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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Diseases of the colon & rectum 33 (1990), S. 773-777 
    ISSN: 1530-0358
    Schlagwort(e): Giant inflammatory polyp ; Idiopathic inflammatory bowel disease ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Five cases of giant inflammatory polyps associated with idiopathic inflammatory bowel disease are reported. Polyps produced intestinal obstruction in three cases; consequently, surgery was performed. In a further two cases, intestinal bleeding was improved by endoscopic polypectomy. Electron microscopy showed fibroblasts, myofibroblasts, mast cells, lymphocytes, collagen fibers, capillaries, and venules. Remnants of the original mucosal epithelial cells, smooth muscle cells, and hypertrophic autonomous nerve plexuses were noted. Nerve fibers were interwoven with the matrix of the polyps. Mast cells were closely linked with vessels, nerves, and collagen fibers. They may have an important role in the excessive granulation, angiogenesis, and fibrotic process in giant inflammatory polyps.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Rheumatology international 10 (1990), S. 103-106 
    ISSN: 1437-160X
    Schlagwort(e): Synovium ; Synoviocytes ; Monoclonal antibody ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The functionally important lining cells of the synovium (types A and B synoviocytes) are the subjects of much study but have presented problems with their characterization and microscopical identification, particularly at the light level. Type A (macrophage-like) synoviocytes, however are more easily localized than the type B (fibroblast-like) variety because of the greater availability of antimacrophage antisera. We describe, using light and electron microscopy, a monoclonal antibody which in the synovial intimal layer is specific for type B synoviocytes.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 416 (1990), S. 237-248 
    ISSN: 1432-2307
    Schlagwort(e): Neurilemoma ; Pseudosarcoma ; Electron microscopy ; Immunohistochemistry ; Cytogenetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A series of 29 cellular schwannomas is described in terms of their clinical presentation and course, light and electron-microscopic appearance, immunohistochemical properties and cytogenetics. The study indicates that cellular schwannoma can be defined as a subtype of classical schwannoma, characterized by spindle cells forming a compact fascicular, sometimes fibrosarcoma-like growth pattern, a low mitotic activity, a generally moderate nuclear and cellular polymorphism and a high degree of Schwann cell differentiation as seen by electron microscopy and immunohistochemistry. The tumour is characteristically located close to the vertebral column, in the mediastinum or retroperitoneum and has a benign course. Occasionally bone destruction and neurological symptoms develop. The clinical appearance together with the high cellularity, fascicular pattern and mitotic activity had led to the erroneous diagnosis of a soft tissue sarcoma in a few cases, and cellular schwannoma may thus be considered to be a pseudosarcoma. Immunohistochemically, cellular schwannomas appear to deviate from classical schwannomas and malignant peripheral nerve sheath tumours by their expression of glial fibrillary acidic protein. The chromosome analysis revealed a normal diploid stemline karyotype, with a variety of abnormal clones, including one with monosomy 22.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 417 (1990), S. 261-266 
    ISSN: 1432-2307
    Schlagwort(e): Stomach ; Paraganglioma ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We report the second case of a malignant paraganglioma of the stomach in a 56-year-old female patient. However, our case is the first investigated by immunohistochemistry and electron-microscopy. The tumour was characterized immunohistochemically by the presence of neurofilament protein, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, chromogranin A, ACTH, leu-enkephalin and vasoactive intestinal polypeptide, and ultrastructurally by demonstration of neurosecretory granules and paranuclear intermediate filament whorls. Despite massive metastatic spread in the abdominal cavity, the patient is still alive 4 years after initial diagnosis.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-2307
    Schlagwort(e): Mouse ; Nephrotic syndrome ; Hereditary nephritis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Glomerular lesions in hereditary nephrotic mice (ICGN strain) were investigated by electron microscopy. The glomeruli of unaffected animals, which appeared normal by light microscopy, had developed an ultrastructural change in the glomerular capillary basement membrane (GCBM). There was a partial thickening of the GCBM with bilaminar splitting of the lamina densa and an electron-dense fibrillar material exhibiting cross-striations. In affected animals, light microscopy revealed a marked thickening of GCBM and an increase of mesangial matrix without cellular proliferaton. By electron microscopy, multilaminar splitting of the lamina densa in the thickened GCBMs and fusion of the epithelial foot processes were observed. In some severely affected animals, immune complex deposition was found in GCBM, but little if any was observed in other animals. In the end, the glomeruli were globally sclerosed. Our findings suggest that initial structural abnormalities in GCBM may play an important role in the onset and development of the disease, though subsequent events such as immune complex deposition would modify the disease.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-2307
    Schlagwort(e): Cyclosporin A ; Human skin xenografts ; Histology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cyclosporin A (CsA) is a potent immunosuppressant with a selective activity on T-helper lymphocytes. However, CsA also exerts biological effects on non-lymphoid cells (fibroblasts, endothelial and epithelial cells). CsA can inhibit in vivo and in vitro DNA synthesis of epidermal keratinocytes (EK) and induces in vivo morphological alterations of kidney epithelial cells. In the present study we investigated the in vivo effects of a short-term CsA treatment (50 mg/kg per day) on DNA synthesis (evaluated through 5-bromo-2′-deoxyuridine incorporation) and on the histological features of normal human skin xenografted (NHSX) on to congenitally athymic nude mice. When compared with control NHSX, CsA induced a statistically significant inhibition of DNA synthesis of NHSX EK. At the light- and electron-microscopic level, apart from a decrease in the thickness of the viable epidermis of NHSX (statistically non-significant), no noticeable differences between treated and control NHSX could be detected. EK, Langerhans cells and melanocytes appeared morphologically unaffected by CsA and no signs of acute toxicity (giant mitochondria, vacuolization, microcalcifications) were seen. These results suggest that CsA exerts a subtle effect on human EK; indeed, despite an unequivocal antiproliferative activity, no significant histological changes related to the acute CsA toxicity seem to be induced on the various epidermal cell types.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-2307
    Schlagwort(e): Salivary gland ; Neoplasm ; Mucoepidermoid carcinoma ; Electron microscopy ; Histogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Current classifications of salivary gland tumors separate mucoepidermoid carcinoma from other neoplasms on the basis of a number of histological features, in particular the lack of participation of neoplastic myoepithelial cells. However, ultrastructural examination of low- and intermediate-grade mucoepidermoid carcinomas and pleomorphic adenomas reveals many common organizational and cellular features. Of prime importance is the relationship of intermediate cells to the luminal cells in mucoepidermoid carcinomas, which is remarkably similar to that seen between modified myoepithelial cells and luminal cells in pleomorphic adenomas. The results suggest that intermediate cells of mucoepidermoid carcinoma are the counterpart of the modified myoepithelial cells of pleomorphic adenoma. The generally accepted hypothesis that the former tumor develops from an excretory duct reserve cell, while the latter originates from an intercalated duct stem cell does not seem to be valid; pleomorphic adenoma and mucoepidermoid carcinoma appear to be closely related morphologically.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1432-2307
    Schlagwort(e): Atubular glomeruli ; Chronic nephropathy ; Electron microscopy ; Lithium ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The very heterogeneous population of glomeruli in rats with lithium-induced chronic nephropathy which includes small glomeruli without connection to a proximal tubule (atubular glomeruli) and large hypertropic glomeruli with connection to a normal proximal tubule, was studied at the ultrastructural level, using stereological methods. After 8 weeks of lithium treatment followed by 8 weeks without lithium the hypertrophic glomeruli showed no changes in their relative ultrastructural composition, including normal mesangium, basement membrane-like material and peripheral basement membrane. The absolute quantities of each component were, however, increased due to the increased volume of the glomeruli. The atubular glomeruli had increased volume fractions of mesangium, peripheral basement membrane, basement membrane-like material and epithelium, whereas the absolute quantities were decreased due to the decreased volume. The thickness of the basement membrane was within normal limits in the group of hypertrophic glomeruli but increased by 31% above controls in the group of atubular glomeruli. Both groups of glomeruli in lithium-treated animals showed normal mean foot process width, but with a slightly abnormal distribution. The atubular glomeruli showed a disproportionate large decrease in peripheral filtration surface and capillary length, compared with the reduction in glomerular volume, whereas the hypertrophic glomeruli showed changes in proportion with the increased volume.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-0568
    Schlagwort(e): Neuropeptide Y ; Substance P ; Immunocytochemistry ; C-fibers ; Dura mater ; Dural sinus ; Meningeal arteries ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Density and pattern of nerve fibers with neuropeptide Y-like immunoreactivity (NPY-LI) and substance P-like immunoreactivity (SP-LI) in the rat dura mater encephali were investigated by light and electron microscopy using whole-mount preparations. NPY-LI fibers are observed throughout the encephalic dura mater. A remarkable net of NPY-LI nerve fibers is located in the walls of the sagittal and transverse sinuses. Beyond that NPY-LI network, distinct NPY-LI nerve fibers or plexus occur in the rostral falx, parietal dura mater of the olfactory bulb, supratentorial dura mater, parietal dura mater of the cerebellum, tentorium cerebelli and the ventral dura mater. Electron microscopic studies reveal that NPY-LI is exclusively located in unmyelinated axons of small and large nerve fiber bundles, with or without a perineural sheath. Immunopositive C-fibers are predominantly associated with the vascular bed. SP-LI nerve fibers have a moderate and more uniform distribution in the encephalic dura mater. A distinct plexus of SP-LI fibers follows the branches of the middle meningeal artery and the adjacent dura mater. SP-LI fibers are most prominent in the parietal dura mater of the cerebellum. Fine beaded SP-LI fibers, arising from larger SP-LI fiber bundles, are observed in close association to the capillary bed. SP-LI axons are all unmyelinated. They are found in larger nerve fiber bundles with a perineural sheath or in Schwann cells lacking any perineural sheath. The function of NPY-LI and SP-LI nerve fibers in the rat dura mater is discussed in relation to their topography, density and termination.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 79 (1990), S. 387-394 
    ISSN: 1432-0533
    Schlagwort(e): Triosephophosphate isomerase (TPI) ; Mitochondrial myopathy ; Muscle tissue ; Electron microscopy ; Enzyme histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Morphological changes are shown in the muscle biopsy specimens of an 8-year-old girl who suffered from a triosephosphate isomerase (TPI) deficiency, resulting in a chronic, nonspherocytic, hemolytic anemia, mental retardation and neuromuscular impairment. The newly introduced enzyme histochemical reaction for TPI demonstrated a total lack of histochemically detectable enzyme activity, whereas biochemical analysis of muscle tissue revealed less than 10% of the normal enzyme activity. Electron microscopy showed a degenerative myopathy with an increase in the amount of intracellular glycogen. Additionally, mitochondrial changes within the muscle fibers were observed to be similar to those in mitochondrial myopathies. The disturbed balance between glycerinaldehyde phosphate and dihydroxy-acetone phosphate, due to the deficiency of the TPI enzyme, is interpreted as the biochemical background of an impaired electron transport across the mitochondrial membrane, resulting in the coexistence of an impaired glycolytic pathway and an impaired mitochondrial metabolism of muscle cells.
    Materialart: Digitale Medien
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 80 (1990), S. 123-128 
    ISSN: 1432-0533
    Schlagwort(e): Marinesco-Sjögren syndrome ; Muscle biopsy ; Electron microscopy ; Autophagocytosis ; Double-membrane structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Seven muscle biopsies from patients with the clinical characteristics of Marinesco-Sjögren syndrome (MSS) revealed myopathic changes of two types; muscle fiber necrosis followed by regeneration and focal myofibrillar degeneration inducing autophagocytosis with rimmed vacuole formation. In two young patients, massive muscle fiber necrosis with phagocytic invasion was the predominant feature and autophagic phenomenon was minimal, resembling the findings in progressive muscular dystrophy. Myofibrillar degeneration with autophagic phenomenon was prominent in five adult patients. The coexistence of these two degenerative processes and the secondarily induced reactive changes of muscle fiber hypertrophy, interstitial fibrosis, occasional ragged-red fibers and type 1 fiber predominance, are responsible for the wide spectrum of muscle pathology in MSS. The dense double-membrane structure surrounding myonuclei, previously reported as being specific to MSS, was present in only one biopsy.
    Materialart: Digitale Medien
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  • 12
    ISSN: 1432-0533
    Schlagwort(e): Global ischemia ; Cerebellum ; Hippocampus ; Electron microscopy ; Synapse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have developed a functional vegetative model by an 18-min clamping of the ascending aorta combined with a bypass formation between the aorta to right atrium and the aorta to femoral vein. Complete global brain ischemia (CGBI) induced for 18 min with this model provided the following distinct advantages: cardiopulmonary functions were well preserved during postischemic recirculation, and all dogs survived without serious extracerebral complications. Neuronal damage in vegetative dog induced by an 18-min CGBI was studied by light and electron microscopy. The Purkinje cells and the hippocampal CA1 pyramidal cells showing clumping of nuclear chromatin and slightly increased stainability were observed after CGBI without recirculation. All these neurons showed transient increased stainability with microvacuolation 15 min after recirculation. Over 50% of these neurons showed virtually normal features 1 h after recirculation. Damage to these neurons progressed again slowly up to 6 h after recirculation. However, all these neurons had disintegrated 2–3 days after recirculation. A decrease in synaptic vesicles was observed in many presynaptic terminals in the molecular layers of the cerebellum after CGBI without recirculation. These changes in the presynaptic terminals progressed 15 min after recirculation. These results indicated that the damage to the Purkinje cells and the CA1 pyramidal cells induced by CGBI consisted of two phases, and that the change in the early phase was reversible. We speculate that the damage to the Purkinje cells in the early stage is related to the decrease of the synaptic vesicles in the presynaptic terminals.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 81 (1990), S. 162-177 
    ISSN: 1432-0533
    Schlagwort(e): Infusion edema ; Immunocytochemistry ; Clearance ; Electron microscopy ; Brain edema
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The pathways and mechanisms by which edematous fluid accumulation in the extracellular space (ECS) clears from brain are poorly understood. The objective of this study was to explore, using immunocytochemical technique, the fate of a proteinaceous fluid added to the brain ECS and to study the clearance pathways. The protein movement of this edema fluid was investigated using the direct infusion model on rats. Rat albumin (20 μl) was slowly infused into the caudate-putamen of anesthetized adult rats and the spread and clearance of the edema was followed in various brain regions using immunocytochemical and conventional light and electron microscopy at 0, 1, 2, 3, 4, 6, and 8 days post-infusion. Our studies showed that protein-rich edema fluid cleared slowly from the brain, with 8 days required for the infusion albumin to exit completely from the brain parenchyma. Immediately following infusion, the albumin was distributed in the ECS of the white matter and the overlying deep cortical layers related to the infusion site. During the next 24 h, more of the infused albumin traveled through the ECS to the cortical surface where the albumin passed through the glia limitans to reach the subarachnoid front. Additionally, at 48 h post-infusion, that albumin, which had migrated to the ventricular wall, cleared from the ECS of the subependymal white matter and the ependymal clefts to reach the ventricular cerebrospinal fluid (CSF). In edematous regions, the perivascular spaces of venules and veins were filled with reaction product. Continuity of this perivascular reaction product existed from the deep edematous area to the temporobasal subarachnoid space from where the reaction product gradually disappeared from the parenchyma. From these studies we infer that during the late state of the resolution process the edema front moves toward both the ventricle and the cortical surface to reach the CSF. Thus, among the potential routes for edema clearance, the pathways leading to CSF clearance of fluid predominated. During this clearance process, neither neurons, glia nor the vascular endothelium showed any endocytotic response to the infused albumin throughout the 8-day course. We conclude from these observations that the CSF pathway is the major route of protein-rich edema clearance, when such clearance is not complicated by any concomitant CNS perturbation.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 182 (1990), S. 539-545 
    ISSN: 1432-0568
    Schlagwort(e): Corticotrophs ; Pituitary gland ; Golden hamster ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of corticotrophs in the pituitary of golden hamsters was studied by immunocytochemistry. Corticotrophs were classified into three types according to the different size of the secretory granules. Type A and B cells were oval or polygonal in shape containing small (158±38 nm) and medium-sized (250±53 nm) secretory granules, respectively. Type C cells were usually pyramidal or irregular in shape, and contained large secretory granules (380±78 nm). The cytoplasmic organelles of type B and C cells were fairly well developed. In all types of corticotrophs, the secretory granules varied in electron density, and were either arranged in a single row along the cell membrane, or concentrated in the vascular pole of the cytoplasm. Many of the corticotrophs sent processes to encircle neighboring somatotrophs. In the female, the proportions of type A and B cells were higher then those in the male, whereas that of the type C cells was lower. All three types of corticotrophs were observed in the early postnatal stage. The population of type A cells decreased with the advancement of postnatal development, with a concomitant increase of that of the type C cells. Thus, type A cells might represent the immature type of corticotrophs which would evolve to become the type C cells. One to 2 weeks after adrenalectomy, the number of type C cells was drastically increased. This was accompanied by their prominent changes in ultrastructure as in the type B cells. The cytoplasm became hypertrophic with extensive dilated cisternae of rough endoplasmic reticulum. The large Golgi apparatus displayed profiles seemingly involved in the formation of secretory granules. The number of type A cells was moderately decreased, and they showed little morphological alteration. Since type B and C corticotrophs exhibited a remarkable response to adrenalectomy, it is concluded that they represent the active state of corticotrophs.
