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  • 2000-2004
  • 1995-1999  (46)
  • 1980-1984  (104)
  • 1997  (46)
  • 1983  (104)
  • Ultrastructure
  • 1
    Electronic Resource
    Electronic Resource
    Dynamics of the ultrastructural changes in blood and lymphatic capillaries of bronchi in inflammation and following endobronchial laser therapy (1997)
    Springer
    Virchows Archiv 431 (1997), S. 283-290 
    Details
    ISSN: 1432-2307
    Keywords: Key words Inflammation of the bronchi ; Bronchial biopsy ; Ultrastructure ; Vessels ; Laser therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050100
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  • 2
    Electronic Resource
    Electronic Resource
    Fixation of human detrusor smooth muscle cells: role of osmolarity and magnesium ions on the ultrastructural morphology (1997)
    Springer
    Urological research 25 (1997), S. 283-289 
    Details
    ISSN: 1434-0879
    Keywords: Detrusor ; Fixation ; Magnesium Osmolarity ; Smooth muscle cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00942099
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  • 3
    Electronic Resource
    Electronic Resource
    Eosinophilic intranuclear inclusions in the hippocampal pyramidal neurons of a patient with amyotrophic lateral sclerosis (1997)
    Springer
    Acta neuropathologica 93 (1997), S. 532-536 
    Details
    ISSN: 1432-0533
    Keywords: Key words Neuronal intranuclear inclusion ; Amyotrophic lateral sclerosis ; Ammon’s horn ; Ultrastructure ; Ubiquitin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050649
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  • 4
    Electronic Resource
    Electronic Resource
    Spatial distribution of β-spectrin in normal and dystrophic human skeletal muscle (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 240-246 
    Details
    ISSN: 1432-0533
    Keywords: Keywords Spectrin ; Dystrophin ; Ultrastructure ; Duchenne muscular dystrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050699
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  • 5
    Electronic Resource
    Electronic Resource
    Reinnervation of cat pacinian corpuscles after nerve crush (1997)
    Springer
    Acta neuropathologica 93 (1997), S. 285-293 
    Details
    ISSN: 1432-0533
    Keywords: Key words Pacinian corpuscles ; Reinnervation after ; axotomy ; Regenerated axon terminals ; Ultrastructure ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050616
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  • 6
    Electronic Resource
    Electronic Resource
    Characterization of a prolonged regenerative attempt by diffusely injured axons following traumatic brain injury in adult cat: a light and electron microscopic immunocytochemical study (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 329-337 
    Details
    ISSN: 1432-0533
    Keywords: Key words Regeneration ; Diffuse axonal injury ; GAP43 ; Neurofilament ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050715
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  • 7
    Electronic Resource
    Electronic Resource
    Morphological and functional analysis of PTA granules in human NK cells (1997)
    Springer
    Anatomy and embryology 196 (1997), S. 215-226 
    Details
    ISSN: 1432-0568
    Keywords: Key words Natural killer cells ; Ultrastructure ; Parallel tubular arrays ; Perforin ; Granzyme B ; Chondroitin sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050092
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  • 8
    Electronic Resource
    Electronic Resource
    Intracytoplasmic chromophobe inclusion bodies in an anaplastic meningioma (1997)
    Springer
    Acta neuropathologica 93 (1997), S. 421-425 
    Details
    ISSN: 1432-0533
    Keywords: Key words Meningioma ; Inclusion body ; Vimentin ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050634
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  • 9
    Electronic Resource
    Electronic Resource
    Ultrastructural concomitants of hypoxia-induced angiogenesis (1997)
    Springer
    Acta neuropathologica 93 (1997), S. 579-584 
    Details
    ISSN: 1432-0533
    Keywords: Key words Hypobaric hypoxia ; Cerebral ; microvasculature ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050654
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  • 10
    Electronic Resource
    Electronic Resource
    Central neurocytoma: an immunohistochemical, ultrastructural and cell culture study (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 425-435 
    Details
    ISSN: 1432-0533
    Keywords: Key words Cell culture ; Central neurocytoma ; Histogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050729
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  • 11
    Electronic Resource
    Electronic Resource
    The ultrastructure of skin from a patient with mucopolysaccharidosis IIID (1997)
    Springer
    Acta neuropathologica 93 (1997), S. 210-213 
    Details
    ISSN: 1432-0533
    Keywords: Key words Mucopolysaccharidosis IIID ; Skin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050605
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  • 12
    Electronic Resource
    Electronic Resource
    An unusual meningioma variant with glial fibrillary acidic protein expression (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 499-503 
    Details
    ISSN: 1432-0533
    Keywords: Key words Meningioma ; Immunohistochemistry ; Glial fibrillary acidic protein ; Ultrastructure ; Intercellular lumina
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050739
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  • 13
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in rat locus coeruleus induced by chronic opioids (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 109-115 
    Details
    ISSN: 1432-0533
    Keywords: Key words Locus coeruleus ; Ultrastructure ; Dihydroetorphine ; Morphine ; Opioids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050681
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  • 14
    Electronic Resource
    Electronic Resource
    Immunocytochemical and ultrastructural study of pericapillary rosettes in amyotrophic lateral sclerosis (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 338-344 
    Details
    ISSN: 1432-0533
    Keywords: Key words Amyotrophic lateral sclerosis ; Pericapillary rosette ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050716
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  • 15
    Electronic Resource
    Electronic Resource
    The mineralization of mantle dentine and of circumpulpal dentine in the rat: an ultrastructural and element-analytical study (1997)
    Springer
    Anatomy and embryology 195 (1997), S. 289-297 
    Details
    ISSN: 1432-0568
    Keywords: Key words Mineralization ; Dentine ; Ultrastructure ; Elementanalysis ; Collagen fibrils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050048
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  • 16
    Electronic Resource
    Electronic Resource
    Crural Herbst corpuscles in chicken and quail: numbers and structure (1997)
    Springer
    Anatomy and embryology 196 (1997), S. 323-333 
    Details
    ISSN: 1432-0568
    Keywords: Key words Herbst mechanoreceptors ; Sensory axons ; White Leghorns ; Japanese quail ; Ultrastructure ; Quantitative study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050101
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  • 17
    Electronic Resource
    Electronic Resource
    Electron microscopy and morphometry enhances differentiation of epidermolysis bullosa subtypes. With normal values for 24 parameters in skin (1997)
    Springer
    Archives of dermatological research 289 (1997), S. 631-639 
    Details
    ISSN: 1432-069X
    Keywords: Key words Diagnosis ; Mechanobullous disease ; Skin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004030050252
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  • 18
    Electronic Resource
    Electronic Resource
    Waxy corn starch affecting texture and ultrastructure of sardine surimi gels (1997)
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 204 (1997), S. 121-128 
    Details
    ISSN: 1431-4630
    Keywords: Key words Surimi ; Sardine ; Starch ; Texture ; Water holding capacity ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002170050048
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  • 19
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the mature spermatozoid of the fern Asplenium trichomanes L. subsp. trichomanes (1997)
    Springer
    Sexual plant reproduction 10 (1997), S. 142-148 
    Details
    ISSN: 1432-2145
    Keywords: Key words Asplenium trichomanes L. subsp. trichomanes ; Ferns ; Spermatozoids ; Flagella ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050081
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  • 20
    Electronic Resource
    Electronic Resource
    Mechanical isolation and ultrastructural characterization of viable egg cells in Plumbago zeylanica (1997)
    Springer
    Sexual plant reproduction 10 (1997), S. 368-373 
    Details
    ISSN: 1432-2145
    Keywords: Key words Egg-cell isolation (angiosperm) ; Micromanipulation ; Plumbagozeylanica ; Viable egg ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050111
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  • 21
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in motor endplates of the lumbrical muscles of rats induced by a microsomal Ca2+ ATPase inhibitor, 2,5-di(tert-butyl)-1,4-hydroquinone (1997)
    Springer
    Archives of toxicology 72 (1997), S. 115-118 
    Details
    ISSN: 1432-0738
    Keywords: Key words 2 ; 5-di(tert-butyl)-1 ; 4-Hydroquinone ; Ca2+ ATPase inhibitor ; Neurotoxicity ; Ultrastructure ; Motor endplate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002040050477
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  • 22
    Electronic Resource
    Electronic Resource
    Ultrastructural study of human herpesvirus-7 replication in tissue culture (1997)
    Springer
    Virchows Archiv 430 (1997), S. 417-426 
    Details
    ISSN: 1432-2307
    Keywords: Key words HHV-7 ; Viral replication ; Virus morphology ; Ultrastructure ; Herpesviruses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050051
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  • 23
    Electronic Resource
    Electronic Resource
    Reversibility of omeprazole-evoked changes in the ultrastructure of ECL cells in the rat stomach (1997)
    Springer
    Cell & tissue research 291 (1997), S. 91-95 
    Details
    ISSN: 1432-0878
    Keywords: Key words ECL cells ; Omeprazole ; Granules/vesicles ; Ultrastructure ; Stomach ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050982
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  • 24
    Electronic Resource
    Electronic Resource
    Exocytosis in the antral gastrin cells of mouse, rat, and guinea pig after stimulation by carbamylcholine (1997)
    Springer
    Cell & tissue research 289 (1997), S. 463-472 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Exocytosis ; Endocytosis ; Gastrin cells ; Carbamylcholine ; Ultrastructure ; Pyloric antrum ; Guinea pig (Hartley) ; Mouse (ICR) ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050892
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  • 25
    Electronic Resource
    Electronic Resource
    Development of striated rootlets during ciliogenesis in the human oviduct epithelium (1997)
    Springer
    Cell & tissue research 290 (1997), S. 39-42 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Ciliogenesis ; Striated rootlets ; Oviduct ; Ciliated cells ; Ultrastructure ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050905
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  • 26
    Electronic Resource
    Electronic Resource
    Platelet/endothelial cell adhesion molecule-1 (PECAM-1) is localized over the entire plasma membrane of endothelial cells (1997)
    Springer
    Cell & tissue research 290 (1997), S. 623-631 
    Details
    ISSN: 1432-0878
    Keywords: Key words: PECAM-1 (platelet/endothelial cell adhesion molecule-1) ; Endothelium ; HUVEC (human umbilical vein endothelial cells) ; Myocardium ; Ultrastructure ; Human ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050968
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  • 27
    Electronic Resource
    Electronic Resource
    The peroxisomes of the hepatopancreas in two species of chitons (1997)
    Springer
    Cell & tissue research 290 (1997), S. 655-664 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Peroxisomes ; Ultrastructure ; Digestive gland ; Acanthochiton crinita ; Lepidochitona cinerea (Mollusca ; Polyplacophora)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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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    URL: http://dx.doi.org/10.1007/s004410050971
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  • 28
    Electronic Resource
    Electronic Resource
    Mucosal surface area in chicken small intestine during development (1997)
    Springer
    Cell & tissue research 290 (1997), S. 71-78 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Development ; Mucosal surface area ; Ultrastructure ; Villus ; Microvillus ; Morphometric analysis ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050909
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  • 29
    Electronic Resource
    Electronic Resource
    Apical tubular network in the rat kidney proximal tubule cells studied by thick-section and scanning electron microscopy (1997)
    Springer
    Cell & tissue research 288 (1997), S. 317-325 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Kidney (proximal tubule) ; Apical tubule ; Endosome ; Ultrastructure ; Endocytosis ; Membrane recycling ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050817
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  • 30
    Electronic Resource
    Electronic Resource
    Ultrastructural characterisation of cells specialised for nitrogen fixation in a non-heterocystous cyanobacterium,Trichodesmium spp. (1997)
