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  • 2000-2004  (21)
  • 1965-1969  (15)
  • 1950-1954
  • 1920-1924
  • 2000  (21)
  • 1968  (15)
  • Electron microscopy
  • 1
    ISSN: 1433-0458
    Keywords: Schlüsselwörter Obstruktives Schlafapnoesyndrom ; nCPAP Therapie ; Nasenschleimhaut ; Elektronenmikroskopie ; Keywords Obstructive sleep apnea ; nCPAP-therapy ; Nasal mucosa ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Background and objective. The treatment success of nCPAP therapy (nasal continuous positive airway pressure) depends partly on the relief of symptoms and partly on long-term patient acceptance and the related avoidance of complications.Nasal complaints constitute the most frequently reported side effects and, together with problems of mask application, are among the primary factors causing an nCPAP-therapy to be prematurely discontinued. Patients/Methods. To assess the morphological changes of the nasal mucosa during nCPAP-therapy, we excised specimens of nasal mucosa tissue in twelve patients with obstructive sleep apnea syndrome (OSAS) both before and 3–10 months after establishing nCPAP-mask acceptance. The specimens were examined by electron microscopy. Results. In all these patients, acceptance of the CPAP mask marked the initial part of therapy. In addition, mucociliary clearance was assessed by the saccharin test before and after therapy. In all patients, the nasal epithelium underwent fundamental changes upon CPAP therapy, which became manifest as modifications in the shape of epithelial cells, conglutination and clumping of the microvilli, and the appearance of immunocompetent cells. Once patients were nCPAP mask compliant, mucociliary clearance was distinctly prolonged in all cases. Conclusions. A successful therapeutic concept should provide normalization of room temperature and air humidity once nCPAP mask compliance has been achieved, and include regular assessment of the condition of the mucosa in the upper respiratory tract. Only by these measures can nasal complications be countered or therapy be applied at an early stage.
    Notes: Zusammenfassung Hintergrund und Fragestellung. Der Therapieerfolg einer nCPAP-Therapie (“nasal continuous positive airway pressure”) ist einerseits abhängig von der Linderung der Beschwerden und andererseits von der Langzeitakzeptanz und der hiermit verbundenen Vermeidung von Komplikationen. Nasale Beschwerden sind die häufigsten Nebenwirkungen und neben den Maskenproblemen die wichtigste Ursache, weshalb eine nCPAP-Therapie frühzeitig unterbrochen wird. Patienten/Methodik. Wir haben bei 12 Patienten mit einem obstruktivem Schlafapnoesyndrom Probeexzisionen aus der Nasenschleimhaut vor und 3–10 Monate nach Anpasssung der nCPAP-Maske entnommen und elektronenmikroskopisch untersucht. Bei all diesen Patienten war die Anpassung der nCPAP-Maske die Ersttherapie. Darüber hinaus wurde vor und nach der Therapie die mukoziliäre Clearance mit Hilfe des Saccharintests beurteilt. Ergebnisse. Bei allen Patienten kam es nach der nCPAP-Therapie zur grundlegenden Veränderungen des Nasenepithels mit Veränderung der Epithelzellenform, Verklebungen und Verklumpungen der Mikrovilli und auftreten von immunkompetenten Zellen. In allen Fällen war die mukoziliäre Clearance nach Anpassung der nCPAP-Maske deutlich verlängert. Schlussfolgerungen. Ein erfolgreiches Therapiekonzept sollte die Normalisierung der Raumtemperatur und Luftfeuchtigkeit gleich nach der Anpassung der nCPAP-Maske und die regelmäßige Beurteilung der Schleimhautverhältnisse der oberen Atemwege beinhalten. Nur somit können nasale Komplikationen aufgehalten oder frühzeitig therapiert werden.
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  • 2
    ISSN: 1437-773X
    Keywords: Key words Pigmented purpuric dermatitis ; Endothelial cell ; Fibrous long-spacing collagen ; Intracellular structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of pigmented purpuric dermatitis (PPD) in a Japanese man aged 59 years is reported with an interesting ultrastructural finding. Clinically, the lesions, which consisted of telangiectatic puncta and pigmentation, were irregular in shape and occurred predominantly on the lower legs without pruritus. Histologically, lymphocytic perivascular infiltrates and extravasation of red blood cells were observed in the papillary dermis. Ultrastructurally, endothelial cells with ovoid nuclei showed swelling and the lumen of the capillary became narrowed. Several banded structures, so-called fibrous long-spacing collagen (FLSC), were observed in the cytoplasm. They were spindle shaped, about 5 μm in length, and showed crossbands of 300-nm-wide intervals with fine intraperiodic bands. These structures were not observed in dermal connective tissue and fibroblasts. These results suggested that FLSC was synthesized in endothelial cells rather than being phagocytosed by endothelial cells, which might be helpful in investigating the etiology of PPD.
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  • 3
    ISSN: 1437-773X
    Keywords: Key words Dental titanium implant ; Electron microscopy ; X-ray microanalysis ; Electron diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study investigated the tissue response associated with dental titanium implants. The mandibular third and fourth premolars and first molar of three adult beagle dogs were extracted bilaterally. Healing was then allowed for 3 months. Six titanium implants were placed in the mandibles of a dog. Three weeks after the implantation, mandibular sections containing the implants were retrieved with the use of a bone saw and investigated by light and electron microscopy, X-ray microanalyzer, and electron diffraction. Scanning electron microscopic observation showed titanium particles on the implant–bone interface, and investigation by microanalyzer revealed titanium not only on the implant–bone interface but also in the bone tissue. Transmission electron microscopic observation and investigation by electron diffraction showed titanium in the bone matrix and cells other than macrophages. In this study, titanium particles from the dental implant were recognized morphologically in the surrounding bone tissue. Thus, study of the influence of titanium particles on the human body is needed.
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  • 4
    ISSN: 1432-2161
    Keywords: Keywords Ectopic calcification ; Deep posterior compartment syndrome ; Computed tomography ; Carbonate-containing apatite ; Electron microscopy ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We present a patient whose ectopic calcification following deep posterior compartment syndrome was studied by electron microscopy, chemical analyses, and X-ray diffraction. The patient complained of a toe flexion deformity following a tibial fracture which he sustained 18 years earlier. Damage to the peroneal artery was demonstrated by magnetic resonance angiography, suggesting that the patient had had deep posterior compartment syndro-me in the past. A large radiopaque mass, identified in the flexor hallucis longus muscle by radiographs and computed tomography, was resected, resulting in a dramatic improvement of the toe deformity. The resected material was analyzed in detail. It included no osseous tissue, and was not birefringent under a polarizing microscope, being compatible with ectopic calcification rather than ossification. On electron microscopy the material was found to be an assembly of tiny rods. Chemical and X-ray diffraction analyses suggested a carbonate-containing apatite as the most probable substance.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 99 (2000), S. 525-528 
    ISSN: 1432-0533
    Keywords: Key words Tubulovesicular particles ; Scrapie ; Electron microscopy ; Prion protein ; Transmissible ¶spongiform encephalopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Tubulovesicular bodies are structures, apparently specific to the transmissible spongiform encephalopathies, which are of unknown composition and significance. Prion protein (PrP) is absent from tubulovesicular bodies when tissues are examined by immunogold electron microscopy. In the F1 cross of C57 and VM mice (CVF1) infected with ME7 scrapie there is a marked degeneration of hippocampal CA1 neurons. In this model the earliest changes seen, at about 100 days post inoculation (dpi) are a degeneration of axon terminals and synaptic loss. Terminal disease is around 250 dpi. In blind coded trials we counted the number of tubulovesicular particles and estimated their density in 56–76 electron micrographs taken from the stratum radiatum of each of one or two CVF1 ME7-infected mice at 84, 100, 126, 154 and 181 dpi and from four normal brain inoculated control mice. Tubulovesicular particles were present from 98 dpi and the density of particles increased with increasing incubation period. The very early occurrence of tubulovesicular particles, before the presence of significant pathology, argues that tubulovesicular particles are a part of the primary disease and are not epiphenomena.
