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  • 1995-1999  (85)
  • 1975-1979  (111)
  • 1890-1899
  • 1995  (85)
  • 1975  (111)
  • Electron microscopy  (196)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Lasers in medical science 10 (1995), S. 93-104 
    ISSN: 1435-604X
    Keywords: Copper vapour laser ; Electron microscopy ; Illumination time ; Numerical modelling ; Optimal treatment ; Port-wine stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract This paper reports the electron microscopy results obtained from two patients who were treated with 5 W of yellow (578 nm) light from a copper vapour laser with an illumination time of 3.6 ms and a 0.3 mm spot diameter. The endpoint of treatment was transient blanching. Following treatment, erythema was observed. There was minimal damage to the epidermis and non-vascular tissue such as the nerve fibres. There was severe damage to the endothelial cells of the ectatic vessels. Twenty-four hours after treatment, platelet activation and collagen were present, indicating that these vessels were no longer viable. Theoretical calculations are used to determine the flow of heat within and away from a 50μm diameter vessel. From this, heating of the entire vessel is shown to occur with illumination times of 4 ms, with minimal heating of the non-vascular tissue. Shorter illuminations do not heat the entire vessel, while the use of longer illumination times will cause excessive damage to the surrounding non-vascular tissue. Illumination times close to 4 ms must be regarded as optimal.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 73 (1995), S. 73-77 
    ISSN: 1432-1440
    Keywords: Chloroquine ; Cardiomyopathy ; Heart ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Light microscopic and ultrastructural findings in patients suffering from chloroquine-induced cardiomyopathy are reviewed. Based on our own observations in an autopsy case, functional and morphological similarities between chloroquine effects and hereditary lysosomal storage diseases are discussed.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2307
    Keywords: Graft-versus-host disease ; Cell blebs ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Subnuclear blebbing of the superficial colonic epithelium, a rarely described light and electron microscopic change in graft-versus-host disease (GVHD), was studied in a murine model of GVHD. Severity of changes induced by transfer of various donor T cell subsets to irradiated, allogeneic recipients, and association with more severe alterations such as erosions and ulceration were evaluated. By light microscopy the basal region of the superficial enterocytes was greatly expanded by eosinophilic to amphophilic, flocculent, sometimes vacuolated material. By electron microscopy these changes were found to be organelle-poor, cytoplasm-filled protrusions from the basal surface of the epithelium. In this model, helper T cells (CD4+-enriched, CD8+-depleted T cells) transplanted after high dose irradiation were capable of causing the change suggesting cytokine responses may be involved in mediating the cellular injury seen histologically. Close association of blebbing and erosions suggest the blebbing may be the precursor to epithelial erosion or denudation seen in severe intestinal GVHD.
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  • 4
    ISSN: 1432-2307
    Keywords: Giant cell tumour of bone ; In vitro resorption ; Leukaemia inhibitory factor ; Synthetic calcium phosphate ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Osteoclastic cells from giant cell tumour of bone (GCT) of bone provide a rich source for investigation of cellular mechanisms leading to formation of multinucleated cells, the resorption process and involvement of hormones and cytokines in these events. In the present study we investigated the effect of 1,25-dihydroxyvitamin D3 (VD3) and leukaemia inhibitory factor (LIF) on the resorbing potential of osteoclast of GCT origin using quantitative image-analysis of resorption lacunae in an in vitro dentine model. While VD3 unsignificantly increased the number of resorption pits and implicated surface after 7 days of GCT cell culturing, the stimulative effect of LIF was statistically significant. In cultures supplemented with LIF (5000 U/ml) the number of lacunae and resorption surface increased by 38% and 55%, respectively, when compared with control cultures. We suggest that both osteotropic agents increased osteoclastic activity, as the number of multinucleated cells was similar in control and experimental cultures. Seeding of GCT cells on biphasic calcium phosphate substratum revealed the relative inability of osteoclastic cells to resorb this synthetic material.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 426 (1995), S. 523-528 
    ISSN: 1432-2307
    Keywords: Von Hippel-Lindau disease ; Neuroendocrine tumour ; Electron microscopy ; Flow cytometry ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 21-year-old woman with a family history of von Hippel-Lindau disease presented with a mass in the head of the pancreas. Light microscopic features of the tumour suggested neuroendocrine differentiation and although it displayed positive immunostaining for the antigens expected in a neuroendocrine neoplasm, S-100 staining was also present. This unusual feature prompted further evaluation by routine and post-embedding protein-A gold immunoelectron microscopy, which demonstrated the presence of neuroendocrine granules. Tumour cell DNA content was normal by flow cytometry. Although this patient exhibited no other signs of von Hippel-Lindau disease, the presence of a pancreatic tumour with neuroendocrine differentiation demonstrated that she was affected. Future surveillance and genetic counselling will be influenced by this diagnosis.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1572-9648
    Keywords: Electron microscopy ; Microstructures ; Phase transitions ; Solid mechanics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Description / Table of Contents: Sommario Si presentano i risultati di alcuni studi fatti attraverso la microscopia elettronica sulle microstrutture relative a transizioni di fase in una varietà di materiali. I casi comprendono leghe binarie e ternarie, superconduttori TC e materiali C60 e C70; le transizioni esaminate sono diffusionali, displacive o di entrambi i tipi.
    Notes: Abstract In this contribution the results of some electron microscopy studies on microstructures related with phase transitions in a variety of materials will be presented. The materials include binary and ternary alloys, high TC superconductors as well as C60 and C70 fullerenes, while the transitions can be diffusional, displacive or both.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0533
    Keywords: Key words Tonsillar herniation ; Syringomyelia ; Chiari malformations ; Histology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8–14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n = 6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extracellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n = 4) and those rats without tonsillar herniation (n = 4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 192 (1995), S. 265-274 
    ISSN: 1432-0568
    Keywords: Lymphatics ; Valves ; Microanatomy ; Vimentin filaments ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The microanatomy and ultrastructure of the feline and canine thoracic duct and afferent lymphatics were studied by scanning and transmission electron microscopy. We found that the lymphatic vessels were always terminated by ostial valves of two shapes, crescent- and navicular-like, in a ratio of 4∶1. Specific regulatory structures along the free edges of the valves, including marginal thickenings and buttresses, are described. The tissue and cellular organization of the valve endothelium showed distinct peculiarities, particularly in the orientation and shape of the cells and their microrelief. We found that valvular endothelial cells, especially „tip cells”, which are situated in unfavourable lymphodynamic conditions, were characterized by an increased volume density of intermediate (probably vimentin-based) filaments, suggesting an accommodative mechanism involving such filaments.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0533
    Keywords: Tonsillar herniation ; Syringomyelia ; Chiari malformations ; Histology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8–14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n=6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extracellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n=4) and those rats without tonsillar herniation (n=4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 90 (1995), S. 194-197 
    ISSN: 1432-0533
    Keywords: Key words Alzheimer's disease ; Paired helical ; filaments ; Electron microscopy ; Tau
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate if Alzheimer paired helical filaments (PHF) closely resemble twisted ribbons, as indicated by recent high-resolution ultrastructural studies, we compared physical models of twisted ribbons with electron microscopic images of PHF. Uranyl-acetate-stained, isolated PHF with one or two helical turns were compared with scale models of twisted ribbons with one and two helical turns rotated at different angles. The various rotations of the twisted ribbon model corresponded well with the different orientations of randomly dispersed PHF. The electron-dense regions of individual PHF turns previously thought to represent a cross-over site of paired filaments corresponded to the edge of the twisted ribbon when the ribbon was oriented perpendicular to the filament axis. These data indicate that the overall configuration of PHF is a twisted ribbon but does not exclude possible configuration restrictions due to an ordered arrangement of subunits.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 90 (1995), S. 194-197 
    ISSN: 1432-0533
    Keywords: Alzheimer's disease ; Paired helical filaments ; Electron microscopy ; Tau
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate if Alzheimer paired helical filaments (PHF) closely resemble twisted ribbons, as indicated by recent high-resolution ultrastructural studies, we compared physical models of twisted ribbons with electron microscopic images of PHF. Uranyl-acetate-stained, isolated PHF with one or two helical turns were compared with scale models of twisted ribbons with one and two helical turns rotated at different angles. The various rotations of the twisted ribbon model corresponded well with the different orientations of randomly dispersed PHF. The electron-dense regions of individual PHF turns previously thought to represent a cross-over site of paired filaments corresponded to the edge of the twisted ribbon when the ribbon was oriented perpendicular to the filament axis. These data indicate that the overall configuration of PHF is a twisted ribbon but does not exclude possible configuration restrictions due to an ordered arrangement of subunits.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 89 (1995), S. 85-95 
    ISSN: 1432-0533
    Keywords: Neonatal de-efferentation ; Sensory denervation ; Electron microscopy ; Intrafusal muscle fibre types ; Postnatal myogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructure of muscle spindles de-efferented by the extirpation of the lumbosacral spinal cord at the age of 2 days and subsequently deprived of their sensory innervation by the section of the sciatic nerve at 3–4 weeks of age was studied in serial sections of 2-month-old rat hindlimb muscles. De-efferentation leaves the primary sensory neurons and their peripheral axons intact and capable of inducing the muscle spindle morphogenesis during the critical period of their development. In de-efferented and subsequently denervated muscle spindles, new supernumerary intrafusal muscle profiles (SIPs) appeared in the muscle spindle A region. They were formed in intimate spatial relation with the original intrafusal muscle fibres (IMFs) predominantly from activated satellite cells derived from both nuclear bag (larger diameter) and nuclear chain fibres. SIPs, however, lacked the typical nuclear accumulations, as well as other ultrastructural distinctions present in control IMFs. The majority of differentiated SIPs separated from original IMFs, whereas the less differentiated SIPs were usually closely apposed to the surface of the parent IMFs and both were covered by the common basal lamina. In some spindles, the original IMFs and/or new SIPs at different stages of their differentiation were found together and they formed clusters of variable shape and composition. In the majority of clusters, all profiles seemed to be isolated along their entire length, although in few clusters, occasional cytoplasmic connections of variable length between intrafusal profiles were found. This result is important for the interpretation of the forthcoming study of expression of muscle spindle-specific myosin heavy chain isoforms in denervated SIPs in rat muscle spindles gradually deprived of their motor and sensory innervation.
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  • 13
    ISSN: 1432-0533
    Keywords: Astrocytes ; Alzheimer's disease ; Electron microscopy ; Paired helical filaments ; Straight tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ultrastructural investigation of the hippocampal CA1 and CA4 of nine sutopsy-proven cases of dementia of the Alzheimer type (duration of disease: 3–16 years; age: 76–92 years) revealed paired helical filaments (PHFs) and straight tubules (STs) in astrocytes of three advanced cases of long duration (〉13years). The PHFs and STs were indistinguishable from those seen in neurons. The abnormal glial fibrils were confined to the astrocytic processes that were associated with small vessels or, more frequently, with ghost tangles. In both locations the astrocytic PHFs and STs were located in the cytoplasm without limiting membranes, and were thicker than the straight filaments that composed ghost tangles. These findings, combined with the presence of regular constrictions of astrocytic PHFs, suggest that abnormal astrocytic fibers are produced by the glial cells, not engulfed by them. In addition, the presence of these abnormal glial filaments in only advanced, long-duration cases of dementia of the Alzheimer type suggests that disease duration has a significant effect upon the formation of these astrocytic profiles.
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  • 14
    ISSN: 1432-0533
    Keywords: Key words Astrocytes ; Alzheimer's disease ; Electron microscopy ; Paired helical filaments ; Straight tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ultrastructural investigation of the hippocampal CA1 and CA4 of nine autopsy-proven cases of dementia of the Alzheimer type (duration of disease: 3–16 years; age: 76–92 years) revealed paired helical filaments (PHFs) and straight tubules (STs) in astrocytes of three advanced cases of long duration (〉13 years). The PHFs and STs were indistinguishable from those seen in neurons. The abnormal glial fibrils were confined to the astrocytic processes that were associated with small vessels or, more frequently, with ghost tangles. In both locations the astrocytic PHFs and STs were located in the cytoplasm without limiting membranes, and were thicker than the straight filaments that composed ghost tangles. These findings, combined with the presence of regular constrictions of astrocytic PHFs, suggest that abnormal astrocytic fibers are produced by the glial cells, not engulfed by them. In addition, the presence of these abnormal glial filaments in only advanced, long-duration cases of dementia of the Alzheimer type suggests that disease duration has a significant effect upon the formation of these astrocytic profiles.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 192 (1995), S. 257-264 
    ISSN: 1432-0568
    Keywords: Cholinesterases ; Electron microscopy ; Development ; Mouse embryo ; Somites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract During the development of somites in mouse embryos, widespread activity of unspecific cholinesterase (BuChE) was demonstrated after prolonged incubation. Independent of their position, all somite cells and their derivatives (dermatome, myotome and sclerotome) exhibited enzyme activity in the perinuclear space and in the endoplasmic reticulum. The plasmalemma did not show any enzyme activity. Differentiation of the sclerotome into vertebrae was accompanied by a reduction of BuChE. However, a low enzyme reaction was still present in the first typical differentiated chondroblasts. Notochordal cells were detectable by their high BuChE content. This was also found in cells already showed severe degeneration. In addition to BuChE, acetylcholinesterase (AChE) was first visible on day 9 of embryonic development in newly formed myotubes of the myotomes. Some hypotheses on the functional significance of embryonic BuChE are discussed in the light of these results.
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  • 16
    ISSN: 1432-0827
    Keywords: Bone sialoprotein ; osteoblast ; Bone matrix ; Electron microscopy ; Immunolocalization ; noncollagenous protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Bone sialoprotein was immunolocalized at the EM level in thin Lowicryl K4M sections of rat bone. Because of the unconventional EM morphology of the bone matrix seen in thin demineralized acrylate sections, the pattern of immunolabeling was compared with detailed structural images of demineralized bone obtained using an en bloc treatment of tissue samples with the cationic electron ‘dye’, Malachite Green (MG), which provides stabilization and retention of anionic material throughout specimen processing. A system of structures corresponding to the sites of bone sialoprotein (BSP) immunoreactivity, as seen in Lowicryl K4M thin sections, could be readily identified in the MG-treated, expoxy thin sections. This system includes the cement lines, and aggregates of similar material within mineralized bone and mineralizing osteoid. The virtual identity of BSP distribution with the arrangement of the MG-visualized material indicates that a BSP-enriched, noncollagenous phase can be demonstrated using different, unrelated tissue preparation and imaging protocols for EM. Besides improving our understanding of the distribution of bone sialoprotein in bone, these data assign a previously unrecognized structural dimension to noncollagenous material in the bone matrix.
