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  • 1985-1989  (66)
  • 1970-1974
  • 1945-1949
  • 1840-1849
  • 1987  (66)
  • Electron microscopy
  • 1
    ISSN: 1437-160X
    Schlagwort(e): Chondrocalcinosis ; Calcium pyrophosphate dihydrate crystals ; Polymorphonuclear leukocyte ; Articular cartilage ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron microscopy was used to investigate the characteristics of calcium pyrophosphate dihydrate (CPPD) crystals in chondrocalcinosis (pseudogout syndrome). Crystals in midzone cartilage were frequently seen adjacent to chondrocytes. Great variation in crystal size and shape was observed. Most of the pyrophosphate crystals that had been phagocytosed by polymorphonuclear leukocytes of synovial fluid from patients with acute pseudogout were small (≦1 μm), indicating that small crystals can cause intense inflammation. Large numbers of polymorphonuclear leukocytes became attached to the eroded articular surface and phagocytosed microcrystals. Interaction of polymorphonuclear leukocytes with CPPD crystals in the superficial region of articular cartilage may stimulate the release of inflammatory mediators.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 65 (1987), S. 144-146 
    ISSN: 1432-1440
    Schlagwort(e): Campylobacter pyloridis ; Duodenal ulcer ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of campylobacter-like organisms found within duodenal biopsy specimens from 7 of 24 patients (28%) with active duodenal ulcer is described. Their curved shape and variable size are similar to what has previously been reported in descriptions of light microscopies. The organisms were found at the edge of active duodenal ulcers exclusively near neutral-mucous producing antral cells, to which they can adhere. The presence of these bacteria within cells and in the intercellular fluid implies that they can penetrate through the cell membrane or through tight intercellular junctions. The occurrence of these bacteria as well as numerous polymorphonuclear leukocytes in the afflicted regions suggests that the bacteria originally described by Warren and Marshall are indeed pathogenic and that their influence on ulcer healing should be included in designing treatment protocols.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular evolution 26 (1987), S. 347-357 
    ISSN: 1432-1432
    Schlagwort(e): Ribosome structure ; Electron microscopy ; Image analysis ; Evolutionary lineages
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Multivariate statistical analysis and classification techniques are powerful tools in sorting noisy electron micrographs of single particles according to their principal features, enabling one to form average images with an enhanced signal-to-noise ratio and a better reproducible resolution. We apply this methodology here to determining the characteristic views of the large (50S) ribosomal subunits from the eubacteriumEscherichia coli and the archaebacteriaMethanococcus vannielii, Sulfolobus solfataricus, andHalobacterium marismortui. Average images were obtained of the subunit in the common crown and kidney projections, but views of the particle in orientations intermediate between these two extremes were also elucidated for all species. These averages show reproducible detail of up to 2.0 nm resolution, thus enabling the visualization and interspecies comparison of many structural features as a first step toward comparing the actual three-dimensional structures. Our results disprove evolutionary lineages recently postulated on the basis of electron microscopical images of ribosomal subunits.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 410 (1987), S. 83-92 
    ISSN: 1432-2307
    Schlagwort(e): Buschke-Loewenstein tumour ; Giant condyloma ; Anogenital region ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Results on the light- and electron microscopic studies of six cases of Buschke-Loewenstein tumour are presented. The role of chronic irritation is emphasized in the aetiology of the tumour. Fistulas and abscesses arising in the tumour are dangerous as they give rise to chronic sepsis. In two perianal tumours, in situ or invasive carcinoma developed. Electron microscopy revealed varying degrees of differentiation of keratinocytes. As a result of the defective desmosomes, the tumour cell underwent segregation, with widened intercellular spaces containing oedema, erythrocytes and leucocytes. This phenomenon is probably responsible for frequent bleeding and fistula formation. The investigations disclosed that the Buschke-Loewenstein tumour is a special form of squamous carcinoma and therefore, radical surgical excision must be attempted even in case of a benign histological picture.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-2307
    Schlagwort(e): Thrombocytopenic purpura ; Idiopathic thrombocytopenic purpura ; Liver sinusoidal fibrosis ; Electron microscopy ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary 10 patients with thrombocytopenic purpura (TP) underwent splenectomy. Eight of these patients had idiopathic TP (certain or probable). All had normal liver function tests. Liver histology of the surgical biopsy was normal with the exception of a non specific mild portal infiltration in 6 cases. On Sirius red staining the perisinusoidal network was normal in 3 cases, mildly or moderately increased in 5 cases and often associated with perivenular fibrosis. Collagen types I, III, IV, laminin and fibronectin were increased in the 8 biopsies tested. On semi-thin sections, numerous Kupffer cells were observed. Under the electron microscope, sinusoidal abnormalities were very similar in all 7 patients studied: numerous Kupffer cells containing abundant lysosomes, numerous collagen bundles in the Disse space, active endothelial cells, transformation of some perisinusoidal cells into cells with some of the characteristics of fibroblasts (increased RER) and myofibroblasts (peripheral condensations of the filamentous network), increased fragments of basement membrane-like material. In two cases there was an increase in the number of perisinusoidal cells loaded with lipids. The similarity of the lesions and the absence of other fibrogenic causes (except in 2 cases) suggest that TP may represent another group of diseases with perisinusoidal fibrosis. The aetiology of fibrosis remains unknown but platelet derived growth factor and activated macrophages may play a major role.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 176 (1987), S. 251-258 
    ISSN: 1432-0568
    Schlagwort(e): Decidua ; Involution ; Electron microscopy ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Involution of the antimesometrial decidua was analysed by electron microscopy on days 9, 10 and 11 of pregnancy in the mouse. During this period, the width of the antimesometrial decidua decreases considerably. Involution begins in the decidual cells situated closest to the embryo (internal decidua) and proceeds towards the myometrium. The cells of the internal decidua showed signs of deterioration characterized by accumulation of clumps of chromatin in the nuclei and dilation of the perinuclear cisterna and endoplasmic reticulum cisternae. Autophagosomes and heterophagosomes accumulated in the cytoplasm of these cells. Cells particularly strongly affected became spherical and were devoid of their plasma membrane. Some cells near the trophoblast as well as the mature decidual cells situated farther from the embryo showed a normal morphology. The trophoblastic cells established close contact with healthy decidual cells and engulfed fragments of disorganized decidual cells. It is suggested that the death of decidual cells is a type of programmed cell death and that it is not due to a direct lytic action by the trophoblast.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 73 (1987), S. 370-378 
    ISSN: 1432-0533
    Schlagwort(e): Electron microscopy ; Factor VIII ; Glial fibrillary acidic protein ; Hemangioblastoma ; Tissue culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The histogenesis of stromal cells in capillary hemangioblastoma has been the subject of debate. The light and electron microscopic studies of hemangioblastomas presented here showed pericytic and leiomyoblastic features in stromal cells. Cells cultured by the monolayer method showed similar features to those of the original tumors. Immunohistochemical studies for glial fibrillary acidic protein and factor VIII/von Willebrand factor indicated that stromal cells were antigenically distinct from astrocytes and endothelial cells. These findings suggest that stromal cells are closely related to pericytes and smooth muscle cells, and support Rhodin's speculation that pericytes serve as a precursor to smooth muscle cells.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Acta neurochirurgica 88 (1987), S. 142-146 
    ISSN: 0942-0940