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  • 6
    ISSN: 1432-0533
    Keywords: Key words Papillary ; Glioneuronal tumour ; Electron microscopy ; NCAM ; L1 adhesion molecule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Among the mixed glioneuronal tumours, a new variant called papillary glioneuronal tumour has recently been delineated. A case occurring in a 23-year-old man is reported. The tumour was cystic with a mural nodule enhanced by gadolinium injection. It was located within the left parieto-occipital lobe. Surgical excision showed a greyish friable tumour with cystic areas. Histopathological examination revealed a pseudopapillary component comprising a single layer of regular cells, arranged around hyalinised vessels. These cells were immunoreactive with anti-glial fibrillary acidic protein and HNK1 antibodies. A neurocytoma-like component coexisted with round blind cells and focal fibrillary rosettes. These cells were immunostained by anti-neuron-specific enolase and anti-synaptophysin antibodies. Neither mitoses nor ganglioid cells were seen. HNK1, the three isoforms of NCAM, and the L1 adhesion molecule were detected by Western blot analysis. Ultrastructural study showed three different types of cells. The first contained gliofilaments, the second showed long processes with true synapses, and the third was poorly differentiated. However, all had identical nuclei and contained dense bodies. These findings suggest a common origin for the tumour cells derived from a bipotential neuroglial progenitor. As for other mature mixed neuroglial tumours, the prognosis is good. Our patient is free of disease 7 years after complete surgical treatment.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 99 (2000), S. 39-47 
    ISSN: 1432-0533
    Keywords: Key words Sural nerve ; Muscle fiber diameter ; Morphometry ; Electron microscopy ; Myotonic ¶dystrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We compared peripheral nerve fibers and muscle fibers in myotonic dystrophy (MD) using a computer-assisted device for morphometry. In the 17 cases with MD studied, the sural nerves of 14 cases (82%) showed various degrees of reduction of the myelin sheath area (MSA) per endoneurial area. Of these, 8 cases (47%) presented with a mild reduction of the MSA, 5 cases (29.4%) with moderate reduction, and one case (6%) with severe reduction. The number of myelinated nerve fibers was not significantly reduced in MD when compared with control nerves, due to clusters of small regenerated nerve fibers. The mean diameter of the muscle fibers in 6 of the 17 cases was less than 40 μm. Of these 6 severely affected cases, ¶5 revealed a considerable reduction of the MSA. Other cases, which appeared to be normal in respect to the diameter of muscle fibers, showed various degrees of reduction of the MSA. Thus, there is usually, but not always a morphometric correlation of the severity of changes between peripheral nerves and muscle. The severity of the peripheral neuropathy appears to depend largely on the patient’s age, the stage of the disorder, and the time of progression. Electron microscopic examination of sural nerves showed significant, though non-specific pathological changes.
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  • 8
    ISSN: 1432-069X
    Keywords: Key words Fluorescence ; Photodynamic therapy ; Bromosulphophthalein ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cellular uptake and subcellular localization of indocyanine green (ICG; absorption band 700– 850 nm), and cell survival and ultrastructural changes following ICG-mediated phototherapy were investigated in vitro in four different cell lines derived from human skin (SCL1 and SCL2 squamous cell carcinoma, HaCaT keratinocytes and N1 fibroblasts). The cellular uptake of ICG (1–50 μM, incubation times 1, 4, 24 h) was saturable, highly cumulative and could be inhibited by the addition of 250 μM bromosulphophthalein indicating the involvement of the organic anion transporting polypeptide (OATP). For HaCaT cells, the maximum cellular uptake (Vmax) and the Michaelis constant (Km) were 9.9 ± 1.1 mM and 47 ± 16 μM, respectively, following a 24-h incubation with ICG. Fluorescence microscopy revealed a cytoplasmic distribution of ICG, probably bound to glutathione S-transferase. Following irradiation with a cw-diode laser (805 nm, 80 mW/cm2) at doses of 24 or 48 J/cm2, the phototoxicity was determined using the MTT assay as a measure of cell viability. For all cell lines, ICG concentrations above 25 μM produced a significant phototoxic effect. The EC50 of ICG for HaCaT cells following irradiation at 24 J/cm2 was 20.1 ± 3.9 μM. Growth curves showed that even HaCaT cells treated at the EC50 were killed within a week following treatment. Electron microscopy 1 h after ICG-mediated phototherapy revealed cytoplasmic vesiculation, dilation of the rough endoplasmic reticulum, the Golgi complex and the perinuclear cisternae and the beginning of chromatin condensation in the nucleus. These ultrastructural findings are not consistent with a photothermal action of ICG-mediated phototherapy. Taken together with those of previous studies by our group these results support photooxidation as a major cell-killing mechanism.
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  • 9
    ISSN: 1432-0568
    Keywords: Key words Pheromone ; Supporting cell ; Vomeronasal organ ; Olfaction ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  To investigate cell turnover in the vomeronasal epithelium we used electron microscopy to obtain quantitative measurements of changes observed at the surface of the sensory epithelium. Receptor cell degeneration was induced by sensory nerve transection and animals were examined at postoperative recovery times of 2, 4, 6, 10, 15, 35 and 60 days. We measured the number and density of receptor and supporting cells, and membrane length at the surface of the sensory epithelium. The number of receptor cells rapidly decreased during the degeneration period, reaching a minimum at 6 days. After 15 days of recovery the number and density of receptor cells returned to control levels. The surface membrane length for regenerated receptor cells was similar to that of controls, however the morphological appearance was characteristic of immature cells. In contrast to the receptor cells, the number and density of supporting cells did not change during degeneration and regeneration. However, there was a significant increase in the length of supporting cell-surface membranes. These results suggest that during receptor cell degeneration, supporting cell membranes compensate for the loss of receptor cells by expanding their surface membrane length to help to maintain the continuity of the epithelial surface. Thus, an important role of vomeronasal supporting cells may be to maintain the structural integrity of the epithelium during turnover of the receptor cell population.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 100 (2000), S. 435-444 
    ISSN: 1432-0533
    Keywords: Key words Muscle transplantation ; Muscle ¶regeneration ; Electron microscopy ; Muscle spindles ; Motor innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Extensor digitorum longus (EDL) muscles from 2- to 28-day-old rats were grafted into EDL muscles of adult inbred recipients (n = 8). At 1–6 months after the operation, experimental muscles were excised and the ultrastructure and innervation of regenerated muscle spindles was examined. Regenerated muscle spindles (n = 36) in isografted EDL muscles contained 4.3 ± 0.2 (mean ± SEM) encapsulated muscle fibres. These “intrafusal” muscle fibres lacked nuclear bag and nuclear chain accumulations, which are characteristic of normal muscle spindles; thus, they rather resembled thin encapsulated extrafusal muscle fibres. In the same sample, myelinated axons were found in 33 (92%) muscle spindles, but no sensory terminals were found. These findings demonstrate that regenerated spindles in isografted EDL muscles were not reinnervated by spindle-specific sensory axons, but exclusively by motor axons. Typical intracapsular motor endplates (MEPs) were found in one third of regenerated spindles examined. Their motor terminals contained accumulated mitochondria and synaptic vesicles. As is characteristic for MEPs, axolemma and sarcolemma were separated by a synaptic cleft about 60 nm wide that contained a basal lamina. The underlying sarcolemma formed either small infoldings or none at all, and the subsynaptic area contained only small subsarcolemmal accumulations of mitochondria. It is apparent that the structures described here as “regenerated muscle spindles” do not perform their normal physiological function as stretch receptors because they lack the sensory innervation. The present results show that regeneration and reinnervation in heterochronous isografts corresponds to that previously described in autotransplanted free muscle grafts. The results also show that, during muscle spindle regeneration, intrafusal satellite cells develop into extrafusal-like muscle fibres, apparently due to their motor innervation.
