compare morphological and clinical features and to evaluate effects of interferon (IFN) and chemotherapy. Following morphometry significant correlations were calculated between number of CD61+ megakaryocytes, including their precursors with fiber density. This finding is in line with the close functional relationship between megakaryopoiesis and fibroblasts regarding the complex pathomechanism of myelofibrosis. The latter was observed in about 28% of patients already at diagnosis. In a similar way, the frequency of CD68+ macrophages was correlated with the amount of Ret40f+ nucleated erythroid precursors, implicating an involvement of this cell lineage in iron turnover, hemoglobin synthesis, and degradation of the expelled nuclei from normoblasts. The (α-D-galactosyl residue-expressing) Pseudo-Gaucher cells were detectable in 30% of pretreatment specimens. Moreover, significant associations were calculable between reduction in erythropoiesis or increase in fibers with clinical features such as hemoglobin level, percentages of myelo- and erythroblasts in the peripheral blood, and spleen size. These variables are in keeping with more advanced stages of CML. Based on our morphometric evaluations, a classification into three different histological subgroups: granulocytic, megakaryocytic, and myelofibrotic was carried out. This simplified staging system was correlated with corresponding sets of hematological data. Sequential biopsies in 173 patients with monotherapy by IFN, hydroxyurea (HU), or busulfan (BU) revealed a fibrogenic effect of IFN in contrast to a fiber-reducing property of HU. The dynamics of myelofibrosis and changes of major cell lineages during treatment were readily demonstrable by calculating corresponding indices. These included the ratios between quantitative differences of corresponding variables at repeated examinations and time. Thus, in patients with complete hematological remission following IFN administration, regeneration of erythropoiesis was found to be accompanied by an increase in the total number of CD68+ macrophages, including activated subpopulations. Histological subgroups showed a transition from a (nonfibrotic) granulocytic and megakaryocyte pattern to the myelofibrotic subtype in about 40% of patients. This change was opposed to a numerical reduction in the myelofibrotic subtype which occurred in 17 patients (36%), but predominantly in those under HU therapy. In conclusion, the striking heterogeneity of bone marrow features in CML warrants a careful morphological evaluation of trephine biopsies and appropriate means of processing to achieve relevant correlations with clinical data and, thus, allows a more elaborate insight into the dynamics of the disease process.
    Notes: Zusammenfassung Bei 604 Patienten mit einer chronischen myeloischen Leukämie (CML) wurde anhand von Beckenkammbiopsien eine immunhistochemische und morphometrische Studie durchgeführt, um morphologische und klinische Befunde miteinander zu vergleichen und die Auswirkungen der Interferon- (IFN) und Chemotherapie abzuklären. Anhand der morphometrischen Analyse konnten signifikante Korrelationen zwischen der Anzahl CD61+-Megakaryozyten einschließlich ihrer Vorläuferzellen mit der Faserdichte berechnet werden. Dieser Befund spiegelt die enge funktionelle Beziehung zwischen der Megakaryopoese und den Fibroblasten im Hinblick auf den komplexen Pathomechanismus der Myelofibroseentstehung wider. Diese war bei etwa 28% der Patienten bereits zum Diagnosezeitpunkt zu beobachten. In ähnlicher Weise war die Anzahl der CD68+-Makrophagen mit der Menge an Ret40f+-kernhaltigen erythropoetischen Vorläuferzellen korreliert, was durch die Einbindung dieser Zellinie in den Eisenstoffwechsel, die Hämoglobinsynthese sowie den Abbau der ausgestoßenen Normoblastenkerne in Zusammenhang gebracht werden kann. Die (α-D-Galaktosylreste-expremierende) Pseudo-Gaucherzellen ließen sich in 30% der Biopsien vor Behandlung nachweisen. Weiterhin konnten signifikante Beziehungen zwischen einer Reduktion der Erythropoese oder einer Zunahme der Verfaserung mit klinischen Parametern wie dem Hämoglobinspiegel, dem Anteil an Myelo- und Erythro-Normoblasten im peripheren Blut und der Milzgröße berechnet werden. Diese Variablen kennzeichnen offensichtlich mehr fortgeschrittene Stadien der CML. Entsprechend unserer morphometrischen Auswertung wurde eine Klassifikation in drei unterschiedliche histologische Subgruppen vorgenommen: granulozytisch, megakaryozytisch und myelofibrotisch. Dieser vereinfachten histologischen Einteilung waren entsprechende hämatologische Daten zuzuordnen. Sequenzbiopsien an 173 Patienten, die eine Monotherapie mit IFN, Hydroxyurea (HU) oder Busulfan (BU) erhielten, zeigten einen fibrogenetischen Effekt von IFN im Gegensatz