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  • Atomic, Molecular and Optical Physics  (6,266)
  • Nuclear reactions  (4,460)
  • Ultrastructure
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Keywords
  • 101
    Electronic Resource
    Electronic Resource
    Ultrastructural study of capillary angiogenesis in rat fetal hearts: Role of fibroblasts and myocardial clefts (1998)
    Springer
    Medical molecular morphology 31 (1998), S. 185-192 
    Details
    ISSN: 1860-1499
    Keywords: Rat fetal heart ; Capillary angiogenesis M ; Myocardial cleft ; Fibroblast ; Desmosome-like structure ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To determine the course of capillary angiogenesis in the rat fetal heart, transmission electron microscopy was used to examine the development of both capillaries and cardiomyocytes. In the 15-day-old embryo, the coronary vessels had spread into the superficial space. In the 16-day-old embryo, the coronary vessels began to enter the myocardium. In the 17-day-old embryo, the terminal vascular bed had developed and a marked increase in the population of myocytes was evident. In capillaries entering the myocardium, the outgrowth of endothelial cells into the myocardial cleft was evident. These clefts were formed by intercalated disk and desmosome-like structures. The fibroblasts were always found close to the capillaries or in contact with endothelial cells during the fetal stage to the first neonatal week. In the interstition period, the fibroblasts were not found close to the capillaries. These results are discussed in relation to the role of myocardial clefts and the role of fibroblasts in fetal capillary angiogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545700
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  • 102
    Electronic Resource
    Electronic Resource
    Malignant myoepithelioma of the oral palate: Ultrastructural and immunohistochemical studies and survey of the literature (1998)
    Springer
    Medical molecular morphology 31 (1998), S. 200-206 
    Details
    ISSN: 1860-1499
    Keywords: Malignant myoepithelioma ; Oral palate ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Malignant myoepithelioma arising in the palatal gland is extremely rare. The present study demonstrated ultrastructural and immunohistochemical features of malignant myoepithelioma transformed from long-standing benign myoepithelioma occurring in the palatal gland. Microscopically, the tumor mass was composed of plasmacytoid cells and epitheloid cells. The malignant feature was seen only at the area adjacent to the bone. Immunohistochemically, most of the cells were S-100 positive, whereas vimentin and keratin were only partially positive. Glial fibrillary acid protein (GFAP) was positive at the peripheral cells of the solid nests and epitheloid cells with myxoid stroma. Ultrastructurally, filament-rich cells, tonofilament-rich cells, and filament-poor cells were observed. At the area adjacent to the bone, the cells implying malignancy were filament-poor cells in which the luminal structures could be detected. From these findings, a scarcity of filaments in myoepitheliomatous components may imply a malignancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545702
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  • 103
    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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  • 104
    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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  • 105
    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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  • 106
    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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  • 107
    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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  • 108
    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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  • 109
    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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  • 110
    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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  • 111
    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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  • 112
    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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  • 113
    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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  • 114
    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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  • 115
    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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  • 116
    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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  • 117
    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.
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    URL: http://dx.doi.org/10.1007/s004290050048
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    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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    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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    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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    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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    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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    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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    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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    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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    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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    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.
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    URL: http://dx.doi.org/10.1007/s004410050905
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    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.
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    URL: http://dx.doi.org/10.1007/s004410050968
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    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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    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.
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    URL: http://dx.doi.org/10.1007/s004410050909
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    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.
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    URL: http://dx.doi.org/10.1007/s004410050817
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    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.
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    URL: http://dx.doi.org/10.1007/BF01279886
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    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.
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    URL: http://dx.doi.org/10.1007/BF01280732
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    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.
    Type of Medium: Electronic Resource
    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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  • 137
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    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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  • 138
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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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  • 139
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    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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  • 140
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    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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    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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    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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    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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  • 144
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    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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    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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  • 146
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    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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  • 147
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    Noninteger principal quantum numbers increase the efficiency of Slater-type basis sets (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 1-11 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Roothaan-Hartree-Fock (RHF) calculations are carried out for the ground states of the atoms from helium to xenon using a minimal basis set of Slater-type functions whose principal quantum numbers are allowed to take variationally optimal noninteger values. The resulting energies are substantially superior to those obtained previously under the usual restriction that principal quantum numbers be positive integers. The energy lowering relative to the single-zeta wave functions of Clementi and co-workers ranges from 0.0066 Eh in He to 11.2 Eh in Xe. Our results are superior to those obtained by Höjer using a minimal basis set of unconventional binomially screened basis functions. Noninteger principal quantum numbers benefit d-orbitals the most; physically realistic negative d-orbital energies are obtained in all cases including those transition-metal atoms for which a conventional single-zeta STF basis leads to positive d-orbital energies. © 1997 John Wiley & Sons, Inc.
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    Ab initio study on the reaction of Sc+ + CH4 → Sc+(SINGLE BOND)CH2 + H2 (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 23-27 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An ab initio study on the reaction of the ground state (3D) and the excited state (1D) of Sc+ with methane was performed. Reaction channels on the singlet and triplet potential surface (PES) and the reaction mechanism are examined and discussed. Three regions of the potential surface was studied: the molecular complex, the C(SINGLE BOND)H insertion products, and the transition states for the reaction. Comparisons between singlet and triplet PESs show that the excited state (1D) of Sc+ has more reactivity with methane than does the ground state (3D) due to the spin quantum number conservation with the more stable insertion intermediate. © 1997 John Wiley & Sons, Inc.
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    Influence of hybridization displacement charge on the description of electrostatic potentials of molecules with multiple electrophilic sites (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 67-76 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The importance of the hybridization displacement charge (HDC) in describing molecular electrostatic potential (MEP) maps was demonstrated by studying six molecules; pyrazine N-oxide, para-nitropyridine, 5-nitropyrimidine, 3-nitropyridazine, N2, and N2O. It is shown that continuously distributed HDC-corrected Löwdin charges reproduce the MEP features of these molecules, most of which have competing electrophilic sites, in agreement with ab initio results. Further, it is found that for homonuclear diatomic molecules MEP minima can be located properly using HDC-corrected Löwdin (or HDC-corrected Mulliken) continuously distributed charges, but these features cannot be obtained using the conventional Löwdin (or Mulliken) charges. It was shown that the order of molecular electric field (MEF) values near the different electrophilic sites becomes changed when one moves away from the molecules. Thus, pyridine-type nitrogen atoms are the preferred binding sites close to the molecules, while at large distances, effects of oxygen atoms of the NO groups become dominant. © 1997 John Wiley & Sons, Inc.
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    Crystalline and local vibrations of paired bases in poly(dG)-poly(dC) interacting with the h-b-1 hydrogen bond (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 115-124 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some types of atomic vibrations in a chain of the DNA type constructed of G-C pairs were studied. These are the atomic vibrations of the lateral groups of guanine and N(3)H(1)H(2) of cytosine connected by the hydrogen bond h-b-1 and the vibrations of the centers of masses of bases in the direction parallel to bonds h-b-i, i = 1-3. The vibrations mix partially due to the dependence of the energy of the bond h-b-1 on its length and split into two bands because of the interaction between neighboring base pairs. It was shown that the excitation of the bond h-b-1 results in the splitting off of the two local vibrations and in a small deformation of the chain in the vicinity of the pair with the localized hydrogen bond. The law of the dispersion of band vibrations, values of the split-off frequencies, and degree of poly(dG)-poly(dC) chain deformation were determined. © 1997 John Wiley & Sons, Inc.
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    Evaluation of screened nuclear attraction and electron repulsion molecular integrals over Gaussian basis functions (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 273-278 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Analytical solutions to the Yukawa-like screened Coulomb nuclear attraction and electron repulsion molecular basic integrals, as well as to the basic integrals required to compute the virial coefficient, over Gaussian basis functions, are derived and cast into a practical closed form, suitable to interface with modern codes for the calculation of molecular electronic structure. © 1997 John Wiley & Sons, Inc.
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    Photoelectron spectra of molecules. II. Carboxylic acids and their esters (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 303-314 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: He I photoelectron (PE) spectra of four carboxylic acids and five esters are measured. Semiempirical and ab initio quantum chemical calculations are used for the interpretation of the spectra. The complex approach which uses empirically established relationships (the dependence of valence electron ionization energies on proton affinities in the gas phase, on the core level ionization energies, and on the structure) was developed. © 1997 John Wiley & Sons, Inc.
