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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
    European archives of oto-rhino-laryngology and head & neck 221 (1978), S. 157-162 
    ISSN: 1434-4726
    Schlagwort(e): Gefrierbruchmethode ; Elektronenmikroskopie ; Zonulae occludentes ; Gap junctions ; Limbus spiralis ; Freeze fracture ; Electron microscopy ; Zonulae occludentes ; Gap junctions ; Spiral limbus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Replicas of the freeze fractured spiral limbus are studied in chinchillas. Zonulae occludentes are demonstrated between the interdental cells and the inner sulcus cells; gap junctions are described connecting interdental cells and inner sulcus cells to one another and they are found between the perilymphatic cells in the spiral limbus.
    Notizen: Zusammenfassung Untersuchung des Limbus spiralis an Chinchillas mit Hilfe der Gefrierbruchmethode. Zonulae occludentes werden zwischen den Interdentalzellen und den Zellen des inneren Sulcus demonstriert; gap junctions verbinden die Interdentalzellen und die Zellen des inneren Sulcus miteinander, weiter finden sie sich zwischen den perilymphatischen Zellen des Limbus.
    Materialart: Digitale Medien
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 25 (1978), S. 217-222 
    ISSN: 1432-0827
    Schlagwort(e): Bone mineral ; Electron microscopy ; X-ray diffraction ; Dark field
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Electron microscopical observations of the size and shape of bone mineral crystallites have not been in complete agreement with X-ray diffraction findings. The two prevalent viewpoints consider bone mineral crystals to be either rod, or plate like in habit. There appears to be agreement that the smallest dimension of the crystals is about 5 nm, but there is discrepancy in the reported c-axial lengths. The method of dark field imaging is used to obtain a quantitative measurement of the c-axial length distribution in rabbit, ox and human bone: mean c-axial lengths 32.6 nm, 36.2 nm and 32.4 nm, respectively, show no significant difference at the 5% level to the mean c-axial length measured by X-ray line broadening. Both bright and dark field images strongly suggest that bone mineral has a plate like form. Reasons for past discrepancies are discussed.
    Materialart: Digitale Medien
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 33 (1978), S. 353-369 
    ISSN: 1432-1106
    Schlagwort(e): Synaptic development ; Visual system ; Visual cortex ; Superior colliculus ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The development of synapses in the visual cortex (VC) and superior colliculus (SC) of the rabbit has been examined with the electron microscope. In both areas, the number of synapses reaches adult levels by 20–25 days of postnatal age, but the development in the visual cortex is delayed in comparison to that in the superior colliculus. When S synapses (spheroidal vesicles, asymmetric thickening) are compared with F synapses (flattened vesicles, symmetric thickening), even greater differences are seen. In both the VC and SC, S synapses develop earlier than F synapses, though there is considerable overlap. Of interest is the fact that synapses in the visual cortex seem to overshoot their adult levels late in development, suggesting that an excess of synapses may be formed in this system. Multiple synapses, probably of retinal origin, increase in the first 3 weeks of synaptic development in the SC, but never are present in significant proportions in the VC. Synapse formation most often is characterized by formation of a junction and a postsynaptic thickening, followed by acquisition of synaptic vesicles. After 15 days, there is only a small number of such “non-vesicle synapses” in either the SC or VC.
    Materialart: Digitale Medien
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 377 (1978), S. 129-144 
    ISSN: 1432-2307
    Schlagwort(e): Nephropathia epidemica ; Hemorrhagic fever ; Glomerular changes ; Immune complex disease ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron microscopical changes in the glomeruli in 20 kidney biopsies from 18 patients, who were suffering from or had lately suffered from Nephropathia epidemica were studied. Various kinds of deposits were seen. Under the endothelial cells there were collections of light flocculent material. Small dark deposits were seen in the mesangium at the mesangial cell processes, inside the thickened basement membrane, and occasionally on the epithelial side of the membrane. Large deposits were seen around mesangial cells in the mesangium. Deposits were less numerous than in chronic immune complex diseases. The intramembranous or subepithelial deposits were associated with “moon craters”, membranous convoluted structures or membrane debris. Granular extracellular mesangial material, round extracellular particles and intraendothelial microtubular inclusions were occasionally seen. In two of our cases occasional capsular epithelial cells showed numerous myelin bodies. Typical viruses were not seen in the glomeruli. The findings are in accord with the short period of scanty immune complex deposition in the glomeruli in the clinically active phase of Nephropathia epidemica.
    Materialart: Digitale Medien
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 378 (1978), S. 347-359 
    ISSN: 1432-2307
    Schlagwort(e): Hyaline cartilage ; Proteoglycans ; Glycogen ; Matrix degeneration ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Hyaline cartilage of the talus of a diastrophic dwarf was studied by light and transmission electron microscopy before and after proteoglycan extraction or digestion, glycogen digestion, and enzyme marking. The nuclei of the chondrocytes were as a rule large and round and the cytoplasm contained large vacuoles. Best's carmine stained the cytoplasm of most cells red; after diastase digestion the cytoplasm remained unstained. This suggested that the cells contained glycogen. This observation was complimented by the ultrastructural demonstration of large amounts of glycogen. Cell scars were frequent. The shape and state of activity of the cells as well as the development of intracytoplasmic organelles showed great variability. The matrix showed many areas of degeneration and a general dearth of sulphated acid mucopolysaccharides. A lacey pattern of unmasked collagen fibers was frequently seen. Collagen fibers showed a great variability in diameter and often appeared frayed when examined by electron microscopy. These observations suggest an enzymatic deficiency in chondrocyte mucopolysaccharide and glucose metabolism. The techniques we used when added to biochemical studies should prove useful in the investigation of human dwarfism.
    Materialart: Digitale Medien
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 379 (1978), S. 25-33 
    ISSN: 1432-2307
    Schlagwort(e): Electron microscopy ; Microfilaments ; Microtubules ; Nuclear pockets ; Smooth muscle tumours
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Samples of gastric leiomyosarcomas from two male patients (69 years and 57 years of age) were studied by electron microscopy. The tumour cells contained abundant 50–90 å thick microfilaments and microtubules. Another cell type, regarded as immature leiomyosarcoma cell, contained numerous profiles of granular endoplasmic reticulum, free ribosomes and a well developed Golgi apparatus. There were intercellular junctions of zonula adherens-type between adjacent tumour cells. It was concluded that electron microscopy offers a valuable aid in the diagnosis of gastric neoplasms of smooth muscle origin.
