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  • 1
    Electronic Resource
    Electronic Resource
    Licht- und elektronenmikroskopische Untersuchungen an den peritubulären Zellen des Schweinehodens während der postnatalen Entwicklung (1973)
    Springer
    Anatomy and embryology 143 (1973), S. 49-64 
    Details
    ISSN: 1432-0568
    Keywords: Testicular peritubular cells ; Boar ; Postnatal development ; Ultrastructure ; Contractility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Membrana propria der Hodentubuli des Schweines zeigt einen deutlichen Schichtenbau: Auf die Basalmembran des Tubulusepithels (a) folgen eine nicht-celluläre Lage mit Kollagenfibrillen (b), die von einer inneren (c) und einer äußeren (e) Basalmembran umhüllten peritubulären Zellen (d) und dann das intertubuläre lockere Bindegewebe (f). Die ausdifferenzierten peritubulären Zellen haben viele morphologische Merkmale mit glatten Muskelzellen gemeinsam. So besitzen sie Plasmalemmeinbuchtungen in Form pinocytotischer Bläschen sowie eine große Anzahl von Filamenten mit einem Durchmesser von 60–70 Å, welche über elektronendichte Strukturen an der Innenseite des Plasmalemms befestigt sind. Ein Golgi-Apparat, rauhes endoplasmatisches Reticulum, Mitochondrien und Mikrotubuli bevorzugen eine kernnahe Position. Im Gegensatz zu den Verhältnissen bei anderen Species sind viele charakteristische Eigenschaften der peritubulären Zellen schon vor der Pubertät ausgebildet. Die Filamente können bereits am 4. Tag als feines Netzwerk beobachtet werden, sie erfahren am 25. Tag eine starke Vermehrung und sind von nun an regelmäßig orientiert. Auch andere Befunde sprechen dafür, daß die peritubulären Zellen um den 25. Tag eine gesteigerte Aktivität entfalten. Die histochemisch nachgewiesenen Konzentrationen von alkalischer Phosphatase, Adenosintriphosphatase und Glucose-6-phosphatase erreichen zu diesem Zeitpunkt die hohen Werte, die auch für die weitere Entwicklungsphase und die ausdifferenzierten peritubulären Zellen typisch sind. Pinocytotische Bläschen erscheinen in größerer Anzahl ab dem 97. Tag. Mit dem 140. Tag sind die peritubulären Zellen morphologisch ausdiffrenziert.
    Notes: Summary The boundary tissue of the porcine testicular seminiferous tubule (membrana propria) exhibits a distinct stratification: the basement lamina of the tubular epithelium (a) is followed by a non-cellular layer with collagen fibrils (b), the peritubular cells (d) with an inner (c) and outer (e) basement lamina and finally the intertubular loose connective tissue (f). Fully developed peritubular cells have many morphological features in common with smooth muscle cells, for instance inpocketings of the plasmalemma (pinocytotic vesicles) and a great number of filaments measuring 60–70 Å in diameter. These filaments are fixed at the inner side of the plasmalemma by means of electron-dense structures. The Golgi apparatus, rough endoplasmic reticulum, mitochondria and microtubules prefer a juxtanuclear position. In contrast that is seen in other species the porcine peritubular cells develop many of their characteristic features before puberty. In samples of the 4th day a fine network of filaments is already visible within the cytoplasm. These filaments are strongly augmented at the 25th day, and from now on they are arranged in a regular fashion. Other findings, also, underline an increased activity of the peritubular cells around day 25. At that time the concentrations of histochemically demonstrated alkaline phosphatase, adenosine triphosphatase and glucose-6-phosphatase reach the high levels typical for the stages of further development and the fully differentiated cells. Pinocytotic vesicles appear in great numbers from day 97. At the 140th day the morphology of the porcine peritubular cell is completely developed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00519910
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  • 2
    Electronic Resource
    Electronic Resource
    Extramembraneous particles and structural variations of tubular myelin figures in rat lung surfactant
    Amsterdam : Elsevier
    Journal of Ultrasructure Research 86 (1984), S. 57-66 
    Details
    ISSN: 0022-5320
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0022-5320(84)90095-9
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  • 3
    Electronic Resource
    Electronic Resource
    3D reconstruction of serial sections of blood platelets by a personal computer
    Amsterdam : Elsevier
    Cell Biology International Reports 14 (1990), S. 215 
    Details
    ISSN: 0309-1651
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0309-1651(90)90961-W
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  • 4
    Electronic Resource
    Electronic Resource
    Methods of heavy metal electron microscopic histochemistry applied to frog lung surfactant (1979)
    Springer
