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  • 1
    Electronic Resource
    Electronic Resource
    Cell wall formation in zoospores of Allomyces arbuscula (1974)
    Springer
    Archives of microbiology 98 (1974), S. 147-158 
    Details
    ISSN: 1432-072X
    Keywords: Allomyces ; Zoospores ; Cell Wall ; Wall Formation ; Lomasome ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrastructural observations on encysting haploid zoospores of Allomyces arbuscula are presented with special reference to cell wall deposition. Multivesicular bodies are observed in the cytoplasm of zoospores 15 min after inoculation, lomasomes after 30 min and fine membrane profiles between the plasmalemma and the cyst wall are observed after 4 h indicating a possible system for secretion of cell wall components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425277
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  • 2
    Electronic Resource
    Electronic Resource
    The hypothalamo-hypophysial system of hypophysectomized rats (1974)
    Springer
    Cell & tissue research 155 (1974), S. 541-554 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysectomized rats ; Reorganized stalk ; Ultrastructure ; Salt load
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The reorganized stalk of hypophysectomized rats, either “intact” or subjected to a 6-day salt load, has been studied by light and electron microscopy. PAF-positive neurosecretory material is seen mainly in the periphery of the reorganized stalk, usually in 2–5 μ nerve swellings of animals operated two months before. Nerve swellings make contact with a dense capillary network. Three types of nerve fibres and their swellings are distinguished according to the size of elementary granules. Peptidergic A1 and A2 types contain granules with a maximum diameter of 170 and 130 nm respectively; monoaminergic B type fibres have granules of 100 nm in diameter. A1 type axonal swellings are the most numerous and can be tentatively divided into four subtypes according to their ultrastructure and relationships with capillaries and pituicytes. Swellings of types b and c, making direct contact with capillaries or pituicyte perikarya, usually contain few granules and numerous synaptic vesicles arranged frequently in clusters in the “active” zones. It is assumed that they are especially active in the release of peptide neurohormones. It is also hypothesized that in the hypophysectomized rats peptide neurohormones are released not only directly into the pericapillary space but also into the intercellular cleft, especially at sites of neuron-pituicyte junctions. Nerve swellings of type a, separated from the pericapillary space by thin pituicyte processes, usually contain numerous neurosecretory granules. It is suggested that vascular “end-feet” of pituicytes may somehow reduce neurohormone release. The depletion of PAF-positive material as well as the decreased granule content even after a salt load of only 1 per cent shows that the reorganized stalk is functional as a neurohaemal organ, but has a diminished hormone reserve. This, together with a primitive cytomyeloangioarchitecture speaks for morphological and functional imperfection of the reorganized stalk.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227014
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on the intercellular bridges between the oocyte and follicle cells in the lizard Acanthodactylus scutellatus hardyi (1974)
    Springer
    Anatomy and embryology 143 (1974), S. 239-254 
    Details
    ISSN: 1432-0568
    Keywords: Oocyte ; Follicle cells ; Intercellular bridges ; Lizard ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Intercellular bridges connect the oocyte with its surrounding follicle cells. 2. Fibrillar bundles and microtubules are oriented along the length of the bridge. Mitochrondria, endoplasmic reticulum, multivesicular vesicles and other cytoplasmic components are also present in this region. 3. This communication may be very important for the flow of nutrients necessary for the growth of the oocyte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00519868
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  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure of cleavage stages and preimplantation embryos of the baboon (1974)
    Springer
    Anatomy and embryology 147 (1974), S. 45-62 
    Details
    ISSN: 1432-0568
    Keywords: Baboon ; Cleavage stages ; Embryos ; Preimplantation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La structure et l'ultrastructure des embryons de babouin sont étudiées dans la période précédant l'implantation. Six stades du développement embryonnaire sont observés 2, 3, 4, 5, 7 et 8 jours après la date présumée de fécondation. Dans les 3 premiers cas, on compte respectivement 2, 8 et 24 blastoméres. A 5 jours, il y a 30 à 40 cellules et un nombre dépassant 60, ultérieurement. Des cellules trophoblastiques primitives se différencient à 7 jours et une cavité de segmentation en forme de croissant apparaît au 8 ème jour. La zone pellucide est toujours présente à 8 jours, la période de préimplantation semblant plus longue chez le babouin que chez l'homme. Des particules de type C sont décrites dans la zone pellucide et les espaces périvitellin et interblastomériques. La transformation des mitochondries, des changements dans la répartition des ribosomes, des corps multivésiculaires, pseudocristallins et figures myéliniques, des nucléoles et amas granuleux intra-nucléaires s'observent chez le babouin comme chez certains autres Mammifères; par contre, les faisceaux fibrillaires cytoplasmiques sont absents. L'étude des changements de l'ultrastructure provoqués par des hormones et drogues permettrait de mieux évaluer la nocivité de ces substances pendant les premiers stades du développement embryonnaire des Primates.
