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  • 1985-1989
  • 1975-1979
  • 1970-1974  (217)
  • 1972  (217)
  • Ultrastructure  (115)
  • Electron microscopy  (102)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 10 (1972), S. 38-48 
    ISSN: 1432-0827
    Keywords: Bivalve ; Molluse ; Shell ; Carbonates ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La technique du bombardement à l'aide d'ion d'argon est utilisée pour réduire l'épaisseur de la coquille de carbonate de calcium des bivalvesMytilus etMercenaria pour examen au microscope électronique par transmission et en diffraction électronique; une comparaison est réalisée à l'aide de répliques simples, servant de témoins. Les résultats obtenus confirment les études antérieures de répliques et de microscopie par balayage. De plus, une structure “aérée” est mise en évidence dans la coquille des aragonites, et surtout dans le nacre deMytilus. Cette structure est interprêtée comme un artefact induit par la chaleur, formé par l'inclusion d'eau et de matériel organique, interprétation qui concorde avec les études chimiques et de microscopie électronique.
    Abstract: Zusammenfassung Die Beschießung mit Argonionen wurde angewendet, um die Dicke von Calciumcarbonat-Schalen der zweischaligen MuschelnMytilus undMercenaria zu reduzieren. Diese Technik erlaubte die Ausführung von Transmissions-Elektronenmikroskopie und Elektronendiffraktion, wobei gleiche Proben nach einer bereits bestehenden Methode vorbereitet und als Kontrollen herangezogen wurden. Es wurden zusätzliche Resultate zu den Muschelstruktur-studien erhalten, welche früher publizierte Arbeiten unterstützen, die mit der Abklatschmethode und der Raster-Elektronenmikroskopie ausgeführt worden waren. Zusätzlich wurde eine „schaumartige” Struktur der Muschelaragoniten, besonders im Perlmutter vonMytilus, beobachtet. Da es sich um ein durch Hitze verursachtes Artefakt handelt, wird diese Struktur als Einschlüsse von Wasser und organischem Material interpretiert, was den Befunden von verschiedenen veröffentlichten chemischen und elektronenmikroskopischen Arbeiten entspricht.
    Notes: Abstract Use is made of the argon ion-bombardment technique to reduce the thickness of calcium carbonate shells of the bivalvesMytilus andMercenaria for transmission electron microscopy and electron diffraction, with comparison of single-stage replicas of similar specimens serving as controls. As an additional approach to shell structure studies, it gives results which support earlier published work with both replicas and scanning microscopy. In addition, a “frothy” structure is detected in the shell aragonites, especially inMytilus nacre. As a heat-induced artifact, it is interpreted as representing trapped water and organic material inclusions, an interpretation consistent with several published chemical and electron microscope studies.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 10 (1972), S. 216-222 
    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).
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 9 (1972), S. 296-309 
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Enzyme ; Parathyroid ; Microdissection ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une nouvelle méthode d'isolement d'ostéoclastes est mise au point pour des analyses biochimiques et de microscopie électronique. Pour isoler les cellules par microdissection, des empreintes d'os métaphysaire sont utilisées. Cette méthode, supérieure aux coupes d'os, permet une meilleure préservation cytologique et enzymatique et permet d'obtenir des cellules totales plus faciles à manipuler, avec des résultats plus reproductibles. Par analyse planimètrique de cellules isolées, colorées histochimiquement, il apparait que les ostéoclastes constituent plus de 90% de la masse de l'échantillon. Les concentrations de la phosphatase acide et de certaines enzymes, liées au nucléotide pyridinique, entrant dans le métabolisme de l'acide citrique, sont déterminées dans des échantillons d'ostéoclastes, pesant de 0,2 à 2,0 μg, isolés à partir de rats normaux et parathyroidectomisés. L'activité en aconitase, mesurée en direction de la transformation de citrate en isocitrate, est de 0,5–0,8 M/Kd/H, la plus faible des activités étudiées. Les activités en GDH et NADP-ICDH sont 5 à 10 fois supérieures que celle de l'aconitase, mais seulement un dixième à un tiers de celle de la phosphatase acide, de la déshydrogénase lactique ou malique.
    Abstract: Zusammenfassung Es wird eine neue Technik beschrieben, welche die Isolierung von Osteoklasten für biochemische und elektronenmikroskopische Untersuchungen ermöglicht. Als Ausgangsmaterial zur Zellisolierung wurden Abstriche von Metaphysenknochen benützt. Die Verwendung von Abstrichen bietet gegenüber Knochenschnitten wichtige Vorteile, wie z.B. eine bessere Erhaltung der cytologischen und enzymatischen Eigenschaften sowie die Gewinnung von unverletzten Zellen, welche leichter verarbeitet werden können und besser reproduzierbare Daten ergeben. Durch planimetrische Analyse der histochemisch gefärbten Ausstriche von isolierten Zellen konnte nachgewiesen werden, daß die Osteoklasten über 90% des gesamten Probenmaterials ausmachen. Die Mengen verschiedener Enzyme, welche an Pyridinnukleotid gebunden und am Citronensäuremetabolismus beteiligt sind, sowie der sauren Phosphatase wurden in Osteoklastenproben bestimmt, welche ein Gewicht von 0,2–2,0 μg hatten und aus Knochen von normalen und mit Parathyroidextrakten behandelten Ratten isoliert worden waren. Die Aktivität der Aconitase, welche in der Richtung von Citrat zu Isocitrat gemessen wurde, war mit 0,5–0,8 M/Kd/H die niedrigste aller untersuchten Aktivitäten. Die Aktivitäten der GDH und der NADP-ICDH waren 5–10mal höher als jene der Aconitase, entsprachen jedoch nur einem Zehntel bis einem Drittel derjenigen der sauren Phosphatase, der Laktat- oder der Malatdehydrogenase.
    Notes: Abstract A new method is described by which osteoclasts can be isolated for biochemical and electron microscopic analyses. As a source of cells for isolation by microdissection, imprints of metaphyseal bone were used. The use of imprints provides important advantages over bone sections, including a higher degree of cytologic and enzymatic preservation, and the delivery of whole cells which are more readily manipulated and which yield data that are more readily reproduced. By planimetric analysis of the histochemically-stained isolated cell samples, it was shown that osteoclasts represent over 90% of the sample mass. The levels of several of the pyridine nucleotide-linked enzymes involved in citric acid metabolism, as well as acid phosphatase, were determined in osteoclast samples weighing 0.2 to 2.0 μg isolated from normal and parathyroid-treated rats. Aconitase activity measured in the direction of citrate to isocitrate was 0.5–0.8 M/Kd/H, the lowest of the activities studied. The activities of GDH and NADP-ICDH were 5 to 10 times higher than that of aconitase but only a tenth to a third that of acid phosphatase, lactic or malic dehydrogenase.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 159 (1972), S. 87-98 
    ISSN: 1433-8580
    Keywords: Ultrastructure ; Small lymphocytes ; Throracic duct lymph ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die charakteristische Feinstruktur der durch Drainage des Ductus thoracicus des Menschen gewonnenen Lymphocyten wurde beschrieben, ihre Größe und Kern-Plasma-Relation durch planimetrische Verfahren ermittelt. Zwei morphologisch unterschiedliche Formen kleiner Lymphocyten konnten beschrieben werden: Zellen, die durch einen chromatinarmen Kern und relativ lockeres Cytoplasma gekennzeichnet sind, das zahlreiche Zellorganellen (Golgifeld, Centriolen, Mitochondrien und freie diffus verteilte Ribosomen) einschließt, sowie Zellen mit chromatinreichen Kern und dichtem Cytoplasma mit auffallend wenig Mitochondrien, jedoch relativ zahlreichen freien Ribosomen. Eine mögliche funktionelle Bedeutung dieser beiden morphologisch unterschiedlichen kleinen Lymphocyten wird diskutiert. Danach werden die Zellen der ersten Gruppe als differenzierte Zellformen, die der zweiten jedoch als immunologisch aktivere kleine Lymphocyten angesehen.
    Notes: Summary The ultrastructure of small lymphocytes of human thoracic duct lymph is described and planimetric studies of their size and nucleus-cytoplasm relationship are made. Two morphologically different small lymphocytes could be recognized; cells with a nucleus with little chromatin and a relatively light cytoplasm inclosing many organelles (Golgifield, Centriol, Mitochondria, Monoribosomes), cells with compact chromatin and dense cytoplasm including only a few mitochondria but many monoribosomes. The possible function of these morphological different small lymphocytes was discussed. The first group is a well differentiated cellform, the second one may contain more immonulogical active small lymphocytes.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 138 (1972), S. 255-264 
    ISSN: 1432-0568
    Keywords: Myogenesis ; Cell surface material ; Cell contact ; Culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cell surface material and contact specializations were observed in embryonic chick skeletal muscle cells at early stages (prior to fusion) in monolayer culture. Ruthenium red-staining surface material was largely absent after prior treatment with trypsin. During reorganization into a tissue pattern dense staining amorphous material was seen at the cell surfaces and in the extracellular spaces of clustered cells; the free surface material was clumped, that between the cells more compact. This material appeared to be mucopolysaccharide and could be involved in adhesion. Numerous close junctions (intercellular space, 25–100 Å), as well as occasional focal tight junctions (no apparent intercellular space), were observed between apposed cells. These junctions semmed related to cellular adhesion and perhaps also to electrical coupling.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 137 (1972), S. 188-199 
    ISSN: 1432-0568
    Keywords: Pituitary gland ; Electron microscopy ; Dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The parenchymal cells of the pars distalis of the dog adenohypophysis were studied with the electron microscope. Criteria for the differentiation of four cell types included the size and shape of the cells and the size, shape and distribution of organelles and secretory granules. Three secretory granule-containing cells designated as I, II and III were observed. Cell type I was further divided into subtypes (Ia, Ib, Ic) on the basis of the granule size of maximal frequency. A fourth cell type (IV) contained no or only a few secretory granules. It was unique in having a highly irregular shape with cytoplasmic processes extending between the other cell types and also occasionally enclosing follicular cavities.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 136 (1972), S. 326-335 
    ISSN: 1432-0568
    Keywords: Gallbladder ; Electron microscopy ; Epithelium ; Embryology ; Mucopolysaccharides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The early development of the human gallbladder epithelium was studied in 25 foetuses with crown-rump (CR) lengths from 6.0 to 22.5 cm by light and scanning and transmission electron microscopy. The PAS-reaction was used to locate cellular mucosubstances. The development could be devided into previllous and villous stages by light microscopy. The incipient formation of villi was observed in the present material at the 12.5 cm stage. Electron microscopically, three stages of development in the gallbladder epithelial cells were noticed. In the first stage, only one epithelial cell type was found. The microvilli were undeveloped, and there were no secretory granules in the epithelial cells. In the second stage, the epithelial cells contained secretory granules. The other characteristics of this stage were pseudopod-like projections on the apical cell surfaces and development of microvilli into a brush border-like structure. In the third stage, the epithelium showed the same zonal construction as that of the adult gallbladder. The apical surface of the epithelial cell was convex, and the microvilli were well developed. There were no pseudopod-like projections on the apical cell surface. The secretory granules were similar to those seen in the normal epithelial cells of the adult gallbladder. Degenerating cells were sometimes seen in this stage. The PAS-reaction was positive in the second and third stages.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 137 (1972), S. 153-169 
    ISSN: 1432-0568
    Keywords: Embryology ; Epithelial autophagia ; Histocytochemistry ; Human palate ; Macrophages ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural and a histochemical study of the disintegration of the human fetal palatinal junctional epithelium was carried out. Special attention was focused both on the epithelium proper as well as on participation of the surrounding mesenchyma. Epithelial autophagia was noticed in the form of inclusion bodies with cellular remnants as well as general cellular disintegration. The disintegration was correlated to the cellular activity of acid phosphatase and AS-esterase. The differences between human and non-human material were recorded and discussed. In the surrounding mesenchyma, histiocytes (macrophages) were noticed participating in the epithelial disintegration, while ordinary mesenchymal cells seemed without importance. The study of activity of alkaline phosphatase reveals that the rapidly growing ossification center of the vomer was touching the superior aspect of the epithelial junctional seams, where the epithelial disintegration starts. Based upon the findings the following sequential steps of disintegration were discussed: 1) pressure from the outside (the vomer anlage), 2) epithelial autophagia and 3) heterophagia of epithelial remnants (invading histiocytes). The ultrastructure and histochemistry of the so-called epithelial pearls were described. The intercellular substance of the palatinal processes was found to consist of hyaluronic acid and of chondroitin-4- and/or-6-sulfate. The mutual ratio of the glycosaminoglucuronoglycans was discussed.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 136 (1972), S. 224-248 
    ISSN: 1432-0568
    Keywords: Basket cells ; Synapses ; Electron microscopy ; Golgi method ; Inhibition ; Axons ; Dendrites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stellate cells were studied in rapid Golgi preparations and in electron micrographs. These small neurons can be classified on the basis of their position in the molecular layer and the patterns of their dendritic and axonal arborizations as follows: (1) superficial cells with short, contorted dendrites and a circumscribed axonal arbor (upper third of the molecular layer); (2) deep stellate cells with radiating, twisted dendrites and with long axons giving rise to thin, varicose collaterals (middle third of the molecular layer); (3) deep stellate cells with similar dendrites and long axons giving collaterals to the basket around the Purkinje cell bodies (middle third of the molecular layer). An important characteristic of the stellate cell axon is that it generates most of its collaterals close to its origin. Even in long axon cells, only a few collaterals issue from the more distant parts of the axon. These forms contrast with the basket cell, which sends out long, straighter dendrites, and an extended axon that first emits branches at some distance from its origin. Furthermore, basket cell axon collaterals are usually stout in contrast to the frail, beaded collaterals of the stellate cell axon. The two cell types are considered to be distinct. In electron micrographs stellate cells display folded nuclei and sparse cytoplasm with the characteristics usual for small neurons. Mitochondria are often the most conspicuous organelles because of their size and pleomorphism. The dendrites cannot be followed for long distances in thin sections because of their irregular caliber and course. Axons can be recognized on the basis of their appearance in Golgi preparations as short stretches of slender fibers distended at close intervals and running athwart the grid of the parallel fibers. These distensions, full of ovoid or flattened vesicles, synapse on the shafts of Purkinje cell dendrites and also on the dendrites of Golgi cells, basket cells, and other stellate cells. In all cases the synaptic complex occupies about a third of the junctional interface, the synaptic cleft is somewhat widened, and the pre- and postsynaptic dense plaques are thin and almost symmetrical. Varicosities in the parallel fibers synapse with the soma and dendrites of stellate cells. These junctions display a widened synaptic cleft and asymmetrical pre- and postsynaptic densities. Junctions with climbing fibers (Scheibel collaterals) have also been seen. The form of the stellate cell indicates that it plays a role in cerebellar circuitry different from that of the basket cell, although both cells are inhibitory. It is probably concerned with local effects on Purkinje cell dendrites within the field of its afferent parallel fibers.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 137 (1972), S. 106-113 
    ISSN: 1432-0568
    Keywords: Anterior pituitary ; Mouse ; Tissue culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Suitability of an ordinary incubation system for the culture of anterior pituitary tissues of mice was examined by electron microscopy. It was found that this system has many advantages over Trowell's standard technique for tissue culture and is particularly suitable for the short-term culture. In this system the pituitary tissue cultures were maintained well for at least two days in a chemically defined tissue culture medium (TC 199) without any additives. Addition of 20% calf serum to the medium extended the period to up to five days. Any attempts to prolong it further, however, failed because of a massive necrosis and a great loss of the histological integrity. In the cultured tissues there an enhancement of the LTH cells and a suppression of the other granulated types of cells were observed. The follicular cells were found to hypertrophy and to actively participate in phagocytosis of cell debris.
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  • 11
    ISSN: 1432-0568
    Keywords: Chick embryo ; Granular pneumocytes ; Granular inclusions ; Lamellar inclusions ; Ultrastructure ; Lung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les inclusions lamellaires caractéristiques des cellules granuleuses de l'épithélium pulmonaire apparaissent chez le Poulet à 16 jours d'incubation. Elles dérivent d'inclusions granulaires que l'on peut déceler dans l'épithélium dès l'apparition de l'ébauche pulmonaire, à 21/2 jours d'incubation. Nous avons étudié l'évolution de ces deux types d'inclusions lorsque les ébauches pulmonaires sont transplantées sur des hôtes d'âge différent. Lorsque une ébauche pulmonaire jeune (21/2 à 3 jours) est greffée sur un hôte plus âgé (6 jours), l'évolution des inclusions granulaires est fortement stimulée et peut conduire à l'apparition d'organites présentant plusieurs des caractères des inclusions lamellaires. Lorsqu'au contraire, une ébauche pulmonaire est transplantée sur un hôte plus jeune (3 jours), deux cas peuvent se présenter: Ou bien l'épithélium ne contient pas encore d'inclusions lamellaires au moment de la transplantation (ébauche de 14 jours par exemple): le moment d'apparition de celles-ci est alors considérablement retardé et leur différenciation ne devient massive que lorsque les inclusions lamellaires apparaissent dans le poumon de l'hôte; Ou bien les inclusions lamellaires sont déjà différenciées (poumon de 18 jours par exemple): dans ce cas, leur différenciation se poursuit pendant toute la durée de la greffe. Lorsqu'une ébauche pulmonaire est transplantée sur un hôte plus âgé ou plus jeune, l'évolution ultrastructurale de l'épithelium est donc modifiée. Selon les cas, elle est stimulée ou, au contraire, freinée. Des facteurs présents dans le milieu intérieur de l'hôte influencent la différenciation des greffons. Ils pourraient également intervenir dans de développement normal des poumons.