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  • 17
    ISSN: 1432-0827
    Keywords: Cathepsin inhibitors ; Osteoclasts ; Resorption ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract This study was designed to evaluate the effects of specific and potent cathepsin inhibitors on osteoclastic resorptive functions in vitro by means of a novel ultrastructural assay system. Mouse bone marrow cell-derived osteoclasts were suspended on dentine slices and cultured for 48 hours in the presence of either E-64 (a generalized cysteine proteinase inhibitor) or Z-Phe-Phe-CHN2 (a selective cathepsin L inhibitor). After the removal of cultured osteoclasts, co-cultured dentine slices were examined using electron microscopy: backscattered (BSEM), scanning (SEM), and atomic force (AFM). In morphometric analyses of BSEM images, there were no significant differences in the areas of demineralized dentine surfaces between control and inhibitor-treated groups, suggesting that cathepsin inhibitors had no effect on dentine demineralization by cultured osteoclasts. However, in SEM and AFM observations, both inhibitors remarkably reduced to the same extent, the formation of deep resorption lacunae on dentine slices that had resulted from degradation of matrix collagen. In addition, Z-Phe-Phe-CHN2 treatment produced deeper, ring-like grooves with little collagen exposure in shallow resorption lacunae. These results strongly suggest that (1) cathepsins released by osteoclasts are involved in the formation of deep resorption lacunae, and (2) cathepsin L plays a key role in bone resorption.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 21 (1995), S. 482-489 
    ISSN: 1432-1238
    Keywords: Mucociliary clearance ; Ultrastructural ciliary alterations ; Cilia ; Electron microscopy ; Intubation ; Mechanical ventilation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective The objective of this study was to investigate whether reduced bronchial mucus transport velocity (BTV) is associated with a loss of cilia or ultrastructural abnormalities of cilia in intubated patients. Design The patients were studied prospectively in a convenience sample trial. Setting The study took place in a university hospital. Patients and participants 29 orally intubated patients in a surgical ICU. Interventions BTV was measured with radiolabeled microspheres in the right and left primary bronchus. Following these measurements, biopsy samples were taken from the bronchi for scanning (SEM) and transmission (TEM) electron-microscopic investigations. Measurements and results SEM: Patients with normal or slight impaired BTV (group 1,n=14: BTV: 8.5 mm/min (3.8–11.5); median with range) showed more cilia on the luminal surface than patients with markedly depressed BTV (p〈0.05) (group 2,n=15: BTV: 0(0–2.1)). The difference was statistically significant. The BTV values correlated moderately with the number of cilia on the luminal surface (r=0.46;p=0.02). TEM: In group 1, 6.5% (3.9–14.9) of cilia were abnormal (median with range) vs 9.3% (4.9–13.7) in group 2; these differences were not statistically significant. Neither was there any significant correlation between BTV and the frequency of abnormal cilia. Conclusions Impaired mucociliary transport in intubated patients is associated with a loss of cilia rather than ultrastructural abnormalities of cilia, which are less relevant.
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  • 19
    ISSN: 1432-1173
    Keywords: Schlüsselwörter Angiokeratoma corporis diffusum ; Lysosomale Stoffwechselstörung ; Elektronenmikroskopie ; Kapillarmikroskopie ; Key words Angiokeratoma corporis diffusum ; Lysosomal disorder ; Electron microscopy ; Capillary microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In a 22-year-old woman with mental impairment and some signs of dysmorphism, numerous angiokeratomas developed, starting when she was 3 years old and resulting in the clinical picture of angiokeratoma corporis diffusum. Extensive laboratory analyses did not disclose any associated metabolic disorder, and electron microscopy failed to demonstrate lysosomal inclusions. Therefore, this patient can be classified as one of the rare cases of angiokeratoma corporis diffusum without associated metabolic disease (idiopathic angiokeratoma corporis diffusum).
    Notes: Zusammenfassung Bei einer 22jährigen Patientin mit ausgedehnten, ab dem 3. Lebensjahr auftretenden Angiokeratomen im Sinne eines Angiokeratoma corporis diffusum, welche zusätzlich eine Intelligenzminderung und Dysmorphiezeichen aufwies, konnte trotz intensiver Suche laborchemisch keine assoziierte Stoffwechselstörung gefunden werden. Der fehlende Nachweis einer lysosomalen Speicherung in der Elektronenmikroskopie stützte diesen Befund. Somit liegt bei dieser Patientin die seltene Situation eines Angiokeratoma corporis diffusum ohne assoziierte Stoffwechselkrankheit (idiopathisches Angiokeratoma corporis diffusum) vor.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Der Pathologe 16 (1995), S. 404-407 
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Nerval-neuroendokriner Komplex ; Zollinger-Ellison-Syndrom ; Magenschleimhaut ; Elektronenmikroskopie ; Key words Nerve fibre-neuroendocrine cell complex ; Stomach ; Zollinger-Ellison-Syndrom ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Nerve fibre-neuroendocrine cell complexes (NF-NEC-C's) are neuroendocrine cells located in the lamina propria of the gastrointestinal tract directly connected with nerve fibres of Meissner's plexus. We report on a patient with sporadic Zollinger-Ellison syndrome (ZES) with electron microscopically demonstrated multiple NF-NEC-C's in non-antral gastric mucosa. It is suspected that in ZES the hypergastrinaemia may represent a trophic stimulus for the proliferation of NF-NEC-C's in the gastric mucosa.
    Notes: Zusammenfassung Unter nerval-neuroendokrinen Komplexen (N-NE-K) versteht man in der Lamina propria mucosae des Magen-Darm-Traktes gelegene Nester neuroendokriner Zellen, die in direktem Kontakt zu Nervenfasern des Meissner-Plexus stehen. Es wird über einen Patienten mit sporadischem Zollinger-Ellison-Syndrom (ZES) berichtet, bei dem sich elektronenmikroskopisch in nonantraler Magenschleimhaut multiple N-NE-K fanden. Möglicherweise stellt die Hypergastrinämie bei ZES einen trophischen Stimulus für die Proliferation von N-NE-K in der Magenschleimhaut dar.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 163 (1995), S. 300-306 
    ISSN: 1432-072X
    Keywords: Nitrosomonas europea ; Hydroxylamine oxidoreductase (HAO) ; Electron microscopy ; Electron spectroscopic imaging ; Quaternary structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The hydroxylamine oxidoreductase from Nitrosomonas europaea was prepared to apparent electrophoretic homogeneity. Electron microscopy of negatively stained preparations of the sample revealed an overall diameter of about 8.8 nm of the enzyme particle. The native structure was determined as a tetrahedron-like assembly of identical subunits exhibiting four protein masses.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 163 (1995), S. 300-306 
    ISSN: 1432-072X
    Keywords: Key wordsNitrosomonas europea ; Hydroxylamine ; oxidoreductase (HAO) ; Electron microscopy ; Electron ; spectroscopic imaging ; Quaternary structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The hydroxylamine oxidoreductase from Nitrosomonas europaea was prepared to apparent electrophoretic homogeneity. Electron microscopy of negatively stained preparations of the sample revealed an overall diameter of about 8.8 nm of the enzyme particle. The native structure was determined as a tetrahedron-like assembly of identical subunits exhibiting four protein masses.
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  • 23
    ISSN: 1432-1173
    Keywords: Schlüsselwörter Morbus Hailey-Hailey ; Pemphigus chronicus benignus familiaris ; Polymerasekettenreaktion ; Herpes-simplex-Virus ; Elektronenmikroskopie ; Histologie ; Key words Hailey-Hailey disease ; Benign familial pemphigus ; Polymerase chain reaction ; Herpes simplex virus ; Electron microscopy ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A 49-year-old man suffered from Hailey-Hailey disease for several years. The patient presented with an acute exacerbation of the disease, which did not respond to oral treatment with high doses of glucocorticosteroids. A skin biopsy was taken and the histological examination indicated a viral infection. Herpes simplex virus was confirmed by electron microscopy (negative staining) and polymerase chain reaction (PCR). The PCR presents a sensitive and effective molecular-biological method for the diagnosis of viral infections.
    Notes: Zusammenfassung Es wird über einen 49jährigen Patienten berichtet, bei dem seit Jahren ein Morbus Hailey-Hailey bekannt ist. Bei einem Rezidiv der Erkrankung kam es trotz hoher Glukokortikosteroidgaben zu keiner Remission. Erst die erneute diagnostische Abklärung des Rezidivs durch eine Hautprobe ergab den Verdacht auf eine Herpessimplex-Virus-Infektion, die über elektronenmikroskopische Negativkontrastierung und über Polymerasekettenreaktion (PCR) bestätigt werden konnte. Anhand dieser Kasuistik wird auf ein neueres molekularbiologisches Verfahren hingewiesen, das eine sensitive und schnelle Methode zum Virusnachweis darstellt.
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  • 24
    ISSN: 1432-2307
    Keywords: Adult Niemann-Pick disease ; Generalized AL-amyloidosis ; Progressive liver failure ; Fibroblast culture ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a case in which an adult form of Niemann-Pick disease (type B of NPD) was associated with a rapidly progressive generalized AL amyloidosis of kappa type. Both diagnosis were made by biopsy, the NPD by bone marrow biopsy and fibroblast culture, the amyloidosis by liver biopsy. Malignant non-Hodgkin lymphoma was not found. The patient, a 67-year-old woman, died from hepatic coma subsequent to a progressive liver failure. We discuss possible relations between the lysosomal storage disease and the development and rapid progression of amyloidosis.
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  • 25
    ISSN: 1432-0878
    Keywords: Key words: Node of Ranvier ; Axon ; Horseradish peroxidase (HRP) ; Retrograde axonal transport ; Electron microscopy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Horseradish peroxidase (HRP) was injected into the left dorsal column nuclei of adult cats. Large dorsal funiculi axons of the C3, C5, C8 and L7 segments were searched for HRP-activity after 12, 24, 36 and 48 h using light and electron microscopy. Accumulations of intra-axonal HRP-positive bodies occurred at nodes of Ranvier in the C3–C8 segments at 12, 24 and 36 h and in the L7 segments at 24, 36, and 48 h. The accumulations of HRP in three spatio-temporally different consecutive patterns, noted earlier at nodes of Ranvier in the peripheral nervous system (PNS) portion of feline alpha motor axons for more than 70 h after an intramuscular injection of the enzyme, were not observed in the present material. We suggest that the differences in the modes in which large PNS and CNS axons interact with retrogradely transported HRP are due to differences in the organization of the respective nodal regions. We also emphasize that endocytosis via axon terminals in the CNS normally represents uptake of material from an extracellular space which is controlled and protected by the blood-brain barrier. This is in contrast to endocytosis via axon terminals in a muscle, which represents uptake of material from an extracellular space openly exposed to influx of different substances from the blood stream.
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  • 26
    ISSN: 1432-0878
    Keywords: Key words: Lateral heart nerve ; FMRFamide ; Allatostatin ; Coexistence ; Mirror-section ; Axosomatic synapses ; Electron microscopy ; Periplaneta americana (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Both allatostatin immunoreactivity (AS-IR) and FMRFamide immunoreactivity (FMRFa-IR) have been demonstrated light-microscopically in the lateral heart nerve of Periplaneta americana. The identical labeling of some fibers suggests the coexistence of the two antigens. Electron-microscopically, six granule types in the peripheral part of the lateral heart nerve can be distinguished according to their size and density (types 1–6). These granule types can be subdivided immunocytochemically by means of a new mirror-section technique. Granules of types 4 and 5 always exclusively show FMRFa-IR. In the populations of fibers containing granules of types 1 and 6, axon profiles can be found that contain granules colocalizing FMRFa-IR and AS-IR. Other axon profiles of these populations only contain immunonegative granules of the same ultrastructure. Granules of type 2 can be differentiated immunocytochemically in three forms in the same section: In some fibers, they are nonreactive; in other fibers of the same section, they show FMRFa – IR, whereas in a third fiber type, granules show AS – IR. Finally, granules of type 3 can be observed with FMRFa-IR. In other fibers, they occur with the same ultrastructure but exhibit no immunoreactivity. Two soma types occur in the lateral heart nerve. Soma type I is characterized by the production of electron-dense granules that show FMRFa-IR. Type II is in close contact with various fibers, forming different types of axosomatic synapses, hitherto unknown in Insecta.
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  • 27
    ISSN: 1432-0878
    Keywords: Key words: Spermatozoa ; Acrosome ; Thiols ; Disulphides ; Electron microscopy ; Monomaleimido nanogold ; Macropus eugenii (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. This study utilised a commercially available monomaleimido-nanogold reagent to directly label cellular thiol groups (SH) of marsupial (tammar wallaby) spermatozoa before and after reduction of disulphides (S-S) with mercaptoethylamine hydrochloride (MEA). The sperm surface, mitochondrial membranes, axoneme and tail fibres were all labelled with gold particles before MEA treatment and the label intensity was increased after S-S reduction. The acrosomal membranes and matrix of spermatozoa contained no detectable SH prior to MEA treatment. However, after moderate MEA treatment (1 mg/ml) gold label was associated with the acrosomal membrane and invaginated acrosomal membrane within the acrosomal matrix. After exposure to 5 and 10 mg/ml MEA, gold particles heavily labelled the acrosomal matrix. Thus, the acrosomal membranes and matrix of tammar wallaby spermatozoa both contain S-S cross-linked structures, and this may contribute to the unusual stability of the marsupial acrosome. Under all treatment conditions the nucleus remained unlabelled. This is consistent with early studies which indicated that cysteine was absent from the nuclear protamines. The study also demonstrated that monomaleimido-nanogold can be used to resolve SH- and S-S-rich cellular structures directly, in addition to its use to label antibodies and Fab fragments for immunochemical localisation.
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  • 28
    ISSN: 1432-0878
    Keywords: Somatotrophs ; Growth hormone ; Growth hormone-releasing factor ; Secretory granule ; Electron microscopy ; Morphometry ; Rat (Fischer 344)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The anterior pituitary tissue of male rats injected with growth hormone-releasing factor (GRF) was either processed for stereology at the light-and electron-microscopic levels, or homogenized for growth hormone (GH) assay 2–60 min after GRF injection. Secretory granules of somatotrophs became smaller but increased in numerical density 2 min after GRF injection. Their volume density began to increase at 5 min. The frequency of exocytosis of the granules was most prominent as early as 2 min after GRF injection and reduced thereafter. GH levels in the tissue were lowest at 2–5 min, and returned to the control value by 60 min. Serum GH levels were highest at 15 min; even at 60 min, this value was higher than in the controls. These findings suggest that secretory granules in somatotrophs are stimulated to divide by GRF, resulting in a decrease in size and an increase in number. The discrepancy between the earlier formation of new secretory granules and the later restoration of intracellular GH levels implies that GRF first stimulates the synthesis of constituents of granules other than GH, and only later the synthesis of GH, and that newly formed small secretory granules contain less GH. From the clearance rate of serum GH and the frequency of granule exocytosis, it can be estimated that about a half million granules are released to maintain 1 ng/ml of serum GH in rats.
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  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 280 (1995), S. 183-188 
    ISSN: 1432-0878
    Keywords: Blood platelets ; Oxidized LDL ; Cytochalasin D ; Reflection contrast microscopy ; Image analysis ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The adhesion of human blood platelets is studied with an in vitro model using reflection contrast microscopy and an image analysis system. The adhesive feature is promoted by oxidatively modified low density lipoprotein, which also induces functional morphological changes of platelets. However, when washed platelets are pretreated with 0.05 mM cytochalasin D, oxidized low density lipoprotein (100 μg/ml) causes a slower increase of the adhesion area (11.6 μm2/min) compared to untreated platelets (15.7 μm2/min) or platelets treated by oxidized low density lipoprotein alone (20.5 μm2/min, P〈0.01). These results are supported by light transmission analysis and by transmission electron microscopy. Our experiments suggest that cytochalasin D inhibits the change of platelets in shape induced by oxidized low density lipoprotein, hinders the adhesion, but does not prevent the adhesion entirely.