    Notes: Summary The baboon preimplantation stages were examined using light and electron microscopy. Six cases were studied at 2, 3, 4, 5, 7 and 8 days estimated fertilization age. The first 3 specimens were composed of 2, 8 and 24 blastomeres respectively. At 5 days, 30 to 40 cells were counted and more than 60 cells in later stages. Primitive “trophoblast cells” differentiate at 7 days and a crescentic blastocoele appears at 8 days. Shedding of the zona pellucida is not observed in the 7 and 8 day specimens. The preimplantation period is longer in the baboon than in man. C-type viruses are observed in the zona pellucida, in the perivitelline and interblastomeric spaces. Microvilli and caveolae cover the periphery of the baboon conceptus. As in many other mammals, transformation of the mitochondria, changes in the ribosomes distribution, multivesicular bodies, myelin figures, nucleoli and intranuclear clusters of granules are described in the baboon. Cytoplasmic fibrous strands are not present as in the mouse. Experiments on the influence of hormones and drugs on ultrastructural changes would help to evaluate the importance of biohazards during the early development of primates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317963
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  • 5
    Electronic Resource
    Electronic Resource
    The ultrastructure of the thin loop limbs of the mouse kidney (1974)
    Springer
    Anatomy and embryology 147 (1974), S. 1-18 
    Details
    ISSN: 1432-0568
    Keywords: Mouse kidney ; Thin limbs ; Ultrastructure ; Renal concentrating mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The thin limbs of the loops of Henle in the mouse kidney have been investigated by conventional electron microscopy. Resulting from light microscopic investigations, a distinction in the epithelia of short and long loops can be demonstrated. Ultrastructurally, the thin limbs (descending) of short loops are composed of a uniformly thin and simple epithelium. In contrast, long loops (thin descending and ascending) are composed of three different epithelial types which are representative of a distinctly more complex epithelial system. Two epithelial types were observed in the thin descending limbs of long loops and the third type was observed in the ascending thin limbs. Based upon these findings it is suggested that the thin descending limbs of short and long loops of Henle in the mouse kidney cannot perform the same functions in the renal concentrating mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317960
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  • 6
    Electronic Resource
    Electronic Resource
    The fine structure of cerebral blood vessels in chick embryo (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 277-285 
    Details
    ISSN: 1432-0533
    Keywords: Chick Embryo ; Brain ; Blood Vessels ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the blood vessels was studied in the developing brain of chick embryo. The blood vessels were present in the embryos first examined (4 days after incubation) and their number increased in subsequent stages. The endothelial cells were generally large and showed junctional complexes, many microvilli and a large number of cytoplasmic organelles. Many tubular bodies and coated vesicles were also present. The tubular bodies were sometimes noted near the Golgi apparatus, suggesting their origin from this organelle. The mitochondria in the endothelial cells were generally larger than those in the surrounding neuropil. An ill-defined basement membrane-like substance was noted outside some endothelial cells on the 11th day and well formed basement membrane was present in the vessels of 18 day old embryos. A complete subpial astrocytic basement membrane was present from the early stage studied (4 days).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00697010
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  • 7
    Electronic Resource
    Electronic Resource
    A comparison of the fine structure of small blood vessels in intracranial and retroperitoneal malignant lymphomas (1974)
    Springer
    Acta neuropathologica 27 (1974), S. 93-104 
    Details
    ISSN: 1432-0533
    Keywords: Malignant Lymphoma ; Blood Vessels ; Lymphe Node ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the blood vessels of an apparently primary intracerebral malignant lymphoma was compared with those in another malignant lymphoma in a retroperitoneal lymph node. The essential features of the blood vessels in both cases were the same. They resembled the blood vessels found in normal lymph nodes and were both distinctly different from those seen in normal brain. It was concluded that the direction of differentiation of the blood vessels which arise to nourish the neoplastic tissue is determined by the nature of the tumor rather than the vessels from which they originate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687160
