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  • 1980-1984  (123)
  • 1980  (123)
  • Ultrastructure  (122)
  • Nuclear reactions
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 65-73 
    ISSN: 1432-041X
    Keywords: Nuclear migration ; Cleavage ; Microtubules ; Ultrastructure ; Gall midge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the eggs ofWachtliella persicariae the cleavage nuclei move relative to the surrounding ooplasm. This ‘active’ migration is caused by an organelle whose ultrastructure was studied throughout the mitotic cycle. It consists of a greatly enlarged polar cytaster derived from the mitotic apparatus, linked to the nucleus by 100 Å filaments. The microtubules of the cytaster were found only during periods of active nuclear migration, i.e., from the onset of anaphase to the early prophase of the next mitotic cycle. They are always solitary and follow the course of the astral rays, which are known to temporarily adhere to peripheral structures of the egg cell and to exert tractive forces. In contrast to the cytaster microtubules, the microtubules in the spindle are bundled and persist from early metaphase through late telophase. During ontogenesis the first migration cytaster is built up between 3 and 12 min after oviposition near the anterior egg pole, in the vicinity of the sperm nucleus. In non-inseminated eggs time lapse films show a migration cytaster to develop autonomously in a region free from nuclei, but it does not follow the normal path of the male pronucleus. In several cases the female pronucleus, which remains without a cytaster of its own, was observed to move to the cytaster generated in the absence of the male pronucleus. Whether or not it is adhering to a nucleus, the cytaster divides into two at the correct time, i.e, corresponding to the first cleavage division in fertilized eggs. In some non-inseminated eggs this type of ‘pseudocleavage’ has been observed to occur repeatedly, giving rise to an increasing number of anucleate cytasters.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 163-177 
    ISSN: 1432-041X
    Keywords: Yolk sac ; Ultrastructure ; Embryogenesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes at the ultrastructural level during germ band extension in the embryo ofDrosophila melanogaster are described. Cytoplasmic connections between cells and the yolk sac are present during initial cellular movements. At this time, a continuous system of microfilaments is present adjacent to the membranes in the connections and at the periphery of the yolk sac. As germ band extension progresses, this system becomes discontinuous, and microfilaments are apparent only in the immediate vicinity of the connections. Cytoplasmic connections are disassembled at approximately the midpoint of extension; at the same time, extensive membrane associations develop between germ band cells and between these cells and adjacent yolk sac membranes. Positioning and orientation of cytoplasmic connections suggest that the yolk sac, via these connections, is actively involved in the cellular movements of early germ band extension.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 160 (1980), S. 275-284 
    ISSN: 1432-0568
    Keywords: Adenohypophyseal rudiment ; Follicular cells ; Ultrastructure ; Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The epithelial rudiment of 4 day-old quail embryo adenohypophysis, cultivated in vitro under conditions allowing glandular differentiation, displays peripheral cells that progressively acquire follicular cell features. They elongate, develop numerous microvilli, junctional complexes, interlocking membranes and bundles of microfilaments. These follicular-like cells derive from peripheral epithelial cells that, in situ, become glandular. These results show that follicular cells can develop from undifferentiated cells. They undergo this pathway of development, in all likelihood, as a result of perturbations in their microenvironment.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 159 (1980), S. 277-288 
    ISSN: 1432-0568
    Keywords: Megakaryocyte ; Bone marrow ; Steel mice ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The megakaryocytes in the bone marrow of steel mutant mice (Sl/Sld) and their normal littermates (+/+) were studied by light and electron microscopy with special emphasis on their maturity and distribution in the hematopoietic cords. A higher percentage of megakaryocytes lying against the sinus wall, a higher percentage of the sinus perimeter covered by megakaryocytes and a higher percentage of large megakaryocytes were found in Sl/Sld mice than in +/+ mice. In addition, more large megakaryocytes as well as senile megakaryocytes were observed in the spleen of Sl/Sld mice than in that of +/+ mice. These observations suggest that more platelets are produced in Sl/Sld mice than in +/+ mice on the basis of per unit area of the marrow tissue. Heretofore, the fate of the senile megakaryocytes in the marrow was not known. However, in Sl/Sld mice senile megakaryocytes were often found entering the marrow sinuses from the hematopoietic cords. They were also seen in the lung and the spleen where degradation of senile megakaryocytes was observed. These observations suggest that senile megakaryocytes in Sl/Sld mice leave the marrow and are removed by the reticuloendothelial system outside the marrow.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 158 (1980), S. 167-178 
    ISSN: 1432-0568
    Keywords: Placenta (human) ; Villous stroma ; Intercellular junctions ; Endothelium ; Ultrastructure ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intercellular junctions within the villous stroma and the cytotrophoblastic layer of the human full term placenta were investigated using thin sectioning and freeze-fracturing. Numerous maculae adherentes (desmosomes) were found between the cytotrophoblast cells and the syncytiotrophoblast. This junction type was also seen connecting adjacent cytotrophoblast cells. Large gap junctions were frequently observed in contact areas of perikarya or at processes of adjacent fibroblasts. They often exhibited a peculiar pattern of their particles on the P-face of the membrane. Small rows of junctional particles were found on the P-faces of interconnected smooth muscle cells and gap junctions frequently bridged myoendothelial and interendothelial contact zones. The significance of the junctional complexes is discussed in relation to functional systems within the villous stroma of the human full term placenta.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 160 (1980), S. 11-27 
    ISSN: 1432-0568
    Keywords: Sertoli cells ; Rat ; Fetal and postnatal life ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sertoli cells have various functions: mechanical (creation of two compartments in the seminiferous tubules, migration of germinal cells), secretory (secretion of anti-Müllerian hormone, inhibin, androgen-binding-protein and estrogen) and phagocytic. We report an ultrastructural study of the rat Sertoli cell during maturation and consider possible correlations between the acquisition of certain morphological characteristics and certain functions. During fetal life, the Sertoli cell possesses differentiated zones of junction with the gonocytes and seems to have a role in the migration of the gonocytes towards the periphery of the seminiferous tubule. The Sertoli cell performs the phagocytosis of the gonocytes which degenerate during their migration, and seems to be the site of production of protein granules, whose presence can be related to the synthesis of anti-Müllerian hormone. After birth and before puberty, when the inclusions resembling secretory granules disappear, the Sertoli cell membranes in contact with spermatocytes II and spermatids differentiate, forming, through the differentiated junctional complexes, two compartments (adluminal and luminal) in the seminiferous tubules. Finally, they acquire the characteristics of active secretory cells, capable, in particular, of steroid synthesis.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 159 (1980), S. 289-305 
    ISSN: 1432-0568
    Keywords: Placenta (rat) ; Development ; Intercellular junctions ; Ultrastructure ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The differentiation of chorionic layers II and III and alterations of intercellular junctions within the developing placental labyrinth were investigated in rats. Between the 14th and 16th day of gestation, the trabecular structures of the labyrinth alter and increasing numbers of primary, secondary, and tertiary lamellae develop. Trophoblastic layer I remains multicellular. Layer III rearranges and cytoplasmic fusions result in a continuous cytoplasmic barrier intervening between the already syncytial trophoblastic layer II and fetal capillaries. Simultaneously, most of the “undifferentiated” cells within the labyrinth disappear. Thin sectioning anf freeze-fracturing reveal multiple images of intercellular junctions, particularly gap and tight junctions in the cellular and syncytial parts of layers II and III. Continuous and regularly arranged tight junctions occur as well as fragmented structures which are spaced irregularly. Gap junctions are occasionally found between the juxtasinusoidal regions of layers II and III on the 14th day. More often they occur within restricted areas near the center of the trabeculae, integrated within extensive tight junctional strands. Gap junctions increase in later stages of pregnancy and eventually become distributed between the interfaces of layers II and III in the primary lamellae.
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  • 8
    ISSN: 1432-0533
    Keywords: Skeletal muscle ; Senescence ; 65 to 89-year-old people ; Histopathology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Biopsies for histochemical and ultrastructural studies were taken from the M. vastus lateralis of 45 healthy sedentary men and women aged 65–89 years. With increasing age the histochemical reactions reveal changes in the fibre type distribution characterized by a decrease in the percentage and predominant atrophy of type II fibres. The most frequent changes in the oldest subjects are: targetoid fibres, type I fibre predominance, and type grouping phenomena; expressions of denervation. Myopathic alterations are observed unusually. Electron microscopic findings are characterized by myofibrillar disorder, streaming of Z line and rod formation, and dilatation and increase of sarcoplasmic reticulum. As the age increases, the fibres become richer in intracellular lipid droplets and lysosomes. Intramuscular microcirculatory alterations, consisting of arteriolosclerotic changes and increase in width of the capillary basement membrane, are also observed and discussed.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 51 (1980), S. 113-117 
    ISSN: 1432-0533
    Keywords: Peroxisomes ; Catalase ; d-amino-acid oxidase ; Glial tumors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphologically and cytochemically defined peroxisomes (microbodies) were demonstrated in a series of 11 human glial tumors. The cytochemical methods used were the diaminobenzidine method for catalase and a tetrazolium salt-phenozine methosulfate method ford-amino-acid oxidase. Ultrastructurally, the peroxisomes were found as single membrane limited organelles with a granular matrix. Marginal plates as well as continuities with the smooth endoplasmic reticulum could be demonstrated. Peroxisomes were found most abundantly in subependymal giant cell astrocytomas, to a lesser number in astrocytomas and least abundantly in glioblastomas.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 49 (1980), S. 225-230 
    ISSN: 1432-0533
    Keywords: Human pituitary adenomas ; Tissue culture ; Cell culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pituitary adenomas of 120 patients were investigated in tissue and in cell cultures. Under different conditions of culture, the biopsies revealed different rates of growth. In tissue cultures 66% of the samples could be propagated while tumour specimens explanted in cell suspensions proliferated in 80% of the cases. Attempts to establish subcultures were also more successful when specimens were put into cell cultures primarily. Further differences of growth characteristics were observed in connection with the histological types of the parent tissues. According to the old terminology cells of mixed type adenomas had the longest life-span both in tissue and in cell cultures. Considering the proliferative activity, this type of tumour could be most frequently subcultured. Concerning the relationship of different cell components of the biopsies it was proven that survival and proliferation of adenoma cells may occur without fibroblasts. The appearance of fibroblast-like cells in older cultures is a morphological manifestation of the senescence of the specific cell types. Qualitative features of cultured adenoma cells showed that on the basis of cytomorphological properties “chromophobe” samples could be separated from the other types. Cells of acidophil and mixed type growths had the capacity of developing in vitro various migratory shapes, while “chromophobe” cells did not possess this ability. The histological diagnoses made independently from cultures confirmed the tissue culture findings. Differences of in vitro characteristics correlated also with the ultrastructural features of the cultured adenoma cells.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 52 (1980), S. 157-159 
    ISSN: 1432-0533
    Keywords: Neurons ; Thalamus ; Inclusions ; Ultrastructure ; Myotonic dystrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intracytoplasmic cosinophilic inclusions were found by light microscopy in the thalamic neurons of 35 consecutive normal adult brains and in a case of myotonic dystrophy, but not in six newborn children, including one with myotonic dystrophy. Histochemical tests suggested a protein composition. Ultrastructurally, the inclusions were composed of stacks of parallel alternating dark and light rectilinear profiles not surrounded by a limiting membrane. Such inclusions are a virtually constant finding in the adult human thalamus and probably represent sites of neuronal protein storage.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 50 (1980), S. 81-83 
    ISSN: 1432-0533
    Keywords: Cerebral neuroblastoma ; Desmoplastic variant ; Dense core vesicles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A desmoplastic primary cerebral neuroblastoma originating in the frontal lobe of a boy who died at the age of 6 years contained dense core vesicles within the cytoplasm of neoplastic cells as evidence of neuronal differentiation. Sarcomatous transformation had occurred at the time of recurrence. At autopsy, he also had cerebrospinal and extraneural metastases.
