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  • Digitale Medien  (168)
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  • Digitale Medien  (168)
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  • 1
    ISSN: 1432-2307
    Schlagwort(e): Key words Inflammation of the bronchi ; Bronchial biopsy ; Ultrastructure ; Vessels ; Laser therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  An ultrastructural and autoradiographic analysis of changes in 188 biopsy specimens of bronchial mucosa of the large bronchi from 76 patients with chronic inflammatory lung diseses was carried out. Fibrosis results in an apparent reduction of metabolic activity in endothelial cells, affecting the proliferation of basal cells with changes in cell differentiation. Endobronchial laser therapy with an helium-neon laser induces proliferative and metabolic processes in the lamina propria of the bronchial mucosa with hyperaemia, intensive diapedesis of leucocytes and formation of leucocytic infiltrations and granulation tissue. The proliferative and metabolic activity of endothelial and stromal cells increases, and delicate fibrous connective tissue is formed.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Urological research 25 (1997), S. 283-289 
    ISSN: 1434-0879
    Schlagwort(e): Detrusor ; Fixation ; Magnesium Osmolarity ; Smooth muscle cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Magnesium ions added to fixatives for processing to Transmission Electron Microscopy (TEM) have been claimed to cause relaxation of detrusor smooth muscle cells [1]. This should facilitate the morphologic evaluation of the tissue. However, magnesium ions are osmotically active and their addition may cause the fixative to become hypertonic to the tissue. To ascertain whether the presence of magnesium ions causes significant changes compared to those found where the osmolarity is raised without the presence of magnesium, human detrusor specimens were fixed in glutaraldehyde to which increasing amounts of MgCl2 or NaCl were added in different concentrations. With the addition of increasing amounts of MgCl2 and NaCl, the osmolarity of the fixative increased, causing significant changes in the morphology and morphometry of the tissue. The intercellular distances increased, the cells shrank and the shape of the cells changed from smooth and rounded to spiky and angulated. With regard to its muscle-relaxing effect, it was not possible to distinguish the specimens fixed in magnesium-containing fixatives from those without. In this study it was not possible to prove any relaxing effect of magnesium ions added to the fixative. On the contrary the magnesium ions caused an increase in the osmolarity, with significant changes in both the morphometry and the morphology of the human detrusor smooth muscle cells.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0533
    Schlagwort(e): Key words Neuronal intranuclear inclusion ; Amyotrophic lateral sclerosis ; Ammon’s horn ; Ultrastructure ; Ubiquitin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report the presence of round eosinophilic intranuclear inclusions in a patient with sporadic amyotrophic lateral sclerosis (ALS). The inclusions were limited to the hippocampal pyramidal neurons; they were frequently encountered in the CA1 and CA2 regions and much less frequently in the CA3 and CA4 regions and in the subiculum. Ultrastructurally, they consisted of randomly oriented straight filaments, each about 8–14 nm in diameter, some of which had a tubular appearance in cross-section. Electron-dense, granular material was intermingled with the filaments. Immunohistochemically, all the inclusions were positive for ubiquitin, but were negative for several kinds of cytoskeletal protein, including actin, glial fibrillary acidic protein, vimentin, neurofilament polypeptides, keratin, tubulin, tau protein and microtubule-associated protein 2. To our knowledge, this type of neuronal intranuclear inclusion has not so far been reported in ALS, and its distribution limited to the hippocampal formation is of great interest.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 94 (1997), S. 240-246 
    ISSN: 1432-0533
    Schlagwort(e): Keywords Spectrin ; Dystrophin ; Ultrastructure ; Duchenne muscular dystrophy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Spectrin, a major component of the erythrocyte membrane skeleton, has previously been shown to form a two-dimensional lattice in erythrocytes, and in avian or chicken skeletal muscle. Those results were mainly obtained with antibodies against α-spectrin. Using immunofluorescence of semithin cryosections and single muscle fiber preparations, we show here that β-spectrin forms a costameric network which covers the plasma membrane of human skeletal muscle. These spectrin costameres are correlated with the Z-bands. They are longitudinally connected by fine strands and interrupted by myonuclear lacunae. Under mechanical stretching, the costameres retained their correlation to the Z-bands in normal and dystrophin-deficient muscle, up to the point at which the sarcolemma was disrupted. In stretched muscle, in some regions of the stretched fibers in which the costameres seemed to form double strands, the usually 1:1 correlation of spectrin to the Z-bands changed to a 2:1 relation. In dystrophin-deficient muscle, the costameric scaffold of spectrin in the well-preserved fibers appeared normal, indicating that spectrin can be correctly localized in the absence of dystrophin and that the subcellular spectrin organization does not primarily depend on dystrophin expression. The regular organization and the correlation of spectrin costameres to the Z-bands was notable even in stretched Duchenne muscular dystrophy (DMD) muscle. On the other hand, single teased muscle fibers of DMD muscle showed various degrees of morphological alterations of the costameric network, ranging from a focal disarray to complete loss of costameric organization. Because these findings indicate that the costameric spectrin scaffold undergoes secondary changes during the course of the dystrophic process in dystrophin-deficient muscle, spectrin staining of isolated muscle fibers may also serve as a tool to monitor the effect of gene therapy experiments at the single fiber level.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 93 (1997), S. 285-293 
    ISSN: 1432-0533
    Schlagwort(e): Key words Pacinian corpuscles ; Reinnervation after ; axotomy ; Regenerated axon terminals ; Ultrastructure ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The reinnervation pattern of crural pacinian corpuscles was examined by light and electron microscopy in eight adult cats of both sexes 3–18 months after sciatic nerve crush. Normal pacinian corpuscles are each supplied with a single myelinated axon and a single cylindrical axon terminal which may branch in the distal part of the inner core. Reinnervation of these vibroreceptors was very satisfactory after sciatic nerve crush: in a sample of 68 corpuscles examined 3–18 months after the operation, 92.6% were found reinnervated, while only 7.4% remained denervated. At the nerve entry, 84.2% of the reinnervated corpuscles were supplied with a single myelinated axon, while 15.8% received two myelinated axons; some of the axons branched before or after entering the inner core. Near the mid-level of the inner core, 60.3% of 63 reinnervated corpuscles were innervated with a single axon terminal, 22.2% were biterminal, while 17.5% had three or more terminals. Regenerated axon terminals induced the formation of thin lamellar layers in the axial region of the original core and, exceptionally, also at the outer aspect of the original core. In monoterminal corpuscles, the shape and ultrastructure of regenerated endings resembled those of normal controls, whereas in multiterminal corpuscles their shape and profiles were variable. In contrast to previous reports, reinnervated corpuscles did not ultimately become monoterminal. On the contrary, the mean number of 1.3 terminals found in reinnervated crural corpuscles at 3–5 months increased to 1.9 terminals per corpuscle 6–18 months after axotomy.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-0533
    Schlagwort(e): Key words Regeneration ; Diffuse axonal injury ; GAP43 ; Neurofilament ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Traumatic brain injury in animals and humans is well known to cause axonal damage diffusely scattered throughout the brain without evidence of other brain parenchymal change. This observation has prompted some to posit that such damaged axons are well positioned to mount a regenerative attempt. The present study uses an immunocytochemical marker specific for regenerating neurites to explore this issue. Further, in an attempt to expedite and enhance any potential regenerative effort, this study evaluates the efficacy of intrathecally applied nerve growth factor. Three sets of experiments were performed in adult cats. One group of animals was subjected to moderate fluid percussion brain injury and followed for 7 or 14 days post injury, with the continuous intraventricular infusion of nerve growth factor delivered by implanted osmotic pumps. These animals were compared to a second group of time-matched, sham-operated animals receiving artificial cerebrospinal fluid infusion. To assess axonal damage immunohistochemical staining for the low molecular weight neurofilament subunit (NF-L) was carried out using an NR4 monoclonal antibody. To localize axons exhibiting a regenerative response immunohistochemical staining for the growth associated protein GAP43 was employed. In sham controls, at the light microscopic level NF-L-immunoreactive axonal swellings were numerous at 7 days, but by 14 days post injury their frequency declined markedly. In contrast, GAP43-immunoreactive, disconnected reactive axonal swellings were rarely observed at 7 days but were numerous at 14 days. Ultrastructural analysis at 14 days post injury of carefully matched sections revealed reactive axons demonstrating sprouting consistent with a regenerative effort. Analysis of tissue from animals of 14 days of survival indicated that supplementation with nerve growth factor did not appear to enhance the capacity of damaged brain axons to mount a regenerative attempt. Rather, it appears that regenerative efforts seen reflect a spontaneous response. A third group of adult cats, subjected to the same injury but not subjected to osmotic pump implantation, was allowed to survive for 22–28 days. Animals in this group also demonstrated GAP43 immunoreactivity in reactive axonal swellings in the brain stem. This study demonstrates that diffusely injured axons can mount a sustained regenerative attempt that is associated with a reorganization of their cytoskeleton and accompanied by an up-regulation of growth-associated proteins.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 196 (1997), S. 215-226 
    ISSN: 1432-0568
    Schlagwort(e): Key words Natural killer cells ; Ultrastructure ; Parallel tubular arrays ; Perforin ; Granzyme B ; Chondroitin sulfate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Human natural killer (NK) cells contain unique granules with parallel tubular arrays (PTA granules) of approximately 30 nm diameter that can be seen only by electron microscopy. In order to clarify the role of PTA granules in NK cell-mediated cytolysis we examined these structures with regard to frequency and expression of lytic proteins (perforin, granzymes). NK cells (CD3−, CD16+, CD56+) were obtained from heparinized blood of healthy donors and enriched by double-step negative selection using mAb coupled to magnetic beads. PTA granules were found in 31.3% of freshly separated NK cells. When NK cells were cultivated, even in the presence of various stimulating agents (rhIL-2, rhIL-4, rhIL-6, rhIL-12, GM-CSF, rhIFNα, anti-CD16 mAb, dexamethasone), PTA granules disappeared and transformed into conventional primary lysosomes. By immune electron microscopy using antibodies directed against perforin and granzyme B we observed distinct immuno-reactivity in the tubules and in the tubule-associated faintly electron-dense matrix of PTA granules. Immuno-labelling for perforin and granzyme B was also found in the fine granular matrix of primary lysosomes. Finally, we tested the distribution of chondroitin 4-sulfate which is suggested to inactivate lytic proteins. Immuno-reactivity for chondroitin 4-sulfate was detected only in the moderately electron-dense matrix but not in the tubules of PTA granules. These observations indicate that perforin and granzyme B are stored in an inactive form in PTA tubules due to highly ordered paracrystalline protein folding. As soon as the tubules decay the lytic proteins are kept in an environment of chondroitin 4-sulfate for inactivation.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1432-0533