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  • 30
    ISSN: 1432-0878
    Keywords: Nitric oxide synthase ; Vasoactive intestinal peptide ; Immunohistochemistry ; Electron microscopy ; Submucous plexus ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the submucous plexus of the guinea-pig ileum, previous light-microscopic studies have revealed that vasoactive intestinal peptide (VIP)-immunoreactive and nitric oxide synthase (NOS)-immunoreactive terminals are found predominantly in association with VIP-immunoreactive nerve cell bodies. In this study, double-label immunohistochemistry at the light-microscopic level demonstrated co-localization of NOS-immunoreactivity and VIP-immunoreactivity in axon terminals in submucous ganglia. About 90% of nerve fibres with NOS-immunoreactivity or VIP-immunoreactivity were immunoreactive for both antigens; only about 10% of labelled varicosities contained only NOS-immunoreactivity or VIP-immunoreactivity. The VIP/NOS varicosities were more often seen in the central parts of the ganglia, close to the VIP-immunoreactive cell bodies. Ultrastructural immunocytochemistry with antibodies to VIP was used to determine if NOS/VIP terminals synapse exclusively with VIP-immunoreactive nerve cell bodies. We examined the targets of VIP-immunoreactive boutons in two submucous ganglia from different animals. Serial ultrathin sections were taken through the ganglia after they had been processed for VIP immunocytochemistry. For each cell body, the number of VIP inputs (synapses and close contacts) was determined. The number of VIP-immunoreactive synapses received by the cell bodies of submucous neurons varied from 0–4 and the number of VIP-immunoreactive close contacts varied from 3–10. There was no significant difference between VIP-immunoreactive nerve cell bodies and non-VIP nerve cell bodies in the number of VIP-immunoreactive synapses and close contacts they received. Thus, the implication from light microscopy that NOS/VIP terminals end predominantly on VIP nerve cells was not vindicated by electron microscopy.
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  • 31
    ISSN: 1432-0878
    Keywords: CD44, adhesion molecule ; Bone ; Osteoclasts ; Osteocytes ; Immunohistochemistry ; Confocal laser scanning microscopy ; Electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract CD44 is a multifunctional adhesion molecule that binds to hyaluronic acid, type I collagen, and fibronectin. We have studied the immunohistochemical localization of CD44 in bone cells by confocal laser scanning microscopy and transmission electron microscopy in order to clarify its role in the cell-cell and/or cell-matrix interaction of bone cells. In round osteoblasts attached to bone surfaces, immunoreactivity is restricted to their cytoplasmic processes. On the other hand, osteocytes in bone matrices show intense immunoreactivity on their plasma membrane. Intense immunoreactivity for CD44 can be detected on the basolateral plasma membranes of osteoclasts. There is considerably less reactivity observed in the area of the plasma membrane that is in direct contact with bone. The pre-embedding electron-microscopical method has revealed that CD44 is mainly localized on the basolateral plasma membrane of osteoclasts. However, the ruffled border and clear zone show little immunoreactivity. A CD44-positive reaction can be detected on both plasma membranes in the contact region between osteoclasts and osteocytes. These findings suggest that: 1) cells of the osteoblast lineage express CD44 in accordance with their morphological changes from osteoblasts into osteocytes; 2) osteoclasts express CD44 on their basolateral plasma membrane; 3) CD44 in osteoclasts and osteocytes may play an important role in cell-cell and/or cell-matrix attachment via extracellular matrices.
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  • 32
    ISSN: 1432-0878
    Keywords: Nitric oxide synthase ; Coronary vasculature ; Electron microscopy ; Immunocytochemistry Rat (sprague Dawley) ; Guinea-pig (Dunkin Hartley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Ultrastructural investigation of nitrix oxide synthase-immunoreactive nerves closely associated with blood vessels in rat and guinea-pig hearts revealed many labelled nerve fibres in the walls of the main branches of the coronary arteries, and in arterioles, capillaries and post-capillary venules. The number of nitric oxide synthase-containing nerve fibres associated with different vessels, even those of the same calibre, varied. Terminal regions of nitric oxide synthase-immunoreactive fibres were observed in the endocardium and myocardium. Nitric oxide synthase-labelled fibres displayed electrondense immunoproduct in both varicose and intervaricose regions. Immunoreactive axonal varicosities contained both small and large synaptic vesicles. The characteristics of the nitric oxide synthase-immunoreactive nerve fibres observed in the heart and the possibility that these fibres represent the processes of intracardiac neurones and/or sensory neurones of extrinsic origin are discussed.
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  • 33
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 281 (1995), S. 69-76 
    ISSN: 1432-0878
    Keywords: Periodic lamellar granule ; Primary granule ; Chronic myeloproliferative disorder ; Neutrophils ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Granules consisting of periodically arranged membranous lamellae and amorphous electron-opaque material, i.e., periodic lamellar granules, are present in human neutrophils. To date, no extensive ultrastructural studies have been carried out on these granules because of their infrequent presence in neutrophils. The bone marrow of 18 cases of chronic myeloproliferative disorders, including one case of chronic neutrophilic leukemia in which periodic lamellar granules were frequently seen in neutrophils, was investigated by electron microscopy. Periodic lamellar granules were seen in neutrophils in 12 of the 18 cases at varying frequencies. They were preferentially seen in immature neutrophils. The transverse profiles of these granules revealed concentric complete/incomplete rings or periodic parallel straight lines, i.e., various patterns of lamellar arrangement were present. Periodic lamellar granules were positive for myeloperoxidase and lysozyme at the electron-microscopic level. These results suggest that these granules represent a primary neutrophil granule subtype. However, their functional and pathologic significance remains unknown.
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  • 34
    ISSN: 1432-0878
    Keywords: Key words: Ellipsoids ; Spleen ; Electron microscopy ; Fluorescent microspheres ; Oncorhynchus mykiss (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The ultrastructure of ellipsoids in the spleen of rainbow trout (Oncorhynchus mykiss) is described. The endothelium of terminations of arterioles bulged into the lumen, and gaps between the endothelial cells were evident. A continuous basal lamina was not present, and there were extensive interdigitations between the endothelial cells and surrounding reticular cells. The interdigitating processes were rich in microfilaments. Intravenously injected colloidal carbon, approximately 0.03 μm in diameter, was held in the reticular matrix of the ellipsoidal wall and taken up by macrophages that extended cellular processes among the reticular and endothelial cells. The intravenous injection of fluorescent polystyrene microspheres of known diameter showed that microspheres with a diameter of 0.5 or 1.0 μm were localised in the red pulp, whereas microspheres with a diameter of 0.15 μm were retained in ellipsoidal walls. Thus, the terminations of splenic arterioles in rainbow trout were found to be consistent with descriptions of ellipsoids in other vertebrates in that they possessed a specialised cuboidal endothelium, lacked a continuous basal lamina, were surrounded by a sheath of macrophages and reticular cells, and had a role in the selective filtration and retention of blood-borne particles.
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  • 35
    ISSN: 1432-0878
    Keywords: Lateral heart nerve ; FMRFamide ; Allatostatin ; Coexistence ; Mirror-section ; Axosomatic synapses ; Electron microscopy ; Periplaneta americana (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Both allatostatin immunoreactivity (AS-IR) and FMRFamide immunoreactivity (FMRFa-IR) have been demonstrated light-microscopically in the lateral heart nerve of Periplaneta americana. The identifical labeling of some fibers suggests the coexistence of the two antigens. Electron-microscopically, six granule types in the peripheral part of the lateral heart nerve can be distinguished according to their size and density (types 1–6). These granule types can be subdivided immunocytochemically by means of a new mirror-section technique. Granules of types 4 and 5 always exclusively show FMRFa-IR. In the populations of fibers containing granules of types 1 and 6, axon profiles can be found that contain granules colocalizing FMRFa-IR and AS-IR. Other axon profiles of these populations only contain immunonegative granules of the same ultrastructure. Granules of type 2 can be differentiated immunocytochemically in three forms in the same section: In some fibers, they are nonreactive; in other fibers of the same section, they show FMRFa-IR, whereas in a third fiber type, granules show AS-IR. Finally, granules of type 3 can be observed with FMRFA-IR. In other fibers, they occur with the same ultrastructure but exhibit no immunoreactivity. Two soma types occur in the lateral heart nerve. Soma type I is characterized by the production of electron-dense granules that show FMRFa-IR. Type II is in close contact with various fibers, forming different types of axosomatic synapses, hitherto unknown in Insecta.
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  • 36
    ISSN: 1432-0878
    Keywords: Suprachiasmatic nucleus ; Catecholamines ; Dopamine ; Electron microscopy ; Vasoactive intestinal peptide ; Vasopressin ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Catecholaminergic fibers in the suprachiasmatic nucleus of adult rats were investigated by use of light- and electron-microscopic immunocytochemistry. The suprachiasmatic nucleus receives a modest density of tyrosine hydroxylase-containing axons, homogeneously distributed in the nucleus and forming varicosities throughout its entire rostro-caudal extension. Immunolabeling with antibodies against dopamine showed that this catecholamine input comprises a dopaminergic component. Many tyrosine hydroxylase-positive cells were localized at the immediate periphery of the suprachiasmatic nucleus. With electron-microscopic examination, dendrites of these neurons were found within the limits of the nucleus as well as at a border zone between the suprachiasmatic nucleus proper and the optic tract where they received unlabeled synapses, providing a morphological support for a possible role of dopaminergic neurons in the integration and/or transfer of light-related signals. More than 91% of catecholaminergic axonal varicosities were found to establish morphologically defined synapses with dendrites. To investigate whether these synapses might be shared with neurons of one or both of the two main peptidergic populations of the nucleus, namely vasoactive intestinal peptide- and vasopressin-containing neurons, we carried out doublelabeling experments combining immunoperoxidase and immunogold-silver labeling. Results showed only a few cases of direct association of the catecholaminergic terminals with these peptidergic categories. In both types of dually stained sections, catecholaminergic synapses were preferentially made with unlabeled dendrites. The homogeneous distribution of tyrosine hydroxylase-immunoreactive fibers in the suprachiasmatic nucleus could therefore reflect a lack of significant catecholaminergic innervation of both vasoactive intestinal peptide- and vasopressin-synthesizing neurons.
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  • 37
    ISSN: 1432-0878
    Keywords: Pituitary ; Gonadotrops ; Crinophagy ; Electron microscopy ; Enzyme cytochemistry ; Immunocytochemistry ; Autoradiography ; Catfish, Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radiolabelling with tritiated amino acids followed by autoradiography demonstrated that globules received radioactive material after secretory granules. The latter received radioactive material within 75 min of administration of radioactive amino acids but globules and irregular masses did not. Although some globules became radioactively labelled within 24 h of the administration of radioactive amino acids, irregular masses remained unlabelled during this period. Secretory granules reacted positively with antisera against α and β gonadotropin subunits, whereas globules and irregular masses only reacted with the antiserum against the β subunit. A moderate anti-7B2 immunoreactivity was demonstrated in secretory granules and globules, whereas irregular masses labelled strongly. The combined cytological results indicate that globules and irregular masses are degradative, possibly crinophagic structures which develop by fusional events from secretory granules to globules and then to irregular masses.
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  • 38
    ISSN: 1432-0878
    Keywords: Key words: Pituitary ; Gonadotrops ; Crinophagy ; Electron microscopy ; Enzyme cytochemistry ; Immunocytochemistry ; Autoradiography ; Catfish ; Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radiolabelling with tritiated amino acids followed by autoradiography demons trated that globules received radioactive material after secretory granules. The latter received radioactive material within 75 min of administration of radioactive amino acids but globules and irregular masses did not. Although some globules became radioactively labelled within 24 h of the administration of radioactive amino acids, irregular masses remained unlabelled during this period. Secretory granules reacted positively with antisera against α and β gonadotropin subunits, whereas globules and irregular masses only reacted with the antiserum against the β subunit. A moderate anti-7B2 immunoreactivity was demonstrated in secretory granules and globules, whereas irregular masses labelled strongly. The combined cytological results indicate that globules and irregular masses are degradative, possibly crinophagic structures which develop by fusional events from secretory granules to globules and then to irregular masses.
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  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 280 (1995), S. 183-188 
    ISSN: 1432-0878
    Keywords: Key words: Blood platelets ; Oxidized LDL ; Cytochalasin D ; Reflection contrast microscopy ; Image analysis ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The adhesion of human blood platelets is studied with an in vitro model using reflection contrast microscopy and an image analysis system. The adhesive feature is promoted by oxidatively modified low density lipoprotein, which also induces functional morphological changes of platelets. However, when washed platelets are pretreated with 0.05 mM cytochalasin D, oxidized low density lipoprotein (100 μg/ml) causes a slower increase of the adhesion area (11.6 μm2/min) compared to untreated platelets (15.7 μm2/min) or platelets treated by oxidized low density lipoprotein alone (20.5 μm2/min, P〈0.01). These results are supported by light transmission analysis and by transmission electron microscopy. Our experiments suggest that cytochalasin D inhibits the change of platelets in shape induced by oxidized low density lipoprotein, hinders the adhesion, but does not prevent the adhesion entirely.
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  • 40
    ISSN: 1432-0878
    Keywords: Key words: Suprachiasmatic nucleus ; Catecholamines ; Dopamine ; Electron microscopy ; Vasoactive intestinal peptide ; Vasopressin ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Catecholaminergic fibers in the suprachiasmatic nucleus of adult rats were investigated by use of light- and electron-microscopic immunocytochemistry. The suprachiasmatic nucleus receives a modest density of tyrosine hydroxylase-containing axons, homogeneously distributed in the nucleus and forming varicosities throughout its entire rostro-caudal extension. Immunolabeling with antibodies against dopamine showed that this catecholamine input comprises a dopaminergic component. Many tyrosine hydroxylase-positive cells were localized at the immediate periphery of the suprachiasmatic nucleus. With electron-microscopic examination, dendrites of these neurons were found within the limits of the nucleus as well as at a border zone between the suprachiasmatic nucleus proper and the optic tract where they received unlabeled synapses, providing a morphological support for a possible role of dopaminergic neurons in the integration and/or transfer of light-related signals. More than 91% of catecholaminergic axonal varicosities were found to establish morphologically defined synapses with dendrites. To investigate whether these synapses might be shared with neurons of one or both of the two main peptidergic populations of the nucleus, namely vasoactive intestinal peptide- and vasopressin-containing neurons, we carried out double-labeling experiments combining immunoperoxidase and immunogold-silver labeling. Results showed only a few cases of direct association of the catecholaminergic termin als with these peptidergic categories. In both types of dually stained sections, catecholaminergic synapses were preferentially made with unlabeled dendrites. The homogeneous distribution of tyrosine hydroxylase-immunoreactive fibers in the suprachiasmatic nucleus could therefore reflect a lack of significant catecholaminergic innervation of both vasoactive intestinal peptide- and vasopressin-synthesizing neurons.
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  • 41
    ISSN: 1432-0878
    Keywords: Key words: Thyro-parathyroidectomy ; Parathyroidectomy ; Enamel formation ; Light microscopy ; Electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The effects of thyro-parathyroidectomy, parathyroidectomy or thyroidectomy upon enamel formation in the rat incisor were studied. One control group and four groups of surgically treated rats were used: parathyroid autotransplanted, thyroidectomized, parathyroidectomized, and thyro-parathyroidectomized. One month after surgery, the incisors were processed for light and electron microscopy. The present study revealed perturbations of the Tomes’ process morphology, of the rod pattern in the inner enamel formation, of the enamel surface, and of the mineralization after thyro-parathyroidectomy. After parathyroidectomy, only mineralization defects could be visualised. No effects were observed in enamel after thyroidectomy. A severe hypocalcemic state as seen in thyro-parathyroidectomized rats affects the enamel shape, and mineralization, and the morphology and function of secretory ameloblasts. Knowledge of the way in which the alteration of the enamel surface is produced should contribute to a better understanding of the development of tooth enamel.
