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  • Ultrastructure  (27)
  • Springer  (27)
  • Institute of Physics
  • National Academy of Sciences
  • 2010-2014
  • 1970-1974  (27)
  • 1
    Electronic Resource
    Electronic Resource
    Specific apocrine secretion in the anterior lobe of the prostate gland of rabbits (1974)
    Springer
    Cell & tissue research 151 (1974), S. 69-77 
    Details
    ISSN: 1432-0878
    Keywords: Prostate (rabbit) ; Anterior lobe ; Apocrine secretion ; Ultrastructure ; Protein secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of glandular cells in the anterior lobe of the rabbit prostate was reinvestigated, especially after fixation by vascular perfusion with glutaraldehyde. The lumina of the gland contain abundant globules of an amorphous material surrounded by a membrane. A few dense bodies and scattered globules with internal vesicles also occur. These luminar contents obviously correspond to the particles observed in the semen of rabbits. Strong evidence was found for the formation of the globules by an apocrine secretory process. Material similar to the contents of the luminar globules accumulates in the cell apex together with vesicles, probably of Golgi origin, but without any other organelles. Protrusions from the cell surface contain similar material, but the vesicles generally disappear before the forming globule is finally pinched off from the cell surface. The characteristic feature of the secretory cell are the paucity of endoplasmic reticulum and the large amounts of ribosomes. This is interpreted as a specialization of the cell for the production of secretory protein that is not segregated within membranes until it is discharged from the cell by apocrine secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222035
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  • 2
    Electronic Resource
    Electronic Resource
    Observations on the mode of uptake of thorium dioxide particles by osteoclasts in fracture callus (1972)
    Springer
    Calcified tissue international 10 (1972), S. 216-222 
    Details
    ISSN: 1432-0827
    Keywords: Ultrastructure ; Callus ; Osteoclast ; Endocytosis ; Lysosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La bordure en brosse des ostéoclastes de cals de fractures de rats présente des plissements complexes de la membrane cytoplasmique formant des canaux étroits. L'absorption d'un produit exogène opaque aux électrons (des macromolécules de dioxyde de thorium) s'effectue par l'intermédiaire de ces canaux, par un «courant» membranaire. Les contenus des canaux sont transférés à des lysosomes («granules spécifiques»), situés sous la bordure en brosse. Dans des «régions de transition», adjacentes à cette dernière, l'absorption de dioxyde de thorium se fait par «vésiculation membranaire» (endocytose classique).
    Abstract: Zusammenfassung Der gekrauste Rand der Osteoklasten im Frakturcallus von Ratten besteht aus komplexen Einstülpungen der Plasmamembran, die enge Kanälchen bildet. Die Absorption einer exogenen, elektronisch dichten Verbindung, Thoriumdioxyd, erfolgt durch diese Kanäle, offenbar durch einen „Membranfluß”. Der Inhalt der Kanäle wird zu den Lysosomen („spezifische Granula”) geführt, welche unter dem gekrausten Rand liegen. In „Übergangsgebieten”, welche sich neben dem gekrausten Rand befinden, scheint die Aufnahme der Thoriumdioxydpartikel durch „Bläschenbildung in der Membran” (konventionelle Endocytose) stattzufinden.