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    Molecular orbital analysis of chemical carcinogens (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 323-328 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simple molecular orbital calculations are employed in searching electronic parameters which may characterize the chemical carcinogens. Using frontier orbitals, the carcinogen-DNA bond formation is described as an electron transfer from the highest occupied molecular orbital (HOMO) of DNA to the lowest unoccupied molecular orbital (LUMO) of the carcinogen. Analysis of the DNA bases units shows that the electron donation occurs preferentially at the guanine site. The calculated low LUMO energy of several carcinogens indicate correctly the electrophilic character of these compounds. The difference between the carcinogen and the ultimate carcinogen is analyzed. Epoxides, free radicals, alkylating agents, and other metabolite forms are studied. A reasonable correlation is found between the LUMO energy and the carcinogenic function. © 1997 John Wiley & Sons, Inc.
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    Generalized relativistic effective core potential: Gaussian expansions of potentials and pseudospinors for atoms Hg through Rn (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 1107-1122 
    Details
    ISSN: 0020-7608
    Keywords: relativistic pseudopotentials ; heavy atoms ; method of molecular calculation ; electronic structure ; Gaussian approximation ; Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Gaussian expansions of the generalized relativistic effective core potential (GRECP) components are reported for elements Hg through Rn. The accuracy of the analytical GRECPs is estimated by calculations of atomic transition energies with the numerical one-configurational wave functions in comparison with Dirac-Fock calculations. The results of the corresponding calculations with the RECPs of other groups are also given. An “averaged error” in the reproduction of the transition energies without the change of the occupation number of the 5d-shell is an order of magnitude smaller than that for the RECPs of other groups. As is demonstrated for the transitions with the change of the occupation number of the 5d-shell in mercury, the largest absolute error of the GRECP is only 1.5-2 times smaller than that of the energy-adjusted pseudopotential (PP) or the RECP of Ross et al. with the same space of explicitly treated electrons. However, the dispersion of these errors is 19⋅10-4 au for the energy-adjusted PP, 35⋅10-4 au for the RECP of Ross et al. and only 4⋅10-4 au for the GRECP. One-configurational spin-averaged calculations of the molecular properties for HgH and HgH+ are carried out and compared with the corresponding results of Häussermann et al.   © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 1107-1122, 1997
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    Molecular dynamics simulation of the free surface of liquid formamide (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 1123-1131 
    Details
    ISSN: 0020-7608
    Keywords: MD simulations ; liquid surface ; formamide ; molecular orientation ; molecular surface density ; Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular dynamics simulations of liquid formamide(HCONH2) were carried out using the GROMOS software. The formamide molecule is represented by all of its atoms with all internal degrees of freedom. In contrast to other simulations dealing with bulk properties, this study focuses on the interface liquid-vacuum for the first time. We show that the molecular plane is tilted out of the surface, exposing the HCO group to the vacuum.   © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 1123-1131, 1997
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    Theoretical study on Pd dimer and trimer interaction with the hydrogen molecule (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 29-45 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The H2 interaction with the Pd dimer and trimer were studied using multiconfigurational self-consistent field (MC-SCF) calculations with the relativistic effective core potential (RECP); the correlation energy correction was included in the extended multireference configuration interaction (MRCI), variational and perturbative to second order. Here, we considered the Pd2 first six states: 3Σ+u, 1Σ+g, 3Πg, 3Δxy, 1Σ+u, and 3Σ+g. For them, the four geometrical approaches included were the side-on H2 toward Pd2, for the hydrogen molecule in and out the Pd dimer plane; the perpendicular end-on H2 toward Pd2; and the perpendicular end-on Pd2 to H2. The Pd2 ground state is 3Σ+u, which only captures H2 in the C2v end-on approach, softly relaxing the H(SINGLE BOND)H bond. The closed-shell 1Σ+g captures the H2 molecule in all the approaches considered: The side-on approach of this state presents deep wells and relaxes the H(SINGLE BOND)H bond, and the end-on approach captures H2 with a relatively longer H(SINGLE BOND)H distance and also a deep well. The 3Πg state was the only one which did not capture H2. For the triangular Pd3 clusters, H2 was approached in the C2v symmetry in and out of the Pd3 plane. In the triangular case, H2 was absorbed in both spin states, with deep wells and relaxing the H(SINGLE BOND)H distance. The linear Pd3 singlet and triplet states capture outside of the Pd3 and break the H(SINGLE BOND)H bond. © 1997 John Wiley & Sons, Inc.
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    Total and partial decay widths in vibrational predissociation of the HeI2 van der Waals complex for lower initial vibrational excitations (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 89-96 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We presented a calculation of the total and partial decay widths of vibrational predissociation (VP) of the HeI2 molecule for low initial vibrational excitations from the lowest van der Waals (vdW) state with total angular momentum J = 0. A time-dependent golden rule wave-packet method was employed in our numerical calculations for the decay widths. The computed total decay widths, lifetimes, and rates of VP are in fairly good agreement with those extrapolated from the experimental data available. Predicted total decay widths as a function of initial vibrational levels exhibit a highly nonlinear behavior. These results demonstrate that a quantum mechanical decay mode for low vibrational excitation remains as well. The total propagation time needed in the time-dependent golden rule wave-packet calculations is much shorter than is the lifetime of the predissociation of HeI2. It is shown that the final-state interaction between the fragments is important for determining the final rotational-state distribution (partial decay width). We find that the major peak position in the final rotational-state distribution shifts to lower rotational energy levels with increase of the initial vibrational quantum number, which is evidently different from that for higher vibrational levels. This fact can be clearly explained by the dependence of the amount of kinetic energy released to the product degrees of freedom on the initial vibrational state. © 1997 John Wiley & Sons, Inc.
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    A very accurate grid method for the solution of Schrödinger equations: The helium ground state (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 1065-1078 
    Details
    ISSN: 0020-7608
    Keywords: very precise eigenvalues ; very accurate grid method ; general solution for Schrödinger equations ; rapidly convergent treatment for helium eigenvalues ; superconvergence ; optimization of grids ; treatment of continuum ; Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An extension to the theory of Schrödinger equations has been made which enables the derivation of eigenvalues from a consideration of a very small part of geometric space. The concomitant unwanted continuum effects have been removed. The theory enables very convergent or “superconvergent” calculations. In the case of the helium ground state, E=-2.90372437703411987 Eh was obtained from 251 terms. The result is comparable to that from the largest variation calculations so far carried out reinforced by extrapolation techniques. The theory is extensible to atoms and molecules irrespectively of the number of electrons or nuclear centers. In these cases, the advantage of “superconvergent” calculations will be more pronounced than in the case of helium.   © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 1065-1078, 1997
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    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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    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02478883
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    Resonances and antibound states in a Morse potential (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 239-244 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We calculate the resonant and antibound state energies for a Morse potential with a centrifugal barrier using Siegert boundary conditions. Starting with a complex wave number k (purely imaginary for bound and antibound states), we integrate numerically from the origin up to a matching point using Numerov's method. The inward integration is performed using the corresponding (first-order) Riccati equation. The complex eigenvalues are found by matching the two logarithmic derivatives. We find narrow shape resonances within the well, above the dissociation limit, and broad resonances above the centrifugal barrier. Antibound states are found even with J = 0. © 1997 John Wiley & Sons, Inc.
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    On the dynamics of a linear and a nonlinear quantum oscillator with randomly changing harmonic frequency (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 265-272 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Numerical experiments with a nonlinear (λχ4) oscillator which has its harmonic frequency changing randomly with time reveal certain interesting features of its dynamics of quantum evolution. When λ = 0, the level populations are seen to oscillate. But, as the nonlinear coupling is switched on (λ 〉 0), a threshold is reached at λ = λc when the evolution is seen to be characterized by an abrupt transition dominantly to the highest available state of the unperturbed (initial) oscillator. It is shown that this transition probability is maximized at a particular value of λ. The time threshold for this transition decreases with increasing nonlinear coupling strength. The numerically obtained structures of the underlying quantum-phase spaces of the linear and nonlinear random oscillators are examined. Possible use of these results in a problem of chemical origin is explored. © 1997 John Wiley & Sons, Inc.