    Springer
    Protoplasma 197 (1997), S. 76-85 
    Details
    ISSN: 1615-6102
    Keywords: Cell differentiation ; Immunolocalisation ; Nitrogenase ; Non-heterocystous cyanobacteria ; Trichodesmium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279886
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    Electronic Resource
    Ultrastructural localization of basic proteins ofBlastocystis hominis (1997)
    Springer
    Protoplasma 200 (1997), S. 31-34 
    Details
    ISSN: 1615-6102
    Keywords: Blastocystis hominis ; Central vacuole ; Accumulation ; Basic proteins ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280732
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  • 32
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    Electronic Resource
    Physiological and structural changes in the chloroplast of the green alga Micrasterias denticulata induced by UV-B simulation (1997)
    Springer
    Plant ecology 128 (1997), S. 55-64 
    Details
    ISSN: 1573-5052
    Keywords: Algae ; Chloroplast ; Micrasterias ; Photosynthesis ; Ultrastructure ; UV-B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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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    URL: http://dx.doi.org/10.1023/A:1009754722357
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    Ultrastructural study of the proboscis endothelium of Riseriellus occultus (Nemertea, Heteronemertea) (1997)
    Springer
    Hydrobiologia 365 (1997), S. 121-127 
    Details
    ISSN: 1573-5117
    Keywords: Riseriellus occultus ; Heteronemertea ; Proboscis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003101703985
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    Immunohistochemical and electron microscopical characterization of stromal cells in nasopharyngeal angiofibromas (1997)
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 196-199 
    Details
    ISSN: 1434-4726
    Keywords: Nasopharyngeal angiofibroma ; Ultrastructure ; Myofibroblast ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00879273
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  • 35
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    Electronic Resource
    Structural maturation of the interface region between the stria vascularis and spiral ligament in the neonatal rat cochlea (1997)
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 73-77 
    Details
    ISSN: 1434-4726
    Keywords: Development ; Stria vascularis ; Spiral ligament ; Ultrastructure ; Rat cochlea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01526182
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  • 36
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    An ultrastructural study of oncocytoma and oncocytic carcinoma of the parotid gland (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 31-36 
    Details
    ISSN: 1860-1499
    Keywords: Parotid gland ; Oncocytoma ; Oncocytic carcinoma ; Mitochondria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01458349
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  • 37
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    Electronic Resource
    Ultrastructural and biochemical studies of ischemic preconditioning using an adenosine receptor blocker and an ATP-sensitive K channel opener (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 63-69 
    Details
    ISSN: 1860-1499
    Keywords: Preconditioning ; Ultrastructure ; Ischemia and reperfusion ; Adenosine receptor ; Nicorandil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545083
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  • 38
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    Electronic Resource
    Ultrastructural localization of calcium in rat retina with oxalate pyroantimonate and energy-dispersive X-ray detector (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 76-80 
    Details
    ISSN: 1860-1499
    Keywords: Ultrastructure ; Retina ; Rat ; Oxalate ; Potassium pyroantimonate ; X-ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545085
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  • 39
    Electronic Resource
    Electronic Resource
    Cardiomyopathy secondary to systemic triglyceride storage disease (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 88-91 
    Details
    ISSN: 1860-1499
    Keywords: Systemic triglyceride storage disease ; Cardiomyopathy ; Endomyocardial biopsy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545087
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  • 40
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    Electronic Resource
    An ultrastructural study of the influence of radiation against cell line-derived human oral malignant melanoma (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 81-87 
    Details
    ISSN: 1860-1499
    Keywords: Oral malignant melanoma ; Ultrastructure ; Radiosensitivity ; Nucleus ; Melanosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545086
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  • 41
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    Electronic Resource
    Muscle spindles in immobilized muscle: electron microscopic study of recovery (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 102-109 
    Details
    ISSN: 1860-1499
    Keywords: Ultrastructure ; Rats ; Muscle spindles ; Immobilization ; Recovery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545090
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  • 42
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    Electronic Resource
    Effects of short-term treatment with ethanol on the ultrastructure of the adult golden hamster parathyroid gland (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 148-153 
    Details
    ISSN: 1860-1499
    Keywords: Parathyroid gland ; Ultrastructure ; Golden hamster ; Ethanol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545316
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  • 43
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    Electronic Resource
    Ultrastructural changes and localization of nitri oxide synthase in rat lung induced by endotoxin administration (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 177-184 
    Details
    ISSN: 1860-1499
    Keywords: Nitric oxide synthase (NOS) ; Endotoxin ; Lung ; Ultrastructure ; In situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545768
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  • 44
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    Electronic Resource
    Squamous cell characteristics in small cell carcinoma of the uterine cervix: histological, immunohistochemical, and ultrastructural study in xenografted small cell carcinoma (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 202-208 
    Details
    ISSN: 1860-1499
    Keywords: Uterine cervix ; Small cell carcinoma ; Xenograft ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545771
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  • 45
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    Electronic Resource
    Neuronal differentiation of human neuroblastoma SH-SY5Y cells by gangliosides (1997)
    Springer
    Brain tumor pathology 14 (1997), S. 5-11 
    Details
    ISSN: 1861-387X
    Keywords: Gangliosides ; Neuronal differentiation ; Neuroblastoma ; Ganglioneuroblastoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02478862
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  • 46
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    Electronic Resource
    Primary leptomeningeal meningiomatosis with widespread whorl formation (1997)
    Springer
    Brain tumor pathology 14 (1997), S. 139-143 
    Details
    ISSN: 1861-387X
    Keywords: Primary leptomeningeal meningiomatosis ; Meningioma ; Whorl formation ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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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    URL: http://dx.doi.org/10.1007/BF02478883
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  • 47
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    Electronic Resource
    A sertoli-leydig cell tumor and pregnancy (1983)
    Springer
    Archives of gynecology and obstetrics 233 (1983), S. 295-308 
    Details
    ISSN: 1432-0711
    Keywords: Sertoli-Leydig cell tumor ; Pregnancy ; Catheterization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An extremely rare case of a conception occurring in a 26-year-old patient with a small virilizing Sertoli-Leydig cell tumor (diameter: 0.6 cm), bilateral polycystic ovaries and non-tumorous adrenal hyperandrogenism is presented. Prepregnancy findings included hirsutism, clitoromegaly, secondary amenorrhea, and elevated peripheral plasma testosterone (T; 5.7 ng/ml). Extensive basal steroid screening, dynamic function tests, conventional radiologic procedures, selective glandular vein catheterization, and laparoscopy failed to localize unequivocally the source of androgen excess, but suggested bilateral adrenal involvement. The patient conceived during the diagnostic work-up; peripheral T levels increased to 12.1 ng/ml within the first trimester. An exploratory laparotomy with left adrenalectomy, right adrenal biopsy and left ovarian wedge resection revealed an incompletely removed Sertoli-Leydig cell tumor, but normal adrenal histology. The pregnancy was terminated, a left oophorectomy and right ovarian wedge resection were performed at 14 weeks' gestation. Subsequently, peripheral androgens returned to normal, regular menses resumed, and hirsutism disappeared. Three years later the patient delivered a healthy female infant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02133804
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  • 48
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    Electronic Resource
    Membranous lipodystrophy-like changes in ischemic necrosis of the legs (1983)
    Springer
    Virchows Archiv 399 (1983), S. 191-205 
    Details
    ISSN: 1432-2307
    Keywords: Membranous lipodystrophy ; Fat tissue ; Ischemic necrosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Subcutaneous fat from 3 patients with ischemic necrosis of the legs due to arteriosclerotic obstruction were examined histologically and ultrastructurally. Markedly convoluted membranocystic changes were found in all 3 cases. The light and electron microscopic findings of the membranocystic lesions are very similar to those of fat tissue changes in membranous lipodystrophy. Bone lesions and mental disturbance which suggest membranous lipodystrophy, however, were absent in these cases. It is concluded from these results that the membranocystic changes characteristic of membranous lipodystrophy can be produced by circulatory disturbance and the lesions are one of the non-specific changes of adipose tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00619579
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  • 49
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    Electronic Resource
    Ultrastructure of the congenital epulis (1983)
    Springer
    Virchows Archiv 401 (1983), S. 251-260 
    Details
    ISSN: 1432-2307
    Keywords: Congenital epulis ; Ultrastructure ; Granular cells ; Intracellular collagen fibrils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This report presents the ultrastructural features of a congenital epulis. The granular cells of the epulis were packed with numerous membrane bound cytoplasmic granules containing particles, small vesicles, and electron-dense materials. These granules were negative in immunohistochemical reaction for CEA (DAKO PAP KIT). Cytoplasmic organelles such as mitochondria, rough surfaced endoplasmic reticulum, and Golgi apparatus, were absent. Nuclei were markedly indented. Occasionally, banded intracellular collagen fibrils were observed within the cytoplasm. Some of these fibrils were surrounded by a limiting membrane, whereas others appeared to lie free in the cytoplasm. The collagen fibrils were also seen within a deep invagination of the cell surface. There was no basal lamina around the granular cells. Sporadically, mast cells with many granules containing lamellar formations were found between the granular cells. These observations support the idea that granular cells of the congenital epulis are derived from mesenchymal cells, probably fibroblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00734843
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  • 50
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    Electronic Resource
    Mammosomatotroph cell adenoma of the human pituitary: a morphologic entity (1983)
    Springer
    Virchows Archiv 398 (1983), S. 277-289 
    Details
    ISSN: 1432-2307
    Keywords: Pituitary adenoma ; Ultrastructure ; Immunocytochemistry ; Acromegaly ; Hyperprolactinemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Nine cases of a hitherto undescribed morphologic entity, termed mammosomatotroph cell adenoma of the human pituitary, are reported. These tumors, occurring mostly in men, are invariably associated with acromegaly (or gigantism) and high-normal or slightly elevated blood prolactin levels, and it cannot be distinguished clinically from well-differentiated growth hormone cell or mixed growth hormone cell-prolactin cell adenomas. They show a slow growth rate and usually exhibit a diffuse pattern and intense cytoplasmic acidophilia by histology. The immunoperoxidase technique detects both growth hormone and prolactin within the same cells. Electron microscopy reveals monomorphous tumors with a fine structure markedly similar to that of well-differentiated, densely granulated growth hormone cell adenomas. An added feature and diagnostic marker of mammosomatotroph cell adenoma is the presence of extracellular deposits of secretory material. One tumor shows a marked abnormality of hormone packaging and storage, resulting in the cytoplasmic accumulation of pleomorphic bodies containing semicrystalline secretory material.