    Schlagwort(e): Key words Meningioma ; Inclusion body ; Vimentin ; Immunocytochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Intracytoplasmic inclusion bodies are rarely found in meningiomas. A 74-year-old woman had an anaplastic meningioma with intracytoplasmic chromophobe inclusion bodies (CIB) histologically. These CIB were various shapes, e.g. round, teardrop-like, fusiform, horseshoe-like, crescentic and perinuclear. The size of CIB ranged from 7 to 14 μm and the nuclei of the tumor cells with CIB were often eccentric. Most CIB were immunopositive only for vimentin, staining more intensely than surrounding cytoplasm in a comparative study using adjacent sections stained with hematoxylin-eosin and vimentin. CIB showed loosely textured filamentous structures which were in parallel and entangled arrangements ultrastructurally. The diameter of the filaments was 13–14 nm and they were thicker than normal intermediate filaments. Moreover, these filaments appeared to be studded with granular and fuzzy substances. These findings suggest that CIB are mainly composed of abnormally synthesized and arranged vimentin filaments.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 93 (1997), S. 579-584 
    ISSN: 1432-0533
    Schlagwort(e): Key words Hypobaric hypoxia ; Cerebral ; microvasculature ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Prolonged hypoxia results in structural and functional adaptive responses to improve tissue oxygen delivery. Structural changes within the brain include vascular proliferation and elongation. The aim of the current study was to investigate whether ultrastructural changes in capillary walls also occur as part of the adaptive response. Adult rats were exposed to 2 or 3 weeks of moderate hypobaric hypoxia at 0.5 atmospheres and their cerebral microvasculature examined using quantitative ultrastructural methods. We found that hypoxic rats had an 18% increase in their brain capillary diameter but no change in endothelial wall thickness, basement membrane thickness, or coverage of the endothelial wall by pericytes. The increased diameter of cerebral capillaries may play an important role in decreasing the resistance to capillary perfusion which is brought about by the increased erythrocyte fraction in the blood of hypoxic rats. Ultrastructural features relevant to the blood-brain barrier were maintained in hypoxic rats. Pericytes, that are thought to form a second line of defense in the blood-brain barrier, maintained their numerical and size relationships to the endothelial cells. Endothelial junctions were unchanged and endothelial vesicles were somewhat lower in density than normal at 2 weeks of hypoxia, but had regained their normal density by 3 weeks. Mitochondria of the brain capillary endothelial cells maintained normal numerical and volume densities in hypoxia, but the mitochondria of the surrounding neuropil were decreased significantly by about 30%.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 94 (1997), S. 425-435 
    ISSN: 1432-0533
    Schlagwort(e): Key words Cell culture ; Central neurocytoma ; Histogenesis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To clarify the histogenesis and differentiation potential of central neurocytoma, a pathological investigation of seven tumors from three patients was conducted using immunohistochemistry and ultrastructural analysis in addition to systematic in vitro studies. Six tumors were studied immunohistochemically and five were examined ultrastructurally. All cases that were immunostained were positive for synaptophysin in nuclear-free neuropil islands. In five tumors, a few tumor cells, in addition to reactive astrocytes, were positive for glial fibrillary acidic protein (GFAP). Vimentin staining was also positive in a few tumor cells of five specimens. Neurofilament staining was always negative. All cases for which ultrastructure was examined showed various synaptic abnormalities. Cultured cells were subdivided into three distinct tumor cell types: neuronal cells which stained for neurofilament proteins with neurosecretory granules; small flat undifferentiated cells with a high nuclear-cytoplasmic ratio and scant cytoplasmic organelles; and small round or multipolar astrocytic cells with 10-nm intermediate filaments which stained for GFAP. Our tissue culture studies disclosed that cultured neurocytoma cells form a cellular mosaic similar to subependymal plate layers that are composed of mitotically active cells, neurons and glia.
    Materialart: Digitale Medien
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  • 11
    ISSN: 1432-0533
    Schlagwort(e): Key words Mucopolysaccharidosis IIID ; Skin ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Mucopolysaccharidosis IIID (MPS-IIID) is the rarest of the MPS-III syndromes. It is caused by deficient activity of lysosomal N-acetylglucosamine-6-sulfatase (G6S). To date, the clinical and biochemical features of seven patients with MPS-IIID have been reported, but no biopsy or autopsy findings have been described. The purpose of this report is to define the ultrastructure of affected cells seen in a skin biopsy from a 14-year-old boy. The child presented with progressive mental deterioration, hyperactivity and mild to moderate dysmorphism. The diagnosis of a mucopolysaccharidosis was suggested, but the initial urine analyses were negative for elevated mucopolysaccharides, and only the third analysis showed abnormal excretion of heparan sulfate. Because of the diagnostic difficulties posed by this case, a skin biopsy was performed for morphological and biochemical studies. Numerous vacuoles were noted in Schwann cells, fibroblasts, smooth muscle cells, eccrine gland and ductal epithelium in resin-embedded sections stained with toluidine blue. Ultrastructurally, many lysosomes were distended with abundant, fibrillar material. Occasionally, lamellated membranous structures were present within the same lysosomes. These findings are consistent with those seen in other forms of MPS, in which the lysosomal storage occurs predominantly, but not exclusively, in mesenchymal cells. Furthermore, deficient activity of G6S was confirmed in cultured skin fibroblasts. This study demonstrates that electron microscopy of skin biopsies is a useful method for identification of patients with clinical features of MPS-IIID whether or not heparan sulfaturia is present.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 94 (1997), S. 499-503 
    ISSN: 1432-0533
    Schlagwort(e): Key words Meningioma ; Immunohistochemistry ; Glial fibrillary acidic protein ; Ultrastructure ; Intercellular lumina
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We studied a recurrent meningioma located in the right frontal lobe. The tumor showed high cellularity and the cells had plump, hyalinous cytoplasm. Immunohistochemically, almost all the tumor cells were positive for epithelial membrane antigen and vimentin, and unexpectedly, glial fibrillary acidic protein (GFAP). Ultrastructural investigation revealed abundant 8- to 10-nm filaments in the cytoplasm. Conspicuous interdigitations with numerous desmosomes were present. Frequently, intracellular and intercellular lumina lined by microvilli were also found. We considered the present case to be an unusual variant of meningioma with GFAP expression. A few cases of meningioma with triple expression of GFAP, vimentin and cytokeratin have been reported previously. However, the present case showed obvious pathological differences from these, and had no immunoreactivity for cytokeratin.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 94 (1997), S. 109-115 
    ISSN: 1432-0533
    Schlagwort(e): Key words Locus coeruleus ; Ultrastructure ; Dihydroetorphine ; Morphine ; Opioids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The locus coeruleus (LC) is a major noradrenergic nucleus in the brain. The activity of the LC neurons is chronically regulated by opioids. So far, very little is known about the morphological changes induced by chronic treatment with opioids. In the present study, the effects of chronic treatment with morphine and dihydroetorphine, a new narcotic analgesic with lower physical dependence potential than morphine, were investigated on the ultrastructure of the rat LC. Rats received saline or increasing doses of morphine or dihydroetorphine for 5 days by twice daily subcutaneous injections. Withdrawal was precipitated in half of the opioid-treated rats by a single intraperitoneal injection of naloxone 4 h after the last injections of opioids. The ultrastructure of the LC was examined by electron microscopy. Results showed that chronic morphine treatment induced a marked injury to the LC neurons. The primary changes in the cell body were the indentation of nuclei, the fragmentation and degranulation of rough endoplasmic reticulum, as well as the disaggregation of polyribosomes. Myelinoid bodies were seen in the processes. An accumulation of presynaptic vesicles was observed in some of the terminals which formed synaptic junctions with the LC neurons as compared to the normal controls. Naloxone-precipitated withdrawal from morphine did not stop the morphine-induced injury on the LC neurons except that less accumulation of presynaptic vesicles occurred. Chronic dihydroetorphine treatment only induced a slight change in the ultrastructure of the LC neurons. These results indicate that the LC neurons are more vulnerable to chronic treatment with morphine than to that with dihydroetorphine.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 94 (1997), S. 338-344 
    ISSN: 1432-0533
    Schlagwort(e): Key words Amyotrophic lateral sclerosis ; Pericapillary rosette ; Immunocytochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This report concerns a comparative immunocytochemical and ultrastructural investigation on pericapillary rosettes (PR) in the lumbar spinal cords of 21 patients with amyotrophic lateral sclerosis (ALS) and 18 age-matched neurologically normal individuals. The purpose of the study was to determine the alteration of PR in relation to the neuronal loss in ALS. The PR were almost always positively immunostained for phosphorylated neurofilament, and some PR immunoreacted with antibodies to synaptophysin and β-amyloid precursor protein. This finding suggests that axonal transport, whether fast or slow, is impaired in the terminal portion of the axon that reaches the capillaries. Some PR were also positively immunostained by the antibody against ubiquitin, anti-calbindin-D 28 K antibody, anti-parvalbumin antibody and the antibody to superoxide dismutase 1. Morphometrically, the number of PR in the anterior horns and lateral column was markedly diminished in ALS compared with controls. At the ultrastructural level, the PR consisted mostly of unmyelinated degenerated axons, and were frequently found outside the basal laminae of the endothelial cell and of the astrocytic foot processes on the opposite side of the capillary, and less often in the space between the two basal laminae. The data indicate that the fate of PR is intimately associated with the neuronal loss of the anterior horn cells and with degenerative change of nerve fibers extending from their mother neurons to the capillaries.
