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  • Electron Microscopy  (156)
  • Springer  (156)
  • Blackwell Publishing Ltd
  • 1970-1974  (156)
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Keywords
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  • Springer  (156)
  • Blackwell Publishing Ltd
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Year
  • 1
    ISSN: 1432-072X
    Keywords: Complex Flagella ; Fine Structure ; Electron Microscopy ; Optical Diffraction ; Flagellin ; Flagellar Motion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Zellen von Rhizobium lupini H 13-3 besitzen 5–10 peritrich inserierte komplexe Geißeln, deren Feinstruktur durch Hochauflösungs-Elektronenmikroskopie und lichtoptische Diffraktion analysiert wurde. Das Geißelfilament hat einen Durchmesser von 160 Å und besteht aus einem zylindrischen Kern (Durchmesser ca. 110 Å), der fest von drei Bändern einer helikalen Scheide umgeben ist. Die Scheidenbänder sind 49 Å breit, durch 49 Å-Intervalle voneinander getrennt und haben eine Steigung von 31°. Die komplexen Geißelfilamente bestehen aus einem 43 000-Dalton-Protein, das den Kern und die helikale Scheide aufbaut. Beide gehen übergangslos aus dem proximalen Geißelhaken hervor, der einen Durchmesser von 150 Å und eine Länge von 600 bis 800 Å hat. Die Diffraktionsanalyse des Geißelhakens zeigte eine helikale Grundanordnung von globulären Untereinheiten, die ein Oberflächengitter von 5 parallelen Schrauben (Steigung 29° bzw. 33°) bilden, von denen jede fast 11 Untereinheiten pro Helixungang trägt. Die komplexen Geißeln von R. lupini H 13-3 und Pseudomonas rhodos [Schmitt et al.: J. Bact. 117, 844–857 (1974)] sind ein neuer Typ von Bakteriengeißeln. Sie zeigen deutliche Übereinstimmung in der Feinstruktur, der festen Verbindung von helikaler Scheide und Geißelhaken sowie in der Fragilität ihrer Filamente; sie unterscheiden sich deutlich im Molekulargewicht der Flagellinmonomeren (43 000 bzw. 55 000). Zellen von R. lupini H 13-3 führen schnelle, vibrierende Translationsbewegungen aus. Mögliche Mechanismen der Bewegung komplexer Geißeln werden diskutiert.
    Notes: Abstract Cells of Rhizobium lupini H 13-3 possess 5 to 10 peritrichously inserted complex flagella, which were analyzed by high resolution electron microscopy and by optical diffraction. The flagellar filament has a diameter of 160 Å; it consists of a cylindrical core (diameter approximately 110 Å) surrounded by three close-fitting bands of a helical sheath. The helical bands are 49 Å wide, separated by axial intervals, 49 Å wide, and run at an angle of 31°. Complex filaments consist of a 43 000-dalton protein representing the core and the helical sheath. These originate from the proximal hook, which has a diameter of 150 Å and a length of 600 to 800 Å. The diffraction analysis of the hook showed a helical arrangement of globular subunits forming a surface of 5 parallel “small-scale” helices (pitch-angles 29° and 33°, respectively), each carrying almost 11 subunits per period. The complex flagella of R. lupini H 13-3 and Pseudomonas rhodos [Schmitt, et al.: J. Bact. 117, 844–857 (1974)] represent a novel type of bacterial flagella. There is agreement in their fine structures, in the intimate connection of the helical sheath and the core, and in the fragility of their filaments. Thery are clearly distinguished by the molecular weights of their flagellin monomers (43 000 and 55 000, respectively). Cells of R. lupini H 13-3 show fast, vibrating, translational motions. Possible mechanisms of complex flagellar motion are discussed.
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  • 2
    ISSN: 1432-072X
    Keywords: Bdellovibrio bacteriovorus ; Spirillum serpens ; Freeze Fracture ; Electron Microscopy ; Ultrastructure ; Membrane Damage ; Organismic Associations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The freeze-fracture technique and electron microscopy have been used to demonstrate that localized damage is inflicted upon the cytoplasmic membrane of Spirillum serpens VHL within 20 to 30 min after the start of its association with Bdellovibrio bacteriovorus 109D. This damage is not observed in uninfected Spirillum cells, nor in infected cells within the first 10 min. This damage takes the form of a “blister” which, when viewed stereoscopically in electron micrographs, is seen to project toward the interior of the Spirillum cell. Shortly after its formation, the blister becomes elaborated into a series of ridges which may assume forms ranging from an elaborate spiral to a series of loops or knots. The formation of a blister is shown to involve both the inner and outer leaves of the membrane bilayer, and evidence is presented to indicate that the blister site corresponds to the site of attachment of the Bdellovibrio cell. The hypothesis is proposed that this ultrastructural damage is the cytological basis for the controlled and localized leakage through the cytoplasmic membrane into the periplasmic space of the Spirillum cell at locations adjacent to the Bdellovibrio cell. It is suggested that this localized membrane damage may be the ultrastructural basis for the high efficiency with which bdellowvibrios are known to incorporate cytoplasmic materials from the other bacteria in whose periplasmic spaces they develop.
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  • 3
    ISSN: 1432-2307
    Keywords: Hypertensin (Angiotensin) ; Catecholamins ; So-Called Epinephrine Myocarditis ; Rat Heart ; Optical Microscopy ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pathomorpliological comparative studies on structural damage to rat cardiac muscle following administration of hypertensin and arterenol, with and without pretreatment with reserpine to empty the catecholamine reserves were performed. The question is whether and to what degree angiotensin induced cardiac damage, which is viewed microscopically as the so-called epinephrine myocarditis, can be regarded as an indirect catecholamine effect. The following could be deduced: 1. Hypertensin causes a damage pattern similar to that of arterenol as seen under the light microscope and corresponds to the so-called epinephrine myocarditis. 2. The electron microscope demonstrates definite differences in the pattern of damage to the myocardium: hypertensin affects primarily the mitochondria, while arterenol affects the myofibrils. 3. Hypertensin and arterenol damage mainly the subendocardial tissue of the left heart: hypertensin affects more the region of the base of the left ventricle, arterenol more the region of the left ventricle apex. 4. Pretreatment with reserpine blocks the damaging effects of hypertensin in the rat heart for 12 hours. After 24 hours the full picture of the damage pattern has reappeared. Arterenol is lethal to animals pretreated with reserpine. 5. The pathogenesis of the damaging effects of hypertensin on rat cardiac muscle is discussed.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 364 (1974), S. 111-127 
    ISSN: 1432-2307
    Keywords: Electron Microscopy ; Coronary Arteries ; Atherosclerosis ; Aging ; Smooth Muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The coronary arteries were studied by electron microscopy in normal rats weighing 65 to 535 gm; fixation was accomplished by perfusion for 20 min at 110–130 mm Hg. In rats of all ages (but especially in the oldest) the arterial wall contained deposits of abnormal intercellular material, consisting of granules, vesicles, myelin figures and other debris. These deposits were present in the intima and media, but rare in the adventitia; there was suggestive evidence that medial cells phagocytized some of the material. The adventitia was characterized by 1–4 layers of cells with extremely thin protoplasmic expansions wrapped around the vessel (“veil cells”) and containing lysosome-like bodies as well as phagosomes. These findings, taken as a whole, suggest the following sequence of events. During normal life, the media produces cellular debris, by cell death as well as by fragmentation of cellular processes; part of these debris are phagocytized by smooth muscle cells, part diffuse outward to the adventitia where they are taken up by specialized cells (the “veil cells”). However, due to relative inadequacy of phagocytosis in the media, the debris continue to accumulate and form intercellular deposits that increase with age. It is possible that this natural phenomenon may by itself set a maximal limit to the life-span of the arterial wall.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 30 (1974), S. 271-276 
    ISSN: 1432-0533
    Keywords: Intracranial Teratoma ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A massive congenital benign teratoma grossly replacing the cerebral hemispheres has been examined by light and electron microscopy. The tumor contained tissues derived from all three germ layers. The cerebellum showed morphological features suggesting a state of maturation equivalent to that of 20 to 25 weeks of gestation. The tumor is discussed in the light of present theories on the pathogenesis of teratomas.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 27 (1974), S. 1-10 
    ISSN: 1432-0533
    Keywords: Leprosy ; Lepromatous ; Axonal Bacillation ; Schwann Cells ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary M. leprae bacilli in nerves of 3 patients with lepromatous leprosy were found in the axoplasm of myelinated and unmyelinated nerve fibers. Axonal bacillation occurred in as much as 2% of myelinated axons. Bacilli within Schwann cells were a more common finding in lepromatous leprosy that intra-axonal bacilli. Intra-axonal bacillation probably represents a late stage phenomenon in lepromatous leprosy. Intra-axonal bacilli may contribute to the dissemination of leprosy by migration of bacilli within the axon, and may contribute directly to nerve fiber destruction.