    Schlagwort(e): Electron microscopy ; immunohistochemistry ; pituitary ; rhabdomyosarcoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Intracranial extension of rhabdomyosarcoma from the face, nasopharynx or middle ear is rare. A 16-year-old boy presented with deterioration of vision and headache. CT scan revealed a soft tissue mass occupying the sphenoid and ethmoid sinuses, extending to the suprasellar fossa and impinging on the optic chiasm. The tumour, mimicking pituitary carcinoma, was removed by transsphenoidal craniotomy. Morphologic studies, including immunohistochemistry and electron microscopy, revealed that the tumour was a rhabdomyosarcoma. This case stresses the value of immunohistochemical and ultrastructural studies in the diagnosis of tumours occurring in the region of the sella turcica. The origin of this tumour was thought to be the sphenoid or ethmoid sinus. The pituitary gland appeared intact.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 75 (1987), S. 131-139 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral ischemia ; Hyperglycemia ; Substantia nigra ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Preischemic hyperglycemia induced by feeding or glucose infusion worsens the brain damage and the clinical outcome following ischemia of a given duration and density, and characteristically causes postischemic seizure activity. Light microscopy has previously showed that, in the rat, transient hyperglycemic ischemia induced by bilateral carotid occlusion in combination with arterial hypotension causes a uni- or bilateral lesion in the pars reticulata of the substantia nigra. Since this region has a central role in preventing seizure discharges the present study was carried out to determine the ultrastructural characteristics of this lesion. In rats with 10 min of transient hyperglycemic ischemia followed by recirculation for 1 to 18 h, the pars reticulata of the substantia nigra showed signs of status spongiosus, as well as extensive nerve cell alterations. These changes were observed after all recovery periods studied. The spongiotic appearance was mainly caused by swelling of dendrites and, to a lesser degree, by astrocytic swelling. The dendrites were expanded at all recovery times but the severity increased during the later periods of recirculation. These swollen dendrites contained severely expanded mitochondrias and endoplasmic reticulum. The cytoskeletal elements showed disordered lining of microtubules. Two major types of nerve cell alterations were present: a “pale” and a “dark” variety. The pale type was the most frequent cell alteration. It occurred in all experimental groups and at all time points. Redistribution of the nuclear chromatin and of cytoplasmic organelles as well as swelling of the same type as in the dendrites were the essential changes. The dark neurons were much fewer in number and occupied a peripheral position in the pars reticulata. Astrocytic foot processes appeared to be dilated around the dark neurons. Swelling of astrocyte processes was most pronounced in the 1 h recovery animals. Both types of neurons showed severe mitochondrial alterations of the type observed in dendrites. Occasionally, mitochondrial alterations were found in astrocytic processes as well. Blood vessel alterations were lacking. Previous studies have shown that in this model of ischemia the substantia nigra has a relatively well-preserved blood perfusion. In view of this the extensive histopathological lesions are surprising. We speculate that the lesions primarily involve excitotoxic damage to dendrites, with pronounced lactic acidosis playing a contributory role in causing axonal and glial pathology as well.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 176 (1987), S. 145-154 
    ISSN: 1432-0568
    Schlagwort(e): Neurological mutant mice ; ‘Purkinje cell degeneration’ (pcd) ; Weaver ; Neural transplants ; Cerebellum ; Light microscopy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Embryonic cerebellar grafts from genetically normal donors were implanted into the cerebellomedullary cistern of adult ‘Purkinje cell degeneration’ (pcd) and weaver mutant mice, which are respectively characterized by the selective loss of Purkinje and granule cells. Grafts placed into both mutant recipients exhibited a layered cellular organization reminiscent of the normal cerebellar cortex. Molecular, Purkinje, and granule cell layers were identifiable. Grafted Purkinje cells displayed characteristic cytological features, such as hypolemmal cisterns in association with mitochondria in the perikaryon, and lamellar structures in their axons. The cytological features of granule cell somata in the grafts appeared similar to those of mature granule cells. Electron microscopic examination of the molecular layer of the grafts revealed the presence of parallel fibers, which were not oriented in a parallel fashion; axon terminals of such fibers were often presynaptic to dendritic spines. The number of parallel fibers was markedly reduced in grafts implanted into both mutants compared to the normal cerebellar cortex; however, this phenomenon is commonly seen in cerebellum in tissue culture and in cerebellar transplants into normal hosts. It is concluded, therefore, that the environment of the mutant hosts does not affect the survival of Purkinje or granule cells and that transplantation of solid cerebellar grafts in the neurological mutants studied does not seem to pose any apparent limitations beyond those inherent to the process of cerebellar growth and differentiation outside its normal environment.
    Materialart: Digitale Medien
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 176 (1987), S. 525-530 
    ISSN: 1432-0568
    Schlagwort(e): Placenta ; Guinea pig ; Labyrinth ; Syncytiotrophoblast ; Tracers ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The permeability of the materno-fetal barrier in the chorioallantoic placenta was studied in guinea pigs with gestation at term applying a variety of electron-opaque tracers via maternal circulation. None of the tracers tested was seen permeating the syncytiotrophoblast in the materno-fetal direction up to a 20 min interval when the fine structure of the placenta was satisfactorily preserved. The lanthanum chloride, cationized ferritin and horseradish peroxidase bound to the trophoblast surface, apparently due to electrostatic forces more than to specific receptors, and no uptake of these probes was detected in the cytoplasm. Albumin-colloidal gold complex, also used as a tracer, yielded similar results. As reported in other species with more complex syncytiotrophoblastic organization, this layer investing maternal lacunae is a highly selective permability barrier.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 279 (1987), S. S30 
    ISSN: 1432-069X
    Schlagwort(e): Cicatricial pemphigoid ; Vegetating lesions ; Immunopathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case with widespread vegetating-pustular skin lesions, oral erosions, ulcerations and scarring, and conjunctival synechiae is reported. Clinically, histopathologically, and by immunofluorescence and electron microscopy this patient combined the features of pemphigoid vegetans, as described by Winkelmann and Su, and the mucocutaneous type of cicatricial pemphigoid. This observation suggests that a third subset of cicatricial pemphigoid can now be added to the two existing ones, the mucocutaneous and Brunsting-Perry types, and the designation vegetating cicatricial pemphigoid is proposed for this heretofore undescribed condition.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 75 (1987), S. 116-122 
    ISSN: 1432-0533
    Schlagwort(e): Rat ; Lead ; Brain edema ; Electron microscopy ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Newborn rats were exposed to daily intraperitoneal injections of 10 mg lead nitrate per kg body weight for the first 15 postnatal days. The growth and mortality of the lead-exposed animals did not differ from their control litter-mates, injected with vehicle only. In our previous studies, focal hemorrhages and spongy areas as well as breakdown of blood-brain barrier to plasma proteins were shown by light microscopy in the cerebellar parenchyma of 15-day-old rats exposed to this dose. In spite of these signs of edema, measurements of brain tissue specific gravity did not show increased water content. In the present investigation we examined the ultrastructure of the brain lesions in these rats with low-dose lead encephalopathy, focusing on signs of edema, and evaluated astroglial reaction by immunocytochemical staining for glial fibrillary acidic protein (GFAP). The electron microscopic findings were compatible with extracellular edema in the cerebellum of 15-day-old lead exposed rats. The number of GFAP-positive cell bodies in the gray substance of the cerebellar cortex was increased in the 15-day-old lead-exposed rats as compared with the controls of the same age, a finding which is presumably related to the leakage of plasma proteins. Both these findings were lacking at 20 days of age, suggesting reversibility of the lead-induced changes.
    Materialart: Digitale Medien
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  • 14
    ISSN: 1432-0533
    Schlagwort(e): Pleomorphic xanthoastrocytoma ; Epithelial properties ; Circumscribed growth ; Electron microscopy ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Three cases of pleomorphic xanthoastrocytoma (PXA), one of which showed anaplastic evolution, are described. In all three the PXA tumors were well circumscribed and could be totally removed. Light-microscopically, pleomorphic tumor cells clustered gregariously and often formed alveolar structures. Electron microscopy revealed various epithelial properties, such as junctions and interdigitations between apposing tumor cells, and prominent basal laminae surrounding tumor nests. The circumscribed growth of PXA, as contrasted with an infiltrative growth of usual astrocytoma, can be attributed to the cellular cohesion based on the epithelial properties of the tumor cells. In the third patient, tumor recurred 6 months postoperatively. Although the recurrent tumor retained the alveolar structures, pleomorphism and various degenerative features of the tumor cells diminished with advance in the proliferative activities.
    Materialart: Digitale Medien
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 74 (1987), S. 169-178 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral gangliocytoma ; Parieto-frontal lobe ; Intracytoplasmic inclusion bodies ; No synapse ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We report a case of cerebral gangliocytoma (GC) with a variety of unusual structures in the tumor cells. Light microscopically, the tumor consisted of typical ganglion cells, atypical cells which has argyrophilic granules in the cytoplasm, and a few astrocytes. Electron microscopically, the tumor cells showed typical gangliocytic features, which had abundant rough endoplasmic reticula, ribosomes and cored vesicles of 90–150 nm diameter, a few 50-nm-diametered non-cored vesicles, and other common organelles in their cytoplasm. Furthermore, neoplastic ganglion cells contained a variety of abnormal structures, including membranous cytoplasmic bodies (MCB), Zebra bodies (ZB), tubular structures, branched tubular structures (BTS), concentrical laminated bodies and curvilinear bodies (CB). The MCB, ZB and CB resembled those in GM2 gangliosidosis (GMG), and the BTS that in infantile neuroaxonal dystrophy (INAD). Although the significance of these inclusions is still unknown, it is considered that some common mechanism might play a role in the metabolism of both neoplastic neuronal cells and degenerating neurons (GMG and INAD). Synapses could not be observed anywhere despite complete neuronal differentiation of many tumor cells.