    Materialart: Digitale Medien
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  • 15
    ISSN: 1432-0568
    Schlagwort(e): Key words Mineralization ; Dentine ; Ultrastructure ; Elementanalysis ; Collagen fibrils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The purpose of this study was to compare the biomineralization of circumpulpal dentine with that of mantle dentine by ultrastructural and element-analytical techniques. Forty upper second molar germs of 10-day-old albino rats were cryofixed in liquid nitrogen-cooled propane and embedded in resin after freeze drying. Semithin dry sections were cut for analyzing the calcium and phosphorus concentration in initial mantle dentine, at the mineralization front of circumpulpal dentine, in the middle region of circumpulpal dentine and in mantle dentine peripheral to circumpulpal dentine. For the morphological evaluation of mineral deposits we compared ultrathin and unstained sections of cryofixed molars with chemically fixed molars. For both dentine types it was found that they develop via identical steps of mineral formation at collagen fibrils and non-collagenous matrix molecules. In circumpulpal dentine no globular mineral protrusions along the mineralization front (i.e. calcospherites) and no indications of interglobular dentine at the transition from circumpulpal dentine to mantle dentine were present. The von Korff fibres were not only visible in mantle dentine but also in circumpulpal dentine. Matrix vesicles were present only during the formation of an initial coherent layer of mantle dentine and could not be observed during successive formation of mantle dentine and circumpulpal dentine. The element-analytical data did not demonstrate any difference in the mineral content between the two dentine types. Therefore, we conclude that mantle dentine and circumpulpal dentine in the rat molar possess a high degree of structural and chemical similarity and that only the extent of terminal branching of the odontoblast processes gives an approximate estimation of the thickness of mantle dentine.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 196 (1997), S. 323-333 
    ISSN: 1432-0568
    Schlagwort(e): Key words Herbst mechanoreceptors ; Sensory axons ; White Leghorns ; Japanese quail ; Ultrastructure ; Quantitative study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Herbst corpuscles were studied in the crural region of perinatal and adult chicken and quail in order to find out their number and dimensions and to learn more about their structure, especially in relation to size. Crural corpuscles are arrayed in an encapsulated string between tibia and fibula. They are closely packed together; a small number of corpuscles is found apart from the string, often attached to the periost. The strings of corpuscles are approximately 40 mm long in adult chicken and 20 mm long in the quail. The crural region of the chicken contains 382.8 ± 90.9 (mean ± SD) corpuscles, the numbers ranging from 301 to 582; in the quail, the mean number is 119.2 ± 27.9, with a range from 83 to 167 corpuscles. In the chicken, one axon supplies an average of 1.60 corpuscles; in the quail, the relation of axons to corpuscles is approximately 0.92. In both species, final numbers of crural corpuscles are already attained before hatching and no difference is found in the mean number and range of corpuscles between perinatal and adult birds. In both chicken and quail, individual strings contain corpuscles of various sizes, from large to very small. The chicken corpuscles are generally twice as large in diameter and often longer than those of the quail. The corpuscles are composed of an axon terminal that projects two rows of axonal spines into the clefts of the inner core and ends with an ultraterminal bulb; the terminal is surrounded with a bilaterally symmetrical inner core, amorphous inner space containing collagen fibrils of various thickness, and a capsule. Large chicken corpuscles contain inner cores composed of up to 100 lamellae, while quail inner cores have half that number at the most. The capsules are usually composed of 8 to 10 lamellar layers in both species, but they are thicker in the chicken than in the quail. The possible functional significance of individual structural components of Herbst corpuscles is discussed.
    Materialart: Digitale Medien
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  • 17
    ISSN: 1432-069X
    Schlagwort(e): Key words Diagnosis ; Mechanobullous disease ; Skin ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Electron microscopy combined with morphometry was used to establish values for 24 parameters in normal skin. These results were compared with those similarly obtained from samples of epidermolysis bullosa with a view to facilitating classification of the disease. Six of the eight subtypes of epidermolysis bullosa investigated could be differentiated. Four subtypes showed values for structural components in intact skin which were outside the normal range: (1) epidermolysis bullosa simplex generalisata gravis (hemidesmosomes); (2) epidermolysis bullosa dystrophica Pasini and (3) Cockayne-Touraine (anchoring fibrils); and (4) epidermolysis bullosa acquisita (anchoring fibrils, hemidesmosomes, and lamina lucida and lamina densa aspects of the dermoepidermal junction). Two subtypes revealed specific features which could be assessed qualitatively: distinctive, circumscribed, clumped tonofilament bodies were present in basal keratinocytes from epidermolysis bullosa herpetiformis Dowling-Meara and thick (30 nm diameter) cross-striated anchoring fibrils were absent in epidermolysis bullosa dystrophica generalisata gravis. Epidermolysis bullosa simplex Köbner and Weber-Cockayne forms could not be distinguished.
    Materialart: Digitale Medien
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 204 (1997), S. 121-128 
    ISSN: 1431-4630
    Schlagwort(e): Key words Surimi ; Sardine ; Starch ; Texture ; Water holding capacity ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract  The effect of waxy corn starch (WCS) on the texture, water-holding capacity and microstructure of sardine (Sardina pilchardus) surimi gels in two different systems was studied. In the type A system, increasing amounts of WCS (2, 4, 6 or 8 g/100 g surimi) were added to surimi while maintaining the gel moisture constant at 78%; in the type B system, WCS was added without correcting the gel moisture. Gels were made using two different heat treatments [heat-induced setting (HS) and direct cooking (DC)]. When starch was replaced by surimi (type A) and a heat treatment was applied that favoured formation of a preliminary actomyosin (AM) network (i.e. HS), gel strength (GS) was lower than in the control and decreased as more starch was added, despite an increase in the amount of water held by the gel. Scanning electron microscopy (SEM) showed that the matrix network was fibrillar with a globular surface. Starch appeared to be totally gelatinized and surrounded by a continuous matrix. When the amount of dry matter in gels was increased (type B), in no case did starch have a reinforcing effect, despite an increasing water-holding capacity; SEM showed a denser continuous matrix surrounding the gelatinized starch. Both types of gel made using the heat treatment that allows simultaneous gelling of surimi and gelatinization of starch (i.e. DC) exhibited much poorer GS than did HS gels, while addition of starch made practically no difference to gel texture. The findings suggest that the effect of starch is related to the type of gel matrix that forms upon addition of ingredients. Although such gels contained more water or dry matter, their texture parameters were lower, possibly because of the type of network formed by sardine surimi. Nonetheless, gels of acceptable quality were successfully made with added starch by incorporating less surimi.
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  • 19
    ISSN: 1432-2145
    Schlagwort(e): Key words Asplenium trichomanes L. subsp. trichomanes ; Ferns ; Spermatozoids ; Flagella ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Asplenium trichomanes L. subsp. trichomanes spermatozoids are spirals of about five turns. Keels link the elements of the microtubular ribbon with the plates of the lamellar layer (LL) which are uninterrupted, parallel and curved with an inner angle of about 150°. Electron-opaque filaments connect the microtubules of the multilayered structure (MLS) and the osmiophilic crest, the LL and the MLS-associated mitochondrion and the latter and the plasmalemma. The nucleus occupies the 2.5–3 posterior turns and has an inner honeycomb-shaped chromatin mass and an outer highly condensed chromatin mass with randomly scattered electron-transparent areas. The basal bodies of the ca. 50 flagella are bounded by a reticulum of granular material which forms a plug inside their proximal region; the proximal region of the flagellum has a 9 + 0 pattern. The axoneme has a 9 + 2 pattern.
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Sexual plant reproduction 10 (1997), S. 368-373 
    ISSN: 1432-2145
    Schlagwort(e): Key words Egg-cell isolation (angiosperm) ; Micromanipulation ; Plumbagozeylanica ; Viable egg ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  A protocol for isolating viable eggs in Plumbago zeylanica by mechanical dissection is reported. The optimum solution for isolation was 0.8 M mannitol + 10 mM MOPS + 10 mM CaCl2, (pH 4.5–5.0) with an osmolality of 860–940 mmol/kg. Eggs retain their viability for at least 24 h. Isolated eggs were true protoplasts without cell walls and could tolerate osmolality of 437 mmol/kg to 965 mmol/kg. Observation of the isolated eggs using transmission electron microscopy indicated that they were well preserved and reflected the ultrastructure of physiologically active cells, displaying features similar to those of in vivo egg cells. Notable differences include the absence of a filiform apparatus and the accumulation of dense particles in the plastids, which was most conspicuous in egg cells that were damaged during isolation.