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    URL: http://dx.doi.org/10.1007/BF00583585
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  • 51
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    Electronic Resource
    Experimental autoallergic sialadenitis in mice (1983)
    Springer
    Virchows Archiv 400 (1983), S. 143-154 
    Details
    ISSN: 1432-2307
    Keywords: Experimental autoallergic sialadenitis ; Mice ; Submandibular gland ; Histopathology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental autoallergic sialadenitis was induced in SL/Ni mice by one or two injections of syngeneic submandibular gland homogenate emulsified with adjuvant. Light microscopically, there were marked lymphoid cell infiltration in the submandibular glands with high incidence and proliferation of duct epithelia. Furthermore complete alteration of whole glandular lobules in some cases was observed. Ultrastructurally, small and medium sized lymphocytes and plasma cells constituted a major portion of the infiltrating cells, and lymphocytes were frequently observed inside the basal lamina of ductal and acinar regions, especially observed in the small ductal region. In the aggregates of infiltrating cells, the cell remnants of salivary gland epithelia were scattered. Furthermore some of the epithelial cell remnants in aggregates of infiltrating cells could be recognized as epithelial masses which were composed of proliferated duct epithelial cells, though no typical structure of epimyoepithelial islands seen in Sjögren's syndrome was found. Anti-salivary duct antibody was detected in only one case.
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    URL: http://dx.doi.org/10.1007/BF00585496
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  • 52
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    Electronic Resource
    A morphological study of the changes which occur during pregnancy in the human breast (1983)
    Springer
    Virchows Archiv 401 (1983), S. 163-175 
    Details
    ISSN: 1432-2307
    Keywords: Breast ; Human ; Pregnancy ; Ultrastructure ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In this study the structural changes which occur during human pregnancy were examined by light and electron microscopy. Pregnancy was associated with proliferation and differentiation of the epithelial cells within the lobules. Proliferation was continuous throughout pregnancy with a progressive increase in the size of the lobules. The highest level of mitosis was observed in the first trimester with lower levels in the second and third trimesters. Unexpectedly a number of apoptotic cells were observed during pregnancy. Differentiation was initiated in the second trimester with an increase in the amount of rough endoplasmic reticulum and the appearance of a hypertrophic Golgi body and lipid droplets within a number of epithelial cells. A number of small vacuoles were present close to the apical plasmalemma of a few epithelial cells. As the pregnancy proceeded there was an increase in the number of cells exhibiting these features. There was also an increase in the size of the lipid droplets and the number of apical vacuoles. The apical vacuoles which have not been described previously range in size from 150–600 nm with the contents of the larger vacuoles having a whorled or labyrinth-like appearance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692642
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    Effect of hyperthermic vesical irrigation with bleomycin on the ultrastructure of the well-differentiated tumour and non-tumorous mucosa of the human urinary bladder (1983)
    Springer
    Urological research 11 (1983), S. 131-137 
    Details
    ISSN: 1434-0879
    Keywords: Human bladder tumour ; Non-tumorous human bladder mucosa ; Hyperthermic vesical irrigation ; Bleomycin ; Ultrastructure ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Bladder tumours and non-tumorous bladder mucosa were studied by scanning and transmission electron microscopy in seven patients who had undergone hyperthermic vesical irrigation with bleomycin. The treatment induced sloughing of the outermost tumour cells, an increase of blebs and a decrease of cytoplasmic processes of the deeply located tumour cells as well as cellular degeneration. Although less severe, non-tumorous mucosa showed similar changes. Microvilli also appeared on the superficial cells of non-tumorous mucosa after the treatment. This treatment is effective by inducing cell degeneration and desquamation but not selective to the bladder tumour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257718
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    Ultrastructural study of the mouse antimesometrial decidua (1983)
    Springer
    Anatomy and embryology 166 (1983), S. 263-274 
    Details
    ISSN: 1432-0568
    Keywords: Decidua ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of mouse antimesometrial decidual cells was analyzed during the development of the decidua between days 5 and 8 of pregnancy. The first decidual cells, appearing on the 5th day, are polygonal with rounded nuclei and prominent nucleoli; free ribosomes predominate in the cytoplasm. On the 6th to the 8th days the cytoplasm of these cells is typically that of cells actively engaged in macromolecular synthesis. Large numbers of granular and agranular endoplasmic reticulum cisternae are present in addition to well-developed Golgi complexes, mitochondria and lysosomes. Many bundles of microfilaments and lipid droplets occur during this period. An intense accumulation of autophagosomes and lysosomes with very heterogeneous content was noted on the 7th and especially the 8th days. The presence of these organelles is an indication that involution of this part of the decidua has begun.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305087
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    Ultrastructure of the absorptive cells in the small intestine of the rat during starvation (1983)
    Springer
    Anatomy and embryology 168 (1983), S. 331-339 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Starvation ; Absorptive cells ; Small intestine ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the absorptive cells in the duodenum, jejunum and ileum after 7, 14 and 21 days of starvation was investigated using rats aged from 12 to 18 months weighing about 500 g. In the basal cytoplasm of the absorptive cells (in the duodenum and ileum of 21-day-starved rats and the jejunum of 14- and 21-day-starved rats), the following changes were found: atrophied mitochondrion-like bodies, small vesicles, a short and sparse rough-surfaced endoplasmic reticulum and a lack of density in a portion of the cytoplasm. Moreover, many autolysosomes of various sizes and shapes were encountered in the basal cytoplasm; occasionally these elements accumulated and appeared to fuse to one another. In contrast, in the apical cytoplasm of absorptive cells in the intestine of starved rats, the ultrastructure was similar to that of control rats. It was considered that the apical cytoplasm of the absorptive cells in the starved rat intestine might be preserved as long as possible during starvation in order to absord nutrients when they become available again.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304271
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    An ultrastructural study of experimental high velocity penetrating head injury (1983)
    Springer
    Acta neuropathologica 59 (1983), S. 277-282 
    Details
    ISSN: 1432-0533
    Keywords: Trauma ; Missile head injury ; Astrocyte ; Blood brain barrier ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental high velocity missile brain injury in the rhesus monkey produces widespread swelling of perivascular astrocytes within 30 min of injury. Possible mechanisms for this lesion include a direct effect of force, chemical mediation secondary to the extravasation of blood, alterations in the permeability of the blood brain barrier and ischaemia. The implications of this finding for the function of the blood brain barrier, for neurotransmission and for neuronal survival are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691493
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    Oligodendroglioma-like cells (clear cells) in ependymoma (1983)
    Springer
    Acta neuropathologica 62 (1983), S. 141-144 
    Details
    ISSN: 1432-0533
    Keywords: Ependymoma ; Clear cells ; Oligodendroglioma-like cells ; Mixed glioma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A brain tumor of a 22-year-old man was composed mostly of round cells with perinuclear halos (clear cells), forming clusters intersected by small blood vessels. In some areas, the tumor cells showed perivascular arrangement and epithelial pattern. Phosphotungstic-acid hematoxylin stain and immunoper-oxidase stain for glial fibrillary acidic protein (GFAP) technique failed to stain the clear cells. Electron microscopy of the clear cells revealed them to be classical ependymoma cells with well developed intercellular junctions, microvilli and cilia. As no reporters in the past showed the evidence to clarify the nature of the clear cells, this case is considered a good example to support the viewpoint that the clear cells (oligodendroglioma-like cells) commonly observed in ependymomas are in reality ependymoma cells. It is stressed that the diagnosis of “mixed glioma” or “oligoependymoma” should be made with sufficient caution despite the recent advances of GFAP technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00684931
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    Cerebral ischemia in the rat: Ultrastructural and morphometric analysis of synapses in stratum radiatum of the hippocampal CA-1 region (1983)
    Springer
    Acta neuropathologica 61 (1983), S. 52-60 
    Details
    ISSN: 1432-0533
    Keywords: Ischemia ; Brain ; Hippocampus ; Synapses ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 10-min long ischemic insult followed by up to 60-min survival results in several changes of the synaptic ultrastructure in the hippocampal CA-1 region. The alternations consist of gradual change of synaptic curvature from neutral to positive, cleavage and decrease in thickness of the postsynaptic densities and, in the case of many terminals, wrinkling of their profiles. The most striking form of damage are membrane discontinuities which begin to appear in very small numbers after 20 min of blood reflow and become much more pronounced after 60 min. The development of those modifications seems to be time-related, whereas decrease in the number of synaptic vesicles, as shown by the morphometric analysis, occurs after 10 min and does not progress any further after 20 and 60 min. This decrease is most pronounced in the immediate vicinity of the presynaptic membrane. Although the observed signs of ultrastructural alternations of synapses in the postischemic period appear to conform to the general pattern of synaptic degeneration observed under other conditions, the severity of ischemia is underlined with the rate at which those changes develop, thus pointing toward grossly disturbed metabolism of postischemic neurons. Recently, a number of theories have been advanced, discussing significance of ischemic destruction of membrane phospholipids. These theories are discussed in the context of membrane discontinuities reported in this investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688386
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    Neuropathological findings of an autopsy case of adult β-galactosidase and neuraminidase deficiency (1983)
    Springer
    Acta neuropathologica 61 (1983), S. 283-290 
    Details
    ISSN: 1432-0533
    Keywords: β-Galactosidase and neuraminidase deficiency ; Neuronal inclusion bodies ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An autopsy case of a Japanese male with familial β-galactosidase and neuraminidase deficiency is reported. The clinical picture was characterized by adult onset, a gargoyle-like face, cerebellar ataxia, myoclonus, convulsions, retinal degeneration and cortical blindness. Histopathologically, most neurons seemed to have become degenerated in the whole cerebral cortex. Moreover, the calcarine cortex appeared spongy with depopulation of nerve cells. Stuffed neurons or neuronal storage changes were found throughout the brain, especially in the motor nuclei of the spinal cord and brain stem. The inclusions in the stuffed neurons revealed various profiles on the electron microscope. They were composed of membranous lamellar and/or multilamellar structures, often accompanying vacuoles and reminiscent of lipofuscin-like profiles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691999
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    Ultrastructural study on nervous system of fetus with GM1-gangliosidosis type 1 (1983)
    Springer
    Acta neuropathologica 61 (1983), S. 15-20 
    Details
    ISSN: 1432-0533
    Keywords: Ultrastructure ; Fetus ; Nervous system ; GM1-gangliosidosis type 1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The nervous system of a 22-week-old fetus with GM1-gangliosidosis type 1 was studied by electron microscopy. The tissues thus examined were the cerebral cortex at the parietal region, the cerebellum, the thoracic spinal cord, the Auerbach's myenteric plexus in the large intestine and the radial nerve fibers. In the cerebral cortex, membrane-bound vacuoles, which occasionally contained stacks of fine fibrils, were observed in the large young neurons in the deeper part of the cortical plate. The neurons in the other part of the cerebral cortex carried no storage materials. In the cerebellum, the membrane-bound vacuoles with stacks of fine fibrils were seen only in the Purkinje cells. The neurons in the spinal cord also contained several zebra-like bodies and the above membrane-bound vacuoles. As for the peripheral nervous system (PNS), neurons in the Auerbach's myenteric plexus carried membranous cytoplasmic bodies and zebra-like bodies. Some of the axons in the radial nerve fibers also contained a lot of pleomorphic electron-dense bodies and a few membranous cytoplasmic ones. These results show that the accumulation of storage materials is started in the large neurons which are produced in the early stage of neurogenesis in the central nervous system (CNS). Additionally, the observed membrane-bound vacuoles are considered to be structures which occur before the membranous cytoplasmic bodies and/or the zebra-like bodies. It is also elucidated that the PNS is affected earlier than the cerebral and cerebellar cortices and thoracic spinal cord.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688381
