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  • 1
    Electronic Resource
    Electronic Resource
    Diffusion barrier properties of the perineurium: an in vivo ionic lanthanum tracer study (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 237-242 
    Details
    ISSN: 1432-0568
    Keywords: Perineurium ; Lanthanum ; Diffusion barriers ; In vivo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary While the perineurium as a diffusion barrier has been extensively investigated by light and electron microscopy, copy, such studies have been largely restricted to the use of protein tracers. In the present study the permeability of the perineurium to a physiologically more relevant ionic tracer has been assessed. In vivo the rat sural or tibial nerve was either microinjected with lanthanum nitrate solution for endoneurial application or bathed in the lanthanum solution for epineurial application. The findings generally demonstrated an effective barrier to the tracer which failed to penetrate the inner layers of the perineurium. Only at the highest lanthanum concentration and longest time intervals employed did trace quantities occasionally penetrate the barrier and then only in the presence of some cytopathological changes to the outermost perineurial cells. The usefulness of the microinjection method was limited by the slight but unavoidable trauma to the perineurium. The findings are related to those of other studies which have used electron dense tracers, also to studies using physiological including electrophysiological techniques and morphological including freeze-fracture methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315882
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  • 2
    Electronic Resource
    Electronic Resource
    Synaptogenesis in the dorsal lateral geniculate nucleus of the rat (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 243-257 
    Details
    ISSN: 1432-0568
    Keywords: Dorsal lateral geniculate nucleus ; Synapse formation ; Synaptic glomerulus ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Synapse formation and maturation were examined in the rat dorsal lateral geniculate nucleus (dLGN) from birth to adulthood. Examination of animals, whose ages were closely spaced in time, showed that the maturation of the synaptic organization of the nucleus takes place chiefly during the first 3 weeks of postnatal life. This period of maturation may be divided into 3 broad stages. During the first stage, which spans the first 4 days of life, there are only a few immature synapses scattered throughout the nucleus; occasionally aggregates of 3 or 4 synapses are encountered. Dendrodendritic synapses first appear at the end of this stage. The second stage, which lasts from the end of the first stage through day 8, is characterized by intensive synaptogenesis as well as extensive growth and degeneration. For the first time, large boutons resembling retinal terminals form multiple synaptic contacts with dendrites and dendritic protrusions; these synaptic arrangements are partially covered by glial processes. A feature characteristic of the developing dLGN during the first 2 postnatal weeks, and particularly during the second stage, is the presence of membrane specializations that resemble vacant postsynaptic densities. These specializations, which may be unapposed or opposite another neuronal process, decrease in frequency as the number of synapses increases. It is not known whether these densities are converted to synapses or whether they result from loss of presynaptic elements. The third stage in the process of synaptogenesis, which spans a period between days 10 and 20, is characterized by myelination and by the diminution of growth cones, degenerating profiles and vacant postsynaptic densities. There is also a very significant increase in the number and maturation of synapses including synaptic glomeruli. However, it is not until the end of this stage that synapses appear qualitatively indistinguishable from synaptic arrangements identified in adult animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315883
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  • 3
    Electronic Resource
    Electronic Resource
    Myelin breakdown in the posterior funiculus of the kitten after dorsal rhizotomy (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 273-280 
    Details
    ISSN: 1432-0568
    Keywords: Wallerian degeneration ; Myelin breakdown ; Light microscopy ; Electron microscopy ; Marchi staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphological aspects of myelin breakdown in the posterior funiculus during Wallerian degeneration were studied in kittens subjected to lumbosacral dorsal rhizotomies 6–8 days after birth. The first sign of myelin breakdown was characterized by swollen or shrunken nerve fibers. Shortly thereafter there was an increased occurrence of collapsed myelin sheaths and later of rounded myelin bodies. Myelin was clearly seen in microglial cells. Correlative observations on Marchi-stained material indicated the simultaneous and frequent appearance of Marchi-positive bodies (MPB:s) and myelin bodies. Due to the rapidity of the degeneration process in the kitten, the increase in the occurrence of Marchi-positive granules (MPG:s) seemed to start concomitantly with increased occurrence of MPB:s. However, the frequent occurrence of MPG:s outlasted that for MPB:s. The findings indicate that the MPB:s may be the counterpart to myelin bodies and the MPG:s to lipid droplets. Microglial cells may be responsible for the primary uptake of degenerating myelin and the subsequent transformation of myelin bodies to lipid droplets. The much faster breakdown of myelin and elimination of lipid material in the degenerating posteror funiculus of the kitten, as compared to the adult, seemed to be due not only to the lower myelin content in the kitten, but also to a higher density of microglia and a greater efficiency in the myelin breakdown process in the degenerating posterior funiculus of the kitten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315885
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  • 4
    Electronic Resource
    Electronic Resource
    Hypomyelination in the neonatal rat central and peripheral nervous systems following tellurium intoxication (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 301-309 
    Details
    ISSN: 1432-0533
    Keywords: Schwann cell ; Oligodendrocyte ; Electron microscopy ; Myelin ; Optic nerve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neonatal rats were exposed to Tellurium (Te), via the mother's milk, from the day of birth until sacrifice at 7, 14, 21, and 28 days of age. Light and electron microscopy revealed Schwann cell and myelin degeneration in the sciatic nerves at each age studied. These changes were similar to those described in weanling rats as a result of Te intoxication. In the CNS, hypomyelination of the optic nerves was convincingly demonstrated at 14, 21, and 28 days of age, accompanied by some evidence of myelin degeneration. These changes were also seen in the ventral columns of the cervical spinal cords, although less markedly, and were confirmed by quantitative methods. There was little evidence of oligodendrocyte pathology in the CNS, and it appears that degeneration of these cells is not the primary cause of the CNS hypomyelination, in contrast to the PNS where Schwann cell degeneration has been shown to precede the myelin pathology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687760
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  • 5
    Electronic Resource
    Electronic Resource
    Pick bodies in the locus ceruleus (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 10-17 
    Details
    ISSN: 1432-0533
    Keywords: Locus ceruleus ; Pick bodies ; Lewy bodies ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In classical Pick's disease with typical Pick bodies, inclusions resembling those present in the cerebral cortex are frequently found in the locus ceruleus. In three such cases Pick bodies were studied by light and electron microscopy and compared with Lewy bodies, inclusions more commonly found in this location. In contrast to the situation in the cerebral cortex, nerve cells with multiple Pick bodies were often found in the locus ceruleus, but in other respects definite light and electron microscopic differences between Pick bodies and Lewy bodies were present. Pick bodies were slightly basophilic and never had a central core or a peripheral halo. They were intensely argyrophilic. Differences in immunocytochemical reactions were especially marked with antibodies to tau and to paired helical filaments. Pick bodies displayed an intense reaction with these two antibodies, contrasting with that of Lewy bodies, which either lacked reactivity or reacted in a peripheral band. By electron microscopy the Pick bodies were composed of random filaments with smooth contour, whereas typical Lewy bodies had fuzzy deposits on filaments that radiated from a central core. Pick bodies in the locus ceruleus therefore maintained their immunocytochemical and electron microscopic characteristics and did not take on the character of Lewy bodies. Such differences point to a different pathogenesis and perhaps etiology of these two types of inclusions and attest to the marked difference clinically and pathologically between Pick's and Parkinson's diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308950
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  • 6
    Electronic Resource
    Electronic Resource
    Electron microscopic and Golgi study in a case of hemimegalencephaly (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 664-666 
    Details
    ISSN: 1432-0533
    Keywords: Hemimegalencephaly ; Golgi study ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pathological findings in a case of hemimegalencephaly are presented. Hemispherectomy, performed because of intractable seizures, allowed an electron microscopic and Golgi study. Glial abnormalities consisted of hyperplasia of glia cells with giant astrocytes often containing several nuclei and proliferation of numerous Rosenthal fibers. Golgi stain showed many giant neurons with a perikaryon covered by perisomatic processes, and a complex dendritic tree. Glial abnormalities could be correlated with the firmness of the hemisphere and intense hypersignal on magnetic resonance imaging. Giant neurons were associated with an increase in size of the perikaryon and dendritic tree; this pattern suggests a polyploidy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687896
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  • 7
    Electronic Resource
    Electronic Resource
    Melanotic paraganglioma of the orbit: a case report (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 340-346 
    Details
    ISSN: 1432-0533
    Keywords: Paraganglioma ; Melanin ; Orbit ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A paraganglioma of the orbit in a 21-year-old woman is presented, containing oculo-cutaneous melanin in many tumor cells, occasionally adjacent to neurosecretory granules, and in macrophages. This tumor expands the list of neuroectodermal tumors with potential melaninization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294673