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  • 13
    ISSN: 1432-0533
    Keywords: Aging ; Hypertension ; Blood-brain barrier ; Ultrastructure ; Blood vessels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study demonstrates that markedly different patterns of age-related changes in blood pressure and body weight occur among normotensive Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). In addition, a variety of age-related structural alterations occurred in the walls of arterioles, capillaries, and venules of the frontal cortex. These changes include: (1) an increase in the thickness of the vascular wall by deposits of collagen and basal lamina which, in some cases, extended into the surrounding neuropil; (2) the presence of a flocculent material in the adventitia of intracerebral arterioles; (3) vesicular inclusions in perivascular macrophages, pericytes and smooth muscle cells which were labelled with i.v. administered horseradish peroxidase (HRP); (4) fragmentation of smooth muscle cells; and (5) accumulation of lipofuscin-like pigments in perivascular glial processes. The hypertensive rats exhibited these changes, but they were more advanced and more widely distributed throughout the cerebral cortex. The aged hypertensive rats occasionally had large bundles of 10 nm diameter, intermediate filaments in the endothelial cells. Whereas no change in blood-brain barrier permeability to HRP was observed in the aged normotensive rats, all age groups of the hypertensive rats exhibited increased permeability to HRP in the initial segment of penetrating arterioles in laminae I and II of the cerebral cortex.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 51 (1980), S. 65-70 
    ISSN: 1432-0533
    Keywords: Morphometry ; Glial cells ; Portocaval anastomosis ; Ultrastructure ; Corpus striatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of astrocytes and oligodendrocytes was investigated in rats 10 days, 30 days, and 10 weeks after portocaval anastomosis (PCA). Cell and nuclear sizes were measured by planimetry on randomly sampled cells magnified×24,000. The volume fractions of mitochondria, glia fibrils, and lipofuscin granules were measured in astrocytes by electronic image analysis. The mitochondrial profile area distribution and oligodendrocyte mitochondrial content were likewise estimated. All PCA animals had an increased astrocyte cell and cytoplasmic area, and after correction for cytoplasmic edema all groups had an enhanced mitochondrial fraction and mitochondrial number. The mitochondrial sizes were increased in all PCA groups. The mitochondrial profile area distribution curves did not suggest more than one group of mitochondria. All PCA groups had increased fractions of lipofuscin granules and glia fibrils. The oligodendrocytes had a slight fall in cell, nuclear, and cytoplasmic area after 30 days of shunting, and the mitochondrial fraction was diminished. After 10 weeks of PCA, all changes were reversed to normal values. It is concluded that the astrocytes are the active cells in the brain metabolism of ammonium. The oligodendrocytes seem to be dependent on neuronal integrity and do not contribute to the brain ammonium metabolism. The increase in astrocyte lipofuscin granules content may be explained by a beginning neuronal loss.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 49 (1980), S. 43-49 
    ISSN: 1432-0533
    Keywords: Rat ; Peripheral nerve ; Macrophage ; Ultrastructure ; Histochemistry ; Acid phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cellular content of the endoneurium in peripheral nerves of normal adult rats was studied. Endoneurial cells with high light-microscopical activity of acid phosphatase were usually located close to blood vessels or near the perineurium. Cells with the ultrastructural appearance of macrophages showed the same distribution and accounted for 2–4% of the endoneurial cell nuclei profiles. These cells rapidly endocytosed carbon particles after endoneurial administration of colloidal carbon in vitro.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 49 (1980), S. 75-78 
    ISSN: 1432-0533
    Keywords: Lamellar bodies ; Rough endoplasmic reticulum ; Purkinje neurons ; Adenohypophysis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lamellar bodies are stacks of parallel cisternae of approximately regular spacing derived from ergastoplasm. Their occurrence was studied in various nervous and epithelial cells of different animal species in both normal and diseased subjects. This organelle appears to be, at least for some cell types, a normal cytoplasmic feature. The number of lamellar bodies increases in some pathologic conditions and when the cell metabolism is elevated.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 51 (1980), S. 249-250 
    ISSN: 1432-0533
    Keywords: Neurons ; Mitochondria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural study of the cerebral cortex and spinal anterior horns disclosed periodically repeating processes located in the envelope space or in the intracristal space of neuronal mitochondria. The alteration was observed in postmortem cases in which fixation was delayed either voluntarity or involuntarily, but was not present in postmortem or surgical specimens in which fixation was prompt. The change is interpreted as an artifact due to delayed fixation.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 58 (1980), S. 501-510 
    ISSN: 1432-1440
    Keywords: Primärer Hyperparathyreoidismus, klinische und klinisch-chemische Befunde ; Akuter Hyperparathyreoidismus ; Ultrastruktur ; Hypercalciämie ; Parathormonspiegel ; Primary hyperparathyroidism, clinical and laboratory findings ; Acute hyperparathyroidism ; Ultrastructure ; Hypercalcemia ; Parathormone, blood level
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In a series of 6 patients out of 47 cases with extrarenal hyperparathyroidism we investigated the clinical, laboratory and ultrastructural peculiarities of acute hyperparathyroidism. It was found that there are characteristic differences between both entities which, however, are fluid. Clinically more severe were neuromuscular psychiatric and mental signs. In the laboratory parameters PTH determined by radio-immunoassay and calcium were higher whereas hemoglobin was lower. The weights of the adenomas did not differ in both groups and this was also true for light microscopy findings. Electron microscopy revealed accelerated hormone extrusion and autodigestion of retrieved membrane material in the cases of acute hyperparathyroidism similar to characteristics of parathyroid cells stimulated by hypocalcemia in tissue culture.
    Notes: Zusammenfassung Bei 6 Kranken mit akutem Hyperparathyreoidismus werden klinische Befunde, Labordaten und Besonderheiten in der Ultrastruktur der Nebenschilddrüsen den Daten von 47 Kranken mit extrarenalen Hyperparathyreoidismus gegenübergestellt. Typische Unterschiede konnten aufgezeigt werden, die Übergänge sind aber fließend. Beim klinischen Verlauf waren neuromuskuläre Zeichen, psychiatrische und Störungen des Bewußtseins deutlicher in der ersten Gruppe. Beim Vergleich der Labordaten war radioimmunchemisches Parathormon höher in der akuten Gruppe und das Hämoglobin niedriger. Das Gewicht der Adenome und die lichtmikroskopischen Befunde waren nicht unterschiedlich in beiden Gruppen. Die elektronenmikroskopischen Studien des Adenomgewebes zeigten eine erhöhte Hormonausschüttung mit einer deutlichen Beschleunigung der Autodigestion von Membranmaterial. Diese Veränderungen entsprechen etwa denen, wie sie an Nebenschilddrüsengewebe in der Gewebekultur nach Stimulation durch Hypocalciämie gefunden werden.
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  • 19
    ISSN: 1432-072X
    Keywords: Claviceps purpurea ; Ultrastructure ; Development ; Sclerotium ; Oleosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of sclerotia of Claviceps purpurea was investigated by light and electron microscopy. During the first days after infection sterigma and conidiospores are formed. The spores show a moderately developed vacuolar system, they are thick walled and contain about 20% lipid (related to the cell volume) embedded in glycogen. The sterigma are cylindrical unicellular hyphae with electron dense cytoplasm and isolated strongly contrasted lipid droplets. In maturing sclerotia the hyphae become septated with increasingly thick cell walls and a large lipid content. The lipid forms small droplets in young cells, while in the mature sclerotium it occurs in the form of very large drops, occupying the major part of the cell. Simultaneously the composition of the lipid is changed. The mature cells have several nuclei. They are partially connected by osmiophilic substances, forming a network of intercellular spaces.
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  • 20
    ISSN: 1432-072X
    Keywords: Mating tube ; Microtubule ; Tremella ; Ultrastructure ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrastructure of the mating tube formed in yeast haplont of the heterobasidiomycete Tremella mesenterica was studied by electron microscopy. Cell wall of the mating tube emerged as evagination of the inner layers, rupturing outer layers of the mother cell wall. Comparison with budding cells suggested that the tube emergence place at bud scar and the process of tube emergence was the same as that of bud emergence. Electron transparent vesicles of 0.1 μm diameter were scattered in the cytoplasm of the mating tube. Nucleus-associated organelle was located at one side of the nuclear envelope which extended towards the mating tube. A few microtubules were detected in the mating tube, but their association with a nucleus was not clear. The cytoplasmic structure of the mating tube was discussed in comparison with that of hyphae of the filamentous fungi.
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  • 21
    ISSN: 1432-1106
    Keywords: Ventromedial thalamic nucleus ; Cerebellar degenerating boutons ; Ultrastructure ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Terminal degeneration of cerebellar afferents in the ventral medial thalamic nucleus (VM) was studied in cats at the ultrastructural level after uni- or bilateral lesions in the brachium conjunctivum (BC). To achieve discrete lesions within the BC, a new very accurate stereotaxic technique was used. Numerous large terminals belonging to a population of so-called LR boutons were observed degenerating in the VM. The boutons displayed a wide variety of degenerative changes. Some revealed the features of the classical neurofilamentous type of degeneration. Others, although containing a slightly increased number of neurofilaments, featured much more prominently large numbers of coated vesicle shells and heavy accumulations of a flocculent electrondense material. Degeneration in a third group of boutons similar to some extent to the light type of degeneration was characterized by tight clumping of enormously swollen or distorted synaptic vesicles within a light matrix. At later stages, however, all these boutons were believed to become shrunken and electron-dense since intermediate stages between the light- and dark-appearing boutons were observed. The degenerating cerebellar boutons formed asymmetrical synaptic contacts. Groups of 3 or 4 boutons terminated upon dendrites of projection neurons synapsing more frequently on spines than on dendritic stems. The synaptic contacts between cerebellar boutons and the vesicle-containing dendrites of local circuit neurons were encountered as often if not more than the contacts on projection neuron dendrites. Triads consisting of cerebellar boutons and dendrites of both types of neurons were observed very regularly. This synaptic arrangement provides the anatomical basis for the modification of cerebellar input in the VM by interneurons.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 134 (1980), S. 69-74 
    ISSN: 1432-1076
    Keywords: Achondrogenesis type I ; Ultrastructure ; Chondrocytes ; Cytoplasmic inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The light- and electron-microscopic structure of articular and costal cartilage in a case of achondrogenesis type I has been described. The most characteristic ultrastructural change in the chondrocytes was conspicuous dilatation of the rough endoplasmatic reticulum (RER) which contained amorphous electronopaque material. This change in the RER was accompanied by marked hypertrophy of the Golgi apparatus; the matrix was basically unchanged.
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  • 23
    Electronic Resource
    Electronic Resource
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    Virchows Archiv 389 (1980), S. 103-117 
    ISSN: 1432-2307
    Keywords: Gonadal dysgenesis ; H-Y antigen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The gonads of 4 phenotypically female individuals with XY chromosomal constitution and signs of virilisation were examined by light microscopy. Electron microscopic examination was also performed in two cases. Serological analysis of H-Y antigen titer yielded positive results. The matrix of the gonads is shown to be ovarian stroma, in which tubular and follicular structures are embedded. The epithelia of the follicles resemble granulosa cells of the ovary, the tubular epithelia are resemble Sertoli cells. Tubules and follicles both show extensive regressive changes. A varying number of Leyding cells/stroma lutein cells were found in each gonad. The different degree of development of testicular and ovarian structures in the dysgenetic gonads might be explained by a defect of the gonadal specific receptor for the H-Y antigen, this defect varying in time of occurrence, duration and severity.
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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 389 (1980), S. 287-305 
    ISSN: 1432-2307
    Keywords: Myeloproliferative disease ; Osteomyelofibrosis ; Bone marrow biopsy ; Blast crisis ; Ultrastructure ; Basophilic leukaemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinical and morphological findings are presented in two patients suffering from myelofibrosis and osteomyelosclerosis which terminated in an acute blastic crisis. Clinical follow-up data and light microscopy of the bone marrow however, revealed a chronic megakaryocytic-granulocytic myelosis (CMGM) with progression into myelofibrosis during the course of disease. In one patient the blastic transformation involved predominantly basophils, and in the other, neutrophils, with an accompanying abnormal proliferation of megakaryocytes in both cases. Electron microscopy of this cell population demonstrated remarkable atypicalities of the neutrophilic, basophilic and megakaryocytic cell lines. These abnormalities consisted of a nuclear-cytoplasmic asynchrony and a partial arrest of maturation, sometimes resulting in bizarre cell forms. Our investigations support the hypothesis of a mixed cellularity type of myelosis with a gradual and insiduous progression into osteomyelofibrosis/-sclerosis and a potential blastic crisis. In the evolution of blastic crisis all cell lines may be transformed, but with predominance of one population — basophils and neutrophils in our two cases — in addition to atypicalities of megakaryocytes.
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  • 25
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    Virchows Archiv 389 (1980), S. 307-324 
    ISSN: 1432-2307
    Keywords: Polycythemia vera ; Secondary polycythemia ; Histopathology ; Ultrastructure ; Cytogenetics ; Bone marrow biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Clinical and morphological studies including light microscopy, electron microscopy and karyotyping of the bone marrow, were performed on a total of 164 patients with polycythemic conditions. A final diagnosis was obtained from clinical findings and histopathology of plastic embedded core biopsies of the bone marrow including sequential examinations. 51 patients revealed a secondary polycythemia whereas 113 displayed polycythemia vera (P. vera). In this last group 83 cases have persisting P. vera. 30 showed a transgression towards chronic myeloid leukemia with or without accompanying myelofibrosis — osteomyelosclerosis (so called chronic megakaryocytic-granulocytic myelosis — CMGM). The histopathology of the bone marrow in P. vera revealed consistent alterations which are useful in distinguishing this disorder from secondary polycythemia (SP) and CMGM: depletion of iron storage, increased neutrophilic granulopoiesis but no gross atypia in maturation, polymorphism of megakaryocytes with conspicuous giant forms and dilatation and increased branchings of venous sinusoids. Electron microscopic findings were in agreement and showed further abnormalities of cytological maturation in the erythrocytic and granulocytic lineage. Cytogenetic studies in 27 non-treated patients with P. vera revealed the Philadelphia chromosomes in 2 cases, whereas in SP only minor chromosomal anomalies have been encountered in a few patients. It is concluded that histopathology of trephine biopsies of the bone marrow is an invaluable aid to establish a correct diagnosis, differentiating P. vera from the other potentially polycythemic disorders and helping to detect a possible progression towards leukemia at an early stage. Cytogenetic investigations may show early structural and numerical abnormalities of the karyotype and possibly precede a presumptive transgression towards myeloid leukemia (CMGM). A simultaneously performed histological and chromosomal examination of bone marrow samples is therefore desirable in each case of a polycythemic condition.
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  • 26
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    Virchows Archiv 389 (1980), S. 325-341 
    ISSN: 1432-2307
    Keywords: Polycythemia vera ; Myeloid leukemia ; Histopathology ; Ultrastructure ; Cytogenetics ; Survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Of 113 Patients with polycythemia vera (P. vera) who had been followed for the last 8 years, 30 cases (27%) developed myeloid leukemia with fibrosis of the bone marrow. Core biopsies of the bone marrow including sequential examinations in several cases revealed neoplastic proliferation of neutrophil granulopoiesis and an atypical megakaryopoiesis with accompanying fibrosis of varying degrees. These alterations were consistent with a subtype of chronic myeloid leukemia — the so called chronic megakaryocytic-granulocytic myelosis (CMGM) — and correspond to (agnogenic) myeloid metaplasia with osteomyelofibrosis/-sclerosis. 5 of those 30 patients showed spontaneous transgression into myeloid leukemia, none of them had received any ionizing radiation or cytostatic therapy. A blast crisis or so called acute leukemia in P. vera was seen only in one patient who was treated by an overdose of radioactive phosphorus and later evolved into osteomyelosclerosis with blastic transformation. These findings of a chronic leukemia or CMGM arising from P. vera was further confirmed by atypia of ultrastructure and particularly by our cytogenetic evaluation. Chromosomal studies showed a Ph′-chromosome to be present in 5 of 8 patients with CMGM and myelofibrosis. Clinical and statistical evaluation of survival times showed a median survival expectation of all P. vera patients of 15 years. Life expectancy of the patients who still displayed P. vera was more favorable than those cases with transformation into CMGM, disregarding any therapy. Transformation of P. vera into CMGM occurred about 8 years after the onset of disease and following transgression into leukemia, half of these patients were dead after 2.5 years. Our results demonstrate that P. vera represents a “panmyelosis” with an inherent malignant nature, or a neoplastic proliferation of all three cell lines. This concept is supported by several facts: atypia of cytological differentiation as observed by light- and electron microscopy of the bone marrow, chromosomal anomalies with aneuploidy and an infrequent Ph'-marker, spontaneous transgression into chronic myeloid leukemia or its subtype CMGM without relevant therapy and a clonal evolution as shown by enzymatic studies reported in the literature.