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    Electronic structure of testosterone: A semiempirical and ab initio assessment (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 279-289 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Testosterone (17β-hydroxy-4-androsten-3-one) was studied by the semiempirical AM1 and PM3 and ab initio STO-3G*, 3-21G*, and 6-31G* methods. The goals were to compare those methods and to know the electronic structure of the hormone. Full geometry optimization was performed, and two crystal conformers (T1 and T2), and experimental dipole moment in solution were used for comparison. One conformer with a dipole moment similar to the solvated conditions was generated. Total energy, entalphies, dipole moments, charges, electrostatic potentials, and highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbital (LUMO) were calculated. Root-mean-square (RMS) index of the theoretical molecules against T1 and T2 showed best results with the 3-21G* and 6-31G* methods, while AM1 gave better energies than PM3. Dipole moments were directed toward the OH group and the botton face of the A ring. The frontier orbitals were located along the C4-C5 π bond, particularly the LUMO was split between C4 and C5, predicting the action of enzymes at C5 yielding to 5α and 5β-reduced androgens. Electrostatic potentials might be also of biological importance since they are coincidental with the dipole-moment orientation. Finally, it is interesting that the solvatedlike conformer, its properties, and the OH group laid between the same group of T1 and T2 and with a total energy between the crystals and the gas phase or in vacuo conditions. This results might also explain the biology of testosterone and use them to model the hormone-receptor interaction. © 1997 John Wiley & Sons, Inc.
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    A study of methanetetraol dehydration to carbonic acid (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 315-322 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two alternative dehydration reactions C(OH)4 → (HO)2CO + H2O and C(OH)4 + H2O → (HO)2CO + 2H2O are studied by ab initio Becke3LYP/6-311 + G** and MP2/6-31G** methods. Calculated energy and geometry characteristics of intermediates and transition states predict a catalytic effect of one water molecule and the exothermism of the transformations. Relevant HF/6-311 + G**, HF/6-31G**, HF/6-31G, and HF/3-21G calculations were performed for comparison. © 1997 John Wiley & Sons, Inc.
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    Hydrogen-bonding effects, electrostatic potential, and the antitumor activity of flavone acetic acid and related compounds. III. Ab initio studies on the conformation space (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 97-113 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Restricted geometry optimizations at the ab initio SCF level with the 3-21G basis set were employed to investigate the conformation space of flavone acetic acid (FAA) and its related compounds. All the conformations are produced from a conformation which is, according to our previous work, probably the active conformation in terms of antitumor activity shown by these compounds. Detailed studies on FAA were carried out while only brief discussions are made on the analogs. The main results obtained are that (1) FAA is a very flexible molecule, e.g., with the energy barrier up to about 3 kcal mol-1 from the reference conformation, the important torsional angle τ1 can change from 27.0° to 117.0°, τ2 from -168.0° to 2.0°, and τ3 from -50.0° to 30.0°; (2) the hydrogen-bonding effect plays an important role in determining lower-energy conformations; (3) among all the FAA conformations considered, some are active and some are inactive; (4) it seems that the analogs will have similar behavior to FAA when the torsional angle τ3 is restricted to the values which are around the equilibrium values; and (5) the hypothesis put forward previously has been further developed in this work. Now, we postulate that efficient charge transfers will lower the energy and that proper charge transfers will activate the molecule. There are mainly two different types of charge transfer corresponding to two different types of conformation, which are specified in this article. © 1997 John Wiley & Sons, Inc.
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    Modeling properties of the HF dimer in argon clusters (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 55-65 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We compare geometry configurations, vibrational properties, and electronic structures of (HF)2 in a free state and inside argon atom shells Arn. For the first stage, molecular dynamics calculations for the (HF)2 · Ar62 heterocluster are performed with the help of model potentials HF(SINGLE BOND)HF, Ar(SINGLE BOND)Ar, and Ar(SINGLE BOND)HF. Then, ab initio quantum chemistry analysis is carried out for the smaller systems (HF)2 · Ar15 and (HF)2 · Ar6 when keeping the argon atoms closest to the trapped dimer. We conclude that the hydrogen-bonded complex (HF)2 gains some extra stability inside the argon shells, originating primarily from a decrease of intermolecular distance RFF. Electronic structure calculations are in accord with the changes in dynamical properties, namely, a noticeable increase in the vibrational frequency assigned to the F(SINGLE BOND)F stretching mode (+25 cm-1) and decrease in rms deviations for the corresponding coordinate δFF. In addition to these changes, the argon atoms of the nearest solvent shell donate a small fraction of electron charge which is spent for an increase of population of the antibonding orbital σ*Hf(SINGLE BOND)Ff of the free monomer unit and shift orbital energies primarily of the lone-pair fluorine species. These shifts are greater than the changes due to geometry alterations and the possible inaccuracies of the calculation scheme. © 1997 John Wiley & Sons, Inc.
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    Numerical solution for the ground-state energy of the anisotropic Heisenberg model (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 13-21 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analysis of the anisotropic Heisenberg model is carried out by solving the Bethe ansatz solution of the model numerically as a function of the anisotropy parameter for finite N. A brief introduction to the limit of the infinite chain is presented. The energy for a few special limiting cases of the anisotropy parameter in the Hamiltonian are worked out. Numerical results for finite cycles as well as for the infinite chain are given. Comparison can then be made with the case of finite increasing N. © 1997 John Wiley & Sons, Inc.
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    Evaluation of a characteristic atomic radius by an ab initio method (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 47-53 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The MELD program is employed to evaluate the Slater average potential v(r) felt by an electron at the point r within an atom. The characteristic radius R of the atom is then defined by the classical turning point equation v(R) = -I, where I denotes the first ionization potential of the atom. The atomic radii defined in this way have a close correlation with the van der Waals atomic radii. © 1997 John Wiley & Sons, Inc.
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    Accurate nonrelativistic energies for 2Pe states of the Li isoelectronic series (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 77-88 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly accurate upper bounds for several 2Pe states of the Li isoelectronic series obtained by extensive Hylleraas-Cl calculations are given. The best value for the 22Pe state (1s2p2) of Li is -5.21373920 au. The evaluation of the occurring integrals is given explicitly. Additionally, we present some expectation values and isotope energies of the Li isoelectronic series. © 1997 John Wiley & Sons, Inc.
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    Efficient evaluation of the algebrants of VB wave functions using the successive expansion method. I. Spin S = 0, ½ (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 245-259 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An efficient expansion method for the evaluation of VB matrix elements is introduced. The overlaps of VB wave functions of N electrons can be treated as algebrants, i.e., generalized determinants, of N × N matrices. An algebrant can be expanded with subalgebrants of lower orders in a successive way. By choosing Rumer spin bases and appropriately arranging the expansion, it is found that the number of unique subalgebrants involved in the expansion increases in a quite moderate way with N. In contrast to the traditional symmetric group approach, which explicitly utilizes all N! representation matrices, the new strategy incorporates the group theoretical factors in a simple way in the successive expansion. As only the unique subalgebrants are further expanded, the computational effort required by the new strategy scales in a very acceptable manner with the increasing number of electrons. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 62: 245-259, 1997
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    Characters of two-row representations of the symmetric group (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 261-264 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Characters of irreducible representations (irreps) of the symmetric group corresponding to the two-row Young diagrams, i.e., describing transformation properties of N-electron eigenfunctions of the total spin operators, have been expressed as explicit functions of the number of electrons N and of the total spin quantum number S. The formulas are useful in various areas of theory of many-electron systems, particularly in designing algorithms for evaluation of spectral density moments. © 1997 John Wiley & Sons, Inc.
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    Computation of bond dissociation energy for sulfides and disulfides with ab initio and density functional theory methods (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 291-296 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The geometries and S-H, S-S, and S-C bond dissociation energies for hydrogen sulfide, hydrogen disulfide, methanethiol, dimethyl disulfide, and dimethyl disulfide were calculated with both ab initio (ROHF and MP2), hybrid (BHandH, BHandHLYP, Becke3LYP and Becke3P86), and nonlocal (BLYP and BP86) density functional theory (DFT) methods. In all studies the 6-31 + G(d) basis set is used. The computed results are compared to the experimentally obtained values, targeting the selection of a suitable ab initio or DFT method for the study of these systems. © 1997 John Wiley & Sons, Inc.
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    Theoretical study on the pyrolysis mechanism and kinetics of β-hydroxyketones (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 62 (1997), S. 297-302 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism and kinetics for the decomposition of β-hydroxypropaldehyde, primary and secondary β-hydroxyketones, were studied by using ab initio RHF/6-31G and RHF/6-31G* methods. The activation barriers of these reactions were refined to be 39.57, 40.10, and 36.80 kcal mol-1 at the MP2/ /RHF/6-31G* level, respectively. The calculated results show that each decomposition is a concerted process with hydrogen transferring and bond breaking via a six-membered cyclic transition state. The thermal rate constants of the decomposition of primary and secondary β-hydroxyketones were obtained by calculating microcanonical probability fluxes through each transition state. It is theoretically confirmed that methyl substitution at the hydroxyl carbon of β-hydroxyketones causes a small enhancement in rates. The theoretical investigations of the mechanism and the rate constants are in agreement with the experimental results. © 1997 John Wiley & Sons, Inc.