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  • 8
    Electronic Resource
    Electronic Resource
    The astroblastoma and its possible cytogenic relationship to the tanycyte (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 472-483 
    Details
    ISSN: 1432-0533
    Keywords: Astroblastoma ; Electron microscopy ; Immunohistochemistry ; Organ culture ; Tanycytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two examples of cerebral astroblastoma have been studied by electron microscopy and immunohistochemistry, one of them having been maintained in vitro in an organ-culture matrix system for 8 months and the explants studied by light and electron microscopy at different time intervals. The fine structural characteristics were those of a glial cell type with features intermediary between those of astrocytes and ependymocytes. They recapitulated the structure of the tanycyte, a glial precursor cell which is normally found scattered along the ependymal lining of the embryonal and neonatal mammalian brain, but is distinct from epithelial ependymocytes. The possible origin of some astroblastomas from such a cell would account for a number of characteristics in this enigmatic type of glioma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687708
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  • 9
    Electronic Resource
    Electronic Resource
    Sporadic motor neuron disease with Lewy body-like hyaline inclusions (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 555-560 
    Details
    ISSN: 1432-0533
    Keywords: Sporadic motor neuron disease ; Lewy body-like hyaline inclusions ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lewy body-like hyaline inclusions were immunocytochemically and electron microscopically investigated in a patient with sporadic motor neuron disease. The hyaline inclusions were chiefly observed within the perikarya of both normal-looking and chromatolytic anterior horn cells in the lumbar spinal cord, but some were detected in the axons and dendrites. Usually, a single inclusion was found in the perikaryon, but in rare cases two or more were observed. Immunocytochemically, these inclusions were intensely immunostained with anti-ubiquitin anti-body. Ultrastructurally, the hyaline inclusions were chiefly composed of randomly arranged linear structures associated with ribosome-like granules, varying from compactly arranged linear densities to more loosely packed ones. They contained scattered vesicles of various sizes and occasionally a focal accumulation of randomly arranged 10-nm neurofilaments or 13–25-nm filamentous structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687719
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  • 10
    Electronic Resource
    Electronic Resource
    Morphological studies on cerebral cortical lesions induced by transient ischemia in Mongolian gerbil —Diffuse and peripheral pallor of the neuronal perikarya (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 1-8 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Ischemic neuronal injury ; Long-term recovery ; Mongolian gerbil ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unilateral transient cerebral ischemia was produced in Mongolian gerbils by clipping the left common carotid artery for 1h. About 60% of the gerbils with neurological symptoms had post-ischemic seizures. The majority of those that had seizures died within a few days, and sections of their cerebral cortices contained many dark and shrunken neurons. However, the gerbils that did not have seizures survived without any severe complications. In the cerebral cortex of the latter, the neurons with diffuse or peripheral pallor of the perikarya were seen along with a small number of dark and shrunken neurons. Diffuse pallor occurred within a few hours following ischemia in layers III, V and VI, and disappeared 1 or 2 days after recirculation. Electron microscopically, these neurons showed dispersion of ribosomes, simple and elongated profiles of rough endoplasmic reticulum (r-ER), clustered vacuoles, and mild to moderate mitochondrial swelling. Occasional net-like tubulomembranous structures, probably derived from r-ER, were observed. On the other hand, peripheral pallor became apparent after 5 days following ischemia, usually involving layer II first and gradually extending to the deeper layers. Concomitantly, the amount of neuropil decreased and the dendrites exhibited tortuosity and irregularity in layer II. Electron microscopically, these neurons showed marked swelling of peripheral perikarya and polyribosomes and organelles were located peripherally to the nuclei. In addition, numerous degenerated axon terminals and distended dendrites were observed around the neurons. These observations indicate that diffuse pallor represents damage directly induced by ischemia and subsequent recirculation, while peripheral pallor is the delayed and remote effect of ischemia, probably due to degeneration of neuronal processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687395
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  • 11
    Electronic Resource
    Electronic Resource
    Disseminated human neurocysticercosis (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 594-604 
    Details
    ISSN: 1432-0533
    Keywords: Neurocysticercosis ; Pathogenesis ; Histochemistry ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study was based on two cases of disseminated human neurocysticercosis from India. The material availabel was examined grossly, and by light microscopy, histochemistry, immunomorphology and electron microscopy. The results showed that the parasites commonly embolized to the anatomically discernable gray-white matter junction of the brain and were located in cavities, the walls of which were dilated vascular channels. The parasite-nutrition process was through endocytosis and microtrichal activity. To camouflage themselves from the host-defense mechanisms, the parasites apparently covered themselves with host-tissue-like material. Host reactivity to the parasite was heralded morphologically by the physical anchoring of the parasite by activated endothelial cells, loss of the host-tissue-like cover and an acute polymorphonuclear leucocytic response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691286
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  • 12
    Electronic Resource
    Electronic Resource
    Senile plaque-like structures: observation of a probably unknown type of senile plaque by periodic-acid methenamine silver (PAM) electron microscopy (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 137-142 
    Details
    ISSN: 1432-0533
    Keywords: Senile plaque-like structure ; Periodicacid methenamine silver (PAM) method ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerous diffuse senile plaque-like structures (SPLSs) were found in the cerebral cortex from cases with dementia of the Alzheimer type by means of the methenamine-Bodian method. SPLSs varied in shape and size. They were never recognized in the original Bodian, PAS and Congo red preparations, but were positive with anti-β-protein immunostaining and periodic-acid methenamine silver (PAM) methods, which are thought to specifically stain amyloid substance. With PAM electron microscopy, we found sparse aggregations of amorphous, often ramified, structures with fine granular silver deposits in SPLS. Routine electron microscopic examination on the same portion where SPLS were confirmed by PAM electron microscopy revealed amorphous, partially fibrous structures. These structures might be amyloid or amyloid-precursor substance. In SPLSs only a few degenerated neurites and astrocytic processes with glycogen granules were seen. We consider SPLSs to be a kind of senile plaque.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688201
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  • 13
    Electronic Resource
    Electronic Resource
    Localization of aggregation substances of Enterococcus faecalis after induction by sex pheromones (1989)
    Springer
    Archives of microbiology 151 (1989), S. 491-497 
    Details
    ISSN: 1432-072X
    Keywords: Aggregation substance ; Enterococcus faecalis ; Electron microscopy ; Field emission scanning electron microscopy ; Immunogold labelling technique ; Sex pheromone system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of sex pheromone induced aggregation substance was studied on the cell surface of various Enterococcus faecalis strains. In the accompanying paper we have shown that the aggregation substance appears as a layer of hairlike structures. Using direct and indirect immunogold technique, transmission electron microscopy and high resolution scanning electron microscopy we investigated the appearance and distribution of the aggregation substance. The “hairs” increase in number with increasing exposure to sex pheromones (maximum density: 1300/μm2). We show that these structures are unequally distributed over the cell surface, even if the cells were induced by sex pheromones for a long period of time. Statistical analysis of the unequal distribution indicates that aggregation substance is incorporated into pre-existing “old” cell-walls and that this incorporation shows a saturation ca. 40 min after addition of sex pheromones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454864
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  • 14
    Electronic Resource
    Electronic Resource
    Neural crest origin of clear cell sarcoma of tendons and aponeuroses (1989)
    Springer
    Virchows Archiv 415 (1989), S. 51-60 
    Details
    ISSN: 1432-2307
    Keywords: Clear cell sarcoma ; Melanosomes ; Cytochemistry ; Electron microscopy ; Nude mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718604
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  • 15
    Electronic Resource
    Electronic Resource
    An immunohistochemically defined non-Hodgkin's lymphoma showing intercellular junctions (1989)
    Springer
    Virchows Archiv 415 (1989), S. 297-300 
    Details
    ISSN: 1432-2307
    Keywords: Non-Hodgkin's lymphoma ; Electron microscopy ; Immunohistochemistry ; Intercellular junction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A rare example of pleomorphic B cell non-Hodgkin's lymphoma is described in which tumour cells possessed simple intercellular junctions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00724918
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  • 16
    Electronic Resource
    Electronic Resource
    Immunocytochemical and morphometric analysis of acinar zymogen granules in human acute pancreatitis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 115-124 
    Details
    ISSN: 1432-2307