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    Specific ultrastructural markers of human pinealomas (1983)
    Springer
    Acta neuropathologica 62 (1983), S. 31-40 
    Details
    ISSN: 1432-0533
    Keywords: Human pinealomas ; Ultrastructure ; Specific markers ; Pinealocyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of four pinealomas was carried out to precise eventual specific markers. Dark and clear cells joined with zonulae adherents, extensive and pleiomorphous processes, a complex vacuolar system, and characteristic organelles (lysosome-like structures, clear and dense-core vesicles, vesicle-crowned rodlets and related structures, microtubular sheaves and centriolar derivatives, membranous whorls, fibrous bodies, microtubules, heterogeneous cytoplasmic inclusions) offered a typical pattern. No correlation could be made between the histological and ultrastructural features. The authors stress the ultrastructural similarities between the human tumor cells and the mammalian pineal cells. Pinealomas appeared as a morphological entity distinct from neuronal and astrocytic tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00684917
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    Uterine glands of the pig during pregnancy (1983)
    Springer
    Anatomy and embryology 166 (1983), S. 121-134 
    Details
    ISSN: 1432-0568
    Keywords: Uterine glands ; Pig ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the porcine uterine glands is described from material taken from 11 pregnant pigs at exactly known stages of gestation (day 30; 58; 80; 100; 110). Fixation was performed by perfusion via a branch of the uterine artery and the tissue was routinely processed for electrom microscopy. Additionally, cytochemical studies (phosphotungstic acid reaction for glycoproteins, according to Rambourg 1967; acid phosphatase reaction; ultrastructural localization of cellular iron, according to Parmley et al. 1978) were performed. On day 30 of pregnancy the uterine glands are coiled, simple tubular glands with a narrow lumen. The epithelial lining is simple columnar and consists basically of two cell types, ciliated cells and secretory cells. The secretory activity of the glandular epithelium is low; only a few secretory granules are present in the supranuclear cytoplasm. At midpregnancy the ultrastructure of the glands has significantly changed and the cells now show all the characteristics of high secretory activity: numerous parallel cisternae of rough endoplasmic reticulum, an extensively developed Golgi apparatus and many secretory granules which give a positive reaction for acid phosphatase and glycoproteins. The lumina of the glands are significantly enlarged and filled with a great amount of a granular, acid phosphatase-positive material. In the last third of pregnancy, only minor changes in the ultrastructure of the uterine glands are observed. The secretory activity is still high. The amount of rough endoplasmic reticulum has further increased and parallel arrays of cisternae occupy a considerable part of the supranuclear cytoplasm. The importance of the uterine secretion for embryonic nutrition and development is only partly understood. One of the secreted glycoproteins, uteroferrin, is believed to play an important role in the iron transfer from mother to fetus. From midpregnancy onward, a special cell type, the “granule laden cell” is found scattered between normal secretory cells of the uterine glands. Contrary to the opinion of Perry and Cromby (1982), we could demonstrate that these cells frequently extend to the lumen of the gland; hence the term “basal cell” seems inappropriate for this cell type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317948
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    A fine structural study of the cells that proliferate in the partially denervated dentate gyrus of the rat (1983)
    Springer
    Anatomy and embryology 166 (1983), S. 317-332 
    Details
    ISSN: 1432-0568
    Keywords: Dentate gyrus ; 3H-thymidine ; Glial cells ; Proliferation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tritiated thymidine autoradiography has established that after interrupting the commissural afferents to the dentate gyrus a number of non-neuronal cells proliferate in the molecular layer. In the present study the fine structure of the proliferating cells was analyzed by reembedding the 2-μm thick plastic sections of the dentate gyrus which had been previously coated with a nuclear emulsion and processed for light microscopic autoradiography. The location of the labeled cells was plotted with a camera lucida and a few ultrathin sections were taken from the re-embedded sections. In these the labeled cells were re-identified and photographed in an electron microscope. Most of the identified proliferating cells exhibited the following morphological features: The nuclei were irregularly oval, sometimes with deep indentations and contained dense clumps of chromatin; their diameters ranged between 4.5 and 6.5 μm. The cytoplasm was generally disposed to one side of the nucleus and often extended into a few broad processes. The Golgi apparatus was well developed. Many rosettes of free ribosomes were scattered throughout the cytoplasm, and the rough endoplasmic reticulum usually consisted of a few short cisternae. Small multilamellated bodies were common, but dense inclusion bodies were infrequent. The observations reported in this paper suggest: 1. that the nonneuronal cells which proliferate in a neuropil undergoing a mild denervation are morphologically closely related to microglia; 2. that in young adult animals these cells do not seem to have been previously involved in intense phagocytic activity; and 3. that the proliferating cells are present in the neuropil at the time of the denervation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305921
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    Effect of prepuberal castration on porcine bulbospongiosus muscle (1983)
    Springer
    Anatomy and embryology 168 (1983), S. 51-58 
    Details
    ISSN: 1432-0568
    Keywords: Bulbospongiosus muscle ; Histochemistry ; Ultrastructure ; Castration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histochemical profile and ultrastructural properties of the bulbospongiosus muscle (BSM) fibers from 5–6 month old boars and barrows (castrated at 7 days of age), and intact week old piglets were compared. Based on myosin ATPase, preincubated at pH 4.2, BSM of boars contained predominately intermediately staining fibers, whereas BSM of barrows and piglets had a mixture of staining intensities. Fibers from boar BSM stained intensely for SDH, with subsarcolemmal and diffuse location of reaction product. Staining intensity for SDH was variable in BSM from barrows and piglets, with diffuse location of reaction product. The BSM of boars and barrows contained predominately dark fibers when stained for glycogen and phosphorylase, and the fibers were low in stored lipids. While the fibers were smaller in barrow as compared to boar BSM, ultrastructural differences between boar and barrow BSM were not detectable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305398
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    Studies of the guinea pig epididymis (1983)
    Springer
    Anatomy and embryology 168 (1983), S. 195-209 
    Details
    ISSN: 1432-0568
    Keywords: Epididymis ; Guinea pig ; Principal cells ; Zonula occludens ; Zonula adhaerens ; Ultrastructure ; Freeze fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The junctional complexes of the principal cells in the guinea pig epididymis were analyzed using freeze fracture and ultrathin section goniometric techniques. Replicas of the seven regions (I to VII) investigated reveal a continuous decrease in the number of tight junctional strands, ranging from 15.73±3.54 in zone I (proximal) to 4.39±0.78 in zone VII (distal tubule). The distance from the adluminal to the basolateral strand also diminishes from proximal, 0.73±0.02 μm to distal, 0.19±0.03 μm. The junctional strands appear on the P-face and anastomose forming compartments which are larger in the basolateral areas than those in the apical. The network of strands frequently form terminal loops and blind endings towards the more basal parts of the lateral membrane. Freeze fracture images also exhibit randomly distributed particulate aggregations which correspond to maculae adhaerentes, the highest number of which are found in zone IV, V, and VII. Desmosomal figures are found not only below, but also adjacent and intermingled among the tight junctional strands. This special junctional arrangement is confirmed upon goniometric analysis of ultrathin sections from zones IV, V, and VII. Electron dense desmosomal plaques are seen parallel and directly subjacent to the membranes of the tight junctions, following the strands in both directions to finally converge on the punctiform connections. Goniometry also reveals a dense feltwork of material closely applied along the lateral cell border. These zonulae adhaerentes are seen to be of greatest length and density in zones I, VI, and VII.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315816
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    An ultrastructural study of lactation in the human breast (1983)
    Springer
    Anatomy and embryology 168 (1983), S. 349-359 
    Details
    ISSN: 1432-0568
    Keywords: Breast ; Human ; Lactation ; Ultrastructure ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In this study the morphological features of lactation in the human breast were examined by scanning and transmission electron microscopy. The lactating lobules comprised large numbers of interconnecting acini which were lined by a single layer of epithelial cells with underlying myoepithelial cells. Marked variations were noted in the shape of the epithelial cells. The myoepithelial cells formed an open meshwork of interconnecting cytoplasmic processes packed with myofibrils. The basal cytoplasm of the epithelial cells was packed with rough endoplasmic reticulum while the apical cytoplasm contained a hypertrophic Golgi body, numerous vacuoles (a few of which contained casein micelles), a number of lipid droplets and small coated and uncoated vesicles. The lipid droplets were released by progressive protrusion from the apical surface. They remained covered by the plasmalemma and were finally budded off into the lumen. In certain cases a portion of cytoplasm was released with the lipid droplet. The vacuoles and small vesicles fused with the plasmalemma and released their contents by exocytosis. Within the samples the majority of epithelial cells were actively lactating although examples of undifferentiated “resting” and dead (lysed) cells were also identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304273
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    Studies of the guinea pig epididymis (1983)
    Springer
    Anatomy and embryology 168 (1983), S. 173-194 
    Details
    ISSN: 1432-0568
    Keywords: Epididymis ; Guinea pig ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The guinea pig epididymis is subdivided into seven zones. The ultrastructure and morphology of the principal cells in these zones is analyzed. The position, shape and content of the nuclei are variable along the length of the epididymal duct. Features characteristic of absorptive activity, such as micropinocytotic caveolae, vacuoles, and multivesicular bodies are of high concentration in zone IV and VI. The Golgi apparatus, rough endoplasmic reticulum and secretion granules are organelles and inclusions implicated to secretory functions and in this study are not found in the following concurring amounts within the principal cells of the seven zones: the Golgi apparatus exhibits a trend of increase from zone II to zone VII while the rough endoplasmic reticulum decreases. Secretion granules, though, are detected only in zones II and III, not only in the supra-, but also in the peri-and infranuclear regions. This possibly implies an exocrine secretory functions. Lamellar whorls and profiles of tubular smooth endoplasmic reticulum are concentrated in the supranuclear and adluminal regions of zones I, II and VI. A high concentration of large lipid droplets is a consistent feature of the perinuclear region of zone II. Mitochondia and lysosomes are detected in relatively large amounts along the epididymal duct. The correlations of these morphological characteristics with respect to their possible functional role are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315815
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    Neurofibromatosis tumor and skin cells in culture (1983)
    Springer
    Acta neuropathologica 61 (1983), S. 275-282 
    Details
    ISSN: 1432-0533