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  • 27
    ISSN: 1432-2307
    Keywords: Parathyroid carcinoma ; Tumour progession ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of parathyroid carcinoma in a 74-year-old female patient was studied by light and electron microscopy. The malignancy of the parathyroid tumour was confirmed by local recurrence and infiltration of adjacent structures. The tumour was composed of uniform chief cells without mitoses. Ultrastructurally, the cells were characterized by tortuous plasma membranes, numerous secretion granules, an extensive rough endoplasmic reticulum and lack of lipid vacuoles, all indicating hyperactivity, but not malignancy. At death, the autopsy revealed local recurrence of tumour tissue, but no distant metastases. Both light and electron microscopy showed that considerable dedifferentiation of the tumour tissue had occurred. The tumour cells were now characterized by a marked nuclear pleomorphism and a coarse clumping of the chromatin. The presence of secretion granules alone suggested a parathyroid origin. Thus, at death there was unequivocal histological evidence of a carcinoma, whereas no such diagnosis could be made from the early biopsy. The clinical course alone indicated the malignant nature of the lesion.
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  • 28
    ISSN: 1432-2307
    Keywords: Pituitary adenoma ; Prolactin ; Ultrastructure ; Immunohistochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fifteen cases of pituitary adenoma, 14 of which were associated with hyperprolactinemia, were studied by observation and granule morphometry of electron micrographs, immunohistochemistry and sequential observation of in vitro release with regard to hormone production, storage and secretion. Adenoma cells of 6 cases with marked elevation of plasma prolactin were sparsely granulated, showed characteristic ultrastrucures including the presence of small secretory granules, well developed Golgi and rough membranes, misplaced exocytosis, and positive or negative immunostaining for prolactin. These adenomas also showed vigorous release of the hormone into the circulation and/or culture medium. In vitro studies showed that negative immunostaining of adenoma cells did not preclude the production and secretion of the hormone. One densely granulated adenoma containing cells with numerous lactotroph type granules showed moderate release of prolactin into the circulation. In an acromegalic case associated with both high plasma growth hormone and prolactin, some cells were shown by immunohistochemistry to store both hormones. There were 4 adenomas which could not be shown to produce, store and secrete prolactin by any method available.
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  • 29
    ISSN: 1432-2307
    Keywords: Eosinophilic granuloma ; Frontal lobe ; Histiocytosis-X ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinical symptoms, pathological findings and surgical treatment of a case of primary frontal lobe eosinophilic granuloma are presented. Initially a frontal mass was detected that clinically seemed like a low-growth tumor. After operation, the histological, cytochemical and ultrastructural studies showed positive acid phosphatase, α-naftil-esterase, oil-red and PAS reactions of tumoral cells and the presence of rod-shaped bodies in proliferative histiocytes, all which confirmed the pathological diagnosis of eosinophilic granuloma. Other osseous or visceral histiocytosis-X signs were not observed. The patient remains asymptomatic after a postoperative follow-up of 2 years.
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  • 30
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    Virchows Archiv 389 (1980), S. 1-11 
    ISSN: 1432-2307
    Keywords: Soft tissue sarcoma ; Myofibroblasts ; Ultrastructure ; Host response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A series of 129 soft tissue sarcomas was examined ultrastructurally to determine in which neoplasms and to what extent myofibroblasts could be demonstrated. Twenty cases of fibromatosis and fasciitis served as controls. Myofibroblasts were identified in all 30 cases of malignant fibrous histiocytoma and all 4 cases of well-differentiated sclerosing liposarcoma. Though most numerous in areas of desmoplasia, in no instance did myofibroblasts constitute the dominant cellular constituent of either neoplasm. Myofibroblasts were identified with lesser frequency and in smaller numbers in fibrosarcoma, synovial sarcoma, malignant hemangiopericytoma and neuroblastoma. None were observed in a wide assortment of diverse sarcomas in which desmoplasia was not a feature. In comparison each lesion judged by light microscopy to represent either fibromatosis or fasciitis was composed principally of myofibroblasts. The demonstration of abundant myofibroblasts within a soft tissue lesion which has been subjected to wide sampling strongly suggests a benign proliferative process as opposed to a malignant neoplasm. It is hypothesized that myofibroblasts observed within collagenized regions of soft tissue sarcomas may constitute an expression of host response to neoplasia.
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  • 31
    ISSN: 1432-2307
    Keywords: Cortisol ; Myocardium ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male Wistar rats were treated with high cortisol doses for 1 week. The dose administered daily was 15 mg per animal in group 1 (7 animals) and 30 mg in group 2 (7 animals). 7 rats served as control group. After cortisol treatment the body weights decreased due to skeletal muscle catabolism and the heart weights increased. Morphometric analysis of the left ventricular posterior papillary muscles gave evidence that the increased heart weights resulted from an increased number of mitochondria and an increased volume of the cytoplasm, whereas the myofibrillar mass was not affected. The surface area of inner mitochondrial membranes (+cristae mitochondriales) per myofibrillar unit volume increased from 15.7 μ2/μ3 to 21.3 μ2/μ3 in group 1 and 21.4 μ2/μ3 in group 2. Ultrastructural changes indicating myocardial cell damage were absent. Similar quantitative results have been reported to occur in the early phase of cardiac overload. For elucidating the hemodynamic effects of glucocorticoid a second experiment was performed: 7 Wistar rats were treated with cortisol in the same way as group 1, 7 others of the same body weight served as control. The systolic arterial pressure was significantly elevated in the cortisol group. Though myocardial tissue is known to be able to accumulate large quantities of glucocorticoids our results indicate that the application of high cortisol doses for a short time does not produce myocardial cell damage and does not suppress the myocardial adaption to the glucocorticoid-induced hypertension, i.e. hypertrophy. On the contrary, it seems to be possible that the adaption process is itself facilitated or accelerated by the presence of high cortisol concentrations in the heart. This thesis is supported by the considerably higher relative heart weights in the cortisol groups and is in agreement with observations reported by other authors.
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  • 32
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    Virchows Archiv 387 (1980), S. 279-288 
    ISSN: 1432-2307
    Keywords: Pituitary ; Ultrastructure ; Hypophysectomy ; Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male Wistar rats were partially hypophysectomized and sacrificed at intervals of from 2 days to 1 year following the operation. The resected material was examined under the light microscope and the residual pituitary under the light and electron microscope. Neither regeneration nor an anatomical restoration of the adenohypophysis occurred even one year after partial hypophysectomy. An increased number of small chromophobe stem cells and juvenile chromophil cells were found in the residual pituitary. The amount of mitoses were not significantly increased. The ACTH, FSH and prolactin producing cells demonstrated electron microscopically distinct changes which were interpreted as signs of intensified activity. This can be seen as a “functional regeneration” to maintain vital pituitary function for the organism.
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  • 33
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    Virchows Archiv 387 (1980), S. 353-369 
    ISSN: 1432-2307
    Keywords: Granulosa cell tumors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural features of three granulosa cell tumors are presented. The neoplastic non-luteinized granulosa cells are characterized at sub-microscopical level by severely indented nuclei with prominent nucleoli, sparse to moderately developed predominantly granular endoplasmic reticulum, scanty lipids and lysosomes, small mitochondria with lamellar cristae and abundant intracytoplasmic filamentous material. The luteinized cells display a strongly developed tubular agranular endoplasmic reticulum and mitochondria with tubular cristae. These findings are compared with those of previous reports and discussed in relation to the well-known hormonal activity of these tumors.
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  • 34
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    Virchows Archiv 385 (1980), S. 283-291 
    ISSN: 1432-2307
    Keywords: Hodgkin's disease ; Myofibroblasts ; Ultrastructure ; Nodular sclerosis ; Host response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ten cases of nodular sclerosing Hodgkin's disease involving lymph nodes were studied by electron microscopy to determine the ultrastructural composition of the nodule-stromal interphase and the collagenized regions. In addition to a few lymphocytes, rare eosinophils and neutrophils, abundant filamentous and granular electron dense material, collagen fibers and myofibroblasts were observed in all instances. Since myofibroblasts possess contractile and synthetic properties, it is likely they contribute to the retraction and sclerosis which together represent one of the morphologic hallmarks of the disease. The dense fibrosis and contractile state of such tissue may constitute a beneficial host response to contain and limit local and vascular invasion by the neoplastic cellular population, thus contributing to the relative benignity of this form of Hodgkin's disease.
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  • 35
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    European archives of oto-rhino-laryngology and head & neck 229 (1980), S. 45-53 
    ISSN: 1434-4726
    Keywords: Vitamin A-Mangel bei jungen Ratten ; Ultrastruktur ; Akustische Sinnenzellen ; Ganglion spirale cochleae ; Vitamin A deficiency in young rats ; Ultrastructure ; Acoustic sensory receptor ; Ganglion cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Microscope studies of the inner ear in rats with chronic vitamin A deficiency have rendered contradicting results. In our electron microscope study of the sensory cells of the inner ear in young rats with vitamin A deficiency we found that the cuticle is missing in outer hair cells. In the inner hair cells the cuticle is subtotally lacking. Furthermore, we found changes in the reticular system of the intermediate zone and massive degenerative changes in the afferent nerve system including the ganglion cells of the ganglion spirale cochleae. These morphological changes together with the recent findings of high concentrations of vitamin A in Corti's organ support the hypothesis that the acoustic sensory receptors contain of functionally depend upon vitamin A.
    Notes: Zusammenfassung Histologische Untersuchungen über die Auswirkung eines chronischen Vitamin A-Mangels auf die Strukturen des Innenohres hatten widersprüchliche Ergebnisse gebracht. Nach einem sechswöchigen Vitamin A-Mangel bei jungen Ratten fanden wir in äußeren Haarzellen ein Fehlen der elektronendichten, homogenen Cuticula. In den inneren Haarzellen kam es ebenfalls zu einer deutlichen Auflösung der Cuticula. Weiter fanden wir eine Fragmentierung und Verminderung des reticulären Systems der Intermediärzone. Deutliche Degenerationszeichen fanden sich bei den afferenten Nervenendigungen und in den Ganglienzellen des Ganglion spirale cochleae. Die Ergebnisse weisen auf eine spezielle Bedeutung des Vitamin A für die Funktionsfähigkeit der Sinneszellen hin.
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  • 36
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    Archives of gynecology and obstetrics 230 (1980), S. 49-75 
    ISSN: 1432-0711
    Keywords: Ovarian Sertoli-Leydig cell tumors ; Ultrastructure ; Histogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ovarian Sertoli-Leydig cell tumors are rare, most of them being endocrinologically active and causing virilization. Their histogenesis and nomenclature are still under discussion. Six such tumors were identified in the Laboratory for Histopathology of the University Women's Hospital, Zürich. The clinical data as well as the macroscopic, microscopic and ultrastructural features of these tumors are analysed and discussed. In an attempt to clarify their histogenesis, the ultrastructural features of these tumors have been compared with those of two granulosa cell tumors as well as with those of a testis in a patient with testicular feminization. Our own results and a study of published data suggest that Sertoli-Leydig cell tumors arise from ovarian stroma. Because of their obvious morphological similarities to testicular structures they should be termed “gonadal stromal tumors of android type”.
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  • 37
    ISSN: 1432-0738
    Keywords: Ultrastructure ; Morphometry ; Ageing ; Pentachlorophenol ; Liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Altersabhängige Unterschiede im Reaktionsverhalten der Leber bei männlichen Wistarratten nach intraperitonealer Applikation von 30 mg technischem Pentachlorphenol (PCP) pro Kilogramm Körpergewicht über 15 Tage wurden feinstrukturell-morphometrisch ausgewertet. Neben einer altersabhängigen Erhöhung des relativen Lebergewichts und einer Abnahme des Körpergewichts konnten umfangreiche Alterationen an den Hepatocytenzellkernen und Zellorganellen festgestellt werden. Die Ergebnisse belegen, da β PCP neben Veränderungen an den Mitochondrien und Microbodies eine Proliferation der Membranen des glatten ER und eine Verminderung von Membranen des rauhen ER hervorruft.
    Notes: Abstract Age-dependent effects of technical pentachlorophenol (PCP) on male rat livers were investigated after a 15 day treatment with PCP, 30 mg/kg/d body weight. The liver tissues were investigated morphometrically at light and electron microscopical levels. Statistically significant alterations of nuclei and organelles of the hepatocytes were described.
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  • 38
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    Calcified tissue international 30 (1980), S. 27-34 
    ISSN: 1432-0827
    Keywords: Ultrastructure ; Calcium ; Cartilage ; Vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The potassium pyroantimonate technique was utilized for the selective subcellular localization of calcium in the mandibular condylar cartilage of 1-day-old rats. Electron dense calcium pyroantimonate precipitates were localized principally in mitochondria and at the cell membrane of the chondrocytes. In addition, small intracellular vesicles 0.1–0.2µm in diameter were observed in proximity to the cell membrane of chondrocytes of the mid-hypertrophic zone. The results suggest that these vesicles were being extruded from the cell into the extracellular matrix. Energy-dispersive analysis by X-rays confirmed that calcium is the principal cation of the electron-dense precipitates.
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  • 39
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    Archives of gynecology and obstetrics 230 (1980), S. 123-135 
    ISSN: 1432-0711
    Keywords: Clip ; Bleier-Clip ; Tube ; Histologie ; Sterilisation ; Ultrastruktur ; Clip ; Bleier clip ; Fallopian tube ; Histology ; Sterilization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A bilateral salpingectomy was performed at the time of vaginal hysterectomy in a pregnant patient sterilized 20 months earlier by application of Bleier clips to the fallopian tubes. Clip application to the left tube had been incomplete. Undisturbed tissue (left tube) and clipped tissue (right tube) were examined and compared by light and scanning electron microscopy. The segment of tube fully grasped by the clip had a completely detached lining epithelium with coarse and flattened mucosa, a loose stroma, and disorganized muscular bundles. The left tubal mucosa was normal, whereas the right tube was stenosed at the site of clip placement, with rigid walls and a 0.175 mm luminal diameter. With progressively greater stenosis toward the clip site, mucosal destruction increased. Polypoidal mucosal folds were seen, as well as fibrous adhesions between mucosal folds. These observations indicate that tissue damage is extensive enough after clip application to require excision of the damaged segment of tube and microsurgical re-anastomosis for reversal of sterilization.