    Materialart: Digitale Medien
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 79 (1990), S. 473-479 
    ISSN: 1432-0533
    Schlagwort(e): Central neurocytoma ; Neuronal differentiation ; Glial differentiation ; Synaptophysin ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Central neurocytoma has been characterised by its intraventricular localisation, predominant occurrence in young adults, oligodendroglioma-like histology, benign course and ultrastructural evidence for neuronal differentiation. Eleven intraventricular central neurocytomas were studied histopathologically, employing cell type-specific immunocytochemical markers and electron microscopic analysis. In the past, these lesions have caused diagnostic problems since central neurocytomas share basic histopathological features with other periventricular neoplasms. Accordingly, several tumours of this series had previously been classified as ependymomas of the foramen of Monro or oligodendrogliomas. Although generally regarded as benign lesions, two central neurocytomas of this series showed histopathological evidence of anaplasia, with focal necrosis, mitotic activity and vascular proliferation. All central neurocytomas exhibited immunoreactivity for neuronspecific enolase and synaptophysin, indicating consistent neuronal differentiation. Three tumours were studied by electron microscopy and contained synaptic vesicles, neuritic processes and neurosecretory granules. In addition, one tumour contained ganglioid cells and this was associated with focal immunoreactivity for neurofilament protein, suggesting that some central neurocytomas may, at least focally, continue to differentiate towards the formation of mature neurons. Two of the tumours expressed glial fibrillary acidic protein in a considerable percentage of neoplastic cells which demonstrates a capacity for bipotential, i.e. glial and neuronal differentiation. We conclude that the central neurocytoma can be reliably diagnosed using antibodies to neuron-specific enolase and synaptophysin, and that histogenetically, this neoplasm is derived from a neuroectodermal precursor cell capable of both, neuronal and glial differentiation. The hypothesis is proposed that the central neurocytoma originates from the subependymal plate of the lateral ventricles, an embryonal matrix cell layer which postnatally maintains a limited proliferative potential.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 81 (1990), S. 228-232 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral tumor ; Polar spongioblastoma ; Astrocytoma ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case is reported of a 9-year-old boy with a cerebral polar spongioblastoma. This neoplasm, first described by Russell and Cairns in 1947, is morphologically a distinct entity characterized by bipolar tumor cells with palisading nuclei. In the case under study immunoreactivity for neuron-specific enolase was found and ultrastructural features of developing neuronal elements were present. A neuro-endocrine nature was suggested by de Chadarévian et al. (1984) in a morphologically similar case. These findings are in contrast with the longheld view that the polar spongioblastoma is cytogenetically related to the embryonal radial glial cells.
    Materialart: Digitale Medien
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  • 17
    ISSN: 1432-0533
    Schlagwort(e): Creutzfeldt-Jakob disease ; Electron microscopy ; Scrapie ; Tubulovesicular structures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have consistently observed tubulovesicular structures in brain tissues during the terminal stages of naturally occurring and experimentally induced spongiform encephalopathies, irrespective of the host species and virus strain. In NIH Swiss mice inoculated intracerebrally or intraocularly with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus, tubulovesicular structures, measuring 20–50 nm in diameter, were particularly prominent in dilated, pre-and postsynaptic neuronal processes, occasionally being mixed with synaptic vesicles. These structures appeared 13 weeks following intracerebral inoculation, 5 weeks before the onset of clinical signs, when spongiform changes were also detected. The number and density of tubulovesicular structures increased steadily during the course of clinical disease, and were particularly abundant in mice 47 to 51 weeks after intraocular inoculation. In hamsters infected with the 263 K strain of scrapie virus, these structures were initially detected 3 weeks following intracerebral inoculation and increased dramatically at 10 weeks postinoculation. The appearance of tubulovesicular structures before the onset of overt disease in mice inoculated with CJD virus by either the intracerebral or intraocular route, and before the appearance of other neuropathological changes in hamsters infected with scrapie virus, indicate that they represent either a part or aggregate of the infectious virus or a pathological product of the infection.
    Materialart: Digitale Medien
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  • 18
    ISSN: 1432-0533
    Schlagwort(e): Brain cell culture ; Canine distemper virus ; Cerebroside sulfotransferase ; Electron microscopy ; Oligodendrocytes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To study the pathomechanism of demyelination in canine distemper (CD), dog brain cell cultures were infected with virulent A75/17-CD virus (CDV) and examined ultrastructurally. Special attention was paid to the oligodendrocytes, which were specifically immunolabelled. In addition, cerebroside sulfotransferase (CST), an enzyme specific for oligodendrocyte activity was assayed during the course of the infection. Infection and maturation as well as CDV-induced changes were found in astrocytes and brain macrophages. Infection of oligodendrocytes was rarely seen, although CST activity of the culture markedly decreased and vacuolar degeneration of these cells occurred, resulting in their complete disappearance. We concluded that the degeneration of oligodendrocytes and demyelination is not due to direct virus-oligodendrocyte interaction, but due to CDV-induced events in other glial cells.
    Materialart: Digitale Medien
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  • 19
    ISSN: 1432-0533
    Schlagwort(e): Composite ganglioneuroblastoma ; Electron microscopy ; Cerebrum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An unusual cerebral tumor is reported in a 14-year-old boy. On light and electron microscopy, the constituent cells were very complex; the majority of the neoplastic cells were primitive neuroectodermal cells dispersed in myxomatous or fibrous stroma. Neoplastic neuronal cells and hypertrophic astrocytes were also observed in these areas. The neuronal cells showed a continuous spectrum of differentiation from very primitive to mature ganglion cells. Furthermore, the tumor contained a highly cellular discrete area consisting of neuroblasts and their precursor cells. From these findings, a diagnosis of composite ganglioneuroblastoma was made.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 80 (1990), S. 103-107 
    ISSN: 1432-0533
    Schlagwort(e): Brain neoplasms ; Medulloepithelioma ; Primitive neuro-ectodermal tumor ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case is reported of a boy, 3 years of age, with a large medulloepithelioma in the left cerebral hemisphere. Medulloepitheliomas are rare tumors of the primitive medullar epithelium. Histological, immunohistochemical and electron microscopical findings are presented. We discuss previously reported cases, the ontogeny of this type of tumor and the relation to the socalled primitive neuro-ectodermal tumors (PNET).
    Materialart: Digitale Medien
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 80 (1990), S. 671-679 
    ISSN: 1432-0533
    Schlagwort(e): Peroneal muscular atrophy ; Rigidity and tremor ; Autopsy ; Morphometry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An autopsy case of hereditary peroneal muscular atrophy (PMA) with rigidity and static tremor is presented. The patient developed slowly progressive distal muscular atrophy of the legs at the age of 15 years. By the age of 52 years, PMA became marked associated with pes cavus, and tremor and rigidity of the extremities were noted. Motor and sensory conduction velocities gradually depressed and lost near the end of his life. At autopsy, the major neuropathological abnormalities involved the peripheral nervous systems, and were characterized by axonal atrophy and loss of myelinated fibres. These changes involved both the proximal and distal nerves, being more severely affected in the distal. The pathological changes in other regions of the nervous systems were mainly confined to the spinal cord, dorsal ganglia and spinal nerve roots, and pigmented neurons in the brain stem. Morphometrically, the total fascicular area was much smaller than in control, but the total number of myelinated fibers greatly outnumbered that of control 75 200 to 48 200 at the proximal sciatic nerve and then gradually decreased towards the periphery; however, even in the distal sural nerve, the total number of myelinated fibers exceeded that of control (6820 to 5469). Thus, the density of myelinated fibers were much higher, being 1.5 to 2 times greater, than in control. Its abrupt decline at the distal nerve might account for neurogenic atrophy of the distal musculature. Unmyelinated fibers were slightly increased in density and not atrophic. This case is unique in its clinicopathology and does not belong to any subtypes of PMA including “neuronal plus”.
    Materialart: Digitale Medien
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  • 22
    ISSN: 1432-0533
    Schlagwort(e): HTLV-I-associated myelopathy ; Spinal cord lesion ; Electron microscopy ; Primary demyelination ; Remyelination by oligodendrocytes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We describe postmortem findings in a patient with human T lymphotropic virus type I (HTLV-I)-as-sociated myelopathy (HAM). The patient developed the disease 8 years after blood transfusion and showed good response to corticosteroid treatment but died of cardiac failure. Histologically, chronic, mild meningoence-phalomyelitis was noted predominantly involving the bilateral lateral and anterior columns of the middle to lower thoracic segments. The spinal cord lesions showed obvious loss of myelinated nerve fibers and fibrillary gliosis with minimal inflammatory cell infiltration. Electron microscopy of the lesion revealed disintegration of the myelin sheaths, regular separation of the minor dense line of the myelin sheaths, and completely demyelinated axons. In addition, remyelinated fibers with thin central myelin sheaths and disproportionately large axons were seen frequently. These findings indicate that primary demyelination and remyelination by oligodendrocytes occur in the spinal cord lesions of HAM.
    Materialart: Digitale Medien
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  • 23
    ISSN: 1432-0568
    Schlagwort(e): In vitro culture ; Electron microscopy ; Fluorography ; Blastocyst ; Rabbit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Day-6 rabbit blastocysts were cultured in Ham's F10 medium supplemented with polyvinylpyrrolidone as a macromolecular component, for 4 to 12 h. The integrity of the blastocyst cells was demonstrated by electron microscopy. Expansion and biosynthesis of proteins and of DNA were studied after culturing in the presence of 35S-methionine and 3H-thymidine. Polyvinylpyrrolidone did not interfere with the subsequent protein analysis, which was performed by two dimensional gel electrophoresis followed by silver staining and fluorography. More than 600 labelled proteins were found in the blastocyst tissue, many of them were also present in the blastocyst fluid and in the blastocyst coverings. Several proteins seemed to be produced for incorporation into the blastocyst coverings; others, only detected in the culture medium, might have been synthesized for secretion into the environment.
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 182 (1990), S. 481-486 
    ISSN: 1432-0568
    Schlagwort(e): Immunocytochemistry ; Electron microscopy ; CR3 receptors ; Amoeboid microglia ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The present study described the labelling of amoeboid microglial cells in the postnatal rat brain with OX-42, an antibody that recognizes type 3 complement receptors CR3 in mononuclear phagocytes. Of the diverse morphological forms of amoeboid microglia present in the corpus callosum in early postnatal (2–5 days) rats, cells with a round regular outline, or showing short stout processes, were the most intensely stained. When traced from the main cell colony into the borderline zone with the cortex, the immunoreactivity of amoeboid microglia that assumed a ramified form was drastically reduced. Examination of materials from the late postnatal (8–12 days) age group showed that the majority of the OX-42 positive cells in the corpus callosum became oval, elongated and ramified. Immunoelectron microscopy confirmed the above observations, and also showed that the immunoreactivity in the round amoeboid microglia was localized in their plasma membrane, surface projections and invaginations, as well as in some of the subsurface vacuoles. The immunoreactivity was reduced in the oval cells, and diminished in the elongated or ramified form. It is proposed that the presence of CR3 membrane receptors in amoeboid microglial cells is related to their active role in endocytosis. These, however, diminish with the growth of the brain.
    Materialart: Digitale Medien
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  • 25
    ISSN: 1432-0568
    Schlagwort(e): Astrocyte ; Radial astrocyte ; GFAP ; Electron microscopy ; Phylogeny
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The astroglial cells have been studied in the lizard spinal cord by means of metallic impregnations, immunohistochemical (glial fibrillary acidic protein) and ultrastructural methods. Three astroglial cell types have been immunohistochemically identified: ependymocytes, radial astrocytes and astrocytes. Transitional forms have also been observed. Scarce immunopositive ependymocytes were located in the dorsal and ventral regions of the ependyma. The radial astrocytic somata were located around the ependymal layer and their processes reached the subpial glia limitans. Typical astrocytes were the most abundant astroglial cell type; astrocytes located in the ventral horn showed a greater development than those of the dorsal horn. In the white matter, the astrocytes were large and their processes formed part of the subpial glia limitans; on some occasions, astrocytic cell bodies also formed part of this subpial limitans. Transitional elements between astrocytes and radial astrocytes were observed in both grey and white matter. The perivascular and subpial glia limitans were continuous and showed a strong immunoreactivity. The comparative analysis of our results in the lizard spinal cord with those in other vertebrate groups leads us to conclude that reptiles could represent the key group in the phylogenetic evolution of the astroglial cells in vertebrates.