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  • 21
    ISSN: 1432-0738
    Schlagwort(e): Key words 2 ; 5-di(tert-butyl)-1 ; 4-Hydroquinone ; Ca2+ ATPase inhibitor ; Neurotoxicity ; Ultrastructure ; Motor endplate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Female Wistar rats were treated orally for 5 days with 80 mg/kg body weight of 2,5-di(tert-butyl)-1,4-hydroquinone (DTBHQ), a microsomal Ca2+ ATPase inhibitor. Motor endplates of the lumbrical muscles were examined by light and electron microscopy. There was a decrease in body weight in the treated rats from the first day after administration, and toxic signs appeared after the third day, such as adoption of a prone position, salivation, lacrymation, and an abnormal gait and/or muscle weakness. No remarkable macroscopic or light microscopic changes were noted in the lumbrical muscles as well as other peripheral nerves of hind legs of the treated rats killed 1 day after the last DTBHQ treatment. Ultrastructurally, neurotoxicity characterized by loss of synaptic vesicles and mitochondria in the motor endplates, and by destruction of the motor terminals was detected in the lumbrical muscles of the treated rats. These results strongly indicate that DTBHQ targets the motor endplates in the rat lumbrical muscles and suggest that the resultant damage is responsible for the appearance of neurological signs, such as an abnormal gait and loss of muscle control.
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  • 22
    ISSN: 1432-2307
    Schlagwort(e): Key words HHV-7 ; Viral replication ; Virus morphology ; Ultrastructure ; Herpesviruses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Human herpesvirus 7 (HHV-7) was grown in a CD4+ lymphoblastic cell line (SupT1) and in cord blood mononuclear cells (CBMC). Virus infection was demonstrated by immunohistology with positive control sera, with monoclonal antibodies and by in situ hybridization for viral DNA. Cytopathic effects following HHV-7 infection generally resemble those after HHV-6 infection but are less pronounced. The ultrastructural appearance of HHV-7 and the replicative stages were similar to those described by Kramarsky and Sander for HHV-6. There were some minor discrepancies, including quite an extensive and space-filling tegument, a slightly different structure of the nucleoid, the frequent finding of nucleocapsids without any visible core and apparently scarce or delicate spikes on the envelope. These differences may suggest HHV-7 rather than HHV-6, but this finding needs confirmation. Mature HHV-7 particles measured 170 nm in diameter, with nucleocapsids of 90–95 nm and a tegument of about 30 nm.
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 291 (1997), S. 91-95 
    ISSN: 1432-0878
    Schlagwort(e): Key words ECL cells ; Omeprazole ; Granules/vesicles ; Ultrastructure ; Stomach ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  The ECL cells are histamine- and peptide hormone-producing endocrine cells in the rat oxyntic mucosa. They are rich in secretory vesicles and also contain microvesicles and electron-dense granules. They operate under the control of circulating gastrin. In the present study, we examined the ECL-cell ultrastructure after long term treatment with omeprazole, which is known to induce hypergastrinemia, and after withdrawal of the drug. Rats received omeprazole (400 µmol/kg per day, orally) for 16 days and were killed 1, 5, 20, or 40 days after the last dose of the drug. Oxyntic mucosal specimens were processed for electron microscopy. Electron micrographs of ECL-cell profiles were analyzed planimetrically. The ECL-cell profile area increased promptly in response to omeprazole, the secretory vesicles and granules were reduced in number and volume density, the microvesicles were unchanged in number but reduced in volume density, and vacuoles appeared. Within a week after stopping the omeprazole treatment, the numbers and volume densities of secretory vesicles and microvesicles returned to pre-stimulation values. Also, the vacuoles disappeared promptly. The ECL-cell profile area decreased below the pre-stimulation level within five days after stopping treatment, while, in contrast, the granules increased in number and volume density. Somewhat surprisingly, the cell size and the granule compartment did not return to normal until 40 days after stopping treatment.
    Materialart: Digitale Medien
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  • 24
    ISSN: 1432-0878
    Schlagwort(e): Key words: Exocytosis ; Endocytosis ; Gastrin cells ; Carbamylcholine ; Ultrastructure ; Pyloric antrum ; Guinea pig (Hartley) ; Mouse (ICR) ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. In order to capture the exocytotic figures of gastrin cells in the pyloric antrum of the stomach, we examined antral cells of the mouse, rat, and guinea pig by electron microscopy following stimulation with the cholinergic secretagogue carbamylcholine. Increased numbers of omega profiles indicative of exocytosis were seen in the basal or lateral cell membrane after stimulation with carbamylcholine. The number of exocytotic figures in stimulated gastrin cells was higher in the guinea pig than in the mouse and rat. Coated and non-coated omega profiles and coated pits in the plasma membrane were smaller than the secretory granules. Omega profiles with or without electron-dense contents were seen. Coated and non-coated vesicles were often visible near the plasma membrane of stimulated gastrin cells in all three species, large cytoplasmic vacuoles also being found in the guinea pig. In the mouse pretreated with horseradish peroxidase, reaction deposits were observed in the omega profiles and in microvesicles near the plasma membrane. These results suggest that, after exocytosis, membrane retrieval and endocytosis occur in the gastrin cells.
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 290 (1997), S. 39-42 
    ISSN: 1432-0878
    Schlagwort(e): Key words: Ciliogenesis ; Striated rootlets ; Oviduct ; Ciliated cells ; Ultrastructure ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Striated rootlets in ciliated cells are conical banded structures composed of longitudinally aligned filaments. The formation of striated rootlets during ciliognesis in the human oviduct epithelium was studied by electron microscopy. Primitive rootlets appeared at the proximal side of basal bodies before or at the same time as ciliary budding. After the formation of several striations, the tip of the rootlets extended deeply toward the interior of the cell and became differentiated into two distinct parts, viz., the proximal conical part connected to the basal body and the distal fibrillar part. The periodicity of the striations in the fibrillar part was 68.5±2.95 nm, about 5 nm longer than that of the conical part (63.9±2.25 nm). The dark band in the striation was thicker in the fibrillar part than in the conical part. Since the fibrillar part was not observed in the mature cilium, this part was considered as being either degraded or changed into the conical part during ciliogenesis.
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 290 (1997), S. 623-631 
    ISSN: 1432-0878
    Schlagwort(e): Key words: PECAM-1 (platelet/endothelial cell adhesion molecule-1) ; Endothelium ; HUVEC (human umbilical vein endothelial cells) ; Myocardium ; Ultrastructure ; Human ; Rabbit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The subcellular localization of PECAM-1 in endothelial cells was examined by using advanced morphological techniques, such as confocal scanning microscopy and immunolabeling procedures for electron microscopy. The localization of PECAM-1 was studied immunohistochemically with five specific monoclonal antibodies and one polyclonal antibody (all anti-human) in human and rabbit myocardium and in isolated endothelial cells. In vivo, PECAM-1 was localized uniformly on the plasma membrane of all vascular endothelial cells, predominantly on the luminal side of vessels. No specific increase in labeling was found at sites of cell-to-cell contact. In vitro, primary isolated cells (human umbilical vein endothelial cells) showed continuous labeling of the entire cell membrane. Cells of higher passages were labeled in a manner similar to freshly isolated cells. Our findings refute the commonly accepted hypothesis that PECAM-1 is localized only at cell-to-cell contacts. Further, we have not been able to confirm the hypothesis regarding the important mechanical role of PECAM-1 in stabilizing the endothelial monolayer. Since PECAM-1 is also expressed on platelets and is known to bind to itself, the way in which PECAM-1-positive endothelial cells are protected against binding of PECAM-1-positive platelets remains unclear. In view of these findings, the role of PECAM-1 in the leukocyte migration cascade needs to be re-evaluated.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 290 (1997), S. 655-664 
    ISSN: 1432-0878
    Schlagwort(e): Key words: Peroxisomes ; Ultrastructure ; Digestive gland ; Acanthochiton crinita ; Lepidochitona cinerea (Mollusca ; Polyplacophora)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract . This paper presents the first description of peroxisomes in polyplacophorans. As in other molluscs, the hepatopancreas of chitons is composed of basophilic and digestive cells. In the basophilic cells, the endoplasmic reticulum is abundant and several Golgi stacks can be observed. These cells also possess secretion granules and vacuoles with spherites. The digestive cells are mainly characterized by the presence of many food vacuoles. Several peroxisomes were observed in the basophilic cells of Acanthochiton crinita, most of them almost spherical. The matrix is filled with tubular structures and a crystalline nucleoid is also present in these organelles. In the digestive cells of A. crinita, peroxisomes are also almost spherical and possess two kinds of nucleoids. One of them presents a diamond shape and a bundle of tubular structures forms a second kind of nucleoid, which shows an elongated form. In Lepidochitona cinerea, the peroxisomes of basophilic cells are spherical or oval. Within the matrix, a cluster of dense rods and a prismatic nucleoid were observed. In the digestive cells of this species, almost spherical or oval peroxisomes are common, but they are smaller than the peroxisomes of the preceding cells. Nucleoids were not detected, but a few dense rods could be observed in the matrix. In both cell types of the two species, catalase activity was detected in the peroxisomal matrix. In addition, the elongated nucleoid of A. crinita digestive-cell peroxisomes and the nucleoid of L. cinerea basophilic-cell peroxisomes also present catalase activity.