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  • 11
    ISSN: 1432-2021
    Keywords: Key words Cristobalite ; Tridymite ; Phase transformation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract Using minimum exposure techniques, it is feasible to perform high resolution electron microscopy on the α-cristobalite phase of (Si0.9 Ge0.1)O2, which is extremely radiation sensitive. Such images reveal atomic scale information of twins and tridymite-like stacking faults on (1 1 1)β planes, as well as of domain boundaries resulting from the β→α transition. Polytype structures are formed in certain cases. Morphological features suggest that the phase transformation cristobalite → tridymite proceeds by means of a zonal dislocation mediated synchro-shear process on (1 1 1)β planes; the geometry of this process is analyzed.
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  • 12
    ISSN: 1432-1017
    Keywords: Key words X-ray crystallography ; Electron microscopy ; Biological databases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Advances in structural biology are opening greater opportunities for understanding biological structures from the cellular to the atomic level. Particularly promising are the links that can be established between the information provided by electron microscopy and the atomic structures derived from X-ray crystallography and nuclear magnetic resonance spectroscopy. Combining such different kinds of structural data can result in novel biological information on the interaction of biomolecules in large supramolecular assemblies. As a consequence, the need to develop new databases in the field of structural biology that allow for an integrated access to data from all the experimental techniques is becoming critical. Pilot studies performed in recent years have already established a solid background as far as the basic information that an integrated macromolecular structure database should contain, as well as the basic principles for integration. These efforts started in the context of the BioImage project, and resulted in a first complete database prototype that provided a versatile platform for the linking of atomic models or X-ray diffraction data with electron microscopy information. Analysis of the requirements needed to combine data at different levels of resolution have resulted in sets of specifications that make possible the integration of all these different types in the context of a web environment. The case of a structural study linking electron microscopy and X-ray data, which is already contained within the BioImage data base and in the Protein Data Bank, is used here to illustrate the current approach, while a general discussion highlights the urgent need for integrated databases.
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  • 13
    ISSN: 1432-2307
    Keywords: Key words Gastrointestinal pacemaker cell tumor ; Interstitial cells of Cajal ; Gastrointestinal autonomic nerve tumor ; c-kit Receptor-antibody ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Recent studies indicate that a subgroup of gastrointestinal stromal tumors, including gastrointestinal autonomic nerve tumors (GANTs), originate from stem cells that differentiate toward a pacemaker-cell phenotype. These pacemaker cells form a complex network intercalated between the autonomic nerves and the muscle walls of the gastrointestinal tract and are called interstitial cells of Cajal (ICC). The c-kit receptor (CD117) is a sensitive marker for ICC. The aim of our study was to support the hypothesis that GANTs show ICC differentiation. Seven GANTs without convincing smooth muscle or neural differentiation all showed homogeneous reactivity for the c-kit receptor. CD34 was positive in three cases. On electron microscopy, the typical features of GANT were present. Six tumors contained skeinoid fibers. Most tumors were related to the small bowel. They presented as single (two cases) or multiple (five cases) tumors. The presenting symptoms were abdominal bleeding (2), abdominal mass (2), anemia (1), and small-bowel perforation (1). In two cases, liver metastases developed. Because of the close immunohistochemical and electron microscopic similarities of these tumors to the interstitial cells of Cajal, the term gastrointestinal pacemaker cell tumor seems appropriate.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 436 (2000), S. 560-566 
    ISSN: 1432-2307
    Keywords: Key words M cell ; HRP ; Nasopharyngeal lymphoid tissue ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The nasopharyngeal tonsils (adenoids) are prominent components of human nasal-associated lymphoid tissues (NALT). However, the role of the nasopharyngeal tonsils in antigen uptake for initiation of the mucosal immune response is unknown. The aims of this study were to describe the ultrastructure and function of the M cells of the human nasopharyngeal tonsils and to clarify their capacity for antigen uptake. Tissues obtained from eight patients undergoing adenectomy were examined by light and electron microscopy. Lymphoepithelium covers the nasopharyngeal lymphoid tissue and consists of ciliary epithelium, non-ciliary epithelial cells, M cells, goblet cells, and many intraepithelial lymphoid cells. M cells have irregular and broad cytoplasm-containing microvilli on their surface and small vesicles in their cytoplasm. Many lymphoid cells were enfolded by M cells. The uptake of horseradish peroxidase (HRP) in the tissue in organ culture was studied using histochemical techniques. Excised adenoid tissue was incubated in RPMI 1640 culture media with HRP for 10, 30, and 60 min. HRP which had adhered to the surface was taken up in vesicles and then transported in vesicles and tubules by M cells. The M cells of nasopharyngeal lymphoid tissue were ultrastructurally and functionally similar to those in human Peyer’s patches and colonic lymphoid follicles. These findings indicate that NALT bears similarities to the gut-associated lymphoid tissue, and its antigen uptake capacity may be important for initiation of immunity in the upper aerodigestive tract.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 436 (2000), S. 628-633 
    ISSN: 1432-2307
    Keywords: Key words Prostate adenocarcinoma ; Endocrine cells ; Immunohistochemistry ; FSH ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We report an unusual variant of prostatic adenocarcinoma with marked endocrine differentiation (mixed endocrine-exocrine adenocarcinoma). Endocrine cells accounted for 60% of the tumour cells, were positive with silver impregnation and for chromogranin A, synaptophysin, and neuron-specific enolase, and coexpressed the exocrine antigens prostatic acid phosphatase and prostatic-specific antigen. Most of the endocrine cells were basophilic with haematoxylin-eosin and proved immunoreactive for alpha subunit of human chorionic gonadotropin and follicle-stimulating hormone. The remaining endocrine cells were represented by eosinophilic cells positive for serotonin, and by calcitonin and serotonin-immunoreactive cells not identifiable in haematoxylin-eosin-stained sections. On ultrastructural analysis, two types of endocrine cells were identified. The most frequent cell type showed abundant cytoplasmic round, electron-dense neurosecretory granules, either small (212±44 nm) or large (471±114 nm), resembling those of gonadotropic pituitary cells. The second type of endocrine cells contained irregular electron-dense granules similar to those of serotonin-storing enterochromaffin cells.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Physics and chemistry of minerals 27 (2000), S. 480-494 
    ISSN: 1432-2021
    Keywords: Key words Olivine ; Grain boundary ; Partial melt ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract The microstructure of olivine-olivine grain boundaries has been studied in experimentally deformed (1200–1227 °C, 300 MPa) partially molten olivine and olivine-orthopyroxene rocks. In-situ melting produced ∼1 vol% melt in all samples studied. Grain boundary analyses were carried out using a number of transmission electron microscopy techniques. The grain boundary chemistry in undeformed olivine-orthopyroxene starting material showed evidence for the presence of an intergranular phase along some, but not all, of the olivine-olivine boundaries. In the deformed samples, ultrathin Si-rich, Al- and Ca-bearing amorphous films have been observed along all investigated olivine-olivine grain boundaries. The chemistry of the grain boundaries, which is considered to be indicative for the presence of a thin film, was measured with energy-dispersive X-ray spectroscopy (EDX) and energy-filtering imaging. The amorphous nature of the films was confirmed with diffuse dark field imaging, Fresnel fringe imaging, and high-resolution electron microscopy. The films range in thickness from 0.6 to 3.0 nm, and EDX analyses show that the presence of Al and Ca is restricted to this ultrathin film along the grain boundaries. Because thin melt films have been observed in all the samples, they are thought to be stable features of the melt microstructure in deformed partially molten rocks. The transition from the occasional presence of films in the undeformed starting material to the general occurrence of the films in deformed materials suggests that deformation promotes the formation and distribution of the films. Alternatively, hot-pressing may be too short for films to develop along all grain boundaries. A difference in creep strength between the studied samples could not be attributed to grain boundary melt films, as these have been found in all deformed samples. However, a weakening effect of grain boundary melt films on olivine rheology could not be ruled out due to the lack of confirmed melt-film free experiments.
