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  • Immunohistochemistry  (2)
  • *Magnetic Fields  (1)
  • 1
    ISSN: 1432-1963
    Keywords: Schlüsselwörter bcl-2 ; Osteosarkom ; Apoptose ; programmierter Zelltod ; Immunhistologie ; Proliferation ; Key words bcl-2 ; Osteosarcoma ; Apoptosis ; programmed cell death ; Immunohistochemistry ; Proliferation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The relationsship between the growth of tumors and the expression of the protooncogen Bcl-2 could be shown in epithelial tumors. A bcl-2 expression leads to a prolonged cell survival due to an inhibition of apoptosis. The potential meaning of bcl-2 expression in mesenchymal tumors remains still unknown. The fact, that the heterogenous group of osteosarkoma is not sufficiently characterized at present, suggested to investigate the bcl-2 expression in osteosarcoma. Thus, immunohistochemistry was used to analyze 47 specimens of different osteosarcomas of 36 patients. Sixteen cases (46 %) showed a strong expression of bcl-2 and 13 cases (35 %) were moderately positiv for bcl-2. Seven cases (19 %) were negative for bcl-2. The heterogenous, negative up to strong expression of bcl-2 yield clues, that the Bcl-2 controlled regulation of programmed cell death could be an important factor of cellular kinetics. Additionally the cellular proliferationrate was determined with the monoklonal antibody MIB 1, directed against the Ki-67 epitop. The data of bcl-2 expression and cellular proliferationrate lead to a classification correlating with the histological classification. To verify the importance of apoptosis in the genesis of mesenchymal tumors and whether Bcl-2 may play an important role as a predictive factor for the prognosis of osteosarcoma, further investigations will be needed.
    Notes: Zusammenfassung Bei zahlreichen epithelialen Geweben konnte ein Zusammenhang zwischen Tumorwachstum und der Expression des Protoonkogens Bcl-2 nachgewiesen werden. Eine bcl-2-Expression ist verbunden mit verlängertem Zellüberleben infolge einer Apoptoseinhibition. Hingegen ist über die bcl-2-Expression und deren mögliche Bedeutung in mesenchymalen Tumoren wenig bekannt. Da die heterogene Gruppe der Osteosarkome mit den derzeitigen methodischen Mitteln nicht hinreichend charakterisierbar ist, wurde die bcl-2-Expression untersucht. Immunhistologisch wurden 47 Osteosarkompräparate von 36 Patienten unterschiedlicher Subtypen analysiert. Von den 36 Fällen zeigten in der Biopsie 16 Fälle (46 %) eine stark positive und 13 Fälle (35 %) eine mittelgradig positive bcl-2 Expression. Sieben Fälle (19 %) waren bcl-2-negativ. Die heterogene, fehlende bis starke bcl-2-Expression deutet darauf hin, daß in Osteosarkomen die Bcl-2-gesteuerte Regulation des programmierten Zelltodes einen Faktor in der zellulären Wachstumskinetik darstellt. Zusätzlich wurde die Proliferationsrate, anhand des gegen das Ki-67-Antigen gerichteten monoklonalen Antikörper MIB-1 bestimmt. Aus den Daten zur bcl-2-Expression und Proliferationsrate ergibt sich eine Einteilung, die eine Übereinstimmung mit der histologischen Klassifikation aufweist. Welche Bedeutung die Apoptose in der Genese mesenchymaler Tumoren hat und ob die bcl-2-Expression einen prädiktiven Wert für die Prognose von Osteosarkomen besitzt, bedarf weiterer Untersuchungen.
    Type of Medium: Electronic Resource
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  • 2
    Publication Date: 2012-04-13
    Description: Understanding the molecular and cellular mechanisms that mediate magnetosensation in vertebrates is a formidable scientific problem. One hypothesis is that magnetic information is transduced into neuronal impulses by using a magnetite-based magnetoreceptor. Previous studies claim to have identified a magnetic sense system in the pigeon, common to avian species, which consists of magnetite-containing trigeminal afferents located at six specific loci in the rostral subepidermis of the beak. These studies have been widely accepted in the field and heavily relied upon by both behavioural biologists and physicists. Here we show that clusters of iron-rich cells in the rostro-medial upper beak of the pigeon Columbia livia are macrophages, not magnetosensitive neurons. Our systematic characterization of the pigeon upper beak identified iron-rich cells in the stratum laxum of the subepidermis, the basal region of the respiratory epithelium and the apex of feather follicles. Using a three-dimensional blueprint of the pigeon beak created by magnetic resonance imaging and computed tomography, we mapped the location of iron-rich cells, revealing unexpected variation in their distribution and number--an observation that is inconsistent with a role in magnetic sensation. Ultrastructure analysis of these cells, which are not unique to the beak, showed that their subcellular architecture includes ferritin-like granules, siderosomes, haemosiderin and filopodia, characteristics of iron-rich macrophages. Our conclusion that these cells are macrophages and not magnetosensitive neurons is supported by immunohistological studies showing co-localization with the antigen-presenting molecule major histocompatibility complex class II. Our work necessitates a renewed search for the true magnetite-dependent magnetoreceptor in birds.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Treiber, Christoph Daniel -- Salzer, Marion Claudia -- Riegler, Johannes -- Edelman, Nathaniel -- Sugar, Cristina -- Breuss, Martin -- Pichler, Paul -- Cadiou, Herve -- Saunders, Martin -- Lythgoe, Mark -- Shaw, Jeremy -- Keays, David Anthony -- England -- Nature. 2012 Apr 11;484(7394):367-70. doi: 10.1038/nature11046.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Molecular Pathology, Dr Bohr-Gasse, 1030 Vienna, Austria.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="" target="_blank"〉PubMed〈/a〉
    Keywords: Animal Migration ; Animals ; Beak/anatomy & histology/*cytology ; Columbidae/*anatomy & histology/physiology ; Feathers/cytology/ultrastructure ; Ferrocyanides/analysis ; Immunohistochemistry ; Iron/analysis/*metabolism ; Macrophages/*metabolism/ultrastructure ; *Magnetic Fields ; Magnetic Resonance Imaging ; Neurons/metabolism ; Orientation ; Respiratory Mucosa/cytology/ultrastructure ; *Sensation ; Tomography, Emission-Computed, Single-Photon
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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