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 282 (1990), S. 363-370 
    ISSN: 1432-069X
    Schlagwort(e): Autosomal recessive palmoplantar keratosis ; Electron microscopy ; Keratinization ; Keratohyalin ; Keratohyaline proteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A new kind of diffuse palmoplantar keratoderma with autosomal recessive inheritance and without associated symptoms was described in Norrbotten, Sweden by Gamborg Nielsen in 1985. Clinically, it ranges between the less severe dominant Unna-Thost type and the more severe recessive Meleda type, as it is milder than the latter. Skin biopsies of five patients from three different families with this new palmoplantar keratoderma, as well as five obligatory heterozygotes from one family, were investigated ultrastructurally in order to characterize this new entity and to differentiate it from the Meleda type. Several features are common to both autosomal recessive palmoplantar keratoses. They show a broadened granular layer, a transit region consisting of cells with a marginal envelope, and considerable hyperkeratosis. Morphologically, this transformation delay is less pronounced in the Gamborg Nielsen type than in the classical Meleda type. As is typical for ridged skin, both types of palmoplantar keratoses possess composite keratohyaline granules. In contrast to the normal appearance of keratohyaline granules in the Meleda type, the Gamborg Nielsen type also shows qualitative deviations of keratohyaline granules with different degrees of spongiosity and electron density and sometimes with a granular border. It seems that abnormal keratohyaline proteins are synthesized that behave differently. The sudden transformation of a granular into a horny cell is physiologically regulated by different enzymes. A delay in this process may be caused by a mutation that reduces or alters the enzymes concerned. We assume the palmoplantar keratoderma of the Gamborg Nielsen type to be a variant of the heterogeneous group of the Meleda type of palmoplantar keratoderma with autosomal recessive inheritance.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 282 (1990), S. 402-407 
    ISSN: 1432-069X
    Schlagwort(e): Electron microscopy ; Culture ; Hair cells ; Growth ; Differentiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The cultured hair cells from 4-day-old C3H mice were studied by electron microscopy. The hair roots isolated from the skin by collagenase digestion were dispersed into a cell suspension by treatment with a mixture of trypsin and ethylenediaminetetraacetate. The cells were cultured in MCDB-153 (a medium containing seven growth factors) for 1, 3, 6 or 13 days. The number of cultured cells on day 3 was twice that on day 1, and stayed at the same level until day 13. By electron microscopy, some of the cells cultured for 1 day were seen to be undifferentiated and others already showed differentiation into various hair structures. Such differentiated cells disappeared on day 3 and most of the cells cultured for 3 days were undifferentiated. Cells cultured for 6 days were differentiated showing inner root sheath cell, hair cortical cell and medulla cell structures. The characteristics of these cultured cells corresponded well to those of in vivo cells of the hair tissues from the back skin of 7-day-old C3H mice. On day 13 degeneration occurred in the cultured cells. In none of these cultures were mesenchymal cells, such as fibroblasts, found. The present electron microscopic study reveals that immature cells obtained from mouse hair tissues proliferate in vitro and differentiate into several subpopulations corresponding to those of in vivo cell layers of hair tissues. The present culture technique may be useful for studies of hair cell growth and differentiation.
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 282 (1990), S. 12-16 
    ISSN: 1432-069X
    Schlagwort(e): Immunogold ; Electron microscopy ; Eccrine sweat glands ; Keratin ; Fucose
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Human eccrine sweat glands were embedded in Lowicryl K4M. Cytokeratin proteins and blood group H antigen were localized by applying a postembedding immunogold method using a monoclonal antikeratin antibody and the lectin Ulex europaeus I. The antikeratin antibody labeled intermediate filaments in the secretory coil and dermal duct. Within dark secretory cells bundles of filaments criss-crossing the cell were labeled. Within the luminal cells of the dermal duct filaments arranged parallel to the cell surface and lying in the apex of the cell were labeled, too. The association of keratin filaments with desmosomes was visualized demonstrating their subcellular connection with other cell organelles. The desmosomes themselves remained unlabeled. The lectin Ulex europaeus I is a blood group H specific lectin and binds to α-l-fucosyl-containing glycoproteins. Dark cells of the secretory coil reacted with the lectin. Here the secretory granules, the lateral cell membranes, and the microvilli membranes were labeled. The endoplasmatic reticulum, the Golgi complex, and transport vesicles were not labeled, although the glycoprotein synthesis is considered to be located in the Golgi complex. Thus, either the number of α-l-fucose molecules in the Golgi is too low to be detected by the technique employed or the determinant of blood group H antigen is released after the secretory granules and transport vesicles leave the Golgi complex.
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 282 (1990), S. 71-75 
    ISSN: 1432-069X
    Schlagwort(e): Bicomponent keratohyalin ; Ridged skin ; Keratinization ; Sweat ducts ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Up to now, bicomponent keratohyalin has only been described for rat epithelium and human intraepidermal sweat ducts and fetal nail organ cells. In normal human interductal epidermis, the keratohyalin appears homogeneous, osmiophilic and stellate in shape. Under pathological conditions, bicomponent keratohyalin has been observed in different palmoplantar keratoses and has therefore been thought to be associated with abnormal keratosis. We studied the keratinization process in normal human plantar epidermis, in which keratohyalin was found to exhibit several morphological differences as compared to that seen in non-ridged skin. The most striking feature was seen in upper granular cells, where the keratohyalin granules consisted of two components of differing electron density. The electron-dense component formed the main part of the composite granule and was found in the cytoplasm of lower and upper granular cells. The less-electron-dense component was attached to the main component and appeared in the cytoplasm of upper granular cells, forming the convex contact zone. No intranuclear osmiophilic inclusions were present. The respective electron densities of the two keratohyalin components of ridged skin were obviously different to that of the bicomponent keratohyalin granules seen in the epidermal sweat-duct cells of the same specimen. These findings indicate the presence of at least two different types of keratohyalin proteins in normal human ridged skin. They can be distinguished at the electron-microscope level and differ from the keratohyalin of human non-ridged skin as well as from bicomponent keratohyalin granules derived from human epidermal sweat-duct cells or from rat epithelium.
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 282 (1990), S. 227-233 
    ISSN: 1432-069X
    Schlagwort(e): Genodermatoses ; Keratinization disorders ; Fetal cytokeratins ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The pathogenesis of a rare form of the ichthyotic diseases, ichthyosis hystrix Curth-Macklin, was investigated by immunohistochemistry and electron microscopy. Monoclonal antibodies (Mabs) against keratins expressed in normal basal cells (PKK2 and KA1), Mabs against keratins only present in normal fetal skin (PKK1), and Mabs against keratins 1, 2, 10, and 11 (KA5 and K8.60) were used. The Mabs reacting with normal basal cells showed an increased reaction with many cell layers. The Mab PKK1 distinctly reacted with the basal cell layer, suggesting an expression of fetal keratins. Electron microscopic study of both normal-looking and involved skin revealed the keratinization disorder characterized by tonofilament shells, perinuclear vacuoles, and binuclear keratinocytes. The results suggest that there is no prematurity of keratinization, but rather a pathological expression of specific keratin genes leading to expression of fetal keratins in this form of ichthyosis hystrix.
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  • 31
    ISSN: 1432-0584
    Schlagwort(e): Electron microscopy ; Leukemia ; Minimally differentiated leukemia ; Childhood
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural, light microscopical and immunological features of twelve cases of acute childhood leukemia are described. Nine cases were unclassifiable by light microscopy, morphology and cytochemistry, and three were difficult to classify because of a low percentage of Sudan-Black B positive blasts. By means of electron microscopy (including peroxidase cytochemistry), two main groups were seen: 1. Acute myeloid leukemia, in which could be distinguished a) a more differentiated myeloid leukemia, b) a leukemia with megakaryoblastic involvement and c) a minimally differentiated acute myeloid leukemia with granules present and 2. lymphoblastic leukemia. One case could not be classified. The first group included two possible cases of a hybrid leukemia with CD19 or CD10 positivity as well as ultrastructural peroxidase activity. We conclude that electron microscopy aids to further classification of minimally differentiated and hybrid acute leukemias.
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  • 32
    ISSN: 1432-1106
    Schlagwort(e): Hypoglossal nucleus ; Catecholamines ; Norepinephrine ; Immunocytochemistry ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A correlative light and electron microscopic investigation was undertaken to determine the morphology and distribution of catecholamine (CA)-containing axon terminals in the hypoglossal nucleus (XII) of the rat. This was accomplished immunocytochemically with antibody to tyrosine hydroxylase (TH). The major findings in this study were the following: 1) Immunoreactive profiles were found throughout XII and included unmyelinated axons, varicosities, axon terminals and dendrites; 2) Nonsynaptic immunoreactive profiles (preterminal axons, varicosities) were more frequently observed (55.2%) than synaptic profiles (43.5%); 3) CA-containing axon terminals ending on dendrites were more numerous (71.8%) than those synapsing on somata (25.4%) or nonlabeled axon terminals (2.7%); 4) The morphology of labeled axon terminals was variable. Axodendritic terminals typically contained numerous small, round agranular vesicles, a few large dense-core vesicles and were associated with either a symmetric or no synaptic specialization, axosomatic terminals were often associated with a presynaptic membrane thickening or a symmetric synaptic specialization and contained small, round and a few elliptical-shaped vesicles, while axoaxonic synapses formed asymmetric postsynaptic specializations; and 5) CA-positive dendritic processes were identified in XII. These findings confirm the CA innervation of XII, and suggest a complex, multifunctional role for CA in controlling oro-lingual motor behavior.
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric nephrology 4 (1990), S. 463-469 
    ISSN: 1432-198X
    Schlagwort(e): Juvenile chronic arthritis ; Renal amyloidosis ; Chlorambucil ; Electron microscopy ; Protein AA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Over a 22-year period, eith patients affected with severe systemic or polyarticular juvenile chronic arthritis (JCA) developed systemic amyloidosis with nephrotic syndrome. They were treated with chlorambucil over 5–192 months (mean=44 months). With treatment, an abrupt decrease in the severity of JCA was observed in six patients but two patients were chlorambucil resistant. After a mean follow-up period of 10 years from onset of renal symptoms, one chlorambucil-resistant patient died of end-stage renal failure; two patients have a persistent nephrotic syndrome; and five patients are free from proteinaria, of whom one has developed hypertension. A good correlation was observed between the response of the rheumatic disease to chlorambucil treatment and the clinical course of renal symptoms. Fourteen renal biopsies were performed in these eight patients. In all, amyloid deposits were of the AA type, which persisted on repeat biopsies. In addition, 15%–60% of glomeruli had become globally sclerotic by the second or third biopsies. At the ultrastructural level, modifications in the structure of amyloid deposits and reparative changes of the glomeruli, characterized by partial restoration of glomerular architecture, were observed in three patients with a favourable clinical course.
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  • 34
    ISSN: 1432-1076
    Schlagwort(e): Electron microscopy ; Liver ; MCAD deficiency ; Reye syndrome
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Inborn errors involving the oxidative metabolism of fatty acids may present clinically with a Reye syndrome-like picture. This case report of a patient with medium-chain acyl CoA dehydrogenase (MCAD) deficiency illustrates that electron microscopy may help to differentiate this disorder from Reye syndrome even if a liver biopsy is performed in a patient who recovered from an acute metabolic decompensation. Together with this case, a review of the few reports in the literature of pathological findings in MCAD deficiency is given. Changes uncharacteristic for Reye syndrome are a largedroplet steatosis and the presence of distinctive mitochondrial abnormalities on electron microscopy. The detection of an electron dense mitochondrial matrix and a widened space of inner mitochondrial membranes rules out Reye syndrome and is suggestive of a disorder of mitochondrial fatty acid oxidation.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neurology 237 (1990), S. 39-41 
    ISSN: 1432-1459
    Schlagwort(e): Progressive subcortical vascular encephalopathy ; Electron microscopy ; Nerve fibres ; Corpus callosum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The nerve fibres of the corpus callosum were studied by electron microscopy in five elderly patients with progressive subcortical vascular encephalopathy (PSVE) and compared with those in six age-matched controls. The number of nerve fibres per unit area of the corpus callosum was decreased in PSVE by 18–26%. The loss of nerve fibres in the corpus callosum can play a role in inducing the cognitive deficit of PSVE, on the basis of the loss of nerve fibres in the cerebral hemispheres.
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neurology 237 (1990), S. 88-93 
    ISSN: 1432-1459
    Schlagwort(e): Amyloid-rich primitive plaque ; Diffuse plaque ; Amyloid ; Periodic-acid methenamine silver method ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In Alzheimer-type dementia brains, numerous “amyloid-rich primitive plaques (PPs)” were observed with β-protein immunostaining and periodicacid methenamine (PAM) staining. These amyloid-rich primitive plaques were accompanied by various degrees of small argyrophilic rod-like, granular or filamentous structures. Routine and modified-PAM electron microscopy revealed many bundles and flecks consisting of amyloid fibrils scattered widely throughout the plaques. Degenerate neurites, astrocytic processes and bundles of glial fibres also participated in the formation of the plaques. The similarities and differences between these amyloid-rich primitive plaques and diffuse plaques are described.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neurology 237 (1990), S. 382-384 
    ISSN: 1432-1459
    Schlagwort(e): Intracerebral sarcoma ; Meningeal sarcoma ; Light microscopy ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of a primary intracerebral sarcoma is described in a 5-year-old girl. Histology and immunohistochemistry excluded the diagnosis of a leiomyosarcoma, a malignant haemangiopericytoma or a fibrosarcoma; electron-microscopical findings indicated that the origin of the sarcoma was in the pia mater.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 116 (1990), S. 517-524 
    ISSN: 1432-1335
    Schlagwort(e): Tumor vascularization ; Tumor blood flow ; Xenograft ; Nude mouse ; Vascular corrosion cast ; Ultrastructure ; Electron microscopy ; Heterogeneity ; Vessel morphology ; Morphometry ; Necrosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This study was designed to examine the vascular system of human xenotransplanted tumors on nude mice with different complementary morphometrical and morphological methods. The vascular system shows a chaotic arrangement. There is an extreme heterogeneity in the vascular distribution and density. Large avascular regions could be identified in several non-necrotic tumors. There was no clear difference in the vascular density between the center and the periphery of the tumors, nor was there any zonal correlation for the distribution of the necrosis. With three-dimensional corrosion casts it could be demonstrated that clusters of vessels were directly beneath areas almost free of vessels. In the center, vessels often form a sinusoidal system with numerous blind ends without clearly discernible endothelial cells. Numerous irregular tumor-cell-lined sinusoids are visible next to endothelial-lined vessels with transmission electron microscopy. With scanning electron microscopy it could be demonstrated that large-calibre endotheliazed vessels were found in the direct vicinity or in the center of non-viable zones. Even large-calibre vessels have a capillary wall structure. Sometimes, a basement membrane cannot be observed at all or only incompletely. There are numerous indications of vascular discontinuities and leaks with a widespread intercellular occurrence of blood cells.