    Keywords: Neurofibromatosis ; Cell culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Skin fibroblasts and tumor cells were cultured from four patients with peripheral von Recklinghausen's neurofibromatosis (NF). The cell type enriched in culture from the tumors carried the fibroblastic Thy 1.1. cell surface antigen and produced fibronectin, like fibroblasts from skin of NF-patients or from control persons. In electron micrographs the NF tumor and NF skin cells were similar to the control skin fibroblasts; elongated in shape, contained tubular mitochondria, variable amounts of granular endoplasmic reticulum, numerous lysosomal inclusion bodies and collections of 5 nm filaments. Trypsinized cells were fractionated with centrifugation in a Percoll density gradient. All cell lines produced only one sharp band of viable cells at the buoyant density of 1.03. Compared with the NF skin or control skin fibroblasts the NF tumor cells, however, produced a less well organized peri-and extracellular matrix estimated from fibronectin fluorescence. The nuclear sizes were measured from photographs of the cultures. The nuclei of all four tumor cell lines were larger than those of the skin fibroblasts of the corresponding patients. Neurofibromatosis tumor cells thus resemble skin fibroblasts in their density and in some ultrastructural properties but are different in their growth pattern and synthetic functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691998
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    Pituitary adenomas: Immunohistology and ultrastructural analysis of 118 tumors (1983)
    Springer
    Acta neuropathologica 62 (1983), S. 1-14 
    Details
    ISSN: 1432-0533
    Keywords: Pituitary adenomas ; Immunohistology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An analysis is presented of the immunohistological and ultrastructural features in a series of 118 surgically removed pituitary adenomas all of which were studied immunohistologically using antisera to growth hormone (GH), prolactin (PRL) ACTH, βFSH, βLH and βTSH, and 75 of which were studied ultrastructurally. Results were analysed according to the mode of presentation of patients. Forty-one (35%) of the tumours were from patients with acromegaly or gigantism, ten (9%) from patients with Cushing's syndrome or Nelson's syndrome, 19 (16%) from patients with clinical features associated with hyperprolactinaemia and 48 (40%) from patients with space occupying lesions which appeared clinically to be overtly endocrinologically functionless. By light microscopy, using the immunoperoxidase (PAP) technique, immunoreactive GH was demonstrated in all the tumours from patients with acromegaly or gigantism, immunoreactive ACTH in all tumours from patients with Cushing's syndrome or Nelson's syndrome and immunoreactive PRL in 95% of tumours associated with effects of hyperprolactinaemia. Forty-five percent of the tumours from acromegalic patients contained some PRL-positive cells as well as GH-positive cells. Among the tumours which appeared clinically to be endocrinologically functionless were three tumours (from males) uniformly stained for immunoreactive PRL. Of the remainder, 60% were negative for immunoreactive hormones and 40% contained small numbers of cells which were positive for a variety of immunoreactive hormones. ACTH-cell and PRL-cell tumours had ultrastructural features as described in previous studies. Fifty percent of GH-cell tumours examined at the EM level contained fibrous bodies, while in the remainder these structures were not identified. Tumours with fibrous bodies were more likely to contain PRL as well as GH with immunoperoxidase. All tumours that were endocrinologically functionless and which were examined at the EM level contained secretory granules. Oncocytic change was common in these tumours. No ultrastructural differences were observed between those which contained immunoreactive hormones by light microscopy and those which did not.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00684914
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    An ultrastructural study of epidermolytic leukoplakia (1983)
    Springer
    Archives of dermatological research 275 (1983), S. 86-91 
    Details
    ISSN: 1432-069X
    Keywords: Vermilion of the lip ; Leukoplakia ; Epidermolytic hyperkeratosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A leukoplakic lesion of the lip showing the histologic features of epidermolytic hyperkeratosis above solar elastosis was investigated by electron microscopy. The ultrastructural alterations observed in the upper epidermal layers corresponded in the main with those of epidermolytic hyperkeratosis in other skin diseases. The keratinocytes showed irregularly formed tonofilaments, a marked intracellular edema, and premature cornification. In addition, there were discrete subcellular signs of premalignancy in the cells of the basal and suprabasal layers. These alterations suggest that the epidermolytic leukoplakia represents a rare histopathologic variant of actinic cheilitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412880
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  • 71
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    Electronic Resource
    Ultrastructural localization of adenylate cyclase and cAMP phosphodiesterase in the gastrulating chick embryo (1983)
    Springer
    Development genes and evolution 192 (1983), S. 42-44 
    Details
    ISSN: 1432-041X
    Keywords: Chick embryo ; Gastrulation ; Adenylate cyclase ; cAMP phosphodiesterase ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructural localization of adenylate cyclase (E.C. 4.6.1.1.) and cAMP phosphodiesterase (PDE) (E.C. 3.1.4.17.) in the ectoderm of the developmental stage 4 chick embryo was studied. Adenylate cyclase was localized in the lateral surfaces of the ectodermal cells. In the primitive streak cells the enzymatic activity was observed on all the lateral surfaces, whereas in the periphery of the blastoderm the reaction product was localized in the apical parts of the lateral plasma membranes only. cAMP PDE localized in the apical cytoplasm of the ectodermal cells, with highest activity in the globular projections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848768
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  • 72
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    Electronic Resource
    Electron microscopical study of self-differentiation potency in the chick embryonic endoderm cultured in vitro (1983)
    Springer
    Development genes and evolution 192 (1983), S. 171-178 
    Details
    ISSN: 1432-041X
    Keywords: Differentiation ; Digestive tract ; Endoderm ; Organ culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The self-differentiation potency of the endoderm of the chick embryo was investigated mainly by transmission electron microscopy. Endodermal fragments isolated from 4- to 6-day stomach or small intestine were cultured in the absence of mesenchyme and were able to differentiate in vitro into organ-specific epithelia. Endodermal fragments isolated from the stomach region differentiated into a pseudo-stratified epithelium with periodic acid Schiff-positive mucous granules in the apical cytoplasm, while those from the small intestinal region differentiated into a simple columnar epithelium with a striated border which was positive in alkaline phosphatase activity. These features are comparable with those of the mucous secretory epithelium of the normal embryonic stomach and the absorptive epithelium of normal embryonic small intestine, respectively. Next, the self-differentiation potencies were investigated of the upper and lower layers of the blastoderms, at stages 1–5 of Hamburger and Hamilton (H. and H.). Both stomach-type and small-intestine-type epithelia developed only when fragments of the lower layer isolated from the blastoderms older than stage 3 of H. and H. were cultured, suggesting that cells possessing the potency to differentiate into the stomach- and small-intestine-type epithelia exist in the definitive endoderm at the beginning of its formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848687
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  • 73
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    Electronic Resource
    Immunoagglutination of type-C virus particles in a human T-cell line by serum supplementation from patients with adult T-cell leukemia (1983)
    Springer
    Journal of cancer research and clinical oncology 105 (1983), S. 106-108 
    Details
    ISSN: 1432-1335
    Keywords: Human T-cell line ; Type-C virus particles ; Adult T-cell leukemia ; Immunoagglutination ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A T-cell line, MT-2, derived from human cord blood lymphocytes by cocultivation with adult T-cell leukemia (ATL) cells is a continuous producer of type-C virus particles. Electron microscopy of MT-2 cells cultured for 1–3 weeks in medium containing 10% ATL patients' sera revealed agglutination of type-C virus particles within the electron-dense deposits in the extracellular spaces. No such agglutination occurred in control cultures supplemented with normal human or fetal calf serum. These results provide direct evidence for the specific reactivity of ATL patients' sera with type-C virus particles in the MT-2 cell line at the ultrastructural level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00391841
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  • 74
    Electronic Resource
    Electronic Resource
    Ultrastructural demonstration of a projection from the flocculus to the nucleus prepositus hypoglossi in the cat (1983)
    Springer
    Experimental brain research 51 (1983), S. 192-198 
    Details
    ISSN: 1432-1106
    Keywords: Flocculus ; Nucleus prepositus hypoglossi ; Ultrastructure ; Degeneration ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Small electrolytic lesions were made in the flocculus of two adult cats by means of a stereotactic approach avoiding any damage to the cerebellar nuclei. After a survival time of 3 days the animals were killed and the brains fixed and prepared according to standard procedures for ultrastructural studies. The brains of two unoperated cats were similarly treated and served as normal controls. In the experimental animals a large number of boutons in the rostral part of the nucleus prepositus hypoglossi (Ph) ipsilateral to the floccular lesion showed degenerative changes. These were characterized by hypertrophy, a prominent aggregation of densely packed parallel tubules or concentric arrays of cisternae and a filamentous hyperplasia. Only very rarely were such abnormal boutons seen in the caudal half of the ipsilateral Ph, or on the contralateral side or in the unoperated animals. The degenerating boutons contain clusters of pleomorphic vesicles and they establish symmetrical synaptic contacts with somata, dendritic shafts and dendritic spines. Some of the degenerating boutons appear to be of the en passant type. These findings thus affirm the existence of a direct flocculo-prepositus projection in the cat. It is suggested that this pathway could be responsible for mediating information about eye position and velocity to Ph neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237194
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  • 75
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    Electronic Resource
    Ultrastructure of tuberculate spores in Streptomyces thermoviolaceus (1983)
    Springer
    Archives of microbiology 134 (1983), S. 295-298 
    Details
    ISSN: 1432-072X
    Keywords: Actinomycetes ; Streptomyces thermoviolaceus ; Sporogenesis ; Spore ornamentation ; Cupular knobs ; Sheath ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sporogenesis of aerial spores in Streptomyces thermoviolaceus corresponded to a common sporulation type in the genus. The sporulation septum was composed of an outer ring-shaped constriction wall and an inner interspace septum arising by the inwards growth of a double annulus. In mature spores the wall was composed of two layers, the outer one was part of the parent hyphal wall and septum material, the inner one was formed de novo. The spore chains were enclosed by the thin breakable sheath containing small rod-like elements. The ornamentation in the form of knobs, which were a characteristic feature of the species originated from the sheath. The knobs were hemispherical particles with an inner electron dense core and an outer electron transparent shell. The term “cupular knobs” was suggested for this type of tuberculate ornamentation. Frequently, the knobs became detached from the surface in which case the inner core separated easily from the shell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00407805
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  • 76
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    Electronic Resource
    Chroococcus S24 and Chroococcus N41 (cyanobacteria): morphological, biochemical and genetic characterization and effects of water stress on ultrastructure (1983)
    Springer
    Archives of microbiology 135 (1983), S. 81-90 
    Details
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Ultrastructure ; Nitrogen fixation ; Water stress ; Taxonomy ; DNA ; Plasmids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two strains of desiccation-tolerant coccoid cyanobacteria, Chroococcus S24, a marine form, and Chroococcus N41, a cryptoendolith isolated from a hot-desert rock, have been characterized. The mol % DNA base compositions of the strains are 47.1 and 48.9% respectively. Plasmid DNA was not detected in either strain. The pigment contents and nutritional characteristics of the strains are identical. Both lack phycoerythrinoid pigments and, in culture, behave as slow-growing halotolerant marine forms with elevated requirements for Na+, Cl−, Mg2+ and Ca2+. Sucrose was the only carbon source of those tested that supported photoheterotrophic growth. Each strain synthesizes nitrogenase under anaerobic conditions but not in air. Morphologically the two strains are indistinguishable. They are considered to be independent isolates of the same cyanobacterial species. Chroococcus N41 was studied in detail with the electron microscope. When brought to equilibrium at matric water potentials of-168 MPa and lower (to-673 MPa=c0.12a w) the protoplast shrinks, but the cells maintain the same size and diameter as those at-2,156 kPa (MN medium; control); the sheath expands and remains attached to the cell wall outer membrane by fibrils. The cell wall, cell membrane, thylakoid membranes, cyanophycin granules and carboxysomes appeared intact in desiccated cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00408014