    Histochemistry and cell biology 61 (1979), S. 199-212 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Four heavy metal staining methods have been applied to frog lung surfactant. Among them, the iodoplatinate method is the only one that almost exclusively visualizes the phospholipid moiety being produced in the lamellated bodies of the pulmonary epithelial cells and forming the backbone of organized structures within the extracellular lining layer. The other three techniques — ruthenium red-osmium tetroxide, osmium tetroxideferrocyanide, acidic phosphotungstic acid in chromate (Rambourg technique) — more or less give electron contrast to glycoproteins and to a lesser extent to the hydrophilic parts of phospholipids. They all show the extracellular lining layer to be a two component system: the content of the lamellar bodies from — when released — membranous configurations, similar to those observed in mammalian lungs; they unfold in an amorphous hypophase, which is apparently secreted by goblet cells of the pulmonary epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00496532
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  • 5
    Electronic Resource
    Electronic Resource
    Enzymhistochemische Untersuchungen an den Leydigzellen des Schweines während der postnatalen Ontogenese (1973)
    Springer
    Histochemistry and cell biology 36 (1973), S. 321-333 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die postnatale Ontogenese der Hodenzwischenzellen des Schweines nimmt einen wellenförmigen Verlauf und läßt sich in folgende 4 Phasen unterteilen: Frühpostnatale Proliferation, präpubertäre Hypertrophie, präpubertäre Regression und pubertäre Proliferation. Die mitochondrial lokalisierten Enzyme ICDH, SDH, Cyt-Ox, die in der cytoplasmatischen Matrix untergebrachte 6-PGDH, die an das glatte endoplasmatische Retikulum gebundene 3β-HStDH sowie die β-D-Glucuronidase zeigen im Prinzip ein gleiches Verhalten: Zunehmende Aktivität in der frühpostnatalen Proliferation, maximale Konzentration während der präpubertären Hypertrophie, Aktivitätsrückgang während der präpubertären Regression und erneuter Aktivitätsanstieg in der pubertären Proliferation. Dieses Enzymmuster macht es wahrscheinlich, daß die Zwischenzellen des Schweinehodens zum Zeitpunkt der präpubertären Hypertrophie Sexualsteroide synthetisieren und abgeben. Die LDH aus der Glycolysekette bleibt im gesamten Untersuchungszeitraum auf einem mittelgradigen Niveau konstant, und dieser Stoffwechselweg dürfte während der präpubertären Regression die wichtigste Energiequelle der Zwischenzellen sein. ATP'ase und alk. P'ase sind die einzigen Enzyme, welche während der präpubertären Regression eine Aktivitätssteigerung in den Zwischenzellen erkennen lassen.
    Notes: Summary The postnatal development of porcine testicular interstitial cells proceeds in a wavelike manner and may be divided into the following 4 periods: Early postnatal proliferation, prepubertal hypertrophy, prepubertal regression and pubertal proliferation. ICDH, SDH, Cyt-Ox (localized in the mitochondria), 6-PGDH (localized within the cytoplasmic matrix), 3β-HStDH (localized in the smooth endoplasmic reticulum) and β-D-glucuronidase exhibit an essentially identical distribution pattern: increasing activity during early postnatal proliferation, a maximum during prepubertal hypertrophy, decreasing activity during prepubertal regression and a second increase during pubertal proliferation period. This typical enzymatic pattern can be taken for evidence that porcine testicular interstitial cells of prepubertal hypertrophy period are capable to synthesize and deliver sexual steroids. LDH of the glycolytic chain reveals moderate activity levels throughout the whole postnatal development; glycolytic reactions, therefore, seem to be the main source of energy during the prepubertal regression period. ATP'ase and alkaline phosphatase are the only enzymes which show increasing concentrations during prepubertal regression of the interstitial tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305711
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  • 6
    Electronic Resource
    Electronic Resource
    Ultrahistochemical investigations of dog lung surfactant with ruthenium red and iodoplatinate reactions (1979)
    Springer
    Histochemistry and cell biology 60 (1979), S. 335-346 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dog lungs have been fixed by immersion and submitted to two histochemical procedures. An iodoplatinate reaction technique to demonstrate choline phospholipids stains cell membranes, inclusion bodies of type II alveolar epithelial cells and tubular myelin figures of pulmonary surfactant, the latter as electron-dense lines measuring 5 nm. The ruthenium red procedure gives rise to an intense contrast of the free surface of alveolar epithelium. The 5 nm-lines of the pulmonary surfactant are seen as electron-lucent lines, but bordered by electron-dense rims. Though both techniques have limitations in their interpretation, which are discussed in this paper, they demonstrate the tubular myelin figures to be a highly organized mixture of phospholipids and glycoproteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500662
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  • 7
    Electronic Resource
    Electronic Resource