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructure of cerebral vessels in chick embryo in lead intoxication (1974)
    Springer
    Acta neuropathologica 30 (1974), S. 287-294 
    Details
    ISSN: 1432-0533
    Keywords: Lead Toxicity ; Brain ; Cerebral Endothelium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of cerebral vessels was studied at various stages of brain development in chick embryos exposed to lead intoxication when they were 4 days old. The endothelial cells showed swelling of mitochondria, presence of many cytolysosomal structures, many tubular bodies, and coated vesicles. A few vessels showed attenuation on the lining endothelial cells. The significance of these morphological alterations are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00697011
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  • 9
    Electronic Resource
    Electronic Resource
    Concordance between morphological and biochemical estimates of fluid spaces in rat brain cortex slices (1974)
    Springer
    Experimental brain research 21 (1974), S. 299-314 
    Details
    ISSN: 1432-1106
    Keywords: Brain cortex slices ; Ultrastructure ; Fluid spaces ; Swelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A comparison was made between morphological and biochemical estimates of extracellular and intracellular fluid spaces in rat brain cortex slices incubated under different conditions. By light microscopy the periphery of the slices was found to be more swollen than the center; this regional difference was verified biochemically in unfixed tissue. The electronmicroscopic evaluation of intra- and extracellular fluid spaces was accordingly based upon findings in a preselected area. Due to intracellular penetration of inulin in rat brain cortex slices the biochemically, determined extracellular and intracellular spaces were obtained by compartmental analysis of the inulin space. The concordance between the biochemical and the morphological findings was good: Both methods showed that the extracellular space increased during the incubation to a considerable magnitude after one hr. and that this extracellular space was reduced by excess potassium, glutamate, anoxia or incubation at 0°. Under the same conditions the biochemically determined intracellular space was increased. This cellular swelling was confirmed morphologically and found to comprise mainly glia cells after exposure to excess potassium, predominantly neurons after incubation at 0° and both cell types after anoxia or addition of glutamate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235749
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  • 10
    Electronic Resource
    Electronic Resource
    Structure and function of cold receptors (1974)
    Springer
    Pflügers Archiv 352 (1974), S. 1-10 
    Details
    ISSN: 1432-2013
    Keywords: Thermoreceptors ; Cold Receptor ; Ultrastructure ; Receptor Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Afferent impulses were recorded from single fibers serving cold and warm receptors in the skin of the cat's nose. The receptors were carefully tested for specificity and the receptive fields localized under the microscope with a microthermode. Each single fiber served one spot-like receptive field. The field was marked without damaging the nerve ending by inserting two thin stainless steel wires into the skin on both sides of the receptor. Investigation of semithin and ultrathin serial sections by light and electron microscopy revealed beneath each cold spot a dermal papilla which contained a single small myelinated fiber dividing into a number of unmyelinated terminals. Near the epidermis the receptor branches leave their Schwann cell envelope, penetrate the basal lamina of the epithelium, and their tips are invaginated into the cytoplasm of the basal epithelial cells. The basal lamina of the epithelium fuses with that of the receptor axon. The receptor axons contain numerous mitochondria, glycogen particles and a filamentous receptor matrix with vesicles of various sizes. The described structures were absent beneath the warm spots. In addition to the cold receptors, Merkel cell neurite complexes and lamellated encapsulated endings were found that are known to be mechanoreceptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061945
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