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  • 17
    ISSN: 1619-0904
    Keywords: Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC) ; In vivo biocompatibility ; Artificial endocrine pancreas ; Electron microscopy ; Glucose sensor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Biocompatibility is important to assure a mild body reaction to an implanted device and its long-term stability and functionality. In diabetes research, subcutaneously implanted glucose monitoring systems need biocompatible surfaces for long-term application. The biocompatibility of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC), a material similar to the phospholipid layer of a cell membrane, was compared in vivo with the biocompatibility of polyurethane (PU), polyvinyl alcohol (PVA), and cuprophane (CUP). Needle-type glucose sensors and hollow-fiber probes used for microdialysis were coated with these four different biomaterials and implanted subcutaneously in 18 rats and 7 healthy volunteers. At set intervals, the implants and, in the case of the rats, also the surrounding tissue were removed and characterized by light and electron microscopy. MPC-coated sensors and hollow-fiber probes showed smooth and thin deposits in flat layers, whereas the surface deposits on PU- and PVA-coated sensors and those on CUP hollow-fiber probes appeared as rough, irregular, and dense attachments of aggregated cells and protein. This study confirmed results from earlier in vitro tests by showing the biocompatibility and reliability of MPC. Even though the amount of protein and cells attached to the MPC surface was not as low as expected from in vitro experiments, the biocompatibility and long-term stability of the implanted devices were superior to those of PU, PVA, and CUP.
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  • 18
    ISSN: 1615-6102
    Keywords: Electron microscopy ; Photoreceptor ; Visual membrane ; Photic radiation damage ; Retina ; Crustacea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Visual membranes of the crayfish eye either belong to the small, distally placed rhabdomere of retinula cell R8 or are part of the much more voluminous proximal rhabdom, made up of rhabdomeres belonging to cells R1–R7. Under various conditions of environmental stress (e.g., prolonged darkness, elevated temperature, bright light with and without a concomitant rise in temperature, flickering lights) the visual membranes of R8 prove far more resistant to structural damage than those of R1–R7. Membrane damage is known to occur when dormant lipoxygenases become activated, for example through heat. Since R8 is the only type of visual cell in the crayfish retina that does not contain grains of screening pigment, the view that screening-pigment granules could “aggravate” or even “trigger” membrane damage in times of stress is strengthened. Functionally, R8's strong resistance to physical damage when exposed to flickering lights points to a role of the distal rhabdom in the movement detection system of the crayfish eye.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Brain tumor pathology 17 (2000), S. 153-157 
    ISSN: 1861-387X
    Keywords: Chordoid meningioma ; Castleman syndrome ; Electron microscopy ; Immunohistochemistry ; Magnetic resonance image
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Chordoid meningioma is a relatively rare variant that is often associated with peritumoral lymphoplasmacellular infiltration causing Castleman syndrome (CS). We present a 44-year-old woman with chordoid meningioma not associated with CS. The patient presented with epilepsy and right hemiparesis (Todd's palsy) on admission. The radiological findings revealed an extraaxial mass lesion in the premotor cortex. They were compatible with a preoperative diagnosis of meningioma. No physical abnormalities related to CS were detected. A left frontal craniotomy was performed. The tumor surface was gelatinous, and it was totally resected with the attached dura mater (Simpson grade I). The patient had an uneventful recovery, and her seizures subsided. The pathological findings of the specimens revealed nests and cords of spindle and epithelioid cells with abundant myxoid matrix, mimicking the features of chordoma. On the basis of radiological, immunohistochemical, and electron microscopic findings, chordoid meningioma was verified, and a review of the literature was performed.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Neurological sciences 21 (2000), S. S63 
    ISSN: 1590-3478
    Keywords: Key words NCLs ; Peripheral biopsies ; Brain biopsy ; Blood lymphocytes ; Electron microscopy ; Pathological cytosomes ; Diagnostic criteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clinical findings and pathological features of 28 patients affected with neuronal ceroid lipofuscinoses (NCL) are reviewed. The patient group included 15 children affected with the late-infantile form of NCL (LINCL), 10 patients affected with the juvenile form (JNCL), and 3 adult cases. Ultrastructural examinations of 50 biopsies from 6 tissues were consistent with clinical features in all LINCL and JNCL cases but one. The importance of electron microscopic (EM) examination of blood lymphocytes in these forms is outlined, particularly when combined with molecular analysis of the CLN2 or CLN3 genes, respectively. This approach leads to a definite diagnosis of LINCL and JNCL is a relatively short time. In adult NCL, diagnosis still relies on pathological grounds, and difficulties in interpreting the osmiophilic storage bodies in different tissues are outlined. EM investigation of blood lymphocytes was not helpful in any case of adult NCL. Results of one stereotactic brain biopsy are also reported.
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  • 21
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    Journal of orthopaedics and traumatology 1 (2000), S. 11-16 
    ISSN: 1590-9999
    Keywords: Key words Hydroxyapatite ; Bone ; Interface ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed a back-scattered electron microscopy analysis of the interface between newly formed bone and hydroxyapatite coating, in an experimental rabbit model. Twenty cylinders made of Ti6A14V and coated with hydroxyapatite at different crystallinity were implanted in the distal femural canal and retrieved at 4, 8, 26 an 34 weeks. Crystallinity of the coating varied from 90% to 60% and thickness varied between 50 and 100 μm. Osteocytes were detectable a few micrometers in proximity of the coating. They produced new bone which was so tightly apposed to the coating that high magnification BSEM did not resolve any discontinuity at the interface. This was not observed in uncoated implants. Degradation of the hydroxyapatite coating is not a simple hydrolytic process because newly formed bone is remodelled in areas were a tight apposition with hydroxyapatite is present. The coatint itself is likely to be attacked by the resorptive action of multinucleated giant cells and osteoclasts. In conclusion, response to coated samples is morphologically characterized by tight apposition with bone. The substitution of areas of the coating by newly formed bone is possible.
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  • 22
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    Anatomy and embryology 127 (1968), S. 154-164 
    ISSN: 1432-0568
    Keywords: Collagen ; Connective tissue ; Electron microscopy ; Polarization microscopy ; Tendons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The correlation of the mechanical properties and the morphological behaviour of collagenous tissue during strain was investigated. Relaxed and strained tendons were examined by incidental and transmitted polarized light microscopy and electron microscopy. It was concluded that the wavy pattern seen at the seminicroscopic level of the collagen fibers vanished at relatively low loads. The direction of birefringence in transmitted light microscopy varied in the relaxed preparations but became even in the strained. The electron microscopy showed that the fibrils had the same periodicity as calculated from X-ray diffraction patterns of moist collagen, i.e. 680 Å, and that straining increased the period lengths of some fibrils. The correlation of these findings to a mechanical analogy of the tissue was discussed.