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  • 42
    ISSN: 1432-0878
    Keywords: Meninges ; Cerebrospinal fluid ; Electron microscopy ; Aging ; Multilamellar bodies ; Surfactant ; Goldfish ; Carassius auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the optic tectum of goldfish, the outer, middle and inner layers of the endomeninx were evident in animals ranging in age from 1 month to several years. The outer layer in young animals consisted of closely overlapping cells with intertwined processes, whereas in the older animals it contained large extracellular spaces. The intermediate layer cells were always arranged in a single continuous layer, but in young animals they overlapped extensively with one another toward their edges whereas in the oldest animals they became extremely flat and non-overlapping. The inner layer included an outer tier of cells with their bases adhering to the intermediate layer, and an inner tier of cells detached from both the intermediate layer and the basal lamina overlying the brain parenchyma. Inner layer cells contained many large vacuoles that were in continuity with the extracellular space. With age, the extracellular space and the vacuolar system expanded, and the inner layer evolved into a meshwork of attenuated cytoplasmic processes embedded in the granular extracellular matrix. Another age-related feature was the accumulation adjacent to the basal lamina of uniform disc-shaped membranous structures, resembling multilamellar bodies of lung surfactant. These “disc bodies” were apparently generated by the coalescence of vesicles formed at the surface of the inner layer cells, possibly as a by-product of protein secretion by these cells.
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  • 43
    ISSN: 1432-0878
    Keywords: Key words: Nitric oxide synthase ; Vasoactive intestinal peptide ; Immunohistochemistry ; Electron microscopy ; Submucous plexus ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In the submucous plexus of the guinea-pig ileum, previous light-microscopic studies have revealed that vasoactive intestinal peptide (VIP)-immunoreactive and nitric oxide synthase (NOS)-immunoreactive terminals are found predominantly in association with VIP-immunoreactive nerve cell bodies. In this study, double-label immunohistochemistry at the light-microscopic level demonstrated co-localization of NOS-immunoreactivity and VIP-immunoreactivity in axon terminals in submucous ganglia. About 90% of nerve fibres with NOS-immunoreactivity or VIP-immunoreactivity were immunoreactive for both antigens; only about 10% of labelled varicosities contained only NOS-immunoreactivity or VIP-immunoreactivity. The VIP/NOS varicosities were more often seen in the central parts of the ganglia, close to the VIP-immunoreactive cell bodies. Ultrastructural immunocytochemistry with antibodies to VIP was used to determine if NOS/VIP terminals synapse exclusively with VIP-immunoreactive nerve cell bodies. We examined the targets of VIP-immunoreactive boutons in two submucous ganglia from different animals. Serial ultrathin sections were taken through the ganglia after they had been processed for VIP immunocytochemistry. For each cell body, the number of VIP inputs (synapses and close contacts) was determined. The number of VIP-immunoreactive synapses received by the cell bodies of submucous neurons varied from 0–4 and the number of VIP-immunoreactive close contacts varied from 3–10. There was no significant difference between VIP-immunoreactive nerve cell bodies and non-VIP nerve cell bodies in the number of VIP-immunoreactive synapses and close contacts they received. Thus, the implication from light microscopy that NOS/VIP terminals end predominantly on VIP nerve cells was not vindicated by electron microscopy.
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  • 44
    ISSN: 1432-0878
    Keywords: Key words: CD44 ; adhesion molecule ; Bone ; Osteoclasts ; Osteocytes ; Immunohistochemistry ; Confocal laser scanning microscopy ; Electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. CD44 is a multifunctional adhesion molecule that binds to hyaluronic acid, type I collagen, and fibronectin. We have studied the immunohistochemical localization of CD44 in bone cells by confocal laser scanning microscopy and transmission electron microscopy in order to clarify its role in the cell-cell and/or cell-matrix interaction of bone cells. In round osteoblasts attached to bone surfaces, immunoreactivity is restricted to their cytoplasmic processes. On the other hand, osteocytes in bone matrices show intense immunoreactivity on their plasma membrane. Intense immunoreactivity for CD44 can be detected on the basolateral plasma membranes of osteoclasts. There is considerably less reactivity observed in the area of the plasma membrane that is in direct contact with bone. The pre-embedding electron-microscopical method has revealed that CD44 is mainly localized on the basolateral plasma membrane of osteoclasts. However, the ruffled border and clear zone show little immunoreactivity. A CD44-positive reaction can be detected on both plasma membranes in the contact region between osteoclasts and osteocytes. These findings suggest that: 1) cells of the osteoblast lineage express CD44 in accordance with their morphological changes from osteoblasts into osteocytes; 2) osteoclasts express CD44 on their basolateral plasma membrane; 3) CD44 in osteoclasts and osteocytes may play an important role in cell-cell and/or cell-matrix attachment via extracellular matrices.
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  • 45
    ISSN: 1432-0878
    Keywords: Key words: Nitric oxide synthase ; Coronary vasculature ; Electron microscopy ; Immunocytochemistry ; Rat (Sprague Dawley) ; Guinea-pig (Dunkin Hartley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Ultrastructural investigation of nitric oxide synthase-immunoreactive nerves closely associated with blood vessels in rat and guinea-pig hearts revealed many labelled nerve fibres in the walls of the main branches of the coronary arteries, and in arterioles, capillaries and post-capillary venules. The number of nitric oxide synthase-containing nerve fibres associated with different vessels, even those of the same calibre, varied. Terminal regions of nitric oxide synthase-immunoreactive fibres were observed in the endocardium and myocardium. Nitric oxide synthase-labelled fibres displayed electron-dense immunoproduct in both varicose and intervaricose regions. Immunoreactive axonal varicosities contained both small and large synaptic vesicles. The characteristics of the nitric oxide synthase-immunoreactive nerve fibres observed in the heart and the possibility that these fibres represent the processes of intracardiac neurones and/or sensory neurones of extrinsic origin are discussed.
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  • 46
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    Cell & tissue research 281 (1995), S. 69-76 
    ISSN: 1432-0878
    Keywords: Key words: Periodic lamellar granule ; Primary granule ; Chronic myeloproliferative disorder ; Neutrophils ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Granules consisting of periodically arranged membranous lamellae and amorphous electron-opaque material, i.e., periodic lamellar granules, are present in human neutrophils. To date, no extensive ultrastructural studies have been carried out on these granules because of their infrequent presence in neutrophils. The bone marrow of 18 cases of chronic myeloproliferative disorders, including one case of chronic neutrophilic leukemia in which periodic lamellar granules were frequently seen in neutrophils, was investigated by electron microscopy. Periodic lamellar granules were seen in neutrophils in 12 of the 18 cases at varying frequencies. They were preferentially seen in immature neutrophils. The transverse profiles of these granules revealed concentric complete/incomplete rings or periodic parallel straight lines, i.e., various patterns of lamellar arrangement were present. Periodic lamellar granules were positive for myeloperoxidase and lysozyme at the electron-microscopic level. These results suggest that these granules represent a primary neutrophil granule subtype. However, their functional and pathologic significance remains unknown.
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  • 47
    ISSN: 1432-0878
    Keywords: Key words: Blood platelets ; Immunocytochemistry ; Electron microscopy ; Coated vesicles ; Clathrin ; Adhesive proteins ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Coated membranes and vesicles play an important role in receptor-mediated endocytosis and intracellular trafficking in various cell types, and are also present in blood platelets. Platelets take up certain proteins from the blood plasma, such as von Willebrand factor and fibrinogen, and these substances are transferred to storage granules. The receptors for these plasma proteins on the platelet plasma membrane have been well characterized, but morphological evidence for their transport to the storage granules is not yet available. In an attempt to clarify this aspect, we employed postembedding immunocytochemistry on platelets embedded in the acrylic resin LR White. Clathrin as the major coat component of coated vesicles was localized in the cytoplasm, on the plasmic faces of α-granules and the open canalicular system, and on the plasmic face of the plasma membrane. Colocalizations of the adhesive proteins, von Willebrand factor, fibrinogen and fibronectin, with clathrin could be observed at the same typical locations as coated vesicles were seen in Araldite-embedded material. These colocalizations have not been reported to date and furnish further evidence for a coated vesicle-mediated transport of blood plasma-derived adhesive proteins from their receptors on the outer plasma membrane to the α-granules.
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  • 48
    ISSN: 1432-0878
    Keywords: Key words: Meninges ; Cerebrospinal fluid ; Electron microscopy ; Aging ; Multilamellar bodies ; Surfactant ; Goldfish ; Carassius auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In the optic tectum of goldfish, the outer, middle and inner layers of the endomeninx were evident in animals ranging in age from 1 month to several years. The outer layer in young animals consisted of closely overlapping cells with intertwined processes, whereas in the older animals it contained large extracellular spaces. The intermediate layer cells were always arranged in a single continuous layer, but in young animals they overlapped extensively with one another toward their edges whereas in the oldest animals they became extremely flat and non-overlapping. The inner layer included an outer tier of cells with their bases adhering to the intermediate layer, and an inner tier of cells detached from both the intermediate layer and the basal lamina overlying the brain parenchyma. Inner layer cells contained many large vacuoles that were in continuity with the extracellular space. With age, the extracellular space and the vacuolar system expanded, and the inner layer evolved into a meshwork of attenuated cytoplasmic processes embedded in the granular extracellular matrix. Another age-related feature was the accumulation adjacent to the basal lamina of uniform disc-shaped membranous structures, resembling multilamellar bodies of lung surfactant. These ”disc bodies” were apparently generated by the coalescence of vesicles formed at the surface of the inner layer cells, possibly as a by-product of protein secretion by these cells.
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  • 49
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    Cell & tissue research 279 (1995), S. 445-452 
    ISSN: 1432-0878
    Keywords: Key words: Estradiol receptor ; Breast cancer cells ; Cell culture ; Ultrastructure ; Electron microscopy ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The distribution of estradiol receptor in serial sections of estradiol-deprived and estradiol-stimulated MCF7 cells was studied by using mouse monoclonal antibodies reacting with different domains of the receptor and goat-antimouse IgG/6 nm gold. In the nucleus and the cytoplasm of estradiol-deprived cells, the receptor was detected by all three monoclonals (13H2, HT 65 and MA1-310). The antibodies 13H2 and MA1-310 detected receptor associated to the microfilament bundles in the cytoplasm. Higher densities of antireceptor attachment to the nuclear areas were accompanied by a reduction in the attachment to the cytoplasm after estradiol stimulation of the cells. The results confirm earlier observations on the presence of cytoplasmic estrogen receptor in estradiol-deprived cells and support the premise of an es- tradiol-induced translocation of this ligand-dependent transcription regulator.
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  • 50
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    Cell & tissue research 279 (1995), S. 445-452 
    ISSN: 1432-0878
    Keywords: Estradiol receptor ; Breast cancer cells ; Cell culture ; Ultrastructure ; Electron microscopy ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of estradiol receptor in serial sections of estradiol-deprived and estradiol-stimulated MCF7 cells was studied by using mouse monoclonal antibodies reacting with different domains of the receptor and goat-antimouse IgG/6 nm gold. In the nucleus and the cytoplasm of estradiol-deprived cells, the receptor was detected by all three monoclonals (13H2, HT 65 and MA1-310). The antibodies 13H2 and MA1-310 detected receptor associated to the microfilament bundles in the cytoplasm. Higher densities of antireceptor attachment to the nuclear areas were accompanied by a reduction in the attachment to the cytoplasm after estradiol stimulation of the cells. The results confirm earlier observations on the presence of cytoplasmic estrogen receptor in estradiol-deprived cells and support the premise of an estradiol-induced translocation of this ligand-dependent transcription regulator.
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  • 51
    ISSN: 1432-0878
    Keywords: Blood platelets ; Immunocytochemistry ; Electron microscopy ; Coated vesicles ; Clathrin ; Adhesive proteins ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Coated membranes and vesicles play an important role in receptor-mediated endocytosis and intracellular trafficking in various cell types, and are also present in blood platelets. Platelets take up certain proteins from the blood plasma, such as von Willebrand factor and fibrinogen, and these substances are transferred to storage granules. The receptors for these plasma proteins on the platelet plasma membrane have been well characterized, but morphological evidence for their transport to the storage granules is not yet available. In an attempt to clarify this aspect, we employed postembedding immunocytochemistry on platelets embedded in the acrylic resin LR White. Clathrin as the major coat component of coated vesicles was localized in the cytoplasm, on the plasmic faces of α-granules and the open canalicular system, and on the plasmic face of the plasma membrane. Colocalizations of the adhesive proteins, von Willebrand factor, fibrinogen and fibronectin, with clathrin could be observed at the same typical locations as coated vesicles were seen in Araldite-embedded material. These colocalizations have not been reported to date and furnish further evidence for a coated vesicle-mediated transport of blood plasma-derived adhesive proteins from their receptors on the outer plasma membrane to the α-granules.
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  • 52
    ISSN: 1432-0878
    Keywords: Ellipsoids ; Spleen ; Electron microscopy ; Fluorescent microspheres ; Oncorhynchus mykiss (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The ultrastructure of ellipsoids in the spleen of rainbow trout (Oncorhynchus mykiss) is described. The endothelium of terminations of arterioles bulged into the lumen, and gaps between the endothelial cells were evident. A continuous basal lamina was not present, and there were extensive interdigitations between the endothelial cells and surrounding reticular cells. The interdigitating processes were rich in microfilaments. Intravenously injected colloidal carbon, approximately 0.03 μm in diameter, was held in the reticular matrix of the ellipsoidal wall and taken up by macrophages that extended cellular processes among the reticular and endothelial cells. The intravenous injection of fluorescent polystyrene microspheres of known diameter showed that microspheres with a diameter of 0.5 or 1.0 μm were localised in the red pulp, whereas microspheres with a diameter of 0.15 μm were retained in ellipsoidal walls. Thus, the terminations of splenic arterioles in rainbow trout were found to be consistent with descriptions of ellipsoids in other vertebrates in that they possessed a speciallised cuboidal endothelium, lacked a continuous basal lamina, were surrounded by a sheath of macrophages and reticular cells, and had a sheath of macrophages and reticular cells, and had a role in the selective filtration and retention of bloodborne particles.
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  • 53
    ISSN: 1432-0878
    Keywords: Spermatozoa ; Acrosome ; Thiols ; Disulphides ; Electron microscopy ; Monomaleimido nanogold ; Macropus eugenii (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This study utilised a commercially available monomaleimido-nanogold reagent to directly label cellular thiol groups (SH) of marsupial (tammar wallaby) spermatozoa before and after reduction of disulphides (S-S) with mercaptoethylamine hydrochloride (MEA). The sperm surface, mitochondrial membranes, axoneme and tail fibres were all labelled with gold particles before MEA treatment and the label intensity was increased after S-S reduction. The acrosomal membranes and matrix of spermatozoa contained no detectable SH prior to MEA treatment. However, after moderate MEA treatment (1 mg/ml) gold label was associated with the acrosomal membrane and invaginated acrosomal membrane within the acrosomal matrix. After exposure to 5 and 10 mg/ml MEA, gold particles heavily labelled the acrosomal matrix. Thus, the acrosomal membranes and matrix of tammar wallaby spermatozoa both contain S-S cross-linked structures, and this may contribute to the unusual stability of the marsupial acrosome. Under all treatment conditions the nucleus remained unlabelled. This is consistent with early studies which indicated that cysteine was absent from the nuclear protamines. The study also demonstrated that monomaleimido-nanogold can be used to resolve SH- and S-S-rich cellular structures directly, in addition to its use to label antibodies and Fab fragments for immunochemical localisation.