    Materialart: Digitale Medien
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  • 16
    ISSN: 1432-0533
    Schlagwort(e): Hypoglycemia ; Rat striatum ; Glutamate ; Excitotoxic nerve cell injury ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In rat striatum severe hypoglycemia causes an irreversible nerve cell injury, which does not become manifest until during the post-insult recovery period. This injury can be ameliorated by lesions of the glutamatergic cortico-striatal pathway, which suggests that an “excitotoxic” effect mediated by the glutamatergic input is the likely cause of the posthypoglycemic nerve cell destruction. In this paper we further characterize the protective effect of abolishing the glutamatergic innervation to striatum at the ultrastructural level. Two weeks after a unilateral cortical ablation rats were subjected to 30 min of severe hypoglycemia with isoelectric EEG and killed either immediately after the insult or following 60 min of recovery induced by restoring the blood glucose levels. Immediately after the hypoglycemic insult the structure of striatum was similar on both sides (except for the changes attributable to the ablation); i.e., the neurons and their dendrites had pale cytoplasm with condensed mitochondria, sparse RER and pinpoint ribosomes. After 60 min restitution numerous striatal neurons on the non-protected, non-ablated side had turned variably dark and condensed, whereas under-neath the ablation they remained similar as immediately after hypoglycemia. This sequence indicates that the most likely cause of nerve cell destruction on the non-protected side is the “excitotoxic” effect mediated by the glutamatergic innervation, which is superimposed on the action of the hypoglycemic insultper se. Furthermore, the primary condensation of neurons and their dendrites indicate existence of another type of acute “excitotoxic” nerve cell injury which differs from the previously described injury characterized by neuronal swelling.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 72 (1987), S. 341-348 
    ISSN: 1432-0533
    Schlagwort(e): Carbon disulphide neuropathy ; Pacinian corpuscles ; Denervation and reinnervation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Adult Wistar rats were exposed to carbon disulphide vapours at a concentration of 2.4 mg/l of air for 5 days a week (6 h a day), and the ultrastructure of Pacinian corpuscles and their nerve supply was investigated after 6 months of exposure. Both degenerative and regenerative changes were observed in sensory axons and the corpuscles. In a sample of corpuscles examined, 30% were denervated and about 60% showed clear signs of reinnervation. Some of the reinnervated corpuscles were supplied by unmyelinated axons. In others, one to three myelinated axons were already found at the nerve entry. The axons branched and formed three to eight terminals in the inner core. Due to continuous intoxication, most regenerated terminals were again undergoing degeneration. In peripheral nerves, the evidence of axonal regeneration has been reported in various toxic distal axonopathies. However, the reinnervation of Pacinian corpuscles has not been described before. It can be expected that reinnervation of Pacinian corpuscles and other end-organs also occurs in other axonopathies, if not during continuous poisoning, then at least after its cessation.
    Materialart: Digitale Medien
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  • 18
    ISSN: 1432-0533
    Schlagwort(e): Herpes simplex virus type 2 ; Genital infection ; Avidin-Biotin Method ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Mice were infected by the vaginal route with the MS strain of herpes simplex virus type 2 (HSV-2). Serial vaginal cultures were used to confirm infection and to select mice for this study. Two mice were killed by perfusion on days 2–6 post infection (p.i.) and lumbar and sacral cord with cauda were fixed and embedded for electron microscopy. Semithin Epon-sections were stained for viral antigen using a rabbit anti-HSV-2 antiserum and the Avidin-Biotin (ABC) method. Thin sections from antigen-positive blocks were examined by electron microscopy, and the number and types of infected cells detected by these two methods were compared. A good correlation was found between detection of infected cells by these methods. Infected cells included neurons of dorsal root ganglia and spinal cord, satellite cells of dorsal root ganglia, non-myelinating Schwann cells, astrocytes, oligodendrocytes and arachnoidal cells. Infected cells were first detected in the cauda on day 3 p.i. and in the spinal cord on day 5 p.i. The temporal and spatial distribution of infected cells was consistent with neural spread to and within the CNS. The pathological lesions showed a good correlation with the distribution and number of infected cells and are probably due to a direct virus effect. The similar sensitivity of the Epon-ABC method to electron microscopy in detecting infected cells indicates that this method may have useful applications in both experimental and diagnostic work.
    Materialart: Digitale Medien
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 73 (1987), S. 62-66 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral calcification ; Fahr's disease ; Electron microscopy ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of idiopathic nonarteriosclerotic cerebral calcification was studied post mortem by histochemical and scanning and transmission electron microscopic methods. Calcification was found bilaterally in the basal ganglia, cerebral cortex, granular layer and white matter of the cerebellum. Histochemical examination revealed that deposits were composed of a mixture of glycoproteins, mucopolysaccharides, calcium salts and iron. Transmission electron microscopy revealed minute deposits mainly in the cytoplasm of adventitial cells of blood vessels and sometimes in the cytoplasmic processes of glial cells. Scanning electron microscopy showed that some of the spherical and hemispherical bodies, which were formed in the adventitial cells of blood vessels, were connected with filamentous cytoplasmic processes of surrounding cells. Small uncalcified deposits occurring in the cytoplasm of the adventitial cells had subsequently had minerals deposited in them. Some kind of impairment of the pericytes may play an important role at the onset of this disease.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 279 (1987), S. 270-272 
    ISSN: 1432-069X
    Schlagwort(e): Atopic eczema ; Hyperlinear palms ; Autosomal dominant ichthyosis vulgaris ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 279 (1987), S. 167-172 
    ISSN: 1432-069X
    Schlagwort(e): Morphometry ; Electron microscopy ; Cytological atypia ; Nevus cells ; Melanoma cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cytological atypia, revealed in the course of routine light microscopy, is considered a valuable indicator of malignancy in melanocytic lesions. A clear definition of the term cytological atypia, however, is lacking. Therefore, by morphometric analysis of ultrathin sections of 11 malignant melanomas (7 invasive, 3 in situ, and 1 lentigo maligna melanoma) and 10 compound nevi, we evaluated the discriminating power of the various facets of cytological atypia, i. e., nuclear area, area of the nucleolus, area of the total cell, and nuclear irregularity. In each case, at least 50 intraepidermal melanocytic cells were examined. The two-sided U-test showed significant differences between intraepidermal nevus and melanoma cells, with regard to the mean values (x) and standard deviations (s) of the nuclear area (x and s, p=0.00011), area of the nucleolus (x, p=0.00043; s, p=0.00011), and area of the total cell (x, p=0.00011; s, p=0.00093). However, only the mean values and standard deviations of the nuclear area allowed a clear distinction in each individual case. The area of the nucleus can be estimated in the course of routine histology. We therefore think that the size and variation of the nuclear area should be considered in the histological differential diagnosis between malignant melanomas and benign nevi.
    Materialart: Digitale Medien
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 279 (1987), S. 308-314 
    ISSN: 1432-069X
    Schlagwort(e): Congenital cutis laxa ; Collagen synthesis ; Electron microscopy ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of congenital cutis laxa (CCL) of unclear mode of inheritance associated with multiple pulmonary artery branch stenosis was extensively investigated to assess possible correlations between clinical, ultrastructural, and biochemical features. Light microscopy revealed that elastic fibers were absent in the papillary dermis, while hypoplastic elsewhere. Transmission electron microscopy showed a poor elastin matrix content in some elastic fibers, variable diameters of collagen fibrils, and abundant glycogen granules in most dermal cells. Measurement of collagen fibril diameters, using an image analyzer, was carried out in the patient and two age- and site-matched controls. A biomodal distribution was found in the upper reticular dermis of the patient. In vitro analysis of collagen in skin fibroblast cultures of the patient showed increased collagen synthesis with a balanced production of type I and type III procollagens. Our study confirms that CCL represents a disorder both of collagen and elastic connective tissue.
    Materialart: Digitale Medien
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Acta neurochirurgica 85 (1987), S. 56-62 
    ISSN: 0942-0940
    Schlagwort(e): Electron microscopy ; erythropoietin ; haemangioblastoma ; immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Immunohistochemical studies for erythropoietin were carried out in six capillary haemangioblastomas, three of which were also studied by electron microscopy. The immunohistochemical studies showed that positively stained cells were scattered in the vicinity of capillaries, and that neither endothelial cells nor stromal cells were stained. In their morphology and distribution, the positively stained cells were identical to mast cells as observed by electron microscopy. In one case, erythropoietin was demonstrated in the cyst fluid of the tumour. These findings suggest that mast cells with abundant secreting granules in haemangioblastomas are capable of producing erythropoietin.
    Materialart: Digitale Medien
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 113 (1987), S. 392-399 
    ISSN: 1432-1335
    Schlagwort(e): Paget's disease of bone ; Osteosarcoma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The authors report 12 cases (8 men and 4 women) of sarcomatous degeneration in Paget's bone disease, with an average age of 72.3 years. Sarcomatous degeneration occurred often in polyostotic Paget's disease, and osteitis deformans was seen in 4 cases. Femur and pelvis were the most affected bones. Pain was a constant feature, whereas tumefaction and fracture were less common. Osteolytic lesions were more frequent than condensed or mixed lesions and radiological signs of malignancy were usually found. Seven cases were histologically clasiified as osteogenic sarcoma and 3 cases as fibrosarcoma. Electron microscopy was performed on 2 osteogenic sarcomas and in 1 case revealed microcylindrical inclusion in Pagetic osteoclasts and in multinucleated giant tumor cells, but none in mononucleated tumor cells. The average survival time for the patients in this study was only 4.5 months.