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  • 7
    ISSN: 1432-0533
    Keywords: Experimental Neural Tumours ; Ethylnitrosourea ; Electron Microscopy ; Thiamine Pyrophosphatase ; Adenosine Triphosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural localisation of thiamine pyrophosphatase and adenosine triphosphatase was carried out in gliomas and schwannomas induced transplacentally by N-ethyl-N-nitrosourea. The activity of thiamine pyrophosphatase was observed in the Golgi complexes and appeared to be directly related to cellular differentiation and reactive changes. The Mg2+-dependent adenosine triphosphatase was localised at the cell membrane, in the pinocytotic vesicles of various cells and in the basement membrane of some capillaries. This enzyme, showing high activity in differentiated cells, indicated the activity of membrane-bound cellular transport.
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  • 8
    ISSN: 1432-0533
    Keywords: Craniopharyngioma ; Tissue Culture ; Electron Microscopy ; Enzyme Histochemistry ; Keratine ; Enamel ; Rosenthal Fibers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron optical and enzyme histochemical investigations carried out on four craniopharyngiomas and their tissue cultures demonstrated that the tumour elements are keratinizing epithelial cells, plenty of tonofilaments, glycogen granules, mitochondria and desmosomes. Their ultrastructural and histochemical characteristics are the same in every part of the tumour (solid; cystic; “adamantinoma-like”). In the keratinizing cells, the reactions for non-specific esterases were high positive. The ultrastructural characteristics of the tumour cells grownin vitro are the same as thosein situ; the cells remain attached to one another by desmosomes and retain their capacity to produce keratine. This therefore seems to be a primary characteristic of the tumour cells and not a secondary dysmetabolic disturbance. Calcium was found onlyin situ. That the tumour cells may produce enamelin situ seems to be possible, but it could not be confirmed with certainty. The glial proliferation which is always presentin situ, is reactive and not neoplastic; thein vitro new built cell colonies consist only of epithelial elements.
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  • 9
    ISSN: 1432-0533
    Keywords: GM1 Gangliosidosis ; Friesian Calves ; Inborn Metabolic Error ; Histochemistry ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histoenzymic and ultrastructural alterations in the brains of seven calves with GM1 gangliosidosis are described. A decreased oxidative enzyme activity in neurons was accompanied by an increase in acid phosphatase activity. Membranous cytoplasmic bodies were present in neurons and glia. The periodicity of the membranes was about 5.5 to 6.0 nm. Electron-dense, membrane-bound inclusions were present in perithelial cells. The lesions were compared with those of gangliosidoses in other species.
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  • 10
    ISSN: 1432-0533
    Keywords: Aseptic Meningitis ; Atheromatous Material ; Hypersensitivity ; Electron Microscopy ; Macrophages ; Pia-Arachnoid ; Granuloma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 500 mg of sterile pooled human atheromatous material was injected into the cisterna magna of 6 mongrel dogs. Repeated cisternal punctures were done at various intervals until sacrifice from 1 day to 28 days following injection. CSF was obtained for cell count, sugar, protein and analysis in the Technicon 6/60 which measured 14 additional chemical and enzymatic variables. All 6 animals showed a prompt cerebrospinal fluid (CSF) pleocytosis which largely subsided during the first 2 weeks after injection. Increased CSF protein content developed more slowly, but was more prolonged than the pleocytosis. There was a variable decrease in CSF sugar and increase in CSF lactate dehydrogenase, calcium and inorganic phosphorous. Light and electron microscopic studies showed an intense acute inflammatory reaction with marked phagocytosis of the foregin material, probably by arachnoidal cells and moderate edematous changes in the astrocytic processes at the site of injection. During the first 2 weeks after the injection the inflammatory reaction became chronic and the edematous changes in the medulla subsided.
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  • 11
    ISSN: 1432-0533
    Keywords: GM1-Gangliosidosis ; Glycoproteins ; β-Galactosidase ; Lysosomal Disease ; Electron Microscopy ; Genetics of GM1-Gangliosidosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Post-mortem studies on a 6-year old boy with GM1-gangliosidosis, Type II revealed no evidence of accumulation of residual bodies nor of gangliosides or glycoproteins in liver and spleen. In brain tissue the ganglioside GM1 accounted for 70% of the ganglioside fraction and ganglioside-NANA was increased 3.6 fold over controls. In addition, the brain tissue contained large amounts of glycoprotein, glycoprotein derived galactose being increased 2.5 times. The neuronal accumulation of tertiary lysosomes exhibited a characteristic distributional pattern: in general the large neuronal perikarya were more consistently involved with the exception of the motor cells of the cranial nerve nuclei, III, IV, and VI. In addition to characteristic MCB's, the nerve cells contained residual bodies with a granulo-floccular matrix, presumed to represent glycoproteins. The distribution of the mutant gene was studied among 30 blood relatives of the proband at risk and 6 carriers could be ascertained on the basis of a reduced leukocytic β-galactosidase activity. The partly purified enzyme from the patient's liver revealed 20% activity as compared to that of normal controls. All three fractions obtained by DEAE cellulose column chromatography exhibited markedly reduced activity at pH 3.6, but nearly normal activity at pH 6.6. The reduced activity corresponded to the B component of the enzyme as shown by electrophoretic separation. It is pointed out that this case cannot be diagnosed as “generalized gangliosidosis” for the process of ganglioside accumulation was restricted to nervous tissue.
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  • 12
    ISSN: 1432-0533
    Keywords: Reacting Astrocytes ; Phagocytosis ; Experimental Gliomas ; Ethylnitrosourea ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of reacting astrocytes in experimental gliomas has been described. These tumours were induced transplacentally by 30 mg of N-ethyl-N-nitrosourea per kg of body weight injected into the tail vein of pregnant BD-IX rats on the 15th day of gestation. In tumour-bearing animals astrocytes undergo striking morphological changes and show increased mitotic activity. Reacting astrocytes around gliomas display large, eccentric, irregular nuclei and the abundant cytoplasm contains an increased number of cell organelles. The most dramatic increase is in glial filaments: these form thick bundles at the periphery of the cells and in the processes which are frequently seen around demyelinated axons. Reacting astrocytes engulf and break down myelin sheaths: their remnants, lamellar inclusion bodies and lipid droplets, are present in the cytoplasm. Extravasated erythrocytes are also surrounded by and digested in reacting astrocytes. Numerous lysosomes could provide the necessary enzymes for the phagocytic activity of these cells.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 30 (1974), S. 189-196 
    ISSN: 1432-0533
    Keywords: Lafore Bodies ; Polysaccharidosis ; Electron Microscopy ; Epilepsia ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral biopsies of three patients aged 22, 18 and 16 years with myoclonic epilepsy contained Lafory bodies. Two were a brother and sister of consanguineous parents. The Lafora bodies occurred in most neurons but not in glial cells. The ultrastructure of these bodies showed a fibrillar and granular material in the perikaryon and neuropile. In some neurons small Lafora bodies were delimited by a double membrane, suggesting that in early phases they have a membrene which disappears when they become more developed. Other non-specific neuron alterations are described. One of the cases presented in the liver PAS positive bodies of a structure different from the Lafora bodies.