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  • 39
    ISSN: 1432-0878
    Schlagwort(e): Testis ; Mast cells ; Estrogen ; Cytochemistry ; Electron microscopy ; Rat, Wistar
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The accumulation of mast cells in the testicular interstitium of neonatally estrogen-treated rats was studied from 15 to 90 days of age. The maturation of these cells was assessed by ultrastructural analysis and their histochemical properties were examined with the sequential alcian blue-safranin staining method. The first identifiable mast cells appeared in the testis at 17–20 days of age, as immature cells with proliferative capacity. The density of mast cells increased up to 45 days of age, showing a slight decrease from 45 to 90 days of age. Before 45 days of age, most mast cells showed alcian blue-stained granules, whereas at 45 days of age, most cells presented a mixture of alcian blue and safranin-stained granules. From this age onward, most cells were stained with safranin. These maturational changes were well-correlated with their ultrastructural features. Mast cells presented few and heterogeneous immature granules up to 45 days of age, and many uniform electron-dense granules at 90 days of age. These results indicate that the testicular interstitium of neonatally estrogen-treated rats provides an adventageous environment for the recruitment, proliferation and maturation of connective tissue mast cells.
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 260 (1990), S. 41-48 
    ISSN: 1432-0878
    Schlagwort(e): Keratin filament ; Circumvallate papilla ; Taste bud ; Immunocytochemistry ; Electron microscopy ; Mouse (dd)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Keratin filaments of epithelial- and taste-bud cells in the circumvallate papillae of adult and developing mice were studied by immunocytochemistry using monoclonal antikeratin antibodies (PKK2 and PKK3) and by conventional electron microscopy. Elongated cells (type-I,-II, and-III cells) of the taste buds were stained by PKK3 antibody, which reacts with 45-kdalton keratin, whereas basal cells of the taste buds and surrounding epithelial cells showed negative staining with PKK3. Such PKK3-reactive cells occurred at 0 day after birth, when taste-buds first appeared in the dorsal surface epithelium of the papillae. Thus 45-kdalton keratin seems to be an excellent immunocytochemical marker for identifying taste-bud cells. Epithelial cells in all layers of the trench wall and basal layer cells of the dorsal surface contained densely aggregated bundles of keratin filaments that reacted with PKK2 antibody, but not with PKK3. In contrast, taste-bud cells and spinous and granular layer cells of the dorsal surface possessed loose aggregated bundles of filaments that reacted with PKK3, but not with PKK2. These results suggest that the aggregation and distribution pattern of keratin filaments may reflect differences in the keratin subtypes that comprise these filaments.
    Materialart: Digitale Medien
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  • 41
    ISSN: 1432-0878
    Schlagwort(e): Vitamin A-deficiency ; Paneth cells ; Crystalloid lysozyme ; Tubular structures ; Intestinal local immunity ; Electron microscopy ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of vitamin A-deficiency on jejunal Paneth cells in rats was investigated. Crystalloid particles were observed in secretion granules of Paneth cells from 6 out of 8 rats with vitamin A-deficiency. The particles were similar to those found in Paneth cells under other experimental conditions. Using an immuno-electron-microscopic technique we demonstrated a clear lysozyme immunoreactivity of these particles. In 2 vitamin A-deficient rats tubular structures have been detected in addition to the crystalloid particles. Crystalloid particles or tubular structures were not detectable in a control group of 8 vitamin A-supplemented rats. The morphological alterations of Paneth cells may be correlated to an impaired local immunity of the intestine during vitamin A-deficiency.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 260 (1990), S. 409-414 
    ISSN: 1432-0878
    Schlagwort(e): Kidney ; Peroxisomes ; Marginal plates ; Electron microscopy ; Freeze-etching ; DAB-cytochemistry ; Bovine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of peroxisomes in the proximal nephron tubules of bovine kidney cortex was studied using ultrathin-sectioning, diaminobenzidine cytochemistry for the visualization of catalase, and by freeze-fracture. Peroxisomes in this nephron segment are up to 1.5 μm in diameter and exhibit a peculiar angular shape, which is probably related to the occurrence of multiple straight plate-like inclusions (marginal plates) in the matrix of peroxisomes; they lie directly underneath the peroxisomal membranes. The peroxisomal membrane in such regions follows the outline of the marginal plate. The peculiar shape of peroxisomes allows their unequivocal identification in freeze-fracture preparations. Peroxisomal membranes are recognized by their flat, often rectangular appearance. Intramembrane particles are much more numerous on P-fracture faces than on E-fracture faces. A crystalline lattice-structure with a periodicity of approximately 10 nm can be observed on the flat rectangular areas of E-fracture faces. This lattice structure is intensified after prolonged freeze-etching. Intramembranous particles seem to be superimposed over this pattern. The crystalline pattern on the E-fracture faces of peroxisomal membranes is probably not a membrane structure but it reveals the structure of the membrane-associated marginal plates. A cast of the marginal-plate surface may be generated by a collapse of the peroxisomal membrane half onto the immediately underlying matrix inclusion.
    Materialart: Digitale Medien
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  • 43
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptide Y ; Arginine vasopressin ; Co-storage ; Immunohistochemistry ; Electron microscopy ; Paraventricular nucleus ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Certain populations of arginine vasopressin (AVP) neurons in the magnocellular paraventricular nucleus became immunoreactive for neuropeptide Y (NPY) when rats were treated with colchicine or monosodium glutamate (MSG). The co-storage of these peptides was examined by empooying a post-embedding electron-microscopic immunohistochemistry technique using goldlabeled antibodies to the two peptides. In colchicinetreated rats, the neuronal perikarya contained numerous secretory granules showing co-storage of the two peptides. The cells of the MSG-treated rats were characterized by having well-developed Golgi bodies with the granular structures also co-storing the two peptides, although the secretory granules in the perikarya were rather fewer than in the colchicine-treated rats. It is concluded that the destruction of the arcuate nucleus by MSG-treatment may potentiate the synthesis of NPY in AVP neurons, the synthesis of which is latent in intact animals.
    Materialart: Digitale Medien
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  • 44
    ISSN: 1615-6102
    Schlagwort(e): Anther embryogenesis ; Brassica napus ; Electron microscopy ; Histochemistry ; Microspore embryogenesis ; Pollen division
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Ultrastructural and cytochemical features of embryo development during anther and free microspore culture inBrassica napus have been followed from the late uninucleate microspore stage through the first embryonic division. On transfer to culture, the microspore cytoplasm possesses a large vacuole, often containing electron opaque aggregates, and a peripheral nucleus. Mitochondria, endoplasmic reticulum and starch-free plastids are distributed throughout the cytoplasm. The conditions of culture induce a number of major changes in the cytoplasmic organisation of the microspore. First, the central vacuole becomes fragmented allowing the nucleus to assume a central position within the cell. Secondly, starch synthesis commences in the plastids which, in turn, are seen to occupy a domain investing the nucleus. Thirdly, the cell develops a thick fibrillar wall, situated immediately adjacent to the intine of the immature pollen wall. Finally, the microspores develop large cytoplasmic aggregates of globular material. The nature of this substance remains unknown, but it remains present until the young embryos have reached the 30 cell stage. The first division of cultured microspores destined to become embryos is generally symmetrical, in contrast to the asymmetric division seen in normal development in vivo. Consideration is given to the differences observed between embryos developing from anthers and free microspores in culture.
    Materialart: Digitale Medien
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  • 45
    Digitale Medien
    Digitale Medien
    Springer
    Protoplasma 153 (1990), S. 149-156 
    ISSN: 1615-6102
    Schlagwort(e): Acid phosphatase ; Electron microscopy ; Mammary glands ; Subcellular fractions ; Substrate specificity ; Sulfhydryl agents ; Tartrate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Localization of acid phosphatase in mammary glands of lactating rats was studied by both biochemical and cytochemical methods. Cytochemically, acid phosphatase activity was detected by using lead citrate as the capture agent for the inorganic phosphate released from p-nitrophenyl phosphate. The activity was predominantly localized in the lumina of the endomembrane system and in the milk that had been secreted into the alveolar lumen. Biochemically, acid phosphatase was present in all the subcellular fractions with higher activities in the membrane-associated fractions. The localization of tartrate-resistant acid phosphatases within the endomembrane system of fully lactating rat mammary tissue suggests a possible role for these enzymes in milk secretory processes.
    Materialart: Digitale Medien
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Protoplasma 154 (1990), S. 132-143 
    ISSN: 1615-6102
    Schlagwort(e): Vigna sinensis ; Immunofluorescence ; Electron microscopy ; Colchicine ; Tubulin reticulum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The primary leaf, epicotyl, and root cells ofVigna sinensis seedlings grown continuously in a 0.08% colchicine solution, become microtubule-free and polyploid. In meristematic root cells a tubulin transformation is detected 1–3 h after the treatment had begun. Tubulin strands are organized at the positions of the pre-existing microtubules. Frequently, the strands converge on or are organized in the cortical cytoplasmic zone where in normal cells the preprophase microtubule band (PMB) is assembled. In meristematic root cells subjected to a 6–12 h colchicine treatment, the tubulin strands become perinuclear, entering the cortical cytoplasm at regions close to the nucleus. One day after the onset of the treatment, tubulin generally forms a continuous reticulum of interconnected strands in all the organs examined. In most cells this reticulum surrounds the nucleus partly or totally or lies close to it, exhibiting variable configurations in different cells. After prolonged treatments, the organization of the tubulin reticulum changes further. Now this consists of crystal-like structures interconnected by thin strands. On thin sections of fixed tissue the tubulin strands consist of paracrystalline material. The distribution of this material in the affected cells coincides with that of tubulin reticulum visualized by immunofluorescence. In transverse planes each strand exhibits circular subunits arranged close to one another in a hexagonal pattern but in longitudinal ones variable images were observed. The paracrystalline material persists in root cells subjected to an 8-day continuous colchicine treatment. The immunolabeled strands seem to be composed of tubulin-colchicine complexes and not pure tubulin.
    Materialart: Digitale Medien
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 247 (1990), S. 189-193 
    ISSN: 1434-4726
    Schlagwort(e): Spiral ganglion ; Lipofuscin ; Ceroid ; Vitamin E deficiency ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The purpose of the present study was to clarify morphological differences in lipofuscin or so-called age pigments observed in the spiral ganglion cells of both young and adult rat groups and to characterize the size and structure of ceroid pigment granules generated in vitamin-E-deficient rats. The results showed different patterns of lipofuscin distribution in the two groups. The adult rat group had large aggregated lipoid, dark pigment granules of irregular shape in the cytoplasm. In contrast, the young group had small numbers of small, dense homogeneous granules, suggesting higher Schwann cell phagocytic activity. The ceroid pigments apparently included numerous vesicles and droplets of more variable density and size than the lipofuscin pigments appearing in the non-treated older animals. Both lipofuscin and ceroid pigments developing in such non-dividing cells are produced as a result of peroxidation reactions, so that the more they accumulate in the cytoplasm the more likely cell function deteriorates. The present study has shown that lipofuscin/ceroid granules are generated in the spiral ganglions under either endogenous (aging) or exogenous (vitamin E deficiency) conditions.
    Materialart: Digitale Medien
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 247 (1990), S. 237-239 
    ISSN: 1434-4726
    Schlagwort(e): Hyaluronate ; Hyaluronidase-gold ; Nasal mucosa ; Goblet cells ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural distribution of hyaluronate in the nasal mucosa of Wistar rats, especially in secretory cells, was examined by hyaluronidase-gold labeling using electron microscopy. The main secretor of hyaluronate in the nasal mucosa was found to be the goblet cells and not the nasal glands.
    Materialart: Digitale Medien
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 247 (1990), S. 240-243 
    ISSN: 1434-4726
    Schlagwort(e): Organ of Corti ; Limax flavus ; Feutin-gold ; Electron microscopy ; Sialic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The localization of sialic acid (N-acetyl- and N-glyconylneuraminic acid) in the organ of Corti of the mongolian gerbil was examined with electron microscopy by postembedding labeling using Limax flavus agglutinin and feutin-gold. Gold labeling was observed on the fibrous structure of the tectorial membrane, the basilar membrane and the spiral limbus. The labeling was also observed on the cuticular plate of the hair cells, the head and cone of the pillar cells and the head plate of Deiters' cells and other supporting cells. Collagen or cytoskeletal glycoproteins are suggested to be the source of the sialic acid in these structures.
    Materialart: Digitale Medien
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 248 (1990), S. 57-62 
    ISSN: 1434-4726
    Schlagwort(e): Vestibular membrane ; Reissner's membrane ; Mesothelium ; Fixation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The mesothelial cells of Reissner's membrane in guinea pigs were found to be connected by junctional complexes. No cell discontinuities or gaps were observed by scanning or transmission electron microscopy. These results are not in accordance with previous studies. They were achieved by in vivo vascular perfusion fixation, handling of cochleae in protective specimen carriers, thiocarbohydrazide treatment and continuous dehydration. Findings in the present study indicate that the interepithelial space between the epithelial and mesothelial cell layers constitutes a specific compartment which must be considered when examining solute transport over Reissner's membrane.