    Materialart: Digitale Medien
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  • 25
    ISSN: 1432-1106
    Schlagwort(e): Ventral mesencephalic grafts ; Electron microscopy ; Afferent synapses ; Tyrosine hydroxylase immunocytochemistry ; Dopaminergic neurons ; Dopaminergic boutons
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In adult rats with a unilateral 6-hydroxydopamine-induced lesion of the nigrostriatal dopamine pathway, grafts of embryonic ventral mesencephalon can establish extensive efferent connections with the previously denervated host neostriatum and can compensate for motor and sensorimotor asymmetries induced by the lesion. The object of this study was to examine the afferent synaptic inputs to grafted dopaminergic neurons, implanted into a cortical cavity overlying the previously denervated caudate-putamen, using electron microscopic immunocytochemistry. The dopaminergic neurons of the grafts in the same animals had previously been shown to re-innervate the host neostriatum, to form synaptic connections therein and to attenuate the lesion-induced motor asymmetry that occured in response to amphetamine (Freund et al. 1985). In the light microscope, the grafts were found to contain numerous tyrosine hydroxylase-immunoreactive perikarya, dendrites, axons and axonal swellings which had distinct distributions. In addition axons and axonal swellings that were immunoreactive for either substance P or glutamate decarboxylase were present. Electron microscopic analysis of the boutons contacting tyrosine hydroxylase-immunoreactive neurons in the grafts revealed the presence of at least five distinct types of afferent synaptic boutons based on their immunochemistry, morphology, or types of membrane specialization. One type was itself immunoreactive for tyrosine hydroxylase; such synapses are extremely rare in the intact substantia nigra, none were found in the contralateral substantia nigrae or the substantia nigra of a control rat. Three of the remaining types had ultrastructural features that were similar to synaptic terminals that were immunoreactive for substance P or glutamate decarboxylase. These synapses were similar to the types of synapses found contacting dopaminergic neurons in the substantia nigra contralateral to the graft or the substantia nigra of a control rat. The results demonstrate that, in the absence of the normal extrinsic afferent inputs, the intracortical mesencephalic grafts have a well-developed local synaptic circuitry. It is suggested that local circuit regulation of dopaminergic neurons within the graft may, at least in part, be responsible for the maintenance of a normal or close to normal functional activity.
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 66 (1987), S. 175-184 
    ISSN: 1432-1106
    Schlagwort(e): Dorsal column nuclei ; Gracile nucleus ; Inferior olive ; Dorsal accessory olive ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This study examined the termination pattern within the dorsal accessory subdivision of the cat inferior olive of axons arising from the gracile nucleus. The gracile terminals were labeled by anterograde transport of wheat germ agglutinin complexed to horseradish peroxidase and visualized with tetramethyl benzidine. Gracile terminals were found to contain round synaptic vesicles and form asymmetric synaptic contacts. Of particular interest was the finding that gracile axons, like axons from the spinal cord, terminate primarily outside of synaptic glomeruli. Yet most of the gracile terminals did not synapse on isolated dendritic elements. Rather, the majority contacted distal dendrites which directly contacted other dendritic elements, forming simple complexes termed dendritic thickets. Typically the dendritic thickets were composed of two or three dendrites that received input from more than one round vesicle-containing synaptic terminal. Only one terminal per thicket was labeled by injections in the gracile nucleus. This clustering of pre-and postsynaptic elements within the thickets provides opportunities for many of the same interactions allowed by synaptic glomeruli, in particular divergence and convergence of information.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 67 (1987), S. 380-390 
    ISSN: 1432-1106
    Schlagwort(e): Adrenal medulla ; Periaqueductal gray ; Neural implants ; Analgesia ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Recent findings in our laboratory indicate that adrenal medullary grafts produce significant alterations in pain sensitivity. Electron microscopic studies were undertaken to correlate these behavioral changes with the neural interactions of the host and graft tissue in the periaqueductal gray. A striking change found 8 weeks after transplantation is that pronounced myelination has taken place both in the graft and in the host tissue. The new myelin formation in the graft has the typical appearance of PNS myelination and, in the host the appearance of CNS myelination. The endothelial cells of the capillaries in the grafted tissue are attenuated and fenestrated in contrast to those of the surrounding parenchymal tissue of the host. By 8 weeks, the graft becomes heavily encapsulated with collagen, while the host CNS tissue develops layers of glial processes outlining the graft. However, collagen and glial layers apparently do not form an absolute barrier to either cellular or humoral interaction between the host and graft tissue. Chromaffin cells can be found protruding into the host CNS tissue and sometimes forming synapses with presumably the host neuronal processes. Grafted chromaffin cells may participate as both postsynaptic and, less often, as presynaptic components of synaptic junctions. The behavioral relevance of these synaptic contacts is unclear, since similar implants of adrenal medullary tissue into the dorsal spinal cord subarachnoid space, which also induce potent analgesia, do not contain synapses. Thus, it is more likely that behavioral changes are brought about by diffusion of neuroactive substances from grafted chromaffin cells to host receptors.
    Materialart: Digitale Medien
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  • 28
    ISSN: 1432-0983
    Schlagwort(e): Electron microscopy ; Replicative intermediates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Some physicochemical properties of the mitochondrial DNAs (mtDNA) from plants of flax, broad bean and mung bean, and from tissue culture cells of jimson weed, soybean, petunia and tobacco were determined. Circular molecules were observed in electron microscope preparations of each mtDNA. In soybean, petunia, broad bean and mung bean mtDNAs, the circular molecules had a continuous distribution of lengths (ranges between 1 to 36 kb, and 1 to 126 kb), heavily skewed toward smaller molecules. Eighty-six percent of the flax circular molecules were from 27 to 54 kb in size, and 78% of the jimson weed circular molecules were from 4 to 15 kb. Replicative forms of 1.2–1.6 kb circular molecules were observed in electron microscope preparations of broad bean mtDNA.
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  • 29
    ISSN: 1432-0738
    Schlagwort(e): Isopropyl alcohol ; Tracheal mucosa ; Ciliary activity ; Recovery process ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The toxicity of isopropyl alcohol (IPA) on the tracheal mucosa was studied experimentally with special reference to the recovery process of the organ. The results showed that 400 ppm IPA has an acute effect on the mucociliary system in the tracheal mucosa, and that recovery from such degeneration can occur in 2 weeks. When functional and morphological damage was induced by a higher level (5500 ppm) of IPA, recovery did not occur in 2 weeks. The conclusion is that the present allowable level of IPA is reasonable from the viewpoint of the effects of short-term exposure to IPA on the tracheal mucosa. In addition, a higher level of IPA exposure has longer-term effects on the tracheal mucosa, and workers exposed to such a higher level of IPA vapor should be given careful otolaryngological follow-up observations.
    Materialart: Digitale Medien
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Archives of toxicology 59 (1987), S. 385-390 
    ISSN: 1432-0738
    Schlagwort(e): Lung ; Methyl isocyanate ; Gas poisoning ; Electron microscopy ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The static exposure of rats to 0.25 mg/l methyl isocyanate for 1 h resulted in damage to the epithelium of the proximal bronchioles and upper airways. Bronchiolar cells exhibited both nuclear and cytoplasmic damage; many epithelial cells, particularly in the bronchi and trachea, were killed and/or dislodged from the basement membrane. A “raft” of cell debris and fibrin lined most of the airways during the 1st week after exposure but repair to the underlying epithelium was well advanced within 2–3 days. The majority of airways were lined by a normal epithelium within 3 weeks of exposure, but isolated foci of hyperplasia and occluded airways probably accounted for continued respiratory impairment.
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Child's nervous system 3 (1987), S. 74-80 
    ISSN: 1433-0350
    Schlagwort(e): Medulloblastoma ; GFAP-positivity ; Electron microscopy ; Postoperative follow-up
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Eighty-four cases of medulloblastoma were examined immunohistochemically and 12 by electron microscopy to assess differentiation in these tumors. Based upon the largest series of medulloblastoma studied to date, we demonstrated glial fibrillary acidic protein (GFAP) positivity, in 25% (21/84) of these tumors showing glial differentiation. GFAP-positive cells were seen more frequently in the desmoplastic variant of medulloblastoma (7/10). Under electron microscopy, the major part of the 12 tumors studied appeared primitive and undifferentiated. In 7 cases, groups of cells were found with primitive neuronal and/or glial features. GFAP positivity was confirmed at light microscopy level in all cases where cells showed glial differentiation in the form of glial-like filaments in cytoplasma. However, a follow-up questionnaire study of those patients who had received only surgical treatment revealed no difference in mean survival time between GFAP-positive and GFAP-negative medulloblastoma.