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  • 14
    ISSN: 1432-0533
    Keywords: Human Adenovirus Type 12 ; Sprague-Dawley Rats ; Intracerebral Inoculation ; Medulloepitheliomatous Neoplasm ; Giant Tumor Cells ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Solid medullary brain and spinal cord neoplasms developed in all 10 offspring of an outbred Sprague-Dawley rat, between 37 and 99 days after a single postnatal (within 24 hrs) inoculation of 0.05 ml of human adenovirus type 12, 103.5–104.5 TCID50 HeLa cells/0.1 ml in the left frontal lobe. Seven rats developed multicentric neoplasms in both hemispheres and in peri-aqueductal areas of the brain stem, one of which was associated with an incipient spinal cord tumor in the sacral segment. One rat developed a solid tumor involving the right parieto-occipital region. The remaining two cases were solid spinal cord tumors arising from the dorsal half of the thoracolumbar segments. The remarkably uniform microscopic appearance was designated as a counterpart of human embryonic neuronal neoplasms. Characteristic neuronal and multinucleated giant cells emerged throughout the tumor tissue with argentaffine, neurofibril-like cytoplasmic expansions and a unique cilium (a 9+0 pattern of tubules) associated with a pair of centrioles. This cilium morphology was also a hallmark of the majority of tumor cells that formed characteristic pseudorosettes. The occasional emergence of two sets of cilia and centrioles in monstrous cells suggested probable modes of cytogenesis in relation to cessation of abnormal cell division.
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  • 15
    ISSN: 1432-0533
    Keywords: Infantile Neuroaxonal Dystrophy ; Spheroids ; Perikaryon ; Electron Microscopy ; Membranous Profiles ; Dense Bodies ; Protein Syntheses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic findings of a cortical biopsy from a four-year-old child suffering from muscular weakness and psychomotor retardation are presented. Morphological evidence obtained in this study suggests a unique pathogenetic mechanism underlying INAD. The spheroids appear to be caused by an accumulation of a macromolecular substance synthesized in the neuron and transported to the nerve endings. The abnormal substance initially takes the form of an amorphous material, it eventually aggregates into highly characteristic angulated membranous profiles. The selective involvement of the nerve endings, synapses and motor end plates in this disease suggests a derangement of the metabolic pathway in the synthesis or packaging of the neurotransmitters or their receptors.
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  • 16
    ISSN: 1432-0533
    Keywords: Werdnig-Hoffmann's Disease ; Electron Microscopy ; Muscle Biopsy ; Myotube-like Cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study was carried out on muscle biopsies of 7 children with Werdnig-Hoffmann's disease. The muscle fibres were classified into 3 categories: 1. Muscle cells of normal diameter without any distinct or only slight changes. 2. Small muscle cells with a large central nucleus with the appearance of myoblast at a later stage of development. 3. Cells resembling myotubes containing in a common basement membrane two to four cells at different stages of maturation. Myoblast and myotube-like cells seemed to resemble foetal muscle fibres. Such fibres appear to represent an arrest in maturation rather than muscle atrophy.
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  • 17
    ISSN: 1432-0533
    Keywords: Neuroaxonal Dystrophy ; Infantile Autonomi Nervous System ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The autonomic nervous system is studied by electron microscopy for the first time in two siblings born of North African consanguineous parents and affected by infantile neuroaxonal dystrophy. The changes already reported in dystrophic axons of the central and peripheral nervous system, are seen in the myenteric plexus of rectum mucosa. The authors stress the diffuse involvement of the nervous tissue in this degenerative disorder of still unknown nature.
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  • 18
    ISSN: 1432-0533
    Keywords: Jimpy Mouse ; Electron Microscopy ; Mouse Mutant ; Myelination ; Axonal Growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative study of the myelination and axonal growth in the corpus callosum and posterior columns of the spinal cord in the Jimpy mouse gave the following results: The reduction in the number of myelinated fibers is much more important in regions with late myelination, e.g. corpus callosum and pyramidal tracts than in the previously myelinated fascicles of Goll and Burdach. There is an important delay in the increase in volume of axons particularly within the structures of late myelination. The importance of the lacking axonal growth in relation to myelination is discussed.
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  • 19
    ISSN: 1432-0533
    Keywords: Experimental Neural Tumours ; Ethylnitrosourea ; Electron Microscopy ; Lysosomes ; Acid Phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight was administered to pregnant BD-IX rats on the 15th day of gestation. The neural tumours which developed in 97.5% of the offspring were gliomas and schwannomas. The demonstration of acid phosphatase in the neoplastic and reacting cells of these tumours was carried out at fine structural level. The enzyme activity was localised in lysosomes and in the innermost cisternae of the Golgi complexes. High acid phosphatase activity was related not only to degeneration, necrosis and phagocytosis but also to cellular differentiation and anaplasia.
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  • 20
    ISSN: 1432-0533
    Keywords: Polyneuropathy Associated with Adie's Syndrome ; Sural Nerve ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sural nerve of a woman of 35 with chronic polyneuropathy and Adie's syndrome was examined by electron microscopy. Myelinated nerve fibres were absent and there was marked reduction in the number of unmyelinated fibres. Onion bulb formation was not observed. Collagen fibres occupied the intercellular spaces.
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  • 21
    ISSN: 1432-0533
    Keywords: Steele-Richardson-Olszewski Syndrome ; Progressive Supranuclear Palsy ; Neurofibrillary Tangles ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The neurofibrillary tangles found in the neurons of a case of Steele-Richardson-Olszewski syndrome were studied by electron microscopy. Both the flame-shaped and globose type of tangles were present. The neurofibrillary tangles were composed of bundles of straight tubules measuring approximately 150 Å in diameter. This ultrastructural appearance of the tangles in Steele-Richardson-Olszewski syndrome is different from the appearance of tangles found in other neurological disorders and is probably indicative of intraneuronal accumulation of a new type of fibrous protein.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 29 (1974), S. 211-222 
    ISSN: 1432-0533
    Keywords: Experimental Gliomas ; Ethylnitrosourea ; Electron Microscopy ; Virus-like Particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two unusual, intracytoplasmic structures, resembling viruses, are described in experimental gliomas which were induced transplacentally on the 15th day of gestation in BD-IX rats by a single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight. These structures are tubules within the lumen of the endoplasmic reticulum and large coated vesicles in the Golgi region. The tubules are of indeterminate length and have inner and outer walls of 9–11 nm and 20–22 nm respectively. The large coated vesicles are 80–90 nm in diameter and their outer surface is covered by regular, equidistant spikes of 12–15 nm in length. The vesicles are closely related to the Golgi complexes, from which they appear to originate. The intracisternal tubules and large coated vesicles share certain morphological features both with viruses and with normal cell organelles. The origin and significance of these structures are discussed.
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  • 23
    ISSN: 1432-0533
    Keywords: Organic Mercury Compound ; Late Pathological Changes in Peripheral Nerves ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar strain of male rats of 100–110 g were used, 5 for an experimental and 5 for control group. 1 mg of organic mercury (methyl methylmercuric sulfide: CH3HgSCH3) was given by mouth each day for 10 days (total dose 9–10 mg) to the experimental group. 600 days afterwards the experimental and control rats were killed. Only the peripheral nerves showed changes, small myelinated nerve fibres with thick myelin sheaths in groups. Around these fibres occurred extremely small myelinated nerve fibres and isolated large unmyelinated fibres, and appeared to be regenerated fibres. Destruction of myelin sheaths and cavity formation in the axons were observed in these fibres. The changes in the axons were remarkable at the nodes of Ranvier.