    Keywords: Human acute pancreatitis ; Zymogen granules ; Acinar cells ; Electron microscopy ; Immunocytochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the present study fine structural changes of acinar zymogen granules were investigated in human acute pancreatitis. Pancreatic tissue was obtained at surgery from 6 patients, prepared for ultrastructural analysis, and stained immunocytochemically for trypsinogen. Stereological parameters of zymogen granules were evaluated. The density of the immunocytochemical labelling for trypsinogen was estimated over zymogen granules, the rough endoplasmic reticulum, Golgi apparatus and the acinar lumina. In acute pancreatitis the number of zymogen granules was diminished and their size reduced. The density of the labelling for trypsinogen was unchanged over zymogen granules but showed a significant reduction over the rough endoplasmic reticulum, Golgi apparatus, and the acinar lumina. In general the integrity of zymogen granules was well preserved. Focally degenerative changes of zymogen granules and large autophagosomes were observed. From the immunogold labelling a disturbance of enzyme synthesis and secretion was suggested. Evidence is given that a disruption of the zymogen granule membranes and a fusion with lysosomal bodies might contribute to the pathogenesis of human acute pancreatitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00784348
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  • 17
    Electronic Resource
    Electronic Resource
    Salivary gland myoepithelioma variants (1989)
    Springer
    Virchows Archiv 416 (1989), S. 25-42 
    Details
    ISSN: 1432-2307
    Keywords: Salivary gland ; Myoepithelioma ; Neoplasm ; Electron microscopy ; Immunohistochemistry ; Cytoplasmic filaments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histological and ultrastructural features of five major salivary gland tumours, which have little or no evidence of duct- or gland-type differentiation in routine sections, are described. Four of the cases have the tumour cells organized as narrow, anastomosing cords of cells separated by a myxoid and vascularized stroma; we have designated such lesions as reticular-type myoepitheliomas. The fifth case has a solid growth pattern and is largely composed of hyaline cells, that is, a plasmacytoid myoepithelioma. Ultrastructurally, one reticular myoepithelioma reveals myoepithelial cell differentiation with microfilament aggregates, while the other three examples are composed of modified myoepithelial cells displaying widened intercellular spaces, prominent synthesis of extracellular glycosaminoglycans, distinct basal lamina development, and obvious accumulations of cytoplasmic intermediate filaments. In electron micrographs, the modified myoepithelial cells of the plasmacytoid variant closely resemble the tumour cells in the reticular form. Three cases had expression of both glial fibrillary acid protein (GFAP) and vimentin, but only one of the myoepitheliomas contained muscle-specific actin. At least focally, each of the cases exhibited a considerable spectrum of cytokeratin filaments. Using double-labeled immunofluorescent microscopy of one reticular variant and the plasmacytoid myoepithelioma, there was individual tumour cell co-expression of GFAP and vimentin focally in the plasmacytoid myoepithelioma, but co-expression of cytokeratins 13, 16 and GFAP were not noted in either case. As expected, co-expression of high- and low-molecular weight cytokeratin filaments was wide-spread in both myoepitheliomas. Most described myoepitheliomas have a solid growth pattern and are composed of spindle and plasmacytoid cells, but based on cytological features and growth patterns in this series, it is apparent that polygonalshaped cells with novel architecture can occur in myoepitheliomas. The results also indicate the close relationship between pleomorphic adenoma and such variants of myoepithelioma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01606467
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  • 18
    Electronic Resource
    Electronic Resource
    Early bronchopulmonary lesions in rat lung after normobaric 100% oxygen exposure and their evolution (1989)
    Springer
    Virchows Archiv 414 (1989), S. 135-145 
    Details
    ISSN: 1432-2307
    Keywords: Hyperoxia ; Lung broncho-vascular reaction ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the early phenomena involved in the lung reaction to hyperoxia, twenty adult male rats were exposed to 100% oxygen at 1 ATA. Morphological pulmonary lesions were detectable after only 24 h hyperoxia, and included vasoconstriction and perivascular oedema, bronchiolar constriction, and pericyte reaction. The lesions were irregularly scattered within the lung parenchyma and occurred preferentially in areas centred on bronchiolo-vascular stems. Even at the latest stages, pulmonary heterogeneity was obvious, from the coexistence of areas damaged at different times. Neuro-epithelial-bodies were found under the bronchiolar epithelium; the morphological aspect of the neuro-endocrine cells observed was consistent with hyperoxia-induced modulation of their secretory activity. Taken together, our findings show the speed of development of hyperoxia-induced pulmonary changes and raise some pathogenic considerations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718593
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  • 19
    Electronic Resource
    Electronic Resource
    Liver parenchymal cell parasitism in human visceral leishmaniasis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 1-6 
    Details
    ISSN: 1432-2307
    Keywords: Visceral leishmaniasis ; L. donovani ; Parasitism ; Liver pathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Liver parenchymal cell parasitism with the amastigotes form ofL. donovani was detected by electron microscopy in human visceral leishmaniasis. Endocytosis was considered to be the mechanism by which the leishmania entered the cell. Evidence of well preserved parasites within hepatocytes suggest this parasitism as a possible reservoir for recrudescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718599
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  • 20
    Electronic Resource
    Electronic Resource
    Collagen secretion granules in reactive stromal myofibroblasts, with preliminary observations on their occurrence in spindle cell tumours (1989)
    Springer
    Virchows Archiv 415 (1989), S. 437-445 
    Details
    ISSN: 1432-2307
    Keywords: Collagen secretion granule ; Myofibroblast ; Spindle cell tumour ; Electron microscopy ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Collagen secretion granules, representing stages in the intracellular packaging, transport and secretion of collagen-fibril precursor, have been studied by transmission electron microscopy in non-neoplastic human myofibroblasts and in neoplastic cells from a preliminary study of tumours exclusively or partly of spindle cell type. Vesicles, newly separated from Golgi saccules and containing finely fibrillar material, were identified as early presecretory granules, the most immature type of granule. Later stages exhibited longitudinally arranged, densely fibrillar bundles. Subsequently, secretory granules developed more homogeneously dense content. Fibril-containing cisternae near the plasma membrane were interpreted as either endocytotic or lysosomal structures, or as participants in the final stages of secretion. The features by which collagen secretion granules can be distinguished from other Golgi products, in particular melanosomes, Weibel-Palade bodies and lysosomes, are pointed out. The significance of these organelles for cell identification and tumour diagnosis is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747745
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  • 21
    Electronic Resource
    Electronic Resource
    Biologic roles of the innermost cell layer of the outer root sheath in human anagen hair follicle: further electron microscopic study (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 254-259 
    Details
    ISSN: 1432-069X
    Keywords: Innermost cell layer ; Tonofilaments ; Huxley's cells ; Henle's cells ; Anagen hair follicles ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the biologic roles and further cytologic characteristics of the innermost cell (IMC) layer of the outer root sheath (ORS), human anagen hair follicles were ultrastructurally examined. In the lower follicle, the transeversely running tonofilaments in the inner side of the cytoplasm of the IMCs showed a massive accumulation, facing the keratinized part of a Huxley's cell protruding through a Henle's pore. In a rare instance, a spindle-shaped cell was seen between the IMC layer and the keratinized Henle's layer. At the lower isthmus portion, some of the IMCs containing a large number of tonofilaments showed a partial degeneration of the inner side of the cytoplasm. More distally, intercellular spaces between the keratinized IMCs and keratinized Henle's cells were partly dilated and contained amorphous substances. It is suggested that the IMCs in the lower follicle may play a role to support and cover the inner hair structures, tightly as hoops of a barrel. In the isthmus portion, the IMCs may loosely support and guide the keratinized Henle's cells undergoing degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431059
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  • 22
    Electronic Resource
    Electronic Resource
    Netherton's syndrome: ultrastructure of the active lesion under retinoid therapy (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 165-172 
    Details
    ISSN: 1432-069X
    Keywords: Netherton's syndrome ; Retinoid therapy ; Etretin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A young female patient, expressing the symptom triad of Netherton's syndrome, i.e., ichthyosis linearis circumflexa Comèl, trichorrhexis invaginata and other hair shaft defects, and atopic diathesis, has been treated successfully with the new retinoid preparation Etretin. Our electron microscopical study especially focused on the ultrastructural effect on the characteristic, active part of the skin lesions, which is only found within a narrow borderline just preceding the lesion's margin. In untreated skin, this part is characterized by dermal inflammation, immigrating inflammatory cells, and specific keratinization disturbances: synthesis of keratinization proteins is suppressed, serum exudates invade the epidermis, either filling the intercellular spaces of the upper spinous and the granular layer as finely granular, amorphous material, or they are partly phagocytosed and lie within intracellular, round-oval inclusions. The portions of the lesions lying towards the center are unspecific and represent recovery stages, ultrastructurally resembling stages of normal wound repair. Oral therapy with Etretin did not heal the basic defect, but drastically reduced exoserosis and the deposition of intra- and extracellular material. Keratinization seemed to normalize. The condition of the hair was also improved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456387
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  • 23
    Electronic Resource
    Electronic Resource
    Mitochondrial encephalomyopathy with pilovacuolar inclusion or phenocopy with mitochondrial artefact? (1989)