    Notes: Abstract The ruffled border of osteoclasts in the fracture callus of rat consists of complex infoldings of the plasma membrane forming narrow channels. Absorption of an exogenous, electron-dense compound, thorium dioxide, has been shown to take place via these channels, apparently through “membrane flow”. The contents of the channels are transferred to lysosomes (“specific granules”) located subjacent to the ruffled border. In “transitional regions” adjacent to the ruffled border, uptake of thorium dioxide particles appeared to occur through “membrane vesiculation” (conventional endocytosis).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012551
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructural aspects of the marine fungusJaponochytrium sp. (1974)
    Springer
    Archives of microbiology 96 (1974), S. 305-317 
    Details
    ISSN: 1432-072X
    Keywords: Marine Fungi ; Ultrastructure ; Multilamellate Sporangial Wall ; Sagenogenetosome ; Zoospore Cleavage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The morphology and ultrastructure of aJaponochytrium sp. has been studied by light, scanning and transmission electron microscopy. The wall has been shown to be multilamellate and persistent. Stages in zoospore cleavage are described and sagenogenetosomes reported in mature sporangia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00590186
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  • 4
    Electronic Resource
    Electronic Resource
    Comparative structural characterization of material extractable from aerial sheath of Streptomyces roseoflavus var. roseofungini (1974)
    Springer
    Archives of microbiology 101 (1974), S. 71-82 
    Details
    ISSN: 1432-072X
    Keywords: Streptomycetes ; Ultrastructure ; Surface Sheath
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Tubular-like structures were regularly revealed in the surface sheath of the aerial mycelium of the parent strain of Streptomycetes roseoflavus var. roseofungini. In their shape and dimensions these structures were highly reminiscent of those massive accumulation of which was earlier reported to occur in cultures of dedifferentiated nocardioform “fructose” mutant of the same parent strain. 2. The tubular-like structures of the aerial mycelium sheath were shown to be markedly susceptible to brief acetone washing, undergoing almost complete desintegration. 3. On addition of water to crude acetone extract of the aerial mycelium precipitation and possible selfassembly of a spectrum of various structures occurred (folded scaly, bubble-like, spout-like). Some among structures so produced were reminiscent of those found in spectra of structures observed in reconstruction experiments with tubules from the mutant as well as of structures found in the aerial sheath of the parent strain and some other actinomycetes. Similarity in subunit structure of above materials was also noticeable. The presence, in the sheath of aerial mycelium, of material with a tendency to selforganization is discussed in relation to the possible involvement of selfassembly processes in the formation of the surface sheath.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00455926
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  • 5
    Electronic Resource
    Electronic Resource
    The ultrastructure of nuclear division in a suctorian, Tokophrya infusionum (1971)
    Springer
    Cell & tissue research 115 (1971), S. 149-164 
    Details
    ISSN: 1432-0878
    Keywords: Nuclear division ; Protozoan ; Ultrastructure ; Microtubules ; Colchicine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes in the micro- and macronucleus throughout division were followed in synchronized cultures of the suctorian, Tokophrya infusionum. After an initial swelling, the micronucleus elongates enormously; microtubules within the micronucleus proliferate and lengthen as the micronucleus elongates. Changes in the macronucleus become visible only after micronuclear division is well underway. The chromatin bodies fuse into long chromatin strands, and the large bundles of microtubules present in the resting macronucleus break up into small groups which parallel the chromatin strands. Colchicine, which prevents reproduction in Tokophrya, seems to block division at a very early stage. The macronucleus appears the same as the resting nucleus of untreated organisms, with numerous microtubules and distinct chromatin bodies. The chromatin in the micronucleus aggregates into large clumps, however, and proliferation of microtubules does not occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00391122
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  • 6
    Electronic Resource
    Electronic Resource
    Elektronenmikroskopische Untersuchungen an menschlichen Leukozyten nach Osmium-Zink-Imprägnation (1971)
    Springer
    Cell & tissue research 121 (1971), S. 358-376 
    Details
    ISSN: 1432-0878