    Notes: Summary The lamellar inclusions of the granular pneumocytes first appear in chick pulmonary epithelium at 16 days of incubation. They are derived from granular inclusions which can already be seen in the epithelium at the time when lung buds become distinct (at 21/2 days incubation). We have studied the fate of these two types of organelles after transplantation of embryonic lungs to hosts of a different age. When a young lung bud (21/2 to 3 days) is grafted into an older host (6 days), the development of the granular inclusions is strongly stimulated, and can lead to the appearance of organelles which exhibit several features characteristic of lamellar inclusions. When an embryonic lung is transplanted to a younger host, two situations can occur: Either the epithelium does not yet contain any lamellar inclusions at the time of transplantation (eg lung at 14 days); these appear after a considerable delay, and differentiate in large quantities only at the time of appearance of the inclusions in the host lungs. Or the lamellar inclusions are already differenciated (eg lung at 18 days), in which case, their differentiation continues in the host. Therefore, when a lung bud is transplanted into either a younger or older host, the ultrastructural development is modified. It is either stimulated or inhibited. Some factors, present in the host internal milieu, influence the differentiation of the grafts. These factors could also play a role in the normal development of the lungs.
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  • 12
    Electronic Resource
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    Anatomy and embryology 139 (1972), S. 93-105 
    ISSN: 1432-0568
    Keywords: Teleost ; Heart ; Cardiogenesis ; Electron microscopy ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscopic study has been made on the development of the heart of the plaice (Pleuronectes platessa L.) by the examination of tissue taken from fish at the stage when the heart-tube has formed right through the larval life and up two months postmetamorphosis. The process of developments of the heart is essentially the same as that in higher vertebrates but there are certain minor sequential differences with comparable chick tissue. By day 24 (ten days after hatching) the “early larval” heart has formed which is a trilaminar structure — a layer of myocardium bounded internally by endocardium and externally by epicardium. This condition lasts until the 4a (Ryland) stage with the onset of endocardial invagination into the myocardium which is the criterion distinguishing the “late larval” heart. The “late larval” heart lasts throughout metamorphosis of the larva and until two months post-metamorphosis when the total adult heart is assumed. Thus the process of cardiogenesis continues irrespective of hatching and of metamorphosis. This study supports the concept that the epicardium is derived from an extramyocardial source. No results are presented concerning the theory that, in its earliest stages, the myocardium has a secretory function in the production of cardiac jelly, or of myofibrillogenesis in the Teleost myoblast. Stellar configurations of short lengths of newly formed sarcomeres commonly radiate out from Z centres in early myocytes and it is suggested that this is a primitive feature of Teleost myogenesis. There is also a proliferation of mitochondria within the myocardial cells at metamorphosis which may be connected to the subsequent fast growth of the heart in the succeeding two months.
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  • 13
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    Archives of dermatological research 244 (1972), S. 273-275 
    ISSN: 1432-069X
    Keywords: Mongolian spot ; Blue naevus ; Melanocytes of connective tissue ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 14
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    Archives of dermatological research 244 (1972), S. 524-526 
    ISSN: 1432-069X
    Keywords: Electron microscopy ; Allergic contact dermatitis ; Lymphocytes ; Macrophages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 15
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    Archives of dermatological research 244 (1972), S. 536-540 
    ISSN: 1432-069X
    Keywords: Collagen and auto-immune diseases ; Endoplasmatic tubular structures ; Paramyxovirus-like-structures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 16
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    Archives of dermatological research 244 (1972), S. 540-542 
    ISSN: 1432-069X
    Keywords: Argyria ; Electron microscopy ; Basallamina ; Elastica ; Skin appendages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 17
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    Acta neuropathologica 21 (1972), S. 253-257 
    ISSN: 1432-0533
    Keywords: Haemangiopericytoma, Cerebral-Secondary ; Histology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A secondary haemangiopericytoma of the cerebral hemisphere in a woman of 23 is described. It is formed of cells arranged in masses around proliferating blood capillaries, and also in rosette patterns. The tumour cells are separated from the capillary endothelial cells by thick collars of basement membrane in abnormal amounts. The histology of the primary tumour of the sacrum, and of the secondary tumours in the lungs and nervous system, are similar. A metastatic haemangiopericytoma of the central nervous system appears not to have been previously reported.
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  • 18
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    Acta neuropathologica 21 (1972), S. 109-116 
    ISSN: 1432-0533
    Keywords: Infantile Neuro-Axonal Dystrophy ; Motor End Plates ; Nerve ; Spheroïds ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report the ultrastructure of neuromuscular biopsies in three cases of infantile neuro-axonal dystrophy. The presence of spheroïds in peripheral and intramuscular nerves, but also in the motor end plates allows the diagnostic of this disease, without doing cerebral biopsy.
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  • 19
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    Acta neuropathologica 21 (1972), S. 68-75 
    ISSN: 1432-0533
    Keywords: Myelinated Nerve ; Venom ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of right sciatic nerves of Swiss white mice was studied after being exposed to a venom solution ofAgkistrodon contortrix laticinctus (broad-banded copperhead) and to 0.9% NaCl solutions for periods of 1, 2 or 3 h. There was some “Wallerian-like” degeneration in all groups of nerves in the experiment. Additional neuropathological changes were noted in the nerves exposed to venom solutions. The connective tissue was affected most severely, while the basal lamina was unaffected. Schwann cells were vacuolated, and in the most extreme case, a type of myelin splitting occurred which was considered as a “demyelinative” effect. The results were compared to those of Martin and Rosenberg (1968) [15] on studies of the giant squid axon. References to additional fine structural studies of various other neuropathies were given.
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  • 20
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    Acta neuropathologica 21 (1972), S. 239-252 
    ISSN: 1432-0533
    Keywords: Ultrastructure ; Myotendon ; Zebra-Bodies (ladder-like structure) ; Rods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the adult and foetal human myotendon is described. At the myotendon the muscle fibre is surrounded by plasma and basement membranes which are never penetrated by the adjacent collagen fibrils of the tendon. Increased thickness and electron density of the plasma membrane and the myofilaments which merge with it occur at the myotendon and this electron dense zone corresponds to the terminal Z-line of the final sarcomere of the myofibril. In the adult the muscle fibre near the myotendon may contain nemaline rods and zebra-bodies. The tendon in the foetus shows much more activity of the fibroblasts than in the normal adult. The collagen fibrils of the early foetus are thinner in diameter than at later stages of development. The union of the tendon with cartilage is illustrated.
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  • 21
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    Calcified tissue international 9 (1972), S. 238-242 
    ISSN: 1432-0827
    Keywords: Dentine ; Ultrastructure ; Tubule ; Tooth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'étude ultrastructurale de la dentine humaine périphérique, de couronnes dentaires de sujets âgés de 11 à 75 ans, a montré trois aspects principaux du contenu des canalicules en coupe transversale. Il s'agit de canalicules apparemment vides, de canalicules contenant un matériel organique annulaire et, enfin, de canalicules totalement remplis d'un matériel organique d'aspect granulaire ou hyalin. Aucune terminaison nerveuse n'est visible à ce niveau.
    Abstract: Zusammenfassung Die ultrastrukturelle Untersuchung von peripherem menschlichem Zahnkronendentin bei Patienten im Alter von 11–75 Jahren hat drei Hauptaspekte des Inhaltes der Dentintubuli gezeigt. Sie bestehen bei transversalen Schnitten aus toten Gängen sowie beim Lumen der Tubuli entweder aus ringförmigen oder ganzausfüllenden Ablagerungen. Im äußeren Dentin wurden keine Nervenendigungen beobachtet.
    Notes: Abstract An ultrastructural study of peripheral human coronal dentin in patients aged 11 to 75 years, has shown main aspects of the dentinal tubular content. In transverse sections, they consist of dead tracts and annular or solid content to the tubular lumen. No nerve endings were observed in the outer dentin.
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  • 22
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    Journal of cancer research and clinical oncology 77 (1972), S. 279-291 
    ISSN: 1432-1335
    Keywords: Lung mouse tumors ; Chemical carcinogen ; Ultrastructure ; Pneumocyte II ; Crystalline inclusions ; Interstitial fibrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The pulmonary tumours induced in Swiss mice by NMUR seem to be constituted for the most part by cells closely related to the granular pneumocytes (pneumocytes II ou B). Other rarer cells, of epithelial bronchiolar aspect, may take part in the proliferation. The ultrastructural study of tumoral cells suggest that their secretory functions are disturbed. The origin of the crystalline intratumoral structures is discussed, as well as their possible relationship with the production of surfactant. The peritumoral areas are characterized by a dense interstitial flbrosis in which the collagen fibers are associated with an elastoid substance.
    Notes: Resumé Les tumeurs pulmonaires induites chez la souris swiss par le NMUR apparaissent essentiellement constituées de cellules apparentées aux pneumocytes granuleux (pneumocytes II ou B). D'autres cellules plus rares, de morphologie épithéliale bronchiolaire peuvent participer á la prolifération. L'étude ultrastructurale des cellules tumorales suggère que leurs fonctions secrétoires sont perturbées. Le mode de formation des structures cristallins intratumorales est discuté, ainsi que leur rapport éventuel avec la production du surfactant. Les territoires péri-tumoraux sont caractérisés par une fibrose interstitielle dense où les fibres de collagène sont associées à uns substance élastoïde.
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  • 23
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    Journal of molecular medicine 50 (1972), S. 552-556 
    ISSN: 1432-1440
    Keywords: Plasma cells ; Filaments ; Bence-Jones Plasmocytoma ; Synthesis of immunoglobulins ; Electron microscopy ; Plasmazellen ; Filamente ; Bence-Jones Plasmocytom ; Immunglobulinsynthese ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Plasmazellen einer Patientin mit einem Bence-Jones Plasmocytom (BJP) gutartigen Verlaufs zeigten im Ergastoplasma zylindrische Formationen, die aus granuliertem Reticulum und Grundplasma bestehen. In den Grundplasmaschichten liegen zirkulär geordnete filamentöse Strukturen verschiedener Ausprägung. Bei starker Entwicklung des filamentösen Materials bilden sich kristallgitterartige Gefüge. Die Strukturen im Grundplasma sind nur nach doppelter Fixierung in Aldehyden und Osmiumtetroxyd zu erkennen. Sie waren nicht in Plasmazellen 4 weiterer Patienten mit anderen Myelomtypen nachweisbar. Die Beobachtungen werden in bezug auf die Biosynthese der Immunglobuline diskutiert.
    Notes: Summary The ground substance of plasma cells of a Bence-Jones plasmocytoma with benign clinical course in a 55 year old female patient showed “cylindrical” formations composed of rough surfaced endoplasmic reticulum and ground substance. In the ground substance filamentous structures can be seen, sometimes showing a crystalline pattern. The filaments can only be demonstrated after double fixation in aldehydes and osmium tetroxyde. In the plasma cells of four patients with myeloma other than Bence-Jones plasmocytoma, similar structures could not be demonstrated. This observation is discussed regarding the biosynthesis of immunoglobulins.
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  • 24
    ISSN: 1432-5233
    Keywords: Cyclophosphamide treatment ; Guinea pig ; Experimental diabetes ; Immunodiabetes ; Immunosuppression ; Insulin resistance ; Islets of Langerhans ; Precipitating insulin antibodies ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Hyperglycémie, amélioration de la tolérance à l'insuline et modifications considérables à niveau des cellules B et A des ilots de Langerhans ont fait l'objet d'une observation, après immunisation par insuline et adjuvant, en cobayes produisant des anticorps anti-insuline précipitants. Le traitement par le cyclophosphamide inhibait la production d'anticorps anti-insuline, alors que la glycémie et la tolérance à l'insuline restaient aux mêmes niveaux qu'on pouvait vérifier chez les animaux de contrôle non immunisés. Même les îlots de Langerhans semblaient avoir subi des dommages moins importants par rapport à ceux des animaux qui n'avaient pas été traités par le cyclophosphamide.
    Abstract: Resumen En covayos productores de anticuerpos antinsulina precipitantes, tras inmunización con insulina y adyuvante, se ha podido observar: hiperglicemia, aumento de la tolerancia a la insulina y conspícuas modificaciones a cargo de las células A y B de las islas de Langerhans. El tratamiento con ciclofosfamida inhibía la producción de anticuerpos antinsulina, mientras la glucemia y la tolerancia insulínica permanecían en los mismos niveles que podían observarse en los animales de control no inmunizados. Las islas de Langerhans aparecían menos dañadas respecto a las de los animales no tratados con ciclofosfamida.
    Notes: Riassunto Iperglicemia, aumento della tolleranza all'insulina e cospicue modificazioni a carico delle cellule B ed A delle isole di Langerhans sono stati osservati, dopo immunizzazione con insulina in adiuvante, in cavie produttrici di anticorpi anti-insulina precipitanti. Il trattamento con ciclofosfamide inibiva la produzione di anticorpi anti-insulina, mentre la glicemia e la tolleranza insulinica rimanevano agli stessi livelli riscontrabili negli animali di controllo non immunizzati. Anche le isole di Langerhans apparivano meno danneggiate rispetto a quelle degli animali non trattati con ciclofosfamide.
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  • 25
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    Acta diabetologica 9 (1972), S. 655-687 
    ISSN: 1432-5233
    Keywords: Chinese hamster ; Diabetes ; Glycogen infiltration ; Kidney ; Nuclear glycogenosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Cette enquête sur l'ultra-structure du rein de hamsters chinois atteints de diabète a permis de relever des lésions glomérulaires légères, consistant en un épaississement non-homogène des membranes basales des vaisseux capillaires, des altérations de cellules de la mésange, une dilatation irrégulière des anses vasculaires. Sur la partie tubulaire, une accumulation de glycogène dans le cytoplasme des cellules de la partie distale et du tube collecteur ainsi que la présence de glycogène dans le noyau des animaux atteints d'un grave diabète et de kétose.
    Abstract: Resumen La presente investigación sobre la ultraestructura del riñón del hamster chino diabético, ha dado la posibilidad de poner en evidencia sutiles lesiones glomerulares, consistentes en el engrosamiento no homogéneo de las membranas basales de los vasos capilares, en alteraciones de las células del mesangio, en la dilatación irregular de las ansas; y, a cargo de la parte tubular, en una acumulación de glicógeno en el citoplasma de las células del tramo distal y del túbulo colector y en la presencia de glicógeno en el núcleo de los animales con diabetes grave y quetosis.
    Notes: Riassunto La presente indagine sulla ultrastruttura del rene di hamsters cinesi diabetici ha fatto rilevare fini lesioni glomerulari, consistenti in ispessimento non omogeneo delle membrane basali dei vasi capillari, alterazioni delle cellule del mesangio, dilatazione irregolare delle anse vascolari. A carico della parte tubulare, accumulo di glicogeno nel citoplasma delle cellule del tratto distale e del tubulo collettore; presenza di glicogeno nel nucleo negli animali con diabete grave e chetosi.
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  • 26
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    Cell & tissue research 123 (1972), S. 47-54 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Neurohypophysis ; Exocytosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Elektronenmikroskopische Untersuchungen an der Neurohypophyse von Ratte und Forelle ergeben, daß sich eine Exocytose von Elementargranula an den Endigungen der neurosekretorischen Fasern nur selten abspielt. Es wird daher angenommen, daß die Abgabe von Hormonen in der Neurohypophyse in der Regel nach dem Muster des „membrane-release“ abläuft. 2. Die Exocytose wird nicht durch eine unmittelbare tangentiale Fusion der Membran des Elementargranulums mit dem Plasmalemm der Nervenendigung (Axolemm) eingeleitet. Vor allem bei Anwendung eines Goniometertisches wird erkennbar, daß vor der Exocytose zwischen Axolemm und Membran des Granulums eine Verbindung in Gestalt eines Stieles entsteht. Die Länge dieses Verbindungsstückes entspricht etwa 2 Axolemmdicken. An der Basis des Stiels im Axolemm tritt das Stoma auf, durch das der Inhalt des Granulums bzw. dieses selbst das Axonende verläßt. 3. Die Herkunft kleiner membrannaher Vesikel (Durchmesser 500 Å) in den Endigungen neurosekretorischer Nervenfasern in der Neurohypophyse konnte nicht geklärt werden. Anzeichen einer kompensatorischen Endocytose im Sinne von Nagasawa, Douglas und Schulz (1970) wurden nicht beobachtet.