    Notes: Zusammenfassung Das Untersuchungsgut, über welches hier eingehend berichtet wird, stammt von einer 37jährigen Schwangeren (8. Woche), bei welcher 20 Monate zuvor eine Sterilisation mit Bleier-Clips versucht worden war. Es ergab sich eine Indikation zur Hysterektomie mit bilateraler Salpingektomie, was uns erlaubte, die gewebliche Reaktion einer Tube, an der ein Bleier-Clip korrekt saß, mit der an der kontralateralen Tube, über welche die Schwangerschaft eingetreten war, zu vergleichen. Die Präparate wurden rasterelektronenmikroskopisch und anschließend an identischen Stellen desselben Blocks lichtmikroskopisch untersucht („post-scanning histology“). In der voll gefaßten rechten Tube war das luminale Epithel streckenweise von der Unterlage abgehoben, das Faltenrelief der Mucosa distal und proximal der Clipmarke vergröbert oder abgeflacht, das subepitheliale Bindegewebe aufgelockert und die Bündel der Muscularis auseinandergedrängt. Die nur partiell mitgefaßte und daher noch ausreichend durchgängige linke Tube war zwar stenosiert, jedoch abgesehen von Schwangerschaftszeichen ohne markante Veränderung des Epithels. In der durch der korrekt sitzenden Clip verschlossenen rechten Tube verengte sich die Stenose der Clipmarke trichterförmig von proximal wie von distal, ein solider Epithelstrang war lichtmikroskopisch jedoch durchgehend nachzuweisen. Schleimhautmikropolypen und narbige Überbrückungen des Faltenreliefs in unmittelbarer Nachbarschaft des korrekt sitzenden Clips veranschaulichen, ebenso wie die narbigen Veränderungen der Tubenwand, daß eine funktionsfähige Wiederherstellung der Tubenkontinenz nach Entfernung eines zur temporären Sterilisierung applizierten Bleier-Clip kaum anders als durch eine mikrochirurgische Reanastomosierung nach Resektion der narbigen Stenose erwartet werden kann.
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  • 40
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    Calcified tissue international 31 (1980), S. 93-108 
    ISSN: 1432-0827
    Keywords: Calculus ; Ultrastructure ; Apatite ; Transmission ; Scanning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Using transmission and scanning electron microscopy, we have studied the ultrastructure of a number of urinary calculi, mainly composed of calcium phosphate. Three fundamental kinds of calcium phosphates were detected: nonstoichiometric carbonate apatite, nonhexagonal octacalcium phosphate, and calcium-magnesium whitlockite. The influence that the organic matter, substitutions in the phosphate lattice of CO3 and Mg, and apatitic stoichiometry have on the ultrastructure of the calcium phosphate calculi has been detailed. An originating apatitic unity named U2 is assumed to be the responsible for all the different structures of calcium apatites appearing in renal calculi. On the basis of our observations, a mechanism whereby apatites grow is postulated; magnesium functions as an inhibitor for the growing mechanism.
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  • 41
    ISSN: 1432-2307
    Keywords: Congenital Nephrotic Syndrome of Finnish type ; Histochemical ; Placentomegaly ; Trophoblast basement membrane alteration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have studied the morphological aspects of a thirty-six week gestational age placenta in the Congenital Nephrotic Syndrome of Finnish type. The study, conducted with histological, histochemical, morphometric and ultrastructural methods, demonstrates the presence of primary disorders of placentation consisting of persistent embryonic villi, arrested ramification and chorionangiomatosis. The villous development is compatible with the first-second trimester of pregnancy. Vasculo-syncytial membranes are quantitatively increased. Histochemical findings document placental immaturity further: Perls' reaction was positive for the trophoblast basement membrane (this is normally not observed beyond the second trimester), Alcian Blue positivity at pH 1 was also evident and was observed in three month gestational age placentae and in controls. Periodic Acid Silver Methenamine and Thioaldehyde Fuchsin documented abnormal thickenings of the trophoblast basement membrane. Electron microscopic observation reveals that the trophoblast basement membrane is thickened. Osmiophilic bodies are distributed throughout the trophoblast basement membrane and also within the basement membrane like material. Abundant microfibrils are present in the villous stroma. Lamination of basement membrane like material is observed in a subendothelial position. On the basis of their findings and in conjunction with the data in the literature regarding biochemical alterations of renal glomerular basement membranes in Congenital Nephrotic Syndrome Finnish type, the Authors suggest that a primitive membranopathy forms the basis for this pathological condition.
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  • 42
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    Virchows Archiv 389 (1980), S. 27-41 
    ISSN: 1432-2307
    Keywords: Chondrosarcoma ; Clear-cell chondrosarcoma ; Glucosaminoglycans ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of clear-cell chondrosarcoma located in the upper end of the right femur of men aged 30 and 40 years are reported. The roentgenologic appearances suggested a chondroblastoma. Both patients are alive, one and four years after surgical removal of the tumor. Glucosaminoglycans were studied with cationic dyes at different pH, with and without pretreatment with testicular hyaluronidase, and with the Scott technique at the light-microscopic level. Ultrastructurally, the glucosaminoglycans were studied with the high iron diamine and dialyzed iron techniques and glycogen with the PATCH-method. Light-microscopically, the tumors were characterized by clear vacuolated cells with distinct cytoplasm boundaries and scattered multinucleated giant cells of osteoclast type. Histochemical studies at the light-microscopic level indicate the presence of chondroitin 4- and 6-sulphate but no keratosulphate. Ultrastructurally, the predominant clear-cells showed features characteristic for chondroblasts. The cytoplasm showed areas lacking organelles and containing a low-density, finely granular matrix. These areas are considered to correspond to the clear cytoplasmic vacuoles seen under the light microscope. Most of the organelles were seen in the perinuclear region. The irregular tumor cells formed delicate protruding cytoplasmic extensions, which delineated intercellular spaces appearing as vacuoles under the light microscope. The benign multinucleated giant cells had an ultrastructural appearance typical of osteoclasts. Histochemical analysis at the electron-microscopic level showed the presence of sulphated glucosaminoglycans in the intercellular matrix and in association with the cytoplasmic membrane. Glycogen and non-sulphated acid glucosaminoglycans were found within the cytoplasm of the clear-cells.
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  • 43
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    Virchows Archiv 389 (1980), S. 59-77 
    ISSN: 1432-2307
    Keywords: Ethanol ; Myocardium ; Ultrastructure ; Morphometry ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male Wistar rats were fed with ethanol for 33 weeks. Ethanol was administered in a liquid diet containing 33% of the calories as ethanol. In the control group ethanol was isocalorically replaced by glucose. Light and electron microscopic investigation of the hearts did not indicate significant structural abnormalities, in contrast to the results of some other groups. Nevertheless, morphometric analysis revealed considerable quantitative changes. The number of mitochondria was remarkably reduced and the volume of an average single mitochondrion nearly doubled, whereas the volume fractions of mitochondria and myofibrils were unaltered. The analysis of the mitochondrial subcompartments indicated a slight decrease of the surface area of inner mitochondrial membranes per unit volume of mitochondria and a slight increase of the volume fraction of the mitochondrial matrix space. Myocardial cell hypertrophy or atrophy were not observed. We believe that the mitochondrial changes are the expression of an impaired biogenesis of these organelles. The increased number of capillaries in the ethanol-fed group is possibly caused by functional ethanol effects which may be partly similar to effects of chronic hypoxia. Ethanol- or acetaldehyde-induced damage of heart mitochondria may play an important role in the pathogenesis of alcoholic cardiomyopathy.
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  • 44
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    European archives of oto-rhino-laryngology and head & neck 226 (1980), S. 161-176 
    ISSN: 1434-4726
    Keywords: Otosklerose ; Histochemie ; Ultrastruktur ; Lysosome ; Oxytalanfaser ; Otosclerosis ; Histochemistry ; Ultrastructure ; Lysosomes ; Oxytalan fibres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In a histochemical and electron microscopical study the pathogenesis of Otosclerosis was investigated. The morphological changes in the extra- and intracellular space indicated a complex metabolic disturbance of all tissue components. The observed chondrocytic chondrolysis stressed the role of the cartilage remnants in the otic capsule as an etiological factor. There was morphological evidence of a superimposed enzymatic defect.
    Notes: Zusammenfassung In einer histochemischen und ultrastrukturellen Untersuchung werden die pathologischen Bindegewebsveränderungen bei der Otosklerose analysiert. Die Erkrankung führt zu einer komplexen Schädigung aller Bindegewebskomponenten. Es finden sich morphologische Anhalte für einen Enzymdefekt, der dem initialen pathologischen Reiz aufgelagert sein kann. Die beobachtete chondrozytäre Chondrolyse unterstreicht die Bedeutung der Knorpelreste in der otischen Kapsel als pathogenetischen Faktor der Otosklerose.
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  • 45
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    European archives of oto-rhino-laryngology and head & neck 226 (1980), S. 239-250 
    ISSN: 1434-4726
    Keywords: Enchondrale Schicht ; Labyrinthknochen ; Ultrastruktur ; Vergleichende Anatomie ; Endochondral layer ; Labyrinthine bone ; Ultrastructure ; Comparative anatomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The endochondral layer of labyrinthine bone of dog (Canis f. intermedius Woldrich) is examined by means of light and transmission electron microscopy. The osteocytes of the fine-fibred, alamellar “embryonic skein bone” (Meyer 1927) are surrounded by a fibre-less matrix. They correspond to osteocytes in long bones. Some of them are producing microfibrils according to formation of preosseous tissue which is called “intraosseous osteogenesis” (Knese 1970). Others are characterized by signs of micropetrosis or indicate osteocytic osteolysis. In the perivascular mesenchym of some vessels giant cells are visible which according to their ultrastructural characteristics are identified as osteoclasts. The occurrence of an embryonic type of bone in endochondral layer of otic capsule throughout life is discussed considering oxygenation via perivascular canalizition as well as biomechanical aspects.
    Notes: Zusammenfassung Unseres Wissens ist dies die erste transmissionselektronenmikroskopische Untersuchung des normalen Labyrinthknochens. Hier wird die enchondrale Schicht beim Hund (Canis f. intermedius Woldrich) betrachtet, da menschliche Felsenbeine sich aufgrund postmortaler Veränderungen nicht für ultrastrukturelle Studien eignen. Im „zeitlebens embryonalen Strähnenknochen“ (Meyer 1927) sieht man Zellen, die in einem fibrillenfreien, perizellulären Hof unterschiedlicher Ausdehnung liegen. Diese entsprechen den Osteozyten in anderen Knochen. Einige dieser Zellen bilden Mikrofibrillen und sind zu einer „intraossären Osteogenese“ (Knese 1970) fähig. Andere Zellen bieten das Bild einer osteozytären Osteolyse. Auch kommt eine Mikropetrosis in nicht kanalisierten, perivaskulären Regionen vor. Im perivaskulären Mesenchym erkennt man vereinzelt Riesenzellen, die aufgrund ihrer Ultrastruktur als Osteoklasten zu bezeichnen sind. Das lebenslange Vorkommen des embryonalen Strähnenknochens in der Labyrinthkapsel wird unter Berücksichtigung biomechanischer Gesichtspunkte diskutiert. Dabei wird auch auf die perivaskuläre Kanalisierung des Strähnenknochens eingegangen.
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  • 46
    ISSN: 1432-2048
    Keywords: Boron ; Foliar nutrition ; Nuclear reactions ; Transport (boron) ; Trifolium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of white clover (Trifolium repens L.) is severely inhibited by boron starvation, but a foliar treatment with boric acid can transitorily alleviate the deficiency symptoms. The 10B(n ,α)7 Li nuclear reaction has been used to study boron transport in the plant after foliar application. More than 98% of the boron supplied remained at the point where it was applied to the leaves, and less than 2% was useful to the growth of the treated plant. This small “efficient” portion of boron was quite mobile. It was distributed to the different parts of the plant, then was transferred from the oldest parts to the newly formed leaves. Physiological and agronomical implications of these data are discussed.
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  • 47
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    Archives of dermatological research 267 (1980), S. 283-290 
    ISSN: 1432-069X
    Keywords: Allergic contact dermatitis ; Infiltrating cells ; Monocytes ; Lymphocytes ; Ultrastructure ; Allergische Kontaktdermatitis ; Infiltratzellen ; Monocyten ; Lymphocyten ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Art und Feinstruktur mononuklearer Zellen, die bei allergischer Kontaktdermatitis nach ungefähr 6 h in der Epidermis auftreten, wurden im Elektronenmikroskop untersucht. Es handelte sich um Monocyten und Lymphocyten, die in ungefähr gleicher Zahl auftraten. Die Ultrastruktur der Monocyten war die gleiche wie die normaler Monocyten im Blut. Offenbar in aktiver Bewegung, erweitern sie die intercellulären Verbindungen der Keratinocyten. Die Lymphocyten zeigten einen runden oder ovalen Kern mit einigem elektronendichten Cytoplasma, das Ribosomen und Polysomen enthielt, aber nur fallweise Mitochondrien und Golgi-Komplexe.
    Notes: Summary The kind and fine structure of mononuclear cells appearing in the epidermis at about 6 h of allergic contact dermatitis were examined by electron microscopy. They were monocytes and lymphocytes, the number being about equal. The ultrastructure of monocytes was that described for normal ones in blood, and apparently actively moving, streching the intercellular connections of the keratinocytes. Lymphocytes displayed a round or oval nucleus with some electron-dense cytoplasm which contained ribosomes and polysomes but only occasional mitochondria and Golgi complexes.
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  • 48
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    Archives of dermatological research 267 (1980), S. 275-282 
    ISSN: 1432-069X
    Keywords: Allergic contact dermatitis ; Epidermal cell changes ; Ultrastructure ; Allergische Kontaktdermatitis ; epidermale Zellveränderungen ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Frühe epidermale Veränderungen bei allergischer Kontaktdermatitis wurden im Elektronenmikroskop untersucht. Gesunde freiwillige Testpersonen wurden mit DNCB sensibilisiert und in der Folge Kontaktreaktionen hervorgerufen. Epidermale Zellveränderungen nach 3 h waren unter anderem: Auftreten kleiner Vakuolen mit oder ohne Membran, stellenweise Erweiterung des Intercellularraums und eine Veränderung des Tonofilaments in kurze, gehäufte Bündel. Nicht sensibilisierte Haut, auf die DNCB appliziert wurde, zeigte auch kleine Vacuolen mit oder ohne Membran. Monocyten drangen in den Intercellularraum ein, der nicht ausgedehnt wurde. Die benachbarten Tonofilamente der Keratinocyten blieben normal.