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  • 32
    ISSN: 1432-2013
    Schlagwort(e): Sugar transport ; Electron microscopy ; Chicken cecum and jejunum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have investigated the possible relation between the phloridzin-sensitive influx of α-methyl-D-glucoside (concentration 5 mmol/l) and the brush border surface area, in chicken isolated enterocytes. The intestinal regions studied were: jejunum and proximal cecum (both with high affinity sugar transport sites), medial cecum (with a low affinity transport system) and distal cecum (which lacks any transport ability). Cell apical surface measured by electron microscopy gave the following results; jejunal cells (0.41 μm2) 〉proximal cecal cells (0.23 μm2)〉medial cecal cells (0.15 μm2)=distal cecal cells (0.14 μm2). This parameter is mainly determined by the length of microvilli. Sugar influx studies showed that the concentration of the substrate in cell water (in mmol/l) was jejunum (7.1)〉proximal cecum (2.9) 〉medial cecum (1.7)〉distal cecum (not different from zero). The decline in influx rate from proximal to distal cecum may be explained both by changes in surface and by the different carriers involved (differentK m). Results of sugar concentration in the distal cecal cells do not correlate with the other segments studied since the substrate enters in these cells by a passive process. It is concluded that the degree of development of microvilli should be taken into account when estimating nutrient transport rates in different intestinal segments.
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 411 (1987), S. 311-314 
    ISSN: 1432-2307
    Schlagwort(e): Human pituitary adenomas ; Granules ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined by transmission electron microscopy. Double membrane bound bodies with filamentous internal structure identical to rodent light bodies were identified in 10 hormone-producing adenomas: 5 PRL, 1 PRL-GH, 2 GH, and 2 ACTH-producing tumours. No light bodies were found in the remaining 79 tumours nor in the pituitary cells in periadenomatous tissue from 20 cases. These results show that some human pituitary adenomas may contain light bodies identical to those seen in gonadotrophs of rat pituitary.
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  • 34
    ISSN: 1432-0878
    Schlagwort(e): Mammary gland ; Tissue culture ; Collagen gel ; Electron microscopy ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Fragments of human breast epithelium, devoid of all stromal and basal lamina components, which maintain their in vivo topological organisation can be cultured for up to 28 days within a reconstituted rat-tail-derived collagen matrix. These organoids initially undergo a loss of structural and 3-dimensional organisation, typified by loss of lumina formed by epithelial cells, and myosin from myoepithelial cells. Their subsequent reorganisation is dependent on the presence of serum, insulin, hydrocortisone, and cholera toxin in tissue culture medium. After this preliminary phase, a reduction in the concentration of serum, insulin, hydrocortisone, and cholera toxin is necessary to allow the structural differentiation of epithelial and myoepithelial cells. The myoepithelial cells also regain their ability to produce the basal lamina component laminin. The use of bovine-dermal collagen as the matrix, rather than rat-tail-derived collagen is shown to result in more stable organisation and differentiation of the organoids. The successful use of single-cell pellets (derived by trypsinisation of the organoids) in place of organoids in such cultures illustrates that there is no requirement for pre-existing cell/ cell contact or topological organisation of cells prior to embedding within the collagen matrix.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 247 (1987), S. 457-459 
    ISSN: 1432-0878
    Schlagwort(e): Vomeronasal glands ; Autonomic innervation ; Electron microscopy ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The morphological evidence for a direct autonomic innervation of the mouse vomeronasal glands is presented. Axonal varicosities containing a few densecore vesicles and numerous clear vesicles (36–60 nm in diameter) make synaptic contacts with the secretory cells at the base of the glandular acini. The axonal presynaptic membrane is associated with a distinct dense material and it is separated from the secretory cell by a synaptic cleft of about 12–14 nm. At the postsynaptical level, coated vesicles can be found. Additional postsynaptical specializations have not been observed.
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 248 (1987), S. 49-54 
    ISSN: 1432-0878
    Schlagwort(e): Enterochromaffin cells ; Serotonin ; Duodenum ; Immunocytochemistry ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Enterochromaffin cells of the rat duodenum have been studied immunocytochemically by use of a specific antiserum to serotonin. At the light-microscopic level serotonin immunoreactivity was observed in enterochromaffin cells located in the epithelium of the duodenal mucosa. Most of the serotonin-immunoreactive material was localized to the basal portion of the enterochromaffin cells, but small amounts of immunoreactive material were regularly observed in the apical portion. At the electron-microscopic level serotonin immunoreactivity in enterochromaffin cells was found to be concentrated over the dense cores of the cytoplasmic granules. The majority of these granules was located in the basal cytoplasm of the enterochromaffin cells, but serotonin-immunoreactive granules were also observed in the apical cytoplasm immediately beneath the microvilli. These observations indicate that duodenal enterochromaffin cells are bipolar and that they secrete serotonin both basally, to the circulation, and apically, to the gut lumen. Rat duodenal enterochromaffin cells thus appear to have an exocrine as well as an endocrine function.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 248 (1987), S. 675-682 
    ISSN: 1432-0878
    Schlagwort(e): Molluscan muscles ; Innervation ; Chromatophores ; Cephalopods ; Electron microscopy ; Eledone cirrhosa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cephalopod chromatophores are made of a central pigment cell surrounded by 10 to 20 radially arranged muscle fibres under direct nervous control. Innervation of these muscle fibres was studied with anterograde cobalt fills of peripheral nerve bundles and light and electron microscopy. Individual axons branch repeatedly to innervate the muscles of chromatophores scattered over several millimeters. Axons contained in several dermal nerves converge to innervate the same chromatophores. Among the chromaophores, axons were found running either singly or in small bundles, often accompanied by sheath cells. Single chromatophore muscles were innervated by at least one axon running across or along its length. Since nerves terminating on chromatophore muscles are very rare, neuromuscular contact seems to be made “en passant”. Varicosities of the axons apposed to the muscles are thought to be presynaptic sites. However, morphological differentiations of the pre-or post-synaptic membranes were not visible. Two types of innervating processes were found containing either electron-clear or a mixture of electron-clear and dark-core synaptic vesicles.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 248 (1987), S. 393-398 
    ISSN: 1432-0878
    Schlagwort(e): Adrenaline ; Phenylethanolamine-N-methyl transferase ; Immunocytochemistry ; Electron microscopy ; Central nervous system ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of adrenergic axon terminals was examined in the paraventricular nucleus of the thalamus (PNT) and in the hypothalamic arcuate nucleus-median eminence (ARC-ME) complex by use of phenylethanolamine-N-methyl transferase (PNMT) immunocytochemistry. In the PNT, immunoreactive terminals formed a dense and well-circumscribed plexus. In the ARC, labeled varicosities were less numerous and more evenly distributed. In the ME, they were scarce and confined to the inner zone. In all these areas, the diameter of immunoreactive varicosities ranged between 0.2 and 1.3 μm; in the ME and in the transitional zone between the ARC and the ME, a population of larger boutons (〉2 μm) was also visible. All immunoreactive varicosities exhibited densely packed small, clear vesicles associated with a few large granular vesicles. In the PNT and the ARC, but not in the ME, they formed synaptic contacts with dendritic elements and were occasionally apposed to neuronal cell bodies. These axo-somatic appositions showed no junctional specializations. In the ME and transitional zone, immunoreactive terminals were frequently juxtaposed to, and occasionally established differentiated synaptic contacts with, tanycytes. These data support a transmitter role for adrenaline in the diencephalon and suggest that adrenaline plays a role in hypothalamo-hypophysiotropic regulation through interactions with neural and glial elements.
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 248 (1987), S. 169-180 
    ISSN: 1432-0878
    Schlagwort(e): M-band structure ; Fibre type ; Skeletal muscle ; Cryo ultramicrotomy ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the M-band in soleus (SOL) and extensor digitorum longus (EDL) muscles in newborn and four-week-old rats was studied using electron-microscopic techniques. In newborn rats, all myotubes and fibres in both muscles had an identical myofibrillar appearance. A five-line M-band pattern was seen in longitudinal sections and distinct M-bridges in cross-sections. The Z-discs were of medium width. On the other hand, in four-week-old rats, different muscle fibre types were observed on the basis of their myofibrillar pattern. In SOL two fibre types were distinguished in longitudinal sections. One had a four-line M-band pattern and very broad Z-discs, whereas the other type had five lines in the M-band and broad Z-discs. In EDL, three different myofibrillar patterns were observed. The M-bands were composed of three, four or five lines. Fibres had either thin, broad or medium Z-disc widths, respectively. In cross-sections of the SOL muscle one group of fibres showed indistinct M-bridges, whereas distinct M-bridges were seen in the other fibres and in all observed EDL muscle fibres. We conclude that initially there seems to be a single intrinsic program for M-band genesis; this program becomes modified upon the induction of functionally differentiated fibres.