    Notes: Summary 1. Electron microscopical investigations of the neurohypophysis in rat and trout reveal that exocytosis of neurosecretory elementary granules from the nerve endings occurs only rarely. The authors are of the opinion that hormone release in the neural lobe follows mainly the “membrane-release” pattern. 2. Exocytosis is not performed by tangential fusion of the elementary granule membrane and the plasmalemma of the nerve ending (axolemma). Administering the goniometer technique one can observe the appearance of a stalk-like structure connecting the two membranes. The basis of the stalk in the axolemma corresponds to the site of the stoma through which the core of the vesicle leaves the nerve ending. 3. The mechanism of the origin of small clear vesicles (diameter 500 Å approx.) near the axolemma of the neurosecretory terminal has not been elucidated. The authors did not observe equivalents of a compensatory endocytosis in the vicinity of granules released by exocytosis.
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  • 27
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    Cell & tissue research 126 (1972), S. 193-205 
    ISSN: 1432-0878
    Keywords: Spermatozoon ; Chilopoda ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le spermatozoïde de Lithobius forficatus L. a été étudié grâce aux microscopes électroniques, classique et à balayage. Le spermatozoïde a une longueur d'environ 2 mm et comprend deux parties: la tête, avec l'acrosome et le noyau, et la queue, divisée en zone de liaison, pièce intermédiaire et pièce terminale. L'acrosome, entouré par du matériel fibrillaire exogène, a environ 4 μ de long sur 0,2–0,3μ de large. Le noyau spiralé (300 à 400 μ de long) est constitué d'un axe fibrillaire et d'une spire granulaire dans la région postérieure. La zone de liaison est composée de la partie basale différenciée du noyau et des parties antérieures du complexe flagellaire et de la pièce intermédiaire. La pièce intermédiaire, particulièrement longue (1,5 mm environ) est formée par le flagelle entouré de ses gaines et du manchon mitochondrial. La pièce terminale est un court prolongement flagellaire (6 à 7 μ). Les spermatozoïdes matures (prélevés dans les vésicules séminales) ont une structure mitochondriale légèrement différente de celle des spermatozoïdes prélevés dans le testicule.
    Notes: Summary The spermatozoon of Lithobius forficatus was investigated by transmission and scanning electron microscopy. The spermatozoon has a length of about 2 mm long, it is subdivided into a head with acrosome and nucleus, and a tail with a connecting piece, a middle piece and an end piece. The acrosome, surrounded by exogenous fibrillar material is about 4 μ long and 0.2–0.3 μ wide. The spiral nucleus (300–400 μ in length) consists of a fibrillar axis and of a whorl of granular material in the posterior part. The connecting piece is composed of the basal differentiated part of the nucleus and the anterior parts of the flagellar complex and middle piece. The latter is particularly long (about 1.5 mm) and consists of the flagellar complex and the mitochondrial sheath. The flagellar end piece is short (6–7 μ). Mature spermatozoa (seminal vesicles) have a mitochondrial structure slightly different from those within the testis.
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  • 28
    ISSN: 1432-0878
    Keywords: Neurones ; Lumbricus ; Monoamines ; Neurosecretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cerebral ganglion and the ventral nerve cord of Lumbricus terrestris have been studied with the electron microscope. The results are as follows: In the neuropile small granular vesicles (300 to 500 Å) occur in some varicose nerve fibres after fixation with potassium permanganate. This indicates the presence of noradrenaline. Sometimes only a few of the vesicles produce a positive reaction. After incubation with α-methyl-noradrenaline the numbers of nerve terminals with small granular vesicles greatly increase, indicating the presence of dopamine and/or 5-hydroxytryptamine. In this case the reaction is now complete. The number of small granular vesicles is largest in the terminal swellings. These findings are consistent with histofluorescence, chemical, and microspectrofluorometric analyses, which have demonstrated noradrenaline, dopamine, and 5-hydroxytryptamine in neurones in the central nervous system. Large granular vesicles (600 to 900 Å) are to be found in some perikarya, not identical with neurosecretory cell bodies. In this case the granular vesicles in the axon are smaller and fewer. This indicates a simultaneous proximo-distal transport and gradual decrease in size of the granular vesicles. The intraneuronal distribution of the vesicles is in agreement with the distribution of the fluorophores in the fluorescent neurones. Neurosecretory neurones are found most likely not to contain monoamines.
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  • 29
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    Cell & tissue research 126 (1972), S. 431-436 
    ISSN: 1432-0878
    Keywords: Golgi apparatus ; Granular endoplasmic reticulum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Numerous morphological continuities between the cisternae of the convex face of the Golgi apparatus and the granular endoplasmic reticulum (GER) were observed in post-division amebae that had divided following enucleation and renucleation. Electron microscopic radioautography with the use of 3H-uridine as a tracer indicated that perhaps the Golgi apparatus is derived from the GER. The possibility of the connections between GER and Golgi apparatus facilitating transport of materials between the two is also discussed.
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  • 30
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    Cell & tissue research 126 (1972), S. 466-482 
    ISSN: 1432-0878
    Keywords: Macrophages ; Microtubules ; Enamel organ ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the enamel organ of rat incisors macrophages are present in the zone of matrix formation, the transitional zone, the enamel maturation and pigmentation zone. The macrophages accumulate adjacent to redifferentiating amelocytes in the transitional zone. The macrophages phagocytize fragments of disintegrating amelocytes. In addition to the well known complement of organelles the macrophages present an elaborated microtubular system, scattered, thick filaments, a cortical feltwork of thin filaments, and spherical nuclear bodies. The microtubules emanate from “attached” and free pericentriolar satellites and radiate aster-like towards the cell surface or into pseudopods or curve along the nuclear surface for long distances, often related to nuclear constrictions. It is suggested that the microtubular system plays a prominent role in directional movement of the macrophages. The cortical filaments, if contractile, may create the cytoplasmic flow necessary for the cell motility.
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  • 31
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    Cell & tissue research 127 (1972), S. 1-8 
    ISSN: 1432-0878
    Keywords: Parathyroids ; Anurans ; Crystals ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytoplasmic and nuclear crystalline inclusions are described in parathyroid secretory cells of adult frogs (Rana temporaria L.) and their possible significance is discussed.
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  • 32
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    Cell & tissue research 127 (1972), S. 34-49 
    ISSN: 1432-0878
    Keywords: Cephalic kidney insects ; Diplura ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'ultrastructure du rein labial céphalique deCampodea chardardi Condé a été étudiée. Cette néphridie comprend trois parties: le saccule terminal, le labyrinthe et le canal excréteur. Les cellules du saccule sont des podocytes typiques, contenant de nombreuses vacuoles de pinocytose et des inclusions diverses. La lumière est envahie par des micro-organismes bacilliformes. Le labyrinthe possède des cellules à indentations basales profondes avec de nombreuses mitochondries, et des microvilli distaux. Le canal excréteur débouchant sur la face ventrale du labium est caractérisé par la présence d'une intima cuticulaire. Le rein labial des Diploures a été comparé avec des organes segmentaires néphridiens d'autres Arthropodes, et avec le néphron des Vertébrés.
    Notes: Summary The ultrastructure of the cephalic labial kidney ofCampodea chardardi Condé has been studied. Each nephridium is subdivided into three segments: end-sac, coiled tubule and efferent-duct. The cells of the sacculus are typical podocytes, and contain numerous pinocytotic vesicles and various vacuoles. The lumen contains micro-organisms. The cells of the coiled tubule bear basal infoldings with numerous mitochondria and distal microvilli. The efferent duct terminates close to the ventral face of labium, and possesses characteristic cuticular intima. The labial kidney of Diplura is compared with published data on the nephridial organs of other Arthropods and Vertebrate nephron.
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  • 33
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    Cell & tissue research 127 (1972), S. 116-126 
    ISSN: 1432-0878
    Keywords: Cell junctions ; Nexus ; Osmotic effects ; Fixatives ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Speicheldrüsen von Mückenlarven (Chironomus Thummi) haben eine ausgedehnte interzelluläre Kommunikation. In elektronenmikroskopischen Bildern der Speicheldrüsen wurden zwei Arten von interzellulären Verbindungen gefunden, die für die Zellkopplung verantwortlich sein könnten: septate junctions und close membrane junctions. Da die räumliche Ausdehnung der septate junctions viel größer zu sein scheint als die der close junctions, wurden erstere als wahrscheinliche Kopplungsstrukturen angesehen. Es gibt jedoch Hinweise, daß die Strukturen, welche die Zellkopplung bewirken, sehr labil sind. Unter den Faktoren, die zu einer Unterbrechung der zellulären Kommunikationen führen können, sind auch osmotische Effekte. Um mögliche Einflüsse dieser Art auf die Ultrastruktur zu verhindern, wurden die Drüsen für die mikroskopische Inspektion in isoosmotischen Lösungen fixiert. Unter diesen Bedingungen lassen sich ausgedehnte Membrankontakte vom nexus-Typ zwischen den Drüsenzellen erkennen. Ihre Ausdehnung scheint ebenso groß zu sein wie die der septate junctions. Es besteht nach diesen Befunden die Möglichkeit, daß wie in anderen kommunizierenden Zellsystemen, so auch in Speicheldrüsen die interzelluläre Kommunikation durch nexus bewirkt wird.
    Notes: Summary Cells ofChironomus salivary glands communicate through intercellular connections of high permeability. Electron micrographs of salivary glands show two kinds of junctions between the membranes of adjacent cells, which may be responsible for cell coupling: septate junctions and close membrane junctions. A large fraction of lateral cell surfaces is occupied by septate junctions, while the area of close membrane junctions appears to be very small. Consequently septate junctions have been considered as likely sites for intercellular coupling. There are however some indications that intercellular communication is provided by structures which seem to be unstable. As osmotic effects are among the factors which can disrupt cellular communications, we have tried to eliminate possible effects of the fixing solutions on the ultrastructure of intercellular connections by using isoosmotic fixatives. Under these conditions large regions of close membrane junctions of the nexus kind have been observed to occur between gland cells. They are of similar size as septate junctions. It seems to be possible that as in other communicating cell systems nexus could be the sites for intercellular coupling of salivary gland cells.
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  • 34
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    Cell & tissue research 127 (1972), S. 175-188 
    ISSN: 1432-0878
    Keywords: Vitelline membrane ; Chorion ; Ephestia ; Follicle cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies on developing egg chambers of the moth, Ephesita kühniella reveal that the precursors of the vitelline membrane are synthesized within follicle cells which are in contact with the oocyte. The vitelline membrane precursors appear to be synthesized by the rough-surfaced endoplasmic reticulum, and this material apparently moves to the Golgi cisternae where the definitive vitelline membrane precursor body is produced. The previtelline bodies are then secreted into the spaces between the oocyte and follicle cells, where they fuse to form a continuous membrane. Chorion formation begins with the deposition of a layer of tubules at the outer edge of the vitelline membrane which coalesce to form the inner edge of a thin, striated layer. In subsequent stages, several compartmented layers are rapidly secreted external to the striated layer, giving rise to the mature chorion.
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  • 35
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    Cell & tissue research 127 (1972), S. 356-373 
    ISSN: 1432-0878
    Keywords: Complex eye ; Formica polyctena ; Receptors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Analyse der Feinstruktur des Komplexauges der Ameise Formica polyctena ergab, daß der dioptrische Apparat der insgesamt 750 Ommatidien aus einer lamellierten Cornealinse und einem euconen Kristallkegel besteht. Zwei Hauptpigmentzellen umgeben schalenförmig den Kristallkegel, 8 Nebenpigmentzellen schirmen das Ommatidium in seiner ganzen Länge von der Cornea bis zur Basalmembran ab. Jedes Ommatidium besteht in seinem distalen Teil aus 8 Retinulazellen, 2 gegenüberliegenden schmalen und je 3 gegenüberliegenden großen Sehzellen. Weiter proximal tritt eine 9. Retinulazelle hinzu. Die Mikrovillisäume der Sehzellen verschmelzen zu einem zentralen Rhabdom. Im distalen Teil sind die Mikrovilli in 3 Richtungen angeordnet. Es wird im besonderen die Orientierung der Mikrovilli zur Augenlängsachse und zur Ommatidien-Symmetrieachse untersucht. Auch die 9. Sehzelle bildet Mikrovilli. Das Rhabdom endet an 4 basalen Pigmentzellen. Auf den Mikrovillisaum folgt im Querschnitt des dunkel adaptierten Ommatidiums ein Kranz von großen intrazellulären Vakuolen. Die anschließende cytoplasmatische Zone der Retinulazellen enthält viele Pigmentgranula und Mitochondrien; multivesikuläre und multilamelläre Körper sowie Golgiapparate treten nur selten auf. Die funktionelle Bedeutung des Ommatidienaufbaues und die Verteilung der Organellen bei Dunkeladaptation werden diskutiert.
    Notes: Summary The fine structure of the compound eye of the ant Formica polyctena was investigated. The eye consists of a total of 750 ommatidia, each containing a dioptric apparatus of a lamellated cornea lens, a eucone-type crystalline cone, and 8 long pigment cells which surround the ommatidium for its total length, i.e. from the cornea to the basal membrane. Each ommatidium has in its distal portion 8 retinula cells—6 large plus 2 small ones. The retinula cells are arranged in such a way that 3 pairs of large cells, and the one pair of the small cells lie opposite each other. Further proximally, a 9th retinula cell is encountered. The fused, centrally located rhabdom is built up by the microvilli of all nine retinula cells. The rhabdom ends at 4 basal pigment cells. In dark adapted ommatidia, a ring of large intracellular vacuoles is to be seen immediately peripherally to the rhabdom. The outer, cytoplasmic zone of the retinula cells contains many pigment granules and mitochondria; multivesicular bodies, onion bodies and Golgi apparatus are of relatively rare occurrence. The functional significance of the ommatidial structure and the arrangement of the cell organelles in the dark adapted condition are discussed.
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  • 36
    ISSN: 1432-0878
    Keywords: Synapses ; Crustacea ; Abdominal Ganglia ; Lateral glant fibers ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The abdominal ganglia of the crayfish Astacus pallipes contain numerous vertebrate-like synapses which are characterized by presynaptic vesicles, darkened pre- and post-synaptic membranes, cleft material, and post-synaptic “fuzz”. Such synapses occur throughout the ganglia but are most easily found dorsally, where the neuropile is relatively coarse. The neuropile is far from homogeneous. Regional variations in fiber size, in degree of profile tortuosity, and in kind, magnitude, and distribution of vesicular content result in conspicuous textural variations. The structural polarity of synapses between the lateral giant fibers and other neurons is consistent with known physiological polarity and, hence, validates our criteria for recognition of synapses within the ganglion.
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  • 37
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    Cell & tissue research 128 (1972), S. 42-57 
    ISSN: 1432-0878
    Keywords: Microglia ; Pericytes ; Cerebral cortex (cat) ; Transformation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Capillaries, pericytes and microglial cells in layer I of the cerebral cortex of normal adult cats have been studied with electron microscopy. The data obtained in this study show that pericytes are cells which are able to transform themselves into microglial cells by virtue of an activation process in which the astrocytic neuroglia appears to play a decisive role. By virtue of its structure, its mesodermic origin and its function the microglia has to be distinguished clearly from the astrocytic neuroglia and the oligodendroglia.
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  • 38
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    Cell & tissue research 128 (1972), S. 100-114 
    ISSN: 1432-0878
    Keywords: Connective tissue ; Gastropoda ; Globular cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Blasenzellen stellen ein typisches Zellelement im Bindegewebe der Gastropoden dar. Licht- und elektronenmikroskopische Untersuchungen an Cepaea nemoralis haben gezeigt, daß der größte Teil einer Blasenzelle mit einer veränderlichen Glykogenmenge angefüllt ist. Diese zentrale Glykogenansammlung verdrängt das Zytoplasma mit seinen Organellen auf den peripheren Bereich der Zelle einschließlich der Zellausläufer und einen schmalen Saum um den Zellkern. Das wichtigste Identifizierungs-merkmal der Blasenzelle ist eine sehr spezialisierte — hier als Spaltenapparat bezeichnete — Oberflächendifferenzierung. Die Auswertung von Serienschnitten hat gezeigt, daß diese Oberflächenstruktur durch eine zum Teil verzweigte Invagination des extrazellulären Raumes gebildet wird, die wiederum von der Blasenzelle durch eine mäanderförmig unterbrochene Platte abgedeckt ist. Zwischen dem Spaltenapparat der Blasenzellen und dem Reusenapparat der Podozyten der Niere scheint eine Ähnlichkeit zu bestehen.