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  • 23
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Skeletal muscle ; Ring fibers (Ringbinden) ; Sarcoplasmic masses ; Sarcomere fragmentation ; Myofilaments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Dans diverses conditions habituellement pathologiques, la fibre musculaire peut comporter une zone périphérique nettement individualisée et contenant des formations filamentaires dont la disposition spatiale est anormale. Les auteurs analysent les aspects ultrastructuraux de trois types de telles formations filamentaires périphériques: 1. lesfibrilles annulaires, bien visibles en microscopie optique; la microscopie électronique permet d'établir leur structure myofibrillaire normale, la fréquence des aspects complexes d'entretissage entre ces myofibrilles et les myofibrilles de disposition longitudinale; 2. lesmasses latérales dites “sarcoplasmiques” en microscopie optique, dont l'analyse en microscopie électronique permet d'établir la richesse fréquente en formations myofilamentaires disposées de façon anarchique; 3. lesempilements de fragments de sarcomère selon les différents plans de l'espace, qui ne peuvent être mis en évidence en microscopie optique, et n'apparaissent clairement qu'en microscopie électronique. L'étude ultrastructurale permet de récuser le caractère artificiel de ces différents aspects, souvent envisagé en microscopie optique, d'insister sur le caractère topographique limité le plus souvent à la périphérie de la fibre de telles altérations, et sur la fréquence de l'association de ces différentes anomalies entre elles. Cette étude apporte en outre des arguments en faveur de la nature dégénérative de ces aspects. Ces anomalies ne sont spécifiques d'aucune affection musculaire particulière, mais les auteurs les ont rencontrées cependant avec un maximum de fréquence dans les dystrophies musculaires progressives.
    Notes: Summary In various—usually pathologic—conditions the muscle fibre may show a distinct peripheral zone containing abnormally arranged filamentous formations. The authors have analysed the ultrastructural aspects of three types of such peripheral filamentous formations: 1.ring-shaped fibrils clearly visible under the light microscope; in these cases the electron microscope reveals their normal myofibrillar structure as well as the high incidence of complex formations resulting from the intertwining of such myofibrils and longitudinally disposed ones; 2. so-called“sarcoplasmic” lateral masses under light microscopy; in these cases the electron microscope shows a wealth of irregularly disposed myofilamentous formations; and 3.accumulations of sarcomere fragments at different spatial levels, which may be distinguished only under the electron microscope but not by light microscopy. The ultrastructural study permits the authors to disprove the artificial character of these different aspects—an assumption frequently made on the basis of light-microscopic findings—, to insist on the fact that such alterations are mostly limited topographically to the periphery of the fibre, and to stress that these different anomalies are often associated with one another. The study has furthermore furnished considerable evidence in favour of the degenerative nature of the forms under consideration. The anomalies in question are not specific to any one muscular affection; however they have been found most frequently in progressive muscular dystrophy.
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  • 24
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    Acta neuropathologica 10 (1968), S. 336-346 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Rat brain, new born ; Porencephalic cyst ; Brain injury ; Glial reactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Stichverletzung des Gehirns neugeborener Ratten erzeugte regelmäßig eine Defekthöhle, deren Begrenzung zuerst aus einer Schicht fibrillärer Astrocyten mit vielen dünnen Cytoplasmafortsätzen bestand. Während der 2. und 3. Woche wurde die Astrocytenschicht lockerer und durch eine Basalmembran abgegrenzt, die gewöhnlich in Verbindung mit einer darüberliegenden Schicht von Pia-ähnlichen Zellen stand, Erst hernach ähnelte die Feinstruktur der Defektwand jener der Heldschen “Membrana gliae accessoria” für die differenzierte Struktur vorbehalten bleiben und nicht zur Bezeichung der frühen Astrocytenbegrenzung verwendet werden sollte. Keine dichte Glia-oder Bindegewebsnarbe, wie im Erwachsenengehirn üblich, wurde gefunden. Die Makrophagen verschwinden vor der 3. Woche, anstelle monatelang wie beim Erwachsenen zu verweilen. Das Vorhandensein oder Fehlen von Narbenbildung und Makrophagen dürfte nur das Alter, in dem die Verletzung erfolgte, widerspiegeln und daher für die Unterscheidung zwischen Mißbildungs-und Verletzungsdefekten unverläßlich sein.
    Notes: Summary Needle injury of the newborn rat brain resulted regularly in cavity formation, the lining of which at first consisted of a layer of fibrous astrocytes with many thin cytoplasmic projections. Between the second and third weeks the astrocytic surface became smoother and was lined by a basement membrane, usually in association with an overlying layer of pia-like cells. Only after this time did the fine structure of the cavity wall resemble that of Held's membrana gliae limitans superficialis. It is, therefore, suggested that Spatz's “membrana gliae limitans accessoria” be reserved for this differentiated structure and not used to identify the earlier astrocytic lining. No dense glial or connective tissue scarring, as usually seen in the adult brain, was found. Macrophages disappear before the third week, rather than persisting for months, as in the adult. The presence or absence of scar formation and macrophages may only reflect the age at which the injury occurred and may, therefore, be unreliable in distinguishing between cavities due to malformation and to injury.
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  • 25
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    Acta neuropathologica 10 (1968), S. 17-25 
    ISSN: 1432-0533
    Keywords: Myelinated CNS axons ; Axoplasm ; Tubular structures ; Axonal reactive changes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine honigwabenartige tubuläre Anordnung wurde in stark myelinisierten Axonen gefunden. Sie wurde im Kleinhirn einer offenbar gesunden Ratte und eines Schimpansen mit Kuru-ähnlichen Symptomen beobachtet. Sie fand sich ferner in der Großhirnrnde einer Maus mit einem intracerebralen Tumorimplantat. Eine verbindliche Ursache konnte nicht aufgedeckt werden. Es wird jedoch angenommen, daß diese Struktur eine spezifische axonale Reaktion auf eine mögliche Vielfalt von noch unbekannten Bedingungen entspricht.
    Notes: Summary A honeycomb-like tubular array was observed in heavily myelinated axons. It was observed in the cerebellum of an apparently normal rat and a chimpanzee with “Kurulike” symptoms. It was also found in the cerebral cortex of a mouse that had had a intracerebral tumor implant. A common underlying etiology could not be found. It is suggested, however, that this structure represents a specific axonal response to perhaps a variety of as yet unknown conditions.
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  • 26
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    Acta neuropathologica 10 (1968), S. 132-142 
    ISSN: 1432-0533
    Keywords: Myoclonus body disease ; Lafora bodies ; Electron microscopy ; Corpora amylacea ; Unverricht-Lundborg disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les auteurs analysent l'ultra-structure des corps de Lafora à propos d'une biopsie cérébrale pratiquée dans une maladie d'Unverricht-Lundborg caractéristique. La surcharge observée dans les périkaryons neuronaux et dans les prolongements dendroaxonaux, au niveau des synapses, comporte des structures filamenteuses hélicoïdales de 75 Å d'épaisseur, correspondant à des macro-molécules protéiques complexes, des corpuscules denses de 150 à 300 Å et une matrice finement granuleuse. Les corps de Lafora, dépourvus de membrane propre, correspondent à une sécrétion anormale ou à une transformation d'organites cellulaires. Des relations de continuité existent entre les filaments et les ribosomes ergastoplasmiques. Les auteurs soulignent les relations unissant corps de Lafora et corps amylacés. Ils discutent leur morphologie et la comparent à celle de plusieurs structures pathologiques connues d'aspect fibrillaire.
    Notes: Summary The authors analyse the Lafora bodies' ultra-structure about a cerebral biopsy in a typic case of Unverricht-Lundborg disease. This obvious storage is noticed in the nerve cells perikarya, dendro-axonal processes and synapses; it appears to be compound of helicoïdal, filamentous, 75 Å wide profiles corresponding to complex proteic macro-molecules, 150–300 Å wide densities and slightly granulous matrix. The Lafora bodies without any limiting membran correspond to a pathologic neuro-secretion or to changes of cytoplasmic organites. Some continuity is seen between filaments and ribosomes. The authors emphazise the relations connecting Lafora bodies and corpora amylacea. Their morphology is discussed and compared with that of several pathologic fibrillar structures.