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  • 24
    ISSN: 1432-0533
    Keywords: Ataxia ; Rabbit ; Degeneration ; Cochlear Nuclei ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This hereditary animal ataxia is selective in its sites of involvement within the nervous system, which include principally the central cerebellar, vestibular and cochlear nuclei. Ultrastructural detail has been described for central cerebellar and vestibular nuclei. Herein the cochlear complex of 18 rabbits with this ataxic condition (ax/ax from the strain AX of the Jackson Laboratory) have been examined. The gene is a lethal one, but the animals were used before they became moribund and between 7 and 57 days after the onset of symptoms. By light microscopy nine cell types (Osen, 1969a, b; 1970) have been identified in the cochlear nuclei of the cat. That distribution can also be identified in electron micrographs of rabbit cochlear nuclei, providing there is a singular opportunity to compare cellular vulnerabilities within the ataxic condition, and establish the principal features of associated neuropil alterations. The cochlear nuclei, cerebellar cortex and central nuclei, and the vestibular nuclei, arise from the ependyma of the rhombic lip of the fourth ventricle, making them close allies in their genetic origins. Pathological alterations were evident in scattered neurons from all nuclear sources by 7–15 days following symptom onset. At 15 days the number of altered neurons evident in electronmicrographs had increased markedly, cells becoming involved at a more rapid pace than those already affected could be removed. Much glycogen is evident from 7 days onwards in both neuropil and neurons. It occurs in considerable amounts in astrocytic processes and less abundantly in endbulbs and somata. By 20 to 25 days spongioform changes in neuropil are prominent, and thereafter the extracellular spaces coalesce to produce a lacunar appearance showing little glycogen. It would appear, therefore, that all neuron types, the endbulbs, and the astrocytic processes are markedly involved simultaneously in the spongioform transformation which features this type of ataxia. Involvement of cochlear nuclei only differs in pathological detail from that found at the other involved sites, and the differences seen relate principally to the architectonics of the nuclei, including size and density of the packing of contained elements.
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  • 25
    ISSN: 1432-0533
    Keywords: Hexachlorophene Intoxication ; Toxic Encephalopathy ; Optic Nerve Necrosis ; Cerebral Edema ; Status Spongiosus ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This is the first report of neuropathologic findings following oral ingestion of hexachlorophene in the human. The patient was a 7 year old boy who accidentally ingested 45 ml (approx.) of pHisoHex (hexachlorophene).Toxic reactions included nausea, vomiting, anorexia, diarrhea, decrease in visual acuity, blurred vision blindness, somnolence and disorientation. He developed cardiac arrhythmia, fever, isoelectric EEG and finally respiratory and cardiac arrest 61 h after admission. Autopsy findings showed interstitial myocarditis, pneumonitis and acute bronchiolitis. The brain was edematous. Light microscopy revealed mild diffuse vacuolization of white matter, occasional neuronal degeneration, most prominent on deepest layers of the visual cortex. Disintegration of myelin sheaths and necrosis of axon cylinders were present throughoutoptic pathways. Electron microscopy revealed large, empty extracellular and intramyelinic spaces formed by splitting and separation of the myelin lamellae. These changes are known to occur in experimental animals intoxicated with hexachlorophene, triethyltin, isonicotinic acid hydrazide and cuprizone. However, with respect to hexachlorophene, the localization of lesions to be optic pathways appears to be dependent upon an oral route of administration.
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  • 26
    ISSN: 1432-0533
    Keywords: Oncocytes ; Adenohypophysis ; Pituitary Adenoma ; Secretory Granules ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A light and electron microscopic study was undertaken on 3 surgically removed non-tumorous adenohypophyses and 16 pituitary adenomas. Numerous oncocytes have been found in 2 non-tumorous adenohypophyses and in 6 pituitary adenomas including 1 chromophobe adenoma which was composed almost exclusively of oncocytes. Thus, it seems that the occurrence of oncocytes in the anterior pituitary cannot be considered a rare finding. The distinctive feature of oncocytes is the abundance of mitochondria in their cytoplasm. This alteration can be so extensive that the entire cytoplasm is filled with mitochondria leaving only a small area for the remaining cytoplasmic organelles. Oncocytes arise from adenohypophysial cells. This transformation is gradual and is not restricted to one particular cell type. In the early phases of development of oncocytes the secretory granules are well preserved. Thus, hormone secretion is presumably maintained. It seems conceivable, however, that in the more advanced phases of evolution of oncocytes, when the secretory granules decrease in number, hormone production is diminished or stopped. Further investigations are, however, required to elucidate in detail the functional activity of oncocytes. It remains to be established whether mitochondrial accumulation is principally due to increased formation or delayed breakdown. As some mitochondria show signs indicating division it appears that multiplication of mitochondria is the underlying mechanism resulting in their significant increase. However, the possibility cannot be excluded that the life span of mitochondria is prolonged and mitochondrial longevity plays an important role in causing transformation of adenohypophysiocytes into oncocytes.
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  • 27
    ISSN: 1432-0533
    Keywords: Chronic Nerve Compression ; Median Nerve ; Guinea-Pig ; Electron Microscopy ; Degeneration ; Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In guinea-pigs with chronic median nerve compression at the wrist the electron microscopic changes at level of the lesion and both proximal and distal to it have been studied. At the level of the lesion in animals with prolonged motor latency there was a loss of large myelinated fibres. Remaining large fibres had disproportionately thin myelin sheaths or were demyelinated. Regenerating clusters containing myelinated fibres were present. Evidence of degeneration and regeneration of unmyelinated fibres was present in the more severely affected nerves of this group. Distal to the wrist myelinated fibre density recovered, with regenerating clusters and many axons having disproportionately thin myelin sheaths. Midforearm and upper arm levels were normal. In nerves in which no muscle response to electrical stimulation could be recorded in the palm, a few fibres devoid of myelin remained at the wrist. Immediately proximal to it myelinated fibres were rare, the main feature being Schwann cells containing axons devoid of myelin some of which were degenerating. Degeneration of myelinating fibres within regenerating clusters was seen. At the mid-forearm level large myelinated fibres were reduced and increased numbers of regenerating clusters were seen. Evidence of regeneration of unmyelinated fibres was found. The upper arm was normal.
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  • 28
    ISSN: 1432-0533
    Keywords: Myxopapillary Ependymoma ; Tissue and Organ Culture ; Electron Microscopy ; Basement Membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Explants of a myxopapillary ependymoma were grown on collagen-coated coverslips and in organ culture systems using gelfoam sponge matrices and Millipore filter platforms. The tumor cultured on collagen-coated coverslips initially exhibited the cytologic features of simple uni- and bipolar glial cells and later developed an epithelial-like pattern. Delicate branching of argyrophilic cell processes was demonstrated in Bodian preparations. In organ cultures, the tumor architecture was well preserved for approximately 4 weeks, and mitotic figures were present. Invasion of the sponge foam matrix was seen. Later cultures demonstrated progressive perivascular sclerosis and hyalinization. By electron microscopy, the tumor cells in organ culture systems retained the major fine structural characteristics of the original neoplasm up to 27 daysin vitro. The most striking feature in the late stages was the extensive increase and reduplication of basement membrane material, which appeared related to the increase of collagen fibrils in the extracellular space.
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  • 29
    ISSN: 1432-0533
    Keywords: Progressive Multifocal Leukoencephalopathy ; Hirano Bodies ; Papova Virus ; Paramyxovirus-like ; Nuclear Bodies ; Electron Microscopy ; Neurofibrillary Tangles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have identified three structures that have not previously been reported in electron microscopic examinations of brain from patients with PML: 1. coiled nuclear bodies that may possibly represent tubular paramyxovirus nucleocapsids, 2. Hirano bodies and 3. Neurofibrillary tangles. The paramyxovirus-like material is interesting in view of reports of a transition between nuclear bodies and tubular paramyxovirus nucleocapsids and because of a possible interaction between syncytiogenic paramyxoviruses and Papova viruses in the pathogenesis of SSPE and PML. A study of the Hirano bodies in this case, taken in conjunction with the findings of others leads us to believe that these structures are formed from an overgrowth of neurofilaments. The presence of tangled masses of neurofilaments in the processes of neurons also seen in the present case is consistent with this hypothesis.
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  • 30
    ISSN: 1432-0827
    Keywords: Dentinogenesis ; Diphosphonates ; Calcification ; Collagen ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of high doses of ethylene-1-hydroxy-1,1-diphosphonate (EHDP) were investigated at the light microscopic and subcellular level. The administration of EHDP at a concentration of 7.5–10 mg P/kg body weight/day over a short period of time resulted in complete inhibition of crystal formation in predentin and pre-enamel. An increased predentin width was observed and within newly-formed predentin areas the formation ofcollagen fibrils was grossly disturbed. In addition, fine precipitates appeared in the ground substance. The presence of unusual thread-like elements within specific bodies in the cytoplasm of the odontoblastic processes may be indicative of an interference by EHDP in e.g. the synthesis of precollagen. The possibility of an inhibition by EHDP of the extracellular aggregation of collagen molecules is also discussed. EHDP further inhibited crystal formation within dentinal globules. Functioning ameloblasts were grossly affected in EHDP-treated rats, and it is suggested that this is related to an inhibition of crystal formation in pre-enamel.