    Springer
    Journal of neurology 236 (1989), S. 361-363 
    Details
    ISSN: 1432-1459
    Keywords: Mitochondrial encephalomyopathy ; MELAS ; Mitochondrial inclusion ; Pilovacuolar inclusion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The case of a 33-year-old man with clinical features of mitochondrial encephalomyopathy is presented. He suffered from recurrent cerebral infarctions, cerebellar ataxia, deafness, retinopathy, weakness, and cardiac and renal disorders. Biochemical and light microscope investigations of skeletal muscle did not show any mitochondrial abnormality. Electron microscopy revealed the presence of a hitherto unreported peculiar “pilovacuolar” inclusion in numerous mitochondria, composed of an electron dense pile or rod within a vacuole, while globular or crystalline inclusions were absent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314383
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  • 24
    Electronic Resource
    Electronic Resource
    Human fetal endometrium -light and electron microscopic study (1989)
    Springer
    Archives of gynecology and obstetrics 246 (1989), S. 169-179 
    Details
    ISSN: 1432-0711
    Keywords: Human fetal endometrium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human fetal endometrium was examined by light and electron microscopy. Our study shows the following new morphological aspects: (1) Glands are already present. (2) Endometrium undergoes a maturation process during gestation and at late gestational age resembles late proliferative endometrium. (3) The nuclear bodies are present in cell nuclei throughout gestation. (4) Nucleolar channel systems (NCS) sometimes appear at a late gestational age. (5) Cells with the same morphology as that of endocrine cells are found in the basal layers of endometrium at a late gestational age. The significance of these morphological aspects is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00934078
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  • 25
    Electronic Resource
    Electronic Resource
    Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF (1989)
    Springer
    Experimental brain research 76 (1989), S. 38-46 
    Details
    ISSN: 1432-1106
    Keywords: Nerve growth factor ; C6 glioma cells ; Chromaffin cells histofluorescence ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to maintain a chronic supply of growth factor for medulla cells in vitro, chromaffin cells from rat, African green monkeys and man were co-cultured with C6 glioma cells, which secrete growth factors that sustain sympathetic neurons in vitro. The response of chromaffin cells to coculture was compared to treatment of medullary cells with nerve growth factor (NGF) alone. Dispersed chromaffin cell preparations were obtained by a trypsin-collagenase procedure, and subjected to differential plating on collagen-coated surfaces. With both human and monkey tissue, non-chromaffin cells did attach to the culture plates and an enriched chromaffin cell population could be replated. Rat adrenal medulla cells survived very poorly in vitro and were not enriched in this procedure. Cultured human and monkey chromaffin cells survived as epithelial cells (50%) and showed neuritic outgrowth on 55 to 66% of the cells after eight days when treated with nerve growth factor (NGF). These cells showed strong catecholamine histofluorescence, tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DBH) immunoreactivity. In contrast, only ten percent of adult rat chromaffin cells survived in culture, although NGF treatment rescued an additional 20% of the cells and induced neuritic outgrowth after one week in vitro. C6 glioma cells were treated with mitomycin C bromodeoxyuridine to inhibit mitosis and were plated with the various medulla cells in a one to one ratio. Both human and monkey chromaffin cells expressed extensive and enhanced neuritic arborization within eight days of co-culture, (64–82% respectively) and exhibited intimate contact with the glioma cells as seen at the ultrastructural level. Importantly, survival of adult rat adrenal medulla cells was enhanced to 50% or more with 40% of the cells extending neurites when co-cultured with glioma cells for seven days. Chromaffin cells from all three species reacted for TH, DBH and PNMT in co-culture and were histofluorescent. The majority of these cells were also immunoreactive for serotonin and enkephalin, while only 37% of chromaffin cells indicated the presence of NPY. These data indicate that adrenal medulla can be maintained in vitro as the neuronal phenotype when co-cultured with growth factor producing cells and that this strategy may be useful for in vivo transplantation studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00253621
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  • 26
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the hypertrophied human papillary muscle cell with special emphasis on specific staining patterns, mitochondrial projections and association between mitochondria and SR (1989)
    Springer
    Virchows Archiv 414 (1989), S. 187-198 
    Details
    ISSN: 1432-2307
    Keywords: Human heart ; Papillary muscle ; Hypertrophy ; Mitochondria ; Specific staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Biopsy material of the hypertrophied human papillary muscle has been processed according to various electron microscopical techniques in order to study the mitochondrial ultrastructure and the association between mitochondria and sarcoplasmic reticulum (SR).En bloc staining with a Cu-Pb citrate solution resulted in specifically contrasted mitochondrial and sarcotubular membranes, characterized by numerous, discrete, electron-dense particles. The differences in staining patterns between the perinuclear mitochondria and their subsarcolemmal and interfibrillar counterparts suggest differences in chemical properties and/or metabolic activities. The selectively contrasted mitochondrial particles may represent a conglomorate of extrinisic and intrinisic respiratory enzymes and other membrane-associated proteins, while the majority of the electron-dense particles of the sarcotubular membrane may represent positively stained Ca2+-pumps. Ultrastructural findings in the present study strongly indicate that the slender mitochondrial projections represent an initial stage in a process leading to the formation of large and pleomorphic mitochondria. Intimate contact between adjacent mitochondria as well as between mitochondria and SR are documented. In the contact regions some of the specifically contrasted particles of the adjacent membranes had fused with each other. It is suggested that these particles represent membrane-bound transport proteins providing a system for interorganelle exchanges of metabolites and/or ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00822022
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  • 27
    Electronic Resource
    Electronic Resource
    Ultrastructural and electron immunohistochemical features of medullary thyroid carcinoma (1989)
    Springer
    Virchows Archiv 414 (1989), S. 375-384 
    Details
    ISSN: 1432-2307
    Keywords: Thyroid neoplasms ; Electron microscopy ; Immunohistochemistry ; Calcitonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study, both morphological and immunohistochemical, has been carried out on eight thyroglobulin-positive and nine thyroglobulin-negative medullary carcinomas of the thyroid. The morphometric analysis of granule size showed that all tumours contained cells with small granules and cells with medium size granules, whereas eight tumours had additional cells with large granules. The small granules had an electron dense core, while the medium and large sized granules were both pale-cored and dense-cored. The cells with small, medium or large secretory granules were all immunoreactive for calcitonin and CGRP. No ultrastructural differences were observed between thyroglobulin-positive and thyroglobulin-negative cases of medullary carcinoma of the thyroid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718620
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  • 28
    Electronic Resource
    Electronic Resource
    Carcinosarcoma of the urinary bladder (1989)
    Springer
    Virchows Archiv 415 (1989), S. 91-95 
    Details
    ISSN: 1432-2307
    Keywords: Carcinosarcoma ; Urinary bladder ; Immunohistochemistry ; Electron microscopy ; Rhabdomyoblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of urinary bladder carcinosarcoma (UBCS) is reported with light, immunohistochemical and electron microscopical findings. The tumour consisted of a squamous cell carcinoma, variable spindle cell stromal elements compatible with fibrosarcoma, and rhabdomyoblasts. Intermediate filament co-expression of cytokeratin and vimentin was shown by immunohistochemistry. Electron microscopy (EM) confirmed the nature of the three components, and indicated some similarities between the three cell-types present. Comparisons with the previous UBCS in the literature are made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718608
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  • 29
    Electronic Resource
    Electronic Resource
    A histopathological study on the prognosis of childhood IgA nephropathy and glomerular basement membrane lesions (1989)
    Springer
    Pediatric nephrology 3 (1989), S. 242-247 
    Details
    ISSN: 1432-198X
    Keywords: IgA nephropathy ; Electron microscopy ; Glomerular basement membrane lesions ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Seventy-three patients with IgA nephropathy (IgAGN), under the age of 15 years at the time of the discovery of the disease, were investigated with respect to glomerular basement membrane (GBM) lesions. Irregular attenuation or widening of GBM, especially on the epithelial side, was observed in 28 cases (38%). These two changes are referred to aslysis of GBM and were considered to be the primary and specific changes among the GBM lesions in IgAGN. GBM thickening with layering of lamina densa was found in 37 of 73 cases (51%), but this change has been observed in other types of glomerular diseases. GBM lesions similar to those seen in IgAGN were also observed in Henoch-Schönlein purpura nephritis (HSPN) and poststreptococcal acute glomerulonephritis (PSAGN). Lysis of GBM was observed only in IgAGN, HSPN and PSAGN. Subepithelial and intramembranous deposits appeared to have an important role in the development of these GBM lesions. The presence of GBM lesions was correlated with a high incidence of cellular crescents but not with other clinical or light microscopic findings. The presence of these GBM lesions in IgAGN does not have a significant effect on the prognosis, at least in childhood. The affected GBM seemed to recover without leaving any significant residual damage in most cases. In the long-term prognosis of the disease non-immunological factors, such as ageing or hypertension, seem to be important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00858523
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  • 30