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  • 54
    ISSN: 1432-0878
    Keywords: Key words: Somatotrophs ; Growth hormone ; Growth hormone-releasing factor ; Secretory granule ; Electron microscopy ; Morphometry ; Rat (Fischer 344)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The anterior pituitary tissue of male rats injected with growth hormone-releasing factor (GRF) was either processed for stereology at the light- and electron-microscopic levels, or homogenized for growth hormone (GH) assay 2–60 min after GRF injection. Secretory granules of somatotrophs became smaller but increased in numerical density 2 min after GRF injection. Their volume density began to increase at 5 min. The frequency of exocytosis of the granules was most prominent as early as 2 min after GRF injection and reduced thereafter. GH levels in the tissue were lowest at 2–5 min, and returned to the control value by 60 min. Serum GH levels were highest at 15 min; even at 60 min, this value was higher than in the controls. These findings suggest that secretory granules in somatotrophs are stimulated to divide by GRF, resulting in a decrease in size and an increase in number. The discrepancy between the earlier formation of new secretory granules and the later restoration of intracellular GH levels implies that GRF first stimulates the synthesis of constituents of granules other than GH, and only later the synthesis of GH, and that newly formed small secretory granules contain less GH. From the clearance rate of serum GH and the frequency of granule exocytosis, it can be estimated that about a half million granules are released to maintain 1 ng/ml of serum GH in rats.
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  • 55
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    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 239-243 
    ISSN: 1434-4726
    Keywords: Homograft auditory ossicles ; Preservative solutions ; Shelf life ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructure of preserved ossicles at different shelf lives was compared. Homograft ossicles were harvested and preserved in 70% alcohol, 1:5000 Cialit (sodium-2-ethyl-mercuri-mercapto-benzoxazole-5-carboxylate), and buffered 4% formaldehyde at pH 7. The ultrastructure of each ossicle was studied by both scanning and transmission electron microscopy and was compared to that of fresh controls placed in 0.9 N saline solution. The results indicated clearly the superiority of 70% alcohol as a long-term preservative and 1:5000 Cialit as a short-term preservative.
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  • 56
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    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 469-474 
    ISSN: 1434-4726
    Keywords: Reinke's laryngeal edema ; Electron microscopy ; Immunohistochemistry ; Pathogenesis Neobursa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Light microscopy of vocal cord mucosa in patients with Reinke's edema revealed highly ramified fissured spaces in the subepithelial tissue that were generally lined with flat cells. The ultrastructure of the parietal cells resembled fibroblasts whose cytoplasmic extensions overlapped in two to three layers in some places. Cell contacts were not observed. Neither electron microscopy nor immunohistochemical testing with antibody against laminin demonstrated a basal membrane. It was possible to distinguish between light and dark cells in the specimens examined. The cytoplasm of the light cells contained intermediate filaments, mitochondria, lysosomes, coated vesicles, caveolae and broad cisternae of rough endoplasmic reticulum. The dark cells were more numerous and typically exhibited a well-developed endoplasmic reticulum and free ribosomes. The parietal cells showed no immunoreaction against human vascular endothelial cells. Immunohistochemical demonstration of mesenchymal intermediate filaments using antibody against vimentin yielded a positive reaction for some of the cells in the walls of the crevices and subepithelial tissue. It was also possible to demonstrate a few cells with monoclonal antibody against macrophages (KiM6). These findings contradict the concept of lymphatic distension in cases of Reinke's edema. Since the parietal cells seen resembled synoviocytes in their structure and immunohistochemical reactions, findings indicate that the hollow spaces of Reinke's edema develop like neobursae from mechanical strain.
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  • 57
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    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 229-235 
    ISSN: 1434-4726
    Keywords: Larynx ; Neuroendocrine carcinoma ; Carcinoid tumor ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Carcinoid tumors belong to the group of neuroendocrine tumors of epithelial origin, i.e., neuroendocrine carcinomas. These neoplasms usually occur in the gastrointestinal tract or bronchial system but are very rare neoplasms in the larynx. Since carcinoid tumors in this latter site may appear to be undifferentiated by light microscopy, they may possibly be misinterpreted and their neuroendocrine characteristics may remain unrecognized. Using immunohistochemical methods, three carcinoid tumors were studied and showed positive immunostaining for markers of epithelial origin (cytokeratins, epithelial membrane antigen, carcino-embryonic antigen) and, in particular, for markers of neuroendocrine differentiation (chromogranin, synaptophysin, neuron-specific enolase). All tumors expressed calcitonin-, serotonin- and adrenocorticotropic-hormone-like immunoreactivity. In contrast, three poorly differentiated squamous cell carcinomas showed positive immunostaining for epithelial markers but did not show any immunoreactivity with markers of endocrine characteristics. Fine structurally, carcinoid tumor cells contained neurosecretory-type granules scattered throughout the cytoplasm. The present study demonstrated that (1) carcinoid tumors of the larynx possess distinct immunohistochemical characteristics that allow a clear classification, (2) it is advisable to use a battery of primary antibodies rather than rely on specificity and sensitivity of a single marker to establish diagnosis and (3) the fine structural demonstration of neurosecretory-type granules serves as a reliable adjunct to diagnosis.
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  • 58
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    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 53-56 
    ISSN: 1434-4726
    Keywords: Parotid gland ; Amyloidosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of an organ-limited amyloid tumor of the left parotid gland is described with a history of recurrence. A slowly growing parotid mass was the only symptom. After 5.5 years following local excision, the patient was readmitted with a slowly growing recurrence in the superficial lobe of the previously treated gland. Lateral parotidectomy was performed with wide excision of the infiltrated tissue and preservation of the facial nerve. Primary amyloidosis of the AL type was confirmed with immunohistochemical studies revealing staining for lambda but not kappa light chains of immunoglobulins. There has been no clinical or laboratory evidence of systemic amyloidosis or recurrence after 2 years. To the best of our knowledge, this is the first report of a recurrent amyloid tumor of the parotid gland.
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  • 59
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    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 249-254 
    ISSN: 1434-4726
    Keywords: Middle ear ; Glycoconjugate ; Wheat germ agglutinin ; Electron microscopy ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To evaluate the protective function of the mucous blanket (MB) against lectin substances, we examined at the ultrastructural level whether intraluminal colloidal gold-labelled wheat germ agglutinin (WGA) could enter the MB-covered epithelial cell surface of the guinea pig tubotympanic mucosa. Post-embedding staining with WGA/gold on thin tissue sections was done in parallel for comparison. The cell surface glycoconjugate of the eustachian tubal and transitional epithelium had a typical bilayered structure: the outer MB and the microvilli-associated glycocalyx (MAG), which were interposed by the interciliary fluid zone. In squamous epithelium of the distal middle ear, the MB adhered to the MAG, thereby forming a monolayered coat of glycoconjugates at the cell surface. In the pre-embedding staining, WGA/gold did not bind with the MB and MAG in the eustachian tube, and exclusively bound with MB in the transitional area. Direct binding was also found with MAG and the apical plasmic membrane in the squamous epithelium. These findings indicate that MAG is occluded by MB lined with the interciliary fluid zone for luminal access of lectin at the proximal lumina of the tubotympanic epithelium. It is also suggested that MB existing at two sites possesses a different WGA-binding capacity: shielding as a “dust cover” in the eustachian tube and entrapping as a “flypaper” against lectin in the transitional area of the middle ear.
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  • 60
    ISSN: 1860-1499
    Keywords: Skin metastasis ; Adenocarcinoma ; Biliary system ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An 81-year-old Japanese man noticed red papules and subcutaneous tumors on his face and trunk about 2 months before entering our clinic. He had been suffering from biliary system cancer for about one year.Light microscopic findings: Tumor cells, which formed various-sized glands lined by columnar cells, were observed in the dermis and subcutaneous tissue.Electron microscopic findings: In tumor cells, intracytoplasmic lumina lined with microvilli were observed. Cell organelles, such as mitochondria and rough-surfaced endoplasmic reticulum, were relatively well-developed. From these findings, it seems that the characteristics of these tumor cells resemble those of the biliary system.
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  • 61
    ISSN: 1860-1499
    Keywords: Subarachnoid hemorrhage ; Calcium ; Cerebral vasospasm ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to clarify the relationship between calcium mobilization and morphological changes in the arterial wall after subarachnoid hemorrhage, electron microscopic histochemical assessments of the intracellular calcium in the arterial wall of human subjects showing vasospasm angiographically were conducted. Intracellular calcium ions in the arterial wall after subarachnoid hemorrhage were significantly more numerous than those of the control specimens. However, reaction products of calcium ions in the arterial wall were distributed mainly in the areas which morphologically revealed spastic changes such as myonecrosis and vacuoles, and there were no or extremely few reaction products of calcium ions in the areas showing no morphological changes in the arterial wall. These findings were consistent with the data for a feline model with experimental subarachnoid hemorrhage previously studied by the authors and indicated that increased intracellular calcium mobilization detected histochemically might be related to the morphological changes in the arterial wall after subarachnoid hemorrhage.
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  • 62
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    Medical molecular morphology 28 (1995), S. 45-49 
    ISSN: 1860-1499
    Keywords: Malignant fibrous histiocytoma ; Larynx ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Malignant fibrous histiocytoma (MFH) of the vocal cord occurring in a 46-year-old male was studied immunohistochemically and ultrastructurally. The tumor consisted of the two main areas, pleomorphic and storiform. Immunohistochemical staining was strongly positive for α1-antitrypsin and α1-antichymotrypsin, and negative for desmin, keratin, myoglobin, actin, carcinoembryonic antigen, and S100 protein. Ultrastructurally, this MFH consisted of four different types of cells which were either fibroblast-like, histiocyte-like, myofibroblast-like, or with features of both the fibroblast and histiocyte types. Transition forms between the four types of cells were also found. This suggests that cells of MFH are derived from the same undifferentiated stem cells.
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  • 63
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    Medical molecular morphology 28 (1995), S. 80-87 
    ISSN: 1860-1499
    Keywords: Endotoxin ; Inner ear ; Electron microscopy ; Inflammatory cell ; Stria vascularis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Escherichia coli-derived endotoxin was introduced into the middle ears of 10 guinea pigs 24 hr after intraperitoneal injection of the same endotoxin. The cochleae were removed 24 hr after the introduction of the endotoxin into the middle ears and observed by light and electron microscopy. Inflammatory cell infitration and bleeding were observed in both endolymphatic and perilymphatic spaces. Inflammatory cells also infiltrated the stria vascularis, spiral ligament, spiral prominence and the organ of Corti. Blood sludge was observed in almost all of the strial capillaries of the upper three turns, but in few of the basal turns. The hair cells were intact in every turn except for a small number of degenerated mitochondria. Intermediate cells of the stria vascularis were shrunken, and some of them showed degenerative changes. Marginal cells had also shrunken, but they were less shrunken than the intermediate cells. The shrinking of both cells caused the enlargement of the intercellular space of the stria vascularis.
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  • 64
    ISSN: 1860-1499
    Keywords: Adrenal medulla ; Ganglioneuroma ; Electron microscopy ; Ultrastructural study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Tissue samples of adrenal ganglioneuromas were obtained from two patients: 35- and 47-year-old males. Light microscopic studies showed that these tumors contained Schwann cells and ganglion cells. Electron microscopic examinations revealed numerous unmyelinated and myelinated axons surrounded by Schwann cells. The ganglion cells in the tumors had abundant organelles, such as well-developed cisternae of the rough endoplasmic reticulum, many profiles of the Golgi apparatus, mitochondria, lysosomes, microtubules and neurofilaments. Electron dense cored granules resembling catecholamine granules were present in the ganglion cell bodies and neural processes. These features resmebled those of normal sympathetic ganglion cells. It is concluded that adrenal ganglioneuroma originates from sympathetic ganglion tissue.
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  • 65
    ISSN: 1860-1499
    Keywords: Duchenne muscular dystrophy ; Fukuyama congenital muscular dystrophy ; Electron microscopy ; Myofiber degeneration and regeneration ; Muscle plasma membrane undercoat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Muscle plasma membrane undercoats were investigated by conventional electron microscopy in both Duchenne muscular dystrophy (DMD) and Fukuyama congenital muscular dystrophy (FCMD). The densities of the plasma membrane undercoats were rarefied in the parts of the plasma membranes overlying the degenerating focus in both DMD and FCMD myofibers. The degree of rarefaction tended to be parallel to the degree of degeneration in the myofibers. It was hard to distinguish the undercoat densities of normal-looking myofibers of DMD and FCMD muscles from those of control myofibers from histochemically-normal muscles. On the other hand, the undercoats of regenerating myofibers in DMD and FCMD muscles were denser than normal.
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  • 66
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    Medical molecular morphology 28 (1995), S. 137-145 
    ISSN: 1860-1499
    Keywords: Embryonal heart ; Formation of the cardiac vascular system ; Formation of the ventricular compact wall ; Corrosion cast ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The corrosion cast method for scanning electron microscopy, transmission electron microscopy and auto-injection of tracers for light microscopy were used to examine the cardiac coronary development and the forming of the ventricular compact wall to the embryonal sponge-work wall. Our observations suggest that the coronary artery first extends over outer layer, and later over middle and inner layers. As intertrabecular spaces are closed by fusion to each endocardium in the inner layer position, the veins are formed by the remaining expanded sinusoidal intertrabecular spaces. The capillaries of the coronary vessels are then connected to the veins to finally complete the cardiac vascular system.
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  • 67
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    Medical molecular morphology 28 (1995), S. 163-171 
    ISSN: 1860-1499
    Keywords: Neurocytoma ; Intraventricular tumor ; Electron microscopy ; Blood vessel ; Neurosecretory granule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of central neurocytoma was studied by electron microscopic and immunohistochemical methods. Immunohistochemical examinations showed the tumor cells to be positive for neuron-specific enolase, sporadically positive for synaptophysin, and negative for glial fibrillary acidic protein. The Ki-67 (MIB-1) positive index value for the tumor cells was a low 1.5%. Ultrastructurally, thin cytoplasmic processes of tumor cells showed differentiation to neuronal cells containing parallel bundles of microtubules and abortive synapses with dense core vesicles and/or clear vesicles. Microvessels composed of endothelial cells without fenestrations and tight junctions in the endothelial clefts appeared in fibrillary stromas as revealed by light microscopy. Neurosecretory granules in thin cell processes may have been secreted around microvessels.