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  • 31
    ISSN: 1432-072X
    Keywords: Proteus vulgaris ; Bacteriocin ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The intracellular development of a bacteriocin in a strain of Proteus vulgaris was investigated. Particles which resemble the bacteriocin make their appearance in the cell after 60 min induction with mitomycin C. At this stage they appear as broad bands of tightly-packed phage tail-like structures. With longer periods of induction the bands are disrupted to liberate individual phage tail-like particles.
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  • 32
    ISSN: 1432-072X
    Keywords: Dictyostelium discoideum ; Inorganic Polyphosphate ; Electron Microscopy ; Enzymes ; Polyphosphate Metabolism ; Cellular Slime Mold ; Polyphosphatase ; Polyphosphate-ADP-Phosphotransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The concentration of inorganic polyphosphates in Dictyostelium discoideum was low in the amoebae. A ca 5-fold increase took place during the early stages of multicellular development and was followed by a decrease during the intermediate stages. Electron micrographs showed the presence of electron dense material in all parts of the differentiating cells. The substance was most frequently observed in various types of vacuoles. Two enzymes of polyphosphate metabolism were identified and studied in cell-free extracts: a polyphosphatase and a polyphosphate-ADP-phosphotransferase. No polyphosphate-glucose-phosphotransferase or polyphosphate-AMP-phosphotransferase activities were observed in the extracts. The specific activity of the polyphosphatase, pH optimum 7.6, was ca 30 nmol Pi·min-1·mg protein-1 at all stages of development. The enzyme activity was not inhibited by 0.01 M orthophosphate. The polyphosphate-ADP-phosphotransferase, pH optimum ca 7.7, was studied in the direction of ATP. The enzyme specific activities were very low, about 0.2 nmol P·min-1·mg protein-1, and rather constant during differentiation. The enzyme activity was inhibited by orthophosphate and by excess ADP. It was concluded that the polyphosphate-ADP-phosphotransferase did not contribute significantly to the formation of ATP during multicellular development, and that polyphosphate did not act as a phosphagen in the differentiating cellular slime mold. It was suggested that polyphosphate served as a phosphate store and as a means of regulating the intracellular orthophosphate concentration during development.
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  • 33
    ISSN: 1432-072X
    Keywords: Spirochete ; Artemia ; Brine Shrimp ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. A spirochete which occurs in tissues of the brine shrimp,Artemia salina, was studied by light microscopy and transmission electron microscopy. A total of seven infected shrimps were encountered. 2. Under darkfield illumination, most spirochete cells inArtemia blood were 6–13 μ long and 0.3–0.4 μ wide. Coiling was variable and often irregular. 3. When tissues of the maxillary gland (kidney) and nearby organs were examined by electron microscopy, spirochete cells were found in both extracellular and intracellular locations. These microbes possessed the ultrastructural features typical of members of the Order Spirochaetales: a) a slender protoplasmic cylinder (0.18 μ average diameter), b) axial fibrils (150 A average diameter), and c) an outer envelope or sheath (approximately 75 A thick). 4. Counts made of the number of axial fibrils evident in transverse sections of spirochete cells were consistent with the hypothesis that this spirochete has a 1-2-1 arrangement of axial fibrils. 5. Non-spiral forms were observed in the haemocoel and in the lumen of the maxillary gland.
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  • 34
    ISSN: 1432-072X
    Keywords: Citrate Lyase ; Subunit Structure ; Electron Microscopy ; Reaction Inactivation ; Rhodopseudomonas gelatinosa ; Phototrophic Bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Citrate lyase (EC 4.1.3.6) from Rhodopseudomonas gelatinosa has been purified to homogeneity by protamine sulfate fractionation, chromatography on DEAE-Cellulose and gel filtration. The final enzyme preparation had a specific activity of 138 units per mg of protein and was purified 43-fold over the crude extract. Analysis of citrate lyase by sedimentation equilibrium experiments and gel filtration gave molecular weights of 530000 and 560000, respectively. 2. Electron microscopic investigations of negatively stained enzyme molecules and image analysis showed that citrate lyase is composed of six large and six small subunits; they are arranged in two hexagonal rings lying face to face, each containing, in alternating sequence, three large and three small subunits. The enzyme molecule is 160 Å in diameter and about 100 Å thick. 3. Treatment with sodium dodecylsulfate and mercaptoethanol dissociated citrate lyase into three proteins. Protein III (small subunit) had a molecular weight of 30000 and contained the pantothenate; protein II (large subunit) had a molecular weight of 61000; protein I (M r =97000) was probably an aggregate of II and III. 4. Based on the results obtained a model of citrate lyase was constructed. 5. Purified citrate lyase was obtained from R. gelatinosa in a deacetylated and largely oxidized form. The enzyme was activated by reduction with dithiothreitol (3 mM) and subsequent acetylation with acetic anhydride (1.75 mM). 6. The enzyme was subject to reaction inactivation, the extent of which depended on the concentration of Mg2+.
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  • 35
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    Electronic Resource
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    Archives of microbiology 97 (1974), S. 27-38 
    ISSN: 1432-072X
    Keywords: Mass Mating ; Electron Microscopy ; Cell Fusion ; Membrane Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The process of mating reaction of Saccharomyces cerevisiae was studied by electron microscopy. Prior to the dissolution of the part of the cell walls separating the conjugating pair of cells, the thinning of the electron transparent layer of the cell wall occurs at the part toward which the nuclei are migrating. After the dissolution of the cell walls of the conjugating cells, the cell membranes become associated with each other, then to be broken and rejoined. The first diploid bud emerges from about the middle of the zygote. The morphological changes during the mating reaction are discussed in relation to the biochemical changes so far known.
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  • 36
    ISSN: 1434-4726
    Keywords: Spiral ganglion and Organ of Corti ; Electron Microscopy ; Influence of Different Fixatives and Fixation Methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Ganglion spirale und Cortische Organ des Meerschweinchens wurden nach Osmium- und kombinierter Glutaraldehyd-Osmiumfixation sowie Anwendung verschiedener Fixationsmethoden elektronenmikroskopisch untersucht. Die Strukturen des Cortischen Organs wurden hierbei nicht wesentlich beeinflußt. Am Ganglion spirale ergaben sich Unterschiede im Aufbau der Myelinhüllen der Ganglienzellen. Es wird diskutiert, daß es sich beim semikompakten Myelin um ein Artefakt der Osmiumfixation handelt und daß Glutaraldehyd den Aufbau der Myelinhüllen im Bereich der Spiralganglienzellen naturgetreuer wiedergibt als Osmium.
    Notes: Summary We have been examining with the electron microscope the spiral ganglion and the organ of corti in guinea pigs, using osmium and a combined glutaraldehyde-osmiumfixation together with various fixation techniques. The structures of the organ of corti were not considerably effected. Differences in the structure of the myelin sheets of ganglion cells were found in the spiral ganglion. Presumably the semicompact myelin represents an artefakt after osmium-fixation, glutaraldehyde being able to demonstrate clearer the structure of the myelin sheets on spiral ganglion cells compared to osmium.
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  • 37
    Electronic Resource
    Electronic Resource
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    Cell & tissue research 150 (1974), S. 167-178 
    ISSN: 1432-0878
    Keywords: Pigment cell ; Red hair ; Sunburn ; Man ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pigment cells of human red hair (pheomelanocytes) are never connected to keratinocytes by desmosomes or other defined cell junctions. In the dendritic processes of pheomelanocytes, thin filaments, about 50–80 Å in diameter, and microtubuli can be observed. Early prepheomelanosomes contain loosely arranged filaments. With the onset of pheomelanogenesis dense material is deposited on the filaments. Distinction between late prepheomelanosomes and pheomelanosomes is not clearly possible, because of the disorganized appearance of the content. Furthermore, the content of pheomelanosomes sometimes seems to be disintegrated. By means of the DOPA reaction, tyrosinase activity is shown to be present in: a) prepheomelanosomes, b) large cisternae apposed at one side of dictyosomes, c) small cisternae of the smooth endoplasmic reticulum, and d) coated and uncoated vesicles. The results suggest that red pigment granules are formed in a manner similar to that of melanin granules. It is further assumed that an inadequate stability of pheomelanoprotein accounts for the inability of red-haired people to develop effective protection against ultraviolet light.