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  • 27
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    Acta neuropathologica 10 (1968), S. 263-272 
    ISSN: 1432-0533
    Keywords: Hypertensive encephalopathy ; Ischemic-anoxic encephalopathy ; Edema anoxic ; Electron microscopy ; Astrocytic swelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurden elektronenmikroskopische Untersuchungen am Gehirn von Katzen bei akuter Hypertonie, die durch wechselnde Kompression der absteigenden Aorta erzeugt wurde, ausgeführt. Die ultrastrukturellen Veränderungen umfaßten Schwellung der Astrocytenausläufer, Erweiterung des endoplasmatischen Reticulums, und geringe Erweiterung des Extracellulärraumes des Gehirnmarks. Manchmal wurde auch Schwellung der Mitochondrien mit Zerstörung der Cristae beobachtet. Der Extracellulärraum der Gehirnrinde zeigte keine Erweiterung. Die Veränderungen in der Ultrastruktur des Zentralnervensystems werden im Hinblick auf die Pathogenese der hypertonischen Encephalopathie diskutiert.
    Notes: Summary Electron microscopic examinations were carried out in the brains of cats with acute arterial hypertension produced by intermittent compression of the descending aorta. The ultrastructural changes included swelling of the astrocytic processes, dilatation of the endoplasmic reticulum, and slight enlargement of the extracellular space of the white matter. Swelling of the mitochondria with disruption of the cristae was sometimes observed. The extracellular space of the gray matter showed no expansion. The changes in the ultrastructure of the central nervous system in hypertensive and ischemic encephalopathy were found to be very similar. This finding is discussed with special regard to the pathogenesis of acute hypertensive encephalopathy.
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  • 28
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    Acta neuropathologica 10 (1968), S. 308-323 
    ISSN: 1432-0533
    Keywords: Experimental brain tumors ; Virus with brain tumors ; Electron microscopy ; Histochemistry ; Hydrocarbon (crystalls), oncogenic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Krebserzeugende Kohlenwasserstoffe wurden in Gehirn und Muskel von C3H Mäusen implantiert. Dabei konnten virusähnliche, cylindrisch geformte Partikel in den präcarcinomatösen Läsionen nachgewiesen werden. Die filamentartigen Stäbchen wurden nur im Cytoplasma von solchen Zellen beobachtet, die phagocytiertes Carcinogen enthielten. Die meisten Zellen, in denen diese Viruspartikel nachzuweisen waren, wurden als Makrophagen angesehen und es wird angenommen, daß sie mesenchymaler Herkunft sind. Der genaue Mechanismus, durch den die krebserzeugende Wirkung der Kohlenwasserstoffe zur Bildung von Viruspartikel führt, ist nicht klar, aber offensichtlich ist das endoplasmatische Reticulum beteiligt. Viele Partikel konnten innerhalb der Cisternen beobachtet werden; dabei wurde ihre äußere Hülle von der Membran des endoplasmatischen Reticulums gebildet. Gelegentlich wurden die Viruspartikel auch zwischen den zwei Membranen der Kernhülle beobachtet. Die Bedeutung dieser Partikel in Beziehung zu den Tumoren ist unbestimmt. Die Möglichkeit besteht, daß sie eine unreife oder unvollendete Form darstellen und daß zusätzliche Faktoren erforderlich sind, um ihre krebserzeugende Wirkung hervorzubringen.
    Notes: Summary Carcinogenic hydrocarbons were implanted into brain and muscle of C3H mice. Virus-like particles of cylindrical form were demonstrated in the precancerous lesions. These filamentous rods were observed only within the cytoplasm of those cells which contained phagocytosed carcinogen. The majority of reactive cells containing the virus-like particles were identified as macrophages, and are thought to be mesenchymal in origin. The precise mechanism by which the carcinogenic effect results in the formation of virus-like particles is not clear, but evidently involves the endoplasmic reticulum. Many of the particles were found within the cisternae, and their outer shells were derived from the membranous component of the endoplasmic reticulum. Occasionally, they were seen between the two membranes of the nuclear envelope. The significance of these particles in relationship to tumors is not certain. The possibility exists that they represent immature or incomplete forms and that additional factors may be necessary to prove them oncogenic.
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  • 29
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    Acta neuropathologica 10 (1968), S. 324-335 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Rat brain, new born ; Brain injury ; Brain edema ; Extracellular space
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Reaktion des Gehirns neugeborener Ratten auf Stichverletzung wurde elektronenmikroskopisch untersucht. Die wenigen im Neugeborenenhirn vorhandenen protoplasmatischen Astrocyten erschienen an der Reaktion unbeteiligt. Hingegen erwies sich der Extracellularraum durch Anhäufung von Ödemflüssigkeit erweitert. Die Mikrogliazellen reagieren bemerkenswert schnell; viele, ganze Zellen sowie Myelinfiguren und Fetttröpfchen enthaltende Makrophagen werden schon 24 Stunden nach der Verletzung gefunden. Eine dichte Glia- oder Bindegewebsnarbe bildet sich nicht. Diese Reaktionen sind von denen für das reife Hirngwebe charakteristischen durchaus verschieden; mögliche Erklärungen für diese Unterschiede werden erörtert.
    Notes: Summary The reaction of the newborn rat brain following needle injury has been studied electron microscopically. Very few protoplasmic astrocytes are present in the newborn brain, and they do not appear to participate in the reaction. Instead, the extracellular space appears to be widened by an accumulation of oedema fluid. The microglial cells react remarkably rapidly; many macrophages containing whole cells as well as myelin figures and lipid droplets are found within 24 hours after the injury. At no time does a dense glial or connective tissue scar form. These reactions are quite different from those characteristic of mature brain tissue, and possible explanations for these differences are discussed.
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  • 30
    ISSN: 1432-0533
    Keywords: Hypocupremia, experimental ; Vascular pathology ; Basal brain arteries ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Kaninchen wurden in utero und post partum unter Entzug von Kupfer aus der Nahrung aufgezogen (die Nahrung enthielt nur 0,60 p.p.m. Kupfer). Eine Gruppe von Kontrolltieren wurde ebenfalls untersucht. Bei der post partum-Gruppe der Kaninchen dauerten die Versuche 2 Monate. Am Ende der 7. Woche wurden petechiale Blutungen in den Ohren beobachtet. Angiographisch wurden Gefäße des Kopfes und Nackens untersucht. Einige Dilatationen und Ungleichheiten wurden beobachtet. Bei zwei Tieren wurden Herzrisse festgestellt. Innerhalb von 2 Monaten wurden alle Tiere getötet und seziert. Es wurden Darmblutungen festgestellt. In der linken Niere einer der kupferarmen Kaninchen wurde eine cystenartige Bildung gefunden. Dieser Befund mag ein zufälliger gewesen sein. Das Herz, Cervicalgefäße und basale Hirngefäße wurden licht- und elektronenmikroskopisch untersucht. Anhäufungen von Fibroblasten, dissektive Blutungen und Defekte oder Brüche in Muskel- und elastischen Geweben wurden beobachtet. An den fibrösen Stellen wurde eine Anhäufung von neutral-rotem Material gefunden. Die Folgen des Entzugs von Kupfer aus der Nahrung waren somit Veränderungen des Herzens, muskulärer und elastischer Schichten der Cervicalgefäße und basalen Hirngefäße.
    Notes: Summary Rabbits were reared in utero and post partum under hypocupremic conditions (the diet containing only 0.60 p.p.m. copper). A control series was investigated as well. For the post partum series of rabbits the experiments lasted 2 months. At the end of the 7 th week petechial hemorrhages were observed in the ears. Angiography was carried out and cervical and head vessels were studied. Some vessel dilatations and unevennesses were observed. One animal died of heart rupture and another collapsed as a consequence of intramural bleeding in the ventricular wall. Within about two months all the animals were killed and autopsied. Intestinal bleedings were observed. A cystlike structure was found in a kidney of one hypocupremic rabbit. This finding may have been coincidental. The hearts and cervical and basal cerebral vessels were investigated by light and electron microscopy. Fibroblast accumulation, dissecting hemorrhages and defects or breaks in muscular and elastic tissue were observed. At the sites of fibrosis, accumulation of a neutral red-positive material was found. At the ultrastructural level lipids could be identified. Deprivation of dietary copper thus resulted in changes of the heart and muscularis and elastica layers of cervical and basal cerebral vessels of rabbits.