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  • 40
    ISSN: 1432-0878
    Schlagwort(e): Human growth hormone-releasing factor (hGRF) ; Paraventricular nucleus ; Immunocytochemistry ; Electron microscopy ; Synapses ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary By means of a preembedding immuno-electronmicroscopic technique, a large number of nerve endings containing a substance related to human growth hormonereleasing factor (hGRF) have been demonstrated in the paraventricular nucleus of the guinea pig. They made synaptic contacts primarily with dendritic shafts: 80% of these contacts were symmetrical. The immunoprecipitate was located mainly in large granules and around small clear vesicles. These findings suggest that a peptide related to hGRF may play a role in neural communication in the paraventricular nucleus.
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 247 (1987), S. 167-177 
    ISSN: 1432-0878
    Schlagwort(e): Arteriovenous anastomoses ; Autonomic innervation ; Synaptic vesicles ; Histochemistry ; Electron microscopy ; Tongue ; Dog
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The innervation of the arteriovenous anastomoses in the dog tongue has been investigated. At the lightmicroscopic level, the vessels were found to be densely supplied with adrenergic and AChE-positive nerve plexuses and less densely with the quinacrine-binding nerve plexus. At the electron-microscopic level, at least two apparently different types of axon profiles were identified: 1) Small vesicle-containing axons, characterized by many small granular vesicles, variable numbers of small clear vesicles and large granular vesicles. Storage of endogenous amines and uptake of exogenous amines into most small granular vesicles and many large granular vesicles was demonstrated. These axons stained only lightly with reaction products for AChE activity and thus seemed to be adrenergic in nature. Some axons contained numerous large granular vesicles, whose cores occasionally stained with uranyl ions; this suggests a co-localization of ATP or peptides as neurotransmitters. 2) Small granular vesicle-free axons, containing small clear vesicles and large granular vesicles in variable ratio. Most cores of these large granular vesicles were heavily stained with uranyl ions. No storage or uptake of amine into the synaptic vesicles was detected. Some axons appeared to be typically cholinergic, some, typically non-adrenergic, noncholinergic, and the rest, intermediate between the two. All axons stained heavily with reaction products for AChE activity, suggesting their cholinergic nature.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 247 (1987), S. 573-582 
    ISSN: 1432-0878
    Schlagwort(e): Seminal vesicle ; Histology ; Histochemistry ; Electron microscopy ; Physiology ; Clarias gariepinus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The seminal vesicle of the African catfish, Clarias gariepinus, consists of 36–44 fingerlike lobes built up of tubules in which a fluid is secreted containing acid polysaccharides, acid-, neutral- and basic proteins, and phospholipids. In this fluid sperm cells are stored. The seminal vesicle fluid immobilizes the sperm cells. After ejaculation, it prolongs the period of sperm activity. The seminal vesicle fluid is secreted by the epithelium lining the tubules. The tubules in the proximal part of the lobes are predominantly lined by a simple cylindrical and those of the distal part by a simple squamous epithelium. These epithelial cells contain enzymes involved in energy-liberating processes, the enzyme activites being proportional to the height of the cells. Interstitial cells between the tubules have enzyme-histochemical and ultrastructural features indicative of steroid biosynthesis. Similar characteristics are found in testicular interstitial cells. The most rostral seminal vesicle lobes and the most caudal testicular efferent tubules form a network of tubules that opens at the point where the paired parts of the sperm ducts fuse with each other. The tubules of most seminal vesicle lobes, however, form a complex system that fuses with the unpaired part of the sperm duct.
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 248 (1987), S. 709-711 
    ISSN: 1432-0878
    Schlagwort(e): Microtubules ; Terminal web ; Small intestine ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The terminal web (TW) region of mature absorptive cells in the small intestine of the rat contains an elaborate cytoskeleton which supports the apical microvillus membrane. In studies regarding the structural organization of the cytoskeleton and associated proteins in the small intestine, microtubules have not been mentioned as components of the TW. By transmission electron microscopy of conventional resin-embedded sections of rat small intestine, we observe many microtubule profiles in the TW of mature absorptive cells. These microtubules are found in various orientations, although most course parallel to the long axis of the cell, and many microtubule profiles are seen in close association with smooth-surfaced vesicles.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 250 (1987), S. 13-20 
    ISSN: 1432-0878
    Schlagwort(e): Alpha-bungarotoxin ; Autoradiography ; Cholinergic receptors ; Electron microscopy ; Suprachiasmatic nucleus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of (125I) alpha bungarotoxin (α-BTX) binding sites in the suprachiasmatic nucleus (SCN) of the adult female rat was examined by electron-microscopic autoradiography. The ultrastructural distribution of silver grains was analysed by line source, direct point count, and 50% probability circle methods. Real grain distribution was significantly different from that of randomly generated hypothetical grains. Line source analysis demonstrated two populations of sources: one associated with membranes, and one inside neuronal structures. Probability circle analysis of shared grains indicated that membrane-bound-radioactive sources were mainly asssociated with axo-dendritic appositions. Only a small proportion of labeled neuronal interfaces exhibited synaptic differentiations in the plane of section. However, the compartment containing synaptic terminals was the most enriched when comparing real to hypothetical grains. Probability circle analysis of exclusive grains demonstrated that sources that were not associated with neuronal plasma membranes were likely to be within nerve cell bodies and dendrites. It is concluded that the majority of specifically labeled α-BTX binding sites in the SCN is membrane bound, and may be associated with axodendritic synaptic transmission. The presence of a significant proportion of the label in the soma and dendrites of suprachiasmatic neurons 24 h after ventricular infusion suggests that some of the labeled binding sites (junctional or nonjunctional) may be internalized within these two compartments.
    Materialart: Digitale Medien
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  • 45
    ISSN: 1615-6102
    Schlagwort(e): Cytoskeleton ; Contractile proteins ; Lowicryl ; LR White ; Polyvinylalcohol ; Immunogold staining ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Three embedding media have been compared with respect to post-embedding immunolabeling of contractile and cytoskeletal antigens in aldehyde-fixed smooth muscle tissue: the methacrylate derivates lowicryl K4M (cured at −35 or 60°C) and LR White (cured at 0 or 60°C) and the water soluble resin, polyvinylalcohol (dried at 60°C). Measurements of intensity of labeling of ultrathin sections in the fluorescence microscope showed that five antigens (actin, myosin light chain, tropomyosin, filamin and vinculin) reacted more or less equally with their respective antibodies in all the embedding media, including those cured at 60°C. One antibody (anti-light meromyosin) reacted well only with polyvinylalcohol-embedded tissue. In contrast to the relative invariance of antibody reactivity between media clear differences in the preservation of ultrastructural integrity were observed. Embedding in polyvinylalcohol (dried at 60°C) and in Lowicryl (cured at −35°C) resulted in superior preservation as compared to Lowicryl or LR White cured at 60°C. Examples of uitrastructural immunocytochemistry with the antibodies against filamin and myosin light chain, using the immunogold staining procedure are presented: the sites of localization by these antibodies were the same with all the media tried. The relative merits of the different methods are discussed.
    Materialart: Digitale Medien
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  • 46
    ISSN: 1615-6102
    Schlagwort(e): Cytopathology ; Rhabdovirus ; Development ; Electron microscopy ; Cuscuta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Electron microscopic examination ofCuscuta odorata, used for transmission trials, revealed mycoplasma-like organisms (MLO) as well as rhabdovirus-like particles, unknown toCuscuta. The virus infection is confined to certain phloem-parenchyma cells and a 1–2 cell thick layer of parenchyma cells with thickened walls surrounding the central cylinder. Virus particles, mostly bacilliform, could be detected mainly in the nucleus but also in the cytoplasm. They reach a length of 350–400 nm and a diameter of approximately 75 nm. Virus assembly takes place exclusively in the nucleus. Virus maturation occurs in membrane bound areas within the nucleus, which have no connection with the perinuclear space. Formation of nucleocapsids is always associated with a nuclear viroplasm. Envelopment of virus particles occurs in these membrane bound areas. Budding into the perinuclear space does not occur. Virus infection leads to degeneration and finally to death of the protoplast.