    Materialart: Digitale Medien
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 379 (1978), S. 85-97 
    ISSN: 1432-2307
    Schlagwort(e): Bronchial carcinoid ; Oncocytoma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We describe a bronchial tumor with a biphasic pattern. The main cellular population is composed of large cells with eosinophilic cytoplasm packed with mitochondria. These oncocytes countain few dense-core membrane limited granules. The secondary cell population has the morphological and histochemical features that characterize the typical bronchial carcinoid. A third cell type, recognizable at ultrastructural level, contains numerous neurosecretory granules and abundant large mitochondria, seeming therefore to represent a transitional cell form. We assume that oncocytes and carcinoid cells, found in the same tumor with intermediate forms, represent the extremes of a morphological spectrum. Furthermore, the oncocytic cytoplasmic components (neurosecretory granules and the mitochondria) are present in reciprocal arrangement in the carcinoid cells. These observations, together with similar reported cases suggest that the oncocytic state corresponds to a functional stage. We consider that oncocytes from this endobronchial tumor and from similar pathologic conditions reported in the literature correspond to carcinoid cells with mitochondrial hyperplasia and with diminished endocrine activity. This oncocytic carcinoid tumor is associated, in the same pulmonary lobe, with a second neoplasm that has the histological and ultrastructural features of a poorly differentiated carcinoid (oat-cell carcinoma).
    Materialart: Digitale Medien
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 380 (1978), S. 317-325 
    ISSN: 1432-2307
    Schlagwort(e): Meningioma ; Psammoma bodies ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Psammoma bodies from eight meningiomas have been examined by both light and scanning electron microscopy (SEM). The bodies are primarily composed of calcium apatite which is deposited within a nidus of tightly laminated collagen fibers.
    Materialart: Digitale Medien
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 381 (1978), S. 1-11 
    ISSN: 1432-2307
    Schlagwort(e): Central neuroblastoma ; Electron microscopy ; Growth cone ; Primitive neural crest ; Neuronal cytogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A cerebral neuroblastoma removed surgically from a female child is presented. Electron microscopy showed numerous neuronal processes with growth cones which are a feature of the developing neurone. In addition there were some rosettes with distinct lumina. The luminal surfaces were covered with a smooth plasma membrane lacking any surface differentiation and the lateral surface of these cells had many cell junctions (terminal bars), reminiscent of a primitive neural tube. These features in a nerve cell tumor help to substantiate it as a neuroblastoma arising from immature rather than differentiated cells. The nature of this rare tumor is discussed.
    Materialart: Digitale Medien
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 377 (1978), S. 287-300 
    ISSN: 1432-2307
    Schlagwort(e): Megacolon ; Large intestine ; Endocrine cells ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The large intestine resected from 6 Hirschsprung's patients and surgical colonic biopsies from 6 control children were examined with light and electron microscopy. The presence and the relative distribution of various endocrine cell types in both groups of mucosa were determined. In light microscope studies endocrine cell data were expressed as number of cells per unit area of mucosa using a quantitative method after argentaffin and Grimelius's argyrophilic techniques and an immunoperoxidase reaction with glucagon and somatostatin (SRIF) antisera. The results indicate that endocrine cells are apparently not involved in Hirschsprung's disease, since their number and frequency did not differ significantly between the ganglionic and aganglionic segments of Hirschsprung's patients nor between the latter and control children. Glucagon immunoreactive cells were, on the average, 5–6 times and 7–9 times more numerous that SRIF cells in the rectum and the sigmoid, respectively. Ultrastructurally, five endocrine cell types could be distinguished. The fifth type, probably a transition type, apparently disappears in adults.
    Materialart: Digitale Medien
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 378 (1978), S. 55-65 
    ISSN: 1432-2307
    Schlagwort(e): Pituitary adenoma ; Acromegaly ; Hormone secretion ; Electron microscopy ; Immunologic techniques
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural examination of 184 pituitary adenomas demonstrated the presence of extracellular accumulations of electron dense material in 3 out of 64 cases with acromegaly. Fibrillary structures were seen in larger deposits of such material. This material was only observed in biopsies fixed directly with osmium tetroxide; initial fixation with glutaraldehyde did not retain the material and left empty spaces. Positive immuno-histochemical reaction with specific antibodies demonstrated that the extracellular material contained growth hormone (GH). The presence of this extracellular material could not be related to the age or sex of the patient nor to the duration of symptoms, size of the tumor, presence of diabetes mellitus, or concomitant secretion of prolactin. The pericapillary fibrous sheath was heavily thickened in the patient with the longest duration of symptoms, intermediate in thickness in the second and normal in the third.
    Materialart: Digitale Medien
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 379 (1978), S. 73-83 
    ISSN: 1432-2307
    Schlagwort(e): Neurofibrome ; Tactile-like corpuscles ; Perineurial cell ; Neuroectodermal origin ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In neurofibromas type I (plexiform) and type II (diffuse) the Schwann cell is the predominant cell in the neoplastic proliferation. Electron microscopic investigation of a neurofibroma with structures resembling tactile corpuscles (type III) revealed neoplastic proliferation of perineurial instead of Schwann cells. The tactile-like (pseudo-Meissnerian) corpuscles (corpuscules neurofibromateux) are formed by neoplastic perineurial cells. These cells have a tendency to wrap themselves around longitudinal structures, such as collagen fibres or axons, and to come into direct contact with the latter. This close relationship between the axon and the neoplastic perineurial cell, analogous to that between axon and Schwann cell, points to a neuroectodermal origin of the perineurial cell. The electron microscopic appearances suggest that either the Schwann cell or the perineurial cell is the essential neoplastic component of neurofibromas, the fibroblastic proliferation being a secondary phenomenon.