    Notes: Summary The globular cells are typical elements of the connective tissue of Gastropods. Light- and electronmicroscopic investigations of Cepaea nemoralis have shown, that these cells are filled with variable contents of glycogen, accumulated in the centre of the cell. This crowds the cytoplasm and the cell organelles into the peripheral area, including the cell processes and a narrow band surrounding the nucleus. The typical element of the globular cell is a special differentiation of the cell surface, the so-called “Spaltenapparat”. The three-dimensional organisation of the “Spaltenapparat” has been analysed by serial ultrathin sections. The reconstruction shows, that the “Spaltenapparat” consists of numerous branched invaginations of the extracellular space covered by very small, winding cell processes; there are tiny clefts between them. There appears to be some similarity between the “Spaltenapparat” of the globular cells and the pedicels of the podocytes of the renal glomerulus.
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  • 39
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    Cell & tissue research 128 (1972), S. 135-138 
    ISSN: 1432-0878
    Keywords: Spinal cord ; Mouse ; Myelinated neuronal soma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Im Thorakalmark (Hinterhornbereich) einer Wildmaus wurde ein kleines Nervenzellperikaryon beobachtet, das vollständig von einer Markscheide umhüllt war. Die Zahl der Markscheidenlamellen variierte zwischen 7 und 12. An einer Stelle konnte ein sogenanntes inneres Mesoperikaryon nachgewiesen werden. Die Bedeutung dieses zufällig erhobenen Befundes ist vorerst noch offen.
    Notes: Summary In the thoracic cord (posterior horn region) of a wild mouse, we have observed a small nerve cell soma completely enveloped by a myelin sheath. The number of myelin lamellae varied between 7 and 12. In one place, the existence of an inner ‘mesoperikaryon’ could also be shown. The significance of this fortuitous finding has not yet been explained.
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  • 40
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    Cell & tissue research 124 (1972), S. 465-478 
    ISSN: 1432-0878
    Keywords: Anterior pituitary ; Mouse ; in vitro ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Anterior pituitaries of mice were incubated for periods up to four hours in Krebs-Ringer bicarbonate glucose gassed with 95% O2∶5% CO2. The incubated explants survived and retained a fine structure that approximated the condition in situ. The few necrotic cells were sharply localized, and were found to be due to initial mechanical damage to the tissue. Some cells of the six granulated types exhibited slight but significant changes attributable to the liberation from the hypothalamic control: in LTH cells there was a release of preexisting granules and a development of cell organelles, whereas in other cell types there was an inhibition of release of granules and an enhanced digestion of the accumulated granules by the lysosomal system. Follicular cells responded uniquely to the changed environment by hypertrophy of the cytoplasm and were found to phagocytize cell debris. A part of non-epithelial elements of the gland showed a tendency to modulate cytologically.
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  • 41
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    Cell & tissue research 124 (1972), S. 454-464 
    ISSN: 1432-0878
    Keywords: Lateral-line organ ; Eel (Anguilla japonica) ; Mechanoreceptor ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sensory epithelium of the lateral line organ of the common eel consists of two types of cells, (sensory and supporting). The sensory cell bears a kinocilium together with about 40 to 60 stereocilia on its surface. The kinocilium is situated either at rostral or at caudal margin of this cilial group. Such polarity of the cilial group of one cell is inverse to that of an adjacent cell. Two types of crystal-like inclusions exist in the sensory cells, consisting of granules 100 Å in diameter. Granules in one type are arranged regularly whereas those in the other rather irregularly. Two types of nerve endings exist at the base of sensory cells: one is predominant in number and contains few vesicles, accompanied by a dense spherical body surrounded by small vesicles in the sensory cell and the other is rare in number and contains many vesicles, accompanied by a small flat sac just beneath the plasma membrane of the sensory cell. The supporting cells contain numerous mitochondria, a well developed Golgi apparatus and rough-surfaced endoplasmic reticulum, and surround a sensory cell completely. Physiologic significance of some of these components is discussed.
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  • 42
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    Cell & tissue research 126 (1972), S. 53-74 
    ISSN: 1432-0878
    Keywords: Oogenesis ; Rhesus monkey ; Meiotic chromosomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ovaries of foetal and neonatal rhesus monkeys have been examined with the electron microscope. The fine structure of the germ cells (oogonia; oocytes at the preleptotene, leptotene, zygotene, pachytene and diplotene stages of meiotic prophase) closely resembles that of corresponding human cells. Stages in spontaneous atresia are also described. Cytoplasmic organelles in oogonia are sparse and are grouped mainly at one pole of the nucleus, but become dispersed and more abundant as oogenesis proceeds. The nuclei of oogonia contain a random fibrillar matrix which becomes organized into threads at pre-leptotene. At leptotene these chromosomal threads each contain a dense axial “core”; during zygotene they become loosely paired in a “bouquet” arrangement and at pachytene the bivalents contain synaptinemal complexes. “Single” cores reappear at diplotene, surrounded by a complex fibrillar sheath organized into lateral projections and loops with associated granules: such chromosomes resemble those in human primordial oocytes although they are more diffuse. These findings support the view that at the diplotene stage mammalian oocytes contain chromosomes of the lampbrush type. Observations on the monkey are compared with those on other species, and the ways in which chromosomal organization may influence the radiosensitivity of oocytes is discussed.
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  • 43
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    Cell & tissue research 129 (1972), S. 1-10 
    ISSN: 1432-0878
    Keywords: Spermatogonia ; Fish ; Annulate lamellae ; Chromatoid bodies ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Observations on annulate lamellae and chromatoid bodies in spermatogonia of the cyprinid fish Pimephales notatus have revealed several commonly occurring features heretofore unreported: These include (a) the presence of annulate lamellae in close association with chromatoid bodies; (b) the existence of a chromatoid “band” or “shell” between the nuclear envelope and some chromatoid bodies with connections among them; (c) the presence of annulate pore complexes in the absence of well developed membrane envelopes as well as in association with such envelopes; (d) the presence of material just outside the nucleus and contiguous with nuclear pores which is of a similar density and texture to that of the chromatoid bands and chromatoid bodies; (e) filamentous material between the cytoplasmic sides of nuclear pores and the chromatoid “band”, bridging a distance of approximately 1000 Å and similar threads extending a like distance between chromatoid bodies (and bands) and annulate lamellae associated with them; and (f) mitochondria closely arranged about some chromatoid bodies.
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  • 44
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    Cell & tissue research 126 (1972), S. 335-347 
    ISSN: 1432-0878
    Keywords: Glandulae submaxillares ; Mammals ; Duct cell granules ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Discrete, PAS-positive granules of relatively uniform electron-density and size characterise the intercalated duct cells of mammalian submaxillary glands. Smaller, electron-dense organelles are seen in the cells at the junction of the intercalary-striated duct region in the guinea-pig. The large granules of variable electron-density which are observed in the proximal, modified intercalary cells in the rabbit closely resemble the granules in the acinar cells of the guinea-pig. Several populations of granules differing in size are found in the striated granular tubules of the rat and hamster; the organelles in the rat show two grades of electron-density whereas those in the hamster are uniformly dense. Numerous small granules with compactly arranged intragranular material occupy the apical part of the striated ducts of the cat, dog and rabbit. The chemical composition of each population of duct cell granules is unknown. The question whether granules containing kallikrein, trypsin-like enzymes and amylase are stored in the duct cells is discussed.
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  • 45
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    Cell & tissue research 126 (1972), S. 437-445 
    ISSN: 1432-0878
    Keywords: Eye ; Sarcophaga bullata ; Ommatidia ; Lamina ganglionaris ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary External and internal surfaces of the compound eye of the flesh fly, Sarcophaga bullata, were examined with a scanning electron microscope. A low patterned corneal nippleridge array and sparse setiform interfacetal hairs were observed on the corneal lens surface. Particular cleavage planes revealed outlines of the Semper Cells, their nuclei and distal terminations of photoreceptor cells. The latter, with their axonal processes, were visualized and described. These axons were noted traversing the external chiasma and entering the lamina ganglionaris where suggestions of synaptic contact were pointed out. The present descriptions were correlated with those taken from literature of the transmission electron microscope.
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  • 46
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    Cell & tissue research 127 (1972), S. 127-148 
    ISSN: 1432-0878
    Keywords: Nuclear envelope ; Amphibian oocytes ; Nuclear pore complex ; Chemical nature ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to investigate the chemical composition of the nuclear pore complexes isolated nuclei from matureXenopus laevis oocytes were manually fractioned into nucleoplasmic aggregates and the nuclear envelopes. The whole isolation procedure takes no more than 60–90 sec, and the pore complexes of the isolated envelopes are well preserved as demonstrated by electron microscopy. Minor nucleoplasmic and cytoplasmic contaminations associated with the isolated nuclear envelopes were determined with electron microscopic morphometry and were found to be quantitatively negligible as far as their mass and nucleic acid content is concerned. The RNA content of the fractions was determined by direct phosphorus analysis after differential alkaline hydrolysis. Approximately 9% of the total nuclear RNA of the matureXenopus egg was found to be attached to the nuclear envelope. The nonmembranous elements of one pore complex contain 0.41×10−16 g RNA. This value agrees well with the content estimated from morphometric data. The RNA package density in the pore complexes (270×10−15 g/μ3) is compared with the nucleolar, nucleoplasmic and cytoplasmic RNA concentration and is discussed in context with the importance of the pore complexes for the nucleo-cytoplasmic transport of RNA-containing macromolecules. Additionally, the results of the chemical analyses as well as of the3H-actinomycin D autoradiography and of the nucleoprotein staining method of Bernhard (1969) speak against the occurence of considerable amounts of DNA in the nuclear pore complex structures.
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  • 47
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    Cell & tissue research 127 (1972), S. 50-86 
    ISSN: 1432-0878
    Keywords: Salivary glands ; Drosophila, larval ; Differentiation ; Involution ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Entwicklung bzw. Differenzierung der larvalen Speicheldrüse vonDrosophila melanogaster wurde an genau datierten Altersstadien aus dem III. Larvenstadium, der Vorpuppe und der Puppe mit lichtmikroskopischen und elektronenmikroskopischen Methoden untersucht. Zur Vermeidung großer Streuung im physiologischen Alter der Tiere wurde eine Kulturmethode entwickelt, die es erlaubt, die Häutungen zu beobachten und zur Altersbestimmung heranzuziehen. Folgende Ergebnisse wurden erzielt: 1. Die Speicheldrüse besteht bis zur Mitte des III. Larvenstadiums morphologisch aus einem einheitlichen Zelltypus, der sehr kleine Sekretgrana (∅ 0,3 μm) bildet. Diese sammeln sich am Zellapex. Die Vermutung liegt nahe, daß es sich um ein Verdauungssekret handelt.In der 2. Hälfte des III. Larvenstadiums differenzieren sich drei Zelltypen, die hier Corpuszellen, Übergangszellen und Halszellen genannt werden. Dabei ist ein Differenzierungsgradient von distal nach proximal zu beobachten. Die distal gelegenenCorpuszellen stellen die Bildung des Verdauungssekretes in der 2. Hälfte des III. Larvenstadiums ein und bilden stattdessen ein Klebesekret. Dieses Sekret wird in Form großer Grana (∅ bis zu 10 μm) zunächst in den Zellen gespeichert und kurz vor der Pupariumbildung ins Lumen der Drüse abgegeben. Kurz nach der Pupariumbildung wird das Klebesekret aus dem Körper entlassen und dient dazu, die Tönnchenpuppe an einem trockenen Substrat anzuheften. Das Klebesekret ist PAS-positiv. Wahrscheinlich handelt es sich um ein Mucoproteid. Während des Vorpuppenstadiums bilden sich in den Corpuszellen große Vakuolen, die auf Grund der elektronenmikroskopischen Befunde als Ausdruck einer weiteren Sekretionsphase und nicht als beginnende Degeneration gedeutet werden. Die mögliche Bedeutung dieses Sekretes wird diskutiert. DieÜbergangszellen liegen zwischen den Corpuszellen und den Halszellen. Sie bilden ebenfalls Klebesekret, jedoch mit zeitlicher Verzögerung. Kurz vor der Pupariumbildung sind sie wie die Corpuszellen mit ausgereiften Klebesekretgrana beladen und von diesen nicht mehr zu unterscheiden. Die proximal gelegenenHalszellen bilden kein Klebesekret, sondern setzen die Bildung des Verdauungssekretes in der 2. Hälfte des III. Larvenstadiums fort. Während des Vorpuppenstadiums bilden sich in den Halszellen nicht die großen Vakuolen wie in den Corpuszellen. 2. Die Involution der larvalen Speicheldrüse erfolgt nach der Puppenhäutung durch Autolyseprozesse, die am distalen Ende der Drüse beginnen und innerhalb 1 Std alle Zellen mit Ausnahme der Imaginalanlage erfassen. 3. Die in dieser Untersuchung erhobenen entwicklungsgeschichtlichen Befunde anDrosophila melanogaster werden mit Beobachtungen anDrosophila virilis, D. robusta undD. hydei verglichen. Dabei wird aufgezeigt, daß die Entwicklung der larvalen Speicheldrüsen von verschiedenenDrosophila-Arten enge Parallelen aufweist. Die bisher bekannten Zusammenhänge zwischen Stoffwechselaktivitäten im Zytoplasma und Genaktivitäten (Puffmuster) an den Riesenchromosomen dieser Zellen werden diskutiert.
    Notes: Summary The development and differentiation of the larval salivary glands ofDrosophila melanogaster have been investigated with light and electron microscopical methods. The organ has been dissected out of exactly dated stages of the III. instar larva, the prepupa and the early pupa. In order to avoid great variations in the physiological age of the animals a culture method has been developed, enabling the larval molts to be observed and used for identification of the age. The results are as follows: 1. The salivary gland of the early larva up to the middle of the III. instar period is a homogenous sack consisting of one sort of cells, in which very small secretion granules (∅ 0,3 μm) are synthesized. These secretion granules concentrate near the cellular apex. They are supposed to contain digestion enzymes. 2. In the second half of the III. larval instar period three cell types are differentiated, which are called corpus cells, transitional cells and collum cells. A gradient of differentiation from distal to proximal can be observed. 3. Thecorpus cells, located at the distal part of the gland, stop the production of digestion enzymes in the second half of the III. larval instar period and begin to synthesize a cement substance. This cement first is stored in grana (∅ up to 10 μm) inside the corpus cells. Shortly before puparium formation it is extruded into the lumen of the gland. Shortly after puparium formation it is expectorated out of the mouth, runs along the body wall and affixes the puparium to the substrate. The cement is PAS-positive, probably being a mucoproteid. In the corpus cells large vacuoles are formed during the prepupal instar period. On the basis of these electron microscopical results the vacuoles are interpreted to represent another form of a secretory product and not an equivalent of beginning degeneration. The possible function of this substance is discussed. 4. Thetransitional cells are located between the corpus cells and the collum cells. They also synthesize cement at a delayed rate, through shortly before puparium formation they are filled with cement like the corpus cells and cannot be distinguished from the latter. Thecollum cells form the most proximal part of the salivary gland. They do not produce cement but continue to synthesize digestion enzyme granules in the second half of the III. instar period. The large secretion vacuoles, found in the corpus cells during the prepupal instar period, are not synthesized in the collum cells. 5. The involution of the larval salivary gland begins after pupation and is indicated by autolytic processes, which begin at the distal end of the gland. One hour later all cells exept the imaginalanlage show signs of degeneration. 6. The course of development of the salivary glands investigated in the present study inDrosophila melanogaster is compared with similar investigations onDrosophila virilis, robusta andhydei. It is pointed out that the development of the larval salivary gland in different species ofDrosophila shows close parallels. The relationships between metabolic activities in the cytoplasm and gene physiological activities (pattern of puffs) on the giant chromosomes, as known so far, are discussed.
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  • 48
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    Cell & tissue research 127 (1972), S. 201-208 
    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.
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  • 49
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    Cell & tissue research 130 (1972), S. 70-92 
    ISSN: 1432-0878
    Keywords: Oocytes ; Different types ; Dinophilus gyrociliatus ; Cytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Dinophilus gyrociliatus bildet zwei Oocytentypen, einen größeren, aus dem ♀♀ hervorgehen (♀-Oocyte) und einen kleineren, der sich zu ♂♂ entwickelt (♂-Oocyte). Diese beiden Oocytentypen sind von frühen Stadien der Vitellogenese an durch ihr unterschiedliches Größenwachstum zu unterscheiden. Da bei Oogonien und prävitellogenen Oocyten keine zwei unterschiedlichen Zelltypen festzustellen sind, muß man annehmen, daß die Differenzierung in ♂- und ♀-Oocyten in einem zwischen der Prävitellogenese- und der Vitellogenesephase gelegenen Übergangsstadium beginnt. Während der Prävitellogenesephase finden Zellverschmelzungen statt, aber es konnten keine Beziehungen zwischen der Fusion von Oocyten und der späteren Differenzierung nachgewiesen werden. Die ♂-Oocyte beginnt schon auf einem frühen Stadium der Vitellogenese mit der Produktion von Mucopolysaccharid-Granula, die ♀-Oocyte erst später. Diese Granula bilden nach der Ablage der Eier die Ei- oder die Kokonhülle. Die ♀-Oocyte bildet größere Proteindottergranula als die kleinere ♂-Oocyte. Eine Trennung zweier Zellsorten nach Granulagrößen läßt sich schon auf dem Übergangsstadium durchführen. Der absolute RNS-Gehalt der reifen ♀-Oocyte liegt wesentlich über dem der ♂-Oocyte; dagegen ist die Konzentration der RNS in der ♂-Oocyte höher. Die RNS-Synthese verläuft in beiden Oocytentypen parallel zur Volumenzunahme und dauert bis zum Ende der Vitellogenesephase.
