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  • 1
    ISSN: 1432-2307
    Keywords: Megakaryocytes ; Sinus wall ; Transmural migration ; 3D-reconstruction ; Double-immunostaining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Using sequential double-immunostaining and a newly-developed three-dimensional (3D-) reconstruction technique on serially cut sections from bone marrow trephines, we studied the transmural passage of megakaryocytes through the sinus wall. Biopsies derived from patients with primary (idiopathic) osteomyelofibrosis were exposed to monoclonal antibody against type IV collagen to delineate the sinus walls and also the frequently thickened basement membrane. Staining with the primary antibody was followed by Y2/51 (CD61) to identify all elements of megakaryopoiesis. In most instances serial sectioning and 3D-reconstruction revealed an amoeboid shape of megakaryocytes and a tandem-like arrangement in close spatial contact with the abluminal surface of the sinus wall. Preceded by formation of cytoplasmic processes, straight penetration of entire megakaryocytes through gaps in the sinus walls into the lumen was seen. Where collagen deposits apparently presented a barrier, a mole-like tunnelling through the basement membrane material (type IV collagen) was recognizable. Our findings are in keeping with the assumption that megakaryocyte locomotion is an essential requirement for normal thrombocytogenesis.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Der Pathologe 16 (1995), S. 128-138 
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Dreidimensionale Rekonstruktion ; Lichtmikroskopie ; Serienschnitte ; Megakaryozyten ; Primäre Osteomyelofibrose ; Knochenmark ; Key words Three-dimensional reconstruction ; Light microscopy ; Serial sections ; Megakaryocytes ; Primary osteomyelofibrosis ; Bone marrow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Computer-based three-dimensional reconstruction of serially cut light microscopic sections is being increasingly used in medical and biological research. Compared with conventional two-dimensional evaluation of histological sections, complex histotopographical relationships and structural details are easy to assess and could be imposingly visualized on the graphics screen. Because of the rapid progress in modern computer hardware, uncomplicated and fast reconstruction systems are available on standard personal computers. Therefore, 3D reconstruction is applicable for a wide range of investigations that warrant 3D exploration. Own results are presented and the principles of 3D reconstruction, as well as the problems and difficulties in this new technique, are discussed. The complex ameboid morphology of megakaryocytes in bone marrow of primary (idiopathic) osteomyelofibrosis is examined with this new method in combination with selective immunohistochemical staining procedures. 3D reconstruction can visualize the complexity of cytoplasmic and nuclear formation impressively. Moreover, the models generated permit exact quantitative measurements of cell morphology. The technique presented is a powerful tool for anatomical-morphological investigations and can furthermore increase our comprehension of complex histomorphological objects.
    Notes: Zusammenfassung Computergestützte dreidimensionale Rekonstruktionsverfahren von lichtmikroskopischen Serienschnitten haben sich in den letzten Jahren in allen Bereichen der medizinisch-biologischen Forschung etablie-ren können. Im Vergleich zur konventionellen zweidimensionalen Schnittbetrachtung lassen sich komplexe histotopographische Beziehungen sowie Strukturcharakteristika besser erfassen und auch eindrucksvoll darstellen. Aufgrund der schnell fortschreitenden Entwicklung im Bereich der Computertechnik sind heutzutage Rekonstruktionssysteme auch auf preisgünstigen Rechnersystemen verfügbar, so daß sich dieser neuen Methode ein zunehmendes Anwendungsgebiet erschließt. Anhand von eigenen Befunden werden die Grundlagen der 3 D-Rekonstruktion besprochen sowie Schwierigkeiten und Probleme dieser neuen Technik diskutiert. In Kombination mit kontrastreichen und selektiven immunhistochemischen Färbungen wird beispielhaft die komplexe amöbenartige Morphologie der Megakaryozyten bei der primären (idiopathischen) Osteomyelofibrose durch lichtmikroskopische Serienschnitte aus dem Knochenmark vorgestellt. Die erzeugten 3 D-Modelle vermitteln einen plastischen Eindruck von der Komplexität der Zell- und Kernstrukturen dieser Zellen und stellen die Basis für exakte quantitative Analysen der Zellmorphologie dar. Die vorgestellte Technik beinhaltet ein ergänzendes Werkzeug für anatomisch-morphologische Analysen und ist in der Lage, entscheidende Erkenntnisse bei der Untersuchung vielschichtiger histomorphologischer Objekte zu liefern.