    Electronic Resource
    Electronic Resource
    Retinal axons innervate the embryonic chick diencephalon in an in-vivo-like pattern in expiant co-cultures (1989)
    Springer
    Experimental brain research 75 (1989), S. 563-568 
    Details
    ISSN: 1432-1106
    Keywords: Retina ; Diencephalon ; Co-culture ; Synapses ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Explants of chick embryo diencephalon co-cultured with explants of retina display areas of complex neuropil containing large retinal-like endings which establish synaptic contact with conventional and presynaptic dendrites. Transection of fibre bundles linking retinal to diencephalic explants results in the degeneration of endings of this type, suggesting that axons of extrinsic (retinal) origin innervate the diencephalic explants in an in-vivo-like manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00249907
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  • 31
    Electronic Resource
    Electronic Resource
    A quantitative analysis of the synaptic development of the lobus parolfactorius of the chick (Gallus domesticus) (1989)
    Springer
    Experimental brain research 78 (1989), S. 425-434 
    Details
    ISSN: 1432-1106
    Keywords: Avian forebrain ; Synapses ; Stereology ; Disector ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lobus parolfactorius (LPO) of the chick has been shown to undergo an increase in the mean synaptic numerical density (Nv syn) in response to one-trial passive avoidance learning (Stewart et al. 1987). The present study was undertaken in order to describe the pattern of normal development of synapses in the LPO, to further investigate the significance of this plastic response. The LPO's from each hemisphere of pre-hatch (16 days), and post-hatch (1 day, 9 day and 22 day old) chicks were processed for electron microscopy. Synapses were classified into asymmetric spine, asymmetric shaft, symmetric spine, and symmetric shaft synapses, on the basis of the density of the post-synaptic thickening and the nature of the post-synaptic target. A 3-dimensional stereological probe was used (the ‘disector’) to calculate Nv syp, and mean projected height (H syp) of the post-synaptic density (PSD). Mean values for each age and hemisphere were compared with a 2-way analysis of variance test using paired samples. A six-fold increase in Nv syp was seen between 16 days in ovo, and 9 days post-hatch. There was a hemispheric asymmetry at 9 days post-hatch, with the left hemisphere LPO containing 1.6 times as many synapses per μm-3. There was a subsequent period of reduction in synaptic density in the left hemisphere LPO between 9 and 22 days post-hatch. The Nv of all classes of synapse increased with age, but the proportions of the symmetrical synapses with respect to the total number of synapses, decreased with age. This decrease was of a similar magnitude for each hemisphere. A hemispheric difference was seen in post-hatch asymmetric synapses, with a greater proportion of asymmetric spine synapses in the left hemisphere. The magnitude of the hemispheric asymmetry was constant throughout the 3 week period of post-hatch development, but was not present in pre-hatch chicks. The PSD increased in length in each hemisphere by approximately 40% between post-hatch day 1 and post-hatch day 9. These data show that the LPO contains a synaptic population which undergoes substantial modification during the first week post-hatch. An asymmetry exists at post-hatch day 9 which is not present at the earlier ages investigated, nor indeed after 22 days post-hatch. This may have significance with regard to studies of passive avoidance learning in the one-day old chick, where an increase in both the size and number of synapses in the LPO has been demonstrated (Stewart et al. 1987). It is possible that ‘training’, in this situation, may simply enhance the timing of synaptic events that result as a consequence of normal development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228916
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  • 32
    Electronic Resource
    Electronic Resource
    An experimental study of mucociliary pathology of the eustachian tube in otitis media with effusion induced by irradiation (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 428-432 
    Details
    ISSN: 1434-4726
    Keywords: Otitis media with effusion ; Mucociliary system ; Eustachian tube ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have examined the function and fine structure of the mucociliary system of the eustachian tube in an experimental study of otitis media with effusion induced by X-ray irradiation. Functional examination demonstrated that the ciliary activity was diminished in such a condition, while morphological observations showed pathological findings including compound cilia, vacuolation of ciliated cells and expansion of intercellular space. These findings show that irradiation-induced otitis media with effusion results in impairment of the mucociliary system. As evidenced by these studies, the mucociliary system in the eustachian tube has an important role in the clearance of fluid produced in the tympanic cavity as well as affording improvement in this disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464303
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  • 33
    Electronic Resource
    Electronic Resource
    Synovial lining cells (1989)
    Springer
    Rheumatology international 9 (1989), S. 49-51 
    Details
    ISSN: 1437-160X
    Keywords: Synovium ; Monoclonal antibodies ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cells making up the lining of the synovium have long been known as type A and B synoviocytes, with an intermediate form sometimes also described. Accumulating evidence shows that the type A cells are macrophages and the type B cells are fibroblasts. Recently, a definite orientation of these cells within the synovial lining has been observed. The number of synovial lining cells increases in joint disease, and this now seems more likely to be due to cellular recruitment rather than local proliferation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00270244
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  • 34
    Electronic Resource
    Electronic Resource
    Revascularization of isolated autologous bone grafts following microsurgical implantation of arteries and veins (1989)
    Springer
    European journal of plastic surgery 12 (1989), S. 29-34 
    Details
    ISSN: 1435-0130
    Keywords: Revascularization ; Vessel implantation ; Bone grafts ; Corrosion casts ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The microsurgical implantation of a saphenous vascular axis into free transplanted autologous isolated rib segments in Beagle dogs led to complete revascularization of the bone after two, three and four weeks. Indian ink and Mercox-injected specimens showed a vascular network which penetrated the entire cortical layer. Semi-thin sections revealed osteoblasts and osteoclasts visible in the canals of the revascularized cortical layer, while the control specimen without vessel implantation showed nothing but ground substance. The revascularized bones did not contain any necrotic areas. The newly formed vascular system consisted of arteries, veins and their anastomoses. The veins appeared to produce a greater number of new vessels than the arteries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226918
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  • 35
    Electronic Resource
    Electronic Resource
    Mallomonas alphaphora (Chrysophyceae), a new species from Western Australia (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 209-214 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chrysophyceae (Synurophyceae) ; Mallomonadaceae ; Mallomonas alphaphora ; Electron microscopy ; phytoplankton ; scale-bearing flagellate ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new species ofMallomonas, M. alphaphora (Chrysophyceae), was found in freshwater ponds in the Perth region, Western Australia. It is distinguished from other species ofMallomonas by its very distinctive scale and bristle morphology and is placed in a new section,Alphaphorae, of the genusMallomonas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940438
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  • 36
    Electronic Resource
    Electronic Resource
    Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports (1989)
    Springer
    Cell & tissue research 256 (1989), S. 573-580 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Epithelium ; Monolayer culture ; Histochemistry ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary N-acetylglucosaminidase (NAG), acid phosphatase (ACP) and alkaline phosphatase (AKP) were localised histochemically in fixed cells from the 37-day-old rat epididymis grown in static monolayer culture for 2–8 days. ACP and NAG were cytosolic enzymes found in perinuclear positions, whereas staining of AKP was consistent with a membranous position. These enzymes were also examined in frozen tissue sections of the epididymis, from rats of the equivalent age, where NAG had intense activity in both supra- and infra-nuclear cytoplasm and ACP was more active apically. For the first time AKP was localised along basolateral membranes of the epithelium and in the lumen of the mid-caput region. The monolayer in culture was of principal cells only and they maintained their polarity and ultrastructural characteristics, but the height of the cells was reduced compared to that obtained in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225606
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  • 37
    Electronic Resource
    Electronic Resource
    Two types of mammosomatotropes in mouse adenohypophysis (1989)
    Springer
    Cell & tissue research 256 (1989), S. 645-648 
    Details
    ISSN: 1432-0878
    Keywords: Mammosomatotropes ; Adenohypophysis ; Electron microscopy ; Immunohistochemistry ; Mouse (SMA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of mammosomatotropes (MS), the small-granule and vesicle-granule MS, were detected in mouse adenohypophysis by electron microscopy and immunohistochemistry. Both cell-types were immunoreactive to prolactin (PRL) and growth hormone (GH) antisera. The small-granule MS contained small, round, solid secretory granules about 100 nm in diameter, and were smaller than the classical GH and PRL cell-types. The vesicle-granule MS contained secretory granules like cored vesicles, and were larger than classical GH and PRL cells. Small-granule MS were immunoreactive to both PRL and GH antisera in the same region of the cell cytoplasm; the vesicle-granule MS, however, were immunoreactive to only PRL antiserum in most cytoplasmic areas, and a positive response to both PRL and GH antisera was confined to only certain small areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225615
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  • 38
    Electronic Resource
    Electronic Resource
    Localization of cholesterol in the colonic epithelium of the guinea pig: regional differences and functional implications (1989)