    Materialart: Digitale Medien
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  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 380 (1978), S. 31-48 
    ISSN: 1432-2307
    Schlagwort(e): Human liver ; Acute alcoholic hepatitis ; Histoenzymology ; Electron microscopy ; Alcoholic cirrhosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The interpretation of the morphological features of alcoholic hepatitis is discussed in terms of a comparison with the results of an ultrastructural and histoenzymological study of the liver biopsies of nine patients. In these patients liver biopsies were performed in the initial stage of the illness and fifteen days after five were re-biopsied, when the clinical and biological signs were improved. The correlations between morphological and biological data were good, especially for the levels of serological and histoenzymological alkaline phosphatase and gamma-glutamyltranspeptidase evaluations. However, when histological appearances had returned to normal, after two weeks of abstinence from alcohol several histological and ultrastructural features of the initial hepatitis persisted. The presence of evolving cirrhosis was a contributing factor to the severity of the changes seen. Morphologically, apart from the changes due to chronic alcoholic intoxication (steatosis, mitochondrial alteration), the hepatitic lesions comprise Mallory's bodies, cytoplasmic oedema and mitochondrial swelling. Cholestasis was invariably present. Histo-enzymologically there was a reduction in ATPase activity suggesting a metabolic failure in the energy producing pathways. In addition, in the periphery of lobules an active cirrhotic process was present, with tubular de-differentiation of hepatocytes and an increase in gamma-glutamyltranspeptidase on the cytoplasmic membrane. Because of the absence of any topographical relationship between hepatitis and cirrhosis, the presence of lymphocytes in the neighbourhood of the ductules suggested an indirect relationship between both processes, perhaps an autoimmune response initiated by Mallory's bodies.
    Materialart: Digitale Medien
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  • 75
    ISSN: 1432-2307
    Schlagwort(e): Human myocardium ; Left ventricle ; Electron microscopy ; Morphometry ; Aging
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Licht- und elektronenmikroskopisch wurde mit einem manuell-optischen Bildanalysesystem eine morphometrische Analyse am Herzmuskel durchgeführt. Das Untersuchungsgut stammte aus nicht belasteten menschlichen linken Ventrikeln, welches bei herzchirurgischen Eingriffen gewonnen wurde. Bei den Patienten lag entweder ein Foramen ovale persistens, ein Vorhofseptumdefekt (ASD) I.–II. Grades oder eine reine Mitralstenose III.–IV. Grades vor. Die linken Kammerdruckmittelwerte lagen im Normbereich. Das Patientengut konnte in eine junge Patientengruppe von 5–15 Jahren und in eine alte Patientengruppe von 42–78 Jahren unterteilt werden. Lichtmikroskopisch wurde ermittelt, da\ sich der Anteil des Interstitium am Herzmuskelgewebe mit dem Alter nicht verÄndert. Die Anzahldichte der Herzmuskelzellkerne nimmt im Alter ab (P〈0,001), was auf eine Verringerung der Anzahldichte der Herzmuskelzellen pro Testvolumen und eine Vergrö\erung der einzelnen Herzmuskelzelle schlie\en lÄ\t. Elektronenmikroskopisch konnte eine Vermehrung der Volumendichte der Myofibrillen (P〈0,02) mit zunehmendem Alter nachgewiesen werden, wÄhrend die Volumendichte der Mitochondrien konstant bleibt und die Volumendichte des restlichen Cytoplasmas sogar abnimmt (P〈0,05). Die Anzahl der Mitochondrien erhöht sich im Alter (P〈0,001), so da\ bei den einzelnen Mitochondrien mit zunehmendem Alter eine Verkleinerung eintritt.
    Notizen: Summary An ultrastructural and morphometric analysis was performed on human myocardial left ventricle, obtained during surgical heart operations on normally loaded ventricles. The diagnoses of the patients were a) Persistant foramen ovale b) Atrial septal defect stage (I.–II.) c) Mitral stenosis (stage III.–IV.). The median values of left ventricular pressure were not pathologically elevated. The patients were divided in 2 groups, the younger one ranging from 5–15 years, the older from 42–78 years. It was shown that the volume density of the interstitial tissue does not differ with the aging process. The number of the nuclei per test area of the heart muscle cells decreased within age (P〈0.001). This finding suggests a decreasing process in the number of the heart muscle cells and an increase in size of the individual myocardial cell. Increase in the volume density of myofibrils was demonstrated at electron microscopical level with aging (P〈0.02). The volume density of mitochondria is the same in both groups, whereas the volume density of the remaining cytoplasm (without myofibrils and mitochondria) decreases (P〈0.05). The numerical density of the mitochondria increased in the older patient group (P〈0.001).
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  • 76
    ISSN: 1432-2307
    Schlagwort(e): Human myocardium ; Left ventricle ; Hypertrophy ; Electron microscopy ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung An den KammerwÄnden menschlicher linker Ventrikel, die auf Grund einer Aortenstenose, einer Aorteninsuffizienz oder eines kombinierten Aortenvitium hypertrophiert waren, wurden licht- und elektronenmikroskopisch morphometrische Untersuchungen angestellt. Die Ergebnisse wurden mit denen, die an nicht belasteten menschlichen linken Ventrikeln gewonnen wurden, verglichen. Lichtmikroskopisch unterscheiden sich die Anteile der Volumendichten des Interstitium und der Herzmuskelzellen am gesamten Herzmuskelgewebe nicht statistisch signifikant. Es konnte morphometrisch eine Zellvergrö\erung festgestellt werden, die aus der signifikanten Verringerung der Volumendichte der Zellkerne (P〈0,001) und der Anzahl der Zellkerne pro TestflÄche (P〈0,0001) gegenüber den beiden Normalkollektiven resultiert. Elektronenmikroskopisch ist eine Zunahme der Volumendichten der Myofibrillen (P〈0,0001) auf Kosten des restlichen Cytoplasmas (P〈0,001) festzustellen, wÄhrend die Volumendichte der Mitochondrien im Vergleich mit den jungen und alten Patienten abnahm (P〈0,0001). Die OberflÄchendichte der Mitochondrien verringerte sich gegenüber den beiden Vergleichskollektiven (P〈0,001) ebenso wie die der Cristae mitochondriales (P〈0,0001). Diese Ergebnisse finden ihr morphologisches Korrelat in Mitochondriendestruktionen. Eine vermehrte Myolyse hat bei den hypertrophierten Herzen, die alle gewichtsmÄ\ig über dem kritischen Herzgewicht lagen, noch nicht eingesetzt. Bei allen Patienten wurde der herzchirurgische Eingriff mit Erfolg durchgeführt.