    Keywords: Leukocyte ; Peripheral ; Human ; Ultrastructure ; Osmium-Zinc-Impregnation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Leukozytenkonzentrate des peripheren Blutes von gesunden Versuchs-personen wurden in 2,5%iger Glutaraldehyd-Lösung (0,1 M Na-Cacodylat-Puffer, pH 7,3) vorfixiert und nach der Methode von Maillet (1959) mit OsO4 + ZnJ2 inkubiert. Dickschnitte wurden mit dem Mikroanalysator (Siemens) auf ihren Gehalt an Osmium, Zink und Jod analysiert und die Dünnschnitte mit dem Elektronenmikroskop untersucht. Bei der Mikroanalyse ließen sich Osmium und Zink, nicht aber Jod nachweisen. Die elektronenmikroskopischen Untersuchungen ergaben folgende Resultate: Beträgt der pH-Wert der Inkubationslösung 5,6, so findet sich eine starke Os/Zn-Imprägnation des Golgi-Apparates, des Kernspaltes und des Endoplasmatischen Retikulums bei sämtlichen Arten der weißen Blutzellen. Die Matrix der Mitochondrien dieser Zellen ist im allgemeinen weniger stark imprägniert. Auch in den Lysosomen der Monozyten und Plasmazellen sind geringfügige Os/Zn-Präzipitate nachweisbar. Es findet keine Reaktion in den Leukozytengranula und in den Zentriolen statt. Dagegen zeigen die Lipidtropfen der eosinophilen Granulozyten eine sehr starke, homogene Os/Zn-Imprägnation. Diese ist bereits nach 40 min Inkubation voll ausgeprägt. Bei einer Schnittkontrastierung mit Uranylacetat werden die Os/Zn-Präzipitate wieder herausgelöst, wenn die Kontrastierung länger als 2 min dauert. Eine Bleikontrastierung hat keinen Einfluß auf die Os/Zn-Präzipitate. Bei Erhöhung des pH-Wertes der Inkubationslösung auf 6,2 kommt es zur starken Imprägnation des Externums der eosinophilen Granula, während Kernspalt, Golgi-Apparat und Mitochondrienmatrix keine Reaktion zeigen. Die Imprägnationsdichte der Lipidtropfen der eosinophilen Granulozyten ist pH-unabhängig.
    Notes: Summary “Buffy coats” of normal human peripheral blood were fixed in 2.5% glutaraldehyde (buffered with 0.1 M Na-cacodylate, pH 7.3) and incubated with a mixture of osmium tetroxide and zinc iodide (pH 5.2) after the method of Maillet (1959). Utilizing an electron probe microanalyser (Siemens), the authors demonstrated the presence of osmium and zinc in the specimen, whereas the presence of iodide could not be proved with certainty. The ratio of osmium and zinc in the precipitates ranges from 3/2 to 4/1. Electron microscopic studies of the leukocytes have lead to the following results: the Golgi apparatus, the perinuclear cleft and the endoplasmic reticulum (ER) of all types of leukocytes are strongly impregnated with osmium/zinc, whereas the matrices of the mitochondria are less impregnated. Osmium/zinc precipitates have also been detected in the lysosomes of monocytes and plasma cells. No reaction was evident in the leukocytic granules or centrioles. The presence of lipid droplets in eosinophils has been demonstrated. These droplets show a dense homogeneous osmium/zinc impregnation which reaches its maximum after 40 minutes of incubation, compared with much longer incubation times (5–6 hours) for other cellular components. Setting the pH of the osmium tetroxide-zinc iodide solution to 6.2 resulted in a dense impregnation of the “externum” of the eosinophilic granules. At this same pH, the perinuclear cleft, Golgi apparatus and mitochondrial matrix did not show a definite reaction. The extent of impregnation of the lipid droplets of the eosinophils showed no dependency on pH. Care must be taken when a stain containing uranyl acetate is used since this substance dissolves the Os/Zn precipitates. Exposure of the precipitates to the uranyl acetate for longer than 2 minutes results in gradual dissolution within complete dissolution in 10 minutes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00337639
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  • 7
    Electronic Resource
    Electronic Resource
    Intercellular bridges and division patterns of rat spermatogonia (1972)
    Springer
    Cell & tissue research 127 (1972), S. 201-208 
    Details
    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Rat ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pattern of intercellular cytoplasmic bridges between rat spermatogonia and between spermatocytes is illustrated from electron microscopy of serial sections. Clones, or syncytia, containing as many as 22 connected spermatogonia and as many as 74 connected spermatocytes were observed. The absence of closed rings of cells agrees with the observation that intercellular bridges are the result of incomplete cell division, rather than cell fusion. The bridges thus are a record of spermatogonial divisions within a clone. In early spermatogonial generations there is a predominantly linear arrangement. The groups of spermatocytes have more side branches. From the presence of synaptonemal complexes it is concluded that the connected spermatocytes of a given clone are in about the same developmental stage. The pattern of intercellular bridges indicates, however, that not all nuclei in a clone undergo mitosis in the same cycle. The connected cells of a clone are therefore not all of the same generation. From unconnected bridges it is assumed that new clones originate from single cells or groups of spermatogonia which separate from an existing clone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306802