    Notes: Summary Early epidermal lesions of allergic contact dermatitis were examined by electron microscopy. Normal human volunteers were sensitized to DNCB, and contact reactions were elicited sequentially. Epidermal cell changes at 3 h included: the occurrence of small vacuoles with or without membrane, focal dilatation of intercellular spaces, and the alteration of tonofilaments into short, aggregated bundles. Non-sensitized skin to which DNCB was applied also showed small vacuoles with or without membrane. Monocytes infiltrated into the intercellular spaces which were not dilated, and the neighboring tonofilaments of keratinocytes remained normal.
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  • 49
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    Neurosurgical review 3 (1980), S. 151-158 
    ISSN: 1437-2320
    Keywords: Diffuse hypertrophy of the cerebellum ; Dysplastic cerebellar gangliocytoma ; Epilepsy ; Granule cell hypertrophy ; Hamartoma of the cerebellum ; Lhermitte-Duclos disease ; Megalencephaly ; Ultrastructure ; Diffuse Hypertrophie des Kleinhirns ; Dysplastisches Kleinhirn-Gangliozytom ; Epilepsie ; Granuläre Zellhypertrophie ; Hamartom des Kleinhirns ; Lhermitte-Duclos'sche Krankheit ; Megalencephalie ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über zwei Fälle von Lhermitte-Duclos'scher Erkrankung bzw. diffuser Hypertrophie des Kleinhirns berichtet. Histopathologisch handelt es sich dabei um umschriebene Dysmorphien des Kleinhirns, die so charakteristisch sind, daß sie bei chirurgischer Exploration vom bloßen Auge erkannt werden können. Die vergröberten, hypertrophen Kleinhirnläppchen heben sich zudem durch eine unterschiedliche Färbung vom normalen Kleinhirn ab (Fig. 1). An Stelle der Körnerschicht gibt es dicht beieinanderliegende, dysplastische Ganglienzellen verschiedenen Typs (Fig. 3), die myelinisierte Axone (Fig. 7) in die dadurch stark myelinisierte Molekularschicht schicken. Die Purkinjezellschicht fehlt, die Marklamellen sind stark verschmälert. Die Läsion wird als Hamartom aufgefaßt; klinisch kann sie als Raumforderung der hinteren Schädelgrube in Erscheinung treten. Die Mehrzahl der Patienten mit diffuser Kleinhirnhypertrophie haben zusätzlich andere gehäuft vorkommende Läsionen wie Megalencephalie, Schädelund Skelettanomalien, benigne und maligne extracerebrale Tumoren u. a. m. Bei dem ersten Fall handelt es sich um einen 39jährigen Mann, der neben der diffusen Kleinhirnhypertrophie ein megalencephales Gehirn (2320 g) hatte, und an einem metastasierenden Coloncarcinom ad exitum gekommen ist. Im Alter von 34 Jahren ist eine 540 g schwere Struma entfernt worden. Die Ganglienzellnatur der dysplastischen Zellen der Körnerschicht ließ sich anhand des Nachweises von Synapsen (Fig. 6) und großen Nisslschollen (Fig. 5) elektronenmikroskopisch beweisen. Bei dem zweiten Fall handelt es sich um eine 74jährige Frau, deren Kleinhirnläsion — wie im ersten Fall — klinisch nicht in Erscheinung getreten ist. Die Aetiopathologie ist nicht bekannt. Die organoide Struktur der cerebellären Läsion, die häufige Vergesellschaftung mit Megalencephalie und anderen Mißbildungen, sowie das Vorkommen von familiären Fällen macht es wahrscheinlich, daß es sich dabei um eine Entwicklungsstörung handelt. Die Lhermitte-Duclos'sche Erkrankung ist selten. Meines Wissens sind zur Zeit insgesamt 42 Fälle bekannt geworden.
    Notes: Summary Two cases of Lhermitte-Duclos disease or diffuse hypertrophy of the cerebellum are presented. This brings the total number of such cases reported in the literature to 42. Pathologically the disease is characterized by a circumscribed cerebellar lesion consisting of thickening of the cortex with closely packed dysplastic ganglion cells in the granular layer and with large myelinated axons in the molecular layer. Purkinje cells are missing and the central white matter is greatly reduced. The first patient, a man 39 years of age, had, in association to the cerebellar lesion, a megalencephalic brain (2320 g). He had suffered from epilepsy since he was 24-years-old and died with metastasizing colon carcinoma. An electron microscopic study of the cerebellar lesion disclosed perikarya containing large amounts of rough endoplasmic reticulum, cell processes filled with coated and dense core vesicles. In addition, there were numerous enlarged myelinated axons in the molecular layer. The second patient, a woman 74 years of age, had a small area of diffuse hypertrophy of the left cerebellar hemisphere measuring one centimeter in diameter. Specific symptoms were very scant in the first case and absent in the second one indicating a very slow evolution — if any — of the disease process. The etiology and pathogenesis remain unknown. However, the organoid structure of the lesion, the frequent association of megalencephaly and other congenital abnormalities, and the occurrence of familiar cases would favor the disease being basically a developmental disorder.
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  • 50
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    Parasitology research 63 (1980), S. 33-46 
    ISSN: 1432-1955
    Keywords: Parorchis acanthus ; Redia ; Ultrastructure ; Migration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Rediae ofParorchis acanthus were examined by scanning electron microscopy and the ultrastructure of the surface related to migration through the digestive gland ofNucella lapillus. The median ventral birth papilla, ventro-lateral processes, and posterior papilliform process, of young active rediae, apparently serve to anchor the body during migration. The honeycomb-like apex of the birth papilla and ventro-lateral processes may be a strengthening device. Uniciliate sensory receptors around the mouth, on the birth papilla, and posterior terminal papilla are probably touch receptors or chemoreceptors concerned with feeding and orientation during migration. After the formation of the birth pore, and with increase in size and in the number of contained cercariae, the redia becomes less active, loses its characteristic shape, and is eventually immobile.
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  • 51
    ISSN: 1432-1955
    Keywords: Ultrastructure ; Microsporidia ; Simuliidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract During an investigation of the parasites of simuliid larvae in a defined area in Southern Germany six species of Microsporidia were found. These parasites infect larvae of six different species of Simuliidae. Using light and scanning electron microscopic techniques the microsporidians were identified asAmblyospora bracteata, Thelohania fibrata, T. varians, Pleistophora multispora, P. simulii, andP. debaisieuxi. The arrangement of membranes in the cyst as well as the surface structure of the spores are described.
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  • 52
    ISSN: 1432-1955
    Keywords: Schistosoma mansoni ; Mother sporocyst ; Daughter sporocyst ; Biomphalaria pfeifferi ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The development of the mother sporocyst and the differentiation of the daughter sporocyst ofSchistosoma mansoni inBiomphalaria pfeifferi are described. The tegumental structure of the mother sporocyst, consisting of an outer layer connected to internally situated nucleated cell bodies, forms extensions which enwrap the germinal cells. The parenchyma cells, in which the germinal cells were embedded before, degenerate. When daughter sporocyst embryos develop from germinal cells they are enveloped by a primitive epithelium which is formed by fusion of the extensions of the tegumental structure of the mother sporocyst. Somatic cells located peripherally in the developing daughter sporocyst expand and coalesce beneath the primitive epithelium to form the future outer layer of the tegumental structure of the daughter sporocyst. The primitive epithelium degenerates, the newlyformed layer looses its nuclei, and becomes connected to internally situated nucleated cell bodies. Further developments in the tegumental structure of the daughter sporocyst include the formation of microvillus-like projections, a surface coat, spines, and a basement membrane.
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  • 53
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    Parasitology research 63 (1980), S. 233-239 
    ISSN: 1432-1955
    Keywords: Siphonaptera ; Leptomonas ; Ultrastructure ; Cysts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Ultrastructural studies onLeptomonas ctenocephali ofCtenocephalides canis andLeptomonas species ofOrchopeas h. howardi andPalaeopsylla m. minor have demonstrated the presence of characteristic round and oval parasites with a regularly indented plasma membrane. Such forms were found only as unattached parasites in the lumen of the pylorus, hindgut, and rectum amongst parasites which showed a normal kinetoplastid plasmalemma. The plasmalemma indentations are regular in their distribution around the periphery of the parasite, being separated usually by a fixed number of subpellicular microtubules in each “cyst-like form”, some subpellicular microtubules are displaced from the periphery at the point where the plasmalemma is indented furthest into the cytoplasm. It is suggested that these forms meet the criteria necessary to be characterised as “cyst-like forms” despite the apparent absence of a true cyst wall.
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  • 54
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    Parasitology research 64 (1980), S. 1-15 
    ISSN: 1432-1955
    Keywords: Intersexuality ; Pedicel of antennae ; Chironomus ; Limnomermis rosea ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der normale Bau der Scolopidialorgane in den Pedicelli der Antennen vonChironomus entspricht dem vonAedes, mit Ausnahme folgender Besonderheiten: a) Der Geschlechtsdimorphismus des Organes ist ausgeprägter als beiAedes. b) Das Pedicelluslumen ist lateral und ventral größer als medial und dorsal. c) Der Bau des Geißelgelenkes ist einfacher, die innere Pedicelluswand massiv. d) Die Spangen des männlichen Pedicellus sind abwärts gebogen, die Scolopidien des proximalen Ringes setzen von oben und unten an den Spangen an, 2–4 der unteren Scolopidien jeder Spange haben größeren Durchmesser. Die Scolopidienzahl im proximalen Ring der ♀ ist viel geringer als beiAedes. e) Das Zentralorgan ist bei beiden Geschlechtern gleich, seine Scolopidien entsprechen Typ D vonAedes (Boo und Richards 1975a, b). Bei ♂ vonC. anthracinus Zett., die vonLimnomermis rosea Hagm. parasitiert sind, entspricht der Pedicellus völlig dem normaler und parasitierter ♀ (Tabelle 1). Werden ♂ vonC. riparius Meig. oderC. luridus Str. mit dem gleichen Parasiten infiziert, so kann der Pedicellus intersex abgewandelt sein: Der Grad der distalen Einsenkung, der Bau des Flagellum-Pedicellus-Gelenkes, die Spangenzahl und die Scolopidienzahl im proximalen Ring können offenbar alle Zwischenstufen zwischen männlicher und weiblicher Ausprägung erreichen. Der Übergang männchenähnlicher und weibchenähnlicher Bereiche in solchen Pedicelli erscheint abrupt. Die Ultramorphologie der Scolopidien bleibt vom Parasiten unbeeinflußt.
    Notes: Abstract The normal morphology of the scolopidial organs in pedicels ofChironomus antennae corresponds to that ofAedes, with the following exceptions: (a) The sexual dimorphism of the organ is more pronounced than inAedes. (b) The lumen of the pedicel is larger at its lateral and ventral side than at its median and dorsal side. (c) The construction of the flagellar side than at its median and dorsal side. (c) The construction of the flagellar prongs in male pedicels are directed downwards. The scolopidia of the proximal ring are attached to the upper and lower side of the prongs, 2–4 of the lower scolopidia of each prong have a greater diameter. The number of scolopidia in the proximal ring of females is much less than inAedes. (e) The central organ is identical in both sexes, its scolopidia correspond to type D ofAedes (Boo and Richards 1975 a, b). Pedicel structures inChironomus anthracinus males parasitized byLimnomermis rosea are identical to those of normal and parasitized females (Table 1). IfC. riparius orC. luridus males are parasitized by the same nematode, pedicels are often intersexual: The degree of the distal depression, construction of the flagellar articulation, number of prongs, and number of scolopidia in the proximal ring may attain all intergrades between maleness and femaleness. The transition between male- and female-like parts of the pedicel is abrupt. The ultramorphology of the scolopidia, however, is not influenced by the parasite.
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  • 55
    ISSN: 1432-1955
    Keywords: Cestoda ; Proteocephalus tidswelli ; Ultrastructure ; Microtriches
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Ultrastructural observations on adultProteocephalus tidswelli revealed a marked microtrichial polymorphism. Structural and dimensional variations of microtriches between different regions of the strobila and scolex, as well as within the same region, were observed. The authors suggest that microtriches are involved in a diversity of functions, and possible functional activities are discussed.
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  • 56
    ISSN: 1432-1955
    Keywords: Flagellates ; Spironucleus ; Mouse ; Ultrastructure ; Systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using light and electron microscopy, we studied the ultrastructure ofSpironucleus muris (syn.Hexamita muris) from spontaneously and experimentally infected normal and athymic mice. Kinetosomes and cytoskeletal fibers arranged in two-fold rotational symmetry are similar to the speciesSpironucleus elegans from amphibians. Taxonomic proposals and a possible evolutionary scheme for diplomonad genera accepted at the last International Congress of Parasitology are given. The genusHexamita should be divided into two new genera:Hexamita (usually free-living) andSpironucleus (exclusively parasitic). We consider previous descriptions of hexamitiasis in rodents as dealing with spironucleosis. We distinguish a fresh and an old cyst of the parasite on the basis of structure, light refraction, location in the host, and infectivity. The transition from a fresh to an old cyst paralles the dessication of feces. The trophozoites can damage the microvilli and penetrate into the epithelium. We explain the differences in findings concerning intestinal lesions and forms of the disease (from acute to chronic to latent) by differences in the virulence of different parasite strains and by differences in inherent host resistance.
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  • 57
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    Parasitology research 62 (1980), S. 63-74 
    ISSN: 1432-1955
    Keywords: Insect salivary gland ; Trypanosoma rangeli ; Penetration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Ultrastructural studies of the mechanism of penetration of the salivary gland of the reduviid bugRhodnius prolixus byTrypanosoma rangeli showed that trypanosomes from the haemocoele penetrate the outer “membranes” of the gland flagellum foremost, disrupting the inner layers, to pass between the muscle cells to reach the gland cell basement membrane. This latter is also penetrated flagellum foremost, the parasite invaginating the gland cell plasmalemma beneath, to create a vacuole in which the trypanosome crosses the gland cells to reach the central lumen, often only losing its containing vacuole just before leaving the cell. The structure of the outer “membranes” surrounding the salivary gland appeared similar to, and often actually part of, the basement membrane of the gland cells. These outer “membranes” were found to enclose large numbers of multinuleate “giant form” trypanosomes, whose significance is as yet unknown, but could perhaps represent a stage in the life cycle of the parasite where genetic interchange could take place.