    Notizen: Summary Biopsies of hypertrophied human myocardial left ventricles were investigated morphometrically. The diagnoses of the patients were stenosis of the aortic valve, aortic insufficiency or a combination of both lesions. The results were compared with those from normally loaded human left ventricles. There are no differences on light microscopical level between the volume densities of interstitial tissue and of heart muscle cells in the three groups of patients. A significant diminution of the volume density of the nuclei (P〈0.001) and the number of nuclei per test area (P〈0.0001) when compared with normal groups suggests an increase in volume of the single heart muscle cell. The ultrastructural study shows marked increase in volume density of myofibrils (P〈0.0001), with accompanying decrease in the volume densities of mitochondria (P〈0.0001) and the remaining cytoplasm (P〈0.001). A gross decrease in the surface area of mitochondria (P〈0.001) and of cristae mitochondriales (P〈0.0001) is found. The morphological equivalents of this result are numerous stages of mitochondrial destruction including cristolysis. All myocardial weights were beyond the “critical heart weight”.
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  • 77
    ISSN: 1432-0568
    Schlagwort(e): Myofibrillogenesis ; Human heart ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The myofibrillogenesis in the human embryonic heart is described. The synthesis of thin filaments, which are the first to appear, takes place in close proximity to smooth surfaced SR tubules. Z-band material is closely related to the thin filaments and appears first as irregularly distributed patches in the filamenteous mass. Further cellular differentiation includes an organization of the thin filaments/Z-band material. The synthesis of thick filaments, which follows that of the thin filaments, takes place in ribosome rich areas of the cell. They are rapidly incorporated into the strings of organized thin filaments/Z-band material. The periodic binding sites on both kinds of filaments are believed to play an important role in the precise ordering of the filaments. The formation of myofilaments in the adult hypertrophied human heart is also described. The similarities between this process and that observed in the embryonic heart are striking, and we believe it to be the same process.
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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 152 (1978), S. 223-234 
    ISSN: 1432-0568
    Schlagwort(e): Chick embryo ; Lung maturation ; “in ovo” decapitation ; Lung lipids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of “in ovo” hypophysectomy on lung maturation of the chick embryo were investigated. Both biochemical and morphological aspects of differentiation were markedly delayed in experimental embryos: the phospholipid content of lungs was lower than in controls at all stages, whereas the water content remained very high. The type II pneumocytes, which normally appear within the epithelium on day 16 of incubation, started to differentiate only between days 18 and 20 of incubation in the decapitated embryos. The differentiation of type I pneumocytes leading to the formation of air capillaries was also slowed down: they did not appear until the end of incubation in decapitated embryos, whereas they normally start to appear on day 19. The presence of an intact hypophysis is thus essential for normal lung maturation in the chicken.
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  • 79
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 152 (1978), S. 235-241 
    ISSN: 1432-0568
    Schlagwort(e): Chick embryo ; Lung maturation ; Influence of pituitary ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to discover whether the embryonic chick hypophysis acts upon lung maturation directly or via its corticotrophic activity, immature lung primordia were grafted into young hosts, either alone or associated with functional adrenals or pituitaries. When lung primordia were grafted alone, type II pneumocytes did not differentiate. Their differentiation was restored when lung primordia were grafted in association with either adrenals or pituitaries. This last result, which was also obtained in vitro, shows that the hypophysis is able, by itself, to promote the maturation of respiratory epithelium.
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 153 (1978), S. 287-293 
    ISSN: 1432-0568
    Schlagwort(e): Mouse embryos ; Visceral yolk sac ; Trypan blue ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural features of the early visceral yolk sac epithelium of normal mouse embryos on day 9 were compared to those whose mothers had received a single subcutaneous injection of 100 mg/kg trypan blue on day 8. The following results were obtained: In normal embryos the visceral yolk sac cells are predominantly characterized by numerous membrane bounded inclusions localized in the supranuclear cytoplasm. In embryos of animals treated with trypan blue, at about 12h after injection large single and only partly membrane bounded vacuoles are observed occupying most of the apical cytoplasm. Up to 24h after injection large cytoplasmic areas are seen which are in a stage of autodigestion possibly due to leakage of the vacuolar content. These alterations are exclusively limited to the visceral yolk sac epithelium whereas in the cells of the embryonic part, e.g. head process, no changes could be found. The observations are discussed in relation to the mechanism of the teratogenic activity of trypan blue.
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 153 (1978), S. 23-36 
    ISSN: 1432-0568
    Schlagwort(e): Electron microscopy ; Quail embryo ; Rathke's pouch
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Adenohypophyseal region of quail embryo has been examined by electron microscopy from stage 12 to stage 21 of Zacchei (1961). The Seessel's pouch develops prior to the early stages of adenohypophysis formation, then regresses while Rathke's pouch proliferates and differentiates. From Rathke's pouch formation by stage 12 (48 h of incubation) until appearance of the first secretory granules by stage 21 (6 days of incubation), there are no major ultrastructural modifications in adenohypophyseal cells. Mitochondria, Golgi vesicles, polysomic ribosomes, pinocytotic vesicles, and mitotic figures become more numerous while nucleocytoplasmic ratio and the number of ribosomes and lipid droplets decreases. The major change is the appearance of secretory granules by day 6 of incubation. This phenomenon occurs at the same time as in chick embryo, despite an incubation period shorter for quail than for chick. Mitotic figures are mainly distributed near the pouch lumen, while secretory granules are first located in the peripheral cells of the cephalic part ofpars distalis primordium. The hypothetical role of mesenchyme and vascularization is discussed.
    Materialart: Digitale Medien
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 261 (1978), S. 7-16 
    ISSN: 1432-069X
    Schlagwort(e): Erythema elevatum diutinum ; Extracellular cholesterosis ; Electron microscopy ; Lipid deposition ; Vasculitis ; Erythema elevatum diutinum ; Extracelluläre Cholesterinose ; Elektronenmikroskopie ; Lipidablagerung ; Vaskulitis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 1. Ein typischer Fall von Erythema elevatum diutinum (E.e.d.) mit extracellulärer Cholesterinose bei einer 48jährigen Patientin mit bisher 15 Jahre dauerndem Verlauf wird klinisch und histologisch beschrieben. 2. Elektronenmikroskopisch wird die histologisch und immunfluorescenzmikroskopisch nachgewiesene leukocytoklastische Vaskulitis bestätigt. In älteren Herden herrschen Histiocyten/Makrophagen vor. Intra- und extracelluläre Lipidablagerungen erscheinen elektronenmikroskopisch unter verschiedenartigen Bildern, die sich in ihrer Gesamtheit von allen anderen bisher ultrastrukturell beschriebenen Krankheiten mit Lipidablagerungen unterscheiden. 3. Die Befunde sind mit der Hypothese vereinbar, daß primär bei E.e.d. eine besondere Form von chronischer leukocytoklastischer Vaskulitis vorliegt und die Lipidablagerungen sekundär auf dem Boden von Gefäßwandschädigungen und Nekrosen entstehen.