    Notes: Summary Dinophilus gyrociliatus produces two types of oocytes, a big, female producing “♀-oocyte”, and a smaller, male-producing “♂-oocyte”. They may be distinguished by their different volume from the beginning of the vitellogenic phase. Neither oogonia nor previtellogenic oocytes show two types of cells, and the beginning of differentiation in ♀-oocytes and ♂-oocytes has to be located in a connecting stage after the previtellogenic and before the vitellogenic phase. On previtellogenic stages the cells fuse and form bigger ones, but there is no connection to be found with the differentiation of the egg cells. The ♂-oocyte starts the production of mucopolysaccharid granules at an early vitellogenic stage; the ♀-oocyte does so only at later stages. These granules form the egg capsule after the eggs have been laid. The ♀-oocyte contains bigger protein yolk granules than the smaller ♂-oocyte. Already on the connecting stage it is possible to distinguish two groups of cells by the size of their granules. The ribonucleic acid content in the ♀-oocyte exceeds greatly that of the ♂-oocyte. The RNA-concentration, however, is higher in the latter one. During the vitellogenic stages the rate of RNA-synthesis in either type of oocytes parallels the increase in cell volume, the synthesis lasting up to the end of the vitellogenic phase.
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  • 50
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    Cell & tissue research 130 (1972), S. 302-311 
    ISSN: 1432-0878
    Keywords: Gonadal development ; Sex determination ; Germ cells ; Mollusca ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the gonad, from hatching through sexual maturity and oviposition, has been studied in Arion ater rufus and Deroceras reticulatum. At hatching, the gonad is comprised of several acini. These acini are hollow structures, the walls of which are generally one or two cell layers thick. This cell layer consists of intermingled germinal and non-germinal cells. Eventually, each acinus is divided into two compartments (cortical and medullar) by a layer of auxiliary cells. The auxiliary cells appear to differentiate into Sertoli and follicle cells. These three non-germinal cell types appear to form an uninterrupted cell barrier that isolates the female germ cells in the cortex from the male germ cells in the medulla. Thus, although these animals are hermaphroditic, the male and female germinal lines differentiate in physiologically isolated compartments.
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  • 51
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    Cell & tissue research 130 (1972), S. 279-301 
    ISSN: 1432-0878
    Keywords: Gonadal development ; Sex determination ; Germ cells ; Mollusca ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A cytological study has been made, at the light- and electron-microscope levels, of gonadal development in Arion circumscriptus. The gonad appears to be ectodermal in origin and is composed of two cell lines—germinal and non-germinal. These two lineages are established in the embryo. The germinal line is first represented by primordial germ cells while the non-germinal line is first represented by auxiliary cells. The primordial germ cells differentiate into spermatogonia and oogonia, the auxiliary cells into Sertoli cells and follicular cells. Spermatogonia and oogonia differentiate about the time of hatching. All subsequent germ cells appear to differentiate from these initial populations of spermatogonia and oogonia. The concept of a germinal epithelium, as a cell layer in which germ cells differentiate from indeterminate germ cells throughout the life cycle, is not supported by this study. A model for sex determination of the germ cells is proposed based on the hypothesis that sexually non-determined primordial germ cells are distributed into two physiologically isolated compartments (a male medullar compartment and a female cortical compartment). The spermatogonia and oogonia then differentiate in two different microenvironments.
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  • 52
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    Cell & tissue research 131 (1972), S. 31-45 
    ISSN: 1432-0878
    Keywords: Synapse ; Ultrastructure ; Giant fibre ; Crayfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of synapses between the cord giant fibres (lateral and medial) and the motor giant fibres in crayfish, Astacus pallipes, third abdominal ganglia have been examined. These electrotonic synapses are asymmetrical, they have synaptic vesicles only in the presynaptic fibre, and they have synaptic cleft widths normally of about 100 Å but narrowed to about 50 Å in restricted areas. Localized increases in density of the synaptic cleft and adjacent membranes also occur within a synapse, and synaptic vesicles are most tightly grouped at the membrane in such areas. Tight or gap junctions with 30 Å or narrower widths have not been found, but the junctions probably function in a similar way to gap junctions. Three small nerves are closely associated with the synapses between the giant fibres. One of these small nerves has round synaptic vesicles and is thought to be excitatory on morphological grounds; one has flattened vesicles and is thought to be inhibitory; and one is postsynaptic to the lateral giant and the two small presynaptic nerves. It is proposed that these small nerves modulate activity in the much larger giant fibre synapse.
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  • 53
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    Cell & tissue research 131 (1972), S. 47-62 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Lungfish ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neurohypophysis of the South American lungfish Lepidosiren paradoxa has been studied with light and electron microscopy, including the Falck-Hillarp technique for catecholamines. The pars nervosa hypophyseos is a well-marked, dorsally located subdivision of the pituitary gland composed of lobes or follicles, each one constituted of a central core of ependymal cells, a subependymal hilar region made up of nerve fibers and a peripheric palisade zone of nerve endings which contact capillary vessels. Four types of neurosecretory axons can be distinguished under the electron microscope. Type I, the most common, contains spherical elementary granules of high electron density, 1500–1800 Å in diameter. The scarce type II axons contain irregularly-shaped elementary granules. Type III contains only small clear vesicles, 400–600 Å in diameter. Type IV, mostly present in regions of the gland contacting the pars intermedia, contain large granulated vesicles, 900–1000 Å in diameter. The Falck-Hillarp technique revealed axons with a positive reaction for catecholamines at sites corresponding approximately to the location of type IV of the electron microscope. Ependymal cells are of large size, linking the cerebrospinal fluid, the nerve endings and the blood vessels. A conspicuous membrane-bound, spherical dense material, 1400–2000 Å in diameter, is observed in both the apical and vascular processes of these cells. The ependymal processes which traverse the hilar and palisade regions contain structures resembling degenerated neurosecretory axons. These results are discussed in relation with the currently available information on the comparative anatomy of the pars nervosa. The possible functional significance of ependymal cells and of each type of axon are also discussed. This study was aided by the following grants: NIH NS 06953 to Prof. De Robertis, Consejo Nacional de Investigaciones Científicas y Técnicas to Prof. Zambrano, Comisión de Investigaciones Científicas de la Provincia de Buenos Aires and Comisión de Investigaciones Cientificas de la Universidad Nacional de la Plata: to Prof. Iturriza. The authors are indebted to Prof. De Robertis for his generosity in granting us his laboratory facilities, and to Dr. F. J. J. Risso and Mr. A. Fernández (Resistencia, Chaco) who provided the specimens used in this study. The able microtechnical assistance of Miss L. Riboldazzi and Mrs. R. Raña and the photographic work of Mr. A. Saenz are much appreciated.
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  • 54
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    Cell & tissue research 131 (1972), S. 417-427 
    ISSN: 1432-0878
    Keywords: Lymphatic vessels ; Lung ; Centrioles ; Filaments ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron microscopic study of the pulmonary lymphatic collecting channels and their valves in the rabbit revealed that the endothelial cells generally contain two centrioles which are almost invariably associated with one to several striated bundles of filaments. The structure of the centrioles corresponds well with that in other cell types. The filaments however were present only in endothelial cells and not in the perilymphatic connective tissue cells. The bundles consist of 2 to 6 filaments of about 40 Å diamenter and show a cross banding with a periodicity of 600 to 900 Å. They are attached at both ends or in the middle of the centriole. Their function is unknown, but they might be vestigial rootlets of rudimentary cilia of lymphatic endothelial cells.
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  • 55
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    Cell & tissue research 132 (1972), S. 193-201 
    ISSN: 1432-0878
    Keywords: Branchial glands ; Cephalopods ; Haemocyanin synthesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The paired branchial glands in cephalopods are essential for life. The electron microscope reveals them to consist of cells containing masses of endoplasmic reticulum organised in parallel arrays together with pale areas between the reticulum that contain vacuoles. All three regions of the cells contain masses of haemocyanin particles and it is suggested that the gland is the site of haemocyanin synthesis, the particles being made amongst the endoplasmic reticulum at discharged into the pale areas and vacuoles before being released into the general circulation.
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  • 56
    ISSN: 1432-0878
    Keywords: Islets of Langerhans ; Grass-snake ; Crystalline B-granules ; Ultrastructure ; Crystallography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Kristalline B-Granula im Pankreas der Ringelnatter besitzen die Form von Rhombendodekaedern (a ≈ 11 nm, kubisch-raumzentriertes Gitter). Diese Diagnose wird abgeleitet von den Ergebnissen der dreidimensionalen Rekonstruktion von Serienschnitten, der optischen Diffraktometrie und aus dem Vergleich mit Kristallmodellen. Die Bedeutung kristalliner B-Granula wird erörtert.
    Notes: Summary Crystalline B-granules of grass-snake islets of Langerhans have been shown to possess the shape of rhombic dodecahedra (a ≈ 11 nm, cubic body-centered lattice). Three-dimensional reconstructions from serial sections, optical diffractometry and comparison with crystal models were the techniques utilized. The significance of crystalline B-granules is discussed.
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  • 57
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    Cell & tissue research 132 (1972), S. 15-24 
    ISSN: 1432-0878
    Keywords: Digestive diverticula ; Bivalves ; Peroxisomes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy of the digestive diverticula of the protobranch bivalve, Nucula sulcata, revealed the presence of peroxisomes in the basal regions of the epithelial cells lining the main and secondary ducts, and in the digestive and secretory (basophil) cells of the tubules. Those in the secretory cells are elongate and somewhat flattened, while those of the other cell types have a spherical form. Two distinct types of nucleoid are normally present within the secretory cell peroxisomes, one compact, crystalline, and finely polytubular, the other comprising isolated secondary tubules arranged in a linear series across the width of the organelle. The peroxisomes of the digestive and duct cells contain coarsely polytubular cores arranged in two clusters orientated more or less at right angles; the duct cell peroxisomes may also contain a second nucleoid in the form of a compact finely polytubular core. Sections incubated in a medium containing 3,3'-diaminobenzidine (DAB) and hydrogen peroxide reveal an electron dense reaction product within the peroxisomes of all the cell types. Catalase is considered to be responsible for the reaction.
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  • 58
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    Cell & tissue research 132 (1972), S. 67-78 
    ISSN: 1432-0878
    Keywords: Salivary glands ; Octopus ; Secretory fibers ; Synapse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les nerfs sécréteurs pénètrent dans l'épithélium des tubules au niveau du hile de la glande. Leurs subdivisions se disposent entre les cellules épithéliales ou leurs replis, et gardent toujours une situation extracellulaire. Les plus gros faisceaux d'axones sont encore entourés par des cellules satellites qu'on n'arrive plus à discerner autour des faisceaux moins importants ou autour des fibres isolées. Les axones sont alors directement au contact des cellules glandulaires. On a pu trouver des synapses neuro-glandulaires avec des spécialisations membranaires asymétriques comparables à celles décrites dans le système nerveux central des Vertébrés. Les fibres sécrétrices variqueuses contiennent d'autre part des vésicules de types variés, semblables à celles des troncs sécréteurs et moteurs du canal, et à celles des fibres motrices de la glande. La signification de ces vésicules a été discutée en relation avec l'existence possible d'amines biogènes diverses dans les fibres nerveuses.
    Notes: Summary The secretory nerves enter the tubule epithelium at the level of the gland hilus. Their subdivisions being located between the epithelial cells or their infoldings, have always extracellular position. Satellite cells still surround the largest axon bundles, but are no longer discernable round the smaller bundles or isolated axons which are thus in direct apposition with glandular cells. Neuro-glandular synapses, with asymetric membrane specialisations similar to those found in the central nervous system of vertebrates, have been found. The varicose secretory fibers contain various types of vesicles, similar to those found in the secretory or the motor trunks at the duct level, or in the gland motor fibers. The significance of these vesicles is discussed, in reference to the possible existence of various biogenic amines in the nerve fibers.
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  • 59
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    Cell & tissue research 132 (1972), S. 131-146 
    ISSN: 1432-0878
    Keywords: Nervous tissue ; Tardigrada ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Nervengewebe von Macrobiotus hufelandi zeichnet sich durch stark verzweigte pseudunipolare Nervenzellen und relativ wenige Gliazellen aus. Die Neurone besitzen rauhes ER, freie Ribosomen, zahlreiche Mitochondrien, einen wenig ausgeprägten Golgi-Apparat und einen elektronenlichten Kern. In ihren Axonen finden sich Vesikel und Einschlüsse unterschiedlicher Größe und Zusammensetzung. Die Gliazellen verzweigen sich stark und besitzen glattes ER, viele freie Ribosomen und einen elektronendichten Kern. Ganglien und Nerven werden nur durch eine dünne Neurallamelle vom extraganglionären Raum getrennt. Die morphologische Ausbildung des Nervengewebes wird im Hinblick auf die extreme Lebensweise der Tardigraden diskutiert.
    Notes: Summary The typical elements of the nervous tissue of Macrobiotus hufelandi are strongly ramified pseudunipolar neurons and a small amount of glial cells. In the perikarya of neurons there are rough ER, free ribosomes, many mitochondria, a poor Golgi-apparatus, and an electron-light nucleus. Nerve fibers contain masses of vesicles and inclusions of different size and composition. The ramifying glial cells have smooth ER, many free ribosomes, and an electron-dense nucleus. Ganglia and nerves are separated from the extraganglionic cavity by a thin acellular sheath (neural lamella). The organization of the nervous tissue is discussed with regard to the extreme conditions of environment of the tardigrades.
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    Cell & tissue research 132 (1972), S. 365-380 
    ISSN: 1432-0878
    Keywords: Golgi apparatus ; Membranes ; Cross-bridges ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron opaque cross-bridge structures span the inter- and intracisternal spaces and provide membrane-to-membrane connections between adjacent cisternae of dictyosomes of pollen tubes ofClivia andLilium. Additionally, the classic intercisternal rods, characteristic of intercisternal regions near the maturing face of dictyosomes, are connected with the adjacent membranes through similar cross-bridge elements. We suggest that these structural links are responsible for maintaining the flattened appearance of the central parts of Golgi apparatus cisternac as well as for the coherence of cisternae within the stack. Observations on other plant (e.g. microsporocytes ofCanna) and animal cells (e.g. rodent liver and hepatoma cells, newt spermatocytes) show that such an array of membrane cross-links is a universal feature of Golgi apparatus architecture. The cross-bridges appear as part of the complex “zone of exclusion” which surrounds dictyosomes, entire Golgi apparatus and Golgi apparatus equivalents in a variety of cell types.
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  • 61
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    Cell & tissue research 132 (1972), S. 451-472 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Myxine glutinosa ; Cell types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of adenohypophysial cells in the Atlantic hagfish (Myxine glutinosa) is described and the morphological evidence for secretory activity is discussed. A scarcity of secretory granules is characteristic of the adenohypophysis of Myxine. Two cell types having the appearance of protein hormone producing cells can be identified. Type 1 has dense membrane-bound granules with a calculated mean diameter of 88 nm while type 2 has larger granules with a mean diameter of 176 nm. The release of secretory granular material follows mainly the “membrane-release” pattern. It is suggested that cell type 1 may produce a hormone which is similar to ACTH/MSH and type 2 another hormone similar to STH/LTH. The basophilic cells contain a secretory material which is similar to the mucus produced in the epithelial mucus cells. Several structural modifications are considered to represent functional compensations for the absence of vascular elements in the gland. Among these are a cytoplasmic tubular system, certain long agranular cells together with long granule-containing projections from cell types 1 and 2, and foliate or finger-like invaginations of the basal lamina.
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  • 62
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    Cell & tissue research 133 (1972), S. 35-46 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Fowl ; Liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the liver parenchymal cell from immature pullets and from immature and young mature cockerels has been studied. The results demonstrated that the fowl's hepatocyte is structurally very similar to that of other birds and, in spite of certain morphological differences between the livers of birds and mammals, is also very similar in structure to the liver cell of mammals.