    Materialart: Digitale Medien
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Protoplasma 140 (1987), S. 100-109 
    ISSN: 1615-6102
    Schlagwort(e): Actin ; Conifer ; Electron microscopy ; Picea glauca ; Somatic embryo ; Tissue culture ; Ultrastructure ; White spruce
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Somatic embryos in embryogenic callus cultures derived from Immature zygotic embryos ofPicea glauca (White spruce) were examined by light and electron microscopy. Somatic embryos consist of an embryonic region of small densely cytoplasmic cells subtended by a suspensor consisting of long highly vacuolated cells. Mitotic figures are frequent in the embryonic cells but are not observed in the suspensor. Cell divisions in the embryonic region apparently produce rows of cells which elongate to form the suspensor. The presence of abundant polysomes, coated membranes and dictyosomes in the cytoplasm of embryonic and upper suspensor cells suggests rapid growth of the embryo. In contrast the basipetal suspensor cells appear to be senescing. While only a few scattered microfilaments are present in the meristematic cells, the upper suspensor cells contain numerous bundles of longitudinally oriented microfilaments. These bundles correspond to actin cables observed in light microscope preparations stained with rhodamine labelled phalloidin and are oriented parallel to the direction of active streaming in these cells.
    Materialart: Digitale Medien
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Colloid & polymer science 265 (1987), S. 855-859 
    ISSN: 1435-1536
    Schlagwort(e): Electron microscopy ; polyethylenemelt ; fine structure ; artifact
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Abstract There are still two opinions on the fine structure of polymer melts and glasses: (a) that the structure is similarly homogeneous to that in lower molecular weight materials and (b) that the structure shows larger short-range order regions (2–20 nm), which consist of bundeled segments of the chain molecules. Whereas opinion a relies more on indirect methods of investigation, opinion b is based mainly on fine granular structures which become visible in electron microscope investigations of surfaces of glassy solidified polymers. Such a fine structure can now be observed directly in a polyethylene melt. However, the structure is exposed as an artifact, so opinion a is supported.
    Materialart: Digitale Medien
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 244 (1987), S. 180-184 
    ISSN: 1434-4726
    Schlagwort(e): Localized laryngeal amyloidosis ; Light microscopy ; Electron microscopy ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We performed light and electron microscopic studies in a case of localized supraglottic laryngeal amyloidosis involving a 55-year-old woman. Tissue specimens were stained with hematoxylin and eosin, and alkaline Congo red with or without permanganate (KMnO4) treatment, and were also examined with peroxidase-antiperoxidase immunohistochemistry. Biopsy specimens from the epiglottis showed diffuse replacement of the subepithelial region by amyloid, which showed a typical green birefringence under polarized light. Tissue affinity for Congo red was persistent after the KMnO4 treatment. However, the tissue sections showed a positive reaction only to the anti-P component antibody. Electron microscopic studies revealed some disorders of the plasma cells, suggesting that these cells play an important role in focal production of amyloid fibrils.
    Materialart: Digitale Medien
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 244 (1987), S. 30-35 
    ISSN: 1434-4726
    Schlagwort(e): Central venous hemangioma ; Mandible ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To date, 96 cases of central hemangiomas of the jawbones have been described in the literature. Of these cases, the mandible has been more affected than the maxilla, while approximately 50% of all cases occur in the first and second decades of life. Histopathologically, cavernous and capillary types are often found, in contrast to the central venous type, which is rare. We have recently treated a 44-year-old man, who was found to have a central venous hemangioma in his mandible. Immunohistochemical studies were performed using factor-VIIIrelated antigen as well as various lectins as markers for tumor endothelial cells. Our results showed that four kinds of lectins (UEA-I, PNA, ConA, and DBA) were useful for the marker as factor-VIII-related antigen. Scanning electron microscopic findings of this tumor demonstrated that the lumina of the blood vessels were more rough, while the lining endothelial cells were more irregular when compared with those of the normal vascular system.
    Materialart: Digitale Medien
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1987), S. 361-365 
    ISSN: 1434-4726
    Schlagwort(e): Human inner ear ; Congenital anomalies ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We performed light and electron microscopic studies on the temporal bones of a patient with genetic aplastic deafness, in which the right ear had a Mondini-type defect and the left ear a Michel-type anomaly. The round window of each ear was absent. The stapedial foot plate of the right ear was depressed at its central part and was covered by thin membrane. The course of the internal auditory meatus of the left ear was deviated ventrally. There was total aplasia of the cochlea in the left ear, while that of the right ear showed only three-quarters of a turn. In this ear, three sites of spherical bulging were found and were believed to represent outer hair cells. Other structures of the normal cochlear duct were not present. The modiolus of the left ear was round and dome-shaped, contained sparse nerve fibers and a primitive spiral ganglion. The saccule, utricle and semicircular canals of each ear were missing, so that a common cavity of the vestibular system was present. Several otoliths could be seen under the surface of the membrane covering the common cavity. No sensory cells or their related tissues could be found in either ear.
    Materialart: Digitale Medien
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1987), S. 382-386 
    ISSN: 1434-4726
    Schlagwort(e): Experimental tympanosclerosis ; Calcium antagonists ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effect of calcium antagonists in experimental tympanosclerosis following infection with Streptococcus pyogenes and vitamin D3 intoxication has been analyzed in a rat animal model. Compared with untreated animals, calcium antagonists exert a positive effect on the degenerative process and on secondary calcification in the subepithelial layer. This effect could be substantiated planimetrically.
    Materialart: Digitale Medien
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  • 53
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 606-614 
    ISSN: 0570-0833
    Schlagwort(e): Scanning probe microscopy ; Nobel lecture ; Electron microscopy ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 54
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 595-605 
    ISSN: 0570-0833
    Schlagwort(e): Electron microscopy ; Nobel lecture ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
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  • 55
    Digitale Medien
    Digitale Medien
    Hoboken, NJ [u.a.] : Wiley-Blackwell
    Journal of Orthopaedic Research 5 (1987), S. 157-163 
    ISSN: 0736-0266
    Schlagwort(e): Matrix vesicles ; Growth plate ; Electron microscopy ; Life and Medical Sciences
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: We studied the proximal tibial growth plates of 15-day-old mice to determine if matrix vesicle concentration varies among growth plate zones or between the pericellular and territorial matrix compartment and the interterritorial matrix compartment. Growth plates were examined by electron microscopy and divided into five zones: reserve zone (RZ), upper proliferative zone (UPZ), lower proliferative zone (LPZ), upper hypertrophic zone (UHZ), and lower hypertrophic zone (LHZ) which included the calcifying zone. We measured the diameter and volume fraction of matrix vesicles and calculated their numerical density and volume per cell and number per cell in the pericellular and territorial matrix and in the interterritorial matrix of each zone. In the pericellular and territorial matrix compartment, the matrix vesicle concentration progressively decreased from the RZ to the LHZ. Changes in matrix vesicle concentration in the interterritorial matrix followed a different pattern. Between the RZ and the UPZ, matrix vesicle numerical density declined slightly and then increased to peak values in the LPZ and UHZ, followed by a decline between the UHZ and the LHZ. These changes in matrix vesicle concentration paralleled previously reported changes in intramitochondrial calcium content (8), suggesting that matrix vesicle production in growth plate may be related to intracellular calcium concentration. The existence of the maximum concentration of matrix vesicles in the LPZ and UHZ longitudinal septa which do not mineralize followed by a decline in matrix vesicle concentration in the LHZ longitudinal septa which mineralize suggests that a high concentration of matrix vesicles may be needed to prepare the matrix for mineralization or to initiate mineralization and that matrix vesicles are depleted during mineralization.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 56
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 6 (1987), S. 357-366 
    ISSN: 0741-0581
    Schlagwort(e): Electron microscopy ; Immunolabeling ; Skeletal muscle ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Immunoelectron microscopy techniques were used to localize alpha-actinin within the Z lattice of adult skeletal muscles. Analysis of electron micrographs by direct visualization demonstrated that anti-alpha-actinin Fab fragments bound throughout the Z lattice. A low-resolution scanning densitometry technique was developed to quantitate the visual increase in the density of the Z lattice. These techniques did not allow determination of the particular component of the Z lattice, amorphous matrix, axial filaments, or cross-connecting filaments with which the antibody was associated. Therefore, additional techniques, including direct measurement of filament diameters and optical diffraction, were utilized in determining which components of the Z lattice bound anti-alpha-actinin Fab fragments. These analyses suggest that the antibody binding is distributed evenly throughout the lattice, along the filaments, and between them and is confined to the region of double overlap of the ends of the thin filaments.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 57
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 6 (1987), S. 131-141 
    ISSN: 0741-0581
    Schlagwort(e): Skeletal muscle ; Myofibrils ; Fish ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: We have studied the structure of the M band in fish skeletal muscle using thin sectioning and deep-etching rotary shadowing. A reconstruction of the M band from these images shows it to be formed by obliquely arranged struts, which join the thick filaments to each other. Thickening of the thick filaments' profiles and nodal points where the struts cross each other are responsible for the fine sublines visible in longitudinal sections of the M band region.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 58
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 6 (1987), S. 255-301 
    ISSN: 0741-0581
    Schlagwort(e): Fixation ; Processing ; Electron microscopy ; Human biopsies ; Diagnosis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Transmission electron microscopy serves a useful and often diagnostic purpose in the analysis of human disease. The emerging discipline of ultrastructural pathology serves a much wider field than that of kidney pathology and, of necessity, requires two essential elements. These are (1) the interpretive knowledge which covers all cells in all tissues which compose all organs, their normal substructural composition, and the ultrastructural expression of all of the basic mechanisms of the pathobiology of human disease, and (2) technically excellent preparations of these varied specimens.In this review, we emphasize the technical aspects necessary for the preparation of these specimens. These include the handling of varied specimens from the time of interruption of blood flow to the sample until fixation, fixation methodology, and routine processing methods for electron microscopy. Specialized techniques that are readily accomplished in an ultrastructural pathology service laboratory are also described. These include methods for the demonstration of glycogen, peroxidase(s), the glycocalyx. We also describe the preparation of permanent, alkaline Giemsa-stained 1-μm plastic sections for light microscopic diagnosis, the use of an agar-pelleting technique to change cell suspensions into readily handled blocks, and the use of Spurr's (J. Ultrastruct. Res. 26:31, 1969) low viscosity embedding for all skin and heavily collagenized specimens.The diagnostic report for individual samples can routinely be available within 24 hours of specimen arrival in the ultrastructural pathology laboratory with the methods we review here. Examples of these varied samples of human tissues and cells and methods for preparing them are illustrated. We have found such methods useful for diagnostic purposes, e.g., to identify the site of origin of a brain metastasis as the alveolar cell (type II pneumocyte) of the lung, based on the presence of typical lamellar (surfactant) bodies in the metastatic tumor cells (Dvorak and Monahan-Earley: Norelco Reporter 32:29-36, 1985c), as well as to describe for the first time a new tumor, such as the gut autonomic nerve (GAN) tumor (Walker and Dvorak: Arch. Pathol. Lab. Med. 110:309-316, 1986) or a cell injury process, axonal necrosis, to be characteristic of Crohn's disease (Dvorak et al.: Hum. Pathol. 11:620-634, 1980d; Dvorak and Silen: Ann. Surg. 201:53-63, 1985).