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  • 38
    ISSN: 1432-1750
    Keywords: Paraquat Poisoning ; Morphology ; Electron Microscopy ; Light Microscopy ; Letal Course ; Human Lung ; Lung Fibrosis ; Proliferative Alterations ; Degenerative Alterations ; Pathogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphological alterations in the lungs of 3 cases of paraquat intoxication with prolonged lethal course (10, 11, and 25 days) are reported. Combined light-and electronmicroscopic studies reveal that 10 and 11 days after the ingestion of paraquat the endothelium of the occassionally congested capillaries is intact. The basal membranes have only scarce alterations. They are sometimes naked because of shadding of both types of pneumocytes with severe alterations, e.g. lipid accumulation in the cytoplasm. In the vast alveolar edema, red blood cells, some round cells, strands of fibrin, and lamellar cell debris are seen. There are also varying amounts of polymorphnuclear leucocytes and alveolar macrophages with many phagolysosomes and cytosegresomes. Fibroblasts with lipid droplets between the extensive RER form varying amounts of collagen fibrils in the alveolar and sometimes in the very edematous interstitial space. Sometimes surrounded by collagenous material, they thus devoured by macrophages. 25 days after paraquat intoxication a severe alveolar fibrosis, focal interstitial fibrosis, and areas with atelectasis are found. Due to artificial respiration and changed ventilation mechanics, there were large areas with hemorrhage and a honeycomb-like structure of the remaining lung parenchyma. The pathogenesis of the degenerative and proliferative lung alterations is briefly discussed.
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  • 39
    ISSN: 1432-0533
    Keywords: Tissue Culture ; Electron Microscopy ; Enzyme Histochemistry ; Sympathetic Ganglioneuroblastoma ; Medulloblastoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The results of combined tissue culture, ultrastructural and enzyme histochemical investigations carried out on a sympathetic ganglioneuroblastoma are reported.In vitro a vigorous sprouting of newly formed neuritic processes was observed a few days after explantation. The enzymatic reactions for acethylcholinesterase were positivein situ as well asin vitro. The tumor elements showed the ultrastructural characteristics of nerve cells with many microtubuli and filaments, plenty of ribosomes, well developed endoplasmic reticulum. Dense bodies, corresponding to neurosecretion granula (catecholamines) were also observed. Synaptic structures were missing. The results of these investigations confirm that this kind of tumor is different from so-called medulloblastoma.
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  • 40
    ISSN: 1432-0533
    Keywords: Cockayne's Syndrome ; Peripheral Nerve ; Electron Microscopy ; Demyelination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of sural nerve biopsies was studied in two sisters with Cockayne's syndrome. Both had severe physical and mental retardation and evidence of peripheral neuropathy. Striking alterations in the myelin sheath with relative preservation of the axis cylinder were noted in both. There were also electron dense bodies in the Schwann cells. These findings support the suggestion that Cockayne's syndrome may be a form of leukodystrophy.
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  • 41
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Extracellular Fibrils ; Neurologia ; Retina ; New Formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extracellular formation of microfibrils was observed in the cavities of peripheral cystoid degeneration in senile human eyes. The ultrastructure of the fibrils is described and the source of production of the fibrillar material is discussed. It originates most probably from neurological cells, within or surrounding the cysts.
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  • 42
    ISSN: 1432-0533
    Keywords: Tuberous Sclerosis ; Electron Microscopy ; Cerebral Biopsy ; Astrocytes ; Cerebral Tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electron microscopic study of a cortical biopsy from a child presenting a Tuberous Sclerosis shows the importance of the astrocytic gliosis, the existence of abnormal cells of which two types can be recognized, and the presence of giant cells. All these cells are remarkable by the abundance of the ergastoplasm, the development of the Golgi apparatus, and the presence of membrane bound dense bodies. These cells are undoubtedly of astrocytic origin and appear very similar to the cells observed in a tumour of the caudate nucleus of another child affected by the same disease. These morphological data lead to believe that the cerebral abnormalities of the Tuberous Sclerosis essentially concern the astrocytes. The main characteristic of this astrocytic lesion would be its blastomatous potentiality.
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  • 43
    ISSN: 1432-0533
    Keywords: Experimental Neurinoma ; Schwannoma ; Nitrosourea ; Tumor Trausplantation ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Nervous system tumors were induced in the offspring of BD-IX (inbred) and CFE (non-inbred) rats by transplacental administration of ethylnitrosourea. Tumors of the peripheral nervous system (PNS) were obtained in approximately 80% of all animals, and tumors of the central nervous system (CNS) in 16%. Although several peripheral nerves were sites of tumor formation, the trigeminal nerve was the most frequent nerve affected. In male CFE rats, 70% of all PNS tumors affected the trigeminal nerve. The incidence of trigeminal nerve tumors in female BD-IX rats was only 33% of PNS tumors. Light and electron microscopy showed that the PNS tumors are made-up of Schwann cells, and behave like malignant tumors. The tumors began as a proliferation of recognizable Schwann cells, later they lost their basement lamina, destroyed the nerve tissue and invaded neighboring structures, but did not metastasize. Like their human counterparts, they showed “dense” and “loose” areas. In both of these, Schwann cells were recognized as the tumor cells. Trigeminal nerve tumors were transplanted fromin vitro cultured cells or directly from transplanted fresh tumor fragments to isologous rats (BD-IX). Subcutaneous. intraperitoneal and intracerebral transplants were done. The morphology and behavior of the transplanted tumors were similar to the original malignant neurinomas.
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  • 44
    ISSN: 1432-0533
    Keywords: Transneuronal Degeneration ; Olfactory Bulb ; Rabbit ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After peripheral deafferentation of the olfactory bulb of the rabbit obtained either spontaneously by atrophic rhinitis (main bulb only) or surgically, a transneuronal degeneration is observed by light microscopy: narrowing of the outer plexiform layer (30 to 40%), decrease (40%) in mean area of the mitral cells, light texture of the periglomerular neuropil. The study by electron microscopy at survival-times of from 8 h to 6 months shows: 1. intraglomerular dendritic lesions; 2. rarefaction of thick dendrites in the outer plexiform layer; 3. reduction of Nissl bodies in mitral and tufted cells. 4. periglomerular lesions: their morphology and laminar aspect could evoke a vascular origin. The interpretation of these modifications and their relation to transneuronal atrophy are discussed. Dark mitral- or granule cells have been observed neither in the main nor in the accessory olfactory bulbs, even when complete denervation occured.
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  • 45
    ISSN: 1432-0533
    Keywords: Wilson's Hepato-lenticular Degeneration ; Primary Degeneration of Peripheral Nerve ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sural nerve from a patient with'Wilson's hepato-lenticular degeneration was examined by electron microscopy. The myelin sheaths showed remarkable changes and the axons secondary changes, while the unmyelinated nerve fibres were intact. These findings demonstrate that pathological changes of peripheral nerves occur in Wilson's disease. The changes are considered to be primary degeneration of the myelin sheaths.
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  • 46
    ISSN: 1432-0533
    Keywords: Neuronal Inclusions ; Cerebrum ; Cholesterol Inhibitor ; Rat ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intraperitoneal injections of a hypocholesterolemic drug, AY9944 produced neuronal cytoplasmic inclusions in the brain of Wistar strain of rats. The inclusions were numerous and larger in size in the younger age groups but gradually decreased in number and size after 30 days of age. Only a few small inclusions were seen in rats of 35 days of age or older, in spite of continuous injection of the drug. Inclusions gradually decreased in number after discontinuation of the drug in a relatively younger age group. Injection of the drug in adult rats produced only a few small neuronal inclusions. Ultrastructurally, concentrical lamellar structures were the predominant ones in younger age groups but other types of inclusions were seen in older animals and those receiving lesser amounts of the drug or those which were examined after discontinuation of the drug. This observation suggests that morphologically different inclusions can be formed by basically the same treatment if there is any difference in the metabolic activity of the target cell or the amounts of the drug. Biochemical analysis of the sterols revealed a consistently high level of 7-dehydrocholesterol up to 69 days of age, when AY9944 was administered continuously, despite the fact that there was a decrease in the number and size of the abnormal neuronal inclusions.