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    Power series with rational coefficients for two-electron atom energies (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 1079-1089 
    Details
    ISSN: 0020-7608
    Keywords: large-order perturbation theory ; lie algebra ; three-body problem ; symbolic computations ; helium atom ; Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The method of o(4, 2) operator replacements is generalized. As a result, the series whose limiting values when the variable goes to  +∞ should correspond to the two-electron atom energies now have rational coefficients. This generalization allows one also to compute the series for the case of singlet S symmetry, a case which could not be considered in the previous original formulation of the method. Series with rational coefficients for the helium singlet and triplet S ground-state energy are calculated up to order 41 and 45, respectively. Moreover, symbolic computations also allow one to give the first few coefficients of these series for arbitrary values of the nuclear charge Z. Finally, a new method for analytic continuation to the limit  +∞ is presented for the energies of the helium singlet and triplet ground states.   © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 1079-1089, 1997
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    A study of bond-cleavage and bond-formation processes in some simple metathesis reactions (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 1099-1106 
    Details
    ISSN: 0020-7608
    Keywords: metathesis reactions ; bond order ; free valence ; minimum energy path ; nonsynchronization ; Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A few simple atom-transfer reactions (i.e., Ȧ+X-A→A-X+Ȧ) are studied by quantum mechanical ab initio methods. Emphasis is given to the detailed analysis of density matrices rather than to the energetics. Results reveal that during these reactions a small free valence always develops on the migrating atom at the transition state. The barriers in these reactions arise from the greater extent of bond cleavage in the reactant than that of bond formation in the transition state. Analysis of bond orders estimated from bond lengths using Pauling's relation also leads to the fact that the bond-cleavage process is more advanced than is the bond-formation process in these reactions.   © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 1099-1106, 1997
    Additional Material: 4 Ill.
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  • 176
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    Cytochemical staining and ultrastructural characteristics of peripheral blood leucocytes from the yellow rat snake (Elaphe obsoleta quadrivitatta) (1996)
    Springer
    Comparative clinical pathology 6 (1996), S. 86-91 
    Details
    ISSN: 1433-2981
    Keywords: Cytochemical staining ; Leucocytes ; Snake ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cytochemical staining and ultrastructural characteristics of peripheral blood leucocytes from the yellow rat snake are described. A panel of cytochemical stains, including demonstration of myeloperoxidase, acid phosphatase, naphthol AS-D chloracetate esterase, alpha-naphthol butyrate esterase and alkaline phosphatase activities; and periodic acid-Schiff and Sudan Black-B staining was performed. Snake heterophils lacked peroxidase, alkaline phosphatase and acid phosphatase activity. Azurophils stained positively for all stains except alkaline phosphatase activity. Lymphocytes showed positive acid phosphatase activity. Differentiation of thrombocytes from lymphocytes was very difficult even with cytochemical staining. Only a minor staining difference was observed with periodic acid-Schiff stain. Thrombocytes exhibited coarse, dark, purple stippling usually located in the polar area of the cytoplasm, whereas lymphocyte staining varied from none to very fine, pale pink granules dispersed throughout the cytoplasm. Ultrastructural characteristics were similar to those of mammalian leucocytes with the exception that the snake basophil granules have no crystalline matrix, and heterophil granules appeared as large, elongate, membrane bound structures of varying density with no distinct core or matrix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426047
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  • 177
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    Hochauflösende Rasterelektronenmikroskopie von isolierten äußeren Haarzellen (1996)
    Springer
    HNO 44 (1996), S. 630-633 
    Details
    ISSN: 1433-0458
    Keywords: Schlüsselwörter Innenohr ; Ultrastruktur ; Einzelzelle ; SEM ; Key words Inner ear ; Ultrastructure ; Isolated hair cells ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Isolated hair cell preparations have gained wide acceptance as a model for studying physiological and molecular properties of the sensory cells involved in the hearing process. Ultrastructural details, such as stereocilia links, lateral membrane substructure or synaptic links are of crucial importance for normal sensory transduction. For this reason, we developed a high-resolution scanning electron microscopy (SEM) procedure to study the surface of isolated hair cells. Cells were mechanically and/or enzymatically separated, isolated and immobilized on cover slips by alcian blue and fixed by 2% glutardialdehyde or 1% OsO4. After dehydration, preparations were critical point-dried and sputter-coated with gold-palladium (2–4 nm). Up to 5 nm resolution was achieved. Optimal fixation kept the cells in their typical cylindrical forms. Preservation of the stereocilia and the apical plates of the outer hair cells depended strongly on the fixation process. Tip- and side-links were observed only sporadically because of the aggressive preparation procedure. The lateral plasma membranes of the cell bodies showed regular granular structures of 5–7 nm diameter at maximal magnification. The granular structure of the cell membrane seemed to correspond to putataive transmembrane proteins believed to generate membrane-based motility. The remnants of the nerve endings and/or supporting cells usually covered the cell base. The preservation of the cells was better when enzymatic isolation was omitted. The technique used allowed for high resolution ultrastructural examination of isolated hair cells and, when combined with immunological labeling, may permit the identification of proteins at a molecular level.
    Notes: Zusammenfassung Isolierte Sensorzellen aus dem Innenohr stellen ein akzeptiertes Modell zur Untersuchung von elektrophysiologischen und molekularen Eigenschaften dieser Zellen dar. Um morphologische Substrukturen zu erfassen, haben wir ein rasterelektronenmikroskopisches (REM) Untersuchungsprotokol zur Darstellung der Oberfläche isolierter Haarzellen entwickelt. Die Zellen wurden mechanisch und/oder enzymatisch isoliert und auf mit Alcianblau (0,1–1%) beschichteten Glasplättchen immobilisiert. Es folgte eine chemische Fixation mit Glutardialdehyd und Osmiumtetroxyd. Nach einer Ethanoldehydratation und Trocknung nach der Kritischen-Punkt-Methode mit Hilfe von CO 2 wurden die Proben mit einer dünnen Schicht Gold-Paladium (2–4 nm) beschichtet. Die Untersuchung erfolgte am REM der Fa. Hitachi S-800. Bei optimaler Fixierung wurde die typische zylindrische Form der Zellen erhalten. Wegen der aggressiven Preparation gelang die Darstellung von Tip- und Side-links nur unregelmäßig. Die laterale Zellwand erschien bei maximaler Vergrößerung regelmäßig granuliert bei einer Korngröße von 5–7 nm. Bei der dargestellten Granulation handelt es sich um intramembranöse Partikel (IMP). Diese können Proteinen entsprechen, die durch ihre Fähigkeit zur spannungsabhängigen Konformationsänderung die Motilität der Haarzellen erklären lassen. An der basalen Region der Zelle war keine Granulation feststellbar. Dieser Bereich war mit Nervenendigungen bzw. Resten der Deiters-Zellen bedeckt. Diese Technik ermöglicht die REM-Untersuchung von isolierten Sensorzellen aus dem Innenohr.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001060050068
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  • 178
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    Electronic Resource
    Acute monocytic leukaemia (M5a) in a horse (1996)
    Springer
    Comparative clinical pathology 6 (1996), S. 111-114 
    Details
    ISSN: 1433-2981
    Keywords: Alpha naphthyl acetate esterase ; Cytochemistry ; Horse ; Monocyte ; Monocytic leukaemia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Acute monocytic leukaemia (M5a) was diagnosed in a 17-year-old Standardbred gelding with lethargy, intermittent pyrexia, oedema of the limbs, harsh lung sounds and submandibular lymphadeopathy. Haematological findings included moderately severe anaemia, thrombocytopenia and a leucocyte count within the reference interval, but characterised by neutropenia and numerous blast cells. Monocytic lineage of the cell population was suggested by examination of Wright-Leishman-stained blood and bone marrow smears. A panel of cytochemical stains disclosed diffuse cytoplasmic α-naphthyl-acetate esterase activity which could be markedly inhibited or abolished in all leukaemic cells by pretreatment with sodium fluoride. In ultrastructural preparations of buffy coat, neoplastic monoblasts had one to two nucleoli, dispersed chromatin, elongated mitochondria, scattered profiles of rough endoplasmic reticulum, bundles of microfilaments and pseudopodia. More differentiated monocytoid cells had infrequent lysosomal granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426052
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  • 179
    Electronic Resource
    Electronic Resource
    Effects of long-term open-air exposure to fluoride, nitrogen compounds and SO2 on visible symptoms, pollutant accumulation and ultrastructure of Scots pine and Norway spruce seedlings (1996)
    Springer
    Trees 10 (1996), S. 157-171 
    Details
    ISSN: 1432-2285