    Springer
    Cell & tissue research 258 (1989), S. 339-347 
    Details
    ISSN: 1432-0878
    Keywords: Proximal colon ; Distal colon ; Cholesterol ; Filipin ; Freeze-fracture ; Electron microscopy ; Guinea Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It is generally accepted that variations in membrane cholesterol content affect the fluidity of the bilayer, thus altering its permeability. In the biological membranes, in physiological conditions, a high cholesterol content rigidifies the bilayer decreasing its permeability, a lower cholesterol content induces the opposite effect by increasing the permeability. Since differences in the epithelial permeability for short chain fatty acids have previously been demonstrated in the proximal and distal colon of the guinea pig, these two regions were investigated to establish whether differences in membrane cholesterol content of the absorbing cells can be demonstrated. Freeze-fracture replicas of filipin-treated colonic tissue were used. The results show that in the proximal colon the density of filipin cholesterol complexes located on the luminal plasma membrane of the columnar absorbing cells was significantly higher (about twice) than in the distal colon. Therefore the lower amount of cholesterol present in the membrane of the absorbing cells in the distal colon indicates a greater fluidity of the membranes of the epithelial cells in this region. Such fluidity could be correlated to the higher absorption rates of shortchain fatty acids characteristic of this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239454
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  • 39
    Electronic Resource
    Electronic Resource
    Quantitative electron microscopy of endocrine cells in oxyntic mucosa of normal human stomach (1989)
    Springer
    Cell & tissue research 255 (1989), S. 41-48 
    Details
    ISSN: 1432-0878
    Keywords: Stomach ; Endocrine cells ; Electron microscopy ; Morphometry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural morphometric study of the endocrine cells of the oxyntic mucosa of the stomach in gastric biopsies collected from five male and five female healthy volunteers aged 19–31 was performed. No sex-related differences were disclosed. Endocrine cells accounted for 1.2±0.4% of the epithelial volume and 0.9±0.4% of the mucosal volume, i.e., including the lamina propria. After classification of the specific endocrine cell types according to the ultrastructural morphology of secretory granules, the volume densities of ECL, P and D cells (30±9%, 24±7%, and 22±4% of the entire endocrine cell mass, respectively) were higher than those of other endocrine cell types. In particular, EC cells contributed less than 10% and X cells represented a very low proportion of the total cells. Non-granulated profiles of cells which in all other respects appeared to be endocrine were also found with a volume density of 8±4%. D cells were distinguished by the high fraction of cytoplasm occupied by secretory granules (31±5%). Subdivision of the whole mucosa into four horizontal segments revealed the endocrine cells to be mostly distributed in the three lower, with virtually no endocrine cells in the superficial segment. The quantitative ultrastructural analysis of the endocrine cell population of the normal human oxyntic mucosa provided by this study may allow a better evaluation of physiological and pharmacological variations of the endocrine cell population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229064
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  • 40
    Electronic Resource
    Electronic Resource
    Gestational changes in hamster adrenal cortex: Morphometric and ultrastructural stereologic studies (1989)
    Springer
    Cell & tissue research 256 (1989), S. 241-246 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Pregnancy ; Electron microscopy ; Stereology ; Golden hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the hamster, the weight of the adrenal glands increases during the course of gestation, with the highest value at day 5. In comparison to non-pregnant control animals, there were no changes in the volume of the zona glomerulosa (ZG) and zona fasciculata (ZF), while the volume of the zona reticularis (ZR) increased notably. The average volume of ZG-cells rose at day 5 of pregnancy and thereafter gradually decreased to that of control hamsters. A marked drop in the volume of ZF-cells was seen at days 5 and 10 of pregnancy, whereas at day 15 the cells were larger than in controls. At day 5 of pregnancy, a conspicuous increase in the cell volume was found in ZR, followed by lower values at day 10 and again higher than in control hamsters at day 15. The total number of parenchymal cells in hamster adrenal cortex increased at day 10 of gestation, then underwent a marked decrease, reaching the control value at the final day of pregnancy; this drop was mainly due to a reduction in the number of ZF-cells. The changes in the cell volume were paralleled by rather proportional changes in the volume of the mitochondrial compartment and in the quantity of smooth endoplasmic reticulum. The volume of the lipid-droplet compartment significantly rose in the course of gestation in both ZF- and ZR-cells. The cortisol output by adrenal homogenates gradually decreased during pregnancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218881
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  • 41
    Electronic Resource
    Electronic Resource
    Glomerular podocytes in cultured rat kidney slices (1989)
    Springer
    Cell & tissue research 256 (1989), S. 419-429 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Glomerulus ; Podocytes ; Tissue culture ; Electron microscopy ; Morphometry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of rat glomerular epithelial cells (podocytes) in kidney slices in vitro was examined using qualitative and quantitative electron microscopy. The kidney slices were cultured in Medium 199 with Hanks' salts in a 5% CO2/95% O2 environment for up to 14 days. Few changes in podocyte ultrastructure occurred in the first 12 h of culture, but by 24 h cell bodies were rounded, microvilli were present on all podocyte surfaces, and some foot processes had been replaced by flattened expanses of cytoplasm. These changes were more pronounced by 3 days, when some podocytes had developed pseudopodal extensions and appeared to be migrating from glomeruli onto the slice surface. Podocytes could still be identified after 8, 10 and 14 days of culture, although relatively few glomeruli remained at 14 days. Morphometric methods were used to analyse podocyte shape, volume and surface area during the first 4 days of culture. The most significant change involved loss of foot processes: the number of filtration slits per 100 μm of basement membrane decreased from 211.8 ± 15.0 (mean ± SD) at the commencement of culture, to 55.3 ± 22.6 after 2 days (P 〈 0.001). These data provide baseline information for in vitro studies on the effects of nephrotoxins on podocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218900
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  • 42
    Electronic Resource
    Electronic Resource
    Nasal lymphoid tissue in the rat (1989)
    Springer
    Cell & tissue research 255 (1989), S. 193-198 
    Details
    ISSN: 1432-0878
    Keywords: Mucosa-associated lymphoid tissue ; Nose ; Lymphoepithelium ; Electron microscopy ; Immunohisto-chemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure and organization of paired lymphoid tissue in the nasal mucosa, situated in the transitional zone on both sides of the septal opening to the pharyngeal duct, of conventionally-housed rats was examined by light microscopy and scanning and transmission electron microscopy. Each lymphoid structure consisted of follicles containing T- and B-cell areas, and was covered with specialized epithelium. This epithelium consisted of cuboidal ciliated cells with oval nuclei parallel to the basal lamina. Goblet cells were sparse. Occasionally, islands of microvilli-bearing cells (so called membraneous or M cells) covered the lymphoid structures. M Cells were also found as single cells among the ciliated cells. The morphological characteristics and the particular localization justify the conclusion that the nasal lymphoid tissue described belongs to the mucosa-associated lymphoid tissue. It is therefore suggested that this nasal structure be designated nasal lymphoid tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229081
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  • 43
    Electronic Resource
    Electronic Resource
    Immunocytochemical and ultrastructural studies on allografts of the pituitary neurointermediate lobe in the third cerebral ventricle of the rat (1989)
    Springer
    Cell & tissue research 255 (1989), S. 393-404 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Neural lobe ; Intermediate lobe ; Intraventricular graft ; Immunocytochemistry ; Electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neurointermediate lobes from adult or 10-dayold rats were implanted by a stereotaxic procedure into the third ventricle of adult male rats, in an area close to the paraventricular nucleus. They were examined, using immunocytochemical and ultrastructural techniques, at times ranging from 1 week to 8 months. All grafts were recovered in a healthy condition although some rejection of the tissue was detected at the 1and 2-week stages. In the neural lobe, clusters of pituicytes were scattered among the loose network of capillaries, most of which had a fenestrated endothelium. The intermediate lobe remained organized in compact avascular lobules. Axons similar to those projecting into the neurointermediate lobe in situ, but also axons of other types (e.g., somatostatinergic, enkephalinergic) penetrated the grafts. Synapses with melanotrophic cells in the intermediate lobe and neurohaemal contacts in the neural lobe were frequent from 2 1/2 months after transplantation. Immunocytochemical and ultrastructural characteristics indicated intense secretory stimulation of the melanotrophic cells in the early stages. All cells enclosed in a same glandular lobule reacted in a similar manner. In later stages, when re-innervation occurred, the cells recovered their initial characteristics. The overall effect of the re-innervation of the intermediate lobe grafted in this location is inhibitory, as in the lobe in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224123
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  • 44
    Electronic Resource
    Electronic Resource
    Vasoactive intestinal polypeptide (VIP)- and neuropeptide Y (NPY)-containing nerve fibres in the penile cavernous tissue of green monkeys (Cercopithecus aethiops) (1989)
    Springer
    Cell & tissue research 256 (1989), S. 529-541 
    Details
    ISSN: 1432-0878