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 290 (1997), S. 71-78 
    ISSN: 1432-0878
    Schlagwort(e): Key words: Development ; Mucosal surface area ; Ultrastructure ; Villus ; Microvillus ; Morphometric analysis ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The mucosal surface area of the chicken duodenum, jejunum, and ileum was determined during development (from 1-day to 12-week-old animals). The morphometric analysis was performed at three magnification levels. The nominal (serosal) surface area was determined at the macroscopic level, from intestinal length and perimeter. Villus and microvillus amplification factors were estimated at light-microscopic and transmission electron-microscopic levels, respectively. The results show, during the period considered: (1) a similar increase in nominal surface area for the three segments (6.5 to 7.2-fold), (2) a rise followed by a slight decrease in the villus amplification factor in the third week of age in the duodenum, a two-fold increase of this variable in the jejunum and no significant developmental variations in the ileum, (3) an increase in the microvillus amplification factor of 1.5-fold in the duodenum and jejunum and of 1.2-fold in the ileum, although a pronounced decrease in the first week of age was observed in the three segments. In conclusion, total mucosal surface area increased, from 1 day to 12 week, 12- to 13-fold in the duodenum and ileum and 20-fold in the jejunum.
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  • 29
    ISSN: 1432-0878
    Schlagwort(e): Key words: Kidney (proximal tubule) ; Apical tubule ; Endosome ; Ultrastructure ; Endocytosis ; Membrane recycling ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The apical cytoplasm of several absorbing epithelia contains well-developed apical tubules (AT) which contribute to membrane recycling from endocytic vacuoles to the apical cell membrane. In this study, we examined three-dimensional structures of the AT in rat kidney proximal tubule cells by transmission and scanning electron microscopy. In thin sections, the AT appeared as straight tubules with a rather constant diameter (70–90 nm), but others were curved and, occasionally, branching. No AT were labeled with the marker for the external cell surface (ruthenium red) or exhibited histochemical enzyme activity for lysosomal hydrolase (acid phosphatase). After intravenous injection of horseradish peroxidase, it was absorbed in the kidney proximal tubule cells and the AT were labeled with HRP reaction products. Stereo-viewing of the labeled AT in thick sections revealed that they formed an interconnected tubular network. Scanning electron microscopy allowed a three-dimensional view of the AT, in which a network of branching and anastomosing tubules was revealed. These observations indicate that the AT are intracellular endosomal compartments which form an extensive tubular network in the apical cytoplasm. The possibility that this apical tubular network serves as a large membrane store for membrane recycling is discussed.
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  • 30
    ISSN: 1615-6102
    Schlagwort(e): Cell differentiation ; Immunolocalisation ; Nitrogenase ; Non-heterocystous cyanobacteria ; Trichodesmium ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Trichodesmium is the first described example of a filamentous cyanobacterium without heterocysts that contains cells specialised for nitrogen fixation. The ultrastructure of cells with and without nitrogenase were compared using primarilyTrichodesmium tenue Wille, but alsoT. thiebautii Gomont andT. erythraeum Ehrenberg et Gomont. Immunohistochemistry demonstrated that the cytoplasm of certain cells was densely labelled with antibodies against Fe-protein (dinitrogenase reductase). Comparative TEM-image analysis revealed that these cells were also distinguished by a denser thylakoid network, dividing the vacuole-like space into smaller units. The nitrogenase-containing cells also exhibited less extensive gas vacuoles as well as fewer and smaller cyanophycin granules compared to cells which lacked nitrogenase. Carboxysomes were present in both cell types in equal proportion. Longitudinal sections showed that cells with nitrogenase were arranged adjacent to each other, and that groups of cells with and without nitrogenase may coexist in the same trichome. The correlation between modifications in ultrastructure and the presence of nitrogenase suggests a new type of cyanobacterial cell specialisation related to nitrogen fixation. The results obtained also question the systematic affiliation of the genusTrichodesmium.
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Protoplasma 200 (1997), S. 31-34 
    ISSN: 1615-6102
    Schlagwort(e): Blastocystis hominis ; Central vacuole ; Accumulation ; Basic proteins ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Basic proteins ofBlastocystis hominis were detected by the ammoniacal silver and ethanolic phosphotungstic acid techniques using electron microscopy. The central vacuole showed many silver grains when treated with ammoniacal silver and an increased electron density when treated with phosphotungstic acid. The intensity of positive reactions correlated with the electron density of the central vacuole, because cells having an electron-lucent central vacuole showed no silver grain deposits. Since it is known that the concentration of electron-dense materials in the central vacuole increases during log phase of growth, and then decreases in stationary phase, this organelle must accumulate basic proteins during cell growth.
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  • 32
    ISSN: 1573-5052
    Schlagwort(e): Algae ; Chloroplast ; Micrasterias ; Photosynthesis ; Ultrastructure ; UV-B
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Exposure of postmitotic growing and non-growing cells of the unicellular green alga Micrasterias denticulata to different UV-B cut-off wavelengths together with simulated sunlight in a sun simulator has revealed a marked resistence of the algae against strong irradiation. While down to a cut-off wavelength of 284 nm irradiated during the most sensitive stage of cell development chloroplast ultrastructure remains unaffected, severe changes in arrangement and structure of stroma and grana thylakoids occur only at the lowest cut-off wavelengths of 280 and 275 nm. The structural alterations end up in a more or less complete desintegration of grana and stroma thylakoids with the remaining membraneous structures appearing in negative staining thus indicating drastic changes in membrane composition. Photosynthetic activity determined by chlorophyll fluorescence (ratio of variable to maximal fluorescence) and oxygen evolution responded more sensitively to UV-B irradiation. With decreasing UV cut-off wavelengths and prolonged incubation a decrease of photochemistry of PS II occured reaching its lowest values after 60 min at 275 and 280 nm. Oxygen production was even maintained under strong UV irradiation with a cut-off wavelenght of 275 nm up to 15 min. With prolonged UV-B treatment any activity was lost. HPLC separations of pigments exhibited the appearance of break-down products (mainly derivatives of chl b and chl a) with decreasing cut-off wavelength and increasing exposure time. The xanthophyll cycle pigments seemed to be unaffected at least for an irradiation period of 60 to 90 min at low UV cut-offs. Possible mechanisms of UV stress avoidance or protection are discussed with regard to the varying altitudes of the natural habitats of the algae.
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  • 33
    ISSN: 1573-5117
    Schlagwort(e): Riseriellus occultus ; Heteronemertea ; Proboscis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have examined with transmission electron microscopythe epithelial layer exposed to the rhynchocoel fluidof the proboscis in the heteronemertine Riseriellus occultus. This epithelium is organized asa monociliated, pseudostratified myoepitheliumconsisting of two cell types: apically situatedmonociliated supportive cells and subapical myocyteslacking cilia. The low supportive cells form acontinuous adluminal sheet and reach with numerouscytoplasmic processes into the extracellular matrix;these cells are characterized by numerous, irregularlyshaped, apical folds projecting into the rhynchocoelfluid, delimiting broad extracellular spaces. Theauthors suppose that both apical and basal folds couldaccommodate stretching of the endothelium when theproboscis is everted. The apical folds of thesupportive cells increase the interface of these withthe rhynchocoel fluid; this feature, together with thepresence of pinocytotic vesicles in such cells,suggest that they could be involved in the exchange ofsubstances between the rhynchocoel fluid and theproboscis. The myocytes are scattered singly withinthe monociliated pseudostratified myoepithelium. Theyare situated between the supportive cells and thesubjacent extracellular matrix. Basement membraneseparating both cells types is lacking. Myofibrillarparts protrude basally from the myocyte somata. Themyofibrillar parts lie in direct apposition to theextracellular matrix, and are oriented circular to thelongitudinal axis of the proboscis. We consider themyocytes to be intra-epithelial, myoepithelial cells.
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 196-199 
    ISSN: 1434-4726
    Schlagwort(e): Nasopharyngeal angiofibroma ; Ultrastructure ; Myofibroblast ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Twenty-eight cases of nasopharyngeal angiofibroma were studied immunohistochemically for cytoskeletal phenotyping of stromal cells. Electron microscopy was also used to study the ultrastructure of five of the tumors. All typical stromal cells showed intensive immunostaining for vimentin, but were negative for smooth muscle actin and desmin. Ultrastructurally, most of these cells appeared to be exclusively fibroblasts. However, in some areas stromal cells were seen that morphologically resembled myofibroblasts by their shapes and arrangement, and were characterized by the coexpression of vimentin and smooth muscle actin. Electron microscopy confirmed their myofibroblastic nature. The present study showed that the typical stromal cells in nasopharyngeal angiofibromas were fibroblasts and not myofibroblasts. In these tumors myofibroblasts occurred only focally, in connection with fibrotic areas and exclusively as a vimentin+/actin+ cytoskeletal phenotype. This indicates that myofibroblasts are not primary stromal tumor cells in nasopharyngeal angiofibromas, but occur due to regressive changes.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 73-77 
    ISSN: 1434-4726
    Schlagwort(e): Development ; Stria vascularis ; Spiral ligament ; Ultrastructure ; Rat cochlea
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The ultrastructural morphology of the interface region between the stria vascularis (SV) and spiral ligament (SL) was examined in the neonatal rat cochlea via transmission electron microscopy. At postnatal day (PND) 3, morphology of both basal cells and fibrocytes was simple and immature. Only a small number of fibrocytes was observed in the SL. Intercellular junctions between basal cells and fibrocytes, and between adjacent fibrocytes, were few. At PND 7, the number of fibrocytes increased, and more organelles appeared within their cytoplasm. From PND 11 to 14, nuclei of the basal cells appeared to be more spindle-shaped and contained more heterochromatin. The cytoplasm of the fibrocytes was pale, and a greater number of cytoplasmic vesicles and mitochondria emerged. More intercellular junctions were observed between basal cells and fibrocytes at the interface region and between fibrocytes in the SL. By PND 21, the morphology of basal cells and fibrocytes and their intercellular junctionsappeared to be adult-like. These morphological observations correlate with previous reports on the functional maturation of the developing rat cochlea.