    Notizen: Summary 1. A typical case of Erythema elevatum diutinum (E.e.d.) with extracellular cholesterosis is described clinically and histologically in a 48-year-old woman. The disease had a course of 15 years. 2. Electron microscopy confirmed the histological and immunfluorescent findings of leucocytoclastic vasculitis. In older lesions, histiocytes/macrophages predominate. Intra- and extracellular lipid depositions showed a variety of ultrastuctural characteristics which differed from electron microscopical findings described in other disorders associated with lipid deposition. 3. The findings are in accordance with the hypothesis that the primary event in E.e.d. is a special type of chronic leukocytoclastic vasculitis. Subsequently, the damage of the vessel walls and focal necrosis may lead to secondary lipid deposition.
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 262 (1978), S. 83-96 
    ISSN: 1432-069X
    Schlagwort(e): Keratohyalin ; Keratinization ; Wart ; Papilloma ; Rat tongue ; Electron microscopy ; Osmium tetroxide ; Hydrogen peroxide ; Pepsin ; Keratohyalin ; Keratinisation ; Warzen ; Papillom ; Rattenzunge ; Elektronenmikroskopie ; Osmiumtetroxid ; Hydrogenperoxid ; Pepsin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Heterogenität von Keratohyalin wurde in der Rattenzunge und in menschlichen Warzen dargestellt. Beide zeigen morphologische Ähnlichkeiten, wie dichte homogene ovoide einzelne Granula und zusammengesetzte Granula, die offenbar aus einzelnen Granula sich ableiten und von einer Membran überzogen sind. Die Ultrastruktur dieser Keratohyalinkörper wurde durch Fixierung mit Osmiumsäure nach Oxydation mit H2O2 und nach Pepsinbehandlung verglichen. Die einzelnen Granula sind osmiophil, während die zusammengesetzte Granula diese Eigenschaft nicht zeigen. Bei menschlichen Warzen zeigte sich eine fehlende Oxydierung durch H2O2 der einzelnen Granula, während die zusammengesetzten Granula oxydationsempfindlich sind. In der Zunge von neugeborenen Ratten zeigten sich die umgekehrten Verhältnisse. Diese Unterschiede zeigen, daß es unmöglich ist, die Bildung von Keratohyalingranula auf dem gleichen Wege zu erklären, wie die der Keratohyalingranula bei den Ratten, obwohl ultrastrukturelle Ähnlichkeiten bestehen. Es erscheint wichtig darauf hinzuweisen, daß die Keratogenese und die Keratohyalingranulabildung, die bei den Verrucae vulgaris vorliegt, von der Keratohyalinentwicklung in der Rattenzunge sich unterscheidet.
    Notizen: Summary The heterogenecity of keratohyalin (KH) has been demonstrated in rats, then in human warts where similar morphological features have been found and among them, dense homogeneous ovoïd single granules (SG) and composite granules (CG) apparently made up of single granules “coated” with a matrix. This work compares the ultrastructure of the KH of the tongue of newborn rats with that of common warts with and without post-fixation by OsO4, after oxydation by H2O2 and after pepsin treatment. The osmiophily of the SG is confirmed as well as the absence of osmiophily of the matrix of the CG. In man, however, the SG are resistant to oxydation by H2O2 and the CG matrix is oxydation sensitive whereas the opposite is observed in the case of rats. These differences show that it is impossible to deduce the composition of the KH in human warts from that of the rat despite their close ultrastructural resemblance but that important modification of the keratogenesis and KH formation are induced in the cells parasited by the virus of common warts.
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  • 84
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 262 (1978), S. 301-309 
    ISSN: 1432-069X
    Schlagwort(e): Lymphatic vessel(s)-lv ; Localized lymphangioma circumscriptum-Lc ; Electron microscopy ; Lymphgefäße ; lokalisiertes Lymphangiom ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Lymphgefäße (lv) in einem lokalisiertem Lymphagiom (Lc) wurde elektronenmikroskopisch untersucht. Dieses Lymphangiom, das kein Hämangiom begleitete, wies klinisch ein typisches Bild auf, und zeigte histologisch keine entzündlichen Zeichen. Die Lymphgefäße in dieser Veränderung wurden morphologisch in zwei Typen eingeteilt. Die Lymphgefäße des ersteren Typs, die im oberen Corium lagen, zeigten wie bei der experimentell induzierten Lymph-Stauung, ähnliche Bilder während diejenigen im tieferen Corium, Ähnlichkeiten zu den des normalen Lymphgefäßes erkennen lassen. Aufgrund der in dieser Untersuchung erlangten Befunde und unter Berücksichtigung der Literaturen ließ sich ableiten, daß dieses lokalisierte Lymphagiom nicht als ein echter gutartiger Tumor betrachtet wurde, sondern durch eine dauernde Lymph-Stauung in einem tumorartigen Zustand gehalten wurde.
    Notizen: Summary An electron microscopic study was performed on the lymphatic vessel (lv) of localized lymphangioma circumscriptum (Lc), which was found clinically typical but histologically not associated with hemangioma and inflammation. The lv of Lc was morphologically divided into two types. The first type was situated at the upper dermis of the lesion and the other, at the deep dermis. The former had certain similarities to lv of experimentally induced lymph-stasis, whereas the latter was morphologically similar to lv of the normal skin. From the findings of the present study and those reported in literature, Lc could not be considered as a mere benign overgrowth of lv, but as one of pathological results induced by a long-standing lymph-stasis.
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 263 (1978), S. 1-12 
    ISSN: 1432-069X
    Schlagwort(e): Viral papilloma ; Flat warts ; Epidermodysplasia verruciformis ; Human papovavirus ; Electron microscopy ; Virusales Papillengeschwulst ; Warzen ; Epidermodysplasia verruciformis ; Papovavirus beim Menschen ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei der Beantwortung der Fragen, ob die Epidermodysplasia verruciformis (E. V.) und die disseminierten Warzen verschiedene Erkrankungen sind, wurde eine vergleichende ultrastrukturelle Studie der epidermalen Klarzellen von zwei Fällen von E.V. und 4 Warzen von 4 Patienten, bei denen 3 unter immunsuppressiver Therapie standen, vorgenommen. Bei der E.V. wurde eine Reduktion der Tonofilamente und des Keratohyalins und bei den flachen Warzen ein zentrifugales Ödem und eine Vakuolisierung festgestellt. Die Zahl der Ribosomen war beim E.V. erhöht und vermindert bei den flachen Warzen. Somit können diese beiden Erkrankungen untereinander differenziert werden und weisen auf eine unterschiedliche Gast-Virus-Beziehung hin.