    Keywords: Conifer ; Fluoride ; Nitrogen ; Sulphur dioxide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effects of SO2, aqueous fluoride (NaF) and a solution of nitrogen compounds (NH4NO3) on the visible symptoms, pollutant accumulation and ultrastructure of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L.) Karst.] seedlings were studied in an open-air experiment lasting for 3 consecutive years. Visible injury symptoms were most pronounced in combination exposures and whenever F was applied. Visible symptoms correlated well with needle pollutant concentrations. Exposure to NaF increased needle F contents particularly when F was applied with SO2 or NH4NO3. This suggests that a reduction in N or SO2 emissions, in F polluted areas, could improve the condition of conifers via decreased accumulation of phytotoxic F in the needles. Norway spruce needles accumulated 2–10 times as much S and F as those of Scots pine. Microscopic observations showed various changes in the needle mesophyll cell ultrastructure. In both species, exposure to SO2 increased significantly the amount of cytoplasmic vacuoles, suggesting detoxification of excess sulphate or low pH. F treatments resulted in a significant enlargement of plastoglobuli in Scots pine and a darkening of plastoglobuli in Norway spruce. All exposures enhanced the accumulation of lipid bodies. An increased portion of translucent plastoglobuli was most pronounced in N treatments. Many of the ultrastructural changes and visible symptoms appeared only as number of years exposed increased, indicating that long-term experiments are needed. Both visible symptoms and ultrastructural changes pointed to the more pronounced sensitivity of Norway spruce compared to Scots pine. Ultrastructural results mostly supported earlier qualitative observations of F, N and SO2 effects on needle mesophyll cell ultrastructure. However, no reduction of thylakoids in SO2 containing exposure or curling of thylakoids in F exposure could be detected in the present study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02340767
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  • 180
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    Electronic Resource
    Ultrastructure of multinucleated giant cell apoptosis in foreign-body granuloma (1996)
    Springer
    Virchows Archiv 428 (1996), S. 165-176 
    Details
    ISSN: 1432-2307
    Keywords: Foreign-body giant cells ; Granulation tissue ; Apoptosis ; Ultrastructure ; p53 expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To elucidate the role of apoptosis in the disappearance of multinucleated giant cells from the granulation tissue in cases of foreign-body granuloma, we induced a foreign-body reaction by implanting a collagen sponge into the dorsum of the rat and observed apoptotic changes within the multinucleated giant cells using electron microscopy. Two types of multinucleated giant cells were identified presenting apoptotic characteristics morphologically. One was characterized by apoptosis of only one nucleus, followed by cytoplasmic changes, rupture of the plasma membrane and necrosis evoking an inflammatory reaction. The other showed typical apoptotic changes in the majority or in all of the nuclei, followed by phagocytosis of the apoptotic syncytia. The results of the present study suggest that apoptosis occurring within only one nucleus might be triggered by overexpression of the p53 protein, because DNA abnormalities are confined to this single nucleus. In contrast apoptosis occurring simultaneously in the majority or all of the nuclei is most probably due to cell death caused by senescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00200659
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  • 181
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    Electronic Resource
    Fine structural changes of muscle spindles in the gracile axonal dystrophy mutant mouse (1996)
    Springer
    Virchows Archiv 428 (1996), S. 289-296 
    Details
    ISSN: 1432-2307
    Keywords: Mutant mouse ; Axonal degeneration ; Dying back process ; Muscle spindles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fine structural changes of muscle spindles in the extensor digitorum longus of the gracile axonal dystrophy mutant mouse were studied from 20 to 120 postnatal days. Degenerative nerve endings in muscle spindles were first recognized at 20 postnatal days. The sensory nerve endings were usually swollen with decrease of cell organelles, and the cytoplasm was electron-lucent. At 50 postnatal days, atrophic nerve endings were frequently observed in the narrow spaces between the indented cell membrane of intrafusal muscle cells and the basement membrane. In addition to degenerative and atrophic changes, regenerative axons showing fine sprouts (with or without Schwann cell projections) appeared in the sensory nerve endings at this time. At 80 postnatal days, sensory nerve endings frequently showed dystrophic changes characterized by axonal dilatation with accumulations of neurofilaments, tubulovesicular structures, mitochondria and myelin-like figures. These findings suggest that axonal transport in the sensory nerve endings is impaired in this mutant mouse. Motor nerve endings were usually well preserved and normal structures even at 80 postnatal days. Intrafusal fibrosis, decrease in number of sensory nerve endings and atrophy of intrafusal muscle fibres were clearly recognized by 100 days of age.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00196703
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  • 182
    Electronic Resource
    Electronic Resource
    Immunocytochemical localization of Tamm-Horsfall protein in the kidneys of normal and nephrolithic rats (1996)
    Springer
    Urological research 24 (1996), S. 201-209 
    Details
    ISSN: 1434-0879
    Keywords: Calcium oxalate ; Hyperoxaluria ; Nephrolithiasis ; Tamm-Horsfall protein ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Studies using in vitro systems have indicated that Tamm-Horsfall protein (THP) can interact with calcium oxalate (CaOx) crystals during kidney stone formation. However, information regarding the nature of its participation in this process remains controversial and unclear. In order to better understand the putative interaction of THP and crystals in vivo, we compared the localization of THP in normal rats and in chronic and semi-acute rat models of nephrolithiasis. In these rats, CaOx crystal deposits were induced in the kidneys by administering ethylene glycol (EG) in drinking water. The formation of CaOx mono- and dihydrate aggregates in the urine was confirmed by scanning electron microscopy. Immunohistochemical localization, as well as protein A-gold labeling at the ultrastructural level, demonstrated that in addition to its normal distribution, THP specifically associated with the renal crystal deposits. The THP-containing, organic matrix-like material consisted of a fine, fibrillar meshwork surrounding individual crystals and their aggregates. In addition, THP also appeared in the papilla, where it is normally absent, concurrent with the appearance of crystal deposits in the kidneys. These observations indicate that in nephrolithic rats the normal localization of THP is altered. Such an alteration may indicate an important physiological event related to crystal aggregation and kidney stone formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00295893
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  • 183
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    Electronic Resource
    The microvascular system in ischemic cortical lesions (1996)
    Springer
    Acta neuropathologica 92 (1996), S. 56-63 
    Details
    ISSN: 1432-0533
    Keywords: Key words Brain ; Ultrastructure ; Vascular cast ; Scanning electron microscopy ; Microvasculature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the rat, normal blood flow can be restored in the territory of the occluded artery after an arterial occlusion. This event has been attributed to changes in the collateral vessels supplying the territory of the occluded artery. Since only a limited amount of data is available about the plasticity of the microvascular system after a cortical ischemic lesion, in the present study we have evaluated whether the restoration of blood flow to normal levels in the territory of the middle cerebral artery after permanent ischemia is due only to flow through preexisting collateral vessels or also to the development of new microvessels. Middle cerebral artery occlusion was performed in 45 rats. After 24 h of ischemia, magnetic resonance imaging was used to select 16 rats with cortical lesions of similar size and location. After 2 weeks, vascular corrosion casts were obtained from 8 rats by injection of low-viscosity resin and observed by scanning electron microscopy. A correlative light and electron microscopy study was performed using the remaining 8 rats. Two different patterns of vascular modifications were found, one dorsal and one ventral to the lesion. The dorsal portion of the lesion was vascularized by collateral arteries originating from the anterior or posterior cerebral arteries. Collateral trunks showed a meandering course, mainly in the occipital pole. In the ventral portion of the lesion a complex microvascular system was found characterized by an intense vascular proliferation. The arterioles showed a parallel, candelabrum-like pattern with dichotomic branching. Contraction rings were frequently seen. The capillaries showed a sinusoid-like structure, with a large lumen and a continuous endothelium with many micropinocytotic vesicles. A peripheral ring-shaped venous sinus was composed of a network of flat vessels. These results give the first comprehensive description of the microvascular modifications in a focal model of infarct and suggest that the restoration of blood flow to normal levels described in the territory of the middle cerebral artery after permanent ischemia may be due not only to flow through collateral vessels but also to the development of a new vascular system originating mainly from branches of the middle cerebral artery before the occlusion point.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050489
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  • 184
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    Electronic Resource
    Synaptology of the olfactory bulb of an elasmobranch fish, Sphyrna tiburo (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 101-114 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Olfaction ; Sharks ; Basal dendrites ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructure of the elasmobranch olfactory bulb was examined in order to determine the synaptology of the olfactory circuitry in the bonnethead shark, Sphyrna tiburo. The compartmentalization of the bulb, together with the lack of mitral cell basal dendrites, suggests a different way of performing lateral communication between mitral cells of the olfactory bulb. The results show that granule cells assume an important role by directly interlinking mitral cells. A corollary of this is the segregation of the input onto the mitral cell dendritic arborization: afferent fibers synapse onto the intraglomerular mitral terminals, whereas most local circuit interactions utilize extraglomerular synapses located on the shafts and the somas of the mitral dendrites. Therefore, the elasmobranch synaptic pattern is different from that of higher vertebrates; This might represent the use of a different neural route to achieve the same processing task.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214701