    Keywords: Penile erection ; Electron microscopy ; Immunohisto(cyto)chemistry ; Vasoactive intestinal polypeptide (VIP) ; Neuropeptide Y (NPY) ; Cercopithecus aethiops (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cavernous body of green monkeys contains many unmyelinated and few myelinated axons. The unmyelinated axons form terminals in the adventitia of the arteries, between trabecular muscle cells, in the interstitium, and close to endothelium cells of the sinuses. All terminals displayed predominantly “small clear vesicles” and very few “large granular vesicles”; “small granular vesicles” were not seen. However, in rabbit penises, terminals with many large granular vesicles are prominent. Immunohistochemistry (PAP technique) showed a dense network of VIP- and NPY-reactive fibres around the arteries and around trabecular muscles. The density of nerve fibres was particularly high around the subendothelial cushions of the helicine arteries. Double staining for NPY and VIP revealed that both peptides were colocalized. Immunocytochemistry (preembedding PAP technique) showed VIP- and NPY-reactivity in terminals with small clear vesicles; the reaction product was bound to the cytoplasmic face of different membrane types. Although the intracellular localization of the reaction product is probably due to artefactual displacement during preparation, the uniformity of the terminals questions the view that large and small granular vesicles in all species characterize peptidergic and noradrenergic terminals, respectively. The essential findings can be summarized as (1) a high degree of uniformity of nerve terminals, (2) colocalization of VIP and NPY, (3) heavy innervation of the subendothelial cushions of the helicine arteries, and (4) possible innervation of endothelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225601
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  • 45
    Electronic Resource
    Electronic Resource
    Granulated peripolar epithelial cells in the renal corpuscle of marine elasmobranch fish (1989)
    Springer
    Cell & tissue research 257 (1989), S. 61-67 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Peripolar cells ; Renal corpuscle ; Electron microscopy ; Raja erinacea, Mustelus canis, Rhinoptera bonasus, Sphryna lewini, Rhizoprionodon terraenovae, Squalus acanthias (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Granulated epithelial cells at the vascular pole of the renal corpuscle, peripolar cells, have been found in the kidneys of five species of elasmobranchs, the little skate (Raja erinaced), the smooth dogfish shark (Mustelus canis), the Atlantic sharpnose shark (Rhizoprionodon terraenovae), the scalloped hammerhead shark (Sphryna lewini), and the cow-nosed ray (Rhinoptera bonasus). In a sixth elasmobranch, the spiny dogfish shark (Squalus acanthias), the peripolar cells could not be identified among numerous other granulated epithelial cells. The peripolar cells are located at the transition between the parietal epithelium of Bowman's capsule and the visceral epithelium (podocytes) of the glomerulus, thus forming a cuff-like arrangement surrounding the hilar vessels of the renal corpuscle. These cells may have granules and/or vacuoles. Electron microscopy shows that the granules are membrane-bounded, and contain either a homogeneous material or a paracrystalline structure with a repeating period of about 18 nm. The vacuoles are electron lucent or may contain remnants of a granule. These epithelial cells lie close to the granulated cells of the glomerular afferent arteriole. They correspond to the granular peripolar cells of the mammalian, avian and amphibian kidney. The present study is the first reported occurrence of peripolar cells in a marine organism or in either bony or cartilagenous fish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221634
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  • 46
    Electronic Resource
    Electronic Resource
    Electron-microscopic study on the anterior pituitary gland of spontaneous dwarf rats (1989)
    Springer
    Cell & tissue research 258 (1989), S. 477-482 
    Details
    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; Electron microscopy ; Growth hormone ; Spontaneous dwarf rats (dr/dr)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The spontaneous dwarf rat is a novel experimental model animal on the study of pituitary dwarfism. The fine structure of the anterior pituitary cells was studied in the immature and mature dwarf rats. Pituitary glands were removed from 5-, 10-, 20-day-old immature dwarfs, adult (45 days-16 weeks) dwarfs and normal 3-month-old rats and processed for electron-microscopic observation. In the control animals, growth hormone cells were readily identified by their ultrastructural characteristics, such as the presence of numerous electron-dense secretory granules, 300–350 nm in diameter, well developed rough endoplasmic reticulum and a prominent Golgi complex. In contrast, growth hormone cells were not found in the anterior pituitary gland of the spontaneous dwarf rat at any age examined. Other pituitary cell types, i.e., luteinizing hormone/ follicle stimulating hormone, thyroid stimulating hormone, adrenocorticotropic hormone and prolactin cells, appeared similar in their fine structure to those found in the control rats. In the pituitary gland of dwarf rats, a number of polygonal cells were observed either with no or relatively few secretory granules. The rough endoplasmic reticulum was arranged in parallel cisternae and the Golgi complex was generally prominent in these cells. In addition, many were found to have abundant lysosomes. A few minute secretory granules were occasionally observed; however, the immunogold technique failed to localize growth hormone or prolactin in the granules. The nature of these cells remained obscure in this study. Since their incidence and fine structural features, other than the secretory granules, were quite similar to those of the growth hormone cells in normal rats, we postulate that these cells are dysfunctional growth hormone cells. These results suggest that the cause of the growth impairment in the spontaneous dwarf rat is due to a defect in the functional growth hormone cells in the pituitary gland, and since other pituitary cell types appeared normal, the disorder seems to be analogous to the isolated growth hormone deficiency in the human.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218859
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  • 47
    Electronic Resource
    Electronic Resource
    Light- and electron-microscopic investigation of the rat subcommissural organ grafted under the kidney capsule, with particular reference to immunocytochemistry and lectin histochemistry (1989)
    Springer
    Cell & tissue research 258 (1989), S. 499-514 
    Details
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Secretory activity, neural control ; Transplantation ; Long-spacing collagen ; Immunocytochemistry ; Molecular markers (neuronal, glial) ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary There is increasing evidence that, in the rat, a serotonin-mediated neural input may have an inhibitory influence on the secretory activity of the subcommissural organ (SCO). In the present investigation the rat SCO was studied 7, 30 and 90 days after transplantation under the kidney capsule, an area devoid of local serotonin-containing nerves. The grafted tissue was examined by use of immunocytochemistry employing a series of primary antisera, lectin histochemistry and transmission electron microscopy. The grafted SCO survived transplantation and contained, in addition to secretory ependymal and hypendymal SCO-cells, also elements immunoreactive with antisera against glial fibrillary acidic protein or S-100 protein. In transplants, SCO-cells produced a material displaying the characteristic immunocytochemical and lectin-binding properties of SCO-cells observed under in-situ conditions. The ependymal cells lined 1–3 small cavities, which contained secretory material. A fully developed structural equivalent of Reissner's fiber was, however, never found. The immunocytochemical and ultrastructural study of the grafted SCO showed an absence of nerve fibers within the graft and suggested a state of enhanced secretory activity. A network of protruding basal lamina structures connected the secretory cells to the newly formed capillaries revascularizing the SCO. One week after transplantation, long-spacing collagen started to appear in expanded areas of such laminar networks and also in the perivascular space. It is suggested (i) that the formation of long-spacing forms of collagen is triggered by factors provided by the SCO-secretory cells, and (ii) that secretory material of the ependymal and hypendymal cells may reach the reticular extensions of the basal lamina. In contrast to the SCO in situ, the grafted SCO-cells showed a positive immunoreaction for neuron-specific enolase. They became surrounded by a S-100-immunoreactive glial sheath that separated them from other transplanted cell types and the adjacent kidney tissue of the host.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218862
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  • 48
    Electronic Resource
    Electronic Resource
    Nucleus of the boar spermatozoon: Structure and modifications in frozen, frozen-thawed, or sodium dodecyl sulfate-treated cells (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 1 (1989), S. 264-277 
    Details
    ISSN: 1040-452X
    Keywords: Nucleoproteins ; Element concentrations ; Electron microscopy ; Image analysis ; X-ray spectrophotometry ; Flow cytofluorometry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: After cryosubstitution and Epon embedding, or after Nanoplast embedding and very thin sectioning, the chromatin of ejaculated or diluted boar spermatozoa appears to be formed of DNA fibers embedded in a quite homogeneous matrix. After sodium dodecyl sulfate (SDS) treatment, and to a lesser extent after freeze-thawing, the DNA fibers are present mostly between cords, probably proteinaceous in nature. The quantity of free sulfhydryl (SH) groups, as calculated from staining by DACM and flow fluorometry, is increased in thawed or SDS-treated cells. The quantity of NH2 groups, calculated from electron microscopy image analysis of alcoholic phosphotungstic acid-stained cells, is decreased in thawed nuclei. The DNA is more accessible to the fluorochrome ethidium bromide after freeze-thawing, and its sensitivity to HCI hydrolysis is modified, during the Feulgen-like staining procedure using acriflavine. The X-ray energy dispersive analysis of cryosections of nuclei indicates that the slight separation of DNA and nucleoproteins in freeze-thawed spermatozoa could result from a dramatic modification of the nuclear ionic environment during thawing.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080010407
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  • 49
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    Electronic Resource
    Applications of freeze-fracture replication to problems in materials and colloid science (1989)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 13 (1989), S. 309-334 
    Details
    ISSN: 0741-0581