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  • 31
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    Acta neuropathologica 10 (1968), S. 218-241 
    ISSN: 1432-0533
    Keywords: Myotonic dystrophy ; Sarcoplasmic masses ; Striated annulets (Ringbinden) ; Muscle fiber ; Electron microscopy ; Phase microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Biopsiematerial von drei Patienten mit unterschiedlichen klinischen und pathologischen Stadien der myotonischen Dystrophie wurde phasenkontrast-und elektronenmikroskopisch untersucht. Beim 1. und 2. Fall waren “sarkoplasmatische Massen” und “Ringbinden” besonders zahlreich, während sie beim 3. Fall mit klinisch erheblich fortgeschrittener Muskelatrophie nur ausnahmsweise vorkamen. Elektronenmikroskopisch erschienen fast alle Elemente der Muskelfasern, zumindest an einigen Stellen, von dem atrophischen oder dystrophischen Prozeß betroffen: Myofilamente, Z-Streifen, Triaden, Kerne, Mitochondrien und Sarkolemm. Außerdem fanden sich cytoplasmatische Cysten, multilamellierte Körperchen, zahlreiche Lipofuscingranula und verschiedene andere abnorme Strukturen. Besonders kennzeichnend für die Erkrankung waren die “sarkoplasmatischen Massen”, die mit variablen Mengen von fehlorientierten Myofilamenten, aber auch von anderen Komponenten der Muskelzelle ausgefüllt waren. Die Ringbinden wurden von fehlorientierten Myofibrillen gebildet, indem sie meist kreisförmig die im Zentrum normal ausgerichteten Myofibrillen umschlossen. Einzelne Veränderungen, die bisher weder bei der myotonischen Dystrophie noch in irgendeiner anderen Muskelkrankheit nachgewiesen worden sind, konnten in leicht dystrophischen wie auch in hochgradig atrophischen Fasern nachgewiesen und identifiziert werden: Große homogene Lacunen, die sich vom sarkoplasmatischen Reticulum herleiten und eigenartige geometrische Anordnungen der terminalen Cisternen. Der Ursprung bestimmter anderer Strukturen blieb unklar. In unserem Material fanden sich keine segmentalen Nekrosen, so daß sich die Relation des dystrophischen Prozesses zur Zenkerschen Degeneration und zur Atrophie, den nach histologischen Untersuchungen wesentlichsten Befunden bei der Steinertschen Erkrankung, nicht eindeutig bestimmen ließ.
    Notes: Summary Biopsies from three patients with different clinical and pathological stages of myotonic dystrophy were studied by phase and electron microscopy. Large sarcoplasmic masses and spiral annulets were prominent in Cases 1 and 2 while in Case 3, featured clinically by atrophic weakness, they were infrequent. In the latter the residual fibers were either large and dystrophic or small and atrophic. Electron microscopically, nearly all components of the muscle cell, in places, were involved in the dystrophic or atrophic process, such as myofilaments, Z discs, triads, nucleic, mitochondria, and the sarcolemma. In addition, cytoplasmic cysts, multilammellated bodies, and lipofuscin granules were observed. The most characteristic feature of the disease were sarcoplasmic masses, filled with varying amounts of disoriented myofilaments and other sarcoplasmic components. Disoriented myofibrils often encircled the remaining core of normal myofibrils, thus forming the striated annulets (Ringbinden). Several other abnormalities, not previously reported in myotonic dystrophy or any other myopathy, were identified in slightly dystrophic as well as in severaly atrophic fibers. These were large, homogenous lacunes derived from the sarcoplasmic reticulum and peculiar geometric arrangements of terminal cisternae. The origin of some other structures remains obscure. The relation of the dystrophic process to segmental degeneration and atrophy, the principal histologic findings in Steinert's disease, is unsettled since segmental necrosis was not observed in our samples for phase and electron microscopy.
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  • 32
    ISSN: 1432-0533
    Keywords: Nuclear inclusion body ; Herpes-virus-infection ; Immunology ; Electron microscopy ; Nuclear metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die pathologischen Befunde bei einem 28 jährigen, schwachsinnigen Patienten beschrieben, der seit früher Kindheit progressive Spastizität und Ataxie zeigte. In Gehirn und allen anderen Organen wurden weitverbreitet eosinophile, intranucleäre Einschlußkörperchen, zugleich mit größeren, intensiver gefärbten, globulären Ablagerungen, gefunden. Corpus striatum, innere Kapsel, Pallidum und Thalamus waren besonders schwer betroffen. Die globulären Ablagerungen hatten sich wahrscheinlich aus vergrößerten, intranucleären Einschlußkörperchen entwickelt. Färberisch und histochemisch gaben beide Strukturen eine positive Reaktion für Protein. Entzündliche Reaktionen waren nicht vorhanden. Die Elektronmikroskopie zeigte, daß die intranucleären Einschlußkörperchen und die globulären Ablagerungen aus homogenem, feinkörnigem Material bestanden. Im Innern einer solchen Ablagerung in der inneren Kapsel wurden virusähnliche Partikel gesehen, die entweder unregelmäßig verteilt oder kristallartig angeordnet waren. Die Partikel sahen denen der Herpesvirusgruppe ähnlich. Es wird die Möglichkeit diskutiert, ob diese Veränderungen den Endzustand einer alten, generalisierten Herpesvirusinfektion darstellen, die entweder in früher Kindheit, zur Zeit der Geburt oder im Uterus stattgefunden hatte. Um den einzigartigen morphologischen Befund zu erklären, wird die Hypothese aufgestellt, daß entweder eine primäre immunologische Unzulänglichkeit vorlag oder daß eine Virusinfektion stattfand, bevor eine immunologische Kompetenz erworben war. Es wird kurz auf die zweite Möglichkeit hingewiesen, daß der Prozeß eine primäre, das Kernprotein beeinflussende Stoffwechselkrankheit darstellen könnte.
    Notes: Summary The pathologic findings are described in a mentally-retarded 28-year old man with progressive spasticity and ataxia since childhood. They consisted in the widespread presence, throughout the brain and visceral organs, of eosinophilic intranuclear inclusions, with the association of larger, more intensely staining globular bodies. The corpora striata, internal capsule, pallida and thalami were the most severely affected. The globular bodies seemed to be derived from the enlargement of the intranuclear inclusions: both gave the tinctorial and histochemical reactions for protein. There was no evidence of inflammation. Electron microscopy showed that the intranuclear inclusions and the globular bodies were composed of homogeneous finely granular material. In one such mass, in the internal capsule, virus-like particles, both randomly distributed and arranged in crystalline arrays, were seen. The particles resembled those of the herpesvirus group. The possibility is discussed that these alterations may present the residuum of an old generalized herpesvirus infection which could have been incurred in early life, at birth, or in utero. The hypothesis of a primary immunologic deficiency, or of a viral infection having occurred before the acquisition of immunologic competence, is advanced in order to account for the unique morphologic features. The alternative suggestion of a primary metabolic disorder affecting nuclear protein is briefly considered.