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  • 58
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Neurosecretion ; Ultrastructure ; Neurophysin ; Lizard
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The supraoptic (SON) and paraventricular (PVN) nuclei of the lizard Liolaemus cyanogaster c. were studied by use of histochemical, immunocyto-chemical and electron microscopic methods. The immunofluorescence staining for neurophysin was applied to methacrylate-embedded material before and after treatment of the sections with urea and trypsin. Pseudoisocyanine was applied to sections previously used for immunocytochemistry. The ultrastructural study showed that the SON and PVN neurons possess neurosecretory granules (nsg), distributed throughout the perikaryon, and large (2 to 12 μm) electron-dense droplets located within dilatations of the cisternae of the rough endoplasmic reticulum. Whereas the perikaryon (nsg) and the secretory droplets are stainable with pseudoisocyanine, only the former displays immunoreactivity for neurophysin. However, after treating the sections with urea and trypsin, the same secretory droplets become immunoreactive. It is suggested that the secretory droplets are sites of storage for the precursor of neurophysin, and that the tryptic digestion either triggers its conversion into neurophysin or exposes its immunoreactive sites. Based on the ultrastructure and the histochemical behavior of the secretory droplets, it is also postulated that they contain, in addition to peptides, a glycoprotein component.
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  • 59
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    Cell & tissue research 207 (1980), S. 499-509 
    ISSN: 1432-0878
    Keywords: Mast cells ; Granulocytes ; Lymphoid cells ; Ultrastructure ; Cloaca ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Motile cells (mast cells, granulocytes, lymphoid cells) are described in the mucosa of the cloacal urodaeum and proctodaeum of the female domestic fowl. Diffuse lymphoid tissue with lymphatic nodules occurs in the urodaeum at the ureteral ostium. Small local aggregations of lymphoid tissue can be observed in the mucosa of the proctodaeum. Cells originating from these sites penetrate the basal lamina of the epithelium and are then found between the epithelial cells. In the subepithelial layers the motile cells sometimes are in contact with each other. Mast cells (tissue basophils) form contact zones, resembling desmosomes or half desmosomes, with smooth muscle cells. In the mast cells three types of granules can be distinguished. Their ultrastructure is discussed in comparison with that in similar cells of the guinea pig.
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  • 60
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    Cell & tissue research 208 (1980), S. 85-98 
    ISSN: 1432-0878
    Keywords: Pars intermedia ; Stellate cell ; Macrophage ; Ultrastructure ; Phagocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an attempt to study further the stellate cell and its functions, the ultrastructure of this cell type in the neurointermediate lobe of the bullfrog, Rana catesbeiana, was examined in both organ and dissociated-cell culture. The cytoplasmic activity of stellate cells from neurointermediate lobes incubated 3 1/2 or 5 1/2 h was greater than that of those in vivo. Mitochondria and bundles of cytoplasmic filaments were numerous, in addition to prominent, well-developed Golgi complexes with associated vesicles. The most striking ultrastructural feature was the presence of phagocytic vacuoles that contain cellular debris. The stellate cells were seen to form cytoplasmic processes that phagocytosed this extracellular debris identifiable as belonging to the secretory cells of the pars intermedia. The stellate cells from the dissociated-cell preparations were also seen to contain debris within phagocytic vacuoles. In those neurointermediate lobes transplanted for 3 1/2 to 4 days into the anterior chamber of the eye, the stellate cells demonstrated similar phagocytic ability, but the phagocytic vacuoles contained material that seemed to be at a later stage of degradation. In all three of these conditions, the stellate cells were not seen to release this cellular debris nor were they seen to undergo cell division. These glial-like stellate cells of the pars intermedia acted as macrophages in all three of these experiments. There is now, therefore, a need to determine under what conditions, if any, these stellate cells function in vivo as macrophages.
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  • 61
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    Cell & tissue research 208 (1980), S. 123-133 
    ISSN: 1432-0878
    Keywords: Lesioned axons ; Ultrastructure ; Crayfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distal stumps of severed medial giant axons (MGAs) and of non-giant axons (NGAs) in the CNS of the crayfish Procambarus clarkii show long-term (5–9 months) survival associated with disorientation of mitochondria and thickening of the glial sheath. However, the morphological responses of the two axonal types differ in that neither the proximal nor the distal stump of severed MGAs ever fills with mitochondria as is observed in some severed NGAs. Furthermore, the adaxonal glial layer never completely encircles portions of MGA axoplasm as occurs in many severed NGAs; in fact, ultrastructural changes in the adaxonal layer around severed MGAs are often difficult to detect. No multiple axonal profiles are ever seen within the glial sheath of the proximal or distal stumps of severed MGAs whereas these structures are easily located within severed NGAs.
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  • 62
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    Cell & tissue research 210 (1980), S. 21-32 
    ISSN: 1432-0878
    Keywords: Eyespots ; Photoreceptor ; Chemoreceptor ; Turbellaria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The eyespots of Microstomum lineare were studied by electron microscopy, light microscopy, and fluorescence microscopy. Each eyespot consists of two ciliary photoreceptor cells shielded by pigment cells and additional sensory cells. The photoreceptor cells are characterized by a distal intracellular cavity lined with 50–100 interwoven cilia. The other sensory cells are of two ultrastructurally different types, one with long cilia predominating and the other with balloonlike cilia. The pigment cells, which envelop processes of the sensory cells, contain pigment vacuoles varying in size and content and give a bright red fluorescence by the Falck-Hillarp method. The eyespots are suggested to perform a dual function as photoreceptors and chemoreceptors. The evolutionary significance of ciliary photoreceptors in Turbellaria is discussed.
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  • 63
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    Cell & tissue research 210 (1980), S. 85-94 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Domestic fowl ; Preoptic area ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Numerous secretory parvocellular perikarya were found in the preoptic region of the domestic fowl (Gallus gallus). The dense-core secretory vesicles belong to two categories: vesicles with a diameter of (i)80–90 nm and (ii) 110–140nm. Scattered magnocellular elements display larger dense-core granules. The parvocellular neurons form unit-like clusters, showing also zones of direct apposition of neuronal membranes. The surrounding neuropil is rich in synaptic structures, formed by at least three types of axon terminals, distinguishable on the basis of vesicular morphology. These observations confirm the findings in other avian species. The hypothetical function of this system of peptidergic neurons in the rostral hypothalamus of birds is discussed.
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  • 64
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    Cell & tissue research 210 (1980), S. 121-132 
    ISSN: 1432-0878
    Keywords: Glycoproteins ; Ultrastructure ; Tunicamycin ; Colonic epithelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glycoproteins are associated with several structures of colonic absorptive cells of the mouse. These include the cell coat, Golgi apparatus and vesicles that transport the glycoproteins from the apparatus to the cell surface (Michaels and Leblond 1976). In many in vitro systems, the antibiotic tunicamycin inhibits the glycosylation of asparagine residues yielding carbohydrate-poor glycoproteins. In the present in vivo study, tunicamycin was injected into mice. The murine colonic epithelial cells were prepared routinely for electron microscopy and cytochemistry. Cells from the experimental and control animals were similar morphologically. However, staining by the periodic acid-chromic acid-silver methenamine technique, revealed differences in the distribution of glycoproteins. In animals that received the higher dosages of tunicamycin there was a substantial reduction in silver staining in both the Golgi apparatus and the vesicles of colonic epithelial cells compared to these structures in cells of identically treated control tissues, whereas the staining over the cell coat was not significantly altered. Possible explanations for the staining of the cell coat in the treated animals were provided in the text. This report demonstrates the feasibility of using tunicamycin in vivo and detection of the changes obtained by the silver methenamine method.
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  • 65
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    Cell & tissue research 211 (1980), S. 391-403 
    ISSN: 1432-0878
    Keywords: Ocelli ; Dinopid spider ; Ultrastructure ; Optics ; Evolution of nocturnal eye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The posterior median (pm) eyes of the dinopid spider Menneus unifasciatus L. Koch are described and compared with the pm eyes of Dinopis, which are highly specialised for night vision. The lenses of Menneus have F-numbers of 0.72 compared to 0.58 in Dinopis, the distance between receptors is ca. 4.0 μm compared to 20–22 μm for Dinopis, and image quality is matched to receptor spacing. The lens of Menneus is simple, while that of Dinopis comprises two components of different refractive indices (Blest and Land 1977). Receptive segments of the pm eyes of Dinopis are hexagonal in transverse section and those of adjacent cells are tightly contiguous, allowing the possibility of both optical and electrical coupling (Blest 1978). Receptive segments of Menneus are separated from each other by glial processes containing little pigment, and each segment possesses two rhabdomeres on opposite faces of the cell. Rhabdomere volumes undergo a daily cycle similar to that described for Dinopis, but of relatively minor extent. It is shown that the pm eye of Dinopis could have evolved from that of Menneus by a simple series of transformations, and that a gain of two logarithmic units of sensitivity can be attributed to changes in optical design alone.
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  • 66
    ISSN: 1432-0878
    Keywords: Sturgeon ; Muscle fibres ; Ultrastructure ; Morphometry ; Vascularisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure and vascular supply of the different fibre types in the lateral muscles of the sturgeon Acipenser stellatus were studied by light- and electron microscopy and morphometry. Three fibre types form separate layers without intermingling. The red fibres are superficial, the white fibres deep and the intermediate fibres between them. From morphometric analyses, the mitochondrial volume fraction in red fibres is 30%, in intermediate fibres 3.7% and in white fibres 0.7%. Z lines are most fuzzy in the red fibres. Triads of the sarcotubular system are always situated at the level of the Z discs. In red fibres the three elements are arranged in a series along the myofibrils, whereas in white fibres they are arranged transversely and in the intermediate fibres they are aligned obliquely. The number of capillaries surrounding each fibre is 2.3, 0.9 and 0.2 for the red, intermediate and white fibres, respectively. In red fibres 16% of the surface is directly covered by capillaries. The corresponding percentages for intermediate and white fibres are 5 and 1, respectively. Per unit volume of the fibre, the directly vascularised fibre surface in red fibres is about ten times larger than that of white fibres. The degree of vascularisation of the fibre types is directly related to the volume fraction of mitochondria, and thus to their aerobic capacities.
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  • 67
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    Keywords: Transmitter-dualism ; Multipotential neuron ; Heart innervation ; Ultrastructure ; SEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The segmental heart nerves of Caligo beltrao Illiger (Brassolidae) were examined by transmission and scanning electron microscopy. Heart and alary muscles are innervated by branching processes of single multinucleate neurons (MNNs). There is one MNN situated at each segmental fan-shaped group of alary muscles. The main nerve of the MNN consists of a bundle of processes. This nerve extends centripetally toward the CNS and corresponds to the dorsal portion of the transverse nerve. However, neither axo-somatic nor axo-axonic synapses were found, the presence of which might suggest that this nerve contains axons of different neuronal origin. The synaptic contacts of the MNN with axons originating from the CNS are therefore assumed to be established beyond the spiracular region. In addition to the neuro-muscular junctions of the smaller centrifugal axon branches there are neurohaemal release sites along the entire length of all MNN axon bundles. Axon terminals are packed with either dense-cored or multigranular vesicles. Both morphological types of vesicles are, however, found side by side in the large axons and in the perikaryon, often at the same Golgi element. These morphological findings may support the concept that more than one transmitter is produced in a single neuron. Questions that arise in reference to dual or polyfunctional neurons and to the control of cardiac activity are discussed.
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  • 68
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    Cell & tissue research 205 (1980), S. 67-76 
    ISSN: 1432-0878
    Keywords: Starfish egg ; Cortical reaction ; Vitelline coat ; Fertilization envelope ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The egg coats of a starfish (Patiria miniata) are examined before, during, and after the cortical reaction by scanning and transmission electron microscopy. The unfertilized egg is closely invested by a vitelline coat about 300 μm thick, and cortical granules are scattered in the peripheral cytoplasm. After insemination, as the cortical granules undergo exocytosis, the cortical reaction sweeps over the egg surface. Much of the material ejected from the cortical granules adheres to the inner surface of the vitelline coat as a dense layer about 40 μm thick and as scattered spheres and hemispheres, each about 1 μm in diameter. Together, the vitelline coat and the adherent cortical granule material form the fertilization envelope, which becomes separated from the plasma membrane of the egg by a perivitelline space. The perivitelline space contains some flocculent material, which is too diffuse and discontinuous to be considered a hyaline layer. Possible functions of the starfish egg coats are discussed.
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  • 69
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    Cell & tissue research 205 (1980), S. 273-287 
    ISSN: 1432-0878
    Keywords: Human neurohypophysis ; Ultrastructure ; Pituicytes ; Ependyma ; Choristoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars nervosa of the neurohypophysis from 12 patients undergoing hypophysectomy for palliative treatment of advanced carcinoma was studied electron microscopically. Special attention was given to the cellular elements, the pituicytes. Five different classes of pituicytes, with various transitional forms, were elucidated based on their ultrastructural characteristics: (1) The most common type, referred to as “major pituicytes”, is reminiscent of astrocytes. (2) “Dark pituicytes” are thought to represent different functional stages of the “major pituicytes”. (3) “Ependymal pituicytes” are believed to provide ultrastructural evidence that human pituicytes are phylogenetically derived from ependymal cells. (4) “Oncocytic pituicytes” were observed in all cases and are of unknown significance. (5) The ultrastructural features of “granular pituicytes” suggest the existence of an active uptake and catabolism of extracellular material by pituicytes, probably through “ultraphagocytosis” or “endocytosis”. These five classes of pituicytes are considered to represent different functional forms of one cell line that originates phylogenetically from the ependyma.
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  • 70
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    Cell & tissue research 205 (1980), S. 361-370 
    ISSN: 1432-0878
    Keywords: Enamel organ ; Human foetus ; Tooth germ ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of external enamel epithelium, stellate reticulum and stratum intermedium in primary tooth germs (bell stage) from four human foetuses was investigated. Characteristically, the cells of the differentiated external enamel epithelium, stellate reticulum and stratum intermedium exhibit many free ribosomes, few rough endoplasmic reticulum cisterns, well-developed Golgi complexes, many coated and smooth vesicles, often in relation to the cell membranes, and many bundles of tonofilaments. The cells are connected by numerous desmosomes and gap junctions. A parallel differentiation of stratum intermedium — external enamel epithelium, and the ameloblast layer is demonstrated. The morphology of the cells of the three layers indicates that these have secretory, transport and supporting functions.