    Zusätzliches Material: 49 Ill.
    Materialart: Digitale Medien
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  • 59
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 7 (1987), S. 277-282 
    ISSN: 0741-0581
    Schlagwort(e): Electron microscopy ; Electron diffraction ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: New findings on quasicrystals with icosahedral, octagonal, decagonal, and dodecagonal symmetries obtained recently in the Beijing Laboratory of Electron Microscopy, Chinese Academy of Sciences, are presented. Special emphasis is put on the relation between quasicrystalline and crystalline structures. The important role played by electron diffraction and high-resolution electron microscopy in revealing these quasiperiodic structures is pointed out.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 60
    Digitale Medien
    Digitale Medien
    Hoboken, NJ [u.a.] : Wiley-Blackwell
    Journal of Orthopaedic Research 5 (1987), S. 128-132 
    ISSN: 0736-0266
    Schlagwort(e): Growth plate ; Protease ; Proteoglycan ; Electron microscopy ; Life and Medical Sciences
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: To assess the effect of intracellular growth plate chondrocyte enzymes on proteoglycan structure, we examined enzyme-treated articular cartilage proteoglycans and untreated articular cartilage proteoglycans with the electron microscopic monolayer technique. The untreated proteoglycan monomers ranged in length from less than 20 nm to more than 700 nm, with a mean length of 224.5 + 101.6 nm in one experiment and 224.6 + 95.7 nm in a second experiment. Incubation with growth plate enzymes reduced proteoglycan monomers to fragments with lengths that varied from less than 5 nm to 143 nm, increased the variability in monomer length, and destroyed proteoglycan aggregates. The enzyme treated monomers had an average length of 29.5 + 17.9 nm in one experiment and 35.2 + 17.0 nm in a second experiment. The smallest common fragments were 15 nm long and would be expected to contain about 15 glycosaminoglycan chains. This experiment demonstrates that enzymes extracted from growth plate chondrocytes can degrade the chondroitin sulfate-rich region of proteoglycan monomer core proteins, produce a range of monomer fragment sizes with less than 20% of the fragments shorter than 5 nm or longer than 100 nm, increase the variability in monomer length, and degrade proteoglycan aggregates.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 61
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 6 (1987), S. 81-85 
    ISSN: 0741-0581
    Schlagwort(e): Ultramicrotomy ; Thin sectioning ; Microtome knives ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Low-angle chromium metal shadowing was used to compare the surface roughness of ultrathin sections cut with diamond, sapphire, and glass knives. Surface roughness was less on diamond-cut and sapphire-cut sections than on glass-cut sections, and was greater over tissue than resin, and greatest over red blood cells and mitochondria. Surface roughness contributed to image density variation and thereby lowered contrast and informational content of the sectioned tissue.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 62
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 5 (1987), S. 59-63 
    ISSN: 0741-0581
    Schlagwort(e): Electron microscopy ; Postsection staining ; Section contamination ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: A method is described for eliminating a form of contamination called embedding pepper that appears in, or on, thin sections following poststaining in lead citrate. The pepper is present most often in the matrixes of mitochondria, peroxisomes, and red blood cells. Formation of pepper can be prevented by treating the section with 0.5 N HCl or 1.0% ethylenediaminete-traacetic acid (EDTA) for 1-5 min before staining in uranyl acetate or lead citrate.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 63
    ISSN: 0741-0581
    Schlagwort(e): Immunocytochemistry ; Electron microscopy ; Colloidal gold ; Glial fibrillary acidic protein ; Neuron-specific enolase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: A postembedding immunocytochemical technique is described that allows ultrastructural localization of glial fibrillary acidic protein and neuron-specific enolase on tissues originally processed only for routine light and electron microscopy. Use of the oxidizing agent sodium metaperiodate prior to incubation with the primary antiserum sufficiently removes osmium tetroxide (OsO4) from potential antigen - antibody combining sites to allow specific localization of these neural antigens by colloidal gold immunolabelling. Both human and monkey neural tissues, prepared for routine ultrastructural examination with aldehyde fixatives and OsO4 postfixation, show excellent ultrastructural morphology and antigen localization. In addition, formalin-fixed, paraffin-embedded pathological human brain tissues, obtained at autopsy up to 22 years previously, show good ultrastructural immunolocalization of glial fibrillary acidic protein when re-embedded for electron microscopy. Thus, ultrastructural immunolocalization of certain neural antigens is easily achieved in tissues originally processed for routine light and electron microscopy. This allows re-examination of archival tissues using current immunocy-tochemical advances, including that of selected pathological tissues previously prepared solely for light microscopy.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 64
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 7 (1987), S. 191-193 
    ISSN: 0741-0581
    Schlagwort(e): Morphometry ; Computer program ; Electron microscopy ; Stereology ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: We describe a short computer program, which is written in Pascal language, to measure the diameter of circular and elliptical profiles in sections. Coordinate pairs on the microscope stage, corresponding to two or three points of a profile, are input to obtain its diameter. The program enables one to take measurements directly on the microscope, thereby reducing photographic work and caliper measurement. While the program is largely designed for electron microscopy, it also may be useful for light microscopy morphometry.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 65
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 7 (1987), S. 301-312 
    ISSN: 0741-0581
    Schlagwort(e): Electron microscopy ; Nanostructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Nanostructural features in some ceramics have been discussed and reviewed. Based on our research results and recent published investigations, many topics, such as grain, grain boundary, interface film, grain boundary engineering, microcrack, microdomain, nanodomain, domain boundary, and phase transformation, etc., have been dealt with; and many materials, such as Si3N4, β″-Al2O3, MgO, SiC, (Hg, Cd) Te, BNN, ZrO2, PLZT, CdSe, Ca10(PO4)6, (OH)2, etc., have been involved. The results are important to understand the relation between the structure and property of materials and to improve the materials' technology.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
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  • 66
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 5 (1987), S. 131-140 
    ISSN: 0741-0581
    Schlagwort(e): Electron microscopy ; Sample preparation ; Petrographic thin sections ; Adhesive removal ; Oxygen plasma etching ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Thin-sectioned samples mounted on glass slides with common petrographic epoxies cannot be easily removed (for subsequent ion-milling) by standard methods such as heating or dissolution in solvents. A method for the removal of such samples using a radio frequency (RF) generated oxygen plasma has been investigated for a number of typical petrographic and ceramic thin sections. Sample integrity and thickness were critical factors that determined the etching rate of adhesive and the survivability of the sample. Several tests were performed on a variety of materials in order to estimate possible heating or oxidation damage from the plasma. Temperatures in the plasma chamber remained below 138°C and weight changes in mineral powders etched for 76 hr were less than ±4%. A crystal of optical grade calcite showed no apparent surface damage after 48 hr of etching. Any damage from the oxygen plasma is apparently confined to the surface of the sample, and is removed during the ion-milling stage of transmission electron microscopy (TEM) sample preparation.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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