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  • 68
    ISSN: 0003-276X
    Keywords: Human greater omentum ; Milky spots ; Macrophages ; Lymphocytes ; Light microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: Milky spots in the greater omentum of some animals are well organized perivascular infiltrated of leucocytes, and are considered to have characteristics of secondary lymphoid tissue. To determine whether milky spots in the human greater omentum can also be regarded as secondary lymphoid tissue, we studied milky spots in an unstimulated state.Methods: Patients were selected on the basis of absence of disease in the peritoneal cavity that might influence the state of the milky spots. Using monoclonel antibodies aganist macrophages, B-lymphocytes and T-lymphocytes, and immunoperoxidase labeling, the number of these cells and their location in milky spots were studied by light microscopy. However, the stromal components of the greater omentum, especially those within the milky spots, were studied by electron microscopy.Results: Milky spots in the human greater omentum are relatively uniform vascularized accumulations of mononuclear cells comprising macrophages (67.9% ± 9.4, mean ± standard deviation), B-cells (10.1% ± 3.4), T-cells (10.2% ± 3.7), and mast cells. However, no special B-cells and T-cell areas could be distinguished. On the ultrastructural level it was demonstrated that macrophages are present in different stages of maturation and can enter or leave the milky spots. Furthermore, no cells characteristic of secondary lymphoid organs, such as interdigitating cells or follicular dendritic cells, were seen.Conclusions: These data indicate that unstimulated milky spots in the human greater omentum are to a great extent just a preformed specific accumulation of primarily macrophages within the stroma of the greater omentum, and therefore, cannot be regarded as true secondary lymphoid tissue. Milky spots could serve as a gateway for, as well as a provider of pertioneal macrophages when the intra-abdominal status so requires.Finally, the data from this study are compard with the data of other studies of human milky spots and those in animals. © 1995 Wiley-Liss, Inc.
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  • 69
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    The @Anatomical Record 241 (1995), S. 487-495 
    ISSN: 0003-276X
    Keywords: Gut-associated lymphoid tissue ; Dome epithelium ; M cell ; Cecum ; Electron microscopy ; Horseradish peroxidase ; Rabbit ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The gut-associated lymphoid tissue of the rabbit cecum includes a single lymphoid patch located close to the ileocecal orifice. Vimentin immunoreactivity, which can now be regarded as a marker for M cells in rabbits, has identified a subpopulation of epithelial cells as M cells in the domes of this patch. The aim of the present study was to demonstrate that these M cells are capable of antigen transport and to characterize their ultrastructure.Methods: M cells of the rabbit cecal lymphoid patch were studied by scanning, thin section, and freeze-fracture electron microscopy. The transcytosis across these M cells was investigated using horseradish peroxidase as a soluble tracer protein.Results: The M cells were concentrated at the flanks of the domes and had long, thick, branched microvilli, a well-developed terminal web, and a deep invagination of their apical membrane. Numerous small vesicles lay beneath the terminal web in close vicinity to the base of the invagination. These vesicles transported the luminally applied horseradish peroxidase through the M cells. In contrast to adjacent enterocytes, the glycocalyx of M cells was thin, stub-like, and had very few glycocalyceal bodies. Bacteria adhered to the surface of M cells and were also found in the apical invagination.Conclusions: The M cells of the rabbit cecal lymphoid patch differ from those of Peyer's patches of the small intestine in their ultrastructure and route of antigen transport. These differences might be related to the situations resulting from differences in the microbial populations at these locations. © 1995 Wiley-Liss, Inc.
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  • 70
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    The @Anatomical Record 241 (1995), S. 563-578 
    ISSN: 0003-276X
    Keywords: Substantia nigra ; Basal ganglia ; Cytoarchitecture ; Light microscopy ; Electron microscopy ; Opossum ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The substantia nigra has been divided into three subdivisions. However, the cytoarchitecture of one of these subdivisions, the pars lateralis (SNI), has not been previously examined in detail at the light and electron microscopic levels in any species. In the adult opossum, the three nigral subdivisions can be easily distinguished as distinct, rostrocaudally oriented cell groups separated by neuron-free zones. Thus it was possible to determine the boundaries of the SNI unambiguously. This report covers the results of an examination of the morphology and organization of the SNI in the opossum.Methods: Material from 13 opossums was used for this study. Eight of the animals had been previously stained for Nissl substance (n=4) or impregnated by the Golgi technique (n=4). The remaining five animals were prepared for electron microscopic studies using standard procedures.Results: Two cell types were identified on the basis of morphological differences, small and medium-large neurons. Small neurons (10-18 μm long axis) have large nuclei with moderate amounts of heterochromatin and a thin rim of cytoplasm. They have long (up to 500 μm), spine-free dendrites. Medium-large neurons (18-54 μm long axis) have rounded nuclei with electron-lucent nucleoplasm. Few indentations of the nuclear envelope were observed. The surrounding cytoplasm has dense arrays of organelles. Nissl bodies are particularly prominent in the form of pyramids with their bases at juxtanuclear positions and their apices directed toward emerging dendrites. Dendrites of medium-large neurons are long (some〉1 mm in length), are primarily oriented in the frontal plane, and extend along the dorsal surface of or into the cerebral peduncle. Some cells have dendrites that are moderately spinous, whereas other neurons possess sparsely spinous dendrites. Relatively few synaptic profiles are observed to contact somata and proximal dendrites.Conclusion: This report provides added morphological support for the idea that the SNI is a distinct subdivision of the substantia nigra, a distinction previously made on the basis of the physiologically characterized relationship between the lateral substantia nigra and orienting behaviors and seizure-related function. © 1995 Wiley-Liss, Inc.
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  • 71
    ISSN: 0003-276X
    Keywords: Sheep ; Bone regeneration ; Osteogenic cell ; Endothelium ; Weibel-Palade-bodies ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The origin of osteoblasts is still controversial. Whereas several authors consider the stromal fibrablast of the bone marrow as the osteoprogenitor cell, others propose that the osteoblasts can be derived from the “capillary system.” The present study examines the replacement of tricalciumphosphate (TCP)-ceramic implanted into an artificial bone defect by newly formed bone. The results support the hypothesis that osteogenic cells can be derived from invading blood vessels.Methods: The spongiosa of the trochanter major of sheep was removed and the defect was filled with TCP-ceramic. Two months after surgery the ceramic implants together with the surrounding bone were removed and processed for transmission electron microscopy. Serial ultrathin sections of three newly formed osteons were examined.Results: The osteons contain one or two small sprouting capillaries, a peripheral layer of osteoblasts, and in between, a network of glycogen-rich cells. Some of the glycogen-rich cells are completely or partly surrounded by the endothelial basal lamina and are thereby characterized as pericytes. Weibel-Palade bodies, which are considered to be a marker of endothelial cells, were occasionally observed in glycogen-rich pericytes.Conclusions: Since pericytes differentiate into osteoblasts under in vivo and in vitro conditions, and have thus been regarded as osteoprogenitor cells, the presence of Weibel-Palade bodies in these cells suggest that osteogenic cells can be derived from endothelial cells. © 1995 Wiley-Liss, Inc.
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  • 72
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    The @Anatomical Record 242 (1995), S. 562-565 
    ISSN: 0003-276X
    Keywords: Rat ; Brain ; Microcirculation ; Development ; Pericyte ; Electron microscopy ; Gap junction ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: Fine structural study revealed the intercellular coupling between the pericyte and the endothelial cells via the gap junctions, in the capillaries of the basal forebrain of rat embryos.Results: Gap junctions were constructed by the adluminal plasmalemma of pericyte and the abluminal plasmalemma of endothelial cells.Conclusions: Gap junctions are membranous channels that directly join the cytoplasms of the pericyte and endothelial cell and imply some substantial role for the pericyte on the endothelial proliferation. It is postulated that the function of the pericyte in the prenatal mammals are assigned to the regulation of the development of cerebral microcirculation. © 1995 Wiley-Liss, Inc.
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  • 73
    ISSN: 0003-276X
    Keywords: Human lung ; Type II pneumocytes ; Lamellar bodies ; Surfactant ; Electron microscopy ; Morphometry ; Organ preservation ; Euro Collins solution ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: Pulmonary type II pneumocytes have been examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and morphometry in numerous mammals. Until now, the fine structure of the human type II pneumocyte has not been studied by means of morphometry.Methods: Eleven human donor lungs, which could not be made available for a suitable recipient, were preserved with Euro Collins solution (ECS) according to clinical organ preservation techniques. The lungs were fixed via the airways. Systematic random samples were analyzed by SEM, TEM, and classical stereological methods.Results: Type II pneumocytes showed normal fine structural characteristics. Morphometry revealed that although inter-individual variation due to some oedematous swelling was present, the cells were in a normal size range as indicated by an estimated mean volume of 763 ± 64 μm3. The volume densities were: nucleus 21.9 ± 2.2%, mitochondria 5.8 ± 0.9%, lamellar bodies 9.8 ± 3.6%, and remaining cytoplasmic components 62.4 ± 2.9% of the cell volume. Since the inter-individual variations in the volume densities referred to the cell may, to variable degrees, reflect the variation in the reference space, the volume densities referred to the constant test point system and the respective volume-to-surface ratios were used for interindividual comparisons. These parameters indicate that lamellar bodies were independent of cellular swelling, while mitochondria nucleus remaining cytoplasmic components increased in size with increasing cell size.Conclusions: Two to 7.5 hours of cold ischemia following ECS preservation do not deteriorate the fine structure of type II pneumocytes of human donor lungs. For reliable assessment of fine structural variation, morphometric parameters are required that are independent of variations in cell size. © 1995 Wiley-Liss, Inc.
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  • 74
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    The @Anatomical Record 243 (1995), S. 153-164 
    ISSN: 0003-276X
    Keywords: Conjunctiva ; Lymph follicles ; Lymph vessels ; Cynomolgus monkey ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: Knowledge of the structure of conjunctival lymph follicles is limited in comparison with those of other mucosa. Consequently a thorough morphological study of the follicles was undertaken to see if they are similar to others or whether they have any unique features and to provide an adequate background for future experimental studies.Methods: Normal lymphoid tissue of the conjunctiva of one side of nine young adult cynomologus monkeys was examined using a whole mount method and light and electron microscopy.Results: Only the peripheral tarsal and orbital regions of the upper and lower palpebral conjunctiva contained lymph follicles. Lymphocytes, reticulocytes, macrophages including tingible body macrophages, putative follicular dendritic cells, and plasmacytes were indentified in the follicles and M-cells were present in the follicle associated epithelium. High endothelial venules (HEV) displaying evidence consistent with lymphocyte extravasation were present in both primary and secondary follicles. A majority were secondary follicles with a germinal center composed largely of lymphoblasts. Mitoses were found in secondary follicles, mostly confined to the germinal centers, and they were numerous in many. Increased cell density and virtual elimination of intercellular space adjacent to some high endothelial venules suggested a possible association of these vessels with germinal center development. Chains of follicles were linked by lymph vessels, an approaching lymphatic dividing to embrace a follicle and recombining beyond it and passing to the next in line; many conjunctival follicles there-fore have both afferent and efferent lymphatics. The vessels were in direct contact with the follicle perimeters; lymph capillaries were not present within the substance of most follicles. Numerous valves indicated drainage radially from the tarsal conjunctiva then laterally or medially from the orbital conjunctiva through the follicle chains towards the nearest canthus.Conclusions: Conjunctival lymph follicles are fundamentally similar in structure to those found elsewhere in the body. However, the beads on a chain-like arrangement of lymph vessels and follicles may be unique. The possible association of HEV with follicle foramtion could be a general characteristic of mucosal follicles. ©1995 Wiley-Liss, Inc.
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  • 75
    ISSN: 0003-276X
    Keywords: Type VI collagen ; Mouse ; Masseter tendon ; Electron microscopy ; ATP treatment ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background and Methods: The association of masseter tendon type VI collagen with other extracellular matrix (ECM) components was examined from osseous attachment to myotendinous junction by immunohistochemistry and transmission electron microscopy with ATP treatment and enzyme digestion.Results: In the tendon proper, fibrocytes extended their processes among bundles of striated collagen fibrils and associated with adjacent cells through amorphous materials, thus forming a three-dimensional network. The amorphous or filamentous material was observed around the fibrocyte cell body and along the cell processes, where the localization of type VI collagen was confirmed by immunohistochemistry using anti-type VI collagen antibody. After treatment with 20 mM adenosine 5′-triphosphate (ATP), 100 nm periodic fibrils, an aggregated form of type VI collagen, were formed in the place where amorphous or filamentous material was present before the treatment. In myotendinous junction, the ATP-aggregated periodic fibrils were observed to associate with the external lamina of the muscle cells as well as among junctional tendon collagen fibrils. In the tendonbone boundary, ATP-aggregated periodic fibrils were observed around fibrocartilage-like cells in the uncalcifying area but not in the calcification front. Prolonged ATP treatment or hyaluronidase predigestion caused the formation of type VI collagen periodic fibrils in the area near the calcified matrix.Conclusions: The distribution of type VI collagen in mouse masseter tendon is different in different anatomical position. This may reflect the different functional demand for this collagen. © 1995 Wiley-Liss, Inc.
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  • 76
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    The @Anatomical Record 243 (1995), S. 438-448 
    ISSN: 0003-276X
    Keywords: Urinary bladder ; Vascular corrosion casting ; Electron microscopy ; Microvasculature ; Capillaries ; Pericytes ; Rabbit ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The urinary bladder requires a rich blood supply to maintain its functions, the storage and release of urine. Specialized properties of the bladder vasculature might be anticipated to ensure the integrity of this blood supply, because it is known that blood flow is reduced by distension during bladder filling. However, the bladder vasculature has been described in detail only at the gross level. A comprehensive, threedimensional view of the blood supply to the bladder wall is presented here.Methods: The microvasculature of the bladder of male New Zealand white rabbits was described using the combination of vascular corrosion casting, alkali digestion, light microscopy, and scanning and transmission electron microscopy. Following administration of an anticoagulant and an overdose of anesthetic, the abdominal aorta was cannulated just above the inferior mesenteric artery to permit flushing of the distal vasculature. The bladder vasculature was cleared of blood with buffered saline and then either perfuse-fixed with buffered 2% glutaraldehyde and sectioned, or filled with “Mercox” resin to prepare vascular corrosion casts. Casts were cleaned with NaOH, formic acid, and water. In some cases fixed bladders were partially digested with NaOH to expose the mucosal capillary plexus.Results: The bladder is supplied with blood by single, left and right vesicular branches of the internal or external iliac arteries. The serpentine vesicular arteries extend along the lateral borders of the bladder from base to apex just deep to the serosal surface and send dorsal and ventral branches to supply the dorsal and ventral bladder walls. Veins accompany the arteries and exhibit numerous valves. A very dense complex of vessels at the apex of the bladder apparently serves to accommodate bladder distension. The muscularis and submucosa contains few vessels, but the mucosa is well vascularized. An especially dense capillary plexus is present in the lamina propria at its junction with the transitional epithelium. In the relaxed bladder these capillaries lie in grooves formed by the basal layers of the epithelium. The endothelial cells of these capillaries display few cytoplasmic vesicles and are continuous or fenestrated. These capillaries are often invested with pericytes. The mucosal capillary plexus may be associated with an epithelial transport function or may be necessary for urothelial metabolism or maintenance of the barrier function of the urothelium. Unusual capillary tufts, possibly associated with vascular lymphatic tissue, are found associated with the main vessels on the lateral walls in the basal half of the bladder.Conclusions: These methods present a clear, comprehensive, three-dimensional view of the microvasculature of the bladder wall. They also identify several unique features of this vasculature and provide a basis for studies of the response of this vasculature to pathologic states and experimental manipulation. © 1995 Wiley-Liss, Inc.