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  • 185
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    Electronic Resource
    Synaptic organization of afferent projections to the supramammillary nucleus of the rat (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 249-257 
    Details
    ISSN: 1432-0568
    Keywords: WGA-HRP ; anterograde tracing ; Ultrastructure ; Preoptic area ; Nucleus of diagonal band ; Laterodorsal tegmental nucleus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied the fine structure of afferent terminals from the preoptic area, the nucleus of the diagonal band of Broca, the infralimbic cortex and the laterodorsal tegmental nucleus within the supramammillary nucleus (SUM) using the anterograde tracing method of horse-radish peroxidase conjugated with wheat germ agglutinin (WGA-HRP). Injection of WGA-HRP into the preoptic area permitted ultrastructural recognition of many anterogradely labeled terminals in the SUM. Almost all labeled terminals (99%) contained clear round synaptic vesicles and formed asymmetric synaptic contacts (Gray's type I). About 86% of labeled terminals from the nucleus of the diagonal band were asymmetric (Gray's type I), whereas 14% contained pleomorphic synaptic vesicles and formed symmetric synaptic contacts (Gray's type II). Almost all labeled terminals from the infralimbic cortex were located in the ventral part of the SUM, and 95% of labeled terminals were Gray's type I. The majority of labeled terminals (90%) from the laterodorsal tegmental nucleus were Gray's type I, and the remaining (10%) were Gray's type II. The percentage of labeled terminals with dense-cored vesicles was very high in terminals from the preoptic area (70%), and low in terminals from the infralimbic cortex (19%). Labeled terminals in all cases contacted mainly intermediate-sized dendrites (0.5–1.0 μm diameter). All cases had only a few labeled axosomatic terminals. The cases of injections into the preoptic area and the diagonal band nucleus had some reciprocal connections at the ultrastructural level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00198328
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  • 186
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    Characterization of the interstitial cells associated with the submuscular plexus of the guinea-pig colon (1996)
    Springer
    Anatomy and embryology 194 (1996), S. 49-55 
    Details
    ISSN: 1432-0568
    Keywords: Pacemaker ; Interstitial cells of Cajal ; Intestine ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Interstitial cells associated with the submuscular plexus of the guinea pig colon were studied by electron microscopy and by light microscopic wholemount stretch preparations. Their cytoplasmic features are similar to those of fibroblasts and they contain a well-developed Golgi apparatus, granular endoplasmic reticulum and many mitochondria. Intermediate filaments are abundantly distributed throughout the perinuclear region and processes. Numerous caveolae, a basal lamina and subsurface cisterns are observed on the cell membrane as in smooth muscle cells. The most characteristic feature of this cell type is the existence of many large gap junctions that interconnect these cells to each other and with the smooth muscle cells. Nerve varicosities containing synaptic vesicles are observed in close apposition with cells of this type. Whole-mount preparations stained by the zinc iodide-osmic acid method and by vimentin immunohistochemistry clearly demonstrated the stellate form of these gap junction-rich cells and suggested that they correspond to the interstitial cells of Cajal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00196314
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  • 187
    Electronic Resource
    Electronic Resource
    Effects of long-term open-air exposure to fluoride, nitrogen compounds and SO2 on visible symptoms, pollutant accumulation and ultrastructure of Scots pine and Norway spruce seedlings (1996)
    Springer
    Trees 10 (1996), S. 157-171 
    Details
    ISSN: 0931-1890
    Keywords: Key words Conifer ; Fluoride ; Nitrogen ; Sulphur dioxide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Effects of SO2, aqueous fluoride (NaF) and a solution of nitrogen compounds (NH4NO3) on the visible symptoms, pollutant accumulation and ultrastructure of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L.) Karst.] seedlings were studied in an open-air experiment lasting for 3 consecutive years. Visible injury symptoms were most pronounced in combination exposures and whenever F was applied. Visible symptoms correlated well with needle pollutant concentrations. Exposure to NaF increased needle F contents particularly when F was applied with SO2 or NH4NO3. This suggests that a reduction in N or SO2 emissions, in F polluted areas, could improve the condition of conifers via decreased accumulation of phytotoxic F in the needles. Norway spruce needles accumulated 2 – 10 times as much S and F as those of Scots pine. Microscopic observations showed various changes in the needle mesophyll cell ultrastructure. In both species, exposure to SO2 increased significantly the amount of cytoplasmic vacuoles, suggesting detoxification of excess sulphate or low pH. F treatments resulted in a significant enlargement of plastoglobuli in Scots pine and a darkening of plastoglobuli in Norway spruce. All exposures enhanced the accumulation of lipid bodies. An increased portion of translucent plastoglobuli was most pronounced in N treatments. Many of the ultrastructural changes and visible symptoms appeared only as number of years exposed increased, indicating that long-term experiments are needed. Both visible symptoms and ultrastructural changes pointed to the more pronounced sensitivity of Norway spruce compared to Scots pine. Ultrastructural results mostly supported earlier qualitative observations of F, N and SO2 effects on needle mesophyll cell ultrastructure. However, no reduction of thylakoids in SO2 containing exposure or curling of thylakoids in F exposure could be detected in the present study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00009644
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  • 188
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    Coexistence of paired helical filaments and polyglucosan bodies in the same neuron in an autopsy case of Alzheimer’s disease (1996)
    Springer
    Acta neuropathologica 92 (1996), S. 511-514 
    Details
    ISSN: 1432-0533
    Keywords: Key words Paired helical filament ; Polyglucosan ; body ; Alzheimer’s disease ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The coexistence of polyglucosan bodies (PBs) and paired helical filaments (PHFs) in the same neuron is reported in an autopsy case of Alzheimer’s disease. The patient was a 56-year-old Japanese male with a typical clinical course and pathological findings of Alzheimer’s disease. Electron microscopically, numerous neurofibrillary tangles, mainly composed of PHFs, were observed in the neuronal cytoplasm, axons and dendrites. Some of them coexisted with other filamentous structures, which comprised randomly oriented branching filaments with a diameter of 5–10 nm. These structures were compatible with PBs. Glial tangles could not be found. Coexistence of these two structures was thought to occur in neurites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050553
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  • 189
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    Early ultrastructural changes after brief histotoxic hypoxia in cultured cortical and hippocampal CA1 neurons (1996)
    Springer
    Acta neuropathologica 92 (1996), S. 541-544 
    Details
    ISSN: 1432-0533
    Keywords: Key words Neuronal cultures ; Iodoacetate ; Histotoxic ; hypoxia ; Ribosomes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Primary cortical and hippocampal neuronal cultures submitted to brief histotoxic hypoxia suffer delayed neuronal death after 24 h [Uto et al. (1995) J Neurochem 64: 2185–2192]. In this study the ultrastructural changes were monitored during the first 6 h following 5-min histotoxic hypoxia induced by exposure to 100 μM iodoacetate. In both cortical and hippocampal CA1 neurons, disaggregation of ribosomes was the earliest sign of histotoxic pathology. Vacuolizations of mitochondria, endoplasmic reticulum and Golgi apparatus, as well as fragmentation and disintegration of neurofilaments followed later. Signs of apoptotic nuclear degeneration were absent. Our observations demonstrate that, similar to that seen in ischemia, disaggregation of ribosomes after brief histotoxic hypoxia is one of the first pathological alterations heralding delayed neuronal death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050559
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  • 190
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    Eosinophilic bodies in the cerebral cortex of Alzheimer’s disease cases (1996)
    Springer
    Acta neuropathologica 92 (1996), S. 555-561 
    Details
    ISSN: 1432-0533