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  • 63
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    Cell & tissue research 130 (1972), S. 243-248 
    ISSN: 1432-0878
    Keywords: Blood vessels ; Chicken embryo ; Multivesicular structures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In verschiedenen Arten von Gefäß- und Mesenchymzellen in Allantois und Dottersack des Hühnchens wurden regelmäßig sog. „multivesicular structures“ beobachtet, die aus intrazellulären Aggregaten von Vesikeln (Durchmesser ca.: 800 Å) und/oder Vakuolen (Durchmesser bis 5000 Å) bestehen. Ähnliche Befunde anderer Autoren und die eigenen Ergebnisse sprechen dafür, daß es sich um das Substrat einer weitverbreiteten Zellreaktion handelt, die u.a. das morphologische Äquivalent der Sequestrierung eines z.B. im Zuge der Zelldifferenzierung überflüssig gewordenen Zytoplasmaanteils darstellt.
    Notes: Summary In the endothelial, the media and mesenchymal cells of the vessels in the chicken's allantoic and vitelline membranes “multivesicular structure” regularly occur. They consist of aggregated vesicles and/or vacuoles (diameters ranging from 800 Å to 5000 Å) and seem to present a rather common and widespread cellular reaction, that might serve as a mechanism to sequester those parts of the cytoplasm which became superfluous e.g. during cell differentiation.
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  • 64
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    Cell & tissue research 130 (1972), S. 312-317 
    ISSN: 1432-0878
    Keywords: Aphid cornicle ; Basal lamina ; Oenocyte ; Holocrine secretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light- and electron-microscopic observations on the cornicles of the rose aphid Macrosiphum rosae are presented, and discussed in relation to conflicting interpretations of cornicle structure and function. Lipid filled cornicle secretory cells occupy the lumen of the cornicle and extend into the abdominal cavity. The aphid is readily induced by mechanical stimuli to release cornicle secretory cells from a pore at the tip of the cornicle. The holocrine secretory cells are disrupted and release their lipid contents on leaving the body. They are enclosed within an acellular membranous sac that is apparently identical in structure with the basal lamina of the epidermis. The ultrastructure and anatomical relationships of the cornicle secretory cells suggest that they are oenocytes invaginated with the epidermal basal lamina, and are not anatomically or embryologically related to fat body.
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  • 65
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    Cell & tissue research 130 (1972), S. 338-350 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Salmon ; Gonad maturation ; Cell types ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the various hormone-producing cell types (with the exclusion of the prolactin cells) in the pituitary gland (pars distalis) of migratory sockeye salmon is described. All fish were in an advanced stage of sexual maturation. In the proximal pars distalis five cell types were distinguished: growth hormone cells, ACTH cells, gonadotrops, “vesicular cells”, and “chromophobe cells”. Gonadotrops were also found throughout the rostral pars distalis. A conspicuous feature of the gonadotrops was the presence of two kinds of secretory inclusions: small electron-dense granules (200–375 mμ) and large, relatively electron-translucent globules (400–2 000 mμ). The large vesicular cells, so called because of their conspicuous vesicular endoplasmic reticulum, were numerous and often appeared to contain some small granules. It is argued that they may represent a second type of gonadotropic cell, which, in earlier stages of gonad development, contains many granules but becomes largely degranulated near the time of reproduction when the other gonadotrops (“globular gonadotrops”) abound. The chromophobes, which were smaller and far less abundant than the vesicular cells, also appeared to contain small granules (120–280 mμ). They are probably thyrotrops.
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  • 66
    ISSN: 1432-0878
    Keywords: Ultimobranchial glands ; Urodeles ; Cell types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the ultimobranchial (UB) glands of two common laboratory urodeles, viz., larval axolotls, Ambystoma mexicanum Shaw and adult Pleurodeles waltlii Micahelles, is described and compared in what is believed to be the first ultrastructural report on urodele UB glands. The axolotl UB gland shows a wide variety of form, being represented by an elongated diffuse series of follicles and sometimes by one or two large discrete terminal follicular bodies. In these axolotl UB glands up to four cell categories are distinguishable including a tonofilamentous cell and a secretory cell that is possibly homologous with calcitonin-producing C cells of anurans or other vertebrates. These two cell categories are also found in the Pleurodeles gland. The possible significance of the various cells is considered.
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  • 67
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    Cell & tissue research 134 (1972), S. 255-271 
    ISSN: 1432-0878
    Keywords: Hepatopancreas ; Limulus ; Gap junctions ; Calcium spherules ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the hepatopancreas and associated tissues of Limulus is described. All hepatopancreatic tubules contain L- and D-cells. L-cells exhibit apical pinocytosis and contain many different types of inclusions, including lipid containing calcium spherules of unique structure. They also produce a complex secretory product released by apocrine secretion. D-cells contain much rough endoplasmic reticulum, and show other evidence of active protein synthesis. They produce a single type of secretory granule released by merocrine activity. The appearance of L- and D-cells in tubules of various sizes and in fed and starved animals is described. Both cell types may produce digestive enzymes and absorb and transport nutrients to the hemolymph, but neither serves as a major storage site. Storage is an important function of the intertubular R-cells. The appearance of R-cells in fed and starved animals is described. A previously undescribed hemocyte is reported, as are apparent gap junctions between L- and R-cells. A structural and functional comparison of these glands with those of other arthropods is presented.
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    Cell & tissue research 134 (1972), S. 273-282 
    ISSN: 1432-0878
    Keywords: Swim Bladder ; Gas gland cells ; Misgurnus fossilis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the wall of the rudimentary rear chamber in the swimbladder of the pond-loach was studied. The morphological features of a majority of the cells, as well as the presence of micro-rete mirabile, suggest that epithelial components in the wall of this organ represent a structural and functional equivalent of the gas gland.
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    Cell & tissue research 131 (1972), S. 347-370 
    ISSN: 1432-0878
    Keywords: Spermatozoon ; Pleurodeles ; Acrosome ; Differentiation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'origine et la morphogenèse des différents éléments de l'acrosome du spermatozoīde dePleurodeles waltlii ont été suivies et décrites depuis le tout début de la spermiogenèse. La formation de la vésicule acrosomienne et son évolution en une coiffe acrosomienne se fait selon le schéma classique. Son extrémité apicale se différencie tardivement en un bouton terminal et un crochet. Les trois parties de la coiffe diffèrent dans leur composition et leur structure fine. Les volumineux et complexes éléments situés sous la coiffe acrosomienne: axe, baguette puis manchon périphérique et manchon moyen, sont dépourvus de polysaccharides. Leur origine est envisagées. Ils sont comparés aux éléments situés dans l'espace sous-acrosomien des spermatozoīdes des autres vertébrés.
    Notes: Summary The origin and the morphogenesis of the acrosome different parts ofPleurodeles spermatozoon, have been investigated and described from the early beginning spermiogenesis process. The acrosomal vesicle and acrosomal cap formation take place according to the classical scheme. The acrosomal anterior tip cap late differentiate in a blunt terminal knob and a hook. The three cap parts differ in their composition and fine structure. The large and complicated structure stretching under the acrosomal cap: axis, peripheral muff and middle muff, are devoided of polysaccharides; their origin is discussed. They are compared with the subacrosomal components lying in the other vertebrates spermatozoon subacrosomal space.
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    Cell & tissue research 131 (1972), S. 429-436 
    ISSN: 1432-0878
    Keywords: Hormone granules ; Thyroid (C-cells) ; Anterior Pituitary ; Ultrastructure ; Freeze-etching method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Gefriergebrochene Präparate (mit und ohne Ätzung) der Adenohypophyse und der C-Zellen der Schilddrüse von Ratte und Meerschweinchen wurden elektronenmikroskopisch untersucht. Bei den Hormongranula dieser Zellen verlaufen die Bruchflächen im allgemeinen zwischen den beiden Membranflächen oder zwischen Granulum-Inhalt und Membran. Nur relativ selten werden Granula quergebrochen. Auf beiden Hälften der gespaltenen Membranen der C-Zellgranula werden etwa mit gleicher Häufigkeit Proteinpartikel (100–200 Å) gefunden. Bei den Granula der somatotropen Zellen treten auf der dem Plasma anliegenden Membranhälfte deutlich mehr Proteinpartikel auf als auf der dem Granuluminhalt anliegenden Hälfte. Der Inhalt der somatotropen und C-Zellgranula erscheint bei dieser Präparationsmethode aus einer dichten Packung von 80–100 Å großen Partikeln zu bestehen. Eine besonders strukturierte Zone zwischen Membran und Granuluminhalt konnte bei den bisherigen Untersuchungen nicht festgestellt werden. Durch Ätzung der Gefrierbrüche ließen sich keine zusätzlichen strukturellen Details der Granula darstellen. Eine durch Auswertung von stereoskopischen Aufnahmen gewonnene Größenverteilungskurve für die C-Zellgranula wird vorgelegt.
    Notes: Summary Freeze-fractured preparations (with and without etching procedures) of guineapig and rat thyroid (C-) cells and anterior pituitary (somatotropic-) cells have been investigated with the electron microscope. The hormone granules of these cells in general split either between the two lamellae of their unit membrane or between the granule contents and the unit membrane. Only rarely cross-broken granules have been observed. Inner and outer lamella of the unit membrane of the C-cell granules contain in more or less similar frequency moderate amounts of protein particles of 100–200 Å diameter. In case of the somatotrophs the outer lamella contains higher numbers of these particles than the inner one. The contents of the C-cell and somatotroph granules seems to consist of densely packed 80–100 Å particles. A particular zone between contents and membrane (as observed on micrographs with conventional electron microscopy) could not be detected on freeze-fractured preparations. The etching procedure does not reveal additional details of the granule structure. A size distribution curve of the C-cell granules as determined from stereo-pairs, is given.
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    Cell & tissue research 131 (1972), S. 497-517 
    ISSN: 1432-0878
    Keywords: Granulosa cells ; Oocyte ; Pig ; Mitochondria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pig oocytes and their surrounding granulosa cells obtained from mature Graafian follicles at a stipulated time near to ovulation were studied in some details electronmicroscopically. Particular emphasis is given to the corona radiata cell processes and to the heterogeneous population of mitochondria in the oocyte. The corona radiata cell processes contain various components such as filaments, mitochondria, multivesicular bodies and lipid droplets in their matrix. The contact relationship of the corona radiata cell processes to the oocytes is maintained by desmosomes. Usually, the two parallel surface membranes forming the desmosome are separated by a space of about 200 Å. Occasionally, the two membranes approximate each other to form a junction having a “gap” of about 70 Å. Apparently the membranes become fused in some regions. Of particular interest is the distribution and structural characteristics of the single-membrane-bounded structures, and their relationship to the cytomembranes and the mitochondria. On the basis of the present and earlier (Norberg, 1972) observations, the question arises whether the formation and development of mitochondria of pig oocytes depend, at least partly, on a metamorphosis of single-membrane-bounded structures derived from less complex membraneous elements. Final conclusions concerning this problem demand integrated morphological and biochemical investigation regarding the biosynthesis of mitochondria.
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  • 72
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    Cell & tissue research 132 (1972), S. 25-34 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Perivascular cells ; Neurosecretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The purpose of this study is to investigate the ultrastructural features of perivascular cells as found in the neural lobe of the hypophysis. In particular, an inquiry was made into the nature of the relationship of such cells to neurosecretory fibers and endings. The latter, in fact, are often invaginated within the perivascular cells and enveloped by their processes; furthermore, they often reveal a certain number of empty granules as well as characteristics of degenerative nature. In the course of this study the localization of the perivascular cells has been investigated as well as that of their processes within the extensive interlobular network typical of the hypophysial neural lobe of rodents. Based on the data gathered, the hypothesis is put forward that the perivascular cells play an important role in the turnover of neurosecretory endings, both under physiological and experimental conditions, contributing thereby to the release of post-hypophysial hormones.
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  • 73
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    Cell & tissue research 132 (1972), S. 51-65 
    ISSN: 1432-0878
    Keywords: Salivary glands ; Octopus ; Innervation of musculature ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les fibres nerveuses, souvent composées, qu'on peut trouver dans le tissu conjonctif séparant les fibres musculaires du canal, ou les tubules de la glande, sont très comparables morphologiquement aux fibres des troncs moteurs. Leurs cellules satellites, qui contiennent de grosses inclusions, nombreuses et très denses aux électrons, engainent les axones pratiquement jusqu'au niveau des terminaisons. Les jonctions neuromusculaires sont caractérisées par l'accumulation de petites vésicules claires, accompagnées de quelques vésicules plus grandes et à »coeur« dense. Les axones présentent aussi le long de leur trajet des segments plus ou moins dilatés où existent des vésicules de types très variés, et dont la signification est discutée.
    Notes: Summary Nervous fibers, often composite, can be found in the connective tissue between the duct muscular fibers, or the gland tubules. They are morphologically similar to the motor trunks fibers. Their satellite cells, containing numerous electron-opaque large inclusions, can be seen round the axons nearly to the nerve endings. Neuromuscular junctions are characterized by the accumulation of small clear vesicles, intermingled with some larger dense-cored vesicles. Axonal swellings, with numerous vesicles of various types, can also be seen along the course of the nerve fibers; their significance is discussed.
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  • 74
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    Cell & tissue research 132 (1972), S. 95-106 
    ISSN: 1432-0878
    Keywords: Olfactory sensilla ; Insects ; Necrophorus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Auf dem Endglied der Antenne von Necrophorus wird eine neue Sensillenform als Sensillum coelosphaericum beschrieben. Anhand von Merkmalen des cuticulären Apparates werden 2 Typen dieses Sensillums unterschieden. 2. Die Wand des cuticulären Apparates ist von einem Porensystem durchbrochen, das als reizleitende Struktur angesehen werden kann. Abweichend vom Porensystem basiconischer Sensillen finden sich bei den Sensilla coelosphaerica statt der Porentubuli sackförmige Bildungen, die aus einem dreidimensionalen Gitterwerk von miteinander vernetzten Filamenten bestehen. Diese Filamentsäcke enden bei Sensillum coelosphaericum Typ I in Einbuchtungen der 3. Hüllzelle, die hier den cuticulären Apparat auskleidet; bei Typ II grenzen sie an den äußeren Liquorraum. 3. Bei beiden Typen der Sensilla coelosphaerica werden die Dendriten auch innerhalb des cuticulären Apparates von einer Scheide umgeben. Das reizleitende System reicht nicht bis in unmittelbare Nähe der Dendriten. Die räumliche Anordnung der Strukturen führt zu der Auffassung, daß Duftmoleküle die Dendritenmembran nicht allein durch Grenzflächen-Diffusion erreichen Können.
    Notes: Summary 1. A new type of olfactory sensilla, named Sensillum coelosphaericum, was found on the distal segment of the antenna of the Carrion beetle Necrophorus. Two types of sensilla are differentiated by characteristics of their cuticular apparatus. 2. The wall of the cuticular apparatus is penetrated by pores which may function in the conduction of stimuli. The sensilla coelosphaerica differ from the basiconic sensilla in that they do not have pore tubules but have sac-like structures consisting of a three-dimensional network of filaments. In sensillum coelosphaericum type I, these sacs end in infoldings of a third enveloping cell which in this type coats the inside of the cuticular apparatus; in type II, on the other hand, the sacs of filaments border the outer liquor space. 3. Within the cuticular apparatus in both types of sensilla coelosphaerica, the dendrites are surrounded by a dendritic sheath. The stimulus-conducting system does not contact the dendrites. The arrangement of these structures implies that odour molecules can also reach the dendrite membrane by other means than surface diffusion.
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  • 75
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    Cell & tissue research 135 (1972), S. 211-228 
    ISSN: 1432-0878
    Keywords: Osteoclasts ; Rats ; Bone resorption ; Lysosomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoclasts in metaphyses from young rats were systematically sectioned at different levels. Two types of osteoclasts were recognized. One type had no ruffled border while the other, and predominant type contained a ruffled border in a part of its length; some of the latter contained two ruffled borders. The closest contact between osteoclast and bone occurred at the level of the ruffled border and this bone under the border showed characteristic changes indicative of resorption. In some osteoclasts the ruffled border consisted of numerous slender cytoplasmic projections separated by very narrow spaces or channels while in other osteoclasts it was more open. The ruffled border was commonly surrounded by a transitional zone containing numerous thin filaments. The osteoclast usually had its greatest dimension at the level of the ruffled border and the cytoplasm here contained many bodies and vacuoles but a sparse endoplasmic reticulum. Away from the level of the ruffled border the cytoplasmic vacuoles and bodies were fewer while the endoplasmic reticulum was often more pronounced. Parts of the osteoclasts were usually situated close to a vessel. It is suggested that there is a correlation between the development of the ruffled border and the degree of bone resorption and that osteoclasts without a ruffled border are, at least temporarily, inactive with respect to bone resorption. The numerous cytoplasmic bodies, interpreted as lysosomes, are presumed to be important in the resorption process. The closely adjacent positioning of osteoclasts and vessels may facilitate the transport of resorption products to the blood.