    Materialart: Digitale Medien
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  • 51
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 26 (1990), S. 30-39 
    ISSN: 1040-452X
    Schlagwort(e): Acrosome reaction ; Electron microscopy ; Acrosomal stain ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Three staining procedures to detect sperm acrosome integrity were compared via electron microscopy. Stains were applied to epididymal, freshly ejaculated, in vivo capacitated, and sonicated sperm cells in addition to spermatozoa displaying sequentially removed plasma and outer and inner acrosomal membranes. Sequential membrane removal procedures resulted in removal of plasma membranes from 73% of all sperm cells, removal of plasma and outer acrosomal membranes from 74% of all sperm cells, and removal of plasma and outer and inner acrosomal membranes from 87% of all sperm cells as determined by electron microscopy. Live/dead staining results were not statistically different from subjective microscopic motility evaluations (P 〈 0.005) for epiddymal, sonicated, freshly ejaculated, and in vivo capacitated sperm samples. All three stains assessed were similarly capable of detecting the acrosome status of freshly ejaculated and of sonicated spermatozoa compared to data obtained by electron microscopy (P = 0.010). However, only the Bryan-Akruk stain afforded data that were closely correlated with data obtained via electron microscopy for all sperm types assessed; the latter included in vivo capacitated spermatozoa and sperm cells rendered free of plasma membranes. Results confirmed an earlier report by successfully effecting sequential removal of rabbit acrosomal membrances and documented use of the Bryan-Akruk acrosomal stain for evaluation of sperm cell popualtions for fertilizing ability. These findings should prove useful in further investigations of mechanisms involved in achievement of fertilizing ability by rabbit spermatozoa.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
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  • 52
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 27 (1990), S. 351-365 
    ISSN: 1040-452X
    Schlagwort(e): Electron microscopy ; Sperm-egg interactions ; Polyspermic conditions ; Filipin ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: We have extended the observations of previous transmission electron microscopy studies of sperm-egg fusion to include those of freeze-fracture replicas showing sperm-egg interactions before, during, and following sperm head fusion with the egg membrane. Hamster eggs were incubated with hamster sperm under polyspermic conditions and were observed after a period of 5-30 minutes. After fixation, the eggs and sperm were exposed to filipin, which binds β-OH-sterols to form visible complexes in freeze-fracture replicas. Filipin can act as a marker for egg plasma membrane wherein it is abundant, while filipin is relatively scarce in the acrosome-reacted hamster sperm membrane, found only in the plasma membrane of the equatorial segment. The earliest sperm-egg interactions are observed between the egg microvilli and the perforatorium and the equatorial segment of the sperm, and the initial fusion between egg and sperm occurs in the vicinity of the equatorial segment. At later stages of fusion involving the postacrosomal segment, a clear line of demarcation is observed between the filipin-rich egg membrane and the filipin-poor sperm postacrosomal segment, suggesting that filipin binding lipids from the egg intercalate into the sperm membrane following membrane fusion. The anterior segment of the sperm does not fuse with the egg but is instead incorporated into a cytoplasmic vesicle derived from both sperm and egg membranes. In this latter step, filipin-sterol complexes are not found in sperm-derived membranes suggesting that there may be barriers to the movement of filipin binding lipids from the egg into these sperm membranes.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
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  • 53
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 27 (1990), S. 181-190 
    ISSN: 1040-452X
    Schlagwort(e): Testis ; Spermatogenic cells ; Bindin mRNA ; In situ hybridization ; Immunocytochemistry ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Expression of the bindin gene was examined in testicular cells of the sea urchin Strongylocentrotus purpuratus. In situ hybridization studies, using an 35S-labeled antisense RNA probe transcribed from a bindin cDNA, reveal that bindin mRNAs are localized in spermatogenic cells displaced towards the lumens of maturing testicular acini. Little or no hybridization is observed in spermatogenic cells displaced towards the perivisceral epithelium or in somatic cells of the testis. A similar localization of the bindin protein itself is observed using a rhodamine-conjugated polyclonal antibody against bindin, which shows a punctate immunofluorescence pattern in late spermatogenic cells. Immunogold labeling of ultrathin sections and electron microscopy reveal that this punctate immunofluorescence is an apparent result of localized deposits of bindin in intracellular vesicles. Through the terminal stages of spermatogenesis, these bindin-containing vesicles apparently fuse to form the single acrosomal vesicle of the mature spermatozoon. These results indicate (1) that bindin mRNAs are transcribed relatively late in spermatogenesis, (2) that bindin is translated soon after production of its mRNA, (3) that bindin quickly associates with intracellular vesicles during or soon after its synthesis, and (4) that these vesicles fuse to form the single acrosomal vesicle during the terminal stage of spermatogenesis.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 54
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 16 (1990), S. 160-166 
    ISSN: 0741-0581
    Schlagwort(e): Stopped-flow ; Rapid-freezing ; Freeze-fracture ; Electron microscopy ; Rapid reactions ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: We have developed an instrument capable of freezing transient intermediates in rapid biochemical reactions for subsequent freeze-fracturing, replication, and viewing by transmission electron microscopy. The machine combines a rapid mixing unit similar to one widely used in chemical kinetics (Johnson, 1986) with a propane jet freezing unit previously used to prepare static samples for freeze-fracturing (Gilkey and Staehelin, 1986). The key element in the system is a unique thin-walled flow cell of copper that allows for injection and aging of the sample, followed by rapid freezing. During freeze-fracturing, a tangential cut is made along the wall of the flow cell to expose the sample for etching and replication. The dead time required for mixing and injection of the reactants into the flow cell is less than 5 ms. Electronic controls allow one to specify, on a millisecond time scale, any time above 5 ms between initiation of the reaction and quenching by rapid freezing.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 55
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 16 (1990), S. 351-355 
    ISSN: 0741-0581
    Schlagwort(e): Drying ; Electron microscopy ; Frozen hydrated specimen ; Specimen preparation ; Vitrified specimen ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Evaporation of water cannot be fully avoided when an unsupported thin vitrified film of an aqueous suspension is prepared for cryo-electron microscopy. This results in increasing concentration of solute which could affect the observed material. We have quantitatively studied this effect by measuring the contrast of polystyrene spheres in a metrizamide solution. The drying effect is generally negligible when specimens are prepared on a hydrophilic perforated support but it is frequently important when hydrophobic films are used instead. A flow of humid air, double blotting with minimal exposure of the thin liquid film to the atmosphere, or an automatic plunger optimizing the blotting conditions are simple methods for reducing drying effects. With this third device acting on a hydrophilic supporting film, the increase of solute concentration is limited to less than 20%.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 56
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 14 (1990), S. 32-38 
    ISSN: 0741-0581
    Schlagwort(e): Electron microscopy ; Cell counts ; Nuclear shape ; Section compression ; Lung ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Counts of cells and nuclei from sections provide information central to studying structural changes in cells, tissues, and organs. This study considers some of the practical problems associated with counting cells with the newer random and serial sectioning methods of stereology and tests the hypothesis that similar cell counts can be obtained with both random and serial sectioning methods.Using irregularly shaped nuclei from alveolar cells of the goat lung, we compared cell counts derived from random (electron microscopic) and serial sectioning (light microscopic) methods. The results showed that both sectioning methods gave similar cell counts (107/cm3 of parenchyma) for type 1 epithelial cells (5.0 vs. 5.0; P=1.0), type 2 epithelial cells (8.6 vs. 9.8; P=0.42) and interstitial cells (34.6 vs. 33.4; P=0.64), provided that corrections were introduced for sectionrelated biases and that the nuclei of the random sectioning method were corrected for shape. We found counting biases of 5%-7% for nuclear shape and 16% for section compression. These observations support the hypothesis that similar cell counts can be obtained with random and serial sectioning, even when nuclei have irregular shapes.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 57
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 15 (1990), S. 332-351 
    ISSN: 0741-0581
    Schlagwort(e): Identified neurones ; Synaptic contacts ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: For more than a century the Golgi method has been providing structural information about the organization of neuronal networks. Recent developments allow the extension of the method to the electron microscopic analysis of the afferent and efferent synaptic connections of identified, Golgi-impregnated neurones. The introduction of degeneration, autoradiographic, enzyme histochemical, and immunocytochemical methods for the characterization of Golgi-impregnated neurones and their pre-and postsynaptic partners makes it possible to establish the origin and also the chemical composition of pre-and postsynaptic elements. Furthermore, for a direct correlation of structure and function the synaptic interconnections between physiologically characterized, intracellularly HRP-filled neurones and Golgi-impregnated cells can be studied. It is thought that most of the neuronal communication takes place at the synaptic junction. In the enterprise of unravelling the circuits underlying the synaptic interactions, the Golgi technique continues to be a powerful tool of analysis.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 58
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 15 (1990), S. 123-143 
    ISSN: 0741-0581
    Schlagwort(e): AChE ; ChAT ; Immunoreactivity ; Electron microscopy ; Acetyltransferase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: We have compared the biochemical expression of cholinergic enzymes with the morphological differentiation of efferent nerve fibers and endings in the cochlea of the postnatally developing mouse. Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) are present in the newborn cochlea at specific activities 63% and 25%, respectively, of their mature levels. The relative increases in ChAT, in AChE, and in its molecular forms over the newborn values start about day 4 and reach maturity by about day 10. The biochemical results correlate well with the massive presence of nerve fibers stained immunocytochemically for ChAT and AChE or enzymatically for AChE in the inner and outer hair cell regions. Ultrastructural studies, however, indicate the presence of only few vesiculated fibers and endings in the inner and outer hair cell regions. The appearance of large, cytologically mature endings occurs only toward the end of the third postnatal week. The discrepancy may be resolved in the electron microscope using the enzymatic staining for AChE. Labeling is seen on many nonvesiculated fibers and endings in the hair cell regions, suggesting that the majority of the efferent fibers in the perinatal organ may be biochemically differentiated but morphologically immature. The results may imply that the efferents to inner and outer hair cells develop earlier than indicated by previous ultrastructural studies. Moreover, the pattern of development suggests that in the cochlea, as in other tissues, the biochemical differentiation of the efferent innervation may precede the morphological maturation.
    Zusätzliches Material: 25 Ill.
    Materialart: Digitale Medien
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  • 59
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 15 (1990), S. 369-376 
    ISSN: 0741-0581
    Schlagwort(e): Lateral geniculate nucleus ; Electron microscopy ; HRP ; Structure/function correlations ; Identified neurons ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: During the past two decades new techniques have been developed to directly test the dogma that neuronal structure is correlated with neuronal function. In the earliest experiments, Procion yellow was injected into neurons after they had been characterized physiologically; these neurons were then viewed through the light microscope. Recent advances in the method generally employ horseradish peroxidase as the dye which is injected since it diffuses quite readily throughout the injected neuron and produces a stable reaction product for both light and electron microscopic studies. This review explores the utility of examining synaptic circuitry after physiologically recording from axons or neurons and then injecting horseradish peroxidase into them. As a model system, we studied the cat lateral geniculate nucleus and investigated, at the electron microscopic level, the synaptic contribution to this nucleus from retinogeniculate axons, from interneurons, and from the axon collaterals of neurons that project to visual cortex.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 60
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 16 (1990), S. 37-44 
    ISSN: 0741-0581
    Schlagwort(e): Small intestinal morphology ; Immunohistochemistry ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: In the present study, we modified the technique described by Altman et al. (J. Histochem. Cytochem., 32:1217-1223, 1984) for rapid embedding of tissues in Lowicryl K4M. To attain good sections of the small intestine that contained villi, crypts, submucosa, and external muscle layers, we cut 100 μm slices of the full thickness of the wall with a vibratome before embedment and then deoxygenated the resin and tissue before polymerization. The sections we obtained compared favorably with the quality of sections from conventional resins.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 61
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 15 (1990), S. 2-19 
    ISSN: 0741-0581
    Schlagwort(e): Acetylcholine ; Cholinergic fibers ; Electron microscopy ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Cholinergic synapses can be identified in immunocytochemical preparations by the use of monoclonal antibodies and specific antisera to choline acetyltransferase (ChAT), the synthesizing enzyme for acetylcholine (ACh) and a specific marker for cholinergic neurons. Electron microscopic studies demonstrate that the fibers and varicosities observed in light microscopic preparations of many brain regions are small-diameter unmyelinated axons and vesicle-containing boutons. The labeled boutons generally contain clear vesicles and one or more mitochondrial profiles. Many of these boutons form synaptic contacts, and the synapses are frequently of the symmetric type, displaying thin postsynaptic densities and relatively short contact zones. However, ChAT-labeled synapses with asymmetric junctions are also observed, and their frequency varies among different brain regions. Unlabeled dendritic shafts are the most common postsynaptic elements in virtually all regions examined although other neuronal elements, including dendritic spines and neuronal somata, also receive some cholinergic innervation. ChAT-labeled boutons form synaptic contacts with several different types of unlabeled neurons within the same brain region. Such findings are consistent with a generally diffuse pattern of cholinergic innervation in many parts of the central nervous system. Despite many similarities in the characteristics of ChAT-labeled synapses, there appears to be some heterogeneity in the cholinergic innervation within as well as among brain regions. Differences are observed in the sizes of ChAT-immunoreactive boutons, the types of synaptic contacts, and the predominant postsynaptic elements. Thus, the cholinergic system presents interesting challenges for future studies of the morphological organization and related function of cholinergic synapses.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 384 (1979), S. 29-44 
    ISSN: 1432-2307
    Schlagwort(e): Glomerulonephritis ; Cryoglobulinemia ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Renal tissue from five patients with cryoglobulinemia was studied by light and electron microscopy and immunofluorescence. None of the histologic features observed at the light microscopic level seems to be specific for cryoglobulinemia. Electron microscopic investigations have shown very large electron dense deposits in almost every examined lobule in all cases. The deposits displayed two main patterns; a homogeneous texture in two cases and tubular or annular structures in three cases. The patients with typically structured deposits had IgG-IgM cryoglobulinemia (2 cases) or monoclonal IgM cryoglobulinemia (1 case). The presence of IgM in cryoglobulinemia may be the cause of the peculiar structure of the deposits.
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 224 (1979), S. 17-23 
    ISSN: 1434-4726
    Schlagwort(e): Eighth nerve ; Inner ear ; Human ; Fluorescence microscopy ; Electron microscopy ; Menière ; Neurilemoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Fluorescence microscopy was used to examine the adrenergic, bloodvessel-independent innervation of the 8th nerve and inner ear specimens in patients with otoneurological diseases. Specifically fluorescent adrenergic axons were scantily seen among the myelinated nerve fibers in the 8th nerve and in the subepithelial regions of the end organs but not in the endolymphatic sac.
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Archives of gynecology and obstetrics 227 (1979), S. 103-117 
    ISSN: 1432-0711
    Schlagwort(e): Decidua ; Interzelluläre Verbindungen ; Gefrierätzen ; Elektronenmikroskopie ; Fibrinoid ; Decidua ; Intercellular junctions ; Freeze-fracturing ; Electron microscopy ; Fibrinoid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Cell contacts between developing decidual cells were examined in thin sections and in replicas of freeze-cleaved tissue of rat uterus. At the time of implantation only puncta adhaerentia were found between stromal cells. Gap junctions appeared 24 h after decidualization and thereafter increased in number and extent. Thus, there is little morphological evidence for a propagation of the initial stimulus for decidualization via gap junctions. An increase in amorphous, extracellular material is noted after decidualization with a concomitant decrease of collagen fibers. This amorphous material probably represents fibrinoid.
    Notizen: Zusammenfassung Die Zellkontakte zwischen sich entwickelnden Deciduazellen wurden sowohl mit der Dünnschnittechnik als auch mit der Gefrierätzmethode im Rattenuterus untersucht. Zum Zeitpunkt der Implantation wurden nur Puncta adhaerentia zwischen Stromazellen gefunden. Nexus (gap junctions) erschienen 24 h nach Beginn der Decidualisierung und nahmen danach an Zahl und Größe zu. Diese morphologischen Befunde widersprechen der Ansicht, daß sich der initiale Reiz für die Decidualisierung der Stromazellen über Nexus ausbreitet. Nach der Decidualisierung wurde eine Zunahme von amorpher, extrazellulärer Substanz gleichzeitig mit einer Abnahme von Kollagenfasern gesehen. Diese amorphe Substanz stellt wahrscheinlich Fibrinoid dar.