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  • 77
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    The @Anatomical Record 243 (1995), S. 519-523 
    ISSN: 0003-276X
    Keywords: Hippocampal formation ; Mossy fibers ; Electron microscopy ; Granule cells ; Dense-core Vesicles ; Neuropeptide ; Rat ; Cholecystokinin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The possibility that mossy fiber endings in the rat hippocampal formation may contain cholecystokinin (CCK) was reexamined.Methods: For this, CCK-immunoreactivity was examined by light and electron microscopy using the avidin-biotin complex method.Results: At the light level, the topographical distribution of perikarya and processes with CCK-like immunoreactivity (CCK-LI) was similar to that previously described by others. Ultrastructural analysis of the dentate gyrus and CA3 region of the hippocampus revealed that some mossy fiber terminals contained CCK-LI most often affiliated with large, dense-core vesicles (DCV). Quantitative analysis revealed that 4-8% of the mossy terminal profiles examined (n = 350) contained CCK-labeled DCVs, which corresponded to 0.03-0.2 labeled DCVs per 100 μm2 of neuropil.Conclusions: The presence of CCK-LI within mossy fibers in the rat suggests that there is less species variability in peptide expression in this pathway than formerly believed. © 1995 Wiley-Liss, Inc.
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  • 78
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    Developmental Dynamics 204 (1995), S. 301-315 
    ISSN: 1058-8388
    Keywords: Chick ; Hindbrain ; Rhombomere ; Boundary ; Vimentin ; Chondroitin sulphate proteoglycan ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Hindbrain segments, rhom-bomeres, define distinct cellular and molecular domains which furnish the ground plan for important aspects of neural and cranial development. In this study, further evidence is presented that the interfaces between rhombomeres, rhombomere boundaries, contain both cells and extracellular matrix with specialised characteristics. Cells at rhombomere boundaries show temporally and spatially distinct expression patterns of developmentally important genes. Towards the end of the developmental period when rhombomeres are present, a fan-shaped array of cells at rhom-bomere boundaries, that constitute the ventricular ridge, shows decreased expression of two genes (Hoxb-1 and Krox-20), which earlier in development were expressed in all cells of specific rhombomeres. In contrast, these boundary cells show increased expression of another gene, Pax-6, which earlier in development has a rhombomere-specific expression pattern. A specialised identity for boundary cells is further suggested by increased labelling with an anti-vimentin antibody at rhombomere boundaries, indicating that at least some boundary cells are radial glia or glial precursors. In addition to distinct cellular properties, the extracellular domain at rhombomere boundaries is also specialised. Chondroitin sulphate proteoglycan (CSPG) immunoreactivity is increased and, as revealed by immuno-electron microscopy, localised to extracellular spaces. CSPG is also enriched in boundaries regenerated after ablation, or boundaries generated ectopically by rhombomere transplantation. We propose that rhombomere boundaries form their characteristic morphology at the interface between groups of cells with differing molecular characteristics, representing different cell states. A specialised band of cells then develops at the interface. Both the boundary cells and extracellular matrix have characteristics which could be important in later events of neural development such as axon guidance and cell migration. © 1995 wiley-Liss, Inc.
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  • 79
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    Developmental Dynamics 204 (1995), S. 391-405 
    ISSN: 1058-8388
    Keywords: Muscle development ; Innervation ; Secondary myotube ; Muscle architecture ; Electron microscopy ; Light microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This work examines the general principle of whether production of embryonic muscle fibres is invariably linked to sites of innervation, as we have previously reported in small rodent muscles (Duxson et al. [1989] Development 107:743-750). The experimental strategy has been to make a detailed electron microscopic analysis of the formation of new myotubes in a large muscle having multiple, discrete innervation zones. The particular model system is the guinea pig sternomastoid muscle, a strap-like, parallel-fibred muscle with four distinct endplate bands, both in the embryo and the adult. Primary myotubes in the developing muscle extended from tendon to tendon of the muscle and were innervated at each of the multiple endplate zones. Each point of innervation of the primary myotubes was a focus around which many new secondary myotubes formed, and each secondary myotube was approximately centred on one of the innervation sites of its supporting primary myotube. This confirms our previous report, in rat IVth lumbrical muscle, of an invariable association between sites of formation of new secondary myotubes and sites of innervation. We suggest that, in vivo, nerve terminals either directly induce the initial myoblast fusions which give rise to new secondary myotubes, or induce some precondition for fusion. An alternative hypothesis is that a common patterning influence in the muscle localizes both innervation and secondary myotube formation to the same zone. The pattern of secondary myotube production in the embryo has important implications for the size and final architecture of muscles in larger animals, and some of these are discussed. © 1995 wiley-Liss, Inc.
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  • 80
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    Microscopy Research and Technique 31 (1995), S. 234-247 
    ISSN: 1059-910X
    Keywords: Immunolocalisation ; Electron microscopy ; Ultrastructure ; hSP ; pS2 ; TFG α ; EGFR ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The trefoil peptides pS2 and human spasmolytic peptide are putative growth factors, particularly associated with mucus-producing cells of the gastrointestinal tract including those of the stomach. The receptor for transforming growth factor alpha (TGF α) takes its name from one of its alternative ligands, epidermal growth factor and is called the epidermal growth factor receptor. Although there is immunoreactive epidermal growth factor in the stomach, it is TGF α and the epidermal growth factor receptor that are abundant. Immunolabelling at electron microscope level allows for subcellular localisation of antigens; pS2 and human spasmolytic peptide co-localise to cytomembranes, including the Golgi apparatus, and thecae of surface/pit mucous cells. TGF α is abundant on the membranes of tubulovesicles of parietal cells and is also present in chief cells: in mucous producing cells it can be detected but not in association with mucous. The distribution of the epidermal growth factor receptor mimics that of TGF α but with preferential clustering on the basolateral membranes of gastric cells. The trefoil peptides are associated with healing and probably act, together with mucus, to protect the gastric mucosa and maintain a viable environment. TGF α, transduced via the epidermal growth factor receptor, inhibits gastric acid secretion, thus aids the trefoils in the maintenance of a gastric microenvironment conducive to healing after damage. TGF α, however, is also a potent mitogen; while this property plays a vital part in repairing mucosal defects, if this peptide or indeed its receptor are overexpressed, the result can be neoplasia. © 1995 Wiley-Liss, Inc.
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  • 81
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    Microscopy Research and Technique 32 (1995), S. 164-179 
    ISSN: 1059-910X
    Keywords: Parathyroid gland ; Hyperparathyroidism ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Parathyroid glands (n = 271) removed from 130 patients were examined by light and electron microscopy. A standardized method of tissue processing was employed and morphometry was performed. The aim of the paper is to provide a description of the human parathyroid chief cell ultrastructure in health and disease, with quantitative evaluation of structures involved in secretion of parathyroid hormone in a large case series, and to discuss their role in current diagnostic histopathology. The patients were euparathyroid (n = 10), or affected by primary (n = 97), secondary (n = 8), or tertiary (n = 15) hyperparathyroidism. In normal glands, solid parenchyma was composed of chief cells, large clear cells, transitional-oxyphil cells, and oxyphil cells. Chief cell hyperplasia, pseudo-adenomatous hyperplasia, adenoma, water-clear cell hyperplasia, and carcinoma were the most usual forms of parathyroid disease responsible for primary hyperparathyroidism. In chief cell hyperplasia, all the parathyroid glands were enlarged and the chief cells were in an active state of hormone secretion, with a large Golgi complex, abundant rough endoplasmic reticulum (RER), small lipid droplets, and tortuous plasma membrane. In pseudo-adenomatous hyperplasia, one gland was enlarged and the others displayed a normal size; however, electron microscopic examination and morphometric analysis showed that all the glands had active cells. Adenomas displayed a pattern similar to those of pseudo-adenomatous hyperplasia, with one gland enlarged and the others of normal size. However, ultrastructural examination and morphometry showed that the normal-size glands were hypo-active. Water-clear cell hyperplasia showed cells filled with cytoplasmic vacuoles. In these cells, structures with intermediate features between secretory granules and vacuoles were visible. Nucleo-cytoplasmic atypias were frequently visible in parathyroid carcinoma cells. In secondary and tertiary hyperplasia, active chief cells were regularly mixed with oxyphil or transitional-oxyphil cells. The tertiary hyperplasia was characterized by RER-associated structures that were not found in the normal or other pathologic conditions. These results demonstrate that electron microscopy and morphometry represent useful tools in parathyroid histopathology. © 1995 Wiley-Liss, Inc.
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  • 82
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    Microscopy Research and Technique 31 (1995), S. 452-466 
    ISSN: 1059-910X
    Keywords: Connexins ; Intercellular communication ; Crystallization ; Electron microscopy ; Image analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Cardiac gap junctions play an important functional role in the myocardium by electrically coupling adjacent cells, thereby providing a low resistance pathway for cell-to-cell propagation of the action potential. Two-dimensional crystallization of biochemically isolated rat ventricular gap junctions has been accomplished by an in situ method in which membrane suspensions are sequentially dialyzed against low concentrations of deoxycholate and dodecyl-β-D-maltoside. Lipids are partially extracted without solubilizing the protein, and the increased protein concentration facilitates two-dimensional crystallization in the native membrane environment. The two-dimensional crystals have a nominal resolution of 16 Å and display plane group symmetry p6 with a = b = 85 Å and γ = 120°. Projection density maps show that the connexons in cardiac gap junctions are formed by a hexameric cluste rof α1 connexin subunits. Protease cleavage of α1 connexin from 43 to 30 kDa releases ∼13kDa from the carboxy-tail, and the projection density maps are not significantly altered. Uranyl acetate stain penetrates the ion channel, whereas phospho-tungstic acid is preferentially deposited over the lipid regions. This differential staining can be used to selectively probe the central channel of the connexon and the interface between the connexon and the lipid. The hexameric design of α1 connexons appears to be a recurring quaternary motif for the multigene family of gap junction proteins. © 1995 Wiley-Liss, Inc.
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  • 83
    ISSN: 1059-910X
    Keywords: In vivo intracellular recording ; Electron microscopy ; Preembedding immunohistochemistry ; Frontal cortex ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Immunoperoxidase labeling of lucifer yellow provides a sensitive method for morphological characterization of neurons recorded intracellularly in vitro or in vivo. However, the reaction product is often so dense that it obscures ultrastructural details necessary for the analysis of synaptic contacts onto individually filled neurons. In the present study, we describe a silver intensification procedure using 1 nm gold labeling of lucifer yellow as an optimal means for immunocytochemically identifying single physiologically characterized neurons at the ultrastructural level. Single neurons in the frontal cortex of anesthetized rats were impaled in vivo and filled with lucifer yellow. The brians were then perfused with an acrolein fixative. Single vibratome sections through the recording site were reacted with a rabbit antibody directed against lucifer yellow followed by goat anti-rabbit 1 nm gold-labeled IgG and silver intensified. For comparison, additional sections were processed for immunoperoxidase detection of lucifer yellow. Labeled sections were processed for light microscopy or embedded in plastic for electron microscopy. The immunogold-silver label as well as peroxidase reaction product of lucifer yellow was readily detected in cell bodies, proximal and distal dendrites, and spines. However, in contrast to immunoperoxidase, the immunogold-silver reaction did not obscure subcellular orgnelles. Most importantly, the synaptic junctions formed by afferents to the filled neuron were more easily identifiable following the immunogold-silver procedure. This clear visualization of postsynaptic densities is essential for examining synaptic circuitry between afferents and physiologically characterized neurons. © 1995 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
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  • 84
    ISSN: 1059-910X
    Keywords: Adenovirus ; Autoradiography ; Biotinylated probe ; Cytochemistry ; Electron microscopy ; Immunocytochemistry ; In situ hybridization ; Replication ; Transcription ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A significant amount of new information on structure-function relationships in nuclei of adenovirus-infected cells has accumulated during the last decade as a result of the combined use of several new cytochemical techniques. Localization of viral DNA on ultrathin sections of infected cells has been investigated at the ultrastructural level by using specific DNA staining and immunocytochemistry with monoclonal anti-DNA antibodies. Both techniques, however, concomitantly visualize cellular and viral DNA. The specific stain for DNA reveals the configuration of the DNA molecules in the different nuclear substructures, whateer their synthetic activities. The immunodetection of DNA reveals that specific antibodies strongly bind to DNA of condensed host chromatin and to both encapsidated and nonencapsidated inactive viral genomes. However, the observation of an abnormally low level of labeling over the substructures in which synthetic activities of viral genomes are known to be intense demonstrates a serious limitation of this technique for the detection of active DNA. Postembedding in situ hybridization is the most useful method for identifying with certainty the structures containing defined nucleic acid sequences. By using a biotinylated viral DNA probe, in situ hybridization provides specific identification of structures containing either viral DNA or viral RNA molecules. In addition, with appropriate pretreatment of the sections, it is possible to reveal either all the viral DNA-that is, both double- and single-stranded DNA molecules (dsDNA, ssDNA)-or more specific species such as only ssDNA or only dsDNA molecules. The replicative and transcriptional activities of viral genomes are determined by high-resolution autoradiography. Autoradiography after a short pulse incorporation of appropriate radioactive precursors by infected cells reveals the sites of cellular and viral DNA replication or trancription. A short pulse followed by chase periods of different durations reveals the progressive migration of the cellular and viral synthesized products. The in situ distribution of the viral 72 kDa DNA-binding protein, a highly phosphorylated protein which protects the viral ssDNA, is revealed either by immunocytochemistry with specific antibodies or by the bismuth staining method which stains all highly phosphorylated proteins, including both cellular and viral proteins. The combined results of all these cytochemical procedures reveal the composition and functions of some of the structures induced by adenovirus infection. They demonstrate that viral genomes engaged in replication lead to the formation of replicative foci in which two compartments rapidly develop, one of which results from the aggregation of single strands of viral DNA and their accompanying 72 kDa protein. Conversely, ssDNA and 72 kDa protein are rare in the other compartment which is the main site of replication and transcription of viral genomes. The procedural aspects and the contributions of electron microscope cytochemistry to an understanding of the biology of Ad5 viruses can serve as a basic framework for the study of other biological systems. © 1995 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
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  • 85
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    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 32 (1995), S. 246-254 
    ISSN: 1059-910X
    Keywords: Electron microscopy ; Microwave fixation ; Microwave irradiation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The use of microwave irradiation for rapid chemical fixation of tissues in electron microscopy is a subject of current interest. The effect of water load size and location, sample placement in the oven cavity (hot or cold spots), and time on tissue preservation were examined. The use of a microwave container (4 dram vial) encased in 60 ml of ice in a 100 ml polyethylene beaker and a 0% power setting between two 100% power settings (time interval) provided reliable control of temperature during microwave irradiation. High brightness neon lights provided a quick and easy method to identify and map hot and cold spots within the oven cavity. Using microwave irradiation for rapid glutaraldehyde and osmium tetroxide fixation of tissues (Pacific yew needle and mouse kidney and liver) for electron microscopy yielded preservation equal or better than routine immersion fixation when a time interval, a cold spot (as the sample location), and an ice-encased vial were used during microwave fixation. These adaptations provided reliable control of fixation conditions in an 800 watt laboratory microwave oven. © 1995 Wiley-Liss, Inc.
    Additional Material: 18 Ill.
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  • 86
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    Virchows Archiv 367 (1975), S. 171-179 
    ISSN: 1432-2307
    Keywords: Kidney failure ; Pregnancy ; Electron microscopy ; Hemolytic-uremicsyndrome ; Basement membrane ; Endothelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinico-pathological data from a patient with irreversible post-partum renal failure (IPRF) are presented. The electron microscopy of the late changes are described for the first time and consists of: 1. Thickening of the basement membrane. 2. Interposition of mesangial cells and matrix between the thickened basement membrane and the endothelial cell encircling the periphery of the tuft. 3. Multiplication of basal lamina material between mesangial cells and endothelial cells. 4. Proliferation of endothelial cells. All of the above changes tend to obliterate the glomerular tufts and transform the vascular lumina into slit-like spaces. They explain morphologically why most patients with IPRF terminate in chronic renal failure, if they survive the early changes. The late occurring hypertension is regarded as a secondary stimulation of the renin-angiotension system caused by partial or complete occlusion of arteries and arterioles.