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Medical molecular morphology 30 (1997), S. 31-36 
    ISSN: 1860-1499
    Schlagwort(e): Parotid gland ; Oncocytoma ; Oncocytic carcinoma ; Mitochondria ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract One case of oncocytoma and another of oncocytic carcinoma of the parotid gland are reported with ultrastructural studies. The incidence of oncocytoma varies from 0.1% to 1.4% of all parotid gland tumors, while oncocytic carcinoma is extremely rate. The oncocytoma was composed of polyhedral cells with fine eosinophilic granular cytoplasm and a rounded nucleus. The tumor cell clusters were surrounded by basement membrane. The tumor cells of the oncocytic carcinoma were also characterized by eosinophilic cytoplasm, but cellular atypia and mitotic figures were found. Electron microscopically, the cytoplasm of the oncocytoma was packed with abundant mitochondria. They were oval or elongated in shape with stacked cristae. Although the tumor cells of the oncocytic carcinoma also contained many mitochondria, their number was less than that of the benign case, and stacked cristae were very few. Basement membrane was not seen. The ultrastructural characteristics of oncocytoma and oncocytic carcinoma of the parotid gland are discussed with reference to previous reports.
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  • 37
    ISSN: 1860-1499
    Schlagwort(e): Preconditioning ; Ultrastructure ; Ischemia and reperfusion ; Adenosine receptor ; Nicorandil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effect of preconditioning (PC) on acute ischemic myocardial injury was investigated in an openchest dog model. Preconditioned dogs received four 5-min occlusions of the left anterior descending coronary artery (LAD), each separated by 10 min of reperfusion. Four groups were used to assess the effect: non-PC group (G-1), PC group (G-2), 8-phenyltheophylline-(adenosine receptor blocker) infused PC group (G-3), and nicorandil- (ATP-sensitive K-channel opener) infused PC group (G-4). The LAD was occluded for 60 min, followed by 60 min of reperfusion in all dogs. The rate of ultrastructural myocardial severe injury was 26% in G-1, 0% in G-2, 5% in G-3, and 0% in G-4. Biochemical analayses also indicated higher values of myocardial contractile function in G-2 and G-4 than G-1 and G-3. These data suggest that the adenosine receptor and K channel may play a key role in PC.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Medical molecular morphology 30 (1997), S. 76-80 
    ISSN: 1860-1499
    Schlagwort(e): Ultrastructure ; Retina ; Rat ; Oxalate ; Potassium pyroantimonate ; X-ray analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Intracellular calcium plays an important role in the intracellular signal transduction as one of the second messengers. In this study, we examined the ultrastructural distribution of calcium in rat retina, using the oxalate pyroantimonate technique and X-ray microanalysis. Large amounts of precipitates were observed inside the disc of outer segments of photoreceptor cells (OS) and the synaptic vesicles of the inner (IPL) and outer plexiform layer (OPL). Precipitates also were observed in the ribosome-rich regions in the cytoplasm and the euchromatinic part in the cell nuclei of the ganglion, amacrine, and bipolar and horizontal cells. However, few precipitates were found in the inner segment of the photoreceptor cells and the retinal pigment epithelium (RPE). X-ray microanalysis with an energydispersive X-ray detector revealed that these precipitates had a peak of antimony and calcium. Therefore, it was suggested that these precipitates were Ca[Sb(OH)6]2, the reaction products of the oxalate-pyroantimonate technique. Our findings showed that calcium precipitates are abundant in retinal regions that are related to visual transmission.
    Materialart: Digitale Medien
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  • 39
    ISSN: 1860-1499
    Schlagwort(e): Systemic triglyceride storage disease ; Cardiomyopathy ; Endomyocardial biopsy ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Ultrastructural changes of a biopsied myocardium were observed by transmission electron microscopy in a patient with cardiomyopathy secondary to systemic triglyceride storage disease with Jordans' anomaly. There were many lipid droplets in the cardiocytes, and lipofuscin and mitochondria were increased. The volume fraction of myofibrils in the cardiocytes decreased because of an abundance of lipid droplets and mitochondriosis. Myocardial contractility may have been reduced by myofibrillar scarcity and low energy production resulting from an abnormality in the metabolism of fatty acids in the cardiocytes.
    Materialart: Digitale Medien
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  • 40
    ISSN: 1860-1499
    Schlagwort(e): Oral malignant melanoma ; Ultrastructure ; Radiosensitivity ; Nucleus ; Melanosome
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The response to radiation of the SSM-1 cell line, derived from oral malignant melanoma, was investigated by survival curve and by light and electron microscopic abservation. Survival curve of the cells was investigated by the colony formation assay. X-irradiation with 2, 4, and 8 Gy was performed against the cell line. Morphological changes of the cells at 6, 24, 72, and 120h after irradiation were examined by both light and electron microscopy. The survival curve of the SSM-1 cells showed higher radiosensitivity than that of cutaneous melanoma cell lines. Giant cells and multinucleated cells were found only 120h after 8Gy irradiation. Ultrastructural observation revealed changes in nucleus and melanosomes; melanosomes increased in number at 120h after 8Gy irradiation. Further alterations after irradiation were noticed primarily in the nucleus. Radiosensitivity of the SSM-1 cell line derived from oral malignant melanoma was higher than that of cutaneous melanoma cell lines. The results of this study may support the concept that radiotherapy is effective for oral malignant melanoma.
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Medical molecular morphology 30 (1997), S. 102-109 
    ISSN: 1860-1499
    Schlagwort(e): Ultrastructure ; Rats ; Muscle spindles ; Immobilization ; Recovery
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study is concerned with the morphological recovery process of muscle spindles following a long period of immobilization. The right hindlimbs of rats were fixed with a plaster cast for 4 weeks. Thereafter, four groups of rats were examined by electron microscopy. One group served as the control after the cast was removed. The other three groups were examined after free walking for 4, 8, and 12 weeks, respectively. The muscle spindles (tibialis anterior muscle) of the individual animals were then ultrastructurally analyzed. The morphological alterations (of the outer capsule, intrafusal muscle fibers, and intrafusal nerve components) gradually recovered during free walking and regained almost all normal features in 12 weeks after returning to walking.
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  • 42
    ISSN: 1860-1499
    Schlagwort(e): Parathyroid gland ; Ultrastructure ; Golden hamster ; Ethanol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Several previous studies have indicated that ingestion of ethanol can induce hypocalcemia or osteoporosis. However, few data are available concerning the effects of ethanol on the parathyroid gland. To clarify the mechanism of ethanol-induced hypocalcemia, we studied the ultrastructure to the parathyroid gland in golden hamsters after shortterm treatment with ethanol. Ethanol was administered by gavage via an intragastric tube at 6g/kg of 50% ethanol in distilled water. The mean serum calcium concentration was significantly low at 3 and 5h after administration. The Golgi complexes of the parathyroid chief cells significantly decreased 1 and 3h after administration. The lipid droplets and the large vacuolar bodies significantly increased 5h after administration. These findings suggest that the cellular activity of the parathyroid gland is suppressed after shortterm treatment with ethanol.
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  • 43
    ISSN: 1860-1499
    Schlagwort(e): Nitric oxide synthase (NOS) ; Endotoxin ; Lung ; Ultrastructure ; In situ hybridization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To evaluate the relationship between pulmonary damage and the induction of nitric oxide synthase (NOS) in endotoxin shock, we injected 10mg/kg ofE. coli endotoxin intraperitoneally to Wistar male rats and observed the changes of the lung during the following 8h by electron microscopy, immunoelectron microscopy, and in situ hybridization. Morphological observation revealed infiltration of macrophages, aggregation of neutrophil in stasis in vascular lumens, and intraalveolar hemorrhage accompanied by epithelial damage. Endothelial constitutive NOS (ecNOS) was immunohistochemically localized in the endoplasmic reticulum of the endothelium of pulmonary arteries and in the cytoplasm of bronchial epithelial cells of control rats. After endotoxin administration, inducible NOS (iNOS) was detected in vascular endothelial cells, vascular smooth muscle cells, bronchial epithelial cells, bronchial smooth muscle cells, alveolar epithelial cells, and macrophages. Reverse transcription polymerase cham reaction (RTPCR) confirmed the expression of ecNOS mRNA and iNOS mRNA in the lung in endotoxin-treated rats and controls. In situ hybridization showed that ecNOS mRNA was expressed in vascular endothelial cells of pulmonary arteries in control rats. After endotoxin administration, iNOS mRNA was expressed in vascular endothelial cells. vascular smooth muscle cells, bronchial epithelial cells, alveolar epithelial cells, and macrophages that had infiltrated the alveolar and perivascular regions. After endotoxin administration, morphological changes and NO overproduction were observed, and it is concluded that NO may play an important role in maintaining the homeostasis of the bloodair barrier in pulmonary structures.