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  • 71
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    Cell & tissue research 205 (1980), S. 371-382 
    ISSN: 1432-0878
    Keywords: Ameloblast ; Amelogenesis ; Human foetus ; Tooth germ ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of internal enamel epithelium, preameloblasts and secretory ameloblasts in primary tooth germs (bell stage) from four human foetuses was investigated. The characteristics of the differentiation of internal enamel epithelium via preameloblasts to secretory ameloblasts are described. The internal enamel epithelium consists of a row of low differentiated prismatic cells separated from the dental papilla by a distinct even basal lamina. In the preameloblasts the rough endoplasmic reticulum cisterns and mitochondria increase in number, the Golgi complexes become extensive and take up a distal position, and secretory granules are formed. Furthermore, the basal lamina is removed by coated vesicles, and proximally and distally in the cells a complex of zonulae adhaerentes, terminal webs and gap junctions is formed. The secretory ameloblasts make up a layer of highly differentiated cells demonstrating typical merocrine secretion.
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  • 72
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    Cell & tissue research 205 (1980), S. 493-511 
    ISSN: 1432-0878
    Keywords: Aphids ; Scolopidia ; Sensilla ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron microscopical study of aphid antennal sensilla has revealed two types of trichoid sensilla. Type I, innervated by a single neuron is mechanoreceptive; type II, innervated by three to five neurons is both mechanoreceptive and chemoreceptive with possibly a third function. Johnston's organ in the pedicel comprises a peripheral ring of scolopidia inserted into the joint with the flagellum; two non-peripheral groups of scolopidia lie in the lumen with attachment points in the wall of the third segment. The fine structure of a campaniform sensillum on the pedicel is described together with two homologous and previously unknown sense organs at the joint between the fifth and sixth antennal segments. An unusually placed scolopidium in the lumen of the sixth segment has also been found. The function of this scolopidium is unknown but Johnston's organ, the campaniform sensillum and joint receptors are suggested to act as antennal proprioceptors.
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  • 73
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    Cell & tissue research 206 (1980), S. 291-302 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Perivascular space ; Pericytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The vascular and perivascular regions of the human neurohypophysis were studied electron microscopically. The abluminal basement membrane, perivascular space, luminal basement membrane and endothelium are interposed between the neural parenchyma and the blood stream. The capillaries are fenestrated, with pores measuring 30 to 50 nm in diameter. The perivascular and intercellular spaces form prominent networks that penetrate between rows of neurohypophysial parenchymal cells. The perivascular space contains pericytes, histiocytes, fibroblasts and mast cells, with ultrastructural features typical of each cell type. No transitional forms between histiocytes and pericytes were observed. A schema for the extracellular flow of neurohypophysial hormones through the sinusoidal and perivascular spaces is proposed, suggesting an important role for the pituicytes and their intercellular junctions in the control of hormone release.
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  • 74
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    Cell & tissue research 206 (1980), S. 417-430 
    ISSN: 1432-0878
    Keywords: Pinealocyte ; Fetus ; Mole ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the pinealocytes in the fetal mole (Talpa europaea) was examined and compared with that in the adult mole. The parenchyma of the fetal pineal gland consists primarily of pinealocytes with very few dispersed “glial” cells. Three different morphological types of pinealocytes (I, II and III) were observed. Pinealocytes of types I and II, homologous to the rudimentary photoreceptor cells of lacertilians and birds, were commonly found, especially around the pineal lumen, which is still present in the fetus. These results support the concept of the phylogenetic origin of mammalian pinealocytes from the pineal photoreceptor cells of the non-mammalian vertebrates. Considering their synthetic/secretory activity, the pinealocytes of the mole fetus are characterized by the presence of accumulations of proteinaceous material (APM) in the cisternae of the granular endoplasmic reticulum (GER). Two types of APM were also found. One type shows a paracrystalline organization as described in the adult mole. In the fetus, however, the paracrystalline-organized APM occur only infrequently. A progressive transformation, via an increase in size or fusion of vacuoles containing material originating from the cisternae of the GER in APM, free of a paracrystalline structure, has been observed. Granular vesicles (GV) originating from the Golgi saccules were rarely observed. Sometimes GV and APM were found to be present in the same cell.
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  • 75
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    Cell & tissue research 206 (1980), S. 441-449 
    ISSN: 1432-0878
    Keywords: Protonephridium ; Planarian ; Configuration of flame cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The protonephridial flame cell of the freshwater planarian Bdellocephala brunnea was studied by electron microscopy. This basketlike cell with luminal cilia and fenestrae is known as a cyrtocyte. Careful examination revealed the actual continuity of the fenestrae over the surface of the cell and the microvillous nature of thin cytoplasmic rods composing the fenestrae. On the basis of these findings, a new interpretation was given for the threedimensional configuration of a single cell: this cell is essentially stellate in shape, with several irregular cytoplasmic processes adjoining one another, thus bearing a basic resemblance to the podocyte of a mammalian renal corpuscle. The cytoplasmic features strongly suggest its great capability of reabsorbing substances from the filtrate and of carrying out intracellular digestion. Some additional structural specialization of the fenestra, serving for enlargement of the filtration surface, was observed.
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  • 76
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    Cell & tissue research 206 (1980), S. 451-458 
    ISSN: 1432-0878
    Keywords: Protonephridium ; Planarian ; Regional differentiation of tubules ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A systematic electron microscopic investigation was undertaken to elucidate the regional differentiation of the protonephridial tubules of the freshwater planarian Bdellocephala brunnea. The excretory system consists of many independent protonephridia, each made up of the repeatedly branching “proximal tubules,” and highly tortuous “distal tubule.” The proximal tubules are composed of a simple ciliated epithelium except in the trunk which lacks ciliation. The cytoplasmic features of the ciliated cell closely resemble those of the flame cell, indicating highly active protein reabsorption by pinocytosis. Pinocytosis seems also active in the trunk of the proximal tubules and in the distal tubule, resulting in cytoplasmic vesicles of typical appearance. Salient features of the distal tubule cell are the increased density of the cytoplasmic matrix and the presence of many basal compartments of cytoplasm with mitochondria, a pattern common to many epithelia with osmoregulatory function. The morphology and possible functions of the planarian protonephridium are discussed in comparison with the vertebrate nephron.
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  • 77
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    Cell & tissue research 206 (1980), S. 505-508 
    ISSN: 1432-0878
    Keywords: Ticks ; Ultrastructure ; Synapses ; Muscles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Peripheral nerve axons synapse with somatic muscle fibres in the tropical bont tick Amblyomma variegatum. Each fibre is innervated by numerous terminals; some of the axons synapse more than once. The nerve terminals on coxal muscle fibres contain agranular electron lucent vesicles 50 to 58 nm in size and have the specialised synaptic membranes characteristic of chemically transmitting nerve-muscle junctions. Some of the terminals on trochanteral muscle fibres additionally contain larger vesicles (90 nm) with electron dense cores, suggesting that these junctions operate with a different kind of neurotransmitter.
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  • 78
    ISSN: 1432-0878
    Keywords: Trophamnion ; Coelenterate, Polypodium hydriforme ; Ultrastructure ; Planula ; Parasitism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The larval stage of Polypodium hydriforme is planuliform and parasitic inside the growing oocytes of acipenserid fishes. The larva has inverted germ layers and a special envelope, the trophamnion, surrounding it within the host oocyte. The trophamnion is a giant unicellular provisory structure derived from the second polar body and performing both protective and digestive functions, clearly a result of adaptation to parasitism. The trophamnion displays microvilli on its inner surface, and irregular protrusions anchoring it to the yolk on its outer surface. Its cytoplasm contains long nuclear fragments, ribosomes, mitochondria, microtubules, microfilaments, prominent Golgi bodies, primary lysosomes, and secondary lysosomes with partially digested inclusions. The cells of the larva proper are poorly differentiated. No muscular, glandular, neural, interstitial, or nematocyst-forming cells have been found. The entodermal (outer layer) cells bear flagella and contain rough endoplasmic reticulum; the ectodermal (inner layer) cells lack cilia and contain an apical layer of acid mucopolysaccharid granules. The cells of both layers contain mitochondria, microtubules, and Golgi bodies; their nuclei display large nucleoli with nucleolonema-like structure, decondensed chromatin, and some perichromatin granules. At their apical rims, the ectodermal cells form septate junctions; laterally, the cells of both layers form simple contacts and occasional interdigitations. The lateral surfaces of entodermal cells are strengthened by microtubules.
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  • 79
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    Cell & tissue research 205 (1980), S. 85-94 
    ISSN: 1432-0878
    Keywords: Plasma cells ; Lymphocytes ; Macrophages ; Harderian gland ; Ultrastructure ; Birds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the subepithelial layer of the Harderian gland of some birds, macrophages, lymphocytes, plasma cells, as well as granulocytes are found. These cells are often densely aggregated in the central regions of the lobules, while individual cells occur near the periphery. Pre-plasma cells form desmosome-like contacts with macrophages and junctional complexes with each other. The lymphoid cells are sometimes embedded in a dense homogeneous material, which is also found in the intercellular spaces of the secretory epithelium. The present findings are discussed with reference to immunological aspects.
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  • 80
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    Cell & tissue research 208 (1980), S. 197-206 
    ISSN: 1432-0878
    Keywords: Glycogen ; Degeneration ; Ascidian ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Degeneration is observed in cells of the pyloric gland of Dendrodoa grossularia in which glycogen storage occurs. The ultrastructure of four phases of the degeneration cycle is described. Natural senescence seems to be the cause of the degeneration. Glycogen storage might be the result of metabolic disturbance, but its presence reveals the importance of glycogen in the function of the organ. The role of the pyloric gland is discussed.
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  • 81
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    Cell & tissue research 210 (1980), S. 249-256 
    ISSN: 1432-0878
    Keywords: Synaptic ribbons ; Pineal organ ; Goldfish ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synaptic ribbons in the pineal organ of the goldfish were examined electron microscopically with particular attention to their topography. These structures were formed of parallel membranes, which were poorly preserved with OsO4 fixation and could be extracted from thin sections with pronase indicating their proteinaceous nature. Synaptic ribbons were closely apposed to the plasma membrane bordering dendrites of ganglion cells, but were also related to processes of both photoreceptor and supportive cells. Their close proximity to invaginations of the plasma membrane and portions of the endoplasmic reticulum suggest that they are involved in the turnover of cytoplasmic membranes. Tubular and spherical organelles of unknown function are also described.
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  • 82
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    Cell & tissue research 210 (1980), S. 339-347 
    ISSN: 1432-0878
    Keywords: Seasonal breeding ; Leydig cells ; Ultrastructure ; Bat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Leydig cells of the bat, Myotis adversus, have been examined by electron microscopy throughout fourteen months. During the breeding season the Leydig cells become hypertrophied and are characterised by prominent areas of agranular endoplasmic reticulum and numerous small, membrane-bound granules. Microperoxisomes are also observed. During the period of testicular regression. Leydig cell size and the number of membrane-bound granules are greatly reduced. Lipid droplets and dense bodies are more numerous.
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  • 83
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    Cell & tissue research 210 (1980), S. 359-369 
    ISSN: 1432-0878
    Keywords: Epidermis ; Acidophilic cell ; Histochemistry ; Ultrastructure ; Salmo trutta L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Acidophilic cells occur in the epidermis of several species of salmonid fish, although their abundance fluctuates considerably between individuals within the same population and at different times during the life cycle. The histology, histochemistry and ultrastructure of an acidophilic, granular celltype in the epidermis of the brown trout, Salmo trutta L., is described. At the light microscope level this cell type is easily distinguished from the large, mucus-secreting, epidermal goblet cells by its acidophilic, proteinaceous secretion. At the ultrastructural level this secretion consists of membrane-bound granules formed by the very active Golgi region. It is argued that the acidophilic, granular cell is not a transformed blood cell but constitutes a normal epidermal component of the brown trout. Possible roles of this cell in the function(s) of the epidermis are discussed.
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  • 84
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    Cell & tissue research 210 (1980), S. 155-165 
    ISSN: 1432-0878
    Keywords: Sympathetic ganglion ; Teleost ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to compare the structure of a teleost sympathetic ganglion with those of other vertebrates, light, fluorescence histochemical and electron microscopy were carried out on the coeliac ganglion of the scorpion fish, Myoxocephalus scorpius. In common with studies on other vertebrates, fluorescence histochemistry distinguished two cell types: a) principal neurones which exhibited low levels of specific catecholamine fluorescence and comprise the majority of neurones in the ganglia, and b) smaller intensely fluorescent cells, some of which had processes tens of micrometers long. With the electron microscope, the principal cells were seen to make axodendritic and axosomatic synapses with axons containing mainly 30 nm agranular vesicles at the synaptic site while in other vertebrates usually only one or other synaptic association is present. Both the somata and the processes of intensely fluorescent cells contain 300–600 nm diameter vesicles many of which have electron dense cores. These cells are also innervated by axons containing 30 nm agranular vesicles.
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  • 85
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    Cell & tissue research 210 (1980), S. 417-433 
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Ultrastructure ; Malaysian rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les pinéalocytes d'un Rat de Malaisie (Rattus sabanus), un animal vivant près de l'équateur donc dans une zone où les variations annuelles de la longueur des jours sont minimes, examinés au microscope électronique ont été comparés à ceux d'autres Mammifères. Une seule population de pinéalocytes a été observée. La présence d'un grand nombre de vésicules granulaires et de rubans circonscrits par des vésicules est la caractéristique premi`ere des pinéalocytes de cette espèce. Les rubans circonscrits par des vésicules ont été plus spécialement observés dans les terminaisons des prolongements des pinéalocytes où ils sont nombreux et la plus souvent en contact directe avec l'espace périvasculaire. L'importance physiologique de ces rubans circonscrits par des vésicules et des vésicules granulaires est discuté.
    Notes: Summary The ultrastructure of the pinealocytes of the Malaysian rat (Rattus sabanus), a mammal inhabiting a zone near the equator where the annual variations of daylength are inconspicuous, was examined and compared with that of pinealocytes of other mammals. On the basis of the presence of granular vesicles, only one population of pinealocytes was found. A large number of granular vesicles and vesicle-crowned rodlets is characteristic of the pinealocytes of this equatorial species. Vesicle-crowned rodlets are especially numerous in the endings of the pinealocyte processes and; they most often found in direct topographical connection with the perivascular spaces. The physiological significance of the presence of such large amounts of vesicle-crowned rodlets and of the secretory process characterized by the formation of granular vesicles is discussed.