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  • 65
    ISSN: 1432-0827
    Schlagwort(e): Parathyroid hormone ; Osteoclasts ; Electron microscopy ; Morphometry ; Metaphysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The effects of parathyroid hormone (PTH) on the size of the osteoclasts, nuclei, ruffled borders, and clear zones in long bones of thyroparathyroidectomized (TPTX) rats were quantitated as a function of time. These data were compared with the number of osteoclasts in the bone and with plasma calcium levels. A significant increase in the average size of the ruffled borders was demonstrated 30 min after injection of 50 U of purified bovine PTH, and of the clear zones 30–90 min after PTH. This was followed at 90 min by an increase in the average size of the cells. The sizes of ruffled borders and clear zones dropped sharply to control levels after 6 h, whereas the size of the cells remained elevated up to 12 h and returned to control values at 24 h. Plasma calcium levels were increased, but not significantly, between 30 min and 6 h. An increase in the number of osteoclasts was significant after 12 h. Removal of the parathyroid glands did not diminish the normal activity of osteoclasts. In animals with intact glands injection of 50 U of PTH did not cause a significant change in cell size or resorbing apparatus. It is concluded that PTH acts to rapidly stimulate the bone resorptive activity of osteoclasts and to cause a delayed increase in their number.
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 34 (1979), S. 201-215 
    ISSN: 1432-1106
    Schlagwort(e): Intrahypothalamic connections ; Deafferentation ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Terminal degeneration within the hypothalamus was studied by electron microscopy 1 or 2 days (1) after carefully placed microlesions in the arcuate, anterior periventricular, ventromedial, premammillary and posterior hypothalamic nuclei and (2) after microlesions placed in the hypothalamus deafferented 3 weeks earlier. In the median eminence terminal degeneration was found after each of these lesions. Projections from the ventromedial nucleus reach the arcuate, suprachiasmatic, and anterior periventricular nuclei. Projections from the arcuate nucleus terminate in the medial preoptic, anterior periventricular, and ventromedial nuclei. After lesioning the premammillary nuclei degeneration was found in the supraoptic, arcuate, anterior hypothalamic and ventromedial nuclei.
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  • 67
    ISSN: 1432-1106
    Schlagwort(e): Hypothalamic paraventricular nucleus ; Spinal projection neuron ; Hypophyseal projection neuron ; Horseradish peroxidase ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The distribution of labeled neurons in the paraventricular nucleus of the hypothalamus (PVN) was studied following injections of horseradish peroxidase (HRP) into the spinal cord (C8 to T1) or the hypophysis in the rat. Injections were also made in the spinal cord in another group of animals, which were subjected to water deprivation for a period of 3 days, and the PVN of these animals was examined with the electron microscope. Spinal projection neurons (paraventriculospinal tract, PVST, neurons) formed two groups; the dorsal and the ventral groups. They were located within the parvocellular part of the PVN and fused into one at the caudal level. The neurons of the dorsal group were well assembled whereas those of the ventral group were intermingled with paraventriculohypophyseal tract (PVHT) neurons, which were concentrated in the magnocellular part. Electron microscopic observations revealed that HRP-labeled neurons after spinal injections did not contain neurosecretory granules and that they were not affected by water deprivation. On the other hand, neurons containing a number of neurosecretory granules displayed a significant degree of dilatation of the endoplasmic reticulum as the result of water deprivation. These neurons contained no HRP granules. The present findings suggest that the PVST neurons are distinct from the PVHT neurons and that the neuronal groups of both systems form different cell columns within the nucleus.
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 384 (1979), S. 269-284 
    ISSN: 1432-2307
    Schlagwort(e): Cerebro-hepato-renal syndrome ; Zellweger's syndrome ; Peroxisome deficiency ; Liver cirrhosis ; Liver biopsy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary For histologic differential diagnosis of fibrotic and cirrhotic liver changes in early infancy Zellweger's cerebro-hepato-renal syndrome has to be considered. A case is reported where a female newborn failed to thrive and developed severe muscular hypotonia, defective intelligence, and seizures. At an age of 12 months an open biopsy was taken from the enlarged liver. Biochemical tests for disorders of carbohydrate metabolism were negative. The light microscopic examination showed severe fibrosis, lobular disarray, and single cell necroses. Neither siderin nor bile pigment could be detected. There were no changes of the small bile ducts and no signs of inflammation — the child died at 18 months. A postmortem needle biopsy of the liver showed the advanced stage of micronodular cirrhosis. The electron microscopic examination of the first biopsy revealed hypertrophy of smooth endoplasmic reticulum, probably induced by anticonvulsive drugs. The mitochondria showed an increase in the density of their matrix and in the number of sometimes tubular cristae. In accordance with reports in literature, no regular peroxisomes (microbodies) could be found in the hepatocytes. Only a very few profiles with an average diameter of 0.16 μm looked like rather small peroxisomes. The cytoplasmic volume fraction of those organelles, however, amounted to 3×10−5 which is only 1/500 of the normal value in human hepatocytes. Although the significance of the absence of peroxisomes is not yet definitively proved, the term ‘Peroxisome Deficiency’ is proposed as a name which probably is more closely related to the pathogenetic mechanism than the hitherto usual designation cerebro-hepato-renal syndrome.
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 382 (1979), S. 283-291 
    ISSN: 1432-2307
    Schlagwort(e): Emiocytosis ; Endocrine cells ; Human embryo, child and adult ; Large intestine ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In endocrine cells of the colon of adults, children and fetuses, exocytotic granule release without any specific stimulation is reported. Omega-invaginations are observed on both the lateral and basal surfaces of all types of colonic endocrine cells. Several explanations for the phenomenon are suggested: 1) emiocytosis is probably more frequent in the colon than in the proximal gut, this allows its observation without requiring an exogenous stimulus, 2) since most of the exocytotic figures are from anaesthetized subjects it is also assumed that contraction of the muscular layer induced by anaesthetics and the resulting increase in intraluminal pressure were the possible causes of granule release, 3) in non-anaesthetized subjects release may have taken place in response to a normal endogenous physiological stimulus, or to the dilation of colon during colonoscopy. Less likely is an effect associated with the preparation for colonoscopy. Certain figures on lateral surfaces between endocrine and adjacent cells i.e., bulges of parallel plasma membranes surrounding a secretory granule, were observed. Their significance is unknown.
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 383 (1979), S. 167-179 
    ISSN: 1432-2307
    Schlagwort(e): Amyloidosis ; cyclic hematopoiesis ; Animal model ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron microscopy studies were made on tissues of cyclic hematopoietic (CH) dogs of various ages presenting a high incidence of spontaneous amyloidosis. The distribution and morphologic characteristics of amyloidosis in this animal model closely correspond to the secondary and familial forms of the disease in humans. Plasma cells and, particularly, macrophages presented marked changes during the evolution of amyloid deposition. Residual bodies in the macrophages contained abundant cell debris, a result of both endocytic and autophagocytic activities. Intracellular amyloid fibrils were not observed by conventional electron microscopy. A few reticular cells contained intracytoplasmic fibrils which were morphologically different from amyloid. There was no correlation between the amount of intracellular fibrils and the size of the extracellular amyloid deposits. On the contrary, a temporal association between the magnitude of the amyloid deposits and cytoplasmic changes in the macrophages at sequential stages of the evolution of the disease was evident. It is suggested that the hematopoietic defect in the CH dog could play an important role in the production of amyloidosis, making this animal an excellent experimental model for studies of that disease.
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 385 (1979), S. 117-124 
    ISSN: 1432-2307
    Schlagwort(e): Liposarcoma ; Breast ; Histopathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of primary liposarcoma of the breast in a 65-years-old woman is described by light- and electron microscopy. The patient had previously had a cystosarcoma phyllodes removed from the same area. A review of the literature showed 34 previously published cases of liposarcoma of the breast, which regarding age distribution, histological type and pattern of metastasis corresponded to liposarcomas of the lower limbs.
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  • 72
    Digitale Medien
    Digitale Medien
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    Anatomy and embryology 155 (1979), S. 209-219 
    ISSN: 1432-0568
    Schlagwort(e): Electron microscopy ; Metrial gland (rat) ; Pregnant uterus ; Degeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural changes occurring in the metrial gland in the latter half of pregnancy in the rat have been studied. Typical palely stained granulated cells are present in the metrial gland up to day 20 but many granulated cells show variations in appearance which may be associated with degeneration. In some the cytoplasm is more darkly stained and such cells often have apparently empty areas of cytoplasm adjacent to the granules. From day 14 onwards many areas of the gland show cellular debris, apparently resulting from lysis of the granulated cells. However, occasionally normal granulated cells are present in blood vessels and have been observed apparently penetrating the vascular endothelium. A variety of changes was also noted in the stromal cell population. Inclusions became apparent in many of these cells; some of these consisted of lipid while others resembled granules from the typical granulated cells. Other cells with numerous inclusions appeared to be macrophages. Lysis of granulated cells in situ is compatible with suggestions that the metrial gland produces a holocrine secretion, though some normal granulated cells enter blood vessels. The stromal cells may have a phagocytic role in late pregnancy but evidence for this was inconclusive.
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 157 (1979), S. 121-132 
    ISSN: 1432-0568
    Schlagwort(e): Limb bud ; Periderm ; Apical ectodermal ridge ; Electron microscopy ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Development of periderm cells covering fore-and hindlimb buds of mouse em`ryos was observed by scanning and transmission electron microscopy at half day intervals from day 9.5 to 12.5 of gestation (vaginal plug=day 0). At day 9.5, the epidermis is single layered. Occasional periderm cells are present at day 10.5. By day 11.5 a complete layer of periderm cells has covered the entire limb bud. By scanning electron microscopic observation, periderm cells covering the apical ectodermal ridge (AER) are characterized by a small surface size and an elongated polygonal shape with the long axis parallel to the antero-posterior contour of the apical rim. Periderm cells covering the dorsal and ventral surfaces of the limb bud are relatively large and have a polygonal surface shape. The periderm covering the apical tip reflects well the developmental state of the AER. Hence, it is possible to estimate the development of the AER by observing the surface features of the apical periderm by scanning electron microscopy.
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  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 158 (1979), S. 41-50 
    ISSN: 1432-0568
    Schlagwort(e): Placenta (human) ; Syncytiotrophoblast ; Intercellular junctions ; Electron microscopy ; Freeze-fracturing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Inter-and intrasyncytiotrophoblastic junctions within the human full term placenta were electronmicroscopically investigated using thin sections and freeze-fracturing. Narrow clefts were occasionally situated between surface areas where adjacent chorionic villi exhibited close contact. Whithin these clefts, extensive zonulae and maculae occludentes and numerous maculae adherentes were found. The zonulae occludentes showed a continuous and irregular course on the membrane surface, and the maculae occludentes were irregularly distributed over extended membrane areas. Besides these areas, maculae occludentes and maculae adherentes were observed on infoldings and invaginations of the syncytiotrophoblastic surface membrane. Investigations of the inner surface of the syncytiotrophoblastic layer, that is, the layer facing the villous stroma, also revealed invaginations joined by maculae adherentes. The functional significance of the inter-and intrasyncytiotrophoblastic junctions is discussed with respect to the differentiation of the trophoblast.
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 158 (1979), S. 51-62 
    ISSN: 1432-0568
    Schlagwort(e): Cerebellar cortex ; Pre-and postterminal blood vessels ; Rhesus monkey, cat, rat ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In the rhesus monkey, cat and rat, pial arteries give off branches which run vertically through all three layers of the cerebellar cortex. The large cortical arteries are surrounded by a perivascular space in the molecular layer. Their wall consists of several layers of smooth-muscle cells and the luminal endothelium. As the arteries reach the deeper layers of the cerebellar cortex, the number of smooth-muscle cells is reduced. In the rat, sometimes no smooth-muscle cells are detectable in the preterminal arterial vessels. If these deep arteries branch off by dichotomy of terminal vessels there occurs a gradual or complete loss of myocytes in all three species. In the cat, where cortical arteries give off branches at rightangles, there is a sphincter-like accumulation of smooth-muscle cells at the opening to the smaller branch. The postterminal vessels and veins in all species exhibit the smae mural structure found in capillaries. The wall consists only of an endothelium and occasional pericytes embedded in the basal lamina. Even the large veins which run to the pial veins show this simple mural structure.
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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 45 (1979), S. 53-59 
    ISSN: 1432-0533
    Schlagwort(e): Tangier disease ; Peripheral nerve ; Electron microscopy ; Cytometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A sural nerve biopsy was performed in a 55-year-old male patient with Tangier disease (familiallipoprotein deficiency). Light-microscopy showed an increase in the endoneural connective tissue and a loss of nerve fibers indicating a chronic peripheral neuropathy. Electron-microscopy revealed an accumulation of lipid droplets within Schwann cells of myelinated and unmyelinated nerve fibers. When compared with age-matched controls the myelinated fiber density was reduced with a relative preponderance of small myelinated fibers. In addition, distributional cytometric studies of nerve vibers in relation to the perineurium and endoneurial capillaries showed: Contrary to 4.6–7.5 μm thick nerve fibers, which accumulated in the center of the nerve fascicle, small (0.5–4.5 μm) and large (7.6–10.0 μm) fibers lay nearby the perineurium. The measured increase in small myelinated nerve fibers around endoneurial capillaries may be explained as a sign of regeneration.
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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 45 (1979), S. 133-140 
    ISSN: 1432-0533
    Schlagwort(e): Alexander's disease ; Rosenthal's fibers ; Peripheral Nerve ; Electron microscopy ; Neurochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The authors report the results of a cerebral and of a neuromuscular biopsies and of the autopsy findings in another infantile case of Alexander's disease in a girl. They review the 17 previously reported cases of this disease and the various etiopathogenic hypotheses mentioned. The presence of numerous, sometimes abnormal enlarged mitochondria and of abundant membranous cytoplasmic bodies in the astrocytic cytoplasm seems to be unreported elsewhere. Peripheral nerve changes are mentioned for the first time.