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  • 44
    ISSN: 1860-1499
    Schlagwort(e): Uterine cervix ; Small cell carcinoma ; Xenograft ; Immunohistochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Small cell carcinoma of the uterine cervix is a rare type of gynecological tumor that frequently expresses neuroendocrine differentiation. Its histological origin is unclear. We examined the histopathological characteristics of small cell cervical carcinoma in a patient with elevated serum adrenocorticotropin hormone. We then studied the morphological alteration in xenotransplanted tumors (passages 1–9) using immunohistochemistry and electron microscopy. The primary cervical tumor was characterized by a sheetlike arrangement of uniform small cells with hyperchromatic nuclei and a high nucleocytoplasmic ratio. A ribbon-like or trabecular pattern was also observed in a small area of the tumor. Neuron-specific enolase, chromogranin A, and S-100 were positive for the tumor cells, but cytokeratin was negative. Dense-core granules were detected by electron microscopy. In the xenografted tumor, a serial change from squamous cells to round-to-oval cells was observed. Cytokeratin was immunohistochemically stained in the squamous tumor cells but not in the other tumor cells. In contrast, chromogranin A was stained in some of the round-to-oval cells. Basal lamina underlaid the squamous tumor cells, and desmosome-like junctions were apparent. The cytoplasm was filled with well-differentiated organelles including electron-dense tonofilaments. Elliptical tumor cells resembled the primary carcinoma ultrastructurally. These findings suggest that small cell cervical carcinoma with neuroendocrine properties shares the characteristics of squamous cell carcinoma.
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  • 45
    ISSN: 1861-387X
    Schlagwort(e): Gangliosides ; Neuronal differentiation ; Neuroblastoma ; Ganglioneuroblastoma ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Exogenous administration of gangliosides induced neuronal differentiation with prominent neuritogenesis in human neuroblastoma SH-SY5Y cells in vitro. Neuritogenesis was characterized by ruffling of the cell membrane, the development of lamellipodia and filopodia, and the subsequent elongation and branching of the neurites ultrastructurally. Both axons and neurites were identified. Increased numbers of cell organelles in the neurites and cell bodies were noted. Nonsynaptic contacts and gap junctions formed between neurites or between each neurite and cell body. These findings could be implicated in histopathologic changes from neuroblastoma to ganglioneuroblastoma.
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  • 46
    ISSN: 1861-387X
    Schlagwort(e): Primary leptomeningeal meningiomatosis ; Meningioma ; Whorl formation ; Immunohistochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a 10-year-old girl with a primary leptomeningeal tumor. She presented with a 5-week history of increased intracranial pressure, progressive cranial nerve deficits, and spinal compression signs. She had previously had a granulosa cell tumor, a benign estrogen-producing ovarian tumor, which was resected 6 months before the initial neurological symptoms developed. At autopsy, the brain and spinal cord showed diffuse neoplastic involvement of the leptomeninges. The tumor was composed of small cells with a high nucleus/cytoplasm ratio, which were immunoreactive for vimentin but not for epithelial membrane antigen or cytokeratin. In addition, the tumor contained many small cellular whorls with desmosome-like junctional complexes between the cells, suggesting that the tumor was a meningioma, basically of the meningothelial type. The term ‘meningeal meningiomatosis’ has been used synonymously with “primary meningeal sarcomatosis”. The present tumor was considered to be a rare example of “meningeal meningiomatosis” of true meningothelial cell origin.
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 226 (1980), S. 239-250 
    ISSN: 1434-4726
    Schlagwort(e): Enchondrale Schicht ; Labyrinthknochen ; Ultrastruktur ; Vergleichende Anatomie ; Endochondral layer ; Labyrinthine bone ; Ultrastructure ; Comparative anatomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Neurosurgical review 3 (1980), S. 151-158 
    ISSN: 1437-2320
    Schlagwort(e): 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
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Archives of gynecology and obstetrics 230 (1980), S. 123-135 
    ISSN: 1432-0711
    Schlagwort(e): Clip ; Bleier-Clip ; Tube ; Histologie ; Sterilisation ; Ultrastruktur ; Clip ; Bleier clip ; Fallopian tube ; Histology ; Sterilization ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Archives of gynecology and obstetrics 230 (1980), S. 49-75 
    ISSN: 1432-0711
    Schlagwort(e): Ovarian Sertoli-Leydig cell tumors ; Ultrastructure ; Histogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 38 (1980), S. 125-135 
    ISSN: 1432-1106
    Schlagwort(e): Ventromedial thalamic nucleus ; Cerebellar degenerating boutons ; Ultrastructure ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 52
    ISSN: 1432-2307
    Schlagwort(e): Cortisol ; Myocardium ; Ultrastructure ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 53
    ISSN: 1432-2307
    Schlagwort(e): Parathyroid carcinoma ; Tumour progession ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 54
    ISSN: 1432-2307
    Schlagwort(e): Pituitary adenoma ; Prolactin ; Ultrastructure ; Immunohistochemistry ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 387 (1980), S. 279-288 
    ISSN: 1432-2307
    Schlagwort(e): Pituitary ; Ultrastructure ; Hypophysectomy ; Regeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 387 (1980), S. 353-369 
    ISSN: 1432-2307
    Schlagwort(e): Granulosa cell tumors ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 57
    ISSN: 1432-2307
    Schlagwort(e): Eosinophilic granuloma ; Frontal lobe ; Histiocytosis-X ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 1-11 
    ISSN: 1432-2307
    Schlagwort(e): Soft tissue sarcoma ; Myofibroblasts ; Ultrastructure ; Host response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 27-41 
    ISSN: 1432-2307
    Schlagwort(e): Chondrosarcoma ; Clear-cell chondrosarcoma ; Glucosaminoglycans ; Histochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 60
    ISSN: 1432-2307
    Schlagwort(e): Congenital Nephrotic Syndrome of Finnish type ; Histochemical ; Placentomegaly ; Trophoblast basement membrane alteration ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 59-77 
    ISSN: 1432-2307
    Schlagwort(e): Ethanol ; Myocardium ; Ultrastructure ; Morphometry ; Mitochondria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 103-117 
    ISSN: 1432-2307
    Schlagwort(e): Gonadal dysgenesis ; H-Y antigen ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 287-305 
    ISSN: 1432-2307
    Schlagwort(e): Myeloproliferative disease ; Osteomyelofibrosis ; Bone marrow biopsy ; Blast crisis ; Ultrastructure ; Basophilic leukaemia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 385 (1980), S. 283-291 
    ISSN: 1432-2307
    Schlagwort(e): Hodgkin's disease ; Myofibroblasts ; Ultrastructure ; Nodular sclerosis ; Host response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 158 (1980), S. 167-178 
    ISSN: 1432-0568
    Schlagwort(e): Placenta (human) ; Villous stroma ; Intercellular junctions ; Endothelium ; Ultrastructure ; Freeze-fracturing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 49 (1980), S. 43-49 
    ISSN: 1432-0533
    Schlagwort(e): Rat ; Peripheral nerve ; Macrophage ; Ultrastructure ; Histochemistry ; Acid phosphatase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 51 (1980), S. 65-70 
    ISSN: 1432-0533
    Schlagwort(e): Morphometry ; Glial cells ; Portocaval anastomosis ; Ultrastructure ; Corpus striatum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 51 (1980), S. 113-117 
    ISSN: 1432-0533
    Schlagwort(e): Peroxisomes ; Catalase ; d-amino-acid oxidase ; Glial tumors ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 52 (1980), S. 157-159 
    ISSN: 1432-0533
    Schlagwort(e): Neurons ; Thalamus ; Inclusions ; Ultrastructure ; Myotonic dystrophy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 49 (1980), S. 75-78 
    ISSN: 1432-0533
    Schlagwort(e): Lamellar bodies ; Rough endoplasmic reticulum ; Purkinje neurons ; Adenohypophysis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 50 (1980), S. 81-83 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral neuroblastoma ; Desmoplastic variant ; Dense core vesicles ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 51 (1980), S. 99-105 
    ISSN: 1432-0533
    Schlagwort(e): Skeletal muscle ; Senescence ; 65 to 89-year-old people ; Histopathology ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 160 (1980), S. 11-27 
    ISSN: 1432-0568
    Schlagwort(e): Sertoli cells ; Rat ; Fetal and postnatal life ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 160 (1980), S. 275-284 
    ISSN: 1432-0568
    Schlagwort(e): Adenohypophyseal rudiment ; Follicular cells ; Ultrastructure ; Culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 159 (1980), S. 277-288 
    ISSN: 1432-0568
    Schlagwort(e): Megakaryocyte ; Bone marrow ; Steel mice ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 159 (1980), S. 289-305 
    ISSN: 1432-0568
    Schlagwort(e): Placenta (rat) ; Development ; Intercellular junctions ; Ultrastructure ; Freeze-fracturing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 267 (1980), S. 275-282 
    ISSN: 1432-069X
    Schlagwort(e): Allergic contact dermatitis ; Epidermal cell changes ; Ultrastructure ; Allergische Kontaktdermatitis ; epidermale Zellveränderungen ; Ultrastruktur
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 267 (1980), S. 283-290 
    ISSN: 1432-069X
    Schlagwort(e): Allergic contact dermatitis ; Infiltrating cells ; Monocytes ; Lymphocytes ; Ultrastructure ; Allergische Kontaktdermatitis ; Infiltratzellen ; Monocyten ; Lymphocyten ; Ultrastruktur
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 79
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 49 (1980), S. 225-230 
    ISSN: 1432-0533
    Schlagwort(e): Human pituitary adenomas ; Tissue culture ; Cell culture ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 51 (1980), S. 249-250 
    ISSN: 1432-0533
    Schlagwort(e): Neurons ; Mitochondria ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 81
    ISSN: 1432-0533
    Schlagwort(e): Aging ; Hypertension ; Blood-brain barrier ; Ultrastructure ; Blood vessels