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  • 87
    ISSN: 1432-2307
    Keywords: Tumors of the skin ; Histogenesis ; Classification ; Labyrinth nuclei ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über den Feinbau folgender Hauttumoren berichtet: Dermatofibrom (7 Fälle), Histiozytom (4 Fälle), Dermatofibrosarcoma protuberans (1 Fall) und Fibroxanthom (1 Fall). Aufgrund ihrer unterschiedlichen ultrastrukturellen Merkmale ist eine zweifache Unterteilung dieser Hauttumoren möglich: In eine Tumorgruppe, umfassend das Dermatofibrom, Dermatofibrosarcoma protuberans und Fibroxanthom, bei der die Faserbildung im Vordergrund steht und für deren Histogenese Fibroblasten angenommen werden können. Diese Tumortypen unterscheiden sich vom Histiozytom, dessen Zellcharakter vor allem durch die stark ausgeprägte Phagozytose- und Speichertätigkeit (Fett und Hämosiderin) bestimmt wird und für welches eine histogenetische Ableitung von Histiozyten wahrscheinlich ist. Die Zellkerne des Dermatofibromes und des Histiozytomes weisen einen einfachen Oberflächenverlauf auf, die des Dermatofibrosarcoma protuberans und Fibroxanthomes haben hingegen sehr stark gegliederte Formationen („Labyrinthkerne”). Diese Kernsegmentierung ist für das Dermatofibrosarcoma protuberans ein morphologisches Korrelat seiner Semimalignität. Eine Klassifizierung der faserbildenden Tumoren als „fibröse Histiozytome” erscheint aufgrund der ultrastrukturellen Analyse nicht gerechtfertigt.
    Notes: Summary A report on the ultrastructure of the following skin tumors: dermatofibroma (7 cases), histiocytoma (4 cases), dermatof ibrosarcoma protuberans (1 case), and fibroxanthoma (1 case). Because of their different ultrastructural characteristics a division into two groups is possible: one group of tumors would include dermatofibroma, dermatofibrosarcoma protuberans, and fibroxanthoma, where the formation of fibers is extensive and fibroblasts are suggested for its histogenesis. These types of tumor differ from histiocytoma, the cellular character of which is determined by a very pronounced phagocytosis and storage of lipid and hemosiderin; a histogenesis from histiocytes is probable. The nuclei of dermatofibroma and histiocytoma show a simple surfacedevelopment, whereas the nuclei of dermatofibrosarcoma protuberans and fibroxanthoma show multisegmented nuclei (“labyrinth nuclei”). In the case of dermatofibrosarcoma protuberans this kind of nuclear segmentation seems to be a morphologic correlate of its semimalignancy. Based on ultrastructural analysis a classification of these fiber-producing tumors into “fibrous histiocytomas” is not justified.
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  • 88
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    Virchows Archiv 369 (1975), S. 19-27 
    ISSN: 1432-2307
    Keywords: Alpha-1-antitrypsin deficiency ; Liver ; Electron microscopy ; Endoplasmic reticulum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fourteen liver biopsies from twelve young patients with liver diseases associated with homozygous, PiZZ phenotype, alpha-1-antitrypsin deficiency in their sera were examined by electron microscopy. In all these biopsies characteristic homogeneous material was found in some hepatocytes and corresponded, when observed on adjacent semithin sections by light microscopy, to the deposit stained by periodic acid Schiff reaction. The accumulation in perinuclear spaces resulted in intranuclear invaginations, but the major deposit was located in lumens of the endoplasmic reticulum. The limiting membranes were rough and smooth but the extent of the latter was so large that only this type of reticulum seemed peculiarly involved in the accumulating process. On the contrary, Golgi complexes did not seen obligatorily involved by this process because, when observed, they appeared almost normal even in heavily overloaded liver cells. At least for the PiZZ phenotype, the abnormal substance would be an asialo form of normal alpha-1-antitrypsin. Thus the subject of this study is the morphologic translation of an impairment in the synthesis of a glycoprotein. In the light of data concerning the synthesis of such proteins our findings lead us to suggest: The ultrastructural patterns observed in alpha-1-antitrypsin deficiency cannot give the expected morphologic evidence of the biochemical data which locate the first binding steps of monosaccharide residues in the rough endoplasmic reticulum. The absence of sialic acid could not result from an enzymatic defect primarily located in Golgi complexes but could be secondary to an impairment in the binding of one monosaccharide residue which improves subsequent fixation of sialic acid, in the smooth endoplasmic reticulum. Finally it seems necessary to emphasize that the relationship between the abnormal substance and various important non specific lesions is largely unknown and that we don't know the significance of polymorphous dense bodies observed in ductular cells during the cholestatic period.
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  • 89
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    Virchows Archiv 369 (1975), S. 111-121 
    ISSN: 1432-2307
    Keywords: Atherosclerosis ; apoB ; LDL ; VLDL ; Immunoperoxidase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine-structural localization of apoB, the major protein constituent of both the low and very low density plasma lipoprotein fractions, was described in human middle cerebral and basilar arteries. Using an immunoperoxidase technique together with electron microscopy, apoB was localized only in arteries with atherosclerotic involvement and to the following regions in these arteries: 1. on the outer aspects of extracellular spherical structures with diameters of 250 to 700 Å found predominantly in lipid cores and between bands of collagen fibers of advanced atherosclerotic lesions; 2. on the surface of reduplicated elastica; 3. along collagen fibers and; 4. on aggregates of extracellular spherical lipid globules. These results suggest that the extracellular spheres may represent the fine-structural morphology of deposited low and very low density lipoproteius and that free apoB may be bound to lipid globules, elastica, and collagen fibers.
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  • 90
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    Virchows Archiv 368 (1975), S. 99-108 
    ISSN: 1432-2307
    Keywords: Electron microscopy ; Calcium ; Parathyroid glands ; Chief cells ; Oxyphil cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using the potassium pyroantimonate technique for ultrastructural localization of cations and X-ray elemental analysis with both energy dispersive and wave-length dispersive systems, calcium-containing precipitates were found in normal, hyperplastic and adenomatous human parathyroid glands. Differences were observed between oxyphil cells, and suppressed, stimulated and active chief cells in the content and localization of intracellular precipitation. The oxyphil cells and suppressed chief cells possessed precipitates mainly in nuclei and medium-sized and large mitochondria, whereas the stimulated chief cells possessed precipitates in normal-appearing and morphologically altered mitochondria, and in smooth-surfaced vacuoles and cytosol. The active chief cells usually showed a rather sparse precipitation.
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  • 91
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    Research in experimental medicine 165 (1975), S. 245-249 
    ISSN: 1433-8580
    Keywords: Vinblastine ; Liver ; Perisinusoidal cell ; Microtubules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Vinblastine, given intravenously to rats, leads to disappearance of microtubules, formation of paracrystalline inclusions and accumulation of fat droplets in the cytoplasm of the perisinusoidal cells of the liver suggesting that microtubules of the perisinusoidal cells play a role in lipid metabolism.
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  • 92
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    Anatomy and embryology 147 (1975), S. 293-307 
    ISSN: 1432-0568
    Keywords: Implantation ; Golden hamster ; Senescent ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Implantation was compared in young (3–5 month) and senescent (14–17 month) golden hamsters at 3, 31/2, 4, 41/2, 5, and 51/2 days of pregnancy (post-ovulation). One hundred twenty-two embryos (89 from 22 young females and 33 from 18 senescent females) located in utero by cutting thick sections (1–3 μm), were re-embedded and thin-sectioned for electron microscopy. Ultrastructurally implantation and embryonic differentiation was delayed approximately 12 hours in the senescent hamster when compared with young hamsters at the same stage of pregnancy. Failure of the blastocyst to implant would not appear to be a major cause of the declining litter size in aged golden hamsters.
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  • 93
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    Anatomy and embryology 146 (1975), S. 225-243 
    ISSN: 1432-0568
    Keywords: Differentiation ; Sympathetic ganglion ; Culture ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immature sympathetic ganglia prepared from 51/2- or 6-day-old chick embryos were cultured up to one month. The in vitro development was followed by phase microscopy, electron microscopy and using histochemistry for catecholamines, monoamine oxidase and cholinesterases. During the first week of culture extensive plexuses of nerve fibres were formed between and around the clusters of nerve cells. Mature-looking neurons were observed in the cultures by phase microscopy after three weeks, at which age the mean diameter of the perikarya was more than doubled. Varying catecholamine fluorescence was observed in the perikarya during the entire culture period. The nerve fibres showed usually only weak fluorescence, but, in the older cultures, bright varicosities were regularly found in the fibres. Monoamine oxidase activity was demonstrated already at three days of culture and the reaction was maintained positive. Weak or moderate acetyl-cholinesterase activity was demonstrated in the sympathicoblasts and young sympathetic neurons and their processes. The axolemma showed acetylcholinesterase activity also around the nerve terminals containing small dense cored vesicles. Reactions for the non-specific cholinesterases were negative. Electron microscopy of the 30-day-old cultures revealed that the clusters of nerve cells consisted of mature sympathetic neurons, which contained large (60–200 nm) and small (35–60 nm) granular catecholamine-storing vesicles. Glial cells were almost totally lacking. Large numbers of nerve terminals containing both large and small granular vesicles were observed in the clusters, often in synaptic contact with the sympathetic neurons. It is concluded that the primitive sympathicoblasts are, in favourable conditions, capable of differentiation in culture up to mature sympathetic neurons.
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  • 94
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    Anatomy and embryology 146 (1975), S. 279-300 
    ISSN: 1432-0568
    Keywords: Retinogenesis ; Synaptogenesis ; Guinea pig ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A light and electron microscopic examination of retinogenesis in the fetal guinea pig has revealed an early development of synapses and photoreceptor cells. Differentiation of the neural retina begins around day 23 of gestation. By 34 days the retina reaches its maximum thickness. It differentiates an inner plexiform layer in which vesicle-containing processes and primitive synapses are evident. Synaptic ribbons are found in processes of this layer by 43–45 days of gestation. An outer plexiform layer develops within the neuroblast layer at 40 days of gestation; from its first appearance the outer plexiform layer contains synapses complete with synaptic ribbons. Receptor terminals of the α, paranuclear and β type are present well before birth. Photoreceptor cells form inner segments by 40 days; the formation of outer segments is indicated by 45 days but not widespread until 49 days. The retina appears mature by day 51–57. It is clear that the primate is not unique in the early differentiation of its retinal synapses relative to the time of maturation of its photoreceptor cells. The potential functional capacities of precocious retinae, and the mechanisms of synapse development are discussed.
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  • 95
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    Anatomy and embryology 147 (1975), S. 177-187 
    ISSN: 1432-0568
    Keywords: Iris ; Melanogenesis ; Chicken embryo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The iris anlage of 2–10 and 15 days old chicken embryos were studied histochemically, and by both light and electron microscopy. Light microscopic serial sections showed that pigmentation began at the outer layer of the posterior eye pole and progressed from there forwards to the optic cup margin. The entire outer layer of the optic cup as well as the pupillary margin were completely pigmented by the 4th day of incubation. By the 10th day the posterior iris epithelium was totally pigmented. Electron microscopical studies showed that the first premelanosomes appeared at about the 3rd day of incubation in the anterior iris anlage with the exception of the pupillary margin. It could be shown that melanogenesis progressed through the following steps: premelanosomes, followed by tyrosinase activity in a Golgi-associated system of smooth endoplasmic reticulum (GERL) and small vesicles and finally differentiation of the melanosomes. The possible origin of the premelanosomes and the formation of melanin are discussed.
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  • 96
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    Applied physics 8 (1975), S. 319-331 
    ISSN: 1432-0630
    Keywords: Self-interstitials in silicon ; Swirls ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Point defect agglomerates in dislocation-free silicon crystals, usually called “swirls”, have been investigated by means of high-voltage electron microscopy. It was found that a single swirl defect consists of a dislocation loop or a cluster of dislocation loops. By contrast experiments it could be shown that these loops are formed by agglomeration of self-interstitial atoms. Generally the loops have a/2〈110〉 Burgers vectors, but in specimens with high concentrations of carbon (∼1017 cm−3) and oxygen (∼1016 cm−3) also dislocation loops including a stacking fault were observed. In crystals grown at growth rates higher thanv=4 mm/min no swirls are observed; lower growth rates do not markedly affect the size and shape of the dislocation loops. With decreasing impurity content (particulary of oxygen and carbon) the swirl density decreases, whereas the dislocation loop clusters become larger and more complex. A model is presented which describes the formation of swirls in terms of agglomeration of silicon self-interstitials and impurity atoms.
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  • 97
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    Acta neuropathologica 33 (1975), S. 245-256 
    ISSN: 1432-0533
    Keywords: Herpes simplex encephalitis ; Blood-vessels ; Reactive microglia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Generalized vascular changes and diffused proliferation of reactive microglia were observed in an experimental model of HSV encephalitis of mice. The wide spread of these changes contrasted with the localized character of virus replication and the confined areas of damaged nervous tissue. The vascular and microglial changes were precocious in animals inoculated with concentrated virus suspension (105.5LD50) while they appeared late in mice inoculated with diluted virus suspension (100 LD50). After inoculation with U.V. inactivated virus no changes were seen. The results obtained in this study suggest that the vascular and microglial modifications are not related to a direct cytopathic effect of the virus but dependent on the amount of virus present in the central nervous system and linked to the virus DNA.
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  • 98
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    Acta neuropathologica 33 (1975), S. 275-278 
    ISSN: 1432-0533
    Keywords: Whipple's disease ; Macrophage ; Electron microscopy ; Brain involvement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A man of 22 with Whipple's disease suffered from an acute febrile state and unconsciousness. Focal inflammatory lesions accompanied by large numbers of peculiar macrophages occurred in thalamus and basal ganglia. The electron microscopic findings conform to previous reports on brain involvement in Whipple's disease.
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  • 99
    ISSN: 1432-0533
    Keywords: Adult metachromatic leukodystrophy ; Brain ; Peripheral nerve ; Kidney ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural characteristics of storage products in peripheral nerve, kidney and cerebral white matter, from a case of adult metachromatic leukodystrophy are described. There were pronounced differences from the fine structural aspects in late infantile cases. A large proportion of the inclusions did not exhibit a unit membrane. An hypothesis is proposed to clarify the delayed manifestation of this type of metachromatic leukodystrophy until adulthood.
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  • 100
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    Acta neuropathologica 33 (1975), S. 191-200 
    ISSN: 1432-0533
    Keywords: Niemann-Pick disease ; Storage distribution ; Cerebral vascular glycolipid ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A histochemical study is reported of regional differences of the lipid storage in a case of Niemann-Pick disease (NPD) type C. Besides tissues known to be affected (reticuloendothelium, hepatocytes, nervous system), storage was demonstrated in adrenal cortical spongiocytes, sweat glands, renal glomerular and tubular cells, smooth muscle, excretory tubules of some salivary glands, ependyma and in choroid plexus. In most tissues were stored sphingomyelin, cholesterol and a small amount of a glycosphingolipid. In the endothelium of cerebral and spinal vessels the main stored lipid was a glycosphingolipid. The significance of these regional differences are discussed and their study is recommended as a useful counterpart to the biochemical investigation.
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