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  • 76
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    Cell & tissue research 135 (1972), S. 275-286 
    ISSN: 1432-0878
    Keywords: Oöcyte ; Resorption ; Locust ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The changes in the ultrastructure of the oöcyte and associated follicle cells during oösorption in Locusta migratoria migratoroides are described. Throughout the process the follicle cells act in a phagocytic manner and invade the oöplasm. Localizatio of acid phosphatase activity indicates that at the start of resorption the Golgi complexes of the follicle cells begin to produce lysosomes on a large scale, and that these are utilised in the breakdown of yolk spheres which have been taken up from the oöcyte. Partly degraded yolk spheres are collected together along with other cell organelles into cytolysomes. The significance of large numbers of microtubules within the follicle cells and of microvillar borders between the cells in late stage resorbing bodies is discussed.
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  • 77
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    Cell & tissue research 133 (1972), S. 82-102 
    ISSN: 1432-0878
    Keywords: Echinoidea ; Colour change ; Chromatophores ; Amoeboid movement ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Für den physiologischen Farbwechsel bei Vertebraten und Evertebraten gilt die Vorstellung, daß eine Pigmentbewegung innerhalb einer formkonstanten Zelle stattfindet. Am Seeigel Centrostephanus longispinus wird nun der Nachweis einer amoeboiden Bewegung von Pigmentzellen geführt: Die Epidermis von Centrostephanus enthält große braune Chromatophoren, die bei Belichtung eine Pigmentdispersion, bei Verdunkelung eine Konzentration des Pigments zeigen. Die Chromatophoren sind außerordentlich stark verzweigte Zellen, deren Arme dicht mit Pigmentgrana erfüllt sind. Im geballten Zustand ist die allgemeine Zellform mehr oder weniger ovoid, wobei die Zellarme eingezogen und dicht um die Zellmitte angeordnet sind. Dispersion des Pigments wird hervorgerufen durch Ausstrecken der pigmentierten Zellarme in den Interzellularraum des umgebenden Gewebes. Innerhalb der Zelle werden filamentöse Elemente nachgewiesen, die vermutlich für die Zellbeweglichkeit verantwortlich sind. — Ferner wird der zelluläre Aufbau des Integuments beschrieben.
    Notes: Summary Rapid colour changes in vertebrate and invertebrate species are considered to be due to movement of pigment granules within pigment cells of constant shape. Evidence is presented in this study to show that an amoeboid movement of chromatophores occurs in the epidermis of the Echinoderm Centrostephanus longispinus. The epidermis in this species contains large brown chromatophores, which display a dispersion of pigment on illumination and its concentration on darkening. The chromatophores are extensively branched cells, and their branches are densely packed with pigment granules. In the state of pigment concentration, the shape of the cell is more or less ovoid, and the cell branches are drawn in and closely arranged around the cell centre. Dispersion is attained by a stretching out of the pigmented cell branches into the intercellular spaces of the surrounding tissue. Within the cell, filamentous elements, which may be functional in the motility of the pigment cell, can be demonstrated.—Additionally the cellular composition of the integument is described.
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    Cell & tissue research 133 (1972), S. 163-179 
    ISSN: 1432-0878
    Keywords: Excretory organ ; Ileum ; Blatella germanica ; Ultrastructure ; Microprobe analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'iléon de Blatella germanica est un important segment d'accumulation minérale. Les nombreuses concrétions d'origine ergastoplasmique, contiennent du phosphore, du chlore, du calcium, du magnesium, du potassium et du fer dans un stroma glycoprotéique. La paroi de ce segment protodéal est constituée d'un type cellulaire unique caractérisé par la présence de feuillets apicaux et d'invaginations basales, différenciations membranaires décrites dans d'autres organes de transit, mais dont la coexistence constitue l'originalité de l'iléon. La signification physiologique de ce segment digestif est discutée.
    Notes: Summary The ileum of Blatella germanica is an important proctodeal segment of mineral accumulation. The numerous concretions, elaborated by the ergastoplasm, contain P, Cl, Ca, Mg, K and Fe in a glycoproteic matrix. The epithelium of this segment is composed by only one type of cells which are characterized by apical leaflets and basal infoldings. These membraneous differenciations have been already described in other transit organs, but their coexistence is typical of the ileum. The physiological significance of this digestive segment is discussed.
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  • 79
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    Cell & tissue research 135 (1972), S. 439-448 
    ISSN: 1432-0878
    Keywords: Neuromuscular junction ; Triturus ; Colchicine ; Axoplasmic flow ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Repeated injections of colchicine into the forearms of normal adult newts led to the disappearance of microtubules within some nerves and a concomitant loss of specialized morphological features at the neuromuscular junction. Within 2 weeks, the postsynaptic folds decreased in height and number, became flattened and eventually disappeared. In addition, nerve terminals in drug-treated animals became separated from the muscle surface and were highly congested with masses of synaptic vesicles. The present findings show that colchicine has an effect on the structural integrity of the neuromuscular junction. These effects could be direct; secondary to retraction of the nerve from the muscle surface; or the result of interference with the proper transport and/or release of neurotrophic substances.
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    Cell & tissue research 135 (1972), S. 449-459 
    ISSN: 1432-0878
    Keywords: Insect brain ; Neurons ; Glia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the neural sheath, glial cells and nerve cells in the brain of adult male houseflies is described. The neural sheath is composed of neural lamella and perineurium. The neural lamella consists of an external lamina and collagen-like fibrils which are embedded in an amorphous matrix. The perineurial cells form a continuous layer around the brain. On their inner surface, perineurial cells form junctional complexes with glial cell processes. A cortical cellular layer composed of neurons and glial cells surrounds the centrally located neuropil. Three types of glial cells are identified. Glial cells differ in size and in relative development and distribution of organelles. Thin processes of glioplasm completely surround the cell bodies of the neurons. Five types of neurons are described. Most of the neurons are monopolar, a few are bipolar.
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    Cell & tissue research 135 (1972), S. 461-471 
    ISSN: 1432-0878
    Keywords: Centriole assembly ; Basal bodies ; Ciliogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy of 16 to 18 day old chick tracheas revealed that procentrioles are present near the basal ends of the recently matured centrioles and basal bodies of both ciliating and ciliated cells. Cylinders 0.1 μ in outside diameter in which densely staining walls and a central axial filament can often be detected, are present between the mature centrioles and these procentrioles. These cylinders although somewhat shorter are morphologically similar to those found earlier in the same cells in the center of procentriole clusters. So far, only one procentriole has been found in association with each cylinder and only one cylinder in association with each mature centriole or basal body. Procentrioles up to 0.18 μ in length including some with singlet microtubules in their walls have been detected. Serial sectioning indicated that in some cells up to 8% of the mature centrioles and basal bodies were associated with a cylinder and a distinct procentriole. If these procentrioles were to mature they could provide additional basal bodies for cilia after the initial wave of centriole assembly and maturation has been completed.
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  • 82
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    Cell & tissue research 125 (1972), S. 88-107 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Bufo bufo ; Cell differentiation ; Larval growth ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Cinq types de cellules granulées se différencient au cours de la métamorphose dans la pars distalis de l'hypophyse du têtard de Crapaud. A la prémétamorphose apparaissent les deux types de cellules protidiques, les cellules glycoprotidiques de type II et des cellules glycoprotidiques d'un type intermédiaire. Cette dernière catégorie cellulaire disparaît au climax. A la prométamorphose se différencient les cellules glycoprotidiques de type IV. Au climax s'observent les cellules glycoprotidiques de type III. Les cellules glycoprotidiques de type II sont vraisemblablement responsables de la sécrétion de l'hormone thyréotrope (TSH). Il n'est pas encore possible de préciser la fonction des autres types cellulaires. Des fibres nerveuses ont pu être observées dans la pars distalis entre les cellules granulées.
    Notes: Summary Five granulated cell types can be distinguished in the Toad's pars distalis during larval growth. During premetamorphosis the two types of protidic cells appear, the glycoprotein containing cells of type II and an intermediary cell type which disappears during the climax. During prometamorphosis the glycoprotein cells of type IV are apparent. During the climax the glycoprotein cells of type III can be observed. The glycoprotein containing cells of type II probably produce the thyroid-stimulating-hormone (TSH). The function of the other cell types can not be specified for the moment. Nervous fibers have been observed in the pars distalis between granulated cells.
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    Cell & tissue research 133 (1972), S. 289-325 
    ISSN: 1432-0878
    Keywords: Nematosomes ; Neurons ; Substantia nigra ; Rat and Cat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Distinctive cytoplasmic inclusions, termed nematosomes, have been identified in the neurons, but not in the glial cells of the substantia nigra in the rat and the cat. These organelles which lack a limiting membrane consist of an entanglement of more or less tightly packed microfilaments or filamentous strands. According to the tridimensional arrangement of their filamentous components, as well as to their size and boundary, the nematosomes usually display several structural types: (a) round or oval, dense, filamentous bodies; (b) reticular inclusions with or without excavated centers; (c) ill-defined small aggregates of fine filaments. At higher magnification, each microfilament or filamentous strand, whatever the type of nematosome, is itself composed of similar subunits, about 20 Å in diameter. It should be pointed out that the latter subunits may be fine deposits of heavy metal on structural components of nematosomes, which appear to be similar in every structure. The ultrastructural organization of a given nematosome may vary from one portion to another. The functional significance of such structural variations from one nematosome to another, and even within a given nematosome, could not be elucidated by means of our ultrastructural study, although additional cytochemical and radioautographic work may throw light on this problem. These cytoplasmic bodies are present in the perikaryon of most neurons and one or more inclusions are usually observed in the same nerve cell. They are infrequently seen in the dendritic or axonal processes. The nematosomes are closely associated with the other cytoplasmic organelles filling the ground substance of neurons by means of microfilaments projecting from their surface. These cytoplasmic inclusions are, however, most frequently linked to surrounding free ribosomes and rough ER profiles. The association of free ribosomes with excavated nematosomes, which in turn contain neurofilaments in their core, suggests that these structures consist, partly at least, of precursor material which is assembled into the structural proteins of the neurofilaments after being synthesized by the neighbouring ribosomes. No special relationship with the neurotubules has been noticed. Nematosomes have also been found in structural relationship with other organelles, i.e. the smooth tubules and vesicles, the Golgi apparatus, the coated vesicles, the lysosomes and the mitochondria. The nematosome may be also closely associated with the subsynaptic web of axosomatic synapses and these two cytoplasmic components display many structural similarities. In the light of these and previously reported observations, it would appear that nematosomes are not incidental cytoplasmic inclusions, but common organelles of certain types of neurons.
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    Cell & tissue research 125 (1972), S. 143-175 
    ISSN: 1432-0878
    Keywords: Skin ; Cephalopods ; Chromatophores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rapid, physiological color changes seen in the skin of cephalopods are due to a unique anatomical system composed of chromatophore organs and iridophores. The morphology and ultrastructure of the chromatophores was studied in the squids Loligo pealii Lesueur and Loligo opalescens Berry. A three-dimensional model of a brown chromatophore was reconstructed from serial sections for the electron microscope. The chromatophore organ is composed of a central nucleated pigment cell, 10–30 obliquely striated muscle cells (radially arranged on the equator of the pigment cell), axons, Schwann cells, and sheath cells. The pigment cell consists of a central aggregation of pigment granules and surrounding peripheral cytoplasmic compartments. These regions are incompletely separated by an electron-dense, sac-like structure, the pigment container. Proximal portions of a muscle cell contact the pigment cell in regions called myo-chromatophore junctions. Neuromuscular and myo-muscular junctions are also present. The results presented are discussed in terms of previous morphological and physiological studies of chromatophores.
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    Cell & tissue research 125 (1972), S. 176-190 
    ISSN: 1432-0878
    Keywords: Skin ; Cephalopods ; Iridophores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two populations of iridophores are responsible for the iridescent color of the squids Loligo pealii and Loligo opalescens. The superficial group, the short iridophores, underlie the chromatophores and are associated with muscle cells of the skin. The long iridophores, a deeper-lying group, are arranged in a dense sheet. The ultrastructure of iridophores was described, including iridosomes, iridosomal platelets and iridosomal tubules. The observations were discussed in terms of adaptive coloration in these animals.
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    Cell & tissue research 125 (1972), S. 210-228 
    ISSN: 1432-0878
    Keywords: Regio olfactoria ; Teleosts ; Anguilla anguilla ; Ultrastructure ; 3 Different receptor types
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Flimmerepithel von Anguilla anguilla besteht aus 4 Zellarten: Flimmerzellen, Stützzellen, Basalzellen und Schleimbecherzellen. Flimmerzellen enthalten im oberen Zelldrittel zahlreiche Mitochondrien und tragen an ihrer Oberfläche bis zu 140 Kinocilien. Die Basalkörper dieser Kinocilien haben lange Wurzelfilamente, von denen ein Teil ins Zellinnere zieht; der andere Teil verläuft parallel zur Oberfläche und verbindet benachbarte Basalapparate. — Ein Übergangsepithel verknüpft das Flimmerepithel mit dem Riechepithel. Im Riechepithel finden sich außer den Zellarten des Flimmerepithels die Rezeptoren. Bei einheitlichem Aufbau des Zellkörpers lassen sich aufgrund rein morphologischer Unterschiede der Vesiculae olfactoriae 3 Rezeptortypen unterscheiden: 1. Cilien-Rezeptor, 2. Mikrovilli-Rezeptor und 3. „Pfriem“-Rezeptor. — Der Cilien-Rezeptor trägt unterhalb der Vesicula olfactoria in einer Einschnürung 4–8 sensorische Cilien, die alle auf gleicher Höhe entspringen. Zwei gegenüberliegende sensorische Cilien schließen einen konstanten Winkel von 60° ein. — Der Mikrovilli-Rezeptor trägt auf seiner abgerundeten Vesicula olfactoria 30 bis 60 Mikrovilli von 0,1 μm Dicke und bis zu 5 μm Länge. Der Mikrovillus wird von einem zentralen, 160 Å weiten, Tubulus durchzogen. Unterhalb der Vesicula olfactoria liegen mehrere Centriolen. Die Rezeptornatur dieser Zellen wird durch ein Axon unterstrichen. — Der „Pfriem“-Rezeptor besitzt eine 0,8 μm breite und bis zu 4 μm lange Vesicula olfactoria ohne sensorische Cilien und ohne Mikrovilli. Im Lumen der Vesicula olfactoria befinden sich neben Neurotubuli auch Fibrillen von 40–50 Å Durchmesser, die gebündelt auftreten. An der Basis des Köpfchens liegen mehrere Centriolen.
    Notes: Summary The ciliary and olfactory epithelia of the olfactory folds in Anguilla anguilla were studied with the electron microscope. The ciliary epithelium is composed of ciliary cells, supporting cells, basal cells, and mucous cells. The ciliary cells contain numerous mitochondria in their apical portion and bear up to 140 cilia. The ciliary basal bodies have rootlets, some of which project towards the central part of the cell, and others parallel to the cell surface thereby connecting neighbouring basal bodies. A transitional epithelium is located between the ciliary and olfactory epithelia. The olfactory epithelium is composed of the same 4 cell types of the ciliary epithelium and besides contains three morphologically different receptor cell types: ciliary receptor cells, microvillous receptor cells, and receptors with a single rodshaped free appendage. The ciliary receptors have 4 to 8 “sensory” cilia which project from below the vesicula olfactoria, each forming a constant angle of about 30° with the vertical cell axis. The vesicula olfactoria of the microvillous receptors bears from 30 to 60 microvilli, each of 0.1 μm diameter and up to 5 μm length. Each microvillus of this receptor type contains a central tubulus of 160 Å diameter. Few centrioles are located closely to the vesicula olfactoria. The third receptor type, which has neither cilia nor microvilli, is characterised by a single rod-shaped appendage of 0.8 μm diameter which projects up to 4 μm above the epithelial surface. This appendage contains neurotubules and fibril bundles; some centrioles lie close to the base of the appendage.
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    Cell & tissue research 125 (1972), S. 277-288 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Exocytosis ; Freeze-etching ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of rats subjected to severe acute haemorrhage under sodium pentobarbitone anaesthesia were examined electron microscopically and the ultrastructure compared with that in anaesthetised and unanaesthetised controls. Changes in the localisation and numerical distribution of elementary granules and small vesicles in the neurohypophysial nerve endings of bled rats were consistent with the occurrence of exocytosis. The occurrence of “exocytotic profiles” was observed more frequently in freeze-etched tissue samples as compared with the material fixed for conventional electron microscopy. The ratio of small vesicles: elementary granules was shown to be significantly increased (P〈0.005) in the nerve endings of neural lobes from bled rats. Equally, the numbers of exocytotic profiles related to 1000 μm2 of neurohypophysial tissue area were significantly greater (P〈0.005) in bled rats.