    Notizen: Summary Are Epidermodysplasia verruciformis (E. V.) and disseminated flat warts different diseases? Are there any diagnostic criteria between them? In order to attempt answering these 2 questions, fundamental for prognosis and nosology, a comparative ultrastructural study was made of epidermal clear cells of 2 cases of E. V. and 4 flat warts from 4 patients of whom 3 were under immunosuppression drugs. The reason of cytoplasmic electron translucency was mainly a reduction in tonofilaments and keratohyalin amounts in E. V. and a centrifugal edema and vacuolization in flat warts. On the other hand, the number of ribosomes was raised in E. V. and reduced in flat warts. These findings allow differentiation between the 2 diseases and suggest a possible different host-virus relationship.
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Annals of hematology 36 (1978), S. 149-157 
    ISSN: 1432-0584
    Schlagwort(e): Plasmazellen ; Nichtsekretorisches Myelom ; Elektronenmikroskopie ; Plasma cells ; Non-secretory myeloma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary A case of “non-secretory” multiple myeloma is described. The diagnosis was based on the clinical picture, typical radiological findings, and infiltration of the bone marrow by myeloma cells which showed specific immuno-fluorescence staining mainly with antisera for IgM and kappa light chains. An attempt is made to explain the absence of pathological proteins in the serum, based on the ultrastructural findings of the myeloma cells, which showed “buddings” of the cell membranes containing endoplasmic reticulum and cytoplasmic material. It is suggested that the cells of the “non-secretory” type of multiple myeloma possess a normal excretory mechanism, but the pathological proteins are prevented to be secreted in the serum being surrounded by portions of the cell membrane.
    Notizen: Zusammenfassung Bei einem Patienten mit nichtsekretorischem Plasmozytom wurden die Plasmazellen immunologisch und elektronenmikroskopisch untersucht. Die Diagnose beruhte auf dem klinischen Bild, den typischen Röntgenbefunden und einer Infiltration des Knochenmarks durch Plasmozytomzellen, die eine spezifische Immunfiuoreszenz mit Antiseren für IgM und kappa-Leichtketten zeigten. Es wird versucht, das Fehlen des Paraproteins im Serum mit Hilfe der elektronenmikroskopischen VerÄnderungen zu erklÄren. In den Plasmazellen der nichtsekretorischen Myelome wird die Sekretion der Paraproteine wahrscheinlich dadurch verhindert, da\ sie durch Membranfragmente eingeschlossen werden.
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 263 (1978), S. 47-58 
    ISSN: 1432-069X
    Schlagwort(e): Candida albicans ; 8-Methoxypsoralen ; UVA ; Electron microscopy ; Candida albicans ; 8-Methoxypsoralen ; UVA ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Candida (C.) albicans Zellen wurden 8-Methoxypsoralen (8-MOP) Konzentrationen von 1,0 μg/ml und 10,0 μg/ml Medium ausgesetzt und anschließend mit UVA (365 nm) bestrahlt. Die Bestrahlungsdosis betrug 4,8 J/cm2. Zwei unterschiedliche Arten von Zellschäden wurden beobachtet, die einmal das Cytoplasma und dessen Organellen, zum andern die Zellwand der Hefezellen betrafen. 2h nach Abschluß der Bestrahlung sah man Unregelmäßigkeiten der Form der Mitochondrien, die mitochondrialen Membranen waren verschwommen, die Cristae schwer oder nicht erkennbar. Die Zahl der Vacuolen war erhöht. Das Cytoplasma war von unregelmäßig begrenzten Bezirken verminderter Elektronendichte durchsetzt, die cytoplasmatische Membran war stellenweise nicht darstellbar. Kern und Kernhüllen ließen zu diesem Zeitpunkt keine Auffälligkeiten erkennen. 24 h nach Behandlungsende traten zusätzlich eigentümliche Veränderungen der Zellwand auf. Neugebildete Zellwandmassen saßen der innersten Wandschicht kugel-oder sichelförmig auf. Die Untersuchungen legen nahe, daß die nach kombinierter Anwendung von 8-MOP und UVA an C. albicans Zellen erhobenen Befunde nicht im Sinne einer allgemein cytotoxischen Wirkung interpretierbar sind. Anscheinend handelt es sich um ein Kombinationsgeschehen aus regressiven und progressiven Veränderungen.
    Notizen: Summary Candida (C.) albicans cells were exposed to 8-Methoxypsoralen (8-MOP) concentrations of 1.0 μg/ml and 10.0 μg/ml medium and irradiated with 365 nm light. The amount of energy emitted was 4.8 J/cm2. Two divergent types of cell damage occured concerning yeast cell cytoplasm and cell wall. Two hours after exposure cytoplasmic changes involving mitochondria, which showed irregularities in shape, blurred appearance or loss of mitochondrial cristae and outer membrane were seen. The number of vacuoles was increased. The cytoplasm showed large electron transparent areas, the cytoplasmic membrane disappeared in some areas completely. Nucleus and nuclear envelope usually remained intact in early stages. 24h after exposure conspicuous cell wall alterations were observed in addition to cytoplasmic changes. Newly produced cell wall material formed ball-like protrusions or was adherent sickle-shaped to the cell wall. The investigations strongly suggest that the results found after 8-MOP-UVA treatment of C. albicans cells can not be interpreted in the sense of a general cytotoxic effect. Apparently it takes the form of a combination of events involving regressive and progressive alterations.