zu einer eher faserreduzierenden Eigenschaft von HU. Die Dynamik der Myelofibroseentwicklung und die entsprechende Veränderungen der hauptsächlichen Zellinien während der Behandlung ließen sich am besten durch eine Kalkulation von Indizes verdeutlichen. Diese beinhalteten das Verhältnis aus quantitativen Unterschieden der einzelnen Variablen in den wiederholt durchgeführten Entnahmen und den zugeordneten zeitlichen Differenzen. So war bei Patienten mit einer kompletten hämatologischen Remission nach IFN-Gabe die Regeneration der Erythropoese zusammen mit einem Anstieg in der Anzahl CD68+-Makrophagen einschließlich ihrer aktivierten Subpopulation auszumachen. Die histologischen Subgruppen ließen bei fortlaufenden Untersuchungen einen Übergang sowohl von einem (nicht verfaserten) granulozytären wie auch megakaryozytären Subtyp in eine myelofibrotische Gruppe bei etwa 40% der Patienten erkennen. Dieses Phänomen stand im Gegensatz zu einer anzahlmäßigen Reduzierung des myelofibrotischen Typs vor allem bei Patienten unter HU-Therapie in 17 Fällen (36%). Zusammengefaßt erfordert die auffallende Heterogenität der Knochenmarkbefunde bei der CML eine sorgfältige morphologische Auswertung von Biopsien mit geeigneten Methoden, um relevante Korrelationen zwischen klinischen Daten zu berechnen und somit einen besseren Einblick in die Dynamik der Krankheitsentwicklung zu gewinnen.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Der Pathologe 16 (1995), S. 328-335 
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Bronchus-assoziiertes lymphatisches Gewebe ; Marginalzonen ; B-Zell-Lymphome ; Reaktive Keimzentren ; Follikelkolonisation ; Lymphoepitheliale Läsionen ; Key words Bronchus-associated lymphoid tissue ; Marginalzone B-cell lymphoma ; Reactive germinal centers ; Follicular colonisation ; Lymphoepithelial lesions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The malignant B-cell lymphoma of the MALT-type shows significant differences from nodal lymphomas with respect to its biological, molecular genetic, and clinical properties. According to the proposal from the International Lymphoma Study Group for a Revised European-American Classification of Lymphoid Neoplasms, MALT-B-cell lymphomas have been defined as an extranodal subgroup of marginal zone B-cell lymphomas and may have lower and higher grade types. We have applied this classification to 24 cases of primary B-cell lymphomas of the lung. These tumors showed histopathologic features of low (n = 20) and/or high grade neoplasms (n = 4) recapitulating the structure of the acquired bronchus- associated lymphoid tissue (BALT). According to our experience, the diagnosis of BALT-type B-cell lymphoma, is both practically feasable and reproducible not only for surgical material but even for biopsy specimens.
    Notes: Zusammenfassung Maligne B-Zell-Lymphome vom MALT-Typ unterscheiden sich signifikant von nodalen Lymphomen bzgl. ihrer biologischen, molekulargenetischen und klinischen Eigenschaften. Nach den Vorschlägen der Internationalen Lymphom-Studiengruppe für eine revidierte europäisch-amerikanische Klassifikation lymphatischer Neoplasien sind MALT-B-Zell-Lymphome als extranodale Form von Marginalzonen-B-Zell-Lymphomen definiert, die einen niedrigeren oder höheren Malignitätsgrad aufweisen können. Wir wandten dieses Klassifikationskonzept auf 24 Fälle primärer pulmonaler B-Zell-Lymphome an. Alle Fälle zeigten histologische Merkmale niedrigmaligner (n = 20) und/oder hochmaligner Neoplasien (n = 4), die die Struktur des erworbenen bronchusassoziierten lymphatischen Gewebes (BALT) rekapitulierten. Nach unserer Erfahrung, ist die Diagnose von B-Zell-Lymphomen des BALT-Typs nicht allein an chirurgischen Resektaten, sondern auch an Biopsien in der praktischen Diagnostik möglich und reproduzierbar.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 241 (1985), S. 271-278 
    ISSN: 1434-4726
    Keywords: Vocal fold polyps ; Endothelial cell ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Gelatinous and telangiectatic types can be differentiated among the human vocal fold polyps. Telangiectatic polyps are characterized by eosinophilic deposits consisting of fibrin and cellular blood constituents. Labyrinthine vascular channels are characteristic of these polyps, and are partially or completely lined by a single layer of flat cells. Using electron microscopy and immunohistochemical stainings (antibodies against factor VIII-related antigen, Ulex europaeus I lectin, and antibodies against lysozyme), we found that the lining cells are true vascular endothelial cells and are not organizing histiocytic cells that are arranged in an endothelial-like pattern.
    Type of Medium: Electronic Resource
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