    Type of Medium: Electronic Resource
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  • 3
    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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  • 4
    ISSN: 1432-0584
    Keywords: Key words Chronic myeloproliferative disorders ; Erythroid precursors ; Neutrophil granulopoiesis ; Megakaryocytes ; Macrophages ; Myelofibrosis ; Enzyme-immunohistochemistry ; Morphometry ; Bone marrow biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The aim of this review is to evaluate morphological characteristics of the different subtypes of chronic myeloproliferative disorders (MPDs) derived by applying immunohistochemical and morphometric techniques to bone marrow biopsies and to combine these results with relevant clinical parameters. In comparison to control specimens, a significant decrease in erythroid precursors is determinable in chronic myeloid leukemia (CML), while this cell lineage is most prominent in polycythemia vera (PV) and moderately to markedly reduced in idiopathic myelofibrosis (IMF). On the other hand, neutrophilic granulopoiesis shows a predominance in CML and a relevant increase in PV, but no conspicuous changes are detectable in essential thrombocythemia (ET). CML is characterized by a prevalent growth of dwarflike micromegakaryocytes, occurring in particular in the so-called megakaryocyte-rich subtypes (about 30%). This finding differs significantly from the pleomorphous aspect, i.e., clusters of small to giant-sized megakaryocytes in PV and the grossly abnormal (dysplastic) appearance of this cell lineage in patients with IMF. Similar cytological abnormalities of megakaryopoiesis consistent with maturation defects are never encountered in ET. The incidence of mature (resident) macrophages (phagocytic reticular cells) is significantly enhanced in IMF in comparison to the other MPDs and controls. Moreover, there is a striking difference in the density of reticulin-collagen fibers, ranging from normal (ET) to extreme values (IMF). In IMF more than 80% of the patients present with some degree of myelofibrosis-osteosclerosis at diagnosis, while the rest show an initial prefibrotic, hypercellular stage. This feature deserves special attention since, when accompanied by thrombocythemia, it may simulate ET. Sequential bone marrow biopsies in patients with IMF disclose that evolution of myelofibrosis is progressive, but occurs at a variable and unpredictable speed. A synoptical approach regarding clinical diagnosis and histological subtyping of MPDs is explicitly recommended and demonstrated by sets of diagnostic criteria. This rationale requires equal consideration of laboratory data and morphology by clinicians to include well-defined subtypes of MPDs into prospective management studies. Furthermore, it may even warrant follow-up studies and repeated bone marrow examinations in initially unclassifiable cases.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0584
    Keywords: CML ; Myelofibrosis ; Dynamics ; Megakaryocytes ; Morphometry ; Interferon ; Busulfan ; Sequential bone marrow biopsies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To evaluate treatment-related changes of the reticulin stain-measured fibrosis in Ph1+-CML, a clinicopathological study was performed on sequential trephine biopsies of the bone marrow following either interferon (IFN) or busulfan (BU) monotherapy. Using the monoclonal antibody CD61 for the identification of megakaryopoiesis and Gomori's silver impregnation method, number of megakaryocytes and density of argyrophilic (reticulin and collagen) fibers were determined by morphometry. We studied specimens from 26 patients with IFN-alpha 2b (including nine patients with additional IFN gamma) therapy and from 23 patients who had received BU. In both groups, repeated bone marrow biopsies (total 125) revealed a significant increase in the fiber content, as well as in the number of megakaryocytes during treatment. To assess the dynamics of myelofibrosis more precisely, computation of differences in the degree of fiber density between the first and last examination was carried out. Regarding the considerable variations in the biopsy intervals, a so-called myelofibrosis progression index (MPI) was calculated. Following this rationale, we were able to demonstrate that, in comparison to the BU-group, speed of progression of bone marrow fibrosis was significantly increased in CML patients treated with IFN. Preliminary statistical analysis indicated a relationship between myelofibrosis on admission, which was always associated with increased growth of megakaryocytes, and the MPI with survival. Even when these parameters were regarded, prognosis was significantly more favorable in the IFN-treated patients. The failure of IFN and BU to inhibit the evolution of myelofibrosis may be related to several conversely acting pathomechanisms. Among others, the inability of both therapeutic agents to reduce the number of megakaryocytes more effectively should be taken into consideration.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-0584
    Keywords: Key words CML ; Myelofibrosis ; Dynamics ; Megakaryocytes ; Morphometry ; Interferon ; Busulfan ; Sequential bone marrow biopsies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  To evaluate treatment-related changes of the reticulin stain-measured fibrosis in Ph1+-CML, a clinicopathological study was performed on sequential trephine biopsies of the bone marrow following either interferon (IFN) or busulfan (BU) monotherapy. Using the monoclonal antibody CD61 for the identification of megakaryopoiesis and Gomori's silver impregnation method, number of megakaryocytes and density of argyrophilic (reticulin and collagen) fibers were determined by morphometry. We studied specimens from 26 patients with IFN-alpha 2b (including nine patients with additional IFN gamma) therapy and from 23 patients who had received BU. In both groups, repeated bone marrow biopsies (total 125) revealed a significant increase in the fiber content, as well as in the number of megakaryocytes during treatment. To assess the dynamics of myelofibrosis more precisely, computation of differences in the degree of fiber density between the first and last examination was carried out. Regarding the considerable variations in the biopsy intervals, a so-called myelofibrosis progression index (MPI) was calculated. Following this rationale, we were able to demonstrate that, in comparison to the BU-group, speed of progression of bone marrow fibrosis was significantly increased in CML patients treated with IFN. Preliminary statistical analysis indicated a relationship between myelofibrosis on admission, which was always associated with increased growth of megakaryocytes, and the MPI with survival. Even when these parameters were regarded, prognosis was significantly more favorable in the IFN-treated patients. The failure of IFN and BU to inhibit the evolution of myelofibrosis may be related to several conversely acting pathomechanisms. Among others, the inability of both therapeutic agents to reduce the number of megakaryocytes more effectively should be taken into consideration.
    Type of Medium: Electronic Resource
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