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  • 47
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    Acta neuropathologica 23 (1973), S. 133-140 
    ISSN: 1432-0533
    Keywords: Metachromatic Leukodystrophy ; Neuronal Inclusions ; Laminated Bodies ; Mucopolysaecharides ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural findings of the metachromatic granules in the anterior horn cells of the spinal cord in a case of metachromatic leukodystrophy are presented. The typical neuronal inclusions are concentrically laminated bodies of approximately 1 μ. In addition various morphological variations of the abnormal inclusions are seen side by side in the same neuron and give the impression that the highly organized laminated bodies are formed as a result of progressive deposition of membranous material upon a nidas which is initially amorphous, which then becomes granular, fibrillar or horizontally striped and finally multilaminated. Material capable of binding colloidal iron particles is demonstrated in these inclusions, and suggests the presence of mucopolysaccharides.
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  • 48
    ISSN: 1432-0533
    Keywords: Chronic Progressive Ophthalmoplegia ; Cerebellar Ataxia ; Electron Microscopy ; Enzyme Histochemistry ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic and enzyme histochemical studies were performed on the cerebellum and the ocular and deltoid muscles from a 38 year old woman who developed bilateral ptosis at the age of nine years. Histologically the cerebellum appeared normal. The biopsies of three ocular muscles showed varying sizes of muscle fibers which were rounded and contained increased numbers of subsarcolemmal nuclei. The deltoid muscle stained by hematoxylin and eosin appeared normal, but the trichrome stain showed increased numbers of red granules within the sarcolemma corresponding ultrastructurally to increased numbers of abnormal mitochondria. These abnormal mitochondria displayed increased reaction products with LDH, NADH and SDH preparations, while the muscle gave normal reaction in phosphorylase, PAS and myosin ATP preparations. Chemical studies on the cerebellum showed normal proteolipids, glycolipids and phospholipids. Ultrastructurally, the cerebellum, the myofibers of three ocular muscles and the deltoid muscle exhibited abnormal mitochondria which showed peculiarly arranged circular cristae. They frequently contained paracrystalline structures which consisted of individual tubules arranged in a helical pattern. Frequently, the abnormal mitochondria were replaced by dense rectangular inclusions and occasionally showed complete transition to crystalline structures.
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  • 49
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    Acta neuropathologica 23 (1973), S. 326-333 
    ISSN: 1432-0533
    Keywords: Hexachlorophene Intoxication ; Cerebral Edema ; Status Spongiosus ; Electron Microscopy ; Myelinopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hexachlorophene intoxication produced cerebral edema in rats and mice characterized by the accumulation of fluid within myelin sheaths. Vessels remained impermeable to Trypan Blue. The amount of water in the brains of affected mice gradually returned to normal when the animals were put back on a normal diet. Correspondingly the status spongiosus decreased in severity in recovering animals. Some axonal degeneration occurred but there was no evidence of any breakdown of myelin lipids. The similarity of this encephalopathy to that seen following intoxication with triethyltin, isonicotinic acid hydrazide and cuprizone is emphasized. The potential toxicity of hexachlorophene to human infants is discussed.
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  • 50
    ISSN: 1432-0533
    Keywords: Subarachnoid Hemorrhage ; Glycerol ; Phenoxybenzamine ; Cerebral Edema ; Prevention ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-four hours and one week, respectively, after subarachnoid hemorrhage (SAH) had been experimentally induced in baboons, therapeutic dosages of glycerol and/or phenoxybenzamine hydrochloride were injected intravenously. Groups of three animals were studied at various time intervals after SAH: one animal served as a control, one animal per group received phenoxybenzamine hydrochloride (PBZ), and thefinal animal received both PBZ and a 10% glycerol (in saline) injection. The animals were prepared for electron microscopy by whole body perfusion with a glutaraldehyde/phosphate fixative. Few ultrastructural abnormalities were noted in cerebral tissue in each of the animals receiving glycerol, whereas the brain tissue from the untreated animals and those which had been treated with PBZ alone showed morphological changes compatible with cerebral edema.
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  • 51
    ISSN: 1432-0533
    Keywords: Dystrophia Myotonica ; Electron Microscopy ; „Fingerprint Inclusions” in Muscle Fibres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary „Fingerprint inclusions” were observed in numerous muscle fibres of 3 cases of dystrophia myotonica studied by electron microscopy in two different laboratories. They consist of parallel or concentric palisades of short electron dense linear elements. Identical „fingerprint inclusions” were reported in two other clinical conditions and cannot therefore be regarded as specific for a particular muscle disease. Their origin and significance remain obscure.
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  • 52
    Electronic Resource
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    Acta neuropathologica 24 (1973), S. 117-127 
    ISSN: 1432-0533
    Keywords: Pinealoma ; Two-Cell Type Pattern ; Electron Microscopy ; Germinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four pinealomas of the two-cell type (atypical teratomas) were investigated by electron microscopy. They all showed the same unique histological ultrastructure. The lymphocyte-like cells did not differ ultrastructurally from lymphocytes. Many plasma cells with well-developed rough surfaced endoplasmic reticulum were also seen. The small cells and the plasma cells were considered to be derived from blood cells. A variety of the large cells in the process of differentiation were observed. They had a large and ovoid nucleus with uniform granular chromatin and contained one or more prominent nucleoli. The large cells had many dilated cytoplasmic cisternae, numerous glycogen granules of about 250–300 Å in diameter and annulate lamellae. Ultrastructurally, the pinealoma of the two-cell type resembled the seminoma of testis which is of germ cell origin. This suggests that the pinealoma may be of germ cell origin.
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  • 53
    ISSN: 1432-0533
    Keywords: Argyria ; Silver Deposition ; Choroid Plexus ; Silver Granules ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 72-year-old woman developed generalized argyria after prolonged intranasal application of a colloidal silver solution. The brain parenchyma, including several infarcts, was free of silver, but the choroid plexus showed silver deposited in the basal lamina, the stroma including calcified bodies, and occasionally within a mesenchymal cell of the choroid plexus stroma. The basal lamina beneath the choroidal epithelium was most affected. The silver granules appeared solid and free of any limiting membrane.
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  • 54
    ISSN: 1432-0533
    Keywords: 6-Aminonicotinamide ; Tissue Culture of Chick Spinal Cord ; Electron Microscopy ; Neurotoxic Effects ; Glucose-6-Phosphate Dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Well myelinated cultures of chick embryo spinal cord were exposed to medium containing 6-aminonicotinamide in a concentration of 0.5 mmol for up to 48 h. By 24–48 h of exposure to the antivitamin, neurons showed a granulovacuolar degeneration which later led to the formation of large vacuoles in the neuronal perikarya. Myelin degeneration was also observed in this period in the form of swelling, beading and ballooning. Electron microscopy revealed moderately swollen mitochondria and dilated endoplasmic reticulum as the earliest neuronal change. Later, neurons became pyknotic and the cytoplasmic organelles disintegrated. Presynaptic endings and glial cells, however, was spared any degenerative change. Intermittent and irregular splitting of myelin lamellae were also observed along the intraperiod lines. Biochemical assay of the glucose-6-phosphate dehydrogenase activity in the experimental cultures showed that 45% of the enzyme activity was lost during the 30-h period. It is concluded that the formation of 6-aminonicotinamide analogues of NAD and NADP coenzymes leads to the impairment of the pentose phosphate pathway and the glucose turnover, and thus produces neurotoxic effects in the central nervous system.