    Keywords: Key words Homogeneous dense body ; Alzheimer’s disease ; Ultrastructure ; Axonal dystrophy ; Eosinophilic body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The light microscopical, immunohistochemical and ultrastructural aspects of eosinophilic bodies in the cerebral cortex from patients with Alzheimer’s disease (AD) are described, based on a study of 16 cases of AD, 5 elderly non-demented controls and, as disease controls, 5 cases of Pick’s disease, 9 with progressive supranuclear palsy, 5 with Creutzfeldt-Jakob disease and 1 with Binswanger’s disease. At the light microscopy level, the bodies were clearly separated from the surrounding tissues and were mostly round or elliptic with a diameter of 5–30 μm and a central, intensely eosinophilic core. Ultrastructurally, they consisted of a central homogeneous electron-dense body (HDB), and filamentous structures (resembling either neurofilaments or paired helical filaments) or other small organelles in the periphery. Immunohistochemically, some of these bodies exhibited ring-shaped rims which were positive with antibodies against paired helical filaments, tau-2, phosphorylated neurofilaments and ubiquitin. The bodies were widely distributed throughout the cerebral cortex, but were not observed in the white matter. These bodies were thought to be compatible with one type of axonal dystrophy in the gracile nucleus (termed ‘old’ spheroid by Jellinger), and are here referred to as the HDB-type spheroid based on their ultrastructure. In this study HDB-type spheroids were found in high incidence in the AD cases, but only two HDB-type spheroids were seen in one case of Pick’s disease, and none in any of the other cases of neurodegenerative diseases or in the elderly non-demented controls. It seems plausible that the incidence of HDB-type spheroids in the cerebral cortex might be related to a pathological process and not to a physiological ageing phenomenon, and might be characteristic of, but not unique to, AD.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050561
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  • 191
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    Early organization of the pituitary gland in Sparus aurata L. (Teleostei) An ultrastructural study (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 441-452 
    Details
    ISSN: 1432-0568
    Keywords: Pituitary gland ; Development ; Ultrastructure ; Sparus aurata (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cell organization of the pituitary gland and the relationship between neurohypophysis and adenohypophysis in the early developmental stages of the gilthead sea bream, Sparus aurata, were studied by electron microscopy. In newly hatched larvae, the pituitary gland was embedded in the ventral floor of the diencephalon and separated from the hypothalamus by a continuous basal lamina. Elongated mesenchymal cells next to the ventral surface were observed. At this stage, there was no neurohypophysis and the adenohypophysis consisted of undifferentiated endocrine cells with small scarce secretory granules and a few stellate cells, with no distinctive zonation. An incipient neurohypophysis was present in 1-day-old larvae. The first evagination of the neurohypophysis into the adenohypophysis were observed in 2-day-old larvae and developed progressively with age, being deeper in the caudal zone. Two regions in the adenohypophysis, one anterior — the presumptive pars distalis — and one posterior — the presumptive pars intermedia — were found in 2-day-old larvae. Three regions (rostral and proximal pars distalis and pars intermedia) were clearly distinguishable in 4-day-old larvae. The ultrastructural features of the pituitary endocrine cells varied during gland differentiation, with the secretory granules gradually increasing in number and size, accompanying organelle development. Nevertheless, even in the oldest larvae studied (65 days), undifferentiated cells similar to those in the earliest stages were observed. The first blood vessels appeared in the neurohypophysis around 16 days after hatching. During early development, the pituitary gland progressively emerged from the ventral floor of the brain. By 16 days, the principal pattern of the pituitary gland architecture appeared to be established.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185875
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  • 192
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    Synaptic loss in anterior horn neurons in lower motor neuron disease (1996)
    Springer
    Acta neuropathologica 91 (1996), S. 416-421 
    Details
    ISSN: 1432-0533
    Keywords: Key words Motor neuron disease ; Anterior horn ; neuron ; Synapse ; Active zone ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an ultrastructural investigation of the synapses of anterior horn neurons in the lumbar spinal cord of four patients with lower motor neuron disease (LMND) who had no upper motor neuron and corticospinal tract involvement. Anterior horn neurons of five normal individuals served as controls. The cell body area and the number of synapses of the normal-appearing neurons of the LMND patients were significantly reduced (P 〈 0.0001). These findings suggest that synaptic changes of anterior horn neurons could be ascribed to the degeneration of lower motor neurons rather than to the influence of upper motor neuron system degeneration. On the other hand, the lengths of individual synapses (P 〈 0.0001) and of their active zones (P 〈 0.05) were significantly increased in the patients. These increases would indicate that synapses on anterior horn neurons of individuals with LMND appear to have the capacity to react to progressive degeneration and loss of other synapses by means of a compensatory response or plasticity that enhances their efficiency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050444
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  • 193
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    Rattan bamboo blind (Japanese sudare)-like profiles of neurofibrillary tangles in Alzheimer’s disease (1996)
    Springer
    Acta neuropathologica 91 (1996), S. 448-450 
    Details
    ISSN: 1432-0533
    Keywords: Key words Neurofibrillary tangles ; Alzheimer’s ; disease ; Ultrastructure ; Rattan bamboo blind-like ; arrangement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An unusual ultrastructure for neurofibrillary tangles, which has not been described so far, is presented in a case of Alzheimer’s disease. This profile consists of parallelly arranged paired helical filaments and criss-cross tubular profiles that are arranged at regular interval of 300–500 nm, resembling rattan bamboo blind or Japanese sudare-like profiles. Coexistence of Hirano bodies in the same neuron is infrequently encountered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050451
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  • 194
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    Ultrastructural consequences of radical damage before and after differentiation of neuroblastoma B-104 cells (1996)
    Springer
    Acta neuropathologica 92 (1996), S. 75-89 
    Details
    ISSN: 1432-0533
    Keywords: Key words Radicals ; Neuron ; Ultrastructure ; Differentiation ; Golgi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract There is abundant evidence that the pathophysiology leading to neuronal death during post-ischemic brain reperfusion involves radical-mediated damage. Although the ultrastructural alterations accompanying brain ischemia and reperfusion are well characterized, little is known about the ultrastructural alterations that are specific to radical damage. This study examines in differentiated and undifferentiated neuroblastoma B-104 cells the viability (by dye exclusion) and ultrastructural consequences of radical damage initiated by 50 μM cumene hydroperoxide (CumOOH). Differentiation was most notably associated with formation of neurites and an extensive cytoskeletal feltwork. CumOOH-induced cell death was increased after differentiation and was blocked by the iron chelator DETAPAC. The ultrastructural characteristics of radical damage here included: (1) plasmalemmal holes that appear to undergo “patching” by well-organized membrane whorls, (2) accumulation of numerous free ribosomes, (3) markedly increased vesicular trafficking about the Golgi accompanied by Golgi transformation from cisternal organization to clusters of vacuoles with numerous fusing vesicles, (4) development of large multi-layered vacuoles that include damage membranes and organelles and appear to undergo extrusion from the cell, and (5) a general loss of cytoplasmic volume. These ultrastructural alterations developed more rapidly and were consistently more advanced in differentiated cells throughout the 6-h time course. In differentiated cells radical damage also induced the disorganization and subsequent loss of the extensive feltwork of cytoskeletal elements. There was little damage to the membranes of the nuclear envelope and mitochondria. Our observations in this system are strikingly similar to ultrastructural alterations in Golgi and ribosomal organization seen in vulnerable neurons during post-ischemic brain reperfusion and suggest that these alterations during reperfusion reflect the consequence of radical-mediated damage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050492
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  • 195
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    Tectorial membrane-organ of Corti relationship during cochlear development (1996)
    Springer
    Anatomy and embryology 194 (1996), S. 501-514 
    Details
    ISSN: 1432-0568
    Keywords: Inner ear ; Hair cell ; Stereociliary attachment ; Mouse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The development of stereociliary attachment to the tectorial membrane was investigated in the mouse cochlea using transmission and scanning electron microscopy. At the 18th gestational day, only the major tectorial membrane can be identified covering the greater epithelial ridge and the inner hair cells in all turns. At the 19th gestational day, the minor tectorial membrane was first seen in the basal turn, over the outer hair cells. During early stages of development, the stereocilia of hair cells were surrounded by a loose fibrillar material underneath the tectorial membrane. After the 10th postnatal day, the outer hair cells' stereocilia were attached to Kimura's (or Hardesty's) membrane, while inner hair cells' stereociliary bundles were attached to the undersurface of the tectorial membrane near the Hensen's stripe. Between the 10th and the 14th postnatal days, the space between the inner hair cells and the first row of outer hair cells widened by virtue of the growth of the heads of pillar cells, and the inner hair cells' stereocilia were displaced towards the Hensen's stripe. After the 14th postnatal day, the inner hair cells' stereociliary bundles detached from the tectorial membrane, while the outer hair cells' stereocilia remained attached to it. The tip-link system, which connects the tips of the stereocilia to the next tallest stereocilia, is present at birth in the outer hair cells. The marginal pillar, that anchored the tectorial membrane to the underlying organ of Corti during development, first appeared on the 6th postnatal day and disappeared on the 14th–15th postnatal day. The present data together with other reports support the idea that although some structures, such as hair cells' stereocilia and innervation, are already formed early during development, the cochlear microarchitecture is not fully developed morphologically and ready to function normally until the end of the second postnatal week in the mouse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185996