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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 46 (1979), S. 1-10 
    ISSN: 1432-0533
    Schlagwort(e): Dog ; Canine distemper virus ; Cell fusion ; Demyelination ; Encephalomyelitis ; Immunofluorescence ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The early neuropathological development of demyelinating Canine Distemper Encephalomyelitis (CDE) was studied in SPF dogs. Neural tissues were examined up to 30 days post infection (PI). Three phases of activity were observed. The primary event (first observed 8 days PI) was a nonsuppurative encephalomyelitis associated with the initiation of central nervous system (CNS) infection by virus-laden lymphocytes. At 24 days PI noninflammatory demyelination occurred in well defined, subependymal foci. Cell fusion and syncytia formation accompanied this early demyelination. The third phase, found at day 30 PI in one dog showing signs of recovery, was a second wave of nonsuppurative inflammation. The initial encephalomyelitis was widely disseminated throughout the CNS but subsequent demyelination appeared to be initiated from within the ventricular system. Myelin was phagocytosed by endogeneous CNS macrophages often infected with Canine Distemper Virus (CDV). The possible importance of viral induced cell fusion as well as immune factors in the mechanism of demyelination are discussed.
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  • 79
    Digitale Medien
    Digitale Medien
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    Acta neuropathologica 46 (1979), S. 25-32 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral blood vessels ; “Overgrowth” ; Embryonic development ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cerebral capillaries in “overgrown” neural tissue of chick embryo brains ranging in age from 5–18 days of incubation were studied by means of electron microscopy. The vessels in the abnormal tissue showed more extensive and prolonged interdigitations and overlapping of adjacent endothelial cells than did those in normal control brains. In the abnormal neural tissue the appearance and distribution of endothelial cell organelles was similar to that in normal tissue; however, the Golgi complex was less highly developed, and there was an increased amount of coated vesicles in the capillaries of the abnormal brains.
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 46 (1979), S. 85-94 
    ISSN: 1432-0533
    Schlagwort(e): Paramyxovirus infection ; Ependyma ; Choroid plexus ; Electron microscopy ; Immunofluorescence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of intracerebral inoculation of Sendai virus into young adult mice were investigated by immunofluorescence, light, and electron microscopy. Immunofluorescence of virus-specific antigens was maximal on the third day after inoculation, revealing infection of leptomeninges, ependyma, and choroid plexus. Histologically, meningitis, ependymitis, and choroiditis occurred between the second and third days. The choroiditis was associated with formation of vacuoles within the cytoplasm of epithelial cells. The vacuoles reached diameters up to 50 μm. The ubiquitous vacuolization of plexus epithelia resulted in a honeycomb-like pattern. Opaque viral inclusions were visible within the cytoplasm of choroidal and ependymal epithelium as well as in mononuclear inflammatory cells. On electron microscopy, they were composed of intracytoplasmic nucleocapsid accumulations. Viria lay free between microvilli of plexus epithelial cells, and budding virus structures were observed at cellular surfaces. Occasionally, complete viria occurred in the cytoplasm of plexus epithelial cells and were surrounded by a unit membrane from which they appeared to arise by budding. The formation of this small cavity can be interpreted as the first stage of vacuole formation.
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  • 81
    Digitale Medien
    Digitale Medien
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    Acta neuropathologica 46 (1979), S. 169-172 
    ISSN: 1432-0533
    Schlagwort(e): Giant axonal neuropathy ; CNS ; Dog ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The pathology of the central nervous system (CNS) in a dog with giant axonal neuropathy (GAN) is presented. Swollen axons containing excessive and disorganised neurofilaments were present in the spinal cord, mainly at the distal portions of long tracts. The fasciculus gracilis and dorsal spinocerebellar tracts were affected only in the rostral cervical cord while the lateral cortico spinal tract was principally involved in the lower thoracic and lumbar cord. Occasional swellings were also found in the central dorsal columns of the rostral lumbar segments and in the dorsal and intermediate grey matter. The nuclei gracilis and cuneatus, restiform body and ventral spinocerebellar tracts were all involved in the brain stem. Spheroids were seen in the white matter of the rostral cerebellar vermis and in the granule cell layer. The brachium of the superior colliculus contained swollen axons and the cortex was diffusely involved with spheroids. The distribution was of a distal axonopathy and the cortical changes provided an explanation for the abnormal EEG and mental retardation found in some human patients.
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  • 82
    Digitale Medien
    Digitale Medien
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    Acta neuropathologica 47 (1979), S. 1-11 
    ISSN: 1432-0533
    Schlagwort(e): Experimental Concussion ; Peroxidase, neuronal uptake ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Neuronal inundation with i.v. infused horseradish peroxidase was studied following concussive brain injury by means of both light and electron microscopy. In animals sustaining mechanical brain injury of insufficient intensity as to elicit either microscopic intraparenchymal hemorrhage or other neuropathological change, yet of sufficient intensity as to provoke a physiological concussive response, vascular peroxidase exudation concomitant with neuronal peroxidase inundation occurred throughout the raphe and reticular core. Initially such inundated neurons were totally flooded with the tracer and as such appeared reminiscent of cells visualized in Golgi preparations. However, over the course of a 24-h period these peroxidase flooded neurons apparently organized the peroxidase into vesicles and vacuoles which assumed a perinuclear position from where the peroxidase ultimately reached both the nucleus und nucleolus. It was remarkable that these events occurred without any evidence of subcellular alteration. We interpret such initial inundation with this protein tracer, its ultimate reorganization, and its nuclear and nucleolar uptake as being consistent with some form of subtle and transient neuronal perturbation. We speculate that as such this neuronal perturbation may constitute a morphological correlate of the concussive episode.
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  • 83
    Digitale Medien
    Digitale Medien
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    Acta neuropathologica 47 (1979), S. 237-240 
    ISSN: 1432-0533
    Schlagwort(e): Herpes simplex type 2 ; Herpes simplex encephalitis ; Cerebral metastasis ; Metastases and viral encephalitis ; Immunofluorescence ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A 62-year-old woman developed neurologic deficits 7 months after pulmonary lobectomy for alveolar cell carcinoma of the lung. CT scan of the head demonstrated two metastases with marked peritumoral edema. Administration of Decadron, chemotherapy and 3,000 rad cranial radiation resulted in dramatic inprovement of dysphasia and right hand paresis. Almost 2 months later, rhythmic, involuntary movements of the left hand developed. There was progression to multifocal seizures, grand mal seizures, postictal depression, status epilepticus, and coma, with death 9 days after onset of the movement disorder. Bronchoalveolar carcinoma was widely disseminated in lungs and bones, and as three metastases in brain. Bland “ischemic” necrosis in a pseudolaminar pattern was present in the neocortex. Innumerable Cowdry type A intranuclear inclusion bodies were seen in neurons, astrocytes, and oligodendroglia. Immunofluorescence demonstrated Herpes simplex virus type 2 antigen and electron microscopy revealed virions with the morphology of the Herpes group. The case is significant for (1) the concurrence of intracranial metastases and Herpes simplex encephalitis, and (2) the causal agent, Herpes simplex virus type 2. The implication for the clinical neurocientist is the potential in a patient with systemic cancer, for the causation of neurologic complications by more than one factor or mechanism.
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  • 84
    Digitale Medien
    Digitale Medien
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    Acta neuropathologica 48 (1979), S. 113-125 
    ISSN: 1432-0533
    Schlagwort(e): Complete cerebral ischemia ; Postischemic recirculation ; Electron microscopy ; Nuclear perturbations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Neuronal, astrocytic, and oligodendrocytic elements in several brain loci of the cat were examined at the light and electron microscopic level immediately after periods of complete cerebral ischemia (CCI) uncomplicated by post-ischemic recirculation. Such CCI episodes ranged from 1.5–25 min duration and were methodically produced in a cat model employing rigorous physiological controls. Subsequent to these CCI insults, morphological alterations occurred in a homogeneous manner within each cell type of all loci examined; however, variation in the temporal onset and magnitude of alterations among the various cell types was observed. With brief ischemic insults all cell nuclei demonstrated pronounced nuclear alterations, while their cytoplasmic organelles displayed minimal change. Chromatin clumping and nucleolar condensation were observed in both neurons and glia subsequent to 1.5–5 min of CCI, respectively. With increasing durations of CCI such changes were more dramatic and conspicuous alterations of the cytoplasmic organelles were observed. On the basis of extensive morphological analyses the present study illustrates that nuclear alterations are the first to occur subsequent to CCI. The homogeneity of neuronal involvement seen subsequent to CCI uncomplicated by post-ischemic recirculation is inconsistent with the “selective vulnerability” purported to occur by others. The significance of this inconsistency remains to be assessed; yet, the suggestion is advanced that post-ischemic recirculation may be a factor in the genesis of such vulnerability.
    Materialart: Digitale Medien
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 155 (1979), S. 23-36 
    ISSN: 1432-0568
    Schlagwort(e): Parotid gland ; Miniature pig ; Electron microscopy ; Innervation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This communication reports on the morphology of the parotid gland of miniature pigs (Göttingen strain). 1. The glandular system consists in its terminal portions of acinar secretory parts. Between the basal lamina and the secretory epithelial cells myoepithelial cells are located. 2. The cytoplasmic organization of the acinar cells represents the features of mucous secretory cells. By electron microscopic means, light secretory granules have been demonstrated which frequently are coalescent. Between the bulk of secretory material only small remnants of cytoplasm are visible. The electron dense nuclei are located in basal parts of the cells. Intercellular canaliculi have not been observed. 3. The intercalary ducts, located between the acinar portions and the striated ducts of the gland, are long and narrow tubules, frequently branched. Their epithelium is simple cuboidal, and there is no indication of any secretory activity. 4. The epithelium of the striated ducts is simple columnar. The orientation of mitochondria parallel to the cell axis, and also the invaginations of the basal cell membrane give the basal cytoplasm a vertically striated appearance. 5. The paravascular nerves of the gland's connective tissue consist of bundles of unmyelinated axons. These branch into smaller bundles, and finally into single unmyelinated axons which reach the acinar portions. These axons appear to be only partly surrounded by Schwann cells. Very thin axons alone penetrate the basal lamina and reach the secretory cells of the acini; moreover, these axons may occasionally reach the intercellular spaces between the secretory cells. Within these terminal parts of the axons groups of synaptic vesicles appear.
    Materialart: Digitale Medien
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 266 (1979), S. 253-267 
    ISSN: 1432-069X
    Schlagwort(e): Kaposi's sarcoma ; Histochemistry ; Electron microscopy ; Venous capillary endothelium ; Angioblast ; Kaposi-Sarkom ; Histochemie ; Elektronenmikroskopie ; venöse Kapillarendothelien ; Angioblast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Histochemische und ultrastrukturelle Untersuchungen bei zwei Patienten mit Kaposi-Sarkom ergaben, daß die Spindelzellen die Merkmale von venösen Capillarendothelien aufweisen.
    Notizen: Summary Histochemical and ultrastructural studies in two patients with Kaposi's sarcoma revealed that spindle cells have the pattern of venous capillary endothelium.
    Materialart: Digitale Medien
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 266 (1979), S. 295-310 
    ISSN: 1432-069X
    Schlagwort(e): Fibronectin ; Skin ; Basement membranes ; Immunohistochemistry ; Electron microscopy ; Fibronectin ; Haut ; Basalmembran ; Immunohistochemie ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Verteilung des extracellulären Glykoproteins Fibronectin im Haut- und Zungengewebe der Ratte wurde unter Verwendung von spezifischem Antiserum licht- und elektronenmikroskopisch mit Hilfe der Immunofluorescenz- und Immunoperoxidasemethoden untersucht. Aus den Ergebnissen schließen wir, daß Fibronectin weder in stabilen, differenzierten Gewebeteilen wie Talgdrüsen, Matrix, Mark, Rinde oder Cuticula des Haares oder der inneren und äußeren Haarwurzelscheide, noch in Geweben, in denen die Zellen zum Teil beweglich sind (z. B. Epidermis), vorkommt. Es ist aber charakteristisch für Zonen, wo Zellteilung in Berührung mit einem extracellulären Gerüst vor sich geht, wie z. B. an einer Basalmembran oder in lockerem Bindegewebe. Auffallende Beispiele waren die mit Follikelepithelien verbundene Hyalinmembran und Bindegewebsscheide, die unter Gefäßendothelzellen liegende Basalmembran, die Bindegewebe, welche die Nerven- und Muskelfaserbündel umgeben und durchsetzen und das Bindegewebe der Dermis. Im letzteren Falle war das Fibronectin oft mit Kollagenfasern eng verbunden. In der Basalmembran an der Grenze zwischen Dermis und Epidermis war Fibronectin an der Plasmamembran der basalen Zellen und im Gebiet der Lamina lucida zu finden. Es bestand kein Zusammenhang mit spezifischen Stellen der Zellen-Substrat-Adhäsion wie den Hemidesmosomen. Das endoplasmatische Reticulum der Fibroblaste ließ sich stark färben — ein Hinweis, daß diese Zellen einen wichtigen Ort der Synthese darstellen.
    Notizen: Summary Specific antiserum was used to investigate the distribution of the extracellular glycoprotein, fibronectin, in rat skin and tongue tissue by light and electron microscopy with immunofluorescence and immunoperoxidase techniques. We conclude that fibronectin is absent from stable, differentiated parts of tissues, such as the sebaceous glands or the matrix, medulla, cortex, and cuticles of the hair and the inner and outer root sheaths, or even in tissues in which there is some cell movement, such as the epidermis. It is, however, characteristic of sites at which cell division is occurring in contact with an extracellular scaffolding, such as basement membrane or loose connective tissue. Conspicuous examples were in the glassy membrane and connective tissue sheath associated with the follicular epithelium, the basement membrane underlying vascular endothelial cells, the connective tissues surrounding and investing nerve and muscle fibre bundles, and the dermal connective tissue where fibronectin was often associated closely with collagen fibres. At the basement membrane of the dermal/epidermal junction, fibronectin occurred at the plasma membrane of the basal cells and in the lamina lucida area. There was no correlation with specific areas of cell-substrate adhesion, such as the hemidesmosomes. The endoplasmic reticulum of fibroblasts stained strongly suggesting that these cells represent a major site of synthesis.
    Materialart: Digitale Medien
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 48 (1979), S. 95-103 
    ISSN: 1432-0533
    Schlagwort(e): Schmidt-Lanterman incisures ; Electron microscopy ; Nerve crush ; Wallerian degeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The electron microscopy of changes at Schmidt-Lanterman incisures in Wallerian degeneration has been described only briefly previously. We have demonstrated that the changes up to 36 h after nerve crush are chiefly peri-incisural. At 12h and 24h ‘incisural dilatation’ consisted of an intraperiod line separation of peri-incisural myelin lamellae, which began among inner (adaxonal) lamellae extending later to outer (abaxonal) lamellae. The incisure itself showed little or no change. At 36 h, ovoid formation was apparent in most fibres. The sites of fibre cleavage to form ovoids occurred adjacent to incisures at the focal regions of myelin lamellae separation. Even within ovoids the incisures themselves remained intact at 36 h. The fine structural changes at incisures following nerve crush provide an understanding of the increased perceptibility of incisures by light microscopy during early Wallerian degeneration.