    Keywords: Freeze-fracture ; Electron microscopy ; Rapid freezing ; Dispersions ; Polymers ; Gels ; Liquid crystals ; Emulsions ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Understanding the relationship between the molecular structure and the macroscopic properties of polymer solutions and gels, oil-water-surfactant emulsions, lyotropic and thermotropic liquid crystals, colloidal dispersions, detergents, and other such “microstructured fluids” is essential to the optimal use of these commercially important materials. Modern rapid-freezing methods followed by freeze-fracture replication techniques are ideally suited to allow the direct visualization of the three-dimensional structure of the particles or units that make up the dispersion, while simultaneously revealing their orientation and distribution with molecular resolution. This paper reviews the necessary experimental conditions required to successfully exploit the freeze-fracture technique as it applies to microstructured fluid systems. The benefits and limitations of structural studies by freeze-fracture techniques as opposed to the more commonly used light, X-ray, and neutron-scattering methods are discussed. Freeze-fracture replicas can also be imaged by scanning tunneling microscopy to reveal directly three-dimensional fracture contours with improved resolution.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060130406
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  • 50
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    Electronic Resource
    An electron microscopic study of the changes observed in osteocytes under ischemic conditions (1989)
    Hoboken, NJ [u.a.] : Wiley-Blackwell
    Journal of Orthopaedic Research 7 (1989), S. 12-21 
    Details
    ISSN: 0736-0266
    Keywords: Electron microscopy ; Ischemia ; Necrosis ; Osteocyte ; Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The purpose of this study was to observe the process of ischemia in osteocytes using light and electron microscopy and to compare the changes in these ischemic osteocytes with those in other types of osteocytes (i.e., degenerative osteocytes in physiological states, steroid-induced lipid-accumulating osteocytes) that have been previously reported. Five female Japanese white rabbits were used in this study. Osteochondral chips were taken from one side of the femoral condyle, covered with Millipore filters, and then inserted into the other side of the knee joint. These tissues were examined after 12 h and after 2, 5, 8, and 14 days of ischemia under both light and electron microscopy. Under light microscopy, osteocytes and lacunae were classified into four types: normal osteocyte, pyknotic osteocyte, pale osteocyte, and empty osteocyte lacuna. The number of each type of osteocyte (or lacuna) in a settled area was counted. The ratio of normal osteocytes decreased significantly (p 〈 0.001) after the second day of ischemia. Pyknotic osteocytes increased at 12 h (p 〈 0.01) and 2 days (p 〈 0.001) of ischemia. On the fifth day of ischemia, the percentage of pale osteocytes reached a peak. This was followed by a gradual increase in the number of empty lacunae. On the fourteenth day of ischemia, empty lacunac constituted 〉40% of the cell types. When viewed by electron microscopy, these necrotic osteocytes were similar to the degenerative osteocytes that have been observed in physiological states and apparently different from lipid-accumulating osteocytes. The results suggested that there could be at least two types of necrotic processes in osteocytes that eventually lead to cell death.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jor.1100070103
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  • 51
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    Electronic Resource
    Articular cartilage and intervertebral disc proteoglycans differ in structure: An electron microscopic study (1989)
    Hoboken, NJ [u.a.] : Wiley-Blackwell
    Journal of Orthopaedic Research 7 (1989), S. 146-151 
    Details
    ISSN: 0736-0266
    Keywords: Intervertebral disc ; Cartilage ; Proteoglycans ; Electron microscopy ; Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Articular cartilage and the intervertebral disc tissues have different material and biological properties and different patterns of aging and degeneration. To determine if the proteoglycans of these tissues differ in structure, we used the electron microscopic monolayer technique to compare baboon articular cartilage proteoglycans with baboon annulus fibrosus, transition zone, and nucleus pulposus proteoglycans. Intervertebral disc and articular cartilage porteoglycans differed signficantly. Articular cartilage contained large proteoglycan aggregates formed from hyaluronic acid central filaments, multiple monomers, and large nonaggregated monomers. These molecules were identical to those of nasal cartilage, growth plate cartilage, chondrosarcomas, or menisci. In contrast, the intervertebral disc tissues contained only nonaggregated proteoglycan monomers and clusters of monomers without apparent central filaments. Intervertebral disc nonaggregated monomers were shorter and more variable in length than those from articular cartilage, and nucleus pulposus nonaggregated monomers were even shorter and more variable in length than transition zone and annulus fibrosus monomers. These observations suggest that significant differences in proteoglycan metabolism exist between articular cartilage and intervertebral disc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jor.1100070121
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  • 52
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    Electronic Resource
    Adrenal chromaffin cells as transplants in animal models of parkinson's disease (1989)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 12 (1989), S. 308-315 
    Details
    ISSN: 0741-0581
    Keywords: Adrenal medulla ; Electron microscopy ; Transplantation ; Plasticity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The field of neural transplantation has moved rapidly forward in the last decade. Initially, fetal cells were used as implants to investigate their potential to ameliorate deficits in animal models of Parkinson's disease. However, because of the moral and legal problems associated with the use of fetal tissues in humans, alternative sources of donor tissue were sought which possessed the structural and functional characteristics needed to improve motor function in Parkinsonian patients. To date, one of the most promising tissues being investigated is the adrenal medulla, whose chromaffin cells possess an inherent plasticity of form and function. Transplanted chromaffin cells currently are being studied by a variety of approaches, including electron microscopy, in mouse, rat, and primate models of Parkinson's disease. An overview of the role of the chromaffin cell in this exciting and clinically important arena is briefly reviewed, with an emphasis on the fine structure of implanted chromaffin cells.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060120403
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  • 53
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    Electronic Resource
    Ultrastructural demonstration of exocytosis in the intact rat adrenal medulla (1989)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 12 (1989), S. 316-322 
    Details
    ISSN: 0741-0581
    Keywords: Secretion ; Electron microscopy ; Tannic acid ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Evidence is presented for morphological proof of exocytosis in the rat adrenal medulla in situ. Techniques were modified to allow perfusion of the intact adrenal gland with secretagogues (or electrical stimulation) followed by tannic acid. Unstimulated specimens demonstrated exocytotic (omega-shaped) profiles filled with flocculent material. This flocculation was also seen in the intercellular space. Stimulation of the adrenal medulla also resulted in the appearance of exocytotic profiles and an accumulation of the flocculent mass. This was often most evident in the subendothelial space. This is the first demonstration of exocytosis in the rat adrenal medulla by electron microscopy. The techniques used in this study will be useful for studying the pathway of secretory products of the adrenal chromaffin cell before they enter the vascular system.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060120404
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  • 54
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    Electronic Resource
    Quick-freeze, deep-etch, rotary-shadow views of the extracellular matrix and cortical cytoskeleton of Xenopus laevis eggs (1989)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 13 (1989), S. 228-243 
    Details
    ISSN: 0741-0581
    Keywords: Fertilization ; Freeze-fracture ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The quick-freeze, deep-etch, rotary-shadow technique provides a powerful tool to study the structural dynamics of extracellular matrices. Using this technique, we show that the extracellular investments of the Xenopus laevis egg are multilayered and securely anchored to the egg surface. The cortical cytoskeleton within the egg contains embedded cortical granules with surrounding endoplasmic reticulum and is capped by a thin reticular sheet that contacts the inner surface of the plasma membrane. The extracellular matrix undergoes three distinct changes at fertilization: (a) formation of a “smooth” layer below the vitelline envelope (VE), (b) transformation of the VE itself to an altered VE composed of concentric fibrous sheets, and (c) formation of a dense, “briar-patch”-like fertilization layer at the upper surface of the VE.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060130309
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  • 55
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    Differential morphometric values induced in Golgi apparatus of higher plant cells by aldehyde and permanganate fixation (1989)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 11 (1989), S. 1-8 
    Details
    ISSN: 0741-0581
    Keywords: Electron microscopy ; Fixation methods ; Golgi apparatus morphometry ; Onion roots ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In order to determine the best conditions to carry out quantitative ultrastructural studies in plant specimens, five different fixation techniques, including some of the most reported electron microscopy fixatives (glutaraldehyde-paraformaldehyde, osmium tetroxide, potassium permanganate), were assayed in onion root meristems to check their ability to induce morphometric changes in Golgi apparatus ultrastructure. Although the parameters evaluated showed in all cases the same tendency, values obtained after permanganate fixation were always higher than those found after aldehyde techniques (especially aldehyde-osmium). Aldehyde followed by osmium fixation appears as the most indicated fixation method when accurate quantitative ultrastructural studies are to be developed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060110102
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