    Lipid extracting properties of 2,2-dimethoxypropane as revealed by electron microscopy and thin layer chromatography (1982)
    Springer
    Histochemistry and cell biology 76 (1982), S. 407-412 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dehydration with 2,2-dimethoxypropane acidified with either 1 N HCL or 0.05 N HCL in an 1:100 ratio has been found to extract various biologically active lipids. The effect is enhanced by an increased proton concentration and seems to occur only after complete H2O transformation. It is suggested that lipid extraction is caused by a reoxidation of lower osmium oxides with subsequent attack on the unfixed lipids by the organic solvent DMP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00543960
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  • 8
    Electronic Resource
    Electronic Resource
    Ruthenium red as a stain for electron microscopy. Some new aspects of its application and mode of action (1979)
    Springer
    Histochemistry and cell biology 64 (1979), S. 171-187 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Commercial ruthenium red has been tested for its purity by spectrophotometry. Impurities detected by this method could be abolished by nitric acid-precipitation of ruthenium brown. This substance has no effect on cell surface staining and converts almost completely to ruthenium red under the conditions used in electron microscopy. It was found, by photometric analysis, that in the ruthenium red-osmium tetroxide-cacodylate combination, generally used for cell surface staining, chemical reactions between ruthenium red and osmium tetroxide occur. As aerial oxidation of hexammineruthenium2+ leads to a product with some surface staining capability, it is suggested that an oxidazed product of ruthenium red is responsible for binding to cellular components, and that a reduced product of osmium tetroxide gives an additional contrast enhancement. In ruthenium red-osmium dioxide combinations ruthenium red seems to bind to cell surfaces without any molecular alteration, and contrast is gained by the model proposed by Blanquet (1976b). The latter method could open a way for investigating the binding of ruthenium red to certain natural compounds involved in calcium transport, as postulated by a number of authors. Both ruthenium-osmium combinations differ in their cell surface staining ability. The ruthenium red-osmium dioxide combination tends to form distinct subunits, whereas the osmium tetroxide variety stains homogeneously. In combination with osmium dioxide, the surface staining is affected by EDTA, and, in contrast to osmium tetroxide, a successive application of ruthenium red and osmium dioxide as possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00490097
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  • 9
    Electronic Resource
    Electronic Resource
    Problems of the use of 2,2-dimethoxypropane as dehydrating agent in preparing single cells for transmission electron microscopy (1982)
    Springer
    Histochemistry and cell biology 74 (1982), S. 263-269 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dehydration with 2,2-dimethoxypropane acidified with 1 n HCl in an 1:100 volume ratio has been found to be insuitable for the preservation of cell membranes in single cell preparations. Reducing the HCl concentration to 0.1 or 0.01 n results in an improvement of membrane structures. This effect is rather independent of different fixation modes, buffer concentrations, or embedding media. It is suggested that membrane destruction is caused by a proton concentration exceeding a suitable level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00495835
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  • 10
    Electronic Resource
    Electronic Resource
    Outgrowing nerves in the foreleg of a mouse embryo as viewed by three-dimensional reconstruction from electron micrographs (1995)
    Springer
    Cell & tissue research 280 (1995), S. 197-199 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Innervation ; Axon ; Schwann cell ; Differentiation ; Three-dimensional Reconstruction ; Mouse-embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Electron micrographs from serial cross-sections of 12-day-old mouse forelegs were digitized and three-dimensional reconstruction of the data was carried out on an Apple Macintosh Quadra 700 computer using a program especially designed for this purpose. Two nerve endings of the palmar net of the median nerve were visualized together with their accompanying Schwann cells and the surrounding processes of fibroblasts. Naked axons invade straightly into the embryonic connective tissue and serve as contact guidance for the Schwann cells to follow. Fibroblasts with long processes extend around the axons with a parallel orientation. Contacts between axons and fibroblasts are occasionally observed. It is unclear whether the parallel orientation of nerve endings and fibroblast extensions have any biological significance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304525
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