    Materialart: Digitale Medien
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  • 89
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 48 (1979), S. 139-143 
    ISSN: 1432-0533
    Schlagwort(e): Mucopolysaccharidosis II ; Prenatal diagnosis ; Electron microscopy ; Lysosomal storage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light and electron microscopic findings in the nervous system of a 23-week-old fetus are reported, in which MPS II was diagnosed prenatally. The degrees of myelination and neuronal differentiation were similar as in a normal fetus of the same age. A storage of mucopolysaccharides in typical vacuolar inclusion bodies was present throughout the peripheral and central nervous system, mainly in cells of mesenchymal origin. “Zebra” bodies and granulo-membranous bodies, which are thought to represent secondary ganglioside accumulation were only found in the well developed neurons of the spinal cord and spinal ganglia, but not in the poorly developed neurons of the cerebellar and cerebral cortex. Mucopolysaccharide storage in endothelial cells of cerebral blood vessels precedes the appearance of lipid storage in cerebral neurons.
    Materialart: Digitale Medien
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  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 48 (1979), S. 219-221 
    ISSN: 1432-0533
    Schlagwort(e): Herpes simplex virus ; Organotypic nerve cell cultures ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In HSV-2 infected cultures, intranuclear tubule-like structures were found more commonly in fibroblasts and central nervous system (CNS) neurons than in oligodendrocytes, astrocytes, satellite and Schwann cells, but were found least often in peripheral neurons.
    Materialart: Digitale Medien
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 265 (1979), S. 195-206 
    ISSN: 1432-069X
    Schlagwort(e): Hyalinosis ; Electron microscopy ; Glycosaminoglycan ; Glycoprotein ; Cross-banded structure ; Schlüsselwörter ; Hyalinose ; Elektronenmikroskopie ; Glykosaminoglykan ; Glykoprotein ; Struktur mit Querstreifen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Systematisierte Hyalinose (Juvenile Hyaline Fibromatose) ist durch die hyalinisierten Hautefflorescenzen gekennzeichnet. Die elektronenmikroskopische Untersuchung eines hyalinisierten Hauttumors von einem 19jährigen Mann mit diesem Syndrom ergab, daß die Hyalinsubstanz sich aus den Rutheniumrot-positiven Ultrastrukturen des Glykosaminoglykans oder des Glykoproteins (d. h. Körnchen, Fäden und einer Struktur mit Querstreifen) und einigen dünnen Kollagenfibrillen zusammensetzte. Mit unserer neuen Rutheniumrotfärbung in der Kombination mit der Enzymverdauungsmethode wurde demonstriert, daß die Struktur mit Querstreifen und die Körnchen aus Chondroitinsulfat-Proteoglykan und/oder Glykoprotein besteht, und daß es sich bei der Struktur mit Querstreifen höchstwahrscheinlich um ein nichtkollagenes Aggregationsprodukt der Körnchen handelt, die eng an die parallel angeordneten, Hyaluronsäure-ähnlichen Fäden angelegt sind.
    Notizen: Summary Systematic hyalinosis (juvenile hyaline fibromatosis) is characterized by hyalinized skin lesions. Electron microscopic examination of a hyalinized skin tumor from a 19-year-old man with this syndrome revealed that the hyaline was composed of ruthenium red-positive ultrastructures (granules, filaments, and a kind of cross-banded structure), indicating the presence of glycosaminoglycan or glycoprotein, and a small number of thin collagen fibrits. Using a new ruthenium red staining method combined with an enzymatic digestion procedure, it was demonstrated that the cross-banded structure and granules consisted of chondroitin sulfate-proteoglycan and/or glycoprotein, and that the cross-banded structure is probably a noncollageneous aggregate of the granules attached to the parallel-arranged filaments of hyaluronic acid-like nature.
    Materialart: Digitale Medien
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 265 (1979), S. 91-99 
    ISSN: 1432-069X
    Schlagwort(e): Electron microscopy ; Civatte body ; Atrophy ; Light sensitivity ; Heredity ; Elektronenmikroskopie ; Civatte-Körperchen ; Atrophie ; Lichtempfindlichkeit ; Vererbung
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Zwei Patienten (insgesamt 4), zwei Brüder, mit »The diffuse and macular atrophic dermatosis» wurden beobachtet. Das familiäre Vorkommen, die «peau citréine»-Plaquen an der dorsalen Seite des Rumpfes, sowie eine kongenitale Phimose mit einer oberflächlichen Atrophie des Glans Penis, sind die neuen Befunde. Licht- und elektronenmikroskopische Befunde einer «peau citréine»-Plaque und einer erythematösen, skleroatrophischen Plaque werden geschildert. Es wurde auch gezeigt, daß die elastischen, färbungspositiven kugelähnlichen Strukturen, die in ungewöhnlich großer Zahl in der oberen Dermis gefunden wurden, fortgeschrittenere transformierte Civatte-Körperchen darstellen, die epidermale Zellen enthalten.
    Notizen: Summary Two brothers with the “diffuse and macular atrophic dermatosis” making a total of 4 patients are reported. The familial occurrence, numerous large “peau citréine” plaques situated on the dorsum of the upper trunk and congenital phimosis with superficial atrophy of glans penis, represent the additional features reported. The light and electron microscopic findings of the least affected site on the arm, of a “peau citréine” and of an erythemoscleroatrophic plaque, none previously studied, have been reported. Among other items, it was also found that the elastic stain-positive globe-like structures found in an unusually large number throughout the edematous upper dermis represent more advancely transformed “Civatte bodies” containing epidermal filamentous cell material.
    Materialart: Digitale Medien
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Annals of hematology 39 (1979), S. 177-190 
    ISSN: 1432-0584
    Schlagwort(e): Chronische myelo-monozytäre Leukämie ; Seeblaue Histiozyten ; Knochenmarksbiopsie ; Elektronenmikroskopie ; Chronic myelomonocytic leukemia ; Sea-blue histiocytes ; Bone marrow biopsy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Clinical data and light and electron microscopic findings are presented in a patient with chronic myelomonocytic leukemia of about 5 years' duration and no need for specific therapy. Cytogenetic studies failed to demonstrate a Philadelphia-chromosome. The leading clinical symptoms were anemia, moderate hepatomegaly, and leukocytosis with monocytes in the peripheral blood count. Light microscopy of bone marrow cores showed hypercellularity of neutrophil granulocytic and monocytic cell lines including some precursor forms. Electron microscopy confirmed the existence of a biphasic myelomonocytic cell proliferation with predominance of mature forms in both lineages; there were no gross cellular abnormalities and no “hiatus leukaemicus”. Conspicuous were cells of an undeterminated origin apparently neither belonging to the neutrophil granulocytic nor monocytic series and large histiocytic cells, possibly corresponding to the so-called sea-blue histiocytes of light microscopy. The high degree of maturation of both cell lines in the bone marrow is in accordance with the relatively benign and prolongated course of this rare type of leukemia.
    Notizen: Zusammenfassung Von einem Patienten mit einer chronischen myelo-monozytären Leukämie von etwa 5 Jahren Dauer und ohne spezifische Therapie werden klinische sowie licht- und elektronenmikroskopische Befunde vorgestellt. Zytogenetische Untersuchungen ließen ein Philadelphia-Chromosom nicht erkennen. Die führenden Symptome waren eine geringe Anämie, eine mäßige Lebervergrößerung und Leukozytose mit Monozyten im peripheren Blutausstrich. Lichtmikroskopische Untersuchungen des Knochenmarkes zeigten eine Zellvermehrung der neutrophilen granulozytären und der monozytären Zellreihen einschließlich einiger Frühformen. Die Elektronenmikroskopie bestätigte das Vorhandensein einer biphasischen myelo-monozytären Zellproliferation mit Vorwiegen der reifen Formen in beiden Zellinien. Es bestanden keine bemerkenswerten zellulären Anomalien und kein „hiatus leucaemicus“. Auffallend waren Zellen unbestimmbarer Herkunft, die weder der neutrophilgranulozytären oder monozytären Reihe sicher zuzuordnen waren, und große histiozytäre Zellen, die wahrscheinlich den sogenannten „seeblauen Histiozyten“ der Lichtmikroskopie entsprechen. Der hohe Grad der Ausreifung in beiden Zellinien im Knochenmark steht in Übereinstimmung mit dem relativ gutartigen und langen Verlauf dieses seltenen Types einer Leukämie.
    Materialart: Digitale Medien
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 45 (1979), S. 187-194 
    ISSN: 1432-0533
    Schlagwort(e): Human adenovirus 12 ; Hamsters ; Subcutaneous neuroblastomatous tumor ; T-antigens ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Single subcutaneous inoculation of human adenovirus type 12 (Ad. 12), 0.05–0.1 ml of 108.0 TCID50 HEK cells/0.1 ml, was made on the back of 0-day-old hamsters. In 21 of 25 hamsters (84.0%), multiple solid tumors developed close to the inoculation site within 3 months. No control hamsters developed tumors. Tumor histopathology revealed the characteristic Homer Wright rosettes of neuroblastoma. Ad. 12-specific tumor antigens were demonstable in both the primary and the cultured tumor cells by the hnmunofluorescein technique. Histochemical demonstration of cholinesterase and NADH oxidoreductase gave rise to a predominantly positive intracytoplasmic granule within the tumor cells. Electron microscopy showed remarkably iniform cell morphology: small, undifferentiated neuroblastic cells with poorly developed intracytoplasmic organelles; many possessed characteristic solitary cilia in a 9+0 tubules pattern. Intercellular junctions were poorly developed. Search for an incipient tumor cell aggregate by means of immunofluorescein T-antigen detection was carried out through a 240-h period following Ad. 12 inoculation. A sequential study in parallel with electron microscopic examination of the normal subcutaneous tissue proved that neuroblastic cells closely associated with the muscle spindle anlage could preferentially become the most sensitive target for Ad. 12 tumorigenesis.
    Materialart: Digitale Medien
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 46 (1979), S. 133-137 
    ISSN: 1432-0533
    Schlagwort(e): Sensory neuropathy ; Nerve biopsy ; Electron microscopy ; Quantitative study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An electron microscope study and quantitation of myelinated and unmyelinated fibers of seven nerve biopsies performed in sporadic cases of idiopathic sensory neuropathy is reported. The number of myelinated fibers is markedly decreased or absent in every case. On the contrary, the unmyelinated fiber numbers are normal or increased. In most cases, the small diameter myelinated and unmyelinated fibers proportions are higher than those of control biopsies. The electron microscope study discloses evidence of degeneration of Wallerian type and regeneration is also indicated by quantitative studies. Regenerative phenomena seem more obvious in sporadic cases than in previously reported studies of familial cases.
    Materialart: Digitale Medien
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 47 (1979), S. 205-211 
    ISSN: 1432-0533
    Schlagwort(e): Brain tumor cells ; Chemical carcinogen ; Benzo(a)pyrene ; Oncogenesis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An ultrastructural study was performed on normal and Benzo(a)-pyrene (B(a)P)-transformed fetal mouse brain cells. Early subcultures of a strain initiated from whole brain presented three cell types in vitro: astroglial, poorly differentiated glial, and spongioblastic types. After B(a)P-treatment, there was an exclusive transformation and the growth of neuroglia sometimes without gliofibrillary maturation, but with the presence of glial fibrillary acidic protein (GFAP) in the cytoplasm. Early subcultures of another strain initiated from cortex only presented poorly differentiated neuroglial cells. After transformation, cell maturation as evidenced by gliofibrillogenesis and GFAP production by these cells was observed. In both cases, the potentiality of glial differentiation after in vitro malignant transformation by a chemical carcinogen seemed preserved.
    Materialart: Digitale Medien
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 46 (1979), S. 239-241 
    ISSN: 1432-0533
    Schlagwort(e): Acromegaly ; Electron microscopy ; Growth hormone ; Pituitary adenoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Unusually large, oval and pleomorphic secretory granules were noted by electron microscopy in an acidophilic adenoma of the pituitary. The tumor, which was removed by surgery from a 42-year-old woman with elevated blood growth hormone levels and the clinical features of acromegaly, was found to contain growth hormone by the immunoperoxidase technique. This ultrastructural abnormality of secretory granules was not reported so far and was not seen among the 58 cases of growth hormone-producing adenomas investigated in our laboratory. The present case clearly shows that the cytogenesis and cellular composition of pituitary adenomas cannot be determined by solely examining the size and shape of secretory granules.
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 47 (1979), S. 189-196 
    ISSN: 1432-0533
    Schlagwort(e): Childhood dermatomyositis ; Muscle biopsy ; Electron microscopy ; Tubular arrays
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Muscle biopsies from 12 patients with a typical clinical picture of dermatomyositis have been examined by electron microscopy. Endothelial cells of intramuscular blood vessels, their basal lamina, pericytes, muscle fibers, and satellite cells show degenerative or regenerative alterations. In nine patients, tubular arrays were noted in the cisterns of endoplasmic reticulum of endothelial cells, pericytes, lymphocytes, macrophages and satellite cells. Other types of inclusions were also observed. The pathogenesis of the disease is discussed.
    Materialart: Digitale Medien
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 47 (1979), S. 61-66 
    ISSN: 1432-0533
    Schlagwort(e): Experimental tumors ; Tissue culture ; Scanning ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Serially transplanted neurogenic tumors of experimental origin were explanted in vitro and analyzed by scanning electron microscopy. In explants of intracerebrally transplanted gliomas, small stellate cells with branching processes were observed; in transplanted tumors of the peripheral nervous system, slender bipolar cells as well as fibroblasts emerged. The stereoscopic features were compared with the picture of conventional light microscopy. The findings are consistent with the assumption of the glial derivation of CNS-tumors induced with neurotropic alkylating carcinogens. The peripheral tumors are composed of Schwann-cell like elements and fibroblasts. The significance of the results for the cytogenetic derivation of brain tumors are discussed.
    Materialart: Digitale Medien
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 46 (1979), S. 139-144 
    ISSN: 1432-0533
    Schlagwort(e): Perineurium ; Peripheral ganglion ; Diffusion barrier ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The perineurial diffusion barrier to horseradish peroxidase (HRP) and ferritin was investigated in superior cervical ganglia of rats and mice. The ganglion was surrounded by a delicate epineurium and 2–5 perineurial lamellae joined by zonulae occludentes and desmosomes. Following local application of tracers the animals were killed after 5, 30, and 60 min and the distribution of HRP and ferritin was studied by light and electron microscopy. The inner layers of the ganglionic perineurium prevented diffusion of both HRP and ferritin into the endoneurium. Owing to the fewness of the perineurial lamellae investing the ganglion. HRP had often extended to the innermost lamella 60 min after application. HRP and ferritin were present in vesicles of ganglionic perineurial cells. There was no passage of tracers via intercellular junctions.
    Materialart: Digitale Medien
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