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  • 55
    ISSN: 1432-0533
    Keywords: Minimata Disease ; CNS Degenerative Disorder ; Mercury Poisoning ; Focal Demyelination ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of suspected mercury poisoning (Minamata disease) was studied. Microscopic and ultrastructural changes in the nervous system were compared with those of a confirmed case of mercury poisoning from Minamata Bay, Japan, and those from exprimental animals intoxicated with methyl mercury. Disintegration of the granular layer, disappearance of the Purkinje cells with Bergmann's fiber proliferation and demyelination of the fiber tracts were observed in the cerebellum. Ultrastructural examination also revelad extensive proliferation of astrocytic fibers and characteristic focal demyelination and loosening of the myelin sheaths in many nerve fibers. Such pathological changes were consistent with those observed in both human cases and experimental animals poisoned by methyl mercury.
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  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 24 (1973), S. 273-286 
    ISSN: 1432-0533
    Keywords: Muscle ; Acromegaly ; Histochemistry ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle biopsies from 9 acromegalics were examined by conventional histological and histochemical techniques. Six biopsies were also examined with the electron microscope. Isolated fibre necrosis or vacuolar degeneration was found in 3 biopsies and increased numbers of internal nuclei in 5 biopsies. A high glycogen content was demonstrated in many fibres in each biopsy by the PAS method and by electron microscopy. Routine enzyme histochemical techniques showed hypertrophy of type I and type II fibres in 2 subjects, hypertrophy of type I fibres only in 2 subjects, atrophy of both fibre types in 2 subjects and atrophy of type II fibres only in 4 subjects. Electron microscopy showed large amounts of lipfuscin pigment in many fibres while some fibres had large sarcolemmal nuclei with prominent nucleoli, and a prominent Golgi apparatus. Satellite cells were found in 3 biopsies. In one biopsy coiled membranous configurations thought to consist of phospholipids, and tubular aggregates thought to be derived from degenerating mitochondria were present at the periphery of a number of type II fibres. It is postulated that some of the ultrastructural changes found in muscle fibres are the result of the growth hormone-induced hypertrophic process and the increased turnover of cytoplasmic components associated with it while others reflect the atrophic process in some muscle fibres.
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  • 57
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Myxopapillary Ependymoma ; Basement Membrane ; Filum Terminale ; Collagen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A fine structural study of a myxopapillary ependymoma of the filum terminale confirms and emphasizes the distinctive morphological features of this tumor. Electron basement membrane production were identified. It is suggested that they are related to the growth of ependymal tumor cells in juxtaposition to the collagen normally present in the conus medullaris and filum terminale.
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  • 58
    ISSN: 1432-0533
    Keywords: Nutritional Encephalopathy ; Brain Edema ; Vitamin E Deficiency ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Focal lesions were induced in the cerebellum by feeding chickens a diet high in unsaturated fats and deficient in vitamin E. Ultrastructurally, the lesions consisted of central and peripheral zones. The central zone was characterized in the cortex and white matter by enlargement of the intercellular space, swelling of astrocytes, vacuolization of oligodendrocytes, ballooning of nerve fibers, degenerative changes in small blood vessels, and extravasation of plasma and blood cells. The peripheral zone was characterized by enlargement of the intercellular space in the white matter, swelling of astrocytes in the cortex, and the accumulation of dark bodies in the endothelium of small blood vessels. The results suggest that this nutritional encephalopathy is caused by alterations in the permeability of the vascular bed due to the dietary stress of unsaturated fatty acids in the absence of vitamin E.
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  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 25 (1973), S. 207-219 
    ISSN: 1432-0533
    Keywords: Aujeszky's Disease ; Inoculation ; Virus Particles ; Electron Microscopy ; Neuronal Degeneration ; Demyelination ; Axoplasmic Transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixteen calves were killed at intervals during the course of the disease from 48 h onwards after subcutaneous infection with Aujeszky's disease virus. Ultrastructural changes were evident in the spinal ganglia from 84 h post-inoculation and the intercostal nerves from 96 h post-inoculation. The cytopathic changes in the spinal ganglia consisted of neuronal degeneration, neuronophagia, Schwann cell degeneration and cellular infiltration. The neuronophagic nodule was invariably contained within an intact sheath of satellite cells. Changes in the intercostal nerves were less dramatic but cellular infiltration was frequently seen and occasional Schwann cells were degenerate. In the terminal stages of the disease demyelination was rarely observed. In the ganglion virus was invariably seen in degenerating neurons and occasionally in Schwann cells and monocytes. Satellite cells were rarely infected even when ensheathing an infected neuron. Extra-cellular virus was not observed in ganglia or nerves. Schwann cells and monocytes in the nerves were occasionally infected. Virus particles were seen in the axoplasm both in the ganglion and in the entire length of the nerve. The particles in the axoplasm varied in morphology; thus unenveloped and enveloped particles, and particles in the process of acquiring an envelope were recognised. It was concluded that the neural pathway of Aujeszky's disease virus is probablyvia the axoplasm.
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  • 60
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Encephalomyocarditis (EMC) Virus ; Neurotrophic Viruses ; Viremia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One hundred and eighty 12 week old Swiss mice were injected subcutaneously with 0.1 ml suspensions of the E and M variants of encephalomyocarditis (EMC) virus. Ninety-seven surviving mice were sacrificed at intervals from 24 h to 21 days following injection. The M variant group showed only mild microglial proliferation in the brain, while the E variant group displayed various alterations in the astrocytes and neurons exhibiting loss of nuclear membranes and marked changes in the mitochondria and other organelles. In addition, the neuronal cytoplasm displayed aggregates of fine electron-dense granules on the third day which increased in size during the fifth to seventh day. After 7 days, the neurons contained occasional rhomboid structures composed of rows of parallel arranged granules which were similar to those observed in the viscera after EMC virus infection.
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  • 61
    ISSN: 1432-0533
    Keywords: Earliest Ischaemic Neuronal Change ; Astrocytic Swelling ; Mitochondrial Swelling ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A combined light and electron microscope study was made of the alterations occurring in the neurones and astrocytes of the neocortex and hippocampus of rats killed immediately after intermittent exposures to nitrogen of 5 and 15 min. Blood flow in the right common carotid artery had previously been interrupted by application of an artery clasp which was removed after the exposure to nitrogen and the animals killed by perfusion-fixation with glutaraldehyde. Microvacuolation (MV), the earliest stage of anoxic-ischaemic neuronal damage, was observed in the ipsilateral neocortex and hippocampus of both groups and ischaemic cell change (ICC) bilaterally in the neocortex of animals exposed for 15 min. Ultrastructural examination showed the microvacuoles to be swollen mitochondria. Slightly dense, mildly distorted, non-vacuolated neurones were also seen in the neocortex and hippocampus. They did not exhibit the ultrastructural changes seen in MV and ICC. Swollen astrocytic processes were sometimes seen around the damaged neurones, more frequently after 15 min exposure. Slight swelling of perivascular astrocytic processes was occasionally observed while the extracullular spaces in the neuropil remained unaltered. This implies that the accumulation of fluid in oedematous grey matter is confined to the astrocytic compartment. The reversibility or otherwise of all the neuronal alterations is discussed.
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  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 23 (1973), S. 23-31 
    ISSN: 1432-0533
    Keywords: Chronic Polymyositis ; Virus-Like Particles ; Electron Microscopy ; Paramyxovirus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic examination of a biopsy of skeletal muscle from a young girl with chronic polymyositis revealed the presence of sarcoplasmic and perinuclear inclusions. A large number of virus-like particles was demonstrated at the surface of muscle cells and in extracellular space. On the basis of the microscopic appearance it is suggested that the virus particles belong to one of the members of the paramyxovirus group.
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  • 63
    ISSN: 1432-0533
    Keywords: Cerebral Ischaemia ; Recirculation ; Enzyme Histochemistry ; Electron Microscopy ; Dendrite Swelling ; Pinocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Complete cerebral ischaemia of 30 and 90 min was produced in normothermic barbiturized cats by clamping the innominate and subclavian arteries and lowering the systemic blood pressure. When the brains were adequatly recirculated after 30 min of ischaemia, electron microscopical and histochemical changes observed at the end of the circulatory arrest, were almost fully reversible. Endothelial cells of capillaries showed increased number and size of pinocytotic vesicles and numerous intraluminal flaps. ATPase activity was increased in the capillary walls and glial cells. Opposite to this, severe and irreversible ultrastructural changes were observed after 90 min of ischaemia, and all the enzyme activities studied were sharply decreased.
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