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  • 77
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    Electronic Resource
    Achilles tendon injury (1983)
    Springer
    Virchows Archiv 399 (1983), S. 177-189 
    Details
    ISSN: 1432-2307
    Keywords: Achilles tendon ; Tendon injuries ; Muscles ; Myofibrils ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unilateral tenotomy of the Achilles tendon was carried out in 60 rabbits. The limb was then either mobilized directly or immobilized for 10 to 35 days using a plaster usually after tendon suture. In certain cases the plaster was removed early (on the 7th or 16th day) and the animals were than allowed to use this leg. Separation between tendon ends was apparent from steel markers, placed close to each cut end of the tendon and examined by X-ray. The separation curve was biphasic and both the first and the inactive phase reflected the degree of tension over the tendon suture. However, during the second separation phase, which began between the 17th and 21st day, the separation gradually reached the same level in all groups. Enzyme histochemistry and electron microscopy revealed severe degenerative changes in immobilized and in shortened muscles. Furthermore, a gradual shift in fibre type characteristics from type 1 slow-twitch fibres towards type 2 fast-twitch fibres occurred. Rapid recovery followed removal of the plaster. The findings indicated that both degenerative and regenerative processes and adaptive processes had been initiated in all experimental muscles when the tendon continuity was broken. The adaptive processes progressed gradually during the five-week post-operative period and might have been responsible for the second phase of the tendon end separation. The fibre adaptation, i.e. the transformation, may be accounted for by changes in structure of the myofibrils and composition of the myosin molecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00619578
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  • 78
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    Electronic Resource
    Pituitary hyperplasia (1983)
    Springer
    Virchows Archiv 399 (1983), S. 277-287 
    Details
    ISSN: 1432-2307
    Keywords: Pituitary ; Hyperplasias ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Surgical specimens of 15 normal and 106 para-adenomous anterior pituitaries were studied immunocytochemically and in part electron microscopically for the presence of hyperplasia. GH cell hyperplasia was found in 13% of all normal pituitaries, in 6% of the cases with Prolactin secreting adenomas and in 9% of the cases with ACTH secreting adenomas. Prolactin cell hyperplasia occured in nearly equal percentages (17–23%) in normal pituitaries and in areas adjacent to GH-, Prolactin-or ACTH-secreting adenomas or adjacent to inactive adenomas. Previous findings of relatively more frequent Prolactin cell hyperplasia occuring together with Prolactin producing adenomas have to be revised. Prolactin cell hyperplasia as a primary source of hyperprolactinemia is very rare and almost always occurs in conjunction with oncocytic adenomas. ACTH cell hyperplasia was found in 13% of the normal pituitaries, in 14% of the cases with Prolactin secreting adenomas, in 58% of the cases with ACTH producing adenomas and in 40% of the pituitaries with GH secreting adenomas. We have no explanation for the latter result. ACTH cell hyperplasia may be the primary cause of Cushing's disease (18% of all Cushing cases). Hyperplasia of TSH cells in normal pituitaries was rare (7%) and with the exception of Prolactin producing adenomas (22%) was not found near adenomas. Clinical-pathological correlations are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00612945
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  • 79
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    Electronic Resource
    Undifferentiated carcinoma of the parotid gland (1983)
    Springer
    Virchows Archiv 401 (1983), S. 89-97 
    Details
    ISSN: 1432-2307
    Keywords: Undifferentiated carcinoma ; Parotid gland ; Myoepithelial cell ; Epithelial cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of undifferentiated carcinoma of the parotid gland were studied by light and electron microscopy. Light microscopy showed nests of ovoid cells with scanty cytoplasm and pyknotic nuclei in two cases. One case was the small-cell type, and another one was the large-cell type histopathologically. Electron microscopy showed two distinct cell types in each tumor: Case 1 (small-cell type). — An epithelial-like cell, and an irregular-shaped cell containing bundles of filaments suggesting myoepithelial differentiation. Case 2 (large-cell type). — An epithelial-like cell, and a large cell containing secretory-like granules. These findings support a salivary duct epithelial origin for these tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00644792
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  • 80
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    Electronic Resource
    Ultrastructure of catecholamine-containing axons in the intestine of the domestic fowl (1983)
    Springer
    Cell & tissue research 234 (1983), S. 411-425 
    Details
    ISSN: 1432-0878
    Keywords: Intestines (chicken) ; Innervation ; Catecholamines ; Adrenergic fibres ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Axons in the duodenum, ileum and rectum of the domestic fowl were identified as catecholamine-containing (CA) on the basis of positive reactivity following chromaffin fixation for electron microscopy. CA-axons in association with blood vessels in all regions of the intestine and in non-vascular sites in the small intestine had a ‘ typical’ adrenergic appearance, in that they contained many small granular vesicles (SGV) and variable numbers of large granular vesicles (LGV). In the rectum the non-vascular CA-axon profiles were atypical, in that there were many elongated LGV and few SGV, and the chromaffin reactivity was weak. The nerve profiles in the rectum were dramatically reduced following 6-hydroxydopamine and reserpine treatment and were absent in rectum cultured in the absence of extrinsic ganglia. It was concluded that the profiles, in spite of their low chromaffin reactivity, truely represent CA-axons. The possibility was raised that the atypical morphology and reduced chromaffin reactivity is due to the presence of adrenaline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213778
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  • 81
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    Electronic Resource
    Ultrastructural identification of corticotropes of the fetal rat (1983)
    Springer
    Cell & tissue research 234 (1983), S. 427-437 
    Details
    ISSN: 1432-0878
    Keywords: Corticotropes ; Rat fetus ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Corticotropes of rat fetuses aged 16, 18 and 21 days were localized by the indirect antibody-enzyme method on semithin sections of the pituitary. The development of the ultrastructure of these cells was observed on consecutive ultrathin sections. In comparison with previous data our present results show that identification of a fetal cell type cannot be based entirely on morphological criteria. The structural peculiarities of corticotropes obtained from studies in vivo are compared with those observed in cells maintained in vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213779
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  • 82
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    Electronic Resource
    Cyclophosphamide-induced changes in rodent odontogenesis (1983)
    Springer
    Cell & tissue research 234 (1983), S. 679-689 
    Details
    ISSN: 1432-0878
    Keywords: Odontogenesis ; Rats ; Cyclophosphamide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cyclophosphamide-induced changes in rodent odontogenesis were investigated by light and electron microscopy in four-day-old Sprague Dawley rats given one injection of 40 mg/kg of body weight of cyclophosphamide and killed at intervals of one hour, one day, one week and two weeks. Incisor and molar teeth were dissected from the animals, fixed in 2.0% glutaraldehyde in 0.1 M sodium cacodylate with 3.4% sucrose, and subsequently some were incubated for alkaline phosphatase reaction, and embedded in Spurr's medium for sectioning at light- and electron-microscopic levels. From three days a cell-sparse zone was created in the pulp in the growing end of the tooth and progressive cellular changes were observed which became more severe in the one-week and two-week specimens. Subodontoblast and adjacent pulpal cells were the most affected showing nuclear changes, damage to, or loss of, organelles, and inclusion bodies. Odontogenic epithelium was less affected and odontoblasts appeared to be unaffected by the drug. A new irregular matrix was laid down in the defect area and seemed to be the product of depolarized odontoblasts. This new matrix showed alkaline phosphatase activity, as did the cells embedded in it, and later it became mineralized. It is speculated that the polarity of odontoblasts might be maintained by an intact subodontoblastic layer; when this is lost the odontoblasts become depolarized and capable of secreting matrix from both ends.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218659
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  • 83
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    Electronic Resource
    Isolation of metabolically active endothelial cells in high yield from bovine cavernous bodies (1983)
    Springer
    Cell & tissue research 232 (1983), S. 579-591 
    Details
    ISSN: 1432-0878
    Keywords: Cavernous bodies ; Endothelial cells ; Respiratory activity ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Work on endothelial cells has been limited by the availability of procedures for obtaining such cells in quantities adequate for direct in vitro analysis. The present paper describes a method for the isolation of endothelial cells from bovine cavernous bodies. A number of cells ranging from 2.5 to 4 × 108 per animal has been obtained. The cells were identified as follows 1) presence of the “Weibel and Palade” bodies in the isolated cells, 2) “cobblestone” appearance of cell cultures, and 3) presence of factor VIII, as demonstrated by immunofluorescence assays. The cell viability at the end of the purification procedure was tested 1) by dye-exclusion tests and 2) by metabolic assays. Features of this preparation are 1) the very high yield of viable endothelial cells, 2) the absence of contamination by fibroblasts and smooth muscle cells and a very low contamination by erythrocytes and 3) the fine dispersion of the isolated cells. These properties allow functional and subcellular fractionation studies on freshly isolated endothelial cells of microvascular origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216430
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  • 84
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    Electronic Resource
    Ultrastructural morphometry of the myocardium of Thunnus alalunga (1983)
    Springer
    Cell & tissue research 233 (1983), S. 427-438 
    Details
    ISSN: 1432-0878
    Keywords: Myocardium ; Thunnus alalunga ; Ultrastructure ; Mitochondria ; Myofibrils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The common ventricle in the heart of the Thunnus alalunga was studied. The ventricular myocardium consists of an outer compact layer and a thick inner spongy layer. The compact layer has slightly larger cells (4–6 μm diameter) than the spongy layer (2.5–5 μm diameter). Ultrastructurally the myocardium displays normal arrangements of myofibrils and mitochondria. The sarcoplasmic reticulum is poorly developed. The intercalated discs are simple with the fascia adherens being the most frequent junctional type observed; occasionally a desmosome was seen. Nexus type junctions are present but are unassociated with the intercalated discs. There are no t-tubules evident but the plasmalemma exhibits numerous caveolae which rarely form couplings with the sarcoplasmic reticulum. A morphometric analysis of the volume percent of mitochondria and myofibrils showed that the myocardial cells in the spongy layer of the heart have a significantly greater volume percentage of mitochondria than the compact layer. No significant differences were found between myocardial regions when the volume percentages of myofibrils were compared. The physiological studies revealed that the albacore tuna has heart rates (120 bpm) and ventricular blood pressures (100 mmHg) that are among the highest reported for fish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238308
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  • 85
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    Electronic Resource
    Ultrastructural and immunohistochemical studies of rat epididymis (1983)
    Springer