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    Cell & tissue research 211 (1980), S. 223-234 
    ISSN: 1432-0878
    Keywords: Neurosecretion, insect ; Median neurosecretory cells ; Melanogryllus desertus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Based on the nature of their granules, eight principal types of neurons, six of which are thought to be neurosecretory, are recognized in the median neurosecretory cell group of the brain of Melanogryllus desertus. Most of the neurosecretory cells contain granules with diameters of 200–300 nm. In a few the granules are smaller with diameters varying from 60–100 nm. Most of the cells have well developed Golgi areas and dense bodies of different sizes. Dense bodies are closely associated with neurosecretory granules. Accumulations of electron-dense granular material occur in expanded cisterns of endoplasmic reticulum, particularly in type-I cells.
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  • 87
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    Keywords: Preputial glands ; Nude mice ; Ultrastructure ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The preputial glands of male nude (nu/nu) mice were analyzed by a combination of electron microscopy and gas chromatography to determine whether or not they are affected, like developing hairs and nails, by the nu/nu genotype. Results of the analyses revealed no differences between the glands of nude and normal male mice in either their ultrastructural characteristics or lipid secretory products.
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  • 88
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    Keywords: Rat ; Preovulatory follicle ; Ultrastructure ; Degeneration ; Atresia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To identify and describe ovarian follicles committed to undergo follicular degeneration (atresia), immature rats were primed with pregnant mare serum gonadotropin (PMSG). After PMSG treatment, preovulatory follicles develop but subsequently degenerate. Prior to the appearance of pyknotic nuclei (Stage I of atresia), degenerative changes were observed in focal areas of the granulosa cell layer. These changes include “blebbing” of the cytoplasm and alterations in the shape of the granulosa cells. The appearance of these degenerative changes coincides with a decrease in ovarian concentrations of estradiol and testosterone. Since estrogens and androgens maintain the follicle, the decline in estradiol and testosterone could be responsible for the further degenerative alterations that lead to complete deterioration of the preovulatory follicle. In Stage I atretic follicles, lysosome-derived autophagic vacuoles develop and macrophages invade both the thecal and granulosa cell layers. The combined actions of the autophagic vacuoles and macrophages could destroy both the granulosa-cell and thecal layers and thereby transform the preovulatory follicle into an ovarian cyst.
    Type of Medium: Electronic Resource
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  • 89
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    Cell & tissue research 211 (1980), S. 151-161 
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Pig ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pinealocytes of female pigs were studied electron-microscopically and compared with those of other mammals. A prominent Golgi apparatus forming dense-cored vesicles was widely dispersed in the cytoplasm of the cell body. A very characteristic feature of the pig pinealocytes was the presence of membrane-bounded bodies showing wide variations in internal structure. Possible roles of the dense-cored vesicles and membrane-bounded bodies in secretory processes of pinealocytes are discussed.
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  • 90
    ISSN: 1432-0878
    Keywords: Growth hormone-release-inhibiting factor (somatostatin) ; Sympathetic ganglia ; Ultrastructure ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The superior cervical ganglia (SCG), celiac superior mesenteric ganglia (CMG), and splanchnic nerve of unoperated guinea pigs, as well as both proximal and distal stumps of a previously transected branch of the postganglionic plexus of the CMG, were immunostained for somatostatin (SS). In addition, the PAP technique was adapted for fine-structural visualization of SS. A greater proportion of cells were labeled for SS in the CMG than in the SCG. PAP molecules were present in one type of intraganglionic axons. Only two labeled axons were found in the splanchnic nerve. Neither proximal nor the distal stump of the transected CMG postganglionic nerve contained labeled axons. The present results support the hypothesis that the intraganglionic axons labeled for SS arise from SS-containing intraganglionic neurons.
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  • 91
    ISSN: 1432-0878
    Keywords: Calcergy ; Calcification ; Cutaneous calcinosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In rats a subcutaneous injection of KMnO4 leads to the calcification of the connective tissue. During mineral deposition, both intra- and extracellular changes are observed in the connective tissue. The intracellular phase is characterized by the formation of intramitochondrial granules and cytoplasmic vesicles, both in fibroblastic and extrinsic cells. In the extracellular phase, numerous heterogeneous matrix vesicles appear in the extracellular matrix. At the same time, globular particles which are resistant to microincineration, are observed between the collagen fibrils. The mineralization of the extracellular matrix takes place in two stages. The first stage comprises the appearance of needle-like structures and round aggregates. The needle-like structures are observed occasionally in the matrix vesicles and often in the extracellular matrix where they appear isolated or diverging from a central point. The round aggregates, composed of dense particles, are seen in the ground substance between the collagen fibrils. The second stage is characterized by a progressive mineralization of the collagen fibrils and the elastic fibers, without formation of extended calcified plaques.
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  • 92
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    Cell & tissue research 207 (1980), S. 171-182 
    ISSN: 1432-0878
    Keywords: Nephridia ; Anatomy ; Ultrastructure ; Tardigrada
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The excretory system of Macrobiotus richtersi consists of one dorsal and two lateral components and shows a high degree of structural complexity. In each of these a tricellular external lobe and a column can be distinguished, the two parts being connected distally. The surface of the lobe cells is increased by deep basal infoldings and fingerlike processes which form a labyrinth next to the basal lamina. Their cytoplasm contains numerous mitochondria, a well developed rough endoplasmic reticulum, dictyosomes, and granules in amounts depending on the physiological state of the animal. Excretory crystals occur in caveolae located in the lobe: between the fingershaped processes of the cell and in the space enclosed by the basal lamina on one side and the column on the other. The column faces an extracellular channel meandering along its whole length which is surrounded on the outside by a basal lamina. Morphologically the column is similar to the protonephridial channel of Rotifera. At the ultrastructural level, the cytoplasm of the column shows numerous mitochondria, rough endoplasmic reticulum, lysosomes, and a well developed Golgi apparatus. The lumen of the channel is coated by glycocalyx. At the base of the column several small cells form the proximal part of a duct that communicates with the gut. The morphology and ultrastructure of the excretory system of M. richtersi have been compared with similar a system in Isohypsibius megalonyx (Greven, 1979), and on these grounds a proposal is put forward to call the excretory organs of Tardigrada “nephridia” instead of “Malpighian tubules”.
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  • 93
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    Cell & tissue research 212 (1980), S. 307-314 
    ISSN: 1432-0878
    Keywords: Thymus (Mammalia) ; Erythropoiesis ; Macrocytes ; Anaemia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The thymus of wild young and adult bank voles (Clethrionomys glareolus) was examined by histological methods for the presence of developing erythroid cells. Nucleated erythroid cells were observed in 26% of the glands examined by light microscopy and in 69% of the glands examined by electron microscopy. The largest number of developing erythroid cells was observed in the thymus of pregnant females, also showing raised reticulocyte counts (3.1–10.2%). However, erythropoiesis could also be found in breeding and non-breeding, first year and older animals. Erythroid cells were mainly located in the cortex, sometimes in small groups interspersed between lymphoid cells, and also randomly scattered in the cortex. Occasionally, macrocytic erythroid cells were also present. Pyknotic cells were commonly present, and granulopoiesis was frequently observed.
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  • 94
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    Cell & tissue research 213 (1980), S. 149-157 
    ISSN: 1432-0878
    Keywords: Trophic chamber ; Nutritive cord ; Ultrastructure ; Homoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Each ovariole of the coccidian Aspidiotus hederae contains a single oocyte connected by means of a nutritive cord to the trophic chamber. The trophic chamber consists of three nurse cells characterized by an enlarged, ramified nucleus with a prominent nucleolus. The perinuclear cytoplasm contains nuage material, large amounts of free ribosomes, and scattered mitochondria. Occasional cisternae of the rough endoplasmic reticulum and bacteroids are found in trophocyte cytoplasm. The nutritive cord contains many microtubules in parallel array interspersed with numerous free ribosomes and a few mitochondria. The nutritive cord is strengthened by trophocyte projections which surround it. Microtubules in the projections are oriented perpendicular to the long axis of the cord.
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  • 95
    ISSN: 1432-0878
    Keywords: Anterior pituitary ; Microtubules ; Paracrystalline aggregates ; Ultrastructure ; Chinchilla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Unusual paracrystalline aggregates of microtubules which have not been described in any other mammalian species were observed in cultured anterior pituitary cells of normal chinchillas as well as in situ in the pituitary glands of these animals. These aggregates appeared as regularly arranged tubular structures in the longitudinal plane, and as a checkerboard pattern of closely and regularly packed microtubules when examined in transverse section. Supplementation with vinblastine, colcemide or colchicine in the culture medium did not change these structures morphologically. Each unit of tubules consisted of an outer wall or parellelogram profile and an inner wall composed of a single hexagonal doublet or in a figure “8” form. The outer wall of the parallelogram was 35×28 nm in length for both sides, while the diagonal of the inner wall was 18×28 nm. These paracrystalline aggregates of microtubules in the chinchilla pituitary cells are morphologically distinct from the paracrystalline assembly of cytoplasmic microtubules induced by vinblastine or other alkaloids. The function and significance of these paracrystalline aggregates in anterior pituitary cells of the chinchilla are uncertain.
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  • 96
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    Cell & tissue research 209 (1980), S. 187-200 
    ISSN: 1432-0878
    Keywords: Pineal organ ; Teleostei ; Syngnathidae ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A comparative ultrastructural study was made of the pineal organ of two related species of the Syngnathidae, the pipefish, Syngnathus acus, and the seahorse, Hippocampus hudsonius. Both species have a relatively small pineal organ, which ultrastructurally shows several similarities with the pineal of other teleosts. In the pineal organ of Syngnathus acus, the photoreceptor cells have well-developed outer segments consisting of about 15 to 60 saccules. The pineal supporting cells are characterized by the presence of numerous myeloid bodies. In Hippocampus hudsonius the pineal outer segments are scarce and poorly developed; generally, they show not more than 20 saccules. The apical parts of the supporting cells contain dense-core vesicles with a diameter varying from 100 to 180 nm. Corresponding vesicles were not observed in the pineal organ of Syngnathus acus. Arguments are presented for the suggestion that the pineal organ of the Syngnathidae, in spite of its relatively small size, still has a functional significance. In Syngnathus acus, light reaching the pineal organ directly might have a regulating effect on pineal activity. In Hippocampus hudsonius, however, light acting directly on the pineal organ appears to have minor effect on pineal function.
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  • 97
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    Cell & tissue research 209 (1980), S. 329-343 
    ISSN: 1432-0878
    Keywords: Stomach ; Innervation ; Myenteric plexus ; Guinea-pig ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the vesicle-containing axon profiles in the myenteric ganglia of the guinea-pig stomach was studied in specimens fixed by vascular perfusion and in specimens fixed by immersion in cold fixative after incubation in 5-hydroxydopamine. Three major types of vesicle-containing axon profile were identified in the ganglia: 1. Profiles containing numerous small, mainly spherical vesicles and only limited numbers of large dense-cored vesicles. In perfusion-fixed specimens, the small vesicles in these profiles were all clear. In specimens fixed by immersion after incubation in 5-hydroxydopamine, the profiles could be divided into three types: a) profiles containing small clear vesicles; b) profiles containing small dense-cored vesicles; c) profiles in which the small vesicles contained a peripheral rim of dense material. In these profiles, large vesicles which contained dense cores were rare. The mean diameter of the vesicles in the profiles was also significantly higher than in the profiles containing small clear vesicles. 5. Profiles containing flattened membrane-bounded structures. Reconstructions prepared from serial sections suggested that these structures represented sections through networks of smooth endoplasmic reticulum-like tubules rather than flattened vesicles. 6. Profiles containing many large dense-cored vesicles and few small clear vesicles. In perfusion-fixed specimens, the diameter of the dense-cored vesicles in these profiles was significantly higher than in the type 1 profiles. Type 1 a and type 1 c profiles were much more numerous than either type 2 or type 3 profiles, and type 1 b profiles were few. Synaptic junctions were found in association only with type 1 a profiles. Type 1 a and type 1 b profiles resembled cholinergic and adrenergic axon terminals. The remaining profiles may represent the terminals of different forms of peptidergic axon or of other as yet unidentified types of axon.
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  • 98
    ISSN: 1432-0878
    Keywords: Carbonic anhydrase ; Ultrastructure ; Shell formation ; Ionic regulation ; Lymnaea stagnalis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural localization of carbonic anhydrase (CA) was investigated with the cobalt-bicarbonate method in three epithelia of the pond snail Lymnaea stagnalis. In the epidermis a selective population of “positive cells” was observed. In these cells, CA is confined to the apical and to small parts of the lateral plasma membrane. In cells of the outer mantle epithelium, CA is localized in the lateral and basal parts of the plasma membrane. In cells of the ureter, CA was found apically as well as basally. The localization of CA is discussed in relation to the different functions of the epidermis (electrolyte uptake), mantle (HCO 3 − secretion, calcification) and ureter (electrolyte uptake, acid-base regulation).
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  • 99
    ISSN: 1432-0878
    Keywords: Myocardial cells ; Ultrastructure ; Differentiation ; T-tubule formation ; Opossum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cardiac muscle cells in the right ventricle of the postnatal opposum were studied ultrastructurally, with particular attention to the developmental stage of T-tubule formation. Animals ranging from 5.5cm (day 29 of postnatal life) to 41 cm (young adult) in body length were used. Typical T-tubules were first recognized in a few myocardial cells of the 7.5cm (day 43) opossum. T-tubules increased in number as cardiac muscle cells continued to differentiate until 22cm in body length (about 105 days after birth). At this stage of development most of the T-tubules were completely established. The general mode of differentiation and development of cardiac muscle cells appeared essentially the same as in other mammals.
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  • 100
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    Cell & tissue research 210 (1980), S. 435-445 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Mechanoreceptor ; Skin ; Reptile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The histological and ultrastructural organisation of the epidermal sensory organs in Amphibolurus barbatus has been described with respect to their position and possible functions. The sensory organs, located at the scale's edge, are most numerous in scales of the dorsal surface of the head. Most other scales of the body surface have two receptors located laterally to the spine or keel of the scale. In the imbricate scales of the ventral body region, the receptors lie just beneath the reinforced scale lip. Scanning electron microscopy has revealed the surface of the organ to be a crater lacking any surface projections. These sensory organs have a dermal papilla consisting of a nerve plexus and loose connective tissue. The nerve fibres arising from the plexus, pass to the epidermal columnar cells, where some form nerve terminals at the base of the cells, while others pass between them to form nerve terminals embedded in a superficial layer of cuboidal cells. The superficial terminals are held against the overlying α keratin by masses of tonofilaments. The β keratin is thickened to form a collar around the periphery of the organ but is only about 0.5 μm thick immediately above it. Mechanical deformation of the scale's spine or reinforced scale lip may initiate stimulation of the nerve terminals described.
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