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  • 196
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    Long-term structural alterations to endothelial cells in vein-to-artery grafts: a quantitative electron microscopic study (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 169-173 
    Details
    ISSN: 1432-0568
    Keywords: Endothelium ; Ultrastructure ; Vein graft ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The intracellular structure of endothelium lining vein-to-artery grafts in rats was analysed, using transmission electron microscopy and morphometry, to determine the ultrastructural adaptations of endothelial cells in this altered vascular environment. Autogenous 4-mm sections of iliolumbar veins were inserted microsurgically into the left common iliac arteries of 16 male Wistar rats. At 3, 6, 26 and 52 weeks the cytoplasmic-vesicular, mitochondrial and rough endoplasmic reticular contents of endothelial cells lining the grafts, the opposite iliac arteries and the remaining ilio-lumbar veins were analysed morphometrically. There was a significant increase in the amount of all these cytoplasmic structures in endothelial cells at 3, 6 and 26 weeks; at 52 weeks there was also a significant increase in the volumes of mitochondria and cytoplasmic vesicles, but not in rough endoplasmic reticulum. It was concluded that the ultrastructure of endothelial cells lining these grafts is changed chronically after graft insertion, and we propose that this may be attributable to altered haemodynamic stresses within the graft.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214707
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  • 197
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    Quantitative electromicroscope study of the oculomotor parasympathetic neurons projecting to the ciliary ganglion in cats: comparison of the synaptic (axo-somatic and axo-proximal dendritic) organization of anterior-dorsal and ventral cell groups (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 229-238 
    Details
    ISSN: 1432-0568
    Keywords: Preganglionic neuron ; Oculomotor nerve ; Parasympathetic nervous system ; Synapse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The synaptic organization of the oculomotor parasympathetic preganglionic neurons (OPNs), labeled retrogradely after a horseradish peroxidase (HRP) injection into the ciliary ganglion, was studied in cats by electron microscopy. We divided the OPNs into two groups, anterior-dorsal (ADG) and ventral (VG) cell groups, based upon physiological studies in cats suggesting that accomodation-related OPNs are predominantly located anterior and dorsal to the somatic nuclei of the oculomotor nuclear complex (i.e., the anteromedian and Edinger Westphal nuclei, and the ventral central gray area), while pupillo-constriction-related OPNs are predominantly located ventral to the somatic nuclei (i.e., the ventral tegmental area). The synaptic organization of these two groups was quantitatively compared, using a nested analysis of variance to determine statistical significance (P〈0.05). Partial reconstructions of the labeled somata and proximal dendrites were made from tracings of electron micrographs of every 2nd section in serial ultrathin sections that included the nucleolus or were adjacent to sections that included the nucleolus. The mean number of boutons of apposition on a reconstructed labeled soma of VG was significantly greater than that of ADG (mean ±SD; ADG, 5.3±3.3; VG, 8.6±3.2). The mean synaptic density on a VG soma was significantly greater than on an ADG soma (mean±SD; ADG, 3.74±2.11 counts/100 (μm2; VG, 6.30±1.99 counts/100 μm2). The mean synaptic covering ratio on a VG soma was significantly greater than on an ADG soma (mean±SD; ADG, 5.21±2.91%; VG, 10.14±3.76%). The mean estimated number of boutons of apposition on a VG soma was significantly greater than on an ADG soma (mean±SD: ADG, 53±36; VG, 100±48). Boutons were classified on the basis of the shape of their synaptic vesicles as S-type (containing spherical clear synaptic vesicles) or P-type (containing both flattened and spherical clear synaptic vesicles). The mean S-type/S+P-type bouton ratio on a VG soma was significantly greater than on an ADG soma (mean±SD; ADG, 0.31±0.20; VG, 0.67±0.18). The differences demonstrated in this study reinforce, morphologically, the assumption of functional localization of OPNs, and further allow us to estimate the relative characteristics of the synaptic organization of accommodation-related OPNs and pupillo-constriction-related OPNs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00198326
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  • 198
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    Ultrastructure of sympathetic axons and their structural relationship with vascular smooth muscle (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 515-531 
    Details
    ISSN: 1432-0568
    Keywords: Sympathetic axons ; Ultrastructure ; Neuromuscular junctions ; Blood vessels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This review focuses on the more recent findings of the structure of sympathetic postganglionic axons and the association of their varicose terminals with vascular smooth muscle. These studies have investigated the innervation of a wide range of vessels from different regions of the vasculature in the rat, guinea pig and rabbit and have predominantly used serial sections and computerised three-dimensional reconstructions of entire varicosities. They have shown, contrary to previous studies conducted in the 1960s and 1970s, that sympathetic axon varicosities commonly form structurally specialised neuromuscular junctions with vascular smooth muscle cells of most resistance arteries and some small veins. In addition, they have shown that most axon varicosities innervating small arterioles and small mesenteric veins form neuromuscular junctions, indicating that neurotransmitter is primarily released at such neuromuscular junctions. This review discusses the structure of sympathetic neuromuscular junctions, their development, structural diversity and distribution on vessels from different regions of the vasculature. These more recent structural findings and their possible significance for our understanding of mechanisms involved in neural transmission in blood vessels is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00187924
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  • 199
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    Morphology of the keratin filament network in palm and sole skin: evidence for site-dependent features based on stereological analysis (1996)
    Springer
    Archives of dermatological research 288 (1996), S. 55-62 
    Details
    ISSN: 1432-069X
    Keywords: Key words Palmar and plantar skin ; Ultrastructure ; Stereology ; Intermediate filaments ; Keratin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ridged or glabrous skin of palms and soles has a specialized function and can be preferentially involved in various disorders of keratinization. To better define the morphological features of ridged skin, we carried out a qualitative and quantitative (stereological) analysis of normal epidermis from the palm and sole of four subjects. Skin from the upper arm was examined for control purposes. The study focused on the appearance and arrangement of the keratin filament network in relation to epidermal differentiation. Whereas palm and sole epidermis was essentially similar both qualitatively and quantitatively, it differed markedly from the epidermis from the arm. The volume density of keratin filaments was significantly higher ( P 〈 0.03) in all subcorneal layers of the palm and sole compared with the arm. The volume density of the keratin filaments increased markedly from the basal to the upper spinous layer of ridged skin and they formed denser aggregates in the upper spinous and granular layers, providing an extensive matrix for the deposition of keratohyalin. The presence of dense keratin aggregates appeared to be a distinct ultrastructural feature of human ridged skin. Such keratin aggregates have not been described in normal skin from other sites, but showed some resemblance to the keratin clumps seen in non-ridged skin of patients with the Dowling-Meara form of epidermolysis bullosa simplex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004030050023
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  • 200
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    Prediction of prognosis by electron microscopic analysis of myeloma cells (1996)
    Springer
    Annals of hematology 73 (1996), S. 169-173 
    Details
    ISSN: 1432-0584
    Keywords: Key words Multiple myeloma ; Ultrastructure ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Myeloma cells were ultrastructurally analyzed in relation to survival in 54 patients with myeloma who were treated with melphalan-prednisolone or cyclophosphamide-prednisolone. Since previous studies by electron microscope had demonstrated that the degree of nuclear-cytoplasmic asynchrony of myeloma cells was associated with poor prognosis, this study focused on three kinds of nuclear abnormalities and eight kinds of cytoplasmic abnormalities. The patients were classified into three groups according to the presence of these abnormalities. The median survival times of the first group with five or fewer of 11 different kinds of abnormalities, the second group with 6–8 abnormalities, and the third group with nine or more abnormalities were 2353, 531, and 115 days, respectively. Furthermore, this classification by ultrastructural abnormalities corresponded to those by the initial hemoglobin concentrations, platelet counts, and percentages of myeloma cells and plasmablasts in the bone marrow. These findings suggest that ultrastructural analysis of nuclear and cytoplasmic abnormalities, in addition to nuclear maturity, of myeloma cells may provide important information for predicting the prognosis in myeloma patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002770050222
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