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    Cell & tissue research 125 (1972), S. 252-276 
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    Keywords: Amnion-Umbilical-cord-Skin ; Sheep ; Differentiation of the epithelia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Ektoblastderivate Amnion-, Nabelstrang- und Hautepithel von 14 Schaffeten zwischen 1,1 und 44 cm SSL wurden elektronenmikroskopisch untersucht. Das Amnionepithel ähnelt dem anderer Säuger; die tonofibrillenreichen Zellen sind mit Mikrovilli besetzt, seitlich sind sie stark miteinander verzapft. Das Schlußleistennetz bleibt bis zur Geburt erhalten. Der Golgiapparat ist kräftig entwickelt. Glatte Mikropinozytosevesikel von 600–800 Å Ø am basalen und seitlichen Plasmalemm werden mit fortschreitender Entwicklung zahlreicher. Größere Vakuolen fehlen. Das Nabelstrangepithel bleibt im Gegensatz zu anderen Spezies ein geringfügig modifiziertes Amnionepithel ohne eigene Differenzierung. In der zweiten Trächtigkeitshälfte sind die Interzellularräume durchschnittlich weiter als im peripheren Amnionepithel. Mikropinozytosebläschen kommen auch an apikalen Mikrovilli vor. Die Epidermis ist schon im einschichtigen Stadium nicht amnionähnlich, die apikalen Mikrovilli sind wesentlich spärlicher und kürzer, die Interzellularräume sind oft einfacher geformt, basal finden sich bereits Hemidesmosomen. Bei größeren Feten werden die Interzellularräume sehr eng, die Mikrovilli stehen in Gruppen. Weder in den glykogenbeladenen Peridermzellen noch in den Basalzellen sind Pinozytosevesikel, Fruchtwasservakuolen oder andere Indizien für einen Fruchtwassertransport zu finden.
    Notes: Summary The ultrastructure of the derivates of the ectoblast, the epithelia of the amnion, umbilical cord and skin has been studied in fetal sheep ranging from 1.1 to 44 cm CRL. The amniotic epithelium is similar to that of other mammals. The cells are rich in tonofilaments, they carry microvilli and are interdigitated with one another. Terminal bars are retained until birth. The Golgi apparatus is well developed. Smooth micropinocytotic vesicles with a diameter of 600–800 Å on the basal and intercellular cell membranes become more numerous with progressing development. Larger vacuoles are missing. The epithelium of the umbilical cord, contrary to that of other species, remains a slightly modified amniotic epithelium without special differentiation. The intercellular spaces are on the average wider in the second half of pregnancy than those in the peripheral amniotic epithelium. Micropinocytotic vesicles occur also on the apical microvilli. In the single layer stage the epidermis is dissimilar to that of the amniotic epithelium. The apical microvilli are far less numerous and shorter, the intercellular spaces are often of a more simple structure. Hemidesmosomes occur in the basal cell membrane. Later the intercellular spaces become very narrow, the microvilli are present in clusters. Pinocytotic vesicles, amniotic fluid vacuoles or other indications of amniotic fluid transport are to be found neither in the glycogen-rich peridermal cells, nor in the basal cells.
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  • 89
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    Cell & tissue research 125 (1972), S. 289-294 
    ISSN: 1432-0878
    Keywords: Accessory optic system ; Rat ; Blood vessels ; Extracellular space ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of capillaries were found in the medial terminal nucleus of the rat accessory optic system. Type one capillaries are surrounded by glial processes and lack a perivascular space, whereas the type two capillaries and arterioles show a distinct extracellular perivascular space often filled with collagen fibrils. An internal as well as an external basal lamina lines these spaces. No fenestration of the endothelium was observed.
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  • 90
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    Cell & tissue research 125 (1972), S. 415-431 
    ISSN: 1432-0878
    Keywords: Synapses ; Rat ; Cerebral cortex ; Glutaraldehyde/E-PTA ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synaptic junctions in intact rat cerebral cortex have been examined following glutaraldehyde fixation and phosphotungstic acid (PTA) staining. In the presynaptic ending the network has a hexagonal arrangement, while the dense projections are regularly placed along the presynaptic membrane. Cleft densities occupy the intracleft region. The postsynaptic thickening extends uninterrupted along the length of the junction. Qualitatively, the majority of junctions fall into the ‘discontinuous-continuous’ category, in which the internal coat of the presynaptic membrane together with its associated dense projections is discontinuous along the length of the junction, whereas the postsynaptic thickening is continuous. By contrast, a small number of junctions are ‘continuous-continuous’. In an attempt to analyze the junctions quantitatively, nine indices were measured. Histograms of the size distributions of seven of these appear to be bimodal, and from this it is concluded that two junction populations may be distinguishable on quantitative grounds. It is also shown that the distance separating dense projections at the presynaptic membrane is of the order of 10–15 nm. This surprisingly low value has consequences for current ideas on the relationship between synaptic vesicles and dense projections, and these are discussed at length.
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  • 91
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    Cell & tissue research 125 (1972), S. 404-414 
    ISSN: 1432-0878
    Keywords: Renal medulla ; Rat ; Interstitial ground substance ; Fixation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Interstitium des inneren Nierenmarkes von Ratten wurde nach Anwendung verschiedener Fixierungsarten und Versuchsanordnungen elektronenmikroskopisch untersucht. Neben Bindegewebszellen und kollagenen Fibrillen enthält der interstitielle Raum bandförmige, basalmembranartige Strukturen, in deren weiträumigen Maschen zwei weitere Komponenten, nämlich ein feingranuläres und feinfilamentäres Material sowie kontrastreiche, globuläre Partikel liegen. Diese beiden Formelemente stellen sich bei den verschiedenen Fixierungsarten und Versuchsanordnungen unterschiedlich dar. Bei der feingranulären und feinfilamentären Komponente handelt es sich wahrscheinlich um interstitielles Blutplasma. Diese Deutung wird gestützt durch die morphologische Ähnlichkeit mit dem Blutplasma der Blutgefäße, die unterschiedliche Darstellbarkeit nach Glutardialdehyd-und Formalinfixierung sowie durch die Befunde nach Gefäßperfusion und Nierenvenenstauung. Das Verhalten der globulären Partikel nach OsO4-Einwirkung steht in Einklang mit der schon früher gegebenen Interpretation als präzipitierte saure Mukopolysaccharide. Ihr elektronenoptisches Bild wird im Vergleich zur bekannten makromolekularen Struktur der Mukopolysaccharid-Protein-Moleküle diskutiert.
    Notes: Summary The interstitial ground substance in the inner medulla of the rat kidney is examined electron microscopically after fixation with various fixation agents and under different experimental conditions. The papillary interstitium contains besides interstitial cells and few collagen fibrils basement membrane like material and two other components, fine granular-fibrillar elements and globular particles with heavy contrast. The appearance of the two latter interstitial components varies according to the different fixation agents used and to the experimental conditions. The fine granular and fine fibrillar material surrounds the globular particles numerously after glutardialdehyde-fixation but scarcely after formaldehyde-fixation. It increases after renal vein occlusion, but is diminished or absent, if the kidney is rinsed bloodfree. These results allow to conclude that this material represents interstitial bloodplasma. The behaviour of the globular particles after OsO4-fixation agrees well with the earlier interpretation according to which they represent precipitated acid mucopolysaccharides. Their electron microscopic appearance is discussed in comparison with the known macromolecular structure of the acid mucopolysaccharides.
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  • 92
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    Cell & tissue research 125 (1972), S. 497-505 
    ISSN: 1432-0878
    Keywords: Chromatoid bodies ; Spermatozoa ; Cat ; Jensen's ring ; Centriole ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The first indication of differentiation of the Jensen's ring has been detected in an early stage of spermiogenesis of Felis catus Linné when the pair of centrioles takes up a position immediately beneath the plasma membrane. The chromatoid bodies appear in the early spermatid cytoplasm through the nuclear pore complex. In a more advanced stage, such bodies have been found in association with the striated columns, the distal centriole or the proximal part of flagellum and the Jensen's ring. As the spermiogenesis proceeds, the bodies have decreased their size and density, and finally disappear in mature spermatozoa. The chromatoid bodies seem, therefore, to share with the centriole the capacity to form the connecting piece. As a consequence of disorganization of triplet microtubules of the centriole, a noticeable material appears in the center of lumen of the centriole to be identifiable as a distinct precursor of the central pair of axonemal complex. Microtubules are first developed as the sheath of principal piece of the sperm flagellum, originating from the plasma membrane surrounding the axonemal complex.
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  • 93
    ISSN: 1432-0878
    Keywords: Hypophyse ; Quail ; Thyroidectomy ; Castration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé On compare l'ultrastructure et la localisation des phosphatases acides au niveau des cellules hypophysaires delta et beta, chez des Cailles mâles thyroïdectomisées et maintenues en photopériode courte ou bien castrées, puis placées en photopériode longue. On étudie en outre, dans ces deux cas, les effets d'injections de doses croissantes de thyroxine. La thyroïdectomie provoque la transformation des cellules delta en cellules de thyroïdectomie groupées en îlots à la périphérie du lobe céphalique. Ces cellules sont pauvres en phosphatases acides. La thyroxine (10 μg/j pendant 2 jours) provoque la régression de ces cellules et l'apparition de lysosomes. Les cellules beta ne sont pas modifiées par la thyroïdectomie. La castration-photostimulation stimule les cellules beta localisées dans le lobe céphalique. Elle provoque dans les deux lobes de la glande l'hypertrophie et la vacuolisation des cellules delta qui se distinguent des cellules de thyroïdectomie par la présence de nombreux lysosomes. La thyroxine freine simultanément l'activation des cellules delta et des cellules beta, en provoquant la formation de lysosomes, mais la dose efficace chez le mâle photostimulé (20 μg et 60 μg/j pendant 5 jours) est sans effet chez le castrat photostimulé (dose efficace 180 μg/j). Pour interpréter ces faits, on admet que les cellules delta, thyréotropes et les cellules beta, gonadotropes, seraient simultanément soumises à un contrôle freinateur des hormones thyroïdiennes et des stéroïdes mâles.
    Notes: Summary The ultrastructure and the localization of acid-phosphatase activity are compared in beta and delta pituitary cells of male Japanese quail, either thyroidectomized and maintained in short days, or castrated then put in long days. Moreover, in these two cases, the effects of brief treatments with increasing doses of thyroxine are studied. Thyroidectomy induces transformation of delta cells into “thyroidectomy cells” arranged in clumps at the periphery of the cephalic lobe. The acid-phosphatase activity of such cells is low. Thyroxine (10 μg per day for two days) causes regression of these cells and the appearance of numerous lysosomes. Beta cells are not modified by thyroidectomy. Castration and exposure to long days stimulate beta cells, localized in the cephalic lobe. It induces, also, in both pituitary lobes, hypertrophy and vacuolization of delta cells which differ from thyroidectomy cells by the presence of numerous lysosomes. Thyroxine in photostimulated quail inhibits both delta- and beta-cell stimulation and increases the frequency of lysosomes but the effective doses on males (20 μg or 60 μg per day for five days) are inactive on castrates, the response of which is obtained with 180 μg per day. In order to explain these data, a hypothesis is suggested: Thyrotropic delta cells and gonadotropic beta cells are both subject to a double inhibiting control by thyroid hormones and male steroids.
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  • 94
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    Cell & tissue research 123 (1972), S. 486-495 
    ISSN: 1432-0878
    Keywords: Pomatoceros triqueter ; Cytokinesis ; Surface folding ; New surface membrane ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The first cleavage division of Pomatoceros triqueter eggs is described. Time-lapse microcinematographic and electron microscopic studies revealed that, prior to division, the plasma membrane was folded into pleats. These were not present after division. This fact pointed to an unfolding of the plasma membrane which enabled it to cover the increased surface area resulting from cleavage. It is suggested that the pre-cleavage folds are derived from the membranes of the cortical granules, which continue releasing their contents into the perivitelline region following fertilization and first division. Filamentous material in the form of a band was present subjacent to the plasma membrane in the region of the furrow. The individual filaments of this band measure 5 to 7 nm in cross section, the dimensions being similar to those described for other kinds of dividing cells.
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  • 95
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    Cell & tissue research 124 (1972), S. 39-43 
    ISSN: 1432-0878
    Keywords: Ruminal epithelium ; Zonulae occludentes ; Goat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Pansenepithel besitzt in den tiefen Hornzellen, die an das Stratum granulosum grenzen, eine Barriere. Diese Barriere, die das Labyrinth der Interzellularräume gegen das Pansenlumen verschließt, ist mit Zonulae occludentes ausgestattet.
    Notes: Summary The deep horn cells of the goat ruminal epithelium, which border the stratum granulosum, form an important component of the epithelial barrier. This barrier of the intercellular labyrinth presents zonulae occludentes (tight junctions).
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  • 96
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    Cell & tissue research 124 (1972), S. 72-75 
    ISSN: 1432-0878
    Keywords: Erythrocytes ; Monkeys ; Malaria ; Junctional apparatus ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy of erythrocytes infected by the malarial parasite,Plasmodium falciparum, revealed electron dense, cone-shaped excrescences (∼40 mμ in height and ∼100 mμ in width) along the plasma membrane. These excrescences form focal junctions with the plasma membrane of reticular cells of the spleen. The resulting complexes appear to be responsible for sequestration of erythrocytes infected byP. falciparum in the spleen of the host.
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  • 97
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    Cell & tissue research 124 (1972), S. 72-75 
    ISSN: 1432-0878
    Keywords: Erythrocytes ; Monkeys ; Malaria ; Junctional apparatus ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy of erythrocytes infected by the malarial parasite, Plasmodium falciparum, revealed electron dense, cone-shaped excrescences (∼40 mμ in height and ∼100 mμ in width) along the plasma membrane. These excrescences form focal junctions with the plasma membrane of reticular cells of the spleen. The resulting complexes appear to be responsible for sequestration of erythrocytes infected by P. falciparum in the spleen of the host.
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  • 98
    ISSN: 1432-0878
    Keywords: Carotid body ; Biogenic amines ; Reserpine ; p-Chlorophenylalanine-methylester-hydrochloride ; Fluorescence microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß von p-Chlorphenylalanin-methylester-hydrochlorid (PCPA) und Reserpin auf die biogenen Amine des Glomus caroticum von Kaninchen wurde ultrastrukturell und fluoreszenzmikroskopisch untersucht. Die elektronenmikroskopische Analyse ergab keine eindeutigen Kriterien für arzneimittelinduzierte Veränderungen. Fluoreszenzmikroskopisch ließ sich nach Applikation von Reserpin eine ausgeprägte Senkung des Catecholamin- und Indolamin-Gehaltes und nach PCPA eine Abnahme des Serotonins erkennen.
    Notes: Summary The effects of p-chlorophenylalanine-methylester-hydrochloride (PCPA) and reserpine on biogenic amines of the rabbit carotid body were investigated ultrastructurally and by fluorescence microscopy. The electron microscopic analysis did not indicate significantly that structural changes result from treatment with reserpine or PCPA. Fluorescence microscopy indicated that PCPA lowered serotonin, and reserpine lowered both catecholamines and indolamines.
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  • 99
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    Cell & tissue research 124 (1972), S. 311-319 
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Neurovascular contacts ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the median eminence of the rat axons of the supraoptic-paraventricular-hypophyseal tract with elementary neurosecretory granules (150–200 mμ) traverse the internal zone. Terminals containing dense core vesicles 60–120 mμ in diameter end on the portal capillaries of the median eminence. A unique organisation of the primary portal capillaries is shown. Endothelial cells have many fenestrae. The pericapillary space has numerous extensions all of which represent a special zone around the endothelial tube. The fine structural organisation and function of the neurovascular contacts in the median eminence are discussed.
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  • 100
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    Cell & tissue research 124 (1972), S. 387-405 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Mouse ; Follicular cells ; Marginal cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Follicular cells in the mouse adenohypophysis were studied electron microscopically. These elements appear to be very similar to the marginal cells that delineate both sides of the hypophyseal cleft. The mouse differs from most other species in that the follicular cells in the pars distalis and the marginal cells look completely inactive in young, intact animals. This makes the mouse exceptionally favorable for correlating morphological changes in the cells of both types with changes in the physiological state of the animal. Different treatments applied in the present investigation all induced morphological reactions in the follicular and/or marginal cells; these reactions were generally similar. Thus, morphological changes in the follicular or marginal cells should be considered as general phenomena accompanying many changes in the physiological state of the animal, rather than as a specific result of the treatment applied. In three experiments, the follicular and marginal cells were involved in the digestion of waste material from other cells. It is suggested that the morphological changes in the other experiments should also be interpreted as signs of such an activity. In the pars tuberalis of the young, intact mouse the follicular cells may show characteristics that in the pars distalis are found only under experimental conditions. Therefore, the follicular cells in this part of the hypophysis are probably in an active state.
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