    Materialart: Digitale Medien
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 263 (1978), S. 227-233 
    ISSN: 1432-069X
    Schlagwort(e): Erythrocytes ; Painful bruising syndrome ; Freeze-etching ; Electron microscopy ; Rote Blutzellen ; ≫Painful bruising≪-Syndrom ; Gefrierätzung ; Elektronen-Mikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei 3 Patienten mit dem Gardner-Diamond Syndrom oder dem ≫painful bruising≪-Syndrom sind morphologische Abweichungen an roten Blutzellen festgestellt worden. Von diesen roten Zellen, die bei der Ficoll/Isopaque Gradient Zentrifugation nicht sedimentierten, werden teilweise keulenförmige Ausläufer, Mitochondrien, Kernreste und Vacuolen festgestellt. Bei pH 7.4 zeigten 90% der roten Blutzellen in Gefrierätzparaten Ausbuchtungen auf der Membran, während bei pH 6,4 noch 25% der roten Zellen diese Erhebungen zeigten. Im Kontrolpräparaten waren diesen Zahlen 55% und 0% unterschiedlich bei pH 7.4 und 6.4. Die Geldrollenbildung im Blut von Patienten mit dem ≫painful bruising≪-Syndrom war stark erhöht.
    Notizen: Summary Red cells of 3 patients with the painful bruising syndrome showed morphological anormalities. In the fraction not sedimenting in Ficoll/Isopaque gradient centrifugation, some of these cells had club-shaped processes, mitochondria, nuclear remnants, and vacuoles. In freeze-etch preparations, 90% of the red cells showed membrane elevations at pH 7.4 and 25% at pH 6.4, while in freeze-etch preparations of controls these values were 55 and 0 respectively. In addition, rouleaux formation was markedly enhanced in the preparations of blood of patients with the painful bruising syndrome.
    Materialart: Digitale Medien
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  • 89
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 41 (1978), S. 229-234 
    ISSN: 1432-0533
    Schlagwort(e): Atypical senile dementia ; Electron microscopy ; Two types of filaments (neurofibrillary tangles)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A man aged 70, showed early disorientation, memory defects, delusions and rages at 66, later mental deterioration with muteness and dysphagia. He died of cardiac failure. The postmortem examination revealed macroscopically and light microscopically the neuropathological findings of atypical senile dementia. Moreover, it is the interesting characteristic in the presented case that there are electron microscopically two types of filaments making the neurofibrillary tangles. One showed the so-called “paired helical filaments”, which were observed in the cerebral cortex. The other showed parallel “straight filaments”. These “straight filaments” were found in the bilateral hippocampi.
    Materialart: Digitale Medien
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  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 59-62 
    ISSN: 1432-0533
    Schlagwort(e): Meningioma ; Hyaline inclusions ; Colloid bodies ; Pseudopsammomas ; Lamellar structures ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary One case of meningiothelial meningioma with “hyaline inclusions” (colloid-bodies or pseudopsammomas) as noted by Cushing and Eisenhardt (1938) and by Kepes (1961–1975) is reported by light and electron microscopy. Two types of these structures, either homogeneous or polymorphic, surrounded by microvilli are described and regarded as signs of secretory differentiation of tumor cells. In addition to Kepes' description, the authors show, at high magnification, the polymorphic material including homogeneous component, lamellar structures, microvesicles and dense bodies. The endocellular overproduction of the various types of “hyaline inclusions” and the nature of their material are discussed.
    Materialart: Digitale Medien
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 211-215 
    ISSN: 1432-0533
    Schlagwort(e): Canine CNS ; Myelination ; Hypomyelinogenesis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Five Chow-Chow dogs from three different litters had generalized body tremors since birth. Histologically a severe myelin deficiency was found in the central nervous system. The peripheral nerves were normally myelinated. Electron microscopically abnormally thin myelin sheaths and completely naked nerve fibers were found. There were many astrocytes in the myelin deficient areas as well as cells with the characteristic features of oligodendrocytes but also containing fibrils. The present cases are compared to other dysmyelinating diseases and possible pathogenetic mechanisms are discussed.
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 41 (1978), S. 207-210 
    ISSN: 1432-0533
    Schlagwort(e): Brain ; Hypercapnia ; Electron microscopy ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Thirteen adult rabbits were exposed to a breathing air mixture containing an increasing amount of CO2 for eight weeks. When the CO2 content reached 9 Vol% the animals became apathic and lost body weight. The EEG showed a reduction of the amplitudes of 10 Hz frequences. Blood gases revealed an increase of bicarbonate but no change of pH. The blood brain barrier which was tested when the animals were killed was not disturbed. Enzyme histochemistry, light and electron microscopy revealed that moderate brain edema had occurred. From these results it is concluded that chronic hypercapnia has a hypnotic effect which in combination with chronic edema may depress vital activities considerably. However, there seem to be no irreversible morphological alterations of the brain.
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 229-233 
    ISSN: 1432-0533
    Schlagwort(e): Melanotic tumors ; Neural crest ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A pigmented tumor was removed from the maxillar alveolar process of a 5-month-old boy. It was examined by light and electron microscopy and a diagnosis of melanotic neuroectodermal tumor was made. In addition to connective tissue, three main cell types were identified: undifferentiated (stem) cells, melanocytes, and nerve cells with processes forming an abundant neuropil. Numerous axo-dendritic and occasional axo-somatic synapses were observed. The neural component demonstrated better differentiation in this example than in any reported so far.
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 81-86 
    ISSN: 1432-0533
    Schlagwort(e): Bunina bodies ; Anterior horn cells ; Amyotrophic lateral sclerosis ; Cytoplasmic laminar bodies ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light and electron microscopic studies were made on the anterior horn cells in a case of amyotrophic lateral sclerosis. Eosinophilic inclusions of Bunina type were observed almost selectively in the motor neurons of spinal cord, as well as of brain stem, at the light microscopic level. Fine structural study revealed the presence of two types of cytoplasmic inclusions. The first, mainly corresponding to the light microscopic inclusions, were homogeneous, electron-dense, round- or oval-shaped bodies with vesicular or tubular rims and ribosome particles, about 2–5 μ in diameter, which contained filaments or other cytoplasmic components in the clear areas within them. The second were lamellar structures (laminated cytoplasmic bodies, Morales) which appeared to be originating from endoplasmic reticulum. There was no distinct transition in these two types of inclusions and the relationship to each other is not clear. The significance of Bunina body is unknown, but some manifestation of a primary disorder, e.g., protein metabolism, rather than a secondary degenerative change in the motor neurons in amyotorophic lateral sclerosis.