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  • 8
    Electronic Resource
    Electronic Resource
    The hypothalamo-hypophysial system in acipenseridae (1973)
    Springer
    Cell & tissue research 136 (1973), S. 461-477 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Acipenseridae ; Neurosecretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neurohypophysis of sexually mature male and female Acipenser güldenstädti Brandt and Acipenser stellatus Pallas was studied light and electron microscopically. The recessus hypophysei lined with ependymal cells of two main types, “narrow” and “wide”, are in the center of the neurohypophysial “roots”. Processes from both cell types run radially to the basement membrane of the connective tissue layers abutting on the hypophysial intermediate lobe. Protrusions penetrating deep into the recessus hypophyseus are found in the apical parts of the “wide” cells. Pituicytes are rare in the neurohypophysis. The ultrastructure of both ependymal cell types and of the pituicytes is described. Nonmyelinated “Gomori-positive” (peptidergic) neurosecretory A1 and A2 type fibres and their terminals containing elementary neurosecretory granules (1400–1800 Å and 1000–1400 Å respectively) are the main structural elements of the neurohypophysis. Some “dark” and single myelinated neurosecretory fibres have been found. The adrenergic fibres (type B) were described earlier (Polenov et al., 1972a). The structural peculiarities of the neurohypophysis are discussed in functional and comparative-morphological terms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307364
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  • 9
    Electronic Resource
    Electronic Resource
    Fine structure of eyespots in tornarian larvae (Phylum: Hemichordata) (1973)
    Springer
    Cell & tissue research 142 (1973), S. 89-102 
    Details
    ISSN: 1432-0878
    Keywords: Photoreceptors ; Larva ; Hemichordate ; Ultrastructure ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The eyespots of tornariae of enteropneusts (Ptychodera flava from Hawaiian waters and an unknown species from southern California) were studied by electron microscopy. An ocellus is composed of two types of cells: sensory and supportive. The former is characterized by a bulbous cilium (with 9+2 axoneme) at its distal end, one or sometimes two arrays of microvilli from its sides below the cilium, and a basal axon. The latter features large, clear vesicles which presumably contained the reddish-orange pigment seen in the ocellus of a living larva. Five-day old tornariae of P. flava are positively phototactic. Both cilium and microvilli may function as photoreceptors. The tornarian ocellus studied is compared with eyespots of other invertebrates, and the evolutionary significance of its putative photoreceptors is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306706
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  • 10
    Electronic Resource
    Electronic Resource
    The goldfish pituitary (1974)
    Springer
    Cell & tissue research 154 (1974), S. 231-249 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary ; Goldfish ; Innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the pituitary gland of Carassius auratus was studied by light and electron microscopy under various physiological and experimental conditions to investigate whether or not neurosecretory fibres play a role in regulating pars distalis function. Two types of neurosecretory fibre (Type A and Type B) were distinguished. Prolactin, ACTH and TSH1 cells were innervated by Type B fibre terminals separated from the endocrine cells by a continuous basal lamina (“indirect contacts”). Gonadotropic, STH and TSH2 cells were innervated by Type A as well as Type B neurosecretory fibres, mostly without an intervening basal lamina (“direct contacts”). The assessment of the amount of neurosecretory granules and microvesicles in nerve terminals during the pre-spawning, spawning and postspawning seasons and following the administration of Oestradiol, Thyroxine, Thiourea and Metopiron respectively revealed convincing evidence for a participation in pars distalis control for Type A and Type B fibres innervating gonadotropic cells and STH cells and Type B fibres innervating TSH2 and ACTH cells. Immediately after spawning both nerve fibre types innervating gonadotropic cells and Type A fibres innervating STH cells showed a striking decrease in the amount of dense core vesicles. During the spawning season nerve fibres innervating somatotropic cells, TSH2 cells and ACTH cells also undergo changes suggesting that prior to spawning major changes in the endocrine system of the goldfish take place.—These results point to a dual control, by peptides and amines, of teleost pars distalis function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223166
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