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  • 33
    ISSN: 1432-0533
    Keywords: Inclusion body, intranuclear ; Leucoencephalitis, subacute sclerotizing ; Electron microscopy ; Microtubuli (ultrastructural) ; Myxovirus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein klinisch-biologisch völlig typischer Fall von SSLE wurde enzymhistochemisch und elektronenoptisch untersucht. Enzymhistochemisch erwiesen sich die Läsionen als unspezifisch. Die nachgewiesenen Zunahme der oxydativen Enzyme ist identisch mit jener, die man bei allen reaktiven Makro- und Mikrogliosen beobachtet. Elektronenoptisch fanden sich keine intranucleären Einschlüsse aus Mikrotubuli von 170 bis 230 Å Durchmesser, deren Morphologie an gewisse Myxoviren erinnert. Andererseits bot dieser Fall auch lichtoptisch keine sicher nachweisbaren Kerneinschlüsse vom Typ Cowdry A, die bei SSLE nicht obligat sind. Die von einem Verfasser erstmals beobachteten mikrotubulären Einschlüsse erscheinen als das am meisten spezifische ultrastrukturelle Element der SSLE. Hingegen fanden sich bei der vorliegenden Beobachtung intracytoplasmatische Partikeln von virusähnlichem Aussehen, die vonGonatas bei SSLE und von den Verfassern bei entzündlicher diffuser Sklerose Typ Schilder beschrieben wurden. Gegenwärtig ergibt sich der Eindruck, daß diese Partikeln nicht spezifisch sind und ihre Deutung als virale Elemente größter Vorsicht bedarf. Es könnte sich um Sekretgranula in der Glia unter bestimmten pathologischen Bedingungen handeln, oder aber um phagocytierte Partikeln, die beispielsweise aus dem Myelin stammen.
    Notes: Summary Enzyme histochemical as well as electron microscopic studies were made in a typical case of SSLE. From the enzyme histochemical point of view the lesions were not specific, and the observed increase of oxydative enzymes is identical with that found in every reactive macro- and microgliosis. No intranuclear inclusions of microtubuli with a diameter of 170–230 Å resembling certain mixoviruses could be demonstrated by electron microscopy. By light microscopy, nuclear inclusions of the Cowdry type could not be demonstrated neither; however, they are not always found in SSLE. The microtubuli inclusions, observed for the first time by one of us, seem to be the most specific element in SSLE. On the other hand, the intracytoplasmatical particles with a virus-like aspect which have been described byGonatas in SSLE and by ourselves in periaxial diffuse encephalitis of the Schilder type were also found in the present case. Our impression is that these particles are nonspecific and great caution has to take place in classifying them as viral elements. They might be secretory granules arising in the glia in certain pathological conditions, or perhaps phagocyted particles, possibly stemming from myelin.
    Type of Medium: Electronic Resource
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  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 10 (1968), S. 279-294 
    ISSN: 1432-0533
    Keywords: Neurofibromas ; von Recklinghausen's disease ; Neurinomas (or schwannomas) ; Electron microscopy ; Peripheral nervous tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'examen en microscopie optique et électronique de 6 neurofibromes prélevés chirurgicalement chez des patients atteints de maladie de Recklinghausen autorise un certain nombre de conclusions: l'ultrastructure des neurofibromes est faite de 2 types de cellules (cellules de Schwann et fibroblastes) dispersées au sein d'un espace extra-cellulaire contenant de nombreuses fibres de collagène. Des axones myélinisés et amyéliniques sont présents; l'aspect ultrastructural de 3 neurinomes de l'acoustique a été comparé à celui des neurofibromes et apparaît comme différent. Les neurinomes sont faits d'un seul type cellulaire (très probablement cellule de Schwann), le collagène y est beaucoup moins abondant, les axones absents. Quelques déductions pathogéniques et nosologiques sont proposées.
    Notes: Summary Six neurofibromas from patients with von Recklinghausen's disease have been examined by light and electron microscopy: 2 types of cells have been found (Schwann cells and fibroblasts) scattered in extracellular spaces rich in collagen fibers. Myelinated and nonmyelinated axons were observed. These data have been compared with other ones collected from 3 acoustic neurinomas. These latter contained only one cellular type (very likely to be Schwann cell), much less collagen and no axon at all. A pathogenic and nosologic discussion is given.
    Type of Medium: Electronic Resource
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  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 6 (1968), S. 89-99 
    ISSN: 1432-1106
    Keywords: Substantia gelatinosa ; Dorsal root fibers ; Light microscopy ; Electron microscopy ; Operated rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The terminal degeneration in the substantia gelatinosa of the rat was studied with the Fink-Heimer silver technique following dorsal root section. Providing the survival time of the animal was in the range of 1–4 days, a massive degeneration was seen in lamina I, II and III of Rexed. The light microscope findings were corroborated by electronmicroscopic observations of degenerating boutons. Spinal cord material examined with silver methods one week after dorsal root section showed few signs of degeneration in the substantia gelatinosa. Although a significant dorsal root distribution to the substantia gelatinosa was found also in the cat, the terminal degeneration in lamina II showed considerable regional variations in this species.
    Type of Medium: Electronic Resource
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  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 148 (1968), S. 255-274 
    ISSN: 1591-9528
    Keywords: Adipose tissue ; Fat cells ; Isolated fat cells ; Electron microscopy ; Ultrastructure ; Tissu adipeux ; Cellules adipeuses isolées ; Microscopie électronique ; Ultrastructure ; Fixation de tissus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Au cours de ces dernières années, la recherche biochimique au niveau du tissu adipeux a pris un très grand développement. La technique d'isolement des cellules adipeuses a beaucoup contribué à accroître la connaissance de leur métabolisme, rendant plus nécessaire encore l'étude des corrélations existant entre les données biochimiques et l'aspect ultrastructural. Ce travail porte sur la préparation de ce matériel pour l'observation au microscope électronique. Les cellules adipeuses sont des «gouttes» lipidiques recouvertes d'une fine couche de cytoplasme. La fragilité qui en résulte nécessite une préparation particulière: 1. les cellules doivent être maniées avec précaution tout au long de la préparation; 2. il faut fixer très peu de cellules à la fois; 3. cette fixation requiert une concentration élevée d'osmium, sans quoi les lipides de la cellule restent partiellement solubles dans les solvants employés pour la déshydratation. Il faut admettre que l'osmium modifie les propriétés de solubilité des triglycérides, probablement de par sa fixation au niveau des doubles liaisons, ou en facilitant une liaison en chaîne unissant les triglycérides entre eux par l'intermédiaire des doubles liaisons de leurs acides gras; 4. l'enrobage peut être fait au Vestopal ou à l'Epon, ce dernier étant techniquement plus maniable. Isolées, les cellules adipeuses sont semblables aux cellules fixéesin situ. Les cellules adipeuses présentent une particularité: la gouttelette lipidique est isolée du cytoplasme par une membrane elle-même doublée du côté cytoplasmique par des saccules du reticulum endoplasmique lisse disposés parallèlement à elle.
    Notes: Summary During these past years, an increasing attention has been paid to the biochemical aspects of metabolic regulation in adipose tissue. An important advance has been that of the availability of a technique for the isolation of adipose cells without contamination by any other cellular component. As yet, morphological investigations have not kept up with biochemical ones, and little is known about the ultrastructural aspects of isolated adipose cells. The present study describes the precautions required during the preparation of isolated adipose cells for study with the electron microscope. These cells are lipid “droplets” surrounded by an extremely thin cytoplasmatic layer and their fragility requires special precautions: 1. the cells must be carefully handled at all stages of preparation, avoiding mechanic or chemical trauma; 2. only small numbers of cells should be processed at any one time; 3. fixation requires a relatively high concentration of osmium to prevent continued partial solubility of the triglycerides in the solvents used for dehydration. It would seem that osmium modifies the solubility of triglycerides, probably through reaction at the level of the double bonds, perhaps facilitating cross-linkage between triglycerides at the level of the double bonds of the fatty acids involved; 4. either Vestopal or Epon can be used for embedding, Epon being somewhat easier to handle technically. Isolated adipose cells resemble in most aspects cells fixedin situ, while presenting one added particularity. In the isolated, spherical fat cell, the fat droplet is isolated from the cytoplasm by a membrane, which is itself associated with numerous saccules of smooth endoplasmic reticulum along the cytoplasmic surface of the membrane.
    Type of Medium: Electronic Resource
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