    Cell & tissue research 233 (1983), S. 523-537 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis (rat) ; Myosin ; Actin ; Fibronectin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anatomical distribution of smooth muscle actin, myosin, fibronectin and basement membrane has been investigated immunohistochemically, using the indirect immunofluorescence technique, in the rat epididymis. The findings were correlated with the ultrastructural organization of the organ. Actin was found to be distributed in the stereociliary region of the epithelial principal cells and in the terminal web region. Actin was also visible along the base of the epithelium. Myosin was detected in the terminal web and in the terminal bar regions of the epithelium. The contractile cells showed a strong stain for both proteins. Basement membrane immunoreactivity was distributed along the epithelial basement membrane and around the contractile cells of the wall. In the cauda, between the epithelium and the contractile cell layers, the lamina propria, containing blood vessels and a thin layer of cells, was negative for all antigens investigated. Fibronectin showed a granular distribution around the contractile cells, mainly in the cauda. The ultrastructural study showed only thin (5–6 nm in diameter) filaments in the stereocilia and terminal web region. Thin filaments were also visible in the cytoplasm of the basal cells, thus suggesting a contractile function of this cell type. The heterogeneous appearance of the contractile cells of the wall seemed to support the different contractile pattern of the epididymal regions: caput, corpus and cauda. The cells present in the lamina propria showed cytoplasmic vesicles with dark granules resembling the “A” cell granules of the endocrine pancreas and gut mucosa cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212222
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  • 86
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    Electronic Resource
    The structure and function of the nematocysts of Chironex fleckeri Southcott, 1956 (1983)
    Springer
    Cell & tissue research 233 (1983), S. 563-577 
    Details
    ISSN: 1432-0878
    Keywords: Nematocysts ; Structure ; Ultrastructure ; Function ; Cubozoa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microbasic p-mastigophores, euryteles of two size groups, holotrichous isorhizas and atrichous isorhizas, comprise the cnidom of Chironex fleckeri, a cubozoan that has been responsible for several human fatalities. In its undischarged state each microbasic mastigophore of C. fleckeri consists of a capsule containing matrix and an inverted tube possessing a smooth-walled butt which is loosely coiled helically and which narrows to form a thread that is tightly coiled helically and markedly pleated. Both butt and thread carry three helices of spines and contain a granular matrix. During discharge, the proximal butt spines form initially a piercing stylet. Granular material from the butt and thread is released prior to the release of capsular material. Each eurytele possesses a tube with a butt composed of three bulbs, the middle bulb bearing long spines. Each holotrichous isorhiza possesses a coiled tube bearing small spines along its length. Each atrichous isorhiza exhibits a tube that is devoid of spines and loosely folded in the undischarged condition. The probable role of each type of nematocyst is inferred from its structure and features that enable the ready separation of the nematocysts of C. fleckeri from those of scyphozoan jellyfish are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212225
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  • 87
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    Electronic Resource
    Ciliary epithelia of the mammalian eye in cultured explants (1983)
    Springer
    Cell & tissue research 233 (1983), S. 629-638 
    Details
    ISSN: 1432-0878
    Keywords: Ciliary process ; Cultured explant ; Epithelial cells ; Ultrastructure ; Bovine and rabbit eyes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural characteristics of ciliary epithelium from bovine, pigmented rabbit, and fetal albino rabbit were studied in cultured explants. The tips of ciliary processes were cultured in plastic dishes with Dulbecco Modified Eagle Medium (DMEM) containing 5% fetal bovine serum. More than half of the expiants adhered to the plastic culture dish, and epithelial cells spread as monolayers within a few days. Initially the explant contains two layers, the outer (nonpigmented cells) and the inner (pigmented cells). Later the explant exhibits three layers: 1) outermost lightly pigmented flattened cells, 2) an outer layer of nonpigmented cells, and 3) an inner layer of densely pigmented cuboidal cells. The cells of the outermost layer are continuous with the cells of the inner layer. A narrow space lies between the outermost layer and the outer layer. The columnar cells in the outer layer contain well developed organelles but no pigment granules; they possess a basement membrane, lateral interdigitations, and junctional complexes near their apices. Numerous focal junctions and some ciliary channel-like structures were detected between the columnar cells of the outer layer and the cuboidal cells of the inner layer. The cuboidal cells of the inner layer are filled with pigment granules. These observations suggest that the columnar cells of the outer layer are nonpigmented epithelium, the cuboidal cells of the inner layer are pigmented epithelium, and the flatened cells in the outermost layer are derived from pigmented epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212230
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  • 88
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    Ultrastructural observations on the formation of follicles in the human fetal thyroid (1983)
    Springer
    Cell & tissue research 233 (1983), S. 693-698 
    Details
    ISSN: 1432-0878
    Keywords: Thyroid gland ; Human fetus ; Follicles ; Ultrastructure ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thyroid glands from 40 human fetuses ranging from 30 to 175 mm in length were examined by electron microscopy. At the 30 mm stage, the cells are arranged in cords or clusters and contain numerous free ribosomes. The rough-surfaced endoplasmic reticulum (RER) is poorly developed and the Golgi complex consists of saccules, smooth and coated vesicles. Mitochondria, microfilaments, glycogen particles, occasional lysosome-like structures, and single cilia are observed. At sites of incipient follicle formation, intercellular clefts containing interdigitating microvilli, delimited by junctional complexes, are evident. In addition, the apical region of some cells contains vacuoles. At the 50-mm stage, intercellular clefts are more apparent, some of them organized into small follicles through the enlargement of the lumen, the incorporation of additional cells, and the formation of a basal lamina. With increasing gestational age, more follicles are established. The lumina vary from round to clover-leaf shaped and have an electron-dense content. Cisternae of RER are dilated and contain flocculent material. The Golgi complex is more extensive, and lysosome-like structures are more numerous. By the 100-mm stage, the follicular cells appear morphologically well differentiated. The results demonstrate an extracellular origin of the follicular lumen in the human fetal thyroid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212236
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  • 89
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    Electronic Resource
    Ultrastructural immunocytochemical localization of fibronectin in the developing rat lung (1983)
    Springer
    Cell & tissue research 234 (1983), S. 165-177 
    Details
    ISSN: 1432-0878
    Keywords: Fibronectin ; Lung ; Development ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In a previous study changes in the macrodistribution of fibronectin during rat-lung development were examined. Using the peroxidase-antiperoxidase immunocytochemical technique, we have demonstrated the presence of fibronectin in embryonic, neonatal, and adult rat lung at the ultrastructural level. In the embryo, fibronectin is found both in an intra-and extracellular association with isolated pneumoblasts, and in a periodic distribution along the basal lamina. The neonate displays fibronectin in an intracellular association with early type-I cells and on their basal and luminal surfaces, but not in association with type-II cells. Neonatal basal lamina is diffusely labeled by anti-fibronectin antiserum. Fibronectin in adult tissue is found both intracellularly and on the basal and luminal surfaces of type-I cells but not in type-II cells. The basal lamina and interstitial connective tissue are slightly or non-reactive. These observations confirm and extend our initial suggestion that fibronectin is involved in rat-lung development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217410
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  • 90
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    Electron microscopy of extracellular materials during the development of a sea star, Patiria miniata (Echinodermata: Asteroidea) (1983)
    Springer
    Cell & tissue research 234 (1983), S. 193-200 
    Details
    ISSN: 1432-0878
    Keywords: Sea star ; Development ; Cuticle ; Extracellular materials ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of conspicuous extracellular materials during the life history of a sea star (Patiria miniata) is described. The outer surface of the developing sea star is covered by two morphologically different cuticles that appear sequentially during ontogeny. The primary cuticle, which is about 120 nm thick and two-layered, is present from mid-blastula through the end of the larval stage. The secondary cuticle, which is about 1 μm thick and three-layered, first appears on the epidermis of the rudiment region of the larva and, after metamorphosis, covers the entire epidermis of the juvenile and adult stages. During ontogeny, there are only two conspicuous gut cuticles: the first lines the newly invaginated archenteron at the start of the gastrula stage, and the second lines the esophagus during the larval stage. A blastocoelic basal lamina first appears at mid-blastula and persists as subectodermal and subendodermal basal laminae. Ruthenium red-positive granules are detectable between the lateral surfaces of adjacent ectodermal cells during part of the gastrula stage; this transient intercellular material may possibly aid in lateral adhesion between cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217412
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  • 91
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    Electronic Resource
    Changes in plastid ultrastructure during iron nutrition-mediated chloroplast development (1983)
    Springer
    Protoplasma 114 (1983), S. 85-92 
    Details
    ISSN: 1615-6102
    Keywords: Chloroplasts ; Iron stress ; Sugar beet ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When grown in iron-free media, the youngest leaves of healthy green sugar beet plants became completely yellow after 6 to 8 days. This chlorosis was quickly reversed by resupplying iron. A study of the ultrastructure of the iron -stressed leaves revealed apparently normal subcellular organization except for the plastids which were small and undeveloped, contained a rudimentary, disorganized grana-fretwork and clusters of vesicles in the periphery. Twelve to 16 hours after resupply of iron, aggregates of phytoferritin were observed in the stroma, and the granal fretwork underwent further development. There was an increased orientation of the membranes along the long axis of the plastids and an increase in the length of the individual grana stacks. By 48 hours, leaf chlorophyll content was about 40% of the control. At the ultrastructural level, parallel alignment of membrane orientation was complete and the grana stacks began to increase in the number of thylakoids per stack.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279871
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  • 92
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    Electronic Resource
    Nucleolus-associated bodies (karyosomes) in dividing and differentiating plant cells (1983)
    Springer
    Protoplasma 115 (1983), S. 1-10 
    Details
    ISSN: 1615-6102
    Keywords: Brassica napus ; Nucleolus ; Pisum sativum ; Ultrastructure ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The karyosome is a spherical body up to 1 μm in diameter that lies on the nucleolus of certain plant species, particularly those with a relatively low nuclear DNA content and an areticulate nuclear structure. It can be seen in the light microscope after impregnation with silver; in the electron microscope its structure consists of fibrillo-granular material. Nucleoli of cells in root apices may bear 0, 1, or 2 karyosomes. The frequency with which these numbers of karyosomes are observed depends on the location of the cells within the apex. In roots ofPisum sativum andZea mays the nucleoli of both slowly-dividing and young differentiating cells bear karyosomes more frequently than the nucleoli of rapidly-dividing cells. The karyosome seems to adopt a preferred location on the nucleolus, lying most frequently on the nucleolar surfaces directed towards the apex or base of the root. The origin and functional significance of the karyosome are discussed. Morphological evidence suggests that it may be material that formerly was part of a fibrillar centre.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01293574
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  • 93
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    Electronic Resource
    Stomatal pore and cuticle formation inFunaria (1983)
    Springer
    Protoplasma 116 (1983), S. 1-13 
    Details
    ISSN: 1615-6102