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 121-126 
    ISSN: 1432-0533
    Schlagwort(e): Nerve fiber teasing ; Phase contrast microscopy ; Electron microscopy ; Axonal and myelinic disorder ; Wallerian degeneration ; Secondary segmental demyelination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The changes in a sural nerve biopsy of a patient with porphyric neuropathy were studied by light and electron microscopy. Linear arrays of myelin ovoids constituted the most common abnormality in whole mounts of teased-fiber preparations. Round or irregular formations of variable osmiophilia were the most frequent finding in thick-section preparations examined by phase contrast microscopy. Lamellar whorls represented the most prevalent lesion in thinsections studied under the electron microscope. In addition, along the teased fibers, segmental demyelination was definitely detected, although rarely; in thick sections, the true extent of the nerve fiber loss was fully appreciated; in thin sections, a variety of axon and myelin changes of a distinct character were discovered. The studies demonstrate that in peripheral nerves of porphyric neuropathy, axonand myelin changes generally run together and proceed pari passu in the same segment of nerve fiber. Furthermore, among the pathogenetic mechanisms invoked to account for the neuropathic changes none are favored to the exclusion of others by these studies. Therefore, a primary axonaland myelinic disorder on the basis of a deranged porphyrin metabolism is as good a possibility as any hitherto advanced explanation of the pathogenesis of the neuropathic changes. The secondary lesions of Wallerian degeneration and segmental demylination may simple be grafted upon the primary lesions evoked by the metabolic abnormality.
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 41 (1978), S. 91-95 
    ISSN: 1432-0533
    Schlagwort(e): GM1 gangliosidosis ; Friesian calves ; Clinical retinoscopy ; Ocular pathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Late-onset of disturbed vision is a clinical feature of bovine GM1 gangliosidosis. Studies on eight affected calves showed that ocular lesions were confined to the retinae and optic nerves. Myriad tiny white spots were visible by ophthalmic examination of the fundus. These spots were related to protuberances on the vitreal surface caused by distended retinal ganglion cells. The perikaryons of these cells were packed with dense aggregates of membranous cytoplasmic bodies (MCBs). Similar MCBs were present in the perikaryons of amacrine cells in the inner nuclear layer of the retina. Wallerian degeneration was present in the optic nerves. The lesions were compared with those described in gangliosidosis in man, cats, pigs and dogs. It is suggested that examination of the fundus is a useful clinical procedure in the diagnosis of bovine GM1 gangliosidosis.
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 53-56 
    ISSN: 1432-0533
    Schlagwort(e): Blood-brain barrier ; Air embolism ; Horseradish peroxidase ; Cerebral cortex ; Electron microscopy ; Carotid artery ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Male albino rats were anaesthetized with diazepam, injected with horseradish peroxidase and Evans blue-labeled albumin and given an embolus of 0.01 ml air in the right common carotid artery after ligation of the external carotid branch. The pial arteries of the right cerebral hemisphere were stained blue, particularly the middle cerebral artery and its main arterial branchlets. Ultrastructurally, some endothelial cells in the right middle cerebral artery, small arteries and arterioles showed a diffuse distribution of horseradish peroxidase in their cytoplasm, although these vessels only occasionally showed peroxidase in their basement membranes. Other endothelial cells in these arterial branchlets showed few if any signs of a diffuse distribution of peroxidase but displayed several pinocytotic vesicles and occasionally trans-endothelial channels filled with peroxidase, sometimes with a slight leakage of peroxidase into adjacent basement membranes and neuropil. Scattered pinocytotic vesicles were observed in capillaries and venules, but there was usually no extravasation of peroxidase around these vessels.
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 91-102 
    ISSN: 1432-0533
    Schlagwort(e): Myclin degradation ; Wallerian degeneration ; Optic nerve ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural events in myelin degradation in the rat optic nerve following transection have been studied. Myelin debris was found in cells similar to multipotential glia cells (Vaughn and Peters, 1968) as well as in astrocytes and in few oligodendrocytes. The different types of inclusions found during myelin degradation were described in their quantitative relations. Similarities to inclusions described in adrenoleukodystrophy and multiple sclerosis are discussed. By comparison of the ultrastructural findings with histochemical and biochemical data available a hypothetical model of myelin degradation is presented. The process starts with the degradation of digestible proteins resulting in uniformly layered lipid inclusions. Lipid degradation leads to the formation of unstructured lipid droplets and crystals. During the late stages of Wallerian degeneration numerous polymorph inclusion types can be found, probably representing poorly digestible lipids or lipoproteins.
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 43 (1978), S. 135-141 
    ISSN: 1432-0533
    Schlagwort(e): Nerve injury ; Perineurium ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The intrafascicular contents have been extracted from the tibial nerve of the rabbit through perineurial incisions. Within 6–8 days following this procedure, the perineurial cells separate from one another, become dissociated from their basement membranes and assume a fibroblast-like appearance. The intrafascicular space becomes populated with endoneurial fibroblasts. With the ingrowth of regenerating axons, bundles of axons and associated Schwann cells become surrounded by cells of fibroblastic appearance which undergo perineurial transformation resulting in the development of multiple small fascicles. The cells of the surrounding perineurium appear to reassume a lamellar organization and to reestablish contacts with each other with the formation of junctional complexes. It is therefore suggested that neural structures may be responsible for the development and maintenance of the structural organization of the perineurium.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 63-70 
    ISSN: 1432-0533
    Schlagwort(e): Corona virus ; Weanling rats ; Demyelination ; Immunofluorescence ; Electron microscopy ; Oligodendrocyte and Astrocyte
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Thirty percent of weanling rats infected with JHM murine corona virus developed a subacute demyelinating encephalomyelitis approximately 3 weeks after intracerebral inoculation. Small demyelinating foci were located in the deep cerebral white matter and large, sharply demarcated demyelinating lesions were detectable in optic chiasma, pons and spinal cord. Axons as well as neurons were well preserved in the demyelinating plaques in areas where the lesions extended to the gray matter. Perivascular cuffings, consisting of plasma cells and mononuclear cells, were frequently found. Viral antigen was found mostly in the white matter and in glial cells, leaving neurons unstained. Electron microscopic studies of the early lesions of white matter disclosed two different kinds of cell degeneration which developed prior to the myelin disruption and mononuclear cell infiltration. One was a small pyknotic cell, which is thought to be an oligodendrocyte and the other is a ballooned cell containing abundant microtubules. Virus particles could be demonstrated only in the latter cell type. Discussion about astrocytes as well as oligodendrocytes was made in relation to the initial stage of demyelination caused by virus infection. This animal model may be useful in the analysis of the mechanisms leading to demyelination in subacute or chronic infections.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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