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 188 (1980), S. 65-73 
    ISSN: 1432-041X
    Schlagwort(e): Nuclear migration ; Cleavage ; Microtubules ; Ultrastructure ; Gall midge
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 188 (1980), S. 163-177 
    ISSN: 1432-041X
    Schlagwort(e): Yolk sac ; Ultrastructure ; Embryogenesis ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
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  • 84
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 31 (1980), S. 93-108 
    ISSN: 1432-0827
    Schlagwort(e): Calculus ; Ultrastructure ; Apatite ; Transmission ; Scanning
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 30 (1980), S. 27-34 
    ISSN: 1432-0827
    Schlagwort(e): Ultrastructure ; Calcium ; Cartilage ; Vesicles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    European journal of pediatrics 134 (1980), S. 69-74 
    ISSN: 1432-1076
    Schlagwort(e): Achondrogenesis type I ; Ultrastructure ; Chondrocytes ; Cytoplasmic inclusions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 87
    ISSN: 1432-0738
    Schlagwort(e): Ultrastructure ; Morphometry ; Ageing ; Pentachlorophenol ; Liver
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 58 (1980), S. 501-510 
    ISSN: 1432-1440
    Schlagwort(e): 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
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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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  • 89
    ISSN: 1432-072X
    Schlagwort(e): Mating tube ; Microtubule ; Tremella ; Ultrastructure ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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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  • 90
    ISSN: 1432-072X
    Schlagwort(e): Claviceps purpurea ; Ultrastructure ; Development ; Sclerotium ; Oleosomes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 307-324 
    ISSN: 1432-2307
    Schlagwort(e): Polycythemia vera ; Secondary polycythemia ; Histopathology ; Ultrastructure ; Cytogenetics ; Bone marrow biopsy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 389 (1980), S. 325-341 
    ISSN: 1432-2307
    Schlagwort(e): Polycythemia vera ; Myeloid leukemia ; Histopathology ; Ultrastructure ; Cytogenetics ; Survival
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 206 (1980), S. 95-114 
    ISSN: 1432-0878
    Schlagwort(e): Lateral eyes ; Scorpion ; Ultrastructure ; Retina ; Arhabdomeric cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The dioptric apparatus of the lateral eyes of the scorpion, Androctonus austrails, consists of a cuticular lens, but lacks a vitreous body. The retina is formed by (1) retinula cells displaying a contiguous network of rhabdoms; (2) arhabdomeric cells bearing a distal dendrite that contacts retinula cells via numerous projections and ends before the rhabdomere of the retinula cells; (3) pigment cells that ensheath retinula and arhabdomeric cells with the exception of the contact regions; and (4) neurosecretory fibres possibly originating in the supraesophageal ganglion. The ratio of the number of retinula to arhabdomeric cells is determined to be close to 2 ∶ 1 in the three larger anterolateral eyes, in contrast to the median eyes where the ratio is 5 ∶ 1. The construction of the dioptric apparatus as well as the anatomy of the retina imply that in the lateral eyes of Androctonus australis visual acuity is reduced. A certain degree of spatial discrimination, however, may be retained by the presence of a relatively high number of arhabdomeric cells. It is suggested that the lateral eyes of A. australis mainly function as light detectors, e.g., for Zeitgeber stimuli.
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 206 (1980), S. 123-138 
    ISSN: 1432-0878
    Schlagwort(e): Ultrastructure ; Sense organs ; Compound eyes ; Interfacetal mechanoreceptor ; Coleoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structure of the compound eyes of adult Cicindela tranquebarica Herbst was examined by use of light, scanning, and transmission electron microscopy. Each ommatidium of these photopic eyes is eucone and has a “subcorneal layer” situated between the corneal lens and crystalline cone. A distal rhabdomere consisting only of microvilli from retinula cell seven, a more proximal, rectangular, fused rhabdom formed from six retinula cells, and a basal, eighth retinula cell with a spherical rhabdomere comprise the light sensitive portions of the ommatidium. The “subcorneal layer” consists of lamellae of endocuticular microfibrils and, in surface view, shows 11 concave polygons. Proximal extensions of the crystalline thread form inter-retinular fibres containing microtubules between retinula cells 1/2, 3/4, 5/6, and 7/1. The primary pigment cells are devoid of pigment granules, but are rich in rough endoplasmic reticulum. Proximal to each retinula cell nucleus are two basal bodies, one perpendicular to the other. The more proximal basal body extends two fibrillar feet proximally which fuse to form a horizontally-banded ciliary rootlet extending the length of the retinula peripheral to the rhabdom. Each ommatidium is surrounded by 16 secondary pigment cells. Interfacetal mechanoreceptors between some adjacent lenses each have a single bipolar neuron, with a dendritic sheath, tubular body, cilium, outer and inner sheath cells, and an axon surrounded by a neurilemma sheath cell.
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  • 95
    ISSN: 1432-0878
    Schlagwort(e): Somatostatin cells ; Calcitonin cells ; Ontogeny ; Ultrastructure ; Thyroid (rat)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Calcitonin cells are relatively numerous in the thyroid gland of the rat. In contrast, somatostatin cells are very scarce except at the time of birth and a few days thereafter, when they are conspicuously numerous. Somatostatin cells of the thyroid gland, which are ultrastructurally similar to somatostatin cells in gut and pancreas, also contain immunoreactive calcitonin. It is not clear whether somatostatin cells in the rat thyroid gland produce calcitonin or accumulate calcitonin from the environment.
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 211 (1980), S. 73-82 
    ISSN: 1432-0878
    Schlagwort(e): Preputial glands ; Nude mice ; Ultrastructure ; Gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: 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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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 211 (1980), S. 105-115 
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Preovulatory follicle ; Ultrastructure ; Degeneration ; Atresia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: 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.
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 212 (1980), S. 241-255 
    ISSN: 1432-0878
    Schlagwort(e): Glomerulogenesis ; Glomerular capillaries ; Kidney development ; Corrosion casts ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Kidneys of 2 to 10 day-old rats of Wistar and Sprague-Dawley strains were fixed with glutaraldehyde by retrograde vascular perfusion and then prepared for observation in TEM and SEM. In addition methacrylate casts of differentiating glomerular capillaries were examined by SEM. Although the glomerular vascular pattern differs from one glomerulus to another, its differentiation proceeds according to the following general plan. First the glomerular capillary splits longitudinally, finally to form 3 to 5 lobules consisting of a capillary network, sustained centrally by the mesangium. In the present study the differentiation of glomerular capillaries is described in five successive arbitrarily selected stages. At Stage I a capillary loop penetrates between the lower limb and the middle segment of the S-shaped body, the rudimentary nephron. At Stage II the capillary undergoes a first subdivision, establishing the primitive lobulation of the glomerulus. At Stage III the vascular and urinary poles differentiate. At Stage IV the glomerulus assumes the aspect of a spherical body, and the capillaries in each lobule undergo subdivision. In Stage V the glomerular vascular pattern approaches its adult appearance, although the maturation processes continue for an extended period of time. Hence in the 10 day-old rat the best-differentiated glomeruli are half the size of adult glomeruli, and their capillary loops are proportionally less well-developed. The capillaries of adjacent lobules may communicate with each other, but a direct vascular shunt between the afferent and efferent vessels cannot be demonstrated.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 99
    ISSN: 1432-0878
    Schlagwort(e): Stannius bodies ; Secretory cell types ; Teleosts (Fundulus, Carassius) ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The Stannius bodies of killifish and goldfish were ultrastructurally investigated after exposure of the fish to media of different osmolality and calcium content. In both species two structurally different secretory cell types are found. Type-1 cells predominate. They contain an extensive granular endoplasmic reticulum, some large Golgi areas, and secretory granules with a mean diameter of about 0.4 μm. These cells are activated by transfer of freshwater fish to seawater, but not by transfer to low-calcium seawater. Type-2 cells often contain cytoplasmic processes that penetrate between the type-1 cells and are ending on the basal lamina. In this contact area granule release takes place. Type-2 cells contain some strands of granular endoplasmic reticulum, several small Golgi areas, and secretory granules with a mean diameter between 0.15 and 0.20 μm. Type-2 cells are not activated after transfer of fish to seawater. In killifish seawater exposure leads to a reduction of type-2 cells. The differences between the reactions of both cell types to different media point to functional differences between their secretory products. Type-1 cells may produce a hypocalcemic factor. It is concluded that type-2 cells are typical for freshwater fish or euryhaline fish spending part of their life cycle in freshwater. The proper function of these cells is unclear.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 212 (1980), S. 307-314 
    ISSN: 1432-0878
    Schlagwort(e): Thymus (Mammalia) ; Erythropoiesis ; Macrocytes ; Anaemia ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: 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.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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