    Keywords: Cuticle ; Peristomatal transpiration ; Stomata ; Ultrastructure ; Funaria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cuticle and pore development in the guard cells ofFunaria were investigated with the electron microscope. Pore cuticle formation is simultaneous with the creation of the pore itself. The morphology of the pore cuticle is unlike that of any cuticle described in the literature. It has many lamellae which are penetrated by electron dense fibrils. Three different cuticular morphologies exist from the pore to the subsidiary cell walls. The cuticles on the pore and outer walls contain fibrils that sometimes reach to the surface. The subsidiary cell cuticle lacks fibrils altogether. It is hypothesized that (1) cuticularization of the middle lamella contributes to ventral wall separation and (2) differences in extent of cuticular fibrils are related to greater water loss from stomata than from subsidiary cells (peristomatal transpiration).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01294225
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  • 94
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    Electronic Resource
    Microtubule organization and morphogenesis in young spores of the mossTetraphis pellucida Hedw (1983)
    Springer
    Protoplasma 116 (1983), S. 115-124 
    Details
    ISSN: 1615-6102
    Keywords: Microtubules ; Moss ; MTOC ; Sporogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Microtubule systems appear sequentially at the distal and proximal poles of tetrad members during mid-sporogenesis in the mossTetraphis pellucida Hedw. The distal microtubule system emanates from a microtubule organizing center (MTOC) located between the single plastid and the nucleus. The distal MTOC and associated microtubules, which appear immediately after cytokinesis, are ephemeral and do not appear to be associated with the deposition of exine occuring at the same time. The proximal microtubule system, which appears slightly later than the distal system, is a more stable component of mid-sporogenesis. The proximal MTOC is an irregularly lobed, patelliform aggregation of electron-dense granules located beneath the plasma membrane at the proximal spore pole. Several bundles of microtubules radiate from the proximal MTOC and traverse the cell, enclosing the nucleus in an cone of microtubules. The proximal microtubule system is thought to function in aperture development and organelle migration. The relatively large nucleus migrates a short distance in the small spore early in the tetrad stage and maintains its acentric position at the proximal pole throughout later stages of sporogenesis. The plastid migrates later in the tetrad stage from its meiotic position parallel to the distal surface to a position perpendicular to the distal surface with one tip in close proximity to the proximal MTOC. The proximal microtubule system reaches its maximum development by the end of the tetrad stage and all micrographic evidence of it is lost in the maturation stages of late sporogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279828
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  • 95
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    Electronic Resource
    Morphogenesis of coremia and rhizomorphs in the AscomyceteSphaerostilbe repens (1983)
    Springer
    Protoplasma 116 (1983), S. 99-114 
    Details
    ISSN: 1615-6102
    Keywords: Sphaerostilbe repens ; Ultrastructure ; Differentiation ; Coremia ; Rhizomorphs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The differentiating stages of coremia and rhizomorphs inSphaerostilbe repens were studied by transmission electron microscopy. Vegetative mycelium is characterized by highly cytoplasmic cells rich in ribosomes and mitochondria and with few vacuoles as well as endoplasmic reticulum. Cell walls are thin attaining a maximum thickness of 0.10 μm. During the aggregating phase a prosenchymatous mass of randomly oriented cells is produced by localized elongation and branching of the filaments. The hyphae in this region have the appearance of actively metabolising cells. In the course of the differentiating phase, numerous hyphae of the median zone of the aggregate grow upward and downward to give rise to coremium and rhizomorph primordia respectively. The individual hyphal tips lay parallel to each other and cells of the growing apices retain their meristematic characteristics. At the periphery of the aggregate and to a lesser extent in the subapical rhizomorphic zone, cells reduce their cytoplasmic density as a consequence of a decrease in the number of ribosomes. These cells also increase in size and become isodiametric and vacuolated. During cellular differentiation walls increase steadily in thickness and at the elongating phase they reach 0.30 μm in the rhizomorphic cortex. Mucilaginous material is progressively deposited around hyphae and in the most differentiated zones, coalesce to fill interhyphal spaces. This extracellular matrix seems to play a role in maintaining cohesiveness of the aggregated organs. The tissue in the process of differentiation is scattered with cells highly enriched in mitochondria and with cells virtually undifferentiated. Accumulation of microfilaments takes place in the differentiating zone localized behind the immersed meristematic apex. These structures might be involved in wall synthesis. Glycogen rosettes accumulate in the vegetative mycelium surrounding the aggregating centers, suggesting the possibility of supplying energy during the differentiating processes. The vacuolar system, represented by autophagic vacuoles which are present until the differentiation phase, presumably may also participate in the biochemical changes that occur during aggregation. Coremial cells are characterized by an increase in wall thickness, a highly sinuous plasma-membrane as well as large amounts of mucilaginous compounds accumulated between hyphae, but in all other respects they resemble the cells of actively growing vegetative hyphae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279827
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  • 96
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    Electronic Resource
    Ultrastructure of aerial stalk formation by the ciliated protozoanSorogena stoianovitchae (1983)
    Springer
    Protoplasma 116 (1983), S. 125-135 
    Details
    ISSN: 1615-6102
    Keywords: Ciliated protozoan ; Sorogenesis ; Extracellular matrix ; Secretion ; Extrusive organelles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Sorogena stoianovitchae Bradbury andOlive is an unusual kinetophragminophoran ciliate characterized by the aggregation of individual trophic cells to form a multicellular sorogen that rises aerially from the medium surface to produce a sorocarp. A light and electron microscope study of sorogenesis revealed how the sorogenic cells produce the stalk. The feeding ciliates contain numerous subpellicular expansions of rough endoplasmic reticulum cisternae that are only one element of the secretory system necessary for stalk formation. Upon aggregation, the stalk secretory system develops further, initially with the proliferation of the subpellicular expansions. Then, during later aggregation and early sorogenesis, other secretory elements appear: stalk material vesicles, dense granule vesicles, and electron lucent vacuoles. These are all derived from the rough endoplasmic reticulum. Only the subpellicular expansions and stalk material vesicles appear to add to the stalk matrix. The dense granule vesicles could be precursors of the stalk material vesicles; the electron lucent vacuoles, which can be demonstrated to contain fibrillar material, are perhaps by-products of the secretory process. Sorogenesis inSorogena occurs by a mechanism unique among the stalk-producing protists that have been studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279829
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  • 97
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    Electronic Resource
    Stalk function during sorogenesis by the ciliated protozoanSorogena stoianovitchae (1983)
    Springer
    Protoplasma 116 (1983), S. 136-144 
    Details
    ISSN: 1615-6102
    Keywords: Stalk ; Ciliated protozoan ; Sorogenesis ; Extracellularmatrix ; Ultrastructure ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The sorogenic cells of the haptorid ciliateSorogena stoianovitchae Bradbury andOlive secrete a hydrated, fibrillar matrix that becomes organized to form a stalk. This light and electron microscope study examines the role of the secreted stalk matrix in the development of the sorocarp. The stalk material is secreted as a compact clump or clumps of material that expands as it hydrates. The expanded stalk material is initially viscous, but soon, through dehydration or cross-linking, solidifies to form a sheath. The sheath is the outside layer of the stalk, provides structural support, and controls the expansion of the newly secreted stalk material. The sorogenic cells continue to secrete stalk material that expands once it is outside of the cell. The resulting expansion force is directed upward by the sheath, thereby moving the cells further above the surface. The continued dehydration of the sheath material provides an inwardly directed force that also contributes to the upward movement of the sorogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279830
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  • 98
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    Electronic Resource
    Ultrastructural demonstration of loss and recovery of cytochrome oxidase activity during and after heat induction of microcycle conidiation inNeurospora crassa (1983)
    Springer
    Protoplasma 116 (1983), S. 149-154 
    Details
    ISSN: 1615-6102
    Keywords: Cytochrome oxidase ; Cytochemistry ; Ultrastructure ; Neurospora ; Heat treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cytochrome oxidase (EC 1.9.3.1) activity of conidia of wild-typeNeurospora crassa was detected cytochemically at the ultrastructural level by 3,′-diaminobenzidine (DAB) reaction during heat treatment at 46 °C and after shift down to 25 °C. At 46 °C the decrease in the enzyme activity was shown to be time-dependent (0–10 hours) in the progressively overswelling conidia. Gradual recovery of the DAB reaction occurred in mitochondria of conidia outgrowing conidiogenous germ tubes (microcycle conidiation) when shifted down to 25 °C. Inactivation of cytochrome oxidase was efficiently prevented during heat treatment in the presence of Tween 20. Such conidia no longer overswelled but still required shift down to 25 °C to produce germ tubes with delayed conidiogenous ability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279832
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  • 99
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    Electronic Resource
    The effect of UV-B and UV-C radiation on sugar beet leaves (1983)
    Springer
    Protoplasma 117 (1983), S. 7-16 
    Details
    ISSN: 1615-6102
    Keywords: Beta vulgaris ; Chloroplast ; Ultrastructure ; Ultraviolet radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of UV-C (254 nm) and UV-B (290–320 nm) radiation on leaves ofBeta vulgaris L. at the ultrastructural level was investigated. Although the damage caused by UV-C radiation was more striking than that resulting from UV-B radiation, several structural changes were seen in the UV-B treated material. Generally the effects of UV-B and UV-C radiation were different, suggesting different mechanisms of action, discernible even at the ultrastructural level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281779
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  • 100
    Electronic Resource
    Electronic Resource
    The ultrastructure of the formation and development of the amoeboid tapetum inArum italicum miller (1983)
    Springer
    Protoplasma 117 (1983), S. 116-129 
    Details
    ISSN: 1615-6102
    Keywords: Pollen ; Amoeboid tapetum ; Arum italicum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A tapetum is found around all higher plant meiocytes and is thought to nourish them. It may, in turn, be influenced by their development. The mature tapetal membrane in amoeboid (or periplasmodial) tapeta, of whichArum italicum is an example, fits closely around the developing meiocyte. This description of tapetal ultrastructure starts from the meiotic prophase when the tapetum is still cellular and comprises two rows of cells on the inside of the tetrasporangiate anther. The radial walls of the still cellular tapetum start to dissolve during leptotene of the first meiosis. The lysis begins in the middle lamella in those areas penetrated by the most plasmodesmata. The walls in contact with the meiocytes on the other hand do not disappear until after the first meiosis. At telophase the now fused cytoplasmic tapetal mass begins to extend its joint plasmamembrane, amoeboid fashion, into the loculus. A cluster of microtubules can be seen at the apex of this intrusion apparently initiating or maintaining the shape of the invading plasmamembrane front. The tapetum now adheres closely to the microspores. The tapetal zone closest to the spores has a prominent population of microtubules and just a little ER, whereas the outer zone away from the spores contains all the other organelles. The inner zone, in a squash preparation, is not readily separated from the spores. The microtubules, at the middle microspore stage, are no longer to be seen in a circle around the microspores, but spread out with some lying orthogonal to the now-forming exine surface. In places the tapetal plasmamembrane begins to retract from the exine leaving roughly cone-shaped zones (spines) which become filled with fibrillar material. This material begins to be deposited on the exine surface. These “spines” are both PAS. and Coomassie-blue positive and susceptible to acetolysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01288350
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